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Klemenčić M, Bolanča Mirković I, Bolf N, Markić M. Determination of the Mass Fractions of the Heavy Metals in the Recycled Cellulose Pulp. Polymers (Basel) 2024; 16:934. [PMID: 38611192 PMCID: PMC11013302 DOI: 10.3390/polym16070934] [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: 03/01/2024] [Revised: 03/21/2024] [Accepted: 03/24/2024] [Indexed: 04/14/2024] Open
Abstract
In the process of paper recycling, certain amounts of metals can be found in the cellulose suspension, the source of which is mainly printing inks. The paper industry often uses different technologies to reduce heavy metal emissions. The recycling of laminated packaging contributes to the formation of sticky particles, which affects the concentration of heavy metals. This study aimed to determine the mass fraction of metals in the different phases of the deinking process to optimize the cellulose pulp's quality and design healthy correct packaging products. In this research, the deinking flotation of laminated and non-laminated samples was carried out by the Ingede 11 method. As a result of the study, the mass fractions of metals in cellulose pulp were divided into four groups according to the mass fraction's increasing value and the metals' increasing electronegativity. The quantities of metals were analyzed using Inductively Coupled Mass Spectrometry (ICP-MS). The separation of metals from cellulose pulp is influenced by the presence of adhesives and the electronegativity of the metal. The results of the study show that the recycling process removes certain heavy metals very well, which indicates the good recycling potential of pharmaceutical cardboard samples.
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Affiliation(s)
- Mia Klemenčić
- Faculty of Graphic Arts, University of Zagreb, 10 000 Zagreb, Croatia;
| | | | - Nenad Bolf
- Faculty of Chemical Engineering and Technology, University of Zagreb, 10 000 Zagreb, Croatia (M.M.)
| | - Marinko Markić
- Faculty of Chemical Engineering and Technology, University of Zagreb, 10 000 Zagreb, Croatia (M.M.)
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Šitum Ž, Herceg S, Bolf N, Ujević Andrijić Ž. Design, Construction and Control of a Manipulator Driven by Pneumatic Artificial Muscles. Sensors (Basel) 2023; 23:776. [PMID: 36679573 PMCID: PMC9866138 DOI: 10.3390/s23020776] [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] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/02/2023] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
This paper describes the design, construction and experimental testing of a single-joint manipulator arm actuated by pneumatic artificial muscles (PAMs) for the tasks of transporting and sorting work pieces. An antagonistic muscle pair is used in a rotational sense to produce a required torque on a pulley. The concept, operating principle and elementary properties of pneumatic muscle actuators are explained. Different conceptions of the system realizations are analyzed using the morphological-matrix conceptual design framework and top-rated solution was practically realized. A simplified, control-oriented mathematical model of the manipulator arm driven by PAMs and controlled with a proportional control valve is derived. The model is then used for a controller design process. Fluidic muscles have great potential for industrial applications and assembly automation to actuate new types of robots and manipulators. Their characteristics, such as compactness, high strength, high power-to-weight ratio, inherent safety and simplicity, are worthy features for advanced manipulation systems. The experiments were carried out on a practically realized manipulator actuated by a pair of muscle actuators set into an antagonistic configuration. The setup also includes an original solution for the subsystem to add work pieces in the working space of the manipulator.
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Affiliation(s)
- Željko Šitum
- Department of Robotics and Production System Automation, Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, 10000 Zagreb, Croatia
| | - Srečko Herceg
- Department of Measurements and Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, Savska cesta 16/5a, 10000 Zagreb, Croatia
| | - Nenad Bolf
- Department of Measurements and Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, Savska cesta 16/5a, 10000 Zagreb, Croatia
| | - Željka Ujević Andrijić
- Department of Measurements and Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, Savska cesta 16/5a, 10000 Zagreb, Croatia
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Zečević N, Bolf N. Advanced operation and monitoring the economic performance of ammonia production based on natural gas steam reforming by using programmed feedforward–Ratio–Cascade controllers. CHEM ENG COMMUN 2021. [DOI: 10.1080/00986445.2021.1919651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Nenad Zečević
- Measurements and Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, Zagreb, Croatia
| | - Nenad Bolf
- Measurements and Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, Zagreb, Croatia
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Herceg S, Ujević Andrijić Ž, Bolf N. Support Vector Machine-based Soft Sensors in the Isomerisation Process. CHEM BIOCHEM ENG Q 2021. [DOI: 10.15255/cabeq.2020.1825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This paper presents the development of soft sensor empirical models using support<br />
vector machine (SVM) for the continual assessment of 2,3-dimethylbutane and 2-methylpentane mole percentage as important product quality indicators in the refinery isomerisation process. During the model development, critical steps were taken, including selection and pre-processing of the industrial process data, which are broadly discussed in this paper. The SVM model results were compared with dynamic linear output error model and nonlinear Hammerstein-Wiener model. Evaluation of the developed models on independent data sets showed their reliability in the assessment of the component contents. The soft sensors are to be embedded into the process control system, and serve primarily as a replacement during the process analysersb failure and service periods.
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Affiliation(s)
- Srećko Herceg
- Faculty of Chemical Engineering and Technology, University of Zagreb
| | | | - Nenad Bolf
- Faculty of Chemical Engineering and Technology, University of Zagreb, Department of Measurements and Process Control
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Affiliation(s)
- Nenad Zecevic
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulicev trg 19, HR-10000 Zagreb, Croatia
| | - Nenad Bolf
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulicev trg 19, HR-10000 Zagreb, Croatia
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Affiliation(s)
- Ivan Mohler
- Faculty of Chemical Engineering and Technology, University of Zagreb, Zagreb, Croatia
| | | | - Nenad Bolf
- Faculty of Chemical Engineering and Technology, University of Zagreb, Zagreb, Croatia
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Affiliation(s)
- Željka Ujević Andrijić
- Department of Measurements and
Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, Savska c. 16/5A, 10000 Zagreb,
Croatia
| | - Tomislav Rolich
- Department of Fundamental
Natural
and Engineering Sciences, Faculty of Textile Technology, University of Zagreb, Prilaz baruna Filipovića
28a, 10000 Zagreb, Croatia
| | - Nenad Bolf
- Department of Measurements and
Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, Savska c. 16/5A, 10000 Zagreb,
Croatia
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Zelić B, Bolf N, Vasić-Racki D. Modeling of the pyruvate production with Escherichia coli: comparison of mechanistic and neural networks-based models. Bioprocess Biosyst Eng 2006; 29:39-47. [PMID: 16528533 DOI: 10.1007/s00449-006-0054-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Accepted: 02/17/2006] [Indexed: 11/28/2022]
Abstract
Three different models: the unstructured mechanistic black-box model, the input-output neural network-based model and the externally recurrent neural network model were used to describe the pyruvate production process from glucose and acetate using the genetically modified Escherichia coli YYC202 ldhA::Kan strain. The experimental data were used from the recently described batch and fed-batch experiments [ Zelić B, Study of the process development for Escherichia coli-based pyruvate production. PhD Thesis, University of Zagreb, Faculty of Chemical Engineering and Technology, Zagreb, Croatia, July 2003. (In English); Zelić et al. Bioproc Biosyst Eng 26:249-258 (2004); Zelić et al. Eng Life Sci 3:299-305 (2003); Zelić et al Biotechnol Bioeng 85:638-646 (2004)]. The neural networks were built out of the experimental data obtained in the fed-batch pyruvate production experiments with the constant glucose feed rate. The model validation was performed using the experimental results obtained from the batch and fed-batch pyruvate production experiments with the constant acetate feed rate. Dynamics of the substrate and product concentration changes was estimated using two neural network-based models for biomass and pyruvate. It was shown that neural networks could be used for the modeling of complex microbial fermentation processes, even in conditions in which mechanistic unstructured models cannot be applied.
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Affiliation(s)
- B Zelić
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, HR-10000, Zagreb, Croatia.
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McConnell DS, Wang Q, Sluss PM, Bolf N, Khoury RH, Schneyer AL, Midgley AR, Reame NE, Crowley WF, Padmanabhan V. A two-site chemiluminescent assay for activin-free follistatin reveals that most follistatin circulating in men and normal cycling women is in an activin-bound state. J Clin Endocrinol Metab 1998; 83:851-8. [PMID: 9506739 DOI: 10.1210/jcem.83.3.4651] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Follistatin (FS) is a monomeric protein that binds and regulates the bioavailability of activin. Previously, we found circulating levels of total FS to be similar in men and cycling women. Because relative amounts of activin-bound and free FS are important considerations in determining activin bioavailability, we asked here whether the relative proportions of these two changed during different physiologic states. For this, we developed a two-site, solid-phase, immunochemiluminescent assay for free FS. The assay recognizes the 288 or 315 amino acid variants of human FS and has a detectable limit of 1 ng/mL. Inhibin, transforming growth factor-beta, or alpha-2-macroglobulin do not cross-react or interfere in this assay. Preincubation of FS with activin results in dose-dependent loss of immunoreactivity, confirming specificity of the assay for free FS. Human follicular fluid, pituitary extract, and serum with added FS dilute parallel with the recombinant human FS-288 standard. Recovery of recombinant human FS-288 from serum is quantitative. Using this assay, we found circulating concentrations of free FS to be at or below the detection limit of the assay throughout the menstrual cycle. Comparison of circulating total and free FS levels in postmenopausal or cycling women and normal men suggested that at least 90% is activin-bound. In contrast, measurable quantities of free FS were found in follicular fluid and pituitary extracts. The results of this study, showing that most circulating FS is normally activin-bound, argue against an endocrine role for FS and suggest that a major role of circulating FS is to bind and neutralize the bioactivity of circulating activin. The roles of FS as a local autocrine or paracrine regulator of activin in target tissues, where FS exists in free form, or as an endocrine regulator in human pathophysiology, warrants further investigation.
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Affiliation(s)
- D S McConnell
- Department of Pediatrics and Pathology and Nursing, University of Michigan, Ann Arbor 48109-0404, USA
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