The adsorption properties of various sorbent materials were investigated to assess the factors affecting biases in the sorbent tube (ST) sampling of airborne phthalates. The recovery of phthalates was assessed critically in relation to four key sampling parameters: (1) three types of sorbent materials (quartz wool (QW), glass wool (GW), and quartz wool plus Tenax TA (QWTN)), (2) the concentrati...

INTRODUCTION During hygienic-microbiological monitoring of the water quality in dental units, the total bacterial colony count was found to exceed the limits for drinking water quality; in addition, mold contamination was detected. The presumed cause was irregular decontamination of the units through purging and intensive decontamination. METHODS To decontaminate the units, the manufacturer's...

OBJECTIVE The effects of aging and freezing/thawing sequence on color, physicochemical, and enzymatic characteristics of two beef muscles (Mm. gluteus medius, GM and biceps femoris, BF) were evaluated. METHODS Beef muscles at 3 d postmortem were assigned to four different combinations of aging and freezing/thawing sequence as follows; aging at 2°C for 3 wk (A3, never-frozen control), freezing...

Plant genome size variation is a dynamic process of bloating and purging DNA. While it was thought plants were on a path to obesity through continual DNA bloating, recent research supports that most plants activity purge DNA. Plant genome size research has greatly benefited from the cataloguing of genome size estimates at the Kew Plant DNA C-values Database, and the recent availability of over ...

Abstract Why do dictators purge specific elites but not others? And why these in certain ways? Examining related questions helps us understand only how retain sufficient competence their regimes to alleviate popular and foreign threats, also nullify elite threats. Dictators are more likely first-generation elites, who powerful because they can negotiate role from a position of strength possess ...

The desorption kinetics of hexachlorobenzene (HCB) and 2,4,4'-trichlororbiphenyl (PCB 28) spiked to a field sediment were studied using a gas-purge technique. A contact time of up to 1,461 d was used to assess long-term changes in desorption kinetics. Purge-induced desorption experiments lasted from 300 to more than 4,000 h. Fast-, slow-, and very-slow-desorbing fractions could be distinguished...

We present a transient Boltzmann equation based transport and reaction model for atomic layer deposition ~ALD! at the feature scale. The transport model has no adjustable parameters. In this article, we focus on the reaction step and the postreaction purge steps of ALD. The heterogeneous chemistry model consists of reversible adsorption of a reactant on a single site, and irreversible reaction ...

Static headspace analysis can provide reasonably good sensitivity for halogenated hydrocarbons and aromatic compounds. But USEPA Method 524.2 Revision 4 requires the evaluation of several analytes containing different functional groups such as ketones, ethers, and esters. Such compounds can be particularly difficult to analyze at low concentration using static headspace due to the affinity of p...

The commercial proton exchange membrane fuel cell (PEMFC) system needs to be equipped with the capacity survive a harsh environment, including sub-freezing temperatures. cold start of PEMFC brings about great technical challenges, mainly due ice blockage in components, which seriously hinders multi physical transmission process. A multiscale, two-dimensional model was established explore gas pu...