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Laxman Khanal, Mukesh K Chalise, Kai He, Bipin K Acharya, Yoshi Kawamoto, Xuelong Jiang
Genetic diversity of a species is influenced by multiple factors, including the Quaternary glacial-interglacial cycles and geophysical barriers. Such factors are not yet well documented for fauna from the southern border of the Himalayan region. This study used mitochondrial DNA (mtDNA) sequences and ecological niche modeling (ENM) to explore how the late Pleistocene climatic fluctuations and complex geography of the Himalayan region have shaped genetic diversity, population genetic structure, and demographic history of the Nepalese population of Assam macaques (Macaca assamensis) in the Himalayan foothills...
March 14, 2018: American Journal of Primatology
Xiaofeng Yi, Jian Zhang, Tiehu Fan, Baofeng Tian, Chuandong Jiang
Magnetic resonance sounding (MRS) is a novel geophysical method to detect groundwater directly. By applying this method to underground projects in mines and tunnels, warning information can be provided on water bodies that are hidden in front prior to excavation and thus reduce the risk of casualties and accidents. However, unlike its application to ground surfaces, the application of MRS to underground environments is constrained by the narrow space, quite weak MRS signal, and complex electromagnetic interferences with high intensities in mines...
March 13, 2018: Sensors
N Valiente, R Carrey, N Otero, A Soler, D Sanz, A Muñoz-Martín, F Jirsa, W Wanek, J J Gómez-Alday
Endorheic or closed drainage basins in arid and semi-arid regions are vulnerable to pollution. Nonetheless, in the freshwater-saltwater interface of endorheic saline lakes, oxidation-reduction (redox) reactions can attenuate pollutants such as nitrate (NO3 - ). This study traces the ways of nitrogen (N) removal in the Pétrola lake-aquifer system (central Spain), an endorheic basin contaminated with NO3 - (up to 99.2mg/L in groundwater). This basin was declared vulnerable to NO3 - pollution in 1998 due to the high anthropogenic pressures (mainly agriculture and wastewaters)...
March 10, 2018: Science of the Total Environment
Stefan Iglauer, Maxim Lebedev
Physical, chemical and mechanical pore-scale (i.e. micrometer-scale) mechanisms in rock are of key importance in many, if not all, subsurface processes. These processes are highly relevant in various applications, e.g. hydrocarbon recovery, CO2 geo-sequestration, geophysical exploration, water production, geothermal energy production, or the prediction of the location of valuable hydrothermal deposits. Typical examples are multi-phase flow (e.g. oil and water) displacements driven by buoyancy, viscous or capillary forces, mineral-fluid interactions (e...
December 28, 2017: Advances in Colloid and Interface Science
R Di Maio, S Fais, P Ligas, E Piegari, R Raga, R Cossu
As it is well-known, the characterization plan of an old landfill site is the first stage of the project for the treatment and reclamation of contaminated lands. It is a preliminary in-situ study, with collection of data related to pollution phenomena, and is aimed at defining the physical properties and the geometry of fill materials as well as the possible migration paths of pollutants to the surrounding environmental targets (subsoil and groundwater). To properly evaluate the extent and potential for subsoil contamination, waste volume and possible leachate emissions from the landfill have to be assessed...
March 7, 2018: Waste Management
Sha Jiang, Xiaolan Qiu, Bing Han, Wenlong Hu
The GaoFen-3 (GF-3) satellite, launched on 10 August 2016, is the first C-band polarimetric synthetic aperture radar (PolSAR) satellite in China. The PolSAR system of GF-3 can collect a significant wealth of information for geophysical research and applications. Being used for related applications, GF-3 PolSAR images must be of good quality. It is necessary to evaluate the quality of polarimetric data and achieve the normalized quality monitoring during 8-year designed life of GF-3. In this study, a new quality assessment method of PolSAR data based on common distributed targets is proposed, and the performance of the method is analyzed by simulations and GF-3 experiments...
March 7, 2018: Sensors
Valery Levitas
High pressure phase transformations play an important role in the search for new materials and material synthesis, as well as in geophysics. However, they are poorly characterized, and phase transformation pressure and pressure hysteresis vary drastically in experiments of different researchers, with different pressure transmitting media, and with different material suppliers. Here we review the current state, challenges in studying phase transformations under high pressure, and the possible ways in overcoming the challenges...
March 7, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Neil Terry, Frederick D Day-Lewis, Dale Werkema, John W Lane
Non-invasive geophysical estimation of soil moisture has potential to improve understanding of flow in the unsaturated zone for problems involving agricultural management, aquifer recharge, and optimization of landfill design and operations. In principle, several geophysical techniques (e.g., electrical resistivity, electromagnetic induction, nuclear magnetic resonance) offer insight into soil moisture, but data-analysis tools are needed to 'translate' geophysical results into estimates of soil moisture, consistent with (1) the uncertainty of this translation and (2) direct measurements of moisture...
March 6, 2018: Ground Water
Sung-Ik Sohn, Takashi Sakajo, Sun-Chul Kim
We study the stability of a barotropic vortex strip on a rotating sphere, as a simple model of jet streams. The flow is approximated by a piecewise-continuous vorticity distribution by zonal bands of uniform vorticity. The linear stability analysis shows that the vortex strip becomes stable as the strip widens or the rotation speed increases. When the vorticity constants in the upper and the lower regions of the vortex strip have the same positive value, the inner flow region of the vortex strip becomes the most unstable...
February 2018: Proceedings. Mathematical, Physical, and Engineering Sciences
Qing Liao, Yaping Deng, Xiaoqing Shi, Yuanyuan Sun, Weidong Duan, Jichun Wu
Precise delineation of contaminant plume distribution is essential for effective remediation of contaminated sites. Traditional in situ investigation methods like direct-push (DP) sampling are accurate, but are usually intrusive and costly. Electrical resistivity tomography (ERT) method, as a non-invasive geophysical technique to map spatiotemporal changes in resistivity of the subsurface, is becoming increasingly popular in environmental science. However, the resolution of ERT for delineation of contaminant plumes still remains controversial...
March 3, 2018: Environmental Monitoring and Assessment
Haesang Yang, Woojae Seong
Compressional wave speed and attenuation were measured for water-saturated granular media employing five kinds of glass beads having unimodal and bimodal grain size distributions. Glass beads with grain sizes ranging from 250 to 850  μm were used for the acoustic measurements at a frequency range from 350 kHz to 1.1 MHz, which includes the transition range where scattering and non-scattering losses co-exist. The compressional wave speed and attenuation data are presented as a function of frequency and grain size distribution...
February 2018: Journal of the Acoustical Society of America
Eugene Druker
The acquisition of information from the airborne gamma-ray spectra is based on the ability to evaluate photopeak areas in regular spectra from natural and other sources. In airborne gamma-ray spectrometry, extraction of photopeaks of radionuclides from regular one-second spectra is a complex problem. In the region of higher energies, difficulties are associated with low signal level, i.e. low count rates, whereas at lower energies difficulties are associated with high noises due to a high signal level. In this article, a new procedure is proposed for processing the measured spectra up to and including the extraction of evident photopeaks...
February 26, 2018: Journal of Environmental Radioactivity
M Petrelli, K El Omari, L Spina, Y Le Guer, G La Spina, D Perugini
Water plays a key role in magma genesis, differentiation, ascent and, finally, eruption. Despite the recognized crucial function of water, there are still several issues that continue to blur our view about its role in magmatic systems. What are the timescales of H2 O accumulation in crystallizing magmas? What are the ascent rates of water-rich residual melts leading to explosive eruptions? Here, we track the timescale of water accumulation in a residual melt resulting from crystallization of a hydrous CO2 -bearing magmatic mass stored at mid- to deep-crustal levels in a subduction-related geodynamic setting...
February 22, 2018: Nature Communications
Susan M Cormier, Lei Zheng, Gretchen Hayslip, Colleen M Flaherty
The concentration of salts in streams is increasing world-wide making freshwater a declining resource. Developing thresholds for freshwater with low specific conductivity (SC), a measure of dissolved ions in water, may protect high quality resources that are refugia for aquatic life and that dilute downstream waters. In this case example, methods are illustrated for estimating protective levels for streams with low SC. The Cascades in the Pacific Northwest of the United States of America was selected for the case study because a geophysical model indicated that the SC of freshwater streams was likely to be very low...
February 19, 2018: Science of the Total Environment
Mauro Castelluccio, Sudha Agrahari, Gabriele De Simone, Francesca Pompilj, Carlo Lucchetti, Debashish Sengupta, Gianfranco Galli, Pierluigi Friello, Pierpaolo Curatolo, Riccardo Giorgi, Paola Tuccimei
Geochemical and geophysical surveys employing radon deficit, resistivity, and induced polarization (IP) measurements were undertaken on soil contaminated with non-aqueous phase liquids (NAPLs) in two different sites in India and in Italy. Radon deficit, validated through the comparison with average soil radon in reference unpolluted areas, shows the extension of contamination in the upper part of the unsaturated aquifers. In site 1 (Italy), the spill is not recent. A residual film of kerosene covers soil grains, inhibiting their chargeability and reducing electrical resistivity difference with background unpolluted areas...
February 20, 2018: Environmental Science and Pollution Research International
Masoud Saatsaz, Iman Monsef, Mostafa Rahmani, Abdolreza Ghods
Because of the outdated methods of common landfill selection, it is imperative to reevaluate the usage suitability. To assess the suitability of the existing waste landfill in Zanjan, Iran, we have used a combination of the analytical hierarchy process (AHP) and GIS techniques, along with fieldwork surveys. Four major criteria and 12 subcriteria were considered, and the AHP was applied to assign the relative importance weights of criteria and subcriteria to each other. Finally, a landfill suitability map was generated and ranked based on the final suitability scores...
February 16, 2018: Environmental Monitoring and Assessment
Fulong Jing, Chunjie Zhang, Weijian Si, Yu Wang, Shuhong Jiao
Polynomial phase signals (PPSs) have numerous applications in many fields including radar, sonar, geophysics, and radio communication systems. Therefore, estimation of PPS coefficients is very important. In this paper, a novel approach for PPS parameters estimation based on adaptive short-time Fourier transform (ASTFT), called the PPS-ASTFT estimator, is proposed. Using the PPS-ASTFT estimator, both one-dimensional and multi-dimensional searches and error propagation problems, which widely exist in PPSs field, are avoided...
February 13, 2018: Sensors
Hechuan Jiang, Xiaojue Zhu, Varghese Mathai, Roberto Verzicco, Detlef Lohse, Chao Sun
In this combined experimental and numerical study on thermally driven turbulence in a rectangular cell, the global heat transport and the coherent flow structures are controlled with an asymmetric ratchetlike roughness on the top and bottom plates. We show that, by means of symmetry breaking due to the presence of the ratchet structures on the conducting plates, the orientation of the large scale circulation roll (LSCR) can be locked to a preferred direction even when the cell is perfectly leveled out. By introducing a small tilt to the system, we show that the LSCR orientation can be tuned and controlled...
January 26, 2018: Physical Review Letters
Y Bidel, N Zahzam, C Blanchard, A Bonnin, M Cadoret, A Bresson, D Rouxel, M F Lequentrec-Lalancette
Measuring gravity from an aircraft or a ship is essential in geodesy, geophysics, mineral and hydrocarbon exploration, and navigation. Today, only relative sensors are available for onboard gravimetry. This is a major drawback because of the calibration and drift estimation procedures which lead to important operational constraints. Atom interferometry is a promising technology to obtain onboard absolute gravimeter. But, despite high performances obtained in static condition, no precise measurements were reported in dynamic...
February 12, 2018: Nature Communications
Gianbattista Bussi, Paul G Whitehead, Cayetano Gutiérrez-Cánovas, José L J Ledesma, Steve J Ormerod, Raoul-Marie Couture
Interactions between climate change and land use change might have substantial effects on aquatic ecosystems, but are still poorly understood. Using the Welsh River Wye as a case study, we linked models of water quality (Integrated Catchment - INCA) and climate (GFDL - Geophysical Fluid Dynamics Laboratory and IPSL - Institut Pierre Simon Laplace) under greenhouse gas scenarios (RCP4.5 and RCP8.5) to drive a bespoke ecosystem model that simulated the responses of aquatic organisms. The potential effects of economic and social development were also investigated using scenarios from the EU MARS project (Managing Aquatic Ecosystems and Water Resources under Multiple Stress)...
February 1, 2018: Science of the Total Environment
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