5,319 research outputs found
GRID PRICING: VALUING CATTLE QUALITY INFORMATION
Grid pricing is increasingly prominent in cattle markets. This study compares selling 11,703 head of fed cattle using grid, live, and dressed weight pricing. Cattle sold on a grid had price variability twice that of live or dressed. Average pricing inefficiency by not selling cattle on a grid exceeded $30/head.Demand and Price Analysis, Livestock Production/Industries,
Impact resistance of spar-shell composite fan blades
Composite spar-shell fan blades for a 1.83 meter (6 feet) diameter fan stage were fabricated and tested in a whirling arm facility to evaluate foreign object damage (FOD) resistance. The blades were made by adhesively bonding boron-epoxy shells on titanium spars and then adhesively bonding an Inconel 625 sheath on the leading edge. The rotating blades were individually tested at a tip speed of 800 feet per second. Impacting media used were gravel, rivets, bolt, nut, ice balls, simulated birds, and a real bird. Incidence angles were typical of those which might be experienced by STOL aircraft. The tests showed that blades of the design tested in this program have satisfactory impact resistance to small objects such as gravel, rivets, nuts, bolts, and two inch diameter ice balls. The blades suffered nominal damage when impacted with one-pound birds (9 to 10 ounce slice size). However, the shell was removed from the spar for a larger slice size
Faces of Social Work in South Africa: A Twenty:first Century Perspective
This qualitative mini-ethnographic study explores the current issues facing the profession of social work in South Africa after the first fully democratic elections in ten years ended the apartheid era. It employed interviews with social work educators and practitioners, politicians, and other professionals; personal observations of diverse settings; conversations with citizens including blacks, whites and coloreds; and meetings with experts attending an international conference on African policy planning. Social work educators and practitioners generally agreed that the two major social problems currently facing South Africa are poverty and violence. Poverty-related issues include homelessness, substandard and dangerous housing, substance abuse, unemployment and inadequate education, lack of adequate health and mental health services (HIV/AIDS rarely mentioned), plus victimization by crime-related violence and domestic abuse
Is the Woman-Owned Federal Contracting Program a Good Choice for your Business?
Set asides narrow the playing field and increase your chance of winning contracts. A contracting specialist explains the federal government set-aside program for woman-owned businesses and explores the advantages and disadvantages
Electrochemical Energy Storage Subsystems Study, Volume 2
The effects on life cycle costs (LCC) of major design and performance technology parameters for multi kW LEO and GEO energy storage subsystems using NiCd and NiH2 batteries and fuel cell/electrolysis cell devices were examined. Design, performance and LCC dynamic models are developed based on mission and system/subsystem requirements and existing or derived physical and cost data relationships. The models are exercised to define baseline designs and costs. Then the major design and performance parameters are each varied to determine their influence on LCC around the baseline values
Electrochemical energy storage subsystems study, volume 1
The effects on life cycle costs (LCC) of major design and performance technology parameters for multi kW LEO and GEO energy storage subsystems using NiCd and NiH2 batteries and fuel cell/electrolysis cell devices were examined. Design, performance and LCC dynamic models are developed based on mission and system/subsystem requirements and existing or derived physical and cost data relationships. The models define baseline designs and costs. The major design and performance parameters are each varied to determine their influence on LCC around the baseline values
Self-similar impulsive capillary waves on a ligament
We study the short-time dynamics of a liquid ligament, held between two solid
cylinders, when one is impulsively accelerated along its axis. A set of
one-dimensional equations in the slender-slope approximation is used to
describe the dynamics, including surface tension and viscous effects. An exact
self-similar solution to the linearized equations is successfully compared to
experiments made with millimetric ligaments. Another non-linear self-similar
solution of the full set of equations is found numerically. Both the linear and
non-linear solutions show that the axial depth at which the liquid is affected
by the motion of the cylinder scales like . The non-linear solution
presents the peculiar feature that there exists a maximum driving velocity
above which the solution disappears, a phenomenon probably related to
the de-pinning of the contact line observed in experiments for large pulling
velocities
How to fool a virgin: Artificial dealation triggers oviposition in virgin Lasius niger queens
Once inseminated, ant queens rapidly shed their wings and start to lay eggs. Here we test whether there is a causal link between dealation and oviposition in the ant Lasius niger. We show that artificially dealated virgin queens start to lay eggs shortly after wing removal, whereas winged virgin queens hardly ever lay eggs. Dealate virgins do, however, produce fewer eggs than mated queens. These findings indicate that dealation does induce egg-laying, and that other factors, such as mating and/or insemination, further stimulate oviposition under natural conditions
Power systems research at MSFC
Power systems research reviews at Marshall Space Flight Cente
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