scholarly journals Modeling Adhesive Hysteresis

Lubricants ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 17
Author(s):  
Anle Wang ◽  
Yunong Zhou ◽  
Martin H. Müser
Keyword(s):  
Energy Loss ◽  
Cohesive Zone ◽  
Mesh Size ◽  
Small Scale ◽  
Leading Order ◽  
Type Analysis ◽  
Central Attention ◽  
Efficient Simulation ◽  
The Third ◽  
Flat Interface

When an elastomer approaches or retracts from an adhesive indenter, the elastomer’s surface can suddenly become unstable and reshape itself quasi-discontinuously, e.g., when small-scale asperities jump into or snap out of contact. Such dynamics lead to a hysteresis between approach and retraction. In this study, we quantify numerically and analytically the ensuing unavoidable energy loss for rigid indenters with flat, Hertzian and randomly rough profiles. The range of adhesion turns out to be central, in particular during the rarely modeled approach to contact. For example, negligible traction on approach but quite noticeable adhesion for nominal plane contacts hinges on the use of short-range adhesion. Central attention is paid to the design of cohesive-zone models for the efficient simulation of dynamical processes. Our study includes a Griffith’s type analysis for the energy lost during fracture and regeneration of a flat interface. It reveals that the leading-order corrections of the energy loss are due to the finite-range adhesion scale at best, with the third root of the linear mesh size, while leading-order errors in the pull-off force disappear linearly.

Realizing Stable High‐Performance and Low‐Energy‐Loss Ternary Photovoltaics through Judicious Selection of the Third Component

Solar RRL ◽  
2021 ◽  
pp. 2100450
Author(s):  
Bing-Huang Jiang ◽  
Yi-Peng Wang ◽  
Yu-Wei Su ◽  
Jia-Fu Chang ◽  
Chu-Chen Chueh ◽  
...  
Keyword(s):  
Energy Loss ◽  
High Performance ◽  
Low Energy ◽  
The Third ◽  
Selection Of

Early Democracy Was Widespread

2020 ◽  
pp. 29-61
Author(s):  
David Stasavage
Keyword(s):  
Small Scale ◽  
Population Movements ◽  
The Third ◽  
Economic Production ◽  
History Of ◽  
State Bureaucracy ◽  
Ancient Mesopotamia

This chapter begins with the democratic history of Athens. It explains how early democracy was more likely to flourish in small-scale settings, in instances where rulers lacked the coercive potential provided by a state bureaucracy, and when rulers found it difficult to monitor economic production and population movements. The chapter draws attention to ancient Mesopotamia during the third and second millennia BCE as one of the oldest examples of early democracy. It mentions the Danish Assyriologist named Thorkild Jacobsen who asserted that governance by assemblies was common in Mesopotamia before centralizing rulers destroyed this pattern. It also discusses debates about the ancient Indian republics that became colored by the colonial context.

scholarly journals Jet tomography in high-energy nuclear collisions

2019 ◽  
Vol 206 ◽  
pp. 04004 ◽  
Author(s):  
Ben-Wei Zhang ◽  
Guo-Yang Ma ◽  
Wei Dai ◽  
Sa Wang ◽  
Shan-Liang Zhang
Keyword(s):  
Energy Loss ◽  
Heavy Ion ◽  
High Energy ◽  
Jet Quenching ◽  
Parton Energy Loss ◽  
Matrix Elements ◽  
Leading Order ◽  
Nuclear Collisions ◽  
Ion Collisions ◽  
Jet Observables

When an energetic parton traversing the QCD medium, it may suffer multiple scatterings and lose energy. This jet quenching phenomenon may lead to the suppression of leading hadron productions as well as medium modifications of full jet observables in heavy-ion collisions. In this talk we discuss the nuclear modificationfactors and yield ratios of identified meson such as η, ρ0, φ, ω, and $ K_{\rm{S}}^0 $ as well as π meson at large pT in A+A collisions at the next to-leading order (NLO) with high-twist approach of parton energy loss. Then we discuss a newly developed formalism of combing NLO matrix elements and parton shower (PS) for initial hard production with parton energy loss in the QGP, and its application in investigating massivegauge boson(Z0/W±)tagged jet productions and b $ \bar {b} $ dijet correlations in Pb+Pb at the LHC.

scholarly journals Balanced reconnection intervals: four case studies

2008 ◽  
Vol 26 (12) ◽  
pp. 3897-3912 ◽  
Author(s):  
A. D. DeJong ◽  
A. J. Ridley ◽  
C. R. Clauer
Keyword(s):  
Case Studies ◽  
Large Scale ◽  
The Other ◽  
Small Scale ◽  
Polar Cap ◽  
Reconnection Rate ◽  
Magnetospheric Convection ◽  
The Third ◽  
New Name ◽  
Definition Of

Abstract. During steady magnetospheric convection (SMC) events the magnetosphere is active, yet there are no data signatures of a large scale reconfiguration, such as a substorm. While this definition has been used for years it fails to elucidate the true physics that is occurring within the magnetosphere, which is that the dayside merging rate and the nightside reconnection rate balance. Thus, it is suggested that these events be renamed Balanced Reconnection Intervals (BRIs). This paper investigates four diverse BRI events that support the idea that new name for these events is needed. The 3–4 February 1998 event falls well into the classic definition of an SMC set forth by Sergeev et al. (1996), while the other challenge some previous notions about SMCs. The 15 February 1998 event fails to end with a substorm expansion and concludes as the magnetospheric activity slowly quiets. The third event, 22–23 December 2000, begins with a slow build up of magnetospheric activity, thus there is no initiating substorm expansion. The last event, 17 February 1998, is more active (larger AE, AL and cross polar cap potential) than previously studied SMCs. It also has more small scale activity than the other events studied here.

Examination of the Transferability of CTOA From Small-Scale DWTT to Full-Scale Pipe Geometries Using a Cohesive Zone Model

2020 ◽  
Author(s):  
Chris Bassindale ◽  
Xin Wang ◽  
William R. Tyson ◽  
Su Xu
Keyword(s):  
Finite Element ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Element Model ◽  
Full Scale ◽  
Opening Angle ◽  
Small Scale ◽  
Zone Model ◽  
Pipe Model ◽  
Good Agreement

Abstract In this work, the cohesive zone model (CZM) was used to examine the transferability of the crack tip opening angle (CTOA) from small-scale to full-scale geometries. The pipe steel STPG370 was modeled. A drop-weight tear test (DWTT) model and pipe model were studied using the finite element code ABAQUS 2017x. The cohesive zone model was used to simulate crack propagation in 3D. The CZM parameters were calibrated based on matching the surface CTOA measured from a DWTT finite element model to the surface CTOA measured from the experimental DWTT specimen. The mid-thickness CTOA of the DWTT model was in good agreement with the experimental value determined from E3039 and the University of Tokyo group’s load-displacement data. The CZM parameters were then applied to the pipe model. The internal pressure distribution and decay during the pipe fracture process was modeled using the experimental data and implemented through a user-subroutine (VDLOAD). The mid-thickness CTOA from the DWTT model was similar to the mid-thickness CTOA from the pipe model. The average surface CTOA of the pipe model was in good agreement with the average experimental value. The results give confidence in the transferability of the CTOA between small-scale specimens and full-scale pipe.

scholarly journals Standardization of Propagation Models for Terrestrial Cellular Systems: A Historical Perspective

2020 ◽  
Author(s):  
Harsh Tataria ◽  
Katsuyuki Haneda ◽  
Andreas F. Molisch ◽  
Mansoor Shafi ◽  
Fredrik Tufvesson
Keyword(s):  
Mobile Communications ◽  
Wireless Systems ◽  
Cellular Systems ◽  
Propagation Model ◽  
Small Scale ◽  
Propagation Models ◽  
The Third ◽  
Single Antenna ◽  
Deterministic Modelling ◽  
Wide Range

Abstract Propagation models constitute a fundamental building block of wireless communications research. Before we build and operate real systems, we must understand the science of radio propagation, and develop channel models that both reflect the important propagation processes and allow a fair comparison of different systems. In the past five decades, wireless systems have gone through five generations, from supporting voice applications to enhanced mobile broadband. To meet the ever increasing data rate demands of wireless systems, frequency bands covering a wide range from 800 MHz to 100 GHz have been allocated for use. The standardization of these systems started in the early/mid 1980s in Europe by the European Telecommunications Standards Institute with the advent of Global System for Mobile Communications. This motivated the development of the first standardized propagation model by the European Cooperation in Science and Technology (COST) 207 working group. These standardization activities were continued and expanded for the third, fourth, and fifth generations of COST, as well as by the Third Generation Partnership Project, and the International Telecommnunication Union. This paper presents a historical overview of the standardized propagation models covering first to fifth-generation systems. In particular, we discuss the evolution and standardization of pathloss models, as well as large and small-scale fading parameters for single antenna and multiple antenna systems. Furthermore, we present insights into the progress of deterministic modelling across the five generations of systems, as well as discuss more advanced modelling components needed for the detailed simulations of millimeter-wave channels. A comprehensive bibliography at the end of the paper will aid the interested reader to dig deeper.

The Development of Embossed Goldwork in Bronze Age Europe

2000 ◽  
Vol 80 (1) ◽  
pp. 27-65 ◽  
Author(s):  
Stuart Needham
Keyword(s):  
Bronze Age ◽  
The Other ◽  
Early Bronze Age ◽  
Small Scale ◽  
Time And Space ◽  
Parallel Development ◽  
The Third ◽  
Third Millennium ◽  
Third Millennium Bc ◽  
Craft Skills

The discovery of a pair of armlets from Lockington and the re-dating of the Mold cape, add substance to a tradition of embossed goldworking in Early Bronze Age Britain. It is seen to be distinct in morphology, distribution and decoration from the other previously defined traditions of goldworking of the Copper and Early Bronze Ages, which are reviewed here. However, a case is made for its emergence from early objects employing ‘reversible relief to execute decoration and others with small-scale corrugated morphology. Emergence in the closing stages of the third millennium BC is related also to a parallel development in the embossing of occasional bronze ornaments. Subsequent developments in embossed goldwork and the spread of the technique to parts of the Continent are summarized. The conclusions address the problem of interpreting continuity of craft skills against a very sparse record of relevant finds through time and space.

The rate of energy loss of high-energy cosmic ray muons

1963 ◽  
Vol 275 (1362) ◽  
pp. 391-410 ◽  
Keyword(s):  
Energy Spectrum ◽  
Energy Loss ◽  
Sea Level ◽  
Cosmic Ray ◽  
Nuclear Interaction ◽  
High Energy ◽  
Level Energy ◽  
Muon Spectrum ◽  
The Third ◽  
Muon Mass

The rate of energy loss of muons is examined by com paring the observed depth-intensity relation with that predicted from a knowledge of the sea-level energy spectrum of cosmic ray muons. The evidence for each of the parameters entering into the analysis is assessed and estimates are made of the sea-level muon spectrum up to 10000 GeV and the depth-intensity relation down to 7000 m.w.e. The effect of range-straggling on the underground intensities is considered and shown to be important at depths below 1000 m.w.e. Following previous workers the energy loss relation is written as -d E /d x =1.88+0.077 in E ' m / mc 2 + b E MeV g -1 cm 2 , where E ' m is the maximum transferrable energy in a /i-e collision and m is the muon mass. The first two terms give the contribution from ionization (and excitation) loss and the third term is the combined contribution from pair production, bremsstrahlung and nuclear interaction. The best estimate of the coefficient b from the present work is b = (3.95 + 0.25) x 10 -6 g -1 cm 2 over the energy range 500 to 10000 GeV, which is close to the theoretical value of 4.0 x 10 -6 g -1 cm 2 . It is concluded that there is no evidence for any marked anomaly in the energy loss processes for muons of energies up to 10000 GeV.

The Persona and the Addressee in Juvenal Satire 11

Ramus ◽  
1990 ◽  
Vol 19 (2) ◽  
pp. 160-168
Author(s):  
F.M.A. Jones
Keyword(s):  
Small Scale ◽  
Ad Hominem ◽  
The Third ◽  
The Difference ◽  
Further Development ◽  
The Voice

The approach to the Satires of Juvenal via the persona theory is well-known and has been productive. Somewhat less notice has been given to the fact that a considerable number of the satires have their persona moulded around another character, an addressee or an interlocutor, or sometimes an important narrative figure. Such characters ‘justify’ the persona, which can now be seen as a kind of ad hominem irony. This matter is intricately linked with the role of indignatio. Thus indignation, programmed in the first satire, becomes a little suspect in Laronia's mouth in the second. Laronia is a small scale character, but the techniques used in her regard appear again in the third satire, where the difference between Juvenal and Umbricius reveals the inadequacy of indignatio a little more clearly. The difference between the treatment of Crispinus and of Domitian in the fourth satire carries this process further. In the fifth, Juvenal tries to rouse the abject Trebius, but in his own apostrophe to Virro (Sat. 5.107f.) shows that indignatio is not, perhaps, appropriate at all. The role of indignatio diminishes further in the later satires, noticeably in the ninth, where Juvenal's tone is one of banter and Naevolus reveals his own unpleasantness. Much of this process has been charted by S. Braund in a book on the seventh, eighth, and ninth satires. The argument can be resumed with the eleventh satire where there is a further development. In the earlier satires which use address or dialogue there is an impressive realism in dramatic terms about the confrontation and psychology. In the eleventh (and even more, the twelfth) the development of the techniques of irony begins to intrude on the dramatic plausibility: the voice assumed in the poem becomes more aware of the audience as well as the addressee. As the beginning of a demonstration of this change I now provide an analysis of the use of Persicus in the eleventh satire.

scholarly journals Investigating Some Technical Issues on Cohesive Zone Modeling of Fracture

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
John T. Wang
Keyword(s):  
Cohesive Zone ◽  
Process Zone ◽  
Cohesive Zone Modeling ◽  
Small Scale ◽  
Zone Length ◽  
Cohesive Model ◽  
Cohesive Models ◽  
Cohesive Laws ◽  
Technical Issues ◽  
Linear Softening

This study investigates some technical issues related to the use of cohesive zone models (CZMs) in modeling the fracture of materials with negligible plasticity outside the fracture process zone. These issues include: (1) why cohesive laws of different shapes can produce similar fracture predictions, (2) under what conditions CZM predictions have a high degree of agreement with linear elastic fracture mechanics (LEFM) analysis results, (3) when the shape of cohesive laws becomes important in the fracture predictions, and (4) why the opening profile along the cohesive zone length (CZL) needs to be accurately predicted. Two cohesive models were used in this study to address these technical issues. They are the linear softening cohesive model and the Dugdale perfectly plastic cohesive model. Each cohesive model uses five cohesive laws of different maximum tractions. All cohesive laws have the same cohesive work rate (CWR) defined by the area under the traction–separation curve. The effects of the maximum traction on the cohesive zone length and the critical remote applied stress are investigated for both models. The following conclusions from this study may provide some guidelines for the prediction of fracture using CZM. For a CZM to predict a fracture load similar to that obtained by an LEFM analysis, the cohesive zone length needs to be much smaller than the crack length, which reflects the small-scale yielding condition requirement for LEFM analysis to be valid. For large-scale cohesive zone cases, the predicted critical remote applied stresses depend on the shape of the cohesive models used and can significantly deviate from LEFM results. Furthermore, this study also reveals the importance of accurately predicting the cohesive zone profile for determining the critical remote applied load.

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