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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Self-assembly of Benzenesulfonate Amphiphiles and Synthesis of Membranes Containing Self-assembled Supramolecular Transport Channels

Song, Enfeng 07 January 2014 (has links)
Six series of cunitic amphiphiles based on benzene sulfonates were synthesized. The molecular characterization was performed by IR and NMR spectroscopy and the purity was determined by elemental analysis and thin layer chromatography. The thermotropic properties of these cunitic sulfonate amphiphiles were subsequently investigated by means of a combination of DSC, polarized microscopy and X-ray scattering. Most of the synthesized sulfonates were found to exhibit hexagonal columnar mesophases, some of them exhibited a complex polymorphism. The polymorphism depended upon variation of the molecular structure. The Six series of cunitic amphiphiles based on benzene sulfonates were synthesized. The molecular characterization was performed by IR and NMR spectroscopy and the purity was determined by elemental analysis and thin layer chromatography. The thermotropic properties of these cunitic sulfonate amphiphiles were subsequently investigated by means of a combination of DSC, polarized microscopy and X-ray scattering. Most of the synthesized sulfonates were found to exhibit hexagonal columnar mesophases, some of them exhibited a complex polymorphism. The polymorphism depended upon variation of the molecular structure. The phase behavior was determined by the nature of headgroup cation Mn+ (n=1, 2), and for the same Mn+ by the carbon number at the hydrophobic tail and by temperature as well. The lyotropic properties of these cunitic sulfonate amphiphiles were also studied by investigating their gelation behavior and gelling capability. A number of the amphiphiles were found to be favorable organogelators that gel various organic solvents of either high or low polarity upon self-aggregation driven by the Coulomb interaction. The morphological results by means of SEM and TEM demonstrate that the organogelators are able to form fibrous network microstructures by self-organization and self-aggregation. The cylindrical aggregates with sulfonated headgroup in the center as well embody the potential to construct ion-selective transport membranes. The cunitic amphiphiles containing polar sulfonate units at their focal point and polymerizable olefin group on their periphery were exploited to prepare functional membranes that contain ion-active transport channels. The ion-selectivity of the formed membranes was investigated by means of ion transport experiments with LiCl, NaCl, KCl solutions of different concentration. By comparison of the ion transport rates across the membranes the ionic permselectivity was demonstrated.
22

Nano-assemblages d'ADN induites par des cibles - Détection de petites cibles par formation de réseaux d'ADN / Nano-DNA induced target assemblies - detection of small targets of DNA by forming networks

Lu, Chenze 13 November 2017 (has links)
La détection de petites molécules contribue au développement de nombreux domaines tels que la sécurité alimentaire, la sécurité intérieure, le diagnostic, le contrôle de l'environnement, etc. Cependant, la petite taille de ces cibles et leur faible concentration rendent difficile leur détection. Pour pallier à cela, des biocapteurs avec des sondes appropriées et des stratégies d'amplification du signal sont nécessaires. Parmi les éléments de reconnaissance couramment utilisés, les aptamères présentent l'avantage d'une synthèse aisée et de grandes possibilités de modification, ainsi qu'une dénaturation réversible à haute température et une tolérance élevée à la concentration en sel et au pH dans le milieu de travail. Plus important encore, la petite taille des aptamères en fait un choix idéal pour créer des structures adaptées pour la détection de petites cibles. La possibilité de couper la séquence de l'aptamère a fourni d'autres approches d’amplification de signal. Il existe deux catégories de méthodes de détection basées sur des aptamères : analyse hétérogène lorsque l'aptamère est immobilisé sur la surface ou analyse homogène lorsque le test est réalisé en solution. Nous proposons dans cette thèse une approche appliquable aux deux stratégies. L'adénosine a été utilisée comme une cible modèle pour cette preuve de concept. La détection de l'adénosine a été obtenue en combinant l'auto-assemblage de dimères d'oligonucléotides avec des extrémités pendantes correspondantes à l'aptamère coupé. Nous avons construit des structures auto-assemblées d'ADN (de 1D à 3D) avec l'adénosine comme déclencheur d'un changement structurel. La première méthode décrite dans ce travail consiste à utiliser de telles structures d'ADN combinées à l'imagerie par Résonance de Plasmons de Surface (SPRi). La SPRi est une méthode sensible à la variation d'indice optique produite par l'interaction entre les sondes immobilisées sur le prisme de l'or et la cible dans la solution. En présence d'adénosine, la structure d'ADN s'auto-assemble sur la surface de l'or et un signal a été créé. La limite de détection de l'adénosine atteinte par cette méthode est de 10 μM. La deuxième homogène méthode consiste à analyser les variations d'absorbance UV de la solution contenant les structures d'ADN puisque l'absorbance UV de l'ADN monocaténaire et du duplex ADN hybride est différente. En raison de cet effet, la température de fusion des brins d'ADN peut être déterminée par la dérivée de l'absorbance UV mesurée. Les structures d'ADN combinant les extrémités pendantes de l'aptamère coupé couplés à des oligonucléotides complémentaires présentent deux températures de fusion caractéristique de la dissociation de chaque partie. L'une correspond à l'oligonucléotide hybridé et l'autre à l'aptamère coupé liant l'adénosine. En présence d'adénosine dans la solution, la stabilité de la structure augmente et le pic de fusion de l'aptamère coupé est décalé à une température plus élevée tandis que le second pic de fusion reste identique et peut servir de référence interne. La limite de détection atteinte pour cette méthode est de 1 μM. Les structures d'ADN que nous avons proposées s'auto-assemblent de manière linéaire ou bi- ou tri-dimensionnelle : la structure 1D est une chaîne d'ADN formée par un enchainement de dimères connectés par des extrémités formées de l'aptamère scindé; La structure en 2D est une structure en forme de Y formée par un ADN simple brin avec une extrémité aptamère scindé sur chaque branche du "Y"; La structure 3D est un tétraèdre formé par quatre simple brins d'ADN avec des extrémités aptamère scindé sur les quatre sommets. En présence d'adénosine, les structures 2D et 3D peuvent s'auto-assembler et ainsi former un réseau avec les extrémités pendantes. La structure 1D a été mûrement développée pour les deux méthodes, les structures 2D et 3D ont été prouvées efficaces pour la détection, mais nécessitent encore plus d'efforts pour permettre une détection optimisée. / The detection of small molecules contributes to the development of many fields such as food safety, homeland security, diagnose, environment control, etc. However, their small size and low concentration are the usual cause of limitations in their detection. In order to improve the detection, biosensors with appropriate probes and signal amplification strategies are required. Amongst the commonly used recognition elements, aptamer has the advantage of easier mass production and modification, reversible denaturation at high temperature and high tolerance of salt concentration and pH in the working environment. More importantly its small size made it an ideal choice for creating delicate structures for the detection of small targets. The possibility of splitting the aptamer sequence has provided more approaches for amplification purpose. There are two categories of detecting methods based on aptamers: heterogeneous analyzation where the aptamer is immobilized on a surface or homogeneous analyzation where the assay is performed in solution. In this thesis, we proposed an amplification method useful for both heterogeneous and homogeneous assays. Adenosine was used as a proof of concept target. The detection of Adenosine was achieved by combining the self-assembly of oligonucleotide dimers with split-aptamer dangling ends. We constructed self-assembled DNA structures (from 1D to 3D) with Adenosine as the trigger for a structural change. The heterogeneous assay is based on in Surface Plasmon Resonance imaging (SPRi). SPRi is a method sensitive to the change of refraction index created by the interaction between the probes immobilized on the gold surface and the targets in the flowing solution. With the presence of Adenosine in the solution, the DNA structure is self-assembled on the gold surface and the signal was created. The detection limit achieved by this method was 10 µM. The second homogeneous assay is based on the melting profile of the solution determined from the absorbance of UV light (260 nm wavelength). The UV absorbance of single strand DNA and hybridized DNA duplex is different. Due to this effect, the melting temperature could be obtained from the UV absorbance measured. The DNA structures combining self-complementary oligonucleotides and split-aptamer dangling ends have two melting temperatures, one correspond to the oligonucleotides and the other to the split-aptamer. In presence of Adenosine in the solution the strength in the binding is increased. As a result, the melting peak of the split-aptamer shifted to higher temperature while the second melting peak correspond the oligonucleotide remains the same as an internal reference. The detection limit achieved for this method was 1 µM. The DNA structures we proposed varied from 1D to 3D: the 1D structure was a DNA chain formed by a series of dimers connected through split-aptamer dangling ends; the 2D structure was a Y shape structure formed by three single-strand DNA with a split-aptamer dangling end on each branch of the “Y”; the 3D structure was a tetrahedron formed by four single-strand DNA with split-aptamer dangling ends on the four vertexes. With presence of Adenosine, 2D and 3D structures can further form a network with the dangling ends. The 1D structure has been maturely developed for the two detection methods, the 2D and 3D structures have been proven effective for detection but still require more efforts to reach perfection.
23

An Experimental Implementation of Action-Based Concurrency

Cui, Xiao-Lei 01 1900 (has links)
This thesis reports on an implementation of an action-based model for concurrent programming. Concurrency is expressed by allowing objects to have actions with a guard and a body. Each action has its own execution context, and concurrent execution is realized when program execution is happening in more than one context at a time. Two actions of different objects can run concurrently, and they are synchronized whenever a shared object is accessed simultaneously by both actions. The appeal of this model is that it allows a conceptually simple framework for designing and analyzing concurrent programs. To experiment with action-based concurrency, we present a small language, ABC Pascal, which is an experimental attempt as a proof of feasibility of such a model, and also meant to help identify issues for achieving reasonable efficiency in implementation. It extends a subset of Pascal that supports basic sequential programming constructs, and provides action-based concurrency as the action-based model prescribes. This work deals with the specification and implementation of ABC Pascal. The one-pass compiler directly generates assembly code, without devoting efforts to optimization. While the code is not optimized, the results that ABC Pascal has achieved in performance testing are so far comparable to mainstream concurrent programming languages. / Thesis / Master of Science (MSc)
24

NOVEL STOCHASTIC PROGRAMMING FORMULATIONS FOR ASSEMBLE-TO-ORDER SYSTEMS

LIANG, HONGFENG January 2017 (has links)
We study a periodic review assemble-to-order (ATO) system introduced by Akcay and Xu (2004) which jointly optimizes the base stock levels and the component allocation with an independent base stock policy and a first-come- first-served allocation rule. The formulation is a non-smooth and thus theoretically and computationally challenging. In their computational experiments, Akcay and Xu (2004) modified the right hand side of the inventory availability constraints by substituting linear functions for piece-wise linear ones. This modification may have a significant impact on low budget levels. The optimal solutions obtained via the original formulation, i.e., the formulation without modification, include zero base stock levels for some components and thus indicate a bias against component commonality. We study the impact of component commonality on periodic review ATO systems. We show that lowering component commonality may yield a higher type-II service level. The lower degree of component commonality is achieved via separating inventories of the same component for different products. We substantiate this property via computational and theoretical approaches. We show that for low budget levels the use of separate inventories of the same component for different products can achieve a higher reward than with shared inventories. Finally, considering a simple ATO system with one component shared by two products, we characterize the budget ranges such that either separate or shared inventory component (i.e., component commonality) is beneficial. / Thesis / Doctor of Philosophy (PhD)
25

Stochastic Programming Formulations and Structural Properties for Assemble-to-Order Systems

Wang, Xiao Jiao January 2020 (has links)
Lowering the degree of component commonality may yield a higher type-II service level for a periodic review assemble-to-order system that aims to maximize reward. This is achieved via separating inventories of all the shared components for different products. We investigate the optimal bill-of-materials structure for two-product assemble-to-order systems with arbitrary number of components. The inventory of a shared component can be separated or common between different products. We show that an optimal bill-of-materials can be characterized between the following two extremal configurations: either two products share all common components, or they do not share any common component. / Thesis / Doctor of Philosophy (PhD)
26

Magnetoelectric Oxide Nanocomposite Heterostructures

Li, Yanxi 28 February 2017 (has links)
Multiferroics have attracted lots of research interest due to their potential in numerous multifunctional applications. The multiferroic materials could simultaneously exhibit two or more ferroic order parameters, and the coupling effects between ferroelectricity and ferromagnetism are named as magnetoelectric (ME) effect. Recently, with the development of thin film growth techniques, the multiferroics magnetoelectric composite heterostructures exhibit a very promising future prospects. This dissertation focused on the design, fabrication and characterization of new multiferroics magnetoelectric composite heterostructures. First, based on the specific phase architectures in BFO-CFO self-assembled thin films grown on variously oriented STO substrates and the epitaxial film growth knowledge, I designed two kinds of new film heterostructures: (i) I utilized self-assembled BFO nanopillars in a BFO-CFO two phase layer on (111) STO as a seed layer on which to deposit a secondary top BiFeO3 layer. The growth mechanism and multiferroic properties of these new heterostructures were investigated. (ii) I demonstrated the formation of a new quasi-(0-3) heterostructure by alternately growing (2-2) and (1-3) layers within the film. I proposed a new concept to overcome limitations of both the (2-2) and (1-3) phase connectivities and identified an indirect ME effect by the switching the characteristics of the piezoresponse for the new heterostructure. Second, for the option for candidates thin film materials with a high piezoelectric coefficient, which is a critical factor for ME composite films, I utilized the simple compositional BaSn0.11Ti0.89O3 bulk ceramic material as a target to grow films with the large piezoelectric properties. The grown high qualify lead-free epitaxial thin films had a chemical constituent similar to the reported giant piezoelectric ceramics near the MPB and with the QP. Both coherent and incoherent regions were observed in the interface and a larger piezoelectric coefficient d33 was achieved in this film. Finally, with respect to their characteristics and potential, I redirected from two-dimensional thin film materials to one-dimensional nanowire materials. By utilizing vertically aligned templates, I fabricated a new type of coaxial two-phase composite nanowires. Multiferroic properties of these new one-dimensional materials have been investigated. All these multiferroics magnetoelectric composite herterostructures would provide lots of potential in applications. / PHD
27

Analyse et algorithmes de résolution de systèmes ATO (Assemble-To-Order) : Applications aux systèmes du type W / Analysis and Computational Algorithms for Assemble-To-Order systems : Application to W-configuration systems

Fang, Jianxin 02 October 2017 (has links)
Nous analysons un type W de système de l’Assemble-à-commande avec des délais de livraison aléatoires, l'arrivée aléatoire de la demande et des ventes perdues, en temps continu. Nous formulons le problème en tant que processus de décision Markov à l'horizon infini. Nous nous éloignons de l'approche standard en caractérisant une région de l'espace d'état où toutes les propriétés de la fonction de coût tiennent. Nous caractérisons la politique optimale dans cette région. En particulier, nous montrons que, dans l'intérieur de la région récurrente, les composants sont toujours produits. Nous caractérisons également la politique d'allocation de composants optimale qui spécifie si une demande de produit arrivant devrait être remplie. Notre analyse révèle que la politique d'allocation optimale est contre-intuitive. Par exemple, même lorsqu'un produit domine l'autre, en termes de coût/taux de vente perdue, sa demande peut ne pas avoir une priorité absolue par rapport à la demande de l'autre produit. Une telle caractéristique n'a pas été observée dans de nombreux paramètres intégrés de production/inventaire où l'allocation d'inventaire suit une priorité fixe pour satisfaire les exigences. Nous montrons également que la structure de la politique optimale reste la même pour les systèmes à production par lots, les temps de production répartis par Erlang et la demande de produits non unitaire. Enfin, nous proposons des heuristiques efficaces qui peuvent être utilisées comme substitut à la politique optimale ou peuvent être utilisées comme une politique de départ pour les algorithmes communs utilisés pour obtenir une politique optimale dans le but de réduire leur temps de calcul. / We analyze a W-configuration assemble-to-order system with random lead times, random arrival of demand, and lost sales, in continuous time. We formulate the problem as an infinite-horizon Markov decision process. We deviate from the standard approach by first characterizing a region (the recurrent region) of the state space where all properties of the cost function hold. We then characterize the optimal policy within this region. In particular, we show that within the interior of the recurrent region components are always produced. We also characterize the optimal component allocation policy which specifies whether an arriving product demand should be fulfilled. Our analysis reveals that the optimal allocation policy is counter-intuitive. For instance, even when one product dominates the other, in terms of lost sale cost and lost sale cost rate (i.e., demand rate times the lost sale cost), its demand may not have absolute priority over the other product’s demand. Such a feature has not been observed in many integrated production/inventory settings where inventory allocation follows a fixed priority in satisfying demands. We also show that the structure of the optimal policy remains the same for systems with batch production, Erlang distributed production times, and non-unitary product demand. Finally, we propose efficient heuristics that can be either used as a substitute for the optimal policy or can be used as a starting policy for the common algorithms that are used to obtain the optimal policy in an effort to reduce their computational time
28

Commande optimale (en Production et Stock) de Systèmes Assemble-To-Order (ATO) avec prise en compte de demandes en composants individuels / Integrated Production and Inventory Control of Assemble-To-Order Systems with Individual Components Demand

Li, Zhi 03 September 2013 (has links)
Les systèmes assemble-to-order (ATO) peuvent être considérés comme une affectation de ressources multiples qui induit planification de production, satisfaction des contraintes et affectation des stocks. Les systèmes ATO représentent une stratégie de logistique populaire utilisée en gestion de fabrication. En raison de la complexité croissante des systèmes de fabrication d'aujourd'hui, le défi pour les systèmes ATO est de gérer efficacement les stocks de composants et de trouver les décisions optimales de production et d'affectation.Nous étudions un système ATO avec un produit unique qui est assemblé à partir de plusieurs composants. Le système doit répondre à une demande non seulement du produit assemblé, mais aussi des composants individuels. Nous considérons le cas avec seulement des lost sales puis le cas mixte lost sales et backorders avec des temps de production suivant des lois de type exponentiel et une demande sous forme de loi de Poisson. Nous formulons le problème comme un Processus de décision markovien (MDP), et nous considérons deux critères d'optimalité qui sont le coût actualisé et le coût moyen par période. Nous caractérisons la structure de la politique optimale et étudions l'impact des différents paramètres du système sur cette politique. Nous présentons également plusieurs heuristiques pour le cas lost sales et le cas mixte lost sales et backorders. Ces heuristiques fournissent des méthodes simples, mais efficaces pour contrôler la production et l’affectation des stocks du système ATO / Assemble-to-order (ATO) systems can be regarded as a multiple resource allocation that induces production planning, requirements fulfilling and inventory assignment. ATO is a popular strategy used in manufacturing management. Due to the increasing complexity of today’s manufacturing systems, the challenge for ATO systems is to efficiently manage component inventories and make optimal production and allocation decisions. We study an ATO system with a single product which is assembled from multiple components. The system faces demand not only from the assembled product but also from the individual components. We consider the pure lost sales case and the mixed lost sales and backorders case with exponential production times and Poisson demand. We formulate the problem as a Markov decision process (MDP), and consider it under two optimality criteria: discounted cost and average cost per period. We characterize the structure of the optimal policy and investigate the impact of different system parameters on the optimal policy. We also present several static heuristic policies for the pure lost sales and the mixed lost sales and backorders cases. These static heuristics provide simple, yet effective approaches for controlling production and inventory allocation of ATO system
29

Saldoavvikelser i producerande företag : En fallstudie på Getinge Disinfection AB

Andersson, Jim, Bergman, Jakob January 2020 (has links)
Sammanfattning Kurs: Examensarbete i Logistik för Civilekonomprogrammet, 30 hp, 4FE19E.  Författare: Jakob Bergman och Jim Andersson. Examinator: Peter Berling Handledare: Peter Berling  Medbedömare: Hana Hulthén Titel: Saldoavvikelser i producerande företag, en fallstudie på Getinge Disinfection AB. Bakgrund: En välfungerande lagerhållning är en väsentlig grundsten för ett företags framgångar. I takt med att lagerhållningen blivit mer automatiserad och effektiviserad ställs högre krav på att informationen om lagersaldon stämmer överens med verkligheten. Saldoavvikelser är ett utbrett problem som kan påverka många olika delar av en verksamhet, såsom felaktiga underlag för inköp, den dagliga driften och företagets servicegrad. Fallföretaget Getinge Disinfection AB upplever främst att saldoavvikelser på företaget får effekt på den dagliga driften, något som denna studie ämnar undersöka. Syfte: Studien syftar till att identifiera konsekvenser och orsaker till saldoavvikelser på Getinge Disinfection AB samt ge förbättringsförslag som kan reducera saldoavvikelser på företaget. Metod: Denna studie har en kvalitativ forskningsstrategi. Vidare är studiens forskningsdesign en fallstudie då den endast undersöker ett fall ingående och detaljerat. Resultat: Studien fann att saldoavvikelser kan uppstå i alla steg i den studerade processen, med varierande primära orsaker i de olika stegen i processen. Bland de konsekvenser som funnits är de främsta icke-värdeskapande aktiviteter, opålitliga underlag för inköpsbeslut, OOS och ökade ledtider. Majoriteten av orsakerna grundar sig i den mänskliga faktorn, det vill säga att anställda inte följer rutiner eller gör misstag i processen. Dessa misstag kan ske i olika aktiviteter i processen och det finns olika primärorsaker beroende på var i processen misstaget sker. Vidare har författarna tagit fram förbättringsförslag för att effektivisera Getinge Disinfection ABs produktionsprocess. De mest lämpliga förbättringsförslagen är att skapa förståelse om saldoavvikelser bland de anställda, införa Cycle counting, digitalisera olika aktiviteter och utvärdera det nuvarande artikelsortimentet. Nyckelord: Saldosäkerhet, Saldoavvikelser, Producerande företag, Medicinteknik, Life Science, Assemble to Order, ATO, Cycle Counting, RFID, Streckkoder. / Abstract  Course: Degree project in Logistics, the Business Administration and Economics Programme, 30 credits, 4FE19E.    Authors: Jakob Bergman and Jim Andersson. Examiner: Peter Berling.  Tutor: Peter Berling. Co-judger: Hana Hulthén Title: Inventory record inaccuracies in manufacturing companies, a case study on Getinge Disinfection AB. Background: Effective inventory management is of considerable importance for most successful businesses. Without it, companies would be hard-pressed to meet the demands of consumers that place a high value on fast deliveries and product availability. As a result, businesses have turned to increased automation of their inventory management. This automation relies heavily on information such as inventory records being accurate and up to date. Inventory record inaccuracies result in purchases or decisions being made on incorrect assumptions of the companies’ actual inventory status, which has a negative effect on many aspects of the business. However, most studies on this subject focus on inventory record inaccuracies in a retailing context, whereas this study focuses on a large manufacturing company (Getinge Disinfection AB) using an Assemble to Order model. Purpose: The purpose of this study is to identify the different causes and consequences of inventory record inaccuracies (IRI) at Getinge Disinfection AB. Furthermore, the study aims to offer proposals on how to improve inventory record accuracy at Getinge Disinfection AB.    Methodology: This paper adopts a qualitative research strategy with a case-study approach.  Findings: The study concluded that inventory record inaccuracies can arise in all areas of the studied process, with different primary reasons for different stages of the process. Most of the causes of IRI can be attributed to the human factor, such as incorrect identification of the items, unregistered movements of goods, and transaction errors. The consequences of (IRI) were mainly the resulting non-value adding activities, purchasing decisions being made based on unreliable inventory data, stockouts and longer lead times. The study also gives suggestions on how Getinge could reduce these inventory record inaccuracies. Improvement measures such as Cycle counting, bar coding of the items and locations and increased staff training are discussed. Keywords: Inventory Record Accuracy, Inventory Record Inaccuracy, Manufacturing, Health Care, Life Science, Assemble to Order, ATO, Cycle Counting, RFID, Bar coding.
30

Nanoestruturas metálicas e de silício para intensificação de campo próximo. / Metal and silicon nanostructures to near-field intensification.

Raimundo, Daniel Scodeler 08 October 2009 (has links)
Durante os últimos cinco anos, a nanotecnologia tem atingido avanços significativos em diversas áreas da ciência e tecnologia. Um dos assuntos que está sendo intensamente estudado pela comunidade científica é a intensificação de campo próximo (hot spot) que pode ser aplicada em dispositivos sensores com capacidade de detecção de apenas uma molécula e em nano-antenas ópticas aplicadas na fabricação de dispositivos plasmônicos. Neste sentido, as principais contribuições da presente tese são processos de fabricação de nanoestruturas metálicas e de silício e o estudo da intensificação de campo próximo denominada de pontos quentes (hot spots) nestas estruturas. As nanoestruturas metálicas de Au (ouro) foram obtidas a partir do processo de auto-organização de esferas de poliestireno. As esferas de poliestireno serviram como camada sacrificial (molde) para a obtenção de nanoestruturas metálicas organizadas. Sobre as estruturas de Au organizadas foram depositadas moléculas de cristal violeta para serem utilizadas como moléculas de prova (sondas) no monitoramento da existência dos pontos quentes com o auxílio do espalhamento Raman das moléculas. As nanoestruturas de Au possibilitaram uma intensificação do espalhamento Raman devido à intensificação do campo próximo na superfície metálica periódica de Au. As nanoestruturas e microestruturas de silício foram obtidas a partir da tecnologia de silício poroso. As propriedades do silício poroso foram moduladas através da implantação de íons de hidrogênio (H +) que possibilitou a formação de silício microporoso com forte emissão fotoluminescente (PL) e intensificação do espalhamento Raman superficial devido ao fenômeno de Raman ressonante. Sobre as estruturas macroporosas de silício foram adsorvidas moléculas de azul de metileno para serem utilizadas como moléculas de prova para monitoramento da intensificação do campo próximo e do efeito SERS no silício. A obtenção da intensificação de campo próximo em silício é uma contribuição completamente inédita, pois este fenômeno devia-se, até o momento, somente a materiais metálicos (nanoestruturas metálicas), mostrando sua existência também no silício. / During the last five years, nanotechnology has achieved significant progress in several areas of science and technology. One of the issues that are being intensively studied by the scientific community is the intensification of near-field (hot spot) that can be applied to devices with sensors capable of detecting a single molecule and nano-optical antennas used in the fabrication of plasmonic devices. In this sense, the main contributions of this thesis are processes for manufacture of metal and silicon nanostructures and the study of near-field intensification called hot spots in these structures. The metal nanostructures of Au (gold) were obtained from the process of self-assembling of polystyrene beads. The polystyrene beads were used as sacrificial layer (mold) for obtaining organized metallic nanostructures. On the structures of organized Au were deposited molecules of violet crystal to be used as proof of molecules (probes) to monitor the existence of hot spots with the help of Raman scattering of molecules. The Au nanostructures allowed an intensification of the Raman scattering due to the intensification of the near-field in the periodic Au surface. The microstructures and nanostructures of silicon were obtained using the porous silicon technology. The properties of porous silicon were modulated by the implantation of hydrogen ions (H +) that allowed the formation of microporous silicon which showed high photoluminescence emission (PL) and Raman scattering intensification of the surface due to the phenomenon of resonant Raman. Methylene blue molecules were adsorbed on the macroporous silicon structures to be used as probe molecule for the monitoring of near-field intensification and the SERS effect in silicon. The obtaining of near-field intensification in silicon is an entirely unprecedented contribution, because this phenomenon had been observed, so far, only on the metallic materials (metal nanostructures), showing its existence in the silicon too.

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