To see the other types of publications on this topic, follow the link: A Single Injection.
Dissertations / Theses on the topic 'A Single Injection'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'A Single Injection.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Bhamidipati, Harini. "SINGLE TROJAN INJECTION MODEL GENERATION AND DETECTION." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1253543191.
Full text
2
Davies, Alan Edward. "Single boundary measurements in flow analysis." Thesis, Loughborough University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387027.
Full text
3
Herfatmanesh, Mohammad Reza. "Investigation of single and split injection strategies in an optical diesel engine." Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/4776.
Full textAbstract:
This study investigates the effects of a split injection strategy on combustion performance and exhaust emissions in a high speed direct injection optical diesel engine. The investigation is focused on the effects of injection timing, quantity, and the dwell angle between the injections using commercially available diesel fuel. Three different split injection strategies including 50:50, 30:70, and 70:30 have been investigated. Additionally, the effect of total injected fuel quantity using total fuel quantities of 10 mm3 and 20 mm3 has been investigated. Moreover, the effect of variable and fixed dwell angle in split injections has been examined for five different values between 5o CA and 25o CA in the case of variable and 10o CA for the fixed dwell timing. The last parameter investigated was the injection timing, nine injection timings have been tested for each of the strategies. A Ricardo Hydra single cylinder optical engine running at 1500 rpm was used in this investigation. Conventional methods such as direct in-cylinder pressure measurements and heat release rate analysis have been employed. In addition, optical techniques such as high speed video imaging and two-colour have been applied, aimed at in depth analysis of the effects of the aforementioned parameters on engine performance and emissions. Furthermore, a significant amount of effort was devoted to the development and application of the Laser Induced Excipex Fluorescence (LIEF) technique so that simultaneous fuel liquid and fuel vapour distribution could be visualised. This investigation concludes that split injection strategies have the potential to reduce diesel exhaust emissions while maintaining a good level of fuel economy, provided that injection timings and the dwell angle between injections are appropriately selected. Further investigations are required in order to examine the effect of split injection under different engine operating conditions and speeds. In addition, the effect of alternative fuels must be considered. Moreover, the application of LIEF technique for quantitative fuel vapour concentration measurement should be considered through further optimisation of the LIEF system and careful calibration experiments.
4
Lai, Yi-Ying. "Injection-locked Optically Pumped Semiconductor Laser." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/577280.
Full textAbstract:
High-power, single-frequency, narrow-linewidth lasers emitting at tailored wavelength are desired for many applications, especially for precision spectroscopy. By way of a free-space resonator, optically pumped semiconductor lasers (OPSLs), a.k.a. vertical external-cavity surface-emitting lasers (VECSELs), can provide near diffraction-limited, high-quality Gaussian beams and are scalable in output power. Free space resonators also allow the insertion of the birefringent filter and the etalon to enforce single-frequency operation. In addition, the emission wavelengths of OPSLs are tailorable through bandgap engineering. These advantages above make OPSL a strong candidate of laser sources for spectroscopic applications including atomic spectroscopy as well as optical lattice clocks. In this research, a single-frequency laser source with high power is demonstrated by applying the injection-locking technique on OPSLs for the first time. The behaviors of the injection-locked OPSL are studied by varying parameters such as output coupling, injection wavelengths and injection power. It was found that the best injection wavelength is by approximately 2 nm shorter than the free-running slave laser at any given pump power. Below the lasing threshold for free-running operation, the laser starts the stimulated emission process as soon as it is pumped, working as a resonant amplifier. With proper parameters, the output power of the injection-locked laser exceeds the output power of its free-running condition. Over 9 W of single-frequency output power at 1015 nm is achieved. The output beam is near-diffraction-limited with Mₓ² = 1.04 and My² = 1.02. By analyzing the surface photoluminescence (PL) and the output performance of the laser, the saturation intensity of OPSLs is estimated to be 100 kW/cm² when the passive loss of 1.4% is assumed. The injection-locked system adds fairly low phase noise to that of the master laser. By measuring the beat note between the master laser and the injection-locked laser, the RMS values of the phase noise are 0.112 rad and 0.081 rad when using the T = 3% and T = 4% output couplers respectively.
5
Alavian, Sayyed Ahmad. "Modeling CO2 Injection in Fractured Reservoirs Using Single Matrix Block Systems." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-17374.
Full textAbstract:
In this thesis, CO2 injection in matrix/fracture systems has been studied using a finely-gridded compositional simulator representing a single matrix block. Three laboratory experiments were modeled to investigate whether CO2 injection in a fracture-matrix system could be simulated using commercial simulators that include basic fluid flow physics, phase behavior, and molecular diffusion. The first experiment was performed by Karimaie (2007) using an equilibrium, saturated gas-oil fluid system (C1-n-C7) at 220 bar and 85 oC. Because no recovery was expected from non-equilibrium thermodynamic mass transfer, reported recovery stemmed only from Darcy displacement driven by gravity and capillary forces. When the oil production stopped from the equilibrium gas displacement, a second injection period with pure CO2 followed. The numerical modeling was conducted using a compositional reservoir simulator (SENSOR) without diffusion. The 2-dimensional r-z model used fine grids for the core matrix and surrounding fracture. Automated history matching was used to determine parameters which were not accurately known (fracture permeability, fracture and matrix porosity, and separator conditions), using surface volumetric oil production rates reported experimentally. The final model match was relatively unique with a high degree of confidence in final model parameters. The oil recovery improved significantly with CO2 injection. Our model indicated that the recovery mechanism in the Karimaie experiment was dominated, for both equilibrium gas and CO2 injection, by top-to-bottom Darcy displacement caused by low conductivity in the artificial fracture; little impact of capillary-gravity displacement was found. Changes in CO2 injection rate had a significant impact on recovery performance. This experiment was also modeled using ECL300, with the same production performance as SENSOR for the set of history-match parameters determined without diffusion. When molecular diffusion was used in ECL300, results were nearly identical with those found without diffusion. Two other experiments were performed by Darvish (2007) at a higher temperature and pressure (130 oC and 300 bara) using a similar chalk and live reservoir oil. A similar modeling approach to that described above was also used for these experiments. In both experiments, the matching process based on reported oil production data gave a high degree of confidence in the model. The reported experimental mass fractions of produced-stream components were also matched well. Our modeling study indicates that gravity drainage affects the displacement process, but that mass transfer – including vaporization, condensation and molecular diffusion – also impact the recovery performance of CO2 injection in the Darvish experiments. The CO2 injection rate and initial water saturation were investigated by comparing the two Darvish experiments. Our studies from all of the Karimaie and Darvish experiments show a strong influence of the surface separator temperature on surface oil production, and this is an important consideration in designing and interpreting laboratory production data consistently. Once the laboratory recovery mechanisms had been successfully modeled, predictive numerical simulation studies were conducted on field-scale matrix/fractured systems, albeit mostly for single matrix blocks surrounded by a fracture. The effects of several key parameters on recovery production performance were studied in detail for field-scale systems: matrix permeability, matrix block size, matrix-matrix capillary continuity (stacked blocks), and the use of mixtures containing CO2 and hydrocarbon gas. The field-scale results were affected by gridding, so grid was refined to the degree necessary to achieve a more-or-less converged solution – i.e. recovery production performance didn’t change with further refinement. We studied the effect of molecular diffusion on oil recovery by CO2 injection in laboratory experiments and field-scale systems. Because the fluid systems considered had complex phase behavior and a wide range of conditions from strongly immiscible to near-miscible, the diffusion driving potential used was total component potential including chemical and gravity effects; concentrationdriven diffusion did not represent the more-complex non-equilibrium CO2 injection processes observed in the laboratory tests. A key result of this study was that diffusion can have an important effect on oil recovery, and that this effect varies with matrix block size and CO2 injection rate. We have shown that diffusion has a dominant effect on the recovery mechanism in experimental tests, except at very low rates of CO2 injection (and equilibrium hydrocarbon gas injection). For the field-scale matrix/fracture systems, diffusion can have a significant effect on the rate of recovery, with the effect becoming noticeable for low reservoir pressures and/or matrix block sizes less than ~40 ft.
6
Rodríguez, Álvaro Díez. "Investigation of split injection in a single cylinder optical diesel engine." Thesis, Brunel University, 2009. http://bura.brunel.ac.uk/handle/2438/3666.
Full textAbstract:
Over the last decade, the diesel engine has made dramatic progress in its performance and market penetration. However, in order to meet future emissions legislations, Nitrogen Oxide (NOx) and particulate matter (PM) emissions will need to be reduced simultaneously. Nowadays researchers are focused on different combustion modes like homogeneous charge compression ignition (HCCI) combustion and premixed charge compression ignition (PCCI) which have a great potential for both low soot and low NOx. In order to achieve these combustion modes, different injection strategies have been investigated. This study investigates the effects of split injection strategies with high levels of Exhaust Gas Recirculation (EGR) on combustion performance and emissions in a high speed direct injection optical diesel engine. The investigation is focused on the effects of split injections at different injection pressures, injection timings and dwell angles using base diesel and biodiesel fuels. The effect of fuel properties has been also investigated as an attempt to reduce regulated exhaust emissions in diesel engines. Performance, emissions and combustion characteristics have been examined for two different biodiesel fuels, namely BTL 50 and BTL 46. A Ricardo Hydra single cylinder optical engine was used in which conventional experimental methods like cylinder pressure data, heat release analysis and exhaust emissions analysis were applied. Optical techniques like direct spray and combustion visualization were applied by means of a high speed imaging system with a copper vapour laser illumination system. A high-speed two-colour system has been developed and implemented to obtain in-cylinder diesel combustion temperature and soot measurements to gain better understanding of the mixture formation and combustion processes. This investigation concludes that the split injection strategies show potential to achieve low emissions combustion.
7
Wiley, Paris D. "Fault tolerant design verification through the use of laser fault injection." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000226.
Full text
8
Jaksic, Marko Dragoljub. "Identification of small-signal dq impedances of power electronics converters via single-phase wide-bandwidth injection." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51222.
Full textAbstract:
AC and DC impedances of switching power converters are used for the stability analysis of modern power electronics systems at three-phase AC and single-phase DC interfaces. Therefore, a small-signal characterization algorithm for switching power converter, which is based on FFT, will be presented and explained. The presented extraction algorithm is general and can be used to obtain other small-signal transfer functions of arbitrary power converter switching simulation models. Furthermore, FFT algorithm is improved by using cross power spectral density functions for identification, resulting in an algorithm, which is more noise immune. Both small-signal identification algorithms are validated in simulations, and CPSD algorithm is used in experimental measurement procedure. Several wide bandwidth injection signals, among which are chirp, multi-tone, pulse and white noise, are compared and theoretically analyzed. Several hardware examples are included in the analysis.
The second part of the dissertation will focus on the modeling of small-signal input dq admittance of multi-pulse diode rectifiers, providing comparison between well-known averaged value models (AVMs), parametric averaged value models (PAVM), the switching simulation model and hardware measurements. Analytical expressions for all four admittances present in the dq matrix are derived and analyzed in depth, revealing the accuracy range of the averaged models. Furthermore, a hardware set-up is built, measured and modeled, showing that the switching simulation model captures nonlinear sideband effects accurately. In the end, a multi-pulse diode rectifier feeding a constant power load is analyzed with modified AVM and through detailed simulations of switching model, proving effectiveness of the proposed modifications.
The third part describes implementation and design of a single-phase multi-level single-phase shunt current injection converter based on cascaded H-bridge topology. Special attention is given toward the selection of inductors and capacitors, trying to optimize the selected component values and fully utilize operating range of the converter. The proposed control is extensively treated, including inner current, outer voltage loop and voltage balancing loops. The designed converter is constructed and integrated with measurement system, providing experimental verification. The proposed multi-level single-phase converter is a natural solution for single-phase shunt current injection with the following properties: modular design, capacitor energy distribution, reactive element minimization, higher equivalent switching frequency, capability to inject higher frequency signals, suitable to perturb higher voltage power systems and capable of generating cleaner injection signals.
Finally, a modular interleaved single-phase series voltage injection converter, consisting of multiple paralleled H-bridges is designed and presented. The decoupling control is proposed to regulate ac injection voltage, providing robust and reliable strategy for series voltage injection. The designed converter is simulated using detailed switching simulation model and excellent agreement between theory and simulation results are obtained. The presented control analysis treats different loads, examining robustness of the circuit to load variations. Simulation model and hardware prototype results verify the effectiveness of the proposed wide-bandwidth identification of small-signal dq impedances via single-phase injections.<br>Ph. D.
9
Wyman, Sandra J. "An optical method for measuring injection timing in diesel engines, using a single port." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/44031.
Full textAbstract:
Approved for public release; distribution is unlimited<br>This thesis is the design of a laser-induced fluorescence technique for use in the characterization of the fuel injection delay of various fuels, due to differences in bulk modulus. The technique is designed to work with an operational diesel engine having readily accessible glow-plug ports. The optical adapter designed for use through the glow-plug port is used as both the transmitting port for the excitation signal and the receiving port for the fluorescence signal. The prototype system was installed on a Detroit Diesel 3–53 two-stroke diesel engine. The beginning of the injection cycle is measured by a proximity probe set to detect injector compression to the point where the injector chamber is sealed. The actual entry of fuel into the cylinder is measured using laser induced fluorescence of an organic laser dye seeded fuel, excited by a 532-nm laser. The time/crank angle delay from the start of fuel compression to fuel entry into the cylinder can then be correlated to bulk modulus and cetane number. The combustion event can also be detected using the same optics and its timing correlated with known fuel properties.
10
Al-Hosiny, Najm M. "Nonlinear dynamics of a distributed feedback laser subject to single and dual optical injection." Thesis, University of Essex, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434393.
Full text
11
Evans, Adrian. "Techniques d'abstraction pour l'analyse et la mitigation des effets dus à la radiation." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT035/document.
Full textAbstract:
Les effets dus à la radiation peuvent provoquer des pannes dans des circuits intégrés. Lorsqu'une particule subatomique, fait se déposer une charge dans les régions sensibles d'un transistor cela provoque une impulsion de courant. Cette impulsion peut alors engendrer l'inversion d'un bit ou se propager dans un réseau de logique combinatoire avant d'être échantillonnée par une bascule en aval.Selon l'état du circuit au moment de la frappe de la particule et selon l'application, cela provoquera une panne observable ou non. Parmi les événements induits par la radiation, seule une petite portion génère des pannes. Il est donc essentiel de déterminer cette fraction afin de prédire la fiabilité du système. En effet, les raisons pour lesquelles une perturbation pourrait être masquée sont multiples, et il est de plus parfois difficile de préciser ce qui constitue une erreur. A cela s'ajoute le fait que les circuits intégrés comportent des milliards de transistors. Comme souvent dans le contexte de la conception assisté par ordinateur, les approches hiérarchiques et les techniques d'abstraction permettent de trouver des solutions.Cette thèse propose donc plusieurs nouvelles techniques pour analyser les effets dus à la radiation. La première technique permet d'accélérer des simulations d'injections de fautes en détectant lorsqu'une faute a été supprimée du système, permettant ainsi d'arrêter la simulation. La deuxième technique permet de regrouper en ensembles les éléments d'un circuit ayant une fonction similaire. Ensuite, une analyse au niveau des ensemble peut être faite, identifiant ainsi ceux qui sont les plus critiques et qui nécessitent donc d'être durcis. Le temps de calcul est ainsi grandement réduit.La troisième technique permet d'analyser les effets des fautes transitoires dans les circuits combinatoires. Il est en effet possible de calculer à l'avance la sensibilité à des fautes transitoires de cellules ainsi que les effets de masquage dans des blocs fréquemment utilisés. Ces modèles peuvent alors être combinés afin d'analyser la sensibilité de grands circuits. La contribution finale de cette thèse consiste en la définition d'un nouveau langage de modélisation appelé RIIF (Reliability Information Ineterchange Format). Ce langage permet de décrire le taux des fautes dans des composants simples en fonction de leur environnement de fonctionnement. Ces composants simples peuvent ensuite être combinés permettant ainsi de modéliser la propagation de leur fautes vers des pannes au niveau système. En outre, l'utilisation d'un langage standard facilite l'échange de données de fiabilité entre les partenaires industriels.Au-delà des contributions principales, cette thèse aborde aussi des techniques permettant de protéger des mémoires associatives ternaires (TCAMs). Les approches classiques de protection (codes correcteurs) ne s'appliquent pas directement. Une des nouvelles techniques proposées consiste à utiliser une structure de données qui peut détecter, d'une manière statistique, quand le résultat n'est pas correct. La probabilité de détection peut être contrôlée par le nombre de bits alloués à cette structure. Une autre technique consiste à utiliser un détecteur de courant embarqué (BICS) afin de diriger un processus de fond directement vers le région touchée par une erreur. La contribution finale consiste en un algorithme qui permet de synthétiser de la logique combinatoire afin de protéger des circuits combinatoires contre les fautes transitoires.Dans leur ensemble, ces techniques facilitent l'analyse des erreurs provoquées par les effets dus à la radiation dans les circuits intégrés, en particulier pour les très grands circuits composés de blocs provenant de divers fournisseurs. Des techniques pour mieux sélectionner les bascules/flip-flops à durcir et des approches pour protéger des TCAMs ont étés étudiées<br>The main objective of this thesis is to develop techniques that can beused to analyze and mitigate the effects of radiation-induced soft errors in industrialscale integrated circuits. To achieve this goal, several methods have been developedbased on analyzing the design at higher levels of abstraction. These techniquesaddress both sequential and combinatorial SER.Fault-injection simulations remain the primary method for analyzing the effectsof soft errors. In this thesis, techniques which significantly speed-up fault-injectionsimulations are presented. Soft errors in flip-flops are typically mitigated by selectivelyreplacing the most critical flip-flops with hardened implementations. Selectingan optimal set to harden is a compute intensive problem and the second contributionconsists of a clustering technique which significantly reduces the number offault-injections required to perform selective mitigation.In terrestrial applications, the effect of soft errors in combinatorial logic hasbeen fairly small. It is known that this effect is growing, yet there exist few techniqueswhich can quickly estimate the extent of combinatorial SER for an entireintegrated circuit. The third contribution of this thesis is a hierarchical approachto combinatorial soft error analysis.Systems-on-chip are often developed by re-using design-blocks that come frommultiple sources. In this context, there is a need to develop and exchange reliabilitymodels. The final contribution of this thesis consists of an application specificmodeling language called RIIF (Reliability Information Interchange Format). Thislanguage is able to model how faults at the gate-level propagate up to the block andchip-level. Work is underway to standardize the RIIF modeling language as well asto extend it beyond modeling of radiation-induced failures.In addition to the main axis of research, some tangential topics were studied incollaboration with other teams. One of these consisted in the development of a novelapproach for protecting ternary content addressable memories (TCAMs), a specialtype of memory important in networking applications. The second supplementalproject resulted in an algorithm for quickly generating approximate redundant logicwhich can protect combinatorial networks against permanent faults. Finally anapproach for reducing the detection time for errors in the configuration RAM forField-Programmable Gate-Arrays (FPGAs) was outlined
12
Jovanovic, N., C. Schwab, O. Guyon, et al. "Efficient injection from large telescopes into single-mode fibres: Enabling the era of ultra-precision astronomy." EDP SCIENCES S A, 2017. http://hdl.handle.net/10150/625827.
Full textAbstract:
Photonic technologies off er numerous advantages for astronomical instruments such as spectrographs and interferometers owing to their small footprints and diverse range of functionalities. Operating at the diffraction-limit, it is notoriously difficult to efficiently couple such devices directly with large telescopes. We demonstrate that with careful control of both the non-ideal pupil geometry of a telescope and residual wavefront errors, efficient coupling with single-mode devices can indeed be realised. A fibre injection was built within the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument. Light was coupled into a single-mode fibre operating in the near-IR (J-H bands) which was downstream of the extreme adaptive optics system and the pupil apodising optics. A coupling efficiency of 86% of the theoretical maximum limit was achieved at 1550 nm for a diffraction-limited beam in the laboratory, and was linearly correlated with Strehl ratio. The coupling efficiency was constant to within <30% in the range 1250-1600 nm. Preliminary on-sky data with a Strehl ratio of 60% in the H-band produced a coupling efficiency into a single-mode fibre of similar to 50%, consistent with expectations. The coupling was >40% for 84% of the time and >50% for 41% of the time. The laboratory results allow us to forecast that extreme adaptive optics levels of correction (Strehl ratio >90% in H-band) would allow coupling of >67% (of the order of coupling to multimode fibres currently) while standard levels of wavefront correction (Strehl ratio >20% in H-band) would allow coupling of >18%. For Strehl ratios <20%, few-port photonic lanterns become a superior choice but the signal-to-noise, and pixel availability must be considered. These results illustrate a clear path to efficient on-sky coupling into a single-mode fibre, which could be used to realise modal-noise-free radial velocity machines, very-long-baseline optical/near-IR interferometers and/or simply exploit photonic technologies in future instrument design.
13
Wang, Ziman. "Experimental study on diesel spray with single and multiple injection under room temperature and low temperature." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6123/.
Full textAbstract:
Multiple-injection strategy can downsize the penetration and boost the atomization, causing higher IMEP and lower emissions. Multiple-injection however is complex, especially under cold condition. The injection characteristics were first studied by applying long-tube measuring instrument. Single and split injection strategies were employed. The flow rate and fuel mass were quantitatively studied. Furthermore, the interaction among splits was linked to dwell interval and injection duration of each split. The influences of temperature were also studied. A microscope and a CCD camera were then employed to study the primary breakup. The regime for the mushroom spray head was analyzed and the dispersion quality was quantified. The breakup-regime study was carried out. Flow regimes in nozzle dominate the breakup. Dwell interval, injection pressure, the number of injections and fuel temperature determined the interaction. The following is the investigation of macroscopic characteristics with high speed imaging technique. The effects of back pressure and the interaction between injections were investigated. The impact of cold fuel temperature was investigated and various correlations were employed to probe the influence of fuel temperature. The velocities and sizes of droplets were finally studied with Phase Doppler Particle Analyzer.
14
Rains, Adam D., Michael J. Ireland, Nemanja Jovanovic, et al. "Precision single mode fibre integral field spectroscopy with the RHEA spectrograph." SPIE-INT SOC OPTICAL ENGINEERING, 2016. http://hdl.handle.net/10150/622808.
Full textAbstract:
The RHEA Spectrograph is a single-mode echelle spectrograph designed to be a replicable and cost effective method of undertaking precision radial velocity measurements. Two versions of RHEA currently exist, one located at the Australian National University in Canberra, Australia (450 - 600nm wavelength range), and another located at the Subaru Telescope in Hawaii, USA (600 - 800 nm wavelength range). Both instruments have a novel fibre feed consisting of an integral field unit injecting light into a 2D grid of single mode fibres. This grid of fibres is then reformatted into a 1D array at the input of the spectrograph (consisting of the science fibres and a reference fibre capable of receiving a white-light or xenon reference source for simultaneous calibration). The use of single mode fibres frees RHEA from the issue of modal noise and significantly reduces the size of the optics used. In addition to increasing the overall light throughput of the system, the integral field unit allows for cutting edge science goals to be achieved when operating behind the 8.2 m Subaru Telescope and the SCExAO adaptive optics system. These include, but are not limited to: resolved stellar photospheres; resolved protoplanetary disk structures; resolved Mira shocks, dust and winds; and sub-arcsecond companions. We present details and results of early tests of RHEA Subaru and progress towards the stated science goals.
15
Costenaro, Enrico. "Techniques pour l'évaluation et l'amélioration du comportement des technologies émergentes face aux fautes aléatoires." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT137/document.
Full textAbstract:
L'objectif principal de cette thèse est de développer des techniques d'analyse et mitigation capables à contrer les effets des Evènements Singuliers (Single Event Effects) - perturbations externes et internes produites par les particules radioactives, affectant la fiabilité et la sureté en fonctionnement des circuits microélectroniques complexes. Cette thèse à la vocation d'offrir des solutions et méthodologies industrielles pour les domaines d'applications terrestres exigeant une fiabilité ultime (télécommunications, dispositifs médicaux, ...) en complément des travaux précédents sur les Soft Errors, traditionnellement orientés vers les applications aérospatiales, nucléaires et militaires.Les travaux présentés utilisent une décomposition de sources d'erreurs dans les circuits actuels, visant à mettre en évidence les contributeurs les plus importants.Les upsets (SEU) - Evènements Singuliers (ES) dans les cellules logiques séquentielles représentent actuellement la cible principale pour les efforts d'analyse et d'amélioration à la fois dans l'industrie et dans l'académie. Cette thèse présente une méthodologie d'analyse basée sur la prise en compte de la sensibilité de chaque état logique d'une cellule (state-awareness), approche qui améliore considérablement la précision des résultats concernant les taux des évènements pour les instances séquentielles individuelles. En outre, le déséquilibre intrinsèque entre la susceptibilité des différents états des bascules est exploité pour mettre en œuvre une stratégie d'amélioration SER à très faible coût.Les fautes transitoires (SET) affectant la logique combinatoire sont beaucoup plus difficiles à modéliser, à simuler et à analyser que les SEUs. L'environnement radiatif peut provoquer une multitude d'impulsions transitoires dans les divers types de cellules qui sont utilisés en configurations multiples. Cette thèse présente une approche pratique pour l'analyse SET, applicable à des circuits industriels très complexes. Les principales étapes de ce processus consiste à: a) caractériser complètement la bibliothèque de cellules standard, b) évaluer les SET dans les réseaux logiques du circuit en utilisant des méthodes statiques et dynamiques et c) calculer le taux SET global en prenant en compte les particularités de l'implémentation du circuit et de son environnement.L'injection de fautes reste la principale méthode d'analyse pour étudier l'impact des fautes, erreurs et disfonctionnements causés par les évènements singuliers. Ce document présente les résultats d'une analyse fonctionnelle d'un processeur complexe dans la présence des fautes et pour une sélection d'applications (benchmarks) représentatifs. Des techniques d'accélération de la simulation (calculs probabilistes, clustering, simulations parallèles) ont été proposées et évalués afin d'élaborer un environnement de validation industriel, capable à prendre en compte des circuits très complexes. Les résultats obtenus ont permis l'élaboration et l'évaluation d'un hypothétique scénario de mitigation qui vise à améliorer sensiblement, et cela au moindre coût, la fiabilité du circuit sous test. Les résultats obtenus montrent que les taux d'erreur, SDC (Silent Data Corruption) et DUE (Detectable Uncorrectable Errors) peuvent être considérablement réduits par le durcissement d'un petite partie du circuit (protection sélective). D'autres techniques spécifiques ont été également déployées: mitigation du taux de soft-errors des Flip-Flips grâce à une optimisation du Temporal De-Rating par l'insertion sélective de retard sur l'entrée ou la sortie des bascules et biasing du circuit pour privilégier les états moins sensibles.Les méthodologies, algorithmes et outils CAO proposés et validés dans le cadre de ces travaux sont destinés à un usage industriel et ont été valorisés dans le cadre de plateforme CAO commerciale visant à offrir une solution complète pour l'évaluation de la fiabilité des circuits et systèmes électroniques complexes<br>The main objective of this thesis is to develop analysis and mitigation techniques that can be used to face the effects of radiation-induced soft errors - external and internal disturbances produced by radioactive particles, affecting the reliability and safety in operation complex microelectronic circuits. This thesis aims to provide industrial solutions and methodologies for the areas of terrestrial applications requiring ultimate reliability (telecommunications, medical devices, ...) to complement previous work on Soft Errors traditionally oriented aerospace, nuclear and military applications.The work presented uses a decomposition of the error sources, inside the current circuits, to highlight the most important contributors.Single Event Effects in sequential logic cells represent the current target for analysis and improvement efforts in both industry and academia. This thesis presents a state-aware analysis methodology that improves the accuracy of Soft Error Rate data for individual sequential instances based on the circuit and application. Furthermore, the intrinsic imbalance between the SEU susceptibility of different flip-flop states is exploited to implement a low-cost SER improvement strategy.Single Event Transients affecting combinational logic are considerably more difficult to model, simulate and analyze than the closely-related Single Event Upsets. The working environment may cause a myriad of distinctive transient pulses in various cell types that are used in widely different configurations. This thesis presents practical approach to a possible exhaustive Single Event Transient evaluation flow in an industrial setting. The main steps of this process consists in: a) fully characterize the standard cell library using a process and library-aware SER tool, b) evaluate SET effects in the logic networks of the circuit using a variety dynamic (simulation-based) and static (probabilistic) methods and c) compute overall SET figures taking into account the particularities of the implementation of the circuit and its environment.Fault-injection remains the primary method for analyzing the effects of soft errors. This document presents the results of functional analysis of a complex CPU. Three representative benchmarks were considered for this analysis. Accelerated simulation techniques (probabilistic calculations, clustering, parallel simulations) have been proposed and evaluated in order to develop an industrial validation environment, able to take into account very complex circuits. The results obtained allowed the development and evaluation of a hypothetical mitigation scenario that aims to significantly improve the reliability of the circuit at the lowest cost.The results obtained show that the error rate, SDC (Silent Data Corruption) and DUE (Detectable Uncorrectable Errors) can be significantly reduced by hardening a small part of the circuit (Selective mitigation).In addition to the main axis of research, some tangential topics were studied in collaboration with other teams. One of these consisted in the study of a technique for the mitigation of flip-flop soft-errors through an optimization of the Temporal De-Rating (TDR) by selectively inserting delay on the input or output of flip-flops.The Methodologies, the algorithms and the CAD tools proposed and validated as part of the work are intended for industrial use and have been included in a commercial CAD framework that offers a complete solution for assessing the reliability of circuits and complex electronic systems
16
Kastensmidt, Fernanda Gusmão de Lima. "Designing single event upset mitigation techniques for large SRAM-Based FPGA components." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2003. http://hdl.handle.net/10183/4181.
Full textAbstract:
Esse trabalho consiste no estudo e desenvolvimento de técnicas de proteção a falhas transientes, também chamadas single event upset (SEU), em circuitos programáveis customizáveis por células SRAM. Os projetistas de circuitos eletrônicos estão cada vez mais predispostos a utilizar circuitos programáveis, conhecidos como Field Programmable Gate Array (FPGA), para aplicações espaciais devido a sua alta flexibilidade lógica, alto desempenho, baixo custo no desenvolvimento, rapidez na prototipação e principalmente pela reconfigurabilidade. Em particular, FPGAs customizados por SRAM são muito importantes para missões espaciais pois podem ser rapidamente reprogramados à distância quantas vezes for necessário. A técnica de proteção baseada em redundância tripla, conhecida como TMR, é comumente utilizada em circuitos integrados de aplicações específicas e pode também ser aplicada em circuitos programáveis como FPGAs. A técnica TMR foi testada no FPGA Virtex® da Xilinx em aplicações como contadores e micro-controladores. Falhas foram injetadas em todos as partes sensíveis da arquitetura e seus efeitos foram detalhadamente analisados. Os resultados de injeção de falhas e dos experimentos sob radiação em laboratório comprovaram a eficácia do TMR em proteger circuitos sintetizados em FPGAs customizados por SRAM. Todavia, essa técnica possui algumas limitações como aumento em área, uso de três vezes mais pinos de entrada e saída (E/S) e conseqüentemente, aumento na dissipação de potência. Com o objetivo de reduzir custos no TMR e melhorar a confiabilidade, uma técnica inovadora de tolerância a falhas para FPGAs customizados por SRAM foi desenvolvida para ser implementada em alto nível, sem modificações na arquitetura do componente. Essa técnica combina redundância espacial e temporal para reduzir custos e assegurar confiabilidade. Ela é baseada em duplicação com um circuito comparador e um bloco de detecção concorrente de falhas. Esta nova técnica proposta neste trabalho foi especificamente projetada para tratar o efeito de falhas transientes em blocos combinacionais e seqüenciais na arquitetura reconfigurável, reduzir o uso de pinos de E/S, área e dissipação de potência. A metodologia foi validada por injeção de falhas emuladas em uma placa de prototipação. O trabalho mostra uma comparação nos resultados de cobertura de falhas, área e desempenho entre as técnicas apresentadas.<br>This thesis presents the study and development of fault-tolerant techniques for programmable architectures, the well-known Field Programmable Gate Arrays (FPGAs), customizable by SRAM. FPGAs are becoming more valuable for space applications because of the high density, high performance, reduced development cost and re-programmability. In particular, SRAM-based FPGAs are very valuable for remote missions because of the possibility of being reprogrammed by the user as many times as necessary in a very short period. SRAM-based FPGA and micro-controllers represent a wide range of components in space applications, and as a result will be the focus of this work, more specifically the Virtex® family from Xilinx and the architecture of the 8051 micro-controller from Intel. The Triple Modular Redundancy (TMR) with voters is a common high-level technique to protect ASICs against single event upset (SEU) and it can also be applied to FPGAs. The TMR technique was first tested in the Virtex® FPGA architecture by using a small design based on counters. Faults were injected in all sensitive parts of the FPGA and a detailed analysis of the effect of a fault in a TMR design synthesized in the Virtex® platform was performed. Results from fault injection and from a radiation ground test facility showed the efficiency of the TMR for the related case study circuit. Although TMR has showed a high reliability, this technique presents some limitations, such as area overhead, three times more input and output pins and, consequently, a significant increase in power dissipation. Aiming to reduce TMR costs and improve reliability, an innovative high-level technique for designing fault-tolerant systems in SRAM-based FPGAs was developed, without modification in the FPGA architecture. This technique combines time and hardware redundancy to reduce overhead and to ensure reliability. It is based on duplication with comparison and concurrent error detection. The new technique proposed in this work was specifically developed for FPGAs to cope with transient faults in the user combinational and sequential logic, while also reducing pin count, area and power dissipation. The methodology was validated by fault injection experiments in an emulation board. The thesis presents comparison results in fault coverage, area and performance between the discussed techniques.
17
Melin, Jonas. "Single-Molecule Detection and Optical Scanning in Miniaturized Formats." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7268.
Full text
18
Morris, Claude. "Grid-connected transformerless single-phase photovoltaic inverters: an evaluation on DC current injection and PV array voltage fluctuation." Thesis, Morris, Claude (2009) Grid-connected transformerless single-phase photovoltaic inverters: an evaluation on DC current injection and PV array voltage fluctuation. Other thesis, Murdoch University, 2009. https://researchrepository.murdoch.edu.au/id/eprint/3245/.
Full textAbstract:
A number of political, environmental and technical factors have resulted in the increase of implementation of renewable technology including grid connected photovoltaic inverters. As a result, new topologies for grid connected inverters providing higher efficiencies and lower manufacturing costs have been developed. In particular, designs utilising transformerless topologies have steadily increased. While there are clear associated advantages of implementing these new transformerless topologies, new potential issues such as DC current injection and capacitive leakage currents are introduced. Part A of this report presents a clearly defined test circuit setup and procedure for testing DC current injection for grid-connected single-phase photovoltaic inverters implementing both transformerless and high frequency transformer topologies. The results demonstrated that the test circuit setup and testing procedure is suitable for inclusion in a future amendment to AS4777.2. It is however proposed that before these amendments are recommended, further investigation is required to determine what power levels all inverters are required to be tested at and how many tests per inverter are required. Part B of this report defines and models a variety of transformerless inverter topologies, switching schemes and output filter configurations and clearly defines their operation. All of these various models have been simulated to determine which designs are suitable for applications in regards to reducing capacitive leakage currents in an effort to eliminate potential risks to users and to ensure electromagnetic compatability. Two commercially available and one anonymous Grid-connected Transformerless Single-phase Photovoltaic Inverter models utilising a selection of the simulated topologies and switching schemes were experimentally tested to verify simulated results.
19
Fu, Tingrui. "PP/clay nanocomposites : compounding and thin-wall injection moulding." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/24655.
Full textAbstract:
This research investigates formulation, compounding and thin-wall injection moulding of Polypropylene/clay nanocomposites (PPCNs) prepared using conventional melt-state processes. An independent study on single screw extrusion dynamics using Design of Experiments (DoE) was performed first. Then the optimum formulation of PPCNs and compounding conditions were determined using this strategy. The outcomes from the DoE study were then applied to produce PPCN compounds for the subsequent study of thin-wall injection moulding, for which a novel four-cavity injection moulding system was designed using CAD software and a new moulding tool was constructed based upon this design. Subsequently, the effects of moulding conditions, nanoclay concentration and wall thickness on the injection moulded PPCN parts were investigated. Moreover, simulation of the injection moulding process was carried out to compare the predicted performance with that obtained in practice by measurement of real-time data using an in-cavity pressure sensor. For the selected materials, the optimum formulation is 4 wt% organoclay (DK4), 4 wt% compatibiliser (Polybond 3200, PPgMA) and 1.5 wt% co-intercalant (erucamide), as the maximum interlayer spacing of clay can be achieved in the selected experimental range. Furthermore, DoE investigations determined that a screw speed of 159 rpm and a feed rate of 5.4 kg/h are the optimum compounding conditions for the twin screw extruder used to obtain the highest tensile modulus and yield strength from the PPCN compounds. The optimised formulation of PPCNs and compounding conditions were adopted to manufacture PPCN materials for the study of thin-wall injection moulding. In the selected processing window, tensile modulus and yield strength increase significantly with decreasing injection speed, due to shear-induced orientation effects, exemplified by a significantly increased frozen layer thickness observed by optical microscopy (OM) and Moldflow® simulation. Furthermore, the TEM images indicate a strong orientation of clay particles in the flow direction, so the PPCN test pieces cut parallel to the flow direction have 36.4% higher tensile modulus and 13.6 % higher yield strength than those cut perpendicular to the flow direction, demonstrating the effects of shear induced orientation on the tensile properties of thin-wall injection moulded PPCN parts. In comparison to injection speed, mould temperature has very limited effects in the selected range investigated (25-55 °C), in this study. The changes in moulding conditions show no distinctive effects on PP crystallinity and intercalation behaviour of clay. Impact toughness of thin wall injection moulded PPCN parts is not significantly affected by either the changes in moulding conditions or clay concentration (1-5 %). The SEM images show no clear difference between the fracture surfaces of PPCN samples with different clay concentrations. TEM and XRD results suggest that higher intercalation but lower exfoliation is achieved in PPCN parts with higher clay content. The composites in the thin sections (at the end of flow) have 34 % higher tensile modulus and 11 % higher yield strength than in the thicker sections, although the thin sections show reduced d001 values. This is attributed to the significantly enhanced shear-induced particle/molecular orientation and more highly oriented frozen layer, according to TEM, OM and process simulation results. In terms of the reduced d001 values in the thin sections, it is proposed that the extreme shear conditions in the thin sections stretch the PP chains in the clay galleries to a much higher level, compaction of clay stacks occurs as less interspacing is needed to accommodate the stretched chains, but rapid cooling allows no time for the chains to relax and expand the galleries back. Overall, data obtained from both actual moulding and simulation indicate that injection speed is of utmost importance to the thin-wall injection moulding process, development of microstructure, and thus the resulting properties of the moulded PPCN parts, in the selected experimental ranges of this research.
20
Kodama, Itsuo, Toyoaki Murohara, Kenji Kadomatsu, et al. "A single intracoronary injection of midkine reduces ischemia/reperfusion injury in Swine hearts: a novel therapeutic approach for acute coronary syndrome." Thesis, Frontiers Media SA, 2011. http://hdl.handle.net/2237/16801.
Full text
21
Krieger, Brian L. "Rapid automated calibration using discontinuous flow analysis and sequential injection." Thesis, Queensland University of Technology, 1998.
Find full text
22
Liu, Quan. "Planar laser induced fluorescence imaging and analysis with ethanol blended fuels in a direct injection spark ignition engine." Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/14786.
Full textAbstract:
The currently reported thesis was concerned with visualisation of the charge homogeneity and cyclic variations within the planar fuel field near the spark plug in an optical spark ignition engine fitted with an outwardly opening central direct fuel injector. Specifically, the project examined the effects of fuel type and injection settings, with the overall view to understanding some of the key mechanisms previously identified as leading to particulate formation in such engines. The three fuels studied included a baseline iso-octane, which was directly compared to two gasoline fuels containing 10% (E10) and 85% (E85) volume of ethanol respectively. The engine was a bespoke single cylinder with Bowditch style optical access through a flat piston crown. Charge stratification was studied over a wide spectrum of injection timings using the Planar Laser Induced Fluorescence (PLIF) technique, with additional variation in charge temperature due to injection also estimated when viable using a two-line PLIF approach. Overall, both gasoline-ethanol fuels generally exhibited a higher degree of stratification, albeit at least partly alleviated with elevated rail pressures. Under both warm and cold liner conditions the E10 fuel showed clear evidence of fuel droplets persisting up until ignition. Interestingly, with late injection timing the repeatability of the injection was superior (statistically) with higher ethanol content in the fuel, which may have been associated with the higher charge temperatures aiding control of the evaporation of the main mass of alcohol. The findings were corroborated by undertaking a comprehensive study of the influence of varying fuel type and injection settings on thermodynamic performance and engine-out emissions during firing operation, with additional gas exchange effects also influencing the optimum fuel injection timings.
23
Mansour, Wassim. "Méthodes et outils pour l'analyse tôt dans le flot de conception de la sensibilité aux soft-erreurs des applications et des circuits intégrés." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00838415.
Full textAbstract:
La miniaturisation des gravures des transistors résulte en une augmentation de la sensibilité aux soft-erreurs des circuits intégrés face aux particules énergétiques présentes dans l'environnement dans lequel ils opèrent. Une expérimentation, présentée au cours de cette thèse, concernant l'étude de la sensibilité face aux soft-erreurs, dans l'environnement réel, des mémoires SRAM provenant de deux générations de technologies successives, a mis en évidence la criticité de cette thématique. Cela pour montrer la nécessité de l'évaluation des circuits faces aux effets des radiations, surtout les circuits commerciaux qui sont de plus en plus utilisés dans les applications spatiales et avioniques et même dans les hautes altitudes, afin de trouver les méthodologies permettant leurs durcissements. Plusieurs méthodes d'injection de fautes, ayant pour but l'évaluation de la sensibilité des circuits intégrés face aux soft-erreurs, ont été le sujet de plusieurs recherches. Les travaux réalisés au cours de cette thèse ont eu pour but le développement d'une méthode automatisable, avec son outil, permettant l'émulation des effets des radiations sur des circuits dont on dispose de leurs codes HDL. Cette méthode, appelée NETFI (NETlist Fault Injection), est basée sur la manipulation de la netlist du circuit synthétisé pour permettre l'injection de fautes de types SEU, SET et Stuck_at. NETFI a été appliquée sur plusieurs architectures pour étudier ses potentialités ainsi que son efficacité. Une étude sur un algorithme tolérant aux fautes, dit self-convergent, exécuté par un processeur LEON3, a été aussi présenté dans le but d'effectuer une comparaison des résultats issus de NETFI avec ceux issus d'une méthode de l'état de l'art appelée CEU (Code Emulated Upset).
24
Lafleur, Isabelle. "Changes in adult behavior following a single neonatal injection of NMDA antagonist AP-5 in different rat brain regions." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29450.
Full textAbstract:
Neonatal excitotoxic lesions of rat ventral hippocampus (nVH) have been demonstrated to induce post-pubertal behavior and neurochemical alterations analogous to those observed in schizophrenia (Sams-Dodd et al., 1997; Flores et al., 1996A; Lipska et al., 1995; and Lipska et al., 1993). To better characterize the mechanism of nVH lesions, we have examined the effects of transient glutamatergic blockade on the major output structures of VH, namely nucleus accumbens, cingulate prefrontal cortex, infralimbic prefrontal cortex and ventral tegmental area. A single bilateral injection of NMDA antagonist D-2-amino-5-phosphonopentonoic acid (AP-5) was administrated stereotaxically into male neonatal Sprague-Dawley rat at postnatal day 7. Animals were subsequently tested for alteration in prepulse inhibition, locomotor activity, social interaction and anxiety pre- and postpubertally. Histological study was also made to determine the nature of neurodevelopmental damage. The results suggest a development window of glutamatergic activity critical for mediating long-term adult behaviors.
25
Giangarra, Jenna Elizabeth. "Effect of a single intra-articular injection of bupivacaine on synovial fluid prostaglandin E2 concentrations in normal canine stifles." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/95970.
Full textAbstract:
Intra-articular bupivacaine is a common analgesic used in dogs with orthopedic disease. Bupivacaine has been linked to chondrotoxicity. The mechanism for bupivacaine's chondrotoxicity is unknown, but may involve inflammation. Prostaglandin E2 (PGE2) is an inflammatory mediator and a marker of joint inflammation. The aim of this study was to compare synovial fluid PGE2 concentrations after a single intra-articular injection of bupivacaine with a saline control in normal canine stifles. We hypothesized that bupivacaine stifles would have a significantly elevated PGE2 concentration compared to controls. Stifles from eight healthy, adult Beagles were randomly selected as the treated stifle and infused with bupivacaine. The contralateral stifle was injected with saline. Synovial fluid was collected before and after injection. PGE2 was quantified using a commercial ELISA. Data were transformed and mixed model ANOVA was performed with significance set at p<0.05. There were no significant differences in PGE2 concentration between treatment groups or times. Samples acquired with one or two aspiration attempts had significantly lower PGE2 concentrations than samples with =3 aspiration attempts (p=0.001). When adjusted for number of attempts, PGE2 concentrations were significantly higher 24 (p=0.003) and 48 (p=0.041) hours after injection compared to baseline in the bupivacaine group, but not in the saline group. Intra-articular bupivacaine injection did not result in increased synovial fluid PGE2 concentrations compared to controls; however, multiple aspiration attempts did, suggesting that synovial fluid PGE2 concentration is sensitive to multiple fluid collection attempts. Future studies investigating synovial fluid inflammatory mediators should consider methods to minimize aspiration attempts.<br>M. S.
26
Timpanaro, Anthony. "Reduction of NOx Emissions in a Single Cylinder Diesel Engine Using SNCR with In-Cylinder Injection of Aqueous Urea." UNF Digital Commons, 2019. https://digitalcommons.unf.edu/etd/876.
Full textAbstract:
The subject of this study is the effect of in-cylinder selective non-catalytic reduction (SNCR) of NOx emissions in diesel exhaust gas by means of direct injection of aqueous urea ((NH2)2CO) into the combustion chamber. A single cylinder diesel test engine was modified to accept an electronically controlled secondary common rail injection system to deliver the aqueous urea directly into the cylinder during engine operation.
Direct in-cylinder injection was chosen in order to ensure precise delivery of the reducing agent without the risk of any premature reactions taking place. Unlike direct in-cylinder injection of neat water, aqueous urea also works as a reducing agent by breaking down into ammonia (NH3) and Cyanuric Acid ((HOCN)3). These compounds serve as the primary reducing agents in the NOx reduction mechanism explored here. The main reducing agent, aqueous urea, was admixed with glycerol (C3H8O3) in an 80-20 ratio, by weight, to function as a lubricant for the secondary injector.
The aqueous urea injection timing and duration is critical to the reduction of NOx emissions due to the dependence of SNCR NOx reduction on critical factors such as temperature, pressure, reducing agent to NOx ratio, Oxygen and radical content, residence time and NH3 slip. From scoping engine tests at loads of 40 percent and 80 percent at 1500 rpm, an aqueous urea injection strategy was developed. The final injection strategy chosen was four molar ratios, 4.0, 2.0, 1.0 and 0.5 with five varying injection timings of 60, 20, 10, 0, and -30 degrees after top dead center (ATDC). In addition to the base line and aqueous urea tests, water injection and an 80-20 water-glycerol solution reduction agent tests were also conducted to compare the effects of said additives as well. The comparison of baseline and SNCR operation was expected to show that the urea acted as a reducing agent, lowering NOx emissions up to 100% (based on exhaust stream studies) in the diesel exhaust gas without the aid of a catalyst.
The data collected from the engine tests showed that the aqueous urea-glycerol solution secondary had no effect on the reduction of NOx and even resulted in an increase of up to 5% in some tests. This was due to the low average in-cylinder temperature as well as a short residence time, prohibiting the reduction reaction from taking place. The neat water and water-glycerol solution secondary injection was found to have a reduction effect of up to 59% on NOx production in the emissions due to the evaporative cooling effect and increased heat capacity of the water.
27
LANGE, THOMAS. "New Reliable Operation Infrastructure for Dynamic, High-dependability Applications." Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2935598.
Full text
28
Kim, Chung-Gong. "A crank angle resolved CIDI engine combustion model with arbitrary fuel injection for control purpose." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5num=osu1086154960.
Full textAbstract:
Thesis (Ph. D.)--Ohio State University, 2004.<br>Title from first page of PDF file. Document formatted into pages; contains xxiv, 266 p. : ill. (some col.). Advisor: Yann G. Guezennec, Dept. of Mechanical Engineering. Includes bibliographical references (p. 259-266).
29
Shahverdi, Ali. "Synthesis of chemically-modified single-walled carbon nanotubes by counter-current ammonia gas injection into the induction thermal plasma process." Thèse, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6630.
Full textAbstract:
Résumé : Les nanotubes de carbone mono-parois (SWCNTs) sont très peu dispersibles dans les solvants et ils ont besoin d'être chimiquement modifiés avant leur utilisation dans beaucoup d'applications. Ce travail se concentre sur la synthèse du matériau des SWCNTs chimiquement modifié par une approche in situ. Les objectifs principaux de cette recherche sont : I) explorer le procédé chimique in situ pendant la synthèse des SWCNTs et 2) examiner de manière approfondie l'effet de l'environnement réactif sur les SWCNTs. Les effets du type de catalyseur et son contenu sur le produit fini des SWCNTs, synthétisé par plasma thermique inductif (PTI), ont été étudiés pour remplacer le cobalt (Co) toxique dans la matière première. À cet égard, trois mélanges de catalyseurs différents (c.-à-d. Ni-Y203, Ni-Co-Y203, et Ni-Mo-Y203) ont été utilisés. Les résultats expérimentaux ont montré que le type de catalyseur affecte la qualité des SWCNTs. Une qualité similaire peut être produite lorsque la même quantité de Co est remplacée par le Ni. En outre, des résultats observés dans les travaux expérimentaux ont été explicités par les résultats des calculs thermodynamiques. La therrnogravimétrie (TG) a été utilisée tout au long du travail pour caractériser les échantillons de SWCNTs. La TG a tout d'abord été normalisée par l'étude des effets des trois principaux paramètres instrumentaux (rampe de température, RT, la masse initiale de l'échantillon, MI, et le débit de gaz, D) sur le T, et largeur à mi-hauteur (LMH) obtenu à partir de graphiques TG et TG dérivés de noir de carbone, respectivement. Par conséquent, un plan factoriel à deux niveaux a été prévu. L'analyse statistique a montré que l'effet de RT, MI, et à un degré moindre D est significatif sur la LMH et négligeable sur Tonss. Une méthodologie a ensuite été développée sur la base de la synthèse des SWCNT en utilisant le système PTI, à travers une approche chimique in situ. L'ammoniac (NH3) a été choisi et injecté à contre-courant dans le réacteur PTI à trois débits différents et en utilisant quatre types de buses différentes. La simulation numérique a indiqué un meilleur mélange du NH3 dans le réacteur PTI lorsqu'une buse particulière a été utilisée. Les résultats expérimentaux montrent l'augmentation d'intensité de D-bande dans les spectres Raman d'échantillons SWCNTs lors de l'injection du NH3. Le NH3 pourrait augmenter la teneur en azote du produit fini de SWCNTs jusqu'à 10 fois. L'échantillon des SWCNTs traitée avec 15% vol de NH3 a montré une dispersion accrue dans le diméthylformamide et l'isopropanol. Les nanostructures de carbone en forme d'oignon et plane, ont aussi été observées. Une caractérisation complémentaire sur l'échantillon des SWCNTs traités par NH3 à 15% vol., a indiqué une modification de la surface des nanotubes, où des tubes métalliques ont montré une plus grande réactivité avec NH3 que les semi-conducteurs. Le modèle, y compris le champ d'écoulement thermique du réacteur et la cinétique de décomposition thermique de NH3 a suggéré une modification de surface des SWCNTs en deux étapes dans laquelle les nanotubes réagissent premièrement avec les espèces intermédiaires de H et de NH2. Le NH3 s'adsorbe ensuite chimiquement sur les nanotubes. Le modèle a également suggéré que les espèces intermédiaires comme le NNH et le N2H2 jouent un rôle principalement en conduisant la décomposition du NH3 plutôt que la modification chimique des SWCNTs. // Abstract : Pristine single-walled carbon nanotubes (SWCNTs) are poorly dispersible and insoluble in many solvents and need to be chemically modified prior to their use in many applications. This work is focused on the investigation of the synthesis of chemically modified SWCNTs material through an in situ approach. The main objectives of the presented research are: I) to explore the in situ chemical process during the synthesis of SWCNT and 2) to closely examine the effect of a reactive environment on SWCNTs. Effects of the catalyst type and content on the SWCNTs final product, synthesized by induction thermal plasma (1TP), were studied to replace toxic cobalt (Co) in the feedstock. In this regard, three different catalyst mixtures (i.e. Ni-Y203, Ni-Co-Y203, and Ni-Mo-Y203) were used. Experimental results showed that the catalyst type affects the quality of the SWCNT final product. Similar quality SWCNTs can be produced when the same amount of Co was replaced by Ni. Moreover, the results observed in this experimental work were further explained by thermodynamic calculation results. Thermogravimetry (TG) was used throughout the work to characterize the SWCNTs product. TG was firstly standardized by studying the effects of three main instrumental parameters (temperature ramp, TR, initial mass of the sample, 1M, and gas flow rate, FR) on the Lise, and full-width half maximum (FWHM) obtained from TG and derivative TG graphs of carbon black, respectively. Therefore, a two-level factorial statistical design was performed. The statistical analysis showed that the effect of TR, IM, and to a lower extent, FR, is significant on FWHM and insignificant on T01, 1. A methodology was then developed based upon the SWCNTs synthesis using the 1TP system, through an in situ chemistry approach. Ammonia (NH3) was selected and counter-currently injected into the ITP reactor at three different flow rates and by four different nozzle designs. Numerical simulation indicated a better mixing of NH3 in the ITP reactor when a certain nozzle was used. The experimental results showed the increase of D-band intensity in the Raman spectra of SWCNT samples upon the NH3 injection. NH3 could increase the nitrogen content of the SWCNTs final product up to 10 times. The SWCNTs sample treated with 15 vol% NH3 showed an enhanced dispersibility in Dimethylformamide and Isopropanol. Onion-like and planar carbon nanostructures were also observed. Complementary characterization on the SWCNT samples treated by 15 vol% NH3 indicated the surface modification of nanotubes. Metallic tubes showed a higher reactivity with NH3 than semiconducting ones. The model including the reactor thermo-flow field and NH3 thermal decomposition kinetics suggested a two-step SWCNT surface modification in which nanotubes firstly react with H and NH2 intermediates and later, NH3 chemisorbs on the nanotubes. The model also suggested that the intermediate species, like NNH and N2H2, play a rote primarily in driving the NH3 decomposition rather than the chemical modification of SWCNTs. [symboles non conformes]
30
Illman, Walter A. "Single- and cross-hole pneumatic injection tests in unsaturated fractured tuffs at the Apache Leap Research Site near Superior, Arizona." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/284217.
Full textAbstract:
This dissertation documents research results from a series of field experiments and analyses used to test interpretive models for investigating the role of fractures in fluid flow through unsaturated, fractured tuffs. It summarizes the experimental design of single- and cross-hole pneumatic injection tests, including borehole configuration and testing schedules, data collection system, interpretive models developed and tested, data, and conclusions. Single-hole tests were interpreted by Guzman et al. (1996) by means of steady-state analysis to obtain permeability values based solely on late pressure data. This dissertation and Illman et al. (1998) employ pressure and pressure-derivative type-curves to analyze transient data. Air permeabilities determined from transient analyses agree well with those derived from steady-state analyses. Cross-hole pneumatic tests were analyzed by means of a graphical matching procedure using newly-developed pressure and pressure-derivative type-curves. Analyses of pressure data from individual monitoring intervals using these new type-curves, under the assumption that the rock acts as a uniform and isotropic fractured porous continuum, yield results that are comparable with parameters obtained from a numerical inverse procedure described in Illman et al. (1998). The results include information about pneumatic connections between the injection and monitoring intervals, corresponding directional air permeabilities, and air-filled porosities. Together with the results of earlier site investigations, single- and cross-hole test analyses reveal that at the Apache Leap Research Site in central Arizona: (1) the pneumatic pressure behavior of fractured tuff is amenable to analysis by methods that treat the rock as a continuum on scales ranging from meters to tens of meters; (2) this continuum is representative primarily, but not exclusively, of interconnected fractures; (3) its pneumatic properties vary strongly with location, direction and scale, in particular, the mean of pneumatic permeabilities increases, and their variance decreases with scale; (4) this scale effect is most probably due to the presence in the rock of various size fractures that are interconnected on a variety of scales; and (5) given a sufficiently large sample of spatially varying pneumatic rock properties on a given scale of measurement, these properties are amenable to analysis by geostatistical methods, which treat them as correlated random fields defined over a continuum.
31
McAuslane, James Alastair Neil. "Inulin and para-aminohippuric acid : determinants of glomerular filtration rate and renal blood flow following single intravenous bolus injection in man." Thesis, University of Edinburgh, 1990. http://hdl.handle.net/1842/24144.
Full text
32
Sohail, Aamir. "An experimental investigation of dual-injection strategies on diesel-methane dual-fuel low temperature combustion in a Single Cylinder Research Engine." Thesis, Mississippi State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1596101.
Full textAbstract:
<p> The present manuscript discusses the performance and emission benefits due to two diesel injections in diesel-ignited methane dual fuel Low Temperature Combustion (LTC). A Single Cylinder Research Engine (SCRE) adapted for diesel-ignited methane dual fuelling was operated at 1500 rev/min and 5 bar BMEP with 1.5 bar intake manifold pressure. The first injection was fixed at 310 CAD. A 2<sup>nd</sup> injection sweep timing was performed to determine the best 2<sup>nd</sup> injection timing (as 375 CAD) at a fixed Percentage Energy Substitution (PES 75%). The motivation to use a second late injection ATDC was to oxidize Unburnt Hydrocarbons (HC) generated from the dual fuel combustion of first injection. Finally, an injection pressure sweep (550-1300 bar) helped achieve simultaneous reduction of HC (56%) and CO (43%) emissions accompanied with increased IFCE (10%) and combustion efficiency (12%) w.r.t. the baseline single injection (at 310 CAD) of dual fuel LTC. </p>
33
Kuroda, Yutaka. "Treatment of experimental osteonecrosis of the hip in adult rabbits with a single local injection of recombinant human FGF-2 microspheres." Kyoto University, 2011. http://hdl.handle.net/2433/142084.
Full text
34
Jovanovic, N., N. Cvetojevic, C. Schwab, et al. "Efficiently feeding single-mode fiber photonic spectrographs with an extreme adaptive optics system: on-sky characterization and preliminary spectroscopy." SPIE-INT SOC OPTICAL ENGINEERING, 2016. http://hdl.handle.net/10150/622807.
Full textAbstract:
High-order wavefront correction is not only beneficial for high-contrast imaging, but also spectroscopy. The size of a spectrograph can be decoupled from the size of the telescope aperture by moving to the diffraction limit which has strong implications for ELT based instrument design. Here we present the construction and characterization of an extremely efficient single-mode fiber feed behind an extreme adaptive optics system (SCExAO). We show that this feed can indeed be utilized to great success by photonic-based spectrographs. We present metrics to quantify the system performance and some preliminary spectra delivered by the compact spectrograph.
35
Ramos, Vargas Pablo Francisco. "Evaluation de la sensibilité face aux SEE et méthodologie pour la prédiction de taux d’erreurs d’applications implémentées dans des processeurs Multi-cœur et Many-cœur." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT022/document.
Full textAbstract:
La présente thèse vise à évaluer la sensibilité statique et dynamique face aux SEE de trois dispositifs COTS différents. Le premier est le processeur multi-cœurs P2041 de Freescale fabriqué en technologie 45nm SOI qui met en œuvre ECC et la parité dans leurs mémoires cache. Le second est le processeur multifonction Kalray MPPA-256 fabriqué en technologie CMOS 28nm TSMC qui intègre 16 clusters de calcul chacun avec 16 cœurs, et met en œuvre ECC dans ses mémoires statiques et parité dans ses mémoires caches. Le troisième est le microprocesseur Adapteva E16G301 fabriqué en 65nm CMOS processus qui intègre 16 cœurs de processeur et ne pas mettre en œuvre des mécanismes de protection. L'évaluation a été réalisée par des expériences de rayonnement avec des neutrons de 14 Mev dans des accélérateurs de particules pour émuler un environnement de rayonnement agressif, et par injection de fautes dans des mémoires cache, des mémoires partagées ou des registres de processeur pour simuler les conséquences des SEU dans l'exécution du programme. Une analyse approfondie des erreurs observées a été effectuée pour identifier les vulnérabilités dans les mécanismes de protection. Des zones critiques telles que des Tag adresses et des registres à usage général ont été affectées pendant les expériences de rayonnement. De plus, l'approche Code Emulating Upset (CEU), développée au Laboratoire TIMA, a été étendue pour des processeurs multi-cœur et many-cœur pour prédire le taux d'erreur d'application en combinant les résultats issus des campagnes d'injection de fautes avec ceux issus des expériences de rayonnement<br>The present thesis aims at evaluating the SEE static and dynamic sensitivity of three different COTS multi-core and many-core processors. The first one is the Freescale P2041 multi-core processor manufactured in 45nm SOI technology which implements ECC and parity in their cache memories. The second one is the Kalray MPPA-256 many-core processor manufactured in 28nm TSMC CMOS technology which integrates 16 compute clusters each one with 16 processor cores, and implements ECC in its static memories and parity in its cache memories. The third one is the Adapteva Epiphany E16G301 microprocessor manufactured in 65nm CMOS process which integrates 16 processor cores and do not implement protection mechanisms. The evaluation was accomplished through radiation experiments with 14 Mev neutrons in particle accelerators to emulate a harsh radiation environment, and by fault injection in cache memories, shared memories or processor registers, to simulate the consequences of SEUs in the execution of the program. A deep analysis of the observed errors was carried out to identify vulnerabilities in the protection mechanisms. Critical zones such as address tag and general purpose registers were affected during the radiation experiments. In addition, The Code Emulating Upset (CEU) approach, developed at TIMA Laboratory was extended to multi-core and many core processors for predicting the application error rate by combining the results issued from fault injection campaigns with those coming from radiation experiments
36
Armour, Jeffrey Andrew. "Chronic effects of single intra-peritoneal injection of endosulfan on rainbow trout (Oncorhynchus mykiss) and field observations of caged rainbow in Oshawa Creek." Thesis, UOIT, 2009. http://hdl.handle.net/10155/30.
Full textAbstract:
The organochlorine pesticide endosulfan has been shown to be highly toxic to fish
and there is some evidence to support that it may act as an endocrine disrupting chemical.
Juvenile rainbow trout (Oncorhynchus mykiss) were caged at 4 sites in Oshawa Creek
during the fall and spring of 2008 and 2009 while another group was intra-peritoneal
injected in the laboratory with varying concentrations (ppm) of endosulfan. Plasma
vitellogenin (VTG) levels, liver ethoxyresorufin-O-deethylase (EROD), citrate synthase
(CS), lactate dehydrogenase (LDH), and brain acetylcholine esterase (AChE) (caged fish
only) enzymatic activities were measured. Trout injected with endosulfan experienced an
increase of the anaerobic (LDH activity) and a decrease of the aerobic (CS activity)
metabolic pathways, while male VTG levels increased. Since it was a singular injection,
VTG results have to be confirmed. Fall caged trout showed increased EROD activity and
inhibited AChE activity while those caged in the spring experienced an unexpected
exposure to the lampricide 3-Trifluoro-Methyl-4-Nitro-Phenol (TFM) which disrupted
metabolic parameters (inhibited CS and increased LDH activity). Both fall and spring
caged trout experienced no induction of VTG activity. Further research is needed since
the spring exposure was altered due to the unplanned TFM treatment and thus did not
represent a valid temporal replicate.
37
Johnson, Darrel E. "Estimating the Dynamic Sensitive Cross Section of an FPGA Design through Fault injection." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd803.pdf.
Full text
38
Christner, Sarah [Verfasser], and Ulrich [Akademischer Betreuer] Schraermeyer. "The effects of a single intravitreal injection of the VEGF-A-inhibitors aflibercept and ranibizumab on glomeruli of monkeys / Sarah Christner ; Betreuer: Ulrich Schraermeyer." Tübingen : Universitätsbibliothek Tübingen, 2017. http://d-nb.info/1199470090/34.
Full text
39
Seifart, Anja. "The impact of functional electrical stimulation to the lower leg after a single botulinum toxin injection in children with a spastic equinus gait due to cerebral palsy." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/2860.
Full textAbstract:
Thesis (MScPhysio (Physiotherapy))--Stellenbosch University, 2008.<br>Cerebral palsy (CP) is a common neurological condition seen in children which results in
childhood disability. Damage to the developing brain results in abnormal muscle tone and
decreased force generation, which leads to loss of independent function. Previous studies
investigating interventions targeting the typical equinus gait pattern seen in spastic CP
have reported inconclusive and widespread outcomes.
Objectives
The objectives of the study were to determine (1) the effect of functional electrical
stimulation (FES) after a single botulinum toxin injection into the triceps surae muscle as
a functional orthosis on various gait parameters and economy of movement; (2)
caregivers’ perceptions of the impact of the intervention on their child’s function and
participation, and (3) optimal timing intervals for introducing FES after a botulinum toxin
injection.
Method
Single-subject research with a multiple baseline approach was conducted on five
ambulant subjects (average age 5.1 years, SD=1.4) in the Cape Metropole with a dynamic
equinus gait due to hemiplegic CP. Two-dimensional gait analysis, isometric
dynamometry, Energy Expenditure Index (EEI), and a caregiver questionnaire were used
to gather data on walking speed, ankle angles at initial contact of gait, isometric plantarand
dorsiflexior muscle strength, energy expenditure during gait, as well as caregiver
perception on participation changes. Statistical analysis was conducted by means of
ANOVA tests and graphic data illustrations. Results
A statistically significant pre- to post intervention (FES after botulinum toxin) change
was found for plantarflexor muscle strength. This effect was partially maintained over the
withdrawal phase. Caregivers felt the intervention to have a positive influence on their
children’s walking speeds, as well as on age-appropriate function and participation. Selfselected
walking speed, dorsiflexor muscle strength, and ankle angles at initial contact
did not change significantly. A 32-day interval between between botulinum toxin and the
FES programme resulted in the most pronounced improvements in terms of walking
speed, EEI scores, and plantarflexor muscle strength.
Conclusion
FES to the lower limb, 32 days after botulinum toxin into the triceps surae, applied for 30
minutes per day, five times a week over a total of four weeks, seemed to improve selected
gait parameters as well as caregiver perception of impact on function and activities of
daily living. However, further research is needed.
40
Lee, Nigel. "Comparison of a single versus a four intradermal sterile water injection technique for the relief of lower back pain for women in labour: A mixed methods study." Thesis, Australian Catholic University, 2013. https://acuresearchbank.acu.edu.au/download/fb8991208095920185a907088b92dba49532b490c2fcc90be0531a679c1ed24c/5032178/LEE_NIGEL_2013.pdf.
Full textAbstract:
Significant back pain is often experienced by women in labour and may increase the need for pharmacological pain relief, often with associated side effects including excessive sedation and restriction to mobility. Sterile water injections (SWIs) are a simple, safe, effective, non-pharmacological technique for relieving back pain in labour; however, the number of injections required to achieve optimal analgesia is unknown. Furthermore, administration of SWI causes a brief, but intense, pain which may influence the acceptability of the procedure to labouring women. There is limited data from previous trials on how women view SWI, and the benefits of this particular analgesic option, versus the pain associated with administration. No previous studies have examined how midwives regard the prospect of causing pain to labouring women; albeit to relieve pain. The aim of this research was to determine if a single injection of sterile water was clinically similar to four injections in terms of degree of analgesia and to examine the experiences of labouring women and midwives receiving, and administering, SWIs...
41
Kiyohara, Yoshimoto. "A Novel Morphological Technique to Investigate a Single Climbing Fiber Synaptogenesis with a Purkinje Cell in the Developing Mouse Cerebellum : Dil Injection into the Inferior Cerebellar Peduncle." Kyoto University, 2003. http://hdl.handle.net/2433/148473.
Full text
42
Vaitl, Tobias [Verfasser], Stefan [Gutachter] Wohnlich, and Rolf [Gutachter] Bracke. "Single-well injection-withdrawal Tracerversuche zur Charakterisierung von geothermischen Reservoiren : Bestimmung von Sorptionseigenschaften auf der Labor- und Feldskala / Tobias Vaitl ; Gutachter: Stefan Wohnlich, Rolf Bracke ; Fakultät für Geowissenschaften." Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/1199614394/34.
Full text
43
Cannon, Matthew Joel. "Improving the Single Event Effect Response of Triple Modular Redundancy on SRAM FPGAs Through Placement and Routing." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7551.
Full textAbstract:
Triple modular redundancy (TMR) with repair is commonly used to improve the reliability of systems. TMR is often employed for circuits implemented on field programmable gate arrays (FPGAs) to mitigate the radiation effects of single event upsets (SEUs). This has proven to be an effective technique by improving a circuit's sensitive cross-section by up to 100x. However, testing has shown that the improvement offered by TMR is limited by upsets in single configuration bits that cause TMR to fail.This work proposes a variety of mitigation techniques that improve the effectiveness of TMR on FPGAs. These mitigation techniques can alter the circuit's netlist and how the circuit is placed and routed on the FPGA. TMR with repair showed a neutron cross-section improvement of 100x while the best mitigation technique proposed in this work showed an improvement of 700x.This work demonstrates both some causes behind single bit SEU failures for TMR circuits on FPGAs and mitigation techniques to address these failures. In addition to these findings, this work also shows that the majority of radiation failures in these circuits are caused by multiple cell upsets, laying the path for future work to further enhance the effectiveness of TMR on FPGAs.
44
Lawrence, Jacob David. "Design and development of a high pressure ED95 fuel delivery system for a single cylinder test cell engine." Thesis, KTH, Fordonsdynamik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-286351.
Full textAbstract:
Bio-fuels, being the primary alternative to the fossil fuels, used in the internal combustion engines are subjected to constant development. The development of alternative Ethanol Diesel (ED95) formulations at AVL Motortestcenter AB has demanded a test facility capable of evaluating the combustion quality of these specimens. A test cell capable of evaluating fuels operating on the compression ignition concept was required for this reason. The aim of this thesis is to develop a high pressure fuel delivery system for a single cylinder test cell engine. The literature review conducted offered knowledge on stages involved in the development of the fuel and the operation of high pressure fuel systems for engines operating on the Diesel concept. Knowledge was acquired on phenomenon such as pressure fluctuations and information regarding engine test cells was familiarised. Scania's XPI fuel system being the designated fuel system for the test cell was studied and adaptations required for its implementation in the single cylinder test cell was investigated. Based on the information acquired, recommendations for the set up of the high pressure fuel system for the single cylinder test cell engine are mentioned.<br>Förnyelsebara biobränslen är det primära alternativet till fossila bränslen för användning i interna förbränningsmotorer och är under ständig utveckling. För den fortsatta utvecklingen av etanoldiesel (ED95) genom provning av nya formuleringar vid AVL Motortestcenter AB krävs ett lämplig testupplägg. Förbränningskvalitetsutvärderingen kräver en avancerad testcell där bränslets förbränningsegenskaper kan utvärderas. Målet med detta arbete var att utveckla ett högtrycksbränslesystem lämpligt för en singelcylindrig forskningsmotor som arbetar enligt kompressionständningsprincipen (dieselprincipen). Litteraturstudien samlade kunskap om bränsleutveckling samt kunskap om dieselmotorers högtrycksbränslesystemen, dess uppbyggnad och utmaningar. Kunskap om fenomen som tryckoscillationer och kavitation i bränslesystem samt förståelse för motorprovcellers uppbyggnad införskaffades. Scanias XPI bränslesystem, som forskningsmotorns högtrycks- bränslesystem ska efterlikna, studerades och adaptioner för att passa till encylinderkörningar i provcell utvärderades. Baserat på informationen ges rekommendationer på hur Scanias XPI system kan implementeras och justeras för att fungera i AVL’s singelcylinderprovcell.
45
Matana, luza Lucas. "Étude des effets induits par la radiation spatial et atmosphérique sur des mémoires électroniques." Electronic Thesis or Diss., Montpellier, 2021. http://www.theses.fr/2021MONTS100.
Full textAbstract:
Le rayonnement est défini comme l'émission ou la transmission d'énergie sous forme d'ondes ou de particules, qui peuvent être ionisantes ou non ionisantes. L'interaction entre le rayonnement et la matière peut générer différentes réactions, qui peuvent varier en fonction des propriétés de la particule (type, énergie cinétique, masse et charge) et de la matière ciblée (semi-conducteurs dans le cadre de cette thèse). L'exposition de composants électroniques à des environnements avec une présence significative de rayonnement peut conduire à ce type d'interaction et, par conséquent, à une variété d'effets qui peuvent affecter considérablement la fiabilité des systèmes électroniques.Lors de la conception de dispositifs et de systèmes électroniques, la prise en compte des effets des rayonnements est fondamentale pour les applications dans des environnements hostiles. Par exemple, dans les systèmes avioniques et spatiaux, ces effets sont largement étudiés pour garantir la haute fiabilité des composants et fournir les informations nécessaires pour les décisions de conception. Les préoccupations liées aux rayonnements ont commencé à être prises en compte au début de l'ère spatiale.Les rayonnements ionisants peuvent induire des effets dans différents dispositifs, et plusieurs travaux ont montré que les mémoires électroniques sont l'une des principales causes d’erreur dans les systèmes. De plus, en raison de leur nature, les mémoires ont la capacité intrinsèque de stocker la trace des fautes induites par les rayonnements, comme le Single-Bit Upset (SBU), ce qui fait de ces dispositifs le meilleur candidat pour étudier les événements singuliers.Le premier sujet introduit par la thèse est une étude sur les effets induits par les ions lourds sur une mémoire Flash de type NAND. Cette étude est basée sur plusieurs campagnes d'irradiation avec une large gamme d'énergies. Les résultats ont révélé différents mécanismes de défaillance, notamment des SBUs, des petits groupes d'erreurs, des fautes dans le registre et des fautes affectant une ou plusieurs colonnes de la mémoire. La section efficace a été calculée pour chaque type de faute, et leurs causes ont été discutées.Ensuite, une étude sur les effets de la radiation neutronique (spectres thermiques et atmosphériques) sur une DRAM auto-rafraîchissante est présentée. Des méthodes de test statique et dynamique ont été utilisées pour définir la réponse du dispositif sous faisceau neutronique. Dans ce manuscrit, les résultats expérimentaux de deux campagnes de tests sont présentés, avec l'identification de différents modèles de faute, comme les SBUs, bits collés et blocs d’erreurs. Ces fautes ont été étudiées et caractérisées avec le calcule de la section efficace, du taux d'erreurs et l’étude des bitmaps. Une analyse du temps de rétention des cellules affectées a été réalisée, montrant une différence d’efficacité entre le mécanisme d'autorafraîchissement et une véritable opération de lecture. De plus, une corrélation du mécanisme de défaillance qui génère à la fois des SBUs et des bits collés est également proposée. Finalement, les effets de réparation du recuit à haute température ont été étudiés dans des tests post irradiation.Après, ce manuscrit présente aussi une étude comparative sur les effets induits par les neutrons sur les SDRAM produites avec trois nœuds technologiques différents. Les résultats ont révélé la présence de SBUs et de bits collés dans les mémoires, montrant une sensibilité plus élevée pour la génération la plus ancienne et des résultats similaires pour les deux autres modèles étudiés.Enfin, une procédure est présentée afin d’évaluer la fiabilité des applications basées sur réseau de neurones convolutifs (CNN). Dans cette optique, cette étude propose d'utiliser des modèles de défauts réalistes extraits des tests de rayonnement comme entrée pour un émulateur logiciel qui effectue l'injection de défauts dans le système informatique dans lequel le CNN est implémenté<br>Radiation is defined as the emission or transmission of energy as waves or particles, which can be either ionizing or non-ionizing. The interaction between the radiation and the matter can generate different reactions, which may vary depending on the properties of the particle (type, kinetic energy, mass, and charge), and the target (semiconductors in this thesis scope). The exposition of electronics components to environments with a significant presence of radiation may lead to this kind of interaction and, consequently, to a variety of effects that can drastically affect the reliability of electronic systems.When designing electronic devices and systems, considering radiation effects is fundamental for applications in harsh environments. For instance, in avionics and space systems, these effects are extensively studied to ensure the high reliability of the components and provide the needed insight for design decisions. The concerns related to radiation started to be noted at the beginning of the space era.Ionizing radiation may induce effects in different types of devices, and many works have shown that memories are one of the highest contributors to soft errors in systems. Furthermore, due to their nature, memories have the intrinsic capability of storing radiation-induced fault tracks, e.g., Single-Bit Upsets (SBUs), making these devices the best candidate for studying soft errors.The first topic introduced by the thesis is a study on the heavy-ion induced effects on a Single-Level Cell NAND Flash. This study is based on several irradiation test campaigns with a wide range of heavy-ions energies. The results revealed different failure mechanisms, including Single-Event Upsets, small clusters of errors, data register upsets, and a column-wise failure mode. Cross section was calculated for each of these failure modes, and their causes were discussed.Then, a study on the effects of neutron irradiation (thermal and atmospheric-like spectra) on a self-refresh DRAM is presented. Static and dynamic test methods were used to define the response of the device under irradiation. In this manuscript, experimental results from two different test campaigns are presented, with the identification of SBUs, stuck bits, and block errors. These faults were investigated and characterized by event cross section, soft-error rates, and bitmaps evaluations. An analysis of the damaged cells' retention time was performed, showing a difference between the self-refresh mechanism and a read operation. Additionally, a correlation of the fault mechanism that generates both SBUs and stuck bits under neutron irradiation is also proposed. Furthermore, high-temperature annealing was studied in post-radiation tests.Following, this thesis presents a comparative study on the neutron-induced effects on SDRAMs produced with three different technology nodes. The results revealed the occurrence of SBUs and stuck-bits in the memories, showing higher sensitivity for the oldest generation and similar results for the other two models.Finally, a framework is presented to assess the reliability of Convolutional Neural Network (CNN) applications. In this light, this study proposes using realistic fault models retrieved from radiation tests as input for a software emulator that performs fault injection in the computing system in which the CNN is implemented
46
Batagin, Armelin Fábio. "Stratégie d'estimation de la vulnérabilité aux erreurs `soft' basée sur la susceptibilité aux événements transitoires de chaque porte logique." Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLT035.
Full textAbstract:
La vulnérabilité aux erreurs récupérables (SEV - Soft Error Vulnerability) est un paramètre estimé qui, associé aux caractéristiques de l’environnement de rayonnement, permet d’obtenir le SER (Soft-Error Rate), une métrique couramment utilisée pour prédire le comportement des systèmes électroniques numériques exposés au rayonnement de particules. Actuellement, la méthode la plus précise pour l’estimation de SER est le test de rayonnement, car elle présente l’interaction réelle des particules avec le dispositif électronique. Cependant, ce test est coûteux et requiert le circuit qui, lui, n’est disponible qu’à la fin du cycle de développement. Cela a motivé le développement d'autres méthodes d'estimation de SER et de SEV, notamment des méthodes analytiques, des simulations électriques et logiques, ainsi que des approches basées sur l'émulation. Ces techniques incorporent généralement des effets de masquage logique, électrique ou temporel. Néanmoins, la plupart de ces techniques ne prennent pas en compte la susceptibilité aux événements singuliers transitoires (SET - Single Event Transient). Ce facteur est intrinsèque au test de radiation et représente la probabilité que le rayonnement ionisant produise une erreur `soft' à la sortie des portes logiques du circuit. Dans ce contexte, cette thèse propose une stratégie d’estimation de SEV basée sur les susceptibilités aux SET. Deux versions de cette stratégie sont considérées : la version simplifiée, où les susceptibilités SET prennent en compte seulement les effets de la topologie des portes logiques et la version complète, où les susceptibilités prennent en compte la topologie et le fonctionnement du circuit. La stratégie proposée a été évaluée avec une approche basée sur la simulation, estimant la SEV de 38 circuits de référence. Les résultats montrent que les deux versions de la stratégie entraînent une amélioration de la précision de l'estimation, la version complète présentant l'erreur d'estimation la plus faible. Enfin, la faisabilité de l’adoption de la stratégie proposée est démontrée avec approche basée sur l’émulation<br>The Soft-Error Vulnerability (SEV) is an estimated parameter that, in conjunction with the characteristics of the radiation environment, is used to obtain the Soft-Error Rate (SER), that is a metric used to predict how digital systems will behave in this environment. Currently, the most confident method for SER estimation is the radiation test, since it has the actual interaction of the radiation with the electronic device. However, this test is expensive and requires the real device, that becomes available late on the design cycle. These restrictions motivated the development of other SER and SEV estimation methods, including analytical, electrical and logic simulations, and emulation-based approaches. These techniques usually incorporate the logical, electrical and latching-window masking effects into the estimation process. Nevertheless, most of them do not take into account a factor that is intrinsic to the radiation test: the probability of the radiation particle to produce a Soft-Error (SE) at the output of the gates of the circuit, referred to as Single-Event Transient (SET) susceptibility. In this context, we propose a strategy for SEV estimation based on these SET susceptibilities, suitable for simulation- and emulation-based frameworks. In a simplified version of this strategy, the SET susceptibilities take into account only the effects of the gate topology, while in a complete version, these susceptibilities consider both the topology and the operation of the circuit, that affects its input pattern distribution. The proposed strategy was evaluated with a simulation-based framework, estimating the SEV of 38 benchmark circuits. The results show that both versions of the strategy lead to an improvement in the estimation accuracy, with the complete version presenting the lowest estimation error. Finally, we show the feasibility of adopting the proposed strategy with an emulation-based framework
47
Craig, Douglas William. "Effect of vortex circulation on injectant from a single film-cooling hole and a row of film-cooling holes in a turbulent boundary layer: part 1: injection beneath the vortex downwash." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/27010.
Full text
48
Michailidis, Antonis D. "Understanding complex CI-combustion strategies : an experimental investigation." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/10957.
Full textAbstract:
Within this body of work several series of experiments will investigate the nature of complex combustion in an experimental single-cylinder engine emulating a modern passenger car size compression-ignition (CI) engine. Regimes of single, piloted single and piloted split-main injections will be tested and compared in terms of combustion characteristics, specific emission output and cyclic behaviour to determine how increased injection complexity affects the emissions and output of the modern CI engine. Through these tests, the effect of fuel-line stationary waves will be demonstrated and investigated, showing conclusively that optimised engine calibration is essential to account for injector-generated waves in any multiple injection scenario. This data will then be confirmed with a dedicated analysis using an injector rate measuring tube. The tests will then be expanded to include examination into the behaviour of injector needle-lift standard deviation over its operating cycle, in-cylinder pressure standard deviation behaviour and trends over the combustion cycle as well as IMEP variability. Through these tests a novel method to detect start of combustion will be proposed and compared to conventional methods. Low temperature combustion (LTC) will be tested under incremental injection complexity. Tests will be optimised for combustion phasing and injection pressure, with a view to analysis of emissions, output and cyclic behaviour to establish whether the knowledge gained about conventional combustion holds true under LTC. Optimization of engine parameters will be shown to result in easier to implement LTC regimes with superior emissions characteristics. Finally, LTC tests will be expanded to include 30% and 50% by volume gas-to-liquid fuel (GTL) blends in order to determine whether fuel characteristics further influence emissions, output and cyclic behaviour in LTC through complex injection regimes. How GTL-blend ratio affects trends in emissions and cyclic behaviour will also be examined and compared to conventional diesel fuel.
49
CHIVATA, Nilson Yecid Bautista. "Simulação numérica da equação de advecção-dispersão-reação para um traçador em meios porosos heterogêneos e anisotrópicos por um método de volumes finitos, utilizando malhas poligonais." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/19634.
Full textAbstract:
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-14T12:28:59Z
No. of bitstreams: 2
license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5)
Dissertacao Bautista Nilson.pdf: 11338318 bytes, checksum: ae22c70eb1719f066a5eeb3de436c953 (MD5)<br>Made available in DSpace on 2017-07-14T12:28:59Z (GMT). No. of bitstreams: 2
license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5)
Dissertacao Bautista Nilson.pdf: 11338318 bytes, checksum: ae22c70eb1719f066a5eeb3de436c953 (MD5)
Previous issue date: 2016-01-26<br>CNPQ<br>A modelagem e a simulação numérica do transporte de solutos, como por exemplo traçadores, em meios porosos heterogêneos e anisotrópicos, tais como aquíferos e reservatórios de petróleo constituem-se num grande desafio de natureza matemática e numérica. A modelagem de falhas selantes, canais, poços inclinados, pinchouts e outras características complexas demanda o uso de malhas não-estruturadas e não-ortogonais, capazes de se adaptar naturalmente ao domínio em estudo. Os pacotes computacionais utilizados comumente na indústria do petróleo, na sua grande maioria, se baseiam no Método das Diferenças Finitas com Aproximação de Fluxo por Dois Pontos (Two-Point Flux Approximation - TPFA) e no Método de Ponderação à Montante de Primeira Ordem (First Order Upwind Method - FOU), devido a sua facilidade de implementação e sua eficiência computacional. Infelizmente, os métodos TPFA são incapazes de produzir soluções convergentes em malhas não-ortogonais ou para tensores de dispersão ou permeabilidades completos e os métodos FOU produzem soluções com difusão numérica excessiva, exigindo malhas demasiadamente refinadas para obtermos soluções confiáveis. Uma alternativa ao TPFA, e que permite o uso de tensores completos e malhas não-ortogonais, é o Método dos Elementos Finitos de Galerkin (MEF), porém este método não produz soluções localmente conservativas, o que pode ser um problema sério para a modelagem de problemas envolvendo leis de conservação, como no escoamento em meios porosos. Outra alternativa são os Métodos de Volumes Finitos (MVF). Nas suas variantes mais robustas, estes métodos são capazes de lidar com malhas poligonais quaisquer e tensores de dispersão e permeabilidades completos e com razão de anisotropia arbitrária, além de produzir aproximações discretas de alta ordem e localmente conservativas. Neste contexto, no presente trabalho, apresentamos uma formulação MVF centrado na célula para a modelagem do transporte de um traçador não-reativo num escoamento monofásico em meios porosos heterogêneos e anisotrópicos. Para a discretização dos termos elípticos, tanto da equação de pressão quanto da equação de Advecção-Dispersão-Reação (ADRE), utilizou-se um MVF com aproximação de fluxo por múltiplos pontos que faz uso do estêncil diamante (MPFA-D) e para a discretização dos termos hiperbólicos, usamos o método FOU e um MVF do tipo MUSCL (Monotone Upstream Centered Scheme for Conservation Laws). A fim de testar nossa formulação, resolvemos alguns problemas benchmark encontrados na literatura.<br>Modeling and numerical simulation of solutes (e.g. Tracers) in heterogeneous and anisotropic
porous media such as aquifers and oil reservoirs, constitute a bigger challenge of
mathematics and numerical nature. Modeling sealants faults, channels, inclined wells,
pinch outs and other complex features of these geological formations demand the use of
unstructured and not orthogonal meshes, able to adapt naturally to the domain under
study. The computational packages used commonly in the oil industry, mostly, are based
on the Finite Difference Method with Two Point Flow Approximation (TPFA) and the
Amount First Order Upwind method (FOU), due to its ease of implementation and its
computational efficiency. Unfortunately, TPFA methods are unable to produce conver-gent
solutions in non-orthogonal meshes or in permeability or dispersion full Tensor and FOU
methods produce solutions with excessive numerical diffusion, requiring excessively refined
mesh to obtain reliable solutions. An interesting alternative to TPFA, which allows the use
of full tensor and not orthogonal meshes, is the Galerkin Finite Element Method (FEM),
but this method does not produce solutions locally conservative, which can be a serious
problem for modeling problems involving conservation laws as the flow in porous media.
An interesting alternative is the Finite Volume Methods (MVF). In its most robust
embodiments, these methods are able to cope with any polygonal mesh and full
permeability or dispersion tensors and with an arbitrary anisotropy ratio, beyond
producing discrete approximations of high order and locally conservative. In this context,
the present study, we present one MVF formulation cell centered to modeling the transport
of a non-reactive tracer in single-phase flow in heterogeneous and anisotropic porous
media. For the elliptical discretization terms, both, the pressure equation as the equation
advection-dispersion-reaction (ADRE), we used The FVMF multipoint flow approximation
that uses the diamond stencil (MPPA-D) and for the discretization of hyperbolic
terms, we use the FOU method and an MVF type MUSCL (Monotone Upstream Centered
Scheme for Conservation Laws). In order to test our formulation, we solve some
benchmark problems in the literature.
50
Nguyen, Tam Khanh Tu. "Evaluation of Active Capacitor Banks for Floating H-bridge Power Modules." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/104466.
Full textAbstract:
The DC-side floating capacitors in the floating power modules of power converters are
subject to high voltage fluctuation, due to the presence of reactive harmonic components.
Utilizing passive capacitors, as done in traditional methods, helps reduce the DC-bus voltage
ripple but makes the system bulky. An active capacitor can be integrated with the floating
H-bridge power modules to remove the effect of the ripple powers on the DC bus. The
auxiliary circuit, which is much smaller in size compared to an equivalent passive capacitor,
helps increase the power density of the system. This work focuses on the analysis of power
components, and the extension of the active capacitor to the Perturbation Injection Unit
(PIU), in which the DC side is highly distorted by multiple harmonic components. A control
scheme is proposed to compensate for these multiple harmonics and balance the DC-link
voltage in the active capacitor. Also, an equivalent DC-bus impedance model is introduced,
which is more accurate than that in existing works. Simulation studies and evaluation of the
design have verified the effectiveness of the active capacitor solution.<br>Single-phase power converters have been widely used in many applications such as electric
vehicles, photovoltaic (PV) systems, and grid integration. Due to their popular application,
there is a need to reduce the sizes and volumes while still maintaining good performances of
the systems.
One of the most effective methods, which is a subject in many research works, is to replace
the bulky passive capacitor bank in a system by an active capacitor. The active capacitor
is designed to absorb the ripple components in the DC side of the converters, which results
in a constant DC-link voltage. In comparison to the passive capacitor solution, the active
capacitor is much smaller in size but can give a better DC-bus ripple performance. Therefore,
the active capacitor has become an attractive solution for the single-phase converters.
The active capacitor for the traditional rectifier, where the DC side is directly connected
to a load, has been intensively investigated in the past decade. However, there is limited
research regarding the active capacitor for rectifiers with floating H-bridge power modules.
This work extends the application of the active capacitor to the Perturbation Injection
Unit (PIU), which is a grid-connected single-phase rectifier with floating H-bridge power
modules. The selection of a suitable active capacitor for the PIU is based on the evaluation
of various active capacitor banks. Limits in existing control schemes, which prevent the extension
of the active capacitor to the PIU, are thoroughly studied. An effective voltage-mode
control scheme is then proposed for the selected active capacitor, which makes it an attractive
solution for the PIU. Moreover, limits of the DC-bus impedance analysis using traditional
assumptions in existing works are investigated, and an improved DC-bus impedance model is
proposed. Based on the operation conditions of the PIU and the proposed impedance model,
the active capacitor's components can be properly designed, and improved configurations in
terms of the equivalent impedance can be analyzed. Simulation results, as well as the design
and evaluation of the active capacitor, demonstrate great improvements in terms of volume
and weight over the traditional passive capacitor bank.