Materials Literature
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The nature and degree of damage accumulation beneath Hertzian contacts in silicon nitride‐based laminates are studied. Specimens with alternating homogeneous and heterogeneous layers are fabricated by a tape‐casting route, with strong interlayer bonding. Homogeneous material consisting of relatively pure fine‐grain si…
Since their discovery in the 1960s, shape memory alloys have been developed for a wide range of applications. However, it was not until the 1970s that the use of memory metals in medicine started to receive attention. Since then, a multitude of clinical functions have been looked into, all of which use the Nickel-Tita…
All articles of this category Chiral hyperbranched macromolecules catalyze the enantioselective diethylzinc addition to benzaldehyde. The corresponding secondary alcohol has been obtained in high yield with good enantioselectivity (up to 86% ee ). Hyperbranched Macromolecules - Dendrimers - Asymmetric Catalysis - Enan…
Vibrational frequencies for 11 alkenes and 8 conjugated hydrocarbons have been analyzed with MM4. The root mean square (rms) difference between the experimental and MM4 values is 25 cm−1 for seven alkenes and 31 cm−1 for eight conjugated hydrocarbons, compared to MM3 rms differences of 38 cm−1 for alkenes and 52 cm−1…
In two consecutive one-electron oxidations, oligopyrroles substituted with phenyl capping groups (PhPynPh, n = 2–4) can be oxidized reversibly to give stable cation radicals and dications. Spectroelectrochemical studies give direct evidence that diamagnetic π-dimers of cation radicals are formed in solution. Such dime…
The phase field model in two dimensions is used to calculate numerically the operating states (tip velocity $v$ and tip radius $\ensuremath{\rho}$) of dendrites grown from pure melts. At large supercoolings, a dendrite has a nearly hyperbolic envelope close to its tip, as opposed to being nearly parabolic, as at small…
Jahn-Teller (JT) electron-phonon-coupling effects in the colossal-magnetoresistance perovskite compounds ${\mathrm{La}}_{1\ensuremath{-}x}{A}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ are investigated. Electron-electron correlations between two degenerate Mn ${e}_{g}$ orbitals are studied in the Gutzwiller approximation. The st…
Coexistence of two phases, having different in-plane dimensions, is found in the planar Sr2−xLaxMnO4 for 0 < x ≤ 0.38 at room temperature. Furthermore, charge ordering with modulation wave vector (π2, π2) is discovered for x=0.5 below ∼ 250 K. Together with transport and magnetic measurements, these results indicate t…
The origin of spurious and irreproducible signals in the measurement of the hyper-Rayleigh scattering (HRS) of solutions is investigated. A new cell design, coupled with continuous solution filtration through a 20 nm filter, is shown to improve the reproducibility of the measurement to ±5%. A transverse cell dimension…
Abstract The polymerization of a bismaleimide‐styrene system was studied by using a model compound, p‐maleimidobenzoic anhydride, that can be split by simple hydrolysis. Compared to known divinyl systems, a decreased reactivity of the pendant double bonds is observed, probably as a result of cyclization and the steric…
Abstract Cold rolling mill productivity and product quality depend on the lubricant chemistry and composition, as well as on such physical factors as operation and maintenance. This paper discusses new requirements for rolling mill oils. Ester‐based rolling oil formulations have been developed and their performance is…
A protocol for global analysis of x-ray photoelectron spectra of plasma-deposited polymer films is presented. These materials are difficult to analyse because of the multitude of different chemical groups present. The combination of different primary and secondary binding energy shifts results in relatively broad, fea…
In this paper, the recent development of a computer-aided partial discharge (PD) acoustic location system is briefly introduced. The paper presents the characteristics of this system with emphasis on the acoustic locating technique and interference countermeasures. Signal recognition, ascertainment of time delay and t…
Abstract The dehydroxylation and rehydroxylation properties of titania (Degussa P‐25) were investigated. FTIR and TPD‐MS data indicate that hydroxyl groups are not completely removed at 500 °C in vacuo , and rehydration/rehydroxylation occur under helium (water content < 1 ppm) flow at room temperature. In addition…
Abstract There were two objectives in the study: 1) To determine exchangeable K and non‐exchangeable K in soils with different potassium depletion levels and mineralogy as plant sources 2) To establish a relationship between the mineralogy vs exchangeable K (Ke) and non‐exchangeable K (Kne) mobilization. An extraction…
A procdure using the Reverse Monte Carlo technique was shown to find the correct microscopic density of scattering centers (atoms, ions, etc.) in a model liquid within about 2%, on the sole basis of diffraction data. The method was also tested on solid amorphous systems of low, as well as of high packing fractions. An…
In order to be able to reduce the leakage of contaminant out of a fume cupboard it is first necessary to investigate the detailed fluid flow patterns inside and around the fume cupboard. Because of the difficulties and expense of performing these experiments, in this paper a computational fluid dynamics approach has b…
Abstract The practical application of high impact polystyrene (HIPS) depends on the resistance to aging in aggressive environments. The investigation of morphological, mechanical, and chemical properties was made on HIPS samples of various thickness. The property deterioration of HIPS caused by concentrated nitric aci…
The electrical failure of multilayer ceramic capacitors (MLC's) subjected to environmental screening testing (EST) environments is systematically studied in this work. Based on results obtained from comparative EST environments, it is shown that a thin water film can appear on the MLC surface as a result of water vapo…
Abstract We have studied mechanical and rheological behavior of poly(vinyl acetate) (PVAC) composites filled with calcite as a function of filler particle geometry, particle size distribution, and active surface area. Detailed morphological characteristic were investigated. Tensile properties of PVAC composites were e…