Modeling Psychrometric Data in Real-Time fruit Logistics Monitoring

Abstract Progress in fruit logistics requires an increasing number of measurements to be performed in refrigerated chambers and during transport

Effects of Gamma Irradiation on the Kinetics of the Adsorption and Desorption of Hydrogen in Carbon Microfibres

In this study, three types of carbon fibres were used, they were ex-polyacrylonitrile carbon fibres with high bulk modulus, ex-polyacrylonitrile fibres with high strength, and vapour grown carbon fibres. All the samples were subjected to a hydrogen adsorption process at room temperature in an over-pressured atmosphere of 25 bars. The adsorption process was monitored through electrical resistivity measurements. As conditioning of the fibres, a chemical activation by acid etching followed by ¿-ray irradiation with 60Co radioisotopes was performed. The surface energy was deter-mined by means of the sessile drop test. Both conditioning treatments are supplementary; the chemical activation works on the outer surface and the ¿-irradiation works in the bulk material as well. Apparently, the most significant parameter for hydrogen storage is the crystallite size. From this point of view, the mostPeer Reviewe

Transport of Chromium(VI) across a Supported Liquid Membrane Containing Cyanex 921 or Cyanex 923 Dissolved in Solvesso 100 as Carrier Phase: Estimation of Diffusional Parameters

An investigation of chromium(VI) transport across a supported liquid membrane containing the phosphine oxides Cyanex 921 and Cyanex 923 dissolved in Solvesso 100 as carrier phases was carried out in batch operation mode. Chromium(VI) transport was investigated as a function of different variables: hydrodynamic conditions in the feed (1000–1600 min) and stripping (600–1500 min) phases, HCl (0.25–2 M) and indium (0.01–0.1 g/L) concentrations in the feed phase, and carrier (0.01 M–0.75 M) concentration in the membrane phase. Indium was recovered in the stripping phase using hydrazine sulphate solutions, and, at the same time, chromium(VI) was reduced to the less harmful Cr(III) oxidation state. Models describing the transport mechanism comprising a diffusion process through the feed aqueous diffusion layer, fast interfacial chemical reaction, and diffusion of the respective chromium(VI)–phosphine oxide complexes across the membrane were developed. The equations describing the rate of transport correlate the membrane permeability coefficient with diffusion and equilibrium parameters, as well as the chemical compositions of the respective metal–carrier phases. The models were used to calculate diffusional parameters for each metal–carrier system, and the minimum thickness of the feed boundary layer was calculated as 1 × 10 cm and 6.3 × 10 cm for the Cr(VI)-Cyanex 921 and Cr(VI)-Cyanex 923 systems, respectively.The authors thank the CSIC Agency (Spain) for support

Perspectivas en el diseño de sensores a partir del conocimiento de los materiales.

Serie: Talleres Divulgativos del CENIMEl objetivo del Taller es que los asistentes reconozcan en los materiales con los que trabajan, propiedades que puedan hacer de ellos materiales sensores. El taller está dirigido a todos aquellos investigadores que tengan interés en fabricar sensores o al menos es saber algo más sobre ellos. Se describirán aspectos generales sobre los sensores y se mostrarán algunos de los logros del Laboratorio de Sensores del CENIM, en lo que se refiere a fabricación y aplicación. Se debatirá sobre experiencias e intereses particulares de los asistentes, analizando la posible aplicación y viabilidad de algunos materiales en la fabricación de sensores. Entre los logros del Laboratorio, se presentarán sensores de gases, micromecanizados en silicio, fabricados conjuntamente con el Centro Nacional de Microelectrónica del CSIC de Barcelona dentro del proyecto CICYT, “Sistema Integrado Multisensor de Silicio para la detección de gases de combustión basado en dispositivos resistivos y ópticos. MIGAS2” Igualmente se hará referencia al desarrollo de sensores capacitivos y su electrónica asociada, para medida de la humedad en madera y bambú así como sensores de nivel en silos de cemento y yeso. Finalmente, como un caso práctico de utilización de sensores comerciales, se hará una descripción muy breve de las distintas tecnologías de sensores utilizadas en la monitorización de la paila de sinterización de mineral de hierro existente en el CENIMN

Theoretical and experimental nucleation and growth of precipitates in a medium carbon-vanadium steel

Using the general theory of nucleation, the nucleation period, critical radius, and growth of particles were determined for a medium carbon V-steel. Several parameters were calculated, which have allowed the plotting of nucleation critical time vs. temperature and precipitate critical radius vs. temperature. Meanwhile, an experimental study was performed and it was found that the growth of precipitates during precipitation obeys a quadratic growth equation and not a cubic coalescence equation. The experimentally determined growth rate coincides with the theoretically predicted growth rate.We acknowledge the financial support of the Spanish CICYT (Project MAT2011-29039-C02-02).We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).Peer Reviewe

Measurements of VOCs with a semiconductor electronic nose

A semiconductor electronic nose with a sensor array of 15 elements has been fabricated by magnetron radio frequency sputtering technique for detecting various volatile organic compounds (VOCs) in a low concentration range from 50 to 250 ppm in air at 300°C. The main components of the array have been titanium oxide and tin oxide (the latter has been doped with different Pt doses) semiconductor oxides with different thicknesses. A good single classification for six tested VOCs (propanal, methyl ethyl ketone, octane, benzene, toluene, and chloroform) has been obtained from this electronic nose through the technique of principal component analysis. In general, good response times, sensitivity, and reproducibility values have been obtained for all sensors, but it is interesting to underline the sensitivity increases to these gases from sensors in which titanium oxide is used for their preparation.Peer Reviewe

Innovative processes in the production of inorganic bases and derived salts of current interest

Ammonia and sodium hydroxide are two important inorganic bases which served as the basis or precursors of other compounds with multiple uses. Some of their derived salts, i. e. ammonium nitrate, are of the paramount importance for daily life. Others salts, such as lithium carbonate, are gaining a primary role in the development of smart technologies, i. e. E-cars. This chapter described developments in the production of these useful compounds: ammonia, sodium and potassium hydroxides, related salts, i. e. ammonium nitrate, sodium and potassium carbonates, and finally, lithium carbonate.Peer reviewe

Transport of Chromium(VI) across a Supported Liquid Membrane Containing Cyanex 921 or Cyanex 923 Dissolved in Solvesso 100 as Carrier Phase: Estimation of Diffusional Parameters

An investigation of chromium(VI) transport across a supported liquid membrane containing the phosphine oxides Cyanex 921 and Cyanex 923 dissolved in Solvesso 100 as carrier phases was carried out in batch operation mode. Chromium(VI) transport was investigated as a function of different variables: hydrodynamic conditions in the feed (1000–1600 min−1) and stripping (600–1500 min−1) phases, HCl (0.25–2 M) and indium (0.01–0.1 g/L) concentrations in the feed phase, and carrier (0.01 M–0.75 M) concentration in the membrane phase. Indium was recovered in the stripping phase using hydrazine sulphate solutions, and, at the same time, chromium(VI) was reduced to the less harmful Cr(III) oxidation state. Models describing the transport mechanism comprising a diffusion process through the feed aqueous diffusion layer, fast interfacial chemical reaction, and diffusion of the respective chromium(VI)–phosphine oxide complexes across the membrane were developed. The equations describing the rate of transport correlate the membrane permeability coefficient with diffusion and equilibrium parameters, as well as the chemical compositions of the respective metal–carrier phases. The models were used to calculate diffusional parameters for each metal–carrier system, and the minimum thickness of the feed boundary layer was calculated as 1 × 10−3 cm and 6.3 × 10−4 cm for the Cr(VI)-Cyanex 921 and Cr(VI)-Cyanex 923 systems, respectively

Recent Trends in Metal Liquid-Liquid Extraction

From the first manuscript ever published about the use of any chemical procedures similar to liquid-liquid extraction (LLE) or “solvent extraction” in conjuntion with metallic compounds authored by Peligot in the XIX century, and from the two important landmarks in the XX century for uranium and copper, practically all metals had applications in LLE technology, either for their profit (valuable metals), or their removal (hazardous metals) from any tipe de aqueous solutions. This chapter put at the day recent investigations carried out from the academia, industry and research organizations about this more than known technology in the treatment of aqueous solutions containing any type of metal.Advances in Chemistry Researc

Solvent extraction in the recovery of metals from solutions: entering the third decade of XXI century

Since its first practical application in the mid-forties of XX century on the separation and purification of metals, solvent extraction had matured in this issue, being its usefulness demonstrated by the miriade of works published along the years, and by the number of solvent extraction plants built and into production around the world. Now in the XXI century, its application is moving around a theme, in connection with the above, and related to the recovery-separation–purification of metals from raw materials, as urban mining and the treatment of metal-bearing secondary materials and wastes are. Entering the third decade of XXI century, this work reviews the most advanced contribu-tions in the use of solvent extraction science on metals recovery from a variety of sources, as demanded by the social, environmental and profitability conditions in which the world is living nowadays