检索结果-南通市图书馆

A Study on the radioactivity Level in raw Materials, Final Products and Wastes of the Phosphate Fertilizer Industries in Bangladesh

引用

Journal of Environmental Protection 2012年第10期3卷 1393-1402页

作者： md. Abdus Samad md. Abu Haydar md. Idris Ali Debasish Paul md. Mahbubur R. Bhuiyan Sheikh Mohammad A. Islam Department of Physics Comilla University Comilla Bangladesh Department of Physics Jahangirnagar University Savar Bangladesh Health Physics and radioactive Waste Management Unit Institute of Nuclear Science and Technology Atomic Energy Research Establishment Savar Bangladesh

A study on the detection of probable radionuclides and their activity concentrations in the raw material (phosphate rock), final product (fertilizer) and waste samples collected from all the phosphate fertilizer factories (total two factories—A Diammonium Phosphate, DAP and a Triple Super Phosphate, TSP factory) in Bangladesh were carried out. A total of seven types of samples (grossly divided into solid and liquid types);liquid waste, waste-mixed river water, normal river water, phosphate rock, phosphate fertilizer, solid waste and normal soil;were analyzed under this study. raw material samples were collected only from the TSP fertilizer factory. Fertilizer, solid and liquid waste samples were collected from both the factories under study. Moreover, normal soil and natural surface water samples from the suitable areas adjacent to the factories were also collected for the comparison purpose. The samples were analyzed by gamma ray spectrometry technique using a Hyper-Pure Germanium (HPGe) detector of 40% relative efficiency. The analysis of the samples showed that only natural radionuclides such as 226ra, 232Th and 40K were present in the samples and no traces of artificial radioactivity were found in any of the samples. 40K was found below the detection limit in some samples. The analysis of the samples in the case of TSP fertilizer factory showed that the average activity concentrations of 226ra and 232Th and 40K in raw materials were 851.27 ± 7.10, 19.63 ± 6.57 and 54.06 ± 5.93 Bq/kg, respectively, in final product 211.90 ± 4.74, 42.48 ± 10.56 Bq/kg and ND (Not Detected), respectively, in solid waste 187.49 ± 4.88, 70.06 ± 11.76 and 289.27 ± 40.24 Bq/kg, respectively and in liquid waste 6.26 ± 0.63, 10.01 ± 1.39 Bq/L and ND, respectively. The measured results in the case of samples collected from DAP fertilizer factory showed that the average activity concentrations of 226ra and 232Th and 40K in the final product were 17.31 ± 3.92, 69.74 ± 9.88 and 48.46 ± 17.22

关键词： raw Materials radioactivity Phosphate Fertilizers and HPGe Detector

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Finite Element Analysis of Magnetohydrodynamic Natural Convection within Semi-Circular Top Enclosure with Triangular Obstacles

引用

American Journal of Computational Mathematics 2022年第1期12卷 33-43页

作者： Arju Ara Runa md. Abdul Alim md. Shahidul Alam Kazi Humayun Kabir Department of Mathematics Bangladesh University of Engineering and Technology (BUET) Dhaka Bangladesh Department of Mathematics Mohammadpur Kendriya College Mohammadpur Dhaka Bangladesh

The phenomena of magneto-hydrodynamic natural convection in a two-dimensional semicircular top enclosure with triangular obstacle in the rectangular cavity were studied numerically. The governing differential equations are solved by using the most important method which is finite element method (weighted-residual method). The top wall is placed at cold Tc and bottom wall is heated Th. Here the sidewalls of the cavity assumed adiabatic. Also all the wall are occupied to be no-slip condition. A heated triangular obstacle is located at the center of the cavity. The study accomplished for Prandtl number Pr = 0.71;the rayleigh number ra = 103, 105, 5 × 105, 106 and for Hartmann number Ha = 0, 20, 50, 100. The results represent the streamlines, isotherms, velocity and temperature fields as well as local Nusselt number.

关键词： Natural Convection Finite Element Method Hartmann Number rayleigh Number Triangular Obstacle Numerical Solution

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect of Hartmann Number on Free Convective Flow of MHD Fluid in a Square Cavity with a Heated Cone of Different Orientation

引用

American Journal of Computational Mathematics 2018年第4期8卷 314-325页

作者： Saika Mahjabin md. Abdul Alim Department of Mathematics National University Gazipur Bangladesh Department of Mathematics Bangladesh University of Engineering & Technology Dhaka Bangladesh

This paper presents the effect of magnetic field, indicated by Hartmann number (Ha), on the free convective flow of Magneto-hydro-dynamic (MHD) fluid in a square cavity with a heated cone of different orientation. Although similar studies abound, the novelty of this work lies in the presence of the heated cone, whose orientation is varied at different angles. The mathematical model includes the system of governing mass, momentum and energy equations. The system is solved by finite element method. The calculations are performed for Prandtl number Pr = 0.71;the rayleigh number ra = 10, 1000, 100,000;and for Hartmann number Ha = 0, 20, 50, 100. The results are illustrated with streamlines, velocity profiles and isotherms. From the results, it is found that for the present configuration, magnetic field (Hartmann number) has no effect on the shape of the streamlines for low rayleigh numbers. However, for high values of ra, the effect of Ha becomes quite visible. Magnetic field affects the flow by retarding the fluid movement, and thus affects convective heat transfer. At low ra, the fluid movement and heat transfer rate are already slowing, thus impressing a magnetic field does not produce much effect. At high ra, fluid particles move at high velocity and change the stream lines, in absence of any magnetic force. Impressing magnetic field in this situation produced noticeable effect by slowing down the fluid movement and changing the streamlines back to low ra situations. It is noted that a combination of low ra with zero or low Ha produces similar effects with the combination of high ra and high Ha. It can be concluded that with increasing Ha, heat transfer mode in MHD fluid gra.ua.ly changes toward conduction from convection. It can be surmised that sufficiently large Ha can potentially stop the fluid movement altogether. In that case, heat transfer would be fully by conduction.

关键词： MHD Free Convection Hartmann Number Square Cavity Heated Cone Finite Element Method

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Analyzing Nootropic Effect of Phyllanthus reticulatus Poir. on Cognitive Functions, Brain Antioxidant Enzymes and Acetylcholinesterase Activity against Aluminium-Induced Alzheimer’s Model in rats: Applicable for Controlling the Risk Factors of Alzheimer’s Disease

引用

Advances in Alzheimer's Disease 2016年第3期5卷 87-102页

作者： md. Sahab Uddin Abdullah Al Mamun Mohammed Ashraful Iqbal Ariful Islam md. Farhad Hossain Sayema Khanum Mamunur rashid Department of Pharmacy Southeast University Dhaka Bangladesh Department of Chemistry Fareast International University Dhaka Bangladesh Department of Pharmacy State University of Bangladesh Dhaka Bangladesh Department of Pharmacy University of Rajshahi Rajshahi Bangladesh

Oxidative stress is intensely linked with neurodegenerative disorders, especially Alzheimer’s disease (AD). Searching for medicinal plant with the nootropic activity for controling the development and progression of AD has received extensive consideration. The plant Phyllanthus reticulatus (PR) Poir. is known in Bengali as Panjuli belongs to family Euphorbiaceae. Previous studies have shown the antioxidant, analgesic, anti-inflammatory, etc. activities of this plant. Therefore, the objective of this study was to examine the nootropic effect of ethanolic extracts of Phyllanthus reticulatus (EEPR) on cognitive functions, brain antioxidatant enzymes and acetylcholinesterase activity in aluminium-induced rats of cognitive impairment and oxidative stress. The effects of EEPR fruit (i.e., 100 and 200 mg/kg b.w.) were examined for 30 days and its nootropic effect was determined in aluminium treated Swiss albino male rats by behavioral studies such as Passive Avoidance (PA) test, Rewarded Alternation (ra) test and biochemical studies such as superoxide dismutase (SOD), catalase (CAT), contents of thiobarbituric acid reactive substances (TBARS) and acetylcholinesterase (AChE) activity in rats brain tissue homogenates. In PA test, administration of EEPR fruit (i.e., 100 and 200 mg/kg, b.w.) significantly (P rats on 30th day with respect to disease control group. The percentage of memory retention (MR) for this test was pointedly (P rats treated with EEPR fruit (i.e., 200 mg/kg b.w.) as compared with disease control group. For ra test, EEPR fruit (i.e., 200 mg/kg b.w.) markedly (P rats on 30th day related to disease control group. In case of this test the percentage of MR was significantly (P rats treated with EEPR fruit (i.e., 100 and 200 mg/kg b.w.) with respect to disease control group. Administration of EEPR fruit (i.

关键词： Nootropic Phyllanthus reticulatus Cognitive Functions Brain Antioxidant Enzymes Acetylcholinesterase Activity Alzheimer’s Disease

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Finite Element Analysis of Magnetohydrodynamic Mixed Convection in a Lid-Driven Trapezoidal Enclosure Having Heated Triangular Block

引用

American Journal of Computational Mathematics 2020年第3期10卷 441-459页

作者： Muhammad Sajjad Hossain md. Abdul Alim Laek Sazzad Andallah Department of Arts and Sciences Ahsanullah University of Science & Technology (AUST) Dhaka Bangladesh Department of Mathematics Bangladesh University of Engineering & Technology (BUET) Dhaka Bangladesh Department of Mathematics Jahangirnagar University Dhaka Bangladesh

A numerical research on magnetohydrodynamic mixed convection flow in a lid-driven trapezoidal enclosure at non-uniform heating of bottom wall has been studied numerically. The enclosure consists of insulated top wall and cold side walls, too. It also contains a heated triangular block (Rot = 0° - 90°) located somewhere inside the enclosure. The boundary top wall of the enclosure is moving through uniform speed U0. The geometry of the model has been represented mathematically by coupled governing equations in accordance with proper boundary conditions and then a two-dimensional Galerkin finite element based numerical approach has been adopted to solve this paper. The numerical computations have been carried out for the wide range of parameters Prandtl number (0.5 ≤ Pr ≤ 2), Reynolds number (60 ≤ Re ≤ 120), rayleigh number (ra = 103) and Hartmann number (Ha = 20) taking with different rotations of heated triangular block. The results have been shown in the form of streamlines, temperature patterns or isotherms, average Nusselt number and average bulk temperature of the fluid in the enclosure at non-uniform heating of bottom wall. It is also indicated that both the streamlines, isotherm patterns strongly depend on the aforesaid governing parameters and location of the triangular block but the thermal conductivity of the triangular block has a noteworthy role on the isotherm pattern lines. Moreover, the variation of Nuav of hot bottom wall and θav in the enclosure is demonstrated here to show the characteristics of heat transfer in the enclosure.

关键词： Mixed Convection Magentohydrodynamic Finite Element Method Trapezoidal Enclosure Triangular Block Non-Uniform Heating

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Statistical data driven approach of COVID-19 in Ecuador: R_(0) and R_(t) estimation via new method

引用

Infectious Disease Modelling 2021年第1期6卷 232-243页

作者： raúl Patricio Fernandez-Naranjo MSc Eduardo Vasconez-Gonzalez md.Katherine Simbana-Riveramd.MSc Lenin Gomez-Barreno md.Juan S.Izquierdo-Condoy md.Domenica Cevallos-Robalinomd.MPH(c) Esteban Ortiz-Prado md.MSc,MPH One Health Research Group Faculty of MedicineUniversidad de las AmericasQuitoEcuador Resident of Intensive Care Unit Hospital Quito Sur IESSQuitoEcuador

The growth of COVID-19 pandemic throughout more than 213 countries around the world have put a lot of pressures on governments and health services to try to stop the rapid expansion of the *** 2009,H1N1 Influenza pandemic,statistical and mathematical methods were used to track how the virus spreads around *** of these models that were developed at the beginning of the XXI century are based on the classical susceptible-infected-recovered(SIR)model developed almost a hundred years *** evolution of this model allows us to forecast and compute basic and effective reproduction numbers(R_(t) and R_(0)),measures that quantify the epidemic potential of a pathogen and estimates different *** this study,we present a traditional estimation technique for R_(0) with statistical distributions by best fitting and a Bayesian approach based on continuous feed of prior distributions to obtain posterior distributions and computing real time R_(t).We use data from COVID-19 officially reported cases in Ecuador since the first confirmed case on February *** of the lack of data,in the case of R_(0) we compare two methods for the estimation of these parameters below exponential growth and maximum likelihood *** do not make any assumption about the evolution of cases due to limited information and we use previous methods to compare scenarios about R_(0) and in the case of R_(t) we used Bayesian inference to model uncertainty in contagious proposing a new modification to the well-known model of Bettencourt and Ribeiro based on a time window of m days to improve *** R_(0) with exponential growth criteria was 3.45 and with the maximum likelihood estimation method was *** results show that Guayas,Pichincha and Manabíwere the provinces with the highest number of cases due to *** reasons explain the increased transmissibility in these localities:massive events,population density,cities dispersion patterns,and

关键词： Bayesian inference R0 COVID-19 Real time reproduction factor Basic reproduction factor Ecuador

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

An Analysis for Distribution of Natural radionuclides in Soil, Sand and Sediment of Potenga Sea Beach Area of Chittagong, Bangladesh

引用

Journal of Environmental Protection 2014年第17期5卷 1553-1563页

作者： Sabina Yasmin Bijoy Sonker Ba.ua.Masud Kamal md. Abdur rashid Department of Physics Chittagong University of Engineering and Technology Chittagong Bangladesh Atomic Energy Centre Bangladesh Atomic Energy Commission Chittagong Bangladesh

A HPGe (High Purity Germanium) detector based, low background gamma-ray counting system was used for activity measurement in soil, sand and sediment samples collected from Potenga sea beach area of Chittagong, Bangladesh. The specific radioactivities of radium (226ra), Thorium (232Th) and Potassium (40K) were measured in the above samples. The investigation reflects the lower deposition of minerals exist in the collected samples. From the measured specific radioactivities of the above three natural radionuclides, the radium equivalent activity (raeq), the external hazard index (Hex), the external gamma absorbed dose rate and the annual effective dose were calculated. The obtained mean values of gamma absorbed dose rate in soil and sand samples and annual effective dose in soil, sand and sediment samples were found higher than the worldwide average as reported by United Nations Scientific Committee on the Effects of Atomic radiation (UNSCEAR, 2000). The raeq values were in the range of 47.86 to 293.76 Bq·kg-1 and the Hex varied from 0.13 - 0.81, which indicated that the study area was radiologically safe for human being.

关键词： Natural radioactivity Specific radioactivity HPGe γ-ray Detector radiation Hazard Index Dose rate Potenga Sea Beach

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Investigation of Heavy Metals and radionuclide’s Impact on Environment Due to The Waste Products of Different Iron Processing Industries in Chittagong, Bangladesh

引用

Journal of Environmental Protection 2017年第9期8卷 974-989页

作者： Mohammad Saifur rahman Bijoy Sonker Ba.ua.md. Rezaul Karim Masud Kamal Department of Chemistry Chittagong University of Engineering and Technology Chittagong Bangladesh Department of Civil Engineering Southern University Bangladesh Chittagong Bangladesh Bangladesh Atomic Energy Commission Dhaka Bangladesh

The waste products, such as induction furnace slag, ladle furnace slag, air pollution control dust, and ramming mass collected from major iron processing industries in Chittagong, Bangladesh were analyzed for heavy metals and naturally radioactive elements. The concentrations of heavy metals Fe, Cr, Mn, Co, Cd, Ni, Pb, Cu and Zn were obtained from atomic absorption spectrophotometer (AAS) analysis with flame atomizer and the radioactivities due to 226ra, 232Th and 40K were determined using high purity germanium (HPGe) detector of well shielded gamma-ray counting system. From the mean specific activities of the above three natural radionuclides in the investigated samples, the radium equivalent activity (raeq) and the external hazard index (Hex) were calculated. The study showed the prospect of contamination of environmental materials (viz., soil, water, air, plant) due to many of these investigated elements by using the collected waste products in landfill. The chemical process of ion exchange indicates that the elevated heavy metals in soil can play a role to increase the natural radioactivity of the soil. The obtained raeq as well as Hex indicated the insignificant radiation hazard due to the activities of primordial radionuclides found in the investigated samples.

关键词： Heavy Metals Natural radioactivity Slag Air Pollution Control Dust ramming Mass Iron Processing Industries

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Antitumor activity of Aponogeton undulatus against Ehrilich ascites carcinoma in Swiss albino mice

引用

Asian Pacific Journal of Tropical Medicine 2015年第6期8卷 431-438页

作者： md.Reyazul Islam md.BadrulAlam UmmeTamima Shayla Islam Jenny Department of Bioactive Materials Science Chonbuk National University567Baekje-daeroDeokjin-guJeonju-siJeollabuk-doRepublic of Korea Gra.ua.e School of Food Science & Biotechnology Kyungpook National University 80Daehak-raBuk-guDaeguRepublic of Korea Department of Pharmacy Atishlipankar University of Science & Technology College of Pharmacy Seoul National UniversityI Guanak-roGuanak-guSeoulRepublic of Korea

Objective:To investigate in vitro antioxidant and in vivo antitumor activity of the crude methanolic extract of Aponogeton undulatus(MAU) along with its various organic ***:Aponogeton undulatus leaves were successively extracted using methanol(MAU)and then fractionated by chloroform,ethyl acetate(EAU) and *** total antioxidant capacity,lipid peroxidation inhibition assay.1.1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging assay and ferrous reducing power assessment were used to eva.ua.e the antioxidant potential of the crude extract and its organic *** in vivo antitumor activity is eva.ua.ed against Ehrlich ascites carcinoma(EAC) cell bearing in Swiss albino ***:EAU showed the highest antioxidant capacity as(175.80±0.41)mg/g,IC_(50)value of DPPH scavenging activity was(38.84±0.02)μg/mL and also exhibited maximum lipid peroxidation inhibition activity with the IC_(50) value of(42.52±0.32)μg/mL than other *** results demonstrate that reducing power of the extract was concentration *** addition,EAU was administered at 50.100 and 200 mg/kg body weight respectively to EAC cell bearing mice and a significant(P<0.05)decrease in tumor volume,packed cell volume and viable cell count and also increased the life span(17.52% .42.53% and 62.05% ).Hematological profiles were restored to normal levels in MAU treated mice as compared to EAC control ***:The results were found to be significant and confirmed that the Aponogeton undulatus has remarkable antitumor activity with antioxidant potential.

关键词： Antioxidant Antitumor Ehrlich ascites carcinoma Aponogeton undulatus

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Status of Renal and Liver Function in Rheumatoid Arthritis (ra) Patients of Chattogram, Bangladesh Treated with Methotrexate (MTX)

引用

Journal of Biosciences and Medicines 2023年第9期11卷 114-126页

作者： Mohammad Ra.ua.ul Hoque md. Abdur razzaque Abrar Nafis Mohammad Shahriar Zawad Sharaf Wasima rahman Department of Biochemistry and Molecular Biology University of Chittagong Chattogram Bangladesh Department of Rheumatology Chittagong Medical College Hospital Chattogram Bangladesh

Rheumatoid Arthritis (ra) is a chronic autoimmune disorder that is usually manifested as inflammation in multiple joints and several extra-articular symptoms, involving the liver, kidney, eye, skin, blood, blood vessels, heart, lungs, nervous system, and other organs. Methotrexate (MTX) is the anchor drug that treats ra. As renal and liver abnormalities are more common during disease conditions as well as during the treatment period, we tried to find out if there is any impact of MTX in these organs during the treatment of ra patients. Once the disease complications are developed, it is quite difficult to reverse the disease, and treatment in this situation is not very effective. Consequently, patients suffer a lot. So, early eva.ua.ion of renal and liver function is essential for the treatment of ra patients and it might also help prevent different complications which are usually very frequently observed. This was a cross-sectional study. A total of 150 ra patients treated with MTX were eva.ua.ed for the study where female and male respondents were 115 and 35 respectively. In this study, we found that 82% of ra patients had creatinine levels ≤ 1.1 mg/dL although the normal range of serum creatinine is below 1.4 mg/dL. Usually, a 15% increase in Serum creatinine level from the baseline is considered renal impairment. We found 4% of such cases. Moreover, 2% of ra patients had creatinine levels above the normal range of 1.4 mg/dL and those patients were hypertensive as well. So, a total (4 + 2 = 6)% had renal impairments. Among them, 5% had diabetes mellitus. On the other hand, the ultrasonogram (USG) of ra patients with kidney disease showed signs of renal parenchymal disease and 3% of ra patients having renal problems whose serum creatinine level was within the normal range showed signs of chronic kidney disease (CKD). On the other hand, 2% of ra patients showed signs of hepatic parenchymal disease. In this study, 69% of ra patients had ALT levels ≤ 50 mg/dL, 23% ha

关键词： Rheumatoid Arthritis Renal Function Liver Function C-Reactive Protein Methotrexate

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：