bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical, Magnetic and Adsorptive Properties of Prepared Copper(II) Oxide
Authors: Rahman Md Ataur , Islam Tajmeri SA , Hossain Md Mufazzal 
Published: July 2021

We report the surface morphology, structural propertiesand surface characterization of copper(II) oxide by scanning electron microscope, energy dispersive X-ray spectroscopy, Fourier transformation infrared spectroscopy, attenuated total reflection infrared spectroscopy and X-ray diffraction. All the data of analysis were consistent with each other and bear the evidence for the purity of the prepared oxide. Kubelka-Munk (K-M) theory is used for the determination of direct band gap of the prepared oxide from UV-visible reflectance spectrum. The band gap value of the bulk material was found to be 4.15 0.05 eV from F(R) versus energy and (F(R) hv)n versus energy plots, with n=1/2 and n=2 Molar magnetic susceptibility and effective magnetic moment of the oxide are 3.393×10-4(cgs) and 0.895 BM respectively which suggest that the oxide is paramagnetic. Catalytic activity was investigated by the study of adsorption of brilliant red (BR) on the surface of prepared oxide in aqueous medium at room temperature. Adsorption isotherm shows that BR moleculesare adsorbed layer by layer on the surface of oxide. Study of the adsorption phenomenon in this work suggest that copper(II) oxide has significant adsorptive and catalytic property.
Dhaka Univ. J. Sci. 68(1): 7-12, 2020 (January)
Readiness of Health Facilities to Provide Child Curative Care Services: Evidence Based on Bangladesh Health Facility Survey, 2014
Authors: Sen Kanchan Kumar , Nilima Shahnaz , Khokan Mahfuzur Rahman 
Published: July 2021

Bangladesh is far away to achieve the target of sustainable development goal 3 (SDG 3). To reduce the child mortality, all sectors related to child health should be improved by taking appropriate actions. In this study, readiness of child curative care health facility services is explored. The readiness was not directly measured, it is measured based on the four domains of ten indicators following WHO guidelines. To create readiness index, equal weights are given to each domains of indicators and also to each indicators at each weighted domains for providing child curative care services. The major purpose of the study is to find out the determinants of readiness of health facilities to provide the child curative care services. The 2014 Bangladesh Health Facility Survey (BHFS) data have been used to serve the purpose. The ordinal logistic regression model with proportional odds assumption has been applied in the study. Type of facility, health provider status, division, qualification of health provider and basic amenities in facility are found to have significant effects on readiness index.
Dhaka Univ. J. Sci. 68(1): 29-35, 2020 (January)
A Simulation Based Study for the Early Detection of Glaucoma Using Temperature Profiling of Human Eye
Authors: Ghosh Shajib , Rabbani Mamun , Arefin ASM Shamsul 
Published: July 2021

Glaucoma is one of the leading ophthalmologic disorders worldwide which results in irreversible blindness if left untreated. Although many detection techniques are already in use, they prove to detect glaucoma at a later stage when the disease causes irreversible effects to the optic tissue. This work aims at developing a novel technique to detect the presence and progression of glaucoma at an early stage through temperature profiling of optic tissues by LASER radiation. A 3D CAD model of the real human eye designed in SolidWorksTM was used and different parameter values were defined for performing thermal simulation in COMSOL Multiphysics® for three distinct LASER point sources: 694.3 nm Ruby LASER, 1064 nm Nd:YAG LASER and 1340 nm Nd:YAP LASER. By analyzing the thermal profile obtained from the simulation, an inverse trend of temperature variation with progression of glaucoma was observed. The effect was most prominently observed in using 694.3mm Ruby LASER with no such temperature rise in the eye causing any physiological harm. This work shows the possibility of using temperature profile due to irradiated light on human eye as a novel biomarker for the early detection of glaucoma.
Dhaka Univ. J. Sci. 68(1): 37-44, 2020 (January)
Comparison Between Two Multinomial Overdispersion Models Through Simulation
Authors: Afroz Farzana , Shabuz Zillur Rahman 
Published: July 2021

A key assumption when using the multinomial distribution is that the observations are independent. In many practical situations, the observations could be correlated or clustered and the probabilities within each cluster might vary, which may lead to overdispersion. In this paper we discuss two well-known approaches to model overdispersed multinomial data, the Dirichlet-multinomial model and the finite-mixture model. The difference between these two models has been illustrated via simulation study. The forest pollen data is considered as a practical example of overdisperse multinomial data. The overdispersion parameter,φ, has been estimated using two classical estimators.
Dhaka Univ. J. Sci. 68(1): 45-48, 2020 (January)
Investigation of Meteorological Conditions Favourable for Formation of Thunderstorm Occurred Over Bangladesh Through Simulation by WRF-ARW Model
Authors: Quadir Dewan Abdul , Rashid Towhida , Akhter Shammi , Ahasan MN 
Published: July 2021

Investigation of meteorological conditions favorable for formation of pre-monsoon thunderstorm over Bangladesh has been conducted by simulating a selected thunderstorm case using ARW dynamic core of WRF model (WRF-ARW). A multi-cell thunderstorm formed on 30-03-2018 over the northwestern tip of Bangladesh and adjacent territories of India and moved south-southeast wards with its highest development at 09:30 UTC was selected for this study. The chosen case of thunderstorm has 3 distinct cells of which 2 cells have the width of over 100 km each and the third one located in the eastern Bangladesh and had the width of 50 km. A WRF ARW model has been applied to examine the atmospheic characteristics favorabe for genesis of selected case run in a double nested domain of resolution of 9x9 km2 in the outer domain and 3 3 km2in the inner domain. The analysis of the geopotential height field of 925 hPa level generated by WRF model at different hours of 31 March 2018 clearly indicates favourable condition with pockets of micro lows and their progression towards central to southeastern Bangladesh. The strong winds blowing from Bay of Bengal along an anticyclone over the Bay brings sufficient moisture to the north. The southerly winds meet the easterly and also westerly winds providing strong low level convergence which favors the convective activities forming cumulus cells. The orography of foothills may also enhance the convections. The wind in the upper tropospheric winds attains jet speed over these areas. The distribution of divergence and vorticity in the 925 hPa level shows the evolution of system. The distribution of precipitation shows that the spatial patterns were well captured. Vertical velocity has been plotted along the vertical-horizontal plane oriented in the east-west direction across a high rainfall cell. This shows that the highest development of narrow vertical cell extends up to 100 hPa level. Following the temporal evolution of the system, it is seen that the highest development delayed by around 2 hours. Some mitigation strategies in respect of thunderstorms and associated lighting are also discussed.
Dhaka Univ. J. Sci. 68(1): 71-77, 2020 (January)
Temperature and Substrate Effects on the Structural, Morphological, and Optical Properties of Iron Oxide Thin Films Prepared by Spray Pyrolysis Technique
Authors: Ferdous Zannatul , Ullah Md Samir , Hussain Sabina 
Published: July 2021

Glass and Fluorine doped Tin Oxide (FTO) coated conducting glass substrates have been chosen for the deposition of Iron Oxide thin films prepared by Spray Pyrolysis Technique. The films were grown at different substrate temperatures (3500C, 4000C, and 4500C) and they were annealed at 3000C for 1 hr. Structural, morphological, optical characterizations of the films have been studied by X-ray diffraction, atomic force micrograph,UV spectroscopy methods. From the XRD studies, films on glass substrates are found to be amorphous in nature with α-hematite phase and crystalline on FTO coated conducting glass substrates. AFM analysis indicates that the films grown on glass substrates are rougher than the films on FTO coated conducting glass substrates. It reveals that the FTO coated conducting glass substrates can be a better choice as a substrate. The transmis sion spectra have been measured in the wavelength range 200-1200 nm. The transmittance of the films both on glass and FTO coated conducting glass substrates has been observed to be about 40- 80% in the wavelength range (500-1100) nm. The optical band gap energy values have been found to be in the range 2.10-2.37 eV.
Dhaka Univ. J. Sci. 68(1): 79-85, 2020 (January)
Generalized Quasilikelihood Inference for Zero Inflated Longitudinal Count Data
Authors: Antu Jannatul Ferdous , Sharmin Sabina , Mallick Taslim Sazzad 
Published: July 2021

In this paper, we extend an observation-driven model for time series of zero inflated count data to longitudinal data setup. Basic properties of the models are discussed. For statistical inference of the proposed model, a generalized quasilikelihood (GQL) estimating equation has been derived for the regression parameter. A pharmaceutical data has been reanalyzed using the proposed approach and results are compared. The proposed approach produces similar estimates as given in the earlier work with much smaller standard errors.
Dhaka Univ. J. Sci. 68(1): 95-99, 2020 (January)
Isolation of Secondary Metabolites from Leucas aspera and Investigation of Biological Activity
Authors: Reza Md Selim Aktar , Rahman Md Hasanur , Chowdhury Tofail Ahmad 
Published: July 2021

Leucas aspera plant was subjected to isolation of secondary metabolites and screening of their biological activities. Four compounds, stigmasterol, lupeol, β-sitosterol and menthol, were isolated from methanol extract. Sixteen different micro-organisms were used for investigating antimicrobial activity of the different extracts of L. aspera where noteworthy zone of inhibition was observed against Gram positive B. subtilis and S. aureus, B. megaterium and Gram negative S. paratyphi, S. typhi, V. mimicus, S. dysenteriae and V. cholera. In brine shrimp lethality bioassay, the highest lethality was showed by crude methanol extract having LC50 values of 4.07μg/mL. The total antioxidant capacity of crude methanol fraction was found to be 59.40 mg/g of plant extract which was maximum comparing with other fractions. No significant cytotoxicity was observed on both HeLa and Vero cell at 1mg/mL sample inhibition.
Dhaka Univ. J. Sci. 68(1): 101-104, 2020 (January)
Rejection Sampling Schemes for Simulating from Arbitrary Probability Densities
Authors: Sajib Anamul Haque 
Published: July 2021

Simulating random variates from arbitrary non-normalized probability densities, very often they do not have familiar forms, is an increasingly important requirement in many different fields, especially in Bayesian statistics. Accept-reject algorithm is one of the commonly used methods to simulate random variates from such densities but restriction on choosing proposal density under this framework (heavier tails than the target density) limits its applicability to a larger extent. On the other hand, Markov Chain Monte Carlo (MCMC) method can choose proposal density arbitrary which makes this method applicable to a larger class of target densities5. In addition to MCMC method, a more general widely used method known as ratio-of-uniforms (RoU) which requires only two uniform variates to simulate one variates from such densities. However, no empirical comparison among these methods for simulating random variates from such densities was seen in the literature. In this paper, we limit our study only to MCMC and RoU methods to simulate random variates from such densities. Following the generation of random variates from such densities using these two methods, we compare the performance of these two methods based on quality of the generated samples. Finally, we conclude that RoU method performs better than MCMC method as far as quality of the generated sample (randomness) and computational cost are concerned.
Dhaka Univ. J. Sci. 68(1): 59-64, 2020 (January)
Controlled Release of 2,4-Dichlorophenoxyacetic Acid Herbicide from Acrylamide Grafted Jute Polymer
Authors: Islam Sanjana , Kamruzzaman Md , Ray Swapan Kumar , Rahman AFM Mustafizur 
Published: July 2021

A herbicide, 2,4-dichlorophenoxyacetic acid was attempted to incorporate in a polymeric system with a view to control/slow down its release. Jute fiber has been used as a biodegradable, eco-friendly source of cellulose which served the macromolecular backbone for polymeric matrix. Dual application of polymer supported herbicide has been attempted by choosing acrylamide as grafting monomer which on release can also act as soil-modifier (fertilizer). Jute fiber was delignified with alkali and bleached to pulping and then grafted with acrylamide to form a polymeric network. This pre-formed polymer was then subjected to esterification reaction with 2,4-dichlorophenoxyacetic acid and the product thus obtained was analyzed with Fourier transform infrared spectroscopy, with the help of attenuated total reflectance as a sampling technique followed by determining the water absorbency. From the study, it was also found that xylene was the best choice of solvent for 2,4-dichlorophenoxyacetic acid, as it can keep the product from aqueous solution, as a consequence of which, higher esterification was favored. It is proposed that the above formulation could be opted for control/slower release of 2,4- dichlorophenoxyacetic acid and can also serve the multiple functions of herbicide and fertilizer or soil nutrient.
Dhaka Univ. J. Sci. 68(2): 105-110, 2020 (July)
Effect of Y3+ Substitution on Structural and Magnetic Properties of Ni0.25 Zn0.75YxFe2-xO4
Authors: Akhter Sharmin , Roy Probal , Anwar Armin , Hossain MA , Khan MNI , Sikder SS 
Published: July 2021

The effect of Y3+ doping on the structural and magnetic properties of Ni0.25 Zn0.75YxFe2-xO4 [x= 0.00, 0.02, 0.04, 0.06 and 0.08] was investigated. The specimen was synthesized by conventional solid state reaction method where the sintering temperature was 1150oC for 3 hours. The structure of the specimens was inspected by XRD pattern and SEM micrographs. The XRD patterns delineate the formation of spinel type cubic structure. The lattice parameters, bulk density, X-ray density and porosity were investigated for all the samples. The SEM micrographs shows that the particles of all the composition are within 0.4 – 1.2 μm. M-H curves at room temperature exhibit the ferromagnetic behavior. The effect of Y3+ causes drastically variation on saturation magnetization (Ms), coercivity (Hc) and remanent magnetization (Mr). Moreover, the M-H curves delineate the soft ferromagnetic phenomenon which can be the reason of the acceptance of the specimen in industrial applications.
Dhaka Univ. J. Sci. 68(2): 111-116, 2020 (July)
Impact of Husbands’ Healthcare Decision Making on Women’s Future Intention of Using Contraceptives in Bangladesh
Authors: Khatun Most Sonia , Nabeen AHM Musfiqur Rahman , Husain Md Maidul , Akanda Md Abdus Salam 
Published: July 2021

The use of contraceptive is important for the reduction of maternal mortality, child mortality and to slow down the high population growth rate. The central objective of this study is to examine the association between husbands‟ involvement with healthcare decision making and women‟s future intention of using contraceptives. Bangladesh Demographic and Health Survey (BDHS), 2014 data is used for this purpose. To evaluate the association overall and stratified binary logistic regression models are employed as well as the odds ratios (OR) along with their 95% confidence intervals are specified. The adjusted effect of overall model shows that husband‟s involvement with healthcare decision making is significantly negatively associated (OR=0.82, 95% CI: 0.70, 0.95) with women‟s intention of using contraceptives. The adjusted effects of stratified models also demonstrate that the association is significantly negative among women in rural area, from middle income families, who are Muslim, having more than two living children, having current age 35 to 49, who are unemployed, whose husbands are 1 to 5 years older and secondary educated. These findings can help to address the men‟s role in family planning and to increase the current contraceptive prevalence rate in Bangladesh.
Dhaka Univ. J. Sci. 68(2): 121-127, 2020 (July)
Production and Characterization of Biodiesel from Aphanamixis polystachya Seed Oil
Authors: Ifteqar Sazia , Sultana Rajia , Banik Sujit , Rahman AFM Mustafizur 
Published: July 2021

The present study focuses on the utilization of non-edible Aphanamixis polystachya seed oil as a potential feedstock for the production of biodiesel. The extracted oil from non-edible seed could not be directly exploited for biodiesel production owing to its high free fatty acid (FFA) content of 5.785%, so acid catalyzed esterification was applied to reduce FFA of oil to zero followed by base-catalyzed transesterification to convert esterified product to its mono-esters. Thermogravimetric analysis (TGA) revealed that the mass percentage corresponding to biodiesel under optimum conditions was 74.38%. The conversion of the triglycerides in the oil into biodiesel through transesterification was confirmed using FT-IR spectroscopy. The elemental analysis of the produced biodiesel was studied. The produced biodiesel had properties which were comparable with biodiesel standards and could be utilized as an alternative diesel fuel without any hardware modifications.
Dhaka Univ. J. Sci. 68(2): 129-136, 2020 (July)
Forecasting Rice Production of Bangladesh Using ARIMA and Artificial Neural Network Models
Authors: Sultana Abira , Khanam Murshida 
Published: July 2021

Forecasting behavior of Econometric and Machine Learning models has recently attracted much attention in the research sector. In this study an attempt has been made to compare the forecasting behavior of Autoregressive Integrated Moving Average (ARIMA) and Artificial Neural Network (ANN) using univariate time series data of annual rice production (1972 to 2013) of Bangladesh. Here, suitable ARIMA has been chosen from several selected ARIMA models with the help of AIC and BIC values. A simple ANN model using backpropagation algorithm with appropriate number of nodes or neurons in a single hidden layer, adjustable threshold value and learning rate, has been constructed. Based on the RMSE, MAE and MAPE values, the results showed that the estimated error of ANN is much higher than the estimated error of chosen ARIMA. So, according to this study, it can be said that the ARIMA model is better than ANN model for forecasting the rice production in Bangladesh.
Dhaka Univ. J. Sci. 68(2): 143-147, 2020 (July)
Determinants of Unmet Need for Family Planning in Bangladesh: Analysis of Matched Case-Control Survey Data of Bangladesh
Authors: Khatun Kakoli , Mallick Taslim Sazzad 
Published: July 2021

Unmet need for family planning (FP) is responsible for lowering contraceptive rate which elevate unwanted pregnancy that have adverse effects on maternal and child health. This study uses Bangladesh Demographic Health Survey, 2014 data in order to identify the factors that are associated with unmet need for FP in Bangladesh. Since the survey is observational, a case-control data has been used matched by age and education of the respondents and the analysis was carried out by using a conditional logistic regression. Unmet need for FP was found to be higher in the rural area, among Muslims, among women who were not exposed to media or not member of any NGO, among couples having no sons.
Dhaka Univ. J. Sci. 68(2): 149-153, 2020 (July)
Physicochemical Properties and Pesticide Residues in Okra Fruits (Abelmoschus esculentus L.)
Authors: Nandi Polash , Islam Md Mazharul , Sultana Abida , Shoeb Mohammad 
Published: July 2021

Vegetable acts as major valuable source of nutrients. Among different vegetables, okra was analyzed to study moisture content, ash content, soluble dietary fiber (SDF), total carbohydrates, and micro-minerals, fatty acid compositions and pesticide residues. Fatty acid compositions were studied by gas chromatograph equipped with a flame ionization detector (GC-FID) while, gas chromatograph equipped with electron capture detector GC-ECD was used for analysis of pesticide residues. Total carbohydrate content was determined by ultraviolet-visible spectrophotometer. The amount of soluble dietary fiber was estimated by acid extraction method. Fe, Cu and Zn content were analyzed by atomic absorption spectroscopy (AAS). The relative percentage of fatty acids were found to be palmitic, cis-9-oleic, linoleic, linolenic and arachidic acid in a range of 0.27-1.35, 3.78 - 6.32, 30.67- 38.44, 2.13 - 4.85 and 1.29 -3.17 %, respectively. Residual diazinon, chlorpyrifos, fenvalerate, cypermethrin and quinalphos were not found to be present in any sample. Total carbohydrate, SDF, moisture and ash content in fresh okra fruits were found to be 6.01- 6.09, 3.35 - 3.50, 88.02 - 91.84 and 1.72 - 2.04 %, respectively. The amount of Fe, Cu and Zn was 11.41-11.43, 1.78 -1.85 and 8.56 - 9.05 mg per 100 g sample, respectively.
Dhaka Univ. J. Sci. 68(2): 155-160, 2020 (July)
Phytochemical and Biological Activity Studies of Tinospora crispa Stem
Authors: Rahman Mariam , Rahman Md Hasanur , Chowdhury Tofail Ahmad 
Published: July 2021

Three compounds namely, tinosporol A, 8-methoxy palmatine and callecdysterol C were isolated from the methanol extract of the stem of Tinospora crispa. Biological activities of different partitionates of the parent extract was also evaluated. Antimicrobial screening of different partitionates was carried out against sixteen different microorganisms and only n-hexane fraction exhibited significant zone of inhibition against Staphylococcus aureus (9 mm), Shigella boydii (9 mm), Shigella dysenteriae (9 mm), Candida albicans (10 mm) and Aspergillus niger (10 mm).The crude methanol extract showed the highest general toxicity with LC50 values of 57.14 μg/mL against brine shrimp lethality bioassay.The total antioxidant capacity of aqueous fraction was found to be 61.61 mg as ascorbic acid equivalentper gram of plant extract.The antioxidant activity of DCM fraction revealed the highest activity having IC50 values 54.74 μg/mL. No significant cytotoxicity was observed on both HeLa and Vero cell lines.
Dhaka Univ. J. Sci. 68(2): 167-170, 2020 (July)
A Comparative Analysis of Monte Carlo and Quasi-Monte Carlo Methods in Financial Derivative Pricing
Authors: Hossen SM Arif , Hossain ABM Shahadat 
Published: July 2021

The main purpose of this dissertation is to study Monte Carlo (MC) and Quasi-Monte Carlo (QMC) methods for pricing financial derivatives. We estimate the Price of European as well as various path dependent options like Asian, Barrier and American options by using these methods. We also compute the numerical results by the above mentioned methods and compare them graphically as well with the help of the MATLAB Coding.
Dhaka Univ. J. Sci. 69(1): 1-6, 2021 (January)