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Magnetohydrodynamic Activity During Limiter Biasing on the CT-6B Tokamak

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Chinese Physics Letters 2001年第3期18卷 393-395页

作者： KHORSHID Pejman WANG Long YANG Xuan-Zong FENG Chun-Hua ZHANG Peng-Yun QI Xia-Zhi ROUHANI shahriar RAHIMITABAR M.Reza AGHAMIR M.Farzin GHORANNEVISS Mahmud HANTEZADEH M.Reza Institute of Physics Chinese Academy of SciencesBeijing 100080 Plasma Physics Research Centre Azad UniversityTehranIran Institute for Studies in Theoretical Physics and Mathematics TehranIran

Magnetohydrodynamic phenomena in the CT-6B Tokamak based on Mirnov oscillations have been investigated by applying the limiter biasing potentials and changing the vacuum chamber gas pressure and plasma *** results show that setting up a radial electric field at the plasma edge could drive electromagnetic instabilities in the tokamak *** oscillation frequency upon application of a positive bias decreases about 10-15%and then after a delay time,τ_(d)=2.5-3 ms increases about 20-25%with respect to their value without *** the negative bias regime the oscillation frequency increases about 10%in 1 ms after the application of the bias *** poloidal rotation velocity changes during two steps are related to its link with the radial electric field and the time scale of the density *** frequency of oscillations increases with the increasing chamber gas pressure and decreases with the increasing the outward plasma displacement.

关键词： Tokamak oscillation tokamak

Extreme climate projections over the transboundary Koshi River Basin using a high resolution regional climate model

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Advances in Climate Change Research 2017年第3期8卷 199-211页

作者： Rupak RAJBHANDARI Arun Bhakta SHRESTHA Santosh NEPAL shahriar WAHID REN Guo-Yu Department of Meteorology Tri-Chandra Campus Tribhuvan University Kathmandu Nepal International Centre for Integrated Mountain Development Kathmandu Nepal National Climate Center China Meteorological Administration Beijing 100081 China

The high-resolution climate model Providing REgional Climates for Impacts Studies (PRECIS) was used to project the changes in futureextreme precipitation and temperature over the Koshi River Basin for use in impact assessments. Three outputs of the Quantifying Uncertaintiesin Model Prediction (QUMP) simulations using the Hadley Centre Couple Model (HadCM3) based on the IPCC SRES A1B emission scenario were used to project the future climate. The projections were analysed for three time slices, 2011e2040 (near future), 2041e2070 (mid-century), and 2071e2098 (distant future). The results show an increase in the future frequency and intensity of climate extremes events such as dry days, consecutive dry days, and very wet days (95th percentile), with greater increases over the southern plains than in the mountainous area to the north. A significant decrease in moderate rainfall days (75th percentile) is projected over the middle (high) mountain and trans-Himalaya areas. Increases are projected in both the extreme maximum and extreme minimum temperature, with a slightly higher rate in minimum temperature. The number of warm days is projected to increase throughout the basin, with more rapid rates in the trans-Himalayan and middle mountain areas than in the plains. Warm nights are also projected to increase, especially in the southern plains. A decrease is projected in cold days and cold nights indicating overall warming throughout the basin.

关键词： Climate change Climate projection Koshi basin PRECIS Extreme climate

Projection of Future Climate over the Koshi River Basin Based on CMIP5 GCMs

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Atmospheric and Climate Sciences 2016年第2期6卷 190-204页

作者： Rupak Rajbhandari Arun Bhakta Shrestha Santosh Nepal shahriar Wahid Department of Meteorology Tri-Chandra Campus Tribhuvan University Kathmandu Nepal International Centre for Integrated Mountain Development Kathmandu Nepal

This paper analyses the climate projections over the Koshi river basin obtained by applying the delta method to eight CMIP5 GCMs for the RCP4.5 and RCP8.5 scenarios. The GCMs were selected to cover the full envelope of possible future ranges from dry and cold to wet and warm projections. The selected coarse resolution GCM outputs were statistically downscaled to the resolution of the historical climate datasets. The scenarios were developed based on the anomaly between the present reference period (1961-1990) and the future period (2021-2050) to generate transient climate change scenarios for the eight GCMs. The analyses were carried out for the whole basin and three physiographic zones: the trans-Himalaya, high-Himalaya and middle mountains, and southern plains. Future projections show a 14% increase in rainfall during the summer monsoon season by 2050. The increase in rainfall is higher over the mountains than the plains. The meagre amount of rainfall in the winter season is projected to further decrease over both the mountain and southern plains areas of the basin for both RCPs. The basin is likely to experience warming throughout the year, although the increase in winter is likely to be higher. The highest increase in temperature is projected to be over the high Himalayan and middle mountain area, with lower increases over the trans-Himalayan and southern plains areas.

关键词： Climate Projection Climate Change Himalaya Koshi Future Scenario

Projection of Future Precipitation and Temperature Change over the Transboundary Koshi River Basin Using Regional Climate Model PRECIS

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Atmospheric and Climate Sciences 2018年第2期8卷 163-191页

The Koshi river basin sustains the livelihoods of millions of people in the upstream and downstream areas of the basin. People rely on monsoon rainfall for agricultural production, hydropower generation and other livelihood activities. Climate change is expected to have serious implication on its environment. To reduce the adverse impacts of disasters and to better understand the implication of climate change for the sustainable development, initiative in this regard is necessary. Analysis of past meteorological trends and future climate projections can give us a sense of what to expect and how to prepare ourselves and manage available resources. In this paper, we have used a high-resolution climate model, viz., Providing REgional Climates for Impacts Studies (PRECIS), to project future climate scenario over the Koshi river basin for impact assessment. Three outputs of the Quantifying Uncertainties in Model Prediction (QUMP) simulations have been used to project the future climate. These simulations were selected from the 17-member Perturbed Physics Ensemble (PPE) using Hadley Centre Couple Model (HadCM3) based on the IPCC SRES A1B emission scenario. The future projections are analysed for three time slices 2011-2040 (near future), 2041-2070 (middle of the century) and 2071-2098 (distant future). Despite quantitative wet and cold bias, the model was able to resolve the seasonal pattern reasonably well. The model projects a decrease in rainfall in the near future and a progressive increase towards the end of the century. The projected change in rainfall is non-uniform, with increase over the southern plains and the middle mountains and decrease over the trans-Himalayan region. Simulation suggests that rainy days will be less frequent but more intense over the southern plains towards the end of the century. Further, the model projections indicate significant warming towards the end of the century. The rate of warming is slightly higher over the trans-Himalayan region

关键词： Future Climate Climate Projection PRECIS Koshi Himalaya

A Study on the Effects of Solar Tracking Systems on the Performance of Photovoltaic Power Plants

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Journal of Power and Energy Engineering 2014年第4期2卷 718-728页

作者： shahriar Bazyari Reza Keypour Shahrokh Farhangi Amir Ghaedi Khashayar Bazyari Semnan University Semnan Iran University of Tehran Tehran Iran Darun Branch Islamic Azad University Shiraz Iran Sharif University of Technology Tehran Iran

The use of renewable energy resources to produce the electricity is a rising trend in various countries worldwide. This is especially because these energies do not produce the greenhouse gases;therefore, don’t become a destructive factor on the ozone layer and the environment. Besides, the fossil energies are always exposed to price changes and will eventually end, while the renewable energies don’t pose such problems and are freely acquired from the nature. Some of the most important of these reproducible energy resources are the energies of the wind and the solar energy. The generation capability of a photovoltaic power plant is largely dependent on the intensity of the sun radiation. On the other hand, the changing of position causes the sun to have a variable shining intensity in different seasons and different times of the year;therefore, some of the solar power plants possess solar tacking systems. This paper studies the different types of photovoltaic systems including fixed panel, photovoltaic farms equipped to the single axis and double axis tracking systems and their effects on the performance of the solar power plants. In order to determine the position of the sun in the sky, the zenith and azimuth angles of it are used to extract the relations between the different parameters of the sun radiation. The resulted parameters are used in the modeling of the single axis and double axis systems. In the paper it is utilized from the sun parameters in Qeshm Island of Iran in the summer of 2011.

关键词： Azimuth and Zenith Angles Photovoltaic Farm Single and Double Axis Sun Tracker Systems

Implementation of Downloadable File Protection Using MAC Address

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Implementation of Downloadable File Protection Using MAC Add...

Flavonoids from the Leaves of <i>Bridelia stipularis</i>with <i>in Vitro</i>Antioxidant and Cytotoxicity Activity

2011 IEEE International Conference on Information Theory and Information Security(ICITIS 2011)

作者： Safiollah Heidari shahriar mohammadi Sadeq Heidari Information Technology Department of K. N. Toosi University of Technology

With the increasing usage of Internet and electronic commerce and share files systems, the need to provide solutions for safer environment and protecting electronic assets is felt more than ever. On the other hand, laws like copyright which protect moral rights of people against stealing their works such as books, paints, music, etc. also face with challenging issues in electronic environments. So, we see statistics on the rise about plagiarism and art theft in virtual spaces. Yet, so many different methods have been represented for protecting files against misuses, include watermarking, cryptography, steganography, etc. In this paper, a new method for protecting and accessing files for buyers in electronic sales is represented. It entails change in files structure using MAC （Media Access Control） address of a computer system, because MAC address is one of the unique properties of a system. Also, some changes in client/server system designing is needed. This method can prevent unauthorized access to the files and it can be use for stabilizing copyright law. This paper, also provides an example of implementing proposed system that will help to explain and understand this method.

关键词： File Protection Client/Server File Download MAC Address

来源： cnki会议评论

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Pharmacology & Pharmacy 2020年第7期11卷 137-146页

作者： Sangita Debnath Puja Kazi Ruhullah shahriar Choudhury Mahmood Hasan Monira Ahsan Department of Pharmaceutical Chemistry University of Dhaka Dhaka Bangladesh Department of Pharmacy State University of Bangladesh Dhaka Bangladesh

Methanolic extract of the leaves of Bridelia stipularis was studied. From this study, we isolated three known flavonoids. They were identified as 7-O-methyl luteolin, apigenin and 5, 7, 2’, 5’ tetrahydroxyflavone by NMR spectroscopic studies. All of them are first time documented for this plant. Different solvent fractions were subjected to in vitro antioxidant and cytotoxicity studies. Both apigenin and ethyl acetate soluble fraction of Bridelia stipularis showed strong antioxidant activity having IC50 value of 8.005, 8.77 μg/mL respectively. Chloroform soluble fraction of Bridelia stipularis exerted the highest toxicity to brine shrimp and petroleum ether soluble fraction showed moderate toxicity having LC50 value of 1.05, 1.71 μg/mL respectively.

关键词： Bridelia stipularis Flavonoid Antioxidant Cytotoxicity

Alpha-fetoprotein specific CD4 and CD8 T cell responses in patients with hepatocellular carcinoma

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World Journal of Hepatology 2010年第7期2卷 256-260页

作者： shahriar Behboudi Stephen P Pereira UCL Institute of Hepatology University College LondonRoyal Free Hospitals

The presence of CD8 T cell responses to tumor associated antigens have been reported in patients with different malignancies. However, there is very little inf ormation on a comparable CD8 and CD4 T cell response to a tumor antigen in liver cancer patients. Here, we re-examine the kinetic and the pattern of T helper 1 and cytotoxic T lymphocyte responses to alpha-fetoprotein (AFP),a tumor rejection antigen in hepatocellular carcinoma (HCC). Then, we discuss the possibility of using AFP-based immunotherapy in combination with necrotizing treatments in HCC patients.

关键词： Hepatocellular carcinoma Alpha-fetoprotein Cell-mediated immunity Immunotherapy

Screening for asymptomatic chlamydia and gonorrhea in adolescent males in an urban pediatric emergency department

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World Journal of Clinical Pediatrics 2017年第3期6卷 154-160页

作者： Megan E Maraynes Jennifer H Chao Konstantinos Agoritsas Richard Sinert shahriar Zehtabchi Ochsner Medical Center University of Queensland SUNY Downstate Medical Center and the Kings County Hospital Center

AIM To determine the prevalence of Chlamydia trachomatis(CT) and Neisseria gonorrhea(GC) in young men seeking care in the emergency department(ED) for non-sexually transmitted infection(STI) related *** This was a prospective, cross-sectional study in an urban ED. The main outcome was the rate of positive CT and GC on urine nucleic acid amplification testing in males aged 16-21 presenting with non-STI related complaints. RESULTS Two hundred and eighty-four patients were enrolled, 271 were included in the final data analysis [age range 16-21, median: 18(quartiles 16-18, 19-21)]. Overall, 17(6.3%, 95%CI: 4%-10%) tested positive for CT and 0%(95%CI: 0%-2%) were found to have GC. The proportion of sexually active subjects was 71%(95%CI: 65%-76%) and 2%(95%CI: 0.6%-4%) reported sex with men. Previous STI testing was reported in 46%(95%CI: 43%-54%) and 13%(95%CI: 8%-20%) of those patients previously tested had a history of STI. Of the patients who tested positive for CT in the ED, 88%(95%CI: 64%-98%) were successfully followed up. CONCLUSION The prevalence of CT infection found by screening was 6.3%. Screening and follow-up from the ED was successful. The findings justify routine STI screening in male adolescents presenting to the ED with non-STI related complaints.

关键词： Chlamydia Gonorrhea Adolescent Public health Emergency department Pediatric