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Jeganlal G.,LPSC | Umer H.M.,LPSC
Advanced Materials Research | Year: 2014

This paper gives the effects of single and multiple pore on the strength of AA2219 welds. Single and double pores are created on welded specimens and tested to study the effects. Also finite element analysis carriedout to correlate the experimental results with theory. © (2014) Trans Tech Publications, Switzerland.

PubMed | German Electron Synchrotron, British Petroleum, Ecole Polytechnique Federale de Lausanne, University of Mainz and 4 more.
Type: Journal Article | Journal: Journal of research of the National Institute of Standards and Technology | Year: 2016

We studied the neutron quantum states in the potential well formed by the Earths gravitational field and a horizontal mirror. The estimated characteristic sizes of the neutron wave functions in two lowest quantum states correspond to their expectations with an accuracy of 25 %. The spatial density distribution in a standing neutron wave above a mirror was measured for a set of a few lowest quantum states. A position-sensitive neutron detector with an extra high spatial resolution of 1 m to 2 m was developed and tested for this particular task. Although this experiment was not designed or optimized to search for an additional short-range force, nevertheless it allowed us to slightly improve the published boundary in the nanometer range of characteristic distances. We studied systematical uncertainties in the chosen flow-through method as well as the feasibility to improve further the accuracy in this experiment.

News Article | March 23, 2016

The New Horizons team used "principal component analysis" to get this false-color image that highlights the different regions of Pluto. Credit: NASA/New Horizons/JHAPL The New Horizons probe revealed the surface features of Pluto in rich detail when it reached the dwarf planet in July 2015. Some of the features look like snapshots of rivers and lakes that are locked firmly in place by Pluto's frigid temperatures. But now scientists studying the data coming back from New Horizons think that those frozen lakes and rivers could once have been liquid nitrogen. Pluto has turned out be a surprisingly active place. New Horizons has shown us what might be clouds in Pluto's atmosphere, mountains that might be ice volcanoes, and cliffs made of methane ice that melt away into the plains. If there were oceans and rivers of liquid nitrogen on the surface of Pluto, that would fit in with our evolving understanding of Pluto as a much more active planet than we thought. Richard Binzel, a New Horizons team member from MIT, thinks that lakes of liquid nitrogen could have existed some 800 or 900 million years ago. It all stems from Pluto's axial tilt, which at 120 degrees is much more pronounced than Earth's relatively mild 23 degree tilt. And computer modelling suggests that this tilt could have even been more extreme many millions of years ago. The result of this extreme tilt is that much more of Pluto's surface would have been exposed to sunlight. That may have warmed Pluto enough to allow liquid nitrogen to flow over the planet's surface. These kinds of changes to a planet's axial tilt, (and precession and eccentricity) affect a planet's climate in what are called Milankovitch cycles. The same cycles are thought to have a similar effect on Earth's climate, though not as extreme as on Pluto. According to Binzel, Pluto could be somewhere in between its temperature extremes, meaning that if Pluto will ever be warm enough for liquid nitrogen again, it could be hundreds of millions of years from now. "Right now, Pluto is between two extreme climate states," Binzel says. Alan Stern is a planetary scientist at the Southwest Research Institute, and New Horizons' Principal Investigator. He thinks that these long-cycle climate changes could have a very pronounced effect on Pluto, which has a nitrogen-rich atmosphere. In ancient times, Pluto's atmosphere could have been more dense than Mars'. "This opens up the possibility that liquid nitrogen may have once or even many times flowed on Pluto's surface," he said. More data from New Horizons is still on its way. About half is yet to arrive. That data, and further analysis, might discredit the fledgling idea that Pluto had and will have again lakes of liquid nitrogen. "We are just beginning to understand the long-term climate of Pluto," said Binzel. This week is the 47th Lunar and Planetary Science Conference (LPSC) in Houston. Members of the New Horizons team will be presenting almost 40 reports on Pluto and its system of moons at this conference. Stern's lecture, titled "The Exploration of Pluto," will be archived online at Explore further: Pluto sweats, and 5 other things you didn't know about the dwarf planet

News Article | November 17, 2016

BATON ROUGE, La., Nov. 17, 2016 /PRNewswire/ -- Entergy Louisiana, LLC today received approval from the Louisiana Public Service Commission to build a new natural gas-fired, combined-cycle power plant in St. Charles Parish. The LPSC vote clears the way for Entergy Louisiana to move...

Chatterjee A.,Harish Chandra Research Institute | Drees M.,University of Bonn | Kulkarni S.,LPSC
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

In the framework of the minimal cosmological standard model, the ΛCDM model, the dark matter density is now known within an error of a few percent; this error is expected to shrink even further once PLANCK data are analyzed. Matching this precision by theoretical calculations implies that at least leading radiative corrections to the annihilation cross section of the dark matter particles have to be included. Here we compute one kind of large corrections in the context of the minimal supersymmetric extension of the Standard Model: corrections associated with two-point function corrections on chargino and neutralino (collectively denoted by χ) lines. These can be described by effective χ-fermion-sfermion and χ-χ-Higgs couplings. We also employ one-loop corrected χ masses, using a recently developed version of the on-shell renormalization scheme. The resulting correction to the predicted dark matter density depends strongly on parameter space, but it can easily reach 3%. © 2012 American Physical Society.

Ledroit-Guillon F.,LPSC
Nuclear Physics B - Proceedings Supplements | Year: 2010

We discuss how ATLAS has been preparing for the analysis of the first fb-1 of good data at 14 TeV in view of discovering new physics beyond the Standard Model. We show some ideas developed for understanding the backgrounds and we present as realistic as possible estimates of the reach of the experiment. © 2010 Elsevier B.V.

Shine S.R.,IIST | Kumar S.S.,LPSC | Suresh B.N.,ISRO HQs
ASME 2012 Gas Turbine India Conference, GTINDIA 2012 | Year: 2012

Experimental and numerical investigations are carried out to analyze the effect of tangential coolant injection on overall film cooling performance in a cylindrical test section simulating a high curvature surface. Experiments are conducted using hot air as core gas and nitrogen gas as coolant injected through cylindrical holes inclined at 30-degrees to the core gas flow. A three-dimensional multi-species numerical model is formulated using the finite volume formulation and is validated using the obtained experimental data. Simulation results indicate that an optimum blowing ratio exists for which the effectiveness is maximum. The conjugate effectiveness is observed to be higher than adiabatic effectiveness values except in the vicinity of injection owing to the wall conduction effects. Numerical analysis performed with an annular slot placed at the exit of the coolant holes showed an increase in the effectiveness by 21 % compared to the base hole. It is expected that the knowledge acquired in this study has the potential to support new ideas in gas turbine film cooling techniques such as turbine casing film cooling. Copyright © 2012 by ASME.

Abraham A.M.,LPSC | Suresh M.S.,LPSC
International Journal of Applied Engineering Research | Year: 2014

Flow dynamics in a gas turbine is highly complex and is a challenging subject of research to the turbo machinery community. Studies show that axial gap between stationary blades and rotating blades in a turbine plays a major role in the performance of a turbine. This paper numerically analyses the effect of axial gap on the flow dynamics of a gas turbine consisting of a set of nozzle blades, two rows of rotor blades and a single row of stator blades. A fixed value of mass flow rate at inlet and pressure at exit are given as boundary conditions in all cases which helps to effectively assess the impact of changing axial gaps on the flow dynamics. Study also analyses the change in rotor torque and efficiency with increase in axial gap. © Research India Publications.

Weydert C.,LPSC
Nuovo Cimento della Societa Italiana di Fisica C | Year: 2010

Accurate predictions for both signal and background events at the LHC are of paramount importance in order to confirm even the smallest deviations from Standard Model predicitions. Next-to-leading order Monte Carlo event generators are an essential tool to reach that goal. Concerning the charged Higgs boson, NLO calculations of the production cross section already exist. Reiterating the calculation using a subtraction formalism enables us to implement the cross section into Monte Carlo generators, which can then be used by experiments. © Societ̀ Italiana di Fisica.

Clement B.,LPSC
EPJ Web of Conferences | Year: 2013

The main purpose of these lectures is to provide the reader with the tools needed to data analysis in the framework of physics experiments. Basic concepts are introduced together with examples of application in experimental physics. The lecture is divided into two parts: probability and statistics. It is build on the introduction from "data analysis in experimental sciences" given in [1] © Owned by the authors, published by EDP Sciences, 2013.

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