Colour Confinement and Deformed Baryons in Quantum Chromodynamics

The confinement of coloured entities in Quantum Chromodynamics (QCD) is traced to colour singletness of the observed entities. This is believed to arise from colour singlet state of quark-antiquark for mesons and a fully colour antisymmetric state for baryons. This demands a spherically symmetric baryon in the ground state. However it is pointed out that a deformed baryon in the ground state has been found to be extremely successful phenomenology. There are convincing experimental supports for a deformed nucleon as well. This means that something has been missed in the fundamental theory. In this paper this problem is traced to a new colour singlet state for baryons which has been missed hitherto and incorporation of which provides a consistent justification of a deformed baryon in the ground state. Interestingly this new colour singlet state is global in nature.Comment: 5 pages, 1 figur

Temperatures, stresses and distortions in brake discs

This thesis records an investigation into the temperature distributions in brake discs resulting from different types of braking duties, and the stresses and deformations arising due to these temperature gradients. In particular, the 'bell' region of the brake disc, i.e. the heat-conducting path between the rubbing path and the mounting flange, is subjected to close analysis by both theoretical and experimental means. A knowledge of the temperature distributions in the bell is important, for two main reasons: to ensure that long periods of braking do not cause excessive temperatures at the mounting, and to enable thermal stresses and distortions to be evaluated. In this thesis e numerical method of solution based upon an idealisation of the disc is developed, and dynamometer tests ere described simulating vehicle braking for measurement of temperatures by means of thermocouples. The theoretical and experimental temperatures correlate well. [Continues.

Functional MRI using robotic MRI compatible devices for monitoring rehabilitation from chronic stroke in the molecular medicine era (Review)

The number of individuals suffering from stroke is increasing daily, and its consequences are a major contributor to invalidity in today’s society. Stroke rehabilitation is relatively new, having been hampered from the longstanding view that lost functions were not recoverable. Nowadays, robotic devices, which aid by stimulating brain plasticity, can assist in restoring movement compromised by stroke-induced pathological changes in the brain which can be monitored by MRI. Multiparametric magnetic resonance imaging (MRI) of stroke patients participating in a training program with a novel Magnetic Resonance Compatible Hand-Induced Robotic Device (MR_CHIROD) could yield a promising biomarker that, ultimately, will enhance our ability to advance hand motor recovery following chronic stroke. Using state-of-the art MRI in conjunction with MR_CHIROD-assisted therapy can provide novel biomarkers for stroke patient rehabilitation extracted by a meta-analysis of data. Successful completion of such studies may provide a ground breaking method for the future evaluation of stroke rehabilitation therapies. Their results will attest to the effectiveness of using MR-compatible hand devices with MRI to provide accurate monitoring during rehabilitative therapy. Furthermore, such results may identify biomarkers of brain plasticity that can be monitored during stroke patient rehabilitation. The potential benefit for chronic stroke patients is that rehabilitation may become possible for a longer period of time after stroke than previously thought, unveiling motor skill improvements possible even after six months due to retained brain plasticity

Seismic response of steel fibre reinforced concrete beam-column joints

The present research work aims to investigate numerically the behaviour of steel fibre reinforced concrete beam-column joints under seismic action. Both exterior and interior joint types were examined and 3D nonlinear finite element analyses were carried out using ABAQUS software. The joints were subjected to reversed-cyclic loading, combined with a constant axial force on the column representing gravity loads. The joints were initially calibrated using existing experimental data – to ascertain the validity of the numerical model used – and then parametric studies were carried out using different steel fibre ratios coupled with increased spacing of shear links. The aim was to assess the effect of introducing steel fibres into the concrete mix in order to compensate for a reduced amount of conventional transverse steel reinforcement and hence lessen congestion of the latter. This is particularly useful for joints designed to withstand seismic loading as code requirements (e.g. Eurocode 8) lead to a high amount of shear links provided to protect critical regions. The spacing between shear links was increased by 0%, 50% and 100%, whilst the fibre volume fraction (Vf) was increased by 0%, 1%, 1.5%, 2% and 2.5%. Potential enhancement to ductility, a key requirement in seismic design, was investigated as well as potential improvements to energy absorption and confinement. The work also examined key structural issues such as strength, storey drift, plastic hinges formation and cracking patterns