pinecone/core-2020-05-10-deduplication huggingface dataset:
An oriented-design simplified model for the efficiency of a flat plate solar air collector

In systems design, suitably adapted physical models are required. Different modelling approaches for a solar air collector were studied in this paper. First, a classical model was produced, based on a linearization of the conservation of energy equations. Its resolution used traditional matrix methods. In order to improve the possibilities for use in design, the behaviour of the collector was next expressed in terms of efficiency. Lastly, simplified models constructed from the results obtained with the classical linearized model, and explicitly including the design variables of the collector, were proposed. These reduced models were then evaluated in terms of Parsimony, Exactness, Precision and Specialisation (PEPS). It was concluded that one of them (D2), using a low number of variables and of equations, is well suited for the design of solar air collector coupled with other sub-systems in more complex devices such as solar kiln with energy storag
Genetic Structure and Origin of Peopling in The Azores Islands (Portugal): The View from mtDNA

The Azores islands (Portugal), uninhabited when discovered by Portuguese navigators in the fifteenth century, are located in the Atlantic Ocean 1500 km from the European mainland. The archipelago is formed by nine islands of volcanic origin that define three geographical groups: Eastern (S. Miguel and Sta. Maria), Central (Terceira, Faial, Pico, Graciosa and S. Jorge) and Western (Flores and Corvo). To improve the genetic characterisation of the Azorean population, and to clarify some aspects related to the history of settlement, a study of mtDNA was conducted in the population of the archipelago. The HVRI region was sequenced and specific RFLPs were screened in 146 samples obtained from unrelated individuals with Azorean ancestry (50 from the Eastern group, 60 from the Central group, and 37 from the Western group). Samples were classified into haplogroups based on the information obtained from both sequencing and RFLP analysis. All the analyses performed support the idea that, in the whole group of islands, the majority of mtDNA lineages originated from the Iberian Peninsula, mainly from Portugal (mainland). However contributions from other European populations, especially from Northern Europe, cannot be disregarded. The values obtained for the various diversity parameters in the Azores archipelago indicate that the Azorean population, as a whole, does not exhibit the typical characteristics of an isolated population. The analysis of genetic data by groups of islands showed that the Western group exhibited particular features. The distribution of haplogroups in the Western group is very atypical, being significantly different from what is observed in the Eastern and Central groups. Furthermore, the diversity values are, in general, lower than those observed in other populations used for comparison. African haplogroups were found in all the groups of islands. Therefore the presence of Moorish and African slaves on the islands, as reported in historical sources, is supported by the mtDNA genetic data, especially in the Eastern group. The presence of Jews in the Central group is also supported by the mtDNA data. Neither historical nor genetic data (phylogeography of mtDNA) supports the idea of a differential settlement history for the Western group; however, it is represented in the phylogenies as an isolated branch. The effect of genetic drift, induced by the reduced population size since peopling occurred, has led to a very atypical distribution of haplogroups/haplotypes in this group of islands. We cannot ignore the influence of biodemographic and genetic processes, namely founder effect, genetic drift, migration, and even recent mutational events in the mtDNA lineages of the Azorean populations. Nevertheless, a great part of the variation in the Azorean mtDNA can be explained by the settlement history.http://dx.doi.org/10.1046/j.1469-1809.2003.00031.
Influence of heat treatment on the corrosion of high speed steel

The corrosion behaviour of M2 high speed steel, as-received as well as heat-treated under different conditions, has been studied in 0.1 M KCl aqueous solution by corrosion potential measurements, Tafel curves and electrochemical impedance. Heat treatment leads to an increase of the corrosion resistance of high speed steel; the higher the tempering temperature after quenching, the higher the corrosion resistance of the steel. X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy were also used to further understand the corrosion behaviour of the different samples. Based on these analyses, the microstructure of the different samples was correlated with their corrosion properties.http://dx.doi.org/10.1023/A:100415762346
Computation of magnetic field in an actuator

Design and optimization of an actuators based on magnetostrictive technology requires computation of the magnetic field. The “MS”-technology offers an attractive controllability with high power density. The magnetostriction is a reversible feature which can be used in various actuator layouts. The actuator performance depends on driving magnetic field and the particular magnetic  properties of used materials. Good understanding of specific design constrains is required to define and to optimized a magnetostrictive actuator. The non-linear computation of the magnetic field using FEM software is vital for the finale experimental design of a low-frequency actuator. This paper presents results of magnetic field simulation with FEMM software package and experimental measurements of the magnetic flux density. Good correlation between the simulation results and experimental measurements has been achieved
Discrete dislocation dynamics analysis of the effect of lattice orientation on void growth in single crystals

The micromechanisms of plastic deformation and void growth were analyzed using discrete dislocation dynamics in an isolated FCC single crystal deformed in-plane strain in the  plane. Three different stress states (uniaxial tension, uniaxial deformation and biaxial deformation) were considered for crystals oriented in different directions and with a different number of active slip systems. It was found that strain hardening and void growth rates depended on lattice orientation in uniaxial tension because of anisotropic stress state. Crystal orientation did not influence, however, hardening and void growth when the crystals were loaded under uniaxial or biaxial deformation because the stress state was more homogeneous, although both (hardening and void growth rates) were much higher than under uniaxial tension. In addition, the number of active slip systems did not substantially modify the mechanical behavior and the void growth rate if plastic deformation along the available slip systems was compatible with overall crystal deformation prescribed by the boundary conditions. Otherwise, the incompatibility between plastic deformation and boundary conditions led to the development of large hydrostatic elastic stresses, which increased the strain hardening rate and reduced the void growth rate
Power output ﬂuctuations in large scale PV plants: one year observations with one second resolution and a derived analytic model

The variable nature of the irradiance can produce significant fluctuations in the power generated by large grid-connected photovoltaic (PV) plants. Experimental 1 s data were collected throughout a year from six PV plants, 18 MWp in total. Then, the dependence of short (below 10 min) power fluctuation on PV plant size has been investigated. The analysis focuses on the study of fluctuation frequency as well as the maximum fluctuation value registered. An analytic model able to describe the frequency of a given fluctuation for a certain day is propose
Towards 35% Efficient Concentrator Modules Based On LPI Köhler Concentrators With External Confinement Cavities

Multijunction solar cells present a certain reflectivity on its surface that lowers its light absorption. This reflectivity produces a loss in electrical efficiency and thus a loss in global energy production for CPV systems. We present here an optical design for recovering this portion of reflected light, and thus leading to a system efficiency increase. This new design is based on an external confinement cavity, an optical element able to redirect the light reflected by the cell towards its surface again. We have proven the excellent performance of these cavities integrated in CPV modules offering outstanding results: 33.2% module electrical efficiency @Tcell  =  25 °C and relative efficiency and Isc gains of over 6
Comparative analysis of road financing approaches in Europe and the United States

Road infrastructure has a remarkable economic and social impact on society. This is why road financing has always drawn the attention of policymakers, especially when resources available for government spending become scarce. Nations exhibit differing approaches to dealing with road transportation financing. In the United States, the current system of road funding has been called into question because some regard it as insufficient to meet the amounts now required for road expenditures. By contrast, in most European countries, road charges are very high, but these revenues are not allocated for the funding of roads. This paper analyzes the balance between charging for the use of and expenditure on the road sector in the United States and compares the American policy with those of several European countries (Germany, United Kingdom, France, Spain, and Switzerland). To that end, a methodology is defined to calculate the annual amount of fee charges levied on light and heavy vehicles in the selected countries in order to compare those charges with annual road expenditures. The results show that road charges in America are noticeably lower than those paid in Europe. Additionally, the research concludes that in Europe, road-generated revenues exceed road expenditures in all the countries studied, so road charges actually subsidize other policies. By contrast, in the United States, the public sector subsidizes the road system in order to maintain the current level of expenditure
The Portuguese version of the Basic Empathy Scale (BES): dimensionality and measurement invariance in a community adolescent sample

Empathy is the heightened ability to cognitively perceive and/or affectively share the emotions of others, which has been consistently associated with desirable social interactions. This paper aimed to test the bi-factorial structure of a Portuguese version of the Basic Empathy Scale and examine its variation by gender and age using a large community sample (n = 1029) of adolescents. The two-factor model, originally developed and supported by other cross-cultural validations, presented good fit indicators which was similar across genders and adolescent age groups. Girls were more empathic than boys and younger adolescents were more empathic than the older ones. Further support for the validity of the new scale comes from its relations to measures of social skills and aggression which were similar to theoretical predictions. In conclusion, the Portuguese version of the BES is a consistent and valid instrument for the assessment of empathy in samples of adolescents aged 12–18 years old in Portugal, which can now be used in cross-cultural studies of this important psychological construct
Sol-gel coatings with lime repellent properties

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)Calcification of surfaces by hard water represents a major issue for sanitary installations. Calcium carbonate precipitates forming crusts of lime that are difficult to remove. Much effort has been undertaken to avoid scaling, most methods require chemicals or create waste. We constructed a test rig which allows for the controlled calcification of various substrates. It is found that all solid surfaces investigated calcify more or less evenly. On the other hand, surface bound poly(ethylene glycol), PEG, is known to prevent the non-specific adsorption of biomolecules. PEG coated surfaces find their use in a variety of applications. Here we show that glass and plastics, such as polyethylene, polypropylene and acrylonitrile-butadiene-styrene, can be efficiently made lime repellent by the use of sol-gel coatings containing a PEG bearing silane. It is shown that the amount of scaling is drastically reduced. Prior to coating, plastics have to be pretreated by oxygen plasma and an adhesion promoter has to be employed
Ontology change management and identification of change patterns

Ontologies can support a variety of purposes,\ud
ranging from capturing the conceptual knowledge\ud
to the organisation of digital content and information.\ud
However, information systems are always subject to\ud
change and ontology change management can pose challenges.\ud
In this sense, the application and representation\ud
of ontology changes in terms of higher-level change operations\ud
can describe more meaningful semantics behind\ud
the applied change. In this paper, we propose a\ud
fourphase process that covers the operationalization,\ud
representation and detection of higherlevel changes in\ud
ontology evolution life cycle. We present different levels\ud
of change operators based on the granularity and\ud
domainspecificity of changes. The first layer is based on\ud
generic atomic level change operators, whereas the next\ud
two layers are user-defined (generic/domainspecific) change\ud
patterns. We introduce layered change logs for the explicit operational representation of ontology changes.\ud
We formalised the change log using a graph-based approach.\ud
We introduce a technique to identify composite\ud
changes that not only assists in formulating ontology\ud
change log data in a more concise manner, but\ud
also helps in realizing the semantics and intent behind\ud
any applied change. Furthermore, we identify frequent\ud
change sequences that are applied as a reference in order\ud
to discover reusable, often domainspecific and usagedriven\ud
change patterns. We describe the pattern identification\ud
algorithms and evaluate their performance
The ASY-EOS Experiment at GSI

The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of heavy ions at pre-relativistic energies has been proposed as an observable sensitive to the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. In the ASY-EOS experiment at the GSI laboratory, flows of neutrons and light charged particles were measured for 197Au+197Au collisions at 400 MeV/nucleon. Flow results obtained for the Au+Au system, in comparison with predictions of the UrQMD transport model, confirm the moderately soft to linear density dependence of the symmetry energy deduced from the earlier FOPI-LAND data
Metformin promotes isolated rat liver mitochondria impairment

Abstract  Metformin, a drug widely used in the treatment of type 2 diabetes, has recently received attention due to the new and contrasting findings regarding its effects on mitochondrial function. In the present study, we evaluated the effect of metformin in isolated rat liver mitochondria status. We observed that metformin concentrations =8 mM induce an impairment of the respiratory chain characterized by a decrease in RCR and state 3 respiration. However, only metformin concentrations =10 mM affect the oxidative phosphorylation system by decreasing the mitochondrial transmembrane potential and increasing the repolarization lag phase. Moreover, our results show that metformin does not prevent H2O2 production, neither protects against lipid peroxidation induced by the pro-oxidant pair ADP/Fe2+. In addition, we observed that metformin exacerbates Ca2+-induced permeability transition pore opening by decreasing the capacity of mitochondria to accumulate Ca2+ and increasing the oxidation of thiol groups. Taken together, our results show that metformin can promote liver mitochondria injury predisposing to cell death.http://dx.doi.org/10.1007/s11010-007-9614-
Altered lipid metabolism in a Drosophila model of Friedreich’s ataxia

Producción CientíficaFriedreich’s ataxia (FRDA) is the most common form of autosomal recessive ataxia caused by a deficit in the
mitochondrial protein frataxin. Although demyelination is a common symptom in FRDA patients, no multicellular
model has yet been developed to study the involvement of glial cells in FRDA. Using the recently established
RNAi lines for targeted suppression of frataxin in Drosophila, we were able to study the effects of
general versus glial-specific frataxin downregulation. In particular, we wanted to study the interplay between
lowered frataxin content, lipid accumulation and peroxidation and the consequences of these effects on the
sensitivity to oxidative stress and fly fitness. Interestingly, ubiquitous frataxin reduction leads to an increase
in fatty acids catalyzing an enhancement of lipid peroxidation levels, elevating the intracellular toxic potential.
Specific loss of frataxin in glial cells triggers a similar phenotype which can be visualized by accumulating
lipid droplets in glial cells. This phenotype is associated with a reduced lifespan, an increased sensitivity
to oxidative insult, neurodegenerative effects and a serious impairment of locomotor activity. These symptoms
fit very well with our observation of an increase in intracellular toxicity by lipid peroxides.
Interestingly, co-expression of a Drosophila apolipoprotein D ortholog (glial lazarillo) has a strong protective
effect in our frataxin models, mainly by controlling the level of lipid peroxidation. Our results clearly support
a strong involvement of glial cells and lipid peroxidation in the generation of FRDA-like symptoms.2015-09-1
Influence of human breathing modes on airborne cross infection risk

Producción CientíficaCFD simulation is an accurate and reliable method to predict the risk of airborne cross-infection in a room. This paper focuses on the validation of a 3-D transient CFD model used to predict personal exposure to airborne pathogens and infection risk in a displacement ventilated room. The model provides spatial and temporal solutions of the airflow pattern in the room (temperature, velocity and turbulence), as well as contaminant concentration in a room where two thermal manikins simulate two standing people, one of whom exhales a tracer gas N2O simulating airborne contaminants. Numerical results are validated with experimental data and the model shows a high accuracy when predicting the transient cases studied. Once the model is validated, the CFD model is used to simulate different airborne cross-infection risk scenarios. Four different combinations of the manikins’ breathing modes and four different separation distances between the two manikins are studied. The results show that exhaling through the nose or mouth disperses exhaled contaminants in a completely different way and also means that exhaled contaminants are received differently. For short separation distances between breathing sources the interaction between breaths is a key factor in the airborne cross-infection for all the breathing mode combinations studied. However, for long distances the general airflow conditions in the room prove to be more important.Spanish Ministry of Economy and Competiveness to the National R&D project TRACER with references DPI2014-55357-C2-1-R and DPI2014-55357-C2-2-R. This project is cofinanced by the European Regional Development Fund (ERDF)
Linear response theory in asymmetric nuclear matter for Skyrme
  functionals including spin-orbit and tensor terms

The formalism of linear response theory for a Skyrme functional including
spin-orbit and tensor terms is generalized to the case of infinite nuclear
matter with arbitrary isospin asymmetry. Response functions are obtained by
solving an algebraic system of equations, which is explicitly given.
Spin-isospin strength functions are analyzed varying the conditions of density,
momentum transfer, asymmetry and temperature. The presence of instabilities,
including the spinodal one, is studied by means of the static susceptibility
Thermomechanical and hygroelastic properties of an epoxy system under humid and cold-warm cycling conditions

In this paper, we study the hygrothermal aging of an anhydride-cured epoxy under temperature and hygrometry conditions simulating those experienced by an aircraft in wet tropical or subtropical regions. Gravimetric and dimensional measurements were performed and they indicate that there are three stages in this aging process: the first one, corresponding to the early cycles can be called the “induction stage”. The second stage of about 1000 cycles duration, could be named the “swelling stage”, during which the volume increase is almost equal to the volume of the (liquid) water absorbed. Both the first and second stages are accompanied by modifications of the mechanical properties and the glass transition temperature. During the third (“equilibrium”) stage, up to 3000 cycles, there is no significant change in the physical properties despite the continuous increase of water uptake. This can be explained by the fact that only  physically sorbed water can influence physical properties
On a parabolic-elliptic chemotactic system with non-constant chemotactic sensitivity

We study a parabolic–elliptic chemotactic system describing the evolution of a population’s density “u” and a chemoattractant’s concentration “v”. The system considers a non-constant chemotactic sensitivity given by “χ(N−u)”, for N≥0, and a source term of logistic type “λu(1−u)”. The existence of global bounded classical solutions is proved for any χ>0, N≥0 and λ≥0. By using a comparison argument we analyze the stability of the constant steady state u=1, v=1, for a range of parameters.\ud
– For N>1 and Nλ>2χ, any positive and bounded solution converges to the steady state.\ud
– For N≤1 the steady state is locally asymptotically stable and for χN<λ, the steady state is globally asymptotically stable
General three-point functions in 4D CFT

We classify and compute, by means of the six-dimensional embedding formalism in twistor space, all possible three-point functions in four dimensional conformal field theories involving bosonic or fermionic operators in irreducible representations of the Lorentz group. We show how to impose in this formalism constraints due to conservation of bosonic or fermionic currents. The number of independent tensor structures appearing in any three-point function is obtained by a simple counting. Using the Operator Product Expansion (OPE), we can then determine the number of structures appearing in 4-point functions with arbitrary operators. This procedure is independent of the way we take the OPE between pairs of operators, namely it is consistent with crossing symmetry, as it should be. An analytic formula for the number of tensor structures for three-point correlators with two symmetric and an arbitrary bosonic (non-conserved) operators is found, which in turn allows to analytically determine the number of structures in 4-point functions of symmetric traceless tensors
Dark matter and spin-1 milli-charged particles

New physics scenarios beyond the Standard Model predict the existence of milli-charged particles. So far, only spin-1/2 and spin-0 milli-charged particles have been considered in literature, leaving out the interesting case of spin-1. We propose a minimal unitary and renormalizable model of massive milli-charged vector particles. Unitarity requires that these particles are gauge bosons of a non-abelian spontaneously broken gauge symmetry. The minimal scenario then consists of an extended Standard Model gauge group SU(2) L × U(1) Y × SU(2) D together with a SU(2) D dark Higgs boson responsible for the symmetry breaking in the dark sector. By imposing that the dark Higgs multiplet has a non-vanishing milli-hypercharge, stable milli-charged spin-1 fields arise thereby providing a potential dark matter candidate. We analyse the phenomenological constraints on this scenario and discuss their implications