Two-Loop Renormalization of Heavy--Light Currents at Order 1/m_Q in the Heavy-Quark Expansion

We present exact results, at next-to-leading order in renormalization-group improved perturbation theory, for the Wilson coefficients appearing at order 1/m_Q in the heavy-quark expansion of heavy-light current operators. To this end, we complete the calculation of the corresponding two-loop anomalous dimension matrix. Our results are important for determinations of |V_{ub}| using exclusive and inclusive semileptonic B decays. They are also relevant to computations of the decay constant f_B based on a heavy-quark expansion.Comment: 16 pages, 2 figures; third author added and one reference updated, results unchange

The SU(2) and SU(3) chiral phase transitions within Chiral Perturbation Theory

The SU(2) and SU(3) chiral phase transitions in a hot gas made of pions, kaons and etas are studied within the framework of Chiral Perturbation Theory. By using the meson meson scattering phase shifts in a second order virial expansion, we are able to describe the temperature dependence of the quark condensates. We have estimated the critical temperatures where the different condensates melt. In particular, the SU(3) formalism yields a lower critical temperature for the non-strange condensates than within SU(2), and also suggests that the strange condensate may melt at a somewhat higher temperature, due to the different strange and non-strange quark masses.Comment: 4 pages, two figures. Final version to appear in Phys Rev D. Complete model independent calculation. Unitarized ChPt only used to check extrapolation at high T. References added and numerical bug correcte

Aplasia del arco posterior del Atlas

Las anomalías congénitas del arco posterior del Atlas son poco frecuentes. Se presenta el caso de una paciente, que tras sufrir un accidente se diagnosticó de aplasia parcial del atlas. Esta lesión es considerada como una variante anatómica benigna de la región cráneovertebral. Se expone el desarrollo y el significado de esta anomalía.Congenital anomalies of the posterior arch of the atlas are uncommon. This paper presents the case of a patient who, as result of an accident, was diagnosed as having a congenital partial agenesia of the posterior arch of the atlas. This finding is considered as a benign anatomical variation of the craniovertebral junction region. The development and clinical significance of this anomaly are discussed

Fracturas diafisarias de húmero en adultos: estudio retrospectivo de 53 casos

Se estudian retrospectivamente 53 pacientes adultos con fractura diafisaria de húmero, 36 de los cuales siguieron el tratamiento ortopédico funcional. En otros 17 casos, pacientes politraumatizados o con fracturas de tercio medio transversas, realizamos tratamiento quirúrgico. La edad media de los pacientes fue 48 ± 2 2 años. Se afectó más el lado derecho, siendo el antecedente etiológico más frecuente el accidente casual. No hubo diferencia entre el tiempo de consolidación con el tratamiento ortopédico-funcional (60 ± 14 días) y el tratamiento quirúrgico (56 ±1 2 días). Como complicaciones hubo 7 pseudoartrosis (4 tras tratamiento ortopédico-funcional y 3 tratamiento quirúrgico). La edad media de los pacientes con pseudoartrosis fue superior a la de los pacientes con consolidación completa. Ocho casos cursaron con lesión del nervio radial, obteniendo una recuperación funcional del 100% en un tiempo medio de 38 ± 30 semanas. Valorando los resultados con arreglo a los criterios de Gayet, hemos obtenido un 80% de buenos y muy buenos resultados con tratamiento ortopédico funcional y un 70% con tratamiento quirúrgico.Fifty three adult patients with fracture of the humeral shaft were retrospectively studied. Orthopaedic-functional treatment was applied in 36 cases. Seventeen patients with either multiple injuries or transverse middle-shaft fractures were surgically treated. The mean age of patients was 48 ± 21 years. Right side was most frecuently affected and casual fall was the predominated etiology. There were no differences regarding the average consolidation period between fractures treated conservatively (60 ± 14 days) and those undergoing surgery (56 ± 12 days). As complications, there were 7 monounions (4 conservative and 3 operative treatment). The mean age of patients with non-unions was higther than those with complete fracture consolidation. Radial nerve injury was seen in 8 cases. In all there patients, a complete functional were recovery was obtained with a mean average time of 38 ± 30 weeks. When evaluating functional results according to Gayet, satisfactory results were found in 80 per cent of patients with conservative treatment and 70 per cent of those surgically treated

Development of a critical structure state alarm system based on the instrumentation of the Botafoc breakwater nº 8 caisson

Balearic Port Authority has developed an instrumentation system for the #8 caisson of the Botafoc breakwater that integrates 12 pressure sensors located at three surfaces, two in contact with the sea water and another with the bottom. This design was completed with an inertial system that measures the angular velocities and the accelerations over the three Cartesian axes. Consequently, the system measures actions (pressures) and reactions (movements and accelerations) experimented by the caisson, due to sea waves and/or other service loads. R+D department of the Port Authority and Polytechnic University of Madrid are working on two directions, the development of new theories on vertical breakwater design that go beyond Goda and Sainflou, and on the creation of a real-time critical structure alarm system, based on the instrumentation installed. This alarm system has two main parts: the instrumentation itself that collects data and processes it on real-time (the data processing compares the pressure law suffered by the caisson in every step process with the design critical state of the caisson, in this case the Goda pressure law for a 6.5 m wave), giving a security coefficient that points out the risk level on real-time; and the alarm system consisting of a monitoring panel located in the Port Control Center that shows the risk level and advises in case of an incidental evacuation of this critical portuary installation

Osteosíntesis con tornillos de Kadar en las fracturas de cuello femoral

Se estudian retrospectivamente 30 pacientes con fractura de cuello femoral, tipo I y II de Garden, tratadas con osteosíntesis a compresión mediante tornillos de esponjosa tipo Kadar. La edad media de los pacientes fue de 70±19 años, siendo el accidente casual la etiología de todas ellas. Se valoró la calidad de la reducción y de la fijación mediante criterios radiográficos, siendo la reducción óptima en el 93 % de los pacientes y la fijación en el 50%. Como complicaciones hubo 2 desplazamientos precoces de la fractura. No ha habido ninguna pseudoartrosis ni necrosis avascular. Valorando los resultados con arreglo a los criterios de Merle d'Aubigné, hemos obtenidos un 84% de buenos resultados. Creemos que el factor pronóstico más importante es la reducción anatómica de la fractura.Thirty patients with Garden's type I and II femoral neck fracture treated by Kadar's spongiosa compressive screws were retrospectively studied. The mean age of patients was 70±9 years. In all cases, the etiology was a casual accident. Fracture reduction and positioning of the osteosynthesis were assessed by radiographic criteria. Satisfactory reduction was achieved in 93 percent of the patients, and the osteosynthesis was accurate in 50 per cent. As for complications, there were 2 early fracture redisplacement. There were neither non-union nor avascular necrosis. When evaluating functional results according to Merle d'Aubigné criteria, satisfactory results were found in 84 per cent of patients. In our opinion, the more important pronostic factor is the anatomic reduction of the fracture

Integration of modular process simulators under the Generalized Disjunctive Programming framework for the structural flowsheet optimization

The optimization of chemical processes where the flowsheet topology is not kept fixed is a challenging discrete-continuous optimization problem. Usually, this task has been performed through equation based models. This approach presents several problems, as tedious and complicated component properties estimation or the handling of huge problems (with thousands of equations and variables). We propose a GDP approach as an alternative to the MINLP models coupled with a flowsheet program. The novelty of this approach relies on using a commercial modular process simulator where the superstructure is drawn directly on the graphical use interface of the simulator. This methodology takes advantage of modular process simulators (specially tailored numerical methods, reliability, and robustness) and the flexibility of the GDP formulation for the modeling and solution. The optimization tool proposed is successfully applied to the synthesis of a methanol plant where different alternatives are available for the streams, equipment and process conditions.Spanish Ministry of Science and Innovation (CTQ2012-37039-C02-02)

A new technique for recovering energy in thermally coupled distillation using vapor recompression cycles

Even though it has been proved that a fully thermally coupled distillation (TCD) system minimizes the energy used by a sequence of columns, it is well-known that vapor/liquid transfers between different sections produce an unavoidable excess of vapor (liquid) in some of them, increasing both the investment and operating costs. It is proposed here to take advantage of this situation by extracting the extra vapor/liquid and subjecting it to a direct/reverse vapor compression cycle. This new arrangement restores the optimal operating conditions of some of the affected sections with energy savings of around 20–30% compared with conventional TCD columns. Various examples, including the direct and reverse vapor recompression cycles, are presented. Furthermore, in each example, all possible modes of distillation (direct, indirect and Petlyuk distillation) with and without vapor recompression cycles (VRC) are compared to ensure that this approach delivers the best results.The authors would like to acknowledge financial support from the Spanish Ministerio de Ciencias e Innovación (PPQ, CTQ2009–14420-C02-02 and CTQ2012–37039-C02-02)

Thermal rho and sigma mesons from chiral symmetry and unitarity

We study the temperature evolution of the rho and sigma mass and width, using a unitary chiral approach. The one-loop pion-pion scattering amplitude in Chiral Perturbation Theory at finite temperature is unitarized via the Inverse Amplitude Method. Our results predict a clear increase with T of both the rho and sigma widths. The masses decrease slightly for high T, while the rho-pion-pion coupling increases. The rho behavior seems to be favored by experimental results. In the sigma case, it signals chiral symmetry restoration.Comment: 5 pages, 5 figures, revtex. References and brief comments added. Final version to appear in Phys. Rev.