Application of the Jones calculus for Gaussian beams in uniaxial crystals

Following our recent approach in which the Jones matrix calculus was applied to a modulated double-refracted and partially interfering light beam propagating in a homogeneous electro-optic crystal [J. Opt. Soc. Am. A21, 132 (2004)], we generalize the method for any distribution of the light intensity. Special attention is paid to Gaussian, flat-topped Gaussian, and quasi-Gaussian beams for which the intensity of the light emerging from the optical system is found analytically. Application of the method to an optical system with an electro-optic crystal is described.     

Ionization equilibria of nickel(II) bromide in acetonitrile solutions

Uv and visible absorption spectra and the molar conductance curve of NiBr₂ in acetonitrile solution have been determined at 25°C. Equilibrium concentrations and formation constants of the consecutive NiBr⁺, NiBr⁰₂, and NiBr^?₃, complexes have been calculated from the spectrophotometric results making use of the isosbestic points found in an auxiliary study of three-component solutions with variable Br^?:Ni(II) mole ratio. The existence of NiBr⁺ in the form of the [NiBrL₅]⁺ pseudooctahedral complex, and that of NiBr^?₃ in the form of the [NiBr₃L]^? pseudotetrahedral complex is inferred, while the nature of NiBr⁰₂ remains unclear.     

Processing,suitability and nutritive value of field bean seeds after germination

An attempt was made to obtain hydrolysates from field bean seeds after germination. The activity of native proteolytic enzymes, ascorbic acid and phytate phosphorus contents, as well as the activity of proteolytic enzyme inhibitors were studied, as influenced by seed steeping, water acidity and aerating conditions. Germinated field bean seeds were found to be suitable for hydrolysate production. The enzyme activity, as well as the contents of compounds responsible for the nutritive value of seed was determined and depended on germinating conditions.     

The effect of system parameter variations on natural frequencies

In the paper the relationships between variations of mass and stiffness matrices of system and variation of natural frequencies vector are analysed. Results are applied to finite element method and to stiff finite element method. The example of influence of masses and mass inertia moments variations of support beam on its natural frequencies illustrates the analysis.     

Some contributions to the theory of flow of fluids through porous deformable media

Summary The present paper is based onBiot's theory of flow of fluids through a porous deformable medium. The presence of a distribution of sources of fluids in the medium gives rise to an additional term in the generalizedDarcy's law. The present note is concerned with solutions of the displacement equations ofBiot's theory for the case of fluid sources. The regular solution of these equations is given in terms of special functions. The singular solution — connected with the action of fluid sources — is obtained with the aid of the principle of reciprocity of displacements.

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Zusammenfassung Die vorliegende Arbeit benützt dieBiotsche Theorie der Flüssigkeitsströmung durch ein poröses deformierbares Medium. Das Vorhandensein einer Quellverteilung gibt Anlaß zu einem zusätzlichen Glied im verallgemeinertenDorcyschen Gesetz. Für diesen Fall werden Lösungen derBiotschen Verschiebungs-gleichungen angegeben. Die reguläre Lösung wird in speziellen Funktionen angegeben. Die singuläre Lösung — mit den Flüssigkeitsquellen verknüpft — wird mit Hilfe der Reziproxität der Verschiebungen erhalten.

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Dynamic axial crushing of square tubes

Eighty-four dynamic tests on thin-walled square steel tubes having two different cross-sections with c/h = 30.25 and c/h = 32.18 and various lengths were crushed axially on a drop hammer rig. Approximate theoretical predictions were developed for the axial progressive crushing of square box columns using a kinematically admissible method of analysis. This theoretical study predicts four deformation modes which govern the behaviour for different ranges of the parameter c/h. New asymmetric deformation modes were predicted theoretically and confirmed in the experimental tests. These asymmetric modes cause an inclination of a column which could lead to collapse in the sense of Euler even for relatively short columns. The effective crushing distance is considered in the approximate theoretical analysis together with the influence of material strain rate sensitivity, which is important for steel even when the loadings are quasi-static. The simple equations presented herein for the design of axially crushed spuare box columns give reasonable agreement with the corresponding experimental results.     

Spontaneous formation of gold microplates during reduction‐coupled removal of noble metals using Dowex M4195 resin

The present work reports the novel phenomenon of spontaneous formation of gold microplates. The effect is observed as a consequence of , , , and sorption on the Dowex M4195 resin. Therefore an attempt to explain the phenomenon mechanism is made. The research is covering sorption, kinetic and thermodynamic studies. The shapes of formed gold single plates are determined. The uptakes of Au(III), Pt(IV), Pd(II), and Re(VII) tests have been conducted using a batch method from single‐component metals solutions in 0.1M HCl. The sorption‐reduction phenomenon has been assessed by executed SEM, FTIR, XRD, and XPS studies. The greatest sorption capacity, combined with reduction‐coupled removal phenomenon, has been achieved for gold (5.5 mmol Au·g^?1 at 9°C). Executed SEM and XRD analyzes prove formation of gold single crystals during present process, furthermore reduction of rhenium is indicated by XPS analysis. Based on the obtained FTIR and Raman's spectra, the reduction phenomenon is probably followed by resins’ functional groups oxidation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42425.     

The sensor effect tetrahedron: an extended transducer space

A visualisation of a four-dimensional space called an information and energy tetrahedron is introduced in the paper. This model of energy and information could be found useful by designers and developers of new measuring devices as well as in the analysis of measurement and instrumentation systems. The tetrahedron concept is an extension of the idea of a three dimensional transducer space first presented more than 30 years ago. By taking account of the interference sources within the range of possible energy forms it extends the three dimensional predecessor, which did not encompass these effects. To obtain this extended tetrahedron model, the sensor is viewed from its boundary perspective using the principles of systems engineering developed for application in measuring systems. When this approach is applied to sensors it is shown that they may be reduced to systems influenced by three classes of inputs. These inputs, which consist of the information borne by the measurand in its specific energy form, the support energy form and the contaminating information and energy forms, are shown to constitute what is called the input triangle in the paper. The system output, which is an information bearing energy form, provides an axis normal to the plane formed by the input triangle. All of the axes are drawn based upon the COMETMAN acronym to represent the diversity of possible energy domains. A summary of different ways of classifying energy forms or domains, which is given in the paper, allows these different methods of grouping to be compared. The application of the sensor effect tetrahedron is placed within the context of measurement by means of the three interfaces between humans, machines and their working environment. Introducing extrinsic and intrinsic boundaries permits the link between sensors and formal metrological components to be established. In this way the paper can help to provide a deep perception of sensors.