882 research outputs found
Induced Innovation in Non-Hydro Renewable Technologies: The Effects of Energy Prices and Federal Spending
Our societyâs reliance on fossil fuels has many negative results, including compromised national security and foreign relations as well as environmental damage. Many see technology as the key to an improved energy future, and in particular the development of new, cleaner renewable energy sources. The question then remains how to stimulate such technological innovation. In this study, I use U.S. patent data from 1970 to 2001, along with historic energy prices and federal spending data to see the affect energy price and R&D spending have on innovation in the non-hydro renewable energy industries â solar, wind, geothermal, oceanic, and fuel cell. Using a simple regression, I found a very strong, positive relationship between both R&D spending and energy price on innovation in the non-hydro renewable energy industries. This suggests that a policy intended to stimulate renewable energy innovation could do so either through increased federal R&D spending, or by increasing energy prices through taxation or other means
Why is the Matrix Model Correct?
We consider the compactification of M theory on a light-like circle as a
limit of a compactification on a small spatial circle boosted by a large
amount. Assuming that the compactification on a small spatial circle is weakly
coupled type IIA theory, we derive Susskind's conjecture that M theory
compactified on a light-like circle is given by the finite version of the
Matrix model of Banks, Fischler, Shenker and Susskind. This point of view
provides a uniform derivation of the Matrix model for M theory compactified on
a transverse torus for and clarifies the difficulties for
larger values of .Comment: 9 page
Investigation of accessibility of electronic music resources for the visually impaired
The number of students at Western Michigan University (WMU) who require accommodation for disabilities has been increasing in recent years, and is expected to continue to increase in the future. While the University Libraries tries to be responsive to all types of accommodations, students with visual impairments present a particular challenge for libraries to ensure their electronic resources are accessible. Most visually impaired students utilize âscreen readers,â software programs that use a speech synthesizer to âreadâ the text that is displayed on the screen, to navigate web based resources. In an effort to try to better understand how specific screen readers work with our library electronic resources we employed a visually impaired student who is a sophisticated user of screen readers to test our electronic resources.Using a combination of browsers and operating systems, we used Job Access With Speech (JAWS), the most widely used screen reader, and NonVisual Desktop Access (NVDA), an open source screen reader, to test our website, our discovery layer and selected music databases. Databases tested include Music Periodicals Database (ProQuest), RILM Abstracts of Music Literature (EBSCO), and Grove Music Online. As WMU Libraries uses the ExLibris Primo discovery product, our instance of Primo was also tested for accessibility. The presenters will share the findings of the screen reader testing, including a pre-recorded demonstration of a visually impaired student conducting searches with screen readers, and describe our experiences in investigating accessibility of our electronic resources for visually impaired students. Presenters will also make recommendations for improving electronic resources and library services, in general, to better meet the needs of visually impaired patrons
A note on M(atrix) theory in seven dimensions with eight supercharges
We consider M(atrix) theory compactifications to seven dimensions with eight
unbroken supersymmetries. We conjecture that both M(atrix) theory on K3 and
Heterotic M(atrix) theory on T^3 are described by the same 5+1 dimensional
theory with N=2 supersymmetry which is broken to N=1 by the base space. The
emergence of the extra dimension follows from a recent result of
Rozali[hep-th/9702136]. We show that the seven dimensional duality between
M-theory on K3 and Heterotic string theory on T^3 is realised in M(atrix)
theory as the exchange of one of the dimensions with this new dimension.Comment: RevTeX, 8 pages, version to appear in journa
On the Matrix Description of Calabi-Yau Compactifications
We point out that the matrix description of M-theory compactified on
Calabi-Yau threefolds is in many respects simpler than the matrix description
of a compactification. This is largely because of the differences between
D6 branes wrapped on Calabi-Yau threefolds and D6 branes wrapped on six-tori.
In particular, if we define the matrix theory following the prescription of Sen
and Seiberg, we find that the remaining degrees of freedom are decoupled from
gravity.Comment: 12 pages, harvmac big; comment on 4d N=1 theories change
Total Lean Body Mass and Lower Body Lean Mass Correlation with Vertical Jump in Untrained Women Basketball Players after 8 Weeks of Resistance Training
Basketball is a fast, explosive sport where a high vertical jump (VJ) is extremely beneficial. Research has shown that greater amounts of lean mass have been associated with higher force output, and therefore higher VJ. PURPOSE: The purpose of this study is to examine the correlation of overall total lean body mass percentage (TBLM%) and lower body lean mass percentage (LBLM%) and Body fat percentage (BF%) with VJ in previously untrained collegiate D-III women basketball players. METHODS: Fourteen females (20±1.3 years, 170.68±8.76 cm, T1 BF% 28.68±5.38, T2 27.11±5.12) basketball team participated in this study. Athletes were tested on two different occasions (T1 and T2). Dual-X-Ray Absorptiometry (DXA) body composition scan and standard VJ assessment was performed using a Vertec to determine maximum jump height prior to (T1) and following (T2) 8 weeks of an undulating periodization resistance training program 5 days/week). DXA were further analyzed to determine total body lean mass % (TBLM%) and lower-body lean mass % (LBLM%). Data was analyzed using SPSS using paired samples T-test to detect differences (
On The spectrum of a Noncommutative Formulation of the D=11 Supermembrane with Winding
A regularized model of the double compactified D=11 supermembrane with
nontrivial winding in terms of SU(N) valued maps is obtained. The condition of
nontrivial winding is described in terms of a nontrivial line bundle introduced
in the formulation of the compactified supermembrane. The multivalued
geometrical objects of the model related to the nontrivial wrapping are
described in terms of a SU(N) geometrical object which in the
limit, converges to the symplectic connection related to the area preserving
diffeomorphisms of the recently obtained non-commutative description of the
compactified D=11 supermembrane.(I. Martin, J.Ovalle, A. Restuccia. 2000,2001)
The SU(N) regularized canonical lagrangian is explicitly obtained. In the limit it converges to the lagrangian in (I.Martin, J.Ovalle,
A.Restuccia. 2000,2001) subject to the nontrivial winding condition. The
spectrum of the hamiltonian of the double compactified D=11 supermembrane is
discussed.
Generically, it contains local string like spikes with zero energy.
However the sector of the theory corresponding to a principle bundle
characterized by the winding number , described by the SU(N) model we
propose, is shown to have no local string-like spikes and hence the spectrum of
this sector should be discrete.Comment: 16 pages.Latex2
Orientifolds of Matrix theory and Noncommutative Geometry
We study explicit solutions for orientifolds of Matrix theory compactified on
noncommutative torus. As quotients of torus, cylinder, Klein bottle and
M\"obius strip are applicable as orientifolds. We calculate the solutions using
Connes, Douglas and Schwarz's projective module solution, and investigate
twisted gauge bundle on quotient spaces as well. They are Yang-Mills theory on
noncommutative torus with proper boundary conditions which define the geometry
of the dual space.Comment: 17 pages, LaTeX, minor corrections, two references added, discussions
slightly expanded, to appear in Phys. Rev.
Partially-erupting prominences: a comparison between observations and model-predicted observables
<p><b>Aims:</b> We investigate several partially-erupting prominences to study their relationship with other CME-associated phenomena and compare these observations with observables predicted by a model of partially-expelled-flux-ropes (Gibson & Fan 2006a, ApJ, 637, L65; 2006b, J. Geophys. Res., 111, 12103).</p>
<p><b>Methods:</b> We studied 6 selected events with partially-erupting prominences using multi-wavelength observations recorded by the Extreme-ultraviolet Imaging Telescope (EIT), Transition Region and Coronal Explorer (TRACE), Mauna Loa Solar Observatory (MLSO), Big Bear Solar Observatory (BBSO), and Soft X-ray Telescope (SXT). The observational features associated with partially-erupting prominences were then compared with the predicted observables from the model.</p>
<p><b>Results:</b> The partially-expelled-flux-rope (PEFR) model can explain the partial eruption of these prominences, and in addition predicts a variety of other CME-related observables that provide evidence of internal reconnection during eruption. We find that all of the partially-erupting prominences studied in this paper exhibit indirect evidence of internal reconnection. Moreover, all cases showed evidence of at least one observable unique to the PEFR model, e.g., dimmings external to the source region and/or a soft X-ray cusp overlying a reformed sigmoid.</p>
<p><b>Conclusions:</b> The PEFR model provides a plausible mechanism to explain the observed evolution of partially-erupting-prominence-associated CMEs in our study.</p>
Zero-Branes, Quantum Mechanics and the Cosmological Constant
We analyse some dynamical issues in a modified type IIA supergravity,
recently proposed as an extension of M-theory that admits de Sitter space. In
particular we find that this theory has multiple zero-brane solutions. This
suggests a microscopic quantum mechanical matrix description which yields a
massive deformation of the usual M(atrix) formulation of M-theory and type IIA
string theory.Comment: 15 pages LaTeX, added reference
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