Electromagnetic Analysis of Horn Antennas in the Terahertz region

This thesis is concerned with the application of electromagnetic modelling techniques to the analysis of horn antenna characteristics over the terahertz range, 0.1 THz to 5 THz. The mode matching technique based on a scattering matrix approach to describe beam propagation in both the forward and backward direction is applied to the analysis of conical and pyramidal horn antenna both single and multi-moded, in particular the multi-moded pyramidal horn antenna array of the SAFARI instrument - a far infrared imaging spectrometer to be launched onboard the future SPICA mission. A second electromagnetic method - the finite integration technique is applied to the analysis of simple waveguide structures and characteristics associated with them through commercially available package CST. Where appropriate a quasi-optical approach to the analysis is also applied for comparison and verification of the results, namely Gaussian beam mode analysis. The underlying theory behind these analytical techniques and their implementation is provided along with descriptions of software packages used in the analysis, these are μWave Wizard a commercially available software package based on the mode matching technique, CST Microwave studio commercially available software utilising the finite integration technique and SCATTER code developed at NUI Maynooth using the mode matching technique. Gaussian beam mode propagation using both Gauss-Laguerre and Gauss-Hermite mode sets is implemented by code written within the Mathmatica environment. The effectiveness of each method in its application to particular structures to obtain accurate and computationally feasible results is discussed. Particular effects inherent is quasi-optical systems, crosstalk and standing wave effects are analysed in addition in later chapters. These effects are analysed both experimentally using a vector network analyser and within appropriate computational models

Electromagnetic Analysis of Horn Antennas in the Terahertz region

This thesis is concerned with the application of electromagnetic modelling techniques to the analysis of horn antenna characteristics over the terahertz range, 0.1 THz to 5 THz. The mode matching technique based on a scattering matrix approach to describe beam propagation in both the forward and backward direction is applied to the analysis of conical and pyramidal horn antenna both single and multi-moded, in particular the multi-moded pyramidal horn antenna array of the SAFARI instrument - a far infrared imaging spectrometer to be launched onboard the future SPICA mission. A second electromagnetic method - the finite integration technique is applied to the analysis of simple waveguide structures and characteristics associated with them through commercially available package CST. Where appropriate a quasi-optical approach to the analysis is also applied for comparison and verification of the results, namely Gaussian beam mode analysis. The underlying theory behind these analytical techniques and their implementation is provided along with descriptions of software packages used in the analysis, these are μWave Wizard a commercially available software package based on the mode matching technique, CST Microwave studio commercially available software utilising the finite integration technique and SCATTER code developed at NUI Maynooth using the mode matching technique. Gaussian beam mode propagation using both Gauss-Laguerre and Gauss-Hermite mode sets is implemented by code written within the Mathmatica environment. The effectiveness of each method in its application to particular structures to obtain accurate and computationally feasible results is discussed. Particular effects inherent is quasi-optical systems, crosstalk and standing wave effects are analysed in addition in later chapters. These effects are analysed both experimentally using a vector network analyser and within appropriate computational models

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Electromagnetic Analysis of Horn Antennas in the Terahertz region

This thesis is concerned with the application of electromagnetic modelling techniques to the analysis of horn antenna characteristics over the terahertz range, 0.1 THz to 5 THz. The mode matching technique based on a scattering matrix approach to describe beam propagation in both the forward and backward direction is applied to the analysis of conical and pyramidal horn antenna both single and multi-moded, in particular the multi-moded pyramidal horn antenna array of the SAFARI instrument - a far infrared imaging spectrometer to be launched onboard the future SPICA mission. A second electromagnetic method - the finite integration technique is applied to the analysis of simple waveguide structures and characteristics associated with them through commercially available package CST. Where appropriate a quasi-optical approach to the analysis is also applied for comparison and verification of the results, namely Gaussian beam mode analysis. The underlying theory behind these analytical techniques and their implementation is provided along with descriptions of software packages used in the analysis, these are μWave Wizard a commercially available software package based on the mode matching technique, CST Microwave studio commercially available software utilising the finite integration technique and SCATTER code developed at NUI Maynooth using the mode matching technique. Gaussian beam mode propagation using both Gauss-Laguerre and Gauss-Hermite mode sets is implemented by code written within the Mathmatica environment. The effectiveness of each method in its application to particular structures to obtain accurate and computationally feasible results is discussed. Particular effects inherent is quasi-optical systems, crosstalk and standing wave effects are analysed in addition in later chapters. These effects are analysed both experimentally using a vector network analyser and within appropriate computational models

Electromagnetic Analysis of Horn Antennas in the Terahertz region

This thesis is concerned with the application of electromagnetic modelling techniques to the analysis of horn antenna characteristics over the terahertz range, 0.1 THz to 5 THz. The mode matching technique based on a scattering matrix approach to describe beam propagation in both the forward and backward direction is applied to the analysis of conical and pyramidal horn antenna both single and multi-moded, in particular the multi-moded pyramidal horn antenna array of the SAFARI instrument - a far infrared imaging spectrometer to be launched onboard the future SPICA mission. A second electromagnetic method - the finite integration technique is applied to the analysis of simple waveguide structures and characteristics associated with them through commercially available package CST. Where appropriate a quasi-optical approach to the analysis is also applied for comparison and verification of the results, namely Gaussian beam mode analysis. The underlying theory behind these analytical techniques and their implementation is provided along with descriptions of software packages used in the analysis, these are μWave Wizard a commercially available software package based on the mode matching technique, CST Microwave studio commercially available software utilising the finite integration technique and SCATTER code developed at NUI Maynooth using the mode matching technique. Gaussian beam mode propagation using both Gauss-Laguerre and Gauss-Hermite mode sets is implemented by code written within the Mathmatica environment. The effectiveness of each method in its application to particular structures to obtain accurate and computationally feasible results is discussed. Particular effects inherent is quasi-optical systems, crosstalk and standing wave effects are analysed in addition in later chapters. These effects are analysed both experimentally using a vector network analyser and within appropriate computational models

Asking the Right Questions: Views on Genetic Variation Research Among Black and White Research Participants

Genetic variation research (GVR) may raise concerns about misuse of information and discrimination. Seemingly contradictory positive views about GVR have also been reported