102,007 research outputs found
Spray coating apparatus having a rotatable workpiece holder
A spray coating apparatus is provided for rotating a workpiece relative to a spray station to obtain a uniform coating of the workpiece. In a typical example, the workpiece comprises a ceramic tile which is to be coated with a ceramic coating and the tile is to be used as a reusable component of the thermal protection system for a space shuttle. The apparatus for rotating the workpiece includes a base support having a first rotatable stage for rotation in the horizontal plane and a second rotatable stage for rotation in a second plane inclined at an angle, such as 45 degrees, to the horizontal plane and the workpiece is supported on this second stage. Thus the workpiece is rotatable in both of two planes of rotation
Two-loop corrections to Higgs boson production
In this paper we present the complete two-loop vertex corrections to scalar
and pseudo-scalar Higgs boson production for general colour factors for the
gauge group in the limit where the top quark mass gets infinite.
We derive a general formula for the vertex correction which holds for conserved
and non conserved operators. For the conserved operator we take the
electromagnetic vertex correction as an example whereas for the non conserved
operators we take the two vertex corrections above. Our observations for the
structure of the pole terms , and
in two loop order are the same as made earlier in the literature for
electromagnetism. However we also elucidate the origin of the second order
single pole term which is equal to the second order singular part of the
anomalous dimension plus a universal function which is the same for the quark
and the gluon. [3mm]Comment: 27 pages LaTeX.We correct some misprints. Moreover we have discovered
that the second order single pole term is equal to the singular part of the
second order anomalous dimension plus a universal function which is the same
for the quark and the gluon. This holds for vertex corrections as well as for
scattering amplitude
Dirac Point Degenerate with Massive Bands at a Topological Quantum Critical Point
The quasi-linear bands in the topologically trivial skutterudite insulator
CoSb are studied under adiabatic, symmetry-conserving displacement of the
Sb sublattice. In this cubic, time-reversal and inversion symmetric system, a
transition from trivial insulator to topological point Fermi surface system
occurs through a critical point in which massless (Dirac) bands are {\it
degenerate} with massive bands. Spin-orbit coupling does not alter the
character of the transition. The mineral skutterudite (CoSb) is very near
the critical point in its natural state.Comment: 5 pages, 3 figure
Development of an orthotropic hole element
A finite element was developed which adequately represents the state of stress in the region around a circular hole in orthotropic material experiencing reasonably general loading. This was achieved with a complementary virtual work formulation of the stiffness and stress matrices for a square element with center circular hole. The assumed stress state provides zero shearing stress on the hole boundary, so the element is suitable for problems involving load transfer without friction. The element has been implemented in the NASTRAN computer program, and sample problem results are presented
Swine fever and African swine fever
PIGS may become infected by viruses which also cause disease in other animals (for instance foot-and-mouth disease) but there are two virus diseases worthy of special mention because they cause clinical disease in pigs only
Cooldown time for simple cryogenic pipelines
Cooldown time for simple cryogenic pipeline
Autonomous flight and remote site landing guidance research for helicopters
Automated low-altitude flight and landing in remote areas within a civilian environment are investigated, where initial cost, ongoing maintenance costs, and system productivity are important considerations. An approach has been taken which has: (1) utilized those technologies developed for military applications which are directly transferable to a civilian mission; (2) exploited and developed technology areas where new methods or concepts are required; and (3) undertaken research with the potential to lead to innovative methods or concepts required to achieve a manual and fully automatic remote area low-altitude and landing capability. The project has resulted in a definition of system operational concept that includes a sensor subsystem, a sensor fusion/feature extraction capability, and a guidance and control law concept. These subsystem concepts have been developed to sufficient depth to enable further exploration within the NASA simulation environment, and to support programs leading to the flight test
Higgs Production at NNLO
We describe the calculation of inclusive Higgs boson production at hadronic
colliders at next-to-next-to-leading order (NNLO) in perturbative quantum
chromodynamics. We have used the technique developed in reference [4]. Our
results agree with those published earlier in the literature.Comment: Talk given at PASCOS'03, TIFR, Mumbai, LaTeX, 5 page
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