Rings In Series Research Articles

Shift of the maxima of the critical currents of different polarity relative to the zero magnetic flux along the flux axis in a superconducting asymmetric aluminum ring

We measured the rectification of an ac voltage in a structure of superconducting circularly-asymmetric aluminum rings in series, permeated with a magnetic flux and biased with a low-frequency alternating current (without a dc component). This rectification is due to the shift of the maxima of the critical currents of different polarity relative to the zero flux in opposite directions along the flux axis in the asymmetric ring. For the first time, we propose a model for a temperature-dependent phase shift equal to difference between dimensionless kinetic inductances of wide and narrow semirings having the same length and thickness. The shift is not zero in the case of different critical currents densities in both semirings. This is possible only in a situation of different critical temperatures of both semirings. The model describes well the temperature-dependent shift of the maxima of the critical currents, answers the long-standing mysterious challenge of the shift and removes extremely strange contradiction between the results of different measurements, previously found in circularly-asymmetric aluminum structures.

Optical Spectra of Oligofurans: A Theoretical Approach to the Transition Energies, Reorganization Energies, and the Vibronic Activity.

There is experimental evidence of high vibronic activity that accompanies the allowed transition between the ground state and the lowest electronic singlet excited state of oligofurans that contain two, three, and four furan rings. The absorption and emission spectra of the three lowest oligofurans measured at liquid nitrogen temperature show distinct fine structures that are reproduced using the projection-based model of vibronic coupling (with Dushinsky rotation included) parameterized utilizing either Density Functional Theory (DFT, with several different exchange-correlation functionals) or ab initio (CC2) quantum chemistry calculations. Using as a reference the experimental data concerning the electronic absorption and fluorescence for the eight lowest oligofurans, we first analyzed the performance of the exchange-correlation functionals for the electronic transition energies and the reorganization energies. Subsequently, we used the best functionals alongside with the CC2 method to explore how the reorganization energies are distributed among the totally symmetric vibrations, identify the normal modes that dominate in the fine structures present in the absorption and emission bands, and trace their evolution with the increasing number of rings in the oligofuran series. Confrontation of the simulated spectra with the experiment allows for the verification of the performance of the selected DFT functionals and the CC2 method.

The ontology of person-centered healthcare: Theoretical essentials to reground medicine within its humanistic framework. Part I - A centered concept of personhood: Some tools to conceptualise subjectivity

To address subjectivity, as a generally rooted phenomenon, other ways of visualisation must be applied than in conventional objectivistic approaches. Using ‘trees’ as operational metaphors, as employed in Arthur Cayley’s ‘theory of the analytical forms called trees’, one rooted ‘tree’ must be set beneath the other and, if such ‘trees’ are combined, the resulting ‘forest’ is nevertheless made up of individual ‘trees’ and not of a deconstructed mix of ‘roots’, ‘branches’, ‘leaves’ or further categories, each understood as addressable both jointly and individually. The reasons for why we have chosen a graph theory and corresponding discrete mathematics as an approach and application are set out in this first of our three articles. It combines two approaches that, in combination, are quite uncommon and which are therefore not immediately familiar to all readers. But as simple as it is to imagine a tree, or a forest, it is equally simple to imagine a child blowing soap bubbles with the aid of a blow ring. A little more challenging, perhaps, is the additional idea of arranging such blow rings in series, transforming the size of the soap bubble in one ring after the other. To finally combine both pictures, the one of trees and the other of blow rings, goes beyond simple imagination, especially when we prolong the imagined blow ring becoming a tunnel, with a specific inner shape. The inner shape of the blow ring and its expansion as a tunnel are understood as determined by discrete qualities, each forming an internal continuity, depicted as a scale, with the scales combined in the form of a glyph plot. The different positions on these scales determine their length and if the endpoints of the spines are connected with an enveloping line then this corresponds to the free space left open in the tunnel to go through it. Using so many visualisation techniques at once is testing. Nevertheless, this is what we propose here and to facilitate such a visualisation within the imagination, we do it step by step. As the intended result of this ‘juggling of three balls’, as it were, we end up with a concept of how living beings elaborate their principal structure to enable controlled outside-inside communication.

Properties of electron transmission through serially connected hexagonal nanorings

Transmission properties are investigated for a system of two-branch nanorings with two quantum dots per branch. The rings are connected serially by a linear segment, creating a chain of rings. Applying a tight-binding Hamiltonian method, the electron transmission properties are primarily studied. Multiple system parameters are varied to study their effects on the transmission spectrum. These parameters include the coupling to the leads in and out of the system, the coupling between rings, and the total number of rings in the system. Each of these parameters affect the transmission bandgap, the resonant transmission, and the number of resonance peaks per transmission band. By tuning the system-leads coupling to a particular value which produces a coupling match between the periodic ring system and the source and drain leads, a combination of interference and resonance effects results in a broad range of transparency, wherein the system shows full transmission over a range of energy values, independent of the number of rings in series.

Development of bellows and gate valves with a comb-type rf shield for high-current accelerators: Four-year beam test at KEK B-Factory

Since a comb-type rf shield was proposed in 2003 as a rf shield for future high-intensity accelerators, various types of bellow chambers and gate valves with this rf shield have been installed in the KEK B-Factory rings in series and tested with beams. Through beam tests to check the performance, a structural simplification has been tried in parallel. The temperatures of the bellow corrugations decreased by a factor of 3-6 compared to those with a conventional finger-type rf shield in most cases. The temperatures of the body of the gate valves also decreased by a factor of 2-5. These results demonstrated the availability of the comb-type rf shield. Although a discharge was observed in one simplified model, the latest model has shown no problem up to a stored beam current of 1.8 A (1.3 mA/bunch, 6 mm bunch length). Experiences with the comb-type rf shield in these four-year beam tests are reviewed here.

Spintronic single-qubit gate based on a quantum ring with spin-orbit interaction

In a quantum ring connected with two external leads the spin properties of an incoming electron are modified by the spin-orbit interaction resulting in a transformation of the qubit state carried by the spin. The ring acts as a one qubit spintronic quantum gate whose properties can be varied by tuning the Rashba parameter of the spin-orbit interaction, by changing the relative position of the junctions, as well as by the size of the ring. We show that a large class of unitary transformations can be attained with already one ring -- or a few rings in series -- including the important cases of the Z, X, and Hadamard gates. By choosing appropriate parameters the spin transformations can be made unitary, which corresponds to lossless gates.

The Novel Dependence of the Host-Guest Inclusion Properties on the Number of the Thiophene Rings in a New Host Series Based on Linearly Condensed Polythiophenes

Abstract A new host series for crystalline inclusion complexes, which were designed on the basis of linearly condensed polythiophenes as a rigid backbone, were prepared. The host guest (DMSO) composition and the conformation of the host molecule in the inclusion crystals exhibited a novel dependence on the number of the condensed thiophene rings.

Vernier fiber double-ring resonator using degenerate two-wave mixing

We propose the use of degenerate two-wave mixing in a Vernier optical fiber double-ring resonator which consists of two single-coupler fiber rings in series. With the degenerate two-wave mixing, the Vernier operation can be achieved. In consequence, the effective free spectral range increases significantly and the signal beam is amplified.

An Airborne Precipitation Cloud Particle Charge Measurement Device and Analysis System

A system is described for measurement and analysis of precipitation particle charge from an aircraft in the highly variable and harsh environment of a convective cloud. A compromise, practical instrument design enables particle charge and sign to be measured with concentrations up to 5 L−1. The system employs two induction rings in series; it is de-iced both on the electrostatic shield and internally. New techniques are described which enable rapid analysis of sequential charge data over a penetration period of 55 s, with rejection of spurious data pulses resulting from particle impaction.

The effect of the longitudinal stiffness of the testing machine on the strength of hardened cement paste

Tests were carried out to see whether the longitudinal stiffness of the testing machine had any effect on the strength and fracture toughness of hardened cement paste. Six different testing machines were studied; in addition, machine stiffness was varied by inserting proving rings in series with the specimens. It was found that machine stiffness has no significant effect on the compressive strength, the flexural strength, or the critical stress intensity factor.

ChemInform Abstract: INTRAMOLECULAR NUCLEOPHILIC DISPLACEMENT OF FLUORINE

Intramolecular nucleophilic displacement in organic fluorine compounds takes place if a fluorine atom is located in the molecule at such a distance from a nucleophilic functional group as to allow cyclization to three-membered rings (in aliphatic compounds only), five-membered rings, six-membered rings, and, exceptionally, seven- and polymembered rings (in aromatic series only). The nucleophilic functions can be hydroxyl groups of alcohols, enols, phenols and carboxylic acids, sulfhydryl groups, primary or secondary amino groups, and carbanionic carbon atoms. The reaction is common with aliphatic monofluorides and aromatic polyfluorides, and rare with geminal and trigeminal fluorides. Whereas in the aliphatic series it is usually an undesirable side-reaction, in the aromatic series it is useful as a means of synthesizing carbocyclic and heterocyclic polynuclear compounds.