User interfaces in space science instrumentation

This thesis examines user interaction with instrumentation in the specific context of space science. It gathers together existing practice in machine interfaces with a look at potential future usage and recommends a new approach to space science projects with the intention of maximising their science return. It first takes a historical perspective on user interfaces and ways of defining and measuring the science return of a space instrument. Choices of research methodology are considered. Implementation details such as the concepts of usability, mental models, affordance and presentation of information are described, and examples of existing interfaces in space science are given. A set of parameters for use in analysing and synthesizing a user interface is derived by using a set of case studies of diverse failures and from previous work. A general space science user analysis is made by looking at typical practice, and an interview plus persona technique is used to group users with interface designs. An examination is made of designs in the field of astronomical instrumentation interfaces, showing the evolution of current concepts and including ideas capable of sustaining progress in the future. The parameters developed earlier are then tested against several established interfaces in the space science context to give a degree of confidence in their use. The concept of a simulator that is used to guide the development of an instrument over the whole lifecycle is described, and the idea is proposed that better instrumentation would result from more efficient use of the resources available. The previous ideas in this thesis are then brought together to describe a proposed new approach to a typical development programme, with an emphasis on user interaction. The conclusion shows that there is significant room for improvement in the science return from space instrumentation by attention to the user interface

Xunzi\u27s Humanistic Naturalism: Utilizing Rituals to Address Our Psychological Challenges

Xunzi [298-238 BCE] is one of the major Confucian philosophers from the Warring States period of ancient Chinese history and is widely recognized as the poster child for the “naturalistic” branch of Confucian philosophy. Xunzi is often contrasted with another Confucian thinker, Mencius. Whereas Mencius is characterized by his belief that human nature is inherently good, Xunzi is primarily identified with his belief that human nature is bad. Xunzi is also known for his theory of ritual, one of his greatest contributions to Chinese thought. In his discussion of ritual, Xunzi adopts the lens of an intriguingly psychological perspective to explain why and how rituals were created by ancient Sages as a vehicle for humans to fulfill their nature. This paper argues that the benefit of Xunzi’s theory of ritual is captured in the notion that rituals serve to satisfy the psychological needs and desires of humans. Xunzi says that formal rituals, such as marriage and funerals, allow humans to fully develop and express their natural emotions. Xunzi’s belief that ritual was created by past Sages as a way to adorn human life provides an explanation for practicing ancient traditions without appealing to any theological reasoning. Focusing on Xunzi’s insights concerning his theory of ritual, this essay argues that people are better off addressing their psychological challenges without appealing to supernatural beliefs

Commissioning of a 0.8 MWth CFBC for Oxy-Fuel Combustion

Oxy-fuel fluidized bed combustion (FBC) is a new technology being developed for power production from carbonaceous fuels while producing a nearly pure steam of CO2 ready for sequestration or storage. Unlike oxy-fuel pulverized fuel combustion technology, oxy-fuel FBC offers the opportunity to use poor quality coals, hydrocarbon residues and a range of other materials including biomass. In Canada, pitches, tars and bottoms, in particular, are available in large quantities in western Canada, and this technology offers an opportunity to deal with many of these waste feedstocks in an environmentally benign manner. In addition, oxy-fuel circulating FBC (CFBC) can be fired at lower flue gas recycle ratio, offering potentially smaller plants for any given power output, and can capture sulphur in situ. CanmetENERGY has been operating a 75 kW oxy-fuel CFBC since 2006 with full flue gas recycle. Initial results were very encouraging and in order to further study oxy-fuel FBC technology, a 0.8 MWth CFBC unit has been retrofitted for oxy-fuel research. The facility is used to emulate commercial oxy-fuel CFBC performance. The modifications included adding oxygen supply, flue gas recycle train, airtight fly ash discharge, flue gas compressor for baghouse pulsing and system purge, etc., as well as upgrading the control and instrumentation for oxy-firing. The most major challenge has been to properly seal the entire CFBC unit to prevent air ingress. Fuels fired during the commissioning phase included bituminous coal and petroleum coke from the US, and lignite from Saskatchewan. Combustion under oxy-fuel conditions has proved to be very stable and the transition from air firing mode to oxyfuel firing mode and vice versa were quick and presented little operational difficulties. This work has demonstrated that the retrofitted oxy-fuel CFBC can produce a stream of flue gas containing 80% to 90% CO2. The NOx emissions were significantly lower compared to air firing in CFBC with the same fuel. SO2 capture was in the range of 70% to 75%, but limestone utilization is lower than in air-firing mode, and research is on-going to better understand sulphation under oxy-firing conditions

Accuracy of the modified Hardinge approach in acetabular positioning

© 2016 Joule Inc. or its licensors. Background: The surgical approach chosen for total hip arthroplasty (THA) may affect the positioning of the acetabular component. The purpose of this study was to examine the accuracy in orienting the acetabular component using the modified Hardinge approach. Methods: We used our institutional arthroplasty database to identify patients with primary, press-fit, hemispherical acetabular components of a metal-on-polyethylene THA performed between 2003 and 2011. Patients with radiographs obtained 1-3 years after the index procedure were included for measurement of anteversion and inclination angles. Acceptable values of anteversion and abduction angles were defined as 15° ± 10° and 40° ± 10°, respectively. Results: We identified 1241 patients from the database, and the modified Hardinge approach was used in 1010 of the patients included in our analysis. The acetabular component was anteverted in the acceptable zone in 54.1% of patients. The abduction angle was within the defined range in 79.2% of patients. Combined anteversion and abduction angles within the defined zone were present in 43.6% of patients. Conclusion: Consistent with studies examining accuracy from other approaches, our study reveals that the modified Hardinge approach was only moderately accurate in positioning the acetabular component in the acceptable zone

Three femoral stem designs without corrosion: A review of 2095 stems

© 2020 Naudie et al. Introduction: Corrosion at the head–neck interface of modular components in total hip arthroplasty (THA) has been reported as a cause of failure of modern total hip replacement implants. While this method of failure has been well described, it remains poorly understood. The purpose of this study is to review the three most commonly used uncemented femoral stems at our institution over the last fifteen years and to correlate any established risk factors with rates of revision, particularly corrosion. Methods: We reviewed 2095 patients from March 2000 to September 2015 who underwent total hip arthroplasty with one of three uncemented femoral stem designs. All stems were made of a Ti6Al4V alloy with a 12/14 taper design. We included only those stems coupled with a CoCr head and a highly crosslinked polyethylene liner. We evaluated age, gender, body mass index (BMI), femoral head size, head length, neck angle and offset and correlated these to the incidence of all cause revision, as well as revision excluding infection. Results: There were no recognized corrosion-related revisions identified. There was no association between age, BMI, gender, head length, neck angle and offset to all cause revision or revision with infection excluded (p\u3e0.05). Femoral head size less than 32mm was associated with higher all cause revision rates (OR 4.60 (95% CI 1.8, 11.8)) and when excluding infection as a reason for revision (OR 4.94 (95% CI 1.7, 14.41)). Conclusion: Over the last fifteen years, we have not identified any cases of corrosion with the three most commonly used femoral stems used at out institution. While we acknowledge that no femoral stem is immune to corrosion, certain femoral stem designs may be uniquely resistant to this mode of failure. Level of Evidence: III

Is there evidence for accelerated polyethylene wear in uncemented compared to cemented acetabular components? A systematic review of the literature

Joint arthroplasty registries show an increased rate of aseptic loosening in uncemented acetabular components as compared to cemented acetabular components. Since loosening is associated with particulate wear debris, we postulated that uncemented acetabular components demonstrate a higher polyethylene wear rate than cemented acetabular components in total hip arthroplasty. We performed a systematic review of the peer-reviewed literature, comparing the wear rate in uncemented and cemented acetabular components in total hip arthroplasty. Studies were identified using MEDLINE (PubMed), EMBASE and the Cochrane Central Register of Controlled Trials. Study quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The search resulted in 425 papers. After excluding duplicates and selection based on title and abstracts, nine studies were found eligible for further analysis: two randomised controlled trials, and seven observational studies. One randomised controlled trial found a higher polyethylene wear rate in uncemented acetabular components, while the other found no differences. Three out of seven observational studies showed a higher polyethylene wear in uncemented acetabular component fixation; the other four studies did not show any differences in wear rates. The available evidence suggests that a higher annual wear rate may be encountered in uncemented acetabular components as compared to cemented components