Design and Development of Planar Antennas and Dielectric Devices for use at W Band Frequencies

The main topic examined in this thesis is the development of planar antennas for observations at W band frequencies. A large portion of this analysis is based on the specific development of devices as part of an ESA research package entitled “New Technology High Efficiency Horn Antennas for CMB Experiments and Far-Infrared Astronomy”. The development of W band focal plane pixels (planar antenna with small lenses) was part of the research in this work package. Several planar antenna designs are modelled and optimised in CST Studio Microwave Suite, a commercially available computer modelling software used extensively in order to predict the device performance around 100 GHz. The final designs were manufactured and their beam patterns were measured in the Vector Network Analyser (VNA) setup. The main body of this research consisted of the development and analysis of patch antennas. The design of back-fed and side-fed patch antennas are modelled in the CST work environment, manufactured in-house and measured with the VNA. A number of lenslet (small lenses for each planar antenna in the array) designs constructed from High Density Polyethylene (HDPE) are developed as part of this ESA contract in order to develop a lens array for a planar antenna array. A particular focus was put on reducing the potential crosstalk between neighbouring pixels and optimising the lens shape. The lenslets examined included a hemisphere, a cylindrical and a plano-convex lens. A novel truncated plano-convex lens was also analysed for the task of reducing crosstalk between neighbouring pixels. Plano-convex lenses with cleaved sides (referred to as a truncated lens) were manufactured and tested with the VNA. The crosstalk signal level caused by these lenslets between neighbouring pixels were considered and measured. Additional topics developed include the analysis of a multi-moded terahertz horn antenna measured in an experimental setup in Cardiff University using GBMA (Gaussian Beam Mode Analysis). This 2.7 – 5 THz pyramidal horn antenna couples to Transition Edge Sensor detectors (TESs) and was placed in a cryogenic chamber to measure the farfield pattern. The antenna was illuminated by a terahertz source through a window in the cryostat. A GBMA model was extended to include truncation of the beam at this window in order verify no loss of signal and to ensure all power propagated though this window

Design and Development of Planar Antennas and Dielectric Devices for use at W Band Frequencies

The main topic examined in this thesis is the development of planar antennas for observations at W band frequencies. A large portion of this analysis is based on the specific development of devices as part of an ESA research package entitled “New Technology High Efficiency Horn Antennas for CMB Experiments and Far-Infrared Astronomy”. The development of W band focal plane pixels (planar antenna with small lenses) was part of the research in this work package. Several planar antenna designs are modelled and optimised in CST Studio Microwave Suite, a commercially available computer modelling software used extensively in order to predict the device performance around 100 GHz. The final designs were manufactured and their beam patterns were measured in the Vector Network Analyser (VNA) setup. The main body of this research consisted of the development and analysis of patch antennas. The design of back-fed and side-fed patch antennas are modelled in the CST work environment, manufactured in-house and measured with the VNA. A number of lenslet (small lenses for each planar antenna in the array) designs constructed from High Density Polyethylene (HDPE) are developed as part of this ESA contract in order to develop a lens array for a planar antenna array. A particular focus was put on reducing the potential crosstalk between neighbouring pixels and optimising the lens shape. The lenslets examined included a hemisphere, a cylindrical and a plano-convex lens. A novel truncated plano-convex lens was also analysed for the task of reducing crosstalk between neighbouring pixels. Plano-convex lenses with cleaved sides (referred to as a truncated lens) were manufactured and tested with the VNA. The crosstalk signal level caused by these lenslets between neighbouring pixels were considered and measured. Additional topics developed include the analysis of a multi-moded terahertz horn antenna measured in an experimental setup in Cardiff University using GBMA (Gaussian Beam Mode Analysis). This 2.7 – 5 THz pyramidal horn antenna couples to Transition Edge Sensor detectors (TESs) and was placed in a cryogenic chamber to measure the farfield pattern. The antenna was illuminated by a terahertz source through a window in the cryostat. A GBMA model was extended to include truncation of the beam at this window in order verify no loss of signal and to ensure all power propagated though this window

New Apprenticeships in Ireland

Short Abstract: There are twenty-seven statutory Apprenticeships in Ireland. The Department of Education and Skills has a strategy to develop over a hundred new Apprenticeships. This paper addresses the steps being taken to develop these programmes and to encourage stakeholders to engage with Apprenticeship as a mode of education. Full Abstract: There are twenty-seven statutory Apprenticeships in Ireland. The Department of Education and Skills has a strategy to develop over a hundred new Apprenticeships. Without a strong industrial heritage, and having developed significant Higher Education capacity only in recent decades, Irish society has a limited perception of the purpose of and advantages of vocational education. The benefits to Industry and to Society of having a skilled work-force is evident, but the skills needs exist across a range of areas which are not typically the purview of Higher Education Establishments. These factors present a challenge to the thinking of all stakeholders including academics, students, parents, employers and state agencies. This paper addresses the steps being taken to develop these programmes and to encourage stakeholders to engage with Apprenticeship as a mode of education. It also sets out the strategy for developing and delivering such national offerings with support from the state and from industry partners

Why I Don\u27t Weld in Computer Labs

Until very recently, like many people in DIT, I had never even seen a welding laboratory. To listen to me now, you’d swear I was raised with a welding torch in my hand. That’s not the case, but when I moved jobs in September 2015, I discovered that DIT runs evening courses in welding, so I decided to sign up. Way back, when I was in college, the greatest threat to life-and-limb was either an alcoholinduced idiot injury, or at worst, the risk of burning myself with a soldering Iron. They get pretty hot, sometimes as hot as 215°C. That could give you a nasty burn

Access to Apprenticeship Programme at Dublin Institute of Technology (DIT)

Short Abstract: This programme supports the transition of students into an apprenticeship scheme. This skills sampling programme will run over twelve weeks. Students will be recruited from areas of socio-economic disadvantage in Dublin and will spend ten weeks at DIT and two weeks on work experience. This programme is being developed on a pilot basis with support from the J.P Morgan Foundation. Full Abstract: The Access to Apprenticeship Programme aims to support the transition of students (16-24 years old) into an apprenticeship scheme. This skills sampling programme will run in three terms of twelve weeks starting in September 2017, January 2018 and April 2018. Each of the three groups will comprise sixteen students, who will be recruited from areas of socio-economic disadvantage in Dublin and who will spend ten weeks at Dublin Institute of Technology and two weeks on work experience. The programme aims to attract students who, for various reasons, might not otherwise have considered a career in a semi-skilled or skilled area. They may be from a group referred to as NEETS (Not in Education, Employment, Training or School). The initial catchment is Dublin’s north inner city, which encompasses some of the areas of greatest disadvantage in Ireland. DIT, based in the heart of this area has a social and historical imperative to assist our community. The programme is being developed on a pilot basis by DIT’s College of Engineering and Built Environment with support from the J.P Morgan Foundation and the Electricity Supply Board (ESB) in Ireland

Case Studies in Thin Client Acceptance

Thin Client technology boasts an impressive range of financial, technical and administrative benefits. Combined with virtualisation technology, higher bandwidth availability and cheaper high performance processors, many believe that Thin Clients have come of age. But despite a growing body of literature documenting successful Thin Client deployments there remains an undercurrent of concern regarding user acceptance of this technology and a belief that greater efforts are required to understand how to integrate Thin Clients into existing, predominantly PC-based, deployments. It would be more accurate to state that the challenge facing the acceptance of Thin Clients is a combination of architectural design and integration strategy rather than a purely technical issue. Careful selection of services to be offered over Thin Clients is essential to their acceptance. Through an evolution of three case studies the user acceptance issues were reviewed and resolved resulting in a 92% acceptance rate of the final Thin Client deployment. No significant bias was evident in our comparison of user attitudes towards desktop services delivered over PCs and Thin Clients

Microbial associations with macrobiota in coastal ecosystems : patterns and implications for nitrogen cycling

Author Posting. © Ecological Society of America, 2016. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Frontiers in Ecology and the Environment 14 (2016): 200-208, doi:10.1002/fee.1262.In addition to their important effects on nitrogen (N) cycling via excretion and assimilation (by macrofauna and macroflora, respectively), many macrobiota also host or facilitate microbial taxa responsible for N transformations. Interest in this topic is expanding, especially as it applies to coastal marine systems where N is a limiting nutrient. Our understanding of the diversity of microbes associated with coastal marine macrofauna (invertebrate and vertebrate animals) and macrophytes (seaweeds and marine plants) is improving, and recent studies indicate that the collection of microbes living in direct association with macrobiota (the microbiome) may directly contribute to N cycling. Here, we review the roles that macrobiota play in coastal N cycling, review current knowledge of macrobial–microbial associations in terms of N processing, and suggest implications for coastal ecosystem function as animals are harvested and as foundational habitat is lost or degraded. Given the biodiversity of microbial associates of macrobiota, we advocate for more research into the functional consequences of these associations for the coastal N cycle.University of Chicago-Marine Biological Laboratories (MBL