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Abstract

This article describes the technology of organic recycling of polylactide/halloysite biocomposites using the sugar- protein condensation theory. For this purpose, polymer biocomposites were produced with a polylactic acid structure and reinforced in the form of halloysite nanoparticles by 1; 2.5; and 5% by mass. A new method of decomposition of the produced biocomposites was developed. For this purpose, the composting process uses complex sugars in the form of beet molasses. This action is based on Stevenson’s theory of protein-sugar condensation. Thus, the validity of this theory was confirmed, as research showed that this modification significantly influences the acceleration of the composting process of the produced biomaterials. For each phase of the process, the parameters of accelerated composting were defined by determining the temperature, degree of humidity, and quantitative scale of acidity and alkalinity. The degree of decomposition of biocomposites was assessed based on microbiological tests, hardness, weight loss, viscosity-average molecular weight tests, and structure assessment using macro and microscopic examinations (SEM). Based on the microbial tests, it was shown that composting also seems to be an alternative method of infectious waste disposal in the case of using biocomposites for products, e.g., medical product.

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This review article summarises the sources, occurrence, fate and effects of plastic waste in the marine environment. Due to its resistance to degradation, most plastic debris will persist in the environment for centuries and may be transported far from its source, including great distances out to sea. Land- and ocean-based sources are the major sources of plastic entering the environment, with domestic, industrial and fishing activities being the most important contributors. Ocean gyres are particular hotspots of plastic waste accumulation. Both macroplastics and microplastics pose a risk to organisms in the natural environment, for example, through ingestion or entanglement in the plastic. Many studies have investigated the potential uptake of hydrophobic contaminants, which can then bioaccumulate in the food chain, from plastic waste by organisms. To address the issue of plastic pollution in the marine environment, governments should first play an active role in addressing the issue of plastic waste by introducing legislation to control the sources of plastic debris and the use of plastic additives. In addition, plastics industries should take responsibility for the end-of-life of their products by introducing plastic recycling or upgrading programmes.
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The properties of poly(butylene terephthalate) (PBT) based nanocomposites filled with MWCNTs (multiwall carbon nanotubes) and epoxy peroxide functionalized MWCNTs (EpMWCNTs) have been studied. The analysiswas focused on the influence ofEpMWCNTs on the phase structure, thermal, mechanical and electrical properties of synthesized materials. FunctionalizedMWCNTswere observed to be highly dispersed and well integrated in the PBT matrix. Obtained results demonstrate that the incorporation of EpMWCNTs into the PBT matrix yields materials of enhanced thermo-oxidative stability. Itwas found that the crystallization temperature for all the obtained nanocomposites is slightly higher than that for the neat polymer. Increasing the concentration of nanofiller in both MWCNT and EpMWCNT systems improved the mechanical properties Young's modulus, tensile strength and fracture strain. The electrical conductivity of nanocomposites decreased due to the functionalization ofMWCNTs with epoxy peroxide.
Chapter
A wide range of naturally occurring polymers derived from renewable resources are available for material applications. Some of these, such as cellulose and starch, are actively used in products today, while many others remain underutilized. With the rapid advancement in understanding of fundamental biosynthetic pathways and options to modulate or tailor these pathways through genetic manipulations, new opportunities for the use of polymers from renewable resources are being considered. These biopolymers are derived from a diverse set of polysaccharides, proteins, lipids, polyphenols, and specialty polymers produced by bacteria, fungi, plants and animals. Some of these polymers have recently been reviewed (for examples, see [5, 12, 26, 45, 74, 131].
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Rational waste management in Poland is one of the most important social, ecological and economic problems. Composting is an optimal method of waste management. It is a continuous process, which consists in the decomposition of organic substance subjected to biochemical processes and the influence of microorganisms. It is usually defined as the sum of microbiological processes related with the formation of humus. Properly made compost is characterized by a large value of fertilizer, often exceeding the fertilizer value of manure. The admixture or the use of biodegradable waste for composting contributes to higher aeration of the composted mass, facilitates reaching the optimal humidity range of 50-60%, enriches the composted mass with a source of carbon which is accessible to microorganisms and guarantees the optimal C:N ratio. However, in the production of compost main objective is to optimize the conditions of this process. The aim of this study was to determine the dynamics of changes in the number of selected groups of microorganisms and dehydrogenase activity levels occurring during the composting of pine bark, depending on the application of different organic additives and microbiological preparation and changes in temperature. The experiment was established in the Forest District Antonin in Wielkopolska. Composting was carried out in six piles of pine bark supplemented with different doses of green mass of legumes, Effective Microorganisms solution and urea. During the composting process, samples were taken three times for microbiological analysis. It were analyzed total number of mesophilic bacteria, actinomyces, copiotrophs, oligotrophs and fungi on selective substrates. Isolated colonies were used to determine the total number of tested micro organisms. Furthermore, were tested the enzymatic activity of microorganisms, determining the activity of the dehydrogenase, using the spectrophotometric method with TTC as a substrate. Also were analyzed the impact of differences in the composition of compost on the growth of microorganisms. The following terms were also tested the temperature of the windrows. Above all, the trend in the variation in the population of microorganisms under analysis and enzymatic activity depended on the type of admixture applied to the composted pine bark. In most of the analyzed terms the largest number of different groups of bacteria and fungi was observed in combination of pine bark, and extended to the highest dose of the green mass of the plants and EM-A. To changes in the number of analyzed groups of microorganisms also fundamentally affect temperature changes during the composting process. Dehydrogenase complex activity did not increase with the increase in the number of analyzed groups of microorganisms. © 2015, Middle Pomeranian Scientific Society. All rights reserved.
Chapter
This chapter discusses the chemical nature of N in soil humus with emphasis on incorporation, stabilization, and availability of immobilized fertilizer N in soil. The studies on soil N availability and on indices of N availability have been discussed, with reviews of humic substances (HS) as related to soil fertility. 15N studies demonstrate that from 20 to 40% of the fertilizer N added to agricultural crops of the temperate-zone soils is incorporated into organic forms during the first growing season. In comparison to the native humus N, more of the newly immobilized N occurs as amino acids and amino sugars, and less occurs in unidentified forms. The newly immobilized N is more susceptible to mineralization or extraction. Stabilization processes, including polymerization reactions between amino compounds and polyphenols, lead to the incorporation of N into humic structures and a gradual reduction in N availability. The chapter concludes with the studies that are involved in a broad range of conventional and solid-state techniques and have been applied to the characterization of organic N complexes.
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Die theoretischen Grundlagen eines Verfahrens zur Bestimmung von [η] aus einer einzigen Viskositätsbestimmung werden erörtert. Die folgende Gleichung zur Berechnung von [η] wird abgeleitet:
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Items of clothing recovered after 133 years of submersion at a deep-ocean shipwreck site provided a unique source of marine-degraded textiles. In this research, both dyed and undyed cotton samples taken from a man's waistcoat were studied by optical and scanning electron microscopy and by energy dispersive x-ray spectroscopy. The undyed fibers showed features typical of localized biodegradation, and two different forms of cellulolytic micro-organisms were observed. Black deposits, perhaps formed by sulfate-reducing bacteria, were observed on both the dyed and undyed samples. After treatment with a mixture of sodium hydroxide plus carbon disulfide, fibrillation and horizontal fragmentation of the dyed and undyed cotton fibers, respectively, were observed. In contrast, new cotton samples treated similarly with sodium hydroxide and carbon disulfide formed the “balloons” typical of fibers with intact primary walls. Tin was present only in the dyed sample. Its source is probably a mordant used in the dyeing process. It is likely that the tin aided in protecting the fabric from attack by cellulolytic micro-organisms.
Article
The origin of ions in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry is currently a matter of active research. A number of chemical and physical pathways have been suggested for MALDI ion formation, including gas-phase photoionization, ion–molecule reactions, disproportionation, excited-state proton transfer, energy pooling, thermal ionization, and desorption of preformed ions. These pathways and others are critically reviewed, and their varying roles in the wide variety of MALDI experiments are discussed. An understanding of ionization pathways should help to maximize ion yields, control analyte charge states and fragmentation, and gain access to new classes of analytes. © 1999 John Wiley & Sons, Inc. Mass Spec Rev 17: 337–366, 1998
Article
Previous study showed that co-composting sewage sludge with lime would effectively reduce the availability of heavy metals in the sludge compost. In the present study, effects of addition of lime on the microbial activities of sewage sludge composting were evaluated in a bench-scale in-vessel system through monitoring biological parameters including microbial respiration, microbial populations (thermophile and mesophile), and activities of related enzyme (dehydrogenase, alkaline phosphatase, β-glucosidase, and urease). Lime raised the pH of the sludge compost effectively at the initial period, and this effect became less obvious with an increase in composting time. Adverse effects of lime amendment on all biological parameters increased with an increase in lime application rates, but these effects were generally restricted to the early stage of the thermophilic phase. Addition of 0.63% lime prior to sludge composting slightly improved the microbial activity as indicated by the higher temperature and CO2 evolution and did not exert a significant inhibition on bacterial population, and the activities of β-glucosidase, alkaline phosphatase, and dehydrogenase after 100 days of composting. This together with our previous results on heavy metal availability supports the use of lime at a rate of
Article
In recent years, interest in using natural fibers in a number of applications especially in biocomposites has grown because they are eco-friendly, lightweight, combustible, nontoxic, low cost and easy to recycle. On the other hand, the lack of good interfacial adhesion and poor resistance to moisture absorption and chemicals make the use of natural fibers less attractive. Chemical treatment of the lignocellulosic fiber can stop the moisture absorption process, clean the fiber surface, chemically modify the surface or increase the surface roughness. Silane treatment of natural fibers is a promising process for improving physical and chemical properties of fibers. The work presented in this article gives insight into the effect of silane treatment on physical and chemical properties of Pinus fibers. Further polymer composites were prepared using urea-formaldehyde as a novel polymer matrix resin. The silane-treated and untreated fibers along with polymer composites have been characterized by various techniques such as scanning electron microscopy (SEM), Fourier transform-infrared spectrophotometry (FT-IR) and thermogravimetric/differential thermal analysis along with DTG studies. Composites prepared were also subjected to the evaluation of different mechanical, physical, and chemical properties.
Article
Natural cellulosic pine needles were used in long fiber form as a new, potential reinforcement to fabricate green composites using the compression-molding technique. Mechanical and physico-chemical properties of green composites have been investigated as a function of fiber loading in order to assess their applicability in everyday life. The green composites fabricated showed a universal trend of increase in properties with fiber loading up to 30% and beyond this loading these properties decrease. Fiber/matrix interaction between the polymer and reinforcement has been analyzed from the mechanical and morphological studies, which reveal the impact of good interfacial compatibility.
Article
Composite materials are used in a wide range of applications such as automotive, aerospace and renewable energy industries. But they have not been properly recycled, due to their inherent nature of heterogeneity, in particular for the thermoset-based polymer composites. The current and future waste management and environmental legislations require all engineering materials to be properly recovered and recycled, from end-of-life (EOL) products such as automobiles, wind turbines and aircrafts. Recycling will ultimately lead to resource and energy saving. Various technologies, mostly focusing on reinforcement fibres and yet to be commercialized, have been developed: mechanical recycling, thermal recycling, and chemical recycling. However, lack of adequate markets, high recycling cost, and lower quality of the recyclates are the major commercialization barriers. To promote composites recycling, extensive R&D efforts are still needed on development of ground-breaking better recyclable composites and much more efficient separation technologies. It is believed that through the joint efforts from design, manufacturing, and end-of-life management, new separation and recycling technologies for the composite materials recycling will be available and more easily recyclable composite materials will be developed in the future.