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 17 of 17 for “"tan delta"”.
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Application of Thermomechanical Characterization Techniques to Bismuth Telluride Based Thermoelectric Materials
… TE materials is presented. The TE materials' tan delta values, indicative of viscoelastic energy dissipation modes, approached that of glassy or crystalline polymers, were greater than ten times the tan delta of structural metals, and reflected the anisotropic nature of TE materials. DMA …
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Origins of Enhanced Dielectric Properties in Titania-Modified Tantalum Pentoxide Ceramics
… containing 8% TiO2 exhibited dielectric constant (K) values of ∼280 at 20°C with tan delta values ∼0.01, but undoped specimens had tan delta values of ∼0.10 and DC resistivity values of <1011O·cm. Hyper-Raman spectroscopy revealed that the ionic polarizability (and thus …
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Solution-Based Deposition of Ultrathin Metal Oxide Films on Metal and Superconductor Surfaces
… fabricated by this method displayed capacitance densities between 0.09 tauo 0.50 muF/cm2 (tan delta = 0.09 to 1.12) and current densities between 10-2 to 10-4 A/cm2.
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Effect of moderate magnetic annealing on the microstructure and mechanical behavior of a structural epoxy
… comparing the textures and fully understanding the mechanisms that result in a preferred orientation generation. The texture analysis revealed that under such moderate magnetic field and due to the diamagnetism of the epoxy system, the chains and the cross linking reorient biaxially in a …
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Material and Damping Characterization of Discretized Adhesive Tapes in Cantilever Beams undergoing Free and Forced Vibration
… to measure shear storage and loss moduli, and tan delta from dynamic mechanical analyzer measurements. Second, the optimal discretization length for different damping tapes was experimentally determined and analytically verified using linear viscoelasticity and basic strength of materials and …
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Friction, wear and mechanical properties of electron beam modified PTFE-based rubber compounds
… Materialeigenschaften, d.h. Härte, E-Modul und tan delta (Verlustfaktor) der Gummimischungen sind kritische Parameter und erfordern deshalb eine Optimierung. In dieser Arbeit wurden zwei Modellsysteme untersucht, die auf zwei unterschiedlichen Kautschuktypen basieren: a) …
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Characterization of graphite polyurethanes composite from renewable based oils
… (VCO) as a renewable resource is the main substance in fabricating the renewable polyurethane (PU) and its graphite as called polyurethane graphite (PG). The fabricating sample have two methods that is open casting and heat press method. PU and PG with different percentage of graphite as filler …
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Testing for relationship between diagnostic tests and DC BDV of in-serviced aged stator bars of a hydro generator
… a challenge to utilities. A cognisance and understanding of the actual condition of these assets will enable utilities to implement mitigation strategies and use these assets for the full duration of their lifespan. One of these assets could be hydro generators with the stator bars constituting …
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Characterization of developing porcine cortical bone: applications of mechanical and optical methods
… set of characterization techniques is to understand and catalogue the changes that occur in bone due to biological factors. By understanding the various characteristics of bone, i.e. mineralization levels, property variations between quadrants, effects of disease, and microstructure variations, …
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Frictional oscillations in elastomeric sliding
… state sliding where the sliding friction is constant; 2. A high frequency self-excited oscillation of the test structure superimposed on the mean value of friction; 3. Stick-slip, where the elastomeric specimen goes through alternating periods of no relative and relative motion to the …
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Impact of ingredient selection on rheological properties of a semi-liquid syrup model for use in pulp/paste candy
… difference between all levels) and minimum tan (delta) (mid and high level were similar). Using a stepwise method, ANOVA models were generated that showed statistically significant effects on complex viscosity for gum level and sugar level as well as interactions (p < 0.05) between invert …
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Rheological and Thermal Insights into Solidification Dynamics in Extrusion-Based Additive Manufacturing of Polymer Composites
… and support subsequent layers, requiring understanding of the viscoelastic properties of the material and the use of solidification mechanisms to ensure structural integrity during printing. While solidification favors shape retention, it hinders interlayer chain diffusion, compromising …
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Durability of Polyimide/Titanium Adhesive Bonds: An Interphase Investigation
… interface, becomes critically important. Frequently, failure occurs in this region after adhesively bonded systems are subjected to elevated temperature oxidative aging. In a previous study, this was found to be the case with a polyimide adhesive bonded to chromic acid anodized (CAA) …
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Improving the quality of non-wheat bread made from maize using sourdough fermentation
… alternative because it is by far the most important crop produced in Africa. However, it lacks gluten, the protein that is formed in wheat dough which is responsible for the desirable quality attributes (high loaf volume, soft and open crumb structure) of wheat bread. Therefore the need arises …
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Dielectric Properties of Molecular Glass Formers; from the Liquid State to the Tunneling Regime
… peak. A new approach is introduced to disentangle the different spectral contributions (alpha-process, EW and beta-process). At variance with previous interpretations, the spectral shape of the alpha-process is assumed to be temperature invariant, obeying frequency temperature superposition …
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Characterization of Pharmaceutical Materials by Thermal and Analytical Methods
… with the United States Pharmacopeia (USP) standard set of active pharmaceutical ingredients (API). DEA measures and differentiates the crystalline solid (low; 10¿¿¿¿¿ pS/cm) and amorphous liquid (high; 10¿¿¿ pS/cm) API electrical ionic conductivity. DEA ionic conductivity cycle establishes …
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Mechanical modulation of indirect repair mechanisms for improved hematopoietic recovery
… recovery after transplantation an outstanding challenge. Successful long-term engraftment of hematopoietic stem cells is dependent largely on the surrounding stroma components or hematopoietic niche. Cell types within this niche that support hematopoietic recovery include two adherent …