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Key soil parameters, organic matter, soil pH and plant nutrients determine the capacity of a soil to sustain plant and animal productivity. Conservation agriculture (CA) and crop diversification or intensification may change these soil parameters positively or negatively, which eventually affect long-term sustainability. We monitored these key soil properties (at depths of 0-15 and 15-30 cm) under CA-based sustainable intensification practices: zero-till (ZT), and crop residue retention, and crop rotations on Inceptisols and Entisols in the Eastern Ganga Alluvial Plains from 2014 to 2017. The rainfall of this sub-tropical region is 1273-3201 mm. Soil organic carbon (C) ranged within 0.46-1.13% and generally followed (positive) rainfall gradients. At all sites, the soil under ZT tended to have higher organic C than conventional tillage (CT). Soil pHH2o ranged within 5.7-7.8 across the region. At all sites, soil pH generally decreased under ZT compared to CT. This was most marked at some acidic soil sites where pH decreased by up to 0.4 units; the lower the initial soil pH, the higher was the decrease in pH under ZT practice. In contrast, the reverse trend was observed for soil organic C. Partial nutrient balances for N, P and K in rice-wheat and rice-maize systems were positive for N and P ( Additional keywords: cropping systems, maize, partial nutrient balance, rice, soil organic C, soil pH, South Asia, wheat. Received 14 June 2019, accepted 30 July 2019, published online 10 September 2019, Introduction Conservation agriculture (CA) and crop diversification or intensification are the major components of the emerging farming systems for ensuring food security in South Asia (Jat et al. 2014; Islam [...]

Nearly a century ago it was recognized (1) that radiation absorption by stellar matter controls the internal temperature profiles within stars. Laboratory opacity measurements, however, have never been performed at stellar interior conditions, introducing uncertainties in stellar models (2-5). A particular problem arose (2,3,6,8) when refined photosphere spectral analysis (9,10) led to reductions of 30-50 per cent in the inferred amounts of carbon, nitrogen and oxygen in the Sun. Standard solar models (11) using the revised element abundances disagree with helioseismic observations that determine the internal solar structure using acoustic oscillations. This could be resolved if the true mean opacity for the solar interior matter were roughly 15 per cent higher than predicted (2,3,6-8), because increased opacity compensates for the decreased element abundances. Iron accounts for a quarter of the total opacity (2,12) at the solar radiation/convection zone boundary. Here we report measurements of wavelength-resolved iron opacity at electron temperatures of 1.9-2.3 million kelvin and electron densities of (0.7-4.0) X [10.sup.22] per cubic centimetre, conditions very similar to those in the solar region that affects the discrepancy the most: the radiation/convection zone boundary. The measured wavelength-dependent opacity is 30-400 per cent higher than predicted. This represents roughly half the change in the mean opacity needed to resolve the solar discrepancy' even though iron is only one of many elements that contribute to opacity., In the region of the solar radiation/convection zone boundary (11), the electron temperature [T.sub.e] ≅ 2.1 X [10.sup.6] K, the electron density [n.sub.e] ≅ 9 X [10.sup.22] [cm.sup.-3], and the [...]

In this paper, a cumulative-sum-based fault detection algorithm is proposed for the power system relaying application. Literature suggests the successful application of this method to process control systems where the deviation of parameters is tracked to indicate any abnormal conditions. The effectiveness of the algorithm is found to be better than the traditional methods in the presence of noise, system frequency deviation, and other uncertainties. It is also not affected by load change in a system. Above all, it provides relatively higher index values without compromising detection speed. Index Terms--Change detection, digital relay, fault detection, line protection, protective relaying, transmission system.

When a remotely sited wind farm is connected to the utility power system through a distribution line, the overcurrent relay at the common coupling point needs a directional feature. This paper presents a method for estimating the direction of fault in such radial distribution systems using phase change in current. The difference in phase angle between the positive-sequence component of the current during fault and prefault conditions has been found to be a good indicator of the fault direction in a three-phase system. A rule base formed for the purpose decides the location of fault with respect to the relay in a distribution system. Such a strategy reduces the cost of the voltage sensor and/or connection for a protection scheme which is of relevance in emerging distributed-generation systems. The algorithm has been tested through simulation for different radial distribution systems. Index Terms--Digital relay, directional relay, distributed generation, feeder protection, overcurrent relay, phasor estimation.

Wind speed varies continuously throughout a day resulting in fluctuating wind farm output power. When such a farm is connected to the grid through a line, the transmitted power and the relay end voltage (with respect to grid voltage) fluctuate continuously. In this paper, the protection of such a line with distance relay is investigated. The ideal trip characteristic for distance relay is studied with change in conditions of the wind farm. A method is proposed to set the boundary adaptively using local information only. Index Terms--Adaptive protection, digital protection, distance relaying, transmission line protection, wind farm operation and integration.

Frequency is an important parameter in power system monitoring, control, and protection. A least mean square (LMS) algorithm in complex form is presented in this paper to estimate power system frequency where the formulated structure is very simple. The three-phase voltages are converted to a complex form for processing by the proposed algorithm. To enhance the convergence characteristic of the complex form of the LMS algorithm, a variable adaptation step-size is incorporated. The performance of the new algorithm is studied through simulations at different situations of the power system. Index Terms--Complex least mean square (LMS), frequency estimation, least mean square algorithm, power system monitoring.

The fabrication of highly epitaxial films on sapphire and Si single crystalline and quartz substrates under different growth and optimization conditions is reported using pulsed-laser deposition technique. The results show superior spectroscopic performance on the films grown on sapphire substrates due to high quality and epitaxial nature of the film.

Series capacitor protected by metal-oxide varistor and air-gap arrangement imposes problems to line protection and other online decisions. Discrete wavelet transform integrated with a fuzzy logic system is designed for fault classification of a transmission line possessing a series capacitor at the midpoint. The approach uses information obtained from the wavelet decomposition of current signals for faulty phase selection and section identification. Two different FLSs are designed for the two classification objectives in this paper. Index Terms--Fault classification, fuzzy logic system, series compensation, transmission line protection, wavelet transform.

The slantlet transform (SLT) is an orthogonal discrete wavelet transform (DWT) with two zero moments and with improved time localization. It also retains the basic characteristic of the usual filterbank such as octave band characteristic, a scale dilation factor of two and efficient implementation. However, the SLT is based on the principle of designing different filters for different scales unlike iterated filterbank approaches for the DWT. In this paper a novel approach for power quality data compression using the SLT is presented and its performance in terms of compression ratio (CR), percentage of energy retained and mean square error present in the reconstructed signals is assessed. Varieties of power quality events, which include voltage sag, swell, momentary interruption, harmonics, transient oscillation and voltage flicker are used to test the performance of the new approach. Computer simulation results indicate that the SLT offers superior compression performance compared to the conventional discrete cosine transform (DCT) and the DWT based approaches. Index Terms--Discrete wavelet transform (DWT), power quality waveform analysis, slantlet transform.

Multifilamentary tapes of (Bi-Pb)2Sr2Ca2Cu3Ox/Ag were studied to determine flux pinning and dissipation.

The flux pinning and optimization of melt-processed ternary (Nd-Eu-Gd)Ba2Cu2O7-x bulk materials is reported.

A superconducting quantum interference device was used to investigate the magnetization of NdBa2Cu3Oy single crystals with varying oxygen contents.

Flux pinning behavior of (Nd-Eu-Gd)Ba2Cu3Oy superconductors was examined.

The paper proposes an extended complex Kalman filter and employs it for the estimation of power system frequency in the presence of random noise and distortions. From the discrete values of the 3-phase voltage signals of a power system, a complex voltage vector is formed using the well known [Alpha][Beta]-transform. A nonlinear state space formulation is then obtained for this complex signal and an extended Kalman filtering approach is used to compute the true state of the model iteratively with significant noise and harmonic distortions. As the frequency is modeled as a state, the estimation of the state vector yields the unknown power system frequency. Several computer simulations test results are presented in the paper to highlight the usefulness of this approach in estimating near nominal and off-nominal power system frequencies. Keywords-Power system frequency, Frequency estimation, Extended Kalman filter, Nonlinear filter