Spacecraft magnetic attitude control using approximating sequence Riccati equations

This paper presents the results of a spacecraft attitude control system based on magnetic actuators designed for low Earth orbits. The control system is designed by using a nonlinear control technique based on the approximating sequence of Riccati equations. The behavior of the satellite is discussed under perturbations and model uncertainties. Simulation results are presented when the control system is able to guide the spacecraft to the desired attitude in a variety of different conditions

Toward a Non Stabilized Approach assistant based on human expertise

97% of Non-Stabilized Approach (NSA) are continued until landing going against Standard Operational Procedures (SOP). For some of these approaches, the reason is a lack of situation awareness for others it is because of operational constraints that standard SOP do not take into account like ATC, remaining fuel on board, weather… Most of the time everything goes well but pilots often admit afterwards that they should have go-around and that safety margins were greatly reduced

Endoscopic Submucosal Dissection. Sociedad Española de Endoscopia Digestiva (SEED) clinical guideline

The reason to write this guideline is to familiarize Spanish endoscopists and gastroenterologists not only with the general indications of the procedure and possible complications but also the dedicated tools

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Failure Detection by Signal Similarity Measurement of Brushless DC Motors

In recent years, Brushless DC (BLDC) motors have been gaining popularity as a solution for providing mechanical power, starting from low cost mobility solutions like the electric bikes, to high performance and high reliability aeronautical Electro-Mechanical Actuator (EMA). In this framework, the availability of fault detection tools suited to these types of machines appears necessary. There is already a vast literature on this topic, but only a small percentage of the proposed techniques have been developed to a sufficiently high Technology Readiness Level (TRL) to be implementable in industrial applications. The investigation on the state of the art carried out during the first phase of the present work, tried to collect the techniques which are closest to possible implementation. To fill a gap identified in the current techniques, a partial demagnetisation detection method is proposed in this paper. This technique takes advantage of the asymmetries generated in the current by the missing magnetic flux to detect the failure. Simulations and laboratory experiments have been carried out to validate the idea, showing the potential and the easy implementation of the method. The results have been examined in detail and satisfactory conclusions have been drawn

Association between refractory hypertension and cardiometabolic risk. The HIPERFRE study

Fundamento y objetivo: Se define como hipertensión arterial refractaria (HTA-R) la persistencia del mal control de la presión en pacientes tratados con tres o más fármacos, incluyendo un diurético. Pretendemos estimar la prevalencia y las características de pacientes con HTA-R en el ámbito de la Atención Primaria en nuestro medio. Metodología: Estudio descriptivo, transversal y multicéntrico, en el que participaron 35 médicos de 14 Centros de Salud, registrando las características de 1.724 hipertensos. Resultados: Pacientes (41,5% varones) con edad media de 67 ± 11 años; la mitad, obesos. El 41,6% tienen la presión controlada y la prevalencia de HTA-R es del 13,2%. En este grupo la edad media es significativamente mayor (69 vs 67 años, p < 0,01) y son más frecuentes la obesidad (62% vs 43%, p < 0,001), la diabetes (55% vs 11%, p < 0,001), la dislipemia (68% vs 59%, p < 0,05) y el síndrome metábolico (68% vs 22%, p < 0,001). En la mitad de los pacientes hay afectación de algún órgano diana. El 3% de los pacientes no recibe tratamiento farmacológico y el 37% está con monoterapia. En el grupo de HTA-R hay mayor prescripción de ARA-II, antagonistas del calcio, bloqueadores beta y bloqueadores alfa. La HTA-R se asocia de forma independiente y directamente con la edad, el sexo masculino, la presencia de diabetes, obesidad y síndrome metabólico, e inversamente con la presencia de cardiopatía isquémica. Conclusiones: La HTA-R en el ámbito de la Atención Primaria tiene una prevalencia del 13% y se asocia con la edad, el sexo masculino y los factores de riesgo metabólicosBackground and Aim: Resistant hypertension (R-HT) is defined by the presence of uncontrolled blood pressure in patients treated with three or more drugs, being one of them diuretic. We sough to evaluate the prevalence and features of patients with R-HT attended at Primary Care of our environment. Method: 1,724 hypertensive patients attended by 35 physicians at 14 Primary Care Units were analyzed in this descriptive, transversal, multicentral study. Results: Patients (41.5% males) with a mean age of 67 ± 11 years, being half of them obese. Blood pressure is controlled in 41.6% and the prevalence of R-HT is of 13.2%. This later group of patients is characterized by an older age (69 vs 67 years, p < 0.01) and more frequent obesity (62% vs 43%, p < 0.001), diabetes (55% vs 11%, p < 0.001), hyperlipidemia (68% vs 59%, p < 0.05), and metabolic syndrome (68% vs 22%, p < 0.001). At least half of them present some kind of end-organ damage. No pharmacologycal treatment is prescribed to 3% of these patients and 37% of them are on monotherapy. There is a higher prescription of angiotensin receptor, calcium channel, beta and alfablockers in the group of patients with R-HT. There is an independent and direct relationship between R-HT and age, male gender, diabetes, obesity, metabolic syndrome, and an inverse relationship with ischemic cardiopathy. Conclusions: The prevalence of R-HT at Primary Care Units is of 13% and is related with age, male gender and metabolic risk factorsS

Reconstrucciones desde lo visual: lo arqueológico. Num. 60 Año 20 (2017) mayo-agosto. Alquimia. Sistema Nacional de Fototecas

- Editorial - La Quemada, por Ignacio Gutiérrez Ruvalcaba - Vestigios fotográficos: Los hallazgos de Francisco Plancarte en Michoacán, por Claudia Espejel Carbajal - Las exploraciones de Jorge Acosta en San Pedro Tidaá, Mixteca Alta, Oaxaca, por Ángel Iván Rivera Guzmán - Portafolio - Coleccionista de mariposas, por Vera Castillo - Reparación y Consolidación del Edificio de las Columnas en Mitla, por Leopoldo Batres - Sinafo - Soportes e imágenes, por Carlos Vázquez Olvera y María del Carmen Solanes Carraro - Reseñas, por Rebeca Monroy Nasr y Mariana Rubio de los Santos