26 research outputs found

    Atmospheric, Geomorphological, and Compositional Analysis of Martian Asimov and Hale Craters: Implications for Recurring Slope Lineae

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    Recurring slope lineae (RSL) are small, dark, seasonal albedo features lengthening down “warm” Martian steep slopes. Their origin has been attributed to both liquid and dry processes, hence representing one of the major open science questions on present day Mars. In the present study, we report a catalog of previous literature and newly added RSL sites making a total of 940 sites globally on Mars along with the detailed geological and compositional investigation of the Hale and Asimov craters with their RSL features. We also estimate temperature and atmospheric water abundances in the study area, which are two of the main factors to explain the origin and formation of RSL. The study found that the Asimov crater’s local temperatures are high enough to allow either the melting of brines or deliquescence of calcium perchlorate and other salts during the HiRISE observation period and found the water vapor column to be nearly five times higher than those measured “before RSL appearance.” This supports the theory of deliquescence as one of the mechanisms for the regolith-atmosphere interaction and RSL formation in the studied crater, which suggests that minerals absorb moisture from the environment until the minerals dissolve in the absorbed water and yield a solution. We also used compact reconnaissance imaging spectrometer for Mars–derived browse products for a compositional study associated with RSL features hosting craters and surface characteristics of Mars

    Remote sensing and GIS based approaches to estimate evapotranspiration in the arid and semi-arid regions

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    In this paper we used two methodologies of remote sensing data and its derived variables for the estimation of Evapotranspiration (ET). In the first method, the sensible heat flux was calculated by combining air temperature and the remotely sensed surface temperature using Thornthwaite method. We applied and evaluated the ET successfully in the AlAin area of United Arab Emirates. In the Second method, vegetation index derived using Landsat 8 OLI was used for the determination of surface resistance for latent heat. To derive the predicted ET using Normalized Difference Vegetation Index (NDVI), regression analyses were conducted between data derived from satellites, published field meteorological stations data and ET values. From the collected variables of interest, we have also studied the bivariant density estimation curves. It is evident from the patterns of multimodal data that the data belong to different locations with different ET status. It was also observed that wind velocity (U) seems to be decreasing with increasing ET and rest all variable were increasing with increasing ET, which depend on the saturation vapor pressure (SVP). From this approach, we confirmed that the prediction of ET is achievable from the remote sensing data. It is also confirmed that the predicted ET results gained from the NDVI regression functions were comparable to the ET values obtained by the previously published field data. The results showed that indirect application of remotely sensed vegetation index could be used for the ET determination

    Meteorology of the Red Planet by dust devils

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    Many dust devils were detected by high resolution camera images on the surface of mars, that is remarkably similar in arid regions on Earth. The dust devils result from sunshine warming the ground, prompting convective rising of air. The hot air rises and begins to spin faster and faster as it compresses. The dust devils may serve a major role in the meteorology of the Red Planet. However, the derive scaling relations between dust devil radius, pressure profiles, wind speeds, and heights have remained unclear. In this work, we test a dust devil theoretical model that identify a relationship between these parameters. To do this, we used data which provides diameters and heights at different seasons. We extended the theoretical model by proposing an equation that estimate the eyewall velocity from a dust devil\u27s height

    Application of hyperspectral imaging technique to determine the quality of Photo and Thermal exposed and contaminated pharmaceutical formulations: A cost effective way of quality testing

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    Hyperspectral imaging is one of the recent technologies in the field of quality testing of pharmaceutical products. The present study describes the spectral behavior of two Active Pharmaceutical Ingredients (API) at photo and thermal stressed conditions and the contamination on the surface. We aim to study how the hyperspectral technique can measure the physical and chemical changes of pharmaceutical ingredients at stressed conditions. Multispectral and hyperspectral cameras were used for qualitative data collection of thousands of spectra. Results were compared with traditional UV and XRD methods. Implementation of such non-destroying, non-polluting, eco-friendly and fast technology will be useful in the pharmaceutical manufacturing, packing and reaction monitoring. Hyperspectral technology will be useful in the future space explorations for a better understanding of drug stability, safety, and effectiveness in space

    Geospatial Assessment of Groundwater Quality with the Distinctive Portrayal of Heavy Metals in the United Arab Emirates

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    Groundwater is a valuable resource, and its quality is critical to human survival. Optimal farming and urbanization degraded groundwater reserves. This research investigates and reports the spatial variability of selected heavy metals developed in the Liwa area of the United Arab Emirates. Forty water samples were collected from existing wells and analyzed for different elements. Principal components analysis was applied to a subgroup of the data set in terms of their usefulness for determining the variability of groundwater quality variables. Geographic information systems were used to produce contour maps to analyze the distribution of heavy metals. Ordinary kriging was used with Circular, Spherical, Tetraspherical, Pentaspherical-Bessel, K-Bessel, Hole effect, and Stable models for better representation. The water quality index was constructed using heavy metal concentrations and other variables. This yielded a value of 900 beyond the limit stated by WHO and US EPA. Nugget analysis showed that Cd (0), K (7.38%), and SO4 (1.81%) variables exhibited strong spatial dependence. Al (27%), Ba (40.87%), Cr (63%), Cu (34%), EC (27%), HCO3 (56%), NO3 (36%), Pb (64%), and TDS (53%) represented moderate spatial dependence. As (76%), Mn (79%), Ni (100%), pH (100%), Temp (93%), and Zn (100%) exhibited weak spatial dependence

    Characterization of biochar produced from Al Ghaf Tree for CO2 Capture

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    Climate change, global warming, and rise in water levels are environmental problems caused by the high emissions of greenhouse gases, and the most harmed one is carbon dioxide. Biochar is a material produced by thermochemical conversions with oxygen-depleted conditions of organic materials, and this process calls pyrolysis. Recently, it has been evaluated as a carbon dioxide capture, and its porous structure, structural properties, and production methods are easy. Al Ghaf (Prosopis cineraria) tree is one of the United Arab Emirates’ national trees with a wide range of intriguing properties, including high nutritional value, medicinal/pharmaceutical potential, and biosorption. This paper focuses on the biochar synthesized from three parts of the Al Ghaf tree: leaves, roots, and branches, to determine which part can achieve the maximum carbon dioxide capture. The ability of the produced biochar to capture carbon dioxide was tested through direct gas–solid​ interaction inside an integrated fluidized bed reactor. The carbon dioxide adsorption capacity was expressed by two methods related to (a) the loaded biochar mass and (b) the total amount of carbon dioxide fed to the reactor. The carbon dioxide adsorption capacity results concerning the loaded mass were 6.88%, 5.50%, and 3.63% for leaves, roots, and branches, respectively. At the same time, the results based on the total amount of carbon dioxide fed were 65.5%, 58.7%, and 37.7% for leaves, roots, and branches, respectively. Such results were confirmed by the physicochemical characteristics of the synthesized biochar using Scanning Electron Microscopy with Energy Dispersive X-ray Analysis, Thermogravimetric analysis (TGA), and X-ray diffraction analysis. Al Ghaf tree requires further study and inquiry to identify the most appropriate applications

    An Investigation on the Morphological and Mineralogical Characteristics of Posidonius Floor Fractured Lunar Impact Crater Using Lunar Remote Sensing Data

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    Lunar floor‐fractured craters (FFCs) are a distinguished type of crater found on the surface of the Moon with radial, concentric, and/or polygonal fractures. In the present study, we selected the Posidonius FCC to explore the mineralogy, morphology and tectonic characteristics using remote sensing datasets. The Posidonius crater is vested with a wide moat of lava separating the crater rim inner wall terraces from the fractured central floor. Lunar Reconnaissance Orbiter’s (LRO) images and Digital Elevation Model (DEM) data were used to map the tectonics and morphology of the present study. The Moon Mineralogy Mapper (M3) data of Chandrayaan‐1 were used to inves-tigate the mineralogy of the region through specified techniques such as integrated band depth, band composite and spectral characterization. The detailed mineralogical analysis indicates the nor-itic‐rich materials in one massif among four central peak rings and confirm intrusion (mafic pluton). Spectral analysis from the fresh crater of the Posidonius moat mare unit indicates clinopyroxene pigeonite in nature. Integrated studies of the mineralogy, morphology and tectonics revealed that the study region belongs to the Class‐III category of FFCs. The lithospheric loading by adjacent volcanic load (Serenitatis basin) generates a stress state and distribution of the fracture system

    Delineation of Copper Mineralization Zones at Wadi Ham, Northern Oman Mountains, United Arab Emirates Using Multispectral Landsat 8 (OLI) Data

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    © Copyright © 2020 Howari, Ghrefat, Nazzal, Galmed, Abdelghany, Fowler, Sharma, AlAydaroos and Xavier. Copper deposits in the ultramafic rocks of the Semail ophiolite massifs is found to be enormous in the region of northern Oman Mountains, United Arab Emirates. For this study, samples of copper were gathered from 14 different sites in the investigation area and were analyzed in the laboratory using the X-ray diffraction, GER 3700 spectroradiometer, and Inductively Coupled Plasma-Mass Spectrometer. Detection and mapping of copper-bearing mineralized zones were carried out using different image processing approaches of minimum noise fraction, principal component analysis, decorrelation stretch, and band ratio which were applied on Landsat 8 (OLI) data. The spectra of malachite and azurite samples were characterized by broad absorption features in the visible and near infrared region (0.6–1.0 ”m). The results obtained from the principal component analysis, minimum noise fraction, band ratio, decorrelation stretch, spectral reflectance analyses, and mineralogical and chemical analyses were found to be similar. Thus, it can be concluded that multispectral Landsat 8 data are useful in the detection iron ore deposits in arid and semi-arid regions

    Synthesis, Crystal structure, DFT calculations and antimicrobial activity of 4-(4-fluoro-phenyl)-2,6-dimethyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester

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    The title compound was synthesized and confirmed by FT-IR, 1H, 13C NMR analysis. The molecular structure of the compound was precisely determined by Single Crystal X-ray Diffraction (SC-XRD) analysis. The crystalized compound shows P21/C & monoclinic crystal system with cell parameters a = 9.7768 (5), b = 7.4005(3) and c = 24.8099 (12), ÎČ=93.734(2)°.The structural and electronic properties of the compound were carried out by Density Functional Theory (DFT) calculations. The compound exhibited H-bonding between N1-H1A-O1 with bond distance 2.98(7) A°).The energy gap Egap 4.53eV and Egap= 4.34eV for crystal and DFT method respectively. The molecular orbitals energies were studied through Highest Unoccupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) analysis. The softness and hardness of the molecule was studied through Global Chemical Reactivity Descriptors (GCRD). The electrophilic and nucleophilic characters were studied through Molecular Electrostatic Potential (MEP) studies. The antimicrobial studies were carried out by in-vitro method against 6 microorganisms

    Changes in the Invasion Rate of Prosopis juliflora and Its Impact on Depletion of Groundwater in the Northern Part of the United Arab Emirates

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    Prosopis species were introduced to the United Arab Emirates (UAE) region for desert greening. However, the species now pose a great threat to the native plant diversity. This study used high-resolution satellite imagery (1990–2019) to understand the history and current distribution of Prosopis species and their impact on fresh groundwater. The results show that the Prosopis invasion in the study area reached its maximum expansion rate in 2019 and covered an area of about 16 km2 compared to 0.2 km2 in 1990. The areas near Sharjah Airport, Umm Fannan, and Al Talla, located at a lower elevation of the sand dune area, are heavily invaded. Prosopis groundwater requirement derived using evapotranspiration shows that groundwater consumption has changed drastically after 2010 and consumed about 22.22 million m3 of groundwater in 2019, which is about a 7372% increase in groundwater consumption from the year 1990 to 2019. The results can be useful for setting up a management plan for the sustainable use of this species in the UAE region in particular and other similar countries in the arid land regions that are suffering from freshwater depletion because of Prosopis invasion
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