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In this paper we propose and simulate a new Heterostructure MESFET, Called δ-doped LDD HMESFET. To improve carrier velocity in vicinity of the source in channel of GaAs MESFET, one can replace source with AlxGa 1-x As. By increasing Al content, discontinuity of hetero-interface could be increased. Therefore, the velocity increases in the low field. However, increasing Al mole fraction in excess of some value forces the current to reduce, due to DX centers. To avoid this reduction, we suggest taking the advantage of ?-doped the source-channel hetero-interface. This increase discontinuity of hetero-interface, which is equivalent to increasing Al content. In this paper, we simulate the proposed transistor structure and compare it with the one proposed in [1], ignoring DX centers. In this comparison, we show that the average electron velocity in both transistors is identical.

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  Research subject: Investigation of the effect of temperature on the polymer flooding performance at the pore scale, leads to an understanding of the behavior of the polymer solution in porous media with varying permeability.
Research approach: In this study, the effect of temperature on flooding of polyacrylamide polymer on enhanced oil recovery in two homogeneous micromodels at 25 and 70 °C was investigated. The polymer solution and DW were injected at the injection rate of 1 μl/min up to 1 PV into the micromodel and the amount of produced oil and the movement of the injected fluid in the porous medium were analyzed. In addition, polymer rheology and injected fluid viscosity were measured for better analysis of results. Then the results were compared with flooding of distilled water as the control test.
Main results: Examining the flood results, it was found that on the one hand, the temperature factor helped to increase oil recovery by reducing the viscosity of the oil. On the other hand, it has reduced the role of injected fluid viscosity in oil extraction by reducing the viscosity of the polymer. The results showed that the phenomenon of fingering decreases in the case of polymer injection, and the rate of improvement of oil recovery during polymer and water flooding in both micromodels increases with increasing temperature. Also, the rate of improvement of oil recovery during polymer flooding in the A micromodel increased from about 43% at ambient temperature to more than 51% and in the B micromodel from about 51% to more than 60% at 70 °C. In fact, it can be said that the flow pattern and stability of the polymer solution front and consequently the ultimate oil recovery are significantly affected by the morphology of the pores, the shape and the throats pores.
    

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Backgrounds: This study was conducted with the aim of isolation and molecular identification of Streptomyces spp. producing antibacterial compounds from Iranian soil.
Materials & Methods: In this study, 50 soil samples were collected from different areas of Sanandaj city. Soil samples were cultured on starch casein media. Streptomyces species were characterized using morphological and biochemical assays. Molecular identification was performed by 16S rRNA sequencing. Antimicrobial activity was evaluated using perpendicular streak and agar well diffusion methods.
Findings: To identify active Streptomyces strains in terms of producing antibacterial agents, screening was performed in two stages. Among 20 Streptomyces strains isolated from soil samples, six isolates were selected in the primary screening stage based on their ability to limit the growth of pathogens. Of the two solvents used in the secondary screening stage, ethyl acetate was the most suitable solvent for extracting effective metabolites of Streptomyces. Among the six isolates selected based on their antimicrobial activity, two isolates with the highest antibacterial activity were selected for the sequencing process. By analyzing the dendrogram and the data obtained from the NCBI database, it was found that one isolate (Yellow 4A) was 98% similar to S. fradiae, and the other isolate (Green 4A)  was 98% similar to S. coelicolor.
Conclusion: The use of proper strategies to identify potential new Streptomyces species with antibacterial properties may bring a bright future in the treatment of resistant pathogens. However, more studies are required to detect active metabolites of the mentioned isolates.

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 In this experiment, a total of 128 Hy-line W₃₆ hens at 63 weeks of age were used. The hens were put at random into 4 treatment groups (4 replicates and 32 hens per treatment) and were fed four different diets: three diets with different levels of Spirulina (1.5, 2.0 and 2.5%) and one control group based on wheat and soybean meal. All birds were housed in commercial cages, had ad libitum access to water, and were fed 100 g bird^-1 per day. Egg production, feed intake, feed conversion ratio, egg weight, yolk index, Haugh unit, shell thickness, shell weight, specific gravity, egg yolk cholesterol, and yolk color were compared with the control group. Egg yolk color was measured by the BASF Ovo-color fan. Our results indicated that these traits did not show any significant changes with the Spirulina addition (P> 0.05), while a significant increase in egg yolk color was observed in the treatments that received the Spirulina (P< 0.0001). Yolk color scores of the control group and different levels of Spirulina (1.5, 2.0 and 2.5%) were 1.5, 10.5, 11.4 and 11.6 in BASF color fan, respectively. There were not significant differences between the treatments with 2.0 and 2.5% of Spirulina. In conclusion, this study can suggest use of 2.0~2.5% of Spirulina in diet to produce an aesthetically pleasing yolk color.

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 The nutritive value of grass pea (Lathyrus sativus L.) hay was evaluated based on its chemical composition, Gas production, fractioning of protein in CNCPS and AFRC systems, Metabolizable Energy (ME), rumen degradability through in situ technique and in vitro digestibility through Tilley and Terry method. The Crude Protein (CP), Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) values of grass pea hay amounted to 232.4, 397 and 300.6 (g kg^-1 DM) respectively. Condensed Tannins (CTs) and β-N-Oxalyl –L-α, β-diAmino Propionic acid (ODAP) amounted 0.2 and 11.8 (g kg^-1 DM) respectively. Grass pea estimated ME ranged from 6.86 (MJ kg^-1 DM) to 12.03 (MJ kg^-1 DM) by different methods. Metabolizable Protein (MP) content was found 534.7 g kg^-1 of CP. A high level of CP and MP content followed by a high content of ME along with a high palatability, cause grass pea to be introduced as an alternative to sheep forage in drought conditions.