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Showing 1 to 20 of 40 for “"Nitrogen Adsorption"”.
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THE MICROSTRUCTURES OF ESTUARINE PARTICLES
… and Restronguet Creek was carried out using a nitrogen adsorption technique. The surface areas and porosities of the particles were determined using BET theory and capillary models applied to the gas adsorption isotherms. The surface areas of the suspended particles collected on axial transects …
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Morphology-Property Relationships in Semicrystalline Aerogels of Poly(ether ether ketone)
… by SAXS and high surface areas as determined by nitrogen adsorption methods. Surface area values determined from SAXS data were consistently higher than that measured directly using nitrogen adsorption, suggesting that pore densification diminishes the accessible aerogel surface area.
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Preparation, Evaluation and Structural Modeling of Carbon-Based Adsorbents Used on Natural Gas Vehicles
… volumetric methane storage capacity. Modeling of nitrogen and methane adsorption onto a porous carbon is also conducted to optimize its pore structure and maximize its methane storage capacity. A novel analytical 3-D model is developed to calculate the pore size distribution for porous materials …
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ΜΕΛΕΤΗ ΤΗΣ ΑΠΟΔΡΑΣΤΙΚΟΠΟΙΗΣΗΣ ΚΑΤΑΛΥΤΩΝ ΚΑΤΑ ΤΗΝ ΥΔΡΟΓΟΝΟΑΠΟΘΕΙΩΣΗ ΥΠΟΛΕΙΜΜΑΤΩΝΑΠΟΣΤΑΞΗΣ ΑΡΓΟΥ ΠΕΤΡΕΛΑΙΟΥ ΘΑΣΟΥ
… NI) DEPOSITS WITH RESPECT TO OPERATING TIME. THE NITROGEN ADSORPTION-CAPILLARY CONDENSATION AND THE MERCURY DOROSIMETRY TECHNIQUES WERE APPLIED TO DETERMINE PORE VOLUME DISTRIBUTIONS AND SPECIFIC SURFACE AREAS OFCATALYST SAMPLES BEFORE AND AFTER USE AS WELL AS AFTER CATALYST REGENERATION. C/H …
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Application of carbonated calcium silicate materials in metal sorption processes
… silicate, which were carbonated, and examined by nitrogen adsorption, XRD, NMR, SEM, TG-DTA analytical techniques. The carbonated materials were evaluated in batch sorption studies with the solutions of cadmium, lead, nickel, cobalt, zinc, strontium and cesium. The findings of the structural …
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Novel mesoporous silicates as indoor air pollutant scavengers
… microscopy, scanning electron microscopy, nitrogen adsorption and elemental analysis. Sorbents were selected for adsorption efficiency testing based on the characterisation results. The synthesised mesoporous sorbent VOC and formaldehyde adsorption efficiencies were then compared with …
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Using oscillations to detect capillary condensation in MCM-41
… to the onset of capillary condensation from nitrogen adsorption isotherm in MCM-41 is 0.91 nm. This agrees with the measurement made using our spring-mass system, because the onset of capillary condensation estimated using this pore size is close to the onset observed from our experiment. …
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Studies of the surface and bulk reactivity of calcium hydroxide
… Spectroscopy, Thermo-Gravimetric Analysis, Nitrogen Adsorption, Water Adsorption, Scanning Electron Microscopy and Microprobe Analysis. From this slight differences in the 'fresh' samples were found to be due to various degrees of atmospheric ageing. The main process involved in the ageing …
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Catalytic Reactions of Highly Conjugated Polymers: the Removal of Nitrogen Monoxide from Gas Streams using Pyrolysed Polyacrylonitrile
… as a heterogeneous catalyst for the removal of nitrogen monoxide from motor vehicle exhaust gas. Previous work had shown that the polymer was capable of removing nitro-gen monoxide from gas streams and it was intended to optimise the activity of the polymer and to investigate the nature of the …
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Synthesis and Characterization of Novel Adsorbent Fibers
… spectroscopy, thermal gravimetric analysis, and nitrogen/carbon dioxide adsorption. Their performance as efficient ion exchange systems was evaluated through pressure drop, capacity and dynamic mode kinetic measurements. Total ion exchange capacities up to 19.5 meq/g were measured for the fibers …
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Zur elektrochemischen Oxidation des Ammoniak
… the electrochemical oxidation is effected by nitrogen adsorption at the electrodes. Some mediators such as Mn(II)/Mn(III), Cu(I)/Cu(II) or 2,2,6,6-Tetrametyl-piperidinyl-1-oxyl-Radikal (TEMPO) have been studied by CV for their ability to prevent this effect. Only for TEMPO a positive effect on …
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Catalytic membrane reactor-separator for environmental applications.
… electron microscopy, energy diffraction X-ray, nitrogen adsorption and gas permeation. In the first part of this work, CO2 permeance (3.39 x 10-8 mol m-2 s-1 Pa-1 at 25 0C for γ-Al2O3 membrane after exposing boehmite to the support) was mainly attributed to the Knudsen diffusion mechanism. …
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Fabrication and characterization of hollow silica aerogel spheres using sol-gel processing in the dual nozzle generation system
… medium (which consisted of either ammonia and nitrogen gas or ammonium hydroxide), and the dimensions and relative positions of the nozzles used for the droplet generation. A detailed study designed to understand and control the kinetics of the sol-gel processing that is responsible for the …
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Synthesis and Characterization of Nanoporous Copolymers with Potential Gas Storage Applications
… phenyl maleimide, were investigated using nitrogen sorption/desorption isotherms at 77 K and molecular simulations. These alternating copolymers were found to have Brunauer-Emmett-Teller (BET) surface areas in the range of 20-40 m2/g. Surface areas of these alternating copolymers increased …
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Thermodynamic and transport properties of self-assembled monolayers from molecular simulations
… canonical MC simulations are employed to obtain nitrogen adsorption isotherms for unmodified and modified MCM-41 material models. Furthermore, the density profiles of alkyl chains and nitrogen molecules are analyzed to clarify the differences in the adsorption mechanisms in unmodified and …
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Hydrogen Storage in Metal Fragments grafted Silicas and Chromium Hydrazide Gels
… storage capacities, and characterized by XRD, nitrogen adsorption, XPS, and EA. The effects of the variation in the surface area, pore size, transition metal type, and metal oxidation state, the organometallic loading levels, as well as the ligand environment on the H2 adsorption capacity and …
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Catalytic and adsorbent properties of solid acid catalysts studied by ammonia adsorption microcalorimetry
… diameters, pore volumes, and crystallinity from nitrogen adsorption, powder x-ray diffraction, cation exchange capacity, and elemental analysis. The acidity of these catalysts has been studied by NH3 adsorption microcalorimetry. NH3 is assumed to adsorb stoichiometrically on surface acid sites …
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Carbon Coating for Improved Hydrothermal Stability of Silica Supports
… were FTIR, DRIFT, TGA, TEM, STEM, EFTEM, HRTEM, nitrogen adsorption surface area analysis, and hydrothermal treatments. This study successfully showed carbon from different precursors could be bound to the surface of Stober spheres, a model silica support, and to the surface and within the pores …
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Polymers from the natural product betulin : a microstructural investigation
… for the analysis of porous substances like nitrogen sorption at 77 K do not seem to be sufficient to answer all arising questions about the microstructure of such materials. In this thesis, microporous polymers from an abundant natural resource, betulin, will be presented. Betulin is a …
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Geothermal energy : silica precipitation and utilization
… silica is the low specific surface area but the nitrogen adsorption investigation revealed a BET of only 4.4 m2 g−1, which is considerably lower than that of the silica used in most applications. Future research should include some investigations on what causes the low surface area and if it can …
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