Small-signal stability modelling and analysis of power systems with electronically controlled compensation

Flexible AC Transmission Systems (FACTS) equipment is currently being incorporated into the power system for controlling key networks parameters aiming at improving the power system steady-state and dynamic performances. The vast array of power system analysis tools used by planners and system operators, on a daily basis, for the successful running of the network are to be upgraded to include comprehensive modelling for FACTS plant components. Commensurate with this global objective, this research work is aimed at developing comprehensive power system models of FACTS devices suitable for small-signal stability studies. The FACTS components covered in this research are the Static Var Compensator (SVC) and the Thyristor-Controlled Series Capacitor (TCSC). More specifically, the modelling of these devices combined with advanced modelling of synchronous generators has positioned the current work in the area of small-signal stability modelling and analysis of power systems with electronically controlled compensation. The work has been developed within the framework of the block-diagram methodology because it yields physical insight and offers the opportunity to gain fundamental knowledge of the dynamic interactions taking place between synchronous generators and FACTS plant components. The key issues of synchronous generator modelling, from the viewpoint of small-signal stability analysis, are addressed in this thesis. In particular, the impact of synchronous generator modelling order, with emphasis on system damping, is discussed in depth. Various representations of salient-pole synchronous generators are used to enable a variety of models suitable for small-signal stability studies. The models range from synchronous generators with no danger windings, to cases when one damper winding is included in each of the rotor axes, i.e. d and q-axis. The drive behind the study is to settle the issue of what is a suitable number of machine damper windings to be used in small-signal stability analysis that adequately represents the system model with a good level of reliability while keeping engineering complexity manageable

The Effect of Temperature on the Electrical Characteristics of Nanofluids Based on Palm Oil

This study sought to apply nanotechnology to develop the electrical characteristics of palm oil. Experiments were conducted using three types of nanoparticles: zinc oxide (ZnO), titanium dioxide (TiO2), and barium titanate (BaTiO3). The nanofluid samples were prepared by mixing the nanoparticles with palm oil using various processes. In the first scenario, a combination of palm oil with nanoparticles at 0.01 vol% was created, while the next sample had 0.03 vol% of nanoparticles. The samples were then fully dispersed using a magnetic stirrer, followed by ultrasonic dispersal in order to ensure homogeneity of the nanofluid. The electrodes were set 2.5 mm apart and the test was performed six times on each test sample in compliance with the IEC 60156 standard. The voltage breakdown characteristics were recorded for each of the liquids at temperatures varying from 35 °C to 90 °C. The results showed that for the palm oil samples containing nanoparticles, the voltage breakdown was greater than for the samples containing unmodified palm oil

Exact time dependence of causal correlations and nonequilibrium density matrices in holographic systems

We present the first exact calculations of the time dependence of causal correlations in driven nonequilibrium states in (2+1)-dimensional systems using holography. Comparing exact results with those obtained from simple prototype geometries that are parametrized only by a time dependent temperature, we find that the universal slowly varying features are controlled just by the pump duration and the initial and final temperatures only. We provide numerical evidence that the locations of the event and apparent horizons in the dual geometries can be deduced from the nonequilibrium causal correlations without any prior knowledge of the dual gravity theory.Comment: 6 pages + 3 pages supplemental material, 7 figures (colour), v2: corrected typos, changed colour coding in Fig. 1, v3: to be published in PRD, Fig. 3 split into Figs. 3 and 4, Fig. 5 added, extended introductio

Effective Motorcycle Lane Configuration Thailand: A Case Study of Southern Thailand

Motorcycle lane has proved to be an effective engineering measure in reducing motorcycle crashes and fatalities. Its effectiveness stems from the fact that it helps mitigate the hazards of riding a motorcycle in a traffic stream, which have become a serious cause of death and injury in many countries.This research seeks to develop standardized configurations and widths for motorcycle lanes in Thailand. The optimum format for such a lane may be determined from the simulation of data relating to road accidents, traffic volumes and vehicle speeds.In practice, a range of initial lane widths were inputted into a traffic simulator program - in this case, the VISSIM 5.4 - whose output was analyzed to yield the relationship between MC volume, lane width and level of service (LOS). A pilot test was then performed on a stretch of actual road which had been installed with an MC lane of varying widths. Changes in vehicle speed were observed and employed to determine the relationship between lane width and the actual reduction in vehicle speed and the theoretical reduction in road accidents. Findings of the study point to an efficient lane width in the range of 2.0 to 3.0 m - for the shared lane configuration. For any width outside the said range, the benefit of the MC Lane would be eroded either by the intrusion of larger vehicles, or by the constraining effect of too narrow a lane. The authors also recommends the preferred width for an Exclusive MC Lane which may range from 3.0 to 4.0 m. The lane width of 3.0 m is found to be the most effective in reducing the speed of all traversing vehicles, even when compared with the 2.5 m or 3.5 m widths. With the 3.0 m option, the resulting reduction in speed can be as high as 17%; and reduction of accidents, up to 25%. In view of the aforementioned, the authors recommend configuring for the Shared Motorcycle Lane of 3.0 m with 2 sublanes of 1.5 m width, and for the Exclusive Motorcycle Lane 3.0 - 4.0 m with 2 sublanes of 1.5 to 2.0 m width

Gukov-Pei-Putrov-Vafa conjecture for SU(N)/ZmSU(N)/\mathbb{Z}_m

In our earlier work, we studied the $\hat{Z}$-invariant(or homological blocks) for $SO(3)$ gauge group and we found it to be same as $\hat{Z}^{SU(2)}$. This motivated us to study the $\hat{Z}$-invariant for quotient groups $SU(N)/\mathbb{Z}_m$, where $m$ is some divisor of $N$. Interestingly, we find that $\hat{Z}$-invariant is independent of $m$.Comment: 15 pages, 3 figure

Scientometric study of Research literature output by Madras Medical College during 1989 -2018

Madras Medical College is the one of well-known premier medical institution, situated in Chennai. The data was collected using PubMed database during 1989-2018, there are 646 Publications were found. Analyzed for year wise growth shows 53(8.20%) Publications found during 1989-1993 and Highest 283(43.81%) Publication found during 2014-2018 Authorship pattern shows single author have contributed 35(5.42%), multi author have contributed 611 articles, the mean relative growth rate is 0.0835 and mean doubling time is 14.65. Prolific contributed authors rank 1 occupied by Anand Chockalingam contributed 14(2.16%), 2nd by N, Deivanayagam contributed 13(2.01%),3rd by Ottilingam Somasundaram contributed 12(1.86%). The mean degree of collaboration is 0.930. the prolific contributed journals by authors rank 1 occupied by The Journal of the Association of Physicians of India have published 46 research papers, rank2 occupied by Indian Journal of Dermatology, Venereology and Leprology have published 26 research papers, rank 3 occupied by Indian Journal of Psychiatry have published 20 research papers. The most contributions of research publications by affiliated department 1st. Department of Dermatology, Contributed 70(9.87%), 2nd Institute of Mental Health. Have contributed 41(5.78%) research publications, 3rd Institute of Nephrology. have contributed 40 (5.64%) research publications. The author preferred Language for publication is found to be English, now a days peoples are facing various health problems the postgraduates and faculties should publish their research papers in a Indexed Journals to share their knowledge to the fellow researchers and the funding agencies should encourage the researcher to do their research on current trend on health and diseases

Use of Natural Rubber Latex (NRL) in Improving Properties of Reclaimed Asphalt Pavement (RAP)

Many issues, especially cost, need to be looked at when a new asphalt materials are considered for road construction. One major factor that impacts the cost is the volatility in oil price and stock availability. Consequently, this factor affects both road construction and maintenance by creating uncertainty and financial challenge for Thai manufacturers. Furthermore, all economies, either national or local, depend on adequate road infrastructure and their sound maintenance for growth and development.  One strategy for reducing the overall cost of road construction is through reclamation of existing pavement surfaces that are being repaired or replaced. A process of recycling asphaltic concrete pavement known as Reclaimed Asphalt Pavement (RAP) has been employed in many countries. However, one drawback associated with this practice is the costly investment in the mixing equipment which mechanically rejuvenates the old asphalt pavement by blending it with new asphalt binder. In addition to the high cost of investment, the required quality of the RAP has not been assured due to the lack of enough evidence. The addition of Natural Rubber Latex (NRL) to the process of the recycling asphalt pavement with the aim of reducing production costs and improving the quality of the RAP, offers a promising solution. This paper describes the results of an investigation into the properties of reclaimed asphaltic concrete mix with added NRL. The properties investigated include the Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR). The results show that properties of the NRL modified RAP mix meet the required engineering specifications. The results show that mixing NRL content of 5-15% by weight with RAP and cement content of 3-7% produced a mixture that meet the specification of Thailand Department of Highways in terms of UCS and CBR value for use in layers of pavement. Apart from the positive environmental impact of using recycle material of RAP, the economic and financial benefits to Thailand and  rubber farmers make it worthwhile to use this NRL modified RAP for road construction and maintenance

Literature output on Childhood Schizophrenia; A Scientometric Study during 2009-2018.

Childhood schizophrenia is an extraordinary however extreme mental issue in which kids translate reality anomalous. Schizophrenia involves a range of problems with Intuitions (cognitive), behavior or emotions. The data was collected from PubMed data base using keyword childhood schizophrenia in India, the collected data was arranged in excel format for Analysis. The year wise growth of Literature Output on Childhood Schizophrenia shows 1075 research literature found during 2009-2018, Authorship pattern shows collaborative author contributed more number of research publications than single author contributions, 74 research papers was contributed by single author, Collaborative author contributed 1001 research papers, authors preferred language of publication is found to be English with 1008 (93.8) publications (Rank 1), the most productive or prolific journals contribution on Childhood Schizophrenia is found to be Schizophrenia research have contributed 91(8.47%), occupy the rank 1 position, the prolific authors, Monica Aas have contributed 7 (0.65%)research papers, the top 20 countries with their contributions on Childhood Schizophrenia Research USA have contributed 279(26%) occupy 1 rank, United Kingdom contributed 136(12.7%) occupy 2 rank, Australia contributed 54(5.02%) occupy 3rd rank and India contributed 16(1.49%) occupy 18th rank. the degree of collaboration using Subramaniam formula average Degree of Collaboration found to be 0.931. the relative growth rate and doubling time of research publications, the mean RGR is 0.56 and Doubling time 2.485 was found. From the most prolific affiliated institutions contributions on schizophrenia research was Childhood Psychiatry Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA have contributed 31 research publications. It is observed that the most of the research papers were contributed from developed countries, Indian author contributions rank 18 in childhood schizophrenia research, it is in need that Indian researchers should contribute more research papers on childhood schizophrenia to give awareness to the researchers and share the UpToDate insight knowledge to the other researchers on globe

Using a Social Enterprise Organizational Development Intervention Approach in Developing Organizational Structure and Processes for Start-up Social Enterprise: A Case Study of Trendy Village

Abstract The growth of social enterprises worldwide has initiated innovative and sustainable solutions for a variety of economic, environmental and human development challenges. This social approach has been seen as a new way to add more social value for existing organizations and to generate much more meaningful workplaces for young people who seek greater purpose in their work. Furthermore, with its approach of generating resources through partnerships, this could open up possibilities for an organization that is resource-starved to recognize the value of partnership with other organizations. This article refers to the case of Trendy Village, a business-oriented organization, which was in a negative financial and resource-starved situation. This research focuses on the initial impact of a social enterprise Organization Development Intervention (ODI) approach in generating necessary resources through partnerships with social organizations thus improving its existing condition. The participants are one executive, a team of five members, and 25 vendors in Trendy Village. This study involves action research with qualitative and quantitative components and the steps taken to measure outcomes before and after ODI. The result indicates that ODI could change the stakeholders’ perceptions positively and generate resource support from social organizations. The study concludes that the social enterprise ODI approach brought about a positive impact on the target organization’s organizational structure and processes. Keywords:       organizational structure; organizational process; social enterprise approac