Heavy metals are normally occurring elements that have a density at least 5 times higher than of water. Their plentiful domestic, industrial, agricultural and technological usages have led to their widespread distribution in the environment; raising worries over their possible impacts on human health and the environment. The toxicity of heavy metals relies on numerous factors including the dose...

We undertook detailed examination of the practices and procedures involved in the analysis of serum for zinc by atomic absorption spectrophotometry, to identify possible sources of zinc contamination. Some degree of contamination was found in almost all steps of the procedure. These findings are presented and alternative materials and procedures are described that significantly decrease or elim...

the contents of as, cd, cu and mo were determined in soil surrounding meyduk tailings dam based on 21 surface soil samples. assessment of toxic element pollution in studied soil samples needs knowledge of pre-anthropogenic metal concentration to act as a reference against which measured values could be compared. estimating the background values was executed by sampling rocks adjacent to soil s...

the probability that the commutator of two group elements is equal to a given element has been introduced in literature few years ago. several authors have investigated this notion with methods of the representation theory and with combinatorial techniques. here we illustrate that a wider context may be considered and show some structural restrictions on the group.

to assess the sources, entry routes and degree of contamination of pah compounds in surface sediments of the southwestern caspian sea coasts (gillan province) total of 129 surface sediment samples from 28 rivers and 5 transect across the gillan province coasts (from astara to lahijan; 10, 20 and 50 m depth) were collected in the spring and summer of 2012. after extraction using soxhlet method, ...

Recent research on mental contamination (internal, psychological feelings of dirtiness) has focused primarily on examining the experimental variables necessary to provoke contamination-related thoughts, feelings and behaviour; yet, relatively little is known regarding the individual differences among participants' mental contamination responses to these situational and experimental characterist...

........................................................................................................................2 INTRODUCTION...............................................................................................................3 THE NATIONAL MAIZE ECONOMY.............................................................................4 GUATEMALA’S AGRICULTURE AND MAIN MAIZE PRODUC...

A study was performed to investigate and compare the relative performance of blind signal separation (BSS) algorithms at separating common types of contamination from EEG. The study develops a novel framework for investigating and comparing the relative performance of BSS algorithms that incorporates a realistic EEG simulation with a known mixture of known signals and an objective performance m...