4,413 research outputs found
Aharonov-Bohm Radiation of Fermions
We analyze Aharonov-Bohm radiation of charged fermions from oscillating
solenoids and cosmic strings. We find that the angular pattern of the radiation
has features that differ significantly from that for bosons. For example,
fermionic radiation in the lowest harmonic is approximately isotropically
distributed around an oscillating solenoid, whereas for bosons the radiation is
dipolar. We also investigate the spin polarization of the emitted
fermion-antifermion pair. Fermionic radiation from kinks and cusps on cosmic
strings is shown to depend linearly on the ultraviolet cut-off, suggesting
strong emission at an energy scale comparable to the string energy scale.Comment: 14 pages, 6 figures. Version 2: Expanded discussion on boundary
conditions obeyed by Dirac equation mode functions (in Section V B).
Acknowledgements and references added. Version 3: Minor changes made in
response to referee's comment
Beneficiation and Processing of some Important Raw Materials, for Iron and Steel Production
India is committed to a policy of industrialisation
and, along with others, the mineral industries are
also expanding. The iron and still industry in the
country can be considered to be fairly well est-
ablished and with the expansion of the existing
plants and the erection of three new plants, the
steel ingot production is expected to go up to six
million tons by the end of the Second plan period.
Four ferro-manganese plants in the country viz.
i) The Tata Iron and Steel Company's plant at joda
ii) Jeypore Mining Syndicate's at Raygada (Orissa},
iii) Ferro Alloys Corporation at Garividi (Andhra)
and (iv)Electro Metallurgical works Private Ltd., at Dandeli (Bombay) have gone into production and five
more plants are expected to be established shortly to increase the production to 1,60,000 tons, of which 1
lakh will be for export and the remainder for internal consumption
Discourses Of Prejudice In The professions: The Case Of Sign Languages
There is no evidence that learning a natural human language is cognitively harmful to children. To the contrary, multilingualism has been argued to be beneficial to all. Nevertheless, many professionals advise the parents of deaf children that their children should not learn a sign language during their early years, despite strong evidence across many research disciplines that sign languages are natural human languages. Their recommendations are based on a combination of misperceptions about (1) the difficulty of learning a sign language, (2) the effects of bilingualism, and particularly bimodalism, (3) the bona fide status of languages that lack a written form, (4) the effects of a sign language on acquiring literacy, (5) the ability of technologies to address the needs of deaf children and (6) the effects that use of a sign language will have on family cohesion. We expose these misperceptions as based in prejudice and urge institutions involved in educating professionals concerned with the healthcare, raising and educating of deaf children to include appropriate information about first language acquisition and the importance of a sign language for deaf children. We further urge such professionals to advise the parents of deaf children properly, which means to strongly advise the introduction of a sign language as soon as hearing loss is detected
Benefication, sintering and processing of raw materials for the iron and steel industry
Beneficiation of iron ores relates not only to enrichment of the metal content but also to improvements in physical characteristics of the ore charged into the blast-furnace. The latter is achieved by crushing, sizing and agglo-meration of resultant fines etc. It is universally reco-ginzed that preparation of sized iron-ore burden and use of fluxed sinter in iron production can achieve (i) redu-ction in coke rate by reducing the metallurgical load on the blast-furnace by better utilization of available heat and (ii) increased productivity
Sintering of Iron Ore Fines, and Raw Materials for Bhilai Steel Plant
A detailed study has been made at the National Metall-urgical Laboratory on the sintering charactersitics of the iron-ores of Rajharapahar. Madhya Pradesh, and other raw materials likely to be used in the Bhilai steel plant. The effects of variables such as coke and moisture contents in sinter mix, basicity and raw material proportions, on the sintering time and their effects on the quality of sinter
produced, have been studied with a sintering plant desig-ned and fabricated at the Laboratory. Optimum conditions for producing the best sinter have been determined. Results of the tests on the Bhilai sample show that coke has a pronounced effect on sinter properties whereas moisture content directly affects permeability and sint-ering rate. 6.1% by weight of coke was found to be the optimum quantity for producing a good sinter. The optimum water content in the charge for producing the most per-meable bed was 7%. The basicity for producing a good self-fluxing sinter in the shortest time was 0.
Fuselage shell and cavity response measurements on a DC-9 test section
A series of fuselage shell and cavity response measurements conducted on a DC-9 aircraft test section are described. The objectives of these measurements were to define the shell and cavity model characteristics of the fuselage, understand the structural-acoustic coupling characteristics of the fuselage, and measure the response of the fuselage to different types of acoustic and vibration excitation. The fuselage was excited with several combinations of acoustic and mechanical sources using interior and exterior loudspeakers and shakers, and the response to these inputs was measured with arrays of microphones and accelerometers. The data were analyzed to generate spatial plots of the shell acceleration and cabin acoustic pressure field, and corresponding acceleration and pressure wavenumber maps. Analysis and interpretation of the spatial plots and wavenumber maps provided the required information on modal characteristics, structural-acoustic coupling, and fuselage response
Beneficiation of Kyanite and Sillimanite
KYANITE and sillimanite have the same chemical compo-sition AI2O3. Si02 and are used extensively in the ref-ractory brick manufacture.Kyanite sillimanite having a minimum 60% AI2O3 and less than 1% of iron oxide prefe-rably in the form of 1/2" lumps are required by the refractory industry. Low grade sillimanites from Bihar,
Maharastra, Karnataka and Orissa were tested in
NML for either upgrading or lowering the iron oxide
content of the samples. Depending upon the liberation
size, kyanite is usually upgraded by gravity methods when the lighter siliceous gangue comprising quartz and mica are removed. When the gravity methods fail, flota-tion is employed. Iron oxides are eliminated by either reduction roast followed by magnetic separation or acid leaching
Modular differential equations for characters of RCFT
We discuss methods, based on the theory of vector-valued modular forms, to
determine all modular differential equations satisfied by the conformal
characters of RCFT; these modular equations are related to the null vector
relations of the operator algebra. Besides describing effective algorithmic
procedures, we illustrate our methods on an explicit example.Comment: 13 page
A new look at nonparasitized red cells of malaria-infected monkeys
Many reports have shown that malarial parasites can produce distinct morphological and molecular alterations in the membranes of the parasitized erythrocytes, but few studies have been carried out on nonparasitized erythrocytes of infected animals. We report here that the outer leaflet of the membrane bilayer of nonparasitized erythrocytes contains significantly larger amounts of aminophospholipids (phos-phatidylethanolamine (PE) and phosphatidylserine (PS)), than the normal red cell membrane. This alteration in nonparasitized red cells is probably caused by Ca2+-induced cross-linking of spectrin, and gradually disappears after chloroquine treatment. The external localization of PS in these cells together with defective structure of their cytoskeletal network provide a strong basis for the complications associated with malaria infection like thrombosis, infarction and severe anaemia
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