On equilibration and coarsening in the quantum O(N) model at infinite NN

The quantum O(N) model in the infinite $N$ limit is a paradigm for symmetry-breaking. Qualitatively, its phase diagram is an excellent guide to the equilibrium physics for more realistic values of $N$ in varying spatial dimensions ($d>1$). Here we investigate the physics of this model out of equilibrium, specifically its response to global quenches starting in the disordered phase. If the model were to exhibit equilibration, the late time state could be inferred from the finite temperature phase diagram. In the infinite $N$ limit, we show that not only does the model not lead to equilibration on account of an infinite number of conserved quantities, it also does \emph{not} relax to a generalized Gibbs ensemble consistent with these conserved quantities. Nevertheless, we \emph{still} find that the late time states following quenches bear strong signatures of the equilibrium phase diagram. Notably, we find that the model exhibits coarsening to a non-equilibrium critical state only in dimensions $d>2$, that is, if the equilibrium phase diagram contains an ordered phase at non-zero temperatures.Comment: 11 pages, 9 figure

Unstructured Object Recognition using Morphological Learning

A technique of object recognition which can detect absence or presence of objects of interest without making explicit use of their underlying geometric structure is deemed suitable for many practical applications. In this work, a method of recognising unstructured objects has been presented, wherein several gray patterns are input as examples to a morphological rule-based learning algorithm. The output of the algorithm are the corresponding gray structuring elements capable of recognising patterns in query images. The learning is carried out offline before recognition of the queries. The technique has been tested to identify fuel pellet surface imperfections. Robustness wrt intensity, orientation, and shape variations of the query patterns is built into the method. Moreover, simplicity of the recognition process leading to reduced computational time makes the method attractive to solve many practical problems

Evolution of microstructure and phases in in-situ processed Ti-TiB composites containing high volume fractions of TiB whiskers

Journal ArticleA series of titanium composites, with varying volume fractions of titanium monoboride (TiB) whiskers, were made by mixing various proportions of titanium (Ti) and titanium diboride (TiB2) powders followed by hot pressing. The phases present were identified by x-ray diffraction

A Study of Cognitive Functioning in Aging

INTRODUCTION: Cognitive functioning in individuals changes with aging. The extent and pattern of decline varies among various cognitive do mainsand also among individuals. Certain cognitive domains tend to decline as a person ages in comparison to his younger counterpart. Some elderly individuals may not show a decline in cognitive functioning. High intelligence, well organized work habits and sound judgment compensate for many of the progressive shortcomings of old age. Cognitive decline is thought to start after the age of 30 years. Little that is new and original is learned after the age of forty. A ttention, language, and memory are the basic processes that serve as building blocks for the development of higher intellectual functions. The higher cognitive functions include manipulation of well learned material, abstract thinking, problem solving, judgment, arithmetic computations. These complex functions are predicated on the integrity and interaction of more basic processes. Because they represent the most advanced stages of intellectual development, the higher cognitive functions are more susceptible to neurological diseases. The evaluation of these higher functions may demonstrate the early effects of cortical damage before the more basic processes of attention, language and memory are affected. AIM OF STUDY 1.To study the pattern of decline of various cognitive functioning with aging. 2. To compare with healthy controls in the community. 3. To identify the differences in cognitive status based on the educational level and IQ of the patient. MATERIALS AND METHODS: STUDY CENTRE: Department of Geriatric Medicine, Madras Medical College & Rajiv Gandhi General Hospital Chennai. STUDY DESIGN: Case control study. SAMPLE SIZE: One hundred and twenty six: seventy six cases above the age of 65 and 50 controls from 20-30 age group. STUDY DURATION: December 2011 –November 2012. SELECTION OF PARTICIPANTS: INCLUSION CRITERIA: 1. Patients above 65 yrs of age attending the geriatric outpatient department. 2. Healthy controls between 20 and 30 years of age from the community. EXCLUSION CRITERIA: 1. Acutely toxic patients. 2. Patients with diabetes, hypertension, stroke and primary neurologic disease like alzhemier’s. CONCLUSION: Cognitive changes show a positive correlation with both aging and educational status. Verbal fluency shows a decline with age ,but shows a stronger association to the level of education. Higher the level of education, better performance on verbal fluency . Recent memory, episodic memory, Executive functions, Visuospatial skills, and psychomotor functions also decline as age advances. Performance on tests of executive functions, visuospatial skills, verbal fluency show a positive correlation to the level of education. Performance on tests of Recent memory, episodic memory and psychomotor function a decline with aging irrespective of the educational status