ENERGY ABSORPTION CHARACTERISTICS OF A CARBON FIBER COMPOSITE AUTOMOBILE LOWER RAIL: A COMPARATIVE STUDY

ABSTRACT Composite materials have emerged as promising materials in applications where low weight and high strengths are desired. Aerospace industry has been using composite materials for past several decades exploiting their characteristics of high strength to weight ratio over conventional homogenous materials. To provide a wider selection of materials for design optimization, and to develop lighter and stronger vehicles, automobile industries have been exploring the use of composites for a variety of components, assemblies, and structures. Composite materials offer an attractive alternate to traditional metals as designers have greater flexibility to optimize material and structural shapes according to functional requirements. However, any automotive structure or part constructed from composite materials must meet or exceed crashworthiness standards such as Federal Motor Vehicle Safety Standard (FMVSS) 208. Therefore, for a composite structure designed to support the integrity of the automotive structure and provide impact protection, it is imperative to understand the energy absorption characteristics of the candidate composite structures. In the present study, a detailed finite element analysis is presented to evaluate the energy absorbing characteristics of a carbon fiber reinforced polymer composite lower rail, a critical impact mitigation component in automotive chassis. For purposes of comparison, the analysis is repeated with equivalent aluminum and steel lower rails. The study was conducted using ABAQUS CZone module, finite element analysis software. The rail had a cross-sectional dimension of 62 mm (for each side), length of 457.2 mm, and a wall thickness of 3.016 mm. These values were extracted from automobile chassis manufacturer's catalog. The rail was impacted by a rigid plate of mass 1 tonne (to mimic a vehicle of 1000 Kg gross weight) with an impact velocity of 35 mph (15646.4 mm/s), which is 5 mph over the FMVSS 208 standard, along its axis. The simulation results show that the composite rail crushes in a continuous manner under impact load (in contrast to a folding collapse deformation mode in aluminum and steel rails) which generates forcedisplacement curve with invariable crushing reactive force for the most part of the crushing stroke. The energy curves obtained from reactive force-displacement graphs show that the composite rail absorbs 240% and 231% more energy per unit mass as compared to aluminum and steel rails. This shows a significant performance enhancement over equivalent traditional metal (aluminum and steel) structures and suggests that composite materials in conjunction with cellular materials/configurations have a tremendous potential to improve crashworthiness of automobiles while offering opportunities of substantial weight reduction

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Does worriedness among the rural adults promote COVID-19 related awareness in Bangladesh?

People living in urban areas are usually more aware of their health issues due to the availability and accessibility of health care facilities. Several studies have illustrated anxiousness, attitudes, and perceptions among urban people during COVID-19. This research attempted to assess how worriedness among rural adults may promote COVID-19 related awareness in Bangladesh. A cross-sectional online survey of 311 respondents aged 18 or greater was conducted through Facebook focusing only on the people living in rural areas. The survey included a consent form and requested demographic as well as pandemic related information in a three-section questionnaire from the respondents. We used the chi-square test statistic for bivariate analysis and the binary logistic regression model along with some tools to validate the model to analyze the impact of worriedness on awareness. The bivariate result showed a significant association among regular hand washing knowledge about the proper amount of time for washing one's hands effectively rules of social distancing and education level with our outcome variable worriedness. From our binary logistic regression model fitting, it emerged that the females (.032, OR.729) who regularly wash their hands (0R.393, .023), know the rules of social distancing for “yes” (0R14.525, .01), and “no” groups (0R 5.518, .01), and age groups (18–27, 28 to 37, 38 to 47) were more worried. Results from our modeling justify an accuracy of 73.08%, a sensitivity of 93.71%, and a specificity of 29.33% with Cohen's kappa statistic = .2716, suggesting a fair model fitting. This study shows that the current COVID-19 situation created awareness among females and adults aged between 18 to 47 years in rural Bangladesh

Quantity-to-intensity (Q/I) relationships can efficiently characterize intensively cultivated agricultural soils in Bangladesh for better potassium supplying capacity

Aim of the study: Firstly, to evaluate the K dynamics of soils through a quantity-intensity isotherm study; and secondly, to characterize the soils on the basis of quantity-intensity (Q/I) parameters. Area of study: Gazipur, Bangladesh Material and methods: Eleven soils collected from major agro-ecological zones in Bangladesh were evaluated for their varying K dynamics parameters, and K supplying capacities of these soils were described. Main results: The Q/I plot showed both linear and polynomial relationships for soils in the study. The eleven soils had labile K ranging from 0.022 in Palashbari clay loam to 1.35 cmol kg-1 in Barisal clay. The latter soil had the highest equilibrium K activity ratio (0.003 mol L-1)1/2 and potential buffering capacity (PBC) (460.4 (cmol kg-1) (mol L-1)1/2). The PBC of soils for non-exchangeable pool (PBCne) was much higher than that of exchangeable pool (PBCe) in most soils. The largest amount of PBCne and PBCe occurred in Barisal clay, Gopalpur clay, Jhalokathi clay and Nachol loam which had a higher K desorption rate than all the other soils. The equilibrium exchangeable K, critical exchangeable K and equilibrium solution K of the soils varied widely (0.0006-0.035, 0.06-0.61 and 0.06-0.604 cmol kg-1, respectively). The added K was converted almost equally for the respective soils, with specific reference to the respective exchangeable and non-exchangeable pool for Barisal clay and Nachol loam. Research highlights: All the studied parameters revealed wide variations among the soils. The linear and polynomial relationships for soils can efficiently characterize intensively cultivated soils in Bangladesh

Impact of artificial intelligence on human loss in decision making, laziness and safety in education

Abstract This study examines the impact of artificial intelligence (AI) on loss in decision-making, laziness, and privacy concerns among university students in Pakistan and China. Like other sectors, education also adopts AI technologies to address modern-day challenges. AI investment will grow to USD 253.82 million from 2021 to 2025. However, worryingly, researchers and institutions across the globe are praising the positive role of AI but ignoring its concerns. This study is based on qualitative methodology using PLS-Smart for the data analysis. Primary data was collected from 285 students from different universities in Pakistan and China. The purposive Sampling technique was used to draw the sample from the population. The data analysis findings show that AI significantly impacts the loss of human decision-making and makes humans lazy. It also impacts security and privacy. The findings show that 68.9% of laziness in humans, 68.6% in personal privacy and security issues, and 27.7% in the loss of decision-making are due to the impact of artificial intelligence in Pakistani and Chinese society. From this, it was observed that human laziness is the most affected area due to AI. However, this study argues that significant preventive measures are necessary before implementing AI technology in education. Accepting AI without addressing the major human concerns would be like summoning the devils. Concentrating on justified designing and deploying and using AI for education is recommended to address the issue

Insight into the optimization of mass and contact time in two-stage adsorber design for malachite green removal by coconut shell activated carbon

The present work was aimed at evaluating the traits of a two-stage adsorber in optimizing the mass and contact time to achieve the desired removal performance. Data from literature for malachite green removal by coconut shell activated carbon in one-stage batch adsorber were taken as the basis for the simulation. Results show that the activated carbon mass was reduced by 22.4%, i.e., from 0.1 g to 0.078 g for 100 mL effluent, while the contact time was minimized from 30 min to 1.43 min for the removal of 50 mg/L dye in the two-stage adsorber. In the performance evaluation, the activated carbon mass in stage-1 is higher than that in stage-2 to lessen the load in accomplishing the removal at minimum dosage. The findings suggest that the two-stage adsorber design is economically viable for removing the dye in wastewater treatment

Factors influencing plasma donation behavior of COVID‐19 recovered patients in Bangladesh: A pilot study

Abstract Background and Aim The COVID‐19 pandemic has plagued our lives for more than 2 years, and the preference for convalescent plasma (CP) as a life‐saving treatment since CP has proven as a potential therapeutic option for acute COVID‐19 patients who were suffering from severe disease. It is important to identify which factors are associated with plasma donation. Therefore, this study aimed to assess the associated factors for CP donation to COVID‐19 patients. Methods A cross‐sectional study was conducted online from December 21, 2021 to February 15, 2022 to identify different socio‐demographic factors and knowledge related to CP donation. People who recovered from the COVID‐19 infections and those who are willing to participate were included in the study. A total of 60 participants were included in the study. The data were analyzed using descriptive statistics, correlation matrix, and factor analysis. Results The analysis results confirm that 41.67% (n = 25) of the participants aged 26–30 years; among the recovered patients, only about 23% (n = 14) of the participants donated plasma. Though 97% (n = 58) of the participants agreed to donate plasma when it will be needed, however, when someone asked to donate plasma then 76.67% (n = 46) of the patients declined it. Findings depict that gender had a weak positive relationship with ever decline in plasma donation at 5% level of significance and the age of the participants inversely related to plasma donation. Conclusion Almost all the recovered participants were willing to donate plasma, however, due to a lack of knowledge and misconception, relatively few people actually did. This study reemphasizes the importance of health education to overcome the misconception about plasma donation, which is crucial for the treatment of COVID‐19 infection

Bibliometric profiles of top 50 most cited articles on bioactive glass

Citation analysis of a certain publication acknowledges its impact on the scientific community. This study conducted a multivariate analysis of the top 50 most cited articles published on the field of Bioactive Glass. A systemic search was performed using the “All database” section of the Web of Science to retrieve the top 50 most cited original publications. The selected articles were then manually cross-matched with Elsevier Scopus and Google Scholar Database. Parameters such as article title, authorship, institution, country of publication, year, citation count, citation density, current citation index, and journal name were retrieved from Web of Science. Different ranges of citation numbers were retrieved for these publications in which 197-913 are from Web of Science, 209-962 are from Elsevier Scopus, and 269-1225 are from Google Scholar. A total of 153 authors contributed to this marked list, where Professor L.L. Hench contributed the highest number of articles (n=21). Imperial College London published the highest number of articles (n=21). In summary, this study provides a good scientometric picture of bioactive glass related publications, which illustrate the trend of biomaterials development over the years and suggests future scopes to the scientific community

Characterization for verification of electrostatic generator's effectiveness for power generation

Gradually usages of electric power are increasing in every country due to its easy transmission, distribution and management. Definitely, a small enhancement of the efficiency in this system will change the economy of the country. Now, electromagnetic induction is used to generate the electric power and most of the cases it is AC supply. However, electrostatic induction can also be used to generate the electric power; but the drawback of this system is, it can generate power in high voltage DC (HVDC) supply only. Another unruly matter is, the HVDC can easily damage the conducting material due to high voltage electrical arc discharging and break down the insulation materials. The challenging task of this research is to find a suitable and sustainable system to transform the HVDC into AC supply. Tremendous progress of the material science and electronic devices make it easy to convert the electric power supply from the DC to AC using inverters and switching circuits. Once the electric power supply converted into AC from the DC, the next steps are as usual and it does not need to modify the existing electrical system anymore. The magnetic and electric fields are different in nature, thus their field drags are also different. Moreover, the magnetic induction type generator is heavier, therefore, it imposes large force of static inertia and frictional loss compared to the electrostatic generator. The research is to characterize, study the HVDC inverter, examine the electric power generation efficiency of the electrostatic generator. It is also to carry out a texts survey to find out the scope of uses of the electrostatic generator and HVDC in Malaysia based on the characterization and efficiency of the electrostatic generator. Consequently, a simple, high efficiency and low cost as well as an economic electric power generation are expected to achieve. A large amount of energy is used directly in the form of electric power in every country around the world, due to its easy transmission, distribution and management. Moreover, it is environment friendly. Undoubtedly, a small amount improvement of efficiency in this system can radically change the economy of the world. Nowadays, electromagnetic induction is used to generate the electric power and most of the cases it is in the form of alternating current (AC). However, electrostatic induction can also be used to generate the electric power, but the drawback of this system is, it can generate the power in the form of direct current (DC) only. As a result, it uses are limited within some special applications and research only. It is possible to overcome this shortcoming of the system by converting the DC into AC supply. Another unruly matter is, the high voltage can easily damage the conducting material due to high voltage electrical arc discharge and break down the insulation materials. As a result, to make a sustainable system it needs special materials and equipment. Now, there is a tremendous progress of the material science and electronic devices that make it easy to convert the electric power supply from the DC to AC or vice versa. Therefore, electric power can easily be controlled with the aid of electronic circuits. Once the electric power supply converted into AC from the DC which is generated from the electrostatic generator, the next steps are as usual and it is no longer needed to modify the existing electrical system. However, the challenging task of this research is to find a suitable and sustainable system to transform the DC high voltage into AC supply. Since, the magnetic and electric fields are different in nature, their fields drag are also different. Moreover, the magnetic induction type generator is heavier than the electrostatic generator, as a result, the magnetic induction type generator imposes large force of static inertia and frictional loss compare to the electrostatic generator. The aims of this research are to characterize the electrostatic induction generator, to study the high voltage DC to AC inverter for electrostatic induction type generator, to examine the electric power generation efficiency of the electromagnetic induction and electrostatic induction type generators. It is also to carry out a text survey to propose the scope of uses of the electrostatic generator and HVDC in Malaysia based on the characterization and efficiency of the electrostatic generator obtained

UNVEILING THE NATURE OF CARBON DECOMPOSITION ON DIFFERENT ORGANIC MANURE SOURCES: THE IMPACT OF TEMPERATURE REGIMES IN A SUBTROPICAL CLIMATE

Organic sources are vital for crop nutrient management, but nutrient release from organic manure depends on temperature and other factors. We conducted a laboratory incubation study to investigate how temperature (15, 25, 35°C) affects the decomposition of common organic manure, which has not yet been explored in Bangladesh. The organic manures used in this study are poultry manure (PM), vermicompost (VC), bio-slurry (BS), cow dung (CD), water hyacinth compost (WHC) and rice straw compost (RSC), which were compared with a control treatment (only soil). Carbon mineralisation and CO2 emission from microbial respiration varied among organic manures and temperature regimes. The RSC- and WHC-treated soils had a higher C mineralisation than the other manures at 35°C. The mineralisation of C among the organic manures followed the order: RSC > WHC > CD > VC > BS > PM > control. Among the temperature regimes, C mineralisation followed the order 35°C > 25°C > 15°C. Manure mineralisation was associated with mineralisable C pools (carbon availability factor, Caf), and 16.4–36.5% organic C was released. Irrespective of temperature regimes, the highest easily mineralisable Caf was recorded in PM-amended soil, followed by VC-amended soil. RSC had the lowest Caf under all temperature regimes. The Caf values of all incubated manures were higher under a 35°C temperature regime. Compost preparation from organic manure and its utilisation as an integrated nutrient management component can play essential roles in mitigating climate change, reducing environmental degradation, and building more sustainable and resilient agrifood systems