193 research outputs found
Addiction Recovery Support: Connecting Primary Care Providers and Community Resources
Addiction to drugs and alcohol is a pervasive problem throughout Vermont and the U.S., and only a fraction of those needing help receive it. The vast majority of admissions to substance abuse treatment programs do not come from healthcare providers, who report a lack of preparedness in managing addiction screening and referrals. Recognizing that Family Medicine Providers are likely to be caring for many patients struggling with substance abuse, this project aims to improve provider familiarity with local resources. In particular, this project focuses on promoting long-term retention in self-help group programs, as these have been demonstrated to be the most approachable form of help for many presenting in the primary care setting.https://scholarworks.uvm.edu/fmclerk/1288/thumbnail.jp
Thermodynamic properties of Pb determined from pressure-dependent critical-field measurements
We have carried out extensive low-temperature (1.5 to 10 K) measurements of
the critical field, , for the element Pb up to a pressure of GPa.
From this data the electronic entropy, specific heat, thermal expansion
coefficient and compressibility is calculated as a function of temperature,
pressure and magnetic field. The zero-field data is consistent with direct
thermodynamic measurements and the -dependence of and specific heat
coefficient, allows the determination of the -dependence of
the pairing interaction.Comment: 5 pages, 6 figures, in press Phys. Rev.
Gaps in Adolescent Tobacco Prevention and Counseling in Vermont
Introduction. Tobacco use remains the leading cause of preventable death in Vermont. While the Vermont Blueprint for Health includes compensation for adult tobacco counseling, it includes no specific mention of pediatric populations. Research questions: To what extent are tobacco assessment and cessation efforts occurring in the primary care setting with pediatric patients? What factors influence their practices?Methods. A 12-question electronic survey, modeled on an American Academy of Pediatrics survey, was distributed to primary care providers throughout Vermont; through the UVM departments of pediatrics, family medicine, the Vermont Medical Society and the Vermont Area Health Education Center. We received 70 completed surveys.Results. 70% of the surveyed primary care providers begin tobacco counseling at the age recommended (11 years) by the Vermont Department of Health. Only 45.71% of providers are confident in their understanding of the recommendations for adolescent health screening written in the Blueprint for Health. Additionally, only 67.1% of the providers expressed confidence in their ability to provide guidance regarding the harmful effects of E-cigarettes, compared to 92.8% feeling confident regarding conventional cigarettes. 70% of providers listed time restraints as a significant factor in their decision not to counsel adolescents on tobacco use.Discussion. The Blueprint for Health is a guiding document for provider practices that is not well understood and does not specifically include pediatric tobacco prevention. In an environment where youth E-cigarette use is rising, especially among adolescents, it is especially critical that physicians are confident in their counseling practices.https://scholarworks.uvm.edu/comphp_gallery/1237/thumbnail.jp
Spin-Imbalance and Magnetoresistance in Ferromagnet/Superconductor/Ferromagnet Double Tunnel Junctions
We theoretically study the spin-dependent transport in a ferromagnet/super-
conductor/ferromagnet double tunnel junction. The tunneling current in the
antiferromagnetic alignment of the magnetizations gives rise to a spin
imbalance in the superconductor. The resulting nonequilibrium spin density
strongly suppresses the superconductivity with increase of bias voltage and
destroys it at a critical voltage Vc. The results provide a new method not only
for measuring the spin polarization of ferromagnets but also for controlling
superconductivity and tunnel magnetoresistance (TMR) by applying the bias
voltage.Comment: 4pages, to be published in Phys. Rev. Let
Gate-controlled spin polarized current in ferromagnetic single electron transistors
We theoretically investigate spin dependent transport in ferromagnetic/normal
metal/ferromagnetic single electron transistors by applying master equation
calculations using a two dimensional space of states involving spin and charge
degrees of freedom. When the magnetizations of ferromagnetic leads are in
anti-parallel alignment, the spins accumulate in the island and a difference of
chemical potentials of the two spins is built up. This shift in chemical
potential acts as charge offset in the island and alternates the gate
dependence of spin current. Taking advantage of this effect, one can control
the polarization of current up to the polarization of lead by tuning gate
voltages.Comment: 5 pages, 4 figure
Dynamic exchange coupling and Gilbert damping in magnetic multilayers
We theoretically study dynamic properties of thin ferromagnetic films in
contact with normal metals. Moving magnetizations cause a flow of spins into
adjacent conductors, which relax by spin flip, scatter back into the
ferromagnet, or are absorbed by another ferromagnet. Relaxation of spins
outside the moving magnetization enhances the overall damping of the
magnetization dynamics in accordance with the Gilbert phenomenology. Transfer
of spins between different ferromagnets by these nonequilibrium spin currents
leads to a long-ranged dynamic exchange interaction and novel collective
excitation modes. Our predictions agree well with recent
ferromagnetic-resonance experiments on ultrathin magnetic films.Comment: 15 pages, 3 figures, for MMM'02 proceeding
Spin Polarization and Magneto-Coulomb Oscillations in Ferromagnetic Single Electron Devices
The magneto-Coulomb oscillation, the single electron repopulation induced by
external magnetic field, observed in a ferromagnetic single electron transistor
is further examined in various ferromagnetic single electron devices. In case
of double- and triple-junction devices made of Ni and Co electrodes, the single
electron repopulation always occurs from Ni to Co electrodes with increasing a
magnetic field, irrespective of the configurations of the electrodes. The
period of the magneto-Coulomb oscillation is proportional to the single
electron charging energy. All these features are consistently explained by the
mechanism that the Zeeman effect induces changes of the Fermi energy of the
ferromagnetic metal having a non-zero spin polarizations. Experimentally
determined spin polarizations are negative for both Ni and Co and the magnitude
is larger for Ni than Co as expected from band calculations.Comment: 4 pages, 3 figures, uses jpsj.sty, submitted to J. Phys. Soc. Jp
Current and Spin-Torque in Double Tunnel Barrier Ferromagnet - Superconductor - Ferromagnet Systems
We calculate the current and the spin-torque in small symmetric double tunnel
barrier ferromagnet - superconductor - ferromagnet (F-S-F) systems.
Spin-accumulation on the superconductor governs the transport properties when
the spin-flip relaxation time is longer than the transport dwell time. In the
elastic transport regime, it is demonstrated that the relative change in the
current (spin-torque) for F-S-F systems equals the relative change in the
current (spin-torque) for F-N-F systems upon changing the relative
magnetization direction of the two ferromagnets. This differs from the results
in the inelastic transport regime where spin-accumulation suppresses the
superconducting gap and dramatically changes the magnetoresistance [S.
Takahashi, H. Imamura, and S. Maekawa, Phys. Rev. Lett. 82, 3911 (1999)]. The
experimental relevance of the elastic and inelastic transport regimes,
respectively, as well as the reasons for the change in the transport properties
are discussed.Comment: 7 page
Electric field dependence of thermal conductivity of a granular superconductor: Giant field-induced effects predicted
The temperature and electric field dependence of electronic contribution to
the thermal conductivity (TC) of a granular superconductor is considered within
a 3D model of inductive Josephson junction arrays. In addition to a
low-temperature maximum of zero-field TC K(T,0) (controlled by mutual
inductance L_0 and normal state resistivity R_n), the model predicts two major
effects in applied electric field: (i) decrease of the linear TC, and (ii)
giant enhancement of the nonlinear (i.e., grad T-dependent) TC with
[K(T,E)-K(T,0)]/K(T,0) reaching 500% for parallel electric fields E=E_T
(E_T=S_0|grad T| is an "intrinsic" thermoelectric field). A possiblity of
experimental observation of the predicted effects in granular superconductors
is discussed.Comment: 5 LaTeX pages (jetpl.sty included), 2 EPS figures. To be published in
JETP Letter
Mesoscopic Ferromagnet/Superconductor Junctions and the Proximity Effect
We have measured the electrical transport of submicron ferromagnets (Ni) in
contact with a mesoscopic superconductor (Al) for a range of interface
resistances. In the geometry measured, the interface and the ferromagnet are
measured separately. The ferromagnet itself shows no appreciable
superconducting proximity effect, but the ferromagnet/superconductor interface
exhibits strong temperature, field and current bias dependences. These effects
are dependent on the local magnetic field distribution near the interface
arising from the ferromagnet. We find that the temperature dependences may be
fit to a modified version of the Blonder-Tinkham-Klapwijk theory for
normal-superconductor transport.Comment: 4 eps fig
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