1,690 research outputs found
Development of an ontology supporting failure analysis of surface safety valves used in Oil & Gas applications
Treball desenvolupat dins el marc del programa 'European Project Semester'.The project describes how to apply Root Cause Analysis (RCA) in the form of a Failure Mode Effect and Criticality Analysis (FMECA) on hydraulically actuated Surface Safety Valves (SSVs) of Xmas trees in oil and gas applications, in order to be able to predict the occurrence of failures and implement preventive measures such as Condition and Performance Monitoring (CPM) to improve the life-span of a valve and decrease maintenance downtime. In the oil and gas industry, valves account for 52% of failures in the system. If these failures happen unexpectedly it can cause a lot of problems. Downtime of the oil well quickly becomes an expensive problem, unscheduled maintenance takes a lot of extra time and the lead-time for replacement parts can be up to 6 months. This is why being able to predict these failures beforehand is something that can bring a lot of benefits to a company. To determine the best course of action to take in order to be able to predict failures, a FMECA report is created. This is an analysis where all possible failures of all components are catalogued and given a Risk Priority Number (RPN), which has three variables: severity, detectability and occurrence. Each of these is given a rating between 0 and 10 and then the variables are multiplied with each other, resulting in the RPN. The components with an RPN above an acceptable risk level are then further investigated to see how to be able to detect them beforehand and how to mitigate the risk that they pose. Applying FMECA to the SSV mean breaking the system down into its components and determining the function, dependency and possible failures. To this end, the SSV is broken up into three sub-systems: the valve, the actuator and the hydraulic system. The hydraulic system is the sub-system of the SSV responsible for containing, transporting and pressurizing of the hydraulic fluid and in turn, the actuator. It also contains all the safety features, such as pressure pilots, and a trip system in case a problem is detected in the oil line.
The actuator is, as the name implies, the sub-system which opens and closes the valve. It is made up of a number of parts such as a cylinder, a piston and a spring. These parts are interconnected in a number of ways to allow the actuator to successfully perform its function.
The valve is the actual part of the system which interacts with the oil line by opening and closing. Like the actuator, this sub-system is broken down into a number of parts which work together to perform its function.
After breaking down and defining each subsystem on a functional level, a model was created using a functional block diagram. Each component also allows for the defining of dependencies and interactions between the different components and a failure diagram for each component. This model integrates the three sub-systems back into one, creating a complete picture of the entire system which can then be used to determine the effects of different failures in components to the rest of the system.
With this model completed we created a comprehensive FMECA report and test the different possible CPM solutions to mitigate the largest risks
Systems at Play: The Construction of International Systems in Social Impact Games
This thesis explores how game makers conceive of and navigate the intersection between digital systems and real world systems by asking, how can social impact game designers shape procedural rhetoric to effectively address complex real world systems with digital systems? By examining three game case studies, I reach four significant findings regarding player agency, subversive play, design approaches to scale, and game difficulty in regards to systems fluency
Calidad de las instituciones y su relación
El presente artículo analiza los principales elementos y variables relacionadoscon la calidad de las instituciones que pueden influir en eldesempeño económico de la región Caribe colombiana. El objetivocentral es aportar nueva evidencia al debate existente en torno a cuálesson los factores asociados al desempeño institucional, específicamentede las organizaciones públicas departamentales de la región Caribecolombiana. La importancia de este tipo de análisis radica en queviene a promover e identificar mediciones relacionadas con la calidadinstitucional, pues si se logra establecer las causas del mal ejerciciode las organizaciones, principalmente las públicas, comienza el me-joramiento del desempeño económico de cualquier país o nación. This paper analyzes the main elements and variables related tothe quality of public institutions that can influence the economicperformance of the Colombian Caribbean region. The main objectiveis to contribute with new evidence to the existing debate regardingfactors that are associated to the institutional performance, specificallyof the quality of public institutions of the Colombian Caribbean region.The importance of this type of analysis is that it serves as a point ofdeparture to underline and to identify measurements related to theinstitutional quality, because the first step to improve the economicperformance of any country or region is the establishment of thecauses for the bad performance, mainly of the public institutions.instituciones, calidad institucional, crecimiento económico / Institutions, Institutional Quality, Economic Growth
A Novel Artificial Organic Controller with Hermite Optical Flow Feedback for Mobile Robot Navigation
This chapter describes a novel nature-inspired and intelligent control system for mobile robot navigation using a fuzzy-molecular inference (FMI) system as the control strategy and a single vision-based sensor device, that is, image acquisition system, as feedback. In particular, FMI system is proposed as a hybrid fuzzy inference system with an artificial hydrocarbon network structure as defuzzifier that deals with uncertainty in motion feedback, improving robot navigation in dynamic environments. Additionally, the robotics system uses processed information from an image acquisition device using a real-time Hermite optical flow approach. This organic and nature-inspired control strategy was compared with a conventional controller and validated in an educational robot platform, providing excellent results when navigating in dynamic environments with a single-constrained perception device
Coping strategies assumed by students of the Simón Bolívar University in virtual classes due to the covid 19 crisis
Given the crisis and vulnerability that occurred around the pandemic due to the effects of Covid-19, education was one of the main systems that had to be addressed. The objective of this study was to determine the coping strategies in relation to the level of stress due to the new conditions of readaptation to the virtual modality for the continuity of academic processes in eighth-semester students of the Psychology Program of the Simón Bolívar University, Barranquilla, due to the sudden appearance of the Covid-19 virus. Method: it was based on a non-experimental study, with a quantitative design, with the application of a cross-sectional survey applied through "Google Forms". Conclusions: the students induced to find a better balance and alternatives in their system by the new virtual academic modality, also applied, with the development of technologies, appropriation strategies and "gathering additional information about this issue, finding out more about the problem", which allowed them to prepare for the new phenomenon and acquire a new teaching-learning modality that was previously invisible.Ante la crisis y vulnerabilidad que aconteció alrededor de la pandemia por efectos del Covid-19, la educación constituyó uno de los principales sistemas que debió luchar para que no se detuviera. Este estudio tuvo como objetivo determinar las estrategias de afrontamiento en relación al nivel de estrés por las nuevas condiciones de readaptación ante la modalidad virtual para la continuidad de los procesos académicos en estudiantes de octavo semestre del Programa de Psicología de la Universidad Simón Bolívar, Barranquilla, por el desencadenante repentino del virus Covid-19. Método: se basó en un estudio no experimental, con un diseño cuantitativo, con la aplicación de una encuesta transversal aplicada a través de “Google Forms”. Conclusiones: los estudiantes inducidos para encontrar mejor equilibrio y alternativas en su sistema por la nueva modalidad académica virtual, también utilizaron, con el desarrollo de las tecnologías, estrategias de mayor apropiación y “recopilación de información adicional sobre el problema, averiguando más sobre el problema”, lo que les permitió prepararse para el nuevo fenómeno y adquirir una nueva modalidad de enseñanza-aprendiza que antes era invisible
Conditions for innovation, organizational culture and sustainability
Las organizaciones se pueden asumir como el resultado de las necesidades históricas del entorno y de los sistemas sociales en su proceso evolutivo, y su sostenibilidad depende de la capacidad de entender su propia complejidad. Este artículo propone que la dotación de condiciones para la innovación, como expresión de la cultura organizacional, es una opción garante de sostenibilidad y requiere de un proceso no uniforme, ni predecible, es decir, un proceso complejo. Las reflexiones apuntan a que las empresas, para garantizar su sostenibilidad deben encontrar, cuasiequilibrios altamente dinámicos y transitorios, del núcleo de los requerimientos funcionales de las demandas y las capacidades estructurales de la oferta. Como resultado de esta reflexión se propone que las decisiones instrumentadas a partir de estas capacidades, pueden aceptarse dentro de un rango amplio de estrategias evolutivas eficientes, en un extenso espectro que va desde la adición cercana a los enfoques económicos ortodoxos hasta los actuales de innovación.Organizations can be assumed as the result of historic needs found in a certain environment and in the evolutionary process of social systems, hence, their sustainability depends on the capacity of understanding their own complexities. This paper proposes that the provision of conditions for innovation, as an expression of organizational structure, is an option that ensures sustainability and requires a non-uniform non-predictable process, meaning by this a complex process. The analysis suggests that in order for companies to ensure their sustainability, they must find some sort of highly dynamic and transitory equilibrium for the core of the functional requirements from the demand side and the structural capacities for the supply. As a result, this reflection proposes that those decisions instrumented parting from these capacities, can be accepted within a broad range of efficient evolutionary strategies within a broad spectrum that goes from following orthodox economic methods as well as current innovation ones. As organizações podem assumir como o resultado das necessidades histórica do entorno e dos sistemas de segurança social em seu processo evolutivo, e a sua sustentabilidade depende da capacidade de compreender a sua própria complexidade. Este artigo propõe que a dotação de condições para a inovação, como uma expressão da cultura organizacional, é uma opção garante da sustentabilidade e requer um processo não-uniforme, nem previsível, ou seja, um processo complexo. As reflexões sugerem que as empresas, de modo a garantir a sua sustentabilidade deve encontrar, quase equilíbrios altamente dinâmico e transitório, do núcleo dos requisitos funcionais de demandas e recursos estruturais da oferta. Como resultado desta reflexão, propõe-se que as decisões implementadas por essas capacidades, podem ser aceitos dentro de uma vasta gama de eficientes estratégias evolutivas, em um amplo espectro que vai desde a adição próximas aos enfoques económicos ortodoxas até os atuais de inovação.
ETHNICITY AND MULTIPLE SCLEROSIS PREVALENCE IN EAST LONDON
BackgroundThere is a perceived consensus that the incidence and prevalence rates of MS in countries with a White majority are lower in the minority ethnic population than in the White population. Often-cited UK-based studies relevant to this were conducted over twenty years ago. In our study we update the UK-based literature.MethodsElectronic records from GPs in the four innermost east London boroughs were queried for the number of patients with an MS diagnosis, grouped by ethnicity, into 5-year age bands. Compared against total registered GP patients in the area (c.900K), we calculated the age-standardised MS prevalence separately, for White, Black and South Asian populations.ResultsOverall prevalence was 111 per 100K (152 for women, 70 for men). This was 180, 74, and 29 for the White, Black and South Asian populations respectively. The sex ratios (female:male) were 2.2:1, 2.1:1 and 2.8:1 respectively.ConclusionInner east London is an ideal area to study ethnicity-specific prevalence, with a population that is 36% White, 16% Black, 30% South Asian and 18% Other. MS prevalence was considerably lower amongst Black and South Asian populations, compared to the White population, by 59% and 84% respectively. Our findings are consistent with previous studies.</jats:sec
Non-Recognition-of-BTH4, an Arabidopsis Mediator Subunit Homolog, Is Necessary for Development and Response to Salicylic Acid
[EN] Salicylic acid (SA) signaling acts in defense and plant development. The only gene demonstrated to be required for the response to SA is Arabidopsis thaliana NON-EXPRESSER OF PATHOGENESIS-RELATED GENE 1 (NPR1), and npr1 mutants are insensitive to SA. By focusing on the effect of analogs of SA on plant development, we identified mutants in additional genes acting in the SA response. In this work, we describe a gene necessary for the SA Non-Recognition-of-BTH4 (NRB4). Three nrb4 alleles recovered from the screen cause phenotypes similar to the wild type in the tested conditions, except for SA-related phenotypes. Plants with NRB4 null alleles express profound insensitivity to SA, even more than npr1. NRB4 null mutants are also sterile and their growth is compromised. Plants carrying weaker nrb4 alleles are also insensitive to SA, with some quantitative differences in some phenotypes, like systemic acquired resistance or pathogen growth restriction. When weak alleles are used, NPR1 and NRB4 mutations produce an additive phenotype, but we did not find evidence of a genetic interaction in F1 nor biochemical interaction in yeast or in planta. NRB4 is predicted to be a subunit of Mediator, the ortholog of MED15 in Arabidopsis. Mechanistically, NRB4 functions downstream of NPR1 to regulate the SA response.This work was supported by the "Ministerio de Economia y Competitividad" (MINECO) of Spain (Grant BIO201018896 to P.T., a Junta de Ampliacion de Estudios-Consejo Superior de Investigaciones Cientificas Fellowship to J.V.C., and a Formacion del Personal Investigador-MINECO to A.D.) and "Generalitat Valenciana" of Spain (Grant ACOMP/2012/105 to P.T.). We appreciate the opinions and generous help of Jeff Dangl and Pablo Vera with the article as well as the revision of Philippa Borrill.Canet Perez, JV.; Dobón Alonso, A.; Tornero Feliciano, P. (2012). Non-Recognition-of-BTH4, an Arabidopsis Mediator Subunit Homolog, Is Necessary for Development and Response to Salicylic Acid. Plant Cell. 24(10):4220-4235. https://doi.org/10.1105/tpc.112.103028S42204235241
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