Sulfides of the sym—Triazine Series as Oil—soluble Corrosion Inhibitors

The protective properties of I—40 industrial and M—11 motor oils containing N—substituted 2,4—diamino—6—alkylthio— and 2—amino—4,6—dialkylthio—sym—triazones as corrosion inhibitors are investigated. It is shown that some of these compounds are more effective than the industrial corrosion inhibitor Penazolin 10—16 — a mixture of 1,2—disubstituted imidazolines obtained by condensation of C₁₀—C₁₆ synthetic fatty acids ( SFA) with polyethylenepolyamines.     

Magnetic field hysteresis of critical currents in Bi(2223)/Ag tapes and a way to overcome it

Experiments showing hysteresis of critical currents versus the external magnetic field I_c(B_e) were performed with two multifilamentary Bi(2223)/Ag tapes. The I_c(B_e) hysteresis is observable in the transversal as well as in the longitudinal orientation of the long axis of the tape with respect to the magnetic field. Based on the idea that the hysteresis is the effect of trapped flux in a network of well-connected current paths, a way to overcome this effect has been proposed and experimentally verified. The induced frozen-in screening currents are split into several parallel current patterns by cycling the external magnetic field around the adjusted value. Using the proposed method, the ‘neutral’ I_c(B_e) characteristics have been found. Approximate calculations of the penetration depth of the trapped flux show that the network of well-connected current paths could be formed by several disk-shaped grains (≈ Φ8 × 0.4 μ) stacked into more or less axially ordered (quasi cylindrical) colonies of average dimensions estimated to ≈ Φ8 × 4 μm.     

Use of electric power in glass melting

The advantages and disadvantages of electric furnaces for melting frits and enamels and glasses for special applications were examined. It was shown that low-efficiency electric furnaces are more economical than furnaces heated by organic fuel. The main advantage of electric furnaces is the reduction in harmful emissions.Translated from Steklo i Keramika, Nos. 3–4, pp. 8–10, March–April, 1994.     

Duality transformations for general bi-isotropic (nonreciprocalchiral) media

The transformation is defined to leave a given bi-isotropic medium invariant, whence it is self-dual in this transformation. It is shown that duality transformations always exist in pairs, labeled as left-hand and right-hand transformations. Self-dual fields are seen to be generalizations of the wave fields E± applied in the analysis of reciprocal chiral media. It is demonstrated that plane wave propagation and reflection problems in bi-isotropic media can be solved easily in terms of self-dual field decompositions. Nonreciprocity is seen to give rise to effects like polarization rotation in reflection, which cannot be interpreted in terms of reciprocal chiral media     

Depth resolution calculations for heavy-ion microbeam RBS analysis

A detailed study has been made on the use of MeV heavy ions (Z₁ = 6–8) for microbeam Rutherford backscattering (RBS) analysis, to improve the depth resolution of this technique. The algorithm for determination of the depth resolution was created and applied to the Zagreb microbeam facility. Theoretical estimates of depth resolution for C and O ion RBS analysis of thin oxide films and semiconductors, using annular silicon surface barrier detector (SSBD), are compared to those for proton backscattering analysis. Depth resolution in certain cases may be improved by increasing the heavy-ion energy. Therefore, by the proper choice of the heavy ion and the heavy-ion energy, the depth resolution may be improved, maintaining the efficiency of the RBS method.     

The complex role of perceptual organization in visual display design theory.

Two experiments were performed to test and extend the current 'emergent features' approach to display design for dynamic failure detection tasks. It was predicted that a display whose emergent features were well-mapped to goal-relevant task invariants would lead to better failure detection performance than either of two alternative displays. Contrary to prediction. Experiment 1 showed no differences in failure detection speed or accuracy across displays. The reason for this may have been that subjects did not discover the mapping between the mathematical properties of the task and the emergent feature, so in Experiment 2 subjects were explicitly instructed about the mapping and were advised on how to use the display geometry to help their performance. A significant difference in failure detection speed emerged, but the display supporting fastest performance was not the one with the well-mapped emergent feature. These results suggest that alternative perceptual organizational factors were at work which overpowered the intended effect. The results also underscore the difficulty of developing a theory of display design, and their impact on current theories is outlined.     

Space-domain method of moments solution for a strip on a dielectricslab

This paper presents a space-domain method of moments (MoM) solution to the problem of a strip dipole on a dielectric slab. The solution involves the use of a special junction basis function which models the nearly singular polarization currents in the vicinity of the strip/dielectric junction