Effect of ion temperature on propagation of ion-acoustic solitary waves of small amplitudes in collisionless plasma

By using a perturbation technique, the Korteweg-de Vries equation is derived for a mixture of warm-ion fluid and hot, isothermal electrons. Stationary solutions are obtained for this equation and are compared with the corresponding solutions for a mixture consisting of cold-ion fluid and hot, isothermal electrons.

ESR study of metal ion-guanosine monophosphate interaction

The addition of guanosine 5-monophosphate (5′-GMP) to an aqueous solution of Mn2+ ions results in a decrease in ESR signal intensity and an increase in line-width of Mn2+ ions. This can be interpreted in terms of stepwise formation of outersphere and inner-sphere complexes as When Mg2+ is added to a mixture of Mn2+ and 5′-GMP, ESR signal intensity increases, presumably due to the replacement of Mn2+ by Mg2+ in the complex. From the variation of ESR signal intensity as a function of concentration of Mg2+, the product K1K2 for the magnesium complex i s calculated as 125 M−1. This difference in stability constants may indicate that both phosphate group and guanine base are involved in the formation of Mn2+-5′-GMP complex.

Sulphate ion dynamics in a-alums studied by esr at high pressures

The variation of zero-field splitting and linewidth of Cr3+ ion in KCr and KAI alums with hydrostatic pressure and with temperature is investigated. A model for the apparent phase transition is proposed on the basis of the reorientational motion of the SO2-4 groups.

Influence of Sm2O3 doping on formation and structure of SrBi2Nb2O9 nanocrystals in lithium borate glasses

New glasses of 16.66SrO–16.66[(1 − x)Bi2O3–xSm2O3]–16.66Nb2O5–50Li2B4O7 (0 ≤ x ≤ 0.5, in molar ratio), i.e., the pseudo-binary Sm2O3-doped SrBi2Nb2O9–Li2B4O7 glass system, giving the crystallization of Sm3+-doped SrBi2Nb2O9 nanocrystals are developed. It is found that the thermal stability of the glasses against the crystallization and the optical band gap energy increases with increasing Sm2O3 content. The formation of fluorite-type Sm3+-doped SrBi2Nb2O9 nanocrystals (diameters: 13–37 nm) with a cubic structure is confirmed in the crystallized (530 °C, 3 h) samples from X-ray powder diffraction analyses, Raman scattering spectrum measurements, and transmission electron microscope observations. The effect of Sm3+-doping on the microstructure, Raman scattering peak positions, and dielectric properties of composites comprising of fluorite-type SrBi2Nb2O9 nanocrystals and the Li2B4O7 glassy phase is clarified. It is found that fluorite-type SrBi2Nb2O9 nanocrystals transform to stable perovskite-type SrBi2Nb2O9 crystals with an orthorhombic structure by heat treatments at around 630 °C.

Role of magnesium ion on the interaction between chromomycin A3 and deoxyribonucleic acid

Abstract is not available.

Proton magnetic resonance study of piezoelectric lithium formate monohydrate

Abstract is not available.

A proton magnetic resonance study of lithium acetate dihydrate, Li(CH3COO).2H20

Abstract is not available.

Synthesis of Azo Coupled Crown Ethers Containing Transition Metal and other Chromophoric Environments and Their Ion Complexation Properties

The crown ethers, 2,3-benzo-1,4,7,10,13-pentaoxa-cyclopentadeca-2-ene and 2,3, ll,12-dibenzo-l,4,7,10,13,16-hexaoxscyclooctadeca-2,11-diene are incorporated into H,N'-ethylenebis(acetylacetoneimino) nickel(II) and copper(II), phenol, and β-naphthol by diazo coupling reactions. The selective nature of the coupling reaction has-been demonstrated by the isolation of both asymmetric mono- and symmetric bis(glyoxalarylcrownhydrazoneimino) metal(II) complexes. An interesting binuclear complex containing two intramolecularly rearranged (glyoxal-hydrazonearylimino) metal(II) groups joined by 18-crown-6 result8 when bis(arenediazonium)-18-crown-6 is coupled with the metal(I1) Schiff bases. The substituted ethers form cationic salts with NaClO4, KCNS, NH4CNS, 14g(CNS)2 and Ca(CNS)2. All the synthesised ethers exhibit ion selectivity sequence as K+ > Na+ and Ca2+ > Mg2+.

Reactive state selectivity in photodimerization through micellar counter-ion effects: photodimerization of acenaphthylenes

Photodimerization of acenaphthylene and 5,6-dichloroacenaphthylene solubilized in sodium dodecylsulphate (SDS), cetyltrimethylammonium chloride (CTAC), dodecyltrimethylammonium chloride (DTAC), cetyltrimethylammonium bromide (CTAB) and Triton X-100 micelles gives a mixture of cis and trans dimers. The magnitude of the cis:trans ratio is sensitive to the type of micelle used. In CTAB micelles the heavy atom effect of the bromide counter-ions leads to an increased triplet-derived trans dimer yield, whereas in micelles with light atom counter-ions (CTAC, DTAC and SDS) the singlet-derived cis dimer predominates.

Propagation of ion-acoustic waves in a multi-component plasma

The authors derive the Korteweg-de Vries equation in a multicomponent plasma that includes any number of positive and negative ions. The solitary wave solutions are also found explicitly for the case of isothermal and non-isothermal electrons.

Electron paramagnetic resonance study of vanadyl ion in K2Zn(SO4)2·6H2O and K2Mg(SO4)2·6H2O

EPR study of the vanadyl ion has been carried out in its paramagnetically dilute form in K2Zn(SO4)2·6H2O and K2Mg(SO4)2·6H2O at room temperature at X-band. The vanadyl ion enters the divalent metal site and preferentially orients itself in the direction of the water molecules forming the octahedron and forms the vanadyl sulfate pentahydrate complex. The g and A tensorscorresponding to the two populous V-O orientations have been analyzed to obtain the principal values and their direction cosines with respect to the crystallographics axes. It is found that the g and A tensor have the same principal frames of reference within the limits of eperimental error. A correlation between the metal-water distance and the populations of the different V-O orientations is observed.

Influence of Lithium Fluoride on the Burning Rate of AP-Polyester Propellant

THE addition of catalysts normally serves the purpose of imparting a desired burning rate change in a composite propellant. These may either retard or enhance the burning rate. Some often quoted catalysts are oxides, chromites and chromates of metals. A lot of work has been done on rinding the effect of the addition of some of these catalysts on the burning rate; however, none seems to have appeared on the influence of lithium fluoride (LiF). Only qualitative reduction in the burning rate of composite propellants with the addition of LiF was reported by Williams et al.1 Dickinson and Jackson2 reported a slight decrease in the specific impulse of composite propellant with the addition of LiF; however, they made no mention of the effect of its addition on the burning rate. We have studied the effect of the addition of varying amounts of LiF on the burning rate of Ammonium Perchlorate (AP)-Polyester propellant.

Nonlinear saturation of ion-acoustic instability

It is proposed that the wave mediated indirect wave-particle interaction may be responsible for nonlinear saturation of current driven low frequency ion-acoustic turbulence. This process decreases the growth rate and increases the damping rate of the wave. Comparison has been made with some experiments.

Effect of ionic temperature on propagation of ion-acoustic solitary waves in a collisionless plasma of warm-ion fluid and non-isothermal electrons

Using a perturbation technique, we derive Modified Korteweg—de Vries (MKdV) equations for a mixture of warm-ion fluid (γ i = 3) and hot and non-isothermal electrons (γ e> 1), (i) when deviations from isothermality are finite, and (ii) when deviations from isothermality are small. We obtain stationary solutions for these equations, and compare them with the corresponding solutions for a mixture of warm-ion fluid (γ i = 3) and hot, isothermal electrons (γ i = 1).

Ferroelectricity in lithium potassium sulphate

. Measurement of the relation between polarisation P and electric field E for lithium potassium sulphate (LiKSO4) was made in the low temperature range below room temperature. The P-E hysteresis loops along the c axis of LiKSO4 were observed in the low-temperature phase below the lower transition point Ttl of about -70 degrees C, and in the intermediate phase below the upper transition point Ttu of about -25 degrees C. These phases were found to be ferroelectric. The temperature dependence of the spontaneous polarisation Ps and the electric coercive field Ec were obtained.