检索结果-南通市图书馆

Assessment of the fraction of bed load concentration towards the sediment transport of a monsoon-dominated river basin of Eastern India

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 Geographical Sciences 2023年第5期33卷 1023-1054页

作者： KAR Rohan sarkar arindam School of Infrastructure Indian Institute of Technology BhubaneswarArgulKhordhaOdisha 752050India

Given the challenges of re-creating complex bed load(BL)transport processes in rivers,models are preferred over gathering and examining field *** highlight of the present research is to develop an approach to determine the ungauged bed load concentration(BLC_(u))utilizing the measured suspended sediment concentration(SSC)and hydraulic variables of the last four decades for the Mahanadi River *** technique employs shear stress and SSC equations for turbulent open channel ***,the predicted BLC_(u)is correlated with SSC using a power relation to estimate BLC_(u)on the river and ***,different BL functions(BLF)efficiency is assessed across *** model predicted BLC_(u)is comparable with the published data for sandy rivers and falls within±20%.Outliers in hydraulic and sedimentological statistics significantly influence estimating the BL fraction apart from higher relative ratios and catchment *** constants of power functions are physically linked to sediment transport configuration,mechanism,and inflow to the *** stream power-based BLF best predicts the BL transport,followed by shear stress and unit discharge *** disparity in the estimation of BLC_(u)results from station-specific physical factors,sampling data dispersion,and associated uncertainties.

关键词： Mahanadi River Basin ungauged bed load concentration suspended sediment concentration correlations bed load functions

维普期刊数据库

Analysis of flow over backward facing step with transition

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2015年第1期9卷 71-81页

作者： Dwarikanath RATHA arindam sarkar Civil Engineering Department Thapar University Patiala Punjab 147001 India School of Infrastructure Indian Institute of Technology Bhubaneswar 751013 India

The present study deals with the study of the velocity distribution and the separation phenomenon of flow of air over a two dimensional backward facing step. The flow of air over a backward facing step has been investigated numerically using FLUENT. Flow simulation has been carried out in a backward facing step having an expansion ratio （ratio of the height before and after the step） of 1：1.94 and the results obtained are compared with the published experimental results. Comparison of flow characteristics between steps with three different transitions is made. The variation ofreattachment length for all the three cases are analyzed for wide range of Reynolds number ranging from 100 to 7000 which covers the laminar, transition and turbulent flow of air. Simulation of the flow over steps with expansion ratios of 1：1.24, 1：1.38, 1：1.47, 1：1.53, 1：1.94, 1：2.20 are also carried out to examine the effect of different expansion ratios on the reattachment length. It is found that the primary reattachment length increases with increase in the expansion ratio. The primary reattachment length at the bottom wall downstream of the step is minimum for the step with round edged transition and maximum for the step with a vertical drop transition.

关键词： Reattachment length backward facing step transition flow separation k-ε model

维普期刊数据库

Sero diagnosis of dengue activity in an unknown febrile outbreak at the Siliguri Town,District Darjeeling,West Bengal

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2010年第5期3卷 364-366页

作者： Debjani Taraphdar arindam sarkar Mihir Kumar Bhattacharya Shyamalendu Chatterjee ICMR virus unit GB-41st FloorID & BG Hospital57Dr.S.C.Banerjee RoadBeliaghataKolkata-700010 India National Institute of Cholera and Enteric Diseases P-33 C.I.T.RoadScheme XMBeliaghataKolkataIndia

Objective:To investigate the outbreak of unknown fever at Siliguri town,Darjeeling District on request from the State Health Department,Government of West ***: Investigations were made to the affected wards,Sub Divisional Hospital and the nursing homes of Siliguri *** of illness was 3-5 *** observations were made in some cases which had gastrointestinal disorders with high serum glutamate pyruvate transaminase(SGPT) and serum glutamic oxaloacetic transaminase(SCOT) levels.A total of 69 blood samples and 7 throat swabs(in Minimum Essential Media) were collected and brought to the ICMR Virus Unit, Kolkata for *** from different affected areas were collected for the identification of the definite ***:Amongst the 69 blood samples,42(60.86%) were positive to IgM antibody against dengue virus by Mac enzyme-linked immunosorbent assay(ELISA) *** IgM antibody to Japanese encephalitis virus was detected among the collected blood *** on the clinical symptoms,presence of IgM antibody to dengue virus and identification of Aedes mosquito,it amply proves that,the illness of those cases were due to dengue virus infection. Conclusions:Based on clinical-epidemiological observations of the investigations the possibility of a communicable disease of viral origin,the detection of IgM antibody and the identification of Aedes egypti,and the potential circulation of denge virus in Siliguri town for the first time were all suggested.

关键词： Sero diagnosis Dengue Febrile West Bengal

Mass scale screening of common arboviral infections by an affordable,cost effective RT-PCR method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2012年第2期2卷 97-101页

作者： Debjani Taraphdar arindam sarkar Shyamalendu Chatterjee Indian Council of Medical Research Virus Unit

Objective:To develop a rapid,cost effective RT-PCR method for the mass scale diagnosis of such diseases at the vireraia stage to find out the actual disease burden in that ***:For this purpose,cases with the history of only short febrile illness were *** 157 samples with the history of dengue/chikungunya like illness and only 58 samples with a history of acute encephalitis syndrome(AES)were ***:Out of 157 samples,42 and 74 were detected as dengue and chikungunya,respectively and out of 58 AES cases only 23 could be detected as Japanese encephalitis by this RT-PCR ***:This cost effective RT-PCR method can detect the total positive cases that remain undetected by EL1SA ***,this method is capable to detect the viral RNA from patients'sera even after the appearance of IgM antibody at one fifth costs as compared with the other commercially available kits.

关键词： Cost effective RT-PCR method Mass screening Arbovirus

Soil Geomorphology of Garpanchkot Hill Area and Its Influence on Land Use and Land Cover

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 Geoscience and Environment Protection 2019年第7期7卷 108-135页

作者： arindam sarkar Department of Geography P.K.H.N. College Howrah India Department of Geography University of Calcutta Kolkata India

The present study is about to find out different attributes of soil as well as geomorphology. It is very much relevant to the study of land use land cover (LULC). Garpanchkot hill is situated in Purulia district of West Bengal. There are two geomorphological and seven pedological parameters that have been selected for the study. Shuttle radar topographic mission (SRTM) and advanced land observing satellite (ALOS) data are analyzed by remote sensing software to find out the geomorphological character of the area. There are twenty soil samples that have been taken from top of the hill to foothill pediment area with the change of elevation and slope for laboratory analysis. Different statistical techniques are used for representation. Foot hill area of the Garpanchkot hill can be determined by less than 150 m elevation and 5o slope. Elevation and slope of rest of the hill area (greater than 150 m and 5o) are fully dominated by forest and scattered vegetation. Elevated area (greater than 205 m) with less slope (10o - 15o) is associated with dense forest. Escarpment area is associated with grass land and scattered vegetation. Foothill area is bearing the signature of scattered vegetation, bare soil ground and agriculture. The richness of clay minerals plays an important role in the foothill pediment area for development of agriculture. Sandy loam is dominating soil texture in the rest of the hill area. Percentage of organic matter (1.8%), status of salinity (6.65 - 7.72) and alkalinity (up to 138.6 μs/cm) remain high in the high elevated area due to forest cover. The area is very dry, only fed by the rainfall during monsoon season. Artificial reservoir feeds the foothill agriculture system. Rice, wheat, maize, sugarcane, pulses chili and vegetables are the main crops of this area.

关键词： Soil Geomorphology Foothill Agriculture Forest Sandy Loam

Temporal Evolution of Scour at Submerged Circular Cylinders

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 Marine Science and Application 2021年第1期20卷 85-101页

作者： Abhijit Rout arindam sarkar Indian Institute of Technology Bhubaneswar ArgulJatniOdisha 752050India

Temporal evolutions of scour at submerged circular cylinders were *** visualization was carried out around the cylinders over plane,under developed and equilibrium scour *** analysis technique was used to formulate the equations for determining the diameter of the horseshoe vortex around the submerged cylinders,which is also verified from the vector diagrams drawn using the velocity *** scour process similar to live bed scour was noticed around the downstream *** diameter of the horseshoe vortex is found to depend on the diameter of respective cylinder,submergence ratio,spacing between the cylinders and skew *** formulation along with the dislodgement and transportation of a single sediment particle is further incorporated in the proposed model for determining the time variation of scour around the submerged *** is evident from the results that the upstream cylinder shelters the downstream cylinder and thereby reduces the scour at the downstream *** model is further extended to incorporate the effect of non-uniformity of the sediment particles on the time variation of scour *** results indicate significant reduction of scour depth of around 6%and 35%for upstream and downstream cylinders respectively due to the formation of the armor *** model is also compared with the local scour component of field data around cylindrical bridge piers to establish the differences in the scour process around a partially submerged cylinder and fully submerged tandem and skewed cylinders.

关键词： Scour Tandem Skewed Submerged cylinder Sediment Time variation

维普期刊数据库

REVIEW ON LOCAL SCOUR DUE TO JETS

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2004年第3期19卷 210-238页

作者： arindam sarkar,Subhasish DEY Doctoral Research Fellow Department of Civil Engineering Indian Institute of Technology Kharagpur 721302 West Bengal India. Associate Professor Department of Civil Engineering Indian Institute of Technology Kharagpur 721302 West Bengal India.

The safety of an apron of the energy dissipator is threatened by the large-scale scour in the downstream of the apron due to the erosive action of a horizontal jet issuing from a sluice opening. Also, large-scale deposition of the scoured sediments due to an impinging jet in a plunging pool type energy dissipator affects the passage of flow adversely in the downstream channels. Owing to the significant practical importance, the problem of local scour due to jets has been studied by many investigators. In this paper, a comprehensive review of the up-to-date investigations on local scour due to horizontal and impinging jets is presented including all possible aspects, such as scouring process, parameters affecting scour, time variation of scour, velocity distribution on the apron and within the scour hole, development of boundary layer thickness, bed shear stress, scour estimation formulas and protection works.

关键词： Scour Erosion Sediment transport Jets

Influence of socio-economic status and environmental factors on serologically diagnosed Japanese encephalitis cases in the state of West Bengal, India during 2005-2010

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Health 2012年第1期4卷 6-12页

作者： arindam sarkar Debjani Taraphdar Bansi B. Mukhopadhyay Manish Kumar Subhra K. Mukhopadhyay Shyamalendu Chatterjee 不详

Objectives: The main aim of the current study is to examine the influence of socio-economic status and environmental factors on serologically diagnosed Japanese encephalitis cases in the state of West Bengal, India during 2005-2010. Materials and methods: A total of 648 blood/CSF specimens were collected and/or referred from the suspected AES cases, admitted in the different medical colleges and hospitals of the state during the year of 2005-2010. These specimens were subjected to JE Mac ELISA to determine the actual JE case amongst these AES. The association of the socio-economic status and environmental factors with the serologically diagnosed JE positive cases was studied by a statistical analysis through Normal Deviate test or Z test. Result: Out of 648 specimens, only 175 (27.0%) specimens were reactive to JE IgM antibody, of which 60.0% were from the male individuals and 40.0% from the female population. Major cases were observed in the age group of 0 - 10 years;followed by 11 - 20 years. Regarding literacy, only 58.3% cases had no education and 41.7% were from the literate with varying level of education, i.e., from primary level to post gra- duate level. A total of 65.7% cases were from low income group where as only 34.3% cases were from high income group. Regarding house type, 62.3% cases lived in mud house and 37.7% cases lived in the brick house. In most of the cases (74.3%), persons were living in close proximity to rice fields/lakes/ponds. 69.7% cases were found to occur in the monsoon and post-monsoon period whereas 30.3% cases were reported in the pre-monsoon period. Conclusion: Our study concludes that socio-economic status and environmental conditions were statistically significant contextual risk factors for serologically diagnosed JE incidences in West Bengal where JE is proved to be endemic in nature and such study constitutes a new report of this kind in the region.

关键词： Japanese Encephalitis Socio-Economic Status Acute Encephalitis Syndrome (AES) West Bengal

Production of fermented tea petal decoction with insights into in vitrobiochemical tests,antioxidant assay and GC-MS analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Food Production, Processing and Nutrition 2021年第1期3卷 406-415页

作者： Soumya Majumder Sumedha Saha arindam Ghosh Sukanya Acharyya Sahadeb sarkar Sourav Chakraborty Malay Bhattacharya Molecular Biology and Tissue Culture Laboratory Department of Tea ScienceUniversity of North BengalSiliguriDarjeelingWest Bengal Pin-734013India

This research work was designed to attempt and propose the first report on production and biochemical characterization of fermented tea flower petal decoction or simply tea petal *** tea petal decoction and brewer’s yeast or Saccharomyces cerevisiae were co-cultured for *** activity and chromatographic separation of potential candidates were *** investigations for qualitative characters on this fermented broth revealed the presence of steroids,tannin,flavonoids,phenol,cardiac glycosides,coumarin,caffeine *** manufactured fermented broth showed high free radical scavenging activity after 2 months of *** DPPH scavenging activities were also observed in solvent fractions of acetone,ethanol and *** antioxidant activity,alcohol percentage and other qualities were seen to be gradually increased during *** chromatography-mass spectrometry analysis revealed the presence of 44 compounds including many potential antioxidant molecules and other bioactive ***,presence of alcohol with medicinally active compounds and antioxidant activity will make it as acceptable as a good wine and tea flower as economically functional.

关键词： Tea petal Antioxidant GC-MS Fermentation brewer’s yeast