An open hardware electronic controller for motorized rotary injection valves used in flow injection analysis

This work presents the design, development and the implementation of a motorized injection valve used in Flow Injection Analysis systems. The built prototype has been developed based on the open hardware, software and firmware, emergent philosophy thus helping the development of a free and independent science. This policy creates a platform of open projects that feed each other, contributing to scientific and technological development while sharing knowledge. The proposed design project can be modified to implant it in other devices or projects according to the needs of each one. Also, the open project can be a great help as teaching material in Universities, since open hardware projects are fully described and documented

Parto y distocias en la perra y en la gata

El conocimiento de la fisiología normal del parto, eutocia, resulta indispensable para reconocer y, por lo tanto, establecer un adecuado plan de actuación clínica ante un parto patológico o distócico. En la primera parte de este artículo revisamos los mecanismos del parto en la perra y en la gata poniendo especial interés en aquellos aspectos de mayor trascendencia clínica; posteriormente estudiamos el parto patológico, su diagnóstico y las técnicas obstétricas que debemos emplear para resolver el problema que plantea un parto distócico en los animales de compañía.An adequate knowledge of the physiological parturition, eutocya, results essential in order to recognize and then establishing an accurate plan of clinicalperformance, to cope with the pathological whelping or dystocia. That's why in the first part of this article the mechanism of parturition in the bitch and the queen are reviewed, watching especiaUythose aspects of clinical significance; after this we study the pathological parturition, its identification and the obstetrical techniques to use in order to get successin the resolution of the trouble that a dystocia in companion animals represents

Search for narrow energy-shifted lines in XMM-Newton AGN spectra

The detection of X-ray narrow spectral features in the 5-7 keV band is becoming increasingly more common in AGN observations, thanks to the capabilities of current X-ray satellites. Such lines, both in emission and in absorption, are mostly interpreted as arising from Iron atoms. When observed with some displacement from their rest frame position, these lines carry the potential to study the motion of circumnuclear gas in AGN, providing a diagnostic of the effects of the gravitational field of the central black hole. These narrow features have been often found with marginal statistical significance. We are carrying on a systematic search for narrow features using spectra of bright type 1 AGNs available in the XMM-Newton archive. The aim of this work is to characterise the occurrence of the narrow features phenomenon on a large sample of objects and to estimate the significance of the features through Monte Carlo simulations. The project and preliminary results are presented.Comment: 6 pages,4 figures, contributed talk presented at the Workshop "The multicoloured landscape of compact objects and their explosive origin", Cefalu' (Sicily), 11-24 June 2006, to be published by AI

Core losses analysis of the LCL filter inductor for SiC-based inverter

The ability of SiC devices to switch at high speed allows increasing significantly the power density in both converters and passive components, reducing their required size. To mitigate harmonic injection form inverters into the grid, in order to comply with power quality standards, an accurate filter design is required. Given its excellent performance, an LCL filter is the configuration most suitable in grid-connected power converters. Several parameters must be considered when designing an effective LCL filter, and the inverter-side inductor assumes a special importance because of its relevance to suppress high frequency harmonic content at the inverter side. One of the most relevant issues to be considered in the process of designing the LCL filter is the evaluation of core losses in the inverter-side inductor, which will determine the final temperature of the inductor. This paper analyses the core losses of the inverter-side inductor of an LCL filter. The proposed method is based on the computation of the current harmonics generated by the inverter and on Steinmetz’s empirical equation. As a result, core losses calculated taking into account several carrier and sideband harmonics show good agreement with the experimental values. When current harmonics are estimated by simulation, as it is done in the proposed design procedure, results are less accurate, but precise enough for a design procedure

Magneto-caloric effect in the pseudo-binary intermetallic YPrFe17 compound

We have synthesized the intermetallic YPrFe17 compound by arc-melting. X-ray and neutron powder diffraction show that the crystal structure is rhombohedral with View the MathML source space group (Th2Zn17-type). The investigated compound exhibits a broad isothermal magnetic entropy change {\Delta}SM(T) associated with the ferro-to-paramagnetic phase transition (TC \approx 290 K). The |{\Delta}SM| (\approx 2.3 J kg-1 K-1) and the relative cooling power (\approx 100 J kg-1) have been calculated for applied magnetic field changes up to 1.5 T. A single master curve for {\Delta}SM under different values of the magnetic field change can be obtained by a rescaling of the temperature axis. The results are compared and discussed in terms of the magneto-caloric effect in the isostructural R2Fe17 (R = Y, Pr and Nd) binary intermetallic alloys.Comment: Preprint, 5 pages (postprint), 4 figures, regular pape

Effect of La3+/Sr2+ ordering on the magnetic properties of La2/3Sr1/3MnO3 by first principles calculations

In this work, using DFT + U formalism, we investigate the effect of order-disorder in the A-site occupation byLa3+and Sr2+on the stability of the ferromagnetic order in La2/3Sr1/3MnO3with−Rc3symmetry. To date, adetailed theoretical discussion of such phenomenon, using a combination of different representations of theelectronic structure, is still missing in the Literature. We employed structural models consisting of 120 atomsupercells constructed according to the precise stoichiometry of the compound. Two configurations, describingrandomized and ordered occupation of the La3+/Sr2+ions, were evaluated. We demonstrate that the ferro-magnetic arrangement of La2/3Sr1/3MnO3with randomly distributed La3+and Sr2+ions is more stable. In suchconfiguration wefind that the Mn3+and Mn4+ions are not distinguished, favoring the double-exchange me-chanism, enhanced by the higher degree of covalence in the MneO bonds near the Fermi level between thespin-upMn-egorbitals and the O-porbitals

Are subjective outcomes a “missing link” between driving stress and risky driving behaviors of commuters? Assessing the case of a LMIC

Despite the efforts made by different stakeholders, most of Low and Middle-Income Countries (LMICs) continue to systematically report very negative road safety outcomes. In fact, in countries like Colombia, the rate of deaths from traffic crashes has increased in recent years. One of the most affected collectives in this regard -and at the same time one of the least addressed in specialized literature- are driving commuters, which are commonly exposed to several types of threats and stressors configuring an “everyday risk” potentially impairing their health and safety. This study aimed to assess whether there exists an indirect path -mediated by subjective outcomes- linking driving stress and risky driving behaviors among Colombian commuters. For this study, it was analyzed the data provided by a full sample of 941 driving commuters from different industries (18 % females, 82 % males) with a mean age of 37 years. The results of this research suggest that exposure to driving stressors is a risk factor for risky driving. Furthermore, these outcomes are consistent with previous evidence linking adverse subjective states such as fatigue and psychological strain with impaired driving performance. This statistical mediation exerted by subjective outcomes, which can be considered partial, suggests that interventions focused on managing driving stress and reducing road stressors can enhance both their psychological welfare and commuting safety outcomes

Oteiza y Oíza: el espacio expositivo como percepción temporal

There are not many examples in the architectural panorama of museums built to house the visual artwork of a single artist. Even less when the artist actively collaborates in the architectural conception of the space that should receive his legacy. This research establishes a relational reading to understand the connections between the way in which Jorge Oteiza (1908-2003) proposes that his sculptures should be exhibited, exemplified in the exhibition montage suggested for his participation in the IV São Paulo Modern Art Biennial in 1957, and the project for the Foundation and Museum in Alzuza, Navarra, the work of his good friend Francisco Javier Sáenz de Oíza (1918-2000). In both cases, the use of time as an instrument for controlling perception will be essential to achieve greater coherence between the museum space and the displayed work.No existen muchos ejemplos en el panorama arquitectónico de museos realizados para albergar la obra plástica de un solo artista. Menos aún cuando el artista colabora de manera activa en la concepción arquitectónica del espacio que debe acoger su legado. Esta investigación establece una lectura relacional para comprender las conexiones entre el modo en el que Jorge Oteiza (1908-2003) propone deben ser expuestas sus esculturas, ejemplificado en el montaje expositivo planteado para su participación en la IV Bienal de Arte Moderna de São Paulo en 1957, y el proyecto para su Fundación y Museo en Alzuza, Navarra, obra de su gran amigo Francisco Javier Sáenz de Oíza (1918-2000). En ambos casos la utilización del tiempo como instrumento de control de la percepción será esencial para conseguir una mayor coherencia entre el espacio museístico y la obra mostrada