2,673 research outputs found
A Search for Scalar Chameleons with ADMX
Scalar fields with a "chameleon" property, in which the effective particle
mass is a function of its local environment, are common to many theories beyond
the standard model and could be responsible for dark energy. If these fields
couple weakly to the photon, they could be detectable through the "afterglow"
effect of photon-chameleon-photon transitions. The ADMX experiment was used in
the first chameleon search with a microwave cavity to set a new limit on scalar
chameleon-photon coupling excluding values between 2*10^9 and 5*10^14 for
effective chameleon masses between 1.9510 and 1.9525 micro-eV.Comment: 4 pages, 3 figure
A SQUID-based microwave cavity search for dark-matter axions
Axions in the micro eV mass range are a plausible cold dark matter candidate
and may be detected by their conversion into microwave photons in a resonant
cavity immersed in a static magnetic field. The first result from such an axion
search using a superconducting first-stage amplifier (SQUID) is reported. The
SQUID amplifier, replacing a conventional GaAs field-effect transistor
amplifier, successfully reached axion-photon coupling sensitivity in the band
set by present axion models and sets the stage for a definitive axion search
utilizing near quantum-limited SQUID amplifiers.Comment: 4 pages, 5 figures, submitted to PR
Clinical and radiological outcomes of novel digital workflow and dynamic navigation for single-implant immediate loading in aesthetic zone: 1-year prospective case series
Objectives To evaluate clinical, radiological performance of novel digital workflow integrating dynamic navigation to streamline in one-visit single-implant immediate loading in aesthetic zone. Material and methods Consecutive patients requiring one single-implant in aesthetic zone of both jaws were treated between May and September 2017. Primary outcomes were implant and prosthetic success rates, surgical and prosthetic complications, marginal bone loss (MBL), final pink aesthetic score (PES-f), and implant stability quotient (ISQ-f). Secondary outcomes were ISQ-0 and PES-0 at implant positioning and PES-p at definitive prosthesis placement. Potential effect of jaw (maxilla vs mandible), biotype (thin vs thick), type of incision (flap vs flapless), and implant site (healed vs. post-extractive) on the primary outcomes (MBL, PES-f, and ISQ-f) was evaluated through a multivariable analysis. Results Fifty-two implants were placed (follow-up 18.6, 15-20 months). One post-extractive implant failed. No other surgical, biological complications occurred, accounting for 98.10% cumulative success rate (CSR). No definitive prostheses failed. Mean MBL was -0.63 +/- 0.25 mm (-1.69 to -0.06). PES-f was 12.34 +/- 1.41 (9-14). ISQ-f was 78.1 +/- 3.2 (70-84). Age had significantly negative effect on MBL and PES-f (p = .0058 and p = .0052). No other variables significantly affected primary outcomes. Conclusions Within study limitations, investigated digital workflow integrating dynamic navigation was reliable for single-implant immediate loading in aesthetic zone in one visit. No statistically significant difference was found for MBL, PES-f, and ISQ-f, considering type of incision (flap vs. flapless), implant site (healed vs post-extractive), jaw (maxilla vs. mandible), and biotype (thick vs. thin). Live-tracked dynamic navigation may have contributed to improve operator clinical performance regardless of implant site characteristics. Further investigations are needed to confirm positive outcomes
P-T-t evolution of the Himalayan metamorphic core in the Mugu Karnali transect (Central Himalaya): preliminary data based on calculations of pseudosections
Abstract HKT-ISTP 2013
A
Axions and the Strong CP Problem
Current upper bounds of the neutron electric dipole moment constrain the
physically observable quantum chromodynamic (QCD) vacuum angle . Since QCD explains vast experimental data from the 100 MeV
scale to the TeV scale, it is better to explain this smallness of
in the QCD framework, which is the strong \Ca\Pa problem. Now,
there exist two plausible solutions to this problem, one of which leads to the
existence of the very light axion. The axion decay constant window, $10^9\
{\gev}\lesssim F_a\lesssim 10^{12} \gev{\cal O}(1)\theta_1F_a\gtrsim 10^{12}\theta_1<{\cal O}(1)$,
axions may constitute a significant fraction of dark matter of the universe.
The supersymmetrized axion solution of the strong \Ca\Pa problem introduces its
superpartner the axino which might have affected the universe evolution
significantly. Here, we review the very light axion (theory,
supersymmetrization, and models) with the most recent particle, astrophysical
and cosmological data, and present prospects for its discovery.Comment: 47 pages with 32 figure
Coalition Resilient Outcomes in Max k-Cut Games
We investigate strong Nash equilibria in the \emph{max -cut game}, where
we are given an undirected edge-weighted graph together with a set of colors. Nodes represent players and edges capture their mutual
interests. The strategy set of each player consists of the colors. When
players select a color they induce a -coloring or simply a coloring. Given a
coloring, the \emph{utility} (or \emph{payoff}) of a player is the sum of
the weights of the edges incident to , such that the color chosen
by is different from the one chosen by . Such games form some of the
basic payoff structures in game theory, model lots of real-world scenarios with
selfish agents and extend or are related to several fundamental classes of
games.
Very little is known about the existence of strong equilibria in max -cut
games. In this paper we make some steps forward in the comprehension of it. We
first show that improving deviations performed by minimal coalitions can cycle,
and thus answering negatively the open problem proposed in
\cite{DBLP:conf/tamc/GourvesM10}. Next, we turn our attention to unweighted
graphs. We first show that any optimal coloring is a 5-SE in this case. Then,
we introduce -local strong equilibria, namely colorings that are resilient
to deviations by coalitions such that the maximum distance between every pair
of nodes in the coalition is at most . We prove that -local strong
equilibria always exist. Finally, we show the existence of strong Nash
equilibria in several interesting specific scenarios.Comment: A preliminary version of this paper will appear in the proceedings of
the 45th International Conference on Current Trends in Theory and Practice of
Computer Science (SOFSEM'19
Move of a large but delicate apparatus on a trailer with air-ride suspension
When valuable delicate goods are shipped by truck, attention must be paid to
vibrations that may cause damage. We present a case study of moving an
extremely delicate 6230-kg superconducting magnet, immersed in liquid nitrogen,
from Livermore, CA to Seattle, WA showing the steps of fatigue analysis of the
load, a test move, and acceleration monitoring of the final move to ensure a
successful damage-free transport
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