نتایج جستجو برای: perchlorate

تعداد نتایج: 3341  

2008

Commercial interest in perchlorates began in the late 1890s/early 1900s in Europe and the United States as a direct result of the pioneering efforts in rockets and their propulsion systems (Mendiratta et al. 1996). The production of ammonium perchlorate, the largest component of solid rocket propellants, far outpaced that of the other perchlorates listed in Table 4-1. Their commercial manufactu...

2013
Ryan A. Melnyk Iain C. Clark Annette Liao John D. Coates

UNLABELLED Although much work on the biochemistry of the key enzymes of bacterial perchlorate reduction, chlorite dismutase, and perchlorate reductase has been published, understanding of the molecular mechanisms of this metabolism has been somewhat hampered by the lack of a clear model system amenable to genetic manipulation. Using transposon mutagenesis and clean deletions, genes important fo...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2009
Masahiro Kamoshita Koji Kosaka Mari Asami Yukiko Matsuoka

A practical analytical method was developed for the routine analysis of perchlorate in environmental and drinking-water samples by liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS) using an anion exchange column. By using (18)O-enriched perchlorate as an internal standard, the limits of quantification of perchlorate determined by tenfold of the signal-to-noise ratio an...

2010
D. C. Catling M. W. Claire K. J. Zahnle R. C. Quinn B. C. Clark M. H. Hecht S. Kounaves

[1] Isotopic studies indicate that natural perchlorate is produced on Earth in arid environments by the oxidation of chlorine species through pathways involving ozone or its photochemical products. With this analogy, we propose that the arid environment on Mars may have given rise to perchlorate through the action of atmospheric oxidants. A variety of hypothetical pathways can be proposed inclu...

Journal: :Environmental science & technology 2005
C A Sanchez K S Crump R I Krieger N R Khandaker J P Gibbs

In previous studies trace levels of perchlorate were found in lettuce (Lactuca sativa L.) irrigated with Colorado River water, which is contaminated with low levels of perchlorate from aerospace and defense related industries. In this paper, we report the results of a survey conducted across North America to evaluate the occurrence of perchlorate in leafy vegetables produced outside the lower C...

2001
DIMITRI R. KIOUSSIS DANIEL F. SMITH PETER KOFINAS

Systems that are capable of removing highly toxic anions from wastewater effluents, even at extremely low concentrations, are a major need in the defense industry. This study reports on the features of two new batch and continuous-flow sorption processes with regard to ultimate removal and recovery of the perchlorate (ClO4 ) anion from ammonium perchlorate (NH4ClO4) wastewater. The sorbent deve...

2005
Franco Scinicariello H. Edward Murray Lester Smith Sharon Wilbur Bruce A. Fowler

Perchlorate has been detected in groundwater in many parts of the United States, and recent detection in vegetable and dairy food products indicates that contamination by perchlorate is more widespread than previously thought. Perchlorate is a competitive inhibitor of the sodium iodide symporter, the thyroid cell-surface protein responsible for transporting iodide from the plasma into the thyro...

Journal: :Analytica chimica acta 2006
C A Sanchez R I Krieger N R Khandaker L Valentin-Blasini B C Blount

Citrus produced in the southwestern United States is often irrigated with perchlorate-contaminated water. This irrigation water includes Colorado River water which is contaminated with perchlorate from a manufacturing plant previously located near the Las Vegas Wash, and ground water from wells in Riverside and San Bernardino counties of California which are affected by a perchlorate plume asso...

Journal: :FEMS microbiology letters 2004
Yanguang Song Bruce E Logan

The effect of low concentrations of cyanide on dissimilatory perchlorate and chlorate reduction and aerobic respiration was examined using pure cultures of Azospira sp. KJ. Cyanide at a concentration of 38 microM inhibited cell growth on perchlorate, chlorate and molecular oxygen, but it did not inhibit the activity of chlorite dismutase. When oxygen accumulation was prevented by adding an oxyg...

Journal: :Environmental science & technology 2007
Naomi Lubick

that disrupts thyroid function by inhibiting the uptake of iodide, is best known for its use in rocket fuel but also occurs naturally in the environment. Since the beginning of the last century, Chilean nitrate fertilizers that contained naturally produced perchlorate were applied to U.S. agricultural fields. Today, perchlorate hot spots occur, some of which seem to extend farther than what is ...

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