2,382 research outputs found
On intersection of domain walls in a supersymmetric model
We consider a classical field configuration, corresponding to intersection of
two domain walls in a supersymmetric model, where the field profile for two
parallel walls at a finite separation is known explicitly. An approximation to
the solution for intersecting walls is constructed for a small angle at the
intersection. We find a finite effective length of the intersection region and
also an energy, associated with the intersection.Comment: 12 pages, LaTeX, 4 figures, ep
Formation of three-particle clusters in hetero-junctions and MOSFET structures
A novel interaction mechanism in MOSFET structures and
hetero-junctions between the zone electrons of the two-dimensional (2D) gas and
the charged traps on the insulator side is considered. By applying a canonical
transformation, off-diagonal terms in the Hamiltonian due to the trapped level
subsystem are excluded. This yields an effective three-particle attractive
interaction as well as a pairing interaction inside the 2D electronic band. A
type of Bethe- Goldstone equation for three particles is studied to clarify the
character of the binding and the energy of the three-particle bound states. The
results are used to offer a possible explanation of the Metal-Insulator
transition recently observed in MOSFET and hetero-junctions.Comment: 4 page
Chemical changes in skin mucin as an index of early stages of spoilage in fish
Results of a preliminary investigation on the overall chemical nature of fish skin mucin in lung fish, Clarias batrachus, with special reference to water soluble low molecular weight compounds, are presented. Changes observed during room temperature spoilage have been studied with a view to present a new approach towards the assessment of freshness in fish inspection. pH of the mucin was distinctly alkaline (8.2) and remained unchanged during spoilage. Much of the nitrogen was found to be present in the glycoprotein fraction. Free amino acids and purine bases were present in appreciable quantities in the aqueous extracts which registered a significant increase after 10 hrs. Post-mortem increase in total solids was accompanied by a slight rise in protein nitrogen which may indicate tissue breakdown. Increase in TVN was also observed to occur earlier in the outside mucin as compared to the
inside muscle. Presence of free sugars or sialic acid could not be confirmed nor was there any indication of cholesterol and lipoid material as stated in earlier literature
Mind your meat: Religious differences in the social perception of animals
While previous work demonstrated that animals are categorised based on their edibility, little research has systematically evaluated the role of religion in the perception of animal edibility, particularly when specific animals are deemed sacred in a religion. In two studies, we explored a key psychological mechanism through which sacred animals are deemed inedible by members of a faith: mind attribution. In Study 1, non-vegetarian Hindus in Singapore (N = 70) evaluated 19 animals that differed in terms of their sacredness and edibility. Results showed that participants categorised animals into three groups: holy animals (high sacredness but low edibility), food animals (low sacredness but high edibility) and neutral animals (low sacredness and low edibility). Holy animals were deemed to possess greater mental life compared to other animal categories. In Study 2, we replicated this key finding with Hindus in India (N = 100), and further demonstrated that the observed pattern of results was specific to Hindus but not Muslims (N = 90). In both studies, mind attribution mediated the negative association between sacredness and edibility. Our findings illustrate how religious groups diverge in animal perception, thereby highlighting the role of mind attribution as a crucial link between sacredness and edibility
Ground state properties of the 2D disordered Hubbard model
We study the ground state of the two-dimensional (2D) disordered Hubbard
model by means of the projector quantum Monte Carlo (PQMC) method. This
approach allows us to investigate the ground state properties of this model for
lattice sizes up to , at quarter filling, for a broad range of
interaction and disorder strengths. Our results show that the ground state of
this system of spin-1/2 fermions remains localised in the presence of the
short-ranged Hubbard interaction.Comment: 7 pages, 9 figure
In-medium kaon and antikaon properties in the quark-meson coupling model
The properties of the kaon, , and antikaon, \kbar, in nuclear medium are
studied in the quark-meson coupling (QMC) model. Employing a constituent
quark-antiquark (MIT bag model) picture, their excitation energies in a nuclear
medium at zero momentum are calculated within mean field approximation. The
scalar, and the vector mesons are assumed to couple directly to the nonstrange
quarks and antiquarks in the and \kbar mesons. It is demonstrated that
the meson induces different mean field potentials for each member of the
isodoublets, and \kbar, when they are embedded in asymmetric nuclear
matter. Furthermore, it is also shown that this meson potential is
repulsive for the meson in matter with a neutron excess, and renders
condensation less likely to occur.Comment: Latex, 11 pages, 4 Postscript figures, a few typos which can be
important for an interpretation (but not reflected in the results) are
corrected, as published in (E) Phys. Lett. B 436 (1998) 45
The electronic transport properties and microstructure of carbon nanofiber/epoxy composites
Carbon nanofibres (CNF) were dispersed into an epoxy resin using a
combination of ultrasonication and mechanical mixing. The electronic transport
properties of the resulting composites were investigated by means of impedance
spectroscopy. It was found that a very low critical weight fraction (pc = 0.064
wt %) which may be taken to correspond to the formation of a tunneling
conductive network inside the matrix. The insulator-to-conductor transition
region spanned about one order of magnitude from 0.1 to 1 wt %. Far from the
transition, the conductivity increased by two orders of magnitude. This
increase and the low value of the conductivity were explained in terms of the
presence of an epoxy film at the contact between CNF. A simple model based on
the CNF-CNF contact network inside the matrix was proposed in order to evaluate
the thickness of that film.Comment: 7 page
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Poverty in the Midst of Plenty: Unmet Needs and Distribution of Health Care Resources in South Korea
Background: The unmet needs for health care have been used as an alternative measurement to monitor equity in health services. We sought to examine contextual influences on unmet needs for health care whereas precedent studies have been focused on individual characteristics on them. Methods and Findings: The current study conducted multilevel logistic regression analysis to assess the effects of individual- and contextual-level predictors in meeting individual health care needs in South Korea. We sampled 7,200 individuals over the age of 19 in the Fourth Korea National Health and Nutrition Examination Survey in 2009. Included in the regression model were individual predictors such as demographic variables, socio-economic status, and self-rated health; the density of beds and physicians in public and private sectors within different regions were used as contextual-level predictors. This study showed the inverse association between unmet needs and regional resources in private sectors after controlling for the effects of individual-level predictors. Conclusion: Our findings suggest that increasing regional resources in private sectors might produce inefficiency in the health care system and inequity in access to health services, particularly where the competition in private health care sectors was highly stimulated under the fee-for-service reimbursement scheme. Policies for the reallocation of health care resources and for reduction of individual health care costs are needed in Korea
A complete solution of a Constrained System: SUSY Monopole Quantum Mechanics
We solve the quantum mechanical problem of a charged particle on S^2 in the
background of a magnetic monopole for both bosonic and supersymmetric cases by
constructing Hilbert space and realizing the fundamental operators obeying
complicated Dirac bracket relations in terms of differential operators. We find
the complete energy eigenfunctions. Using the lowest energy eigenstates we
count the number of degeneracies and examine the supersymmetric structure of
the ground states in detail.Comment: 20 pages including the title, prepared in JHEP forma
An ARPES view on the high-Tc problem: phonons vs spin-fluctuations
We review the search for a mediator of high-Tc superconductivity focusing on
ARPES experiment. In case of HTSC cuprates, we summarize and discuss a
consistent view of electronic interactions that provides natural explanation of
both the origin of the pseudogap state and the mechanism for high temperature
superconductivity. Within this scenario, the spin-fluctuations play a decisive
role in formation of the fermionic excitation spectrum in the normal state and
are sufficient to explain the high transition temperatures to the
superconducting state while the pseudogap phenomenon is a consequence of a
Peierls-type intrinsic instability of electronic system to formation of an
incommensurate density wave. On the other hand, a similar analysis being
applied to the iron pnictides reveals especially strong electron-phonon
coupling that suggests important role of phonons for high-Tc superconductivity
in pnictides.Comment: A summary of the ARPES part of the Research Unit FOR538,
http://for538.wmi.badw.d
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