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The techniques of optoperforation, spectral characterization of alloy disorder, and metal-enhanced fluorescence were applied to previously unconsidered or disregarded systems in order to demonstrate that such applications are both feasible and consequential. These applications were the subject of three disparate works and, as such, are independently discussed. Despite being ostensibly restricted to mammalian cells, optoperforation was demonstrated in intact plant cells by means of successful femtosecond-laser-mediated infiltration of a membrane impermeable dextran-conjugated dye into cells of vital Arabidopsis seedling stems. By monitoring the rate of dye uptake, and the reaction of both CFP-expressing vacuoles and nanocellulose substrates, the intensity and exposure time of the perforating laser were adjusted to values that both preserved cell vitality and permitted the laser-assisted uptake of the fluorophore. By using these calibrated laser parameters, dye was injected and later observed in targeted cells after 72 hours, all without deleteriously affecting the vital functions of those cells. In the context of alloy disorder, photoluminescence of excitonic transitions in two InAsxP1-x alloys were studied through temperature and magnetic field strength dependencies, as well as compositionally-dependent time-resolved behavior. The spectral shape, behavior of the linewidths at high magnetic fields, and the divergence of the peak positions from band gap behavior at low temperatures indicated that alloy disorder exists in the x=0.40 composition while showing no considerable presence in the x=0.13 composition. The time-resolved photoluminescence spectrum for both compositions feature a fast and slow decay, with the slow decay lifetime in x=0.40 being longer than that of x=0.13, which may be due to carrier migration between localized exciton states in x=0.40. In order to achieve broadband metal-enhanced fluorescence in upconverting NaYF4:Yb,Er nanocrystals, two nanocomposite architectures were proposed that retrofit metallic nanoshells to these lanthanide-doped nanocrystals. The typical monometallic construction was rejected in favor of architectures featuring Au-Ag bimetallic concentric surfaces, a decision supported by the considerable overlap of the calculated plasmon modes of the metallic structures with the emission and absorption spectrum of the nanocrystals. Furthermore, precursors of these nanocomposites were synthesized and photoluminescence measurements were carried out, ultimately verifying that these precursors produce the requisite upconversion emissions. / Ph. D.

Plasmonic nanoparticles, specifically gold and silver nanoparticles, exhibit unique optical, physical, and chemical properties that are exploited in many biomedical applications. Due to their nanometer size, facile surface functionalization and enhanced optical performance, gold and silver nanoparticles can be used to investigate cellular biology. The work herein highlights a new methodology that has exploited these remarkable properties in order to probe various aspect of cancer cell biology, such as cell cycle progression, drug delivery, and cell death. Cell death mechanisms due to localized gold and silver nanoparticle exposure were also elucidated in this work. Chapter 1 introduces the reader to the synthesis and functionalization of gold and silver nanoparticles as well as reviews their implementation in biodiagnostic and therapeutic applications to provide a foundation for Chapters 3 and 4, where their use in spectroscopic and cytotoxic studies are presented. Chapter 2 provides the reader with detailed explanations of experimental protocols for nanoparticle synthesis and functionalization, in vitro cellular biology experiments, and live-cell Raman spectroscopy experiments that were utilized throughout Chapters 3 and 4. Chapter 3 presents the use of nuclear-targeted gold nanoparticles in conjunction with a Raman microscope modified to contain a live-cell imaging chamber to probe cancer cell cycle progression (Chapter 3.1), examine drug efficacy (Chapter 3.2), monitor drug delivery (Chapter 3.3), and detect apoptotic molecular events in real-time (Chapter 3.4). In Chapter 4, the intracellular effects of gold and silver nanoparticles are explored through live-cell Rayleigh imaging, cell cycle analysis and DNA damage (Chapter 4.1), as well as through the elucidation of cytotoxic cell death mechanisms after nanoparticle exposure (Chapter 4.2) and live cell imaging of silver nanoparticle treated cancer cell communities (Chapter 4.3).

Master of Science / Department of Electrical and Computer Engineering / William B. Kuhn / Q‐enhanced filtering technologies have been heavily researched, but have not yet been adopted into commercial designs due to tuning complexity, and performance issues such as noise figure and dynamic range. A multi‐pole Q‐enhanced band‐pass filter operating at 450 MHz with tunable bandwidth is developed in this thesis. A noise figure of 14 dB and dynamic range of 140 dB/Hz have been measured, making the filter suitable for operating in the IF subsystem of a radio receiver. The design utilizes off‐chip resonators, created using surface mount components or embedded passives in LTCC processes, to have a reasonably high base‐Q. The equivalent parallel loss resistance of the finite‐Q inductor and connected circuitry at resonance is partially offset by negative resistances, implemented with tunable on‐chip transconductors, as required to reach the needed Q for the targeted bandwidth. Each pole of the filter has binary weighted negative resistance cells for Q‐enhancement and binary weighted capacitances for frequency tuning. Binary weighted capacitive coupling cells allow the filter to achieve the level of coupling appropriate to the targeted bandwidth. To maintain the filter bandwidth, center frequency, and gain over environmental changes a realtime tuning algorithm is needed. A low complexity tuning algorithm has been implemented and found to accurately maintain the bandwidth, center frequency, and gain when operating at bandwidths of 10 or 20 MHz. Flatness of the pass‐band is also maintained, to within 0.5 dB across a temperature range of 25‐55 degrees C. In addition to the implementation of the tuning algorithm, the thesis provides a solution for pass‐band asymmetries spawned from the use of finite‐Q resonators and associated control circuitry.

This dissertation provides initial empirical evidence for Expectancy Value Theory for Help Sources and generates design recommendations for online courses based on the newfound understanding between theory and student behavior. My high-level research goals are pursued in the context of help seeking in the presence of reputation systems in MOOC discussion forums. Educational technology can be intentionally designed and introduced in such a way as to maintain the benefits of existing technology while reducing negative impact on learning-relevant behaviors. I do this through the lens of student expectancy and values for the help source, and costs of pursuing that help. Within this thesis I present three online survey experiments, one is intended to provide empirical evidence for the connection between Expectancy Value Theory for Help Sources and student help seeking outcomes. The remaining two survey experiments are designed to further investigate the results of a system for help exchange through the lens of Expectancy Value Theory for Help Sources. The first survey supports the existence of beliefs for help sources, although careful design of value manipulations is necessary to isolate value beliefs from expectancy beliefs for the help source. In a field experiment investigating the design of a help exchange system, I explore the connection between common reputation system features and Expectancy Value Theory for Help Sources. This provides support for the theory outside of a controlled laboratory setting. This Quick Helper MOOC Experiment and the supporting Quick Helper Theory Survey Experiment show that voting within a reputation system context decreases the number of peers invited to be helpers possibly through an increase in evaluation anxiety. Help giver badges ca reduce this evaluation anxiety and mitigate the negative impact of voting. I performed a final field experiment in a small private online course to examine these issues in a more naturalistic setting outside of the Quick Helper help exchange system. I explored learning expectancy-emphasizing email prompts and voting in the course discussion forum, and how these manipulations impacted larger, more nuanced dependent variables such as help seeking and learning. Results from this experiment are not as strong as the more tightly controlled survey experiments and Quick Helper MOOC field experiment, but we still see support in the general direction of our original hypotheses. From these experiments I generate a series of design recommendations for instructors of online courses implementing discussion forums: (1) reputation systems can have a positive effect on student engagement in discussion forums, but there may be a negative effect on help seeking and other vulnerable learning-relevant behaviors, (2) The negative impact of evaluation anxiety from voting can be mitigated through the use of either help giver badges or using only upvoting instead of up/downvoting which may reduce evaluation anxiety, and (4) Email prompts with dilute implementation have questionable impact on student contributions in discussion forums.

ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / In a quest to provide networked communication to test assets at all of the Major Range and Test Facility Bases (MRTFB), the integrated Network Enhanced Telemetry (iNET) Program was formed. A study was accomplished outlining five environments that encompass the work of these MRTFBs. The first of these environments to be advanced towards networked communication is the Aeronautical Environment. In order to develop these technologies, a test platform is proposed, realized, and tested. This airborne test platform will be used for concept and product testing and validation of the three portions of the Telemetry Network System (TmNS); the vehicle network, vNET, the radio frequency network (RF), rfNET, and the interface to the ground network, gNET. This paper will present the baseline system configuration, describe its operation, and detail RF link testing results.

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / A previous paper was presented detailing the design and testing of the first networked demonstration system (ITC 2006) for iNET. This paper extends that work by testing a commercial off the shelf (COTS) solution for the wireless network connection of the Telemetry Network System (TmNS). This paper will briefly discuss specific pieces of the airborne and ground station system but will concentrate on the new wireless network link, how it was tested, and how well it performed. Flight testing results will be presented accessing the performance of the wireless network link.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper baselines the performance of common, single band telemetry blade antennas in two telemetry bands and compares that performance to two very differing multi-band antenna designs. A description of each antenna is presented followed by flight testing results and conclusions. Results are in the form of received signal strength versus geographic location, derived in-flight antenna patterns, link availability, and bit error analysis.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper discusses the methodology, requirements, tests, and implementation plan for the live demonstration of the Enhanced Flight Termination System (EFTS) using a missile program at two locations in Florida: Eglin Air Force Base (AFB) and Tyndall AFB. The demonstration included the integration of EFTS Flight Termination Receivers (FTRs) onto the missile and the integration of EFTS-program-developed transmitter assets with the mission control system at Eglin and Tyndall AFBs. The initial test stages included ground testing and captive-carry flights, followed by a launch in which EFTS was designated as the primary flight termination system for the launch.

Since the innovation of computers some 40 years ago and the introduction of microcomputers in 1975, computers are playing an active role in education processes and altering the pattern of interaction between teacher and student in the classroom. Computer assisted learning has been seen as a revolution in education. In this research, the author has studied the impact of using microcomputers on mathematical education, particularly at the Hong Kong tertiary level, in different perspectives. Two computer software packages have been developed on the microcomputer. The consideration of the topic to be used in the computer assisted learning was arrived at in earlier surveys with students who thought that computers could give very accurate solutions to calculations. The two software packages, demonstrating on the spot the error that would be incurred by the computer, have been used by the students. They are both interactive and make use of the advantages of the microcomputer's functions over other teaching media, such as graphics facility and random number generator, to draw to the students' attention awareness of errors that may be obtained using computers in numerical solutions. Much emphasis is put on the significance and effectiveness of using computer packages in learning and teaching. Measurements are based on questionnaires, conversations with students, and tests on content material after the packages have been used. Feedback and subjective opinion of using computers in mathematical education have also been obtained from both students and other teachers. The research then attempts to examine the suitability of applying computer assisted learning in Hong Kong education sectors. Some studies on the comments made by students who participated in the learning process are undertaken. The successes and failures in terms of student accomplishment and interest in the subject area as a result of using a software package is described. Suggestions and recommendations are given in the concluding chapter.