Literatura académica sobre el tema "Minimum barrier distance"
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Artículos de revistas sobre el tema "Minimum barrier distance"
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Strand, Robin, Krzysztof Chris Ciesielski, Filip Malmberg y Punam K. Saha. "The minimum barrier distance". Computer Vision and Image Understanding 117, n.º 4 (abril de 2013): 429–37. http://dx.doi.org/10.1016/j.cviu.2012.10.011.
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Zhang, Jing Mao y Yan Xia Shen. "Spectral segmentation via minimum barrier distance". Multimedia Tools and Applications 76, n.º 24 (20 de febrero de 2017): 25713–29. http://dx.doi.org/10.1007/s11042-017-4473-8.
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Džambas, Tamara, Saša Ahac y Vesna Dragčević. "The Influence of Visibility Conditions in Horizontal Road Curves on the Efficiency of Noise Protection Barriers". Romanian Journal of Transport Infrastructure 2, n.º 2 (1 de diciembre de 2013): 22–32. http://dx.doi.org/10.1515/rjti-2015-0016.
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Abstract Ensuring sufficient visibility on planned roads by sight distance testing is an integral part of every project, but problems with visibility can emerge when noise barriers are erected on existing roads. Namely, in order to provide sufficient noise protection, high noise barriers are often placed at minimum distance from the carriageway edge, and additional visibility testing in most cases is not carried out. Research described in this paper consists of stopping sight distance tests conducted by means of specialized road design software MX Road, and noise barrier optimization conducted by means of specialized noise prediction software LimA using static noise calculation method RLS 90. The aim of this research is to establish whether the required stopping sight distance on road sections where minimum design parameters are applied can be achieved if the noise barrier is placed at minimum distance from the carriageway edge, and to establish whether the optimized dimensions of planned noise protection barrier will change if the barrier is placed on larger distance from the noise source, which is, in this case, the existing road.
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Ciesielski, Krzysztof Chris, Robin Strand, Filip Malmberg y Punam K. Saha. "Efficient algorithm for finding the exact minimum barrier distance". Computer Vision and Image Understanding 123 (junio de 2014): 53–64. http://dx.doi.org/10.1016/j.cviu.2014.03.007.
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Ôn Vũ Ngọc, Minh, Nicolas Boutry, Jonathan Fabrizio y Thierry Géraud. "A minimum barrier distance for multivariate images with applications". Computer Vision and Image Understanding 197-198 (agosto de 2020): 102993. http://dx.doi.org/10.1016/j.cviu.2020.102993.
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Tu, Zhengzheng, Linlin Guo, Chenglong Li, Ziwei Xiong y Xiao Wang. "Minimum Barrier Distance-Based Object Descriptor for Visual Tracking". Applied Sciences 8, n.º 11 (13 de noviembre de 2018): 2233. http://dx.doi.org/10.3390/app8112233.
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In most visual tracking tasks, the target is tracked by a bounding box given in the first frame. The complexity and redundancy of background information in the bounding box inevitably exist and affect tracking performance. To alleviate the influence of background, we propose a robust object descriptor for visual tracking in this paper. First, we decompose the bounding box into non-overlapping patches and extract the color and gradient histograms features for each patch. Second, we adopt the minimum barrier distance (MBD) to calculate patch weights. Specifically, we consider the boundary patches as the background seeds and calculate the MBD from each patch to the seed set as the weight of each patch since the weight calculated by MBD can represent the difference between each patch and the background more effectively. Finally, we impose the weight on the extracted feature to get the descriptor of each patch and then incorporate our MBD-based descriptor into the structured support vector machine algorithm for tracking. Experiments on two benchmark datasets demonstrate the effectiveness of the proposed approach.
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Yang, Zhi-yuan y Bin Wu. "Minimum barrier distance based tracking via spatio-temporal context learning". Optoelectronics Letters 15, n.º 1 (enero de 2019): 75–80. http://dx.doi.org/10.1007/s11801-019-8090-9.
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Wang, Anzhi y Minghui Wang. "RGB-D Salient Object Detection via Minimum Barrier Distance Transform and Saliency Fusion". IEEE Signal Processing Letters 24, n.º 5 (mayo de 2017): 663–67. http://dx.doi.org/10.1109/lsp.2017.2688136.
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NAZAROV, V. N., K. YU SAMSONOV y E. G. EKOMASOV. "ONE-DIMENSIONAL DYNAMICS OF THE DOMAIN BOUNDARY IN A SEVEN-LAYER FERROMAGNETIC STRUCTURE". Izvestia Ufimskogo Nauchnogo Tsentra RAN, n.º 1 (31 de marzo de 2023): 19–23. http://dx.doi.org/10.31040/2222-8349-2023-0-1-19-23.
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The dynamics of the domain boundary is considered using the example of a seven-layer ferromagnetic structure with three thin and four wide magnetic layers. The structure of the domain boundary is represented as a kink solution of the sine-Gordon equation. The equation of motion for magnetization was solved numerically using an explicit scheme. The discretization of the equation was carried out according to a standard five-point scheme of the "cross" type. The paper shows the features of the dynamics of the domain boundary in a multilayer magnetic system in the presence of thin magnetic layers with an increased value of the magnetic anisotropy constant. Thin layers with an increased value of the magnetic anisotropy constant compared to the homogeneous state represent potential barriers to the moving domain boundary. Thin layers with an increased magnitude of magnetic anisotropy compared to a homogeneous state represent potential barriers to a moving domain boundary. A diagram of possible scenarios of the dynamics of the domain boundary is constructed depending on the initial velocity of its movement and the distance between three thin magnetic layers. The maximum value of the kink velocity for reflection from all potential barriers, depending on their size, is obtained. With an increase in the height and width of the barrier, the value of such a threshold maximum reflection velocity of the domain boundary increases nonlinearly. With a sufficiently high barrier height, there is already an almost linear dependence on the width of this threshold velocity. With a slight increase in the speed of movement of the domain boundary, the kink can pass through the first barrier, but it is reflected from the second barrier. There is also a case of kink oscillation between the second and third potential barriers. Such fluctuations are clearly inharmonious. The dependence of the threshold velocity on the distance between the barriers is obtained. As the distance between the barriers increases, the threshold speed value tends to a value equal to the threshold speed for one barrier. In the work, the minimum value of the speed of the domain boundary of the passage of all layers, depending on the parameters of potential barriers, is obtained. It is also found that there is a critical distance separating the dynamics of the domain boundary into two regions with qualitatively different behavior of the system.
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Chang, C., M. J. Chung y Z. Bien. "Collision-free motion planning for two articulated robot arms using minimum distance functions". Robotica 8, n.º 2 (abril de 1990): 137–44. http://dx.doi.org/10.1017/s0263574700007712.
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SummaryThis paper presents a collision-free motion planning method of two articulated robot arms in a three dimensional common work space. Each link of a robot arm is modeled by a cylinder ended by two hemispheres, and the remaining wrist and hand is modeled by a sphere. To describe the danger of collision between two modeled objects, minimum distance functions, which are defined by the Euclidean norm, are used. These minimum distance functions are used to describe the constraints that guarantee no collision between two robot arms. The collision-free motion planning problem is formulated as a pointwise constrained nonlinear minimization problem, and solved by a conjugate gradient method with barrier functions. To improve the minimization process, a simple grid technique is incorporated. Finally, a simulation study is presented to show the significance of the proposed method.
Tesis sobre el tema "Minimum barrier distance"
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On, Vu Ngoc Minh. "A new minimum barrier distance for multivariate images with applications to salient object detection, shortest path finding, and segmentation". Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS454.
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Les représentations hiérarchiques d’images sont largement utilisées dans le traitement d’images pour modéliser le contenu d’une image par un arbre. Une hiérarchie bien connue est l’arbre des formes (AdF) qui encode la relation d’inclusion entre les composants connectés à partir de différents niveaux de seuil. Ce genre d’arbre est auto-duale et invariant de changement de contraste, ce qu’il est utilisé dans de nombreuses applications de vision par ordinateur. En raison de ses propriétés, dans cette thèse, nous utilisons cette représentation pour calculer la nouvelle distance qui appartient au domaine de la morphologie mathématique. Les transformations de distance et les cartes de saillance qu’elles induisent sont généralement utilisées dans le traitement d’images, la vision par ordinateur et la reconnaissance de formes. L’une des transformations de distance les plus couramment utilisées est celle géodésique. Malheureusement, cette distance n’obtient pas toujours des résultats satisfaisants sur des images bruyantes ou floues. Récemment, une nouvelle pseudo-distance, appelée distance de barrière minimale (MBD), plus robuste aux variations de pixels, a été introduite. Quelques années plus tard, Géraud et al. ont proposé une bonne approximation rapide de cette distance : la pseudodistance de Dahu. Puisque cette distance a été initialement développée pour les images en niveaux de gris, nous proposons ici une extension de cette transformation aux images multivariées ; nous l’appelons vectorielle Dahu pseudo-distance. Cette nouvelle distance est facilement et efficacement calculée grâce à à l’arbre multivarié des formes (AdFM). Nous vous proposons une méthode de calcul efficace cette distance et sa carte de saillants déduits dans cette thèse. Nous enquêtons également sur le propriétés de cette distance dans le traitement du bruit et du flou dans l’image. Cette distance s’est avéré robuste pour les pixels invariants. Pour valider cette nouvelle distance, nous fournissons des repères démontrant à quel point la pseudo-distance vectorielle de Dahu est plus robuste et compétitive par rapport aux autres distances basées sur le MB. Cette distance est prometteuse pour la détection des objets saillants, la recherche du chemin le plus court et la segmentation des objets. De plus, nous appliquons cette distance pour détecter le document dans les vidéos. Notre méthode est une approche régionale qui s’appuie sur le saillance visuelle déduite de la pseudo-distance de Dahu. Nous montrons que la performance de notre méthode est compétitive par rapport aux méthodes de pointe de l’ensemble de données du concours Smartdoc 2015 ICDARHierarchical image representations are widely used in image processing to model the content of an image in the multi-scale structure. A well-known hierarchical representation is the tree of shapes (ToS) which encodes the inclusion relationship between connected components from different thresholded levels. This kind of tree is self-dual, contrast-change invariant and popular in computer vision community. Typically, in our work, we use this representation to compute the new distance which belongs to the mathematical morphology domain. Distance transforms and the saliency maps they induce are generally used in image processing, computer vision, and pattern recognition. One of the most commonly used distance transforms is the geodesic one. Unfortunately, this distance does not always achieve satisfying results on noisy or blurred images. Recently, a new pseudo-distance, called the minimum barrier distance (MBD), more robust to pixel fluctuation, has been introduced. Some years after, Géraud et al. have proposed a good and fast-to-compute approximation of this distance: the Dahu pseudodistance. Since this distance was initially developed for grayscale images, we propose here an extension of this transform to multivariate images; we call it vectorial Dahu pseudo-distance. This new distance is easily and efficiently computed thanks to the multivariate tree of shapes (MToS). We propose an efficient way to compute this distance and its deduced saliency map in this thesis. We also investigate the properties of this distance in dealing with noise and blur in the image. This distance has been proved to be robust for pixel invariant. To validate this new distance, we provide benchmarks demonstrating how the vectorial Dahu pseudo-distance is more robust and competitive compared to other MB-based distances. This distance is promising for salient object detection, shortest path finding, and object segmentation. Moreover, we apply this distance to detect the document in videos. Our method is a region-based approach which relies on visual saliency deduced from the Dahu pseudo-distance. We show that the performance of our method is competitive with state-of-the-art methods on the ICDAR Smartdoc 2015 Competition dataset
Capítulos de libros sobre el tema "Minimum barrier distance"
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Strand, Robin, Krzysztof Chris Ciesielski, Filip Malmberg y Punam K. Saha. "The Minimum Barrier Distance: A Summary of Recent Advances". En Discrete Geometry for Computer Imagery, 57–68. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-66272-5_6.
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Strand, Robin, Filip Malmberg, Punam K. Saha y Elisabeth Linnér. "The Minimum Barrier Distance – Stability to Seed Point Position". En Advanced Information Systems Engineering, 111–21. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-319-09955-2_10.
Texto completoActas de conferencias sobre el tema "Minimum barrier distance"
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Qiong Wang, Lu Zhang y Kidiyo Kpalma. "Fast filtering-based temporal saliency detection using Minimum Barrier Distance". En 2017 IEEE International Conference on Multimedia & Expo Workshops (ICMEW). IEEE, 2017. http://dx.doi.org/10.1109/icmew.2017.8026330.
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Qiu, Mingming, Yan Wang y Zhan Chen. "Investigation on insulating barrier and cover for live working and effect on the minimum approach distance in the 110kV Substation". En 2016 IEEE International Conference on High Voltage Engineering and Application (ICHVE). IEEE, 2016. http://dx.doi.org/10.1109/ichve.2016.7800781.
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Kostecki, Jodi, Matthew Edel y John Montoya. "Importance of Connections in High-Pressure Barricade Design". En ASME 2018 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/pvp2018-84765.
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High pressure testing and operation of industrial tools and equipment can be hazardous to personnel and property in the event of an accidental mechanical failure or release of contained pressure. Hazard barricades are commonly installed around equipment to protect nearby personnel or property from projectile impacts or overpressure. The ASME Standard PCC-2 “Repair of Pressure Equipment and Piping” allows the use of hazard barricades for this purpose when a safe standoff distance cannot be satisfied, but it currently provides minimal guidance for engineered design. Other references provide guidance for preventing projectile perforation of a barricade. While perforation prevention is a key component of shield design, properly anchoring a shield and inter-connecting the shield components will make the difference between an effective barricade application and a barrier that could potentially compound the consequences of an accidental failure. This paper investigates the importance of engineered structural connections and consideration of global structural response in the design of protective barricades. The structural models focus on impact loading of steel plates and bolted connections, and the results are directly compared to test results in terms of effective barrier response.
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Miers, Kevin T., Daniel L. Prillaman y Nausheen M. Al-Shehab. "Optimized Impact Mitigation Barriers for Insensitive Munitions Compliance of a 120mm Warhead". En 2019 15th Hypervelocity Impact Symposium. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/hvis2019-105.
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Abstract The U.S. Army Combat Capabilities Development Command (CCDC) Armaments Center at Picatinny Arsenal, NJ is working to develop technologies to mitigate the violent reaction of a 120 mm warhead, loaded with an aluminized HMX-based enhanced blast explosive, when subjected to the NATO Insensitive Munitions (IM) Fragment Impact (FI) test. As per NATO STANAG 4496, FI testing is conducted at 8300±300 ft/s with a 0.563” diameter, L/D~1, 160˚ conical nosed mild steel fragment. Reaction violence resulting from FI can be mitigated by the use of liners or barriers applied to the munition itself or its packaging, commonly referred to as a Particle Impact Mitigation Sleeves (PIMS). Previous development efforts for this item focused on a lightweight plastic warhead support which was able to reduce the severity of the input shock sufficiently to prevent high order detonation. However, violent sub-detonative responses were still observed which occurred over several hundred microseconds, consumed part of the explosive charge, and ejected hazardous debris over large distances. These responses are driven by rapid combustion coupled with damage to the explosive as well as mechanical confinement. Quantitative modeling of these scenarios is a challenging active research area. Prior experimental results and modeling guidance have shown that mitigation of these reactions requires a more substantial reduction in the overall mechanical insult to the explosive. In particular, steel and aluminum PIMS have been able to efficiently provide the necessary fragment velocity reduction, breakup and dispersion in typical packaging applications. Packaged warheads were tested at the GD-OTS Rock Hill facility with several PIMS designs incorporated into the ammunition containers. Several designs were demonstrated to provide benign reactions with minimal added weight. Future iterations will attempt to further improve the design using advanced lightweight barrier materials.
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Le-Naour, Frederic, Antoine Marret, Kenny MacLeod, Romain Vivet y Ida Margaretha Aglen. "Electrical & Optical Double Barrier Qualification and Implementation on FENJA Electrically Trace Heated Pipe-in-Pipe Project". En Offshore Technology Conference. OTC, 2021. http://dx.doi.org/10.4043/31214-ms.
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Abstract This paper provides an overview of the work completed to design, qualify, manufacture and integrate electrical and optical double barrier penetrators with the Electrically Trace Heated Pipe-in-Pipe (ETH-PiP) as part of the Neptune Energy Fenja Development Project. Typical subsea penetrator systems in the oil and gas industry, such as pumps, compressors and X-trees are designed to be retrievable, to enable periodic refurbishment as well as providing the option for replacement, if required. However, the ETH-PiP architecture makes retrieval of system components complicated and uneconomical. Both the electrical and optical dual barrier penetrator system designs have to comply with a set of ETH-PiP specific criteria, such as to be maintenance free over a 25 years service life, prevent water ingress to the pipeline, provide pressure containment for operational media (in an unlikely scenario where the inner pipe bursts) and guarantee minimum footprint to allow an optimum integration onto the Pipeline End Termination (PLET) structure. In addition, the electrical system has to comply with a medium voltage rating (i.e. 5.0/8.7kV) to ensure a wide range of possible ETH-PiP architectures. The optical system has to maintain insertion loss below 0.5dB and a back reflection below -45dB to comply with the stringent requirements of distributed temperature monitoring sensor system over long distances. The qualification program of the electrical dual barrier penetrator system was performed in accordance with IEC 60502-4 and SEPS-SP-1001. A tailor made sequence had to be developed for the optical system, based on guidance from SEAFOM-TSD-01, considering that the system partly falls outside the associated standard application. The electrical dual barrier penetrator system qualification sequence was developed in two phases; firstly, the electrical transition contacts in the feedthrough chamber were qualified in accordance with IEC 60502-4 and secondly, four electrical double barrier penetrator prototypes were manufactured to allow the completion of the qualification sequence defined as per SEPS-SP-1001. The optical dual barrier penetrator system qualification employed the manufacturing of three prototypes to execute the pre-defined qualification sequence. Following the individual qualification of the electrical and optical dual barrier penetrator systems, subsequent welding and full-scale assembly trials were performed to ensure that the maximum allowable temperatures within the penetrators would not be exceeded during welding to the PLET, and to proof test the assembly procedure. Electrical verification testing was also undertaken during these trials to verify that the integrity of the penetrators had been maintained during the assembly and that the PLET arrangement did not give rise to any electrical stresses that could result in excessive deterioration of the penetrators. Integration of the four electrical and two optical dual barrier penetrator systems to the project PLET was completed in Q1 2020, with the actual subsea installation of the first ETH-PiP section including the PLET in Q3 2020.
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Feist, J. P., P. Y. Sollazzo, S. Berthier, B. Charnley y J. Wells. "Application of an Industrial Sensor Coating System on a Rolls-Royce Jet Engine for Temperature Detection". En ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-69923.
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Thermal barrier coatings are used to reduce the actual working temperature of the high pressure turbine blade metal surface and hence permit the engine to operate at higher more efficient temperatures. Sensor coatings are an adaptation of existing thermal barrier coatings to enhance their functionality, such that they not only protect engine components from the high temperature gas, but can also measure the material temperature accurately and determine the health of the coating e.g. ageing, erosion and corrosion. The sensing capability is introduced by embedding optically active materials into the thermal barrier coatings and by illuminating these coatings with excitation light phosphorescence can be observed. The phosphorescence carries temperature and structural information about the coating. Accurate temperature measurements in the engine hot section would eliminate some of the conservative margins which currently need to be imposed to permit safe operation. A 50K underestimation at high operating temperatures can lead to significant pre-mature failure of the protective coating and loss of integrity. Knowledge of the exact temperature could enable the adaptation of the most efficient coating strategies using the minimum amount of air. The integration of an on-line temperature detection system would enable the full potential of thermal barrier coatings to be realised due to improved accuracy in temperature measurement and early warning of degradation. This in turn will increase fuel efficiency and reduce CO2 emissions. Application: This paper describes the implementation of a sensor coating system on a Rolls-Royce jet engine. The system consists of three components: industrially manufactured robust coatings, advanced remote detection optics and improved control and readout software. The majority of coatings were based on yttria stabilized zirconia doped with Dy (dysprosium) and Eu (europium), although other coatings made of yttrium aluminium garnet were manufactured as well. Coatings were produced on a production line using atmospheric plasma spraying. Parallel tests at Didcot power station revealed survivability of specific coatings in excess of 4,500 effective operating hours. It is deduced that the capability of these coatings is in the range of normal maintenance schedules of industrial gas turbines of 24,000 hours or even longer. An advanced optical system was designed and manufactured permitting easy scanning of coated components and also the detection of phosphorescence on rotating turbine blades (13k RPM) at stand-off distances of up to 400mm. Successful temperature measurements were taken from the nozzle guide vanes (hot), the combustion chamber (noisy) and the rotating turbine blades (moving) and compared with thermocouple and pyrometer installations for validation purposes.
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Feist, J. P., P. Y. Sollazzo, S. Berthier, B. Charnley y J. Wells. "Precision Temperature Detection Using a Phosphorescence Sensor Coating System on a Rolls-Royce Viper Engine". En ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-69779.
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By adapting existing thermal barrier coatings a sensor coating has been developed to enhance their functionality, such that they not only protect engine components from the high temperature gas, but can now also measure the material temperature accurately and the health of the coating e.g. ageing, erosion and corrosion. The sensing capability is introduced by embedding optically active materials into the thermal barrier coating and by illuminating these coatings with excitation light phosphorescence can be observed. The phosphorescence carries temperature and structural information about the coating. Knowledge of the exact temperature could enable the design of advanced cooling strategies in the most efficient way using a minimum amount of air. The integration of an on-line temperature detection system would enable the full potential of thermal barrier coatings to be realized due to improved accuracy in temperature measurement and early warning of degradation. This in turn will increase fuel efficiency and reduce CO2 emissions. Application: The work carried out included the successful implementation of a sensor coating system on a Rolls-Royce Viper engine. The system consists of three components: industrially-manufactured robust coatings, advanced remote detection optics and improved control and readout software. The majority of coatings were based on yttria stabilized zirconia doped with Dy, although other coatings made of yttrium aluminium garnet were manufactured as well. Coatings were produced on a production line using atmospheric plasma spraying. Parallel tests at Didcot power station revealed the durability of specific coatings in excess of 4,500 effective operating hours. It is expected that the capability of these coatings is in the range of normal maintenance schedules of industrial gas turbines of 24,000hrs or even longer. An optical energy transfer system was designed and developed permitting scanning of coated components and also the detection of phosphorescence on rotating turbine blades (13,000 RPM) at probe-to-target distances of up to 400mm. The online measurement system demonstrated precision (around ±5K) comparable to commercial thermocouples and has shown calibration accuracy of ±4K. Transient temperatures were tracked at maximum at 8Hz which is fast enough to follow a typical power generation gas turbine. Repeatable measurements were successfully taken from the nozzle guide vanes (hot), the combustion chamber (noisy) and the rotating turbine blades (moving) and compared with thermocouple and pyrometer installations.
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Khan, Mohammed Yunus, Mohammed Taha Al-Murayri, Satish Kumar Eadulapally, Haya Ebrahim Al-Mayyan, Deema Alrukaibi y Anfal Al-Kharji. "Strategies to Design Fit for Purpose EOR Pilots by Integrating Dynamic and Static Data in a Highly Heterogeneous Oolitic Carbonate Reservoir". En International Petroleum Technology Conference. IPTC, 2024. http://dx.doi.org/10.2523/iptc-23708-ms.
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Abstract Umm Gudair Minagish Oolite is a heterogeneous carbonate reservoir with random intermittent micritic units forming low permeability barriers to fluid flow. The facies, permeability variations and barriers have limited lateral extension. Therefore, different strategies need to be designed to implement accelerated fit-for-purpose polymer injectivity pilots without compromising the proper assessment of key parameters such as polymer injectivity, polymer adsorption, resistance factor, in-situ rheological properties, volumetric sweep efficiency, incremental oil gains, and polymer breakthrough. The field is divided into geological sub-regions based on reservoir scale heterogeneities by integrating static and dynamic data. The pilot location for each region is selected such that it shows minimal variations in reservoir properties in terms of facies, permeability, and extension of barriers. Simulation results were analyzed for each considered pilot area based on injectivity, pilot duration, oil peak rate, overall polymer performance and economics. Using these parameters, pilot design and locations are ranked while emphasizing the need to reduce the number of additional required wells to de-risk polymer flooding as a precursor for commercial development. Based on time-lapse saturation logs different sweep zones are identified and correlated with the facies. The maximum oil swept is observed in clean Grainstones. The facies characterization along with production data were used for defining the geological sub-regions. The pilot performance was analyzed using high-resolution numerical simulation for each geological sub-region, using high-salinity produced water. Thereafter, pilot design and locations were ranked based on dynamic performance. The best performing polymer injectivity pilot, with limited well requirements, was selected for field implementation including one injector and one producer with an inter-well distance of 80m. The envisioned pilot duration is 6 months showing promising incremental oil gains from polymer injection compared to water injection. Besides incremental oil gains, the utilization of produced water for polymer injection improves operational efficiency and cost optimization.
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Khokhar, Saad Yousuf, Mustansar Raza, Hossam Elmoneim, Arif Yousuf, Rameez Anwar, Saqib Jah Temuri, Salman Saeed Muhammad, Afnan Dar Ahmed y Kamil Shehzad. "Is Fluidic Oscillator a Game Changer in Improving Well Productivity? An Analysis with Case Studies". En ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/211144-ms.
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Abstract The case studies performed in the Middle East and South Asia region shared in the paper reflect the requirement of production/injection enhancement in challenging downhole conditions. Larger tubing diameter, limitations of minimum ID to deploy bigger OD tools, low bottom hole pressures, and requirement of high annular and jetting velocities are often demanded in CT clean-out operations. The advancements in coiled tubing metallurgies to intervene in complex wellbore geometries and the precision of downhole simulators to predict on-site scenarios have put more pressure on the efficiency of downhole tools in production enhancement services. Thus, the case studies required a tool that could overcome the barriers offered by incumbent technologies. It is confirmed from laboratory tests that a standoff of eight times the orifice diameter and fluid velocity of 200 ft/sec is required to remove moderate to hard deposits from wellbores. Conventional jetting tools have a standoff distance of more than 40 times and fluid velocities are far below 200 ft/sec thus objectives of CT intervention are often compromised. Moreover, the effectiveness of conventional tools for critical matrix in the stimulation operations is barely minimum as the jetting effect diverges from the jetting stream. A new type of fluidic oscillator was utilized in the case studies. Unlike pulsating effects created by 1st generation of the fluidic oscillators, the SFO type oscillator had triple jetting action namely, Helix jetting, Pulses Jetting, and Cavitation jetting which was equally effective for in-wellbore and near- wellbore regions. Paper also explains the working mechanism of the tool and demonstrates its ability to remove the skin in the critical matrix The results of the clean-out with SFO technology were beyond expectations. It reduced the operating times to two-thirds of conventional operations, which led to cost savings in all the case studies by an average of 35%. Moreover, it increased the efficiency of treatment fluids which resulted in the reduction of waste of additives, and the requirement of extra efforts to dispose of excess materials at wellsite. Also, jetting effectiveness caused an increase in production/injection from 30%- to 250% This is the first technology that uses cavitation jetting in oilfield services and the first to use aforesaid jetting actions altogether in one tool. The technology adopted in the case studies doesn't have moving or rotating parts, thus eliminating the requirement to pull CT out of the hole for redressing and can perform long operations in one go. It doesn't depend on the centralization of the tool as the jetting effect is passed via kinetic energy through submersed fluids, thus can target deeper depth without limitations of the standoff. It allows a higher flow rate of liquid and gas, thus offering higher energies for clean-out and stimulation operations.
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He, Xingxi y Donald J. Leo. "Monte-Carlo Simulation of Ion Transport at the Polymer-Metal Interface". En ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79765.
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The transport of charge due to electric stimulus is the primary mechanism of actuation for a class of polymeric active materials known as ionomeric polymer transducers. Continuum-based models of ion transport have been developed for the purpose of understanding charge transport due to diffusion and migration. In this work a two dimensional ion hopping model has been built to describe ion transport in ionomeric polymer transducer (IPT) with Monte-Carlo simulation. In the simulation, cations are distributed on 50nm × 50nm × 1nm (or 50nm × 10 nm × 1nm) lattice cells of IPT while the same number of negative charges are uniformly scattered and fixed as background. In the simulation, thermally activated cations are hopping between multiwell energy structures by overcoming energy barriers around with a hopping distance of 1nm during each time step. A step voltage is applied between the electrodes of the IPT. In one single simulation step, coulomb energy, external electric potential energy and intrinsic energy of the material are calculated and added up for the energy wells around the cations. And then hopping rates in every potential hopping direction are obtained. Due to the random nature of the ion transitions, a weighting function from Monte-Carlo algorithm is added in to calculate the ion hopping time. Finally hopping time is compared, the minimum hopping time is chosen and one hopping event is completed. Both system time and ions distribution are updated before the next simulation loop. Periodic boundary conditions are applied when ions hop in the direction perpendicular to the electric field. The influence of the electrodes on both faces of IPT is presented by the method of image charges. The charge density at equilibrium state is compared with the result from a continuum-based model. The property of charge density has charge neutrality over the central part of the membrane and the charge imbalance over boundary layers close to the anode and cathode. Electric field distribution is obtained after charge distribution. After it is demonstrated that ion hopping model leads to the results qualitatively matching the property of IPT, the paper uses the model to analyze the polymer-metal interface when the electrode shape inside transducer varies.