Materials Literature
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We present a description of the reorientation of the macroscopic polarization P S under a switching field in a ferroelectric liquid crystal assuming the direction of P S is spatially uniform but time‐dependent throughout the sample. The driving torques are then the linear ferroelectric coupling and the quadratic diele…
Using first-principles total energy calculations within density functional theory, we investigate the energetics, kinetics, and transport properties of Ti on clean and hydrogen-terminated diamond (100)-2x1 surfaces at increasing Ti coverages. On a clean surface, an isolated Ti adatom prefers to adsorb on top of a C-C…
Commercial and nano calcium carbonate (CaCO3) filled epoxy composites were processed at 2 to 10 wt% compositions. Nano size CaCO3 was synthesized using in-situ deposition technique. Its nanosize and mixing with epoxy were confirmed by X-ray diffraction (XRD) method. X-ray diffractograms show that complete exfoliation…
High pressure die casting is the most important production method for casting magnesium alloy components, and uniformity of appearance is an important criterion for acceptance of a component by customers. This paper investigates the influence of uniformity in surface appearance of diecast AZ91D plates on their corrosi…
The primary water stress corrosion cracking (PWSCC) of Alloy 600 (UNS N06600), Type 304 (UNS S30400), and Type 316 (UNS S31600) stainless steels (SS) was studied at 360°C and at nominal strain rates ranging from 1 × 10-7 s-1 to 1 × 10-5 s-1 using the slow strain rate tensile technique (SSRT). It was revealed that the…
: Rice husk (RH)-unsaturated polyester (USP) composites have been produced. The tensile, flexural, impact, and dimensional properties of the composites have been investigated. From the results, it was observed that the tensile, flexural, and impact properties decreased as the percentage of filler was increased. The co…
The spectrum of spin fluctuations in the stacked-triangular antiferromagnet YMnO3 was studied above the Néel temperature using both unpolarized and polarized inelastic neutron scattering. We find an in-plane and an out-of-plane excitation. The in-plane mode has two components just above T N : a resolution-limited cent…
The second-harmonic signal generated within poled silica disks is monitored in real time as the sample is etched with hydrofluoric acid. An oscillating signal is observed when the cathodic side of the sample is etched. This result is in good agreement with the condition of zero potential difference between the two sur…
Oxide–oxide composites were evaluated in a novel combustor design requiring higher wall temperatures than the conventional combustors. The evaluation was based on a combination of numerical modeling and experimental rig testing. The modeling included computational fluid dynamics (CFD) calculations whose results were u…
Si 3 N 4 /SiC composite ceramics were hot‐pressed in order to investigate the crack‐healing behavior under stress. Semi‐elliptical surface cracks of 100 μm in surface length were made on each specimen. The pre‐cracked specimens were crack‐healed under cyclic or constant bending stress, and the resultant bending streng…
Packing density, the fiber distribution in a yarn cross section, can to a great extent influence the properties and quality of the yarn. Thus, the need for precise and concise information about packing density becomes a must for an in-depth understanding of yarn structure and hence yarn mechanics. This paper describes…
Crystals of divalent tungstates are characterized by two main luminescence spectral ranges: a short-wavelength (blue) luminescence band in the range 390–420 nm and a group (often two groups) of longer wavelength (green) bands in the range 480–520 nm. For crystals of calcium, strontium, barium, cadmium, magnesium, zinc…
Dipicolinic acid (DPA) and the Ca2+ complex of DPA (CaDPA) are major chemical components of bacterial spores. With fluorescence being considered for the detection and identification of spores, it is important to understand the optical properties of the major components of the spores. We report in some detail on the ro…
Abstract The small particle size and the random stacking of layers has previously hindered systematic structure investigations of montmorillonite. By applying the convergent-beam electron diffraction mode (CBED) of a transmission electron microscope (TEM) with a beam spot of ~800 Å we were able to examine undisturbed…
The physisorption of radiolabeled (125)I(-) ions from aqueous solution and the Brunauer-Emmett-Teller (BET) surface areas of various carbonaceous materials [HiPco single-wall carbon nanotubes (SWNTs), F-SWNTs, cut SWNTs, charcoal, graphite, F-graphite and C(60)] have been measured and compared. By far, cut SWNTs (main…
Semiempirical calculations on the dihydrated Zn (II) acetate and monohydrated Cu(II) acetate structures have been carried out. The optimized structures by the PM3 and AM1 methods were compared with crystallographic data in order to analyze the reliability of the data and its use in the calculations of the structures o…
The effects of crystallographic texture and microstructure are analyzed for polycrystalline tetragonal BaTiO 3 , pseudotetragonal PZN–PT, and cubic BaTiO 3 . For tetragonal BaTiO 3 and pseudotetragonal PZN–PT, we demonstrate that a high anisotropy of the single‐crystal properties induces an apparent enhancement in the…
Rheology is demonstrated to be a sensitive and quantitative probe of weak attractive forces acting in concentrated stable colloidal dispersions through comparison of rheology and small-angle neutron scattering measurements on a model dispersion with added polyampholyte. Polyampholyte-stabilized dispersions are found t…
This paper investigates a nonlinear controller designed to stabilize a single-degree-of-freedom rotary shape memory alloy (SMA) actuated robotic arm. To this end, a bias-type robotic arm was built using 150 pm Flexinol SMA wire. This robot is designed to lift and position lightweight objects. Upon complete phase trans…
We have developed a process for optimizing sewing conditions to minimize seam pucker using the Taguchi method. The process is applied to two different T/C fabrics with the specified experimental design using an optimum orthogonal array table. The parameters selected for optimization are sewing speed, stitch length, se…