فهرست مطالب a shakeri

In this paper, a new structure of the SiC metal-semiconductor field effect transistor (SiC-MESFET) is presented. In the proposed structure of the upper part of the channel under the gate, a semiconductor with very low impurity density is used and at the bottom of the channel, a semiconductor with a high impurity density is used. The most important electrical characteristics of the proposed transistor such as breakdown voltage, drain current, threshold voltage, electric field and gate capacitor are simulated and compared with these characteristics in conventional transistor. According to the simulation results, the proposed structure reduces the maximum electric field in the channel and thus increases the breakdown voltage from 127 V to 136.5 V compared to the conventional structure. The new structure also increases the saturation drain current by 30% compared to the conventional structure. The high density of impurities in the channel bottom causes a negative shift in the threshold voltage in the provided transistor. According to the obtained results and increasing the drain current and the breakdown voltage, the proposed transistor can be used in high power applications.

Literary Theory and Criticism: An Interdisciplinary Textbook is written by Hossein Payendeh as a university textbook for master's degree course in Persian language and literature. It was first published in two volumes in 2018 by SAMT publications. Given the global importance of interdisciplinary studies in literature in recent decades as well as the need of the same in Persian literature, the current article makes an attempt to investigate the extent and manner of the application of interdisciplinary approaches in the aforementioned book. Taking into account historiographical and critical-analytical approaches, we could obtain a history of the theory and literary criticism in the West and then in Iran. This topic has also been presented in the official curriculums of Iranian universities. The form and structure of the book were studied after explaining the prevalence of the literary criticism discourse in Iran. In the section on reviewing the content, while enumerating the most important variables of the book, the relation of topics with the current situation of the theory and literary criticism in the West and Iran was explained and its contents drew the attention in order to confirm interdisciplinary studies in Persian literature. Based on the findings of this article, it can be argued that the publication of Literary Theory and Criticism: An Interdisciplinary Textbookwhile preserving the link with literary theories, indicating a break from those theories and turning attention to interdisciplinary studies in Persian literature. Its publication as an academic textbook can be considered as a turning point in academic literary studies in Iran.

Chahnimeh water reservoirs in Sistan and Baluchestan Province are the most important sources for drinking water and irrigation purposes. Many factors such as precipitation, the geography of the watershed, atmosphere, geology and Human activities affect on the chemical, physical, and biological compositions of Chahnimeh water reservoirs. Therefore, the main goal of the present study was to monitor and assess water quality in four Chahnimeh reservoirs during two sampling periods. 84 water samples were taken based on the standard methods (in September 2017 and April 2018) for measurement of the most important physicochemical parameters including major anions, total coliform, BOD, EC, TDS, pH and nitrate. Water quality index (WQI) was used to evaluate the overall water quality status in the Chahnimeh reservoirs. The results of hydro-geochemical analysis indicated that the water type changed from sodic bicarbonate and sulfur dioxide to radicle chloride during sampling periods. The Gibbs chart showed that weathering of rocks mainly controlled the chemistry of the main water ions. The results of statistical analyses revealed that there was a high correlation between parameters such as chlorophyll, nitrate, sulfate and chlorine with water quality index. Water quality zoning results based on the WQI index indicated a decrease in the water quality of the wells by 3, 2, 1, and 4, respectively. In this study, the use of WQI was helpful for fast data interpretation for drinking water purposes in the area. Based on the WQI classification, majority of the samples are falling under good to poor water category.

The genus Ephedra (Ephedraceae) consists of about 40 species of mostly shrubs and rarely small trees around the world. In the present study, the essential oil (EO) diversity and genetic relationships were investigated in six Ephedra species from Iran using Random Amplified Polymorphic DNA (RAPD) markers.

Theplants were collected from two different provinces; Azarbayjan (north-west) and Khorasan (north-east) of Iran. The EOs were obtained by hydro-distillation and analyzed by GC and GC/MS. The DNA was extracted from the aerial parts of the plants using a Qiagen Dneasy Plant Mini Kit. Amplification was performed using decamer RAPD primers.

A total of 187 bands were scored and used for the analysis of genetic distances. Genetic distance values ranged from 0.25 to 0.95.The analysis showed the highest genetic diversity (25%) between E. foliata with other species. Ephedra foliata formed a distinct group. Ephedra strobilacea was found to be the most similar to E. sarcocarpa (male).

High genetic and EO diversity was demonstrated in this genus which should be further studied in order to make more efficient use of the species and considering relevant conservation programs.

The elements of fraud in forging documents are supporting unreality, deceiving others, deceit and insistence, all of which are mentioned under the title of "purpose of fraud" in Article 523 on defining fraud. However, this crime is not conditioned by a specific result but its existence, the intention to have the result and its ability to occur are necessary elements. The subject of fraud in forgery is an unreal text and is a deceiving message of such evidence that has appropriate evidences. Hence, the deletion of or adding a word or assigning a piece of evidence is not a fraud in itself, unless it is a positive or denying factor for the reality; in addition, carrying out minor repairs on electronic cards in order to use them is not a fraud unless it is for some special purpose.

Cellulose، microcrystalline cellulose (MCC) and nanofiber cellulose are the ones of materials which are being used recently as biodegradable filler and reinforcing agent for making composites. In this research microcrystalline cellulose were prepared from kenaf and cotton bast by hydrochloric acid hydrolysis. The effects of hydrolysis condition on amount of crystallinity and crystal size of MCC were investigated by infrared spectroscopy (FT-IR)، Xray diffraction (XRD) and scanning electron microscopy (SEM). Results have shown that in both samples increasing the acid ratio increased the crystallinity however; the size of crystals did not change. SEM results have shown that after hydrolysis the size of sample particles was micro.

In this research، For Vanillin preparation from lateral product of pulping factory، first، lignin was extracted from kraft cooking liquors of softwood (pinus eldarica) and the FT–IR spectrum of lignin was investigated and it was compared with standard. The amount of extracted lignin was 27% based on oven dry weight of wood. Then vanillin is prepared by oxidation of lignin under pressure. Finally the vanillin concentration in product solution was analyzed with FT–IR and HPLC. The yield obtained from this work was around 4. 2% (wt vanillin / wt lignin).

Agriculture sector is certainly one of the most important parts of economy and due to added-value factor can be regarded as the premier productive sector in the country. Despite having a strategic significance in materialization of economic goals of the country, and accounting for a noticeable share of the GDP, agriculture sector grabs a minor proportion of the country’s investments. Taking some seminal theories of investment into account, one may argue that on the one hand investment in one sector is influenced by the incomes, and on the other hand, it is affected by investment costs. The current paper aims to investigate to which economic macro-variables (incomes and costs) is investment in Iran’s agricultural sector susceptible; whether the demand for investment in agricultural sector is mainly influenced by the incomes of the sector or the varying investment costs are affecting the tendency of the investors? Assessing the non-linear demand model of investment suggests that investment demand in agricultural sector is mainly affected by the price variable. The price variable utilized in this study is the indicator of the price of agricultural products. In other words, adopting appropriate price policies in this sector will urge further investment. Also, the analysis of the above model indicates that investment cost is the second factor influencing demand for investment after price variable. Furthermore, the susceptibility of investment to the sector incomes outweighs its susceptibility to costs of investment.

Inflammation and oxidative stress are common in patients with chronic renal disease, including hemodialysis patients. The present study was designed to investigate the effects of L-carnitine supplements on inflammatory cytokines, CRP and oxidative stress in hemodialysis patients.

The study was a randomized clinical trial. Thirty-six hemodialysis patients, (23 males and 13 females), were randomly assigned to either carnitine group or the control group. The patients in the carnitine group received 1000 mg/d oral L-carnitine for 12 weeks while the control group did not receive any L-carnitine supplement during the study. At the baseline and the end of 12th week of the study, 5 ml. blood was collected after a 12 to 14-hour fast from each patient before dialysis and then serum free carnitine, CRP, IL-1β, IL-6, TNF-α and ox-LDL were measured.

Mean serum free carnitine concentration increased significantly, by 86%, in the carnitine group at the end of 12th week as compared to the baseline (P<0.001), while serum CRP and IL-6 decreased significantly, by 29% (P<0.05) and 61% (P<0.001), respectively. No significant changes were observed in the serum concentrations of free carnitine, CRP and IL-6 in the control group during the study. There were no significant differences between mean changes of serum IL-1β, TNF-α and ox-LDL concentrations in the two groups.

This study indicated that L-carnitine supplement could improve carnitine deficiency and decrease inflammatory markers of CRP and IL-6 in hemodialysis patients.