scholarly journals A local contact systolic inequality in dimension three

2020 ◽  
Author(s):  
Gabriele Benedetti ◽  
Jungsoo Kang
Keyword(s):  
Local Contact ◽  
Systolic Inequality

Investigations Into Asperity Persistence in Heavily Loaded Contacts

1999 ◽  
Vol 121 (3) ◽  
pp. 441-448 ◽  
Author(s):  
I. Lee-Prudhoe ◽  
R. S. Sayles ◽  
A. Kaderic
Keyword(s):  
Rough Surface ◽  
Simulation Models ◽  
Simulation Method ◽  
Asperity Contact ◽  
Local Contact ◽  
Before And After ◽  
Indentation Tests ◽  
Mechanisms Of Persistence ◽  
Contact Pressures ◽  
Smooth Roller

Experimental results are presented along the lines of the early work of Moore (1948) where a hard smooth roller is pressed into a softer rough surface to study the resulting real to apparent areas of contact and their associated local contact pressures. Results are presented for a hard steel roller deforming mild-steel and aluminum-alloy rough surface specimens. An analysis of the local contact mechanics is performed before and after indentation using a recently developed numerical elastic contact simulation method which allows local asperity contact pressures and areas to be studied in detail. The method is shown to reveal the level and distribution of pressures and asperity contact areas prevalent during the indentation process, and therefore allows the contribution of elastic and plastic load support to be quantified. The persistence of asperities during such indentation tests is discussed in terms of the pressures the asperities can support in relation to reported mechanisms of persistence. Results of subsequent sub-surface stresses are also presented and discussed in terms of how the method might be used to create an elastic-plasticdeformation model that can account for asperity persistence in future numerical contact simulation models.

scholarly journals La dimension pragmatico-discursive du français en contact

2014 ◽  
Vol 7 (1) ◽  
pp. 62-92 ◽  
Author(s):  
Martina Drescher
Keyword(s):  
Language Contact ◽  
African Country ◽  
Local Level ◽  
Direct Interaction ◽  
Linguistic Landscape ◽  
Methodological Issues ◽  
Local Contact ◽  
Medical Issues ◽  
Mitigation Technique

The aim of this paper is two-fold : First it argues for a stronger consideration of the pragmatic and discourse level in research on language contact. Secondly it contributes to the pragmatics of a specific regional variety of French, namely Cameroonian French. Starting with a picture of the complex linguistic landscape of this multilingual African country, the paper stresses the importance of the pragmatic and discourse level by raising some of the crucial theoretical and methodological issues that a broader, usage-based view on language contact has to cope with. First it suggests that pragmatic and discourse conventions may be influenced by the local contact languages and secondly it emphasizes that they may not be specific to a language, but be shared by a much larger and encompassing community of discourse. A case study of Cameroonian radio phone-ins where callers seek advice on medical issues points out some of these conventions. Here the participants establish a specific participation framework that avoids direct interaction between caller and expert while the host is set in as a mediator. This global mitigation technique then allows for quite direct realisations of the advice at a local level.

Phonological Complexity: Bernese Swiss German in Ohio and Misiones

2021 ◽  
Vol 18 (2) ◽  
pp. 1-26
Author(s):  
Robert Klosinski ◽  
Andrew D. Hoffman
Keyword(s):  
United States ◽  
Language Change ◽  
The United States ◽  
Heritage Languages ◽  
Swiss German ◽  
Local Contact ◽  
Additional Reference ◽  
Phonological Complexity

Abstract This article investigates the notion of complexity as it applies to two phonological characteristics of Heritage Bernese Swiss German, namely /l/-vocalization and /nd/-velarization. We survey literature on the role of complexity in language change generally, as well as how it applies to heritage languages specifically. We then present findings from our study of two groups of Heritage Bernese speakers, one in the United States and one in Argentina, with additional reference to the local contact languages. Our findings suggest that the loss of /nd/-velarization in Misiones, Argentina is most likely the result of an internally-driven reduction of complexity. For both the Ohio and Misiones communities, however, /l/-vocalization has been maintained. We conclude by discussing the importance of research into language dyads beyond those in the United States as well as pursuing research on lesser-studied heritage languages.

Some Observations of Chaotic Vibration Phenomena in High-Speed Rotordynamics

1991 ◽  
Vol 113 (1) ◽  
pp. 50-57 ◽  
Author(s):  
F. F. Ehrich
Keyword(s):  
Numerical Model ◽  
High Speed ◽  
Chaotic Behavior ◽  
Narrow Region ◽  
System A ◽  
Vibratory Response ◽  
Local Contact ◽  
Jeffcott Rotor ◽  
Subharmonic Response ◽  
Static Part

Subharmonic response in rotordynamics may be encountered when a rotor is operated with its rotational centerline eccentric to that of a close clearance static part, so that local contact can take place during each orbit when the rotor is excited by residual unbalance. The rotor will tend to bounce at or near its fundamental frequency when the rotor is operated at or near a speed which is a whole number [n] times that frequency. Using a simple numerical model of a Jeffcott rotor mounted on a nonlinear spring, it is found that the vibratory response in the transition zone midway between adjacent zones of subharmonic response has all the characteristics of chaotic behavior. The transition from subharmonic to chaotic response has a complex substructure which involves a sequence of bifurcations of the orbit with variations in speed. This class of rotordynamic behavior was confirmed and illustrated by experimental observations of the vibratory response of a high-speed turbomachine, operating at a speed between 8 and 9 times its fundamental rotor frequency when in local contact across a clearance in the support system. A narrow region between zones of 8th order and 9th order subharmonic response was identified where the response had all the characteristics of the chaotic motion identified in the numerical model.

Determination of the local contact potential difference of PTCDA on NaCl: a comparison of techniques

2009 ◽  
Vol 20 (26) ◽  
pp. 264012 ◽  
Author(s):  
S A Burke ◽  
J M LeDue ◽  
Y Miyahara ◽  
J M Topple ◽  
S Fostner ◽  
...  
Keyword(s):  
Contact Potential Difference ◽  
Potential Difference ◽  
Contact Potential ◽  
Local Contact ◽  
Comparison Of Techniques

scholarly journals Fiberwise convexity of Hill’s lunar problem

2017 ◽  
Vol 09 (04) ◽  
pp. 571-630 ◽  
Author(s):  
Junyoung Lee
Keyword(s):  
Energy Level ◽  
Contact Structure ◽  
Finsler Geometry ◽  
Critical Energy ◽  
Critical Value ◽  
Finsler Metrics ◽  
Tight Contact ◽  
Systolic Inequality ◽  
Geodesic Problem ◽  
Hill's Lunar Problem

In this paper, we prove the fiberwise convexity of the regularized Hill’s lunar problem below the critical energy level. This allows us to see Hill’s lunar problem of any energy level below the critical value as the Legendre transformation of a geodesic problem on [Formula: see text] with a family of Finsler metrics. Therefore the compactified energy hypersurfaces below the critical energy level have the unique tight contact structure on [Formula: see text]. Also one can apply the systolic inequality of Finsler geometry to the regularized Hill’s lunar problem.

scholarly journals Dynamics of intraocular temperature during local hypothermia (experimental study and mathematical modeling)

2019 ◽  
pp. 383-388
Author(s):  
Lukyan Anatychuk ◽  
Roman Kobyliansky ◽  
Nataliya Pasyechnikova ◽  
Volodymyr Naumenko ◽  
Oleg Zadorozhnyy ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Biological Tissues ◽  
Comsol Multiphysics ◽  
Rabbit Eye ◽  
Local Contact ◽  
Group 2 ◽  
Local Hypothermia ◽  
Group 1

Therapeutic hypothermia currently is successfully in various fields of medicine to protect biological tissues from ischemia. However the issue of changes in intraocular temperature under hypothermia remains poorly understood. Purpose. To study the dynamics of intraocular temperature in conditions of local hypothermia and on the basis of the obtained data to develop a mathematical model of thermophysical processes in the rabbit eye. Materials and methods. An in vivo experiment was performed on 10 rabbits (20 eyes). In group 1 (5 rabbits, 10 eyes), epibulbar and intraocular temperature was measured after local contact hypothermia through closed eyelids, in group 2 (5 rabbits, 10 eyes) after local contact hypothermia directly through the cornea. ока безпосередньо через рогівку. Для гіпотермії застосовувався гелевий акумулятор холоду температурою -10 °С. Для вимірювання температури в різних відділах ока застосовувався термоелектричний пристрій, розроблений Інститутом термоелектрики НАН і МОН України та ДУ «Інститут очних хвороб і тканинної терапії ім. В. П.Філатова НАМН України». Для розробки математичної моделі теплофізичних процесів в оці кролика використано пакет прикладних програм COMSOL Multiphysics. Результати. Температура склоподібного тіла в 1-й і 2-й групі тварин знизилася в порівнянні з вихідними даними відповідно на 2,8 °С і 5,4 °С. Температурний градієнт між зовнішньою поверхнею рогівки і середньою частиною склоподібного тіла ока кролика в 1-й групі становив 7,1 °С, у 2-й групі – 9,2 °С. На підставі отриманих експериментальних даних було розроблено схематичну, математичну та комп’ютерну моделі ока кролика з урахуванням його теплофізичних особливостей, кровообігу, процесів метаболізму і теплообміну. Висновки. У разі локальної контактної гіпотермії очей кролика відбувається зниження епібульбарної температури і температури внутрішньоочних середовищ, як під час охолодження безпосередньо зовнішньої поверхні рогівки, так і під час впливу холоду через закриті повіки. Ключові слова: внутрішньоочна температура, локальна гіпотермія, око кролика, математична модель ока. Для цитування: Анатичук ЛІ, Пасєчнікова НВ, Науменко ВО, Задорожний ОС, Назаретян РЕ, Кобилянський РР, Верешко ЄЮ. Динаміка внутрішньоочної температури в умовах локальної гіпотермії (експериментальне дослідження та математичне моделювання). Журнал Національної академії медичних наук України. 2019;25(4):383–8

scholarly journals Forensic Engineering Analysis Of Dynamic Wheel Tire Impact Ejection Of Manhole Covers

2007 ◽  
Vol 24 (2) ◽  
Author(s):  
Jon O. Jacobson ◽  
Kravitz Michael
Keyword(s):  
Focal Point ◽  
Contact Stresses ◽  
Engineering Analysis ◽  
Local Contact ◽  
Forensic Engineering ◽  
Tire Forces

This Paper Will Examine The Effect Of Vehicle Tires Driving Over A Street Hardware Manhole Cover That Was Not Properly Seated And Resulted In The Motion Of The Manhole Cover Which Eventually Either Became Unseated And Moved Along The Roadway Surface Or Failed And Fell Into The Manhole. As A Result Of The Open Uncovered Manhole, A Vehicle Tire Struck The Open Manhole Resulting In The Driver Losing Control Of The Vehicle And Crashing Into A Tree. Several Of The Passengers Were Injured And A Law Suit Ensued. The Issue Of Notice Was The Focal Point Of The Case. The Defendants Argument Was That It Had No Notice Of The Defect And The Plaintiffs Argument Was That The Defendant Had Actual And Constructive Notice Because The Defect Was Caused By The Roadway Resurfacing Project. Two Examples Will Be Presented Showing How A Manhole Cover Can Be Dislodged They Are: 1) The Dynamic Expulsion From Tire Forces On The Rocking Manhole Cover, And 2) The Fracture Of The Manhole Cover From Local Contact Stresses From A Misaligned Adjusting Riser Frame Installed During The Repaving.

scholarly journals Hanging stump prosthesis without socket for bad above-knee stumps

1985 ◽  
Vol 9 (3) ◽  
pp. 154-156 ◽  
Author(s):  
N. Chand ◽  
R. K. Srivastava ◽  
A. R. Maish
Keyword(s):  
Hip Joint ◽  
Knee Prosthesis ◽  
Outer Side ◽  
New Delhi ◽  
Rehabilitation Team ◽  
Local Contact ◽  
Metallic Ring ◽  
Vertical Bars

This prosthesis was developed in the Department of Rehabilitation, Safdarjang Hospital, New Delhi, India to deal with the problems of badly formed or difficult above-knee stumps. Bad stumps are still a challenge for the rehabilitation team due to the difficulty in fitting the prosthesis which is the first stage in the total rehabilitation of the amputee. It is the author's observation that those cases with bad above-knee stumps who are fitted with a prosthesis with some type of socket keep attending the prosthetic section complaining of pain. The pain in most of these cases is due to local contact of the stump surface with the socket. None of the prostheses already available can deal with this problem effectively. The hanging stump prosthesis without socket has been developed on the principle of no socket, no contact, no pain. This prosthesis has no socket but a metallic ring consisting of a well padded, well moulded ischial seat. This metallic ring is attached to the hollowed out wooden thigh piece by medial and lateral vertical bars. The outer side of the metallic ring is attached to the pelvic belt through the hip joint. The rest of the prosthesis is similar to the standard above-knee prosthesis.

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