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...

Knowledge of the probable origin and behaviour of arsenic certainly gives valuable insights into the potential for transfer in the environment and of the risks involved in mining sites. Sequential extraction analyses are common experiments often used to study the origin and behaviour of potentially toxic elements. The method, however, presents some deficiencies, including labor-intensive proced...

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...

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...

Selective Sequential Extractions (SSE) were used to study the retention mechanisms of heavy metals on three estuarine alluvium soil columns obtained from leaching experiment for up to 5 pore volumes (PV). Leaching results indicate that almost 99 % of heavy metals (Pb, Cu, and Zn) were retained in the soils with the Ce/Co values in the order of 10 -3 to 10. This is in accord with the results obt...

Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) extracted by Soxhlet extraction (S-PAHs) with dichloromethane and routine accelerated solvent extraction (A-PAHs) with 1:1 toluene/methanol, respectively, were investigated in 24 soil samples from two cities in the center of the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons, methylphenanthrene and perylene, in two...

The knowledge of the application behavior allows predicting the application workload during its execution and forecasting distributed data accesses. In order to obtain such data, different strategies can be employed, varying from simple source code analysis, sequential access pattern extraction (Kotz & Ellis, 1993), history-based approaches (Gibbons, 1997; Smith, Foster & Taylor, 1998) and on-l...