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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 51 for “"Sieves"”.
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Synthesis, characterization and high pressure propene oligomerization over heteropoly acids, SAPO-11 molecular sieves and MeAPSO-11 molecular sieves
… acids, HPAs, and SAPO-11 and MeAPSO-11 molecular sieves have been proposed to be active for the oligomerization of propene to high quality distillate fuels. In this study these catalysts have been synthesized, characterized, modified and screened for the oligomerization of propene to distillate …
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Liquid-phase adsorption of n-paraffins on type 5A molecular sieves
… and C20) from isooctane on type 5A molecular sieves. The literature relating to molecular sieve properties and applications, and to liquid-phase adsorption of high molecular weight normal paraffin compounds by zeolites, was reviewed. Equilibrium isotherms were determined experimentally for the …
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Synthesis and characterization of novel molecular sieves containing three-membered rings
… a priori, for the synthesis of novel molecular sieves that contain three T-atom rings (three-membered rings, 3MR). Zincosilicate syntheses are performed in the presence of Group I cations. Two molar compositions of reaction mixture are investigated.
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Diversity sieves: Cultural centers as sites of successful subject production in higher education
Higher education yields individual and collective benefits, to include higher earnings, increased civic engagement, and national economic growth. While social and democratic benefits are included in the expansive lists of positive outcomes, economic benefits, both for the individual as well as for …
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Reaction of meta-diisopropylbenzene on acid molecular sieves and synthesis of zeolites by a vapor phase transport method
… propylene over the acid form of the molecular sieves SAPO-5, mordenite, offretite, beta, hexagonal and cubic faujasite (hex and FAU), L, SAPO-37, and an amorphous silica-alumina at temperatures around 463 K in a flow-type fixed-bed reactor. A small amount of cracking is observed. The main …
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Aromatization of n-hexane by platinum containing molecular sieves and distribution and motion of organic guest molecules in zeolites
… aluminophosphate (AIP0₄-5 and VPI-5) molecular sieves. ¹³C MAS NMR, TEM and H₂ chemisorption measurements reveal that Pt can be loaded into the micropores of molecular sieves with both charged and neutral frameworks. Pt containing molecular sieves were tested as catalysts for the aromatization …
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Measurements of the branchial sieve of sardine (Sardinops sagax ocellatus) from the west and south coasts of southern Africa
Branchial sieves of southern African sardine (Sardinops sagax ocellatus) were collected from three geographical regions along the southern African coast: Namibia, the south coast and the west coast of South Africa. Sardine from Namibia represented the northern Benguela upwelling ecosystem while …
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High Permeability/High Diffusivity Mixed Matrix Membranes For Gas Separations
… a polymer matrix with inorganic molecular sieves such as zeolites. The ideal filler material in MMMs should have excellent properties as a gas adsorbent or a molecular sieve, good dispersion properties in the polymer matrix of submicron thickness, and should form high quality interfaces …
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The use of enzymes in organic solvents in polytransesterification reactions
… in diethyl ether, with and without molecular sieves. It was found that molecular sieves promoted the reaction by reducing hydrolysis of the ester end-groups, resulting in polymer molecular weights between 1.2 and 2.2 times greater than those obtainable without molecular sieves. Investigations …
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Evaluating alternative macroinvertebrate sampling methodologies in wetlands: Influence of sieve mesh size on relationships between environmental and assemblage variables
… samples were washed through a series of sieves that separated invertebrates and particulate matter into four size fractions. The 6-mm fraction included material retained on the 6-mm sieve, the 4-mm fraction included material retained on both 4- and 6-mm sieves, the 2-mm size fraction …
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Binary gas adsorption on molecular sieves. Experimental data for the adsorption of oxygen, nitrogen and oxygen-nitrogen mixtures on five molecular sieve adsorbents at various temperatures and pressures and a comparison with theoretical models.
A study of adsorption equilibria of oxygen, nitrogen and oxygen-nitrogen mixtures on types 4A, 5A, 13X and Na-Mordenite molecular sieve pellets has been made. Pure component isotherms, using a volumetric apparatus, have been measured for each gas on each adsorbent at pressures up to 9 bar and for …
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Investigation of NH3 and no adsorption over Cu/SAPO-34 and Cu/AlOo3 catalysts for NH3–SCR system
… study, Copper supported on SAPO-34 molecular sieves or alumina is prepared via an incipient wetness impregnation method for ammonia selective catalytic reduction (NH_3-SCR). These NH_3-SCR catalysts are characterized by pulse chemisorption, temperature-programmed reduction (TPR), and …
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Synthesis and Characterization of Novel Adsorbent Fibers
… pillared clays, zeolites, and carbon molecular sieves. The chemically modified fibers exhibit selectivity factors as high as 4.03, which is better than values reported for pillared clays and 4A zeolites while remaining competitive with carbon molecular sieves.
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Commercialization of cryptomelane-type manganese oxide (OMS-2) nanowire paper oil sorbent
… oxide (OMS-2, a group of Octahedral Molecular Sieves) nanowire paper exhibits interesting properties: reversible wettability, oleophilic while being hydrophobic, and high thermal stability. These properties open up possible markets for commercialization. This thesis reviews the market potential …
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Arithmetic statistics and Vinberg representations
… their $Q$-invariant method to turn mod $p^2$ sieves into mod $p$ sieves. We also need to develop new methods in geometry-of-numbers. This includes a construction of ``box-shaped'' fundamental domains that allow us to count orbits in the cusp of the representation. In the second main chapter, …
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The Adsorptive Separation of Aromatic Hydrocarbon Mixtures
… of aromatic compounds using type 13X molecular sieves to achieve 0.01% aromatics in the product. The limited literature relating to the adsorption of high molecular weight aromatic compounds by zeolites was reviewed. Equilibrium isotherms were determined for typical individual aromatic …
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Element substituted aluminophosphates
… vanadium, and molybdenum into AlPO₄-5 molecular sieves, to the study of the redox properties of the resulting materials and to the potential application of these compounds in the partial oxidation of methane to methanol and formaldehyde. AlPO₄-5 molecular sieves containing Co, V, and Mo were …
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Gastrointestinal acidity, protein and starch digestibility and amino acid absorption in ruminants fed a high-concentrate diet with limestone, magnesium oxide or defluorinated phosphate
… (5.5%, 19.0% and 33.0% on 1400, 1180 and 850 µ sieves, respectively, DRP-R), 1.60% defluorinated phosphate-coarse (85% evenly among large sieves, DRP-C), 1.28% limestone or .5% MgO to study the effect of limestone or MgO on intestinal pH, DMD, starch digestibility (SD), CPD and AAD in beef …
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Synthesis and X-ray Diffraction Structures of 2-(2-thienylidene)-4,5-bis-(diphenylphosphino)-4-cyclopenten-1,3-dione and fac-BrRe(CO)3[2-(2-thienylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione]
… in dichloromethane, in the presence of molecular sieves results in a new heterocyclic compound, 2-(2-thienylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (ligand), with a high yield. This product was characterized by using both IR and NMR spectroscopic techniques and the solid-state …
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Cesium Effect: A Mild and Efficient Synthesis of Secondary and Tertiary Phosphines
… that include cesium hydroxide, molecular sieves, and DMF, at room temperature, a wide range of alkyl halides has been coupled to primary or secondary phosphines to yield secondary or tertiary phosphines. Included were activated and aliphatic halides, as well as base sensitive functional …
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