Performance Analysis of 2.5 Gbps PIN and APD Photodiodes to Use in Free Space Optical Communication Link

Ever since ancient times, people had a principle need to communicate with one another. This need created interests in device based communication system for sending messages from one distant place to another. Optical communication methods were of special interest among the many systems. In this paper, investigation has been done on two different photodiodes PIN and APD for use as a receiver in free space fiber optical link. We have considered 2.5 Gbps PIN and APD photo diodes for our experiment. From the simulation, we found that APD with single mode fiber gives the better performance over PIN. However, the value of Q-factor is maximum when APD has been used as the receiving photodiode at 1550nm wavelength and minimum when PIN diode has been used as receiving photodiode at 1550nm wavelength. We used OptiSystem and MATLAB software for our investigatio

Macroeconomic Forces and Stock Prices:Evidence from the Bangladesh Stock Market

The study examines the influence of a selective set of macroeconomic forces on stock market prices in Bangladesh. The Dhaka Stock Exchange All-Share Price Index (DSI) is used to represent the prices in the stock market while deposit interest rates, exchange rates, consumer price index (CPI), crude oil prices and broad money supply (M2) are selected to represent the macroeconomic variables affecting the stock prices. Using monthly data from 1992m1-2011m6, several time-series techniques were used which include Cointegration, Vector Error Correction Model (VECM), Impulse Response Functions (IRF) and Variance Decompositions (VDC). Cointegration analysis, along with the VECM, suggests that interest rates, crude oil prices and money supply are positively related to stock prices, exchange rates are negatively related to stock prices, and CPI is insignificant in influencing the stock prices, in the long-run. Both the IRF and VDC suggest that shocks to macroeconomic variables explain a small proportion of the forecast variance error of the DSI, but these effects persist for a long period

Macroeconomic Forces and Stock Prices:Evidence from the Bangladesh Stock Market

The study examines the influence of a selective set of macroeconomic forces on stock market prices in Bangladesh. The Dhaka Stock Exchange All-Share Price Index (DSI) is used to represent the prices in the stock market while deposit interest rates, exchange rates, consumer price index (CPI), crude oil prices and broad money supply (M2) are selected to represent the macroeconomic variables affecting the stock prices. Using monthly data from 1992m1-2011m6, several time-series techniques were used which include Cointegration, Vector Error Correction Model (VECM), Impulse Response Functions (IRF) and Variance Decompositions (VDC). Cointegration analysis, along with the VECM, suggests that interest rates, crude oil prices and money supply are positively related to stock prices, exchange rates are negatively related to stock prices, and CPI is insignificant in influencing the stock prices, in the long-run. Both the IRF and VDC suggest that shocks to macroeconomic variables explain a small proportion of the forecast variance error of the DSI, but these effects persist for a long period

Mechanical and Thermal Properties of Graphene over Composite Materials: A Technical Review

The recent years have seen numerous developments in the research and headway of graphene, the thinnest two-dimensional nuclear material. Graphene-based materials and their composites have promising applications in an extensive variety of fields; for example, gadgets, biomedical guides, films, adaptable wearable sensors, and actuators. The most recent investigations and movement in this branch of knowledge regularly deliver conflicting or uncertain outcomes. This article evaluates and outlines the distributed information in order to give a basic and complete diagram of the cutting edge. Initially, the particular basic nature of accessible graphene materials is illustrated as well as the distinctive generation methods accessible thus far. The appraisal at that point talks about the different composites that center diverse sub-practical routines; for example, mechanical and aggregate utilitarian applications (e.g., vitality, hardware biomedical, layers, and sensors). The use of graphene and its subsidiaries in the fabricate of nanocomposites with various polymer frameworks has been inspected. And finally, an ending and point of view are given to talking about the rest of the difficulties for graphene nanocomposites in useful science and building

The importance of community health workers as frontline responders during the COVID-19 pandemic, Somalia, 2020–2021

IntroductionWe examined the contribution of community health workers as frontline responders for the community-based surveillance in Somalia during the first year of the COVID-19 pandemic for detection of COVID-19 cases and identification of contacts.MethodsWe retrieved COVID-19 surveillance data from 16 March 2020 to 31 March 2021 from the health ministry’s central database. These data were collected through community health workers, health facilities or at the points of entry. We compared the number of suspected COVID-19 cases detected by the three surveillance systems and the proportion that tested positive using the chi-squared test. We used logistic regression analysis to assess association between COVID-19 infection and selected variables.ResultsDuring the study period, 154,004 suspected cases of COVID-19 were detected and tested, of which 10,182 (6.6%) were positive. Of the notified cases, 32.7% were identified through the community-based surveillance system, 54.0% through the facility-based surveillance system, and 13.2% at points of entry. The positivity rate of cases detected by the community health workers was higher than that among those detected at health facilities (8.6% versus 6.4%; p < 0.001). The community health workers also identified more contacts than those identified through the facility-based surveillance (13,279 versus 1,937; p < 0.001). The odds of COVID-19 detection generally increased by age. Community-based surveillance and health facility-based surveillance had similar odds of detecting COVID-19 cases compared with the points-of-entry surveillance (aOR: 7.0 (95% CI: 6.4, 7.8) and aOR: 7.5 (95% CI: 6.8, 8.3), respectively).ConclusionThe community health workers proved their value as first responders to COVID-19. They can be effective in countries with weak health systems for targeted community surveillance in rural and remote areas which are not covered by the facility-based surveillance system

The impact of the COVID-19 pandemic on the education of medical, dental and non-medical healthcare professionals in Bangladesh : findings and connotation

Lockdown measures in response to the COVID-19 pandemic had an appreciable impact on the education of all medical, dental, and non-medical healthcare professional (HCP) students. These included the closure of universities necessitating a rapid move to e-learning and new approaches to practical’s. However initially, there was a lack of knowledge and expertise regarding e-learning approaches and the affordability of internet bundles and equipment. We initially con-ducted two pilot studies to assess such current challenges, replaced by a two-stage approach including a full investigation involving 32 private and public universities during the early stages of the pandemic followed by a later study assessing the current environment brought about by the forced changes. Top challenges at the start of the pandemic included a lack of familiarity with e-learning approaches, cost of the internet, lack of IT equipment and the quality of the classes. Universities offered support to staff and students to a varying degree to address identified challenges. Since then, e-learning approaches have widened the possibilities for teaching and learning at convenient times. However, challenges remain. In conclusion, there were considerable challenges at the start of them pandemic. Several key issues have been addressed with hybrid learning here to stay. Remaining challenges include a lack of ICT equipment. However, new innovations will continue

Municipal Solid Waste Management and Waste-to-Energy Potential from Rajshahi City Corporation in Bangladesh

Waste management is becoming one of the most challenging tasks for developing countries in order to ensure good human health, as well as a healthy environment. Rajshahi City Corporation (RCC) is one of the 12 city corporations in Bangladesh. Various environmental and human health problems have arisen due to a lack of proper knowledge of waste management. Thus, the aim of this work is to illustrate the present status of MSW generation and management in Rajshahi City Corporation, Bangladesh. Fifty households were selected throughout RCC for waste collection, which represent approximately all types of households in RCC. From the qualitative and quantitative analysis, it is estimated that the approximate MSW generation in RCC is 358.19 t/d (tons/day) at an approximate rate of 0.4214 kg/person/d. Calorific values of the wastes have also been determined using the ultimate analysis results of the MSW. A higher calorific value of the dry MSW has been calculated as 14.9 MJ/kg. Moisture content of the MSW has been found to be 48.28%. It is also estimated that the possible power generation (steam energy to electrical power) from MSW generated in RCC is 159.40 MWh/d. Lastly, future scopes of MSW management and different waste management measures that need to be taken are illustrated. Waste-to-energy (WTE) conversion has been given priority and anaerobic digestion (AD) has been found to be an interesting prospect in this sector. Techno-economic analysis of the AD has been conducted. Energy potential from the proposed plant has been calculated as 3.85 MW and the payback period has been found to be 4.9 years. It has been observed that employing AD on a large scale can not only reduce the waste, but also meet a large portion of the energy demand of this city