To see the other types of publications on this topic, follow the link: Leakage assessment methodology.
Journal articles on the topic 'Leakage assessment methodology'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Leakage assessment methodology.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Schneider, Tobias, and Amir Moradi. "Leakage assessment methodology." Journal of Cryptographic Engineering 6, no. 2 (February 12, 2016): 85–99. http://dx.doi.org/10.1007/s13389-016-0120-y.
Full text
2
Pietrucha-Urbanik, Katarzyna, Barbara Tchórzewska-Cieślak, and Mohamed Eid. "Water Network-Failure Data Assessment." Energies 13, no. 11 (June 10, 2020): 2990. http://dx.doi.org/10.3390/en13112990.
Full textAbstract:
The water-supply system is one of the basic and most important critical infrastructures. Water supply service disruption (water quality or quantity) may have serious consequences in modern societies. Water supply service is subject to various failure modes. Failure modes are specified by their degradation mechanisms, criticality, occurrence frequency and intensity. These failure modes have a random nature that impacts on the network disruption indicators, such as disruption frequency, network downtime, network repair time and network back-to-service time, i.e., the network resilience. This paper focuses on the water leakage failure mode. The water leakage failure mode assessment considers the unavoidable annual real water losses and the infrastructure leakage index recommended by the International Water Association’s Water Loss Task Force specialist group. Probabilistic statistical modelling was implemented to assess the seasonal index, the failure rates and the expectation value of the “mean time between failures.” The assessment is based on real operational data of the network. Specific attention is paid to the sensitivity of failures to seasonal variations. The presented methodology of the analysis of the water leakage failure mode is extendable to other failure modes and can help in developing new strategies in the management of the water-supply system in normal operation and crisis situations.
3
Wang, Xiaojia, Xianli Liu, Zhaoyang Jin, Jiewen Zhu, and Baosheng Jin. "Theoretical Methodology of a High-Flux Coal-Direct Chemical Looping Combustion System." Processes 6, no. 12 (December 4, 2018): 251. http://dx.doi.org/10.3390/pr6120251.
Full textAbstract:
This study, as an extension of our previous experimental tests, presented a mechanism analysis of air reactor (AR) coupling in a high-flux coal-direct chemical looping combustion (CDCLC) system and provided a theoretical methodology to the system optimal design with favorable operation stability and low gas leakages. Firstly, it exhibited the dipleg flow diagrams of the CDCLC system and concluded the feasible gas–solid flow states for solid circulation and gas leakage control. On this basis, the semi-theoretical formulas of gas leakages were proposed to predict the optimal regions of the pressure gradients of the AR. Meanwhile, an empirical formula of critical sealing was also developed to identify the advent of circulation collapse so as to ensure the operation stability of the whole system. Furthermore, the theoretical methodology was applied in the condition design of the cold system. The favorable gas–solid flow behaviors together with the good control of gas leakages demonstrated the feasibility of the theoretical methodology. Finally, the theoretical methodology was adopted to carry out a capability assessment of the high-flux CDCLC system under a hot state in terms of the restraint of gas leakages and the stability of solid circulation.
4
Campbell, Enrique, Amilkar Illaya-Ayza, Joaquín Izquierdo, Rafael Pérez-García, and Idel Montalvo. "Social-network-based water supply network sectorization methodology using monte carlo simulation to predict economical and operational benefits." Acta Universitaria 26 (March 3, 2017): 44–53. http://dx.doi.org/10.15174/au.2016.1060.
Full textAbstract:
Water Supply Network (WSN) sectorization is a broadly known technique aimed at enhancing water supply management. In general, existing methodologies for sectorization of WSNs are limited to assessment of the impact of its implementation over reduction of background leakage, underestimating increased capacity to detect new leakage events and undermining appropriate investment substantiation. In this work, we raise this issue and put in place a methodology to optimize sectors' design. To this end, we carry out a novel combination of the Short Run Economic Leakage Level concept (SRELL- corresponding to leakage level that can occur in a WSN in a certain period of time and whose reparation would be more costly than the benefits that can be obtained). With a non-deterministic optimization method based on Genetic Algorithms (GAs) in combination with Monte Carlo simulation. As an example of application, methodology is implemented over a 246 km pipe-long WSN, reporting 72 397 $/year as net profit.
5
Pérez, R., S. de las Heras, J. Aguilar, J. Pascual, A. Peralta, and E. Landeros. "District management areas characterisation in water network based on clustering." Water Supply 9, no. 5 (December 1, 2009): 591–600. http://dx.doi.org/10.2166/ws.2009.633.
Full textAbstract:
The division of a network in different sectors is a usual practice in Water Companies. It improves the management of the network in different senses. Sectors have more homogenous characteristics and need specific cares and treatments that is not the same all through the network. Specifically for leakage detection and assessment it is interesting to know the performance of the sector before any leakage detection strategy is applied. In this paper a characterisation methodology for the sectors is presented. This methodology is based on the knowledge provided by the company but has been analysed using clustering techniques. The main objective of the classification was to give a scope of the different types of sectors present in the network. A decision table based on the relevant descriptors was built. This allowed choosing three interesting pilot sectors for the leakage detection methodology study.
6
Rogozin, E. A., D. G. Silka, and O. A. Gulyaev. "METHODOLOGY FOR ASSESSING THE SECURITY OF INFORMATION PASSED THROUGH THE TECHNICAL CHANNELS OF A SPECIAL-PURPOSE INFORMATISATION OBJECT." Herald of Dagestan State Technical University. Technical Sciences 46, no. 4 (January 2, 2020): 123–33. http://dx.doi.org/10.21822/2073-6185-2019-46-4-123-133.
Full textAbstract:
Objectives. In order to determine the security of a special-purpose informatisation object, it is necessary to calculate the effectiveness indicators of information security (IS) measures aimed at preventing unauthorised access (UA) threats associated with information leakage through technical (acoustic) channels. In order to determine the actual channels of information leakage, it is necessary to develop a list of actions to neutralise potential threats, including the development of an information protection system for a special-purpose informatisation object.Method. A security assessment of the special-purpose informatisation object is carried out using expert documentary and instrumental methods.Results. The results of evaluating the indicators of protection against information leakage through the air (acoustic) channel are presented and aspects of improving special measures for protecting information at the special-purpose informatisation object are identified.Conclusion. Due to its relevance, the direction of this study requires further development of organisational and technical measures to implement the requirements of regulatory documents on the protection of information in special-purpose informatisation objects.
7
Kozlov, A., and N. Noga. "About Some Risks Associated with Subjective Factors, and the Methodology for their Assessment." Review of Business and Economics Studies 9, no. 3 (November 22, 2021): 94–102. http://dx.doi.org/10.26794/2308-944x-2021-9-3-94-102.
Full textAbstract:
The authors propose a methodology for assessing the risk associated with subjective factors that may affect the achievement of the final goals of business projects, including ensuring information security. Such factors may include the level of salary, the level of professionalism, and others. At the same time, we propose carrying out the risk assessment by using the fuzzy logic method, which allows us to determine the dependence of the risk on various parameters under conditions of their uncertainty. According to the authors, the proposed methodology will help avoid some incorrect management decisions in the formation of author (working) teams, which could lead to negative consequences in the further implementation of the business project. These negative consequences can be expressed in delaying the implementation period, increasing the project’s cost, or even losing business due to critical information and personnel leakage. Also, this method allows you to increase the effectiveness of personnel policy in the organisation or the company. We noted that this method is applicable not only for individual enterprises but also for corporations and associations with complex network structures.
8
Xiao, Ting, Brian McPherson, Richard Esser, Wei Jia, Zhenxue Dai, Shaoping Chu, Feng Pan, and Hari Viswanathan. "Chemical Impacts of Potential CO2 and Brine Leakage on Groundwater Quality with Quantitative Risk Assessment: A Case Study of the Farnsworth Unit." Energies 13, no. 24 (December 14, 2020): 6574. http://dx.doi.org/10.3390/en13246574.
Full textAbstract:
Potential leakage of reservoir fluids is considered a key risk factor for geologic CO2 sequestration (GCS), with concerns of their chemical impacts on the quality of overlying underground sources of drinking water (USDWs). Effective risk assessment provides useful information to guide GCS activities for protecting USDWs. In this study, we present a quantified risk assessment case study of an active commercial-scale CO2-enhanced oil recovery (CO2-EOR) and sequestration field, the Farnsworth Unit (FWU). Specific objectives of this study include: (1) to quantify potential risks of CO2 and brine leakage to the overlying USDW quality with response surface methodology (RSM); and (2) to identify water chemistry indicators for early detection criteria. Results suggest that trace metals (e.g., arsenic and selenium) are less likely to become a risk due to their adsorption onto clay minerals; no-impact thresholds based on site monitoring data could be a preferable reference for early groundwater quality evaluation; and pH is suggested as an indicator for early detection of a leakage. This study may provide quantitative insight for monitoring strategies on GCS sites to enhance the safety of long-term CO2 sequestration.
9
McKenzie, R., and C. Seago. "Assessment of real losses in potable water distribution systems: some recent developments." Water Supply 5, no. 1 (March 1, 2005): 33–40. http://dx.doi.org/10.2166/ws.2005.0005.
Full textAbstract:
Considerable progress has been made over the past 10 years in the assessment and benchmarking of real losses in potable water distribution systems. Most of the advances have been based on the burst and background estimate (BABE) methodology, which was first developed in the mid-1990s by the UK water industry and has since been widely accepted and used in many parts of the world. Since the original BABE methodology was developed, several other key concepts have been added to the evergrowing list of water demand management tools. In particular, the infrastructure leakage index (ILI) and unavoidable annual real losses (UARL) introduced by A. Lambert, and the fixed area variable area discharge (FAVAD) theory by J. May, are now recognised as key “tools of the trade” in any water demand management assessment. One of the first main developments where the above-mentioned concepts were applied in practice to benchmark leakage was in South Africa, where the local Water Research Commission supported the production of the BENCHLEAK Model. This was basically the first comprehensive model to assess real losses in potable water distribution systems using the UARL and ILI concepts. The model was developed by one of the authors together with A. Lambert, and was soon followed by similar developments in Australia (BENCHLOSS) and New Zealand (BENCHLOSSNZ). Both models incorporated additions and enhancements to the original South African model, and were tailored to suit the local conditions in line with the clients' requirements. Similar developments took place in parallel by various leakage specialists, most notably in Brazil, Malaysia and Cyprus, to mention just a few of the similar initiatives. Each time a new model was developed, certain improvements were made and the “science” of leakage management and benchmarking was enhanced. Through the use of the different models and from discussions with various researchers from around the world, it has become clear that there is a genuine need for such models, and they are being readily accepted by clients in most areas. The discussions have also raised many questions concerning the derivation of the terms used to calculate the UARL and the ILI, and, to address these concerns a specialist group was created through the IWA to investigate the various issues. This paper will highlight the progress that has been made to date with regard to the key issues that have been raised by the task-team members, and recommendations based on the feedback that has been received from around the world. The paper will also present some of the results that have been obtained from different parts of the world to highlight both the progress and the problems associated with the assessment of real losses. The paper will conclude with a short description of several new models that have been developed and are in use, which demonstrate the latest improvements to an ongoing process to assess and benchmark real losses in water distribution systems.
10
Andryianava, T. A., and S. B. Salomatin. "DLP: REDUCED RISK OF LEAKAGE OF CONFIDENTIAL INFORMATION OF THE BANK." «System analysis and applied information science», no. 3 (November 2, 2017): 76–82. http://dx.doi.org/10.21122/2309-4923-2017-3-76-82.
Full textAbstract:
Research application of DLP-system for protection of confidential information, a methodology for adapting the DLP-system to the specific activities of the organization, comparative analysis of the results of standard and adapted DLP-systems in the Bank. Developed: a technique for analyzing information security events, algorithm for responding to identified events, methodology and procedures for adapting the standard DLP-system to the specifics of the Bank’s activities. The methodology for adapting a standard DLP-system to the specifics of the Bank’s work consists of the following activities: identification of critical corporate information categories, audit of information systems, description of current risks and their assessment, introduction of rules for Bank’s critical information and setting up a DLP system in accordance with the specifics of the Bank’s work. Modernization of the configuration of a standard DLP-system includes the following procedures: selection of confidential information of the Bank based on membership criteria, setting up detection, creating perimeters and developing an algorithm for responding to identified information security events in the Bank. The algorithm is designed to improve the efficiency of the response of information security officers in cases of incident detection and describes the stages of the subsequent actions. The results of the research prove that using an adapted DLP-system significantly reduces the number of false positives, increasing the accuracy of detecting confidential information and reducing the risk of leakage of critical information outside the corporate network. The application of the adapted DLP-system in the Bank allowed to increase the speed of response of information security specialists to the information security events detected by the DLP-system adapted to the Bank, and also allowed the DLP-system to transition from the copy mode to the blocking mode of illegitimate transfer of information.
11
Hermansyah, Heri, Mohamad Nur Hidayat, Anggraini Kumaraningrum, Masafumi Yohda, and Azmi Shariff. "Assessment, Mitigation, and Control of Potential Gas Leakage in Existing Buildings Not Designed for Gas Installation in Indonesia." Energies 11, no. 11 (November 1, 2018): 2970. http://dx.doi.org/10.3390/en11112970.
Full textAbstract:
Operational activities of gas pipelines are associated with potential hazards and risks that can potentially lead to pipeline failure, including failure of the gas distribution pipeline in existing buildings. Unfortunately, few studies on risk analysis of the gas distribution pipeline in existing buildings have been published. Therefore, this study was conducted to provide a reference for analyzing the risk of pipeline leakage caused by small-scale leakage, large-scale gas release, and gas pipeline rupture in existing buildings in Indonesia not designed for gas installation. The study was performed using the event tree analysis method. The methodology of this study was initiated by identifying the scenario of the case of small-scale leakage, large-scale gas release, or gas pipeline rupture. Then, pivotal events were identified, an event tree diagram was constructed, the event failure of each pivotal event was determined, and the probability value of the outcome risk was calculated. The risk was evaluated in terms of fire, casualties, and gas released. The results of this study showed the highest risk in each scenario which can result in fire, severe casualties, and light poisoning. The highest risk in the small-scale leak scenario had a probability value of 1.5 × 10−3. In the large-scale gas release scenario, the highest risk had a probability value to incur a fireball, severe casualties, and light gas poisoning of 6.0 × 10−4. In the gas pipeline rupture scenario, the highest risk had a probability value of fireball, severe casualties, and light poisoning of 7.0 × 10−4. The probability value of each risk was reduced by the installation of a gas detector and water sprinkler as a barrier.
12
Лаврентьева, G. Lavrenteva, Каткова, M. Katkova, Сергулев, R. Sergulev, Астахова, and L. Astahova. "Radiation Risk for the Public in a Radioactive Waste Repository’s Zone of Influence." Safety in Technosphere 6, no. 1 (May 15, 2017): 38–42. http://dx.doi.org/10.12737/article_590199133d9ff3.23161219.
Full textAbstract:
An assessment for impact of a radioactive waste repository on a regional population according to “Safety Evaluation Methodology for Shallow Ground Repositories of Radioactive Waste” proposed by International Atomic Energy Agency (IAEA) has been performed. The following scenarios for ingress of radio-nuclides in the environment were taken into consideration: fluid leakage, dust resuspension, fire, flooding. Evaluation of exposure dose rate and radiation risk for the population had showed that the risk is unacceptable for emergency scenarios (dust resuspension, fire, flooding), as there is an irradiation dose overrunning for the public (1 mcSv/year), established by Radiation Safety Standards‑99/2009, and negligible risk level for the public, equal to 10–6. With the development of the “Leakage of Fluid” scenario the risk for one of the radio nuclides (137Cs), which are sources of public exposure, is acceptable. In connection with this the radioactive waste repository is “conditionally” safety object to the public while a gradual penetrating of radio nuclides into the environment.
13
Petersen, J., and J. G. Petrie. "Modelling heavy metal mobilisation in solid waste deposits - a predictive tool for environmental risk assessment." Water Science and Technology 39, no. 10-11 (May 1, 1999): 193–96. http://dx.doi.org/10.2166/wst.1999.0654.
Full textAbstract:
The release of heavy metal species from deposits of solid waste materials originating from minerals processing operations poses a serious environmental risk should such species migrate beyond the boundaries of the deposit into the surrounding environment. Legislation increasingly places the liability for wastes with the operators of the process that generates them. The costs for long-term monitoring and clean-up following a potential critical leakage have to be factored in the overall project plan from the outset. Thus assessment of the potential for a particular waste material to generate a harmful leachate is directly relevant for estimating the environmental risk associated with the planned disposal operation. A rigorous mechanistic model is proposed, which allows prediction of the time-dependent generation of a leachate from a solid mineral waste deposit. Model parameters are obtained from a suitably designed laboratory waste assessment methodology on a relatively small sample of the prospective waste material. The parameters are not specific to the laboratory environment in which they were obtained but are valid also for full-scale heap modelling. In this way the model, combined with the assessment methodology, becomes a powerful tool for meaningful assessment of the risks associated with solid waste disposal strategies.
14
Bloss, Richard. "Sensor technology, ever more important to packaging: a highlight at PackExpo." Sensor Review 32, no. 3 (June 22, 2012): 199–202. http://dx.doi.org/10.1108/02602281211233179.
Full textAbstract:
PurposeThe purpose of this paper is to review the PackExpo Show (packaging technology), with emphasis on the new sensor innovations and applications to packaging on display.Design/methodology/approachIn‐depth interviews with exhibitors of sensors of all types at the PackExpo Show.FindingsSensing in packaging once was just weighing it but now it is product inspection, quality assessment, leakage and much more.Practical implicationsPackaging customers now have sensor technologies available to address government regulation concerns, product quality and the traditional weight and size factors.Originality/valueSensor users will find information about the latest in new sensing technologies which may assist them in solving current production problems.
15
Antoine, Raphaël, Cyrille Fauchard, Yannick Fargier, and Edouard Durand. "Detection of Leakage Areas in an Earth Embankment from GPR Measurements and Permeability Logging." International Journal of Geophysics 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/610172.
Full textAbstract:
Ground penetrating radar (GPR) is a nondestructive method allowing the improvement of our knowledge of civil engineering structures. In particular, this method may be a nondestructive efficient tool for dike diagnosis and complete classical geotechnical methods. In this paper, we present GPR observations obtained on an earth embankment (crest and sloped paved revetment) in bad condition and located on the lateral canal of the Loire river (Saint Firmin, 80 km South East of Orléans). These measurements are combined with corings, visual inspection, and permeability logging performed with an updated drilling system, the Perméafor. This survey leads (i) to the detection of decompressed zones associated with leakage areas visible at the foot of the downstream slope and (ii) to the location of potentials voids underneath the paved revetment. This multidisciplinary approach complied with the dike inspection methodology proves its efficiency for the assessment of earth embankments.
16
Chae, Yooeun, Rongxue Cui, Jieun Lee, Lia Kim, and Youn-Joo An. "Development of Methodology for Vulnerability Assessment of Chemical Accident in Terrestrial Ecosystem:(1) Focusing on the Trees." Journal of Korean Society of Environmental Engineers 42, no. 5 (May 31, 2020): 229–38. http://dx.doi.org/10.4491/ksee.2020.42.5.229.
Full textAbstract:
Objective:With rapid industrial development, human and the environment are frequently exposed to various chemicals. In particular, there is a possibility that terrestrial ecosystems as well as humans are exposed to a large amount of highly toxic chemicals due to accidents occurring frequently in Korea and abroad. If a large amount of chemicals enter the terrestrial ecosystem due to an accident such as a chemical leakage, the terrestrial ecosystem around the accident site may be affected and these chemicals may impair not only a living organisms, but also the function of terrestrial environment, the habitat of the organisms. The aim of this study is to develop methodology for vulnerability assessment of chemical accident in terrestrial ecosystem.Method:First, we selected 41 forest tree species and 41 shrubs among woody plants according to the domestic distribution and establish various vulnerability indicators that can be evaluated according to the exposure and recovery categories.Results and Discussion:As a result of vulnerability scoring for 41 forest tree species and 41 shrubs, most vulnerable species were <i>Daphniphyllum macropodum, Lindera obtusiloba, Juniperus rigida, Diospyros lotus,</i> and <i>Eucommia ulmoides</i> in forest trees and <i>Zanthoxylum piperitum, Cephalotaxus koreana, Forsythia koreana, Cycas revoluta,</i> and <i>Lespedeza maximowiczii</i> in shrubs.Conclusions:This study quantified the vulnerability of trees to chemical accidents by adding them and assigning them according to their characteristics. We expect that the risk of chemicals caused by chemical accidents occurring in these days and the exposure of chemicals to the environment can be assessed in terms of ecological perspective using the assessment of vulnerability of terrestrial ecosystems proposed in this study.
17
Turnbull, Robert, Nader Dolatabadi, Ramin Rahmani, and Homer Rahnejat. "Energy loss and emissions of engine compression rings with cylinder deactivation." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 235, no. 7 (January 4, 2021): 1930–43. http://dx.doi.org/10.1177/0954407020982868.
Full textAbstract:
A novel integrated multi-physics assessment of the piston top compression ring of an internal combustion engine under normal operation mode, as well as subjected to cylinder deactivation is carried out. The methodology comprises ring-liner thermo-mixed hydrodynamics, elastodynamics of ring, as well as combustion gas blow-by and emissions. Therefore, the analysis provides prediction of ring-liner contact’s energy losses and gas power leakage across the piston and ring crevices, as well as the resulting emissions. Cylinder deactivation (CDA) technology reduces the unburnt fuel entering the ring-pack crevices, as well as the emissions. It is also shown that the frictional and gas leakage power losses are exacerbated under CDA by as much as 20%. Although this is much lower than the potential gains in fuel usage when using CDA. The optimisation of the piston compression ring would provide further fuel efficiency and improved emissions, an issue which has not hitherto received the attention which it deserves. The in-depth analysis has also shown that CDA reduces the predicted CO, NOx and HC emissions by nearly as much as 8.5%, 10% and 8.7%, respectively.
18
Suhariyanto, Tatbita, Dzuraidah Wahab, and Mohd Rahman. "Product Design Evaluation Using Life Cycle Assessment and Design for Assembly: A Case Study of a Water Leakage Alarm." Sustainability 10, no. 8 (August 9, 2018): 2821. http://dx.doi.org/10.3390/su10082821.
Full textAbstract:
This study proposed the use of an LCA supported by a design efficiency evaluation based on Design for Assembly principles to reduce the environmental impact of a product. To illustrate the methodology, a water leakage alarm (WLA) was selected as the object for a case study. Based on the identification and evaluation of the LCA results, it was inferred that the stage with the highest environmental impact was the manufacturing stage (75.35%), followed by the use stage (23.88%), the disposal of the WLA (0.64%), and finally, the disposal of the batteries (0.14%). For the manufacturing stage, the most interrelated categories were the hazardous waste and human toxicity, while the use stage was the main contributor to ozone depletion and acidification. Moreover, the disposal of the WLA and batteries contributed to the bulk waste. Furthermore, from the assembly evaluation, the design efficiency of the product was 14%. Two recommendations for improving the design of the WLA were: (1) to reduce the number of screws from three units to one unit, and (2) to eliminate the use of a cable and to replace it with a wireless component. By implementing both the proposed recommendations, the design efficiency was improved by as much as 34%. From the environmental perspective, there is not much difference between the wired alarm and wireless alarm. The wired alarm was considered to be more environmentally friendly in terms of product manufacturing but the wireless alarm has an advantage in terms of design and energy efficiency. By combining LCA and DFA design evaluation, a more comprehensive perspective of the product life cycle can be achieved.
19
Goldobina, Anastasiya S., Julia A. Isaeva, and Dmitry M. Nikulin. "EVALUATION OF THE EFFICIENCY OF INTRUSION DETECTION SYSTEMS IN PRODUCTION MANAGEMENT INFORMATION SYSTEM OF A MILITARY-INDUSTRIAL COMPLEX." Interexpo GEO-Siberia 6, no. 1 (July 8, 2020): 99–103. http://dx.doi.org/10.33764/2618-981x-2020-6-1-99-103.
Full textAbstract:
Security components of the production management information system of the military-industrial complex are a single mechanism that can protect restricted access information from possible violators. If one of the elements of information security does not work efficiency, it will become a problem for the entire defense system of the military-industrial complex. Production management information systems need to take into account all available ways to prevent information leakage to do this, the owners of military-industrial complexes must conduct an efficiency assessment. The article suggests a possible way to solve the problem when considering one of the most important subsystems: intrusion detection system. Currently, there is no methodology for evaluating the efficiency of intrusion detection systems for production management information systems. This system is located on a real object located in the Irkutsk Region and belongs to the military-industrial complex.
20
Gradeci, Klodian, and Umberto Berardi. "Application of probabilistic approaches to the performance evaluation of building envelopes to withstand mould growth." Journal of Building Physics 43, no. 3 (July 10, 2019): 187–207. http://dx.doi.org/10.1177/1744259119861784.
Full textAbstract:
Probabilistic-based approaches for the performance evaluation of building envelopes to withstand mould growth have gained significant attention in recent years. In this article, a scoping review is performed to identify some current challenges and opportunities in probabilistic-based approaches. Therefore, the performance of a highly insulated wall is evaluated by applying a probabilistic-based methodology that accounts for several uncertainties and investigates their significance. A sensitivity analysis is performed according to the Morris method to understand the influence of each parameter and simplify the system representation of this case study. Deficiencies in terms of rain penetration and air leakage are accounted for. The mould growth risk is evaluated by integrating different mould models and assessment criteria. Overall, the performance of the investigated wall is found satisfactory in most of the cases, except when wind-driven rain penetration occurs. The study demonstrates that a probabilistic-based methodology enables a systematic approach to evaluate the performance of building constructions as it accounts for the involved uncertainties, provides a clear association of the microbial growth to its probability of occurrence and enables the identification of the dominant parameters, delivering more comprehensive conclusions.
21
Von Drygalski, Annette, Christian Furlan-Freguia, Laurent O. Mosnier, Wolfram Ruf, and John H. Griffin. "Novel Infrared Fluorescence Methodology Defines An Essential Role for Endothelial Protein C Receptor (EPCR) for Protection Against Vascular Leakage In Inflammation." Blood 116, no. 21 (November 19, 2010): 653. http://dx.doi.org/10.1182/blood.v116.21.653.653.
Full textAbstract:
Abstract Abstract 653 Activated protein C (APC) reduces mortality in adult sepsis and murine sepsis models. In mice, this mortality reduction requires EPCR. Mice with low levels of EPCR (“EPCR low”) are more susceptible to death from lipopolysaccharide (LPS) than wild-type (wt) mice. Mice over-expressing EPCR are resistant to LPS. EPCR binds protein C (PC) and APC and this promotes both PC activation and APC's cytoprotective signaling. In vitro data show that EPCR is important for endothelial barrier integrity but in vivo data for this concept are lacking. To probe EPCR's role in vascular barrier stability in vivo, we challenged EPCR low and wt mice with LPS and assessed vascular permeability based on: 1) plasma extravasation of albumin-bound Evans Blue (EB) dye into organs quantified by Infrared Fluorescence (IRF); 2) intravascular volume contraction in relation to weight loss; and 3) organ pathology. First, we developed a highly novel method for vascular barrier leak in vivo in which albumin-bound EB in organs was quantified by IRF; this method was highly sensitive and allowed EB quantification in organs (lung, kidney, spleen, liver, heart) after i.v. injection of a wide range of EB doses (5 - 50 mg/kg EB). Even 5 mg/kg EB i.v. gave good IRF data showing detectable organ accumulation of EB in wt mice. This low dose of i.v. EB is one-tenth of the EB dose typically used for EB quantification by formamide extraction for 3 days with EB levels determined by absorbance spectrophotometry (“traditional method”). When EB plasma concentrations were determined by the traditional method and by our IRF method in 96 mice, EB values from the two methods correlated significantly (r2=0.9; n=192 plasma samples from 96 mice receiving LPS i.p. (n=48) or saline (n=48)). These comparisons validated our IRF method for vascular leakage. To define sensitivity in organs, the two methods were compared when 25 mg/kg EB i.v. was used in 59 mice receiving LPS (n=39) or saline (n=20). The results showed that EB levels were detected by IRF in all mice for all 7 organ systems studied (= 100%; kidney, lung, peritoneum, heart, spleen, liver, brain). In contrast, the traditional method detected useful EB levels in only 55% of instances and the detection was poorest in spleen (43%) and brain (14%). Nonetheless, in the 55% of instances where EB could be detected by the traditional method, correlations with IRF EB quantitation were significant (r2=0.85). Furthermore, our novel IRF method quantified EB in wet organs, thus permitting subsequent histology of the same organs. Histology is not possible with the traditional method since it requires drying of organs. Second, after we had developed IRF for reliable EB quantitation, we then used IRF to assess EB vascular leak in EPCR low compared to wt mice. Mice received LPS in doses leading to wt 7-day mortality rates of 25% (n=8), 40% (n=14) or 50% (n=8). At 18 hr after LPS or saline, EB was given and 30 min later, mice were sacrificed and EB was determined by IRF. In saline controls, EB levels in organs of EPCR low and wt mice were similar (p=0.3). However, EB levels in organs of EPCR low mice were higher than in wt mice for each LPS dose; e.g., at LD40 and LD50, EB in organs of EPCR low mice was double the EB levels seen for wt mice (p<0.0001) and was significantly increased over baseline (p=0.0006). Mean intravascular plasma volume of EPCR low mice but not of wt mice decreased significantly after LPS (p=0.0004). Since weight loss was identical (6.5%), the plasma volume loss in the EPCR low mice was caused by plasma extravasation. Histology analyses of wet organs previously used for IRF data showed that EPCR low mice had developed pronounced renal hemorrhage, extensive lung injury (H/E stains), and proteinuria (EB in urine). These histological findings were absent or significantly milder in wt mice. In summary, we have developed and applied a novel IRF method to quantify EB in murine organs for assessment of vascular permeability in organs of EPCR low mice and wt mice. EPCR low mice receiving LPS had greater vascular leakage, loss of intravascular plasma, renal hemorrhage, lung injury and proteinuria than wt mice, indicating severe vascular injury. These findings show that EPCR is required to maintain normal vascular integrity in vivo during LPS-induced inflammation, thus further demonstrating the importance of this key receptor that is central to the endogenous protein C pathway. Disclosures: No relevant conflicts of interest to declare.
22
Francisconi-dos-Rios, Luciana Fávaro, Marcela Pagani Calabria, José Carlos Pereira, Jonathan Hatton, Heitor Marques Honório, Linda Wang, and David Geoffrey Gillam. "Knowledge of Brazilian dentists and students in treating dentine hypersensitivity." Research, Society and Development 10, no. 9 (July 25, 2021): e28010917194. http://dx.doi.org/10.33448/rsd-v10i9.17194.
Full textAbstract:
Objective: To evaluate knowledge of undergraduates and qualified dentists from a Brazilian Dental School in treating Dentine Hypersensitivity (DH). Methodology: Data obtained from a 22-item questionnaire were analysed and arranged in distribution figures. Results: Of 100 respondents, 66.3% indicated that up to 25% of their patients had DH; 41.7%, that the duration of discomfort was up to eight weeks; 78.4%, that they examined a patient with DH within the last two-four weeks; and 70.4%, that this was done after the patient initiated the conversation on DH. Most of participants responded DH affects patients’ quality of life, and its aetiology was attrition, exposed dentine, occlusal interference, gingival recession or abrasion. The most common ways to diagnose DH were sensitivity history analysis, clinical examination, clinical testing and probing; and conflicting conditions were fractured restoration, bleaching sensitivity, marginal leakage, chipped tooth and periodontal disease. Furthermore, 82.5% and 78.7% of respondents indicated they were confident in diagnosing DH and providing advice to patients, but only 38.8% identified hydrodynamic theory as its underlying mechanism. To evaluate pain from DH they considered self-assessment, dental examination, dietary analysis and thermal assessment; and as recommendations, the use of desensitizing dentifrices, education on toothbrushing, in-office application of desensitizing products, and restorations. Conclusion: There is still confusion concerning the aetiology, the diagnosis and the subsequent management of DH, and both students and qualified dentists need better education.
23
Akın Tartuk, Gizem, Sadullah Kaya, and Özkan Adıgüzel. "The effect of different final irrigation solutions on apical impermeability." International Dental Research 11, Suppl. 1 (September 30, 2021): 201–5. http://dx.doi.org/10.5577/intdentres.2021.vol11.suppl1.28.
Full textAbstract:
Aim: This study aimed to compare ethylenediaminetetraacetic acid (EDTA), phytic acid, and citric acid as chelation agents in final irrigation procedures on teeth with apical impermeability.
Methodology: We used 66 mandibular premolar teeth with a single root and single canal extracted for periodontal or orthodontic reasons. All teeth crowns were removed to achieve a 14-mm root length. Mechanical preparation of the root canal was completed with a Reciproc R25 (VDW, Munich, Germany) file system. Teeth were randomly separated into three groups: Group 1: 5 ml 17% EDTA, Group 2: 5 ml 1% phytic acid, and Group 3: 5 ml 20% citric acid. We used 6 ml 5.25% sodium hypochlorite (NaOCl) in the mechanical preparation of all groups. Three teeth were selected for both the positive and negative control groups. All teeth in the experimental groups were filled by the lateral condensation method using AH Plus canal sealer and gutta-percha. For hardening of the canal sealer, samples were kept at 37 oC and at 100% humidity in a drying oven for 7 days. Later, following removal from the drying oven, two layers of nail polish were used to cover all but the apical 2 mm of each tooth. The teeth were then kept in 2% methylene blue solution at 37 oC for 7 days. The root was divided by cutting in the buccolingual direction and gutta-percha was removed. The dye leakage was measured linearly in millimeters (mm) under a stereomicroscope.
Results: As a result of the apical leakage assessment, the lowest apical leakage is observed in the phytic acid group. There was a statistically significant difference between the phytic acid group and citric acid group. There was no statistically significant difference between other groups.
Conclusion: While phytic acid showed similar results with EDTA on apical impermeability, it was more effective than citric acid.
How to cite this article: Akın Tartuk G, Kaya S, Adıgüzel Ö. The effect of different final irrigation solutions on apical impermeability. Int Dent Res 2021;11(Suppl.1):201-5. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.28
Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.
24
PHIRI, A. M., D. I. DE POMERAI, D. J. BUTTLE, and J. M. BEHNKE. "A novel assay for the detection of anthelmintic activity mediated by cuticular damage to nematodes: validation onCaenorhabditis elegansexposed to cysteine proteinases." Parasitology 144, no. 5 (January 30, 2017): 583–93. http://dx.doi.org/10.1017/s0031182016002353.
Full textAbstract:
SUMMARYPlant cysteine proteinases (CPs) fromCarica papayakill parasitic and free-living nematodesin vitroby hydrolysis of the worm cuticle, a mechanism that is different to all commercially available synthetic anthelmintics. We have developed a cheap and effective, rapid-throughputCaenorhabditis elegans-based assay for screening plant CP extracts for anthelmintic activity targeting cuticular integrity. The assay exploits colorimetric methodology for assessment of cuticular damage, and is based on the ability of viable cells to incorporate and bind Neutral red dye within lysosomes and to release the dye when damaged. Living worms are pre-stained with the dye, exposed to CPs and then leakage of the dye through the damaged cuticle is quantified by spectrophotometry. In contrast to motility assays and semi-subjective interpretation of microscopical images, this colorimetric assay is independent of observer bias. Our assay was applied to a series ofC. elegans busmutant strains with leaky cuticles and to cystatin knockout mutants. At ambient temperature and over 0.5–24 h, bothbusmutants and the cystatin knockouts were highly susceptible to CPs, whereas wild-type Bristol N2 worms were essentially unstained by Neutral red and unaffected by CPs, providing validation for the utility of this assay.
25
Diehl, William, Abubakr Abdulgadir, Farnoud Farahmand, Jens-Peter Kaps, and Kris Gaj. "Comparison of Cost of Protection against Differential Power Analysis of Selected Authenticated Ciphers." Cryptography 2, no. 3 (September 19, 2018): 26. http://dx.doi.org/10.3390/cryptography2030026.
Full textAbstract:
Authenticated ciphers, which combine the cryptographic services of confidentiality, integrity, and authentication into one algorithmic construct, can potentially provide improved security and efficiencies in the processing of sensitive data. However, they are vulnerable to side-channel attacks such as differential power analysis (DPA). Although the Test Vector Leakage Assessment (TVLA) methodology has been used to confirm improved resistance of block ciphers to DPA after application of countermeasures, extension of TVLA to authenticated ciphers is non-trivial, since authenticated ciphers have expanded input and output requirements, complex interfaces, and long test vectors which include protocol necessary to describe authenticated cipher operations. In this research, we upgrade the FOBOS test architecture with capability to perform TVLA on authenticated ciphers. We show that FPGA implementations of the CAESAR Round 3 candidates ACORN, Ascon, CLOC (with AES and TWINE primitives), SILC (with AES, PRESENT, and LED primitives), JAMBU (with AES and SIMON primitives), and Ketje Jr.; as well as AES-GCM, are vulnerable to 1st order DPA. We then use threshold implementations to protect the above cipher implementations against 1st order DPA, and verify the effectiveness of countermeasures using the TVLA methodology. Finally, we compare the unprotected and protected cipher implementations in terms of area, performance (maximum frequency and throughput), throughput-to-area (TP/A) ratio, power, and energy per bit (E/bit). Our results show that ACORN consumes the lowest number of resources, has the highest TP/A ratio, and is the most energy-efficient of all DPA-resistant implementations. However, Ketje Jr. has the highest throughput.
26
Shanbhag, Vignesh Vishnudas, Thomas Meyer, Leo Caspers, and Rune Schlanbusch. "Acoustic emission based condition monitoring study of piston rod seals by varying speed and pressure parameters." Annual Conference of the PHM Society 12, no. 1 (November 3, 2020): 9. http://dx.doi.org/10.36001/phmconf.2020.v12i1.1133.
Full textAbstract:
Hydraulic cylinders are used in a wide range of applications such as oil drilling equipment, construction vehicles and manufacturing machines. Seal failure is one of the primitive causes of failure in hydraulic cylinders, possibly leading to fluid spill, unscheduled maintenance, reduced availability and thus leading to lower productivity. Regular visual inspection of seals without affecting the productivity is difficult as the seals are placed internally in the hydraulic cylinder requiring disassembly of the piston. Therefore, condition monitoring is required to assess the current health of the seals. There have been successful attempts made in literature for the assessment of seal quality using acoustic emission-based condition monitoring. However, there have been very few studies performed to diagnose the seal failure under varying speed and pressure parameters. Therefore, this study aims at increasing the understanding of seal failure under varying speed and pressure conditions through correlation with the acoustic emission signal. Experiments were performed on a hydraulic test rig using unworn, semi-worn and worn piston rod seals. For each seal wear condition, experiments were performed for five strokes at pressure conditions of 10, 20, 30 and 40 bar and speeds of 50 mm/s and 100 mm/s. Continuous acoustic emission data were acquired during all the tests. The acoustic emission signal of each piston rod stroke was analyzed using different acoustic emission features such as power spectral density, root mean square, peak, mean frequency, median frequency and band power. From the acoustic emission analysis, by using power spectral density, mean frequency and median frequency feature it is possible to identify and segregate unworn seal, leakage due to semi-worn seal and leakage due to worn seal in the test rig. The acoustic emission-based condition monitoring methodology developed in this study lays a strong foundation for further research to develop real-time monitoring of the piston rod seal in hydraulic cylinders that are used in the offshore industry.
27
Famiyeh, Samuel, Ebenezer Adaku, Laud Kissi-Mensah, and Charles Teye Amoatey. "Risk management for a tailings re-mining project in Ghana." International Journal of Managing Projects in Business 8, no. 2 (April 7, 2015): 241–55. http://dx.doi.org/10.1108/ijmpb-04-2014-0033.
Full textAbstract:
Purpose – Proper risk management is a critical requirement for the success of every project. This is, to a large extent, due to the role risk plays in determining project outcomes. The mining sector usually is linked with high environmental, social and economic risks. Hence, the process of systematic risk management applied to a single case study of a tailings re-mining project in Ghana holds the potential for invaluable insights on risk management in the mining sector. The paper aims to discuss these issues. Design/methodology/approach – Mining organization experts were asked to identify project risks, and 50 staff from the organization were invited to make subjective assessments of the probability of occurrence and consequences for each of 15 identified risks. From this assessment, a risk severity matrix was developed. Findings – The findings show that the most severe risks for a tailings re-mining project include spillage caused by leakage from pipes; vandalism by illegal mining operators; late deliveries of mining materials; the effect of rainfall; and failure to gain project approval from the Environmental Protection Agency. Risk treatment options are suggested for these risks. Research limitations/implications – The study is limited to only the risk issues associated with tailings re-mining projects. Practical implications – Practically, this study highlights for mining companies and operators, the critical risks factors that militate against successful tailings re-mining projects. Social implications – This study, essentially, reveals the threat of illegal mining operations to such an important project and hence the need for strong security to avoid such threats. Originality/value – This study contributes to the debate on the risk factors that affect tailings re-mining, especially, from a developing country’s point of view.
28
Boxerman, Jerrold L., Chad C. Quarles, Leland S. Hu, Bradley J. Erickson, Elizabeth R. Gerstner, Marion Smits, Timothy J. Kaufmann, et al. "Consensus recommendations for a dynamic susceptibility contrast MRI protocol for use in high-grade gliomas." Neuro-Oncology 22, no. 9 (June 9, 2020): 1262–75. http://dx.doi.org/10.1093/neuonc/noaa141.
Full textAbstract:
Abstract Despite the widespread clinical use of dynamic susceptibility contrast (DSC) MRI, DSC-MRI methodology has not been standardized, hindering its utilization for response assessment in multicenter trials. Recently, the DSC-MRI Standardization Subcommittee of the Jumpstarting Brain Tumor Drug Development Coalition issued an updated consensus DSC-MRI protocol compatible with the standardized brain tumor imaging protocol (BTIP) for high-grade gliomas that is increasingly used in the clinical setting and is the default MRI protocol for the National Clinical Trials Network. After reviewing the basis for controversy over DSC-MRI protocols, this paper provides evidence-based best practices for clinical DSC-MRI as determined by the Committee, including pulse sequence (gradient echo vs spin echo), BTIP-compliant contrast agent dosing (preload and bolus), flip angle (FA), echo time (TE), and post-processing leakage correction. In summary, full-dose preload, full-dose bolus dosing using intermediate (60°) FA and field strength-dependent TE (40–50 ms at 1.5 T, 20–35 ms at 3 T) provides overall best accuracy and precision for cerebral blood volume estimates. When single-dose contrast agent usage is desired, no-preload, full-dose bolus dosing using low FA (30°) and field strength-dependent TE provides excellent performance, with reduced contrast agent usage and elimination of potential systematic errors introduced by variations in preload dose and incubation time.
29
Ross, Lester, and Kenneth Zhou. "China issues new cybersecurity review measures." Journal of Investment Compliance 22, no. 1 (April 1, 2021): 47–52. http://dx.doi.org/10.1108/joic-10-2020-0039.
Full textAbstract:
Purpose To describe and analyze the implications of the new Measures (the “Measures”) for Cybersecurity Review jointly promulgated on April 27, 2020 by twelve Chinese government departments led by the Cyberspace Administration of China (CAC). Design/methodology/approach Defines the scope of the Measures, explains the functions and obligations of critical information infrastructure operators (each, a CIIO), outlines the self-assessment and cybersecurity review process and discusses the implications of the Measures for foreign companies doing business in China. Findings The Measures impose an obligation on CII operators to apply for a cybersecurity review when they intend to procure network products and services that present or may present a national security concern. Such review will focus not only on national security and data leakage concerns, but also on supply-chain security concerns. The cybersecurity review will likely further the decoupling between China and the US. Practical implications While the Measures are not formally intended to discriminate against foreign products and services, the promulgation of the Measures will have a significant impact on foreign companies that supply network products or services to CII operators in China. Originality/value Practical guidance from lawyers with extensive experience in advising Chinese, US, European and other companies on laws and regulations related to competition, cross-border investments, joint ventures, strategic alliances and international trade matters.
30
Zhang, Anan, Fan Zhang, Zhi Li, Qian Li, Xuliang Zhang, and Jing Wang. "Synergic calculation method of voltage stability L indicator for multi-area power network." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 36, no. 4 (July 3, 2017): 1134–50. http://dx.doi.org/10.1108/compel-10-2016-0439.
Full textAbstract:
Purpose With the growing scale of power grids, integrated power grids often contain multiple areas. When the control centre of each regional grid conducts an assessment of local voltage stability, the calculation is always based on the local regional power grid model. However, less consideration is given to a detailed model of the entire network, which may lead to a large calculation error. Under the premise of ensuring the data and information security of Supervisory Control and Data Acquisition between different regional power grid operation control centres, the purpose of this paper is to reduce calculation error simply by using the data of a local power network. Design/methodology/approach According to the calculation methodology of “decomposition and coordination” and the power balance equation of an interconnected power grid, an improved radial equivalent independent (REI) equivalent method, which can reflect the dynamic characteristics of interconnected power grids to a certain extent, is proposed in this paper. A mathematical model of multi-area-grid L indicator synergic computing is derived as well. Findings With the calculation of Institute of Electrical and Electronics Engineers (IEEE) standard grids and an actual grid model, it is proven that the method proposed in this paper can significantly improve the accuracy of the regional power grid L indicator calculation and achieve the synergic computing of a multi-area power system L indicator, without an increase in data interaction among the regional power grids. Originality/value The indicator of voltage stability among multi-area was obtained by using the improved REI equivalent method with the change of the load participation factor. Particularly, the coordinated calculation method can be implemented on a local power grid without knowledge of all the parameters of its interconnection, which can avoid possible leakage of confidential data and information of the system owners.
31
Bowden, A. R., and A. Rigg. "ASSESSING RISK IN CO2 STORAGE PROJECTS." APPEA Journal 44, no. 1 (2004): 677. http://dx.doi.org/10.1071/aj03034.
Full textAbstract:
A key challenge to researchers involved with geological storage of CO2 has been to develop an appropriate methodology to assess and compare alternative CO2 injection projects on the basis of risk. Technical aspects, such as the risk of leakage and the effectiveness of the intended reservoir, clearly need to be considered, but so do less tangible aspects such as the value and safety of geological storage of CO2, and potential impacts on the community and environment.The RISQUE method has been applied and found to be an appropriate approach to deliver a transparent risk assessment process that can interface with the wider community and allow stakeholders to assess whether the CO2 injection process is safe, measurable and verifiable and whether a selected alternative delivers cost-effective greenhouse benefits.In Australia, under the GEODISC program, the approach was applied to assess the risk posed by conceptual CO2 injection projects in four selected areas: Dongara, Petrel, Gippsland and Carnarvon. The assessment derived outputs that address key project performance indicators that:are useful to compare projects;include technical, economic and community risk events;assist communication of risk to stakeholders;can be incorporated into risk management design of injection projects; andhelp identify specific areas for future research.The approach is to use quantitative techniques to characterise risk in terms of both the likelihood of identified risk events occurring (such as CO2 escape and inadequate injectivity into the storage site) and of their consequences (such as environmental damage and loss of life). The approach integrates current best practice risk assessment methods with best available information provided by an expert panel.The results clearly showed the relationships between containment and effectiveness for all of the four conceptual CO2 injection projects and indicated their acceptability with respect to two KPIs. Benefit-cost analysis showed which projects would probably be viable considering base-case economics, greenhouse benefits, and also the case after risk is taken into account. A societal risk profile was derived to compare the public safety risk posed by the injection projects with commonly accepted engineering target guidelines used for dams. The levels of amenity risk posed to the community by the projects were assessed, and their acceptability with respect to the specific KPI was evaluated.The risk assessment method and structure that was used should be applied to other potential CO2 injection sites to compare and rank their suitability, and to assist selection of the most appropriate site for any injection project. These sites can be reassessed at any time, as further information becomes available.
32
Johnson, Caroline, Morteza Haghighat Sefat, Ahmed H. Elsheikh, and David Davies. "Development of a Probabilistic Framework for Risk-Based Well Decommissioning Design." SPE Journal 26, no. 04 (May 6, 2021): 1946–63. http://dx.doi.org/10.2118/200608-pa.
Full textAbstract:
Summary In the next decades, tens of thousands of well plugging and abandonment (P&A) operations are expected to be executed worldwide. Decommissioning activities in the North Sea alone are forecasted to require 2,624 wells to be plugged and abandoned during the 10-year period starting from 2019 (Oil&Gas_UK 2019). This increase in decommissioning activity level and the associated high costs of permanent P&A operations require new, fit-for-purpose, P&A design tools and operational technologies to ensure safe and cost-effective decommissioning of hydrocarbon production wells. This paper introduces a novel modeling framework to support risk-based evaluation of well P&A designs using a fluid-flow simulation methodology combined with probabilistic estimation techniques. The developed well-centric modeling framework covers the full range of North Sea P&A well designs and allows for quantification of the long-term (thousands of years) evolution of hydrocarbon movement in the plugged and abandoned well. The framework is complemented by an in-house visualization tool for identification of the dominant hydrocarbon flow-paths. Monte Carlo methods are used to account for uncertainties in the modeling inputs, allowing for robust comparison of various P&A design options, which can be ranked on the basis of hydrocarbon leakage risks. The proposed framework is able to model transient conditions within the well P&A system, allowing for the development of new key performance indicators (e.g., time until hydrocarbons reach surface and changes in hydrocarbon saturation within the P&A well). Such key performance indicators are not commonly used, because most published work in this area relies on steady-state P&A models. The developed framework was used in the assessment of several P&A design cases. The results obtained, which are presented in this paper, demonstrate its value for supporting risk-based decision-making by allowing for quantitative comparison of the expected performance of multiple P&A design options for given well/reservoir conditions. The framework can be used for identifying cost-effective, fit-for-purpose P&A designs, for example by optimizing the number, location, and length of wellbore barriers and evaluating the effectiveness of annular cement sheath remedial operations. Additionally, this framework can be used as a sensitivity analysis tool to identify the critical parameters that have the greatest impact on the modeled leakage risks, to guide data acquisition plans and model refinement steps aimed at reducing the uncertainties in key model parameters.
33
Kofinas, Dimitris, Rafal Ulanczyk, and Chrysi S. Laspidou. "Simulation of a Water Distribution Network with Key Performance Indicators for Spatio-Temporal Analysis and Operation of Highly Stressed Water Infrastructure." Water 12, no. 4 (April 17, 2020): 1149. http://dx.doi.org/10.3390/w12041149.
Full textAbstract:
An annual and lumped water balance assessment of a water distribution network is recommended by the International Water Association as a first step and prerequisite for improving the performance of the network by minimizing real/physical water losses, burst incidents, water theft, nonrevenue water, and energy consumption, among others. The current work suggests a modeling approach for developing the water balance of a network spatio-temporarily, in hour time-scale and neighborhood granularity. It exploits already established key performance indicators and introduces some new ones to highlight the potential in improving the management of a water distribution network when having a detailed spatio-temporal supervision, especially when the spatial and temporal conditions are variable. The methodology is applied in a seasonally touristic and hilly case study. Additionally, a pressure management scheme is applied to further exploit the potential of such a toolkit. For the investigated case study, the town of Skiathos, the annual real losses are estimated equal to 50.9–52.2% of the system input volume, while apparent losses are estimated to be about 5.6–6.6%. Losses depict intense seasonal variability. Real losses range from 38.8–39.6% in summer months to 63.3–64.7% in winter months, while apparent losses range from 8.4–9.3% in summer to 1.3–2.5% in winter. Annual water theft is estimated to be at least 3.6% of system input volume. Spatial variability, which is linked to the elevation and the different urban land uses is proven to play a significant role in the neighborhoods’ water balances and various key performance indicators are suggested and applied for the pressure control scheme. The annual potential savings due to the applied scheme rise up to 51,300 m3 for leakage and 53,730 m3 for pressure-driven demand.
34
Brohi, Saifullah, Muhammad Laiq-uz Zaman Khan, Ubedullah Shaikh, and Shazia Ubed Shaikh. "LAPAROSCOPIC CHOLECYSTECTOMY." Professional Medical Journal 21, no. 04 (December 7, 2018): 601–5. http://dx.doi.org/10.29309/tpmj/2014.21.04.2415.
Full textAbstract:
Objective: To assess various intra operative predictive factors which arereponsible for difficulty in performing laparoscopic cholecystectomy. Study Design: Prospectiveobservational study. Place and Duration of Study: This study was out in Surgical department,Liaquat University Hospital Jamshoro, Dow International Hospital Karachi and JinnahPostgraduate Medical Center Karachi, from October 2012 to October 2013. Methodology: Thisstudy consisted of hundred patients. Detailed History was taken from all the patients with specialregard to the abdominal pain or pain in right hypochondrium, lump in right hypochondrium ,vomiting , dyspepsia and fever. Detailed Clinical examination of the patient was done . Site of righthypochondrium was especially examined for assessment of murphy’s sign , palpable mass ,visceromegaly and recorded in proforma. Systemic review was also done to see any comorbidity.Ultrasound of abdomen as diagnostic modality and for assessment of gallstonedisease. Inclusion criteria were all diagnosed patients of complicated and uncomplicated gallstone disease of any age and either any sex admitted on the basis of history , clinical examinationand investigations specially ultrasound of abdomen. Exclusion criteria included unfit patients forgeneral anesthesia , Pregnant ladies due to risk of foetal loss, patient with carcinoma of gallbladder , patient with acute pancreatitis and Patient with obstructive jaundice. Follow up of allthese patients was done. Results were prepared with help of tables and graphs. Data wasanalyzed through SPSS software. Results: Out of 100 patients included in this study 79 werefemale (79%) and 21 male (21%); with female to male ratio of 3.76:1. There was wide variation ofage ranging from a minimum of 20 years to 65 years . The mean age was 46.28+7.20 years.Symptoms of patients presented with pain in RHC 87% , pain in RHC along with pain inepigastrium 78%, Nausea & Vomiting 15%, dyspepsia 50% and fever in 10% of cases.Ultrasound examination revealed single stone in 20(20%) patients where as multiple stones in80(80%) patients. Operative findings revealed severe adhesions in calot’s triangle in 15(15%)patients where as Severe & tight adhesions around gallbladder in 16(16%) patients, Obscuredanatomy in calot’s triangle in 11(11%) patients and Intrahepatic gallbladder in 9(9%) patients.Complications were Pain in 33(33%) patients, Bleeding in 1(1%) patients, Intraperitonealcollection in 2(2%) patients, Wound Sepsis in 5(5%) patients and Biliary leakage in one case.Conclusions: In conclusion our study revealed that are numerous conditions which make thedifficult laparoscopic cholecystectomy like severe adhesions in calot’s triangle 15%, Severe &tight adhesions around gallbladder 16%, Obscured anatomy in calot’s triangle 11%, Intrahepaticgallbladder 9% and adhesions around gallbladder 26%.
35
Haziel Mbasiti, Taiya, Jugu Yohanna Gyang, and Ojaide Fransis. "AN ASSESSMENT OF FORENSIC ACCOUNTING TECHNIQUES IN THE PREVENTION OF REVENUE LEAKAGES IN NIGERIAN FEDERAL UNIVERSITIES." Journal of Accounting 4, no. 1 (July 2, 2021): 1–21. http://dx.doi.org/10.47941/jacc.601.
Full textAbstract:
Purpose: Forensic accounting reflects the application of investigative and analytical techniques for the purpose of resolving fraudulent practices. The purpose of the research was to examine the extent at which Forensic Accounting Techniques serves as a panacea for preventing Revenue Leakages in Federal Universities in Nigeria.
Methodology: Primary data were collected with the aid of research questionnaire and used in this study. The sample size of 238 respondents was determined from a census of targeted EFCC, internal audit staff of selected Nigerian Federal Universities. This study applied a statistical tool, which described and evaluated the relationships between Forensic accounting techniques and revenue leakages.
Findings: The methodology shows that Forensic accounting data analysis techniques have positive effects on revenue leakages in Nigerian Federal Universities. This implies that a forensic data analysis technique can help in uncovering leakages of revenue in Nigerian Federal Universities. The implication is that when these technologies are applied, there would be drastic reduction in revenue leakages. From the findings, it was concluded that the application of forensic accounting techniques will help in preventing revenue leakages in Nigerian Federal Universities.
Unique Contribution to Theory, Practice and Policy: On the basis of these findings and conclusion, it was recommended that forensic accounting data analysis and technology techniques should be employed in Nigerian Federal Universities to help them curb revenue leakages in the system. That will help to discover and analyse patterns of fraudulent activities and develop sorts of digital tools that would be found helpful in fighting economic and financial crimes within the system.
Keywords: Forensic Accounting, Revenue Leakages, Frauds, Forensic Accounting Technologies
36
Cunha Marques, R., and A. J. Monteiro. "Application of performance indicators to control losses - results from the Portuguese water sector." Water Supply 3, no. 1-2 (March 1, 2003): 127–33. http://dx.doi.org/10.2166/ws.2003.0095.
Full textAbstract:
More and more the problem of water losses and leakages in water supply systems is becoming important in the management of water utilities. No matter how developed a country is, there is a growing and general awareness of this subject. Among the several motivations that contribute to this growing concern are, without doubt, the shortage of resources availability in several water supply systems on the one hand and, on the other hand, the economic value of the volume of water lost. Portugal is no exception. In recent years, there has been some dynamism in the sector in the accounting, control, leakages and loss detection, mainly in the biggest systems. This paper presents an approach to the control of water leakages and losses through the setting of performance indicators that allow the evaluation and characterization of the management entity for this aspect. Some results of those indicators will also be described here, as well as their application to several Portuguese water utilities and the assessment methodology of the results obtained. This paper also puts into evidence expressions and correlation curves between the different indicators and factors that directly or indirectly interfere in the result of the water utilities’ performance with relation to the water losses and leakages presented.
37
Lyng, Kari-Anne, and Andreas Brekke. "Environmental Life Cycle Assessment of Biogas as a Fuel for Transport Compared with Alternative Fuels." Energies 12, no. 3 (February 7, 2019): 532. http://dx.doi.org/10.3390/en12030532.
Full textAbstract:
Upgraded biogas, also known as biomethane, is increasingly being used as a fuel for transport in several countries and is regarded as an environmentally beneficial option. There are, nevertheless, few studies documenting the environmental impacts of biogas as a transport fuel compared with the alternatives on the market. In this study, life cycle assessment (LCA) methodology was applied to compare the environmental performance of biogas used as a fuel for bus transport with natural gas, electricity fueled buses, biodiesel, and fossil diesel. A sensitivity analysis was performed for the biogas alternative to assess the importance of the underlying assumptions. The results show that biogas has a relatively low contribution to the environmental impact categories assessed. Emissions of greenhouse gases are dependent on assumptions such as system boundaries, transport distances and methane leakages.
38
Sharma, Satyendra, and Srikanta Routroy. "Modeling information risk in supply chain using Bayesian networks." Journal of Enterprise Information Management 29, no. 2 (March 7, 2016): 238–54. http://dx.doi.org/10.1108/jeim-03-2014-0031.
Full textAbstract:
Purpose – Information sharing enhances the supply chain profitability significantly, but it may result in adverse impacts also (e.g. leakages of secret information to competitors, sharing of wrong information that result into losses). So, it is important to understand the various risk factors that lead to distortion in information sharing and results in negative consequences. Information risk identification and assessment in supply chain would help in choosing right mitigation strategies. The purpose of this paper is to identify various information risks that could impact a supply chain, and develop a conceptual framework to quantify them. Design/methodology/approach – Bayesian belief network (BBN) modeling will be used to provide a framework for information risk analysis in a supply chain. Bayesian methodology provides the reasoning in causal relationship among various risk factors and incorporates both objective and subjective data. Findings – This paper presents a causal relationship among various information risks in a supply chain. Three important risk factors, namely, information security, information leakages and reluctance toward information sharing showed influence on a company’s revenue. Practical implications – Capability of Bayesian networks while modeling in uncertain conditions, provides a prefect platform for analyzing the risk factors. BBN provides a more robust method for studying the impact or predicting various risk factors. Originality/value – The major contribution of this paper is to develop a quantitative model for information risks in supply chain. This model can be updated when a new data arrives.
39
Ramaraj, Prashanth, Jonathan Super, Ruben Doyle, Christopher Aylwin, and Shehan Hettiaratchy. "Triaging of respiratory protective equipment on the assumed risk of SARS-CoV-2 aerosol exposure in patient-facing healthcare workers delivering secondary care: a rapid review." BMJ Open 10, no. 10 (October 2020): e040321. http://dx.doi.org/10.1136/bmjopen-2020-040321.
Full textAbstract:
ObjectivesIn patient-facing healthcare workers delivering secondary care, what is the evidence behind UK Government personal protective equipment (PPE) guidance on surgical masks versus respirators for SARS-CoV-2 protection?DesignTwo independent reviewers performed a rapid review. Appraisal was performed using Critical Appraisal Skills Programme checklists and Grading of Recommendations, Assessment, Development and Evaluations methodology. Results were synthesised by comparison of findings and appraisals.Data sourcesMEDLINE, Google Scholar, UK Government COVID-19 website and grey literature.Eligibility criteriaStudies published on any date containing primary data comparing surgical facemasks and respirators specific to SARS-CoV-2, and studies underpinning UK Government PPE guidance, were included.ResultsOf 30 identified, only 3 laboratory studies of 14 different respirators and 12 surgical facemasks were found. In all three, respirators were significantly more effective than facemasks when comparing protection factors, reduction factors, filter penetrations, total inspiratory leakages at differing particle sizes, mean inspiratory flows and breathing rates. Tests included live viruses and inert particles on dummies and humans. In the six clinical studies (6502 participants) included the only statistically significant result found continuous use of respirators more effective in clinical respiratory illness compared with targeted use or surgical facemasks. There was no consistent definition of ‘exposure’ to determine the efficacy of respiratory protective equipment (RPE). It is difficult to define ‘safe’.ConclusionsThere is a paucity of evidence on the comparison of facemasks and respirators specific to SARS-CoV-2, and poor-quality evidence in other contexts. The use of surrogates results in extrapolation of non-SARS-CoV-2 specific data to guide UK Government PPE guidance. The appropriateness of this is unknown given the uncertainty over the transmission of SARS-CoV-2.This means that the evidence base for UK Government PPE guidelines is not based on SARS-CoV-2 and requires generalisation from low-quality evidence of other pathogens/particles. There is a paucity of high-quality evidence regarding the efficacy of RPE specific to SARS-CoV-2. UK Government PPE guidelines are underpinned by the assumption of droplet transmission of SARS-CoV-2.These factors suggest that the triaging of filtering face piece class 3 respirators might increase the risk of COVID-19 faced by some.
40
Moos, Thorben, Felix Wegener, and Amir Moradi. "DL-LA: Deep Learning Leakage Assessment." IACR Transactions on Cryptographic Hardware and Embedded Systems, July 9, 2021, 552–98. http://dx.doi.org/10.46586/tches.v2021.i3.552-598.
Full textAbstract:
In recent years, deep learning has become an attractive ingredient to side-channel analysis (SCA) due to its potential to improve the success probability or enhance the performance of certain frequently executed tasks. One task that is commonly assisted by machine learning techniques is the profiling of a device’s leakage behavior in order to carry out a template attack. At CHES 2019, deep learning has also been applied to non-profiled scenarios for the first time, extending its reach within SCA beyond template attacks. The proposed method, called DDLA, has some tempting advantages over traditional SCA due to merits inherited from (convolutional) neural networks. Most notably, it greatly reduces the need for pre-processing steps< when the SCA traces are misaligned or when the leakage is of a multivariate nature. However, similar to traditional attack scenarios the success of this approach highly depends on the correct choice of a leakage model and the intermediate value to target. In this work we explore, for the first time in literature, whether deep learning can similarly be used as an instrument to advance another crucial (non-profiled) discipline of SCA which is inherently independent of leakage models and targeted intermediates, namely leakage assessment. In fact, given the simple classification-based nature of common leakage assessment techniques, in particular distinguishing two groups fixed-vs-random or fixed-vs-fixed, it comes as a surprise that machine learning has not been brought into this context, yet. Our contribution is the development of the first full leakage assessment methodology based on deep learning. It gives the evaluator the freedom to not worry about location, alignment and statistical order of the leakages and easily covers multivariate and horizontal patterns as well. We test our approach against a number of case studies based on FPGA, ASIC and μC implementations of the PRESENT block cipher, equipped with state-of-the-art SCA countermeasures. Our results clearly show that the proposed methodology and network structures are robust across all case studies and outperform the classical detection approaches (t-test and X2-test) in all considered scenarios.
41
Dia, Ben Mansour. "Bayesian experimental design for CO2 sequestration with leakage risk assessment." Engineering Computations ahead-of-print, ahead-of-print (December 15, 2020). http://dx.doi.org/10.1108/ec-03-2020-0143.
Full textAbstract:
Purpose This study aims to examine the sequestration of carbon dioxide (CO2) in abandoned geological formations where leakages are permitted up to only a certain threshold to meet the international CO2 emissions standards. Technically, the author addresses a Bayesian experimental design problem to optimally mitigate uncertainties and to perform risk assessment on a CO2 sequestration model, where the parameters to be inferred are random subsurface properties while the quantity of interest is desired to be kept within safety margins. Design/methodology/approach The author starts with a probabilistic formulation of learning the leakage rate and later relaxes it to a Bayesian experimental design of learning the formations geophysical properties. The injection rate is the design parameter and the learned properties are used to estimate the leakage rate by means of a nonlinear operator. The forward model governs a two-phase two-component flow in a porous medium with no solubility of CO2 in water. The Laplace approximation is combined with Monte Carlo sampling to estimate the expectation of the Kullback–Leibler divergence that stands for the objective function. Practical implications The injection duration given by the reservoir capacity is extended while the environment is preserved despite the leakage.
42
Govindan, Rajesh, Zhenggang Nie, Anna Korre, Sevket Durucan, Ji-Quan Shi, Mojgan Hadi Mosleh, Filip Neele, Mark Wilkinson, and Niklas Heinemann. "A Methodology for CO2 Storage Leakage Remediation Techniques Performance Assessment and Portfolio Optimisation." SSRN Electronic Journal, 2019. http://dx.doi.org/10.2139/ssrn.3366046.
Full text
43
Santos, Livio, and Arash Dahi Taleghani. "On Quantitative Assessment of Effective Cement Bonding to Guarantee Wellbore Integrity." Journal of Energy Resources Technology 144, no. 1 (May 7, 2021). http://dx.doi.org/10.1115/1.4050878.
Full textAbstract:
Abstract Methane leakage due to compromised wellbore cement integrity may result in operational complications and environmental contaminations in oil and gas wells. In this work, the problem of fluid-driven fracture propagation at the cement interfaces is revisited by a thorough and comprehensive consideration of the non-uniform cement bonding to the formation along the wellbore. While previous works were mainly focused on discharge without attention to mechanical failure or mechanical failure without ties to seepage rate; here, we couple these two analyses to provide a practical aspect of this approach. As revealed by cement evaluation logs, the quality of the cement behind the casing varies and may include flaws in the form of channels or pockets of mud residuals. A novel methodology, initiated with laboratory-scale cement bonding properties using the push-out test, is introduced to estimate the cohesive properties of the cement interface, considering mud removal and mud residuals in the rock. Then, the measured cohesive properties are applied to a field-scale numerical model with an embedded cohesive layer between cement and formation to evaluate the susceptibility of the wellbore to develop cement debonding. The excessive fluid pressure at the casing shoe is assumed to be the source for the fracture initiation. The proposed numerical model has been tested against actual sustained casing pressure (SCP) field tests for validation purposes. This model may estimate the geometry of leakage pathways and predict leakage flowrate within acceptable ranges. The effect of several key factors in the development of SCP due to the cement debonding is investigated. The results show that the early stage of SCP buildup is controlled by the cohesive properties of the cement interfaces (i.e., cement properties), but the cohesive properties have minor effects on the stabilized pressure. The method proposed herein presents a method to evaluate the cement bond quantitatively to be further integrated into cement design.
44
Ćipranić, Ivana, Marija Jevrić, Milan Radulović, and Goran Sekulić. "The energy – pressure nexus in the water supply system." Water Supply, October 23, 2020. http://dx.doi.org/10.2166/ws.2020.285.
Full textAbstract:
Abstract Due to the importance of overall sustainable development, efficient energy management should be as significant as water resource management within every water supply system. The pressure reduction, as a measure for loss reduction, not only guarantees less leakage but also minimizes energy consumption. The relationship between energy consumption and pressure in water supply systems has been the subject of many previous studies, mainly based on measurements in real systems. However, a methodology for beforehand assessment of energy savings which occur due to the pressure reduction, has not been proposed yet. The paper proposed a method for the assessment of energy savings in relation to pressure reduction, implemented it on the hypothetical water supply system and verified it on the real system. Results led to the conclusion that the proposed methodology can be considered as a successful tool for better energy and water management. It enables water utility management to estimate energy saving in water supply system in advance, based on the hydraulic model of the system.
45
Lindgren, J. Fredrik, Frida Åberg, and Josephine Rubia Johansson. "Polluting shipwrecks in Swedish waters: investigations, risk assessment methodology and oil removal operations." International Oil Spill Conference Proceedings 2021, no. 1 (May 1, 2021). http://dx.doi.org/10.7901/2169-3358-2021.1.684035.
Full textAbstract:
ABSTRACT Large amounts of oil exists in old shipwrecks worldwide, both as cargo and bunker. This oil will eventually enter the marine environment as the ship hulls deteriorate or as other types of activities affect the wrecks. Oil being a complex mixture of hazardous substances will when released into the marine environment be a source of both lethal and sub-lethal effects to organisms. Costs of an oil spill in the marine environment, including clean-up actions, socioeconomic and environmental costs is often substantial. Sweden has a ten year nationally funded program where oil removal operations on shipwrecks are performed. From a list of 300 potentially polluting shipwrecks, 31 wrecks have initially been selected for oil removal operations. In a first stage extensive gathering of information was performed regarding each wreck, both archive data and in-situ data at the wreck site. Secondly, a risk analysis was carried out. Based on the probability of oil leakage, amount of oil in the wreck and sensitivity of recipients, a prioritization for oil removal operations was made of the 31 wrecks. Based on the prioritization, time of the year and cost of an operation wrecks are finally selected for oil removal operation. So far, since 2017, five operations have been performed. During 2019 and 2020, two successful oil removal operations were carried out. The ship Lindesnäs wrecked 1957 in a snow storm close to the lighthouse Norra Kränkan on the Swedish east coast with a cargo of kerosene and diesel as bunker fuel. The operation from mobilization to demobilization lasted for 22 days, and 299 m3 of oil and a large ghost net was removed from the wreck. Secondly, Finnbirch, which wrecked in 2006 east of the island of Öland and started to leak oil during the end of 2018, was salvaged in a two-part operation. In 2019, 60 m3 of diesel fuel and lubricant oil were salvaged, during a fourteen-day operation. In 2020, 114 m3 of heavy fuel oil (HFO) was salvaged from the wreck during a fifteen-day operation. The costs per ton of removed oil were far less than cost for oil clean-up operations in Swedish waters. In conclusion, using a risk-based approach for prioritization of potentially polluting shipwrecks and the subsequent proactive removal of oil from shipwrecks is a cost-effective approach to alleviate the problem.
46
Bielawski, Piotr Jan. "Identification of the piston machine combustion chamber tightness." Journal of Quality in Maintenance Engineering ahead-of-print, ahead-of-print (December 18, 2020). http://dx.doi.org/10.1108/jqme-10-2019-0096.
Full textAbstract:
PurposeThe lack of integrity of the piston machine combustion chamber manifests itself in leakages of the working fluid between the piston and the cylinder liner, at valves mounted in the cylinder head and between the head and the liner. An untight combustion chamber leads to decreased power output or efficiency of the engine, while leaks of a fluid may cause damage to many components of the chamber. The actual value of working chamber leak is a desired and essential piece of information for planning operations of a given machine.Design/methodology/approachThis research paper describes causes and mechanisms of leakage from the working chamber of internal combustion engines. Besides, the paper outlines presently used methods and means of leak identification and states that their further development and improvements are needed. New methods and their applicability are presented.FindingsThe methods of leak identification have been divided into diagnostic and non-working machine leak identification methods. The need has been justified for the identification of leakage from the combustion chamber of a non-working machine and for using the leakage measure as the value of the cross-sectional area of the equivalent leak, defined as the sum of cross-section areas of all leaking paths. The analysis of possible developments of tightness assessment methods referring to the combustion chamber of a non-working machine consisted in modelling subsequent combustion chamber leaks as gas-filled tank leak, leak from another element of gas-filled tank and as a regulator of gas flow through a nozzle.Originality/valueA measurement system was built allowing the measurement of pressure drop in a tank with the connected engine combustion chamber, which indicated the usefulness of the system for leakage measurement in units as defined in applicable standards. A pneumatic sensor was built for measuring the cross-sectional area of the equivalent leak of the combustion chamber connected to the sensor where the chamber functioned as a regulator of gas flow through the sensor nozzle. It has been shown that the sensor can be calibrated by means of reference leaks implemented as nozzles of specific diameters and lengths. The schematic diagram of a system for measuring the combustion chamber leakage and a diagram of a sensor for measuring the cross-sectional area of the equivalent leak of the combustion chamber leakage are presented. The results are given of tightness tests of a small one-cylinder combustion engine conducted by means of the set up measurement system and a pre-prototype pneumatic sensor. The two solutions proved to be practically useful.
47
Vincent, Brady T., Marwan A. Hassan, and Robert J. Rogers. "A Probabilistic Assessment Technique Applied to a Cracked Heat Exchanger Tube Subjected to Flow-Induced Vibration." Journal of Pressure Vessel Technology 131, no. 3 (April 13, 2009). http://dx.doi.org/10.1115/1.3109989.
Full textAbstract:
Flow-induced vibration is a common phenomenon in shell-and-tube heat exchangers. The resulting vibration can lead to component failure by fretting wear due to tube-to-tube support impact or by fatigue. Due to manufacturing considerations, many parameters such as support clearance, alignment, and friction at the supports are not exactly known and are represented by statistical distributions. This makes the use of deterministic equations inaccurate. This paper presents a methodology that can be used during component operation to monitor known flaws and ensure safe operation. The methodology incorporates Monte Carlo simulations to predict remaining service life of a vibrating heat exchanger tube with a small circumferential through-wall crack next to the tube sheet. Vibration excitation includes turbulence and low-level fluid-elastic forces. Leakage calculations are made on the through-wall crack as it grows to fracture. A Weibull distribution is given for the time-to-fracture and for the time for the leak rate to reach a threshold value. This statistical information can then be used to assess the remaining service life and whether LBB criteria will be met.
48
Bronchain, Olivier, Tobias Schneider, and François-Xavier Standaert. "Multi-Tuple Leakage Detection and the Dependent Signal Issue." IACR Transactions on Cryptographic Hardware and Embedded Systems, February 28, 2019, 318–45. http://dx.doi.org/10.46586/tches.v2019.i2.318-345.
Full textAbstract:
Leakage detection is a common tool to quickly assess the security of a cryptographic implementation against side-channel attacks. The Test Vector Leakage Assessment (TVLA) methodology using Welch’s t-test, proposed by Cryptography Research, is currently the most popular example of such tools, thanks to its simplicity and good detection speed compared to attack-based evaluations. However, as any statistical test, it is based on certain assumptions about the processed samples and its detection performances strongly depend on parameters like the measurement’s Signal-to-Noise Ratio (SNR), their degree of dependency, and their density, i.e., the ratio between the amount of informative and non-informative points in the traces. In this paper, we argue that the correct interpretation of leakage detection results requires knowledge of these parameters which are a priori unknown to the evaluator, and, therefore, poses a non-trivial challenge to evaluators (especially if restricted to only one test). For this purpose, we first explore the concept of multi-tuple detection, which is able to exploit differences between multiple informative points of a trace more effectively than tests relying on the minimum p-value of concurrent univariate tests. To this end, we map the common Hotelling’s T2-test to the leakage detection setting and, further, propose a specialized instantiation of it which trades computational overheads for a dependency assumption. Our experiments show that there is not one test that is the optimal choice for every leakage scenario. Second, we highlight the importance of the assumption that the samples at each point in time are independent, which is frequently considered in leakage detection, e.g., with Welch’s t-test. Using simulated and practical experiments, we show that (i) this assumption is often violated in practice, and (ii) deviations from it can affect the detection performances, making the correct interpretation of the results more difficult. Finally, we consolidate our findings by providing guidelines on how to use a combination of established and newly-proposed leakage detection tools to infer the measurements parameters. This enables a better interpretation of the tests’ results than the current state-of-the-art (yet still relying on heuristics for the most challenging evaluation scenarios).
49
Rahmi, Gabriel, Emmanuel Coron, Guillaume Perrod, Michael Levy, Jacques Moreau, Driffa Moussata, Enrique Perez-Cuadrado-Robles, et al. "Probe-based confocal laser endomicroscopy for in vivo assessment of histological healing in ulcerative colitis: development and validation of the ENHANCE index." Journal of Crohn's and Colitis, December 18, 2020. http://dx.doi.org/10.1093/ecco-jcc/jjaa255.
Full textAbstract:
Abstract Background and aims Histological healing may represent the ultimate therapeutic goal in ulcerative colitis (UC), but it requires biopsies. Our aim was to develop a non-invasive index able to assess histological disease activity in ulcerative colitis using probe based confocal laser endomicroscopy (pCLE). Methods One hundred patients with quiescent UC were prospectively included in 5 French centres. After fluorescein intravenous injection, during colonoscopy, the colorectal mucosa was analysed by white light imaging, pCLE and then biopsied in different locations. Five endoscopists performed central reading of pCLE images blindly to clinical, endoscopic and histological data. One expert pathologist performed a central histological reading (Nancy index: gold standard). An univariate and multivariate analysis were performed to identify the endomicroscopic items associated with the presence of histologically active disease. Results Over 1000 pCLE videos sequences performed in 100 UC patients in endoscopic remission (Mayo 0 and 1) were evaluated. We observed that vessel diameter > 20 µm, dilated crypt lumen, fluorescein leakage and irregular crypt architecture were statistically associated with histologically proven inflammation according to the Nancy index. Hence, we built a pCLE index of mucosal inflammation that overall accuracy was of 79.6% and overall sensitivity and specificity were respectively of 57.8% and 82.8%. Negative predictive value, especially when a pCLE index ≤ 1 is observed was high (93.1%). Conclusion Using a robust methodology, large vessel diameter, dilated crypt lumen, fluorescein leakage and irregular crypt architecture are reliable endomicroscopic items defining the ENHANCE index for real-time assessment of histological disease activity in UC.
50
Nurgalieva, Kuralay, Leila Mardenova, and Anel Usenova. "Development of Measures to Amend the Labour Protection Regulations of the Chemical and Petrochemical Industry of Kazakhstan." Eurasian Journal of Economic and Business Studies 1, no. 63 (March 31, 2022). http://dx.doi.org/10.47703/ejebs.v1i63.78.
Full textAbstract:
The chemicals and petrochemicals industry is currently one of the world's leading international economies. But at the same time it also remains an industry where harmful, difficult and hazardous working conditions for workers are present. All occupational safety and health protection measures must be aimed at achieving the main objective of reducing the level of occupational diseases on the basis of, first and foremost, preventive work on risk factors. Professional activity at chemical and petrochemical enterprises reveals the necessity to develop a clear algorithm of occupational risk analysis, which has a common basis with assessment of other technical risks. The chemical and petrochemical industry is an industry with a large number of risks: risk of fire, risk of explosion, risk of leakage of harmful chemicals, risk of evaporation of harmful chemicals. All these risks entail risks of getting sick: respiratory tract cancer, etc. and the resulting disability or disablement.
This article examines some methods of occupational risk assessment in the chemical and petrochemical industry. Analysis of methodologies such as the ranking of occupational hazards, the Kwij Al-Dalemi occupational risk assessment, as well as the French experience of the Laboratory Laboratory Network-Prevention Network-National Surveillance for Occupational Diseases (Research National de Vigilance et de Prevention des Pathologies Professionneles, RNV3P) and the US experience of LHAT-Laboratory for Hazardous Substances Assessment in Iowa State in the USA. The article details the methodology for ranking occupational hazards in chemical plants and shows the ranking of occupational hazards by priority and their short- and long-term exposure.