The detailed characterization of Martian impact craters from the 1/16 degree MOLA global topography grid

We describe a new project to obtain a global characterisation of Martian impact crater morphology from the 1/16 degree MOLA topography dataset. A new mathematical method applicable to both symmetric and asymmetric craters is used

Evaluation of the volumetric erosion of spherical electrical contacts using the defect removal method

Volumetric erosion is regarded as a significant index for studying the erosion process of electrical switching contacts. Three-dimensional (3-D) surface measurement techniques provide an approach to investigate the geometric characteristics and volumetric erosion of electrical contacts. This paper presents a concrete data-processing procedure for evaluating volumetric erosion of spherical electrical contacts from 3-D surface measurement data using the defect removal method (DRM). The DRM outlined by McBride is an algorithm for evaluating the underlying form (prior to erosion) parameters of the surfaces with localized erosion and allowing the erosion characteristics themselves to be isolated. In this paper, a number of spherical electrical contacts that had undergone various electrical operations were measured using a 3-D surface profiler, the underlying form parameters of the eroded contacts were evaluated using the DRM, and then the volumetric erosions were isolated and calculated. The analysis of the correlations between the volumetric erosion and the number of switching cycles of electrical operation that the contacts had undergone showed a more accurate and reliable volumetric erosion evaluation using the DRM than that without using the DRM

DOES CONTRACTING RAISE FARM PRODUCTIVITY? THE IMPACT OF PRODUCTION CONTRACTS ON HOG FARM PERFORMANCE

The costs and benefits of policies designed to regulate the use of production contracts will depend in part on the impact of these contracts on farm productivity. In this paper we measure the impact of contracting on 1) partial and total factor productivity and 2) the production technology for 479 US hog operations. A sample selection model accounts for the fact that unobservable variables may be correlated with both the decision to contract and farm productivity. Results also identify determinants of farmers' decisions to contract and factors influencing farm productivity.Livestock Production/Industries, Productivity Analysis,

FACTORS AFFECTING CONTRACTOR AND GROWER SUCCESS IN HOG CONTRACTING

This study analyzes a national survey of U.S. hog producers within a principal-agent framework in order to examine factors affecting contractor and grower success in hog contracting. Several factors had differential impacts on contractor and grower returns. Results suggest that there may be a role for public policy in ensuring that contract arrangements are conducted fairly.Livestock Production/Industries,

Impact of the Patient Protection and Affordable Care Act on Covered Persons

Estimates how proposed reforms would affect health insurance coverage rates in each state and what percentage of the newly covered would benefit from provisions for Medicaid, subsidies, mandates, and children. Compares rural and urban areas

The Transformation of U.S. Livestock Agriculture: Scale, Efficiency, and Risks

U.S. livestock production has shifted to much larger and more specialized farms, and the various stages of input provision, farm production, and processing are now much more tightly coordinated through formal contracts and shared ownership of assets. Important financial advantages have driven these structural changes, which in turn have boosted productivity growth in the livestock sector. But structural changes can also generate environmental and health risks for society, as industrialization concentrates animals and animal wastes in localized areas. This report relies on farm-level data to detail the nature, causes, and effects of structural changes in livestock production.Livestock, dairy, broilers, hogs, fed cattle, farm structure, scale economies, contract agriculture, CAFOs, growth-promoting antibiotics, Farm Management, Livestock Production/Industries,

INFORMATION AND THE ADOPTION OF PRECISION FARMING TECHNOLOGIES

Precision farming technologies have been commercially available since the early 1990s, but the pace of adoption among U.S. farmers has been modest. This study examines the relationship between the adoption of diagnostic and application techniques of precision farming and sources of information available to farmers about precision farming. The model used in the analysis accounts for sources of self-selection in the adoption process that could bias the results. Results indicate interpersonal information sources have increased adoption relative to information from the mass media, and the private sector has been the driving force behind the diffusion of precision farming. Information from crop consultants and input suppliers has had the greatest impact on the adoption of precision farming technologies. These sources likely provide the greatest technical expertise about precision farming, and thus are better equipped to ease the significant human capital requirement of precision farming technologies.information sources, logit analysis, precision farming, self-selection bias, technology adoption, Farm Management, Research and Development/Tech Change/Emerging Technologies,

Policy Reform in the Tobacco Industry: Producers Adapt to a Changing Market

The Fair and Equitable Tobacco Reform Act of 2004 eliminated tobacco quotas and tobacco price supports and allowed producers to plant any amount or type of tobacco regardless of geographic location. The authors found that flue-cured tobacco producers made greater adjustments to their operations after the buyout than did burley tobacco producers. Flue-cured tobacco producers were more likely to increase tobacco acres per farm, pushing up the tobacco acreage per farm at a faster rate compared with burley tobacco producers. Flue-cured producers also were more likely to invest in their tobacco enterprises and invested more per farm after 2004. As a result of increased acreage, tobacco operations became more sensitive to changes in labor costs. With over 75 percent of tobacco farms using hired or contract labor in 2008, the availability and cost of workers have become increasingly important to tobacco producers. This report is based on data collected from the tobacco version of the 2008 Agricultural Resource Management Survey (ARMS), which focused on U.S. producers of burley and flue-cure tobacco in 2008 and how their tobacco operations have changed since 2000 and 2004.Tobacco, structural change, farm adjustments, adaptations, Agricultural Resources Management Survey (ARMS) Acknowledgments, Agricultural and Food Policy, Crop Production/Industries, Farm Management,

Changes in Manure Management in the Hog Sector

In recent years, structural changes in the hog sector, including increasing farm size and regional shifts in production, have altered manure management practices. Over the same period, changes to the Clean Water Act, new state regulations, and increasing local conflicts over odor have influenced manure management decisions. This study uses data from two national surveys of hog farmers to examine how hog manure management practices vary with the scale of production and how these practices evolved between 1998 and 2004. The findings provide insights into the effects of structural changes and recent policies on manure management technologies and practices, the use of nutrient management plans, and manure application rates.hog production, manure management, structural change, environmental regulation, Livestock Production/Industries,