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Basics of Metal Matrix Composites and Their Application in Transistor Electronics
Published in Suneev Anil Bansal, Virat Khanna, Pallav Gupta, Metal Matrix Composites, 2023
Anand Sharma, Triloki, Sanjeet Kumar, Vishwas Acharya
The most commonly used reinforcements are Silicon Carbide (SiC) and aluminum oxide (Al2O3). Al2O3 reinforcement has good compressive strength. In general, Al2O3 is well known ceramic material and is widely used in various fields, e.g., aerospace industry, automobile industry, and other engineering applications. Aluminum matrix composites find a wide range of popularity in the transportation sector because of their lower noise and lower fuel consumption than other materials. Apart from these, aluminum oxide is frequently and dominantly used in portable and low-power electronics. Aluminum and its composite and oxide can be used in different manners such as pure aluminum, which is used as a metal for electrode deposition and aluminum oxide broadly used as a ceramic in electronics and ceramic industries. On the other hand, in some famous research groups, aluminum was used as an element in different matrices and successfully utilized as a semiconductor (Bains, Sidhu, & Payal, 2016; Chawla, 2012b; Dasgupta, 2012; Ramnath et al., 2014).
Industrial Ecology for Waste Minimization, Utilization, and Treatment
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Vitrification or glassification consists of imbedding wastes in a glass material. In this application, glass may be regarded as a high–melting temperature inorganic thermoplastic. Molten glass can be used, or glass can be synthesized in contact with the waste by mixing and heating with glass constituents—silicon dioxide (SiO2), sodium carbonate (Na2CO3), and calcium oxide (CaO). Other constituents may include boron oxide, B2O3, which yields a borosilicate glass that is especially resistant to changes in temperature and chemical attack. In some cases, glass is used in conjunction with thermal waste destruction processes, serving to immobilize hazardous waste ash constituents. Some wastes are detrimental to the quality of the glass. Aluminum oxide, for example, may prevent glass from fusing.
Luminescent, Film, and Cryogenic Detectors
Published in Douglas S. McGregor, J. Kenneth Shultis, Radiation Detection, 2020
Douglas S. McGregor, J. Kenneth Shultis
Aluminum oxide is the chemical name for a mineral often regarded as a precious gem. If it has a small amount of Cr impurity (Cr2O3) it is called ruby. Other gem quality samples are called sapphires, associated with a wide range of colors according to the residual impurities. Otherwise, the common name for Al2O3 is corundum. Aluminum oxide is one of the hardest known substances, rated as 9 on the Mohs hardness scale. Aluminum oxide is mostly chemically inert and it is water insoluble. It has high electrical resistance and its melting point is extremely high at 2072°C.
Polyethylene terephthalate conversion into liquid fuel by its co-pyrolysis with low- and high-density polyethylene employing scrape aluminium as catalyst
Published in Environmental Technology, 2023
The higher total % conversion in the case of the catalytic process could be attributed to two distinct properties of aluminium. The aluminium has a high thermal conductivity which effectively transfers heat to the polymer chains thereby increasing the total % conversion (polymer degradation). Its thermal conductivity is 235 W/m K (watts per metre per kelvin) which is much higher than that of stainless steel, i.e. 15 W/m K [32]. That is why the reactions carried out in the steel reactor without aluminium resulted in less total % conversion. The second reason is that aluminium has a high affinity for oxygen forming a layer of aluminium oxide Al2O3 on its surface upon exposure to air [33]. Aluminium oxide is well known for its catalytic activity in petrochemical and oil refining processes. Its thermal stability is as high as 700 °C [34].
Electron withdrawing ligands inhibit oxygen transport by Al+: temperature-dependent kinetics of AlO+/(O2)AlO+ + H2/CH4
Published in Molecular Physics, 2023
Brendan C. Sweeny, Shaun G. Ard, Albert A. Viggiano, Nicholas S. Shuman
Aluminium oxide is an Earth-abundant chemical compound whose role in catalysis is often in the bulk size regime as an insulator or support material. There is also abundant literature involving the catalytic roles of bulk AlxOy, Al nanoparticles, and Al superatoms [1–8]. Gas phase studies have commonly been used to decipher the mechanisms of bulk catalytic systems [9] Schwarz and co-workers reported gas phase kinetics of Al2O3+, mimicking a key feature of the (110) aluminium oxide surface, with methane, showing an effective conversion to formaldehyde [10]. The calculated reaction coordinate showed the formation of an intermediate containing a methanol moiety without a barrier, but no oxidation of methane to methanol was observed despite the reaction being exothermic. Instead, that key intermediate is dissociated by loss of a methyl group, which is favoured on energetic grounds. That is, the reaction preferentially underwent hydrogen-atom transfer (HAT) instead of oxygen-atom transfer (OAT). The key step in the reactivity, both in the gas phase and in the bulk, occurs at a terminal oxygen atom, singly bound to an aluminium atom [11]. Further isolating this active site from its environment, our group studied the gas phase reaction of bare AlO+ with methane. In this case, the OAT product channel was observed, despite the calculated reaction coordinate being in many ways analogous to that of Al2O3+ [4]. Here we explore further the environmental effects that inhibit OAT relative to HAT at an AlO+ active site.
Impact of alumina and cerium oxide nanoparticles on tailpipe emissions of waste cooking oil biodiesel fuelled CI engine
Published in Cogent Engineering, 2021
Pijakala Dinesha, Sooraj Mohan, Shiva Kumar
Alumina is a general name of aluminium oxide, which is a chemical compound having aluminium and oxygen. It is available naturally as α-Al2O3, which is in crystalline polymorphic phase. The chemical structure of Al2O3 is shown in Figure 3, and the physicochemical properties are given in Table 3. Alumina has a very high thermal conductivity of 30 W m−1k−1 and non-conductor of electricity. Al2O3 in nanoparticle form is commonly used in heat exchangers to enhance heat transfer. It is also used as a fuel additive to improve the combustion. Due to its higher thermal conductivity, it enhances the rate of heat transfer between the fuel droplets. Several literature have been reported on the use of Al2O3 NPs as the fuel additives in biodiesel fuel engine. (Hosseini et al., 2017; Prabu et al., 2019; Roy et al., 2020; Soudagar et al., 2020)