Dissertationen: „Sensing element“

1

Miller, Dawn Elizabeth. „Underground cable fault location using multi-element gas sensing“. Thesis, University of Manchester, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.681492.

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2

Curtis, Andrew W. 1970. „A nonlinearly compliant transmission element for force sensing and control“. Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/89260.

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3

St, Quintin Andra. „Electron beam lithography of a diffractive element for surface plasmon resonance sensing“. Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114573.

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Surface plasmon resonance (SPR) sensing is seen as a viable option for developing biological sensors that provide portable, real-time, integrated detection systems. Certain implementations of this sensing technique have already been commercialized, but there is a continued trend to provide systems that are ever-more compact and integrated. In accordance with this trend, previous work has designed a multi-channel SPR device which relies on diffractive lenses to couple light to and from its sensing spots. This thesis presents the development of a fabrication process for these lenses using electron beam lithography, and presents optical results from a prototype device. The fabrication process is demonstrated to provide a high degree of control for pattern alignment and for the size of fabricated features. The developed method is then used to create a reflective diffractive lens on a silicon substrate. The diffraction efficiency of the lens is measured to be approximately 18%, and the focal spot size of the lens is in accordance with predictions based upon the fabricated profile.
La résonance plasmonique de surface (SPR) est considérée comme une option convenable pour le développement de capteurs biologiques offrant un système de détection portatif, en temps réel et intégré. Certains instruments utilisant cette technique de détection ont déjà été commercialisés; cependant, la tendance se maintient pour le développement de systèmes qui sont encore plus compacts et intégrés. Dans cette même direction, un dispositif SPR à multiples canaux basé sur des lentilles diffractives pour focaliser la lumière vers et depuis les régions de détection a été conçu précédemment. Cette thèse présente la conception d'un procédé de fabrication pour ces lentilles utilisant la lithographie par faisceau d'électrons ainsi que les résultats optiques obtenus avec un prototype. Il est démontré que le procédé de fabrication permet un grand contrôle de l'alignement du motif et de la taille des détails. La méthode conçue est ensuite utilisée pour créer une lentille diffractive et réflective sur un substrat de silicium. L'efficacité de diffraction de la lentille est de 18% environ et la taille du faisceau au foyer est en accord avec les prédictions basées sur le profile de fabrication.

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4

Xu, Zhi-Hui. „Mechanical Characterisation of Coatings and Composites-Depth-Sensing Indentation and Finite Element Modelling“. Doctoral thesis, KTH, Materials Science and Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3770.

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In the past two decades depth-sensing indentation has becomea widely used technique to measure the mechanical properties ofmaterials. This technique is particularly suitable for thecharacterisation of materials at sub-micro or nano scale thoughthere is a tendency to extend its application to the micro ormacro scale. The load-penetration depth curve of depth-sensingindentation is a characteristic of a material and can be usedfor analysing various mechanical properties in addition tohardness. This thesis deals with the mechanicalcharacterisation of bulk materials, thin films and coatings,gradient materials, and composites using depth-sensingindentation. Finite element method has been resorted to as atool to understand the indentation behaviour of materials.

The piling-up or sinking-in behaviour of materials plays animportant role in the accurate determination of materialsproperties using depth-sensing indentation. Finite elementsimulations show that the piling-up or sinking-in behaviour isdetermined by the material parameters, namelyE/σyratio and strain hardening exponent orexperimental parameterhe/hmaxratio, and the contact friction. Anempirical model has been proposed to relate the contact area ofindentation to theE/σyratio and thehe/hmaxratio and used to predict thepiling-up orsinking-in of materials. The existence of friction is found toenhance the sinking-in tendency of materials. A generalrelationship between the hardness and the indentationrepresentative stress valid for both soft and hard materialshas been obtained. A possible method to estimate the plasticproperties of bulk materials has been suggested.

Measuring the coating-only properties requires theindentation to be done within a critical penetration depthbeyond which substrate effect comes in. The ratio of thecritical penetration depth to the coating thickness determinedby nanoindentation is independent of coating thickness andabout 0.2 for gold / nickel, 0.4 for aluminium / BK7 glass, and0.2 for diamond-like-carbon / M2 steel and alumina / nickel.Finite element simulations show that this ratio is dependent onthe combination of the coating and the substrate and moresensitive to differences in the elastic properties than in theplastic properties of the coating/substrate system. Thedeformation behaviour of coatings, such as, piling-up of thesoft coatings and cracking of the hard coatings, has also beeninvestigated using atomic force microscope.

The constraint factors, 2.24 for WC phase and 2.7 for WC-Cocemented carbides, are determined through nanoindentation andfinite element simulations. A modified hardness model of WC-Cocemented carbides has been proposed, which gives a betterestimation than the Lee and Gurland hardness model. Finiteelement method has also been used to investigate theindentation behaviour of WC-Co gradient coatings.

Keywords:depth-sensing indentation, nanoindentation,finite element method, atomic force microscope, mechanicalproperties, hardness, deformation, dislocations, cracks,piling-up, sinking-in, indentation size effect, thin coatings,composite, gradient materials, WC-Co, diamond-like-carbon,alumina, gold, aluminium, nickel, BK7 glass, M2 steel.

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Tu, Minh Hieu. „Investigation of metal nanomaterials as a sensing element in LSPR-based optical fibre sensor development“. Thesis, City University London, 2014. http://openaccess.city.ac.uk/5919/.

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This thesis aims to explore and demonstrate the potential of using optical fibres both as a waveguide material and a transducer for wide sensing applications, based on a comprehensive review of the localised surface plasmon resonance (LSPR) phenomenon, which occurs at a nanoscale level when light interacts with metallic nanoparticles at a resonance wavelength. The LSPR effect of metallic nanomaterials has shown a strong dependence on the local surrounding environment. A small change for example in the refractive index or in the solution concentration can result in a variation in the LSPR spectrum. Based on this underpinning sensing mechanism, a portable system using an optical fibre coated with gold nanoparticles (AuNPs) as a sensing probe has been developed and tested for the refractive index measurement. Coupled with this, a systematic approach has been developed and applied in this work to optimize the performance of the developed system by considering several key factors, such as the size of nanoparticles produced, pH, coating time and coating temperature. The above optimised probes coated with gold-nanoparticles are further cross-compared with those optimized but coated with gold nanorods with a high aspect ratio. Both types of probes are also prepared for a specific biosensing application based on the antibody-antigen interaction to create wavelength-based sensors for the detection of anti-human IgG. Both probes have exhibited excellent refractive index (RI) sensitivity, showing ~914 nm/RIU (refractive index unit) for the probe coated with gold nanoparticles and ~601 nm/RIU for the one coated with gold nanorods. When using the modified probes for the detection of anti-human IgG, both probes are able to achieve a good LOD (limit of detection) at 1.6 nM. Based on the above cross-comparison, further research has been undertaken to explore the potential of nanoparticles of the alloy of gold and silver, with an aim to combine the robustness of gold and the excellent LSPR effect of silver. To do so, various alloy particles with varied gold/silver ratio and sizes have been prepared and tested for their respective refractive index sensitivities. The probe coated with alloy particles with bigger size and higher silver content has shown better performance in RI sensing. The work has shown a clear relationship between the size of alloys, the content ratio of alloys and RI sensitivity. Research has also been undertaken in this thesis to explore the excellent LSPR effect of hollow nanoparticles resulting from the enhanced coupling between the interior and exterior of the hollow particles. Gold hollow nanocages have been successfully synthesised and tested with different hollowness and a LSPR sensor coated with gold nanocages has shown an excellent sensitivity as high as ~1933 nm/RIU, which is more than 3 times higher than that coated with AuNPs. This result has confirmed that a significant improvement in sensitivity can be made possible for further biosensing as well as chemical sensing applications.

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Нагорний, Сергій Сергійович, Сергей Сергеевич Нагорный und Serhii Serhiiovych Nahornyi. „Formation of the sensing element of the magnetic field sensor based on Cu and Cu“. Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/46858.

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To form the sensing elements of the magnetic field sensors based on magneto-resistance effect, it was suggested to use a method of layer condensation in vacuum Co and Cu with the thickness of individual layers from 1 to 20 nm and sequence depending on the functionality of the finished sensitive element. For high-speed digital sensors, it is reasonable to form multilayer nanostructures of a spin-valve “sandwich” type Co(4÷12nm)/Cu(4÷8 nm)/Co(20 nm)/S (S - substrate). Co magneto-rough lower layer is additionally secured by high temperature of substrate TS = 950 K which provides high values of lower layer coercitivity Co. The sensor element based on such a multilayer structure depending on the applied external magnetic field can be located in two states “high” and “low” value of resistance that can provide a stable state of logic “zero” and “unity.”

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Lundman, Sara, und Patrick Parnéus. „Virtual Sensing for Fatigue Assessment of the Rautasjokk Bridge“. Thesis, KTH, Bro- och stålbyggnad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231441.

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This thesis treats virtual sensing for fatigue assessment of steel bridges. The purpose is to develop avirtual sensing method to use in the fatigue assessment process. The aim for the virtual sensing method is to only depend on strain measurements located on the bridge structure. The service life of bridges is often limited by fatigue and amending bridge design to improve fatigue resistance was developed in the 1970s. There are several bridges in Sweden, Europe and other countries that have exceeded their theoretical service life with regard to fatigue, and the need to replace them isboth a environmental and economical issue. The bridge over Rautasjokk north of Kiruna, Sweden is a specific example where the theoretical service life is limited by fatigue. Uncertainties in the theoretical fatigue assessment of bridges can be reduced by measuring strains atthe fatigue critical details, and therefore lead to a longer theoretical service life. Monitoring is, however,an expensive method and the procedure of installation and administration requires working time, and monitoring can only provide information at the gauge location. Hence, it is of great interest to optimizethe monitoring system. Virtual sensing is a method that could provide an alternative to conventionalmeasuring techniques. Virtual sensing combine measurement data with information from a model. Virtual sensing for fatigue assessment of the Rautasjokk Bridge was evaluated developing two methods. Both methods uses a finite element model of the bridge combined with strain measurements. The measurements were obtained on February 14 2018 and included a time signal and strain variations at six different locations of the structure. The accuracy of the virtual sensing methods were evaluated by comparing the fatigue damage of virtual sensing with the fatigue damage calculated using measured strains. The fatigue calculations were based on methods presented in the Eurocode EN-1993-1-9. The first method was based on the idea to find a relation between groups of stress ranges for two gauge locations on the bridge. The stress ranges were established by loading influence lines obtained from the finite element model with a fictitious train and the difference between two gauges was stored in a vector, the correlation vector. The correlation vector was applied on the measured stress ranges of the first gauge to estimate the actual stress ranges of the second gauge. No relation between groups of stress ranges for different loading cases was found and the correlation vector method for virtual sensing is not a sufficiently accurate method to apply in the fatigue assessment of the Rautasjokk Bridge. The second method was based on finding a relation between each stress range instead of a group of stress ranges. Influence lines from the finite element model were used to find a relation between each stress range of two gauges. Their relation was stored in a matrix, the correlation matrix. The matrix was applied on the measured stress ranges of the first gauge to estimate the actual stress ranges of the second gauge. The correlation matrix method for virtual sensing estimate the fatigue damage sufficiently accurate at the bridge locations where local stress ranges have the greatest impact on the fatigue damage. Results obtained through virtual sensing only include the same parameters that were used as inputs in the method. A credible virtual sensing method is crucial in order to achieve reliable results. In general, a virtual sensing method requires an extent amount of input data to validate its reliability. Further studies are required to investigate how the uncertainties of the correlation matrix affect the fatigue assessment.

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Anyintuo, Thomas Becket. „Seepage-Coupled Finite Element Analysis of Stress Driven Rock Slope Failures for BothNatural and Induced Failures“. Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7731.

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Rock slope failures leading to rock falls and rock slides are caused by a multitude of factors, including seismic activity, weathering, frost wedging, groundwater and thermal stressing. Although these causes are generally attributed as separate causes, some of them will often act together to cause rock slope failures. In this work, two of the above factors, seepage of water through cracks and crack propagation due to the after effects of blasting are considered. Their combined impact on the development of rock falls and rock slides is modeled on ANSYS workbench using the Bingham Canyon mine slope failure of 2013 as a case study. Crack path modeling and slope stability analysis are used to show how a combination of crack propagation and seepage of water can lead to weakening of rock slopes and ultimate failure. Based on the work presented here, a simple approach for modeling the development of rock falls and rock slides due to crack propagation and seepage forces is proposed. It is shown how the information from remote sensing images can be used to develop crack propagation paths. The complete scope of this method involves demonstrating the combination of basic remote sensing techniques combined with numerical modeling on ANSYS workbench.

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9

Craig, Mark. „Advanced condition monitoring to predict rolling element bearing wear using multiple in-line and off-line sensing“. Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/185079/.

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10

Bane, Danielle Nichole. „A Resonant Capacitive Test Structure for Biomolecule Sensing“. University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1437658452.

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11

Pandey, Bipin. „Self-organized nanoporous materials for chemical separations and chemical sensing“. Diss., Kansas State University, 2013. http://hdl.handle.net/2097/16274.

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Doctor of Philosophy
Department of Chemistry
Takashi Ito
Self-organized nanoporous materials have drawn a lot of attention because the uniform, highly dense, and ordered cylindrical nanopores in these materials provide a unique platform for chemical separations and chemical sensing applications. Here, we explore self-organized nanopores of PS-b-PMMA diblock copolymer thin films and anodic gallium oxide for chemical separations and sensing applications. In the first study, cyclic voltammograms of cytochrome c on recessed nanodisk-array electrodes (RNEs) based on nanoporous films (11, 14 or 24 nm in average pore diameter; 30 nm thick) derived from polystyrene-poly(methylmethacrylate) diblock copolymers were measured. The faradic current of cytochrome c was observed on RNEs, indicating the penetration of cytochrome c (hydrodynamic diameter ≈ 4 nm) through the nanopores to the underlying electrodes. Compared to the 24-nm pores, the diffusion of cytochrome c molecules through the 11- and 14-nm pores suffered significantly larger hindrance. The results reported in this study will provide guidance in designing RNEs for size-based chemical sensing and also for controlled immobilization of biomolecules within nanoporous media for biosensors and bioreactors. In another study, conditions for the formation of self-organized nanopores of a metal oxide film were investigated. Self-organized nanopores aligned perpendicular to the film surface were obtained upon anodization of gallium films in ice-cooled 4 and 6 M aqueous H2SO4 at 10 V and 15 V. The average pore diameter was in the range of 18 ~ 40 nm, and the anodic gallium oxide was ca. 2 µm thick. In addition, anodic formation of self-organized nanopores was demonstrated for a solid gallium monolith incorporated at the end of a glass capillary. Nanoporous anodic oxide monoliths formed from a fusible metal will lead to future development of unique devices for chemical sensing and catalysis. In the final study, surface chemical property of self-organized nanoporous anodic gallium oxide is explored through potentiometric measurements. The nanoporous anodic and barrier layer gallium oxide structures showed slow potentiometric response only at acidic pH (≤ 4), in contrast to metallic gallium substrates that exhibited a positive potentiometric response to H⁺ over the pH range examined (3-10). The potentiometric response at acidic pH probably reflects some chemical processes between gallium oxide and HCl.

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Husain, Muhammad Dawood. „Development of temperature sensing fabric“. Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/development-of-temperature-sensing-fabric(0e5e8367-c3b2-4cff-bcc9-f32fac97b50f).html.

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Human body temperature is an important indicator of physical performance and condition in terms of comfort, heat or cold stress. The aim of this research was to develop Temperature Sensing Fabric (TSF) for continuous temperature measurement in healthcare applications. The study covers the development and manufacture of TSF by embedding fine metallic wire into the structure of textile material using a commercial computerised knitting machine. The operational principle of TSF is based on the inherent propensity of a metal wire to respond to changes in temperature with variation in its electrical resistance. Over 60 TSF samples were developed with combinations of different sensing elements, two inlay densities and highly textured polyester yarn as the base material. TSF samples were created using either bare or insulated wires with a range of diameters from 50 to 150 μm and metal wires of nickel, copper, tungsten, and nickel coated copper. In order to investigate the Temperature-Resistance (T-R) relationship of TSF samples for calibration purposes, a customised test rig was developed and monitoring software was created in the LabVIEW environment, to record the temperature and resistance signals simultaneously. TSF samples were tested in various thermal environments, under laboratory conditions and in practical wear trials, to analyse the relationship between the temperature and resistance of the sensing fabric and to develop base line specifications such as sensitivity, resistance ratio, precision, nominal resistance, and response time; the influence of external parameters such as humidity and strain were also monitored. The regression uncertainty was found to be less than in ±0.1°C; the repeatability uncertainty was found to be less than ±0.5°C; the manufacturing uncertainty in terms of nominal resistance was found to be ± 2% from its mean. The experimental T-R relationship of TSF was validated by modelling in the thermo-electrical domain in both steady and transient states. A maximum error of 0.2°C was found between the experimental and modelled T-R relationships. TSF samples made with bare wire sensing elements showed slight variations in their resistance during strain tests, however, samples made with insulated sensing elements did not demonstrate any detectable strain-dependent-resistance error. The overall thermal response of TSF was found to be affected by basal fabric thickness and mass; the effect of RH was not found to be significant. TSF samples with higher-resistance sensing elements performed better than lower-resistance types. Furthermore, TSF samples made using insulated wire were more straightforward to manufacture because of their increased tensile strength and exhibited better sensing performance than samples made with bare wire. In all the human body wear trials, under steady-state and dynamic conditions both sensors followed the same trends and exhibited similar movement artifacts. When layers of clothing were worn over the sensors, the difference between the response of the TSF and a high-precision reference temperature were reduced by the improved isothermal conditions near the measurement site.

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13

Wu, Tsunghsueh Shannon Curtis. „Surface plasmon assisted spectroscopies and their application in trace element analysis, the study of biomolecular interactions, and chemical sensing“. Auburn, Ala., 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Chemistry_and_Biochemistry/Dissertation/Wu_Tsung%20Hsueh_20.pdf.

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14

Zhang, Da. „On the Low Frequency Noise in Ion Sensing“. Doctoral thesis, Uppsala universitet, Fasta tillståndets elektronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-320544.

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Ion sensing represents a grand research challenge. It finds a vast variety of applications in, e.g., gas sensing for domestic gases and ion detection in electrolytes for chemical-biological-medical monitoring. Semiconductor genome sequencing exemplifies a revolutionary application of the latter. For such sensing applications, the signal mostly spans in the low frequency regime. Therefore, low-frequency noise (LFN) present in the same frequency domain places a limit on the minimum detectable variation of the sensing signal and constitutes a major research and development objective of ion sensing devices. This thesis focuses on understanding LFN in ion sensing based on both experimental and theoretical studies. The thesis starts with demonstrating a novel device concept, i.e., ion-gated bipolar amplifier (IGBA), aiming at boosting the signal for mitigating the interference by external noise. An IGBA device consists of a modified ion-sensitive field-effect transistors (ISFET) intimately integrated with a bipolar junction transistor as the internal current amplifier with an achieved internal amplification of 70. The efficacy of IGBA in suppressing the external interference is clearly demonstrated by comparing its noise performance to that of the ISFET counterpart. Among the various noise sources of an ISFET, the solid/liquid interfacial noise is poorly studied. A differential microelectrode cell is developed for characterizing this noise component by employing potentiometry and electrochemical impedance spectroscopy. With the cell, the measured noise of the TiN/electrolyte interface is found to be of thermal nature. The interfacial noise is further found to be comparable or larger than that of the state-of-the-art MOSFETs. Therefore, its influence cannot be overlooked for design of future ion sensors. To understand the solid/liquid interfacial noise, an electrochemical impedance model is developed based on the dynamic site-binding reactions of surface hydrogen ions with surface OH groups. The model incorporates both thermodynamic and kinetic properties of the binding reactions. By considering the distributed nature of the reaction energy barriers, the model can interpret the interfacial impedance with a constant-phase-element behavior. Since the model directly correlates the interfacial noise to the properties of the sensing surface, the dependencies of noise on the reaction rate constants and binding site density are systematically investigated.

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15

Altaf, Kazim. „Investigation of the effect of relative humidity on additive manufactured polymers by depth sensing indentation“. Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8567.

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Additive manufacturing methods have been developed from rapid prototyping techniques and are now being considered as alternatives to conventional techniques of manufacturing. Stereolithography is one of the main additive methods and is considered highly accurate and consistent. Polymers are used as stereolithography materials and exhibit features such as high strength-to-weight ratio, corrosion resistance, ease of manufacturing and good thermal and electrical resistance properties. However, they are sensitive to environmental factors such as temperature, moisture and UV light, with moisture being identified as one of the most important factors that affect their properties. Moisture generally has an adverse effect on the mechanical properties of polymers. Investigation of the effects of moisture on polymers can be carried out using a number of experimental techniques; however, the benefits of the depth sensing indentation method over bulk tests include its ability to characterise various mechanical properties in a single test from only a small volume of material and the investigation of spatial variation in mechanical properties near the surface. The aim of this research was to investigate the effects of varying relative humidity on the indentation behaviour of stereolithography polymers and to develop a modelling methodology that can predict this behaviour under various humidities. It was achieved by a combination of experimental and numerical methods. Depth sensing indentation experiments were carried out at 33.5 %, 53.8 %, 75.3 % and 84.5 % RH (relative humidity) and 22.5 °C temperature to investigate the effects of varying humidity on the micron scale properties of the stereolithography resin, Accura 60. In order to minimise the effects of creep on the calculated properties, appropriate loading and unloading rates with suitable dwell period were selected and indentation data was analysed using the Oliver and Pharr method (1992). A humidity control unit fitted to the machine was used to condition the samples and regulate humidity during testing. Samples were also preconditioned at 33.5 %, 53.8 %, 75.3 % and 84.5 % RH using saturated salt solutions and were tested at 33.5 % RH using humidity control unit. It was seen that properties such as indentation depth increased and contact iv hardness and contact modulus decreased with increasing RH. The samples conditioned and tested using the humidity control unit at high RH showed a greater effect of moisture than the preconditioned samples tested at 33.5 % RH. This was because the samples preconditioned at high RH exhibited surface desorption of moisture when tested at ambient RH, resulting in some recovery of the mechanical properties. In order to investigate these further, tests were performed periodically on saturated samples after drying. Ten days drying of samples conditioned for five days at 84.5 % RH provided significant, though not complete, recovery in the mechanical properties. These tests confirmed that Accura 60 is highly hygroscopic and its mechanical properties are a function of RH and removal of moisture leads to a significant recovery of the original mechanical properties.

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Sankaranarayanan, Subramanian K. R. S. „Design of surface acoustic wave sensors with nanomaterial sensing layers : application to chemical and biosensing“. [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002245.

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17

Ulianova, V. O., A. T. Orlov und O. V. Bogdan. „Formation of ZnO Nanostructured Thin Film by Hydrothermal Method“. Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35191.

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Formation of zinc oxide nanostructured thin films at different temperatures on Al-coated silicon and lithium niobate substrates by hydrothermal method was presented. The comparison of morphology of nanostructured thin films formed by hydrothermal and electrodeposition method was carried out. The opportunity to use the hydrothermal method instead electrodeposition to obtain nanostructured films on a conductive layer was shown. The dependence of morphology and crystallinity from growth temperature was established using scanning electron microscopy and X-ray diffractometry. The application of synthesized films as sensing layer of acoustic wave based and electrochemical sensors could enhance its sensitivity to pollutants in gas or liquid phases by an active area increasing. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35191

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Marsh, Oliver John. „Ice dynamics and mass balance in the grounding zone of outlet glaciers in the Transantarctic Mountains“. Thesis, University of Canterbury. Gateway Antarctica, 2013. http://hdl.handle.net/10092/8722.

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The Antarctic grounding zone has a disproportionately large effect on glacier dynamics and ice sheet stability relative to its size but remains poorly characterised across much of the continent. Accurate ice velocity and thickness information is needed in the grounding zone to determine glacier outflow and establish to what extent changing ocean and atmospheric conditions are affecting the mass balance of individual glacier catchments. This thesis describes new satellite remote sensing techniques for measuring ice velocity and ice thickness, validated using ground measurements collected on the Beardmore, Skelton and Darwin Glaciers and applied to other Transantarctic Mountain outlet glaciers to determine ice discharge. Outlet glaciers in the Transantarctic Mountains provide an important link between the East and West Antarctic Ice Sheets but remain inadequately studied. While long-term velocities in this region are shown here to be stable, instantaneous velocities are sensitive to stresses induced by ocean tides, with fluctuations of up to 50% of the mean observed in GPS measurements. The potential error induced in averaged satellite velocity measurements due to these effects is shown to be resolvable above background noise in the grounding zone but to decrease rapidly upstream. Using a new inverse finite-element modelling approach based on regularization of the elastic-plate bending equations, tidal flexure information from differential InSAR is used to calculate ice stiffness and infer thickness in the grounding zone. This technique is shown to be successful at reproducing the thickness distribution for the Beardmore Glacier, eliminating current issues in the calculation of thickness from freeboard close to the grounding line where ice is not in hydrostatic equilibrium. Modelled thickness agrees to within 10% of ground penetrating radar measurements. Calibrated freeboard measurements and tide-free velocities in the grounding zones of glaciers in the western Ross Sea are used to calculate grounding zone basal melt rates, with values between 1.4 and 11.8 m/a⁻¹ in this region. While strongly dependent on grounding line ice thickness and velocity, melt rates show no latitudinal trend between glaciers, although detailed error analysis highlights the need for much improved estimates of firn density distribution in regions of variable accumulation such as the Transantarctic Mountains.

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Priščák, Juraj. „Charakterizace senzitivních nanomateriálů pro MOX senzory plynů“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442521.

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This thesis deals with one-dimensional (1D) and two-dimensional nanomaterials (2D) in terms of their utilization for new types of gas sensors. Thesis focuses on study of sensing elements for gas sensors based on semiconductor metal oxide materials (MOX) and their manufacturing technology. The objective of the thesis is the design and implementation of a sensing elements formed by selected nanomaterials based on the structure of interdigital electrodes. The result of the practical part of the thesis is the characterization and comparison of materials in terms of their detection parameters in the presence of selected test gases. The first part of thesis hierarchically defines chemoresistive gas sensor, characterizes and explains its operation principle. Second part studies 1D and 2D nanomaterials of sensing elements for MOX chemoresistive gas sensors, contains a research of their properties and describes their methods of manufacturing and implementation. The last part deals with the implementation of the sensitive layer of the sensor with selected nanomaterials, characterizes and compares their detection properties.

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20

Smola, Tomáš. „Analýza konstrukčních uzlů diskového podmítače“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-444895.

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The aim of this diploma thesis is to analyse loading forces which impact on the frame of the disk plough-harrow during the real operation, suggestion and assembling of the measuring system for measuring of real loading. On the basis of this measuring to accomplish structural deformational tensor analysis of the frames load-bearing’s machine. In the introduction is shortly described using of the disk plough-harrow in modern agriculture. The diploma thesis is divided into two parts. The first part is devoted to the suggestion of the measuring system and loading measuring under real working conditions. The second part is focused on deformational tensor analysis of the frames load-bearing’s machine through the method of final elements. In conclusion it follows the evaluation of gained pieces of knowledge.

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21

Chambon, Hugo. „Simulation and characterization of multi-layered surface acoustic wave devices for filtering and sensing applications“. Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2512.

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Cette thèse porte sur la conception et la caractérisation de micro-dispositifs à ondes acoustiques multicouches. La cinquième génération de communication (5G) nécessite des résonateurs acoustiques plus performants (fréquences > 3GHz, bande passante plus large). Dans ce contexte, nous avons conçu et optimisé par simulation FEM la géométrie de résonateurs à ondes de Lamb à base d’AlScN. Le dispositif final, constitué d’une couche composée de 30% de Sc et déposée sur un miroir de Bragg W/SiO2, montre d’excellentes performances (coefficient de couplage de 5% et facteur de qualité de 768) et un bon accord avec la simulation. Pour caractériser la surface de BAW et SAW sur la gamme de fréquence 5G, nous avons également conçu et développé un interféromètre hétérodyne. Ce dernier a été utilisé avec succès pour caractériser des vibrations de surface d'une amplitude comprise entre 1 et 10 pm à 5,95 GHz. Par ailleurs, grâce à leur robustesse et leur capacité à être interrogé sans-fil, les capteurs SAW sont utilisés dans des environnements difficiles et suscitent un grand intérêt pour les applications médicales et de contrôle de santé intégré. Récemment, l’introduction d’empilements multi-matériaux offre de nouvelles opportunités de développements. Nous avons ainsi étudié un capteur de pression composé de deux couches complémentaires, ainsi qu'un capteur dit package-less utilisant des couches d’impédances acoustiques différentes. Pour concevoir ces nouveaux capteurs, nous avons développé un outil de simulation reposant sur l'extraction de paramètres de couplage de modes et tenant compte des effets de la température, des contraintes et des déformations pour estimer leur sensibilité
This thesis deals with the design and characterization of multilayer acoustic wave micro-devices. The fifth generation of communication (5G) requires more efficient acoustic resonators (frequencies > 3GHz, wider bandwidth). In this context, we have designed and optimized using FEM simulation, the geometry of Lamb wave resonator based on AlScN. The final device, consisting of a layer composed of 30% Sc and deposited on a Bragg W/SiO2 mirror, shows excellent performance (coupling coefficient of 5% and quality factor of 768) as well as a good agreement with the simulation. To characterize the surface of BAW and SAW over the 5G frequency range, we also designed and developed a heterodyne interferometer. The latter has been used successfully to characterize surface vibrations with amplitudes between 1 and 10 pm at 5.95 GHz. Furthermore, thanks to their robustness and ability to be wirelessly interrogated,SAW sensors are used in harsh environments and are of great interest for medical applications and structural health monitoring. Recently, the introduction of multi-material stacks offers new development opportunities. We thus studied a pressure sensor composed of two complementary layers, as well as a so-called package- less sensor using different acoustic impedance layers. To design these new sensors, we have developed a simulation tool based on the extraction of mode coupling parameters and taking into account the effects of temperature, stresses and strains to estimate their sensitivity

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Nixdorf, Erik. „Combining measurements, remote sensing and numerical modelling to assess multi-scale flow dynamics in groundwater-dependent environmental systems“. Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-236485.

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Groundwater flow modelling provides an important quantitative instrument for addressing issues related to the quantity and quality of groundwater and the connected water resources. Consequently, groundwater flow models have been developed and used ubiquitously in science to deepen the understanding of subsurface processes and their drivers as well as management and planning tools. The present work investigates how numerical models can be linked to field investigations and public databases to quantitatively approach questions in the area of groundwater research. The primary goal is to develop new, efficient ways to overcome limitations of the individual hydrological concepts for solving specific hydrological problems and to increase the understanding of practical applicability of different methods. For this purpose, tailor-made approaches were developed for different study areas covering diverse spatial scales: the hydrology of a small mining lake, the riparian aquifer at the scale of a single meander as well as the aquifer systems of a large-scale river basin in China. The first part of the work deals with the physical and mathematical modelling of water constituents balance in a meromictic mining lake in Lusatia. The capability of using a rather simple mass-balance model based on a sufficient dataset of field data to evaluate lake stratification and lake-groundwater interaction were shown. In the second part, a transient numerical groundwater flow model was developed for the riparian aquifer of a stream meander and was calibrated by three different salt tracer tests. The model was used to proof the reliability of subsurface travel times derived from time series analysis and to give insights in the riparian zone dynamics during changing hydraulic gradients. The third part of the work describes the methodology to conduct risk assessment of groundwater contamination on the large catchment scale of the Songhua River in China. A comprehensive literature study was conducted to get an overview about measurement data on water quality data in China. A three-dimensional numerical flow and mass transport model was applied to access the flow and matter transport dynamics in the aquifer system of a sub-basin considering changing groundwater exploitation scenarios. Consequently, numerical groundwater modelling was combined with processed remote sensing and web mapping service data to overcome field data limitations and to derive groundwater vulnerability, groundwater hazard and groundwater risk maps for the entire Songhua River Basin. Summarizing, this doctoral thesis could develop new methods of combining field measurements, data assimilation and aggregation from various sources and groundwater modelling strategies and successfully apply these methods to find solutions on problems of multiple scales and across water systems
Die Grundwassermodellierung stellt eine wichtige wissenschaftliche Methode zur quantitativen Analyse von Fragestellungen zum Schutz der Menge und Güte der Grundwasserressourcen sowie der angeschlossenen Wasserkörper dar. Dementsprechend werden Grundwassermodelle sowohl für Planungs- und Bewertungszwecke im Wasserressourcenmanagement als auch zur wissenschaftlichen Erforschung der Prozesse im Untergrund entwickelt und angewendet. Die vorliegende Arbeit untersucht in diesem Rahmen, wie numerische Modelle, Feldmessungen und Daten generiert aus Fernerkundungsdaten und Webplattformen systematisch verknüpft werden können, um Fragestellungen im Bereich der Grundwasserforschung quantitativ zu beantworten. Das Ziel der Arbeit ist es neue effiziente Abläufe zu entwickeln, die die Limitierung der einzelnen Methoden überwinden und diese auf deren Anwendbarkeit für die Lösung spezifischer hydrologischer Probleme zu analysieren. Zu diesem Zweck wurden in dieser Doktorarbeit fallspezifische Lösungen für verschiedene Untersuchungsgebiete entwickelt, die sowohl in der räumlichen Skale als auch in den zu untersuchenden hydrologischen Fragestellungen eine große Diversität aufweisen. Im ersten Teil der Arbeit wurde die Massenbilanz von Wasserinhaltsstoffen in einem meromiktischen Tagebaurestsee im Lausitzer Revier durch physikalische und mathematische Modellierungsmethoden untersucht. Dabei konnte gezeigt werden, dass auf Basis einer gewonnenen mehrjährigen Zeitreihe von Messdaten ein einfaches Massenbilanzmodell in der Lage ist, sowohl Seeschichtungs- als auch Grundwasseraustauschdynamiken quantitativ zu beschreiben. Der zweite Teil der Arbeit umfasst die Entwicklung eines transienten numerischen Grundwassermodells für den quartären Uferaquifer im Bereich eines Flussmäanders der Selke welches anhand von Daten aus mehreren Salztracertests kalibriert wurde. Das Modell wurde dafür verwendet die transienten Verweilzeiten in der gesättigten Zone des Mäanderbogens unter dem Einfluss dynamischer hydraulischer Bedingungen zu untersuchen. Die Ergebnisse wurden im Anschluss mit Verweilzeiten verglichen, die aus der Analyse der zeitlichen Verschiebung von gemessenen elektrischen Leitfähigkeitszeitreihen zwischen Fluss und Grundwassermessstellen gewonnen wurden. Durch dieses kombinierte Verfahren konnten sowohl die Beschränkungen der zeitreihenbasierten Verweilzeitberechnung aufgezeigt als auch ein tieferes Systemverständnis für die Interaktionsdynamiken zwischen Grund- und Flusswasser auf der Mäanderskala gewonnen werden. Der dritte Teil der Arbeit beschreibt die Vorgehensweise für die Bewertung des Grundwasserkontaminationsrisikos im Einzugsgebiet des Songhua Flusses in China. Eine umfassende Literaturstudie wurde durchgeführt, um einen Überblick über die Verfügbarkeit von Messdaten zur Belastung der Wasserressourcen Chinas mit organischen Schadstoffen zu erhalten. Danach wurde für ein Teileinzugsgebiet ein dreidimensionales numerisches Grundwassermodell auf Basis der vorhandenen hydrogeologischen Daten aufgebaut. Dieses wurde dazu verwendet die Änderungen im Stofftransports und den Schadstoffkonzentrationen innerhalb des Aquifersystems unter steigenden Entnahmeraten zu analysieren. Basierend auf diesen Studien wurden auf der Skale des Gesamteinzugsgebiets, um die beschränkte Verfügbarkeit von Felddaten auszugleichen, die Ergebnisse der numerischen Grundwassermodellierung mit Fernerkundungsdaten und Webdatenbanken in einem Indexsystem kombiniert mit dem für die oberflächennahen Aquifere Vulnerabilität, Gefährdungspotential und Verschmutzungsrisiko in einer räumlichen Auflösung von 1 km² bestimmt wurden. Zusammenfassend konnten durch die vorliegende Doktorarbeit neue passgenaue Methoden zur effektiven Kombination von in-situ Messungen, der Datenerhebung und Datenintegration aus vielfältigen Datenquellen sowie numerischen Grundwassermodellierungsstrategien entwickelt und zur Lösung der untersuchten hydrologischer Fragestellen auf den verschiedenen Skalen und über die Grenzen der einzelnen hydrologischen Teilsysteme hinaus erfolgreich angewandt werden

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Liu, Juan. „Electrochemical Characterizations and Theoretical Simulations of Transport Behaviors at Nanoscale Geometries and Interfaces“. Digital Archive @ GSU, 2012. http://digitalarchive.gsu.edu/chemistry_diss/74.

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Since single nanopores were firstly proposed as a potential rapid and low-cost tool for DNA sequencing in 1990s (PNAS, 1996, 93, 13770), extensive studies on both biological and synthetic nanopores and nanochannels have been reported. Nanochannel based stochastic sensing at single molecular level has been widely reported through the detection of transient ionic current changes induced by geometry blockage due to analytes translocation. Novel properties, including ion current rectification (ICR), memristive and memcapacitive behaviors were reported. These fundamental properties of nanochannels arise from the nanoscale dimensions and enables applications not only in single molecule sensing, but also in drug delivery, electrochemical energy conversion, concentration enrichment and separation, nanoprecipitation, nanoelectronics etc. Electrostatic interactions at nanometer-scale between the fixed surface charges and mobile charges in solution play major roles in those applications due to high surface to volume ratio. However, the knowledge of surface charge density (SCD) at nanometer scale is inaccessible within nanoconfinement and often extrapolated from bulk planar values. The determination of SCD at nanometer scale is urgently needed for the interpretation of aforementioned phenomena. This dissertation mainly focuses on the determination of SCD confined at a nanoscale device with known geometry via combined electroanalytical measurements and theoretical simulation. The measured currents through charged nanodevices are different for potentials with the same amplitude but opposite polarities, which deviates away from linear Ohm's behavior, known as ICR. Through theoretical simulation of experiments by solving Poisson and Nernst-Planck equations, the SCD within nanoconfinement is directly quantified for the first time. An exponential gradient SCD is introduced on the interior surface of a conical nanopre based on the gradient distribution of applied electric field. The physical origin is proposed based on the facilitated deprotonation of surface functional groups by the applied electric field. The two parameters that describe the non-uniform SCD distribution: maximum SCD and distribution length are determined by fitting high- and low-conductivity current respectively. The model is validated and applied successfully for quantification and prediction of mass transport behavior in different electrolyte solutions. Furthermore, because the surface charge distribution, the transport behaviors are intrinsicaly heterogeneous at nanometer scale, the concept is extended to noninvasively determine the surface modification efficacy of individual nanopore devices. Preliminary results of single molecule sensing based on streptavidin-iminobiotin are included. The pH dependent binding affinity of streptavidin-iminobiotin binding is confirmed by different current change signals ("steps" and "spikes") observed at different pHs. Qualitative concentration and potential dependence have been established. The chemically modified nanopores are demonstrated to be reusable through regenerating binding surface.

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Bonilla, Riaño Adriana 1980. „Film thickness measurement with high spatial and temporal resolution planar capacitive sensing in oil-water pipe flow = Medida da espessura de filme usando sensor capacitivo de alta resolução espacial e temporal para escoamentos óleo-água em tubos“. [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265764.

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Orientadores: Antonio Carlos Bannwart, Oscar Mauricio Hernandez Rodriguez
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências
Made available in DSpace on 2018-08-28T09:34:02Z (GMT). No. of bitstreams: 1 BonillaRiano_Adriana_D.pdf: 7155927 bytes, checksum: 63be57b0a5136f5e783cfb4f870b0189 (MD5) Previous issue date: 2015
Resumo: Neste trabalho, é apresentado o desenvolvimento de uma nova técnica para a medição da espessura do filme de água com alta resolução espacial e temporal em escoamento óleo-água. É proposto o uso de um sistema de medição de capacitância elétrica para medir filmes finos de água na proximidade da parede do tubo. O sistema conta com um sensor planar e foi necessário determinar a melhor geometria via simulações baseadas no Método de Elementos Finitos (FEM) para o caso de escoamento óleo-água. As características comparadas foram a profundidade de penetração do campo elétrico no filme de água, a sensibilidade, a resolução espacial mínima e a resposta quase-linear. Padrões de escoamento óleo-água disperso e anular instável foram estudados numa tubulação vertical de 12 m de comprimento, feita de vidro, com 50,8 milímetros de diâmetro interno. Os fluidos usados foram óleo mineral (com densidade 828 kg/m3 e viscosidade 220 mPas) e água da torneira. O trabalho experimental foi realizado nas instalações de escoamento multifásico do Laboratório de Engenharia Térmica e Fluidos (NETeF) da EESC-USP. Foi medida a espessura média do filme de água usando o sistema capacitivo e uma câmera de vídeo de alta velocidade. Para obter a espessura do filme de água a partir das imagens, foi proposto um algoritmo de pré-processamento e um algoritmo de segmentação que combina vários métodos disponíveis na literatura. Os resultados experimentais do sensor capacitivo mostraram que o sistema pode medir espessuras entre 400 µm e 2200 µm. O escoamento anular instável é caracterizado por grandes flutuações na no sentido do escoamento e na direção do perímetro, e estruturas interfaciais grandes (gotas). Por sua vez, o escoamento disperso tem flutuações menores no sentido do escoamento e na direção do perímetro, e estruturas interfaciais menores (gotículas). Uma estrutura interfacial média no espaço e no tempo é proposta para modelar a interface entre a região próxima à parede do tubo e a região do núcleo, e sua análise foi feita no domínio do tempo e da frequência. Foram estudadas a amplitude, velocidade e o comprimento da estrutura interfacial em cada par transmissor-receptor do sensor. Foi possível estabelecer correlações para a velocidade das estruturas em escoamento de óleo em água
Abstract: The development of a new technique for high spatial and temporal resolution film thickness measurement in oil-water flow is presented. A capacitance measurement system is proposed to measure thin water films near to the wall pipe. A planar sensor was chosen for sensing and some geometries were compared using finite elements method (FEM). The penetration depth, the sensitivity, the minimum spatial resolution (high spatial resolution) and the quasi-linear curve were the analyzed characteristics. Dispersed and unstable-annular oil-water flows patterns were studied in a 12-m long vertical glass pipe, with 50.8 mm of internal diameter, using mineral oil (828 kg/m3 of density and 220 mPa s of viscosity) and tap water. The experimental work was carried out in the multiphase-flow facilities of The Thermal-Fluids Engineering Laboratory (NETeF) of EESC-USP. Experiments with a high-speed video camera and the proposed capacitance system were performed to obtain images of the oil-water flow near the pipe wall. A pre-processing enhancement algorithm and a combined segmentation algorithm are proposed and allowed the measurement of characteristic space and time averaged water film thickness. Experimental results of the capacitive technique showed that the system could measure thickness between 400 µm and 2200 µm. It was possible to recognize and characterize typical behaviors of the two different flow patterns studied. Unstable-annular flow can be described by huge fluctuations on the flow direction and perimeter direction, and big interfacial structures (drops). On the other hand, dispersed flow has tiny fluctuations on the flow direction and perimeter direction, and smaller interfacial structures (droplets). An interfacial structure is suggested in order to model the interface between wall and core regions and it was analyzed in time and frequency domains; amplitude, velocity and wavelength at each pair transmitter-receiver of the sensor were studied. Correlations for the interfacial structure velocity were found for dispersed oil-in-water flow and unstable-annular flow
Doutorado
Explotação
Doutora em Ciências e Engenharia de Petróleo
CAPES

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Seoudi, Tarek. „Non-intrusive CdSe-based quantum dots for sensing pressure and temperature in lubricated contacts“. Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI009.

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Cette thèse est dédiée à la mesure des pressions et des températures locales et à la comparaison de la génération de chaleur dans les contacts élastohydrodynamiques (EHD) de type tout acier et hybride (nitrure de silicium-acier). Le but ultime de ce travail est de développer une nouvelle technique in situ non-intrusive, exploitant la sensibilité de la photoluminescence (PL) des boîtes quantiques (QDs) de CdSe/CdS/ZnS aux variations de pression et température, afin de cartographier ces deux paramètres dans les contacts EHD. Dispersible à faible concentration dans les lubrifiants, il est montré que les QDs ne modifient pas le comportement rhéologique du fluide porteur et que le cisaillement n’est pas perturbateur à la réponse en PL. La calibration des QDs en suspension confirme la dépendance de la réponse en PL des QDs à la pression et à la température. Les mesures in situ sont effectuées en utilisant un banc d’essai bille-disque. La comparaison entre les mesures in situ de pression et de température et celles prédites à l'aide d'un modèle éléments finis TEHD interne montre une bonne concordance, ce qui démontre la faisabilité de la méthodologie proposée. Les effets du glissement et du chargement normal sur la pression, la température et la chaleur générée sont reportés. L’effet des propriétés thermiques des solides est souligné et la répartition de la chaleur générée entre les solides en contact est étudiée. L'équilibre énergétique entre l'énergie mécanique et l'énergie thermique interne générée par compression et cisaillement est démontré en comparant les pertes de puissance expérimentales et la chaleur générée issue du modèle numérique, pour des contacts acier-acier et hybrides
This thesis is dedicated to the measurement of local pressure and temperature and to compare the heat generation in all-steel and silicon nitride-steel (hybrid) elastohydrodynamic (EHD) contacts. The ultimate goal of this work is to develop a new non-intrusive in situ technique, exploiting the sensitivity of the photoluminescence (PL) of CdSe/CdS/ZnS quantum dots (QDs) to pressure and temperature. Dispersible in small concentration in lubricants, it is shown that the QDs doesn’t modify the rheological behavior of the carrier fluid and that shearing is not perturbative to the QDs PL response. The calibration of QDs in the suspension confirms the QDs PL dependence on temperature and pressure. The in situ measurements were conducted in EHD contacts using a ball-on-disc test rig. Comparisons between pressure and temperature measurements and predictions, using an in–house finite element thermal EHD model, showed a good agreement which demonstrates the feasibility of the proposed methodology. The effects of sliding and normal loading on pressure, temperature and heat generation are indicated. The effect of the thermal properties of the solid materials is underlined and the partition of the generated heat between the contacting solids is investigated. The energy equilibrium between the mechanical energy and the internal thermal energy generated by compression and shearing is demonstrated by comparing experimental power losses and numerical heat generation, in steel-steel and hybrid contacts

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Johnson, Andrea. „Sol-gel encapsulation of heterocyclic ligands for aqueous sensing applications“. Thesis, Brunel University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307510.

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Barth, Michael. „Hybrid nanophotonic elements and sensing devices based on photonic crystal structures“. Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2010. http://dx.doi.org/10.18452/16155.

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Die vorliegende Forschungsarbeit widmet sich der Entwicklung und Untersuchung neuartiger photonischer Kristallstrukuren für Anwendungen in den Gebieten der Nanophotonik und Optofluidik. Dabei konzentriert sich eine erste Serie von Experimenten auf die Charakterisierung und Optimierung photonischer Kristallresonatoren im sichtbaren Spektralbereich, wobei bisher unerreichte Resonatorgüten von bis zu 3400 gezeigt werden können. Diese Strukturen werden anschließend als Plattformen zur Herstellung von hybriden nanophotonischen Bauelementen verwendet, indem externe Partikel (wie z.B. Diamant-Nanokristalle und Metall-Nanopartikel) in kontrollierter Art und Weise an die Resonatoren gekoppelt werden. Zu diesem Zweck wird eine Nanomanipulationsmethode entwickelt, welche Rastersonden zur gezielten Positionierung und Anordnung von Partikeln auf den photonischen Kristallstrukturen benutzt. Verschiedene Arten solcher Hybridelemente werden realisiert und untersucht, einschließlich diamant-gekoppelter Resonatoren, plasmon-gekoppelter Resonatoren und Metall-Diamant Hybridstrukturen. Außer für Anwendungen auf dem Gebiet der Nanophotonik werden verschiedene photonische Kristallstrukturen auch hinsichtlich ihres Leistungsvermögens als biochemische Sensorelemente erforscht. Zum ersten Mal wird eine umfassende numerische Analyse der optischen Kräfte auf Objekte im Nahfeld photonischer Kristallresonatoren durchgeführt, welche neue Möglichkeiten zum Einfang sowie zur Detektion und Untersuchung biologischer Partikel in integrierten optofluidischen Bauteilen bieten. Weiterhin werden unterschiedliche photonische Kristallfasern bezüglich ihrer Detektionssensitivität in Absorptions- und Fluoreszenzmessungen untersucht, wobei sich eine klare Überlegenheit von selektiv befüllten Hohlkern-Designs im Vergleich zu Festkern-Fasern offenbart.
This thesis deals with the development and investigation of novel photonic crystal structures for applications in nanophotonics and optofluidics. Thereby, a first series of experiments focuses on the characterization and optimization of photonic crystal cavities in the visible wavelength range, demonstrating unprecedented cavity quality factors of up to 3400. These structures are subsequently employed as platforms for the creation of advanced hybrid nanophotonic elements by coupling external particles (such as diamond nanocrystals and metal nanoparticles) to the cavities in a well-controlled manner. For this purpose, a nanomanipulation method is developed, utilizing scanning probes for the deterministic positioning and assembly of particles on the photonic crystal structures. Various types of such hybrid elements are realized and investigated, including diamond-coupled cavities, plasmon-coupled cavities, and metal-diamond hybrid structures. Apart from applications in nanophotonics, different types of photonic crystal structures are also studied with regard to their performance as biochemical sensing elements. For the first time a thorough numerical analysis of the optical forces exerted on objects in the near-field of photonic crystal cavities is conducted, providing novel means to trap, detect, and investigate biological particles in integrated optofluidic devices. Furthermore, various types of photonic crystal fibers are studied with regard to their detection sensitivity in absorption and fluorescence measurements, revealing a clear superiority of selectively infiltrated hollow-core designs in comparison to solid-core fibers.

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Pant, Bhaskar. „Experimental nanomechanics of 1D nanostructures“. Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/41174.

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Nanotechnology offers great promise for the development of nanodevices. Hence it becomes important to study the mechanical behavior of nanostructures for their use in such systems. MEMS (Micro ElectroMechanical Systems) provide an effective and precise method for testing nanostructures. Consequently this study focuses on the development of a MEMS thermal nanotensile tester to investigate the mechanical behavior of one-dimensional nanostructures. Extensive characterization of these MEMS devices (structural, electrical and thermal behavior) was performed using experimental as well as finite element methods. Tensile testing of nanostructures requires manipulation of individual nanostructures on the MEMS device. The study involves the development of an efficient methodology for the manipulation of nanowires and nanobeams for nanoscale testing. Furthermore, two different sensing schemes for the developed devices, namely capacitive and resistive, have been extensively investigated and the advantages and various issues related to both have been discussed. Nanocrystalline (nc) Ni nanobeams (typical dimensions of 500 nm x 200 nm x 20 µm) have been tested to failure using the MEMS devices. Improvements in the design for the MEMS nanotensile tester have been suggested to significantly enhance the device performance and to resolve the various issues involved with nano scale tests. Differential capacitive sensing for stress-strain measurements has been suggested to improve the accuracy of strain measurements.

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D'Angelo, John Patrick. „Attenuation of Turbulent Boundary Layer Induced Interior Noise Using Integrated Smart Foam Elements“. Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/11252.

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Research presented herein involved the use of a smart skin treatment used for the attenuation of turbulent boundary layer induced interior noise. The treatment consisted of several Smart Foam actuators each having a reference and error sensor along with a feed forward, filtered-x controller. Studies were performed to determine if the use of multiple instances of single input, single output (SISO) control systems could be implemented with success given the difficulty of actively suppressing turbulent boundary layer induced interior noise. Further, this research will lead to the development of an integrated Smart Foam element consisting of a Smart Foam actuator, reference sensor, error sensor and SISO controller in one complete, stand--alone unit. Several topics were studied during this effort: reference sensing, error sensing, actuator design, controller causality, correlation of turbulent flow and resulting plate vibration, and coherence between plate vibration and the interior noise field. Each study was performed with the goal of improving the performance of active attenuation of turbulent boundary layer induced interior noise. Depending on the configuration of the control system, control was performed using either experiments or simulations based on experimental data. Within the desired control band of 400--800~Hz, attenuation of up to -3.1~dB$_A$ was achieved at the error sensors and up to -1.4~dB$_A$ within the observer plane relative to the uncontrolled case. However, over a band of greater coherence from 480--750~Hz, attenuation of up to -4.8~dB$_A$ was achieved at the error sensors and up to -2.6~dB$_A$ within the observer plane. Further, peak attenuation of up to -12~dB$_A$ was achieved within the observer plane. Studies were also conducted to increase the low frequency performance of the Smart Foam treatment. These experiments used tuning masses placed on the tops of the integrated Smart Foam elements to tune them to the fundamental mode of the vibrating plate. This treatment was used to reactively attenuate plate vibration such that the radiated acoustic field would be minimized. These experiments resulted in -6~dB$_A$ global attenuation at the plate fundamental resonance. Further, it was shown that the reactive treatment did not inhibit active control.
Ph. D.

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Clarke, Brandon William. „Development and Optimization of an Integrated Faraday Modulator and Compensator Design for Continuous Polarimetric Glucose Monitoring“. University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1364578141.

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Sebadduka, Jerome. „Mapping soil-landscape elements and the wetland in dambos and estimating CH4 and CO2 emissions from a dambo-terminated catena“. Thesis, Washington State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3640076.

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Dambos are seasonally saturated grassy valleys mainly found on the central African plateau. They are usually sub-divided into three catenary units - gleyed and frequently inundated bottoms, flat and rarely inundated floors, and sloping sandy margins - fringed at the interfluve by the well-drained uplands. Since dambos constitute ∼11% of Africa's arable land, soil information is required to guide sustainable use of the land. Further, it is important to determine the extent of the wetland environment in these landscapes so as to avoid miss-use of the land, which could arise because of varying definitions of the wetland in these landscapes. In addition, lack of knowledge about the true nature of dambo wetlands limits our understanding of their greenhouse gas (GHG) source and sinks strengths, which prevents projection of future GHG scenarios accompanying dambo use. This study was conducted so as to address these inadequacies, and is guided by the following specific objectives: (i) delineate dambo soil-landscape elements using aerial gamma-ray and terrain data; (ii) characterize a dambo wetland; and (iii) determine CH₄ and CO₂ sources and sinks in a dambo landscape.

The area Hansen et al. (2009) studied was revisited. For objective 1, their model training and validation data were used. For objectives 2 and 3, data (e.g., soil, water table and gas samples) were collected from experimental plots in the four landscape positions, geographically constrained around dambo bottom pixels. Data used were collected during the main (March to July 2008) and short rainfall (October and November 2009) seasons in the area.

An ANOVA analysis showed landscape position to have a proportionate influence on the variability of eU (46%), K% (28%) and eTh (27%); owing to the differences in soil properties along dambo cross-profiles. The results based on random forests (RF) and multinomial-ISODATA modeling, where gamma-ray and derivatives of a Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) were used to classify dambo catenary units, were accurate, but only slightly better than the method which made no use of gamma-ray (e.g., conditional inference tree) . It was concluded that dambo landscape elements can be mapped by using these two data sources; although terrain data provides more information. Based upon a combination of hydrology and soil properties, dambo bottoms were the only element shown to constitute the dambo wetland. This zone is inundated for at least three-quarters of the main rainfall season and soils are hydric. Using the landscape map created by Hansen et al. (2009), the wetland was found to constitute only ∼15% of the dambo. This is smaller than what was mapped by FAO-Africover and the Department of Survey and Mapping, Uganda (DSM). The wetland was also found to be the main source of CH₄ and sink of CO₂, with additional strengths attributed to the neighboring floor. Given that these constitute less than 20% of the landscape, dambo net contribution to the regional CH₄ budget is insignificant because 80% of the landscape is a sink. The worry, though, is the ongoing degradation, with the impact this has on the release of CO₂.

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Andrews, Emily Katherine 1975. „Elastic elements with embedded actuation and sensing for use in self-transforming robotic planetary explorers“. Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/88866.

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GAMA, ANTONIO LOPES. „MODELING OF PIEZOELECTRIC ELEMENTS FOR EXCITATION AND SENSING OF HIGH FREQUENCY ACOUSTIC SIGNALS IN COMPOSITE BEAMS“. PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1998. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26579@1.

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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O problema tratado nesta dissertação é o da modelagem da excitação, propagação e sensoriamento de ondas acústicas de alta frequência em compósitos piezoelétricos laminados. Empregou-se uma formulação de vigas baseada na teoria discreta de Reddy para compósitos laminados. Esta teoria tem como característica o emprego de funções de interpolação de ordem arbitrária para descrever a variação dos campos de deslocamento e do potencial elétrico ao longo da espessura do laminado. A utilização deste tipo de teoria possibilita a representação de campos de deslocamento que variam rapidamente ao longo da espessura, e que na faixa de altas frequências, são representativos daqueles associados com ondas guiadas em compósitos laminados. No domínio da frequência, o sistema de equações que descreve a resposta eletromecânica do laminado piezoelétrico é colocado na forma de uma equação de estado. A técnica de solução utilizada é baseada no método da imersão invariante, também conhecido como método da varredura ou método de Riccati. Para avaliar os limites da faixa de frequências onde diferentes aproximações são válidas, empregou-se uma técnica baseada na comparação entre o espectro de dispersão exato e aquele previsto pela teoria aproximada. Os resultados destas comparações, mostram que utilizando-se o número de funções de interpolação apropriado, a teoria discreta de Reddy é capaz de representar ondas de comprimento até quatro vezes menores que a espessura da viga. Na faixa de baixas frequências, os resultados são comparados com soluções numéricas fornecidas pelo método dos elementos finitos. Também são apresentados resultados que mostram a variação na resposta eletro-mecânica da viga quando descontinuidades são introduzidas nesta, bem como resultados de experimentos que envolvem a utilização de piezoelétricos como atuadores e sensores.
The proposed contribution adresses the problem of modeling high- frequency excitation, propagation, and sensing, of structural waves in composites containing piezoelectric sensors and actuators. The model for the active composite beam proposed here is based on Reddy’s discrete layerwise laminate theory. The displacement and electric potential are interpolated in the through-thickness direction using piecewise linear functions. In the frequency domain, the governing equations are written in a state space form. Comparisons between approximate and exact wave dispersion spectra are performed in order to assess the efficiency of the layerwise theory in a given frequency range. It is shown that by employing the proper interpolation, Reddy s theory is able to describe the dynamic response of the composite at frequencies where the associated wavelengths are of the same order or even shorter than the thickness of the piezoelectric layers. Next, the solution for the state space equation is obtained by employing an algorithm based on a discrete version of the Riccati transformation, It is shown that the algorithm is stable over a wide range of frequencies. In the low frequency range, the analytical results are compared with finite element results. Also are shown the change in the electrical and mechanical response when discontinuites are introduced in the beam, as well as basic experiments involving piezoelectric sensors and actuators.

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Powell, Alexander. „Engineering plasmonic light scattering with thin dielectric films : towards enhanced light trapping and novel sensing elements“. Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:c18025ef-a693-441d-bd88-e37ebc09b6a5.

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Plasmonic research is becoming increasingly focused on the integration of noble metal nanostructures with planar devices to enhance their performance. Whilst the physics of noble metal nanoparticles at a simple interface is well studied, their behaviour inside a thin film structure is not. This work investigates the effect that placement in a thin dielectric film has on the excited modes and the directional scattering from various geometries of nanoparticle; the focus is on the fundamental principles but the application of this work in light trapping and nanoantenna design is also discussed. Research is conducted using finite-difference time-domain simulations and a custom built dark-field Fourier-space microscope, designed to interrogate individual particles and measure their angular scattering in thin films for the first time. It is found that the excited modes, large angle scattering and substrate coupling of the nanoparticles can be manipulated and improved considerably through careful choice of the materials and dimensions of the layers. Scattering from silver nanowires into a substrate is observed experimentally for the first time and an overcoating thin film is exploited to create highly directional emission, which is compared with nanoantennas in the literature. The potential to use this system as a novel sensing element is discussed. Following on from this, the nanocube patch antenna system is reviewed and its operation as a subwavelength plasmonic gas sensor is demonstrated for the first time to test for relative humidity using the Nafion polymer. This easily fabricable system shows superior sensitivities to other single-particle sensors across a range of humidities and simulations predict that by using sharper cubes and different deposition processes a further tripling of the recorded efficiency is achievable. The nanopatch structure can be readily adapted to detect a variety of other gases, and has the potential for integration into photonic circuitry.

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Michail, Konstantinos. „Optimised configuration of sensing elements for control and fault tolerance applied to an electro-magnetic suspension system“. Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/5806.

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New technological advances and the requirements to increasingly abide by new safety laws in engineering design projects highly affects industrial products in areas such as automotive, aerospace and railway industries. The necessity arises to design reduced-cost hi-tech products with minimal complexity, optimal performance, effective parameter robustness properties, and high reliability with fault tolerance. In this context the control system design plays an important role and the impact is crucial relative to the level of cost efficiency of a product. Measurement of required information for the operation of the design control system in any product is a vital issue, and in such cases a number of sensors can be available to select from in order to achieve the desired system properties. However, for a complex engineering system a manual procedure to select the best sensor set subject to the desired system properties can be very complicated, time consuming or even impossible to achieve. This is more evident in the case of large number of sensors and the requirement to comply with optimum performance. The thesis describes a comprehensive study of sensor selection for control and fault tolerance with the particular application of an ElectroMagnetic Levitation system (being an unstable, nonlinear, safety-critical system with non-trivial control performance requirements). The particular aim of the presented work is to identify effective sensor selection frameworks subject to given system properties for controlling (with a level of fault tolerance) the MagLev suspension system. A particular objective of the work is to identify the minimum possible sensors that can be used to cover multiple sensor faults, while maintaining optimum performance with the remaining sensors. The tools employed combine modern control strategies and multiobjective constraint optimisation (for tuning purposes) methods. An important part of the work is the design and construction of a 25kg MagLev suspension to be used for experimental verification of the proposed sensor selection frameworks.

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Polidorio, Airton Marco. „Detenção de elementos da paisagem urbana em imagens aéreas multiespectrais /“. Presidente Prudente : [s.n.], 2007. http://hdl.handle.net/11449/100265.

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Resumo: Atividades inerentes à Fotogrametria e ao Sensoriamento Remoto que utilizam dados extraídos de imagens aéreas estão em constante desenvolvimento, seja pela inserção de novas tecnologias relacionadas com a aquisição desses dados, seja pelo estabelecimento de novos conceitos e métodos que permitem computá-los, transformando-os em informação. Essa transformação, dados-informação, é feita por vários processos entre os quais, alguns foram automatizados e outros necessitam da supervisão e da interação com um operador humano para realizá-la. Um dos fatores que impede a completa automação desses processos é a falta de conhecimento contextual prévio sobre a natureza dos dados. A detecção e a discriminação de elementos específicos em dados de imageamento aéreo constituem uma forma de adquirir esse conhecimento contextual. Este trabalho aborda esse problema de detectar e discriminar elementos específicos em dados de imageamento aéreo de regiões urbanas, especificamente: sombras, vegetação verde, corpos d'água, rodovias pavimentadas e telhados de edificações, bem como discriminar a natureza da elevação desses elementos, de forma que seja possível inferir se determinado elemento tem elevação própria, ou se estáao nível da superfície do terreno.
Abstract: Inherent activities to Photogrammetryand Remote Sensingthat use data acquired byaerial images are in constant development, due the useful of new hardware to acquire such data, or due the establishment of new concepts and methods that allow computing those data, transforming them in information. That transformation, data-to-information, is done by several processes. Some of these processes were automated and others still need the supervision and the interaction with a human operator to accomplish that transformation. A factor that obstruct the complete automation those processes is the lackof previous context-knowledge about the nature of those data. The detection and the discrimination of specific elements in aerial imagingdata constitute a wayto acquire that context-knowledge. This work approaches the problem related with the automatic detection and discrimination of specific elements in aerial imagingdata of urban areas, specifically: shadows; green vegetation; water bodies, paved-roads and roofs buildings, besides determiningthe nature of the elevation of those elements, in order to allow infer if a specific element has own elevation, or it is been at the level of the terrain surface. In order, to detect those elements, this workproposes new metrics, designed as enhancements indexes, to treat the elements of interest.
Orientador: Nilton Nobuhiro Imai
Coorientador: Antonio Garcia Tommaselli
Banca: José Alberto Quintanilha
Banca: Flávio Bortolozzi
Banca: Maria de Lourdes Bueno Trindade Galo
Banca: Júlio Hasegawa
Doutor

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Pardo, Milcíades Heitor de Abreu. „ELEMENTOS PARTICIPATIVOS PARA UM PLANO DE GESTÃO AMBIENTAL DO CAMPO EXPERIMENTAL DA EMBRAPA ACRE“. Pontifícia Universidade Católica de Goiás, 2012. http://localhost:8080/tede/handle/tede/2912.

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For proper exploitation of natural resources, it is necessary, besides the use of tools that assist in the planning of environmental activities and detailed knowledge of the region, an accurate environmental perception of those who inhabit this environment. Therefore, the aim of this paper is to propose a methodology for environmental management that helps in the understanding of processes related to conservation of natural resources with emphasis on its employees and neighboring communities. The study was carried out at Embrapa Acre with the use of direct and indirect research techniques (questionnaires), and also tools necessary for the utility of a geographic information system (GIS). To enhance the environmental perception of the communities involved two kinds of questionnaires were applied with closed and choice multiple questions. These were applied in the employees and neighboring communities levels, which resulted in a better understanding of the existing potentiality for development and the socioeconomic factors of the locality. We observed evident possibilities for the increase of the use of natural resources in the experimental field. The questionnaire results pointed and suggested practical unit developments, such as the reforestation of permanent preservation areas. These facts were corroborated by studies in the evaluation of field data collected and integrated in remote sensing. We highlighted the photointerpretation and as a result the suggestion of the adoption of a GIS by the company. Besides the theoretical emphasis, the compatibility between the use of aerial photographs and data mining was supported by softwares such as ArcGIS and made it possible the development of a database, which included the creation and development of spatial structures recognized and measured in field with the use of geographic position system (GPS). Thus, by means of experimental results obtained, the method of photointerpretation presented effective classification of the experimental field of Embrapa Acre, with elaboration of thematic maps of the area and a GIS. Allied to these techniques, the study infers the global perception of the community and employees as essential and confirms that environmental care has acquire more social and ecological sensitivity, in search of a better quality of life and sustainable development.
Para a exploração adequada dos recursos naturais é necessário, além da utilização de ferramentas que auxiliem no planejamento das atividades ambientais e do conhecimento detalhado da região, uma percepção ambiental apurada daqueles que habitam este meio. Portanto, o objetivo desse trabalho é propor uma metodologia de gestão ambiental que auxilie na compreensão dos processos relacionados à conservação dos recursos naturais, com ênfase em seus colaboradores e comunidades vizinhas. O estudo foi desenvolvido no campo experimental da Embrapa Acre com utilização de técnicas de pesquisa direta e indireta (questionários), além de ferramentas necessárias para utilização de um sistema de informação geográfica (SIG). Para acrescer a percepção ambiental das comunidades envolvidas, foram aplicados dois modelos de questionários com perguntas fechadas e de múltiplas escolhas. Estes foram aplicados nos níveis de colaboradores e das comunidades vizinhas, o que resultou uma melhor compreensão das potencialidades existentes de desenvolvimento e os fatores socioeconômicos da localidade. Observaram-se evidentes possibilidades de aumento do uso dos recursos naturais do campo experimental, como, por exemplo, o reflorestamento de áreas de preservação permanente. Este último, apoiado pelo estudo na avaliação dos dados de campo coletados e integrados no sensoriamento remoto. Destacou-se a fotointerpretação e, como resultado, a sugestão de adoção pela Empresa de um SIG. Além da ênfase teórica a compatibilidade entre o uso de fotografias aéreas e a mineração de dados, apoiou-se em softwares como o ArcGIS e tornou-se possível a elaboração de uma base de dados, que contou com a criação e elaboração de estruturas espaciais reconhecidas e aferidas no campo com auxílio de GPS Global Positioning System . Assim, por meio dos resultados experimentais obtidos, o método da fotointerpretação apresentou efetividade de classificação do campo experimental da Embrapa Acre, com elaboração de mapas temáticos da área e um SIG. Aliado a essas técnicas o estudo infere a percepção global das comunidades e colaboradores como essencial e confirma que o cuidado ambiental adquiriu maior sensibilidade social e ecológica na busca de uma melhor qualidade de vida e desenvolvimento sustentável.

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Polidorio, Airton Marco [UNESP]. „Detenção de elementos da paisagem urbana em imagens aéreas multiespectrais“. Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/100265.

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Atividades inerentes à Fotogrametria e ao Sensoriamento Remoto que utilizam dados extraídos de imagens aéreas estão em constante desenvolvimento, seja pela inserção de novas tecnologias relacionadas com a aquisição desses dados, seja pelo estabelecimento de novos conceitos e métodos que permitem computá-los, transformando-os em informação. Essa transformação, dados-informação, é feita por vários processos entre os quais, alguns foram automatizados e outros necessitam da supervisão e da interação com um operador humano para realizá-la. Um dos fatores que impede a completa automação desses processos é a falta de conhecimento contextual prévio sobre a natureza dos dados. A detecção e a discriminação de elementos específicos em dados de imageamento aéreo constituem uma forma de adquirir esse conhecimento contextual. Este trabalho aborda esse problema de detectar e discriminar elementos específicos em dados de imageamento aéreo de regiões urbanas, especificamente: sombras, vegetação verde, corpos d'água, rodovias pavimentadas e telhados de edificações, bem como discriminar a natureza da elevação desses elementos, de forma que seja possível inferir se determinado elemento tem elevação própria, ou se estáao nível da superfície do terreno.
Inherent activities to Photogrammetryand Remote Sensingthat use data acquired byaerial images are in constant development, due the useful of new hardware to acquire such data, or due the establishment of new concepts and methods that allow computing those data, transforming them in information. That transformation, data-to-information, is done by several processes. Some of these processes were automated and others still need the supervision and the interaction with a human operator to accomplish that transformation. A factor that obstruct the complete automation those processes is the lackof previous context-knowledge about the nature of those data. The detection and the discrimination of specific elements in aerial imagingdata constitute a wayto acquire that context-knowledge. This work approaches the problem related with the automatic detection and discrimination of specific elements in aerial imagingdata of urban areas, specifically: shadows; green vegetation; water bodies, paved-roads and roofs buildings, besides determiningthe nature of the elevation of those elements, in order to allow infer if a specific element has own elevation, or it is been at the level of the terrain surface. In order, to detect those elements, this workproposes new metrics, designed as enhancements indexes, to treat the elements of interest.

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Mangora, Andrea. „Simulazioni elettromagnetiche agli elementi finiti per un sensore di corrente integrato in tecnologia BCD“. Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14304/.

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L’obiettivo di questo elaborato è studiare la relazione che lega il campo magnetico alla corrente misurata in un sensore di corrente integrato basato sull’effetto Hall con lo scopo di poter realizzare una migliore progettazione del sensore stesso. Il circuito integrato oggetto di studio è in grado di effettuare misure di corrente a banda larga grazie all’innovativo design circuitale con cui è realizzata l’elettronica che governa la misura. Esso si basa su di un sensore a effetto Hall per misurare il campo magnetico generato dalla corrente che scorre su di una “strip” integrata, consentendo in questo modo un tasso di integrabilità elevato e la possibilità di effettuare la misura senza perdite. Di conseguenza, lo scopo di questo elaborato è l’analisi del campo magnetico generato da una strip metallica di dimensioni micrometriche e la sua relazione con i vari parametri di progetto. Per effettuare questo studio si è fatto ricorso ad un’analisi al calcolatore mediante software di simulazione fisica basato sul metodo degli elementi finiti, che consente la risoluzione di problemi fisici alle derivate parziali difficilmente trattabili per via analitica.

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Воробйов, Сергій Ігорович, Сергей Игоревич Воробьев und Serhii Ihorovych Vorobiov. „Вплив процесів фазоутворення на магнітні і магніторезистивні властивості приладових структур на основі Fe (Co) та Gd“. Thesis, СумДУ, 2015. http://essuir.sumdu.edu.ua/handle/123456789/39586.

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Дисертація присвячена встановленню загальних закономірностей у магнітних і магніторезистивних властивостях приладових структур на основі плівкових нанорозмірних систем із перехідних феромагнітних (Fe, Co) і рідкоземельного (Gd) металів та з’ясуванню впливу на них процесів фазоутворення й орієнтації зразка у зовнішньому магнітному полі. Установлено взаємозв’язок між особливостями структурно-фазового стану приладових структур у вигляді тришарових плівкових систем і мультишарів та їх магнітними й магніторезистивними властивостями. Показано, що при зміні товщини прошарку з ка-Gd залежність магнітоопору і коерцитивної сили має осцилюючий характер, який зникає при переході прошарку Gd у кристалічний стан. Утворення на інтерфейсах ферімагнітного твердого розчину (Fe (Со), Gd) призводить до істотних змін магнітних властивостей. Досліджено вплив орієнтації зразка у зовнішньому магнітному полі на величину магнітоопору, коерцитивної сили та намагніченості плівкових систем. Проведено розрахунок величини чутливості до магнітного поля та прямокутності петель гістерезису плівкових систем. Запропоновано можливі області використання плівкових систем на основі Fe (Co) і Gd.
Диссертация посвящена установлению общих закономерностей в магнитных и магниторезистивных свойствах приборных структур на основе пленочных наноразмерных систем с переходных ферромагнитных (Fe, Co) и редкоземельного (Gd) металлов и выяснения влияния на них процессов фазообразования и ориентации образца во внешнем магнитном поле. Установлена взаимосвязь между особенностями структурно-фазового состояния приборных структур в виде трехслойных пленочных систем и мультислоев с их магнитными и магниторезистивными свойствами. Показано, что в трехслойных пленках Fe (Co)/Gd/Fe (Co) в случае, когда слой с Gd находится в кристаллическом состоянии, происходят послойное перемагничивание и рост величины коэрцитивной силы относительно пленок, в которых слой с Gd находится в квазиаморфном состоянии. В мультислоях [Co/Gd] при увеличении количества фрагментов происходит рост величины коэрцитивной силы, а также остаточной намагниченности и намагниченности насыщения за счет размытия интерфейсов и увеличения концентрации ферромагнитной компоненты, соответственно. Установлено, что при изменении толщины слоя с ка-Gd зависимость магнитосопротивления и коэрцитивной силы имеет осциллирующий характер, исчезающий при переходе слоя Gd в кристаллическое состояние. Увеличение количества повторений в мультислоях [Co/Gd] приводит к росту величины магнитосопротивления. Экспериментально показано, что термообработка во всех случаях приводит к изменению магнитных и магниторезистивных свойств за счет изменения структурно-фазового состояния, а именно рекристаллизации, частичного окисления и диффузных процессов, в результате которых на интерфейсах образуется аморфный твердый раствор (Fe (Со), Gd) с ферримагнитним упорядочением, что приводит к исчезновению антиферромагнитного взаимодействия между слоями. Исследовано влияние ориентации образца во внешнем магнитном поле на величину магнитосопротивления, коэрцитивной силы и намагниченности пленочных систем. Проведен расчет величины чувствительности к магнитному полю и прямоугольности петель гистерезиса пленочных систем. Предложены возможные области использования пленочных систем на основе Fe (Co) и Gd.
The thesis is devoted to determination of general patterns in magnetic and magnetoresistive properties of device structures based on the nanoscale film systems of ferromagnetic transition (Fe, Co) and rare earth (Gd) metals and investigation of the influence on the processes of phase formation and orientation of the sample in an external magnetic field. The relationship between the peculiarities of structural and phase state of device structures in the form of three-layer film systems and multilayers and their magnetic and magnetoresistive properties are established. It is shown that by changing the thickness of the layer of the qa-Gd dependence of magnetoresistance and coercive force has oscillating character which transition layer of Gd disappears in the crystalline state. Formation on interfaces ferrimagnetic solid solution (Fe (Со), Gd) leads to significant changes of magnetic properties. The influence of the sample orientation in an external magnetic field on the value of the magnetoresistance, the coercive force and magnetization of film systems are investigated. The value of sensitivity to the magnetic field and the squareness of the hysteresis loops of film systems are calculated. The possible fields of application of the film systems based on Fe (Co) and Gd are proposed.

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Шутилєва, Ольга Вікторівна, Ольга Викторовна Шутилева und Olha Viktorivna Shutylieva. „Фазовий склад та магніторезистивні і магнітні властивості приладових структур на основі Ni і Со та Dy або Ві“. Thesis, Сумський державний університет, 2021. https://essuir.sumdu.edu.ua/handle/123456789/85453.

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Дисертаційна робота присвячена комплексному дослідженню впливу структурно-фазового стану на магнітні й магніторезистивні властивості приладових структур на основі плівкових систем із перехідних феромагнітних (Ni або Со) металів і рідкоземельного Dy або Ві та при різній орієнтації зразків у зовнішньому магнітному полі. Встановлено, що для всіх досліджуваних плівкових систем фіксується анізотропний характер магнітоопору за кімнатної температури вимірювання. Показано, що при зміні товщини прошарку з ка-Dy залежність магнітоопору і коерцитивної сили виявляє немонотонний характер, який зникає при переході у кристалічний стан. Дослідження магнітних властивостей показали, що після термообробки у тришарових плівках у більшості випадків відбувається зростання величини коерцитивної сили, намагніченості насичення та залишкової намагніченості. У тришарових плівках Со/Ві/Со у свіжосконденсованому стані коерцитивність не залежить від товщини прошарку з Ві, після відпалювання до 680 К її значення зростає зі збільшенням ефективної товщини Ві. Показано можливість практичного використання результатів дослідження для розробки функціональних елементів індукційних датчиків положення, анізотропних магніторезистивних датчиків положення і кута повороту, магнітного середовища запису інформації, що будуть мати стабільні робочі характеристики в широкому діапазоні температур.
Диссертация посвящена комплексному исследованию влияния структурно-фазового состояния на магнитные и магниторезистивные свойства приборных структур на основе пленочных систем с переходных ферромагнитных (Ni или Со) металлов и редкоземельного Dy или Ві и при разной ориентации образцов во внешнем магнитном поле. Установлено, что для всех исследуемых пленочных систем фиксируется анизотропный характер магнетосопротивления при комнатной температуре измерения. Показано, что при изменении толщины слоя с ка-Dy зависимость магнитосопротивления и коэрцитивной силы проявляет немонотонный характер, который исчезает при переходе в кристаллическое состояние. Исследование магнитных свойств показали, что после термообработки в трехслойных пленках в большинстве случаев происходит увеличение величины коэрцитивной силы, намагниченности насыщения и остаточной намагниченности. В трехслойных пленках Со/Ві/Со в свежосконденсированом состоянии коэрцитивность не зависит от толщины слоя с Ві, после отжига до 680 К ее значение возрастает с увеличением эффективной толщины Ві. Показана возможность практического использования результатов исследования для разработки функциональных элементов индукционных датчиков положения, анизотропных магниторезистивных датчиков положения и угла поворота, магнитной среды записи информации, будут иметь стабильные рабочие характеристики в широком диапазоне температур.
The PhD thesis is devoted to a complex study of the influence of the structural-phase state on the magnetic and magnetoresistive properties of devices structure based on film systems of transition ferromagnetic (Ni or Co) metals and rare earth Dy or Bi and to establish the influence of sample orientation in an external magnetic field. The interconnection between the features of the structural-phase state of the structures of devices in the form of three-layer film systems and their magnetic and magnetoresistive properties has been established. The phase composition of three-layer films based on Co and Bi in the as-deposited state corresponds to hcp-Co, fcc-Co, and rhombohedral-Bi. Three-layer films based on Ni or Co and Dy (dDy < 15 nm) before and after heat treatment, the phase composition is as follows: fcc-Ni + qa-Dy and hcp-Co + fcc-Co + qa-Dy. It is established that for all investigated film systems the anisotropic character of the magnetoresistance at room temperature of measurement is fixed. The maximum MR values for systems based on Ni or Co and Dy are observed in the perpendicular measurement geometry when Dy is in the quasi amorphous state. For a system based on Co and Bi, the maximum values are observed at its largest thicknesses in the system in the perpendicular geometry of the measurement. When the thickness of the layer changes from qa-Dy, the dependence of the magnetoresistance and coercive force reveals a nonmonotonic character, which disappears during the layer Dy transition to the crystalline state. Studies of magnetic properties have shown that after heat treatment in three-layer films in most cases there is an increase in the value of coercive force, saturation magnetization, and residual magnetization. In three-layer Co/Bi/Co films in an as-deposited state, the coercivity does not depend on the thickness of the Bi layer and after annealing to 680 K, its value increases with increasing effective Bi thickness. The possibility of practical use of research results for the development of functional elements of induction position sensors, anisotropic magnetoresistive position, and angle sensors, magnetic medium of information recording, which will have stable operating characteristics in a wide temperature range, is shown.

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Bonora, Chiara <1979&gt. „L'ambiente ed il paesaggio codificati. Principi comuni ed elementi distintivi ai sensi dei D.LGS. N. 152 del 2006 e D.LGS. N. 42 del 2004“. Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1312/.

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Brito, Patrícia Lustosa. „Sensoriamento remoto na identificação de elementos e tipologias urbanas relacionados à ocorrência da leptospirose no subúrbio ferroviário de Salvador, Bahia“. Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3138/tde-18082010-170309/.

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Em países em desenvolvimento, doenças infecciosas se constituem ainda um grave problema de saúde pública. Muitas vezes, essas doenças estão altamente relacionadas a condições urbanas que podem ser encontradas em áreas mais pobres. Nesses casos, o sensoriamento remoto (SR) pode ser utilizado como uma poderosa ferramenta de estudo. Novos produtos de SR se encontram disponíveis no mercado, permitindo o desenvolvimento de análises espaciais cada vez mais profundas e precisas. No entanto, a complexidade que envolve a epidemiologia de doenças, a irregularidade de ocupações urbanas e a heterogeneidade das imagens de alta resolução espacial têm restringido o desenvolvimento de estudos nesse campo científico. O desafio de identificar elementos e tipologias urbanas em imagens de sensoriamento remoto relacionadas à ocorrência da leptospirose justifica-se pela crença de que ferramentas de SR podem ser mais amplamente utilizadas no monitoramento de carências urbanísticas e, consequentemente, na gestão de ações e investimentos públicos. A metodologia contempla uma revisão bibliográfica sistemática, com base na qual foram criados modelos de transmissão da leptospirose e investigadas tipologias urbanas presentes na área de estudo. As variáveis baseadas em dados de SR que formam os indicadores dos modelos e que caracterizam as tipologias foram usadas para definir objetos e atributos, alvos das investigações em imagens de alta resolução espacial. Os procedimentos de SR adotados baseiam-se na segmentação multi-nível, classificação baseada em objeto, e utilizam ortofotografias aéreas, imagem QuickBird e base cartográfica do eixo viário do Subúrbio Ferroviário de Salvador. Para o cálculo das variáveis utilizou-se produtos do processamento da imagem QuickBird. Procedimentos de geoprocessamento foram realizados em sistema de informações geográficas. Por fim, realizaram-se as primeiras análises epidemiológicas que investigam a relação da leptospirose com os elementos e tipologias urbanas identificados por meio de SR, cujos resultados apontam maior influência do percentual de pavimentação das vias, sua largura e qualidade da edificação na possibilidade de ocorrência da leptospirose no Subúrbio. Possíveis fontes de viés são discutidas ao lado de propostas de continuação da pesquisa. Apesar dos problemas e limitações identificados no processo, o estudo mostra que a metodologia desenvolvida baseada em SR se constitui uma poderosa ferramenta de análise do espaço intra-urbano, uma vez que permite a identificação de elementos e tipologias relacionados a situações de risco, apoiando assim, o direcionamento de investimentos públicos que venham refletir na melhoria das condições de saúde da população.
In developing countries, infectious diseases are still a serious public health problem. These diseases are often and highly related to urban conditions found in poor areas, in these cases, remote sensing (RS) can be used as a powerful tool. New RS products are now available allowing the development of more complex and precise spatial analysis. On the other hand, the complexity of epidemiological studies, the lack of regularity of precarious urban settlements and the heterogeneity of high spatial resolution images have been restricting the development of studies in this areas. The challenge of identifying urban elements and typologies related to the leptospirosis using RS products is pursued due the belief that RS can be more used among professionals and researchers in the task of monitoring the urban environment, and directing public investments and actions. The methodology presented consists in a broad literature review, which was used to support leptospirosis transmission risk models and to find urban typologies at the study area. Variables based on RS were identified in the disease models and in the typologies characterization. This models and typologies also defined targets to look for in the high spatial resolution images. RS procedures were based on multi-level segmentation, object-based classification, aerial photography, QuickBird satellite images and street axis vector data of the Railroad Suburb of Salvador. In order to obtain the variable\'s values, results of QuickBird image processing were added to a geographic database and processed using vector and raster over layering techniques. At last, epidemiological analysis were initiated aiming to find its relationship with the urban elements and typologies identified using RS. The results points paved streets, streets wideness and house quality as the RS variables that have more influence on the leptospirosis transmission chance. The dissertation also presents research restrains, potentials, possible sources of bias and future studies proposals. It concludes that the RS based methodology presented is a powerful tool for urban analysis, due to its capabilities for identifying urban targets related to risky situations, and, therefore, for helping direct public investments to improve life conditions an unprivileged city areas.

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Pelcat, Yann S. „Soil landscape characterization of crop stubble covered fields using Ikonos high resolution panchromatic images“. Thesis, Winnipeg : University of Manitoba, 2006. http://www.collectionscanada.ca/obj/s4/f2/dsk3/MWU/TC-MWU-224.pdf.

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Thesis (M.Sc.)--University of Manitoba, 2006.
A thesis submitted to the Faculty of Graduate Studies in partial fulfillment of the requirements for the degree of Master of Science, Department of Soil Science. Includes bibliographical references.

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Mitar, Simić. „Prenosivi elektronski sistem za karakterizaciju i estimaciju parametara senzora“. Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2017. https://www.cris.uns.ac.rs/record.jsf?recordId=104950&source=NDLTD&language=en.

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Jedan od doprinosa ove disertacije je realizacija modela prenosivogmernog sistema za karakterizaciju senzora uz mogućnost daljinskogpristupa rezultatima merenja. U LTCC tehnologiji je fabrikovansenzor za merenje pH vrednosti, na bazi TiO2 filma na aluminasubstratu, koji je karakterisan razvijenim mernim sistemom. Izvršenaje i obrada podataka dobijenih prilikom karakterizacije senzoraformiranjem polinomske statičke karakteristike i modelovanjemsenzora ekvivalentnom električnom mrežom. Predložen je novineiterativni metod estimacije vrednosti parametara modela koji, upoređenju sa metodom najmanjih kvadrata, omogućava jednostavnijuestimaciju uz kraće vreme izvršavanja.
One of the contributions of this research is a model of the portable electronicmeasurement system for sensors characterization with remote access to themeasurement results. In LTCC technology a TiO2-based pH sensor isfabricated on the alumina substrate and it was characterized with developedmeasurement system. Experimentally obtained data was analyzed withpolynomial sensor characteristic as well as equivalent electric circuit (model).A new method for parameter estimation of the used 2R-1C model ispresented and comparison with complex nonlinear least squares wasperformed.

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Garlipp, Adriana Baggio. „Varia??o espacial e sazonal de elementos maiores e tra?os no estu?rios do Rio Curimata? (RN), atrav?s de dados geoqu?micos e de sensoriamento remoto“. Universidade Federal do Rio Grande do Norte, 2006. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18370.

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Made available in DSpace on 2015-02-24T19:48:45Z (GMT). No. of bitstreams: 1 AdrianaBG_capa_ate_secao5.pdf: 3230514 bytes, checksum: e499db1cdb9c0ab6b161220ff77e224a (MD5) Previous issue date: 2006-10-27
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The Curimata? estuary is located in the oriental coast of Rio Grande do Norte State in Brazil. Its importance resides in the fact that this region possesses one of the last portions of preserved mangrove in the Rio Grande do Norte State. Nevertheless, it has been severely affected by many anthropogenic activities, as sugarcane monoculture and shrimp farming. Former works demonstrated that an accumulation of heavy metals is occurring in oysters in this estuary, and perhaps it could be explained by the input of metals in this ecosystem deriving from the shrimp farming. To better understanding the origin of these metals, bottom sediment samples, cores and suspended particulate matter were collected for a characterization of metal concentrations (Al, Ba, Cd, Cu, Cr, Fe, Mn, Ni, Pb, Zn) and to determine the potentially bioavailable metals. Additionally, the enrichment ratio for each element analyzed was calculated. The mineralogical composition of sediment samples and cores were obtained by X-ray diffraction. Moreover, data of orbital remote sensing were used in order to detect and quantify suspended matter by applying a logarithmic algorithm. Geochemical data of bottom sediments and cores revealed that, excepting Ba and Pb, the elements analyzed presented concentrations characteristic of an unpolluted ecosystem (Al: 0,25 - 8,76 %; Ba: 3,03 - 870 ?g.g-1; Cd: < 0,25 ?g.g-1; Cr: 1,72 - 82,4 ?g.g-1; Cu: 0,12 -25,3 ?g.g-1; Pb: 0,38 - 23,7 ?g.g-1; Fe: 0,10 - 5,82 %; Mn: 15,1 - 815 ?g.g-1; Ni: 0,14 - 36,1 ?g.g-1; Zn: 1,37 - 113 ?g.g-1). During the dry season a distribution pattern was observed, with higher metal concentrations in the margins, decreasing toward the central portion of the channel. These metal concentrations were well correlated with mineralogical compositions, with clay minerals prevailing at the margins, and quartz and feldspar in the center. However, this pattern was not observed during the wet season, probably because of the high water flux that disturbed bottom sediments. But, as observed for the dry season, a good correlation between metal concentrations and mineralogical composition was also observed for the wet season, with high metal concentrations where there were high quantities of clay minerals. Low enrichment ratios were obtained for the majority of elements analyzed, excepting for Mn, Ba and Pb. Manganese presented the higher ratios downstream for both seasons, and it can be an evidence of anthropogenic impact by shrimp farming. As barium and lead concentrations in sediment samples presented analytical problems during the total sample digestion, one cannot be sure that the ratios obtained correspond to the reality. The highest metal concentrations in particulate matter were obtained in the portion dominated by fluvial transport for all metals analyzed, excepting for copper. Barium and zinc were the only elements that presented elevated concentrations that are not common of unpolluted ecosystems (Ba: 5730 - 8355 ?g.g-1; Zn: 3899 - 4348 ?g.g-1). However, these high concentrations could not be related to the shrimp farming and waste waters from the town of Canguaretama, once they were obtained from the fluvial particulate matter, that is upstream from the activities above mentioned. The application of the logarithmic algorithm to the processed LANDSAT image was well succeeded, although the acquired image does not correspond exactly to the field campaigns. The IKONOS image provided very detailed views of the suspended sediment concentration at the estuary, as the mixture of distinct water flows at the confluence of Cunha? and Curimata? rivers, with more turbid waters from Cunha? river, that is directly affected by effluents from shrimp farming and urban waste waters deriving from the town of Canguaretama
O estu?rio do rio Curimata? localiza-se na por??o sul do litoral oriental do Estado do Rio Grande do Norte, apresentando uma das ?ltimas por??es de manguezais no Estado. Este ecossistema tem sido fortemente afetado por diversas atividades antropog?nicas, como o cultivo de cana-de-a??car, a carcinicultura, al?m da urbaniza??o. Trabalhos anteriores neste local revelaram que ostras Crassostrea rhizophorae apresentaram concentra??es de alguns metais acima dos limites permitidos para consumo, e que talvez a entrada destes metais no estu?rio estivesse relacionada aos efluentes de carcinicultura. Para uma melhor compreens?o da origem destes metais, foram coletadas amostras de sedimento de fundo, testemunhos e material particulado em suspens?o para uma caracteriza??o das concentra??es de dez elementos maiores e tra?os (Al, Ba, Cd, Cu, Cr, Fe, Mn, Ni, Pb, Zn), bem como para a determina??o dos elementos potencialmente biodispon?veis. Al?m disso, tamb?m foi realizado o c?lculo da raz?o de enriquecimento para cada elemento analisado. A composi??o mineral?gica das amostras de sedimento de fundo e dos testemunhos foi obtida atrav?s de difratometria de raios-X. Adicionalmente, dados de sensoriamento remoto orbital foram usados a fim de se detectar e semiquantificar o material particulado em suspens?o atrav?s da aplica??o de um algoritmo logar?tmico. As an?lises geoqu?micas das amostras de sedimento de fundo revelaram que os elementos analisados apresentaram concentra??es caracter?sticas de um estu?rio n?o polu?do (Al: 0,25 a 8,76%; Ba: 3,03 a 870 ?g.g-1; Cd: < 0,25 ?g.g-1; Cr: 1,72 a 82,4 ?g.g-1; Cu: 0,12 a 25,3 ?g.g-1; Pb: 0,38 a 23,7 ?g.g-1; Fe: 0,10 a 5,82 %; Mn: 15,1 a 815 ?g.g-1; Ni: 0,14 a 36,1 ?g.g-1; Zn: 1,37 a 113 ?g.g-1). Um padr?o de distribui??o dos metais foi observado durante a esta??o seca, com maiores concentra??es nas margens, diminuindo em dire??o ao centro do canal. A concentra??o dos metais se mostrou bem correlacionada com as respectivas composi??es mineral?gicas das amostras de sedimento, com minerais de argila predominando nas margens, e quartzo e feldspato mais presentes no centro do canal. Contudo, este padr?o n?o foi observado durante a esta??o chuvosa, provavelmente devido ao fluxo de ?gua mais intenso que promoveu o dist?rbio dos sedimentos de fundo, com remo??o da fra??o fina das margens. Mas, da mesma forma que observado para a esta??o seca, nas amostras coletadas durante a esta??o chuvosa tamb?m se observou maiores concentra??es de metais nas amostras com predom?nio de minerais argilosos. Raz?es de enriquecimento sugestivas de aus?ncia de polui??o foram obtidas para a maioria dos elementos analisados, com exce??o de Mn. O mangan?s apresentou as maiores raz?es ? jusante da atividade de carcinicultura, as quais sugerem polui??o significativa neste trecho durante ambas as esta??es seca e chuvosa. Esta pode ser uma evid?ncia do impacto da carcinicultura no estu?rio, j? que a montante desta atividade a raz?o de enriquecimento foi baixa. No material particulado em suspens?o as maiores concentra??es de metais foram obtidas na por??o dominada pelo transporte fluvial para todos os elementos analisados, com exce??o do cobre. Os ?nicos elementos que apresentaram concentra??es elevadas, incomuns para ambientes livres de polui??o, foram b?rio (de 5730 a 8355 ?g.g-1) e zinco (de 3899 a 4348 ?g.g-1). Contudo, estas concentra??es anormais aparentam n?o estar relacionadas ? carcinicultura ou aos efluentes da cidade de Canguaretama, uma vez que foram encontrados ? montante destas atividades. A aplica??o do algoritmo logar?tmico ? imagem LANDSAT foi bem sucedida, embora a imagem adquirida n?o corresponda exatamente ?s datas de coleta do material em suspens?o. A imagem IKONOS forneceu vis?es muito detalhadas do estu?rio que permitiram observar a distribui??o do material particulado, com a mistura de fluxos de ?gua distintos na conflu?ncia dos rios Cunha? e Curimata?, sendo que o rio Cunha? apresenta ?guas mais turvas, e ? diretamente afetado pelos efluentes de carcinicultura e dejetos urbanos da cidade de Canguaretama

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Harasim, Tomáš. „Návrh diagnostické soustavy pro malý dopravní letoun“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231664.

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Due to the airliners and aircraft operators pressure on reducing the operating costs, the diagnostic systems are included in aircraft, so that the wearness of single functional elements of other functional systems can be monitored. This monitoring can save money, that are usually spent on maintenance and especially, it leads to an increase of the overall safety of aircraft operations. The task of this work is to design a diagnostic system for small transport aircraft. For the right and proper design, is the correct understanding of the functions of each part on aircraft systems needed. The part of this work is attended to the selection procedure of appropriate diagnostic parameters, next section deals with the suitable options of their scanning. I do mention the summary of the chosen diagnostic parameters for the scanning and the recomended ways of their measuring.

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Hung, Cheng-Hsun, und 洪晟薰. „Application of Inertial Sensing Element in Attitude Sensing“. Thesis, 2018. http://ndltd.ncl.edu.tw/handle/xpf762.

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碩士
健行科技大學
電機工程系碩士班
106
The purpose of this paper is to study the application of inertial sensing element (IMU) in attitude sensing. We use the inertial sensing element made two examples, namely: two-wheeled balance car and smart rear-view mirror. Two-wheel balancing vehicles use inertial sensors to read acceleration and gyroscope signals, and use complementary filters to convert attitude angles. The tilt angle is controlled by PID to keep the body balanced. Another example is the design of a smart rear-view mirror, the inertial sensing element designed to detect the position of the knight in the swing, and then convert the position into the control of the rearview mirror message. Increase the field of view of the rearview mirror reduce the blind spot of the view and improve the alertness of the locomotive rider to the rear and hope to reduce the accident rate of the motorcyclist.

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49

Syu, Bo-Jhih, und 許博智. „Graphical Porous Silicon Optical Sensing Element“. Thesis, 2013. http://ndltd.ncl.edu.tw/handle/20749721710142833979.

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碩士
聖約翰科技大學
電子工程系碩士班
101
In this thesis, the main use of laser engraving machine, the porous silicon experiments graphical two thicknesses of 525 μm and 230μm P-type silicon, experimental preparation before the coupons will be clean, then the surface of the specimen with Blue Tape lamination on, laser engraving machine engraving graphics on Blue Tape, 5 each triangle, round, square, carved out of the basket empty graphics, The total area of each graphic shape are 3 mm2 of parallel electric current disparity under etching experiment and analysis. After the experiment, of record test piece under the UV lamp 254 nm and 365 nm bands of light irradiation, the color of the light of the excitation light, spectrum analyzer (Maple PL), observation of the luminescence of porous silicon in the graphic relative intensity and band distribution range, to observe the surface structure of graphics inside the porous silicon and then a scanning electron microscope (Scanning Electron Microscope, SEM), measurement using 3D surface profiler (3D Profile) structure and roughness and depth, then I-V measurement instrument, Four cases in fluorescent lamps, black box, halogen lamps, and UV light, etc. Electrical characteristic curve analysis progress. Specimen thickness of 230 μm, pattern is triangular, the concentration ratio of 1:2, the constant voltage, the time is 15 minutes resistance change, Due to the specimen thickness of 230 μm columnar, the thickness of the specimen will affect the structure of the porous silicon; different graphics under current the corner of the etching, lead to the corner of the porous silicon is less; etching concentration ratio of 1:2 porous silicon plate and columnar structure significantly, Etching a concentration of 1:3, only cracks The etching time was 15 minutes excited by the light intensity of light, in the future Laser engraving machine engraving more complex graphics can be used. Keyword : Laser engraving machine, I-V measurement instrument, Electrical characteristic curve.

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YEH, YU-MING, und 葉毓銘. „A Finite Element Analysis of Load Sensing in Fastener Forming“. Thesis, 2018. http://ndltd.ncl.edu.tw/handle/kkz75v.

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碩士
國立高雄應用科技大學
模具工程系
106
Fastener manufacturing is a fundamental and important industry in Taiwan and it provides the annual export value reached 4 billion U.S. dollars since 2014. The monitoring methods of the fastener forming process are still widely based on automatic inspection of visual aids or hand measurement methods. However, in this condition, fastener machines usually can not be found any mistake on time until defects are found. These methods not only waste material, but also may make die damage. Moreover, the more maintenance schedules arrange the fewer capacity companies have so it becomes the key to the profitability of the company. It’s quite diverse for fasteners forming process of immediate monitoring, mainly based on axial load in the past. Because of the large load, finding tiny abnormal load such as cavity material, die cracking and punch collapse is complicated and difficult. This study uses DEFORM-3D finite element analysis software for forming analysis and abnormal load sensing through lateral loads to complement the blind spot of axial sensing. These two methods are major breakthrough in skills and concepts to enhance the robustness and competitiveness of Taiwan industrial monitoring process. In this study, hexagonal flange bolts, hexagonal flange nuts and thread rolling of forging force analysis were performed by using forming loads (forging force) to investigate the abnormal load caused by factors such as workpiece variation, friction factor variation, cavity material, die cracking and punch collapse. That simulation analysis presents the connection between the abnormal load curve and the cause of the defect shows that the axial load value is large and difficult to distinguish the signal of forming defects. In normal forming, the lateral load will offset each other due to the symmetrical flow of materials, but in the event of a forming defect the sensing will be more sensitive. Therefore, it can effectively identify defects such as cavity material, die cracking or punch collapse, and even can predict its position and size.

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