903 research outputs found
Distinguishing Color-Octet and Color-Singlet Resonances at the Large Hadron Collider
Di-jet resonance searches are simple, yet powerful and model-independent,
probes for discovering new particles at hadron colliders. Once such a resonance
has been discovered it is important to determine the mass, spin, couplings,
chiral behavior and color properties to determine the underlying theoretical
structure. We propose a new variable which, in the absence of decays of the
resonance into new non-standard states, distinguishes between color-octet and
color-singlet resonances. To keep our study widely applicable we study
phenomenological models of color-octet and color-singlet resonances in flavor
universal as well as flavor non-universal scenarios. We present our analysis
for a wide range of mass (2.5 - 6 TeV), couplings and flavor scenarios for the
LHC with center of mass energy of 14 TeV and varying integrated luminosities of
30, 100, 300 and 1000 . We find encouraging results to
distinguish color-octet and color-singlet resonances for different flavor
scenarios at the LHC.Comment: 24 pages, 5 figures, 1 tabl
In situ characterization of vertically oriented carbon nanofibers for three-dimensional nano-electro-mechanical device applications
We have performed mechanical and electrical characterization of individual as-grown, vertically oriented carbon nanofibers (CNFs) using in situ techniques, where such high-aspect-ratio, nanoscale structures are of interest for three-dimensional (3D) electronics, in particular 3D nano-electro-mechanical-systems (NEMS). Nanoindentation and uniaxial compression tests conducted in an in situ nanomechanical instrument, SEMentor, suggest that the CNFs undergo severe bending prior to fracture, which always occurs close to the bottom rather than at the substrate–tube interface, suggesting that the CNFs are well adhered to the substrate. This is also consistent with bending tests on individual tubes which indicated that bending angles as large as ~70° could be accommodated elastically. In situ electrical transport measurements revealed that the CNFs grown on refractory metallic nitride buffer layers were conducting via the sidewalls, whereas those synthesized directly on Si were electrically unsuitable for low-voltage dc NEMS applications. Electrostatic actuation was also demonstrated with a nanoprobe in close proximity to a single CNF and suggests that such structures are attractive for nonvolatile memory applications. Since the magnitude of the actuation voltage is intimately dictated by the physical characteristics of the CNFs, such as diameter and length, we also addressed the ability to tune these parameters, to some extent, by adjusting the plasma-enhanced chemical vapor deposition growth parameters with this bottom-up synthesis approach
The multifrequency behaviour of the recurrent nova RS Ophiuchi
This review concentrates on the multifrequency behaviour of RS Ophiuchi and
in particular during its latest outburst. Confirmation of the 1945 outburst,
bipolar outflows and its possible fate as a Type Ia Supernova are discussed.Comment: 5 pages, 5 figures, in The Golden Age of Cataclysmic Variables and
Related Objects, F. Giovannelli & L. Sabau-Graziati (eds.), Mem. SAIt. 83 N.2
(in press
SECURING MULTIHOP NETWORK BY DETECTING AND LOCATING POLLUTION ATTACKS USING SPACEMAC.
It has been widely observed that providing security is one of the challenging task in Wireless sensor network(WSN). Program images need to be updated continuously as network programming happens in WSN. Many Networking protocols provide an efficient way to update these program images running on sensor nodes. One of the cryptographically strong protocol called DELUGE exists to address this challenge, but it involves high computational cost such as power consumption and communication costs. So Multiple one way key chain is proposed to secure a multihop network programming protocol which is lower in power consumption and communication costs. Even though one way key chain is used to provide security, network with static topology is considered. Network is made dynamic by adding mobility nodes to it. But the extra node added may not always be the genuine node. If it is an attacker node, there can be several pollution attacks. Attacker node travels through the network, and pollute the entire network. Wirelesss sensor network may not be able to detect these pollution attacks. In this paper, we are proposing a MAC scheme called Spacemac. It expands the network by adding nodes to it. Using SpaceMac, i) it detects the polluted packets early at the intermediate nodes. ii) it identifies the exact location of an attacker and eliminates them
Novae as a Mechanism for Producing Cavities around the Progenitors of SN 2002ic and Other SNe Ia
We propose that a nova shell ejected from a recurrent nova progenitor system
created the evacuated region around the explosion center of SN 2002ic. In this
picture, periodic shell ejections due to nova explosions on a white dwarf sweep
up the slow wind from the binary companion, creating density variations and
instabilities that lead to structure in the circumstellar medium (CSM). Our
model naturally explains the observed gap between the supernova explosion
center and the CSM in SN 2002ic, accounts for the density variations observed
in the CSM, and resolves the coincidence problem of the timing of the explosion
of SN 2002ic with respect to the apparent cessation of mass-loss in the
progenitor system. We also consider such nova outburst sweeping as a generic
feature of Type Ia supernovae with recurrent nova progenitors.Comment: Accepted to ApJL. 11 pages, 1 tabl
Association between HMG CoA reductase inhibitors and anxiety:an experimental study using elevated plus maze and light dark arena behavioural models
Background: Aims: To investigate the effect of HMG CoA reductase inhibitors on behavioural models of anxiety in male swiss mice using Elevated plus maze test and light-dark arena test.Methods: It was an experimental study, carried out in department of Pharmacology, J. N. Medical College, KLE University, Belgaum. The in vivo behavioural activity of simvastatin, lovastatin, atorvastatin was studied using EPM and light-dark arena test. The mice received the drugs as per their weight and subjected for experimentation. Group mean time spent and number of entries into open arm in EPM test and group mean number of entries and time spent in the light area was calculated in treated and control groups for comparison. Statistical analysis was done using ANOVA followed by Bonferroni’s multiple comparison test (P<0.05).Results: Going through the results of this study an evidence for the association between lowered serum cholesterol and symptoms of anxiety can be seen as statins used in the present study failed to show significant anxiolytic effect when compared to standard but in turn showed even more less activity when compared to control, indicating anxiogenic behavior.Conclusions: Our findings support the evidence of the negative effects of statins on psychological outcomes.  It's generally understood that having low cholesterol is a good health sign, combined with other factors; it could actually put a person at risk by causing anxiety and stress. Further research comprising a greater number of studies is required to confirm the effects of this agent on psychological outcomes. Â
Integrated Pest and Disease Management in Tomato: An Economic Analysis
The adoption of IPM technology in tomato using African marigold as a trap crop, root dipping of seedlings in Imidacloprid, soil application of neem/pongamia cake, spraying of botanicals like pongamia soap and biopesticide like Ha NPV has been found effective in both insect as well as disease management. The IPM technology has been found economically viable as the yield on IPM farms has been found higher by about 46 per cent, cost of cultivation has been less by about 21 per cent and the net returns have been higher by 119 per cent. The technology can be considered environment-friendly as it uses more of eco-friendly inputs and less of chemicals. The constraints like non-availability of botanicals and bio-pesticides should be addressed on priority basis to make the technology sustainable and more popular.Agricultural and Food Policy,
Probing Color Octet Couplings at the Large Hadron Collider
Color-octet resonances arise in many well motivated theories beyond the
standard model. As colored objects they are produced copiously at the LHC and
can be discovered in early searches for new physics in dijet final states. Once
they are discovered it will be important to measure the couplings of the new
resonances to determine the underlying theoretical structure. We propose a new
channel, associated production of gauge bosons and color-octet
resonances, to help determine the chiral structure of the couplings. We present
our analysis for a range of color-octet masses (2.5 to 4.5 TeV), couplings and
decay widths for the LHC with center of mass energy of 14 TeV and 10 or 100 of integrated luminosity. We find that the LHC
can probe a large region of the parameter space up to very small couplings.Comment: 19 pages, 9 figures, 3 table
Biomarker and pollen approach to reconstruct Late Holocene climate and environmental history in western Sri Lnka
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