2,601 research outputs found
Few layer graphene on SiC, pyrolitic graphite and graphene: a Raman scattering study
The results of micro-Raman scattering measurements performed on three
different ``graphitic'' materials: micro-structured disks of highly oriented
pyrolytic graphite, graphene multi-layers thermally decomposed from carbon
terminated surface of 4H-SiC and an exfoliated graphene monolayer are
presented. Despite its multi-layer character, most parts of the surface of the
graphitized SiC substrates shows a single-component, Lorentzian shape, double
resonance Raman feature in striking similarity to the case of a single graphene
monolayer. Our observation suggests a very weak electronic coupling between
graphitic layers on the SiC surface, which therefore can be considered to be
graphene multi-layers with a simple (Dirac-like) band structure.Comment: 4 pages, 3 Figures Structure of the paper strongly modified, small
changes in Fig 2 and 3. Same interpretation and same result
Field-Tuning of the electron and hole populations in the ruthenate Bi_3Ru_3O_11
Experiments on the Hall coefficient R_H and heat capactity C reveal an
unusual, compensated electronic ground state in the ruthenate Bi_3Ru_3O_11. At
low temperature T, R_H decreases linearly with magnetic field |H| for fields
larger than the field scale set by the Zeeman energy. The results suggest that
the electron and hole populations are tuned by H in opposite directions via
coupling of the spins to the field. As T is decreased below 5 K, the curve
C(T)/T vs. T^2 shows an anomalous flattening consistent with a rapidly growing
Sommerfeld parameter \gamma(T). We discuss shifts of the electron and hole
chemical potentials by H to interpret the observed behavior of R_H.Comment: 5 pages, 6 figures, reference adde
Quadrupole transitions near interface: general theory and application to atom inside a planar cavity
Quadrupole radiation of an atom in an arbitrary environment is investigated
within classical as well as quantum electrodynamical approaches. Analytical
expressions for decay rates are obtained in terms of Green function of Maxwell
equations. The equivalence of both approaches is shown. General expressions are
applied to analyze the quadrupole decay rate of an atom placed between two half
spaces with arbitrary dielectric constant. It is shown that in the case when
the atom is close to the surface, the total decay rate is inversely
proportional to the fifth power of distance between an atom and a plane
interface.Comment: 18 pages, 7 figure
Andreev reflections on Y1-xCaxBa2Cu3O7-delta evidence for an unusual proximity effect
We have measured Andreev reflections between an Au tip and
Y_{1-x}Ca_{x}Ba_{2}Cu_{3}O_{7 - \delta} thin films in the in-plane orientation.
The conductance spectra are best fitted with a pair potential having the
"d_{x^{2}-y^{2}+is" symmetry. We find that the amplitude of the "is" component
is enhanced as the contact transparency is increased. This is an indication for
an unusual proximity effect that modifies the pair potential in the
superconductor near the surface with the normal metal.Comment: 4 pages, 4 figure
Gender, war and militarism: making and questioning the links
The gender dynamics of militarism have traditionally been seen as straightforward, given the cultural mythologies of warfare and the disciplining of âmasculinityâ that occurs in the training and use of men's capacity for violence in the armed services. However, women's relation to both war and peace has been varied and complex. It is women who have often been most prominent in working for peace, although there are no necessary links between women and opposition to militarism. In addition, more women than ever are serving in many of today's armies, with feminists rather uncertain on how to relate to this phenomenon. In this article, I explore some of the complexities of applying gender analyses to militarism and peace work in sites of conflict today, looking most closely at the Israeli feminist group, New Profile, and their insistence upon the costs of the militarized nature of Israeli society. They expose the very permeable boundaries between the military and civil society, as violence seeps into the fears and practices of everyday life in Israel. I place their work in the context of broader feminist analysis offered by researchers such as Cynthia Enloe and Cynthia Cockburn, who have for decades been writing about the âmasculinistâ postures and practices of warfare, as well as the situation of women caught up in them. Finally, I suggest that rethinking the gendered nature of warfare must also encompass the costs of war to men, whose fundamental vulnerability to psychological abuse and physical injury is often downplayed, whether in mainstream accounts of warfare or in more specific gender analysis. Feminists need to pay careful attention to masculinity and its fragmentations in addressing the topic of gender, war and militarism
Inclusivity in Action: Interprofessional Curricula Integrates Two-Step Question for Sex and Gender Identity
Background: Identifcation of sex and gender identity is the first step to inclusive care for sex and gender minorities, and studies have shown that health care providers may make heteronormative assumptions about sex and gender. Implemented in 2007, the Jefferson Health Mentors Program (JHMP) involves firstand second-year students from couple and family therapy, human genetics and genetic counseling, medical laboratory sciences, medicine, nursing, occupational therapy, pharmacy, physical therapy, and physician assistant studies. In the First assignment, 140 student teams complete a comprehensive questionnaire, the Individual Life and Wellness History with their Health Mentor. Health Mentors live with one or more chronic conditions and range in age from 27 to 95 years old, with the majority over age 50. Interprofessional education where students learn from, with, and about each other is an ideal place for students to be exposed to the sex and gender two-step question.
Objectives: To describe our experience with 713 students involved in the JHMP asking the two-step sex and gender question.
Methods/Research: In Fall 2018, the two-step sex and gender question was added to the questionnaire. The module evaluation included both a quantitative and a qualitative question to gather student feedback on the inclusion of the two-step sex and gender questions. The qualitative responses were reviewed for themes, and the authors came to consensus.
Conclusions/Impact: Common themes included student appreciation of the importance of the questions; confusion of the Health Mentors with the questions; student perception of generational differences, and student teams having no issues with the questions. No Health Mentors dropped out of the program after the First assignment, other than those who dropped out for health related reasons. Interprofessional education can provide a venue for normalizing the two-step sex and gender question.https://jdc.jefferson.edu/sexandgenderhealth/1000/thumbnail.jp
A comparative DFT study of electronic properties of 2H-, 4H- and 6H-SiC(0001) and SiC(000-1) clean surfaces: Significance of the surface Stark effect
Electric field, uniform within the slab, emerging due to Fermi level pinning
at its both sides is analyzed using DFT simulations of the SiC surface slabs of
different thickness. It is shown that for thicker slab the field is nonuniform
and this fact is related to the surface state charge. Using the electron
density and potential profiles it is proved that for high precision simulations
it is necessary to take into account enough number of the Si-C layers. We show
that using 12 diatomic layers leads to satisfactory results. It is also
demonstrated that the change of the opposite side slab termination, both by
different type of atoms or by their location, can be used to adjust electric
field within the slab, creating a tool for simulation of surface properties,
depending on the doping in the bulk of semiconductor. Using these simulations
it was found that, depending on the electric field, the energy of the surface
states changes in a different way than energy of the bulk states. This
criterion can be used to distinguish Shockley and Tamm surface states. The
electronic properties, i.e. energy and type of surface states of the three
clean surfaces: 2H-, 4H-, 6H-SiC(0001), and SiC() are analyzed and
compared using field dependent DFT simulations.Comment: 18 pages, 10 figures, 4 table
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