The emissivity of foam-covered water surface at L-band: theoretical modeling and experimental results from the FROG 2003 field experiment

Sea surface salinity can be measured by microwave radiometry at L-band (1400–1427 MHz). This frequency is a compromise between sensitivity to the salinity, small atmospheric perturbation, and reasonable pixel resolution. The description of the ocean emission depends on two main factors: 1) the sea water permittivity, which is a function of salinity, temperature, and frequency, and 2) the sea surface state, which depends on the wind-induced wave spectrum, swell, and rain-induced roughness spectrum, and by the foam coverage and its emissivity. This study presents a simplified two-layer emission model for foam-covered water and the results of a controlled experiment to measure the foam emissivity as a function of salinity, foam thickness, incidence angle, and polarization. Experimental results are presented, and then compared to the two-layer foam emission model with the measured foam parameters used as input model parameters. At 37 psu salt water the foam-induced emissivity increase is 0.007 per millimeter of foam thickness (extrapolated to nadir), increasing with increasing incidence angles at vertical polarization, and decreasing withPostprint (published version

The Emissivity Of Foam-Covered Water Surface At L-Band: Theoretical Modeling And Experimental Results From The FROG 2003 Field Experiment

Sea surface salinity can be measured by microwave radiometry at L-band (1400-1427 MHz). This frequency is a compromise between sensitivity to the salinity, small atmospheric perturbation, and reasonable pixel resolution. The description of the ocean emission depends on two main factors: (1) the sea water permittivity, which is a function of salinity, temperature, and frequency, and (2) the sea surface state, which depends on the wind-induced wave spectrum, swell, and rain-induced roughness spectrum, and by the foam coverage and its emissivity. This study presents a simplified two-layer emission model for foam-covered water and the results of a controlled experiment to measure the foam emissivity as a function of salinity, foam thickness, incidence angle, and polarization. Experimental results are presented, and then compared to the two-layer foam emission model with the measured foam parameters used as input model parameters. At 37 psu salt water the foam-induced emissivity increase is /spl sim/0.007 per millimeter of foam thickness (extrapolated to nadir), increasing with increasing incidence angles at vertical polarization, and decreasing with increasing incidence angles at horizontal polarization.Peer Reviewe

El desarrollo municipal, factor estratégico en el posicionamiento de México en los escenarios políticos y sociales del siglo XXI

LA DEMOCRACIA COMO GOBERNABILIDAD IMPLICA, EN UN PRIMER MOMENTO, establecer una revisión periódica del papel interventor del Estado, por ser éste el principal factor de estabilidad y desarrollo democrático. En un segundo punto, de forma simultánea al estudio del papel del Estado en la conformación de un ambiente de estabilidad, crecimiento, desarrollo, orden y gobernabilidad, merece especial atención el papel y funciones cumplidas tradicionalmente por sus ámbitos de gobierno, como instancias que son fundamentales para la transición, democratización, liberalización y para la propia gobernabilidad

Enhancement in hydrophilicity of different polymer phase-inversion ultrafiltration membranes by introducing PEG/Al2O3 nanoparticles

The influence of the modification by additives in the characteristics of several ultrafiltration polymeric membranes was studied. Three asymmetric membranes with similar pore size (molecular weight cutoff (MWCO) of around 30 kDa) but different materials and pore microstructures – polysulfone, polyethersulfone and polyetherimide – were used. Effects of two different hydrophilic additives on membrane structure and the resulting performance were compared to determine the material with the best antifouling properties. Polyethyleneglycol (PEG) and alumina (Al2O3) were employed as additives in the phaseinversion method, N,N-Dimethylacetamide and deionized water were used as solvent and coagulant, respectively. Membranes were characterized in terms of hydraulic permeability, membrane resistance, MWCO profile and hydrophilicity (by membrane porosity and contact angle). The cross-sectional and membrane surface were also examined by microscopic techniques. Membrane antifouling properties were analysed by the experimental study of fouling/rinsing cycles using feed solutions of PEG of 35 kDa. Permeation and morphological studies showed that the addition of PEG/Al2O3 results in formation of a hydrophilic finger-like structure with macrovoids, whereas the addition of Al2O3 results in the formation of a hydrophilic structure with a dense top layer with Al2O3 nanoparticles and a porous sponge-like sublayer. Furthermore, polyethersulfone/PEG/Al2O3 membranes displayed superior antifouling properties and desirable ultrafiltration performance.The authors of this work thank the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation. The authors also thank the Center for Biomaterials and Tissue Engineering (Universitat Politecnica de Valencia) for contact angle measurements and BASF (Germany) and General Electric (United States) for supplying the polymers used.García Ivars, J.; Alcaina Miranda, MI.; Iborra Clar, MI.; Mendoza Roca, JA.; Pastor Alcañiz, L. (2014). Enhancement in hydrophilicity of different polymer phase-inversion ultrafiltration membranes by introducing PEG/Al2O3 nanoparticles. Separation and Purification Technology. 128:45-57. doi:10.1016/j.seppur.2014.03.012S455712

Treatment of table olive processing wastewaters using novel photomodified ultrafiltration membranes as first step for recovering phenolic compounds

Table olive processing wastewaters (TOPW) have high salt concentration and total phenolic content (TPC) causing many environmental problems. To reduce them, ultrafiltration (UF) was applied for treating TOPW. However, NaCl, which is the main responsible of salinity in TOPW, and phenols are small molecules that cannot be separated by conventional UF membranes. They have serious problems caused by fouling, which can be overcome using membrane modification techniques. For these reasons, photomodification may be an effective technique to obtain a stream rich in TPC due to the changes in membrane surface properties. UV-modification in the presence of two hydrophilic compounds (polyethylene glycol and aluminium oxide) was performed to achieve membranes with high reductions of organic matter and to keep the TPC as high as possible. Commercial polyethersulfone (PES) membranes of 30 kDa were used. Surface modification was evaluated using FTIR-ATR spectroscopy and membrane performance was studied by calculating the rejection ratios of colour, chemical oxygen demand (COD) and TPC. Results demonstrated that UF is a useful pre-treatment to reduce organic matter from TOPW, obtaining a permeate rich in TPC. PES/Al2O3 membranes displayed superior antifouling properties and rejection values, keeping high the TPC (>95%). Therefore, UF using modified membranes is an appropriate and sustainable technique for treating TOPW.The authors thank the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation. The authors also thank the Center for Biomaterials and Tissue Engineering (Universitat Politecnica de Valencia) for FTIR-ATR and contact angle measurements.García Ivars, J.; Iborra Clar, MI.; Alcaina Miranda, MI.; Mendoza Roca, JA.; Pastor Alcañiz, L. (2015). Treatment of table olive processing wastewaters using novel photomodified ultrafiltration membranes as first step for recovering phenolic compounds. Journal of Hazardous Materials. 290:51-59. doi:10.1016/j.jhazmat.2015.02.062S515929

Surface photomodification of flat-sheet PES membranes with improved antifouling properties by varying UV irradiation time and additive solution pH

Different polyethersulfone ultrafiltration membranes modified using UV irradiation in the presence of additives with different nature: hydrophilic aluminium oxide (Al2O3) nanoparticles and organic polyethylene glycol (PEG). The influence of the additive concentration, the irradiation time and the pH of the additive solution on several membrane characteristics related to its antifouling properties were investigated. These properties were analysed by means of hydrophilicity measurements (water contact angle, degree of modification, water permeability, porosity, and pore size), surface microscopic techniques (ATR-FTIR, SEM and AFM) and cross-flow filtration experiments using industrial wastewaters (residual brines from table olive processing wastewaters). Results showed that all the PES membranes modified with different PEG/Al2O3 concentrations improved the hydrophilicity of the membrane, except for membranes modified at pH 7. In addition, superior antifouling properties were provided by PES membranes modified with nano-sized Al2O3 at a concentration of 0.5%, low irradiation time (10 min) and acidic pH values (about pH 3). Therefore, surface membrane modification via UV irradiation with hydrophilic compounds is an appropriate technique to improve membrane performance applied in certain industrial fields.The authors of this work thank the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation. The authors also thank the Center for Biomaterials and Tissue Engineering and the Electron Microscopy Service both from the Universitat Politecnica de Valencia.García Ivars, J.; Iborra Clar, MI.; Alcaina Miranda, MI.; Mendoza Roca, JA.; Pastor Alcañiz, L. (2016). Surface photomodification of flat-sheet PES membranes with improved antifouling properties by varying UV irradiation time and additive solution pH. Chemical Engineering Journal. 283:231-242. doi:10.1016/j.cej.2015.07.078S23124228

Implementación de mejoras en el funcionamiento, los procesos y la evaluación de calidad de los servicios prestados por la Oficina de Movilidad Internacional.

Fac. de DerechoFALSEsubmitte

Development of fouling-resistant polyethersulfone ultrafiltration membranes via surface UV photografting with polyethylene glycol/aluminum oxide nanoparticles

Polyethersulfone ultrafiltration membranes prepared via immersion precipitation with similar pore size were modified using UV irradiation with two nano-sized hydrophilic compounds of a different nature (an organic compound and a metal oxide). Effects of PEG/Al2O3 nanoparticles on membrane structure and the resulting performance were compared to determine the material with the best antifouling properties. Membranes were characterized by hydrophilicity (water contact angle, porosity, equilibrium water content and average pore radius), surface microscopic techniques (ATR-FTIR, SEM, EDX and AFM) and cross-flow ultrafiltration experiments (hydraulic permeability, membrane resistance and antifouling measurements). Membrane antifouling properties were analyzed by several fouling/rinsing cycles using feed solutions of PEG of 35,000 g mol 1 with a concentration of 5 g L 1.Water contact angle measurements, ATR-FTIR spectra, SEM images and EDX analysis indicated the presence of PEG/Al2O3 nanoparticles on the membrane surface. All UV-grafted membranes had higher hydraulic permeability than the unmodified membrane. Furthermore, polyethersulfone membranes photografted with 2.0 wt% PEG and 0.5 wt% Al2O3 displayed superior antifouling properties and desirable performance compared to all membranes tested. Therefore, this study proved that UV photografting of PEG/Al2O3 onto membrane surfaces is an appropriate technique for modifying polyethersulfone membranes to minimize membrane fouling.The authors of this work thank the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation. The authors also thank the Center for Biomaterials and Tissue Engineering (Universitat Politecnica de Valencia) for ATR-FTIR and contact angle measurements and BASF (Germany) for supplying the polymers used.García Ivars, J.; Iborra Clar, MI.; Alcaina Miranda, MI.; Mendoza Roca, JA.; Pastor Alcañiz, L. (2014). Development of fouling-resistant polyethersulfone ultrafiltration membranes via surface UV photografting with polyethylene glycol/aluminum oxide nanoparticles. Separation and Purification Technology. 135:88-99. doi:10.1016/j.seppur.2014.07.056S889913

5to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

El V Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2019, realizado del 6 al 8 de febrero de 2019 y organizado por la Universidad Politécnica Salesiana, ofreció a la comunidad académica nacional e internacional una plataforma de comunicación unificada, dirigida a cubrir los problemas teóricos y prácticos de mayor impacto en la sociedad moderna desde la ingeniería. En esta edición, dedicada a los 25 años de vida de la UPS, los ejes temáticos estuvieron relacionados con la aplicación de la ciencia, el desarrollo tecnológico y la innovación en cinco pilares fundamentales de nuestra sociedad: la industria, la movilidad, la sostenibilidad ambiental, la información y las telecomunicaciones. El comité científico estuvo conformado formado por 48 investigadores procedentes de diez países: España, Reino Unido, Italia, Bélgica, México, Venezuela, Colombia, Brasil, Estados Unidos y Ecuador. Fueron recibidas un centenar de contribuciones, de las cuales 39 fueron aprobadas en forma de ponencias y 15 en formato poster. Estas contribuciones fueron presentadas de forma oral ante toda la comunidad académica que se dio cita en el Congreso, quienes desde el aula magna, el auditorio y la sala de usos múltiples de la Universidad Politécnica Salesiana, cumplieron respetuosamente la responsabilidad de representar a toda la sociedad en la revisión, aceptación y validación del conocimiento nuevo que fue presentado en cada exposición por los investigadores. Paralelo a las sesiones técnicas, el Congreso contó con espacios de presentación de posters científicos y cinco workshops en temáticas de vanguardia que cautivaron la atención de nuestros docentes y estudiantes. También en el marco del evento se impartieron un total de ocho conferencias magistrales en temas tan actuales como la gestión del conocimiento en la universidad-ecosistema, los retos y oportunidades de la industria 4.0, los avances de la investigación básica y aplicada en mecatrónica para el estudio de robots de nueva generación, la optimización en ingeniería con técnicas multi-objetivo, el desarrollo de las redes avanzadas en Latinoamérica y los mundos, la contaminación del aire debido al tránsito vehicular, el radón y los riesgos que representa este gas radiactivo para la salud humana, entre otros