[en] A theoretical model for evaluating the photoelastic constants of ionic solids is developed by taking into account the long-range Coulombian, van der Waals and three-body interactions as well as the electronic polarizabilities of cations and anions. Hafemeister Flygare type short-range overlap repulsive potential effective upto nearest and next nearest neighbours is taken into account. The model is applied to calculate the photoelastic constants of ammonium halides with CsCl and NaCl type structures for the first time. The results obtained show a systematic trend in this group of solids. (author)

[en] The design of an aluminium foil-mylar preionized TEA nitrogen laser is described. The laser produces a high quality homogeneous beam that meets the stringent requirement of a Mach-Zehnder interferometer. Its subnano-second pulse width makes it suitable for the study of fast pulsed experiments. The applicability of the optical diagnostic system is demonstrated for a rapidly changing plasma in the plasma focus discharge. (author)

[en] The anharmonic properties of rubidium halides are investigated using a three-body interaction (TBI) potential. This includes the prediction of second-, third- and fourth-order elastic constants, the pressure dependence of second- and third-order elastic constants. The agreement between experimental and theoretical results is, generally, good. The inclusion of anharmonic terms in the potential might lead to further improvements. (author)

[en] The utilisation of low dose implant monitoring (using Boron) in a manufacturing line has been discussed. The utilisation of phosphorus ions as the second implant dose were also studied as comparison. The technique relies on the fact that the sheet resistant of doped layer will increase significantly when damaged by relatively low implant dose. The technique is very sensitive and applicable for adjusting the channel dose so that an accurate threshold voltage in MOS device could be achieved

[en] The most simple cases of studies in the magnetic properties like the diagonal and local environmental effects are studied for a simple and general model of cluster configuration having elements of binary alloys

[en] Magnetoconvective specific heat transfer coefficient has been measured in diamagnetic (Nsub2 O) and paramagnetic (Osub2) gases from a single platinum wire (diameter=0.025 mm) mounted along the axis of a Cu-cylinder (diameter=20.5mm). An enhancement in heat transfer coefficient is observed with an increase in magnetic field, the enhancement produced in Nsub2 O is found to be about 10 times smaller than Osub2. At higher field strength, a suppression in heat transfer coefficient is observed. The behaviour of heat transfer coefficient under the influence of electro-magnetic field is found to be similar to that observed in a magnetic field

[en] The Asymmetric Rotor Model (ARM) has been employed to describe the systematic features of energy levels, B(E2) values and B(E2) branching ratios of inter and intra band transitions of ¹⁰⁴Ru isotope. The present results are compared with known experimental values and other available theoretical models. A much better agreement has been achieved with experimental and other theoretical model results. This nucleus is assumed to be triaxial in shape. (author)

[en] Many water quality analysis simulation programs based upon various methodology and dimensions are presently available as tools in Water Resources Management. For example, depth-averaged two-dimensional models based upon the finite difference or finite element methods are routinely used. The unlumped finite element methods based upon the three-node linear, six-node quadratic or eight-node quadrilateral elements and other higher elements usually require considerable memory for execution, often beyond the capability of a 386 micro-computer. This paper presents a finite-element method based upon the three-node linear triangle with lumping to reduce memory requirements without losing stability nor accuracy. Application of this model to water quality simulations in Malaysia will be discussed

[en] Near infrared radiation tunable from 3.04 to 3.40 microns for sensing of natural gas is generated through difference frequency mixing of Nd laser and the same pumped dye laser radiations in the recently developed Beta Barium Borate crystal. Exploiting very high laser damage threshold of the crystal, the conversion efficiency at the generated near infrared radiation in the mixing process can be increased to a large extent simply by raising the peak power densities of the input dye and Nd lasers

[en] Using X-ray pinhole cameras and a crystal spectrograph, we have carefully measured and analysed the radiation composition and spatial distribution of plasmas produced by line-focused laser irradiation on segmented targets. The measured results show that intensities of different satellite lines and resonance lines of aluminium H-like ions are dependent on the laser intensity more strongly than that of He-like ions spectra. In addition, different from Al plasma, Au plasma only emits continuum and the spatial extent of gold LPX radiation remains almost unchanged in the whole range of LPX spectra, which makes the boundary of the spatial distribution of the LPX radiation field very sharp. (author)