Valiente Kroon's obstructions to smoothness at infinity

We conjecture an interpretation in terms of multipole moments of the obstructions to smoothness at infinity found for time-symmetric, conformally-flat initial data by Valiente Kroon (Comm. Math. Phys. 244 (2004), 133-156).Comment: To appear in GR

GaN radiation detectors for particle physics and synchrotron applications

In this thesis the work will focus on the development of wide band gap radiation detectors for radiation hard, biological and monitoring applications. Gallium nitride (GaN) was investigated as a radiation hard particle detector and as an UV light detector while the properties of single crystal diamond as a soft x-ray beam position monitor were assessed. Photolithographic processes were used to produce Schottky pad detectors of 1 mm diameter on three epitaxial GaN wafers grown on a sapphire substrate. Two of the wafers were obtained from Tokushima University, Japan and had an epitaxial thickness of 2.5 mum while the third GaN wafer was grown by Lumilog, France and had an epitaxial thickness of 12 mum. Devices were irradiated with 24 GeV/c protons and neutrons (1 MeV equivalent) to fluences of 10[14], 10[15], 2x10[15], 5x10[15] and 10[16] particles cm[-2] and the macroscopic properties characterised through current-voltage (I-V), capacitance-voltage (C-V) and charge collection efficiency measurements using alpha particles. The leakage currents of the irradiated GaN detectors were in some cases orders of magnitude smaller than the unirradiated devices. This phenomenon has also been observed in other irradiated wide band gap semiconductors, SiC and diamond. The maximum CCE of the thin epitaxial GaN detector was 97% while the thicker epitaxial GaN detector exhibited a maximum CCE of 53%. Irradiation with protons and neutrons led to a dramatic reduction in the CCE of the GaN detectors. For example, the CCE of one of the thin epitaxial GaN detectors dropped from 97% pre-irradiation to 40% after irradiation to 10[16] neutrons cm[-2] and 13% after irradiation to 10[16] protons cm[-2]. The drop in CCE of the thicker epitaxial material was less pronounced however the devices irradiated to the highest fluences, 1016 neutrons cm[-2] and 10[16] protons cm-2 exhibited CCEs of only 17% and 25% respectively. Attempts were made at identifying and understanding the microscopic as-grown and radiation-induced defects that determine the macroscopic characteristics of the GaN detectors. The microscopic properties of unirradiated and irradiated GaN detectors were evaluated using photoluminescence (PL), contact photoconductivity (CPC) and thermally stimulated current (TSC) techniques. Both PL and CPC measurements of the irradiated devices revealed a substantial increase in non-radiative recombination. In particular the intensity of the yellow band PL peak is significantly reduced after irradiation to 10[16]particles cm[-2]. TSC measurements of the GaN detectors revealed several competing complicated transport mechanisms. Thermal activation energies of 0.16-0.2, 0.27-0.32, 0.36-0.45 and 0.73-0.74 eV were extracted from neutron irradiated thin epitaxial GaN detectors. Dry etching of various GaN materials was done in a inductively coupled plasma (ICP) machine. The GaN samples were etched in order to produce ohmic contacts to the n-GaN buffer layers and to realise a parallel plate capacitor detector geometry. From the current-voltage and capacitance- voltage characteristics of the etched devices the ideality factor, Schottky barrier height and carrier concentration were extracted. The parallel plate capacitor geometry of the etched devices resulted in an increase in charge collection efficiency compared to the unetched devices. This is attributed to better definition of the electric field within the etched devices resulting in significantly improved charge transport

Business valuation in bankruptcy : a nonhauthoritative guide; Consulting services practice aid, 02-1

https://egrove.olemiss.edu/aicpa_news/1167/thumbnail.jp

Building new housing in remote Indigenous communities

SOCIAL AND ECONOMIC BENEFITS CAN ACCOMPANY CAPITAL INVESTMENT IN HOUSING AND INFRASTRUCTURE. THESE ARE MORE LIKELY TO BE REALISED WHEN CONTRACTING METHODS FOR HOUSING PROCUREMENT ARE ALIGNED TO COMMUNITY NEEDS. ALLIANCE CONTRACTING, WHERE RISKS ARE SHARED, CAN SUPPORT INNOVATION IN THE PROCUREMENT SYSTEM TO ACHIEVE ADDITIONAL SOCIAL AND ECONOMIC BENEFITS

Housing Intervention and Neighbourhood Development: Harnessing Change in West Broadway

During the period leading to the early 1990s the West Broadway area of inner city Winnipeg experienced many signs of neighbourhood decline, such as residential fires, housing abandonment and structural deterioration. From the mid 1990s considerable amounts of volunteer energy, public funding and philanthropic resources were devoted to turning the neighbourhood around, focusing efforts through community development, employment training, arts programs, housing upgrading and other themes. Many individuals and organizations combined their capabilities in the attempt to create an inclusive and diverse community. The study Housing Intervention and Neighbourhood Development was grounded in the need to take stock of changes in the neighbourhood and to relate these to knowledge of the nature of neighbourhood change. It was intended that this would enable an informed assessment of whether dynamics such as gentrification, disinvestment and stabilization appear to be in operation in parts of the neighbourhood. This assessment, in turn, would support discussion of strategies that could be implemented to help guide how the neighbourhood would unfold

Resolving debris discs in the far-infrared: early highlights from the DEBRIS survey

We present results from the earliest observations of DEBRIS, a Herschel Key Programme to conduct a volume- and flux-limited survey for debris discs in A-type through M-type stars. PACS images (from chop/nod or scan-mode observations) at 100 and 160 micron are presented toward two A-type stars and one F-type star: beta Leo, beta UMa and eta Corvi. All three stars are known disc hosts. Herschel spatially resolves the dust emission around all three stars (marginally, in the case of beta UMa), providing new information about discs as close as 11 pc with sizes comparable to that of the Solar System. We have combined these data with existing flux density measurements of the discs to refine the SEDs and derive estimates of the fractional luminosities, temperatures and radii of the discs.Comment: to be published in A&A, 5 pages, 2 color figure

Capsule endoscopy compatible fluorescence imager demonstrated using bowel cancer tumours

We demonstrate a proof of concept highly miniaturised fluorescence imager and its application to detecting cancer in resected human colon cancer tissues. Fluorescence imaging modalities have already been successfully implemented in traditional endoscopy. However, the procedure still causes discomfort and requires sedation. Wireless fluorescence capsule endoscopy has the potential to improve diagnostic accuracy with less inconvenience for patients. In this paper we present a 5 mm x 6 mm x 5 mm optical block that is small enough to integrate into a capsule endoscope. The block integrates ultrathin filters for optical isolation and was successfully integrated with a sensitive CMOS SPAD array to detect green fluorescence from Flavin Adenine Dinucleotide (FAD), which is an endogenous fluorophore responsible for autofluorescence in human tissues, and fluorescence from the cancer selective molecular probe ProteoGREENTM-gGlu used to label colorectal cancer cells. In vitro studies were validated using a commercial ModulusTM Microplate reader. The potential use of the device in capsule endoscopy was further validated by imaging healthy and malignant resected human tissues from the colon to detect changes in autofluorescence signal that are crucial for cancer diagnosis

Quantification of Ultrasound Correlation‐Based Flow Velocity Mapping and Edge Velocity Gradient Measurement

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135662/1/jum201332101815.pd