848 research outputs found

    Upgrade of SULTAN/EDIPO for HTS Cable Test

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    AbstractCRPP hosts two unique conductor test facilities SULTAN (SUpraLeiter TestANlage) and EDIPO (European DIPOle). They allow the test of high current superconductors in high magnetic fields (SULTAN 11 T, EDIPO 12.5 T). In both facilities sample currents up to 100 kA can be supplied by means of a NbTi transformer. Presently the facilities are upgraded for the test of high current high-temperature superconductor (HTS) samples. For HTS conductor testing at temperatures between 20 and 50K, the heat flux between the HTS sample under test and the NbTi transformer needs to be limited to around 10W per conductor leg by means of an HTS adapter connecting them. The second required upgrade is the supply of intermediate temperature helium (20-50 K) to the HTS test conductor. It is mandatory that the helium gas coming from the HTS conductor under test can be returned to the cryoplant as cold gas (T < 20K). To reach this goal a tube-in-tube heat exchanger has been manufactured in which 4.5K helium coming from the cryoplant is in counter flow with the warm gas leaving the HTS test conductor

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    With a Little Help from my Friends: Acculturation and Mental Health in Arabic-speaking Refugee Youth Living with their Families

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    Introduction: Refugee youth are often faced with the compounding challenges of heightened exposure to traumatic events and acculturating to a new country during a developmental period when their sense of self is still forming. This study investigated whether refugee youth’s acculturation orientation (separation, integration, marginalization, and assimilation) is associated with depressive and posttraumatic stress symptoms and aimed to identify additional indicators of acculturation that may contribute to mental health. Methods: A total of 101 Arabic-speaking refugee youths (aged 14–20 years), who were living with their families and attending school in Germany, took part in the study. They answered questions concerning traumatic exposure and posttraumatic stress symptoms, depressive symptoms, and several indicators of acculturation, including cultural orientation, positive and negative intra- and intergroup contact, language skills and friendship networks. All participants were categorized into one of four acculturation orientations using median splits. Results: Kruskal–Wallis rank sum tests revealed that acculturation orientation was not significantly associated with depressive symptoms [χ2 (3, 97) = 0.519, p = 0.915] or posttraumatic stress symptoms [χ2 (3, 97) = 0.263, p = 0.967]. Regression analysis revealed that German language skills were significantly associated with lower scores of depressive symptoms (p = 0.016) and number of friends in Germany was significantly associated with lower scores of depressive (p = 0.006) and posttraumatic stress symptoms (p = 0.002), respectively. Discussion: Policies that provide refugee youth with access to language classes and social activities with peers do not only enable them to actively participate in a new society but may also have a positive effect on their mental health

    Money in monetary policy design: monetary cross-checking in the New-Keynesian model

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    In the New-Keynesian model, optimal interest rate policy under uncertainty is formulated without reference to monetary aggregates as long as certain standard assumptions on the distributions of unobservables are satisfied. The model has been criticized for failing to explain common trends in money growth and inflation, and that therefore money should be used as a cross-check in policy formulation (see Lucas (2007)). We show that the New-Keynesian model can explain such trends if one allows for the possibility of persistent central bank misperceptions. Such misperceptions motivate the search for policies that include additional robustness checks. In earlier work, we proposed an interest rate rule that is near-optimal in normal times but includes a cross-check with monetary information. In case of unusual monetary trends, interest rates are adjusted. In this paper, we show in detail how to derive the appropriate magnitude of the interest rate adjustment following a significant cross-check with monetary information, when the New-Keynesian model is the central bank’s preferred model. The cross-check is shown to be effective in offsetting persistent deviations of inflation due to central bank misperceptions. Keywords: Monetary Policy, New-Keynesian Model, Money, Quantity Theory, European Central Bank, Policy Under Uncertaint

    Optimisation of ITER Nb3Sn CICCs for coupling loss, transverse electromagnetic load and axial thermal contraction

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    The ITER cable-in-conduit conductors (CICCs) are built up from sub-cable bundles, wound in different stages, which are twisted to counter coupling loss caused by time-changing external magnet fields. The selection of the twist pitch lengths has major implications for the performance of the cable in the case of strain sensitive superconductors, i.e. Nb3Sn, as the electromagnetic and thermal contraction loads are large but also for the heat load from the AC coupling loss. Reduction of the transverse load and warm-up cool-down degradation can be reached by applying longer twist pitches in a particular sequence for the sub-stages, offering a large cable transverse stiffness, adequate axial flexibility and maximum allowed lateral strand support. Analysis of short sample (TF conductor) data reveals that increasing the twist pitch can lead to a gain of the effective axial compressive strain of more than 0.3 % with practically no degradation from bending. For reduction of the coupling loss, specific choices of the cabling twist sequence are needed with the aim to minimize the area of linked strands and bundles that are coupled and form loops with the applied changing magnetic field, instead of simply avoiding longer pitches. In addition we recommend increasing the wrap coverage of the CS conductor from 50 % to at least 70 %. The models predict significant improvement against strain sensitivity and substantial decrease of the AC coupling loss in Nb3Sn CICCs, but also for NbTi CICCs minimization of the coupling loss can be achieved. Although the success of long pitches to transverse load degradation was already demonstrated, the prediction of the combination with low coupling loss needs to be validated by a short sample test.Comment: to be published in Supercond Sci Techno

    Cytosolic chaperones influence the fate of a toxin dislocated from the endoplasmic reticulum

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    The plant cytotoxin ricin enters target mammalian cells by receptor-mediated endocytosis and undergoes retrograde transport to the endoplasmic reticulum (ER). Here, its catalytic A chain (RTA) is reductively separated from the cell-binding B chain, and free RTA enters the cytosol where it inactivates ribosomes. Cytosolic entry requires unfolding of RTA and dislocation across the ER membrane such that it arrives in the cytosol in a vulnerable, nonnative conformation. Clearly, for such a dislocated toxin to become active, it must avoid degradation and fold to a catalytic conformation. Here, we show that, in vitro, Hsc70 prevents aggregation of heat-treated RTA, and that RTA catalytic activity is recovered after chaperone treatment. A combination of pharmacological inhibition and cochaperone expression reveals that, in vivo, cytosolic RTA is scrutinized sequentially by the Hsc70 and Hsp90 cytosolic chaperone machineries, and that its eventual fate is determined by the balance of activities of cochaperones that regulate Hsc70 and Hsp90 functions. Cytotoxic activity follows Hsc70-mediated escape of RTA from an otherwise destructive pathway facilitated by Hsp90. We demonstrate a role for cytosolic chaperones, proteins typically associated with folding nascent proteins, assembling multimolecular protein complexes and degrading cytosolic and stalled, cotranslocational clients, in a toxin triage, in which both toxin folding and degradation are initiated from chaperone-bound states

    Gladstone Harbour Fish Health Investigation 2011-2012

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    The Gladstone Harbour Fish Health Investigation occurred in response to public concerns regarding fish health in Gladstone Harbour, which were raised with the former Department of Employment, Economic Development and Innovation (now Department of Agriculture, Fisheries and Forestry (DAFF)) in August 2011. The majority of concerns were regarding skin redness, lesions and eye damage observed on barramundi caught from the Boyne River or within its vicinity. Further reports included unusual skin redness and occasional lesions observed on a range of fish species from Gladstone Harbour (including sharks), as well as an increase in the incidence of shell erosion on mud crabs. The subsequent investigation aimed to determine the cause of the reported issues and specifically to address public concern regarding the potential impact of industrial activity including dredging in Gladstone Harbour. The investigation, conducted by DAFF, was part of a whole-of-government response, which included sediment and water quality testing; and investigation into human health concerns. The first reports of abnormalities in fish were received months after a major flood event happened in Gladstone from December 2010 until early 2011. The flood event caused a dramatic influx of large barramundi (estimated 30 000), as well as other species from Lake Awoonga into the Boyne River when the Awoonga Dam spilled over. The dam had not spilled over since the 1990s, well before the dam wall was raised in 2002. Many of these fish were injured (some fatally) from the force of the impact when passing over the spillway. It is believed that a smaller number of fish were washed over during a second flood event in early 2012. The initial response investigated fish with visible abnormalities (e.g. missing scales and redness), and signs of disease to indicate the cause of the observed issues. This early sampling (Phase 1) between August 2011 and February 2012 was based on observations of commercial fishing activity, contracted fish surveys and submissions by members of the public. Over 5000 fish, crustaceans and molluscs were visually assessed during this sampling. In January 2012, the Independent Gladstone Fish Health Scientific Advisory Panel released a report recommending a structured sampling program to gauge fish health in Gladstone Harbour sites against comparable unaffected sites (reference sites), through time. It also recommended the development of a conceptual model of possible cause-effect relationships to help guide studies and eliminate potential causal factors. Structured sampling in Gladstone Harbour (Phase 2) was conducted in two major surveys during April–May (Trip 1) and June–July (Trip 2) 2012. These surveys covered 11 sites including two reference sites and focussed on a subset of 10 species. The selected species represented a range of different life cycles (e.g. catadromous and estuarine) and trophic levels (e.g. predatory, omnivorous detritivores and scavengers), and had been reported with a variety of abnormalities. A third targeted survey was conducted in September 2012 to monitor potential seasonal reoccurrence of parasitic infestations in the barramundi from the Boyne River. A total of 3699 fish and crustaceans were visually assessed in the field, with 452 specimens examined by necropsy, and tissues from 120 specimens subjected to histopathology and chemical residue testing

    Cytosolic chaperones influence the fate of a toxin dislocated from the endoplasmic reticulum

    Get PDF
    The plant cytotoxin ricin enters target mammalian cells by receptor-mediated endocytosis and undergoes retrograde transport to the endoplasmic reticulum (ER). Here, its catalytic A chain (RTA) is reductively separated from the cell-binding B chain, and free RTA enters the cytosol where it inactivates ribosomes. Cytosolic entry requires unfolding of RTA and dislocation across the ER membrane such that it arrives in the cytosol in a vulnerable, nonnative conformation. Clearly, for such a dislocated toxin to become active, it must avoid degradation and fold to a catalytic conformation. Here, we show that, in vitro, Hsc70 prevents aggregation of heat-treated RTA, and that RTA catalytic activity is recovered after chaperone treatment. A combination of pharmacological inhibition and cochaperone expression reveals that, in vivo, cytosolic RTA is scrutinized sequentially by the Hsc70 and Hsp90 cytosolic chaperone machineries, and that its eventual fate is determined by the balance of activities of cochaperones that regulate Hsc70 and Hsp90 functions. Cytotoxic activity follows Hsc70-mediated escape of RTA from an otherwise destructive pathway facilitated by Hsp90. We demonstrate a role for cytosolic chaperones, proteins typically associated with folding nascent proteins, assembling multimolecular protein complexes and degrading cytosolic and stalled, cotranslocational clients, in a toxin triage, in which both toxin folding and degradation are initiated from chaperone-bound states
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