49,788 research outputs found
Impact of dynamical chiral symmetry breaking on meson structure and interactions
We provide a glimpse of recent progress in meson physics made via QCD's
Dyson-Schwinger equations with: a perspective on confinement and dynamical
chiral symmetry breaking (DCSB); a pre'cis on the physics of in-hadron
condensates; results for the masses of the \pi, \sigma, \rho, a_1 mesons and
their first-radial excitations; and an illustration of the impact of DCSB on
the pion form factor.Comment: 6 pages, 3 figures, 1 table. Contribution to Proceedings of the 11th
International Workshop on Meson Production, Properties and Interaction,
Uniwersytet Jagiellonski, Instytut Fizyki, Krakow, Poland, 10-15 June 201
Nucleation of Spontaneous Vortices in Trapped Fermi Gases Undergoing a BCS-BEC Crossover
We study the spontaneous formation of vortices during the superfluid
condensation in a trapped fermionic gas subjected to a rapid thermal quench via
evaporative cooling. Our work is based on the numerical solution of the time
dependent crossover Ginzburg-Landau equation coupled to the heat diffusion
equation. We quantify the evolution of condensate density and vortex length as
a function of a crossover phase parameter from BCS to BEC. The more interesting
phenomena occur somewhat nearer to the BEC regime and should be experimentally
observable; during the propagation of the cold front, the increase in
condensate density leads to the formation of supercurrents towards the center
of the condensate as well as possible condensate volume oscillations.Comment: 5 pages, 3 figure
Prevalence of working smoke alarms in local authority inner city housing: randomised controlled trial
Objectives To identify which type of smoke alarm is most likely to remain working in local authority inner city housing, and to identify an alarm tolerated in households with smokers. Design Randomised controlled trial. Setting Two local authority housing estates in inner London. Participants 2145 households. Intervention Installation of one of five types of smoke alarm (ionisation sensor with a zinc battery; ionisation sensor with a zinc battery and pause button; ionisation sensor with a lithium battery and pause button; optical sensor with a lithium battery; or optical sensor with a zinc battery). Main outcome measure Percentage of homes with any working alarm and percentage in which the alarm installed for this study was working after 15 months. Results 54.4% (1166/2145) of all households and 45.9% (465/1012) of households occupied by smokers had a working smoke alarm. Ionisation sensor, lithium battery, and there being a smoker in the household were independently associated with whether an alarm was working (adjusted odds ratios 2.24 (95% confidence interval 1.75 to 2.87), 2.20 (1.77 to 2.75), and 0.62 (0.52 to 0.74)). The most common reasons for non-function were missing battery (19%), missing alarm (17%), and battery disconnected (4%). Conclusions Nearly half of the alarms installed were not working when tested 15 months later. Type of alarm and power source are important determinants of whether a household had a working alarm
Ride quality sensitivity to SAS control law and to handling quality variations
The RQ trends which large flexible aircraft exhibit under various parameterizations of control laws and handling qualities are discussed. A summary of the assumptions and solution technique, a control law parameterization review, a discussion of ride sensitivity to handling qualities, and the RQ effects generated by implementing relaxed static stability configurations are included
Dental caries experience in the Australian adult population
The definitive version is available at www.blackwell-synergy.com The document attached has been archived with permission from the Australian Dental Association (18th Jan 2007). An external link to the publisher’s copy is included
Space Station Freedom environmental control and life support system phase 3 simplified integrated test detailed report
A description of the phase 3 simplified integrated test (SIT) conducted at the Marshall Space Flight Center (MSFC) Core Module Integration Facility (CMIF) in 1989 is presented. This was the first test in the phase 3 series integrated environmental control and life support systems (ECLSS) tests. The basic goal of the SIT was to achieve full integration of the baseline air revitalization (AR) subsystems for Space Station Freedom. Included is a description of the SIT configuration, a performance analysis of each subsystem, results from air and water sampling, and a discussion of lessons learned from the test. Also included is a full description of the preprototype ECLSS hardware used in the test
Theoretical flow regime diagrams for the AGCE
The major criterion for the design of the Atmospheric General Circulation Experiment is that it be possible to realize strong baroclinic instability in the apparatus. A spherical annulus configuration which allows only steady basic state flows was chosen for the first set of stability analyses. Baroclinic instability was found for this configuration and few results suggest a regime diagram very different from the cylindrical annulus regime diagram
Effects of control laws and relaxed static stability on vertical ride quality of flexible aircraft
State variable techniques are utilized to generate the RMS vertical load factors for the B-52H and B-1 bombers at low level, mission critical, cruise conditions. A ride quality index is proposed to provide meaningful comparisons between different controls or conditions. Ride quality is shown to be relatively invariant under various popular control laws. Handling quality variations are shown to be major contributors to ride quality variations on both vehicles. Relaxed static stability is artificially implemented on the study vehicles to investigate its effects on ride quality. The B-52H ride quality is generally degraded when handling characteristics are automatically restored by a feedback control to the original values from relaxed stability conditions. The B-1 airplane shows little ride quality sensitivity to the same analysis due to the small rigid body contribution to load factors at the flight condition investigated
FACTORS INFLUENCING WEST TENNESSEE FARMERS' WILLINGNESS TO PAY FOR A BOLL WEEVIL ERADICATION PROGRAM
Data from a survey were used to evaluate Tennessee farmers' willingness to pay for the boll weevil eradication program. Producer experience, boll weevil control costs, and attitudes about boll weevil damage and insecticide usage after the program were significant explanatory variables and had a positive influence on willingness to pay.Contingent valuation, cotton, regional pest control, pest management groups, Demand and Price Analysis, Resource /Energy Economics and Policy,
- …