979,407 research outputs found
Sorption of sulfamethoxazole, sulfachloropyridazine and sulfamethazine onto six New Zealand dairy farm soils
We have investigated the sorption potential of three sulfonamides (SAs) in six New Zealand dairy farming soils using a modified batch equilibrium method employing 0.005 M CaCl₂ as background solution. Both liquid and solid phases were extracted to analyse for the antibiotic concentrations in order to avoid underestimation that may arise a result of photolysis or biotic degradation. The experimental data were later used to construct Freundlich isotherms to determine the effective distribution coefficients. Low log Koc value for all SAs suggests considerable leaching potential for SAs under conditions that are conducive for leaching. The sorption affinity for all soils followed the trend SCP>SMZ>SMO
Numerical shakedown and non-shakedown responses of a Tresca half-space to a three-dimensional moving load
Flexible pavements may fail due to excessive rutting as a result of accumulative plastic deformation; otherwise, if the load is small enough, pavements may deform plastically in the first number of load cycles and then reach a stable state which is termed as ‘shakedown’. Recently some lower-bound and upper-bound solutions have been developed to directly determine the load limit (i.e. shakedown limit) below which an elastic-plastic half space can shake down. However, the actual responses of an elasticplastic half-space subjected to repeated moving loads were not well revealed. In the present study, repeated moving surface loads are applied to a three-dimensional finite element model established in ABAQUS to research on the development of stresses and strains in a Tresca half-space. Also, a numerical shakedown limit can be determined according to the yield condition of structure under a static load following a number of load passes. It is found the development of residual stresses induced by plastic strains plays a key role in helping the half-space to reach the shakedown state. Good agreements are also observed between numerical and theoretical solutions for both shakedown limit and residual stress fields
Demographic, Residential, and Socioeconomic Effects on the Distribution of 19th Century African-American Body Mass Index Values
Little research exists on the body mass index values of late 19th and early 20th century African-Americans. Using a new BMI data set and robust statistics, this paper demonstrates that late 19th and early 20th century black BMI variation by age increased in their mid-30s but declined at older ages when worker physical productivity declined. Throughout the late 19th and early 20th centuries, black BMIs decreased across the distribution, indicating that the 20th century increase in black BMIs did not have its origin in the 19th century. During industrialization, black BMIs were lower in Kentucky, Missouri, and urban Philadelphia.nineteenth century U.S. economic development, body mass index, 19th century race relations
Slave Prices, Geography and Insolation in 19th Century African-American Stature
The use of height data to measure living standards is now a well-established method in the economic literature. Moreover, while much is known about 19th century black legal and material conditions, less is known about how 19th century institutional arrangements were related to black stature. Although modern blacks and whites reach similar terminal statures when brought to maturity under optimal biological conditions, 19th century African-American statures were consistently shorter than whites, indicating a uniquely 19th century phenomenon may have inhibited black stature growth. It is geography and insolation that present the most striking attribute for 19th century black stature, and greater insolation and higher slave prices are documented here to be associated with taller black statures.nineteenth century, African-American stature, slave prices, insolation, vitamin D
Geography and Insolation in 19th Century US African-American and White Statures
The use of height data to measure living standards is now a well-established method in the economic literature. Moreover, while much is known about 19th century black legal and material conditions, less is known about how 19th century institutional arrangements were related to black stature. Although modern blacks and whites reach similar terminal statures when brought to maturity under optimal biological conditions, 19th century African-American statures were consistently shorter than whites, indicating a uniquely 19th century phenomenon may have inhibited black stature growth. It is geography and insolation that present the most striking attribute for 19th century black and statures, and greater insolation is documented here to be associated with taller black and white statures.nineteenth century, African-American and white stature, insolation
Demographic, Residential, and Socioeconomic Effects on the Distribution of 19th Century US White Statures
Using a source of 19th century US state prison records, this study addresses European-American stature variation. The most commonly cited sources for stature variation are diets, disease, and work effort. However, vitamin D is also vital in human statures and health. This paper demonstrates that 19th century white statures were positively associated with direct sunlight, which is the primary source of vitamin D in mammals. Stature and insolation are associated with occupations, and workers who spent more time outdoors produced more vitamin D and grew taller. White statures also decreased throughout the 19th century, and this stature diminution is observed across the stature distribution.19th US white statures, vitamin D, solar radiation, quantile regression
Passionate about the Liberal Arts
An introduction to Dr. Thomas L. Hellie, Linfield College’s 19th president
Court hearing Somyot 19th December: an update
This document is part of a digital collection provided by the Martin P. Catherwood Library, ILR School, Cornell University, pertaining to the effects of globalization on the workplace worldwide. Special emphasis is placed on labor rights, working conditions, labor market changes, and union organizing.CCC_2012_Report_Thailand_court_hearing.pdf: 11 downloads, before Oct. 1, 2020
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