Are mega-events super spreaders of infectious diseases similar to COVID-19? A look into Tokyo 2020 Olympics and Paralympics to improve preparedness of next international events.

Tokyo Summer Olympics and Paralympics have raised social issues regarding the potential rise in COVID-19 cases in Japan and risks associated with the safe organization of mega sporting events during the pandemic, such as the FIFA World Cup Qatar 2022. This study investigates the Tokyo Summer Olympics as a unique case study to clarify the drivers of infectivity and provide guidelines to host countries for the safe organization of subsequent international sporting events. The result here reveals that Tokyo and Japan did not experience a rise in confirmed cases of COVID-19 due to the hosting of the Summer Olympics. Still, transmission dynamics seems to be mainly driven by the high density of population (about 1.2%, p-value <0.001) like other larger cities in Japan (result confirmed with Mann-Whitney U test, significance at 0.05). Our study provided evidence that hosting mega sporting events during this COVID-19 pandemic is safe if strictly maintained the precautions with non-pharmaceutical (and pharmaceutical) measures of control of infections. The Tokyo Summer Olympics hosting will be exemplary for next international events due to the successful implementation of preventive measures during COVID-19 pandemic crisis.

A simulation study of techno-economics and resilience of the solar PV irrigation system against grid outages.

Water is the most fundamental need for better yield in agriculture. Worldwide, diesel and electricity are typically used to pump water which contributes to atmospheric pollution. Besides, a power outage affects the irrigation process badly. Without water, the crop may wither away, causing a substantial economic loss. This paper discusses the resilience of a solar PV system during a power outage. HOMER Pro software was used to perform the techno-economic analysis of solar-based irrigation for four major divisions of Bangladesh, while 1-hour power outage was assigned in REopt lite to model the survivability of the system against the grid outage. The simulation outcomes showed that the energy cost is $0.1496/kWh, $0.1502/kWh, $0.1557/kWh, and $0.1576/kWh for Rajshahi, Sylhet, Dhaka, and Chattogram, respectively. About 45% of excess electricity can be stored after fulfilling all requirements. The system is more economical than a microgrid-based water pumping system and a diesel-based system, and the photovoltaic system is technically and economically suitable to pump water if the nearest grid connection is impossible. When connected to the main utility grid, the system can survive without grid power for several hours, subject to daytime outages.

Estimation of the healthcare waste generation during COVID-19 pandemic in Bangladesh.

COVID-19 pandemic-borne wastes imposed a severe threat to human lives as well as the total environment. Improper handling of these wastes increases the possibility of future transmission. Therefore, immediate actions are required from both local and international authorities to mitigate the amount of waste generation and ensure proper disposal of these wastes, especially for low-income and developing countries where solid waste management is challenging. In this study, an attempt is made to estimate healthcare waste generated during the COVID-19 pandemic in Bangladesh. This study includes infected, ICU, deceased, isolated and quarantined patients as the primary sources of medical waste. Results showed that COVID-19 medical waste from these patients was 658.08 tons in March 2020 and increased to 16,164.74 tons in April 2021. A top portion of these wastes was generated from infected and quarantined patients. Based on survey data, approximate daily usage of face masks and hand gloves is also determined. Probable waste generation from COVID-19 confirmatory tests and vaccination has been simulated. Finally, several guidelines are provided to ensure the country's proper disposal and management of COVID-related wastes.

Energy, emission, profitability, and sustainability analyses of a grid-connected solar power plant proposed in airport sites of Bangladesh: a case study.

Nowadays, the aviation industry is one of the significant contributors to greenhouse gas emissions. An optimum solution to this concern is the substitution of conventional electricity consumption with clean energy sources. Barren lands are available in airport sites as buffer zones. These lands can be utilized to generate electricity from clean energy sources like solar, wind, and others. This study proposed a 5 MW grid-connected solar power plant at airport sites by utilizing the substantial barren area of the airport. The targeted airports for this study are Hazrat Shahjalal International Airport, Dhaka, and Shah Amanat International Airport, Chittagong, Bangladesh. Mathematical and simulation analyses have been performed for this purpose. Besides, sustainability analysis has also been incorporated for the grid-connected solar power plant. The energy efficiency varies from 18.74 to 7.79% for the Shah Amanat International Airport, and for the Hazrat Shahjalal International Airport, it ranges from 17.71 to 7.45%. Based on the project outcome, the revenue earned was 25% higher if the total cost was invested in power plants rather than keeping it in the bank as a deposit. On the other hand, emission analysis presented that a gross reduction of 3827.5 tons of CO2/MWh can be achieved from the Shah Amanat International Airport, while 3926 tons of CO2/MWh can be removed from the Hazrat Shahjalal International Airport. Based on the sustainability analysis, the energy depletion ratio for Shahjalal Airport varies from 0.82 to 0.93, while for Shah Amanat Airport, it is in the range of 0.81 and 0.92. The findings of this study suggested that investment in grid-connected solar power plants is economically viable and environmentally benign.

Estimating marine plastic pollution from COVID-19 face masks in coastal regions.

Face masks are playing an essential role in preventing the spread of COVID-19. Face masks such as N95, and surgical masks, contain a considerable portion of non-recyclable plastic material. Marine plastic pollution is likely to increase due to the rapid use and improper dispensing of face masks, but until now, no extensive quantitative estimation exists for coastal regions. Linking behaviour dataset on face mask usage and solid waste management dataset, this study estimates annual face mask utilization and plastic pollution from mismanaged face masks in coastal regions of 46 countries. It is estimated that approximately 0.15 million tons to 0.39 million tons of plastic debris could end up in global oceans within a year. With lower waste management facilities, the number of plastic debris entering the ocean will rise. Significant investments are required from global communities in improving the waste management facilities for better disposal of masks and solid waste.

Synthesis of biodiesel from chicken skin waste: an economic and environmental biofuel feedstock in Bangladesh.

One of the dominating meat supply industries, the poultry chicken sector, is facing waste management concerns worldwide. Due to high oil content containment, biofuel researchers emphasized poultry waste as abundant, cheap, and high-quality feedstock for biodiesel production. Therefore, in the current study, an experimental investigation of biodiesel production from wasted chicken skin through the transesterification process has been performed. The chicken skin used in this study for biodiesel production can be used as the potential waste source for biodiesel production worldwide. Techno-economic, environmental, and sustainability analyses were also performed. During the synthesis, the reaction was conducted with potassium hydroxide (KOH), and the process yielded 48% biodiesel. The cost of electricity for providing electricity is estimated at US$0.575 per kWh when an auto-sized generator has been fueled by biodiesel. The environmental and substantiality analysis found that biodiesel is more suitable than conventional diesel as an environmentally friendly and sustainable fuel.

Exergetic sustainability analysis of industrial furnace: a case study.

Industrial furnaces play a significant role in industrial energy consumption and production. Minimizing losses from these furnaces can contribute to industrial sustainability. Exergy being an optimization tool can reduce energy loss and emission from furnaces and contribute to environmental sustainability. Currently, no exergy-based sustainability analysis has been adopted in the literature. In this analysis, a reheater furnace that is fired by natural gas is analyzed in terms of energy and exergy utilization. To address the sustainability of the furnace, several exergy-based sustainability parameters have been used. The overall energy efficiency of the furnace is 93.40%, while exergy efficiency is only 27.37%. From sustainability analysis, it is found that 72.63% of the fuel is diminished from the furnace, and it contributes to a lower sustainability index of 1.38. Higher exergy losses from this furnace positively affect the environment, which is validated from the higher value of the environmental destruction coefficient, the environmental destruction index, and the lower value of the environmental benign index. The value of the environmental destruction coefficient is 3.65, and the value of the environmental benign index is 0.38. Recovering waste energy and optimizing auxiliary equipment will increase the value of sustainability parameters.