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Applied Chemistry and Physics
Published in Robert A. Burke, Applied Chemistry and Physics, 2020
Elements are the building blocks of chemical compounds. Symbols are used to represent each of the elements on the table. The periodic table is composed of a series of blocks representing each element. Within each block is a symbol that represents the name of that element. Also within the block is the atomic number (Figure 3.19) and atomic weight (Figure 3.20). The symbol is a type of shorthand for the element’s name. For example, carbon has a symbol of C, the element gold is represented by the symbol Au, chlorine’s symbol is Cl and potassium’s symbol is K. Each symbol represents one atom of that element. Symbols may be a single letter or two letters together. Single letters are always capitalized. When there are two letters, the first is capitalized and the second is always lowercase. This is important to understand when trying to identify elements and compounds. For example, CO is the molecular formula for the compound carbon monoxide; Co,on the other hand, is the symbol for the element cobalt. There are two totally different materials with quite different hazards.
Principles of Physics
Published in Arthur T. Johnson, Biology for Engineers, 2019
The movement of matter is critical to living systems at all levels. The sources of energy often take the form of energy-rich compounds, and these must move from wherever they are located into cells. There are other compounds necessary for the well-being of the living system. These include enzymes, coenzymes, minerals, and chemical building blocks (such as amino acids). These must also be transported into the cells. The consequence of metabolism is the production of waste products, which either must be removed or stored in immobilized form. The accumulation of these waste products (including carbon dioxide, lactate, urea, alcohol, and others) can severely harm the organism, and so must be transported away.
Feedstock Integration in the Refinery
Published in James G. Speight, Refinery Feedstocks, 2020
Although the focus of this section has been on the production of hydrocarbon derivatives from synthesis gas, it is worthy of note that clean synthesis gas can also be used (i) as chemical building blocks to produce a broad range of chemicals using processes well established in the chemical and petrochemical industry), (ii) as a fuel producer for highly efficient fuel cells (which run off the hydrogen made in a gasifier) or perhaps in the future, hydrogen turbines and fuel cell-turbine hybrid systems, and (iii) as a source of hydrogen that can be separated from the gas stream and used as a fuel or as a feedstock for refineries (which use the hydrogen to upgrade crude oil products).
Compressed unfired blocks made with iron ore tailings and slag
Published in Cogent Engineering, 2022
Sustainable building blocks should be able to reduce inputs from natural resources and also minimize environmental impact during various stages of production. Therefore, to understand the environmental benefits of prepared blocks, it is important to know the total energy consumption and CO2 emissions. While it is difficult to establish accurate environmental benefits of the proposed blocks due to lack of existing information on iron ore tailings, it is still possible to appreciate the benefits of such construction materials by the outcome of study by (Oti & Kinuthia, 2012). According to the authors, unfired blocks produced with GGBS and lime substantially reduce energy usage and total CO2 emissions. As seen in Figure 12, it translates to 84% lower energy usage and 80% lower CO2 emissions for unfired blocks when compared to fired bricks, respectively. Furthermore, there are ill-effects of waste IOT disposed at tailing dams, which has also resulted in devasting effects on the environment (Hk & Hossiney, 2021; Protasio et al., 2021). Therefore, utilization of IOT in compressed unfired blocks will incur benefits such as minimization of waste at the dumping sites and reduced use of virgin raw materials for block production. Furthermore, IOT building blocks can be a perfect candidate for energy-efficient masonry wall structures and also aid towards construction of cost-effective houses in developing countries.
Preparation and characterisation of environmental-friendly ceramsites from iron ore tailings and sludge
Published in International Journal of Sustainable Engineering, 2021
Z. Wang, H. J. Chen, L. Z. Pei, X. Y. Guo, C. G. Fan
Sludge is a kind of industrial byproducts with a high organic content and adsorption capacity (Zou and Li 2008; Liu et al. 2016b). High content of SiO2 and Al2O3 in the sludge makes them suitable as the ceramic skeleton components. The gas, such as H2O, O2, CO2 and SO2 can be generated by the oxidation reaction process (Sun et al. 2017; Li, Luo, and Jin 2013; Liu et al. 2013). Building blocks, cement, concrete and bioplastics have been reported showing good application promising in the fields of construction and plastics industry (Sharma and Joshi 2016; Singhal, Tewari, and Prakash 2008; Khardenavis et al. 2009; Modolo et al. 2011; Soucy et al. 2014). The high-temperature calcination of the sludge and tailings is a promising method to improve the performance of the ceramsites (Xu, Zou, and Dai 2006). Iron ore tailing and sludge ceramsites take the advantages of the products, such as increasing mechanical strength by the component fixation, removal of contaminants by high-temperature organic decomposition and gasification, and stabilisation of harmful metals by the incorporation of phases (Tang, Chan, and Shih 2014; Sonowal, Khwairakpam, and Kalamdhad 2014; He and Wang 2011; Wang et al. 2016). In the work, iron ore tailing/sludge ceramsites have been obtained using the iron ore tailings and sludge as the raw materials. The roles of the tailing content and sintering parameters on the performance of the ceramsites have been analysed in detail. The optimal tailing content, sintering temperature and duration time have been determined. The formation of the ceramsites has been investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM).
Identifying and addressing challenges in the engineering design of modular systems – case studies in the manufacturing industry
Published in Journal of Engineering Design, 2019
Jarkko Pakkanen, Tero Juuti, Timo Lehtonen
These building blocks are tools for thinking, as they highlight aspects of engineering design that are important for realising benefits from reuse and product variety. Previous research has proposed that successful consideration of these building blocks in the design process opens up possibilities for business benefits if a company needs to rationalise its existing product assortment (Pakkanen 2015; Pakkanen, Juuti, and Lehtonen 2016). The presumption is that this assortment does not enable reuse of product elements or effective configurability of product variants (in the ideal case, the need for delivery-specific engineering should be as low as possible).