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The selectivity and sensitivity of ion mobility spectrometry (IMS) to explosives was first demonstrated by Karasek in 1974.1 Airport security has always been a concern in the United States, especially since September 11th, 2001, and as a result IMS is commonly used to screen airline passengers and their luggage at all major airports. Portable IMS systems are now widely available for a variety of applications, but as the overall size of the IMS instrumentation decreases, the sensitivity typically decreases as well. A new ion detector read out technology, a capacitive trans-impedance amplifier (CTIA), coupled to a traditional Faraday plate has shown increased sensitivity over a Faraday plate read by a conventional current to voltage converter when used in mass spectrometry. Sandia National Laboratories sponsored a project to determine whether the CTIA technology could be coupled to an IMS, and to determine the potential increase in sensitivity that could be provided to a miniature IMS equipped with the new read out technology.Sandia first provided a full size IMS, a Phemto-Chem PCP-110, which was modified to support the first generation of CTIA (CTIA1). The CTIA1 was coupled to the IMS and was successfully used to detect explosives. Next, Sandia provided miniature IMS drift tubes, but incompatibilities necessitated the design of new miniature systems. At first, only the drift tube itself was redesigned, but eventually a complete miniature IMS, including the ionizer, circuitry, and read out, was designed and built. During the design phase a new ion-beam shutter capable of increased resolution was also implemented. The second generation of CTIA was coupled to a custom drift tube and the system demonstrated increased resolution and drastically increased sensitivity to the common explosives TNT and RDX when compared to the sensitivity of the system provided by Sandia. A custom miniature drift tube coupled to a CTIA will be placed into the peripheral equipment for Sandia's MicroHound II instrumentation to provide a portable IMS with sensitivity equal to or better than bench top IMS systems.

In this thesis, we introduce the fundamental operation of intra-body communications. The efficiency of the intra-body communications and the disturbance of intra-body communication are also studied. Intra-body communications propagate the signal by using the surface of human skin. Our study is mainly based on simulation. The accuracy of the simulation is verified by comparing with results in two papers. Then, five tissues are used to represent in the simulation. Firstly, we find design rules of transmitter and receiver for improving efficiency. The larger size of the circuit board is, the stronger signal receives. Length is more sensitivity than width but electrodes cannot be close. The signal does not vary widely with the location of the receiver. By setting proper parameters of skin, we can differentiate between wet skin and dry skin. Because the conductivity of wet skin is higher than dry one, the wet skin will give a stronger received signal. In the latter part of the thesis, we study the parameters cause the disturbance of intra-body communications. First, we study the effects of the person is close to the system. Second, we discuss the changes of the impedance of the system when another person touches the user. In the last, we discuss the variety of the receiving signal due to the bending of the arm, furthermore, we can distinguish the angles of the arm¡¦s bend from the coupling of electric field.

The measurement of vital signs is a risk-free, inexpensive, and reproducible clinical practice that enables identification of physiological deterioration of patients before an adverse event occurs. However, studies show that manual clinical measurements of respiratory rate are intermittent, biased, and inaccurate. Therefore, a contactless planar capacitive sensor was developed and evaluated against a clinical reference method. Results show that the sensor is accurate (i.e. strong agreement with an average ICC value of 0.99 and an average BSI coefficient of 2.76 < 4 breaths/min clinical threshold) and unbiased (i.e. average mean difference of -0.02 breaths/min). The sensor has promise for respiratory rate monitoring of bedridden patients even during shallow breathing. Future work includes addressing technology limitations, conducting a clinical pilot with a diverse patient population, and exploring potential in sleep quality assessment.

The measurement of vital signs is a risk-free, inexpensive, and reproducible clinical practice that enables identification of physiological deterioration of patients before an adverse event occurs. However, studies show that manual clinical measurements of respiratory rate are intermittent, biased, and inaccurate. Therefore, a contactless planar capacitive sensor was developed and evaluated against a clinical reference method. Results show that the sensor is accurate (i.e. strong agreement with an average ICC value of 0.99 and an average BSI coefficient of 2.76 < 4 breaths/min clinical threshold) and unbiased (i.e. average mean difference of -0.02 breaths/min). The sensor has promise for respiratory rate monitoring of bedridden patients even during shallow breathing. Future work includes addressing technology limitations, conducting a clinical pilot with a diverse patient population, and exploring potential in sleep quality assessment.

The objective of this study was to assess the performance of a capacitive sensor in measuring moisture content of cotton within the moisture range of 6-13%. The assessment was conducted in two phases: static and dynamic. During the static phase, models to predict moisture content were created and a 95% Confidence Interval of [-0.619,0.619], Percent Residual Accuracy of 97.586%, and a mean error of 4.396% were achieved. The Bland-Altman plot yielded a curve with a slight positive trend, suggesting the data could be modeled more appropriately by multiple models. The dynamic phase saw similar results as the static tests in overall trends, however the predicted values tended to be less accurate than static testing. Static testing had a RMSE of 0.313 compared to the dynamic testing having a RMSE of 0.737 [MC%]. Future work should increase the number of data points in the dynamic environment to improve these statistical markers.

The aim of this research was to develop an instrument that fills a niche in geophysical instrumentation for a tool that is fast, non-contact or minimal contact, and specifically optimised for discrete, near-surface, electrically resistive targets in resistive and conductive environments. This aim was sought to be achieved through the development of a new Capacitive Array Resistivity with Inductive Source (CARIS) system. Two CARIS systems were produced and thoroughly tested. A first prototype instrument CARIS-1, operating at 100KHz, was developed for proof of concept in the laboratory and initial field testing. A second prototype CARIS-2, operating at 5kHz, was developed for further fielding testing and trial mapping experiments. Several major conclusions have been reached through the development and testing of the CARIS systems. Firstly, the CARIS system can clearly detect objects in a conductive homogeneous liquid, with high repeatability of data. This result reinforced the concept of the CARIS method, and established the stability of the instrumentation in laboratory environments. The approach was validated by close correlation between measurements and modelling. Secondly, the CARIS system is able to measure responses to near-surface conductivity variation in field conditions with high repeatability. Data collected also showed spatial consistency with GPR, Resistivity and mapped culture. It was determined that properties of the near surface, such as moisture content and soil consolidation, can significantly affect the electrical homogeneity of the medium and thus the uniformity of the background reading. The CARIS systems thus had a limitation that they proved to be quite sensitive to variations of this nature. Thirdly, foll owing from the second conclusion, although the aim of the CARIS system was to detect the presence of discrete buried objects, CARIS proved to be more responsive to the effects of the burial process rather than the objects themselves. It was concluded therefore that the method of excavation, burial, and refill material were of high significance in CARIS interpretation. This conclusion was reinforced by the results of theoretical modelling which showed that shallow boundaries of small conductivity contrast could quite easily produce more significant anomalies than target objects which are deeper and have higher contrast.

What if the objects in the Museum of Islamic Art in Berlin could talk?All the artefacts are there for a reason. But especially in a historic exhibition on another culture those reason can be extremely difficult to see. Why look at a shagged old carpet? More than 4 million Muslims live in Germany today. Most people have very little background knowledge in Islamic art or history - but Islam is a regular topic of heated debate. People come to the Museum of Islamic Art with today´s questions, ideas and expectations. In today´s exhibition, visitors are flooded with impressions and information, but without background knowledge, it is difficult to relate things.  What are engaging, and information-rich, but not overwhelming formats to access deeper information on particular objects? How to explore their specific contexts as well as their relation to other objects?My final design - ‘Storytellers’ are guides. They are small tokens that represent objects from the museum. Each object has its own character, topic and relationships to other objects. It will show you through the exhibition on its` individual tour. There are tours with stories for children, families, different levels of background knowledge and interests.

A more energy efficient and sustainable method of desalinating water is needed due to increasing water shortages and contamination of current freshwater sources. Capacitive deionization (CDI), a new emerging technology, is a type of electric desalination that uses an applied voltage to pull the salt ions out of the salty solution and store the ions in porous carbon electrodes. CDI uses less applied energy than more commonly used methods of desalination like reverse osmosis and multi-flash distillation and has the added advantage of energy recovery. This report details experiments conducted to analyze the effect of different separation distances between the electrodes on salt ion adsorption for a high concentration solution under various flow rates and a 1 V voltage potential difference. The testing was performed in the Multiscale Thermal-Fluids Laboratory at The University of Texas at Austin using a uniquely fabricated CDI cell. Voltage, elapsed time, and electrical conductivity measurements were taken during the testing. Electrical conductivity was used to signify salinity of the solution. Two different separation distances were created by placing either one 2mm mesh between the electrodes or by using two 2 mm meshes between the electrodes. The results did not agree with the expectation that the one-mesh tests would adsorb twice the amount of salt ions as the two-mesh tests because of the differences in the electric field between the two types of tests. This is believed to be due to the high concentration tested. Future testing should include repeating these tests to verify the results and performing the tests for lower concentrations to see if they followed the expectation. / text

This thesis describes a finite element analysis (FEA) model of an indirect heating thermal actuator. The heat transfer mechanisms are investigated and the conductive heat transfer is found to be the dominant heat transfer mode. A model simplification method is discussed and used in the analysis to reduce the degrees of freedom and avoid meshing failures. The device is fabricated with the MetalMUMPs process. Measurements of the displacement as a function of the driving voltage are made to verify the FEA model. The results show that the simulation result of the FEA model produced a reasonable agreement with the experimental data. The difference between the FEA result and test result is investigated. A novel thermal actuator with integrated capacitive position sensor is also investigated. This new thermal actuator with an integrated capacitive sensor uses the indirect heating thermal actuator discussed in the first part of the thesis to achieve a new integration method. The displacement of the actuator provided by the sensor enables a feedback control capability. The analytical model, FEA and test results for the capacitive sensor are presented to validate the design concept. The test results show a reasonable agreement with the analytical analysis and the FEA. Finally, a manual displacement tuning application and a PI feedback control application with the designed thermal actuator with integrated capacitive sensor are documented. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2009-07-03 16:17:02.633