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Intaraksa, Parichat, Yositar Rudeekit, Pongsaks Siriyota e Thanawadee Leejarkpai. "Comparative Study of the Bio-Disintegration Behavior of Polylactic Acid under Laboratory and Pilot-Scale Composting Conditions". Advanced Materials Research 747 (agosto de 2013): 678–81. http://dx.doi.org/10.4028/www.scientific.net/amr.747.678.
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In recent years, compostable plastics have gained a great attention as green materials due to the problems of more plastic waste generated each year over the world. One attractive of compostable plastics is that after use they can be biodegraded by natural microorganisms in the composting process within a specified period of time. Degree and rate of disintegration during composting is an important requirement that is used to determine the compostability of these plastics. This research work studied and compared the disintegration behaviors of PLA laboratory and pilot-scale composting conditions according to ISO 20200:2004 and ISO 16929:2002. Finally, the results from the disintegration testing could be used to evaluate the compostability, biological properties and impacted of a plastic material on the fermentation of organic waste in the composting plant.
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Ferrero, Pablo. "Plastic waste to sustainable solutions: accelerating the biodegradation of syn-thetic plastics". Project Repository Journal 18, n.º 1 (23 de novembro de 2023): 60–62. http://dx.doi.org/10.54050/prj1820693.
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Plastic waste to sustainable solutions: accelerating the biodegradation of syn-thetic plastics BioICEP combines chemical and biological methods to turn fossil-based plastic waste into natural, biodegradable substitutes for the packaging and pharma industries. It combines three technologies that enhance, accelerate and increase the degradation of plastics to levels far beyond what is currently possible. A triple-action depolymerization system breaks down plastic waste through chemical disintegration processes, biocatalytic digestion and microbial consortia.
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Peng, Liang, Wenxue Du, Ganggang Bai, Lahuancairang, Shixiang Yuan, Juntao Li e Peng Feng. "Investigation of the Disintegration Characteristics of Neogene Mudstone at Different Burial Depths". Buildings 14, n.º 1 (15 de janeiro de 2024): 227. http://dx.doi.org/10.3390/buildings14010227.
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The complex structure of Neogene mudstone plays an important role in geological disasters. A close relationship exists between the mechanisms of mudstone landslides and the disintegration characteristics of rocks. Therefore, understanding the disintegration characteristics of Neogene mudstone at different depths is crucial for enhancing engineering safety and assessing landslide stability. This study employed Neogene mudstone from different depths to perform disintegration and plastic limit experiments and revealed the sliding mechanisms of landslides involving Neogene mudstone, providing theoretical support for mitigating mudstone geological disasters. Our results demonstrate that Neogene mudstone from different depths experiences varied stress conditions and pore water pressure due to geological actions, significantly affecting the disintegration characteristics. By ignoring the factors of the slip surface, the slake durability index of mudstone decreases with increasing burial depth, while the plasticity limit index tends to rise. The influence of groundwater, geo-stress, and pore structure on Neogene mudstones at different depths results in overall weak stability and disintegration. Landslide occurrences are likely connected to the mechanical properties of mudstones at the slip surface, where a low slake durability index and higher plasticity index make the mudstones prone to fracturing, breaking, and disintegrating once in contact with water.
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Zhu, Lei, Xin Jiang Song e Bao Ning Hong. "Analysis of Shallow Landslides Stability of Coal Measure Soil through Contact Elastic-Plastic FEM". Advanced Materials Research 243-249 (maio de 2011): 2076–83. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.2076.
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In order to reveal the mechanism of deformation, disintegration and failure of shallow landslides of coal measure soil, through contact elastic-plastic FEM with shear strength reduction, the paper analyzes shallow landslides stability, calculates shallow landslides safety factors, and reveals the mechanism of deformation, disintegration and failure of shallow landslide of coal measure soil. The results are shown as follows: during shallow landslides of coal measure soil, the displacement of sliding mass sliding along sliding surface, the plastic strain of sliding mass and sliding mass sliding state along sliding surface don’t change simultaneously; adopting contact elastic-plastic FEM algorithm may better reflect the actual state and sliding process of shallow landslides of coal measure soil. It can help faithfully reflect real situations of shallow landslides like deformation, disintegration and failure of shallow landslide of coal measure soil, and it may afford one method that can be used as a reference of the stability analysis, accurate evaluation and forecast of this type of landslide.
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Vaverková, Magdalena, František Toman, Dana Adamcová e Jana Kotovicová. "Study of the Biodegrability of Degradable/Biodegradable Plastic Material in a Controlled Composting Environment". Ecological Chemistry and Engineering S 19, n.º 3 (1 de janeiro de 2012): 347–58. http://dx.doi.org/10.2478/v10216-011-0025-8.
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Study of the Biodegrability of Degradable/Biodegradable Plastic Material in a Controlled Composting EnvironmentThe objective of this study was to determine the degrability/biodegradability of disposable plastic bags available on the market that are labeled as degradable/biodegradable and those certified as compost. The investigated materials were obtained from chain stores in the Czech Republic and Poland. Seven kinds of bags (commercially available) were used in this study. One of them was a disposable bag made of HDPE and mixed with totally degradable plastic additive (TDPA additive). Another was a disposable made of polyethylene with the addition of pro-oxidant additive (d2w additive). One was labeled as 100% degradable within various periods of time, from three months up to three years, and four were certified as compostable. The test was carried out in a controlled composting environment. The biodisintegration degree of the obtained pieces was evaluated following a modified version of ČSN EN 14806 Norm "Packaging - Preliminary evaluation of the disintegration of the packaging materials under simulated composting conditions in a laboratory scale test" and a modified version of ČSN EN ISO 20200 "Plastics - Determination of the degree of disintegration of plastic materials under simulated composting conditions in laboratory-scale test" (ISO 20200:2004). The emphasis was put on determination whether the bags are degradable/biodegradable or not.
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Eich, Andreas, Miriam Weber e Christian Lott. "Disintegration half-life of biodegradable plastic films on different marine beach sediments". PeerJ 9 (10 de agosto de 2021): e11981. http://dx.doi.org/10.7717/peerj.11981.
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The seafloor is considered the major sink for plastic debris in the world’s oceans. Biodegradable polymers are available on the market as a substitute for conventional plastic and could potentially end up in the same environment. To gain more insight into the effects of different sediments on the degradation rate of biodegradable plastic we performed two iterative seawater tank experiments. First, to test the effect of sediment grain size, film of Mater-Bi HF03V, a blend of thermoplastic starch and biodegradable polyesters, was placed on the surface of mud as well as on four different grain size fractions of beach sand. Disintegration half-life was shortest on mud (139 days) and increased with the grain size of the beach sediment fractions (63–250 µm: 296 days; 250–500 µm: 310 days; 500–1,000 µm: 438 days; >1,000 µm: 428 days). We assume that the higher surface-to-volume ratio in fine sediment compared to coarse sediment led to a higher bacterial abundance and thus to faster disintegration rates. In a follow-up experiment, the <500 µm fraction of sediment from four different beaches around Isola d’Elba, Italy, was used to test plastic disintegration as above. Additionally, polyhydroxybutyrate (PHB, MIREL P5001) was used as a positive control and high-density polyethylene (HD-PE) as a negative control. No disintegration was observed for HD-PE. Mater-Bi HF03V and PHB disintegrated significantly differently on sediment from different sites, with half-lives of Mater-Bi HF03V ranging from 72 to 368 days and of PHB from 112 to 215 days. Here, the half-life was shortest on slightly coarser sediment and at potentially anthropogenically impacted sites. We assume that the effect of the grain size on the disintegration rate was masked by other parameters influencing the microbial community and activity. Understanding the parameters driving biodegradation is key to reliably report the range of disintegration rates occurring under the various conditions in different ecosystems.
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Chong, Zhi Kai, Alexander Hofmann, Marie Haye, Sharon Wilson, Ihsanullah Sohoo e Kerstin Kuchta. "Lab-scale and on-field industrial composting of biodegradable plastic blends for packaging". Open Research Europe 2 (23 de agosto de 2022): 101. http://dx.doi.org/10.12688/openreseurope.14893.1.
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Background: The acceptance of compostable plastic packaging in industrial composting plants is not universal despite available certification for compostability due to the persistence of compostable plastic residues reported by some industrial plants. This study aims to better understand this discrepancy by comparing the disintegration rate of two compostable plastic blends designed for rigid packaging (polylactic acid based) and soft packaging (polybutylene succinate based) between a controlled lab-scale test and an on-field test in an industrial composting plant. Methods: The thermophilic lab-scale disintegration test was conducted according to ISO 20200 in triplicates for 4, 8 and 12 weeks while the on-field test was conducted by exposing duplicate test material in the compost pile of an industrial composting plant in northern Germany, for three weeks. The mass change of the remaining test material >2mm was used as an indicator of disintegration. Results: The rigid packaging blend (1 mm thickness) retained on average 76.4%, 59.0% and 55.7% of its mass after 4, 8 and 12 weeks respectively in the lab-scale test. After exposure to industrial composting on-field, the remaining mass was 97.2% and 99.5%. The soft packaging blend (109±9 µm sample thickness) retained on average 45.4%, 10.9% and 0.3% of its mass after 4, 8 and 12 weeks respectively and 94.0% and 93.8% after exposure to industrial composting on-field. Conclusions: The results show a substantial difference in disintegration rates between the lab-scale and the on-field test after three to four weeks. The difference between the tests that might contribute significantly to the differing disintegration rates is the composition of the composting substrate. Besides the design and characteristics of the packaging itself, the composting substrate and thermophilic composting duration of individual plants are important to determine the suitability of treating compostable plastic packaging in industrial composting plants as well as inform potential solutions.
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Mikhailov, S. V., e S. N. Danilov. "Helical-chip disintegration in the turning of plastic materials". Russian Engineering Research 33, n.º 3 (março de 2013): 176–78. http://dx.doi.org/10.3103/s1068798x13030131.
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Mukri, A. K., J. H. Tan, S. M. Tahir, M. S. Anuar e S. M. Yusoff. "Compaction behaviour of mannitol-cocoa powder mixtures and their resulting tablet strength and disintegration characteristics". Food Research 5, S1 (3 de janeiro de 2021): 182–87. http://dx.doi.org/10.26656/fr.2017.5(s1).038.
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Cocoa powder is an important ingredient in the confectionery industry and, mannitol is an alternative sugar alcohol. In this work, mannitol powder was mixed with cocoa powder and compacted into tablet form via the uniaxial die compaction process. The frictional, compaction, tablet mechanical and disintegration properties were studied due to their importance in characterizing the behaviour of the tablets during processing and its final product characteristics at varying mannitol contents. The composition of mannitol in the mannitol-cocoa tablet varied at 95% w/w, 50% w/w and 5% w/w, while pure 100% w/w mannitol and cocoa tablets were set as controls. The compaction pressures used in making the tablets varied at 37.67 MPa, 75.34 MPa, 113.01 MPa, 150.68 MPa and 188.35 MPa. The compaction behaviour of the powder during the compaction process was evaluated using the plastic work and the maximum ejection stress values. The tablet strength was determined using the tensile strength method and tablet disintegration study was also conducted. The results showed that the increase in the compaction pressures increased the plastic work, maximum ejection pressure, tablet strength and also its disintegration time. The tablet formed having 95% w/w mannitol composition exhibited the highest plastic work value of 10.32±0.01 J, highest maximum ejection pressure value of 4.4±0.06 MPa, highest tensile strength value of 1.06±0.04 MPa and shortest disintegration time of 171±51 s amongst the three different mannitol compositions studied. Meanwhile, the effects of mannitol composition in the tablet on these observed responses were also dependent upon the compaction pressures used during tablet formation. In conclusion, the addition of mannitol improved the tablet strength and shorten the disintegration time in the experimental range employed in this study.
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Tuong, Thi Nguyet Anh, Thi Thuy Le, Hoang Linh Doan, Tien Dat Nguyen, Ngoc Diep Nguyen, Xuan Quang Chu, Hung Thuan Tran e hao Yen Linh Dang. "Evaluation of the disintegrability of eco-friendly packaging under laboratory and pilot-scale composting conditions". Ministry of Science and Technology, Vietnam 65, n.º 10DB (25 de outubro de 2023): 67–72. http://dx.doi.org/10.31276/vjst.65(10db).67-72.
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The growing production demand and promising applications of biodegradable plastic have spurred interest in assessing the biodegradability of this material. Disintegration is the first stage of the biodegradation process and therefore it affects the most important on the biodegradability of materials. This research focuses on evaluating and comparing the disintegration ability of eco-friendly packaging, which is being produced and commonly consumed in Vietnam, under industrial composting conditions at laboratory scale according to TCVN 12409:2020 standard and pilot scale according to TCVN 12408:2020 standard. The variations in temperature, humidity, pH, and visual appearance were monitored during the composting process. The results showed that the disintegration behaviours of eco-friendly packaging are similar at both scales. The disintegration rate of eco-friendly packaging at both testing scales reached over 90% after 84 days.
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Chen, Qing Feng, Zhong Hui Chen, Ning Ma, Wei Zhang e Hui Li. "The Zonal Disintegration Law within Coal in Front of Working Face in Deep Coal Mine". Applied Mechanics and Materials 353-356 (agosto de 2013): 1082–89. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.1082.
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The mining coal in the front of long wall face consists of elastic zone, plastic zone and fracture zone. Based on the research of zonaldisintegration of surrounding rock mass in deep tunnel, the zonal disintegration phenomenon of deep coal mine was analyzed by using the theoretical analysis method. On the basis of the Griffith theory, the internal and external boundary formulas of fracture zone and the mechanical criteria of zonal disintegration were obtained. The research shows that the essence of zonal disintegration is the tensile failure and brittle tension crack failure under the abutment pressure, the main influence factors of the width variation of fracture zone are original rock stress and un-axial tensile strength of coal.
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Filonenko, M. Yu, e S. B. Piliaieva. "STUDY OF THE EFFECT OF PRELIMINARY PLASTIC DEFORMATION IN THE PROCESS OF DISSOLUTION DURING TEMPERING OF LOW-CARBON AND BORON-CONTAINING ALLOYS". Science and Transport Progress, n.º 29 (25 de outubro de 2009): 202–5. http://dx.doi.org/10.15802/stp2009/14149.
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In the paper the influence of preliminary deformation on disintegration of martensite in boron-containing and carbonic alloy is explored. It is shown that at the small degree of deformation (7 per cent) both in low-carbonic and boron-containing alloys the process of martensite disintegration takes place less intensively. The increase of degree of preliminary deformation in a boron-containing alloy is instrumental in more even distribution of boron-cementite particles appearing as a result of martensite disintegration.
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Maragkaki, Angeliki, Nikitas G. Malliaros, Ioannis Sampathianakis, Theofanis Lolos, Christos Tsompanidis e Thrassyvoulos Manios. "Evaluation of Biodegradability of Polylactic Acid and Compostable Bags from Food Waste under Industrial Composting". Sustainability 15, n.º 22 (15 de novembro de 2023): 15963. http://dx.doi.org/10.3390/su152215963.
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To reduce plastic pollution, biodegradable plastics have been introduced to the market to replace petroleum-based plastics. This work investigates the biodegradation/disintegration of pure poly-L-lactic acid (PLLAB2B), composed of food waste (FW), and PLLAB2B bags, under industrial composting conditions, in order to determine whether they are compostable and to examine compost quality. In order to study the biodegradation, pure PLLAB2B was degraded in laboratory conditions and bag samples were put into simulation systems using windrow technology. Phytotoxicity tests were carried out for every compost sample and high germination values were found (97–103.8%). The pure PLLA reached an average biodegradation value of 100.2 ± 3.7% and a disintegration value of 100.0 ± 0.0%, resulting in biodegradable mature compost. After a seven week composting trial, the bag samples had fully decomposed. The samples had no influence on compost characteristics and there were no visually perceptible changes to the compost. Therefore, we suggest that food waste bioplastic can be used as a potential eco-material for compostable bags, one which could be used in industrial composting units and which offers degradable active materials with low environmental impact.
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Bryson, Emily, Lisa Bricknell, Ryan Kift e Amie Anastasi. "Disintegration of certified compostable plastic bags in outdoor household composting conditions". Waste Management 190 (dezembro de 2024): 654–65. http://dx.doi.org/10.1016/j.wasman.2024.10.028.
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Kuznetsova, Olga V., Sergey N. Shtykov e Andrei R. Timerbaev. "Mass Spectrometry Insight for Assessing the Destiny of Plastics in Seawater". Polymers 15, n.º 6 (19 de março de 2023): 1523. http://dx.doi.org/10.3390/polym15061523.
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Plastic pollution has become an increasingly serious environmental issue that requires using reliable analytical tools to unravel the transformations of primary plastics exposed to the marine environment. Here, we evaluated the performance of the isotope ratio mass spectrometry (IRMS) technique for identifying the origin of polymer material contaminating seawater and monitoring the compositional alterations due to its chemical degradation. Of twenty-six plastic specimens available as consumer products or collected from the Mediterranean Sea, five plastics were shown to originate from biobased polymeric materials. Natural abundance carbon and hydrogen isotope measurements revealed that biopolymers incline to substantial chemical transformation upon a prolonged exposure to seawater and sunlight irradiation. To assess the seawater-mediated aging that leads to the release of micro/nano fragments from plastic products, we propose to use microfiltration. Using this non-destructive separation technique as a front end to IRMS, the fragmentation of plastics (at the level of up to 0.5% of the total mass for plant-derived polymers) was recorded after a 3-month exposure and the rate and extent of disintegration were found to be substantially different for the different classes of polymers. Another potential impact of plastics on the environment is that toxic metals are adsorbed on their surface from the seashore water. We addressed this issue by using inductively coupled mass spectrometry after nitric acid leaching and found that several metals occur in the range of 0.1–90 µg per g on naturally aged plastics and accumulate at even higher levels (up to 10 mg g−1) on pristine plastics laboratory-aged in contaminated seawater. This study measured the degradation degree of different polymer types in seawater, filling in the gaps in our knowledge about plastic pollution and providing a useful methodology and important reference data for future research.
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Astuti, Astuti, Anthony Costa, Akbar Teguh Prakoso, Irsyadi Yani e Yulia Resti. "PREDICTION OF PLASTIC-TYPE FOR SORTING SYSTEM USING DECISION TREE MODEL". Indonesian Journal of Engineering and Science 4, n.º 1 (10 de março de 2023): 075–81. http://dx.doi.org/10.51630/ijes.v4i1.86.
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Plastic is the most widely used inorganic material globally, but its hundred-year disintegration time can harm the environment. Polyethylene Terephthalate (PET/PETE), High-Density Polyethylene (HDPE), and Polypropylene are all commonly used plastics that have the potential to become waste (PP). An essential first step in the recycling process is sorting out plastic waste. A low-cost automated plastic sorting system can be developed by using digital image data in the red, green, and blue (RGB) color space as the dataset and predicting the type using learning datasets. This paper proposes the Decision Tree model to predict the three plastic-type sorting systems based on discretizing predictor variables into two and three categories. The resampling method of k-fold cross-validation with ten folds for less biased. Discretization of the predictor variables into three categories informs that the proposed decision tree model has higher performance compared to the two categories with an accuracy of 81.93 %, a recall-micro of 72.89 %, a recall-macro of 72.30 %, a specificity-micro of 86.45%, and the specificity-macro of 86.51%, respectively. The micro is determined by the number of decisions made for each object. In comparison, the macro is calculated based on the average decision made by each class.
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Chen, Xuguang, Yuan Wang, Yu Mei e Xin Zhang. "Numerical Simulation on Zonal Disintegration in Deep Surrounding Rock Mass". Scientific World Journal 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/379326.
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Zonal disintegration have been discovered in many underground tunnels with the increasing of embedded depth. The formation mechanism of such phenomenon is difficult to explain under the framework of traditional rock mechanics, and the fractured shape and forming conditions are unclear. The numerical simulation was carried out to research the generating condition and forming process of zonal disintegration. Via comparing the results with the geomechanical model test, the zonal disintegration phenomenon was confirmed and its mechanism is revealed. It is found to be the result of circular fracture which develops within surrounding rock mass under the high geostress. The fractured shape of zonal disintegration was determined, and the radii of the fractured zones were found to fulfill the relationship of geometric progression. The numerical results were in accordance with the model test findings. The mechanism of the zonal disintegration was revealed by theoretical analysis based on fracture mechanics. The fractured zones are reportedly circular and concentric to the cavern. Each fracture zone ruptured at the elastic-plastic boundary of the surrounding rocks and then coalesced into the circular form. The geometric progression ratio was found to be related to the mechanical parameters and the ground stress of the surrounding rocks.
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Yu, Yuan-xiang, Zhi-xun Xie e Bao-ping Chen. "Space-Time Evolution Laws of Zonal Disintegration in Deep Underground Caves Based on Coordination Deformation between the Bolt Body and Surrounding Rock". Advances in Civil Engineering 2021 (5 de maio de 2021): 1–14. http://dx.doi.org/10.1155/2021/8818218.
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Zonal disintegration refers to the special phenomenon whereby fractured zones and intact zones appear alternately in deep-buried surrounding rocks under high stress conditions, which are different from that of the shallow rock mass. Because the divisional rupture law in engineering practice is closely related to the force characteristics of the bolt body, this paper analyzed stress distribution rules of the same bolt body at different times and that of different bolt bodies at the same time in the case of zonal disintegration based on coordination deformation between the bolt body and surrounding rock. The nonlinear rheological mechanics model of rock mass on the elastic-plastic interface under the maximum support pressure was established. It puts forward the theoretical calculation formula about the mechanics criterion and breakdown moment of the zonal disintegration. Using the mechanics model of interaction between a bolt and the surrounding rock, the distribution locations along the bolt body of the anchor neutral points and its maximum axial forces were discussed with the multiple theoretical neutral points. Furthermore, the location and width of each fracture zone were back analyzed. The results show that the rock mass on the elastic-plastic interface of the surrounding rock has a significant creep effect after the excavation of the deep underground cave. While maximum deviator stress of the rock mass is more than its long-term strength, the rock mass will fracture along a radial direction and come into the fractured zone. The multiple redistribution of the surrounding rock stress will generate alternate distribution phenomena of the fractured zone and intact zone. Meanwhile, the distribution regularity of the peaks and troughs interval of the displacement of surrounding rock leads to multiple neutral points along the anchor length direction. The computed results of zonal disintegration through the back analysis can reflect the actual space-time evolution laws of zonal disintegration in deep underground caves.
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Chong, Zhi Kai, Alexander Hofmann, Marie Haye, Sharon Wilson, Ihsanullah Sohoo, Ayah Alassali e Kerstin Kuchta. "Lab-scale and on-field industrial composting of biodegradable plastic blends for packaging". Open Research Europe 2 (13 de setembro de 2023): 101. http://dx.doi.org/10.12688/openreseurope.14893.2.
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Background: The acceptance of compostable plastic packaging in industrial composting plants is not universal despite available certification due to the persistence of plastic residues after composting. To better understand this discrepancy, this study compared the disintegration rates of two blends designed for rigid packaging (polylactic acid based) and soft packaging (polybutylene succinate based) in lab-scale composting tests and in an industrial composting plant. Methods: A lab-scale composting test was conducted in triplicates according to ISO 20200 for 4, 8 and 12 weeks to check the disintegration potential of the blends. Duplicate test material were then exposed in the compost pile of an industrial composting plant for a duration of 3 weeks and compared with a supplementary lab-scale test of the same duration. Results: The rigid packaging samples (1 mm thickness) retained on average 76.4%, 59.0% and 55.7% of its mass after 4, 8 and 12 weeks respectively in the lab-scale. In the plant, the remaining mass was 97.2% and 99.5%, much higher compared to the average of 68.9% after 3 weeks in the supplementary lab-scale test. The soft packaging samples (109±9 µm sample thickness) retained on average 45.4%, 10.9% and 0.3% of its mass after 4, 8 and 12 weeks respectively in the lab-scale. In the plant, a high remaining mass was also observed (94.0% and 93.8%). The supplementary lab-scale test showed similar remaining mass but higher fragmentation after 3 weeks. Conclusions: The results show that the samples achieved significant disintegration in the lab-scale but not in the plant. The difference between the tests that might further contribute to the differing degradation rates is the composition and heterogeneity of the composting substrate. Therefore, the substrate composition and thermophilic composting duration of individual plants are important considerations to determine the suitability of treating compostable plastic in real-world conditions.
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Chong, Zhi Kai, Alexander Hofmann, Marie Haye, Sharon Wilson, Ihsanullah Sohoo, Ayah Alassali e Kerstin Kuchta. "Lab-scale and full-scale industrial composting of biodegradable plastic blends for packaging". Open Research Europe 2 (22 de janeiro de 2024): 101. http://dx.doi.org/10.12688/openreseurope.14893.3.
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Background The acceptance of compostable plastic packaging in industrial composting plants is not universal despite available certification due to the persistence of plastic residues after composting. To better understand this discrepancy, this study compared the disintegration rates of two blends designed for rigid packaging (polylactic acid based) and soft packaging (polybutylene succinate based) in lab-scale composting tests and in an industrial composting plant. Methods A lab-scale composting test was conducted in triplicates according to ISO 20200 for 4, 8 and 12 weeks to check the disintegration potential of the blends. Duplicate test material were then exposed in the compost pile of an industrial composting plant for a duration of 3 weeks and compared with a supplementary lab-scale test of the same duration. Results The rigid packaging samples (1 mm thickness) retained on average 76.4%, 59.0% and 55.7% of its mass after 4, 8 and 12 weeks respectively in the lab-scale. In the plant, the average remaining mass was 98.3%, much higher compared to the average of 68.9% after 3 weeks in the supplementary lab-scale test. The soft packaging samples (109±9 µm sample thickness) retained on average 45.4%, 10.9% and 0.3% of its mass after 4, 8 and 12 weeks respectively in the lab-scale. In the plant, a high average remaining mass was also observed (93.9%). The supplementary lab-scale test showed similar remaining mass but higher fragmentation after 3 weeks. Conclusions The results show that the samples achieved significant disintegration in the lab-scale but not in the plant. The difference between the tests that might further contribute to the differing degradation rates is the composition and heterogeneity of the composting substrate. Therefore, the substrate composition and thermophilic composting duration of individual plants are important considerations to determine the suitability of treating compostable plastic in real-world conditions.
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Zhao, Yingting, Heather Smyth, Keyu Tao, Robert Henry e Robert Gilbert. "Starch Molecular Structural Features and Volatile Compounds Affecting the Sensory Properties of Polished Australian Wild Rice". Foods 11, n.º 4 (10 de fevereiro de 2022): 511. http://dx.doi.org/10.3390/foods11040511.
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Cooked high-amylose rices, such as Australian wild rice (AWR) varieties, have slower digestion rates, which is nutritionally advantageous, but may have inferior eating qualities. Here, a comparison is made between sensory and starch molecular fine structure properties, and volatile compounds, of polished AWR varieties and some commercial rices (CRs). Starch structural parameters for amylopectin (Ap) and amylose (Am) were obtained using fluorophore-assisted capillary electrophoresis and size-exclusion chromatography. Volatile compounds were putatively using headspace solid-phase microextraction with gas chromatography-mass spectrometry. Sensory properties were evaluated by a trained panel. AWR had a disintegration texture similar to that of Doongara rice, while AWR had a resinous, plastic aroma different from those of commercial rice varieties. Disintegration texture was affected by the amounts of Ap short chains, resinous aroma by 2-heptenal, nonadecane, 2h-pyran, tetrahydro-2-(12-pentadecynyloxy)-, and estra-1,3,5(10)-trien-17β-ol, and plastic aroma by 2-myristynoyl pantetheine, cis-7-hexadecenoic acid, and estra-1,3,5(10)-trien-17β-ol. These findings suggest that sensory properties and starch structures of AWR varieties support their potential for commercialization.
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Vu, Minh Duc, Thanh Liem Nguyen, Thi Kim Chi Dang e Chau Giang Nguyen. "Evaluation of the biodegradability of poly (butylene adipate-co-terephthalate) and cassava starch films in municipal compost under controlled conditions by analysis of evolved carbon dioxide". Ministry of Science and Technology, Vietnam 65, n.º 8 (25 de agosto de 2023): 50–55. http://dx.doi.org/10.31276/vjst.65(8).50-55.
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Plastic waste pollution is a major environmental issue all over the world, with Vietnam ranking among the ten most polluted countries. As a result, it is critical that research aims to reduce pollution levels from this plastic waste resource through the fabrication and application of biodegradable polymers to replace traditional plastics. In this study, plastics blend film based on cassava starch/poly(butylene adipate-co-terephthalate) (TPS/PBAT) (ratio of 40/60) was fabricated in a reactive twin screw extruder. Testing methods following the ASTM 6400 standard were used to evaluate the biodegradability of the film based on the TPS/PBAT blend shown that under controlled aerobic composting conditions (temperature of 58°C and humidity of 55%), the biodegradation rate of the film, calculated according to the amount of CO2 produced, reached of 91% after 155 days, and the disintegration degree of 96% after 53 days. The rate of bean and cucumber germination on the resulting compost demonstrates satisfactory terrestrial safety. The results of this study confirmed that TPS/PBAT film is a highly compostable material that can be used to improve the biodegradability of products like munch films, supermarket bags, seedling bags, and garbage bags.
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Post, Wouter, Lambertus J. Kuijpers, Martin Zijlstra, Maarten van der Zee e Karin Molenveld. "Effect of Mineral Fillers on the Mechanical Properties of Commercially Available Biodegradable Polymers". Polymers 13, n.º 3 (27 de janeiro de 2021): 394. http://dx.doi.org/10.3390/polym13030394.
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In the successful transition towards a circular materials economy, the implementation of biobased and biodegradable plastics is a major prerequisite. To prevent the accumulation of plastic material in the open environment, plastic products should be both recyclable and biodegradable. Research and development actions in the past few decades have led to the commercial availability of a number of polymers that fulfil both end-of-life routes. However, these biobased and biodegradable polymers typically have mechanical properties that are not on par with the non-biodegradable plastic products they intend to replace. This can be improved using particulate mineral fillers such as talc, calcium carbonate, kaolin, and mica. This study shows that composites thereof with polybutylene succinate (PBS), polyhydroxybutyrate-hexanoate (PHBH), polybutylene succinate adipate (PBSA), and polybutylene adipate terephthalate (PBAT) as matrix polymers result in plastic materials with mechanical properties ranging from tough elastic towards strong and rigid. It is demonstrated that the balance between the Young’s modulus and the impact resistance for this set of polymer composites is subtle, but a select number of investigated compositions yield a combination of industrially relevant mechanical characteristics. Finally, it is shown that the inclusion of mineral fillers into biodegradable polymers does not negate the microbial disintegration of these polymers, although the nature of the filler does affect the biodegradation rate of the matrix polymer.
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Malińska, Krystyna, Agnieszka Pudełko, Przemysław Postawa, Tomasz Stachowiak e Danuta Dróżdż. "Performance of Biodegradable Biochar-Added and Bio-Based Plastic Clips for Growing Tomatoes". Materials 15, n.º 20 (16 de outubro de 2022): 7205. http://dx.doi.org/10.3390/ma15207205.
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Increasing quantities of waste from using conventional plastic in agriculture and horticulture is one of the most pressing issues nowadays. Conventional plastic accessories (e.g., mulching films, clips, pots, strings, etc.) are typically fossil-derived, non-biodegradable and difficult to recycle after their use. Therefore, there is a need for biodegradable and bio-based alternatives with similar properties to conventional plastics, which can be disposed of through degradation in water, soil or compost under specific conditions. This work investigated the properties and the performance of biodegradable biochar-added and bio-based stem and arch support clips. In addition, the investigated clips were composted with tomato residues during 16 week laboratory composting. The scope of this work included: (1) the production of stem and arch support clips in a pilot installation using injection molding technology, (2) an analysis of their chemical composition, biodegradability, disintegration and phytotoxicity, (3) an evaluation of their performance in the greenhouse cultivation of tomatoes and (4) an evaluation of the composting of the clips with on-farm organic waste as an end-of-waste management method. The stem support clips during industrial composting (58 °C) degraded at 100% after 20 weeks, whereas during home composting (30 °C) the degradation was slow, and after 48 weeks the maximum weight loss was 5.43%. Disintegration during industrial composting resulted in 100% fragmentation into particles with sizes less than 2 mm. Phytotoxicity tests demonstrated that the substrates after industrial and home composting did not have a negative effect on the growth of the test plants (i.e., mustard, wheat, cuckooflower). The biochar-added stem support clips proved to be satisfactory alternatives to conventional non-biodegradable, fossil-derived clips and can be disposed of through composting. However, more work is needed to determine the optimal conditions for composting to ensure rapid degradation of the clips in relevant environments.
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Yang, Peiju, Shurong Zhang e Changyou Liu. "Study on Shear Failure Process and Zonal Disintegration Mechanism of Roadway under High Ground Stress: A Numerical Simulation via a Strain-Softening Plastic Model and the Discrete Element Method". Applied Sciences 14, n.º 10 (12 de maio de 2024): 4106. http://dx.doi.org/10.3390/app14104106.
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Fracture expansion in rock masses can be observed by monitoring the break of contacts between the bounding particles via the discrete element method. The latter’s realization in this study via the PFC2D program tracked the evolution process of the zonal disintegration in an exemplary roadway-surrounding rock affected by mining. Besides, the damage evolution pattern in a high-stress soft rock roadway was simulated by the FLAC2D program using a strain-softening plastic model, revealing the effects of rock mass strength, stress state, and anchor support on the zonal disintegration of the roadway. Numerical simulation results show that in a roadway with high-level stress, the obvious fractures spread from the roadway surface to the depth of the surrounding rock along a series of geometric planes and cut the surrounding rock into rock mass blocks. Under high crustal stress, conjugate shear fractures occur near the roadway surfaces and form a closed-loop fractured zone after intersecting the conjugate fracture faces. The closed fractured zone becomes a free face, from which conjugate shear fractures develop, forming new closed fractured zones in the deep surrounding rock. By repeatedly generating the closed fracture zones, a fracture network appears in the roadway-surrounding rock. The development of zonal disintegration of roadway-surrounding rock mainly depends on the rock mass strength and its stress state. Zonal disintegration only occurs when the crustal stress of the roadway-surrounding rock exceeds its strength. When the horizontal stress is low and the vertical stress exceeds the rock mass strength, zonal disintegration only occurs on two sides of the roadway. When the vertical stress is low and the horizontal stress exceeds the rock’s mass strength, it only appears on the roof and floor. When the values of cohesion, internal friction angle, and tensile strength are reduced in the same proportion, cohesion has the greatest impact on the expansion of the zonal disintegration zone, followed by the internal friction angle, while the tensile strength effect is the least. In anchor-supported roadways undergoing zonal disintegration processes, the intact zone blocks slide relatively along the fracture surface during the process of loosening and deformation of the surrounding rock, making the anchor rods susceptible to tensile, shear, and bending actions.
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Rai, Meera, Gaurav Pant, Kumud Pant, Becky N. Aloo, Gaurav Kumar, Harikesh Bahadur Singh e Vishal Tripathi. "Microplastic Pollution in Terrestrial Ecosystems and Its Interaction with Other Soil Pollutants: A Potential Threat to Soil Ecosystem Sustainability". Resources 12, n.º 6 (27 de maio de 2023): 67. http://dx.doi.org/10.3390/resources12060067.
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The production and disposal of plastics have become significant concerns for the sustainability of the planet. During the past 75 years, around 80% of plastic waste has either ended up in landfills or been released into the environment. Plastic debris released into the environment breaks down into smaller particles through fragmentation, weathering, and other disintegration processes, generating microplastics (plastic particles ≤ 5 mm in size). Although marine and aquatic ecosystems have been the primary focus of microplastic pollution research, a growing body of evidence suggests that terrestrial ecosystems are equally at risk. Microplastic contamination has been reported in various terrestrial environments from several sources such as plastics mulch, pharmaceuticals and cosmetics, tire abrasions (tire wear particles), textiles industries (microfibers), sewage sludge, and plastic dumping. Recent studies suggest that the soil has become a significant sink for pollutants released into terrestrial ecosystems and is often contaminated with a mixture of organic and inorganic pollutants. This has gradually caused adverse impacts on soil health and fertility by affecting soil pH, porosity, water-holding capacity, and soil microbial enzymatic activities. Microplastics can interact with the co-existing pollutants of the environments by adsorbing the contaminants onto their surfaces through various intermolecular forces, including electrostatic, hydrophobic, non-covalent, partition effects, van der Waals forces, and microporous filling mechanisms. This subsequently delays the degradation process of existing contaminants, thereby affecting the soil and various ecological activities of the ecosystem. Thus, the present article aims to elucidate the deleterious impact of microplastics and their interactions with other pollutants in the terrestrial ecosystem. This review also addresses the impact of microplastics in disrupting the soil sustainability of the planet.
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Engelhart, M., M. Krüger, J. Kopp e N. Dichtl. "Effects of disintegration on anaerobic degradation of sewage excess sludge in downflow stationary fixed film digesters". Water Science and Technology 41, n.º 3 (1 de fevereiro de 2000): 171–79. http://dx.doi.org/10.2166/wst.2000.0069.
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The effects of mechanical disintegration on anaerobic digestibility of sewage excess sludge in downflow stationary fixed film (DSFF) digesters were investigated on laboratory scale. Mechanical pretreatment using a high pressure homogenizer led to significantly enhanced concentrations of soluble proteins and carbohydrates in the feed sludge. Using DSFF digesters with two different tubular plastic media as support material it was shown that a stable digestion process could be achieved at hydraulic retention times (HRT) down to 5 days. Compared to conventional digesters at 10 d and 15 d HRT respectively, the degradation of volatile solids was enhanced up to 25%, also resulting in a higher specific biogas production. Further investigations on degradation of soluble proteins and carbohydrates showed that a slowly degradable fraction of carbohydrates was released via disintegration. Using the distribution of chain length and the concentrations of volatile fatty acids as process parameters, the dependability on the HRT and the degree of disintegration (the release of soluble COD) predominated the effects of specific surface area of the support media.
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Deocaris, Chester C., Jayson O. Allosada, Lorraine T. Ardiente, Louie Glenn G. Bitang, Christine L. Dulohan, John Kenneth I. Lapuz, Lyra M. Padilla, Vincent Paulo Ramos e Jan Bernel P. Padolina. "Occurrence of microplastic fragments in the Pasig River". H2Open Journal 2, n.º 1 (1 de janeiro de 2019): 92–100. http://dx.doi.org/10.2166/h2oj.2019.001.
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Abstract Microplastics are plastic fragments with dimensions of less than 5 mm. These materials are formed within bodies of water by the forces shearing on the large plastics. Ultraviolet light from sunlight also degrades plastic materials causing discoloration and disintegration into smaller, micro- or even nano-sized particles. This study reports the isolation of microplastic fragments from the Pasig River within the vicinity of the Polytechnic University of the Philippines. The collection of floating particulates was done by sieving the river water (flow rate = 0.31 m s−1) through a 0.35 mm mesh for 10 minutes. Through this method, 25.7 m3 of river water was sieved over three samplings. Microplastics were isolated through a series of peroxide oxidation and sedimentation methods. All microplastic fragments were viewed and photographed under a compound microscope (40–100× magnification). A total of 34 microplastic fragments with lengths ranging from 0.56 to 4.58 mm were categorized. Microplastic fragments were categorized into two categories: small (1.16 ± 0.42 mm) and large (4.13 ± 0.37 mm), based on the size distribution. The microplastic fragments isolated were partially rounded and some showed signs of discoloration indicating mechanical and photo-degradation. The presence of microplastic fragments in Pasig River indicates persistent plastic pollution from the river source (Laguna de Bay), its tributaries, as well as the communities and industries situated along the river. Programs on solid waste management especially on plastic wastes could mitigate the production of microplastics in the river.
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Kobylkina, T. L., M. G. Perikova, A. M. Enikeev e I. A. Gatilo. "Clinical case of peri-implantitis after orthodontic treatment". Spravočnik vrača obŝej praktiki (Journal of Family Medicine), n.º 11 (31 de outubro de 2022): 33–43. http://dx.doi.org/10.33920/med-10-2211-04.
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The materials of the article contain a description of the clinical and radiological picture of peri-implantitis. The operation of dental implantation was performed at the beginning of the retention period in orthodontic treatment. Plastic crowns on temporary abutments were made a few days after the surgical stage. As a result of immediate occlusal load and installation of dental implants in the early stages of the retention period of orthodontic treatment, their disintegration occurred.
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Wang, M. Y., C. Z. Qi, Q. H. Qian e J. J. Chen. "One plastic gradient model of zonal disintegration of rock mass near deep level tunnels". Journal of Mining Science 48, n.º 1 (janeiro de 2012): 46–54. http://dx.doi.org/10.1134/s1062739148010066.
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Onal, Merih, Gultekin Ovet e Necat Alatas. "An Asymptomatic Foreign Body in the Nose in an Eighteen-Year-Old Patient: Button Battery". Case Reports in Surgery 2015 (2015): 1–3. http://dx.doi.org/10.1155/2015/129851.
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Foreign bodies lodged in the upper airway are a common occurrence in children. Many unusual foreign bodies in the nose have been reported as foreign bodies like nuts, plastic toy parts, beads, and so forth. Most of these produce minimal morbidity but button batteries due to their early chemical disintegration require early surgical intervention. Here, we report a case of button battery lodged in the nose for several years with a symptom of nasal obstruction and chronic sinusitis.
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Dominguez-Candela, Ivan, Daniel Garcia-Garcia, Aina Perez-Nakai, Alejandro Lerma-Canto, Jaime Lora e Vicent Fombuena. "Contribution to a Circular Economy Model: From Lignocellulosic Wastes from the Extraction of Vegetable Oils to the Development of a New Composite". Polymers 13, n.º 14 (10 de julho de 2021): 2269. http://dx.doi.org/10.3390/polym13142269.
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The present works focuses on the development of a novel fully bio-based composite using a bio-based high-density polyethylene (Bio-HDPE) obtained from sugar cane as matrix and a by-product of extraction of chia seed oil (CO) as filler, with the objective of achieving a circular economy model. The research aims to revalorize an ever-increasing waste stream produced by the growing interest in vegetable oils. From the technical point of view, the chia seed flour (CSF) was chemically modified using a silane treatment. This treatment provides a better interfacial adhesion as was evidenced by the mechanical and thermal properties as well as field emission scanning electron microscopy (FESEM). The effect of silane treatment on water uptake and disintegration rate was also studied. On the other hand, in a second stage, an optimization of the percentage of treated CSF used as filler was carried out by a complete series of mechanical, thermal, morphological, colour, water absorption and disintegration tests with the aim to evaluate the new composite developed using chia by-products. It is noteworthy as the disintegration rate increased with the addition of CSF filler, which leads to obtain a partially biodegradable wood plastic composite (WPC) and therefore, becoming more environmentally friendly.
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Burton, Justin C., L. Mac Cathles e W. Grant Wilder. "The role of cooperative iceberg capsize in ice-shelf disintegration". Annals of Glaciology 54, n.º 63 (2013): 84–90. http://dx.doi.org/10.3189/2013aog63a436.
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AbstractDisintegration of several ice shelves along the Antarctic Peninsula demonstrates a mechanism that involves the conversion of a contiguous ice shelf into an expanding plume of ice-shelf fragments that spreads rapidly across the ocean surface. The growth of surface area and energetic expansion are hypothesized to be driven by gravitational potential energy release associated with iceberg capsize and break-up. Here we investigate this process using a water tank filled with plastic icebergs scaled to represent a laboratory analogue of an expanding plume of ice-shelf fragments (icebergs). Our experiments suggest that hydrodynamic pressure within the water separating neighbouring icebergs is sufficient to couple the motion when their separation is comparable to the iceberg size. This allows one iceberg’s capsize to initiate a ‘domino-like’ effect, where the entire array will subsequently capsize in the same direction and expand across the water surface. Our experimental results motivate the suggestion that cooperative iceberg hydrodynamics is a process that enhances the expansion of ice-shelf fragment plumes during ice-shelf disintegration.
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C Joshi, Pranoti, Chinmay Khanolkar e Archana Sharma. "Identification and Microscopic Classification of Microplastics in Beach Sediment Sample at Dadar Chowpatty". Contemporary Advances in Science and Technology 07, n.º 01 (2024): 117–34. http://dx.doi.org/10.70130/cast.2024.7109.
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The current study involves the design of a feasible solution for cleaning beach sediments off microplastics. The results of this study will help spread awareness about this micro-menace threatening our societies. It also focuses on otherwise neglected and invisible aspects of plastic pollution. These findings may open up new avenues for research in this area. The long-term impacts of this study may involve the conservation of food quality in fisheries and ecosystems along the coast of Mumbai. During sampling, it was observed that the Dadar Beach was relatively less polluted or disturbed. Albeit having a beach that looks clean and does not look like has a plastic pollution issue, the study results clearly indicate exactly the opposite. The results show that various microplastic particles were identified across the length of the beach and that transect 1, which is shielded by rock reclamation debris, is less affected by active wave action and shows a lower density of microplastics than transect 2, which is readily subjected to active wave action. Based on the major microplastics found in sand, the presence of filaments and disintegration in large quantities, along with foam, can be attributed to fishing activities occurring in nearby oceans, along with some washed off disintegrated plastics whose source cannot be identified.
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Tynyna, Serhii, e Ihor Chobotko. "NALYTICAL STUDIES CONCERNING RESISTANCE OF STRESSED ROCKS TO DISINTEGRATION". JOURNAL of Donetsk mining institute, n.º 2 (2020): 83–88. http://dx.doi.org/10.31474/1999-981x-2020-2-83-88.
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Purpose. State-of-the art review concerning the effect of stress-strain state of the rock upon its resistance to mechanical breaking is represented. Methods. It is highlighted that while calculating efficient breaking modes of complex stressed rock and parameters of rock-breaking machine organs, it is required to consider the degree of natural stress of the near-face rock under breaking. Results. Necessity to take into account the rock stress degree has been substantiated as the index of breaking strength of stress-free rock samples differs considerably from the one obtained with the consideration of stress state of the natural rock mass. The simple strock in terms of rheology (i.e. linear-elastic one) has been analyzed. Scientific novelty. In this context, it is taken into consideration that simultaneous availability of all the components of stress tensor due to natural and external forces does not make the rock to be plastic. It means that the rock is within the frameworks of elastic deformations. In this context, potential deformation energy accumulated within the rock volume unit is specified as the basis to determine the reduced stress in terms of which the ultimate elastic state of that volume takes place. Practical importance The amount of cone feed to the bottomhole of stressed rocks is limited by the value of the safe penetration rate, depending on the degree of rock tension.
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Rizwan, Muhammad, e Tabasam Jamal. "Degradation of Bioplastics under the Influence of Several Environmental conditions". Vol 3 Issue 1 3, n.º 3 (8 de julho de 2021): 93–101. http://dx.doi.org/10.33411/ijist/2021030302.
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The increasing threats of plastics to the natural environment encouraged the production of bio-plastics from renewable biomass resources. The premium quality of bio-plastics are mainly produced by treating starch with glycerol. Plastics are basically non-biodegradable synthetic or semi synthetic products. This study aims at analyzing the degradation patterns of bio-plastics. The bio-plastics are ecologically less toxic than the synthetic plastic materials. The bio-plastics can degrade in several environmental conditions including aquatic environment, compost and soil. The bioplastic materials are buried in composite soil or loam sand to analyze degradation activity by taking photographic data and measuring the weight. Effect of weather conditions on the degradation activity was analyzed by recording different weather conditions including temperature, humidity, rainfall sunshine intensity and duration of sunlight. The comparative results portrayed the degradation activity of bio-plastics which was accomplished through hydrophilic enzymes. The initial regenerating material absorbs moisture of soil after saturation and the weight was increased up to 87%. The weight of bio-plastics reduced steadily after the initiation of decomposition. Invasion of soil microorganisms enhance the degradation activity. The environmental features including rainfall, humidity and sunlight intensity also affects the disintegration of bioplastics. The increased intensity of sunshine increased the microbial activity of soil which in turn increased the rate of degradation of bio-plastics.
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Löser, C. "Severe Complications Caused by Dissolution of Latex with Consequent Self-Disintegration of Esophageal Plastic Tubes". Endoscopy 32, n.º 9 (setembro de 2000): 723–27. http://dx.doi.org/10.1055/s-2000-7030.
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Leonas, Karen K., e Robert W. Gorden. "An accelerated laboratory study evaluating the disintegration rates of plastic films in simulated aquatic environments". Journal of Environmental Polymer Degradation 1, n.º 1 (janeiro de 1993): 45–51. http://dx.doi.org/10.1007/bf01457652.
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Fedorov, V. T., e M. N. Kokoev. "Surface Energy in the Processes of Disintegration of Solids". Herald of Dagestan State Technical University. Technical Sciences 50, n.º 3 (29 de outubro de 2023): 181–89. http://dx.doi.org/10.21822/2073-6185-2023-50-3-181-189.
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Objective. The purpose of the study is to experimentally measure the surface energy of solids during their grinding.Method. The study is based on the use of methods for determining the surface tension of solids. At least 20-25% of all electricity produced in the world is spent on grinding materials in industry. When the resulting particles are reduced to tens of nanometers, the contribution of surface energy (st) to the grinding work becomes so large that it is difficult not to take it into account. Measuring the surface tension of liquids has long been proven. But measuring (st) of solids causes great difficulties. Currently, more than twenty methods for determining (st) are known.Result. Based on the phenomenon of spontaneous bending of thin thread-like structures, a method for determining (st) has been developed. Examples are given in which (st) at the phase interface plays an important role in obtaining samples with a microstructure using the method of severe plastic deformation (SPD). To obtain fine metal powders, one of the variants of the SPD method has been proposed. A method has been found for the physical activation of aluminum granules, which increases the reaction rate of the metal in an aqueous environment by about a thousand times. This is necessary for the development of an anaerobic power plant capable of operating at great depths.Conclusion. The new technology makes it possible to obtain high-purity, non-oxidized metal powders without toxic waste and emissions and with energy costs lower than in all known methods.
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Srinidhi, M., S. Sangeetha e P. Hari Krishna. "Interaction of Heavy Metals with Plastic Contaminated Soil". IOP Conference Series: Earth and Environmental Science 1280, n.º 1 (1 de dezembro de 2023): 012041. http://dx.doi.org/10.1088/1755-1315/1280/1/012041.
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Abstract Microplastic (MP) contamination is a threat to soil and groundwater system. Disintegration of used plastic products under exposure to solar radiations, application of sewage sludge to the soil, plastic mulching in agricultural activities leads to the formation of microplastics in significant amounts in soil. Hence there is a need from the geo environment engineering perspective on microplastic contamination in soils. Landfills and industrial areas have microplastic pollution in abundance. The presence of microplastic may alter the behaviour of liner material and surface soil in terms of heavy metal retention capacity, shrinkage, permeability and various other properties. In the present study, the soil is artificially polluted with shredded polypropylene (Pp) fragments from single use facial mask which is extensively being used in post COVID-19 situation. Heavy metals such as Lead, Nickel, Copper and Zinc at different concentrations similar to an industrially polluted soil is applied to the plastic contaminated (Pc) and normal soil. The filtrates from the test batches are studied for Total Dissolved Solids (TDS) and concentration of heavy metals using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The obtained results concluded that plastic pollution significantly varied leached out heavy metals concentration to a maximum of 4.9 times that of normal soil. The TDS of the filtrate collected from plastic polluted soil varied by 31.29%.
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Oladunjoye, R. Y., O. O. Fafioye, R. A. Asiru, G. O. Bakare e A. A. Odusolu. "Haematological and histopathological examinations of African mud catfish (Clarias gariepinus) exposed to petroleum wastewater". Scientia Africana 20, n.º 2 (7 de setembro de 2021): 127–44. http://dx.doi.org/10.4314/sa.v20i2.12.
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Effects of petroleum refinery wastewater on Clarias gariepinus juvenile were investigated. Commercially obtained C. gariepinus fingerlings were acclimatized in a plastic tank (100 L capacity) of de-chlorinated tap water at 25±2°C for 14 days and fed with commercial feed pellet at 2% body weight of the fingerlings. Bioassay tests were carried out in four transparent plastics tank with nominal concentrations of 100 ml, 200 ml, 300 ml of the wastewater added to 40L of de-chlorinated tap water and only de-chlorinated tap water as control. Each tank contains twenty fish samples, while the assay was replicated three times concurrently. Following standard procedures, behavioural response, growth changes, haematological and histopathological tests were carried out on the samples. Significant reduction in the weight was observed in the fingerlings cultured with the wastewaters, while no significant difference occurred in the control fish. Highest values of Packed Cell Volume (PCV) (22), Haemoglobin (HB) (7.0), Red Blood Cell (RBC) (1.62) and endocochlear potential (EP) (5) were recorded for the control fish than exposed fish. On the other hand, Haptoglobin (HP), Mean Corpuscular Volume (MCV) and Mean Corpuscular Haemoglobin (MCH) were higher in the blood of exposed fish than in control. Histopathologically, exposed fishes showed no visible lesion in gills except from the thickening of the lamellae as the concentration of wastewater increases, indicating an increase in tissue disintegration. Similarly, gross tissue disintegration was observed in those fish exposed to 200ml wastewater as evidenced by the presence of large open spaces (hepatocytes) in the liver.
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Haldar, Shoumi, Nounenuo Yhome, Yuvashree Muralidaran, Senthilkumar Rajagopal e Prabhakar Mishra. "Nanoplastics Toxicity Specific to Liver in Inducing Metabolic Dysfunction—A Comprehensive Review". Genes 14, n.º 3 (26 de fevereiro de 2023): 590. http://dx.doi.org/10.3390/genes14030590.
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Plastic pollution in the world is widespread and growing. The environment is swamped with nanoplastics (<100 nm), and the health consequences of these less visible pollutants are unknown. Furthermore, there is evidence that microplastics can release nanoplastics by digestive disintegration, implying that macroplastic exposure can cause direct and indirect disease via nanoplastics. The existence and impact of nanoplastics in numerous tissues from invertebrates to larger vertebrates that consume significant amounts of plastics were investigated, and histopathological techniques were utilized to determine physiological reactions and inflammation from the plastics. Nanoplastics enters an organism through the respiratory and gastro-intestinal tract where they accumulate into the liver through blood circulation via absorption, or epidermal infiltration. It is stated that macroplastics can cause damage directly at the site of exposure, whereas nanoplastics can influence the liver, causing subsequent damage to other organs. Multi-organ dysfunction is brought on by liver changes, and nanoplastics can readily enter the gut-liver axis and disturb the gut microflora. By exploring the literature and summarizing the research that has been published to date, this review article reveals the deleterious effect and mechanisms of nanoplastics on the pathophysiological functions of the hepatic system.
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Gao, Wenle, Yuming Kou, Tongqing Yan, Hong Sun e Saijiang Li. "Case Study on the Effect of Delay-Time Differences between Columns during Blasting Demolition of RC Structures with a Small Height-to-Width Ratio". Applied Sciences 13, n.º 11 (2 de junho de 2023): 6765. http://dx.doi.org/10.3390/app13116765.
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Blasting demolition plays an important role in building demolition, and numerical-simulation methods can facilitate the optimization of blasting-demolition schemes. To study the influence of the delay-time differences between columns on the blasting and demolition effect of small-aspect-ratio reinforced concrete structures, a separated common node model of small-aspect-ratio structures was established through the finite element numerical simulation software ANSYS/LS-DYNA. The results showed that the delay-time differences between columns influenced the position of the plastic hinge of the structure, and the plastic hinge was located at the end of the back span beam when the delay-time difference was 0.1~0.3 s. The plastic hinge moves to the top of the back row of the columns of the first floor at 0.4~0.8 s and to the end of each span of the beams at 0.9 s. When the plastic hinge is at the end of the beam, the orientation axis is located at the bottom of the back row of the columns of the first floor. Moreover, when the plastic hinge is at the top of the back row of the columns of the first floor, the orientation axis is at the same position as the plastic hinge. The delay-time difference also affects the recoil distance of the structure as well as the height of the burst pile. To ensure that the structure can be successfully collapsed under the preconditions of disintegration, for a small height-to-width ratio structure, the appropriate intercolumn delay-time difference is 0.4~0.5 s.
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Erdeni, Abed, Dhyaa Jwher, Muntaha Hassan e Dhamyaa Doory. "Enhancing the composting process by using lactic acid bacilli for the hygienic disposal of dead fish". Open Veterinary Journal 13, n.º 11 (2023): 1458. http://dx.doi.org/10.5455/ovj.2023.v13.i11.9.
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Background: Fish producers in Iraq currently facing large and growing problems, represented by the difficulty of getting rid of large numbers of dead fish as a result of mass phenomenon mortality since 2018. As their treatment and disposal has become very cumbersome and costly, and leaving it to wild animals and natural forces is unacceptable, so most of them resort to the composting method because it's a simple, easy, and inexpensive process, and benefits outputs, but it takes a long time. Aim: The study aimed to compare two different composting methods for the disposal of dead fish, one of them includes the use of lactic acid bacilli (LAB) to improve composting efficiency. Methods: Sawdust, hay, one-inch perforated plastic tubes, plastic covers, and dead fish were used to make four equal composting piles, two of them were treated with LAB, and others were left to compost naturally, the composted content was daily tested physically for color, odors, pH estimation, and LAB count. Results: The results showed that there are significant differences between normal composed and LAB treated groups in duration, and efficiency, the total threshold limits of temperature, pH, and LAB count were 60 ± 8 0C, 6.7 ± 0.04 and 10.8×106 ± 1.96 CFU/g, respectively, in normal composting groups, while they were 70 ± 2.8 0C, 4.26±0.01, and 23.2×106 ±1.34 CFU/g, respectively, with total decomposition and disintegration of fish carcasses through 31 days in EM treated groups. Conclusion: We concluded that the using of LAB in composted materials led to a quick and efficient composting process in terms of heat, pH, LAB count, total disintegration speed, and the ability of biosafety.
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Kuleshova, O. N. "AGE AND SEX CHARACTERISTICS OF THE BEHAVIOR OF PRENATALLY STRESSED RATS IN A BLACK-AND-WHITE MODIFICATION OF THE BEHAVIORAL MODEL “SUOK-TEST”". Журнал высшей нервной деятельности им. И.П. Павлова 73, n.º 4 (1 de julho de 2023): 550–62. http://dx.doi.org/10.31857/s0044467723040068.
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Research activity, anxiety and motor disintegration were studied in prenatally stressed immature and adult male and female rats in the Suok-test model. The mothers of these animals from the 16th to the 19th days of pregnancy were placed for 3 hours in plastic pencil cases that fix the animals. The offspring were tested on day 20 and month 4 of postnatal ontogenesis. Mature females were tested taking into account the estrous cycle. A decrease in anxiety and an increase in research activity was observed in all experimental groups, with the exception of mature females at the diestrus stage. At this stage of the estrous cycle, behavioral patterns were identified in females that characterize anxiety and a decrease in the research component of behavior. Sensorimotor disintegration characteristic of immature animals was compensated with age, but not in females at the diestrus stage. Thus, according to the results of the study, it can be concluded that prenatal stress can carry both adaptive functions, causing the growth of the research component of behavior, and maladaptive ones. The anxiolytic effects of prenatal stress are rather negative, reducing evolutionarily significant protective mechanisms.
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P. Sebastian, Gerald, Rajinidevi Kaliyan e Pethuru Devadason. "Button battery foreign body among children: a case series". International Journal of Otorhinolaryngology and Head and Neck Surgery 6, n.º 5 (21 de abril de 2020): 978. http://dx.doi.org/10.18203/issn.2454-5929.ijohns20201699.
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<p>In children the foreign bodies are a common occurrence which may be either accidental or self-induced as a matter of habit. Various materials like metal, plastic toy parts, food matters, etc have been reported as foreign bodies. Button batteries have been reported as foreign bodies in the ear, nose and throat are very relevant and practical, due to their early chemical disintegration in contact with mucosal surface; hence, need emergency surgical intervention to avoid complications. Here, we report five cases of button batteries in the ear nose and throat at various stages of presentation with their sequelae.</p>
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Kawashima, Nobuyuki, Tadashi Yagi e Kouya Kojima. "Pilot-Scale Composting Test of Polylactic Acid for Social Implementation". Sustainability 13, n.º 4 (4 de fevereiro de 2021): 1654. http://dx.doi.org/10.3390/su13041654.
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The chemical industry and subsequent value chain of plastics are facing significant challenges from the viewpoints of resource conversion and environmental burden. Now is the time to explore the future direction of plastics, which will require an integrated scheme using resource circulation, carbon neutrality, and a social system to promote after-use treatment under the concept of a circular economy. Polylactic acid (PLA) should help reduce greenhouse gas (GHG) emissions as a biobased material and contribute to waste management after use due to its biodegradability if managed properly. That is, it will be necessary to treat biodegradable products appropriately in closed systems such as composting facilities after use and recovery. To realize the implementation of fully approved composting facilities in society, simply evaluating biodegradability in the laboratory is insufficient. In this study, a pilot-scale test using PLA under actual composting conditions was conducted in accordance with both international standards and domestic evaluation methods. The results not only confirm its biodegradability and disintegration, but also demonstrate that the presence of a biodegradable plastic product has a negligible impact on the composting process. The obtained compost did not adversely affect plant germination or growth, demonstrating its safety and high quality. Such a multifaceted perspective makes this study unique and useful for creating a social framework.
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Leonas, Karen K. "The disintegration rate of traditional and chemically modified plastic films in simulated fresh- and sea-water environments". Journal of Applied Polymer Science 47, n.º 12 (20 de março de 1993): 2103–10. http://dx.doi.org/10.1002/app.1993.070471203.
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Ortega, Florencia, Pablo Sobral, Jorge L. Jios, Valeria B. Arce e María Alejandra García. "Starch Nanocomposite Films: Migration Studies of Nanoparticles to Food Simulants and Bio-Disintegration in Soil". Polymers 14, n.º 9 (19 de abril de 2022): 1636. http://dx.doi.org/10.3390/polym14091636.
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In this work, films containing AgNPs were obtained by different green synthesis techniques (AgNP in situ and AgNP L). The inclusion of nanoparticles in the starch matrix improved both mechanical and barrier properties. The migration of AgNPs from the nanocomposite material to three food simulants (water, 3% v/v acetic acid and 15% v/v ethanol) was studied. The experimental data were fitted by using different widely accepted mathematical models (Fickian, Ritger and Peppas, and Weibull), indicating that the AgNP migration followed a complex mechanism. The silver concentration (mg Ag per kg of simulant) that was released from the nanocomposite films was higher for the samples with AgNPs in situ than for those containing AgNP L. Likewise, the maximum release value (0.141 mg/dm2 for AgNPs in situ in acetic acid simulant) was lower than the limits proposed by the legislation (European Commission and MERCOSUR; 10 and 8 mg/dm2, respectively). The replacement of conventional plastic materials by biodegradable ones requires the evaluation of bio-disintegration tests in soil. In this sense, a period of 90 days was necessary to obtain ≥50% weight loss in both nanocomposite films. Additionally, the bio-disintegration of the samples did not contribute with phytotoxic compounds to the soil, allowing the germination of fast-growing seeds.
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Verastegui, Cristian Andres Arias, Norma Elizabet Clemente Gilvonio e Michelle Esthefani Retamozo Flores. "A bibliometrics study of plants, animals, bacteria, algae and technologies that reduce, filter and eliminate microplastics from planet earth, ecological solutions for the environment". Decision Science Letters 12, n.º 4 (2023): 773–82. http://dx.doi.org/10.5267/j.dsl.2023.6.004.
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The world surrounded by plastics generates a lot of uncertainty and the first victims are sea animals, plastic in contact with the sun is able to disintegrate and generate toxins that are harmful to health. It is for this reason that this research in bibliographic review allows us to know the different solutions to counteract microplastics through the analysis of the Scopus database and the VOSviewer tool that allows us to analyze the data, considering the essential characteristics that are plants, animals, bacteria, algae and technologies that allow the disintegration, elimination and purification of microplastics, graphs and tables were obtained which allow us to recognize the analyzed data, the countries that carry out these investigations and the bibliometric maps worldwide. The results allow us to understand that the existence of microplastics generates many negative consequences for planet earth, however, there are different solutions which we can use and apply to counteract these microplastics, also considering that countries like Peru do not find published scientific research relevant to this matter. The purpose of this research is to allow us to make better decisions and not lose heart in the face of microplastics since it can be fought with the different solutions that we find on planet earth, technology and the other objective is to motivate readers to take action in the issue and allow generating change in the use of plastics.