Search

Lower alcohols have long been the figureheads of diesel/biodiesel additives in characterizing renewable fuels. Next-generation alcohol like n-octanol occupied the reified position due to their better fuel properties. In this paper, combustion, performance and, emission of different graphene-oxide nanoparticles (nanoGO) added jatropha biodiesel, n-octanol and petrodiesel blends are investigated in a 4-stroke DI diesel engine. This article also aims to optimize the engine inputs accountable for better performance and emission characteristics of a diesel engine running with nanoGO dispersed biodiesel/diesel/higher alcohol blends. Full Factorial Design-based Response Surface Methodology (RSM) is utilized to model the experiments using Design-Expert software to optimize engine responses. Validation of the developed model is carried out using sophisticated error and performance metrics, namely, TheilU2, Kling-Gupta Efficiency (K-G Eff), and Nash-Sutcliffe coefficient of efficiency (N-S Eff) along with the conventional statistical database. The model optimized engine inputs of 3.898% n-Octanol, and 49.772 ppm nanoGO at 99.2% load with a desirability index of 0.997 as the optimum engine parameters. The experimental validation revealed that the model optimized blend at full load witnessed a reduction of 15.6% CO, 21.78% HC.u, and 3.26% NOx emission compared to petrodiesel. However, a slight increase in brake specific energy consumption (2.95%) is also recorded because of the lower heating value of the blend.

Application of reinforced composite material enhanced in recent days compared to earlier conventional material due to its specific strength, high hardness, less weight, and better wear performance capacity. This paper deals with the wear resistance behaviour of different weight percentages of SiC particles dispersed aluminium matrix composites fabricated by stir casting. Scanning Electron Microscope (SEM) analysis revealed that uniform distribution of SiC particulates throughout the aluminium matrix. Wear analysis of formed composite was evaluated by using Taguchi L16 orthogonal array to minimize the total number of experimental runs. In order to obtain an efficient wear rate, four major factors such as reinforcement quantity (3, 5, 7 and 9%), applied load (10, 20, 30 and 40 N), sliding velocity (0.5, 1, 1.5 and 2 m/s) and sliding distance (500, 1000, 1500 and 2000 m) were varied four various levels. Analysis of Variance (ANOVA) result revealed that the probability value of the applied load was lesser than 0.05 that expressed the factor of significance. In this work, maximum Grey Relational Grade (GRG) and Grey Fuzzy Grade (GFG) results are observed 0.798 and 0.772 respectively to optimized factors of 9 wt.% SiC reinforcement, 10 N applied load, 2 m/s sliding velocity and 500 m sliding distance. It is concluded that the grey-fuzzy approach significantly strengthens the decision making of tribological behaviour instead of a simple grey relational grade.

The advancement in technologies and increased risk in treating intracranial aneurysms have created the need for the advancement of new surgical instruments which would reduce the risk of high traumatic surgeries. These aneurysms are being treated by catheterization procedures in sensitive organs like the brain and heart. The best surgical instrument for treating these vascular diseases through catheterization is microcatheter which can navigate through the narrow complex vasculature. Microcatheters are especially used in the case of the brain because of their small size cross-section that can convey liquid embolic agent and solid embolic coils to the target diseased vessel. This study presents the design of a single lumen microcatheter with a single-coil having a straight distal tip towards the distal end. The finite element analysis of the modeled microcatheter is done to determine the minimum deformation of the device so that it can be used for the medical purpose. The microcatheter is designed in a three-dimensional modeling software i.e. CATIA V5 R21 Software and the analysis of it (designed model) is done using ANSYS. The main aim of this study is to design an ease trackability microcatheter for easy perambulation inside the vessels.

Technological advances have revolutionized the healthcare in the last few decades. Recent methods of treatment focus on minimal invasive techniques like laparoscopic or robotic assisted surgery etc. Endovascular treatment is one such minimal invasive method carried inside blood vessel using small flexible tubes called microcatheter. Many types of procedures like opening of a blocked artery (angioplasty) blocking a bleeding artery (embolization), treating abnormally developed blood vessel (AVM) is carried out using microcatheter. To meet these various needs, the micro catheter’s design has been modified from a simple tube to complex structure. The ideal microcatheter should be strong, flexible, trackable and steerable. The existing design is not able meet all the characteristics. Recently emphasis is given on catheter design for better maneuverability. Indigenous research and improvised designs are contemplated by some great minds working unanimously around the world. The review deals with the implementation of micro sensing devices to control the bending characteristics in the microcatheter for an efficacious passage in the tortuous vasculature. Actuators like-polymer conducting layers, pressure sensors, CMOS circuits etc. are used to perceive an exceptional control method for precise bending of the layers. Artificial Intelligence (AI) and deep learning techniques are some potential techniques that can be used for optimized results and accurate control methods.

Topological photonics provides a new platform to control and manipulate the flow of light in photonic devices that exhibit topological phase transitions. One way to introduce such transition of geometric phases in photonic waveguides is to modulate the structure of the photonic crystals, array waveguides, or the metamaterials in such a way that it eventually changes the bulk topology. Such topological waveguides localize the light at the boundary of the two distinct bulk systems with different topological invariant. Based on this fundamental physics, we demonstrate a robust and controlled propagation of light in a class of specialty optical fiber which exhibits the topological phase transition between a nontrivial one-dimensional (1D) periodic cylinder and its topologically trivial counterpart. The key idea is to explore the possibility of topological phase transition of 1D photonic bands over the momentum space by tuning the unit-cell dimension and its individual thicknesses. We have systematically computed the trivial and the nontrivial topological invariants, the Zak phase, of designed cylindrical 1D lattices with inversion symmetry over the first Brillouin zone. To establish the presence and the robustness of the localized edge mode, we have studied the reflectance of the geometry in the presence of disorder. Also, the simulated field profile and the back-reflectionless propagation of the edge mode through the fiber have been shown. Besides conventional fibers, such topological optical fibers are definitely a waveguide geometry for robust delivery of light and thus would be very significant to open up a new paradigm in guided wave photonics.

The issue of environmental pollution and the depletion of fossil fuel are nowadays a major field of attention for the modern world. In substitution of petroleum-based diesel, biodiesel and ethanol have been explored in many studies. In this paper, diesel-palm biodiesel-ethanol has been used together at different proportion to execute performanceemission characteristics and their trade-off study at different brake power. An experimental investigation is carried out for different diesel-palm biodiesel-ethanol blends ranging by volume of 5-10% ethanol, 5-25% biodiesel and 65-90% baseline diesel. From the experimental results, comparatively, low brake specific fuel consumption (BSEC) has been observed for all 5% ethanol-blended fuels. Maximum reduction in BSEC has been observed 1.9, 2, and 3.24 % at 0.68, 2.05, and 3.42 kW respectively. At medium to high load, brake thermal efficiency (BTE) has been found higher for lower ethanol fraction. As compared to diesel, the highest nitrogen oxide (NOx) reduction have been found 13.7, 9.17, and 4.7 % at 0.68, 2.05, and 3.42 kW respectively. At last, performance-emission trade-off shows that D70B25E5 blend has a higher BTE with maximum reduction in unburnt hydrocarbon (UHC) and NOx emissions.

With the prevalent interest in diesel engine performance and emission, it is necessary to define optimum engine operating condition with less number of experiments for the efficient and eff...

This paper investigates the consequence of linseed methyl ester and diethyl ether on the performance and emissions of the existing single cylinder compression ignition engine. Here biodiesel is mix...

We report an Aubrey-Andre-Harper (AAH) model based quasi-periodic lossless evanescently coupled waveguide lattice to study the unconventional physics of light localization. We find an exclusively new way to establish localization phase transition in a 1D-AAH lattice by observing the slope variation of the band and accordingly study the modal characteristics to reveal the fact that a higher value of quasi-periodic modulation strength is imperative for observing a signature of fully localized light states having higher eigenenergy. This analytical concept has numerically been implemented in the proposed quasi-periodic lattice to achieve light localization, where we have shown that the supported states not only depend on localization phase transition parameter, but also on the specific location of excitation which is due to quasi-periodic nature of lattice. Furthermore, we have investigated a unique effect of the presence of disorder on light localization phenomenon, where it has been reported that the presence of off-diagonal disorder, which is otherwise detrimental, favours light localization in the proposed structure due to its quasi-periodic nature. The findings indeed have the potential to open up a fertile platform to manipulate light in passive photonic devices.

We present a quasi-periodically modulated coupled multicore fiber based on Aubry-Andre- Harper model to exhibit a sharp localization phase transition that is explicitly dependent on modulation strength and core arrangement radius of the geometry.

Major limitation of planar (microstrip) antenna is its inability to provide omni-directional radiation patterns. Base station trans-receiver antennas for mobile communication require omni-directional radiation patterns. In this report an efficient four looped modified and reactively loaded clover arranged omni-directional polarization agile (circularly polarized in lower band an d dual polarized in higher band) wire antenna has been presented for dual band viz. mobile communication and WiMAX frequency operations.

This paper investigates the normal stress and shear strain of a single lumen microcatheter. A microcatheter is a nominally invasive device used in intracranial and neurovascular therapeutic disorders. Finite element method is used to analyze the stress-strain variations in all the three layers of the microcatheter. The stress-strain distributions are studied to incorporate an efficient and robust design to improve tractability of the microcatheter. The main objective of this paper is to make the microcatheter cost effective for the society by employing a robust design. A novel design of the microcatheter is done using a high-end three-dimensional modelling software inhibiting bends along the length to determine the failure criterion in one or all the three layers. The design of the braiding can be re-calibrated such that it can avoid shear failure of the inner layer. The dorsal tip of the microcatheter can be programmed using artificial intelligence using smart alloys (SMA) on the inner surface so it can take any shape according to the pathway inside the body.

Aquaculture and fisheries continues to be a sector that has not received adequate attention for its contribution to food security goals across the globe. This sector is predicted to grow at a fast rate in the next 40 years. In the Indian context, the government has prioritized the aquaculture and fisheries sector by establishing an independent federal ministry. However, the public extension system in India still lacks resources and strategies to address the needs of fish farmers and fishers. This has created a space for the private extension system to play a pivotal role in providing appropriate skills and training to farmers and fishers. Considering the present challenges in the aquaculture and fisheries sector, this paper proposes the creation of an Aqua-Chamber of Commerce (ACC) as a viable bottom-up approach to improve the performance of the sector by providing adequate support to private extension system. Additionaly, the ACC will also help in improving the public extension system, facilitating the business ecosystem and strategies, and advocating for major policy reforms in the sector.

This present investigation focuses on combustion-performance-emission characteristics of cerium oxide (CeO2) added palm biodiesel blends in a single cylinder diesel engine. Experiments are conducted in a natural aspirated single cylinder diesel engine at constant speed and varying load (low, medium and full). The experimental result reveals that the addition of CeO2 nanoparticles (50, 100, and 150 ppm) to palm biodiesel blends enhanced brake thermal efficiency (BTE) with reduction in brake specific energy consumption (BSEC) due to improved ignition characteristics of the modified blends. Maximum reduction of CO, HC and NOx emissions have been observed 50, 48.45, and 11.1% at full load respectively. Later on, friction and wear study has been conducted to investigate tribological behavior of cylinder liner-piston materials under lubrication (using contaminated lubricant). The whole friction and wear study has been performed on pin-on-disc tribometer at different speed (300, 400, and 500 rpm) and load (10, 30, and 50 N). The dilution of CeO2 added biodiesel blends with the lubricant resulted low coefficient of friction (COF) and specific wear rate. At varying speed of 300, 400, and 500 rpm: 6.07, 8.5, and 10.9%; and at varying load of 10, 30, and 50 N: 6.07, 10.96, and 11.77% lower average COF have been observed respectively for nanofuels contaminated lubricant compared to diesel contaminated lubricant. Similarly, 7.94, 30, & 28.06% and 7.94, 30.33, & 17.04% lower specific wear rate at varying speed and load have been observed respectively for nanofuels contaminated lubricant.

Objective: To investigate an anthrax outbreak affecting multi-species of animals including human in five remote tribal villages in West Midnapur district, India, with no previous history of anthrax cases for decades. Methods: A systematic epidemiological investigation, along with bacteriological examination, cultural isolation, biochemical and molecular characterization of the samples (blood, dried meat, pieces of bones) was carried out to con firm diagnosis, identify transmission routes and risk factors to recommend suitable control measures. Results: Samples from nine animals were confirmed for presence of Bacillus anthracis by characteristic morphology, biochemical profile, McFadyean reaction in blood smear, ‘medusa head’ appearance of colonies and PCR based detection of pXO1 plasmid. Epidemiological investigation revealed that the human patients contracted the infection during butchering or while handling contaminated animal products. In total, 14 animals died and 11 people got infected with cutaneous anthrax during the outbreak period. Conclusions: Anthrax continues to be a persisting problem in Indian subcontinent causing considerable morbidity and mortality in animals and human. Collaborative efforts of human and animal health officials through various controlled measures viz., ring vaccination, early treatment of human cases, quarantine of affected animals, safe disposal of carcass and public health campaign effectively controlled the zoonotic anthrax outbreak.

Radar Reflectivity measurement for weather monitoring is a well known approach for scientists all over the world. In this paper a Yagi-Uda antenna is designed and experimentally verified intended to be used for weather monitoring applications. The antenna is further used as an element of planar array designed and simulated for gain enhancement required for atmospheric applications.

This present investigation focuses on prediction of engine responses of a single cylinder CI engine powered by bio-diesohol (diesel-palm biodiesel-ethanol) blends using RSM (response surface methodology) and ANN (artificial neural network) model. RSM combined with multi-level general full factorial design (FFD) is used for the prediction of brake thermal efficiency (BTE), brake specific fuel consumption (BSEC), and nitrogen oxides (NOx). The engine experimental data is trained in ANN model using Levenberg-Marquardt back propagation training algorithm with logistic-sigmoid activation function. Different statistical measures are calculated to quantify the errors and correlations of the predicted models. Comparatively lower prediction error and higher correlation have been observed from the ANN model compared to RSM. The range of overall mean square error (MSE) and correlation coefficient are found (0.0003–0.00059) & (0.99403–0.998) and (0.00019–0.00035) & (0.99943–0.99971) from RSM and ANN model respectively. The range of overall mean absolute percentage error (MAPE) from ANN model (3.13–4.55%) is found lower compared to RSM model (3.97–6.6%). Thereafter, RSM and ANN predicted responses are introduced in fuzzy logic system for the optimization of engine operating parameters. At 100% load, the D75B20E5 (75% diesel + 20% palm biodiesel + 5% ethanol) blend has been found best for the optimization of BTE, BSEC and NOx emission. Finally, after the confirmation test, it has been revealed that the performance of D75B20E5 blend is as comparable to diesel.

The growing concern over the dependency on fossil fuel has prompted the cost of energy supply to the high extent. Widespread application of fossil fuel in transportation and electricity generation has steadily declined the fossil fuel supply along with the provoked environmental pollution. Strict environmental concern, depletion and price hike of fossil fuel has driven scientific study for the search of alternative fuels. To address the difficulties of fossil fuel, alternative fuels could be a fruitful substitute for global emission reduction. Where biodiesel makes itself as one of the best available resources due to its vast applicability in diesel engine. Among other biodiesels, palm biodiesel has proved itself as a most dominating biofuel due to its highest contribution worldwide (35%), minimum price (660 USD/ton), maximum oil content (5000 kg oil/ha), and production yield (4.2 MT/ha). The worldwide palm oil market progressively growing and it is expected to reach a market value of US$92.84 billion in 2021. The aim of this paper is to address different aspects of palm biodiesel for the potential solution of future renewable fuel. This paper describes a detailed review on palm biodiesel as a notable alternative in respect to the economy, environment, and efficiency. A thorough production process, properties, advantages, disadvantages, and the global economy of palm biodiesel are discussed. This article also deals with the sustainability, social, and environmental impact of leading palm oil producers like Malaysia, Indonesia, and Thailand. In this article, diesel engine combustion using palm biodiesel and its effect on engine efficiency and environmental pollution (due to engine emissions) are also reviewed. The scope of the present study relies on the brief description of the development and challenges of palm biodiesel feedstock for the continuation in the coming future.

Corporate Governance (CG) largely determines how well the interests of the stakeholders are being maintained. This study has been opted for in-depth inquiry into the corporate governance disclosure practices in the annual reports of the selected listed banking companies in Bangladesh. The study finds that all the sample companies disclose corporate governance information as per regulatory requirements laid down in Clause 1.5 of the SEC Notification, 2012. The focus of this study was to empirically examine the mandatory corporate governance disclosure and the relationship between various corporate attributes and with the level of that mandatory disclosure of the banking companies of Bangladesh. The study revealed that Bangladeshi banking companies have high level of compliance to the mandatory corporate governance disclosure and the variables of board size, ownership, board composition, and profitability have significant impact in the corporate governance disclosure. However, the inclusion of the separate section of Corporate Governance Reporting in the annual reports and suggested guidelines for mandatory list of items to be included in the report is a milestone for Bangladesh. For the purpose, the study has developed a questionnaire based on recent literature survey and have gathered the opinions of the executives of three sample banks under the framework of likerts 5 point scale. The gathered primary data have been properly analysis by a number of descriptive statistics, such as, Mean, Standard Deviation, ANOVA and Post hoc multiple comparison tests.

This paper investigates use of artificial neural network (ANN) model in prediction of brake specific energy consumption (BSEC), nitrogen oxides (NOx), unburnt hydrocarbon (UHC), and carbon dioxide (CO2) emissions of a single cylinder diesel engine operates with diesel-palm biodiesel-ethanol blends. The engine is run at different load form 20–100% and 1500 rpm constant speed. The fuel used in this present study are diesel and six different diesel-palm biodiesel-ethanol blends. The Levenberg-Marquardt back propagation training algorithm with logistic-sigmoid activation function results best prediction of performance and emission characteristics with accurate overall correlation coefficient (R) (0.99329–0.99875) and minimum mean square error (MSE) (0.000179082–0.000465809). The mean absolute percentage errors (MAPE) are observed to be in range of 2.32–4.54% with the acceptable margin of mean square relative error (MSRE). Furthermore, experimental and ANN predicted data are compared in fuzzy interface system (FIS) to find optimum engine operating parameters. Compared to other blends, at 20% load, D85BD10E5 blend exhibits the highest MPCI (multi performance characteristics index) values of 0.718 and 0.705 for experimental and ANN predicted data respectively. Robustness and reliability of the proposed techniques clearly explain the application of ANN and fuzzy logic system in the prediction and optimization of engine parameters.

The present world faces the crisis of fossil fuels as it will no longer sustain in the future, gives a knowledge to look on waste resources, where waste rice and neem seed are utilizable for the production of biofuels by the process of fermentation and transesterification. In this paper, the physiochemical properties of the produced biofuels are examined. The 5% rice wine alcohol is used as an additive with neem methyl ester-diesel blend to lower the viscosity and flash point for the better performance in the single cylinder compression ignition engine. Different blends as D90B5RW5, D85B10RW5, D75B20RW5, and D65B30RW5 are prepared and examined experimentally by varying the engine loads (0–100%) at constant engine speed (1500 rpm). Experimental results showed the reduction of carbon dioxide (CO2), carbon monoxide (CO), hydrocarbon (HC) and smoke opacity, however oxide of nitrogen (NOx) is found higher. In the performance, D75B20RW5 shows 8% higher brake thermal efficiency and 3.33% lower brake specific fuel consumption compared to diesel. While in the combustion the peak cylinder pressure and net heat release rate are seen to be higher for biodiesel blends with additive.

Background and Aims: Remdesivir is identified as an effective therapeutic option in COVID-19, but its’ hepatic safety has not been well studied. So, we aimed to identify the pattern and severity of hepatotoxicity in remdesivir treated COVID-19 patients. Methods: This cross-sectional study was carried out at a dedicated COVID-19 unit of a university hospital in Dhaka, Bangladesh among severe COVID-19 cases. Alterations of liver functions were compared between the remdesivir and the non-remdesivir treated patients. Results: Out of 50 severe COVID-19 cases 25 had received remdesivir and 25 had received other supportive care without remdesivir. Median serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were significantly higher in the remdesivir treated arm (p-value for AST 1.5 in the remdesivir treated arm. Conclusion: Many of the patients with severe COVID-19 had mild to moderate aminotransferases elevation. If the elevation of liver enzymes occurs after the initiation of remdesivir, adverse drug reactions need to be considered and drug discontinuation may require if severe elevation occurs.

External Debt (ED) is considered as a significant source of income for developing countries. Bangladesh relied on foreign debt to finance its balance of payments deficit and saving investment gap. Primary objective of this paper is to explore the relationship between external debt and Gross Domestic Products in Bangladesh for the period of 1972-2010, using time series econometric technique. We took a point of glance of external debt and economic performance of Bangladesh. The results show that there is a positive significant correlation between Gross Domestic Products (GDP) and External Debt (ED). The empirical results suggest the existence of long-run relationship between GDP and ED. The result of Granger’s Causality test implies that there is bi-directional causality runs through GDP to ED as well as ED to GDP.