1
|
Baleani M, Erani P, Acciaioli A, Schileo E. Tensile Yield Strain of Human Cortical Bone from the Femoral Diaphysis Is Constant among Healthy Adults and across the Anatomical Quadrants. Bioengineering (Basel) 2024; 11:395. [PMID: 38671816 PMCID: PMC11048186 DOI: 10.3390/bioengineering11040395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
The literature suggests that the yield strain of cortical bone is invariant to its stiffness (elastic modulus) and strength (yield stress). However, data about intra-individual variations, e.g., the influence of different collagen/mineral organisations observed in bone aspects withstanding different habitual loads, are lacking. The hypothesis that the yield strain of human cortical bone tissue, retrieved from femoral diaphyseal quadrants subjected to different habitual loads, is invariant was tested. Four flat dumbbell-shaped specimens were machined from each quadrant of the proximal femoral diaphysis of five adult donors for a total of 80 specimens. Two extensometers attached to the narrow specimen region were used to measure deformation during monotonic tensile testing. The elastic modulus (linear part of the stress-strain curve) and yield strain/stress at a 0.2% offset were obtained. Elastic modulus and yield stress values were, respectively, in the range of 12.2-20.5 GPa and 75.9-136.6 MPa and exhibited a positive linear correlation. All yield strain values were in the narrow range of 0.77-0.87%, regardless of the stiffness and strength of the tissue and the anatomical quadrant. In summary, the results corroborate the hypothesis that tensile yield strain in cortical bone is invariant, irrespective also of the anatomical quadrant. The mean yield strain value found in this study is similar to what was reported by inter-species and evolution studies but slightly higher than previous reports in humans, possibly because of the younger age of our subjects. Further investigations are needed to elucidate a possible dependence of yield strain on age.
Collapse
Affiliation(s)
- Massimiliano Baleani
- Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy; (P.E.); (A.A.)
| | - Paolo Erani
- Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy; (P.E.); (A.A.)
| | - Alice Acciaioli
- Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy; (P.E.); (A.A.)
| | - Enrico Schileo
- Laboratorio di Bioingegneria Computazionale, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy;
| |
Collapse
|
2
|
Lv Y, Gong C, Dong Y, Choi HJ. Synthesis of rGO/CoFe 2O 4 Composite and Its Magnetorheological Characteristics. Materials (Basel) 2024; 17:1859. [PMID: 38673216 PMCID: PMC11051295 DOI: 10.3390/ma17081859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/09/2024] [Accepted: 04/13/2024] [Indexed: 04/28/2024]
Abstract
In this study, composite particles of rGO/CoFe2O4 were synthesized using a solvothermal method to fabricate a low-density magnetorheological (MR) material with enhanced sedimentation stability. The morphology and crystallographic features of rGO/CoFe2O4 were characterized via SEM, TEM, and XRD, and its magnetic properties were tested using VSM. The MR fluid was formulated by blending rGO/CoFe2O4 particles into silicone oil. Under different magnet strengths (H), a rotational rheometer was used to test its MR properties. Typical MR properties were observed, including shear stress, viscosity, storage/loss modulus, and dynamic yield stress (τdy) following the Herschel-Bulkley model reaching 200 Pa when H is 342 kA/m. Furthermore, the yield stress of the MR fluid follows a power law relation as H increases and the index changes from 2.0 (in the low H region) to 1.5 (in the high H region). Finally, its MR efficiency was calculated to be about 104% at H of 342 kA/m.
Collapse
Affiliation(s)
- Yang Lv
- School of Materials Science and Engineering, Harbin Institute of Technology Weihai, 2 West Wenhua Road, Weihai 264209, China; (Y.L.); (C.G.)
| | - Chengjie Gong
- School of Materials Science and Engineering, Harbin Institute of Technology Weihai, 2 West Wenhua Road, Weihai 264209, China; (Y.L.); (C.G.)
| | - Yuzhen Dong
- School of Materials Science and Engineering, Harbin Institute of Technology Weihai, 2 West Wenhua Road, Weihai 264209, China; (Y.L.); (C.G.)
| | - Hyoung Jin Choi
- Department of Polymer Science and Engineering, Inha University, Incheon 22212, Republic of Korea
| |
Collapse
|
3
|
Ma KK, Ziegler GR, Hayes JE. Sugar reduction in chocolate compound by replacement with flours containing small insoluble starch granules. J Food Sci 2024; 89:1701-1710. [PMID: 38258973 DOI: 10.1111/1750-3841.16923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 11/21/2023] [Accepted: 12/20/2023] [Indexed: 01/24/2024]
Abstract
Consumer concern about intake of added sugars has increased commercial demand for sugar-reduced chocolates. However, substitution with high-potency sweeteners is not possible as sugar serves as an important bulking agent. Here, we investigated replacement of sucrose in chocolate compound with oat or rice flours, with starch granules smaller than 10 µm, focusing on texture, sweetness, and acceptability. In Study 1, six chocolates were made: a control with 54% sucrose, four sucrose-reduced versions (reductions of 25% or 50%, using either oat or sweet rice flour), and one 54% sucrose chocolate with reduced refining time. These chocolates were compared in a Difference from Control (DFC) test in a within-subject design, with and without nose clips. Particle size distribution, yield stress, and plastic viscosity were measured. Chocolates with 25% sucrose reduction by either sweet rice or oat flour (or reduced refining time) were not significantly different from the blind control (p > 0.05), regardless of nose clip use. In open-ended comments, participants reported differences in rice-flour-containing chocolates were due to a chalkier texture, while oat-flour-containing chocolates were described as smoother, softer, and creamier. DFC scores from the chocolates were positively correlated with plastic viscosity and negatively correlated with yield stress. In Study 2, 25% reduced sugar chocolates made with rice flour were liked significantly less than control, but the oat flour sample did not differ from control. Collectively, these results suggest up to 25% of sucrose in chocolate can be replaced with oat flour without negatively affecting texture or consumer acceptance.
Collapse
Affiliation(s)
- Kai Kai Ma
- Sensory Evaluation Center, College of Agricultural Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
- Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Gregory R Ziegler
- Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - John E Hayes
- Sensory Evaluation Center, College of Agricultural Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
- Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| |
Collapse
|
4
|
Kim JB, Lee HY, Chae C, Lee SY, Kim SH. Advanced Additive Manufacturing of Structurally-Colored Architectures. Adv Mater 2024; 36:e2307917. [PMID: 37909823 DOI: 10.1002/adma.202307917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/05/2023] [Indexed: 11/03/2023]
Abstract
Direct ink writing (DIW) stands out as a facile additive manufacturing method, minimizing material waste. Nonetheless, developing homogeneous Bingham inks with high yield stress and swift liquid-to-solid transitions for versatile 3D printing remains a challenge. In this study, high-performance Bingham inks are formulated by destabilizing silica particle suspensions in acrylate-based resin. A colloidal network forms in the shear-free state through interparticle attraction, achieved by disrupting the solvation layer of large resin molecules using polar molecules. The network is highly dense, with evenly distributed linkage strength as monodisperse particles undergo gelation at an ultra-high fraction. Crucially, the strength is calibrated to ensure a sufficiently large yield stress, while still allowing the network to reversibly melt under shear flow. The inks immediately undergo a liquid-to-solid transition upon discharge, while maintaining fluidity without nozzle clogging. The dense colloidal networks develop structural colors due to the short-range order. This enables the rapid and sophisticated drawing of structurally-colored 3D structures, relying solely on rheological properties. Moreover, the printed composite structures exhibit high mechanical stability due to the presence of the colloidal network, which expands the range of potential applications.
Collapse
Affiliation(s)
- Jong Bin Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hwan-Young Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Changju Chae
- Division of Advanced Materials, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Republic of Korea
| | - Su Yeon Lee
- Division of Advanced Materials, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Republic of Korea
| | - Shin-Hyun Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| |
Collapse
|
5
|
Mintel M, Lee J, Teoman B, Potanin A. Visual assessment and rheological characterization of shape retention of products on a surface. J Texture Stud 2023; 54:626-632. [PMID: 37318150 DOI: 10.1111/jtxs.12783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/24/2023] [Accepted: 05/28/2023] [Indexed: 06/16/2023]
Abstract
A device to measure the height loss of a sample extruded from a syringe on a surface is described thus emulating toothpaste extrusion from a tube with the goal to predict shape retention of the extruded ribbon. Correlations with rheological tests are considered with a special focus on experiments more likely to be implementable in an industrial environment. In agreement with previous studies, the instantaneous viscosity maximum measured in a stress ramp test is a good predictor of ribbon height loss. Up- and down-shear flow curves of the thixotropic loop were fitted with a generalized Casson equation and the correlations of the fitting parameters with the height loss were also considered. Yield stress extracted from the up-shear flow curve as well as the shape of the curve is found to define the ribbon height loss as well as the degree of thixotropy which may be quantified by the width of the loop or simply as the ratio of viscosities at low shear rate.
Collapse
Affiliation(s)
- Mark Mintel
- Colgate-Palmolive Company, Piscataway, New Jersey, USA
| | - Jonghun Lee
- Colgate-Palmolive Company, Piscataway, New Jersey, USA
| | - Baran Teoman
- Colgate-Palmolive Company, Piscataway, New Jersey, USA
| | | |
Collapse
|
6
|
Martínez-Padilla LP. Rheology of liquid foods under shear flow conditions: Recently used models. J Texture Stud 2023. [PMID: 37726094 DOI: 10.1111/jtxs.12802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 08/17/2023] [Accepted: 08/30/2023] [Indexed: 09/21/2023]
Abstract
Proper modeling of flow or viscosity curves as a function of shear rate is a useful tool in any engineering activity. The rheology of foods depends on the composition, processing to which they have been subjected and the state of dispersion in which they are found. Liquid foods are complex biosystems, that show non-Newtonian behavior under flow conditions. This review presents models used in recent decades to describe the experimental rheological behavior of various liquid foods, ranging from Newtonian fluids to the most complex. Some non-Newtonian parameters such as those of the Ostwald-de Waele, Bingham, Herschel-Bulkley, Casson, Cross, and Carreau models are summarized. Examples of thixotropic behavior described by the Weltman and Abu-Jdayil models are also presented. In each model, explanations based on the composition and dispersion state of the food are made. This is useful in innovative processing technologies and for scientists new to the field of food rheology. An attempt is made to exemplify and group the expected behavior for most fluid foods, including some for a dysphagia diet, depending on their composition or the dispersed system formed, which will be useful for professionals who wish to compare reported rheological parameters with those obtained experimentally.
Collapse
Affiliation(s)
- Laura Patricia Martínez-Padilla
- Laboratorio de Propiedades Reológicas y Funcionales en Alimentos, FES Cuautitlán, Universidad Nacional Autónoma de México, Mexico City, Mexico
| |
Collapse
|
7
|
Lupu A, Gradinaru LM, Rusu D, Bercea M. Self-Healing of Pluronic® F127 Hydrogels in the Presence of Various Polysaccharides. Gels 2023; 9:719. [PMID: 37754400 PMCID: PMC10528848 DOI: 10.3390/gels9090719] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/01/2023] [Accepted: 09/02/2023] [Indexed: 09/28/2023] Open
Abstract
Thermoresponsive Pluronic® F127 (PL) gels in water were investigated through rheological tests in different shear conditions. The gel strength was tuned with the addition of 1% polysaccharide solution. In the presence of xanthan gum (XG), the viscoelastic behavior of PL-based hydrogels was improved in aqueous environment, but the rheological behavior was less changed with the addition of XG in PBS solutions, whereas in the presence of 0.1 M NaCl, the viscoelastic parameters decreased. PL micellar networks exhibited a self-healing ability, recovering their initial structure after applying cycles of high strain. The rheological characteristics of the PL hydrogel changed with the addition of 1% polysaccharides (xanthan gum, alginate, κ-carrageenan, gellan, or chitosan). PL/polysaccharide systems form temperature-responsive hydrogels with shear thinning behavior, yield stress, and self-healing ability, being considered a versatile platform for injectable biomaterials or bioinks. Thus, in the presence of xanthan gum in aqueous medium, the gel strength was improved after applying a high strain (the values of elastic modulus increased). The other investigated natural polymers induced specific self-healing behaviors. Good performances were observed with the addition of gellan gum, alginate, and κ-carrageenan, but for high values of strain, the ability to recover the initial structure decreased. A modest self-healing behavior was observed in the presence of chitosan and xanthan gum dissolved in NaCl solution.
Collapse
Affiliation(s)
- Alexandra Lupu
- “Petru Poni” Institute of Macromolecular Chemistry, 41-A Grigore Ghica Voda Alley, 700487 Iasi, Romania; (L.M.G.); (D.R.)
| | | | | | - Maria Bercea
- “Petru Poni” Institute of Macromolecular Chemistry, 41-A Grigore Ghica Voda Alley, 700487 Iasi, Romania; (L.M.G.); (D.R.)
| |
Collapse
|
8
|
Abstract
In this review, today's state of the art in the rheology of gels and transition through the yield stress of yielding liquids is discussed. Gels are understood as soft viscoelastic multicomponent solids that are in the incomplete phase separation state, which, under the action of external mechanical forces, do not transit into a fluid state but rupture like any solid material. Gels can "melt" (again, like any solids) due to a change in temperature or variation in the environment. In contrast to this type of rheology, yielding liquids (sometimes not rigorously referred to as "gels", especially in relation to colloids) can exist in a solid-like (gel-like) state and become fluid above some defined stress and time conditions (yield stress). At low stresses, their behavior is quite similar to that of permanent solid gels, including the frequency-independent storage modulus. The gel-to-sol transition considered in colloid chemistry is treated as a case of yielding. However, in many cases, the yield stress cannot be assumed to be a physical parameter since the solid-to-liquid transition happens in time and is associated with thixotropic effects. In this review, special attention is paid to various time effects. It is also stressed that plasticity is not equivalent to flow since (irreversible) plastic deformations are determined by stress but do not continue over time. We also discuss some typical errors, difficulties, and wrong interpretations of experimental data in studies of yielding liquids.
Collapse
Affiliation(s)
- Alexander Ya. Malkin
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninskii Prosp. 29, 119991 Moscow, Russia;
| | - Svetlana R. Derkach
- Laboratory of Chemistry and Technology of Marine Bioresources, Institute of Natural Science and Technology, Murmansk State Technical University, 183010 Murmansk, Russia;
| | - Valery G. Kulichikhin
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninskii Prosp. 29, 119991 Moscow, Russia;
| |
Collapse
|
9
|
Noda M, Adachi K, Takahara S. A Scientific Proposal for Surgical Decision-Making in Occult Intertrochanteric Fractures Based on Finite Element Analysis. Cureus 2023; 15:e44491. [PMID: 37791154 PMCID: PMC10544485 DOI: 10.7759/cureus.44491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2023] [Indexed: 10/05/2023] Open
Abstract
Background In the treatment of femoral intertrochanteric fractures, there is still a lack of consensus on the optimal approach for isolated greater trochanteric fractures and insufficient intertrochanteric fractures. The limited number of patients and restricted access to accurate assessment of fracture extension using magnetic resonance imaging contribute to the unclear treatment strategy. This study aims to utilize finite element (FE) analysis to analyze stress values at the fracture line and investigate their influence on intertrochanteric fracture extension under different loading conditions. The hypothesis is that fracture extension occurs following certain conditions, supporting the need for surgery based on scientific evidence. Methodology Osseous data from a computed tomography (CT) scan was used to create a proximal femur FE model using FEA software. CT scan data were converted to Digital Imaging and Communications in Medicine format and used to generate the FE model. Trabecular bone and cortex were meshed into tetrahedral elements. The model consisted of 1,592,642 elements and 282,530 nodes. Two models were created, namely, healthy proximal femur (HF) and femoral insufficient intertrochanteric fracture (FIF). Material properties were assigned based on CT values and conversion equations. The distal end of the femur was constrained. Stress analysis using the dynamic explicit approach was performed. Von Mises stresses were calculated for the proximal femur. The number of elements exceeding yield stress was counted to predict fracture risk by focusing on fracture line spots. In this study, the distribution of von Mises stress was compared between the HF and the FIF models. Six loading combinations were considered, namely, two weight-bearing conditions (3 W loading simulating for walking and 1/3 W for touch-down standing) and three hip flexion angles (0°, 15°, and 23°). Results Under 3 W loading, no significant stress elevations were observed in the HF model at any flexion angles. However, the FIF model exhibited increased stress at the site of the posterior fracture line extension. This stress-induced element destruction was observed in both cortical and cancellous bone. For the 1/3 W loading condition, only minimal stress elevation was observed in both HF and FIF models. To assess the influence on fracture extension, the number of yielded elements was evaluated along the fracture line edges (greater trochanter and middle of the intertrochanteric ridge). Under 3 W loading, the HF model had only one yielded element, indicating minimal fracture risk. In contrast, the FIF model exhibited a notable presence of yield elements in various regions (total/greater trochanter/shaft) at different flexion angles: 0° (115/16/28), 15° (265/158/23), and 23° (446/233/34). Under the 1/3 W loading condition, neither the HF nor the FIF models showed any yielding elements, regardless of the direction of external force. Conclusions The results demonstrated elevated stress levels at the fracture line in the FIF model, particularly during walking, indicating a higher risk of fracture extension at the flex position. However, under reduced weight-bearing conditions, the stress at the fracture site remained within the yield stress range, suggesting a relatively low risk of fracture extension. These findings hold significant clinical implications for developing surgical protocols that consider patients' compliance with weight-bearing restrictions.
Collapse
Affiliation(s)
| | - Kazuhiko Adachi
- Department of Mechanical Engineering, Chubu University, Kasugai, JPN
| | - Shunsuke Takahara
- Department of Orthopaedics, Hyogo Prefectural Kakogawa Medical Center, Kakogawa, JPN
| |
Collapse
|
10
|
Yasuda T, Shimokasa K. Improved system for measuring rheological properties of thickened liquid using an inclined parallel plate and optical sensor. J Texture Stud 2023; 54:510-520. [PMID: 37144497 DOI: 10.1111/jtxs.12758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 04/06/2023] [Accepted: 04/08/2023] [Indexed: 05/06/2023]
Abstract
The purpose of this study was to improve the method of using an inclined parallel plate (IPP) in directly estimating the yield stressτ iy and evaluating the properties of a thickened liquid. The flow curve of the relationship between the shear rate and shear stress of a liquid thickened with a xanthan gum agent was predicted using the Herschel-Bulkley fluid model ( τ = τ y + k γ ˙ n - 1 ). We supposed that the yield stressτ y and the result of a line spread test (LST) indicate the deformation state and the flow state of shear stress ( k γ ˙ n - 1 ), respectively.τ iy , the yield stressτ ry estimated adopting a rotational viscometer and LST, was investigated for three liquids thickened with xanthan gum at four concentrations (C) at intervals of 0.5 wt% within the range 0.5-2.0 wt%. Linear plots of the relations of C versusτ iy andτ ry and the LST show that with an increase in C , the resistance force (τ ry andτ iy ) increases until flow starts, after which viscosity increases. We suggest that yield stressτ iy estimated with the IPP method effectively indicates the rheological properties of thickened liquids.
Collapse
Affiliation(s)
- Toshitaka Yasuda
- Department of Electronic Engineering, Tokyo National College of Technology, Hachioji, Japan
| | - Kenji Shimokasa
- Course of System Engineering, Division of Industrial Technology, Tsukuba University of Technology, Tsukuba, Japan
| |
Collapse
|
11
|
Jacquet Y, Perrot A. Sewing Concrete Device-Combining In-Line Rheology Control and Reinforcement System for 3D Concrete Printing. Materials (Basel) 2023; 16:5110. [PMID: 37512385 PMCID: PMC10384684 DOI: 10.3390/ma16145110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/16/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023]
Abstract
Of the digital concrete-additive-manufacturing techniques, extrusion-based systems are probably the most widespread and studied. Despite the significant potential offered by 3D printing, several challenges must still be overcome. For instance, although several solutions have already been explored, the automated reinforcement of the layer-wise printed structures represents a challenge. The inline quality control of the fresh-state properties of 3D-printed materials is also an open question that needs to be addressed to find an efficient shared practice. This study proposes a new device designed to simultaneously reinforce 3D-printed structures along and through the layers and to be used as an inline quality-control device. This device consists in a sewing system, which is composed of a rotating system, and a hollow needle, which drives a reinforcing cable or yarn and can be used to inject cement grout to fill holes and improve bonding with reinforcement. The rotation is induced by a stepper motor, which measures the torque that is required to make the needle penetrate. This measurement can be used as a quality-control index to ensure material homogeneity. This paper aims to present an original reinforcement system that can be fully automated and simultaneously create reinforcement patterns in different directions of the printed structure while controlling the material's fresh properties.
Collapse
Affiliation(s)
- Yohan Jacquet
- IRDL, UMR CNRS 6027, Université de Bretagne Sud, 56100 Lorient, France
| | - Arnaud Perrot
- IRDL, UMR CNRS 6027, Université de Bretagne Sud, 56100 Lorient, France
| |
Collapse
|
12
|
Bercea M. Rheology as a Tool for Fine-Tuning the Properties of Printable Bioinspired Gels. Molecules 2023; 28:molecules28062766. [PMID: 36985738 PMCID: PMC10058016 DOI: 10.3390/molecules28062766] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/12/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
Over the last decade, efforts have been oriented toward the development of suitable gels for 3D printing, with controlled morphology and shear-thinning behavior in well-defined conditions. As a multidisciplinary approach to the fabrication of complex biomaterials, 3D bioprinting combines cells and biocompatible materials, which are subsequently printed in specific shapes to generate 3D structures for regenerative medicine or tissue engineering. A major interest is devoted to the printing of biomimetic materials with structural fidelity after their fabrication. Among some requirements imposed for bioinks, such as biocompatibility, nontoxicity, and the possibility to be sterilized, the nondamaging processability represents a critical issue for the stability and functioning of the 3D constructs. The major challenges in the field of printable gels are to mimic at different length scales the structures existing in nature and to reproduce the functions of the biological systems. Thus, a careful investigation of the rheological characteristics allows a fine-tuning of the material properties that are manufactured for targeted applications. The fluid-like or solid-like behavior of materials in conditions similar to those encountered in additive manufacturing can be monitored through the viscoelastic parameters determined in different shear conditions. The network strength, shear-thinning, yield point, and thixotropy govern bioprintability. An assessment of these rheological features provides significant insights for the design and characterization of printable gels. This review focuses on the rheological properties of printable bioinspired gels as a survey of cutting-edge research toward developing printed materials for additive manufacturing.
Collapse
Affiliation(s)
- Maria Bercea
- "Petru Poni" Institute of Macromolecular Chemistry, 41-A Grigore Ghica Voda Alley, 700487 Iasi, Romania
| |
Collapse
|
13
|
Ghanaei A, Edris H, Monajati H, Hamawandi B. The Effect of Adding V and Nb Microalloy Elements on the Bake Hardening Properties of ULC Steel before and after Annealing. Materials (Basel) 2023; 16:1716. [PMID: 36837346 PMCID: PMC9959569 DOI: 10.3390/ma16041716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
Bake hardening (BH) is a vital part of special steel production. Studies in this field have focused on steels under homogeneous yielding, but until now, none have been conducted on the phenomena that occur for steels under heterogeneous yielding. In the current study, the effect of adding Nb and V alloying elements on the strength of ultra-low carbon (ULC) steel after bake hardening was investigated. The effects of pre-strain, grain size, and recrystallization annealing temperature were analyzed, as well as the effect of Nb and V on the yield stress caused by the bake hardening process. For this purpose, five types of alloys with different V and Nb contents were melted, cast in an induction furnace, and subjected to hot hammering and hot rolling. Then, cold rolling was applied to the samples by ~80%. To eliminate the effects of cold working, tensile samples were subjected to recrystallization annealing at 750 and 800 °C for 30 min, and the samples were quickly quenched in a mixture of a NaCl solution and ice. The annealed samples were subjected to a pre-tensile strain in the range of 2-12% and then aged in a silicone oil bath at 180 °C for 30 min. Then they were subjected to a tensile test. The obtained results showed that with the increase of the pre-strain and the annealing temperature, the values of baking hardness increased. The presence of V in the composition of steel reduced the annealing temperature.
Collapse
Affiliation(s)
- Afshin Ghanaei
- Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad 85141-43131, Iran
| | - Hossein Edris
- Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Hossein Monajati
- Department of Mechanical Engineering, Ecole de Technologie Supérieure, 1100 Notre-Dame Street West, Montreal, QC H3C 1K3, Canada
| | - Bejan Hamawandi
- Department of Applied Physics, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| |
Collapse
|
14
|
Nieto S, Piceros E, Toledo PG, Robles P, Jeldres R. Compressive Yield Stress of Flocculated Kaolin Suspensions in Seawater. Polymers (Basel) 2023; 15:polym15030530. [PMID: 36771831 PMCID: PMC9919725 DOI: 10.3390/polym15030530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/09/2022] [Accepted: 12/22/2022] [Indexed: 01/22/2023] Open
Abstract
The mining industry has resorted to using seawater while trying to find a solution to the water shortage, which is severe in some regions. Today, the industry looks to tailings dams to recover more water and, thus, increase recirculation. The migration of interstitial water due to the consolidation of particle networks can give rise to large water mirrors in different dam areas. These pools can contain enough water to be recovered and recirculated if the external stress caused by the weight of the pulp exceeds the compressive yield stress. The density and rheological properties of the discarded pulps determine the feasibility of water expulsion during tailings consolidation. As these conditions are largely established in the thickening stage, it is necessary to revisit operations, looking at the dam as a water source. Thus, a thorough understanding of the compressive properties that determine the level of consolidation of typical pulps and their relationships to aggregate properties, such as size and fractal dimension, is crucial. Here, the effect of two types of water, industrial water and synthetic seawater, on kaolin flocculation, sedimentation rate, yield stress, and compressive yield stress were studied. In addition, the relationship of these properties with the flocculant dose and the resulting aggregate size and fractal dimension was examined. One promising finding to practitioners was that salt and small doses of high molecular weight flocculant improved the consolidation of kaolin slurries under compression. These conditions generated low compressive yield stress compared to fresh water and water with low salt content, favoring the consolidation of the pulps and the release of water.
Collapse
Affiliation(s)
- Steven Nieto
- Departamento de Ingeniería Química y Procesos de Minerales, Facultad de Ingeniería, Universidad de Antofagasta, Antofagasta 1240000, Chile
| | - Eder Piceros
- Departamento de Ingeniería Química y Procesos de Minerales, Facultad de Ingeniería, Universidad de Antofagasta, Antofagasta 1240000, Chile
- Faculty of Engineering and Architecture, Universidad Arturo Prat, Antofagasta 1240000, Chile
| | - Pedro G. Toledo
- Department of Chemical Engineering and Laboratory of Surface Analysis (ASIF), Universidad de Concepción, Concepción 4030000, Chile
- Correspondence: (P.G.T.); (R.J.)
| | - Pedro Robles
- Escuela de Ingeniería Química, Pontificia Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Ricardo Jeldres
- Departamento de Ingeniería Química y Procesos de Minerales, Facultad de Ingeniería, Universidad de Antofagasta, Antofagasta 1240000, Chile
- Correspondence: (P.G.T.); (R.J.)
| |
Collapse
|
15
|
Akatsu T, Tabata Y, Shinoda Y, Wakai F. Effect of Equibiaxial Pre-Stress on Mechanical Properties Evaluated Using Depth-Sensing Indentation with a Point-Sharp Indenter. Materials (Basel) 2023; 16:528. [PMID: 36676264 PMCID: PMC9867346 DOI: 10.3390/ma16020528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/05/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
This study examined the effect of an imposed equibiaxial pre-stress (EBPS) on the evaluation of mechanical properties, using the depth-sensing indentation method with a point-sharp indenter, through a numerical analysis of indentations simulated with the 3D finite element method. The predicted elastic modulus, E*, and yield stress, Y*, were used as elastic and plastic deformation resistances under the indentation, respectively. It was found that both increased nominally with the increase in compressive EBPS and decreased with the increase in tensile EBPS, even though the induced change in the piling-up or sinking-in around the indentations was not significant. The effect of EBPS on E* was described by the Hooke's law for an isotropic elastoplastic material, whereas that on Y* was accounted for by the change in the von Mises stress due to EBPS.
Collapse
Affiliation(s)
- Takashi Akatsu
- Faculty of Art and Regional Design, Saga University, 2441-1 Oono-otsu, Arita-cho, Nishimatsuura-gun, Saga 844-0013, Japan
| | - Yoshihide Tabata
- Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, R3-24 4259 Nagatsuta, Midori, Yokohama 226-8503, Japan
| | - Yutaka Shinoda
- National Institute of Technology, Ube College, 2-14-1 Tokiwadai, Ube, Yamaguchi 755-8555, Japan
| | - Fumihiro Wakai
- Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, R3-24 4259 Nagatsuta, Midori, Yokohama 226-8503, Japan
| |
Collapse
|
16
|
Srinivas D, Dey D, Panda B, Sitharam TG. Printability, Thermal and Compressive Strength Properties of Cementitious Materials: A Comparative Study with Silica Fume and Limestone. Materials (Basel) 2022; 15:ma15238607. [PMID: 36500103 PMCID: PMC9737608 DOI: 10.3390/ma15238607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/21/2022] [Accepted: 11/29/2022] [Indexed: 05/27/2023]
Abstract
Over the past decade, 3D printing in the construction industry has received worldwide attention and developed rapidly. The research and development of cement and concrete products has also become quite well-established over the years, while other sustainable materials receive considerably lower attention in comparison. This study aims to investigate the influence of the two most commonly used sustainable cementitious materials i.e., silica fume and limestone powder, on printability, thermal and mechanical properties of fly ash-Portland cement blends. Ternary blends containing Portland cement, fly ash and silica fume or limestone powder are prepared, whereas phase change material (PCM) is introduced to improve the thermal behavior. Based on the rheological properties and concurrent 3D concrete printing, improved buildability of the modified mixtures is linked to their static yield stress. Anisotropic mechanical properties are observed for 3D printed specimens, while cast specimens exhibit a maximum 41% higher compressive strength due to better material compaction. It is clear from the results that addition of silica fume and limestone powder ranged from 5% to 10%, reducing the anisotropic mechanical properties (maximum 71% and 68% reduction in anisotropic factor, respectively) in the printed specimens. The PCM addition ranged from 5% to 10% and improved thermal performance of the mixtures, as measured by a decrease in thermal conductivity (9% and 13%) and an increase in volumetric heat capacity (9% and 10%), respectively. However, the PCM-containing mixtures show around 29% reduction in compressive strength, compared to the control specimen, which necessitates new material design considering matrix strengthening methods.
Collapse
Affiliation(s)
- Dodda Srinivas
- Centre for Intelligent Cyber Physical Systems, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Dhrutiman Dey
- Sustainable Resources for Additive Manufacturing (SreAM) Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Biranchi Panda
- Centre for Intelligent Cyber Physical Systems, Indian Institute of Technology Guwahati, Guwahati 781039, India
- Sustainable Resources for Additive Manufacturing (SreAM) Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Thallak G. Sitharam
- Centre for Intelligent Cyber Physical Systems, Indian Institute of Technology Guwahati, Guwahati 781039, India
- Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| |
Collapse
|
17
|
Liu J, An M, Wang Y, Han S, Yu Z. Research on the Relation between Slump Flow and Yield Stress of Ultra-High Performance Concrete Mixtures. Materials (Basel) 2022; 15:8104. [PMID: 36431590 PMCID: PMC9696067 DOI: 10.3390/ma15228104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/08/2022] [Accepted: 11/12/2022] [Indexed: 06/16/2023]
Abstract
The relation between slump flow and yield stress of ultra-high performance concrete (UHPC) mixtures was studied with theoretical analysis and experimentation. The relational expression between slump flow and yield stress of UHPC mixtures was built and then verified with a rheological test. The results showed that the prediction model, as a function of cone geometry of dimensionless slump flow and dimensionless yield stress of the UHPC mixtures, was constructed based on Tresca criteria, considering the geometric relation of morphological characterization parameters before and after slump of the UHPC mixtures. The rationality and applicability of the dimensionless prediction model was verified with a rheological test and a slump test of UHPC mixtures with different dosages of polycarboxylate superplasticizer. With increase in polycarboxylate superplasticizer dosage, yield stress of the two series of UHPC mixtures (large/small binding material consumption) gradually decreased, leading to a gradual increase in slump flow. Based on the prediction model of dimensionless slump flow and dimensionless yield stress, the relational expression between slump flow and yield stress of the UHPC mixtures was built. The comparison result showed that the calculated data was consistent with the experimental data, which provided a new method for predicting yield stress of UHPC mixtures with a slump test.
Collapse
|
18
|
Rajagopalan SR, Lee BY, Kang ST. Prediction of the Rheological Properties of Fresh Cementitious Suspensions Considering Microstructural Parameters. Materials (Basel) 2022; 15:ma15207044. [PMID: 36295112 PMCID: PMC9605141 DOI: 10.3390/ma15207044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/23/2022] [Accepted: 10/08/2022] [Indexed: 05/27/2023]
Abstract
Supplementary cementitious materials (SCMs) are commonly used to partially replace cements. Although it is necessary to investigate the rheological properties of the individual supplementary cementitious materials (SCMs) for understanding complex rheological behaviors of the blended mixes, the study on the investigation of rheological properties of various SCMs such as fly ash, blast-furnace slag, and silica fume, according to various solid volume fractions and prediction models is fairly limited. This study investigated the rheological properties of non-blended cementitious suspensions with Portland cement (PC), fly ash (FA), blast-furnace slag (BS), and silica fume (SF) materials in the experiments and predicted using YODEL (Yield stress mODEL) and Krieger-Dougherty's (K-D's) equation. Experiments were designed with various solid volume fractions (ϕ) from 0.28 to 0.44, and the rheological properties of all cementitious suspensions were noted to increase with increasing ϕ, showing an improved flowability at low ϕ. YODEL, derived from the first principles considering particle-size distributions, interparticle forces and microstructural parameters predicted the yield stress. The YODEL predictions were consistent with the experiments with a positive correlation coefficient of above 0.96. K-D's equation with the maximum particle fractions and intrinsic viscosity as key parameters predicted the plastic viscosity. The K-D's equation predictions match up with the experiments with a positive correlation coefficient of above 0.94. Both models showed more quantitative predictions without any fitting parameters and could be applied to any multimodal powder suspensions.
Collapse
Affiliation(s)
- Sam Rajadurai Rajagopalan
- Department of Civil Engineering, Daegu University, 201 Daegudae-ro, Jillyang, Gyeongsan 38453, Korea
| | - Bang-Yeon Lee
- School of Architecture, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, Korea
| | - Su-Tae Kang
- Department of Civil Engineering, Daegu University, 201 Daegudae-ro, Jillyang, Gyeongsan 38453, Korea
| |
Collapse
|
19
|
Qi G, Yan H, Qi D, Li H, Zhang Z. The Aging Performance of PVDF in Acid Oil and Gas Medium. Polymers (Basel) 2022; 14:4244. [PMID: 36236191 DOI: 10.3390/polym14194244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 09/22/2022] [Accepted: 09/30/2022] [Indexed: 11/17/2022] Open
Abstract
In the process of transporting oil and gas, the service performance of thermoplastic pipes will decline due to the multiple influences of medium, temperature, and pressure. In order to study the service performance changes of PVDF pipes under oil and gas transportation conditions, the high-temperature autoclave is used to simulate the service state of the pipe in the mediums. The PVDF samples are exposed to simulated oil and gas mediums for 1 week, 3 weeks, 5 weeks, and 7 weeks under 60 °C and 90 °C conditions. After the exposure test, the physical and chemical properties of the PVDF pipe are tested and compared with the initial samples. Compared with the initial sample, the sample quality after the exposure test has a slight increase, with growth rates of 2% and 3% at 60 °C and 90 °C, respectively. Meanwhile, the tensile strength of the samples is about 13% and 21% lower than that of the initial sample, respectively. According to the microscopic morphology analyses, there are some crack defects on the surface of the sample after the exposure test. Through infrared analysis, it is shown that no molecular chain breakage, crosslinking, or other reactions are found after the exposure test. The above analysis shows that the PVDF sample has slight penetration and swelling during the exposure test. However, due to the large force between the PVDF molecules, its mechanical properties have a small downward trend, showing excellent environmental stress crack resistance.
Collapse
|
20
|
Yue Y, Ren J, Yang K, Wang D, Qian J, Bai Y. Investigation and Optimisation of the Rheological Properties of Magnesium Potassium Phosphate Cement with Response Surface Methodology. Materials (Basel) 2022; 15:6815. [PMID: 36234160 PMCID: PMC9573288 DOI: 10.3390/ma15196815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 09/12/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
Magnesium phosphate cement (MPC) is a promising alternative cement. However, the rheological property of this new binder is still to be explored. In this study, Response Surface Methodology (RSM) was adopted with Central Composite Design (CCD) to establish mathematical models describing the rheological characteristics of MPC in terms of initial mini slump (Y1), mini-slump loss (Y2), yield stress (Y3) and plastic viscosity (Y4), as a function of three independent variables, namely, water-to-solid ratio (W/S ratio, X1), MgO to MKP ratio (M/P ratio, X2) and borax dosage (X3). The results show that the M/P ratio and borax dosage could significantly affect the yield stress and mini-slump loss of MPC, while the W/S ratio was the significant coefficient influencing plastic viscosity and initial mini slump. The numerical optimised values of X1, X2 and X3 were 0.280, 7.528 and 0.170, respectively, and an MPC paste with desirable rheological characteristics (Y1 161.858 mm, Y2 11.282, Y3 0.680 Pa, Y4 0.263 Pa·s) with the highest desirability of 0.867 can be obtained.
Collapse
Affiliation(s)
- Yanfei Yue
- College of Materials Science and Engineering, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China
| | - Jun Ren
- School of Architecture and Planning, Yunnan University, Kunming 650051, China
- Department of Civil, Environmental and Geomatic Engineering, University College London, Gower Street, London WC1E 6BT, UK
| | - Kai Yang
- College of Materials Science and Engineering, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China
- School of Civil Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK
| | - Danqian Wang
- College of Materials Science and Engineering, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China
- Department of Civil, Environmental and Geomatic Engineering, University College London, Gower Street, London WC1E 6BT, UK
| | - Jueshi Qian
- College of Materials Science and Engineering, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China
| | - Yun Bai
- Department of Civil, Environmental and Geomatic Engineering, University College London, Gower Street, London WC1E 6BT, UK
| |
Collapse
|
21
|
Konan NA, Rosenbaum E, Massoudi M. On the Response of a Herschel-Bulkley Fluid Due to a Moving Plate. Polymers (Basel) 2022; 14:polym14183890. [PMID: 36146036 PMCID: PMC9502123 DOI: 10.3390/polym14183890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/08/2022] [Accepted: 09/10/2022] [Indexed: 11/16/2022] Open
Abstract
In this paper, we study the boundary-layer flow of a Herschel-Bulkley fluid due to a moving plate; this problem has been experimentally investigated by others, where the fluid was assumed to be Carbopol, which has similar properties to cement. The computational fluid dynamics finite volume method from the open-source toolbox/library OpenFOAM is used on structured quad grids to solve the mass and the linear momentum conservation equations using the solver "overInterDyMFoam" customized with non-Newtonian viscosity libraries. The governing equations are solved numerically by using regularization methods in the context of the overset meshing technique. The results indicate that there is a good comparison between the experimental data and the simulations. The boundary layer thicknesses are predicted within the uncertainties of the measurements. The simulations indicate strong sensitivities to the rheological properties of the fluid.
Collapse
Affiliation(s)
- N’dri Arthur Konan
- U.S. Department of Energy, National Energy Technology Laboratory (NETL), 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA
- NETL Support Contractor, 3610 Collins Ferry Road, Morgantown, WV 26507, USA
| | - Eilis Rosenbaum
- U.S. Department of Energy, National Energy Technology Laboratory (NETL), 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA
| | - Mehrdad Massoudi
- U.S. Department of Energy, National Energy Technology Laboratory (NETL), 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA
- Correspondence:
| |
Collapse
|
22
|
Karyappa R, Goh WH, Hashimoto M. Embedded Core-Shell 3D Printing (eCS3DP) with Low-Viscosity Polysiloxanes. ACS Appl Mater Interfaces 2022; 14:41520-41530. [PMID: 36048005 DOI: 10.1021/acsami.2c09041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Flexible core-shell 3D structures are essential for the development of soft sensors and actuators. Despite recent advancements in 3D printing, the fabrication of flexible 3D objects with internal architectures (such as channels and void spaces) remains challenging with liquid precursors due to the difficulty to maintain the printed structures. The difficulty of such fabrication is prominent especially when low-viscosity polysiloxane resins are used. This study presents a unique approach to applying direct ink writing (DIW) 3D printing in a three-phase system to overcome this limitation. We performed core-shell 3D printing using a low-viscosity commercial polysiloxane resin (Ecoflex 10) as shell inks combined with a coaxially extruded core liquid (Pluronic F127) in Bingham plastic microparticulate gels (ethanol gel). In the process termed embedded core-shell 3D printing (eCS3DP), we highlighted the dependence of the rheological characteristics of the three fluids on the stability of the printed core-shell filament. With the core liquid with a sufficiently high concentration of Pluronic F127 (30 w/w%; σy = 158.5 Pa), the interfacial instability between the shell liquid and core liquid was suppressed; the removal of the core liquid permitted the fabrication of perfusable channels. We identified the printing conditions to ensure lateral attachments of printed core-shell filaments. Interestingly, judicious selection of the rheological properties and flow rates of three phases allowed the formation of droplets consisting of core liquids distributed along the printed filaments. eCS3DP offers a simple route to fabricate 3D structures of a soft elastomeric matrix with embedded channels and should serve as a useful tool for DIW-based fabrication of flexible wearable devices and soft robotic components.
Collapse
Affiliation(s)
- Rahul Karyappa
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis, Singapore 138634, Singapore
- Digital Manufacturing and Design Centre, Singapore University of Technology and Design, 8, Somapah Road, Singapore 487372, Sinagapore
| | - Wei Huang Goh
- Digital Manufacturing and Design Centre, Singapore University of Technology and Design, 8, Somapah Road, Singapore 487372, Sinagapore
| | - Michinao Hashimoto
- Digital Manufacturing and Design Centre, Singapore University of Technology and Design, 8, Somapah Road, Singapore 487372, Sinagapore
- Pillar of Engineering Product Development, Singapore University of Technology and Design, 8, Somapah Road, Singapore 487372, Singapore
| |
Collapse
|
23
|
Bui CM, Ho ANT, Nguyen XB. Flow Behaviors of Polymer Solution in a Lid-Driven Cavity. Polymers (Basel) 2022; 14:polym14122330. [PMID: 35745906 PMCID: PMC9228522 DOI: 10.3390/polym14122330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/02/2022] [Accepted: 06/02/2022] [Indexed: 02/07/2023] Open
Abstract
In this work, a numerical study of polymer flow behaviors in a lid-driven cavity, which is inspired by the coating process, at a broad range of Oldroyd numbers (0≤Od≤50), is carried out. The Reynolds number is height-based and kept at Re=0.001. The fluid investigated is of Carbopol gel possessing yield stress and shear-thinning properties. To express rheological characteristics, the Herschel–Bulkley model cooperated with Papanastasiou’s regularization scheme is utilized. Results show that the polymer flow characteristics, i.e., velocity, viscosity, and vortex distributions, are considerably influenced by viscoplastic behaviors. Additionally, there exist solid-like regions which can be of either moving rigid or static dead types in the flow patterns; they become greater and tend to merge together to construct larger ones when Od increases. Furthermore, various polymer flow aspects in different cavity configurations are discussed and analyzed; the cavity width/aspect ratio and skewed angle are found to have significant impacts on the vortex structures and the formation of solid-like regions. Moreover, results for the critical aspect ratio at which the static dead zone is broken into two parts and the characteristic height of this zone are also reported in detail.
Collapse
|
24
|
Serial MR, Arnaudov LN, Stoyanov S, Dijksman JA, Terenzi C, van Duynhoven JPM. Non-Invasive Rheo-MRI Study of Egg Yolk-Stabilized Emulsions: Yield Stress Decay and Protein Release. Molecules 2022; 27:molecules27103070. [PMID: 35630546 PMCID: PMC9146701 DOI: 10.3390/molecules27103070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/19/2022] [Accepted: 04/23/2022] [Indexed: 02/04/2023] Open
Abstract
A comprehensive understanding of the time-dependent flow behavior of concentrated oil-in-water emulsions is of considerable industrial importance. Along with conventional rheology measurements, localized flow and structural information are key to gaining insight into the underlying mechanisms causing time variations upon constant shear. In this work, we study the time-dependent flow behavior of concentrated egg-yolk emulsions with (MEY) or without (EY) enzymatic modification and unravel the effects caused by viscous friction during shear. We observe that prolonged shear leads to irreversible and significant loss of apparent viscosity in both emulsion formulations at a mild shear rate. The latter effect is in fact related to a yield stress decay during constant shearing experiments, as indicated by the local flow curve measurements obtained by rheo-MRI. Concurrently, two-dimensional D-T2 NMR measurements revealed a decrease in the T2 NMR relaxation time of the aqueous phase, indicating the release of surface-active proteins from the droplet interface towards the continuous water phase. The combination of an increase in droplet diameter and the concomitant loss of proteins aggregates from the droplet interface leads to a slow decrease in yield stress.
Collapse
Affiliation(s)
- Maria R. Serial
- Laboratory of Biophysics, Wageningen University, 6708WE Wageningen, The Netherlands; (M.R.S.); (C.T.)
| | - Luben N. Arnaudov
- Unilever Global Food Innovation Centre, 6708WE Wageningen, The Netherlands; (L.N.A.); (S.S.)
| | - Simeon Stoyanov
- Unilever Global Food Innovation Centre, 6708WE Wageningen, The Netherlands; (L.N.A.); (S.S.)
- Physical Chemistry and Soft Matter, Wageningen University and Research, 6708WE Wageningen, The Netherlands;
| | - Joshua A. Dijksman
- Physical Chemistry and Soft Matter, Wageningen University and Research, 6708WE Wageningen, The Netherlands;
| | - Camilla Terenzi
- Laboratory of Biophysics, Wageningen University, 6708WE Wageningen, The Netherlands; (M.R.S.); (C.T.)
| | - John P. M. van Duynhoven
- Laboratory of Biophysics, Wageningen University, 6708WE Wageningen, The Netherlands; (M.R.S.); (C.T.)
- Unilever Global Food Innovation Centre, 6708WE Wageningen, The Netherlands; (L.N.A.); (S.S.)
- Correspondence:
| |
Collapse
|
25
|
Alasfar RH, Ahzi S, Barth N, Kochkodan V, Khraisheh M, Koç M. A Review on the Modeling of the Elastic Modulus and Yield Stress of Polymers and Polymer Nanocomposites: Effect of Temperature, Loading Rate and Porosity. Polymers (Basel) 2022; 14:polym14030360. [PMID: 35160350 PMCID: PMC8838186 DOI: 10.3390/polym14030360] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/09/2022] [Accepted: 01/11/2022] [Indexed: 11/20/2022] Open
Abstract
Porous polymer-based nanocomposites have been used for various applications due to their advantages, including multi-functionalities, easy and known manufacturability, and low cost. Understanding of their mechanical properties has become essential to expand the nanocomposites’ applications and efficiency, including service-life, resistance to different loads, and reliability. In this review paper, the focus is on the modeling of the mechanical properties of porous polymer-based nanocomposites, including the effects of loading rates, operational temperatures, and the material’s porosity. First, modeling of the elastic modulus and yield stress for glassy polymers and polymer reinforced by nanofillers are addressed. Then, modeling of porosity effects on these properties for polymers are reviewed, especially via the use of the well-known power-law approach linking porosity to elastic modulus and/or stress. Studies related to extending the mechanical modeling to account for porosity effects on the elastic modulus and yield stress of polymers and polymer-nanocomposites are discussed. Finally, a brief review of the implementation of this modeling into 3D computational methods to predict the large elastic-viscoplastic deformation response of glassy polymers is presented. In addition to the modeling part, the experimental techniques to measure the elastic modulus and the yield stress are discussed, and applications of polymers and polymer composites as membranes for water treatment and scaffolds for bone tissue engineering are addressed. Some modeling results and validation from different studies are presented as well.
Collapse
Affiliation(s)
- Reema H. Alasfar
- Division of Sustainable Development, College of Science and Engineering, Hamad bin Khalifa University, Doha P.O. Box 34110, Qatar;
- Correspondence:
| | - Said Ahzi
- Mechanical Engineering Program, Texas A&M University at Qatar, Doha P.O. Box 34110, Qatar; (S.A.); (M.K.)
| | - Nicolas Barth
- Qatar Environment and Energy Research Institute, Hamad bin Khalifa University, Doha P.O. Box 34110, Qatar; (N.B.); (V.K.)
| | - Viktor Kochkodan
- Qatar Environment and Energy Research Institute, Hamad bin Khalifa University, Doha P.O. Box 34110, Qatar; (N.B.); (V.K.)
| | - Marwan Khraisheh
- Mechanical Engineering Program, Texas A&M University at Qatar, Doha P.O. Box 34110, Qatar; (S.A.); (M.K.)
| | - Muammer Koç
- Division of Sustainable Development, College of Science and Engineering, Hamad bin Khalifa University, Doha P.O. Box 34110, Qatar;
| |
Collapse
|
26
|
He J, Cheng C, Zhu X, Li X. Effect of Silica Fume on the Rheological Properties of Cement Paste with Ultra-Low Water Binder Ratio. Materials (Basel) 2022; 15:554. [PMID: 35057270 DOI: 10.3390/ma15020554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/16/2021] [Accepted: 12/26/2021] [Indexed: 02/04/2023]
Abstract
The effect of silica fume on the rheological properties of a cement-silica fume-high range water reducer-water mixture with ultra-low water binder ratio (CSHWM) was studied. The results indicate that the W/B ratio and silica fume content have different effects on the rheological parameters, including the yield stress, plastic viscosity, and hysteresis loop area. The shear-thickening influence of CSHWM decreased with the increased silica fume content. When the silica fume content increased from 0% to 35%, the mixture with W/B ratio of 0.19 and 0.23 changed from a dilatant fluid to a Newtonian fluid, and then to a pseudoplastic fluid. When the silica fume content was less than 15%, the yield stress was close to 0. With the increase of silica fume content, the yield stress increased rapidly. The plastic viscosity and hysteresis loop area decreased slightly with the addition of a small amount of silica fume, but increased significantly with the continuous increase of silica fume. Compared with the Bingham and modified Bingham models, the Herschel-Buckley model is more applicable for this CSHWM.
Collapse
|
27
|
Mahmood R, Hussain Majeed A, Ain QU, Awrejcewicz J, Siddique I, Shahzad H. Computational Analysis of Fluid Forces on an Obstacle in a Channel Driven Cavity: Viscoplastic Material Based Characteristics. Materials (Basel) 2022; 15:ma15020529. [PMID: 35057249 PMCID: PMC8781405 DOI: 10.3390/ma15020529] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/29/2021] [Accepted: 01/06/2022] [Indexed: 11/16/2022]
Abstract
In the current work, an investigation has been carried out for the Bingham fluid flow in a channel-driven cavity with a square obstacle installed near the inlet. A square cavity is placed in a channel to accomplish the desired results. The flow has been induced using a fully developed parabolic velocity at the inlet and Neumann condition at the outlet, with zero no-slip conditions given to the other boundaries. Three computational grids, C1, C2, and C3, are created by altering the position of an obstacle of square shape in the channel. Fundamental conservation and rheological law for viscoplastic Bingham fluids are enforced in mathematical modeling. Due to the complexity of the representative equations, an effective computing strategy based on the finite element approach is used. At an extra-fine level, a hybrid computational grid is created; a very refined level is used to obtain results with higher accuracy. The solution has been approximated using P2 − P1 elements based on the shape functions of the second and first-order polynomial polynomials. The parametric variables are ornamented against graphical trends. In addition, velocity, pressure plots, and line graphs have been provided for a better physical understanding of the situation Furthermore, the hydrodynamic benchmark quantities such as pressure drop, drag, and lift coefficients are assessed in a tabular manner around the external surface of the obstacle. The research predicts the effects of Bingham number (Bn) on the drag and lift coefficients on all three grids C1, C2, and C3, showing that the drag has lower values on the obstacle in the C2 grid compared with C1 and C3 for all values of Bn. Plug zone dominates in the channel downstream of the obstacle with augmentation in Bn, limiting the shear zone in the vicinity of the obstacle.
Collapse
Affiliation(s)
- Rashid Mahmood
- Department of Mathematics, Air University, PAF Complex E-9, Islamabad 44000, Pakistan; (R.M.); (Q.u.A.)
| | - Afraz Hussain Majeed
- Department of Mathematics, Air University, PAF Complex E-9, Islamabad 44000, Pakistan; (R.M.); (Q.u.A.)
- Correspondence:
| | - Qurrat ul Ain
- Department of Mathematics, Air University, PAF Complex E-9, Islamabad 44000, Pakistan; (R.M.); (Q.u.A.)
| | - Jan Awrejcewicz
- Department of Automation, Biomechanics and Mechatronics, Lodz University of Technology, 1/15 Stefanowskiego, St., 90-924 Lodz, Poland;
| | - Imran Siddique
- Department of Mathematics, University of Management and Technology, Lahore 54770, Pakistan;
| | - Hasan Shahzad
- Faculty of Materials and Manufacturing, College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing 100124, China;
| |
Collapse
|
28
|
Fernandes C, Fakhari A, Tukovic Ž. Non-Isothermal Free-Surface Viscous Flow of Polymer Melts in Pipe Extrusion Using an Open-Source Interface Tracking Finite Volume Method. Polymers (Basel) 2021; 13:polym13244454. [PMID: 34961005 PMCID: PMC8706656 DOI: 10.3390/polym13244454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/08/2021] [Accepted: 12/11/2021] [Indexed: 11/28/2022] Open
Abstract
Polymer extrudate swelling is a rheological phenomenon that occurs after polymer melt flow emerges at the die exit of extrusion equipment due to molecular stress relaxations and flow redistributions. Specifically, with the growing demand for large scale and high productivity, polymer pipes have recently been produced by extrusion. This study reports the development of a new incompressible non-isothermal finite volume method, based on the Arbitrary Lagrangian–Eulerian (ALE) formulation, to compute the viscous flow of polymer melts obeying the Herschel–Bulkley constitutive equation. The Papanastasiou-regularized version of the constitutive equation is employed. The influence of the temperature on the rheological behavior of the material is controlled by the Williams–Landel–Ferry (WLF) function. The new method is validated by comparing the extrudate swell ratio obtained for Bingham and Herschel–Bulkley flows (shear-thinning and shear-thickening) with reference data found in the scientific literature. Additionally, the essential flow characteristics including yield-stress, inertia and non-isothermal effects were investigated.
Collapse
Affiliation(s)
- Célio Fernandes
- Institute for Polymers and Composites (IPC), Department of Polymer Engineering, Engineering School of the University of Minho, Campus of Azurém, 4800-058 Guimarães, Portugal
- Correspondence:
| | - Ahmad Fakhari
- Transport Phenomena Research Center (CEFT), Mechanical Engineering Department, Faculty of Engineering of the University of Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal;
| | - Željko Tukovic
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ulica Ivana Lučića 5, 10000 Zagreb, Croatia;
| |
Collapse
|
29
|
Rajadurai RS, Kang ST. Influence of Inter-Particle Distances on the Rheological Properties of Cementitious Suspensions. Materials (Basel) 2021; 14:ma14247869. [PMID: 34947462 PMCID: PMC8705157 DOI: 10.3390/ma14247869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/16/2021] [Accepted: 12/16/2021] [Indexed: 11/22/2022]
Abstract
Supplementary cementitious materials (SCMs), such as fly ash (FA), blast furnace slag (BS), and silica fume (SF), have been mostly used as a replacement for Portland cement (PC). Replacing the SCMs with cement can provide improved strength characteristics; however, their applicability depends on the flow characteristics of the fresh mixtures. In this study, the rheological performance of cementitious suspensions in paste scale with different water-to-solid (W/S) volume ratios, varied from 1.25, 1.50, 1.75, 2.00, 2.25, to 2.50, was evaluated. As a result of the rheological tests, the yield stress and plastic viscosity of PC, FA, BS, and SF suspensions decreased as the W/S ratio increased. This study also estimated the inter-particle distances of the cementitious suspensions, and their relationship to the rheological properties was established. The inter-particle distances of the PC, FA, BS, and SF suspensions were in the ranges of 5.74~14.67 µm, 5.18~11.66 µm, 3.82~9.34 µm, and 0.107~0.27 µm, respectively. For very fine particles with a large surface area, the sensitivity to the rheological properties was high and the sensitivity was low when the particle sizes increased, indicating that the rheological properties were more sensitive to fine particles.
Collapse
|
30
|
Silva ÂDM, Silva MM, Figueiredo H, Delgado I, Lopes PE, Paiva MC, Hilliou L. Rheologically Assisted Design of Conductive Adhesives for Stencil Printing on PCB. Materials (Basel) 2021; 14:7734. [PMID: 34947328 DOI: 10.3390/ma14247734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/06/2021] [Accepted: 12/13/2021] [Indexed: 11/17/2022]
Abstract
Driven by the need to deliver new, lead-free, eco-friendly solder pastes for soldering electronic components to Printed Circuit Boards (PCB), electrically conductive adhesives (ECAs) based on epoxy, carbon nanotubes (CNT), and exfoliated graphite (EG) were designed. The rheology of the adhesives prepared is paramount for the success of the deposition process, which is based on stencil printing. Thus, a rheological analysis of the process was first performed. Then, an experimental protocol was defined to assess the relevant viscoelastic characteristics of the adhesives for stencil printing application. Different composite formulations of epoxy/CNT/EG were produced. Their rheological characteristics were established following the designed protocol and benchmarked with a commercial solder paste. The thermal and electrical properties of the composite formulations were also characterized. As a result, a new, electrically conductive adhesive was delivered with potential to be an eco-friendly alternative to the solder paste currently used in stencil printing of PCB.
Collapse
|
31
|
Sadiq MA, Bahaidarah HMS. Numerical Study on Generalized Heat and Mass in Casson Fluid with Hybrid Nanostructures. Nanomaterials (Basel) 2021; 11:nano11102675. [PMID: 34685110 PMCID: PMC8541252 DOI: 10.3390/nano11102675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 11/16/2022]
Abstract
The rheological model for yield stress exhibiting fluid and the basic laws for fluid flow and transport of heat and mass are used for the formulation of problems associated with the enhancement of heat and mass due to dispersion of nanoparticles in Casson. The heat and mass transfer obey non-Fourier's laws and the generalized Fick's law, respectively. Model problems are incorporated by thermal relaxation times for heat and mass. Transfer of heat energy and relaxation time are inversely proportional, and the same is the case for mass transport and concentration relaxation time. A porous medium force is responsible for controlling the momentum thickness. The yield stress parameter and diffusion of momentum in Casson fluid are noticed to be inversely proportional with each other. The concentration gradient enhances the energy transfer, and temperature gradient causes an enhancement diffusion of solute in Casson fluid. FEM provides convergent solutions. The relaxation time phenomenon is responsible for the restoration of thermal and solutal changes. Due to that, the thermal and solutal equilibrium states can be restored. The phenomenon of yield stress is responsible for controlling the momentum boundary layer thickness. A porous medium exerts a retarding force on the flow, and therefore, a deceleration in flow is observed. The thermal efficiency of MoS2-SiO2-Casson fluid is greater than the thermal efficiency of SiO2-Casson fluid.
Collapse
Affiliation(s)
- Muhammad A. Sadiq
- Department of Mathematics, DCC-KFUPM, P.O. Box 5084, Dhahran 31261, Saudi Arabia
- Interdisciplinary Research Center for Hydrogen and Energy Storage, KFUPM, Dhahran 31261, Saudi Arabia
- Correspondence:
| | - Haitham M. S. Bahaidarah
- Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia;
| |
Collapse
|
32
|
Abu-Jdayil B, Ghannam M, Alsayyed Ahmed K, Djama M. The Effect of Biopolymer Chitosan on the Rheology and Stability of Na-Bentonite Drilling Mud. Polymers (Basel) 2021; 13:polym13193361. [PMID: 34641175 PMCID: PMC8512588 DOI: 10.3390/polym13193361] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 09/23/2021] [Accepted: 09/26/2021] [Indexed: 11/16/2022] Open
Abstract
The utilization of greens resources is a grand challenge for this century. A lot of efforts are paid to substitute toxic ingredients of the conventional drilling mud system with nontoxic natural materials. In this paper, the effect of the natural polymer chitosan on the rheology and stability of sodium-bentonite drilling mud was investigated in the polymer concentration range of 0.1–3.0 wt.%. Both the shear and time dependent rheological properties of pure chitosan, pure bentonite and bentonite–chitosan dispersions were studied. Moreover, zeta potential measurements were used to evaluate the stability of bentonite-chitosan suspension. Adding chitosan improved the natural properties of drilling mud, namely: yield stress, shear thinning, and thixotropy. The viscosity of bentonite suspension increased significantly upon the addition of chitosan in the concentration range of 0.5 to 3.0 wt.% forming network structure, which can be attributed to the interactions of hydrogen bonding between -OH clusters on the bentonite surface with the NH group in the chitosan structure. On the other hand, dispersed chitosan–bentonite suspension was observed at low chitosan concentration (less than 0.5 wt.%). Increasing both bentonite and chitosan concentrations led to the flocculation of the bentonite suspension, forming a continuous gel structure that was characterized by noteworthy yield stress. The desired drilling mud rheological behavior can be obtained with less bentonite by adding chitosan polymer and the undesirable effects of high solid clay concentration can be avoided.
Collapse
|
33
|
Yasuda T. Improvement of simplified inclined plane test for evaluation of thickened liquids by using optical sensor. J Texture Stud 2021; 53:86-92. [PMID: 34535896 DOI: 10.1111/jtxs.12632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/06/2021] [Accepted: 09/13/2021] [Indexed: 11/30/2022]
Abstract
The thickening management index for food for dysphagia is important in enabling recognition of the rheological properties of thickened liquids, including their static and dynamic properties. One of the static properties of these liquids is the yield stress. An improvement to the simplified inclined plane test is proposed here that involves use of an automatic system for measurement of the displacements of thickened liquids on an inclined plate. The aim of this study is to investigate the relationship between the displacements of the thickened liquids and the variable thickener concentrations using an optical sensor. To measure the displacement of each thickened liquid on a clear inclined plate, an optical sensor that has a 12-mm-long light receiving surface is selected to form a one-dimensional position-sensitive detector (1D-PSD) under the clear inclined plate. The relationship between the angle of inclination of the plate θ at which the maximum voltage occurred in the 1D-PSD and five thickener (xanthan gum) concentrations c, ranging from 1.0 to 3.0 wt% in steps of 0.5 wt%, was investigated. It was confirmed that an approximately linear plot was obtained under the condition that θ = 8.24 c + 0.18, with the correlation R = .99 (for n = 7). This result indicated that the optical sensor composed of the 1D-PSD can measure the displacements of thickened liquids with various thickener concentrations on the clear inclined plate automatically.
Collapse
Affiliation(s)
- Toshitaka Yasuda
- Department of Electronic Engineering, Tokyo National College of Technology, Tokyo, Japan
| |
Collapse
|
34
|
Tekle BH, Hertwig L, Holschemacher K. Rheology of Alkali-Activated Blended Binder Mixtures. Materials (Basel) 2021; 14:5405. [PMID: 34576626 DOI: 10.3390/ma14185405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 11/16/2022]
Abstract
Alkali-activated cement (AAC) is an alternative cement that has been increasingly studied over the past decades mainly because of its environmental benefits. However, most studies are on heat-cured AACs and are focused on mechanical properties. There is a lack of research on the fresh properties of ambient-cured AAC systems. This study investigates the rheological properties of ambient-temperature-cured alkali-activated blended binder mixtures activated with sodium silicate and sodium hydroxide solutions. The influence of binder amount, alkaline solid to binder ratio (AS/B), sodium silicate to sodium hydroxide solids ratio (SS/SH), and total water content to total solid (from the binding materials) ratio (TW/TS) on the rheological properties are investigated. The effect of borax as an admixture and silica fume as a replacement for fly ash is also investigated. The results showed that both the yield stress and plastic viscosity are mainly affected by the binder content and TW/TS ratio decreasing with the increase of each parameter. The yield stress increased with the increase of the SS/SH ratio. Borax significantly reduced the yield stress, while silica fume's effect was dependent on its dosage.
Collapse
|
35
|
Chalvatzi S, Papadopoulos GA, Kroustallas F, Cernat M, Skampardonis V, Marouda C, Fotiadou V, Psychas V, Poutahidis T, Leontides L, Fortomaris P. Claw Characteristics of Culled Sows from Three Farrow-to-Finish Greek Farms. Part 2: Mechanical Indices of Hoof Horn and Their Associations with Length Measurements and Lesion Scores. Vet Sci 2021; 8:175. [PMID: 34564569 DOI: 10.3390/vetsci8090175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 11/24/2022] Open
Abstract
The objective of the present study was to investigate the mechanical indices of hoof horn and their association with length measurements and lesion score. The feet of 185 culled sows from three Greek farms (A: 57 sows; B: 64 sows; C: 64 sows) were used. A slice from the dorsal wall of each claw was used to assess by a three-point bending test the Young’s modulus, yield stress and aximum stress values. The available data from a companion study (part 1) on the length measurements and lesion scores of the claws were used to reveal possible relationships. The Young’s modulus values were significantly higher (p < 0.001 or p < 0.01 depending on location of claw) in the sows of farm C compared to those in sows of farms A and B and in sows of farm B compared to those in the sows of farm A. Yield and maximum stress values were significantly higher (p < 0.05 or p < 0.001 depending on the location of the claw) in the sows of farm C compared to those in the sows of farm A and in the sows of farm B compared to those in the sows of farm A. An increase in heel-sole length decreased all mechanical indices. Young’s modulus and yield stress were associated with wall lesion severity while maximum stress with wall and heel lesion severity. Overall, we conclude that mechanical efficiency deteriorates as length and lesion score increases.
Collapse
|
36
|
Ez-zaki H, Marangu JM, Bellotto M, Dalconi MC, Artioli G, Valentini L. A Fresh View on Limestone Calcined Clay Cement (LC 3) Pastes. Materials (Basel) 2021; 14:ma14113037. [PMID: 34204883 PMCID: PMC8199791 DOI: 10.3390/ma14113037] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/25/2021] [Accepted: 05/30/2021] [Indexed: 11/16/2022]
Abstract
In this work, the factors controlling the fresh state properties of limestone calcined clay cement (LC3) are assessed and compared to Portland and binary cements, extending the scope of previous research by combining rheological measurements with setting time determination and the evaluation of plastic shrinkage by a novel method. Yield stress and elastic modulus are considered indicators for the structural build-up/breakdown process when stress is applied to the system. On the other hand, plastic shrinkage occurs from the mixing to the setting of fresh paste and plays an important role in governing microstructural changes due to settlement and evaporation. Evaluation of the rheological properties with time was appropriate to give an overview of the influence and behavior of different added materials. The elastic modulus of all binders (clinker, LC3, clinker-limestone, and clinker-calcined clay) was increased from mixing to 60 min of curing as follows: 5.27 × 103 to 9.50 × 105 Pa, 5.94 × 103 to 9.87 × 105 Pa, 6.89 × 103 to 5.62 × 105 Pa and 7.85 × 103 to 1.27 × 106 Pa, respectively. Moreover, during the first three hours of curing, LC3 exhibited a reduction of plastic shrinkage by more than a factor of 2 compared to clinker cement. The use of calcined clay with clinker increases the elastic modulus of the system due to the flocculation effect and increased water absorption, while a dilution effect is contributed due to deflocculation and a free-water increase in the system when a high fraction of limestone is present in the binary cement. The combination of limestone and calcined clay with clinker can induce additional chemical reactions, which control the early age properties, such as plastic shrinkage. The obtained results can contribute to optimizing the fresh state properties of ternary blends of OPC, calcined clay, and limestone through a knowledge-based approach.
Collapse
Affiliation(s)
- Hassan Ez-zaki
- CIRCe, Department of Geosciences, University of Padova, Via G. Gradenigo 6, 35131 Padova, Italy; (M.C.D.); (G.A.); (L.V.)
- Correspondence:
| | - Joseph Mwiti Marangu
- Department of Physical Sciences, Meru University of Science & Technology, Meru P.O. Box 972-60200, Kenya;
| | | | - Maria Chiara Dalconi
- CIRCe, Department of Geosciences, University of Padova, Via G. Gradenigo 6, 35131 Padova, Italy; (M.C.D.); (G.A.); (L.V.)
| | - Gilberto Artioli
- CIRCe, Department of Geosciences, University of Padova, Via G. Gradenigo 6, 35131 Padova, Italy; (M.C.D.); (G.A.); (L.V.)
| | - Luca Valentini
- CIRCe, Department of Geosciences, University of Padova, Via G. Gradenigo 6, 35131 Padova, Italy; (M.C.D.); (G.A.); (L.V.)
| |
Collapse
|
37
|
Migliozzi S, Angeli P, Mazzei L. Effect of D-Mannitol on the Microstructure and Rheology of Non-Aqueous Carbopol Microgels. Materials (Basel) 2021; 14:1782. [PMID: 33916550 DOI: 10.3390/ma14071782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 11/17/2022]
Abstract
D-mannitol is a common polyol that is used as additive in pharmaceutical and personal care product formulations. We investigated its effect on the microstructure and rheology of novel non-aqueous Carbopol dispersions employing traditional and time-resolved rheological analysis. We considered two types of sample, (i) fresh (i.e., mannitol completely dissolved in solution) and aged (i.e., visible in crystalline form). The analysis of the intracycle rheological transitions that were observed for different samples revealed that, when completely dissolved in solution, mannitol does not alter the rheological behaviour of the Carbopol dispersions. This highlights that the chemical similarity of the additive with the molecules of the surrounding solvent allows preserving the swollen dimension and interparticle interactions of the Carbopol molecules. Conversely, when crystals are present, a hierarchical structure forms, consisting of a small dispersed phase (Carbopol) agglomerated around a big dispersed phase (crystals). In keeping with this microstructural picture, as the concentration of Carbopol reduces, the local dynamics of the crystals gradually start to control the integrity of the microstructure. Rheologically, this results in a higher elasticity of the suspensions at infinitesimal deformations, but a fragile yielding process at intermediate strains.
Collapse
|
38
|
Shelukhin V. Rotational Particle Separation in Solutions: Micropolar Fluid Theory Approach. Polymers (Basel) 2021; 13:polym13071072. [PMID: 33805358 PMCID: PMC8037239 DOI: 10.3390/polym13071072] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/15/2021] [Accepted: 03/24/2021] [Indexed: 11/16/2022] Open
Abstract
We develop a new mathematical model for rotational sedimentation of particles for steady flows of a viscoplastic granular fluid in a concentric-cylinder Couette geometry when rotation of the Couette cell inner cylinder is prescribed. We treat the suspension as a micro-polar fluid. The model is validated by comparison with known data of measurement. Within the proposed theory, we prove that sedimentation occurs due to particles' rotation and rotational diffusion.
Collapse
Affiliation(s)
- Vladimir Shelukhin
- Lavrentyev Institute of Hydrodynamics, 630090 Novosibirsk, Russia;
- Novosibirsk State University, 630090 Novosibirsk, Russia
| |
Collapse
|
39
|
Li M, Han J, Zhou Y, Yan P. A Rheological Model for Evaluating the Behavior of Shear Thickening of Highly Flowable Mortar. Molecules 2021; 26:1011. [PMID: 33672935 DOI: 10.3390/molecules26041011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/07/2021] [Accepted: 02/12/2021] [Indexed: 11/16/2022] Open
Abstract
Neither the modified Bingham model nor the Herschel–Bulkley model can be used to characterize and calculate the performance of shear thickening of highly flowable mortar because of their incalculability of the rheological parameters. A new exponential rheological model was established to solve the characterization and calculation of shear thickening of the lubrication layer (highly flowable mortar) during the pumping of concrete in this paper. This new exponential rheological model has three rheological parameters, namely, yield stress, consistency coefficient, and consistency exponent. They can quantitatively describe the yield stress, differential viscosity, and shear thickening degree of highly flowable mortar. The calculating results of the rheological parameters of the newly established model for the mortars with different compositions showed that the consistency exponent of mortar decreased with the increase of its sand-binder ratio or the dosage of fly ash in the binder. This indicates that the shear thickening degree of mortar decreases. The consistency exponent of mortar initially decreases and subsequently increases with the increase in silica fume content or the dosage of the superplasticizer. It illustrates that the degree of the shear thickening of mortar initially decreased and subsequently increased. These varying patterns were confirmed by the rheological experiment of mortars.
Collapse
|
40
|
Yasuda T, Shimokasa K. A proposed method of evaluating the yield stress of a thickened liquid using a simplified inclined plane test. J Texture Stud 2021; 53:307-314. [PMID: 33580713 DOI: 10.1111/jtxs.12590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 01/27/2021] [Accepted: 02/01/2021] [Indexed: 11/30/2022]
Abstract
Managing the thickening index of food is important for dysphagia and helps in recognizing the static and dynamic rheological properties of the thickening agent. One dynamic property is the viscosity under a shear rate of 50 s-1 , and one static property is the yield stress at a shear rate of 0 s-1 . The purpose of this study is to design a simplified inclined plane test to identify the yield stress of a thickened liquid by observing flow behavior on an inclined plate. The yield angle (stress) is defined as the inclination angle of the plate just before the thickened liquid flows. The concentrations (yield stresses, yield angles) of a thickening agent containing xanthan gum are 1.0 (1.2, 3°), 1.5 (5.6, 13°), 2.0 (7.5, 26°), 2.5 (12.5, 26°), and 3.0 (19.1, 42°) wt% (Pa, degrees). We measured the time course of the displacement of the downstream edge (DDE) of the thickened liquid on the inclined plate. The discrete inclination angles were in the range of 0° to 42°. The DDE after 10 s was more than 4.5 mm for all concentrations of the thickening agent at an inclination greater than the yield angle of the plate. We confirmed that the yield angle identifies the yield stress for the thickened liquid via the DDE using the simplified inclined plane test with discrete inclination angles.
Collapse
Affiliation(s)
- Toshitaka Yasuda
- Department of Electronic Engineering, Tokyo National College of Technology, Tokyo, Japan
| | - Kenji Shimokasa
- Course of System Engineering, Division of Industrial Technology, Tsukuba University of Technology, Ibaraki, Japan
| |
Collapse
|
41
|
Abstract
BACKGROUND Foam sclerotherapy is the process of using an aqueous foam to deliver surfactant to a varicose vein to damage vein wall endothelial cells, causing the vein to spasm, collapse and ultimately be re-absorbed into the body. Aqueous foams are complex fluids that can exhibit a significant yield stress and high effective viscosity which depend on their composition, particularly the bubble size and liquid fraction. OBJECTIVE To characterise the properties of foams used for varicose vein sclerotherapy and determine their effectiveness in the displacement of blood during sclerotherapy. METHODS Foams are modelled as yield stress fluids and their flow profiles in a model vein are predicted. Values of the yield stress are determined from experimental data for three different foams using the Sauter mean of the bubble size distribution. Along with the measured liquid fraction of the foams, this information is collected into a Bingham number which entirely characterises the process of sclerotherapy. RESULTS Polydispersity in bubble size has a strong effect on the yield stress of a foam and the Sauter mean of the size distribution better captures the effects of a few large bubbles. Reducing the polydispersity increases the yield stress, and a higher yield stress results in a larger plug region moving along the vein, which is more effective in displacing blood. The width of the plug region is proportional to the Bingham number, which also has a quadratic dependence on the liquid fraction of the foam. Assuming typical values for the rate of injection of a foam, we predict that for a vein of diameter 5 mm, the most effective foams have low liquid fraction, a narrow size distribution, and a Bingham number B ≈ 4.5. CONCLUSIONS The Sauter mean radius provides the most appropriate measure of the bubble size for sclerotherapy and the Bingham number then provides a simple measure of the efficacy of foam sclerotherapy in a vein of a given size, and explains the ability of different foams to remove varicose veins. Foams containing small bubbles, with a narrow size distribution, and a low liquid fraction are beneficial for sclerotherapy.
Collapse
Affiliation(s)
- T G Roberts
- Department of Mathematics, Aberystwyth University, UK
| | - S J Cox
- Department of Mathematics, Aberystwyth University, UK
| | - A L Lewis
- Biocompatibles UK Ltd, a Boston Scientific Company, Lakeview, Camberley, Surrey, UK
| | - S A Jones
- Biocompatibles UK Ltd, a Boston Scientific Company, Lakeview, Camberley, Surrey, UK
| |
Collapse
|
42
|
Pierre A, Weger D, Perrot A, Lowke D. Additive Manufacturing of Cementitious Materials by Selective Paste Intrusion: Numerical Modeling of the Flow Using a 2D Axisymmetric Phase Field Method. Materials (Basel) 2020; 13:ma13215024. [PMID: 33171778 PMCID: PMC7664651 DOI: 10.3390/ma13215024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/02/2020] [Accepted: 11/05/2020] [Indexed: 11/16/2022]
Abstract
The 3D printing of concrete has now entered a new era and a transformation of the construction sector is expected to reshape fabrication with concrete. This work focuses on the selective paste intrusion method, which consists of bonding dry particles of aggregate with a cement paste. This innovative technique could lead to the production of very precise component for specific applications. The main obstacle to tackle in order to reach a high shape accuracy of high mechanical performances of 3D printing elements by selectively activating the material is the control of the distribution of the cement paste through the particle bed. With the aim to better understand the path followed by the solution as it penetrates a cut-section of the granular packing, two-dimensional numerical modeling is carried out using Comsol software. A phase-field method combined with a continuous visco-plastic model has been used to study the influence of the average grain diameter, the contact angle, and the rheological properties of cement pastes on the penetration depth. We compare the numerical modeling results to existing experimental results from 3D experiments and a one-dimensional analytical model. We then highlight that the proposed numerical approach is reliable to predict the final penetration of the cement pastes.
Collapse
Affiliation(s)
- Alexandre Pierre
- L2MGC EA4114, CY Cergy Paris University, 5 mail Gay-Lussac—Neuville-sur-Oise, 95031 Cergy-Pontoise, France;
| | - Daniel Weger
- Centre for Building Materials (CBM), Technical University of Munich, Baumbachstraße 7, 81245 Munich, Germany;
| | - Arnaud Perrot
- IRDL, UMR CNRS 6027, Université Bretagne Sud, F-56100 Lorient, France
- Correspondence: ; Tel.: +33-(0)1-34-25-69-36
| | - Dirk Lowke
- Institute of Building Materials, Concrete Construction and Fire Safety (iBMB), University of Braunschweig, Beethovenstr. 52, 38106 Braunschweig, Germany;
| |
Collapse
|
43
|
Malouh MA, Cichero JAY, Manrique YJ, Crino L, Lau ETL, Nissen LM, Steadman KJ. Are Medication Swallowing Lubricants Suitable for Use in Dysphagia? Consistency, Viscosity, Texture, and Application of the International Dysphagia Diet Standardization Initiative (IDDSI) Framework. Pharmaceutics 2020; 12:E924. [PMID: 32998301 DOI: 10.3390/pharmaceutics12100924] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/23/2020] [Accepted: 09/27/2020] [Indexed: 12/03/2022] Open
Abstract
Medication lubricants are thick liquids or gels that are designed to aid swallowing of solid oral dosage forms. Tablets and capsules are placed within a spoonful of the product for swallowing. The aim of this study was to describe and compare commercially available medication lubricants in terms of textural suitability for patients with dysphagia. Twelve medication lubricants were characterised according to the International Dysphagia Diet Standardisation Initiative (IDDSI) framework. Apparent viscosity, yield stress, thickness consistency, and various texture features were compared. Gloup Forte was the only medication lubricant classified as IDDSI level 4 (pureed/extremely thick) at room (24 °C) temperature. Four other Gloup products were IDDSI level 3 (liquidised/moderately thick) at room temperature but testing at 4 °C or pouring from the container instead of using the pump dispenser resulted in classification as IDDSI level 4. The IDDSI Flow test would have classified MediSpend and Slo Tablets as IDDSI level 3, but their very low yield stress led to these fluids flowing too quickly through the prongs of a fork and so these were classified as <3. Severo was IDDSI level 2. Heyaxon and the two versions of Magic Jelly tested contained lumps, and Swallow Aid had exceptionally high viscosity, hardness, adhesiveness, and gumminess, classifying them as IDDSI Level 7 (“regular textures”) and therefore as unsuitable for people with dysphagia according to IDDSI. This study provides valuable information to help with the selection of a safe medication lubricant with appropriate thickness level suited to each individual with dysphagia.
Collapse
|
44
|
Donley GJ, Singh PK, Shetty A, Rogers SA. Elucidating the G″ overshoot in soft materials with a yield transition via a time-resolved experimental strain decomposition. Proc Natl Acad Sci U S A 2020; 117:21945-52. [PMID: 32839307 DOI: 10.1073/pnas.2003869117] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Materials that exhibit yielding behavior are used in many applications, from spreadable foods and cosmetics to direct write three-dimensional printing inks and filled rubbers. Their key design feature is the ability to transition behaviorally from solid to fluid under sufficient load or deformation. Despite its widespread applications, little is known about the dynamics of yielding in real processes, as the nonequilibrium nature of the transition impedes understanding. We demonstrate an iteratively punctuated rheological protocol that combines strain-controlled oscillatory shear with stress-controlled recovery tests. This technique provides an experimental decomposition of recoverable and unrecoverable strains, allowing for solid-like and fluid-like contributions to a yield stress material's behavior to be separated in a time-resolved manner. Using this protocol, we investigate the overshoot in loss modulus seen in materials that yield. We show that this phenomenon is caused by the transition from primarily solid-like, viscoelastic dissipation in the linear regime to primarily fluid-like, plastic flow at larger amplitudes. We compare and contrast this with a viscoelastic liquid with no yielding behavior, where the contribution to energy dissipation from viscous flow dominates over the entire range of amplitudes tested.
Collapse
|
45
|
van der Zwan T, Sigg A, Hu J, Chandra RP, Saddler JN. Enzyme-Mediated Lignocellulose Liquefaction Is Highly Substrate-Specific and Influenced by the Substrate Concentration or Rheological Regime. Front Bioeng Biotechnol 2020; 8:917. [PMID: 32850753 PMCID: PMC7423843 DOI: 10.3389/fbioe.2020.00917] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 07/16/2020] [Indexed: 01/30/2023] Open
Abstract
The high viscosities/yield stresses of lignocellulose slurries makes their industrial processing a significant challenge. However, little is known regarding the degree to which liquefaction and its enzymatic requirements are specific to a substrate's physicochemical and rheological properties. In the work reported here, the substrate- and rheological regime-specificities of liquefaction of various substrates were assessed using real-time in-rheometer viscometry and offline oscillatory rheometry when hydrolyzed by combinations of cellobiohydrolase (Trichoderma reesei Cel7A), endoglucanase (Humicola insolens Cel45A), glycoside hydrolase (GH) family 10 xylanase, and GH family 11 xylanase. In contrast to previous work that has suggested that endoglucanase activity dominates enzymatic liquefaction, all of the enzymes were shown to have at least some liquefaction capacity depending on the substrate and reaction conditions. The contribution of individual enzymes was found to be influenced by the rheological regime; in the concentrated regime, the cellobiohydrolase outperformed the endoglucanase, achieving 2.4-fold higher yield stress reduction over the same timeframe, whereas the endoglucanase performed best in the semi-dilute regime. It was apparent that the significant differences in rheology and liquefaction mechanisms made it difficult to predict the liquefaction capacity of an enzyme or enzyme cocktail at different substrate concentrations.
Collapse
Affiliation(s)
- Timo van der Zwan
- Forest Products Biotechnology and Bioenergy Group, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, BC, Canada
| | - Alexander Sigg
- Forest Products Biotechnology and Bioenergy Group, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, BC, Canada
- Department of Chemistry, Technical University of Munich, Munich, Germany
| | - Jinguang Hu
- Forest Products Biotechnology and Bioenergy Group, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, BC, Canada
| | - Richard P. Chandra
- Forest Products Biotechnology and Bioenergy Group, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, BC, Canada
| | - Jack N. Saddler
- Forest Products Biotechnology and Bioenergy Group, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
46
|
Xu Z, Miao Y, Wu H, Yuan X, Liu C. Estimation of Viscosity and Yield Stress of Cement Grouts at True Ground Temperatures Based on the Flow Spread Test. Materials (Basel) 2020; 13:ma13132939. [PMID: 32630088 PMCID: PMC7372412 DOI: 10.3390/ma13132939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/21/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
The rheology of cement grouts often plays a crucial role in the success of rock grouting. In practice, the rheological parameters should be timely adjusted according to the evolution of grouting pressure, flow rate and injection time. However, obtaining the magnitude of rheological parameters is not easy to achieve under site conditions. More importantly, the ground temperature in deep rock masses is elevated higher than that on the surface or under room conditions, which has been demonstrated to strongly influence the rheological properties of grouts. Reasonable understanding and control of the rheological behavior of cement grouts at true ground temperatures is very important to the quality of grouting. This paper aims to propose a simplified method to approximately estimate the initial yield stress and viscosity of cement grouts for rock grouting under elevated ground temperature that actually exists in deep rock masses, on the basis of the flow spread test. The temperature investigated was controlled between 12 °C and 45 °C to simulate the true ground temperature in rock masses with a maximum depth of 1500 m below the surface. Taking the influences of elevated temperatures into account, a temperature-based model for estimating the initial viscosity of cement grout was successfully developed on the basis of Liu's model and the results of the flow spread test. However, the yield stress failed to be estimated by the Lapasin model due to the absence of plastic behavior of cement grouts. In contrast, yield stress can be linearly correlated to the measured relative flow area. In this work, it was also found that the dependence of yield stress of cement grouts on relative flow area is a strongly exponential law. The temperature dependence of the viscosity of water was accounted for in both estimations of viscosity and yield stress of grouts. Significantly, it was found that the packing density of cement is dependent on the grout temperature, especially when the temperature is up to 45 °C. The proposed method in this work offers an alternative solution for technicians to reasonably control the rheological properties in the increasing applications of deep rock grouting.
Collapse
Affiliation(s)
- Zhipeng Xu
- College of Water Resource and Hydropower, Sichuan University, Chengdu 610065, China;
- State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
| | - Yichen Miao
- Institute for Disaster Management and Reconstruction, Sichuan University-The Hong Kong Polytechnic University, Chengdu 610207, China; (Y.M.); (X.Y.)
| | - Haikuan Wu
- College of Water Resource and Hydropower, Sichuan University, Chengdu 610065, China;
- State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
| | - Xun Yuan
- Institute for Disaster Management and Reconstruction, Sichuan University-The Hong Kong Polytechnic University, Chengdu 610207, China; (Y.M.); (X.Y.)
| | - Changwu Liu
- College of Water Resource and Hydropower, Sichuan University, Chengdu 610065, China;
- State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
| |
Collapse
|
47
|
Zhang Y, Hu M, Zhou Y. An Experimental Study on Bubble Growth in Laponite RD as Thixotropic Yield Material. Materials (Basel) 2020; 13:ma13132887. [PMID: 32605053 PMCID: PMC7372451 DOI: 10.3390/ma13132887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
The growth and release of the leading major bubble at the tip of a needle in the thixotropic yield material Laponite RD was different from subsequent minor bubbles. The gas injection experiments combined with high-speed camera were conducted. The results showed that the shape of the major bubbles transformed from an inverted carrot shape to an inverted teardrop shape, while the shape of the minor bubbles tended to be elliptical. In addition, the pressure of bubble emergence consisted of hydrostatic pressure, capillary pressure, and cracking pressure. The major and minor bubbles differed only in the cracking pressure. The pressure when the minor bubble detached could be estimated from the lateral hydrostatic pressure. It can be deduced from dimensionless numbers that buoyancy and viscous forces were, respectively, the main driving force and resistance of bubble growth. The yield stress of Laponite RD and inertial force at the initial moment resulted in distinctive behavior of the major bubble. In addition to the viscosity resistance, surface tension, and hydrostatic pressure had a non-negligible influence on minor bubbles and still accounted for 10-20% of the total resistance in the later stage but less than 5% in major bubble growth.
Collapse
|
48
|
Gülçimen Çakan B, Hähner P, Soyarslan C, Bargmann S. An Enhanced Method to Evaluate Tensile Yield Stress by Small Punch Tests Using Deflection Curves. Materials (Basel) 2020; 13:E2840. [PMID: 32599949 PMCID: PMC7345068 DOI: 10.3390/ma13122840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/21/2020] [Accepted: 06/22/2020] [Indexed: 11/17/2022]
Abstract
While force-displacement curves are often preferred in Small Punch (SP) tests due to the ease of the experimental set-up, they encompass significant uncertainties arising from frame compliance. In this work, a methodology is presented to predict yield stresses from the force vs. deflection curves. The present method relies on determining different force levels from the initial part of the force-deflection curve to reflect both the slope and the curvature instead of using a single force level only. The predicted yield stresses for different types of materials, that is, low- and high-strength alloys, are found to be in good agreement with the actual proof stresses with a maximum error of 16%.
Collapse
Affiliation(s)
- Betül Gülçimen Çakan
- Department of Mechanical Engineering, Bursa Uludağ University, Görükle, 16059 Bursa, Turkey;
| | - Peter Hähner
- Nuclear Safety and Security Directorate, Joint Research Centre, European Commission, NL-1755 LE Petten, The Netherlands
| | - Celal Soyarslan
- School of Mechanical Engineering and Safety Engineering, University of Wuppertal, 42119 Wuppertal, Germany; (C.S.); (S.B.)
| | - Swantje Bargmann
- School of Mechanical Engineering and Safety Engineering, University of Wuppertal, 42119 Wuppertal, Germany; (C.S.); (S.B.)
| |
Collapse
|
49
|
Ukrainczyk N, Thiedeitz M, Kränkel T, Koenders E, Gehlen C. Modeling SAOS Yield Stress of Cement Suspensions: Microstructure-Based Computational Approach. Materials (Basel) 2020; 13:E2769. [PMID: 32570873 DOI: 10.3390/ma13122769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/29/2020] [Accepted: 06/16/2020] [Indexed: 11/17/2022]
Abstract
Two static yield stress models, one known as YODEL and the newly proposed BreakPro, based on inter-particle bond breaking probability, were employed to comparatively simulate the yield stress of cement suspensions, induced by oscillatory rheological tests with small amplitude oscillatory shear (SAOS). This yield stress occurs at a critical strain in the order of 0.01%, and is commonly attributed to the limit of the linear viscoelastic domain, where attractive forces bridge the cement particles and form a flocculated particle network. YODEL is based on van der Waals (vdW) interaction forces to describe the yield stress for flow onset at a critical strain of a few percent, developed for simple non-reactive particulate suspensions. However, due to the high pH and reactivity of cementitious suspensions, their particle interaction forces are much higher than vdW. Therefore, until now, the YODEL adaptations to cementitious suspensions did not explicitly consider the microstructural-based salient feature of the original model, but used it as an implicit fitting parameter to scale the average attractive force. In this paper, the force is inversely estimated using the full power of the two microstructural-based models, presenting a new mathematical tool for investigating the fragility of the rigid percolated structure of cement suspensions. The model parameters were calibrated on measured yield stresses obtained by SAOS measurements in a high-sensitivity rheometer. The estimated forces were found to be 5.57 (BreakPro) and 1.43 (YODEL) times higher than typical van der Waals forces. The YODEL percolation threshold of 21% turned out to be significantly lower than the one found by the BreakPro model (37%). This indicated that BreakPro modeling assumptions are better suited for the description of yield stress at SAOS critical strain than the YODEL model.
Collapse
|
50
|
Varchanis S, Haward SJ, Hopkins CC, Syrakos A, Shen AQ, Dimakopoulos Y, Tsamopoulos J. Transition between solid and liquid state of yield-stress fluids under purely extensional deformations. Proc Natl Acad Sci U S A 2020; 117:12611-7. [PMID: 32434919 DOI: 10.1073/pnas.1922242117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The stress-induced transition from solid to liquid state is commonly referred to as “yielding.” Yield-stress materials, including pastes, muds, blood, crude oil, and condiments like mayonnaise, have solid-like properties at rest but can be made to yield and flow under sufficient applied stress. Despite their ubiquity and importance, the existing 100-y-old theory describing the behavior of such materials is only well verified under basic conditions of applied shear stress and assumes that the solid state is undeformable. Experiments and simulations conducted under pure extension provide fundamental information on the behavior of yield-stress materials and demand an overhaul of the current standard theory in order to account for material deformation in the solid-like state prior to yielding and flow. We report experimental microfluidic measurements and theoretical modeling of elastoviscoplastic materials under steady, planar elongation. Employing a theory that allows the solid state to deform, we predict the yielding and flow dynamics of such complex materials in pure extensional flows. We find a significant deviation of the ratio of the elongational to the shear yield stress from the standard value predicted by ideal viscoplastic theory, which is attributed to the normal stresses that develop in the solid state prior to yielding. Our results show that the yield strain of the material governs the transition dynamics from the solid state to the liquid state. Finally, given the difficulties of quantifying the stress field in such materials under elongational flow conditions, we identify a simple scaling law that enables the determination of the elongational yield stress from experimentally measured velocity fields.
Collapse
|