Management and Performance of APPLE Battery in High Temperature Environment

India's first experimental communication satellite, APPLE, carried a 12 AH Ni-Cd battery for supplying power during eclipse. Failure to deploy one of the two solar panels resulted in the battery operating in a high temperature environment, around 40 C. This also resulted in the battery being used in diurnal cycles rather than just half yearly eclipse seasons. The management and performance of the battery during its life of two years are described. An attempt to identify the probable degradation mechanisms is also made

Entanglement dynamics and quantum state transport in spin chains

We study the dynamics of a Heisenberg-XY spin chain with an unknown state coded into one qubit or a pair of entangled qubits, with the rest of the spins being in a polarized state. The time evolution involves magnon excitations, and through them the entanglement is transported across the channel. For a large number of qubits, explicit formulae for the concurrences, measures for two-qubit entanglements, and the fidelity for recovering the state some distance away are calculated as functions of time. Initial states with an entangled pair of qubits show better fidelity, which takes its first maximum value at earlier times, compared to initial states with no entangled pair. In particular initial states with a pair of qubits in an unknown state (alpha up-up + beta down-down) are best suited for quantum state transport.Comment: 4 pages, 3 figure

Size-dependent magnetization fluctuations in NiO nanoparticles

The finite size and surface roughness effects on the magnetization of NiO nanoparticles is investigated. A large magnetic moment arises for an antiferromagnetic nanoparticle due to these effects. The magnetic moment without the surface roughness has a non-monotonic and oscillatory dependence on $R$, the size of the particles, with the amplitude of the fluctuations varying linearly with $R$. The geometry of the particle also matters a lot in the calculation of the net magnetic moment. An oblate spheroid shape particle shows an increase in net magnetic moment by increasing oblateness of the particle. However, the magnetic moment values thus calculated are very small compared to the experimental values for various sizes, indicating that the bulk antiferromagnetic structure may not hold near the surface. We incorporate the surface roughness in two different ways; an ordered surface with surface spins inside a surface roughness shell aligned due to an internal field, and a disordered surface with randomly oriented spins inside surface roughness shell. Taking a variational approach we find that the core interaction strength is modified for nontrivial values of $\Delta$ which is a signature of multi-sublattice ordering for nanoparticles. The surface roughness scale $\Delta$ is also showing size dependent fluctuations, with an envelope decay $\Delta\sim R^{-1/5}$. The net magnetic moment values calculated using spheroidal shape and ordered surface are close to the experimental values for different sizes.Comment: 19 pages, 8 figures, Accepted for publication in Int. J. Mod. Phys.

Retail Web System Upgrading with Strategic Customer Using Threshold Policy

This paper mainly deals with the problems that online retailers are facing by some group of strategic customers by upgrading web system and goods pricing. A monopolist price of a product for which stylized dynamic pricing model is considered at the beginning and the price change is done on the product after considering some set of constraints based on the product availability. Due to some network issues sometimes website may get problems at that time there may be a chance of transaction failure for customer during online purchasing. To predict this probability and doing purchasing opinion depending on the belief of Transaction Success Probability (TSP).Considering this there will be a threshold policy for purchasing by customers here it is going to consider it as first one: Customers buy products only if his valuation for products is above threshold (total reduced profit) otherwise they will not take it into consideration. The threshold rises as TSP degrades, or customers turn out to be risk averse. Here we obtain the best cost of each phase and make out the best strategy for online shopping site customizing by threshold and upgrade the system when present TSP is less than threshold. The online trader turns to increase the price if he disregards strategic customer behavior. The value of disregarding strategic customer deeds is significant. The profit loss cost of disregarding strategic customer deeds grows as customer transaction cost rises

Nature & Role of Metal-Oxygen Bond in the Activity of a Zn-Cr-Fe Oxide Catalyst

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Formation of quasi-free and bubble positronium states in water and aqueous solutions

It is shown that in aqueous solutions a positronium atom is first formed in the quasi-free state, and, after 50-100 ps, becomes localized in a nanobubble. Analysis of the annihilation spectra of NaNO3 aqueous solutions shows that the hydrated electron is not involved in the positronium (Ps) formation

Quality Analysis of Software Applications using Software Reliability Growth Models and Deep Learning Models

Finding the faults in the software is a very tedious task. Many software companies are trying to develop high-quality software which is having no faults. It is very important to analyze the errors, faults, and bugs in software development. Software reliability growth models (SRGM's) are used to help the software industries to create quality software products. Quality is the software metric that is used to analyze the performance of the software product. The software product which is having no errors or faults is considered the best software product. SRGM is also utilized to analyze the software quality based on the programming language. Deep Learning (DL) is a sub-domain in machine learning to solve several complex issues in software development. Finding accurate patterns from software faults is a very tedious task. DL algorithm performs better in integrating the SRGM with the DL approaches giving better results based on software fault detection. Many software faults real-time datasets are available to analyze the DL approaches. The performances of the various integrated models are analyzed by showing the quality metrics

Behaviour of Oxide Catalysts During the Catalysed Reactions of Propan-2-ol

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Ultrastructure of the epithelial cells and oleo-gumresin secretion in Boswellia serrata (Burseraceae)

The ultrastructure of epithelial cells of oleo-gumresin ducts in Boswellia serrata, the source of Indian olibanum, is described. Oleo-gumresin ducts are present in primary and secondary phloem. The duct lumen forms an enlarged apoplastic space surrounded by epithelial cells. The epithelial cells are rich in dictyosomes, lipid bodies, mitochondria with dilated cristae, multivesicular bodies, osmiophilic materials, plastids and vesicIes. Plastids have poorly developed internal membranes. Dictyosomes and plastids are possible sites of resin synthesis. The gum component of the exudate is formed in dictyosomes and from the outer layers of the inner tangential wall (wall facing the duct lumen). This wall is replenished from inside by the activity of dictyosomes. The secretory materials are transported to the apoplast by granulocrine and eccrine secretion. They migrate through the loose microfibrils of the inner tangential wall into the duct lumen. Rarely, epithelial cells of young ducts have rudimentary plasmodesmata on the inner tangential wall which may be channels for passage of secretory materials into the duct lumen

Spin Decoherence from Hamiltonian dynamics in Quantum Dots

The dynamics of a spin-1/2 particle coupled to a nuclear spin bath through an isotropic Heisenberg interaction is studied, as a model for the spin decoherence in quantum dots. The time-dependent polarization of the central spin is calculated as a function of the bath-spin distribution and the polarizations of the initial bath state. For short times, the polarization of the central spin shows a gaussian decay, and at later times it revives displaying nonmonotonic time dependence. The decoherence time scale dep ends on moments of the bath-spin distribuition, and also on the polarization strengths in various bath-spin channels. The bath polarizations have a tendency to increase the decoherence time scale. The effective dynamics of the central spin polarization is shown to be describ ed by a master equation with non-markovian features.Comment: 11 pages, 6 figures Accepted for publication in Phys.Rev