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1
Huang, Yiqun. "The effects of fuel volatility, structure, speed and load on HC emissions from piston wetting in direct injection spark ignition engines." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3035951.
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Bell, Harold James. "The effects of constant vs. interval load training at and about the first ventilatory threshold on endurance performance indicators." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ52020.pdf.
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Gutierrez-Franco, Juan. "THE EFFECTS OF OBESITY ON RESULTANT KNEE JOINT LOADS FOR GAIT AND CYCLING." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1624.
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Osteoarthritis (OA) is a degenerative disease of cartilage and bone tissue and the most common form of arthritis, accounting for US$ 10.5 billion in hospital charges in 2006. Obesity (OB) has been linked to increased risk of developing knee OA due to increased knee joint loads and varus-valgus misalignment. Walking is recommended as a weight-loss activity but it may increase risk of knee OA as OB gait increases knee loads. Cycling has been proposed as an alternative weight-loss measure, however, lack of studies comparing normal weight (NW) and OB subjects in cycling and gait hinder identification of exercises that may best prevent knee OA incidence. The objective of this work is to determine if cycling is a better weight-loss exercise than gait in OB subjects as it relates to knee OA risk reduction due to decreased knee loads. A stationary bicycle was modified to measure forces and moments at the pedals in three dimensions. A pilot experiment was performed to calculate resultant knee loads during gait and cycling for NW (n = 4) and OB (n = 4) subjects. Statistical analyses were performed to compare knee loads and knee angles, and to determine statistical significance of results (p < 0.05). Cycling knee loads were lower than gait knee loads for all subjects (p < 0.033). OB axial knee loads were higher than NW axial knee loads in gait (p = 0.004) due to the weight-bearing nature of gait. No differences were observed in cycling knee loads between NW and OB subjects, suggesting cycling returns OB knee loads and biomechanics to normal levels. The lack of significant results in cycling could be due to the small sample size used or because rider weight is supported by the seat. Limitations to this study include small sample size, soft tissue artifact, and experimental errors in marker placement. Future studies should correct these limitations and find knee joint contact force rather than knee resultant loads using v EMG-driven experiments. In conclusion, cycling loads were lower than gait loads for NW and OB subjects suggesting cycling is a better weight-loss exercise than gait in the context of reducing knee OA risk.
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Pavelka, Radomil. "Pohon vřeten pětivřetenového soustružnického automatu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231522.
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The subject of the thesis is design of independent spindle drive for multi-spindle automatic lathe MORI-SAY TMZ 520 CNC manufactured by TAJMAC-ZPS. The thesis will introduce the representatives of manufacturing program of TAJMAC-ZPS multi-spindle automatic lathes division and there will be a brief description of their main constructional parts. The main objective of the thesis is an engineering design of testing device which will be bulit for verification of the correct drive concept. There is also many calculations and detailed description of the engineering design. The testing device is made for internal needs of TAJMAC-ZPS.
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Meunier, Pierre. "Psychophysical assessment of load-carrying in internal and external-frame backpacks." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-05022009-040630/.
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Güngör, Güven. "Biaxial Load Effects on Fatigue Properties." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19079/.
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This study aims to aid many issues related to fatigue, namely biaxial loading, the definition of the finite geometry correction factor of the stress intensity factor and the understanding of the energy dissipation per fatigue crack growth. In our work, we are using the geometry correction factor definition that uses the ratio
of external work introduced to the material. Using different biaxiality ratios varies the external work done, thus makes it possible for us to observe how the geometry correction factor handles this variation. The trend of strain energy release rate per crack growth is also investigated through biaxiality. Moreover,
the common discussion of the effects of biaxiality on fatigue properties is aided with yet another study. For this purpose, cruciform shaped plate specimen from an aluminum alloy are manufactured and biaxially loaded. Crack growth is observed while load-to-displacement data is recorded to evaluate the external work done on the specimen. As a result, it is seen that biaxiality delays the fatigue failure. Crack growth rates decreases as the biaxiality increases for a given effective stress intensity factor. Making use of the work values for the calculation of the finite geometry correction factor handles the effects of
biaxiality well. Strain energy release rate increases as the crack propagates, but there is no trend between strain energy release rate and biaxiality of the loading. In the future works, observing also the crack tip plasticity and trying out a wider range of biaxiality ratios with different types of material would result in more generalizable conclusions. Moreover, more repetitions of the fatigue tests would give more accurate values for the amount work introduced to the material with changing biaxiality.
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Sole, C. J., Caleb D. Bazyler, Ashley A. Kavanaugh, Satoshi Mizuguchi, and Michael H. Stone. "Relationship between Internal and External Estimates of Training Load Using Wearable Inertial Sensors." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/3837.
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PURPOSE: The purpose of the study was to examine the relationship between an external estimate of training load obtained from a wearable accelerometer device and perceived training load in women’s volleyball. METHODS: Participants of this study were thirteen NCAA Division I women’s volleyball players (Age: 20.3±1.2 y, height: 174.9±7.9cm, body mass: 68.1±12.7 kg). A wearable accelerometer device (Catapult Sports, MiniMaxX S4) was used to estimate external training load during volleyball practice sessions. In addition, following each session a rating of perceived exertion was obtained from each player using a 0-10 scale. Based on previously established methods, ratings of perceived exertion were then multiplied by the duration of practice in minutes to provide an estimate of internal training load. A Pearson product-moment zero order correlation coefficient was used to assess the relationship between external and internal training load estimates for each individual over eight practices. RESULTS: On average a positive relationship (r = 0.75±0.15) was found between training load estimates. Individual r values ranged from 0.39 to 0.92, with eight of the thirteen achieving statistical significance (p<0.05). CONCLUSIONS: Based on the relationships found between internal and external estimates of training load, both methods may be considered as an option for quantifying on-court training loads in NCAA women’s volleyball. However, the degree to which these estimates relate may vary by individual.
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Rashel, Masud Rana. "Modeling photovoltaic panels under variable internal and environmental conditions with non-constant load." Doctoral thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/23565.
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This thesis focuses on the modeling and simulation of photovoltaic electric energy
conversion systems, that considering different internal and environmental parameters,
important for the forecast of the electric energy production. For the cell or panel
modeling, the single diode five-parameter model is used. The internal parameters
considered are the photocurrent, the cell temperature, the ideality factor, the series
resistance, the shunt resistance and the saturation current; and on the other hand the
external parameters considered are solar irradiance, ambient temperature and wind
speed. New contributions are presented in the context of the modeling and simulation of
the error function that identifies the more and less sensitive internal parameters of the
cell model and the sensitivity of the external parameters. In the context of obtaining the
experimental results, a monocrystalline silicon photovoltaic panel is used. And a signal
generator, data acquisition device, an anemometer, a pyranometer and a sensor for
measuring the ambient temperature are used. In the context of internal relation between
external parameters, correlation studies are performed in order to show the relationships
between them; and the obstacle concept is presented as a generalization of shadow types,
namely dust and elements that reduce solar irradiance on the surface of the cell or panel; Modelação de painéis fotovoltaicos sob condições
internas e ambientais variáveis com carga não
constante
Resumo:
Esta tese incide sobre o tema da modelação e simulação de sistemas de conversão de
energia elétrica fotovoltaica considerando diferentes parâmetros internos e ambientais,
importantes para a previsão da produção de energia elétrica. Para a modelação da
célula ou do painel é utilizado o modelo de cinco parâmetros de um díodo. Os parâmetros
internos considerados são a corrente que atravessa o díodo, a temperatura interna da
célula, o fator de idealidade, a resistência série da célula, a resistência paralela da célula
e a corrente de saturação; os parâmetros externos considerados são a irradiância solar,
a temperatura ambiente e a velocidade do vento. São apresentadas novas contribuições
no contexto da modelação e simulação da função de erro que identifica os parâmetros
internos mais e menos sensíveis do modelo da célula e a sensibilidade dos parâmetros
externos. No contexto para a obtenção dos resultados experimentais foram utilizadas
células e um painel fotovoltaico de silício monocristalino respetivamente, um gerador de
sinais, dispositivos aquisição de dados, um anemómetro, um piranómetro e um sensor
para medir a temperatura ambiente. Em ambos contextos, são realizados estudos de
correlação entre os parâmetros externos no sentido de mostrar as relações entre eles; e
é apresentado o conceito de obstáculo como uma generalização dos tipos de sombras,
nomeadamente a poeira e elementos que reduzem a irradiância solar na superfície da
célula ou do painel.
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Brown, Iain. "Internal field effects in InGaN quantum wells." Thesis, Cardiff University, 2005. http://orca.cf.ac.uk/55968/.
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InGaN/GaN based quantum well structures are strained and due to the lack of a centre of symmetry large internal fields are present which skew the potential of the quantum wells, this has a large effect on the properties of these structures. InGaN/GaN based quantum well structures are studied using a theoretical method based on the Pade model and comparison made with experimental results. The importance of using a correct description for the depletion widths of p-i-n structures for use in interpreting measurements of the internal field is established in this work. Interpreting the results from reverse bias photocurrent absorption measurements of an In0.1Gao.9N quantum well structure, a value of-1.9 MVcm-1 for the internal field has been determined, which is within 5 % of the field of -1.8 MVcm-1 calculated using piezoelectric constants interpolated from the binaries. Comparison of the results of the Pade model and experiment demonstrate that the experimental absorption magnitude is an unreliable indication of the internal field due to the carrier extraction efficiency at low bias, hence the absorption peak energy should be used. Using a theoretical model governed by pumping and recombination processes time-resolved photoluminescence experiments performed at Sheffield University have been modelled. It was found that the observed shift of the emission peak arises from a delicate balance between the contributions from bandgap renormalisation, screening of the internal field and the Coulomb interaction. Comparisons between the free carrier and Pade models, found that the energy shift and magnitude of the peak intensity are underestimated when using the free carrier model. Although the internal field is strongly screened at high carrier density, the increase in the dipole matrix element is small. It was found that at threshold the screened internal field is still of the order of -1 MVcm-1, hence inclusion of the screened internal field is essential in laser gain-current calculation.
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Fedorov, Alexey V. "Nonlinear effects in surface and internal waves /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9737309.
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Sundaresan, Sasi Sekaran. "EFFECTS OF INTERNAL FIELDS IN QUANTUM DOTS." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/theses/244.
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In this work we study the effect of built in electrostatic fields in Quantum Dots. Built-in electrostatic fields in Zincblende quantum dots originate mainly from--(1) the fundamental crystal atomicity and the interfaces between two dissimilar materials, (2) the strain relaxation, and (3) the piezoelectric polarization. We also study the geometric dependence of built in fields on 3 shapes namely Box, Dome and Pyramid. The main objectives are 3 fold they are (1) Explore the nature and the role of crystal atomicity at the interfaces and built-in fields (strain-field, and piezoelectric polarization) in determining the energy spectrum and the wave functions. (2) To identify the shift in the one-particle energy states, symmetry-lowering and non-degeneracy in the first excited state and strong band-mixing in the overall conduction band electronic states. (3) Finally geometric dependence of the above-mentioned phenomena. We discuss the importance atomistic effects and the need for 3 dimensional atomistic simulator NEMO 3D. We also discuss the effect of built in fields in HEMT (High Electron Mobility Transistor).
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James, Gerard. "Analysis of traffic load effects an railway bridges." Doctoral thesis, KTH, Civil and Architectural Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3523.
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The work presented in this thesis studies the load and loadeffects of traffic loads on railway bridges. The increasedknowledge of the traffic loads, simulated using fieldmeasurements of actual trains, are employed in a reliabilityanalysis in an attempt at upgrading existing railwaybridges.
The study utilises data from a weigh-in-motion site whichrecords, for each train, the train speed, the loads from eachaxle and the axle spacings. This data of actual trainconfigurations and axle loads are portrayed as moving forcesand then used in computer simulations of trains crossing twodimensional simply supported bridges at constant speed. Onlysingle track short to medium span bridges are considered in thethesis. The studied load effect is the moment at mid-span. Fromthe computer simulations the moment history at mid-span isobtained.
The load effects are analysed by two methods, the first isthe classical extreme value theory where the load effect ismodelled by the family of distributions called the generalisedextreme value distribution (GEV). The other method adopts thepeaks-over-threshold method (POT) where the limiting family ofdistributions for the heights to peaks-over-threshold is theGeneralised Pareto Distribution (GPD). The two models aregenerally found to be a good representation of the data.
The load effects modelled by either the GEV or the GPD arethen incorporated into a reliability analysis in order to studythe possibility of raising allowable axle loads on existingSwedish railway bridges. The results of the reliabilityanalysis show that they are sensitive to the estimation of theshape parameter of the GEV or the GPD.
While the study is limited to the case of the ultimate limitstate where the effects of fatigue are not accounted for, thefindings show that for the studied cases an increase inallowable axle load to 25 tonnes would be acceptable even forbridges built to the standards of 1940 and designed to LoadModel A of that standard. Even an increase to both 27.5 and 30tonnes appears to be possible for certain cases. It is alsoobserved that the short span bridges ofapproximately fourmetres are the most susceptible to a proposed increase inpermissible axle load.
Keywords:bridge, rail, traffic load, load effect,dynamic amplification factor, extreme value theory,peaks-over-threshold, reliability theory, axle loads, fielddata.
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FERREIRA, MARCELO PIERI. "ESTIMATION OF THE SHORTAGE EFFECTS IN LOAD FORECASTING." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=4545@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOREsta dissertação investiga os efeitos do racionamento de energia elétrica ocorrido no período entre junho de 2001 a fevereiro de 2002, nas previsões de energia das principais concessionárias brasileiras. Para tal, estudamos o desempenho de modelos lineares e não-lineares. Dentre os modelos lineares, analisamos os modelos ARIMA (p,d,q) de Box & Jenkins e os modelos de amortecimento exponencial de Holt & Winters. Dentre os modelos não-lineares, são abordadas técnicas de inteligência artificial tais como Redes Neurais e Lógica Fuzzy. Visto que o racionamento levou a previsões ineficientes, propomos alternativas para reduzir seu impacto. Por último, investigamos os impactos causados pela crise energética nas previsões doze passos à frente de carga elétrica provenientes de vinte e oito concessionárias. A base de dados é composta pelos valores observados e as previsões fornecidas pelo PREVCAR, um dos sistemas de previsão da cadeia oficial de programas do setor elétrico brasileiro. Por meio de um procedimento de Análise de Agrupamento utilizando Redes Neurais Artificiais do tipo SOM (Self Organizing Map) de Kohonen são estabelecidos os grupos de concessionárias que possuem os mesmos comportamentos diante do racionamento. Como resultado final, foram estimados fatores de redução das previsões causados pelo racionamento, que servem como base de cálculo para reduções nas previsões futuras em períodos de crise de abastecimento.
This dissertation aims at an exploratory study of impacts caused by the 2001 energy crisis on the current forecasts produced on a monthly basis for main distributing utilities. For that we show an accuracy study of the performance of the linear and non-linear models. It has been used, within the linear models class, the modeling approach of Box-Jenkins and exponential smoothing of Holt- Winters. Within the non-linear ones, it was chosen those based on artificial intelligence techniques, such as Fuzzy Logic and Artificial Neural Network. Due to the lack of accuracy of the models to cope with the discontinuities provoked by the crisis on the forecasts, some alternative tools to reduce the impact on the forecast errors are proposed. Finally, the impacts caused by the crisis on multiple steps ahead forecasts have also been investigated. It was taken the monthly forecasts produced by PREVCAR (one of official Brazilian load forecasting system), as well as the observed values covering the same period, to create the crisis response indices series for each one of the twenty and eight utilities included in the analysis. It was also used the well-known neural network based algorithm SOM (Self Organizing Maps) to classify the utilities into homogeneous groups, according to their response to the energy crisis. As a final result, for each group, it was estimated the reduction factors that can be used as a prior information in future energy supply crisis.
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Augurelle, Anne-Sophie. "Feedback and feedforward processes underlying grip-load force coupling during cyclic arm movements." Université catholique de Louvain, 2003. http://edoc.bib.ucl.ac.be:81/ETD-db/collection/available/BelnUcetd-06292007-114349/.
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During transport of hand-held objects, the grip force is modulated in parallel with the load force changes. The control scheme underlying this grip-load force coupling involves subtle interplay between feedforward and feedback mechanisms. Based on internal models of the motor system and object properties, the load force can be predicted and the GF motor command can be specified in a feedforward manner. Moreover, during the course of arm movement, the CNS is informed by sensory feedback about mechanical events such as the lift-off of the object, slippage or excessive grip force. This information is used to correct the motor commands and to update the internal model of the motor apparatus and object. In this thesis, three experiments were conducted to examine the relative contributions of sensory-driven and anticipatory control of GF adjustments during cyclic vertical movement with a hand-held load. The main point was to assess whether internal models underlying the grip-load force coupling are robust when the environmental context was changed or when the sensory feedback was suppressed. Two experiments in parabolic flight were conducted to study the effects of a change in gravity on the dynamics of prehension. The main perturbation was that the novice subjects applied unnecessarily high safety margins during their first trial at 0 and 1.8 g in order to secure the grasp insofar as the gravitational component of the load force was unpredictable. By contrast, the temporal coupling between GF and LF was maintained regardless of the gravity conditions because the inertial component of the load could be still predicted from the arm motor command (efference copy). In the second study performed during parabolic flight, we have observed that the subjects were able to exert the same grip force for equivalent load generated either by a change of mass, gravity or acceleration despite the fact that it requires different arm motor commands. These two experiments brought further evidence that the predictive mechanisms largely contribute to the GF adjustment. Static forces such gravity are taken into account in the motor plan allowing adequate motor command and precise prediction of the incoming load force change. The GF output would depend on the precision of this prediction that can be evaluatedonly after the movement onset through sensory information about the actual state of the system. The third experiment performed in this thesis studied the role of cutaneous afferents in object manipulation by anesthetizing the thumb and index finger. In addition to their phasic slip-detection function, the cutaneous afferents are required for setting the background level of the grip force. Actually, in absence of tactile feedback, the temporal coupling between the grip and load forces is maintained but the mean magnitude of GF progressively decreases leading to object slipping. It is hypothesized that accumulating error occurred in the LF prediction leading to inadequate level of GF. Cutaneous afferents are thus required to correct and maintain the internal model of the arm-hand object system.
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Varekamp, Charlene Ghislaine. "Internal and external load measures as predictors of overuse injury risk in professional football players." Master's thesis, Faculty of Health Sciences, 2018. http://hdl.handle.net/11427/30044.
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Background
Football is the most popular sport worldwide. Football has grown into a faster, intensive and
more competitive game with a substantial increase in technical and physical demands. To reach
the peak demands of match play, extensive training is necessary to improve performance and to
reach the top level in professional football. Inadequate training loads prevent optimal
performance adaptions, place the player at higher risk of being underprepared and may increase
the risk of overuse injuries. Determining an optimal training load that improves performance and
decreases the risk of overuse injuries is important. Therefore, monitoring and understanding
individual responses to training loads are necessary. To date there is limited research regarding
prediction of risk of overuse injuries with respect to optimal TL in professional football players.
Aim
To describe the pattern of injuries and determine the influence of load metrics and injury risk in
South African professional football. The total GPS distance covered, the number of GPS
measured high-intensity sprints and session Rating Perceived Exertion load and the effects on the
risk of developing an overuse injury in professional football players.
Objectives
(1) To determine the relationship between total GPS distance (m) covered, ACWLR and overuse
injuries in a full competitive season. (2) To determine the relationship between GPS measured
high-intensity sprints, ACWLR and overuse injuries in a full competitive season. (3) To
determine the relationship between session rating of perceived exertion, ACWLR and overuse
injuries in a full competitive season. (4) To determine the overuse injury risk per playing position
(defenders, midfielders and attackers). (5) To determine the patterns of injury during a full
competitive season. (6) To determine the effect of the internal load (sRPE) and external load
(GPS) in a congestion week compared to a normal week on overuse injury risk.
Methods
Data was collected from 32 professional football players in the first and reserve team over one
full competitive Premier Soccer League season (2016/17). Training load metrics were assessed
using the acute:chronic workload ratio (ACWLR) to predict overuse injury risk within the team.
The relationship between total GPS distance (m) covered (TDC), GPS measured high-intensity
sprints (HIS), session rating of perceived exertion (sRPE) and ACWLR and overuse injuries was
determined. Overuse injuries were described based on frequency, anatomical position and injury
type as well as with regards to playing position (defenders, midfielders and attackers). The effect
of a congestion week on overuse injury risk was also determined.
Results
No significant outcomes were recorded when predicting overuse injuries for the whole team,
with regards to average TDC, HIS and sRPE ACWLR. Overuse injuries may be predicted when
monitoring the individual player loads, thereby taking into account the peak demands of match
play per playing position. Large difference between TDC and HIS and large increases or
decreases (20%) within weeks may increase the risk of overuse injuries. Hamstrings and groins
injuries are the most common injuries sustained and defenders sustained the most overuse
injuries within the team relative to exposure time. Congestion weeks did not predict overuse
injury risk.
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Fridell, Anna, and Hanna Josefsson. "The influence of seating load on internal and marginal fit of a fixed dental prosthesis." Thesis, Malmö högskola, Odontologiska fakulteten (OD), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-19974.
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Syfte: Syftet med studien var att undersöka hur olika axiala tryck och skjuvkrafter påverkade marginal och intern passform i en sexledsbro i titan i överkäkens frontregion.Material och metod: En litteratursökning gjordes för att insamla bakgrundsmaterial. Stödtänderna 13 12 11 21 22 23 preparerades på en plastmodell för en sexledsbro och en anatomiskt utformad bro i titan framställdes med hjälp CAD/CAM. En mastermodell av stödtänderna tillverkades i epoxyresin. Genom att använda replikateknik utvärderades brons passform vid olika cementeringstryck; 20, 35, 50, 70 N och 50 N med skjuvkrafter. Varje replika snittades med hjälp av en ”jig” och cementspalten analyserades i ett mikroskop. All data granskades statistiskt.Resultat: Resultatet visade att ett tryck med 20 N generellt gav en ej acceptabel passform och ett tryck med 35 N hade en stor spridning. Vid tryck med 50 N kunde mindre cementspalter ses. De blev inte mindre vid test med 70 N. När skjuvkrafter adderades försämrades resultaten jämfört med försöken med 50 N och 70 N.Konklusion: Ett tryck vid cementering som överstiger 50 N förbättrar ej passformen markant. Närvaro av skjuvkrafter påverkar passformen negativt. Ett lägre tryck på 20 N ger dock en mindre fördelaktig passform jämfört med skjuvkrafter förutsatt att ett tillräckligt högt tryck används. Alla slutsatser var statistiskt signifikanta.Purpose: The purpose of this study is to investigate how different axial seating loads and shear loads influences the marginal and internal fit of a titanium six unit FDP in the upper jaw frontal region.Materials and Methods: A literature search was made to acquire background material. Preparations of abutment teeth for a six unit FDP 13 12 11 21 22 23 were made on plastic teeth, and an anatomically designed titanium FDP was constructed using CAD/CAM. A master cast of the abutment teeth was fabricated in epoxy resin. Using the impression replica technique the fit of the FDP was evaluated by different seating loads during cementation; 20, 35, 50, 70 N and 50 N under the presence of shear loads. The replicas were sectioned using a jig and the cement gap was analysed using a microscope. All the data were statistically analysed.Results: The results showed that a seating load of 20 N generally gave an unacceptable fit and that the seating load of 35 N had great range. At seating loads of 50 N less cement gaps could be seen, i.e. more favourable fit. These results did not improve when testing with 70 N. With a presence of shear loads the results were poorer than when testing with 50 and 70 N.Conclusions: A seating load exceeding 50 N during cementation does not markedly give a more favourable fit. The presence of shear loads affects the fit negatively. A lower seating load of 20 N gives a less favourable fit compared to shear loads provided that a seating load high enough is used. All of these conclusions were statistically significant.
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Whittaker, William Rodney. "Internal migration in Great Britain : Causes and Effects." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.499897.
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URAO, Akira, and Kazuhisa MIWA. "EFFECTS OF COGNITIVE LOAD IN COMPUTER-BASED LEARNING ENVIRONMENTS." INTELLIGENT MEDIA INTEGRATION NAGOYA UNIVERSITY / COE, 2006. http://hdl.handle.net/2237/10472.
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Ross, Patricia. "Electrophysiology of working memory, task modality and load effects." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ51224.pdf.
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Guduru, Manish Reddy. "Investigating the effects of load on the XIFI node." Thesis, Blekinge Tekniska Högskola, Institutionen för kommunikationssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-10862.
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Having a good understanding of the load requirements in the datacenter improves the capability to effectively provision the resources available to the meet the demands and objectives of application services. Especially in a large project like XIFI this aspect becomes even more critical because of the limited availability of the resources and the complexity of the various entities present.In this study we frame a structure that provides deep insights to comprehend XIFI infrastructure. Further, we model the user requests that approach the node for resource allocation to run their applications. We aim to provide an understanding on different aspects involved in modelling. The objective of this present study is to investigate the effect of load on the XIFI node. To achieve this objective, we model the XIFI node by examining the various entities involved in it. Furthermore, we provide an overview about what constitutes as load in the XIFI node.We conduct a detailed specifications study after which we identify the imperative entities required for the modelling of both the XIFI node and the requests. We examine the model by simulating it in CloudSim for two different scenarios varying the specifications.We simulated the designed structure for 30 iterations and analyzed 10,000 user requests for two cases where total RAM of the node is increased in the second case when compared to the first case. We analyze the CPU usage, RAM usage, Bandwidth usage and Storage usage in both the cases and examine the effects of the user requests on each one of them.The results provided evidence that the load indices on the host are dependent on each other. Also, it showed that the request modelling had an impact on the load of the host. It can also be concluded that the resource provisioning can be effective if the user behavior is known.
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Tabarra, M. "Load factor effects on thermally stratified solar storage tanks." Thesis, De Montfort University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356458.
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Angeles, Antolin Linan Maria. "Effects of load modelling on Voltage Impasse Regions (VIR)." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254416.
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Voltage Impasse Region (VIR) is a phenomenon in power systemswhose dynamics are describe by a set of Differential AlgebraicEquations (DAE). VIR denotes a state-space area where voltagecausality is lost, i.e. the Jacobian of the algebraic part of DAEis singular. In a Time Domain Simulation (TDS) once system trajectoriesenter VIR, TDS experiences non-convergence of the solution.Then, there is no reason to continue with the simulation. Thisis why it is important to understand the mechanisms that introduceVIR. It is known that VIR appears in relation to static, non-linearload models. However, it remained unknown what the cumulativeeffect of several static, non-linear loads would be.This master thesis has further expanded the concept of VIRby carrying out a structured study on how the load modelling affectsVIR. For this purpose, this thesis proposes a quasi-dynamicmethodology to map VIR in the relative rotor angle space. Themethodology introduces a new discrete index called Voltage ImpasseRegion Flag (VIRflag), which allows to determine if the algebraicequations of DAE are solvable or not and, thus, to locate VIR.A test system is used to test the proposed quasi-dynamic approach.The VIRflag was first used to map VIR for various load combinations.Then, the relationship between TDS non-convergence issuesand the intersection of a trajectory with VIR is examined toverify the proposed methodology.The proposed method has been proved to be efficient in the determinationof VIR regardless of the number of non-linear loads inthe power system. Among the static exponential load models, theConstant Power (CP) load component has been identified as theone with the largest influence on VIR appearance and shape. TheConstant Current (CC) loads induce ”smaller" VIR areas and theConstant Impedance (CI) load can only alter the shape of VIR inthe presence of non-linear load models.VIR (Voltage Impasse Regions) är ett fenomen i kraftsystem varsdynamiska förlöp beskrivs av differential-algebraiska ekvationer(DAE). VIR betecknar ett område i tillståndsrummet där går förlorad,dvs Jakobianen av den algebraiska delen av DAE är singulärI tidsdomän-simuleringar (TDS) när en trajektoria träffar VIR,konvergerar TDS inte till en lösning. Då finns ingen anledning attfortsätta med simuleringen. Därför är det viktigt att förstå mekanismernasom introducerar VIR. Det är känt att VIR är relateradetill statiska, icke-linjära lastmodeller. Det var dock okänt vadden kumulativa effekten av flera statiska, icke-linjära belastningarskulle vara.Denna uppsats har vidareutvecklat begreppet VIR genom attgenomföra en strukturerad studie om hur lastmodellering påverkarVIR. För detta ändamål föreslår denna avhandling en kvasidynamiskmetod för att kartlägga VIR i det relativa rotorvinkelrummet.Metoden introducerar ett nytt diskret index som heterVoltage Impasse Region Flag (VIRflag), vilket gör det möjligt attbestämma om den algebraiska delen av DAE är lösbar eller inteoch därmed lokalisera VIR. Ett används för att testa det föreslagnakvasi-dynamiska tillvägagångssättet. VIRflag användes först för attkartlägga VIR för olika belastningskombinationer. Därefter granskasförhållandet mellan konvergensproblem i TDS och korsningenmellan en trajektoria och VIR för att verifiera den föreslagna metoden.Den föreslagna metoden har visat sig vara effektiv vid bestämningav VIR, oberoende av antalet icke-linjära belastningar. Bland destatiska exponentiella belastningsmodellerna har konstanteffektlast(CP) haridentifierats som den som har störst inflytande påVIR;s form. Den konstantströmlasten (CC) inducerar mindre"VIRområdenoch konstantimpedanslasten (CI) kan endast ändra formenav VIR i närvaro av icke-linjära belastningsmodeller.
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ARAUJO, THIAGO GOMES DE. "ADJUSTING LOAD SERIES BY THE CALENDAR AND TEMPERATURE EFFECTS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23850@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
O objetivo do presente trabalho é a geração de uma série mensal de carga elétrica livre das variações de calendário e de temperatura. Para tal, foram comparadas duas abordagens, uma totalmente empírica e outra híbrida com métodos empíricos e modelagens de regressão dinâmica, para identificar a mais adequada para a retirada desses ofensores. Os dados utilizados são provenientes de observações diárias de cada um dos quatro subsistemas que integram o Sistema Interligado Nacional (SIN), porém a ideia é produzir séries mensais do SIN e não apenas de cada um dos subsistemas. A série trimestral do PIB foi utilizada para decidir qual abordagem melhor ajustou os dados de Carga. A série mensal de carga ajustada do SIN será utilizada para subsidiar decisões, de compra e venda de energia nos leilões, das empresas distribuidoras de energia elétrica.
This thesis proposes a method to generate monthly load series free of variations coming from two sources: calendar and temperature. Two approaches were considered, one totally empirical and another one called hybrid, as it use empirical procedure to remove the calendar effect and a dynamic regression type of model to remove the temperature effects. The data set used comes found to daily observations from each one of the four subsystems that form the SIN (Brazilian Integrated Grid). However the final task is to obtain a unique monthly series for the SIN and not only the four subsystems monthly series. The quarterly PIB series was used to check the performance of the two proposed methods. Such adjusted series are quite important tools to hold on the decision of acquisitions and dailes of energy in the energy audits.
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Kai, Lauren C. (Lauren Catherine). "Effects of varying inertial load on human wrist movement." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32938.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.Includes bibliographical references (p. 44).
To study natural wrist movements in human subjects, a magnetic motion sensing system was employed to document unimpeded motion. Three identical bottles of different weights were designed as handles to provide a wide range of inertial loads. Subjects executed a series of horizontal and vertical moves with each bottle at two different speeds. Hypotheses concerning the effects of increased load on target overshoot, maximum acceleration and speed, and hand tremors were tested. The frequency content seen in the natural speed trials was found to resemble a normal distribution. This higher area of frequency content could potentially correlate with the frequency of hand tremors. After analysis of overshoot, there was found to be no statistical difference in the percent overshoot of movements by varying the weight of the handles. The data showed that the highest accelerations and speeds of the empty bottle were faster than those of the medium weight or the heavy weight bottle. One possible interpretation of this is that human wrist movement is force limited and there is a maximum acceleration at which humans can move.
by Lauren C. Kai.
S.B.
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Rajendar, Ashok. "Internal flow effects on performance of combustion powered actuators." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42901.
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Earlier investigations of Combustion Powered Actuation (COMPACT) have demonstrated its utility for high-speed aerodynamic flow control. In this actuation approach, momentary (pulsed) actuation jets are produced by the ignition of a mixture of gaseous fuel and oxidizer within a cubic-centimeter scale chamber. The combustion process yields a high pressure burst and the ejection of a high-speed exhaust jet. The present thesis focuses on characterization of the effects of the internal flow (which is altered through the fuel and oxidizer inlet streams) on mixing and flame propagation within the actuator's combustion chamber, and thereby on actuator operation and performance. A test chamber with a grid of interchangeable air and fuel inlets was used for parametric investigations of the effects of inlet size and location. Actuator performance is characterized using dynamic pressure measurements and phase-locked Particle Image Velocimetry (PIV) of the combustor's internal flow field in the presence and absence of the active combustion process. Over the range tested, increased momentum of the air inlet jet for a given flow rate improves the actuator performance by increasing bulk velocities and small-scale motions within the chamber, thus yielding net higher flame propagation speed and subsequently faster pressure rise and higher pressure peak. Variation in inlet location that results in swirling flow within the chamber yields higher internal pressures while air flow over the spark ignition site yields lower internal pressures and erratic combustion. Improved refill and combustion processes will lead to enhanced performance combustor designs.
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Shaw, Aaron Robert James. "Sleep, anxiety and the effects on cognition." Thesis, University of Warwick, 2018. http://wrap.warwick.ac.uk/114458/.
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Poor sleep and high levels of anxiety have a detrimental effect on cognitive functioning. However, very little is known about what cognitive functions are affected by poor sleep or high levels of anxiety and if some are more affected than others. This thesis informs the understanding of poor sleep and anxiety with a focus on generalised anxiety disorder and how they affect specific cognitive functioning namely Attention and Working Memory. Chapter one is a systematic literature review of the qualitative research exploring how sleep deprivation impacts on the cognitive functioning of people with Autistic Spectrum Conditions (ASC) and the principal challenges associated with trying to study the impact of sleep deprivation in people with ASC. Following both database and manual searches, fifteen studies were included and reviewed. The review highlights the suggestions that poor sleep has a detrimental effect on the cognitive functioning of people with ASC. Also, the use of objective and subjective measures of sleep was discussed to help in the early detection of these problems and considerations of carers and families was reviewed. Future research/clinical implications are discussed. Chapter two is a quantitative research study that investigated the combined effects of GAD and poor sleep on Attention and Working Memory. Sleep quality and quantity were assessed using subjective and objective measures of sleep. Attention and Working Memory was measured using various neuropsychological measures. Groups were compared for differences in cognitive scores using a non-parametric test. Relationships between GAD-7 scores, sleep quality/quantity and cognition scores were investigated using correlation analyses. Implications for future research and clinical implications are discussed. Chapter three is a reflective account, exploring the role of reflexivity in personal and professional development during the research process.
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Meyer-Scherf, Ronald [Verfasser], and Thomas [Akademischer Betreuer] Böllinghaus. "The pressure resistance of hollow glass fibers at internal pressure load / Ronald Meyer-Scherf. Betreuer: Thomas Böllinghaus." Magdeburg : Universitätsbibliothek, 2015. http://d-nb.info/1082625795/34.
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Frain, Jennie. "The effects of mechanical load on human intervertebral disc cells." Thesis, University of Manchester, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493463.
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The precise mechanisms by which human intervertebral discs (IVD) respond to load remains unknown and are a challenge to investigate in vitro. In this study, a novel mechanical loading system was devised, built, tested and successfully used to apply hydrostatic pressure to nucleus pulposus (NP) and annulus fibrosis (AF) cells and explants obtained from human nondegenerate and degenerate IVD. Cells were removed from the IVD, cultured in monolayer to generate sufficient numbers and subsequently embedded in alginate constructs prior to application of dynamic cyclic hydrostatic pressure at physiological levels.
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Mohammed, Abdul Waheed. "Effects of Axial Component of Prestress in Load Balancing Method." OpenSIUC, 2012. https://opensiuc.lib.siu.edu/theses/802.
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Post-Tensioned concrete structures can be analyzed using different methods. One of these methods is the load balancing method introduced by T. Y. Lin. This method, unlike conventional stress methods, assumes pre-stress as a form of loading that counteracts the dead loads, live loads and service loads. Basically, the prestressing force is resolved into vertical and horizontal components and then the structure is analyzed as an ordinary loaded structure. The aim of this study is to investigate the effect of horizontal component of prestressing force in frames of different lengths. The horizontal component in beam-like structures will not affect the vertical reactions of the supports or bending moments of the beam. However, neglecting this component in frames can cause significant difference in the actual results. SAP2000 was used to analyze the frames by applying prestress forces directly and then by using balancing loads with and without considering the horizontal component of the prestressing force.
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Iribe, Gentaro. "Effects of mechanical load on calcium handling in cardiac myocytes." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487260.
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In the 'in sitrl heart, electrical excitation of cardiac myocytes induces Ca2+ influx into the cytosolic space, which initiates muscle contraction (excitation contraction coupling) against a background of dynamically changing pre- and afterload conditions. On the other hand, mechanical load affects Ca2+ handling, either directly, or indirectly via modulation of electrical activity (mechano-electric feedback). The aim of this Thesis is to investigate and quantitatively describe the interactions between mechanical activity and Ca2+ handling, using experimental and mathematical modelling tools. Although there are a number of mathematical cardiac cell models available, few are aimed at reproducing beat-by-beat behaviour of Ca2+ handling. Therefore, we developed an original cell model which allows one to reproduce beat-by-beat changes in Ca2+ handling and resultant force production, which formed the basis for mathematical integration of the experimental findings of our Ca2+ handling study in this thesis. For e};perimental research, we developed a novel single cell force-length clamp (MyoStretcher), which uses piezo-control of carbon fibres (CF) to dynamically restrain the mechanical environment of isolated intact cardiomyocytes.Using the M):oStretcher, we subjected single isolated myocardial cells to dynamic contractions with work-loop style force-length (FL) relation, similar to those experienced by the cell 'in sittl. Single cell mechanics studies revealed that the end-systolic FL relation (ESFLR) IS load-independent In ventricular cardiomyoeytes of small mammals (Guinea pig). Modelling-based simulation studies suggest that the load-independent behaviour of ESFLR is the result of the combined effects ofload-dependent Ca2+ and crossbridge kinetics. Furthermore, the impact of diastolic stretch on sarcoplasmic reticulum (SR) Ca2+ handling was investigated. Axial cell stretch increased SR Ca2+ leak, but also and re-uptake of Ca2+ into the previously depleted SR of ventricular cardiomyocytes isolated from Guinea pig. The results were reproduced in model simulations. Axial stretch furthermore caused an acute increase in the Ca2+ spark rate of rat myoeytes. The mechanisms underlying this stretch-induced increase in spark rate act locally, are independent of nitric oxide and stretch-activated ion channels, and require an intact cytoskeleton. In conclusion, this thesis revealed that the interaction between cellular mechanics and Ca2+ handling is an important factor for integrative function of the heart, established several hitherto unknown mechanisms, and provided a novel set of experimental and theoretical tools for further research.
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Schmidt, Daniel. "The Effects of Cognitive Load and Stereotyped Groups on Punitiveness." Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/cmc_theses/1438.
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The current study explores the interactions of cognitive load and stereotypes on emotions felt toward stereotyped groups and decisions of punitiveness for a crime. Dual processing models suggest that cognitive load can decrease deliberation and increase intuitive and emotional judgments. The Stereotype Content Model suggests that different stereotyped groups evoke different emotions. The current study tested the hypothesis that individuals under high cognitive load will be more likely to rely on stereotypical information and associated emotions when making decisions on punishment for a crime. Study 1 had 205 participants from Amazon’s Mechanical Turk website complete an online survey in which they read a vignette about an elderly man, a man who receives welfare checks, or a neutrally described man, who commits a “hit and run” crime. Half of the participants were then put under cognitive load, and all participants completed questions on punitiveness for the character’s crime, emotions felt towards the character, and perceptions of warmth and competence in the character. Study 2 repeated the manipulations and measures of study 1 with a few changes and in a college lab setting. Results were inconclusive in both studies and the null hypothesis was retained. Methodological and theoretical reasons for these results are discussed.
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Lynch, Erin E. "Effects of Perceptual Load on Dichotic and Diotic Listening Performance." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1627041542562664.
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Lynch, Erin E. "Effects of Perceptual Load on Dichotic and Diotic Listening Performance." Ohio University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1627041542562664.
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Flodgren, Gerd. "Effects of low-load repetitive work and mental load on sensitising substances and metabolism in the trapezius muscle." Doctoral thesis, Umeå : Idrottsmedicin Sports Medicine, Rehabiliteringsmedicin Rehabilitation Medicine, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1393.
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Jedenius, Arthur. "Internal Erosion and Dam Stability : Analysis of the internal erosion effects on stability of an embankment dam." Thesis, Luleå tekniska universitet, Geoteknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68551.
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Embankment dams encounter several problems in terms of dam safety. One of those problems is called internal erosion. This phenomenon is induced by the movement of fine particles within the dam due to seepage forces. If the dam is not able to self-heal, the eroded zones will increase which will eventually cause the dam to fail. Thus standards have been created by Svensk Energi and summarized in the Swedish dam safety guideline RIDAS 2012. These standards are used as a basic in the risk analysis of existing dams and provide guidelines for proper design of future dams.A dam in Sweden has presented recurring incidents related to internal erosion within the core. The impact of this internal erosion is analysed in this thesis with the use of Finite Element Method/Analysis (FEM/A). FEA models simulate the in situ stresses in the dam and calculate the strength. It also enables the analysis of changing hydraulic conductivity and its effect on the overall effective strength due to changing pore pressure and seepage forces. The analysis using numerical methods was performed in the program PLAXIS2D and SEEP/W while limit equilibrium analysis was done in SLOPE/W.The calculation in PLAXIS2D was performed by using the Mohr-Coulomb constitutive model. The in situ stresses are initially calculated using gravity loading since this is the preferred method on an uneven terrain instead of a K0-calculation. Then, through a set of phases in the program, zones where erosion is assumed to have occurred are changed. These zones have a higher permeability and will thus affect the pore pressures in the dam following Darcy’s law with permeability through a set medium.The increased permeability is set to follow an increased void ratio due to loss of fine material in the core. How this increase of void ratio affects the permeability is investigated through using Ren et al’s (2016) proposed equation for calculating permeability with a set void ratio. Their equation, apart from the usually used Kozeny-Carman equation, considers both effective and ineffective void ratio where the ineffective void ratios refers to the volume of pores that is immobile when flow is considered.The increased flow in the eroded zones of the core did not seem to impact the strength of the dam in much regard. The phreatic surface and thus the pore pressure did not change enough to influence the overall effective strength of the dam. It raises the question if the stability of an earth-rock fill dam will be affected due to increased pore pressure at all due to its draining properties and if it would rather fail due to increased seepage forces.
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Middleton, Mark Gerald. "Community social status effects on migration outcomes." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10143.
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Robinson, Tim T. "An investigation of the organizational effects of internal participatory evaluation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ28372.pdf.
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Sprot, Adam Joseph. "Open-wheel aerodynamics : effects of tyre deformation and internal flow." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/7292/.
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Competitive performance of an F1 race car relies upon a well designed and highly developed aerodynamic system. In order to achieve this, total understanding of the downstream wake of exposed rotating wheels is essential. Components such as bargeboards and indeed much of the front wing are developed to provide pressure gradients and vortex structures to influence the wheel wake, ensuring high energy mass-flow to the sensitive leading edge of the underfloor and eventually the rear wing. Wind tunnel testing of model-scale deformable tyres has become a common occurrence in F1 in recent years although there is a significant lack of available literature, academic or otherwise, as to their use. This work has studied in detail the aerodynamic consequences which occur from the varying sidewall bulge and contact patch region making use of several techniques. These include scanning rotating tyre profiles under load, static contact patch size measurements, five-hole pressure probe wake measurements, particle image velocimetry (PIV) and load-cell drag measurements. CFD simulations utilising two industrial codes have also been performed to support the experimental work. Coordinates representing tyre profiles under a range of on-track conditions are available for other researchers to use as a basis for CFD studies. The work presented here includes a full range of representative on-track axle heights which far exceed the more conservative range usually tested in an industrial setting for longevity reasons. The most sensitive parameters for aerodynamic testing of wheels have been identified. For development of a full car, in decreasing order of priority, the following must be correctly matched to the realistic scenario: axle height, yaw condition (without glycerol - often used to reduce friction at the expense of a compromised tyre profile), camber angle, detailed internals, high inflation pressure, through-hub flow rate and least significantly the rotation of the internal brake rotor. The study of through-hub flows revealed that the external aerodynamic effect of the brake scoop inlet varies significantly with the amount of internal restriction. The pumping effect of the brake rotor was measured to be negligible compared to the restrictive effect of its internal passages and that leads to an effect known as inlet spillage with a negative cooling drag trend, whereby the drag of the wheel assembly decreases with increased through-hub flow.
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De, Luca Antonio. "Behavior of Full-Scale Reinforced Concrete Members with External Confinement or Internal Composite Reinforcement under Pure Axial Load." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/348.
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The need to satisfy aerospace industry's demand not met by traditional materials motivated researchers and scientists to look for new solutions. The answer was found in developing new material systems by combining together two or more constituents. Composites, also known as fiber reinforced polymers (FRP) consisting of a reinforcing phase (fibers) embedded into a matrix (polymer), offered several advantages with respect to conventional materials. High specific modulus and strength together with other beneficial properties, corrosion resistance and transparency to electrical and magnetic fields above all, made FRP also suitable for use as construction materials in structural engineering. In the early years of the twenty-first century, the publication by the American Concrete Institute (ACI) of design guidelines for the use of FRP as internal reinforcement and for external strengthening of concrete members accelerated their implementation for structural engineering applications. To date, FRP have gained full acceptance as advanced materials for construction and their use is poised to become as routine as the use of conventional structural materials such as masonry, wood, steel, and concrete. However, new concrete columns internally reinforced with FRP bars and FRP confinement for existing prismatic reinforced concrete (RC) columns have currently important unsolved issues, some of which are addressed in this dissertation defense. The dissertation is articulated on three studies. The first study (Study 1) focuses on RC columns internally reinforced with glass FRP (GFRP) bars; the second (Study 2) on RC prismatic columns externally confined by means of FRP laminates using glass and glass/basalt fibers; and the third (Study 3) is a theoretical attempt to interpret and capture the mechanics of the external FRP confinement of square RC columns. Study 1 describes an experimental campaign on full-scale GFRP RC columns under pure axial load undertaken using specimens with a 24 by 24 in. (0.61 by 0.61 m) square cross section. The study was conducted to investigate whether the compressive behavior of longitudinal GFRP bars impacts the column performance, and to understand the contribution of GFRP ties to the confinement of the concrete core, and to prevent instability of the longitudinal reinforcement. The results showed that the GFRP RC specimens behaved similarly to the steel RC counterpart, while the spacing of the ties strongly influenced the failure mode. Study 2 presents a pilot research that includes laboratory testing of full-scale square and rectangular RC columns externally confined with glass and basalt-glass FRP laminates and subjected to pure axial load. Specimens that are representative of full-scale building columns were designed according to a dated ACI 318 code (i.e., prior to 1970) for gravity loads only. The study was conducted to investigate how the external confinement affects ultimate axial strength and deformation of a prismatic RC column. The results showed that the FRP confinement increases concrete axial strength, but it is more effective in enhancing concrete strain capacity. The discussion of the results includes a comparison with the values obtained using existing constitutive models. Study 3 proposes a new theoretical framework to interpret and capture the physics of the FRP confinement of square RC columns subjected to pure compressive loads. The geometrical, physical and mechanical parameters governing the problem are analyzed and discussed. A single-parameter methodology for predicting the axial stress - axial strain curve for FRP-confined square RC columns is described. Fundamentals, basic assumptions and limitations are discussed. A simple design example is also presented.
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Albring, Susan M. "The effects of the cost of foreign internal funds on firms' financing choice of debt vs. internal funding." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/289863.
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This paper examines how the multinational firm's choice of debt or internal funds as a method of financing depends upon the cost of using internal funds. I extend prior research by differentiating between the cost of using domestic versus foreign internal funds for additional investments for multinational enterprises. I predict that foreign funds are more costly than domestic funds because of potential differential costs, including repatriation tax costs and financial reporting costs. I find that my measure of total funds, the sum of cash and short-term receivables, is negatively related to issuing incremental debt. I also examine whether the proportion of total funds represented by foreign funds affects a firm's decision to use incremental debt financing. My proxy for foreign funds is a rough estimate using available Compustat data (foreign assets divided by total assets multiplied by total funds). I do not find significant results with this general measure of foreign funds. Additionally, I test whether firms' FTC positions affect incremental financing decisions. I do not find results with this measure of foreign funds. I further examine the impact of costly foreign funds on the incremental debt financing decision using alternative measures. I examine the differential costs of a subset of foreign funds with the designation and dollar level of permanently reinvested earnings. My results suggest that the change in debt is positively related to the dollar level of permanently reinvested earnings. In addition, in a model that includes the interaction between the dollar level of permanently reinvested earnings and non-binding FTC status, my results suggest that the magnitude of the relationship between the level of permanent reinvestment of foreign earnings and incremental debt financing is greater for firms with non-binding FTC limitations than for firms with binding FTC limitations. Overall, my findings suggest that the source of internal funds makes a difference in firms' use of debt financing. After controlling for investment opportunities with a measure of the difference between the foreign and domestic after-tax return, I find that financial reporting considerations impact the debt (versus internal funds) financing decision.
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Offerman, Jens. "Can internal and external load measures via Polar Vantage V predict training status in trained individuals? : - A prospective study during a normal and a heavy load training week." Thesis, Umeå universitet, Avdelningen för idrottsmedicin, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-163225.
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Purpose To evaluate the information provided by Polar Vantage V, a new generation of heart rate monitor/watch (HRM-watch) to the user, regarding the acute:chronic load ratio (ACLR), based onthe external and internal load measures and examine the measures against psychological and physiological measures before and during a threshold test with VO2max testing. Method A five-week prospective study with results and data collected during and after four normal training weeks and during a fifth week with a very high training load. The results from HRM-watchwere then evaluated against the results from physiological and psychological tests. Eight endurance runners were recruited. Results Differences in ACLR against the differences in HRR show a R2 value of 0.77 (p<0.05). ACLR signicantly increased with an average of 0.33 from 0.93 to 1.26 (p=0.003, 95 % CI= 0.17 {0.49). Differences in ACLR against dierences in total mood disturbance (TMD) from POMS showin regression analyses a R2value of 0.67 (p=0.05). No significant difference was noted in neither resting HRV (p=0.3, 95% CI= -22.2 { 8.5) or standing HRV (p=0.15, 95% CI= - 4.15 { 20.8). Conclusion Based on the result of the present study it can be concluded that training status, well-being and present mood state can be predicted fairly good with the information from the internal and external load measurements from the Polar Vantage V. However, the power of present exploratory study was low due to a low number of included participants. Future research with greater number of participants and an improved study design is needed to verify these interesting findings.
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Wright, Adam Thomas. "The effects of cytoskeletal disruption and mechanical load on cardiac conduction." Diss., [La Jolla] : University of California, San Diego, 2010. http://wwwlib.umi.com/cr/ucsd/fullcit?p3404478.
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Thesis (Ph. D.)--University of California, San Diego, 2010.Title from first page of PDF file (viewed June 10, 2010). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (leaves 110-122).
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Stephens, Marilee Jane. "The effects of load on normal, infant and Parkinsonian human gait." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0014/NQ59676.pdf.
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Chiesa, Luisa. "Mechanical and electromagnetic transverse load effects on superconducting niobium-tin performance." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53261.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 233-238).
Cable-in-Conduit Conductor is the typical geometry for the conductor employed in superconducting magnets for fusion applications. Once energized, the magnets produce an enormous electromagnetic force and very large transverse loads are applied against the strands. This large force results in a degradation of the performance of the superconducting magnets. In this thesis work transverse load experiments on sub-sized cables, have been designed to study the mechanical and electrical transverse load effects on superconducting cables. Two devices to apply external mechanical loads to a cable have been developed and several different size cables have been tested simulating the International Thermonuclear Experimental Reactor (ITER) Lorentz stress conditions. The first device was designed to use a circular turn sample of a 36-strand cable. Four samples were successfully tested with this device and significant degradations of the critical current due to the external transverse loads have been measured. However, all samples showed unexpectedly large initial degradations that made an analysis of transverse load effects of the samples difficult. The second device was developed for a hairpin configuration. Three different size cables of a single strand, a triplet and a 45-strand cable were systematically tested using this method. This hairpin sample device has successfully operated and provided very reliable experimental data. The experimental results were difficult to explain by existing theories.
(cont.) A new model based on contact mechanics concepts has been developed to determine the number of contacts and the effective contact pressure among the strands in a cable. The model was used to analyze and accurately calculate the displacements of a cable under transverse mechanical load, and it has evaluated the effective contact pressures between strands for the first time. The new model can explain the Lorentz force and contact pressure distribution effect on the critical current degradation of the tested samples. The 3-strand data and their critical current behavior as a function of the effective contact pressure were used to predict the test behavior of a 45-strand cable. It was also used to simulate the critical current degradations of various cables including ITER full size cables. The model has predicted an initial degradation of 20% for an ITER TF cable of 1152 strands at 68 kA operational current caused by the transverse Lorentz load effect only. Parametric studies of the model have indicated that the initial degradation could be reduced by shortening the twist pitch length of the initial stages of a full size cable or by mechanically supporting the last stage bundles of the cable. This thesis work shows for the first time, that the transverse Lorentz load effect, which is inherent in the CICC design, contributes a significant fraction of the degradation of a large Nb3Sn superconducting cable. The model quantifies the degradation and this information could be used in better estimating the appropriate margin requirements in magnet design.
by Luisa Chiesa.
Ph.D.
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Brown, Morgan E. "Effects of Age, Task Type, and Information Load on Discrimination Learning." TopSCHOLAR®, 2016. http://digitalcommons.wku.edu/theses/1648.
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The feature positive effect (FPE) is a phenomenon in discrimination learning by which learning occurs more quickly when the presence (Feature positive; FP), rather than absence (Feature negative; FN) of a stimulus indicates a response should be made. Although the FPE has been extensively corroborated, a reversal, or feature negative effect (FNE), has been found when a target stimulus comes from a smaller set of stimuli (Fiedler, Eckert, & Poysiak, 1988). Age differences in FP and FN learning indicate that older adults perform more poorly than young adults on both FP and FN tasks, and are likely related to decline in working memory (WM) throughout adulthood (Mutter, Haggbloom, Plumlee, & Schrimer, 2006). This study used a successive discrimination task to compare young and older adults’ performance across FP and FN conditions under low (three of a set of four stimuli were presented) and high (three of a set of six stimuli were presented) information load (IL). Results from rule articulation, final incorrect and 12 consecutive trials correct did not support the hypotheses, but trend analyses provided partial support. Under low IL, YA demonstrated a FN response bias whereas OA showed no bias. Under high IL, YA and OA demonstrated equivalent performance whether the target stimulus was present or absent in the FP condition. In the FN condition OA performed better when the target stimulus was absent while YA showed no bias. These findings indicate FN task performance varies by age and this variation changes based on IL condition.
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Zhou, Xiao Yi. "Statistical analysis of traffic loads and traffic load effects on bridges." Phd thesis, UNIVERSITE PARIS-EST, 2013. http://tel.archives-ouvertes.fr/tel-00949929.
Full textAbstract:
Une grande majorité (85%) des ponts français a une portée inférieure à 50 m. Pour ce type d’ouvrage d’art, la charge de trafic peut être déterminante pour la conception et le recalcul. Or, en Europe, le fret routier a augmenté de 36.2% entre 1995 et 2010, et la croissance annuelle du volume transporté par la route a été évaluée à 1.7% entre 2005 et 2030. Il est donc essentiel de s’assurer que les infrastructures européennes sont en mesure de répondre à cette demande croissante en capacité structurelle des ouvrages. Pour les ouvrages neufs, les modèles de trafic dans les normes ou les législations pour la conception des ponts incluent une marge de sécurité suffisante pour que la croissance du trafic soit prise en compte sans dommage par ces ouvrages. Mais pour les ouvrages existants, la résistance structurelle aux trafics actuels et futur est à vérifier et une priorisation des mesures doit être faite pour assurer leur intégrité structurelle et leur sécurité. De plus, afin de préserver leur infrastructure tout en ne menaçant pas leur compétitivité nationale, certains pays réfléchissent à l’introduction de poids lourds plus longs, plus lourds, ce qui permet de réduire le nombre de véhicules pour un volume ou un tonnage donné, ainsi que d’autres coûts (d’essence, de travail, ..), ce qui justifie encore plus les calculs effectués. Pour répondre à ce genre de problématique, différentes méthodes d’extrapolation ont déjà été utilisées pour modéliser les effets extrêmes du trafic, afin de déterminer les effets caractéristiques pour de grandes périodes de retour. Parmi celles-ci nous pouvons citer l’adaptation d’une gaussienne ou d’une loi de Gumbel sur la queue de distribution empirique, la formule de Rice appliquée à l’histogramme des dépassements de niveaux, la méthode des maxima par blocs ou celle des dépassements de seuils élevés. Les fondements et les utilisations faites de ces méthodes pour modéliser les effets extrêmes du trafic sur les ouvrages sont donnés dans un premier chapitre. De plus, une comparaison quantitative entre ces méthodes est réalisée. Deux études sont présentées, l’une basée sur un échantillon numérique et l’autre sur un échantillon réaliste d’effets du trafic. L’erreur induite par ces méthodes est évaluée à l’aide d’indicatifs statistiques simples, comme l’écart-type et les moindres carrés, évalués sur les valeurs caractéristiques et les probabilités de rupture. Nos conclusions sont, qu’en général, les méthodes sont moins précises lorsqu’il s’agit de déterminer des probabilités de rupture que lorsqu’elles cherchent des valeurs caractéristiques. Mais la raison peut en être les faibles probabilités recherchées (10-6 par an). De plus, bien qu’aucune méthode n’ait réalisée des extrapolations de manière correcte, les meilleures sont celles qui s’intéressent aux queues de probabilités, et en particulier des dépassements au-dessus d’un seuil élevé. Ainsi une étude de cette dernière méthode est réalisée : en effet, cette méthode, nommé "dépassements d’un seuil élevé", considère que les valeurs au-dessus d’un seuil correctement choisi, assez élevé, suit une distribution de Pareto généralisée (GPD). Cette méthode est utilisée de manière intensive dans les domaines de l’hydrologie et la finance, mais non encore appliquée dans le domaine des effets du trafic sur les ouvrages. Beaucoup de facteurs influencent le résultat lorsqu’on applique cette méthode, comme la quantité et la qualité des données à notre disposition, les critères utilisés pour déterminer les pics indépendants, l’estimation des paramètres et le choix du seuil. C’est pour cette raison qu’une étude et une comparaison des différentes méthodes d’estimation des paramètres de la distribution GPD sont effectuées : les conditions, hypothèses, avantages et inconvénients des différentes méthodes sont listés. Différentes méthodes sont ainsi étudiées, telles la méthode des moments (MM), la méthode des moments à poids (PWM), le maximum de vraisemblance (ML), le maximum de vraisemblance pénalisé (PML), le minimum de la densité de la divergence (MDPD), la méthode des fractiles empiriques (EPM), la statistique du maximum d’adaptation et la vraisemblance des moments (LM). Pour comparer ces méthodes, des échantillons numériques, des effets de trafic simulés par Monte Carlo et des effets mesurés sur un ouvrage réel sont utilisés. Comme prévu, les méthodes ont des performances différentes selon l’échantillon considéré. Néanmoins, pour des échantillons purement numériques, MM et PWM sont recommandées pour des distributions à paramètre de forme négatif et des échantillons de petite taille (moins de 200 valeurs). ML est conseillé pour des distributions à paramètre de forme positif. Pour des effets du trafic simulés, ML et PML donne des valeurs de retour plus correctes lorsque le nombre de valeurs au-dessus du seuil est supérieur à 100 ; dans le cas contraire, MM et PWM sont conseillés. De plus, comme c’est prouvé dans l’étude de valeurs réelles mesurées, les valeurs a priori aberrantes ("outliers") ont une influence notable sur le résultat et toutes les méthodes sont moins performantes. Comme cela a été montré dans la littérature, ces "outliers" proviennent souvent du mélange de deux distributions, qui peuvent être deux sous-populations. Dans le cas de l’effet du trafic sur les ouvrages, cela peut être la raison d’une estimation des paramètres non correcte. Les articles existant sur le sujet soulignent le fait que les effets du trafic sont dus à des chargements indépendants, qui correspondant au nombre de véhicules impliqués. Ils ne suivent pas la même distribution, ce qui contredit l’hypothèse classique en théorie des valeurs extrêmes que les événements doivent être indépendants et identiquement distribués. Des méthodes permettant de prendre en compte ce point et utilisant des distributions mélangées (exponentielles ou valeurs extrêmes généralisées) ont été proposées dans la littérature pour modéliser les effets du trafic. Nous proposons une méthode similaire, que nous appelons dépassement de seuils mélangés, afin de tenir des différentes distributions sous-jacentes dans l’échantillon tout en appliquant à chacune d’entre elles la méthode des dépassements de seuil. Pour des ponts ayant des portées supérieures à 50 m, le scénario déterminant est celui de la congestion, qui n’est pas ce qui est étudié ici. De plus, le trafic n’est pas la composante déterminante pour la conception des ponts de longue portée. Mais des problèmes de fatigue peuvent apparaître dans certains ponts, tels les ponts métalliques à dalle orthotrope, où l’étude du trafic peut devenir nécessaire. Ainsi nous avons fait une étude de l’influence de la position des véhicules sur le phénomène de fatigue. Pour cela, quatre fichiers de trafic réels, mesurés en 2010 et 2011 par quatre stations de pesage différentes, ont été utilisés. Ils ont mis à jour des comportements latéraux différents d’une station à l’autre. Si nous les appliquons au viaduc de Millau, qui est un pont métallique à haubans et à dalle orthotrope, nous voyons que l’histogramme des effets et l’effet de fatigue cumulé est beaucoup affecté par le comportement latéral des véhicules. Ainsi, des études approfondies utilisant les éléments finis pour modéliser les ouvrages et des enregistrements de trafic réel, peuvent être utilisées pour pré-déterminer quels éléments, donc quelles soudures, doivent être examinés dans les ponts afin d’estimer leur santé structurelle.
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Dahlgren, Emma. "Effects of Different Load Magnitudes on Longitudinal Growth of Immature Bones." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230885.
Full textAbstract:
In vivo studies of mechanical loading on bone have suggested that load magnitude is one of the parameters that play a vital role in bone adaptation. This study examined how longitudinal growth of immature rat metatarsals is affected by different load magnitudes. The main hypotheses were that the longitudinal growth of immature bone would decrease with increased compressive load magnitude, and that the longitudinal growth would be more decelerated the higher the load mag- nitude. The three middle metatarsal bones in the back paws of 19-20 days old Sprague-Dawley rat fetuses were extracted. Metatarsal bones were loaded with 0.05 N, 0.25 N, 1.25 N and 6.25 N. Loading rate and number of cycles were constant at 0.01 mm/sec and 10 cycles respectively. Length measurements occurred every 2-3 day. Concluded from the study was that a load magni- tude of 0.05 N resulted in an increased longitudinal growth, compared to unloaded bones. For the other load magnitudes the results were insufficient and inconsistent and therefore nothing could be suggested for them. The problem remained as before and further studies are needed.
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Blumer, Tyler D. "Carton Clamp Methodologies and the Effects on Load Containment and Retention." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1150.
Full textAbstract:
ABSTRACT
Carton Clamp Test Methodologies and the Effects on
Load Containment and Retention
Tyler Don Blumer
A carton clamp is an alternative device for moving packages and material. Instead of using iron tines like that of a conventional forklift, a carton clamp uses two large aluminum platens to slightly compress and secure the load for handling. This is advantageous as it allows operators to move layers of a unitized load individually, and eliminates the need for a pallet when handling full unitized loads. When using a carton clamp attachment, it is often difficult for operators to accurately gauge the amount of force being applied to the load. The required clamping force changes depending on the size, shape, and weight of the load. This creates the potential for under-clamping (slippage) and over-clamping (compressive damage). Seeing a market need for a reliable means of testing, two organizations set out to develop a testing protocol.
A rift formed between schools of thought regarding the correct testing procedure. ISTA provides a sterile, calculated, and stationary simulation of carton clamp handling in its ISTA 6-SAMS test protocol. ASTM offers a more holistic, dynamic, observational approach in its mobile ASTM 6055 standard protocol. One school of thought is suggested to imply that a package should be developed to be handled by the carton clamp (ASTM). The other school of thought is that the carton clamp attachment should be properly adjusted to the package specimen (ISTA).
Previous studies have been performed citing the ISTA standard and using a specialized carton clamping device vibration device that is calibrated for laboratory research. Arguably, this method, though repeatable in nature, does not accurately simulate carton clamp handling found in industry. Likewise, the equipment investment is cost prohibitive for those in industry wishing to duplicate such a study. ASTM uses a carton clamp truck as used in industry, but does not specify any specific parameters making repeatability between laboratories and practitioners ambiguous.
This study examined whether or not a common ground can be reached; implementing a carton clamp lift truck as found in industry allowing for mobile (hazard course) testing. A modified version of ISTA 3B will be paired off against ASTM 6055 for evaluating both column and cross stack pallet patterns with a variety of treatments. This study attempted to determine if carton clamps as found in industry are capable and repeatable enough to provide consistent data. Similarly, this study examined the test methodologies effect on load containment via stretch film force, load retention via unitized load slippage, and the effects of ride height and driver interaction. The study sought to understand if these effects are uniform across the unitized load, or if particular layers of the load more affected than others.
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Bialko, Christopher Stephen. "The Effects of Practice and Load on Actual and Imagined Action." Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1242884385.
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Ghahghaeinezamabadi, Saeideh. "The dynamics of attention in active reading and effects of load." Thesis, Goldsmiths College (University of London), 2013. http://research.gold.ac.uk/9697/.
Full textAbstract:
We investigated the dynamics of spatial attention in an active viewing task, namely reading, and the effects of the load of target words on these dynamics. We showed that, over the course of a fixation, attention was modulated by the load of the fixated word and the upcoming word. The load of words was manipulated by varying word frequency and the orthographic familiarity of the first trigram in words. In a variation of the dynamic-orienting paradigm (Fischer, 1999), participants read sentences or strings of words for the primary task and discriminated gaze-contingent probes - occurring with variable spatial and temporal offsets from the first fixations on words - for the secondary task. Reading was evidenced by longer fixation durations on words with lower frequencies. The accuracy of probe discrimination was used to index attention. Early in a fixation, attention was focused on the gaze more when the fixated word was lower in frequency. This early effect of frequency was revealed for reading sentences and strings of words provided words were previewed before being fixated. Attention defocused over time and, by halfway through a fixation, orienting towards the to-be-fixated location (i.e., towards the right) began. Late in a fixation, attention had oriented more to the right of the gaze for high- than low-frequency words. Shortly before the saccade to the upcoming word, and during preview of this word, its processing was sufficiently advanced to affect attention: specifically, less attention remained at the gaze location when the first trigram of the upcoming word was orthographically less familiar. In sum, we showed that the moment-to-moment processing load of words affects the dynamics of spatial attention.