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Light
Published in Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz, Agroecology, 2023
Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz
Light from the sun is the primary source of energy for ecosystems. It is captured by plants through photosynthesis, and its energy is stored in the chemical bonds of organic compounds. Sunlight also drives the earth’s weather: light energy transformed into heat affects rainfall patterns, surface temperature, wind, and humidity. The way these factors of the environment are distributed over the face of the earth determines climate and is of considerable importance in agriculture. All these sunlight-related factors will be reviewed in more detail in subsequent chapters.
Pillar
Published in Andrew Braham, Sadie Casillas, Fundamentals of Sustainability in Civil Engineering, 2020
The second metric, smog, was created as a by-product of the visual effect of pollution, commonly found over urban areas. Smog comes from two primary sources: emissions from coal power plants or emissions from transportation sources. When coal burns, it releases many emissions, such as carbon monoxide, carbon dioxide, sulfur dioxide, nitrous oxides, and PM10. While significant efforts have been made to clean the air as it escapes from coal power plants in the United States, some undesirable emissions still make it to the atmosphere. This problem is significantly higher in developing countries versus developed countries, as the cost of emission control at point sources is significantly high. The second main source of smog, transportation, often emits carbon monoxide, nitrous oxides, VOC, and various hydrocarbons (such as methane). High volumes of vehicles, especially slow-moving vehicles (such as those in traffic flow approaching jam density), exacerbate the emissions. What is more, once sources such as power plants or traffic emit emissions to create smog, a photochemical process can compound smog generation. When sunlight strikes nitrous oxide or VOC, it reacts with these emissions and generates even more smog. A continuous cycle is formed, where emissions that cause smog react with the sunlight to create more smog.
Lighting
Published in Sue Reed, Dino Pisaniello, Geza Benke, Kerrie Burton, Principles of Occupational Health & Hygiene, 2020
Exposure to sunlight is known to be harmful, especially to the mid-ultraviolet erythemal radiations (290–320 nm), which cause sunburn to appear within a few hours of exposure. Chronic exposure to sunlight for several hours a day over a period of some years can cause permanent changes in skin structure, including skin atrophy, the formation of keratin plaques and, in susceptible individuals, the appearance of squamous-cell carcinomas (Wurtman 1975b). One of the best-known direct effects of sunlight on humans is the stimulation of vitamin D synthesis in the skin and subcutaneous tissue. Not only is vitamin D essential for healthy bone development (conditions such as rickets and osteomalacia have been linked to a deficiency), but there is some evidence that the vitamin can also help protect against certain forms of cancer. Research by Grant (2002) suggests that sunlight is protective against breast, colon and prostate cancers.
Analysis of wind turbine usage in greenhouses: wind resource assessment, distributed generation of electricity and environmental protection
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Reza Shahbazi, Shahriar Kouravand, Reza Hassan-Beygi
The troposphere below the atmosphere is about 10–15 km in thickness. There are gases in the troposphere known as greenhouse gases. When sunlight comes to the ground, it causes ground heat, some of which is absorbed and maintained by greenhouse gases, which causes global warming. In general, global warming is one of the environmental degradation factors. Of course, the heat of the earth depends on the number of greenhouse gases and their concentration. The most important CO2, CFC emissions are NO, CH4. One of the risk factors for climate change is greenhouse gas emissions. After the industrial revolution, the release of these gases has increased. Earth warming has caused storms, melting ice in the pole, floods and landslides, deforestation and other environmental problems. One of the activities that increase carbon dioxide emissions in the atmosphere is the use of fossil fuels. Carbon dioxide remains in the atmosphere for about 50 to 200 years. The use of renewable energies, especially of wind energy that is converted by wind turbines into electrical energy, could reduce the release of carbon dioxide in the atmosphere and prevent global warming.
Benefit, cost, and size of an emission control area: a simulation approach for spatial relationships
Published in Maritime Policy & Management, 2019
This study has some limitations. First, the one-dimensional model in this study is not capable of analyzing ECAs in Europe, which would require a model for a linear city located on both sides of a real line, a linear sea situated in the middle of the real line, and an ECA covering an entire linear sea area. As the ECA would incorporate all the linear sea’s area, a ship would not be able to choose a route by evading the ECA. Thus, the model would differ significantly from the one-dimensional model used in this study. To analyze the European case, our one-dimensional model would need to be extended to a two-dimensional case. Second, our simulation model is based on a linear city and a linear sea. In reality, the sea seems to be a plane on a quasi-sphere, and ships choose more complicated routes and speeds (Fagerholt et al. 2015; Fagerholt and Psaraftis 2015; Gu and Wallace 2017) by considering many factors not taken into account in this study, like fuel price, load factor, vessel size, and frequency (Qiu, Wong, and Lam 2018; Zhu et al. 2018). Third, the simulation in this study does not factor in the chemical process of air pollutant reactions. Air pollutants not only disperse but also react chemically with other air pollutants with sunlight. Thus, this study underestimates the cost of air pollution exposure as well as underestimates the benefits from reducing exposure. Future research should address these issues.
Plastic microbeads: small yet mighty concerning
Published in International Journal of Environmental Health Research, 2021
Shaima S. Miraj, Naima Parveen, Haya S. Zedan
Biodegradable plastics are generally composites of synthetic polymers and vegetable oils, starch or other specialist chemicals designed to accelerate degradation. If they are disposed off properly, they will decompose in industrial composting plants under well-aerated conditions. Exposure to sunlight can result in photo degradation of plastics over a prolonged period of time; ultraviolet radiation causes oxidation of polymer matrix results in bond cleavage. But, such degradation may result in additives leaching out of the plastics, which are added to enhance durability of the plastics and make it corrosion resistance, (Moore 2008; Talsness et al. 2009; Andrady et al. 2019).