Results 1 - 10 of 113
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[en] Process for hastening the separation rate of an oil-in-water or water-in-oil emulsion, which consists in determining the HLB (hydrophobiboc-lipophobic balance) index of this emulsion and adding to it a surfactant having an opposite HLB index. Hence, in order to recuperate the uranium from phosphoric acid, pyrophosphoric acid can be used as extraction agent associated with kerosene, thereby enabling a significantly greater amount to be recuperated economically
[fr]Procede pour accelerer la vitesse de separation d'une emulsion d'huile dans l'eau ou d'eau dans l'huile qui consiste a determiner l'indice HLB (hydrophobic-lipophobic balance) de ladite emulsion et a ajouter a celle-ci un agent tensio-actif ayant un indice HLB oppose. Ainsi pour recuperer l'uranium de l'acide phosphorique on peut utiliser l'acide pyrophosphorique comme agent d'extraction associe au kerosene, ce qui permet de recuperer economiquement une quantite sensiblement plus grande d'uranium
[en] The implant Osseointegration rate depends, among other factors, on the surface´s topography and chemical composition, as in the interactions between the implant surface and cells. In this work the surface free energy for three surface treatments was calculated through contact angle measurements. For the anodic oxidized samples, a heat treatment was carried out to evaluate the influence of this process on the reduction of fluorine content. The aim of this work was study the influence of surface morphology and chemical composition on the alloy´s wettability behavior. The contact angle measurement was analyzed by the sessile drop method. The nanotubes morphology was evaluated by Field Emission Scanning Electron Microscopy (FESEM). The surface composition was analyzed by Energy Dispersive Spectroscopy (EDS). The non-photoinduced nanotubes surface free energy was higher than the polished or acid etched samples. The heat treatment lowered the F/Ti ratio in the nanotube and decreased the contact angle, increasing the interaction with the surface.
[es]La tasa de osteointegración de los implantes, entre otros factores, depende de la topografía y de la composición química de la superficie, así como de las interacciones entre la superficie del implante y las células. Con el objetivo de evaluar esta interacción, el presente trabajo evalúa la energía superficial de tres acabados superficiales a partir de la medición del ángulo de contacto. En cuanto al acabado superficial de nanotubos se ha llevado a cabo un tratamiento térmico para evaluar la influencia de este proceso en la reducción del contenido de flúor. El objetivo de este estudio es evaluar la influencia de la morfología y composición de la superficie en la mojabilidad de la aleación. La medición del ángulo de contacto se realizó empleando un goniómetro óptico. La microscopía electrónica de barrido de emisión de campo (FESEM) ha permitido realizar un estudio del diámetro y espesor de los nanotubos. El análisis de espectrometría de dispersión de energía de rayos X (EDS) se empleó para analizar la composición superficial. Como resultados, destacar que la energía superficial de los nanotubos no fotoinducidos es superior a las superficies desbastadas o grabadas con ácido. Por lo tanto, el tratamiento térmico permite reducir la ratio F/Ti en los nanotubos, reduciendo así, el ángulo de contacto e incrementando la energía superficial de los nanotubos con lo que la interacción de superficies se mejora.
[en] One approach for the fabrication of ceramic-metal composites is based on the pressureless impregnation of a porous ceramic preform by a molten metal. Molten Cu does not react with TiC and the wetting angle is close to 90o. Nonetheless, molten Cu readily impregnates partially sintered TiC preforms. A model that describes the dependence of the critical contact angle for spontaneous impregnation by molten metals in partially sintered preforms on the level of densification and on the morphology of the particles was developed. For high aspect ratios of the particles forming the preform, wetting angles close to 90o still allow impregnation by the molten metal. The results of the model were confirmed by infiltration of partially sintered TiC preforms with molten Cu and by fabrication of the TiC/Cu composites with various ceramic-to metal ratios. Decreasing of the metal content in the composite from 50 vol.% to 10 vol.% leads to a hardness increase from 250 to 1800 HV, and to the decrease of the bending strength from 960 to 280 MPa. The resistivity of these TiC/Cu composites decreases from 142 ohm cm to 25 ohm cm. (author)
[en] The Argonne research center (USA) has developed a 'super-gel' compound, a polymer close to those used in baby's diapers, which can reach a 90% efficiency in the radioactive decontamination of porous materials, like bricks or concrete. The contaminated materials are sprayed with a mixture of polymer gel and wetting agent with nano-particulates in suspension. Under the action of the wetting agent, radioactivity migrates from the pores to the gel and is trapped by the nano-particulates. The drying and recycling of the gel allows to reduce the volume of radioactive wastes. Short paper. (J.S.)
[en] DOE tank waste treatment plants, the Waste Treatment Plant (WTP) at Hanford and Defense Waste Processing Facility (DWPF) at Savannah River, are designed to vitrify radioactive waste slurries for long-term storage. Plant throughput is currently limited by the waste solids loading. To increase waste throughput rates in the plant, an increase in the slurry solids concentration (or conversely, a reduction in the mass fraction of water in the waste) is being considered. However, the present mechanical designs used to mix and transport theses slurries are limited by the rheological properties. This reduction of water results in an increase in rheological properties that challenge plant design and performance. To support this increase in throughput, there is a need to reduce the rheological properties of these waste slurries. The objective of this project is to determine a small set of well-performing and commercially available rheological modifiers that allow control rheological properties of various simulated and actual waste slurries and to understand the physical mechanisms that govern modification of waste rheology. It is estimated that processing at a higher solids concentration will reduce the operating life of these plants by one year for both facilities, representing roughly $1B in lifecycle cost savings. In addition, this research is potentially important to sustainable operations of both WTP and DWPF
[en] The corrosion product of archaeological iron objects is supposed to be removed because it causes re-corrosion. So far it is removed by scapel and sand blaster but they depend on the skill and experience of a conservator and the glass-dust of the sand blaster is harmful to humans. Therefore this study applies a laser cleaning system which is used in various industrial cleaning processes, to remove corrosion product from archaeological iron objects. In addition, this work studies the alternation of corrosion product after laser irradiation, which evaluates the reliability of the laser cleaning system. Optical microscopy, SEM-EDS, XRD, Raman have been used to observe and analyse the surface of the objects. The results show the capacity of laser cleaning some corrosion product, but blackening appears with increasing pulses and laser energy, and some corrosion products, goethite and hematite, are partially altered to magnetite. These problems, blackening and alternation of corrosion product, should be solved by further studies which find the optimal laser irradiation condition and use a wetting agent.
[en] It researches on monitoring tritium surface contamination indirectly by the measurement of wiping. It is made certain that the optimal measurement is the cooperation of nonfat gauze and saturated citric acids. And an in-depth research is done into the influence of the quantity of wetting agent, the pressure of wipe and the times of wipe. (authors)
[en] Statistical modeling imparts significant role in predicting the impact of potential factors affecting the one step fixation process of reactive printing and easy care finishing. Investigation of significant factors on tear strength of cotton fabric for single step fixation of reactive printing and easy care finishing has been carried out in this research work using experimental design technique. The potential design factors were; concentration of reactive dye, concentration of crease resistant, fixation method and fixation temperature. The experiments were designed using DoE (Design of Experiment) and analyzed through software Design Expert. The detailed analysis of significant factors and interactions including ANOVA (Analysis of Variance), residuals, model accuracy and statistical model for tear strength has been presented. The interaction and contour plots of vital factors has been examined. It has been found from the statistical analysis that each factor has an interaction with other factor. Most of the investigated factors showed curvature effect on other factor. After critical examination of significant plots, quadratic model of tear strength with significant terms and their interaction at alpha = 0.05 has been developed. The calculated correlation coefficient, R2 of the developed model is 0.9056. The high values of correlation coefficient inferred that developed equation of tear strength will precisely predict the tear strength over the range of values. (author)