The optical properties (absorption and fluorescence) of fluorescein sodium were investigated with changing the bulk pH value in aqueous, water-methanol mixed and dodecylammonium propionate reversed micellar solutions. A strong buffer action was found in the reversed micellar solutions. The pK a values for the equilibrium between fluorescein monoand di-anions in the ground and excited singlet st...

fluoride is recognized as an effective agent for dental caries prevention. generally, the main source of fluoride intake is drinking water. in this study, fluoride content in 18 commercial brands of bottled waters was investigated. six samples from each batch of 18 iranian commercial brands of bottled waters were supplied. the fluoride content of samples was analyzed by fluoride ion selective e...

A major contributor to degradation on rangelands in the western United States is the expansion of undesirable annual weeds following wildfire or other disturbance. The Simultaneous Heat and Water (SHAW) model was applied to three soil types (loamy sand, sandy loam, and silt loam) to simulate near-surface soil temperature and water for predicting potential seed germination in post-wildfire reveg...

The goal of this project is to develop an technique to measure the PM produced by a two-stage wood based boiler in an inexpensive manner while still preserving high degree of accuracy. The general idea involved in the process involves sampling of the exhaust gas using a vacuum pump. A filter paper with a permeability of 2μm is used to capture PM2.5 present in the exhaust. The sampled data is me...

Accurate characterization of near-surface soil water content is vital for guiding agricultural management decisions and for reducing the potential negative environmental impacts of agriculture. Characterizing the near-surface soil water content can be difficult, as this parameter is often both spatially and temporally variable, and obtaining sufficient measurements to describe the heterogeneity...

evaporation from the soil surface has an important role in the water balance model in nature, so that the major part of rain fall and irrigation water in arid and semi-arid regions is lost via evaporation from the soil surface. in such areas, there are some regions with high water table and because of evaporation from the soil surface, salts accumulation also occur in the soil surface. so evapo...

CONTEXT Bottled water has become a status symbol and is frequently used in place of tap water. While both waters are considered safe to drink, is either more beneficial in preventing tooth decay and is there a difference in purity? OBJECTIVE To determine the fluoride level and bacterial content of commercially bottled waters municipal tap water and to compare the results. DESIGN Comparative...