881 resultados para LNT CATALYST
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Dissertação de mestrado integrado em Arquitectura
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Nanocomposite materials with an organic-inorganic urea-silicate (di-ureasil) based matrix containing gold nanoparticles (NPs) were synthesized and characterized by optical (UV/Vis) spectroscopy and indentation measurement. The urea silicate gels were obtained by reaction between silicon alkoxyde modified by isocyanate group and polyethylene glycol oligomer with amine terminal groups in presence of catalyst. The latter ensures the successful incorporation of citrate-stabilized gold NPs in the matrix. It is shown that using a convenient destabilizing agent (AgNO3) and governing the preparative conditions, the aggregation degree of gold NPs can be controlled. The developed synthesis procedure significantly simplifies the preparative procedure of gold/urea silicate nanocomposites, compared to the procedure using gold NPs, preliminary covered with silica shells. Mechanical properties of the prepared sample were characterised using depth sensing indentation methods (DSI) and an idea about the type of aggregation structures was suggested.
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Enzymatic polymerization of aniline was first performed in lignosulfonate (LGS) template system. High-redox-potential catalyst laccase, isolated from Aspergillus, was used as a biocatalyst in the synthesis of conducting polyaniline/lignosulfonate (PANI-ES-LGS) complex using atmospheric oxygen as the oxidizing agent. The linear templates (LGS), also serving as the dopants, could facilitate the directional alignment of the monomer and improve the solubility of the conducting polymer. The process of the polymerization was monitored using UV-Vis spectroscopy, by which the conditions for laccase-catalyzed synthesis of PANI-ES-LGS complex were also optimized. The structure characterizations and solubility of the complex were carried out using corresponding characterization techniques respectively. The PANI-ES-LGS suspensions obtained was used as coating for cotton with a conventional padder to explore the applications of the complex. The variable optoelectronic properties of the coated cotton were confirmed by cyclic voltammetry and color strength test. The molecular weight changes of LGS treated by laccase were also studied to discuss the mechanism of laccase catalyzed aniline polymerization in LGS template system.
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This work describes the synthesis and characterisation of Ni(II) complexes of the following neutral bidentate nitrogen ligands containing pyrazole (pz), pyrimidine (pm) and pyridine (py) aromatic rings: 2-pyrazol-1-yl-pyrimidine (pzpm), 2-(4-methyl-pyrazol-1-yl)-pyrimidine (4-Mepzpm), 2-(4-bromo-pyrazol-1-yl)-pyrimidine (4-Brpzpm), 2-(3,5-dimethyl-pyrazol-1-yl)-pyrimidine (pz*pm), 2-pyrazol-1-yl-pyridine (pzpy) and bis(3,5-dimethylpyrazol-1-yl)phenylmethane (bpz*mph). The complexes [NiBr2(pzpm)] (1), [NiBr2(4-Mepzpm)] (2), [NiBr2(4-Brpzpm)] (3), [NiBr2(pz*pm)] (4), [NiBr2(pzpy)] (5) and [NiBr2(bpz*mph)] (6) were tested as catalysts for ethylene polymerisation, in the presence of the cocatalysts methylaluminoxane (MAO) or diethylaluminium chloride (AlEt2Cl), the catalyst systems 1-3/MAO showing moderate to high activities up to the temperature of 20 °C only in the presence of MAO, whereas 4-6/MAO revealed to be inactive. Other related Pd(II) complexes, already reported in previous works, such as [PdClMe(pzpm)], [PdClMe(pz*pm)], [PdClMe(pzpy)] and [PdClMe(bpz*mph)], also showed to be inactive in the polymerisation of ethylene, when activated by MAO or AlEt2Cl. Selected samples of polyethylene products were characterised by GPC/SEC, 1H and 13C NMR and DSC, showing to be low molecular weight polymers with Mn values ranging from ca. 550 to 1500 g mol−1 and unusually low dispersities of 1.2–1.7, with total branching degrees generally varying between 2 and 12%, melting temperatures from 40 to 120 °C and crystallinities from 40 to 70%.
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Dissertação de mestrado em Ciências da Educação (área de especialização em Tecnologia Educativa)
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Dissertação de mestrado em Ciências da Educação (área de especialização em Desenvolvimento Curricular e Inovação Educativa)
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Dissertação de mestrado em Sociologia (área de especialização em Desenvolvimento e Políticas Sociais)
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Dissertação de mestrado em Química Medicinal
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Dissertação de mestrado em Química Medicinal
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Reactive Chromatography, Fixed-Bed Reactor, Heterogeneous, Hydrolysis, Ester, Catalyst, Adsorption, Ion-Exchange Resin
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Since the specific heat transfer coefficient (UA) and the volumetric mass transfer coefficient (kLa) play an important role for the design of biotechnological processes, different techniques were developed in the past for the determination of these parameters. However, these approaches often use imprecise dynamic methods for the description of stationary processes and are limited towards scale and geometry of the bioreactor. Therefore, the aim of this thesis was to develop a new method, which overcomes these restrictions. This new approach is based on a permanent production of heat and oxygen by the constant decomposition of hydrogen peroxide in continuous mode. Since the degradation of H2O2 at standard conditions only takes place by the support of a catalyst, different candidates were investigated for their potential (regarding safety issues and reaction kinetic). Manganese-(IV)-oxide was found to be suitable. To compensate the inactivation of MnO2, a continuous process with repeated feeds of fresh MnO2 was established. Subsequently, a scale-up was successfully carried out from 100 mL to a 5 litre glass bioreactor (UniVessel®)To show the applicability of this new method for the characterisation of bioreactors, it was compared with common approaches. With the newly established technique as well as with a conventional procedure, which is based on an electrical heat source, specific heat transfer coefficients were measured in the range of 17.1 – 24.8 W/K for power inputs of about 50 – 70 W/L. However, a first proof of concept regarding the mass transfer showed no constant kLa for different dilution rates up to 0.04 h-1.Based on this, consecutive studies concerning the mass transfer should be made with higher volume flows, due to more even inflow rates. In addition, further experiments are advisable, to analyse the heat transfer in single-use bioreactors and in larger common systems.
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Myocardial ischemic postconditioning (PosC) describes an acquired resistance to lethal ischemia-reperfusion (I/R) injury afforded by brief episodes of I/R applied immediately after the ischemic insult. Cardioprotection is conveyed by parallel signaling pathways converging to prevent mitochondria permeability transition. Recent observations indicated that PostC is associated with free radicals generation, including nitric oxide (NO(.)) and superoxide (O2 (.-)), and that cardioprotection is abrogated by antioxidants. Since NO. And O2 (. -) react to form peroxynitrite, we hypothesized that postC might trigger the formation of peroxyntrite to promote cardioprotection in vivo. Rats were exposed to 45 min of myocardial ischemia followed by 3h reperfusion. PostC (3 cycles of 30 seconds ischemia/30 seconds reperfusion) was applied at the end of index ischemia. In a subgroup of rats, the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis(4-sulphonatophenyl) porphyrinato iron (FeTPPS) was given intravenously (10 mg/kg(-1)) 5 minutes before PostC. Myocardial nitrotyrosine was determined as an index of peroxynitrite formation. Infarct size (colorimetric technique and plasma creatine kinase-CK-levels) and left ventricle (LV) function (micro-tip pressure transducer), were determined. A significant generation of 3-nitrotyrosine was detected just after the PostC manoeuvre. PostC resulted in a marked reduction of infarct size, CK release and LV systolic dysfunction. Treatment with FeTPPS before PostC abrogated the beneficial effects of PostC on myocardial infarct size and LV function. Thus, peroxynitrite formed in the myocardium during PostC induces cardioprotective mechanisms improving both structural and functional integrity of the left ventricle exposed to ischemia and reperfusion in vivo.
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Les piles de combustible permeten la transformació eficient de l’energia química de certs combustibles a energia elèctrica a través d’un procés electroquímic. De les diferents tecnologies de piles de combustible, les piles de combustible de tipus PEM són les més competitives i tenen una gran varietat d’aplicacions. No obstant, han de ser alimentades únicament per hidrogen. Per altra banda, l’etanol, un combustible interessant en el marc dels combustibles renovables, és una possible font d’hidrogen. Aquest treball estudia la reformació d’etanol per a l’obtenció d’hidrogen per a alimentar piles de combustible PEM. Només existeixen algunes publicacions que tractin l’obtenció d’hidrogen a partir d’etanol, i aquestes no inclouen l’estudi dinàmic del sistema. Els objectius del treball són el modelat i l’estudi dinàmic de reformadors d’etanol de baixa temperatura. Concretament, proposa un model dinàmic d’un reformador catalític d’etanol amb vapor basat en un catalitzador de cobalt. Aquesta reformació permet obtenir valors alts d’eficiència i valors òptims de monòxid de carboni que evitaran l’enverinament d’una la pila de combustible de tipus PEM. El model, no lineal, es basa en la cinètica obtinguda de diferents assaigs de laboratori. El reformador modelat opera en tres etapes: deshidrogenació d’etanol a acetaldehid i hidrogen, reformat amb vapor d’acetaldehid, i la reacció WGS (Water Gas Shift). El treball també estudia la sensibilitat i controlabilitat del sistema, caracteritzant així el sistema que caldrà controlar. L’anàlisi de controlabilitat es realitza sobre la resposta de dinàmica ràpida obtinguda del balanç de massa del reformador. El model no lineal és linealitzat amb la finalitat d’aplicar eines d’anàlisi com RGA, CN i MRI. El treball ofereix la informació necessària per a avaluar la possible implementació en un laboratori de piles de combustibles PEM alimentades per hidrogen provinent d’un reformador d’etanol.
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IPH contributed to the Strategic Review of Health Inequalities in England being carried out by Professor Sir Michael Marmot, Chair of the Commission on the Social Determinants of Health. IPH acknowledges the immense work done by the Review team and welcomes the opportunity to inform its work. We see the review as a vital opportunity to provide a “catalyst for concerted action” not only in England but in its near neighbours in Northern Ireland and Ireland. Health inequalities are rife across the UK and Ireland despite a range of developments in policy and practice designed to create more equal opportunities for health. We commend the approach taken in the Review, which applies scientific rigour and the combined expertise of a number of defined task groups to seek solutions to the vexing challenge of health inequality.
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Sixth Annual Report of the Independent Monitoring Group for A Vision for Change – the Report of the Expert Group on Mental Health Policy – July 2012 This is the 6th Annual Report of the Independent Monitoring Group for A Vision for Change (IMG) and the final report of the Second Group. It is clear to the IMG that the implementation of A Vision for Change (AVFC) to date including 2011 has been slow and inconsistent. There is a continued absence of a National Mental Health Service Directorate with authority and control of resources. Such a body has the potential to give strong corporate leadership and act as a catalyst for change. Click here to download HSE National and Regional Progress ReportsHSE – 6th Annual Report HSE – National and Regional Progress Report Progress Reports from Government DepartmentsDepartment of Children and Youth AffairsDepartment of Education and SkillsDepartment of Health Department of Justice and Equality Department of Social ProtectionDepartment of Environment, Community & Local Government National Mental Health Programme Plan Consultation Document What We Heard Submissions Received by the IMGAmnesty International Ireland submission Association of Occupational Therapists submission College of Psychiatry of Ireland submissionCollege of Psychiatry of Ireland – Press Release regarding Social Psychiatry and Recovery Conference College of Psychiatry of Ireland – regarding Psychotherapy Training for Psychiatric TraineesCollege of Psychiatry of Ireland – regarding relationship with Pharmaceutical Industry College of Psychiatry of Ireland – Mental Health in Primary CareDisability Federation of IrelandHealth Research Board submission Irish Association of Social Workers – Adult Mental Health Irish Association of Social Workers – Child and Adolescent Mental Health Irish College of General PractitionersMental Health CommissionMental Health ReformPharmaceutical Society of IrelandIrish Advocacy Network Childrens Mental Health CoalitionNational Disability AuthorityNational Service Users ExecutiveNational Service Users Executive – Second Opinions ReportNational Federation of Voluntary BodiesHeadstrong Â