3,933 research outputs found
Entanglement induced Sub-Planck structures
We study Wigner function of a system describing entanglement of two
cat-states. Quantum interferece arising due to entanglement is shown to produce
sub-Planck structures in the phase-space plots of the Wigner function. Origin
of these structures in our case depends on entanglement unlike those in Zurek
\cite{Zurek}. It is argued that the entangled cat-states are better suited for
carrying out precision measurements.Comment: 6 pages 2 figures (revised version include more quantitative
discussion
Spin-String Interaction in QCD Strings
I consider the question of the interaction between a QCD string and the spin
of a quark or an antiquark on whose worldline the string terminates. The
problem is analysed from the point of view of a string representation for the
expectation value of a Wilson loop for a spin-half particle. A string
representation of the super Wilson loop is obtained starting from an effective
string representation of a Wilson Loop. The action obtained in this manner is
invariant under a worldline supersymmetry and has a boundary term which
contains the spin-string interaction. For rectangular loops the spin-string
interaction vanishes and there is no spin-spin term in the resulting heavy
quark potential. On the other hand if an allowance is made for the finite
intrinsic thickness of the flux-tube, by assuming that the spin-string
interaction takes place not just at the boundary of the string world-sheet but
extends to a distance of the order of the intrinsic thickness of the flux tube,
then we do obtain a spin-spin interaction which falls as the fifth power of the
distance. Such a term was previously suggested by Kogut and Parisi in the
context of a flux-tube model of confinement.Comment: 19 pages, 1 figure; Published version with added discussion and
references in section
The Integration of Oxidative Surface Mapping and Molecular Dynamics Simulation Techniques as a Strategy for Studying Protein Conformational Change
The range and number of new and unknown proteins is increasing at a staggering rate due to the recent genome sequencing projects. The next step in understanding how biological systems, even including the human body, work is by understanding the function of all the various proteins. Solving the structure of a protein is an important first step in elucidating its function; however, the study of its dynamic movements can specifically implicate regions involved in its function and even demonstrate the mechanism by which function is performed.
Molecular dynamics simulations are a powerful computational approach for visualizing the dynamic movement of proteins. Computational tools are predominantly theory based predictions. Therefore, they require validation by experimental results. Oxidative surface mapping is an experimental labeling method which can be used to identify “buried” vs. “solvent-accessible” regions in a folded protein. Movement in specific regions of a protein can be mapped and monitored using this method.
β-lactoglobulin is a well studied protein that undergoes a pH induced conformational change. It was chosen as the target protein for this study because it has been the focus of numerous studies in the past and much information is known about it. Even so, many aspects of this protein’s structure still remain a mystery.
This thesis work is an attempt to integrate computational and experimental techniques as a strategy for studying the protein conformational change of a well studied protein system. The degree of overlap displayed by the integration of these two techniques is limited, however it provides a foundation from which improvements can be implemented for future attempts of studying protein systems using this approach
Thickness Dependent Structural, Magnetic and Transport Properties of of Cu / Co Thin Film and Multilayer Structures
Structural, magnetic and transport properties of electron beam evaporated Co/Cu thin film and multilayer structures (MLS) having different layer thicknesses have been characterized using XRD, MOKE and resistivity techniques. The structural studies show different crystal structures for different sub-layer thicknesses. The Co (300 Ǻ) single layer film is amorphous, while Cu (300 Ǻ) film is microcrystalline in nature. The particle size is found to decrease as the number of interfaces increase. The corresponding magnetic and resistivity measurements show an increase in saturation field and resistivity. However, coercivity decreases with decrease in particle size. The results conclude that these properties are greatly influenced by various micro structural parameters such as layer thickness, number of bilayers and the quality of interfaces formed under different growth conditions
Nature and occurence of yeasts in Haryana grapes and wines
More than one hundred isolates of yeasts were taken from juice, must (at different stages of fermentation) and wine prepared from seven different grape varieties grown in Haryana. The isolates fell into 6 genera and 14 species. Saccharomyces yeasts were the most frequently encountered species during the fermentation, and all but one were identified as S. cerevisiae, S. cerevisiae var. ellipsoideus, S. steineri, S. carlsbergensis and S. mellis. Schizosaccharomyces pombe, Debaryomyces vini, Candida pulcherrima, C. guilliermondii, Endomycopsis fibuliger, E. fibuliger var. monospora and E. fibuliger var. bispora were the other strains isolated.The occurrence of Schizosaccharomyces pombe and strains of Endomocopsis fibuliger is of interest in this connection when it is considered that Kloeckera apiculata and Saccharomyces oviformis have been significantly absent in Haryana grapes and musts
Free Response of Shells on Flexible Foundation
Free response of axisymmetric shells resting on flexible foundation in their asymmetric modes is studied using Finite Elements based on harmonic formulation. Influence of various parameters, such as subgrade modulus, proximity of boundary, density ratio, shear wave velocity, embedment of structure and depth of flexible foundation., on free response is studied. Axisymmetric interface element with harmonic functions is developed and introduced between the raft slab and foundation media
- …