Biorthogonal series method for Oseen type flows

A biorthogonal series method is developed to solve Oseen type flow problems. The theory leads to a new set of eigenfunctions for a specific class of linear non-selfadjoint operators containing the biharmonic one. These eigenfunctions differ from those given earlier in the literature for the biharmonic operator. The method is applied to the problem of thermocapillary flow in a cylindrical liquid bridge of finite length with axial through flow. Flow and temperature distributions are obtained at leading order of an expansion for small surface tension Reynolds number and Prandtl number. Another related problem considered is that of cylindrical cavity flow. Solutions for both cases are presented in terms of biorthogonal series. The effect of axial through flow on velocity and temperature fields is discussed by numerical evaluation of the truncated analytical series. The presence of axial through flow not only convectively shifts the vortices induced by surface forces in the direction of the through flow, but also moves their centers toward the outer cylindrical boundary. This process can lead to significantly asymmetric flow structures.

Evaluation of interfacial frictional resistance

Three distinct mechanisms — sliding, bonding and bearing — for the mobilisation of interfacial friction have been identified. In the light of these mechanisms, the effect of variation in reinforcement parameters, such as extensibility, flexibility and hardness on mobilisation of interfacial friction, and the mechanisms themselves has been examined. The influence of boundary effects of apparatus on the interfacial friction has been discussed and a method of estimating the same in a pull-out box has been proposed.

Nutritional evaluation of silage made from the toxic weed parthenium hysterophorus in animals

After ensilation, the toxic Compositae weed Parthenium hysterophorus was devoid of the toxic principle parthenin. Laboratory-scale ensilation indicated that no parthenin was detectable after 5 wk of anaerobic fermentation. For animal feeding studies, silage was made on a large scale from Parthenium mixed with maize or from Parthenium alone. Crossbred bull and buffalo bull calves were fed diets containing the silages, or control diet without silage, for 12 wk. The animals consumed both silages with relish, and body weight gains of silage-fed calves did not differ from those of the controls. The digestibilities of dry matter, fibre and nitrogen-free extract were greater with the control diet, but the biological value of proteins tended to be greater with the silage-containing diets. Haematological studies indicated no significant differences between experimental and control groups in selected parameters, except for a reduction in blood urea nitrogen in the animals fed silage. The possible causes for these biochemical alterations are discussed. Since the nutritive value of Parthenium silage compares favourably with the standard diet, and Parthenium seeds collected from the silage did not germinate, we suggest that ensilation can be used as an additional method in the containment and eradication of these plants, which grow wild in India.

Positional Consensus of Multi-Agent Systems Using Linear Programming Based Decentralized Control with Rectilinear Decision Domain

In this paper we develop a Linear Programming (LP) based decentralized algorithm for a group of multiple autonomous agents to achieve positional consensus. Each agent is capable of exchanging information about its position and orientation with other agents within their sensing region. The method is computationally feasible and easy to implement. Analytical results are presented. The effectiveness of the approach is illustrated with simulation results.

Performance analysis of subspace based method for source localization in shallow water

The present paper aims at studying the performance characteristics of a subspace based algorithm for source localization in shallow water such as coastal water. Specifically, we study the performance of Multi Image Subspace Algorithm (MISA). Through first-order perturbation analysis and computer simulation it is shown that MISA is unbiased and statistically efficient. Further, we bring out the role of multipaths (or images) in reducing the error in the localization. It is shown that the presence of multipaths is found to improve the range and depth estimates. This may be attributed to the increased curvature of the wavefront caused by interference from many coherent multipaths.

Synthesis, spectral characterization and in vitro microbiological evaluation of novel glyoxal, biacetyl and benzil bis-hydrazone macrocyclic Schiff bases and their Co(II), Ni(II) and Cu(II) complexes

A series of binuclear Co(II), Ni(II) and Cu(II) complexes were synthesized by the template condensation of glyoxal, biacetyl or benzil bis-hydrazide, 2,6-diformyl-4-methylphenol and Co(11), Ni(II) or Cu(II) chloride in a 2:2:2 M ratio in ethanol. These 22-membered macrocyclic complexes were characterized by elemental analyses, magnetic, molar conductance, spectral, thermal and fluorescence studies. Elemental analyses suggest the complexes have a 2:1 stoichiometry of the type (M2LX2]center dot nH(2)O and Ni(2)LX(2)2H(2)O]center dot nH(2)O (where M = Co(II) and Cu(II); L = H2L1, H2L2 and H2L3; X = Cl; n = 2). From the spectroscopic and magnetic studies, it has been concluded that the Co(11) and Cu(11) complexes display a five coordinated square pyramidal geometry and the Ni(II) complexes have a six coordinated octahedral geometry. The Schiff bases and their metal complexes have also been screened for their antibacterial and antifungal activities by the MIC method. (C) 2011 Elsevier Ltd. All rights reserved.

Evaluation and improvement of total transfer capability - A case study

With deregulation, the total transfer capability (TTC) calculation, which is the basis for evaluating available transfer capability (ATC), has become very significant. TTC is an important index in power markets with large volume of inter-area power exchanges and wheeling transactions taking place on an hourly basis. Its computation helps to achieve a viable technical and commercial transmission operation. The aim of the paper is to evaluate TTC in the interconnections and also to improve it using reactive optimization technique and UPFC devices. Computations are carried out for normal and contingency cases such as single line, tie line and generator outages. Base and optimized results are presented, and the results show how reactive optimization and unified power flow controller help to improve the system conditions. In this paper repeated power flow method is used to calculate TTC due to its ease of implementation. A case study is carried out on a 205 bus equivalent system, a part of Indian Southern grid. Parameters like voltage magnitude, L-index, minimum singular value and MW losses are computed to analyze the system performance.

Fabrication and evaluation of 450 F electrochemical redox supercapacitors using inexpensive and high-performance, polyaniline coated, stainless-steel electrodes

Redox supercapacitors using polyaniline (PANI) coated. stainless-steel (SS) electrodes have been assembled and characterized. PANI has been deposited on SS substrate by a potentiodynamic method from an acidic electrolyte which contains aniline monomer. By employing stacks of electrodes, each with a geometrical area of 24 cm(2), in acidic perchlorate electrolyte, a capacitance value of about 450 F has been obtained over a long cycle-life. Characterization studies have been carried out by galvanostatic charge-discharge cycling of the capacitors singly, as well as in series and parallel configurations. Various electrical parameters have been evaluated. Use of the capacitors in parallel with a battery for pulse-power loads. and also working of a toy fan connected to the charged capacitors have been demonstrated. A specific capacitance value of about 1300 F g(-1) of PANI has been obtained at a discharge power of about 0.5 kW kg(-1). This value is several times higher than those reported in the literature for PANI and is, perhaps, the highest value known for a capacitor material. The inexpensive SS substrate and the high-capacitance PANI are favorable factors for commercial exploitation. (C) 2002 Elsevier Science B.V. All rights reserved.

Microwave heating in multiphase systems: evaluation of series solutions

The 1D electric field and heat-conduction equations are solved for a slab where the dielectric properties vary spatially in the sample. Series solutions to the electric field are obtained for systems where the spatial variation in the dielectric properties can be expressed as polynomials. The series solution is used to obtain electric-field distributions for a binary oil-water system where the dielectric properties are assumed to vary linearly within the sample. Using the finite-element method temperature distributions are computed in a three-phase oil, water and rock system where the dielectric properties vary due to the changing oil saturation in the rock. Temperature distributions predicted using a linear variation in the dielectric properties are compared with those obtained using the exact nonlinear variation.

Twisted aromatics, 9-anthryl and 1-pyrenyl terpyridines organize into novel multi-directional 'ladder-like' motifs in the solid state

9-Anthryl and 1-pyrenyl terpyridines (1 and 2, respectively), key precursors for the design of novel fluorescent sensors have been synthesized and characterized by H-1 NMR, mass spectroscopy and X-ray crystallography. Twisted molecular conformations for each 1 and 2 were observed in their single crystal structures. Energy minimization calculations for the 1 and 2 using the semi-empirical AM1 method show that the 'twisted' conformation is intrinsic to these systems. We observe interconnected networks of edge-to-face CH...pi interactions, which appear to be cooperative in nature, in each of the crystal structures. The two twisted molecules, although having differently shaped polyaromatic hydrocarbon substituents, show similar patterns of edge-to-face CH...pi interactions.The presently described systems comprise of two aromatic surfaces that are almost orthogonal to each other. This twisted or orthogonal nature of the molecules leads to the formation of interesting multi-directional ladder like supramolecular organizations. A combination of edge-to-face and face-to-face packing modes helps to stabilize these motifs. The ladder like architecture in 1 is helical in nature. (C) 2002 Published by Elsevier Science B.V.

Site Characterization of Bangalore using Geophysical Method

A number of geophysical methods have been proposed for near-surface site characterization and measurement of shear wave velocity by using a great variety of testing configurations, processing techniques,and inversion algorithms. In particular, two widely-used techniques are SASW (Spectral Analysis of SurfaceWaves) and MASW (Multichannel Analysis of SurfaceWaves). MASW is increasingly being applied to earthquake geotechnical engineering for the local site characterization, microzonation and site response studies.A MASW is a geophysical method, which generates a shear-wave velocity (Vs) profile (i.e., Vs versus depth)by analyzing Raleigh-type surface waves on a multichannel record. MASW system consisting of 24 channels Geode seismograph with 24 geophones of 4.5 Hz frequency have been used in this investigation. For the site characterization program, the MASW field experiments consisting of 58 one-dimensional shear wave velocity tests and 20 two-dimensional shear wave tests have been carried out. The survey points have been selected in such a way that the results supposedly represent the whole metropolitan Bangalore having an area of 220 km2.The average shear wave velocity of Bangalore soils have been evaluated for depths of 5m, 10m, 15m, 20m, 25m and 30 m. The subsoil site classification has been made for seismic local site effect evaluation based on average shear wave velocity of 30m depth (Vs30) of sites using National Earthquake Hazards Reduction Program (NEHRP) and International Building Code (IBC) classification. Soil average shearwave velocity estimated based on overburden thickness from the borehole information is also presented. Mapping clearly indicates that the depth of soil obtained from MASW is closely matching with the soil layers in bore logs. Among total 55 locations of MASW survey carried out, 34 locations were very close to the SPT borehole locations and these are used to generate correlation between Vs and corrected “N” values. The SPT field “N” values are corrected by applying the NEHRP recommended corrections.

Integrated Reservoir Operation Modeling for Irrigation Systems - A Multi-Objective Approach

An integrated reservoir operation model is presented for developing effective operational policies for irrigation water management. In arid and semi-arid climates, owing to dynamic changes in the hydroclimatic conditions within a season, the fixed cropping pattern with conventional operating policies, may have considerable impact on the performance of the irrigation system and may affect the economics of the farming community. For optimal allocation of irrigation water in a season, development of effective mathematical models may guide the water managers in proper decision making and consequently help in reducing the adverse effects of water shortage and crop failure problems. This paper presents a multi-objective integrated reservoir operation model for multi-crop irrigation system. To solve the multi-objective model, a recent swarm intelligence technique, namely elitist-mutated multi-objective particle swarm optimisation (EM-MOPSO) has been used and applied to a case study in India. The method evolves effective strategies for irrigation crop planning and operation policies for a reservoir system, and thereby helps farming community in improving crop benefits and water resource usage in the reservoir command area.

Method of Design Through Structuring of Meanings

This research shows a new approach and development of a design methodology, based on the perspective of meanings. In this study the design process is explored as a development of the structure of meanings. The processes of search and evaluation of meanings form the foundations of developing this structure. In order to facilitate the use and operation of the meanings, the WordNet lexical database and an existing visualization of WordNet — Visuwords — is used for the process of meaning search. The basic tool used for evaluation process is the WordNet::Similarity software, measuring the relatedness of meanings in the database. In this way it is measuring the degree of interconnections between different meanings. This kind of search and evaluation techniques are later on incorporated into our methodology of the structure of meanings to support the design process. The measures of relatedness of meanings are developed as convergence criteria for application in the processes of evaluation. Further on, the methodology for the structure of meanings developed here is used to construct meanings in a verification of product design. The steps of the design methodology, including the search and evaluation processes involved in developing the structure of the meanings, are elucidated. The choices, made by the designer in terms of meanings are supported by consequent searches and evaluations of meanings to be implemented in the designed product. In conclusion, the paper presents directions for developing and further extensions of the proposed design methodology.

Fully Comprehensive Geometrically Non-Linear Dynamic Analysis of Multi-Body Beam Systems with Elastic Couplings

This paper is concerned with the dynamic analysis of flexible,non-linear multi-body beam systems. The focus is on problems where the strains within each elastic body (beam) remain small. Based on geometrically non-linear elasticity theory, the non-linear 3-D beam problem splits into either a linear or non-linear 2-D analysis of the beam cross-section and a non-linear 1-D analysis along the beam reference line. The splitting of the three-dimensional beam problem into two- and one-dimensional parts, called dimensional reduction,results in a tremendous savings of computational effort relative to the cost of three-dimensional finite element analysis,the only alternative for realistic beams. The analysis of beam-like structures made of laminated composite materials requires a much more complicated methodology. Hence, the analysis procedure based on Variational Asymptotic Method (VAM), a tool to carry out the dimensional reduction, is used here.The analysis methodology can be viewed as a 3-step procedure. First, the sectional properties of beams made of composite materials are determined either based on an asymptotic procedure that involves a 2-D finite element nonlinear analysis of the beam cross-section to capture trapeze effect or using strip-like beam analysis, starting from Classical Laminated Shell Theory (CLST). Second, the dynamic response of non-linear, flexible multi-body beam systems is simulated within the framework of energy-preserving and energy-decaying time integration schemes that provide unconditional stability for non-linear beam systems. Finally,local 3-D responses in the beams are recovered, based on the 1-D responses predicted in the second step. Numerical examples are presented and results from this analysis are compared with those available in the literature.

Polynomial Coefficient Based Multi-Tone Testing of Analog Circuits

Abstract—A method of testing for parametric faults of analog circuits based on a polynomial representaion of fault-free function of the circuit is presented. The response of the circuit under test (CUT) is estimated as a polynomial in the applied input voltage at relevant frequencies apart from DC. Classification of CUT is based on a comparison of the estimated polynomial coefficients with those of the fault free circuit. The method needs very little augmentation of circuit to make it testable as only output parameters are used for classification. This procedure is shown to uncover several parametric faults causing smaller than 5 % deviations the nominal values. Fault diagnosis based upon sensitivity of polynomial coefficients at relevant frequencies is also proposed.