Dhaka University Journal of Science

Availability of Adequately Iodized Salt Consumption and its Association with Socio-Economic Factors in Bangladesh

2022-11-01T08:04:13+00:00

For normal physiologic functions, Iodine is necessary in small amount. It sanctions the thyroid gland to creates thyroid hormones, which is essential for mature and enlargement of the brain, body structures and central nervous system (CNS). In developing countries mental impediment and insufficient commercial performance are one of the results of iodine insufficiency issue. Globally, universal salt iodization has been executed to eradicate iodine insufficiency. However, the sufficiency of iodine in salts needs close observing to match its deliberated target. From this study,we find the adequately iodized salt consumption is associated with some demographic features such as, education, region, wealth index, access to mass-media etc. These findings are important for policy makers and Government as they should take necessary steps to increase the accession to education and media and also take realistic plan to increase the availability of adequately salt in Bangladesh.

Dhaka Univ. J. Sci. 70(2): 1-7, 2022 (July)

Impact of Migration on the Utilization of Antenatal Care Services among Women of Urban Slums in Bangladesh

2022-11-01T08:04:15+00:00

Mothers living in urban slums in Bangladesh get far less access to maternal and child health care services which may lead to mortality or serious morbidity to mothers as well as newborns. Lack of antennal care (ANC) is closely linked to poor pregnancy outcomes including low birth weight, preterm births or infant mortality. However, exposure to migration makes the situation worse in terms of attending urban community health care facilities among women in slums. Since the effect of migration on the usage of antenatal care services in slums has remained an under studied area, this paper aims to examine the adjusted effect of migration on perceiving adequate ANC. Data from the second round of Bangladesh Urban Health Survey conducted in 2013 have been used for this study. A well fitted binary logistic model resulted in lower odds of receiving complete ANC among recently migrated women in slums (AOR=0.602, 95% CI=0.43-0.85). Therefore, further emphasis should be given to increase awareness about antenatal care services among women who are recently migrated to urban slums in Bangladesh.

Dhaka Univ. J. Sci. 70(2): 8-14, 2022 (July)

A Variant of the RSA Cryptosystem with Smaller Keys

2022-11-01T08:04:17+00:00

In this paper we introduce an efficient variant of the RSA cryptosystem which will need lesser memory for key storage which is lessen the computational cost. Introduction of the RSA cryptosystem by Rivest, Shamir, and Adleman in 1978 was a revolutionary step in cryptography. The regular RSA system needs huge cost for decryption due to large size of the private decryption key. The proposed variant will be a solution to this conundrum.

Dhaka Univ. J. Sci. 70(2): 15-17, 2022 (July)

Conformal Killing Vector Fields of Riemannian Manifolds

2022-11-01T08:04:18+00:00

The main aim of this article to study about vector fields of manifold and how these vector fields will be Killing and Conformal Killing vector fields. Conformal transformation of Weyl rescaling which is conformally related to metrices from g to g, Levi-Civita connection Δ , Lie derivative, torsion with tensor concept of manifold N in a multi-linear map have been treated in this paper. Finally, we have been proved Example 3.02and established the theorem 6.02 on Conformal Killing vector fields.

Dhaka Univ. J. Sci. 70(2): 18-22, 2022 (July)

Integrated Study of CO2 Sequestration and CO2-EOR in Oil Reservoir by Compositional Simulation

2022-11-01T08:04:19+00:00

Now researchers are performing extensive research work to increase the oil and gas production to meet increasing energy demand and to reduce the CO2concentration from atmosphere to reduce global worming.This study is an effort to increase oil production by CO2-EOR from an oil reservoir in Surma basin and to evaluate the oil reservoir as a candidate of CO2 sequestration. The oil reservoir rock is Bhuban sandstone and fluid is heavy oil. High salinity water is also present in the oil reservoir. A compositional reservoir simulation model has been developed for this study. Geo-cellular 3D reservoir grid structure has been constructed by block centered geometry. Reservoir rock properties such as porosity, absolute permeability and net to gross ratio have been modeled using rock properties of Bhuban sandstone. Reservoir oil composition has been determined from liquid chromatograph. Thermodynamic properties of pure components in reservoir oil have been included in the compositional reservoir simulation model. The reservoir has been developed by four CO2 injection wells arranged at the periphery of the reservoir and one oil production well kept at the center of the reservoir. The optimum CO2 injection rate is 500 MSCF/D at pressure 3100 psi by a single well and optimum oil production rate is 4900 STB/D.

Dhaka Univ. J. Sci. 70(2): 23-28, 2022 (July)

Production, Characterization and Evaluation of Pyrolysis Oil from Tyre Wastes Available in Bangladesh

2022-11-01T08:04:21+00:00

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.

Dhaka Univ. J. Sci. 70(2): 29-34, 2022 (July)

Estimation and Health Risk Assessment of Respirable Silica in the Ambient Particulate Matter of Dhaka City

2022-11-01T08:04:22+00:00

A simple, rapid, and efficient spectrophotometric method was developed for the quantification of respirable crystalline silica (SiO2) in atmospheric particulate matter (PM). The PM samples were collected for 24 hours from two different locations at the University of Dhaka (Mukarram Hussain Khundker Building-MHK and Teacher Student Centre-TSC) using a low-volume air sampler from September to December 2021. The extraction of PM loaded filters followed by filtration resulted in a clear solution. Using UV-visible spectroscopy, the concentration of silica in the filtrate was evaluated by treating the filtrate with molybdate-3 reagent and an amino acid suspension. The average PM-bound silica concentrations at MHK and TSC were 7.72 and 33.86 μgm-3 respectively. Compared to MHK, the silica content in the ambient atmosphere of TSC was four times higher, owing to extensive metro-rail construction work at TSC. The contribution of silica to PM was 3.47% (Site 1) and 5.15% (Site 2). The Hazard Quotient (HQ) was used to characterize the non-cancer risk posed by respirable silica. TSC recorded a high value of 12.87 for the hazard quotient of respirable silica compared to 2.57 for MHK indicating that the exposed inhabitants may have adverse noncancer health impacts. Carcinogenic risk assessment of silica showed that 1 in 341 individuals at MHK and 1 in 78 individuals at TSC could get cancer in their lifetime. This is the first study that demonstrated the high level of PM-bound respirable silica severely degraded air quality as well as potential human health in Dhaka.

Dhaka Univ. J. Sci. 70(2): 35-41, 2022 (July)

Forecasting the Growth Rate of GDP and its Indicators Remittance and Labor Force Participation of Bangladesh using VECM and ARIMA Models

2022-11-01T08:04:24+00:00

The present study used VECM model and ARIMA model for modeling the growth rate of GDP, Remittances and total Labor Force Participation. All of the data of this study are collected from the World Bank Database with indicators as the time series variable from 1999 to 2020. The stationarity of the time series variables has been tested by the Augmented Dickey-Fuller test and investigated that they become stationary at first difference. The lag selection criteria has been applied to find out the no. of lags needed to be included in the model. Lag 2 has been selected for this study. VEC model has been applied in the time series data. Also the ARIMA model imposed on these time series variables. These two models have been used for forecasting. Among the predictions obtained by these two models the better one has been selected by using RMSE, MAPE and MAE. It has been found that for growth rate of GDP and total Labor Force Participation, the ARIMA model is more preferable but for Remittance, VECM is desirable. It has been found that the Remittance and Labor Force have significant positive impact on the growth of GDP. Also, a long run relationship has been found among the growth rate of GDP, Remittances and total Labor Force Participation.

Dhaka Univ. J. Sci. 70(2): 42-47, 2022 (July)

Assessment of Nutritional Value of Limonia acidissima L. (Wood Apple)

2022-11-01T08:04:25+00:00

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.

Dhaka Univ. J. Sci. 70(2): 48-52, 2022 (July)

Analysis of Fats and Fatty Acids in Several Bakery Cookies of Bangladesh

2022-11-01T08:04:28+00:00

Cookie is one of the most common baked goods consumed by people throughout the globe including in Bangladesh. Cookies have a considerable amount of fats, despite not being considered as fatty foods by consumers. Since cookies are eaten by individuals of all ages and socioeconomic groups, an experimental investigation was conducted to evaluate the quality and quantity of the fat fraction of bakery cookies available in Dhaka. Ten different bakery cookies (5 savory and 5 sweet) from five different manufacturers were collected from several local supermarkets of Dhaka and analyzed to study the total fat contents, relative fatty acids compositions, moisture and ash contents. Extraction of fat from cookie samples was done using n-hexane. The fatty acid compositions of the samples were determined by gas-liquid chromatograph equipped with flame ionization detector. The results showed the total fat content to be ranged from 16.13-26.84 g/100g of cookies. The fatty acid composition exhibited that the relative percentage of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) were in the range of 7.76-78.20, 9.66-79.56 and 0.38-9.64%, respectively. The major FAs were found to be palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid (C18:1) and linoleic acid (C18:2). The moisture and ash contents in the samples were found in the range of 0.79-4.80 and 0.73-4.23%, respectively.

Dhaka Univ. J. Sci. 70(2): 53-58, 2022 (July)

Jute Fiber Reinforced Hydrogel Composite for Removal of Methylene Blue Dye from Water

2022-11-01T08:04:30+00:00

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.

Dhaka Univ. J. Sci. 70(2): 59-64, 2022 (July)