Deformations of Cosmological Solutions of D=11 Supergravity

We study Lunin-Maldacena deformations of cosmological backgrounds of D=11 supergravity which gives an easy way to generate solutions with nonzero 4-form flux starting from solutions of pure Einstein equations which possess at least three U(1) isometries. We illustrate this on the vacuum S-brane solution from which the usual SM2-brane solution is obtained. Applying the method again, one either gets the recently found S-brane system where contribution of the Chern-Simons term to field equations is non-zero or the SM2-SM2(0) intersection, depending on which U(1) directions are used during the process. Repeated usage of the procedure gives rise to configurations with several overlapping S-branes some of which are new. We also employ this method to construct two more new solutions and make comments about accelerating cosmologies that follow from such deformed solutions after compactification to (1+3)-dimensions.Comment: v2:some comments and references adde

Research Output Analysis of Top Six Universities of Tamil Nadu, India : A Scientometric View

Scientometrics is an important field of information science as it represents a unique set of techniques and tools for the monitoring and analysis of information resources and for the management of knowledge in social and organizational contexts. This article analysed the various Scientometric components of the articles published by top six universities of Tamil Nadu from 2000-2017. The study identifies research trend, characteristics growth and collaboration pattern of published literature. The analysis of data reveals that the average growth rate increases at the rate of 9.76%. Further, the average citation per paper observed is 12.18%. High degree of international collaboration is notified and USA and South Korea are found to be the most preferred collaborative countries. The CAGR calculated for six universities are 9.76. The major research publications outputs are from the field of Chemistry, Crystallography and Pharmacy

Research Output Analysis of Top Six Universities of Tamil Nadu, India : A Scientometric View

Scientometrics is an important field of information science as it represents a unique set of techniques and tools for the monitoring and analysis of information resources and for the management of knowledge in social and organizational contexts. This article analysed the various Scientometric components of the articles published by top six universities of Tamil Nadu from 2000-2017. The study identifies research trend, characteristics growth and collaboration pattern of published literature. The analysis of data reveals that the average growth rate increases at the rate of 9.76%. Further, the average citation per paper observed is 12.18%. High degree of international collaboration is notified and USA and South Korea are found to be the most preferred collaborative countries. The CAGR calculated for six universities are 9.76. The major research publications outputs are from the field of Chemistry, Crystallography and Pharmacy

The design, implementation and evaluation of a web-based learning environment for distance education

In this study, the need was emphasised to investigate the effects of using the Web in teaching students at a distance using a multi-level evaluation framework. A Web-based learning environment was designed, developed, implemented and evaluated for this purpose. Constructivist epistemology provided the basis for developing various components and developing problem-centred and interactive activities. Management, tutorial, interaction and support components were designed to work with each other to construct the learning environment, deliver course content, facilitate interaction and monitor student progress.A methodology was designed to describe and assess the learning environment in terms of access (standardisation, speed, resources, the tutor and peers), costs (types, structure, factors influencing, etc.), teaching and learning functions (quality of course objectives, materials and resources, learning approach and student achievement), interactivity (quantity and quality of student-tutor and student-peer interaction), user-friendliness (user-interface design, ease of use and navigation design) and organisational issues. The learners were Egyptian first-grade secondary school students (32), assigned randomly, and the topic selected for the course being developed was mathematics. Feedback was obtained from both learners and experts in distance education and on-line learning during the developmental and field-testing of the learning environment. Quantitative and qualitative methods (on-line student and expert questionnaires, students' logs, performance in formative evaluation, content analysis of peer discussions, achievement test and cost-analysis) were combined to gain insights into students' satisfaction with the different instructional and technical features and capabilities of the learning environment, achievement of course objectives in comparison with conventional classroom students, factors influencing their learning and perceptions and the unit cost per student study hour.The results indicated that although the learning environment and course materials were accessible, interactive, well-structured, user-friendly and achievement was successful for the on-line group, no significant differences were identified between the on-line students and traditional classroom students in overall achievement or achievement of low-order and high-order learning objectives. In addition, it is unlikely any cost saving would be made from shifting to the Internet to deliver instruction and many major factors were found to influence the development and support costs of on-line learning

Do Citations make Impact on Social Media? : An Altmetric Analysis of Top Cited Articles of University of Madras, South India

Altmetrics is an emergent research area whereby social media is applied as a source of metrics to assess scholarly impact. Over the most recent couple of years, the enthusiasm for altmetrics has developed, offering ascend to numerous inquiries in regards to their potential advantages and difficulties. As another developing field, Altmetrics has turned into a trailblazer, and got a decent arrangement of consideration by specialists associated with the assessment of logical research. This paper aims to analyse top 15 articles of University of Madras which have scored high citations. It aims to find out to what extend the top cited articles have secured altmetric scores. Do the citation score really create any impact on the social media? This is the research question formulated and comparing tool features, social media data sources, and social media events provided by Altmetric aggregators and thus they are analysed. Spearman Rank correlation metrics shows high correlation between the ranks of citations and Altmetric scores. The tweeter and Mendeley are the media through the scholarly communication highly disseminate. The analysis of readers shows that United States tops the list, followed by United Kingdom and Spain and are mainly educational ones with Ph.D, Post Graduate and Masters. The Practitioners are observed to be the voracious readers of the social media resulting in the present altmetric analysis

Testing of Lotka’s law and its Suitability to research productivity of Annamalai University, A Higher Education Institution, South India

Lotka’s Law describes the frequency of publications by authors in a given subject/discipline. In the present study, an attempt has been made to study the suitability of the Lotka’s Law to the publications of a Higher Educational institution of a region consisting of academic authors and researchers in various disciplines. Annamalai University has been ranked 20th in the state level and 56th at National level by MHRD. Annamalai University is renowned for its research output performance and has been funded for many major, minor and DST research projects. It has a large network and linkages to academia, R&D organisations and industries. It covers almost all the subjects with 10 Faculties and 49 departments of study. Examines the applicability of Lotka’s Law as a general inverse power (a # 2) and as an inverse square power relationship (a = 2) to the distribution of the research productivity Annamalai University, South India. Two datasets of the research papers (936 and 3370) contributed by Annamalai University academic authors and researchers during the period of 2000-2006 and 2011-2017 were collected from Web of Science Database. A K-S Test was applied to measure the degree of agreement between the distribution of the observed set of data against the inverse general power relationship and the theoretical value of a=2. It was found that the inverse square law of Lotka does not show conformity as such

Research Output Analysis of Most Productive Universities of Tamil Nadu, India : A Scientometric Analysis

Scientometrics is an important field of information science as it represents a unique set of techniques and tools for the monitoring and analysis of information resources and for the management of knowledge in social and organizational contexts. This article analysed the various Scientometric components of the articles published by top six universities of Tamil Nadu from 2000-2017. The study identifies research trend, characteristics growth and collaboration pattern of published literature. The analysis of data reveals that the average growth rate increases at the rate of 9.76%. Further, the average citation per paper observed is 12.18%. High degree of international collaboration is notified and USA and South Korea are found to be the most preferred collaborative countries. The CAGR calculated for six universities are 9.76. The major research publications outputs are from the field of Chemistry, Crystallography and Pharmacy

Characterization and Performance Evaluation of Mono-grain and Bi-modal PCD Grade in Machining of MMC

AbstractThe aim of this investigation is to study the influence of different parameters such as grain size and cobalt content on the tool performance in the machining of metal matrix composite (MMC) using different polycrystalline diamond (PCD) tools. The experimental tests were conducted with four different PCD grades in dry the milling of Aluminium-Silicon carbide (Al-SiC) composite containing 20% wt of SiC as a workpiece material. The SEM study shows that PCD grades I and II have a bimodal grain size distribution. Rietveld refinement of the XRD spectra for these grades indicates that grade I contains larger amount of Co compared to grade II. The difference in performance between these grades can be explained by the Co content. PCD grade III is a coarse grain grade while grade IV is a fine grain grade. An XRD analysis shows that the main difference between the mono- grain and bimodal grain PCD is the presence of WC in the mono-grain grades which is believed to be added to the raw material of PCD as a grain growth inhibitor. In the XRD pattern for the bimodal grades the peaks in the WC phase are completely absent. The results indicate that the tool performance in terms of wear development is influenced by grain size distribution, cobalt content and the presence of WC; where the abrasive wear is the main wear mechanism which determines the tool life of the diamond grades in milling MMC. The results also indicates that the MMC can be machined with any diamond grade at the low range of cutting speed (≤ 400 m/min) while at a higher range of cutting speed (> 400 m/min) the selection of the diamond grade should be based on the chemical composition and grain size distribution. The presence of grain growth inhibitor also has a significant effect on the tool performance in machining MMC at cutting speeds above 400 m/min

Testing Lotka’s Law and Pattern of Author Productivity in the Scholarly Publications of Artificial Intelligence

Artificial intelligence has changed our day to day life in multitude ways. AI technology is rearing itself as a driving force to be reckoned with in the largest industries in the world. AI has already engulfed our educational system, our businesses and our financial establishments. The future is definite that machines with artificial intelligence will soon be captivating over trained manual work that now is mostly cared by humans. Machines can carry out human-like tasks by new inputs as artificial intelligence makes it possible for machines to learn from experience. AI data from web of science database from 2008 to 2017 have been mapped to depict the average growth rate, relative growth rate, contribution made by authors in the view of research productivity, authorship pattern and collaboration of AI literature. The Lotka’s law on authorship productivity of AI literature has been tested to confirm the applicability of the law to the present data set. A K-S test was applied to measure the degree of agreement between the distribution of the observed set of data against the inverse general power relationship and the theoretical value of α = 2. It is found that the inverse square law of Lotka follow as such

A screening method for banana weevil (Cosmopolites sordidus Germar) resistance using reference genotypes

The banana weevil (Cosmopolites sordidus Germar) is a serious pest in most banana-growing areas of the world. Host-plant resistance is considered to be the most feasible and sustainable method for itscontrol. However, a quick and effective method for screening banana genotypes for resistance against the banana weevil to facilitate selection and/or development of resistant genotypes is lacking. The objective of the study was to develop an early screening method for weevil resistance by using a set of reference genotypes. Three susceptible genotypes (‘Atwalira’, ‘Namwezi’ and ‘Kibuzi’) and three resistant genotypes (‘Calcutta 4’, ‘Yangambi Km5’ and ‘TMB3x1968-2’) were used in screen-houseexperiments to assess weevil resistance/susceptibility. Healthy plantlets of the above genotypes were established in buckets in a screen house. Ten adult weevils (5 females and 5 males) were introduced at the base of each plant and the bucket was covered with a weevil-proof mesh. Weevil damage of the corms was estimated as a percentage at 35 and 60 days after the weevil introduction by estimating the peripheral and cross-section corm damage. The resistant genotypes had significantly lower (p < 0.05)peripheral and total cross-section corm damage, and less larvae than the susceptible genotypes. These results indicated that these genotypes can be used as reference genotypes in evaluating resistance or susceptibility against the banana weevil. These experiments were completed in five to seven months, depending on the source of planting material, as compared to field-screening experiments for the banana weevil that can take up to three or more years