Advanced sensors technology survey

This project assesses the state-of-the-art in advanced or 'smart' sensors technology for NASA Life Sciences research applications with an emphasis on those sensors with potential applications on the space station freedom (SSF). The objectives are: (1) to conduct literature reviews on relevant advanced sensor technology; (2) to interview various scientists and engineers in industry, academia, and government who are knowledgeable on this topic; (3) to provide viewpoints and opinions regarding the potential applications of this technology on the SSF; and (4) to provide summary charts of relevant technologies and centers where these technologies are being developed

Energy Efficiency in Communications and Networks

The topic of "Energy Efficiency in Communications and Networks" attracts growing attention due to economical and environmental reasons. The amount of power consumed by information and communication technologies (ICT) is rapidly increasing, as well as the energy bill of service providers. According to a number of studies, ICT alone is responsible for a percentage which varies from 2% to 10% of the world power consumption. Thus, driving rising cost and sustainability concerns about the energy footprint of the IT infrastructure. Energy-efficiency is an aspect that until recently was only considered for battery driven devices. Today we see energy-efficiency becoming a pervasive issue that will need to be considered in all technology areas from device technology to systems management. This book is seeking to provide a compilation of novel research contributions on hardware design, architectures, protocols and algorithms that will improve the energy efficiency of communication devices and networks and lead to a more energy proportional technology infrastructure

Validation of Nanosecond Pulse Cancellation Using a Quadrupole Exposure System

Nanosecond pulsed electric fields (nsPEFs) offer a plethora of opportunities for developing integrative technologies as complements or alternatives to traditional medicine. Studies on the biological effects of nsPEFs in vitro and in vivo have revealed unique characteristics that suggest the potential for minimized risk of complications in patients, such as the ability of unipolar nsEPs to create permanent or transient pores in cell membranes that trigger localized lethal or non-lethal outcomes without consequential heating. A more recent finding was that such responses could be diminished by applying a bipolar pulse instead, a phenomenon dubbed bipolar cancellation, paving the way for greater flexibility in nsPEF application design. Transitioning nsPEFs into practical use, however, has been hampered by both device design optimization and the intricacies of mammalian biology. Generating electric fields capable of beneficially manipulating human physiology requires high-voltage electrical pulses of nanosecond duration (nsEPs) with high repetition rates, but pulse generator and electrode design in addition to the complex electrical properties of biological fluids and tissues dictate the strength range and distribution of the resulting electric field. Faced with both promising and challenging aspects to producing a biomedically viable option for inducing a desired nsPEF response that is both focused and minimally invasive, the question becomes: how can the distinct features of unipolar and bipolar nsPEF bioeffects be exploited in a complex electrode exposure system to spatially modulate cell permeabilization? This dissertation presents a systematic study of an efficient coplanar quadrupole electrode nsPEF delivery system that exploits unique differences between unipolar and bipolar nsPEF effects to validate its ability to control cell responses to nsPEFs in space. Four specific aims were established to answer the research question, with specific attention to the roles played by pulse polarity, grounding configuration and electric field magnitude in influencing nsPEF stimulation of electropermeabilization in space. Using a prototype wire electrode applicator charged by a custom-built multimodal pulse generator, the aims were to spatially quantifyelectropermeabilization due (1) unipolar and (2) bipolar nsPEF exposure, to (3) apply synchronized pulses with a view to canceling bipolar cancellation (CANCAN) through superposition that could shift the effective nsPEF response, and to (4) evaluate the ability of the quadrupole system to facilitate remote nsPEF electropermeabilization. Numerical simulations were employed to approximate the nsPEF distribution for a two-dimensional (2-D) area resulting from unipolar, bipolar or CANCAN exposure in a varied-pulse quadrupole electrode configuration. For all experiments, the independent variables were fixed for pulse width (600 ns), pulse number (50) and repetition rate (10 Hz). Electropermeabilization served as the biological endpoint, with green fluorescence due to cell uptake of the nuclear dye YO-PRO-1® (YP1) tracer molecule serving the response variable. An agarose-based 3-D tissue model was used to acquire, quantify and compare fluorescence intensity data in vitro, which was measured by stereomicroscopy to enable macro versus micro level 2-D visualization. Results of this investigation showed that increasing the magnitude of the applied voltage shifts unipolar responses from localization at the anodal to cathodal electrode, and that adding a second proximal ground electrode increases the response area. Bipolar nsPEF responses were generally less intense than unipolar, but these depended on both the inter-electrode location measured and amplitude of the second phase. CANCAN preliminary indicated some ability to decrease strong uptake at electrodes, but evaluation across experimental and published data indicate that greater differences between unipolar and bipolar responses are needed to improve possibilities for distal stimulation. Overall, this work demonstrated the potential for more complex pulser-electrode configurations to successfully modulate nsPEF electropermeabilization in space by controlling unipolar and bipolar pulse delivery and contributed to a deeper understanding of bipolar cancellation. By providing a set of metrics for test and evaluation, the data provided herein may serve to inform model development to support prediction of nsPEF outcomes and help to more acutely define spatial-intensity relationships between nsPEFs and cell permeabilization as well as delineate requirements for future non-invasive nsPEF therapies

Modelling, Simulation and Data Analysis in Acoustical Problems

Modelling and simulation in acoustics is currently gaining importance. In fact, with the development and improvement of innovative computational techniques and with the growing need for predictive models, an impressive boost has been observed in several research and application areas, such as noise control, indoor acoustics, and industrial applications. This led us to the proposal of a special issue about “Modelling, Simulation and Data Analysis in Acoustical Problems”, as we believe in the importance of these topics in modern acoustics’ studies. In total, 81 papers were submitted and 33 of them were published, with an acceptance rate of 37.5%. According to the number of papers submitted, it can be affirmed that this is a trending topic in the scientific and academic community and this special issue will try to provide a future reference for the research that will be developed in coming years

Circuits and Systems for On-Chip RF Chemical Sensors and RF FDD Duplexers

Integrating RF bio-chemical sensors and RF duplexers helps to reduce cost and area in the current applications. Furthermore, new applications can exist based on the large scale integration of these crucial blocks. This dissertation addresses the integration of RF bio-chemical sensors and RF duplexers by proposing these initiatives. A low power integrated LC-oscillator-based broadband dielectric spectroscopy (BDS) system is presented. The real relative permittivity ε’r is measured as a shift in the oscillator frequency using an on-chip frequency-to-digital converter (FDC). The imaginary relative permittivity ε”r increases the losses of the oscillator tank which mandates a higher dc biasing current to preserve the same oscillation amplitude. An amplitude-locked loop (ALL) is used to fix the amplitude and linearize the relation between the oscillator bias current and ε”r. The proposed BDS system employs a sensing oscillator and a reference oscillator where correlated double sampling (CDS) is used to mitigate the impact of flicker noise, temperature variations and frequency drifts. A prototype is implemented in 0.18 µm CMOS process with total chip area of 6.24 mm^2 to operate in 1-6 GHz range using three dual bands LC oscillators. The achieved standard deviation in the air is 2.1 ppm for frequency reading and 110 ppm for current reading. A tunable integrated electrical balanced duplexer (EBD) is presented as a compact alternative to multiple bulky SAW and BAW duplexers in 3G/4G cellular transceivers. A balancing network creates a replica of the transmitter signal for cancellation at the input of a single-ended low noise amplifier (LNA) to isolate the receive path from the transmitter. The proposed passive EBD is based on a cross-connected transformer topology without the need of any extra balun at the antenna side. The duplexer achieves around 50 dB TX-RX isolation within 1.6-2.2 GHz range up to 22 dBm. The cascaded noise figure of the duplexer and LNA is 6.5 dB, and TX insertion loss (TXIL) of the duplexer is about 3.2 dB. The duplexer and LNA are implemented in 0.18 µm CMOS process and occupy an active area of 0.35 mm^2