China
Africa
Explore chapters and articles related to this topic
End Life Cycle Recycling Policy Framework for Commercially Available Solar Photovoltaic Modules and Their Environmental Impacts
Published in Satya Bir Singh, Prabhat Ranjan, Alexander V. Vakhrushev, A. K. Haghi, Mechatronic Systems Design and Solid Materials, 2021
Manisha Sheoran, Pancham Kumar, Susheela Sharma
Using transition metals like cadmium, copper, and other elements like tellurium, selenium, silicon in the manufacturing of bulk and thin-film solar photovoltaic materials causes major concern for health and environment at their end of life phase [22]. During the operation phase, bulk and thin-film solar photovoltaic panels cause no harm to the environment. Exposure to arsine, cadmium, germane, lead, phosphorous oxychloride causes issues related to kidney which can further lead to nephrotoxicity [15, 33, 34]. Arsine and carbon tetrachloride can cause a severe effect on the lungs. Hydrogen fluoride and compounds of indium used in the manufacturing of thin-film photovoltaic materials cause detrimental effects on bones and teeth. Deposition of fluoride and indium compounds on bones and teeth causes skeletal and dental fluorosis. Exposure to phosphine causes cardiovascular dysfunction, gastrointestinal disorder; it can also act as a pulmonary irritant. Phosphine can also catch fire due to a sudden rise in the ambient temperature, which can lead to hemorrhage, neuropsychiatric disorders, respiratory and renal failures within a few hours of exposure [35]. Inhalation of germane during the manufacturing of thin-film photo-voltaic materials can lead to dizziness, abdominal pain, and headache. Germane catches fire quickly on exposure to air; it can also lead to an explosion on exposure to high temperatures and can also cause a hazard. Long term exposure to germane and arsine causes lesions of blood cells which result in decreased efficiency to carry blood. Indium compounds can also cause irritation to the eyes, skin, and esophagus. Silane, selenium oxides, and selenium hydroxides on inhalation can cause irritation to the skin, eyes, and mucous membrane [22, 36]. The major emphasis in this section is given on human health during the manufacturing and after the recycling process. The environmental aftereffects on humans included the carcinogenic effects of Cd, Te, Se, arsine, carbon tetrachloride, etc., and other health issues as discussed above on various body organs are shown in Figure 7.8.
Conclusive determination of ethynyl radical hydrogen abstraction energetics and kinetics*
Published in Molecular Physics, 2020
Michael C. Bowman, Alexandra D. Burke, Justin M. Turney, Henry F. Schaefer III
Figure 1 illustrates the geometries of each hydrogen abstraction transition state. Table 3 shows the relative enthalpy of each transition state compared to its respective reactants. Since the majority of these reactions feature an early barrier, the spin-orbit splitting at the transition state has been regarded as negligible. While the energetics of the products were determined to have an uncertainty of 0.32 kcal mol in Table 1, the relative energetics of transition states are more sensitive to the level of theory employed. For this reason, we expect barrier heights to be reliable to within about 0.4 kcal mol. At 300 K, an uncertainty of 0.4 kcal mol corresponds to an uncertainty in the rate constant of about a factor of 2, which is sufficient for accurate kinetics. Of the corrections listed in Table 3, is noticeably the largest, contributing up to 40% of the total relative enthalpy for some transition states. This suggests that accurate barrier heights require not only accurate electronic energies, but reliable vibrational frequencies as well. Furthermore, is the largest for the third row donors, PH, HS, and HCl. Without the barrier heights of period 3 donors would not be converged to the accuracy required for quantitative predictions. The abstraction of a hydrogen from silane (SiH) is expected to have a comparable contribution from scalar relativistic effects. For fourth row donors such as germane (GeH), arsine (AsH), hydrogen selenide (HSe), or hydrogen bromide (HBr), the relativistic effects will contribute significantly more and a computational approach that directly incorporates scalar relativity would likely be more appropriate. Lastly, while the diagonal Born–Oppenheimer corrections for the reaction enthalpies in Table 1 were consistently minor (≤0.1 kcal mol), this is not the case for the transition states, where values are as large as 0.4 kcal mol.