Influence of surge impedance of the connecting lead in response time measurement of u.h.v. damped capacitive voltage dividers

In the determination of the response time of u.h.v. damped capacitive impulse voltage dividers using the CIGRE IMR-1MS group (1) method and the arrangement suggested by the International Electrotechnical Commission (the I EC square loop),the surge impedance of the connecting lead has been found to influence the accuracy of determination. To avoid this difficulty,a new graphical procedure is proposed. As this method uses only those data points which can be determined with good accuracy, errors in response-time area evaluation do not influence the result.

A Method of Evaluating Electrical Response of Solion Diodes

A method of evaluating the transient electrical response of a solion diode when excited by different current stimuli is given. This method is extended to obtain the transient response of the solion when connected in a circuit. To illustrate the utility of this method a circuit incorporating a solion diode has been analyzed.

Structural and dielectric behavior of pulsed laser ablated Sr(0.6)Ca(0.4)TiO(3) thin film and asymmetric multilayer of SrTiO(3) and CaTiO(3)

Homogeneous thin films of Sr(0.6)Ca(0.4)TiO(3) (SCT40) and asymmetric multilayer of SrTiO(3) (STO) and CaTiO(3) (CTO) were fabricated on Pt/Ti/SiO(2)/Si substrates by using pulsed laser deposition technique. The electrical behavior of films was observed within a temperature range of 153 K-373 K. A feeble dielectric peak of SCT40 thin film at 273 K is justified as paraelectric to antiferroelectric phase transition. Moreover, the Curie-Weiss temperature, determined from the epsilon'(T) data above the transition temperature is found to be negative. Using Landau theory, the negative Curie-Weiss temperature is interpreted in terms of an antiferroelectric transition. The asymmetric multilayer exhibits a broad dielectric peak at 273 K. and is attributed to interdiffusion at several interfaces of multilayer. The average dielectric constants for homogeneous Sr(0.6)Ca(0.4)TiO(3) films (similar to 650) and asymmetric multilayered films (similar to 350) at room temperature are recognized as a consequence of grain size effect. Small frequency dispersion in the real part of the dielectric constants and relatively low dielectric losses for both cases ensure high quality of the films applicable for next generation integrated devices. (C) 2011 Elsevier B.V. All rights reserved.

Estimation of Series Capacitance of a Transformer Winding Based on Frequency-Response Data: An Indirect Measurement Approach

A novel procedure to determine the series capacitance of a transformer winding, based on frequency-response measurements, is reported. It is based on converting the measured driving-point impedance magnitude response into a rational function and thereafter exploiting the ratio of a specific coefficient in the numerator and denominator polynomial, which leads to the direct estimation of series capacitance. The theoretical formulations are derived for a mutually coupled ladder-network model, followed by sample calculations. The results obtained are accurate and its feasibility is demonstrated by experiments on model-coil and on actual, single, isolated transformer windings (layered, continuous disc, and interleaved disc). The authors believe that the proposed method is the closest one can get to indirectly measuring series capacitance.

Frequency response analysis of layered ground in Ahmedabad during Bhuj earthquake

This paper presents the results of seismic response analysis of layered ground in Ahmedabad City during the earthquake in Bhuj on 26(th) January 2001. An attempt has been made to understand the reasons for the failure of multistoreyed buildings founded on soft alluvial deposits in Ahmedabad. Standard Penetration test at a site very close to the Sabarmati river belt was carried out for geotechnical investigations. The program SHAKE91, widely used in the field of earthquake engineering for computing the seismic response of horizontally layered soil deposits, was used to analyse the soil profile at the selected site considering the ground as one dimensional layered elastic system. The ground accelerations recorded at the ground floor of the Regional Passport Staff Quarters building, which is very close to the investigated site, was used as input motion. Also, Finite Element Analysis was carried out for different configurations of multistorey building frames for evaluating their natural frequencies and is compared with the predominant frequency of the layered soil system. The results reveal that the varying degree of damage to multistorey buildings in the close proximity of Sabarmati river area was essentially due to the large amplification of the ground and the near resonance condition.

Atomic layer deposition of ZrO2 thin films: Study of growth kinetics and dielectric behaviour

Thin films of ZrO2 have been deposited by ALD on Si(100) and SIMOX using two different metalorganic complexes of Zr as precursors. These films are characterized by X-ray diffraction, transmission and scanning electron microscopies, infrared spectroscopy, and electrical measurements. These show that amorphous ZrO2 films of high dielectric quality may be grown on Si(100) starting about 400degreesC. As the growth temperature is raised, the films become crystalline, the phase formed and the microstructure depending on precursor molecular structure. The phase of ZrO2 formed depends also on the relative duration of the precursor and oxygen pulses. XPS and IR spectroscopy show that films grown at low temperatures contain chemically unbound carbon, its extent depending on the precursor. C-V measurements show that films grown on Si(100) have low interface state density, low leakage current, a hysteresis width of only 10-250 mV and a dielectric constant of similar to16-25.

A comparative study of erbium oxide and gadolinium oxide high-k dielectric thin films grown by low-pressure metalorganic chemical vapour deposition (MOCVD) using beta-Diketonates as precursors

In this paper, a comparative study of thin films of Er2O3 and Gd2O3 grown on n-type Si(100) by low-pressure metalorganic chemical vapour deposition (MOCVD) under the identical conditions has been presented. beta-Diketonate complex of rate earth metals was used as precursor. Description on the evolution of the morphology, structure, optical, and electrical characteristics of films with respect to growth parameters and post-deposition annealing process has been presented. As-gown Gd2O3 films grow with <111> texture, whereas the texture of Er2O3 films strongly depends on the growth temperature (either <100> or <111>). Compositional analysis reveals that the Gd2O3 films grown at or above 500degreesC are carbon free whereas Er2O3 films at upto 525degreesC show the presence of heteroatoms and Er2O3 films grown above 525degreesC are carbon five. The effective dielectric constant is in the range of 7-24, while the fixed charge density is in the range - 10(11) to 10(10) CM-2 as extracted from the C-V characteristics. DC I-V study was carried out to examine the leakage behaviour of films. It reveals that the as-grown Gd2O3 film was very leakey in nature. Annealing of the films in oxidizing ambient for a period of 20 min results in a drastic improvement in the leakage behaviour. The presence of heteroatoms (such as carbon) and their effect on the properties of films are discussed.

Nonlinear cyclic load analysis for lateral response of batter piles in soft clay with a rigorous degradation model

Nonlinear analysis of batter piles in soft clay is performed using the finite element technique. As the batter piles are not only governed by lateral load but also axial load, the effect of P- Delta moment and geometric stiffness matrix is included in the analysis. For implementing the nonlinear soil behavior, reduction in soil strength (degradation), and formation of gap with number of load cycles, a numerical model is developed where a hyperbolic relation is adopted for the soil in static condition and hyperbolic relation considering degradation and gap for cyclic load condition. The numerical model is validated with published experimental results for cyclic lateral loading and the hysteresis loops are developed to predict the load-deflection behavior and soil resistance behavior during consecutive cycles of loading. This paper highlights the importance of a rigorous degradation model for subsequent cycles of loading on the pile-soil system by a hysteretic representation.

Non-linear electrical response of chalcogenide glasses: Memory state phenomena

Investigations on the switching behaviour of arsenic-tellurium glasses with Ge or Al additives, yield interesting information about the dependence of switching on network rigidity, co-ordination of the constituents, glass transition & ambient temperature and glass forming ability.

Treatment of NOx from Diesel Engine Exhaust by Dielectric Barrier Discharge Method

This paper reports improved performance of discharge plasma in filtered engine exhaust treatment. Our paper deals about the removal of NOX emissions from the diesel exhaust by electric discharge plasma. For the treatment of diesel exhaust a new type of reactor referred to as crossflow dielectric barrier discharge reactor has been used, where the gas flow is perpendicular to the corona electrode. Experiments were conducted at different flow rates ranging from 2 l/min to 10 l/min. The discharge plasma assisted barrier discharge reactor has shown promising results in NOX removal at high flow rates.

Nanoindentation response of an ion irradiated Zr-based bulk metallic glass

Nanoindentation experiments were conducted on a Ni+ ion-irradiated Zr-based bulk metallic glass (BMG). The irradiation was carried out using 2.5, 5, 10 and 15 MeV ions and a flux of similar to 10(16) ions/cm(2). Post mortem imaging of the indents reveals a transition in the deformation mechanism of the irradiated regions from heterogeneous shear banding to homogeneous flow. Additionally, the load-displacement curves exhibit a transition from serrated to continuous flow with increasing severity of irradiation damage. The stress-strain response obtained from micro-pillar compression experiments complements the indentation response exhibiting a decrease in the flow stress and an `apparent' strain hardening at the lowest irradiation damage investigated, which is not observed in the as-cast alloy. (C) 2011 Elsevier B.V. All rights reserved.

Treatment of NOx from Diesel Engine Exhaust by Dielectric Barrier Discharge Method

This paper reports improved performance of advantages when compared to its counterpart as it is cost discharge plasma in filtered engine exhaust treatment. Our effective, low capital and operation costs, salable by- paper deals about the removal of NOX emissions from the diesel products, and integration with the existing systems. In this exhaust by electric discharge plasma. For the treatment of diesel paper we describe an alternate reactor geometry referred to exhaust a new type of reactor referred to as cross-flow dielectric as cross-flow DBD reactor, where the exhaust gas flow barrier discharge reactor has been used, where the gas flow is perpendicular to the wire-cylinder reaction chamber. This perpendicular to the corona electrode. Experiments were reactor is used to treat the actual exhaust of a 3.75 kW diesel- conducted at different flow rates ranging from 2 l/min to 10 l/ generator set. The main emphasis is laid on the NOX treatment min. The discharge plasma assisted barrier discharge reactor of diesel engine exhaust. Experiments were carried out at has shown promising results in NOX removal at high flow rates.