Feasibility of using high temperature superconducting magnets and conventional magnetic loop antennas to attract or repel objects at the space station

A study was undertaken to see if magnetic forces can be used at the Space Station to attract or repel spacecrafts such as the Orbital Manuevering Vehicle (OMV) or the Orbiter. A large magnet, in the form of a current loop, is assumed to be placed at the Space Station and another one on the spacecraft. The expression for the force between the two dipoles (loops) is obtained. Using a force of 15 Newtons (3.4 pounds) in order to move the spacecraft, the number of ampere-turn needed in the current loops was calculated at various distances between them. The expression for the force of attraction between a current loop and a soft magnetic material was also examined and the number of amp-turn needed to provide a force of one-tenth of a pound at various distances is also calculated. This one tenth of a pound force would be used in a life line system for the retrieval of an adrift crewman or tool at the Space Station. The feasibility of using conventional antenna on the Station and the incoming vehicle for attraction or repulsion was also examined

Investigating texture six zero lepton mass matrices

Texture six zero Fritzsch like as well as non Fritzsch like hermitian lepton mass matrices (144 combinations in all) have been investigated for both Majorana and Dirac neutrinos for their compatibility with the current neutrino oscillation data, keeping in mind the hierarchy of neutrino masses. All the combinations considered here for Majorana neutrino masses are ruled out by the existing data in the case of inverted hierarchy and degenerate scenario. For Majorana neutrinos with normal hierarchy, only 16 combinations can accommodate the experimental data. Assuming neutrinos to be Dirac particles, normal hierarchy, inverted hierarchy as well as degenerate neutrinos are ruled out for all combinations of texture 6 zero hermitian mass matrices.Comment: 14 pages, 2 figure

Automatic antenna switching design for Extra Vehicular Activity (EVA) communication system

An Extra Vehicular Activity (EVA) crewmember had two-way communications with the space station in the Ku-band frequency (12 to 18 GHz). The maximum range of the EVA communications link with the space station is approximately one kilometer for nominal values for transmitter power, antenna gains, and receiver noise figure. The EVA Communications System, that will continue to function regardless of the astronaut's position and orientation, requires an antenna system that has full spherical coverage. Three or more antennas that can be flush mounted on the astronaut's space suit (EMU) and/or his propulsive backpack (MMU), will be needed to provide the desired coverage. As the astronaut moves in the space station, the signal received by a given EVA antenna changes. An automatic antenna switching system is needed that will switch the communication system to the antenna with the largest signal strength. A design for automatic antenna switching is presented and discussed

Production of Silicomanganese Alloy from Low Manganese Containing Leached Sea Nodules Residue

Leached sea nodules residue was used for the present study for exploring its utilization. The residue generated in ammoniacal-SO2 pressure leaching was water washed to reduce the sulphur content. To improve the Mn/Fe ratio in the residue, it was blended with Fe-Mn slag or Mn ore in the calculated amount and smelting was carried out in 50 kVA submerged arc furnace. Various parameters such as holding time, amount of reductant, power input etc. were investigated. The maximum recovery of Mn from residue blended with Fe-Mn slag and Mn ore was 58% and 65% respectively in the form of silicomanganese

The Large-Scale, Authentic Assessment of Listening and Speaking as Interactive Communication: Issues in Reliability

In this article we discuss reliability issues in the large-scale assessment of speech communication through authentic or performance techniques used recently in Saskatchewan. New performance-based approaches enable educators to evaluate the integrated, interpersonal communication skills of large populations of students, thereby modeling best professional practice. We conclude, however, that decentralized teacher rating approaches do not yet demonstrate sufficient reliability to enable public officials to use the results for high-stakes testing purposes.Dans cet article, nous discutons de questions de fiabilité dans réévaluation à grande échelle de la communication verbale par le biais de techniques authentiques (ou basées sur la performance) employées en Saskatchewan. De nouvelles approches reposant sur la performance permettent aux enseignants d'évaluer les compétences communicatives intégrées et interpersonnelles de grandes populations d'élèves, reflétant ainsi les meilleures stratégies pédagogiques. Nous concluons toutefois que les approches impliquant une évaluation décentralisée ne s'avèrent pas encore suffisamment fiables pour que les fonctionnaires se servent des résultats dans des contextes ou l'enjeu est considérable

Effect of gibberellin on seeded Vitis vinifera with special reference to induction of seedlessness

Application of GA (25-50 ppm) to Ana:b-e-Shahi at prebloom stage decreased the bunch weight and berry number but weight of the berries was increased and up to 29.6% seedless berries were induced. GA sprays (25-50 ppm) at 2-3 days after full lbloom increased the bunch and berry weights but few seedless berries were induced.GA application (50-150 ppm) to Bhokri grape at 10-11 days before full bloom formed more than 90% seedless berries but bunch weights and berry number were reduced. WitJh an additional second spray at 7- 8 days after full bloom, berry size was impmved but bunch weights were still reduced. At 4-5 days before full bloom application of GA, up to 41.4 % seedless berries were induced but bunch and berry weights were a,gain reduced. With another spray at postbloom stage bunch and berry weights were brought to the level of control.   In Gros Colman (Pusa) grape, GA application (50-100 ppm) at 5-6 days before full bloom and 2-3 days after full bloom also formed seedless berries but the bunch and berry weights were reduced. IFruit set was also improvP.d at boVh stages of spray. Prebloom GA application (50-150 ppm) to Alamwick grape, produced seedless berries up to 38.29% but ,bunch and berry weights were appreciably decreased. No effect on berry number was noticed.Application of GA (25-75 ppm) at prebloom + posbbloom and postbloom alone decreased the bunch and berry weights and berry number markedly of Bharat Early and Black Hamburg varieties. Toxic effects like shot berry formation and cracking of rachis were noticed. No seedless berries were observed. however, more berries with 1 or 2 seeds were formed at the expense of berries with 3 or 4 seeds. Even GA application at Jow concentrations to these varieties (5-25 ppm) reduced bunch weights and berry number.The differential response of these seeded varieties of Vitis vinifera is attributed to different amounts of growth factors and inhibitors present in them

Lead sorption by sea nodule residue generated in reduction roasting – ammonia leaching.

Residue generated in reduction roast – ammonia leaching of sea nodules has been utilised for the remediation of aqueous lead. Characterization of sea nodule residue (SNR) reveals fine granulometry (d50 = 11.4 µm) and high surface area of 66.7 m2 g-1. Batch adsorption experiments have been performed varying different parameters. Equilibrium experimental data fitted well in the Langmuir isotherm and derived maximum adsorption capacity (qm) of lead onto SNR has been found to be 840.34 mg Pb(II)/g SNR at 303 K. The qm enhanced to very high value of 2500 mgPb/gSNR upon raising the temperature to 323 K. The pseudo second-order model has been found applicable to the lead removal kinetics