a mixed solar dryer with a specific mechanism to vary the tilted angle of collector, is utilized to fulfill all tests. the efficiency of the dryers is low because of various reasons such as heat loss of air in an open flow circuit. getting air back toward the air inlet of dryer can increase the efficiency of dryer and decrease drying process period. a new mechanism considered for dryer which co...

abstract appearance of tomato used for preparing dried halves tomato and retention its colour during storage are very important factors. in order to study the physicochemical properties (brix, acidity, ph, moisture, average length, average diameter and the ratio of length over diameter), five different varieties of tomato (kural, riyogrande, pilow and pep) were selected. the experiment was desi...

A novel spectrophotometric method for the estimation of carbon monoxide at levels from 2 to 250 ppm is presented. The method is empirical and based on formation of a carbonyl complex of ruthenium(II) octaethylporphyrin and measurement of the difference in absorbance at 393.5 nm between this complex and the porphyrin reagent. Oxygen and nitrogen do not interfere and up to 300 ppm of sulphur diox...

Natural gas is considered the cleanest and recently the most abundant fossil fuel source, yet when it is extracted from wells, it often contains 10-20 mol% carbon dioxide (20-40 wt%), which is generally vented to the atmosphere. Efforts are underway to contain this carbon dioxide at the well-head using inexpensive and non-corrosive methods. Here we report nucleophilic porous carbons are synthes...

We studied flow rate, electrolytes effects, titanium dioxide separation and reuse and sunlight application on photocatalysis in a tubular photoreactor integrated with the titanium dioxide separation/reuse. The circulative flow treatment was preferred over the single pass treatment. Phenol and TOC removals in tap and deionized waters were a maximum at the circulative flow rate of 600 ml min and ...

The removal of xylene vapors was studied in a biofilter packed with a new hybrid (scoria/compost) packing material at various inlet loads (IL) and empty bed residence times (EBRT) of 90, 60, and 40s. The best performance was observed for EBRT of 90s, where a removal efficiency of 98% was obtained under steady state condition for inlet xylene concentration of 1.34 g m(-3), while a maximum elimin...

BACKGROUND Air pollution is associated with cardiovascular mortality. Changes in the autonomic nervous system may contribute to cardiac arrhythmias and cardiovascular mortality. This study investigated the relations between air pollutant concentrations of sulphur dioxide (SO(2)), ozone (O(3)), nitric dioxide (NO(2)), and resting heart rate (RHR) in a population based study. METHODS A sample o...

in the present paper, the flow and heat transfer of two types of nanofluids, namely, silver-water and silicon dioxide-water, were theoretically analyzed over an isothermal continues stretching sheet. to this purpose, the governing partial differential equations were converted to a set of nonlinear differential equations using similarity transforms and were then analytically solved. it was found...