scholarly journals RESONANCE IN SOUTH AFRICAN HARBOURS

1982 ◽  
Vol 1 (18) ◽  
pp. 29
Author(s):  
W.A.M. Botes ◽  
K.S. Russell ◽  
P. Huizinga
Keyword(s):  
Numerical Model ◽  
South African ◽  
Nuclear Power ◽  
Wind Waves ◽  
Cooling Water ◽  
Long Waves ◽  
Single Wave ◽  
Model Studies ◽  
Advantages And Disadvantages ◽  
Transport Services

The geographic situation of Southern Africa, and the associated climate of the South Atlantic Ocean, cause the harbours on the west and south coasts of South Africa to be subjected to resonance or range action caused by longperiod 50 s to 300 s waves. Since the construction of Duncan Dock in Table Bay in 1940, Table Bay harbour has become a classical example of resonance. Range action in the harbour has been studied extensively in the past and extensive physical model studies were undertaken to optimise the layout of the Schoeman Dock, construction of which was completed in 1976. In 1976 South African Railways and Harbours (now South African Transport Services) commissioned the Coastal Engineering and Hydraulics Division of the National Research Institute for Oceanology to optimise plans for future extensions to Table Bay harbour. As a preliminary study, the advantages and disadvantages of all existing methods of simulating resonance were reviewed. For this investigation it was decided to adapt an existing "finite difference" numerical model developed by Leendertse (1967). Prototype long-wave data were gathered in Table Bay and at a later stage at the cooling water intake basin of the Koeberg Nuclear Power Station. These data were used to calibrate the numerical model and an attempt was made to find a correlation between long waves and short wind waves in order to determine the frequency of occurrence of long waves. A method was also developed to incorporate a range of frequencies in one model-run instead of single wave input conditions. This resulted in a considerable reduction of expense and time.

scholarly journals MODEL HARBOUR SEICHING COMPARED TO PROTOTYPE DATA

1984 ◽  
Vol 1 (19) ◽  
pp. 57
Author(s):  
W.A.M. Botes ◽  
K.S. Russell ◽  
P. Huizinga
Keyword(s):  
South African ◽  
Nuclear Power ◽  
Cooling Water ◽  
Long Waves ◽  
Power Station ◽  
The West ◽  
Pressure System ◽  
Long Wave ◽  
Low Pressure System ◽  
Harbour Resonance

Since 1978 a finite-difference numerical model based on that developed by Leendertse and adapted for resonance studies (Russell and Huizinga, 1978) has been applied to investigate harbour resonance in Table Bay Harbour and several other South African ports. During April 1981 three long-wave recorders were installed in the cooling water intake basin of the Koeberg Nuclear Power Station to determine the occurrence and magnitude of the long waves and to measure the corresponding response of the basin. Koeberg is situated on the west coast of South Africa, 30 km north of Cape Town and is exposed to the approaching cyclonic weather systems which experience has shown to be associated with the occurrence of long waves. An example of an approaching low pressure system with the location of Koeberg is shown in Figure 1.

Recent Patents on Valve Mechanism Device

2020 ◽  
Vol 13 (3) ◽  
pp. 230-241
Author(s):  
Ye Dai ◽  
Hui-Bing Zhang ◽  
Yun-Shan Qi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Flow Direction ◽  
Research Progress ◽  
Valve Mechanism ◽  
Advantages And Disadvantages ◽  
Valve Structure ◽  
Valve Leakage ◽  
Safety And Reliability

Background: Valves are an important part of nuclear power plants and are the control equipment used in nuclear power plants. It can change the cross-section of the passage and the flow direction of the medium and has the functions of diversion, cutoff, overflow, and the like. Due to the earthquake, the valve leaks, which will cause a major nuclear accident, endangering people's lives and safety. Objective: The purpose of this study is to synthesize the existing valve devices, summarize and analyze the advantages and disadvantages of various devices from many literatures and patents, and solve some problems of existing valves. Methods: This article summarizes various patents of nuclear-grade valve devices and recent research progress. From the valve structure device, transmission device, a detection device, and finally to the valve test, the advantages and disadvantages of the valve are comprehensively analyzed. Results: By summarizing the characteristics of a large number of valve devices, and analyzing some problems existing in the valves, the outlook for the research and design of nuclear power valves was made, and the planning of the national nuclear power strategic goals and energy security were planned. Conclusion: Valve damage can cause serious safety accidents. The most common is valve leakage. Therefore, the safety and reliability of valves must be taken seriously. By improving the transmission of the valve, the problems of complicated valve structure and high cost are solved.

scholarly journals Ion chromatographic analysis of aqueous iodine species by conductivity and radioactivity measurements

2005 ◽  
Vol 93 (9-10) ◽  
Author(s):  
Dorothea Schumann ◽  
R. Grasser ◽  
R. Dressler ◽  
H. Bruchertseifer
Keyword(s):  
Chromatographic Analysis ◽  
Nuclear Power ◽  
Power Plants ◽  
Radioactive Iodine ◽  
Cooling Water ◽  
Molecular Iodine ◽  
New Device ◽  
Iodine Species ◽  
Radioactivity Measurements

SummaryA new device was developed for the identification of several iodine species in aqueous solution using ion chromatography. Iodide, iodate and molecular iodine can be determined. (The equipment allows both conductivity and radioactivity detections.) The method is applicable for the determination of radioactive iodine contaminations in the cooling water of nuclear power plants.

The structure and application of an automated system for monitoring passenger traffic

2021 ◽  
Vol 14 (3) ◽  
pp. 4-11
Author(s):  
Evgeniy Anikeev
Keyword(s):  
Data Collection ◽  
General Structure ◽  
Automated System ◽  
Passenger Transport ◽  
Service Levels ◽  
Passenger Traffic ◽  
Advantages And Disadvantages ◽  
Transport Services ◽  
Transport Control

Various methods of collecting data on passenger traffic, their advantages and disadvantages are considered. It is shown that in order to improve the quality of transport services, it is necessary to regularly collect and refine data on passenger traffic. The goals and methods of obtaining information about passenger traffic in the system of municipal passenger transport are indicated. All currently existing methods are divided into three categories: data collection using technical means, data collection with the help of censors and volunteers, and interpretation of fare payments. All the methods presented in the article were compared in terms of labor intensity, costs and accuracy of the results obtained. The advantages and disadvantages of each method are considered. The general structure of an automated system for collecting data on passenger traffic is presented. The necessity of creating a centralized system for collecting and processing data associated with all passenger transport control systems has been substantiated. The tasks solved by this system at all levels of transport services for passengers are shown. Each of the tasks is assigned to one of three service levels: pre-transport, transport and post-transport. It is shown that only solving problems at all levels can ensure high-quality operation of the municipal passenger transport system.

Wave Buoy Performance in Short and Long Waves, Evaluated Using Tests on a Hexapod

2018 ◽  
Author(s):  
Sanne van Essen ◽  
Kevin Ewans ◽  
Jason McConochie
Keyword(s):  
Degrees Of Freedom ◽  
Wind Waves ◽  
Long Waves ◽  
Normal Operation ◽  
Period Range ◽  
Multiple Degrees Of Freedom ◽  
Hydrodynamic Response ◽  
Vertical Displacements ◽  
Internal Integration ◽  
Offshore Wave

Offshore wave conditions can be measured using wave buoys, which are generally designed for wind waves. Longer waves (swell or bound second-order waves) are very relevant for certain maritime structures. The accuracy of the instrumentation in a typical wave buoy in long and short waves was therefore studied, and it was investigated if the buoy can be applied in longer waves. A Waverider buoy was placed on a hexapod, which applied regular and irregular prescribed motions in multiple degrees of freedom. The hydrodynamic response of the buoy in waves and the effect of its mooring system were not evaluated; the buoy was assumed to follow the orbital motions of a wave and to rotate with its slope. The tests showed that the buoy sensors measure accelerations and rotations with periods between 1.5 and 35 s very well. Vertical displacements derived from the accelerations by the buoy are accurate for the period range of 2 to 20 s. In longer waves, the motions are significantly underestimated, even though the accelerations are accurately measured. This will not lead to large errors in normal operation, as the energy of such long waves is generally low. This explains why the buoy also performs well when it is subjected to irregular motions (less than 2% error in the significant wave height of a half-hour measurement in realistic irregular sea states with peak periods between 5 and 20 s can be expected). It can be concluded that the buoy accurately measures accelerations. The accuracy of the derived displacements decreases when very long swell wave energy (> 20 s) is present. Review of the internal integration procedure may be considered when there is a specific interest in measuring longer waves.

scholarly journals THE DYNAMIC RESPONSE OF OFFSHORE STRUCTURES TO TIME-DEPENDENT FORCES

1964 ◽  
Vol 1 (9) ◽  
pp. 29
Author(s):  
William S. Gaither ◽  
David P. Billington
Keyword(s):  
Degrees Of Freedom ◽  
Wind Waves ◽  
Offshore Structures ◽  
Time Dependent ◽  
Wave Forces ◽  
Ocean Bottom ◽  
Single Wave ◽  
Single Degree Of Freedom ◽  
The Many ◽  
Floating Objects

This paper is addressed to the problem of structural behavior in an offshore environment, and the application of a more rigorous analysis for time-dependent forces than is currently used. Design of pile supported structures subjected to wave forces has, in the past, been treated in two parts; (1) a static analysis based on the loading of a single wave, and (2) a dynamic analysis which sought to determine the resonant frequency by assuming that the structure could be approximated as a single-degree-of-freedom system. (Ref. 4 and 6) The behavior of these structures would be better understood if the dynamic nature of the loading and the many degrees of freedom of the system were included. A structure which is built in the open ocean is subjected to periodic forces due to wind, waves, floating objects, and due occasionally to machinery mounted on the structure. To resist motion, the structure relies on the stiffness of the elements from which it is built and the restraints of the ocean bottom into which the supporting legs are driven.

scholarly journals АНАЛІЗ ВПЛИВУ ЧИННИКІВ НА ФОРМУВАННЯ СИСТЕМИ ІНТЕГРОВАНОГО ПАРТНЕРСТВА

2021 ◽  
Vol 149 (4) ◽  
pp. 65-75
Author(s):  
Danyil V. Laponoh
Keyword(s):  
Critical Role ◽  
Road Transport ◽  
Public Private Partnership ◽  
Private Partnership ◽  
Economic Relations ◽  
The Road ◽  
Advantages And Disadvantages ◽  
Transport Services ◽  
Wide Range ◽  
Research Findings

This study focuses on a wide range of issues related to the effects of integration process on the development of economic relations, in particular, in the road transport services market. Special emphasis is put on the critical role of integration in contributing to building circular technological supply chains, ensuring sales coordination and management, reducing unit costs and increasing labor productivity. It is argued that the outcome of integration translates into a cohesive economic mechanism which in addition to its integrated elements is characterized by the presence of a core coordination element. The article offers a definition to a public-private partnership phenomenon, identifies its advantages and disadvantages, explores the mechanisms of public-private partnership implementation as well as suggests a toolkit to optimize the partnership functioning for integrated structures. This is a pioneering study that provides a rationale for the need to use several public-private partnership patterns simultaneously together with developing a mechanism for carrying out public-private partnership which is proposed to be consolidated into the mechanism of integrated partnership viewed as the most preferable one to be implemented in the market of road transport services. It has been verified that the integrated partnership pattern provides an opportunity to develop competitive advantages of all its participants. The research findings have enabled to make the following generalizations: the existing partnerships differ in types of arrangements and institutional support; prior to making a decision to launch a specific integrated partnership project, the mechanism of its implementation should be envisaged; to enhance the efficiency of the integrated partnership project implementation, building relevant infrastructure facilities is paramount; the prospects for further integrated partnership project operation assume the utilization of a network mechanism of public-private partnership which best meets the needs and the specifics of the road transport services market.

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