Division of Physical and Mathematical Sciences: Recent submissions
Now showing items 341-360 of 901
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Studies on Single and Two Stage Stirling Type Pulse Tube Coolers of Low and Medium Capacities including Performance Enhancement of Pressure Wave GeneratoI and a Novel Helium Recondensation System
Cryocoolers are mechanical devices that produce cold at temperatures below -150oC. Work required to produce the cold is supplied by a Pressure Wave Generator (PWG). This thesis is concerned with the development and analysis ... -
Probing the Nature of Dark Matter in the Universe
The dark matter is the most dominating matter candidate and a key driving force for the structure formation in the universe. Despite decade-long searches, the precise nature and particle properties of dark matter are ... -
Study of Photo-generated Charge Transport in Graphene-based Hybrid Structures
Hybrid structures involving atomic/molecular membranes from two or more layered materials are emerging as a platform for novel class of field effect transistors (FETs), p - n junctions, photo-detectors, photo-voltaic ... -
Optical, Structural and Mechanical Characterization of Ultrafast Laser Inscribed Chalcogenide Waveguides
In recent years, chalcogenide glasses have established their usefulness as attractive candidates for the fabrication of all-optical devices and mid infra-red lasers. These glasses possess low phonon energy and hence high ... -
AGN Feedback in Galaxy Clisters - Controlling Cooling Flows in Galaxy Clusters by Momentum-driven AGN Jets
Synopsis According to the hierarchical structure formation model, massive structures like galaxy clusters are formed due to the gravitational collapse of initial density perturbations and their subsequent mergers. ... -
Iridates, Black Phosphorus, Weyl and Dirac Semimetals Under Extreme Conditions : Raman Study
This thesis presents Raman studies of Sodium iridates (Na2IrO3 and Na4Ir3O8), VO2, black phosphorus, Weyl (TaAs, TaP, NbP and NbAs) and Dirac (Cd3As2) semimetals under ex-treme conditions like low temperature (upto 4K), ... -
Non-invasive Elastic Property Recovery of Tissue and Tissue-Like Objects from Ultrasound Excited Resonant Modes
This thesis is on non-invasive elastic property measurement of tissue or tissue-mimicking materials through vibro-acoustography and ultrasound assisted diffusing wave spectroscopy (UA-DWS). Towards this, a known force is ... -
Deterministic Two Stage Clonal Expansion Model of Breast Cancer Epidemiology and its Utility for Optimal Screening Policies in India
Breast cancer (BC) has emerged as public health issue in India in last two decades sur-passing cervix cancer. Mortality from breast cancer is 30-40% higher than maternal causes. Breast cancer 5 year survival rates are ... -
Topological Insulators and Transition Metal Dichalcogenides Under Extreme Conditions : Optical Studies
This thesis presents experimental as well as theoretical studies of three dimensional topological in-sulators (TIs) and transition metal dichalcogenides (TMDs). Raman spectroscopic measurements of these systems have been ... -
Excursions in ill condensed quantum matter from amorphous topological insulators to fractional spins
Condensed matter physics is a fascinating subject where collective properties of many particle systems show exotic emergent phenomena, practically unpredictable from the behavior of individual constituents. Many basic ... -
Ultrafast Photoexcited Carrier Dynamics in Low Dimensional Systems Probed by Time Resolved Terahertz Spectroscopy
The key aspect of this thesis is to understand the photoinduced carrier dynamics in low dimensional systems by employing time resolved optical pump-terahertz probe (OPTP) spectroscopy. Ultrafast pulsed laser (Ti: Sapphire ... -
Aspects of time dependence in quantum quenches
In this thesis we study the time dependence of correlators such as Green function, entanglement (Renyi) entropy and mutual information following quantum quench in Conformal Field Theories (CFTs) and their holographic duals ... -
Edge States and Effects of Disorder in Finite Graphene Sheets
The thesis endeavours to theoretically understand electronic properties of nite trapezoidal shaped graphene sheets, and understand zero energy edge states. The motivation for this thesis is recent experimental work at Low ... -
Multiple Stable States and Abrupt Transitions in Spatial Ecosystems
Ecosystems can exhibit multiple stable states at similar external conditions. Such systems shift from one stable state to another abruptly and discontinuously, when they cross certain threshold parameters. Some examples ... -
Magnetic, Electrical and Structural Properties of Doped Manganite, Ferrite and Nickelate Perovskites
Multifunctional materials with novel magnetic and electric properties have attracted intense research interest due to prospects in technological applications as well as understanding of fundamental physics. Perovskite ... -
Optoelectronic Properties of Graphene Based Van-der-Waals Hybrids
Light matter interactions in atomically thin van der Waals materials have attracted significant attention in recent day [1–6]. Although the thickness does not exceed few nano-meters, such an atomically thin materials alone ... -
Nonlinear Charge Transport and Photo-Physical Studies in Conjugated Polymers (P3meT, P3HT) and their Hybrid Composites with Silver Sulfide Quantum Dots
Organic semiconductors have been investigated as an emerging class of materials for their viable applications in electronics. Despite considerable improvement in device properties, a better understanding of the nature of ... -
Fully Solution Processed Flash Memory
The field of advanced solution processed spin-coated electronics has rapidly expanded over the last few decades towards the development of low-cost, large area and low power consumer electronics for the design of ... -
Solid State NMR- Development of Methods and Applications to the Study of Materials
In this chapter the application of solid state NMR techniques for the investigation of biodegradable polymers which have wide range of applications in various fields have been presented. Among many polymer systems poly ... -
Dilation Theory of Contractions and Nevanlinna-Pick Interpolation Problem
In this article, we give two different proofs of the existence of the minimal isometric dilation of a single contraction. Then using the existence of a unitary dilation of a contraction, we prove the `von Neumann's ...