Applications of Antenna Technology in Sensors

During the past few decades, information technologies have been evolving at a tremendous rate, causing profound changes to our world and to our ways of living. Emerging applications have opened u[ new routes and set new trends for antenna sensors. With the advent of the Internet of Things (IoT), the adaptation of antenna technologies for sensor and sensing applications has become more important. Now, the antennas must be reconfigurable, flexible, low profile, and low-cost, for applications from airborne and vehicles, to machine-to-machine, IoT, 5G, etc. This reprint aims to introduce and treat a series of advanced and emerging topics in the field of antenna sensors

Synthesis of Nanomaterials Via Anodic Aluminium Oxide Templates.

This thesis is concerned with the synthesis of ID nanomaterials via a template-assisted route. Porous anodic aluminium oxide templates prepared electrochemically have been utilised with two intrinsically different deposition techniques, sol-gel and high power pulsed magnetron sputtering (HPPMS), to obtain ID metal and metal oxide nano wires and nanotubes. The resultant morphologies and crystal structures were examined via SEM, XPS, XRD, TEM and EELS. A number of porous template alumina structures have been grown via the anodisation of pure and sputtered aluminium. The effects of surface pre-treatments, etching treatments and anodisation conditions on the resultant morphologies were investigated. It has been found that pore growth is largely dependent on the surface roughness of the substrate as well as the anodisation conditions. The anodisation duration is critical in promoting and allowing self-ordering. Obtained templates, varied in thickness from a few hundred nm to several tens of pm, with an average pore diameter of 70 nm, interpore distance of 100 nm and pore density of 4 x 1010 cm2 . The implementation of HPPMS led to the successful deposition of Ti inside the alumina template to depths of around 45-50 nm. It was found that templates with highly parallel pores on a rigid substrate such as Si, are more suited if this deposition method is to be used. Control of the pressure and substrate biasing is critical in avoiding ‘pinch-off and ‘bridging’ and leading to complete pore filling. The results have shown that HPPMS is a promising plasma technology for the synthesis of nanomaterials such as nanodots, nanopillars or nanowires, when used with porous alumina templates under appropriate conditions. The use of sol-gel deposition has led to the growth of a number of interesting materials and structures. Nanocrystalline CeO2 and Ce1-xZrxO2 and Ce1-xSmxO2 thin films and powders have been successfully obtained exhibiting novel micro- and nano-structures, likely to find useful applications in catalysis and gas sensing due to their redox properties and large surface to volume ratio. Furthermore, the treatment of porous alumina templates via a sol-gel/hydrothermal method led to the formation of Ce-doped γ-AI2O3 nanowires. Hence, a simple, direct and cost effective method for producing large scale AI2O3 (and doped AI2O3) nanowires is reported. Moreover, by annealing at temperatures above 600°C, nanowires of different crystallographic forms such as d-, 0- and a-AI2O3 can also be readily obtained. As the dopant Ce was successfully introduced through this method a wide range of doped-Al2O3 nanowires (by other rare earths such as Y, La, Gd, Sm), at various concentrations (e.g. 1, 3, 5 at. %) can be readily obtained

Evidence for the use of ultrasound therapy for the management of mandibular osteoradionecrosis

Introduction: The treatment of mandibular osteoradionecrosis includes antibiotics and curettage, hyperbaric oxygen, surgery, and more recently, therapeutic ultrasound. The aim of this thesis was to establish the possible mechanisms of action of therapeutic ultrasound, that could explain its excellent clinical results. Material and Methods: Two ultrasound machines were evaluated, a 'traditional' (1 MHz and 3 MHz) and a 'long wave' machine (45 kHz). Ultrasound was applied to human mandibular osteoblasts, gingival fibroblasts, peripheral blood monocytes (PBMc) and mice calvaria. The following in vitro assays were performed: cell proliferation, collagen and non-collagenous protein (NCP) synthesis, bone resorption, cytokines and angiogenesis factors production using ELISA and RT-PCR techniques, and nitric oxide production. To evaluate the effects of ultrasound on angiogenesis in vivo, the chick chorioallanlbic membrane assay (CAM) was used. The use of near infrared spectroscopy (NIRS) for the measurement of radiotherapy effects in the mandible (deoxyhaemoglobin concentrations) was also evaluated. Results: Ultrasound stimulated bone formation in the mice calvaria. Cell proliferation assays showed an increase of DNA synthesis in fibroblasts and osteoblasts, up to 52%. Collagen/NCR synthesis was also enhanced, in fibroblasts up to 48%, and in osteoblasts up to 112%. Bone resorption, part of the bone turnover process, was promoted, and there is suggestion that the cyclo-oxygenase pathway is involved. In relation to cytokine production, a slight stimulation of IL-1beta was noted in all cell types. There was no difference in IL-6 and TNFalpha levels. The angiogenesis factors, IL-8 and bFGF, were significantly stimulated in osteoblasts, and VEGF was significantly stimulated in fibroblasts, osteoblasts and PBMc. RT-PCR showed that ultrasound induces mRNA transcription for several cytokines and bone related proteins, with the most evident effect being the induction of VEGF transcription in osteoblasts. The CAM assay showed that direct ultrasound application and insonated medium from fibroblasts induced angiogenesis in vivo. The best overall stimulatory intensities were 15 and 30 mW/cm2(SA) with 45 kHz ultrasound, and 0.1 and 0.4 W/cm2(SAPA) with 1 MHz ultrasound. The NIRS evaluation showed that it is very sensitive to measure deoxyhaemoglobin concentrations, however these measurements are not reproducible. No age correlations could be performed, and the differences between normal and radiotherapy mandibles was not significant because of the great variability in the measurements. Conclusions: These results show that ultrasound can correct hypocellularity, hypoxia and hypovascularity observed in osteoradionecrosis. It stimulates cell proliferation, bone formation, healing, and angiogenesis. Further in vivo experiments are recommended as well as prospective clinical trials using therapeutic ultrasound for the treatment and prevention of osteoradionecrosis, but NIRS cannot be used to measure the outcome of treatment. Therapeutic ultrasound is a viable option for the management of mandibular osteoradionecrosis, since it is effective, inexpensive and readily available

NASA Patent Abstracts Bibliography: A Continuing Bibliography. Section 2: Indexes (supplement 32)

A subject index is provided for over 4700 patents and patent applications for the period May 1969 through December 1987. Additional indexes list personal authors, corporate authors, contract numbers, NASA case numbers, U.S. patent class numbers, U.S. patent numbers, and NASA accession numbers

Aeronautical engineering: A continuing bibliography with indexes (supplement 270)

This bibliography lists 600 reports, articles, and other documents introduced into the NASA scientific and technical information system in September, 1991. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Aeronautical engineering: A cumulative index to a continuing bibliography

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037(210) through NASA SP-7037(221) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract number, report number, and accession number indexes

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 235)

This publication is a cummulative index to the abstracts contained in Supplements 223 through 234 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number