81 research outputs found
Non-Newtonian and Gas-nonâNewtonian Liquid Flow through Elbows â CFD Analysis
Computational Fluid Dynamics (CFD) analysis for the flow of non-Newtonian and gas-non-Newtonian liquid through elbows is presented. The commercial software Fluent 6.3 has been used for the simulation. Laminar non-Newtonian pseudoplastic power law model has been used for the simulation of non-Newtonian liquid flow through elbows. For twophase flow Elurian-Elurian approach has been used for simulation. The CFD analysis have been tested from our previously published experimental results, Bandyopadhyay and Das (2007), Bandyopadhyay et al. (2000)
Collaborative Research in India: Academic Institution v/s Industry
The term âcollaborationâ is used to depict the all forms of agreement between academic institutions, corporate, universities, and any combination of such two or more parties who share the commitment to reach a common goal by using their resources available. Collaboration in Research and development (R&D) sector has been broadly used phenomenon for many years in India. In the collaborative research, the significant factors like time & cost being reduced to large extent because of sharing of the resources by the parties. Collaborative research contributes to the technological and economical development of the country. Collaboration avoids duplication in research.
But there are lots of questions, may be arising in your mind like: what is actual meaning of collaborative research? Why do industries collaborate with the academic institutions? What goes on in the collaborative research? What are the effects of collaborative research? Which type of policy do they have? and simultaneously there are lots of issues - involved in collaborative research like intellectual property rights, technology licensing, confidential agreement etc. how can all these issues be resolved before or during collaboration, so that a healthy relationship may be established for the future benefits of all the parties involved? The purpose of writing this paper is to shed the light on the solutions available of all these questions and the issues arise between the parties involved in the collaborative research program
Collaborative Research in India: Academic Institution v/s Industry
The term âcollaborationâ is used to depict the all forms of agreement between academic institutions, corporate, universities, and any combination of such two or more parties who share the commitment to reach a common goal by using their resources available. Collaboration in Research and development (R&D) sector has been broadly used phenomenon for many years in India. In the collaborative research, the significant factors like time & cost being reduced to large extent because of sharing of the resources by the parties. Collaborative research contributes to the technological and economical development of the country. Collaboration avoids duplication in research.
But there are lots of questions, may be arising in your mind like: what is actual meaning of collaborative research? Why do industries collaborate with the academic institutions? What goes on in the collaborative research? What are the effects of collaborative research? Which type of policy do they have? and simultaneously there are lots of issues - involved in collaborative research like intellectual property rights, technology licensing, confidential agreement etc. how can all these issues be resolved before or during collaboration, so that a healthy relationship may be established for the future benefits of all the parties involved? The purpose of writing this paper is to shed the light on the solutions available of all these questions and the issues arise between the parties involved in the collaborative research program
Implications of recent solar neutrino observations: an analysis of charged current data
We have analysed the recent results from the observation of charged current
\nu_e d \to e^- p p events from solar neutrinos by the Sudbury Neutrino
Observatory SNO assuming neutrino oscillations with three active flavours. The
data seem to prefer a low mass-squared difference and large mixing angle
solution (the so-called LOW solution) in (12) parameter space. However, when
combined with the Gallium charged current interaction data from Gallex and GNO,
distinct (1\sigma) allowed regions corresponding to the large mixing angle
(LMA) and small mixing angle (SMA) appear while the LOW solution is disfavoured
upto 3\sigma standard deviation. The physical electron neutrino survival
probability corresponding to these best fit solutions are then determined and
analysed for their energy dependence.Comment: 16 pages Latex file, with 5 epsf figures; one reference adde
SN1987A and the Status of Oscillation Solutions to the Solar Neutrino Problem (including an appendix discussing the NC and day/night data from SNO)
We study neutrino oscillations and the level-crossing probability PLZ in
power-law potential profiles A(r)\propto r^n. We give local and global
adiabaticity conditions valid for all mixing angles theta and discuss different
representations for PLZ. For the 1/r^3 profile typical of supernova envelopes
we compare our analytical to numerical results and to earlier approximations
used in the literature. We then perform a combined likelihood analysis of the
observed SN1987A neutrino signal and of the latest solar neutrino data,
including the recent SNO CC measurement. We find that, unless all relevant
supernova parameters (released binding energy, \bar\nu_e and \bar\nu_{\mu,\tau}
temperatures) are near their lowest values found in simulations, the status of
large mixing type solutions deteriorates considerably compared to fits using
only solar data. This is sufficient to rule out the vacuum-type solutions for
most reasonable choices of astrophysics parameters. The LOW solution may still
be acceptable, but becomes worse than the SMA-MSW solution which may, in some
cases, be the best combined solution. On the other hand the LMA-MSW solution
can easily survive as the best overall solution, although its size is generally
reduced when compared to fits to the solar data only.Comment: 31 pages, 32 eps figures; 5 pages, 5 eps figures addendum in v2,
discussing the recent SNO NC data and changes in SN paramete
Breaking Eight-fold Degeneracies in Neutrino CP Violation, Mixing, and Mass Hierarchy
We identify three independent two-fold parameter degeneracies (\delta,
\theta_{13}), sgn(\delta m^2_{31}) and (\theta_{23}, \pi/2-\theta_{23})
inherent in the usual three-neutrino analysis of long-baseline neutrino
experiments, which can lead to as much as an eight-fold degeneracy in the
determination of the oscillation parameters. We discuss the implications these
degeneracies have for detecting CP violation and present criteria for breaking
them. A superbeam facility with a baseline at least as long as the distance
between Fermilab and Homestake (1290 km) and a narrow band beam with energy
tuned so that the measurements are performed at the first oscillation peak can
resolve all the ambiguities other than the (\theta_{23}, \pi/2-\theta_{23})
ambiguity (which can be resolved at a neutrino factory) and a residual (\delta,
\pi-\delta) ambiguity. However, whether or not CP violation occurs in the
neutrino sector can be ascertained independently of the latter two ambiguities.
The (\delta,\pi-\delta) ambiguity can be eliminated by performing a second
measurement to which only the \cos\delta terms contribute. The hierarchy of
mass eigenstates can be determined at other oscillation peaks only in the most
optimistic conditions, making it necessary to use the first oscillation
maximum. We show that the degeneracies may severely compromise the ability of
the proposed SuperJHF-HyperKamiokande experiment to establish CP violation. In
our calculations we use approximate analytic expressions for oscillation
probabilitites that agree with numerical solutions with a realistic Earth
density profile.Comment: Revtex (singlespaced), 35 pages, 15 postscript figures, uses
psfig.st
Three-flavor solar neutrino oscillations with terrestrial neutrino constraints
We present an updated analysis of the current solar neutrino data in terms of
three-flavor oscillations, including the additional constraints coming from
terrestrial neutrino oscillation searches at the CHOOZ (reactor),
Super-Kamiokande (atmospheric), and KEK-to-Kamioka (accelerator) experiments.
The best fit is reached for the subcase of two-family mixing, and the
additional admixture with the third neutrino is severely limited. We discuss
the relevant features of the globally allowed regions in the oscillation
parameter space, as well as their impact on the amplitude of possible
CP-violation effects at future accelerator experiments and on the
reconstruction accuracy of the mass-mixing oscillation parameters at the
KamLAND reactor experiment.Comment: 10 pages + 8 figure
Quasi-energy-independent solar neutrino transitions
Current solar, atmospheric, and reactor neutrino data still allow oscillation
scenarios where the squared mass differences are all close to 10^-3 eV^2,
rather than being hierarchically separated. For solar neutrinos, this situation
(realized in the upper part of the so-called large-mixing angle solution)
implies adiabatic transitions which depend weakly on the neutrino energy and on
the matter density, as well as on the ``atmospheric'' squared mass difference.
In such a regime of ``quasi-energy-independent'' (QEI) transitions,
intermediate between the more familiar ``Mikheyev-Smirnov-Wolfenstein'' (MSW)
and energy-independent (EI) regimes, we first perform analytical calculations
of the solar nu_e survival probability at first order in the matter density,
beyond the usual hierarchical approximations. We then provide accurate,
generalized expressions for the solar neutrino mixing angles in matter, which
reduce to those valid in the MSW, QEI and EI regimes in appropriate limits.
Finally, a representative QEI scenario is discussed in some detail.Comment: Title changed; text and acronyms revised; results unchanged. To
appear in PR
Constraining neutrino oscillation parameters with current solar and atmospheric data
We analyze the impact of recent solar, atmospheric and reactor data in the
determination of the neutrino oscillation parameters, taking into account that
both the solar nu_e and the atmospheric nu_mu may convert to a mixture of
active and sterile neutrinos. We use the most recent global solar neutrino
data, including the 1496-day Super-K neutrino data sample, and we investigate
in detail the impact of the SNO neutral current, spectral and day/night data by
performing also an analysis using only the charged current rate from SNO. The
implications of the first 145.1 days of KamLAND data on the determination of
the solar neutrino parameters are also discussed in detail. We confirm the
clear preference of solar+reactor data for the pure active LMA-MSW solution of
the solar neutrino problem, and obtain that the LOW, VAC, SMA and Just-So^2
solutions are disfavored with a Delta_chi^2 = 22, 22, 36, 44, respectively.
Furthermore, we find that the global solar data constrains the admixture of a
sterile neutrino to be less than 43% at 99% CL. By performing an improved fit
of the atmospheric data, we also update the corresponding regions of
oscillation parameters. We find that the recent atmospheric Super-K (1489-day)
and MACRO data have a strong impact on constraining a sterile component in
atmospheric oscillations: if the nu_mu is restricted to the atmospheric mass
states only a sterile admixture of 16% is allowed at 99% CL, while a bound of
35% is obtained in the unconstrained case. Pure sterile oscillations are
disfavored with a Delta_chi^2 = 34.6 compared to the pure active case.Comment: 28 pages, LaTeX file using RevTEX4, 12 figures and 3 tables included.
Improved version including the new KamLAND dat
Can a CPT Violating Ether Solve ALL Electron (Anti)Neutrino Puzzles?
Assuming that CPT is violated in the neutrino sector seems to be a viable
alternative to sterile neutrinos when it comes to reconciling the LSND anomaly
with the remainder of the neutrino data. There are different (distinguishable)
ways of incorporating CPT violation into the standard model, including
postulating m different from \bar{m}. Here, I investigate the possibility of
introducing CPT violation via Lorentz-invariance violating effective operators
(``Ether'' potentials) which modify neutrino oscillation patterns like ordinary
matter effects. I argue that, within a simplified two-flavor like oscillation
analysis, one cannot solve the solar neutrino puzzle and LSND anomaly while
still respecting constraints imposed by other neutrino experiments, and comment
on whether significant improvements should be expected from a three-flavor
analysis. If one turns the picture upside down, some of the most severe
constrains on such CPT violating terms can already be obtained from the current
neutrino data, while much more severe constraints can arise from future
neutrino oscillation experiments.Comment: 10 pages, 1 eps figure; version to appear in PRD. Comment added,
mistake corrected, results and conclusions unchange
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