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Rough Estimation (rough + estimation)
Selected AbstractsCorrelation between sea surface topography and bathymetry in shallow shelf waters in the Western MediterraneanGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2002G. Rodríguez Velasco Summary In this paper, gravimetric and altimetric data are used to assess an estimation of the sea surface topography in the Western Mediterranean Sea. This is a complex area from different points of view, due to the presence of several islands, coastal lines, shallow waters and a peculiar hydrologic equilibrium due to its proximity to the Atlantic water exchange area. First, a gravimetric geoid was computed using the least-squares collocation (LSC) procedure with the classical remove-restore technique. We also present a local mean sea surface generated from repeat ERS-1 altimeter data fitted to TOPEX. We chose this satellite because it offers a better spatial resolution than the TOPEX data. The time span used in the computations is one year. This is a useful interval for averaging out the regular seasonal variations, which are very large in this area. We present the comparisons between the gravimetric geoidal heights and the adjusted sea surface. This is a way to obtain a rough estimation of the sea surface topography (SST) since we also include the errors in the two surfaces and other oceanic signals. The differences obtained are physically reasonable with a mean of 17 cm and standard deviation (s.d.) of 39 cm. A significant similarity is observed between the features reproduced by these differences and the bathymetry in the area, suggesting some sort of correlation between both magnitudes for the studied region. If we accept such correlation, the SST may be described as a function of depth. This procedure lets us filter out the short wavelength part of the geoid from the first SST estimation. [source] Preparation and cytotoxic properties of goethite-based nanoparticles covered with decyldimethyl(dimethylaminoethoxy) silane methiodideAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 3 2010Izolda Segal Abstract The present work describes the synthesis, physico-chemical and biological properties of the first water-soluble goethite nanoparticles covered with biologically active components: oleic acid and cytotoxic decyldimethyl(dimethylaminoethoxy)silane methiodide. The structure of initial goethite nanoparticles synthesized was proved by XRD analysis and the rough estimation of nanoparticles core size gave the value of 8 nm. The size of colloidal water-soluble nanoparticles, determined by dynamic light scattering, was within 19,35 nm. Magnetic properties and cytotoxicity (against HT-1080 and MG-22A tumor cell lines) of the nanoparticles obtained were investigated. Copyright © 2009 John Wiley & Sons, Ltd. [source] The Influence of Differences Between Microchannels on Micro Reactor PerformanceCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 3 2005E. R. Delsman Abstract Microstructured reactors most often contain a large number of micrometer-sized, parallel channels, instead of a large undivided reaction volume. Individual microchannels behave as plug-flow reactors without significant axial dispersion and with excellent heat and mass transfer properties. However, since the reaction takes place in a large number of parallel channels, it is important that all channels provide equal residence time and amount of catalyst volume. These issues depend not only on the flow distributor design, but also, for example, on the manufacturing tolerances. Correlations are derived to express the conversion of a multichannel microreactor explicitly as a function of the variance of a number of reactor parameters, viz. the channel flow rate, the channel diameter, the amount of catalyst in a channel, and the channel temperature. It is shown that the influence of flow maldistribution on the overall reactor conversion is relatively small, while the influences of variations in the channel diameter and the amount of catalyst coating are more pronounced. The model outcomes are also compared to experimental results of two microreactors with different catalyst distributions, which show that the presented method is able to provide a quick, though rough estimation of the influence of differences between channels on microreactor performance. [source] Glaucoma associated with KProsACTA OPHTHALMOLOGICA, Issue 2009K HILLE Purpose Glaucoma is one of the most serious problems in Keratoprostheses. Already glaucoma is very frequent in patients with severe changes of the ocular surface requiring keratoprosthesis surgery. About 50% of those patients have pre-existing secondary glaucoma. Preoperatively all efforts should be done to detect its presence very early on. In KPro detection of glaucoma with traditional aids is difficult. A rough estimation of the tension by digital palpation will be the only available method. All indirect clues such as the medical history of glaucoma, echographic signs of disc cupping and anterior synechiae and examination of the visual field should be considered. Methods The incidence of postoperative secondary glaucoma vary among the different kinds of prostheses according to the surgery affecting the anterior segment and the long term anatomic results. In Osteo-Odonto-Keratoprostheses (OOKP) the most vision threatening complication is a primary or secondary glaucoma, due to the extended interventions required in the anterior segment. In Boston Keratoprostheses the risk seems to be somehow less. Results As the absorption of topical anti-glaucomatous medication will not reach the inner eye because of the anatomic barrier in KPro the only promising possibilities of treatment are systemic carbonic anhydrase inhibitors, different kinds of aqueous shunts and endo-cyclo-laserphotocoagulation. Conclusion Glaucoma is still a mayor problem in KPro. PS: This lession will be presented at the KPro-Meeting!! [source] | ||||||||||