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In the laboratory, SiCl 4 can be prepared by treating silicon with chlorine at 600 °C (1,112 °F): [1] Si + 2 Cl 2 → SiCl 4. It was first prepared by Jöns Jakob Berzelius in 1823. [4] Brine can be contaminated with silica when the production of chlorine is a byproduct of a metal refining process from metal chloride ore.
Life chances (Lebenschancen in German) is a theory in sociology which refers to the opportunities each individual has to improve their quality of life. The concept was introduced by German sociologist Max Weber in the 1920s. [ 1 ]
Human life expectancy is a statistical measure of the estimate of the average remaining years of life at a given age. The most commonly used measure is life expectancy at birth (LEB, or in demographic notation e 0, where e x denotes the average life remaining at age x). This can be defined in two ways.
These stressors—and the associated burden of coping with them—manifest as physiological responses that have detrimental effects on individual health, often leading to a disproportionately high occurrence of chronic illness and shorter life expectancy in minority communities. [13]
2003 US mortality table, Table 1, Page 1. In actuarial science and demography, a life table (also called a mortality table or actuarial table) is a table which shows, for each age, the probability that a person of that age will die before their next birthday ("probability of death").
The sociology of health and illness, sociology of health and wellness, or health sociology examines the interaction between society and health. As a field of study it is interested in all aspects of life, including contemporary as well as historical influences, that impact and alter health and wellbeing. [1] [2]
The pyrolysis of SiBr 4 does have the advantage of depositing silicon at faster rates than that of SiCl 4, however SiCl 4 is usually preferred due to its availability in high purity. [13] Pyrolysis of SiBr 4 followed by treatment with ammonia yields silicon nitride (Si 3 N 4 ) coatings, a hard compound used for ceramics, sealants, and the ...
A microlife is a unit of risk representing half an hour change of life expectancy. [1]Discussed by David Spiegelhalter and Alejandro Leiva, and also used by Lin et al. [2] for decision analysis, microlives are intended as a simple way of communicating the impact of a lifestyle or environmental risk factor, based on the associated daily proportional effect on expected length of life.