scholarly journals A bottom-up approach to construct or deconstruct a fluid instability

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Darío M. Escala ◽  
Alberto P. Muñuzuri
Keyword(s):  
Relative Displacement ◽  
Industrial Applications ◽  
Two Fluids ◽  
Road Map ◽  
Fluid Instability ◽  
Fluid Instabilities ◽  
Fingering Instability ◽  
Long Time ◽  
The Subject ◽  
At Will

AbstractFluid instabilities have been the subject of study for a long time. Despite all the extensive knowledge, they still constitute a serious challenge for many industrial applications. Here, we experimentally consider an interface between two fluids with different viscosities and analyze their relative displacement. We designed the contents of each fluid in such a way that a chemical reaction takes place at the interface and use this reaction to suppress or induce a fingering instability at will. This process describes a road map to control viscous fingering instabilities in more complex systems via interfacial chemical reactions.

scholarly journals Dispersions in porous beds

2004 ◽  
Vol 58 (2) ◽  
pp. 49-54 ◽  
Author(s):  
Radmila Secerov-Sokolovic ◽  
Slobodan Sokolovic
Keyword(s):  
Porous Media ◽  
Porous Matrix ◽  
Continuous Phase ◽  
Industrial Applications ◽  
Mathematical Functions ◽  
Solid Interface ◽  
Current State ◽  
Long Time ◽  
The Subject ◽  
New Applications

Dispersions and porous media exist either in nature or in industrial applications. They have been the subject of investigations for a long time, but the complexity of the phenomenon is the major obstacle to its better understanding. Many factors influence the interface interactions, transport, accumulation and detachment of particles in a porous matrix limiting new applications. The current state of investigations which include dispersions in the liquid continuous phase, especially emulsions, liquid/solid interface interactions in porous media and some new mathematical functions were reviewed in this paper.

An Adaptive and Learning System for Feedback-Controlled Evoked Response Studies

1981 ◽  
Vol 20 (03) ◽  
pp. 169-173
Author(s):  
J. Wagner ◽  
G. Pfurtscheixer
Keyword(s):  
Brain Activity ◽  
Evoked Response ◽  
Learning System ◽  
Time Interval ◽  
Electrical Brain Activity ◽  
Long Time ◽  
The Subject ◽  
Eeg Power ◽  
Stimulation System ◽  
Background Eeg

The shape, latency and amplitude of changes in electrical brain activity related to a stimulus (Evoked Potential) depend both on the stimulus parameters and on the background EEG at the time of stimulation. An adaptive, learnable stimulation system is introduced, whereby the subject is stimulated (e.g. with light), whenever the EEG power is subthreshold and minimal. Additionally, the system is conceived in such a way that a certain number of stimuli could be given within a particular time interval. Related to this time criterion, the threshold specific for each subject is calculated at the beginning of the experiment (preprocessing) and adapted to the EEG power during the processing mode because of long-time fluctuations and trends in the EEG. The process of adaptation is directed by a table which contains the necessary correction numbers for the threshold. Experiences of the stimulation system are reflected in an automatic correction of this table. Because the corrected and improved table is stored after each experiment and is used as the starting table for the next experiment, the system >learns<. The system introduced here can be used both for evoked response studies and for alpha-feedback experiments.

The Phantom Defense: America's Pursuit of the Star Wars Illusion. By Craig Eisendrath, Melvin A. Goodman, and Gerald E. Marsh. Westport, CT: Praeger, 2001. 216p. $24.95. Ballistic Missile Defense and the Future of American Security: Agendas, Perceptions, Technology, and Policy. By Roger Handberg. Praeger, 2001. 264p. $62.00. Rockets' Red Glare: Missile Defenses and the Future of World Politics. Edited by James J. Wirtz and Jeffrey A. Larsen. Boulder, CO: Westview, 2001. 368p. $28.50.

2002 ◽  
Vol 96 (4) ◽  
pp. 879-880
Author(s):  
David Goldfischer
Keyword(s):  
World Politics ◽  
Ballistic Missile ◽  
Missile Defense ◽  
Star Wars ◽  
Technological Context ◽  
The Future ◽  
Ballistic Missile Defense ◽  
Long Time ◽  
Strategic Defense ◽  
The Subject

As Michael O'Hanlon concludes in his excellent contribution to Rockets' Red Glare: “We should…get used to the debate over ballistic missile defenses. It has been around a long time, and no final resolution is imminent” (p. 132). In one sense, a review of these three recent books makes clear that many analysts had grown a bit too used to positioning themselves in terms of the 1972 ABM Treaty. Preoccupied with arguments over whether the treaty should be preserved, modified, or rewritten in light of a changing strategic and technological context, no one seemed to have anticipated that President George W. Bush would simply withdraw from it, invoking Article XV's provision that either party could withdraw if “extraordinary events related to the subject matter of this Treaty have jeopardized its supreme interests.” Even many strategic defense supporters who deemed the treaty obsolete (as Robert Joseph persuasively maintains in his contribution to Rockets' Red Glare) generally believed that it should only—and would only—be scrapped if negotiations over U.S.-proposed changes broke down. (“The Bush Administration,” surmises O'Hanlon, “will surely try very hard to amend it before going to such an extreme”) (p. 112). In the event, the president's team disavowed even the word “negotiation,” saying they were willing only to “consult” the Russians regarding the treaty's impending demise.

Effects of slide-to-roll ratio and varying velocity on the lubrication performance of grease at low speed

2021 ◽  
pp. 135065012199336
Author(s):  
Yiming Han ◽  
Jing Wang ◽  
Xuyang Jin ◽  
Shanshan Wang ◽  
Rui Zhang
Keyword(s):  
Steady State ◽  
Critical Speed ◽  
Industrial Applications ◽  
Transient Effects ◽  
Disintegration Time ◽  
Low Speed ◽  
Existence Time ◽  
Pure Rolling ◽  
Lubrication Performance ◽  
Long Time

Under steady-state pure rolling conditions with low speed, the thickener fiber agglomerations can be maintained for a long time, generating a beneficial thicker film thickness. However, in industrial applications, motions with sliding or transient effects are very common for gears, rolling-element bearings or even chain drives, evaluation of the grease performance under such conditions is vital for determining the lubrication mechanism and designing new greases. In this project, optical interferometry experiments were carried out on a ball-disk test rig to study the disintegration time of the grease thickener agglomerations with the increase of the slide-to-roll ratio under steady-state and reciprocation motions. Under steady-state conditions, the thickener fiber agglomeration can exist for a while and the time becomes shorter with the increase of the slide-to-roll ratio above the critical speed. Below the critical speed, the thickener fiber can exist in the contact in the form of a quite thick film for a very long time under pure rolling conditions but that time is decreased with the increase of the slide-to-roll ratio. The introduction of the transient effect can further reduce the existence time of the thickener.

How Far Scientific is Snakebite Prevention and First Aid Treatment in School Textbook?

2019 ◽  
Vol 31 (1) ◽  
pp. 39-40
Author(s):  
Faiha Fairouz ◽  
Rumana Rashid ◽  
Abdullah Abu Sayeed
Keyword(s):  
Health Problem ◽  
Rural Areas ◽  
Elementary Science ◽  
First Aid ◽  
Primary Treatment ◽  
National Guidelines ◽  
Long Time ◽  
Class Viii ◽  
The Subject ◽  
School Books

Background: Snakebite is an old health problem in rural areas. In Bangladesh, the snakebite issue is included in school syllabus, in curriculum since long time, so that people can take/get immediate first aid treatment and can prevent snakebite. The success of snakebite treatment depends more on providing first aid treatment immediately after snakebite by learning and by sending the patients quickly to hospital. Snakebite is a preventable health problem indeed. If it can be prevented the rate of snakebite will also decrease. In the recently published snake bite management Guideline by WHO it has been targeted to reduce 50% of mortality & disability due to snakebite by 2030.1 Methods: a. The snakebite topic or issue has been thoroughly reviewed in the secondary and higher secondary school books. b. National Guidelines on snakebite in providing/ giving first aid treatment has been reviewed.2 c. The correlation between the topic to learn the subject and the national guidelines have been reviewed and given taken into account. d. The similarity or correlation between the national guidelines and the topic in the prevention of snakebite in the book have been observed & reviewed. It was a descriptive/narrative research study. Results: In the book of class IV in Primary and Secondary level students, ‘Elementary Science, (‘Prathomiik Bigghan’) page no. 86 and in book of class VIII Home Science (‘Gharjhastha Biggan’) page no. 16 the Snakebite issue/topic is mentioned.2,3 There are 22 information on the first aid/primary treatment of Snakebite among which 5 (five) are nonscientific rather harmful. (Table & Picture) Bangladesh J Medicine Jan 2020; 31(1) : 39-40

Latins and Greeks in Debate over Purgatory, 1230–1439

1984 ◽  
Vol 35 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Robert Ombres
Keyword(s):  
Thirteenth Century ◽  
Long Time ◽  
The Subject ◽  
The Common ◽  
Common Agenda

By the 1230s Latins and Greeks were riot short of issues for debate or polemic, but the topic of purgatory did have a novel feel about it. The doctrine seems to emerge on the common agenda fairly suddenly, finding no place, for example, in the wide-ranging list of 104 points of divergence drawn up by the Byzantine prelate, Constantine Stilbès, in the wake of the cruel sack of Constantinople by the Latins in 1204. The subject did, however, establish itself as a hardy perennial, and it is proposed to trace its main ramifications up to the death of Emperor Michael viii in 1282, and then to concentrate on the Council of Ferrara–Florence (1438–9). Without a doubt the debates and the constant attempts at reunion were not conducted in isolation from wider cultural, political and military considerations, the kind of considerations that in 1400 would lead the Byzantine emperor to journey as far as England. But here the emphasis will fall on the theological aspects. Moreover, there were also in play forces of inertia, ignorance and mutual incomprehension difficult to assess rationally. The thirteenth-century friar, Humbert of Romans O.P., in discussing what would make for reunion with the Greeks noted how a schism might be continued simply because it had existed for a long time, just like the feud between Guelf and Ghibelline.

Development of a Microdevice for Sorting Motile Bacteria

2011 ◽  
Author(s):  
T. Shioiri ◽  
T. Ishikawa ◽  
K. Numayama-Tsuruta ◽  
Y. Imai ◽  
H. Ueno ◽  
...  
Keyword(s):  
Food Production ◽  
Sewage Treatment ◽  
Food Poisoning ◽  
Culture Method ◽  
Industrial Applications ◽  
Colony Count ◽  
Human Intestine ◽  
Count Method ◽  
Long Time ◽  
Time Of Operation

Bacteria are distributed in various places in nature and in industries, examples include human intestine, sewage treatment, food production and even food poisoning. Thus, the separation of bacteria from various samples is an important technique for medical and industrial applications. In recent years, separation of bacteria was commonly performed by a colony count method. This method, however, takes long time of operation and cannot be applied to bacteria for which culture method has not been established.

Again on relative clause and subordination in Latin

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Gualtiero Calboli
Keyword(s):  
Relative Clause ◽  
Syntactic Structure ◽  
Central Point ◽  
Relative Pronoun ◽  
Case Theory ◽  
Nominative Case ◽  
Subordinate Clauses ◽  
Long Time ◽  
The Subject ◽  
The Law

AbstractI started from the relative clause which occurs in Hittite, and in particular with the enclitic position of the relative pronoun. This is connected with the OV position and this position seems to have been prevailing in Hittite and PIE. The syntactic structure usually employed in Hittite between different clauses is the parataxis. Nevertheless, also the hypotaxis begins to be employed and the best occasion to use it was the diptych as suggested by Haudry, though he didn't consider the most natural and usual diptych: the law, where the crime and the sanction build a natural diptych already in old Hittite. Then I used Justus' and Boley's discussion on the structure of Hittite sentence and found a similarity with Latin, namely the use of an animate subject as central point of a sentence. With verbs of action in ancient languages the subject was normally an animate being, whereas also inanimate subject is employed in modern languages. This seems to be the major difference between ancient and modern structure of a sentence, or, better to say, in Hittite and PIE the subject was an animate being and this persisted a long time, and remained as a tendency in Latin, while in following languages and in classical grammar the subject became a simple nominal “entity” to be predicated and precised with verb and other linguistic instruments. A glance has been cast also to pronouns and particles (sometimes linked together) as instruments of linking nominal variants of coordinate or subordinate clauses and to the development of demonstrative/deictic pronouns. Also in ancient case theory a prevailing position was assured to the nominative case, the case of the subject.

Diplomatic History: A Very Short Introduction

2021 ◽  
Author(s):  
Joseph M. Siracusa
Keyword(s):  
Lessons Learned ◽  
Diplomatic History ◽  
Critical Study ◽  
Short Introduction ◽  
Historical Case ◽  
Road Map ◽  
Nation States ◽  
The Subject ◽  
The Great War

Diplomacy: A Very Short Introduction introduces the subject of diplomatic history, the critical study of the management of relations between nation-states. Based on significant historical case studies—the diplomacy of the American Revolution, the diplomatic origins of the Great War and its aftermath Versailles, the personal summitry behind the night Stalin and Churchill divided Europe, George W. Bush and the coming of the Iraq War, and diplomacy in the age of globalization—there are concrete examples of diplomacy in action while locating the universal role of negotiations. Through these examples we can see what the key element of success is. The lessons learned provide a road map to navigating the challenges of 21st-century diplomacy.

MUSEUM OF ARCHEOLOGY AND ETHNOGRAPHY OF THE IEI UFRC RAS: CREATION AND DEVELOPMENT

2021 ◽  
Vol 0 (3) ◽  
pp. 103-112
Author(s):  
R.M. MUKHAMETZYANOVA-DUGGAL ◽  
◽  
D.A. KAMALETDINOV ◽  
Keyword(s):  
Twentieth Century ◽  
Significant Contribution ◽  
Southern Urals ◽  
Project Work ◽  
Ethnographic Research ◽  
Historical Science ◽  
The Southern Urals ◽  
Research Activities ◽  
Long Time ◽  
The Subject

The subject of the research is the experience of creating and functioning of the Museum of Archeology and Ethnography of the R.G. Kuzeev Institute of Ethnological Research of the UFRC RAS (MAE IEI UFRC RAS), which is an integral part of the academic museum network formed in the second half of the twentieth century. For a long time, the museum has been exhibiting objects that demonstrate the results of archaeological and ethnographic research in the field of studying the history and culture of the peoples of the Southern Urals. The purpose of this article is to provide a brief overview of the creation of the museum, to consider its development to date; to analyze the main directions of work and the results of museum activities, as well as to determine the specifics and prospects for the development of museum activities of the IEI of the UFRC RAS. In the course of the research, the names of scientists and specialists who participated in the formation of collections are named, information about the acquisition of museum funds and state accounting of objects is provided, the features of exposition activity are highlighted, the most interesting exhibitions and current work in this direction are noted, the implementation of excursion activities is shown, the results of project work are highlighted and the most significant projects are described. Attention is also paid to the results of research activities based on archaeological and ethnographic funds, since this work makes a significant contribution to the development of historical science.

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