464 research outputs found
EXTENDED MODELLING AND NUMERICAL INVESTIGATION OF PHASED ARRAY SYNTHETIC JET CROSS-FLOW INTERACTIONS
A classical analysis of incompressible unsteady Navier-Stokes equation have been under discussion for a long time by various reasearchers, it has been found that the exact analytical unique solution existed only below and undefined Reynolds number limit. Several solutions were existed for a range of Reynolds number above the limit, and that has no solution exsisted above the second undefined Reynolds number (i.e, solution enter into turbulent region and one has to solve another set of equations for turbulance). A useful study was done for two dimensional unsteady incompressible flow in which vorticity is propotional to stream function perturbed by uniform stream. Recently this unsteady sloution was used to analyse the flow behaviour on flat plate using Synthetic Jet Actuators (SJA) which consists of oscillating membrane expels in fluid through orifice. The results obtained at different time level were presented and it was found as the time progresses streamlines, on the flat plate with number of actuators placed in an array, become flatter caused rapidly decay in vortices on trailing edge. The authentication of these results were needded to be validated through experiment or numerical simulation. In this paper, an attempt has been made to solve incompressible unsteady Navier-Stokes equations numerically to analyse the behaviour of single and multiple sythetic jet actuator in a cross flow conditions. The behaviour of SJA implemented by imposing a special kind of boundary condition on the bottom of flate plate was studied. Results have been obtained for various Reynolds numbers and were presented. These numerical results were in close agreement with [1]
One-pion transitions between heavy baryons in the constituent quark model
Single pion transitions of S wave to S wave, P wave to S wave and P wave to P
wave heavy baryons are analyzed in the framework of the Heavy Quark Symmetry
limit (HQS). We use a constituent quark model picture for the light diquark
system with an underlying SU(2N_{f}) X O(3) symmetry to reduce the number of
the HQS coupling factors required to describe these transitions. We also use
the quantum theory of angular momentum to rewrite the one-pion transitions
constituent quark model results in a more general form using the 6j- and
9j-symbols. We finally estimate the decay rates of some single pion transitions
between charm baryon states.Comment: Latex, 33 pages including 2 figures (Postscript). Some typos are
corrected with minor changes. Two references were added to the final version
which will appear in Phy. Rev.
Growth inhibitory and adjuvant therapeutic potential of aqueous extract of Triticum aestivum on MCF-7 and HeLa cells
Aim: The purpose of the present study is to evaluate the potent growth inhibitory effects of aqueous wheatgrass extract (AWE) alone and in combination with cisplatin on human breast and cervical cancer cells. Materials and Methods: The cytotoxic potential of AWE alone and in combination with cisplatin was evaluated on human breast and cervical cancer cells (MCF-7 and HeLa) by cell viability assay. Further, the mode of cell death induced by AWE was determined by nuclear morphological examination and cell cycle analysis. These effects were then correlated with the expression of genes involved in apoptosis and proliferation (cyclin D1 and Bax) by RT-PCR. Results: AWE showed dose- and time dependent selective cytotoxicity towards the cancerhighlighting its safe profile. Lower dose combinations of AWE and cisplatin induced increased growth inhibition compared with the individual drugs on both cell lines (combination index < 1) indicating strong synergistic interactions. AWE was found to induce apoptosis and arrested the cells at G0–G1 phase of the cell cycle which correlated with the modulation of expression of bax and cyclin D1 in a time-dependent manner in MCF-7 and HeLa cells. Conclusion: These results suggest that the anti-cancer potential of AWE may be due to apoptosis induction and its anti-proliferative properties. This study also provides the first evidence demonstrating synergism between AWE and cisplatin, which may enhance the therapeutic index of prevention and/or treatment of human breast and cervical cancer. Key Words: Bax, cisplatin, combination, cyclin D1, synergistic, wheatgrass
Unparticle physics effects in (Lambda_b -> Lambda + missing energy) processes
We study unparticle physics effects in (Lambda_b -> Lambda + missing energy)
decay with polarized and baryons. The sensitivity of the
branching ratio of this decay and polarizations of (Lambda_b) and (Lambda)
baryons on the scale dimension d_U and effective cut-off parameter (Lambda_U)
are discussed.Comment: 17 pages, 6 figure
On the choice of heavy baryon currents in the relativistic three-quark model
We test the sensitivity of bottom baryon observables with regard to the
choice of the interpolating three-quark currents within the relativistic
three-quark model. We have found that the semileptonic decay rates are clearly
affected by the choice of currents, whereas the asymmetry parameters show only
a very weak dependence on the choice of current.Comment: revtex, 9 page
Nonleptonic Weak Decays of Bottom Baryons
Cabibbo-allowed two-body hadronic weak decays of bottom baryons are analyzed.
Contrary to the charmed baryon sector, many channels of bottom baryon decays
proceed only through the external or internal W-emission diagrams. Moreover,
W-exchange is likely to be suppressed in the bottom baryon sector.
Consequently, the factorization approach suffices to describe most of the
Cabibbo-allowed bottom baryon decays. We use the nonrelativistic quark model to
evaluate heavy-to-heavy and heavy-to-light baryon form factors at zero recoil.
When applied to the heavy quark limit, the quark model results do satisfy all
the constraints imposed by heavy quark symmetry. The decay rates and up-down
asymmetries for bottom baryons decaying into and
are calculated. It is found that the up-down asymmetry is negative except for
decay and for decay modes with in the final
state. The prediction for
is consistent with the recent CDF measurement. We also present
estimates for decays and compare with various model
calculations.Comment: 24 pages, to appear in Phys. Rev. Uncertainties with form factor q^2
dependence are discusse
Ward Identities, B-> \rho Form Factors and |V_ub|
The exclusive FCNC beauty semileptonic decay B-> \rho is studied using Ward
identities in a general vector meson dominance framework, predicting vector
meson couplings involved. The long distance contributions are discussed which
results to obtain form factors and |V_ub|. A detailed comparison is given with
other approaches.Comment: 30 pages+four postscript figures, an Appendix adde
Department of Defense prostate cancer clinical trials consortium: A new instrument for prostate cancer clinical research
Background: In 2005, the US Department of Defense, through the US Army Medical Research and Materiel Command, Office of the Congressionally Directed Medical Research Programs, created a funding mechanism to form a clinical trials consortium to conduct phase I and II studies in prostate cancer. This is the first report of the Prostate Cancer Clinical Trials Consortium (PCCTC). Patients and Methods: The Department of Defense award supports a consortium of 10 prostate cancer research centers. Memorial Sloan-Kettering Cancer Center was awarded the Coordinating Center grant for the consortium and charged with creating an infrastructure to conduct early-phase multicenter clinical trials. Each participating center was required to introduce ≥ 1 clinical trial per year and maintain accrual of a minimum of 35 patients per year. Results: The PCCTC was launched in 2006 and now encompasses 10 leading prostate cancer research centers. Fifty-one trials have been opened, and 1386 patients have been accrued at member sites. Members share an online clinical trial management system for protocol tracking, electronic data capture, and data storage. A legal framework has been instituted, and standard operating procedures, an administrative structure, editorial support, centralized budgeting, and mechanisms for scientific review are established. Conclusion: The PCCTC fulfills a congressional directive to create a clinical trials instrument dedicated to early-phase prostate cancer studies. The member institutions have built an administrative, informatics, legal, financial, statistical, and scientific infrastructure to support this endeavor. Clinical trials are open and accruing in excess of federally mandated goals
Leptonic and Semileptonic Decays of Charm and Bottom Hadrons
We review the experimental measurements and theoretical descriptions of
leptonic and semileptonic decays of particles containing a single heavy quark,
either charm or bottom. Measurements of bottom semileptonic decays are used to
determine the magnitudes of two fundamental parameters of the standard model,
the Cabibbo-Kobayashi-Maskawa matrix elements and . These
parameters are connected with the physics of quark flavor and mass, and they
have important implications for the breakdown of CP symmetry. To extract
precise values of and from measurements, however,
requires a good understanding of the decay dynamics. Measurements of both charm
and bottom decay distributions provide information on the interactions
governing these processes. The underlying weak transition in each case is
relatively simple, but the strong interactions that bind the quarks into
hadrons introduce complications. We also discuss new theoretical approaches,
especially heavy-quark effective theory and lattice QCD, which are providing
insights and predictions now being tested by experiment. An international
effort at many laboratories will rapidly advance knowledge of this physics
during the next decade.Comment: This review article will be published in Reviews of Modern Physics in
the fall, 1995. This file contains only the abstract and the table of
contents. The full 168-page document including 47 figures is available at
http://charm.physics.ucsb.edu/papers/slrevtex.p
- …