نتایج جستجو برای: chromium compounds

تعداد نتایج: 248683  

Journal: :Environmental Health Perspectives 1991
C Witmer

The Panel was asked questions that had been prepared prior to the conference as well as queries from the audience, as follows. In response to a question from R. Bartlett as to how Crvl can get past the digestive tract without being reduced, M. Costa (New York University Medical Center) stated that it is, in fact, likely reduced. He emphasized that the pharmacokinetics of chromium have not been ...

Journal: :FEMS microbiology reviews 2001
C Cervantes J Campos-García S Devars F Gutiérrez-Corona H Loza-Tavera J C Torres-Guzmán R Moreno-Sánchez

Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The hexavalent form of the metal, Cr(VI), is considered a more toxic species than the relatively innocuous and less mobile Cr(III) form. The presence of Cr in the environment has selected microbial and...

2013
Sachin Kumar Chandra

A development of prospective synthetic methods to produce Pyridine including those of complex structure will allow to makes the latter more available and hence Pyridine bases will be widely used in industry. In this paper the Hetrocyclization of Acetylenes with nitriles catalyzed by chromium Complex has been carried out. We have limited our aim to study the chromium catalyzed activation of bifu...

2017
Mohamad Alem Bouhassine Habib Boughzala

Potassium chromium aluminium diarsenate, KCr1/4Al3/4As2O7, was prepared by solid-state reaction. The structure consists of (Cr1/4/Al3/4)O6 octa-hedra and As2O7 diarsenate groups sharing corners to build up a three-dimensional anionic framework. The potassium cations are located in wide channels running along the c-axis direction. The crystal structure is isostructural with the triclinic AIMIIIX...

2000
GIUSEPPE GUBITOSA HANS H. BRINTZINGER

Tricarbonyl hydride derivatives of cyclopentadienyl-chromium, -molybdenum and -tungsten compounds covalently linked to a macroreticular polystyrene support are obtained by treatment of polystyrene-attached cyclopentadienyl anions with the respective metal hexacarbonyl and subsequent acidification. In contrast to the ease with which unsupported cyclopentaruenyl·chromium and -molybdenum tricarbon...

2006
R. Michalski

Chromium exists usually in the (III) or (VI) oxidation states. In contrast to Cr(III), which is essential to mammalian systems, Cr(VI) is dangerous for humans due to its toxicity and carcinogenic properties. Cr(VI) compounds are highly soluble, mobile and bioavailable compared to Cr(III) species. Chromium is usually analyzed using instrumental methods such as AAS or ICP, which are accurate and ...

Journal: :iranian journal of public health 0
abolfazl barkhordari 1. dept. of occupational health, faculty of health, shahid sadoughi university of medical sciences , yazd, iran. mohammad javad zare sakhvidi 1. dept. of occupational health, faculty of health, shahid sadoughi university of medical sciences , yazd, iran. fariba zare sakhvidi 1. dept. of occupational health, faculty of health, shahid sadoughi university of medical sciences , yazd, iran. gholamhossein halvani 1. dept. of occupational health, faculty of health, shahid sadoughi university of medical sciences , yazd, iran. ali firoozichahak 1. dept. of occupational health, faculty of health, shahid sadoughi university of medical sciences , yazd, iran. gholamabbas shirali 2. dept. of occupational health engineering, school of public health, ahvaz jundishapur university of medical sciences , iran.

welders exposure to nickel and hexavalent chromium in welding fumes is associated with increase of cancer risk in welders. in this study we calculated cancer risk due to exposure to these compounds in welders.the role of exposure parameters in welders on derived incremental lifetime cancer risk were determined by stochastic modeling of cancer risk. input parameters were determined by field inve...

Journal: :Environmental science and pollution research international 2016
Kołoczek Henryk Chwastowski Jarosław Żukowski Witold

Batch adsorption experiments were performed for the removal of chromium (III) and chromium (VI) ions from aqueous solutions using Canadian peat and coconut fiber. The Langmuir model was used to describe the adsorption isotherm. The maximum adsorption for peat reached 18.75 mg/g for Cr(III) and 8.02 mg/g for Cr(VI), whereas the value for fiber was slightly higher and reached 19.21 mg/g for Cr(II...

Journal: :Colloids and Surfaces A: Physicochemical and Engineering Aspects 2019

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