Aqueous Corrosion of the French LWR Solution Reference Glass First Generation Model

1987 ◽  
Vol 112 ◽  
Author(s):  
E. Mouche ◽  
Vernaz E.
Keyword(s):  
First Generation ◽  
Generation Model ◽  
Order Kinetic ◽  
Aqueous Corrosion ◽  
Interstitial Solution ◽  
Silica Concentration ◽  
Glass Interface ◽  
Advanced Model ◽  
And Diffusion ◽  
Theoretical Results

AbstractExperiments have been performed on the aqueous dissolution of French LWR solution reference glass that have identified key dissolution mechanisms to be considered in modeling. The physical hypotheses on which the model relies are a dissolution rate governed by the silica concentration in solution according to a first order kinetic law, congruent release of the mobile elements at the gel-glass interface, and diffusion of silicic acid in the gel interstitial solution. A comparison of theoretical results obtained by a semi-analytical solution to the model and experimental results suggests some modifications to develop a more advanced model.

Military Defection and the Arab Spring

2017 ◽  
Author(s):  
Risa A. Brooks
Keyword(s):  
First Generation ◽  
Arab World ◽  
Military Leaders ◽  
Civil Military Relations ◽  
Explanatory Factors ◽  
Revolutionary Movements ◽  
Military Relations ◽  
The Arab Spring ◽  
The Impact ◽  
And Diffusion

The protests that began in Tunisia in December 2010, and quickly spread across the Arab world, have drawn significant attention to the impact of militaries and coercive institutions on protests and revolutionary movements. The actions of the militaries were a central determinant of the outcomes of the uprisings of 2010–2011. In Tunisia and Egypt the decision by military leaders to abstain from using force on mass protests to suppress them led to the downfall of the countries’ autocrats. In Syria and Bahrain, militaries defended political leaders with brutal force. In Yemen and Libya, militaries fractured, with some units remaining allied to the leader and using force on his behalf and others defecting. In still other states, leaders and militaries were able to forestall the emergence of large, regime-threatening protests.To explain these divergent outcomes, scholars and analysts have looked to a variety of explanatory factors. These focus on the attributes of the militaries involved, their civil-military relations, the size and social composition of the protests, the nature of the regime’s institutions, and the impact of monarchical traditions. These explanations offer many useful insights, but several issues remain under-studied. These include the impact of authoritarian learning and diffusion on protest trajectory. They also include the endogeneity of the protests to the nature of a country’s civil-military relations (i.e., how preexisting patterns of civil-military relations affected the possibility that incipient demonstrations would escalate to mass protests). Scholars also have been understandably captivated by the aforementioned pattern of military defection-loyalty, focusing on explaining that observed difference at the expense of studying other dependent variables. The next generation of scholarship on the uprisings therefore would benefit from efforts to conceptualize and investigate different aspects of variation in military behavior.Overall, the first-generation literature has proved enormously useful and laid the foundation for a much richer understanding of military behavior and reactions to popular uprisings in the Arab world and beyond.

scholarly journals IMMIGRATION AND DEMOGRAPHICS: CAN HIGH IMMIGRANT FERTILITY EXPLAIN VOTER SUPPORT FOR IMMIGRATION?

2017 ◽  
Vol 23 (5) ◽  
pp. 1815-1837 ◽  
Author(s):  
Henning Bohn ◽  
Armando R. Lopez-Velasco
Keyword(s):  
Capital Accumulation ◽  
First Generation ◽  
Political Process ◽  
The United States ◽  
Political Support ◽  
High Fertility ◽  
Generation Model ◽  
Fertility Rates ◽  
Native Workers ◽  
Future Return

First generation immigrants to the United States have higher fertility rates than natives. This paper analyzes to what extent this factor provides political support for immigration, using an overlapping generation model with production and capital accumulation. In this setting, immigration represents a dynamic trade-off for native workers as more immigrants decrease current wages but increase the future return on their savings. We find that immigrant fertility has surprisingly strong effects on voter incentives, especially when there is persistence in the political process. If fertility rates are sufficiently high, native workers support immigration. Persistence, either due to inertia induced by frictions in the legal system or through expectational linkages, significantly magnifies the effects. Entry of immigrants with high fertility has redistributive impacts across generations similar to pay-as-you-go social security: initial generations are net winners, whereas later generations are net losers.

scholarly journals A generalized fractional-order elastodynamic theory for non-local attenuating media

2020 ◽  
Vol 476 (2238) ◽  
pp. 20200200 ◽  
Author(s):  
Sansit Patnaik ◽  
Fabio Semperlotti
Keyword(s):  
Fractional Order ◽  
Elastic Waves ◽  
Energy Transport ◽  
Transport Processes ◽  
Non Local ◽  
The Many ◽  
Propagation Of Elastic Waves ◽  
And Diffusion ◽  
Fully Coupled ◽  
Theoretical Results

This study presents a generalized elastodynamic theory, based on fractional-order operators, capable of modelling the propagation of elastic waves in non-local attenuating solids and across complex non-local interfaces. Classical elastodynamics cannot capture hybrid field transport processes that are characterized by simultaneous propagation and diffusion. The proposed continuum mechanics formulation, which combines fractional operators in both time and space, offers unparalleled capabilities to predict the most diverse combinations of multiscale, non-local, dissipative and attenuating elastic energy transport mechanisms. Despite the many features of this theory and the broad range of applications, this work focuses on the behaviour and modelling capabilities of the space-fractional term and on its effect on the elastodynamics of solids. We also derive a generalized fractional-order version of Snell’s Law of refraction and of the corresponding Fresnel’s coefficients. This formulation allows predicting the behaviour of fully coupled elastic waves interacting with non-local interfaces. The theoretical results are validated via direct numerical simulations.

The Transformation of the Distribution Process in the Airline Industry Empowered by Information and Communication Technology

2008 ◽  
pp. 254-283 ◽  
Author(s):  
Patrick S. Merten
Keyword(s):  
Information And Communication Technology ◽  
Communication Technology ◽  
Airline Industry ◽  
Distribution System ◽  
Distribution Systems ◽  
First Generation ◽  
Comprehensive Overview ◽  
Distribution Process ◽  
Information And Communication ◽  
And Diffusion

This chapter reviews the historical evolution of the airline market and its first-generation airline reservation and distribution systems. The development and diffusion of computer reservation systems (CRS) and global distribution systems (GDS) is discussed extensively in order to provide a comprehensive overview of the state of business in the 2000s. Based on this evaluation, the influence of modern information and communication technology (ICT) on the airline distribution system environment is discussed. The traditional distribution chain has been transformed into an electronic multi-channel distribution environment. This (r)evolution of the airline market is analysed for the different market participant groups, as the competitive and cooperative situation increases in this cross-influence network industry.

scholarly journals Scintillating Glass Fiber-Optic Neutron Sensors

1994 ◽  
Vol 348 ◽  
Author(s):  
K.H. Abel ◽  
R.J. Arthur ◽  
M. Bliss ◽  
D.W. Brite ◽  
R.L. Brodzinski ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Lithium Silicate ◽  
Aqueous Corrosion ◽  
Transmission Length ◽  
Double Crucible ◽  
Produce Glass ◽  
Glass Interface ◽  
Neutron Sensors ◽  
High Alkali ◽  
Scintillating Fibers

ABSTRACTPacific Northwest Laboratory (PNL) has fabricated cerium-activated lithium silicate scintillating fibers via a hot-downdraw process. These fibers, which, as produced, typically have a transmission length (e−1 length) of greater than 2 meters, are found to undergo aging when subjected to room air. The aging, which is complete in a few weeks, reduces the transmission length to the order of 0.5 meter. Because of the high alkali content of the glass (on the order of 20-30 mole % lithia), we have attributed this aging to aqueous corrosion at the polymer cladding/glass interface. Changes in transmission with chemical treatment of the surface support the corrosion model. Fiber transmission performance has been preserved by modifying the hot-downdraw to a double crucible to produce glass-on-glass waveguides.

Exchange Rate Crises: Experiences of Latin America, East Asia and India

2021 ◽  
pp. 227797872098734
Author(s):  
Manmohan Agarwal ◽  
Vandana T. R.
Keyword(s):  
Developing Countries ◽  
Latin America ◽  
Exchange Rate ◽  
East Asia ◽  
First Generation ◽  
Jel Classification ◽  
The Other ◽  
Generation Model ◽  
Run Up ◽  
Crisis Situations

A number of developing countries mainly in Latin America and East Asia suffered exchange rate crises in the 1990s. India also suffered a crisis in 1991 and another earlier in 1966. We examine the run up to the crises in terms of a few macroindicators suggested by various crisis models. We then examine the aftermath of the crisis, which is largely absent in literature. We seek to explain the pre-crisis and post-crisis situations in the light of various crisis models. We find that crises in East Asia cannot be explained in terms of Krugman’s first-generation model (FGM), but those in the other countries can be explained by Krugman’s model, adding to the debates among crises models. JEL Classification: E420, F310, F320, F410

A Connectionist Modeling Approach to Word Recognition and Dyslexia

1993 ◽  
Vol 4 (5) ◽  
pp. 299-304 ◽  
Author(s):  
Mark S. Seidenberg
Keyword(s):  
Word Recognition ◽  
Computational Modeling ◽  
Simulation Model ◽  
Essential Role ◽  
First Generation ◽  
Generation Model ◽  
Learning To Read ◽  
Modeling Approach ◽  
Connectionist Modeling ◽  
Skilled Reading

Word recognition plays an essential role in learning to read, skilled reading, and dyslexia. The goal of the research I describe is to develop a theory of word recognition that is realized as a connectionist simulation model. Experience with a first-generation model suggests that the approach can reveal general principles underlying word recognition and its impairments. Although computational modeling introduces new problems of method and interpretation, it contributes in an essential way to understanding reading and other aspects of cognition.

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