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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 330 for “"unit cell"”.
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Measurements of Unit Cell Parameters of Three Pd-Complexes
No abstract prepared.
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K, Na distribution and unit cell parameters of alkali feldspars.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Geology and Geophysics, 1968.
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Substrate integrated waveguide microwave antenna and filter design using H-fractal unit cell
… integrated waveguide with H-shaped fractal unit cell is proposed in this work to overcome these challenges. The proposed antenna operates at 4 GHz and 5.7 GHz frequencies bands which suite the lower 5G applications. The proposed antenna was designed and simulated by using CST MWS …
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A Novel Unit Cell Antenna for Highly Integrated Phased Arrays in the SHF Band
… <p>On a prior effort, an integrated unit cell design was developed for a PCB-based SATCOM array application. However, the design failed to meet the requirements. The primary objective of this work is to demonstrate an improved design using systematic microwave design techniques and …
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An empirical potential for hydrogen bond energies determination of the orientation of anthracene molecules in the unit cell by means of a refractivity method: some ab initio calculations involving acetonitrile exchange reaction
… optimizing the orientation of molecules in the unit cell by matching calculated and experimental refractivity ellipsoids using a simplex algorithm. The calculated refractivity ellipsoid is determined by use of an empirical formula using bond directional polarizabilities. Optimization of the …
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The crystal stucture determination of low and high temperature phases of Tris (Ethylene Terephthalate)
… The LTP crstals were found to have a monoclinic unit cell and spac%C; the unit cell is a = 16.98A°, b = 19.59A °, c = 8.43A and $ 96.240 with z = 4 molecules/unit cell; d(obs) = 1.367 g/cm 3 . The HTP trimer crystals were formed from a hot solution of tris(ethylene terephthalate) and Dekalin …
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An improved size, matching, and scaling synthesis method for the design of meso-scale truss structures
… Mesoscale lattice structures are a type of cellular structure with support element sizes on the order of magnitude of centimeters. These types of structures are engineered for high performance and have applications in industries where both low weight and high strength are desired. However, …
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Towards High-Performance Reflectarray Antennas: Phase Sensitivity Reduction for Wide Bandwidth
… and simulated using a Jerusalem cross-shaped unit cell. While promising, this design highlighted the necessity for a deeper understanding of the field behavior within the unit cell. Thus, the focus shifted to a rectangular dielectric resonator unit cell, which offers more precise insights into …
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Mechanical Characterization of Selectively Laser Melted 316L Stainless Steel Body Centered Cubic Unit Cells and Lattice of Varying Node Radii and Strut Angle
… and strut angle of the body centered cubic unit cell was performed to determine the mechanical properties and failure mechanisms of the mesostructure. Quasi static compression tests were performed on an Instron® universal testing machine with a 50kN load cell at 0.2mm/min. The test samples …
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The crystal structure of cholesterol helical ribbons
… I was able to deduce the parameters of the unit cell. The crystal structure of these ribbons is similar to that of cholesterol monohydrate, with the important difference that the length of the unit cell perpendicular to the cholesterol layers is tripled. Furthermore, I found that adjacent …
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Influence of geometric parameters on 3D periodic lattice effective properties
Lattice materials are generated by tessellating a unit cell, composed of a specific truss configurations, in an infinite periodicity to combine the effect of bulk material properties and geometric periodicity. They offer enhanced mechanical and dynamic properties per unit mass, and the ability to …
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Diffraction spectroscopy of metalloproteins
… within a protein, that builds on prior small unit cell Diffraction Anomalous Fine Structure experiments and harnesses the collection and processing software commonly used in large unit cell crystallography. A technique (dev + PCA) has been developed to retrieve the small signals from …
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Monte Carlo study of pebble bed reactor fuel reactivity and isotopics
… evaluate the neutronics of the PROTEUS LEUPRO-1 unit cell. Models were made at various levels of simplification for the actual spherical geometry as well as the equivalent cylindrical geometry, to test their ability to reproduce results described in several published reports. These models were …
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Numerical Constitutive Models of Woven and Braided Textile Structural Composites
… elastic moduli are determined from unit cell models of balanced plain weave, 2D braid, 2D triaxial braid and 4x4 twill textile composite materials consisting of interlaced or intertwined yarns. The yarn paths are modeled with undulation portions, in which one yarn passes over and …
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Vibrational studies of tetrahalogenocuprates (II)
… were critically discussed. A unit cell analysis of the compound was performed with two primary objectives: (A) to interpret the vibrational spectrum; and (B) to develop a competent model force field for such study. The analysis produces a physically sensible set of force …
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Determining the Crystal Structure of Cellulose III by Modeling
Recently, a one-chain monoclinic unit cell for Cellulose IIII having a single glucose in the asymmetric unit was proposed based on high-resolution diffraction patterns. The new work challenged a two-chain structure published 25 years earlier, although it did not provide new three-dimensional …
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Design and simulation for the fabrication of integrated semiconductor optical logic gates
… this research, we present an all-optical logic unit cell with complete Boolean functionality as a representative circuit for modeling and optimization of monolithically integrated components. Proposed optical logic unit cell is based on an integrated balanced Mach-Zehnder interferometer (MZI) …
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Optimising the axial ratio bandwidth of resonant linear to circular polarisation converters
By careful design of the unit cell, resonant FSS's are capable of converting a linearly polarised wave to a circularly polarised wave whilst simultaneously filtering an incident signal at 'out of band' frequencies. Printed FSS's fit for this purpose have been widely reported in technical …
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A surface texture modeling system for solid freeform fabrication
… to be: 1. That the informational model of the unit cell of texture be separable into distinct logical subsets.2. That manipulations on either subset not violate the logical consistency of the other subset. This thesis shows that geometric dimensions and tolerances carry the essential …
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