Materials Literature
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Calculations of field components for thin-film recording heads originally done with the finite difference method on a desktop computer were redone using a mainframe computer. The new computations agree much better with experimental results and give simpler, more accurate coefficients for the equations previously publi…
Precision measurements of the dispersion relations for phonons along the high-symmetry directions in gamma -Sn (Sn 0.8 In 0.2 ) have been performed at room temperature by inelastic neutron scattering. Phonon group velocities have been extracted from the data with an accuracy of 5-10%. Several abrupt changes of group v…
Abstract There is increasing demand for high temperature greases capable of operating in the range of 175–235°C. In this paper, one type of grease, polyurea, is described, and its preparation given, in terms of raw materials, temperature, solvents, base fluids including synthetics, catalysts, additives and thickeners.…
Many articles of protective clothing have become quite expensive, and consequently, there is need for reuse of those articles. One concern, however, is whether the articles require decontamination if they are splashed by a liquid or contact a hazardous gas. Concerns over contamination involve two important aspects: 1)…
Abstract Two types of polypyrazoles, unsubstituted and phenylated, were prepared by a novel synthetic route involving the cyclopolycondensation of aromatic dihydrazines and aromatic dipropynones. The polymers had inherent viscosities as high as 1.05 dL/g and were soluble in N, N ‐dimethylacetamide, chloroform (phenyla…
A new model for describing hysteresis is proposed. The magnetization is separated into reversible and irreversible parts. The irreversible part is described by a new extended Preisach diagram and the reversible part by a Langevin function. Satisfactory agreement with experiment has been obtained.
The 270 nm absorption spectra of thioformamide, CHSNH 2 and CHSND 2 , have been photographically recorded under conditions of long path length (88 m) and moderate resolution (7.5 Å/mm). The absorption was assigned to the electron promotion, n S → π* (CS), and to the electronic transition, [Formula: see text]. The spec…
High-resolution adiabatic calorimetry has been used for the study of the liquid_crystal phase transitions in mixtures of 4-n-hexyloxyphenyl-4″-n-octyloxybenzoate (), 4-n-hexyloxy-phenyl-n-decyloxybenzoate () and 4-n-hexyloxyphenyl-4″-n-dodexyl-oxybenzoate () with emphasis on the vicinity of the NAC (nematic-smectic A-…
N‐Trifluormethylformamid 1 bzw. das Hexahydropyrrolo[3,4‐d]imidazol 2 sind die Produkte der Titelreaktionen. 1 ist eine bei 116°C unzersetzt destillierbare Flüssigkeit und liegt im Unterschied zu N‐Methylformamid in unpolaren Solventien bevorzugt als E‐Isomer vor. Die praktisch quantitative Bildung von 2, dessen Struk…
Abstract Thirty‐five PVC formulations were compounded initially from which selected nontoxic formulations were subjected to studies in changes of mechanical, optical, migratory, viscosity, and toxicity properties due to gamma irradiation to 2.5 M rads. Degree of discoloration was found to vary from negligible to inten…
A mathematical treatment of the electrochemical method of hydrogen permeation is presented which gives an equation more comformable to the experimental permeation‐time transients. To verify the equation, a set of permeation‐time transients of steel membrane under various potential was determined. The meanings of the p…
Abstract The identification of office copier machines has been simplified by the computerization of their class characteristics. The class characteristics examined are paper type, type of toner, reduction/enlargement capabilities, paper supply, presence of identifying marks, fusion method, and color capabilities. Thes…
Abstract Novel poly(enonsulfides) were prepared with inherent viscosities as high as 1.35 dL/g by nucleophilic addition of various aromatic dithiols to 1,1′‐(1,3‐ or 1,4‐phenylene)bis(3‐phenyl‐2‐propyn‐1‐one) in m ‐cresol at 25–40°C. A tough clear yellow film with a tensile strength of 11,300 psi and a tensile modulus…
The angular characteristics of transmission gratings are studied for the case when three parameters, namely the dielectric-constant modulation, the average dielectric constant and the grating vector vary with distance in the grating. The diffraction efficiency is worked out with the aid of a coupled-wave theory for li…
A layer structural complex magnetic refrigerant, which is suitable for the Ericsson cycle, satisfying the Carnot principle, has been investigated. Above ∼ 15 K, since the thermal agitation energy and the lattice entropy increase considerably, the ferromagnetic material has to be used for the refrigerant in the magneti…
The lamellar mesophase occurring in the system water aerosol OT (AOT) has been studied by combining nuclear magnetic resonance methods, such as deuterium quadruple measurement (D-NMR) and pulsed field gradient (PFG-NMR), with optical microscopy. At low AOT content the mesophase shows a biaxial character and consists o…
Second order nonlinear polarizabilities, α(2), were measured for various cyano-substituted aromatic (phenyl, biphenyl, terphenyl and phenylpyrimidine) molecules. The largest nonlinearity was found in cyano-biphenyl compounds, indicating that ring twisting may be causing a decrease in terphenyl nonlinear polarizability…
A study has been made of mill-annealed and cold-worked duplex Dalmine D22 and D25 stainless steels (75 and 140 ksi) and of cold-worked superaustenitic Dalmine D28-32 steel (110 ksi). The materials have been tested under conditions typical of oil and natural gas wells operating in a severe environment. The effect of en…
Commercial 1500 Oe iron particles were studied for environmental stability. The powders were subjected to different environmental conditions up to six months to determine the effects of temperature, humidity and air/nitrogen on the stability of the particles. Results showed that long term stability of iron particles w…
The accumulation of 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) in rat brain has been examined after probenecid infusion over 8 h. At plasma probenecid concentrations of 200-400 micrograms mL-1 a steady state level in the accumulation of 5-HIAA and HVA was achieved, the increase above the endogenou…