Pub Date : 2022-07-24DOI: 10.3329/dujs.v70i1.60381
M. Shoeb, F. Sharmin, Md. Nazrul Islam, L. Nahar, Rafiza Islam, N. Parvin
Bangladesh has a vast natural water resources. In order to determine the water quality parameters such as pH, EC, DO, BOD, TOC, ionsi.e., NO3-, SO42-, PO43- and heavy metals, thirty surface water samples were collected from the southern part of Bangladesh includingthe coastal regions of Patuakhali district and Kuakata sea beach area during the dry season. The pH of water samples was ranged from7.58 to 8.77 with an average of 8.15. The average conductivity value was 8.83±2 mS/cm. The average DO was 8.33±1.82 mg/L andBOD was 0.31±0.03 mg/L. TOC was found between 0.78 and 1.78 mg/L with an average of 1.24 mg/L. The concentration of NO3-,SO42-, PO43- was determined by ion chromatography and only sulphate ion was detected in a very low concentration. Water samplesfrom different sources were analysed for five metals by AAS and the concentrations of Pb, Cd, Mn, Hg and As were below 0.2, 0.01,0.22, 0.001 and 0.005 mg/L, respectively. Dhaka Univ. J. Sci. 70(1): 49-57, 2022 (January)
{"title":"Assessment of Physico-Chemical Parameters of Water Samples Collected from the Southern Part of Bangladesh","authors":"M. Shoeb, F. Sharmin, Md. Nazrul Islam, L. Nahar, Rafiza Islam, N. Parvin","doi":"10.3329/dujs.v70i1.60381","DOIUrl":"https://doi.org/10.3329/dujs.v70i1.60381","url":null,"abstract":"Bangladesh has a vast natural water resources. In order to determine the water quality parameters such as pH, EC, DO, BOD, TOC, ionsi.e., NO3-, SO42-, PO43- and heavy metals, thirty surface water samples were collected from the southern part of Bangladesh includingthe coastal regions of Patuakhali district and Kuakata sea beach area during the dry season. The pH of water samples was ranged from7.58 to 8.77 with an average of 8.15. The average conductivity value was 8.83±2 mS/cm. The average DO was 8.33±1.82 mg/L andBOD was 0.31±0.03 mg/L. TOC was found between 0.78 and 1.78 mg/L with an average of 1.24 mg/L. The concentration of NO3-,SO42-, PO43- was determined by ion chromatography and only sulphate ion was detected in a very low concentration. Water samplesfrom different sources were analysed for five metals by AAS and the concentrations of Pb, Cd, Mn, Hg and As were below 0.2, 0.01,0.22, 0.001 and 0.005 mg/L, respectively.\u0000Dhaka Univ. J. Sci. 70(1): 49-57, 2022 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"15 12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86959966","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}
Pub Date : 2022-07-24DOI: 10.3329/dujs.v70i1.60382
Md Reazul Alam Refat, M. Shoeb, A. Sultana
The seeds of winter (wax gourd), long (bottle gourd) and large (pumpkin) melon were analyzed for nutritional parameters mainlyprotein, fat/oil, carbohydrate, dietary fiber, protein, minerals and moisture and fatty acids composition. The double beam ultravioletvisible spectrophotometer was used for analysis of total sugar. The protein content was determined using the Kjeldahl method. An atomic absorption spectrophotometer was used to quantify minerals (Fe, Cu, and Zn). Fatty acid was analyzed by gas chromatography(GC) equipped with a flame ionization detector (FID). From the proximate analysis, it was found that the winter melon (wax gourd)seeds contain protein, oil, carbohydrate, soluble dietary fiber, moisture and ash content of 19.71, 16.46, 56.48, 3.10, 68.88 and 4.26%, respectively. Similarly, long melon (bottle gourd) was found to contain 16.12, 13.61, 46.88, 2.2, 76.45 and 5.2% of protein, oil,carbohydrate, soluble dietary fiber, moisture and ash, respectively. The contents of protein, oil, carbohydrate, soluble dietary fiber,moisture and ash in large melon (pumpkin) seeds were found to be 29.64, 18.17, 55.32, 1.3, 79.53 and 5.12%, respectively. In mineralanalysis, iron, copper, and zinc contents were found to be 6.75, 0.62, and 6.10 mg/100g in winter melon; 7.8, 1.63, and 4.25 mg/100gin long melon; and 13.95, 1.15, and 5.11 mg/100g in large melon, respectively. Dhaka Univ. J. Sci. 70(1): 58-63, 2022 (January)
{"title":"Proximate Analysis of Melon Seeds Available in Bangladesh","authors":"Md Reazul Alam Refat, M. Shoeb, A. Sultana","doi":"10.3329/dujs.v70i1.60382","DOIUrl":"https://doi.org/10.3329/dujs.v70i1.60382","url":null,"abstract":"The seeds of winter (wax gourd), long (bottle gourd) and large (pumpkin) melon were analyzed for nutritional parameters mainlyprotein, fat/oil, carbohydrate, dietary fiber, protein, minerals and moisture and fatty acids composition. The double beam ultravioletvisible spectrophotometer was used for analysis of total sugar. The protein content was determined using the Kjeldahl method. An atomic absorption spectrophotometer was used to quantify minerals (Fe, Cu, and Zn). Fatty acid was analyzed by gas chromatography(GC) equipped with a flame ionization detector (FID). From the proximate analysis, it was found that the winter melon (wax gourd)seeds contain protein, oil, carbohydrate, soluble dietary fiber, moisture and ash content of 19.71, 16.46, 56.48, 3.10, 68.88 and 4.26%, respectively. Similarly, long melon (bottle gourd) was found to contain 16.12, 13.61, 46.88, 2.2, 76.45 and 5.2% of protein, oil,carbohydrate, soluble dietary fiber, moisture and ash, respectively. The contents of protein, oil, carbohydrate, soluble dietary fiber,moisture and ash in large melon (pumpkin) seeds were found to be 29.64, 18.17, 55.32, 1.3, 79.53 and 5.12%, respectively. In mineralanalysis, iron, copper, and zinc contents were found to be 6.75, 0.62, and 6.10 mg/100g in winter melon; 7.8, 1.63, and 4.25 mg/100gin long melon; and 13.95, 1.15, and 5.11 mg/100g in large melon, respectively.\u0000Dhaka Univ. J. Sci. 70(1): 58-63, 2022 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"2008 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86219947","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}
Pub Date : 2022-07-24DOI: 10.3329/dujs.v70i1.60380
Md Reazul Alam Refat, Polash Nandi, M. Shoeb, A. Sultana
The commercial energy drink samples of 10 different brands were analyzed to study the level of alcohol (if any), sodium benzoate,caffeine, vitamin B, and carbohydrates content. Samples were degassed by ultrasonicator, and CO2 was found to be in a range of 1.27± 0.05 to 4.10 ± 0.10 mL per 100 mL sample. The amount of caffeine, sodium benzoate, glucose, and vitamin B were studied by aUV-Visible spectrophotometer. The wavelength of absorption maxima was 224, 272, 489, 445, and 292 nm, respectively, for sodiumbenzoate, caffeine, glucose, vitamin B2, and vitamin B6. The correlation coefficients of the calibration curves were found to be0.998, 0.992, 0.998, 0.997, and 0.989 for caffeine, glucose, sodium benzoate, vitamin B2 and vitamin B6, respectively. The alcoholcontent was studied by gas chromatography equipped with a flame ionization detector. Ethanol was not found to be present in anysample. The caffeine and sodium benzoate content in different samples was found in the range of 147.84 ± 0.53 to 846.78 ± 2.64 and52.92 ± 6.23 to 1575.37 ± 4.99 μg/mL, respectively. The sugar content in different samples was found to be 16.16 ± 4.25 to 338.33± 0.75 mg/mL. Vitamin B2 was found to be 13.21± 0.08 and 1.04 ± 0.002 μg/mL, respectively in Bacchus and Wild Brew samplesand Vitamin B6 was found to be 261.17 ± 8.38 and 115.88 ± 0.31 μg/mL in Red Bull and Bacchus samples, respectively. The pH ofthe samples was found to be in the range of 2.79 ± 0.04 to 4.88 ± 0.04. Dhaka Univ. J. Sci. 70(1): 42-48, 2022 (January)
{"title":"Composition of Energy Drink Samples in Bangladesh","authors":"Md Reazul Alam Refat, Polash Nandi, M. Shoeb, A. Sultana","doi":"10.3329/dujs.v70i1.60380","DOIUrl":"https://doi.org/10.3329/dujs.v70i1.60380","url":null,"abstract":"The commercial energy drink samples of 10 different brands were analyzed to study the level of alcohol (if any), sodium benzoate,caffeine, vitamin B, and carbohydrates content. Samples were degassed by ultrasonicator, and CO2 was found to be in a range of 1.27± 0.05 to 4.10 ± 0.10 mL per 100 mL sample. The amount of caffeine, sodium benzoate, glucose, and vitamin B were studied by aUV-Visible spectrophotometer. The wavelength of absorption maxima was 224, 272, 489, 445, and 292 nm, respectively, for sodiumbenzoate, caffeine, glucose, vitamin B2, and vitamin B6. The correlation coefficients of the calibration curves were found to be0.998, 0.992, 0.998, 0.997, and 0.989 for caffeine, glucose, sodium benzoate, vitamin B2 and vitamin B6, respectively. The alcoholcontent was studied by gas chromatography equipped with a flame ionization detector. Ethanol was not found to be present in anysample. The caffeine and sodium benzoate content in different samples was found in the range of 147.84 ± 0.53 to 846.78 ± 2.64 and52.92 ± 6.23 to 1575.37 ± 4.99 μg/mL, respectively. The sugar content in different samples was found to be 16.16 ± 4.25 to 338.33± 0.75 mg/mL. Vitamin B2 was found to be 13.21± 0.08 and 1.04 ± 0.002 μg/mL, respectively in Bacchus and Wild Brew samplesand Vitamin B6 was found to be 261.17 ± 8.38 and 115.88 ± 0.31 μg/mL in Red Bull and Bacchus samples, respectively. The pH ofthe samples was found to be in the range of 2.79 ± 0.04 to 4.88 ± 0.04.\u0000Dhaka Univ. J. Sci. 70(1): 42-48, 2022 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"143 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79635327","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}
Pub Date : 2022-07-24DOI: 10.3329/dujs.v70i1.60378
Sumaia Abdullah, M. Rahman, A. Shaikh, P. K. Bakshi
Mixed ligand binuclear complexes of Cu(II) and Cd(II) with adenine (Ade) and 1,4-diazabicyclo[2.2.2]octane (DABCO) havebeen synthesized at a metal to ligands (M:L:L′) molar ratio of 1:1:1 in aqueous medium under ambient conditions. All synthesizedcomplexes are powdery solids of different colours, slightly soluble in hot water and decompose at high temperature. Characterizationof the complexes was accomplished using various analytical techniques, e.g. metal and chloride content analysis, Fourier transformspectrophotometer (FT-IR), UV-visible spectrophotometer, magnetic measurement, and thermal analyses. The metal and chloridecontents analyses of the complexes reveal to their stoichiometry [M2Cl2(Ade)2(H2O)2(DABCO)]Cl2 [M = Cu(II) or Cd(II)]. Analyticaldata suggests that they are homo metal symmetric binuclear complexes comprises of two [MCl(Ade)(H2O)] moieties in betweena DABCO molecule is N,N′-bridge bonded. The arrangements of the ligands around the metal centers are essentially tetrahedralinvolving N(9) of deprotonated imidazole moiety, one Cl- ion, one oxygen from the water molecule and one tertiary N atom fromDABCO completing the coordination. Proton migration occurs from N(9) to the N(1) site resulting into a zwitterionic form ofadenine, additionally N(3) site of which is hydrogen bonded with the coordinated water molecule. Electrochemical redox behaviourof Cu(II) in presence of adenine and DABCO in the aqueous medium was also studied. It exhibits quasi-reversible one-electrontransfer processes. Dhaka Univ. J. Sci. 70(1): 28-33, 2022 (January)
{"title":"Mixed Ligand Binuclear Complexes of Copper(II) and Cadmium(II) with Adenine and 1,4-Diazabicyclo[2.2.2]octane","authors":"Sumaia Abdullah, M. Rahman, A. Shaikh, P. K. Bakshi","doi":"10.3329/dujs.v70i1.60378","DOIUrl":"https://doi.org/10.3329/dujs.v70i1.60378","url":null,"abstract":"Mixed ligand binuclear complexes of Cu(II) and Cd(II) with adenine (Ade) and 1,4-diazabicyclo[2.2.2]octane (DABCO) havebeen synthesized at a metal to ligands (M:L:L′) molar ratio of 1:1:1 in aqueous medium under ambient conditions. All synthesizedcomplexes are powdery solids of different colours, slightly soluble in hot water and decompose at high temperature. Characterizationof the complexes was accomplished using various analytical techniques, e.g. metal and chloride content analysis, Fourier transformspectrophotometer (FT-IR), UV-visible spectrophotometer, magnetic measurement, and thermal analyses. The metal and chloridecontents analyses of the complexes reveal to their stoichiometry [M2Cl2(Ade)2(H2O)2(DABCO)]Cl2 [M = Cu(II) or Cd(II)]. Analyticaldata suggests that they are homo metal symmetric binuclear complexes comprises of two [MCl(Ade)(H2O)] moieties in betweena DABCO molecule is N,N′-bridge bonded. The arrangements of the ligands around the metal centers are essentially tetrahedralinvolving N(9) of deprotonated imidazole moiety, one Cl- ion, one oxygen from the water molecule and one tertiary N atom fromDABCO completing the coordination. Proton migration occurs from N(9) to the N(1) site resulting into a zwitterionic form ofadenine, additionally N(3) site of which is hydrogen bonded with the coordinated water molecule. Electrochemical redox behaviourof Cu(II) in presence of adenine and DABCO in the aqueous medium was also studied. It exhibits quasi-reversible one-electrontransfer processes. \u0000Dhaka Univ. J. Sci. 70(1): 28-33, 2022 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79956069","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}
Pub Date : 2022-07-24DOI: 10.3329/dujs.v70i1.60384
Sahadat Jaman, Md. Jafrul Islam, A. Imran, M. Kamruzzaman, M. Mallik, Pappu Paul, Imroj Syed
Heat waves (HWs) are an extreme temperature condition that has a direct impact on human lives. In recent years, a large number ofpeople have died all over the world due to hot weather. The purpose of this study is to predict HWs accurately to mitigate the casualtiescaused by them. Two HW events are selected for this study (Event-1: 0000 UTC of 18 May to 0000 UTC of 25 May 2015, Event-2:0000 UTC of 05 April to 2100 UTC of 08 April 2015). At first, sensitivity tests have been done using different combinations ofphysics schemes. Sensitivity of Planetary boundary layer (PBL) and surface layer (SL) schemes combinations (YSU-Revised MM5,YSU-MM5, MYJ-Eta, and ACM2-Revised MM5) and land surface models (RUC, Noah, Noah-MP, and CLM4) are investigated topredict Comfort Index (CI), which is identified by using Physiological Equivalent Temperature (PET). To simulate PET, the primarymeteorological variables 2-m air temperature (T2), 2-m relative humidity (rh2), mean radiant temperature (TMRT), wind speed at 10m (ws10), and cloud cover data have been used. These parameters were simulated by the WRF model using both single and nesteddomains. The experiments found that the combination of the YSU-MM5 scheme and the Noah land surface model predicted theWRF simulated variables very well. The study also found that the CI exists between the slight heat stress to extreme heat stress andthe maximum PET values were found to be 47.6 ºC and 48.5 ºC for Rajshahi and Khulna event respectively. Dhaka Univ. J. Sci. 70(1): 70-78, 2022 (January)
{"title":"Sensitivity of Different Physics Schemes in the Simulation of Heat Wave Events over Bangladesh Using WRF-ARW Model","authors":"Sahadat Jaman, Md. Jafrul Islam, A. Imran, M. Kamruzzaman, M. Mallik, Pappu Paul, Imroj Syed","doi":"10.3329/dujs.v70i1.60384","DOIUrl":"https://doi.org/10.3329/dujs.v70i1.60384","url":null,"abstract":"Heat waves (HWs) are an extreme temperature condition that has a direct impact on human lives. In recent years, a large number ofpeople have died all over the world due to hot weather. The purpose of this study is to predict HWs accurately to mitigate the casualtiescaused by them. Two HW events are selected for this study (Event-1: 0000 UTC of 18 May to 0000 UTC of 25 May 2015, Event-2:0000 UTC of 05 April to 2100 UTC of 08 April 2015). At first, sensitivity tests have been done using different combinations ofphysics schemes. Sensitivity of Planetary boundary layer (PBL) and surface layer (SL) schemes combinations (YSU-Revised MM5,YSU-MM5, MYJ-Eta, and ACM2-Revised MM5) and land surface models (RUC, Noah, Noah-MP, and CLM4) are investigated topredict Comfort Index (CI), which is identified by using Physiological Equivalent Temperature (PET). To simulate PET, the primarymeteorological variables 2-m air temperature (T2), 2-m relative humidity (rh2), mean radiant temperature (TMRT), wind speed at 10m (ws10), and cloud cover data have been used. These parameters were simulated by the WRF model using both single and nesteddomains. The experiments found that the combination of the YSU-MM5 scheme and the Noah land surface model predicted theWRF simulated variables very well. The study also found that the CI exists between the slight heat stress to extreme heat stress andthe maximum PET values were found to be 47.6 ºC and 48.5 ºC for Rajshahi and Khulna event respectively. \u0000Dhaka Univ. J. Sci. 70(1): 70-78, 2022 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83816435","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}
Pub Date : 2022-07-24DOI: 10.3329/dujs.v70i1.60376
Gaylan Peyari Tarannum Dana, Sawkia Afroz
The rapid rise of diabetes, cardiovascular disease (CVD) and chronic respiratory disease (CRD) are causing serious challenges forBangladesh to achieve the sustainable development goal (SDG) target 3.4 by 2030. The study aims to describe the state of healthcarefacilities to provide diagnosis and treatment for diabetes, CVD and CRD related services in Bangladesh. This cross-sectional studyused data from 2017 Bangladesh Health Facility Survey (BHFS). A total of 406 health facilities providing all three services wereconsidered for this study. Findings of the study illustrated that there were rural-urban disparities in healthcare facilities to providediabetics, CVD, CRD related services. Diabetics and CRD related services were significantly higher in public healthcare facilitiesof urban areas compared to rural areas (P <0.008 and P<0.001, respectively). Also, public health facilities of urban areas were morelikely to provide CVD related services compared to rural areas. While private healthcare facilities of urban areas were more likelyto provide CVD, CRD related services than rural areas. Private healthcare facilities of rural areas were in better condition to providediabetes related services than urban areas. However, the country is yet to attain optimal progress in the overall status of health sector.Therefore, in order to cope up with the rising burden of diabetes, CVD and CRD and to minimize the burden of disease specific outofpocket healthcare expenses, recommendations include strengthening and improving stewardship, improving quality of servicesand improving monitoring as well as supervision of decentralized healthcare facilities. Dhaka Univ. J. Sci. 70(1): 14-21, 2022 (January)
{"title":"The State of Healthcare Facilities to Provide Diabetes, Cardiovascular and Chronic Respiratory Disease Related Services in Bangladesh","authors":"Gaylan Peyari Tarannum Dana, Sawkia Afroz","doi":"10.3329/dujs.v70i1.60376","DOIUrl":"https://doi.org/10.3329/dujs.v70i1.60376","url":null,"abstract":"The rapid rise of diabetes, cardiovascular disease (CVD) and chronic respiratory disease (CRD) are causing serious challenges forBangladesh to achieve the sustainable development goal (SDG) target 3.4 by 2030. The study aims to describe the state of healthcarefacilities to provide diagnosis and treatment for diabetes, CVD and CRD related services in Bangladesh. This cross-sectional studyused data from 2017 Bangladesh Health Facility Survey (BHFS). A total of 406 health facilities providing all three services wereconsidered for this study. Findings of the study illustrated that there were rural-urban disparities in healthcare facilities to providediabetics, CVD, CRD related services. Diabetics and CRD related services were significantly higher in public healthcare facilitiesof urban areas compared to rural areas (P <0.008 and P<0.001, respectively). Also, public health facilities of urban areas were morelikely to provide CVD related services compared to rural areas. While private healthcare facilities of urban areas were more likelyto provide CVD, CRD related services than rural areas. Private healthcare facilities of rural areas were in better condition to providediabetes related services than urban areas. However, the country is yet to attain optimal progress in the overall status of health sector.Therefore, in order to cope up with the rising burden of diabetes, CVD and CRD and to minimize the burden of disease specific outofpocket healthcare expenses, recommendations include strengthening and improving stewardship, improving quality of servicesand improving monitoring as well as supervision of decentralized healthcare facilities. \u0000Dhaka Univ. J. Sci. 70(1): 14-21, 2022 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89041428","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}
Pub Date : 2022-07-24DOI: 10.3329/dujs.v70i1.60375
Mehedi Hossain, Murshida Khanam, S. Akhter
In this study, an Econometric analysis has been conducted to identify the important factors that affect the food grain productions inBangladesh. Here, we have considered time series data for the years from 1989- 1990 to 2019-2020. Vector Autoregressive (VAR)Model and Autoregressive Integrated Moving Average (ARIMA) model have been considered in this study. Both these modelshave been considered to forecast the productions of food grains in Bangladesh. The forecasting performances of these two modelshave been compared by using RMSE, MAE, and MAPE. It has been found that the VAR model is better than the ARIMA model toforecast the food grain production. On the other hand, it has been come out from the analysis that there is no significant impact ofchemical fertilizer on the food grain production, but irrigation area has significant impact on the food grain production. Among thethree variables: food grain production, irrigation area and chemical fertilizer, there exists short run relationship. Dhaka Univ. J. Sci. 70(1): 8-13, 2022 (January)
{"title":"An Econometric Analysis to Forecast the Food Grain Production in Bangladesh by Using ARIMA and VAR Models","authors":"Mehedi Hossain, Murshida Khanam, S. Akhter","doi":"10.3329/dujs.v70i1.60375","DOIUrl":"https://doi.org/10.3329/dujs.v70i1.60375","url":null,"abstract":"In this study, an Econometric analysis has been conducted to identify the important factors that affect the food grain productions inBangladesh. Here, we have considered time series data for the years from 1989- 1990 to 2019-2020. Vector Autoregressive (VAR)Model and Autoregressive Integrated Moving Average (ARIMA) model have been considered in this study. Both these modelshave been considered to forecast the productions of food grains in Bangladesh. The forecasting performances of these two modelshave been compared by using RMSE, MAE, and MAPE. It has been found that the VAR model is better than the ARIMA model toforecast the food grain production. On the other hand, it has been come out from the analysis that there is no significant impact ofchemical fertilizer on the food grain production, but irrigation area has significant impact on the food grain production. Among thethree variables: food grain production, irrigation area and chemical fertilizer, there exists short run relationship. \u0000Dhaka Univ. J. Sci. 70(1): 8-13, 2022 (January)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89053738","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}
Pub Date : 2022-07-04DOI: 10.3329/dujs.v69i3.60029
G. J. Islam, Shaheda Zannah
Electrochemistry at the interface between two immiscible electrolyte solutions (ITIES) has become an important and powerful platform for the detection and characterization of a wide variety of organic and inorganic species. Liquid/liquid electrochemistry overcomes some limitations faced in conventional solid/liquid electrochemistry. These include employment ofion transfer voltammetry across the ITIES as the basis for detection of non-redoxactive ions. The analytical sensitivity increasedon miniaturisation of the interface with an improvement insensitivity due to the enhanced mass transport via convergent diffusionas the size of the ITIES is minimised. In this review article, the ITIES is briefly described along with the scope of electrochemical research at micro-ITIES. Dhaka Univ. J. Sci. 69(3): 186-193, 2022 (June)
{"title":"Scope of Electrochemistry at Liquid/liquid Micro-Interfaces","authors":"G. J. Islam, Shaheda Zannah","doi":"10.3329/dujs.v69i3.60029","DOIUrl":"https://doi.org/10.3329/dujs.v69i3.60029","url":null,"abstract":"Electrochemistry at the interface between two immiscible electrolyte solutions (ITIES) has become an important and powerful platform for the detection and characterization of a wide variety of organic and inorganic species. Liquid/liquid electrochemistry overcomes some limitations faced in conventional solid/liquid electrochemistry. These include employment ofion transfer voltammetry across the ITIES as the basis for detection of non-redoxactive ions. The analytical sensitivity increasedon miniaturisation of the interface with an improvement insensitivity due to the enhanced mass transport via convergent diffusionas the size of the ITIES is minimised. In this review article, the ITIES is briefly described along with the scope of electrochemical research at micro-ITIES.\u0000Dhaka Univ. J. Sci. 69(3): 186-193, 2022 (June)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83379980","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}
Pub Date : 2022-07-04DOI: 10.3329/dujs.v69i3.60034
N. Hossain, Md. Ismail Hossain, P. Ahamed, M. A. Yousuf
An effective method of water and carbon tetrachloride (CCl4) system has been studied to recover metals ions from spent Li-ion battery cathode materials. Leaching of HCl and HCl + H2O2 has been applied individually to dissolve the collected cathode materials. Metal ions dissolved in HCl and HCl + H2O2 has been treated separately with a solution of hexadecyl amine in CCl4. The formation of metal ions-hexadecyl amine complex has been confirmed from UV-visible spectroscopy. Recovery of metals from the produced complex has been carried out via filtration and calcination. The calcined materials has been characterized using Fourier transform infrared spectroscopy (FT-IR),field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) andpowder x-ray diffraction (XRD). Dhaka Univ. J. Sci. 69(3): 225-229, 2022 (June)
{"title":"Binary Solvent System for Extraction of Cathode Material From Spent Li-ion Batteries","authors":"N. Hossain, Md. Ismail Hossain, P. Ahamed, M. A. Yousuf","doi":"10.3329/dujs.v69i3.60034","DOIUrl":"https://doi.org/10.3329/dujs.v69i3.60034","url":null,"abstract":"An effective method of water and carbon tetrachloride (CCl4) system has been studied to recover metals ions from spent Li-ion battery cathode materials. Leaching of HCl and HCl + H2O2 has been applied individually to dissolve the collected cathode materials. Metal ions dissolved in HCl and HCl + H2O2 has been treated separately with a solution of hexadecyl amine in CCl4. The formation of metal ions-hexadecyl amine complex has been confirmed from UV-visible spectroscopy. Recovery of metals from the produced complex has been carried out via filtration and calcination. The calcined materials has been characterized using Fourier transform infrared spectroscopy (FT-IR),field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) andpowder x-ray diffraction (XRD).\u0000Dhaka Univ. J. Sci. 69(3): 225-229, 2022 (June)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82709314","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}
Pub Date : 2022-07-04DOI: 10.3329/dujs.v69i3.60030
Md. Borhanul Asfia, M. Rashid
Structural, electronic and optical properties of niobium doped ZnS are studied by using full-potential linearized augmented plane wave plus local orbital (FPLAPW+lo) method within the density functional theory (DFT). Computed results of Nb doped ZnS are compared with that of the pristine zinc blende. Tran-Blaha approach of modified Becke and Johnson local spin density approximation (TB-mBJ) is used to study electronic and optical properties. Estimated result shows that Nb reduces the bandgap of ZnS due to hybridization of Nb-4d orbital with S-3p orbital near the Fermi level. Niobium dopant provides half metallic nature to ZnS with 100% spin polarization. Maximum photo-response is noticed in the ultraviolet range for Zn1-xNbxS (x = 25, 12.5, 6.25 %). Highest peaks are shifted toward the lower energy range for higher dopant percentage. All these suggest that Nb doped ZnS solid solutions are suitable candidate for both energy filter of UV spectrum and spintronic device. Dhaka Univ. J. Sci. 69(3): 194-201, 2022 (June)
{"title":"First-Principles Study of Half Metallic Ferromagnetic and Optical Properties of Nb Doped Cubic ZnS using TB-mBJ Approximation","authors":"Md. Borhanul Asfia, M. Rashid","doi":"10.3329/dujs.v69i3.60030","DOIUrl":"https://doi.org/10.3329/dujs.v69i3.60030","url":null,"abstract":"Structural, electronic and optical properties of niobium doped ZnS are studied by using full-potential linearized augmented plane wave plus local orbital (FPLAPW+lo) method within the density functional theory (DFT). Computed results of Nb doped ZnS are compared with that of the pristine zinc blende. Tran-Blaha approach of modified Becke and Johnson local spin density approximation (TB-mBJ) is used to study electronic and optical properties. Estimated result shows that Nb reduces the bandgap of ZnS due to hybridization of Nb-4d orbital with S-3p orbital near the Fermi level. Niobium dopant provides half metallic nature to ZnS with 100% spin polarization. Maximum photo-response is noticed in the ultraviolet range for Zn1-xNbxS (x = 25, 12.5, 6.25 %). Highest peaks are shifted toward the lower energy range for higher dopant percentage. All these suggest that Nb doped ZnS solid solutions are suitable candidate for both energy filter of UV spectrum and spintronic device.\u0000Dhaka Univ. J. Sci. 69(3): 194-201, 2022 (June)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91012767","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}
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