Extensional wave motion in homogenous isotropic thermoelastic plate by using asymptotic method

The present investigation is concerned with the study of extensional wave motion in an infinite homogenous isotropic, thermoelastic plate by using asymptotic method. The governing equation for the extensional wave motions have been derived from the system of three-dimensional dynamical equations of linear coupled theory of thermoelasticity. All coefficients of the differential operator are expressed as explicit functions of the material parameters. The velocity dispersion equation for the extensional wave motion is deduced from the three-dimensional analog of Rayleigh–Lamb frequency equation for thermoelastic plate waves. The approximations for long and short waves and expression for group velocity are also derived. The thermoelastic Rayleigh–Lamb frequency equations for the considered plate are expanded in power series in order to obtain polynomial frequency and velocity dispersion relations whose equivalence is established to that of asymptotic method. The dispersion curves for phase velocity and attenuation coefficient are shown graphically for extensional wave motion of the plates.     

A novel single source precursor: [bis(N,N-diethyl-N'-naphthoyl-selenoureato)palladium(II)] for palladium selenide thin films and nanoparticles

We describe for the first time the use of a single source precursor to deposit thin films and nanocrystals of palladium selenide.     

On mock theta functions and weight-attached Frobenius partitions

The Ramanujan Journal - In this paper, we provide the combinatorial interpretations of many mock theta functions and some generalizations using Frobenius partitions with attached weights. We...     

Kinetics and mechanism of gas‐phase pyrolysis of N‐aryl‐3‐oxobutanamide ketoanilides,their 2‐arylhydrazono derivatives,and related compounds

Rates and products of reaction and Arrhenius activation parameters were determined for the gas‐phase thermolysis of 14 substrates of the title compounds using sealed pyrex reactor tubes and HPLC/UV‐VIS to monitor substrate pyrolysis. The 14 compounds under study are N‐phenyl‐3‐oxo‐ ( 1 ), N‐(p‐chlorophenyl)‐3‐oxo‐ ( 2 ), N‐(p‐methylphenyl)‐3‐oxo‐ ( 3 ), and N‐(p‐methoxyphenyl)‐3‐oxobutanamide ( 4 ), in addition to (i) four substrates ( 5–8 ) obtained by the replacement of the pairs of methylene hydrogens at the 2‐position of compounds ( 1–4 ), each pair by a phenylhydrazono group; (ii) three arylhydrazono derivatives ( 9–11 ) in which Cl, CH₃, or OCH₃ groups are substituted at the para position of the phenylhydrazono moiety of compound 5 ; (iii) 3‐oxobutanamide (acetoacetamide, 12 ), N‐phenyl‐3‐oxo‐3‐phenylpropanamide ( 13 ), and N,N′‐diphenylpropanediamide ( 14 ). The reactions were conducted over 374–546 K temperature range, and the values of the Arrhenius log A(s^?1) and E_a(kJ mol^?1) of these reactions were, respectively, 12.0 ± 2.0 and 119.2 ± 17.0 for the ketoanilides ( 1–4, 12–14 ), and 13.0 ± 0.7 and 157.5 ± 8.6 for the arylhyrazono compounds ( 5–11 ). Kinetically, the arylhydrazono derivatives were found to be ca. 1.4 × 10³ to 5.7 × 10³ times less reactive than the parent ketoanilides. A mechanism is proposed to account for reaction products and to rationalize molecular reactivities. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 39: 82–91, 2007     

Nucleon currents between highly excited nuclei: (II). Influence of the relative motion

A finite-temperature Thomas-Fermi method has been used to study the nucleon flux between two hot semi-infinite slabs of nuclear matter in arbitrary relative motion. As an application, we estimate the imaginary part of the optical potential associated with nucléon transfer at the strong absorption radius. Analytical fits to the exact results are given for head-on and tangential collisions at zero temperature.     

Effect of Pr-Ca substitution on the transport and magnetic behavior of LaMnO3 perovskite

The effect of simultaneous substitution of a fluctuating cation and a divalent cation in LaMnO₃ perovskite modifies the properties of the material to exhibit large valence colossal magnetoresistance (CMR) effect. A good example of these properties is (La_1−2x Pr _x Ca _x )MnO₃ (LPCMO) type CMR material. In this communication it is reported that, with the increase in x (for x=0.1, 0.15, 0.2), the T _c varies between 100 and 120 K with improvisation in metal-insulator transition. Interestingly, resistance increases with x from few hundred ohms to few kilo ohms with corresponding decrease in the unit cell volume. The results of the studies using X-ray diffraction (XRD), electrical resistivity, magnetoresistance and ac susceptibility measurements on LPCMO samples for understanding the structural, transport and magnetic properties are discussed in detail.     

KLL Auger and x-ray photoelectron spectra of phosphine,some phosphorus halides and the other hydrides isoelectronic with argon

KL₂L₃(¹D₂) Auger and 1s photoelectron energies have been measured for molecular hydrides isoelectronic with Argon (HCl, H₂S, PH₃ and SiH₄). In addition a detailed comparison of Auger and photoelectron shifts in a series of phosphorus halides (vs phosphine) has been undertaken using additional P_2p binding energies. The potential model is better able to predict 1s binding energy shifts with either ground state or relaxation corrected models than the 2p shifts. These latter values seem also to be reduced by shielding effects. In general, fluorides are better predicted than chlorides. Auger shifts correlate linearly(but not in a 1:1 relationship) with 1s photoelectron shifts throughout the isoelectronic series and also in the case of the phosphorus fluorides and phosphine. The two potential models, however, provide poor prediction of Auger shifts.