Construcció d'un refugi situat al terme municipal de Vallfogona de Ripollès, pensat com a final d'etapa per a rutes a cavall

Els negocis relacionats amb les activitats de lleure i els esports d’aventura actualment es troben en expansió, buscant majoritàriament el contacte amb la natura. Les rutes a cavall formen part del gran ventall d’opcions, per aquesta qüestió s’ha pensat en construir un refugi utilitzat com a final d’etapa per a rutes a cavall. En la major part del territori, la presència de població humana es manifesta en pobles, viles i ciutats, les quals disposes d’aigua sanitària, corrent elèctric i sistema de clavegueram. Per altra banda en les urbanitzacions o cases aïllades poder gaudir d’aquests serveis suposa una inversió econòmica elevada, que implica la utilització de sistemes alternatius. En el present projecte s’ha triat un emplaçament on portar a terme el final d’etapa amb una sèrie de requisits a complir : bosc a les proximitats, disposar d’un o varis accessos per a vehicles (transport del material d’intendència), tranquil•litat, bones vistes, i cobertura de telèfon mòbil. S’han acceptat les següents limitacions : no disposar de xarxa pública d’electricitat ni d’aigua. I s’han dimensionat les instal•lacions per a un màxim de dotze persones i els seus respectius cavalls. El principal objectiu del projecte és el dimensionament de les necessitats elèctriques, d’aigua i d’aiguacalenta sanitària en condicions autònomes, i utilitzant energies renovables. La valoració de les possibles solucions per condicionar les instal•lacions, i oferir una resposta eficient per la demanda. No és un objectiu específic del treball la potabilització de l’aigua ni el tractament dels residus produïts. S’han aprofitat els diferents desnivells que presenta l’emplaçament triat a l’hora de distribuir les instal•lacions, i s’ha utilitzat un antic cobert de dos pisos ja existent. Com a residència s’ha triat un model de casa prefabricada de muntanya. Com a sistema de subministrament elèctric, s’instal•laran plaques solars fotovoltaiques i un generador de corrent com a sistema auxiliar. La captació d’aigua s’efectuarà a partir d’un pou que es troba en el terreny i de la recollida d el’aigua pluvial, instal•lant dipòsits d’emmagatzemament d’aigua segons les necessitats. S’utilitzarà un equip de cloració per potabilitzar l’aigua de consum utilitzada a la residència. En la producció d’aigua calenta sanitària s’utilitzaran plaques solars tèrmiques i una caldera instantània de gas propà com a suport. Per cuinar s’ha triat una cuina de gas propà i una barbacoa que s’instal•larà a l’exterior. S’instal•larà una llar de foc amb recuperador d’aire a la residència i una fosa sèptica amb un sistema d’infiltració per poder abocar les aigües provinents de la residència. Els fems dels cavalls podran ser utilitzats com adob pel terreny.

Proyecto de ejecución para las obras de concesión de dominio público para la reforma y adecuación de la central térmica y de la red de saneamiento en un hospital de 350 camas

El Hospital Punta de Europa en Algeciras (Cádiz), centro sanitario del Servicio Andaluz de Salud, desea optimizar la gestión de sus instalaciones de generación de energía térmica (vapor, agua caliente sanitaria y agua caliente de calefacción) y adecuarlas a la normativa vigente así como la sustitución de bajantes del edificio, para lo cual sacará a concurso público la licitación para la concesión de dominio público de dichas instalaciones. Para definir el alcance y condiciones de la citada concesión, el Hospital Punta de Europa (Algeciras) del Servicio Andaluz de Salud ha solicitado a Pedro Alonso Martín el estudio para la reforma y adecuación de las instalaciones productoras de energía térmica del citado Hospital. El objetivo principal de este trabajo es hacer un estudio, propuesta y valoración de las actuaciones necesarias para la reforma y mejora de la explotación de las instalaciones generadoras de energía térmica y de la red saneamiento interior del Hospital Punta de Europa de Algeciras (Cádiz). Las actuales instalaciones de generación térmica consumidoras de energía del hospital dentro del alcance de este Proyecto son: Generación de vapor (lavandería y esterilización). Producción de agua caliente sanitaria (ACS). Producción de agua caliente de calefacción. La mayoría de los equipos productores de energía datan del año 1975, por lo que en la mayoría de los casos se ha cumplido su plazo de amortización y periodo de vida útil. Se hace necesaria la instalación de gas natural, debido a que se tendrá que abastecer a todas las calderas de la central térmica. El diseño del sistema de producción de agua caliente sanitaria garantiza el máximo confort y economía del usuario, compatible con el máximo ahorro energético y la protección del medio ambiente, cubriendo las necesidades de agua caliente sanitaria mediante la combinación de un sistema de calderas a gas con los colectores solares.

A new estimator to minimize the error due to breathing in the measurement of respiratory impedance

This paper presents a new respiratory impedance estimator to minimize the error due to breathing. Its practical reliability was evaluated in a simulation using realistic signals. These signals were generated by superposing pressure and flow records obtained in two conditions: 1) when applying forced oscillation to a resistance- inertance- elastance (RIE) mechanical model; 2) when healthy subjects breathed through the unexcited forced oscillation generator. Impedances computed (4-32 Hz) from the simulated signals with the new estimator resulted in a mean value which was scarcely biased by the added breathing (errors less than 1 percent in the mean R, I , and E ) and had a small variability (coefficients of variation of R, I, and E of 1.3, 3.5, and 9.6 percent, respectively). Our results suggest that the proposed estimator reduces the error in measurement of respiratory impedance without appreciable extracomputational cost.

Bacterial colonization and infection of electrophysiological cardiac devices detected with sonication and swab culture.

BACKGROUND: Electrophysiological cardiac devices are increasingly used. The frequency of subclinical infection is unknown. We investigated all explanted devices using sonication, a method for detection of microbial biofilms on foreign bodies. METHODS AND RESULTS: Consecutive patients in whom cardiac pacemakers and implantable cardioverter/defibrillators were removed at our institution between October 2007 and December 2008 were prospectively included. Devices (generator and/or leads) were aseptically removed and sonicated, and the resulting sonication fluid was cultured. In parallel, conventional swabs of the generator pouch were performed. A total of 121 removed devices (68 pacemakers, 53 implantable cardioverter/defibrillators) were included. The reasons for removal were insufficient battery charge (n=102), device upgrading (n=9), device dysfunction (n=4), or infection (n=6). In 115 episodes (95%) without clinical evidence of infection, 44 (38%) grew bacteria in sonication fluid, including Propionibacterium acnes (n=27), coagulase-negative staphylococci (n=11), Gram-positive anaerobe cocci (n=3), Gram-positive anaerobe rods (n=1), Gram-negative rods (n=1), and mixed bacteria (n=1). In 21 of 44 sonication-positive episodes, bacterial counts were significant (>or=10 colony-forming units/mL of sonication fluid). In 26 sterilized controls, sonication cultures remained negative in 25 cases (96%). In 112 cases without clinical infection, conventional swab cultures were performed: 30 cultures (27%) were positive, and 18 (60%) were concordant with sonication fluid cultures. Six devices and leads were removed because of infection, growing Staphylococcus aureus, Streptococcus mitis, and coagulase-negative staphylococci in 6 sonication fluid cultures and 4 conventional swab cultures. CONCLUSIONS: Bacteria can colonize cardiac electrophysiological devices without clinical signs of infection.

Pinning of quantized vortices in helium drops by dopant atoms and molecules

Using a density functional method, we investigate the properties of liquid 4He droplets doped with atoms (Ne and Xe) and molecules ( SF6 and hydrogen cyanide). We consider the case of droplets having a quantized vortex pinned to the dopant. A liquid-drop formula is proposed that accurately describes the total energy of the complex and allows one to extrapolate the density functional results to large N. For a given impurity, we find that the formation of a dopant+vortex+4HeN complex is energetically favored below a critical size Ncr. Our results support the possibility to observe quantized vortices in helium droplets by means of spectroscopic techniques.

Quantized vortices in mixed 3He-4He drops

Using density functional theory, we investigate the structure of mixed 3HeN3-4HeN4 droplets with an embedded impurity (Xe atom or HCN molecule) which pins a quantized vortex line. We find that the dopant+vortex+4HeN4 complex, which in a previous work [F. Dalfovo et al., Phys. Rev. Lett. 85, 1028 (2000)] was found to be energetically stable below a critical size Ncr, is robust against the addition of 3He. While 3He atoms are distributed along the vortex line and on the surface of the 4He drop, the impurity is mostly coated by 4He atoms. Results for N4 = 500 and a number of 3He atoms ranging from 0 to 100 are presented, and the binding energy of the dopant to the vortex line is determined.

Probing vortices in 4He nanodroplets

We present static and dynamical properties of linear vortices in 4He droplets obtained from density functional calculations. By comparing the adsorption properties of different atomic impurities embedded in pure droplets and in droplets where a quantized vortex has been created, we suggest that Ca atoms should be the dopant of choice to detect vortices by means of spectroscopic experiments.

Off-axis vortices in trapped Bose-condensed gases: Angular momentum and frequency splitting

We consider noncentered vortices and their arrays in a cylindrically trapped Bose-Einstein condensate at zero temperature. We study the kinetic energy and the angular momentum per particle in the Thomas-Fermi regime and their dependence on the distance of the vortices from the center of the trap. Using a perturbative approach with respect to the velocity field of the vortices, we calculate, to first order, the frequency shift of the collective low-lying excitations due to the presence of an off-center vortex or a vortex array, and compare these results with predictions that would be obtained by the application of a simple sum-rule approach, previously found to be very successful for centered vortices. It turns out that the simple sum-rule approach fails for off-centered vortices.

Vortices in atomic Bose-Einstein condensates in the large-gas-parameter region

In this work we compare the results of the Gross-Pitaevskii and modified Gross-Pitaevskii equations with ab initio variational Monte Carlo calculations for Bose-Einstein condensates of atoms in axially symmetric traps. We examine both the ground state and excited states having a vortex line along the z axis at high values of the gas parameter and demonstrate an excellent agreement between the modified Gross-Pitaevskii and ab initio Monte Carlo methods, both for the ground and vortex states.

Threading dislocation lines in two-sided flux-array decorations

Two-sided flux decoration experiments indicate that threading dislocation lines (TDLs), which cross the entire film, are sometimes trapped in metastable states. We calculate the elastic energy associated with the meanderings of a TDL. The TDL behaves as an anisotropic and dispersive string with thermal fluctuations largely along its Burgers vector. These fluctuations also modify the structure factor of the vortex solid. Both effects can, in principle, be used to estimate the elastic moduli of the material.

Can extreme black Holes have (long) Abelian Higgs hair?

It has been argued that a black hole horizon can support the long-range fields of a Nielsen-Olesen string and that one can think of such a vortex as black hole "hair." In this paper, we examine the properties of an Abelian Higgs vortex in the presence of a charged black hole as we allow the hole to approach extremality. Using both analytical and numerical techniques, we show that the magnetic field lines (as well as the scalar field) of the vortex are completely expelled from the black hole in the extreme limit. This was to be expected, since extreme black holes in Einstein-Maxwell theory are known to exhibit such a "Meissner effect" in general. This would seem to imply that a vortex does not want to be attached to an extreme black hole. We calculate the total energy of the vortex fields in the presence of an extreme black hole. When the hole is small relative to the size of the vortex, it is energetically favored for the hole to remain inside the vortex region, contrary to the intuition that the hole should be expelled. However, as we allow the extreme horizon radius to become very large compared to the radius of the vortex, we do find evidence of an instability. This proves that it is energetically unfavorable for a thin vortex to interact with a large extreme black hole. This would seem to dispel the notion that a black hole can support "long" Abelian Higgs hair in the extreme limit. We show that these considerations do not go through in the near-extreme limit. Finally, we discuss the implications for strings that end at black holes, as in the processes where a string snaps by nucleating black holes.

Vortices and extreme black holes: The question of flux expulsion

It has been claimed that extreme black holes exhibit a phenomenon of flux expulsion for Abelian Higgs vortices, irrespective of the relative width of the vortex to the black hole. Recent work by two of the authors showed a subtlety in the treatment of the event horizon, which cast doubt on this claim. We analyze in detail the vortexextreme black hole system, showing that, while flux expulsion can occur, it does not do so in all cases. We give analytic proofs for both expulsion and penetration of flux, in each case deriving a bound for that behavior. We also present extensive numerical work backing up, and refining, these claims, and showing in detail how a vortex can end on a black hole in all situations. We also calculate the back reaction of the vortex on the geometry, and comment on the more general vortexblack hole system.

Absence of Abelian Higgs Hair for Extreme Black Holes

It has been argued that a black hole horizon can support the long range fields of a Nielsen-Olesen string, and that one can think of such a vortex as black hole hair. We show that the fields inside the vortex are completely expelled from a charged black hole in the extreme limit (but not in the near extreme limit). This would seem to imply that a vortex cannot be attached to an extreme black hole. Furthermore, we provide evidence that it is energetically unfavorable for a thin vortex to interact with a large extreme black hole. This dispels the notion that a black hole can support long Abelian Higgs hair in the extreme limit.

Tuning clustering in random networks with arbitrary degree distributions

We present a generator of random networks where both the degree-dependent clustering coefficient and the degree distribution are tunable. Following the same philosophy as in the configuration model, the degree distribution and the clustering coefficient for each class of nodes of degree k are fixed ad hoc and a priori. The algorithm generates corresponding topologies by applying first a closure of triangles and second the classical closure of remaining free stubs. The procedure unveils an universal relation among clustering and degree-degree correlations for all networks, where the level of assortativity establishes an upper limit to the level of clustering. Maximum assortativity ensures no restriction on the decay of the clustering coefficient whereas disassortativity sets a stronger constraint on its behavior. Correlation measures in real networks are seen to observe this structural bound.