2,143 research outputs found
Cementitious grouts for intermediate level nuclear waste (ILW) encapsulation - effect of compositional changes upon hydration
Grouts containing high levels of replacement by BFS are the preferred route to disposal for a large majority of ILW in the UK. A number of techniques, SEM image analysis, chemical shrinkage, ICC, TGA and XRD, have been applied to assess the rate and degree of hydration of such cementitious grouts. This study forms a base for quantifying the effects of modifications to the physical and chemical composition of both the OPC and the BFS components of the matrix in order to identify the sensitivity or otherwise of the technique to ensure that a continuity of supply is maintained
Flow Visualization Tests of a 0.004-scale Space Shuttle Vehicle 2A Model (no. 13-OTS) in the MSFC 14-inch Trisonic Wind Tunnel (IS6A)
Documented are representative photographs of surface flow patterns, created by oil flow and shadowgraph techniques, obtained during wind tunnel tests of an 0.004-scale version of the 2A SSV orbiter. The purpose of this test series was to obtain flow visualization photographs to aid in interpretation of test IS1 aero-noise data. The test was conducted at nominal Mach numbers from 0.6 to 3.48. The orbiter was run in proximity to the external tank and solid rocket boosters at angles of attack from -5 deg to +9 deg at 0 deg angle of sideslip
The semantic effects of verb raising and its consequences in second language grammars
This article considers whether highly proficient second language speakers of English can distinguish meaning contrasts associated with constructions where there is a raising be, and constructions where there is a non-raising thematic verb, as illustrated in the difference between (1a) and (1b): 1a. Kim is reading a novel (`event-in-progress/existential ? interpretation
The spin-half Heisenberg antiferromagnet on two Archimedian lattices: From the bounce lattice to the maple-leaf lattice and beyond
We investigate the ground state of the two-dimensional Heisenberg
antiferromagnet on two Archimedean lattices, namely, the maple-leaf and bounce
lattices as well as a generalized - model interpolating between both
systems by varying from (bounce limit) to (maple-leaf
limit) and beyond. We use the coupled cluster method to high orders of
approximation and also exact diagonalization of finite-sized lattices to
discuss the ground-state magnetic long-range order based on data for the
ground-state energy, the magnetic order parameter, the spin-spin correlation
functions as well as the pitch angle between neighboring spins. Our results
indicate that the "pure" bounce () and maple-leaf () Heisenberg
antiferromagnets are magnetically ordered, however, with a sublattice
magnetization drastically reduced by frustration and quantum fluctuations. We
found that magnetic long-range order is present in a wide parameter range and that the magnetic order parameter varies only
weakly with . At a direct first-order transition to
a quantum orthogonal-dimer singlet ground state without magnetic long-range
order takes place. The orthogonal-dimer state is the exact ground state in this
large- regime, and so our model has similarities to the Shastry-Sutherland
model. Finally, we use the exact diagonalization to investigate the
magnetization curve. We a find a 1/3 magnetization plateau for and another one at 2/3 of saturation emerging only at large .Comment: 9 pages, 10 figure
Extended performance solar electric propulsion thrust system study. Volume 4: Thruster technology evaluation
Several thrust system design concepts were evaluated and compared using the specifications of the most advanced 30 cm engineering model thruster as the technology base. Emphasis was placed on relatively high power missions (60 to 100 kW) such as a Halley's comet rendezvous. The extensions in thruster performance required for the Halley's comet mission were defined and alternative thrust system concepts were designed in sufficient detail for comparing mass, efficiency, reliability, structure, and thermal characteristics. Confirmation testing and analysis of thruster and power processing components were performed, and the feasibility of satisfying extended performance requirements was verified. A baseline design was selected from the alternatives considered, and the design analysis and documentation were refined. The baseline thrust system design features modular construction, conventional power processing, and a concentrator solar array concept and is designed to interface with the Space Shuttle
Practical Interests, Relevant Alternatives, and Knowledge Attributions: an Empirical Study
In defending his interest-relative account of knowledge, Jason Stanley relies heavily on intuitions about several bank cases. We experimentally test the empirical claims that Stanley seems to make concerning our common-sense intuitions about these cases. Additionally, we test the empirical claims that Jonathan Schaffer seems to make, regarding the salience of an alternative, in his critique of Stanley. Our data indicate that neither raising the possibility of error nor raising stakes moves most people from attributing knowledge to denying it. However, the raising of stakes (but not alternatives) does affect the level of confidence people have in their attributions of knowledge. We argue that our data impugn what both Stanley and Schaffer claim our common-sense judgments about such cases are
Resources for Supporting Mathematics and Data Science Instructors During COVID-19
In late May of 2020, a few months after the raging COVID-19 pandemic forced university faculty to quickly switch to online teaching, the Associated Colleges of the South (ACS) released a call for grant applications to support working groups to help faculty within our consortium who will be teaching during the pandemic (e.g., from hybrid courses with some remote/online components to fully remote/online courses; socially distanced face-to-face courses). We replied to this call and the ACS awarded the six of us (from four ACS schools) a Summer Rapid Response Grant in early June. The grant funded our efforts to create and provide to other faculty Mathematics and Data Science Resources to Support Socially Relevant Teaching in the Time of COVID-19. This paper summarizes our efforts and includes the resources that we developed
Novel metered aerosol valve
The design and performance of a new valving mechanism for portable pressurized spraying devices is described, where
the propellant in the device is a safe gas (so-called compressed gas) propellant rather than the current liquefied gases all
of which are either volatile organic compounds or greenhouse gases. The valve sprays a fixed volume of liquid when the
spraying actuator is depressed, as is essential used medical sprays, such as pressurized metered dose inhalers and nasal
sprays, and also for automatic (wall-mounted) aerosol delivery systems for air-fresheners, insecticides and disinfectants.
For ‘compressed gas’ aerosol formats, there is no flash vaporization of propellant so that pumping liquid from a metering
chamber and atomization to form a spray must be achieved entirely by designing some means of using the pumping action
of the gas in the container to act upon the liquid in the metering chamber. The new design utilizes a loosely fitting
spherical piston element and a simple arrangement of a concentric housing and a moveable valve stem, such that liquid
flow paths between the different elements are automatically closed and opened in the correct time sequence when the
valve stem is depressed and released. Spraying data show excellent repeatability of liquid sprayed per pulse throughout
the lifetime of device and drop sizes that are acceptable for devices such as air-fresheners and nasal sprays. The valve has
only one additional component compared with liquefied gas metered valves and can be straightforwardly injection
moulded. As will be explained, previous attempts failed due to expense, complexity and unreliability.
Keywords
Aerosol valve, spray metering, insert, inhaler, air-freshene
Health-Related Quality of Life (HRQoL) changes in South Australia: comparison of burden of disease morbidity and survey-based health utility estimates
Background: Global research shows a clear transition in health outcomes over the past two decades where improved survival was accompanied by lower health related quality of life (HRQoL) as measured by morbidity and disability. These trends suggest the need to better understand changes in population HRQoL. This paper compares two perspectives on population HRQoL change using burden of disease morbidity estimates from administrative data and self-reports from random and representative population surveys. Methods: South Australian administrative data including inpatient hospital activity, cancer and communicable disease registrations were used within a Burden of Disease study framework to quantify morbidity as Prevalent Years of Life lived with Disease and injury related illness (PYLD) for 1999 to 2008. Self-reported HRQoL was measured using the Assessment of Quality of Life (AQoL) in face to face interviews with at least 3000 respondents in each of South Australia ’ s Health Omnibus Surveys (HOS) in 1998, 2004 and 2008. Results: Age specific PYLD rates for those aged 75 or more increased by 5.1%. HRQoL dis-utility in this age group also increased significantly and beyond the minimally important difference threshold. Underlying increased dis-utility were greater difficulties in independent living (particularly requiring help with household tasks) and psychological well-being (as influenced by pain, discomfort and difficulty sleeping). Conclusions: Consistent with increased quantity of life being accompanied by reduced HRQoL, the analysis indicates older people in South Australia experienced increased morbidity in the decade to 2008. The results warrant routine monitoring of health dis-utility at a population level and improvement to the supply and scope of administrative data.David Banham, Graeme Hawthorne, Robert Goldney, and Julie Ratcliff
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