Demonstration of a 1/4 cycle phase shift in the radiation-induced oscillatory-magnetoresistance in GaAs/AlGaAs devices

We examine the phase and the period of the radiation-induced oscillatory-magnetoresistance in GaAs/AlGaAs devices utilizing in-situ magnetic field calibration by Electron Spin Resonance of DiPhenyl-Picryl-Hydrazal. The results confirm a $f$-independent 1/4 cycle phase shift with respect to the $hf = j\hbar\omega_{c}$ condition for $j \geq 1$, and they also suggest a small ($\approx$ 2%) reduction in the effective mass ratio, $m^{*}/m$, with respect to the standard value for GaAs/AlGaAs devices.Comment: 4 pages, 4 color figure

Radiation-induced magnetoresistance oscillations in two-dimensional electron systems under bichromatic irradiation

We analyze the magnetoresistance $R_{xx}$ oscillations in high-mobility two-dimensional electron systems induced by the combined driving of two radiation fields of frequency $\omega_1$ and $\omega_2$, based on the balance-equation approach to magnetotransport for high-carrier-density systems in Faraday geometry. It is shown that under bichromatic irradiation of $\omega_2\sim 1.5 \omega_1$, most of the characterstic peak-valley pairs in the curve of $R_{xx}$ versus magnetic field in the case of monochromatic irradiation of either $\omega_1$ or $\omega_2$ disappear, except the one around $\omega_1/\omega_c\sim 2$ or $\omega_2/\omega_c\sim 3$. $R_{xx}$ oscillations show up mainly as new peak-valley structures around other positions related to multiple photon processes of mixing frequencies $\omega_1+\omega_2$, $\omega_2-\omega_1$, etc. Many minima of these resistance peak-valley pairs can descend down to negative with enhancing radiation strength, indicating the possible bichromaticzero-resistance states.Comment: 5 pages, 3 figures. Accepted for publication in Phys. Rev.

Awareness of Information and Communication Technology (ICT) Tools Among Library Professionals in Tamil Nadu

The world is undergoing a transition from a paper economy to a digital economy. The need of the hour is a highly proactive role from the Third World countries either singly or jointly, that would take into account the changing scenarios in the information and communication technologies and their non-linear interactions and convergence. Developing countries are being encouraged to invest in their national information infrastructure so that they can participate in knowledge based development. Advances have brought many changes in libraries. An attempt has been made in this study to identify usage of Information Communication Tool among the library professionals in Tamil Nadu. Nearly 175 questionnaires were distributed among the library professionals in Tamil Nadu. Nearly 170 responses (97%) were received. It is found that all the respondents are using in one-way or the other various types of ICT Media tools

The effect of start-up delays in scheduling divisible loads on bus networks: An alternate approach

AbstractIn this paper, scheduling of divisible loads in a bus network is considered. The objective is to minimize the processing time by including the overhead component due to start-up time that could degrade the performance of the system, in addition to the inherent communication and computation delays. These overheads are considered to be constant additive factors to the communication and computation components. A closed-form expression for optimal processing time is derived. Using this closed-form expression, this paper analytically proves significant results regarding the optimal sequence of load distribution and optimal number of processors. Numerical examples are presented to illustrate the analysis

Radiopharmaceuticals Pattern of Development and Utilisation in India

The availability of research reactors at an early stage of our Atomic Energy Programme led to developmental efforts in the field of radiopharmaceuticals. Starting with temporary laboratories for this work, a sophisticated and dedicated Radiopharmaceutical Laboratory is now installed at Vashi in New Bombay. The use of several /sup 125/I-labelled compounds like Rose-Bengal, hippuran, etc. for imaging has been replaced over the years by /sup 99m/Tc compounds; the final formulations are prepared at the hospital using generators and cold kits supplied by the Board of Radioisotope Technology. Parallel with the development of short lived generators in radiopharmaceuticals came advances in imaging and instrumentation techniques, the scanners being replaced by sophisticated gamma cameras, with capabilities for tomography and computerisation. About 40 centres in India have the modern instrumentation and equipment needed for carrying out nuclear medicine procedures. Further growth of nuclear medicine centres in the country has, however, been limited by the need to import such advanced high cost instrumentation not currently available from indigenous sources. Regarding in-vitro radiopharmaceuticals, some RIA and IRMA kits and procedures have been developed. These include assay of T/sub 3/, T/sub 4/ and TSH in the thyroid group of hormones. Kits for several other important procedures are still being imported by some large medical centres. There are over a hundred and fifty medical laboratories carrying out RIA procedures

Association of Personality Traits among under Graduate students (With reference to Management stream)

This study was done to decide if there is a relationship between character attributes and graduation stream of understudies. This concentrate additionally tried the relationship of character characteristics with picked specialization. The large five-character attributes are estimated for an example of 106 administration understudies through a study created by the analyst. The chi-square outcomes showed relationship of extraversion, reliability, suitability and receptiveness with character attributes. Greater part of high scorers came from designing foundation while greater part of low scorers came from business foundation. Greatest quality contrasts were seen in designing understudies. Specialization decision was viewed as free of character