30,533 research outputs found
Evocative computing – creating meaningful lasting experiences in connecting with the past
We present an approach – evocative computing – that demonstrates how ‘at hand’ technologies can be ‘picked up’ and used by people to create meaningful and lasting experiences, through connecting and interacting with the past. The approach is instantiated here through a suite of interactive technologies configured for an indoor-outdoor setting that enables groups to explore, discover and research the history and background of a public cemetery. We report on a two-part study where different groups visited the cemetery and interacted with the digital tools and resources. During their activities serendipitous uses of the technology led to connections being made between personal memo-ries and ongoing activities. Furthermore, these experiences were found to be long-lasting; a follow-up study, one year later, showed them to be highly memorable, and in some cases leading participants to take up new directions in their work. We discuss the value of evocative computing for enriching user experiences and engagement with heritage practices
Quaternary and quinary modifications of eutectic superalloys strengthened by delta Ni3Cb lamellae and gamma prime Ni3Al precipitates
By means of a compositional and heat treatment optimization program based on the quaternary gamma/gamma prime-delta, a tantalum modified gamma/gamma prime-delta alloy with improved shear and creep strength combined with better cyclic oxidation resistance was identified. Quinary additions, quaternary adjustments, and heat treatment were investigated. The tantalum modified gamma/gamma prime-delta alloy possessed a slightly higher liquidus temperature and exhibited rupture strength exceeding NASA VIA by approximately three and one-half Larson-Miller parameters (C = 20) above 1000 C. Although improvements in longitudinal mechanical properties were achieved, the shear and transverse strength property goals of the program were not met and present a continuing challenge to the alloy metallurgist
Space telescope phase B definition study. Volume 2A: Science instruments, f24 field camera
The analysis and design of the F/24 field camera for the space telescope are discussed. The camera was designed for application to the radial bay of the optical telescope assembly and has an on axis field of view of 3 arc-minutes by 3 arc-minutes
Rotational Spectroscopy of PAHs: Acenaphthene, Acenaphthylene and Fluorene
Pure rotational spectra of three polycyclic aromatic hydrocarbons -
acenaphthene, acenaphthylene and fluorene - have been obtained by Fourier
transform microwave spectroscopy of a molecular beam and subsequently by
millimeter wave absorption spectroscopy for acenaphthene and fluorene. The data
presented here will be useful for deep radio astronomical searches for PAHs
employing large radio telecopes.Comment: 2 pages, 1 figure (uses iaus.sty), to appear in IAU Symposium No.
231, Astrochemistry - Recent Successes and Current Challenges, eds. D. C.
Lis, G. A. Blake & E. Herbst (Cambridge Univ. Press
Clustering of equine grass sickness cases in the United Kingdom: a study considering the effect of position-dependent reporting on the space-time K-function
Equine grass sickness (EGS) is a largely fatal, pasture-associated dysautonomia. Although the aetiology of this disease is unknown, there is increasing evidence that Clostridium botulinum type C plays an important role in this condition. The disease is widespread in the United Kingdom, with the highest incidence believed to occur in Scotland. EGS also shows strong seasonal
variation (most cases are reported between April and July). Data from histologically confirmed cases of EGS from England and Wales in 1999 and 2000 were collected from UK veterinary diagnostic centres. The data did not represent a complete census of cases, and the proportion of all cases reported to the centres would have varied in space and, independently, in time. We consider the variable reporting of this condition and the appropriateness of the space–time K-function when exploring the spatial-temporal properties of a ‘thinned’ point process. We
conclude that such position-dependent under-reporting of EGS does not invalidate the Monte Carlo test for space–time interaction, and find strong evidence for space–time clustering of EGS cases (P<0.001). This may be attributed to contagious or other spatially and temporally localized processes such as local climate and/or pasture management practices
A study of the ozonolysis of isoprene in a cryogenic buffer gas cell by high resolution microwave spectroscopy
We have developed a method to quantify reaction product ratios using high
resolution microwave spectroscopy in a cryogenic buffer gas cell. We
demonstrate the power of this method with the study of the ozonolysis of
isoprene, CH2=C(CH3)-CH=CH2, the most abundant, non-methane hydrocarbon emitted
into the atmosphere by vegetation. Isoprene is an asymmetric diene, and reacts
with O3 at the 1,2 position to produce methyl vinyl ketone (MVK), formaldehyde,
and a pair of carbonyl oxides: [CH3CO-CH=CH2 + CH2=OO] + [CH2=O +
CH3COO-CH=CH2]. Alternatively, O3 could attack at the 3,4 position to produce
methacrolein (MACR), formaldehyde, and two carbonyl oxides [CH2=C(CH3)-CHO +
CH2=OO] + [CH2=O + CH2=C(CH3)-CHOO]. Purified O3 and isoprene were mixed for
approximately 10 seconds under dilute (1.5-4% in argon) continuous flow
conditions in an alumina tube held at 298 K and 5 Torr. Products exiting the
tube were rapidly slowed and cooled within the buffer gas cell by collisions
with cryogenic (4-7 K) He. High resolution chirped pulse microwave detection
between 12 and 26 GHz was used to achieve highly sensitive (ppb scale),
isomer-specific product quantification. We observed a ratio of MACR to MVK of
2.1 +/- 0.4 under 1:1 ozone to isoprene conditions and 2.1 +/- 0.2 under 2:1
ozone to isoprene conditions, a finding which is consistent with previous
experimental results. Additionally, we discuss relative quantities of formic
acid (HCOOH), an isomer of CH2=OO, and formaldehyde (CH2=O) under varying
experimental conditions, and characterize the spectroscopic parameters of the
singly-substituted 13C trans-isoprene and 13C anti-periplanar-methacrolein
species. This work has the potential to be extended towards a complete
branching ratio analysis, as well towards the ability to isolate, identify, and
quantify new reactive intermediates in the ozonolysis of alkenes
Detection of 84-GHz class I methanol maser emission towards NGC 253
We have investigated the central region of NGC 253 for the presence of
84.5-GHz (E) methanol emission using the Australia
Telescope Compact Array. We present the second detection of 84.5-GHz class~I
methanol maser emission outside the Milky Way. This maser emission is offset
from dynamical centre of NGC 253, in a region with previously detected emission
from class~I maser transitions (36.2-GHz E and 44.1-GHz
A methanol lines) . The emission features a narrow
linewidth (12 km s) with a luminosity approximately 5 orders of
magnitude higher than typical Galactic sources. We determine an integrated line
intensity ratio of between the 36.2 GHz and 84.5-GHz class I
methanol maser emission, which is similar to the ratio observed towards
Galactic sources. The three methanol maser transitions observed toward NGC 253
each show a different distribution, suggesting differing physical conditions
between the maser sites and that observations of additional class~I methanol
transitions will facilitate investigations of the maser pumping regime.Comment: Accepted into ApJL 12 October 2018. 10 pages, 3 Figures and 2 Table
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