Error Free Butcher Algorithms for Linear Electrical Circuits

In this paper, an error‐free Butcher algorithm is introduced to study the singular system of a linear electrical circuit for time invariant and time varying cases. The discrete solutions obtained using Runge‐Kutta (RK)‐Butcher algorithms are compared with the exact solutions of the electrical circuit problem and are found to be very accurate. Stability regions for the single term Walsh series (STWS) method and the RK‐Butcher algorithm are presented. Error graphs for inductor currents and capacitor voltages are presented in a graphical form to show the efficiency of the RK‐Butcher algorithm. This RK‐Butcher algorithm can be easily implemented in a digital computer for any singular system of electrical circuits.     

Algorithm to predict dry-band arcing in fiber-optic cables

Utilities frequently use ADSS (all dielectric self-supporting) fiber-optic cables installed on transmission lines 3-6 m below the high voltage conductors. Dry-band arcing occurs on the fiber-optic cables when the cables are polluted and wet. This has been assumed to cause cable failures. An equivalent circuit has been developed to represent the polluted fiber-optic cable in the high voltage environment. The objective of this paper is to present a novel numerical method that can be used to predict dry-band arcing in fiber-optic cables. KCL (Kirchoff's current law) is used to derive node point equations for the equivalent circuit. Forward elimination and backward substitution of node voltage is used to solve the equations. The effect of pollution, tower arrangement, and conductor sag is analyzed. The numerical method has speed advantages over circuit simulation methods. This method includes conductor sag, nonuniform pollution, and variable capacitance. This algorithm can be used to predict dry band arcing in fiber-optic cables     

In situ diagnostic capabilities for beam position and beam intensity monitoring at SyLMAND

SyLMAND, the Synchrotron Laboratory for Micro and Nano Devices at the Canadian Light Source, consists of a dedicated X-ray lithography beamline on a bend magnet port, and process support laboratories in a cleanroom environment. The beamline comprises a double mirror system with flat, chromium-coated silicon mirrors operated at varying grazing angles of incidence for spectral adjustment by high energy cut-off. We present in this paper, the in situ diagnostic components inside the vacuum vessel upstream and downstream of the mirrors that allow for monitoring the incident beam and the reflected beam after first, second, and both mirrors. Four fly wire systems are used for beam position monitoring and intensity measurements. Additionally, four detector plates mounted on and moving with the mirror bodies are used to determine the position of the mirror surfaces with respect to the beam. First experimental results verify the capabilities of the system by showing good agreement between measured and calculated data.     

Role of Bismuth incorporation on the structural and optical properties in BixIn35-xSe65 thin films for photonic applications

The present paper investigated the influence of Bi concentration on the structural, linear, and non-linear optical properties of thermally evaporated Bi_xIn_35-xSe₆₅ (x = 0, 5, 7, 10, 15 at %) thin films. The structural analysis by the XRD measurements showed the crystalline nature at 7 and 15% Bi while the other concentrations showed amorphous nature. The corresponding bonding change was analyzed by Raman spectroscopy. The optical study by UV-Vis spectroscopy showed the decrease in transmittance and an increase in absorbance property. The linear optical parameters such as absorption coefficient, extinction coefficient, optical density increased while skin depth decreased with Bi additives. The direct, as well as the indirect optical bandgap, decreased along with the decrease in the Tauc parameter. The variation is well explained on the basis of density of defect states by the Mott and Davis model. The non-linear refractive index and non-linear susceptibility increased significantly with Bi % which is good for non-linear optical applications. The static linear refractive index as calculated by the Dimirov and Sakha empirical relation showed an incremental behavior with Bi% concentration and satisfied Moss's rule. The surface structure and elemental concentration were analyzed by FESEM and EDX analysis. The result of the above investigation suggests that these materials can be used as an absorbing layer for several optoelectronic and photonic applications.     

1D and 2D structured mass-spring models with preload

In this paper, the objective is to enrich the existing 1D and 2D mass-spring models with physical accuracy as well as visual realism. It is found that using nonzero preloads on the springs is a necessary condition for the models to approximate their continuum counterparts. First, the parameters of the 1D mass-spring model of a beam are derived based on pure bending and axial action. It is proved that the mass-spring model with this set of parameter has correct characteristics of resistance against lateral displacement, which is one of the most important aspects of the accuracy of the 1D mass-spring model. Then, the method is extended to the 2D mass-spring models of the continuum plate with two different mesh structures. The mass-spring model with equilateral triangle meshes is shown to be physically more accurate than that with rectangular meshes. Finally, the physical accuracy that the mass-spring models with preload can achieve is investigated under different load conditions by comparison with the finite element method (FEM) to demonstrate the efficacy of our approach.     

Design of reconfigurable coupled-serial-chain-based manipulation assistive aids

Our goal is to design a reconfigurable single degree-of-freedom (dof) articulated manipulation assistive aid, whose end-effector is required to closely approximate a series of constrained planar paths. To this end, we investigate the viability of the coupled-serial-chain configuration manipulator design created by constraining the relative rotations of a revolute-jointed serial-chain manipulator with linear cable–pulley couplings. The forward kinematics equations take the form of a finite trigonometric series in terms of the input crank rotations. Our proposed Fourier-based synthesis method exploits this special structure to facilitate the design synthesis of such manipulators. We then examine design enhancements, to permit this manipulator to be reconfigured for multiple sets of constrained end-effector tasks, by controlled variation of the principal structural parameters. Particular attention is paid to the creation of a physical prototype, which facilitates such reconfiguration.     

Assuring Timeliness in an e-Science Service-Oriented Architecture

An improvement to public-resource e-science portals shows promise in solving a well-known dilemma: how to dynamically discover a provider PC that is ready to deliver computing power when the scientific community requires it.     

Darzen's glycidic ester condensation reaction on poly(N-vinyl pyrrolidone)

About 38% conversion of carbonyl groups into epoxy functions in the molecular chain of poly(N-vinyl pyrrolidone) using chloracetamide results in the decreased viscosity of the product. De-epoxidation of the epoxy groups introduced shows the most contributing factor towards decreased viscosity is epoxy function.