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391.
Ganie Showkat Ali Rather Luqman Jameel Li Qing 《Journal of Polymers and the Environment》2022,30(4):1284-1299
Journal of Polymers and the Environment - Polysaccharides are polymers of natural origin that are formed by microorganisms, animals and plants. Polysaccharides play an important part in the... 相似文献
392.
Biswas Manik Chandra Jony Bodiuzzaman Nandy Pranab Kumar Chowdhury Reaz Ahmed Halder Sudipta Kumar Deepak Ramakrishna Seeram Hassan Masud Ahsan Md Ariful Hoque Md Enamul Imam Muhammad Ali 《Journal of Polymers and the Environment》2022,30(1):51-74
Journal of Polymers and the Environment - Recently, the advantages of biopolymers over conventional plastic polymers are unprecedented, provided that they are used in situations in which they raise... 相似文献
393.
Jawad Ali H. Abdulhameed Ahmed Saud Kashi Elmira Yaseen Zaher Mundher ALOthman Zeid A. Khan Mohammad Rizwan 《Journal of Polymers and the Environment》2022,30(1):164-178
Journal of Polymers and the Environment - Kaolin clay (KN) was employed as an inorganic filler to modify a cross-linked chitosan-glyoxal as Schiff’s-based chitosan composite derivative... 相似文献
394.
Fahime Abedini Seyed Ali Hosseini Aligholi Niaei Dariush Salari Milad Abbasi Shiva Marmarshahi 《International Journal of Green Energy》2018,15(1):20-27
The paper reports the production of syngas from dry reforming of methane (DRM) over La1?xCexNi1?yFeyO3 (x, y = 0–0.4) perovskites. A series of La1?xCexNi1?yFeyO3 were designed by central composite design (CCD) and synthesized by a sol–gel auto combustion method. Artificial neural network (ANN) approach was used to determine the relationship between preparation and operational parameters on the performance of the catalysts in the DRM process. Nickel mole fraction, lanthanum mole fraction, calcination temperature, and reaction temperature were considered as input variables, and conversion of methane was considered as the output variable. An ANN model with nine neurons in the hidden layer was the suitable in predicting conversion of methane. The genetic algorithm (GA) was subsequently used to determine the optimal preparation condition for enhancing the conversion of methane. La0.6Ce0.4Ni0.99Fe0.01O3 catalyst, calcined at 756°C was obtained to be the most active catalyst owing to the optimal composition of nickel and lanthanum in the catalyst formulation. 相似文献
395.
Richard J. Martin Ali Reza Larry W. Anderson 《Journal of Loss Prevention in the Process Industries》2000,13(6):491-497
After a large property loss, the insured and insurers of a hydroelectric power plant in North America became embroiled in subrogation to determine if the event could be characterized as an explosion. The subject insurance policy provided coverage for explosions, but excluded mechanical breakdowns. Analysis by Exponent Failure Analysis Associates indicated that a consistent, cross-disciplinary definition for explosions can be extracted from published scientific literature, and that this incident was not an explosion because certain key requirements were missing during the accident. However, this investigation has highlighted the necessity for insurance companies and their insureds to better understand this term and thereby minimize future coverage disputes. This paper presents an analysis of this incident and describes the necessary characteristics of an explosion. 相似文献
396.
Organic reactions in aqueous media are being developed because water is environmentally benign. The Horner–Wadsworth–Emmons reaction is a modified Wittig reaction for the synthesis of α,β-unsaturated ketones and other conjugated compounds. Here we prepared high molecular weight ketones by the Horner–Wadsworth–Emmons reaction of dimethyl-2-oxopropylphosphonate and various aldehydes in water at room temperature. The product was precipitated during the reaction process and was separated readily by a simple filtration in 90–99 % yield. 相似文献
397.
The oxidation of alcohols and alkenes to aldehydes, ketones and epoxides is a major reaction in organic synthesis, but is usually hard to perform due to the lack of efficient methods. The use of ultrasounds may improve yield because ultrasonic-assisted reactions are often more efficient than traditional methods. Here, we prepared a hybrid chromium(VI)-based magnetic nanocomposite catalyst by co-precipitation. This catalyst was characterized by Fourier transform infrared, solid-state ultraviolet–visible, elemental analysis, X-ray fluorescence, scanning electron microscopy, X-ray diffraction and vibrating sample magnetometer analyses. The catalytic activity was tested by the oxidation of benzyl alcohol to benzaldehyde, cyclohexanol to cyclohexanone, and epoxidation of cyclohexene, using hydrogen peroxide at room temperature under ultrasonic irradiation. Results show conversions ranging from 27 to 100 % according to gas chromatography–mass spectrometry. This is the first report of using magnetic nanocomposites with ultrasonic irradiation for oxidation reactions. 相似文献
398.
Shakir Ali Sachin Kumar Thakur Aditya Sarkar Shashank Shekhar 《Environmental Chemistry Letters》2016,14(3):291-315
Fluoride contamination in water is a major problem across the globe, with health hazards such as dental and skeletal fluorosis. Most earlier studies are confined to local or regional scales. As the problem has serious socioeconomic implications, there is a need for a global perspective. Thus, here we review worldwide research for nearly a century on fluoride contamination in water. We investigated the distribution of fluoride contamination in water, its sources, mobilization and association. The major findings are: (1) Anomalous fluoride concentration in groundwater is mainly confined to arid and semiarid regions of Asia and North Africa. (2) The geogenic sources of fluoride in water are mainly fluorine-bearing minerals in rocks and sediments, whereas anthropogenic sources of fluoride in water are mainly pesticides and industrial waste. (3) Fluoride mobilization from geogenic sources is mainly controlled by alkalinity and temperature. (4) Fluoride occurrence in water is associated with ions such as sodium, arsenic chloride and bicarbonate. There are few associations of fluoride in water with calcium and magnesium. 相似文献
399.
The study of heavy metals’ redistribution between different fractions allows to know their bioavailability and mobility in soils. Soil samples were collected from a lead mine in Hamadan provinces, NW Iran. In a factorial experiment soil was treated with cow, sheep and poultry manures (20?g?kg?1 soil) separately and incubated near field capacity at 10°C and 37°C. An untreated soil (as control) was also incubated at the same temperatures. After 0 and 120 days, a sequential extraction scheme was used to fractionate Pb of incubated samples into soluble-exchangeable (Sol-Exch), organic matter associated (AOM), carbonates associated (ACar), and residual (Res) forms. Soil Pb in Sol-Exch and AOM fractions were increased by manure application significantly. The AOM and ACar forms of Pb were higher in soils treated with the manures and incubated in lower temperature. In contrast, the Sol-Exch and Res chemical forms of Pb were higher in the soils incubated at 37°C. These results may be related to the higher calcium carbonate dissolution and organic matter decomposition because of better biological activity in the soils incubated in higher temperature. The increase of the Res fraction (stable form) in this condition may resulted in lower toxicity and mobility in soil environment. 相似文献
400.
When juvenile mortality or juvenile growth is impacted by temperature and salinity, these factors have a substantial effect on recruitment success and population dynamics in benthic ecosystems. Using freshly settled cyprids of Amphibalanus improvisus, we investigated the combined effects of temperature (12, 20 and 28 °C) and salinity (5, 15 and 30 psu) on early juvenile stage performance. Mortality as well as size (basal diameter, dry weight, and ash-free dry weight) was monitored for a period of 40 days. Mortality was high (42–63 %) during the first week following attachment, regardless of the temperature and salinity treatments. Subsequently, mortality and size were interactively influenced by temperature and salinity. Highest mortality and lowest size of juveniles occurred at lowest temperature (12 °C) and salinity (5 psu). Apparently, low temperature (12 °C) narrowed the barnacles’ salinity tolerance. Juvenile barnacles constructed more shell material compared to body mass at high temperature and high salinity, while a reverse situation was observed at low temperature and low salinity. Our results demonstrate that environmental changes can directly and/or indirectly alter patterns of survivorship and size. Warming and desalination as predicted for the Baltic Sea in the course of climate change may, however, act antagonistically and compensate each other’s isolated effect on barnacles. 相似文献