Incentivos para una gestión forestal sostenible y refuerzo del papel de los boques como sumideros de CO2

Publishe

Durability testing of a newly developed hydrophilic anti-soiling coating for solar reflectors

Anti-soiling coatings for solar reflectors are one of the most useful technical tools to reduce the amount of soiling accumulated on the reflector surfaces, contributing to reduce the water consumption and to increase efficiency in concentrating solar fields. A new anti-soiling coating formulation based on the hydrophilic effect has been recently developed by Tekniker and Rioglass. Reflector samples with this innovative coating were assessed through an accelerated aging test campaign as well as an outdoor exposition at the PSA by CIEMAT and DLR. According to the results obtained, the coating exhibited an appropriate behavior, which implies that the new product represents a promising solution to reduce water consumption

Terapia farmacológica después del infarto agudo de miocardio

The treatment after myocardial infarction depends on the patient risk. Daily aspirine is advised for patients at low risk. There is also a growing tendency to prescribe an "statine" in order to mantain the cholesterol level below 210 mg/dL. Estrogen therapy can be considered in post-menopausal women. Beta-blocker agents have a proved benefIt for patients at moderate risk because they reduce sudden death and reinfarction. Verapamil is an option when the beta-blocker can not be tolerated. Treatment with ACE inhibitors benefIt patients with left ventricular systolic dysfunction. Other pharmacologic agents are of unproved benefIt - eg, nitrates- or have harrnful effects --eg, nifedipine, diltiazem in patients with heart failure and cIass 1 antiarrhythmic drugs-. Only amiodarone seems to be useful for patients with severe ventricular arryhthmias.El tratamiento después del infarto depende del riesgo del paciente. Se aconseja la aspirina para los enfennos de bajo riesgo. Hay también una tendencia creciente a prescribir una "estatina" con el fIn de mantener el nivel de colesterol por debajo de los 210 mg/dL. La terapia estrogénica puede ser útil en las mujeres post-menopáusicas. Los betabloqueantes, en los pacientes de moderado riesgo, son benefIciosos puesto que reducen la muerte súbita y el reinfarto. El verapamilo puede ser una alternativa cuando el betabloqueante no es bien tolerado. Los inhibidores ECA son benefIciosos en los pacientes de alto riesgo con disfunción sistólica del ventrículo izquierdo. Otros fánnacos no son de benefIcio probado -p. ej ., los nitratos- o tienen efectos perjudiciales -p. ej ., el nifedipino, el diltiazem en los pacientes con insufIciencia cardíaca y los antiarrítmicos de clase 1- . La amiodarona es el único fármaco que puede ser útil en los pacientes con arritmias ventriculares severa

Physical modelling with experimental validation of high ductility metal cutting chip formation illustrated by copper machining

This paper addresses problems of predicting chip formation in high strain machining conditions. A complete physical model of chip formation requires both plasticity and chip/tool friction models. Friction models are commonly partly phenomenological, with friction coefficients measured from the conditions in which the models are applied. This paper's thesis is that friction emerges from the plastic response of the chip material in contact with the cutting tool. Extremely large strains are generated in the contact region. In the case of machining highly ductile metals large strains also occur in the bulk of the chip. This paper applies a Mechanical Threshold Stress plasticity model extended to high strains (equivalent strains >5) to simulating chip formation in copper machining, without assuming measured values of friction coefficients. In the case of copper machining there is not a unified source of experimental knowledge against which to validate simulations. There is a need to provide such a source. This paper reports extensive results from machining three coppers in general engineering conditions. At all cutting speeds there remains a systematic difference between the simulated and experimental chip thicknesses. In addition, at low cutting speeds an experimental observation is that chip formation cycles between low and high thicknesses. The simulations do not predict this. The experiments show the cycling to occur when the chip thickness rises to 10 or more times the uncut thickness. It is speculated with some evidence that the cycling is associated with plastic failure rather than with strain hardening, as is currently commonly given as the explanation. Modelling large strain plasticity and failure of highly ductile metals, for metal machining simulations, remains incomplete