scholarly journals Dynamics & Spectroscopy with Neutrons—Recent Developments & Emerging Opportunities

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1440
Author(s):  
Kacper Drużbicki ◽  
Mattia Gaboardi ◽  
Felix Fernandez-Alonso

This work provides an up-to-date overview of recent developments in neutron spectroscopic techniques and associated computational tools to interrogate the structural properties and dynamical behavior of complex and disordered materials, with a focus on those of a soft and polymeric nature. These have and continue to pave the way for new scientific opportunities simply thought unthinkable not so long ago, and have particularly benefited from advances in high-resolution, broadband techniques spanning energy transfers from the meV to the eV. Topical areas include the identification and robust assignment of low-energy modes underpinning functionality in soft solids and supramolecular frameworks, or the quantification in the laboratory of hitherto unexplored nuclear quantum effects dictating thermodynamic properties. In addition to novel classes of materials, we also discuss recent discoveries around water and its phase diagram, which continue to surprise us. All throughout, emphasis is placed on linking these ongoing and exciting experimental and computational developments to specific scientific questions in the context of the discovery of new materials for sustainable technologies.

Author(s):  
John C. Steuben ◽  
Athanasios P. Iliopoulos ◽  
John G. Michopoulos

Recent years have seen a sharp increase in the development and usage of Additive Manufacturing (AM) technologies for a broad range of scientific and industrial purposes. The drastic microstructural differences between materials produced via AM and conventional methods has motivated the development of computational tools that model and simulate AM processes in order to facilitate their control for the purpose of optimizing the desired outcomes. This paper discusses recent advances in the continuing development of the Multiphysics Discrete Element Method (MDEM) for the simulation of AM processes. This particle-based method elegantly encapsulates the relevant physics of powder-based AM processes. In particular, the enrichment of the underlying constitutive behaviors to include thermoplasticity is discussed, as are methodologies for modeling the melting and re-solidification of the feedstock materials. Algorithmic improvements that increase computational performance are also discussed. The MDEM is demonstrated to enable the simulation of the additive manufacture of macro-scale components. Concluding remarks are given on the tasks required for the future development of the MDEM, and the topic of experimental validation is also discussed.


2021 ◽  
Vol 2042 (1) ◽  
pp. 012116
Author(s):  
Pierson Clotilde ◽  
Soto Magán Victoria Eugenia ◽  
Aarts Mariëlle ◽  
Andersen Marilyne

Abstract Recent developments in the lighting research field have demonstrated the importance of a proper exposure to light to mediate several of our behavioral and physiological responses. However, we spend nowadays around 90% of our time indoors with an often quite limited access to bright daylight. To be able to anticipate how much the built environment actually influences our light exposure, and how much it may ultimately impact our health, well-being, and productivity, new computational tools are needed. In this paper, we present a first attempt at a simulation workflow that integrates a spectral simulation tool with a light-driven prediction model of alertness. The goal is to optimize the effects of light on building occupants, by informing the decision makers about the impact of different design choices. The workflow is applied to a case study to provide an example of what learnings can be expected from it.


Entropy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 244
Author(s):  
Nicolás Pérez ◽  
Constantin Wolf ◽  
Alexander Kunzmann ◽  
Jens Freudenberger ◽  
Maria Krautz ◽  
...  

The entropy of conduction electrons was evaluated utilizing the thermodynamic definition of the Seebeck coefficient as a tool. This analysis was applied to two different kinds of scientific questions that can—if at all—be only partially addressed by other methods. These are the field-dependence of meta-magnetic phase transitions and the electronic structure in strongly disordered materials, such as alloys. We showed that the electronic entropy change in meta-magnetic transitions is not constant with the applied magnetic field, as is usually assumed. Furthermore, we traced the evolution of the electronic entropy with respect to the chemical composition of an alloy series. Insights about the strength and kind of interactions appearing in the exemplary materials can be identified in the experiments.


Author(s):  
Harry Bunt

This chapter presents a characterisation of the field of computational pragmatics, discusses some of the fundamental issues in the field, and provides a survey of recent developments. Central to computational pragmatics is the development and use of computational tools and models for studying the relations between utterances and their context of use. Essential for understanding these relations are the use of inference and the description of language use as actions inspired by the context, and intended to influence the context. The chapter therefore focuses on recent work in the use of inference for utterance interpretation and in dialogue modeling in terms of dialogue acts, viewed as context-changing actions. The chapter concludes with a survey of recent activities concerning the construction and use of resources in computational pragmatics, in particular annotation schemes, annotated corpora, and tools for corpus construction and use.


2019 ◽  
Vol 23 (10) ◽  
pp. 110
Author(s):  
Ibraheem Nadher Ibraheem

The recent developments in the field of artificial intelligence to the emergence of expert systems, and computational tools designed to capture and access to knowledge from experts in the medical field. We have built an expert system for the purpose of giving the diagnosis of some diseases by linking this system devise testing and analysis of blood type (CELL-DYN Ruby) and which has a private entrance to the computer. The system is divided into several modules, History Entering Module (HEM) systematic Review Module (SRM), a Laboratory Test List Module, Diagnosis Process Module (DPM), Data Base (DB), and finally the graphical interface to the user. All these modules work together to give a high degree of accuracy in the diagnosis of disease through blood samples and we will describe the work of each unit in detail.   http://dx.doi.org/10.25130/tjps.23.2018.179    


2021 ◽  
Author(s):  
Lukas Landler ◽  
Graeme D. Ruxton ◽  
E. Pascal Malkemper

Abstract A broad range of scientific studies involve taking measurements on a circular rather than linear scale (often times or orientations). For linear measures there is a well-established statistical toolkit based on linear modelling to explore the associations between this focal variable and potentially several explanatory factors and covariates. However, most statistical testing of circular statistics is much simpler: often involving either testing whether variation in the focal measurements departs from circular uniformity, or whether a single explanatory factor with two levels is supported. Here we demonstrate that a MANOVA approach based on the sines and cosines of the circular data is as effective as the most-commonly used tests in these simple situations, while additionally it offers extension to multi-factorial modelling that these conventional tests do not. This, in combination with recent developments in Bayesian approaches, offers a substantial broadening of the scientific questions that can be addressed statistically with circular data.


Author(s):  
Ignacio Díaz ◽  
Abel A. Cuadrado ◽  
Alberto B. Diez ◽  
Manuel Domínguez ◽  
Juan J. Fuertes ◽  
...  

The objective of this chapter is to present, in a comprehensive and unified way, a corpus of data and knowledge visualization techniques based on the Self-Organizing Map (SOM). These techniques allow exploring the behavior of the process in a visual and intuitive way through the integration of existing process-related knowledge with information extracted from data, providing new ways for knowledge discovery. With a special focus on the application to process supervision and modeling, the chapter reviews well known techniques –such as component planes, u-matrix, and projection of the process state– but also presents recent developments for visualizing process-related knowledge, such as fuzzy maps, local correlation maps, and model maps. It also introduces the maps of dynamics, which allow users to visualize the dynamical behavior of the process on a local model basis, in a seamless integration with the former visualizations, making it possible to confront all them for discovery of new knowledge.


2006 ◽  
Vol 78 (8) ◽  
pp. vi
Author(s):  
V. Vlachy ◽  
M. Bešter-Rogač

Chemical and physical processes in biological systems take place in an aqueous environment, and understanding of the properties of solutions is of major importance for advancements in science. Similarly, this holds true for many technologies, where solutions and liquids are in contact with various materials. All this makes the chemistry and physics of solutions one of the most important topics of physical chemistry.The advancements in this area of science are reviewed every second year through the series of world conferences under the title International Conference on Solution Chemistry (ICSC).The 29th International Conference on Solution Chemistry sponsored by IUPAC was held in Portorož, Slovenia, 20-25 August 2005. The conference was organized by the faculty of chemistry and chemical technology at the University of Ljubljana, Slovenia. The ICSC has been held biannually since 1967 and under the present name since 1988. The meetings, which have been held in locations ranging from Debrecen (Hungary) to Vaals (Netherlands) and from Fukuoka (Japan) to Vichy (France), are organized by a 10-member international steering committee. The present chairperson of the committee is Prof. Ingmar Persson from the University of Uppsala in Sweden. Altogether, the 29th ICSC hosted almost 300 participants from 36 countries, including approximately 50 Ph.D. students who took advantage of the conference's reduced fees for students, and more than 40 accompanying family members.The theme of the conference was "the chemistry of solutions", but sessions were also held on supramolecular assemblies and nanostructures, interfaces, biophysical and pharmaceutical problems, aquatic chemistry, ionic liquids, and others. An array of eminent scientists from around the world gave plenary presentations and keynote lectures, and a broad spectrum of the research is reflected in the selection of papers presented in this issue.The first contribution entitled "Reactive intermediates in aqueous ozone decomposition: A mechanistic approach", by Fábián István (University of Debrecen, Debrecen, Hungary) provides a detailed account of recent developments in mechanistic interpretation of aqueous ozone decomposition. Experimental complications with collecting reliable kinetic information for this system are illustrated via selected examples. It is also demonstrated how a complex kinetic model can be validated by studying the system under the specific experimental conditions.Ion-pairing is a classic topic of electrochemistry, and powerful tools such as the spectroscopic techniques UV/vis, NMR, and Raman are often used for the investigation of chemical speciation in solution. However, it is not widely recognized that such techniques do not always provide reliable information about ion association equilibria. Recent developments in this area of research are reviewed by Glenn Hefter (Murdoch University, Perth, Australia). In the paper entitled "When spectroscopy fails: The measurement of ion pairing", data are presented for metal ion/sulfate systems in aqueous solution that demonstrate the inadequacy of the major spectroscopic techniques for the investigation of systems that involve non-contact ion pairs.The next contribution, "Ionic liquids: A most promising research field in solution chemistry and thermodynamics", written by Andreas Heintz and Christiane Wertz (University of Rostock, Rostock, Germany), reviews current research in the field of room-temperature ionic liquids. This topic had a special place at the conference - the round-table discussion about theory and application of these systems, sponsored by Merck KGaA Darmstadt and chaired by Prof. A. Heintz. In the present paper, several selected examples of the most promising chemical and technical applications of ionic liquids are presented, underlining the importance of thermophysical properties of ionic liquids and their role in catalytic and separation processes.Solvation steric effect plays a decisive role in reaction thermodynamics and kinetics of the metal ions. This topic is analyzed by Shin-Ichi Ishiguro and his coworkers from Kyushu University in Fukuoka, Japan in a study entitled "Solvent conformation and ion solvation: From molecular to ionic liquids". The authors discuss their recent results on solvation steric effects in view of structure and thermodynamics, particularly, the conformational change of solvents and their effect on the metal-ion complexation.Electrolyte solutions play major roles in nature and in technological processes, yet the understanding of their properties and interaction with other materials is far from being complete. On the contrary, the ion specific effects, experimentally determined more than 100 years ago, are still largely unexplained. Toward this end, the paper "Specific ion effects in liquids, in biological systems, and at interfaces" by Werner Kunz (University of Regensburg, Regensburg, Germany) reviews the present knowledge of ion effects in solutions, at interfaces, and in complex colloidal systems. Some important experiments and theoretical approaches are discussed, and references of most important papers are provided.V. Vlachy and M. Bešter-RogačConference Editors


1997 ◽  
Vol 04 (02) ◽  
pp. 343-352 ◽  
Author(s):  
MAURIZIO SACCHI

A short overview is given of recent developments in the use of polarized X-rays. A few studies are chosen to exemplify the possible applications and the common underlying ideas of different spectroscopic techniques in the domain of soft X-rays. The analysis of resonant reflectivity of polarized X-rays from a magnetic sample is discussed in more detail.


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