etd AT Indian Institute of Science: Recent submissions
Now showing items 181-200 of 8174
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Excitation dynamics in GaAs quantum wells
The dynamics of excitons is studied using time?resolved photoluminescence. We deduce experimentally, for the first time, the intrinsic homogeneous linewidth of free excitons in GaAs quantum wells. The scattering rate of ... -
Nonexponential decay of sound in rooms
(i) The above analysis of decay of sound in rectangular rooms under various boundary conditions shows that the overall decay is in general non?exponential because the normal modes corresponding to different angles of ... -
Studies on the role of spatial coherena in the lau phenomenon
The Laue effect is of fundamental importance in the domain of optical interference phenomena. In the Laue experiment, interference fringes are formed in the far field when an extended source illuminates two gratings placed ... -
Relative efficiencies of devanagari and tamil scripts for reading
This thesis is devoted primarily to some of the problems involved in reading with particular emphasis on Devanagari and Tamil scripts. Scripts are considered as codes and their performance examined on the basis of information ... -
Studies on drop formation at conical and capillary tips
Despite the role of drops being recognised in many metallurgical processes, surprisingly no significant progress has been made in this area. An understanding of the drop formation phenomenon is expected to give a better ... -
Electron spectroscopic studies of surface segregation and oxidation of Cu and Ni based alloys and low temperature preparation and characterization of intermetallics base on the system Fe-W-Mo
An overview of the surface studies on alloys reported in the literature and the objectives of the present investigationbave been presented in this chapter. Preparation and characterization of the various alloys studied ... -
Physical and mathematical modelling of boron carbide manufacturing process
Boron carbide is produced in a heat?resistance furnace using boric oxide and petroleum coke as the raw materials. In this process, a large current is passed through the graphite rod located at the center of the cylindrical ... -
Corrosion and related electrochemical studies on ziroconium (in nitrate melts, nitrats fluoride melts and aqueous nitrate solutions)
The thesis embodies the results of the investigations on the corrosion of zirconium in nitrate melts. The predicted thermodynamic behaviour of zirconium in 2-component NaNO?-KNO? eutectic melts based on E-pO diagrams ... -
Thermodynamic studies on the systems Ln-Fe-O (Ln = Nd, Sm, Dy)
Ternary oxides in the systems Ln–Fe–O (Ln = Nd, Sm, Dy) have been prepared by the citrate–nitrate route and characterised by X?ray diffraction analysis. The particle sizes of the ternary compounds were estimated to be in ... -
Knowledge-based mining of multi-database for associations
Knowledge Discovery in Databases (KDD) uses knowledge engineering tools and database technology to extract hidden patterns from databases. Data mining is a step in the KDD process that finds useful patterns in the data. ... -
Design and perfomance evaluation of bus access schemes for salan-an experimental local area network
Local Area Networks (LANs) spanning a limited geographic area have emerged of late as a field of wide applicability. One of the prime factors governing the design of a LAN is the Medium Access Control (MAC) scheme which ... -
Combinatorial algorithms for determinant based problems
The thesis started with the early history and development of the theory of determinants. All the important results up to the 1880s were presented through a computing perspective. Pfaffians are closely related to determinants; ... -
Stokes polarimetry and the measurement of vector magnetic fields in solar active regions.
The aim of this thesis has been measurement of Stokes profiles and vector magnetic fields in sunspots using the Kodaikanal Tower/Tunnel Telescope and spectrograph. Although this coelostat telescope had been constructed ... -
Application of finite graph models of context fue languages.
A finite graph model for a context?free language is proposed. The model is called an extended transition system; its nodes encode [pushdown automata state, top stack symbol] pairs and its arcs encode pushdown automaton ... -
Insights into the formulation of PU foam and its mechanical behavior under quasi-static and impact loads
In today’s world, cellular materials find extensive use in many engineering applications including being deployed as energy?absorbing countermeasures for impact safety protection. Polymeric foam is a popular category of ... -
Studies on simple and restricted orifice surgre tanks
This thesis deals with certain basic experimental studies conducted on the phenomenon of mass oscillations in restricted orifice surge tanks. Simple surge tanks were also studied, they being considered an extreme case of ... -
Some characteristics of branch channel flow
This thesis comprises three parts. The first part contains literature survey, the second part the theoretical analysis, experimental verification and results, and the third part the development of a precision point gauge. ...