Top PDF Contributions to the Analysis and the Supervision of a Thermal Power Plant

Contributions to the Analysis and the Supervision of a Thermal Power Plant

Contributions to the Analysis and the Supervision of a Thermal Power Plant

Abstract—Supervision systems play an important role in industry mainly due to the increasing demand for product quality and high efficiency, and to the growing integration of automatic control systems in technical processes. In fact, the supervision system has a great number of components and interconnections, and it is difficult to describe and understand its behavior. Furthermore, the supervision system in industrial plants, implemented in supervisory control and data acquisition (SCADA) software, must undertake, at least, the following three main tasks: monitoring, control and fault tolerance. So it can be classified as a complex system. The objective of this paper is to show interests of the use of functional analysis techniques such as SADT (Structured Analysis and Design Technique) and SA-RT (Structured Analysis Real Time) for the design of supervisory systems. This is why we present a general model of analysis and supervision of production systems. This model was based on the one hand on the functional analysis (FA) and on the other hand on the SCADA system.
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Determining the reliability function of the thermal power system in power plant "Nikola Tesla, Block B1"

Determining the reliability function of the thermal power system in power plant "Nikola Tesla, Block B1"

Different probabilistic techniques could be applied for analysis of the statistical set of data obtained by the exploitation survey of the thermal system in TENT-B1. The use of grafical method and probability papers in order to find a class of distribution function and their parame- ters, despite their relative simplicity, have a number of benefits that can meet the requirements beyond the scope of engineering practice [11]. Moreover, the proposed graphical method oftenly provides a better understanding about the behavior of any repairable system [12].
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Analysis and optimization of pressure reducing and desuperheating system in thermal power plant

Analysis and optimization of pressure reducing and desuperheating system in thermal power plant

Abstract : Steam Pressure Reducing and Desuperheating System (PRDS) is used for Steam Conditioning Services for reduction of pressure and temperature of steam. Suitably designed pressure reducing valve installed on superheated steam line, reduces steam pressure to desired operating pressure. The steam temperature is reduced close to saturation by injecting water into high velocity steam by controlled water flow through water control valve and often injected into the steam where steam velocity and turbulence are at their highest, which gives quick and efficient cooling. The purpose of this project is to optimize the Pressure reducing and desuperheating system to overcome the current losses such as valve leakage, gland leakage and header leakage. The primary approach to our project is focused on reducing the pressure of the steam in stages and various process parameters such as positioning of nozzles, number of nozzles, positioning of pressure reducing valves, piping material, turbulence developed due to the present design and pipe dimensions with respect to the steam characteristics will be studied. ANSYS for numerical simulations are employed to predict the optimized conditions. Our project deals with the detailed study of PRDS and implementing proper analysis tool to provide a detailed analysis of different components of the system to bring about improvement in design, evaluation, optimization of the system and also to indicate the need for further research.
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Markov approach to evaluate the availability simulation model for power generation system in a thermal power plant ,

Markov approach to evaluate the availability simulation model for power generation system in a thermal power plant ,

In recent years, the availability of power plants has become increasingly important issue in most developed and developing countries. This paper aims to propose a methodology based on Markov approach to evaluate the availability simulation model for power generation system (Turbine) in a thermal power plant under realistic working environment. The effects of occurrence of failure/course of actions and availability of repair facilities on system performance have been investigated. Higher availability of the components/equipments is inherently associated with their higher reliability and maintainability. The power generation system consists of five subsystems with four possible states: full working, reduced capacity, reduced efficiency and failed state. So, its availability should be carefully evaluated in order to foresee the performance of the power plant. The availability simulation model (Av.) has been developed with the help of mathematical formulation based on Markov Birth-Death process using probabilistic approach. For this purpose, first differential equations have been generated. These equations are then solved using normalizing condition so as to determine the steady state availability of power generation system. In fact, availability analysis is very much effective in finding critical subsystems and deciding their preventive maintenance program for improving availability of the power plant as well as the power supply. From the graphs illustrated, the optimum values of failure/repair rates for maximum availability, of each subsystem is analyzed and then maintenance priorities are decided for all subsystems.The present paper highlights that in this system, Turbine governing subsystem is most sensitive demands more improvement in maintainability as compared to the other subsystems. While Turbine lubrication subsystem is least sensitive.
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Thermal Analysis of Heat Pipe Using Taguchi Method

Thermal Analysis of Heat Pipe Using Taguchi Method

The heat pipe is a novel heat transfer device to transfer large amount of heat through a small cross sectional area with very small temperature differences and it also posses high thermal conductance and low thermal impedance. In this paper, the heat pipe working parameters are analyzed using Taguchi methodology. The Taguchi method is used to formulate the experimental work, analyze the effect of working parameters of the heat pipe and predict the optimal parameter of heat pipe such as heat input, inclination angle and flow rate. It is found that these parameters have a significant influence on heat pipe performance. The analysis of the Taguchi method reveals that, all the parameters mentioned above have equal contributions in the performance of heat pipe efficiency, thermal resistance and overall heat transfer coefficient. Experimental results are provided to validate the suitability of the proposed approach.
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Bank Privatization and Market Structure of the Banking Industry: Evidence from a Dynamic Structural Model

Bank Privatization and Market Structure of the Banking Industry: Evidence from a Dynamic Structural Model

a Dynamic Structural Model”. We are indebted to Martin Pesendorfer for his support and guidance during this project. We would like to thank Dimitri Szerman for the help with the data and for insightful comments on several versions of this draft. Robinson Silva helped us to organize the data. We also benefited from discussions with Bernardo Guimarães, Bruno Rocha, Emmanuel Guerre, Fabio Pinna, Francesco Caselli, Francisco Costa, Gabriel Garber, Jason Garred, Joachim Groeger, Johannes Spinnewijn, Maitreesh Ghatak, Matthew Gentry, Michael Dickstein, Panle Jia, Pasquale Schiraldi, Pedro Carvalho, Robert Miller and Tim Besley. Fabio gratefully acknowledges the financial support from CAPES (Brazilian Ministry of Education) and Daniel gratefully acknowledges the support from CNPQ (Brazilian Ministry of Science and Technology). The usual disclaimer applies.
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Buying Behavior Of Organic Vegetables Product The Effects Of Perceptions Of Quality And Risk

Buying Behavior Of Organic Vegetables Product The Effects Of Perceptions Of Quality And Risk

products (Kim & Chung, 2011:40), so it’s important to recognize consumer purchasing behavior. Many companies use marketing strategies by analyzing consumer behavior in order to study the effect on purchase decision (Jalalkamali & Nikbin, 2010:235). The purchase decision is also influenced by the perceived quality which is also an aspect of brand value that makes consumers pay for certain products or services (Yaseen et al., 2011:833). It confirms that the consumer purchase decision on products or services is strongly influenced by customer perception of quality of value brand. Decision making is a way of choosing between two or more possible options when a person has a choice between purchasing or not (Schiffman & Kanuk, 2007). In the assessment stages of different choices, the consumers classify different brands and the purchase intention is created in his mind. Shareef et al. (2008) revealed purchase decision is a continuous process, which refers to thoughtful, consistent action undertaken to bring about need satisfaction. Choubtarash et al. (2013) confirmed that purchase decision is a person in the mind who is carefully analyzing the features of products, trademarks or services and tries, by using logical methods, to choose a choice that can satisfy the recognized need with the least expenses. Consumers perceived organic as a healthier alternative to conventional foods in that they contain more nutrients which enhance personal well-being organic produce is also considered safer and better in taste and more enjoyable than conventional products (Shaharudin et al., 2010:72). Last organic purchasing is defined as purchasing goods and services which have less harmful for environmental and human health (Othman & Rahman, 2014:93). Purchasing decisions can be measured through several dimensions, including recommend, purchase frequency, overall satisfaction and purchase intention (Shareef et al., 2008:101). The measure is not different from the study by Liu et al. (2009:72) which provide specifications for purchasing decisions by some measures, including product selection, brand selection, object selection, purchase opportunity, and purchase quantity. Consumer purchasing decisions on products had relationship with consumer perceptions of quality and risk products (Yee et al., 2011:47). Consumer interest in the products can be improved by an increase in the quality of products (Kwak & Kang, 2009:85). And previous research has argued that a consumer perception of quality has a positive impact on consumer buying behavior (Wang & Tsai, 2014:27). Based on these studies, next hypothesis as follows:
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Prostate Cancer: A State of The Heart

Prostate Cancer: A State of The Heart

Surgical castration, oestrogens, LHRH agonists and GnRH antagonists, anti-androgens, combined androgen blockade (CAB), and 17,20-lyase inhibitors are some of the treatment options available to a patient with CV risk factors and known metastatic disease. Due to the high rate of thromboembolic events with oral oestrogen, it has somewhat been abandoned as a therapy. The oestrogen patch, however, is not thought to induce thromboembolic events. Prof Klotz described a study comparing a LHRH agonist and a transdermal oestrogen patch in which the use of the patch did not increase the number of CV events versus the LHRH agonist, suggesting that this may be regarded as a potential therapeutic option. 3 LHRH agonists have
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The Influence of Small Amounts of Aluminium on the Spheroidization of Cast Iron with Cerium Mischmetal

The Influence of Small Amounts of Aluminium on the Spheroidization of Cast Iron with Cerium Mischmetal

Introduction of aluminium in the quantity of either about 0.6% (the alloy from melt No. 1) or about 1.1% (the alloy from melt No. 2) leads to the arising of the ferrite-pearlite matrix containing the precipitates of free cementite despite the significant silicon content in the cast iron (see data in Table 4 and Figs 2 and 4). The cast iron from these two melts did not contain the regular nodular graphite precipitates. In both cases the shape of graphite precipitates, according to the Standard [15], can be classified as II, its distribution as B, magnitude as 6 (see Figs 1 and 3).
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Device for Monitoring - Warning Frequency Generator

Device for Monitoring - Warning Frequency Generator

Power quality was assessed by two parameters voltage and frequency, the voltage changes are of a local property, and change the frequency – systematic. Frequency deviation in the grid due to an imbalance in power between the generator and the load will affect the economic and technical indicators of power stations, as well as consumers. To ensure the stability and reliability of the electric system and generator protection to prevent damage during the operation, it is necessary and indispensable device monitoring – warning frequency generator in power stations.
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Human Capital and the Recent Fall of Earnings Inequality in Brazil

Human Capital and the Recent Fall of Earnings Inequality in Brazil

Brazil has the world’s eighth largest economy (IMF, 2008). Nevertheless, 21.4 % of the country’s people live in poverty, and 7.3% in misery (IPEADATA, 2009). This contradiction is the result of the country’s glaring income inequality (UNDP, 2010) 1 . But, after decades remaining at a very high and stable level, inequality has recently started to decline in Brazil and in several other Latin- American countries (Lopez-Calva and Lustig, 2010). The aim of this paper is to understand the reasons behind the fall of the Brazilian inequality, using a flexible econometric approach and focusing on the role played by education and age.
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The Impact of E-Commerce Securi ty, and National Environment  on Consumer adoption of Intern et Banking in Malaysia and  Singapore

The Impact of E-Commerce Securi ty, and National Environment on Consumer adoption of Intern et Banking in Malaysia and Singapore

Relative advantage is defined as the extent to which a person views an innovation as offering an advantage over previous ways of performing the same task (Roger, 1983; Agarwal & Prasad, 1997). Because Internet banking services allow customers to access their banking account from any location 24 hours a day and 7 days a week, it provides an enormous advantage and convenience to users (Tan & Teo, 2000). It also gives customers greater control over managing their finances, as they are able to check their accounts easily. Besides, a customer’s Internet experience, his or her banking needs can affect his adoption. As there are more financial products and services, it is expected that individuals with many financial accounts and who subscribe to many banking services will be more inclined to adopt Internet banking. Tan and Teo (2000) has reported that potential adopters of Internet banking services are likely to own multiple banking accounts and subscribe to various banking services. Rogers argues that potential adapters, who are allowed to experiment with an innovation will feel more comfortable with the innovation and are more likely to adopt it. Thus, if customers have the opportunity to try the innovation, certain fears of the unknown may be minimized. Government policy could also aid or hinder Internet diffusion (Mbarika, 2002). This is consistent with the national systems of innovation theory that posits that government policies may encourage or mandate technology development and adoption (King et. al., 1994; Wolcott et. al., 2001). Tan and Teo (2000) suggest that the greater the extent of government support for Internet commerce, the more likely Internet banking will be adopted, thus, confirming Goh’s (1995) suggestion that governments can play an interventionist and leading role in the diffusion of innovation. Potential users in turn would view new applications such as Internet banking services more favorably and hence be more like to use them. Thus, the second alternative hypothesis is:
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Influence of tungsten and titanium on the structure of chromium cast iron

Influence of tungsten and titanium on the structure of chromium cast iron

The paper analyses the as-cast state structure of chromium cast iron designed for operation under harsh impact-abrasive conditions. In the process of chromium iron castings manufacture, very strong influence on the structure of this material have the parameters of the technological process. Among others, adding to the Fe-Cr-C alloy the alloying elements like tungsten and titanium leads to the formation of additional carbides in the structure of this cast iron, which may favourably affect the casting properties, including the resistance to abrasive wear.
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The Effects of Gender Segregation at the Occupation, Industry, Establishment, and Job-Cell Levels on the Male-Female Wage Gap

The Effects of Gender Segregation at the Occupation, Industry, Establishment, and Job-Cell Levels on the Male-Female Wage Gap

On the firms’ side, the fixed effects absorb unobserved heterogeneity in a large set of factors such as their management productivity, discrimination practices, technologies, job attributes, work conditions, and compensation policies. All these dimensions can affect gender sorting across establishments. If females are more frequently hired to work at es- tablishments that pay lower wages, unless establishment fixed effects are controlled for, a negative relationship between wages and female segregation is likely to appear in the data. In one specification of the model, we use a job-match fixed effect which is intended to capture unobserved heterogeneity in worker-firm matches. This specification is quite rich in that it captures the “quality” of the match between the unobserved characteristics of the workers (job preferences, abilities/skills, etc.) and firms (job characteristics, work conditions, etc.). In addition, job match quality also captures the production complementarities between the worker and the firm (Woodcock, 2007). As shown by Woodcock (2008), the quality of job matches is important for wage determination. If the sorting process of workers in the labor market is correlated with differences in job characteristics and match-specific productivity, “good” and “bad” matches can influence not only gender segregation across firms but also across industries and even occupations. 7 Thus, controlling for match-specific fixed effects
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White and gray solidification of the Fe-C eutectic

White and gray solidification of the Fe-C eutectic

This means that branching of graphite, which is needed for growth at the optimum-lamellar spacing, is difficult. The lamella of graphite will then grow straight in a converging or diverging way, leading to a whole range of lamellar spacing (corresponding to a range of undercooling given by eq. (1)). It has been shown that growth cannot be achieved with a spacing lower than the extreme one. Growth of converging lamella will then stop when this spacing is reached. At the opposite, growth of diverging lamella will be stable only as long as is less than a critical spacing br where branching occurs, as shown in fig. 3.
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Theoretical and Methodological Aspects of the ”Integration Process” Phenomenon

Theoretical and Methodological Aspects of the ”Integration Process” Phenomenon

As a result of researches conducted on the European Coal and Steel Community the theses of neofunctionalists appear vis-a-vis of integration. Neofunctionalism can be considered as a gradual shift from functionalism to federalism, whose starting point was the development of the common market. Given that the main representatives as B. Haas and L. Lindberg, Neofunctionalist School argues that certain prerequisites are necessary for integration to move forward. It is necessary that public opinion to be in favor of cooperation, the elites, from the pragmatic interests rather and not from altruistic reasons, to want to promote integration and the new supranational structures to be equipped with real power. With the creation of these premises, there is an extension of the integration, caused by so by the so-called “spillover” effect, as there is a process of "overflow" and "expansion" of integration in other fields of activity. Common activity in a sector creates new needs, gaps and problems putting pressure on political actors for this to expand joint activities and the other sector. For example, free movement of people only works if there is cooperation in home affairs and justice, free movement of pensions, comparable working conditions, mutual recognition of diplomas (Stvil, 2001; Stepen, 1996:36-39).In view of this theory, establishing the European Coal and Steel Community (ECSC) achieved an integration of coal and steel industries, of the six Member States, overseen by a central institution, the ”High Authority” with supranational powers.
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An Advancement To The Security Level Through Galois Field In The Existing Password Based Technique Of Hiding Classified Information In Images

An Advancement To The Security Level Through Galois Field In The Existing Password Based Technique Of Hiding Classified Information In Images

IEEE standard images for different number of ASCII characters. Tables 1-2 indicate the PSNR values for various Stego-images of size 256 x 256 using the proposed techniques, calculated for 1500 characters. We conducted further experiments with the Lena image using more characters. Table 2 indicates the PSNR values for the Lena image calculated for up to 1997 characters using the three suggested techniques. Thus, using the proposed method, up to 1997 characters (or 15,976 bits) have been embedded in a 256 x 256 pixel image. This shows that, 12.5% of the image pixels are used to embed 15,976 bits and yet the perceptual quality of the stego-image is still high. The PSNR of the third method can be controlled depending on number of bits being stored in various positions. Considering a minimum of 34 dB PSNR threshold for stego-image perceptual quality [11] It is clear from the obtained PSNR values that the proposed technique can generate stego-images with good perceptual quality. For qualitative assessment, , Figures 11(a), 11(b) show the Baboon image before and after steganography using the proposed technique for 500 characters. Figures 12(a) and 12(b) show the Lena image using the proposed technique, for 1997 ASCII characters.
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Evaluating the influence of selected parameters on sensitivity of a numerical model of solidification

Evaluating the influence of selected parameters on sensitivity of a numerical model of solidification

Presented paper contains evaluation of influence of selected parameters on sensitivity of a numerical model of solidification. The investigated model is based on the heat conduction equation with a heat source and solved using the finite element method (FEM). The model is built with the use of enthalpy formulation for solidification and using an intermediate solid fraction growth model. The model sensitivity is studied with the use of Morris method, which is one of global sensitivity methods. Characteristic feature of the global methods is necessity to conduct a series of simulations applying the investigated model with appropriately chosen model parameters. The advantage of Morris method is possibility to reduce the number of necessary simulations. Results of the presented work allow to answer the question how generic sensitivity analysis results are, particularly if sensitivity analysis results depend only on model characteristics and not on things such as density of the finite element mesh or shape of the region. Results of this research allow to conclude that sensitivity analysis with use of Morris method depends only on characteristic of the investigated model.
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CONTINUOUS CREATION IN THE PROBABILISTIC WORLD OF THE THEOLOGY OF CHANCE

CONTINUOUS CREATION IN THE PROBABILISTIC WORLD OF THE THEOLOGY OF CHANCE

I think we can answer this question in the positive: Yes, He can, because He is the most perfect being and His omnipotence is absolutely unlimited. A very important premise underlying the answer to the last question is that the risk is not so great, or even that it is very small. It is so because the nature and mechanism of the created world ensure with a very high proba- bility that all purposes intended by God will be attained without his causal action in the processes occurring in the world. The emergence of life in the universe is almost inevitable, because the universe is large and old enough, and biochemical mechanisms are very effective. The emergence of sentient beings was also almost inevitable because of longstanding and countless mutations and adaptations of living organisms to their environment. All this was very probable and hence in a sense necessary (inevitable). The great advantage of the non-deterministic world is its own creativity, which is possible because of the chance events happening in a way restricted only by the laws of nature. Thus, if one evolutionary path fails another one is opened. Perhaps a mutation suitable for the growth and development of a given species happened by chance and enabled it to survive in hard con- ditions and further develop. Elasticity and redundancy are very typical for the world of chance, but because of these properties, this world has a large number of possibilities and abilities to develop and regenerate after various natural catastrophes (Łukasiewicz 2006).
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Calculating the uncertainty associated to the forecast of species dispersals: Stochastic Flow Connectivity

Calculating the uncertainty associated to the forecast of species dispersals: Stochastic Flow Connectivity

To date, corridors for species dispersals have been thought as deterministic outputs emerging from some kind of model. Uncertainty about the individuation of biotic corridors has never been considered. Flow connectivity (FC) is a methodology first introduced in 2013 to forecast biotic flows over real landscapes, alternative to both circuit theory and least-cost modelling. Its name is due to the fact that it resembles in some way the motion characteristic of fluids over a surface. FC predicts species dispersal by minimizing at each time step the potential energy due to fictional gravity force over a frictional 3D landscape built upon the real landscape. In this work, FC is further developed to find a solution to the problem of calculating the uncertainty associated to the forecast of species dispersals. The output of this method is an “uncertainty polygon” (e.g., 5% or 10% uncertainty) around the predicted biotic flow. The importance of this new variant of FC is clear: when planning greenways for biodiversity, uncertainty about biotic flows prediction must be taken into account and the planned corridors must encompass the “uncertainty polygon” as well, otherwise they are at serious risk to underestimate the necessary space required by animal species to flow over landscape.
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