Microporous structure with layered interstitial surface treatment, and method and apparatus for preparation thereof

A microporous structure with layered interstitial surface treatments, and the method and apparatus for its preparation are disclosed. The structure is prepared by sequentially subjecting a uniformly surface treated structure to atomic oxygen treatment to remove an outer layer of surface treatment to a generally uniform depth, and then surface treating the so exposed layer with another surface treating agent. The atomic oxygen/surface treatment steps may optionally be repeated, each successive time to a lesser depth, to produce a microporous structure having multilayered surface treatments. The apparatus employs at least one side arm from a main oxygen-containing chamber. The side arm has characteristic relaxation times such that a uniform atomic oxygen dose rate is delivered to a specimen positioned transversely in the side arm spaced from the main gas chamber

Atomic oxygen effects on spacecraft materials: The state of the art of our knowledge

In the flight materials exposure data base extensive quantitative data is available from limited exposures in a narrow range of orbital environments. More data is needed in a wider range of environments as well as longer exposure times. Synergistic effects with other environmental factors; polar orbit and higher altitude environments; and real time materials degradation data is needed to understand degradation kinetics and mechanism. Almost no laboratory data exists from high fidelity simulations of the LEO environment. Simulation and test system are under development, and the data base is scanty. Theoretical understanding of hyperthermal atom surface reactions in the LEO environment is not good enough to support development of reliable accelerated test methods. The laser sustained discharge, atom beam sources are the most promising high fidelity simulation-test systems at this time

MEAT-PACKER CONDUCT IN FED CATTLE PRICING: MULTIPLE-MARKET OLIGOPSONY POWER

The exercise of market power across multiple geographic fed cattle markets is measured with an econometric model which links behavior of the margin between boxed beef and regional fed cattle prices to an oligopsony model of multiple-market conduct. The game theoretic economic model suggests that for market power to be exercised in a single market a discontinuous pricing strategy must be followed. Total market power is enhance if meat-packers coordinate this pricing strategy across geographic markets. Tests reject independence of pricing conduct across geographic markets which suggests multiple-market power is present. The extent of the market power also is consistent with the economic model. More market power is exercised across regions with the same meat-packing firms. However, the magnitude of the market power is small and decreased between the early and late 1980s.Demand and Price Analysis,

AIROscope: Ames infrared balloon-borne telescope

A balloon-borne telescope system designed for astronomical observations at infrared wavelengths is discussed. The telescope is gyro-stabilized with updated pointing information derived from television, star tracker, or ground commands. The television system furnishes both course and fine acquisition after initial orientation using a pair of fluxgate servo compasses. Command and control is by a UHF link with 256 commands available. Scientific and engineering data are telemetered to the ground station via narrow band F.M. in the L band. The ground station displays all scientific, engineering and status information during the flights and records the command and telemetry digital bit stream for detailed analysis. The AIROscope telescope has a 28-inch diameter primary mirror and Dall-Kirkham optics. The beam is modulated by oscillating a secondary mirror at 11 or 25 Hz with provision for left or right beam fixed positions by command

An investigation of the behavior of outgassed molecules in thermal vacuums

The objective is to understand how surfaces outgas and how outgassed substances subsequently condense on other surfaces. Preliminary tests produced calculated mass losses that were found to be in reasonable agreement with mass losses determined by weighing the sample before and after testing on analytical balances. However, using test materials with various molecular properties showed characteristic variations in the ratios of calculated total mass loss to experimental loss. These variations indicate that for some molecules energetic barriers to absorption and desorption can exist between outgassed molecules and the surfaces on which they condense

ELECTRONIC MARKET USE BY OKLAHOMA LAMB PRODUCERS

Socioeconomic and production system characteristics of a sample of Oklahoma sheep producers were employed to examine the decision to use or not use an electronic market for slaughter lambs. Producer attributes that influence electronic market use were identified with qualitative choice models. The results help identify characteristics of electronic markets which influence their success. The findings also have implications about educational opportunities for cooperative extension.Livestock Production/Industries, Marketing,

Beta cloth durability assessment for Space Station Freedom (SSF) Multi-Layer Insulation (MLI) blanket covers

MLI blankets for the Space Station Freedom (SSF) must comply with general program requirements and recommendations for long life and durability in the low-Earth orbit (LEO) environment. Atomic oxygen and solar ultraviolet/vacuum ultraviolet are the most important factors in the SSF natural environment which affect materials life. Two types of Beta cloth (Teflon coated woven glass fabric), which had been proposed as MLI blanket covers, were tested for long-term durability in the LEO environment. General resistance to atomic oxygen attack and permeation were evaluated in the high velocity atomic oxygen beam system at Los Alamos National Laboratories. Long-term exposure to the LEO environment was simulated in the laboratory using a radio frequency oxygen plasma asher. The plasma asher treated Beta cloth specimens were tested for thermo-optical properties and mechanical durability. Space exposure data from the Long Duration Exposure Facility and the Intelsat Solar Array Coupon were also used in the durability assessment. Beta cloth fabricated to Rockwell specification MBO 135-027 (Chemglas 250) was shown to have acceptable durability for general use as an MLI blanket cover material in the LEO environment while Sheldahl G414500 should be used only in locations which are protected from direct Ram atomic oxygen

Bible Translators, Educators, and Suffragists: The Smith Women, a Nineteenth-Century Case Study in America About Power, Agency, and Subordination

The methodological approach used to tell the Smith sisters’ story is first and foremost a case study of women in the nineteenth century and the gendered categories that were constructed to define women. The story will be told through a biographical narrative, which will allow Hannah, Julia, and Abby Smith’s to tell their story in their own voice. Also, included within the biography is an examination of the nineteenth-century theories that defined women’s lives, and what effect, if any, these theories had on the Smiths. Each chapter is layered with three different narratives in an attempt to unravel the world that women lived in the nineteenth century. First, the chapter provides a description and analysis of the specific theories such as Republican Motherhood and cult of domesticity to ground the Smith women in the discursive world in which they lived. Then the chapter closely examines the practice or the way the Smith women lived their lives and what they thought about their world. Lastly, each chapter explores the secondary sources that have been written about each subject, such as the new female seminaries that opened in the nineteenth century. By combining these approaches, I hope to avoid some of the shortcomings that dominate the study of women today. First, the theoretical models and the study of real lives of women actually leave women out of their own stories. Second, historians tend to evaluate women’s lives from the past based upon their own political agendas and their own beliefs of what freedom and rights mean completely discarding what it might have meant to women in their own time period

CHARACTERIZATION OF STRUCTURAL RELAXATION IN INORGANIC GLASSES USING LENGTH DILATOMETRY

Structural relaxation in inorganic glasses is a phenomenon of much study in the glass community. The processes that govern how a glass relaxes towards its thermodynamic quasi-equilibrium state are major factors in understanding glass behavior near the glass transition region, as characterized by the glass transition temperature (Tg). Study of the glass transition has been going for as long as glass science has been a field and much of the cutting edge literature published in glass science today relates to it in some way. Intrinsic glass properties such as specific volume, enthalpy, entropy, density, etc. are used to map the behavior of the glass network below in and near the transition region. The question of whether a true thermodynamic second order phase transition takes place in the glass transition region is another pending question in the glass community. Linking viscosity behavior to entropy as Adam and Gibbs did, or viewing the glass configuration as an energy landscape are just a couple of the most prevalent methods used for attempting to understand the glass transition.[1,2] The structural relaxation behavior of inorganic glasses is important for more than scientific reasons, many commercial glass processing operations including glass melting and certain forms of optical fabrication include significant time spent in the glass transition region. For this reason knowledge of structural relaxation processes can, at a minimum, provide information for annealing duration of melt-quenched glasses. The development of a predictive model for annealing time prescription has the potential to save glass manufacturers significant time and money as well as increasing volume throughput. In optical hot forming processes such as precision glass molding, molded optical components can significantly change in shape upon cooling through the glass transition. This change in shape is not scientifically predictable as of yet though manufacturers typically use empirical rules developed in house. The classification of glass behavior in the glass transition region would allow molds to be accurately designed and save money for the producers