فهرست مطالب s javid

Oilseeds are one of Iran's major imported items in the agricultural sector, and the per capita consumption of edible oil in the country is about twice the global per capita consumption. Therefore, considering the increase in the prevalence of cardiovascular diseases and obesity in the society, and on the other hand, the body's need for fatty acids and the necessity of using oils in cooking all kinds of food and sweets, it is necessary to determine the factors affecting the amount and type of oil used by households. In this regard, the present study was conducted in 2018 on 245 households living in Mashhad city. Sampling of the statistical population of the research was done by a simple random method and data and statistics were collected by completing the questionnaire. Data processing was also done using descriptive statistics methods as well as ordered logit and multinomial logit regression models. The results of the study showed that the variables of importance to health, education, awareness of the presence of palm and the number of family members had an effect on the type of oil consumed. According to the results of the research, the share of liquid oil in the total household oil consumption is 41 percent, and the share of local oil consumption in the household diet is estimated to be around 2.4 percent due to its high price. Despite being useful, natural oils make up only about 24 percent of the total household oil consumption. Therefore, it is suggested that the benefits of using natural and local oils compared to other oils should be explained to the society through appropriate educational and promotion programs as well as by informing consumers more.

In order to precise design, the determination of flow behavior in open channels have always been subjected by the hydraulic researchers. The traditional Manning-Strickler, Keulegan, and Colebrook-White equations provide inaccurate estimations for resistance coefficients in roughened rectangular channels. In this research, flow resistance coefficients both in smooth and rough rectangular channel sections were investigated by using experimental models and three types of river materials. The results show that the revised Strickler formula estimates Manning's n with an average error about 2.56%; and the revised Keulegan equation for smooth and Colebrook-White equation for roughened channels give some good agreements with the experimental measurements by an error of less than 4.91% and a correlation coefficient of 0.983. Some empirical derived equations are also presented which gives the value of Nikuradse sand equivalent roughness, ks, as a function of roughness diameter size. A new explicit formula presented for friction factor, f, using gene expression programming (GEP) for uniformly roughened rectangular channels with an average relative error 5.1% and the corresponding correlation coefficient, 0.981.

In order to precise design, the determination of flow behavior in open channels have always been subjected by the hydraulic researchers. The traditional Manning-Strickler, Keulegan, and Colebrook-White equations provide inaccurate estimations for resistance coefficients in roughened rectangular channels. In this research, flow resistance coefficients both in smooth and rough rectangular channel sections were investigated by using experimental models and three types of river materials. The results show that the revised Strickler formula estimates Manning's n with an average error about 2.56%; and the revised Keulegan equation for smooth and Colebrook-White equation for roughened channels give some good agreements with the experimental measurements by an error of less than 4.91% and a correlation coefficient of 0.983. Some empirical derived equations are also presented which gives the value of Nikuradse sand equivalent roughness, ks, as a function of roughness diameter size. A new explicit formula presented for friction factor, f, using gene expression programming (GEP) for uniformly roughened rectangular channels with an average relative error 5.1% and the corresponding correlation coefficient, 0.981.