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Units and Significant Figures
Published in Patrick F. Dunn, Fundamentals of Sensors for Engineering and Science, 2019
The mole (mol) is the SI base unit for the amount of substance. It is the amount of substance of a system that contains as many elementary entities as the number of atoms in 0.012 kg of carbon 12 (6.022 142 × 1023= Na).
Units and Significant Figures
Published in Patrick F. Dunn, Michael P. Davis, Measurement and Data Analysis for Engineering and Science, 2017
Patrick F. Dunn, Michael P. Davis
The mole (mol) is the SI base unit for the amount of substance. It is the amount of substance of a system that contains as many elementary entities as the number of atoms in 0.012 kg of carbon 12 (6.022 142 × 1023= Na). That is, 1 mol contains Na entities, where Na is Avogadro’s number. The entities can be either atoms, molecules, ions, electrons, other particles, or groups of such particles. The entities could even be golf balls! So, 1 mole of carbon 12 has a mass of 0.012 kg, 1 mole of monatomic oxygen has 0.016 kg, and 1 mole of diatomic oxygen has 0.032 kg. Each contains 6.022 142×1023 entities, which would be atoms for carbon 12 and for monatomic oxygen and molecules for diatomic oxygen. The mass of 1 mole of a substance is determined from its molecular (atomic) weight. Its SI units are kg/kg-mole. The atomic mass unit, typically designated by the symbol amu. This exactly equals 1/12 the mass of one atom of the most abundant isotope of carbon, carbon-12, which is 1.6603 × 10−27 kg. This unit of mass is called a dalton.
Matter
Published in Mohammad E. Khosroshahi, Applications of Biophotonics and Nanobiomaterials in Biomedical Engineering, 2017
Let us start with the definition of a substance which is a distinct form of matter. The amount of substance, n in a sample is reported in terms of a unit called a mole where 1 mol is the amount of substance that contains as many as entities (molecules, atoms,...) as there are in exactly 12 g of carbon-12. This number is called the Avogadro constant, NA = 6.02 × 1023. Thus, if a sample contains N entities, the amount of substance it contains is n = N/NA. An extensive property is one which depends on the amount of substance in the sample such as mass and volume. An intensive property on the other hand, is independent of the amount of substance such as temperature, pressure and mass density. By studying the properties of matter, forces, energy and their various interactions, scientists can have a better understanding regarding the behaviour of solids, liquids and gases—the three main phases of matter.
Effect Mechanisms of Sodium on NO Heterogeneous Reduction by Nitrogen-Containing Char: Experimental and DFT Investigation
Published in Combustion Science and Technology, 2022
Yinbo Yang, Lihong Wei, Qian Zhou, Hang Yu, Baochong Cui, Lun Luo
where Φads is the capacity of NO adsorption, mmol/g. m is the amount of char, g. n is the amount of substance, mol. R is gas constant, J·mol−1·K−1. D, P, and T stand for the flow, the pressure, and the temperature, respective, ml/min, Pa, and K. CNO, out andCNO, blank represent the outlet concentration of NO of char sample and the blank experiment, respectively, ppm. t1 and 120 represent the time of NO chemisorption (SL time) and reduction reaction, min. Xi represents the char sample (DC, DCSC1 to DCSC7). CXi, CO stand for the outlet concentration of CO of char sample, ppm. stand for the maximum amount of CO release in the series of samples. According to the existing literature (Yan et al. 2017), the output of NO and CO in the process are determined by integrating the time series of outlet gas concentration given by the gas analyzer.
A review of dust emission dispersions in rock aggregate and natural stone quarries
Published in International Journal of Mining, Reclamation and Environment, 2018
M. Sairanen, M. Rinne, O. Selonen
Dust monitoring techniques 1–6 constitute active techniques. According to Mineral Industry Research Organisation [29], active techniques draw volumes of air for a designated time period to measure the amount (particle concentration and mass) and type of dust (particle size fraction) suspended in the air. Measurement results are concentrations; a measure of the amount of substance contained per unit of volume. Deposit gauges represent passive techniques based on the principle that coarse particles suspended in the air fall out either under the influence of gravity (dry deposition) or in contact with water droplets (wet deposition) [29]. Besides measurements, dust load in the environment can be evaluated via calculation with emission factors. An emission factor is a representative value that relates the quantity of a pollutant released to the atmosphere with an activity associated with the release of that pollutant [30], for example kilogrammes of dust for every processed ton.
Refractive index fluctuation spectrum of lightwave propagation in supersonic compressible turbulent flow
Published in Waves in Random and Complex Media, 2022
Jinyu Xie, Lu Bai, Yankun Wang, Lixin Guo
In aero-optical applications, the time scale of light waves can be ignored; therefore, optical transmission can be solved in a frozen field. is the refractive index of the air around the aircraft and is one of the most important parameters for exploring the aero-optics effect. mainly affects the phase distribution of transmission. To derive the refractive index fluctuation spectrum, the autocorrelation function of the refractive index needs to be determined. In the optical wave bandwidth, the air refractive index satisfies the Gladstone-Dale (G-D) relationship [38], where and is the air density. is the G-D constant, which is a parameter related to the optical wavelength. The air density is related to pressure and temperature. According to Ref. [34], if the ideal gas equation is adopted, . However, in this paper, the volume occupied by the molecules is considered, and a simplified van der Waals equation is adopted, where . is the amount of substance (mole). b is the average space occupied by each mole molecule. Then, . The first-order fluctuating component of the refractive index is (see Appendix A for the specific derivation) where , , , and are the component fluctuations in space and time, and , , , and are the statistical averages of the components.