5,737 research outputs found

    A mathematical model of fluid flow in a scraped-surface heat exchanger

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    A simple mathematical model of fluid flow in a common type of scraped-surface heat exchanger in which the gaps between the blades and the device walls are narrow, so that a lubrication-theory description of the flow is valid, is presented. Specifically steady isothermal flow of a Newtonian fluid around a periodic array of pivoted scraper blades in a channel with one stationary and one moving wall, when there is an applied pressure gradient in a direction perpendicular to the wall motion, is analysed. The flow is three-dimensional, but decomposes naturally into a two-dimensional "transverse" flow driven by the boundary motion and a "longitudinal" pressure-driven flow. First details of the structure of the transverse flow are derived, and, in particular, the equilibrium positions of the blades are calculated. It is shown that the desired contact between blades and the moving wall will be attained, provided that the blades are pivoted sufficiently close to their ends. When the desired contact is achieved, the model predicts that the forces and torques on the blades are singular, and so the model is generalised to include three additional physical effects, namely non-Newtonian power-law behaviour, slip at rigid boundaries, and cavitation in regions of very low pressure, each of which is shown to resolve these singularities. Lastly the nature of the longitudinal flow is discussed

    Creation and redemption in Isaiah 40-55

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    Isaiah 40-55 offer a fertile ground for the study of the interaction between the two biblical motifs of creation and redemption. Whereas von Rad’s thesis of creation being subordinated to salvation is no longer acceptable, the two are still taken to be one and the same act of YHWH (Rendtorf f/Ilermisson) , with salvation understood as a new creation overcoming YHWH’s judgement (Harner/Haag), and proclaimed as a transforming wonder in a universal context (Stuhlmueller).Our re-examination of 27 pericopae from four basic genres in Isaiah 40-55 shows that the predominant theme is YHWH’s sovereignty. The disputations depict YHWH as both creator of the cosmos and lord of history in contrast to the idols dependent on human workmanship. A second group of disputations, which includes the so- called trial speeches against Israel, stresses YHWH’s faithfulness despite Israel’s sinfulness. The exile does not signify YHWH ’ s defeat; it is the judgement of the same sovereign God. The trial speeches argue for YHWH’s incomparability on the ground of his control over past and present events as witnessed by Israel. By contrast the idols are impotent and unable to help. The salvation oracles portray YHWH as the creator of both his own people and the enemies. The connotation of power instead of novelty or intimacy in the creation language is substantiated by our survey of the use of &?’"Q (br ’ ) inthe Hebrew Bible, Similarly, the description of YHWH as redeemer not only points to divine forgiveness, but also involves the demonstration of YHWH’s power in Babylon’s downfall and Zion’s restoration. Theophanic imagery of the transformation of nature is used in the salvation promises to illustrate YHWH’s supreme sovereignty, and his 'hidden’ act through Cyrus’ victory is finally acknowledged by the nations. The macro-palistrophic structure of these 16 chapters confirms that the crisis of faith during the exile lies in the challenge of the pagan imperial powers to YHWH’s sovereignty.Based on the present study, further research on the unity of the book of Isaiah and the interplay of the two motifs of creation and salvation in other poetic books (the Psalter and Job) is called for. Meanwhile, our understanding of the doctrine of creation should not be governed by the legacy of creatio ex nihilo, and our interpretation of soteriology must give equal emphasis to both dimensions of reconciliation and liberation

    Pyrometry inside an arc furnace using a ray-tracing correction for surface emissivity

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    Domain-mediated interactions for protein subfamily identification

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    Within a protein family, proteins with the same domain often exhibit different cellular functions, despite the shared evolutionary history and molecular function of the domain. We hypothesized that domain-mediated interactions (DMIs) may categorize a protein family into subfamilies because the diversified functions of a single domain often depend on interacting partners of domains. Here we systematically identified DMI subfamilies, in which proteins share domains with DMI partners, as well as with various functional and physical interaction networks in individual species. In humans, DMI subfamily members are associated with similar diseases, including cancers, and are frequently co-associated with the same diseases. DMI information relates to the functional and evolutionary subdivisions of human kinases. In yeast, DMI subfamilies contain proteins with similar phenotypic outcomes from specific chemical treatments. Therefore, the systematic investigation here provides insights into the diverse functions of subfamilies derived from a protein family with a link-centric approach and suggests a useful resource for annotating the functions and phenotypic outcomes of proteins.11Ysciescopu

    Structural and magnetic study of a dilute magnetic semiconductor: Fe doped CeO2 nanoparticles

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    This paper reports the effect of Fe doping on the structure and room temperature ferromagnetism of CeO2 nanoparticles. X-ray diffraction and selective area electron diffraction measurement reflects that Ce1-xFexO2 (x = 0.0 - 0.07) nanoparticles exhibit single phase nature with cubic structure and none of the sample showed the presence of any secondary phase. The mean particle size calculated by using a transmission electron microscopy measurement was found to increase with increase in Fe content. DC magnetization measurements performed at room temperature indicates that all the samples exhibit ferromagnetism. The saturation magnetic moment has been found to increase with an increase in the Fe content.Comment: 16 Pages, 5 figure, 1 Table, Accepted in JN

    An immunohistochemical study of the pancreatic endocrine cells of the Korean golden frog, Rana plancyi chosenica

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    The regional distribution and quantitative frequency of pancreatic endocrine cells were demonstrated in the Korean golden frog (Rana plancyi chosenica Okada), which is known as a Korean endemic species, for the first time by immunohistochemical methods using specific mammalian antisera to insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). In the pancreas of the Korean golden frog, all four endocrine cell types were demonstrated. Insulin- and glucagon-positive cells were located in the pancreas as single cells or islet-like clusters, respectively. Somatostatin-containing cells were also dispersed in the pancreas as single cells or clusters but in the case of clusters, they are exclusively situated in the marginal regions of insulin- or glucagon-positive cell clusters. PP-containing cells were also distributed as single cells or clusters. Clusters consisted of PP-positive cells are distributed as a core type and a marginally distributed type. Overall, there were 40.84±3.81% insulin-, 26.02±1.71% glucagon-, 7.63±2.09% somatostatin- and 25.51±3.26% PP-IR cells

    Effective scraping in a scraped surface heat exchanger: some fluid flow analysis

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    An outline of mathematical models that have been used to understand the behaviour of scraped surface heat exchangers is presented. In particular the problem of the wear of the blades is considered. A simple model, exploiting known behaviour of viscous flow in corners and in wedges, and accounting for the forces on the blade is derived and solutions generated. The results shows initial rapid wear but that the wear rate goes to zero

    Trauma-focused treatments for depression. A systematic review and meta-analysis

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    Background Trauma-focused treatments (TFTs) have demonstrated efficacy at decreasing depressive symptoms in individuals with PTSD. This systematic review and meta-analysis evaluated the effectiveness of TFTs for individuals with depression as their primary concern. Methods A systematic search was conducted for RCTs published before October 2019 in Cochrane CENTRAL, Pubmed, EMBASE, PsycInfo, and additional sources. Trials examining the impact of TFTs on participants with depression were included. Trials focusing on individuals with PTSD or another mental health condition were excluded. The primary outcome was the effect size for depression diagnosis or depressive symptoms. Heterogeneity, study quality, and publication bias were also explored. Results Eleven RCTs were included (n = 567) with ten of these using EMDR as the TFT and one using imagery rescripting. Analysis suggested these TFTs were effective in reducing depressive symptoms post-treatment with a large effect size [d = 1.17 (95% CI: 0.58~ 1.75)]. Removal of an outlier saw the effect size remain large [d = 0.83 (95% CI: 0.48~ 1.17)], while the heterogeneity decreased (I2 = 66%). Analysis of the 10 studies that used EMDR also showed a large effect [d = 1.30 (95% CI: 0.67~1.91)]. EMDR was superior to non trauma-focused CBT [d = 0.66 (95% CI: 0.31~1.02)] and analysis of EMDR and imagery rescripting studies suggest superiority over inactive control conditions [d = 1.19 (95% CI: 0.53~ 1.86)]. Analysis of follow-up data also supported the use of EMDR with this population [d = 0.71 (95% CI: 1.04~0.38)]. No publication bias was identified. Conclusions Current evidence suggests that EMDR can be an effective treatment for depression. There were insufficient RCTs on other trauma-focused interventions to conclude whether TFTs in general were effective for treating depression. Larger studies with robust methodology using EMDR and other trauma-focused interventions are needed to build on these findings

    Bogomol'nyi equations for solitons in Maxwell-Chern-Simons gauge theories with the magnetic moment interaction term

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    Without assuming rotational invariance, we derive Bogomol'nyi equations for the solitons in the abelian Chern-Simons gauge theories with the anomalous magnetic moment interaction. We also evaluate the number of zero modes around a static soliton configuration.Comment: 9 pages, Revtex, SNUTP-94/6
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