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The Endangered Global Atmosphere
Published in Stanley E. Manahan, Environmental Chemistry, 2022
The concentration of ozone in the stratosphere is a steady-state concentration resulting from the balance of ozone production and destruction by the aforementioned processes. The region of the stratosphere in which significant amounts of ozone occur is called the ozone layer. The boundaries of the ozone layer vary with altitude, but it is generally regarded as extending from 15 to 35 km. At higher altitudes above 35 km, the level of atmospheric gases is very low, most of the oxygen is dissociated to O atoms, and there is very little molecular O2 with which the O atoms can combine to produce O3 . At lower altitudes below approximately 15 km, most of the short-wavelength ultraviolet radiation capable of producing O atoms required for ozone production has been filtered from sunlight by the atmosphere above.
Energy and Changes in the Environment
Published in Michael Frank Hordeski, Hydrogen & Fuel Cells: Advances in Transportation and Power, 2020
Ozone is a form of oxygen (O3), where three oxygen atoms combine into one molecule. Ozone has the property of absorbing most of the sun’s ultraviolet radiation. It does this in the upper part of the atmosphere, called the stratosphere, which is about 6 to 30 miles (10–50 kilometers) above the earth. This absorption of ultraviolet energy causes the stratosphere to heat up. Life on earth has been dependent on the ozone layer shielding us from harmful solar ultraviolet radiation. Ozone is part of the greenhouse effect, although it is not as important as CO2 or methane. Ozone in the lower atmosphere can cause damage to plant or lung tissues and is a pollutant in photochemical smog.
Beneficial Industrial Uses of Electricity: Industrial Introduction and Process Industries
Published in Clark W. Gellings, 2 Emissions with Electricity, 2020
Due to its high reactivity, it is not practical to store ozone; therefore, it is generated on-site. It has a half-life of less than 24 hours in the dry gaseous state and rapidly decomposes when moisture is present, especially at alkaline pHs. Ozone can be produced by a variety of methods including corona discharge, photochemical formation as the result of ultraviolet radiation, electrolysis of water, electrolytic reduction of concentrated sulfuric acid, nuclear radiation using Cobalt 60m and passing moist air over elemental phosphorus.
Numerical investigation of flashing of propane (R-290) in a helical capillary tube
Published in Numerical Heat Transfer, Part A: Applications, 2023
Soumik Bose, Sofen Kumar Jena, Sewan Das Patle
With the development in the world’s economic condition, home appliances like refrigerators and air conditioners are more prevalent. The uses of these appliances touch sky root after the economic development of South Asian countries like India and Bangladesh. Extreme hot climate in the subcontinent region makes AC and refrigerators an essential household requirement. These HVAC devices provide cooling comfort in a closed space, while it disturbs the surrounding by contributing to global warming and emitting harmful gasses to the atmosphere. CFC (Chloro-Fluoro-Carbon) emission to the atmosphere results in stratospheric ozone layer depletion. At the same time, leakage of HFC (hydrofluorocarbons) is thousands of times more potent than carbon dioxide for the greenhouse effect. One kg R410a refrigerant has the same greenhouse impact as two tonnes of carbon dioxide, equivalent of driving a car continuously for six months. Humanity is caught in a feedback loop where warmer temperatures require essential cooling, and excessive use of cooling devices results in a warm environment. The action gradually contributes more to the original problems. This lethal deadlock provokes the scientific community the search for a quick, efficient, and sustainable solution. After the 2016 Paris agreement, international energy agency (IEA) is deliberately looking for an efficient cooling technique to tackle the reduction in new power sector infrastructure to meet rising HVACs demand. In hotter countries like India, AC in peak electricity load could reach 45 percent by 2050, from 10% today without discovering effective cooling mechanisms.
Bacteriostasis and cleaning effect of trace ozone replacing personal care products
Published in Environmental Technology, 2023
Yanyan Peng, Zhou Chen, Yanzeng Li, Yuantao Wang, Chengsong Ye, Junming Xu, Shenghua Zhang
Ozone is produced by air or oxygen through high voltage discharge or intense ultraviolet radiation. As a strong oxidant with highly effective bactericidal functions, ozone is widely used for treating drinking water and effectively applied as a disinfectant in hospital environments [19,20], through which the deposition of pathogens on surfaces can be effectively reduced and the spread of pathogens via aerosols prevented [21]. However, the inhalation of ozone gas is extremely harmful to human respiratory health, and workers should perform disinfection activities in environments with ozone concentrations less than 0.16 ppm, and the exposure time should be less than 8 h [22]. Currently, trace ozone can be widely used as a bactericidal agent. For instance, the use of 0.5 mg/L ozonized oil instead of chemical drugs was effective in the treatment of skin diseases caused by Microsporum gypseum and Microsporum canis [23]. Sadatullah et al. [24] also illustrated that exposure to ozonated water at a concentration of 0.1 mg/ L for 30 s could effectively reduce microbial load on dental plaque.
Characterization of a Doped MnO2Al2O3 Catalyst and its Application Inmicrobubble Ozonation for Quinoline Degradation
Published in Ozone: Science & Engineering, 2021
Xinwang Liu, Shutao Wang, Hao Yang, Zhisheng Liu, Ying Wang, Fucheng Meng, Jun Ma, Oksana S. Izosimova
Ozone was produced by an ozone generator (Ozomat COM-AD-01, Anseros, Germany) with pure O2 as the feed supply. The oxygen was produced by an oxygen generator (Everflo, Philips, USA). The ozone concentration was measured using an ozone detector (Ozomat GM-6000-OEM, Anseros, Germany). Microbubbles of ozone were produced using a microbubble generator (NB-200-10, Shanghai Harp Biotechnology Co., Ltd. (Shanghai, China). laser scattered particle analyzer (Mastersizer 2000, British) was used to test the size of microbubble ozone. The mechanical strength of the catalyst particles was tested using an electronic tensile tester (AG-X 50kN, Shimadzu Corp., Japan). The XRD patterns were obtained using D/max-rB (Japanese Science and Technology, Japan). The specific surface area and porosity were analyzed by a fully automated surface area and porosity analyzer (ASAP2020 M, Micromeritics, USA). The surface morphology of MnO2 and the catalyst was observed by SEM (SEM, S-4700, Hitachi, Japan). The concentration of quinoline was determined using high-performance liquid chromatography (HPLC, Waters 2695, Waters Corporation, USA) (C-18-AR-II column, UV detector (313 nm), mobile phase methanol:water 1:1).