Dhaka University Journal of Science最新文献

{"title":"Estimation of Potassium Bromate- an Alarming Carcinogen in Commercial Bread Samples Around Dhaka City","authors":"Nusrat Jahan Sima, Sagor Bisshas, Anik Rudra, Mohammad Shoeb, Abida Sultana","doi":"10.3329/dujs.v72i1.71027","DOIUrl":"https://doi.org/10.3329/dujs.v72i1.71027","url":null,"abstract":"The primary goal of this study was to determine the presence of potassium bromate in bread samples both qualitatively and quantitatively, as well as to investigate the composition of the bread (moisture, ash, and sugar contents). Thirty different commercial bread samples from different areas of Dhaka city were collected for analysis. The ultraviolet-visible spectrophotometric technique was employed in this study to estimate potassium bromate in bread samples. It was based on the redox interaction of bromate and promethazine hydrocloride in an acidic medium which generate a red-pink coloration with maximum absorbance at 515nm. The amount of potassium bromate was found in the range of 1.24 to 24.91µg/g. Moisture and ash content were found to be 15.37 to 29.8% and 1.75 to 2.94%, respectively. The total sugar content was determined by the ultraviolet-visible spectrophotometric method by the modified phenol-sulfuric acid test and the maximum absorbance was obtained at 489 nm. Total sugar content was found in different types of white bread samples ranging from 3.33 to 11.31g per 100g. The average recovery (n=5) of potassium bromate was 91.58 ± 5.61% at a dosage of 10 μg/mL.\u0000Dhaka Univ. J. Sci. 72(1): 1-6, 2024 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":" 795","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140382701","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}

{"title":"Implementing Vertices Principal Component Analysis under Various Weighting Schemes for Interval Valued Observations with Applications to Data Mining","authors":"Md Anwarul Islam Bhuiyan, S. Jahan, Mohammad Babul Hasan","doi":"10.3329/dujs.v72i1.71184","DOIUrl":"https://doi.org/10.3329/dujs.v72i1.71184","url":null,"abstract":"Data mining is the technique for deriving valuable data from a more extensive collection of raw data. It is the process of looking for irregularities, trends, and correlations in huge data sets in order to forecast results. Although a number of techniques have been developed to perform data mining on conventional data in the past years, there are huge scope to work with Interval Valued data (IVD). Working with IVD has been shown to be of significant importance when it comes to identifying the objective entity in a precise manner or representing incomplete knowledge on life situations. Unlike classical data where each object is represented by a point, in IVD the objects are represented by regions in Rp. In this paper, an extension of Principle Component Analysis (PCA) known as Vertices Principal Components method for interval-valued information has been explored. It additionally incorporated the relative contributions of the vertices depending on different choices of weighting schemes. A new idea for classification of the supervised IVD is proposed which is based on the idea of K-Nearest Neighbor (KNN) technique. The proposed approach is implemented on several benchmarking data sets. Numerical results suggest the proper choice of weighting schemes for each of the data set that will lead to better recognition rate.\u0000Dhaka Univ. J. Sci. 72(1): 46-55, 2024 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":" May","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383551","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}

{"title":"Assessing Goodness of Approximate Distributions for Inferences about Parameters in Nonlinear Regression Model","authors":"Md Jamil Hasan Karami","doi":"10.3329/dujs.v71i1.65267","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65267","url":null,"abstract":"It is often crucial to make inferences about parameters of a nonlinear regression model due to a dependency of Fisher information on the parameter being estimated. Here, the distribution of the relevant test statistic is not exact, but approximate. Therefore, similar conclusion, based on the values of different test statistics, may not be reached. This study shows, in this circumstance, how to come up with a nonlinear regression model that can be used for forecasting and other related purposes. The goodness of the approximate distributions, F and χ 2 , has been assessed to reach a correct decision. The simulation results show that the simulated probability of committing a type I error is very close to its true value in case of F distribution corresponding to F statistic. However, the χ 2 distribution does not do a similar job for the LRT statistic since the simulated type I error is quite larger.\u0000Dhaka Univ. J. Sci. 71(1): 13-16, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89364553","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}

{"title":"Crystal Field Splitting Energy (Δo) and Racah Parameters (B) of Some Metal-Saccharine and Metal-Saccharine-Ethylenediamine Complexes","authors":"S. Islam, H. Akter, P. K. Bakshi","doi":"10.3329/dujs.v71i1.65266","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65266","url":null,"abstract":"[M(sac)2(H2O)4].2H2O [sac = saccharinato anion, M = Fe(II), Co(II), Ni(II), and Cu(II)], and [M(sac)2(en)2].2H2O [sac = saccharinato anion, en = ethylenediamine, M = Fe(II), Co(II), Ni(II) and Cu(II)] were prepared in an aqueous medium. The compounds are crystalline of different colors and are ambiently stable. By examining their physico-chemical properties and relevant literature, the metal(II) ions in both [M(sac)2(H2O)4].2H2O and [M(sac)2(en)2].2H2O complexes are octahedrally coordinated. In the former by four neutral H2O molecules and two monoanionic sac ligands while in later, the octahedral sites fulfilled by two neutral bidentate ethylenediamine molecules and two monoanionic sac ligands. Splitting of the crystal field (Δo) and Racah parameter (B) of two sets of complexes [M(sac)2(H2O)4].2H2O and [M(sac)2(en)2].2H2O are estimated from their electronic spectra using Tanabe-Sugano diagram of Co(II) and Ni(II) complexes while Δo values of Fe(II) and Cu(II) derivatives are calculated directly from their absorption maxima. Our experimental results show that for the studied ligands and the divalent transition metal ions, the Δo values vary according to the following order: Cu(II) > Fe(II) > Co(II) > Ni(II).\u0000Dhaka Univ. J. Sci. 71(1): 6-12, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90521822","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}

{"title":"A Simulation Based Comparative Study to Find Efficient Parameter Estimation Methods for Weibull Distribution","authors":"A. Sajib, Sabina Sharmin, Sharmin Akter","doi":"10.3329/dujs.v71i1.65268","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65268","url":null,"abstract":"This paper aims to find efficient methods for estimating the parameters (shape =α , scale = β ) of Weibull distribution in different situations. The maximum likelihood estimation method (MLE), the median rank regression method (MRR), the least square method (LSM) and the weighted least square method (WLSM) are considered for the estimation of the parameters. The root mean square error (RMSE) criterion is used to measure the relative efficiency of the estimators experimentally (Monte Carlo simulation). From the simulation study, it is observed that the MLE produces the lowest RMSE, irrespective of all sample sizes, for decreasing hazard function(α << β ) (α is considerably smaller than β ) and roughly linear hazard function with a positive slope (α >1) . When (α >> β ) the WLSM produces the lowest RMSE for small sample sizes (n ≤ 40) but for large sample sizes it is the MLE, irrespective of all types of hazard functions. When (α ,β →1), the WLSM produces the lowest RMSE for small sample sizes (n ≤ 40) and the MLE for large sample sizes irrespective of all types of hazard functions. This pattern becomes reversed whenα and β have the larger value. Only the MLE gets stuck when the hazard function is parallel to Y − axis (α >> β ) and the WLSM is suitable in such a situation (lowest RMSE) irrespective of all sample sizes. Finally, the utility of simulation results have been illustrated by analyzing two real-life data sets.\u0000Dhaka Univ. J. Sci. 71(1): 17-25, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84618311","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}

{"title":"Optimization of 18F Radioisotope Production with Cyclone 18/9 MeV IBA Cyclotron Installed at NINMAS","authors":"Afm Masum Rabbani, Md Shohag Mia, H. Mehdi, Sanchoy Chandra Biswasarma, Md Ariful Islam, Md. Jashim Uddin, T. Biman, Mohammad Anwar Ul Azim, M. Hossain","doi":"10.3329/dujs.v71i1.65273","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65273","url":null,"abstract":"A cyclotron is a particle accelerator, which employs electromagnetic fields to accelerate charged particles to extremely high speeds and energy. It is used to create radioisotopes for radiopharmaceuticals, which are used to diagnose and treat cancer. Because cyclotron-produced radiopharmaceuticals are exceptionally effective in identifying various cancers. Cyclotrons are fast evolving and will play an increasingly important role in the healthcare industry, particularly in advanced medical imaging techniques like positron emission tomography-computed tomography (PET-CT) and single photon emission computed tomography (SPECT). An 18/9 MeV cyclotron (18 MeV for proton and 9 MeV for deuteron, Model: Cyclone 18/9, IBA) was installed at the National Institute of Nuclear Medicine and Allied Science (NINMAS), Bangladesh Atomic Energy Commission (BAEC). Radioisotopes such as 18F, 11C, 13N, and 15O can be produced with this cyclotron. Solid target option is also available here which can be used for producing 67Ga, 68Ga, 124I, 123I, 111In, 99mTc, 64Cu, and 89Zr radioisotopes. 18F is the radioisotope of choice for many radiopharmaceuticals due to its glucose analogous and half-life of 110 min. We are producing FDG on a regular basis. For a 60-minute bombardment time, a 40 to 50 micro amp beam current is employed to produce 18F with a mass of 2500 to 3500 mCi. Because of the variable production parameters used, the production of 18F varies. Parameters used in the production of 18F radioisotope are limited to physical factors such as target material, target volume, collimator, stripper foil, and ion source. As a result, we consider 18F yield to be the most important aspect in providing sufficient activity since we want to find the best operating point that minimizes both production time and cost. In order to produce an optimal 18F radioisotope production, all parameters such as dee voltage, vacuum label, beam current, irradiation time, amount of enriched 18O water, target pressure, and others are taken into account.\u0000Dhaka Univ. J. Sci. 71(1): 56-59, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"165 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86747783","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}

{"title":"Application of Autoregressive Distributed Lag Model to Assess the Environmental Sustainability in Bangladesh","authors":"S. Akhter, Murshida Khanam","doi":"10.3329/dujs.v71i1.65274","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65274","url":null,"abstract":"This research inspects the associations among several macroeconomic factors in Bangladesh using yearly time series data from 1971 to 2019. It also aimed to determine if the environmental Kuznets curve (EKC) hypothesis exists in Bangladesh or not. The findings from the stationarity tests reveal that all variables are ordered I (1) integrated. The ARDL model has been used to explore the longrun and short-run connections between variables in the model. In the long term, the projected findings established the existence of the Kuznets curve hypothesis in the GDP-energy nexus. According to the study, there is a U-shaped association between economic expansion and greenhouse gas emissions. Food production and energy consumption increase emissions, however using biomass does not assist the country to attain sustainability, as an increase in biomass increases greenhouse gas emissions by 1.12%. As a result, our government should explore additional renewable energy sources to restrict emissions and take the required actions in all areas to achieve environmental sustainability.\u0000Dhaka Univ. J. Sci. 71(1): 60-68, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87065999","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}

{"title":"Analyzing Overdispersed Skilled Antenatal Care Visits of Pregnant Women in Bangladesh Using Generalized Poisson Regression Model","authors":"Md Muddasir Hossain Akib, B. Pal","doi":"10.3329/dujs.v71i1.65275","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65275","url":null,"abstract":"It is common to use the Poisson regression model (PRM) for analyzing the count data. The major limitation of this PRM is that the mean and variance of the response variable need to be equal. However, in the actual dataset, the response variable’s variance may exceed the mean, introducing overdispersion in the dataset. In this paper, the generalized Poisson regression model (GPRM) has been used in the modeling and analysis of the skilled antenatal care (ANC) count data extracted from the Bangladesh Demographic and Health Survey (BDHS) 2017-18. The findings of this study have revealed several socioeconomic and demographic variables that significantly impact the skilled ANC visits.\u0000Dhaka Univ. J. Sci. 71(1): 69-75, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"131 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75826128","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}

{"title":"Resistance to Sulphate and Acid Attack of Rice Husk Ash and Fly Ash Based Composite Cement","authors":"Md Ershad Halim, Kazi Nasrin Farooque, Mohammed Mahmudul Hasan, Md. Hasanur Rahman, Uzzal Shaha, F. Ferdousi, Umme Sarmeen Akhtar, M. Ismail, M. Akramuzzaman","doi":"10.3329/dujs.v71i1.65272","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65272","url":null,"abstract":"The current exploration work contains the preparation and examination of the properties of cement-based composite materials. Two kinds of composite materials specifically, Rice Husk Ash Composite Cement and Fly Ash Composite Cement were examined. Rice Husk Ash Composite Cement and Fly Ash Composite Cement was treated with Na2SO4 and HCl solution to check the resistance towards sulphate and acid attack respectively. Sulfate attack has been resolved in this work by estimating weight loss/gain of Ordinary Portland Cement (OPC) and the Composite Cements created from FA and RHA when plunged into 0.5 M and 0.75 M Na2SO4 solution. A loss in weight has been seen at the underlying stage i.e. Following 7 and 14 days when OPC is immersed in sulfate media, however, in the long run there was gain in weight of the composite made with OPC. The loss of weight occurred when the entire test sample is treated with 1.0 M HCl. Results on acid resistance and sulphate attack revealed that Composite cements are better acid resistant but more susceptible to sulphate attack. It was also observed that FAC composite is more susceptible to sulphate attack than RHAC composite. The Ca(OH)2 leaching tests indicate that Composite Cements are effective in reducing the amount of Ca(OH)2 leaching compared to pristine OPC.\u0000Dhaka Univ. J. Sci. 71(1): 49-55, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74988979","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}

{"title":"Caesarean Delivery- a Pressured Choice for Women: A Meta-Analysis of 23 Cross-Sectional Studies","authors":"Munira Nargis Ananna, M. B. Hossain","doi":"10.3329/dujs.v71i1.65265","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65265","url":null,"abstract":"The aim of this study is to investigate the associated factors which influence women to choose caesarean delivery or C-Section (CS) and to quantify the contribution of these factors. This meta-analysis indicates that for maternal age at birth, age group 20-29 years is 1.45 times more likely to choose CS as compared to the age group ≤19 years [OR= 1.45; Overall effect Z=4.57, p<0.01], for mother’s education level educated mothers are 8.86 times more likely to choose CS as compared to the uneducated mothers[OR= 8.86; Z=4.10, p<0.01].For marital status OR=1.40;Z= 1.34, p=0.18, for residence OR= 1.02;Z=0.11, p= 0.91, for mother’s employment status OR= 0.97;Z=-0.12, p= 0.90 and for receiving Antenatal Care between 1-3 times versus 0 time OR= 2.11;Z=1.84, p= 0.07. Mother’s economic status [OR= 1.41;Z=3.43, p<0.01], whether previous CS [OR=9.39; Z=2.24,p=0.03] and type of delivery facility [OR= 0.67; Z=-2.03, p= 0.04] are found to be significant factors for choosing CS over normal delivery.\u0000Dhaka Univ. J. Sci. 71(1): 1-5, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88358016","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}