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Quinn JA, Davidson JR, Bajpai A, Ó Brádaigh CM, McCarthy ED. Advanced Ultrasonic Inspection of Thick-Section Composite Structures for In-Field Asset Maintenance. Polymers (Basel) 2023; 15:3175. [PMID: 37571072 PMCID: PMC10421391 DOI: 10.3390/polym15153175] [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: 06/18/2023] [Revised: 07/19/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023] Open
Abstract
An investigation into the inspection capabilities of in-field advanced ultrasound detection for use on ultra-thick (20 to 100 mm) glass fibre-reinforced polyester composites is presented. Plates were manufactured using custom moulding techniques, such that delamination flaws were created at calibrated depths. The full matrix capture technique with an on-board total focussing method was used to detect flaws scanned by a 0.5 MHz linear array probe. Flaw through-thickness dimensions were altered to assess the threshold for crack face separation at which delaminations could be identified. Furthermore, part thickness and in-plane flaw dimensions were varied to identify the inspection capability limitations of advanced ultrasonics for thick composites. The results presented in this study demonstrate an inverse relationship between the ability to find delaminations and plate thicknesses, with inspections successful at depths up to 74 mm. When the delamination thickness exhibited surface-to-surface contact, the inspection capability was reduced to 35 mm. There was an exponential decay relationship between the accuracy of the flaw depth measurement and plate thickness, likely due to the necessity of low probe frequencies. The effective inspection depth was determined to be in the range of 1 to 20 times the wavelength. It is speculated that the accuracy of measurements could be improved using probes with novel coupling solutions, and detectors with optimised signal processing/filtration algorithms.
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Affiliation(s)
- James A. Quinn
- School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Edinburgh EH9 3FB, UK; (J.R.D.); (A.B.); (C.M.Ó.B.); (E.D.M.)
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Pappa EJ, Quinn JA, Murray JJ, Davidson JR, Ó Brádaigh CM, McCarthy ED. Experimental Study on the Interlaminar Fracture Properties of Carbon Fibre Reinforced Polymer Composites with a Single Embedded Toughened Film. Polymers (Basel) 2021; 13:polym13234103. [PMID: 34883607 PMCID: PMC8659136 DOI: 10.3390/polym13234103] [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: 11/01/2021] [Revised: 11/14/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022] Open
Abstract
In this study, two types of single polymer films have been inserted in a composite laminate to examine their toughening effects on mechanical properties. The first is a thermoplastic polyurethane (PU) film, and the second is an adhesive epoxy film featuring a polyester net. The laminates were manufactured either using a co-curing (CC) process or a secondary bonding (SB) process used for the epoxy film. Mode I and mode II interlaminar fracture toughness were measured for laminates manufactured by both processes and compared with the corresponding reference laminate toughness. A significant increase in both mode I and mode II toughness resulted when introducing a single PU film, approximately 290% and 50%, respectively. Similarly, the epoxy film improved the interlaminar fracture properties; the CC process produced an increase of 175% for mode II toughness, while the SB adhesive film showed an increase of 75% for mode II toughness.
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Zhou T, McCarthy ED, Soutis C, Cartmell SH. Novel lactone‐layered double hydroxide ionomer powders for bone tissue repair. J Biomed Mater Res B Appl Biomater 2020; 108:2835-2846. [DOI: 10.1002/jbm.b.34614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 03/07/2020] [Accepted: 03/19/2020] [Indexed: 01/10/2023]
Affiliation(s)
- Tianhao Zhou
- School of Materials The University of Manchester Manchester UK
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Chung M, Radacsi N, Robert C, McCarthy ED, Callanan A, Conlisk N, Hoskins PR, Koutsos V. On the optimization of low-cost FDM 3D printers for accurate replication of patient-specific abdominal aortic aneurysm geometry. 3D Print Med 2018; 4:2. [PMID: 29782613 PMCID: PMC5954792 DOI: 10.1186/s41205-017-0023-2] [Citation(s) in RCA: 30] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/26/2017] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND There is a potential for direct model manufacturing of abdominal aortic aneurysm (AAA) using 3D printing technique for generating flexible semi-transparent prototypes. A patient-specific AAA model was manufactured using fused deposition modelling (FDM) 3D printing technology. A flexible, semi-transparent thermoplastic polyurethane (TPU), called Cheetah Water (produced by Ninjatek, USA), was used as the flexible, transparent material for model manufacture with a hydrophilic support structure 3D printed with polyvinyl alcohol (PVA). Printing parameters were investigated to evaluate their effect on 3D-printing precision and transparency of the final model. ISO standard tear resistance tests were carried out on Ninjatek Cheetah specimens for a comparison of tear strength with silicone rubbers. RESULTS It was found that an increase in printing speed decreased printing accuracy, whilst using an infill percentage of 100% and printing nozzle temperature of 255 °C produced the most transparent results. The model had fair transparency, allowing external inspection of model inserts such as stent grafts, and good flexibility with an overall discrepancy between CAD and physical model average wall thicknesses of 0.05 mm (2.5% thicker than the CAD model). The tear resistance test found Ninjatek Cheetah TPU to have an average tear resistance of 83 kN/m, higher than any of the silicone rubbers used in previous AAA model manufacture. The model had lower cost (4.50 GBP per model), shorter manufacturing time (25 h 3 min) and an acceptable level of accuracy (2.61% error) compared to other methods. CONCLUSIONS It was concluded that the model would be of use in endovascular aneurysm repair planning and education, particularly for practicing placement of hooked or barbed stents, due to the model's balance of flexibility, transparency, robustness and cost-effectiveness.
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Affiliation(s)
- Michael Chung
- The School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Robert Stevenson Road, Edinburgh, EH9 3FB UK
| | - Norbert Radacsi
- The School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Robert Stevenson Road, Edinburgh, EH9 3FB UK
| | - Colin Robert
- The School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Robert Stevenson Road, Edinburgh, EH9 3FB UK
| | - Edward D. McCarthy
- The School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Robert Stevenson Road, Edinburgh, EH9 3FB UK
| | - Anthony Callanan
- The School of Engineering, Institute for Bioengineering, The University of Edinburgh, Max Born Crescent, Edinburgh, EH9 3FB UK
| | - Noel Conlisk
- The School of Engineering, Institute for Bioengineering, The University of Edinburgh, Max Born Crescent, Edinburgh, EH9 3FB UK
- Centre for Cardiovascular Sciences, The University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ UK
| | - Peter R. Hoskins
- The School of Engineering, Institute for Bioengineering, The University of Edinburgh, Max Born Crescent, Edinburgh, EH9 3FB UK
- Centre for Cardiovascular Sciences, The University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ UK
| | - Vasileios Koutsos
- The School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Robert Stevenson Road, Edinburgh, EH9 3FB UK
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Fox DM, Novy M, Brown K, Zammarano M, Harris RH, Murariu M, McCarthy ED, Seppala JE, Gilman JW. Flame retarded poly(lactic acid) using POSS-modified cellulose. 2. Effects of intumescing flame retardant formulations on polymer degradation and composite physical properties. Polym Degrad Stab 2014. [DOI: 10.1016/j.polymdegradstab.2014.01.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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McCarthy ED, Zammarano M, Fox DM, Nieuwendaal RC, Kim YS, Maupin PH, Trulove PC, Gilman JW. Formation of extended ionomeric network by bulk polymerization of l,d-lactide with layered-double-hydroxide. POLYMER 2013. [DOI: 10.1016/j.polymer.2012.11.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zammarano M, Maupin PH, Sung LP, Gilman JW, McCarthy ED, Kim YS, Fox DM. Revealing the interface in polymer nanocomposites. ACS Nano 2011; 5:3391-3399. [PMID: 21410222 DOI: 10.1021/nn102951n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The morphological characterization of polymer nanocomposites over multiple length scales is a fundamental challenge. Here, we report a technique for high-throughput monitoring of interface and dispersion in polymer nanocomposites based on Förster resonance energy transfer (FRET). Nanofibrillated cellulose (NFC), fluorescently labeled with 5-(4,6-dichlorotriazinyl)-aminofluorescein (FL) and dispersed into polyethylene (PE) doped with Coumarin 30 (C30), is used as a model system to assess the ability of FRET to evaluate the effect of processing on NFC dispersion in PE. The level of energy transfer and its standard deviation, measured by fluorescence spectroscopy and laser scanning confocal microscopy (LSCM), are exploited to monitor the extent of interface formation and composite homogeneity, respectively. FRET algorithms are used to generate color-coded images for a real-space observation of energy transfer efficiency. These images reveal interface formation at a nanoscale while probing a macroscale area that is large enough to be representative of the entire sample. The unique ability of this technique to simultaneously provide orientation/spatial information at a macroscale and nanoscale features, encoded in the FRET signal, provides a new powerful tool for structure-property-processing investigation in polymer nanocomposites.
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Affiliation(s)
- Mauro Zammarano
- Department of Chemistry, American University, Washington, DC 20016, USA.
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Han J, McCarthy ED, Hoeven WV, Calvin M, Bradley WH. Organic geochemical studies, ii. A preliminary report on the distribution of aliphatic hydrocarbons in algae, in bacteria, and in a recent lake sediment. Proc Natl Acad Sci U S A 2010; 59:29-33. [PMID: 16591588 PMCID: PMC285995 DOI: 10.1073/pnas.59.1.29] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- J Han
- DEPARTMENT OF CHEMISTRY, UNIVERSITY OF CALIFORNIA, BERKELEY
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McCarthy ED, Dunk WAE, Boodhoo KVK. Application of an intensified narrow channel reactor to the aqueous phase precipitation of barium sulphate. J Colloid Interface Sci 2007; 305:72-87. [PMID: 17064716 DOI: 10.1016/j.jcis.2006.08.056] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 07/31/2006] [Accepted: 08/22/2006] [Indexed: 11/20/2022]
Abstract
A homogeneous liquid phase reaction between barium chloride (BaCl(2)) and sodium sulphate (Na(2)SO(4)) was conducted in a narrow channel reactor to produce barium sulphate (BaSO(4)) precipitate. The effects of channel dimensions and channel residence times on crystal size, crystal size distribution, nucleation rates, crystal morphology and conversion of reactants were investigated at different levels of reactant supersaturation ratio. Our results indicate that the smallest particle sizes are favoured when supersaturation ratios and channel velocities are high. The minimum average particle diameter observed was approximately 0.2 microm in a channel of hydraulic diameter 0.5 mm and length 20 cm at an initial supersaturation ratio of 4483 (0.1 M), which correspond to conditions giving rise to the highest nucleation rates. It has also been observed that particle size depends on the conversion to product, the smallest particles being formed when conversion lies within the range of 30 to 40%. Conversions in excess of 60% have been reached but there is a detectable limiting effect with increased supersaturation and reduced residence times. Experiments conducted at similar levels of supersaturation under stirred tank conditions showed that particle size was consistently larger and particle size distribution was much broader than that achieved in the narrow channel reactor. Scanning electron microscopy (SEM) images of the crystals formed in the narrow channels show that spherical particles dominate in the smallest channels at high velocities whilst coarse, tabular crystals are obtained in the larger channels. Greater tendency to agglomerate is also observed at high supersaturation ratios, after one minute of reaction.
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Affiliation(s)
- E D McCarthy
- School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
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Langner TS, Gersten JC, McCarthy ED, Eisenberg JG, Greene EL, Herson JH, Jameson JD. A screening inventory for assessing psychiatric impairment in children 6 to 18. J Consult Clin Psychol 1976. [PMID: 1254763 DOI: 10.1037//0022-006x.44.2.286] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Gersten JC, Langner TS, Eisenberg JG, Fagan OS, McCarthy ED. Stability and change in types of behavioral disturbance of children and adolescents. J Abnorm Child Psychol 1976; 4:111-27. [PMID: 1084892 DOI: 10.1007/bf00916516] [Citation(s) in RCA: 90] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Langner TS, Gersten JC, McCarthy ED, Eisenberg JG, Greene EL, Herson JH, Jameson JD. A screening inventory for assessing psychiatric impairment in children 6 to 18. J Consult Clin Psychol 1976; 44:286-96. [PMID: 1254763 DOI: 10.1037/0022-006x.44.2.286] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Langner TS, Gersten JC, Greene EL, Eisenberg JG, Herson JH, McCarthy ED. Treatment of psychological disorders among urban children. J Consult Clin Psychol 1974; 42:170-9. [PMID: 4823552 DOI: 10.1037/h0036249] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Greene EL, Langner TS, Herson JH, Jameson JD, Eisenberg JG, McCarthy ED. Some methods of evaluating behavioral variations in children 6 to 18. J Am Acad Child Psychiatry 1973; 12:531-53. [PMID: 4759033 DOI: 10.1016/s0002-7138(09)61262-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Ilton M, Jevans AW, McCarthy ED, Vance D, White HB, Bloch K. Fatty acid synthetase activity in Mycobacterium phlei: regulation by polysaccharides. Proc Natl Acad Sci U S A 1971; 68:87-91. [PMID: 5276305 PMCID: PMC391108 DOI: 10.1073/pnas.68.1.87] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The multienzyme complex from Mycobacterium phlei which catalyzes the synthesis of long chain fatty acids from acetyl-CoA and malonyl-CoA requires a heat-stable fraction (stimulating factor, SF) for activity. Fractionation of heat-treated M. phlei extracts affords two stimulatory subfractions, one of which (SF(2)) can be replaced by FMN. The other (SF(1)) is further separable into 3 polysaccharides (PS(I), PS(II), and PS(III)). PS(I) contains about 95% 3-O-methylmannose and 5% mannose; the sugar composition of PS(II) and PS(III) is about 55% 6-O-methylglucose and 45% glucose for both. Each of the three purified polysaccharides, in combination with FMN, substitutes for the crude stimulating factor. The polysaccharides exert their effect on the fatty acid synthetase by lowering the K(m) for acetyl-CoA about 50-fold.
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