Volume 3 Issue 1
Authors: Fayez Mahamoud El-Hossary; Sayed Mohammed Khalil; Magdy Abdel Wahab Kassem; Medhat Abed EL Lateef; Khaled Lotfy
Abstract: Nickel titanium (NiTi) alloys are potentially useful in biomedical applications due to their unique superelasticity behaviour and shape memory effects (SME). However, these alloys are vulnerable to surface corrosion and the most serious issue is out-diffusion of toxic Ni ions from the substrate into body tissues and fluids. Hence, it is necessary to produce a surface barrier to impede the out-diffusion of Ni ions from the alloys. The inductively coupled radio frequency plasma (ICRFP) is an efficient technique for modifying the surfaces of NiTi alloys. The results exhibit the enhancement of the corrosion resistance and tribological properties of the NiTi substrate, but also effectively suppress the Ni ions release from the substrate. All these improvements can be attributed to the formation of titanium nitride (TiN) on the surface of NiTi alloys.
Keywords: Nickel Titanium (NiTi); Superelasticity; Shape Memory Effect SME; Inductively Coupled Radio Frequency Plasma (ICRFP); Corrosion Resistance; Fraction Coefficient
Authors: Naohisa Fukase; Yasuyuki Miura; Shigeyoshi Watanabe
Abstract: The sharing method is proposed that a memory is shared between plural physical link by using the multi-port memory in wormhole router for NoC (Network on Chip) as efficient usage of the flit buffers. If the proposed method is implemented by conventional method, hardware costs will increase greatly. Therefore, sharing a memory by block size is put forward. This paper presents the outline and pipeline processing of the proposed method. The pipeline of the proposed method has two courses of the routes 1 and 2. The number of pipeline stages of route 2 is 2 stages larger than the traditional router in order to use a shared memory. But delay is concealed if the capacity of a private buffer is enough. In addition, the effectivity of proposed method is shown by simple estimation of hardware cost and evaluation result of communication performance by software simulation.
Keywords: Router; Interconnection-Network; Network on Chip; Multi-Port Memory
Authors: Anjan Kumar Chowdhury
Abstract: The minisuperspace Wheeler-De Witt equation is solved exactly for some suitable parameters. A slightly modified Wheeler-De Witt equation has been considered to examine the effect of higher order field variables on the potential function, through which an exact solution with suitable parameters is found. From the solution, it is seen that the universe expands or contracts exponentially. Other physical significance of the solution is also discussed.
Keywords: Quantum cosmology; Wheeler-De Witt equation; Minisuperspace; Exact solution
Authors: Chhandak Mukherjee; C. K. Maiti
Abstract: In this work, we investigate the self-heating effects on n-p-n Si heterojunction bipolar transistors (HBTs) with SiGe base and AlGaAs/GaAs HBTs with graded GaAs base via Technology CAD (TCAD) simulation study. Using fully coupled energy balance coupled with thermionic emission transport, two-dimensional numerical process and device simulations have been performed. It is observed that both the self-heating and local temperature increase due to higher internal device power dissipation. Dependence of direct current (DC), alternating current (AC) and self-heating effects on alloy composition of SiGe in the base region are investigated. It is shown that the self heating in SiGe HBTs is high (compared to identical Si BJTs) and significant electrical performance degradation takes place in SiGe HBTs.
Keywords: HBT; SiGe; GaAs; AlGaAs; TCAD; Self-Heating; Energy Balance; Device Simulation; Process Simulation
Authors: Weimin Huang
Abstract: Based on the concept of Angular Momentum Geometric Space Configuration, this article discusses the sudden formation of the storms such as Typhoon, Tornado and Sandstorm, as well as their tremendous energy. The Boltzmann entropy for angular momentum of “gas of vortices” is calculated based on the ideal gas model in continuum mechanics using statistical method of non-localized particles in local region. It is shown that the formation of concentrative vortex is the spontaneous process of Boltzmann entropy decrease. The generalized thermal potential energy T<sub>G,A</sub>S<sub>B,A</sub> corresponding to the angular momentum geometric space configuration is used to reveal the excess energy in vortex formation. It is the result of the Boltzmann entropy decreasing for process withΔT<sub>G,A</sub>S<sub>B,A</sub>=0.
Keywords: Concentrative Vortex; Gas Of Vortices; Boltzmann Entropy; Angular Momentum Geometric Space Configuration (AMGSC); Thermal Potential Energy; Entropy Elastic Force
Authors: Kal Renganathan Sharma
Abstract: Damped wave conduction and relaxation equation is solved in three dimensions in order to gauge the ampacity risks in PCB interconnections. V = u/r substitution is used and the temperature profile is obtained in three dimensions and in one dimension. In the creeping transfer limit, the spatio-temporal profile is given as a modified Bessel composite function in space and time of the third order. Three regimes of solution are identified; (i) lag regime; (ii) rising regime given by Bessel composite function in space and time and; (iii) rising regime given by modified Bessel composite function in space and time. In the general case, the order of the solution is found to be 7/2 and the order of the solution is two in the case of one dimension.
Keywords: Damped Wave Conduction and Relaxation; Relativistic Transformation; Bessel Composite Function of Third Order; Ampacity Risks; Second Law of Thermodynamics
Authors: Bhawna Pandey; H. M. Agrawal
Abstract: The excitation functions of (n,p), (n,) and (n,2n) reactions for stable isotopes of bromine are calculated using EMPIRE-3.0 β1 and TALYS-1.2 codes from threshold to 20 MeV within the framework of Hauser- Feshbach statistical model with pre-equilibrium effects. Recently, parity dependent nuclear level density (NLD) option has been incorporated in both codes. In the present work, the newly incorporated NLD option has been adopted for the calculations of the excitation functions for stable bromine isotopes. A reasonably good agreement between the calculated and experimental data validates the parity dependent NLD option in both codes.
Keywords: Excitation Function; Pre-Equilibrium Model; Compound Nucleus Model; Cross-Sections; Parity Dependent Nuclear Level Density
Authors: Nardeen Tharwat Messiha; Atef M. Ghuniem; H. M. EL-Hennawy
Abstract: A new particle is introduced called complementary omega structure (COS). Transmission characteristics of omega and omega-like structures and their complementary structures have been numerically studied. Several numerical simulations are also performed and presented in order to conceive the interaction between these particles with the applied electromagnetic (EM) fields. All simulation results obtained confirm that the omega/omega-like structure and its complement are dual.
Keywords: Complementary Omega Structure (COS); Complementary Omega-like Structure (COLS); Duality; Omega Structure; Omega-Like Structure
Authors: Partha Roy Chaudhuri; Sudip Chatterjee
Abstract: The properties of guided light in linearly-graded refractive index profile planar optical waveguides with multilayered structure are studied in view of their unique characteristics. Towards exact analysis, we perform mode-calculation of the given waveguide structures using a formulation with Airy functions devised with the exponential ones as solutions to Helmholtz’s equation. First, we confirm the efficacy of our analysis by applying appropriate solution schemes to a few known waveguides having such linearly-graded index profiles that are studied and reported in the literature with quoted results. Then we visit the field confinement properties of such multilayered waveguides that are sensitive to various structural parameters. We demonstrate the progressive field penetration in low-index core region and single-mode operation at high core-depth as useful properties with unique advantages. These characteristics are particularly relevant in accessing guided field, in sensing and in controlling modal propagation in guided wave devices. The study should be useful to design and explore new devices for applications in integrated optics.
Keywords: Linearly Graded Index Waveguide; Mode Effective Index; Mode Field Distribution; Multilayered Waveguide; Confinement Factor