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Non-linear finite element calculations are indispensable when important information of the material response under load of a rubber component is desired. Although the material characterization of a rubber component is a demanding engineering task, the changing contact range between the parts and the incompressibility behaviour of the rubber further increase the complexity of the investigations. In this paper the effects of the choice of the numerical material parameters (e.g. bulk modulus) are examined with regard to numerical stability, mesh density and calculation accuracy. As an example, a rubber spring is chosen where contact problem is also handled.

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Background and aims

Over the last decade, worldwide smartphone usage has greatly increased. Alongside this growth, research on the influence of smartphones on human behavior has also increased. However, a growing number of studies have shown that excessive use of smartphones can lead to detrimental consequences in a minority of individuals. This study examines the psychological aspects of smartphone use particularly in relation to problematic use, narcissism, anxiety, and personality factors.

Methods

A sample of 640 smartphone users ranging from 13 to 69 years of age (mean = 24.89 years, SD = 8.54) provided complete responses to an online survey including modified DSM-5 criteria of Internet Gaming Disorder to assess problematic smartphone use, the Spielberger State-Trait Anxiety Inventory, the Narcissistic Personality Inventory, and the Ten-Item Personality Inventory.

Results

The results demonstrated significant relationships between problematic smartphone use and anxiety, conscientiousness, openness, emotional stability, the amount of time spent on smartphones, and age. The results also demonstrated that conscientiousness, emotional stability, and age were independent predictors of problematic smartphone use.

Conclusion

The findings demonstrate that problematic smartphone use is associated with various personality factors and contributes to further understanding the psychology of smartphone behavior and associations with excessive use of smartphones.

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Abstract

Th17 cells, a class of CD4+ T cells, have been identified as novel effector cells, which play a pivotal role in several inflammatory and autoimmune diseases. 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3), the active form of vitamin D, has emerged as a direct regulator of immune system function in humans. Accumulating reports demonstrated that 1,25(OH)2D3 possessed anti-inflammatory activity on Th17 cells to maintain immunologic homeostasis. This report will review the novel immune regulatory role of 1,25(OH)2D3 in its potential use for Th17 cell-related inflammatory and autoimmune conditions.

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Abstract  

Surface treatment on non-ferrous metals are proposed in order to minimize or determine quantitatively the interference of gaseous contamination. These proposals result from a large number of determinations of superficial contamination on several materials using microanalysis by nuclear reactions. This work is included in a larger program which aims the certification of standard materials in their oxygen, nitrogen and carbon contents.

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Abstract  

Polycrystalline titanium samples were oxidized in pure oxygen under a 75 torr pressure, at temperatures ranging from 400°C to 500°C, and for times up to 2 hrs. A similar treatment was applied to some single crystal samples, so as to show the relationship between the crystallite orientation and the oxidation rate. The oxide films were studied by means of radioanalytical techniques, such as nuclear microanalysis, electron diffraction and ESCA, in addition to most classical techniques such as optical and electron microscopy. The complementary side of these methods is showed. They permit us to determine the contamination of the metallic surface introduced by the polishing treatments, the oxidation rate at constant temperature, and the structure of the oxides which exists in the films. These ones are especially TiO2, Ti3O5, Ti2O3 and TiO.

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Abstract

We argue that the creation of new knowledge is both difficult and rare. More specifically, we posit that the creation of new knowledge is dominated by a few key insights that challenge the way people think about an idea; generating high interest and use. We label this the blockbuster hypothesis. Using two large samples of published management studies over the period 1998–2007 we find support for the blockbuster hypothesis. We also find that numerous studies in the leading management journals are flops, having little impact on the profession as measured using citation data. Additional tests indicate that journal “quality” is related to the ratio of blockbusters to flops a journal publishes and that journal rankings are a poor proxy for study influence. Consistent with the notion that editorial boards are able to identify new knowledge, we find that research notes significantly under-perform articles in both the same journal and articles published in lower ranked journals. Taken together, the results imply that only a few scientific studies, out of the thousands published in a given area, change or influence the boundaries of knowledge, with many appearing to have little impact on the frontiers of knowledge. Overall, this analysis indicates that the development of new knowledge is rare even though it appears to be recognizable to knowledge gatekeepers like journal editors.

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Abstract  

The polyoxotungstate K19[U2KAs4W40O140].42H2O was synthesized and investigated by spectroscopic and magnetic susceptibility measurements. The IR spectrum of the complex contains the nas(U–O)»1133 cm–1 band due to the uranium coordination at {AsW9} units and WO6 binding octahedra. Electronic spectra indicate a 3H4 ground state for the uranium(IV) in a quasicubic configuration. ESR spectra show a small orthorhombic distortion from the cubic symmetry (g x = 2.045, g y = 2.050, g z = 2.085, D = 18.31.10–4 .cm–1, E = 5.99.10–4 .cm–1). The uranium ions are antiferromagnetically coupled for T>200 K (meff = 1.3 mB at room temperature).

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Summary  

Six sandwich-type uranium(IV)-polyoxometalates (UIV-POM) were prepared and investigated by FT-IR and UV-VIS spectroscopy. Changes in position and shape of antisymmetric stretching vibration bands in the 640-1000 cm-1 region were identified in all UIV-POM FT-IR spectra. These changes are related to coordination of U(IV) to the trilacunary Keggin units. Visible electronic spectra of aqueous solutions of UIV-POM complexes correspond to uranium 3H4 electronic ground state, having a quasicubic configuration. Presence of electronic transitions were identified by UV spectroscopy of UIV-POM complexes in aqueous solutions.

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Abstract  

New complexes CuL22H2O, CoL23H2O, MnL22H2O and FeL32H2O, L=γ-L -glutamyl-5-(p-nitroanilide), were synthesized and characterized by their spectral, magnetic and thermal properties. The thermal stabilities of the synthesized complexes were examined in the temperature range 20–500C. In all these complexes γ-L -glutamyl-5-(p -nitroanilide) acts as a bidentate ligand, its coordination involving the carbonyl oxygen and the nitrogen atom of the second amino group. The local structure around the Cu(II) ion is pseudotetrahedral. In the Co(II), Mn(II) and Fe(III) complexes, the metal ions are in the high-spin form, with octahedral stereochemistry.

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