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Showing 1 to 20 of 44 for “"hydrofluoric acid"”.
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A study of the dissolution of titanium in acids with emphasis on hydrofluoric acid
… water, humid and saline atmospheres, and nitric acid. Undoubtedly such a metal will be welcome to the engineering field.</p> <p>The corrosion data on Ti available in the literature, especially on comparatively pure Ti, are rather limited. Except for two papers which were published while the …
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Electropolishing of Niobium in Sulfuric Acid-Methanol Electrolytes: Development of Hydrofluoric Acid-Free Electrolytes
… quality of Nb surface. Electropolishing (EP) in hydrofluoric acid (HF)-containing electrolytes is the currently accepted treatment process. The presence of HF is necessary for the removal of the passive oxide surface film formed in aqueous electrolytes. But HF is hazardous and must be contained …
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Influência de Recobrimento vítreo e ataque com ácido fluorídrico na topografia final da superfície Y-TZP e qualidade adesiva entre Y-TZP e cimento resinoso
… of this study was to investigate the effect of hydrofluoric acid etching and glass coating on the ceramic surface, its interaction mechanisms on the Y-TZP surface and the consequence of it on the bond strenght between ceramic and resin cement. Both treatments aim to optimize adhesion at the …
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Interfacial Electrochemistry and Surface Characterization: Hydrogen Terminated Silicon, Electrolessly Deposited Palladium & Platinum on Pyrolyzed Photoresist Films and Electrodeposited Copper on Iridium
… use of this potentiometric electrode sensor in hydrofluoric acid solution. This work is able to shows sensor function in ultra-pure water media without the need for further addition of hydrofluoric acid. This is considered a boon for the sensor due to the hazardous nature of hydrofluoric acid. …
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Evaluation of Arsenic and Selenium Quantitation in Marcellus Shales and Flowback Saline Waters using Thiol Cotton Fibre-Graphite Furnace Atomic Absorption Spectroscopy and Diffusive Gradient in Thin Film Techniques
… time is also reported.;In addition, the role of hydrofluoric acid in microwave-assisted digestion and in the elimination of spectral interferences from the aluminum matrix at 189 nm for arsenic quantitation by GFAAS with deuterium lamp back-ground correction has been investigated. When sufficient …
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Phase transitions in superionic PbSnF₄
… different conditions: (i) versus the amount of hydrofluoric acid used for the preparation by the aqueous route, (ii) upon application of mechanical energy, and (iii) versus temperature. The addition of an aqueous solution of lead(II) nitrate to a fresh aqueous solution of SnF$\sb2$ results in …
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Use of a Synthetic Substrate for Orthodontic Bond Strength Testing
… premolar. The groups tested were: Group 1: acid-etched with 9.6% hydrofluoric acid (HFA) for 60 seconds; Group 2: acid-etched with 9.6% HFA for 90 seconds; Group 3: acid-etched with 9.6% HFA for 120 seconds; Group 4: surface roughened with silicon carbide (Sic); and control group: human …
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DEVELOPMENT AND APPLICATION OF MINIATURIZED SAMPLE PREPARATION TECHNIQUES COMBINED WITH GAS CHROMATOGRAPHY-MASS SPECTROMETRY IN ENVIRONMENTAL ANALYSIS
… on similar concept as plunger-in-needle SPME. A hydrofluoric acid-etched stainless steel plunger was used as organic solvent holder and support. The aforementioned miniaturized and environmentally friendly sample preparation methods were demonstrated to be simple, fast and cost-effective for the …
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Engineering mesoporous silicon for cell biology applications
… electric potential is applied to silicon using a hydrofluoric acid electrolyte. The structure of porous silicon is of interest for cell biological applications due to the large surface area and optical properties. To render the material biocompatible we modify porous silicon using hydrosilylation …
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Characteristics and mechanisms of atrazine sorption to biochar for land remediation
… kinetics, isotherms and interactions with humic acids showed that for all biochars in this study, pore filling was a significant process through which atrazine is transported to adsorption sites, although poor intraparticle diffusion for softwood and oil seed rape biochars can prevent efficient …
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Study of Pore Development in Silicon Oxycarbide Ceramics to Understand the Microstructural Evolution
… ceramics through either etching the SiOC with hydrofluoric acid, which removes the silicon dioxide and produces pores with diameters less than 20 nanometers, or through decomposition during heating of a certain polymer in a two polymer mixture, producing pores that are dozens of microns in …
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Counterfactuals, dispositions, and conscious experience : essays on entropy
… robust dispositions. Drop an ordinary rock into hydrofluoric acid, and-almost no matter what is going on far away--it will dissolve. In other words, the rock displays a disposition to dissolve that is robust with respect to small variations in its environment. Why is it that so many objects …
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Three-dimensional nanostructures fabricated by stacking pre-patterned monocrystalline silicon nanomembranes
… thin layer of silicon on glass were released in hydrofluoric acid where surface tension caused them to float flat. Their fragility inspired novel handling and position manipulation techniques for layer-to-layer alignment. While exploiting surface tension allowed membranes to be stacked using …
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Polarization, passivation, intercalation, and generation: an examination of In-Situ and Ex-Situ analytical techniques for the study of carbon anode materials for the electrochemical generation of elemental fluorine.
… difficulty and hazards surrounding the use of hydrofluoric acid (HF) and fluorine gas. This work examines various carbon materials for their use as electrodes in the electrochemical generation of elemental fluorine. An experimental apparatus was designed and constructed to melt and maintain the …
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The Performance of Silicon Based Sensor and its Application in Silver Toxicity Studies
… detect part per trillion ionic silver in 0.0098% hydrofluoric acid based on the open circuit potential (OCP) measurement. The OCP jump of 100 ppt ionic silver solution is up to 120 mV. The complex agent can effectively suppress the ionic silver concentration and suppress the OCP signal. The …
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Fabrication of three-dimensional nanostructures for thermal study
… Subsequent etching with dilute ethanolic hydrofluoric acid yielded periodic three-dimensional polycrystalline silicon nanostructures with characteristic skeleton size of around 20 nanometers. Using a similar colloidal crystal template made of 400 nanometer sized silica nanoparticles, …
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Surface and interface characterisation of high-k dielectric materials on silicon and III-V semiconductor substrates
… surface preparation included flash cleaning, hydrofluoric acid (HF) etching and the growth of self limiting ultra-thin oxides. For InGaAs the optimisation of the ammonium sulphide (NH4)2S and hydrogen sulphide (H2S) passivation treatments was investigated and an in-depth study of atomic …
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Porous Silicon as Broadband Antireflector for Photovoltaic Application.
… by electrochemical anodization of silicon in hydrofluoric acid, but the main disadvantage is that HF is highly toxic and corrosive, which limits its use in industrial applications. So, there is a need for a cost-effective and non-toxic anodization technique to obtain highly ordered (diameter, …
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Alternative passivation for silicon (100), environmentally benign manufacturing, and cooperative strategy in semiconductor industry
… cleaned by IBM's conventional RCA and dilute hydrofluoric acid last clean without compromising its reliability. Furthermore, particle count results shown that this MeO-Si has the same particle resistance as H-Si. Further mechanistic and thermodynamic studies are performed such that this …
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Fabrication of critical-angle transmission gratings for high efficiency x-ray spectroscopy
… grating stiction problem during wet hydrofluoric acid (HF) release is analyzed using finite element modeling (FEM) of a thin grating plane between support structures on top of oxide in compressive stress. I successfully fabricated the CAT gratings with 574 and 200 nm periods, which …
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