1,720,975 research outputs found
Diagnostics of pumping units of pumping station of machine water lifting
No full textThe purpose of diagnostics is to determine the operability of the pumping units of the pumping station of the machine water lifting at a given time and to identify defects in their components. For this reason, the article presents diagnostic issues for pumping stations No. 1 - No. 6 of the Karshi main canal, designed and commissioned in 1965-1976, where 6 pumping units of the OPV11-260EG type with electric motors of the VDS-375/130-24 type are installed, vertical pumping units, shaft power – 8010 kW, rated power electric motor – 12500 kW, voltage – 10.0 kV, stator current – 825.0 A, maximum permissible temperature of the stator winding – 120 OC, bearing temperature – no more than 70 OC. Diagnostics of the main equipment involves the prompt detection of malfunctions as a result of processing sensor readings of the standard monitoring system, sensor readings are entered manually once a day, and data from monthly and special tests. Technological algorithms of vibration and thermal diagnostics are similar to those developed for vertical pumps installed at thermal power plants, the processes being diagnosed in which are similar to the processes occurring in pumping units of a pumping station. Taking into account the above tasks, algorithms have been developed for diagnosing the main components whose condition affects the performance of the pumping unit: the upper bearing, the upper crosspiece, the stator winding and core, the upper and lower guide bearings, and the electric motor bearing. Possible malfunctions of pumping unit components and ways to eliminate them are given
Analysis of the safety of pumping units of pumping stations of machine water lifting in the function of reliability indicators
No full textThe article presents ways of analyzing the safety of pumping units of pumping stations of machine water lifting in the function of reliability indicators, taking into account the complexity of analyzing the safety of pumping stations of machine water lifting and presenting the pumping unit of a pumping station as a "system", as well as taking into account the need to attract information about their functional scheme, information about the reliability indicators of the elements included in these schemes, information about the adopted system of maintenance and repair, as well as the criteria for the failure of such systems, structural schemes for calculating the reliability of the pumping unit have been developed. The developed structural scheme for calculating the reliability of a pumping unit is presented, consisting of an electric motor, a pump, a power supply network, a control device, a converter, a machine exciter or a semiconductor excitation system, a winding, active steel, an excitation winding, a collector-brush apparatus, a bearing, guide bearings, an oil cooler, an air cooler of an electric motor, a working ring, guide bearings, system lubrication of pump bearings. Structural diagrams are also given for four variants of the design layout of pumping units: each pumping unit supplies water to its pipeline; several pumping units operate in one common pressure pipeline; the main and backup pumping units are connected in series; pumping units are connected to a common pressure pipeline in series-parallel. Based on these structural schemes, formulas for determining the probability of trouble-free operation of the pumping unit and pumping units, considering their structural layout, are compiled. The article assumes that the uptime of the synchronous motor of the pumping unit is distributed exponentially, and the law of the repair time distribution corresponds to the gamma distribution
Algorithm and Software Implementation of the Diagnostic System for the Technical Condition of Powerful Units
No full textThis article discusses the software implementation of the diagnostic system for auxiliary equipment of power plants (on the example of smoke exhausters). The developed program of diagnostics of auxiliary equipment of electric power plants is given on the example of condition diagnostics designed for early detection and localization of certain defects and providing recommendations for their elimination in smoke pumps, which should ensure the issuance of appropriate protocols and, upon request, protocols of the current state of smoke pumps, quality assessment of repairs and special tests, as well as graphs of retrospective parameter values for the time period selected by the user, where the users of the task - there are heads and deputy heads of workshops, senior foremen, repair engineers, as well as specialists of the planning and technical department. The problem is considered, which was solved within the framework of the software and hardware complex of the automated process control system) of the 800 MW power unit No.1 of Talimarjan TPP and is intended for operational specialists, where the task operates under the Windows operating system and the program is written in the C++ programming language Builder 6 for the development of application tasks with client -server architecture. And also the composition of the program and the program menu are given: “Task Launch”, “Daily statements”, “Input data”, “Output forms”, “Diagnostics” and “Special tests” allow you to implement the required task function at the moment. In addition, the article presents elements and components, processes and conditions of a pumping plant, pumping station and pumping station cascade, potentially dangerous and processes and conditions potentially dangerous for a pumping plant, pumping station and pumping station cascade
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Modern state of the energy sector of Uzbekistan and issues of their development
No full textThe data on the current state of the energy sector in Uzbekistan are presented. The need to diversify the structure of the republic’s energy balance is shown to ensure the energy security of the state in the medium and long term. The development of the energy sector is extremely important for ensuring sustainable economic growth and solving social problems of the state; as well as the development and modernization of the electrical system, the oil and gas sector, the construction of a nuclear power plant and a gradual transition to renewable energy sources are strategic directions for the development of the fuel and energy complex of Uzbekistan. It is argued that the construction of a nuclear power plant in Uzbekistan is not only advisable, but also necessary. The issues of the prospects for the development of renewable and nuclear energy sources in Uzbekistan, issues of investment and system costs with different shares of their participation in electricity generation are considered. It has been developed and shown that in the future, based on the symbiosis of renewable nuclear energy, by the middle of the 21st century, conditions for carbon-neutral energy can be formed in the economy of Uzbekistan
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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