Differential rotation enhanced dissipation of tides in the PSR J0045-7319 Binary

Recent observations of PSR J0045-7319, a radio pulsar in a close eccentric orbit with a massive B-star companion, indicate that the system's orbital period is decreasing on a timescale of $\approx 5 \times10^{5}$ years, which is much shorter than the timescale of $\approx$ 10^9 years given by the standard theory of tidal dissipation in radiative stars. Observations also provide strong evidence that the B-star is rotating rapidly, perhaps at nearly its break up speed. We show that the dissipation of the dynamical tide in a star rotating in the same direction as the orbital motion of its companion (prograde rotation) with a speed greater than the orbital angular speed of the star at periastron results in an increase in the orbital period of the binary system with time. Thus, since the observed time derivative of the orbital period is large and negative, the B-star in the PSR J0045-7319 binary must have retrograde rotation if tidal effects are to account for the orbital decay. We also show that the time scale for the synchronization of the B-star's spin with the orbital angular speed of the star at periastron is comparable to the orbital evolution time. From the work of Goldreich and Nicholson (1989) we therefore expect that the B-star should be rotating differentially, with the outer layers rotating more slowly than the interior. We show that the dissipation of the dynamical tide in such a differentially rotating B-star is enhanced by almost three orders of magnitude leading to an orbital evolution time for the PSR J0045-7319 Binary that is consistent with the observations.Comment: 8 pages, tex. Submitted to Ap

Compact Design of Strip line Edge-coupled Band Pass Filter for Q-Band

Volume 2 Issue 8 (August 2014

An Extreme Learning Machine-Relevance Feedback Framework for Enhancing the Accuracy of a Hybrid Image Retrieval System

The process of searching, indexing and retrieving images from a massive database is a challenging task and the solution to these problems is an efficient image retrieval system. In this paper, a unique hybrid Content-based image retrieval system is proposed where different attributes of an image like texture, color and shape are extracted by using Gray level co-occurrence matrix (GLCM), color moment and various region props procedure respectively. A hybrid feature matrix or vector (HFV) is formed by an integration of feature vectors belonging to three individual visual attributes. This HFV is given as an input to an Extreme learning machine (ELM) classifier which is based on a solitary hidden layer of neurons and also is a type of feed-forward neural system. ELM performs efficient class prediction of the query image based on the pre-trained data. Lastly, to capture the high level human semantic information, Relevance feedback (RF) is utilized to retrain or reformulate the training of ELM. The advantage of the proposed system is that a combination of an ELM-RF framework leads to an evolution of a modified learning and intelligent classification system. To measure the efficiency of the proposed system, various parameters like Precision, Recall and Accuracy are evaluated. Average precision of 93.05%, 81.03%, 75.8% and 90.14% is obtained respectively on Corel-1K, Corel-5K, Corel-10K and GHIM-10 benchmark datasets. The experimental analysis portrays that the implemented technique outmatches many state-of-the-art related approaches depicting varied hybrid CBIR system

An Economic Assessment along the Jatropha-based Biodiesel Value Chain In India

The Government of India had launched the National Biofuel Mission in the year 2003 as an initiative to limit the country’s dependence on crude oil imports. An integral part of this mission is the Biodiesel Blending program and Jatropha, a tree-borne biodiesel yielding crop, is the cornerstone of the program. This study has been specifically designed to carry out economic assessment of the upcoming jatropha-based biodiesel value chain in the country. The study, based on primary data collected from three major jatropha growing states, has observed that jatropha cultivation is an economically viable proposition in the long-run as indicated by favourable values of net present value, internal rate of return and benefit cost ratio. Nevertheless, initial government support till attaining break even point is crucial to sustain the interest of the farmers. The jatropha seed processing industry has been found to be viable if operated at sufficient economies of scale, which in turn is determined by the level of backward integration with the seed market and a forward integration with biodiesel distribution channels. However, the existing biodiesel value chain in India lacks this integration and is characterized by under-developed seed markets, sub-optimal processing infrastructure and ill-defined biodiesel distribution channels. The involvement of corporate players to participate in processing and distribution activities has further delayed the program to take off. The study has cautioned that unless proactive orientation of all the stakeholders is ensured, the program may fail to meet its objectives, at least in the medium-term.Agricultural and Food Policy,

Analysis of Steel Made Leaf Spring using FEA Tool ANSYS

Mathematical and computer modelling have been playing an increasingly important role in the Computer Aided Engineering (CAE) process of many products in the last 60 years. Simulation offers great advantages in the development and analysis phase of products and offers a faster, better and more cost effective way than using physical prototypes alone. This paper analyses the mechanics characteristic of a composite leaf spring made from glass fibre reinforced plastics using the ANSYS software. Considering interleaf contact, the stress distribution and deformation are obtained. Taking the single spring as an example, comparison between the performance of the GFRP and the steel spring is presented. The comparison results show that the composite spring has lower stresses and much lower weight. Then the automotive dead weight is reduced observably