High energy gas fracturing is a simple approach of applying high pressure gas to stimulate wells by gen- erating several radial cracks without creating any other damages to the wells. In this paper, a numerical algori...High energy gas fracturing is a simple approach of applying high pressure gas to stimulate wells by gen- erating several radial cracks without creating any other damages to the wells. In this paper, a numerical algorithm is proposed to quantitatively simulate propagation of these fractures around a pressurized hole as a quasi-static phenomenon. The gas flow through the cracks is assumed as a one-dimensional transient flow, governed by equations of conservation of mass and momentum. The fractured medium is modeled with the extended finite element method, and the stress intensity factor is calculated by the simple, though sufficiently accurate, displacement ex- trapolation method. To evaluate the proposed algorithm, two field tests are simulated and the unknown parameters are determined through calibration. Sensitivity analyses are performed on the main effective parameters. Considering that the level of uncertainty is very high in these types of engineering problems, the results show a good agreement with the experimental data. They are also consistent with the theory that the final crack length is mainly determined by the gas pressure rather than the initial crack length produced by the stress waves.展开更多
This experiment was conducted to evaluate the effect of onion (Allium cepa L.) as an antibiotic growth promoter substitute on growth performance, immune responses and serum biochemistry in broilers. A total of 192 one...This experiment was conducted to evaluate the effect of onion (Allium cepa L.) as an antibiotic growth promoter substitute on growth performance, immune responses and serum biochemistry in broilers. A total of 192 one-d-old as hatched broiler chicks (Ross 308) were weighed and randomly allocated to four treatment groups, each with 4 replicate pens of 12 chicks. The dietary treatments consisted of the basal diet (control), antibiotic (15 mg Virginiamycin/kg), and control +10 or 30 g fresh onion bulb/kg diet. Body weights of broilers were determined at d 1, 21 and 42, feed intake was determined at the same periods, and feed conversion ratio was calculated accordingly. At 14th and 21st days blood samples were taken for measuring antibody titers against NDV and at 42nd day for biochemical analysis. At d 42, two birds per replicate were slaughtered for determination of lymphoid organ weights. Dietary supplementation of30 g/kg onion increased final body weight of broilers at 42nd d of age compared to the other treatments (P < 0.05). Birds fed30 gonion/kg in the diet had the highest feed intake than other treatments at different growth periods (P < 0.05). Dietary treatments failed to induce any significant effect on antibody titers against NDV, although the weight of lymphoid organs was significantly (P Broilers receiving30 g/kg onion had a significantly higher HDL and lower triglyceride concentrations compared to control groups (P . Feeding30 g/kg onion resulted in a marked reduction in the concentration of the glucose compared to control groups (P . The results suggested that dietary inclusion of30 g/kg onion can be applied as alternatives to in-feed antibiotics for broiler diets.展开更多
Today environmental assessment is considered and used as the basis and foundation of any kind of human activity. This is the science which gives human the consciousness about abilities and disabilities of his surround...Today environmental assessment is considered and used as the basis and foundation of any kind of human activity. This is the science which gives human the consciousness about abilities and disabilities of his surroundings. This study tried to assess and provide the potential survey of lands in Khuzestan province for agricultural activities by taking into account the climatic elements and displaying different elements in different seasons. To achieve this goal, first produced data were analyzed in GIS software and then the data was tested by professors and experts of department of soil science and was weighted using the Buckley geometric mean model. Finally, the obtained weights were applied in the software and the obtained results are as follow: except some east parts of Khuzestan province which have proper climate for agricultural activities, other regions are not in good conditions and it is necessary to use cultivation with low water requirements and high resistance to heat and sunlight in these areas.展开更多
The effect of laser, as a heat source, on a one-dimensional finite living tissue was stud- ied in this paper. The dual phase lagging （DPL） non-Fourier heat conduction model was used for thermal analysis. The thermal...The effect of laser, as a heat source, on a one-dimensional finite living tissue was stud- ied in this paper. The dual phase lagging （DPL） non-Fourier heat conduction model was used for thermal analysis. The thermal conductivity was assumed temperature- dependent, resulting in a nonlinear equation. The obtained equations were solved using the approximate-analytical Adomian decomposition method （ADM）. It was concluded that the nonlinear analysis was important in nomFourier heat conduction problems. Moreover, a good agreement between the present nonlinear model and experimental result was obtained.展开更多
基金support of Iran National Science Foundation is also gratefully appreciated
文摘High energy gas fracturing is a simple approach of applying high pressure gas to stimulate wells by gen- erating several radial cracks without creating any other damages to the wells. In this paper, a numerical algorithm is proposed to quantitatively simulate propagation of these fractures around a pressurized hole as a quasi-static phenomenon. The gas flow through the cracks is assumed as a one-dimensional transient flow, governed by equations of conservation of mass and momentum. The fractured medium is modeled with the extended finite element method, and the stress intensity factor is calculated by the simple, though sufficiently accurate, displacement ex- trapolation method. To evaluate the proposed algorithm, two field tests are simulated and the unknown parameters are determined through calibration. Sensitivity analyses are performed on the main effective parameters. Considering that the level of uncertainty is very high in these types of engineering problems, the results show a good agreement with the experimental data. They are also consistent with the theory that the final crack length is mainly determined by the gas pressure rather than the initial crack length produced by the stress waves.
文摘This experiment was conducted to evaluate the effect of onion (Allium cepa L.) as an antibiotic growth promoter substitute on growth performance, immune responses and serum biochemistry in broilers. A total of 192 one-d-old as hatched broiler chicks (Ross 308) were weighed and randomly allocated to four treatment groups, each with 4 replicate pens of 12 chicks. The dietary treatments consisted of the basal diet (control), antibiotic (15 mg Virginiamycin/kg), and control +10 or 30 g fresh onion bulb/kg diet. Body weights of broilers were determined at d 1, 21 and 42, feed intake was determined at the same periods, and feed conversion ratio was calculated accordingly. At 14th and 21st days blood samples were taken for measuring antibody titers against NDV and at 42nd day for biochemical analysis. At d 42, two birds per replicate were slaughtered for determination of lymphoid organ weights. Dietary supplementation of30 g/kg onion increased final body weight of broilers at 42nd d of age compared to the other treatments (P < 0.05). Birds fed30 gonion/kg in the diet had the highest feed intake than other treatments at different growth periods (P < 0.05). Dietary treatments failed to induce any significant effect on antibody titers against NDV, although the weight of lymphoid organs was significantly (P Broilers receiving30 g/kg onion had a significantly higher HDL and lower triglyceride concentrations compared to control groups (P . Feeding30 g/kg onion resulted in a marked reduction in the concentration of the glucose compared to control groups (P . The results suggested that dietary inclusion of30 g/kg onion can be applied as alternatives to in-feed antibiotics for broiler diets.
文摘Today environmental assessment is considered and used as the basis and foundation of any kind of human activity. This is the science which gives human the consciousness about abilities and disabilities of his surroundings. This study tried to assess and provide the potential survey of lands in Khuzestan province for agricultural activities by taking into account the climatic elements and displaying different elements in different seasons. To achieve this goal, first produced data were analyzed in GIS software and then the data was tested by professors and experts of department of soil science and was weighted using the Buckley geometric mean model. Finally, the obtained weights were applied in the software and the obtained results are as follow: except some east parts of Khuzestan province which have proper climate for agricultural activities, other regions are not in good conditions and it is necessary to use cultivation with low water requirements and high resistance to heat and sunlight in these areas.
文摘The effect of laser, as a heat source, on a one-dimensional finite living tissue was stud- ied in this paper. The dual phase lagging （DPL） non-Fourier heat conduction model was used for thermal analysis. The thermal conductivity was assumed temperature- dependent, resulting in a nonlinear equation. The obtained equations were solved using the approximate-analytical Adomian decomposition method （ADM）. It was concluded that the nonlinear analysis was important in nomFourier heat conduction problems. Moreover, a good agreement between the present nonlinear model and experimental result was obtained.
