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The Method of Identification the Failure Risk on Water Supply Networks

5. Bibliografia [1] Imran S. A. Sadiq R., Kleiner Y.,, Managing the impact of changing treatment practices on distribution system water quality , WCWWA 60 th Anniversary Conference, Regina, 2008 [2] Kaplan S. Garrick B. J., On the quantative definition of risk Risk Analysis, 1(1)/1981, s. 11-27. [3] Kleiner Y. Rajani B., Sadiq R., Failure risk management of buried infrastructure using fuzzy-based techniques, Journal of Water Supply Research and Technology - AQUA, International Water Association Publishing, 55(2)/2006, s. 81-94. [4

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Effect of settlement of foundations on the failure risk of the bottom of cylindrical steel vertical tanks for liquids

basis of the measured radial deformations u r of the shell. 5 Failure risk of the bottom of the tank due to excessive deformation of the soil Deformations of the bottom and shell of the tank are accompanied by bending stresses in bottom plates. In the case of the B-type foundation and complete loosening of the soil on a certain width a and in the immediate vicinity of the concrete foundation ( Fig. 8 ), the highest stresses occur at the point no. 2 on the inner edge of the ring foundation, which is also to be found in [ 5 ]. In the case under consideration

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Water Main Failure Risk Assesment / OCENA RYZYKA AWARII MAGISTRALI WODOCIĄGOWEJ

Abstract

Town of Krosno is supplied with water by 3 intakes: Sieniawa, Iskrzynia and Szczepańcowa. After the treatment water flows in water mains to the water network in Krosno. The aim of his paper is qualitative risk analysis of the water main Sieniawa failures. The consequences of the failure: pressure value in the network and its duration, were described for different conditions of failures: time of failure, water demand and water storage tanks initial filling. For simulations of pipe failure water network model made in Epanet 2 program was used. The model was verified both during operation of water network and during the failure, where field data were used. The results of the simulations are corresponding to observations made during the real failures. Negative consequences appear only after emptying the water storage tanks, it results from two features of the storage tanks: they stabilize pressure in the network and for some time can provide water to the network. The time of emptying the storage tanks varies according to water demand their initial filling, it is at least 3 hours. During this time the are no sign of failure. When the storage tanks are empty reduction of pressure an shortage of water are observed on prevailing area of Krosno.

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Interval-Valued Intuitionistic Fuzzy Failure Modes and Effect Analysis of the System Failure Risk Estimation

Abstract

Among the risk assessment methods, failure modes and effects analysis (FMEA) is a popular, widely used engineering technique in many areas. It can be used to identify and eliminate known or potential failure modes to enhance reliability and safety of complex systems. In practice, risk estimations encounter difficulties connected with shortage of data. In such cases, we have to rely on subjective estimations made by persons with practical knowledge in the field of interest, i.e. experts. However, in some realistic situations, the decision makers might be unable to assign the exact values to the evaluation judgments due to his/her limited knowledge. In other words, there is a certain degree of hesitancy in human cognition and his/her judgment, who may have insufficient knowledge of the problem domain or uncertainty in assigning the evaluation values to the objects considered. In order to deal with ambiguity and uncertainty in the imperfect information, there have been recently proposed many various such theories as fuzzy sets, interval-valued fuzzy sets, type-2 fuzzy sets, hesitant sets, grey sets, rough sets and intuitionistic fuzzy sets. They have drawn more and more attention of scholars and been adopted in many applications This article addresses the Atanassov’s interval-valued intuitionistic fuzzy sets and FMEA methods in the risk estimation of the system failures based on the expert judgments.

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Interdependence Between Atrial Fibrilation and Heart Failure

Abstract

Atrial fibrillation (AF) is the most common rhythm disorder worldwide, becoming epidemic. Heart failure (HF) is a life-threatening disease and addressing it should be a priority. In this paper, we analyse recent progress on the relationship between HF and AF. The interdependence between AF and HF has not been elucidated and therefore remains an area of interest for research. It is estimated that both the incidence of AF and HF will increase significantly in the next decades worldwide, there will be a significant problem for health systems in several countries. It remains imperative to urgently promote additional research on epidemiology, mechanisms and treatment of AF and HF.

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Bayesian Inference in the Analysis of the Failure Risk of the Water Supply Network

Abstract

One of the basic subsystems of the collective water supply system is the water distribution subsystem which has a direct impact on the reliability and safety of water supply to consumers. Failures of water pipes may cause water losses (leaks), interruptions in the water supply to consumers and can be the cause of secondary water pollution in the water supply network. It was proposed to use Bayesian inference to locate failures on the water supply network and to determine a posteriori probability of water network failure. It was found that the conditional probability of distribution water supply network failure is definitely higher than the conditional probability of home connections failure. The research results should be used by the water supply company during the development of an operational strategy for the renovation and modernization of the water supply network.

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Survey on Road-Tyre Contact Patch Pattern and Wear Related Aspects

Abstract

Motor vehicle end-users approaches to tyre safety issues in automobiles translate to a number of tyre failure risk factors. This study basically assessed tread wear pattern of tyres in passenger cars used on Nigeria roads. The result obtained showed that 75.4% of the assessed tyres showed uneven wear pattern resulting from incorrect tyre-road contact effects. This observed high proportion of uneven tyre tread wear pattern implies high rate of inconsequential regard for tyre safety.

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Application of TRIZ Methodology in Diffusion Welding System Optimization

Abstract

Welding is tremendously used in metal joining processes in the manufacturing process. In recent years, diffusion welding method has significantly increased the quality of a weld. Nevertheless, diffusion welding has some extent short research and application progress. Therefore, diffusion welding has a lack of relevant information, concerned with the joining of thick and thin materials with or without interlayers, on welding design such as fixture, parameters selection and integrated design. This article intends to combine innovative methods in the application of diffusion welding design. This will help to decrease trial and error or failure risks in the welding process being guided by the theory of inventive problem solving (TRIZ) design method. This article hopes to provide welding design personnel with innovative design ideas under research and for practical application.

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Fault Tree Analysis as a Tool to Increase the Level of Security in an Enterprise

Abstract

Technological progress, as well as the development of the sciences on occupational health and safety, increased safety and improved working conditions in enterprises of even the most onerous industries. To maintain the required level of safety, preventive actions are taken to identify all hazards in the workplace. In practice, many methods are used to identify hazards depending on the type of technological processes and the types of workstations analyzed. The article presents the advantages of the fault tree analysis method as a tool to support the process safety management in the enterprise. The article presents features of the fault tree analysis method as a tool for better security management in an enterprise. Cause and effect relationships between events in the fault tree schema on selected examples were examined. Indirect and direct causes of accidents and failures in the enterprise have been identified, including human errors (human factor). The use of the fault tree analysis method to support accident and failure risk assessment in an industrial plant was also analyzed.

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Preventive Maintenance with Imperfect Repairs of a System with Redundant Objects

Preventive Maintenance with Imperfect Repairs of a System with Redundant Objects

An object ability to realise tasks may be restored by repairing only failed components. This is called imperfect repair, as the object is not as good as new after such a repair. Preventive replacement is an example of imperfect repair as well. The advantage of such maintenance is that it enables controlling a reliability level of a system. Sets of objects' components that should be replaced are derived on a basis of statistical diagnosing with use of data about components failures. The acceptable level of a failure risk while executing transportation tasks has been taken as a criterion of choosing elements to be replaced. An algorithm of selecting components for preventive replacement has been developed. It was shown that a level of system reliability could be controlled by changing an order of a quintile function in coordination and a number of redundant objects. A computer simulation model of the system was used to illustrate derived dependencies.

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