Resonance energy transfer and interface forces:Quantum electrodynamical analysis

On the propagation of radiation with a suitably resonant optical frequency through a dense chromophoric system - a doped solid for example - photon capture is commonly followed by one or more near-field transfers of the resulting optical excitation, usually to closely neighboring chromophores. Since the process results in a change to the local electronic environment, it can be expected to also shift the electromagnetic interactions between the participant optical units, producing modified inter-particle forces. Significantly, it emerges that energy transfer, when it occurs between chromophores or particles with electronically dissimilar properties (such as differing polarizabilities), engenders hitherto unreported changes in the local potential energy landscape. This paper reports the results of quantum electrodynamical calculations which cast a new light on the physical link between these features. The theory also elucidates a significant relationship with Casimir-Polder forces; it transpires that there are clear and fundamental links between dispersion forces and resonance energy transfer. Based on the results, we highlight specific effects that can be anticipated when laser light propagates through an interface between two absorbing media. Both steady-state and pulsed excitation conditions are modeled and the consequences for interface forces are subjected to detailed analysis

Ultra High Resolution Transmission Electron Microscopy of Matrix Mineral Grains in CM Chondrites: Preaccretionary or Parent Body Aqueous Processing?

CM chondrites are highly hydrated meteorites associated with a parent asteroid that has experienced significant aqueous processing. The meteoritic evidence indicates that these non-differentiated asteroids are formed by fine-grained minerals embedded in a nanometric matrix that preserves chemical clues of the forming environment. So far there are two hypothesis to explain the presence of hydrated minerals in the content of CM chondrites: one is based on textural features in chondrule-rim boundaries [1-3], and the other ‘preaccretionary’ hypothesis proposes the incorporation of hydrated phases from the protoplanetary disk [4-6]. The highly porous structure of these chondrites is inherited from the diverse materials present in the protoplanetary disk environment. These bodies were presumably formed by low relative velocity encounters that led to the accretion of silicate-rich chondrules, refractory Ca- and Al-rich inclusions (CAIs), metal grains, and the fine-grained materials forming the matrix. Owing to the presence of significant terrestrial water in meteorite finds [7], here we have focused on two CM chondrite falls with minimal terrestrial processing: Murchison and Cold Bokkeveld. Anhydrous carbonaceous chondrite matrices are usually represented by highly chemically unequilibrated samples that contain distinguishable stellar grains. Other chondrites have experienced hydration and chemical homogeneization that reveal parent body processes. We have studied CM chondrites because these meteorites have experienced variable hydration levels [8-10]. It is important to study the textural effects of aqueous alteration in the main minerals to decipher which steps and environments promote bulk chemistry changes, and create the distinctive alteration products. It is thought that aqueous alteration has particularly played a key role in modifying primordial bulk chemistry, and homogenizing the isotopic content of fine-grained matrix materials [7, 11, 12]. Fortunately, the mineralogy produced by parent-body and terrestrial aqueous alteration processes is distinctive [5, 11]

Electron bifurcation mechanism and homoacetogenesis explain products yields in mixed culture anaerobic fermentations

Anaerobic fermentation of organic wastes using microbial mixed cultures is a promising avenue to treat residues and obtain added-value products. However, the process has some important limitations that prevented so far any industrial application. One of the main issues is that we are not able to predict reliably the product spectrum (i.e. the stoichiometry of the process) because the complex microbial community behaviour is not completely understood. To address this issue, in this work we propose a new metabolic network of glucose fermentation by microbial mixed cultures that incorporates electron bifurcation and homoacetogenesis. Our methodology uses NADH balances to analyse published experimental data and evaluate the new stoichiometry proposed. Our results prove for the first time the inclusion of electron bifurcation in the metabolic network as a better description of the experimental results. Homoacetogenesis has been used to explain the discrepancies between observed and theoretically predicted yields of gaseous H2 and CO2 and it appears as the best solution among other options studied. Overall, this work supports the consideration of electron bifurcation as an important biochemical mechanism in microbial mixed cultures fermentations and underlines the importance of considering homoacetogenesis when analysing anaerobic fermentations

Fish larvae from the Canary region in autumn

In this paper, the taxonomic composition of the fish larvae community in the Canary region in autumn 1991 is presented. In total, 8699 larvae belonging to 58 fish families were studied. 176 taxonomic groups were identified, 149 species level and the rest were identified at a higher level. The most numerous family and the one tat presented the greatest number of species was Myctophidae. The most frequently caught species was Cyclothone braueri. The taxonomic composition (at family level) of the fish larvae community, dominated by four mesopleagic families, was typical of oceanic regions of warm waters. The most tremarkable feature of the fish larvae community was its high specific diversity

Extending FuzAtAnalyzer to approach the management of classical negation

FuzAtAnalyzer was conceived as a Java framework which goes beyond of classical tools in formal concept analysis. Specifically, it successfully incorporated the management of uncertainty by means of methods and tools from the area of fuzzy formal concept analysis. One limitation of formal concept analysis is that they only consider the presence of properties in the objects (positive attributes) as much in fuzzy as in crisp case. In this paper, a first step in the incorporation of negations is presented. Our aim is the treatment of the absence of properties (negative attributes). Specifically, we extend the framework by including specific tools for mining knowledge combining crisp positive and negative attributes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Optimal Operation of Pipeline Transportation Systems

11th Triennial World Congress. Tallinn. Estonia. USSR. 1990This paper presents a simulator of an oil pipeline for scheduling purposes. The simulator includes an algorithm for optimizing the energy operating costs. The optimization algorithm works in two steps. The first one consists of the computation of a function that measures the estimated mininltun cost to the goal node. This computation involves the use of Bellman's optimality principle and of some heuristic rules in order to avoid the combinatorial explosion. During the second step the optinltmum trajectory is obtained with the help of the function mentioned above and using an accurate simulation of the transportation system. The simulation considers those aspects which are relevant t.o the optimization problem and takes into account the following factors: topology and topography of the network. non-linear characteristics of pumps and pipelines, variable demands of consumers, time changing prices of electrical energy and hydraulic equations throughout the system. The simulator is being used by CAMPSA (the major oil distribution company in Spain) Some results obtained with an oil pipeline system in Northern Spain are presented in the paper

Digital journalism competences. Systematic review of the scientific literature on new professional profiles of the journalist

El estudio emprende un análisis de la literatura científica que ha centrado su interés en la formación en nuevas tecnologías de los profesionales de la información. Con esa finalidad, el trabajo acota la revisión a 119 artículos indexados en las bases de datos Web of Science (54) y Scopus (65), entre 1998 y 2017. El objetivo del estudio es determinar cuáles son las competencias tecnológicas más demandadas por la industria, y cuáles son los valores inalterables del periodismo. La exploración del corpus especulativo determina el siguiente resultado: los profesionales, los empresarios y las audiencias concuerdan que la pervivencia de un periodismo de calidad depende de la integración del entorno tecnológico, el económico y el de los principios esenciales de la profesión. La discusión plantea un tema de fondo en los que investigadores debemos profundizar: cómo las universidades pueden contribuir a la mejorara el periodismo en esos tres aspectos. The study undertakes an analysis of the scientific literature that has focused its interest on the training in new technologies for information professionals. With this purpose, the work limits the review to 119 indexed articles in the Web of Science (54) and Scopus (65) from 1998 until 2017. The objective of the study is to identify what are the technological competences most demanded by the industry, and which are the inalterable values of journalism. An exploration of the speculative corpus determines the following result: the professionals, the businessmen and the audiences agree on the continuity of quality journalism depends on the integration of three environments: the technological, the economic and that of the fundamental principles of the profession. The argument raise a theme where researchers must deepen how the universities can contribute to the improvement of journalism in these three areas