检索结果-南通市图书馆

Communications and Network 2013年第3期5卷 260-265页

作者： shamim Al Mamun M. shamim Kaiser Muhammad R Ahmed Md. Shafiqul Islam Md. Imdadul Islam Department of Computer Science of Engineering Jahangirnagar University Savar Bangladesh Department of Physics Jahangirnagar University Savar Bangladesh Institute of Information Technology Jahangirnagar University Savar Bangladesh School of Information Technology & Engineering University of Canberra Australia

The spot-diffusing technique provides better performance compared to conventional diffuse system for indoor optical-wireless communication (OWC) system. In this paper, the performance of an OW spot-diffusing communication system using Neuro-Fuzzy (NF) adaptive multi-beam transmitter configuration has been proposed. The multi-beam transmitter generates multiple spots pointed in different directions, hence, forming a matrix of diffusing spots based on position of the receiver and receiver mobility. Regardless of the position of the transmitter and receiver, NF controller target the spots adaptively at the best locations and allocates optimal power to the spots and beam angle are adapted in order to achieve better signal-to-noise plus interference ratio (SNIR). Maximum ratio combining (MRC) is used in the imaging receiver. The proposed OW spot-diffusing communication system is compared with other spot-beam diffusion methods proposed in literature. Performance evaluation revels that the proposed NF based OW spot-diffusing communication system outperforms other spot-beam diffusion methods.

关键词： Optical-wireless Communication Spot Diffusion Technique Neuro-fuzzy Imaging Receiver Adaptive Power Allocation

Geochemistry of Palaeoproterozoic Rocks of Aravalli Supergroup: Implications for Weathering History and Depositional Sequence

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Geosciences 2017年第10期8卷 1278-1299页

作者： Pavanesh K. Singh M. shamim Khan Department of Geology Aligarh Muslim University Aligarh India

The Paleoproterozoic Aravalli Supregroup of rocks, hosted in Aravalli Craton of NW shield, is deposited in shallow and deep water conditions. The major lithologies are phyllites and quartzites with significant components of greywacks and dolomite. Geochemical indices in particular, CIA (Chemical Index of Alteration) values (avg. phyllites: 51.6 - 81.5, avg. quartzites: 57.4 - 95.5) calculated from the data of clastic rocks of ASG suggest minimum to highly intense weathering in the source region. Other indices including PIA, CIW and ICV along with plot patterns on the A-CN-K diagram also nearly endorse CIA based interpretation. These rocks possess relatively high Th/U ratios compared to that found in fresh igneous rocks or their high grade metamorphic equivalents. This high Th/U ratio is neither a source inheritance nor a result of oxidation state rather a manifestation of Th hosting mineral accumulation through sorting. Viewed in the context of present stratigraphic succession, the weathering history adduced from geochemistry does not seem compatible but matches well with earlier classification scheme wherein the evolution of Aravalli Supergroup was considered episodic.

关键词： Clastic Geochemistry Aravalli Supergroup Rajasthan Palaeoweathering Indian Shield

Opportunistic Relaying Technique over Rayleigh Fading Channel to Improve Multicast Security

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer and Communications 2023年第8期11卷 134-148页

作者： Md. shamim Hossain Md. Zahurul Islam Sarkar Department of Electrical and Electronic Engineering RUET Rajshahi Bangladesh

The performance of Rayleigh fading channels is substantially impacted by the impacts of relays, antennas, and the number of branches. Opportunistic relaying is a potent technique for enhancing the effects of the aforementioned factors while enhancing the performance of fading channels. Due to these issues, a secure wireless multicasting scenario using opportunistic relaying over Rayleigh fading channel in the presence of multiple wiretappers is taken into consideration in this study. So the investigation of a secure wireless multicasting scenario using opportunistic relaying over Rayleigh fading channel in the presence of multiple wiretappers is the focus of this paper. The primary goals of this study are to maximize security in wireless multicasting while minimizing security loss caused by the effects of relays, branches at destinations and wiretappers, as well as multicast users and wiretappers through opportunistic relaying. To comprehend the insight effects of prior parameters, the closed form analytical expressions are constructed for the probability of non-zero secrecy multicast capacity (PNSMC), ergodic secrecy multicast capacity (ESMC), and secure outage probability for multicasting (SOPM). The findings demonstrate that opportunistic relaying is a successful method for reducing the loss of security in multicasting.

关键词： Ergodic Secrecy Multicast Capacity Probability of Non-Zero Secrecy Multicast Capacity Secure Wireless Multicasting Secure Outage Probability for Multicasting

Antifungal Activity of Selected Medicinal Plant Extract on <i>Fusarium oxysporum</i>Schlechtthe Causal Agent of Fusarium Wilt Disease in Tomato

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2014年第18期5卷 2665-2671页

作者： Farzana Ashrafi Neela Ismat Ara Sonia shamim Shamsi Department of Botany Dhaka University Dhaka Bangladesh Department of Botany Rajshahi University Rajshahi Bangladesh

The antifungal activity of ethanol and acetone extract of leaves of nine medicinal plants: Piper betel, Lowsonia inermis, Psidium guajava, Carica papaya, Moringa oleifera, Mimosa pudica, Catharanthus roseus, Adhatoda vasica and Andrographis paniculata against Fusarium oxysporum the causal agent of Fusarium wilt in tomato was assessed. All the extracts inhibited mycellial growth at various levels. Among them the superior inhibition (100%) was found in 15% concentration of ethanol extract of Lowsonia inermis and Psidium guajava against Fusarium. In all plant extract there were no significant differences between 20% and 25% concentration, except Piper betel, Carica papaya, Andrographis paniculata and Lawsonia inermis. Analysis of variance results on mycelial growth in different concentration shows that the item was highly significant.

关键词： Medicinal Plants Acetone Extract Ethanol Extract Inhibitory Effect Disease Management

Carbonatite Occurrence in Ambaji-Sendra Belt of NW Indian Shield: Evidence of Carbonatitic Magmatism in the Subduction Setting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Geosciences 2023年第1期14卷 52-74页

作者： Sadaf Siddiqui Sadaf Fatima Tavheed Khan Mohammad shamim Khan Department of Geology Aligarh Muslim University Aligarh India Oil and Natural Gas Corporation Nazira India Geochemistry Division CSIR-NGRI Hyderabad India

The paper represents a new discovery of a late Mesoproterozoic lenticular and discontinuous, carbonatitic body exposed at Basantgarh, Sendra and near the Abu-road area of the Ambaji-Sendra belt of the South Delhi Fold Belt. It is medium to coarse-grained and light to dark coloured compact rock. The common associates of the carbonatitic rock are felsic rocks, rich in alkalies. Carbonatite contains more than 50% carbonate minerals, the majority of which are calcite, dolomite, ankerite, augite-aegirine augite and plagioclase. It is classified as calcite carbonatite of the sövite variety due to its coarse-grained character, chemically as calico-carbonatite and magnesio-carbonatite and even as silico-carbonatites for having more than 20% SiO2. The ∑REE contents of calico-carbonatite samples are nearly 100 times greater than magnesio-carbonatite. Chondrite normalised REE profiles of calcio-carbonatites are LREE enriched with nearly flat HREEs whereas the magnesio-carbonatite is characterised by flat REE patterns. The mantle-normalized incompatible trace element spidergram of Ambaji-Sendra belt carbonatites shows distinct negative anomalies of Ba, Nb, Ta, P, Sm, Eu, Ti and Y and positive at U and Pb by calcio-carbonatite whereas the magnesio-carbonatite displays negative kinks at K, Zr, Nb, Ta and Ti and positive at Th, Pb and Sr. The variable and/or contrasting enrichment/depletion in various elements in the two types of Ambaji-Sendra belt carbonatite is attributed either to significant differences in the type and modal proportion of different accessory mineral species or selective incorporation of metasomatic fluids during the subduction process. The chemical attributes of Ambaji-Sendra belt carbonatite suggest its emplacement in subduction settings.

关键词： Aravalli Craton Ambaji-Sendra Belt Precambrian Carbonatite Subduction Set-ting

运用光谱参数冠层覆盖度建立作物长势及氮营养状态模型

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

光谱学与光谱分析 2016年第1期36卷 231-236页

作者：陶志强 shamim Ara Bagum 马玮周宝元付金东崔日鲜孙雪芳赵明中国农业科学院作物科学研究所农业部作物生理生态与栽培重点开放实验室北京100081

为了探索运用数码照片中光谱(红、绿、蓝)的像素计算得到的冠层覆盖度(canopy cover,CC)对玉米长势及氮素营养状态进行非破坏性监测的技术。通过获取玉米冠层的数码照片图像,定量化数码照片色彩参数与作物叶面积指数(leaf area index,L... 详细信息

为了探索运用数码照片中光谱(红、绿、蓝)的像素计算得到的冠层覆盖度(canopy cover,CC)对玉米长势及氮素营养状态进行非破坏性监测的技术。通过获取玉米冠层的数码照片图像,定量化数码照片色彩参数与作物叶面积指数(leaf area index,LAI)、冠层干重(shoot dry matter weight,DM)、叶片氮素含量(leaf nitrogen content percentage,N%)之间的关系。试验于2012年和2013年在中国农业科学院试验田进行,运用基于Visual Basic Version 6.0研发的玉米冠层图像分析系统,分析了玉米品种中单909在3个氮素水平条件下分别于9叶展时期、抽雄期和灌浆期的CC、11种色彩指数与植株LAI,DM,N%及产量之间的相关性,并对相关性显著的指标进行了拟合与建模。结果表明,CC与LAI(r=0.93,p<0.01),DM(r=0.94,p<0.01),N%(r=0.82,p<0.01)之间均达到了极显著水平;用CC估算LAI,DM和N%的模型均为幂函数,方程式分别是y=3.281 2x^(0.763 9),y=283.658 1x^(0.553 6),y=3.064 5x^(0.932 9);用与建模相独立的数据对模型验证,结果表明,CC估算LAI模型的实测值与模拟值基于1∶1直线的R^2,RMSE和RE分别是0.996,0.035和1.46%;CC估算DM模型的R^2,RMSE和RE分别是0.978,5.408g和2.43%;CC估算N%模型的R^2,RMSE和RE分别是0.990,0.054和2.62%。综上所述,模型能够较准确的通过CC估算不同氮肥水平条件下玉米9叶展时期、抽雄期和灌浆期的LAI,DM与N%,表明应用数码相机的光谱信息可实现对玉米生长过程中的生长状况及氮素营养状态进行实时无损快速监测与预测。

关键词：光谱玉米冠层覆盖度色彩指数叶面积指数冠层干重氮素含量

Endoscopic ear surgery in middle ear cholesteatoma

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Laparoscopic, Endoscopic and Robotic Surgery 2021年第1期4卷 24-29页

作者： Satish Nair J.G.Aishwarya Nagamani Warrier V Pavithra Aditya Jain Mehrin shamim Krishna Ramanathan Pooja K.Vasu Department of ENT-HNS Apollo HospitalsBangaloreKarnatakaIndia

Objective:Endoscope has been used as diagnostic tool for recidivism and as an adjunct to microscopic technique in the management of *** present transcanal endoscopic ear surgery(TEES)is being used as a minimally invasive alternative for microscopic *** aim to evaluate the feasibility,structural,functional and quality of life outcomes of endoscopic technique in middle ear ***:This prospective study was conducted at a tertiary care hospital from January 2017 to January 2018 including 32 adult patients who were treated by TEES for middle ear *** of endoscopic technique was assessed by the conversion rates,visualization of middle ear structures and *** outcomes were evaluated in terms of graft uptake at the third month follow-up and presence of residual or recurrent *** outcomes were evaluated in terms of postoperative air-bone gap closure at third month *** outcomes in terms of post-operative pain,cosmetic score,day of return to daily activities and patient comfort scores were *** quality of life outcomes were evaluated using chronic ear survey(CES)and short form questionnaire12 version 2(SF-12V2)which are disease specific and general quality of life assessment tools ***:Out of 32 patients,endoscopic intact canal wall mastoidectomy was done for 28 and endoscopic canal wall down mastoidectomy in 4 ***(3.1%)patient had to be converted to microscopic *** follow-up period was 32.8 months(9e46 months).There were no post-operative complications in any of our *** mean middle ear structural visibility index score was 8.4±1.4 with the use of zero-degree *** uptake rate at third month follow-up was 100%.Two(6.3%)patients had recurrent disease at 6 months follow-up and were treated by revision endoscopic *** air conduction(51.3±20.2 dB vs.34.5±20.4 dB,p<0.001),and air-bone gap(33.5±11.1 dB vs.16

关键词： Middle ear cholesteatoma Endoscopic technique Transcanal endoscopic ear surgery

Studies of lead toxicity on inflammatory damage and innate immune functions in testicular macrophages of male Swiss albino mice

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modern Research in Inflammation 2013年第4期2卷 75-81页

作者： shamim Ahmed S.K. Barbhuiya Sumana Chakraborty Mahuya Sengupta Department of Biotechnology Assam University Silchar India

Immune infertility has gained impetus in recent years. Various scientific studies have been carried out on the toxic effects of lead on immune function;however, uncertainties still persist. The present study addresses the immunomodulatory effects of testicular macrophages caused due to lead exposure (in-vivo). In mice, lead has a primary effect on the testes, and acts at all levels of the reproductive as well as the testicular immune response. The study was undertaken to investigate the effects of lead acetate on immune system in Swiss albino mice and the underlying mechanism of pro-inflammatory cytokine action. The immunomodulatory effects of lead are complex and appear to involve multiple pathways, not all of which are fully understood. Testicular macrophage dysfunctions by lead was studied by calculating morphological alteration and associated cell functions of innate immunity followed by estimation of pro-inflammatory cytokine release (TNF-α). The present work shows that lead is responsible for a significant morphological alteration, reducing cell function in testicular macrophages probably by increasing oxidative damage whereas increase in TNF-α release was also observed which increased inflammation. Results demonstrated that lead intoxication leads to increase in pro-inflammatory response. TNF-α is probably unable to bind with the surface receptor in testicular macrophages because of altered morphology which reduces cell function and ultimately causes reproductive dysfunction.

关键词： Lead Phagocytosis Intracellular Killing Scanning Electron Microscopy Proinflammatory Cytokines

Mortality characteristics during the two waves of COVID-19 in India:A retrospective observational study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Acute Disease 2022年第2期11卷 77-84页

作者： Nalini Ramesh Humaney Shilpa Sachin Kuthe shamim Akhtar Vivek K Pande Department of Medicine Nkpsims and Lata Mangeshkar HospitalNagpurIndia

Objective:To evaluate patient demographic characteristics and risk factors for mortality during the first and the second wave among COVID-19 patients in a tertiary care hospital of ***:Data were taken from the hospital’s electronic system for COVID-19 patients from August 2020 to December 2020,and the second from January 2021 to May *** mortality rate,demographic and clinical characteristics,laboratory profile,and reasons for the death of the two waves were retrieved and compared,and the risk factors of the two waves were ***:In the first wave,1177 COVID-19 cases visited the hospital and 96(8.2%)*** comparison,the death rate in the second wave was significantly higher(244/2038,12.0%)(P<0.001).No significant difference in age[60(50-69)vs.60.5(53-70),P=0.11]or gender(P=0.34)was observed between the two *** to the first *** were significantly more cases with fever,cough,weakness,loss of taste and smell,and sore throat during the second wave(P<0.05),but significantly fewer cases with kidney disease(6.6%vs.13.5%,P=0.038)and diabetes mellitus(35.7%vs.50.0%,P=0.015).Besides,during the second wave,more patients had abnormal X-ray findings,higher levels of lymphocytes and serum ferritin(P<0.05).In addition,there were significant differences in the rate of death cases with acidosis,septic shock,acute kidney injury,diabetes mellitus,cardiovascular events,hypothyroidism(P<0.05).Multivariate regression showed that during the first wave,age(OR:1.10;95%CI:1.02-1.21),diabetes mellitus(OR:3.16;95%CI:2.08-3.53),and abnormal X-ray(2.67;95%CI:2.32-2.87)were significant independent risk factors of mortality;while in the second wave,age(OR:1.13;95%CI:1.12-1.28),diabetes mellitus(OR:8.98;95%CI:1.79-45.67),abnormal X-ray(OR:12.83;95%CI:2.32-54.76),high D-dimer(OR:10.89;95%CI:1.56-134.53),and high IL-6(OR:7.89;95%CI:1.18-47.82)were significant independent risk factors of ***:Overall mortality and incidence of severe diseas

关键词： SARS-COV-2 COVID-19 Second wave First wave Pandemic