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- Genre: Doctoral Dissertation
Description
The accurate and fast determination of carbon dioxide (CO2) levels is critical for many health and environmental applications. For example, the analysis of CO2 levels in exhaled breath allows for the evaluation of systemic metabolism, perfusion, and ventilation, and provides the doctors and patients with a non-invasive and simple method to predict the presence and severity of asthma, and Chronic Obstructive Pulmonary Disease (COPD). Similarly, the monitoring of CO2 levels in the atmosphere allows for assessment of indoor air quality (IAQ) as the indoor CO2 levels have been proved to be associated with increased prevalence of certain mucous membrane and respiratory sick building syndrome (SBS) symptoms. A pocket-sized CO2 analyzer has been developed for real-time analysis of breath CO2 and environmental CO2. This CO2 analyzer is designed to comprise two key components including a fluidic system for efficient gas sample delivery and a colorimetric detection unit integrated into the fluidic system. The CO2 levels in the gas samples are determined by a disposable colorimetric sensor chip. The sensor chip is a novel composite based sensor that has been optimized to provide fast and reversible response to CO2 over a wide concentration range, covering the needs of both environmental and health applications. The sensor is immune to the presence of various interfering gases in ambient or expired air. The performance of the sensor in real-time breath-by-breath analysis has also been validated by a commercial CO2 detector. Furthermore, a 3D model was created to simulate fluid dynamics of breath and chemical reactions for CO2 assessment to achieve overall understanding of the breath CO2 detection process and further optimization of the device.
ContributorsZhao, Di (Author) / Forzani, Erica S (Thesis advisor) / Lin, Jerry Ys (Committee member) / Torres, Cesar (Committee member) / Tsow, Tsing (Committee member) / Xian, Xiaojun (Committee member) / Arizona State University (Publisher)
Created2014
Description
Monitoring of air pollutants is critical for many applications and studies. In
order to access air pollutants with high spatial and temporal resolutions, it is
necessary to develop an affordable, small size and weight, low power, high
sensitivity and selectivity, and wireless enable device that can provide real time
monitoring of air pollutants. Three different kind of such devices are presented, they
are targeting environmental pollutants such as volatile organic components (VOCs),
nitrogen dioxide (NO2) and ozone. These devices employ innovative detection
methods, such as quartz crystal tuning fork coated with molecularly imprinted
polymer and chemical reaction induced color change colorimetric sensing. These
portable devices are validated using the gold standards in the laboratory, and their
functionality and capability are proved during the field tests, make them great tools
for various air quality monitoring applications.
order to access air pollutants with high spatial and temporal resolutions, it is
necessary to develop an affordable, small size and weight, low power, high
sensitivity and selectivity, and wireless enable device that can provide real time
monitoring of air pollutants. Three different kind of such devices are presented, they
are targeting environmental pollutants such as volatile organic components (VOCs),
nitrogen dioxide (NO2) and ozone. These devices employ innovative detection
methods, such as quartz crystal tuning fork coated with molecularly imprinted
polymer and chemical reaction induced color change colorimetric sensing. These
portable devices are validated using the gold standards in the laboratory, and their
functionality and capability are proved during the field tests, make them great tools
for various air quality monitoring applications.
ContributorsChen, Cheng, Ph.D (Author) / Tao, Nongjian (Thesis advisor) / Kiaei, Sayfe (Committee member) / Zhang, Yanchao (Committee member) / Tsow, Tsing (Committee member) / Arizona State University (Publisher)
Created2014
Description
Small wireless cells have the potential to overcome bottlenecks in wireless access through the sharing of spectrum resources. A novel access backhaul network architecture based on a Smart Gateway (Sm-GW) between the small cell base stations, e.g., LTE eNBs, and the conventional backhaul gateways, e.g., LTE Servicing/Packet Gateways (S/P-GWs) has been introduced to address the bottleneck. The Sm-GW flexibly schedules uplink transmissions for the eNBs. Based on software defined networking (SDN) a management mechanism that allows multiple operator to flexibly inter-operate via multiple Sm-GWs with a multitude of small cells has been proposed. This dissertation also comprehensively survey the studies that examine the SDN paradigm in optical networks. Along with the PHY functional split improvements, the performance of Distributed Converged Cable Access Platform (DCCAP) in the cable architectures especially for the Remote-PHY and Remote-MACPHY nodes has been evaluated. In the PHY functional split, in addition to the re-use of infrastructure with a common FFT module for multiple technologies, a novel cross functional split interaction to cache the repetitive QAM symbols across time at the remote node to reduce the transmission rate requirement of the fronthaul link has been proposed.
ContributorsThyagaturu, Akhilesh Thyagaturu (Author) / Reisslein, Martin (Thesis advisor) / Seeling, Patrick (Committee member) / Zhang, Yanchao (Committee member) / Tepedelenlioğlu, Cihan (Committee member) / Arizona State University (Publisher)
Created2017