Institutional Context, Organizational Resources and Strategic Choices: Explaining Interest Group Access in the European Union

Drawing on a survey of 800 business associations, the article seeks to explain why interest groups lobby the EU institutions and what groups maintain contacts with them. Rooted in organizational theory, it argues that four main dimensions influence access patterns — institutional context, resource dependencies, interest group organization, and strategic choices. The empirical analysis demonstrates that all dimensions are relevant. Nonetheless, contacts between EU policy-makers and interest groups display only a few general traits: they are shaped by the political mobilization of groups in response to EU regulation, the division of labour among EU and national associations and the importance of organizational resources. Beyond these general influences, the interactions vary profoundly in the segmented institutional context

Preparation of silver nanoparticles stabilized by dextran and oligosaccharides-based amphiphiles for application in catalysis and sensors

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Química, Florianópolis, 2013.O objetivo principal deste trabalho é a preparação, caracterização e estudos catalítico e de detecção de lectinas por nanopartículas de prata (AgNPs) tendo compostos a base de açúcares como estabilizantes. Para atingir esse objetivo duas estratégias foram utilizadas, uma usando o polissacarídeo dextrana como estabilizante e outra usando compostos anfifílicos baseados em oligossacarídeos (maltose, lactose, maltoheptaose e xiloglucano). Em ambas estratégias, a otimização da preparação das AgNPs foi realizada utilizando-se análise multivariada baseada nas informações coletadas a partir da banda de ressonância de Plasmon de superfície (SPR) das AgNPs. Todas as AgNPs estáveis foram caracterizadas pelas técnicas de UV-Vis, TEM, SAXS e DLS. A atividade catalítica das AgNPs foram determinadas frente a reação de redução do p-nitrofenol (Nip) por NaBH4, como agente redutor, em água e misturas de água/etanol.Dois tipos diferentes de anfifílicos foram sintetizados, um com grupo alquino na junção do bloco de açucar com o bloco hidrofóbico e outro tipo com um grupo ácido carboxílico no final da parte hidrofóbica. Os anfifílicos foram caracterizados por 1H e 13C NMR e espectrometria de massas.A reação de redução do Nip por NaBH4 teve a melhor atividade catalítica com as nanopartículas AgNPs-dextran e Ag-Mal7NAcC12, com constante de velocidade normalizada para a área superfícial das NPs por unidade de volume de 1,41 e 1,11 s-1 m-2 L, repectivamente. Estes valores estão entre os maiores descritos na literatura. O efeito do solvente nesta reação foi avaliado por misturas de água e etanol. Aplicando uma reação superfícial pseudo-monomolecular como um artifício experimental, os dados cinéticos obtidos foram tratados de acordo com o modelo de Langmuir, que combinados com observações de tensão superfícial de misturas de água/etanol, revelaram que a adição de etanol inibe a reação, provavelmente pela competição com os íons BH4- pela superfície da nanopartícula, com a formação de uma monocamada de solvente. Finalmente, três sistemas diferentes (Ag-Mal7NAcC12, Ag-XGONAcC12 e Ag-LacNAcC12) foram testados como sensores para detecção de lectinas e somente Ag-Mal7NAcC12 mostrou interação específica com a Concanavalina A. The main goal of this work is the preparation, characterization and catalytic and lectins detection studies of silver nanoparticles (AgNPs) having sugar-based compounds as stabilizers. To achieve this goal two strategies were used, one using the polysaccharide dextran as stabilizer and other using amphiphile compounds based on oligosaccharides (maltose, lactose, maltoheptaose and xyloglucan). In both strategies the optimization of AgNPs preparation was realized using a multivariate analysis based in informations collected from the surface Plasmon resonance band (SPR) of AgNPs. All stable AgNPs were characterized by ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), small angle X-ray scattering (SAXS) and dynamic light scattering (DLS) techniques. The catalytic activities of AgNPs were determined over the p-nitrophenol reduction reaction by NaBH4, as reducing agent, in water or water-ethanol mixtures. Two different types of amphiphiles were synthesized, one with an alkyne group in the junction of a sugar block with a hydrophobic block and the other with a carboxylic acid group in the end of hydrophobic part. The amphiphiles were characterized by 1H and 13C NMR and mass spectrometry.The Nip reduction reaction with NaBH4 showed the best catalytic activity with AgNPs-dextran and Ag-Mal7NAcC12 nanoparticles with the rate constant normalized to the surface area of the NPs per unit volume of 1.41 and 1.11 s-1 m-2 L, respectively. These values are among the highest ones found in literature. The solvent effect in this reaction was evaluated by mixtures of water and ethanol. Applying a pseudo-monomolecular surface reaction as an experimental artifice, the obtained kinetic data were treated according to the Langmuir model, which combined with water/ethanol surface tension observations revealed that addition of ethanol inhibit the reaction, most probably by competing with BH4- ions for the nanoparticles surface, with the formation of a solvent monolayer.Finally, three different systems (Ag-Mal7NAcC12, Ag-XGONAcC12 and Ag-LacNAcC12) were tested as sensor for lectin detection and Ag-Mal7NAcC12 nanoparticles showed specific interaction with the Concanavalin A

Polynomial matrices and feedback

No abstract

A geometric framework for constraints and data:from linear systems to convex processes

In part one of this thesis we develop the theory of analyis of convex processes. The results of this development can be directly applied to the analysis of discrete time, linear, time-invariant mathematical systems with conic constraints. Such constraints arise from physical properties of natural phenomena, and hence it is important that these are considered in the mathematical models thereof. In part two we focus determining whether a system has a given system theoretic property on the basis of measured data. For this, we develop the informativity framework, which allows us to consider and resolve a large number of such problems

Crystallization phenomena in germanium antimony phase-change films

Phase-changematerialen worden momenteel op grote schaal toegepast in herschrijfbare DVD's en Blu-rays. Hierbij wordt het verschil in optisch contrast tussen de meta-stabiele amorfe fase en stabiele kristallijne fase gebruikt om binair data op te slaan. Naast het optische contrast is er ook een sterk contrast in elektrische weerstand tussen de twee fasen en dit wordt gebruikt om een elektrisch geheugen te maken dat op termijn flashgeheugen kan vervangen. In deze thesis zijn de kristalgroeieigenschappen onderzocht van germanium-antimoonlegeringen, welke typische phase-changematerialen zijn. Met behulp van een optische hogesnelheidscamera hebben we de kristalgroei op een directe manier gevolgd. Door de compositie van de legering met enkele atoomprocenten aan te passen zien we een sterke verandering in groeisnelheden en activeringsenergieën. Door de temperatuur verder te verhogen laten we zien dat het veelal aangenomen Arrheniusverband niet meer geldt op hogere temperaturen. Door externe spanningen aan te brengen in het phase-changemateriaal zijn we in staat om de groei te versnellen of af te remmen. Bovendien is de kristalgroeirichting te sturen door anisotrope spanningen te induceren. De verschillen in elektrische eigenschappen tussen de twee fasen zijn in detail onderzocht. Hierbij is aangetoond dat er aan het grensvlak van kristallijn en amorf een Schottky barrière aanwezig is met een bijbehorend potentiaalverschil. Naast de experimentele studies is kristalnucleatie, in het bijzonder het groei- en vervalgedrag van clusters met een kritieke grootte, bestudeerd met behulp van computersimulaties