Academic literature on the topic 'Unreliable nar'
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Journal articles on the topic "Unreliable nar"
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McKinnon, Catherine. "Case Study: Writing Unreliable Narrator Will Martin." Narrative 22, no. 3 (2014): 395–416. http://dx.doi.org/10.1353/nar.2014.0022.
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Stevens, Kevin. "“Eccentric Murmurs”: Noise, Voice, and Unreliable Narration in Jane Eyre." Narrative 26, no. 2 (2018): 201–20. http://dx.doi.org/10.1353/nar.2018.0010.
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Sela, Itamar, Haim Ashkenazy, Kazutaka Katoh, and Tal Pupko. "GUIDANCE2: accurate detection of unreliable alignment regions accounting for the uncertainty of multiple parameters." Nucleic Acids Research 43, W1 (2015): W7—W14. http://dx.doi.org/10.1093/nar/gkv318.
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Qi, Lian, and Zuo-Jun Max Shen. "A supply chain design model with unreliable supply." Naval Research Logistics 54, no. 8 (2007): 829–44. http://dx.doi.org/10.1002/nav.20255.
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Rico-Alvarino, Alberto, Roberto Lopez-Valcarce, Carlos Mosquera, and Robert W. Heath. "FER Estimation in a Memoryless BSC With Variable Frame Length and Unreliable ACK/NAK Feedback." IEEE Transactions on Wireless Communications 16, no. 6 (2017): 3661–73. http://dx.doi.org/10.1109/twc.2017.2686845.
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Sahba, Pedram, Bariş Balciog̃lu, and Dragan Banjevic. "Analysis of the finite-source multiclass priority queue with an unreliable server and setup time." Naval Research Logistics (NRL) 60, no. 4 (2013): 331–42. http://dx.doi.org/10.1002/nav.21537.
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Chakravarthy, Srinivas R., and Atul Agarwal. "Analysis of a machine repair problem with an unreliable server and phase type repairs and services." Naval Research Logistics 50, no. 5 (2003): 462–80. http://dx.doi.org/10.1002/nav.10069.
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Narasimhan, Madhumitha, Michelle Gallei, Shutang Tan, et al. "Systematic analysis of specific and nonspecific auxin effects on endocytosis and trafficking." Plant Physiology 186, no. 2 (2021): 1122–42. http://dx.doi.org/10.1093/plphys/kiab134.
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Abstract The phytohormone auxin and its directional transport through tissues are intensively studied. However, a mechanistic understanding of auxin-mediated feedback on endocytosis and polar distribution of PIN auxin transporters remains limited due to contradictory observations and interpretations. Here, we used state-of-the-art methods to reexamine the auxin effects on PIN endocytic trafficking. We used high auxin concentrations or longer treatments versus lower concentrations and shorter treatments of natural indole-3-acetic acid (IAA) and synthetic naphthalene acetic acid (NAA) auxins to distinguish between specific and nonspecific effects. Longer treatments of both auxins interfere with Brefeldin A-mediated intracellular PIN2 accumulation and also with general aggregation of endomembrane compartments. NAA treatment decreased the internalization of the endocytic tracer dye, FM4-64; however, NAA treatment also affected the number, distribution, and compartment identity of the early endosome/trans-Golgi network, rendering the FM4-64 endocytic assays at high NAA concentrations unreliable. To circumvent these nonspecific effects of NAA and IAA affecting the endomembrane system, we opted for alternative approaches visualizing the endocytic events directly at the plasma membrane (PM). Using total internal reflection fluorescence microscopy, we saw no significant effects of IAA or NAA treatments on the incidence and dynamics of clathrin foci, implying that these treatments do not affect the overall endocytosis rate. However, both NAA and IAA at low concentrations rapidly and specifically promoted endocytosis of photo-converted PIN2 from the PM. These analyses identify a specific effect of NAA and IAA on PIN2 endocytosis, thus, contributing to its polarity maintenance and furthermore illustrate that high auxin levels have nonspecific effects on trafficking and endomembrane compartments.
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Faszcza, Michał Norbert. "Problemy metodologiczne w badaniach nad Celtami i celtyckością." Studia Europaea Gnesnensia, no. 11 (January 1, 2015): 55–83. http://dx.doi.org/10.14746/seg.2015.11.3.
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In the studies devoted to Celts so far, researchers have tried to define “Celticness” based on two criteria: their material culture and language. Another element which tended to be employed was the argument of terminology used by antique authors. At present, we know that the sense of ethnic identification may have been independent of those factors. This led to a genuine “scientific revolution”, which resulted in the exclusion of Ireland and northern Britain from the circle of Celtic culture. Consequently, the question in which cases one can speak of “Celticness” has become relevant yet again. The author is of the opinion that decisive significance should be attributed to self-identification of given tribes, although sources rarely provide information in that respect. Depending on the remaining criteria tends to be greatly unreliable, given that they were are a modern concept and as such are subject to manipulation. A comfortable, though exceedingly rare situation is their joint occurrence. For this reason the author is inclined to give priority to the language criterion, yet only when the faulty terminology relation to the so-called Q-Celtic and P-Celtic languages is abandoned. Despite the fact that Irish civilisation has been demonstrated to have been non-Celtic, the obsolete terminology is still in use, as a result of which the linguistic criterion cannot perform its function effectively.
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Jin, Luchao, Zhitao Li, Ahmad Jamili, et al. "An Analytical Solution for Three-Component, Two-Phase Surfactant Flooding Dependent on the Hydrophilic/Lipophilic-Difference Equation and the Net-Average-Curvature Equation of State." SPE Journal 22, no. 05 (2017): 1424–36. http://dx.doi.org/10.2118/185946-pa.
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Summary Microemulsion phase behavior is crucial to surfactant flooding performance and design. In previous studies, analytical/numerical solutions for surfactant flooding were developed dependent on the classical theory of multicomponent/multiphase displacement and empirical microemulsion phase-behavior models. These phase-behavior models were derived from empirical correlations for component-partition coefficients or from the Hand-rule model (Hand 1930), which empirically represents the ternary-phase diagram. These models may lack accuracy or predictive abilities, which may lead to improper formulation design or unreliable recovery predictions. To provide a more-insightful understanding of the mechanisms of surfactant flooding, we introduced a novel microemulsion phase-behavior equation of state (EOS) dependent on the hydrophilic/lipophilic-difference (HLD) equation and the net-average curvature (NAC) model, which is called HLD-NAC EOS hereafter. An analytical model for surfactant flooding was developed dependent on coherence theory and this novel HLD-NAC EOS for two-phase three-component displacement. Composition routes, component profile along the core, and oil recovery can be determined from the analytical solution. The analytical solution was validated against numerical simulation as well as experimental study. This HLD-NAC EOS based analytical solution enables a systematic study of the effects of phase-behavior-dependent variables on surfactant-flooding performance. The effects of solution gas and pressure on microemulsion phase behavior were investigated. It was found that an increase of solution gas and pressure would lead to enlarged microemulsion bank and narrowed oil bank. For a surfactant formulation designed at standard conditions, the analytical solution was able to quantitatively predict its performance under reservoir conditions.
Dissertations / Theses on the topic "Unreliable nar"
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Puxan, Oliva Marta. "Narrative Voice and Racial Stereotypes in the Modern Novel: Joseph Conrad's Lord Jim and William Faulkner's Absalom, Absalom!" Doctoral thesis, Universitat Pompeu Fabra, 2010. http://hdl.handle.net/10803/7454.
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Aquesta tesi vol demostrar que Joseph Conrad i William Faulkner, en les novel·les Lord Jim i Absalom, Absalom! respectivament, reflexionen sobre la credibilitat de la veu en la ficció i del discurs racial per mitjà de l'exploració tècnica de la veu narrativa i dels estereotips racials. Nascuda de les crisis històriques que giren al voltant de les relacions racials, patides al si de l'Imperi Britànic de finals del segle XIX i al Sud dels Estats Units durant la dècada de 1930, l'articulació d'aquests dos aspectes en les novel·les permet una representació de les qüestions racials que és innovadora i ambivalent. Certament, la interrogació de la credibilitat dels discursos, tan comú en la novel·la moderna, porta a la sofisticació tant de les estratègies narratives que exploren el problema de la fiabilitat en la ficció com de l'ús dels estereotips racials a dins de la narració, entesos, doncs, com a formes narratives. És justament en l'anàlisi de les correspondències entre els aspectes històrics i els aspectes formals on la tesi troba la manera complexa en què aquestes dues novel·les expressen les tensions racials pròpies dels contextos històrics que les engendren.<br>This dissertation intends to demonstrate that Joseph Conrad's novel Lord Jim and William Faulkner's Absalom, Absalom! explore the narrative strategy of narrative voice, on the one hand, and racial stereotypes, on the other, in order to reflect upon the credibility of voice in fiction as well as the trustworthiness of racial discourse. Emerging from the historical ideological crisis that involved race relations in the late nineteenth-century British Empire, and in the 1930s U.S. South, the blending of these two aspects allowed an alternative and ambivalent representation of racial issues in fiction. The interrogation of credibility, very common in the Modern novel, results in these novels in a sophistication of the strategies that address the problem of narrative reliability, and of the use of racial stereotypes for narrative purposes in other words, their conception as narrative forms. By paying attention to these two aspects, this thesis claims that it is in the analysis of their intertwining where we may find the expression of the historical tension born of complex race relations.
Book chapters on the topic "Unreliable nar"
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Buchwald, Jed Z., and Mordechai Feingold. "Interpreting Words." In Newton and the Origin of Civilization. Princeton University Press, 2012. http://dx.doi.org/10.23943/princeton/9780691154787.003.0008.
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More than three decades separate Isaac Newton’s explorations of astronomical chronology and his youthful engagement with problems of perception and measurement. By the time of his first computations in the area, shortly before the publication of the Opticks, Isaac Newton’s understanding of measurement had been refined through years of experimental and computational experience, not the least of which occurred as he worked on the motions of bodies in fluids during the 1680s. The previous decade had given Newton considerable familiarity with words from the past, and he had slowly developed a highly skeptical attitude toward ancient remarks that did not have a continuous textual ancestry, or that reflected what he considered to be unreliable “poetic fancies.” Thus, aiming to produce a compelling argument grounded in computation for his new chronology, Newton faced a treacherous triple problem: he had first to argue that the words with which he worked were originally produced near the time of the Trojan War; then he had to transform these words into astronomical data; finally, he had to deploy a technique for working with what he rapidly learned was a set of extremely discrepant observations. He labored over these problems until his death. This chapter follows Newton as he transformed words and calculated.
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Colopy, Cheryl. "Introduction." In Dirty, Sacred Rivers. Oxford University Press, 2012. http://dx.doi.org/10.1093/oso/9780199845019.003.0007.
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Red, hand-painted letters in Devanagari script inscribed on a yellow background tell visitors, in Hindi, “This water is as pure as the water from Ganga. Please keep it clean.” The sign is painted on a wall near the entrance to a spring housed in a small temple in the Indian town of Almora. A shiva lingam painted red sits atop the tile roof that shelters a rectangular pool of clear water, embraced on three sides by white stucco walls below street level. Most of the people who come to this spring in the Himalayan foothills of eastern Uttarakhand obediently remove their shoes before descending the stairway to the stone pool. The spring, called a nola in this part of India, is several hundred years old, locals say. Until fairly recently all the water used in this area came from hundreds of springs; some are small ponds like this one, others are spouts or dhara from which water flows. Now many of the springs are contaminated by trash and sewage. New construction destroyed some of them or blocked the sources that fed them. The river that flows at the bottom of the valley below Almora does not have enough water both to support the region’s agriculture and to supply household water for the city of more than forty thousand, where many people are now accustomed to water piped into their homes. Besides, it’s expensive to pump water uphill into the town. Almora will soon have a full-blown water crisis. Already people go to the old springs that are still functioning. They need water because the supply in the city pipes sometimes dwindles; and many still prefer the taste and coldness of the spring water and believe it’s good for their health. The nola and dhara of Almora suggest some of the contradictions in South Asia’s growing water crisis. Traditional systems have been neglected or abandoned, even abused, in favor of the promised convenience of modern ones. But those twentieth-century replacements have sometimes turned out to be unreliable and have left many people unserved.
Conference papers on the topic "Unreliable nar"
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Sasa, Kenji, Daisuke Terada, Shigeaki Shiotani, Nobukazu Wakabayashi, and Teruo Ohsawa. "Current Situation and Difficulty of Wave Forecast From Viewpoint of Ship Management." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-10257.
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Numerical forecasts of weather and oceanography are increasingly common in the field of ship operations due to advances in computer science. However, in some situations, the accuracy of forecasts is too unreliable to ensure safe operations. In the current study, a nationwide questionnaire is used to determine the effectiveness of wave forecasts in enhancing navigation safety. Data analysis is also shown for two cases of failed forecasts in low-pressure weather systems near Japan in the winter. Finally, recommendations are made for improving wave forecasts from the viewpoint of ship operations.
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Benson, Kelly, Jimmy D. Thornton, Douglas L. Straub, E. David Huckaby, and Geo A. Richards. "Flame Ionization Sensor Integrated Into Gas Turbine Fuel Nozzle." In ASME Turbo Expo 2003, collocated with the 2003 International Joint Power Generation Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/gt2003-38470.
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Recent advances in lean premix gas turbine combustion have focused primarily on increasing thermodynamic efficiency, reducing emissions, and minimizing combustion dynamics. The practical limitation on increasing efficiency at lower emissions is the onset of combustion instability, which is known to occur near the lean flammability limit. In a laboratory environment there are many sensors available which provide the combustion engineer with adequate information about flame stability, but those sensors are generally too expensive or unreliable for widespread application in the field. As a consequence, engines must be commissioned in the field with adequate stability margin such that normally expected component wear, fuel quality, and environmental conditions will not cause the turbine to experience unstable combustion. Woodward, in cooperation with NETL, is developing a novel combustion sensor which is integrated into the fuel nozzle such that low cost and long life are achieved. The sensor monitors flame ionization, which is indicative of air-fuel ratio, and most importantly flame stability.
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Zhang, Hui, Jianfeng Yao, Xiang Li, and Kai Zhao. "Maximising the Value of Multi-Sensor Streamer Data via MAZ Processing." In International Petroleum Technology Conference. IPTC, 2021. http://dx.doi.org/10.2523/iptc-21435-ms.
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Abstract The North West Shelf of Australia contains a late Paleozoic to Cenozoic sedimentary succession, which attains a thickness of over 10 km and is dominated by Triassic to Lower Cretaceous sediments. The deeper plays exist at multiple stratigraphic levels including oil-prone Jurassic sediments and faulted gas-prone Triassic sediments. The area has been proven difficult as far as seismic imaging is concerned, particularly over the Madeline trend. The presence of a hard, rugose water bottom, strong reflectors beneath the water bottom, and shallow Tertiary carbonates make the Dampier Sub-basin vulnerable to multiple contamination, amplitude distortion, lower signal-to-noise ratio (S/N) and unreliable AVO response. Poor seismic quality in the data has been a significant barrier to reducing exploration risk. In the 1990s, East Dampier (1992, blue polygon in Figure 1) and Keast (1997, yellow polygon in Figure 1) seismic data were acquired in East-West and North-South directions respectively, in an effort to better understand the impact from the shallow complex overburden. To address these challenges, the Demeter survey was acquired in 2003 (black polygon in Figure 1) with a denser acquisition grid. The overall seismic quality was improved, but the results still contained a significant level of residual multiples. Later, the Fortuna survey, the most comprehensive multi-sensor seismic survey on the North West Shelf of Australia to date, was acquired in 2014 with the aim to provide better subsurface imaging (pink polygon in Figure 1) from different acquisition perspectives. The data was processed with advanced processing technology, including shallow water demultiple, deghosting and high definition tilted orthorhombic velocity model building (Birdus et al., 2017). However, the final results were still suffering from a number of challenges, specifically: 1) strong residual multiple in near offsets, 2) low S/N ratio, particularly at reservoir level, and 3) inconsistency from near to far stack resulting in unreliable AVO. In this paper, the Dixon area (green polygon), considered as the most challenging area in the Dampier Sub-basin, was chosen as the testing area for our work. By integrating high-end imaging technology, for example dual-sensor deghosting, multi-survey surface related multiple elimination (MAZ-SRME), and multi-azimuth processing (MAZ stack), we will illustrate how we have overcome many of these imaging challenges.
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Qureshi, O. A., and P. R. Armstrong. "Near Optimal Model Predictive Control of Thermal Energy Storage." In ASME 2020 14th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/es2020-1705.
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Abstract Efficient plant operation can be achieved by properly loading and sequencing available chillers to charge a thermal energy storage (TES) reservoir. TES charging sequences are often determined by heuristic rules that typically aim to reduce utility costs under time of use rates. However, such rules of thumb are in most cases far from optimal even for this task. Rigorous optimization, on the other hand, is computationally expensive and can be unreliable as well if not carefully implemented. Model-predictive control (MPC) that is reliable, as well as effective, in TES application must be developed. The goal is to develop an algorithm that can reach ∼80% of achievable energy efficiency and peak shifting capacity with very high reliability. A novel algorithm is developed to reliably achieve near optimal control for charging cool storage in chiller plants. Algorithm provides a constant COP (or cost per ton-hour) for 24-hr dispatch plan at which plant operates during most favorable weather conditions. Preliminary evaluation of this novel algorithm has indicated up to 6% improvement in plant annual operating cost relative to the same plant operating without TES. TOU rate used in both cases charges 7.4cents/kWh during off peak hours and 9.8cents/kWh during peak hours (Peak hours are 10 am to 10 pm).
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Hasan, A. Rashid, Boyue Xu, and Dave Fyfe. "Analytical Models to Estimate Temperature Profiles During Drilling and Shut-In in Deepwater Environment." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78557.
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Drilling operations involve significant heat transfer between the drilling mud, downhole tubulars, and surrounding formation. Such heat transfer causes changes in drilling fluid temperature that alters drilling fluid density and viscosity, as well as changes near-wellbore formation temperature. Temperature changes in the near-wellbore formation need to be understood so that useful interpretation of often available temperature data from multiple discrete temperature sensors (MDTS) may be made. In deepwater assets, fluid circulation through cold water makes the problem more complex. Deepwater drilling operation could be viewed as consisting of four processes: (1) mud circulation in the riser affected by surrounding cold sea water; (2) mud circulation in the cased and cemented zone; (3) mud circulation through the target zone (open hole); (4) shut-in after drilling through the target zone. Forced convective heat transfer dominates in the first three processes while conductive heat transfer is dominant during the shut-in period. Estimating temperature in the wellbore during and after circulation is critical for mud rheology, tubular thermal stress, and cement design. Application of “rule-of-thumb” and/or complicated numerical simulation is often unreliable and/or impractical. This paper presents analytic models to estimate temperature profile during and after drilling fluid circulation in deepwater environment. Steady heat transfer is assumed in during fluid circulation, and transient modeling is performed for shut-in periods. Energy balance is set up over the differential control volume to develop the models. The end of circulation would provide the initial condition for the shut-in period. The models are used to estimate bottomhole temperature distribution during and after circulation. The analytical model is verified using data from a real deepwater well that had permanent downhole gauges (PDGs) installed at the bottomhole.
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Zhu, Xuehua, and Luis San Andre´s. "Experimental Response of a Rotor Supported on Rayleigh Step Gas Bearings." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68296.
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Reliable gas bearings will enable the rapid deployment of high speed oil-free micro-turbomachinery. This paper presents analysis and experiments of the dynamic performance of a small rotor supported on Rayleigh step gas bearings. Comprehensive tests demonstrate that Rayleigh step hybrid gas bearings exhibit adequate stiffness and damping capability in a narrow range of shaft speeds, up to ∼ 20 krpm. Rotor coast down responses were performed with two test bearing sets with nominal radial clearance of 25 μm and 38 μm. A near-frictionless carbon (NFC) coating was applied on the rotor to reduce friction at liftoff and touchdown. However, the rotor could not lift easily and severe rubbing occurred at shaft speeds below ∼ 4,000 rpm. The tests show that the supply pressure raises the rotor critical speed and decreases the system damping ratio, while only affecting slightly the rotor-bearing system onset speed of instability. Whirl frequencies are nearly fixed at the system natural frequency (∼ 120 Hz) with subsynchronous amplitude motions of very large magnitude that prevented rotor operation above ∼ 20 krpm. The geometry of the Rayleigh steps distributed on the rotor surface generates a time varying pressure field, resulting in a sizable 4X super synchronous component of bearing transmitted load. Predictions show the synchronous stiffness and damping coefficients decrease with shaft speed. Predicted threshold speeds of instability are much lower than measured values due to the analytical model limitations assuming a grooved stator. The predicted synchronous responses to imbalance correlate well with the measurements. The Rayleigh step gas bearings are the most unreliable rigid bearing configuration tested to date.
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Rostamy, Noorallah, Norense Okungbowa, and John D. Yurchevich. "Triggers for the Transient State of a Pipeline in Material Balance Systems Used in Real-Time Transient Hydraulic Modeling." In 2014 10th International Pipeline Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/ipc2014-33612.
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Computational Pipeline Monitoring (CPM) leak detection in liquid pipelines can be unreliable or have a high number of false alarms during transient hydraulic events. This paper presents techniques for avoiding these false alarms and for improving leak detectability during steady state operations. Application of this approach has improved both the sensitivity and reliability of CPM-based leak detection systems. When a pipeline is in steady-state operation, the leak detection thresholds can be reduced. When a transient is detected, the thresholds are increased to a higher value. Because of known errors in data measurement and the time at which the measurement was made, large uncertainties in the line-pack prediction can exist during these transient events. In this paper, CPM reliability is improved using dual thresholds; tight threshold for near steady state and relaxed threshold for transient operation. In the presented study, different transient triggers in a pipeline have been implemented to the dual threshold method in order to show the effect of transient thresholds on the reliability of the CPM models or the reduction in the number of false alarms. When the CPM model determines that a transient event is occurring, the imbalance threshold is increased to a pre-set higher value. The transient threshold will remain high until the transient event diminishes, then the thresholds will return to their original steady-state value after a pre-set wait period. This applies to each leak detection window and to each flow meter-to-flow meter section in the CPM model. Detailed information about the dual thresholds approach and the transient triggers is provided in the full paper. Results from the implementation of this method and the quantitative improvement of the CPM reliability and sensitivity will also be presented.
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Lacroix, Valéry, Pierre Dulieu, Kunio Hasegawa, and Vratislav Mares. "Treatment of the Interaction With the Free Surface of the Component for Combined Subsurface Flaws: Technical Basis for Revision of IWA-3300 and Table IWB/IWC-3510-1." In ASME 2020 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/pvp2020-21455.
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Abstract When flaws are detected in pressure retaining components, assessments have to be done in order to demonstrate the fitness-for-service (FFS) of the component for continued operation. This FFS demonstration is performed in accordance with FFS Codes providing flaw assessment procedures and acceptance standards. Before performing analyses, a flaw characterization has to be carried out in order to determine unequivocally the flaw geometry. This flaw characterization is done according to rules provided in the FFS Codes and hence appears as crucial for the rest of the flaw assessment. The first step of the flaw characterization addresses the interaction of the flaw and the free surface of the component: if a subsurface flaw is located near the free surface, this step consists of characterizing the flaw as surface or subsurface according to subsurface-to-surface flaw proximity rules. The recharacterization process from subsurface to surface flaw is addressed in all fitness-for-service (FFS) Codes. The second step of the flaw characterization addresses the interaction of the flaw with adjacent flaws: if a flaw is located near another flaw, this step consists of combining the flaws between them according to flaw proximity rules. However, in some FFS Codes and in the ASME B&PV Section XI Code particularly, there is a lack on how to treat the interaction of a combined flaw and the free surface of the component. The ASME B&PV Section XI Code flaw characterization is not clear on this topic which could lead to misinterpretations and unreliable flaw assessment results. Some typical examples of unrealistic flaw assessment results due to these misinterpretations of the ASME B&PV Code Section XI flaw characterization rules are depicted in this paper. After analyzing more in-depth the origin of the inconsistencies based on 3D Extended Finite Element Method (XFEM) calculations, the paper is used as Technical Basis for the improvement of the ASME B&PV Code Section XI in order to clarify the treatment of combined flaw in the flaw characterization (IWA-3300) and in the flaw acceptability assessment as well (IWB/IWC-3510-1).
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Younis, B. A., B. Weigand, and A. Laqua. "Prediction of Heat Transfer in Turbulent Channel Flow With Spanwise Rotation and Suction/Blowing Through Opposite Walls." In ASME Turbo Expo 2009: Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-59691.
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This paper is concerned with the prediction of heat transfer rates in fully-developed turbulent flows in straight channels with mass transfer by suction and blowing through opposite walls, and with rotation about the spanwise axis. The predictions are based on the solution of the Reynolds-averaged forms of the governing equations using a second-order accurate finite-volume formulation. The effects of turbulence on momentum transport were accounted for by using turbulence closures based on the solution of modeled differential transport equations for the Reynolds stresses. A number of alternative models were assessed. These included a high turbulence Reynolds-number model in which the computationally-efficient ‘wall-function’ approach was used to bridge the near-wall region. As the effects of stabilizing system rotation can cause flow relaminarization, the wall-function approach becomes unreliable and integration must be carried out through the viscous sub-layer, directly to the walls. The suitability of three alternative low Reynolds-number models was assessed in these flows. Experimental data from flows in stationary channels with Reynolds numbers spanning the range of laminar, transitional and turbulent regimes were also used in this assessment. Excellent predictions of the wall skin-friction coefficient across the entire range were obtained with a low Reynolds-number model in which the effects of a rigid wall on the fluctuating pressure field in its vicinity were accounted for by a method which incorporates the gradients of the turbulence length scale and the invariants of turbulence anisotropy. For the cases of heated flows, two very different models for the turbulent heat fluxes were examined: one involved the solution of a differential transport equation for each component of the heat-flux tensor and another in which the heat fluxes were obtained from an explicit algebraic model derived from tensor representation theory. It was found that the two models yielded results that were essentially similar and in close agreement with results from recent Direct Numerical Simulations.
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Ahsan, Mohammad J., Shaikha Al-Turkey, Nitin M. Rane, Fatemah A. Snasiri, Ahmed Moustafa, and Hakim Benyounes. "Advanced Gas While Drilling GWD Comparison with Pressure Volume Temperature PVT Analysis to Obtain Information About the Reservoir Fluid Composition, a Case Study from East Kuwait Jurassic Reservoir." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206296-ms.
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Abstract Objectives/Scope The acquisition of mud gas data for well control and gathering of geological information is a common practice in oil and gas drilling. However, these data are scarcely used for reservoir evaluation as they are presumably considered as unreliable and non-representative of the formation content. Recent development in gas extraction from drilling mud and analyzing equipment has greatly improved the data quality. Combined with proper analysis and interpretation, these new datasets give valuable information in real-time lithological changes, hydrocarbons content, water contacts and vertical changes in fluid over a pay interval. Methods, Procedures, Process Post completion, Mud logging data have been compared with PVT results and they have shown excellent correlation on the C1-C5 composition, confirming the consistency between gas readings and reservoir fluid composition. Having such information in real time has given the oil company the opportunity to optimize its operations regarding formation evaluation, e.g downhole sampling, wireline logging or testing programs. Formation fluid is usually obtained during well tests, either by running downhole tools into the well or by collecting the fluid at surface. Therefore, its composition remains unknown until the arrival of the PVT well test results. This case intends to use mud gas information collected while drilling to predict information about the reservoir fluid composition in near real time. To achieve this goal we compared mud gas data collected while drilling with reservoir fluid compositional results. Pressure volume temperature (PVT) analysis is the process of determining the fluid behaviors and properties of oil and gas samples from existing wells. Results, Observations, Conclusions The reason any oil and gas company decides to drill a well is to turn the project into an oil-producing asset. But the value of the oil extracted from a single well is not the same as the value of the oil produced from another. The makeup of the oil, which can be determined from the compositional analysis, is an important piece of the equation that determines how profitable the play will be. The compositional analysis will determine just how much of each type of petroleum product can be produced from a single barrel of oil from that wells. Novel/Additive information Formation samples were obtained from offset wells in the Marrat Formation. These datasets gave valuable indications on fluid properties and phase behavior in the reservoir and provided strong base for reservoir engineering analysis, simulation and surface facilities design. The comparison of the gas data to PVT results gives a good match for reservoir fluid finger print, early acquisition of this data will help for decision enhancement for field development.