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logging, etc ; elasticities; models; production functions; Show all 4 Subjects
Abstract:
... We propose a semiparametric varying coefficient estimator for a Cobb–Douglas production function for panel data with several practical features. First, we estimate the model without a log transformation to avoid induced non-negligible estimation bias. Second, we disentangle the impact of traditional inputs from that of environment variables, which impact output indirectly through altering the outp ...
geophysical logging, etc ; geophysics; models; tectonics; Italy; Show all 5 Subjects
Abstract:
... The geoelectrical features of the Travale geothermal field (Italy), one of the most productive geothermal fields in the world, have been investigated by means of three-dimensional (3D) magnetotelluric (MT) data inversion. This study presents the first resistivity model of the Travale geothermal field derived from derivative-based 3D MT inversion. We analyzed MT data that have been acquired in Trav ...
logging, etc ; application parameters; climatic zones; environmental science; frequency; testing; Show all 6 Subjects
Abstract:
... The aim of this work is to analyse and compare different methodologies to fill gaps in early precipitation series, and to evaluate which time resolution is reachable, i.e. monthly or daily one. The following methods are applied and tested to fill the 1764–1767 gap in the precipitation series of Padua: (1) using a relationship between monthly amounts and frequencies; (2) transforming a daily log wi ...
logging, etc ; environment; equipment; exhibitions; fields; image analysis; remote sensing; Show all 7 Subjects
Abstract:
... In this paper, a universal multi–frequency micro-resistivity array imaging (UMMAI) system for subsurface sensing is developed and verified. Different from conventional micro-resistivity imaging equipments, UMMAI is capable to provide high-resolution fullbore formation images in multiple logging environments including an oil-based mud scene, water-based mud scene and water-oil mixed mud scene, owni ...
geophysical logging, etc ; Mesozoic era; algorithms; basins; geophysics; gravity; models; sediments; topography; Show all 9 Subjects
Abstract:
... Multi layer 3D gravity inversion for layered structures and density interfaces are performed in the Central Main Ethiopian rift bounded between 38⁰00′–39⁰30′ E and 7⁰00′–8⁰30′ N. The inversion is carried out in wave number domain using Parker-Oldenburg algorithm and is constrained with initial model information. The previous studies in the region focused on mapping crustal structures and Moho dept ...
logging, etc ; Americans; Bayesian theory; data analysis; empirical research; journals; normal distribution; selection methods; Show all 8 Subjects
Abstract:
... In a thought-provoking paper, Efron investigated the merit and limitation of an empirical Bayes method to correct selection bias based on Tweedie’s formula first reported in the study by Robbins. The exceptional virtue of Tweedie’s formula for the normal distribution lies in its representation of selection bias as a simple function of the derivative of log marginal likelihood. Since the marginal l ...
geophysical logging, etc ; energy; gas hydrate; geophysics; hydrodynamics; prediction; sand; thermodynamics; topographic slope; Alaska; Show all 10 Subjects
Abstract:
... Geological reservoir characterization is essential for accurate evaluation of gas production performance from gas hydrate reservoirs. Particularly, the understanding of reservoir architecture and heterogeneity is of great importance since these are considered as major controls on fluid hydrodynamic and thermodynamic conditions. This study deals with well log and three-dimensional (3-D) vertical se ...
logging, etc ; Ixodes persulcatus; Siphonaptera; death; hosts; lice; parasitic mites; small mammals; trapping; traps; Show all 10 Subjects
Abstract:
... This paper presents comparative assessment of the timing of host abandonment by different taxa of ectoparasites of small mammals after the host has been captured in a regular snap trap. The data were obtained using a specially designed trap line with automatic logging of the capture time. Our results generally support the basic rule that ectoparasites eventually abandon the dead host. The most tan ...
geophysical logging, etc ; Permian period; basins; freshwater; models; oils; tectonics; wastewater; Delaware; New Mexico; Texas; Show all 11 Subjects
Abstract:
... A flat, large, semi-arid plateau in the southwest United States (west Texas and southeast New Mexico) underlain by a deep Paleozoic sedimentary basin, the tectonic Delaware Basin, host of intensive hydrocarbon production. Impacts of injection of large volumes of water produced from oil and gas wells and injected through 1000 + disposal wells, in particular, pressure buildup, induced seismicity and ...
geophysical logging, etc ; basins; carbon dioxide; carbonate rocks; computers; geophysics; mineralization; models; permeability; seals; Georgia; Show all 11 Subjects
Abstract:
... Over the past few decades, measured levels of atmospheric carbon dioxide have substantially increased. One of the ways to limit the adverse impacts of increased carbon dioxide concentrations is to capture and store it inside Earth's subsurface, a process known as CO₂ sequestration. The success of this method is critically dependent on the ability to confine injected CO₂ for up to thousands of year ...
... Fire regimes are changing in several regions of the world. In those regions, some exotic species may be better adapted to new regimes than the native species. This study focused on identifying the microsite characteristics associated with the occurrence of post-fire Eucalyptus globulus regeneration from seeds, outside the species native-range. This information is important in helping to assess the ...
... This study attempts to provide a more precise and comprehensive model for stream-wise velocities in turbulent smooth-wall open channel flows. Velocity profiles are obtained from the resolution of two ordinary differential equations. The first is derived from the Reynolds-averaged Navier-Stokes (RANS) equation while the second is from the equilibrium between turbulent kinetic energy (TKE) productio ...
... The Latrobe Group in the Gippsland Basin consists of well-developed, stacked shoreface and coastal plain deposits, cut by large, incised channel systems up to 500 m deep. These large channels are conspicuous on seismic intersections and have previously been interpreted as the result of fluvial incision associated with basin inversion/compressional tectonics. Here we have used 3D seismic, well log, ...
geophysical logging, etc ; anhydrite; anisotropy; case studies; dolomite; dolomitic limestone; effective porosity; isotropy; oils; permeability; shale; Egypt; Show all 12 Subjects
Abstract:
... Understanding basic petrophysical properties may enhance the recovery of residual oil saturation and help in reservoir management. Reservoir oil saturation is the fraction of the porosity of a zone occupied by oil. The trapping may increase with the increase of porosity. Oil reservoirs represent a significant fraction of the reservoirs in the world-wide. We try to make a reservoir evaluation using ...
geophysical logging, etc ; Devonian period; basins; carbonates; data collection; gravity; models; mudstone; periodicity; sea level; starvation; topography; Alberta; Show all 13 Subjects
Abstract:
... In organic-rich mudstones, vertical sequences of sedimentary facies record the depositional responses to complex and varying controls: development of accommodation, redox conditions and multiple sources of detrital and biogenic sediments whose flux varies with relative sea-level, and reworking by bottom currents. In this study of the Upper Devonian Duvernay Formation in the Western Canada Sediment ...
... The northern Wuerxun Sag is a lacustrine rift basin which experienced multiple faulting and subsidence during the Lower Cretaceous. The tectonic evolution with uplifted regions as the provenances caused the complex sedimentary fill of the Lower Cretaceous Nantun Formation. In this paper, we use well log, core and 3D seismic data to characterise the sedimentary facies and depositional environment o ...
geophysical logging, etc ; clay fraction; energy; gas hydrate; mineralogy; nuclear magnetic resonance spectroscopy; permeability; porosity; sand; sea level; shale; topographic slope; Alaska; Show all 13 Subjects
Abstract:
... The Hydrate-01 Stratigraphic Test Well was drilled at the Kuparuk 7-11-12 site on the Alaska North Slope in December 2018. Sonic log data provide compressional (P) and shear (S) slowness from which we determine gas hydrate saturation (Sgₕ) estimates using effective medium theory. The sonic Sgₕ estimates compare favorably with Sgₕ estimated from resistivity and nuclear magnetic resonance (NMR) logs ...
logging, etc ; Borneo; bioclimatology; food security; fruiting; fruits; phenology; rain; solar radiation; species diversity; stand structure; sustainable forestry; temperature; trees; tropical forests; wildlife; Show all 16 Subjects
Abstract:
... Timber extraction is often cited as detrimental to wildlife ecology. Little information, however, in particular from the Southeast Asian tropics, is available on how exactly logging affects wildlife food security. To address the gap, this paper presents the first high-resolution comparison of fruit production between logged and intact forests in lowland Borneo. In the period of 2004–2008, dry weig ...
... The standing skyline continues to be a common cable logging configuration. In payload analysis it is usually assumed that the tagline (line connecting the logs to the carriage) length is held constant while yarding a turn up the skyline corridor. We show this assumption severely limits the skyline load-carrying capacity for skylines operating with partial suspension. We suggest that smart carriage ...
... Numerical likelihood-ratio (LR) systems aim to calculate evidential strength for forensic evidence evaluation. Calibration of such LR-systems is essential: one does not want to over- or understate the strength of the evidence. Metrics that measure calibration differ in sensitivity to errors in calibration of such systems. In this paper we compare four calibration metrics by a simulation study base ...