scholarly journals Two-Phase Flow Effects on Seismic Wave Anelasticity in Anisotropic Poroelastic Media

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6528
Author(s):  
Juan Santos ◽  
José Carcione ◽  
Jing Ba
Keyword(s):  
Transversely Isotropic ◽  
Immiscible Fluids ◽  
Point Of View ◽  
General Point ◽  
Spatial Period ◽  
Two Phase ◽  
Porous Layers ◽  
Poroelastic Media ◽  
Flow Effects ◽  
Flow Interference

We study the wave anelasticity (attenuation and velocity dispersion) of a periodic set of three flat porous layers saturated by two immiscible fluids. The fluids are very dissimilar in properties, namely gas, oil, and water, and, at most, three layers are required to study the problem from a general point of view. The sequence behaves as viscoelastic and transversely isotropic (VTI) at wavelengths much longer than the spatial period. Wave propagation causes fluid flow and slow P modes, inducing anelasticity. The fluids are characterized by capillary forces and relative permeabilities, which allow for the existence of two slow modes and the presence of dissipation, respectively. The methodology to study the physics is based on a finite-element uspcaling approach to compute the complex and frequency-dependent stiffnesses of the effective VTI medium. The results of the experiments indicate that there is higher dissipation and anisotropy compared to the widely used model based on an effective fluid that ignores the effects of surface tension (capillarity) and viscous flow interference between the two fluid phases.

scholarly journals Mesh filtration problems with a two-flow structure of phase velocities

2021 ◽  
Vol 2099 (1) ◽  
pp. 012006
Author(s):  
M Ivanov ◽  
I Kremer ◽  
Yu Laevsky
Keyword(s):  
Porous Medium ◽  
Conservation Laws ◽  
Flow Structure ◽  
Integral Form ◽  
Point Of View ◽  
General Point ◽  
Two Phase ◽  
Mesh Structure ◽  
Phase Velocities ◽  
Gravitational Segregation

Abstract This paper deals with the problem of filtration of a two-phase incompressible fluid within the Buckley-Leverett model. From a general point of view, a two-flow structure of conservation laws is investigated. In addition, since the solution in the Buckley-Leverett model is discontinuous, conservation laws are presented in the generalized integral form. A good illustration of the approach presented is the problem of gravitational segregation of oil and water in a porous medium. For this problem, a two-flow mesh structure of conservation laws is described.

scholarly journals Lessons from the COVID-19 Pandemic on the Use of Artificial Intelligence in Digital Radiology: The Submission of a Survey to Investigate the Opinion of Insiders

Healthcare ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 331
Author(s):  
Daniele Giansanti ◽  
Ivano Rossi ◽  
Lisa Monoscalco
Keyword(s):  
Artificial Intelligence ◽  
General Purpose ◽  
Point Of View ◽  
General Point ◽  
Thoracic Radiography ◽  
Digital Radiology ◽  
Electronic Survey ◽  
Radiology Technicians ◽  
Medical Radiology ◽  
Great Development

The development of artificial intelligence (AI) during the COVID-19 pandemic is there for all to see, and has undoubtedly mainly concerned the activities of digital radiology. Nevertheless, the strong perception in the research and clinical application environment is that AI in radiology is like a hammer in search of a nail. Notable developments and opportunities do not seem to be combined, now, in the time of the COVID-19 pandemic, with a stable, effective, and concrete use in clinical routine; the use of AI often seems limited to use in research applications. This study considers the future perceived integration of AI with digital radiology after the COVID-19 pandemic and proposes a methodology that, by means of a wide interaction of the involved actors, allows a positioning exercise for acceptance evaluation using a general purpose electronic survey. The methodology was tested on a first category of professionals, the medical radiology technicians (MRT), and allowed to (i) collect their impressions on the issue in a structured way, and (ii) collect their suggestions and their comments in order to create a specific tool for this professional figure to be used in scientific societies. This study is useful for the stakeholders in the field, and yielded several noteworthy observations, among them (iii) the perception of great development in thoracic radiography and CT, but a loss of opportunity in integration with non-radiological technologies; (iv) the belief that it is appropriate to invest in training and infrastructure dedicated to AI; and (v) the widespread idea that AI can become a strong complementary tool to human activity. From a general point of view, the study is a clear invitation to face the last yard of AI in digital radiology, a last yard that depends a lot on the opinion and the ability to accept these technologies by the operators of digital radiology.

Changes in the Prognosis of Functional Psychoses Since the Days of Kraepelin

1967 ◽  
Vol 113 (501) ◽  
pp. 813-822 ◽  
Author(s):  
Örnulv Ödegård
Keyword(s):  
Special Problem ◽  
Point Of View ◽  
General Point ◽  
Course Of Illness ◽  
Dynamic Reasoning ◽  
Starting Point ◽  
Functional Psychoses ◽  
External Conditions ◽  
Point Of Departure ◽  
The Universe

My choice of Kraepelin as a point of departure for this lecture has definite reasons. If one wants to stay within the field of clinical psychiatry (as opposed to psychiatric history), that is as far back as one can reasonably go. By this no slight is intended upon the pre-Kraepelinian psychiatrists. For our topic Henry Maudsley would indeed have been a most appropriate starting point, and by no means for reasons of courtesy. His general point of view is admirably sound as a basis for the scientific study of prognosis in psychiatry. I quote: “There is no accident in madness. Causality, not casualty, governs its appearance in the universe, and it is very far from being a good and sufficient practice simply to mark its phenomena and straightway to pass on as if they belonged not to an order but to a disorder of events that called for no explanation.” On the special problem of prognosis he shows his clinical acumen by stating that the outlook is poor when the course of illness is insidious, but this only means that these cases develop their psychoses on the basis of mental deviations which go very far back in the patient's life, so that in fact they are generally in a chronic stage at the time of their first admission to hospital. Here he actually corrects a mistake which is still quite often made. He shows his dynamic attitude when he says that prognosis is to a large extent modified by external conditions, in particular by the attitude of friends and relatives. Maudsley's dynamic reasoning was limited by the narrow framework of the degeneration hypothesis of those days. He had a sceptical attitude towards classification, which he regarded as artificial and dangerously pseudo-exact. His own classification was deliberately provisional, with very wide groups. He held that a description of various sub-forms of chronic insanity was useless, as it would mean nothing but a tiresome enumeration of unconnected details.

scholarly journals Body waves in poroelastic media saturated by two immiscible fluids

1996 ◽  
Vol 101 (B11) ◽  
pp. 25149-25159 ◽  
Author(s):  
Kagan Tuncay ◽  
M. Yavuz Corapcioglu
Keyword(s):  
Immiscible Fluids ◽  
Body Waves ◽  
Poroelastic Media

scholarly journals I.—The Metamorphosis of the Lizard Gabbros

1886 ◽  
Vol 3 (11) ◽  
pp. 481-489 ◽  
Author(s):  
J. J. H. Teall
Keyword(s):  
Mechanical Energy ◽  
Earth Pressure ◽  
Careful Consideration ◽  
Point Of View ◽  
Igneous Rocks ◽  
General Point ◽  
Present Moment ◽  
General View ◽  
Original Rock ◽  
The Subject

If we take a general view of the present position of geological science, we are struck by the fact that, although there is substantial agreement amongst geologists on matters relating to the origin of the rocks usually designated as aqueous and igneous, the greatest diversity of opinion prevails with regard to the circumstances under which the so-called metamorphic rocks have been produced. Every fragment of evidence calculated to throw light on the origin of these rocks, therefore, deserves the most careful consideration. Of recent years special attention has been directed to the effects of mechanical energy in modifying the mineralogical and structural characters of rocks originally formed by aqueous and igneous agencies; and a suspicion has been aroused that it is in this direction that we must look for a solution of many of the problems connected with the origin of the crystalline schists. A visit to the Lizard Peninsula of Cornwall during the present summer has convinced me of the immense importance of this view so far as that district is concerned. That portion of the peninsula which lies south of a line drawn from Porthalla on the east to Polurrian Cove on the west is formed.partly of igneous rocks—such as gabbro, greenstone, serpentine, and granite—and partly of crystalline schists. The igneous rocks, in certain places, become foliated and sohistose and sometimes show a definite banding due to a variation in the relative proportions of the different constituents. In other words they present characters which are usually regarded as distinctive of the crystalline schists. There is, moreover, evidence to show that these characters are mainly the result of a yielding to earth-pressure subsequent to the consolidation of the original rock. At the present moment, having just returned from the district, I am unable to treat the subject from a general point of view with any prospect of success; but it has occurred to me that some details with regard to one of the rocks may not be without interest to members of the Association.

scholarly journals Local Participation in Tourism Development—Roles of Non-Tourism Related Residents of the Alpine Destination Bad Reichenhall

2019 ◽  
Vol 11 (24) ◽  
pp. 6947 ◽  
Author(s):  
Markus Kantsperger ◽  
Hannes Thees ◽  
Christian Eckert
Keyword(s):  
Developing Countries ◽  
Content Analysis ◽  
Qualitative Content Analysis ◽  
Stakeholder Participation ◽  
Qualitative Interviews ◽  
Tourism Development ◽  
Point Of View ◽  
General Point ◽  
Local Participation ◽  
Important Target

This study applies an adapted approach of the traditional view on local participation in tourism development. First, the study mainly focuses on exploring the patterns behind participation instead of the reasons for participation. Second, a case is chosen that transcends the interest in researching participation in developing countries. Third, the study focuses on non-tourism related residents, an under-researched group of stakeholders. It is thus investigated how non-tourism related residents face the process of participation in tourism development and what the main barriers and drivers are in this regard. To discuss this issue, the study takes a closer look at the case of Bad Reichenhall, an Alpine Destination in Germany. 15 qualitative interviews are conducted with non-tourism related residents and further evaluated through a qualitative content analysis. The results underline that tourism represents a public domain that concerns all stakeholders of a destination. The typology derived throughout the study reflects the heterogeneity of non-tourism related residents, coming up with four types of non-tourism related residents facing participation in tourism development rather differently. Various barriers and drivers are revealed that impact non-tourism related residents from both a personal and general point of view. Non-tourism related residents turn out as a promising and important target group in the discourse of stakeholder participation in tourism development.

Experimental Investigation on Droplet Behavior in a Transonic Compressor Cascade

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Niklas Neupert ◽  
Birger Ober ◽  
Franz Joos
Keyword(s):  
Experimental Investigation ◽  
Gas Turbines ◽  
Surface Film ◽  
Flow Channel ◽  
Point Of View ◽  
Compressor Cascade ◽  
Two Phase ◽  
Transonic Compressor ◽  
Droplet Behavior ◽  
Industrial Gas Turbines

In recent years, overspray fogging has become a powerful means for power augmentation of industrial gas turbines (GT). Most of the studies concerning this topic focus on the problem from a thermodynamic point of view. Only a few studies, however, were undertaken to investigate the droplet behavior in the flow channel of a compressor. In this paper, results of experimental investigation of a water laden flow through a transonic compressor cascade are presented. A finely dispersed spray was used in the measurements (D10 < 10 μm). Results of the droplet behavior are shown in terms of shadowgraphy images and images of the blade surface film pattern. The angle of attack, the incoming velocity, and the water load were varied. The qualitative observations are related to laser Doppler and phase Doppler anemometer (LDA/PDA) data taken in the flow channel and at the outlet of the cascade. The data represent a base for numerical and mean line models of two-phase compressor flow.

scholarly journals El papel de la educación en la filosofía moral de David Hume / The role of education in Hume's moral philosophy

2017 ◽  
Vol 20 (30) ◽  
pp. 17-37
Author(s):  
Santiago Álvarez García
Keyword(s):  
Moral Philosophy ◽  
David Hume ◽  
Point Of View ◽  
General Point

El presente artículo muestra cómo la crítica humeana a los fundamentos del racionalismo moral y a sus consecuencias en el terreno de las ideas educativas propició un cambio significativo en la comprensión de los objetivos de la educación moral que pasaron de buscar el perfeccionamiento de la agencia, a perseguir la perfección y el refinamiento de las capacidades del individuo como espectador y evaluador moral imparcial. Esta trasformación de la finalidad y del currículo de la educación moral será la solución que Hume ofrezca a los problemas de parcialidad derivados de la historicidad y la caducidad del general point of view como criterio último para el juicio moral. La exposición constante del educando a todas las formas históricas de la belleza, junto con la poesía, la literatura, el estudio de la historia y la filosofía, constituirán para Hume la base de esta revolución pedagógica.

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