Molecular properties via a subsystem density functional theory formulation: A common framework for electronic embedding

In this article, we present a consistent derivation of a density functional theory (DFT) based embedding method which encompasses wave-function theory-in-DFT (WFT-in-DFT) and the DFT-based subsystem formulation of response theory (DFT-in-DFT) by Neugebauer [J. Neugebauer, J. Chem. Phys. 131, 084104 (2009)10.1063/1.3212883] as special cases. This formulation, which is based on the time-averaged quasi-energy formalism, makes use of the variation Lagrangian techniques to allow the use of non-variational (in particular: coupled cluster) wave-function-based methods. We show how, in the time-independent limit, we naturally obtain expressions for the ground-state DFT-in-DFT and WFT-in-DFT embedding via a local potential. We furthermore provide working equations for the special case in which coupled cluster theory is used to obtain the density and excitation energies of the active subsystem. A sample application is given to demonstrate the method. © 2012 American Institute of Physics

Observation of Replica Symmetry Breaking in the 1D Anderson Localization Regime in an Erbium-Doped Random Fiber Laser

The analogue of the paramagnetic to spin-glass phase transition in disordered magnetic systems, leading to the phenomenon of replica symmetry breaking, has been recently demonstrated in a two-dimensional random laser consisting of an organic-based amorphous solid-state thin film. We report here the first demonstration of replica symmetry breaking in a one-dimensional photonic system consisting of an erbium-doped random fiber laser operating in the continuous-wave regime based on a unique random fiber grating system, which plays the role of the random scatterers and operates in the Anderson localization regime. The clear transition from a photonic paramagnetic to a photonic spin glass phase, characterized by the probability distribution function of the Parisi overlap, was verified and characterized. In this unique system, the radiation field interacts only with the gain medium, and the fiber grating, which provides the disordered feedback mechanism, does not interfere with the pump

Leveraging the promotion of tourist destinations and the interpretation of their heritage using virtual reality

Technology is increasingly a transversal layer to all activities and, in this sense, exploring the potential of technology as a driver to support the competitiveness of organizations and nations has become a necessity for survival. Tourism is a fundamental asset in many modern economies and certainly fundamental from a civilizational and generational point of view, insofar as associated with a wide range of tourist destinations is its heritage. As such, the promotion and interpretation of destinations and their heritage are very important and, in these areas, technologies have played a fundamental and revolutionary role. In this scenario, Virtual Reality, among other technologies, demonstrates a vast potential in promoting tourist destinations and in creating immersive experiences that allow for a better interpretation of destinations and their heritage, as well as greater attractiveness for younger generations. This article, after a review of technological concepts and a discussion of their role in the context of tourism and heritage, proposes a conceptual model capable of contributing to a more agile and massified creation of Virtual Reality experiences. Finally, an experimental prototype created for an olive and olive-oil museum is presented, with the aim of facilitating the interpretation, by visitors, of its permanent exhibition objects and improving the visiting experience.info:eu-repo/semantics/publishedVersio

Crystal structures of three 6-substituted coumarin-3-carboxamide derivatives

Three coumarin derivatives, viz. 6-methyl-N-(3-methyl-phen-yl)-2-oxo-2H-chromene-3-carboxamide, C18H15NO3 (1), N-(3-meth-oxy-phen-yl)-6-methyl-2-oxo-2H-chromene-3-carboxamide, C18H15NO4 (2), and 6-meth-oxy-N-(3-meth-oxy-phen-yl)-2-oxo-2H-chromene-3-carboxamide, C18H15NO5 (3), were synthesized and structurally characterized. The mol-ecules display intra-molecular N-H⋯O and weak C-H⋯O hydrogen bonds, which probably contribute to the approximate planarity of the mol-ecules. The supra-molecular structures feature C-H⋯O hydrogen bonds and π-π inter-actions, as confirmed by Hirshfeld surface analyses.info:eu-repo/semantics/publishedVersio

Data Mining Technique for Preventional Analysis of Work Accidents

There are many oil companies operating in Macaé-RJ, Campos basin, they value the safety of work and the lives of its employees. These companies do a study to verify the health status of their employees' spine and result in a database with six attributes, such as: Pelvic incidence, Pelvic inclination, Lumbar lordosis angle, Sacral inclination, Pelvic radius and Degree of Spondylolisthesis. For in Brazil, recently, Social Security has released statistical studies that show back pain as leaders in the ranking of departures in the first half of 2016, a fact that directly affects the productivity of companies and health of their employees. This article aims to apply the KDD process, specifically the task of Data Mining classification, ie, classify if the employee will be fit or unfit for the job. The decision tree was the technique chosen through the algorithm J48 to verify the possibilities of treatment of the collaborators in the prevention and improvement in the working environment, and even, a change in the management was made from the results found. It resulted in inadequate staff postures, inadequate service stations, lack of training in equipment handling, lack of knowledge about cargo handling

Novel insights into biomass delignification with acidic deep eutectic solvents: a mechanistic study of β-O-4 ether bond cleavage and the role of the halide counterion in the catalytic performance

The development of innovative technologies for an efficient, yet eco-friendly, biomass delignification is required to achieve higher sustainability than traditional processes. In this context, the use of deep eutectic solvents (DES) for the delignification process could fulfil these requirements and stands today as a promising alternative. This work focus on understanding the fundamental chemistry behind the cleavage of B-O-4 ether bond present in 2-phenoxy-1-phenylethanol (PPE), a lignin model compound, with three acidic DES, including Propionic acid/Urea (PA:U), Lactic acid/Choline Chloride (LA:ChCl) and p-Toluenesulphonic acid/Choline chloride (pTSA:ChCl). The acidic nature of each DES influenced the efficiency of PPE cleavage and determined the extent of further side reactions of cleavage products. Although PA:U (2:1) demonstrated ability to dissolve lignin, it is unable to cleave B-O-4 ether linkage in PPE. On the other hand, LA:ChCl (10:1) allowed PPE cleavage, but an esterification between the PPE and lactic acid as well as oligomerization of lactic acid were detected. Among examined solvents, pTSA:ChCl (1:1) demonstrated the highest performance on the PPE cleavage, although the high acidity of this system lead to condensation of cleavage products at prolonged time. The presence of water decreases the ability of DES for the cleavage, but the extension of undesired side reactions was also reduced. Finally, the analysis of intermediates and products of the reactions allowed the identification of a chlorinated species of PPE that precedes the cleavage reaction. A kinetic study using pTSA:ChCl (1:1) and pTSA:ChBr (1:1) was performed to unveil the role of the halide counterion present in DES on the cleavage of <2=2 ether bond and a new reaction mechanism was herein proposed and supported by density functional theory (DFT) calculations.Altri ñ Celbi, Buckman, Crown Van Gelder, CTP, DS Smith Paper, ESKA, Essity, Holmen, ISPT, Mayr-Melnhof Eerbeek, Mets‰ Fibre, Mid Sweden University, Mondi, Omya, The Navigator Company, Sappi, Essity, Smurfit Kappa, Stora Enso, Eindhoven University of Technology, University of Aveiro, University of Twente, UPM, Valmet Technologies Oy, Voith Paper, VTT Technical Research Centre of Finland Ltd, WEPA and Zellstoff Pols.in publicatio

Environmental effects with Frozen Density Embedding in Real-Time Time-Dependent Density Functional Theory using localized basis functions

Frozen Density Embedding (FDE) represents a versatile embedding scheme to describe the environmental effect on the electron dynamics in molecular systems. The extension of the general theory of FDE to the real-time time-dependent Kohn-Sham method has previously been presented and implemented in plane-waves and periodic boundary conditions (Pavanello et al. J. Chem. Phys. 142, 154116, 2015). In the current paper, we extend our recent formulation of real-time time-dependent Kohn-Sham method based on localized basis set functions and developed within the Psi4NumPy framework (De Santis et al. J. Chem. Theory Comput. 2020, 16, 2410) to the FDE scheme. The latter has been implemented in its "uncoupled" flavor (in which the time evolution is only carried out for the active subsystem, while the environment subsystems remain at their ground state), using and adapting the FDE implementation already available in the PyEmbed module of the scripting framework PyADF. The implementation was facilitated by the fact that both Psi4NumPy and PyADF, being native Python API, provided an ideal framework of development using the Python advantages in terms of code readability and reusability. We demonstrate that the inclusion of the FDE potential does not introduce any numerical instability in time propagation of the density matrix of the active subsystem and in the limit of weak external field, the numerical results for low-lying transition energies are consistent with those obtained using the reference FDE calculations based on the linear response TDDFT. The method is found to give stable numerical results also in the presence of strong external field inducing non-linear effects

Techniques for the execution profile analysis and optimization of computational chemistry programs

In this paper we review the basic techniques of performance analysis within the UNIX environment that are relevant in computational chemistry, with particular emphasis on the execution profile using the gprof tool. Two case studies (in ab initio and molecular dynamics calculations) are presented in order to illustrate how execution profiling can be used to effectively identify bottlenecks and to guide source code optimization. Using these profiling and optimization techniques it was possible to obtain significant speedups (of up to 30%) in both cases.465469Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Stress and coping in sport

O estresse é entendido como um desequilíbrio substancial entre uma demanda e a capacidade de resposta, sob condições em que a falha em satisfazer a exigência tem consequências significativas. No esporte, esse assunto tem sido alvo de estudos a mais de quarenta anos, con- tudo, ainda há muito o que se entender sobre esse complexo tema. Assim, o objetivo dessa pesquisa foi realizar uma revisão sistemática de literatura sobre o estresse e coping no esporte, identificando as principais teorias, suas evoluções ao longo dos anos e as formas efi- cientes de investigação. Para a análise, consultamos as bases de da- dos: Google® acadêmico, Science Direct e Scielo, buscando por livros, teses, dissertações e artigos relacionados ao tema. Como resultados, destacamos o estudo de Balbinotti et al. (2013) que propôs uma nova classificação de coping, e o Modelo Transacional Cognitivo, Motivacio- nal e Relacional (Lazarus, 1991; Lazarus & Folkman, 1984), que verifica o processo de adaptação dos atletas ao contexto esportivo. Fletcher e Fletcher (2005) e Gomes (2014) também contribuíram para o desen- volvimento do Modelo de Lazarus, considerando as emoções presen- tes ao fim do processo cognitivo.Stress is seen as a substantal imbalance between demand and responsiveness, under conditons where failure to meet the requirement has signifcant consequences. In sports, this issue has been investgated over forty years, however, there is stll much to understand about this complex topic. This research aimed to conduct a systematc review of literature on stress and coping in sport, identfying the main theories, their evoluton over the years and the efcient forms of research. For the analysis, we consulted the databases: Academic Google®, Science Direct and Scielo, searching for books, theses, dissertatons and papers related to the topic. As result, we highlight the study Balbinot et al. (2013) who proposed a new classifcaton of coping, and the Transactonal Stress Model (Lazarus, 1991, Lazarus & Folkman, 1984), which verifes the process of adaptaton of athletes to the sportng context. Fletcher and Fletcher (2005) and Gomes (2014) also contributed to the development of Lazarus Model in an emoton perspectve.info:eu-repo/semantics/publishedVersio