Effect of Thermal Annealing on Boron Diffusion, Micro-structural, Electrical and Magnetic properties of Laser Ablated CoFeB Thin Films

We report on Boron diffusion and subsequent crystallization of Co$_{40}$Fe$_{40}$B$_{20}$ (CoFeB) thin films on SiO$_2$/Si(001) substrate using pulsed laser deposition. Secondary ion mass spectroscopy reveals Boron diffusion at the interface in both amorphous and crystalline phase of CoFeB. High-resolution transmission electron microscopy reveals a small fraction of nano-crystallites embedded in the amorphous matrix of CoFeB. However, annealing at 400$^\circ$C results in crystallization of CoFe with \textit{bcc} structure along (110) orientation. As-deposited films are non-metallic in nature with the coercivity (H$_c$) of 5Oe while the films annealed at 400$^\circ$C are metallic with a H$_c$ of 135Oe.Comment: 16 pages, 6 figure

Undrained Response and Liquefaction Behaviour of Non-Plastic Silty Sands Under Cyclic Loading

The undrained response and liquefaction behaviour of fine sand and silty sands consisting of 30% and 50% non-plastic fines were investigated in the present study. The effect of consolidation stress level, cyclic stress amplitude and amount of non-plastic fines on soil liquefaction have been studied through a systematically planned stress controlled cyclic triaxial tests. To examine the effect of consolidation pressure on liquefaction behaviour, the sand-silt specimens were prepared at 40% relative density and consolidated at pressures of 50, 100 and 200 kPa. To investigate the effect of fines content on liquefaction resistance of sands at constant postconsolidation void ratio, the sand-silt specimens were prepared at different relative densities of 20, 40 and 70%. The cyclic loading with CSR in the range of 0.075 to 0.275 was applied at a frequency of 1Hz in different tests. Test results show the influence of the addition of non-plastic fines to the sand on the reduction of liquefaction resistance. Soil specimens had exhibited higher resistance to liquefaction at low consolidation pressures and lower resistance at high consolidation pressures

A multicomponent model of the infrared emission from Comet Halley

A model based on a mixture of coated silicates and amorphous carbon grains produces a good spectral match to the available Halley data and is consistent with the compositional and morphological information derived from interplanetary dust particle studies and Halley flyby data. The dark appearance of comets may be due to carbonaceous coatings on the dominant (by mass) silicates. The lack of a 10 micrometer feature may be due to the presence of large silicate grains. The optical properties of pure materials apparently are not representative of cometary materials. The determination of the optical properties of additional silicates and carbonaceous materials would clearly be of use

ADAPTIVE BLIND NOISE SUPPRESSION

Volume 1 Issue 6 (August 2013

Foundation Problems in a Developing City

Foundation problems are normally associated with type of sub strata, soil, rock or any other foreign material\u27 met with, and/or if choice of foundation is not compatible with them. In developing cities, the development stress is on highly developed congested areas, limiting the sub soil investigation, and plans to have high rise buildings, requiring deep foundations and sometimes execution of these posing site problems. The collapse of a multi-storeyed structure caused, according to geotechnical engineers due to overlooking the existence of a drain and a few cases of composite foundations are described

Preparation, Characterization and In Vitro Drug Release Studies of 6-mercaptopurine Thin Film

Oral thin films of 6-mercaptopurine were fabricated from mucoadhesive polymer, chitosan and polyvinylpyrrolidone for the purpose of prolonging drug release and improving its bioavailability. All fabricated film formulations prepared were smooth and translucent, with good flexibility. The weight and thickness of all the formulations were found to be uniform. These films were also evaluated for surface pH, folding endurance, swelling percentage (% S) and in vitro disintegration time. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) were used to evaluate the physico-chemical nature of the films. In-vitro drug release have shown enhanced release profiles for thin films compared to pure drug and the release patterns have been found to be pH dependant. The results of the study reveals that fabrication of 6-MP oral thin film by using solvent cast technology is a simple and an efficient method for drug delivery to achieve desired therapeutic compliance.Keywords: 6-mercaptopurine; In Vitro Drug Release; SEM; FTI

Scaling of stiffness energy for 3d +/-J Ising spin glasses

Large numbers of ground states of 3d EA Ising spin glasses are calculated for sizes up to 10^3 using a combination of a genetic algorithm and Cluster-Exact Approximation. A detailed analysis shows that true ground states are obtained. The ground state stiffness (or domain wall) energy D is calculated. A D ~ L^t behavior with t=0.19(2) is found which strongly indicates that the 3d model has an equilibrium spin-glass-paramagnet transition for non-zero T_c.Comment: 4 pages, 4 figure

Effect of π Orbital on I/V Characteristics and Transmission in Molecular Diode Structures with Au Contacts

The electronic transport properties of electrons in a molecules are observed by using Non equilibrium Green’s function(NEGF). We present a extremely through and careful computational approach well ordered method to do a framework analysis of donor (CH3) and acceptor (CN) molecules connected between the Au(111) contacts, and also observed current progress through molecular devices depends on number of bonds or not. Such observations implementation through not possible by standard quantum chemistry soft wares. The results shows I-V characteristics, Transport spectrum and Transport analysis can effectively tune the molecules works like a conventional semi-conductor based diodes, these results invoke to design the logic gates and logic circuits

Pressure-induced amorphization and polyamorphism in one-dimensional single crystal TiO2 nanomaterials

The structural phase transitions of single crystal TiO2-B nanoribbons were investigated in-situ at high-pressure using the synchrotron X-ray diffraction and the Raman scattering. Our results have shown a pressure-induced amorphization (PIA) occurred in TiO2-B nanoribbons upon compression, resulting in a high density amorphous (HDA) form related to the baddeleyite structure. Upon decompression, the HDA form transforms to a low density amorphous (LDA) form while the samples still maintain their pristine nanoribbon shape. HRTEM imaging reveals that the LDA phase has an {\alpha}-PbO2 structure with short range order. We propose a homogeneous nucleation mechanism to explain the pressure-induced amorphous phase transitions in the TiO2-B nanoribbons. Our study demonstrates for the first time that PIA and polyamorphism occurred in the one-dimensional (1D) TiO2 nanomaterials and provides a new method for preparing 1D amorphous nanomaterials from crystalline nanomaterials.Comment: 4 figure