Friction as a probe of surface properties of a polymer glass

We probe the temperature dependence of friction at the interface between a glassy poly(methylmethacrylate) lens and a flat substrate coated with a methyl-terminated self-assembled monolayer. The monolayer exhibits density defects which act as pinning sites for the polymer chains. We show that the shear response of such an interface supports the existence, at the surface of the glassy polymer, of a nanometer-thick layer of mobile chains. Friction can be ascribed to the interplay between viscouslike dissipation in this layer and depinning of chains adsorbed on the substrate. We further show that the pinning dynamics is controlled by \beta rotational motions localized at the interface

A Guide to Hiring Women with Disabilities

[Excerpt] Census Bureau data from 2013 show that 12.6 percent of the U.S. population has some form of disability, although estimates of the proportion of the population living with a disability may vary depending on the definition of the term disabled. In 2014, working-age (16-64 years old) women with disabilities made up 1.5 percent of the workforce even though they were nearly 4 percent of the U.S. working age population. These women represent a critical source of untapped labor force talent. In 2014, seven in ten working-age individuals with disabilities were not in the labor force, compared with about two in ten working-age individuals with no disability. In addition to facing persistently low employment, women with disabilities often face difficulties accessing adequate housing, health and education; unequal hiring and promotion standards; and unequal pay

Working Mothers in the U.S. (Infographic)

Working_Mothers_Infographic.pdf: 20 downloads, before Oct. 1, 2020

Women Veterans Profile

Women veterans are the fastest growing segment of the veteran community. In 2013, about 2.2 million (or 10 percent) of the nation’s nearly 22 million veterans were women. This number is projected to increase to 2.4 million by 2020. In contrast, the number of male veterans is projected to decrease from 20.1 million to 17.2 million by 2020

Expenditures on Public Transportation

Public transportation expenditures consumed 6 percent of the average household\u27s transporation budget in 1997, divided between intracity and intercity travel (22 percent and 78 percent of total public transportation expenditures, respectively). Intracity transportation modes include mass transit, taxi and limousine service, and school bus. Intercity transportation modes include air, bus, train, and ship. This report highlights public transportation expenditures by consumer units in 1997, classified by income quintiles and by region

What Women Earned in 1998

[Excerpt] Women who work full time, regardless of age, race, or educational attainment, earn less, on average, than men. Overall, in 1998, median weekly earnings of female full-time wage and salary workers were $456 compared to$598 for men. Twenty years earlier the pay differential was even greater, however. In 1979, women who were full-time wage and salary workers had earnings that were only about three-fifths those of men. By 1998, however, women’s earnings were approximately three-quarters those of men

Spending Patterns of High-income Households

[Excerpt] Although, less than 6 percent of the Nation’s consumer units (CUs) had annual incomes of more than $90,000 in 1994-95, these households accounted for over 14 percent of total annual spending. High income households spent about$405 billion of the $2.8 trillion total outlays of complete income reporter households. These high-income households, on average, spent more than other households (see table), and they allocated their expenditures differently (see chart). Households with annual incomes of more than$90,000, allocated larger shares to food away from home; housing operations, supplies and furnishings; personal insurance and pensions; cash contributions; entertainment; and apparel and services. Households with lower annual incomes allocated larger shares to food at home, shelter and utilities, transportation, and health care

Involuntary Part-time Work On The Rise

[Excerpt] A number of labor market indicators from the Current Population Survey (CPS) have pointed to a weakening labor market for more than a year, even before the onset of the current recession in December 2007 (as designated by the National Bureau of Economic Research). The official unemployment rate, for example, rose by 2.3 percentage points from its recent low of 4.4 percent in March 2007 to 6.7 percent in November 2008. The employment-population ratio, which is the proportion of the working-age population that is employed, trended down from a recent peak of 63.4 percent in December 2006 to 61.4 percent in November 2008

Why Has Unemployment Risen? Insights From Labor Force Flows

[Excerpt] Several economic indicators have shown that the labor market weakened from May 2007 to May 2008. The number of unemployed persons rose from 6.9 million to 8.5 million, and the jobless rate increased from 4.5 to 5.5 percent. Intuitively, a rise in unemployment might be expected to coincide with a decline in employment. However, total employment, as measured by the Current Population Survey (CPS), was little changed over this period. Recently released experimental data series on the flows of people between different labor force statuses help explain how unemployment increased