On stoichiometry and intermixing at the spinel/perovskite interface in CoFe2O4/BaTiO3 thin films

The performance of complex oxide heterostructures depends primarily on the interfacial coupling of the two component structures. This interface character inherently varies with the synthesis method and conditions used since even small composition variations can alter the electronic, ferroelectric, or magnetic functional properties of the system. The focus of this article is placed on the interface character of a pulsed laser deposited CoFe2O4/BaTiO3 thin film. Using a range of state-of-the-art transmission electron microscopy methodologies, the roles of substrate morphology, interface stoichiometry, and cation intermixing are determined on the atomic level. The results reveal a surprisingly uneven BaTiO3 substrate surface formed after the film deposition and Fe atom incorporation in the top few monolayers inside the unit cell of the BaTiO3 crystal. Towards the CoFe2O4 side, a disordered region extending several nanometers from the interface was revealed and both Ba and Ti from the substrate were found to diffuse into the spinel layer. The analysis also shows that within this somehow incompatible composite interface, a different phase is formed corresponding to the compound Ba2Fe3Ti5O15, which belongs to the ilmenite crystal structure of FeTiO3 type. The results suggest a chemical activity between these two oxides, which could lead to the synthesis of complex engineered interfaces

An overview of R&D work in friction stir welding at SMU

Friction stir welding (FSW) is an innovative solid-state material joining method invented by The Welding Institute (TWI) in 1991 and has been one of the most significant joining technology developments in the last two decades. It has evolved into a process focused on joining arc weldable (5xxx and 6xxx) and unweldable (2xxx and 7xxx) aluminum alloys to a point where it can be implemented by the aerospace and automotive industries for their joining needs.Research towards the further extension of the process to join dissimilar metal combinations like Fe-Al and Al-Cu is currently underway. A few of the important advantages of FSW over conventional joining techniques include improved joint properties and performance, low-deformation of the workpieces, a significant reduction in production costs and the freeing of skilled labor for use in other tasks. Compared to the conventional arc-welding of aluminum alloys, FSW produces a smaller heat affected zone, and it also allows the successful joining of aluminum alloys, steel, titanium, and dissimilar alloys with a stronger joint

Health promoting potential of herbal teas and tinctures from Artemisia campestris subsp maritima: from traditional remedies to prospective products

This work explored the biotechnological potential of the medicinal halophyte Artemisia campestris subsp. maritima (dune wormwood) as a source of health promoting commodities. For that purpose, infusions, decoctions and tinctures were prepared from roots and aerial-organs and evaluated for in vitro antioxidant, anti-diabetic and tyrosinase-inhibitory potential, and also for polyphenolic and mineral contents and toxicity. The dune wormwood extracts had high polyphenolic content and several phenolics were identified by ultra-high performance liquid chromatography-photodiode array-mass-spectrometry (UHPLC-PDA-MS). The main compounds were quinic, chlorogenic and caffeic acids, coumarin sulfates and dicaffeoylquinic acids; several of the identified phytoconstituents are here firstly reported in this A. campestris subspecies. Results obtained with this plant's extracts point to nutritional applications as mineral supplementary source, safe for human consumption, as suggested by the moderate to low toxicity of the extracts towards mammalian cell lines. The dune wormwood extracts had in general high antioxidant activity and also the capacity to inhibit a-glucosidase and tyrosinase. In summary, dune wormwood extracts are a significant source of polyphenolic and mineral constituents, antioxidants and a-glucosidase and tyrosinase inhibitors, and thus, relevant for different commercial segments like the pharmaceutical, cosmetic and/or food industries.FCT - Foundation for Science and Technology [CCMAR/Multi/04326/2013]; Portuguese National Budget; FCT [IF/00049/2012, SFRH/BD/94407/2013]; Research Foundation - Flanders (FWO) [12M8315N]info:eu-repo/semantics/publishedVersio

Measurement of Inclusive B --> psi Production

Using the combined CLEO II and CLEO II.V data sets of 9.1 fb^{-1} at the Upsilon(4S), we measure properties of Psi mesons produced directly from decays of the B meson, where ``B'' denotes an admixture of B+, B-, B0, and B0bar, and ``Psi'' denotes either J/Psi or Psi(2S). We report first measurements of Psi polarization in B -> Psi(direct) X: alpha(J/Psi) = -0.30 {+0.07 -0.06 stat} {+-0.04 syst} and alpha(Psi(2S)) = -0.45 {+0.22 -0.19 stat} {+-0.04 syst}. We also report improved measurements of the momentum distributions of Psi produced directly from B decays, correcting for measurement smearing. Finally, we report measurements of the inclusive branching fraction for B -> Psi X and B -> Chi_c1 X.Comment: 8 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

Search for Lepton-Flavor-Violating Decays of B Mesons

We have searched a sample of 9.6 million BB-bar events for the lepton-flavor-violating decays B --> h e^{+-} mu^{-+}, B^+ --> h^- e^+ e^+, B^+ --> h^- e^+ mu^+, and B^+ --> h^- mu^+ mu^+, where h is pi, K, rho, and K*(892), a total of sixteen modes. We find no evidence for these decays, and place 90% confidence level upper limits on their branching fractions that range from 1.0 to 8.3 X 10^{-6}.Comment: 8 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, PRD R

Hadronic Mass Moments in Inclusive Semileptonic B Meson Decays

We have measured the first and second moments of the hadronic mass-squared distribution in B -> X_c l nu, for P(lepton) > 1.5 GeV/c. We find <M_X^2 - M_D[Bar]^2> = 0.251 +- 0.066 GeV^2, )^2 > = 0.576 +- 0.170 GeV^4, where M_D[Bar] is the spin-averaged D meson mass. From that first moment and the first moment of the photon energy spectrum in b -> s gamma, we find the HQET parameter lambda_1 (MS[Bar], to order 1/M^3 and beta_0 alpha_s^2) to be -0.24 +- 0.11 GeV^2. Using these first moments and the B semileptonic width, and assuming parton-hadron duality, we obtain |V_cb| = 0.0404 +- 0.0013.Comment: 11 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

Measurement of the Masses and Widths of the Sigma_c^++ and Sigma_c^0 Charmed Baryons

Using data recorded by the CLEO II and CLEO II.V detector configurations at CESR, we report new measurements of the masses of the Sigma_c^{++} and Sigma_c^0 charmed baryons, and the first measurements of their intrinsic widths. We find M(Sigma_c^{++}) - M(Lambda_c^+) = 167.4 +- 0.1 +- 0.2 MeV, Gamma(Sigma_c^{++}) = 2.3 +- 0.2 +- 0.3 MeV, and M(Sigma_c^0) - M(Lambda_c^+) = 167.2 +- 0.1 +- 0.2 MeV, Gamma(Sigma_c^0) = 2.5 +- 0.2 +- 0.3 MeV, where the uncertainties are statistical and systematic, respectively.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PRD, Rapid Communications. Reference [13] correcte

Anti-Search for the Glueball Candidate f_J(2220) in Two-Photon Interactions

Using 13.3 fb^{-1} of e^+e^- data recorded with the CLEO II and CLEO II.V detector configurations at CESR, we have searched for f_J(2220) decays to K^0_{S} K^0_{S} in untagged two-photon interactions. We report an upper limit on the product of the two-photon partial width and the branching fraction, Gamma_gamma gamma cdot B (f_J(2220) to K^0_{S} K^0_{S}) of less than 1.1 eV at the 95% C.L: systematic uncertainties are included. This dataset is four times larger than that used in the previous CLEO publication.Comment: 10 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, Submitted to PRD (R

Improved Measurement of the Pseudoscalar Decay Constant fDsf_{D_{s}}

We present a new determination of the Ds decay constant, f_{Ds} using 5 million continuum charm events obtained with the CLEO II detector. Our value is derived from our new measured ratio of widths for Ds -> mu nu/Ds -> phi pi of 0.173+/- 0.021 +/- 0.031. Taking the branching ratio for Ds -> phi pi as (3.6 +/- 0.9)% from the PDG, we extract f_{Ds} = (280 +/- 17 +/- 25 +/- 34){MeV}. We compare this result with various model calculations.Comment: 23 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Measurements of the Mass, total Width and Two-Photon Partila Width of the ηc\eta_{c} Meson

Using 13.4 $fb^{-1}$ of data collected with the CLEO detector at the Cornell Electron Storage Ring, we have observed 300 events for the two-photon production of ground-state pseudo-scalar charmonium in the decay $\eta_c$ -> $K_S K^{\mp} \pi^{\pm}$. We have measured the $\eta_c$ mass to be (2980.4 +- 2.3 (stat) +- 0.6 (sys)) MeV and its full width as (27.0 +- 5.8 (stat) +- 1.4 (sys)) MeV. We have determined the two-photon partial width of the $\eta_c$ meson to be (7.6 +- 0.8 (stat) +- 0.4 (sys) +- 2.3 (br)) keV, with the last uncertainty associated with the decay branching fraction.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN