Planex Inc.

Ahmadābād, India

Planex Inc.

Ahmadābād, India
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Sinha R.K.,Planex Inc. | Vijayan S.,Planex Inc. | Bharti R.R.,Planex Inc.
Icarus | Year: 2017

Lobate debris aprons (LDA) and lineated valley fill (LVF) have been broadly recognized in the mid-latitudes of Mars and their subsequent analyses using data from the SHAllow RADar (SHARAD) instrument has suggested evidence for contemporary ice preserved beneath these features. In this study, we conduct detailed characterization of newly identified LDA flow units within the Tanaica Montes region (39.55˚ N, 269.17˚ E) of Mars to assess and understand the similarities in their emplacement with respect to LDA flow units mapped in other regions of Mars. We utilize the Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) images and SHAllow RADar (SHARAD) datasets for geomorphic and subsurface analysis and Mars Global Surveyor (MGS) Mars Orbiter Laser Altimeter (MOLA) point tracks for topographic analysis. Geomorphic observation of LDA flow units surrounding the montes flanks and massif walls reveal integrated pattern of convergence and divergence and evidence of bending and deflection within the flow lines that resulted in concentric, loop-like flow patterns in the downslope. Brain-terrain texture and craters with varying morphological characteristics (ring-mold type) is suggestive that LDAs may be similar to ice-rich, debris-covered glaciers. MOLA point track based convex-up topographic profiles of LDAs suggest that their thickness vary in the range of ∼100–200 m in both the northwestern and southeastern portions of study region. Further, the slope values of mapped LDA surfaces within the study region are within ∼0.1˚–4˚. The extent of mapped LDAs within the study region is such that some of the low elevation (∼0.8–1.3 km) portions of montes flanks are surrounded by relatively less extent (up to ∼0.5–0.8 km) of LDA flow units. Geomorphic and topographic evidence for flow units that appear to be superposed on the main LDA body collectively suggest the possibility of episodic glacial activity in the region. Furthermore, based on the alignment of subsurface reflectors with the surrounding plains when a permittivity of ice (3.2) is assumed and the radargram is depth-corrected, we infer that some of the portions of LDA flow units have preserved ice in their subsurface up to ∼300–500 m depth. Crater size frequency distribution of craters counted on LDA surface indicates that the best-fit age is ∼110 Ma. In addition, the LDA surfaces exhibit different best-fit ages for different types of crater morphologies (bowl-shaped, ring-mold and infilled craters) included in the crater count statistics. Together, these observations and the interpretations suggest that most, if not all, of the LDAs in the study region are like classical LDAs mapped in other regions of Mars (e.g. along the mid-latitude dichotomy boundary and eastern Hellas region). These results indicate that a widespread accumulation and preservation of ice has occurred during the Late Amazonian as suggested in previous studies. © 2017 Elsevier Inc.

Acharyya K.,University of Virginia | Acharyya K.,Planex Inc. | Herbst E.,University of Virginia
Astrophysical Journal | Year: 2016

The Large (LMC) and Small (SMC) Magellanic Clouds are irregular satellite galaxies of the Milky Way. Both are metal- and dust-poor, although the SMC is significantly poorer in both. We have recently simulated the chemistry in cold dense regions of the LMC and found that a rich chemistry exists in the gas-phase. In this paper, we report a companion study of the chemistry of dense regions of the SMC, confining our attention to cold regions of dense clouds with a variety of densities, visual extinctions, and grain temperatures, and a fixed gas-phase temperature. With a gas-to-dust ratio and elemental abundances based on observations and scaling, we found that for molecules like CO and N2, which are predominantly formed in the gas phase, their abundances are consistent with the reduced elemental abundances of their constituent elements above 25 K; however, for species that are produced fully (e.g., CH3OH) or partially on the grain surface (e.g., H2CO, NH3), the dependence on metallicity can be complex. Most of the major gas-phase species observed in our Galaxy are produced in the SMC although in lower quantities. With our simulations, we are able to explain observed gas-phase abundances reasonably well in the dense sources N27 and LIRS 36. We have also compared our calculated abundances of selected ices with limited observations in dense regions in front of young stellar objects. © 2016. The American Astronomical Society. All rights reserved.

Kusuma K.N.,Planex Inc. | Sebastian N.,Planex Inc. | Murty S.V.S.,Planex Inc.
Planetary and Space Science | Year: 2012

Spectral information from the Moon Mineralogy Mapper (M3) onboard Chandrayaan-1 and DIVINER Lunar Radiometer onboard LRO have been used for geochemical and mineralogical characterisation of the Gruithuisen region on Moon along with morphometrical information from LOLA Digital elevation model. The apparent reflectance of M3 on global mode is used for (1) spectral characterisation (2) estimating the abundance of Ti and Fe using Luceys method and (3) discriminating non-mare region from mare regions by means of Minimum Noise Fraction (MNF) transform and Integrated Band Depth (IBD) parameters. Christensen frequency (CF) value derived from DIVINER data is used to delineate the silica saturated lithology from the undersaturated rocks as well as to delineate their spatial spread. Low values of FeO, TiO 2, and IBD indicate non-mare nature of the domes and highland material, also supplemented by CF values. The highland rocks represent signatures of sodic plagioclase, the end result of plagioclase crystallisation from Lunar Magma Ocean. Compositional variations are observed among the domes. NW dome has highest silica concentration than the other two domes and in turn higher viscosity. It is most likely that the three domes tapped residual liquid from different locations of the residual magma chamber which is in constant mixing. The extrusion is probably a localised phenomenon, where urKREEP welled out along the zone of crustal weakness formed by Imbrium Impact. It is likely that δ dome has extruded over a larger time span than other two features. © 2012 Elsevier Ltd. All rights reserved.

Morphologic characteristics of ice-rich landforms in the martian mid-latitudes record evidence for significant modification of the landscape in response to spin-axis/orbital parameter-driven shifts in the Late Amazonian climate. These landforms are spatially distributed across the mid-latitudes and their co-existing presence has so far not been observed from a single crater to infer how exactly a terrain has been modified while Mars was undergoing major-moderate-minor shifts in its Late Amazonian climate. We have therefore carried out an in-depth investigation of Moreux crater (~135. km, centered at 41.66°N, 44.44°E in the Protonilus Mensae region) for identification of features associated with recent and episodic glacial events and for emphasizing the role played by these glacial events in the modification of the crater. Evidence for extensive modification of the surfaces over crater rim/wall and around central peak by emplacement of multiple scales of ice-rich landforms that represents large history of glacial activities was found. From our results we document phases of major-moderate-minor glacial activities within the crater as: (1) piedmont lobes/lobate debris aprons/linear valley fills (~1. Ga-100. Ma), (2) viscous flow features (~30-0.1. Ma) and (3) gullies/thermal contraction crack polygons (~2.1-0.4. Ma). The form and distribution of the random valleys observed within Moreux suggests their formation by pressure-induced melting and flow occurring beneath an extensive layer of ice. We also suggest that central peak of Moreux probably acted as the locus for accumulation of ice/snow and the diversity of glacial/periglacial features within the crater was possibly controlled by differences in the amount of accumulated ice/snow and the rate at which the terrain responded to the shifts in climate during subsequent periods of obliquity changes. Taken together, these ice-rich deposits within Moreux suggest that sequential modification of the crater surfaces over the rim/wall and around central peak has occurred over the last tens of millions of years of martian history. This new evidence thus adds another well-documented case to rapidly accumulating evidences for widespread glacial activity in the middle latitudes of Mars in recent martian history. © 2014 Elsevier Inc.

Sinha R.K.,Planex Inc. | Murty S.V.S.,Planex Inc.
Planetary and Space Science | Year: 2013

In this study, we examine the existence of multiple episodes of glacial activities in Deuteronilus Mensae region on Mars from the analysis of high-resolution remote sensing images acquired by Mars Reconnaissance Orbiter (MRO) ConText Camera (CTX) and High resolution imaging science experiment (HiRISE). The investigated portion from northern mid-latitude of Mars is centered at 44.6 N and 28.8 E and lies ~200 km to south of the largest crater (Lyot) of northern plains. We have critically examined the features on the surface of regional aprons and suggested a possible process by which these formations would have resulted. The entire morphology of the surface was mapped using CTX data sets for developing a general idea about the class of landforms and their extent. The topographic characteristics of the region were derived from Mars Orbiter Laser Altimeter (MOLA) data sets to assess the down-slope flow of ice-debris mixture and the local slope-variations were determined to interpret the flow of small-scale features. The degradational extent of craters lying on the surface of linear valley fill (LVF) flow and the formation of layered pit units in the low-lying region of plateau 2 were systematically explained to account for the presence of ice in the near surface beneath the debris apron. The examined flow-features on the apron surface were compared with their terrestrial glacial analogues for deducing the possible explanation for the variation in pattern of LVF flow. Processes resulting in similar type of glacial landforms as in Himalaya, Antarctica, and parts of Alaska on Earth were widely identified and attributed to be the major cause that has led to shape the fretted terrain on Mars. We have also attempted to classify the different stages of Martian glacial activity, based on the nature of landforms observed in the study region. The morphological evidences and comparisons between the features on Earth and Mars ascertained that Mars has experienced extensive glaciation during the past, and has preserved the landforms on its surface resulting from multiple glacial epochs. © 2013 Elsevier Ltd.

He J.,Syracuse University | Acharyya K.,Planex Inc. | Vidali G.,Syracuse University
Astrophysical Journal | Year: 2016

We measured the binding energy of N2, CO, O2, CH4, and CO2 on non-porous (compact) amorphous solid water (np-ASW), of N2 and CO on porous ASW, and of NH3 on crystalline water ice. We were able to measure binding energies down to a fraction of 1% of a layer, thus making these measurements more appropriate for astrochemistry than the existing values. We found that CO2 forms clusters on the np-ASW surface even at very low coverages. The binding energies of N2, CO, O2, and CH4 decrease with coverage in the submonolayer regime. Their values at the low coverage limit are much higher than what is commonly used in gas-grain models. An empirical formula was used to describe the coverage dependence of the binding energies. We used the newly determined binding energy distributions in a simulation of gas-grain chemistry for cold cloud and hot-core models. We found that owing to the higher value of binding energy in the submonolayer regime, a fraction of all these ices remains for much longer and up to higher temperatures on the grain surface compared to the single value energies currently used in the astrochemical models. © 2016. The American Astronomical Society. All rights reserved.

Sinha R.K.,Planex Inc. | Murty S.V.S.,Planex Inc.
Journal of Geophysical Research E: Planets | Year: 2013

Glacial/periglacial landforms lying within impact craters on Mars have led to the identification of two mechanisms for their formation: (1) intermittent deposition of atmospherically emplaced snow/ice during past spin-axis/orbital conditions and (2) flow of debris-covered ice-rich deposits. The maximum presence of the young ice/snow-rich features (thermal contraction crack polygons, gullies, arcuate ridges, and lobate debris tongues) was observed on the pole-facing slope, indicating that this slope was the preferred site for ice/snow accumulation (during the last 10 Ma). In this study, we investigated 30 craters lying in the Alba Patera volcanic province in the latitudinal bands between 45°N and 32.4°N. Morphological comparison of the younger ice/snow-rich features in these craters led us to conclude that glacial/periglacial features in Alba Patera are mainly present within pole-facing slopes of craters lying within 45°N-39°N. The craters lying within 40.2°N-40°N did not show any glacial/periglacial features. We suggest that the formation of these young ice/snow-rich features follows the same orientation trends as those of other older (>10 Ma) glacial features (debris-covered ice/snow-rich large deposits at the base of the crater wall) in the region. The present work has revealed that the onset of physical processes that result in the formation of glacial/periglacial landforms is also dependent on the changes in elevation ranges of the investigated craters in Alba Patera. Our results confirm past inferences for accumulation of ice/snow on Mars and suggest that the period of ice/snow accumulation activity in Alba Patera occurred throughout the Amazonian and lasted until the recent past, i.e., 2.1-0.4 Ma. © 2013. American Geophysical Union. All Rights Reserved.

Varatharajan I.,Planex Inc. | Srivastava N.,Planex Inc. | Murty S.V.S.,Planex Inc.
Icarus | Year: 2014

A comparative assessment of the mineralogy of young basalts (~1.2Ga to ~2.8Ga) from the western nearside, Moscoviense basin, and the Orientale basin of the Moon has been made using Level 2 Moon Mineralogy Mapper (M3) data from the Chandrayaan-1 mission. Spectral data characteristics of the individual units have been generated from fresh small craters to minimize the complications due to space weathering. Representative spectra for individual units and the derived spectral parameters (band centers and integrated band depth ratio) have been used to study composition of these young basalts. A modified approach of Gaffey et al. (Gaffey, M.J., Cloutis, E.A., Kelley, M.S., Reed, K.L. [2002]. Mineralogy of asteroids. In: Asteroids III. The University of Arizona Press, Tucson, pp. 183-204) (for olivine-pyroxene mixtures) and the methodology of Adams (Adams, J.B. [1974]. J. Geophys. Res. 79, 4829-4836. (for interpreting pyroxene type) have been used to improve our understanding of the spectral behavior of these basalts. Most of the young basalts of Oceanus Procellarum are characterized by abundant olivines and they show complex volcanic history. Vast exposures of olivine concentrated units having higher abundance of olivine content than high-Ca pyroxenes are emplaced in the northern Oceanus Procellarum region. Mostly, they show distinct stratigraphic gradation with the immediately underlying units of relatively lower olivine content. The Moscoviense unit shows signatures of Fe-rich glasses along with clinopyroxenes. The basalts of Orientale basin are typically devoid of olivine and are rich in high-Ca pyroxene. Thus, mineralogy of these mare basalts which erupted during the late stage volcanism vary across the Moon's surface; however, broader observations reveal apparently higher FeO content in the younger basalts of western nearside and Orientale region. © 2014 Elsevier Inc.

Planex Inc. | Date: 2013-02-19

Battery charger; power distribution or control machines and apparatus, namely, electrical power distribution units; rotary converters; phase modifiers, namely, optical phase shifters; solar battery; rechargeable battery; batteries and solar cells; telecommunication cables for network; electric wires and cables; network camera; modem and network routers; parts for modems and network routers; accessories for modem and network routers in the nature of USB cables, power adapters, computer cables, and combination antenna and USB cables; radio transmitters; television signal distributor, namely, electronic television signal transmitters; adapter using cigarette light socket for automobiles as electrical power source for mobile phones; monitoring device comprised primarily of computer hardware and software for use in monitoring telephone communication and data communication networks; telecommunication devices and apparatus, namely, telecommunication switches; blank USB flash drives; USB adapter; connection hub for computer networks; electronic pens for visual display units and mobile phone display panels; computer-oriented interface card in the nature of an interface for a computer; electronic machines, apparatus and their parts, namely, Geiger counters; video game control pad converters; network evaluation equipment, namely, electronic meters for data transmission rates to determine data network capacity; measuring or testing machines and instruments, namely, battery testers, electrical circuit testers, and fuel pump testers. Electric lamps; other lighting apparatus, namely, chandeliers, book light and ceiling lights; household electrothermic appliances, namely, installations for heating and electric radiators. Providing information concerning commercial sales; business management analysis and business consultancy; marketing research; rental of advertisement space; advertising and publicity services; import-export agencies.

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