We present a mathematical model for the laser surface hardening of steel. It consists of a nonlinear heat equation coupled with a system of ve ordinary diierential equations to describe the volume fractions of the occuring phases. Existence, regularity and stability results are discussed. Since the resulting hardness can be estimated by the volume fraction of martens-ite, we formulate the probl...

The quality and shelf life of foods of containing lipids (fats and oils) significantly reduces due to rancidity.Applications of natural antioxidants are one of the most effective manners to prevent the oxidation of oils and lipids. The antioxidant properties of juice extracted from barberry fruit (Berberris vulgaris.L) using maceration and SWE (10 bars and 120 180°C) methods were investigated a...

The performance of a photovoltaic (PV) array depends on temperature, radiation, shading and load size. Conventional maximum power point tracking (MPPT) methods have acceptable efficiencies under uniform conditions (irradiance = 1000 W/m2 temprature 25 °C), but in dynamic weather conditions, changes, also partial due to the presence several local points (MPP) P-V characteristic...

pectinases have multiple nature and various forms which are necessary for the hydrolysis of pectin in several conventional industrial and natural processes. in this investigation fourteen fungal strains which isolated from agricultural soils ,were screened for pectinase activity. pectinase activity were measured in vitro by assaying released reducing sugar from pectin as sole carbon source. asp...

A rapid and sensitive procedure for estimating low numbers of Clostridium perfringens has been investigated and compared to methods used currently in the food industry. The new liquid medium, RPM (rapid perfringens medium), was compared with sulfite-polymyxin-sulfadiazine agar and tryptose-sulfite-cycloserine agar in recovery studies with naturally contaminated and with inoculated foods. The me...

acute appendicitis is the most common condidition, requiring emergency operation in children. late appendicitis is still a major sours of morbidity and potential mortality. the charts of all pediatric appendectomy patients (150 cases) treated between 1367-1373 (iranian calender) in amir kabir medical center were reviewed. mean hospital stay was 4.7 days. mean ages of patients was 8.5 years. mal...

Curing is the first process of skin treatment mainly using sodium chloride salt to prevent its decay. At soaking step tannery, effluents will be discharged environment, which contains ion, negatively affect our environment. Therefore, it should either treated or reused so that can help reduce amount ion effluent environment and cost pickling. This study focused on recycling curing for sheepskin...