Journal of Science and Technology Research https://banglajol.info/index.php/JSciTR <p>Published by the <a href="https://most.gov.bd/site/view/publications/%E0%A6%AA%E0%A7%8D%E0%A6%B0%E0%A6%A4%E0%A6%BF%E0%A6%AC%E0%A7%87%E0%A6%A6%E0%A6%A8/%E0%A6%AA%E0%A7%8D%E0%A6%B0%E0%A6%95%E0%A6%BE%E0%A6%B6%E0%A6%A8%E0%A6%BE%E0%A6%B8%E0%A6%AE%E0%A7%82%E0%A6%B9" target="_blank" rel="noopener">Ministry of Science and Technology (MoST), Govt. of the People’s Republic of Bangladesh</a>. Full-text articles available.</p> <p><a href="http://creativecommons.org/licenses/by/4.0/" rel="license"><img style="border-width: 0;" src="https://i.creativecommons.org/l/by/4.0/88x31.png" alt="Creative Commons Licence" /></a><br />Articles in the <em>Journal of Science and Technology Research</em> are Open Access articles published under the Creative Commons CC BY License <a href="http://creativecommons.org/licenses/by/4.0/" rel="license">Creative Commons Attribution 4.0 International License</a>.</p> en-US sahaml@yahoo.com (Professor Dr. Mihir Lal Saha) banglajol.info@gmail.com (Md Fahmid Uddin Khondoker) Mon, 03 Jul 2023 00:00:00 +0000 OJS 3.3.0.6 http://blogs.law.harvard.edu/tech/rss 60 Organoleptic and Biochemical Analysis of Traditional and Customized Product of Shidhils https://banglajol.info/index.php/JSciTR/article/view/67364 <p>A detailed survey was conducted to collect information on the present status of traditional preparation procedure of <em>Shidhil </em>at the Northern region of Bangladesh. A total of 10 samples of traditionally prepared <em>Shidhil </em>was collected from Rangpur, Kurigram and Nilphamari districts and brought to the Department of Fisheries Technology in zipper polythene packets. Proximate composition of the traditionally prepared <em>Shidhil </em>showed that, percent moisture content in Rangpur samples was higher than other samples whereas the percent protein found higher in kurigram samples. Customized product of improved <em>Shidhils </em>were prepared in the same laboratory with kachki (<em>Corica soborna</em>), mola (<em>Amblypharyngodon mola</em>), punti (<em>Puntius ticto</em>) and mixture of these three species of fishes. The survey on traditional preparation procedure of <em>Shidhil </em>revealed that the traditional preparation procedure of <em>Shidhil </em>is quite similar among the districts though there were some differences in shape and weight. Variations were observed in the price of <em>Shidhils </em>per piece and it ranged from 10 to 40 taka/piece. No wholesaler could be found in the marketing channel of <em>Shidhil </em>and it is prepared mostly for home consumption. The biochemical study of the improved <em>Shidhils </em>showed that the percent mean value of moisture, protein lipid and ash of dried fishes obtained at the initial stage changed while <em>Shidhil </em>was prepared using these dry fishes. In the case of kachki fish percent moisture content increased from were 16.12 to 23.84. The percent mean value of protein of dried punti fish were 51.48 which decreased to 41.07% after preparing <em>Shidhil</em>. On the other hand, the percent lipid value was 15.08 for dried mola which increased to 24.25 in mola <em>Shidhil</em>. In the case of mixture of three species of these fishes the percent mean value of ash was 12.73 which decreased 10.38 after preparing <em>Shidhil</em>.</p> <p>J. of Sci. and Tech. Res. 4(1): 01-12, 2022</p> M I Hossain, F H Shikha, M M Hossain Copyright (c) 2022 M I Hossain, F H Shikha, M M Hossain https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67364 Mon, 03 Jul 2023 00:00:00 +0000 Mushroom Powder Ameliorates the Metabolic Syndromes by Maintaining Glucose and Lipid Homeostasis in High Sugar Diet-fed Mice https://banglajol.info/index.php/JSciTR/article/view/67365 <p>Diets high in added sugar both directly and indirectly promote the development of metabolic diseases such as diabetes and obesity. The objective of this study was to evaluate the effects of mushroom powder (MP) in preventing the development of metabolic disorders caused by a high sugar diet. Swiss albino male mice were fed with normal diet (ND) or high sugar diet (HSD) in supplementation with or without mushroom powder. The results showed that supplementation of MP in high sugar diet effectively reduced the food intake and body weight of mice. Moreover, MP sustained glucose tolerance in HSD-fed mice and a significantly lower glucose level was observed in the MP supplemented group than that of the HSD group. Furthermore, kidney and heart weight were almost similar among the groups. However, MP supplementation significantly reduced the liver weight in comparison to that of HSD control group. The wet weights of white adipose tissue and brown adipose tissue were also lower in the MP supplemented groups in comparison to that of HSD group. In addition, supplementation of MP in the high sugar diet significantly decreased the level of total cholesterol, triacylglycerides, and LDL content. In conclusion, these results suggest that mushroom powder was effective in preventing the development of diabetes and obesity induced by a high sugar diet. As mushroom powder is an abundant source of nutrients, therefore, this powder can be an important dietary supplement for treating metabolic disorders instigated by a high-sugar diet.</p> <p>J. of Sci. and Tech. Res. 4(1): 13-24, 2022</p> R Chacrabati, K Khatun, M K H Kazal, R J Moon, D K Bhattacharjya, M A Hossain, C Goswami Copyright (c) 2022 R Chacrabati, K Khatun, M K H Kazal, R J Moon, D K Bhattacharjya, M A Hossain, C Goswami https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67365 Mon, 03 Jul 2023 00:00:00 +0000 Exogenous Testosterone Causes Delayed Postnatal Testicular Development and Disrupts Spermatogenesis https://banglajol.info/index.php/JSciTR/article/view/67366 <p>Proper postnatal development of testis is prerequisite for acquisition of full functional potential of testis. The initiation and maintenance of spermatogenesis depend on testosterone, and the production of mature sperm is highly reliant on androgen activity in the testis. The goal of the study was to investigate the effect of exogenous testosterone on testicular biometry and histomorphometry, and seminiferous epithelium in Black Bengal goat during the postnatal development. A total of 42 Black Bengal goats were divided into two categories: control and testosterone-treated; and each group again subdivided into seven groups (n=3) according to age, <em>viz. </em>group-I (at birth or day 0; d0), group-II (1 week of age), group-III (2 weeks), group-IV (1 month), group-V (2 months), group-VI (4 months), and group-VII (6 months). Goat kids of testosterone-treated group were injected with testosterone hormone @ 125 mg/kid (0.5 ml of Testanon™ 250 Injection, IM, 250 mg/ml, Nuvista Pharma Ltd., Bangladesh) IM weekly until the sample collection. The testicular development was slow up to 2 weeks of age, and after that, in control goats, a quick growth of the testicles was seen. In contrast, a slow trend of testicular development was continuous throughout the study period (postnatal 6 months) in testosterone-treated goats. A continuous and gradual developmental process of testis was observed in control goats. Seminiferous tubules were shown to have a marked increase in diameter at 4 months indicates initiation of spermatogenesis at this age, and completion of the first wave of spermatogenesis, <em>i.e</em>. establishment of spermatogenesis was observed by 6 months of age as confirmed by the presence of all types of cells of spermatogenic lineage in the seminiferous epithelium including spermatozoa were found attached to the Sertoli cells at their ad luminal border, and in the lumen of the seminiferous tubules. Continuous administration of exogenous testosterone exerted a negative effect on the postnatal developmental process of testis of Black Bengal goats. The postnatal developmental process of testis was very slow, and the proliferation of spermatogonia and lumenization of the seminiferous tubules, also known as seminiferous epithelium stratification, were not seen in testosterone-treated goats until they were 6 months old indicates delayed postnatal testicular development and disrupts spermatogenesis.</p> <p>J. of Sci. and Tech. Res. 4(1): 25-36, 2022</p> M R Gofur, A Khatun, M S Sadi, S Aktar, M E Alam Copyright (c) 2022 M R Gofur, A Khatun, M S Sadi, S Aktar, M E Alam https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67366 Mon, 03 Jul 2023 00:00:00 +0000 Modeling and Simulation of Efficiency of Five Junction Solar Cell Using MSCS-1D Simulator https://banglajol.info/index.php/JSciTR/article/view/67367 <p>The third-generation multijunction solar cell (MJSC) is the most promising solar cell in terms of champion photoconversion efficiency. This advanced photovoltaic solar cell is considered as the future green electricity source to meet the gradually increasing terrestrial energy demand. Usually, MJSC consists of 2 to 6 semiconducting materials. These materials work as the sub-cells or sublayers in a multijunction solar cell. This sub-cell is selected in a fashion so that it can absorb the entire solar spectrum. In this project, the efficiency of a novel solar cell has been investigated. A detailed analysis of each sub-cell has been done using the state-of-the-art MSCS-1D simulation software. The materials of each sub-cell of the solar cell have been selected so that they can efficiently utilize the entire ultraviolet to infrared spectrum. The optoelectronic parameters used in the simulation were collected from the standard references. The photoconversion efficiency of this model is simulated to be 48.29% and 59% for AM1.5G solar radiation under one sun and 500 sun conditions, respectively. These simulation results will assist in realizing the performance of the 5-junction solar cell in practical fabrication.</p> <p>J. of Sci. and Tech. Res. 4(1): 37-48, 2022</p> M A Rahman, M Hasan, A Kowsar, S C Debnath, M Rahaman, M L Palash Copyright (c) 2022 M A Rahman, M Hasan, A Kowsar, S C Debnath, M Rahaman, M L Palash https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67367 Mon, 03 Jul 2023 00:00:00 +0000 Evaluation of Liquefaction Potential Index and Severity Mapping for Rangpur City Corporation https://banglajol.info/index.php/JSciTR/article/view/67368 <p>This paper aims to investigate the Liquefaction Potential Index (LPI) of different Wards and prepare a liquefaction severity map of Rangpur City Corporation. A Liquefaction severity map of a city helps the legislators and policymakers with informed land use planning as well as the development of the town. Disturbed soils from 10 Wards among 33 Wards of Rangpur were collected for different depths in a single borehole. The locations for the borehole were selected based on the seismic soil profile and engineering geology reports available for Rangpur City Corporation in CDMP-II. Standard Penetration Test (SPT) and Microtremor test were done on the field. Then, the Grain Size Distribution test and Liquefaction Potential Index (LPI) were determined for the collected samples in the laboratory. Based on the results of the tests done in the field and laboratory, the severity was classified as moderate, moderate to severe, and severe. Based on the Liquefaction Potential Index (LPI) value, four Wards of Rangpur City Corporation fall within the moderate risk class, three Wards show moderate to severe risk of liquefaction, and the remaining 3 Wards belong to the severe risk class.</p> <p>J. of Sci. and Tech. Res. 4(1): 49-58, 2022</p> R Ahsan, M A Ansari, S Aziz, S Zahan Copyright (c) 2022 R Ahsan, M A Ansari, S Aziz, S Zahan https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67368 Mon, 03 Jul 2023 00:00:00 +0000 Waste Tyre Pyrolysis Oil: Production, Sulfur Removal and Fractionation for Value Added Products https://banglajol.info/index.php/JSciTR/article/view/67369 <p>Scrap tyres, one of the most common solid wastes, are increasing with the increase of vehicles number all over the world. Gradual depletion of fossil fuel requires a rapid shift towards alternative fuel sources including wastes. Globally, a lot of pyrolysis oil is generated from the management of waste tyres. The product Tyre pyrolysis Oil (TPO) has a parametric effect on the temperature, feed size, and reaction or pyrolysis time. This study explores the conditions for optimum pyrolytic oil yield (42% wt.) which was 500 ºC for 50 minutes, with a sample size of 4 cm3. The obtained TPO were fractionated at various temperature ranges using a distillation column. The fuel characteristics of TPO, e.g., viscosity, flash point, pour point, calorific value, density, carbon residue are almost similar to that of the conventional oil standards but it cannot directly be used in the combustion process due to its higher sulfur content. For the removal of the sulfur compound, a various concentration ratio (10, 15, 20, 25, 30 percentages) of a mixture of H2O2 and HCOOH (2:1) solution (maintaining a pH of 4) were mixed with TPO. A maximum of 64.52% sulfur was removed from the TPO by using 25% of H2O2 + HCOOH solution and the pyrolysis gas was passed through the Ca(OH)2 solution for wet scrubbing of SO2, CO2 and water vapor. The fractionated TPO (based on temperature range) provides valuable products e.g., bio-gasoline, biodiesel and other desirable chemicals. The production and eco-friendly use of TPO and its fractionated products can mitigate the disposal problem of waste tyre and help the eco-system to attain a sustainable environment.</p> <p>J. of Sci. and Tech. Res. 4(1): 59-70, 2022</p> M Ismail, M G Mahmud, H R Ahmmed, M S Islam, K Kirtania Copyright (c) 2022 M Ismail, M G Mahmud, H R Ahmmed, M S Islam, K Kirtania https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67369 Mon, 03 Jul 2023 00:00:00 +0000 Role of Rhizosphere Bacteria Isolated from Wild-type Varieties of Sundarbans to Endure Salt Tolerance https://banglajol.info/index.php/JSciTR/article/view/67370 <p>Bangladesh is a low-lying riverine country where a large number of populations live in the saline zone. Salinization is a burning issue around the world that affect the plant growth as well as crop production. Due to soil salinization, a fifth of the world's agricultural land has been spoiled. From the geographical setting, Bangladesh is one of the most vulnerable countries to the impact of various natural hazards and disasters. Sundarbans also experienced such natural hazards and disasters, e.g., tsunamis, floods, and cyclones every year for being its location. Moreover, the study area's salinization level is increasing daily. As a result, the plants in the study area are facing a critical situation due to the rapidly changing saline levels. The study attempted to analyze rhizosphere bacteria isolated from wild-type varieties of Sundarbans to endure salt tolerance. This study was conducted using primary and secondary data. Wild-type variety and soil samples were collected from the Sundarbans. To isolate salt-tolerant bacteria, different concentrations of salt were used. The salt tolerance isolates were used to observe the role of seed germination and plant growth. The isolated salt-tolerant bacteria showed their effects on plant growth and seed germination in saline soil. <em>Bacillus </em>and <em>Acinetobacter </em>bacterial species were identified using 16S rRNA gene sequencing, which promoted plant growth and seed germination at a high salt level. Since rhizosphere bacteria play an essential role in enduring salt tolerance, it can be a straightforward and eco-friendly strategy to reduce plant salt stress.</p> <p>J. of Sci. and Tech. Res. 4(1): 71-80, 2022</p> M A H Mostofa Jamal, M A Kabir, A Reza, S Ahmed, F N Tahia, N Naznin, S Akter, A C Paul Copyright (c) 2022 M A H Mostofa Jamal, M A Kabir, A Reza, S Ahmed, F N Tahia, N Naznin, S Akter, A C Paul https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67370 Mon, 03 Jul 2023 00:00:00 +0000 Air Pollution in Dhaka City During Wintertime: Local vs. Transboundary Transport https://banglajol.info/index.php/JSciTR/article/view/67371 <p>Air pollution is considered as the largest environmental health threat in the world. Last few years, it has also increased dramatically in different cities of Bangladesh. The air pollution of Dhaka city as well as other urban areas is very crucial for a sustainable environment. This research is mainly concentrated on studying a variety of air pollutants both qualitatively and quantitively during wintertime and checking the transboundary air pollution of Dhaka City. In the study area, air pollution was found to be at very dangerous levels. Even, air pollution has been found to be significantly higher in concentration during nighttime in Dhaka City. According to public perception and health physicians, air pollution causes many health problems such as eye irritation, headaches, COPD problem, skin cancer, hypertension, cardiovascular diseases, nausea, and asthma. Regular air quality monitoring can be effective for proper control measures of pollutants emissions that may protect the inhabitants from various illnesses. It can provide a guideline for the sustainable development of environment of city dwellers.</p> <p>J. of Sci. and Tech. Res. 4(1): 81-90, 2022</p> M L Hossain, A K M Lutfor Rahman, N Ahmmad, M A A Sheikh, T T Arzina, T B Shiraj, M M Haque Copyright (c) 2022 M L Hossain, A K M Lutfor Rahman, N Ahmmad, M A A Sheikh, T T Arzina, T B Shiraj, M M Haque https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67371 Mon, 03 Jul 2023 00:00:00 +0000 Evaluation of the Synergistic Effect of Azadirachta indica-based Silver Nanoparticles in Combination with Antibiotics and Hypoglycemic Drugs: In vitro Antimicrobial and In vivo Antidiabetic Activities https://banglajol.info/index.php/JSciTR/article/view/67372 <p>This study was conducted to evaluate the synergistic effects of the mixtures of green silver nanoparticles (AgNPs) with ampicillin and metformin separately in obviating the global threats of antimicrobial resistance and diabetes mellitus. AgNPs was synthesized using <em>Azadirachta indica </em>aqueous leaf extract at varying extract concentration and incubation time. The synthesis of AgNPs in aqueous solution was confirmed by the visual color change and by using a UV-Vis spectrophotometer. The biosynthesized AgNPs was further characterized using Scanning Electron Microscope (SEM) analysis. The experimental results revealed that the biosynthesized AgNPs were polydispersed, smaller in size and aggregated. The mean diameter of the formed AgNPs was 50 nm as evident from the SEM analysis. Additionally, the mixtures of AgNPs with ampicillin and metformin exhibited synergistic <em>in vitro </em>antimicrobial and <em>in vivo </em>antidiabetic effects i.e., being more efficacious than AgNPs, ampicillin and metformin alone.</p> <p>J. of Sci. and Tech. Res. 4(1): 91-100, 2022</p> Z Sultana, S Aktar, M M Rahman, A S M A Haque Akand, A Ud Daula, M A K Tang, D K Paul, B S Azhar, M S Raza, A T M Mijanur Rahman Copyright (c) 2022 Z Sultana, S Aktar, M M Rahman, A S M A Haque Akand, A Ud Daula, M A K Tang, D K Paul, B S Azhar, M S Raza, A T M Mijanur Rahman https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67372 Mon, 03 Jul 2023 00:00:00 +0000 Genetic Diversity, Population Structure and Demographic History of Orange Mud Crab Scylla Olivacea from the Bay of Bengal, Bangladesh and Adjacent Seas in the Northern Indian Ocean Based on Mitochondrial COI Gene Sequences https://banglajol.info/index.php/JSciTR/article/view/67373 <p>In this study, we analyzed mitochondrial COI gene sequences to reveal genetic diversity, population structure and demographic history of two Bangladeshi (BD) populations (SB and CK) of the orange mud crab <em>Scylla olivacea </em>of the Northern Bay of Bengal (BoB), and compared these two with other four populations in the Northern Indian Ocean region (Arabian Sea, Andaman Sea and Malacca strait) and South China Sea. For all of the populations, nucleotide diversities were low (0.005–0.01) while the haplotype diversities were as high as 0.70–0.96, indicating that the <em>S. olivacea </em>has undergone a recent population expansion after experiencing bottleneck. The pairwise population statistics (<em>F</em>ST) revealed that no genetic variation was made between SB and CK populations of BD in BoB. However, these two BoB populations showed separate genetic structure with each of the Andaman Sea (Myanmar coast, MM) and Malacca strait (West coast of Malaysia, MS) populations. On the other hand, two BoB populations did not form separate genetic structure from the population of Arabian Sea (AS). Larval dispersal-based migration by the East and West India coastal currents probably caused this genetic homogeneity between BoB and AS populations.The MM population had separate genetic structure from all of the populations studied in the present study. The Hierarchical analysis of molecular variance (AMOVA) revealed four large population groups of <em>S. olivacea </em>within its distribution range in the Indo-west Pacific region namely, Arabian Sea, Bay of Bengal, Andaman Sea and South China Sea groups. Some geographical barriers (<em>e.g. </em>Indian peninsula, Andaman and Nicobar Islands) along with seasonally formed marine gyres in the Andaman Sea are responsible for separate genetic structure among different populations and also for establishing four population groups. Star-shaped patterns of haplotype network and neutrality test corroboratethe recent population expansion of all populations except MM and CK. Mismatch distribution analysis reveals that the demographic expansion of the species started during the late Pleistocene period approximately 125,000 to 365,000 years ago. These results will help to establish the conservation and management strategy for orange mud crab in the Northern Indian Ocean region including the Bay of Bengal.</p> <p>J. of Sci. and Tech. Res. 4(1): 101-118, 2022</p> K A Habib, S Akter, M J Islam, S Sarkar, P S Brishti, M B Billah, M A Hannan Copyright (c) 2022 K A Habib, S Akter, M J Islam, S Sarkar, P S Brishti, M B Billah, M A Hannan https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67373 Mon, 03 Jul 2023 00:00:00 +0000 Relationship between Vitamin D Status in Acute Ischemic Stroke for Assessing Initial Severity and Short-Term Outcome in a Tertiary Level Hospital, Bangladesh https://banglajol.info/index.php/JSciTR/article/view/67374 <p>Recent studies suggest that vitamin D, a neuroprotective prohormone, which has a potential protective role against neurovascular injury. Low vitamin D levels were modestly associated with risk of stroke and stroke fatality.</p> <p><strong>Objective:</strong> This study aimed to investigate the relationship of vitamin D status among acute ischemic stroke patients for assessing initial severity and short-term outcome.</p> <p><strong>Methods:</strong> Fifty one acute ischemic stroke patients and 51 matched healthy control subjects participated in the study. Subjects were divided according to vitamin D level into deficient, insufficient, and sufficient groups. National Institute of Health Stroke Scale (NIHSS) on admission and after 72h and modified Rankin Scale (mRS) on discharge and after 3months were performed for all patients.</p> <p><strong>Results: </strong>Acute ischaemic stroke patients (9.8%) had significantly lower serum vitamin D levels compared to healthy subjects (5.8%). In patients, serum vitamin D level ranged from 5 to 41ng/ml with a mean of 19.4<strong>±</strong>9.98ng/ml. In controls, serum vitamin D levels ranged from 6 to 48ng/ml with a mean of 30.3<strong>±</strong>10.48 ng/ml. Vitamin D deficiency and insufficiency were significantly prevalent among stroke patients (66.7%) compared to healthy controls (51.9%). Significant correlation was detected between serum vitamin D and NIHSS scores on admission and after 72hrs (p=0.007). Significant correlation was also detected between serum vitamin D and mRS scores on discharge and after 3months (p=0.004). The patients with 'not sufficient' vitamin D (i.e. deficient and insufficient) were 11.2 time more likely to report severe stroke (p=0.006). <strong>Conclusion:</strong> Vitamin D deficiency increases the risk of acute ischemic stroke and is associated with increased initial stroke severity and worse short-term outcome.</p> <p>J. of Sci. and Tech. Res. 4(1): 119-128, 2022</p> A Rahman, M J Ahmed, A H Russel, M N Huq, M N Amin Miah, Z Ali Copyright (c) 2022 A Rahman, M J Ahmed, A H Russel, M N Huq, M N Amin Miah, Z Ali https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67374 Mon, 03 Jul 2023 00:00:00 +0000 Heat-Flux Effect on Fluid Flow and Convective Heat Transfer through a Rotating Curved Micro-Channel https://banglajol.info/index.php/JSciTR/article/view/67375 <p>The present paper investigates heat-flux effect and the dissemination of energy in a rotating bent square micro-channel (MC) subject to a temperature gradient between the vertical sidewalls. The flow structure prevailing the problem is solved by applying a highly accurate spectral-based numerical scheme. The flow controlling parameters are the Dean number (0&lt;<em>Dn</em>≤5000) and the Taylor number (-500 ≤ <em>Tr </em>≤ 2000) for curvature 0.01 and the Grashof number, <em>Gr</em>=1000. After applying the arc-length path continuation technique to obtain steady solution (SS) curves, two branches of SS consisting of 2- to 8-vortex solutions are prevailed for the non-rotating case while a single branch with a symmetric 2-vortex solution is for positive rotation of the channel. Unsteady flow (UF) properties are simulated by the time-average of the solutions, and the transitional behavior is well predicted by contemplating the power spectrum and phase spaces of the solutions. Results manifest that the UF experiences a consequence ‘steady-state àmulti-periodic àsteady-state’ for no rotation of the channel as <em>Dn </em>is increased. For the rotating case, on the other hand, the flow advances in the scenario ‘steady-state àmulti-periodic àsteady-state’ for negative rotation and only a steady-state solution for rotation in the positive direction. Streamlines and isotherms of SS and UF for various values of the flow-controlling parameters are obtained. Centrifugal force impacts the fluid mixer, which then assists to turn the flow into chaos and prompts to intensify the convective heat transfer (CHT).</p> <p>J. of Sci. and Tech. Res. 4(1): 129-144, 2022</p> S C Adhikari, R K Chanda, R Akter, R N Mondal Copyright (c) 2022 S C Adhikari, R K Chanda, R Akter, R N Mondal https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67375 Mon, 03 Jul 2023 00:00:00 +0000 Synthesis and Characterization of Eco-friendly, Biodegradable Plasticized Starch Nanocomposite using Graphene Oxide Nano-filler for Energy Storage Applications https://banglajol.info/index.php/JSciTR/article/view/67376 <p>In this study, environment-friendly, biodegradable nanocomposite has been fabricated using plasticized starch (PS) polymer and graphene oxide (GO) nanofiller. Biodegradable PS has been extracted from potatoes and a solution casting technique was used to synthesize PS/GO nanocomposite. The structural and surface morphological properties of the nanocomposite have been studied via FTIR and FESEM which demonstrate increased degree of interaction between the PS matrix and the GO nanofiller. The thermal properties of the nanocomposite showed that incorporation of GO improves the thermal stability of the nanocomposites. To study the energy storage capabilities of the PS/GO nanocomposites the electrochemical properties of the nanocomposites were as studied through cyclic voltammetry (CV), and galvanostatic charge-discharge (GCD) methods. The PS/GO nanocomposite showed improved capacitive performance with a specific capacitance of 112 F/g compared to that of pure starch (2.20 F/g) at a current density 0.1 mA/cm2. To study the effect of GO on the electrochemical properties of the nanocomposites, electrochemical impedance spectroscopy was performed and the corresponding graphs were simulated using simulation software. The incorporation of GO reduces the charge transfer resistance and thereby improve the capacitive performance. The improved electrochemical performance of the PS/GO nanocomposite can be further attributed to the large surface areas provided by the GO sheets allowing faster transport of electrolyte ions into the electrode. The result indicates that the PS/GO and nanocomposites may offer a promising route for the synthesis of bio-friendly and flexible energy storage devices.</p> <p>J. of Sci. and Tech. Res. 4(1): 145-154, 2022</p> S Islam Mollik, E Mahmud, M F Mina, M R Islam Copyright (c) 2022 S Islam Mollik, E Mahmud, M F Mina, M R Islam https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67376 Mon, 03 Jul 2023 00:00:00 +0000 Microbial Profiles and Patterns of Antibiotic Susceptibility of Bacterial Isolates from Edible Sprouts of Flaxseeds (Linum usitatissimum L.) https://banglajol.info/index.php/JSciTR/article/view/67377 <p>Flaxseed (<em>Linum usitatissimum L</em>.) is a plant-based food that provides healthy fat, antioxidants, and fiber. It is referred to as a "functional food" by certain individuals, which suggests that someone can eat it to improve their health. A study on sprouted flaxseed produced in the laboratory revealed the presence of microbial flora, namely bacteria and molds, which is of concern for the health-conscious public. A total of 39 flaxseed sprout samples were cultured to evaluate microbial profiles and to determine antibiotic susceptibility patterns by the Kirby-Bauer Disc diffusion method. Bacterial isolates were tested only against 11 antibiotics, viz. Amoxycillin, Gentamicin, Ciprofloxacin<strong>, </strong>Colistin, Meropenem, Cefixime, Azithromycin, Mecillinam, Cotrimoxazole, Cefaclor, and Moxifloxacin. 39 (100%) of the 39 flaxseed sprout samples cultured tested positive for bacteria and molds. Among them, positive cultures, single bacterial growth, multiple bacterial growth, and molds were 33 (84.6%), 6 (15.4%) and 39 (100%) respectively. The most predominant organisms were <em>Serratia marcescens</em>, comprising 15(33.3%), followed by <em>Citrobacter freundii </em>10(22.2%), <em>Pseudomonas aeruginosa </em>9(20.0%), and other bacterial isolates were <em>Enterobacter cloacae complex</em>, <em>Morganella morganii, </em>and <em>Aeromonas hydrophila</em>, whose frequencies were 6(13.3%), 4(8.9%) and 1(2.2%) respectively. All of the bacterial isolates were 100% sensitive to Ciprofloxacin, Gentamicin, Mecillinam, and Moxifloxacin, and only two antibiotics were shown 100% resistance in Amoxicillin and Cefixime. Based on the results, it is suggested that consumers should pay attention to producing with hygienic techniques and cooking properly to avoid foodborne diseases from flaxseed sprouts</p> <p>J. of Sci. and Tech. Res. 4(1): 155-164, 2022</p> M Z Abedin, R Y Shilpi Copyright (c) 2022 M Z Abedin, R Y Shilpi https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67377 Mon, 03 Jul 2023 00:00:00 +0000 Development and Testing of Waste poly(Vinyl Chloride) Based Solvent Cement for Bonding of poly(Vinyl Chloride) Pipes and Fitting https://banglajol.info/index.php/JSciTR/article/view/67378 <p>Recyclates of waste poly(vinyl chloride) (wPVC) fill materials were used to produce solvent cement. Recyclates of wPVC were made by mechanical recycling of wPVC sheets from power plant cooling tower fill materials. Recyclates of wPVC were analyzed and used to develop solvent cement for bonding of PVC pipes and other molded objects. The formulation of wPVC based solvent cement was optimized. Virgin PVC based solvent cement was also made by applying the same optimized conditions to compare it with wPVC based solvent cement. The newly developed solvent cements were analyzed and applied to PVC pipes to find out their bonding strength compared with the bonding strength of commercial solvent cement. There were no significant differences in the results of these three different solvent cements. So recycling of wPVC into solvent cement is suitable for PVC pipes bonding applications and it has a great potential to achieve benefits for the economic and environmental conditions.</p> <p>J. of Sci. and Tech. Res. 4(1): 165-172, 2022</p> S Sultana, M K U Sarker, S A Eti Copyright (c) 2022 S Sultana, M K U Sarker, S A Eti https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67378 Mon, 03 Jul 2023 00:00:00 +0000 Isolation of Bacteriophages and Their Potential as a new Biological Weapon for Controlling Bacterial Disease of Rice in Bangladesh https://banglajol.info/index.php/JSciTR/article/view/67379 <p>Rice bacterial diseases are one of the major hindrances to achieving crop production across the world, particularly in Asian countries. Bacterial brown stripe (BBS) caused by <em>Acidovorax oryzae </em>(Ao) is one the major diseases of rice responsible for high economic losses. To combat the diseases, this study aimed to isolate and characterize lytic phages infecting Ao, which would serve as potential biological agents for the management of BBS. In this regard, three lytic bacteriophages were isolated from diseased rice leaves in Bangladesh. In this study, the 10 bacterial strains of Ao were identified based on 16S gene sequence analyses, which were screened with their respective phages isolated in this study. Phage AP-1 infected 6 strains of Ao bacteria out of 10 with the most increased titer of plaque in AP-3. All phages showed different titer ranging from 1.19x1010-3.28x1010 for Ao phages. In the host exopolysaccharide production, the Ao phage AP-3 had the highest inhibition of biofilm formation of strains TNGAo-01 of Ao bacteria but the phage AP-2 inhibited significantly by 48.08% as compared to control. Interestingly, all the phages used behaved differently with regard to each of the experiments conducted. These results suggest that all the phages need to be combined in a cocktail to serve as efficient biological control agents in the control of bacterial brown stripe disease caused by <em>A. oryzae </em>in rice.</p> <p>J. of Sci. and Tech. Res. 4(1): 173-182, 2022</p> M M I Masum, S Pandit, C Saha, M A Kader Copyright (c) 2022 M M I Masum, S Pandit, C Saha, M A Kader https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67379 Mon, 03 Jul 2023 00:00:00 +0000 Screening of Antimicrobial and Antioxidant Properties of Ethylenediamine Mono-dithiocarbamate to Overcome the Resistance of Microbes Against Existing Drugs https://banglajol.info/index.php/JSciTR/article/view/67380 <p>Excellency of the medical treatment depends on the potentiality of drugs. The increase of the resistance of microbes against drugs is influencing this aspect. Dithiocarbamate has an application in medicine and biology. Therefore, we have synthesized ethylenediamine mono-dithiocarbamate ligand and explored its antimicrobial and antioxidant property. The ligand exhibited moderate antibacterial activity against 13 (thirteen) selected bacteria in disk diffusion method. It showed notable antifungal activity compared to the standard. Therefore, this ligand may be considered as a potential antifungal agent in antifungal drug design. The antioxidant behavior using DPPH assay revealed that this ligand has significant capability in scavenging radicals as compared to standard.</p> <p>J. of Sci. and Tech. Res. 4(1): 183-190, 2022</p> A Sarker, M Irfan Ali, T T Arzina, M Lokman Hossain, M Aminul Haque, A K M Lutfor Rahman Copyright (c) 2022 A Sarker, M Irfan Ali, T T Arzina, M Lokman Hossain, M Aminul Haque, A K M Lutfor Rahman https://creativecommons.org/licenses/by/4.0 https://banglajol.info/index.php/JSciTR/article/view/67380 Mon, 03 Jul 2023 00:00:00 +0000