design and optimization of a single crystalline silicon (c-si) solar cell is performed to achieve the maximum light conversion efficiency. various parameters such as doping concentration and thicknesses, and geometrical dimension of surface pyramids are studied. the inverted surface pyramid is used to increase the efficiency of the solar cell, and engineered oxide layer is used as the passivati...

background: due to the increasing pollution of water resources, this study was carried out for evaluation of water quality pollution indices for monitoring of heavy metals (as, zn, pb and cu) contamination in ghahavand plain, hamadan province, western iran during spring and summer 2012. methods: totally, 20 ground water wells were chosen randomly. the samples were filtered (0.45 μm) and maintai...

background: iran is located within the dry and semi dry regions, thus almost 90% of the required water is secured via the use of groundwater. owing to the increasing pollution of water resources, this study was performed to evaluate water quality pollution indices for heavy metals (as, zn, pb and cu) contamination monitoring in toyserkan plain during spring and summer in 2012. methods: a total ...

an ex-situ experiment to assess the metal extractive potential of fourteen agriculture plants (vigna unguiculata, gossypium hirsutum, jatropha curcas, etc.) was conducted on magnesite mines which had above permissible levels of cadmium and lead. there was no much difference in the total chlorophyll a and b, carbohydrate and protein contents in the plants grown in the mining soil and adjacent co...

Background: Due to the increasing pollution of water resources, this study was carried out for evaluation of water quality pollution indices for monitoring of heavy metals (As, Zn, Pb and Cu) contamination in Ghahavand Plain, Hamadan Province, Western Iran during spring and summer 2012. Methods: Totally, 20 ground water wells were chosen randomly. The samples were filtered (0.45 μm) and m...

BACKGROUND This study aimed to develop an index that can rank welding workplace that associate well with possible health risk of welders. METHODS Welding Fumes Health Index (WFHI) were developed based on data from case studies conducted in Plant 1 and Plant 2. Personal sampling of welding fumes to assess the concentration of metal constituents along with series of lung function tests was cond...

The study evaluated eight heavy metals content and soil pollution from agricultural soils in northern China. Multivariate and geostatistical analysis approaches were used to determine the anthropogenic and natural contribution of soil heavy metal concentrations. Single pollution index and integrated pollution index could be used to evaluate soil heavy metal risk. The results show that the first...

Metal-based negative refractive-index materials have been extensively studied in the microwave region. However, negative-index metamaterials have not been realized at near-IR or visible frequencies due to difficulties of fabrication and to the generally poor optical properties of metals at these wavelengths. In this Letter, we report the first fabrication and experimental verification of a tran...