Effect of boundary scattering on spin-hall effect

The spin dependent reflection in quasi-two-dimensional electron gas from an impenetrable barrier in presence of Rashba and Dresselhaus spin-orbit coupling is analyzed in detail. It is shown that due to spin-orbit effects the reflected beam split in two beams gives rise to multiple reflection analogous to phenomena birefringence. The interplay between Rashba and Dresselhaus spin-orbit coupling gives rise to anisotropy in Fermi energy surface and a non-zero net spin-polarized current oscillating with two frequencies for all the values of incident angle except at $45^{o}$ when averaged over all components of reflected beam. It is also shown that in over critical region, all the three polarization components as well as net polarization has non-zero values and are exponentially decaying as distance from the barrier increases which in turns spin-accumulation near the barrier is an important consequence of spin-hall effect.Comment: 6 pages, 8 figure

IoT – A Pathway to Smart India – Part 4 (Housing & Transport)

In 4th Part of this exploratory paper, in continuation of Future Scope and Application of IoT Building Housing Applications, Transport Applications, Educational Applications & Law Enforcement Applications are explored in brief. Like previous part 3, some innovative IOT enabled devices also explored for reader’s info

A Semiparametric Bayesian Approach to a New Dynamic Zero-Inflated Model

We develop a dynamic zero-inflated model to analyse the number of hospital admissions within an aging population, which allows for the considerable number of zero hospital admissions at the individual level and occurrence dependence. In addition, certain health conditions may lead to groups of individuals having similar hospital admission rates. We analyse the US Health and Retirement Survey, which includes selfassessed health (SAH), which can be predictive of hospital admissions. Our modelling framework embeds a dynamic hierarchical matrix stick-breaking process to flexibly characterize this dynamic group structure allowing individuals to belong to different SAH groups at different points in time

Comparison between the two models of dephasing in mesoscopic systems

In mesoscopic systems to study the role of inelastic scattering on the phase coherent motion of electrons two phenomenological models have been proposed. In the first one, due to B\"uttiker, one adds a voltage probe into the system (or in the scattering matrix). The second model invokes the complex (or optical) potential in the system Hamiltonian. Studying a simple geometry of a metallic loop in the presence of Aharonov-Bohm magnetic flux, we show that the two probe conductance is symmetric in the reversal of the magnetic field in B\"uttiker's approach. Whereas the two probe conductance within the complex potential model is asymmetric in the magnetic flux reversal contrary to the expected behavior.Comment: 11 pages RevTex, 4 figures inculded, Communicated to PR

Antimoth finishing treatment for woollens using tannin containing natural dyes

Attempts have been made to develop natural dye based antimoth finishing process using natural dyes as an alternative of  chemical based process. Natural dyes obtained from different sources are used to dye the woollen fabric and then screened for antimoth efficacy. Woollen fabrics dyed with extract of silver oak leaves, wall nut husk and pomegranate rind have shown highest resistance to moth attack. The screened sources carrying antimoth property are then subjected to phytochemical analysis along with non-carrying natural dyes for analyzing their chemical constituents. The result reveals that the chemical constituent of natural dyes plays a crucial role in determining antimoth efficacy. The amount of tannin content present in the natural dyes can be taken as an indicator to determine the antimoth efficacy

Applying dissipative dynamical systems to pseudorandom number generation: Equidistribution property and statistical independence of bits at distances up to logarithm of mesh size

The behavior of a family of dissipative dynamical systems representing transformations of two-dimensional torus is studied on a discrete lattice and compared with that of conservative hyperbolic automorphisms of the torus. Applying dissipative dynamical systems to generation of pseudorandom numbers is shown to be advantageous and equidistribution of probabilities for the sequences of bits can be achieved. A new algorithm for generating uniform pseudorandom numbers is proposed. The theory of the generator, which includes proofs of periodic properties and of statistical independence of bits at distances up to logarithm of mesh size, is presented. Extensive statistical testing using available test packages demonstrates excellent results, while the speed of the generator is comparable to other modern generators.Comment: 6 pages, 3 figures, 3 table

Aharonov-Bohm oscillations and spin transport in a mesoscopic ring with a magnetic impurity

We present a detailed analysis of the Aharonov-Bohm (AB) interference oscillations manifested through transmission of an electron in a mesoscopic ring with a magnetic impurity atom inserted in one of its arms. The spin polarization transport is also studied. The electron interacts with the impurity through the exchange interaction leading to exchange spin-flip scattering. Transmission in the spin-flipped and spin-unflipped channels are explicitly calculated. We show that the entanglement between electron and spin-flipper states lead to a reduction of AB oscillations in spite of absence of any inelastic scattering. The spin-conductance (related to spin-polarized transmission coefficient) is asymmetric in the flux reversal as opposed to the two probe conductance which is symmetric under flux reversal. We point out certain limitations of this model in regard to the general notion of dephasing in quantum mechanics.Comment: 6 pages RevTeX, 9 eps figures included, enlarged version of cond-mat/000741

Efficacy of natural dye from Gerardiana diversifolia on pashmina (Cashmere) shawls

The present investigation deals with studies on potentiality of a colour extract from Gerardiana diversifolia as a source of natural dye, and on identification of chemical constituents responsible for dyeing ability. The efficacy of the extracted dye(s) on pashmina (Cashmere) fabrics has been evaluated for colour strength and fastness properties. Phytochemical studies reveal that the quinone and tannin are major components contributing to dyeing properties. The extracted colorant from Gerardiana diversifolia has potential to dye pashmina fabric with brown and grey shades having excellent wash and good to very good light fastness properties

RF Controlled Robotic Vehicle with Metal Detection Project

The project is intended to cultivate a robotic vehicle that can sense metals ahead of it on its path similar to detecting land mines. The robot is controlled by a remote using RF technology. It consists of a metal detector circuit interfaced to the control unit that alarms the user behind it about a doubted land mine ahead. An 8051 series of microcontroller is used for the preferred operation. For controlling the movement of robot either to forward, backward & right or left commands are sent to the receiver by using push buttons of the transmitter. At the receiving end two motors are interfaced to the microcontroller where they are used for the movement of the vehicle. The RF transmitter acts as a RF remote control that has the advantage of sufficient range (up to 200 meters) with proper antenna, while the receiver decodes before serving it to another microcontroller to drive DC motors via motor driver IC for necessary work. A metal detector circuit is attached on the robot body and its operation is carried out automatically on sensing any metal underneath. The instant the robot senses this metal it produces an alarm sound through buzzer. This is to aware the operator of a probable metal (eg: land mine) ahead on its path. Further the project can be enhanced by mounting a wireless camera on the robot so that the operator can govern the movement of the robot remotely by observing it on a screen