The PIT MkV pulsed inductive thruster

The pulsed inductive thruster (PIT) is an electrodeless, magnetic rocket engine that can operate with any gaseous propellant. A puff of gas injected against the face of a flat (spiral) coil is ionized and ejected by the magnetic field of a fast-rising current pulse from a capacitor bank discharge. Single shot operation on an impulse balance has provided efficiency and I(sub sp) data that characterize operation at any power level (pulse rate). The 1-m diameter MkV thruster concept offers low estimated engine mass at low powers, together with power capability up to more than 1 MW for the 1-m diameter design. A 20 kW design estimate indicates specific mass comparable to Ion Engine specific mass for 10,000 hour operation, while a 100,000 hour design would have a specific mass 1/3 that of the Ion Engine. Performance data are reported for ammonia and hydrazine. With ammonia, at 32 KV coil voltage, efficiency is a little more than 50 percent from 4000 to more than 8000 seconds I(sub sp). Comparison with data at 24 and 28 kV indicates that a wider I(sub sp) range could be achieved at higher coil voltages, if required for deep space missions

A Study of the \u3cem\u3eAmerican Druggist\u3c/em\u3e the \u3cem\u3eDry Goods Economist\u3c/em\u3e and the \u3cem\u3eMerchandise Manager\u3c/em\u3e Magazines

The purpose of this thesis was to make a study of three quality trade publications in order to learn just what type of material each one uses, what some of their differences are and the various ways in which they attempt to gain and hold reader interest. The magazines surveyed were the American Druggist, the Merchandise Manager and the Dry Goods Economist

Integrated propulsion for near-Earth space missions. Volume 1: Executive summary

Tradeoffs between electric propulsion system mass ratio and transfer time from LEO to GEO were conducted parametrically for various thruster efficiency, specific impulse, and other propulsion parameters. A computer model was developed for performing orbit transfer calculations which included the effects of aerodynamic drag, radiation degradation, and occultation. The tradeoff results showed that thruster technology areas for integrated propulsion should be directed towards improving primary thruster efficiency in the range from 1500 to 2500 seconds, and be continued towards reducing specific mass. Comparison of auxiliary propulsion systems showed large total propellant mass savings with integrated electric auxiliary propulsion. Stationkeeping is the most demanding on orbit propulsion requirement. At area densities above 0.5 sq m/kg, East-West stationkeeping requirements from solar pressure exceed North-South stationkeeping requirements from gravitational forces. A solar array pointing strategy was developed to minimize the effects of atmospheric drag at low altitude, enabling electric propulsion to initiate orbit transfer at Shuttle's maximum cargo carrying altitude. Gravity gradient torques are used during ascent to sustain the spacecraft roll motion required for optimum solar array illumination. A near optimum cover glass thickness of 6 mils was established for LEO to GEO transfer

Integrated propulsion for near-Earth space missions. Volume 2: Technical

The calculation approach is described for parametric analysis of candidate electric propulsion systems employed in LEO to GEO missions. Occultation relations, atmospheric density effects, and natural radiation effects are presented. A solar cell cover glass tradeoff is performed to determine optimum glass thickness. Solar array and spacecraft pointing strategies are described for low altitude flight and for optimum array illumination during ascent. Mass ratio tradeoffs versus transfer time provide direction for thruster technology improvements. Integrated electric propulsion analysis is performed for orbit boosting, inclination change, attitude control, stationkeeping, repositioning, and disposal functions as well as power sharing with payload on orbit. Comparison with chemical auxiliary propulsion is made to quantify the advantages of integrated propulsion in terms of weight savings and concomittant launch cost savings

Oak Lake Wetland Restoration: Difference in Hydrology between Newly Restored and Reference Wetlands

https://openprairie.sdstate.edu/oak-lake_presentations/1001/thumbnail.jp

A report to The Ozarks Regional Commission

"Changes in demographic processes are occurring in the Ozarks Region. Some metropolitan areas are experiencing a decrease in growth and, in a few, population decline. In conjunction with this, the reversal of non-metropolitan population loss and out-migration is becoming visible in major portions of the region. The level of natural increase, births minus deaths, is dropping in response to lower birth rates in some areas and to a heavy concentration of older persons in others. In order to comprehend these changes in the Ozarks Region it must be understood that the region is made up of five diverse states. (For regional boundary definitions, see Figures 1 and 2.) Within each are a variety of physiographic sub-regions with their individual economic distinctions. In constructing any social profile of the states it would become quite obvious that an array of such profiles would be produced. So also is the case in describing demographic change in the region. While an overview of the region provides a total picture, it tends to obscure variations on a state or sub-regional basis. Thus, an overview for all five states is first provided, followed by a description for each state, which incorporates sub-regional information. In exploring these demographic components of change an examination is made of the emergence of new patterns and the continuation of old ones. In addition, an effort is made to point out some of the factors associated with these processes and to place these factors in a national perspective." --Introduction.Rex R. Campbell, George H. Dailey, Jr., Robert L. McNamara (Deportment of Rural Sociology University of Missouri-Columbia

Bridging the ICT4D Design-Actuality Gap: “Human ATMs” and the Provision of Financial Services for “Humble People”

Most challenges in ICT for development (ICT4D) projects can be related to differences in perceptions of systems developers and their actual users. Such design-actuality gaps exist both because designers take an uninformed stance towards the user context, and also because problems that ICT4D projects address are nested in systems whose interplay is nearly impossible to predict. Although gaps are inevitable, users are not passive recipients whose only choices are to accept shortfalls in design or reject ICT4D technologies. Rather, users may act to remedy shortfalls through system work-arounds. In this paper we investigate the design use gap in the Brazilian correspondent banking model, an ICT4D project in which local small businesspeople interact with social, financial, government, and technical systems to provide financial services mostly for poor populations. Our findings suggest that correspondents’ acts to alter the financial and social systems proved sufficient to permit success of the project. Our results point to the importance of taking into account user actions and the separate roles of individual systems when designing ICT4D projects and theorizing their performance

Gonadotropin Concentrations, Follicular Development, and Luteal Function in Pituitary Stalk-transfected Ewes Treated with Bovine Follicular Fluid

Two experiments, each arranged as a 2 x 2 factorial, were conducted in ewes to examine direct effects of bovine follicular fluid (bFF) on follicular development and luteal function and to further characterize follicular development and luteal function after pituitary stalk transection (SS). In Exp. 1, ewes were sham-operated or SS on d 6 of an estrous cycle and received 5 ml of saline or bFF three times daily on d 5 through 11 of the same cycle. In Exp. 2, all ewes were SS on d 6 of an estrous cycle and treated with saline or bFF three times daily on d 5 through 11 and with ovine FSH (60 micrograms; NIADDK-oFSH-16) or saline (1.2 ml) from d 7 to 11. In Exp. 2, ewes were ovariectomized on d 11 to assess effects of treatments on follicular development and luteal function. In both experiments, concentrations (ng/ml) of FSH on d 7 were suppressed (P less than or equal to .005) by bFF compared with saline (.50 +/- .17 vs 1.63 +/- .15) and remained suppressed (P less than or equal to .005) through d 11 (.46 +/- .12 vs 1.54 +/- .12). Replacement therapy (oFSH) restored concentrations of FSH. Concentrations of LH were not affected by bFF but were elevated (P less than or equal to .05) 1 d after SS (d 7; .88 +/- .09 vs .56 +/- .09) and remained elevated (P less than or equal to .05; 1.31 +/- .20 vs .65 +/- .11) from d 6 through 11. Concentrations of progesterone were unaffected by SS

Comparison of low back fusion techniques: transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody fusion (PLIF) approaches

The authors review and compare posterior lumbar interbody fusion (PLIF) with transforaminal lumbar interbody fusion (TLIF). A review of the literature is performed wherein the history, indications for surgery, surgical procedures with their respective biomechanical advantages, potential complications, and grafting substances are presented. Along with the technical advancements and improvements in grafting substances, the indications and use of PLIF and TLIF have increased. The rate of arthrodesis has been shown to increase given placement of bone graft along the weight-bearing axis. The fusion rate across the disc space is further enhanced with the placement of posterior pedicle screw–rod constructs and the application of an osteoinductive material. The chief advantages of the TLIF procedure compared with the PLIF procedure included a decrease in potential neurological injury, improvement in lordotic alignment given graft placement within the anterior column, and preservation of posterior column integrity through minimizing lamina, facet, and pars dissection

Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science

The Wide-field Infrared Survey Explorer (WISE) has surveyed the entire sky at four infrared wavelengths with greatly improved sensitivity and spatial resolution compared to its predecessors, the Infrared Astronomical Satellite and the Cosmic Background Explorer. NASA's Planetary Science Division has funded an enhancement to the WISE data processing system called "NEOWISE" that allows detection and archiving of moving objects found in the WISE data. NEOWISE has mined the WISE images for a wide array of small bodies in our solar system, including near-Earth objects (NEOs), Main Belt asteroids, comets, Trojans, and Centaurs. By the end of survey operations in 2011 February, NEOWISE identified over 157,000 asteroids, including more than 500 NEOs and ~120 comets. The NEOWISE data set will enable a panoply of new scientific investigations