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Journal articles on the topic 'Polyvinyl chloride Testing'
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1
Bezanson, Gregory, Susan Burbridge, David Haldane, and Thomas Marrie. "In situ colonization of polyvinyl chloride, brass, and copper by Legionella pneumophila." Canadian Journal of Microbiology 38, no. 4 (April 1, 1992): 328–30. http://dx.doi.org/10.1139/m92-055.
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A sampling device (Robbins device) was used to expose brass, copper, and polyvinyl chloride plugs to potable water contaminated by Legionella pneumophila serogroup 1. Plugs were removed at approximately 1-week intervals and cultured. The colonization rates were polyvinyl chloride, 70; copper, 31; and brass, 25%. Quantitative cultures revealed that polyvinyl chloride was most heavily colonized, whereas brass was least colonized. We conclude that materials used in plumbing systems are readily colonized by Legionella and that the Robbins device provides a means for testing such materials in an in situ setting. Key words: Legionella, colonization, plumbing materials.
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Palshin, V. A., E. N. Danilovtseva, M. S. Strelova, S. N. Zelinskiy, and V. V. Annenkov. "Fluorescent nanoplastic particles: synthesis and influence on diatoms." Limnology and Freshwater Biology, no. 5 (2020): 1067–72. http://dx.doi.org/10.31951/2658-3518-2020-a-5-1067.
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A method for obtaining fluorescent labeled polyvinyl chloride nanoparticles of 60-110 nm by deposition of plastic and dye solution into water has been developed. These nanoparticles are suitable for testing effect of nanoplastic on living organisms. We have cultivated diatom algae Ulnaria ferefusiformis in the presence of polyvinyl chloride nanoparticles and revealed that the suppression of the vital activity in diatoms is not due to the penetration of nanoparticles into the cell but arises from their association with the outer surface of the cells near the labiate process (rimoportula).
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Kweon, Deok-Jun, Ki-In Choi, Hui-Jeong Eom, Jae-In Lee, and Zel-Ho Choi. "Development of the testing method for vinyl chloride monomer (VCM) in polyvinyl chloride(PVC) samples." Analytical Science and Technology 25, no. 6 (December 25, 2012): 395–401. http://dx.doi.org/10.5806/ast.2012.25.6.395.
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Hosseini, Payam, Sultan Alhomair, Zahra Faeli, Mohammad Pour-Ghaz, Mohammed Gabr, Detlef Knappe, and Cyrus Parker. "Degradation Model for the Tensile Strength of PVC and Rubber Gasket Materials Exposed to Benzene and PCE-Saturated Aqueous Solutions." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 2 (February 2020): 274–83. http://dx.doi.org/10.1177/0361198120906126.
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In this paper, a tensile strength degradation model is developed for polyvinyl chloride (PVC) pipe and three rubber gasket materials commonly used in stormwater drains and wet utilities; the degradation model considers exposure to a single contaminant at its saturation level. The contaminant considered included benzene and tetrachloroethylene (PCE) because of their prevalence. The materials considered are unplasticized Polyvinyl chloride (u-PVC) utilized as the pipe material, and three types of rubber gaskets: Polychloroprene (Neoprene-CR), Acrylonitrile (nitrile) butadiene rubber (Buna-N), and fluoroelastomer rubber (FKM—Grade A VitonTM). First, the degradation rates of these materials are experimentally quantified using accelerated testing; then using the experimental results and Williams–Landel–Ferry (WLF) method a degradation model is developed. Finally, a simplified method is introduced to relate the tensile strength degradation of PVC to the penetration rate of the contaminants.
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Yang, Ruiyue, Zhongwei Huang, Gensheng Li, Kamy Sepehrnoori, Qing Lin, and Chengzheng Cai. "Integrity Testing of a Polyvinyl Chloride Slotted Liner for Horizontal Coalbed-Methane Wells." SPE Drilling & Completion 32, no. 02 (June 1, 2017): 086–96. http://dx.doi.org/10.2118/185958-pa.
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Li, Huabei, Xiaolin Wang, Hongying Chu, and Xinding Yao. "Synthesis of a polyester plasticizer from rubber seed oil for polyvinyl chloride." Polish Journal of Chemical Technology 24, no. 4 (December 1, 2022): 1–6. http://dx.doi.org/10.2478/pjct-2022-0023.
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Abstract A polyester plasticizer (RSOP) for polyvinyl chloride based on rubber seed oil (RSO) was synthesized. Firstly, RSO monoglyceride were synthesized by the transesterification of RSO with glycerol at 220–240 °C. Secondly, RSOP was synthesized from RSO monoglyceride and adipic acid by esterification. The polyester plasticizer was characterized by GPC, FT-IR, 1H NMR and DSC. Plasticized polyvinyl chloride (PVC) materials with RSOP and dioctyl phthalate (DOP) in varying ratios were prepared via thermal melting process, RSOP was used as a second plasticizer. The properties of the plasticized PVC materials were characterized by a universal testing machine, TGA, DMA and solvent extraction resistance. The obtained PVC materials showed improved thermal stability and lower glass transition temperature than PVC. Solvent extraction resistance and plasticization of plasticized PVC were also improved. This study provides a new strategy for preparing bio-based polyester plasticizer from RSO.
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Lingenfelter, Peter, Bartosz Bartoszewicz, Jan Migdalski, Tomasz Sokalski, Mirosław M. Bućko, Robert Filipek, and Andrzej Lewenstam. "Reference Electrodes with Polymer-Based Membranes—Comprehensive Performance Characteristics." Membranes 9, no. 12 (November 29, 2019): 161. http://dx.doi.org/10.3390/membranes9120161.
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Several types of liquid membrane and solid-state reference electrodes based on different plastics were fabricated. In the membranes studied, equitransferent organic (QB) and inorganic salts (KCl) are dispersed in polyvinyl chloride (PVC), polyurethane (PU), urea-formaldehyde resin (UF), polyvinyl acetate (PVA), as well as remelted KCl in order to show the matrix impact on the reference membranes’ behavior. The comparison of potentiometic performance was made using specially designed standardized testing protocols. A problem in the reference electrode research and literature has been a lack of standardized testing, which leads to difficulties in comparing different types, qualities, and properties of reference electrodes. Herein, several protocols were developed to test the electrodes’ performance with respect to stability over time, pH sensitivity, ionic strength, and various ionic species. All of the prepared reference electrodes performed well in at least some respect and would be suitable for certain applications as described in the text. Most of the reference types, however, demonstrated some weakness that had not been previously highlighted in the literature, due in large part to the lack of exhaustive and/or consistent testing protocols.
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Krivushina, A. A., D. V. Sevastyanov, E. A. Shein, M. I. Daskovsky, Z. Usagawa, G. P. Avilleira, and M. G. Batista. "STUDY FOR DESTRUCTIVE INFLUENCE OF MICROMYCETE STRAINS, ISOLATED UNDER CLIMATIC CONDITIONS OF THE REPUBLIC OF CUBA, ON POLYMER FILM MATERIALS." Proceedings of VIAM, no. 4 (2021): 141–50. http://dx.doi.org/10.18577/2307-6046-2021-0-4-141-150.
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A laboratory study for biodegradation of polymer film materials (high-density and low-density polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride) under the action of mircomycete strains isolated under conditions of the island of Cuba was carried out. The maximum growth of micromycetes was observed in case of PVC samples. The minimum level of biodegradation for PVC films revealed at the mould resistance test (28 days) was confirmed by the results of tensile testing.
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Trias Atmadja, Wahyu Mahendra, Herman Parung, Rita Irmawaty, and A. Arwin Amiruddin. "Behavior Hollow Concrete Reinforced Slab with The Utilization of Polyvivyl Chloride Pipe as a Cavity." Open Civil Engineering Journal 15, no. 1 (July 12, 2021): 172–81. http://dx.doi.org/10.2174/1874149502115010172.
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Background: Slab weight can be reduced by replacing the amount of concrete in the tensile area with the utilization of modification polyvinyl chloride pipe as cavity without reducing the flexural strength because the nature of concrete is weak against tensile strength. Methods: This research with the experimental method using static load. The setting of tools refers to the American Society for Testing and Material E 2322, bending analysis is used moment coefficient method, deflection by applying Ugural and Navier method, and shear analysis using Indonesia National Standard 03-2847-2019. Results: The specimens consist of solid plates with a thickness of 140 mm and hollow plates with a thickness of 140 mm and 159 mm. The maximum load capacity solid plate is 410.642 kN, while the hollow plates (140 mm) is 335.18 kN, and for the hollow plates 159 mm is 396.257 kN. The solid plate’s stiffness is 16.321, the hollow plates 140 mm is 14.787 and the hollow plate 159 mm is 24.194, while the ductility is 1.993 on solid plate, the hollow plate 140 mm is 2.014, and the hollow plate 159 mm is 1.862. The solid plate’s damage is flexural, while the two hollow plates are a combination of bending and shear damage. The crack pattern on the solid plates is flexible, while the crack pattern on both hollow plates is a combination of flexural cracks and shear cracks. Conclusion: The use of modified polyvinyl chloride pipes can be recommended in the structure of the plate. There is a small, insignificant difference in the flexural behaviour between the solid plate and hollow concrete reinforced slab with the utilization of Polyvinyl Chloride.
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Torres, L. M., João Pedro Nunes, João F. Silva, and António Torres Marques. "New PVC Matrix Towpregs and Composites." Materials Science Forum 587-588 (June 2008): 241–45. http://dx.doi.org/10.4028/www.scientific.net/msf.587-588.241.
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A cost efficient powder coating technology developed in previous work [1-3] was modified to produce glass fibre/polyvinyl chloride (GF/PVC) towpregs that were subsequently processed by compression moulding and filament winding. The production of GF/PVC towpregs was optimized and a process window established. The composite structures obtained were submitted to mechanical testing and the results compared with the theoretical predictions made using the classical laminate theory (CLT). The obtained results showed that the GF/PVC composites properties are compatible with all major engineering applications.
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KOGA, Yasutomo, Yoshihiko ARAO, and Masatoshi KUBOUCHI. "Application of small punch (SP) testing to residual lifetime prediction for polyvinyl chloride (PVC) cable jacket." Proceedings of Mechanical Engineering Congress, Japan 2019 (2019): J17105P. http://dx.doi.org/10.1299/jsmemecj.2019.j17105p.
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Kieu, Thi Quynh Hoa, Huu Trung Tran, Duc Huynh Mai, Huu Dat Nguyen, and Vu Giang Nguyen. "Study on the isolation of marine bacterial strains capable of degrading polyvinyl chloride." Ministry of Science and Technology, Vietnam 64, no. 11 (November 25, 2022): 27–31. http://dx.doi.org/10.31276/vjst.64(11).27-31.
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Polyvinyl chloride (PVC) is a widely used plastic due to its good mechanical properties and thermal resistance. However, despite of its advantages, the persistent nature of PVC makes it challenging to dispose when released into the environment, thereby causing harm to human health and the environment. Recent research has revealed that specialised marine microbes (such as bacteria, fungi, and actinomycetes) have the potential to biodegrade plastics and utilise many of them as the sole source of carbon. In this study, PVC degrading bacteria were enriched and isolated from plastic waste contaminated coastal areas in Vietnam. From 18 isolates of bacteria, the authors selected the VK3 strain capable of degrading PVC and used this material as the sole carbon source after 8 weeks of testing. The results of 16S rRNA gene sequence analysis showed that this bacterial strain has 99% similarity with Alcanivorax sp. The changes in surface structure and functional groups of PVC was also demonstrated by Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). These results revealed promising evidences of PVC degradation by marine bacteria.
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Lei, Jingfa, Yan Xuan, Tao Liu, Feiya Duan, Zhan Wei, and Chen Lu. "Static and Dynamic Tensile Mechanical Behavior of Polyvinyl Chloride Elastomers with Different Shore Hardness." Shock and Vibration 2021 (March 8, 2021): 1–10. http://dx.doi.org/10.1155/2021/8887242.
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An experiment on the static and dynamic tensile mechanical properties of polyvinyl chloride (PVC) elastomers is conducted using an Instron-5943 universal testing machine and an improved Split Hopkinson Tensile Bar to study the dynamic tensile mechanical properties of PVC elastomer materials. The stress-strain curves of PVC materials with three types of Shore hardness (57A, 52A, and 47A) under the strain rates of 0.1 s−1 and 400 ∼ 1800 s−1 are obtained. Results show that the mechanical behavior of PVC elastomer materials with different Shore hardness has remarkable linear elastic characteristics under the action of quasistatic tensile load. It has substantial sensitivity to strain rate and viscoelastic mechanical characteristics under the action of dynamic tensile load. The Zhu–Wang–Tang nonlinear viscoelastic constitutive model is used to characterize the viscoelastic mechanical characteristics with small error. This paper can provide theoretical model and method support for the design, development, production, and reliability analysis of PVC elastomers and other soft polymer materials.
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NIINO, Tatsuhiro, Takayuki ASAKURA, Tohru ISHIBASHI, Takeshi ITOH, Senzo SAKAI, Hajimu ISHIWATA, Takashi YAMADA, and Sukeo ONODERA. "A Simple and Reproducible Testing Method for Dialkyl Phthalate Migration from Polyvinyl Chloride Products into Saliva Simulant." Journal of the Food Hygienic Society of Japan (Shokuhin Eiseigaku Zasshi) 44, no. 1 (2003): 13–18. http://dx.doi.org/10.3358/shokueishi.44.13.
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Mironyak, Maria, Olena Volnyanska, Oksana Labyak, Vadym Kovalenko, and Valerii Kotok. "DEVELOPMENT OF A POTENTIOMETRIC SENSOR SENSITIVE TO POLYSORBATE 20." EUREKA: Physics and Engineering 4 (July 31, 2019): 3–9. http://dx.doi.org/10.21303/2461-4262.2019.00942.
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Polyoxyethylated sorbitans (polysorbates) are widely used in the chemical, pharmaceutical, and cosmetic industries, but only quantitative determination is used mainly for chromatographic methods. In this paper, the results of the development and testing of a potentiometric sensor sensitive to nonionic surfactant polyoxyethylene sorbitan monolaurate (polysorbate-20) are presented. An anion of the heterogeneous acid of the Keggin structure (12-molybdophosphate heteropolyacid) was used as a counterion to obtain the electrode-active substance for the potentiometric sensor membrane. Polysorbate-20 does not form cations when dissociating in water and cannot directly interact with heteropolyanion; therefore, a cationic complex of polysorbate-20 with barium ions was previously prepared (similar to the interaction of metals with crown ethers). The resulting ion associate meets the basic requirement for the electrode-active substance of plasticized film polyvinyl chloride membranes of potentiometric sensors (poor water solubility and good solubility in organic solvents). Phthalic acid derivatives (dibutyl phthalate and dioctyl phthalate) were used as solvent-plasticizers for a polyvinyl chloride membrane. To determine the optimum conditions for the functioning of a potentiometric sensor sensitive to polysorbate-20, the influence of various factors on the electrode characteristics was studied. Quantitative content of the ionic associate in the polyvinyl chloride membrane, the nature of the membrane solvent-plasticizer, pH of a series of standard polysorbate-20 solutions) on the electrode characteristics of the plasticized membrane of the potentiometric sensor (sensitivity or slope of the electrode function, lower limit of linearity and minimum detectable concentration of polysorbate-20, which can be determined with the help of the developed potentiometric sensor) was studied. The optimal conditions for using the developed potentiometric sensor were found. The developed sensor allows for a short period of time (5–10 min) determining the quantitative content of polysorbate-20 in industrial products at the level 10–5–10‑6 mol/l. The potentiometric sensor sensitive to polysorbate-20 can be used for the development of a potentiometric method for determining the clinical reception of polysorbate-20 in various types of industrial products.
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Borók, Alexandra, Kristóf Laboda, and Attila Bonyár. "PDMS Bonding Technologies for Microfluidic Applications: A Review." Biosensors 11, no. 8 (August 23, 2021): 292. http://dx.doi.org/10.3390/bios11080292.
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This review summarizes and compares the available surface treatment and bonding techniques (e.g., corona triggered surface activation, oxygen plasma surface activation, chemical gluing, and mixed techniques) and quality/bond-strength testing methods (e.g., pulling test, shear test, peel test, leakage test) for bonding PDMS (polydimethylsiloxane) with other materials, such as PDMS, glass, silicon, PET (polyethylene terephthalate), PI (polyimide), PMMA (poly(methyl methacrylate)), PVC (polyvinyl chloride), PC (polycarbonate), COC (cyclic olefin copolymer), PS (polystyrene) and PEN (polyethylene naphthalate). The optimized process parameters for the best achievable bond strengths are collected for each substrate, and the advantages and disadvantages of each method are discussed in detail.
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Liu, Jian Ping, Hong Zhou Shang, Xia Song, Wei Yuan, and Shu Mei Zhou. "Evaluation of the Thermal Stabilization Effect of the Bis (Mercaptoethanol Oleate) Dimethyl Tin on Polyvinyl Chloride." Advanced Materials Research 581-582 (October 2012): 81–84. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.81.
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Bis (mercaptoethanol oleate) dimethyl tin was synthesized and added to polyvinyl chloride (PVC) with various ratios. Specimens were prepared by mixing and rolling through a double-roller mixer, and their static thermal stabilities were estimated by the oven static thermal aging experiments. The influence of the bis (mercaptoethanol oleate) dimethyl tin on the dynamic thermal stability of PVC was tested through a haack torque rheometer (HAAKE PolyLab QC). The tensile strength and rate of elongation at break of the PVC specimens were evaluated by a servo-controlled tensile testing machine. The results show that the bis (mercaptoethanol oleate) dimethyl tin has excellent static and dynamic thermal stabilization effect on PVC, and to some extent, can improve the breaking elongation rate the PVC sample.
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PATIL, C. B., P. S. SHISODE, U. R. KAPADI, D. G. HUNDIWALE, and P. P. MAHULIKAR. "EFFECT OF CALCIUM SULPHATE NANOPARTICLES ON FUSION, MECHANICAL AND THERMAL BEHAVIOUR POLYVINYL CHLORIDE (PVC)." International Journal of Modern Physics B 24, no. 01n02 (January 20, 2010): 64–75. http://dx.doi.org/10.1142/s0217979210063995.
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Calcium Sulphate [ CaSO 4] was synthesized by in-situ deposition technique and its nano size (60 to 100 nm) was confirmed by Transmission Electron Microscopy (TEM). Composites of the filler CaSO 4 (micro and nano) and the matrix poly (vinyl chloride) ( PVC ) were prepared with different filler loading (0-5 wt. %) by melt mixing. The Brabender torque rheometer equipped with an internal mixer was used for preparation and evaluation of fusion behaviour of composites of different formulations. The effect of nano and micro- CaSO 4 content on the structure and properties of composites was studied. The nanostructures and dispersion were studied by wide angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). The mechanical and thermal properties of PVC / micro and nano- CaSO 4 composites were characterized using Universal Testing Machine (UTM) and Thermo Gravimetric Analyzer (TGA). From the results of WAXD and SEM the flocculation of CaSO 4 nanoparticles were observed on the surfaces of PVC matrix. The thermal analysis results showed that the first thermal degradation onset (T onset) of PVC /nano- CaSO 4 composites for 1 wt. % of filler were higher as compared with corresponding microcomposites and pristine PVC . However, the tensile strength was decreasing with increasing filler content while, it shows increment in magnitude at 1 and 2 wt. % of nano- CaSO 4 as compared with corresponding micro- CaSO 4 as well as pristine PVC .
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Castro, Alexandra, Cândida Vilarinho, Delfim Soares, and Fernando Castro. "Kinetic Study of Thermal De-Chlorination of PVC-Containing Waste." Materials Science Forum 730-732 (November 2012): 611–16. http://dx.doi.org/10.4028/www.scientific.net/msf.730-732.611.
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The presence of organic compounds on wastes, especially plastics, is considered an important source of energy. However, most of these plastics contain polyvinyl chloride (PVC), causing recycling problems when it is considered a thermal valorization process for its treatment [1], preventing the use of those residues on these processes, which main goal is the energy recovery [2,3]. A possible solution is to remove the chlorine from PVC containing waste through a pyrolysis process before being subjected to a thermal treatment, for energetic valorization. In this work, it was developed a kinetic model for the thermal decomposition of PVC, in view of its de-chlorination. DTA/TGA testing were performed at different temperatures (between the range of decomposition temperatures of the PVC molecule) indicated a first order reaction and an activation energy of 133800 J/mol, value very close to the one obtained in others works reported [4]. A factorial plan was carried out with different temperatures, performed in lab scale, in which best results were obtained at the temperature of 340 °C, proving the kinetic model obtained.
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Seo, Hogeon, Kyoungjun Lee, and Kyung-Young Jhang. "In-Line Ultrasonic Monitoring for Sediments Stuck on Inner Wall of a Polyvinyl Chloride Pipe." Scientific World Journal 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/731621.
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This research verified the applicability and effectiveness of the ultrasonic monitoring of sediments stuck on the inner wall of polyvinyl chloride (PVC) pipes. For identifying the transmittance of acoustic energy and the speed of sound in the PVC material, the pulse-echo ultrasonic testing was conducted for PVC sheets of different thicknesses. To simulate the solidified sediment, the hot melt adhesive (HMA) was covered on the inner wall of the PVC pipe in different heights. From the experiment, the speeds of sound in the PVC and the HMA materials were obtained as about 2258 and 2000 m/s, respectively. The thickness of the materials was calculated through the signal processing such as taking the absolute value and low pass filtering, the echo detection, and the measurement of the time of flight. The errors between actual and measured thicknesses of PVC sheets were below 5%. In the case of the substance stuck on the inner wall, the errors were below 2.5%. Since the pulse-echo ultrasonic inspection is available on the outer surface and its measurement accuracy was over 95%, it can be an efficient and effective in-service structural health monitoring for the sediment on the wall of PVC pipes.
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Yadav, Mohana, Sushil Manderia, Shweta Singh, and Mohd Adil Deva. "Isolation and Characterization of Polyvinyl Chloride (PVC) Degrading Bacteria from Polluted Sites of Gwalior City, M.P., India." Nature Environment and Pollution Technology 21, no. 1 (March 6, 2022): 201–7. http://dx.doi.org/10.46488/nept.2022.v21i01.022.
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Plastic is harmful to nature and this issue could be solved by its degradation. Biodegradation of plastic waste utilizing bacterial strain is an eco-friendly approach. In this study, top bacterial strains that degrade the polymeric ingredient of the polymer polyvinyl chloride (PVC) were isolated and identified using a development culture procedure. For this investigation, soil from various contaminated areas was collected, which had abundant plastic waste. The biodegradation of polyvinylchloride films was studied using a liquid culture approach for six months. A couple of bacterial organism packs were then limited to emulsifying the commonly used PVC polymer in agar media. The PVC strain showed particular degradation and was chosen for further testing because the species Bacillus and Micrococcus were considered more credible. Bacillus and Micrococcus species have both proven the biodegradability of PVC based on the mean weight decrease, which was 0.873 for Bacillus species and 0.916 for Micrococcus species after a period of around six months. The FTIR study confirmed the breaking down by demonstrating the proximity of porosity and sensitivity of bacteria-infested polythene surfaces. Bacillus has a higher degradation potential than Micrococcus in our research.
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Aldrich, Jeffrey R., Qing-He Zhang, and Aijun Zhang. "Synergistic Chemical Attraction of the Eastern Yellowjacket, Vespula maculifrons (Hymenoptera: Vespidae)." Journal of Entomological Science 39, no. 4 (October 1, 2004): 643–53. http://dx.doi.org/10.18474/0749-8004-39.4.643.
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Combinations of (E)-2-hexenal diethyl acetal, racemic α-terpineol or linalool, with or without benzyl alcohol incorporated into polyvinyl chloride attracted wasps in the Vespula vulgaris species group, including the Eastern, Vespula maculifrons (Buysson), and German, V. germanica (F.), yellowjackets. (E)-2-Hexenal diethyl acetal degrades to release (E)-2-hexenal (the active attractant form) and ethanol, which may help kill yellowjackets caught in the water inside the traps used for testing. Combining the (E)-2-hexenal diethyl acetal/α-terpineol or linalool mixtures with another blend previously reported as attractive to yellowjackets (acetic acid/isobutanol) synergistically attracted the Eastern yellowjacket. It is hypothesized that the synergistic attraction is a result of combining volatile chemicals associated with carbohydrate feeding (acetic acid/isobutanol) and volatiles associated with foraging for insect prey (hexenal/α-terpineol or linalool).
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Rostam, Sarkawt, Alan Kareem Ali, and Firdaws Haidar AbdalMuhammad. "Experimental Investigation of Mechanical Properties of PVC Polymer under Different Heating and Cooling Conditions." Journal of Engineering 2016 (2016): 1–5. http://dx.doi.org/10.1155/2016/3791417.
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Due to a widely increasing usage of polymers in various industrial applications, there should be a continuous need in doing research investigations for better understanding of their properties. These applications require the usage of the polymer in different working environments subjecting the material to various temperature ranges. In this paper, an experimental investigation of mechanical properties of polyvinyl chloride (PVC) polymer under heating and cooling conditions is presented. For this purpose standard samples are prepared and tested in laboratory using universal material testing apparatus. The samples are tested under different conditions including the room temperature environment, cooling in a refrigerator, and heating at different heating temperatures. It is observed that the strength of the tested samples decreases with the increasing of heating temperature and accordingly the material becomes softer. Meanwhile the cooling environments give a clear increasing to the strength of the material.
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Techawinyutham, Laongdaw, Arnuparb Prasarnsri, Suchart Siengchin, Rapeephun Dangtungee, and Sanjay Mavinkere Rangappa. "Anti-Gnawing, Thermo-Mechanical and Rheological Properties of Polyvinyl Chloride: Effect of Capsicum Oleoresin and Denatonium Benzoate." Journal of Composites Science 6, no. 1 (December 27, 2021): 8. http://dx.doi.org/10.3390/jcs6010008.
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Anti-rodent polymer composites were prepared using non-toxic substances denatonium benzoate (DB) and capsicum oleroresin (CO) mixed with polyvinyl chloride (PVC) matrix. DB is mixed in zinc stearate (ZnSt) called DB/ZnSt, and CO, providing burning sensation, is impregnated in mesoporous silica named SiCO. There are three sets of sample: Blank, composites Set I and Set II. Set I consists of DB/ZnSt at concentration of 1.96 wt% and SiCO at concentration of 12.16 wt%, 14.47 wt%, 18.75 wt% and 23.53 wt%. Set II comprises SiCO at the same amount of Set I. The anti-rodent composites studied are anti-gnawing, surface morphology, thermo-mechanical and rheological properties. Anti-rodent testing is analyzed by one-way blocked analysis of variance (ANOVA) and compared with Tukey test with a 95% level of significance, presenting good anti-gnawing efficiency. The best rat-proof sample is II.4, consisting of SiCO 23.53 wt%, which presents percentage of weight loss from gnawing at 1.68% compared to weight loss of neat PVC at 59.74%. The addition of SiCO at concentration ranging from 12.16 to 23.53 wt% reduces tensile strength around 25–50%, elongation at break strength around 2–23%, shear storage modulus (G′) around 30%, shear loss modulus (G″) shear viscosity (η) and glass transition (Tg) around 43% compared to Blank. The increase in SiCO concentration slightly improves the thermal stability of PVC composites around 3%, but the addition of DB/ZnSt at 1.96 wt% slightly reduces those properties.
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Cupido, Anthony, Brian Baetz, Yiping Guo, and Anna Robertson. "An evaluation of rainwater runoff quality from selected white roof membranes." Water Quality Research Journal 47, no. 1 (February 1, 2012): 66–79. http://dx.doi.org/10.2166/wqrjc.2012.011.
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While there has been research on rainwater quality and quantity from green roofs and some conventional roof systems, there does not appear to be any significant study regarding the quality of rainwater harvested from selected white membrane roof systems and subsequently treated for potable use in an urban, institutional setting. A new Leadership in Energy and Environmental Design (LEED®) Canada Gold facility on the campus of McMaster University in Hamilton, Canada offered an excellent opportunity to analyze the quality of rainwater from different roof assemblies. Field research was undertaken on the evaluation of three white roof membranes: modified bitumen finish ply, polyvinyl chloride (PVC), and thermoplastic polyolefin (TPO); and their effects on the runoff water quality were studied. An analysis of the quality of runoff was performed from each of these three membranes and compared with Ontario provincial drinking water standards. This paper provides the results of runoff quality testing on these membranes and their suitability for future institutional green building applications.
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Duan, Guoyan, Chunxia He, Min Wang, Xingxing Yang, Wei Wang, and Yanping Wang. "Effect of silica on thermal and mechanical properties of eucalyptus-PVC wood-polymer composites." BioResources 18, no. 1 (2023): 1803–11. http://dx.doi.org/10.15376/biores.18.1.1803-1811.
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Wood plastic composites (WPCs) were prepared by extrusion molding with eucalyptus powder, polyvinyl chloride (PVC), and silica as additives. The mechanical properties, creep behavior, thermal properties, and cross-section microstructure of the composites were analyzed by universal testing machine, thermogravimetric analyzer, and scanning electron microscope. The results show that with the increase of silica content, the tensile strength, bending strength, and impact strength of the WPCs first increased and then decreased. When the silica content was 3.0%, the tensile strength, bending strength, and impact strength of WPC reached the maximum values of 27.5 MPa, 48.8 MPa, and 4.18 KJ·m-2, respectively, which represented increases of 12.6%, 9.4%, and 20.1%, respectively, compared with those without silica. When the stress was 13.4 MPa, the strain value of 3.0% SiO2-eucalyptus/PVC wood plastic composite was 3.3 times that of 4.46 MPa and 1.7 times that of 8.92 MPa. The pyrolysis process of eucalyptus/PVC WPCs showed a similar trend with different silica content.
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Peterside, David T., Joseph E. Palaia, Andrew C. Schuerger, Melanie J. Correll, and Ray A. Bucklin. "Testing of Greenhouse Cladding Materials for Space Environments, Part 2: Laminates." Applied Engineering in Agriculture 34, no. 3 (2018): 575–80. http://dx.doi.org/10.13031/aea.12465.
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Abstract. Plants grown in greenhouse-type structures are potential sources of food, oxygen, clean water, fiber, and other resources needed for bioregenerative life support systems during long-term space missions. Identification of cladding materials with appropriate optical and physical properties that can withstand the high ultraviolet radiation, low pressure, and low temperature Martian environment is necessary for greenhouse design. The objective of this study was to evaluate the effects of simulated Mars environmental conditions on yield strength and light transmissivity of composites composed of a layer of 0.15 mm polyimide film (LaRC™CP1) attached to acrylic, polyvinyl chloride (PVC), or polycarbonate cladding materials. The University of Florida’s Mars Simulation Chamber (MSC) at Kennedy Space Center was utilized to expose material samples to simulated Mars environmental conditions. Changes in control versus exposed material sample transmissivities were measured using a spectroradiometer over the PAR range of wavelengths from 400 to 700 nm and material peak yield strengths were determined using an Instron universal testing machine. Keywords: LaRC™CP1, Mars greenhouse, PAR transmission, Plastics, Strength of materials, UV damage.The overall results comparing pre- and post-exposure of samples to simulated Martian conditions in the MSC showed that the addition of a layer of polyimide did not benefit either the transmissivity or strength of polycarbonate cladding materials, but did show benefits in retaining transmissivity for PVC and in maintaining strength for acrylics exposed to Mars simulated environment. However, transmissivities of the plastics were reduced by the addition of protective layers of polyimide. Keywords: LaRC™CP1, Mars greenhouse, PAR transmission, Plastics, Strength of materials, UV damage.
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Bayldon, John, Zdeněk P. Bažant, Isaac M. Daniel, and Qiang Yu. "Size Effect on Compressive Strength of Sandwich Panels with Fracture of Woven Laminate Facesheet." Journal of Engineering Materials and Technology 128, no. 2 (November 2, 2005): 169–74. http://dx.doi.org/10.1115/1.2172277.
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Prismatic sandwich specimens of various sizes, geometrically scaled in the ratio 1:2:4:8, are subjected to eccentric axial compression and tested to failure. The sandwich core consists of a closed-cell polyvinyl chloride foam, and the facesheets are woven glass-epoxy laminates, scaled by increasing the number of plies. The test results reveal a size effect on the mean nominal strength, which is strong enough to require consideration in design. The size effect observed is fitted with the size effect law of the energetic (deterministic) size effect theory. However, because of inevitable scatter and limited testing range, the precise form of the energetic size effect law to describe the test results is not unambiguous. The Weibull-type statistical size effect on the mean strength is ruled out because the specimens had small notches which caused the failure to occur in only one place in the specimen, and also because the observed failure mode was kink band propagation, previously shown to cause energetic size effect. Various fallacies in previous applications of Weibull theory to composites are also pointed out.
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Kazys, Rymantas Jonas, Justina Sestoke, and Egidijus Zukauskas. "Numerical Investigation of Excitation of Various Lamb Waves Modes in Thin Plastic Films." Applied Sciences 12, no. 2 (January 14, 2022): 849. http://dx.doi.org/10.3390/app12020849.
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Ultrasonic-guided waves are widely used for the non-destructive testing and material characterization of plates and thin films. In the case of thin plastic polyvinyl chloride (PVC), films up to 3.2 MHz with only two Lamb wave modes, antisymmetrical A0 and symmetrical S0, may propagate. At frequencies lower that 240 kHz, the velocity of the A0 mode becomes slower than the ultrasonic velocity in air which makes excitation and reception of such mode complicated. For excitation of both modes, we propose instead a single air-coupled ultrasonic transducer to use linear air-coupled arrays, which can be electronically readjusted to optimally excite and receive the A0 and S0 guided wave modes. The objective of this article was the numerical investigation of feasibility to excite different types of ultrasonic-guided waves, such as S0 and A0 modes in thin plastic films with the same electronically readjusted linear phased array. Three-dimensional and two-dimensional simulations of A0 and S0 Lamb wave modes using a single ultrasonic transducer and a linear phased array were performed. The obtained results clearly demonstrate feasibility to excite efficiently different guided wave modes in thin plastic films with readjusted phased array.
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Hoh, Sam, Tim Helps, Richard Suphapol Diteesawat, Majid Taghavi, and Jonathan Rossiter. "Electro-lattice actuator: a compliant high-contractile active lattice structure." Smart Materials and Structures 30, no. 12 (November 15, 2021): 125034. http://dx.doi.org/10.1088/1361-665x/ac2ba9.
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Abstract Electro-ribbon actuators are high-performance electrically-driven artificial muscles with high flexibility, low mass, low power consumption, high contraction, and high force-to-weight ratio. They show great promise for driving the deployment of compact folding structures. This article presents the electro-lattice actuator (ELA), a compliant, three-dimensional, free-standing lattice structure that uses this phenomenon to contract to a flat sheet upon the application of a potential difference. The ELA was designed in the form of multiple interconnected buckled structures and fabricated using polyvinyl chloride sheets and tape and copper electrodes. The ELA structure was pre-set into an open-cell configuration by annealing in an oven. Isometric testing at varying compressions showed that the tensile stress of the proposed lattice actuator reaches a maximum of 184 Pa (a 472 Pa change in tensile stress compared with its unactuated state). A cuboid shaped ELA (13.6 cm length × 10.0 cm width × 5.4 cm height) achieved a contraction of 92.6% and a contraction rate of 35.6% s−1. The novel ELA opens up the use of electro-ribbon actuation to more complex and more effective 3D actuating and deploying structures.
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Setiawan, Ikhsan, and Mulaiyinatus Sifa. "The construction and testing of an acoustic energy harvester consisting of a Helmholtz resonator and a loudspeaker." Journal of Physics: Theories and Applications 4, no. 1 (March 29, 2020): 8. http://dx.doi.org/10.20961/jphystheor-appl.v4i1.47587.
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Sound energy is all around but not properly utilized despite being a source of electricity. This research was conducted to construct and test an acoustic energy harvester consisting of a Helmholtz resonator and a loudspeaker. The resonator cavity was made of 10 mm-thick cube-shaped acrylic plates with an inner side length of 300 mm while its neck was made of PVC (polyvinyl chloride) pipes with an inner diameter of 55 mm and three length variations at 50 mm, 70 mm, and 90 mm. A 6-inch subwoofer loudspeaker was mounted on the resonator back wall facing the cavity with its terminals connected to a 100-ohm load resistor. The sound waves entering the resonator cavity through the neck were converted into the alternating electric current flowing through the resistor. The test was conducted experimentally by exposing the harvester to sound waves at a maximum sound pressure level (SPL) of 100 dB and frequency variations from 25 Hz to 200 Hz. The root-mean-square (rms) voltages across the resistor were measured to calculate the output rms values for electric power. The results showed seven spectrum peaks which appeared at frequencies of 31 Hz, 37 Hz, 41 Hz, 49 Hz, 58 Hz, 73 Hz, and 82 Hz. Moreover, a shorter neck was also observed to have produced higher output power as indicated by the highest value of 2.75 mW obtained by using a 50 mm-long resonator neck at 37 Hz frequency and 100 dB SPL. These findings showed the acoustic energy harvester used to be effective due to its ability to produce electricity even at low frequencies below 100 Hz.
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Tyagi, S. K., P. Kinjavdeka, Sharma Amarpal, A. M. Pawde, T. Srivastava, J. Singh, D. N. Madhu, and H. P. Aithal. "In vitro biomechanical testing of different configurations of acrylic external skeletal fixator constructs." Veterinary and Comparative Orthopaedics and Traumatology 28, no. 04 (2015): 227–33. http://dx.doi.org/10.3415/vcot-14-07-0102.
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SummaryObjective: To evaluate the in vitro biomechanical properties of four different configurations of acrylic external skeletal fixator constructs.Materials and methods: Simulated bone constructs were prepared using two segments of 20 mm ultra-high-density polyethylene rods with a gap of 5 mm. The full pins (1.5 mm) were passed through the proximal and distal segments of ultra-high-density polyethylene rods, in the same plane, parallel to each other in configuration U, and were crossed in the M1, M2 and C configurations at a 90° angle to each other. Configuration U was a single bilateral uniplanar construct, M1 was a double orthogonal bilateral construct, M2 was a double orthogonal bilateral construct with proximal and distal connecting articulations, and C was a double orthogonal bilateral construct with proximal and distal circumferential articulations. Temporary scaffolds of different external skeletal fixator configurations were constructed using commercially available polyvinyl chloride pipes (20 mm) connected and secured to the fixation pins at a fixed distance from the rods. Acrylic powder (polymer) mixed with liquid (monomer) was poured into the pipes and allowed to solidify to form the side bars and rings. The external skeletal fixator constructs were then subjected to axial compression, cranio-caudal three-point bending and torsion (n = 4 each) using a universal testing machine. Mechanical parameters, namely stress, strain, modulus of elasticity, stiffness and bending moment of fixator constructs, were determined from load-displacement curves.Results: Configuration U was the weakest and configuration C was the strongest under all the testing modes. Under compression, the M1, M2 and C configurations were similar. Under bending, a significant difference was observed among the uniplanar, multi -planar and circular configurations with no difference between M1 and M2. However, under torsion, all the external skeletal fixator configurations differed significantly.Clinical significance: The freeform external skeletal fixator using acrylic as a replacement for a metallic bar may be useful to treat bone fractures and luxations in small animals, as it is mechanically strong, lightweight, economical, and pins can be passed from any direction depending upon the clinical situation.
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Chen, Xi, Jiabin Gao, Yunchang Song, Yaping Gong, Meng Qi, and Runlong Hao. "Fabrication of a High Water Flux Conductive MWCNTs/PVC Composite Membrane with Effective Electrically Enhanced Antifouling Behavior." Coatings 11, no. 12 (December 16, 2021): 1548. http://dx.doi.org/10.3390/coatings11121548.
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Membrane fouling is a major issue that deteriorates the performance of membrane filtration systems. The electrically assisted membrane filtration process is proven to be effective for alleviating membrane fouling. In this study, we synthesized an electrically conductive membrane by incorporating multiwalled carbon nanotubes (MWCNTs) into polyvinyl chloride (PVC). The synthesized membranes have larger porosity than the PVC membrane (incorporating polyethylene glycol (PEG)), and thus possess much higher water flux under the same testing conditions. The initial and stable water fluxes are 2033 L/(m2·h) and 750 L/(m2·h), respectively, which are much higher than that of the pure PVC membrane. More importantly, the membrane has higher surface charge density and excellent electrical conductivity, but the surface hydrophilicity and toughness decreased with the addition of the MWCNTs. The 25 wt % MWCNTs/PVC composite membrane possesses suitable electrical conductivity of 0.128 S/m. The same membrane shows electro-enhanced antifouling performance during the antifouling test with yeast as a model foulant because the external electric field (−2 V) impulses a strong repulsion force while producing some micro bubbles to repel the foulant; thus, the membrane fouling is suppressed. In the current study, we develop a simple method to fabricate the electrically conductive membrane for application in the electrically assisted membrane filtration process.
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Zhang, Lanlan, Yingying Zhang, Qichong Zhao, Junhao Xu, and Jigang Xue. "Shape Effect Analysis of the Mechanical Properties of PVC-Coated Fabrics under Off-Axis Tension." Advances in Materials Science and Engineering 2020 (June 17, 2020): 1–12. http://dx.doi.org/10.1155/2020/9634120.
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This paper selects polyvinyl chloride- (PVC-) coated fabrics to study its off-axial tensile behaviors under different off-axis angles including 0°, 15°, 30°, 45°, 60°, 75°, and 90°. In the experiment, dumbbell-shaped and strip-shaped specimens are analyzed for shape effect. The variations in the strain distribution are studied by using digital image correlation (DIC) noncontact full-field measurement system. The shape and off-axis angle of specimens are analyzed to predict the influences of shape effect. The results show that the longitudinal strain and shear strain of the coated fabrics are obviously symmetrical to the off-axis direction. The shear strain distribution of the two kinds is basically the same, but the longitudinal strain fields are different. The off-axis tensile properties of the material are obviously anisotropic and nonlinear. The tensile testing curve of the specimens mainly consists of three stages: initial linear stage, deformation strengthening stage, and stress strengthening stage. At 0°, the tensile strength is the largest and the elongation at break is the smallest. In contrast, at 45°, the elongation at break is the highest and the tensile strength was the smallest. The properties under the other off-axis angles were between these two extremes.
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Wang, Tian, Matthew H. Pelletier, Nicky Bertollo, Alan Crosky, and William R. Walsh. "Cement-Implant Interface Contamination: Possible Reason of Inferior Clinical Outcomes for Rough Surface Cemented Stems." Open Orthopaedics Journal 7, no. 1 (June 28, 2013): 250–57. http://dx.doi.org/10.2174/1874325001307010250.
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Background: Shape-closed cemented implants rely on a stronger bond and have displayed inferior clinical outcomes when compared to force-closed designs. Implant contamination such as saline, bone marrow and blood prior to cement application has the potential to affect the cement-implant bond. The consequences of implant contamination were investigated in this study. Methods: Fifty Titanium alloy (Ti-6Al-4V) dowels were separated into ten groups based on surface roughness and contaminant, and then cemented in polyvinyl chloride tubes. Push-out testing was performed at 1mm per minute. The roughness of the dowel surface was measured before and after the testing. The dowel surface and cement mantel were analyzed using a Scanning Electron Microscopy (SEM) to determine the distribution and characteristics of any debris and contaminants on the surface. Results: Contaminants largely decreased stem-cement interfacial shear strength, especially for rough surfaces. Saline produced the greatest decrease, followed by blood. The effect of bone marrow was less pronounced and similar to that of oil. Increasing surface roughness increased the interfacial bonding strength, even with contaminants. There was a non-significant increase in mean bonding strength for smooth surfaces with bone marrow and oil contamination. SEM showed that contaminants influence the interfacial bond by different mechanisms. More debris was found on rough samples following testing. Conclusions: The results of this study underscore the importance of keeping an implant free from contamination, and suggest if contamination does occur, a saline rinse may further decrease the stability of an implant. The deleterious effects of contamination on rough surface cement bonding were considerable, and indicate that contamination at the time of surgery may, in part, contribute to inferior clinical outcomes for rough surfaced cemented stems.
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Godovalov, A. P., M. S. Stepanov, M. V. Yakovlev, E. E. Kobzarenko, and K. A. Batog. "DETERMINATION OF BIOFILM FORMING ACTIVITY OF MICROORGANISMS ON SYNTHETIC POLYMERIC MATERIALS." Russian Clinical Laboratory Diagnostics 64, no. 12 (December 15, 2019): 758–61. http://dx.doi.org/10.18821/0869-2084-2019-64-12-758-761.
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Microorganisms are able to form biofilms on surfaces of biotic and abiotic nature. In turn, in human biotopes there are optimal conditions for the implementation of biofilm-forming activity. Moreover, in medical practice, polymeric materials are often used for drainage or prosthetics, which can also be successfully colonized by bacteria. However, in laboratory practice, the formation of biofilms is usually evaluated on glass or polystyrene. The purpose of the study is to evaluate the methodological features of studying the biofilm-forming activity of microorganisms on the surface of synthetic polymeric materials. We used strains of Staphylococcus aureus ATCC 25923, Escherichia coli K-12, Candida albicans ATCC 10231, as well as synthetic polymeric materials - DentLight Flow light-curing composite material (nano-hybrid fluid composite; Russia), glass ionomer chemical curing Fuji 1 (Japan), cement for temporary fixation of orthopedic constructions TempBond NE (USA), acrylic, polyurethane and polyvinyl chloride. The formation of biofilms in flat-bottomed ELISA plates in this study was considered as a control group. If the polymer belonged to cold curing materials, sterile flat-bottomed tablets were used, the bottom of which was filled with a thin layer of plastic. After hardening of the plastic, biofilms were formed in the tablets. In the second series of experiments, hot cured materials cut into equal parts 5×5×1 mm in size were placed in the wells of a plate and again used to determine biofilm formation with subsequent coloring. To extract the dye, the pieces were transferred to a new plate to exclude the amount of film biomass formed on the walls of the plate wells. In both cases, cultivation was carried out at 37° C for 24-48 hours. The biomass of the film was stained with fuchsin. Statistical data processing was performed using t-Student criterion. For the threshold level of significance, the value p <0.05 was taken. It is established that the proposed options for determining biofilm forming ability are available and indicative. It was revealed that the same microorganisms have individual biofilm formation indicators for each polymer material. The light curing dental composite and polyvinyl chloride exhibit the more pronounced antiadhesive properties than cements and polyurethane. Up to date, most of the studies of biofilm formation have been carried out using glass or polystyrene, which, as a rule, are not used for the manufacture of prostheses, catheters, drains, etc., which makes it difficult to assess the true film-forming activity of microorganisms. The proposed methodological approaches, especially the second option for preparing testing samples, solve this problem. In general, the proposed approaches to testing biofilm-forming activity on polymers are very simple to implement and generally available. For an adequate study of the biofilms formation, it will be advisable to use polymer materials, directly used in medicine, rather than polystyrene tablets, the material of which is found exclusively in laboratory practice.
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Donovan, Erin P., Imad L. Al-Qadi, and Amara Loulizi. "Optimization of Tack Coat Application Rate for Geocomposite Membrane on Bridge Decks." Transportation Research Record: Journal of the Transportation Research Board 1740, no. 1 (January 2000): 143–50. http://dx.doi.org/10.3141/1740-18.
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One of the critical components of the U.S. civil infrastructure, bridges, has rapidly deteriorated in the past two decades and is in need of maintenance and rehabilitation. Geosynthetics may have the potential to provide a long-term solution to some of the problems that are present in these bridges, mainly, chloride intrusion into bridge decks. When installed properly, geosynthetics can act as both a moisture barrier and a stress absorption layer. However, the tack coat application rate is critical, as an excessive amount can cause eventual slippage, whereas too little may result in debonding. A new geocomposite membrane that comprises a low-modulus polyvinyl chloride layer sandwiched between two layers of nonwoven geotextile has recently been introduced for use in highway systems for water impermeation and strain energy absorption. A laboratory testing program was conducted to determine the optimum asphalt binder tack coat application rate that needs to be applied in the field. To accomplish this, a fixture was designed to allow the application of cyclic shear loading at the geocomposite membrane interface when used as an interlayer simulating a concrete bridge deck overlaid with the geocomposite membrane and a hot-mix asphalt (HMA) overlay. The study concluded that 1.75 kg of PG 64-22 binder per m2 is an optimum value to achieve excellent bonding and minimum slippage potential. For the upper surface in contact with a wearing surface mix, a tack coat application rate of 1.5 kg/m2 may be used. When the geocomposite membrane was included between concrete and HMA, failure occurred after a much larger number of applied loading cycles than the number of loading cycles to failure when the geocomposite was absent. In addition, the slope of shear stress versus the number of loading cycles at failure was much greater when the geocomposite was absent.
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Nowak, Karol, Jerzy Janiszewski, and Grzegorz Dombek. "The Possibilities to Reduce Arc Flash Exposure with Arc Fault Eliminators." Energies 14, no. 7 (March 31, 2021): 1927. http://dx.doi.org/10.3390/en14071927.
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This paper presents a method to limit the arc energy and hence the hazard risk category value according to IEEE 1584 by using a system of two oppositely connected multi-sectional thyristor branches. A test circuit for testing the effectiveness of a thyristor arc eliminator was designed and constructed. Arc ignition inside electrical switchgear can be a source of danger for technical personnel. The arc energy calculated according to the algorithms in IEEE 1584 can be significantly reduced by using multi-sectional arc eliminator MSAE. For the actual measuring object, the calculation of the hazardous arc flash zone and the hazard category was carried out for the system not equipped with an arc eliminator, and then the same was performed in a system with an arc eliminator. In parallel, the pressure inside the closed polyvinyl chloride (PVC) electrical box enclosure was measured and then compared with the calculated pressures that could occur during an arc fault. It was found that a Multi-Sectional Arc Eliminator (MSAE) effectively protects devices supplied from low voltage networks against the effects of short circuit or arc fault, such as the sudden increase of gas pressure inside the switchboard, which may cause it to break, significantly reduce the loss of electrode material, limit the spread of hot electrode material outside the switchgear, and also significantly reduces the energy of the electric arc.
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Ishida, Ai, Kyle Rochau, Kyle P. Findlay, Brandon Devero, Marco Duca, and Michael H. Stone. "Effects of an Initial Muscle Strength Level on Sports Performance Changes in Collegiate Soccer Players." Sports 8, no. 9 (September 15, 2020): 127. http://dx.doi.org/10.3390/sports8090127.
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The purposes of this study were to investigate effects of partial block periodized strength training on physical performance and to examine relationships between initial muscle strength measured with isometric mid-thigh pull (IMTP) and performance changes after 7 weeks of strength training. Seventeen collegiate male soccer players participated. Initial muscle strength was determined using IMTP while physical performance included 10 m and 20 m sprints and static vertical jump with a polyvinyl chloride pipe (SJ0), 20 kg barbell (SJ20), and barbell loaded to 40 kg bar (SJ40). Performance testing was performed at three points: before first week (baseline), fourth week (T1), and seventh week (T2). Statistically small to moderate changes were found from baseline to T2 in peak power (PP; p < 0.001, ES = 0.49), net impulse (NI; p < 0.001, ES = 0.49), peak velocity (PV; p < 0.001, ES = 0.62), allometrically scaled PP (PPa; p < 0.001, ES = 0.62) in SJ20 and jump height (JH) in SJ40 (p < 0.001, ES = 0.36). Moderate to large correlations were found between isometric peak force and the changes from baseline to T2 in SJ20 PP (p = 0.04, r = −0.49), SJ20 PF (p = 0.03, r = −0.52), PPa (p = 0.04, r = −0.50), and SJ20 allometrically scaled peak force (p = 0.04, r = −0.49). Properly structured strength training maximizes task-specific physical performance. Initial muscle strength negatively affects the magnitudes of adaptations to physical performance.
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Yao, Houqi, Yuezhao Pang, Xin Liu, and Jia Qu. "Experimental Study of the Dynamic and Static Compression Mechanical Properties of Closed-Cell PVC Foams." Polymers 14, no. 17 (August 27, 2022): 3522. http://dx.doi.org/10.3390/polym14173522.
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Closed-cell polyvinyl chloride foam (PVC) possesses many advantages, including its light weight, moisture protection, high specific strength, high specific stiffness, and low thermal conductivity, and is widely used as the core material in composite sandwich structures. It is increasingly used in fields with light weight requirements, such as shipbuilding and aerospace. Some of these structures can be affected by the action of dynamic loads during their lifespan, such as accidental or hostile blast loads as well as wind-loaded debris shocks. Examining the material properties of PVC foams under dynamic load is essential to predict the performance of foam sandwich designs. In this study, the compressive responses of a group of PVC foams with different densities were investigated under a broad range of quasi-static conditions and high strain rates using a universal testing machine and a lengthened Split Hopkinson press bar (SHPB) fabricated from titanium alloy. The results show that the mechanical properties of foam materials are related to their density and are strain rate-sensitive. The compressive strength and plateau stress of the foams were augmented with increased foam density. In the quasi-static strain rate range, the compressive strength of PVC foams at 10−1 s−1 was 27% higher than that at 10−4 s−1. With a strain rate of 1700 s−1, the strength was 107% higher than the quasi-static value at 10−4 s−1.
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Wróbel, M. S., A. P. Popov, A. V. Bykov, M. Kinnunen, M. Jędrzejewska-Szczerska, and V. V. Tuchin. "Multi-layered tissue head phantoms for noninvasive optical diagnostics." Journal of Innovative Optical Health Sciences 08, no. 03 (May 2015): 1541005. http://dx.doi.org/10.1142/s1793545815410059.
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Extensive research in the area of optical sensing for medical diagnostics requires development of tissue phantoms with optical properties similar to those of living human tissues. Development and improvement of in vivo optical measurement systems requires the use of stable tissue phantoms with known characteristics, which are mainly used for calibration of such systems and testing their performance over time. Optical and mechanical properties of phantoms depend on their purpose. Nevertheless, they must accurately simulate specific tissues they are supposed to mimic. Many tissues and organs including head possess a multi-layered structure, with specific optical properties of each layer. However, such a structure is not always addressed in the present-day phantoms. In this paper, we focus on the development of a plain-parallel multi-layered phantom with optical properties (reduced scattering coefficient [Formula: see text] and absorption coefficient μa) corresponding to the human head layers, such as skin, skull, and gray and white matter of the brain tissue. The phantom is intended for use in noninvasive diffuse near-infrared spectroscopy (NIRS) of human brain. Optical parameters of the fabricated phantoms are reconstructed using spectrophotometry and inverse adding-doubling calculation method. The results show that polyvinyl chloride-plastisol (PVCP) and zinc oxide ( ZnO ) nanoparticles are suitable materials for fabrication of tissue mimicking phantoms with controlled scattering properties. Good matching was found between optical properties of phantoms and the corresponding values found in the literature.
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Ting, Keh-Chuh, Modan Gill, and Orlando Garbin. "GC/MS Screening Method for Phthalate Esters in Children's Toys." Journal of AOAC INTERNATIONAL 92, no. 3 (May 1, 2009): 951–58. http://dx.doi.org/10.1093/jaoac/92.3.951.
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Abstract Phthalate esters are commonly added into polyvinyl chloride (PVC) as softeners to make the plastic material flexible. Phthalates are suspected cancer-causing agents and possible teratogens; they have been linked to liver and kidney damage, as well as the underdevelopment of reproductive organs in humans and animals. Public safety concerns about human exposure to phthalates are on the rise because they do not chemically bond to PVC and leach from the material over time. Following the lead of the European Union and Japan in restricting the use of certain phthalates, a legal limit of 0.1 in children's toys was established by the California State Legislature (AB-1108). In addition to its mission to protect public health and the environment from toxic harm, the California Department of Toxic Substances Control (DTSC) has been delegated the role of lead agency for consumer product safety. To support DTSC's Green Chemistry activities, the Environmental Chemistry Laboratory Mobile Laboratory Team has developed an on-site screening method to monitor phthalates in children's toys. This method is simple, fast, and effective, with ample sensitivity to quantify the 6 restricted phthalates in children's toys at 100 ppm (limit of quantitation = 100 g/g) which is 10 times lower than the legal allowable level of 0.1. Additionally, the method has a high throughput capability and enables testing of approximately 610 samples per day, depending on the complexity of the sample matrix and concentration. This method is designed to survey the 6 phthalates in children's toys and other consumer products for compliance with the threshold of 0.1 (1000 ppm).
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Majed, Masoud, Farideh Nejat, Mostafa El Khashab, Parvin Tajik, Mohammad Gharagozloo, Mahboubeh Baghban, and Adeleh Sajjadnia. "Risk factors for latex sensitization in young children with myelomeningocele." Journal of Neurosurgery: Pediatrics 4, no. 3 (September 2009): 285–88. http://dx.doi.org/10.3171/2009.4.peds08364.
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Object Patients with myelomeningoceles (MMCs) are at increased risk of latex allergy and sensitization. Number of surgeries and history of atopy are known risk factors. The object of this study was to evaluate the role of diagnostic procedures and nonsurgical treatments in latex sensitization in young patients with MMC. Methods Seventy-three children with MMC were included in the study. For each child a questionnaire was administered and serum determination of IgE was performed, and 62 children underwent skin prick tests (SPTs), 60 of which had reliable results. Multivariate logistic regression modeling was performed, using latex sensitization as the dependent variable. Results The mean age of the 73 patients was 3.8 years. The SPT results were positive in 30.6%, whereas results of testing for latex-specific IgE were positive in only 8.2%. In univariate analysis, history of untethering, barium enema, and number of clean intermittent catheterizations (CICs) per day were significantly associated with positive results on the SPT. Although the number of surgical procedures was significantly higher in patients who had shunts, no significant relationship between the presence of a shunt and latex sensitization was seen. Conclusions The young age of the patients in this study may account for the low prevalence of latex sensitization that was found. In young patients with MMC, the numbers of CICs per day, a history of untethering, circumcision, and a barium enema performed without latex-free equipment could be risk factors for latex sensitization. The use of latex-free gloves in all procedures performed in these cases, nonlatex polyvinyl chloride catheters in CIC, and ordinary nonballoon tips in barium enemas could decrease the risk of sensitization.
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Jalal, Mostafa, Anal K. Mukhopadhyay, and Zachary Grasley. "Design, manufacturing, and structural optimization of a composite float using particle swarm optimization and genetic algorithm." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, no. 7 (February 2, 2018): 1404–18. http://dx.doi.org/10.1177/1464420718755546.
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In the realm of laboratory experiments dealing with solutions, float is a dynamic part of the testing device to help monitor and measure the level change of the solution, which has a significant influence on the reliability of the data recorded. Thus, the material selection, design, and structural configuration of the float need to be optimized based on the test exposure conditions, temperature, test requirements, and setup limitations, while maintaining the manufacturing to be simple and cost-effective. In the present study, a composite float design, manufacturing, and optimization have been undertaken based on the performance constraints and setup requirements. For this purpose, readily available composites were taken into account in terms of density, temperature resistance, and alkali resistance, resulting in two design alternatives such as polyvinyl chloride and low-density polyethylene. Then, the structural configurations were considered and a performance-based design was implemented. In order to minimize the length of the composite float to make it fit well into the test setup, the design problem was formulated into a constrained optimization problem with four design scenarios and optimization was conducted using genetic algorithm and particle swarm optimization. The results obtained showed that the solutions of genetic algorithm and particle swarm optimization were comparable; however, those of particle swarm optimization proved to be more accurate in case of more complex design scenario, and also faster by two to three times. The manufacturing was conducted through plastic welding and heat shrink tubing and final assembly of linear variable differential transformer and steel weight. It was found that the composite float has a pretty sensitive and accurate performance and can reliably fit and be used in the experimental setup.
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Enriquez, Mike Louie C., Ronnie S. Concepcion II, R.-Jay S. Relano, Kate G. Francisco, Jonah Jahara G. Baun, Adrian Genevie G. Janairo, Renann G. Baldovino, Ryan Rhay P. Vicerra, Argel A. Bandala, and Elmer P. Dadios. "optIFnet: A Capacitive Antenna Dipole Indention-Flexure Predictive Model Optimized Using Hybrid Lichtenberg Algorithm and Neural Network." Journal of Advanced Computational Intelligence and Intelligent Informatics 27, no. 1 (January 20, 2023): 27–34. http://dx.doi.org/10.20965/jaciii.2023.p0027.
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In performing underground imaging surveying, applying a coating in the antenna dipole plates with robust and durable material to stay protected against rough road features is vital to consider. By doing this, the mechanical properties of the metallic antenna dipole can be improved and be shielded from deterioration. With that, this study has developed an indentation-flexure algorithm optimized using a hybrid Lichtenberg algorithm (LA) and artificial neural network (ANN) that can predict the indentation-flexure as a function of the coating material’s elastic modulus, Poisson ratio, and thickness as well as the load antenna weight. Acrylic, epoxy, nylon 101, high-density polyethylene, and polyvinyl chloride were chosen as the top five most popular coating materials. A 120° titanium cone indenter with a 0.5-inch-diameter, slightly rounded point, and a constant compressive force of 200 N in the center was employed to plot and use a nonlinear mechanical finite element analysis on an antenna dipole plate using SolidWorks. Nature-inspired and evolutionary metaheuristics such as African vultures, Lichtenberg, and gorilla troop optimization algorithm including genetic algorithm (GA) were employed as optimized models for the hardness indentation for capacitively coupled antenna dipoles. Based on the results, the hybrid LA-ANN solution with a hidden neurons of 3000 and a sigmoid activation function is the best performing model as it acquired a MSE score of 0.0061 in validation and 0.1478 in testing compare to the other model with 0.1610 for GA with 100 hidden neurons with sigmoid activation function. Thus, LA-ANN model is considered as the optIFnet as it exhibited the best prediction performance and fastest convergence among all optimizers used.
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Nagra, Uzair, Kashif Barkat, Muhammad U. Ashraf, and Maryam Shabbir. "Feasibility of Enhancing Skin Permeability of Acyclovir through Sterile Topical Lyophilized Wafer on Self-Dissolving Microneedle-Treated Skin." Dose-Response 20, no. 2 (April 2022): 155932582210975. http://dx.doi.org/10.1177/15593258221097594.
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Acyclovir is an antiviral drug that is frequently prescribed for the herpes virus. However, the drug requires frequent dosing due to limited bioavailability (10–26.7%). The rationale of the present study was to develop a self-dissolving microneedle system for local and systemic delivery of acyclovir using a topical lyophilized wafer on microneedle-treated skin to provide the drug at the site of infection. The microneedles prepared with hydroxypropyl methylcellulose (HPMC) (8% w/w) or HPMC (8% w/w)-polyvinyl pyrrolidone (PVP) (30% w/w) penetrated excised rat skin, showing sufficient mechanical strength and rapid polymer dissolution. The topical wafer was prepared with acyclovir (40% w/w; equivalent to 200 mg of drug), gelatin (10% w/w), mannitol (5% w/w), and sodium chloride (5% w/w). The uniform distribution of acyclovir within the wafer in an amorphous form was confirmed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). No polymer–drug interaction was evident in the lyophilized wafer as per Fourier transform infrared spectroscopy (FTIR) analysis. The wafer showed a sufficiently porous structure for rapid hydration as per scanning electron microscopy (SEM) analysis. During ex-vivo analysis, the skin was pre-treated with a self-dissolving microneedle array for 5 minutes, and the wafer was placed on this microporated-skin. Topical wafer provided ∼7–11 times higher skin concentration than the ID99 reported with a lower lag-time. Based on in-vivo testing, ∼2.58 µg/ml of Cmax was achieved in rabbit plasma during 24 hours’ study. Our findings suggest that the self-dissolving microneedle-assisted topical wafer, proposed for the first time, would be efficacious against the infection residing in the skin layer and for systemic therapy.
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Kato, Lilian Seiko, and Carlos A. Conte-Junior. "Safety of Plastic Food Packaging: The Challenges about Non-Intentionally Added Substances (NIAS) Discovery, Identification and Risk Assessment." Polymers 13, no. 13 (June 24, 2021): 2077. http://dx.doi.org/10.3390/polym13132077.
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Several food contact materials (FCMs) contain non-intentionally added substances (NIAS), and most of the substances that migrate from plastic food packaging are unknown. This review aimed to situate the main challenges involving unknown NIAS in plastic food packaging in terms of identification, migration tests, prediction, sample preparation, determination methods and risk assessment trials. Most studies have identified NIAS in plastic materials as polyurethane adhesives (PU), polyethylene terephthalate (PET), polyester coatings, polypropylene materials (PP), multilayers materials, plastic films, polyvinyl chloride (PVC), recycled materials, high-density polyethylene (HDPE) and low-density polyethylene (LDPE). Degradation products are almost the primary source of NIAS in plastic FCMs, most from antioxidants as Irganox 1010 and Irgafos 168, following by oligomers and side reaction products. The NIAS assessment in plastics FCMs is usually made by migration tests under worst-case conditions using food simulants. For predicted NIAS, targeted analytical methods are applied using GC-MS based methods for volatile NIAS and GC-MS and LC-MS based methods for semi- and non-volatile NIAS; non-targeted methods to analyze unknown NIAS in plastic FCMs are applied using GC and LC techniques combined with QTOF mass spectrometry (HRMS). In terms of NIAS risk assessment and prioritization, the threshold of toxicological concern (TTC) concept is the most applied tool for risk assessment. Bioassays with sensitive analytical techniques seem to be an efficient method to identify NIAS and their hazard to human exposure; the combination of genotoxicity testing with analytical chemistry could allow the Cramer class III TTC application to prioritize unknown NIAS. The scientific justification for implementing a molecular weight-based cut-off (<1000 Da) in the risk assessment of FCMs should be reevaluated. Although official guides and opinions are being issued on the subject, the whole chain’s alignment is needed, and more specific legislation on the steps to follow to get along with NIAS.
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Ul-Hamid, Anwar, Khaled Y. Soufi, Luai M. Al-Hadhrami, and Ahsan M. Shemsi. "Failure investigation of an underground low voltage XLPE insulated cable." Anti-Corrosion Methods and Materials 62, no. 5 (September 7, 2015): 281–87. http://dx.doi.org/10.1108/acmm-02-2014-1352.
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Purpose – This paper aims to determine the effect of exposure of underground electrical cables to chemically contaminated water. Design/methodology/approach – Visual inspection and photography were carried out to record the appearance of electrical cables. Failed and un-failed cable samples were collected and analyzed using light microscopy, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Sand and water samples were chemically tested for contaminants. Findings – Underground low-voltage 0.6/1-kV cross-linked polyethene insulated cables belonging to a chemical production plant suffered failure after four years of service. Excavation of the cable trench revealed that the cables were buried in sand polluted with chemically contaminated water. The cables were discolored and covered with corrosion deposits. Experimental results indicated that the cable insulation was heavily degraded and the outer jacket of polyvinyl chloride exhibited cracks that had penetrated through its thickness. Water and sand surrounding the cable were found to have high concentrations of ammonia. Mechanical testing of the cables indicated high values of stiffness that could contribute to the formation of cracks at the surface. Practical implications – It was concluded that contamination in the water had degraded the cable, resulting in the development of a network of branched cracks within the cable insulation through which water could permeate, leading to eventual failure of the cable. Accelerated degradation took place due to exposure to the contaminated environment, which promoted aging and brittleness. Continued exposure of electric cables to contamination would lead to power failures and plant shutdowns. Originality/value – This paper provides an account of a failure investigation of low-voltage electrical cable buried underground. It discusses the role of contaminated environment in the eventual failure of electrical cable due to corrosion. This information will be useful for plant engineers and project managers working in any industry that makes use of chemicals.
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Woldemariam, Abraham Mengesha, Walter O. Oyawa, and Timothy Nyomboi. "Structural Performance of uPVC Confined Concrete Equivalent Cylinders Under Axial Compression Loads." Buildings 9, no. 4 (April 14, 2019): 82. http://dx.doi.org/10.3390/buildings9040082.
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There is always a need for more durable, ductile, and robust materials for buildings, bridges, and other infrastructure due to the drawbacks of existing construction materials. Some of the drawbacks are the corrosion of steel, the brittle failure of concrete, and the performance instabilities that are caused when exposed to different environments. Thus, an innovative system is required to improve the performance and retain the integrity of structures in a harsh environment. To alleviate the situation, Un-plasticized polyvinyl chloride (uPVC) tubes are used as a confining material and their performance was experimentally evaluated by testing uPVC confined equivalent cylinders. Accordingly, unconfined and uPVC confined equivalent concrete cylinders for five different concrete classes, four types of uPVC tube sizes, and the aspect ratios of two (h/D = 2) were prepared and tested under axial compression loads. The result shows that the uPVC confinement increased the strength, ductility factor, and energy absorption in between 1.28–2.35, 1.84–15.3, and 11–243 times the unconfined levels, respectively. The confinement performed well for lower concrete classes and higher thickness to diameter ratios (2t/D). The post-peak behavior of the stress-strain curve was affected by the 2t/D ratio and the absolute value of the slope decreased as the 2t/D ratio increased. Additionally, the uPVC tube has shown several advantages, such as acting as a permanent formwork, protecting the concrete from chemical attacks, preventing the segregation of concrete, preventing peeling, and taking off concrete cover, decreasing the cross-section, and resulting in lighter sections. The uPVC confinement provided a remarkable improvement on the strength, ductility, energy absorption, and post-peak behavior of concrete. Therefore, uPVC tubes can be used as confining material for bridge piers, piles, electric poles, and highway signboards, where the fire risk is very small, though additional research is required on fire resistance mechanisms, such as wire-mesh reinforced mortar cover.
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BISHA, BLEDAR, ALMA PEREZ-MENDEZ, MICHELLE D. DANYLUK, and LAWRENCE D. GOODRIDGE. "Evaluation of Modified Moore Swabs and Continuous Flow Centrifugation for Concentration of Salmonella and Escherichia coli O157:H7 from Large Volumes of Water." Journal of Food Protection 74, no. 11 (November 1, 2011): 1934–37. http://dx.doi.org/10.4315/0362-028x.jfp-11-133.
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Modified Moore swabs (MMS; consisting of a polyvinyl chloride cartridge filled with gauze) capture microorganisms within the packed gauze as water flows through the cartridge, while continuous flow centrifugation (CFC) uses centrifugation to sediment the microorganisms while water continuously flows in the system. This study evaluated and compared the efficacy of MMS and CFC for concentration and subsequent detection of Escherichia coli O157:H7 and Salmonella from large volumes of water (10 liters). Water samples were spiked at levels of 101,102,103, and 104 CFU/100 ml with three-strain cocktails of either E. coli O157:H7 or Salmonella serovars, which had been previously transformed with a plasmid to express resistance to ampicillin as well as green, red, or cyan fluorescent proteins. Plating was performed before and after concentration on tryptic soy agar supplemented with ampicillin in order to quantitate the concentration efficiencies of each method. The two lowest spiking levels were also enriched in low volumes of tryptic soy broth supplemented with ampicillin followed by testing via lateral flow devices. Significant (P < 0.05) concentrations of initial levels of E. coli O157:H7 in the range of 0.7 to 1.0 and 1.2 to 1.4 log were achieved within approximately 35 min of processing time via MMS and CFC, respectively. Similarly, significant (P < 0.05) concentrations were also achieved for Salmonella with 0.9 to 1.2 and 1.2 to 1.4 log concentration for MMS and CFC, respectively. There were no statistical differences (P > 0.05) between the two concentration methods in their ability to concentrate either of the two target bacteria. Significantly (P < 0.05) more spiked samples were detected by lateral flow devices following concentration and enrichment than for nonconcentrated, enriched samples. It is concluded that both MMS and CFC have potential to be used to enhance the sensitivity of downstream bacterial detection methods used to test irrigation water for the presence of foodborne pathogens.