2,010 research outputs found
Ritchey-Chretien Telescope
A Ritchey-Chretien telescope is described which was designed to respond to images located off the optical axis by using two transparent flat plates positioned in the ray path of the image. The flat plates have a tilt angle relative to the ray path to compensate for astigmatism introduced by the telescope. The tilt angle of the plates is directly proportional to the off axis angle of the image. The plates have opposite inclination angles relative to the ray paths. A detector which is responsive to the optical image as transmitted through the plates is positioned approximately on the sagittal focus of the telescope
Fine guidance for a spaceborne telescope
Two transparent plates are mounted at equal and opposite angles in secondary optical-system housing, angles being set for optimum astigmatism correction. Rotation of secondary housing assembly and translation of detector are proportional to angular position of secondary image. Combined movement of two retains image within sagittal foci of secondary system
Integrating Theory and Practice Into the Professional Responsibility Curriculum at the University of Texas
Teaching ethics to large classes has always proved to be a great challenge for those who teach professional responsibility at the University of Texas. A new program at the University of Texas to improve the professional responsibility curriculum is discussed
Emergent Collectivity in Nuclei and Enhanced Proton-Neutron Interactions
Enhanced proton-neutron interactions occur in heavy nuclei along a trajectory
of approximately equal numbers of valence protons and neutrons. This is also
closely aligned with the trajectory of the saturation of quadrupole
deformation. The origin of these enhanced p-n interactions is discussed in
terms of spatial overlaps of proton and neutron wave functions that are
orbit-dependent. It is suggested for the first time that nuclear collectivity
is driven by synchronized filling of protons and neutrons with orbitals having
parallel spins, identical orbital and total angular momenta projections,
belonging to adjacent major shells and differing by one quantum of excitation
along the z-axis. These results may lead to a new approach to symmetry-based
theoretical calculations for heavy nuclei.Comment: 6 pages, 4 figure
Higgs Masses in the Minimal SUSY SO(10) GUT
We explicitly show that minimal SUSY SO(10) Higgs-Higgsino mass matrices
evaluated by various groups are mutually consistent and correct. We comment on
the corresponding results of other authors. We construct one-to-one mappings of
our approach to the approaches of other authors.Comment: 4 pages, revtex4, Changes in the paper : We agree with Ref.
hep-ph/0501025 that there there should exist equivalence mappings between
results of Higgs mass spectra calculated by three groups of authors. (in
three different approaches. However, in the Note added of the Ref.
hep-ph/0405074 v3 the wrong mapping was presented. The explicit construction
of equivalence mappings to other approches is given. Minor changes in the
text. Paper is beeing accepted for publication in Phys. Rev
Solar Gain through Windows with Shading Devices: Simulation Versus Measurement
© 2009, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions 2009, vol. 115, part 2. For personal use only. Additional reproduction, distribution, or transmission in either print
or digital form is not permitted without ASHRAE’s prior written permission.Shading devices offer a cost saving strategy in dynamically controlling solar gain through windows. As such, there is an ongoing effort to accurately quantify the thermal performance of shading devices. In the present study, solar gain through various shading devices attached to a conventional double glazed window was measured using the National Solar Test Facility (NSTF) solar simulator and solar calorimeter. The shading devices include two venetian blinds, a roller blind, a pleated drape and an insect screen. More specifically, the solar heat gain coefficient (SHGC) and the solar transmittance, tsys, of each system were measured; and the interior attenuation coefficient (IAC) was calculated from the SHGC measurements. Furthermore, SHGC, tsys and IAC were calculated for the same experimental conditions using models developed for building energy simulation and performance rating. The calculations agreed very well with the measurements.NRCan (Natural Resources Canada) || NSERC (Natural Scienes and Engineering Research Council Canada) || ASHRA
The pleiotropic deubiquitinase Ubp3 confers aneuploidy tolerance
Aneuploidy-or an unbalanced karyotype in which whole chromosomes are gained or lost-causes reduced fitness at both the cellular and organismal levels but is also a hallmark of human cancers. Aneuploidy causes a variety of cellular stresses, including genomic instability, proteotoxic and oxidative stresses, and impaired protein trafficking. The deubiquitinase Ubp3, which was identified by a genome-wide screen for gene deletions that impair the fitness of aneuploid yeast, is a key regulator of aneuploid cell homeostasis. We show that deletion of UBP3 exacerbates both karyotype-specific phenotypes and global stresses of aneuploid cells, including oxidative and proteotoxic stress. Indeed, Ubp3 is essential for proper proteasome function in euploid cells, and deletion of this deubiquitinase leads to further proteasome-mediated proteotoxicity in aneuploid yeast. Notably, the importance of UBP3 in aneuploid cells is conserved. Depletion of the human homolog of UBP3, USP10, is detrimental to the fitness of human cells upon chromosome missegregation, and this fitness defect is accompanied by autophagy inhibition. We thus used a genome-wide screen in yeast to identify a guardian of aneuploid cell fitness conserved across species. We propose that interfering with Ubp3/USP10 function could be a productive avenue in the development of novel cancer therapeutics
Anaerobic digestion of whole-crop winter wheat silage for renewable energy production
With biogas production expanding across Europe in response to renewable energy incentives, a wider variety of crops need to be considered as feedstock. Maize, the most commonly used crop at present, is not ideal in cooler, wetter regions, where higher energy yields per hectare might be achieved with other cereals. Winter wheat is a possible candidate because, under these conditions, it has a good biomass yield, can be ensiled, and can be used as a whole crop material. The results showed that, when harvested at the medium milk stage, the specific methane yield was 0.32 m3 CH4 kg–1 volatile solids added, equal to 73% of the measured calorific value. Using crop yield values for the north of England, a net energy yield of 146–155 GJ ha–1 year–1 could be achieved after taking into account both direct and indirect energy consumption in cultivation, processing through anaerobic digestion, and spreading digestate back to the land. The process showed some limitations, however: the relatively low density of the substrate made it difficult to mix the digester, and there was a buildup of soluble chemical oxygen demand, which represented a loss in methane potential and may also have led to biofoaming. The high nitrogen content of the wheat initially caused problems, but these could be overcome by acclimatization. A combination of these factors is likely to limit the loading that can be applied to the digester when using winter wheat as a substrat
Multimedia delivery in the future internet
The term “Networked Media” implies that all kinds of media including text, image, 3D graphics, audio
and video are produced, distributed, shared, managed and consumed on-line through various networks,
like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white
paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked
challenges of the Networked Media in the transition to the Future of the Internet.
Internet has evolved and changed the way we work and live. End users of the Internet have been confronted
with a bewildering range of media, services and applications and of technological innovations concerning
media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace
of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more
than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so
regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected
to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising
to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged
that in a near- to mid-term future, the Internet will provide the means to share and distribute (new)
multimedia content and services with superior quality and striking flexibility, in a trusted and personalized
way, improving citizens’ quality of life, working conditions, edutainment and safety.
In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe
network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as
community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of
interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and
innovative applications “on the move”, like virtual collaboration environments, personalised services/
media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content
combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P
networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to
contribute towards such a vision.
Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6)
and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily
contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way
ahead in the area of Content Aware media delivery platforms
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