620 research outputs found
Beyond endoscopy for the Rankin-Selberg L-function
We try to understand the poles of L-functions via taking a limit in a trace
formula. This technique avoids endoscopic and Kim-Shahidi methods. In
particular, we investigate the poles of the Rankin-Selberg L-function. Using
analytic number theory techniques to take this limit, we essentially get a new
proof of the analyticity of the Rankin-Selberg L-function at Along the
way we discover the convolution operation for Bessel transforms.Comment: 27 pages; accepted to Journal of Number Theor
A nonabelian trace formula
Let be an extension of number fields with simple
and nonabelian. In [G] the first named author suggested an approach to
nonsolvable base change and descent of automorphic representations of
along such an extension. Motivated by this we prove a trace
formula whose spectral side is a weighted sum over cuspidal automorphic
representations of that are isomorphic to their
-conjugates.Comment: Comments are welcom
Thermal diffusion of supersonic solitons in an anharmonic chain of atoms
We study the non-equilibrium diffusion dynamics of supersonic lattice
solitons in a classical chain of atoms with nearest-neighbor interactions
coupled to a heat bath. As a specific example we choose an interaction with
cubic anharmonicity. The coupling between the system and a thermal bath with a
given temperature is made by adding noise, delta-correlated in time and space,
and damping to the set of discrete equations of motion. Working in the
continuum limit and changing to the sound velocity frame we derive a
Korteweg-de Vries equation with noise and damping. We apply a collective
coordinate approach which yields two stochastic ODEs which are solved
approximately by a perturbation analysis. This finally yields analytical
expressions for the variances of the soliton position and velocity. We perform
Langevin dynamics simulations for the original discrete system which fully
confirm the predictions of our analytical calculations, namely noise-induced
superdiffusive behavior which scales with the temperature and depends strongly
on the initial soliton velocity. A normal diffusion behavior is observed for
very low-energy solitons where the noise-induced phonons also make a
significant contribution to the soliton diffusion.Comment: Submitted to PRE. Changes made: New simulations with a different
method of soliton detection. The results and conclusions are not different
from previous version. New appendixes containing information about the system
energy and soliton profile
PG&E WaveConnect Program Final Report
The PG&E WaveConnect project was intended to demonstrate the technical and economic viability of wave power in the open ocean adjacent to PG&E's service territory. WaveConnect was conceived as a multi-stage development process leading to long-term megawatt-scale wave power production. The first-stage tasks consisted of site selection, permitting, pilot plant design, and assessment of technology and commercial readiness. The second stage would have included development of infrastructure, undersea cabling, and deployment of wave energy conversion devices (WECs). In the third stage, the most promising WEC devices would have been deployed in larger quantities and connected to the grid. This report documents the findings of Stage One. Site Selection: After studying the wave energy potential, grid interconnection and other project infrastructure along the California coast, PG&E selected two sites: one near Eureka, called the Humboldt WaveConnect (HWC) project, and another near Vandenberg Air Force Base, called the Central Coast WaveConnect project (CCWC). Permitting: FERC issued PG&E preliminary permits for HWC in 2008 and for CCWC in 2010. PG&E chose to use FERC's Pilot Project Licensing Process, which was intended to streamline licensing to allow relatively quick and easy installation, operation, and environmental testing for pilot projects. Permitting, however, proved to be complicated, time-consuming and expensive, mainly because of the uncertain impacts of WEC devices. PG&E learned that even under the PPLP the project would still require a full analysis under CEQA, including an EIR, as well as Monitoring and Adaptive Management Programs and other requirements that had significant cost and scheduling implications. A majority of efforts were expended on permitting activities. Pilot Plant Design: PG&E prepared a conceptual design for a 5-MW pilot test facility at the Humboldt site, which consisted of an off-shore deployment area where WECs of different designs and from different device manufacturers could be tested. PG&E was to provide permitting, subsea cables, and on-shore facilities necessary to connect WaveConnect to an existing PG&E substation, while the WEC manufacturers would provide, operate and maintain their devices during the test period. Technology and Commercial Readiness: PG&E issued a Request for Information to the wave power industry to assess the technical and commercial capabilities of WEC manufacturers. Sixteen manufacturers responded, representing the four best-known and most mature designs. PG&E found that WECs are early-stage devices with evolving designs and little real-world operating experience. These characteristics made environmental impacts difficult to assess, which complicated permitting efforts. It also made a megawatt-scale demonstration project difficult to support because early stage WECs are costly and have limited track records for performance and reliability. Results: PG&E withdrew its FERC DPLA for HWC in November 2010 and surrendered its preliminary permit for CCWC in May 2011, effectively discontinuing the project for the following combination of reasons: Permitting issues were much more challenging than originally anticipated. Stage One project funding of 6 million proved insufficient to complete the necessary development and permitting work. During Stage One development, PG&E determined that permitting costs would be 2 million to 15 million to 20 million originally estimated. Even assuming that vendors provide WEC devices at no cost to the utility, which was the proposed strategy with WaveConnect, PG&E concluded that a pilot project comparable to HWC would cost approximately 47 million. If WEC devices were purchased for such a project, its total cost would be on the order of 2500/kW for mature WECs in five to 10 years, PG&E concluded that their LCOE would be in the range of 250/MWh, which is not competitive with current or near-term renewable alternatives such as wind or solar photovoltaics. Although PG&E discontinued the project and no WEC devices were deployed, WaveConnect advanced PG&E's understanding of the technological, engineering, permitting, environmental, economic, stakeholder, and related issues involved in undertaking any wave power project now or in the future. As WEC technologies mature, and regulatory and permitting agencies grow more familiar with their environmental impacts, PG&E believes that wave power will merit further evaluation, demonstration and deployment
The Ursinus Weekly, October 10, 1969
Seven join, six leave Ursinus faculty • UC and 500 colleges schedule Vietnam moratorium Wednesday; Classes not officially cancelled • William D. Reimert dies, Ursinus Board President • Dr. E. Lewis\u27 math textbook aids Ursinus blind students • Pre-Med convention • Dean Harris weds Bryn Mawr man • Editorial: A very good year • Focus: Mike Stoner in exile • Compulsory convocation: Its validity and purpose • New view of Ursinus • Dr. Rice endorses Vietnam moratorium • Kitchen cynic: Suppose U.C. had mandatory convocations • Perspectives • To eat or not to eat • Board names new members • Spotlight: Mr. Jones, cook • Centennial plans • Opinion: Suggestions for revision of the school calendar • Weaver raps • Faculty portrait: Mrs. Lucas • Woodstock vs. Ursinus • Essay on the new age • Building plans • Freshman class • Harriers extend streak to 26 • Shuman, Mangan potential greats • Flying Dutchmen edge Bears on late T.D. • Ursinus drops grid opener to Diplomats • Registration system analyzed • Lack of needed funds signals impending collapse of agency • Astronaut Scott Carpenter opens Fall Forum series • Ursinus accounting students rank first twice, and secondhttps://digitalcommons.ursinus.edu/weekly/1149/thumbnail.jp
LED Arrays as Cost Effective and Efficient Light Sources for Widefield Microscopy
New developments in fluorophores as well as in detection methods have fueled the rapid growth of optical imaging in the life sciences. Commercial widefield microscopes generally use arc lamps, excitation/emission filters and shutters for fluorescence imaging. These components can be expensive, difficult to maintain and preclude stable illumination. Here, we describe methods to construct inexpensive and easy-to-use light sources for optical microscopy using light-emitting diodes (LEDs). We also provide examples of its applicability to biological fluorescence imaging
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