bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Study of Permeability Decline in Tight Formations During Long-Term Depletion
Authors: Cui Q. , Abass H. H. 
Published: April 2016

Abstract
Hydrocarbon production decline behaviors in low permeability reservoirs and conventional reservoirs are significantly different; in such a way that high initial rate is usually observed for a short period in tight formation wells, then the well productivity drops dramatically. The rapid production decline in shale wells has a strong relationship with the loss of rock matrix permeability and reservoir conductivity, resulting from the dissipation of pore pressure during reservoir depletion. This paper presents experimental studies of stress-dependent compaction in tight reservoirs and its impact on long-term recovery.
The magnitude of rock permeability change depends on the in-situ effective stress, which is a combined effect of reservoir pore pressure and confining stress. In this research, permeabilities of a series of shale and sandstone core plugs are measured in the laboratory using pressure transimission test technique. The samples are tested under multiple confining stress and pore pressure combinations. Several confining stress are pre-set to represent different reservoir stress conditions. Different pore pressures are then applied to mimic reservoir depletion process under specific confining stress conditions. The permeability is calculated for all scenarios and pressure dependent permeability behaviors are analyzed for each type of sample.
The interpretations of effective stress dependent permeability show that different types of rocks have different permeability decline signatures responding to the depletion effect. In addition, tight rocks with different dominant porous media (i.e., matrix and fractures) are found to have different permeability behaviors. Characteristics of permeability decline at different pore pressure intervals are analyzed and the critical reservoir pressure and depletion index (i.e., ratio of pore pressure to overburden stress) are identified for different types of rocks where significant permeability change occurs. Based on the stress dependent permeability measurements, the Biot Coefficient is also determined for different tight samples.
Recognizing permeability decline signatures of tight reservoirs provides significant insights into long-term dynamic reservoir conductivity monitoring and contributes to the field management practices. It is indicated from the study that the permeability decline in tight reservoir wells can be significant with continuous depletion while maintaining reservoir pressure above the critical level has the potential to mitigate the sharp production decline in tight formations and therefore enhance ultimate hydrocarbon recovery.
Laplace Domain Coupled Dual Continuum and Embedded Discrete Fracture Model for Rate Transient Analysis in Low Permeability Reservoirs
Authors: Fang Sidong , Cheng Linsong , Huang Shijun , Renyi Cao 
Published: April 2016

Abstract
Modeling transient flow of horizontal wells with complex fracture networks is attractive and challenging topic for economically exploitation of low permeability reservoirs. Previous works have been done by employing analytical, semi-analytical and numerical models to solve this problem. The analytical trilinear-flow is not capable to capture the shapes and distributions of stimulated reservoir volume (SRV), while semi-analytical source function method doesn't consider natural fractures. In the paper, we developed a hybrid coupled approach to combine the embedded-discrete-fracture model (EDFM) and dual continuum representation in Laplace domain. The transient dual porosity with various matrix-block size is implemented to incorporate the fracture spacing and the petro-physical characteristics of flow from tight matrix to natural fractures. Large scale hydraulic fractures are explicitly modeled using embedded-discrete-fracture model (EDFM) as the source terms in the systems. Other than the equivalent distance and finite difference method used in EDFM, a novel element-based numerical method called mixed boundary element method is developed to rigorously capture the transient flow behavior of hydraulic fractured systems and couple the above models in triangle grids. Several examples in this work are presented to show the robustness, applicability and computational convenience of the hybrid approach for the rate transient and pressure transient analysis of low permeability oil and gas reservoirs. The proposed model is validated by comparing the results against both analytical trilinear solutions and other numerical solutions. In addition, the method provides maximum flexibility of representation for complex fracture systems both in pressure transient analysis and production forecast.
Assessment of interobserver agreement and use of selected magnetic resonance imaging variables for differentiation of acute noncompressive nucleus pulposus extrusion and ischemic myelopathy in dogs
Authors: Specchi Swan , Johnson Philippa , Beauchamp Guy , Masseau Isabelle , Pey Pascaline 
Published: April 2016

Abstract
OBJECTIVE To evaluate interobserver agreement for features used in presumptive diagnosis of acute noncompressive nucleus pulposus extrusion (ANNPE) or ischemic myelopathy by MRI, compare findings on postcontrast T1-weighted (T1W) MRI sequences with fat saturation (FS) for the 2 conditions, and determine whether length and directional patterns of hyperintensity of the intramedullary spinal cord on T2-weighted (T2W) fast spin echo (FSE) MRI sequences differ between dogs with these diseases.
DESIGN Retrospective, observational study.
ANIMALS 20 dogs with clinical signs compatible with ANNPE (n = 14) or ischemic myelopathy (6).
PROCEDURES 3 observers evaluated MRI data (including T2W FSE, T2W single-shot FSE, and T1W FS sequences) for dogs with a presumptive diagnosis of ischemic myelopathy or ANNPE. Interobserver agreement for variables of interest including presumptive diagnosis was assessed by κ statistic calculations. Associations between diagnosis and variables of interest were assessed with Fisher exact or Cochran-Mantel-Haenszel tests.
RESULTS Perfect interobserver agreement (κ = 1 for all comparisons) was found for the presumptive diagnosis of ischemic myelopathy versus ANNPE. Meningeal enhancement on postcontrast T1W FS MRI images and nonlongitudinal directional pattern of intramedullary hyperintensity on T2W FSE images were significantly associated with a diagnosis of ANNPE. Greater length of intramedullary hyperintensity was significantly associated with a diagnosis of ischemic myelopathy.
CONCLUSIONS AND CLINICAL RELEVANCE Directional pattern and length of intramedullary hyperintensity on T2W FSE MRI images and enhancement patterns in postcontrast T1W FS sequences may provide important contributions to the criteria currently used in the presumptive diagnosis of ischemic myelopathy versus ANNPE.
Salmonella infection and carriage in reptiles in a zoological collection
Authors: Clancy Meredith M. , Davis Meghan , Valitutto Marc T. , Nelson Kenrad , Sykes John M. 
Published: April 2016

Abstract
OBJECTIVE To identify important subspecies and serovars of Salmonella enterica in a captive reptile population and clinically relevant risk factors for and signs of illness in Salmonella-positive reptiles.
DESIGN Retrospective cross-sectional study.
ANIMALS 11 crocodilians (4 samples), 78 snakes (91 samples), 59 lizards (57 samples), and 34 chelonians (23 samples) at the Bronx Zoo from 2000 through 2012.
PROCEDURES Data pertaining to various types of biological samples obtained from reptiles with positive Salmonella culture results and the reptiles themselves were analyzed to determine period prevalence of and risk factors for various Salmonella-related outcomes.
RESULTS Serovar distribution differences were identified for sample type, reptile phylogenetic family, and reptile origin and health. Salmonella enterica subsp enterica was the most common subspecies in Salmonella cultures (78/175 [45%]), identified across all reptilian taxa. Salmonella enterica subsp diarizonae was also common (42/175 [24%]) and was recovered almost exclusively from snakes (n = 33), many of which had been clinically ill (17). Clinically ill reptiles provided 37% (64) of Salmonella cultures. Factors associated with an increased risk of illness in reptiles with a positive culture result were carnivorous diet and prior confiscation. Snakes had a higher risk of illness than other reptile groups, whereas lizards had a lower risk. Bony changes, dermatitis, and anorexia were the most common clinical signs.
CONCLUSIONS AND CLINICAL RELEVANCE This study provided new information on Salmonella infection or carriage and associated clinical disease in reptiles. Associations identified between serovars or subspecies and reptile groups or clinical disease can guide management of Salmonella-positive captive reptiles.
THE TIME EVOLUTION OF HH 1 FROM FOUR EPOCHS OF HST IMAGES
Authors: Raga A. C. , Reipurth B. , Esquivel A. , Bally J. 
Published: April 2016

ABSTRACT
We present an analysis of four epochs of Hα and [S ii] λλ 6716/6731 Hubble Space Telescope (HST) images of HH 1. For determining proper motions, we explore a new method based on the analysis of spatially degraded images obtained convolving the images with wavelet functions of chosen widths. With this procedure, we are able to generate maps of proper motion velocities along and across the outflow axis, as well as (angularly integrated) proper motion velocity distributions. From the four available epochs, we find the time evolution of the velocities, intensities, and spatial distribution of the line emission. We find that over the last two decades HH 1 shows a clear acceleration. Also, the Hα and [S ii] intensities first dropped and then recovered in the more recent (2014) images. Finally, we show a comparison between the two available HST epochs of [O iii] λ 5007 (1994 and 2014), in which we see a clear drop in the value of the [O iii]/Hα ratio.
LIVING WITH A RED DWARF: ROTATION AND X-RAY AND ULTRAVIOLET PROPERTIES OF THE HALO POPULATION KAPTEYN’S STAR*
Authors: Guinan Edward F. , Engle Scott G. , Durbin Allyn 
Published: April 2016

ABSTRACT
As part of Villanova’s Living with a Red Dwarf program, we have obtained UV, X-ray, and optical data of the Population II red dwarf—Kapteyn’s Star. Kapteyn’s Star is noteworthy for its large proper motions and high radial velocity of ∼+245 km s−1. As the nearest Pop II red dwarf, it serves as an old age anchor for calibrating activity/irradiance–rotation–age relations, and an important test bed for stellar dynamos and the resulting X-ray–UV emissions of slowly rotating, near-fully convective red dwarf stars. Adding to the notoriety, Kapteyn’s Star has recently been reported to host two super-Earth candidates, one of which (Kapteyn b) is orbiting within the habitable zone. However, Robertson et al. questioned the planet’s existence since its orbital period may be an artifact of activity, related to the star’s rotation period. Because of its large Doppler-shift, measures of the important, chromospheric H i Lyα 1215.67 Å emission line can be reliably made, because it is mostly displaced from ISM and geo-coronal sources. Lyα emission dominates the FUV region of cool stars. Our measures can help determine the X-ray–UV effects on planets hosted by Kapteyn’s Star, and planets hosted by other old red dwarfs. Stellar X-ray and Lyα emissions have strong influences on the heating and ionization of upper planetary atmospheres and can (with stellar winds and flares) erode or even eliminate planetary atmospheres. Using our program stars, we have reconstructed the past exposures of Kapteyn’s Star's planets to coronal—chromospheric XUV emissions over time.
INTERRUPTED ERUPTION OF LARGE QUIESCENT FILAMENT ASSOCIATED WITH A HALO CME
Authors: Gosain S. , Filippov Boris , Maurya Ram Ajor , Chandra Ramesh 
Published: April 2016

ABSTRACT
We analyze the observations of an eruptive quiescent filament associated with a halo Coronal Mass Ejection (CME). We use observations from the Atmospheric Imaging Assembly (AIA) instrument onboard the Solar Dynamics Observatory (SDO), Solar and Heliospheric Observatory (SOHO)/Large Angle and Spectrometric Coronagraph (LASCO), and the Solar Terrestrial Relations Observatory (STEREO A/B) satellites. The filament exhibits a slow-rise phase followed by a gradual acceleration and then completely disappears. The filament could be traced in STEREO observations up to an altitude of about 1.44

R

⊙

, where its rise speed reached ∼14 km s−1 and disappeared completely at about 10:32 UT on 2011 October 21. The CME associated with the filament eruption and two bright ribbons in the chromosphere both appeared at about 01:30 UT on October 22, i.e., 15 hr after the filament eruption was seen in He ii 304 Å filtergrams. We show that this delay is abnormally large even if the slow rise speed and slow acceleration of the filament are taken into account. To understand the cause of this delay, we compute the decay index (n) of the overlying coronal magnetic field. The height distribution of the decay index, n, suggests that the zone of instability (

n

>

1) at a lower altitude, 144–480 Mm, is followed by a zone of stability (

n

<

1) between 540 and 660 Mm. We interpret the observed delay to be due to the presence of the latter zone, i.e., the zone of stability, which could provide a second quasi-equilibrium state to the filament until it finally erupts.
THE RADIO–GAMMA CORRELATION IN STARBURST GALAXIES
Authors: Eichmann B. , Tjus J. Becker 
Published: April 2016

ABSTRACT
We present a systematic study of non-thermal electron–proton plasma and its emission processes in starburst galaxies in order to explain the correlation between the luminosity in the radio band and the recently observed gamma luminosity. In doing so, a steady state description of the cosmic-ray (CR) electrons and protons within the spatially homogeneous starburst is considered where continuous momentum losses are included as well as catastrophic losses due to diffusion and advection. The primary source of the relativistic CRs, e.g., supernova remnants, provides a quasi-neutral plasma with a power-law spectrum in momentum where we account for rigidity-dependent differences between the electron and proton spectrum. We examine the resulting leptonic and hadronic radiation processes by synchrotron radiation, inverse Compton scattering, Bremsstrahlung, and hadronic pion production. Finally, the observations of NGC 253, M82, NGC 4945, and NGC 1068 in the radio and gamma-ray bands as well as the observed supernova rate are used to constrain a best-fit model. In the case of NGC 253, M82, and NGC 4945 our model is able to accurately describe the data, showing that: (i) supernovae are the dominant particle accelerators for NGC 253, M82, and NGC 4945, but not for NGC 1068; (ii) all considered starburst galaxies are poor proton calorimeters in which for NGC 253 the escape is predominantly driven by the galactic wind, whereas the diffusive escape dominates in NGC 4945 and M82 (at energies >1 TeV); and (iii) secondary electrons from hadronic pion production are important to model the radio flux, but the associated neutrino flux is below the current observation limit.
SUPERMASSIVE BLACK HOLES AND THEIR HOST SPHEROIDS. III. THE MBH–nsph CORRELATION
Authors: Savorgnan Giulia A. D. 
Published: April 2016

ABSTRACT
The Sérsic

R

1

/

n

model is the best approximation known to date for describing the light distribution of stellar spheroidal and disk components, with the Sérsic index n providing a direct measure of the central radial concentration of stars. The Sérsic index of a galaxy’s spheroidal component, n
sph, has been shown to tightly correlate with the mass of the central supermassive black hole, M
BH. The

M

BH

–

n

sph

correlation is also expected from other two well known scaling relations involving the spheroid luminosity, L
sph: the

L

sph

–

n

sph

and the

M

BH

–

L

sph

. Obtaining an accurate estimate of the spheroid Sérsic index requires a careful modeling of a galaxy’s light distribution and some studies have failed to recover a statistically significant

M

BH

–

n

sph

correlation. With the aim of re-investigating the

M

BH

–

n

sph

and other black hole mass scaling relations, we performed a detailed (i.e., bulge, disks, bars, spiral arms, rings, halo, nucleus, etc.) decomposition of 66 galaxies, with directly measured black hole masses, that had been imaged at 3.6 μm with Spitzer. In this paper, the third of this series, we present an analysis of the

L

sph

–

n

sph

and

M

BH

–

n

sph

diagrams. While early-type (elliptical+lenticular) and late-type (spiral) galaxies split into two separate relations in the

L

sph

–

n

sph

and

M

BH

–

L

sph

diagrams, they reunite into a single

M

BH

∝

n

sph

3.39
±
0.15

sequence with relatively small intrinsic scatter (

ϵ
≃
0.25

dex

). The black hole mass appears to be closely related to the spheroid central concentration of stars, which mirrors the inner gradient of the spheroid gravitational potential.
La visite de Guillaume II à Strasbourg en août 1908
Authors: Uberfill François 
Published: April 2016

Guillaume II multiplie les voyages et séjours en Alsace. Ceux-ci se déroulent au milieu d’un déploiement de faste et de démonstrations militaires imposants. La visite de Guillaume II en mai 1908, à l’occasion du vingtième anniversaire de son accession au trône, surpasse toutes les autres par la décoration de la ville transformée en village Potemkine et la mise en scène de la personne de l’empereur et de la famille impériale. Guillaume II apparaît comme le digne successeur du fondateur du Reich, le valeureux chef d’une armée puissante, mais aussi comme le Père de la Patrie qui veille sur une province qui lui est chère. La fête donnée en son honneur se déroule à la fois sur la place impériale, tout le long des artères traversées par les cortèges et sur le champ de parade du Polygone. Le maire Schwander, soucieux de faire aussi bien que ses collègues Oberbürgermeister des autres États, a voulu associer la population à l’hommage rendu au Kaiser. Il a mobilisé près de deux cents associations pour former des haies d’honneur le long du parcours. Mais une bonne partie des Strasbourgeois reste sur sa réserve.
The detection of carbon dioxide leaks using quasi-tomographic laser absorption spectroscopy measurements in variable wind
Authors: Levine Zachary H. , Pintar Adam L. , Dobler Jeremy T. , Blume Nathan , Braun Michael , Zaccheo T. Scott , Pernini Timothy G. 
Published: April 2016

Abstract. Laser absorption spectroscopy (LAS) has been used over the last several decades for the measurement of trace gasses in the atmosphere. For over a decade, LAS measurements from multiple sources and tens of retroreflectors have been combined with sparse-sample tomography methods to estimate the 2-D distribution of trace gas concentrations and underlying fluxes from point-like sources. In this work, we consider the ability of such a system to detect and estimate the position and rate of a single point leak which may arise as a failure mode for carbon dioxide storage. The leak is assumed to be at a constant rate giving rise to a plume with a concentration and distribution that depend on the wind velocity. We demonstrate the ability of our approach to detect a leak using numerical simulation and also present a preliminary measurement.
Characterizing the thermal ablation of cells for silicon biosensors
Authors: Leahy Stephane , Banavali Amey , Kong Wei , Lai Yongjun 
Published: April 2016

Being able to restore the surface of biosensors to their initial material-free state after immobilization of the biological target can facilitate biosensor development and reduce measurement costs. Thermal ablation has been recently proposed as a new method to conveniently accomplish this using high temperature heating with a hot plate. Key variables related to chip heating are characterized to optimize the effectiveness of thermal ablation. Testing was performed using Poly-L- Lysine-functionalized silicon-on-insulator chips and E. coli. An analysis based on image processing demonstrates that the maximum temperature reached by the chip and the length of time the chip is held at the maximum temperature significantly affect cell removal, while the heat rate at which the chip goes from room temperature to the maximum temperature does not affect cell removal. It was found that nearly all cells can be removed by heating the chip at 425°C for 10 s or by heating the chip at 375°C for 100 s.
The Performance & Flow Visualization Studies of Three dimensional (3-D) Wind Turbine Blade Models
Authors: . Sutrisno , . Prajitno , . Purnomo , Setyawan B.W. 
Published: April 2016

<p>The researches on the design of 3-D wind turbine blades have been received less attention so far even though 3-D blade products are widely sold. In the opposite, advanced researches in 3-D helicopter blade have been studied rigorously. Researches in wind turbine blade modeling are mostly assumed that blade span wise sections behaves as independent two dimensional (2-D) airfoils, implying that there is no exchange of momentum in the span wise direction. Further more flow visualization experiments are infrequently conducted.</p><p>The purpose of this study is to investigate the performance of 3-D wind turbine blade models with backward-forward swept and verify the flow patterns using flow visualization. In this research, the blade models are constructed based on the twist and chord distributions following Schmitz’s formula. Forward and backward swept are added to the wind turbine blades. It is hoped that the additional swept would enhance or diminish outward flow disturbance or stall development propagation on the span wise blade surfaces to give better blade design.</p><p>The performance of the 3-D wind turbine system models are measured by a torque meter, employing Prony’s braking system, and the 3-D flow patterns around the rotating blade models are investigated applying “tuft-visualization technique”, to study the appearance of laminar, separated and boundary layer flow patterns surrounding the 3-dimentional blade system.</p>For low speed wind turbines, Dumitrescu and Cardos (2011) have identified that stall spreads from the root of the rotating blade. In this study, it is found that for blades with (i) forward swept tip and backward swept root, the initial stall at the blade bottom would be amplified by concurrent strengthening flow due to the backward swept root to create strong stall spreading outward, and therefore the blades gives lower performance. For blades with (ii) backward swept tip and forward swept root, the initial stall at the blade bottom would be weakened by opposite weakening flow due to the forward swept root, generate weak stall that tend to deteriorate. These blades have better performance.
On Experiments in Empirical Legal Research
Authors: van den Bos Kees , Hulst Liesbeth 
Published: April 2016

On Experiments in Empirical Legal Research
The current paper presents some observations on experiments in empirical legal research. The paper notes some strengths and weakness of the experimental method. The paper distinguishes between experiments run in controlled laboratory settings and experiments conducted in field settings and notes the different goals the different types of experiments generally have. The paper identifies important stumbling blocks that legal researchers who are new to setting up experiments may face and proposes that focusing the research in a constructive and independent way is important to overcome these problems. The necessity of running multiple studies to overcome other problems are discussed as well. When conducted in this way, experiments may serve an important role in the field of empirical legal studies and may help to further explore the exciting issues of law, society, and human behavior.
MARTON, Scarlett (ed.): Nietzsche em chave hispânica, São Paulo, Edições Loyola, 2015.
Authors: Lavernia Biescas Kilian 
Published: April 2016

Reseña del libro MARTON, Scarlett (ed.): Nietzsche em chave hispânica, São Paulo, Edições Loyola, 2015.