Automatic Generation Control for Interconnected Hydro-thermal System with the help of Conventional Controllers

The Problem of Automatic Generation Control of large interconnected multi-area system is necessitated by the importance of maintenance of frequency and tie-line flows at their scheduled values. Disturbance in any part of the power system network has its effect on the frequency and tie-line power flows of the entire network. Thus, It is the responsibility of the Power system engineers to ensure that adequate power is delivered to the load reliably and economically so that nominal condition will be re-established. This Research paper aims to represents how nominal value can be achieved by close loop control of real and reactive powers generated in the controllable source of the system with the help of conventional controllers.DOI:http://dx.doi.org/10.11591/ijece.v2i4.30

Flow of forces and couples to the cylindrical solids through system asymmetry thin-walled elements of varying stiffness

Задача про передачу силового і моментного навантаження до криволінійного отвору нескінченної ізотропної пластинки через систему несиметричних відносно серединної площини тонкостінних елементів змінної жорсткості зведена до системи чотирьох сингулярних інтегрально– диференціальних рівнянь з ядрами Гільберта. Методом колокації досліджується вплив на напружений стан пластинки несиметричності підсилень, способу їх розміщення на контурі отвору.The problem of flow of forces and couples to the curvilinear hole in a infinite isotropic plate through system of asymmetrical by a middle plane the thin-walled elements of varying stiffness reduce to the system of four singular integral-differential equations with cores of Hilbert. The effect of asymmetry strengthens and location mode by method of collocation does investigate

Local Time Asymmetries in Jupiter's Magnetodisc Currents

We present an investigation into the currents within the Jovian magnetodisc using all available spacecraft magnetometer data up until 28th July, 2018. Using automated data analysis processes as well as the most recent intrinsic field and current disk geometry models, a full local time coverage of the magnetodisc currents using 7382 lobe traversals over 39 years is constructed. Our study demonstrates clear local time asymmetries in both the radial and azimuthal height integrated current densities throughout the current disk. Asymmetries persist within 30 R$_\mathrm{J}$ where most models assume axisymmetry. Inward radial currents are found in the previously unmapped dusk and noon sectors. Azimuthal currents are found to be weaker in the dayside magnetosphere than the nightside, in agreement with global magnetohydrodynamic simulations. The divergence of the azimuthal and radial currents indicates that downward field aligned currents exist within the outer dayside magnetosphere. The presence of azimuthal currents is shown to highly influence the location of the field aligned currents which emphasizes the importance of the azimuthal currents in future Magnetosphere-Ionosphere coupling models. Integrating the divergence of the height integrated current densities we find that 1.87 MA R$_\mathrm{J}^{-2}$ of return current density required for system closure is absent

Ionospheric flow shear associated with the preexisting auroral arc: A statistical study from the FAST spacecraft data

An auroral substorm is a disturbance in the magnetosphere that releases energy stored in the magnetotail into the high‐latitude ionosphere. By definition, an auroral substorm commences when a discrete auroral arc brightens and subsequently expands poleward and azimuthally. The arc that brightens is usually the most equatorward of several auroral arcs that remain quiescent for ~5 to ~60 min before the breakup commences. This arc is often referred to as the “preexisting auroral arc (PAA)” or the “growth‐phase arc.” In this study, we use FAST measurements to establish the statistics of flow patterns near PAAs in the ionosphere. We find that flow shear is present in the vicinity of a preexisting arc. When a PAA appears in the evening sector, enhanced westward flow develops equatorward of the arc, whereas when a PAA appears in the morning sector, enhanced eastward flow develops poleward of the arc. We benchmark locations of the PAAs relative to large‐scale field‐aligned currents (FACs) and convective flows in the ionosphere, finding that the arc forms in the upward current region within ~1° of the Region 1/Region 2 boundary in all local time sectors from 20 MLT to 03 MLT. We also find that near midnight in the Harang region, most of the PAAs lie within 0.5° poleward of the low‐latitude Region 1/Region 2 currents boundary and sit between the westward and eastward flow peak but equatorward of the flow reversal point. Finally, we examine arc‐associated electrodynamics and find that the FAC of the PAA is mainly closed by the north‐south Pedersen current in the ionosphere.Key PointsAn ionospheric flow shear is associated with the preexisting auroral arcThe FAC of the PAA is primarily closed by N‐S Pedersen current in the ionosphereThe PAA is located very close to the R1/R2 boundaryPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112278/1/jgra51768.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112278/2/jgra51768-sup-0001-supinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112278/3/jgra51768-sup-0002-supinfo.pd

Comparative genomic analysis reveals habitat-specific genes and regulatory hubs within the genus Novosphingobium

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in mSystems 2 (2017): e00020-17, doi:10.1128/mSystems.00020-17.Species belonging to the genus Novosphingobium are found in many different habitats and have been identified as metabolically versatile. Through comparative genomic analysis, we identified habitat-specific genes and regulatory hubs that could determine habitat selection for Novosphingobium spp. Genomes from 27 Novosphingobium strains isolated from diverse habitats such as rhizosphere soil, plant surfaces, heavily contaminated soils, and marine and freshwater environments were analyzed. Genome size and coding potential were widely variable, differing significantly between habitats. Phylogenetic relationships between strains were less likely to describe functional genotype similarity than the habitat from which they were isolated. In this study, strains (19 out of 27) with a recorded habitat of isolation, and at least 3 representative strains per habitat, comprised four ecological groups—rhizosphere, contaminated soil, marine, and freshwater. Sulfur acquisition and metabolism were the only core genomic traits to differ significantly in proportion between these ecological groups; for example, alkane sulfonate (ssuABCD) assimilation was found exclusively in all of the rhizospheric isolates. When we examined osmolytic regulation in Novosphingobium spp. through ectoine biosynthesis, which was assumed to be marine habitat specific, we found that it was also present in isolates from contaminated soil, suggesting its relevance beyond the marine system. Novosphingobium strains were also found to harbor a wide variety of mono- and dioxygenases, responsible for the metabolism of several aromatic compounds, suggesting their potential to act as degraders of a variety of xenobiotic compounds. Protein-protein interaction analysis revealed β-barrel outer membrane proteins as habitat-specific hubs in each of the four habitats—freshwater (Saro_1868), marine water (PP1Y_AT17644), rhizosphere (PMI02_00367), and soil (V474_17210). These outer membrane proteins could play a key role in habitat demarcation and extend our understanding of the metabolic versatility of the Novosphingobium species.This work was supported by grants from the Department of Biotechnology (DBT), R.K., S.H., K.P., A.B., and U.S. gratefully acknowledge the National Bureau of Agriculturally Important Microorganisms (NBAIM), Science and Engineering Research Board (SERB), N-PDF (PDF/2015/000062), (PDF/2015, 000319), University Grant Commission (UGC) for the Dr. D. S. Kothari Postdoctoral Fellowship and UGC for providing fellowships, respectively

Dynamics of Ganymede's magnetopause: Intermittent reconnection under steady external conditions

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95138/1/jgra20818.pd

In situ observations of the “preexisting auroral arc” by THEMIS all sky imagers and the FAST spacecraft

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95671/1/jgra21670.pd

LAPLACE: A mission to Europa and the Jupiter System for ESA's Cosmic Vision Programme

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Tidal Heating: Lessons from Io and the Jovian System - Final Report

Tidal heating is key to the evolution and habitability of many worlds across our solar system and beyond. However, there remain fundamental gaps in our understanding of tidal heating and coupled orbital evolution, which motivated a Keck Institute for Space Studies (KISS) workshop on this topic. The Cassini mission has led to many recent results about ocean worlds and what may become a new paradigm for understanding orbital evolution with tidal heating, the model of resonance locking in the parent planet (Fuller et al., 2016). Resonance locking explains how subsurface oceans may persist over much of geologic time, even in tiny Enceladus. The discovery of the Laplace resonance of Io, Europa, and Ganymede orbiting Jupiter led to the prediction of intense tidal heating of Io (Peale et al., 1979); this system provides the greatest potential for advances in the next few decades. Europa Clipper and JUpiter ICy moons Explorer (JUICE) will provide in-depth studies of Europa and Ganymede in the 2030s. The easily observed heat flow of Io, from hundreds of continually erupting volcanoes, makes it an ideal target for further investigation, and the missing link—along with missions in development—to understand the Laplace system. We identified five key questions to drive future research and exploration: (Q1) What do volcanic eruptions tell us about the interiors of tidally heated bodies (e.g., Io, Enceladus, and perhaps Europa and Triton)? (Q2) How is tidal dissipation partitioned between solid and liquid materials? (Q3) Does Io have a melt-rich layer, or “magma ocean”, that mechanically decouples the lithosphere from the deeper interior? (Q4) Is the Jupiter/Laplace system in equilibrium (i.e., does the satellite’s heat output equal the rate at which energy is generated)? (Q5) Can stable isotope measurements inform long-term evolution of tidally heated bodies? The most promising avenues to address these questions include a new spacecraft mission making close flybys of Io, missions orbiting and landing on key worlds such as Europa and Enceladus, technology developments to enable advanced techniques, closer coupling between laboratory experiments and tidal heating theory, and advances in Earth-based telescopic observations of solar system and extrasolar planets and moons. All of these avenues would benefit from technological developments. An Io mission should: characterize volcanic processes (Q1); test interior models via a set of geophysical measurements coupled with laboratory experiments and theory (Q2 and Q3); measure the rate of Io’s orbital migration (to complement similar measurements expected at Europa and Ganymede) to determine if the Laplace resonance is in equilibrium (Q4); and determine neutral compositions and measure stable isotopes in Io’s atmosphere and plumes (Q5). No new technologies are required for such an Io mission following advances in radiation design and solar power realized for Europa Clipper and JUICE. Seismology is a promising avenue for future exploration, either from landers or remote laser reflectometry, and interferometric synthetic aperture radar (InSAR) could be revolutionary on these active worlds, but advanced power systems plus lower mass and power-active instruments are needed for operation in the outer solar system

Recommendations for Addressing Priority Io Science in the Next Decade

Io is a priority destination for solar system exploration. The scope and importance of science questions at Io necessitates a broad portfolio of research and analysis, telescopic observations, and planetary missions - including a dedicated New Frontiers class Io mission