Physics Commons^™

The Evidence Of The Mode Selectivity Of The Infrared Predissociation Reaction Of The Hydrogen Bonds In The Aniline–Water–Pyrrole Cluster Cation, Taisuke Nakanaga, Naveed Piracha, Fumiyuki Ito

Naveed K. Piracha

The infrared spectrum of aniline–water–pyrrole cluster cation has been measured in the 3 μm region. Four strong vibrational bands were observed at 3313, 3515, 3637, and 3721cm−1, and the cluster dissociated into fragments in two reaction paths, AWP+→AW++P and AWP+→AP++W (A: aniline, W: water, P: pyrrole) when it absorbed an infrared photon. The branching ratio (AW+/AP+) has been determined to be 0.20±0.02 for the NH stretching vibration of aniline (3313cm−1, hydrogen-bonded to pyrrole) and 0.14±0.03 for the other three bands. This vibrational mode dependence should be due to the fast energy transfer from the NH to the intermolecular vibration through …

Transport Properties Of Bi2−Xinxse3 Single Crystals., J. Navrátil, T. Plecháček, J. Horák, S. Karamazov, P. LošŤÁK, Jeffrey Dyck, W. Chen, C. Uher

Jeffrey Dyck

The paper reports on the temperature dependence of the electrical and thermal conductivity, Hall constant, and Seebeck coefficient of Bi2−xInxSe3 (x=0, 0.2, 0.4) single crystals measured over the temperature range from 2 to 300 K. One single-valley conduction band model is used to interpret relations among transport coefficients. The data analysis relies on the use of a mixed carrier scattering mechanism consisting of acoustic scattering and scattering on ionized impurities. The effect of In incorporation into the Bi2Se3 crystal lattice on the individual components of thermal conductivity is evaluated and discussed. Copyright 2001 Academic Press.

Anomalous Barium Filling Fraction And N-Type Thermoelectric Performance Of Ba[Sub Y]Co[Sub 4]Sb[Sub 12]., L. Chen, T. Kawahara, X. Tang, T. Goto, T. Hirai, Jeffrey Dyck, W. Chen, C. Uher

Jeffrey Dyck

Barium-filled skutterudites BaCoSb with an anomalously large filling fraction of up to y=0.44 have been synthesized. The lattice parameters increase linearly with Ba content. Magnetic susceptibility data show that BaCoSb is paramagnetic, which implies that some of the Co atoms in BaCoSb have acquired a magnetic moment. The presence of the two different valence states of Co (Co3+ and Co2+) leads to the anomalously large barium filling fraction even without extra charge compensation. All samples show n-type conduction. The electrical conductivity increases with increasing the Ba filling fraction. The lattice thermal conductivity of BaCoSb is significantly depressed as compared to …

Exact Topological Density In The Lattice Skyrme Model, Alec Schramm, Benjamin Svetitsky

Alec J Schramm

We propose using the Skyrme model on a lattice as an effective field theory of meson–baryon interactions. To this end we construct a local topological density that involves the volumes of tetrahedra in the target space S3 and we make use of Coxeter’s formula for the Schla¨fli function to implement it. We calculate the mean-square radius of a skyrmion in the three-dimensional Skyrme model, and find some surprises.

Third Generation Seesaw Mixing With New Vector-Like Weak-Doublet Quarks, Marko Popovic

Marko B. Popovic

We present a class of models with a third generation seesaw mixing with new vectorlike weak-doublet quarks. We analyze a low-energy phenomenology and present several strong dynamics, high-energy realizations of these models. In the top-color-type scenario, named top-bottom color, we obtain an effective, composite two Higgs doublet model where the third generation isospin splitting is introduced via tilting interactions related to the broken non-Abelian gauge groups @i.e., without strong, triviality-sensitive U~1! groups#. In addition, we discuss t t ¯ production at the Next Linear Collider and suggest how one can experimentally observe and distinguish between the weak-doublet and the weak-singlet …

Russian Summary Of Phd Dissertation, Serge Y. Kalmykov

Serge Youri Kalmykov

Notarized English Translation Of The Author's Summary Of Phd Dissertation, Serge Y. Kalmykov

Serge Youri Kalmykov

Stimulated Raman Scattering Of Short Intense Laser Pulses In Plasmas, Serge Y. Kalmykov

Serge Youri Kalmykov

Excitation Of Ion-Acoustic-Like Waves By Subcritical Currents In A Plasma Having Equal Electron And Ion Temperatures, Erick Agrimson, Nicola D'Angelo, Robert L. Merlino

Erick Agrimson

No abstract provided.

On The Effect Of Electron Plasma Waves With Relativistic Phase Velocity On Large-Angle Stimulated Raman Scattering Of Modulated Short Laser Pulse In Plasmas, Nikolai E. Andreev, Serguei Y. Kalmykov

Serge Youri Kalmykov

Suppression of a large-angle stimulated Raman scattering (LA-SRS) of a short modulated (two-frequency) laser pulse in a transparent plasma in the presence of a linear long-wavelength electron plasma wave (LW EPW) having relativistic phase velocity is considered under the conditions of weak and strong coupling. The laser spectrum includes two components with a frequency shift equal to the frequency of the LW EPW. The mutual influence of different spectral components of a laser on the SRS under a given angle in the presence of the LW EPW is examined.

Investigation Of The Structure Of T He Ternary Cluster Of Aniline−Water−Tetrahydrofuran And Its Cation By Infrared Depletion Spectroscopy, Taisuke Nakanaga, Naveed Piracha, Fumiyuki Ito

Naveed K. Piracha

No abstract provided.

A2bi8se1 3 (A = Rb, Cs), Csbi3.67se6, And Babi2< /Inf>Se4: New Ternary Semiconducting Bismuth Selenides, Lykourgis Iordanidis, Paul Brazis, Theodora Kyratsi, John Irel, Melissa Lane, Carl Kannewurf, Wei Chen, Jeffrey Dyck, Ctirad Uher, Nishant Ghelani, Tim Hogan, Mercouri Kanatzidis

Jeffrey Dyck

No abstract provided.

Simple Relationships For The Estimation Of Melting Temperatures Of Homologous Series, James S. Chickos, Gary Nichols

James Chickos

No abstract provided.

The Influence Of Ni On The Transport Properties Of Cosb3, C. Uher, Jeffrey Dyck, W. Chen, G. Meisner, J. Yang

Jeffrey Dyck

The effect of Ni doping on the Co site of the binary skutterudite CoSb3 is investigated. We measured resistivity, Hall effect, magnetoresistance, thermopower, thermal conductivity, and magnetization of a series of samples of the form Co1-xNixSb3 with x in the range x=0 to x=0.01. We find that Ni takes the tetravalent state Ni4+, assumes the d6 electronic configuration for the lower energy non-bonding orbitals, and gives an electron to the conduction band. Ni doping dramatically suppresses the thermal conductivity, changes the temperature dependence of the thermopower, and increases the carrier concentration. Low temperature anomalies in thermopower, Hall coefficient and magnetoresistance …

Low Temperature Thermoelectric Properties Of Ni Doped N-Type Filled Skutterudites Ba0.3co4sb12 ., W. Chen, Jeffrey Dyck, C. Uher, L. Chen, X. Tang, T. Hirai

Jeffrey Dyck

n-type Ba filled skutterudites doped with Ni, Ba0.3Ni xCo4-xSb12 with 0⩽x⩽0.2, have been synthesized and the Seebeck coefficient, thermal conductivity, electrical resistivity and Hall coefficient have been measured. ZT of 1.2 has been achieved at 800 K with x=0.05. The thermal conductivity data are fitted and the rattling effect of the Ba atoms is identified through a resonance scattering term. The Hall mobility is studied and a mixed scattering mechanism of acoustic phonons and ionized impurities based on a single, rigid band picture is presented. The role of Ni atoms in enhancing the thermoelectric performance is discussed

Multi-Filling Approach For The Improvement Of Thermoelectric Properties Of Skutterudites., L. Chen, X. Tang, T. Kawahara, Jeffrey Dyck

Jeffrey Dyck

Several skutterudite antimonides filled with atoms of different kinds, (Ba, M)yCo4Sb12 (M=Ce, La, Sr), have been synthesized by the combination of solid state reaction and melting methods. Thermal conductivity of (Ba,Sr)yCo4 Sb12 samples shows a behavior similar to that of BayCo4Sb12. Adding a small amount of Ce or La to the BayCo4Sb12 system is effective in further reducing the lattice thermal conductivity. The difference in the ionic radii of the two co-filler atoms is the most sensitive factor for scattering of phonons. The multi-filled (Ba, M)yCo4Sb12 (M=Sr, Ce, La) show lower Seebeck coefficients as compared to the single-filled BayCo 4Sb12 …

High-Temperature Thermoelectric Properties Of N-Type Baynixco4-Xsb12., X. Tang, L. Zhang, R. Yuan, L. Chen, T. Goto, T. Hirai, Jeffrey Dyck, W. Chen, C. Uher

Jeffrey Dyck

Effects of Ba filling fraction and Ni content on the thermoelectric properties of n-type BayNixCo4-xSb12 (x = 0-0.1, y = 0.-0.4) were investigated at temperature range of 300 to 900 K. Thermal conductivity decreased with increasing Ba filling fraction and temperature. When y was fixed at 0.3, thermal conductivity decreased with increasing Ni content and reached a minimum value at about x = 0.05. Lattice thermal conductivity decreased with increasing Ni content, monotonously (y ≤ 0.1). Electron concentration and electrical conductivity increased with increasing Ba filling fraction and Ni content. Seebeck coefficient increased with increasing temperature and decreased with increasing …

Femtosecond Polarization Detection Using High-Speed Pulse Shaping, D. Keusters, Peifang Tian, W. Warren

Peifang Tian

This book presents the latest advances in ultrafast science, including ultrafast laser and measurement technology as well as studies of ultrafast phenomena. Pico- and femtosecond processes relevant in physics, chemistry, biology and engineering are presented. Ultrafast technology has had a profound impact in a wide range of applications, among them imaging, material diagnostics and transformation and high-speed optoelectronics. This book summarizes the results presented at the 12th Ultrafast Phenomena Conference and reviews the state of the art of this important and rapidly advancing field.

Preparation And Some Physical Properties Of Tetradymite-Type Sb2te3 Single Crystals Doped With Cds., P. LošŤÁK, Č. Drašar, A. Krejc ̆ Ova, L. Beneš, Jeffrey Dyck, W. Chen, C. Uher

Jeffrey Dyck

Single crystals of Sb2Te3 doped with CdS were prepared by a modified Bridgman method from the elements Sb and Te of 5N purity and the CdS compound of 4.5N purity. Samples were characterized by X-ray diffraction and by measurement of reflectance in the plasma resonance frequency region at room temperature. Furthermore, we made measurements of temperature dependence of the electrical resistivity, Hall and Seebeck coefficients, and thermal conductivity in the temperature range of 4.2–300K. In the process of crystal growth, CdS dissociated and it was assumed that the Cd-atoms formed substitutional defects in the Sb-sublattice (CdSb′) while the S-atoms formed …

Gyroscope Precession And General Relativity, Br Holstein

Barry R Holstein

Precession of a gyroscope in the presence of a gravitational field is of considerable interest, on account of the soon to be launched satellite test and because of its connection to Mach's principle. Nevertheless, this topic is not generally covered in the curriculum because of the mathematical sophistication required. We examine some of the simple physics involved and argue that by examining simple graviton-elementary particle couplings one can easily understand this phenomenon.

Synthesis And High Temperature Thermoelectric Properties Of N-Type Baynixco4-Xsb12., X. Tang, L. Chen, T. Goto, Jeffrey Dyck

Jeffrey Dyck

Single-phase filled skutterudite compounds BayNx Co4-xSb12 (x=0-0.1, y=0-0.4) were synthesized by a two-step solid state reaction. Effects of Ba filling fraction and Ni content on the thermoelectric properties of n-type Ba yNixCo4-xSb12 were investigated. Thermal conductivity decreased with increasing Ba filling fraction and temperature. When barium filling fraction (y) was fixed at 0.3, the thermal conductivity decreased with increasing Ni content, and reached a minimum value at about x=0.05. Electron concentration and electrical conductivity increased with increasing Ba filling fraction and Ni content. Seebeck coefficient increased with increasing temperature, and decreased with increasing Ba filling fraction and Ni content. A …

Thermoelectric Properties Of Yb-Filled And Sn-Compensated Skutterudites ., Jihui Yang, Gregory Meisner, Wei Chen, Jeffrey Dyck, Ctirad Uher

Jeffrey Dyck

The effect of alloying tin on the antimony site of ytterbium-filled skutterudites is examined. We performed measurements of Hall effect, electrical resistivity, Seebeck coefficient and thermal conductivity on the series Yb0.5Co4Sb12-x Snx, with x=0.5, 0.6, 0.8 and 0.83. We find that the substitution of tin does not alter the position of the Fermi level with respect to the conduction band of these heavily doped semiconducting samples, but rather it gives rise to a p-type band. Experimental data for x=0.83 can be understood in the context of a two-carrier electrical conduction. Thermal conductivity of these ytterbium-filled skutterudites is significantly suppressed with …

Transport And Magnetic Properties Of Co1-Xnixsb3 With X Less Than 0.01, Jeffrey Dyck, W. Chen, Y. Yang, G. Meisner, C. Uher

Jeffrey Dyck

The filled skutterudite compounds based on the binary skutterudite CoSb3 are currently being investigated for their potential application as thermoelectric materials. One route to optimization of these compounds is by doping on the Co site. An obvious candidate for an n-type dopant is Ni, because it has one more electron in its valence shell than Co. We present electrical resistivity, thermopower, Hall effect and magnetic susceptibility measurements on polycrystalline, n-type Co1-xNixSb3 with x less than 0.01. A model which takes into account conduction of electrons residing in the conduction band in addition to hopping conduction within an impurity "band" formed …

Comment On "The Van Der Waals Interaction," By Barry R. Holstein [Am. J. Phys. 69 (4), 441-449 (2001)], Br Holstein

Barry R Holstein

No abstract provided.

Determination Of The Quadratic Slope Parameter In Eta -> 3 Pi(0) Decay, Wb Tippens, S Prakhov, Ce Allgower, V Bekrenev, E Berger, Wj Briscoe, M Clajus, Jr Comfort, K Craig, A Efendiev, D Grosnick, Br Holstein, Gm Huber, D Isenhower, N Knecht, D Koetke, A Koulbardis, N Kozlenko, S Kruglov, Gj Lolos, I Lopatin, Dm Manley, A Marusic, R Manweiler, S Mcdonald, Bmk Nefkens, J Olmsted, Z Papandreou, N Phaisangittisakul, Jw Price, M Pulver, Af Ramirez, Me Sadler, A Shafi, H Spinka, S Stanislaus, A Starostin, Hm Staudenmaier

Barry R Holstein

We have determined the quadratic slope parameter α for η→3π0 to be α = -0.031(4) from a 99% pure sample of 106η→3π0 decays produced in the reaction π-p→nη close to the η threshold using the Crystal Ball detector at the AGS. The result is four times more precise than the present world data and disagrees with current chiral perturbation theory calculations by about four standard deviations.

Comment On "A Check Of Prigogine's Theorem Of Minimum Entropy Production In A Rod In A Nonequilibrium Stationary State", Peter Palffy-Muhoray

Peter Palffy-Muhoray

No abstract provided.

Optically Induced Periodic Structures In Smectic-C Liquid Crystals, Antal Jákli, A. Vajda, E. Benkler, Janossy, Peter Palffy-Muhoray

Peter Palffy-Muhoray

We explore periodic structures of smectic-C (SmC) liquid crystals, induced optically by a polarization grating. The studied cells contain a passive surface of rubbed polyimide and an active photosensitive substrate of ate-dye doped polyimide. In a nematic phase the director field can be periodic independent of the angle between the grating vector and the rubbing direction. In the SmA phase periodic structure can be induced only by layer undulations. The SmC behaves similarly to the nematic phase, but the director can rotate only on a cone, which results in a more complex geometry. The periodic pattern is superimposed with four …