Predicting Voltage Abnormality Using Power System Dynamics

The purpose of this dissertation is to analyze dynamic behavior of a stressed power system and to correlate the dynamic responses to a near future system voltage abnormality. It is postulated that the dynamic response of a stressed power system in a short period of time-in seconds-contains sufficient information that will allow prediction of voltage abnormality in future time-in minutes. The PSSE dynamics simulator is used to study the dynamics of the IEEE 39 Bus equivalent test system. To correlate dynamic behavior to system voltage abnormality, this research utilizes two different pattern recognition methods one being algorithmic method known as Regularized Least Square Classification (RLSC) pattern recognition and the other being a statistical method known as Classification and Regression Tree (CART). Dynamics of a stressed test system is captured by introducing numerous contingencies, by driving the system to the point of abnormal operation, and by identifying those simulated contingencies that cause system voltage abnormality. Normal and abnormal voltage cases are simulated using the PSSE dynamics tool. The results of simulation from PSSE dynamics will be divided into two sets of training and testing set data. Each of the two sets of data includes both normal and abnormal voltage cases that are used for development and validation of a discriminator. This research uses stressed system simulation results to train two RLSC and CART pattern recognition models using the training set obtained from the dynamic simulation data. After the training phase, the trained pattern recognition algorithm will be validated using the remainder of data obtained from simulation of the stressed system. This process will determine the prominent features and parameters in the process of classification of normal and abnormal voltage cases from dynamic simulation data. Each of the algorithmic or statistical pattern recognition methods have their advantages and disadvantages and it is the intention of this dissertation to use them only to find correlations between the dynamic behavior of a stressed system in response to severe contingencies and the outcome of the system behavior in a few minutes into the future

Applicability of Sri Lanka public sector accounting standards: Trincomalee urban council, Sri Lanka

Though the Sri Lankan Local Governments were introduced with the accrual based Public Sector Accounting Standards from 2009 they have not been implemented yet. As a result, the present study focuses why it has been a failure and sees the applicability of the standards to the Local Governmental set up in Sri Lanka. The Urban Council of Trincomalee city was selected as the case for study and semi structured interviews were conducted. The study concludes that since the accounting system (Wickramanayake’s accounting system) already in place was based on accrual principles, the application of accrual based accounting standards are possible provided that the staffs’ professional expertise is improved to the level expected

Pattern Recognition of Power Systems Voltage Stability Using Real Time Simulations

The basic idea deals with detecting the voltage collapse ahead of time to provide the operators a lead time for remedial actions and for possible prevention of blackouts. To detect cases of voltage collapse, we shall create methods using pattern recognition in conjunction with real time simulation of case studies and shall develop heuristic methods for separating voltage stable cases from voltage unstable cases that result in response to system contingencies and faults. Using Real Time Simulator in Entergy-UNO Power & Energy Research Laboratory, we shall simulate several contingencies on IEEE 39-Bus Test System and compile the results in two categories of stable and unstable voltage cases. The second stage of the proposed work mainly deals with the study of different patterns of voltage using artificial neural networks. The final stage deals with the training of the controllers in order to detect stability of power system in advance

Pattern Recognition of Power Systems Voltage Stability Using Real Time Simulations

The basic idea deals with detecting the voltage collapse ahead of time to provide the operators a lead time for remedial actions and for possible prevention of blackouts. To detect cases of voltage collapse, we shall create methods using pattern recognition in conjunction with real time simulation of case studies and shall develop heuristic methods for separating voltage stable cases from voltage unstable cases that result in response to system contingencies and faults. Using Real Time Simulator in Entergy-UNO Power & Energy Research Laboratory, we shall simulate several contingencies on IEEE 39-Bus Test System and compile the results in two categories of stable and unstable voltage cases. The second stage of the proposed work mainly deals with the study of different patterns of voltage using artificial neural networks. The final stage deals with the training of the controllers in order to detect stability of power system in advance

An overview: Matrix tablets as sustained release.

Oral route is the most preferred route for administration of drugs. Tablets are the most popular oral formulation available in the market and preferred by the patients and physician alike. In long-term therapy for the treatment of chronic disease conditions, conventional formulations are required to be administered multiple doses and therefore have several disadvantages. The primary benefit of a sustained release dosage form compared to a conventional dosage form, is the uniform drug plasma concentration and therefore uniform therapeutic effect. Matrix system are favored because of their simplicity, patient compliance etc, than traditional drug delivery which have many drawbacks like repeated administration, fluctuation in blood concentration level etc. Introduction of Matrix tablet as Sustained release has given a new break through for novel drug delivery system (NDDS) in the field of Pharmaceutical technology. Matrix systems are widely used for the purpose of sustained release. It is the release system which prolongs and controlls the release of drug that is dissolved or dispersed. In fact, a matrix is defined as a well-mixed composite of one or more drugs with gelling agent i.e. hydrophilic polymers. By the sustained release method therapeutically effective concentration can be achieved in the systemic circulation over an extended period of time, thus achieving better compliance of patients. Numerous sustained release oral dosage forms such as membrane controlled system, matrices with water soluble/insoluble polymers or waxes and osmotic systems have been developed, intense research has been recently focused on the designed of sustained release systems for poorly water soluble drugs

DESIGN AND EVALUATION OF FAST DISSOLVING TABLETS OF ERGOTAMINE TARTARATE

Objective: The main objective of this study was to formulate and evaluate the fast dissolving tablets of ergotamine tartarate with synthetic superdisintegrants. Methods: Various formulations were prepared by direct compression method using different concentrations of crospovidone (12.5%-62.5%) and croscarmallose sodium (12.5%-62.5%) as superdisintegrants. Formulations were evaluated for precompressional parameters and postcompressional parameters like uniformity of weight, thickness, hardness, friability, drug content, wetting time, the water absorption ratio, in vitro disintegration time and in vitro dissolution study. Results: Results revealed that among the 10 formulations, the formulation F5 containing 62.5% of crospovidone and formulation F10 containing 62.5% of croscarmallose sodium was found to be promising formulations. F5 shown disintegration time of 12 seconds and the drug release was up to 96% in 30 minutes and F10 shown disintegration time of 18 seconds and the drug release was up to 89% in 30 minutes. Conclusion: From the result obtained, it can be concluded that formulation of fast dissolving tablet using crospovidone as a superdisintegrant showed improved disintegration and solubility and hence better patient complianc

Genetic analysis of foot-and-mouth disease virus serotype A of Indian origin and detection of positive selection and recombination in leader protease- and capsid-coding regions

The leader protease (Lpro) and capsid-coding sequences (P1) constitute approximately 3 kb of the foot-and-mouth disease virus (FMDV). We studied the phylogenetic relationship of 46 FMDV serotype A isolates of Indian origin collected during the period 1968-2005 and also eight vaccine strains using the neighbour-joining tree and Bayesian tree methods. The viruses were categorized under three major groups-Asian, Euro-South American and European. The Indian isolates formed a distinct genetic group among the Asian isolates. The Indian isolates were further classified into different genetic subgroups ( < 5% divergence). Post-1995 isolates were divided into two subgroups while a few isolates which originated in the year 2005 from Andhra Pradesh formed a separate group. These isolates were closely related to the isolates of the 1970s. The FMDV isolates seem to undergo reverse mutation or convergent evolution wherein sequences identical to the ancestors are present in the isolates in circulation. The eight vaccine strains included in the study were not related to each other and belonged to different genetic groups. Recombination was detected in the Lpro region in one isolate (A IND 20/82) and in the VP1 coding 1D region in another isolate (A RAJ 21/96). Positive selection was identified at aa positions 23 in the Lpro (P < 0.05; 0.046∗) and at aa 171 in the capsid protein VP1 (P < 0.01; 0.003∗∗)

Emergency foot-and-mouth disease vaccines a Malaysia 97 and A₂₂ Iraq 64 offer good protection against heterologous challenge with a variant serotype a ASIA/G-IX/SEA-97 lineage virus

The continuous emergence of foot-and-mouth disease virus (FMDV) serotype A variants in South East Asia is of concern for international FMDV antigen banks, especially when in vitro tests predict a low antigenic match. A vaccination-challenge study was performed by using two emergency FMDV vaccines with A22 Iraq 64 (A22 IRQ) and A Malaysia 97 (A MAY 97) strains, against challenge with a variant strain of FMDV A/Asia/G-IX/SEA-97 lineage at 7- and 21-day post-vaccination (dpv). At 7 dpv, three of five female calves vaccinated with A MAY 97 and four of five vaccinated with A22 IRQ did not show lesions on the feet and were considered protected, while at 21 dpv all five calves were protected with each vaccine, indicating equal efficacy of both vaccine strains. Calves were protected despite relatively low heterologous neutralizing antibody titers to the challenge virus at the time of challenge. All the calves developed antibodies to the non-structural proteins, most likely due to the direct intradermolingual (IDL) inoculation. Only one calf from the A MAY 97-7 group had infectious virus in the serum 1–3-day post-challenge (dpc), while no virus could be isolated from the serum of cattle challenged on 21 dpv. The virus could be isolated from the oral swabs of all calves, 1–7 dpc with viral RNA detected 1–10 dpc. Nasal swabs were positive for virus 1–6 dpc in a small number of calves. The time between vaccination and infection did not have an impact on the number of animals with persistent infection, with almost all the animals showing viral RNA in their oro-pharyngeal fluid (probang) samples up to 35 dpc. Despite the poor in vitro matching data and field reports of vaccine failures, this study suggests that these vaccine strains should be effective against this new A/Asia/G/SEA-97 variant, provided they are formulated with a high antigen dose.</p

Socio-Economic Factors and Tourism – Impact Analysis using Indicator Approach

The study uses an indicator approach to assess the socioeconomic impact on tourism in developing countries, using Sri Lanka as a case. Tourism is a flourishing sector in Sri Lanka that was affected by different aspects such as pandemics, terrorism, and economic, social, and political instabilities. Though the effects of these events have been studied separately, studies done to assess the socio-economic impact of tourism in Sri Lanka using an indicator approach are scarce; hence the study aims to fill this prevailing knowledge gap. Based on data availability, the study uses secondary data from Sri Lanka Tourism Development Authority and Central Bank reports of Sri Lanka from 2010 to 2019. The socio-economic impact of tourism is measured using integral indicators calculated using the coefficients and weights of the data collected. The study concludes that tourism in Sri Lanka has had a positive socioeconomic impact and has increased continuously since 2010 except in 2019, due to the aftermath of the Easter Sunday attacks in April 2019. This study indeed provides a stepping stone to study the Sri Lankan Tourism Sector which is currently going through political and economic turmoil