singular perturbation problems have been studied by many mathematicians. since the approximate solutions of these problems are as the sum of internal solution (boundary layer area) and external ones, the formation or non-formation of boundary layers should be specified. this paper, investigates this issue for a singular perturbation problem including a first order differential equation with gen...

Owing to environmentally-destructive impact of aromatic hydrocarbons, such as benzene, benzene ethyl, toluene, and xylenes or BTEXs, these materials are classified as hazardous pollutants in the air. This study studies cancer and non-cancer risk in District 12 of Tehran Municipality, through these components for two groups of employees or storekeepers and gas station customers. By measuring pol...

Owing to environmentally-destructive impact of aromatic hydrocarbons, such as benzene, benzene ethyl, toluene, and xylenes or BTEXs, these materials are classified as hazardous pollutants in the air. This study studies cancer and non-cancer risk in District 12 of Tehran Municipality, through these components for two groups of employees or storekeepers and gas station customers. By measuring pol...

an important factor in the growth medium of plants and chemical plants. native substrates can be used to improve plant performance. to evaluate the effect of growth medium on the herb f. benjamina experimental design was completely randomized with eight treatments and four replications were carried out in the research greenhouse of islamic azad university of jiroft. f. benjamina  plants from ve...

nowadays, protection of environment and safe agricultural production are an important aims of the sustainable agriculture. also, in attention to abundance of saline soil and water resources in the country, the present research was designed to evaluate pgpr inoculation effect on some morphological and physiological traits of two green bean plant cultivars under salinity stress conditions. a gree...

the aim of this study was to investigate the effect  of irrigation period on the quality and quantity of yield and some morphological and physiological traits of three multigerm sugar beet genotypes named bp mashhad, bp karaj and 191. the experiment was in a split  plot  based on randomized complete block  design , carried out  at motahari research station of sugar beet seed research institute ...

the quality of environmental impact assessment (eia) findings, as a decision support system, has always been a function of the extent of its boundaries. meanwhile, boundaries of a study area can be delineated physically or non-physically according to the eia working units or methodologies. six case studies have been conducted to consider the study areas of variety of eias namely, visual, cumula...

conclusions our results showed that only 17% of the measured points in the oil drilling rig floor were in safe area; 39% were in caution area and 44% were in danger area. in the camp facilities area, 51% of the points were in safe area, 38% were in caution area and 11% in danger area. the main sources of noise exposure in the rig floor area were power generators. materials and methods this was ...