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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 23 for “"shift factor"”.
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Utilization of Instrument Response of SuperPaveTM Mixes at the Virginia Smart Road to Calibrate Laboratory Developed Fatigue Equations
… typically accounted for by the use of a single shift factor based mainly on engineering experience. The flexible pavement portion of the Virginia Smart Road includes 12 different flexible pavement designs. Each section is approximately 100m long. The sections are instrumented with pressure …
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Rheology of molten polystyrene with dissolved gases
… decrease in viscosity. The composition-dependent shift factor scaling method, which is similar to classical viscoelastic scaling techniques (time-temperature superposition), was adopted in order to evaluate the effect of gas concentration on viscosity. The method successfully consolidates the …
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A finite element analysis of adhesively bonded composite joints including geometric nonlinearity, nonlinear viscoelasticity, moisture diffusion and delayed failure
… response is taken into account by a nonlinear shift factor definition. Penetrant sorption is accounted for by a nonlinear Fickean diffusion model in which the diffusion coefficient is dependent on the penetrant concentration and the dilatational strain. A delayed failure criterion based on the …
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Viscoelastic characterization of polyurea based polymers
… in the form of Prony series. The thermal shift factor for bulk relaxation was fitted with the Arrhenius equation while for shear relaxation, the trend was fitted with the WLF equation. The nonlinear response at ambient conditions was predicted using the modified free volume model (Park et …
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Development of tension and compression creep models for wood using the time-temperature superposition principle
… creep compliance for each temperature was shifted along the log-time axis to obtain a "master" curve that describes the creep response of the specimens. All compliance curves also required vertical shifting. The experimental horizontal shift factors followed the Arrhenius formulation that …
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Formation of microfibers and nanofibers by capillary-driven thinning of drying viscoelastic filaments
… Giesekus model with a concentration-dependent shift factor that accounts for compositional dependence of the zero shear rate viscosity and the relaxation time of the fluid. An averaged mass transfer coefficient accounts for evaporation by conduction. The numerical simulations are compared to …
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Measuring and predicting sealant adhesion
… humidity is less than 35%. The temperature shift factor was not related to the WLF theory but worked well with an Arrhenius theory. The activation energy for the fracture process was 31.2 kcal/mol. Crack growth data for an expansion joint was calculated for the weather conditions in Miami, …
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The Role of Penetrant Structure on the Transport and Mechanical Properties of a Thermoset Adhesive
… variables. The concept of a diffusion-time shift factor (log aDt) has been introduced to create doubly-reduced master curves, taking into account the effects of temperature and the variations in the polymer mechanical response due to the existence of a low molecular weight penetrant.
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Modeling of the linear viscoelastic response of polymer modified asphalt binders at intermediate and high temperatures
… engineering problems was presented. The measured shift factor data was used to study the dependency of the viscoelastic response on temperature variations. It was observed that this dependency is dominated by the asphalt phase. Within the studied range of temperatures, the WLF equation with …
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Adaptive Hierarchical Control in V2G Integrated Micro-grids
… identification with a variable forgetting factor for system identification, and pole-shifting control with a variable pole-shift factor for control synthesis. In Part II of the thesis, an ANFIS based EMS is proposed for micro-grid energy management at the secondary level of the hierarchical …
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Wetlaid Cellulose Fiber-Thermoplastic Hybrid Composites - Effects of Lyocell and Steam Exploded Wood Fiber Blends
… for PP and its composites. Comparison of shift factor versus temperature plots revealed decreasing relaxation times of PP with increasing lyocell concentration, which indicated that PP interacted better with lyocell than with SEW fibers. Finally, it was observed from sorption tests that …
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The Effects of Structure, Humidity and Aging on the Mechanical Properties of Polymeric Ionomers for Fuel Cell Applications
… isotherms were measured. A mastercurve and a shift factor plot were constructed for 60% sulfonated Dais® membrane. It was determined that an increase in the degree of sulfonation raised the glass transition temperature of these materials by facilitating the formation of the ionic clusters …
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Internal Variable and Temperature Modeling Behavior of Viscoelastic Structures -- A Control Analysis
… a time-varying controllers. With the aid of the shift factor, the eigenvalue variation with temperature is used as a time-varying function in the design. The results show that good track performance and regulation can be achieved with a control law that is capable of compensating for temperature …
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Structure-Morphology-Property Relationships in Perfluorosulfonic Acid Ionomer Dispersions, Membranes, and Thin Films to Advance Hydrogen Fuel Cell Applications
… be superposable by implementing an aging time-RH shift factor, allowing for prediction of quasi-equilibration times under given fuel cell operating conditions.
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Regulation of Mitochondrial Function by Histone Acetylation and Mitochondrial Acetyl-CoA Levels in Saccharomyces cerevisiae
… mediated by three classes of transcription factors (TFs), including the general stress response factors Msn2/4, the post-diauxic shift factor Gis1 and the heat-shock factor Hsf1. In the first result chapter, the contribution of the three classes of TFs to the expression of chaperone …
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Development of Laboratory to Field Shift Factors for Hot-Mix Asphalt Resilient Modulus
… size using Roque and Buttlar's correction factors is applicable. However, at higher temperatures, HMA behavior becomes relatively more viscous. Hence, erroneous resilient modulus values could result when elastic analysis is used. In addition, due to difference in relative thickness between …
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Allowable bending strength enhancement of 2 by 4 lumber by tension and compression proofloading
… distribution are artificially altered by a factor K until the probabilities of failure for the proofloaded and control groups are similar. The K is a shift factor relating the amount the proofloaded strength distribution must be shifted on the x-axis to give the same reliability as the …
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Long-term creep modeling of wood using time temperature superposition principle
… at successively higher temperature levels were shifted along the log-time axis with respect to the curve section at 70°F to construct a master curve for each specimen. The extrapolation of the developed master curves ranged from 0.23 to 6.4 years. The requirement that the shift factors below …
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Real-time power system operational reliability tools
… a measurement-based approach to marginal loss factor (LF) estimation, which harnesses phasor measurement unit (PMU) measurements to estimate the LFs online rather than computing them from a power flow model; (ii) a formulation of the line outage angle factor (LOAF), the computation of which …
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PERMEABILITY AND MOISTURE DAMAGE CHARACTERISTICS OF ASPHALT PAVEMENTS
… that field permeability is affected by several factors such as 3D flow in the field, Open Graded Friction Coarse (OGFC), tack coats. To this end, an analytical model is developed to predict field permeability from laboratory permeability. Model permeability is found to be higher than the …
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