Kinetics of oxidation of copper sulfide

The oxidation rate of a cuprous sulfide pellet suspended in a stream of air was followed by measuring the evolution of SO2 titrimetrically. Thin thermocouples embedded in the center of the sample recorded the variation of temperature during oxidation. The reaction was found to be topochemical and the sample temperature was found to be higher than its surroundings initially for about half an hour. After this initial period, the sample temperature decreased to that of the surroundings and remained constant during the rest of the period of over 5 hr. The apparent activation energy from the experimental data was found to be different for the initial (nonisothermal) and subsequent (isothermal) periods. Rate controlling mechanisms for these two intervals have been proposed based on interface chemical reaction, mass transfer resistance, and heat transfer concepts. Fair agreement is found between the theoretical rates based on transport mechanisms and those obtained experimentally

Characteristics of spectral aerosol optical depths over India during ICARB

Spectral aerosol optical depth (AOD) measurements, carried out regularly from a network of observatories spread over the Indian mainland and adjoining islands in the Bay of Bengal and Arabian Sea, are used to examine the spatio-temporal and spectral variations during the period of ICARB (March to May 2006). The AODs and the derived Angstrom parameters showed considerable variations across India during the above period. While at the southern peninsular stations the AODs decreased towards May after a peak in April, in the north Indian regions they increased continuously from March to May. The Angstrom coefficients suggested enhanced coarse mode loading in the north Indian regions, compared to southern India. Nevertheless, as months progressed from March to May, the dominance of coarse mode aerosols increased in the columnar aerosol size spectrum over the entire Indian mainland, maintaining the regional distinctiveness. Compared to the above, the island stations showed considerably low AODs, so too the northeastern station Dibrugarh, indicating the prevalence of cleaner environment. Long-range transport of aerosols from the adjoining regions leads to remarkable changes in the magnitude of the AODs and their wavelength dependencies during March to May. HYSPLIT back-trajectory analysis shows that enhanced long-range transport of aerosols, particularly from the west Asia and northwest coastal India, contributed significantly to the enhancement of AOD and in the flattening of the spectra over entire regions; if it is the peninsular regions and the island Minicoy are more impacted in April, the north Indian regions including the Indo Gangetic Plain get affected the most during May, with the AODs soaring as high as 1.0 at 500 nm. Over the islands, the Angstrom exponent (α) remained significantly lower (~1) over the Arabian Sea compared to Bay of Bengal (BoB) (~1.4) as revealed by the data respectively from Minicoy and Port Blair. Occurrences of higher values of α, showing dominance of accumulation mode aerosols, over BoB are associated well with the advection, above the boundary layer, of fine particles from the east Asian region during March and April. The change in the airmass to marine in May results in a rapid decrease in α over the BoB

Statistics of Impedance, Local Density of States, and Reflection in Quantum Chaotic Systems with Absorption

We are interested in finding the joint distribution function of the real and imaginary parts of the local Green function for a system with chaotic internal wave scattering and a uniform energy loss (absorption). For a microwave cavity attached to a single-mode antenna the same quantity has a meaning of the complex cavity impedance. Using the random matrix approach, we relate its statistics to that of the reflection coefficient and scattering phase and provide exact distributions for systems with beta=2 and beta=4 symmetry class. In the case of beta=1 we provide an interpolation formula which incorporates all known limiting cases and fits excellently available experimental data as well as diverse numeric tests.Comment: 4 pages, 1 figur

Best-bet Options for Integrated Watershed Management: Proceedings of the Comprehensive Assessment of Watershed Programs in India

We sincerely acknowledge the efforts of all the authors who put in together their expertise to write the best-bet options for the different interventions in the integrated watershed management. We also thank the help of several reviewers for giving their constructive suggestions for improving the quality of the chapters. We appreciate the help of Mr KNV Satyanarayana and Sri Lakshmi for word processing and formatting, staff of the Communication Office of ICRISAT for cover design and page-setting, and Shalini N for editorial assistance. We gratefully acknowledge the financial assistance provided by the Department of Land Resources under Ministry of Rural Development and Ministry of Agriculture to undertake the Comprehensive Assessment of the Watershed Programs in India

Constructive control of quantum systems using factorization of unitary operators

We demonstrate how structured decompositions of unitary operators can be employed to derive control schemes for finite-level quantum systems that require only sequences of simple control pulses such as square wave pulses with finite rise and decay times or Gaussian wavepackets. To illustrate the technique it is applied to find control schemes to achieve population transfers for pure-state systems, complete inversions of the ensemble populations for mixed-state systems, create arbitrary superposition states and optimize the ensemble average of dynamic observables.Comment: 28 pages, IoP LaTeX, principal author has moved to Cambridge University ([email protected]

Optimal Control of One-Qubit Gates

We consider the problem of carrying an initial Bloch vector to a final Bloch vector in a specified amount of time under the action of three control fields (a vector control field). We show that this control problem is solvable and therefore it is possible to optimize the control. We choose the physically motivated criteria of minimum energy spent in the control, minimum magnitude of the rate of change of the control and a combination of both. We find exact analytical solutions.Comment: 5 page

Resistance in groundnut to Sclerotium rolfsii‐caused stem and pod rot†

A total of 859 groundnut germplasm accessions and breeding lines was screened in field trials for resistance to stem and pod rot caused by S. [Corticium] rolfsii during the 1985-88 post-rainy seasons at the ICRISAT Asia Center, Patancheru, India. Lines that showed low susceptibility to stem and pod rot (<10%) were further evaluated at the Marathwada Agricultural University farm, Parbhani, India, during 1987-91 in the rainy and summer seasons. Of the 20 selected genotypes, 7 interspecific hybrid derivatives (326, 988, 1019, 1024, 1065, 1267 and 1364) consistently exhibited stable resistance to both stem and pod rot. Nine breeding lines (ICGV 86034, 86124, 86252, 86388, 86590, 86606, 86635, 87160 and 87359) showed low susceptibility to stem and/or pod rot. Effective screening for stem and pod rot resistance was possible in the post-rainy and summer seasons. Several lines with low susceptibility to C. rolfsii also possess resistance to rust (Puccinia arachidis) and moderate resistance/tolerance to late leaf spot (Phaeoisariopsis personata [Mycosphaerella berkeleyi]). Useful features of these lines are discusse

Fatigue behaviour of FDM-3D printed polymers, polymeric composites and architected cellular materials

Polymer-based materials are increasingly produced through fused deposition modelling (FDM) – an additive manufacturing process, due to its intrinsic advantages in manufacturing complex shapes and structures at low overhead costs. The versatility of this technology has attracted several industries to print complex geometrical structures. This underlines the importance of studying the mechanical strength of FDM printed polymeric materials, especially their fatigue behaviour in cyclic loading conditions. Conventionally manufactured polymeric materials (e.g. injection moulding) have superior fatigue performance than FDM printed materials. Unlike conventionally manufactured polymers, FDM-made polymers have layer by layer adhesion and the influence of printing parameters make fatigue analysis complex and critical. The influences of printing parameters and printing material characteristics have a significant impact on the fatigue behaviour of these materials. The underlying mechanism behind the fatigue of FDM printed polymers is crucial for the assessment of these materials in structural applications. However, the fatigue behaviour of FDM printed polymeric materials has not been reviewed in detail. Therefore, this article aims to evaluate 3D printed polymeric materials’ fatigue properties. The importance of fatigue in the FDM printed biomedical materials is also reviewed, and more importantly, the novel FDM printed architected cellular material fatigue properties are also introduced. © 2020 The Author(s

Super-reflection of light from a random amplifying medium with disorder in the complex refractive index : Statistics of fluctuations

The probability distribution of the reflection coefficient for light reflected from a one-dimensional random amplifying medium with {\it cross-correlated} spatial disorder in the real and the imaginary parts of the refractive index is derived using the method of invariant imbedding. The statistics of fluctuations have been obtained for both the correlated telegraph noise and the Gaussian white-noise models for the disorder. In both cases, an enhanced backscattering (super-reflection with reflection coefficient greater than unity) results because of coherent feedback due to Anderson localization and coherent amplification in the medium. The results show that the effect of randomness in the imaginary part of the refractive index on localization and super-reflection is qualitatively different.Comment: RevTex 6 pages, 3 figures in ps file

On Quantum State Observability and Measurement

We consider the problem of determining the state of a quantum system given one or more readings of the expectation value of an observable. The system is assumed to be a finite dimensional quantum control system for which we can influence the dynamics by generating all the unitary evolutions in a Lie group. We investigate to what extent, by an appropriate sequence of evolutions and measurements, we can obtain information on the initial state of the system. We present a system theoretic viewpoint of this problem in that we study the {\it observability} of the system. In this context, we characterize the equivalence classes of indistinguishable states and propose algorithms for state identification