1,999 research outputs found
Orbiting valence quarks and their influence on the structure functions of the nucleon
It is shown that intrinsic orbital motion of the valence quarks has large
influences on the spin-dependent as well as the spin-averaged nucleon structure
functions. Its connection with the observed ``very small contribution of quark
spin to nucleon spin'' and the observed violation of Gottfried sum rule is
discussed.Comment: 10 pages (LaTeX) including 3 figure
On the high strain rate behavior of 63-37 Sn-Pb eutectic solders with temperature effects
This study presents experimental results performed on samples of Eutectic solder material (63 wt. % Sn 37 wt. % Pb) loaded at high strain rates and elevated temperatures. The tests were performed at high strain rates using Split Hopkinson Pressure Bar (SHPB). The strain rates were in the range of 400 s-1to 1300 s-1. Heating unit was added to conventional SHPB to vary sample' s initial temperature conditions. Tests were conducted at three initial temperatures, i.e. room temperature, 60 °C and 120 °C for compressive mode. The effects of temperature on the behavior of material were compared. Transient temperature changes during dynamic loading conditions are calculated by an analytical approach using measured stress-strain data for plastic work. Test results were fitted into the Johnson-Cook model (JC model). In addition, dynamic tests were performed in tension mode using Split Hopkinson Tensile Bar (SHTB) at room temperature
Likelihood Of Achieving Who Leprosy Goals: An Expert Survey
Much progress has been made in the global fight against leprosy, as evidenced by dramatic declines in prevalence rates in recent years. However, leprosy has proven elusive. New case detection rates have remained fairly stable, particularly in countries with remaining pockets of high endemicity such as India, Brazil, and Indonesia. In 2012, the World Health Organization spearheaded the London Declaration, which in part aimed for the goal of interruption of transmission of global leprosy by 2020. Aggregating the opinions of experts can supplement existing data to help determine the feasibility of reaching the WHO goals. To obtain the opinions of experts, a cross-sectional survey was sent requesting experts to give probabilistic estimates on the likelihood of achieving leprosy control targets. The survey results showed that most experts do not think the 2020 leprosy control targets will be met. The majority of experts indicated enhanced case finding as the most important measure to undertake to improve leprosy control goal success. The collection of expert opinions highlights the need for continued attention on leprosy from a public health standpoint
Criticality in quark-gluon systems far beyond thermal and chemical equilibrium
Experimental evidence and theoretical arguments for the existence of
self-organized criticality in systems of gluons and quarks are presented. It is
observed that the existing data for high-transverse-momentum jet-production
exhibit striking regularities; and it is shown that, together with
first-principle considerations, such regularities can be used, not only to
probe the possible compositness of quarks, but also to obtain {\em direct
evidence} for, or against, the existence of critical temperature and/or
critical chemical potential in quark-gluon systems when hadrons are squeezed
together.Comment: 13 pages, including 1 figure and 1 tabl
Formation of color-singlet gluon-clusters and inelastic diffractive scattering
This is the extensive follow-up report of a recent Letter in which the
existence of self-organized criticality (SOC) in systems of interacting soft
gluons is proposed, and its consequences for inelastic diffractive scattering
processes are discussed. It is pointed out, that color-singlet gluon-clusters
can be formed in hadrons as a consequence of SOC in systems of interacting soft
gluons, and that the properties of such spatiotemporal complexities can be
probed experimentally by examing inelastic diffractive scattering. Theoretical
arguments and experimental evidences supporting the proposed picture are
presented --- together with the result of a systematic analysis of the existing
data for inelastic diffractive scattering processes performed at different
incident energies, and/or by using different beam-particles. It is shown in
particular that the size- and the lifetime-distributions of such gluon-clusters
can be directly extracted from the data, and the obtained results exhibit
universal power-law behaviors --- in accordance with the expected
SOC-fingerprints. As further consequences of SOC in systems of interacting soft
gluons, the -dependence and the -dependence of the double
differential cross-sections for inelastic diffractive scattering off
proton-target are discussed. Here stands for the four-momentum-transfer
squared, for the missing mass, and for the total c.m.s.
energy. It is shown, that the space-time properties of the color-singlet
gluon-clusters due to SOC, discussed above, lead to simple analytical formulae
for and for , and that the obtained
results are in good agreement with the existing data. Further experiments are
suggested.Comment: 67 pages, including 11 figure
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