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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Assessing the Long-term Impacts of White-nose Syndrome on Bat Communities Using Acoustic Surveys at Fort Drum Military Installation

Nocera, Tomas 12 June 2018 (has links)
With declines in abundance and changing distribution of White-nose Syndrome (WNS)-affected bat species, increased reliance on acoustic monitoring is now the new "normal". As such, the ability to accurately identify individual bat species with acoustic identification programs has become increasingly important. Additionally, how bat distribution and habitat associations have changed at the local to sub-landscape scale in the post WNS environment is important to understand. The significance of these changes, relative to bat activity, may be based on the species-specific susceptibility to WNS. We used data collected from Fort Drum Military Installation, New York from the summers of 2003-2017 to analyze the accuracy of acoustic software programs, and assess the changes in relative bat activity, occupancy, and distribution induced by WNS. Our results indicate that continued acoustic monitoring of bat species, such as the little brown bat (Myotis lucifugus) in the Northeast, to assess ongoing temporal and spatial changes, habitat associations, and as a guide to direct future mist-netting should rely more on relative activity as the metric of choice. Furthermore, the continuous spread of WNS across North America will have strong negative effects on bat populations and communities, this study points to how individual species (both impacted and non-impacted) will respond to WNS. We believe that our results can help users choose automated software and MLE thresholds more appropriate for their needs to accurately address potential changes in communities of bat species due to impacts of WNS or other factors. / MS / White-nose Syndrome (WNS), was first documented in the United States in 2006. The fungus that causes WNS grows on the exposed tissues of hibernating bats and causes abnormal frequent arousal and activity through winter that consequently leads to premature loss of critical fat reserves and disruption of water balance. To date millions of cave-hibernating bats have been killed by White-nose Syndrome. With declines in abundance and changing distribution of WNS-affected bat species, the ability to accurately identify individual bat species with acoustic identification programs has become increasingly important. Additionally, how bat distribution and habitat associations have changed at the local to sub-landscape scale in the post WNS environment is important to understand. We used data collected from Fort Drum Military Installation, New York from the summers of 2003-2017 to analyze the accuracy of acoustic software programs, and assess the changes in relative bat activity, occupancy, and distribution induced by WNS. Looking at this disease through time is important because it allows us to predict how bat communities in areas where the disease has not yet reached may change if there is an outbreak. Our results indicate that continued acoustic monitoring of bat species in the Northeast, to assess ongoing temporal and spatial changes, habitat associations, and as a guide to direct future mist-netting should rely more on relative activity as the metric of choice. This information can be directly applied with on the ground management for bats, which can buffer against the additional consequences this disease has on bat populations.
182

Spatial Ecology and Conservation Strategies for the Endangered Northern Long-Eared Bat (<i>Myotis septentrionalis</i>) in a Post-White-Nose Syndrome Landscape

De La Cruz, Jesse L. 18 November 2024 (has links)
The endangered northern long-eared bat (<i>Myotis septentrionalis</i>) has experienced severe population declines since the 2007 introduction of <i>Pseudogymnoascus destructans</i>, the fungal pathogen that causes white-nose syndrome (WNS). Due to continued mortality, failed recruitment, and range fragmentation, effective species conservation would benefit from local and regional research related to habitat selection and suitability, seasonal activity, and large-scale estimates of continued occupancy across the post-WNS landscape. In this dissertation, I explored maternity colony home range size and habitat selection, both coastal and interior seasonal activity patterns, habitat suitability, and species occupancy trends in the Mid-Atlantic and Northeastern United States. Research from the Coastal Plain of North Carolina, based on diurnal roost locations, revealed that core and peripheral home range estimates were large but comparable to areas of contiguous forest cover in other regions of the species' range. Prior to juvenile volancy, female northern long-eared bats selected red maple (<i>Acer rubrum</i>), water ash (<i>Fraxinus caroliniana</i>), and loblolly pine (<i>Pinus taeda</i>) as day-roosts, but then used sweetgum (<i>Liquidambar styraciflua</i>), swamp bay (<i>Persea palustris</i>), and water tupelo (<i>Nyssa aquatica</i>) after juvenile volancy. At the second-order spatial scale (i.e., home range within a region), roosting home ranges were associated with woody wetlands farther from anthropogenic development and open water. However, within the third-order scale (i.e., core home range within a periphery), northern long-eared bats selected woody wetlands adjacent to intact upland forests, areas containing shorter trees and occurring proximal to open water. Research utilizing passive acoustic monitoring on the Coastal Plain of both Virginia and North Carolina found that northern long-eared bat relative activity was highest in areas containing greater proportions of woody wetlands and upland pine-dominated evergreen forests. Conversely, the likelihood to record northern long-eared bats was associated with smaller proportions of woody wetlands and open water resources, emphasizing the importance of upland forests adjacent to these features. I also observed a higher probability of recording northern long-eared bats during non-winter seasons and when temperatures were between 10 and 25 °C, potentially highlighting an optimal thermoneutral zone for the species regionally. Research using presence data from the Monongahela National Forest (MNF) in the Central Appalachians of West Virginia found that northern long-eared bat habitat, whether occupied or not, was abundant (43.1% of the MNF) and widely dispersed. Northern long-eared bat habitat on the MNF was often characterized as mature, interior mixed mesophytic forests. Research using passive acoustic surveys associated with hibernacula in western Virginia found that northern long-eared bats were most active near hibernacula during warmer weeks of the fall swarm and spring emergence, when rainfall was low. Similarly, the probability of northern long-eared bat activity was highest near hibernacula during the spring/summer season. However, unlike relative activity, the likelihood of recording northern long-eared bats was associated with more heterogeneous, interior forests. Finally, research using a combination of long-term repeated and single-season clearance survey data from New England found that northern long-eared bat occupancy was highest on steep hillsides in contiguous forested landscapes with minimal anthropogenic development. My results also indicated higher occupancy of northern long-eared bats in warmer regions, particularly along the New England coastline and offshore islands. These findings collectively stress the importance of managing areas of large core forest to promote sustainable roost formation and productive foraging areas, often associated with dynamic ecotones, to support the survival and recovery of northern long-eared bats in the post-WNS Mid-Atlantic and Northeast. / Doctor of Philosophy / The northern long-eared bat was once one of the most common bat species in North America. However, due to population impacts caused by white-nose syndrome (WNS) the species is now recognized as endangered by the United States Fish and Wildlife Service. In this dissertation, I explore habitat selection and suitability, seasonal activity, and occupancy trends of remnant populations of northern long-eared bats in the Mid-Atlantic and Northeast of the United States, representing approximately 25% of the species' historical range. Specifically, I examined home range size and habitat selection of a reproductively successful maternity colony on the Mid-Atlantic Coastal Plain, overwintering activity at both interior and coastal sites, habitat suitability in the Central Appalachians, and spatial occupancy trends across New England. My research found that reproductive northern long-eared bats actively selected for specific cover features and displayed notable shifts in roost tree selection throughout the maternity season on the Coastal Plain of North Carolina. My research also indicated that northern long-eared bats were more active during non-winter seasons, favoring moderate temperatures and areas of forested wetlands adjacent to evergreen forests in coastal North Carolina and Virginia. In Virginia, northern long-eared bat activity near mountain hibernacula was highest in areas of greater landscape richness prior to and after hibernation. Finally, my research from New England found that northern long-eared bat occupancy was highest in steeper, forested landscapes in the absence of human development. Overall, this research highlights the need to conserve and manage forest ecosystems to promote recovery of the endangered northern long-eared bat. Conservation and management efforts informed by population status, activity trends, and habitat associations will be invaluable in guiding species recovery efforts.
183

Tillståndsövervakning av rullningslager med hjälp av E-näsa

Kristiansen, Pontus, Postnikov, Roman January 2018 (has links)
I dagsläget finns det ingen standardiserad metod för att mäta en enhets tillstånd medhjälp av dofter. Vid tillståndsövervakning av rullningslager är vibrationsmätning denmest dominanta metoden. I samband med vibrationsmätning används i vissa falltemperaturövervakning för att få en bättre insikt på rullningslagrets tillstånd. I det härarbetet undersöks de om en elektronisk näsa kan avgöra ett rullningslagers tillstånd.Innan några mätningar påbörjas monterades en elektronisk näsa ihop i ett hölje sombestår av ett kretskort, metalloxid-sensorer och en fläkt för att styra dofter med ettkonstant flöde mot sensorerna. Den elektroniska näsan styrs av en Arduino Nanomikrokontroller. Utöver e-näsan sättes en enhet ihop tillhörande två temperaturgivareoch en luftfuktighetsgivare som styrs av en Arduino UNO. Enhetens syfte är att kunnakontrollera de rådande förhållandena vid mätningar och för att leta någon form avkorrelation mot e-näsan vid eventuella utslag. Förstörande prover av kullager utfördesför att se om e-näsan reagerar innan ett lagerhaveri. Testerna gjordes i en öppen samtsluten miljö och tre stycken olika oljor används för att smörja lagret. Detta för att seom e-näsan reagerar olika beroende på vilken olja som används. En undersökningutförs ifall den elektroniska näsan kan separera på de tre oljorna som används ilagertesterna. För att utvärdera mätresultaten används Excel och Minitab, därprincipalkomponentanalyser genomförs på all mätdata. Efter att alla lagerprover harverkställts utfördes en uppföljning av rullningslagrena för att studera deras tillstånd,detta genom ett optiskt mikroskop.Det framgår i rapporten att med hjälp av analysmetoden PCA syns det att denelektroniska näsan kunde skilja på hydraulolja, motorolja och växellådsolja. Utslag iPCA för de olika mätserierna blev inte identiska men det blev tydligaklusterindelningar hos samtliga mätserier. Genomförd studie visade att med delagerhaveri samt temperaturer går det inte att avgöra ett kullagers tillstånd med hjälpav en elektronisk näsa. Eftersom att de specifika gas-sensorerna som användes till enäsaninte gav någon form av utslag vid mätningarna. Den elektroniska näsanreagerade däremot vid totalhaveri av kullager, vilket är för sent i ett förebyggandeunderhållsperspektiv. Detta medförde att den elektroniska näsan inte kan användas förtillståndsövervakning av det specifika kullagret som användes vid denna studie. / At present, there is no standardized method of measuring a device's condition with thehelp of odors. In condition monitoring of rolling bearings, vibration measurement isthe most dominant method. In case of vibration measurement, temperature monitoringis used in some cases to get a better insight into the condition of the bearing. In thiswork, it is investigated whether an electronic nose can determine the condition of arolling bearing.Before any measurements began, an electronic nose is assembled in a housingconsisting of a circuit board, metal oxide sensors and a fan for stearing odors with aconstant flow towards the sensors. The electronic nose is controlled by an ArduinoNano which is a microcontroller. In addition to the e-nose, a unit is connected to twotemperature sensors and a humidity sensor controlled by an Arduino UNO. The unit'spurpose is to monitor the status and to look for any kind of correlation with the e-nosein case of any possible findings. Destructive specimens of ball bearings are performedto see if the e-nose responds prior to a bearing failure. Tests are conducted in an openand closed environment and three different oils are used to lubricate the bearings.This to see if the e-nose acts differently depending on the oil that is used. Aninvestigation is conducted if the electronic nose can separate the three different typesof oils that is used in the destructive bearing tests. To evaluate the measurementresults, Excel and Minitab are used, where principal component analysis is performedon all measurement data. After all bearing tests have been performed, a follow-up ofthe rolling bearings condition is performed, this through an optical microscope.The report shows that using the PCA analysis method, it appears that the electronicnose could distinguish between hydraulic oil, engine oil and gear oil. In the PCA forthe different measurement series the results did not become identical, but clusterdivisions became clear in all measurement series. Completed study showed that withthese bearing failures and temperatures, it is not possible to determine the condition ofthis ball bearer using an electronic nose. Because the specific gas sensors used for thee-nose did not give any kind of impact during the measurements. On the other hand,the electronic nose responded to a total failure of a ball bearing, which is too late in apreventative maintenance perspective. Therefore, the electronic nose cannot be usedfor condition monitoring of the specific ball bearing used in this study.
184

E-noses equipped with Artificial Intelligence Technology for diagnosis of dairy cattle disease in veterinary / E-nose utrustad med Artificiell intelligens teknik avsedd för diagnos av mjölkboskap sjukdom i veterinär

Haselzadeh, Farbod January 2021 (has links)
The main goal of this project, running at Neurofy AB, was that developing an AI recognition algorithm also known as, gas sensing algorithm or simply recognition algorithm, based on Artificial Intelligence (AI) technology, which would have the ability to detect or predict diary cattle diseases using odor signal data gathered, measured and provided by Gas Sensor Array (GSA) also known as, Electronic Nose or simply E-nose developed by the company. Two major challenges in this project were to first overcome the noises and errors in the odor signal data, as the E-nose is supposed to be used in an environment with difference conditions than laboratory, for instance, in a bail (A stall for milking cows) with varying humidity and temperatures, and second to find a proper feature extraction method appropriate for GSA. Normalization and Principal component analysis (PCA) are two classic methods which not only intended for re-scaling and reducing of features in a data-set at pre-processing phase of developing of odor identification algorithm, but also it thought that these methods reduce the affect of noises in odor signal data. Applying classic approaches, like PCA, for feature extraction and dimesionality reduction gave rise to loss of valuable data which made it difficult for classification of odors. A new method was developed to handle noises in the odors signal data and also deal with dimentionality reduction without loosing of valuable data, instead of the PCA method in feature extraction stage. This method, which is consisting of signal segmentation and Autoencoder with encoder-decoder, made it possible to overcome the noise issues in data-sets and it also is more appropriate feature extraction method due to better prediction accuracy performed by the AI gas recognition algorithm in comparison to PCA. For evaluating of Autoencoder monitoring of its learning rate of was performed. For classification and predicting of odors, several classifier, among alias, Logistic Regression (LR), Support vector machine (SVM), Linear Discriminant Analysis (LDA), Random forest Classifier (RFC) and MultiLayer perceptron (MLP), was investigated. The best prediction was obtained by classifiers MLP . To validate the prediction, obtained by the new AI recognition algorithm, several validation methods like Cross validation, Accuracy score, balanced accuracy score , precision score, Recall score, and Learning Curve, were performed. This new AI recognition algorithm has the ability to diagnose 3 different diary cattle diseases with an accuracy of 96% despite lack of samples. / Syftet med detta projekt var att utveckla en igenkänning algoritm baserad på maskinintelligens (Artificiell intelligens (AI) ), även känd som gasavkänning algoritm eller igenkänningsalgoritm, baserad på artificiell intelligens (AI) teknologi såsom maskininlärning ach djupinlärning, som skulle kunna upptäcka eller diagnosera vissa mjölkkor sjukdomar med hjälp av luktsignaldata som samlats in, mätts och tillhandahållits av Gas Sensor Array (GSA), även känd som elektronisk näsa eller helt enkelt E-näsa, utvecklad av företaget Neorofy AB. Två stora utmaningar i detta projekt bearbetades. Första utmaning var att övervinna eller minska effekten av brus i signaler samt fel (error) i dess data då E-näsan är tänkt att användas i en miljö där till skillnad från laboratorium förekommer brus, till example i ett stall avsett för mjölkkor, i form av varierande fukthalt och temperatur. Andra utmaning var att hitta rätt dimensionalitetsreduktion som är anpassad till GSA. Normalisering och Principal component analysis (PCA) är två klassiska metoder som används till att både konvertera olika stora datavärden i datamängd (data-set) till samma skala och dimensionalitetsminskning av datamängd (data-set), under förbehandling process av utvecling av luktidentifieringsalgoritms. Dessa metoder används även för minskning eller eliminering av brus i luktsignaldata (odor signal data). Tillämpning av klassiska dimensionalitetsminskning algoritmer, såsom PCA, orsakade förlust av värdefulla informationer som var viktiga för kllasifisering. Den nya metoden som har utvecklats för hantering av brus i luktsignaldata samt dimensionalitetsminskning, utan att förlora värdefull data, är signalsegmentering och Autoencoder. Detta tillvägagångssätt har gjort det möjligt att övervinna brusproblemen i datamängder samt det visade sig att denna metod är lämpligare metod för dimensionalitetsminskning jämfört med PCA. För utvärdering of Autoencoder övervakning of inlärningshastighet av Autoencoder tillämpades. För klassificering, flera klassificerare, bland annat, LogisticRegression (LR), Support vector machine (SVM) , Linear Discriminant Analysis (LDA), Random forest Classifier (RFC) och MultiLayer perceptron (MLP) undersöktes. Bästa resultate erhölls av klassificeraren MLP. Flera valideringsmetoder såsom, Cross-validering, Precision score, balanced accuracy score samt inlärningskurva tillämpades. Denna nya AI gas igenkänningsalgoritm har förmågan att diagnosera tre olika mjölkkor sjukdomar med en noggrannhet på högre än 96%.
185

排灣族鼻笛文化之民族誌調查 - 平和排灣的個案研究 / An Ethnographical Result on the Nose Flute Culture of Paiwan - a Case Study of Pinghe Paiwanese

曾如敏, Tseng,Ju-Ming Unknown Date (has links)
至屏東 花蓮 台東田調 探討排灣族的鼻笛笛文化 / Through fieldwork in Pingtung, Taitung and Hualien, the researcher gained first-hand data for this thesis. This thesis introduces the ethnography, environment, material culture, spiritual civilization and social structure of the Paiwan. This research is not limited to the technical aspects of Paiwanese nose flute art, and their playerts, but also discusses the making of nose flutes and the people who are able to play them. The paper discusses the myths and origins of nose flutes and the formation of nose fltue culture. The research focuses on the social function of nose flutes through analysis of the flutes and the symbols they represent. To the Paiwan, nose flutes represent the sound of hundred-pace snakes, the wooing of girls, sorrow and memories, the gathering together of friends and performing of wedding rites. Finally, the research examines the continuity and promotion of nose flute culture, including periods of decline and of changing factores in the culture.
186

Das nasale Erscheinungsbild nach sekundärer Spaltnasenkorrektur: Vergleich zwischen professioneller Bewertung und Patientenzufriedenheit

Unger, Carolin 29 March 2017 (has links) (PDF)
Patienten mit Lippen-Kiefer-Gaumenspalten weisen häufig ein ästhetisches Defizit im Bereich der Nase auf und müssen sich nach Wachstumsabschluss nicht selten einer Nasenkorrektur unterziehen. Die in der Literatur publizierten Ergebnisse von Spaltnasenkorrekturen sind zum Teil kontrovers und bilden verschiedene Blickwinkel ab. Bewertungen von Patienten und Therapeuten unterscheiden sich mitunter erheblich. Ziel dieser retrospektiven Studie war es, zu ermitteln, welche funktionellen und ästhetischen Resultate mit Hilfe der Sekundärkorrektur der spaltbedingten Nasendysplasie zu erzielen sind und wie sich der Blickwinkel der Patienten von denen professioneller Juroren unterscheidet. Hierfür konnten 242 Patientinnen und Patienten mit Lippen-Kiefer-Gaumenspalten eingeschlossen werden, welche sich im Zeitraum vom 01.01.2001 bis 31.12.2013 an der Klinik für Mund-, Kiefer- und Plastische Gesichtschirurgie des Universitätsklinikums Leipzig einer sekundären Rhinoplastik unterzogen hatten. Aus Sicht der Patienten wurde hinsichtlich der Funktion in 82% der Fälle ein gutes Ergebnis erreicht. Bezüglich der Ästhetik beurteilten die Patienten das Ergebnis zu 74% als gut und zu 21% als moderat. Die identische Befragung der professionellen Jury ergab in 65% der Fälle die Einschätzung gut und in 26% der Fälle die Bewertung moderat. Die vergleichende statistische Analyse der Einschätzungen der beiden Kollektive ergab eine nur geringe Interrater-Reliabilität. Die Ergebnisse der Studie zeigen, dass in der Mehrzahl der Fälle gute Resultate erzielbar sind. Die Bewertungen der Patienten und jene der Ärzte differieren dabei deutlich.
187

Adaptation d'un nez électronique pour le contrôle de la concentration et de l'humidité d'une atmosphère chargée en huile essentielle destinée à un effet thérapeutique médical / Adaptation of an electronic nose to control concentration and humidity of an essential oil charged atmosphere for medical therapeutic effect

Sambemana, Herizo 20 June 2012 (has links)
De nombreuses études récentes, basées sur des indicateurs physiologiques ou psychologiques, mettent en évidence les pouvoirs stimulants ou apaisants des odeurs sur des personnes souffrant de déficiences neurosensorielles. Or l'évaluation quantitative (rigoureuse, scientifique) des effets d'une stimulation olfactive à base d'huiles essentielles, nécessite de pouvoir contrôler de manière exacte et automatique la quantité de substances actives présentes dans l'air inhalé par le patient. Ce travail concerne la conception et la réalisation d'un système « diffuseur/détecteur » de gaz capable de générer des doses contrôlées d'huile essentielle dans l'atmosphère conditionnée d'une salle d'expérimentation. La diffusion est basée sur le contrôle de l'air bullant dans l'huile essentielle liquide (pin, lavande, orange douce), dont l'analyse physico-chimique et sensorielle nous a aidés à choisir leur domaine de concentrations. La détection des substances volatilisées est obtenue à l'aide d'un réseau de capteurs à oxydes métalliques commerciaux. L'analyse de signaux de réponse des capteurs aux différentes concentrations de l'huile de pin, après un filtrage numérique adéquat, a révélé une bonne sensibilité croisée des capteurs tant au niveau de la réponse temporelle qu'au niveau de sa courbe dérivée. Ainsi, nous avons pu extraire plusieurs paramètres représentatifs des réponses, habituellement utilisés dans la littérature, et surtout de nouveaux paramètres, caractéristiques de la phase dynamique, pour former la base d'apprentissage. L'analyse à l'aide de méthodes de classification (non supervisée puis supervisée) nous a permis de mettre en évidence la meilleure combinaison de paramètres pour une identification rapide et fiable de concentrations voisines. L'application aux deux autres huiles essentielle a été concluante, nous pouvons envisager de réaliser un prototype pour les essais de validation thérapeutique / Recent clinical studies have demonstrated the stimulating or relaxing effects of odorous stimulation on subjects suffering from neuro-sensoriel deficiencies. These studies concern generally the variation measurement of physiological parameters or psychological indicators in relation with odorous stimuli. To evaluate quantitatively the odorous effects of natural oil stimulations on the subject behavior or his cognitive performance, it is necessary to control automatically and accurately the quantity of the active substances present in the air inhaled by the patient. The aim of this work is to conceive a gas ?diffuser/detector? system to generate fixed concentration of an essential oil in an experimental chamber atmosphere. Diffusion unit is based on the control of the air flow arte bubbling through the liquid oil (pin, lavender, orange), and the range of the employed concentration range is determined after physic-chemical and sensorial analysis. The detection of volatilized substances is obtained using a matrix of commercial metal oxide gas sensors. The study of the sensor responses to different pin oil concentrations showed, after an adequate digital filtering, a good cross sensitivity of the sensors. So, we have extracted from each sensor response, several characteristic parameters, firstly classical ones, and then new ones representing the dynamic phase of the signal response, to create the learning data base. The analysis of these data using pattern recognition methods (non-supervised and then supervised) permitted us to highlight a set of parameters for a reliable and rapid identification of closed diffused oil concentrations. The application of the system with the two other oils was decisive: we can now carry out the realization of a prototype for the therapeutic tests
188

Conception et développement d'un système multicapteurs en gaz et en liquide pour la sécurité alimentaire / Design and development of a gas and liquid multisensors system for food safety

Haddi, Zouhair 16 December 2013 (has links)
Les systèmes de nez et de langues électroniques à base de capteurs chimiques et électrochimiques constituent une solution avantageuse pour la caractérisation des odeurs et des saveurs émanant des produits agroalimentaires. La sélectivité croisée de la matrice des capteurs couplée aux méthodes de reconnaissance de formes est l'élément clé dans la conception et le développement de ces systèmes. Dans cette optique, nous avons démontré la capacité d'un dispositif expérimental de nez électronique à discriminer entre les différents types de drogues, à analyser la fraîcheur des fromages, à identifier entre les fromages adultérés et à différentier entre les eaux potables et usées. Nous avons également réussi à classifier correctement les eaux potables (minérales, de source, gazeuse et de robinet) et usées par utilisation d'une langue électronique potentiométrique. Cette étude a été validée par la Chromatographie en Phase Gazeuse couplée à la Spectrométrie de Masse (CPG-MS). En outre, nous avons développé une langue électronique voltammétrique à base d'une électrode de Diamant Dopé au Bore pour différencier les phases de traitement des eaux usées domestiques et hospitaliers et pour identifier les différents métaux lourds (Pb, Hg, Cu, Cd, Ni et le Zn) contenus dans l'eau du fleuve Rhône. La Voltammétrie à Redissolution Anodique à Impulsion Différentielle (DPASV) a été utilisée comme une méthode électrochimique pour caractériser les eaux étudiées. Enfin, les systèmes multicapteurs hybrides se sont avérés un bon outil analytique pour caractériser les produits de l'industrie agroalimentaire tels que les jus tunisiens et les huiles d'olives marocaines / Electronic noses and tongues systems based on chemical and electrochemical sensors are an advantageous solution for the characterisation of odours and tastes that are emanating from food products. The cross-selectivity of the sensor array coupled with patter recognition methods is the key element in the design and development of these systems. In this context, we have demonstrated the ability of an electronic nose device to discriminate between different types of drugs, to analyse cheeses freshness, to identify adulterated cheeses and to differentiate between potable and wastewaters. We have also succeeded to correctly classify drinking waters (mineral, natural, sparkling and tap) and wastewaters by using a potentiometric electronic tongue. This study was validated by Gas Chromatography coupled with Mass Spectrometry (GC-MS). Furthermore, we have developed a voltammetric electronic tongue based on a Diamond Doped Boron electrode to differentiate treatment stages of domestic and hospital wastewaters and to identify different heavy metals (Pb, Hg, Cu, Cd, Ni and Zn) contained in Rhône river. The Differential Pulse Anodic Stripping Voltammetry (DPASV) was used as an electrochemical method to characterise the studied waters. Finally, the hybrid multisensor systems have proven to be good analytical tools to characterise the products of food industry such as Tunisian juices and Moroccan olive oils
189

Minhund och en elektronisk nos för detektion av minor : utifrån den militära nyttan vid en undsättningsinsats / Mine detection dog and an electronic nose for landmine detection : on the basis of the military utility in a mine rescue team operation

Linfeldt, Anna January 2013 (has links)
Minor utgör ett hot mot civilbefolkningen men även personal i fredsfrämjande insatser riskerar att skadas av minorna under patruller i insatsområdet. Idag används minhunden i Försvarsmakten för att lokaliera minor i kombination med minpik och metalldetektor. Hunden har sina begränsningar och har under flera perioder varit på väg att fasas ut till förmån för tekniken. Minans doftbild, minhunden och den elektroniska nosen beskrivs och mynnar ut i en analys där för-/nackdelar presenteras och därefter diskuteras. Den militära nyttan i den militära kontexten, insats med undsättningsstyrka (MRT) utgör ramverk i uppsatsen. Vid en undsättningsinsats med MRT är det av största vikt att minorna kan lokaliseras, märkas ut och undvikas. Hunden har förmåga till lokalisering av minor vilket den elektroniska nosen Fido saknar. Minornas doftbild överlappar varandra. Fido kan inte särskilja minorna från varandra utan endast bekräfta förekomst i ett område vilket inte bidrar till den militära nyttan när en fri väg ska sökas fram till en skadeplats. / Landmines pose a threat to the civilian population but personnel in peacekeeping operations could also be harmed by landmines during patrols in the area. Today the Swedish Armed Forces use mine detection dogs to locate landmines. The mine detection dogs are used in combination with prodders and metal detectors. The dogs have their limitations and there have been several attempts to phase them out and replace them with technology. Substances detected by dogs and electronic noses, the mine detection dog and the electronic dog nose Fido are described and incorporated in an analysis where advantages/disadvantages are presented and then discussed. Military utility in a military context constitute the frame of the essay. The military context is an operation with a mine rescue team to rescue an injured person in a mine field. In a rescue operation with a mine rescue team the most important thing is to locate, mark and avoid the landmines. The dog can locate landmines but the electronic nose Fido cannot. The chemical signatures from the landmines overlap each other making it difficult for Fido to pinpoint the exact location. Fido can confirm the presence of landmines in an area which does not have military utility during mine rescue team operations to find a free path and rescue an injured person out from a minefield.
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Etude du fraisage de l'alliage de titane Ti-6AI-4V : influence des angles de coupe et des rayons de bec sur l'intégrité de surface et la limite d'endurance des pièces / Effects of cutting angles and nose radius in Ti-6AI-4V milling process on surface integrity and fatigue limit

Cellier, Adrien 23 October 2013 (has links)
Cette étude s’est focalisée sur l’influence d’une opération de fraisage sur l’intégrité de surface et la durée de vie en fatigue des pièces usinées en titane (Ti-6Al-4V). L’influence des paramètres géométriques tels que les angles de coupe et les rayons de bec sur la performance de l’outil à savoir la durée de vie de l’outil est analysée. Une deuxième partie est consacrée à l’influence des paramètres géométriques sur l’intégrité de surface définie par des facteurs tels que la topographie, les contraintes résiduelles, la dureté et la microstructure. Afin de déterminer la nature des contraintes résiduelles, une approche thermomécanique a été utilisée. Une relation entre les contraintes résiduelles et la dureté sous la surface usinée est établie. Une dernière partie est dédiée à la l’étude de la fatigue des pièces en titane usinées selon les différents paramètres géométriques. Une comparaison des limites d’endurance expérimentales et analytiques issue de la littérature a permis de déterminer les paramètres influents de l’intégrité de surface sur la performance en fatigue. Une analyse fractographique a révélé les phénomènes liés à l’usinage influençant la rupture du matériau. / This study is carried out on the influence of milling process on surface integrity and fatigue life of a titanium alloy (Ti-6Al-4V). Geometric parameters like cutting angles and nose radius are investigated. In the first part, the observation is focused on tool life. The second part is dedicated to the influence of geometric parameters on surface integrity which is defined by topography, residual stress, hardness and microstructure. To determine the nature of the residual stresses a thermomechanical approach is used. A relation between residual stress and hardness is established. The last part deals with the study of the fatigue of milled titanium samples. A comparison is made between experimental fatigue limit and analytical fatigue limit of a model from literature. With this comparison, the most influential factor of surface integrity on fatigue limit is determined. A fractography analysis reveals the phenomenon related to milling process which can influence the material rupture.

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