Search results for "Large range"
showing 10 items of 15 documents
Field-free molecular alignment of asymmetric top molecules using elliptically polarized laser pulses
2008
International audience; We show theoretically that a short specific elliptically polarized laser pulse driving an asymmetric top molecule can induce postpulse revivals of three-dimensional (3-D) alignment. By choosing the field ellipticity resulting in the best compromise between the alignment of two molecular axes, we demonstrate that efficient 3-D alignment can be achieved at low temperature. In the experiment, the field-free alignment of moderately cool ethylene molecules is probed by using a technique based on the optical Kerr effect. Control of 3-D field-free alignment opens the door to a large range of applications in chemistry as well as in molecular optics.
LARGE-SCALE SIMULATIONS IN CONDENSED MATTER PHYSICS —THE NEED FOR A TERAFLOP COMPUTER
1992
The introduction of vector processors {“supercomputers” with a performance in the range of 109 floating point operations (1 GFLOP) per second} has had an enormous impact on computational condensed matter physics. The possibility of a substantially enhanced performance by massively parallel processors (“teraflop” machines with 1012 floating point operations per second) will allow satisfactory treatment of a large range of important scientific problems which have to a great extent thus far escaped numerical resolution. The present paper describes only a few examples (out of a long list of interesting research problems!) for which the availability of “teraflops” will allow spectacular progres…
Experimental and Numerical Analysis of a Cross-Flow Turbine
2016
An important component of the management cost of aqueducts is the energy costs. Part of these costs can be recovered by transforming some of the many existing energy dissipations into electric energy by means of economical turbines. This paper describes an experimental study that has been carried out in order to (1) test the performance of an economical cross-flow turbine that maintains high efficiency within a large range of water discharges, and (2) validate a new approximate formula relating main inlet velocity to inlet pressure. It is demonstrated that the proposed formula, on the basis of some simplifying assumptions, exactly links inlet velocity to inlet pressure with any possible geo…
119Sn-NMR Study on Bis(Tri-Butyltin)oxide Derivatives of Phenolic Compounds
1991
Abstract 119Sn-NMR spectroscopy has been utilized in the characterization of various phenolics as their bis(tri-butyltin)oxide, TBTO, derivatives. The present method has been applied both for determination of simple model compounds and for characterization of complex biopolymeric material originating from spent bleach liquor fractionated by an ultrafiltration technique. Based on the large range of 119Sn-NMR chemical shifts of TBTO derivatives of the phenolic compounds and the similar relaxation properties of 119Sn nuclei located in those derivatives, both qualitative and quantitative analytical conclusions can be drawn.
Propeller Flaps: A Review of Indications, Technique, and Results
2014
In the last years, propeller flaps have become an appealing option for coverage of a large range of defects. Besides having a more reliable vascular pedicle than traditional flap, propeller flaps allow for great freedom in design and for wide mobilization that extend the possibility of reconstructing difficult wounds with local tissues and minimal donor-site morbidity. They also allow one-stage reconstruction of defects that usually require multiple procedures. Harvesting of a propeller flap requires accurate patient selection, preoperative planning, and dissection technique. Complication rate can be kept low, provided that potential problems are prevented, promptly recognized, and adequate…
Thermodynamisches verhalten, expansionskoeffizient und viskositätszahl von polystyrol in tetrahydrofuran
1968
Streulichtmessungen ergeben, das Polystyrollosungen in Tetrahydrofaran stark exothermisch sind; der 2. Virialkoeffizient des osmotischen Druckes A2 wird uberwiegend durch den Enthalpieterm A2,H bestimmt. Der Expansionskoeffizient gehorcht der (α5−α3)-Beziehung mit der Konstante von STOCKMAYER und die h(z)-Funktion der Gleichung von CASASSA. Die Viskositatszahl [η] wird durch die Gleichung von KURATA und YAMAKAWA erfast. Mit den drei Parametern β/M, K0 = r/M und b/M (b = hydrodynamischer Durchmesser) lassen sich A2, α, [η] und der Tragheitsradius r uber einen grosen Molekulargewichts-bereich in guter Ubereinstimmung mit den Meswerten berechnen (vgl. Abb. 3). Light scattering measurements of …
The formal redox potential of the Yb(III,II) Couple at 0°C in 3.22 molal NaCl medium
2004
Following our previous investigations on aqueous solutions of hypooxidized and iperoxidized species, we managed, by lowering the temperature of the solutions to 0 degrees C, to obtain, by electrochemical methods, Yb(II) and Yb(III) mixtures, enough stable to determine by a potentiometric method the formal redox potential of the Yb(IlI, II) couple. Its value, in a large range of total Ytterbium concentration, is -1233 +/- 3 mV against the molal hydrogen electrode in the 3.22 m NaCl medium.
A naïve approach to speed up portfolio optimization problem using a multiobjective genetic algorithm
2012
a b s t r a c t Genetic algorithms (GAs) are appropriate when investors have the objective of obtaining mean-variance (VaR) efficient frontier as minimising VaR leads to non-convex and non-differential risk-return optimisation problems. However GAs are a time-consuming optimisation technique. In this paper, we propose to use a naive approach consisting of using samples split by quartile of risk to obtain complete efficient frontiers in a reasonable computation time. Our results show that using reduced problems which only consider a quartile of the assets allow us to explore the efficient frontier for a large range of risk values. In particular, the third quartile allows us to obtain efficie…
Dark matter synchrotron emission and radio observations
2012
We compute the synchrotron emission induced by electrons produced by DM annihilations inside our galaxy. The signal is compared with observations in a large range of frequencies, from 22 MHz up to 1420 MHz. We set constraints on the DM mass and annihilation cross-section and highlight the impact of astrophysical uncertainties.
γδ T cells as a potential tool in colon cancer immunotherapy
2014
γδ T cells are capable of recognizing tumor cells and exert potent cellular cytotoxicity against a large range of tumors, including colon cancer. However, tumors utilize numerous strategies to escape recognition or killing by patrolling γδ T cells, such a downregulation of NKG2D ligands, MICA/B and ULBPs. Therefore, the combined upregulation of T-cell receptorand NKG2D ligands on tumor cells and induction of NKG2D expression on γδ T cells may greatly enhance tumor killing and unlock the functions of γδ T cells. Here, we briefly review current data on the mechanisms of γδ T-cell recognition and killing of colon cancer cells and propose that γδ T cells may represent a promising target for the…