Lightweight solar panel development

Preliminary design, fabrication, and test of lightweight solar panel of built-up beryllium structure with 29 sq ft active cell are

Mariner Venus 67 solar panel

Design, assembly, tests, and postflight analysis of Mariner Venus 67 solar pane

¿Podrán los Millennials cobrar pensión?: una aplicación al caso de México

Màster de Direcció d'Entitats Asseguradores i Financeres, Universitat de Barcelona, Facultat d'Economia i Empresa, Curs: 2016-2017, Tutor: Juan José López SanzLa generación conocida como Millennials que actualmente tiene entre 18 y 35 años está redefiniendo las relaciones laborales, tanto que se prevé que en el año 2025 sea la mayor fuerza laboral en el mundo. Sin embargo esta generación del milenio caracterizada por ser una generación inconforme, adicta a la tecnología y con la creencia de que se merecen todo solo por el simple hecho de quererlo, es insensible al tema de las pensiones pensando poco en el momento de su retiro. Los Millenials mexicanos confían en llegar a la jubilación pero parece que aún no comprenden que ésta será muy diferente a la de sus padres y abuelos. El nuevo sistema de pensiones tampoco favorece a los Millennials debido a las exigencias mínimas que esta generación no tiene afianzadas, así como a una cultura de ahorro, que por el momento se encuentra poco interiorizada en México. El conocimiento de los retos estructurales a los que se enfrentan, trabajar más tiempo y ahorrar más, son la mejor forma de enfrentarse al futuro que tiene esta generación

Retablo mayor de la iglesia del Hospital de la Caridad. Investigación e intervención

A partir de las investigaciones y estudios preliminares recogidos en el proyecto inicial que se realizó en el Instituto Andaluz del Patrimonio Histórico, la restauración del retablo mayor de la iglesia del Hospital de la Santa Caridad de Sevilla corrió a cargo de la Dirección General de Bienes Culturales de la Junta de Andalucía, bajo la tutela del Proyecto de estudio, investigación y propuesta de intervención del retablo mayor de la iglesia de San Jorge del Hospital de la Caridad. La fase de intervención, iniciada en enero de 2006, ha supuesto para este retablo la oportunidad de profundizar en el estudio de su materialidad, mediante los análisis científicos de caracterización de materiales y la actualización de los datos histórico-artísticos y de historia material. Por otra parte, los tratamientos aplicados garantizarán la adecuada conservación de su arquitectura y esculturas en el futuro, contribuyendo de forma significativa a la recuperación de los valores históricos y artísticos de este magnífico retablo

Precision Study of Positronium: Testing Bound State QED Theory

As an unstable light pure leptonic system, positronium is a very specific probe atom to test bound state QED. In contrast to ordinary QED for free leptons, the bound state QED theory is not so well understood and bound state approaches deserve highly accurate tests. We present a brief overview of precision studies of positronium paying special attention to uncertainties of theory as well as comparison of theory and experiment. We also consider in detail advantages and disadvantages of positronium tests compared to other QED experiments.Comment: A talk presented at Workshop on Positronium Physics (ETH Zurich, May 30-31, 2003

Goal-Directed Fluid Therapy Using Stroke Volume Variation Does Not Result in Pulmonary Fluid Overload in Thoracic Surgery Requiring One-Lung Ventilation

Background. Goal-directed fluid therapy (GDT) guided by functional parameters of preload, such as stroke volume variation (SVV), seems to optimize hemodynamics and possibly improves clinical outcome. However, this strategy is believed to be rather fluid aggressive, and, furthermore, during surgery requiring thoracotomy, the ability of SVV to predict volume responsiveness has raised some controversy. So far it is not known whether GDT is associated with pulmonary fluid overload and a deleterious reduction in pulmonary function in thoracic surgery requiring one-lung-ventilation (OLV). Therefore, we assessed the perioperative course of extravascular lung water index (EVLWI) and p a O 2 /F i O 2 -ratio during and after thoracic surgery requiring lateral thoracotomy and OLV to evaluate the hypothesis that fluid therapy guided by SVV results in pulmonary fluid overload. Methods. A total of 27 patients (group T) were enrolled in this prospective study with 11 patients undergoing lung surgery (group L) and 16 patients undergoing esophagectomy (group E). Goal-directed fluid management was guided by SVV (SVV < 10%). Measurements were performed directly after induction of anesthesia (baseline-BL), 15 minutes after implementation OLV (OLVimpl15), and 15 minutes after termination of OLV (OLVterm15). In addition, postoperative measurements were performed at 6 (6postop), 12 (12postop), and 24 (24postop) hours after surgery. EVLWI was measured at all predefined steps. The p a O 2 /F i O 2 -ratio was determined at each point during mechanical ventilation (group L: BL-OLVterm15; group E: BL-24postop). Results. In all patients (group T), there was no significant change (P > 0.05) in EVLWI during the observation period (BL: 7.8 ± 2.5, 24postop: 8.1 ± 2.4 mL/kg). A subgroup analysis for group L and group E also did not reveal significant changes of EVLWI. The p a O 2 /F i O 2 -ratio decreased significantly during the observation period (group L: BL: 462 ± 140, OLVterm15: 338 ± 112 mmHg; group E: BL: 389 ± 101, 24postop: 303 ± 74 mmHg) but remained >300 mmHg except during OLV. Conclusions. SVV-guided fluid management in thoracic surgery requiring lateral thoracotomy and one-lung ventilation does not result in pulmonary fluid overload. Although oxygenation was reduced, pulmonary function remained within a clinically acceptable range

alpha^2 corrections to parapositronium decay: a detailed description

We present details of our recent calculation of alpha^2 corrections to the parapositronium decay into two photons. These corrections are rather small and our final result for the parapositronium lifetime agrees well with the most recent measurement. Implications for orthopositronium decays are briefly discussed.Comment: 18 pages, late

Precision physics of simple atoms: QED tests, nuclear structure and fundamental constants

Quantum electrodynamics is the first successful and still the most successful quantum field theory. Simple atoms, being essentially QED systems, allow highly accurate theoretical predictions. Because of their simple spectra, such atoms have been also efficiently studied experimentally frequently offering the most precisely measured quantities. Our review is devoted to comparison of theory and experiment in the field of precision physics of light simple atoms. In particular, we consider the Lamb shift in the hydrogen atom, the hyperfine structure in hydrogen, deuterium, helium-3 ion, muonium and positronium, as well as a number of other transitions in positronium. Additionally to a spectrum of unperturbed atoms, we consider annihilation decay of positronium and the g factor of bound particles in various two-body atoms. Special attention is paid to the uncertainty of the QED calculations due to the uncalculated higher-order corrections and effects of the nuclear structure. We also discuss applications of simple atoms to determination of several fundamental constants