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Present Application (present + application)
Selected AbstractsBroad Beam Ion Sources for Electrostatic Space Propulsion and Surface Modification Processes: From Roots to Present ApplicationsCONTRIBUTIONS TO PLASMA PHYSICS, Issue 7 2007H. Neumann Abstract Ion thrusters or broad beam ion sources are widely used in electrostatic space propulsion and in high-end surface modification processes. A short historical review of the roots of electric space propulsion is given. In the following, we introduce the electrostatic ion thrusters and broad beam ion sources based on different plasma excitation principles and describe the similarities as well as the differences briefly. Furthermore, an overview on source plasma and ion beam characterisation methods is presented. Apart from that, a beam profile modelling strategy with the help of numerical trajectory codes as basis for a special grid system design is outlined. This modelling represents the basis for the adaptation of a grid system for required technological demands. Examples of model validation demonstrate their reliability. One of the main challenges in improvement of ion beam technologies is the customisation of the ion beam properties, e.g. the ion current density profile for specific demands. Methods of an ex-situ and in-situ beam profile control will be demonstrated. Examples for the use of ion beam technologies in space and on earth , the RIT-10 rescue mission of ESA's satellite Artemis, the RIT-22 for BepiColombo mission and the deposition of multilayer stacks for EUVL (Extreme Ultra Violet Lithography) mask blank application are provided in order to illustrate the potential of plasma-based ion beam sources. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Clay Modified Electrodes: Present Applications and ProspectsELECTROANALYSIS, Issue 10 2003Zuzana Navrátilová Abstract This review presents the preparation and use of clay modified electrodes with emphasis on analytical applications. Besides, some investigations on ion-exchange and sorption mechanisms are outlined. Expected prospects of clay modified electrodes in the field of electrochemistry are discussed briefly. [source] Geothermal energy utilization in TurkeyINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2001G. G. Gunerhan Abstract This paper investigates the status of geothermal development in Turkey as of the end of 1999. Turkey is one of the countries with significant potential in geothermal energy. Resource assessments have been made many times by the Mineral Research and Exploration Directorate (MTA) of Turkey. The main uses of geothermal energy are mostly moderate- and low-temperature applications such as space heating and domestic hot water supply, greenhouse heating, swimming and balneology, industrial processes, heat pumps and electricity generation. The data accumulated since 1962 show that the estimated geothermal power and direct use potential are about 4500 MWe and 31 500 MWt, respectively. The direct use capacity in thermal applications is in total 640 MWt representing only 2 per cent of its total potential. Since 1990, space heating and greenhouse developments have exhibited a significant progress. The total area of greenhouses heated by geothermal energy reached up to about 31 ha with a heating capacity of 69.61 MWt. A geothermal power plant with a capacity of 20.4 MWe and a CO2 factory with a capacity of 40000 ton yr,1 have been operated in the Denizli-Kizildere field since 1984 and 1986, respectively. Ground source heat pumps have been used in residential buildings for heating and cooling for approximately 2 years. Present applications have shown that geothermal energy in Turkey is clean and much cheaper compared to the other energy sources like fossil fuels and therefore is a promising alternative. As the projects are recognized by the public, the progress will continue. Copyright © 2001 John Wiley & Sons, Ltd. [source] Advances in solid lubrication with MoS2 multilayered coatingsLUBRICATION SCIENCE, Issue 2 2001P. Voumard Abstract The general classification of solid lubricant types is reviewed, along with the reasons for choosing and methods of depositing solid lubricants, in particular MoS2. The best-performing and most flexible technique for making MoS2 films is by physical vapour deposition (PVD), and the variants of that technology are considered. The intrinsically-lubricating, lamellar structure of pure MoS2 is described, along with a brief summary of the wear and failure modes. Present applications for lubrication by MoS2 in spacecraft and dry machining are described. Anti-adhesion uses in extruding and moulding are also mentioned. The current modification of MoS2 films is by addition of dopants (co-sputtering), by multilayering as a series of films each fulfilling a specific task, or by stacking repeating nanometre-scale films. Composite films of MoS2 islands in a hard film matrix are also being developed. [source] Stability analysis of an additive spline model for respiratory health data by using knot removalJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES C (APPLIED STATISTICS), Issue 5 2009Harald Binder Summary., In many settings with possibly non-linear influence of covariates, such as in the present application with children's respiratory health data, generalized additive models are an attractive choice. Although techniques for fitting these have been extensively investigated, there are fewer results on stability of replication, i.e. stability of fitted model components with respect to perturbations in the data. Nevertheless, this aspect is essential for judging how useful the present model is for understanding predictors of lung function. We therefore investigate existing tools for stability analysis based on bootstrap samples, such as quantities for variability and bias, for our application. Furthermore, as the focus is on models based on B -splines, knot removal techniques are available. These can help to provide more insight into the stability of local features that are fitted in bootstrap samples. We analyse the bootstrap result matrix via log-linear models. Specifically, the relationship with respect to local features between the influence functions of potential lung function predictors is investigated. [source] Doppler imaging of the young late-type star LO Pegasi (BD+22°4409) in 2003 September,MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2008N. Piluso ABSTRACT A Doppler image of the zero-age main-sequence (ZAMS) late-type rapidly rotating star LO Pegasi, based on spectra acquired between 2003 September 12 and 15 is presented. The least-squares deconvolution technique is applied to enhance the signal-to-noise ratio of the mean rotational broadened line profiles extracted from the observed spectra. In the present application, an unbroadened spectrum is used as a reference, instead of a simple line list, to improve the deconvolution technique applied to extract the mean profiles. The reconstructed image is similar to those previously obtained from observations taken in 1993 and 1998, and shows that LO Peg photospheric activity is dominated by high-latitude spots with a non-uniform polar cap. The latter seems to be a persistent feature as it has been observed since 1993 with little modifications. Small spots, observed between ,10° and ,60° of latitude, appears to be different with respect to those present in the 1993 and 1998 maps. [source] Estimating the spectral indices of correlated astrophysical foregrounds by a second-order statistical approachMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2006A. Bonaldi ABSTRACT We present the first tests of a new method, the correlated component analysis (CCA) based on second-order statistics, to estimate the mixing matrix, a key ingredient to separate astrophysical foregrounds superimposed to the Cosmic Microwave Background (CMB). In the present application, the mixing matrix is parametrized in terms of the spectral indices of Galactic synchrotron and thermal dust emissions, while the free,free spectral index is prescribed by basic physics, and is thus assumed to be known. We consider simulated observations of the microwave sky with angular resolution and white stationary noise at the nominal levels for the Planck satellite, and realistic foreground emissions, with a position-dependent synchrotron spectral index. We work with two sets of Planck frequency channels: the low-frequency set, from 30 to 143 GHz, complemented with the Haslam 408 MHz map, and the high-frequency set, from 217 to 545 GHz. The concentration of intense free,free emission on the Galactic plane introduces a steep dependence of the spectral index of the global Galactic emission with Galactic latitude, close to the Galactic equator. This feature makes difficult for the CCA to recover the synchrotron spectral index in this region, given the limited angular resolution of Planck, especially at low frequencies. A cut of a narrow strip around the Galactic equator (|b| < 3°), however, allows us to overcome this problem. We show that, once this strip is removed, the CCA allows an effective foreground subtraction, with residual uncertainties inducing a minor contribution to errors on the recovered CMB power spectrum. [source] Deterministic Importance Sampling with Error DiffusionCOMPUTER GRAPHICS FORUM, Issue 4 2009László Szirmay-Kalos This paper proposes a deterministic importance sampling algorithm that is based on the recognition that delta-sigma modulation is equivalent to importance sampling. We propose a generalization for delta-sigma modulation in arbitrary dimensions, taking care of the curse of dimensionality as well. Unlike previous sampling techniques that transform low-discrepancy and highly stratified samples in the unit cube to the integration domain, our error diffusion sampler ensures the proper distribution and stratification directly in the integration domain. We also present applications, including environment mapping and global illumination rendering with virtual point sources. [source] | |||||||||||||