scholarly journals Theoretical Assessment of Thermodynamic Stability in Nanocrystalline Metallic Alloys

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3408 ◽  
Author(s):  
Antonio Mario Locci
Keyword(s):  
Thermodynamic Stability ◽  
Theoretical Description ◽  
Point Of View ◽  
Theoretical Point ◽  
Qualitative Comparison ◽  
Theoretical Approaches ◽  
Model Predictions ◽  
Cr System ◽  
Experimental Findings ◽  
Theoretical Assessment

Thermal stability in nanocrystalline alloys has been extensively explored while using both experimental and theoretical approaches. From the theoretical point of view, the vast majority of the models proposed in the literature have been implicitly limited to immiscible or dilute systems and thus lack the necessary generality to make predictions for different alloying interactions and in the case of intermetallic compounds formation. In this work, a general theoretical description for the case of binary W-based alloys is presented. It is shown that a critical value Ω ∗ of the interaction energy in the grain boundary Ω ( g b ) exists, such that the condition Ω ( g b ) < Ω ∗ can be regarded as a criterion for thermodynamic stability assessment. A procedure for calculating the value of Ω ∗ for each specific alloy is illustrated. A preliminary qualitative comparison between the model predictions and properly selected experimental findings taken from the literature and related to the W-Cr system is also provided.

scholarly journals Modeling and theoretical description of magnetic hybrid materials—bridging from meso- to macro-scales

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Andreas M. Menzel ◽  
Hartmut Löwen
Keyword(s):  
Colloidal Particles ◽  
Colloidal Particle ◽  
Theoretical Description ◽  
Point Of View ◽  
Material Behavior ◽  
Theoretical Point ◽  
Mechanical Stiffness ◽  
Theoretical Approaches ◽  
Theoretical Predictions ◽  
Particle Level

Abstract Magnetic gels and elastomers consist of magnetic or magnetizable colloidal particles embedded in an elastic polymeric matrix. Outstanding properties of these materials comprise reversible changes in their mechanical stiffness or magnetostrictive distortions under the influence of external magnetic fields. To understand such types of overall material behavior from a theoretical point of view, it is essential to characterize the substances starting from the discrete colloidal particle level. It turns out that the macroscopic material response depends sensitively on the mesoscopic particle arrangement. We have utilized and developed several theoretical approaches to this end, allowing us both to reproduce experimental observations and to make theoretical predictions. Our hope is that both these paths help to further stimulate the interest in these fascinating materials.

scholarly journals Investigation on the Thermodynamic Stability of Nanocrystalline W-Based Alloys: A Combined Theoretical and Experimental Approach

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7179
Author(s):  
Francesco Torre ◽  
Claudio Mingazzini ◽  
Daniele Mirabile Gattia ◽  
Teodor Huminiuc ◽  
Antonio Rinaldi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermodynamic Stability ◽  
Experimental Approach ◽  
Metal Alloys ◽  
Model Predictions ◽  
The Stability ◽  
Experimental Findings ◽  
Constituent Elements ◽  
Segregated Structure ◽  
Nanostructured Metal

The stability of nanostructured metal alloys is currently being extensively investigated, and several mathematical models have been developed to describe the thermodynamics of these systems. However, model capability in terms of thermal stability predictions strongly relies on grain boundary-related parameters that are difficult to measure or estimate accurately. To overcome this limitation, a novel theoretical approach is proposed and adopted in this work to identify W-based nanocrystalline alloys which are potentially able to show thermodynamic stability. A comparison between model outcomes and experimental findings is reported for two selected alloys, namely W-Ag and W-Al. Experimental results clearly highlight that W-Ag mixtures retain a segregated structure on relatively coarse length scales even after prolonged mechanical treatments. Moreover, annealing at moderate temperatures readily induces demixing of the constituent elements. In contrast, homogeneous nanostructured W-Al solid solutions are obtained by ball milling of elemental powders. These alloys show enhanced thermal stability with respect to pure W even at high homologous temperatures. Experimental evidences agree with model predictions for both the investigated systems.

MECHANISMS OF STATE GOVERNANCE OF THE REGION'S TOURIST BRAND

2017 ◽  
Author(s):  
Viktoriia Marchenko ◽  
◽  
Olena Uhodnikova ◽  
Keyword(s):  
Public Management ◽  
Brand Management ◽  
Tourism Industry ◽  
Point Of View ◽  
Theoretical Point ◽  
Territorial Development ◽  
Tourist Attractions ◽  
State Management ◽  
Theoretical Approaches ◽  
Decentralization Reform

The development of the tourism industry takes place in conditions of high competition. To ensure competitiveness in the market of tourist services, an important element of promotion is the formation of an effective tourist brand. Thus, the article is devoted to the topical issue of finding effective ways to implement mechanisms for public management of tourism brand development on the example of territories, in the context of decentralization reform in Ukraine. These studies are important both from a scientific and theoretical point of view, and from the point of view of business practice in modern market relations. The purpose of the article is to find ways to improve the system of public management of the tourist brand of the territories. The market is oversaturated with traditional forms of tourist attractions. To enter new markets or increase your target audience, you need to develop original projects and promote a non-standard tourism product. Such a product can be various innovative projects of different types of tourism, as a type of tourism that is actively developing and attracts additional attention of tourists to areas that have potentially interesting tourist resources. The article is devoted to the development of the theoretical foundations of public administration for the promotion of the tourist brand of the regions. Theoretical approaches to the definition of the concept of tourism brand management in terms of territorial development are analyzed. The leading world practices of formation of tourist brands of territories are analyzed. Domestic trends in the development of tourism brands are identified, taking into account the opportunities for the creation of public management systems for tourism brands at the regional level. The expediency of introduction of initiatives on introduction of mechanisms of the state management of a tourist brand of territories is developed and substantiated. The results of developments can be used in practical activities to develop the tourism potential of the regions.

Noun Phrases

2019 ◽  
pp. 334-357
Author(s):  
Evelien Keizer
Keyword(s):  
Internal Structure ◽  
Noun Phrase ◽  
Noun Phrases ◽  
Point Of View ◽  
Theoretical Point ◽  
Cognitive Perspective ◽  
General Characterization ◽  
Theoretical Approaches ◽  
English Noun

This chapter provides a brief overview of some widely debated issues in discussions of the English noun phrase, and illustrates how these issues have been dealt with in different theoretical approaches. After a general characterization of the noun phrase from a pre-theoretical point of view, the chapter proceeds to discuss the internal structure of the noun phrase from a generative, functional, and cognitive perspective. Subsequently, the differences between these approaches are illustrated by addressing two basic notions in the analysis of English noun phrases: headedness (in regular noun phrases, as well as in headless and pseudo-partitive noun phrases) and the distinction between relational and non-relational nouns (and, consequently, between complements and modifiers). In both cases the various types of criteria for analysis are discussed, as well as some problems in applying these criteria.

scholarly journals Thinking about Entry of Firms: A Theoretical Discussion

2016 ◽  
Vol 9 (2) ◽  
pp. 46 ◽  
Author(s):  
Christian Garavaglia
Keyword(s):  
Interdisciplinary Research ◽  
International Entrepreneurship ◽  
Point Of View ◽  
Theoretical Point ◽  
Theoretical Discussion ◽  
Industry Life Cycle ◽  
Theoretical Approaches ◽  
Long Run ◽  
Role Of Information

<p class="abstract">This paper analyses the factors that play a role in determining entry of new firms into markets from a theoretical point of view. We analyse the traditional interpretation of entry as a mechanism of re-equilibrating profits towards their long-run level. Then, we concentrate on other theoretical approaches, showing how the characteristics of technological innovation, the endowment of skills and competencies of the entrants, the role of information signals, the phases of the industry life cycle, the sociological concepts of legitimization and competition, and the psychological aspects might play fundamental roles in explaining new entry. The paper debates possible cross-fertilizations among theories: The discussion results in some fruitful intertwinements among the different relevant features about entry and spawns new collaborative and interdisciplinary research to create additional knowledge about entry. Insights about international entrepreneurship (IE) are also discussed.</p>

scholarly journals Theoretical Description for the Galvanostatic Electrode Pretreatment, Yielding Thiourea-Based Active Surface for Cathodic Conducting Polymer Deposition

2020 ◽  
Vol 9 (3) ◽  
pp. 1333-1338
Keyword(s):  
Conducting Polymer ◽  
Active Surface ◽  
Double Electric Layer ◽  
Theoretical Description ◽  
Point Of View ◽  
Linear Stability Theory ◽  
Theoretical Point ◽  
Cathodic Deposition ◽  
Surface Pretreatment ◽  
Polymer Deposition

The system with the electrode modification by thiourea basic derivatives for conducting polymer indirect cathodic deposition has been described from the theoretical point of view. The electrode pretreatment process has been analyzed using the linear stability theory and bifurcation analysis. It was shown that the steady-state is realized rapidly and provides efficient surface pretreatment. On the other hand, the oscillatory and monotonic behavior, in this case, is also possible due to the double electric layer capacitance changes during the doping stage and electrochemical reaction.

scholarly journals Quest for New Data: Ionizing Radiation Metrology in the Presence of Laser-Assisted Scattering Processes

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 94
Author(s):  
Davide Bianco ◽  
Filomena Loffredo ◽  
Maria Quarto ◽  
Luigi Santamaria Amato
Keyword(s):  
Ionizing Radiation ◽  
Cross Sections ◽  
Emission Spectra ◽  
Point Of View ◽  
Experimental Point ◽  
Space Vehicles ◽  
Electronic Interaction ◽  
Theoretical Point ◽  
Radiation Physics ◽  
Theoretical Approaches

Radiation metrology is crucial in space, for instance in monitoring the conditions on-board space vehicles. The energy released in matter by ionizing radiation is due to the atomic and molecular ionization processes, which have been investigated for several decades from both a theoretical and an experimental point of view. Electronic excitation and ionization cross-section are of particular interest in radiation physics, because of their role in the radiation–matter interaction process. Recently, experimental findings have shown that the interplay with a laser field can strongly modify the electronic interaction probabilities and emission spectra. These phenomena are still not completely understood from a theoretical point of view, and the available empirical data concern a few, simple atomic species. We represent a possible dosimetric effect of the interaction with laser light, inferring from experiments the characteristics of laser-assisted cross-sections. Using a Monte-Carlo calculation for simulating the micro-dosimetric aspects of the irradiation of a simple geometry, we show the need of new experimental data and more detailed theoretical approaches to these phenomena in complex molecular systems.

Timber Auctions in the Context of the Modern Auction Theory

2007 ◽  
pp. 86-94
Author(s):  
A. Manakov
Keyword(s):  
Theoretical Analysis ◽  
Auction Theory ◽  
Point Of View ◽  
Theoretical Point ◽  
English Auction ◽  
Analysis And Evaluation

The article provides theoretical analysis and evaluation of the timber auctions reforms in Russia. The author shows that the mechanism of the "combined auctions", which functioned until recently, is more appropriate from the theoretical point of view (and from the point of view of the Russian practice) as compared to the officially approved format of the English auction.

A novel cryptosystem based on abstract automata and Latin cubes

2015 ◽  
Vol 52 (2) ◽  
pp. 221-232
Author(s):  
Pál Dömösi ◽  
Géza Horváth
Keyword(s):  
Block Cipher ◽  
Finite Automata ◽  
Theoretical Background ◽  
Point Of View ◽  
Theoretical Point ◽  
Transition Matrices ◽  
Encryption And Decryption ◽  
Secret Keys ◽  
Automata Network ◽  
Fully Functioning

In this paper we introduce a novel block cipher based on the composition of abstract finite automata and Latin cubes. For information encryption and decryption the apparatus uses the same secret keys, which consist of key-automata based on composition of abstract finite automata such that the transition matrices of the component automata form Latin cubes. The aim of the paper is to show the essence of our algorithms not only for specialists working in compositions of abstract automata but also for all researchers interested in cryptosystems. Therefore, automata theoretical background of our results is not emphasized. The introduced cryptosystem is important also from a theoretical point of view, because it is the first fully functioning block cipher based on automata network.

Graffiti als Version und Subversion–Praxen kultureller Re-Regulierung und die Möglichkeit von Gratiforschung

2010 ◽  
Vol 55 (2) ◽  
pp. 11-25 ◽  
Author(s):  
Bernd Dollinger
Keyword(s):  
Social Life ◽  
Point Of View ◽  
Theoretical Point ◽  
Research Practice ◽  
Wird Eine ◽  
Multiple Perspectives

Der Beitrag geht von Versuchen aus, integrative Perspektiven einer überaus heterogenen Graffitiforschung zu bestimmen. In Auseinandersetzung insbesondere mit Bruno Latours Ansatz des »Iconoclash« wird eine kulturtheoretische Referenz bestimmt, die Graffiti als Version identifiziert, d. h. als semiotisch orientierte Veränderung räumlich situierter Ordnungs- und Regulierungspraxen. Ihnen kann, wenn auch nicht zwingend, eine subversive Qualität zukommen. Durch die Ausrichtung am Konzept einer Version wird beansprucht, Forderungen einer normativ weitgehend abstinenten, nicht-essentialistischen und für komplexe Fragen der Identitäts- und Raumpolitik offenen Forschungspraxis einzulösen.<br><br>The contribution attempts to integrate multiple perspectives of current largely heterogeneous graffiti scholarship. Referring to Bruno Latour’s concept »iconoclash«, we discuss graffiti from a cultural-theoretical point of view as a »version«. It appears as a semiotically oriented modification of spatially situated practices that regulate social life. Often, but not necessarily, these practices involve subversive qualities. The concept of »version« facilitates a non-normative and non-essentialist strategy of research. This enables an explorative research practice in which the complex matters of identity and space politics that are associated with graffiti can be addressed.

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