امیر زاهدی

One of the duties of jurists is to respond to new issues. One of the newest human issues in the field of nutrition, which is caused by the increasing need of humans for new food and due to the progress of science and technology, is the production of meat through cell culture in the laboratory. From a jurisprudential point of view, this issue has different dimensions that require comprehensive analysis. Is the principle of this work legally permissible or not? What is the status of produced meat in terms of taharat and najasat?And is it permissible to eat these meats on the assumption of taharat or not? These are the questions that the present article tries to answer by using the analytical descriptive method, and tried to examine the many aspects of the problem from different angles and open a way towards permission, taharat and heli'yat.

Presumption of Continuity (Istishāb) is one of the most applicable evidences in deducing legal rules, one of which is future time presumption of continuity according to definite and uncertain time. Future time presumption of continuity means that given all the three sureness time, doubt, and definite happen at present before the obliged but the uncertain time is presumed in the future, it is reinstated from its continuation to the future. Likewise present common type of presumption of continuity, such a kind of presumption of continuity has got paramount significance and application to jurisprudence and deduces rules. However, most of Osūli scholars have failed to discuss it and trivial discussion have been made regarding to this type of presumption of continuity in Osūli books, albeit there are some evidences to the effect that future time presumption of continuity could be proved. The traditions on the issue of presumption of continuity and conformity of presumption of continuity with future time presumption of continuity prove the validity of future time presumption of continuity and would resolve the proposed problems in this regard. Similarly, a review of its applications to jurisprudence such as bedār permissibility, blood money non- reparation, early transaction necessity, trustee's justice, fetwā alteration, and etc. all show the significance of this type of presumption of continuity.

Each channel of the phased array antenna intrinsically has the phase errors. This is because of the position and orientation error of antenna elements due to assembling tolerance or mechanical distortion, and the electric length error of each RF channel. These errors can decrease the antenna performance, for instance the gain reduction, sidelobe level enhancement, and inaccurate beam direction. In order to improve the performance of the antenna in the presence of phase errors, a phase correction method using Genetic Algorithm (GA) is proposed. By using the proposed method, the antenna overall radiation pattern is recovered close to ideal radiation pattern without error. By applying the simulation data to a large array of 32 40 elements at the frequency of S-band the effectiveness of the proposed method is verified.

Hospital wastes are very dangerous for the environment. The objective of this study was the investigation of knowledge, attitude and performance regarding medical waste management among the personnel of hospitals affiliated with Tehran University of Medical Sciences, Iran.
This descriptive cross-sectional study was conducted in hospitals affiliated with Tehran University of Medical Sciences in 2014. The data collection tool was a 3-part researcher-made questionnaire about hospital waste management. Kruskal-Wallis, Mann-Whitney, Spearman rho’s coefficient correlation, and Cramér's V were used to analyze the collected data.
Findings: The findings showed that the staff’s knowledge and attitude was at a low level, but their performance was at a moderate level. Based on Kruskal-Wallis test results, there was no statistically significant relationship between personnel’s knowledge and participation in health courses.
Considering the low knowledge and attitude of staff in this study regarding hospital waste disposal management, holding training courses for staff to improve their knowledge and attitudes is recommended.

Background Many industries can pollute water quality due to their wastewater discharging into water resources. Textile industries are one of the main sources of water pollution. Due to their high toxicity, wastewaters containing dyes cause many environmental problems. Acidic dyes are one of the main classes of dyes. In this study, nano-alumina and micro-alumina powder have been used for the adsorption of acid red 14 dye.
Materials & Methods This study was carried out in the batch system in laboratory scale. Different parameters such as initial dye concentration, pH, and adsorbent dose were examined. Spectrophotometry (UV/VIS Lambda 25 Perkin Elmer, Shelton) was used to quantify the remaining dyes concentration. Adsorption isotherm and kinetic behaviors of adsorbent for acidic dye removal were studied and fitted to different models.
Results The result showed that with increasing the contact time, acid red 14 removal efficiency by micro-alumina and nano-alumina powder and amount of adsorption per mass unit (qe) increased to 18 and 40 mg/L, respectively, and when adsorbent dose increased from 0.2 to 1.2 g/L, qe decreased from 23 to 12 and 47 to 39, respectively. With increasing the pH value in examined range, the removal efficiency decreased from 30 to 6 and 60 to 15 for micro-alumina and nano-alumina powder, respectively. The results of the study of adsorption of acid red 14 by micro-alumina and nano-alumina powder revealed that its kinetics obeyed pseudo-second order (R2>0.99 and 0.98, respectively). The results of present study on adsorption of acid red 14 on micro-alumina and nano-alumina powder revealed that isotherm obeyed Langmuir adsorption (R2 >0.99 and 0.98, respectively).
Conclusion The present study showed that the nano-alumina rather than mciro-alumina can be a promising adsorbent for the removal of acidic dyes such as acid red 14.

This paper examines the effects of operating point and device size on the high frequency noise parameters in CMOS technology, to eliminate high power dissipation challenge in simultaneous noise and input matching (SNIM) technique. Modified technique is applied to improve power dissipation problem, noise performance, gain and input/output matching of the LNA at center frequency of 5.2 GHz. The LNA is implemented in TSMC 0.18-µm CMOS process. Post-layout simulation results demonstrate LNA has reached to power consumption of 2.1 mW under 1.4 V supply while having, 2.71 dB noise figure, 1GHz Band-width, 16.38 dB power gain, -40.42 dB reverse isolation factor, -21.5 dB and -23.59 dB input/output return loss respectively.

Background and Petrochemical industries and refineries are regarded as important emission sources of inorganic and organic pollutants. The aim of this study was to survey TVOCs and BTEX in the air of South Pars Special Economic Energy Zone in 2014.
In a cross-sectional study sampling and analysis was done by NIOSH 1501 method. The study was carried out in 336 activated carbon tubes and personal sampling pump in 6 sampling stations during one year. The compounds were extracted by solvent carbon disulfide and analyzed using Gas Chromatography- Flame Ionization Detector (GC-FID). Data analysis was performed in SPSS Ver.18 applying Kruskal-Wallis, Fligner test and ANOVA.
The mean concentrations of TVOCs and TBTEX were 229.34 and 31.23 µg/m3 in cold season and 212.19 and 29.89 µg/m3 in warm season, respectively. The mean concentrations of Benzene in all stations were 11.72 µg/m3 which were higher than the threshold levels recommended by Iranian Clean Air Act and US Environmental Protection Agency (USEPA). The ANOVA results showed a significant difference between the concentration of pollutants and hour, month and sampling stations (P0.05).
The concentrations of measured pollutants in cold season were higher than those in warm season. High concentrations of Benzene in cold and warm seasons were used to identify areas of high exposure risk.

Humic substances belong to a group of micro molecular of organic substance with different molecular weight produced by reaction of biological and geochemical process. They are known as one of the main prefabrications of disinfection byproducts. This study aimed at investigating the efficacy of (ZnO) nanoparticle under UV/ZnO radiation in removing humic acid. This study was conducted under laboratory condition. An interval reactor was used to eliminate humic acid by (ZnO) nanoparticle and UV lamp (125 W Philips HPLN). The humic acid was considered in 2, 5, 7 and 10 mg/lit concentrations. To measure the residue of humic acid after radiation of photo Photocatalytic, Spectrophotometer model (UV/VIS Lambda 25 Perkin Elmer, Shelton) was used. The results showed a decrease in efficiency rate when humic acid concentration and pH increased. By increasing the time of photocatalytic activity the removal effect increased. Also, we observed that single-step process and two-step process with higher removal efficiency at Zno concentration of 0.2 mg/l and 0.5 mg/l, respectively. The two-step process was found more capable of removing humic acid with 98.95% efficiency at the concentration of 0.5 mg/l ZnO, detention time of 30min, and at pH 4. This study suggests the use of UV/ZnO process as a suitable method in removing humic acid from aqueous solutions.

Each Channel of the phased array antenna innately has the amplitude and phase errors. The effect of mechanical errors on the performance of the active phased array antennas is of great importance. In this paper two kinds of mechanical errors, namely, antenna structural distortions and random errors in element positions is studied and the relationship between the electromagnetic performance and the mechanical errors of the antenna is proposed. The mechanical errors can create phase errors and reduce the antenna performance, for instance the gain reduction, sidelobe level increase, and inaccurate beam direction. In order to enhance the performance of the antenna in the presence of mechanical errors, a phase compensation method for error correction using Particle Swarm Optimization (PSO) is proposed. The simulation results show that the proposed method can greatly correct the phase errors and after correction the overall radiation pattern is recovered close to ideal radiation pattern without error.

Safety is one of necessary infrastructures for constant development. Road safety is very important and have a considerable role in reducing of wastage and injury and fatal accidents effective factors in accidents are road problems technical fault and human factor. According to statistics and expert ideas, 20 percents of accidents happen because of road problem, 10 percents happen because of technical fault and 10 percents occur because of human factor. In recent years, with technology deployment in vehicle design and increasing of standard roads, human factor role being main important factor in accidents occurring unauthorized speed is a main important factor in appearing human errors. This article have been considered to execution resolutions in other countries and speed management for road safety increasing. Speed controlling have a basic role in safty improvement. Investigation show that reducing the maximum speed limit have diminished accident severity and risk of accidents.