the effect of temperature on the adsorption of heavy metals on not only natural bulk clay, but also for the individual phases that composed the bulk clay sample, was investigated. combined adsorption- sequential extraction analysis (casa) for pb, cu, zn and cd were conducted under various temperatures that ranged from 150c to 550c. as a result, it was found that heavy metals adsorption for b...

this study was carried out to 1. determine spatial variations of heavy metal deposition in agricultural soils of two rural communities (ouledbouaicha and tazakourte) of about 5790 ha in a mining area near marrakech city in morocco; 2. to assess the extent of metallic pollution generated by the mining activity and; 3. to identify the key mechanism responsible for this contamination and its relat...

biomedical datasets usually include a large number of features relative to the number of samples. however, some data dimensions may be less relevant or even irrelevant to the output class. selection of an optimal subset of features is critical, not only to reduce the processing cost but also to improve the classification results. to this end, this paper presents a hybrid method of filter and wr...

The research presented in this article assessed geochemical factors relating to dust produced during primary lead smelting. Bulk dust samples and size-selective airborne dust samples were collected from four areas of a primary lead smelter and analyzed by X-ray diffraction and sequential chemical extraction. X-ray diffraction showed that the smelter dusts were composed primarily of sulfides, ox...

Inorganic thallium compounds in the atmospheric particulate matter of emissions and in the workplace air of specific industrial production can be determined through selective sequential extractions: Tl(I) is separated from Tl(0) and Tl(III) in the first step, Tl(0) in the second one, while in the final extraction both Tl(III) soluble and insoluble compounds are determined. The procedure has bee...

abstract zinc (zn) is an essential plant nutrient. knowledge about distribution of zn between its different chemical forms is useful in understanding the chemistry of this element in soil and also in development of soil testing procedures. the present study was conducted to obtain such information about distribution of zinc forms in 20 soil samples of lorestan province by the use of a sequentia...

a new carboxylic acid extractant, named 2-(dibutylcarbamoyl)benzoic acid, is prepared and its potential for selective solvent extraction and recovery of lead ions from industrial samples was investigated. the slope analysis indicated that the lead ions are extracted by formation of 1:2 metal to ligand complexes. the effect of the parameters influencing the extraction efficiency including kind o...

Aggregate signature schemes enable anyone to compress many signatures into one. Besides the unforgeability of aggregate signature, another property called extraction sometimes is useful. In sequential schemes, computed incrementally by signers. We introduce security in context which can be seen as an analogy introduced Boneh et al. CRYPTO 2003. addition practical meaning, it also has benefits c...

Many model selection algorithms produce a path of fits specifying a sequence of increasingly complex models. Given such a sequence and the data used to produce them, we consider the problem of choosing the least complex model that is not falsified by the data. Extending the selected-model tests of Fithian et al. (2014), we construct p-values for each step in the path which account for the adapt...