3,583 research outputs found
The Jang equation reduction of the spacetime positive energy theorem in dimensions less than eight
We extend the Jang equation proof of the positive energy theorem due to R.
Schoen and S.-T. Yau from dimension to dimensions . This
requires us to address several technical difficulties that are not present when
. The regularity and decay assumptions for the initial data sets to which
our argument applies are weaker than those of R. Schoen and S.-T. Yau. In
recent joint work with L.-H. Huang, D. Lee, and R. Schoen we have given a
different proof of the full positive mass theorem in dimensions .
We pointed out that this theorem can alternatively be derived from our density
argument and the positive energy theorem of the present paper.Comment: All comments welcome! Final version to appear in Comm. Math. Phy
Existence, Regularity, and Properties of Generalized Apparent Horizons
We prove a conjecture of Tom Ilmanen's and Hubert Bray's regarding the
existence of the outermost generalized apparent horizon in an initial data set
and that it is outer area minimizing.Comment: 16 pages, thoroughly revised, no major changes, to appear in Comm.
Math. Phy
Utilization requirements. A southern California Gas Company project SAGE report: Utilization requirements
Utilization requirements are given and comparisons made of two phase III SAGE (solar assisted gas energy) installations in California: (1) a retrofit installation in an existing apartment building in El Toro, and (2) an installation in a new apartment building in Upland. Such testing in the field revealed the requirements to be met if SAGE-type installations are to become commercially practical on a widespread basis in electric and gas energy usage
Good Enough for Government Work?: The Government Performance Results Act of 1993 and Its Impact on Federal Agencies
Confronting the Appalachian Breakdown: Historic Preservation Law in Appalachia and the Potential Benefits of Historic Preservation for Rural Communities
Manned geosynchronous mission requirements and systems analysis study add-on
An MOTV mission model was constructed in order to establish the baseline condition for SOC basing. A mission model to reflect satellite servicing was extended. Yearly traffic was projected. Driver missions were categorized. Cost trades and sensitivity to traffic rates were performed and service equipment needs were identified
VASCOMP 2. The V/STOL aircraft sizing and performance computer program. Volume 6: User's manual, revision 3
This report describes the use of the V/STOL Aircraft Sizing and Performance Computer Program (VASCOMP II). The program is useful in performing aircraft parametric studies in a quick and cost efficient manner. Problem formulation and data development were performed by the Boeing Vertol Company and reflects the present preliminary design technology. The computer program, written in FORTRAN IV, has a broad range of input parameters, to enable investigation of a wide variety of aircraft. User oriented features of the program include minimized input requirements, diagnostic capabilities, and various options for program flexibility
Improving Reading Fluency of Elementary Students with Learning Disabilities Through Reader\u27s Theater
Elementary teachers in a school district in a western state expressed concerns about the reading achievement of students with disabilities (SWDs). SWDs were not developing decoding, comprehension, and fluency skills to become proficient readers. Without mastering these skills, SWDs will experience diminished academic attainment in their school career. To address this problem, teachers in elementary learning centers (LCs) within the district implemented Reader\u27s Theater (RT), an evidenced-based reading approach that incorporates repeated readings using drama-based activities. The purpose of this qualitative bounded case study was to explore elementary LC teachers\u27 use and implementation of RT to improve reading performance with SWDs. Gardner\u27s theory of multiple intelligences served as the conceptual framework for this study. A purposeful sample of 2 LC teachers who implemented RT with SWDs volunteered to participate in semistructured interviews. Qualitative data were analyzed thematically using open coding. The 2 LC teachers noted that RT was useful to increase SWDs\u27 willingness to read, reading fluency, and student investment by integrating repeated reading opportunities in drama-based activities. Based on the research findings, a 3-day RT professional development workshop was developed to assist elementary LC teachers in the district to teach early reading skills to SWDs. This endeavor may contribute to positive social change by providing LC teachers with knowledge about RT that is useful in improving SWDs\u27 fluency, decoding, and comprehension skills and, ultimately, enhancing their reading achievement
Depletion potentials near geometrically structured substrates
Using the recently developed so-called White Bear version of Rosenfeld's
Fundamental Measure Theory we calculate the depletion potentials between a
hard-sphere colloidal particle in a solvent of small hard spheres and simple
models of geometrically structured substrates: a right-angled wedge or edge. In
the wedge geometry, there is a strong attraction beyond the corresponding one
near a planar wall that significantly influences the structure of colloidal
suspensions in wedges. In accordance with an experimental study, for the edge
geometry we find a free energy barrier of the order of several which
repels a big colloidal particle from the edge.Comment: 7 pages, 7 figure
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