Total Chiral Symmetry Breaking during Crystallization: Who needs a "Mother Crystal"?

Processes that can produce states of broken chiral symmetry are of particular interest to physics, chemistry and biology. Chiral symmetry breaking during crystallization of sodium chlorate occurs via the production of secondary crystals of the same handedness from a single "mother crystal" that seeds the solution. Here we report that a large and "symmetric" population of D- and L-crystals moves into complete chiral purity disappearing one of the enantiomers. This result shows: (i) a new symmetry breaking process incompatible with the hypothesis of a single "mother crystal"; (ii) that complete symmetry breaking and chiral purity can be achieved from an initial system with both enantiomers. These findings demand a new explanation to the process of total symmetry breaking in crystallization without the intervention of a "mother crystal" and open the debate on this fascinating phenomenon. We present arguments to show that our experimental data can been explained with a new model of "complete chiral purity induced by nonlinear autocatalysis and recycling".Comment: 5 pages, 4 figures, Added reference

Analysis of the experimental spectral coherence in the Nysted Wind Farm

In this paper, it is analysed the coherence between wind speeds located in a horizontal plane corresponding to hub height of wind turbines in a large wind farm. The coherence is calculated through real data from Nysted Offshore Wind Farm. Concretely, the wind speed measured in the 72 Wind Turbines and in 2 of the meteorological masts during 9 months. The results are analysed in the scale of power fluctuations in large offshore wind farms. This analysis shows the needing of a new spectral coherence model.The work presented in this paper has been done in the research Project ”Power Fluctuations from large offshore wind farms” financed by the Danish Transmission System Operator Energinet.dk as PSO 2004 project number 6506. A. Vigueras-Rodr´ıguez is supported by the Spanish Ministerio de Educaci´on y Ciencia through the grant program “Becas FPU” and from the national research project “ENE2006-15422-C02-02

Smoke and fire dynamics in atria and large enclosures: An overview

The proliferation of atria within modern large buildings is relatively recent. An atrium can be defined as a large open space connecting two or more storeys. Atria are important architectonical features since the 60's and can be found, among others, in shopping centres, office buildings and high-rise buildings, airports, stations and sports centres. However, the atrium represents an innovative, complex and non conventional architectonical element that can lead to fire environments diverging significantly from those in conventional compartments used in the development of current codes and standards. They are a source of discussion in the fire safety community because smoke can easily spread from one floor to another making the traditional methodologies for compartmentation of little or null effect. The design of smoke management in atria has been based on prescriptive codes since the 70's. It was not until the mid 80's that the phenomena started to be the objective of both experimental and numerical studies. It is because of the subsequent improved understanding on fire dynamics and smoke management together with the increased computing power available nowadays, that there is a progressive movement from prescriptive-based to performance-based codes which is also chaning the way atria are designed. The aim of the present work is to provide a broad overview of the current state-of-the-art of fires in atria. A brief introduction to the characteristics and types of atrium structures is presented first. Then, a description of the fire dynamics as well as the main safety problems that arise in case of fire are considered. A historical discussion of the research, including experimental and numerical studies, is presented, and current design methodologies and fire safety strategies are discussed. The final part of the overview addresses the international tendencies towards the introduction of performance-based fire protection codes. This overview highlights the need for further experimental studies and validations of numerical simulations for a wider range of fire conditions. © 2010 by Nova Science Publishers, Inc. All rights reserved

From academic to media capital: To what extent does the scientific reputation of universities translate into Wikipedia attention?

Universities face increasing demands to improve their visibility, public outreach, and online presence. There is a broad consensus that scientific reputation significantly increases the attention universities receive. However, in most cases estimates of scientific reputation are based on composite or weighted indicators and absolute positions in university rankings. In this study, we adopt a more granular approach to assessment of universities' scientific performance using a multidimensional set of indicators from the Leiden Ranking and testing their individual effects on university Wikipedia page views. We distinguish between international and local attention and find a positive association between research performance and Wikipedia attention which holds for regions and linguistic areas. Additional analysis shows that productivity, scientific impact, and international collaboration have a curvilinear effect on universities' Wikipedia attention. This finding suggests that there may be other factors than scientific reputation driving the general public's interest in universities. Our study adds to a growing stream of work which views altmetrics as tools to deepen science-society interactions rather than direct measures of impact and recognition of scientific outputs

A Bibliometric Overview of the International Journal of Interactive Multimedia and Artificial Intelligence

The International Journal of Interactive Multimedia and Artificial Intelligence (IJIMAI) published its first issue ten years ago. Currently, IJIMAI is indexed in the important database Emerging Sources Citation Index. This paper aims to identify, through a mapping of science, those most relevant aspects of the structure of publications made during the first 10 years of IJIMAI. Using VOSviewer software, the structural maps of the IJIMAI publications are analysed according to techniques such as bibliographic coupling, co-citations and cooccurrence of keywords. In addition, the evolution of the publications, citations and an analysis of the most cited papers of the journal are presented. The results show that IJIMAI has experienced a remarkable growth of both publications and citations in the last five years. We also observe that IJIMAI does not only capture the attention of the Spanish scientific community, but also of emerging countries such as India and Iran and emerging Latin American countries such as Colombia. With a such increasing behaviour, it is expected in the coming years that IJIMAI will position itself among the best journals with similar scientific scope

Using Multi-granular Fuzzy Linguistic Modelling Methods to Represent Social Networks Related Information in an Organized Way

Social networks are the preferred mean for experts to share their knowledge and provide information. Therefore, it is one of the best sources that can be used for obtaining data that can be used for a high amount of purposes. For instance, determining social needs, identifying problems, getting opinions about certain topics, ... Nevertheless, this kind of information is difficult for a computational system to interpret due to the fact that the text is presented in free form and that the information that represents is imprecise. In this paper, a novel method for extracting information from social networks and represent it in a fuzzy ontology is presented. Sentiment analysis procedures are used in order to extract information from free text. Moreover, multi-granular fuzzy linguistic modelling methods are used for converting the information into the most suitable representation mean.This work has been supported by the ’Juan de la Cierva Incorporación’ grant from the Spanish Ministry of Economy and Competitiveness and by the Grant from the FEDER funds provided by the Spanish Ministry of Economy and Competitiveness (No. TIN2016-75850-R)

Community nutrition in Spain: advances and drawbacks

Scientific evidence has placed community nutrition among the front-line strategies in health promotion. Community nutrition in different regions of Spain has developed at an unequal pace. Early initiatives in the mid 1980s provided good-quality population data and established a basis for nutrition surveillance including individual body measurements, dietary intake data, information on physical activity, and biomarkers. The Nutrition and Physical Activity for Obesity Prevention Strategy (NAOS) reinforces community nutrition action in Spain. Presented here is an overview of developments in community nutrition in Spain in recent years as well as potential trends under the scope of the NAOS.Publicad

A group decision making support system for the Web: how to work in environments with a high number of participants and alternatives

One of the main challenges that the appearance of Web 2.0 and the overall spreading of the Internet have generated is how to tackle with the high number of users and information available. This problem is also inherited by the group decision making problems that can be carried out over the Web. In this article, to solve this issue, a group decision making support system that allows the use of a high number of participants and alternatives is presented. This method allows any number of participants to join the decision making process at any time. Furthermore, they let them provide information only about a certain subset of alternatives. The high participation rate can provide enough information for the decision process to be carried out even if the participants do not provide information about all the high number of available alternatives.This paper has been developed with the financing of FEDER funds in the project TIN2016-75850-R

Chiral Crystal Growth under Grinding

To study the establishment of homochirality observed in the crystal growth experiment of chiral molecules from a solution under grinding, we extend the lattice gas model of crystal growth as follows. A lattice site can be occupied by a chiral molecule in R or S form, or can be empty. Molecules form homoclusters by nearest neighbor bonds. They change their chirality if they are isolated monomers in the solution. Grinding is incorporated by cutting and shafling the system randomly. It is shown that Ostwald ripening without grinding is extremely slow to select chirality, if possible. Grinding alone also cannot achieve chirality selection. For the accomplishment of homochirality, we need an enhanced chirality change on crystalline surface. With this "autocatalytic effect" and the recycling of monomers due to rinding, an exponential increase of crystal enantiomeric excess to homochiral state is realized.Comment: 10 pages, 5 figure

Homochirality and the need of energy

The mechanisms for explaining how a stable asymmetric chemical system can be formed from a symmetric chemical system, in the absence of any asymmetric influence other than statistical fluctuations, have been developed during the last decades, focusing on the non-linear kinetic aspects. Besides the absolute necessity of self-amplification processes, the importance of energetic aspects is often underestimated. Going down to the most fundamental aspects, the distinction between a single object -- that can be intrinsically asymmetric -- and a collection of objects -- whose racemic state is the more stable one -- must be emphasized. A system of strongly interacting objects can be described as one single object retaining its individuality and a single asymmetry; weakly or non-interacting objects keep their own individuality, and are prone to racemize towards the equilibrium state. In the presence of energy fluxes, systems can be maintained in an asymmetric non-equilibrium steady-state. Such dynamical systems can retain their asymmetry for times longer than their racemization time.Comment: 8 pages, 7 figures, submitted to Origins of Life and Evolution of Biosphere