In the present work, a microwave excited plasma (2·45 GHz, 1 kW) was used to modify the surface characteristics of the ethylene propylene diene monomer rubber. The samples were treated with a mixture ...of nitrogen, hydrogen and argon plasmas. The operating gas pressure was in the 0·2-1 Torr range, the gas flowrate between 5 and 100 sccm and the treatment time varied from 10 to 600 s. The influence of the plasma treatment on the superficial characteristics of the samples was analysed by contact angle measurements and atomic force microscopy. The results show that the plasma treatment can promote an important decrease in the contact angle from 101° for untreated sample to 34° for samples treated in a mixture of H
2
/N
2
/Ar for 2 min, which corresponds an increase on the rubber surface adhesion work from 59 to 133 mJ m
−2
.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Nitrogen doped titanium dioxide (TiO sub(2) thin films were deposited by RF magnetron sputtering onto various substrates. The films were prepared in plasma of argon, oxygen, and nitrogen, with ...varying the nitrogen content, from 0% up to 70%. The resulting TiOx-Ny films were found to consist of cubic TiN osbornite and tetragonal TiO) sub(2) rutile phases. Using optical spectroscopy with large spectral range from 350 to 1000 nm, the band gap width was determined and a narrowing of the optical gap from 2.76 to 2.32 eV was observed as a function of the N-content. It was found that the optical properties of the TiOx-Ny layers are influenced by the surface morphology, roughness, surface energy and phase content. The chemical composition, the crystalline structure, the surface morphology and the surface energy were thoroughly studied by the Rutherford backscattering spectrometry (RBS), grazing-angle XRD, atomic force microscopy (AFM) and contact angle measurements (wettability), respectively.
We present measurements of direct photon pair production cross sections using 8.5fb-1 of data collected with the D0 detector at the Fermilab Tevatron $p\bar{p}$ collider. The results are presented as ...differential distributions of the photon pair invariant mass $dσ/dM_{γγ}$, pair transverse momentum $dσ/dp^{γγ}_{T}$, azimuthal angle between the photons $dσ/dΔφ_{γγ}$, and polar scattering angle in the Collins–Soper frame $dσ/d|cos θ*|$. Measurements are performed for isolated photons with transverse momenta $p^γ_T$ > 18(17)GeV for the leading (next-to-leading) photon in $p_T$, pseudorapidities , |$η^γ$| < 0.9 and a separation in η–φ space Δ$\mathscr{R}_{γγ}$ >0.4. We present comparisons with the predictions from Monte Carlo event generators DIPHOX and RESBOS implementing QCD calculations at next-to-leading order, 2γNNLO at next-to-next-to-leading order, and SHERPA using matrix elements with higher-order real emissions matched to parton shower.
We examine properties of tt¯ candidate events in lepton+jets final states to establish the helicities of W bosons in t→W+b decays. Our analysis is based on a direct calculation of a probability ...density for each event to correspond to a tt¯ final state, as a function of the helicity of the W boson. Using the 125 events/pb of data collected by the DØ experiment at the Fermilab Tevatron pp¯ Collider at s=1.8 TeV, we obtain a longitudinal helicity fraction F0=0.56±0.31, consistent with the prediction of F0=0.70 from the standard model.
We present a search for the standard model Higgs boson in 9.5 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. The final ...state considered contains a pair of b jets and is characterized by an imbalance in transverse energy, as expected from p (p) over bar -> ZH -> nu(nu) over barb (b) over bar production. The search is also sensitive to the WH -> l nu b (b) over bar channel when the charged lepton is not identified. The data are found to be in good agreement with the expected background. For a Higgs boson mass of 125 GeV, we set a limit at the 95% C.L. on the cross section sigma(p (p) over bar -> vertical bar Z/W vertical bar H), assuming standard model branching fractions, that is a factor of 4.3 times larger than the theoretical standard model value, while the expected factor is 3.9. The search is also used to measure a combined WZ and ZZ production cross section that is a factor of 0.94 +/- 0.31 (stat) +/- 0.34 (syst) times the standard model prediction of 4.4 pb, with an observed significance of 2.0 standard deviations. (C) 2012 Elsevier B.V. All rights reserved.
The macroscopic fungi performance a important role in the maintenance of forest environments, and studies related with the identification of species are fundamental to the research progress. This ...study aimed to realize a survey the species diversity of wood decomposing fungi in populations of Pinus elliottii Engelm, Eucalyptus globulus Labill, Acacia mearnsii de Wild and natural forest, in State Foundation for Agricultural Research - FEPAGRO, Forestry Research Center, located in Santa Maria, RS. Were collected 53 samples of macroscopic fungi in four areas, being 16 samples in forest of P. Elliottii; 12 samples in forest of E. globulus, 12 samples in forest of A. mearnsii and 13 samples in of native forest. In the laboratory, five genera were identified to the species level: Fuligo septica (L.) F.H. Wigg, Gloeoporus dichrous (Fr.) Bress., Lycogala epidendrum (L.) Fr. e Trametes villosa (Sw.) Kreisel.
Six studies were conducted to evaluate the persistent efficacy of eprinomectin pour-on against experimental challenges with infective nematode larvae in calves. In each study, calves were randomly ...assigned to one untreated group and up to four test groups, which were treated with eprinomectin at 500 microg/kg body weight at weekly intervals before single bolus challenge. The calves were necropsied approximately 4 weeks after challenge infection for nematode recovery. Eprinomectin pour-on provided > or =90% efficacy against challenge with Haemonchus placei, Trichostrongylus axei and T. colubriformis at 21 days after treatment and against Cooperia oncophora, C. punctata, C. surnabada, Dictyocaulus viviparus, Nematodirus helvetianus, Oesophagostomum radiatum and Ostertagia ostertagi at 28 days after treatment.
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