keyword
MENU ▼
Read by QxMD icon Read
search

geophysical

keyword
https://www.readbyqxmd.com/read/28618610/estimating-higher-order-structure-functions-from-geophysical-turbulence-time-series-confronting-the-curse-of-the-limited-sample-size
#1
Adam W DeMarco, Sukanta Basu
Utilizing synthetically generated random variates and laboratory measurements, we document the inherent limitations of the conventional structure function approach in limited sample size settings. We demonstrate that an alternative approach, based on the principle of maximum likelihood, can provide nearly unbiased structure function estimates with far less uncertainty under such unfavorable conditions. The superiority of this approach over the conventional approach does not diminish even in the case of strongly correlated samples...
May 2017: Physical Review. E
https://www.readbyqxmd.com/read/28616870/hazard-experience-geophysical-vulnerability-and-flood-risk-perceptions-in-a-postdisaster-city-the-case-of-new-orleans
#2
Kevin Fox Gotham, Richard Campanella, Katie Lauve-Moon, Bradford Powers
This article investigates the determinants of flood risk perceptions in New Orleans, Louisiana (United States), a deltaic coastal city highly vulnerable to seasonal nuisance flooding and hurricane-induced deluges and storm surges. Few studies have investigated the influence of hazard experience, geophysical vulnerability (hazard proximity), and risk perceptions in cities undergoing postdisaster recovery and rebuilding. We use ordinal logistic regression techniques to analyze experiential, geophysical, and sociodemographic variables derived from a survey of 384 residents in seven neighborhoods...
June 14, 2017: Risk Analysis: An Official Publication of the Society for Risk Analysis
https://www.readbyqxmd.com/read/28607347/living-microorganisms-change-the-information-shannon-content-of-a-geophysical-system
#3
Fiona H M Tang, Federico Maggi
The detection of microbial colonization in geophysical systems is becoming of interest in various disciplines of Earth and planetary sciences, including microbial ecology, biogeochemistry, geomicrobiology, and astrobiology. Microorganisms are often observed to colonize mineral surfaces, modify the reactivity of minerals either through the attachment of their own biomass or the glueing of mineral particles with their mucilaginous metabolites, and alter both the physical and chemical components of a geophysical system...
June 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28604621/development-of-a-rigid-one-meter-side-and-cooled-coil-sensor-at-77-k-for-magnetic-resonance-sounding-to-detect-subsurface-water-sources
#4
Jun Lin, Guanfeng Du, Jian Zhang, Xiaofeng Yi, Chuandong Jiang, Tingting Lin
Magnetic resonance sounding (MRS) using the Earth's magnetic field is a noninvasive and on-site geophysical technique providing quantitative characteristics of aquifers in the subsurface. When the MRS technology is applied in a mine or tunnel for advance detecting the source of water that may cause disastrous accident, spatial constraints limit the size of coil sensor and thus lower the detection capability. In this paper, a coil sensor for detecting the weak MRS signal is designed and the signal to noise (SNR) for the coil sensor is analyzed and optimized...
June 12, 2017: Sensors
https://www.readbyqxmd.com/read/28594342/development-and-testing-of-a-dual-accelerometer-vector-sensor-for-auv-acoustic-surveys
#5
Agni Mantouka, Paulo Felisberto, Paulo Santos, Friedrich Zabel, Mário Saleiro, Sérgio M Jesus, Luís Sebastião
This paper presents the design, manufacturing and testing of a Dual Accelerometer Vector Sensor (DAVS). The device was built within the activities of the WiMUST project, supported under the Horizon 2020 Framework Programme, which aims to improve the efficiency of the methodologies used to perform geophysical acoustic surveys at sea by the use of Autonomous Underwater Vehicles (AUVs). The DAVS has the potential to contribute to this aim in various ways, for example, owing to its spatial filtering capability, it may reduce the amount of post processing by discriminating the bottom from the surface reflections...
June 8, 2017: Sensors
https://www.readbyqxmd.com/read/28594021/phase-diagram-of-water-methane-by-first-principles-thermodynamics-discovery-of-mh-iv-and-mh-v-hydrates
#6
Xiaoxiao Cao, Yingying Huang, Xue Jiang, Yan Su, Jijun Zhao
Searching novel gas hydrates is an enduring topic of scientific investigations, owing to its outstanding implications on planetology, the origin of life and the exploitation of energy resources. Taking the methane-water system as a representative, we disclose two new dense methane hydrate phases (MH-IV and MH-V) using the Monte-Carlo packing algorithm and density-functional theory (DFT) optimization. Both of these methane clathrates with (CH4)(H2O)4 stoichiometry can be regarded as filled ices, since their hydrogen bond networks are closely related to that of ice i and ice XI, respectively...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28589089/reference-values-for-tsh-and-free-thyroid-hormones-in-healthy-pregnant-women-in-poland-a-prospective-multicenter-study
#7
Marta Kostecka-Matyja, Anna Fedorowicz, Ewa Bar-Andziak, Tomasz Bednarczuk, Monika Buziak-Bereza, Paulina Dumnicka, Maria Górska, Małgorzata Krasnodębska, Beata Niedźwiedzka, Dorota Pach, Marek Ruchała, Katarzyna Siewko, Bogdan Solnica, Jerzy Sowiński, Małgorzata Szelachowska, Małgorzata Trofimiuk-Müldner, Katarzyna Wachowiak-Ochmańska, Alicja Hubalewska-Dydejczyk
OBJECTIVES: The diagnosis and treatment of thyroid diseases in pregnant women remains a challenge. Various medical associations recommend establishing the reference intervals for thyroid hormones by a local laboratory. Considering differences within geophysical, socioeconomic conditions, and iodine prophylaxis in various populations, it is advisable to assess reference intervals for thyroid hormones specific to a region of residence. The objective was to assess trimester-specific reference intervals for TSH, fT3, and fT4 for pregnant women in the Polish population...
April 2017: European Thyroid Journal
https://www.readbyqxmd.com/read/28587255/a-forward-gps-multipath-simulator-based-on-the-vegetation-radiative-transfer-equation-model
#8
Xuerui Wu, Shuanggen Jin, Junming Xia
Global Navigation Satellite Systems (GNSS) have been widely used in navigation, positioning and timing. Nowadays, the multipath errors may be re-utilized for the remote sensing of geophysical parameters (soil moisture, vegetation and snow depth), i.e., GPS-Multipath Reflectometry (GPS-MR). However, bistatic scattering properties and the relation between GPS observables and geophysical parameters are not clear, e.g., vegetation. In this paper, a new element on bistatic scattering properties of vegetation is incorporated into the traditional GPS-MR model...
June 5, 2017: Sensors
https://www.readbyqxmd.com/read/28584081/postglacial-response-of-arctic-ocean-gas-hydrates-to-climatic-amelioration
#9
Pavel Serov, Sunil Vadakkepuliyambatta, Jürgen Mienert, Henry Patton, Alexey Portnov, Anna Silyakova, Giuliana Panieri, Michael L Carroll, JoLynn Carroll, Karin Andreassen, Alun Hubbard
Seafloor methane release due to the thermal dissociation of gas hydrates is pervasive across the continental margins of the Arctic Ocean. Furthermore, there is increasing awareness that shallow hydrate-related methane seeps have appeared due to enhanced warming of Arctic Ocean bottom water during the last century. Although it has been argued that a gas hydrate gun could trigger abrupt climate change, the processes and rates of subsurface/atmospheric natural gas exchange remain uncertain. Here we investigate the dynamics between gas hydrate stability and environmental changes from the height of the last glaciation through to the present day...
June 13, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28583602/effects-of-environmental-temperature-and-season-on-hair-coat-characteristics-physiologic-and-reproductive-parameters-in-shetland%C3%A2-pony-stallions
#10
Kathrin Schmidt, Katharina Deichsel, Rodrigo Arruda de Oliveira, Jörg Aurich, Natascha Ille, Christine Aurich
We hypothesized that housing of stallions in a thermoneutral temperature zone during autumn and winter does not only influence metabolism and hair shedding but also improves the characteristics of raw and processed semen. Fertile Shetland pony stallions were followed from October to June. This time coincided with the seasons autumn, winter and spring. Ponies were kept in outside paddocks (group CON, n = 8) or in indoor stables (group ST, n = 8) from October to March when ST stallions returned to outdoor paddocks, but ponies remained in the same groups...
July 15, 2017: Theriogenology
https://www.readbyqxmd.com/read/28572390/massive-blow-out-craters-formed-by-hydrate-controlled-methane-expulsion-from-the-arctic-seafloor
#11
K Andreassen, A Hubbard, M Winsborrow, H Patton, S Vadakkepuliyambatta, A Plaza-Faverola, E Gudlaugsson, P Serov, A Deryabin, R Mattingsdal, J Mienert, S Bünz
Widespread methane release from thawing Arctic gas hydrates is a major concern, yet the processes, sources, and fluxes involved remain unconstrained. We present geophysical data documenting a cluster of kilometer-wide craters and mounds from the Barents Sea floor associated with large-scale methane expulsion. Combined with ice sheet/gas hydrate modeling, our results indicate that during glaciation, natural gas migrated from underlying hydrocarbon reservoirs and was sequestered extensively as subglacial gas hydrates...
June 2, 2017: Science
https://www.readbyqxmd.com/read/28570921/airborne-gamma-ray-spectrometry-data-processing-using-1-5d-inversion
#12
Eugene Druker
Standard processing of Airborne Gamma-Ray Spectrometry data generally gives good results when the measurement conditions are almost constant within several footprint area sizes, with the possible exception of flight height variations in a small range. In practice, deviations, such as large or abrupt changes of flight height and/or rugged terrain are not so rare and lead to certain problems. This article proposes a different approach where the solutions of inverse problems are used for data processing. The approach is quite natural in the processing of field data measured along the flight lines: it explicitly takes into account 1...
May 29, 2017: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/28560338/high-seismic-attenuation-at-a-mid-ocean-ridge-reveals-the-distribution-of-deep-melt
#13
Zachary C Eilon, Geoffrey A Abers
At most mid-ocean ridges, a wide region of decompression melting must be reconciled with a narrow neovolcanic zone and the establishment of full oceanic crustal thickness close to the rift axis. Two competing paradigms have been proposed to explain melt focusing: narrow mantle upwelling due to dynamic effects related to in situ melt or wide mantle upwelling with lateral melt transport in inclined channels. Measurements of seismic attenuation provide a tool for identifying and characterizing the presence of melt and thermal heterogeneity in the upper mantle...
May 2017: Science Advances
https://www.readbyqxmd.com/read/28553258/an-overview-of-monthly-rhythms-and-clocks
#14
REVIEW
Florian Raible, Hiroki Takekata, Kristin Tessmar-Raible
Organisms have evolved to cope with geophysical cycles of different period lengths. In this review, we focus on the adaptations of animals to the lunar cycle, specifically, on the occurrence of biological rhythms with monthly (circalunar) or semi-monthly (circasemilunar) period lengths. Systematic experimental investigation, starting in the early twentieth century, has allowed scientists to distinguish between mythological belief and scientific facts concerning the influence of the lunar cycle on animals. These studies revealed that marine animals of various taxa exhibit circalunar or circasemilunar reproductive rhythms...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28550951/geophysical-features-influence-the-accumulation-of-beach-debris-on-caribbean-islands
#15
Alexandra M Schmuck, Jennifer L Lavers, Silke Stuckenbrock, Paul B Sharp, Alexander L Bond
Anthropogenic beach debris was recorded during beach surveys of 24 Caribbean islands during April 2014-April 2016. Beach debris was classified according to material type (e.g., polystyrene) and item use (e.g., fishing). Geophysical features (substrate type, beach direction, and human accessibility) of sample sites were recorded in order to investigate their relationship with debris density. Results suggest the density of macro debris (items >5mm) is highest on uninhabited, sandy beaches facing a leeward direction...
May 24, 2017: Marine Pollution Bulletin
https://www.readbyqxmd.com/read/28543228/scenario-evaluator-for-electrical-resistivity-survey-pre-modeling-tool
#16
Neil Terry, Frederick D Day-Lewis, Judith L Robinson, Lee D Slater, Keith Halford, Andrew Binley, John W Lane, Dale Werkema
Geophysical tools have much to offer users in environmental, water resource, and geotechnical fields; however, techniques such as electrical resistivity imaging (ERI) are often oversold and/or overinterpreted due to a lack of understanding of the limitations of the techniques, such as the appropriate depth intervals or resolution of the methods. The relationship between ERI data and resistivity is nonlinear; therefore, these limitations depend on site conditions and survey design and are best assessed through forward and inverse modeling exercises prior to field investigations...
May 23, 2017: Ground Water
https://www.readbyqxmd.com/read/28535602/quantifying-postglacial-sediment-storage-and-denudation-rates-in-a-small-alpine-catchment-of-the-f%C3%A4-g%C3%A4-ra%C3%A8-mountains-romania
#17
Adrian C Ardelean, Alexandru Onaca, Petru Urdea, Adriana Sărășan
The study of sediment production, transport, storage and discharge in alpine drainage basins is an essential prerequisite for a better understanding of the postglacial evolution of the alpine landscape. To get an overview on sediment production and alpine landscape evolution in Romania, the current study presents the first alpine sediment storage quantification in the Romanian Carpathians. Postglacial denudation was quantified within the small alpine catchment of the Doamnei Valley (3.62km(2)), located in the central part of the Făgăraș Mountains...
December 1, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28531969/biogeographical-factors-affecting-the-distribution-of-stream-salamanders-on-the-cumberland-plateau-usa
#18
P R Gould, K K Cecala, S S Drukker, B A McKenzie, C Van de Ven
Geophysical and climate conditions play an important role in the distribution of organisms at both fine and broad scales. Headwater streams integrate changes at broad geographical scales and serve as important regions of nutrient processing and support high biodiversity. Stream salamanders are important members of headwater aquatic communities as both predators and prey. Combined with their biphasic life histories and physiological requirements, stream amphibians may serve as indicators for headwater stream conditions...
December 1, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28506427/italy-introduces-pre-and-post-operation-monitoring-phases-for-offshore-seismic-exploration-activities
#19
C Fossati, B Mussi, R Tizzi, G Pavan, D S Pace
Concern is growing that marine fauna can be affected by noise such as naval sonar, pile driving or geophysical surveys, among others. Literature reports a variety of animal reactions to human noise (from apparently null or negligible to strong). However, conclusive results on its effects on marine mammals at individual and population level are still lacking. In 2015, the Italian Environmental Impact Assessment Commission mandated seismic operators apply a standard scientific protocol comparing marine mammal presence before, during, and after offshore seismic survey...
May 12, 2017: Marine Pollution Bulletin
https://www.readbyqxmd.com/read/28505811/chaotic-lagrangian-models-for-turbulent-relative-dispersion
#20
Guglielmo Lacorata, Angelo Vulpiani
A deterministic multiscale dynamical system is introduced and discussed as a prototype model for relative dispersion in stationary, homogeneous, and isotropic turbulence. Unlike stochastic diffusion models, here trajectory transport and mixing properties are entirely controlled by Lagrangian chaos. The anomalous "sweeping effect," a known drawback common to kinematic simulations, is removed through the use of quasi-Lagrangian coordinates. Lagrangian dispersion statistics of the model are accurately analyzed by computing the finite-scale Lyapunov exponent (FSLE), which is the optimal measure of the scaling properties of dispersion...
April 2017: Physical Review. E
keyword
keyword
52720
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"