Dhaka Univ Research Articles (Page 1)

This study conducts a comparative analysis of ARIMA and ETS models to forecast Bangladesh RMG export trends. Utilizing annual RMG export data from 1983 to 2023, sourced from BGMEA’s website, the research applies a logarithmic transformation to stabilize variance, with differencing exclusively for ARIMA to address non-stationarity. Automated model selection via R’s functions – auto.arima() for ARIMA and ets() for ETS – was implemented to optimize parameter configurations. The optimal ARIMA (2,2,0) and ETS (A, Ad, N) models was trained on data from 1983 to 2015 and validated on the 2016-2023 testing subset. Accuracy metrics, revealed ETS’s superior performance, yielding a lower MAPE (8.47% vs 19.74%) and RMSE (3794.72 vs 8334.12) compared to ARIMA’s. The Diebold-Mariano test confirmed ETS’s statistical superiority at a 15% significance level. The ETS’s adaptability to non-linear trends and damped volatility in RMG underscore its efficacy, while ARIMA’s reliance on linear assumptions limited its applicability. Forecast for 2024-2028 project sustained RMG export growth, emphasizing sector’s economic resilience. These findings advocate for policymakers to inform strategic planning, while highlighting the need for future research integrating external factors through hybrid or machine learning models. Dhaka Univ. J. Sci. 73(2): 101-105, 2025 (July)

The current world of air travel has become significantly option-heavy over the past few decades. There are commercial jet-liners, helicopters, and private jets. In all these advancements in air travel, one aspect has always been of significant importance: ducted-propelled aircraft. A duct, though simple in form, can lead to an increase in the efficiency of an aircraft. The position of the duct, its thickness, its radius, and the material it has been made of all play essential roles in nominating a certain duct for a specific aircraft. In this study, the numerical analysis of turbulent flow through a ducted propeller will be observed, and different aerodynamic coefficients will be computed. This study will show that a ducted propeller is capable of producing significant lift for an automatic or manual aircraft to fly through turbulence. Dhaka Univ. J. Sci. 73(2): 119-126, 2025 (July)

This research investigates the interplay between women’s empowerment and current contraceptive practices among Bangladeshi women, taking into account various socio-economic and demographic factors. The study analyzes data of 18,987 women aged 15-49 from the Bangladesh Demographic and Health Survey (BDHS), 2022. Women’s empowerment is assessed through latent variables related to household decision-making and attitudes toward wife beating using principal component analysis. Chi-square tests and mixed-effect binary logistic regression are employed to scrutinize the unadjusted and adjusted associations. The findings reveal a positive association between women’s empowerment and contraceptive use, highlighting the role of gender equality in fostering communication on reproductive health decisions and improving access to family planning services. Women in the 25–35 and 35+ age groups, urban residents, educated, employed, and media exposed women exhibit higher odds of contraceptive use. The unexpected discovery that wealthier women are less likely to use contraceptives challenges prevailing norms, prompting further exploration. These findings suggest that empowering women can play a crucial role in enhancing reproductive autonomy and access to family planning services. To that end, policy interventions such as education and awareness campaigns, community-based family planning initiatives, mobile health (mHealth) tools, and legal reforms aimed at strengthening women’s rights are essential. Such interventions can bridge socio-economic disparities, foster informed decision-making, and improve reproductive health outcomes across Bangladesh. Dhaka Univ. J. Sci. 73(2): 161-169, 2025 (July)

The proliferation of high-dimensional data has heightened challenges posed by cellwise outliers, where contamination in individual cells distorts analyses more pervasively than traditional rowwise outliers. This study conducts a comprehensive comparison of robust variable selection methods under cellwise contamination, evaluating four rank-based techniques (ALGR, ALRP, LGR, LRP) against traditional approaches (Lasso, Adaptive Lasso, sLTS). Simulations under varying correlation structures, contamination rates (2%, 5%, 10%), and outlier magnitudes (γ = 2, 6, 10) demonstrate that Gaussian Rank correlation-based methods (ALGR, LGR) achieve superior F1 scores, balancing high true positives and low false positives. Real-data applications on life expectancy and crime datasets corroborate these findings, with ALGR and LGR maintaining robustness in low- and high-dimensional settings. Results emphasize the critical need for methods resilient to cellwise contamination in fields reliant on accurate high-dimensional data analysis, such as healthcare and genomics. Dhaka Univ. J. Sci. 73(2): 143-150, 2025 (July)

High-risk-fertility behavior (HRFB) including excessively young or advanced maternal age, narrower birth interval, adhering to higher birth orders, and experiencing an elevated number of live births to a woman often leads to adverse maternal and child health outcomes. The Bangladesh Demographic and Health Survey (BDHS) data was employed to pinpoint the factors motivating high-risk fertility behaviors in women of childbearing age. Pearson’s chi-square test was employed to conduct the unadjusted bivariate association and binary logistic regression model had been implemented to observe the adjusted association between covariates and HRFB. Overall, approximately one-third (31.9%) of women of childbearing age showed risky fertility behaviors. Women’s education, working status, decision-making autonomy, place of residence, husband’s education, husband’s age, media exposure, and violence against women were significant predictors of maternal HRFB. The escalating prevalence of HRFB in Bangladesh is a cause for concern. Policymakers should prioritize initiatives such as enhancing parental education, fostering women's autonomy, and implementing knowledge- based healthcare interventions for women. These measures aim to mitigate risky fertility behaviors and contribute to improved reproductive health outcomes. Dhaka Univ. J. Sci. 73(2): 127-134, 2025 (July)

This study sought to identify key determinants of basic handwashing facility in Bangladesh before and after COVID-19. Data from the Bangladesh Demographic and Health Surveys (BDHS) for 2017–18 and 2022 were analyzed using a Generalized Linear Mixed Model (GLMM) that accounted for fixed effects and cluster-level variations. The prevalence of basic handwashing facility increased from 41.3% to 59.7%. Before COVID-19, significant determinants included division, place of residence, the sex and age of the household head, household size, partner’s education, working status, media exposure, and the age and education of mothers with children under five. After the pandemic, critical factors shifted to the household head’s age, partner’s education, media exposure, women empowerment, wealth index, and the age and education of mothers. These findings suggest that the pandemic accelerated improvements in hand hygiene, emphasizing the need for targeted public health interventions informed by socio-demographic factors. Dhaka Univ. J. Sci. 73(2): 107-117, 2025 (July)

Nowadays, heart illness is somewhat common truth. Both the death rate and frequency are rising daily. In this study, three models-a simple logistic model using linear regression, K-Nearest Neighbors (K-NN), and Support Vector Machine (SVM)-are used for training and testing data in order to accurately predict heart disease. Following preprocessing, a ratio was used to divide the data into train and test sets. The results showed that the Support Vector Machine (SVM) approach was the most accurate model in terms of prediction accuracy, while the K-Nearest Neighbors (K-NN) and Logistic model with linear regression were relatively lesser accurate with respect to the same value of all parameters. To put it succinctly, these three prediction models were able to accurately forecast heart disease and exceeded accuracy. These findings suggest that these models are very practical and effective, and they can give physicians valuable information to help them identify and treat patients with heart disease more accurately. Dhaka Univ. J. Sci. 73(2): 171-175, 2025 (July)

A theoretical calculation into π-π interactions of several benzene derivatives, including aniline, benzonitrile, chlorobenzene, phenol, and toluene, was conducted and documented. All structures have been optimized using the MP2/aug-cc-pVDZ theoretical method. Homodimer of benzene derivatives with various geometrical configurations, including face-to-face, anti-face-to-face, slipped-parallel, and T-shape, have been explored. Variations have been made to the distance between two molecules of each dimer while conserving the geometry of each structure, as determined via geometry optimization. The potential energy curve has been drawn for each configuration, and all of the data for each configuration has been fitted to a polynomial equation. For each configuration, the minimal distance between two molecules at which the interaction energy is the lowest has been determined using a polynomial equation. At distances of 3.47 Å, the slipped parallel structure of aniline is the most stable, with interaction energies of -8.92 kcalmol-1. At 3.41 Å, the anti-face-to-face structure of benzonitrile has the lowest interaction energy of -11.51 kcalmol-1, making it the most stable configuration. At 3.65 Å, the most stable form of chlorobenzene is slipped parallel, which has an interaction energy of -11.14 kcalmol-1. At distances of 3.81 Å and 3.69 Å, phenol and toluene exhibit interaction energies of -10.77 kcalmol- 1 and -10.43 kcalmol-1, respectively. The goal of π-π interactions is to provide a more comprehensive and more up-to-date understanding of the way this interaction works in fields like molecular biology. Dhaka Univ. J. Sci. 73(2): 151-160-68, 2025 (July)

Liquefied Petroleum Gas (LPG) leakage presents a critical safety concern, especially in densely populated urban areas. This study evaluates the seasonal risk dynamics of an LPG release scenario at Meghna Filling station in Dhaka, Bangladesh, Using the ALOHA 5.4.7 air dispersion model to simulate hazard zones under differing atmospheric conditions. Simulations were conducted for both summer and winter conditions to assess toxic gas dispersion, explosion overpressure and thermal radiation hazards based on Acute Exposure Guideline Levels (AGELs) and Lower Explosive Limit (LEL) thresholds. Result show that winter conditions lead to wider dispersion zones across all risk indicators due to increased atmospheric stability and reduced vertical mixing. AGEL-3 concentrations (life- threatening exposure) extended approximately 300 meters in winter compared to approximately 240 meters in summer. Similarly, explosion over pressure zones above 3.5 psi stretched 370 meters in winter, compared to 290 meters in summer. However, in fixed locations near the source, the heat from the gas lasted longer in summer. The thermal radiation intensity that causes second-degree burns (6 kW/m²) stayed about 1 minute in summer, but only 0.4 minutes in winter. These seasonal differences significantly influenced the spatial extent and intensity of hazard zones. The findings emphasize the necessity for season-specific emergency planning and safety measures in LPG storages and distribution facilities to better protect public health and infrastructure. Dhaka Univ. J. Sci. 73(2): 177-186, 2025 (July)

Supported ionic liquid phase (SILP) materials are a novel approach that blend the benefits of heterogeneous support materials and ionic liquids (ILs) by immobilizing an IL film on a solid phase. In an attempt to modify the surface characteristics of nanoparticles, this study explores a simple refluxing method to prepare two novel SILP materials using two supports, graphitic carbon nitride (g-C3N4) and titanium dioxide (TiO2) and a 1,8- diazabicyclo[5.4.0]undec-7-ene (DBU) based protic ionic liquid (PIL), 1,8-diazabicyclo[5.4.0]undec-7-ene-8- ium hydroxide ([HDBU]OH). FTIR spectra showed peaks for N-H stretching mode in the region of 3051-3200 cm-1 indicating the presence of the PIL in g-C3N4-[HDBU]OH and TiO2-[HDBU]OH. The distinctly different UV-visible absorption spectra as reflected in absorption maxima in SILP materials compared to the PIL, [HDBU]OH indicates the formation of new materials. The surface morphology and the size of the particles of the SILP materials were determined from SEM images and DLS measurements. The g-C3N4 nanosheets exhibits significantly cracked surfaces in the SEM image of g-C3N4-[HDBU]OH with average particle size of 9-12 nm. Although significant increase in the surface roughness is noted, the particle size does not change significantly from that of g-C3N4. TiO2 displayed a spherical surface morphology with an increase in particle size from 22 nm to 102 nm for the SILP. [HDBU]OH can interact in various ways with different supports such as g-C3N4 and TiO2 and allows for tailoring size of nanoparticles and surface morphology of the supports in SILP materials. Dhaka Univ. J. Sci. 73(2): 135-142, 2025 (July)

The study aimed to generate weather forecasts for the Rohingya camps in Ukhia and Teknaf by employing a Recurrent Neural Network (RNN) with a Long Short-Term Memory (LSTM) layer alongside a Vector Autoregressive (VAR) model. It utilized six meteorological variables-temperature, humidity, precipitation, surface pressure, wind speed, and wind direction-sourced from NASA’s POWER project. The analysis focused on two sets of areas: control regions in Ukhia and Teknaf that are not impacted by the Rohingya presence, and target regions in the same locations where the Rohingya reside. The findings revealed notable differences in prediction accuracy between the models.The RNN with LSTM demonstrated superior accuracy in control areas, likely due to its ability to capture complex, nonlinear patterns. In contrast, the VAR model outperformed the RNN with LSTM in target areas, suggesting that weather patterns in these regions exhibit more linear relationships. These findings underscore the importance of selecting forecasting models based on the underlying structure of meteorological data to improve prediction accuracy. Dhaka Univ. J. Sci. 73(2): 93-99, 2025 (July)

This paper presents a geometric framework in which our observable three-dimensional universe is modeled as a smooth submanifold—specifically, a slice—embedded within an infinite-dimensional Hilbert manifold. Drawing on classical embedding theorems by Whitney, Nash, Kuiper, and Henderson, we reinterpret established results in differential topology through a novel lens that bridges geometry and physics. We demonstrate that any smooth 3-manifold can be realized as an isometric leaf in a smooth foliation of an infinite-dimensional manifold, and construct such foliations explicitly using smooth normal vector fields along a fixed embedding. We prove that the space of these foliations, parametrized by such fields, forms an infinite-dimensional Fréchet manifold—effectively a moduli space of parallel universes, each represented as a geometric slice. An explicit example using the 3-sphere SS3 embedded in the Hilbert space l 2 is developed, illustrating the theoretical construction in concrete terms. Diagrams and visualization accompany the model to clarify the geometric intuition and moduli variation. Our approach remains purely geometric, independent of physical field equations, yet conceptually resonates with brane world scenarios, emergent gravity, and infinite-dimensional quantum theories. This reinterpretation of classical geometry provides not only a rigorous mathematical result but also opens a pathway toward new models of dimensional emergence and foundational questions in cosmology and ontology. By positioning the universe as a geometric object embedded in an infinitedimensional ambient structure, we offer a new direction for thinking about space, structure, and reality. Dhaka Univ. J. Sci. 73(2): 187-195, 2025 (July)

This study reports the synthesis and characterization of Fe(II), Cd(II), Hg(II) and Co(II) complexes with a Schiff base derived from lysine and salicylaldehyde. Elemental analysis confirmed successful synthesis. UV-Vis spectroscopy revealed significant electronic transitions and metal-to-ligand charge transfers. Thermogravimetric analysis showed distinct thermal decomposition patterns, indicating the stability and composition of the complexes. Magnetic susceptibility measurements indicated paramagnetic behavior for Fe(II) and Co(II) complexes, suggesting tetrahedral geometry, while Cd(II) and Hg(II) complexes were diamagnetic. X-ray diffraction analysis revealed a crystalline primitive lattice structure for the Fe(II) complex, with the Cd(II), Hg(II) and Co(II) complexes being amorphous. The Co(II), Cd(II) and Hg(II) complexes demonstrated substantial antibacterial activity against both gram-positive and gram-negative bacteria. Additionally, the Cd(II) and Co(II) complexes exhibited strong activity against all tested fungal strains. All complexes also showed promising antioxidant activity. Dhaka Univ. J. Pharm. Sci. 24(1): 29-37, 2025 (June)

This study investigates the standardization of quality control and documentation processes for locally grown medicinal herbs in Bangladesh, focusing on enhancing their export potential. Despite Bangladesh's rich biodiversity and a longstanding tradition of using medicinal plants, the export of these herbs is hindered by inconsistent quality and inadequate documentation. Our findings revealed that most producers and collectors have educational qualifications below the Secondary School Certificate (SSC) level and do not adhere to formal guidelines. Key issues identified include a lack of proper documentation practices such as record keeping, accurate labelling, and appropriate packaging. This research highlights the critical need for targeted training and education initiatives to improve adherence to Good Agricultural and Collection Practices (GACP). The study aims to align local practices with international standards by developing a framework that addresses these gaps, ensuring that exported herbs meet global market requirements. The findings are expected to contribute significantly to the sustainable development of Bangladesh's herbal industry and its successful integration into the global market. Dhaka Univ. J. Pharm. Sci. 24(1): 49-66, 2025 (June)

Sarcolobus globosus is a medicinal plant grown in the Sundarbans, exhibiting a spectrum of pharmacological properties. This study was devised to scrutinize the potential antidiabetic attributes intrinsic to S. globosus leaves. In the oral glucose tolerance test (OGTT), the extract displayed a dose-dependent reduction in blood glucose levels compared to the standard glibenclamide. The extract also demonstrated a notable suppression of the alpha-glucosidase enzyme (IC50 = 0.407 mg/ml), juxtaposed against the efficacy of the established standard voglibose (IC50 = 0.329 mg/ml). Cycloartane triterpene, identified as cycloeucalenol, was isolated, exhibiting an IC50 of 0.423 mg/ml. Cycloeucalenol was subjected to MD analysis against the protein model (PDB ID: 3A4A), revealing a binding affinity of –9.4 kcal/mol, exceeding that of voglibose (–6.1 kcal/mol), and closely approximating the binding affinity of acarbose (–9.7 kcal/mol). Afterward, cycloeucalenol and acarbose were subjected to MDS studies to explore thermal stability. In addition, an ADMET analysis was performed, affirming the oral bioavailability and safety profile of cycloeucalenol. Dhaka Univ. J. Pharm. Sci. 24(1): 11-28, 2025 (June)

Gymnema inodorum (Lour.) Decne. (GI) is a climbing plant used as food. There are several different medicinal uses for this plant. Different fractions obtained from the GI stem’s methanolic extract were subjected to pharmacological assays in this study. In the hypoglycemic activity assay, the chloroform fraction at both 200 mg/kg and 400 mg/kg body weight doses demonstrated potent hypoglycemic properties after 60, 90, and 120 minutes, whereas the ethyl acetate fraction showed significant activity after 90 and 120 minutes at both doses. With tail flicking responses elongating by 112.92% (p<0.01), 150.53% (p<0.001), and 257.23% (p<0.001) after 30, 60, and 90 minutes, respectively, the chloroform fraction (400 mg/kg) demonstrated the most prominent central analgesic activity among the test samples in the tail flicking method. Similarly, the chloroform fraction (400 mg/kg body weight) revealed strong peripheral analgesic activity with a 52.18% (p<0.001) writhing inhibition value in the acetic acid-induced writhing inhibition method. All other fractions at both doses had considerable antidiarrheal activity, with the exception of the n-hexane fraction. The n-hexane and ethyl acetate fractions' IC50 values in the DPPH free radical scavenging experiment were 31.5 µg/ml and 35.44 µg/ml, respectively. After subsequent phytochemical analysis, potential bioactive compounds for drug development might be obtained from the GI stems. Dhaka Univ. J. Pharm. Sci. 24(1): 39-48, 2025 (June)

Ketorolac tromethamine and rabeprazole sodium are drugs that are used frequently, and certain clinical conditions warrant their concomitant use. Ketorolac has been known to engage in physical interactions with several drugs that share certain structural features with rabeprazole, and therefore their degree of chemical association was assayed. 0.05 mM solutions of the two drugs were prepared with buffer solutions of pH 1.4, 2.4, and 7.4. Conductometric titrations were conducted for each. The two drugs were observed to form chemical associations with each other on a nearly 1:1 basis in each buffer solution. Sharp breaks in all cases were recorded. Ketorolac has previously been reported to form intermolecular interactions with drug moieties containing amine groups with non-engaging lone-pair electrons, and this was postulated to be the mechanism of action for the interaction. As certain clinical conditions can warrant the concomitant use of these two drugs, additional care must be taken in such cases to avoid unfavorable clinical complications. Dhaka Univ. J. Pharm. Sci. 24(1): 87-94, 2025 (June)

This study investigated the phytochemical constituents and pharmacological potential of Parmentiera aculeata a medicinal plant used traditionally in Central America. Four compounds were isolated and characterized, namely oleic acid (1), methyl palmitate (2), 7,9-pentadecanediol (3), and methyl 5-eicosenoate (4). The ethylacetate-soluble fraction (PAEA) and aqueous fraction (PAA) exhibited potent antioxidant activity (IC50=12.65 µg/ml) which correlated with their high phenolic content (47.62 and 47.54 mg GAE/g, respectively). In the brine shrimp lethality assay, the PAD fraction demonstrated significant cytotoxicity (LC50=0.258 µg/ml) in the brine shrimp lethality assay. PAEA showed excellent thrombolytic activity (45.99%) comparable to the standard (65.09%). All fractions exhibited anti-inflammatory effects, with PAEA and PAA achieving 95.70% and 86.97% inhibition in heat-induced hemolysis, respectively. In hypotonic solution induced hemolysis, only PAA exhibited promising result (49.6%). The plant crude extract (PA) exhibited analgesic activity in the acetic acid-induced writhing assay (p<0.05 for 200 mg/kg, p<0.01 for 400 mg/kg) and antidiarrheal effects (58.97% for both doses, p<0.01). Moreover, PA exhibited a dose-dependent hypoglycemic effect, with a 58.99% reduction in plasma glucose at 400 mg/kg. These findings suggest that P. aculeata possesses promising pharmacological properties and warrants further investigation in order to create possible therapeutic medicines. Dhaka Univ. J. Pharm. Sci. 24(1): 77-86, 2025 (June)

Eye problems are prevalent among Bangladeshi population due to their ignorance regarding eye health. This study investigated the reasons for patients’ visit to an eye hospital and their knowledge about maintaining healthy eyes. Using a questionnaire, data were collected from 110 patients visiting a secondary eye care hospital situated in Savar, Dhaka, Bangladesh. Common reasons behind their hospital visit were blurry vision (45.5%), itchy eye (45.5%) and swollen or red eye (40.9%). Positive history of refractive errors and conjunctivitis were observed among the patients as well as their families. All adult patients (n = 92) knew that eating fruits, vegetables and fishes is good for the eyes. Majority of them were also aware of the importance of wearing protective eyewear (90.2%), knowing family eye health history (85.9%) and giving rest to eyes after electronic device use (81.5%). The positive impact of avoiding or quitting smoking and maintaining a healthy weight on eye health were known to less than half of them. Significantly higher (p < 0.05) knowledge score about eye health maintenance was related to young age, positive family history, male gender, higher education level and higher monthly family income. Therefore, improving the knowledge about maintenance of eye health needs to be addressed with highest importance to lower the continuing burden of visual impairments. Dhaka Univ. J. Pharm. Sci. 24(1): 1-9, 2025 (June)

Molnupiravir, an orally administered antiviral drug originally developed for influenza but not approved, inhibits the replication of SARS-CoV-2 and has been repurposed as an antiviral treatment for COVID-19. This research aimed to develop 400 mg sustained release tablets of molnupiravir for a dosage regimen of two tablets every 12 hours using design of experiment (DoE) approach. The study utilized 32 full factorial design, implemented through the use of Design Expert® software. The formulation was optimized using methocel® K15M and povidone K30 as independent variables, with drug release at 2, 8 and 12 h in pH 6.8 phosphate buffer as the dependent variables. An optimal formulation was identified through statistical analysis and empirical evaluation, requiring 6.84% methocel® K15M and 4.27% povidone K30. The sustained release tablets of molnupiravir exhibited release kinetics consistent with the Hixson-Crowell model. The results of this study allowed us to suggest a new tablet dosage form of molnupiravir, with the objective of enhancing both efficacy and adherence in the treatment of COVID-19. Dhaka Univ. J. Pharm. Sci. 24(1): 67-75, 2025 (June)