9,132 research outputs found

    FMR Study of Co/Ti Bilayer Thin Films

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    . We focused on the interaction between two ferromagnetic cobalt layers through a non-magnetic titanium layer. The magnetic properties of the structure were characterized by ferromagnetic resonance technique (FMR). The data were collected as a function of non-magnetic titanium layer thickness. Co/Ti multilayer (Ti (50 {\AA})/Co(45 {\AA})/Ti(2-40 {\AA})/Co(40 {\AA})/Ti(100 {\AA}))films were grown onto naturally oxidized p-type single crystal Si (100) substrate at UHV condition with magnetron sputtering system at room temperature. The thickness of Ti spacer layer ranges from 2 to 40 {\AA} with 2 {\AA} steps. We did not observe usual optic and acoustic modes; instead we had two broad overlapped peaks for the films ranged from 6 {\AA} to 40 {\AA}. One interesting result was the high anisotropic resonance field values for these films. Exchange coupling between ferromagnetic layers causes shift on resonance field values but these shifts in our samples were much larger than expected. This large anisotropic behavior is not clear at the moment. Our theoretical model was not able to determine a value for the exchange coupling parameter. One reason can be the close thickness values for Co sublayers. The other reason can be the Ti non-magnetic layer. If titanium did not grow layer by layer on cobalt, the cobalt ferromagnetic layers may behave as a single layer. As a result one cannot observe exchange interaction between ferromagnetic layers through non-magnetic spacer.Comment: 6 pages, 5 figure

    Gay male academics in UK business and management schools: negotiating heteronormativities in everyday work life

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    This paper contributes to a neglected topic area about lesbian, gay, bisexual and trans people’s employment experiences in UK business and management schools. Drawing on queer theory to problematize essentialist notions of sexuality, we explore how gay male academics negotiate and challenge discourses of heteronormativity within different work contexts. Using in-depth interview data, the paper shows that gay male academics are continually constrained by heteronormativity in constructing viable subject positions as ‘normal’, often having to reproduce heteronormative values that squeeze opportunities for generating non-heteronormative ‘queer’ sexualities, identities and selves. Constructing a presence as an openly gay academic can invoke another binary through which identities are (re)constructed: as either ‘gay’ (a cleaned up version of gay male sexuality that sustains a heteronormative moral order) or ‘queer’ (cast as radical, disruptive and sexually promiscuous). Data also reveal how gay men challenge organizational heteronormativities through teaching and research activities, producing reverse discourses and creating alternative knowledge/power regimes, despite institutional barriers and risks of perpetuating heteronormative binaries and constructs. Study findings call for pedagogical and research practices that ‘queer’ (rupture, destabilize, disrupt) management knowledge and the heterosexual/homosexual binary, enabling non-heteronormative voices, perspectives, identities and ways of relating to emerge in queer(er) business and management schools

    p53 mutation as a source of aberrant β-catenin accumulation in cancer cells

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    β-catenin is involved in both cell-cell interactions and wnt pathway-dependent cell fate determination through its interactions with E-cadherin and TCF/LEF transcription factors, respectively. Cytoplasmic/nuclear levels of β-catenin are important in regulated transcriptional activation of TCF/LEF target genes. Normally, these levels are kept low by proteosomal degradation of β-catenin through Axin1- and APC-dependent phosphorylation by CKI and GSK-3β. Deregulation of β-catenin degradation results in its aberrant accumulation, often leading to cancer. Accordingly, aberrant accumulation of β-catenin is observed at high frequency in many cancers. This accumulation correlates with either mutational activation of CTNNB1 (β-catenin) or mutational inactivation of APC and Axin1 genes in some tumors. However, there are many tumors that display β-catenin accumulation in the absence of a mutation in these genes. Thus, there must be additional sources for aberrant β-catenin accumulation in cancer cells. Here, we provide experimental evidence that wild-type β-catenin accumulates in hepatocellular carcinoma (HCC) cells in association with mutational inactivation of p53 gene. We also show that worldwide p53 and β-catenin mutation rates are inversely correlated in HCC. These data suggest that inactivation of p53 is an important cause of aberrant accumulation of β-catenin in cancer cells

    The Novel Control Loops of the Pulsed Power Converters for the CERN SPS Machine

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    The topic of this paper is the studies that were made in the framework of the renovation project of the CERN SPS accelerator's power converters. This project was initiated because these converters were designed 20 years ago and they will need to work another 20 years, due to the use of the SPS machine as the LHC injector

    Microwave-induced nonequilibrium temperature in a suspended carbon nanotube

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    Antenna-coupled suspended single carbon nanotubes exposed to 108 GHz microwave radiation are shown to be selectively heated with respect to their metal contacts. This leads to an increase in the conductance as well as to the development of a power-dependent DC voltage. The increased conductance stems from the temperature dependence of tunneling into a one-dimensional electron system. The DC voltage is interpreted as a thermovoltage, due to the increased temperature of the electron liquid compared to the equilibrium temperature in the leads

    Comparisons of environmental effects and productivity by road construction machines in forest areas in Turkey

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    In this study, forest road construction techniques, environmental damages, cross sections and productivity by using hydraulic excavator and bulldozer were investigated in forested lands in Antalya and Eskisehir region in Turkey. Maximum length of fill slope for bulldozer and excavator were found 17 m on 80% slope gradient and 11 m on same slope gradient, respectively. The costs of forest roads for bulldozer and excavator were calculated to be 21.8 US dollars/m and 8.5 US dollars/m, respectively. Productivity of bulldozer and excavator were found to be 105.8 and 66.2 m3/h, respectively. The types of environmental damages on trees were determined and found to be wounded, bending and crushing. In this study, 23% of trees under the forest road construction by excavator are damaged and 40% of trees by bulldozer are damaged for 45 - 90% ground slope.Key words: Hydraulic excavator, bulldozer, forest road, road construction, environmental damage, construction cost

    Glyphosate reduced seed and leaf concentrations of calcium, manganese, magnesium, and iron in non-glyphosate resistant soybean

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    Greenhouse experiments were conducted to study the effects of glyphosate drift on plant growth and concentrations of mineral nutrients in leaves and seeds of non-glyphosate resistant soybean plants (Glycine max, L.). Glyphosate was sprayed on plant shoots at increasing rates between 0.06 and 1.2% of the recommended application rate forweed control. In an experiment with 3-week-old plants, increasing application of glyphosate on shoots significantly reduced chlorophyll concentration of the young leaves and shoots dry weight, particularly the young parts of plants. Concentration of shikimate due to increasing glyphosate rates was nearly 2-fold for older leaves and 16-fold for younger leaves compared to the control plants without glyphosate spray. Among the mineral nutrients analyzed, the leaf concentrations of potassium (K), phosphorus (P), copper (Cu) and zinc (Zn) were not affected, or even increased significantly in case of P and Cu in young leaves by glyphosate, while the concentrations of calcium (Ca), manganese (Mn) and magnesium (Mg) were reduced, particularly in young leaves. In the case of Fe, leaf concentrations showed a tendency to be reduced by glyphosate. In the second experiment harvested at the grain maturation, glyphosate application did not reduce the seed concentrations of nitrogen (N), K, P, Zn and Cu. Even, at the highest application rate of glyphosate, seed concentrations of N, K, Zn and Cuwere increased by glyphosate. By contrast, the seed concentrations of Ca, Mg, Fe and Mn were significantly reduced by glyphosate. These results suggested that glyphosatemay interfere with uptake and retranslocation of Ca, Mg, Fe and Mn, most probably by binding and thus immobilizing them. The decreases in seed concentration of Fe, Mn, Ca and Mg by glyphosate are very specific, and may affect seed quality
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