Oxide films of copper prepared by the oxidation of copper sulphide films

Copper sulphide films prepared by reactive evaporation, when heated in air at 500 K, oxidized to Cu₂O after a series of intermediate chemical transitions. Golden yellow coloured Cu₂O films showed a large absorption before the fundamental absorption edge. The optical band gap was found to be (2.29±0.02)eV. When these Cu₂O films were further heated they got converted to CuO and the optical band gap was found to be (2.17±0.02)eV.     

Single particle SU(3) parentage coefficients

The single particle SU(3) parentage coefficients are calculated for the case of leading SU(3) representation in the highest orbital symmetry partition, using the method suggested by Hecht. Tabulations are given for all possible cases of identical nucleons in η=3 and η=4 shells.     

Thermodynamics of textures in superfluid 3He

The contribution of the textures in the B-phase of superfluid ³He to the specific heat has been calculated. The specific heat is found to be divergent near T_c.     

Investigation of the role of NaBH<Subscript>4</Subscript> in the chemical synthesis of gold nanorods

An improvement in the previously reported seed-mediated chemical synthesis of gold nanorods (GNRs) is reported. Monodisperse GNRs have been synthesized in a one-step protocol. The addition of controlled quantity of sodium borohydride (NaBH₄) directly into the growth solution produced uniform GNRs, formed by in situ nucleation and growth. In order to arrive at the conclusion, we studied the formation of GNRs with various seeds, of metals of widely differing crystal structures, and there were no variations in the properties of the GNRs formed. The role of NaBH₄ in the growth of GNR, which has not been covered in previous reports, is discussed in detail. The dependence of longitudinal plasmon peak on the concentration of NaBH₄ is compared with the dependence of residual concentration of NaBH₄ in the seed solution, which is added to the growth solution in seed-mediated synthesis. The study shows that NaBH₄ plays an important role in the formation of GNRs. This proposed protocol offers a number of advantages: one-step preparation of GNRs, significant reduction in the preparation time to 10 min, high monodispersity of GNRs, and tailorability of the aspect ratio depending on NaBH₄ concentration. It is suggested that NaBH₄ added to the growth solution leads to in situ formation of the seed particles of the size of 3–5 nm which enables the growth of GNRs. The growth of GNRs suggested here is likely to have an impact on the preparation of other anisotropic structures. Our single-pot methodology makes the procedure directly adaptable for commercial-scale production of GNRs and for their synthesis even in undergraduate laboratories.     

Glass transition in biomolecules and the liquid-liquid critical point of water

Using molecular dynamics simulations, we investigate the relation between the dynamic transitions of biomolecules (lysozyme and DNA) and the dynamic and thermodynamic properties of hydration water. We find that the dynamic transition of the macromolecules, sometimes called a "protein glass transition," occurs at the temperature of dynamic crossover in the diffusivity of hydration water and also coincides with the maxima of the isobaric specific heat C_{P} and the temperature derivative of the orientational order parameter. We relate these findings to the hypothesis of a liquid-liquid critical point in water. Our simulations are consistent with the possibility that the protein glass transition results from crossing the Widom line, which is defined as the locus of correlation length maxima emanating from the hypothesized second critical point of water.     

Quasiadiabatic, nonfocusing transition-energy crossing

A quasiadiabatic nonfocusing transition-energy crossing is proposed for suppressing any nonadiabatic and undesired features in a longitudinally separated function-type accelerator, in which particles are confined by an radio-frequency voltage with an adiabatic reduction of the amplitude and accelerated by a step voltage. This new method has been examined, both theoretically and experimentally.     

Multiscale model for moisture transport with adsorption phenomenon in concrete materials

Abstract

We consider a new two-scale problem which is given as a mathematical model for moisture transport arising in a concrete carbonation process. In research for moisture transport, it is a crucial step how to describe the relationship between the relative humidity and the degree of saturation, mathematically. Here, we have proposed the two-scale model consisting of the diffusion equation for the relative humidity in a macro domain and the free boundary problems describing the relationship in infinitely micro domains. Accordingly, the structures of the micro domains are unknown in our model. This is a significant feature of our new model to emphasize. The aim of this paper is to establish local existence in time and uniqueness of a solution to the model.     

Vibrational Band Intensities of Hydrocarbons

Abstract

The experimental observables of a vibrational spectrum are depicted either in the form of their positions, i.e., frequency relating the energy required in a given quantum transition, or as the intensities of absorption and scattering related to their transition probabilities. Expressed in terms of molecular parameters, the frequencies depend on the geometry, atomic masses, and intramolecular forces [11 while the band intensities [2] reflect changes in dipole moment (infrared) or polarizabilities (Raman) which are caused during a vibrational displacement and are related to movement of electronic charges within the individual bonds. The mathematical basis for determining vibrational frequencies was well established as early as 1940 by Wilson [3] and others [4, 51. Applying the interpretation of vibrational spectra has become routine in the multitudinous disciplines of chemical literature [6–26]. Accounts of infrared and Raman spectra [27–29], collection of literature [30], and reasonable sets of intramolecular forces [31, 321 are now available for the prediction of normal frequencies of hydrocarbons.