نتایج جستجو برای: eavy metals
تعداد نتایج: 63798 فیلتر نتایج به سال:
Spin relaxation of conduction electrons in metals is significantly influenced by the Fermi surface topology. Electrons near Brillouin zone boundaries, special symmetry points, or accidental degeneracy lines have spin flip rates much higher than an average electron. A realistic calculation and analytical estimates show that these regions dominate the spin relaxation, explaining why polyvalent me...
A variety of metals have been implicated in carcinogenesis in both animal and human studies. It is our purpose here to consider possible molecular mechanisms for the induction of cancer, not only by already identified metal carcinogens, but also by metal ions generally. The reason for this approach is that present knowledge ofhuman metal carcinogens has come about haphazardly, as a result of ef...
One of the main current concerns regarding soil quality is the presence of trace metals that constitutes a risk of toxicity for plants and animals [1, 5, 7, 11]. Trace metals in soils can have either a lithogenic origin when they inherit from the lithosphere or an anthropogenic origin when they result from man’s activities (mining, metallurgy of non-ferrous metals, combustion of fossil energy s...
In this paper, ultrasonic properties like ultrasonic attenuation, sound velocities, acoustic coupling constants and thermal relaxation time have been studied in hexagonal structured metals Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er) and Thulium (Tm) along unique axis at room temperature. For the evaluations of ultrasonic properties, secondand thirdorder elastic con...
Microalgae are a source of numerous compounds that can be used in many branches of industry. Synthesis of such compounds in microalgal cells can be amplified under stress conditions. Exposure to various metals can be one of methods applied to induce cell stress and synthesis of target products in microalgae cultures. In this review, the potential of producing diverse biocompounds (pigments, lip...
industrial processes release a range of gaseous and particulate pollutants containing heavy metals into the air. lack of enough attention to the design, installation, repair and maintenance of gas and dust filtration systems in industries, is one of reasons of increasing the emissions of these pollutants. hereon, the steel making processes is one of emission sources of heavy metals. according t...
heavy metals are highly poisonous in the environment, even in small quantities, and endanger certain species and all live beings. current methods of removing heavy metals from aqueous media include chemical sequestration, ion exchange, surface absorption, membrane processes, oxidation and revival procedures which have high investment and exploitation costs. hence, it is significantly necessary ...
metals concentrations in lumbricus terrestris and soil samples from the dumpsites located in zaria metropolis, nigeria were measured spectrophotometrically. mean metal content in dumpsite soils were: 25.95 - 75.17, 8.33 - 382.94, 124.84 - 206.96, 34.24 - 666.67 and 111.11 - 488.10mg/kg for cd, cu, mn, pb and zn respectively. while the concentration ranges recorded in l. terrestris samples were;...
background: heavy metals contaminated environment constitutes a serious problem for human and other organisms. moreover, metals such as cd, pb, and cr are toxic metals. therefore, the purpose of this study was to evaluation of cd, pb, and cr in the muscle of cow, calf, and sheep slaughtered in sanandaj city from iran. methods: this was a descriptive cross-sectional study in sanandaj city in nov...
background foods are enriched with variety of chemical elements. some of these elements are necessary for human health. these elements enter in liquid, the cells and other organs, certain amount of these elements are essential for body organs to work properly. objectives this research was conducted to compare the level of lead and cadmium contamination in garlic species planted in ramhormoz and...
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