6,236 research outputs found
Josephson Current between Triplet and Singlet Superconductors
The Josephson effect between triplet and singlet superconductors is studied.
Josephson current can flow between triplet and singlet superconductors due to
the spin-orbit coupling in the spin-triplet superconductor but it is finite
only when triplet superconductor has , where and
are the perpendicular components of orbital angular momentum and spin angular
momentum of the triplet Cooper pairs, respectively. The recently observed
temperature and orientational dependence of the critical current through a
Josephson junction between UPt and Nb is investigated by considering a
non-unitary triplet state.Comment: 4 pages, no figure
Absence of platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) in vivo increases resistance to Salmonella enterica serovar Typhimurium in mice.
PECAM-1/CD31 is known to regulate inflammatory responses and exhibit pro- and anti-inflammatory functions. This study was designed to determine the functional role of PECAM-1 in susceptibility to murine primary in vivo infection with Salmonella enterica serovar Typhimurium and in in vitro inflammatory responses of peritoneal macrophages. Lectin profiling showed that cellular PECAM-1 and recombinant human PECAM-1-Ig chimera contain high levels of mannose sugars and N-acetylglucosamine. Consistent with this carbohydrate pattern, both recombinant human and murine PECAM-1-Ig chimeras were shown to bind S. Typhimurium in a dose-dependent manner in vitro. Using oral and fecal-oral transmission models of S. Typhimurium SL1344 infection, PECAM-1-/- mice were found to be more resistant to S. Typhimurium infection than wild-type (WT) C57BL/6 mice. While fecal shedding of S. Typhimurium was comparable in wild-type and PECAM-1-/- mice, the PECAM-1-deficient mice had lower bacterial loads in systemic organs such as liver, spleen, and mesenteric lymph nodes than WT mice, suggesting that extraintestinal dissemination was reduced in the absence of PECAM-1. This reduced bacterial load correlated with reduced tumor necrosis factor (TNF), interleukin-6 (IL-6), and monocyte chemoattractant protein (MCP) levels in sera of PECAM-1-/- mice. Following in vitro stimulation of macrophages with either whole S. Typhimurium, lipopolysaccharide (LPS) (Toll-like receptor 4 [TLR4] ligand), or poly(I·C) (TLR3 ligand), production of TNF and IL-6 by PECAM-1-/- macrophages was reduced. Together, these results suggest that PECAM-1 may have multiple functions in resistance to infection with S. Typhimurium, including binding to host cells, extraintestinal spread to deeper tissues, and regulation of inflammatory cytokine production by infected macrophages
Case studies in implementing dynamic production planning and scheduling system in make-to-order high-mix-low-volume small and medium-scaled industries for production efficiency
To manage a high-mix manufacturing environment efficiently is a big challenge for the small and medium-scaled industries (SMIs) because of the nature of its dynamic and ever changing production environment. This has added extra challenges for the SMIs to adopt the right and suitable computerized system for improvement. This paper reviews the implementation of computerized planning and scheduling system to the make-to-order (MTO) high-mix-low-volume (HMLV) SMIs to overcome their daily production challenges in managing the products, processes and resources. Investigation has been conducted in two local manufacturing companies to study the effectiveness of implementing the planning and scheduling system that has brought improvement to the MTO HMLV production environment. The research was conducted in mixed mode of qualitative and quantitative methods after the software being implemented for a year. The findings show the implementation of the system that can bring improvements overall. However, there are some other challenges not related to the software have been discovered such as human factors. The issues are listed in discussion section. The outcome of this research will accrue to manufacturers through an improved understanding of the operation and performance of implementing the system. The authors recommend further research works to be carried out to determine the other key success factors for MTO HMLV SMIs to implement computerize system to improve overall production efficiency
A case study: maturity assessment of product lifecycle management (PLM) implementation in Malaysia automotive components manufacturing company
Product Lifecycle Management (PLM) adoption is very important for companies to sustain and stay competitive in market particularly to the organizations that involving from design to manufacturing. However many companies struggle with implementing PLM because PLM is rather a concept than a system, as its main purpose is to increase product collaboration for effective product innovation with integrated streamline business processes across all functional departments to achieve operational excellence. In order to improve these challenges, maturity assessment for PLM is carried out prior to the actual implementation permitted to define the effective PLM strategic roadmap in according to the current environment condition. In this paper, case study and maturity assessment for local automotive components manufacturing company was conducted. The results are discussed in the theoretical and empirical aspects. The finding showed the importance and practicality of the PLM readiness to the companies. The assessment required to be comprehensive to cover the readiness of (1) data readiness, (2) process readiness and (3) people, culture and IT infrastructure. In general, the PLM maturity assessment is a useful and beneficial tool in the implementation and development of PLM framework
Magnetic Field Effect on the Supercurrent of an SNS junction
In this paper we study the effect of a Zeeman field on the supercurrent of a
mesoscopic SNS junction. It is shown that the supercurrent suppression is due
to a redistribution of current-carrying states in energy space. A dramatic
consequence is that (part of the) the suppressed supercurrent can be recovered
with a suitable non-equilibrium distribution of quasiparticles.Comment: 4 figures in postscrip
Electronic State and Magnetic Susceptibility in Orbitally Degenerate (J=5/2) Periodic Anderson Model
Magnetic susceptibility in a heavy fermion systemis composed of the Pauli
term (\chi_P) and the Van-Vleck term (\chi_V). The latter comes from the
interband excitation, where f-orbital degeneracy is essential. In this work, we
study \chi_P and \chi_V in the orbitally degenerate (J=5/2) periodic Anderson
model for both the metallic and insulating cases. The effect of the correlation
between f-electrons is investigated using the self-consistent second-order
perturbation theory. The main results are as follows. (i) Sixfold degenerate
model: both \chi_P and \chi_V are enhanced by a factor of 1/z (z is the
renormalization constant). (ii) Nondegenerate model: only \chi_P is enhanced by
1/z. Thus, orbital degeneracy is indispensable for enhancement of \chi_V.
Moreover, orbital degeneracy reduces the Wilson ratio and stabilizes a
nonmagnetic Fermi liquid state.Comment: 4 pages, revtex, to be published in J. Phys. Soc. Jpn. (No.8
Odd Parity and Line Nodes in Heavy Fermion Superconductors
Group theory arguments have demonstrated that a general odd parity order
parameter cannot have line nodes in the presence of spin-orbit coupling. In
this paper, it is shown that these arguments do not hold on the
zone face of a hexagonal close packed lattice. In particular, three of the six
odd parity representations vanish identically on this face. This has potential
relevance to the heavy fermion superconductor .Comment: 5 pages, revte
Deformation of Quantum Dots in the Coulomb Blockade Regime
We extend the theory of Coulomb blockade oscillations to quantum dots which
are deformed by the confining potential. We show that shape deformations can
generate sequences of conductance resonances which carry the same internal
wavefunction. This fact may cause strong correlations of neighboring
conductance peaks. We demonstrate the relevance of our results for the
interpretation of recent experiments on semiconductor quantum dots.Comment: 4 pages, Revtex, 4 postscript figure
Dynamic Mean-Field Glass Model with Reversible Mode Coupling and Trivial Hamiltonian
Often the current mode coupling theory (MCT) of glass transitions is compared
with mean field theories. We explore this possible correspondence. After
showing a simple-minded derivation of MCT with some difficulties we give a
concise account of our toy model developed to gain more insight into MCT. We
then reduce this toy model by adiabatically eliminating rapidly varying
velocity-like variables to obtain a Fokker-Planck equation for the slowly
varying density-like variables where diffusion matrix can be singular. This
gives a room for nonergodic stationary solutions of the above equation.Comment: 9 pages, contribution to the Proceedings of the Merida Satellite
Meeting to STATPHYS21 (Merida, Mexico, July 9-14, 2001). To appear in J.
Phys. Condens. Matte
Absence of non-linear Meissner effect in YBa2Cu3O6.95
We present measurements the field and temperature dependence of the
penetration depth (lambda) in high purity, untwinned single crystals of
YBa2Cu3O6.95 in all three crystallographic directions. The temperature
dependence of lambda is linear down to low temperatures, showing that our
crystals are extremely clean. Both the magnitude and temperature dependence of
the field dependent correction to lambda however, are considerably different
from that predicted from the theory of the non-linear Meissner effect for a
d-wave superconductor (Yip-Sauls theory). Our results suggest that the
Yip-Sauls effect is either absent or is unobservably small in the Meissner
state of YBa2Cu3O6.95.Comment: 4 pages, 4 figures (Latex file + Postscipt figures
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