Global ETD Search
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 29 for “"complex modulus"”.
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A response surface for the complex modulus of composite materials
… in the development of response surfaces for the complex moduli of composite materials.
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Development of differential scheme micromechanics modeling framework for predictions of hot-mix asphalt (HMA) complex modulus and experimental validations
The viscoelastic modulus of hot-mix asphalt (HMA) such as the complex modulus, E*, is an essential material parameter for better paving mixture design and asphalt pavement design. Under certain circumstances, it is desirable that a reasonable modulus value of certain HMA mixtures be estimated for …
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Determination of the complex modulus of a solid propellant and random vibration analysis of the layered viscoelastic cylinders with finite element method
Aeronautical structures, such as aircraft or missiles, are usually highly sophisticated systems often subjected to random vibration environment. Thus, in various design, development, and production stages, laboratory random vibration testing of sampled solid rocket motors on electromagnetic or …
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Impact of recycled asphalt shingles on asphalt concrete characteristics
… program for the regular mixes included complex modulus, fracture, overlay reflective cracking resistance, wheel track permanent deformations, and push-pull fatigue tests. The asphalt binder replacement levels in the mix using combinations of RAS and RAP were in the range of 43% to 64%. …
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Optical rheology for live cell membranes
… enclosing a homogeneous fluid. The full complex modulus of RBC in terms of temporal frequency and spatial frequency is retrieved 'without contact, for the first time to our knowledge. Sub-nanometer sensitivity diffraction phase and fluorescence microscopy (DPF) quantifies non-invasively …
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Impact of curing time on warm mix asphalt short-term performance
… decreased temperatures may affect the resulting complex modulus to withstand traffic loads. A performance evaluation of WMA over various ‘curing’ periods would determine the evolution of the complex modulus over time. This allows to identify the optimum time for opening WMA paved surfaces to …
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Dynamic Behaviour of Composite Structures Containing Viscoelastic Materials, with Applications to Solid Fuel Rocket Motors
… a viscoelastic material, no reliable data on the complex modulii of the propellants were available so a method was developed to measure it - the admittance method. This consists of vibrating a rod longitudinally, the applied force is kept constant the acceleration at the free end and the phase …
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Quantitative estimates of mechanical properties from in vivo tumors of rodent animals
… rodent mammary tumors to estimate the complex shear modulus under realistic conditions, and to assess the sensitivity for relating matrix viscoelasticity to tumor type and stage. Cylindrical, harmonic shear waves generated by a vibrating needle (50-450 Hz) were tracked by …
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A Finite Element, Reduced Order, Frequency Dependent Model of Viscoelastic Damping
… into the model in the form of a curve fit of the complex modulus. This curve fit is expressed by minioscillators. The frequency dependence of the complex modulus is accounted for by the addition of internal, or dissipation, coordinates. The dissipation coordinates make the viscoelastic model …
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Development of Antioxidant Treatments for Asphalt Binders and Mixtures
… tests including creep compliance, dynamic complex modulus, indirect tensile strength, fracture energy, and moisture susceptibility testing. The results of the study indicate that asphalt aging could be reduced significantly through the use of antioxidant treatments developed during the …
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Passive Damping in Stiffened Structures Using Viscoelastic Polymers
… structures and the investigation of associated complex modes. The key idea behind constrained damping treatment is to increase damping as affected by the presence of a highly damped core layer vibrating mainly in shear. Our main goal was to incorporate viscoelastic material in a thick stiffened …
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Investigating Ageing of Neurodegenerative Disease Relevant Protein Condensates
… condensate properties including viscosity, complex modulus, and fusion behaviour are investigated and revealed with innovative tools and techniques. At present, little is known about the absolute viscosity of biomolecular condensates both *in vivo* and *in vitro*, especially as a function of …
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Jatropha curcas oil as a bio-based rejuvenating agent for reclaimed asphalt pavement mixtures
… master curves, the addition of JCO decreased the complex modulus values compared to the virgin binder sample. Atomic force microscopy (AFM) and Fourier Transform infrared (FTIR) test results showed the ability of JCO to reduce the effects of aging. The performance of recycled asphalt mixtures was …
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The effects of micro and nano size bauxite particles in modified asphalt binders and asphaltic mixtures
… with MBP and NBP were evaluated for resilient modulus, dynamic creep and rutting susceptibility. In this study, the size of MBP and NBP used were less than 75 μm and in ranges of 10 nm to 20 nm, respectively. The result shows that the addition of 7% MBP and NBP in asphalt binder have decreased …
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Influence of sand friction angle, grout stiffness, and confinement on the behavior of acrylamide and sodium silicate grouted sand
… presented using the grouted sand stiffness and complex modulus, along with ungrouted sand properties such as friction angle and gradation. Finally, the results showed that instead of using unconfined compression tests, confined compression tests on grouted sand will be more representative of …
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Development of Surface Acoustic Wave Optical Coherence Elastography (SAW-OCE) for Soft Tissue Characterisation
… heterogeneous material, the 2D Young’s modulus map was reconstructed based on the SAW group velocity with an improved time-of-flight method, i.e., the multi-kernel-weighted-averaging (MKWA) method. In a vertically heterogeneous material, the elasticity of each layer was evaluated by …
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Complex shear modulus reconstruction using ultrasound shear-wave imaging
… tissue mechanical properties, specifically the complex shear modulus. Advancing this field has the potential to bridge molecular, cellular, and tissue biology and to influence medical diagnoses and patient treatment. This dissertation describes several quantitative developments in the field of …
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Characterization of developing porcine cortical bone: applications of mechanical and optical methods
… from cortical bones of left femora to determine modulus of elasticity and ultimate compressive strength. Finally, bone samples were dried and ashed to determine porosity and bulk mineral volume. The next study is a demonstration of the quantitative backscattered electron imaging technique (QBEI). …
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Analysis of Hot Mix Asphalt (HMA) Linear Viscoelastic and Bimodular Properties Using Uniaxial Compression and Indirect Tension (IDT) Tests
… (M-E) flexible pavement design is the dynamic complex modulus obtained from either the uniaxial or triaxial compressive dynamic modulus test. Furthermore, as part of the performance-based mix design process, the triaxial dynamic modulus has been selected to predict rutting and fatigue cracking, …
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Effects of Coarse Aggregate Morphological Characteristics on Mechanical Performance of Stone Matrix Asphalt
… Test included wheel-track loading, dynamic modulus, flow number, and beam fatigue. The wheel tracking test included asphalt pavement analyzer (APA) and Model mobile load simulator (MMLS). In the APA test, samples included eight types of SMA mixtures that consisted of aggregates of 22 …
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