Dhaka University Journal of Science最新文献_第4页

Availability of Adequately Iodized Salt Consumption and its Association with Socio-Economic Factors in Bangladesh 孟加拉国充足碘盐消费的可得性及其与社会经济因素的关系

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62598

Md. Akter Hosen, Rownak Jahan Tamanna

引用次数: 0

A Variant of the RSA Cryptosystem with Smaller Keys 具有较小密钥的RSA密码系统的一种变体

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62600

DM Zunayed Kamal Nibir, S. Nasrin, S. M. S. Rana

引用次数: 0

Conformal Killing Vector Fields of Riemannian Manifolds 黎曼流形的共形杀伤向量场

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62601

Md Shapan Miah, Khondokar M. Ahmed

引用次数: 0

Jute Fiber Reinforced Hydrogel Composite for Removal of Methylene Blue Dye from Water 黄麻纤维增强水凝胶复合材料去除水中亚甲基蓝染料

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62608

Ajadur Rahman Shakil, Most Laboni Begum, Md. Aftab Ali Shaikh, S. Sultana, M. Rahman, Md. Mahamudul Hasan Rumon, C. Roy, Md Anamul Haque

{"title":"Jute Fiber Reinforced Hydrogel Composite for Removal of Methylene Blue Dye from Water","authors":"Ajadur Rahman Shakil, Most Laboni Begum, Md. Aftab Ali Shaikh, S. Sultana, M. Rahman, Md. Mahamudul Hasan Rumon, C. Roy, Md Anamul Haque","doi":"10.3329/dujs.v70i2.62608","DOIUrl":"https://doi.org/10.3329/dujs.v70i2.62608","url":null,"abstract":"In this study, a hydrogel composite based on natural jute fiber (JF) has been prepared and employed for the removal of methylene blue (MB) dye from aqueous solution. Polyacrylamide (PAAm) hydrogel was synthesized by thermal polymerization in presence of N,N□-methylene bisacrylamide (MBAA) as the cross-linker and potassium per sulfate (KPS) as the initiator. JF reinforced hydrogel (JFRH) composite was prepared by incorporating JF into PAAm matrix prior to the polymerization. The prepared JFRH was characterized by FTIR spectroscopy and scanning electron microscope. It was found that, JFRH composite demonstrated strong mechanical properties with a compressive strength of 1.5 MPa at a deformation of above 80%. The prepared JFRH composite can remove more than 90% of MB from an aqueous solution and be separated easily from the solution after the adsorption process. Therefore, the synthesized JF based hydrogel composite could significantly expand the use of our natural golden fiber for reinforcement of composite materials and removal of dyes from water bodies.\u0000Dhaka Univ. J. Sci. 70(2): 59-64, 2022 (July)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81364834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Production, Characterization and Evaluation of Pyrolysis Oil from Tyre Wastes Available in Bangladesh 孟加拉国轮胎废弃物热解油的生产、表征和评价

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62603

Md Galib Mahmud, M. S. Islam, Tanvir Ahmed, M. E. Halim, M. Ismail

{"title":"Production, Characterization and Evaluation of Pyrolysis Oil from Tyre Wastes Available in Bangladesh","authors":"Md Galib Mahmud, M. S. Islam, Tanvir Ahmed, M. E. Halim, M. Ismail","doi":"10.3329/dujs.v70i2.62603","DOIUrl":"https://doi.org/10.3329/dujs.v70i2.62603","url":null,"abstract":"Globally, scrap tyres are increasing due to the increased number of vehicles. In contrast, in the recent years, alternatives to fossil fuels are exploring to overcome the fossil fuel crisis. In this study, pyrolysis of bicycle and rickshaw tyres wastes was conducted and parametric effects (e.g., the effect of temperature, feed size and apparent vapor residence time etc.) on the pyrolysis product yields were determined. A fixed bed electric heating reactor was used for pyrolysis at 400 - 550 oC, maintaining various particles sizes and a constant heating rate of 20oC/min. The optimum Tyre Pyrolysis Oil (TPO) yield of 42 wt.% was obtained at 500 oC for a sample size of 4.0 cm3. The fuel properties (e.g., density, viscosity, calorific value, flash point, pour point, sulphur content, ash content etc.), functional group studies of the TPO were determined and was compared with the conventional fuel and with international standards. The physico-chemical properties of TPO confirm the use of TPO as furnace oil in various industrial processes. The fractionation of bio-oil gives various value added products including bio-gasoline, bio-kerosene and others chemicals. The commercial implementation of the pyrolysis and follow-up technologies for waste tires processing will allow energetic valorization of waste tyres in Bangladesh.\u0000Dhaka Univ. J. Sci. 70(2): 29-34, 2022 (July)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"14 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72741121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Assessment of Nutritional Value of Limonia acidissima L. (Wood Apple) 酸柠檬(Limonia acidissima L.)的营养价值评价

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62606

Mohsina Jiban Dyuti, R. Afroz, M. Shoeb

{"title":"Assessment of Nutritional Value of Limonia acidissima L. (Wood Apple)","authors":"Mohsina Jiban Dyuti, R. Afroz, M. Shoeb","doi":"10.3329/dujs.v70i2.62606","DOIUrl":"https://doi.org/10.3329/dujs.v70i2.62606","url":null,"abstract":"The objective of the study was to investigate Limonia acidissima L. (wood apple) to determine the moisture and ash content, total amount of carbohydrates, fatty acid compositions, the quantity of protein and micronutrients (Na, K, Zn, Fe) present in wood apple grown in Bangladesh. FT-IR spectroscopy was used to pinpoint many biologically significant functional groups. The moisture and ash content obtained were 74.02 and 25.44%, respectively. Carbohydrate content determined by ultraviolet-visible (UV-Visible) spectroscopic method was 16.14 g per 100 g of dried fruit sample. The fatty acids were identified by Gas Chromatography-Flame Ionization Detector (GC-FID). The relative percentage of bound fatty acids mainly palmitoleic acid, octadecanoic acid, cis-9-oleic acid and octanoic acid were 17.33, 15.09, 15.09 and 45.09%, respectively. The amount of protein was 5.11%. The micronutrients such as Na, K, Zn, Fe present in the edible portion of wood apple measured by atomic absorption spectroscopy (AAS) were 10.40, 58.24, 0.37 and 1.67 mg per 100 g of dried sample, respectively. The fruit has long been utilized in herbal medicines and is eaten raw or processed into various products to prevent noncommunicable diseases and micronutrient deficiencies.\u0000Dhaka Univ. J. Sci. 70(2): 48-52, 2022 (July)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"165 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73138541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optical and Structural Study of the CZTS (Cu2ZnSnS4) Thin Film for Solar Cell Derived from the Chloride-Based sol-gel Precursor Solution 氯基溶胶-凝胶前驱体制备太阳能电池用CZTS (Cu2ZnSnS4)薄膜的光学和结构研究

Dhaka University Journal of Science Pub Date : 2022-07-24 DOI: 10.3329/dujs.v70i1.60374

M. Rahman, M. Bashar, N. Islam

引用次数: 2

Determination of Toxic Heavy Metal Contents of Some Selected Tropical Fruits Grown in Industrial Areas of Bangladesh 孟加拉工业地区某些热带水果中有毒重金属含量的测定

Dhaka University Journal of Science Pub Date : 2022-07-24 DOI: 10.3329/dujs.v70i1.60377

Md. Ashraful Islam, Maksuda Parvin, Md. Fahad Bin Quader, Md. Shakhawat Hossain

{"title":"Determination of Toxic Heavy Metal Contents of Some Selected Tropical Fruits Grown in Industrial Areas of Bangladesh","authors":"Md. Ashraful Islam, Maksuda Parvin, Md. Fahad Bin Quader, Md. Shakhawat Hossain","doi":"10.3329/dujs.v70i1.60377","DOIUrl":"https://doi.org/10.3329/dujs.v70i1.60377","url":null,"abstract":"Fourteen tropical fruit items were collected from different industrial sites of the Dhaka and Chattogram region, Bangladesh todetermine toxic heavy metal contents. This study aimed at the assessment of the distribution of heavy metals (As, Pb and Cr) as wellas comparison of their level among different locations. The fruit items were analyzed for the quantiﬁcation of the selected heavymetals using Atomic Absorption Spectrophotometer (AAS). The range of lead, chromium and arsenic in the fruit items were 1.12± 0.077 to 2.899 ± 0.013, 0 to 0.217 ± 0.005 and 0 to 0.078 ± 0.002 mg kg-1 respectively. It was revealed from the results that thelevel of toxic metals (As, Cr) in almost all fruit samples were within tolerable limit whereas the level of Pd in all of the fruit samplesexceeded the acceptable limits of WHO standard value. It was also observed from the results obtained that the concentration of themetals found in the samples from Dhaka regions were considerably higher than that of Chattogram. These metal contributors mainlyarising from anthropogenic sources including industrial wastes, automobile emissions, use of fertilizers, pesticides and herbicides inagriculture, paints, sewage and waste disposal. The extended level of these metals causing environmental pollution is hazardous sinceplants accumulate them. Subsequently, crops uptaking these heavy metals consumed by humans and animals which is detrimental tohealth. It is therefore very important that necessary actions need to be taken to monitor the level of these deleterious elements in foodplants. In decision making, planning and risk assessing this present study will play significant role. \u0000Dhaka Univ. J. Sci. 70(1): 22-27, 2022 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87195991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Simulation Based Temperature Profiling of Human Eye due to the Exposure of LED Light LED光照射下人眼温度分布的仿真研究

Dhaka University Journal of Science Pub Date : 2022-07-24 DOI: 10.3329/dujs.v70i1.60379

M. Rahman, M. Rabbani

引用次数: 0

Cu(II) Doped TiO2 for Photodegradation of Remazol Black B in Aqueous Solution Cu(II)掺杂TiO2光降解Remazol Black B的研究

Dhaka University Journal of Science Pub Date : 2022-07-24 DOI: 10.3329/dujs.v70i1.60383

M. Momen, M. Rahman, H. Begum, M. Hossain

{"title":"Cu(II) Doped TiO2 for Photodegradation of Remazol Black B in Aqueous Solution","authors":"M. Momen, M. Rahman, H. Begum, M. Hossain","doi":"10.3329/dujs.v70i1.60383","DOIUrl":"https://doi.org/10.3329/dujs.v70i1.60383","url":null,"abstract":"In the present investigation, Cu(II) doped TiO2 was prepared by a precipitation method. The precipitate was calcined at 300 ºC for2 hours. The prepared doped catalyst was characterized by scanning electron microscope (SEM), energy dispersive X-ray (EDX)spectroscopy and X-ray diffractometry (XRD). SEM images revealed that the morphology of the doped catalyst was different fromthat of TiO2. Elemental analysis was accomplished by EDX that indicated the presence of Cu, Ti and O atoms in the prepared sample.XRD analysis confirmed that TiO2 was present as anatase with almost no distortion in peak position due to the presence of Cu(II)in some interstitial sites. Photodegradation of remazol black B (RBB) was carried out at different experimental conditions underdifferent light sources. The catalytic efficiency of Cu(II) doped TiO2 increased up to a certain dosage then reduced with a furtherincrease in the amount of photocatalyst. The optimum conditions for degradation was found at pH 3.0 under UV light. Under theseexperimental conditions, Cu(II) doped TiO2 degraded 98.8% of RBB, on the other hand, undoped TiO2 degraded only 80.0% of RBB.\u0000Dhaka Univ. J. Sci. 70(1): 64-69, 2022 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87397664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0