592 research outputs found
The service hub as bypassed social infrastructure: evidence from inner-city Osaka.
We shed light on understudied social infrastructure by focusing on the service hub, those conspicuous clusters of voluntary sector organizations designed to help the most vulnerable urban populations. Using Kamagasaki, Osaka as an exploratory case study, we find that the service hub acts as a distinctly inner-city social infrastructure marked by very close proximity of clients and services, as well as high accessibility, mutuality, and provisionality, and clear motivations to ensure day-to-day survival. But the conversation between service hub and social infrastructure indicates that our case study must be understood as a bypassed infrastructure, unsung and out-of-sync with the market (but increasingly less so with the state). Kamagasaki suggested an social infrastructure of castoffs, standing apart and increasingly incompatible with current urbanism and its emphasis on privatization, gentrification, and neoliberal co-optation, or even with the older âinfrastructural idealâ of the Fordist era, with its emphasis on large-scale universality
Spectroscopy of Ne for the thermonuclear O()Ne and F()O reaction rates
Uncertainties in the thermonuclear rates of the
O()Ne and F()O reactions
affect model predictions of light curves from type I X-ray bursts and the
amount of the observable radioisotope F produced in classical novae,
respectively. To address these uncertainties, we have studied the nuclear
structure of Ne over MeV and MeV using
the F(He,t)Ne reaction. We find the values of the
4.14 and 4.20 MeV levels to be consistent with and
respectively, in contrast to previous assumptions. We confirm the recently
observed triplet of states around 6.4 MeV, and find evidence that the state at
6.29 MeV, just below the proton threshold, is either broad or a doublet. Our
data also suggest that predicted but yet unobserved levels may exist near the
6.86 MeV state. Higher resolution experiments are urgently needed to further
clarify the structure of Ne around the proton threshold before a
reliable F()O rate for nova models can be determined.Comment: 5 pages, 3 figures, Phys. Rev. C (in press
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Influence of annealing on microstructure and mechanical properties of ultrafine-grained Ti45Nb
Beta-Ti alloys have been intensively investigated in the last years because of their favorable low Young's moduli, biocompatibility and bio-inertness, making these alloys interesting candidates for implant materials. Due to their low mechanical strength, efforts are currently devoted to increasing it. A promising way to improve the strength is to tailor the microstructure using severe plastic deformation (SPD). In this investigation high pressure torsion was used to refine the microstructure of a Ti-45wt.%Nb alloy inducing a grain size of ~50âŻnm. The main focus of the subsequent investigations was devoted to the thermal stability of the microstructure. Isochronal heat-treatments performed for 30âŻmin in a temperature range up to 500âŻÂ°C caused an increase of hardness with a peak value at 300âŻÂ°C before the hardness decreased at higher temperatures. Simultaneously, a distinct temperature-dependent variation of the Young's modulus was also measured. Tensile tests revealed an increase in strength after annealing compared to the SPD-state. Microstructural investigations showed that annealing causes the formation of α-Ti. The findings suggest that the combination of severe plastic deformation with subsequent heat treatment provides a feasible way to improve the mechanical properties of SPD-deformed ÎČ-Ti alloys making them suitable for higher strength applications
Usefulness of an Intrapartum Ultrasound Simulator (IUSimâą) for Midwife Training: Results from an RCT
Introduction: We conducted a randomized study to determine whether a training session on a dedicated simulator (IUSimâą) would facilitate the midwives in learning the technique of transperineal intrapartum ultrasound. Methods: Following a 30-min multimedia presentation including images and videos on how to obtain and measure the angle of progression (AoP) and the head-perineum distance (HPD), 6 midwives with no prior experience in intrapartum ultrasound were randomly split into 2 groups: 3 of them were assigned to the "training group"and 3 to the "control group."The midwives belonging to the former group were taught to measure the 2 sonographic parameters during a 3-h practical session conducted on IUSimâą under the supervision of an expert obstetrician. In the following 3 months, all the 6 midwives were asked to independently perform transperineal ultrasound during their clinical practice and to measure on the acquired images either the AoP or the HPD. The sonographic images were examined in blind by the teaching obstetrician who assigned a 0-3 score to the image quality (IQS) and to the measurement quality (MQS). Results: A total of 48 ultrasound images (24 patients) from 5 midwives were acquired and included in the study analysis. A midwife of the "training group"declined participation after the practical session. Independently from the randomization group, the image quality score (IQS + MQS) was significantly higher for the HPD compared with the AoP (2.5 ± 0.66 vs. 1.79 ± 1.14; p = 0.01). In the training group, the MQS of either AoP (2.66 ± 0.5 vs.1.46 ± 1.45. p = 0.038) and the HPD (2.9 ± 0.33 vs. 1.87 ± 0.83 p = 0.002) was significantly higher in comparison with the control group, while the IQS of both measurements was comparable between the 2 groups (1.91 ± 1.24 vs. 2.25 ± 0.865; p = 0.28). Conclusion: The use of a dedicated simulator may facilitate the midwives in learning how to measure the AoP and the HPD on transperineal ultrasound images
Development of an Anger camera in Lanthanum Bromide for gamma-ray space astronomy in the MeV range
International audienceLanthanum bromide is a very promising scintillator material for the next generation of g-ray telescopes. We present in this paper first g-ray imaging results obtained by coupling a LaBr3 crystal with a position-sensitive 8Ă8 multianode photomultiplier tube to form a simple Anger camera module. The readout of the 64 signals is carried out with the most recent evolution of the MultiAnode ReadOut Chip (MAROC) which was initially designed for the luminometer of the ATLAS detector. Measured charge distributions are compared with detailed GEANT4 simulations that include the tracking of the optical photons produced in the scintillation crystal. The depth of interaction (d.o.i.) of 662-keV g-rays inside the crystal is derived from the charge distributions using an artificial neural network. We obtain for an irradiation at detector centre a mean standard deviation of the d.o.i. of 1.69 mm. Such a position-sensitive g-ray detector can form an innovative building block for a future space calorimete
Gamma ray production cross sections in proton induced reactions on natural Mg, Si and Fe targets over the proton energy range 30 up to 66 MeV
Gamma-ray excitation functions have been measured for 30, 42, 54 and 66 MeV
proton beams accelerated onto C + O (Mylar), Mg, Si, and Fe targets of
astrophysical interest at the separate-sector cyclotron of iThemba LABS in
Somerset West (Cape Town, South Africa). A large solid angle, high energy
resolution detection system of the Eurogam type was used to record Gamma-ray
energy spectra. Derived preliminary results of Gamma-ray line production cross
sections for the Mg, Si and Fe target nuclei are reported and discussed. The
current cross section data for known, intense Gamma-ray lines from these nuclei
consistently extend to higher proton energies previous experimental data
measured up to Ep ~ 25 MeV at the Orsay and Washington tandem accelerators.
Data for new Gamma-ray lines observed for the first time in this work are also
reported.Comment: 11 pages, 6 figures. IOP Institute of Physics Conference Nuclear
Physics in Astrophysics VII, 28th EPF Nuclear Physics Divisional Conference,
May 18-22 2015, York, U
S17(0) Determined from the Coulomb Breakup of 83 MeV/nucleon 8B
A kinematically complete measurement was made of the Coulomb dissociation of
8B nuclei on a Pb target at 83 MeV/nucleon. The cross section was measured at
low relative energies in order to infer the astrophysical S factor for the
7Be(p,gamma)8B reaction. A first-order perturbation theory analysis of the
reaction dynamics including E1, E2, and M1 transitions was employed to extract
the E1 strength relevant to neutrino-producing reactions in the solar interior.
By fitting the measured cross section from Erel = 130 keV to 400 keV, we find
S17(0) = 17.8 (+1.4, -1.2) eV b
interference in the Coulomb dissociation of B
We investigate the effects arising out of the interference in the
Coulomb dissociation of B at beam energies below and around 50 MeV/nucleon.
The theory has been formulated within a first order semiclassical scheme of
Coulomb excitation, in which both the ground state and the continuum state wave
functions of B enter as inputs. We find that the magnitude of the
interference could be large in some cases. However, there are some specific
observables which are free from the effects of the interference,
which is independent of the models used to describe the structure of B.
This will be useful for the analysis of the breakup data in relation to the
extraction of the astrophysical factor .Comment: Revised version to appear in Physical Review
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