Supply Failure Research Articles

Predictive risks assessment of power supply interruption to oil production consumers, taking into account changes in significant factors

THE GOAL. To develop a decision-making procedure for the commissioning of equipment in the power supply system of oil production facilities in accordance with the minimum risk criterion. To substantiate the effectiveness of its practical application in the tasks of equipment repair management with the "technical condition" strategy based on a risk-oriented approach.METHODS. When solving the tasks, the following methods were used: the flowchart method for calculating the structural reliability indicators of the distribution electrical network with changes in its operational composition and technical condition of elements (equipment), the method for predicting the risks of power supply disruption in the circuit of each technological consumer, taking into account the possibility of reserving and imposing emergency recovery of the main element on the planned repair of the backup, scenario approach for determining scenarios for changing the risk of power supply failures when the operating state of the electrical network circuit changes.RESULTS. As a result of solving the problems, the values of the structural reliability indicators of the studied distribution electrical network are calculated under the most likely scenarios of changes in its operational composition and technical condition of equipment, the features of the integrated assessment of the technical condition of objects of voltage class 6 kV in their operating conditions are considered. The functions of forecasting the probabilities of power supply failures of oil production facilities are obtained depending on the integral assessment of their technical condition, which, along with the severity of the consequences of failures, make it possible to predict risks.CONCLUSION. A computational procedure has been developed that includes mathematical models and an algorithm for prioritizing equipment with a strategy "according to technical condition" when putting it into repair based on a forecast of the risks of power supply disruption to consumers. On a concrete example, the verification of calculation models and algorithm was carried out, the effectiveness of the developed computational procedure and its applicability in solving practical problems of managing repairs of electrical equipment of oil production facilities based on a risk-oriented approach was shown.

Solving the SME finance puzzle: an examination of demand and supply failure in the UK

ABSTRACT Following economic instability after the Global Financial Crisis, the financing of small and medium-sized enterprise (SME) growth and productivity has become central to UK government policy for sustainable economic development, evidenced by the establishment of the British Business Bank and Regional Investment Funds. This paper considers demand-side and supply-side failures in the contemporary UK SME finance market. Adopting mixed methods, binary logit regression analysis of the 2015 UK Small Business Survey of 15,502 SMEs is sense-checked using qualitative participatory findings from 6 SME finance support advisors. Findings confirm the importance of SME size, age, management capability and use of appropriate, timely external advice. They support the resource-based view of SME access to finance, contributing to borrower discouragement and under investment, suggesting the need for improved support to upskill entrepreneurs’ financial management and investment readiness and the concept of an ‘holistic entrepreneurial finance ecosystem’ approach to assist UK SME finance.

Resilience Enhancement of an Urban Microgrid during Off-Grid Mode Operation Using Critical Load Indicators

Microgrids (MGs) can be used as a solution to ensure resilience against power supply failures in electricity grids caused by extreme weather conditions, unavailability of generation capacities, and problems with transmission components. The literature is rich in research focusing on strengthening the planning of microgrids based on overall load demand. In this study, a critical load demand indicator will be calculated and used to identify optimum operation strategies of microgrids in a power failure mode. An urban microgrid with a large educational building is selected for the case study. Operation dispatch scenarios are developed to reinforce the system’s resiliency in severe conditions. A mixed-integer linear programming (MILP) approach is employed to identify global optimum dispatch solutions based on a next 48 h plan for different seasons to formulate a whole-year operational model. The results show that the loss of power supply probability (LPSP), as an indicator of resiliency, could be lowered to near zero while minimizing operational cost.

Laboratory Research on Hydraulic Losses on SHP Inlet Channel Trash Racks

There is currently a growing trend towards renewable energy sources, which are characterised by a guaranteed power supply and low failure rate. Hydropower plants (small or large) are an example of such a source. They supply a total of 16% of the world’s electricity. The advantages of a small hydropower plant include the relatively simple construction process and the lack of need for upstream water storage. SHPs are one of the most cost-effective and environmentally friendly energy technologies, which is why they are steadily increasing in popularity. One of the important components of SHPs are the trash racks in the inlet channels. Their main purpose is to catch debris and other elements carried downstream and to prevent these pollutants from reaching the turbine units. They can also protect migrating ichthyofauna such as larger fish. If trash racks are installed in the inlet channel, hydraulic losses are to be expected due to the reduction in the flow cross-section through the racks (bars) themselves and through the accumulation of debris and various types of trash on these racks. Energy losses on the trash racks affect the financial aspect of SHP investments. This paper presents the results of laboratory tests on trash racks for SHPs by taking into account the different shapes of the bars used, their number and spacing, and the angles of the trash racks to estimate the hydraulic losses on the trash racks. The measured values of hydraulic losses Δh on the trash racks varied according to the type of trash racks, the density of the bars in the cross-section, and the angle of the trash racks from the horizontal, reaching the highest values on the trash racks with angle bars (AB). They were almost eight times greater than those recorded on cylindrical-bar (CB) trash racks, although they involved different angles. It was shown that the discrepancy in the magnitude of losses on trash racks can be large, even for the same type of trash racks. It depends significantly on the design (shape and bar spacing) of the trash racks and the way the trash racks are installed. Depending on the inclination angle, the increase in energy losses reached 70% for angle bars, 60% for flat-bar trash racks, and almost 40% for cylindrical bars. The values of energy loss as well as the loss coefficient β varied non-linearly for the different bar types depending on the angle of inclination of the gratings, and the degree of this non-linearity depended on the type of bars and the blockage ratio of the section. The presented research results can be useful both during the design and the operation of an SHP.

Effects of axon branching and asymmetry between the branches on transport, mean age, and age density distributions of mitochondria in neurons: A computational study.

We report a computational study of mitochondria transport in a branched axon with two branches of different sizes. For comparison, we also investigate mitochondria transport in an axon with symmetric branches and in a straight (unbranched) axon. The interest in understanding mitochondria transport in branched axons is motivated by the large size of arbors of dopaminergic neurons, which die in Parkinson's disease. Since the failure of energy supply of multiple demand sites located in various axonal branches may be a possible reason for the death of these neurons, we were interested in investigating how branching affects mitochondria transport. Besides investigating mitochondria fluxes between the demand sites and mitochondria concentrations, we also studied how the mean age of mitochondria and mitochondria age densities depend on the distance from the soma. We established that if the axon splits into two branches of unequal length, the mean ages of mitochondria and age density distributions in the demand sites are affected by how the mitochondria flux splits at the branching junction (what portion of mitochondria enter the shorter branch and what portion enter the longer branch). However, if the axon splits into two branches of equal length, the mean ages and age densities of mitochondria are independent of how the mitochondria flux splits at the branching junction. This even holds for the case when all mitochondria enter one branch, which is equivalent to a straight axon. Because the mitochondrial membrane potential (which many researchers view as a proxy for mitochondrial health) decreases with mitochondria age, the independence of mitochondria age on whether the axon is symmetrically branched or straight (providing the two axons are of the same length), and on how the mitochondria flux splits at the branching junction, may explain how dopaminergic neurons can sustain very large arbors and still maintain mitochondrial health across branch extremities.

An unusual cause of oxygen failure in the anesthesia machine.

Dear Editor, A critical incident is being reported wherein a foreign body was detected in the oxygen pipeline inlet at the back of anesthesia workstation. The potentially catastrophic incident occurred during routine pre-use checkup of anesthesia workstation when there was no flow of oxygen on opening the flow control valve while pressure gauge on the pressure regulator of D-type oxygen cylinder was showing full pressure. The pressure gauge on the anesthesia machine was also showing no pressure. The oxygen cylinder and pressure regulator were changed but still there was no oxygen flow. It was then thought to change the connecting hose between cylinder and pipeline inlet at the machine end. As the NIST (non-interchangeable screw thread) connector was loosened from the machine end, an interesting finding was noticed, there was sudden movement of bobbin and oxygen flow started but soon the flow again ceased and the bobbin came back to the same position. Then again on opening the cylinder but keeping the connector at pipeline inlet slightly loosened led to the flow of oxygen and pressure gauge on the workstation also started showing pressure reading. Noticing this finding that loosening the NIST connector of the hose slightly from the pipeline inlet led to oxygen flow in the workstation led us to suspect a foreign body in the oxygen pipeline inlet of workstation. Subsequent careful search in the oxygen inlet led us to find a small black ring which was taken out with an 18 g needle as it was at the distal end of the inlet[Figure 1]. It was a small round rubber ring with a hole in the centre. Initially it was suspected it to be washer of the Bodock seal but closer inspection revealed it to be of different size.Figure 1: Foreign body in the oxygen inlet at the back of anesthesia machineNow the reason for absence of flow on tightening the connector was understood, probably because on tightening the rubber ring became flat and occluded the oxygen entry port of the inlet causing complete cessation of the oxygen flow. When the connector was slightly loosened, the central opening in the ring came back to its normal position thus allowing oxygen flow. The mechanism of entry of the foreign body at that unusual location could not be figured out since the same anesthesia machine has been in use for 4 years. The engineer of the manufacturer, Datex Ohmeda, was contacted and his viewpoint was that it could be a deliberate attempt by theatre personnel; however this could not be confirmed. The other possible explanation could be wear and tear of the ring that caused cessation of oxygen flow on being pressed tightly by metallic NIST connector[Figure 2].Figure 2: Worn out foreign body and NIST connectorThough there are many human errors and equipment malfunctions reported leading to oxygen supply failure[1], but such a presentation of a foreign body at the pipeline inlet has not been reported earlier. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

CCUS(Carbon Capture, Utilization and Storage) 부문의 국민경제적 파급효과 분석

CCUS(Carbon Capture, Utilization and Storage) is one of major methods to reduce greenhouse gas emission by Korean government. The government plans to invest and foster CCUS technology and industry through recently published national roadmap and strategy. Although CCUS is importance measure in Korean government’s Basic roadmap for Achieving the National Greenhouse Gas (GHG) Reduction Target, quantitative analysis such as market size, economic effects of CCUS industry has not been analysed in many research. Finally, this study try to analyze the economic effects of CCUS using 2019 input-output table published by Bank of Korea. The major results of this study are summarized as follows. First, production or investment in CCUS sector induces KRW 2.1510 of production and 0.8945 won of value-added. Moreover, the wage-inducing effect is estimated to be 0.4373 won, respectively. Second, production shortage cost from one won of supply failure in CCUS sector is calculated to be 1.4071 won, which is not small. Third, the impact of the 10% increase in CCUS on the general price level is computed to be 0.0186%, which is small. This information can be utilized in forecasting the economic effects of CCUS sector.

Potable Water Supply Deficiency in Yaounde (Centre Cameroon): Challenges and Coping Strategies of the Inhabitants

In most cities in developing countries, dwellers continue facing difficulties in adequately accessing potable water in sufficient quantity for their daily needs. These difficulties are perceived by households each time they fetch drinking water or try to get access to potable water for other household activities. This study aims to assess the problem of potable water supply in the Yaounde III Subdivisions’ neighbourhoods and the coping strategies developed by citizens to meet their needs. To achieve this objective, 300 households were selected and investigated based on purposive and systematic random sampling, particularly in the most densely populated neighbourhoods. We proceeded by identifying the different water supply sources of households for their various needs, and assessing the difficulties encountered in getting water and how they overcome them. Results reveal that in Yaounde III Subdivision only 34.33% of the households are supplied by the Cameroon Water Utilities Corporation (CAMWATER), while 65.67% rely on alternative water supply sources (wells, drillings and springs) without any pre-treatment. Among those connected to CAMWATER network, 46.6% do not have a regular water flow. Results also revealed that water sources were located at reasonable distances (less than 1 kilometre) and that 70% of households take less than 30 minutes to fetch water. Failure in water supply is mainly caused by the insufficient pumping capacity of the existing potable water treatment plants which lead to rationing and shortages, but also to rapid population growth and city extension not followed by the extension of the potable water distribution network. To fill the gap in water supply, it is imperative for public authorities to quickly achieve the project on water supply from the Sanaga River. Also, CAMWATER should extend its distribution network and improve its maintenance system.

Actuator failure compensation-based command filtered control of electro-hydraulic system with position constraint

In this article, the design and experimental evaluation of a fault-tolerant controller are introduced for a double-rod electro-hydraulic actuator subjected to actuator faults and disturbances. The internal leakage fault is captured as a bias fault, whilst the faults in servo-valve and supply failure are considered as a partial loss of effectiveness (LOE) fault. The design obstacles caused by the disturbances and bias fault are suppressed by nonlinear disturbance observers (NDO) while an asymmetric barrier Lyapunov function is used to ensure the non-violated boundary of the output position. To tackle the LOE fault, the development of an enhanced adaptive compensation technique for actuator fault-tolerant control (FTC) is then constructed. Moreover, to mitigate the “explosion of complexity” in the traditional backstepping design, the command-filtered control is utilized to elaborate the FTC scheme. It is shown by theoretical analysis that system stability is ensured under faulty conditions. Finally, simulation/experiment results and comparison studies are performed to further verify the effectiveness of the proposed approach.

Assessing the Current Alterations to the Estuarine Ecosystem in Southwest Nigeria

The estuarine ecosystem provides services that are economically and ecologically indispensable, and these services offer support to human well-being. However, uncontrolled human activities have altered the ecosystem goods and services provision, thus resulting in numerous irreversible ecological losses in the wetlands. Globally, studies have used many approaches and paradigms to manage estuarine ecosystems, yet a limited management mechanism exists in the Nigerian estuarine ecosystems. This study investigated the human dimensions of the alterations of the estuarine ecosystems in Southwest Nigeria over 20 years and used the result to inform decision-making. This study also used remotely sensed datasets (Operational Land Imager and Thermal Infrared (OLI/TIRS) and Enhance Thematic Mapper (ETM)) from the United State Geological Survey (USGS) Earth Explorer as references to determine the estuarine ecosystems coverage and loss. The reference datasets were combined and overlaid on the Nigerian wetland data to conduct a change analysis. Maximum Likelihood Classification in ArcGIS was conducted to determine the ecosystem coverage and loss. The study also conducted a qualitative assessment of the concerned management agencies to understand the questions of the environmental, ethical, governance, economics, decision making and policy implementation that shape estuarine ecosystems management in the study area. The result of this study indicates that 6405 hectares (38.1%) of the estuarine coverage in 2001 has been depleted in 2021, and management activities are traditional, nonsequential, and deficient. The drivers of alterations identified are mainly anthropogenic activities and climate change. The implications include loss of valuable fish species, pollution, habitats and biodiversity loss. Therefore, this study recommended the Ecosystem-Based Management approach to determine all essentials of the success or failure of ecosystem goods and services supply, resource use efficiency, and stability of estuarine ecosystems in Southwest Nigeria.

Financial sustainability of rural water supply: An analysis of cost recovery, revenue collection, and efficiency

AbstractMaintaining a financial sustainable pipe water supply (PWS) is one of the serious challenges in sustainable provision of water supply in rural areas. Poor revenue collection and willingness to pay for the service is adding severity to the problem. This study analyses the factors affecting revenue collection in rural water utilities and measures its efficiency in maximizing revenue and average hour of water supply per day. The findings convey that cost recovery is a failure in rural water supply even they are not able to generate revenue. Inactive community participation, the notion of free water supply, unaccountable payment is main reason for poor revenue collection. Therefore, active community participations, educating the household on water supply, adoption of accountable payment mode will be a step towards revenue generation. To attain efficiency, the utilities can expand their output revenue and hours of water supply by 22% without altering their input. This study is an empirical contribution in the field of sustainable provision of water supplies, which address the problem of poor revenue generation in rural water supply and find out the reason for it.

Contributions of Electricity and Gas Sub-Sector to Economic Growth in Nigeria: A Linear Approach

Industrial policies were developed to stimulate and provide opportunities for prospering industrial activities following the decline of investment in the agricultural sector. This followed the discovery of crude oil in Nigeria. Electricity, gas, steam and air-conditioner, an industrial sub-sector is very crucial and requisite channel for industrial development, whether for automated, machines services or computer manufacturing processes. Failure in energy and power supply, as well as gas flaring remains a fundamental problem in Nigeria’s development. This study examined the impact of electricity and gas sub-sector of industrial sector on economic growth in Nigeria using data from 1980 to 2020. Vector error correction mechanism was used to determine the impact of the independent variables on the dependent variable. In the short run, our study shows the existence of positive, non-significant impact of electricity and gas output on economic growth. However, in the long run there was positive significant impact of electricity and gas output on economic growth in Nigeria within the period of study. The implication of the result is that adequate production and utilization of electricity and gas will spur economic activities that will generate economies of scale; since every component of the economy (industry, urbanization, modernized farming, etc) extensively demand for electricity and gas. Also, efficiency of electricity and gas would reduce energy bills for poor households, helps the nation to tackle greenhouse gas emissions. The continues gas flaring and consistent power cut in electricity in Nigeria affected industrial sector in Nigeria. This study showed that there is positive significant impact of electricity and gas on economic growth if there is intentional implementation of power policy with conscious disciplinary actions to control defaulters and make substantial investment that would stimulate industrial activities to spur economic growth.

Development of a pump-ejector system for SWAG injection into reservoir using associated petroleum gas from the annulus space of production wells

Implementation of SWAG technology by means of water-gas mixtures is a promising method of enhanced oil recovery. The use of associated petroleum gas as a gas component in the water-gas mixture allows to significantly reduce the amount of irrationally consumed gas and carbon footprint. Relevant task is to choose a simple, reliable and convenient equipment that can operate under rapidly changing operating conditions. Such equipment are pump-ejector systems. In order to create water-gas mixture it is proposed to use associated gas from the annulus space. This solution will reduce the pressure in the annulus space of the production well, prevent supply disruption and failure of well equipment. The paper presents a principal technological scheme of the pump-ejector system, taking into account the withdrawal of gas from the annulus space of several production wells. The layout of the proposed system enables more efficient implementation of the proposed technology, which expands the area of its application. Experimental investigations of pressure and energy characteristics of the ejector have been carried out. Analysis of the obtained data showed that it was possible to increase the value of maximum efficiency. The possibility of adapting the system in a wide range of changes in operating parameters has been established. Recommendations on selection of a booster pump depending on the values of working pressure and gas content are given.

Distributed Generation Photovoltaic System Based on Fuzzy Logic

Abstract: Most of the Developing Countries in the world have facing the demand of unavoidable power demand. Due to this high demand, we facing the high-power losses and increase of the transmission lines. In our India we are totally based on the thermal & nuclear power plant and it’s also going to end in few Years. The continues power demand can cause reduction of the voltage levels and affect the system stability, that causes the failure in power system Network and make the transmission line in the stressed condition. In the current situation we going towards the renewable energy, and it’s gaining the attention around the globe. The renewable energy matches the load demand and full-fill it according to the load demand. To step in renewable energy, we have to study it carefully to avoid any unwanted issues occurs in the system and do not make it unstable. The main issue that faces by the consumers is, the solar system gets off during the main supply failure and the total load shifted on the Diesel generator. Due to this Diesel generator get more consumption of diesel and get heavily loaded. To avoid this Heavy load on Diesel Generator we have to use the solar plant during off-grid conditions with the help of smart synchronization between the photovoltaic system and Diesel Generator. Thus, the result of smart synchronization of Photovoltaic system and diesel generation, we get the less load on Diesel generator as compare to the photovoltaic system.

What diggers drank: the AIF and its refreshments 1914–18

Alcohol consumption has dominated the very limited discussion of the AIF’s liquid intake, but there has been no study of the totality of the role of various beverages in the health and well-being of the diggers. This article explores the physical and cultural context of all beverages consumed by the AIF, noting the successes and failures of official army supply. This article reveals that alcohol, while dominating contemporary accounts of the AIF and prevailing ideas about digger identity, was actually subject to contests over its utility and legitimacy, in part due to the influence of the temperance movement. Meanwhile, non-alcoholic beverages such as tea, water, cocoa and coffee made far more important contributions to the physical and emotional well-being of soldiers than previously recognised, and have been routinely overlooked in scholarly and popular accounts of the AIF.

Assessment of the operation safety margin of the HL-LHC superconducting recombination Dipole D2 in case of helium filling failure

After the successful completion of the cryogenic performance tests of the He II heat exchanger prototype for the D2 recombination dipole of the future HL-LHC project at CERN, specific measurements were performed to determine the operation safety margin in case of abnormal operating conditions. This is particularly relevant in case of the failure of liquid helium supply in the He II cold source. For nominal operation, the liquid level is regulated at a constant value and it is not necessary to know its value very accurately. However, in case of a partial drying of the heat exchanger due to discontinuation of the helium liquid supply, it is essential to monitor the absolute value of the liquid level to anticipate any cooling malfunction. This paper describes the procedure for an accurate in-situ He II level measurement as well as for the heat loss and mass flow rate estimates in a He II phase separator. The operation safety margins of the He II heat exchanger prototype for the D2 magnet are then analyzed for the different operating conditions considered during the HL-LHC runs in case of non-nominal liquid level in the He II cold source.

Method of Planning Repairs of the Installation including Building Waste

Repairs of water supply, sewage and central heating installations in residential buildings should be carried out systematically. However, very often, renovation dates are postponed, which results in installation failures. The failures of water supply, sewage and central heating installations, due to the currently used methods of masking them and running them as under-plaster and under-floor installations, are always connected with the damage and necessity of reconstruction of the building elements. As a result, renovation work has to be carried out to a greater extent and the amount of construction waste is much greater. The analysis of different renovation strategies of water supply, sewage and central heating systems in residential buildings made in traditional technology has been carried out. The article presents the results of the research on the effects of the postponement of the renovation works on the changes in the technical condition of the building and on the scope of renovation works. The aim of the research is to develop a method for planning repairs of the installation taking into account optimization of the amount of construction waste. The aim of the research is also to answer the question: To what extent does the postponed repair of water and sewage installations influence the amount of construction waste? In the proposed method, the Prediction of Reliability according to Rayleigh Distribution (PRRD) model is used. The results of the research indicate the necessity of conducting the renovation works of the installation in a timely manner due to the increasing amount of construction waste and the introduced reduction of its amount with the increase of the recycling rate.

Set of Suffosion Holes Occurring After a Water Supply Failure as a Structure with Fractal Features

Set of Suffosion Holes Occurring After a Water Supply Failure as a Structure with Fractal Features

A systems-theoretic hazard analysis for safety-critical medical gas pipeline and oxygen supply systems

Medical gas systems are safety-critical systems due to their association with critical care situations. In particular, the oxygen gas supply system contains many complications represented in the interactions between human and equipment while operating the system and managing emergencies. Therefore, it contains many hazards that require high safety standards to maintain the integrity of the system. The traditional hazard analysis methods suffer from weaknesses as their linear reasoning assumption cannot adequately describe the actual behavior of modern socio-technical systems that are characterized by tight couplings and complex interactions among technical, human and organizational aspects. Alternatively, Systems Theoretical Process Analysis (STPA) is a new hazard analysis approach that accounts for the causal relationships between system components and their unsafe interactions, allowing the integration of both occupational and process safety. STPA is widely used in the automotive, aviation, and aerospace industries whereas there are a few applications of STPA in healthcare domain. This paper proposes the use of STPA methodology in analyzing the hazards related to the medical gas pipeline and oxygen supply systems in a low-medium income country. Specifically, the analysis considers the emergencies that stem from the total or partial failure of oxygen supply and the hazards related to temporary restoration of the medical oxygen system. The results indicate that STPA contributes to identifying the hazards resulting from the interference between the human, machines, and equipment, and studying the unsafe effect of the system elements on each other. This research suggests control measures to prevent the unsafe interaction of the system components and improve the response time to oxygen failure incidents, which greatly reduces the potential consequences.

Reasons of Engagement and Impact of Contract Farming to Smallhold Farmers: A Literature Review

This paper is a review of books, journals, discussion papers, conference proceedings, and other related articles about the reason or reasons of the smallhold farmers in engaging in contract farming and evaluate its tangible and intangible impact to their socio-economic conditions. The literatures show that contracting generates more benefits and better income to farmers, especially the marginal and smallholders. It improves their productivity due to risk minimization, access to market and economies of scale. This means the farmers get effectively integrated into domestic and international markets. Contracting also gives farmers intangible and latent benefits. However, contract farming may pose the following problems like: contract biases, imperfections of the market world, input supply and crop failures, delayed produce delivery and payment, quality control and lack of negotiation power. However, the following gaps must be focused in the future studies: an in-depth evaluation on the outcomes of contract farming to rural development; accountable marketing contracts between small farmers and big firms; a systematic investigation on informal contracts and how it can be an efficient and effective market linkage for the smallholders; and, more empirical studies on contract farming in livestock and crop farming in the developing countries especially the Philippines.