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Aims: The study aimed to assess perception of the students about antibiotic consumption and the rise of antibiotic resistance with the view to developing an effective community engagement strategy for antimicrobial stewardship. Methods: A cross-sectional study was carried out from July 2020 to November 2020. The students from Dhaka City, Bangladesh were approached through social media to complete an online questionnaire containing self-identification data, knowledge about antibiotics, attitudes toward antibiotics, and antibiotic consumption. Descriptive statistics were used to analyze the data. Results: Out of the 472 survey participants, 24.6% of participants identified antibiotic side effects as the worst outcome, while 74.2% were unaware of the antibiotics’ long-term impact on global health. Participants believe antimicrobial stewardship and legal disciplinary action against indiscriminate use of antibiotics are the best strategies for countering the spread of antimicrobial resistance. Conclusions: This study has identified knowledge gaps and misconceptions about antibiotic resistance and prevention. In these situations, academics must play a role in training students about the dangers of antibiotic misuse, gathering public opinion in support of effective policy making, and enforcing guidelines and regulations across the healthcare, pharmaceutical, and agricultural industries to prevent the spread of superbugs.

Background One of the most common autosomal recessive hereditary blood disorders in the world, especially in developing countries like Bangladesh. Patients suffering from this disease face physical, emotional, and social problems that lessen their health-related quality of life (HRQoL). Thus, this study aimed to determine HRQoL and its determinants of Thalassemia patients (TP) in Bangladesh using the Short Form-36 (SF-36) questionnaire. Methods A cross-sectional survey was done on 356 randomly selected TP from the Bangladesh Thalassemia Foundation. Participants were invited to face-to-face interviews. Descriptive statistics (frequencies and % ages), independent t-test, ANOVA, and Multivariate (linear and logistic regression) analysis were performed on the collected data. Results Our demographic data showed that among 356 patients, 54% and 46% were male and female, respectively, with an average age of 17 years. The majority were transfusion-dependent (91 %), with a quarter of the patients (26%) having comorbidities, and half of the patients (52%) were from low-income families. Therefore, the medical expenses per annum for each patient of 60,000 BDT were a real burden for those patients. In the case of HRQoL, male patients showed significantly higher scores of bodily pains and physical health summaries than female patients. Lower income, high blood transfusion status, disease severity, comorbidities, and medical expenses (p < 0.05; CI 95%) are significantly associated with lower SF-36 scores. Conclusions This study found an association between lower income, blood transfusion, disease severity, comorbidities, and medical expenses and the deterioration of HRQoL among TP. Male patients experienced poorer HRQoL compared to their female counterparts. National action plans are required to guarantee the holistic welfare of thalassemia patients.

Experimental and numerical analyses are carried out to investigate the influence of twisted tape inserts on the heat transfer and the flow behavior in double tube heat exchangers. First, all the performance factors, namely the Nusselt number, friction factor, and thermal performance factor, were studied for a basic heat exchanger (BHE). Afterwards, twisted tapes with three different twist ratios (7.5, 6, and 4.5) were inserted inside the inner tube of the BHE, which resulted in three different modified heat exchangers (MHEs). For the numerical study, a 3D numerical model is developed with the k-ε RNG turbulent model to visualize the flow and the heat transfer behavior inside the heat exchangers. In both studies, turbulent flow field is maintained, ranging Reynolds number from 15000 to 50000. From the experimental result, an enhanced heat transfer, characterized by the performance factors, is found for all the MHEs compared to the BHE. The most enhanced thermal performance factor is achieved for the MHE with the lowest twist ratio. Finally, a good agreement between obtained numerical and experimental results reveals that the present numerical model can reliably predict the flow and heat transfer behavior in double tube heat exchangers.

BackgroundThis study aimed to determine the knowledge about self-management and the effects of diabetes on the daily activities among adult patients with Type 1 and Type 2 diabetes in Bangladesh.MethodologyA cross-sectional study was conducted from April to August 2021 on diabetic patients from Dhaka and the Rangpur district in Bangladesh. A structured questionnaire was used to collect data from study participants. This study’s researchers collected data via phone interview. The collected data was analyzed using Python (Version 3.8), Pandas, and ResearchPy (A Python package for research data analysis).ResultsOut of the 303 participants, all are middle-class service holders with an urban sedentary lifestyle. 69.64% and 30.3% are male and female, respectively, with 66% having post-secondary education and 35% having smoking habits. Most (68.32%) had onset of diabetic symptoms between 36-50 years, 23.43% with Type I and 41.9% with Type II diabetes. However, 34.65% of participants couldn’t answer about their ailment definitively. 22.44% of participants were on regular insulin shots within 3 months of the first diagnosis, and 90% were satisfied with managing diabetes. However, 54.46% admitted to adopting an altered lifestyle after becoming diabetic. Males and females with both types of diabetes showed significantly different comorbidities in a paired 2-tailed t-test (0.012 and 0.02 for Type I and Type II, respectively). The male participants showed higher incidences of cardiac issues, while females showed a higher propensity to hypertension. 85% of participants were confident about their medication, course of management, prognosis, diet, and lifestyle for controlling diabetes.ConclusionsThe disparity in the number of male and female participants and the high percentage of participants with no factual information about their prognosis need to be targeted for further study, and a patient-friendly engagement/ information dissemination action plan should be helpful.

This study investigates the pool boiling heat transfer of water over cylindrical heating tubes for different orientations and surface roughness of the tubes. First, two orientations of a smooth heating tube, horizontal and vertical, were used in the boiling chamber. For a given heat flux, the heat transfer coefficient achieved with the horizontal tube was always higher than that for the vertical tube. To investigate the influence of surface roughness, a rough heating tube with a fully rough outer surface was developed through a metal etching process. Under the same range of wall superheat, the rough tube enhanced the heat transfer rate significantly compared to the smooth tube. Finally, a modified heating tube (MHT) was developed by axially roughening half of the surface of an originally smooth tube. The orientation angle of the rough surface of this MHT was varied from 0° (horizontal-upward) to 180° (horizontal-downward) in the chamber. The heat flux increased significantly with the increase of orientation angles from 0° to 90° (the maximum of 80 kW/m2 at 90°), whereas the same decreased as the orientation angle is further increased from 90° to 180°. Results revealed that the bubble dynamics over the heating tubes play a vital role in pool boiling performance.

The chip shearing process is afflicted by the friction which gives rise of temperature and produces varied chip forms. For effective controlling of machining process, it is imperative to measure and optimize the chip-tool interaction parameters. In that respect, this paper presents the multi-objective optimization of some of the representative indices of chip-tool interaction in turning process using Grey relation based Taguchi method. The optimized responses are chip compression ratio (Kh), effective shear angle (βeff), friction coefficient (μ) at the tool rake surface and the chip-tool interface temperature (θ). The optimization is performed with respect to the cutting speed (vc), feed rate (f), depth of cut (ap) and cutting conditions. Two sustainable cutting conditions i.e. dry and minimum quantity lubrication (MQL) are used in the experimental runs. The objectives of this system optimization were to minimize Kh, μ, θ and maximize βeff. After optimization it was found that vc = 90 m/min, f = 0.1 mm/rev, ap = 1.5 mm and MQL cutting environment simultaneously optimized this turning system. Furthermore, Grey-Taguchi analysis revealed that the cutting speed exerts the most dominant effect, followed by feed rate, on combined grey relational grade; in other words, on the aforementioned responses. It is expected that the found optimized parameters can contribute to machining end-outcomes such as an improved surface finish, reduced tool wear and cutting force.

The global climate change challenge and the international commitment to reduce carbon emission can be addressed by improving energy conversion efficiency and adopting efficient waste heat recovery technologies. Supercritical carbon dioxide (s-CO2) cycles that offer a compact footprint and higher cycle efficiency are investigated in this study to utilize the waste heat of the exhaust gas from a marine diesel engine (Wärtsilä-18V50DF, 17.55 MW). Steady-state models of basic, recuperated, and reheated s-CO2 Brayton cycles are developed and optimized for network and thermal efficiency in Aspen Plus to simulate and compare their performances. Results show that the reheated cycle performs marginally better than the recuperated cycle accounting for the highest optimized network and thermal efficiency. For the reheated and recuperated cycle, the optimized network ranges 648–2860 kW and 628–2852 kW, respectively, while optimized thermal efficiency ranges are 15.2–36.3% and 14.8–35.6%, respectively. Besides, an energy efficiency improvement of 6.3% is achievable when the engine is integrated with an s-CO2 waste heat recovery system which is operated by flue gas with a temperature of 373 °C and mass flow rate of 28.2 kg/s, compared to the engine without a heat recovery system.

This paper demonstrates numerical simulation of In0.37 Al0.63As/In0.38Ga0.62As0.57 P0.43/In0.38Ga0.62As based lattice-matched multijunction solar cell (MJSC) in MATLAB/Simulink under AM-1.5D irradiation by assuming low resistance tunnel junction between subcells. The crucial steps of this simulation are illustrated and simulation outcomes are correlated with existing data. Band gap matching, lattice constant matching, and current matching have been checked for the selected materials in order to ensure optical transparency and topmost current conductivity into sub cells. Maximum efficiency of 37% is available from this monolithic triple junction III-V semiconductor solar cell with a short circuit current density of 12.95mA/cm 2 along with an open circuit voltage of 3.33V under 1-sun irradiation. Finally, layer thickness, doping concentration, and surface recombination velocity are optimized to achieve the best configuration of this MJSC.

In this work, a p-i-n junction type intermediate band solar cell (IBSC) model based on metal halide perovskite nanocrystals, specifically methylammonium lead iodide (MAPbI3) quantum dot (QD) and methylammonium lead bromide (MAPbBr3) barrier is designed analytically for the revolutionary next-generation photovoltaic applications. TiO2 and Spiro-OMeTAD are considered as transport layer for electron and hole, respectively. The impact of QD size and dot spacing on the key parameters of MAPbI3 QD-IBSC is illustrated by showing the wave nature of charge carriers within the QDs and their barrier. In order to identify the number of miniband in a single regime, Schrodinger equation is solved as a function of host energy gap using Kronig–Penney model. From the characteristics of electronic wave functions, it is evident that varying the QD size and interdot spacing lead to formation of more than one IB. For any case, (100)-oriented fcc crystal lattice structure is assumed. Major performance indicators of the device such as photocurrent intensity Jsc, open circuit voltage Voc, fill factor, absorbance spectra, photoluminescence (PL) intensity, external quantum efficiency (%EQE) and power conversion efficiency (PCE) η have been delineated. Highest PCE of 26.03% is attained for QD size of 5 nm and interdot spacing of 0.5 nm under one sun and AM 1.5 solar irradiation.

Here, the effect of Al x In 1-x N/GaN quantum dots in intermediate band solar cell is simulated in MATLAB by practicing Schrodinger equation as stated in Kronig-Penney model under ideal conditions. Blackbody radiation function is utilized to calculate the concentration of photon flux absorbed in the system. The device key performance parameters such as short circuit current density, J sc , open circuit voltage, V oc , and conversion efficiency, $\eta $, have been demonstrated. The relationship of IB width and IB position in host bandgap are also discussed in light of tuning QD size, dot spacing and aluminum content. Reliable performance of maximum efficiency of 55.74% are noticed when Dot size: 3.75nm, Dot spacing: 3nm and Al content: 0.27%.

The Eyewriter is an input device that uses eye gaze movement to operate a personal computer and communicate through it. From average people to the people who suffers from paralysis or born with a rare case like Tetraamelia syndrome can use this device because this device only requires eye movement. The device contains a simple arrangement that shows path to greater possibilities. The Eyewriter’s hardware consists of a very simple arrangement. Using this device anyone who is able to move their eyes can fully operate a computer and communicate with it. People who cannot talk will also have voice through this system. There are scopes for many future works for this device and the outcomes will be extremely fascinating.

A leaf spring is a simple form of spring commonly used for the suspension system in heavy duty vehicles which is originally called laminated or carriage spring. It performs the isolation task in transferring the vibration due to road irregularities to the passenger's body or goods transported on it. The advantage of leaf spring over helical spring is that the ends of the spring have been guided along a definite path as it deflect to act as a structural member in addition to an energy absorbing device. Increasing competition and innovations in the automobile sector, tends to modify the existing products with new or advanced material products. To improve the performance of the suspension system, many modifications have been taken place overtime but the recent innovations imply parabolic leaf spring and application of composite materials, as the composite materials have high strength-to-weight ratio compared to the conventional steels. The present work attempts to analyze the comparison between the conventional steel (AISI1030) leaf spring and the composite (Carbon/Epoxy) leaf spring with respect to static and fatigue analysis. Here static analysis determines the safe stress, deformation and corresponding pay load and also studies the behavior of structures under practical conditions. The research also focuses on fatigue analysis to determine its life cycle and also to observe its fatigue failure characteristics. The model of the leaf spring has been carried out into the CAD software. The analysis of the steel leaf spring has been divided into theoretical, experimental and simulation sections. The simulation of steel leaf spring has been validated with the theoretical and the experimental results. Further simulation has been done for composite leaf spring by FEA software. Finally, the result shows that the composite leaf spring has better load carrying capacity in reduced weight, and better fatigue behavior rather than the conventional steel material for the leaf spring.

A model for the prediction of the wetting delay through jet impingement quenching of a high temperature brass block has been carried out in this study. The Liquids used for jet impingement on the brass surface are water and emulsion of cutting oil (used in machine shop) and water at a proportion of 1:20.The varying parameters used for the analysis are different velocities of jet (3m/s, 5m/s, 10m/s) and initial block temperature from 250< C to 450< C at an interval of 50< C. The wetting delay and wetting front propagation varied for different test conditions. When a liquid jet was impinged on the heated surface of the brass block, the jet remains stagnant up to a small region and the surface temperature decreases very slowly with time. After a certain interval, the surface temperature decreases at faster rate and the wetting front starts to move in the radial direction. The time that passes during the stagnant period of the wetting front is the wetting delay. The wetting delay in case of emulsion of cutting fluid is much higher as compared to water. The evidence was clear for wetting delay measurement for water from graphical analysis but for the emulsion it is not as evident as in many cases the temperature drops linearly with time and the wetting delay can’t be actuated exactly. The water wave front propagates throughout the surface but in case of the emulsion the wetting front does not even cover half of the total metal surface after a long interval of time. The effect of different experimental parameters on the wetting delay is also observed in the present study. The characteristics of the wetting delay are influenced by jet velocity and initial block temperature. For higher jet velocity and lower initial block temperature wetting delay decreases.