En ultraljudstransducer är ett välkänt instrument inom medicintekniska industrin. Det finns flera olika typer av transducers med varierande egenskaper. Ett gemensamt mål med dessa transducers är diagnostisering, behandling samt uppföljning av behandlingen. Projektet gick ut på att utforska gränserna för hur små en transducer kan skapas samt hur dessa presterar. Dessutom är projektet en fortsättning på ett tidigare exjobb som utfördes våren 2021. Syftet är att expandera på förra arbetets omfång där det lämnade samt att förbättra de befintliga resultaten. Transducern i fråga har en simpel modell med ett hölje, piezoelektrik kristall, backing layer samt matching layer. I rapporten ingår konstruktionsprocessen och testning av den konstruerade transducern samt analysering av påverkan av olika backing layers med varierande järnpulver/lim-förhållanden. Resultatet visar att det är fullt möjligt att producera en miniatyr transducer med syfte att kunna sända ut signaler samt registrera reflekterande ekon. Det som huvudsakligen begränsar storleken på transducern är brist på alternativ av verktyg och instrument för hantering av beståndsdelar i minimal storlek med hög precision. Resultatet visar även att backing layer med högre koncentration av järnpulver gav reducerade pulser i olika grader för samtliga signaler. / An ultrasound transducer is a well-known device within the medical industry. There are numerous types of transducers with varying traits. One common goal with transducers is diagnosing, treatment as well as monitoring of said treatment. The purpose of the project was to explore the boundaries for how small a transducer can be manufactured as well as how it performs. The transducer in question has a case containing a piezoelectric crystal, as well as a backing layer and a matching layer. Furthermore, this project is a continuation of a previous job done in spring of 2021. The purpose is to expand where the last project left off as well as improving the existent results. The report includes processes regarding construction and tests of the constructed transducer in question as well as analysis of the effect of different backing layers with varying iron powder/glue-relationships. The result demonstrates high possibility to producea miniature transducer with the purpose of emitting signals as well as registering returning echoes. The main limiting factor of the transducers size is the lack of options for tools and instruments for handling components with minimal size using high precision. The results further show that backing layers containing higher concentration of iron powder gave reduced pulses to different extents for all signals.

Syftet med studien var att undersöka behovet av stöd hos högstadieelever med hörselnedsättning som går integrerat i den ordinarie grundskolan. Jag har använt mig utav en kvantitativ enkätmetod samt en kvalitativ intervjumetod, där jag har genomfört tre telefonintervjuer innan utformningen av enkäten påbörjades. Resultatet av studien grundar sig på 18 enkätsvar, av 54 utskickade, samt tre telefonintervjuer med personer som har en hörselnedsättning och tidigare har gått integrerat i den ordinarie grundskolan. Resultatet visar att eleverna har ansträngande skoldagar till följd av att det krävs full koncentration för att höra vad klasskamraterna säger. För att de ska ha en chans att följa med i samtalen i klassrummen krävs en bra ljudmiljö, det är fyra elever som har uppgett att de inte kan följa med i samtalen. Med tanke på att många av eleverna går i stora klasser, vissa klasser har fler än 30 elever, kan jag förstå att drygt hälften av respondenterna har uppgett att de har ett behov av att få studera i ett enskilt rum för att få lugn och ro. De respondenter och informanter som har svarat att de brukar lämna klassrummet för till exempel träffa en hörselpedagog, har upplevt detta som positivt. En central fråga i denna studie är om eleverna har behov av stöd och vad stödet bestod av. Det är endast fyra elever som har uppgett att de är i behov av stöd. Fem elever har svarat att de får stöd, till exempel i form av hörselpedagogiskt stöd och specialpedagogiskt stöd.

This thesis deals with utilizing "the common ultrasonic parking sensors" for assisting the driver with backing-up a trailer. Key issues solved in this thesis are "Online trailer parameter estimation:" determining the estimate of angle between the car and the trailer, and determining the estimate of the length of the trailer shaft (distance from trailer coupling to trailer axle). Thesis contains the model of kinematics of the car with coupled trailer and ultrasonic sensor model together with the trailer viewd as an obstacle.

This thesis deals with utilizing "the common ultrasonic parking sensors" for assisting the driver with backing-up a trailer. Key issues solved in this thesis are "Online trailer parameter estimation:" determining the estimate of angle between the car and the trailer, and determining the estimate of the length of the trailer shaft (distance from trailer coupling to trailer axle). Thesis contains the model of kinematics of the car with coupled trailer and ultrasonic sensor model together with the trailer viewd as an obstacle.

The desire to incorporate multiple frequency bands of operation into personal communication devices has led to much research on reducing the size of antennas while maintaining adequate performance. GPS is one such application, where dual frequency operation, bandwidth and circular polarization pose major challenges when using traditional miniaturization techniques. Various loading methods have been studied to reduce the resonant frequency of the antenna – high permittivity dielectric loading, slot loading and cavity loading – while examining their effects on bandwidth and gain. The objective of this thesis is to provide guidelines on what is achievable using these miniaturization methods and insight into how to implement them effectively.

Les transducteurs ultrasonores capacitifs micro-usinés (CMUT) représentent aujourd’hui une réelle alternative aux technologies piézoélectriques dans le domaine de l’imagerie échographique médicale. Au cours des années, les procédés de fabrication des transducteurs se sont enrichis en vue d’améliorer leurs performances. A contrario le choix du substrat, généralement en silicium, a été peu étudié. Il est cependant reconnu que le support contribue à la signature acoustique du dispositif ultrasonore. L’objectif de ces travaux de thèse a été d’intégrer une couche de silicium poreux afin d’absorber une partie des ondes élastiques qui se propagent dans le substrat et interfèrent avec le signal acoustique émis. Nous montrons alors qu’il été possible de réaliser une couche de silicium poreux en face arrière de composants, sur plaquettes 6 pouces, sans dégrader leurs performances. Finalement, par l’intermédiaire de caractérisations acoustiques et des signatures impulsionnelles des transducteurs, nous révélons le potentiel prometteur de ce matériaux pour la réalisation de milieu arrière atténuant dédié à la transduction ultrasonore. / Capacitive micromachined ultrasonic transducers (CMUT) have emerged as a potential alternative to traditional piezoelectric transducers for ultrasound imaging. Along the years, CMUT processes have been evolved to enhance the device performances. In the meantime, no particular attention was paid on the silicon substrate, even if it is well-known that it could contribute to the transducer efficiency. The aim of this PhD thesis was to use porous silicon as a backing material for ultrasonic transducers to absorb a piece of the acoustic wave propagating in the substrate and which induce crosstalks in the acoustic signal. We show that porous silicon layer can be obtained on the rear side of already processed wafers without any damage on the performances of capacitive micromachined ultrasonic transducers. Finally, by means of acoustic characterizations and the transducer electroacoustic responses, we reveal the potential interest of porous silicon as backing material for ultrasonic transducers.

The aim of this work is to get the best detailed knowledge about hardness distribution in first 60 mm below the surface of backing roll. To this end, a method for obtaining multi-dimensional polynomial regression was developed and then a computer program for its processing was written.Way of finding suitable regression surfaces and their subsequent interpretation, is a pivotal part of this work.

This study compared simulated sales negotiations with authentic negotiations. Specifically, three areas of language were considered: (i) chat phases, (ii) mitigation in disagreements, and (iii) argumentation. Findings indicated that greatly reduced use of chat phases in the simulations led to an impoverishment of the interactional aspect of communication. A statistical analysis indicated that mitigation of disagreements was significantly reduced when compared to authentic negotiations. Finally, in spite of the difference noted between professional and non-professional negotiators in the simulated negotiations, a significant increase in the use of argumentation was found in the simulations. Even though further research would be required, it could be hypothesized that these differences may be attributed to the one-off nature of simulations, the absence of a surrounding business context and the intrinsic difficulty of using interactional language in simulations. These factors should be considered when simulations are used and designed for business and LSP training courses. / Linguistics and Modern Languages / M.A. (Linguistics)

In this age of wireless technology, Body Area networks (BAN) is revolutionising the concept of patient care and health monitoring. BAN provides people good assessment of their health status at any time, wherever they are physically. The increased interest in developing effective body (in, on & off) communication systems made phantoms which can mimic the electrical properties of an actual human body necessary. Wearable antennas which are the indispensable part of BAN got to be low pro file and above all influences that human body can make. There should also be a way to reduce the effect of antennas on human body namely specific absorption rate (SAR). In this work effort has been made to develop phantoms suitable for both On body and In body communications. The base materials which are selected for the study are of biological origin (bio ceramics and biopolymers) whose behaviour is closer to that of human tissues. As these phantoms are biocompatible they are essentially non toxic where the conventionally available phantoms are toxic in nature. Different kinds of low profile conformal wearable antennas working at 2.4GHz ISM band were developed and studied in the BAN perspective. Antennas suffer much in terms of matching and efficiency when they are in contact or in the premises of human body. This is a major hurdle in the way to setting up a good body communication network. This work encompasses various techniques adopted to limit the body interferences to an acceptable level. The techniques adopted (Such as Backing Ground Plane, High Impedance Surface & Polymeric Ferrite Sheets) proved to be effective in reducing the sway in antenna characteristics when they are mounted on body. Specific absorption rate is also brought to acceptable levels and thus avoiding the formation of hot spots due to microwave absorption. A safer and cost effective BAN can be set up using this work which will lead to a safer, mobile and healthy future. / Les réseaux BAN (Body Area Network) révolutionnent le concept de la surveillance et de la prise en charge à distance de la santé du patient. Le BAN fournit des informations sur l’état de santé du patient en temps réel quelque soit l’endroit où il se trouve. Dans le « télé monitoring », des capteurs de mouvement, de respiration ou du rythme cardiaque placés à l’intérieur ou sur le corps humain transmettent des données via le réseau sans fil constituant le BAN, une antenne étant associée à chaque nœud du réseau. La communication peut être in/on, on/on ou on/off selon que les antennes sont placées à l’intérieur, sur ou à l’extérieur du corps. Le développement des BAN nécessite la réalisation de modèles (ou fantômes) simulant au mieux les propriétés électromagnétiques du corps humain. Des antennes portables, miniaturisées doivent être réalisées avec des contraintes d’intégration d’une part (aux vêtements, à des objets type montre ou badge), des contraintes de résistance ou de prise en compte de l’influence du corps d’autre part. La réduction de l’impact des antennes sur les tissus en terme de SAR (Specific Absorption Rate) doit également être considérée. Dans ce travail, l’objectif est de développer des fantômes valables pour les communications dans et sur le corps. Les matériaux de base sélectionnés sont d’origine biologique (biocéramiques et biopolymères) avec des propriétés proches de celles des tissus humains. Ces fantômes étant biocompatibles, ils sont essentiellement non toxiques alors que les fantômes usuels le sont en général. D’autre part, différents types d’antennes conformables, fonctionnant dans la bande ISM 2.4 GHz ont été développées et étudiées dans la perspective du BAN. Les antennes voient leur adaptation et leur efficacité chuter au contact ou à proximité du corps, ce qui constitue un écueil majeur pour établir une bonne communication. Différentes méthodes permettant de réduire l’influence du corps (plan de masse à l’arrière, surface haute impédance, feuille de ferrite polymère) sont testés et leurs avantages et inconvénients développés. Des mesures de SAR permettent aussi de démontrer l’efficacité de ces méthodes sur la réduction de la puissance absorbée par les tissus. Au final, ce travail apporte une contribution à l’étude théorique et expérimentale de l’interaction entre corps humain et antenne dans le cadre des réseaux BAN appliqués à la télésurveillance de la santé.

This study compared simulated sales negotiations with authentic negotiations. Specifically, three areas of language were considered: (i) chat phases, (ii) mitigation in disagreements, and (iii) argumentation. Findings indicated that greatly reduced use of chat phases in the simulations led to an impoverishment of the interactional aspect of communication. A statistical analysis indicated that mitigation of disagreements was significantly reduced when compared to authentic negotiations. Finally, in spite of the difference noted between professional and non-professional negotiators in the simulated negotiations, a significant increase in the use of argumentation was found in the simulations. Even though further research would be required, it could be hypothesized that these differences may be attributed to the one-off nature of simulations, the absence of a surrounding business context and the intrinsic difficulty of using interactional language in simulations. These factors should be considered when simulations are used and designed for business and LSP training courses. / Linguistics and Modern Languages / M.A. (Linguistics)