22 research outputs found

    Observation of EGRET Gamma-Ray Sources by an Extensive Air Shower Experiment

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    Ultra-high-energy (E>>100 Tev) Extensive Air Showers (EASs) have been monitored for a period of five years (1997 - 2003), using a small array of scintillator detectors in Tehran, Iran. The data have been analyzed to take in to account of the dependence of source counts with respect to the zenith angle. During a calendar year different sources come in the field of view of the detector at varying zenith angles. Because of varying thickness of the overlaying atmosphere, the shower count rate is extremely dependent on zenith angle which have been carefully analyzed over time. High energy gamma-ray sources from EGRET third catalogue where observed and the data were analyzed using an excess method. A number of upper limits for a number of EGRET sources were obtained, including 6 AGNs or probably AGNs and 4 unidentified sources.Comment: 14 pages, 8 figures, Astronomy and Astrophysics, accepte

    A Study on anisotropy of cosmic ray distribution with a small array of water-cherenkov detectors

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    The study of the anisotropy of the arrival directions is an essential tool to investigate the origin and propagation of cosmic rays primaries. A simple way of recording many cosmic rays is to record coincidences between a number of detectors. We have monitored multi-TeV cosmic rays by a small array of water cherenkov detectors in Tehran(35 43 N, 51 20 E, 1200m a.s.l). More than 1.1*10^6 extensive air shower events were recorded. In addition to the Compton- Getting effect due to the motion of the earth in the Galaxy, an anisotropy has been observed which is due to a unidirectional anisotropy of cosmic ray flow along the Galactic arms.Comment: 16 pages 9 figs and one tabl

    An introduction of photobioreactor technology in mass culture of algea in order to improve the shrimp culture in Iran

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    Algae production in controlled condition is one one the most important subject that ought to studying . This kind of algae production can use for biosynthesis great syuffs like as vtamines and unsaturated fatty acids. For achieving this goal < this project was designed and done. At this project some procedures like steril cultivation < light controlling, remove and dissolving gases as oxygen and carbon dioxide, mixturing tank, intelligent sensor, biofilter purifying, dechloration vessel and dosing pumps are new phenomenas are used. Finally, chlorella sp from Gilan institute were culativated more than 16000000 cells per one millimeter

    Supply and protected different population of Litopenaeus vannamei subadult zero foster (F0) from difference provinces Iran

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    Nowadays, Litopenaeus vannamei are the most important species of farmed penaeidae shrimp in the world that is rapidly replacing native species in areas aquaculture. Due to demand increase for this species culture, shrimp displacement to different areas may be associated with some potential pathogens transferred to new areas farmed. Therefore, in this study were prepared bi-osecurity conditions for specific disease-free production of L. vannamei. Thereafter, three populations (Molokaei, High health and mix of Molokaei and High health) of the shrimp various reserves were detected base on origin and genetic indexes such as: observed heterozygosity, expected heterozygosity, allele frequency, coefficient inbreeding, genetic differentiation, genetic distance and genetic identity. On the other hand, epidemiological studies indicate non pathogens (viral, bacterial, fungal and parasitic) recognition of different populations selected in the quarantine salon. The bioassay results showed that the average weight and length of the populations of High health and Mix significantly greater than was a population of Molokaei. The shrimp populations were stocked in fiberglass tank (five ton) and were kept separated in the quarantine salon. During maintenance shrimp of populations in the quarantine salon were evaluated living and non-living pathogens with PCR, microbiology and biochemical methods. There is not any pathogens detection from shrimp populations stocking in the quarantine salon, so the shrimps were carried over to pond for broodstock culture of specific pathogenic free

    Comparison of low-calorie diet with and without sibutramine on body weight and liver function of patients with non-alcoholic fatty liver disease

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    Introduction & Objective: Non-alcoholic fatty liver (NAFLD) is defined as a spectrum of clinical scenarios which is pathological deposition of fat droplets in the liver of patients who have no history of alcohol use. This study compared the effect of low calorie diet with and without sibutramine on body weight and liver function in patients with NAFLD. Materials & Methods: This clinical trial study was conducted in 2010 at Tabriz University of Medical Sciences, on 40 obese patients with non-alcoholic fatty liver. Patients were randomly divided into two equal groups of intervention and control groups. Group one received 15 mg daily sibutramine capsules half an hour before lunch and a weight loss diet based on ideal body weight. The other group only had diet control for weight reduction. Before and after 3 months of intervention, weight changes, fasting glucose, glycosylated hemoglobin HbA1c, levels of liver enzymes and ultrasound evaluation was repeated. Data were analyzed using the SPSS software and the paired T test, Mann-Whitney and McNemar test. Results: The mean age of the subjects was 38.90 ± 7.00 in the sibutramine group and 36.55 ±7.87 for the control group. After three months, the average weight loss in sibutramine group was significantly more than the control group (sibutramine group13 kg and control group 4 kg (p<0.05). Improvement in liver echogenicity in sibutramine patients was 90% and 50% of diet group patients. ALT changes in the sibutramine group and control group was 7.50 ± 15.11 and 6.15 ± 28.23 respectively, which was statistically significant in the sibutramine group. AST changes were 4.38 ± 13.37 and 1.70 ± 18.37 in sibutramine and control group respectively. The changes were not statistically significant. Conclusion: Overall, findings of this study suggest that sibutramine is effective in liver function improvement and treatment of NAFLD patients

    Predictive factors of early moderate/severe ovarian hyperstimulation syndrome in non-polycystic ovarian syndrome patients: a statistical model

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    Purpose: To evaluate demographic, medical history and clinical cycle characteristics of infertile non-polycystic ovary syndrome (NPCOS) women with the purpose of investigating their associations with the prevalence of moderate-to-severe OHSS. Methods: In this retrospective study, among 7073 in vitro fertilization and/or intracytoplasmic sperm injection (IVF/ICSI) cycles, 86 cases of NPCO patients who developed moderate-to-severe OHSS while being treated with IVF/ICSI cycles were analyzed during the period of January 2008 to December 2010 at Royan Institute. To review the OHSS risk factors, 172 NPCOS patients without developing OHSS, treated at the same period of time, were selected randomly by computer as control group. We used multiple logistic regression in a backward manner to build a prediction model. Results: The regression analysis revealed that the variables, including age odds ratio (OR) 0.9, confidence interval (CI) 0.81�0.99, antral follicles count (OR 4.3, CI 2.7�6.9), infertility cause (tubal factor, OR 11.5, CI 1.1�51.3), hypothyroidism (OR 3.8, CI 1.5�9.4) and positive history of ovarian surgery (OR 0.2, CI 0.05�0.9) were the most important predictors of OHSS. The regression model had an area under curve of 0.94, presenting an allowable discriminative performance that was equal with two strong predictive variables, including the number of follicles and serum estradiol level on human chorionic gonadotropin day. Conclusion(s): The predictive regression model based on primary characteristics of NPCOS patients had equal specificity in comparison with two mentioned strong predictive variables. Therefore, it may be beneficial to apply this model before the beginning of ovarian stimulation protocol. © 2015, Springer-Verlag Berlin Heidelberg

    Instrumentation development for an array of water Cherenkov detectors for extensive air shower experiments

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    Abstract A new small array of Cherenkov detectors has been deployed in Tehran, 1200 m above sea level. This array contains four tanks of distilled water with a diameter of 64 cm and a height of 130 cm. The effective area of each tank is about 1382 cm 2 . They are used to detect air showers and to record the arrival time of the secondary particles. We have collected about 640 000 extensive air showers (EAS) in 8298 h of observation time from November 2006 to October 2007. The distribution of air showers in zenith and azimuth angles has been studied and a cos n θ distribution with n = 6.02 ± 0.01 was obtained for the zenith angle distribution. An asymmetry has been observed in the azimuthal distribution of EAS of cosmic rays due to geomagnetic field. The first and second amplitudes of the asymmetry are A I = 0.183 ± 0.001 and A II = 0.038 ± 0.001. Since the recent results are in good agreement with our previous results of scintillation detectors, and tanks of distilled water are cheaper, we prefer to use them instead of scintillators in a future larger array. By simulation, we have improved the size of the detectors to yield the highest efficiency. The best dimensions for each tank with a photomultiplier tube in the center of its lid are 40 cm in diameter and 60 cm in height
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