Yes / In this paper, a 2.45 GHz band microwave sensor design is introduced to be utilized for the dielectric constant determination of ethanol-water solutions. The introduced microwave sensor is composed of two symmetrically positioned, directly coupled inter-connected split-ring resonators with a circular ring-shaped detection area in the middle region, into which a small amount of ethanol-water solution is dropped. The fabricated prototype of the microwave sensor has a total component size of 12 mm x 30 mm on Rogers RO4003 substrate. The sensor measurement performance is numerically evaluated and experimentally validated in good agreement. The introduced microwave sensor has the structural design novelty of possessing the main detection region in a form of a circular hollow where a disposable 3D printed fluid cup can be accommodated for multiple uses. The introduced microwave sensor has technical feasibility to be used as an ingredient identification device for the chemical solutions to figure out complex dielectric parameters of ethanol-water specimens with small, low-cost, reusable, easy-to-fabricate features as well as the determination of volume percentage concentration of ethanol content.

This study investigates the manifestation of geometric features of turbine blades in signatures of non-optical time of arrival (ToA) probes. The approach enables an evaluation of the various signal characteristics used for defining ToA for a range of airfoil geometries and provides knowledge about additional waveform characteristics. The objective of this research is to increase the accuracy of microwave ToA probes by gaining a better understanding of the microwave signals in five steps. Firstly, ToA definitions used in the past are compared. Considering accuracy, computational effort, and versatility, the constant fraction crossing definition is found to be the most accurate. Secondly, an experimental apparatus capable of measuring airfoil ToA with microwave probes and optical probes as a reference is designed and built. As a third step, a catalog of 16 turbine blade geometries is developed. Fourthly, the signatures of these turbine blades are acquired using both the optical and the microwave probes. Finally, the impact of the geometric effects on the signatures is evaluated. The quality of the microwave results is found to be highly dependent on the polarization of the microwaves. Analysis of the time domain signal shows that decreasing the blade width, increasing the chord angle, or incorporating a blade tip pocket or a varying cross-section leads to a decrease in the amplitude of the peak caused by the blade. Increasing the blade width and incorporating a chord angle leads to an increase in peak width. A frequency domain analysis is conducted on the microwave signals and verified using a synthetic signal. This analysis confirms the findings from the time domain analysis. The time domain analysis of the laser measurements shows that the spatial resolution of the laser is much higher than that of the microwave sensor. Consequently, the signal acquired with the optical setup provides a good means of defining the blade ToA. The knowledge gained in this study about the sensor and its interaction with passing blade tips of varying geometry can be used to enhance the understanding of microwave ToA measurements. This knowledge provides further insight into airfoil and engine health.

Traumatic brain injuries (TBIs) are a major public health problem worldwide where the symptoms can be anything from mild concussion to severe swelling of the brain tissue. As a result of TBI the intracranial pressure (ICP) can elevate to pathological levels with severe consequences such as hypoxia, ischemia and brain hemorrhage. TBI and the subsequent ICP increase could hence lead to disability or in worst cases death. Therefore to understand the severity of a head injury and the path regarding further treatments, monitoring of a patient's ICP is crucial in the intensive care units (ICU) environment. Invasive methods of ICP monitoring are at this present date the standard in ICU because of the accuracy when compared to non-invasive methods. All invasive ICP monitoring methods come with a risk to the patient and require the presence of a neurosurgeon. The thesis's objective was to develop a gradually increasing ICP testbed for a new non-invasive microwave based skin patch sensor. The aim with this project was to verify if a dependence in the resonance characteristic of the NASA SansEC microwave sensor with respect to ICP exists as suggested by previous works in a novel testbed and to provide a correlation model based on the testbed experiment. The developed testbed simulate increasing ICP by increasing volume of an artificial cerebro-spinal fluid (aCSF) liquid, a liquid emulating the CSF. The microwave sensor's resonance frequency is due to the permittivity changes caused by the change (increasing) in the fluid volume, which for this setup is directly correlated to the pressure change as well. Trials with different aCSF samples were made to ensure that the used aCSF in the testbed had the same dielectric properties as human CSF. The developed testbed had a simple structure made with several plastic containers of rectangular shape which were found to be well suited for the purpose of the experiment. For the microwave sensor trials an Fieldfox microwave analyzer was used and the sensor was evaluated around 1 - 4 GHz. The testbed pressure was increasing from 0 - 47 mmHg covering most useful ICP ranges. Larger pressures were also possible but limited by the height of the work room and the increase of complexity in the testbed design. The results from the trials showed a total resonance frequency shift of 76 MHz from 4 - 30 mmHg with an linear correlation of R2 = 0,91. The sensor measurements above 30 mmHg showed a saturation where the first principal frequencies were stable at 1,368 GHz. The linear relationship obtained for 4-30 mmHg is a reassurance that the Nasa SansEC sensor should be studied further. Future work should include new trials with modifications to the testbed setup and sensor design.

Este trabalho destina-se a especificar, analisar e ensaiar um sensor de presença para um semáforo inteligente de baixo custo. O sensor tem por finalidade a redução dos custos de implantação e manutenção nos sistemas de controles dos semáforos inteligentes, quando comparado a outros sensores, tais como, por imagem, ultrassom, laser, infravermelho, pneumático ou indutivo. O princípio de funcionamento tem por base a detecção de veículos na região de aproximação das vias de uma interseção por meio de um sensor que gera um sinal elétrico para o sistema de controle de tráfego. Utilizando sensores de micro-ondas de efeito Doppler e um circuito detecção o sistema torna-se de fácil implantação nos cruzamentos das vias públicas, por possuir tamanho reduzido, facilidade de programação e baixo consumo de energia, atendendo, portanto a necessidade de sistemas sustentáveis. Por motivo de segurança, ao ser iniciado ou reiniciado devido a falta de energia elétrica, o sistema funciona de forma temporizada por dois ciclos completos, tempo suficiente para que seja possível a detecção de veículos pelos sensores. / This work aims to specify, analyze and test a presence sensor for an intelligent traffic light at low cost. The sensor is intended to reduce the costs of deployment and maintenance of control systems in intelligent traffic lights, when compared to other sensors such as imaging, ultrasound, laser, infrared, pneumatic or inductive. The operating principle is based on the detection of approaching vehicles in the region of an intersection roads by means of a sensor which generates an electrical signal to the control system traffic. Using sensors microwave Doppler Effect and a loop detection system becomes easy to deploy in the crossings of public roads, for having reduced size, ease of programming and low power consumption, light, therefore the need for sustainable systems. For security reasons, to be started or restarted due to power outages, the system works timed by two complete cycles, enough time to be able to detect vehicles by sensors.

Depuis la révolution industrielle les niveaux des concentrations atmosphériques des gaz à effet de serre ne cessent d’augmenter provocant ainsi une accélération du réchauffement climatique. Les composés organiques volatils (COVs) contribuent non seulement à cet effet de serre mais aussi à la pollution environnementale qui a un impact négatif sur toutes les espèces vivantes de la planète. Par exemple, au cours de l’année 2012, la pollution de l'air a été à l’origine 7 millions de décès, selon l'Organisation mondiale de la santé (OMS) [1]. Très récemment, une étude médicale de la commission Lancet sur la pollution et la santé a révélé qu'en 2015 un décès sur six était lié à la pollution de l'air et de l'eau, 6,5 millions de décès dans le monde chaque année sont liés à la pollution de l'air intérieur et extérieur [2]. En effet, les COVs, très volatils et utilisés comme solvants par exemple, peuvent être indirectement à l’origine de toux, d’inconfort thoracique, de gêne douloureuse, d’essoufflement respiratoire, d’irritation nasale ou oculaire ou encore de la gorge. Ils peuvent aussi être directement toxiques ou explosifs ou encore perturbateurs de la réponse immunitaire. De plus certains d’entre eux sont classés CMR (cancérogène, mutagène et reprotoxique). Dans ces conditions une meilleure connaissance des effets liés à l’exposition aux COVs sur la santé et l’environnement est vraiment nécessaire. Cette connaissance passe également par la détection et la quantification des concentrations de COVs afin de proposer un meilleur aménagement des environnements et d'alerter les individus concernés en temps réel sur les dangers encourus. La plupart des plateformes déjà existantes ou commercialisées sont soient trop coûteuses, soient très consommatrices d'énergie, soient fonctionnelles à des températures élevées, soient instables pour la détection en temps réel ou à long terme ce qui limite la prolifération des sites de mesures. Ainsi, cette thèse s’inscrit dans le domaine des capteurs de gaz dédiés pour la détection de la pollution dans l’air. Elle porte sur le développement d’une plateforme de détection, de suivi et de quantification des composés organiques volatils (COVs) en temps réel, utilisant un capteur de gaz différentiel flexible et imprimé basé sur des transducteurs micro-ondes et des matériaux carbonés polymères composites comme couches sensibles. Le dispositif proposé vise à fournir des informations directement exploitables pour constituer à terme une plateforme de faible coût embarquée, dédiée à l’internet des objets pour faciliter la prolifération des sites de détection et de contrôle en réalisant des réseaux de capteurs communicants sans fil fonctionnant en environnements variés. / Since the Industrial Revolution, the levels of atmospheric concentrations of greenhouse gases have been increasing, causing an acceleration of global warming. Volatile organic compounds (VOCs) contribute not only to this greenhouse effect, but also to environmental pollution, which has a negative impact on all living species on the planet. For example, in the year 2012, air pollution caused 7 million deaths, according to the World Health Organization (WHO) [1]. In addition, a very recent medical study by the Lancet Commission on Pollution and Health found that one in six deaths in 2015 was related to air and water pollution [2]. Also, indoor and outdoor air pollution is linked to 6.5 million deaths worldwide each year. VOCs can indirectly cause cough, chest discomfort, painful discomfort, shortness of breath, as well as nasal, ocular or throat irritation. They can also be directly toxic or explosive or disruptive of the immune response. In addition, some of them are classified as CMR (carcinogenic, mutagenic and reprotoxic). They are very volatile and often used as solvents for example. In these conditions, a better understanding of the health and environmental effects of exposure to VOCs is necessary. Such knowledge also involves the detection and quantification of VOC concentrations in order to propose a better management of the environments and to alert people in real time of the dangers incurred. Most of the existing or commercially available platforms are either too expensive, energy intensive, high temperature functional, unstable for real-time or long-term detection, which limits the proliferation of measurement sites. This thesis is in the field of dedicated gas sensors for the detection of pollution in the air. It deals with the development of a platform for the detection, monitoring and quantification of volatile organic compounds (VOCs) in real time, using a flexible and printed differential gas sensor based on microwave transducers and composite polymeric carbon materials as sensitive layers. The proposed device aims at providing directly exploitable information such as a low-cost embedded platform dedicated to the Internet of things and which offers increasing possibilities for the proliferation of detection and control sites by realizing networks of wireless communicating sensors operating in various environments.

Fine-powdered bulk materials exhibit high compressibility even under low pressure. The dosing error in volumetric dosing devices increases fundamentally with increasing product compressibility. In order to increase the dosing accuracy of a volumetric dosing of powdered bulk solids, the dosing process must be adapted to the product parameters. The most important parameter is the time-variable product density. With a pure volumetric dosage, it has a direct influence on the actually filled product quantity. Attempts are often made to obtain feedback by means of a scale in order to continuously adjust the volume. However, this is often associated with a delay. In this article, the approach is to measure the product mass flow directly by means of a microwave sensor and to regulate it to a predetermined mass flow. The experimental investigations were carried out with a screw dosing device FVS 3111. Two scenarios were tested: on the one hand, the integration of the sensor directly at the product delivery point, whereby the difference of the average value of the dosed quantity to the target weight could be improved with the sample product coffee; on the other, the sensor was integrated directly at the beginning of the screw and the remaining product flow was simulated. A reduction of the standard deviation compared with the conventional control could also be achieved, but here, the difference between the average of the dosed quantity and the nominal quantity is greater. The cause is presumed to be the too generalized assumption of product behaviour in the case of vertical conveying by means of a screw. In summary, the dosing accuracy of a screw dosing device could be increased by measuring and regulating the mass flow and thus the costs of a manufactured packaging could be reduced.