Inductance Coefficient Research Articles

Robust feedback systems for resistive wall modes

The feedback stabilization of magnetohydrodynamic instabilities that grow on the resistive time scale of the chamber walls is an important issue for steady-state tokamaks. Constraints are derived on the inductance coefficients of the feedback system that will ensure that fixed amplification coefficients can be used to provide stability over the entire region in which feedback is in principle possible. Such feedback systems are called robust. Successful feedback is possible for systems that do not satisfy these constraints, but then the signs of the feedback coefficients will depend on the level of plasma instability.

SYMMETRIES OF NEUTRINO MIXING

Encouraged by the phenomenological success of the tri-bimaximal hypothesis, we postulate that the neutrino mass matrix in the lepton flavour basis is an S3 group matrix in the natural representation of S3. This immediately requires one neutrino to be trimaximally mixed, as suggested by the solar neutrino data. We go on to postulate that the charged-lepton mass matrix in the neutrino mass-basis is an S3 class matrix in the natural representation of the S3 class-algebra, leading to exact tri-bimaximal mixing which is compatible with data overall. The above two postulates are mutually consistent, and imply that the neutrino mass matrix in the flavour basis is an S3⊃S2 class operator, in the natural representation of the S3 group (the S2 being associated with mu-tau interchange). Thus the tri-bimaximal mixing matrix is seen to be closely related to the S3 group characters, and may be properly regarded as simply the table of induction coefficients for the [2]×[1]=[3]+[21] induced representation of S3.

A comprehensive method for the calculation of inductance coefficients of cage induction machines

In this paper, a new comprehensive method for the calculation of inductance coefficients of squirrel cage induction machine based on combined winding function approach (WFA) and magnetic equivalent circuit (MEC) is presented. By taking into account machine geometry, rotor skewing, stator and rotor slots effects and type of windings connection, this method is able to model most of the important features of an induction machine. The effects of each machine parameter on the inductance coefficients are verified. Also, effects of several rotor asymmetries on these inductances are shown. Simulation results are verified by more elaborate nonlinear finite element model and finally with experimental results.

On the matrices of capacitance and inductance coefficients for lossless homogeneous multiconductor transmission lines

Abstract. Using results from the theory of planar fields and complex functions it is shown that for lossless homogeneous multiconductor transmission lines the computation of the matrices of capacitance and inductance coefficients can be reduced to the solution of some special Dirichlet boundary value problems. Additionally, a function theoretic proof is given for the relationship LC = ϵµE between these matrices.

Inductive electromagnetic effects in solar current-carrying magnetic loops

Effects of electromagnetic inductive interactions in groups of slowly growing current-carrying loops are studied. Each loop is considered as an equivalent electric circuit with variable resistivity and inductive coefficients. These parameters depend on the geometry of the loop, its position with respect to neighboring loops, as well as on the plasma temperature and density in the magnetic tube. By means of such a model the process of generation of currents and temperature change in coronal loops moving relative to each other, and their dynamic interaction were studied. There are three main results of this analysis. First, the possibility of a relatively quick development of a significant longitudinal current in a rising and initially current-free magnetic loop is demonstrated. Second, the processes of fast, flare-like, plasma temperature increase in inductively connected growing loops with high enough currents, ~, as well as run-away electrons acceleration in the loops by inductive electric fields are modelled. And third, based on the analysis of a ponderomotoric interaction of current-carrying magnetic loops, conditions for their oscillations or a fast change of the loops inclination, possibly resulting in their coalescence and magnetic reconnection, are studied. The main characteristics of the oscillatory dynamics of a loop were calculated.

Permutation symmetry, tri-bimaximal neutrino mixing and the S3 group characters

We postulate that the neutrino mass matrix in the lepton flavour basis is an S3 group matrix in the natural representation of S3. This immediately requires one neutrino to be trimaximally mixed, as suggested by the solar neutrino data. We go on to postulate that the charged-lepton mass matrix in the neutrino mass-basis is an S3 class matrix in the natural representation of the S3 class-algebra, leading to exact tri-bimaximal mixing, which is compatible with data overall. The tri-bimaximal mixing matrix is seen to be closely related to the S3 character table, and is properly the S3⊃S2 table of induction coefficients, where the S2 corresponds to symmetry under μ–τ interchange in the lepton flavour basis.

Method for the ab initio calculation of intermolecular potentials of ionic clusters: Test on Rg–CO+, Rg=He, Ne, Ar

The interaction energy of a cationic complex A–B+ can be computed as the sum of the interaction energy of the neutral complex A–B and the geometry dependent difference in the ionization potentials of the complex A–B and the molecule B, with ionization potentials calculated by the outer valence Green’s function method. We test this method by computing the intermolecular potential energy of the complexes He–CO+, Ne–CO+, and Ar–CO+ for linear and T-shaped geometries. One-dimensional potential energy cuts were analyzed with emphasis on the asymptotic behavior. Results obtained by this method have been compared to interaction energies of the A–B+ complex computed directly by the partially spin-restricted single and double excitation coupled cluster method with perturbative triples. For the weakly bound complexes He–CO+ and Ne–CO+ the differences are only a few percent at small intermolecular distances but become significant for separations around the equilibrium distance and larger. Scaling the long range induction coefficients to match accurately known values significantly improves the agreement: the resulting interaction potentials are accurate to within a few percent at all intermolecular separations. For the Ar–CO+ complex the method produces less accurate results for small intermolecular distances but the binding in Ar–CO+ is very strong and for small R this system cannot be considered a weakly bound complex anymore.

A Luminescent Escherichia coli Biosensor for the High Throughput Detection of β-Lactams

A group-specific bioluminescent Escherichia coli strain for studying the action of beta-lactam antibiotics is described. The strain contains a plasmid, pBlaLux1, in which the luciferase genes from Photorhabdus luminescens are inserted under the control of the beta-lactam-responsive element ampR/ampC from Citrobacter freundii. In the presence of beta-lactams, the bacterial cells are induced to express the luciferase enzyme and three additional enzymes generating the substrate for the luciferase reaction. This biosensor for beta-lactams does not need any substrate or cofactor additions, and the bioluminescence can be measured very sensitively in real time by using a luminometer. Basic parameters affecting the light production and induction in the gram-negative model organism E. coli SNO301/pBlaLux1 by various beta-lactams were studied. The dose-response curves were bell shaped, indicating toxic effects for the sensor strain at high concentrations of beta-lactams. Various beta-lactams had fairly different assay ranges: ampicillin, 0.05-1.0 microg/ml; piperacillin, 0.0025-25 microg/ml; imipenem, 0.0025-0.25 microg/ml; cephapirin, 0.025-2.5 microg/ml; cefoxitin, 0.0025-1.5 microg/ml; and oxacillin, 25-500 microg/ml. Also, the induction coefficients (signal over background noninduced control) varied considerably from 3 to 158 in a 2-hour assay. Different non-beta-lactam antibiotics did not cause induction. Because the assay can be automated using microplate technologies, the approach may be suitable for higher throughput analysis of beta-lactam action.

ASYMPTOTIC BEHAVIOR OF THE INDUCTANCE COEFFICIENT FOR THIN CONDUCTORS

We study the asymptotic behavior of the inductance coefficient for a thin toroidal inductor whose thickness depends on a small parameter ε > 0. We give an explicit form of the singular part of the corresponding potential uε which allows to construct the limit potential u (as ε → 0) and an approximation of the inductance coefficient Lε. We establish some estimates of the deviation uε - u and of the error of approximation of the inductance. We show that Lε behaves asymptotically as ln ε, when ε → 0.

Low-Inductance Megavolt Pulse Generators for an Outdoor Setup

Pulse voltage generators (PVGs) for an outdoor facility generating 1.2- to 4.0-MV pulses have a low self-inductance due to such an arrangement of capacitors in the insulating supporting frame, at which the minimum distance between the terminals of the capacitors of two adjacent PVG stages is determined only by the size of the exterior insulation of the gas-filled switches in use. This helped to obtain an inductance coefficient of 2.5–3.5 μH/MV, which is comparable with that of oil-filled PVGs.

Self-inductance coefficient for toroidal thin conductors

We consider the inductance coefficient for a thin toroidal inductor whose thickness depends on a small parameter > 0. An explicit form of the singular part of the corresponding potential u is given. This allows to construct the limit potential u (as → 0) and an approximation of the inductance coefficientL . We establish some estimates of the deviation u − u and of the error of approximation of the inductance. The main result shows that L behaves asymptotically as ln , when → 0.

Complex Electroelasticity Potentials for Multiply Connected Plates with Holes and Cracks

An apparatus is developed for studying the electroelastic state of multiply connected anisotropic plates with holes and cracks. Basic relationships are obtained for the complex potentials and for the stress intensity and induction coefficients. A solution is given for plates with a finite number of holes and cracks.

Magnetic properties of R-Nd-Fe-B (R = Tb, Dy) and Nd-Fe-Co-B Alloys in the Range -80 to 250°C

The remanence, coercivity, and maximum energy product of R-Nd-Fe-B (R = Tb, Dy) and NdFe-Co-B alloys were studied in the range-80 to 250°C. Doping of Nd-Fe-B alloys with Tb and Dy was shown to increase coercivity and, accordingly, the temperature coefficient of magnetic induction. The introduction of 7-12 wt % Co raises the Curie temperature of the alloys, thereby improving their thermal stability.1 Ural State University, Yekaterinburg.

Inductance computation by incremental finite element analysis

The paper introduces the enhanced method (EIEM) for the accurate and efficient computation of nonlinear differential inductance coefficients. The EIEM has the following advantages: (i) only one analysis is required for any coefficient, self or mutual; (ii) first derivative evaluation; (iii) the current increment may be large; (iv) there is no need to evaluate the nonlinear magnetic energy, instead, an incremental energy is calculated according to a simple expression; (v) only load vectors should be computed, the stiffness matrix can be saved; (vi) if a direct solver is applied, additional matrix factorization is avoided. These advantages provide improved accuracy and computational efficiency. The paper outlines the new EIEM and illustrates it the example of a transformer.

Long-range dispersion and induction coefficients for the homodimers of Li 2, Na 2 and K 2

Long-range dispersion and induction coefficients for the homodimers of Li 2, Na 2, K 2 are evaluated in the L A L B M scheme using explicit formulae presented previously and numerical values of moments, polarizabilities and dispersion constants obtained from 2-term reduced spectra of the Kaiserslautern group. While induction coefficients are 5–8 times smaller than dispersion, induction anisotropies are always larger than the corresponding dispersion anisotropies for all homodimers.

Multifrequency piezoelectric composites: one-dimensional modeling

It has been proposed that multifrequency piezoelectric composites increase the bandwidth of the standard piezocomposite configurations. The geometrical approach consists of the use of piezoelectric elements with different width-to-thickness ratios in the same polymer matrix. A one-dimensional modeling of these new structures can be made, performing an homogenization of the overall composite parameters by linking Onoe's coupling mode theory with standard one-dimensional composite models. A strong approximation must be introduced to define a `virtual' c 13 elastic constant. The model accurately predicts the transducer behaviour of 2–2 standard piezocomposites with piezoceramic elements having a width-to-thickness ratio w: t between 0 and 0.8. In the case of double composites, the coupling between the different resonators, explained by a physical model, is made empirically introducing a mutual induction coefficient between the inductances of their respective equivalent circuits. The computed and experimental results show the usefulness of the double design.

An Analysis of the Consumption of Resources and Energy in Japanese Regions Using Interregional Input-Output Tables

Under the growing awareness of the global environmental issues, the Japanese Government has been enacting various laws for energy saving and material recycling to promote the formation of environment-friendly society.The input-output analysis is a useful tool to examine economic structural problems concerning the economic growth, the industrial structure and the environment. Several researches have been conducted to identify the efficiency of resources and energy consumption of Japanese industries using input-output analysis. However, we have few researches on the relationship between the industrial structure and the resources and energy consumption in Japanese regions.The aim of this paper is to identify the trends in the industrial structure and the consumption of resources and energy in Japanese regions using Interregional input-output tables for the period 1975-1990. The relationships between the industrial structure and the efficiency of resources and energy consumption in Japanese regions are examined by calculating various coefficients and analytical methods on regional economic linkage; the induction coefficients for resources and energy supply sectors; the resources and energy induction coefficients; the interregional input-output analysis.The analysis of induction coefficients for resources and energy supply sectors for eight Japanese regions has revealed the efficient use of oil and coal materials had been achieved during 1975-1990. However, the other sectors, such as the mining, the electricity and the gas and water supply had not made much progress.The reduction of resources and energy induction coefficients in terms of input structure factors (i.e. technological improvements) and the structure of final demand had been proceeded throughout the study period. However, the efficiency deteriorated in a few regions and industrial sectors under the economic growth during the bubble economy period.The feedback effects for resources and energy supply sectors using interregional input-output model had been weakened in tertiary sector, whereas strengthened in the manufacturing industries in the eastern part of Japan. The regional disparities in terms of feedback effects for resources and energy supply sectors had been reduced in both manufacturing and tertiary sectors.

Determination of the Parameters of High- T C RF SQUID from Its Small Signal Voltage-Frequency Characteristics

The present study is the extension of a recent theory of high-TC RF SQUIDs, operating in the presence of large thermal fluctuations. First, the explicit analytical expressions for the amplitudes of higher harmonics of the current circulating in a SQUID loop which are necessary for the determination of the junction critical current IC and the inductive coupling coefficient of the SQUID loop to its tank circuit, k2 , are found. Second, in order to find the junction resistance R with acceptable accuracy, the solution of Fokker–Plank equation to first order in parameter q = ωL/R, where ω is a bias frequency, L is a loop inductance, is obtained. These results allow one to derive the simple expressions for the determination of the junction critical current IC, its normal resistance R, and the inductive coupling coefficient of the SQUID loop to its tank circuit, k2 , from the experimental measured small signal voltage-frequency characteristics.

The induced representations of Brauer algebras and the Clebsch-Gordan coefficients of

Induced representations of from with are discussed. The induction coefficients (IDCs) or the outer-product reduction coefficients of with up to a normalization factor are derived by using the linear equation method. Weyl tableaux for the corresponding Gel'fand basis of SO(n) are defined. The assimilation method for obtaining Clebsch-Gordan coefficients of SO(n) in the Gel'fand basis for no modification rule involved couplings from IDCs of Brauer algebras is proposed. Some isoscalar factors of for the resulting irrep with are tabulated.

Luminescent bacterial sensor for cadmium and lead

A sensor plasmid was constructed by inserting the regulation unit from the cadA determinant of plasmid pI258 to control the expression of firefly luciferase. The resulting sensor plasmid pTOO24 is capable of replicating in Gram-positive and Gram-negative bacteria. The expression of the reporter gene as a function of added extracellular heavy metals was studied in Staphylococcus aureus strain RN4220 and Bacillus subtilis strain BR151. Strain RN4220(pTOO24) mainly responded to cadmium, lead and antimony, the lowest detectable concentrations being 10 nM, 33 nM and 1 nM respectively. Strain BR151(pTOO24) responded to cadmium, antimony, zinc and tin at concentrations starting from 3.3 nM, 33 nM, 1 μM and 100 μM, respectively. The luminescence ratios between induced and uninduced cells, the induction coefficients, of strains RN4220(pTOO24) and BR151(pTOO24) were 23–50 and about 5, respectively. These results were obtained with only 2–3 h incubation times. Freeze-drying of the sensor strains had only moderate effects on the performance with respect to sensitivity or induction coefficients.