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Original Solution (original + solution)
Selected AbstractsSonoelectrochemistry in Acoustically Emulsified Media: The Detection of LeadELECTROANALYSIS, Issue 21 2003Peter Tom Abstract The double extraction of target lead ions which are then voltammetrically quantified via acoustically assisted anodic stripping voltammetry is demonstrated. The technique involves first the extraction of lead from the aqueous volume into an organic phase containing the ligand dithizone (diphenylthiocarbazone). Second, the chelated lead is then stripped into a clean electrochemically clean aqueous solution where the lead from the original solution can be quantified. This method is shown to be applicable in electrochemically fouling media, providing a high sensitivity with a limit of detection for lead in the order of 10,7,mol,dm,3. A theoretical extraction model is presented for the optimal conditions of extraction. The technique is applied to the analysis of lead in wine samples offering quantitative data, which is in good agreement with those obtained from an independent technique (AAS). [source] Thin-Film Fabrication Method for Organic Light-Emitting Diodes Using Electrospray DepositionADVANCED MATERIALS, Issue 43 2009Jungmyoung Ju A new method for fabricating micropatterns of MEH-PPV thin films with surface roughnesses below 1nm is proposed, using electrospray deposition and a dual-solvent technique. The basic concept is that nanoparticles are deposited on the target substrate just before they become completely dry, by adding a solvent that has an evaporation speed relatively lower than that of the original solution. [source] A simple model of hillslope response for overland flow generationHYDROLOGICAL PROCESSES, Issue 17 2001Professor Carmelo Agnese Abstract This paper deals with the derivation of the hydrological response of a hillslope on the assumption of quick runoff by surface runoff generation. By using the simple non-linear storage based model, first proposed by Horton, an analytical solution of the overland flow equations over a plane hillslope was derived. This solution establishes a generalization for different flow regimes of Horton's original solution, which is valid for the transitional flow regime only. The solution proposed was compared successfully with that of Horton and, for the turbulent flow regime, to the one derived from kinematic wave theory. This solution can be applied easily to both stationary and non-stationary rainfall excess events. An analytical solution for the instantaneous response function (IRF) was also derived. Finally, simple expressions to compute peak and time to peak of IRF are proposed. Copyright © 2001 John Wiley & Sons, Ltd. [source] Concentration of aqueous dye solution by freezing and thawingTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009Kyuya Nakagawa Abstract The concentration phenomena during freezing and thawing were investigated to study the feasibility of freeze,thaw process as a concentration operation. An aqueous dye solution was employed as a model binary eutectic solution. The localised concentration in the frozen matrix was determined, and the concentration profile of the melting solution during thawing was examined. It was found that the solution obtained during thawing showed higher concentration than the original solution, and the concentration did not correspond to the amount of solute localised in the frozen matrix. It was suggested that the concentration phenomena during thawing would be governed by the melting droplet growth rate at the melting interface and by the diffusion rate of solute from eutectic phases to the droplet. On a observé le phénomène de la concentration durant le gel et le dégel afin de déterminer la faisabilité du processus de gel et de dégel en tant qu'opération de concentration. On a utilisé une solution colorante aqueuse comme solution eutectique binaire de modèle. On a déterminé la concentration localisée dans la matrice congelée et examiné le profil de concentration de la solution durant la décongélation. On a noté que la solution obtenue durant la décongélation présentait une concentration supérieure à la solution d'origine, et que la concentration ne correspondait pas à la quantité de soluté localisée dans la matrice congelée. Il a été suggéré que le phénomène de concentration durant le dégel serait régi par le taux de croissance des gouttelettes issues de la fonte à la surface et par le taux de diffusion du soluté à partir des phases eutectiques à la gouttelette. [source] Synthesis, Crystal Structure of Cis -dioxo-catecholatotungsten(VI) Complex and Its NMR Studies on the Interaction with ATPCHINESE JOURNAL OF CHEMISTRY, Issue 6 2003Lu Xiao-Ming Abstract Cis -dioxo-catecholatotungsten(VI) complex anion [W(VI)O2 -(OC6H2O)]2- was obtained with discrete protonated ethylene-diamine (NH2CH2CH2NH3)+ cations by the reaction of tetra-butyl ammonium decatungstate with catechol in the mixed solvent of CH3OH, CH3CN and ethylenediamine, and compared with its molybdenum analogue [Mo(v)O2(OC6H4O)2]3- by crystal structure, UV, EPR. The results of the UV and EPR spectra show that tungsten is less redox active than molybdenum since the molybdenum is reduced from Mo(VI) to Mo(V) but tungsten stays in the original highest oxidized state Mo (VI) when they are crystallized from the solution above. It is worthy to note that [W(VI)O2(OC6H4O2)]2- shows the same coordination structure as its molybdenum analogue in which the metal center exhibits distorted octahedral coordination geometry with two cis -dioxocatecholate ligands and might have the related coordination structure feature with the cofactor of flavoenzyme because [Mo(v)O2(OC6H4O)2]3- presented essentially the same EPR spectra as flavoenzyme. The NMR studies on the interaction of the title complex with ATP reveal that the reduction of W(VI) to W(V) occurs when the title complex is dissolved in D2O and the W (V) is oxidized again when ATP solution is mixed with original solution and the hydrolysis of the catechola-to ligand take places at mean time being monitored by 1H NMR and 13C NMR spectra. [source] Developments in Failure and Damage Modeling for UD, 2D, and 3D Composite Materials,ADVANCED ENGINEERING MATERIALS, Issue 7 2010Lucio Raimondo This paper outlines three examples of original solutions for the modeling of three classes of composite materials, which have increasing fiber architectural complexity. Results are presented from application of a novel approach for dynamic elastic and failure modeling of UD composites, and novel failure and damage modeling approaches for 2D and 3D composites, respectively. A comparison between numerical and experimental results shows that the newly proposed strategies have excellent predictive capabilities. [source] Impact of modified acidic soft drinks on enamel erosionORAL DISEASES, Issue 1 2005T Attin Objective:, To evaluate the enamel erosive potential of modified acidic soft drinks under controlled conditions in an artificial mouth. Materials and methods:, From each of 144 bovine incisors one enamel sample was prepared. Labial surfaces of the samples were ground flat, polished and covered with adhesive tape, leaving an exposed area. The samples were distributed among four (A,D) groups for treatment with A: Coca-Cola, B: Sprite; C: Sprite light, D: orange juice. Either 1.0 mmol l,1 calcium (Ca) or a combination (comb.) of 0.5 mmol l,1 calcium plus 0.5 mmol l,1 phosphate plus 0.031 mmol l,1 fluoride was added to the beverages. Samples of each group were subdivided into three subgroups (-original; -Ca and -comb.) for treatment with original and modified drinks. De- and remineralization cycles were based on a standard protocol described earlier. Surface loss of the specimens was determined using profilometry after test procedure. Results:, In all subgroups, loss of enamel was observed. The enamel loss recorded for the samples rinsed with original Sprite and original orange juice was significantly higher compared with all other solutions (P = 0.001). Lowest enamel loss was recorded for the original Coca-Cola group (P = 0.001). With the exception of Coca-Cola, demineralization with the modified beverages led to significantly lower losses compared with the respective original solutions. Conclusion:, Modification of the test soft drinks with low concentrations of calcium or a combination of calcium, phosphate and fluoride may exert a significant protective potential with respect to dental erosion. [source] Identifying and overcoming the potential barriers to the adoption of natural orifice transluminal endoscopic surgeryASIAN JOURNAL OF ENDOSCOPIC SURGERY, Issue 2 2010S. D. Schwaitzberg Abstract Natural orifice translumenal endoscopic surgery (NOTES) is an emerging innovative approach to performing minimally invasive surgical procedures. In its full potential, the concept of incisionless surgery will have mass appeal to patients. However, the barriers to adopting NOTES will have to be overcome before widespread acceptance of these techniques can occur. These potential barriers include infection, visceral leakage, difficulties in tissue manipulation, and increased cost. The history of surgical innovation has continuously overcome similar problems in other settings, and all of these potential obstacles are likely solvable. Training surgeons will be an additional barrier that will need to be overcome, but this obstacle will need to be approached differently than when laparoscopy was introduced, as standards are higher today for privileging and credentialing in most hospitals than 20 years ago. Alternative technologies that were not adopted prior to the introduction of NOTES may now appear more viable making the competitive environment more complex. Increased funding for comparative effectiveness studies and training for competency in innovation will also need original solutions, but are clearly in our patients' best interest. [source] | ||||||||||||||||