Dissertations / Theses on the topic 'Charge and time measurement'
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Swaminathan, Prasanna V. "Measurement of Charge Storage Decay Time and Resistivity of Spacecraft Insulators." DigitalCommons@USU, 2004. https://digitalcommons.usu.edu/etd/2094.
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Insulators used in the construction of spacecraft are irradiated with high-energy electrons in the space environment and this sometimes causes the insulators to charge to very high voltages. Such charged insulators can generate spontaneous electric partial-discharge pulses of the order of mA to tens of A. These pulses sometimes last enough time to destroy the expensive micro-circuitry present in the spacecraft. In evaluating the threat to the spacecraft due to these discharges, calculation of the resistivity becomes a critical parameter since it determines how accumulated charge will distribute across the spacecraft and how rapidly charge imbalance will dissipate. So far, resistivity values for the insulators for spacecraft applications have been simply imported from tabulated results measured using standard American Society for Testing and Materials (ASTM) and International Electro-technical Commission (IEC) methods. This thesis work provides the details of the charge storage method which has been found to be more appropriate in calculating the resistivity of spacecraft insulators by emulating the space environment better. This method is based on the concept that the resistivity is better measured as the decay of the charge deposited on the surface of an insulator, rather than by the flow of current across two electrodes around the sample which is the case with the classical method of measurements.
From the results obtained from the charge storage method, it has been found that the ASTM resistivity values for thin film insulating spacecraft materials have been found to under-predict charge transport values applicable to many spacecraft charging problems, by 10 to 104 times. The charge storage method has only one side of the insulator in vacuum exposed to charged particles, light and plasma, with a metal electrode attached to the other side of the insulator. The chamber for measuring the charge storage decay has been designed with the capability to measure 32 samples simultaneously. The details of the apparatus, instrumentation, test methods, data acquisition methods, and data analysis for measuring resistivity of the spacecraft insulators are given here. Details about the vacuum environment, sample mounting, isolation of the samples, charging of the samples, measurement of the surface charge, rotary motion of the sample carousel, etc., are also given. The report also includes differences between the classical methods and the charge storage method both in terms instrumentation and methodology. The results obtained from both methods are tabulated showing the superiority of the charge storage method. Recommendations for future work are also included.
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Kulon, Janusz. "Real-time measurement of bipolar charge distribution on pharmaceutical aerosols and powders using phase doppler anemometry and a bipolar charge measurement system." Thesis, Brunel University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488733.
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Maksimović, Petar 1968. "Observation of [pi]-B meson charge-flavor correlations and measurement of time dependent B⁰⁰ mixing in pp collisions." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47407.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1998.On t.p. "[pi]" appears as the lower case Greek letter, and the second "B" and "p" are each surmounted by a stroke.
Includes bibliographical references (p. 238-243).
by Petar Maksimović.
Ph.D.
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Collie, Rebecca J. "Understanding teacher well-being and motivation : measurement, theory, and change over time." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46025.
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Teacher well-being and motivation play important roles in teacher and student experiences at school. When teachers are faring well and feeling motivated to teach, they are more effective in their teaching, leave the profession less often, and promote motivation and achievement among their students. In this dissertation, three studies that investigated teacher well-being and motivation were conducted with the aim of advancing our understanding of the two constructs, as well as how they can be promoted among teachers. Study 1 involved conceptualising, developing, and testing the Teacher Well-Being Scale, which measures three factors of teacher well-being: workload well-being, organisational well-being, and student interaction well-being. Among a sample of 603 practicing teachers, results revealed that the new measure functioned similarly across the different demographic groups in the sample and that the three factors of well-being related as expected with other constructs (stress, job satisfaction, and flourishing). Study 2 involved elaborating and testing an explanatory model of teacher well-being, motivation, job satisfaction, and affective organisational commitment that was based in self-determination theory (Deci & Ryan, 1985, 2002). Using the same sample as Study 1, structural equation modelling provided support for the model’s main relationships. In addition, there were some unexpected findings that provide directions for future research (e.g., a double-sided view of autonomy revealing that it can be associated with positive and negative types of motivation). Study 3 involved examining growth curve models of change in teacher well-being and self-efficacy for teaching over two to three months. Among a sample of 71 practicing teachers, the findings showed that teacher well-being was stable over time, whereas self-efficacy for classroom management increased (the other two types of self-efficacy that were examined, self-efficacy for student engagement and instructional strategies, did not change over time). Findings also revealed the significance of the basic psychological needs (autonomy, competence, and relatedness) in predicting teacher well-being and self-efficacy. Taken together, the three studies help to improve our understanding of the highly important variables of teacher well-being and motivation. Implications of the findings for both research and practice are discussed.
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Ponthiere, Gregory Edouard Francois Michel. "Essays on the measurement of changes in lifetime welfare over time." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614339.
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Aytac, Yigit. "Time-resolved measurements of charge carrier dynamics in Mwir to Lwir InAs/InAsSb superlattices." Diss., University of Iowa, 2016. https://ir.uiowa.edu/etd/2039.
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All-optical time-resolved measurement techniques provide a powerful tool for investigating critical parameters that determine the performance of infrared photodetector and emitter semiconductor materials. Narrow-bandgap InAs/GaSb type-II superlattices (T2SLs) have shown great promise as next generation materials, due to superior intrinsic properties and versatility. Unfortunately, InAs/GaSb T2SLs are plagued by parasitic Shockley-Read-Hall recombination centers that shorten the carrier lifetime and limit device performance. Ultrafast pump-probe techniques and time-resolved differential-transmission measurements are used here to demonstrate that "Ga-free" InAs/InAs₁₋xSbx T2SLs and InAsSb alloys do not have this same limitation and thus have significantly longer carrier lifetimes. Measurements of unintentionally doped MWIR and LWIR InAs/InAs₁₋xSbx T2SLs demonstrate minority carrier (MC) lifetimes of 18.4 µs and 4.5 µs at 77 K, respectively. This represents a more than two order of magnitude increase compared to the 90 ns MC lifetime measured in a comparable MWIR and LWIR InAs/GaSb T2SL. Through temperature-dependent differential-transmission measurements, the various carrier recombination processes are differentiated and the dominant recombination mechanisms identified for InAs/InAs₁₋xSbx T2SLs. These results demonstrate that these Ga-free materials are viable options over InAs/GaSb T2SLs and potentially bulk Hg₁₋xCdxTe photodetectors.
In addition to carrier lifetimes, the drift and diusion of excited charge carriers through the superlattice layers (i.e. in-plane transport) directly aects the performance of photo-detectors and emitters. All-optical ultrafast techniques were successfully used for a direct measure of in-plane diffusion coeffcients in MWIR InAs/InAsSb T2SLs using a photo-generated transient grating technique at various temperatures. Ambipolar diffusion coefficients of approximately 60 cm²/s were reported for MWIR InAs/InAs₁₋xSbxT2SLs at 293 K.
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Olson, Benjamin Varberg. "Time-resolved measurements of charge carrier dynamics and optical nonlinearities in narrow-bandgap semiconductors." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/2596.
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All-optical time-resolved measurement techniques provide a powerful tool for investigating critical parameters that determine the performance of infrared photodetector and emitter semiconductor materials. Narrow-bandgap InAs/GaSb type-II superlattices (T2SLs) have shown great promise as a next generation source of these materials, due to superior intrinsic properties and versatility. Unfortunately, InAs/GaSb T2SLs are plagued by parasitic Shockley-Read-Hall recombination centers that shorten the carrier lifetime and limit device performance. Ultrafast pump-probe techniques and time-resolved differential transmission measurements are used here to demonstrate that Ga-free InAs/InAsSb T2SLs and InAsSb alloys do not have this same limitation and thus have significantly longer carrier lifetimes. Measurements at 77 K provided minority carrier lifetimes of 9 μs and 3 μs for an unintentionally doped mid-wave infrared (MWIR) InAs/InAsSb T2SL and InAsSb alloy, respectively; a two order of magnitude increase compared to the 90 ns minority carrier lifetime measured in a comparable MWIR InAs/GaSb T2SL. Through temperature-dependent lifetime measurements, the various carrier recombination processes are differentiated and the dominant mechanisms identified for each material. These results demonstrate that these Ga-free materials are viable options over InAs/GaSb T2SLs for potentially improved infrared photodetectors.
In addition to carrier lifetimes, the drift and diffusion of excited charge carriers through the superlattice growth layers (i.e. vertical transport) directly affects the performance of photodetectors and emitters. Unfortunately, there is a lack of information pertaining to vertical transport, primarily due to difficulties in making measurements on thin growth layers and the need for non-standard measurement techniques. However, all-optical ultrafast techniques are successfully used here to directly measure vertical diffusion in MWIR InAs/GaSb T2SLs. By optically generating excess carriers near one end of a MWIR T2SL and measuring the transit time to a thin, 2 lower-bandgap superlattice placed at the other end, the time-of-flight of vertically diffusing carriers is determined. Through investigation of both unintentionally doped and p-type superlattices at 77 K, the vertical hole and electron diffusion coefficients are determined to be 0.04±0.03 cm2/s and 4.7±0.5 cm2/s, corresponding to vertical mobilities of 6±5 cm2/Vs and 700±80 cm2/Vs, respectively. These measurements are, to my knowledge, the first direct measurements of vertical transport properties in narrow-bandgap superlattices.
Lastly, the widely tunable two-color ultrafast laser system used in this research allowed for the investigation of nonlinear optical properties in narrow-bandgap semiconductors. Time-resolved measurements taken at 77 K of the nondegenerate two-photon absorption spectrum of bulk n-type GaSb have provided new information about the nonresonant change in absorption and two-photon absorption coefficients in this material. Furthermore, as the nondegenerate spectrum was measured over a wide range of optical frequencies, a Kramers-Kronig transformation allowed the dispersion of the nondegenerate nonlinear refractive index to be calculated.
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Pereira, Manuel Bernardo Videira Coutinho Rodrigues. "Effects of fiscal policy: measurement issues and structural change." Doctoral thesis, Instituto Superior de Economia e Gestão, 2011. http://hdl.handle.net/10400.5/3431.
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Doutoramento em EconomiaConsiderable uncertainty surrounds the macroeconomic effects of fiscal policy. The re-search presented in this dissertation firstly aims at improving on the methods used to measure such effects - which feature vector autoregressions (VARs) as the basic tool. The investigation is partly carried out using structural VARs. The methodological innova¬tions in that part concern the joint identification of fiscal shocks vis-a-vis monetary policy shocks and the estimation of a model with time-varying parameters using a non-recursive identification scheme. I also use reduced-form VARs to assess the effects of a novel shock measure, derived from budget forecasts, that is arguably free of anticipatory movements. The second aim of the dissertation is to present empirical results for the US, focusing on the way the impacts of the government budget on the economy have changed over time. The thesis is divided into three essays. In the first one, I present evidence that taxes and transfers were the most important force attenuating the severity of recessions up to the eighties, surpassing the role of monetary policy. Fiscal policy has, however, become less effective in stimulating output in the course of the last decades. The findings in the second and the third essays corroborate this conclusion. Such a change in effectiveness is particularly marked for the shock measure that is relatively unaffected by anticipation, which features multipliers with non-conventional signs in the recent period. In general, these findings call for more research on the factors that intervene in the transmission mechanism of fiscal policy and can bring about important variation in its impacts.
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GALIMBERTI, GIANLUCA. "TIME RESOLVED OPTICAL MEASUREMENTS ON DIFFERENT CARBON NANOTUBES ARCHITECTURES." Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/168735.
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Multi Wall Carbon Nanotubes (MWCNT) and Single Wall Carbon Nanotubes (SWCNT) can be grown in several architectures. A crucial aim is the theoretical and experimental study of the fundamental dynamics of photo-excited charge carriers into these ensembles. In fact the understanding of the charge transfer dynamics and of the exciton interaction is of great importance to improve the efficiency of the Carbon Nanotubes (CNT) based applications, as sensor, bio-medical, energy storage and photovoltaic technologies.
In this thesis, performing time resolved optical measurements with several experimental techniques, we analyze the fundamental dynamics in different CNT architectures. Charge transfer mechanisms from semiconductor to metallic are evidenced in unaligned SWCNT, whereas this process is not present in the vertically aligned. The excitonic behavior, revealed in all ensembles, are an interesting novelty in aligned MWCNT. The study of this behavior allows to addressed a long debated question about the graphite-like or SWCNT-like behavior of MWCNT, unveiling that the MWCNT electronic structure under 3 eV presents structured peaks like the Van Hove Singularities in SWCNT.
Non-linear excitonic effects are analyzed and, controlling the light polarization direction with respect to the CNT long-axis, we are able to select and unveil, in MWCNT architectures, different optical responses, evidencing linear and non-linear effects. In particular exciton-exciton annihilation and Multiple Exciton Generation (MEG) non-linear processes are discussed. The initial studies on a possible presence of MEG in MWCNT can pave the way to disentangle the complex processes occurring in the photo-excited MWCNT in the violet light region. The possibility to control the effects as a multiple generation of excitons represent crucial challenges in order to improve the photovoltaic performances of MWCNT based devices.
This thesis represents the initial step of a wide project whose ultimate goal is to improve the efficiency of photovoltaic devices based on SWCNT or MWCNT. In order to address this aim, heterogeneous systems are considered, in which different CNT architectures are combined with nanoparticles or organic groups. Starting from the basic systems and adding in subsequent stages the different components up to the complete devices, for each step the optical response will be studied.
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Hart, Raymond C. Jr. "A FRAMEWORK FOR PSYCHOMETRIC ANALYSIS OF STUDENT PERFORMANCE ACROSS TIME: AN ILLUSTRATION WITH NATIONAL EDUCATIONAL LONGITUDINAL STUDY DATA." Kent State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=kent1177960052.
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Spiteri, Tania. "Measurement of performance and kinetics during a change of direction, offensive and defensive agility task : a comparison of male and female athletes." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2012. https://ro.ecu.edu.au/theses/476.
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Study 1: Evaluation of a new lower body reaction time test. The purpose of this study was to investigate the reliability of two lower body reaction time (RT) tests to determine differences in RT between genders and compatible and incompatible conditions. Fifteen male and female (n=30) (22.63 ± 2.88 yrs; 175.31 ± 8.72 cm; 67.33 ± 9.71 kg) sport science students participated in this study. Subjects were required to complete two lower body RT tests responding to an arrow during compatible (same direction) and incompatible (opposite direction) stimulus-response conditions. The “simple” foot RT test, required subjects to step quickly on the appropriate mat, as directed by the stimulus, with response time being measured. The “complex” foot RT test required subjects to leap off a force plate to the appropriate mat in response to the stimulus, with RT, movement time (MT) and total movement time (TMT), being measured. Intra-class coefficient, coefficient of variation, and paired samples t-test (p ≤ 0.05) were calculated for all variables. High reliability was observed for both tests between compatible and incompatible conditions. Significant differences (p ≤ 0.05) were observed between genders for RT during the “simple” RT test. Significant differences (p≤ 0.05) were observed for MT and TMT during compatible and incompatible conditions for the “complex” RT test. In conclusion, both tests are reliable to determine lower body RT during both conditions. MT and TMT during the “complex” RT test were significantly different suggesting MT could be the discriminating factor between conditions as well as genders. Examining lower body RT during a movement commonly observed in sport may provide coaches more detail about athletes cognitive and athletic ability, enabling the components of RT to be trained.
Study 2: Human stimulus reliability during an offensive and defensive agility protocol. Athletes are required to change direction in response to opposition movements during offensive and defensive orientations throughout the duration of a game. Currently, humans have been used as a stimulus during agility protocols performing movements for athletes to respond to. However, the reliability of these movements and athlete running times during offensive and defensive condition has yet to be examined. Therefore, the purpose of this study was to assess the reliability of athlete running times and movements performed by a human stimulus during offensive and defensive agility protocols. One human stimulus was tested across two sessions completing 200 movement patterns, with five athletes performing agility trials responding to the human stimulus during both offensive and defensive conditions. All variables analyzed display high intraday reliability, revealing movements performed by the human stimulus (intraclass correlation coefficient (ICC): 0.71-0.99; coefficient of variation (CV): 1.11-4.77; typical error (TE): 0.15-0.59) and athlete running times (offensive: ICC: 0.91; CV: 3.30; TE: 0.06, defensive: ICC: 0.90; CV: 3.60; TE: 0.05) to be reliable. Further, no significant differences (p ≥ 0.05) were observed for human stimulus movement variables or athlete running times between the two testing sessions, however athletes produced a significantly faster running time (p= 0.009) during the defensive condition. Results suggest the movements performed by a human stimulus can be reliable supporting the implementation of a human stimulus during agility protocols to detect the smallest worthwhile change in athletic performance. Further, the results indicate the importance of measuring athlete’s agility performance during both offensive and defensive conditions as a guide for training programs to improve agility performance.
Study 3: Comparison of running times during a change of direction, offensive and defensive agility protocol. Change of direction (COD) movements are often performed under offensive and defensive situations to evade or pursue opponents. Currently response times, have been quantified during COD and defensive agility conditions, thus there is a need to investigate athlete’s response times during offensive agility conditions. Specific response times; reaction time (RT), movement time (MT) and total movement time (TMT) were identified to determine if a significant difference in response time occur between genders during COD and agility protocols. Twelve male and female (n=24) recreational team sport athletes participated in this study, with each athlete performing 10 COD trials and 12 offensive and 12 defensive agility trials in response to movements of a human stimulus. Comparison of response times reveal male athletes demonstrate a significantly faster (p = 0.001; ES = 1.82) TMT (0.32 s) during the COD protocol, and a significantly faster (p = 0.001; ES = 0.52 – 0.74) RT (0.39 s) and TMT (0.245 s) compared to females during both offensive and defensive agility protocols. Although no significant differences were observed, females produced a faster TMT during the defensive condition, whilst males were faster during the offensive condition. The results of this study indicate both COD and agility protocols are able to detect differences in performance between genders. These findings also highlight the importance to isolate and measure specific movement times during both offensive and defensive conditions to gain further insight to athlete’s agility performance.
Study 4: Comparison of force profiles between genders and strength during pre-planned change of direction movements. The aim of this study was to compare the magnitude of vertical and horizontal force-time and impulse variables between genders and lower body strength during a 45° change of direction (COD) test. Twelve male and female (n=24) recreational team sport athletes participated in this study. Each subject performed 10 pre-planned COD trials (5 left, 5 right) to collect relevant ground reaction force and impulse data. Subjects were further split into stronger and weaker groups based on unilateral isometric strength measurements of dominant and non-dominant limbs. Group (gender; strength level) by leg dominance (2x2) MANOVA’s were conducted to examine differences between groups across all variables, with follow up ANOVA’s conducted to determine where significant differences (p ≤ 0.05) occurred. Significantly faster post-stride velocity and greater vertical braking force, braking impulse and propulsive force was observed for males and the stronger group. Additionally, the stronger group demonstrated a significantly greater vertical propulsive impulse, horizontal braking force and angle of maximum braking force application, further highlighting strength as an important mechanism underpinning COD movements. This preliminary study demonstrates that specific force-time and impulse variables differ between genders and strength indicating training programs should targeted towards improving lower body strength and power to produce a faster COD performance.
Study 5: Ground reaction force application during offensive and defensive agility manoeuvers in male and female athletes. The aim of this study was to compare the magnitude of vertical ground reaction force-time and impulse variables during an offensive and defensive agility protocol between genders. Twelve male and female (n=24) recreational team sport athletes participated in this study, each performing 12 offensive and 12 defensive agility trials (6 left, 6 right) to collect relevant ground reaction force (GRF) and impulse data. Subjects also completed six unilateral isometric back squats to determine peak force for each limb and limb dominance. Group (gender) by condition (2x2) MANOVA’s were conducted to examine differences between groups across all variables, with follow up ANOVA’s conducted to determine where significant differences (p ≤ 0.05) occurred. The results indicate male subjects demonstrate a significantly greater braking force and impulse, lower body strength, and a faster initial reaction to the stimulus, enabling a faster post-stride velocity and reacceleration in the new direction compared to female subjects, during offensive and defensive agility conditions. Further differences between offensive and defensive conditions appear to be attributed to differences in reaction time and processing speed between genders. This preliminary study demonstrates that specific force-time and impulse variables differ between genders during offensive and defensive agility conditions, indicating the importance to assess and train athletes under both conditions to improve overall agility performance.
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Kiattisaksri, Chatcharit. "Time-Resolved and In-Situ Study on Evolution of Spheroidal Graphite Nodules and Volume Change During Solidification in Ductile Cast Iron." Kyoto University, 2019. http://hdl.handle.net/2433/244548.
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Burström, Kristina. "Population health and inequalities in health : measurement of health-related quality of life and changes in QALYs over time in Sweden /." Stockholm : Karolinska institutets bibl, 2003. http://diss.kib.ki.se/2003/91-7349-472-0/.
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Smith, N. J. "The study of criticality : an investigation based on network theory into the relationship between time and cost in civil engineering bridgeworks contracts and the measurement of the effects of change." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233393.
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Bäckström, Erik. "Time-Resolved Spectroscopy and Intensity Measurements of Singly Charged Ions." Doctoral thesis, Stockholms universitet, Fysikum, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-113503.
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This thesis is mainly concerned with investigations of spontaneous radiatively decaying states in both negative and positive singly charged ions. When possible, the measured lifetime of the state has been combined with branching fractions in order to derive the absolute transition probability (A-value) between different quantum states. The radiative transition probability between two quantum states is a fundamental atomic property. Knowledge of this property can be used as a diagnostic tool in, for example, abundance and temperature determinations with applications in many fields, e.g. astronomy, plasma physics, atomic physics etc. The focus of the experiments has been on lifetime measurements of long-lived metastable states. Lifetimes of long-lived metastable states are interesting in both theoretical aspects as well as the challenge it poses to the experimentalist. To perform such experiments, impact from the surrounding environment on the stored ions has to be kept to a minimum for extended periods of time. The metastable lifetimes presented here have been measured with time-resolved laser spectroscopic techniques in two different types of ion storage rings. One of them is a new type of unique cryogenically cooled storage ring made of purely electrostatic ion optical elements. As is demonstrated in this thesis, this device opens up a completely new time domain where lifetime measurements now can be performed. In addition, this thesis includes a discussion and preliminary studies of weak interactions otherwise limited by magnetic fields and/or thermal radiation from the environment. When available, the results have been compared to previous measurements and theoretical calculations which enables an evaluation of different methods and theoretical models.At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 6: Accepted.
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Cayzac, Witold. "Ion energy loss at maximum stopping power in a laser-generated plasma." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00949958.
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In the frame of this thesis, a new experimental setup for the measurement of the energy loss of carbon ions at maximum stopping power in a hot laser-generated plasma has been developed and successfully tested. In this parameter range where the projectile velocity is of the same order of magnitude as the thermal velocity of the plasma free electrons, large uncertainties of up to 50% are present in the stopping-power description. To date, no experimental data are available to perform a theory benchmarking. Testing the different stopping theories is yet essential for inertial confinement fusion and in particular for the understanding of the alpha-particle heating of the thermonuclear fuel. Here, for the first time, precise measurements were carried out in a reproducible and entirely characterized beam-plasma configuration. It involved a nearly fully-stripped ion beam probing a homogeneous fully-ionized plasma. This plasma was generated by irradiating a thin carbon foil with two high-energy laser beams and features a maximum electron temperature of 200 eV. The plasma conditions were simulated with a two-dimensional radiative hydrodynamic code, while the ion-beam charge-state distribution was predicted by means of a Monte-Carlo code describing the charge-exchange processes of projectile ions in plasma. To probe at maximum stopping power, high-frequency pulsed ion bunches were decelerated to an energy of 0.5 MeV per nucleon. The ion energy loss was determined by a time-of-flight measurement using a specifically developed chemical-vapor-deposition diamond detector that was screened against any plasma radiation. A first experimental campaign was carried out using this newly developed platform, in which a precision better than 200 keV on the energy loss was reached. This allowed, via the knowledge of the plasma and of the beam parameters, to reliably test several stopping theories, either based on perturbation theory or on a nonlinear T-Matrix formalism. A preliminary analysis suggests that the energy deposition at maximum stopping power is significantly smaller than predicted, particularly, by perturbation approaches.
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Sam, Yao Long. "Surface charge measurement by the Pockels effect." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392652.
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Ünalan, Zeynep. "A measurement of the top quark's charge." Diss., Connect to online resource - MSU authorized users, 2008.
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LI, LI. "NANOSCALE CHARGE DENSITY MEASUREMENT IN LIQUID WITH AFM." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1599744539112356.
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Klenkler, Richard A. Xu Gu POPOVIC ZORAN D. "Measurement of charge transport through organic semiconducting devices." *McMaster only, 2006.
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Bono, Jason S. "First Time Measurements of Polarization Observables for the Charged Cascade Hyperon in Photoproduction." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1520.
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The parity violating weak decay of hyperons offers a valuable means of measuring their polarization, providing insight into the production of strange quarks and the matter they compose. Jefferson Lab’s CLAS collaboration has utilized this property of hyperons, publishing the most precise polarization measurements for the Λ and Σ in both photoproduction and electroproduction to date. In contrast, cascades, which contain two strange quarks, can only be produced through indirect processes and as a result, exhibit low cross sections thus remaining experimentally elusive.
At present, there are two aspects in cascade physics where progress has been minimal: characterizing their production mechanism, which lacks theoretical and experimental developments, and observation of the numerous excited cascade resonances that are required to exist by flavor SU(3)F symmetry. However, CLAS data were collected in 2008 with a luminosity of 68 pb−1 using a circularly polarized photon beam with energies up to 5.45 GeV, incident on a liquid hydrogen target. This dataset is, at present, the world’s largest for meson photoproduction in its energy range and provides a unique opportunity to study cascade physics with polarization measurements.
The current analysis explores hyperon production through the γp → K+K+Ξ− reaction by providing the first ever determination of spin observables P, Cx and Cz for the cascade. Three of our primary goals are to test the only cascade photoproduction model in existence, examine the underlying processes that give rise to hyperon polarization, and to stimulate future theoretical developments while providing constraints for their parameters. Our research is part of a broader program to understand the production of strange quarks and hadrons with strangeness. The remainder of this document discusses the motivation behind such research, the method of data collection, details of their analysis, and the significance of our results.
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Bryson, Elzbieta Anna. "Electrode measurement on the net charge on muscle proteins." Thesis, Open University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339914.
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Kaya, Zahit Evren. "Time Synchronization In Measurement Networks." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12611585/index.pdf.
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AMR (Automatic Measurement Reading) applications usually require measurement data to be collected from separate locations. In order to combine the data retrieved from separate sources into a meaningful result, all sources should share a common time sense. Therefore, it is necessary to implement a synchronization scheme in measurement networks. In this thesis, a synchronization scheme which combines GPS (Global Positioning System) and two high accuracy WSN (Wireless Sensor Network) time synchronization algorithms will be proposed and evaluated. The synchronization accuracy of the proposed method is compared to the accuracy of NTP (Network Time Protocol) by simulation. This research work is fully supported by the Public Research Grant Committee (KAMAG) of TUBiTAK within the scope of National Power Quality Project of Turkey with the project No: 105G129.
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Erhardt, Herbert J. "A novel test structure for automated measurement of charge transfer efficiency in charge coupled imaging devices /." Online version of thesis, 1991. http://hdl.handle.net/1850/11267.
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Ji, Lin. "Increasing Accuracy of Location Determination : Exploiting Phase Change Reconstruction and Timing Measurements." Thesis, KTH, Kommunikationssystem, CoS, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91993.
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The thesis deals with improving location determination when using time of flight of radio signals to determine the location of a radiator. The goal of this project is to enhance an existing wireless data access point to perform an accurate measurement of the time of arrival of a data signal from a transmitter, and to combine this information with information from additional wireless data access points to determine the location of the transmitter. There have been a number of earlier efforts in indoor location determination system using different technologies. Many of which used signal strength analysis and they have low tolerance to moving obstacles such as humans, which frequently are the most usual dynamic obstacles in indoors. In this thesis, the proposed solution utilizes time stamping and sample correlation to utilize properties of the signal waveform, which has not previously been examined by researchers other than the examiner and advisor. The main contribution of the project is a detailed analysis and design of a solution, as well as a comparison with other potential solutions. The main purpose of this solution is to increase the timing accuracy to below the duration of a single symbol. The wireless device that has been analyzed implements the IEEE 802.11b protocol. Several investigations have been done to determine the best way of extracting information from the 802.11b data frame and symbol sequence; here we utilize a correlator to determine the time of arrival of a specific sequence of symbols in a data frame. The time stamping of a stream of samples has been implemented in an Altera FPGA to get a deterministic computation time. Instead of decoding the incoming I&Q signals and mapping them to bits, the correlator is used to detect the unique sequence containing PSK encoded and Barker code spread scrambled ones , as this sequence always appears at the start of each data frame. The advantage of this approach is that using of samples of the waveform instead of bits gives a significant enhancement in timing resolution. The design documents of this work include detailed descriptions, simulations, and plots. A number of simulations have been done to show the timing accuracy and standard deviation, as well as comparisons with several different approaches. Several potential optimizations have also been discussed in the report. Simulation code for MATLAB and implementation code for the FPGA has been included in appendices in the end of this thesis.Denna rapport beskriver ett examensarbete som utgår ifrån att förbättra noggrannhet av en lokaliseringsteknik som tillämpar flygtiden av radiosignal för att mäta positionen av utsändaren. Målet av detta arbete är att förstärka en befintlig trådlösdata accesspunkt för att utföra en noggrann mätning av signals anländning från sändaren, och kombinera denna information från ytterliga trådlösdata accesspunkter för att lokalisera sändaren. Det har varit ett antal utvecklingar med olika teknologier för att ta fram en lösning för inomhus lokaliseringssystem. Många av de förslag som har kommit fram tillämpa signalstyrka och har en dålig tolerans av rörande hinder så som människor, vilka är det vanligaste fallet inomhus. Denna rapport ger ett förlag att lösa detta problem med att tillämpa tidstämpel och sampelkorrelation för att utnyttja egenskaper av signalens vågform, ett förlag som inte har blivit undersökt mycket av andra forskare. Stor del av denna rapport består av detaljerad analys och lösningsdesign, plus en jämförelse med andra potentiella lösningar. Meningen med denna lösning är att öka noggrannhet till att felmarginal i tid ska ligga under en symboltid. Den trådlösa enhet som har analyserats implementerar IEEE 802.11b protokollen. Flera undersökningar har utförts för att bestämma det bästa sättet att extrahera information från 802.11b dataramer och symbolsekvenser. För att göra det har vi implementerat en korrelator för att bestämma anländningstid av specifika symbolsekvenser i en dataram. En Altera FPGA har använts för att tidstämpla inkommande sampel för att ge en deterministisk beräkningstid. Istället för att avkoda inkommande I&Q signaler och mappa dem till bitar, har vi valt att implementera korrelator så att den opererar direkt på PSK-modulerade och Barkerkod-spridda ettor, eftersom att det visar sig att denna sekvens alltid visar sig i början av varje dataram. Fördelen med denna lösning är att direktanvändning av sampel ger en signifikant ökning på tidsupplösning jämfört med bitar. Designdokumentet av detta examensarbete består av detaljerade beskrivningar, simuleringar och grafer. Ett antal simuleringar har utförts för att visa tidsnoggrannhet och medelfel, plus jämförelser mellan olkia lösningsförslag. Olika möjliga optimeringar har också diskuterats i rapporten. Simuleringskod för MATLAB och implementeringskod FPGA bifogas i appendix slutet av denna rapport.
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Hartmann, Udo. "Decoherence and Measurement of Charge Qubits in Double Quantum Dots." Diss., lmu, 2005. http://nbn-resolving.de/urn:nbn:de:bvb:19-44155.
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Xu, Zhiqiang. "Space charge measurement and analysis in low density polyethylene films." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/69927/.
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The growing requirement of reliability for an insulation system gives researchers greater responsibility to investigate new techniques for monitoring and diagnosing dielectrics subjected to an electric field. It is well known that the presence of space charge is one of the important factors causing premature failure of polymeric high voltage cables. Space charge surveillance is becoming the most general applied skill to evaluate polymeric materials, particularly high voltage cables. The well-known pulsed electroacoustic method (PEA), a reliable non-destructive method, gives a reasonable resolution to the concentration of the space charge in the insulation material. My work contributes to the measuring of space charge in low density polyethylene using PEA. From the experiments to study space charge formation and distribution at the interface on multi-layer sample under DC and AC applied voltage, electrode materials and frequency are determined as two important factors in measuring the charge injection and distribution; the interface between films acts as a trap for charge carriers, especially for electrons; and positive charge has a high mobility compared to negative charge. Surface potential decay was studied to explain the crossover phenomenon and to find physical mechanism on charge decay of the corona charged film sample. Charge mapping technique (PEA) was successfully introduced to the potential study and it provides an alternative way to investigate charge decay process and allows monitoring charge migration through the bulk of corona charged film. One essential phenomenon, bipolar charge injection, has been first derived from the results of space charge distribution. The advanced PEA measurement system with high rate test and excellent phase resolving capability was designed in the last part of the study. Compared with the old system the new system can provide the enhanced experiment result for fast change situation, which can achieve high-quality diagnosis for the virtual industry situation such as polarity reversal and transient voltage failure.
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Bahcivancilar, Ugur. "Validation Of Methods Time Measurement Data." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614916/index.pdf.
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This thesis shows the results of an experiment in order to test the validity of Methods Time
Measurement (MTM) data. MTM, developed in 1948, is one of the most commonly used
Predetermined Motion Time Systems to calculate standard time for a task. However, there is
limited research on the validity of the MTM data in the literature. Today&rsquos technology provides new computerized tools to perform time studies. One of such tools is Real Time Method Study (RTMS). RTMS is a computerized method study tool being developed in METU Technopolis, which uses Image Processing and Machine Learning to conduct time studies automatically. RTMS uses MTM data as a benchmark data to compare observed performance results
therefore validity of MTM data is an important issue for it. In order to test the validity of MTM data an experiment conducted in the Ergonomics Laboratory of the METU Industrial Engineering Department. In this experiment 40 undergraduate students performed four different tasks. These tasks were recorded by a video camera and analyzed frame by frame to calculate normal times for basic motions of MTM. Results are compared with the original MTM data and it is shown that MTM times do not fit the observed data. This study in the end suggests updating MTM data or constructing a new standard time database by using a tool like RTMS.
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Colbert, Michael Anestis. "A real-time optical measurement system." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/41903.
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Suttle, Perry M. "Effects of charge density rise time upon Cerenkov radiation." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA237682.
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Thesis (M.S. in Physics)--Naval Postgraduate School, June 1990.Thesis Advisor(s): Neighbours, J.R. Second Reader: Colson, W. B. "June 1990." Description based on title screen as viewed on October 16, 2009. DTIC Identifier(s): Rise Time Effects. Author(s) subject terms: Cerenkov Radiation, Semi-Infinite Path, Rise Time Effects. Includes bibliographical references (p. 51). Also available in print.
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Bagga, Payel. "Measurement of Electrostatic Dipoles and Net Charge on Air Dispersed Particles." Thesis, University of Canterbury. Chemical and Process Engineering, 2009. http://hdl.handle.net/10092/2992.
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Dipoles are expected to often dramatically enhance the mutual collision rate of diffusing particles (above the effects of Brownian or turbulent motion). However, this spreading awareness of the possible influence of discrete dipoles on particles is still based largely on theory, and some qualitative experience of particle behaviour from microgravity experiments. Individual particle dipoles have not yet been definitely isolated in experiments, nor measured in practical situations. In this project, it was intended to measure, for the first time, distributions of dipole strength (as well as net charge and particle size) on particulates dispersed into air by typical industrial and pharmaceutical processing methods.
The instruments designed to do this were built around a sampling head which allowed examination of a flow of dust dispersed into an air stream. During dispersal, the particles suffered tribocharging by mutual separation and collision on walls. Examination of the particles involved recording the path of particles as they moved through a non-uniform electric field around a central electrode, which was supplied with high voltage. Particles were attracted towards the central electrode (of 0.5 mm diameter in this study) if they contained dipoles, independent of the polarity of the field or their net charge. Particles to be examined were illuminated by a laser sheet as they moved past, and a high speed video captured their trajectories (over a field of view of around 5 mm).
The equation of motion of a particle which involved the forces of both particle net charge and dipole strength was applied to the particle path to evaluate both these parameters. The particle trajectories were modelled, and checked against the observed experimental trajectories. The voltage applied to the probe varied from 4 kV to 18 kV but for most of the runs 6 kV voltage was used. The electric field around the probe tip was assumed to be same as that for a spherical electrode of the same size as the probe. The flow field axially towards and around the probe tip was calculated using the Stokes creeping flow equations around a sphere. The calculated electric and flow fields were checked against COMSOL Multiphysics models applied to actual geometries and flow regimes.
The rotation dynamics of the particles was also considered important in the technique, requiring possibly extra knowledge of the initial direction of the dipole. The flow was led through a lateral field between two plates in order to orient the direction of any dipoles in the direction of the lateral field. The expected orientation of dipoles coming out of the plates was used as an initial guess of their orientation for modelling the rotation of the dipoles when they entered the probe field. Misalignment after leaving the plate field and before entering the probe field was also considered, and was found to be important due to vortices characterised by smoke and particle studies. However, the trajectory modelling revealed that the particles studied quickly rotated into alignment with the probe field, providing maximum attractive force to the probe, and so the values of net charge and dipole strength obtained did not depend on the initial orientation.
Estimated errors of particle position and diameter used in all the calculation steps were judged to be well within a basic image error limit of ±1 pixel. Some particle trajectories showed unexplainable shapes which was traced to the influence of large mixing eddies around the gas/particle jet. A check for corona discharge at the probe tip was made both at the beginning and at the end of the sampling experiments. No corona was detected initially (up to 18 kV), but a discharge could be observed at voltages close to 7 kV in the later checks.
Particles of acrylic, glass bubbles, whole milk and fertiliser powder were sampled and net charges and dipole charges were estimated. The sampled particles overall had net charge and dipole charge in the range of 10-15 C to 10-12 C on individual particles with diameters 20 μm -130 μm. Dipoles were more evident (more easily measured) for glass bubbles but the presence of dipoles on other particle samples was found and could not be completely ruled out for many of them. The analysis procedure is presently time consuming but can be automated so it is recommended in the future that it should be automated. The work can be extended into industrial situations by sampling moving dust suspensions, e.g. fluid bed overflows and pneumatically conveyed outflows, useful in the dairy and fertilizer industries.
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Leckey, John Poague IV. "The first direct measurement of the weak charge of the proton." W&M ScholarWorks, 2012. https://scholarworks.wm.edu/etd/1539623594.
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Qweak is an experiment currently running at the Thomas Jefferson National Accelerator Facility that uses parity-violating elastic electron-proton scattering to measure the weak charge of the proton QPweak . Longitudinally polarized electrons are scattered off a liquid hydrogen target and pass through a toroidal-field magnetic spectrometer. This experiment is a sensitive test for physics beyond the Standard Model, as QPweak is well predicted in the Standard Model. This dissertation describes the first direct measurement of QPweak . The precision that will be generated by the final 4% measurement will allow the probing of certain classes of new physics up to 2.5 TeV. In this dissertation, the design and status of the complete experiment are discussed, including the details of the asymmetry measurements and preliminary results from several studies of experimental systematics. This dissertation also includes a full description of the design, construction, commissioning, and use of the vertical drift chambers (VDC) used in the Qweak experiment to measure the scattered electron's profile and the momentum transfer (Q 2) of the ep scattering. The Q 2 was measured to be 0.0274 +/- 0.0013 GeV2/c 2 and QPweak was measured to be 0.102 +/- 0.036, which is consistent with the Standard Model.
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Mauri, Nicoletta <1980>. "Measurement of the atmospheric muon charge ratio with the OPERA detector." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3932/1/Mauri_Nicoletta_Tesi.pdf.
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The atmospheric muon charge ratio, defined as the number of positive over negative charged muons, is an interesting quantity for the study of high energy hadronic interactions in atmosphere and the nature of the primary cosmic rays. The measurement of the charge ratio in the TeV muon energy range allows to study the hadronic interactions in kinematic regions not yet explored at accelerators.
The OPERA experiment is a hybrid electronic detector/emulsion apparatus, located in the underground Gran Sasso Laboratory, at an average depth of 3800 meters water equivalent (m.w.e.). OPERA is the first large magnetized detector that can measure the muon charge ratio at the LNGS depth, with a wide acceptance for cosmic ray muons coming from above.
In this thesis, the muon charge ratio is measured using the spectrometers of the OPERA detector in the highest energy region.
The charge ratio was computed separately for single and for multiple muon events, in order to select different primary cosmic ray samples in energy and composition. The measurement as a function of the surface muon energy is used to infer parameters characterizing the particle production in atmosphere, that will be used to constrain Monte Carlo predictions.
Finally, the experimental results are interpreted in terms of cosmic ray and particle physics models.
34
Mauri, Nicoletta <1980>. "Measurement of the atmospheric muon charge ratio with the OPERA detector." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3932/.
Full textAbstract:
The atmospheric muon charge ratio, defined as the number of positive over negative charged muons, is an interesting quantity for the study of high energy hadronic interactions in atmosphere and the nature of the primary cosmic rays. The measurement of the charge ratio in the TeV muon energy range allows to study the hadronic interactions in kinematic regions not yet explored at accelerators.
The OPERA experiment is a hybrid electronic detector/emulsion apparatus, located in the underground Gran Sasso Laboratory, at an average depth of 3800 meters water equivalent (m.w.e.). OPERA is the first large magnetized detector that can measure the muon charge ratio at the LNGS depth, with a wide acceptance for cosmic ray muons coming from above.
In this thesis, the muon charge ratio is measured using the spectrometers of the OPERA detector in the highest energy region.
The charge ratio was computed separately for single and for multiple muon events, in order to select different primary cosmic ray samples in energy and composition. The measurement as a function of the surface muon energy is used to infer parameters characterizing the particle production in atmosphere, that will be used to constrain Monte Carlo predictions.
Finally, the experimental results are interpreted in terms of cosmic ray and particle physics models.
35
Sedlák, Daniel. "Posouzení časových změn kalibračních charakteristik vodoměrných vrtulí." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392212.
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Diploma’s thesis is focused on analysis of the time changes of calibration characteristics independent type of current-meters, processing by the calibration data and their evaluation and subsequent comparison with related research. This thesis describes the proces of calibration of current-meters.
36
Segbeaya, Sami Fiwovi 1955. "TIME-RESOLVED MEASUREMENTS OF COAL DEVOLATILIZATION." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/277281.
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Condrau, Marc Anton. "Time-resolved fluorescence measurement in flow cytometry /." [S.l.] : [s.n.], 1993. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10267.
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Breitner, Susanne. "Time-varying coefficient models and measurement error." Diss., lmu, 2007. http://nbn-resolving.de/urn:nbn:de:bvb:19-79772.
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Segoviano, Miguel A. "Portfolio credit risk through time : measurement methodologies." Thesis, London School of Economics and Political Science (University of London), 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420703.
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The estimation of the profit and loss distribution of loan portfolios requires the modelling of the marginal and multivariate distributions that describe the individual and joint credit risk of the loans making up a portfolio. Unfortunately, portfolio credit risk measurement suffers from extremely restricted datasets. For many countries, this problem holds at any point in time and through time. It is especially severe when modelling the credit risk of loans given to small and medium size enterprises (SME's) and non-listed firms, which are the focus of my research. Earlier attempts to deal with this problem have resulted in measurement methodologies adopting convenient, but not necessarily properly specified, parametric distributions or simply ignoring the effects of macroeconomic developments in credit risk. In order to improve the measurement of portfolio credit risk at any point in time and through time, I propose new methodologies, i. e. the consistent information density optimising (CIDO), the consistent information multivariate density optimising (CIMDO), and the conditional probability of default (CoPoD) methodologies. CIDO and CIMDO are based on the cross-entropy approach. They recover the marginal and multivariate distributions of the loans that make up a portfolio from the limited information available. Using the Probability Integral Transformation and the Probability Squared Deviations criteria, it is proved that the distributions recovered by CIDO and CIMDO outperform parametric distributions. CoPoD is based on the pure-entropy approach. It allows for the modelling of the probabilities of loan default (PoD's) as functions of macroeconomic variables. The latter represents a challenging task, since the time series of PoD's usually contain few observations; thus making OLS estimation imprecise. CoPoD recovers estimators that show superior robustness to OLS estimators in finite sample settings under the mean square error criterion. CoPoD also incorporates a procedure to select a relevant set of explanatory variables that explain PoD's through time.
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Crane, Bryan Lee 1976. "Real time PCR measurement by fluorescence anisotropy." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/30347.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, February 2005.Page 230 blank.
Includes bibliographical references (p. 181-190).
Real-time polymerase chain reaction (PCR) is the gold-standard for quantitation in both mutation and gene expression analyses. Already this technique has found valuable clinical application in disease diagnosis and progression evaluation. As the number of known gene-disease correlations continues to rise, there will be increased demand for higher throughput and decreased cost for these analyses. Present real-time PCR measurement is based upon the fluorescent intensity of either intercalating dyes or oligonucleotide probes. Intercalating dye methods suffer from a lack of binding specificity, while probe methods are expensive and require increased assay optimization. In this thesis, a new method is presented for monitoring real-time PCR that utilizes the fluorescent anisotropy (FA) of labeled primers. FA, when measured at constant temperature, is indicative of the molecular mass to which the fluorophore is attached. Specificity is improved with the FA method over the use of intercalating dyes since the selective binding of primers is required for signal change. Assay complexity and cost are reduced compared to fluorogenic probe methods since the probes are eliminated. The design of a prototype instrument, which successfully implements this new method, is presented. Instrument and assay performance are compared to intercalating dye assays run in commercially available instrumentation. Theoretical limits on performance are also presented and compared to experimental results. Excellent repeatability and linearity are observed with respect to these benchmarks. This new method, having both high specificity and low optimization complexity, is expected to be particularly applicable to the demanding robustness requirements of nano-scale PCR.
by Bryan Lee Crane.
Ph.D.
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Arntzenius, Frank Willem. "Time reversibility, determinism and measurement in physics." Thesis, London School of Economics and Political Science (University of London), 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.694647.
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McCleese, Christopher. "Femtosecond Time-Resolved Spectroscopy Studies of Interfacial Charge Separation Processes." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case149182204612303.
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Whitehead, Samuel Robert. "A measurement of the W boson charge asymmetry with the ATLAS detector." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:3eba7629-7ec3-4536-afd1-a804c6fc48f4.
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Uncertainties on the parton distribution functions (PDFs), in particular those of the valence quarks, can be constrained at LHC energies using the charge asymmetry in the production of W± bosons. This thesis presents a measurement of the electron channel, lepton charge asymmetry using 497 pb-1 of data recorded with the ATLAS detector in 2011. The measurement is included in PDF fits using the machinery of HERAPDF and is found to have some constraining power beyond that of existing W charge asymmetry measurements.
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Ho, Yiu Fai Fred. "Space charge measurement of XLPE : a comparison of AC and DC stressing." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390713.
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Fu, Mingli. "Space charge measurement in polymer insulated power cables using the PEA method." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395997.
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Duvall, Wade Sayer. "Precision Measurement of the Proton's Weak Charge using Parity-Violating Electron Scattering." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/89476.
Full textAbstract:
The Qweak experiment has precisely determined the weak charge of the proton Qp w by measuring the parity-violating asymmetry in elastic electron-proton scattering at a low momentum transfer of Q2 = 0.0249 (GeV/c)2 . Qpw has a definite prediction in the Standard Model, and a value of sin2 θW can be extracted from it for comparison with other neutral current observables. Qweak measured the weak charge of the proton to be Qpw(P V ES) = 0.0719 ± 0.0045, which is consistent with the Standard Model value of Qp w(SM) = 0.0708 ± 0.0003. Qweak ran at the Thomas Jefferson National Accelerator Facility for two and a half years and was installed in experimental Hall C. A 180µA beam of longitudinally polarized electrons at 1.16 GeV scattered off a liquid hydrogen target of unpolarized protons. The electrons were collimated to an acceptance of 5.8◦ to 11.6◦ and then passed through a magnetic spectrometer and onto quartz Čerenkov detector bars.
A detailed description of the theory and motivation behind the Qweak experiment is given. An overview of the Qweak apparatus and an in-depth discussion of the luminosity monitor performance is presented. A general overview of the Qweak analysis is also presented, with a focus on the beamline background correction, the nonlinearity measurement, and the simulation to constrain error for a rescattering effect. Also detailed here is the final, unblinded Qweak result, which determined Qpw to 6.2% and provided the highest precision measurement of sin2θW at low energy.PHD
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Alahmadi, Ahmed Naif M. "Reconfigurable time interval measurement circuit incorporating a programmable gain time difference amplifier." Thesis, University of Newcastle Upon Tyne, 2013. http://hdl.handle.net/10443/1807.
Full textAbstract:
As further advances are made in semiconductor manufacturing technology the performance of circuits is continuously increasing. Unfortunately, as the technology node descends deeper into the nanometre region, achieving the potential performance gain is becoming more of a challenge; due not only to the effects of process variation but also to the reduced timing margins between signals within the circuit creating timing problems. Production Standard Automatic Test Equipment (ATE) is incapable of performing internal timing measurements due, first to the lack of accessibility and second to the overall timing accuracy of the tester which is grossly inadequate. To address these issue ‘on-chip’ time measurement circuits have been developed in a similar way that built in self-test (BIST) evolved for ‘on-chip’ logic testing. This thesis describes the design and analysis of three time amplifier circuits. The analysis undertaken considers the operational aspects related to gain and input dynamic range, together with the robustness of the circuits to the effects of process, voltage and temperature (PVT) variations. The design which had the best overall performance was subsequently compared to a benchmark design, which used the ‘buffer delay offset’ technique for time amplification, and showed a marked 6.5 times improvement on the dynamic range extending this from 40 ps to 300ps. The new design was also more robust to the effects of PVT variations. The new time amplifier design was further developed to include an adjustable gain capability which could be varied in steps of approximately 7.5 from 4 to 117. The time amplifier was then connected to a 32-stage tapped delay line to create a reconfigurable time measurement circuit with an adjustable resolution range from 15 down to 0.5 ps and a dynamic range from 480 down to 16 ps depending upon the gain setting. The overall footprint of the measurement circuit, together with its calibration module occupies an area of 0.026 mm2 The final circuit, overall, satisfied the main design criteria for ‘on-chip’ time measurement circuitry, namely, it has a wide dynamic range, high resolution, robust to the effects of PVT and has a small area overhead.
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Zhang, Kai. "Air charge system emulation for diesel engine." Thesis, University of Bath, 2010. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521014.
Full textAbstract:
The work presented in this thesis details a novel engine evaluation approach utilising real-time simulation and advanced engine testing systems for general applicability to new generations of air charging systems. A novel engine air charging system including a charge air handling unit (CAHU) has been developed which is connected to an engine to emulate advanced boosting system conditions. Significant analytical and development work has focused on generating a real-time turbocharger model such that the CAHU can be effectively controlled to emulate the turbocharger performance under both steady and pulsating conditions. Experimental work was carried out to evaluate this new engine air charge testing system against a production turbocharged baseline engine. The accuracies with respect to the boost pressure, turbocharger speed, mass air flow, and fuel consumption in the steady state tests are above 95%, and the level of confidence for the engine back pressure is approximately 90%. The difference of turbocharger speed between the steady turbocharger model and the pulsation model is also identified. In engine transient tests, the boost pressure and engine torque have shown fast response characteristics similar to that of the baseline engine. While general transient trends were achieved, some issues were identified with the high speed control of the CAHU interacting with the dSPACE real time turbocharger model. It is proposed that future improvement can be achieved via applying new control algorithms to improve the accuracy and tracking the CAHU control without increasing the system instabilities.
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Shamsudin, Nebil. "A Device for Measurement of Capillary Refilling Time." Thesis, Linköpings universitet, Biomedicinsk instrumentteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-81496.
Full textAbstract:
The main objective of this project is to design, construct and validate a portable prototype of a device that is capable of performing a test to accurately measure Capillary Refilling Time (CRT), and to analyze the results with defined parameters; force, area, pressure (compression) and time. This prototype is dedicated to study and evaluate CRT readouts for different pressure values, collected from healthy subjects.The presented prototype of this study is capable of producing skin compressing and to measure the refilling time of capillaries following this compression. This prototype introduces accuracy, mechanical reproducibility and controlling options for the applied pressure and compression time. The presented prototype is non-invasive, portable and it can be used to conduct more CRT tests and other capillary refilling studies.CRT measurement is done by calculating time interval starting from the first point when the applied pressure is released; ending with the recording point at the time when the concentration of red blood cells has reached the level of its pre-occlusion values.Based on the calculated CRT values and the number of iterations of the test in CRT tables, one can observe that given the same applied pressure value, CRT values do not significantly vary when the test is repetitively conducted on the same subject and on the same site.
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Longanbach, David Michael. "Real-time measurement for an internal grinding system." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/15903.
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