Use Of Plastics Research Articles

Development of gadgets and systems in plastic for use in freshwater aquaculture

The usage of plastics has transformed the agricultural production sector and has great impactin improving the overall scenario in all production systems including fisheries and aquaculture.Nylon fishnets, components of RAS, aquaponics and biofloc (BF)systems, plastic pipe framed nylon net cages, pen culture in water locked areas, etc. are some of the important uses of plastics in aquaculture. The AICRP on PEASEM, ICAR-CIFA, Bhubaneswar Centre is working since its inception in 1988 and contributed several plasticulture technologies and products for the development of aquaculture systems and processes (APA/CIFA 1988-2005; Mohapatra et.al., 2003, 2011 and 2016). The design and fabrication of the plastic gadgets and systems have been done considering the biological requirements of the aquaculture. The developed technologies are fully or partially adopted and accepted by the farming communities of the country. The paper presents some of the developed gadgets and systems that are presently in use in aquaculture in the country. Those are portable FRP carp hatchery having capacity of 1.0-1.2 million spawn production per cycle; portable FRP magur hatchery for incubation of 50,000 eggs per cycle; portable FRP pabda hatchery for production of 25,000-30,000 early fry per operation; different types of fixed and floating cages; live fish transportation tank of 1200l capacity which can be transported in a jeep trailer, power trailer or trolley; FRP silos of different sizes for fish rearing; feeders of different types such as demand, semiautomatic and automatic for fish feeding; plastic covered ponds for raising fishes in winter season; floating nursery for fish seed and aquaponics.. KEYWORDS :Modern farming Technique, Gedgets Plastic, Aquaculture

Mechanically Robust Reversibly Cross‐Linked Polymers with Closed‐Loop Recyclability for Use in Flexible Printed Circuit Boards

AbstractIt remains a huge challenge to efficiently recycle the printed circuit boards (PCBs) because of the diversity and complexity of the PCBs in terms of material composition. The recycling of PCBs highly depends on the design of the polymers that make up the polymer substrates and conductive pastes. Herein, closed‐loop recyclable plastics for use as the polymer substrates and for the preparation of the conductive pastes are fabricated by dynamically cross‐linking phenylboronic acid‐functionalized poly(methylmethacrylate) (PMMA‐B) and poly(urea‐urethane) (PUU‐B) with boroxines. The closed‐loop recyclable plastic, which is denoted as PMMA‐PUU exhibits a breaking strength of 71.0 MPa and Young's modulus of 1.8 GPa. Because of the dynamic nature of boroxines, the PMMA‐PUU0.6 plastic can be depolymerized in the N, N‐dimethylacetamide/ethanol mixture solvent. The depolymerized PMMA and PUU can be efficiently recovered in high yields and purity through their solubility differences in selective solvents. Conductive pastes suitable for printing of electrical circuits are fabricated through complexation of Ag particles with PMMA‐PUU. PCBs composed of PMMA‐PUU substrates and PMMA‐PUU‐based conductive pastes are flexible, healable, and recyclable. The closed‐loop recycling of the PCBs enables the collection of highly purified Ag particles, PMMA‐B, and PUU‐B monomers even when the PCBs are mixed with polymer wastes.

Progress of Carrageenan‐Based Films and Coatings for Food Packaging Applications

ABSTRACTAs a polysaccharide extracted from marine red algae, carrageenan has the advantages of biodegradability, nontoxicity and water solubility over petroleum‐based plastics for use as films and coatings for keeping food fresh. Aqueous solutions of carrageenan can be cast into films on plates and then made into food packaging bags, as well as coated directly onto food surfaces, all of which are referred to as ‘wraps’. To overcome the inherent limitations of carrageenan as a packaging material, physical and chemical modifications have been studied. The mechanical, thermal, barrier and antibacterial properties of modified carrageenan make it widely applicable for extending the shelf life of food products and monitoring its freshness. The research progress of carrageenan‐based wraps in recent years has been reviewed in terms of preparation methods, physicochemical properties, gelation mechanisms and applications, and the factors affecting the drying rate of them have been analysed. Finally, applications and future research directions of carrageenan are summarized and discussed to provide useful guidelines for further research.

Assessing the viability of 3D-printed poly(lactic acid) petri dishes: A sustainable alternative for laboratory use

There is a strong reliance on fossil fuel-based plastics in the life sciences sector and it has been estimated that global life-sciences (biology, medicine, etc.) alone create plastic waste of approximately 5.5 million tonnes/year with 99% of single-use laboratory plastics made from fossil-fuel sources There is growing interest in the viability of bioplastics as an alternative to fossil fuel-based single-use plastics in laboratory settings. Here, we report the use of polylactic acid (PLA) in the production of a single-use Petri dish. The properties of the PLA Petri dish are tested and compared to the standards for assessing plastics for use in labware, as per the International Organization for Standardization (ISO). We demonstrate, for the first time, that a compostable PLA Petri dish meets all the necessary standards for use in laboratories, thereby taking the first steps towards reducing the negative impacts of plastic waste in laboratories.

EXPERIMENTAL STUDY ON THE STRUCTURAL BEHAVIOUR OF RECYCLED PLASTIC ONE STORY HOUSES

Recycling plastic materials may constitute a relief measure to the global plastic problem. Several companies are now producing recycled plastic for use as construction material in single-story houses. One commercially available layout involves assembling Recycled Plastic Lumber units in a running bond pattern, forming panels confined by horizontal and vertical tie elements joined through bolted steel plate connections. As production of houses is industrialized, the architectural layouts are standardized according to specific distribution and dimensions. This paper presents the findings of an experimental program aimed to characterize the seismic behavior and properties of a one-story house model. To facilitate practical application, the model is referred here as Architectural Standard Model (ASM). The objectives of the test campaign were to investigate the structural behavior of the constituting members and assemblies, and the response of structural walls to cyclic static lateral loads. Three natural scale wall specimens were tested in-plane and two out of plane. Results of natural scale cyclic loading tests demonstrated that structural system of the ASM can perform acceptably safely under high seismic loads if it is adequately fixed to the foundation. The results showed that out of plane loading was the critical pattern and behaved like a unidirectional plate that transmitted load to the columns. In plane observed behavior exhibited predominating rocking component, which suggests considering an evaluation of the system's response using dynamic methods.

Optimized Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) Production by Moderately Haloalkaliphilic Bacterium Halomonas alkalicola Ext

Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible polymers that are produced by microorganisms as storage materials under limited nutrition and excess carbon. These PHAs have been found to be ideal for replacing synthetic plastics for use in packaging and biomedical applications. In this study, an alkaliphilic and moderately halophilic bacterium Halomonas alkalicola Ext was isolated from Lake Simbi Nyaima in western Kenya and investigated for PHA production. Sudan Black B and Nile Red A staining showed that bacterium had distinct ability for accumulation of PHAs. To optimize PHA production, the bacterium was grown in submerged fermentation under varying culture conditions and different sources and concentrations of carbon and nitrogen. With one-factor-at-a-time (OFTA) approach, optimal PHA yields were obtained after 72 hours at a pH of 10.0, temperature of 35°C, and 2.5% (w/v) NaCl. The bacterium yielded the highest biomass, and PHA amounts on 2% galactose and 0.1% ammonium sulfate as sources of carbon and nitrogen, respectively. A record PHA yield of 0.071 g g-1 with a titer of 1.419±0.09 g/L was achieved from 3.397 g/L of biomass, equivalent to 41.8% PHA content. Using response surface methodology, PHA titer was increased by 1.5% to 1.44 g/L, while PHA content was improved 1.1-fold to 45.57%. Polymer analysis revealed that the extracted PHA was a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) (3−HB:3−HV=92:8) with two copolymer subunits of 3-hydroxyvaryrate (3-HB) and 3-hydroxybutyrate (3-HV). Halomonas alkalicola Ext attained efficient galactose conversion into PHBV under high salinity and alkalinity conditions.

Degradation Behavior of Glue-On Three-Dimensional Printed Plastic Horseshoes in Equine Stables

Hoof and leg problems in racehorses can cause serious injuries and decrease their value. Although therapeutic shoeing using special horseshoes can increase the effectiveness of veterinary care, it is labor-intensive and burdensome for farriers. A three-dimensional (3D) printed horseshoe fabricated by additive manufacturing has high design flexibility for use in special horseshoes. However, the mechanical properties of 3D printed plastics for use as horseshoes remain unclear. In this study, a proposed 3D printed plastic was subjected to degradation tests under the simulated equine growth environment, and changes in strength during the period of use were investigated. It was found that the strength of polylactic acid and polycarbonate, which are commonly used for 3D printing, was not significantly affected by the environment.

KOMPARASI PRAKTIK GREEN ACCOUNTING PADA PERUSAHAAN DI INDONESIA: PERSPEKTIF PERUSAHAAN JASA DAN PERUSAHAAN DAGANG

This study aims to determine the similarities and differences betweenservice and trading companies' green accounting practices. PT BankMandiri (Persero) Tbk is used as a sample for service companies andPT Matahari Department Store Tbk is a sample for tradingcompanies. The method used descriptive comparative by comparingthe green accounting practices of the two companies disclosed in theirannual reports and sustainability reports. These two companies donot carry out production activities, but both provide quitecomprehensive environmental responsibilities. The two companiesrecycle waste, offer environmentally friendly products, reduce the useof plastic and paper, and work to reduce the negative effects ofgreenhouse gas emissions. The difference between the two lies inwhether or not a special team handles the environment and thedifferent components included in the details of environmentalmanagement costs.

Valorised polypropylene waste based reversible sensor for copper ion detection in blood and water

Heavy metals and plastic pollutants are the two most disastrous challenges to the environment requiring immediate actions. In this work, a techno-commercially feasible approach to address both challenges is presented, where a waste polypropylene (PP) based reversible sensor is produced to selectively detect copper ions (Cu2+) in blood and water from different sources. The waste PP-based sensor was fabricated in the form of an emulsion-templated porous scaffold decorated with benzothiazolinium spiropyran (BTS), which produced a reddish colour upon exposure to Cu2+. The presence of Cu2+ was checked by naked eye, UV–Vis spectroscopy, and DC (Direct Current) probe station by measuring the current where the sensor's performance remained unaffected while analysing blood, water from different sources, and acidic or basic environment. The sensor exhibited 1.3 ppm as the limit of detection value in agreement with the WHO recommendations. The reversible nature of the sensor was determined by cyclic exposure of the sensor towards visible light turning it from coloured to colourless within 5 min and regenerated the sensor for the subsequent analysis. The reversibility of the sensor through exchange between Cu2+- Cu+ was confirmed by XPS analysis. A resettable and multi-readout INHIBIT logic gate was proposed for the sensor using Cu2+ and visible light as the inputs and colour change, reflectance band and current as the output. The cost-effective sensor enabled rapid detection of the presence of Cu2+ in both water and complex biological samples such as blood. While the approach developed in this study provides a unique opportunity to address the environmental burden of plastic waste management, it also allows for the possible valorization of plastics for use in enormous value-added applications.

Novel Electrospun Cotton-Like Nano/Microfiber from Waste Polycarbonate Plastic for Use as Filler Fiber in Outerwear Textiles

Novel Electrospun Cotton-Like Nano/Microfiber from Waste Polycarbonate Plastic for Use as Filler Fiber in Outerwear Textiles

Material properties and water resistance of inorganic–organic polymer coated cellulose paper and nanopaper

Cellulose-based materials represent a renewable, biodegradable, and environmentally friendly alternative to plastic from fossil resources. Nanopaper is a strong and lightweight material formed from cellulose nanofibrils (CNFs). Paper and nanopaper have been considered as excellent alternatives to plastics for use in agriculture and for packaging applications. However, common for both paper and nanopaper is their hydrophilic character, and consequently, poor water-resistance properties. ORMOCER®s are a class of inorganic–organic polymers with excellent barrier and protective properties used for a range of coating applications. Here we present ORMOCER®-coated paper and nanopaper. The coated papers and nanopapers are characterized, both in terms of their morphology, hydrophobicity, and mechanical properties. We demonstrate that the pressure used during the pressing and drying of paper and nanopaper influence their tear and tensile—properties, and that the morphology of the coated nanopaper differs significantly from that of the coated paper. While the ORMOCER® was impregnated within the porous network of the paper, a well-defined two-layered morphology was obtained with the coated nanopaper. Further, the biodegradability of the nanopaper with and without coating was assessed. The degradation study demonstrated that both the pressure used during the pressing and drying of the nanopaper, and the composition of the ORMOCER®, influenced the rate of degradation. Taken together, ORMOCER®-coated paper and nanopaper are promising for the preparation of materials that are both water-resistant, renewable, and biodegradable.

Advances in the Modification of Natural Polymers for Applications in Food Packaging and Preservation

Synthetic plastics are polymers produced from petrochemicals and are typically used as packaging materials. They are portable, lightweight, and strong. The main issue with synthetic plastics is that they cannot degrade, which is why natural polymers, also known as biopolymers, have emerged. By using biopolymers, synthetic plastics' toxic effects on the environment are reduced. Although it is nearly impossible to completely replace all conventional polymers with environmentally friendly materials, natural polymers may be used in many industries including the food and packaging materials sector. Natural resources like plant and animal waste are commonly used as raw materials to create environmentally friendly packaging. However, there are some disadvantages to natural plastics, such as poor water absorption and a weak defence against microbial attack. Natural polymers must be modified to achieve desired properties and extend shelf life. This study examines the most popular techniques for modifying natural plastics for use in the preservation and packaging of food.

EMI Shielding Using Flexible Optically Transparent Screens for Smart Electromagnetic Environments

Past generations of wireless systems focused largely toward power and bandwidth to support higher data rates, coverage, and quality of service. Smart electromagnetic environments, on the other hand, are aimed at meeting these expectations through modifications in the electromagnetic properties of the geometry, which were once considered an uncontrollable part of a wireless system. This is done through careful placement of smart electromagnetic structures that can constructively manipulate the propagation of electromagnetic waves. In this work, we present optically transparent electromagnetic screens for shielding applications that require visual observation. New aluminum-doped zinc oxide (AZO) thin films, that are low-loss, and optically transparent, are deposited on plastic for use as absorbing-type shields. We also present a simple and reliable technique to fabricate all-metallic single-layer reflecting-type shields. All these shields have a unique combination of shielding effectiveness (SE) and optical transparency that advance the state of the art. They can be used as curtains or walls in indoor environments, windows for autonomous vehicles and as covers to shield smart IoT devices.

Assessment of economic feasibility of LDPE-sand composite block for construction

Construction industry is looking for materials and methods that can be used to enhance the sustainability aspects. One approach is the use of industrial/agricultural waste products in construction. Plastic bricks are emerging as a new trend in construction due to its lightweight, durability and high strength properties. The current paper explores the economic viability of LDPE-sand composite blocks as a construction material. The composite was manufactured from waste plastic and is meant to replace traditional bricks that are generated in an unsustainable manner. In the study, a G+9 building model was chosen, and an analysis was performed using standard bricks available on the market. The results are compared with the similar model with LDPE-sand composite bricks. It has been noticed that the low weight of LDPE-sand brick leads to an economic gain by decreasing the overall infrastructure material requirements in terms of concrete and steel, resulting in a 12% cost reduction. As a result, the waste plastic will have extra value and it will encourage the society to recycle waste plastic for use in the building sector.

From bottle to microplastics: Can we estimate how our plastic products are breaking down?

Microplastics (MPs) have become an emerging new pollutant of rising concern due to the exponential growth of plastics in consumer products. Most MP and nanoplastic pollution comes from the fragmentation of plastics through mechanical stress, chemical reactions and biological degradation that occurs during use and after disposal. Models predicting the generation and behavior of MP in the environment are developing, however there is lack of data to predict the rates of MP generation as a function of the abrasive forces. A method to deliver scalable, quantitative release rates of MPs during mechanical stress throughout a plastic's life cycle (e.g., sanding, chewing, river and ocean disposal) is described. A custom abrasion machine was built with features to provide data to calculate power input. The generation rate of MPs through abrasion was tested for the following 3D printed polymers: polylactic acid (PLA), polycarbonate (PC), thermoplastic polyurethane 85A (TPU), polyethylene glycol terephthalate (PETG), high-impact polystyrene (HIPS), and nylon. Each material underwent tensile strength material tests to identify which mechanical properties drive their abrasion rate. Abrasion rate was not observed to correlate to macroscopic mechanic properties. Results indicate that the order of abrasion from most to least were HIPS, nylon, PC, PLA, PETG, and then TPU. This study will help comprehend and provide data to understand generation rates of MPs from consumer plastic products and macro-plastic debris. This will be instrumental in helping to better understand the release of MPs and nanoplastics into the environment and to provide data for fate and transport models, especially in order to predict the amount of plastic entering water systems. MP generation rates and power inputs can be correlated with each plastic's use to inform which release the most MPs and how to better change these products in order to reduce pollution in water sources.

The impacts of plastic products on air pollution - A simulation study for advanced life cycle inventories of plastics covering secondary microplastic production

A framework, SecµPlast, to include secondary microplastic (MP) formation due to photooxidation into current Life Cycle Assessments (LCA) from cradle-to-grave of products. The framework details how to incorporate secondary MP formation into the plastic's life cycle as related to the plastic's use phase, and location specific waste treatment and how to connect the impacts with current life cycle impact assessment methodologies (LCIA). Plastics, now ubiquitous in the environment are a potential source of emerging pollution and have been shown to have negative effects of various species. Thus, the framework consist of 1) a degradation module, which accounts for micro- and nano- plastic formation with dynamic degradation of microparticles, 2) an emissions module accounts for the potential of the plastic particles to be emitted to air, and 3) an impacts module which connects the various emissions to existing LCIA methods. The framework allows for quantification of secondary microplastic in an LCA context and for further characterization of the impacts at endpoints in terms of human health, and allows for a high level of regionalization, both in terms of input data and characterization of impact damages. SecµPlast was tested on a case study of mulch film which showed that the per kg contribution to particulate matter (PM) and other impacts is low. The impacts vary largely depending on the degradation rate and ranged from 9.24×10 −6 to 0.00043 kg PM equivalents per kg of mulch film, depending on either a slow or fast degradation rate, respectively. The impact came mostly from the littered fraction, which was estimated to be 10% of the products weight after the use phase, in Europe. The degradation rates due to UV degradation were low, 0.034 µg/year for a slow degradation rate, compared to values derived from the literature, 0.345 µg/year for a fast degradation rate during littering, that included other sources of degradation, such as abrasion. However, when these impacts are scaled up to the European consumption of plastics and monetized, it is evident that even small increases of PM are costly for society and could potentially amount to millions of dollars per year in human health damages. Further research efforts should focus on filling data gaps, such as microplastic losses during production, recycling and potentially incineration, as well as degradation kinetics including other degradation factors such as freeze/thawing, wet/drying in combination with UV degradation.

Observations of Atypical Habitat Use by Foothill Yellow-Legged Frogs (Rana boylii) in the Coast Range of California

Foothill Yellow-legged Frogs (Rana boylii) have experienced extreme range-wide declines in recent decades. This stream-dwelling species is thought to be in decline primarily due to the alteration of streams through anthropogenic water development, the effects of which may be exacerbated by climate change. Although R. boylii has long been considered an obligate inhabitant of perennial streams, recent observations indicate that this species exhibits greater behavioral plasticity in habitat use, particularly for reproduction. Herein, we report on several observations of R. boylii using atypical habitat for both refuge and reproduction. We found several R. boylii individuals reproducing within lentic habitat over a several year period. We also found up to 27 egg masses of R. boylii in a primarily mud-substrate intermittent stream, where the species bred and recruited individuals in 5 of 10 years. Behavioral plasticity in the use of habitat types described herein indicates a possible search bias in traditional Rana boylii surveys. Our observations may have implications for future assessment of R. boylii habitats and for species recovery.

Resource plasticity-driven carbon-nitrogen budgeting enables specialization and division of labor in a clonal community.

Previously, we found that in glucose-limited Saccharomyces cerevisiae colonies, metabolic constraints drive cells into groups exhibiting gluconeogenic or glycolytic states. In that study, threshold amounts of trehalose - a limiting, produced carbon-resource, controls the emergence and self-organization of cells exhibiting the glycolytic state, serving as a carbon source that fuels glycolysis (Varahan et al., 2019). We now discover that the plasticity of use of a non-limiting resource, aspartate, controls both resource production and the emergence of heterogeneous cell states, based on differential metabolic budgeting. In gluconeogenic cells, aspartate is a carbon source for trehalose production, while in glycolytic cells using trehalose for carbon, aspartate is predominantly a nitrogen source for nucleotide synthesis. This metabolic plasticity of aspartate enables carbon-nitrogen budgeting, thereby driving the biochemical self-organization of distinct cell states. Through this organization, cells in each state exhibit true division of labor, providing growth/survival advantages for the whole community.

АДАПТИВНЫЙ ПОТЕНЦИАЛ ИСХОДНОГО МАТЕРИАЛА В СЕЛЕКЦИИ МЯГКОЙ ЯРОВОЙ ПШЕНИЦЫ

The work was carried out in 2019 in five ecological points of Kurgan region: at Kurgan Scientific Research Institute of Agriculture and at 4 state-owned sections (Belozerskiy, Polovinskiy, Kurtamyshskiy, Dalmatovskiy). The purpose of the research is to identify varieties with high productivity and ecological plasticity for use in crosses when creating new highly productive spring wheat varieties. We tested 26 varieties of various biotypes with a growing season from 70 (Novosibirskaya 16) to 92 (Lider 80) days. Plant height ranged from 65 to 110 cm. The best in yield in the early ripening group (29.5 ... 30.3 c/ha) were Omskaya 36, Tarskaya 12, Extra; mid-season (32.6 ... 32.9 kg/ha) - Heracles Icarus, Zauralskaya volna; medium-late (36.6 ... 37.4 kg / ha) - Bulyak, KVS Buran, KVS 240-3-13. Dusty smut (defeat 27 ... 30%) was observed in Silach, Raduga, KVS Torridon varieties. High resistance to stress (U2-U1 = -8.6 ... -11.6) was found in the genotypes Zauralochka, Tarskaya 12, Zauralskaya volna, low (-20.3 ... -28.0) Lider 80, Novosibirskaya 16, Bulyak. The most stable under changing growing conditions were Zauralochka variety samples (V = 11.8%; Hom = 29.4), Zauralskaya wave (V = 16.3%; Hom = 17.4), and Raduga (V = 16%; Hom = 17.7%). Low ductility at the level of bi = 0.31 ... 087 was recorded in the varieties Zauralochka, Novosibirskaya 16, Tarskaya 12, Omskaya 36, Boevchanka, Zauralskaya volna. Varieties KVS Torridon, Raduga, KVS Buran, KVS Jetstream, Krasnozerka, Zauralskaya zhemchuzhina, Lutetsiya, KVS 240-3-13 can be grown on an intensive background (σd2 = 0.6 ... 5.0). Raduga variety formed a consistently high productivity in different growing conditions. According to a set of indicators and related calculations, it is recommended to use the following varieties combining yield with ecological plasticity parameters for inclusion in the system of crosses: early ripening - Extra, Tarskaya 12; mid-season - Hercules, Icarus, Lutetsiya; medium-late - KVS 240-3-1, Bulyak, KVS Buran.

Study on Brain Plasticity of EEG Signals Based on Motor Imagination Training

To explore the effects of hand motion imagery on brain plasticity for use in guiding disabled people to use robotic arms, this paper designed a comparison experiment between the disabled and normal people, and collected the EEG data of 4 subjects (2 disabled men who lost their right hands and 2 normal men) for five weeks of training. What’s more, this paper compared and analyzed the collected EEG rhythm through the brain topographic map. The results showed that after training, the disabled people could produce ERD in both the μ and β frequency bands, and the longer the training time, the more obvious the ERD phenomenon was. This paper also uses the common space pattern algorithm and support vector machine to extract and classify the features of EEG signals. The results show that the classification accuracy of the disabled can reach more than 85%, and that of the normal can reach more than 90%. Based on the results of brain topographical map and classification, this paper concludes that motor imagination training can have a positive effect on the brain of people with impaired motor area, which provides a neurophysiological basis for the extensive application of motor imagination training in the field of rehabilitation.