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.

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 Photoluminescent Coordination Polymers Based on Group 12 Metals and 1H-Indazole-6-Carboxylic Acid

Inorganics ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 20
Author(s):  
Antonio A. García-Valdivia ◽  
Estitxu Echenique-Errandonea ◽  
Gloria B. Ramírez-Rodríguez ◽  
José M. Delgado-López ◽  
Belén Fernández ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Coordination Polymers ◽  
Density Functional ◽  
Free Ligand ◽  
Emission Spectra ◽  
Point Of View ◽  
Theoretical Point ◽  
Fourier Transformed Infrared Spectroscopy ◽  
3D Network ◽  
The Stability

Two new coordination polymers (CPs) based on Zn(II) and Cd(II) and 1H-indazole-6-carboxylic acid (H2L) of general formulae [Zn(L)(H2O)]n (1) and [Cd2(HL)4]n (2) have been synthesized and fully characterized by elemental analyses, Fourier transformed infrared spectroscopy and single crystal X-ray diffraction. The results indicate that compound 1 possesses double chains in its structure whereas 2 exhibits a 3D network. The intermolecular interactions, including hydrogen bonds, C–H···π and π···π stacking interactions, stabilize both crystal structures. Photoluminescence (PL) properties have shown that compounds 1 and 2 present similar emission spectra compared to the free-ligand. The emission spectra are also studied from the theoretical point of view by means of time-dependent density-functional theory (TD-DFT) calculations to confirm that ligand-centred π-π* electronic transitions govern emission of compound 1 and 2. Finally, the PL properties are also studied in aqueous solution to explore the stability and emission capacity of the compounds.

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 Impact of Hydrogen Injection on Natural Gas Measurement

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8461
Author(s):  
Marco Dell’Isola ◽  
Giorgio Ficco ◽  
Linda Moretti ◽  
Jacek Jaworski ◽  
Paweł Kułaga ◽  
...  
Keyword(s):  
Natural Gas ◽  
Thermodynamic Properties ◽  
Calorific Value ◽  
Experimental Tests ◽  
Point Of View ◽  
Experimental Point ◽  
Theoretical Point ◽  
Primary Role ◽  
Gas Measurements ◽  
The Impact

Hydrogen is increasingly receiving a primary role as an energy vector in ensuring the achievement of the European decarbonization goals by 2050. In fact, Hydrogen could be produced also by electrolysis of water using renewable sources, such as photovoltaic and wind power, being able to perform the energy storage function, as well as through injection into natural gas infrastructures. However, hydrogen injection directly impacts thermodynamic properties of the gas itself, such as density, calorific value, Wobbe index, sound speed, etc. Consequently, this practice leads to changes in metrological behavior, especially in terms of volume and gas quality measurements. In this paper, the authors present an overview on the impact of hydrogen injection in natural gas measurements. In particular, the changes in thermodynamic properties of the gas mixtures with different H2 contents have been evaluated and the effects on the accuracy of volume conversion at standard conditions have been investigated both on the theoretical point of view and experimentally. To this end, the authors present and discuss the effect of H2 injection in gas networks on static ultrasonic domestic gas meters, both from a theoretical and an experimental point of view. Experimental tests demonstrated that ultrasonic gas meters are not significantly affected by H2 injection up to about 10%.

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 Inclusive neutrino-nucleus reaction cross sections at intermediate energies

2020 ◽  
Vol 5 ◽  
pp. 29
Author(s):  
T. S. Kosmas ◽  
E. Oset
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Reaction Cross ◽  
Point Of View ◽  
Electron Neutrino ◽  
Muon Capture ◽  
Light Nuclei ◽  
Experimental Point ◽  
Intermediate Energies ◽  
Reaction Cross Sections

Inclusive neutrino-nucleus reaction cross sections at intermediate energies (20 MeV < Ey < 500 MeV) are calculated throughout the periodic table for the most interesting nu­ clei from an experimental point of view. The method used had previously proved to be very accurate in calculating the induced reaction cross section for T=0 light nuclei (12C and 16O) and in the study of other similar processes like the ordinary muon capture. The electron-neutrino (ve) cross section weighted by the Michel distribution is also discussed in conjuction with the existing experimental results at LAMPF and ΚARMEN.

scholarly journals Neutrino - Nucleus Reaction Cross Sections at Low and Intermediate Energies

2020 ◽  
Vol 6 ◽  
pp. 100
Author(s):  
T. S. Kosmas ◽  
E. Oset
Keyword(s):  
Cross Sections ◽  
Local Density ◽  
Reaction Cross ◽  
Point Of View ◽  
Experimental Point ◽  
Density Approximation ◽  
Intermediate Energies ◽  
Inclusive Processes ◽  
Reaction Cross Sections ◽  
Lindhard Function

Neutrino-nucleus reactions at low and intermediate energies up to Ev=500 MeV are investigated for the most interesting nuclei from an experimental point of view. We mainly focus on calculations of neutrino-nucleus cross sections for semi-inclusive processes, for which recent measurements from radiochemical experiments at LAMPF and KARMEN have been obtained. Inclusive cross sections are also calculated and discussed. The method employed uses the Lindhard function for the description of the particle-hole excitations of the final nucleus via a local density approximation.

scholarly journals On broadband jet–ring interaction noise and aerofoil turbulence-interaction noise predictions

2010 ◽  
Vol 653 ◽  
pp. 337-364 ◽  
Author(s):  
MICHEL ROGER
Keyword(s):  
Transfer Function ◽  
Mixing Layer ◽  
Point Of View ◽  
Turbulent Velocity ◽  
Aerodynamic Noise ◽  
Experimental Point ◽  
Far Field ◽  
Theoretical Point ◽  
Parallel Side ◽  
Set Up

The aerodynamic noise of a thin rigid annulus (referred to as the ring here) placed in the mixing layer of a subsonic circular jet is investigated in the paper, both theoretically and experimentally. From the experimental point of view, the jet–ring configuration is understood as an axisymmetric alternative to more usual ones involving a rectangular aerofoil held between parallel side plates, dedicated to the study of the noise due to the impingement of upstream turbulence. The main advantages of the circular geometry are a minimum background noise, the absence of tip effects and more specifically the account for all radiation angles from the surface in the far-field acoustic signature. The circular set-up is well suited for the study of pure broadband interaction noise only if the flow remains free of self-sustained oscillations. This is ensured by keeping a sufficient interaction distance between the nozzle and the ring, and by shaping serrations on the nozzle lip. From the theoretical point of view, an analytical model is derived as a straightforward extension of existing formulations. The induced unsteady lift forces on the ring are first inferred from a linearized unsteady aerodynamic theory and the far field is calculated in a second step by a radiation integral. This relates the far-field acoustic pressure power spectral density (PSD) to the two-wavenumber spectrum of the radial turbulent velocity at the ring location, by means of an aeroacoustic transfer function. The latter is shown asymptotically identical to the one detailed in the Appendix for a rectangular aerofoil, in the limit of relatively high frequencies. The analytical acoustic predictions are found to agree well with the measurements over an extended frequency range, provided that the model is fed with turbulent velocity input data measured by a hot-wire probe. Indirectly, this agreement validates the transfer function for a rectangular aerofoil at oblique radiation angles, which is not achievable in a set-up involving side plates and a rectangular nozzle.

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>

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