19,788 research outputs found
Characterization of quantum well structures using a photocathode electron microscope
Present day integrated circuits pose a challenge to conventional electronic and mechanical test methods. Feature sizes in the submicron and nanometric regime require radical approaches in order to facilitate electrical contact to circuits and devices being tested. In addition, microwave operating frequencies require careful attention to distributed effects when considering the electrical signal paths within and external to the device under test. An alternative testing approach which combines the best of electrical and optical time domain testing is presented, namely photocathode electron microscope quantitative voltage contrast (PEMQVC)
Visible Cascade Higgs Decays to Four Photons at Hadron Colliders
The presence of a new singlet scalar particle a can open up new decay
channels for the Higgs boson, through cascades of the form h -> 2a -> X,
possibly making discovery through standard model channels impossible. If a is
CP-odd, its decay products are particularly sensitive to physics beyond the
standard model. Quantum effects from heavy fields can naturally make gluonic
decay, a -> 2g, the dominant decay mode, resulting in a h -> 4 g decay which is
difficult to observe at hadron colliders, and is allowed by LEP for m_h > 82
GeV. However, there are usually associated decays with photons, either h -> 2g
2gamma or h -> 4gamma, which are more promising. The decay h -> 2g 2gamma only
allows discovery of the a particle and not the Higgs whereas h -> 4gamma is a
clean channel that can discover both particles. We determine what branching
ratios are required for discovery at LHC and find that with 300 fb^-1 of
luminosity, a branching ratio of order 10^-4 is sufficient for a large region
of Higgs masses. Due to a lower expected luminosity of ~ 8 fb^-1, discovery at
the Tevatron requires more than 5 x 10^-3 in branching ratio.Comment: 6 pages, 2 color figures, revtex4 forma
Increased Adenine Nucleotide Degradation in Skeletal Muscle Atrophy
Adenine nucleotides (AdNs: ATP, ADP, AMP) are essential biological compounds that facilitate many necessary cellular processes by providing chemical energy, mediating intracellular signaling, and regulating protein metabolism and solubilization. A dramatic reduction in total AdNs is observed in atrophic skeletal muscle across numerous disease states and conditions, such as cancer, diabetes, chronic kidney disease, heart failure, COPD, sepsis, muscular dystrophy, denervation, disuse, and sarcopenia. The reduced AdNs in atrophic skeletal muscle are accompanied by increased expression/activities of AdN degrading enzymes and the accumulation of degradation products (IMP, hypoxanthine, xanthine, uric acid), suggesting that the lower AdN content is largely the result of increased nucleotide degradation. Furthermore, this characteristic decrease of AdNs suggests that increased nucleotide degradation contributes to the general pathophysiology of skeletal muscle atrophy. In view of the numerous energetic, and non-energetic, roles of AdNs in skeletal muscle, investigations into the physiological consequences of AdN degradation may provide valuable insight into the mechanisms of muscle atrophy
Data Compression System with a Minimum Time Delay Unit-Patent
Minimum time delay unit for conventional time multiplexed data compression channel
Influence of Dilute Acetic Acid Treatments on American Pondweed Winter Buds in the Nevada Irrigation District, California
American pondweed (
Potamogeton nodosus
Poir.) is commonly
found in northern California irrigation canals. The
purpose of this study was to test the hypothesis that exposure
of American pondweed winter buds to dilute acetic acid under
field conditions would result in reduced subsequent biomass
Engineering - what's that?
Engineering the Future (EtF) aims to develop a sustainable model of activities and interactions among researchers, policy makers and practitioners that develops pupils’ understanding of the nature of engineering, embeds experiences of engineering within the school classroom and curriculum and promotes engineering as a career.One barrier to young people entering engineering is inadequate awareness of the nature ofengineering and its diverse career paths. Many pupils in the participating schools had no awareness of engineering or very limited awareness. 65% had never considered engineering as a career choice.1st year electronic and electrial engineering students at the universities of Strathclyde and Glasgow identified family links as a key factor in encouraging them to study engineering. They also traced interest in engineering to particular school classroom experiences. Discussions with careers guidance staff revealed that careers guidance is almost entirely responsive to pupil requests: only occasionally will pupils who are good at science and mathematics be directed towards engineering.The current situation leaves almost all school pupils uninformed about the nature of engineering.The paper describes how the EtF project seeks to redress the situation by developing classroom engineering experiences, working to embed engineering formally in the curriculum and providing resources for active careers advice
Upon neutralizing the odour of Nomius pygmaeus (Dej.), the stink beetle (Coleoptera: Carabidae)
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