2,973 research outputs found
Urban space and pervasive systems
In this paper we present an early approach for developing a
theoretical framework and understanding for designing
pervasive systems as an integral part of the urban landscape.
The research will be conducted in the city of Bath as part of the CityWare project, in a heritage environment with tourist attractions.
Here we propose to investigate the application of research
methods based on Space Syntax, which encompasses a set
of theories and techniques for the analysis of space and
spatial patterns, as a framework for understanding the
complex relationship between pervasive systems, urban
space and society in general; and the impact of the
deployment of pervasive systems on people’s relationships
to heritage, and to each other in particular
The fate of failed renal homografts retained after retransplantation
The fate of nonfunctioning or poorly functioning renal homografts which were left in situ at retransplantation was studied in 28 patients. In one recipient, lethal septicemia developed secondary to necrosis as well as infection of a retained intraabdominal graft. In three other patients, subsequent symptoms developed from retained extraperitoneal pelvic grafts, and these kidneys were removed without complication. It is suggested that grafts placed extraperitoneally can be left in place if retransplantation becomes necessary, provided that there is careful follow up study for signs of necrosis or infection. Removal of the kidney graft then may be performed electively at a later time, or this may never become necessary in a significant number of patients
Effect of heat treatment on mechanical dissipation in TaO coatings
Thermal noise arising from mechanical dissipation in dielectric reflective
coatings is expected to critically limit the sensitivity of precision
measurement systems such as high-resolution optical spectroscopy, optical
frequency standards and future generations of interferometric gravitational
wave detectors. We present measurements of the effect of post-deposition heat
treatment on the temperature dependence of the mechanical dissipation in
ion-beam sputtered tantalum pentoxide between 11\,K and 300\,K. We find the
temperature dependence of the dissipation is strongly dependent on the
temperature at which the heat treatment was carried out, and we have identified
three dissipation peaks occurring at different heat treatment temperatures. At
temperatures below 200\,K, the magnitude of the loss was found to increase with
higher heat treatment temperatures, indicating that heat treatment is a
significant factor in determining the level of coating thermal noise.Comment: accepted Classical and Quantum Gravity 201
Structural Invariance of Sunspot Umbrae Over the Solar Cycle: 1993-2004
Measurements of maximum magnetic flux, minimum intensity, and size are
presented for 12 967 sunspot umbrae detected on the NASA/NSO
spectromagnetograms between 1993 and 2004 to study umbral structure and
strength during the solar cycle. The umbrae are selected using an automated
thresholding technique. Measured umbral intensities are first corrected for a
confirming observation of umbral limb-darkening. Log-normal fits to the
observed size distribution confirm that the size spectrum shape does not vary
with time. The intensity-magnetic flux relationship is found to be steady over
the solar cycle. The dependence of umbral size on the magnetic flux and minimum
intensity are also independent of cycle phase and give linear and quadratic
relations, respectively. While the large sample size does show a low amplitude
oscillation in the mean minimum intensity and maximum magnetic flux correlated
with the solar cycle, this can be explained in terms of variations in the mean
umbral size. These size variations, however, are small and do not substantiate
a meaningful change in the size spectrum of the umbrae generated by the Sun.
Thus, in contrast to previous reports, the observations suggest the equilibrium
structure, as testified by the invariant size-magnetic field relationship, as
well as the mean size (i.e. strength) of sunspot umbrae do not significantly
depend on solar cycle phase.Comment: 17 pages, 6 figures. Published in Solar Physic
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