Types Of Plastic Research Articles

Potential valorization and transformation of plastic biomass waste into useful fertilizers in agricultural Mediterranean soils under extreme climate conditions

Plastics are widely used in agricultural practices, although recently they have been recognized as a new emerging risk in soils. Polyethylene (PE), is commonly used by farmers to cover agricultural practices; geotextile, is used mainly for ground and crop covering; and polyvinyl chloride (PVC) is considered the main material contained in irrigation hoses. The present study aimed to assess the effects of three plastics (polyethylene, geotextile, polyvinyl chloride) on the soils’ fertility. Several pot experiments were conducted in soil samples from the study area (Thessaly) contaminated with adequate amounts of each plastic type (PE, geotextile: 2% v/v and PVC: 5% v/v). Water was added in two quantities: one to maintain typical soil moisture levels according to the crops’ requirements and an elevated amount to form supersaturating soil conditions similar to those following a flood event. Furthermore, temperature effect was also investigated to assess its impact on plastics’ behavior and soil fertility. The levels of all nitrogen forms and the microbial activity were determined at 10, 30, and 60 days. Significant changes were observed in the concentrations of nitrate, nitrite, and ammonium ions under ambient soil moisture conditions especially when the microplastics were incubated for a longer period. PE addition resulted in greater changes, followed by geotextile, although PVC addition did not induce significant changes in the nitrification process during the experimental time. PE and geotextile microplastics appeared to enhance microbial colonization and total microbial activity. In addition, soil characteristics were notably altered when moisture stress conditions were reached (85%) and when soils were flooded for two months, leading to a severe decrease in the availability of all nitrogen forms. The results showed that alterations in soil nitrogen forms in the presence of plastics study are crucial for maintaining the health and improving the productivity of Mediterranean soils.

Conceptual framework for identifying polymers of concern

With the increasing global concern over plastics' environmental and human health impacts, the urgency for effective regulatory measures is evident. The UN Environment Assembly's initiative to establish an international, legally binding instrument via the Intergovernmental Negotiating Committee (INC) on Plastic Pollution marks a significant step toward addressing this issue. However, the vast diversity of plastic types and their myriad applications present a complex challenge in pinpointing the most critical targets for regulation. This study builds on the existing body of literature to outline potential key criteria for identifying Polymers of Concern (PoC). We recommend a dual-focused definition of PoCs considering both (1) the type of the plastics and (2) their domain of applications based on the environmental and human health impacts throughout the polymer's life cycle. Recognizing the current gaps in our understanding of the full spectrum of plastics' impacts across their life cycles, we suggest adopting a precautionary approach that factors in the volume of plastics entering natural ecosystems alongside their life cycle impacts as reported in the literature. We then bring forward existing data on the assessment of some of the main polymer types and applications. We propose that policymakers examine a wide spectrum of strategies including not only bans and phaseouts but also economic incentives, innovation, and the redesign of plastic materials and products to mitigate the adverse impacts of PoCs. We further emphasize the importance of thoroughly assessing the feasibility, costs, and environmental, social and economic implications of alternative materials to avoid “regrettable substitution.” We conclude by identifying existing knowledge gaps and emphasizing the need for further research to refine the proposed criteria for identifying PoCs.

Optimizing the ratio of coomassie and methylene blue dyes for a cost-effective and rapid staining of PET, PVC, PP, PS, LLDPE, LDPE, and HDPE

The ubiquitous presence of plastic brought on by the extensive use of plastic products calls for efficient and rapid plastic detection methods to detect and evaluate pollution. The commonly used Nile red dye takes many hours and is expensive while also not equally efficient across all the common plastic waste. To address this, we investigated the staining efficiency and optimized the ratio of a combined Coomassie brilliant blue and Methylene blue dye. In the optimisation process, Methanol-based Coomassie and Methylene blue dyes effectively stained the Polyethylene Terephthalate (PET), Polypropylene (PP), Polystyrene (PS), Linear Low-Density Polyethylene (LLDPE), Low-Density Polyethylene (LDPE), and Linear Low-Density Polyethylene (HDPE) plastics without compromising the plastic's integrity. Image analysis showed a generally better staining efficacy compared to Nile red. Through systematic experimentation, we identified specific optimal ratios of Coomassie (C) brilliant blue: Methylene (M) blue for various plastics: 5:5 (mass) for PVC, 7:3 (mass) for PET, and 8:2 (mass) for PP, LDPE, and HDPE. Additionally, the ratio of 10:0 (mass) was found suitable for PS and LLDPE. Given the cost-effectiveness, efficiency, and accessibility of the blue dyes in labs, the optimized ratio of the blue dyes makes it suitable for large-scale plastic staining across the six tested types of plastic, replacing Nile red.

Determining the preeminent plastic wastes in the production of petrol using pyrolysis method and its effectiveness as an alternative fuel

Abstract: This study aimed to determine which type of plastic – PET, HDPE, LDPE, PP, PS, and Others, produces most oil yield in terms of time of complete degradation, temperature and amount of plastics using a non-catalytic slow pyrolysis method; it also determined the physical characteristics of the oil yield in terms of its color and appearance; and it also aimed to determine which petroleum produced by different types of plastics are more efficient in terms of (a) production of oil and (b) combustion time. Production of oil and oil yield is presented in milliliters and percentage, respectively. Combustion time is expressed in seconds from the time of ignition to total disappearance of flame having 1ml of oil tested from each produced pyrolytic oil. Experimental-descriptive comparative method was used in determining the type of plastic that yields to most of pyrolytic oil. Based from gathered results, at constant temperature and amount of plastics, PS produced most petroleum at 29.5% oil yield followed by PP with 29%. While PET produced the least petroleum with 0.01% oil yield. Color varies at different types of plastics, given that PET and PP produces light brown color, LDPE produces light yellow while HDPE, PS and Others produces black color. PET, HDPE, PP, PS and Others produced liquefied petroleum while LDPE produces flammable wax product. PS produced most petroleum with 295ml (29.5%), and PET produced least oil with 1ml (0.01%). Combustion time varies at different types of plastics: PS at 145 seconds, PP at 141 seconds, HDPE at 115 seconds, Others at 78 seconds, LDPE at 77 seconds while PET produced non – flammable oil yield. Thus, PS is most efficient as an alternative fuel in terms of production and combustion time. For the betterment of similar study, future researchers are encouraged to test the pyrolytic oil yielded from different types of plastics in engine performance and machineries and the comparative performance to the available commercial fuels.

A chromosome-level genome assembly for the amphibious plant Rorippa aquatica reveals its allotetraploid origin and mechanisms of heterophylly upon submergence

The ability to respond to varying environments is crucial for sessile organisms such as plants. The amphibious plant Rorippa aquatica exhibits a striking type of phenotypic plasticity known as heterophylly, a phenomenon in which leaf form is altered in response to environmental factors. However, the underlying molecular mechanisms of heterophylly are yet to be fully understood. To uncover the genetic basis and analyze the evolutionary processes driving heterophylly in R. aquatica, we assembled the chromosome-level genome of the species. Comparative chromosome painting and chromosomal genomics revealed that allopolyploidization and subsequent post-polyploid descending dysploidy occurred during the speciation of R. aquatica. Based on the obtained genomic data, the transcriptome analyses revealed that ethylene signaling plays a central role in regulating heterophylly under submerged conditions, with blue light signaling acting as an attenuator of ethylene signal. The assembled R. aquatica reference genome provides insights into the molecular mechanisms and evolution of heterophylly.

Thermodynamic simulation study on compression ignition engine operating with oil obtained via catalytic pyrolysis of waste polythene covers

In recent years, waste-to-energy systems are receiving more attention due to their dual benefit of reduction of pollution caused by waste materials and reducing the overconsumption of fossil fuels. Since plastic waste is readily available and has a high heating value, it is a viable source of energy.; plastic garbage makes an excellent source of energy. Today, a feedstock made up of several types of plastic is used to quickly pyrolyze and produce plastic pyrolysis oil (PPO) or waste plastic oil (WPO). The oil could be utilized in internal combustion engines to produce heat and power. In the current work, waste polythene covers were transformed into value added products by utilizing fly ash catalyst and oil obtained is examined for suitability to run in the diesel engine. In the primary phase simulation study is performed on a four-stroke single cylinder DI Compression ignition engine using Diesel-RK engine simulator, results indicated that, waste plastic oil was found to emit higher oxides of nitrogen compared to diesel therefore in the secondary phase the same engine simulated by implementing exhaust gas recirculation at 3.5 %,7 %,10.5 % and 14 % rates. In the end engine parameters get optimized using 3D parametric optimization technique.Simulation Results indicate that, performance parameters such as brake power, brake thermal efficiency and brake specific fuel consumption were found to be decreased slightly under EGR conditions. Furthermore, combustion parameters such as cylinder peak pressure and peak temperature decrease up on implementing the exhaust gas recirculation, similarly the emission characteristics such as CO2, PM and smoke found to be increase with increase in EGR ratio while oxides of nitrogen emissions significantly decreased under EGR conditions. In order to reduce the emissions further, a 3D parametric optimization technique was adopted and optimal results obtained when engine runs at compression ratio of 16.5, injection timing of 19.38 and EGR percentage of 4.8 %.

Metagenomic investigations into the microbial consortia, degradation pathways, and enzyme systems involved in the biodegradation of plastics in a tropical lentic pond sediment.

The exploitation of exciting features of plastics for diverse applications has resulted in significant plastic waste generation, which negatively impacts environmental compartments, metabolic processes, and the well-being of aquatic ecosystems biota. A shotgun metagenomic approach was deployed to investigate the microbial consortia, degradation pathways, and enzyme systems involved in the degradation of plastics in a tropical lentic pond sediment (APS). Functional annotation of the APS proteome (ORFs) using the PlasticDB database revealed annotation of 1015 proteins of enzymes such as depolymerase, esterase, lipase, hydrolase, nitrobenzylesterase, chitinase, carboxylesterase, polyesterase, oxidoreductase, polyamidase, PETase, MHETase, laccase, alkane monooxygenase, among others involved in the depolymerization of the plastic polymers. It also revealed that polyethylene glycol (PEG), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polyethylene terephthalate (PET), and nylon have the highest number of annotated enzymes. Further annotation using the KEGG GhostKOALA revealed that except for terephthalate, all the other degradation products of the plastic polymers depolymerization such as glyoxylate, adipate, succinate, 1,4-butanediol, ethylene glycol, lactate, and acetaldehyde were further metabolized to intermediates of the tricarboxylic acid cycle. Taxonomic characterization of the annotated proteins using the AAI Profiler and BLASTP revealed that Pseudomonadota members dominate most plastic types, followed by Actinomycetota and Acidobacteriota. The study reveals novel plastic degraders from diverse phyla hitherto not reported to be involved in plastic degradation. This suggests that plastic pollution in aquatic environments is prevalent with well-adapted degrading communities and could be the silver lining in mitigating the impacts of plastic pollution in aquatic environments.

From Polyester Plastics to Diverse Monomers via Low-Energy Upcycling.

Polyester plastics, constituting over 10% of the total plastic production, are widely used in packaging, fiber, single-use beverage bottles, etc. However, their current depolymerization processes face challenges such as non-broad spectrum recyclability, lack of diversified high-value-added depolymerization products, and crucially high energy consumption. Herein, an efficient strategy is developed for dismantling the compact structure of polyester plastics to achieve diverse monomer recovery. Polyester plastics undergo swelling and decrystallization with a low depolymerization energy barrier via synergistic effects of polyfluorine/hydrogen bonding, which is further demonstrated via density functional theory calculations. The swelling process is elucidated through scanning electron microscopy analysis. Obvious destruction of the crystalline region is demonstrated through X-ray crystal diffractometry curves. PET undergoes different aminolysis efficiently, yielding nine corresponding high-value-added monomers via low-energy upcycling. Furthermore, four types of polyester plastics and five types of blended polyester plastics are closed-loop recycled, affording diverse monomers with exceeding 90% yields. Kilogram-scale depolymerization of real polyethylene terephthalate (PET) waste plastics is successfully achieved with a 96% yield.

The 5HT2b Receptor in Alzheimer's Disease: Increased Levels in Patient Brains and Antagonist Attenuation of Amyloid and Tau Induced Dysfunction.

Background: Neurodegenerative diseases manifest behavioral dysfunction with disease progression. Intervention with neuropsychiatric drugs is part of most multi-drug treatment paradigms. However, only a fraction of patients responds to the treatments and those responding must deal with drug-drug interactions and tolerance issues generally attributed to off-target activities. Recent efforts have focused on the identification of underexplored targets and exploration of improved outcomes by treatment with selective molecular probes. As part of ongoing efforts to identify and validate additional targets amenable to therapeutic intervention, we examined levels of the serotonin 5-HT2b receptor (5-HT2bR) in Alzheimer's disease (AD) brains and the potential of a selective 5-HT2bR antagonist to counteract synaptic plasticity and memory damage induced by AD-related proteins, amyloid-β, and tau. This work used a combination of biochemical, chemical biology, electrophysiological, and behavioral techniques. Biochemical methods included analysis of protein levels. Chemical biology methods included the use of an in vivo molecular probe MW071, a selective antagonist for the 5HT2bR. Electrophysiological methods included assessment of long-term potentiation (LTP), a type of synaptic plasticity thought to underlie memory formation. Behavioral studies investigated spatial memory and associative memory. 5HT2bR levels are increased in brain specimens of AD patients compared to controls. 5HT2bR antagonist treatment rescued amyloid-β and tau oligomer-induced impairment of synaptic plasticity and memory. The increased levels of 5HT-2bR in AD patient brains and the attenuation of disease-related synaptic and behavioral dysfunctions by MW071 treatment suggest that the 5HT-2bR is a molecular target worth pursuing as a potential therapeutic target.

Biotransformation of Pollutants by Pycnoporus spp. in Submerged and Solid-State Fermentation: Mechanisms, Achievements, and Perspectives

Substantial amounts of organo-pollutants, often persistent and toxic, are generated globally each year, posing a threat to soil, water, groundwater, and air. The pollutants encompass a wide range of substances from various sources, which include solid as well as liquid ones, such as landfill leachates and wastewaters. The compounds include paper and pulp mill byproducts, pharmaceuticals, diverse types of plastics, hydrocarbons, pigments, and dyes, as well as pesticides and insecticides. Fungal bioremediation stands out as a promising technology that uses the metabolic potential of fungi to eliminate or mitigate the impact of pollutants. Notably, species of the genus Pycnoporus exhibit significant capabilities for degrading a broad spectrum of toxic molecules. This degradation is facilitated by released ligninolytic enzymes, especially laccase, and cellular enzymes pertaining to the cytochrome P450 monooxygenase system. The laccase, which is overproduced by the genus Pycnoporus, is quite remarkable for its high redox potential. The objective of this review is to highlight the proficiency of the Pycnoporus genus in the degradation of pollutants in submerged and solid-state fermentation. Recent studies conducted over the past decade consistently highlight the Pycnoporus genus as a robust contender in the realm of white biotechnology.

Fast Detection and Classification of Microplastics below 10 μm Using CNN with Raman Spectroscopy.

In light of the growing awareness regarding the ubiquitous presence of microplastics (MPs) in our environment, recent efforts have been made to integrate Artificial Intelligence (AI) technology into MP detection. Among spectroscopic techniques, Raman spectroscopy is preferred for the detection of MP particles measuring less than 10 μm, as it overcomes the diffraction limitations encountered in Fourier transform infrared (FTIR). However, Raman spectroscopy's inherent limitation is its low scattering cross section, which often results in prolonged data collection times during practical sample measurements. In this study, we implemented a convolutional neural network (CNN) model alongside a tailored data interpolation strategy to expedite data collection for MP particles within the 1-10 μm range. Remarkably, we achieved the classification of plastic types for individual particles with a mere 0.4 s of exposure time, reaching an approximate confidence level of 85.47(±5.00)%. We postulate that the result significantly accelerates the aggregation of microplastic distribution data in diverse scenarios, contributing to the development of a comprehensive global microplastic map.

Study on the pyrolysis characteristics, kinetics, thermodynamics, volatile products, and chemical reactions of micron polyamide waste, a typical marine plastic microfragment

AbstractThe pollution of waste plastic microfragments to the marine ecosystems is an increasingly serious problem. Pyrolysis is widely recognized as a viable technique for the treatment of such plastic waste materials. The pyrolysis behaviors, characteristic parameters, kinetics, thermodynamics, volatiles, and possible chemical reactions during the pyrolysis of micron polyamide waste (the main component of fishing gear abandoned in the marine environment) are studied in inert atmosphere in the present work. The results show that the pyrolysis of micron polyamide may be regarded as a one‐step reaction. The peak and average reaction rates decrease significantly when the heating rate increases. The calculated kinetic parameters can effectively predict the pyrolysis behaviors of micron polyamide. The pyrolysis of micron polyamide is characterized as an endothermic reaction that occurs non‐spontaneously. Furthermore, the information of volatiles was obtained. The volatiles with higher content were –CH2 groups, CO2, and lactam, and the volatiles with smaller content were: –NH groups, NH3, HCN, H2O, CO, and amide derivatives. In addition, an analysis was conducted to explore the potential chemical reactions.Highlights The pyrolysis of micron polyamide can be considered as a one‐step reaction. The obtained kinetic parameters can well predict the pyrolysis process. Pyrolysis of micron polyamide is a non‐spontaneous and endothermic reaction. Specific volatile products are determined by Fourier transform infrared and mass spectrometry. The chemical reactions that may occur during the pyrolysis have been inferred.

Neurotoxicity of dibutyl phthalate in zebrafish larvae: Decreased energy acquisition by neurons

This work was designed to investigate the neurotoxic effects of the typical plasticizer dibutyl phthalate (DBP) using zebrafish larvae as a model. The results of exhibited that zebrafish larvae exposed to DBP at concentrations of 5 μg/L and 10 μg/L exhibited brain malformations (24 h) and behavioral abnormalities (72 h). After 72 h of exposure to DBP, microglia in the brain were over-activated, reactive oxygen species (ROS) formation was increased, and apoptosis was observed. Meanwhile, it was found that neurons exhibited impaired mitochondrial structure, absent mitochondrial membrane potential and up-regulated autophagy. Further comprehensive biochemical analyses and RNA-Seq, validated by RT-qPCR, glutamate metabolism and PPAR signaling pathway were significantly enriched in the DBP stress group, this may be the main reason for the disruption of glycolysis/gluconeogenesis processes and the reduction of energy substrates for the astrocyte-neuron lactate shuttle (ANLS). In addition, the DBP-exposed group showed aberrant activation of endoplasmic reticulum (ER) stress signaling pathway, which may be related to ROS as well as neuronal apoptosis and autophagy. In conclusion, DBP-induced neurotoxicity may be the combined result of insufficient neuronal energy acquisition, damage to mitochondrial structure, apoptosis and autophagy. These results provide a theoretical basis for understanding the neurotoxic effects of DBP.

A thorough evaluation of chitosan-based packaging film and coating for food product shelf-life extension

Chitosan is a cationic polysaccharide and derived from chitin present in exoskeleton of crustaceans such as prawns, crabs, and lobsters. This natural biopolymer chemical structure is identical to cellulose but insoluble in aqueous and organic solvents. Chitosan is an ecologically beneficial biodegradable alternative to synthetic polymers, notably typical plastics. Chitosan may be used to make a variety of films, coatings, and membranes, each having its own distinct features. Chitosan films are biodegradable, translucent, and have high mechanical strength, making them adequate for food packaging, water purification, and wound dressings. Chitosan-based films and coatings are often used for packaging foods such as fruits and vegetables, meat, and seafood. According to the findings, chitosan films have outstanding barrier qualities against UV radiation, gases, and moisture. They can assist in safeguarding packed objects from outside influences such as oxidation and humidity, which could degrade their quality. Chitosan's antibacterial qualities naturally limit the development of bacteria, viruses, and fungi. Because of this property, chitosan-based films are useful for packaging perishable food products since they may extend shelf life by lowering microbial contamination. Modifying the chitosan content or adding additional components can change the mechanical strength and flexibility of the film. Surfaces may be treated with chitosan coatings to improve qualities such as water resistance, barrier properties, and antibacterial activity. This review article discusses different approaches such as solvent casting, extrusion, electrospinning, thermoplastic method, layer-by-layer assembly, spraying, dipping for the preparation of chitosan-based films and coatings. Further these food packaging material properties such as viscosity, thermal properties, optical properties, solubility, hydrophobicity, color, mechanical characteristics, barrier qualities, antibacterial properties, antioxidant activity and prolonging the shelf life of products is described in depth.

Environmental Life Cycle Assessment of Two Types of Flexible Plastic Packaging under a Sustainable Circular Economy Approach

While it is of great importance to evaluate plastic waste within the framework of a circular economy today, it is also of great importance to evaluate flexible plastic packaging, which is increasingly used in order to prevent environmental problems. To avoid the disadvantages experienced in recycling due to its multilayer nature, in this study, a life cycle assessment was made for flexible packages consisting of PET/metallized PET/PE and PP/metallized PP/PP with the data provided by the R&D Center of Elif Plastik Ambalaj Sanayi ve Tic. A.Ş.-Huhtamaki Flexibles Istanbul. Within the scope of this evaluation, two types of flexible packaging were analyzed, and an optimal flexible packaging structure for Türkiye was revealed by comparing different scenarios based on different methods in SimaPro 8.1.1.16. LCA was performed for both packages with cumulative energy demand (CED) and CML-IA methods. Four scenarios with different amounts of recycled raw materials were compared against the existing system and a fifth scenario, where electricity is assumed to be obtained from solar energy. Overall, we found that the largest environmental impact was in the existing system. However, despite being a renewable energy source, we observed that the solar energy scenario had almost as significant an impact as the existing system. When scenarios involving recycled raw materials were examined, we clearly observed that as the amount of recycled raw materials increased, the environmental impact decreased. Therefore, it emerged that the scenario with the highest amount of recycled raw materials is the most optimal scenario in many respects. There are clear differences in the results due to differences in plastic types. This study, conducted with real data, is highly important for the flexible packaging literature. A table has been provided for changing the type of plastic, changing the source of electricity generation, and reducing waste by using recycled raw materials in order to make flexible packaging more environmentally beneficial.

Soil erosion is a major drive for nano & micro-plastics to enter riverine systems from cultivated land

Nano and micro-plastics (NMPs, particles diameter <5 mm), as emerging contaminants, have become a major concern in the aquatic environment because of their adverse consequences to aquatic life and potentially human health. Implementing mitigation strategies requires quantifying NMPs mass emissions and understanding their sources and transport pathways from land to riverine systems. Herein, to access NMPs mass input from agricultural soil to riverine system via water-driven soil erosion, we have collected soil samples from 120 cultivated land in nine drainage basins across China in 2021 and quantified the residues of six common types of plastic, including polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polypropylene (PP), polyethylene (PE), polycarbonate (PC), and polystyrene (PS). NMPs (Σ6plastics) were detected in all samples at concentrations between 3.6 and 816.6 μg/g dry weight (median, 63.3 μg/g) by thermal desorption/pyrolysis-gas chromatography-mass spectrometry. Then, based on the Revised Universal Soil Loss Equation model, we estimated that about 22,700 tonnes of NMPs may enter the Chinese riverine system in 2020 due to agricultural water-driven soil erosion, which occurs primarily from May to September. Our result suggested that over 90% of the riverine NMPs related to agricultural soil erosion in China are attributed to 36.5% of the country's total cultivated land, mainly distributed in the Yangtze River Basin, Southwest Basin, and Pearl River Basin. The migration of NMPs due to water-driven soil erosion cannot be ignored, and erosion management strategies may contribute to alleviating plastic pollution issues in aquatic systems.

Optimization of the Thickness, Water Vapour Transmission Rate and Morphology of Protein-Based Films Incorporating Glycerol and Polyethylene Glycol Plasticizers

Edible film is a thin layer that can coat food products and protect them from physical, chemical, and microbiological disturbances. This study aimed to determine the effect of the concentration ratio and different plasticizers on the thickness, water vapour transmission rate, and morphology of protein-based edible films. The study used a completely randomized design with a factorial pattern. The experiment involved two factors: Factor A, which was the whey-gelatine concentration ratio, at three levels (A1 = 1:0.5; A2 = 1:0.75; A3 = 1:1); and Factor B, which was the plasticizer, at two levels (B1 = glycerol; B2 = polyethylene glycol (PEG)). The study revealed that the water vapour transmission rate was significantly affected (P&lt;0.01) by the interaction between whey-gelatin and different types of plasticizers. Additionally, the film thickness was significantly affected (P&lt;0.01) by the whey-gelatine ratio, and the water vapour transmission rate was significantly affected (P&lt;0.01) by the different types of plasticizers used. The film made from protein had a thickness of 0.282-0.357 mm, a water vapour transmission rate of 4.27-5.55 g/mm2.h, and a homogeneous surface structure resulting from the good mixing of whey and gelatin. The concentration of whey-gelatine and the use of different plasticizers can affect the thickness, WVTR, and morphology of the film. The use of glycerol as a plasticizer resulted in a greater thickness, water vapour transmission rate (WVTR), and morphology compared to those of the PEG plasticizer when the whey-gelatin concentration was 1:1.

Searching for new plastic-degrading enzymes from the plastisphere of alpine soils using a metagenomic mining approach.

Plastic materials, including microplastics, accumulate in all types of ecosystems, even in remote and cold environments such as the European Alps. This pollution poses a risk for the environment and humans and needs to be addressed. Using shotgun DNA metagenomics of soils collected in the eastern Swiss Alps at about 3,000 m a.s.l., we identified genes and their proteins that potentially can degrade plastics. We screened the metagenomes of the plastisphere and the bulk soil with a differential abundance analysis, conducted similarity-based screening with specific databases dedicated to putative plastic-degrading genes, and selected those genes with a high probability of signal peptides for extracellular export and a high confidence for functional domains. This procedure resulted in a final list of nine candidate genes. The lengths of the predicted proteins were between 425 and 845 amino acids, and the predicted genera producing these proteins belonged mainly to Caballeronia and Bradyrhizobium. We applied functional validation, using heterologous expression followed by enzymatic assays of the supernatant. Five of the nine proteins tested showed significantly increased activities when we used an esterase assay, and one of these five proteins from candidate genes, a hydrolase-type esterase, clearly had the highest activity, by more than double. We performed the fluorescence assays for plastic degradation of the plastic types BI-OPL and ecovio® only with proteins from the five candidate genes that were positively active in the esterase assay, but like the negative controls, these did not show any significantly increased activity. In contrast, the activity of the positive control, which contained a PLA-degrading gene insert known from the literature, was more than 20 times higher than that of the negative controls. These findings suggest that in silico screening followed by functional validation is suitable for finding new plastic-degrading enzymes. Although we only found one new esterase enzyme, our approach has the potential to be applied to any type of soil and to plastics in various ecosystems to search rapidly and efficiently for new plastic-degrading enzymes.

Multilevel thermoplastic waste segregation and classification with AHGSO using federated learning framework

PurposeAn abundance of techniques has been presented so forth for waste classification but, they deliver inefficient results with low accuracy. Their achievement on various repositories is different and also, there is insufficiency of high-scale databases for training. The purpose of the study is to provide high security.Design/methodology/approachIn this research, optimization-assisted federated learning (FL) is introduced for thermoplastic waste segregation and classification. The deep learning (DL) network trained by Archimedes Henry gas solubility optimization (AHGSO) is used for the classification of plastic and resin types. The deep quantum neural networks (DQNN) is used for first-level classification and the deep max-out network (DMN) is employed for second-level classification. This developed AHGSO is obtained by blending the features of Archimedes optimization algorithm (AOA) and Henry gas solubility optimization (HGSO). The entities included in this approach are nodes and servers. Local training is carried out depending on local data and updations to the server are performed. Then, the model is aggregated at the server. Thereafter, each node downloads the global model and the update training is executed depending on the downloaded global and the local model till it achieves the satisfied condition. Finally, local update and aggregation at the server is altered based on the average method. The Data tag suite (DATS_2022) dataset is used for multilevel thermoplastic waste segregation and classification.FindingsBy using the DQNN in first-level classification the designed optimization-assisted FL has gained an accuracy of 0.930, mean average precision (MAP) of 0.933, false positive rate (FPR) of 0.213, loss function of 0.211, mean square error (MSE) of 0.328 and root mean square error (RMSE) of 0.572. In the second level classification, by using DMN the accuracy, MAP, FPR, loss function, MSE and RMSE are 0.932, 0.935, 0.093, 0.068, 0.303 and 0.551.Originality/valueThe multilevel thermoplastic waste segregation and classification using the proposed model is accurate and improves the effectiveness of the classification.

Three pillars of national art – Igor Vieru, Ilia Bogdesco, Mihail Petric – 100 years since their birth

The article is focused on the creation of three plastic artists from the Republic of Moldova, who would have celebrated their centenary this year – Igor Vieru (1923-1988), Ilia Bogdesco (1923-2010), Mihail Petric (1923-2005). Their contribution is a significant one for national art, each one leaving a considerable mark in the field and genre they work. Several aspects and factors of the creative process of each individual artist are mentioned in the article. The thematic topics addressed are described, the components of the plastic language used in the process of creating a work of art, and the types of plastic and technical realization of the works are revealed. In their creation there is a coexistence of traditional and innovative elements in the plastic treatment of works of art. Depending on the historical period, the illustrative-realistic vision in painting (I. Vieru, M. Petric) is replaced by a decorative one, inspired by Romanian plastic folklore and the aesthetic concepts of modern European art (post-impressionism, Fauvism, etc.). In the creation of the graphic artist Ilie Bogdesco, who prefers a „classic” work technique, technical procedures and stylistic features not specific to contemporary national graphics are encountered. He practices calligraphy in book illustration and develops a new author’s technique, based on the text from the national medieval miniatures. Poets in soul and philosophers in thought, the celebrated artists remain trailblazers for the plastic arts in the Republic of Moldova, who have le¡ a unique spiritual trail in their track record.