Invariant kinetic parameters of dyeing

Based on isothermal exhaustion curves recorded at various temperatures, the possibility of describing numerically the uptake profile of a dyestuff has been investigated. Since the exhaustion process is a complex one, its kinetic parameters depend on the experimental conditions and cannot be used to characterise a group of curves. The alternative method proposed in this study is the use of invariant kinetic parameters for describing the exhaustion of a dyestuff in a dyeing system under various conditions. The concepts have been applied to the exhaustion of two reactive dyestuffs on cotton. The results show that all the isothermal exhaustion curves of a dyeing system can be described by a unique group of three parameters, n _i, E _i and A _i.     

L-wrappers: concepts,properties and construction

In this paper, we propose a novel class of wrappers (logic wrappers) inspired by the logic prog- ramming paradigm. The developed Logic wrappers (L-wrapper) have declarative semantics, and therefore: (i) their specification is decoupled from their implementation and (ii) they can be generated using inductive logic programming. We also define a convenient way for mapping L-wrappers to XSLT for efficient processing using available XSLT processing engines.     

Computation of Core Losses in Electrical Machines Using Improved Models for Laminated Steel

Two new models for specific power losses in cold-rolled motor lamination steel are described together with procedures for coefficient identification from standard multifrequency Epstein or single sheet tests. The eddy-current and hysteresis loss coefficients of the improved models are dependent on induction (flux density) and/or frequency, and the errors are substantially lower than those of conventional models over a very wide range of sinusoidal excitation, from 20 Hz to 2 kHz and from 0.05 up to 2 T. The model that considers the coefficients to be variable, with the exception of the hysteresis loss power coefficient that has a constant value of 2, is superior in terms of applicability and phenomenological support. Also included are a comparative study of the material models on three samples of typical steel, mathematical formulations for the extension from the frequency to the time domain, and examples of validation from electrical machine studies.     

Valleytronics,Carrier Filtering and Thermoelectricity in Bismuth: Magnetic Field Polarization Effects

Valley polarization of multi‐valleyed materials is of significant interest for potential applications in electronic devices. The main challenge is removing the valley degeneracy in some controllable way. The unique properties of bismuth, including its anisotropic electronic structure and Dirac valley degeneracy, make this material an excellent system for valleytronics. It is demonstrated theoretically that the direction of an externally applied magnetic field in the binary‐bisectrix plane has a profound effect not only on the charge, but also on the thermal transport along the trigonal direction. The rotating field probes the electronic mass anisotropy and tunes the contribution from a particular Dirac valley in the electrical resistivity, Seebeck coefficient, and thermal conductivity at moderate temperatures and field strengths. It is further shown that the field polarization of the transport properties is accompanied by selective filtering of the carriers type providing further opportunities for thermoelectric transport control.     

Experimental studies on bulk tempering of 34CrNiMo6 steel

The class of steels for hardening and tempering, alloyed with chrome, nickel and molybdenum, standardized in Europe (four steel grades), USA (10 grades) and Russia (9 grades) is highly diversified and is especially interesting in the production of machine parts having an extremely large range of dimensions. The heat treatment features of these steels are particularly attractive: high bainitic hardenability and a good temperability etc. The correlation between the hardness achieved after high tempering on products made from these steels, their equivalent diameter and the heat and time parameters of tempering can be explained by means or Jominy samples test for products with equivalent diameters equal to or less than 100 mm, or by the results obtained through the method of simulation of oil cooling (Pavaras-Gheller method) for products with equivalent diameters higher than 100 mm. In this paper, based on experimental results, these correlations are customized for a steel group representative as is 34CrNiMo6.     

A critical review of pulse tube cryogenerator research

This paper is a synthesis of the state of the art in the design and theory of regenerative Pulse Tube cryogenic systems. A general outlook of the functional principles and of the processes occurring in these cryogenic systems is given. The main irreversibility sources are analyzed. A review of the important contributions on the subject, likely to improve the constructional and functional characteristics, is then presented, along with the evaluation of their scientific foundation.     

Poly-phenothiazine derivative-modified glassy carbon electrode for NADH electrocatalytic oxidation

Electropolymerization of a new phenothiazine derivative (bis-phenothiazin-3-yl methane; BPhM) on glassy carbon (GC) electrode generates a conducting film of poly-BPhM, in stable contact with the electrode surface. The heterogeneous electron-transfer process corresponding to the modified electrode is characterized by a high rate constant (50.4 s⁻¹, pH 7). The GC/poly-BPhM electrode shows excellent electrocatalytic activity toward NADH oxidation. The rate constant for catalytic NADH oxidation, estimated from rotating disk electrode (RDE) measurements and extrapolated to zero concentration of NADH, was found to be 9.4 × 10⁴ M⁻¹ s⁻¹ (pH 7). The amperometric detection of NADH, at +200 mV vs. SCE, is described by the following electroanalytical parameters: a sensitivity of 1.82 mA M⁻¹, a detection limit of 2 μM and a linear domain up to 0.1 mM NADH.     

A critical view on transport and entanglement in models of photosynthesis

We revisit critically the recent claims, inspired by quantum optics and quantum information, that there is entanglement in the biological pigment-protein complexes, and that it is responsible for the high transport efficiency. While unexpectedly long coherence times were experimentally demonstrated, the existence of entanglement is, at the moment, a purely theoretical conjecture; it is this conjecture that we analyse. As demonstrated by a toy model, a similar transport phenomenology can be obtained without generating entanglement. Furthermore, we also argue that, even if entanglement does exist, it is purely incidental and seems to play no essential role for the transport efficiency. We emphasize that our paper is not a proof that entanglement does not exist in light-harvesting complexes-this would require a knowledge of the system and its parameters well beyond the state of the art. Rather, we present a counter-example to the recent claims of entanglement, showing that the arguments, as they stand at the moment, are not sufficiently justified and hence cannot be taken as a proof for the existence of entanglement, let alone of its essential role, in the excitation transport.     

Analysis and design of a two-speed single-phase induction motor with 2 and 18 pole special windings

The motor presented employs multiple independent windings for operation with two very different pole numbers. The 18-pole field is produced with a symmetrical three-phase winding connected in a Steinmetz arrangement to a single-phase supply. A unified analysis method has been developed and used to demonstrate the equivalence of a Steinmetz delta or star connection with a main and auxiliary winding of a single-phase motor. The method has been experimentally validated and also included are some specific motor design considerations.     

Absorption Efficiency of Traveling Wave Photodetectors in Superconducting Fiber Plasmon–Polariton Optical Waveguides

By using an analytical model and a finite element method, we investigate a new, very sensitive, superconducting traveling wave photodetector made by an optical fiber, which includes a high index layer (LaAlO₃) with small losses, a metallic (gold) layer, and two active superconducting layers (YBCO). While the fundamental guided degenerate mode HE₁₁ is highly confined in the interior YBCO layer, the plasmon non-degenerate mode TM₀₁ and plasmon degenerate mode HE₁₂ are tightly confined in the exterior superconducting layer. In our structure of the fiber with five layers (without a buffer layer), the imaginary parts of the HE₁₁, TM₀₁, HE₁₂ modes and the power absorption efficiency in superconducting layers are larger in comparison with that of a fundamental mode from a LaAlO₃?CYBCO?CAu planar waveguide. The confinement regimes of the light and the power absorption efficiency in superconducting layers can be optimized by only acting on the fiber geometry.