Evaluation of rotating-cylinder and piston-cylinder reactors for ground-based emulsion polymerization

The objectives of this program are to apply ground-based emulsion polymerization reactor technology to improve the production of: monodisperse latex particles for calibration standards, chromatographic separation column packing, and medical research; and commercial latexes such as those used for coatings, foams, and adhesives

Process for preparation of large-particle-size monodisperse latexes

Monodisperse latexes having a particle size in the range of 2 to 40 microns are prepared by seeded emulsion polymerization in microgravity. A reaction mixture containing smaller monodisperse latex seed particles, predetermined amounts of monomer, emulsifier, initiator, inhibitor and water is placed in a microgravity environment, and polymerization is initiated by heating. The reaction is allowed to continue until the seed particles grow to a predetermined size, and the resulting enlarged particles are then recovered. A plurality of particle-growing steps can be used to reach larger sizes within the stated range, with enlarge particles from the previous steps being used as seed particles for the succeeding steps. Microgravity enables preparation of particles in the stated size range by avoiding gravity related problems of creaming and settling, and flocculation induced by mechanical shear that have precluded their preparation in a normal gravity environment

Production of large-particle-size monodisperse latexes

The research program achieved two objectives: (1) it has refined and extended the experimental techniques for preparing monodisperse latexes in quantity on the ground up to a particle diameter of 10 microns; and (2) it has demonstrated that a microgravity environment can be used to grow monodisperse latexes to larger sizes, where the limitations in size have yet to be defined. The experimental development of the monodisperse latex reactor (MLR) and the seeded emulsion polymerizations carried out in the laboratory prototype of the flight hardware, as a function of the operational parameters is discussed. The emphasis is directed towards the measurement, interpretation, and modeling of the kinetics of seeded emulsion polymerization and successive seeded emulsion polymerization. The recipe development of seeded emulsion polymerization as a function of particle size is discussed. The equilibrium swelling of latex particles with monomers was investigated both theoretically and experimentally. Extensive studies are reported on both the type and concentration of initiators, surfactants, and inhibitors, which eventually led to the development of the flight recipes. The experimental results of the flight experiments are discussed, as well as the experimental development of inhibition of seeded emulsion polymerization in terms of time of inhibition and the effect of inhibitors on the kinetics of polymerization

The Effect of Relative Pricing on the Fixed-Rate Mortgage Term Decision

This paper analyzes determinants of the fifteen- versus thirty-year fixed-rate mortgage (FRM) loan term decision. Because the thirty-year FRM may be converted (by partial prepayment) to the shorter term, the thirty-year instrument provides the implicit option to extend repayment. Relative rates measure the price (cost) of this option to the consumer. The results indicate that the term decision of consumers is highly sensitive to relative rates: probit estimates using data from a large national lending institution for the 1987 to 1990 period indicate that a 1% increase in the ratio of fifteen- to thirty-year rates lowers the probability of fifteen-year term choice by 20%. The results also indicate that expected housing price appreciation, which measures investment determinants of housing demand, is negatively related to the fifteen-year FRM term choice.

The first products made in space: Monodisperse latex particles

The preparation of large particle size 3 to 30 micrometer monodisperse latexes in space confirmed that original rationale unequivocally. The flight polymerizations formed negligible amounts of coagulum as compared to increasing amounts for the ground-based polymerizations. The number of offsize large particles in the flight latexes was smaller than in the ground-based latexes. The particle size distribution broadened and more larger offsize particles were formed when the polymerizations of the partially converted STS-4 latexes were completed on Earth. Polymerization in space also showed other unanticipated advantages. The flight latexes had narrower particle size distributions than the ground-based latexes. The particles of the flight latexes were more perfect spheres than those of the ground-based latexes. The superior uniformity of the flight latexes was confirmed by the National Bureau of Standards acceptance of the 10 micrometer STS-6 latex and the 30 micrometer STS-11 latexes as Standard Reference Materials, the first products made in space for sale on Earth. The polymerization rates in space were the same as those on Earth within experimental error. Further development of the ground-based polymerization recipes gave monodisperse particles as large as 100 micrometer with tolerable levels of coagulum, but their uniformity was significantly poorer than the flight latexes. Careful control of the polymerization parameters gave uniform nonspherical particles: symmetrical and asymmetrical doublets, ellipsoids, egg-shaped, ice cream cone-shaped, and popcorn-shaped particles

Standardized process improvement for natural resources management decisions to better serve the public

The goal of this project was to present Executive Management with a practical, cost-effective, and standardized system to prioritize requests, monitor, and report on project expenditures from these highly sensitive funding areas. It is perceived that if we can meet the needs of our ultimate end-users, the citizens of the state, and provide them with easily accessible and enjoyable natural resources habitats, then we have successfully met our mission and vision for the agency

Multiple Storm Event Impacts on Epikarst Storage and Transport of Organic Soil Amendments in South-Central Kentucky

The groundwater in agricultural karst areas is susceptible to contamination from organic soil amendments and pesticides. During major storm events during 2011, dye traces were initiated using sulphorhodamine-B, fluorescein and eosine in a groundwater recharge area where manure was applied to the ground. Fecal coliform samples were collected from significant storm events from January-September 2011. Water samples and geochemical data were collected every four hours before, during, and between the storm events from a waterfall in Crumps cave flowing from the known recharge area to track the transport and residence time of the epikarst water and organic soil amendments during variable flow conditions. Two dataloggers at the same waterfall were set up to collect 10-minute data, which included pH, specific conductivity, temperature, and discharge. Total rainfall amount and other surface meteorological data were collected from a rain station located above the cave. Cave water samples were collected for the analysis of anions, cations, bacterial count, and the presence of dye. The dye traces show variability in the characteristics of epikarstic response and flowpaths. The changes in geochemistry indicate simultaneous storage and transport of meteoric water through epikarst pathways into the cave, with rapid transport of bacteria occurring through the conduits that bypass storage. Fecal coliform counts were elevated all through the study period indicating survivability in soils through the seasons. The results indicate that significant precipitation events affect the storage properties and rapidly impact the various pathways and timing of contaminant transport through the epikarst zone, eventually allowing these contaminants to be transported unfiltered in to the groundwater supply. This study shows that current best management practices in karst lands need to be revisited to incorporate areas that do not have surface runoff but where contaminants are transported by seepage into local aquifer

Strategies for DDGS Supplementation Frequency to Frazing Yearling Streers

Infrequent supplementation saves labor and may reduce animal performance, but recent research with reduced fat distillers grains has provided inconsistent results. This experiment evaluated the effects of daily and three times a week supplementation of dried distillers grains on yearling steer performance grazing smooth bromegrass pastures from May to August. Daily supplemented steers received 5.6 pounds of dry matter per steer of dried distillers grains with solubles 7 days/week. The three times a week supplemented steers received 13.0 pounds of dry matter per steer of dried distillers grains with solubles three days/week (Monday, Wednesday, Friday). A control treatment received no supplementation. Providing distillers grains supplement increased gain by 0.89 pounds per day compared to non-supplemented cattle. Daily supplementation of dried distillers grains increases gain by 0.31 pounds per day compared to three times a week supplementation and a non-supplemented control. Supplementing distillers gains three times per week may reduce ADG by 10% compared to daily supplementation

Interaction of Backgrounding System and Implant Use on Growing Calf Performance

Summary with Implications A two-year study utilized 480 weaned steers each year targeted to gain either 1 or 2 lb/d during the winter followed by ad libitum forage intake during the summer to determine the effects of winter rate of gain and implant strategy during the winter backgrounding and summer phases on steer performance, forage intake, and compensatory gain. During the winter, steers received a Revalor-G or no implant. In the summer, steers either received a Revalor-IS or no implant. The use of Revalor-G and increased rate of gain during the winter backgrounding phase had additive effects to increase animal performance during the winter phase. Steers which achieved a lower rate of gain in the winter consumed more DMI as a % of their BW during the summer phase, suggesting increased intake is an important compensation mechanism. On average, steers fed to target 1 lb/d ADG during the winter and only received one implant throughout both the winter and summer phases compensated 22% during the summer while steers receiving 2 implants compensated 9% compared to steers fed to target 2 lb/d during the winter. Use of implants during the backgrounding phase is a viable strategy to improve animal performance and limit subsequent losses in performance due to compensation