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Fine Structure of the Dorsal Surface of Ostrich`s (Struthio camelus) Tongue

GUIMARAES, Juliana Placido; MARI, Renata de Britto; CARVALHO, Haley Silva de; WATANABE, Ii-sei
Fonte: ZOOLOGICAL SOC JAPAN Publicador: ZOOLOGICAL SOC JAPAN
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.08%
The tongue of birds fills the oral cavity and has a beak-like shape. Morphological studies of birds reveal a correlation between the structure of the tongue and the mechanism of food intake and the type of food. However, several studies have shown morphological differences among the tongues of bird species. The aim of this study was to analyze ostrich tongue morphology and ultrastructural features using scanning electron microscopy. Tongues from 12 adult ostriches were examined. Six tongues were sectioned sagittally into lateral and middle portions, fixed in 10% formaldehyde solution, and examined under light microscopy. The other six samples were sectioned longitudinally, and the dorsal and ventral surfaces were separated, Immersion-fixed In modified Karnovsky solution, and examined under scanning electron microscopy. The tongue surface of the ostrich was smooth, without lingual papillae, and covered by stratified non-keratinized epithelium. In the submucosal layer, mucous salivary glands were surrounded by connective-tissue capsules, with septa dividing the glands Into lobes. Numerous salivary gland ducts of different sizes and connective-tissue laminae dividing each opening could be clearly seen in scanning electron microscope Images. The ventral surface had fewer openings than the dorsal surface. In samples treated with NaOH...

Estudo da mucosa da língua e da superficie de interface epitélio-tecido conjuntivo da preguiça-de-coleira (Bradypus torquatus, Iliger, 1811), empregando os métodos de microscopia de luz e eletrônica de varredura; Study of the lingual mucosa and surface of interface epithelium-connective tissue of the maned sloth (Bradypus torquatus, Iliger, 1811), employing light and scanning electron microscopy methods

Benetti, Edson José
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 21/12/2005 PT
Relevância na Pesquisa
36.21%
Estudo das superfícies dorsal e ventral da língua e da superfície de interface epitélio-tecido conjuntivo de Bradypus torquatus, foi realizado empregando-se os métodos de microscopia de luz e microscopia eletrônica de varredura. As línguas de Bradypus torquatus foram removidas, dissecadas e seccionadas em 3 partes: rostral, média e caudal e tratadas pelos métodos de microscopia de luz e eletrônica de varredura. Os resultados revelaram que a língua apresenta um ápice arredondado, um corpo e uma raiz. A mucosa dorsal mostra três tipos de papilas linguais: filiformes, fungiformes e vaIadas e uma superfície inferior lisa. Histologicamente, observou-se que a superfície dorsal da língua contém as papilas filiformes, fungiformes e vaIadas, distribuídas nas regiões rostral, média e caudal. A camada epitelial é de espessura variável e possui os estratos basal, espinhosa, granular e córnea, mostrando as células epiteliais. A lâmina própria é caracterizada por um tecido conjuntivo denso formando as projeções papilares longas, curtas e arredondadas. As imagens tridimensionais obtidas pela microscopia eletrônica de varredura, mostraram numerosas papilas filiformes localizadas essencialmente nas regiões rostral e média. Poucas papilas fungiformes estão presentes na superfície dorsal da língua...

Avaliação da eficácia de clareamento, permeabilidade e morfologia superficial do esmalte submetido a diferentes técnicas de aplicação do peróxido de hidrogênio a 35%, após aplicação de flúor; Evaluation of the effectiveness of whitening, morphlogy and perneability of enamel surface under different techniques for application of a hydrogen peroxide 35% after application of fluoride

Schiavoni, Renato Jonas dos Santos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 31/03/2010 PT
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36.13%
Alterações visuais, histoquímicas e micromorfológicas podem ser observadas em superfícies dentais submetidas ao clareamento, desencadeando sensibilidade, menor resistência ao desgaste, maior manchamento e aderência bacteriana. Uma forma de verificar a ocorrência de danos superficiais e sub-superficiais é através da permeabilidade e da avaliação superficial por meio de microscopia eletrônica de varredura. Assim, este estudo in vitro teve por objetivo avaliar a eficácia de clareamento em dentes manchados, a permeabilidade e a morfologia superficial do esmalte dental após tratamento com diferentes técnicas de aplicação do peróxido de hidrogênio a 35% (FGM) seguido ou não da aplicação de flúor. Foram utilizados 260 incisivos bovinos, com superfícies de esmalte de 10x10 mm de área. Após, os espécimes foram casualmente distribuídos (n = 10) e submetidos ao manchamento com café, chá preto e vinho tinto por 72 horas. As medidas de cor eram realizadas com espectrofotômetro de reflexão nos tempos inicial, após o manchamento e logo após a fase de clareamento. Após o período de manchamento os fragmentos eram clareados com peróxido de hidrogênio a 35% (FGM) - convencional, ativado com LED ou laser de Er:YAG seguido ou não da aplicação de flúor (Desensibilize KF 2%...

Análise morfológica e da resistência adesiva dos tecidos dentais duros irradiados com lasers de pulsos ultracurtos; Evaluation of dental hard tissues irradiated with ultra-short pulsed lasers. Influence on surface morphology and microtensile bond strength

Silva, Marina Stella Bello
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/09/2010 PT
Relevância na Pesquisa
46.04%
O desenvolvimento da Odontologia Restauradora culminou com a era das restaurações estéticas adesivas e da intervenção minimamente invasiva, para as quais técnicas inovadoras e materiais de última geração vêm sendo constantemente introduzidos. As técnicas conservadoras visam não somente a remoção do substrato dental cariado, mas também o preparo das paredes da cavidade para a realização da restauração adesiva. Este estudo visou avaliar a possibilidade de introdução dos lasers de pulsos ultracurtos na Odontologia Restauradora, com o intuito de suprir os requisitos básicos para a realização de uma restauração conservadora adequada. A intenção foi de manter os benefícios já conhecidos relacionados à remoção seletiva de cárie com os lasers de alta potência, bem como superar as desvantagens relacionadas às fontes lasers atualmente disponíveis para este fim, como aumento excessivo de temperatura e adesão prejudicada da superfície irradiada à resina composta. Para a melhor avaliação da interação entre os lasers de pulsos ultracurtos e o substrato dental, os experimentos foram realizados em três fases. A Fase 1 visou avaliar o efeito de diferentes comprimentos de onda (355 nm, 532 nm, 1045 nm e 1064 nm)...

Avaliação in vitro da rugosidade superficial de resinas compostas, comparando diferentes sistemas de acabamento e polimento e após a profilaxia com jato de bicarbonato; In vitro evaluation of surface roughness of different composite resins, comparing different finishing and polishing systems and after prophylaxis with bicarbonate jet

Alves, Carol Brandt
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/10/2012 PT
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36.06%
A presente pesquisa in vitro teve como objetivo avaliar a ocorrência de alterações superficiais em três resinas compostas disponíveis comercialmente quando submetidas a tratamentos de polimento e jato de bicarbonato. As alterações foram quantificadas através de análises rugosimétricas e qualificadas através de microscopia eletrônica de varredura. Foram testadas três resinas compostas:nanoparticulada Z350 (3M ESPE, Saint Paul- MN, EUA), microhíbrida Z250 (3M ESPE, Saint Paul- MN, EUA) emicroparticulada Durafill (Heraeus Kulzer, Germany). Para cada resina foram confeccionados quinze corpos de prova com o auxílio de uma matriz aço inox com 7mm de diâmetro e 3 mm de espessura em dois incrementos e fotoativadas seguindo as orientações do fabricante. Os corpos de prova foram mantidos em água destilada a 37°C por 24 horas. Em seguida foram sub divididos em três grupos de acordo com protocolos de acabamento e polimento sendo avaliados o polimento com pontas Enhance® + PoGo (Dentsply, Konstanz, Germany), pontas Astropol (Ivoclar Vivadent, Schaan, Lienchtenstein) e discos Sof Lex Pop On (3M ESPE, Saint Paul- MN, EUA). Todos os espécimes foram submetidos à ciclagem térmica de 5 a 55 °C com tempo de imersão 1 minuto por 1000 ciclos. Após a ciclagem os espécimes foram submetidos a jato de bicarbonato (equipamento Ortusonic Ortus...

Sharpening of periodontal instruments with different sharpening stones and its influence upon root debridement--scanning electronic microscopy assessment.

Silva, Marcelo Vieira; Gomes, Débora Aline Silva; Leite, Fábio Renato Manzolli; Sampaio, José Eduardo Cezar; de Toledo, Benedicto Egbert Correia; Mendes, Ary José Dias
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 17-22
ENG
Relevância na Pesquisa
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The objective of this study was to evaluate, through scanning electronic microscopy, the effect of sharpening with different sharpening stones on the cutting angle of periodontal curettes (Gracey 5-6), and the influence on root surfaces after debridement and planing. The experimental model consisted of two different phases. In the first, the cutting angles of fifteen stainless steel Gracey 5-6 curettes were analyzed under a scanning electronic microscope after being sharpened with different types of stones. In the second phase, the root surfaces of 25 newly extracted teeth were evaluated with a scanning electronic microscope after being debrided with curettes sharpened with different stones. Analysis of the results showed that the synthetic stones (aluminum oxide and carborundum) are more abrasive and produce more irregular cutting angles, whereas Arkansas stones are less abrasive and produce smoother and more defined cutting angles. There was no significant statistical differences among the five groups tested with regard to the degree of irregularity of the root surfaces after instrumentation.

Scanning electron microscopy evaluation of the effect of etching agents on human enamel surface

Zanet, Caio G.; Arana-Chavez, Victor E.; Fava, Marcelo
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 247-250
ENG
Relevância na Pesquisa
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Acid etching promotes microporosities on enamel surface, which provide a better bonding surface to adhesive materials. The purpose of this study was to comparatively analyze the microstructure of enamel surface after etching with 37% phosphoric acid or with two self-etching primers, Non-rinse conditioner (NRC) and Clearfil SE Bond (CSEB) using scanning electron microscopy. Thirty sound premolars were divided into 3 groups with ten teeth each: Group 1: the buccal surface was etched with 37% phosphoric acid for 15 seconds; Group 2: the buccal surface was etched with NRC for 20 seconds; Group 3: the buccal surface was etched with CSEB for 20 seconds. Teeth from Group 1 were rinsed with water; teeth from all groups were air-dried for 15 seconds. After that, all specimens were processed for scanning electron microscopy and analyzed in a Jeol 6100 SEM. The results showed deeper etching when the enamel surface was etched with 37% phosphoric acid, followed by NRC and CSEB. It is concluded that 37% phosphoric acid is still the best agent for a most effective enamel etching.

Scanning electron microscopic analysis of the effect of Carisolv TM gel on periodontally compromised human root surfaces

Grisi, Daniela Corrêa; Theodoro, Letícia Helena; Sampaio, José Eduardo César; Grisi, Márcio Fernando de Moraes; Salvador, Sérgio Luiz de Souza
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 110-116
ENG
Relevância na Pesquisa
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The aim of this study was to analyze, under scanning electron microscopy (SEM), the morphologic characteristics of root surfaces after application of CarisolvTM gel in association with scaling and root planing (SRP). Sixty periodontally compromised extracted human teeth were randomly assigned to 6 groups: 1) SRP alone; 2) passive topical application of CarisolvTM + SRP; 3) active topical application of CarisolvTM + SRP; 4) multiple applications of CarisolvTM + SRP; 5) SRP + 24% EDTA; 6) topical application of CarisolvTM + SRP + 24% EDTA. CarisolvTM gel was applied to root surfaces for 30 s, followed by scaling and root planing, consisting of 50 strokes with Gracey curettes in an apical-coronal direction, parallel to the long axis of the tooth. The only exception was group 4, in which the roots were instrumented until a smooth, hard and glass-like surface was achieved. All specimens were further analyzed by SEM. The results showed that the treatment with CarisolvTM caused significant changes in root surface morphology of periodontally compromised teeth only when the chemical agent was actively applied (burnishing technique). CarisolvTM failed to remove the smear layer completely, especially with a single application, independently of the method of application. Multiple applications of CarisolvTM were necessary to achieve a smear layer reduction comparable to that obtained with 24% EDTA conditioning.

Scanning electron microscopic and profilometric study of different sharpening stones

Andrade Acevedo, Roberto Antonio; Cardozo, Ana Karina Veloso; Sampaio, José Eduardo César
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 237-242
ENG
Relevância na Pesquisa
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Scaling and root planing contribute to the recovery of periodontal health. All periodontal instruments loose their fine cutting angle after use. To maintain this angle, correct sharpening is required using specifically designed stones. The characteristics of sharpening stones can be compared to the blade of the instruments and also transported to root surface during instrumentation. Root smoothness is related to the quality of the blade. Therefore, the purpose of this study was to evaluate the characteristics of 9 sharpening stones by scanning electron microscopic and profilometric analyses. Ceramic and Neumar stones were very fine and both may be recommended to maintain the sharpness of the instruments. Arkansas, Thompson and CE stones presented greater roughness with very regular and round particles, and are suitable for maintenance of the cutting angle. In addition, these stones may be indicated for the routine sharpening of the instruments that are partly dull. Oxide Aluminum, Carborundum and JON stones were the coarsest with large irregular particles and may be indicated for initial sharpening of totally dull instruments with completion of sharpening with finer stones.

Scanning electron microscopic study of the in situ effect of salivary stimulation on erosion and abrasion in human and bovine enamel

Rios, Daniela; Honório, Heitor Marques; Magalhães, Ana Carolina; da Silva, Salete Moura Bonifácio; Delbem, Alberto Carlos Botazzo; Machado, Maria Aparecida de Andrade Moreira; Buzalaf, Marília Afonso Rabelo
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 132-138
ENG
Relevância na Pesquisa
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This in situ study investigated, using scanning electron microscopy, the effect of stimulated saliva on the enamel surface of bovine and human substrates submitted to erosion followed by brushing abrasion immediately or after one hour. During 2 experimental 7-day crossover phases, 9 previously selected volunteers wore intraoral palatal devices, with 12 enamel specimens (6 human and 6 bovine). In the first phase, the volunteers immersed the device for 5 minutes in 150 ml of a cola drink, 4 times a day (8h00, 12h00, 16h00 and 20h00). Immediately after the immersions, no treatment was performed in 4 specimens (ERO), 4 other specimens were immediately brushed (0 min) using a fluoride dentifrice and the device was replaced into the mouth. After 60 min, the other 4 specimens were brushed. In the second phase, the procedures were repeated but, after the immersions, the volunteers stimulated the salivary flow rate by chewing a sugar-free gum for 30 min. Enamel superficial alterations of all specimens were then evaluated using a scanning electron microscope. Enamel prism core dissolution was seen on the surfaces submitted to erosion, while on those submitted to erosion and to abrasion (both at 0 and 60 min) a more homogeneous enamel surface was observed...

Effect of brushing with conventional versus whitening dentifrices on surface roughness and biofilm formation of dental ceramics

Azevedo, Sarina Maciel Braga; Kantorski, Karla Zanini; Valandro, Luiz Felipe; Bottino, Marco Antonio; Pavanelli, Carlos Augusto
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.1%
The aim of this study was to evaluate the effect of conventional and whitening dentifrices on the weight loss, surface roughness, and early in situ biofilm formation on the surface of dental ceramics. Standardized feldspar ceramic specimens (Vita VM7 and Vita VM13) were submitted to the following experimental conditions: no brushing; brushing without a dentifrice; brushing with a conventional dentifrice; and brushing with a whitening dentifrice. A brushing machine was used to simulate brushing. The mass and surface roughness of all specimens from the test groups were evaluated prior to and after brushing. Ten participants used an oral device for eight hours to evaluate the biofilm formed in situ on the specimens. Scanning electron microscopy was used for qualitative and quantitative analysis of the biofilm. ANOVA and Tukey tests were used to analyze the results of weight loss, surface roughness, and presence of bacteria. A one-way Kruskal-Wallis test was used for bacterial colonization results. For both ceramics, brushing with a whitening dentifrice resulted in weight loss that was significantly greater when compared to brushing without a dentifrice or with a conventional dentifrice. Increased surface roughness was noticed on VM13 ceramic samples with both dentifrices...

Comparative in vivo study of commercially pure Ti implants with surfaces modified by laser with and without silicate deposition: Biomechanical and scanning electron microscopy analysis

Souza, Francisley A.; Queiroz, Thallita P.; Guastaldi, Antônio C.; Garcia-Júnior, Idelmo R.; Magro-Filho, Osvaldo; Nishioka, Renato S.; Sisti, Karin E.; Sonoda, Celso K.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 76-84
ENG
Relevância na Pesquisa
36.18%
The purpose of this study was to evaluate commercially pure titanium implant surfaces modified by laser beam (LS) and LS associated with sodium silicate (SS) deposition, and compare them with machined surface (MS) and dual acid-etching surfaces (AS) modified. Topographic characterization was performed by scanning electron microscopy-X-ray energy dispersive spectroscopy (SEM-EDX), and by mean roughness measurement before surgery. Thirty rabbits received 60 implants in their right and left tibias. One implant of each surface in each tibia. The implants were removed by reverse torque for vivo biomechanical analysis at 30, 60, and 90 days postoperative. In addition, the surface of the implants removed at 30 days postoperative was analyzed by SEM-EDX. The topographic characterization showed differences between the analyzed surfaces, and the mean roughness values of LS and SS were statistically higher than AS and MS. At 30 days, values removal torque LS and SS groups showed a statistically significant difference (p < 0.05) when compared with MS and AS. At 60 days, groups LS and SS showed statistically significant difference (p < 0.05) when compared with MS. At 90 days, only group SS presented statistically higher (p < 0.05) in comparison with MS. The authors can conclude that physical chemistry properties and topographical of LS and SS implants increases bone-implant interaction and provides higher degree of osseointegration when compared with MS and AS. © 2012 Wiley Periodicals...

Analise dos efeitos da interação entre S mutans e materiais restauradores esteticos : caracteristicas do biofilme em microscopio confocal de varredura a laser e propriedades de superficie dos materiais apos 30 dias; Analysis of the interaction between S. mutans and esthetic restorative materials : biofilm chracteristics by confocal laser scanning microscopy and material surface properties after 30 days

Suzana Beatriz Portugal de Fucio
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/02/2007 PT
Relevância na Pesquisa
36.11%
O desenvolvimento do biofilme de Streptococcus mutans sobre materiais restauradores e a biodegradação destes substratos em função dos metabólitos bacterianos podem ser influenciados pelas propriedades e características do material. A partir de uma revisão sistemática em que se verificou a carência de estudos a respeito dos efeitos do biofilme na superfície de materiais restauradores, foi proposto investigar algumas características quantitativas e qualitativas do biofilme após 30 dias de interação com materiais restauradores, além de analisar propriedades e microestrutura da superfície dos materiais que sofreram tal interação. Para cada material testado (cerâmica - C, resina composta nanoparticulada ? RC e cimentos de ionômero de vidro modificado por resina - CIVMR e convencional - CIVC), foram confeccionados 25 discos sob condições assépticas, para distribuição em 3 grupos de estocagem: 1) 100% de umidade relativa a 37ºC (n=5); 2) meio de cultura a 37ºC (BHI + 1% sacarose) (n=5); 3) biofilme de Streptococcus mutans e meio de cultura a 37ºC (n=15). Valores de dureza do grupo 1 (valores imediatos) foram obtidos previamente à estocagem, a fim de se verificar alterações ao longo do tempo quando estocados em umidade relativa apenas. Após 30 dias de estocagem...

Surface finishing of unused rotary endodontic instruments: a SEM study

Chianello,Giovani; Specian,Vivyane Leal; Hardt,Lilian Cristina Fucuda; Raldi,Denise Pontes; Lage-Marques,José Luiz; Habitante,Sandra Márcia
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
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During endodontic therapy, cleaning of root canals is performed using endodontic files and auxiliary chemical substances, and it is important that the endodontist be familiar with the instruments used in daily practice. This study evaluated, under scanning electron microscopy (SEM), the quality of the surface finishing of unused rotary endodontic instruments. Fifty sizes 20, 25 and 30 rotary files from different commercial brands (ProFile, Protaper, Race, Hero and K3 Endo) were removed directly from their packages and had their final 3 mm examined with a scanning electron microscope at x190 magnification with no previous preparation. The images were evaluated by 3 skillful, calibrated, blinded observers according to the following criteria: cutting edge, debris, grooves, microcavities, tip shape, tip position, scraping and transition angle. Data were recorded in worksheets designed for the study. Irregular edges were observed in 50-100% of the files. Except for ProFile, all commercial brands presented surface debris in 100% of samples. Only Race files showed no grooves or microcavities. K3 Endo files presented the best tip centralization. Excetp for ProTaper files, all commercial brands presented blunt-cutting edges in 100% of samples. All types of files presented surface scraping. K3 Endo files and Protaper had a high percentage of transition angle. Based on the evaluation criteria used in the present study...

Minimally Invasive Holographic Surface Scanning for Soft-Tissue Image Registration

Lathrop, Ray A.; Hackworth, Douglas M.; Webster, Robert J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/2010 EN
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46.11%
Recent advances in registration have extended intra-surgical image guidance from its origins in bone-based procedures to new applications in soft tissues, thus enabling visualization of spatial relationships between surgical instruments and subsurface structures before incisions begin. Preoperative images are generally registered to soft tissues through aligning segmented volumetric image data with an intraoperatively sensed cloud of organ surface points. However, there is currently no viable noncontact minimally invasive scanning technology that can collect these points through a single laparoscopic port, which limits wider adoption of soft-tissue image guidance. In this paper, we describe a system based on conoscopic holography that is capable of minimally invasive surface scanning. We present the results of several validation experiments scanning ex vivo biological and phantom tissues with a system consisting of a tracked, off-the-shelf, relatively inexpensive conoscopic holography unit. These experiments indicate that conoscopic holography is suitable for use with biological tissues, and can provide surface scans of comparable quality to existing clinically used laser range scanning systems that require open surgery. We demonstrate experimentally that conoscopic holography can be used to guide a surgical needle to desired subsurface targets with an average tip error of less than 3 mm.

Scanning laser doppler vibrometry for strain measurement and damage detection.

Wildy, Stuart James
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2012
Relevância na Pesquisa
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Numerous strain measurement and damage detection techniques have been developed over the last century. These techniques include strain gauges, digital image correlation, radiography and ultrasonic inspections. All have various advantages, as well as disadvantages, which make each suited to specific applications. With the development of laser Doppler vibrometry, a number of techniques have been established for non-destructive evaluation, such as the measurement of bending strain, as well as damage detection using kinematic parameters, including displacement and curvature. With recent advancements in laser Doppler vibrometry technology (such as 3D scanning laser Doppler vibrometry for three-dimensional displacement measurements, improved velocity decoders and increased spatial resolution) the door has been opened to develop techniques for measuring surface strain from in-plane displacements, as well as the development of new damage detection techniques based on the fundamental principle of deformation:- the governing differential equation of displacement. The extensive literature review contained in this thesis identified a number of gaps in the field, including the evaluation of the accuracy of quasi-static bending strain measurements using current 1D SLDV technology...

A Vertical Coarse Approach Scanning Tunneling Microscope

Drevniok, BENEDICT
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado Formato: 148241447 bytes; application/pdf
EN; EN
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A Pan-style scanning tunneling microscope (STM), with a vertical coarse approach mechanism, was designed, built and tested. The microscope will be operated in ultra-high vacuum and also at cryogenic temperatures (8 K) inside a continuous flow cryostat. Fundamental differences in operating principle exist between the new microscope and the beetle-type inertial sliders [1] that have been the mainstay of the group for the last eight years. While Pan-style microscopes do already exist [2], they remain challenging to build, and an active area of research [3]. This system represents a bold departure from well-trodden paths, and will greatly expand the range of experiments that our group can perform. The operating principles of inertial piezoelectric motors are detailed. Design guidelines for a piezoelectric motor are given, and used in the design of the vertical coarse approach motor. A simple, inexpensive implementation for creating waveforms with an extremely fast fall time is discussed. Motor performance is tested, and a minimum step size of 20nm is found for frequencies ranging from 0 Hz to 3 kHz. The motor operates with high dynamic range: individual 20nm steps can be taken, as well as being able to move at a velocity of 0.4mm s−1. Little is known about the vibrational properties of Pan-style microscopes. Vibrational testing of the microscope revealed the expected scanner bending mode at 1.6 kHz (above the scanner bending mode of our beetles at 1.2 kHz)...

Modification of HF-treated silicon (100) surfaces by scanning tunneling microscopy in air under imaging conditions

Barniol i Beumala, Núria; Pérez Murano, Francesc; Aymerich Humet, Xavier
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //1992 ENG
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The modification of HF‐etched silicon (100) surface with a scanning tunneling microscope(STM) operated in air is studied for the first time in samples subjected to the standard HF etching without the follow‐up rinsing in H2O. The modifications are produced in air under normal STM imaging conditions (V t =−1.4 V and I t =2 nA). The simultaneous acquisition of topographical, current image tunneling spectroscopy and local barrier‐height images clearly shows that the nature of the modification is not only topographical but also chemical. The features produced with a resolution better than 25 nm are attributed to a tip‐induced oxidation enhanced by the presence of fluorine on the surface.

Nanoscale properties of self-assembled and laterally nanostructured surface systems

Paradinas Aranjuelo, Marcos
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2015 ENG
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36.21%
Las microscopías de campo cercano en general (SPM) y la microscopia de fuerzas (SFM) en particular, se han convertido en una poderosa herramienta en nanotecnología, ya que permiten tanto caracterizar como manipular las superficies de los materiales en la nanoescala. En el presente trabajo de investigación se han estudiado las propiedades morfológicas, mecánicas, electrostáticas y de conducción de sistemas autoensamblados y nanoestructurados que incluyen películas delgadas orgánicas y superficies inorgánicas mediante estas técnicas de SPM, SFM y microscopía de efecto túnel (STM), en condiciones de ambiente controlado. Nos centramos principalmente en el uso de técnicas de SFM en modos de operación de contacto, dinámico, microscopía de fuerzas de fricción (FFM), conductividad con SFM (CSFM) y microscopía de sonda Kelvin (KPFM). El manuscrito de la tesis está organizado del siguiente modo: en el capítulo 1 se exponen las motivaciones del trabajo y en el capítulo 2 se hace una pequeña introducción al concepto de autoensamblado y a los sistemas nanoestructurados en los sistemas bajo estudio, películas delgadas orgánicas y superficies inorgánicas. En el capítulo 3 se introducen las distintas técnicas y procedimientos experimentales. Se explican las características generales del SPM...

A Scanning Electron Microscope Study of the Surface Structure of Mineral Pigments, Latices and Thickeners used for Paper Coating on Non-absorbent Substrates

Kugge, C; Craig, Vincent; Daicic, John
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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We investigate the structure of coating layers prepared on non-absorbent substrates using a bench coater, composed of mineral pigments, latex binders and polymeric thickeners and dispersants, using scanning electron microscopy (SEM) that are typical of those used in paper coatings. The main aim of the study is to identify how systematic variations in the composition of the coating, including pigment type (calcium carbonate, clay), the glass transition temperature of the binder, and type (CMC, EHEC) and molecular weight of the polymeric thickener affect the surface features of the coating layer, including surface roughness and porosity and, consequently, gloss. The samples are investigated mainly in conventional high-vacuum SEM mode; however some studies are also performed with the environmental feature (ESEM mode) at higher pressures and humidities, in order to track dynamic changes due to drying and rewetting. The results are compared to those of recent measurements on the same systems obtained with atomic force microscopy (AFM), where the local latex film formation process has been carefully studied.