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Handbook of Environmental Degradation of Materials,
The polymer industry developed as population growth created, increased demands for natural products that could not readily be met because of their limited supplies. The explosion of knowledge about polymers and the application of that knowledge to technology have occurred in the areas of both synthetic and naturally occurring polymer. The aim of this study was to find out the influence of different types of stabilizers; UV-Absorber, Carbon Black, and Titanium Dioxide, on the photo and thermal degradation mechanism of two different grades of polyethylene.
Sisson Adam Handbook of Biodegradable Polymers. Isolation, Synthesis, Characterization and Applications
A comprehensive overview of biodegradable polymers, covering everything from synthesis, characterization, and degradation mechanisms while also introducing useful applications, such as drug delivery systems and biomaterial-based regenerative therapies. An introductory section deals with such fundamentals as basic chemical reactions during degradation, the complexity of biological environments and experimental methods for monitoring degradation processes. The result is a reliable reference source for those wanting to learn more about this important class of polymer materials, as well as scientists in the field seeking a deeper insight.
Biodegradation of paranitrophenol (PNP) was carried out using Pseudomonas pseudomallei capable for PNP degradation. For enhanced biodegradation this strain was subjected to UV ray, chemical and gamma ray mutagenesis. UV and chemical mutagenesis was not fruitful as no PNP hyper degrading bacterial strain was obtained. Gamma ray mutagenesis was positive for PNP degradation and hyper degrading bacterial strain was obtained. Both parent and mutant in presence of glucose, efficiently degraded PNP. When concentration of glucose increased from 50 to 100 ppm then 50 ppm PNP was degraded within 12 hours by mutant and in 20 hours by parent. So glucose had positive effect on PNP degradation and resulted in enhanced PNP degradation. Effect of phenol was also checked on PNP degradation. The result showed that immobilization of the bacterial culture was best practice for PNP degradation. Similarly addition of glucose helped enhanced PNP degradation and ammonium sulphate provided good nitrogen source. After this toxicity of treated and untreated PNP was also checked by exposing to fish, that showed that after degradation of PNP no toxic metabolites were produced.
Degradation of rivers in the urban areas has become a serious problem around the world. Though the causes leading to river degradation are diverse, disposal of solid and liquid waste, encroachment upon the river waterway and water extraction are some of the obvious causes of river degradation. The studies focusing on river degradation often limit the area of inquiries to the assessment of changes in the river hydrology, morphology and water quality. While these assessments are important, it is also immensely important to look into the consequences of river degradation- who are affected, how and to what extent? This study was carried out with the aim of evaluating the factors and processes leading to the degradation of Hanumante River and the cultural, religious and livelihood consequences therefrom and the adaptation of people depending on river for their livelihood.
High-pressure liquid chromatography (HPLC) used in the analytical development to quantify the biological sample concentration, the active pharmaceutical ingredient (API) and to evaluate the impurity and degradation product profiles of the drug substances (DS) and drug products (DP). Additional uses of HPLC include determination of content uniformity of dosage form, monitoring of dissolution profiles, determination of antioxidants and preservative content and supporting of cleaning validations. UV spectroscopy is one of the most frequent used techniques in pharmaceutical analysis. It involves the measurement of UV radiation absorbed by a substance in solution. The wavelength range of UV radiation is 200-400nm (180-380 nm) and the UV radiation has a sufficient energy to excite valance electrons in many atoms or molecules; consequently, UV is involved with electronic excitation.
Photo-Degradation of Chlorophenols (CPs) in aqueous solution by UV/Fenton's reagent (Fe2+ and H2O2) was investigated in the present study. Experiments were conducted in a batch reactor, at pH 3.5 for 2-CP and pH 4 for 2,4-DCP and at 27±3°C with a source of UV light. The effects of different reaction parameters such as initial 2-CP and 2,4-DCP concentration, pH of solution, iron concentration, hydrogen peroxide concentration, on the oxidative degradation of selected chlorophenols were investigated. Final concentration, pH and COD of the solution after treatment were determined to know degree of the degradation of the compound. The optimum conditions established during Fenton's oxidation without UV, were used for this study. This method proved more efficient to Fenton's oxidation in degradation of 2-CP and 2,4-DCP. Further iron extracted from laterite soil showed better removal efficiency than ferrous sulfate salt and also to be cost effective with reduction in reaction time to three hours.
Poverty, malnutrition, low agricultural productivity, severe land degradation, shortage of water and fuel wood are common problems in the highlands of Ethiopia. A complex set of natural, political, and socio- economic factors have been responsible for the degradation of land resources. This study was conducted to characterize the nature of land use practices, nature and extent of land degradation in the highlands, assess the causes of land use change and land degradation, identify knowledge gaps and some options about the possible pathways of overcoming the problems and improve agricultural productivity. This study shows that the perspectives of local communities and households about the dynamics of land use, management and the degradation process and possible solutions are very useful and practical contribution to the research, extension and policy making community as well as the generality of citizens in the region.
The embroideries were one of the most sumptuous kinds of textiles produced in the world. Metal threads in historic embroideries textile deteriorate over time and corrode due to chemical attack by different corrosive factors such as high and fluctuating relative humidity, air pollutants and elevated temperatures. Handbook of Historic Embroidery Textiles Conservation, Principals and practical application will present extensive study of historic embroideries conservation strategy. Furthermore, it will facilitate understanding of degradation process, corrosion process, textiles conservation treatment, the behavior of object during these treatments, and analysis of historic textiles. Also, this book will present physical and chemical properties of natural fiber and metallic threads that used in historic embroideries textiles. This book will present practical application of historic embroideries textiles. By this information it will be easier for the conservators to make decisions, plain of conservation, and select material for conservation.
Nitrated Aromatic Compounds (NACs) are being used in bomb blast activities. They are highly acute and toxic in nature causing serious environmental and health issues like skin and eyes diseases, liver malfunction and tumor formation. Now a day, degradation of explosive compounds is a big issue. A solvent controlled synthesis of metal oxides nanoparticles was done using hydrothermal method. The nanoparticles were characterized by using Scanning Electron Microscope (SEM), Energy dispersive X-ray microanalysis (EDX), Transmission Electron Microscope (TEM) and Fourier transform infrared spectroscopy (FTIR), Thermo gravimetric Analysis (TGA) and X- Ray Diffraction (XRD). The catalytic effect of metal oxides nanoparticles were studied by degradation of Nitrated Aromatic Compound using spectrophotometric method in presence of UV-light. Degradation was also confirmed by High Performance Liquid Chromatography (HPLC) and Gas-Chromatography Mass Spectrometer (GC-MS).
The Oxford Handbook of International Organizations provides an authoritative account of the law and politics of international organizations. Looking at the role, function, and history of organizations, this Handbook offers a wide ranging and thorough analysis of the area.
Organic photovoltaics (OPV) are a new generation of solar cells with the potential to offer very short energy pay back times, mechanical flexibility and significantly lower production costs compared to traditional crystalline photovoltaic systems. A weakness of OPV is their comparative instability during operation and this is a critical area of research towards the successful development and commercialization of these 3rd generation solar cells. Covering both small molecule and polymer solar cells, Stability and Degradation of Organic and Polymer Solar Cells summarizes the state of the art understanding of stability and provides a detailed analysis of the mechanisms by which degradation occurs. Following an introductory chapter which compares different photovoltaic technologies, the book focuses on OPV degradation, discussing the origin and characterization of the instability and describing measures for extending the duration of operation. Topics covered include: Chemical and physical probes for studying degradation Imaging techniques Photochemical stability of OPV materials Degradation mechanisms Testing methods Barrier technology and applications Stability and Degradation of Organic and Polymer Solar Cells is an essential reference source for researchers in academia and industry, engineers and manufacturers working on OPV design, development and implementation.