CHINA'S ACCESSION TO WTO: IMPLICATIONS FOR US AGRICULTURAL EXPORTS

Agricultural and Food Policy,

Development of improved amorphous materials for laser systems

Crystallization calculations were performed in order to determine the possibility of forming a particular type of laser glass with the avoidance of devitrification in an outer space laboratory. It was demonstrated that under the homogenuous nucleating conditions obtainable in a zero gravity laboratory this laser glass may be easily quenched to a virtually crystal-free product. Experimental evidence is provided that use of this material as a host in a neodymium glass laser would result in more than a 10 percent increase in efficiency when compared to laser glass rods of a similar composition currently commercially available. Differential thermal analysis, thermal gradient oven, X-ray diffraction, and liquidus determination experiments were carried out to determine the basics of the crystallization behavior of the glass, and small-angle X-ray scattering and splat-cooling experiments were performed in order to provide additional evidence for the feasibility of producing this laser glass material, crystal free, in an outer space environment

The 20th Century Transformation of U.S. Agriculture and Farm Policy

The structure of farms, farm households, and the rural communities in which they exist has evolved markedly over the last century. Historical data on a range of farm structure variables—including the value of agricultural production, commodity specialization, farming-dependent counties, and off-farm work—offer a perspective on the long-term forces that have helped shape the structure of agriculture and rural life over the past century. These forces include productivity growth, the increasing importance of national and global markets, and the rising influence of consumers on agricultural production. Within this long-term context of structural change, a review of some key developments in farm policy considers the extent to which farm policy design has or has not kept pace with the continuing transformation of American agriculture.farm policy, farm structure, policy adjustment, structural adjustment, mechanization, productivity growth, global markets, consumer stakeholders, price and income support, farm policy history, Agricultural and Food Policy, Farm Management,

Cepheid limb darkening, angular diameter corrections, and projection factor from static spherical model stellar atmospheres

Context. One challenge for measuring the Hubble constant using Classical Cepheids is the calibration of the Leavitt Law or period-luminosity relationship. The Baade-Wesselink method for distance determination to Cepheids relies on the ratio of the measured radial velocity and pulsation velocity, the so-called projection factor and the ability to measure the stellar angular diameters. Aims. We use spherically-symmetric model stellar atmospheres to explore the dependence of the p-factor and angular diameter corrections as a function of pulsation period. Methods. Intensity profiles are computed from a grid of plane-parallel and spherically-symmetric model stellar atmospheres using the SAtlas code. Projection factors and angular diameter corrections are determined from these intensity profiles and compared to previous results. Results. Our predicted geometric period-projection factor relation including previously published state-of-the-art hydrodynamical predictions is not with recent observational constraints. We suggest a number of potential resolutions to this discrepancy. The model atmosphere geometry also affects predictions for angular diameter corrections used to interpret interferometric observations, suggesting corrections used in the past underestimated Cepheid angular diameters by 3 - 5%. Conclusions. While spherically-symmetric hydrostatic model atmospheres cannot resolve differences between projection factors from theory and observations, they do help constrain underlying physics that must be included, including chromospheres and mass loss. The models also predict more physically-based limb-darkening corrections for interferometric observations.Comment: 8 pages, 6 figures, 2 tables, accepted for publication in A&

Pulsation Period Change & Classical Cepheids: Probing the Details of Stellar Evolution

Measurements of secular period change probe real-time stellar evolution of classical Cepheids making these measurements powerful constraints for stellar evolution models, especially when coupled with interferometric measurements. In this work, we present stellar evolution models and measured rates of period change for two Galactic Cepheids: Polaris and l Carinae, both important Cepheids for anchoring the Cepheid Leavitt law (period-luminosity relation). The combination of previously-measured parallaxes, interferometric angular diameters and rates of period change allows for predictions of Cepheid mass loss and stellar mass. Using the stellar evolution models, We find that l Car has a mass of about 9 $M_\odot$ consistent with stellar pulsation models, but is not undergoing enhanced stellar mass loss. Conversely, the rate of period change for Polaris requires including enhanced mass-loss rates. We discuss what these different results imply for Cepheid evolution and the mass-loss mechanism on the Cepheid instability strip.Comment: 2 pages, 1 figure, Poster presented at IAU307: New windows on massive stars: asteroseismology, interferometry, and spectropolarimetry, Editors: G. Meynet, C. Georgy, J.H. Groh & Ph. Ste

The Stars Kept Shining: The Wartime Diary of Esther Mathilda Sørensen

In fulfillment of the Liberty University Honors Department Thesis requirement, the following is a creative thesis in the form of an historical fiction novella diary, written in the first person. The story follows the life of Esther, a young Danish woman, as she navigates what it means to be a Jew in World War II era Europe. Though the characters are fictional, the story presents possible real-life experiences for a person living during this time. The style of this novella is popular among middle and high school teachers and can be an important teaching tool as it is an engaging way for students to learn about a period in history. The diary form lends a real-life and personal feel which is relatable to children of similar ages. The experience of Jews in Denmark during the Holocaust is unlike any other of the European countries. Denmark had a very small Jewish community, approximately 8,000 at the start of the war, and roughly 99% of them survived. While the majority of European Jews perished during the years of 1939-1945, the gravity of the situation in Denmark is remarkable. Even though Denmark is considered to have collaborated with the Nazi regime, they resisted in many ways, not least in her work in saving almost her entire Jewish population

POLICY DEVELOPMENTS IN UNITED STATES AGRICULTURE SINCE 1986

Agricultural and Food Policy,