scholarly journals Biofuel Emulsifier Using High-Velocity Impinging Flows and Singularities in Microchannels

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
A. Belkadi ◽  
A. Montillet ◽  
J. Bellettre
Keyword(s):  
Internal Combustion Engines ◽  
Continuous Phase ◽  
Point Of View ◽  
General Point ◽  
Lipid Phase ◽  
Water Droplets ◽  
Water Fraction ◽  
Microfluidic Mixer ◽  
Low Viscosity ◽  
Rayleigh Instabilities

The objective of this experimental work is to design an original microfluidic mixer for continuous emulsification of small fractions of water in a lipid phase. This system is aimed to be integrated on-line in the process so as to avoid the use of a surfactant. The currently targeted application is a better combustion of water-supplemented alternative biofuels in boilers, turbines, or internal combustion engines in general. Therefore, mean size of droplets of water in the emulsion should be 5–10 μm, and the water content should not exceed ∼20%. Microsystems developed in this work are designed so as to enhance different flow perturbations that are favorable for the emulsification process. The microchannels for the fluids admittance have different sections: 300 × 300 μm2 and 600 × 600 μm2. As a consequence, an impinging flow is developed at the crossing of the inlet microchannels of the two phases which has for effect a significant stretching of the fluids. Then, depending on the continuous phase, Rayleigh instabilities can be developed in the straight parts of the outlet channels (600 × 600 μm2) and/or the enhancement of fluid splitting is obtained; thanks to a singularity (bend) located in the same outlet channels. Two different continuous phases are tested (gasoil and sun flower oil) for which the flow rate is about (65–100 ml/min). The water fraction is varied in the range 7–24%. It is shown that the length of the outlet microchannels is a crucial parameter. Considering an oil phase with low viscosity, such as gasoil, a too long channel can promote coalescence. On the opposite, longer outlet channels are needed with more viscous fluids (like sunflower oil) in order to develop Rayleigh instabilities which is, in this case, the more efficient way to obtain emulsions in this kind of microsystem. On a general point of view, concerning the size of the water droplets, dispersion of water is much more efficient with this microsystem using gasoil rather than vegetable oil as the continuous phase. Considering the targeted application, emulsions with an average size of water droplets of about 10 μm were obtained with gasoil as the continuous phase.

scholarly journals Biofuel Emulsifier Using High Velocity Impinging Flows and Singularities in Micro-Channels

2016 ◽  
Author(s):  
A. Belkadi ◽  
A. Montillet ◽  
J. Bellettre
Keyword(s):  
Surface Tension ◽  
Internal Combustion Engines ◽  
Continuous Phase ◽  
Lipid Phase ◽  
Combustion Engines ◽  
Microfluidic Mixer ◽  
Micro Channels ◽  
On Line ◽  
Density Surface ◽  
Impinging Flows

The objective of this work is to design an original microfluidic mixer for continuous emulsification of small fractions of water in a lipid phase. This system is aimed to be integrated on-line in the process so as to avoid the use of a surfactant. The targeted application is a better combustion of alternative biofuels in boilers, turbines or internal combustion engines in general. The developed micro-system which includes impinging flows and elbows, is performed on the basis of a specific design of micro-channels, adapted to the respective flow rates and the characteristics of the fluids to be emulsified (viscosity, surface tension). The variation of different parameters is tested in this study such as the nature of the lipid phase (viscosity, density, surface tension and components), the length of micro-channels in the elbow and the flow rate of the dispersed phase. The dispersion of water is much more efficient with this microsystem using gasoil rather than vegetable oil as the continuous phase.

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 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.

Computationally Efficient Simulation of Multi-Component Fuel Combustion Using a Sparse Analytical Jacobian Chemistry Solver and High-Dimensional Clustering

2013 ◽  
Author(s):  
Federico Perini ◽  
Anand Krishnasamy ◽  
Youngchul Ra ◽  
Rolf D. Reitz
Keyword(s):  
Reaction Mechanism ◽  
Chemical Kinetics ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Engine Performance ◽  
Internal Combustion ◽  
Point Of View ◽  
High Dimensional ◽  
Computational Point ◽  
Fuel Surrogates

The need for more efficient and environmentally sustainable internal combustion engines is driving research towards the need to consider more realistic models for both fuel physics and chemistry. As far as compression ignition engines are concerned, phenomenological or lumped fuel models are unreliable to capture spray and combustion strategies outside of their validation domains — typically, high-pressure injection and high-temperature combustion. Furthermore, the development of variable-reactivity combustion strategies also creates the need to model comprehensively different hydrocarbon families even in single fuel surrogates. From the computational point of view, challenges to achieving practical simulation times arise from the dimensions of the reaction mechanism, that can be of hundreds species even if hydrocarbon families are lumped into representative compounds, and thus modeled with non-elementary, skeletal reaction pathways. In this case, it is also impossible to pursue further mechanism reductions to lower dimensions. CPU times for integrating chemical kinetics in internal combustion engine simulations ultimately scale with the number of cells in the grid, and with the cube number of species in the reaction mechanism. In the present work, two approaches to reduce the demands of engine simulations with detailed chemistry are presented. The first one addresses the demands due to the solution of the chemistry ODE system, and features the adoption of SpeedCHEM, a newly developed chemistry package that solves chemical kinetics using sparse analytical Jacobians. The second one aims to reduce the number of chemistry calculations by binning the CFD cells of the engine grid into a subset of clusters, where chemistry is solved and then mapped back to the original domain. In particular, a high-dimensional representation of the chemical state space is adopted for keeping track of the different fuel components, and a newly developed bounding-box-constrained k-means algorithm is used to subdivide the cells into reactively homogeneous clusters. The approaches have been tested on a number of simulations featuring multi-component diesel fuel surrogates, and different engine grids. The results show that significant CPU time reductions, of about one order of magnitude, can be achieved without loss of accuracy in both engine performance and emissions predictions, prompting for their applicability to more refined or full-sized engine grids.

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.

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.

scholarly journals Cancer metabolic subtypes and their association with molecular and clinical features

2021 ◽  
Author(s):  
Enrico Moiso ◽  
Paolo Provero
Keyword(s):  
Clinical Data ◽  
Large Scale ◽  
Tumor Grade ◽  
Point Of View ◽  
General Point ◽  
Protein Abundance ◽  
Phenotypic Data ◽  
Cancer Subtypes ◽  
Molecular Features

Alteration of metabolic pathways in cancer has been investigated for many years, beginning way before the discovery of the role of oncogenes and tumor suppressors, and the last few years have witnessed a renewed interest in this topic. Large-scale molecular and clinical data on tens of thousands of samples allow us today to tackle the problem from a general point of view. Here we show that trancriptomic profiles of tumors can be exploited to define metabolic cancer subtypes, that can be systematically investigated for association with other molecular and clinical data. We find thousands of significant associations between metabolic subtypes and molecular features such as somatic mutations, structural variants, epigenetic modifications, protein abundance and activation; and with clinical/phenotypic data including survival probability, tumor grade, and histological types. Our work provides a methodological framework and a rich database of statistical associations, accessible from https://metaminer.unito.it, that will contribute to the understanding of the role of metabolic alterations in cancer and to the development of precision therapeutic strategies.

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