1,825 research outputs found
Study of power-jet dynamics in fluid amplifiers
This study is aimed at a better understanding of the basic dynamic behaviour of fluidic amplifiers leading to better design and more accurate modelling in systems analysis
Changes in the electronic structure and properties of graphene induced by molecular charge-transfer
Interaction with electron donor and acceptor molecules such as aniline and
nitrobenzene brings about marked changes in the Raman spectrum and the
electronic structure of graphene, prepared by the exfoliation of graphitic
oxide.Comment: 13 pages, 4 figure
Chromium uptake by Fenugreek
Fenugreek (Trigonella foenum- graecum) is both herb (leaves) and a spice (seed) belonging to the family Fabaceae. Fenugreek leaves and seeds are used in the cuisine of India. Fenugreek also has medicinal value. Fenugreek seeds are known to reduce serum glucose and improve glucose tolerance and hence are prescribed to diabetic patients. In the recent past supplemental Chromium is being prescribed to diabetic patients to activate (increased- insulin binding, insulin receptor number, insulin receptor phosphorylation) insulin. Plants can uptake substantial quantities of toxic metals from contaminated soils if these soils are well ameliorated. 

It is then probable that the medicinal efficacy of Fenugreek in the case of diabetes could be enhanced if it takes up chromium from the soil. Preliminary studies are being conducted to note the chromium uptake by Fenugreek from soils which are applied with potassium dichromate
Studies on the Accumulation of Chromium in Fenugreek
Studying Cr uptake by Fenugreek, we note that the maximum concentration of Cr takes place in the shells of the pods followed by leaves, stems and seeds in that order. Interestingly, applied higher doses of Cr does not increase accumulation of Cr in the stems, rather Cr content in the stems levels off. However, the maximum dispersal/distribution of Cr taken up is in the leaves
Axigluons cannot explain the observed top quark forward-backward asymmetry
We study an SU(3)^2 axigluon model introduced by Frampton, Shu, and Wang to
explain the recent Fermilab Tevatron observation of a significant positive
enhancement in the top quark forward-backward asymmetry relative to standard
model predictions. First, we demonstrate that data on neutral B_d-meson mixing
excludes the region of model parameter space where the top asymmetry is
predicted to be the largest. Keeping the gauge couplings below the critical
value that would lead to fermion condensation imposes further limits at large
axigluon mass, while precision electroweak constraints on the model are
relatively mild. Furthermore, by considering an extension to an SU(3)^3 color
group, we demonstrate that embedding the model in an extra-dimensional
framework can only dilute the axigluon effect on the forward-backward
asymmetry. We conclude that axigluon models are unlikely to be the source of
the observed top quark asymmetry.Comment: 12 pages, 7 eps figures included. Minor changes to conform with
published versio
High-resolution thermal expansion measurements under Helium-gas pressure
We report on the realization of a capacitive dilatometer, designed for
high-resolution measurements of length changes of a material for temperatures
1.4 K 300 K and hydrostatic pressure 250 MPa. Helium
(He) is used as a pressure-transmitting medium, ensuring
hydrostatic-pressure conditions. Special emphasis has been given to guarantee,
to a good approximation, constant-pressure conditions during temperature
sweeps. The performance of the dilatometer is demonstrated by measurements of
the coefficient of thermal expansion at pressures 0.1 MPa (ambient
pressure) and 104 MPa on a single crystal of azurite,
Cu(CO)(OH), a quasi-one-dimensional spin S = 1/2 Heisenberg
antiferromagnet. The results indicate a strong effect of pressure on the
magnetic interactions in this system.Comment: 8 pages, 7 figures, published in Rev. Sci. Instrum with minor change
Scalable parallel communications
Coarse-grain parallelism in networking (that is, the use of multiple protocol processors running replicated software sending over several physical channels) can be used to provide gigabit communications for a single application. Since parallel network performance is highly dependent on real issues such as hardware properties (e.g., memory speeds and cache hit rates), operating system overhead (e.g., interrupt handling), and protocol performance (e.g., effect of timeouts), we have performed detailed simulations studies of both a bus-based multiprocessor workstation node (based on the Sun Galaxy MP multiprocessor) and a distributed-memory parallel computer node (based on the Touchstone DELTA) to evaluate the behavior of coarse-grain parallelism. Our results indicate: (1) coarse-grain parallelism can deliver multiple 100 Mbps with currently available hardware platforms and existing networking protocols (such as Transmission Control Protocol/Internet Protocol (TCP/IP) and parallel Fiber Distributed Data Interface (FDDI) rings); (2) scale-up is near linear in n, the number of protocol processors, and channels (for small n and up to a few hundred Mbps); and (3) since these results are based on existing hardware without specialized devices (except perhaps for some simple modifications of the FDDI boards), this is a low cost solution to providing multiple 100 Mbps on current machines. In addition, from both the performance analysis and the properties of these architectures, we conclude: (1) multiple processors providing identical services and the use of space division multiplexing for the physical channels can provide better reliability than monolithic approaches (it also provides graceful degradation and low-cost load balancing); (2) coarse-grain parallelism supports running several transport protocols in parallel to provide different types of service (for example, one TCP handles small messages for many users, other TCP's running in parallel provide high bandwidth service to a single application); and (3) coarse grain parallelism will be able to incorporate many future improvements from related work (e.g., reduced data movement, fast TCP, fine-grain parallelism) also with near linear speed-ups
Export performance of Indian fisheries in the context of globalisation
Internationally traded fisheries products are characterised by a high degree of
heterogenity, reflecting the wide range of species and of processing techniques.
Indian sea food industry, by and large still remains as a supplier of raw materials to
the pre processors in foreign countries and 90 per cent goes in bulk packs, which is
the prime reason for the drastic reduction in the unit value realisation (Rao and
Prakash, 1999). India 's share in the overall trade of the world is 1.5 to 2 per cent
Quantum phase transition in a Dp-Dq system
Using the top-down approach, we study intersecting Dp-Dq brane configuration
in string theory and find examples, where there can be a quantum phase
transition at zero temperature induced by the violation of the
Breitenlohner-Freedman (BF) bound at IR, which is done essentially by a
combination of charge density and magnetic fields. In particular, there exists
a Berezinskii-Kosterlitz-Thouless (BKT) type of transition for D3-D5 and D5-D5
systems. The study of the BKT type of transition is initiated by Jensen et al.
[Phys. Rev. Lett. {\bf 105}, 041601 (2010) ] for a D3-D5 system with nonzero
charge density and a magnetic field. Here, we show that one can have the BKT
transition for a D3-D5 system even in the absence of charge density but
requires multiple magnetic fields. In this case the field theory lives in 2+1
dimensions, whereas for the D5-D5 type, the transition requires the presence of
both the charge density and magnetic fields and the dual field theory lives on
a 3+1 dimensional spacetime. We also study the D3-D7 system but it does not
show the BKT type of transition.Comment: 1+37 pages; v2 Chern-Simon term for D3-D5 case presented, typos fixed
and a reference added; v3 Minor corrections, Chern-Simon term for D2-D4,
D4-D6, and D5-D7 added, also an appendix and few references added; v4 Journal
versio
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