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One-step Approach (one-step + approach)
Selected AbstractsA Simple, One-Step Approach to Durable and Robust Superhydrophobic Textiles,ADVANCED FUNCTIONAL MATERIALS, Issue 22 2008Jan Zimmermann Abstract Superhydrophobic textile fabrics are prepared by a simple, one-step gas phase coating procedure by which a layer of polymethylsilsesquioxane nanofilaments is grown onto the individual textile fibers. A total of 11 textile fabrics made from natural and man made fibers are successfully coated and their superhydrophobic properties evaluated by the water shedding angle technique. A thorough investigation of the commercially relevant poly(ethylene terephthalate) fabric reveals an unparalleled long-term water resistance and stability of the superhydrophobic effect. Because of the special surface geometry generated by the nanoscopic, fibrous coating on the microscopic, fibrous textiles, the coated fabric remains completely dry even after two months of full immersion in water and stays superhydrophobic even after continuous rubbing with a skin simulating friction partner under significant load. Furthermore, important textile parameters such as tensile strength, color, and haptics are unaffected by the silicone nanofilament coating. For the first time, an in-depth characterization of the wetting properties, beyond simple contact angle measurements, as well as a thorough evaluation of the most important textile parameters is performed on a superhydrophobic fabric, which reveals a true potential for application. [source] Facile One-Step Fabrication of Ordered Organic Nanowire FilmsADVANCED MATERIALS, Issue 41 2009Chengyi Zhang Squaraine nanowires self-organize into a well-ordered film through a simple solvent-evaporation process at the dichloromethane/water interface. The film can be transferred onto various substrates or stacked layer-by-layer into a multilayered structure. This one-step approach offers a low-cost method for producing scalable films of aligned organic nanowires suitable for large-scale applications. [source] Direct and indirect methods to simulate the actual evapotranspiration of an irrigated overhead table grape vineyard under Mediterranean conditionsHYDROLOGICAL PROCESSES, Issue 2 2008Gianfranco Rana Abstract Two methods, indirect and direct, for simulating the actual evapotranspiration (E) were applied to an irrigated overhead table grape vineyard during summer, situated in the Mediterranean region (south Italy), over two successive years. The first method, indirect but more practical, uses the crop coefficient (Kc) approach and requires determination of the reference evapotranspiration E0 (FAO (Food and Agriculture Organization) method). This method underestimated on average by 17% the daily values of the actual evapotranspiration E. The analysis in this paper shows that the values of Kc for the table grapes determined by the FAO method seem to not be valid in our experimental conditions. Similar conclusions can be found in the literature for the table grape cultivated under different experimental conditions and using different training systems. The second method, is a direct method for estimating the evapotranspiration. It requires development of a model for the overhead table grape vineyard E, following the Penman,Monteith one-step approach, and using standard meteorological variables as inputs for the determination of the canopy resistance. This method, which needs a particularly simple calibration, provided a better simulation of the hourly and daily evapotranspiration than the indirect method. In additon, the standard error of the daily values for the direct method ( ± 0 · 41 mm) was about 50% lower than that obtained for the indirect method, also when the indirect method used a locally calibrated coefficient Kc instead of a generic Kc. Both, for practical application and theoretical issues, the advantages and disadvantages linked to the use of each tested method are discussed in detail. Copyright © 2007 John Wiley & Sons, Ltd. [source] Investigation of a modified sequential iteration approach for solving coupled reactive transport problemsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 2 2006David J. Z. Chen Abstract When contaminants enter the soil or groundwater, they may interact physically, geochemically and biochemically with the native water, microorganisms and solid matrix. A realistic description of a reactive transport regime that includes these processes requires joint consideration of multiple chemical species. Currently there are three common numerical approaches for coupling multispecies reaction and solute transport: the one-step approach, the sequential non-iterative approach (SNIA), and the sequential iterative approach (SIA). A modification of the SNIA method is the Strang-splitting method. In this study, a new modified sequential iteration approach (MSIA) for solving multicomponent reactive transport in steady state groundwater flow is presented. This coupling approach has been applied to two realistic reactive transport problems and its performance compared with the SIA and the Strang-splitting methods. The comparison shows that MSIA consistently converges faster than the other two coupling schemes. For the simulation of nitrogen and related species transport and reaction in a riparian aquifer, the total CPU time required by MSIA is only about 38% of the total CPU time required by the SIA, and only 50% of the CPU time required by the Strang-splitting method. The test problem results indicate that the SIA has superior accuracy, while the accuracy of MSIA is marginally better than that of the Strang-splitting method. The overall performance of MSIA is considered to be good, especially for simulations in which computational time is a critical factor. Copyright © 2005 John Wiley & Sons, Ltd. [source] Grafting polymer chains bearing an N -succinimidyl activated ester end-group onto primary amine-coated silica particles and application of a simple, one-step approach via nitroxide-mediated controlled/living free-radical polymerizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 1 2010Julien Parvole Abstract In a first part, the alkoxyamine initiator derived from BlocBuilder® based on the nitroxide SG1 and bearing an N -succinimidyl ester function was used to synthesize a variety of well-defined polymers with the activated ester group at the ,-end. The grafting of those polymer chains onto primary-amine functionalized Stöber silica particles was performed in soft conditions at room temperature and was studied as a function of the polymer chain length, the type of solvent, and the concentrations of both polymer and amine. Polymer grafting densities were mainly in the 0.1,0.2 chain nm,2 range. To increase the grafting density in simple experimental conditions, a direct one-step method was then proposed: the primary-amine modified silica, the N -succinimidyl ester functionalized alkoxyamine, and the monomer were all introduced into the reaction medium at once. This technique allowed grafting and chain growth to take place simultaneously at the polymerization temperature (i.e., 120 °C for styrene), in a single step, and produced hybrid particles with very high grafting density, up to 0.9 chain nm,2, and long polymer chains. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 173,185, 2010 [source] Using glycidyl methacrylate as cross-linking agent to prepare thermosensitive hydrogels by a novel one-step methodJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 6 2008Jianping Deng Abstract A novel one-step approach is reported to prepare thermosensitive hydrogels simply by using hydroxypropyl-,-cyclodextrin (HP-,-CD)/glycidyl methacrylate (GMA)/N -isopropylacrylamide (NIPAM) system. From GMA and HP-,-CD, HP-,-CD/GMA inclusion complex was prepared and identified with NMR, FTIR, and UV-vis spectroscopies. GMA in the form of HP-,-CD/GMA complex was copolymerized with NIPAM in water with K2S2O8 as initiator, yielding hydrogels designated as poly(NIPAM-CD-GMA). The inclusion of CD in the hydrogels was confirmed by FTIR spectroscopy. The contents of CD and GMA placed considerable influence on the swelling ratio and temperature-sensitivity of the produced hydrogels. The hydrogels bearing CD moieties showed higher swelling ratio and temperature-sensitivity when compared with that without CD. The porous structure of the hydrogels containing CD was observed in the SEM images. Relevant mechanism of the ring-opening reaction of epoxide groups in GMA, the subsequent crosslinking reactions and the formation of hydrogels containing CD moieties were proposed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2193,2201, 2008 [source] A host species-informative internal control for molecular assessment of African swine fever virus infection rates in the African sylvatic cycle Ornithodoros vectorMEDICAL AND VETERINARY ENTOMOLOGY, Issue 4 2009A. D. S. BASTOS Abstract African swine fever virus (ASFV) infection in adult Ornithodoros porcinus (Murry 1877, sensuWalton 1979) ticks collected from warthog burrows in southern and East Africa was assessed using a duplex genomic amplification approach that is informative with respect to the invertebrate host species and infecting sylvatic cycle virus. DNA extracted from individual ticks was used as template for the simultaneous amplification of a C-terminal 478-bp ASFV p72 gene region and a ,313-bp fragment of the tick mitochondrial 16S rRNA gene, under optimized reaction conditions. Within-warthog burrow infection rates ranged from 0% to 43% using this approach, and phylogenetic analysis of 16S gene sequences revealed the presence of three geographically discrete O. porcinus lineages, but no support for subspecies recognition. False negatives are precluded by the inclusion of host species-informative primers that ensure the DNA integrity of cytoplasmically located genome extracts. In addition, infection rate estimates are further improved as false positives arising from carry-over contamination when performing a two-step nested polymerase chain reaction are negated by the one-step approach. Phylogenetic comparison of full-length virus gene sequences with the partial C-terminal p72 gene target confirmed the epidemiological utility of the latter in a sylvatic setting. The method is therefore of particular value in studies assessing the prevalence and diversity of ASFV in relation to the African sylvatic tick vector and holds potential for investigating the role of alternative tick species in virus maintenance and transmission. [source] | |||||||||||||