69 research outputs found
Comparison of different stomatal conductance algorithms for ozone flux modelling
A multiplicative and a semi-mechanistic, BWB-type [Ball, J.T., Woodrow, I.E., Berry, J.A., 1987. A model predicting stomatalconductance and its contribution to the control of photosynthesis under different environmental conditions. In: Biggens, J. (Ed.), Progress in Photosynthesis Research, vol. IV. Martinus Nijhoff, Dordrecht, pp. 221–224.] algorithm for calculating stomatalconductance (gs) at the leaf level have been parameterised for two crop and two tree species to test their use in regional scale ozone deposition modelling. The algorithms were tested against measured, site-specific data for durum wheat, grapevine, beech and birch of different European provenances. A direct comparison of both algorithms showed a similar performance in predicting hourly means and daily time-courses of gs, whereas the multiplicative algorithm outperformed the BWB-type algorithm in modelling seasonal time-courses due to the inclusion of a phenology function. The re-parameterisation of the algorithms for local conditions in order to validate ozone deposition modelling on a European scale reveals the higher input requirements of the BWB-type algorithm as compared to the multiplicative algorithm because of the need of the former to model net photosynthesis (An
Chemical ionization of phenyl n-propyl ether and methyl substituted analogs: Propene loss initiated by competing proton transfer to the oxygen atom and the aromatic ring
A chemical ionization study of deuteron transfer initiated propene loss from propoxypyridines
Modélisation des flux d’ozone en forêts pour l’évaluation des risques : état et perspectives
Efficient design methodology for inductive energy transmission
Wirelessly transferred energy for mobile devices, systems and sensors provides a huge number of advantages, which find a direct application in all areas where the connecting cable represent a development bottleneck or a mechanical, electrical and biological challenge. In the domain of consumer electronics, the wireless energy transmission can be used in order to charge laptops, tablet PCs, smart-phones and any kind of daily used mobile device which must be regularly charged. In the area of the industrial production where electronic systems are brought on mobile and articulated parts of the robots, the wireless energy transmission technology is very useful to transfer the energy on badly reachable parts by avoiding the huge problems related to twisted cable structures or galvanic contacts. Another application domain for wireless energy transmission concerns the medical devices and implants. Medical electronic devices which are used in operation rooms must be absolutely aseptic
Bis- and Oligo(trifluoromethyl)benzenes : Hydrogen/Metal Exchange Rates and Gas Phase Acidities.
Doping of Nanostructured Co<sub>3</sub>O<sub>4</sub> with Cr, Mn, Fe, Ni, and Cu for the Selective Oxidation of 2-Propanol
A series of transition-metal-substituted (M = Cr, Mn, Fe, Ni, Cu) ordered mesoporous cobalt oxide catalysts were synthesized via nanocasting method using KIT-6 silica as a hard template. While the pristine Co3O4 formed as a perfect replication of KIT-6, metal substitution resulted in less ordered and smaller domains of the replica oxides. The catalysts were applied in the selective oxidation of 2-propanol in the gas phase to reveal the role of the systematic metal substitution. Cu and Ni substitutions were found to be beneficial for the catalytic activity, while Cr, Mn, and Fe substitutions were detrimental. Cofeeding water vapor shifted the onset temperature of 2-propanol conversion to higher temperatures (ΔT = 10–20 K), while a beneficial effect was observed at high temperatures (>260 °C) decreasing deactivation by slowing the reduction of active Co3+ and/or reducing coke deposition. The activity scaled with the reducibility of the catalysts probed by H2 temperature-programmed reduction with the positive effect of a higher reducibility, indicating the crucial role of oxygen activation during 2-propanol oxidation at the gas–solid interface. 2-Propanol activation probed by adsorption/desorption experiments monitored by diffuse reflectance infrared Fourier transform spectroscopy showed a weakening of the interaction and changing of the adsorption mode from dissociative to molecular adsorption following the periodic table from Cr to Cu, suggesting that the activation of 2-propanol plays a minor role compared with oxygen activation. Fe-substituted Co3O4 was the least active catalyst due to the decrease of the number of active Co3+ sites
Structure-activity correlation in aerobic cyclohexene oxidation and peroxide decomposition over CoxFe3-xO4 spinel oxides
Sens-o-Spheres - A concept for location independent acquisition of process measurement signals
To address the problems of classical measurement methods for biotechnological processes, this paper presents a new concept for a location independent, fully autarkical, minimally disrupting measuring technique. A new device, the so called Sens-o-Spheres (Fig. 1), is introduced. Small spherical sensors with a diameter below 8 mm are brought into such processes instead of using conventional electrodes. The battery inside the sphere has to be charged wirelessly in order to avoid electrical connections. Thus, a power antenna is designed within the sphere. To be position independent during the charging process and also to increase usability, a multicoil charging pipe in combination with an intelligent control system is studied. A second antenna dedicated to the communication within the sphere is integrated in order to transmit the measured data towards an outside receiver station. After the spheres are awaked through a wake up procedure, they are applied via a handheld devic e into the predefined process (e. g. shaking flask or bioreactor) and can measure wirelessly physical and biochemical parameters like temperature
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