Volume 02, Issue-1, December 2024

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Now showing 1 - 12 of 12

Analysis of labyrinth-maze-shaped metamaterial for efficient airplane altimeter applications
(Center for Research and Publication (CRP), 2024-12) Hannan, Saif
This paper proposes an analytical description of a unique labyrinth-maze-shaped metamaterial for electromagnetic noise reduction applications in airplane communications systems. The proposed metamaterial has shown a single negative value and negligible reflection coefficient near 5 GHz for FR4 as a dielectric spacer with any thickness. In airplanes, many antennas and radars are used at different frequencies, which sometimes may interfere with other frequencies transmitted from the ground. The proposed metamaterial can eliminate such EM interference at frequencies near 5 GHz. Moreover, the metamaterial has shown incident angle insensitivity up to 180 degrees phi and 80 degrees theta along with TE and TM mode of EM wave. With a solid copper ground, it can act as an absorber with absorptions at 4.12 GHz and 5.248 GHz, which may isolate the altimeter radar system of the airplane from external mid-band 5G frequencies and thus ensure smooth functioning of both the 5G mobile and the airplane altimeter communications systems.
Antimicrobial potentials of leaves of Syzygium fruticosum (Roxb.)
(Center for Research and Publication (CRP), 2024-12) Nasrin, Mst. Samima
The study was designed to investigate the antimicrobial principles of Sygygium fruticosum (Roxb.). The methanolic extract (CME) of leaves of S. fruticosum was successively fractionated with different organic solvents such as petroleum ether (PEF), chloroform (CHF) and ethyl acetate (EAF) to get four fractions: PEF, CHF, EAF and aqueous fraction (AQF). The antibacterial potentials of the extractives were determined using the agar well diffusion method against Bacillus cereus, Stephylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Shigella boydii, and Shigella sonnei. The dilution method was used to calculate the minimum inhibitory concentration (MIC). The antibacterial activity of extractives was mild to moderate level against experimental bacterial strains. Among the extractives, EAF had the highest antibacterial efficacy against bacterial strains. The EAF's MIC value of 32 g/ml indicated that it might be employed as a powerful antibacterial agent.
Bacterial ghost: A novel strategy for medicinal applications
(Center for Research and Publication (CRP), 2024-12) Ali, Md. Sekendar
Bacterial ghost (BG) is an empty cell envelope of bacteria devoid of chromosomal and plasmid DNA and cytoplasmic content. However, it maintains the cellular morphology with native surface characteristics and bio adhesive properties. The widely used method to prepare BG is the protein E-mediated lysis method, which forms transmembrane tunnels through the inner and outer membranes of bacteria. There are also chemical and mechanical methods that lead to the formation of bacterial ghosts without damaging the necessary components and structure of bacteria. Alongside using NaOH, SDS, H2O2, tween 80, β-propiolactone, and 60% ethanol, hydrostatic pressure is also used to expel the cytoplasmic content resulting in pure envelop ghost. Recently developed holin-mediated inactivation, lysozyme, and protein kinase K are also used to kill bacteria, leaving them as BG. It is used in vaccines, immunotherapy of cancer, and a widely accepted delivery system of drugs, antigens, and other active components. The other efficient use of bacterial ghosts is to stimulate humoral and cell-mediated immunity through antigen-presenting cells. Taken together, BG represents a novel and emerging method for developing potential disease prevention and public health.
Covid-19 detection using dominant SMOTE in imbalance classification
(Center for Research and Publication (CRP), 2024-12) Islam, Saiful
Global healthcare systems have faced difficulties since the start of the COVID-19 epidemic. For overburdened hospitals, identifying positive patients is a simple and effective fix. The disproportionate distribution of classes poses a significant challenge in identifying the positive case of COVID-19, leading to biased prediction outcomes favoring dominant classes. Consequently, classifiers struggle to learn from imbalanced datasets, resulting in reduced performance. Various techniques, such as oversampling, undersampling, and hybrid sampling, have been proposed to mitigate this issue. However, the Synthetic Minority Oversampling Technique (SMOTE) remains a commonly utilized resampling method despite its limitations, including class mixture. To address these shortcomings, I introduce Dominant SMOTE, a modified version of SMOTE. The proposed method comprises of developing a dominant sample selection approach based on numerical attribute values from the minority class, and selecting the nearest neighbors from the majority class for each minority class sample based on dominance values to achieve balanced dataset. The proposed method is compared with traditional SMOTE and Out-Layer SMOTE, evaluating accuracy, precision, recall, and F1-score on two benchmark datasets. The results indicate that the proposed model outperforms than both the traditional SMOTE and Out-Layer SMOTE.
In vitro antimicrobial, cytotoxicity, antioxidant and In vivo analgesic activities of methanol extract of Dipterocarpus turbinatus leaves
(Center for Research and Publication (CRP), 2024-12) Abu Sayeed, Mohammad; Ahmad, Muzammil; Kader, Shalah Uddin; Hasan, Mehedi
The study aimed to investigate the antimicrobial, cytotoxic, antioxidant, and analgesic properties of a methanol extract of Dipterocarpus turbinatus leaves. The extract shows a moderate antimicrobial effect against the tested organisms at different concentrations (10-19 mm of zone of inhibition). The percentage of mortality was observed to increase as the dose increased. The LC50 was found to be 408.50 μg/mL which proved the plant to be a good source of novel drugs with less toxicity. It exhibits antioxidant effect revealed by increase in the percentage of scavenging assay observed with increase in concentration. The presence of reductants in MEDT was also revealed. The number of writhing which is a dose dependent shows highest number at a dose of 200 mg/kg body weight i.e., 32.83±1.25 and 28.16±1.89, 15.5±2 for 400 mg/kg of MEDT and 10 mg/kg of Diclofenac-Na respectively. At a dose 0f 200 mg/kg of MEDT, 28.51±0.560 seconds were spent licking the paw while at a dose of 400 mg/kg of MEDT, 23.60±0.545 seconds were spent licking the paw.
In vitro quality assessment of ketotifen fumarate tablets commercially available in Bangladesh
(Center for Research and Publication (CRP), 2024-12) Sayeed, Mohammed Abu
Quality defines the standard of a product and every company strives to achieve it, although it is often challenging. Quality of pharmaceutical products is very important for achieving the therapeutically activity of the standard drugs. This research work was aimed to investigate the quality control parameters of five brands of ketotifen that are available in the market. The five ketotifen brands were collected from the Bangladeshi local market, after which they underwent various physical parameter assessments including weight variation, hardness, friability, potency, disintegration, and acid-base degradation assessments. The brands passed the tests as no tablets crossed the ±10 % weight variation. The percentage friability of the five brands was less than 1%, hence they satisfied the standards. The disintegration time of the tablets did not exceed 5 minutes; therefore, they met the standards. All the brands showed potency ranging from 90 to 110%. In the degradation studies, no products met the USP specified limit. The average hardness of all brands did not meet the standard criterion.
Kattosh (Lasia spinosa (L.) Thwaites) an edible vegetable improve anxiety and depression in animal model
(Center for Research and Publication (CRP), 2024-12) Reza, Ali
Lasia spinosa (L.) thw is utilized in folk medication against different ailments such as diabetic, anxiety and depression. The aim of the present study was to investigate the anxiolytic and antidepression activities of hydroalcoholic extract of Lasia spinosa (HaE-LS) in mice model. This research investigated the effects of hydroalcoholic extract (HaE-LS) L. spinosa in recovery of behavioral changes through its, anxiolytic and anti-depressant impacts. The anxiolytic activity was assessed by elevated plus maze (EPM) test and hole board tests (HBT), anti-depressant effect was appraised by tail suspension tests (TST) and forced swimming test (FST). During the anxiolytic assay by elevated plus maze test, the HaE-LS significantly (p< 0.05) increased the time spent in the open arm 71.67 ± 4.70 sec at the dosages of 400 mg/kg. In HBT HaE-LS exhibited dose-dependent anxiolytic activity. In TST, mice swallowed with 400 mg/kg of HaE-LS demonstrated significant (p< 0.005) immobile time 60.33 ± 2.37 sec.In FST, the HaE-LS displayed reductions in their immobility times, which was significant 75.67 ± 2.33 sec and 61.67 ± 2.33 sec at the dosage of 200 and 400 mg/kg, respectively. Overall, the results recommend that HaE-LS could be a promising beneficial option for the treatment of anxiety and depression disorders
Levosalbutamol Sulphate mucoadhesive buccal thin film formulation design and characterization: Effect of polyethylene glycol 400 as a plasticizer
(Center for Research and Publication (CRP), 2024-12) Morshed, Md Masud
The present study aimed to design and evaluate mucoadhesive buccal thin films of levosalbutamol sulphate to circumvent pre-systemic elimination due to gastrointestinal degradation and hepatic first-pass metabolism. Films were prepared using four water-soluble polymers in varying proportions with PEG-400 as a plasticizer. A total of five formulations were developed and characterized for physicochemical parameters including surface pH, film thickness, folding endurance, mass and content uniformity, density, swelling index, disintegration time, percent moisture absorption/loss (PMA/PML), in vitro drug release kinetics, and ex vivo mucoadhesion time. All evaluations were performed in triplicate to ensure data reliability. The prepared films exhibited high folding endurance (>300), uniformity in mass and thickness, and a surface pH compatible with salivary fluid. Disintegration time and content uniformity met standard criteria. Drug release kinetics followed zero-order in two formulations, Higuchi model in two, and first-order in one. Mucoadhesion times ranged from 2 to 9 minutes, and the films demonstrated satisfactory stability under both dry and humid conditions.
Modified electrophoretic deposition approach for dye-sensitized solar cell application
(Center for Research and Publication (CRP), 2024-12) Choudhury, Md. Shamimul Haque
In this investigation, we are reporting a new electrophoretic deposition approach to prepare a homogeneous, uniform, and crack-free TiO2 photoelectrode for DSSC application. A four-layer deposition technique along with the optimization of the EPD parameters has been applied in this work. To ensure the uniformity of the photoelectrode film, the substrate has been rotated by an angle of 90 degrees before each deposition. The uniformity of the layer is observed by measuring the thickness of the film from each side. The result shows that the proposed technique maintains more uniformity compared to the single-layer deposition and conventional multilayer deposition techniques. It gives relatively a compact layer photoelectrode surface having less amount of crack. The Scanning Electron Microscopy (SEM) image of the photoelectrode surface and photovoltaic performance of the cells confirms that our proposed EPD approach gives a uniform, homogeneous, and compact layer photoelectrode surface with better photovoltaic performance compared to the cells prepared by a conventional single layer or multilayer deposition technique.
Photovoltaic efficacy of WS2 as back surface field (BSF) and SWCNT as an absorber layer for heterostructure solar cell: Numerical investigation by SCAPS-1D multidimensional framework
(Center for Research and Publication (CRP), 2024-12) Uddin, Muhammad Athar
This study presents a highly efficient heterostructure solar cell model using single-walled carbon nanotubes (SWCNTs) as the absorber layer, tungsten di-sulfide (WS2) as BSF layer and platinum (Pt) as the back contact. Using the SCAPS-1D software, the research focuses on optimizing critical design parameters such as the thickness (W) and acceptor concentration (NA) of the absorber layer, along with the impact of as the BSF series-shunt resistance, temperature and defect densities across different layers. The model, ITO/CdS/SWCNT/WS2 configurations, aims to achieve superior PV performances. Key innovations include the incorporation of minority carriers to simulate defects and interfaces defect coefficients depicted through contour plots. The optimized parameters for the ITO/CdS/SWCNT/WS2 model are established at a thickness of 1.5 μm, an acceptor concentration of 4×1019cm−3 and a defect density of 1×1016cm−3, resulting in an efficiency of 30.01% with VOC = 0.86V, JSC = 41.42mA/cm2 and FF = 83.84% achieved at 300oK temperature. These discoveries underscore the considerable promise of SWCNTs functioning as the absorber layer in a heterostructure solar cell, offering promising outcomes for environmental sustainability and global energy solutions
Variations of axial and radial temperature inside the HLTP for microalgae cell growth
(Center for Research and Publication (CRP), 2024-12) Islam, Md. Rashedul
The demand for microalgae-based biofuel has been attracted globally due to huge fuel demand and the global warming crisis. In this study, we simulated the axial and radial temperatures for microalgae cell growth. The computational domain is considered a horizontal loop tubular photobioreactor (HLTP) due to its high productivity. However, due to proper temperature variations, the growth is obtained as expected. We found that for proper cell growth, the standard temperature range is 293K–308K. From our simulation, we observed that the maximum temperature is near 312K through the axial direction and the maximum temperature is near 314K through the radial direction.
Waste cooking fish, palm and sunflower oil based biodiesels: Production, engine performance and emission characteristics
(Center for Research and Publication (CRP), 2024-12) Saifuddin, Mohammed
The aim of this study is to produce biodiesel from waste cooking oils such as fish, palm, and sunflower and to analyze the engine performance and emission properties of these biodiesels. For the biodiesel production the transesterification reaction was followed and methyl esters as well as distilled water were used at 1:1 ratio during the purification process and produced biodiesels were analyzed by GCMS. A total of 7, 5 and 4 types of fatty acids were observed in biodiesels which was derived from fish, palm and sunflower oil, respectively. The kinematic viscosity was observed under the ASTM specified value of all produced biodiesels. Engine tests revealed low carbon monoxide and nitrogen oxides emissions in palm biodiesel as compared to biodiesels made from sunflower and fish oil. In conclusion, waste cooking oil-based biodiesel can be a suitable alternative fuel due to its fuel characteristics, favorable engine performance, and improved emission properties.