Letteratura scientifica selezionata sul tema "High Angle TPC"
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Articoli di riviste sul tema "High Angle TPC"
1
White, J. W. "Flying Characteristics of the Transverse and Negative Pressure Contour (“TNP”) Slider Air Bearing." Journal of Tribology 119, no. 2 (1997): 241–48. http://dx.doi.org/10.1115/1.2833166.
Testo completoAbstract (sommario):
The TNP contour air bearing slider is composed of oversized transverse pressure contour (TPC) outer rails and a central negative pressure (NP) cavity. The NP cavity is separated from the TPC rails by an ambient pressure reservoir which serves two functions. First, it prevents direct hydrodynamic interaction between the various component air bearing surfaces and thus, eliminates pressure distortion and dilution, common causes of problems related to flying height and roll angle control. Second, the ambient reservoir allows the TPC rails and NP cavity to be configured and dimensioned independently so that they will track each other with a nearly constant force difference, resulting in a flying height that has significantly reduced sensitivity to altitude change. The multi-function TPC sections of the outside rails are able to overcome the effects of a changing radius and wide skew angle variation over the disk radius as well as a changing vacuum load and asymmetry of the NP cavity pressure, in order to provide a truly constant low flying height over the entire data surface. The combination of a high air bearing stiffness and a gradually developing cavity vacuum as disk velocity increases produces a rapid slider take-off from the disk surface. Dynamic stability of the TNP slider air bearing is enhanced by the unusual combination of a high air bearing stiffness and high air film damping in each of the three slider excursion modes. Finally, the TNP slider experiences a reduced sensitivity of flying height to manufacturing and operational tolerances as compared to non-NP type sliders. The entire TNP slider air bearing is created by a two-etch process. A shallow etch creates the TPC sections and leading edge step. A deeper etch forms the NP cavity, ambient pressure reservoir, and outermost edge of each side rail.
2
Kodagoda, Gethmini, Hung T. Hong, Tim J. O’Hare, Yasmina Sultanbawa, Bruce Topp, and Michael E. Netzel. "Effect of Storage on the Nutritional Quality of Queen Garnet Plum." Foods 10, no. 2 (2021): 352. http://dx.doi.org/10.3390/foods10020352.
Testo completoAbstract (sommario):
Due to high perishability, plums are harvested at an early stage of maturity to extend postharvest storage life. Storage time and temperature can significantly affect the phytochemical and sugar composition of plums, altering their palatability and nutritional quality. In this study, variations in physiochemical properties (total soluble solids (TSS), titratable acidity (TA), color (chroma and hue angle)), phytochemical composition (total phenolic content (TPC), total anthocyanin content (TAC), and carotenoids), and sugars in three different tissues of the Queen Garnet plum (QGP) during storage at two common domestic storage temperatures (4 and 23 °C) were evaluated. There was an increase (p > 0.05) in TSS and a reduction (p < 0.05) in TA of the outer flesh at 23 °C. Chroma values of all the tissues reduced (p < 0.05) at 23 °C. At 4 °C, chroma values fluctuated between storage days. The TAC of the peel was the highest (p < 0.05) among the different tissues and continued to increase up to 10 days of storage at 23 °C (3-fold increase). At 4 °C, the highest (p < 0.05) TAC (peel) was observed after 14 days of storage (1.2-fold increase). TPC showed similar results. The highest (p < 0.05) TPC was recorded in the peel after 10 days of storage at 23 °C (2.3-fold increase) and after 14 days of storage at 4 °C (1.3-fold increase), respectively. Total carotenoids in the flesh samples at both storage temperatures were reduced (p < 0.05) after 14 days. Total sugars also decreased during storage. The results of the present study clearly showed that common domestic storage conditions can improve the nutritional quality of plums by increasing the content of bioactive anthocyanins and other phenolic compounds. However, the increase in phytochemicals needs to be counterbalanced with the decrease in total sugars and TA potentially affecting the sensory attributes of the plums.
3
Jones, S. B., T. S. Nonnenmacher, E. Atkin, et al. "Off-Axis Characterisation of the CERN T10 Beam for low Momentum Proton Measurements with a High Pressure Gas Time Projection Chamber." Instruments 4, no. 3 (2020): 21. http://dx.doi.org/10.3390/instruments4030021.
Testo completoAbstract (sommario):
We present studies of proton fluxes in the T10 beamline at CERN. A prototype high pressure gas time projection chamber (TPC) was exposed to the beam of protons and other particles, using the 0.8 GeV/c momentum setting in T10, in order to make cross section measurements of low energy protons in argon. To explore the energy region comparable to hadrons produced by GeV-scale neutrino interactions at oscillation experiments, i.e., near 0.1 GeV of kinetic energy, methods of moderating the T10 beam were employed: the dual technique of moderating the beam with acrylic blocks and measuring scattered protons off the beam axis was used to decrease the kinetic energy of incident protons, as well as change the proton/minimum ionising particle (MIP) composition of the incident flux. Measurements of the beam properties were made using time of flight systems upstream and downstream of the TPC. The kinetic energy of protons reaching the TPC was successfully changed from ∼0.3 GeV without moderator blocks to less than 0.1 GeV with four moderator blocks (40 cm path length). The flux of both protons and MIPs off the beam axis was increased. The ratio of protons to MIPs vary as a function of the off-axis angle allowing for possible optimisation of the detector to select the type of required particles. Simulation informed by the time of flight measurements show that with four moderator blocks placed in the beamline, (5.6 ± 0.1) protons with energies below 0.1 GeV per spill traversed the active TPC region. Measurements of the beam composition and energy are presented.
4
Liu, Mengnan, Yu Han, Xiaoqi Xi, et al. "Drift Artifacts Correction for Laboratory Cone-Beam Nanoscale X-ray Computed Tomography by Fitting the Partial Trajectory of Projection Centroid." Photonics 9, no. 6 (2022): 405. http://dx.doi.org/10.3390/photonics9060405.
Testo completoAbstract (sommario):
A self-correction method for the drift artifacts of laboratory cone-beam nanoscale X-ray computed tomography (nano-CT) based on the trajectory of projection centroid (TPC) is proposed. This method does not require additional correction phantoms, simplifying the correction process. The whole TPC is estimated by the partial TPC in the optimal projection set. The projection drift is calculated by the measured TPC and the estimated TPC. The interval search method is used so that the proposed method can adapt to the case of a truncated projection due to drift. The fixed-angle scanning experiment of the Siemens star and the partial derivative analysis of the projection position show the necessity of correcting drift artifacts. Further, the Shepp–Logan phantoms with different drift levels are simulated. The results show that the proposed method can effectively estimate the horizontal and vertical drifts within the projection drift range of ±2 mm (27 pixels) with high accuracy. Experiments were conducted on tomato seed and bamboo stick to validate the feasibility of the proposed method for samples with different textures. The correction effect on different reconstructed slices indicates that the proposed method provides performance superior to the reference scanning method (RSM) and global fitting. In addition, the proposed method requires no extra scanning, which improves the acquisition efficiency, as well as radiation utilization.
5
Soethe, Cristina, Cristiano André Steffens, Leonora Mansur Mattos, Nathalie Alcântara Ferreira, and Daiane Michele Mayer. "Postharvest quality and functional compounds in "dedo-de-moça" 'BRS Mari' pepper fruit at different stages of maturity." Ciência Rural 46, no. 8 (2016): 1322–28. http://dx.doi.org/10.1590/0103-8478cr20141795.
Testo completoAbstract (sommario):
ABSTRACT: The purpose of this study was to evaluate the physicochemical characteristics and functional properties of "dedo-de-moça" 'BRS Mari' pepper fruits at different maturity stages, and determine the ideal harvest stage for fresh consumption. The pepper plants were grown in the experimental field of Embrapa Hortaliças (Brasília, DF, Brazil) in 2012, and their fruits were evaluated at 20, 30, 40, 50, 60, 70, and 80 days after anthesis (DAA) to determine the soluble solid content (SS), titratable acidity (TA), SS/TA ratio, color (hue angle and lightness), a, b, and total chlorophyll, total phenolic compounds (TPC), total antioxidant activity (TAA), and capsanthin. It was observed that SS content increased until 70 DAA, and TA increased until 50 DAA, with decrease at 80 DAA. The a and total chlorophyll decreased until 60 DAA. Values for chlorophyll b were high until 30 DAA, and then decreased. The values for hue angle and lightness decreased until 60 DAA, indicating a change from green to red in fruits external color, with small changes in color from 60 to 80 DAA. The TPC content increased until 60 DAA, and then small increases occurred until 80 DAA. The AA increased as the fruit ripened, and the capsanthin content increased until 70 DAA. These results indicated that the ideal stage for harvest of the "dedo-de-moça" 'BRS Mari' pepper fruits is at 70 days after anthesis, when they also have a full development of red color in the fruit epidermis.
6
SHAO, MING, and LIANG LI. "A STUDY ON THE INTRINSIC TIME RESOLUTION OF THE MRPC USED IN THE STAR-TOF." International Journal of Modern Physics E 16, no. 07n08 (2007): 2476–83. http://dx.doi.org/10.1142/s0218301307008124.
Testo completoAbstract (sommario):
Time-Of-Flight (TOF) based on Multi-gap Resistive Plate Chamber (MRPC) detectors have been successfully operating at the STAR experiment since 2003.2,3 The MRPC time resolution is however found to be significantly worse2 (80-90 ps) than that previously obtained in beam test (60 ps).4 In order to fully understand MRPC working principles and operating requirements, an extensive calibration study is performed using data collected by STAR in 200 GeV Au + Au collisions in 2004. The relation between MRPC timing, signal amplitude, incident angle and momentum are discussed. Contributions from tracking properties of STAR-TPC are also studied by simulation. The intrinsic time resolution of the MRPCs used in STAR-TOF, after taking all factors into consideration, is found to be in good agreement with beam test results.
7
Muzolf-Panek, Małgorzata, and Agnieszka Waśkiewicz. "Relationship between Phenolic Compounds, Antioxidant Activity and Color Parameters of Red Table Grape Skins Using Linear Ordering Analysis." Applied Sciences 12, no. 12 (2022): 6146. http://dx.doi.org/10.3390/app12126146.
Testo completoAbstract (sommario):
Color, being one of the most important sensory characteristics, could be associated to the phenolic compound content and/or the antioxidant activity of fruits and vegetables. In this study, linear ordering was used to build quality rankings of red table grapes based on color parameters or phenolic compounds. First, the principle component analysis (PCA) was used to show the association between color of red grape skins (evaluated in CIE L*a*b* and L*C*h systems) and their individual phenolic compounds (investigated by the HPLC), total polyphenol content (TPC), total anthocyanins (ACNs), as well as the antioxidant activity (DPPH) of five table grape varieties. It could be observed that the lightness (L*) and hue angle (h) are the color coordinates strongly related to some phenolic compounds and ACN, whereas a* was related to DPPH and TPC. Five distinct clusters could be observed from PCA analysis with dark-colored grape varieties showing high levels of ACN (3.48–5.83 mg/g), low lightness (47.8–53.0), and high h values (353.7–359.8°). L*, a*, and h color coordinates were used to build table grape ranking. The second ranking was built based on phenolic compound content. Results of the two rankings were correlated. High Tau Kendall correlation coefficient (0.51, p = 0.000) indicated that linear ordering analysis, based on the simple color measurements, could be a useful tool for rapid screening of the quality of grapes. This could be valuable information for producers and consumers of the fruit making decision on the market.
8
Kumar, Abhinay, Rajan Choudhary, and Ankush Kumar. "Aging characteristics of asphalt binders modified with waste tire and plastic pyrolytic chars." PLOS ONE 16, no. 8 (2021): e0256030. http://dx.doi.org/10.1371/journal.pone.0256030.
Testo completoAbstract (sommario):
Globally, the growing volume of waste tires and plastics has posed significant concerns about their sustainable and economical disposal. Pyrolysis provides a way for effective treatment and management of these wastes, enabling recovery of energy and produces solid pyrolytic char as a by-product. The use of pyrolytic chars in asphalt binder modification has recently gained significant interest among researchers. As asphalt binder aging influences the cracking, rutting, and moisture damage performance of asphalt binder and the mixtures, evaluation of aging characteristics of char modified asphalt binders is quite important. The main objective of this study is the investigation of the aging characteristics of asphalt binders modified with waste tire pyrolytic char (TPC) and waste plastic pyrolytic char (PPC) through rheological and spectroscopic evaluations. To imitate short-term and long-term aging conditions, the asphalt binders were first treated in a rolling thin film oven (RTFO) and then in a pressure aging vessel (PAV). The aging characteristics were determined using four rheological aging indices based on complex modulus (G*), phase angle (δ), zero shear viscosity (ZSV), and non-recoverable creep compliance (Jnr) from multiple stress creep and recovery (MSCR) test. The fatigue cracking potential was then measured through binder yield energy test (BYET). These parameters were measured through a dynamic shear rheometer. Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy analyses were then used to investigate changes in chemical composition due to aging in the char modified binders. Both TPC and PPC improved the high-temperature deformation resistance properties of asphalt binder. The TPC-modified binder showed better aging resistance than the control and PPC-modified binders, based on the different rheological and spectroscopic indices. The pyrolytic char modified binders also demonstrated good fatigue performance.
9
Zhao, Xianli, Wei Liu, Cong Li, et al. "Solid Particle Erosion Behavior of La2Ce2O7/YSZ Double-Ceramic-Layer and Traditional YSZ Thermal Barrier Coatings at High Temperature." Coatings 12, no. 11 (2022): 1638. http://dx.doi.org/10.3390/coatings12111638.
Testo completoAbstract (sommario):
Thermal barrier coatings (TBC) used for turbine blades are indispensable for the most advanced aero-engines due to their excellent thermal insulation performance. Solid particle erosion (SPE) at high temperatures is one of the most critical factors in TBC failure. The high-temperature SPE failure behavior of TBC on circular sheets and turbine blades was investigated in this paper at erosion angles 60° and 90°. The high-temperature thermal shock behavior of TBC was also studied as the control group. The SPE failure mechanism of TBC is attributed to the spallation and thickness decrease of TBC. The formation of thermally grown oxide is the main reason for the TBC spallation, while the thickness decrease of TBC is due to the impaction of solid particles by near-surface cracking. The erosion angle is critical to the failure behavior of TBC, and TBC is more susceptible to SPE at an erosion angle of 60° than that at 90° because of the additional shear stress. Furthermore, a La2Ce2O7/YSZ double-ceramic-layer TBC was designed and deposited on turbine blades. The experimental results indicate that this type of double-layer TBC has more excellent performance under SPE than traditional YSZ TBC.
10
Fang, T.-G., R. E. Coverdill, C.-F. F. Lee, and R. A. White. "Low-sooting combustion in a small-bore high-speed direct-injection diesel engine using narrow-angle injectors." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 222, no. 10 (2008): 1927–37. http://dx.doi.org/10.1243/09544070jauto751.
Testo completoAbstract (sommario):
An optically accessible high-speed direct-injection diesel engine was used to study the effects of injection angles on low-sooting combustion. A digital high-speed camera was employed to capture the entire cycle combustion and spray evolution processes under seven operating conditions including post-top-dead centre (TDC) injection and pre-TDC injection strategies. The nitrogen oxide (NO x) emissions were also measured in the exhaust pipe. In-cylinder pressure data and heat release rate calculations were conducted. All the cases show premixed combustion features. For post-TDC injection cases, a large amount of fuel deposition is seen for a narrower-injection-angle tip, i.e. the 70° tip, and ignition is observed near the injector tip in the centre of the bowl, while for a wider-injection-angle tip, namely a 110° tip, ignition occurs near the spray tip in the vicinity of the bowl wall. The combustion flame is near the bowl wall and at the central region of the bowl for the 70° tip. However, the flame is more distributed and centralized for the 110° tip. Longer spray penetration is found for the pre-TDC injection timing cases. Liquid fuel impinges on the bowl wall or on the piston top and a fuel film is formed. Ignition for all the pre-TDC injection cases occur in a distributed way in the piston bowl. Two different combustion modes are observed for the pre-TDC injection cases including a homogeneous bulky combustion flame at earlier crank angles and a heterogeneous film combustion mode with luminous sooting flame at later crank angles. In terms of soot emissions, NO x emissions, and fuel efficiency, results show that the late post-TDC injection strategy gives the best performance.
Tesi sul tema "High Angle TPC"
1
Joshi, Shivam. "Characterization of resistive Micromegas for High Angle-Time Projection Chambers readout and preparation of neutrino physics analysis with upgraded near detector of T2K experiment." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASP123.
Testo completoAbstract (sommario):
Le travail de thèse se situe dans le domaine de la physique des neutrinos dans le cadre de l'expérience T2K. La thèse est divisée en deux sujets : la caractérisation des détecteurs et la préparation de l'analyse physique. Dans le contexte de la mise à niveau du détecteur proche de T2K - ND280, un modèle a été développé et utilisé pour caractériser la dispersion de charge dans le détecteur Micromegas résistif novateur (ERAM). De plus, le gain et la résolution énergétique de chaque ERAM ont été obtenus, pad par pad, pour une caractérisation complète. Les résultats ont directement conduit à la sélection d'ERAM spécifiques pour une installation à des positions spécifiques sur les plans d'anode des chambres à projection temporelle à grand angle. Au total, 37 ERAM ont été caractérisés avec succès en utilisant des données aux rayons X provenant d'un banc d'essai au CERN. Ces informations ont également été utilisées pour la reconstruction. L'amélioration des statistiques et de l'efficacité de détection des événements quasi-élastiques en courant chargé dans la région de haut Q² (transfert de moment à quatre dimensions) après la mise à niveau du ND280 a été étudiée. La question de savoir dans quelle mesure les incertitudes de haut Q² seront effectivement contraintes après la mise à niveau du ND280 par les 4 paramètres de haut Q² dans le modèle de section efficace neutrino-noyau a été abordée en utilisant les outils de re-pondération de T2K et le programme d'ajustement - GUNDAM. Une source importante des incertitudes de haut Q² est le modèle de facteur de forme axial-vecteur (dipolaire) actuellement utilisé dans le modèle de section efficace. Certains modèles alternatifs de facteur de forme qui peuvent mieux contraindre ces incertitudes ont également été étudiés. L'effet des incertitudes dans l'estimation de l'énergie de liaison des nucléons sur différentes variables (cinématique des muons, énergie des neutrinos, etc.) a été étudié. Des splines par bins ont été produites pour les 4 paramètres de l'énergie de liaison dans le modèle de section efficace dans le contexte de l'analyse des oscillations utilisant les données collectées en 2024<br>The PhD work is in the field of Neutrino Physics as a part of the T2K experiment. The thesis is divided into two subjects- detector characterization and preparation of physics analysis. In the context of the upgrade of T2K near detector- ND280, a model was developed and utilized to characterize the charge spreading in novel resistive Micromegas (ERAM) detector. In addition, pad-by-pad gain and energy resolution was obtained for each ERAM for a complete characterization. The results directly led to the selection of specific ERAMs for installation at specific positions in the High Angle-Time Projection Chamber anode planes for charge readout. In total, 37 ERAMs were successfully characterized using X-ray data from a test bench at CERN. This information was also used as inputs for reconstruction. Improvement in statistics and detection efficiency of charged-current quasi-elastic events in high Q² (4-momentum transfer) region after the ND280 upgrade was studied. The question of- how effectively the high Q² uncertainties will be constrained after the ND280 upgrade by the 4 high Q² parameters in the neutrino-nucleus cross-section model was addressed using T2K re-weighting tools and the ND280 fitter- GUNDAM. An important source of the high Q² uncertainties is the axial-vector form factor model (dipole) used currently in the cross-section model. Some alternative form factor models that can better constrain these uncertainties were also studied. The effect of uncertainties in nucleon removal energy estimation on different variables (muon kinematics, neutrino energy, etc.) was studied. Binned splines were produced for the 4 removal energy parameters in the cross-section model in the context of Oscillation Analysis using data collected in 2024
Capitoli di libri sul tema "High Angle TPC"
1
Aebi, P. "Fermi Surface Mapping by Angle-Scanned Photoemission." In High-Tc Superconductors and Related Materials. Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-010-0758-0_2.
Testo completoAtti di convegni sul tema "High Angle TPC"
1
Feltre, Matteo. "Characterization of the ERAM Detectors for the High Angle TPC of the T2K near Detector Upgrade." In NuFACT 2022. MDPI, 2023. http://dx.doi.org/10.3390/psf2023008047.
Testo completo
2
Murphy, Robert G., Andrew C. Nix, Seth A. Lawson, Douglas Straub, and Stephen K. Beer. "Investigation of Factors That Contribute to Deposition Formation on Turbine Components in a High-Pressure Combustion Facility." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-94657.
Testo completoAbstract (sommario):
Researchers at West Virginia University worked with the U.S. Department of Energy, National Energy Technology Laboratory (NETL) to study particulate deposition in a high-pressure and high-temperature environment. To simulate deposition of particulate from combustion of coal synthesis gas on the pressure side of an Integrated Gasification Combined Cycle (IGCC) turbine first stage vane, angled film-cooled thermal barrier coated (TBC) test articles scaled to turbine flow conditions using Reynolds similarity were subjected to accelerated deposition at a pressure of approximately 4 bar and a gas temperature ranging from 1373–1560K. The effects on deposition rates of five different factors were examined; free stream temperature, impaction angle, blowing ratio, particulate loading, and TBC vs. non-TBC coated surface. As the freestream temperature increased the results showed that the deposition also increased. The amount of deposition increased as the impaction angle increased from 10° to 20°. The effect of blowing ratio (M, mass flux ratio) was examined at M = 0.0, 0.25 and 1.0. As the blowing ratio increased the amount of deposition decreased. The particulate loading was varied from 100 ppmw to 200 ppmw. The amount of deposition increased with the higher particulate loading case; however, coverage on the test article face did not increase significantly. Finally, a comparison test was performed between a TBC coated test article and a bare metal test article. This test showed that more deposition formed on the TBC coated article than the bare metal article. During testing, the deposition that formed on the TBC coated test articles demonstrated a resistance to adhering to the surface once the mainstream temperature was reduced during facility shut down. The results of this work will aid gas turbine manufacturers to better understand and develop mitigations for the five factors studied that cause deposit formations in IGCC engines. This work will also give insight to researchers studying deposition on the methods developed and issues encountered in simulating particulate matter into a high-pressure combustion facility.
3
Li, Changgang, Yilu Liu, and Matthew R. Gardner. "Transient stability analysis with phase plane of high-order derivatives of angle dynamics." In 2014 IEEE/PES Transmission & Distribution Conference & Exposition (T&D). IEEE, 2014. http://dx.doi.org/10.1109/tdc.2014.6863350.
Testo completo
4
Wang, D., D. H. Wilson, and S. Clark. "Defining constraint thresholds by angles in a stability constrained corridor with high wind." In 2014 IEEE/PES Transmission & Distribution Conference & Exposition (T&D). IEEE, 2014. http://dx.doi.org/10.1109/tdc.2014.6863167.
Testo completo
5
Murphy, Robert G., Andrew C. Nix, Seth A. Lawson, Douglas Straub, and Stephen K. Beer. "Preliminary Experimental Investigation of the Effects of Particulate Deposition on IGCC Turbine Film-Cooling in a High-Pressure Combustion Facility." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-68806.
Testo completoAbstract (sommario):
Researchers at West Virginia University are working with the U.S. Department of Energy, National Energy Technology Laboratory (NETL) to study the effects of particulate deposition on turbine film cooling in a high pressure and high temperature environment. To simulate deposition on the pressure side of an Integrated Gasification Combined Cycle (IGCC) turbine first stage vane, angled film-cooled test articles with thermal barrier coatings (TBC) are subjected to accelerated deposition at a pressure of approximately 4 atm and a gas temperature of 1100°C. Two different test article geometries were designed, with angles of 10° and 20° to the mainstream flow. Both geometries have straight-cooling holes oriented at a 30° angle to the hot-side surface. A high pressure seeding system was used to generate a particulate concentration of approximately 33.3 ppmw. Particle concentrations of 0.02 ppmw exist in the IGCC hot gas path. An accelerated simulation method was developed to simulate deposition that would occur in 10000 hr of engine operation. Preliminary tests were performed at 4 atm and 1100 °C to validate the deposition process. The results showed more deposition on the 20° test article than the 10° test articles; however no substantial deposition developed on either test article. A lumped mass analysis showed that the fly ash particles dropped below the theoretical sticking temperature as they approached the test article. Deposition was analyzed non-destructively through visual observation and scanning with a scanning laser microscope. Based on the initial test run results, a detailed plan was created to increase the operating temperature of the rig and allow two 3-hour tests to be performed on each of the test articles. Non-destructive testing will be used before, in between and after the runs to examine the evolution of the deposition growth. Following the final run, destructive testing will be used to examine the chemical composition of the deposits and their potential interaction with the TBC. Preliminary work will lead to a future study the would enhance the understanding of particle deposition evolution and examine the effects of deposition on film cooling by performing the tests in a high-pressure and high-temperature environment that is similar to the high-pressure combustion exhaust gas environment of the first stage region in IGCC turbines.
6
Jo, Chul-hee, Kang-hee Lee, and Yu-ho Rho. "Active Vanning Device and Maintenance System for Horizontal Axis Tidal Current Turbine." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20305.
Testo completoAbstract (sommario):
The application of TCP (Tidal Current Power) on the west and south coastal regions in Korea seems to be very suitable. There are many potential sites with high current speed up to 6.5m/s. Not like other renewable energy sources, TCP is very reliable and predictable and continuous energy as the tidal current pattern can be predicted throughout the year. One of the essential components in TCP device is the rotor that can convert the inflow current into the rotational energy. The design and optimization of rotor are very important to maximize the power production. The performance of rotor can be determined by various parameters including number of blades, shape, sectional size, hub, diameters and etc. The attack angle also affect significantly on the efficiency of the system. It is very important to maintain the 90 degree of attack angle to the rotor. In Korea, there are distinguishable flow direction changes from high and low tides. To cope with this environmental, a new device so called “Active vanning HAT (horizontal axis turbine) system” is introduced to accommodate the change of incoming flow direction. The experiment results and the performances of the device are introduced in the paper.
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Chen, Gong. "Characterization of Variations in Cylinder Peak Pressure and its Position of High-Power Turbo-Charged Compression-Ignition Engines." In ASME 2016 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icef2016-9425.
Testo completoAbstract (sommario):
Cylinder peak pressure (pmax) over operating cycle of a high-power turbo-charged compression-ignition engine indicates its in-cylinder combustion behavior and also the level of mechanical load acting on its power assembly components. It is significantly important to understand how pmax with cylinder pressure (p) varies due to possible changes in engine design and operation input condition parameters. The input parameters considered in this paper include piston crank-angle position (θ), compression ratio (CR), amount of cycle burning heat (Q), injection/combustion duration (Δθ), and fuel injection/combustion-start timing (θs). Effects of the input parameters to pmax and θpmax which is the crank-angle position of pmax in engines of this type are analyzed, predicted and characterized. Results with the approaches to achieving those are presented. It is indicated from the results that the crank-angle position of combustion duration (Δθ) has a significant effect on θpmax for a given engine power density. As the position of Δθ varies, θpmax varies accordingly and can be determined. It is also indicated that as θs is sufficiently retarded from a position before the top dead center (TDC) to a point close to TDC, either before or after, in a large-bore high-power turbocharged engine, the trend of pmax variation would be reversed. This establishes the minimum value of pmax over the range of engine combustion-start timing variation. The results and indications are beneficial and usefully needed in adjusting the design and operation input condition parameters for achieving optimized balances between power-output capacity, fuel efficiency, exhaust emissions and mechanical/thermal loading of engines in this type.
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Singh, Chandra Pratap, Arif Taibani, and Shankar Krishnan. "A New Design Methodology of Thermal Barrier Coating (TBC) for Internal Combustion Engines." In ASME 2020 Heat Transfer Summer Conference collocated with the ASME 2020 Fluids Engineering Division Summer Meeting and the ASME 2020 18th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/ht2020-9070.
Testo completoAbstract (sommario):
Abstract Currently available Internal combustion (IC) engines contribute 25% of the total world energy consumption. IC engines convert only 40% of the fuel energy into the indicated power[1]. Roughly, 30 percent of heat energy is lost from the combustion chamber to the environment. Interest in the design and development of thermal barrier coating (TBC) is increasing due to an increase in fuel costs and due to the decrease in high quality fuel production[2], [3]. The coating materials with low thermal conductivity and high heat capacity led to problems of high surface temperature, which degrade the volumetric efficiency and an increase in the NOx emission. On the other hand, thin TBC of low thermal conductivity and low heat capacity showed high thermal efficiency. Thin coatings could able to prevent intake air heating with effective resistance during the combustion[4]. However, fundamental relationships between thermal efficiency and thermophysical properties, structure, and durability of TBC still need to be investigated. Few studies suggested that the heat interaction study based on the crank angle position could be the best method to estimate the thermodynamics efficiency than the conventionally calculated heat rejection by the adiabatic engine[5], [6]. This work shows a design methodology to develop a thermal barrier coating (TBC), which can reduce heat loss by maintaining the minimum temperature difference between the surface and the in-cylinder gas temperature. The temperature fluctuation of TBC improves the thermal efficiency of internal combustion (IC) engines by reducing the heat loss to the coolant. This work also investigates the thermophysical behaviour of nearby available material and the applicability as a TBC.
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Kodavasal, Janardhan, Kevin Harms, Priyesh Srivastava, et al. "Development of a Stiffness-Based Chemistry Load Balancing Scheme, and Optimization of I/O and Communication, to Enable Massively Parallel High-Fidelity Internal Combustion Engine Simulations." In ASME 2015 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/icef2015-1035.
Testo completoAbstract (sommario):
A closed-cycle gasoline compression ignition engine simulation near top dead center (TDC) was used to profile the performance of a parallel commercial engine computational fluid dynamics code, as it was scaled on up to 4096 cores of an IBM Blue Gene/Q supercomputer. The test case has 9 million cells near TDC, with a fixed mesh size of 0.15 mm, and was run on configurations ranging from 128 to 4096 cores. Profiling was done for a small duration of 0.11 crank angle degrees near TDC during ignition. Optimization of input/output performance resulted in a significant speedup in reading restart files, and in an over 100-times speedup in writing restart files and files for post-processing. Improvements to communication resulted in a 1400-times speedup in the mesh load balancing operation during initialization, on 4096 cores. An improved, “stiffness-based” algorithm for load balancing chemical kinetics calculations was developed, which results in an over 3-times faster run-time near ignition on 4096 cores relative to the original load balancing scheme. With this improvement to load balancing, the code achieves over 78% scaling efficiency on 2048 cores, and over 65% scaling efficiency on 4096 cores, relative to 256 cores.
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Joshi, Girija K., Mihira N. Acharya, Marie Van Steene, et al. "Direct TOC Quantification in unconventional Kerogen-rich Shale Resource Play from Elemental Spectroscopy Measurements: A Case Study from North Kuwait." In SPE Middle East Unconventional Resources Conference and Exhibition. SPE, 2015. http://dx.doi.org/10.2118/spe-172975-ms.
Testo completoAbstract (sommario):
Abstract The deep organic-rich calcareous Kerogen of North Kuwait, a continuous 50ft thinly alternating carbonate – organic-rich argillaceous sequence, is not only a source rock but has gained importance as potential reservoirs themselves of typical unconventional category. Resource play or Kerogen characterization relies on quantifying total organic carbon (TOC) and estimating accurate mineralogy. This paper describes the first attempt to directly measure total organic carbon of the Limestone-Kerogen sequence. For the present study, empirical estimations of TOC have been carried out based on conventional log measurements and nuclear magnetic resonance (NMR). The introduction of a new neutron-induced capture and inelastic gamma ray spectroscopy tool using a very high-resolution scintillator and a new type of pulsed neutron generator for the deep unconventional kerogen resources have provided a unique opportunity to measure a stand-alone quantitative TOC value using a combination of capture and inelastic gamma ray spectra. In this process, Inorganic Carbon Content (ICC) is estimated by using elemental concentrations measured by this logging tool in addition to measuring Total Carbon, and this value is subtracted from the measured total carbon to give TOC. The advanced elemental spectroscopy tool measurements were first used to determine accurately the complex mineralogy of the layered carbonate and organic-rich shale sequence. Extensive laboratory measurements of core / cuttings data were used to calibrate the petrophysical evaluation and capture the heterogeneity seen on borehole image logs. The final analysis shows considerable improvements compared to conventional empirical estimation. Once the mineralogy is properly determined, the log-derived TOC matches very well with core measured TOC. This technique has provided a new direct and accurate log-derived TOC for Kerogen characterization. The application has a potential to be used for CAPEX optimization of the coring in future wells. This technique can also be applied in HPHT and High-angle horizontal wells, which can overcome challenging coring difficulties in horizontal wells.
Rapporti di organizzazioni sul tema "High Angle TPC"
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Revina, Shintia, Rezanti Putri Pramana, Rizki Fillaili, and Daniel Suryadarma. Systemic Constraints Facing Teacher Professional Development in a Middle-Income Country: Indonesia’s Experience Over Four Decades. Research on Improving Systems of Education (RISE), 2020. http://dx.doi.org/10.35489/bsg-rise-wp_2020/054.
Testo completoAbstract (sommario):
Despite government efforts to reform teacher professional development (TPD) in the past four decades, Indonesian teacher quality remains low. Why have the improvement efforts failed? In the present study we investigate what caused these reforms to fail from two angles. First, we examine the efficacy of the latest teacher professional development (TPD) initiative in Indonesia, Pengembangan Keprofesian Berkelanjutan or PKB (Continuing Professional Development), and identify the factors affecting its efficacy. We found that some essential features of effective TPD are missing in PKB. The PKB programme has not targeted teachers based on years of experience, has not followed up teachers with post-training activities, has not incorporated teaching practice through lesson enactment, and has not built upon teacher existing practice. Second, our analysis demonstrates that PKB's weaknesses have existed in Indonesia's previous TPD initiatives as far back as four decades ago. This indicates that the long-term problem of TPD’s ineffectiveness is driven by different elements of the education system beyond the TPD’s technical and operational aspects. Our system-level analysis points out that merely improving the technical aspects of TPD would be insufficient given the Indonesian education system’s lack of coherence surrounding teacher quality. The problems surrounding the provision of effective TPD is more complex than simply a matter of replacing the “old” with the “new” initiative. The change requires a reorientation of the education system to produce high-quality teachers.
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Revina, Shintia, Rezanti Putri Pramana, Rizki Fillaili, and Daniel Suryadarma. Systemic Constraints Facing Teacher Professional Developmentin a Middle-Income Country: Indonesia’s Experience Over Four Decades. Research on Improving Systems of Education (RISE), 2020. http://dx.doi.org/10.35489/bsgrisewp_2020/054.
Testo completoAbstract (sommario):
Despite government efforts to reform teacher professional development (TPD) in the past four decades, Indonesian teacher quality remains low. Why have the improvement efforts failed? In the present study we investigate what caused these reforms to fail from two angles. First, we examine the efficacy of the latest teacher professional development (TPD) initiative in Indonesia, Pengembangan Keprofesian Berkelanjutan or PKB (Continuing Professional Development), and identify the factors affecting its efficacy. We found that some essential features of effective TPD are missing in PKB. The PKB programme has not targeted teachers based on years of experience, has not followed up teachers with post-training activities, has not incorporated teaching practice through lesson enactment, and has not built upon teacher existing practice. Second, our analysis demonstrates that PKB's weaknesses have existed in Indonesia's previous TPD initiatives as far back as four decades ago. This indicates that the long-term problem of TPD’s ineffectiveness is driven by different elements of the education system beyond the TPD’s technical and operational aspects. Our system-level analysis points out that merely improving the technical aspects of TPD would be insufficient given the Indonesian education system’s lack of coherence surrounding teacher quality. The problems surrounding the provision of effective TPD is more complex than simply a matter of replacing the “old” with the “new” initiative. The change requires a reorientation of the education system to produce high-quality teachers.