946 resultados para Non-destructive method
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Waterpower: A Geophysical and Archaeological Investigation of the Waterpower System at the West Point Foundry, Cold Spring, New York, describes the results of ground penetrating radar surveys and archaeological excavation undertaken by Michigan Technological University (MTU) archaeologists during the summer of 2003 at the West Point Foundry, Cold Spring, New York. 2003 constituted MTU's second field season at the foundry. Fieldwork concentrated on the foundry's waterpower system, an intricate network of surface and subsurface drains, races, flumes, waterwheels, turbines, dams, and ponds that powered operations and regulated water flow throughout the site. Archaeologists utilized non-destructive geophysical technology, which expedited survey, facilitated placement of excavation units, and provided a model for future archaeogeophysical research at industrial sites. Features discovered during excavation provided valuable information pertaining to the waterpower system's construction and its functions. Data from ground penetrating radar surveys, archaeological excavation, historical photographs, documents, and maps permitted the development of a provisional chronology of the development of various components of the West Point Foundry's waterpower system. Information gathered during this project serves as an aid in sit interpretation and rehabilitation.
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A wide range of non-destructive testing (NDT) methods for the monitoring the health of concrete structure has been studied for several years. The recent rapid evolution of wireless sensor network (WSN) technologies has resulted in the development of sensing elements that can be embedded in concrete, to monitor the health of infrastructure, collect and report valuable related data. The monitoring system can potentially decrease the high installation time and reduce maintenance cost associated with wired monitoring systems. The monitoring sensors need to operate for a long period of time, but sensors batteries have a finite life span. Hence, novel wireless powering methods must be devised. The optimization of wireless power transfer via Strongly Coupled Magnetic Resonance (SCMR) to sensors embedded in concrete is studied here. First, we analytically derive the optimal geometric parameters for transmission of power in the air. This specifically leads to the identification of the local and global optimization parameters and conditions, it was validated through electromagnetic simulations. Second, the optimum conditions were employed in the model for propagation of energy through plain and reinforced concrete at different humidity conditions, and frequencies with extended Debye's model. This analysis leads to the conclusion that SCMR can be used to efficiently power sensors in plain and reinforced concrete at different humidity levels and depth, also validated through electromagnetic simulations. The optimization of wireless power transmission via SMCR to Wearable and Implantable Medical Device (WIMD) are also explored. The optimum conditions from the analytics were used in the model for propagation of energy through different human tissues. This analysis shows that SCMR can be used to efficiently transfer power to sensors in human tissue without overheating through electromagnetic simulations, as excessive power might result in overheating of the tissue. Standard SCMR is sensitive to misalignment; both 2-loops and 3-loops SCMR with misalignment-insensitive performances are presented. The power transfer efficiencies above 50% was achieved over the complete misalignment range of 0°-90° and dramatically better than typical SCMR with efficiencies less than 10% in extreme misalignment topologies.
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To investigate the validity and reliability of surface electromyography (EMG) as a new non-invasive determinant of the metabolic response to incremental exercise in elite cyclists. The relation between EMG activity and other more conventional methods for analysing the aerobic-anaerobic transition such as blood lactate measurements (lactate threshold (LT) and onset of blood lactate accumulation (OBLA)) and ventilatory parameters (ventilatory thresholds 1 and 2 (VT1 and VT2)) was studied.Twenty eight elite road cyclists (age 24 (4) years; VO2MAX 69.9 (6.4) ml/kg/min; values mean (SD)) were selected as subjects. Each of them performed a ramp protocol (starting at 0 W, with increases of 5 W every 12 seconds) on a cycle ergometer (validity study). In addition, 15 of them performed the same test twice (reliability study). During the tests, data on gas exchange and blood lactate levels were collected to determine VT1, VT2, LT, and OBLA. The root mean squares of EMG signals (rms-EMG) were recorded from both the vastus lateralis and the rectus femoris at each intensity using surface electrodes. Results - A two threshold response was detected in the rms-EMG recordings from both muscles in 90% of subjects, with two breakpoints, EMG(T1) and EMG(T2), at around 60-70% and 80-90% of VO2MAX respectively. The results of the reliability study showed no significant differences (p > 0.05) between mean values of EMG(T1) and EMG(T2) obtained in both tests. Furthermore, no significant differences (p > 0.05) existed between mean values of EMG(T1), in the vastus lateralis and rectus femoris, and VT1 and LT (62.8 (14.5) and 69.0 (6.2) and 64.6 (6.4) and 68.7 (8.2)% of VO2MAX respectively), or between mean values of EMG(T2), in the vastus lateralis and rectus femoris, and VT2 and OBLA (86.9 (9.0) and 88.0 (6.2) and 84.6 (6.5) and 87.7 (6.4)% of VO2MAX respectively). Rms-EMG may be a useful complementary non-invasive method for analysing the aerobic-anaerobic transition (ventilatory and lactate thresholds) in elite cyclists.
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Otoliths and scales were used to determine age and growth of: Boops boops (Linnaeus, 1758), Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817), Diplodus sargus (Linnaeus, 1758), Lithognathus mormyrus (Linnaeus, 1758), Pagellus acarne (Risso, 1827), Pagellus erythrinus (Linnaeus, 1758) and Spondyliosoma cantharus (Linnaeus, 1758). These structures came from previous studies conducted in southern Portugal, and complemented by market sampling and beach seining. Von Bertalanffy growth functions were estimated with otolith and scale readings. Results indicate that otoliths are better structures for ageing these species but scales can also be used as a non-destructive technique and with satisfactory results. The exceptions were R erythrinus and S. cantharus for which scales provided better results. (c) 2007 Elsevier B.V. All rights reserved.
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Este estudio de caso analiza las razones por las cuales México adelantó una reforma constitucional en materia energética en 2013, y el interés que tuvo Estados Unidos en esta, puesto que se destaca la intención del gobierno estadounidense de convertir a América del Norte en una región más sólida. Es así como se exponen las razones por las cuales México decide reformar su constitución y por esa vía tener un impacto directo en Petróleos Mexicanos (Pemex), la cual es la mayor compañía del país, encargada de adelantar los procesos de exploración y explotación de hidrocarburos. Asimismo, se explica el interés de Estados Unidos en el tema del intercambio de hidrocarburos, ya que es primordial para lograr la seguridad energética en Norteamérica, una región donde se está realizando extracción de gas y petróleo a través del fracking, un método no convencional, que ha propiciado un nuevo panorama en los recursos energéticos.
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Neste trabalho foram estudadas quatro espécies fotográficas, dois ambrótipos do séc. XIX e dois negativos de gelatina do séc. XX. Estas espécies são suscetiveis a degradações, físicas, químicas e microbiológicas. Técnicas de análise não destrutivas como, a fotografia, a microscopia ótica, a microscopia eletrónica de varrimento e espetroscopia de raios-X por dispersão em energias, a micro-espetroscopia de infravermelho em modo de reflexão total atenuada, a micro-espetroscopia de Raman e a micro-difração de raios-X foram utilizadas na caracterização material. A colonização microbiológica das amostras foi estudada através do isolamento e caracterização dos microrganismos contaminantes. Foram ainda realizados estudos de determinação de atividade celulolítica para os isolados fúngicos provenientes dos ambrótipos bem como ensaios de simulação, nos quais se utilizaram estes isolados para induzir contaminação em ambrótipos contemporâneos e assim avaliar o seu potencial biodeteriogénico. Foi ainda avaliado o potencial biodeteriogénico de isolados bacterianos em negativos de gelatina contemporâneos; Abstract: Material and microbiological characterization of photographic specimens This work presents a scientific study of four photographic specimens, two ambrotypes and two gelatin-silver negative plates from 19th and 20th century, respectively. These specimens are susceptible to physical, chemical and microbiological degradations. A non-destructive approach was used based on techniques such as technical photography, optical microscopy, scanning electron microscopy, infrared micro-spectroscopy, micro-Raman spectroscopy and X-rays micro-diffraction. Microbiological colonization of the samples was studied by isolation and characterization of the contaminating microorganisms. Studies to evaluate cellulolytic activity of fungal isolates from the ambrotypes were carried out and also simulation assays in which were used these isolated to induce contamination in contemporary ambrotypes were done to evaluate their biodeteriogenic potential. It was also studied the biodeteriogenic potential of the bacterial isolates from gelatin-silver negative plates which were subsequently inoculated in contemporary gelatin-silver negatives.
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The Opuntia ficus-indica (L.) Miller is a species from the Cactaceae family with the center of origin and domestication in central Mexico. This species introduction in the Iberia Peninsula occurred, probably, by the end of the 15th century, after the discovery of America, spreading later throughout the Mediterranean basin. In Portugal, O. ficus-indica is located, usually, with a typical ruderal behavior, at the edge of roads and paths. In Portugal, as in other Mediterranean regions, inlands areas are under severe draught during extensive summers, in particular, and global warming is expected to affect them deeply in the near future. O. ficus-indica, by its morpho-physiological characteristics and multiple economic uses, represent an alternative crop for those regions. Sixteen Portuguese O. ficus indica ecotypes and two ‘Italian’ cultivars ("Gialla" and "Bianca") were evaluated for plant vigor and biomass production, by nondestructive methods, in the two years following planting. Biomass production and plant vigor were measured by estimating cladode number, cladode area and fresh weight per plant. Linear models to predict the area of cladodes and fresh weight per plant were previously established using a biometric analysis of 180 cladodes. It was not possible to establish an accurate linear model for dry matter using non-destructive estimation. Significant differences were found among populations in the studied biomass-related parameters, and different groups were unfolded. A group of four Portuguese ecotypes outperformed in terms of biomass production, comparable with the “Gialla” cultivar. This group could be used to start a breeding program with the objective of deploy material for animal feeding, biomass and fruit production. Nevertheless, the ‘Gialla’ cultivar showed the best performance, achieving the highest biomass related parameters, not surprisingly for it is an improved plant material.
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The aim of this work was in first place to define a methodology for the use of Py-GC/MS as a characterization technique for the organic compounds present in paper samples containing foxing stains, paper have a complex structure and mostly consist with cellulose fibers. Additionally, it was intent to characterize paper samples containing foxing stains with a batch of non-destructive analytical techniques. The work intent to deepen our knowledge on foxing stains, its chemical nature and morphological aspects. For characterization of the morphology of paper samples and foxing stains was used photography under different illuminations and optical microscopy. The presence of fibers disruption was observed with scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), and also the nature of the fillers that is present in different areas. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) was used for identification of the sizing agents, determination of the chemical composition of additives that were used for production of paper, and comparison between foxing stains and unfoxed areas was allowed. Micro X-ray diffraction was used to evaluate the crystalline fillers in the sample. Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS was used for chemical analysis to identify the organic components and different classes of organic compounds; Resumo: O objetivo deste trabalho foi definir, em primeiro lugar, uma metodologia para o uso de Py-GC / MS como técnica de caracterização dos compostos orgânicos presentes em amostras de papel contendo manchas de foxing, o papel tem uma estrutura complexa e consiste principalmente com fibras de celulose. Além disso, pretendia caracterizar amostras de papel contendo manchas de raposas com técnicas analíticas não destrutivas. Para a caracterização da morfologia das amostras de papel e das manchas de foxing foi usada fotografia sob diferentes iluminações e microscopia óptica. A presença de fibras de ruptura foi observada por microscopia electrónica de varrimento juntamente com espectroscopia dispersiva de energia (EDS-SEM), assim como a natureza dos materiais de enchimento que está presente em diferentes áreas. Espectroscopia de infravermelho com transformada de Fourier em modo de reflexão total atenuada (ATR-FTIR) foi utilizada na identificação dos agentes de colagem, e na determinação da composição química de aditivos usados na produção de papel, e a comparação entre foxing manchas e áreas unfoxed foi deixada. Micro difracção de raios X foi usada para avaliar o enchimentos cristalinos na amostra. Cromatografia pirólise-gasosa / espectrometria de massa (Py-GC / MS) foi utilizada para análise química para identificar os componentes orgânicos e diferentes classes de compostos orgânicos.
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The present work was done on two ambrotypes and two tintypes. It aimed evaluate their chemical and physical characteristics, especially their degradation patterns. Moreover, to understand the materials used for their production and cross-check analytical and historical information about the production processes. To do so multi-analytical, non-destructive methods were applied. Technical photography highlighted the surface morphology of the objects and showed the distribution of the protective coatings on their surfaces through UV radiation, which were very different between the four pieces. OM allowed for a detailed observation of the surfaces along with the selection of areas of interest to be analysed with SEM-EDS. SEM-EDS was the technique used most extensively and the one that provided the most insightful results: it allowed to observe the morphology of the image forming particles and the differences between highlights, dark areas and the interfaces between them. Also, elemental point analysis and elemental maps were used to identify the image forming particles as silver and to detect the presence of compounds related to the production, particularly gold used to highlight jewellery, iron as the red pigment and traces of the compounds used in the photographic process containing Ag, I, Na and S . Also, some degradation compounds were analysed containing Ag, Cu, S and Cl. With μ-FT-IR the presence of collodion was confirmed and the source of the protective varnishes was identified, particularly mastic and shellac, in either mixtures of the two or only one. μ-Raman detected the presence of metallic silver and silver chloride on the objects and identified one of the red pigments as Mars red. Finally, μ-XRD showed the presence of metallic silver and silver iodide on both ambrotypes and tintypes and hematite, magnetite and wuestite on the tintypes; RESUMO: O presente estudo foi desenvolvido sobre dois ambrótipos e dois ferrótipos. O propósito consiste em estudar as suas características químicas e físicas, dando particular ênfase aos padrões de degradação. Também é pretendido compreender os materiais usados na sua produção e relacionar esta informação analítca com dados históricos de manuais técnicos contemporâneos à produção dos objectos. Para tal foram utilizadas técnicas multi-analíticas e não destrutivas. O uso da fotografia técnica permitiu uma observação da morfologia das superficies dos objectos e da distribuição das camadas de verniz através da radiação UV, muito diferente entre os quatro. A microscopia óptica proporcionou uma observação detalhada das superfícies assim como a selecção de pontos de interesse para serem analisados com SEM-EDS. SEM-EDS foi a técnica usada mais extensivamente e a que proporcionou os resultados mais detalhados: observação da morofologia das partículas formadoras da imagem e as diferenças entre zonas de altas luzes, baixas luzes e as interfaces entre elas. A análise elemental e os mapas elementares foram usados para detectar prata nas partículas formadoras da imagem e a presença de compostos relacionados com a produção, em particular ouro utilizado para realçar joalharia, ferro no pigmento vermelho e vestígios de compostos utilizados no processo fotográfico incluindo Ag, I, Na e S. Do mesmo modo, alguns compostos de degradação foram analisados contendo Ag, Cu, S e Cl. Com μ-FT-IR a presença de colódio foi confirmada e identificada a origem dos vernizes, mástique e goma-laca, tanto em misturas dos dois como apenas um. Com μ-Raman foi detectada a presença de prata metálica e de cloreto de prata e identificado um dos pigmentos vermelhos como Mars red. Finalmente, μ-DRX revelou a presença de prata metálica e iodeto de prata tanto nos ambrótipos como nos ferrótipos e hematite, magnetite e wuestite nos ferrótipos.
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The near infrared (NIR) spectroscopy presents itself as an interesting non-destructive test tool as it enables a fast, simple and reliable way for characterizing large samplings of biological materials in a short period of time. This work aimed to establish multivariate models to estimate the crystallinity indices and tensile and burst strength of cellulosic and nanocellulosic films through NIR spectroscopy. NIR spectra were recorded from the films before tensile and bursting strength, and crystallinity tests. Spectral information were correlated with reference values obtained by laboratory procedures through partial least square regression (PLS-R). The PLS-R model for estimating the crystallinity index presented a coefficient of determination in cross-validation (R2cv) of 0,94 and the ratio of performance to deviation (RPD) was 3,77. The mechanical properties of the films presented a high correlation with the NIR spectra: R2p = 0,85 (RPD = 2,23) for tensile and R2p = 0,93 (RPD = 3,40) for burst strength. The statistics associated to the models presented have shown that the NIR spectroscopy has the potential to estimate the crystallinity index and resistance properties of cellulose and nanocellulose films on in-line monitoring systems.
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Cultural heritage is constituted by complex and heterogenous materials, such as paintings but also ancient remains. However, all ancient materials are exposed to external environment and their interaction produces different changes due to chemical, physical and biological phenomena. The organic fraction, especially the proteinaceous one, has a crucial role in all these materials: in archaeology proteins reveal human habits, in artworks they disclose technics and help for a correct restoration. For these reasons the development of methods that allow the preservation of the sample as much as possible and a deeper knowledge of the deterioration processes is fundamental. The research activities presented in this PhD thesis have been focused on the development of new immunochemical and spectroscopic approaches in order to detect and identify organic substances in artistic and archaeological samples. Organic components could be present in different cultural heritage materials as constituent element (e.g., binders in paintings, collagen in bones) and their knowledge is fundamental for a complete understanding of past life, degradation processes and appropriate restauration approaches. The combination of immunological approach with a chemiluminescence detection and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry allowed a sensitive and selective localization of collagen and elements in ancient bones and teeth. Near-infrared spectrometer and hyper spectral imaging have been applied in combination with chemometric data analysis as non-destructive methods for bones prescreening for the localization of collagen. Moreover, an investigation of amino acids in enamel has been proposed, in order to clarify teeth biomolecules survival overtime through the optimization and application of High-Performance Liquid Chromatography on modern and ancient enamel powder. New portable biosensors were developed for ovalbumin identification in paintings, thanks to the combination between biocompatible Gellan gel and electro-immunochemical sensors, to extract and identify painting binders with the contact only between gel and painting and between gel and electrodes.
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In recent years, composite materials have revolutionized the design of many structures. Their superior mechanical properties and light weight make composites convenient over traditional metal structures for many applications. However, composite materials are susceptible to complex and challenging to predict damage behaviors due to their anisotropy nature. Therefore, structural Health Monitoring (SHM) can be a valuable tool to assess the damage and understand the physics underneath. Distributed Optical Fiber Sensors (DOFS) can be used to monitor several types of damage in composites. However, their implementation outside academia is still unsatisfactory. One of the hindrances is the lack of a rigorous methodology for uncertainty quantification, which is essential for the performance assessment of the monitoring system. The concept of Probability of Detection (POD) must function as the guiding light in this process. However, precautions must be taken since this tool was established for Non-Destructive Evaluation (NDE) rather than Structural Health Monitoring (SHM). In addition, although DOFS have been the object of numerous studies, a well-established POD methodology for their performance assessment is still missing. This thesis aims to develop a methodology to produce POD curves for DOFS in composite materials. The problem is analyzed considering several critical points, such as the strain transfer characterizing the DOFS and the development of an experimental and model-assisted methodology to understand the parameters that affect the DOFS performance.
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Il Mieloma Multiplo (MM) è una patologia neoplastica delle cellule B caratterizzata dalla proliferazione di più cloni di plasmacellule portatrici di diverse anomalie genomiche. Il MM presenta tipicamente un’eterogeneità genomica spaziale e intraclonale, che rende l’aspirato midollare "a singolo sito", attualmente utilizzato per la valutazione della malattia residua (MRD) dopo trattamento, non realmente informativo sulla taglia di malattia e sul panorama genomico della malattia. In considerazione della crescente importanza che sta assumendo la valutazione della MRD, i test per monitorarla dovrebbero essere non invasivi, affidabili e in grado di rappresentare le eterogeneità che caratterizzano il MM. Il presente studio ha permesso di dimostrare la possibilità di utilizzare la biopsia liquida, una metodica innovativa e non invasiva, per caratterizzare i pazienti con MM attivo o con MM smoldering ad alto rischio di evoluzione (HR-SMM) e per determinale l’MRD nei pazienti sottoposti a terapia di prima linea, integrando le metodiche attualmente validate. Nei pazienti arruolati nel presente studio è stato possibile identificare la frazione tumorale di DNA libero circolante (cfDNA-TF) nel sangue periferico, ed è stato possibile caratterizzare la malattia da un punto di vista qualitativo, dimostrando un’elevata concordanza del profilo genomico tra DNA libero circolante e DNA midollare (100% nei pazienti con HR-SMM e 86% nei pazienti con MM attivo). L’esecuzione seriata di biopsie liquide in corso di terapia, con un follow-up mediano di 24 mesi, ha mostrato una rapida e netta riduzione della cfDNA-TF xdalle prime fasi di terapia, con una tendenza a mantenersi mediamente sotto la soglia di sensibilità della metodica anche nelle fasi successive, indipendentemente dall’eventuale persistenza di MRD individuabile a livello midollare o mediante PET-CT. Con un follow-up più lungo probabilmente sarà possibile valutare meglio la capacità di questa metodica di affiancare o eventualmente sostituire l’aspirato midollare.
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Il monitoraggio basato su emissioni acustiche (AE) guidate si è confermato tra le tecniche più affidabili nel campo del Non-Destructive Testing delle strutture planari, vista anche la sua semplicità implementativa, i bassi costi che lo caratterizzano, la non invasività e la possibilità di realizzare un sistema che agisca in maniera continuativa ed in tempo reale sfruttando reti di sensori permanentemente installati, senza la necessità di ispezioni periodiche. In tale contesto, è possibile sfruttare l’abilità dell’apprendimento automatico nell’individuazione dei pattern nascosti all’interno dei segnali grezzi registrati, ottenendo così informazioni utili ai fini dell’applicazione considerata. L’esecuzione on-edge dei modelli, ovvero sul punto di acquisizione, consente di superare le limitazioni imposte dal processamento centralizzato dei dati, con notevoli vantaggi in termini di consumo energetico, tempestività nella risposta ed integrità degli stessi. A questo scopo, si rivela però necessario sviluppare modelli compatibili con le stringenti risorse hardware dei dispositivi a basso costo tipicamente impiegati. In questo elaborato verranno prese in esame alcune tipologie di reti neurali artificiali per l’estrazione dell’istante di arrivo (ToA) di un’emissione acustica all’interno di una sequenza temporale, in particolare quelle convoluzionali (CNNs) ed una loro variante più recente, le CapsNet basate su rounting by agreement. L’individuazione dei ToA relativi al medesimo evento su segnali acquisiti in diverse posizioni spaziali consente infatti di localizzare la sorgente da cui esso è scaturito. Le dimensioni di questi modelli permettono di eseguire l’inferenza direttamente su edge-device. I risultati ottenuti confermano la maggiore robustezza delle tecniche di apprendimento profondo rispetto ai metodi statistici tradizionali nel far fronte a diverse tipologie di disturbo, in particolare negli scenari più critici dal punto di vista del rapporto segnale-rumore.
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Aim: This clinical report presents a new method for retrieving separated instruments from the root canal with minimally invasive procedures. Background: The presence of separated instrument in root canal may interfere in the endodontic treatment prognosis. There are several recommended methods to retrieve separated instruments, but some are difficult in clinically practice. Case report: This study describes two cases of separated instrument removal from the root canal using a stainless-steel prepared needle associated with a K-file. Case 1 presented a fractured gutta-percha condenser within the mandibular second premolar, it was separated during incorrect intracanal medication calcium hydroxide placement. Case 2 had a fractured sewing needle within the upper central incisor that the patient used to remove food debris from the root canal. After cervical preparation, the fractured instruments were fitted inside a prepared needle and then an endodontic instrument (#25 K-file) was adapted with clockwise turning motion between the needle inner wall and the fragment. Conclusion: The endodontic or atypical nonendodontic separated instrument may be easily pull on of the root canal using a single and low cost device. Clinical significance: The methods for retrieving separated instruments from root canal are difficult and destructive procedures. The present case describes a simple method to solve this problem.