Examinando por Materia "Liquids"
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Ítem Imaging polarimeters based on liquid crystal variable retarders: An emergent technology for space instrumentation(SPIE-INT SOC OPTICAL ENGINEERING, 2011-01-01) Alvarez-Herrero, A.; Uribe-Patarroyo, N.; García Parejo, P.; Vargas, J.; Heredero, R.L.; Restrepo, R.; Martínez-Pillet, V.; Del Toro Iniesta, J.C.; López, A.; Fineschi, S.; Capobianco, G.; Georges, M.; López, M.; Boer, G.; Manolis, I.; Universidad EAFIT. Departamento de Ciencias Básicas; Óptica AplicadaThe use of Liquid Crystal Variable Retarders (LCVRs) as polarization modulators are envisaged as a promising novel technique for space instrumentation due to the inherent advantage of eliminating the need for conventional rotary polarizing optics hence the need of mechanisms. LCVRs is a mature technology for ground applications; they are wellknow, already used in polarimeters, and during the last ten years have undergone an important development, driven by the fast expansion of commercial Liquid Crystal Displays. In this work a brief review of the state of the art of imaging polarimeters based on LCVRs is presented. All of them are ground instruments, except the solar magnetograph IMaX which flew in 2009 onboard of a stratospheric balloon as part of the SUNRISE mission payload, since we have no knowledge about other spaceborne polarimeters using liquid crystal up to now. Also the main results of the activity, which was recently completed, with the objective to validate the LCVRs technology for the Solar Orbiter space mission are described. In the aforementioned mission, LCVRs will be utilized in the polarisation modulation package of the instruments SO/PHI (Polarimetric and Helioseismic Imager for Solar Orbiter) and METIS/COR (Multi Element Telescope for Imaging and Spectroscopy, Coronagraph). © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).Ítem Predictions of fluidities of amines by molecular simulations: TraPPE-EH vs. OPLS-AA(Elsevier B.V., 2018-05-25) Rendón-Calle A.; Orozco G.A.; Builes S.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de ProcesosAmines have several important industrial properties and commercial applications, such as gas sweetening and carbon capture; and the synthesis of: tranquilizers, decongestants, and azo dyes. For the design of many engineering applications, it is important to calculate the density and viscosity of the substances in order to determine how the fluids should be handled, stored, and discarded. In this work, the accuracy of two common force fields for amines, TraPPE-EH and OPLS-AA, was evaluated with respect to their predictions of liquid densities and fluidities for a large set of amine molecules including primary, secondary and tertiary. We propose the use of the reciprocal of viscosity, the fluidity, as a more accurate assessment of the predictions of viscosity at different temperatures. The fluidity was calculated using molecular dynamics in the isothermal-isobaric ensemble (NPT) along with the Green Kubo formalism. The simulation results were compared to available experimental information in order to provide a quantitative study of the force fields accuracy as well as their transferability to amines and thermodynamic conditions different to the ones used in their original parametrization. Overall, liquid densities and fluidities are well reproduced by the TraPPE-EH force field with absolute average deviations of 1.5% and 12%, respectively. However, important deviations were found for the OPLS-AA force field corresponding to 3.6% and 28% for density and fluidity respectively. In order to obtain better estimations of the fluidity, a temperature correction that accounts for the error in the liquid density predictions was proposed. Once the temperature correction was included the average deviation of the fluidity decreased to 10% for TraPPE-EH and to 18% for OPLS-AA. © 2018 Elsevier B.V.Ítem Scale-up from shake flasks to pilot-scale production of the plant growth-promoting bacterium Azospirillum brasilense for preparing a liquid inoculant formulation(SPRINGER, 2013-11-01) Trujillo-Roldan, Mauricio A.; Valdez-Cruz, Norma A.; Gonzalez-Monterrubio, Cesar F.; Acevedo-Sanchez, Eduardo V.; Martinez-Salinas, Carlos; Garcia-Cabrera, Ramses I.; Gamboa-Suasnavart, Ramses A.; Marin-Palacio, Luz D.; Villegas, Jesus; Blancas-Cabrera, Abel; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)Azospirillum brasilense has industrial significance as a growth promoter in plants of commercial interest. However, there is no report in the literature disclosing a liquid product produced in pilot-scale bioreactors and is able to be stored at room temperature for more than 2 years. The aim of this work was to scale up a process from a shake flask to a 10-L lab-scale and 1,000-L pilot-scale bioreactor for the production of plant growth-promoting bacterium A. brasilense for a liquid inoculant formulation. Furthermore, this work aimed to determine the shelf life of the liquid formulation stored at room temperature and to increase maize crops yield in greenhouses. Under a constant oxygen mass transfer coefficient (K L a), a fermentation process was successfully scaled up from shake flasks to 10- and 1,000-L bioreactors. A concentration ranging from 3.5 to 7.5 × 108 CFU/mL was obtained in shake flasks and bioreactors, and after 2 years stored at room temperature, the liquid formulation showed one order of magnitude decrease. Applications of the cultured bacteria in maize yields resulted in increases of up to 95 % in corncobs and 70 % in aboveground biomass. © 2013 Springer-Verlag Berlin Heidelberg.Ítem Scale-up from shake flasks to pilot-scale production of the plant growth-promoting bacterium Azospirillum brasilense for preparing a liquid inoculant formulation(SPRINGER, 2013-11-01) Trujillo-Roldan, Mauricio A.; Valdez-Cruz, Norma A.; Gonzalez-Monterrubio, Cesar F.; Acevedo-Sanchez, Eduardo V.; Martinez-Salinas, Carlos; Garcia-Cabrera, Ramses I.; Gamboa-Suasnavart, Ramses A.; Marin-Palacio, Luz D.; Villegas, Jesus; Blancas-Cabrera, Abel; Trujillo-Roldan, Mauricio A.; Valdez-Cruz, Norma A.; Gonzalez-Monterrubio, Cesar F.; Acevedo-Sanchez, Eduardo V.; Martinez-Salinas, Carlos; Garcia-Cabrera, Ramses I.; Gamboa-Suasnavart, Ramses A.; Marin-Palacio, Luz D.; Villegas, Jesus; Blancas-Cabrera, Abel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)Azospirillum brasilense has industrial significance as a growth promoter in plants of commercial interest. However, there is no report in the literature disclosing a liquid product produced in pilot-scale bioreactors and is able to be stored at room temperature for more than 2 years. The aim of this work was to scale up a process from a shake flask to a 10-L lab-scale and 1,000-L pilot-scale bioreactor for the production of plant growth-promoting bacterium A. brasilense for a liquid inoculant formulation. Furthermore, this work aimed to determine the shelf life of the liquid formulation stored at room temperature and to increase maize crops yield in greenhouses. Under a constant oxygen mass transfer coefficient (K L a), a fermentation process was successfully scaled up from shake flasks to 10- and 1,000-L bioreactors. A concentration ranging from 3.5 to 7.5 × 108 CFU/mL was obtained in shake flasks and bioreactors, and after 2 years stored at room temperature, the liquid formulation showed one order of magnitude decrease. Applications of the cultured bacteria in maize yields resulted in increases of up to 95 % in corncobs and 70 % in aboveground biomass. © 2013 Springer-Verlag Berlin Heidelberg.Ítem Space-qualified liquid-crystal variable retarders for wide-field-of-view coronagraphs(SPIE-INT SOC OPTICAL ENGINEERING, 2011-01-01) Uribe-Patarroyo, N.; Alvarez-Herrero, A.; García Parejo, P.; Vargas, J.; Heredero, R.L.; Restrepo, R.; Martínez Pillet, V.; Del Toro Iniesta, J.C.; López, A.; Fineschi, S.; Capobianco, G.; Georges, M.; López, M.; Boer, G.; Manolis, I.; Universidad EAFIT. Departamento de Ciencias Básicas; Óptica AplicadaLiquid-crystal variable retarders (LCVRs) are an emergent technology for space-based polarimeters, following its success as polarization modulators in ground-based polarimeters and ellipsometers. Wide-field double nematic LCVRs address the high angular sensitivity of nematic LCVRs at some voltage regimes. We present a work in which wide-field LCVRs were designed and built, which are suitable for wide-field-of-view instruments such as polarimetric coronagraphs. A detailed model of their angular acceptance was made, and we validated this technology for space environmental conditions, including a campaign studying the effects of gamma, proton irradiation, vibration and shock, thermo-vacuum and ultraviolet radiation. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).