نتایج جستجو برای: hydrocarbons
تعداد نتایج: 26785 فیلتر نتایج به سال:
Crude oil is a complex mixture mainly composed of various saturated and aromatic hydrocarbons. Whereas degradation of hydrocarbons by oxygen-respiring microorganisms has been known for nearly one century, utilization of hydrocarbons under anoxic conditions has been investigated only during the past ten years. The present paper summarizes investigations into the anaerobic degradability of crude ...
During the course of a study of the effect of the oral administration of certain polycydic hydrocarbons on the growth of the rat,7 a paper by Haddow, Scott, and Scott2 appeared which reported that growth retardation had been produced in the rat by a single intraperitoneal injection of certain carcinogenic hydrocarbons. These authors further observed that similar injections of non-carcinogenic c...
the waste tyres represent a source of energy and valuable hydrocarbon products. waste tyres were pyrolysed catalytically in a batch reactor under atmospheric pressure. the effects of basic catalysts (mgo and caco3) were studied on the pyrolysis products. the distribution ratio of gas, liquid and char with mgo and caco3 were 24.4:39.8:35.8 wt % and 32.5:32.2:35.2 wt % respectively at 350°c for 2...
vehicle exhaust is a major source of exposure to polycyclic aromatic hydrocarbons (pahs) found in the urban atmosphere. newsagents usually work close to heavy traffic flow. the purpose of this study was to assess the breathing zone exposure of newsagents to pahs found in the urban atmosphere of tehran city during summer and autumn seasons and comparing the levels of exposure in both seasons.fif...
occurrence and diagenetic evolution of perylene in the sediments of oginigba creek, southern nigeria
perylene and penta-aromatic hydrocarbons were determined in sediments as part of a study that was dedicated to the aquatic ecosystem of oginigba creek (southern nigeria) in order to carry out a critical corroboration of occurrence and diagenetic evolution of perylene in the sediments of the creek. the results show that the annual mean levels of perylene ranged from 396.27– 507.19 mg/g dry wei...
polycyclic aromatic hydrocarbons (pahs) are toxic pollutants released by various urban combustion sources. tehran is the largest city in iran with a population of about 8 million and it is faced with serious air quality problems. the gas phase samples collected from 21 sites in tehran area throughout year 2005. the samples‘ pahs were collected using a skc trapping consisting of glass cartridg...
Many hypersaline environments are often contaminated with petroleum compounds. Among these, oil and natural gas production sites all over the world and hundreds of kilometers of coastlines in the more arid regions of Gulf countries are of major concern due to the extent and magnitude of contamination. Because conventional microbiological processes do not function well at elevated salinities, bi...
The causal relationship between food intake and hydrocarbon synthesis was examined in vivo and in vitro. Fed Blattella germanica (L.) nymphs synthesized hydrocarbons in a stage-specific manner, with high rates occurring in the first 6 days of a 13-day last stadium, in relation to feeding. A similar pattern was exhibited in vitro by sternites and tergites from fed nymphs. In contrast, starved ny...
In the laboratory, marine worms were fed with a mixture of algae and several aliphatic hydrocarbons for 15 days. By comparing hydrocarbons in food and in faeces, it appeared that the worm's digestive process led to changes in the distribution of the n-alkanes mixture. These changes were different from those only due to physical processes in the experimental conditions, indicating that marine wo...
The onset of human degenerative diseases in humans, including type 2 diabetes, cardiovascular disease, neurological disorders, neurodevelopmental disease and neurodegenerative disease has been shown to be related to exposures to persistent organic pollutants, including polychlorinated biphenyls, chlorinated pesticides, polybrominated diphenyl ethers and others, as well as to polynuclear aromati...
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