Electron-phonon interaction in transition metal diborides TB_2 (T=Zr, Nb, Ta) studied by point-contact spectroscopy

The electron-phonon interaction (EPI) in transition metal diborides TB_2 (T=Zr, Nb, Ta) is investigated by point-contact (PC) spectroscopy. The PC EPI functions were recovered and the EPI parameters lambda<0.1 were estimated for all three compounds. Common and distinctive features between the EPI functions for those diborides are discussed also in connection with the superconductivity in MgB_2.Comment: V2: minor changes, Ref.[21] added, publ. in PR

Modifying the Recess Before Lunch Program: A Pilot Study in Kaneohe Elementary School

Moving recess before lunch (RBL), though a simple schedule change, may provide many benefits for both students and elementary schools. Having recess before lunch has been shown to decrease plate waste (Bergman, et al., 2003; Gettlinger, 1996; Montana OPI, 2003; Ruppenthal &amp; Hogue, 1977), and may improve discipline problems. The RBL schedule change has not previously been implemented in Hawai‘i schools. The purpose of this pilot study was to assess the feasibility of implementing a modified version of RBL into elementary schools in Hawai‘i . The modified version of RBL allows for implementation into a three-bell lunch system, a system used by many elementary schools in Hawai‘i. A one-grade-per-lunch period RBL switch was assessed among 6th grade students for 1) shorter lunch line wait, 2) increased access to recess equipment 3) decrease in conduct-related referrals, and 4) moderate decrease in food and milk waste for the affected grade(s). Results indicate a significant decrease in lunch line wait, a decrease in discipline referrals, and a slight non-significant decrease in lunch waste. Additional comments from administrators and teaching staff indicate positive changes in student behavior on the playground, in the cafeteria, and in the classroom. One major finding was the reduction in discipline problems after the implementation of RBL, as seen in both the quantitative referral counts and qualitative teacher and administrator questionnaires. The positive results of this study support further implementation of RBL into schools in Hawai‘i. Kaneohe Elementary School has continued to apply recess before lunch to the sixth grade lunch periods and is considering further implementation into other grades. The Hawai‘i Action for Healthy Kids team plans to approach more schools in Hawai‘i about using the modified recess before lunch program

Optical detection of spin transport in non-magnetic metals

We determine the dynamic magnetization induced in non-magnetic metal wedges composed of silver, copper and platinum by means of Brillouin light scattering (BLS) microscopy. The magnetization is transferred from a ferromagnetic Ni80Fe20 layer to the metal wedge via the spin pumping effect. The spin pumping efficiency can be controlled by adding an insulating but transparent interlayer between the magnetic and non-magnetic layer. By comparing the experimental results to a dynamical macroscopic spin-transport model we determine the transverse relaxation time of the pumped spin current which is much smaller than the longitudinal relaxation time

Metacognitive Performance, the Tip-of-Tongue Experience, Is Not Disrupted in Parkinsonian Patients

The present study investigated whether a form of metamemory, the tip-of-tongue phenomenon (TOT), was affected in patients with Parkinson's disease (PD). The PD patient (n = 22), age-matched elderly control (n = 22), and college student control (n = 46) groups were compared on a motor timing task and TOT measures. Motor timing was assessed using a cued hand-clapping task, whereas TOT was assessed using general knowledge questions. The results indicated that motor timing was significantly impaired in the PD group relative to both control groups. However, all of the TOT metacognitive measures: frequency, strength, and accuracy were statistically equivalent between the PD patients and elderly control groups, both of whom showed significantly better memory performance than college controls. These findings demonstrate that TOT metamemory is not compromised in PD patients, and that further insight into TOT mechanisms in PD may prove helpful in developing novel intervention strategies to enhance memory and general cognitive functions in these patients

Large, high quality single-crystals of the new Topological Kondo Insulator, SmB6

SmB6 has recently been predicted to be a Topological Kondo Insulator, the first strongly correlated heavy fermion material to exhibit topological surface states. High quality crystals are necessary to investigate the topological properties of this material. Single crystal growth of the rare earth hexaboride, SmB6, has been carried out by the floating zone technique using a high power xenon arc lamp image furnace. Large, high quality single-crystals are obtained by this technique. The crystals produced by the floating zone technique are free of contamination from flux materials and have been characterised by resistivity and magnetisation measurements. These crystals are ideally suited for the investigation of both the surface and bulk properties of SmB6

Resistivity due to a Domain Wall in Ferromagnetic Metal

The resistivity due to a domain wall in ferromagnetic metallic wire is calculated based on the linear response theory. The interaction between conduction electrons and the wall is expressed in terms of a classical gauge field which is introduced by the local gauge transformation in the electron spin space. It is shown that the wall contributes to the decoherence of electrons and that this quantum correction can dominate over the Boltzmann resisitivity, leading to a decrease of resisitivity by nucleation of a wall. The conductance fluctuation due to the motion of the wall is also investigated. The results are compared with recent experiments.Comment: 9 pages, 3 figure