Macroeconomic Impacts of Water Use in Agriculture

The recent/current recession provides the opportunity to study the effects of the macroeconomic changes on the agricultural production systems in the Great Plains and trace some of its impacts through the system to changes in primary inputs such water resource use. Therefore, the objective of the study reported here was to determine the effects of the changes in macroeconomic conditions driven by the 2008 recession on irrigated crop production in a portion of the Southern Great Plains and its impacts on water use. The approach for the study was to: (1) use the 10-year baseline FAPRI projections, based on changes in macroeconomic conditions, of agricultural commodity prices and input costs between the beginning of 2008 and the beginning of 2009, and (2) apply these different conditions within the Southern High Plains Ogallala Model (OM) in three counties representing different water situations and cropping patterns in the region. Overall results indicate that the 2008 recession likely had a relatively small impact on water use in the Southern Great Plains. Water use within the region is responsive to economic forces only when increased pumping flexibility exists; when water withdrawals are already at or near capacity, macroeconomic changes and changes in pumping costs and commodity prices are not likely to change water use.Ogallala Aquifer, recession, macroeconomic, Crop Production/Industries, Demand and Price Analysis, Environmental Economics and Policy, Land Economics/Use, Production Economics, Resource /Energy Economics and Policy, E00, Q15, Q30, Q31,

Megawatt solar power systems for lunar surface operations

Lunar surface operations require habitation, transportation, life support, scientific, and manufacturing systems, all of which require some form of power. As an alternative to nuclear power, the development of a modular one megawatt solar power system is studied, examining both photovoltaic and dynamic cycle conversion methods, along with energy storage, heat rejection, and power backup subsystems. For photovoltaic power conversion, two systems are examined. First, a substantial increase in photovoltaic conversion efficiency is realized with the use of new GaAs/GaSb tandem photovoltaic cells, offering an impressive overall array efficiency of 23.5 percent. Since these new cells are still in the experimental phase of development, a currently available GaAs cell providing 18 percent efficiency is examined as an alternate to the experimental cells. Both Brayton and Stirling cycles, powered by linear parabolic solar concentrators, are examined for dynamic cycle power conversion. The Brayton cycle is studied in depth since it is already well developed and can provide high power levels fairly efficiently in a compact, low mass system. The dynamic conversion system requires large scale waste heat rejection capability. To provide this heat rejection, a comparison is made between a heat pipe/radiative fin system using advanced composites, and a potentially less massive liquid droplet radiator system. To supply power through the lunar night, both a low temperature alkaline fuel cell system and an experimental high temperature monolithic solid-oxide fuel cell system are considered. The reactants for the fuel cells are stored cryogenically in order to avoid the high tankage mass required by conventional gaseous storage. In addition, it is proposed that the propellant tanks from a spent, prototype lunar excursion vehicle be used for this purpose, therefore resulting in a significant overall reduction in effective storage system mass

Precision Linear Actuator for Space Interferometry Mission (SIM) Siderostat Pointing

'SIM PlanetQuest will exploit the classical measuring tool of astrometry (interferometry) with unprecedented precision to make dramatic advances in many areas of astronomy and astrophysics'(1). In order to obtain interferometric data two large steerable mirrors, or Siderostats, are used to direct starlight into the interferometer. A gimbaled mechanism actuated by linear actuators is chosen to meet the unprecedented pointing and angle tracking requirements of SIM. A group of JPL engineers designed, built, and tested a linear ballscrew actuator capable of performing submicron incremental steps for 10 years of continuous operation. Precise, zero backlash, closed loop pointing control requirements, lead the team to implement a ballscrew actuator with a direct drive DC motor and a precision piezo brake. Motor control commutation using feedback from a precision linear encoder on the ballscrew output produced an unexpected incremental step size of 20 nm over a range of 120 mm, yielding a dynamic range of 6,000,000:1. The results prove linear nanometer positioning requires no gears, levers, or hydraulic converters. Along the way many lessons have been learned and will subsequently be shared

Fitting the Pieces Together: A Machine-Checked Model of Safe Composition

ABSTRACT Programs of a software product line can be synthesized by composing features which implement a unit of program functionality. In most product lines, only some combination of features are meaningful; feature models express the highlevel domain constraints that govern feature compatibility. Product line developers also face the problem of safe composition -whether every product allowed by a feature model is type-safe when compiled and run. To study the problem of safe composition, we present Lightweight Feature Java (LFJ), an extension of Lightweight Java with support for features. We define a constraint-based type system for LFJ and prove its soundness using a full formalization of LFJ in Coq. In LFJ, soundness means that any composition of features that satisfies the typing constraints will generate a well-formed LJ program. If the constraints of a feature model imply these typing constraints then all programs allowed by the feature model are type-safe

Visual inspection reliability for composite aircraft structures

This thesis presents a study of the effects of surface colour, surface finish and dent shape on the visual inspection reliability of 3D surface indentations common in shape to those produced by impact damage to carbon fibre reinforced epoxy laminates. Falling weight (2.5kg) apparatus was used to produce impact damage to non-painted, non-mesh Hexcel AS4/ 8552 carbon fibre reinforced plastic (CFRP) laminates and painted AS4/ 8552 laminates containing bronze mesh and glass fabric lightning strike protection layers. Ø20 mm and Ø87 mm hemispherical tip impacts to painted 17ply and 33ply laminates at varying energy levels typically produced circular shaped, smoothly contoured, rounded sectional profiles with an absence of surface breaking cracks. Sectional profiles through coordinate measuring (CMM) data of the impact dents were described using a set of geometric variables. Identifying relationships between impact energy and the geometric variables allowed the typical sectional profile through impact damage dents from Ø20 mm and Ø87 mm hemispherical tips on 17ply and 33ply painted CFRP laminates to be calculated for energies between 5J to 80J. Calculated sectional profiles typical of impact damage dents to CFRP laminates were reconstructed as simple revolved shapes using 3D computer aided design (CAD) models. The 3D CAD models were computer numerical control (CNC) machined into 3mm Plexiglas panels to produce facsimiles of hemispherical impact damage dents on CFRP laminates. Facsimile specimen sets of sixteen 600 mm x 600 mm panels were produced in gloss and matt grey, white and blue finishes. Each set contained the same 32 different sized machined dents representing Ø20 mm and Ø87 mm hemispherical tip impact damage to 17ply & 33ply painted CFRP laminate. Each facsimile specimen set was combined with similarly finished unflawed (dent free) panels. 64 panels in each colour/ finish were presented for 5 seconds in a randomised order to a minimum of 15 novice participants in a visual inspection task lasting approximately 25 minutes. II A set of corresponding visual inspection experiments were performed in which physical specimens were replaced by digitally projected actual size photorealistic images of the machining CAD data. Comparisons between the results of the physical and virtual specimen trials revealed differences in detectability for similarly sized dents. The detection results obtained from visual inspection of physical specimens demonstrated that the detectability of dents similar to those caused by higher (>40J) energy impacts from a Ø87 mm hemispherical tip was less than that of the dents caused by lower energy (90% detection were observed on grey specimens and the highest number of dents returning 0% detection were observed on matt blue specimens. The difference in detection rates for similarly sized dents on a gloss and matt finish was least on grey coloured specimens and greatest on blue coloured specimens.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The Ursinus Weekly, November 11, 1971

Founder\u27s Day celebrated; Twelve students graduate • Ursinus College announces Century II Program for Academic Advancement • Government concern over pollution even greater now • Ursinus to present Kenneth E. Boulding • Editorial: Response • Focus: Carol Wasserman • Critic\u27s choice: Partridges, Linda, and physics • Faculty portrait: Dr. George Fago • Letters to the editor • Ursinus eleven wins third • Win number sixhttps://digitalcommons.ursinus.edu/weekly/1112/thumbnail.jp

The Ursinus Weekly, October 28, 1971

Opera stage director to speak at Ursinus • Homecoming Day presents something for everyone • U.C. ProTheatre presents Ionesco\u27s The Lesson • Sorority pledging in full swing • Y Coffeehouse features Doo daa in basement • Editorial: Talking to teachers; On required forums • Focus: Sue Jensen • Letters to the editor • Spotlight: Chaplain M. Detterline • Critic\u27s choice: Movie, TV, and Halloween • Object d\u27art appears; Graces Library steps • Miss Snell throws a change-up • U.C. Bears triumph; Take two in row • Bears receive honorable mention in ECAC • Soccer team drops two; Bears have rough weekhttps://digitalcommons.ursinus.edu/weekly/1110/thumbnail.jp

E valuating Support for Features in Advance d Modu larization Technologies

Abstract. A software product-line is a family of related programs. Each program is defined by a unique combination of features, where a feature is an increment in program functionality. Modularizing features is difficult, as feature-specific code often cuts across class boundaries. New modularization technologies have been proposed in recent years, but their support for feature modules has not been thoroughly examined. In this paper, we propose a variant of the expression problem as a canonical problem in product-line design. The problem reveals a set of technology-independent properties that feature modules should exhibit. We use these properties to evaluate five technologies: AspectJ, Hyper/J, Jiazzi, Scala, and AHEAD. The results suggest an abstract model of feature composition that is technology-independent and that relates compositional reasoning with algebraic reasoning 1

Campus Vol VIII N 1

Howard Studio. Chris Doner . Picture. 0. Hawk, Pete and Don Shackelford. Prose. 2. Lefevre, Ioe. A Matter Of Propriety. Prose. 3. Porter, Bob. And, In Just 7 Days-You Too Can Be a Freshman! . Picture. 4. Martin, Lyn. And, In Just 7 Days-You Too Can Be a Freshman! . Prose. 4. Clapp, joy. Resignation . Prose. 6. Hawk, Pete. Mile Faces Life: A Case History . Prose. 8. Cook, Mike. A Definition of modernity . Poem. 9.; Miller, Ted. Untitled. Poem.9. Moore, Jules. On Picnics . Poem. 9. Emmet, June. Untitled. Poem. 9. Jacobs, Edward R. Orson Got Angry Again . Prose. 10. Ski-U-Mah. Contemporary Humor . Prose. 13. Pine Needle. Untitled. Prose. 13.; Anonymous. Untitled. Prose. 13