1,509 research outputs found
AC Loss and Contact Resistance In Copper-Stabilized Nb3Al Rutherford Cables with and without a Stainless Steel Core
Calorimetric measurements of AC loss and hence interstrand contact resistance
(ICR), were measured on three samples of Rutherford cable wound with
Cu-stabilized jelly-roll type unplated Nb3Al strand. One of the cable types was
furnished with a thin core of AISI 316L stainless steel and the other two were
both uncored but insulated in different ways. The cables were subjected to a
room-temperature-applied uniaxial pressure of 12 MPa that was maintained during
the reaction heat treatment (RHT), then vacuum impregnated with CTD 101 epoxy,
and repressurized to 100 MPa during AC-loss measurement. The measurements were
performed at 4.2 K in a sinusoidal field of amplitude 400 mT at frequencies of
1 to 90 mHz (no DC-bias field) that was applied both perpendicular and parallel
to the face of the cable (the face-on, FO, and edge-on, EO, directions,
respectively). For the cored cable the FO-measured effective ICR (FO-ICR), was
5.27 . Those for the uncored cables were less than 0.08
. As shown previously for NbTi- and Nb3Sn-based Rutherford
cables, the FO-ICR can be significantly increased by the insertion of a core,
although in this case it is still below the range recommended for
accelerator-magnet use. Post-measurement dissection of one of the cables showed
that the impregnating resin had permeated between the strands and coated the
core with a thin, insulating layer excepting for some sintered points of
contact. In the uncored cables the strands were coated with resin except for
the points of interstrand contact. It is suggested that in the latter case this
tendency for partial coating leads to a processing-sensitive FO-ICR.Comment: Four pages, with two figure
First-year experience of chemotherapy for advanced retinoblastoma in Tanzania: disease profile, outcomes, and challenges in 2008.
PURPOSE: To examine the profile of retinoblastoma in a national tertiary referral center in Tanzania and to report first-year outcomes of its treatment using chemotherapy. METHODS: All patients with retinoblastoma referred in 2008 were included. Disease was classified on clinical grounds as ocular, orbital, or metastatic. Those with ocular and orbital disease received chemotherapy. Remission was the main outcome measure and defined as absence of disease at the end of treatment. RESULTS: In 2008, 37 patients (20 males and 17 females) with retinoblastoma were referred to Ocean Road Cancer Institute. The mean delay from the first sign of disease to presentation at hospital was 10.4 ± 8.7 months. Disease was ocular in 32% (12 of 37), orbital in 57% (21 of 37), and metastatic in 11% (4 of 37). Of those with ocular disease, 67% (8 of 12) completed chemotherapy and all (8 of 8) achieved remission. In contrast, 48% (10 of 21) with orbital disease completed chemotherapy and only 50% (5 of 10) achieved remission. The difference in outcome between the groups was statistically significant (P = .001, Fisher exact test). CONCLUSION: The profile of retinoblastoma in Tanzania is skewed toward severe invasive disease. Despite the introduction of chemotherapy, further improvements in mortality and morbidity can only be achieved through emphasis on early detection
External Review of Portfolios in Preservice Teacher Education: Studying Our Own Practice.
In this article we present the results of a study in which we examine our use of literacy portfolios in our elementary education methods courses through the inclusion of an external reviewer in the portfolio evaluation process. Preservice teachers at the University of Wisconsin-La Crosse are concurrently enrolled in a field-based block of three professional elementary education courses. They are required to create a literacy portfolio as a combined requirement in our two methods courses (Elementary Level Reading and Curriculum and Methods in Language Arts) in which they demonstrate and reflect upon the development of their knowledge and skills as literacy educators. Our one-semester study provided an external professional audience for the review of these literacy portfolios, and provided us new insights to improve the ways in which we evaluated these assessments
Feral goats in south-western Queensland: a permanent component of the grazing lands
Feral goats were harvested in south-western Queensland at four sites under two regimes (opportunistic harvesting and sustained control). We assessed how this impacted on their contribution to total grazing pressure, on soil and pasture conditions and on the economics of goat management. The population impact was not consistent across sites with the same treatment, with 62% and 84% reductions in numbers in the two northern sites (one opportunistic harvesting site and one sustained control site) while numbers in the southern sites essentially remained the same. The contribution of goats to grazing pressure ranged from 3 to 30%; kangaroos contributed 16–36%; and livestock contributed 37–72%. Harvest rates of feral goats calculated for each of the sites ranged from 17 to 41%. There was no consistent relationship between population changes and the harvest rates. Seasonal conditions had greater influence on pasture and soil conditions than did changes in feral goat populations. The average cost of mustering goats (based on 34 operations) was 2.08 per head. This compared with on-farm prices of 25 per head in 1997. Personal circumstances and preferences of individual landholders were the key determinant of the level of control undertaken. Variability in price contributed to landholders being apprehensive about the viability of the goat industry. There are few simple tools available for landholders to estimate feral goat numbers and this makes effective management of total grazing pressure difficult
Survival of Hendra Virus in the Environment: Modelling the Effect of Temperature
Hendra virus (HeV), a highly pathogenic zoonotic paramyxovirus recently emerged from bats, is a major concern to the horse industry in Australia. Previous research has shown that higher temperatures led to lower virus survival rates in the laboratory. We develop a model of survival of HeV in the environment as influenced by temperature. We used 20 years of daily temperature at six locations spanning the geographic range of reported HeV incidents to simulate the temporal and spatial impacts of temperature on HeV survival. At any location, simulated virus survival was greater in winter than in summer, and in any month of the year, survival was higher in higher latitudes. At any location, year-to-year variation in virus survival 24 h post-excretion was substantial and was as large as the difference between locations. Survival was higher in microhabitats with lower than ambient temperature, and when environmental exposure was shorter. The within-year pattern of virus survival mirrored the cumulative within-year occurrence of reported HeV cases, although there were no overall differences in survival in HeV case years and non-case years. The model examines the effect of temperature in isolation; actual virus survivability will reflect the effect of additional environmental factor
Survival of Hendra Virus in the Environment: Modelling the Effect of Temperature
Hendra virus (HeV), a highly pathogenic zoonotic paramyxovirus recently emerged from bats, is a major concern to the horse industry in Australia. Previous research has shown that higher temperatures led to lower virus survival rates in the laboratory. We develop a model of survival of HeV in the environment as influenced by temperature. We used 20 years of daily temperature at six locations spanning the geographic range of reported HeV incidents to simulate the temporal and spatial impacts of temperature on HeV survival. At any location, simulated virus survival was greater in winter than in summer, and in any month of the year, survival was higher in higher latitudes. At any location, year-to-year variation in virus survival 24 h post-excretion was substantial and was as large as the difference between locations. Survival was higher in microhabitats with lower than ambient temperature, and when environmental exposure was shorter. The within-year pattern of virus survival mirrored the cumulative within-year occurrence of reported HeV cases, although there were no overall differences in survival in HeV case years and non-case years. The model examines the effect of temperature in isolation; actual virus survivability will reflect the effect of additional environmental factor
- …