En el presente trabajo se han diseñado, construido y evaluado dos fluorosensores miniaturizados y portátiles, que pueden representar una alternativa a la instrumentación analítica clásica de elevado coste, gran tamaño y elevado consumo de reactivos, que necesita de mantenimiento y de personal especializado para su utilización. El empleo de fluorescencia representa intrínsecamente una ventaja en términos de sensibilidad y minimización de interferencias, ya que existen muy pocas moléculas que sean fluorescentes, y menos aún en la zona vis-NIR del espectro electromagnético. Asimismo, los dos dispositivos desarrollados presentan una gran versatilidad para su posible uso en la detección de diversos analitos en función del optodo seleccionado. Los optodos empleados en los dispositivos desarrollados incluyen cromo(fluoro)ionóforos que han sido diseñados, sintetizados y caracterizados en el presente trabajo para operar con la instrumentación miniaturizada y de bajo coste disponible. Se han diseñado, sintetizado y caracterizado nuevos colorantes cianina (croconinas, cetocianinas y (nor)cianinas-anilinas) para su utilización como cromo(fluoro)ionóforos en optodos, tanto en medidas basadas en absorbancia como en fluorescencia.El primer dispositivo opera integrado como detector en un sistema de análisis por inyección de flujo continuo (FIA), y tanto con un optodo selectivo a potasio, como con uno selectivo a plomo, ha mostrado unas apropiadas características analíticas. Su utilización en la determinación de potasio en muestras dopadas de agua potable de red y de plomo en extractos de suelos contaminados ha demostrado su aplicabilidad en muestras reales. El segundo dispositivo consiste en una sonda más portátil y manejable y en la que la intercambiabilidad de la membrana es más fácil, para realizar medidas in-situ y en discontinuo. Ésta se ha activado químicamente con un optodo selectivo a plomo y ha mostrado adecuadas propiedades analíticas de respuesta. Finalmente, se ha aplicado a la determinación de plomo en muestras naturales, verificándose su buen funcionamiento. / In this study two miniaturized and portable fluorosensors were designed, constructed and evaluated. These sensors represent an alternative to classical analytical instrumentation which can be expensive, bulky and reagent dependent, not to mention the need for specialized technicians for its use and maintenance. The use of fluorescence represents an intrinsic advantage with regard to sensibility and interference minimization, since few fluorescent molecules exist in the vis-NIR region of the electromagnetic spectrum. These devices are also versatile; depending on the selected optode they can be used in the detection of diverse analytes. The optodes employed in these devices include chromo(fluoro)iononophores and were designed, synthesized and characterized in this study to operate with miniaturized and low-cost instrumentation. New cyanine dyes (croconines, ketocyanines and (nor)cyanine-anilines) were designed, synthesized and characterized for use as chromo(fluoro)iononophores in optodes for absorbance-based measurements as well as for fluorescence-based measurements. The first device operates as an integrated detector in a continuous flow injection analysis (FIA) system and showed excellent analytical performance with a potassium-selective optode, as well as with a lead-selective one. Its use in the determination of potassium in doped potable water samples, and of lead in contaminated soil extracts, demonstrates its applicability to natural samples. The second device consists of a more portable and user-friendly dip-probe which facilitates the interchangeability of the membrane when in-situ and continuous measurements are carried out. The dip-probe device was chemically activated with a lead-selective optode and also demonstrated good analytical response properties.Finally, this second device was applied to lead determination in natural samples, resulting in positive verifiable performance.

No description available.

No description available.

This thesis has been divided into two essential parts, the purpose of the first part is to investigate and explore a three-tier architecture for remote health monitoring system capable to collect, store and forward the physiological data, which has been collected by a mobile device via a bluetooth connection from body sensors, to an internet data base server. During the second part, we have tried to take a deep look into a heart beat modeling method. We have studied and investigated on extended integral pulse frequency modulation model which is used for the presence of ectopic beats and heart rate turbulence.

As wireless devices are becoming more powerful, more flexible and less costly to produce, they are often being applied in new ways. Combining wireless technology with new types of sensors results in the ability to monitor and control the environment in ways not previously possible. For example, an intelligent wireless sensor system that consists of a sensor, digital processor and a transceiver can be mounted on a board the size of a coin. The data collected by these devices are then transmitted to a central unit which is able to thoroughly process and store this data. Not only can the central processing station provide reports about certain physical parameters in the environment, it can also control the environment and other parameters of interest. The design process of these wireless sensor platforms is a well-developed area of research that covers concepts like networking, circuit design, Radio-Frequency (RF) circuits and antenna design. The design of a wireless sensor can be as simple as putting together a microcontroller, a transceiver and a sensor chip or as complicated as implementing all the necessary circuitry into a single integrated circuit. One of the main applications of the sensors is in a control loop which controls physical characteristics in an environment. Specifically, if the objective of a control system is to limit the amount of vibrations in a structure, vibration sensors such as accelerometers are usually used. In environments where the use of wires is costly or impossible, it makes sense to use wireless accelerometers instead. Among the numerous applications that can use such devices are the automotive and medical vibration control systems. In the automotive industry it is desirable to reduce the amount of vibrations in the vehicle felt by the passengers. These vibrations can originate from the engine or the uneven road, but they are damped using passive mechanical elements like rubber, springs and shocks. It is possible however, to have a more effective vibration suppression using active sensor-actuator systems. Since adding and maintaining wires in a vehicle is costly, a wireless accelerometer can be put to good use there. A medical application for wireless accelerometers can be used with a procedure called Deep Brain Stimulation (DBS). DBS is a relatively new and very effective treatment for advanced Parkinson’s disease. The purpose of DBS is to reduce tremors in the patients. In DBS a set of voltages is applied to the brain of the patient as some optimum combinations of voltages will have a very positive effect on the tremors. Those optimum voltages are currently found by trial and error while a doctor is observing the patient for tremors. Wireless accelerometers with the use of a computer algorithm can assist in this process by finding the optimum voltages using the feedback provided by the accelerometers. The algorithm will assist the doctor in making decisions and has the potential of finding the optimums completely on its own.

Interlocking Concrete Pavements also known as block pavements are one of the integral parts of the pavement system in Europe. The use of ICP slowly extended to other countries including North America. As the usage increased the need for more scientific research was developed which resulted in the study of ICP design and analysis methods, construction practices and materials specifications. This thesis presents a research project involving the design, construction, instrumentation, performance modeling and other field tests of eight ICP crosswalks with four different design assemblies. The research projects were constructed at the Centre for Pavement and Transportation Technology (CPATT) Test Track and at the University of Waterloo Ring Road. Each of the test sections is instrumented with structural and environmental sensors of sensors to monitor the pavement performance under heavy truck traffic, typical municipal loadings and to quantify environmental effects. A database is generated and the measured stress, strain, temperature and moisture measurements are analysed to evaluate the expected long-term performance of the structural components of ICP crosswalk designs.

In this work, a new electrochemical detection method was developed with the ability to determine a wide range of inorganic and organic species at, trace levels. In brief, the detection method takes advantage of all possible electrochemical reactions that may occur during scanning of the electrode potential. Changes in the detector response are mainly the result of inhibition of oxygen adsorption and hydrogen adsorption, alteration of electrical properties of the double layer, or redox processes of the adsorbate. Various electrochemical techniques were examined in the measurements; i.e. cyclic voltammetry, pulse amperometric detection, and square wave voltammetry. In those electrochemical techniques, the detection was carried out in a stripping mode after accumulation of analytes on the electrode surface. The smallest discernable signal is associated with about 0.1% surface coverage, which corresponds to the adsorption of about 10-18 mol of analyte on a ultramicroelectrode 5-[mu]m in radius. The response time of the detector to the concentration change in most cases is less than 1s. Electrochemical conditioning of the working electrode is sufficient to ensure a stable response for a period of several hours. It appears that square wave and cyclic voltammetry techniques are more suitable for the detection method. The linear dynamic range of the calibration curve depends on the characteristic of the analyte-electrode bond and redox processes of the analyte, which may occur at the electrode surface. For instance, for strongly adsorbing molecules the linear dynamic range extends over two orders of magnitude from about 10 -7 M to 10-5 M and for electroactive compounds from about 10-8 M to 10-4 M. In general, the relative standard deviation for replicate determinations was lower than 5%. Moreover, in these analyses, removal of oxygen from the analyzed solutions is not required.

<p>Localization is projected to play a critical role in mobile computing applications. Nevertheless, the state of the art is inadequate especially when operating on mobile devices. More specifically, the on-phone GPS sensor has an unacceptable energy consumption and does not operate indoors. Alternate localization techniques, based on WiFi or GSM, alleviate some of the GPS limitations but provide degraded accuracy and assume pre-installed infrastructure. As a result, these solutions need extensive war-driving for collecting location fingerprints and, in many instances, limit services to regions close to drivable paths. Moreover, when infrastructure is scarce or missing, the localization accuracy is poor. Lastly, relying on hardware deployments is costly and raises scalability concerns when targeting wide regions.</p><p>To address the shortcomings of current solutions, we propose four new localization systems: (1) CompAcc enables energy-efficient, war-driving-free localization using the phone inertial sensors and digital maps, (2) Escort provides indoor localization by exploiting the phone inertial sensors and social environments where people are mobile, (3) SurroundSense enables indoor logical localization (e.g., inside Target) by sensing the user ambiance through the phone sensors, and (4) EnLoc proposes energy-efficient localization via personalized mobility profiling and predictions.</p> / Dissertation

For centuries scientific ingenuity and innovation have been influenced by Mother Natures perfect design. One of her more elusive designs is that of the sensory olfactory system, an array of highly sensitive receptors responsible for chemical vapor recognition. In the animal kingdom this ability is magnified among canines where ppt (parts per trillion) sensitivity values have been reported. Today, detection dogs are considered an essential part of the US drug and explosives detection schemes. However, growing concerns about their susceptibility to extraneous odors have inspired the development of highly sensitive analytical detection tools or biosensors known as electronic noses. In general, biosensors are distinguished from chemical sensors in that they use an entity of biological origin (e.g. antibody, cell, enzyme) immobilized onto a surface as the chemically-sensitive film on the device. The colloquial view is that the term biosensors refers to devices which detect the presence of entities of biological origin, such as proteins or single-stranded DNA and that this detection must take place in a liquid. Our biosensor utilizes biomolecules, specifically IgG monoclonal antibodies, to achieve molecular recognition of relatively small molecules in the vapor phase.

The object of this thesis research is to facilitate the appraisal and analysis of the signatures of the modern acoustic wave biosensors, as well as to improve the experimental methodology to enhance sensor performance. For this purpose, both theoretical characterization of acoustic wave sensor signatures and experimental studies for the most frequently used acoustic wave biosensors, the liquid phase QCM (quartz crystal microbalance) and the vapor phase SAW (surface acoustic wave) sensors, are presented. For the study of SAW vapor phase detection, the author fabricated different types of two-port SAW resonator sensors on quartz substrates and designed and performed a significant number of detection experiments. These were conducted both with calibrated or known target samples under laboratory conditions at Georgia Tech Hunt Lab and with samples of unknown concentrations such as seized crack cocaine (courtesy of Georgia Bureau of Investigation, GBI) to see the sensors capability to work in the field conditions. In addition, the dependence of the SAW sensor signatures on specific locations of the surface perturbation was investigated to account for some observed abnormal responses. Finally, a novel approach to classify and visualize chemically analogous substances is introduced. The author expects that the thesis work herein may contribute to the study of the modern acoustic wave biosensors which includes but is not limited to: the establishment of underpinning theory that will aid in the evaluation of the signatures; the practical aspects of design and fabrication of SAW devices specific to the vapor phase immunoassay; the development of efficient experimental methodologies; the strategic immobilization of a biolayer on SAW resonator based biosensors; and, the acquisition of reference data for the development of commercial acoustic wave sensors.