993 resultados para ti-modified columbite route
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A differential pulse voltammetric sensor for the determination of tamsulosin hydrochloride (TAM) using multiwalled carbon nanotubes (MWNTs)–Nafion-modified glassy carbon electrode (GCE) has been developed. MWNTs were dispersed in water with the help of Nafion and were used to modify the surface of GCE via solvent evaporation. At MWNT-modified electrode, TAM gave a well-defined oxidation peak at a potential of 1084 mV in 0.1 M acetate buffer solution of pH 5. Compared to the bare electrode, the peak current of TAM showed a marked increase and the peak potential showed a negative deviation. The determination conditions, such as the amount of MWNT–Nafion suspension, pH of the supporting electrolyte and scan rate, were optimised. Under optimum conditions, the oxidation peak current was proportional to the concentration of TAM in the range 1 × 1023 M–3 × 1027 M with a detection limit of 9.8 × 1028 M. The developed sensor showed good stability, selectivity and was successfully used for the determination of TAM in pharmaceutical formulations and urine samples
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A nanocomposite is a multiphase solid material where one of the phases has one, two or three dimensions of less than 100 nanometers (nm), or structures having nano-scale repeat distances between the different phases that make up the material. In the broadest sense this definition can include porous media, colloids, gels and copolymers, but is more usually taken to mean the solid combination of a bulk matrix and nano-dimensional phase(s) differing in properties due to dissimilarities in structure and chemistry. The mechanical, electrical, thermal, optical, electrochemical, catalytic properties of the nanocomposite will differ markedly from that of the component materials. Size limits for these effects have been proposed, <5 nm for catalytic activity, <20 nm for making a hard magnetic material soft, <50 nm for refractive index changes, and <100 nm for achieving superparamagnetism, mechanical strengthening or restricting matrix dislocation movement. Conducting polymers have attracted much attention due to high electrical conductivity, ease of preparation, good environmental stability and wide variety of applications in light-emitting, biosensor chemical sensor, separation membrane and electronic devices. The most widely studied conducting polymers are polypyrrole, polyaniline, polythiophene etc. Conducting polymers provide tremendous scope for tuning of their electrical conductivity from semiconducting to metallic region by way of doping and are organic electro chromic materials with chemically active surface. But they are chemically very sensitive and have poor mechanical properties and thus possessing a processibility problem. Nanomaterial shows the presence of more sites for surface reactivity, they possess good mechanical properties and good dispersant too. Thus nanocomposites formed by combining conducting polymers and inorganic oxide nanoparticles possess the good properties of both the constituents and thus enhanced their utility. The properties of such type of nanocomposite are strongly depending on concentration of nanomaterials to be added. Conducting polymer composites is some suitable composition of a conducting polymer with one or more inorganic nanoparticles so that their desirable properties are combined successfully. The composites of core shell metal oxide particles-conducting polymer combine the electrical properties of the polymer shell and the magnetic, optical, electrical or catalytic characteristics of the metal oxide core, which could greatly widen their applicability in the fields of catalysis, electronics and optics. Moreover nanocomposite material composed of conducting polymers & oxides have open more field of application such as drug delivery, conductive paints, rechargeable batteries, toners in photocopying, smart windows, etc.The present work is mainly focussed on the synthesis, characterization and various application studies of conducting polymer modified TiO2 nanocomposites. The conclusions of the present work are outlined below, Mesoporous TiO2 was prepared by the cationic surfactant P123 assisted hydrothermal synthesis route and conducting polymer modified TiO2 nanocomposites were also prepared via the same technique. All the prepared systems show XRD pattern corresponding to anatase phase of TiO2, which means that there is no phase change occurring even after conducting polymer modification. Raman spectroscopy gives supporting evidence for the XRD results. It also confirms the incorporation of the polymer. The mesoporous nature and surface area of the prepared samples were analysed by N2 adsorption desorption studies and the mesoporous ordering can be confirmed by low angle XRD measurementThe morphology of the prepared samples was obtained from both SEM & TEM. The elemental analysis of the samples was performed by EDX analysisThe hybrid composite formation is confirmed by FT-IR spectroscopy and X-ray photoelectron spectroscopyAll the prepared samples have been used for the photocatalytic degradation of dyes, antibiotic, endocrine disruptors and some other organic pollutants. Photocatalytic antibacterial activity studies were also performed using the prepared systemsAll the prepared samples have been used for the photocatalytic degradation of dyes, antibiotic, endocrine disruptors and some other organic pollutants. Photocatalytic antibacterial activity studies were also performed using the prepared systems Polyaniline modified TiO2 nanocomposite systems were found to have good antibacterial activity. Thermal diffusivity studies of the polyaniline modified systems were carried out using thermal lens technique. It is observed that as the amount of polyaniline in the composite increases the thermal diffusivity also increases. The prepared systems can be used as an excellent coolant in various industrial purposes. Nonlinear optical properties (3rd order nonlinearity) of the polyaniline modified systems were studied using Z scan technique. The prepared materials can be used for optical limiting Applications. Lasing studies of polyaniline modified TiO2 systems were carried out and the studies reveal that TiO2 - Polyaniline composite is a potential dye laser gain medium.
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In this venture three distinct class of catalysts such as, pillared clays and transition metal loaded pillared clays , porous clay heterostructures and their transition metal loaded analogues and DTP supported on porous clay heterostructures etc. were prepared and characterized by various physico chemical methods. The catalytic activities of prepared catalysts were comparatively evaluated for the industrially important alkylation, acetalization and oxidation reactions.The general conclusions drawn from the present investigation are Zirconium, iron - aluminium pillared clays were synthesized by ion exchange method and zirconium-silicon porous heterostructures were Summary and conclusions 259 prepared by intergallery template method. Transition metals were loaded in PILCs and PCHs by wet impregnation method. Textural and acidic properties of the clays were modified by pillaring and post pillaring modifications. The shift in 2θ value to lower range and increase in d (001) spacing indicate the success of pillaring process. Surface area, pore volume, average pore size etc. increased dramatically as a result of pillaring process. Porous clay heterostructures have higher surface area, pore volume, average pore diameter and narrow pore size distribution than that of pillared clays. The IR spectrum of PILCs and PCHs are in accordance with literature without much variation compared to parent montmorillonite which indicate that basic clay structure is retained even after modification. The silicon NMR of PCHs materials have intense peaks corresponding to Q4 environment which indicate that mesoporous silica is incorporated between clay layers. Thermo gravimetric analysis showed that thermal stability is improved after the pillaring process. PCH materials have higher thermal stability than PILCs. In metal loaded pillared clays, up to 5% metal species were uniformly dispersed (with the exception of Ni) as evident from XRD and TPR analysis. Chapter 9 260 Impregnation of transition metals in PILCs and PCHs enhanced acidity of catalysts as evident from TPD of ammonia and cumene cracking reactions. For porous clay heterostructures the acidic sites have major contribution from weak and medium acid sites which can be related to the Bronsted sites as evident from TPD of ammonia. Pillared clays got more Lewis acidity than PCHs as inferred from α- methyl styrene selectivity in cumene cracking reaction. SEM images show that layer structure is preserved even after modification. Worm hole like morphology is observed in TEM image of PCHs materials In ZrSiPCHS, Zr exists as Zr 4+ and is incorporated to silica pillars in the intergallary of clay layers as evident from XPS analysis. In copper loaded zirconium pillared clays, copper exists as isolated species with +2 oxidation state at lower loading. At higher loading, Cu exists as clusters as evident from reduction peak at higher temperatures in TPR. In vanadium incorporated PILCs and PCHs, vanadium exist as isolated V5+ in tetrahedral coordination which is confirmed from TPR and UVVis DRS analysis. In cobalt loaded PCHs, cobalt exists as CoO with 2+ oxidation state as confirmed from XPS. Cerium incorporated iron aluminium pillared clay was found to be the best catalyst for the hydroxylation of phenol in aqueous media due to the additional surface area provided by ceria mesopores and its redox properties. Summary and conclusions 261 Cobalt loaded zirconium porous clay heterostructures were found to be promising catalyst for the tertiary butylation of phenol due to higher surface area and acidic properties. Copper loaded pillared clays were found to be good catalyst for the direct hydroxylation of benzene to phenol. Vanadium loaded PCHs catalysts were found to be efficient catalysts for oxidation of benzyl alcohol. DTP was firmly fixed on the mesoporous channels of PCHs by Direct method and functionalization method. DTP supported PCHs catalyst were found to be good catalyst for acetalization of cyclohexanone with more than 90% conversion.
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"Funktionelle Analyse der LC-FACS in Dictyostelium discoideum" Das Dictyostelium discoideum Gen fcsA kodiert für ein 75 kDa großes Protein. Es kann durch Homologieanyalysen der Amino-säuresequenz zu den "long-chain fatty acyl-CoA"-Synthetasen ge-rechnet werden, die lang-kettige Fettsäuren durch die kovalente Bindung von Coenzym A akti-vie-ren und damit für diverse Reak-tionen in Stoffwechsel und Molekül-Synthese der Zelle verfügbar machen. Die hier untersuchte D. discoideum LC-FACS lokalisiert als peripher assoziiertes Protein an der cytosolischen Seite der Membran von Endo-somen und kleiner Vesikel. Bereits kurz nach der Bildung in der frühen sauren Phase kann die Lokalisation der LC-FACS auf Endosomen ge-zeigt werden. Sie dissoziiert im Laufe ihrer Neutra-li-sierung und kann auf späten Endosomen, die vor ihrer Exocytose stehen nicht mehr nach-gewiesen werden. Ein Teil der kleinen die in der gesamte Zelle verteilten kleinen Vesikel zeigt eine Kolokalisation mit lysosomalen Enzymen. Trotz des intrazellulären Verteilungs-mus-ters, das eine Beteiligung dieses Pro-teins an der Endocytose nahe-legt, konnte kein signifikanter Rückgang der Pino- und Phagocytose-Rate in LC-FACS Nullmutanten beobachtet werden. Der endo-cy-to-ti-sche Transit ist in diesen Zellen etwas verlängert, außerdem zeigen die Endosomen einen deutlich erhöhten pH-Wert, was zu einer weniger effektiven Prozessierung eines lysosomalen Enzyms führt (a-Mannosidase). Die Funktion der LC-FACS ist die Aufnahme von langkettigen Fettsäuren aus dem Lumen der Endosomen.
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Using Doppler-free two-photon absorption spectroscopy, we have measured hyperfine splitting constants as well as isotopic level shifts of the 6s^2 np ^2 P_l/2,3/2 states in (n=7-10) in ^203 TI and ^205 TI. Calculations for hyperfine constants and electron density at the nucleus have been performed by the Dirac-Fock method. The experimental results are compared with these calculations as well as with the predictions of the semiempirical theory.
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Die laserinduzierte Plasmaspektroskopie (LIPS) ist eine spektrochemische Elementanalyse zur Bestimmung der atomaren Zusammensetzung einer beliebigen Probe. Für die Analyse ist keine spezielle Probenpräparation nötig und kann unter atmosphärischen Bedingungen an Proben in jedem Aggregatzustand durchgeführt werden. Femtosekunden Laserpulse bieten die Vorteile einer präzisen Ablation mit geringem thermischen Schaden sowie einer hohen Reproduzierbarkeit. Damit ist fs-LIPS ein vielversprechendes Werkzeug für die Mikroanalyse technischer Proben, insbesondere zur Untersuchung ihres Ermüdungsverhaltens. Dabei ist interessant, wie sich die initiierten Mikrorisse innerhalb der materialspezifschen Struktur ausbreiten. In der vorliegenden Arbeit sollte daher ein schnelles und einfach zu handhabendes 3D-Rasterabbildungsverfahren zur Untersuchung der Rissausbreitung in TiAl, einer neuen Legierungsklasse, entwickelt werden. Dazu wurde fs-LIPS (30 fs, 785 nm) mit einem modifizierten Mikroskopaufbau (Objektiv: 50x/NA 0.5) kombiniert, welcher eine präzise, automatisierte Probenpositionierung ermöglicht. Spektrochemische Sensitivität und räumliches Auflösungsvermögen wurden in energieabhängigen Einzel- und Multipulsexperimenten untersucht. 10 Laserpulse pro Position mit einer Pulsenergie von je 100 nJ führten in TiAl zum bestmöglichen Kompromiss aus hohem S/N-Verhältnis von 10:1 und kleinen Lochstrukturen mit inneren Durchmessern von 1.4 µm. Die für das Verfahren entscheidende laterale Auflösung, dem minimalen Lochabstand bei konstantem LIPS-Signal, beträgt mit den obigen Parametern 2 µm und ist die bislang höchste bekannte Auflösung einer auf fs-LIPS basierenden Mikro-/Mapping-Analyse im Fernfeld. Fs-LIPS Scans von Teststrukturen sowie Mikrorissen in TiAl demonstrieren eine spektrochemische Sensitivität von 3 %. Scans in Tiefenrichtung erzielen mit denselben Parametern eine axiale Auflösung von 1 µm. Um die spektrochemische Sensitivität von fs-LIPS zu erhöhen und ein besseres Verständnis für die physikalischen Prozesse während der Laserablation zu erhalten, wurde in Pump-Probe-Experimenten untersucht, in wieweit fs-Doppelpulse den laserinduzierten Abtrag sowie die Plasmaemission beeinflussen. Dazu wurden in einem Mach-Zehnder-Interferometer Pulsabstände von 100 fs bis 2 ns realisiert, Gesamtenergie und Intensitätsverhältnis beider Pulse variiert sowie der Einfluss der Materialparameter untersucht. Sowohl das LIPS-Signal als auch die Lochstrukturen zeigen eine Abhängigkeit von der Verzögerungszeit. Diese wurden in vier verschiedene Regimes eingeteilt und den physikalischen Prozessen während der Laserablation zugeordnet: Die Thermalisierung des Elektronensystems für Pulsabstände unter 1 ps, Schmelzprozesse zwischen 1 und 10 ps, der Beginn des Abtrags nach mehreren 10 ps und die Expansion der Plasmawolke nach über 100 ps. Dabei wird das LIPS-Signal effizient verstärkt und bei 800 ps maximal. Die Lochdurchmesser ändern sich als Funktion des Pulsabstands wenig im Vergleich zur Tiefe. Die gesamte Abtragsrate variiert um maximal 50 %, während sich das LIPS-Signal vervielfacht: Für Ti und TiAl typischerweise um das Dreifache, für Al um das 10-fache. Die gemessenen Transienten zeigen eine hohe Reproduzierbarkeit, jedoch kaum eine Energie- bzw. materialspezifische Abhängigkeit. Mit diesen Ergebnissen wurde eine gezielte Optimierung der DP-LIPS-Parameter an Al durchgeführt: Bei einem Pulsabstand von 800 ps und einer Gesamtenergie von 65 nJ (vierfach über der Ablationsschwelle) wurde eine 40-fache Signalerhöhung bei geringerem Rauschen erzielt. Die Lochdurchmesser vergrößerten sich dabei um 44 % auf (650±150) nm, die Lochtiefe um das Doppelte auf (100±15) nm. Damit war es möglich, die spektrochemische Sensitivität von fs-LIPS zu erhöhen und gleichzeitig die hohe räumliche Auflösung aufrecht zu erhalten.
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Soil microorganisms have evolved two possible mechanisms for their uptake of organic N: the direct route and the mobilization-immobilization-turnover (MIT) route. In the direct route, simple organic molecules are taken up via various mechanisms directly into the cell. In the MIT route, the deamination occurs outside the cell and all N is mineralized to NH4+ before assimilation. A better understanding of the mechanisms controlling the different uptake routes of soil microorganisms under different environmental conditions is crucial for understanding mineralization processes of organic material in soil. For the first experiment we incubated soil samples from the long term trial in Bad Lauchstädt with corn residues with different C to N ratios and inorganic N for 21 days at 20 °C. Under the assumption that all added amino acids were taken up or mineralized, the direct uptake route was more important in soil amended with corn residues with a wide C to N ratio. After 21 days of incubation the direct uptake of added amino acids increased in the order addition of corn residue with a: “C to N ratio of 40 & (NH4)2SO4 and no addition (control)” (69% and 68%, respectively) < “C to N ratio of 20” (73%) < “C to N ratio of 40” (95%). In all treatments the proportion of the added amino acids that were mineralized increased with time, indicating that the MIT route became more important over time. To investigate the effects of soil depth on the N uptake route of soil microorganisms (experiment II), soil samples in two soil depths (0-5 cm; 30-40 cm) were incubated with corn residues with different C to N ratios and inorganic N for 21 days at 20 °C and 60% (WHC). The addition of corn residue resulted in a marked increase of protease activity in both depths due to the induction from the added substrate. Addition of corn residue with a wide C to N ratio resulted in a significantly greater part of the direct uptake (97% and 94%) than without the addition of residues (85% and 80%) or addition of residue with a small C to N ratio (90% and 84%) or inorganic N (91% and 79% in the surface soil and subsoil, respectively), suggesting that under conditions of sufficient mineralizable N (C to N ratio of 20) or increased concentrations of NH4+, the enzyme system involved in the direct uptake is slightly repressed. Substrate additions resulted in an initially significantly higher increase of the direct uptake in the surface soil than in the subsoil. As a large proportion of the organic N input into soil is in form of proteinaceous material, the deamination of amino acids is a key reaction of the MIT route. Therefore the enzyme amino acid oxidase contribute to the extracellular N mineralization in soil. The objective of experiment III was to adapt a method to determine amino acid oxidase in soil. The detection via synthetic fluorescent Lucifer Yellow derivatives of the amino acid lysine is possible in soil. However, it was not possible to find the substrate concentration at which the reaction rate is independent of substrate concentration and therefore we were not able to develop a valid soil enzyme assay.
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Este proyecto de tutoría se ha dirigido a alumnos y alumnas del centro que cursan Educación Secundaria Obligatoria y carecen de modelos de conducta adulta positiva o que están expuestos a otros factores de riesgo relacionados con comportamientos negativos y bajo rendimiento académico. El objetivo fundamental ha sido desarrollar relaciones exitosas entre los tutores-ayudantes y sus tutorizados, influir positivamente en el desarrollo personal del adolescente. En muchos casos, esto ha requerido la estimulación de la autoestima, desarrollo de valores positivos, perfeccionamiento de las destrezas de resolución de conflictos, incremento de las destrezas sociales o mejora de las relaciones con la familia y los iguales. Entre estos objetivos conseguidos están el fomentar la responsabilidad social y el rendimiento académico, las actitudes y mejora del comportamiento en el instituto. Los tutores han trabajado con los tutorizados y sus familias, sus profesores y primeros tutores para determinar los logros que se deseaban obtener, y los pasos necesarios para alcanzarlos. Se ha mejorado la convivencia en el centro, se han adelantado a las conductas negativas antes de llegar a medidas extremas, reduciendo partes de sanción, comisiones de convivencia y expulsiones.
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Resumen basado en el de la publicación. Elaborado por el grupo de trabajo e investigación 'Educación intercultural, atención educativa al alumnado inmigrante' (Centro de Profesorado de El Ejido)
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Seleccionado en la convocatoria: Ayudas para proyectos de temática educativa, Gobierno de Aragón 2008-09
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Modified (Milkyway) theme for TikiWiki4.2 as used in eHandbook
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En este documento se describe la forma en la que el neuromarketing hace que la segmentación de género, sea una herramienta funcional para poder conocer al cliente y sus deseos. Se explorará el mercadeo desde sus inicios, mostrando cómo evoluciona hasta enfocarse en el cliente como su principal objetivo. Al llegar a este punto el mercadeo se encuentra con un nuevo aliado, la neurociencia, la cual le muestra que por medio de diversas técnicas tiene la capacidad de medir las reacciones de su consumidor, a los distintos estímulos que le envía para cautivarlo. En este proceso se dan a conocer las tecnologías más usadas por el neuromarketing para este fin; además se expondrá parte de la anatomía del consumidor con la que interactúa el mercadeo: sus sentidos y su cerebro. Posteriormente se explica cómo a través del entendimiento de las percepciones y comportamiento del cliente, puede beneficiarse el mercadeo en sus propósitos y su vez, satisfacer al mercado en lo que realmente quiere.
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Lo propuesto en este plan de negocio, es el diseño de un restaurante de comida oriental, recibiendo como nombre de POR TI: COME SALUDABLE, COME RICO, COME POR TI., ubicado en la ciudad de Bogotá D.C, específicamente en el barrio de chico de la localidad de Chapinero, dirigido al 1% de la población flotante y habitantes del sector entre estratos 4 a 6. POR TI nace bajo una propuesta que busca entregar al consumidor salud y cuidado personal. Brindando un producto de excelente calidad, preparado con ingredientes frescos, naturales y basados en recetas caseras, a través del concepto slow food y take away, arraigados en la cocina oriental, buscando crear colores, texturas y sabores que cautiven al consumidor. Se implementaran estrategias claras y concisas que permitan penetrar el mercado de la forma se ajuste a las necesidades del mismo. Se espera y aspira iniciar operaciones para Mayo del 2016, con un incremento de las ventas prometedor superando así el punto de equilibrio para el segundo año.