all analytical methods are generally based on the measurement of a parameter or parameters which are somehow related to the concentration of the species.an ideal analytical method is one in which the concentration of a species can be measured to a high degree precision and accuracy and with a high sensitivity. unfortunately finding such a method is very difficult or sometimes even impossible.in...

Copper is considered as one of the most important nutrient elements for plants. If its contents are concentrated higher than the standard value it can be considered as a pollutant element. The content of absorbable copper in the area around Sarcheshmeh copper mine can be significantly high. In this study, samples of soil were collected in summer through a particular sampling method with chimney...

bekenstein and hawking by introducing temperature and every black hole has entropy and using the first law of thermodynamic for black holes showed that this entropy changes with the event horizon surface. bekenstein and hawking entropy equation is valid for the black holes obeying einstein general relativity theory. however, from one side einstein relativity in some cases fails to explain expe...

Background and Objective: Heavy metals are the most frequent pollutants of urban soils. In general, human health and especially children are directly at risk if the soil is being accidentally ingested orally or nasally. Therefore, this study was conducted to assess potential ecological risk index (RI) of Pb, Cd, Cr and Cu in surface soils of urban parks in Tehran City in 2016. Materials and Me...

Tillage system effect, Conventional (CT) vs. No-Till (NT), on soil physical properties and Br transport was studied at two locations in North Carolina. The soil types were a Typic Paleudults at Coastal Plain (site 1) and a Typic Kanhapludults at Piedmont (site 2). Bulk density (BD), total porosity (TP), macroporosity (MP), and saturated hydraulic conductivity (Ks) .were measured in plant row (R...

Tillage system effect, Conventional (CT) vs. No-Till (NT), on soil physical properties and Br transport was studied at two locations in North Carolina. The soil types were a Typic Paleudults at Coastal Plain (site 1) and a Typic Kanhapludults at Piedmont (site 2). Bulk density (BD), total porosity (TP), macroporosity (MP), and saturated hydraulic conductivity (Ks) .were measured in plant row (R...

a novel silver (ag) nanocomposite electrode was proposed that fabricated from metal nanostructures and ionic liquids. the combined application of unique properties of nanomaterials and ionic liquids in the design of this ag nanocomposite results in electrodes with interesting advantages compared to the conventional metal disk electrode. in the first part of this thesis, the elecrocatalytic eff...

determination of uranium in natural water and complex solutions using ion exchange chromatography: a combined procedure using ion exchange chromatography and uv-vis spectrophotometry techniques has been developed to measure uranum in natural water and complex solutions. after conditicing , one hundred milli liters of sample solutions have been passed through an ion exchange column,pachked with ...