Materials Literature
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The layered intergrowth phases Bi4MO8Cl (M = Nb, Ta), structurally related to the well-known Aurivillius phase ferroelectrics, have been studied using SHG and a.c. impedance techniques. Both undergo a polar to centrosymmetric phase ferroelectric-type transition (Tc = 765 and 640 K for M = Nb and Ta, respectively). The…
The cationic ring-opening polymerization of tetramethylene urethane (TeU; systematic name, hexahydro-1,3-oxazepin-2-one, ( 1 )) in the melt at 67 °C with methyl trifluoromethanesulfonate (TfOMe) as the initiator yields poly(tetramethylene urethane) (poly(TeU), ( 6 )) with a regular microstructure. This [5]-polyurethan…
In this paper the influence of crack‐deflecting interlayers on the thermal shock behavior of a ceramic body has been studied. It is observed that the presence of such interlayers inhibits the penetration of cracks into the body and that the magnitude of this effect is much greater than that of internal stresses or of…
Abstract This article provides information on the applications of metal-matrix composites in engine components, brake system, and driveshaft. The components include pistons, cylinder liners, valves, pushrods, and connecting rods.
This review presents a systematic and comprehensive survey of the methods of preparation, structural studies, chemical reactivities and synthetic potentiality of dithiols.
The resistivity and the thermal stability of transparent conducting ZnO layers doped with aluminum have been correlated with the conditions of the sputtering process. Layers deposited at low rf power density (∼1.3 to 2.6 W/cm2) exhibit a low resistivity of 9×10−4 Ω cm, predominantly due to a high concentration of intr…
The formation of fluorite-type solid solutions with compositions (n)MnOx–(1 − n)CeO2 is effective in increasing adsorptive NO uptake. Solid–gas interactions for NO adsorbed onto preoxidized samples was studied by the use of diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) to elucidate the role of e…
The symmetry changes and length of the symmetry independent part of [Cu(amtrz)3]n2+ (amtrz = 4-amino-1,2,4-triazole) polymeric chains driven by different anions in crystals with BF4− (1), BF4−/SiF62− (2) and SiF62− (3) have been studied by single crystal X-ray method.
Ultrathin (<5 nm) hard carbon films are of great interest to the magnetic storage industry as the areal density approaches 100 Gb/in/sup 2/. These films are used as overcoats to protect the magnetic layers on disk media and the active elements of the read-write slider. Tetrahedral amorphous carbon films can be produce…
We have succeeded for the first time in preparing single crystalline films of SrFeO3, CaFeO3, and Sr2FeCoO6, perovskites containing Fe4+, at low oxygen pressure of only 1 kPa, and the dominance of oxygen hole character in transport phenomena was indicated by the positive Hall coefficient of metallic SrFeO3.
Single crystal and powder diffraction investigations have revealed that the paraelectric phase of cesium dihydrogen phosphate, CsH2PO4 (CDP), from the crystallographic point of view is stable (space group P21/m) up to ca. 231 °C. At this temperature a structural phase transition from the paraelectric phase to the supe…
Aluminum specimens were covered with film by a sol-gel coating and then anodized galvanostatically in a neutral borate solution. Time variations in the anode potential during anodizing were monitored, and the structure and dielectric properties of the anodic oxide films were examined by transmission electron microscop…
The present investigation is focused on x-ray photoelectron spectroscopy (XPS) and x-ray excited Auger electron spectroscopy (XE-AES) analysis of the main core levels (O 1s, Co 2p, and Co LVV) of nanocrystalline Co3O4 coatings. The samples were obtained by CVD and sol-gel routes. Co(dpm)2 (Hdpm = 2,2-6,6-tetramethyl-3…
The optical constants of discontinuous gold films consisting of both embedded and unembedded spherical particles in the size range 5–14 nm were determined from spectroellipsometric and spectrophotometric measurements. The optical response was modeled with the Yamaguchi anisotropic dielectric function. The energy and w…
In view of the ever-increasing pipeline length and operating pressure, the development of high-strength steels makes a significant contribution to pipeline project cost reduction. In the case of offshore pipelines, the operating pressure of the pipeline does not play the dominating role. It is rather the ambient water…
We present a convenient and safe one-pot route to capped 3 nm CdSe nanoparticles making use of common starting materials and inexpensive, low-boiling solvents under solvothermal conditions; H2Se required for the reaction is generated in situ through the aromatization of tetralin by Se.
We report acoustic measurements of popping bubbles during the collapsing of aqueous foams. The sound pattern is analyzed using classical methods of statistical physics. It is found that membrane rupture concerns a wide variety of situations: small and large membranes at the air/foam interface. Avalanches of popping bu…
Reaction of acrylamide with vanadium phosphorus oxide VOPO4·2H2O at room temperature yielded the intercalation compound without degradation of the VOPO4 layers. Two types of intercalation compounds were formed: the intercalation compound washed with n-heptane accommodated acrylamide with a bilayer arrangement, and the…
This research focused on whether bacteria living in aerobic environments where Fe is often a limiting nutrient could access Fe associated with the clay mineral kaolinite. Kaolinite is one of the most abundant clays at the Earth's surface, and it often contains trace quantities of Fe as surface precipitates, accessory…
The aim of this study was to find the scale-up parameters necessary for the preparation of nanocapsules (NCs) for pharmaceutical purposes. Starting from the laboratory scale (0.06 L), we designed and assembled a pilot plant (2 L) to produce NCs with the so-called emulsification-diffusion technique. We wanted to check…