1,522 research outputs found
Geometric dependence of Nb-BiTe-Nb topological Josephson junction transport parameters
Superconductor-topological insulator-superconductor Josephson junctions have
been fabricated in order to study the width dependence of the critical current,
normal state resistance and flux periodicity of the critical current modulation
in an external field. Previous literature reports suggest anomalous scaling in
topological junctions due to the presence of Majorana bound states. However,
for most realised devices, one would expect that trivial -periodic
Andreev levels dominate transport. We also observe anomalous scaling behaviour
of junction parameters, but the scaling can be well explained by mere geometric
effects, such as the parallel bulk conductivity shunt and flux focusing
Vortex trapping and expulsion in thin-film YBCO strips
A scanning SQUID microscope was used to image vortex trapping as a function
of the magnetic induction during cooling in thin-film YBCO strips for strip
widths W from 2 to 50 um. We found that vortices were excluded from the strips
when the induction Ba was below a critical induction Bc. We present a simple
model for the vortex exclusion process which takes into account the vortex -
antivortex pair production energy as well as the vortex Meissner and
self-energies. This model predicts that the real density n of trapped vortices
is given by n=(Ba-BK)/Phi0 with BK = 1.65Phi0/W^2 and Phi0 = h/2e the
superconducting flux quantum. This prediction is in good agreement with our
experiments on YBCO, as well as with previous experiments on thin-film strips
of niobium. We also report on the positions of the trapped vortices. We found
that at low densities the vortices were trapped in a single row near the
centers of the strips, with the relative intervortex spacing distribution width
decreasing as the vortex density increased, a sign of longitudinal ordering.
The critical induction for two rows forming in the 35 um wide strip was (2.89 +
1.91-0.93)Bc, consistent with a numerical prediction
Dynamics Among Borderline Personality and Anxiety Features in Psychotherapy Outpatients: An Exploration of Nomothetic and Idiographic Patterns
Borderline personality disorder (BPD) involves instability in self-concept, emotions, and behavior. However, the dynamic, longitudinal relations among BPD symptoms and between these symptoms and other problematic emotional experiences are poorly understood. It is also unclear whether these dynamics are the same across persons (including across diagnostic boundaries), specific to individuals with BPD, or idiographic. The current study uses ecological momentary assessment and Group Iterative Multiple Model Estimation (GIMME), a novel, data-driven approach to identifying dynamic patterns in time-series data at group, subgroup, and individual levels, to investigate the dynamic connections among select features of BPD (anger, impulsivity, and identity disturbance) and anxiety-related experiences. Forty-two psychiatric outpatients diagnosed with BPD (n = 27) or with an anxiety disorder, but not BPD (n = 15) rated their anger, identity disturbance, impulsivity, anxiety, stress, and calmness states six times per day for 21 days, providing a total of 4,699 surveys. Only one dynamic link between symptoms was identified that applied at the group level, and GIMME did not reveal stable subgroups of individuals with distinct symptom dynamics. Instead, these dynamics differed from individual to individual. These results suggest that connections among these BPD and anxiety symptoms do not depend on diagnosis and are somewhat idiographic. Case examples are used to illustrate the clinical utility of within-person symptom models as a supplement to traditional diagnostic information
Changes in supportive care needs over time from diagnosis up to two years after treatment in head and neck cancer patients:A prospective cohort study
Objectives: To investigate changes in supportive care needs (SCNs) over time from diagnosis up to 2 years after treatment among head and neck cancer (HNC) patients, in relation to demographic, personal, clinical, psychological, physical, social, lifestyle, and cancer-related quality of life factors.Materials and methods: Data of the longitudinal NETherlands QUality of Life and Biomedical Cohort study (NET-QUBIC) was used. SCNs were measured using the Supportive Care Needs Survey (SCNS-SF34) and HNC-specific module (SCNS–HNC) before treatment, three, six, 12 and 24 months after treatment. Linear mixed model analyses were used to study SCNs on the physical & daily living (PDL), psychological (PSY), sexuality (SEX), health system, information and patient support (HSIPS), HNC-functioning (HNC-Function), and lifestyle (HNC-Lifestyle) domain, in relation to demographic, personal, clinical, psychological, physical, social, lifestyle, and cancer-related symptoms as measured at baseline.Results: In total, 563 patients were included. SCNs changed significantly over time. At baseline, 65% had ≥1 moderate/high SCN, versus 42.8% at 24 months. Changes in PDL needs were associated with gender, tumor location, smoking, fear of cancer recurrence, oral pain, and appetite loss, changes in PSY with tumor location, fear of recurrence, social support, emotional functioning, physical functioning, coughing, and use of painkillers, changes in SEX with treatment, changes in HSIPS with muscle strength, changes in HNC-Function with tumor stage, location, social support, physical functioning, fatigue, nausea and vomiting, and speech problems, and changes in HNC-Lifestyle with smoking and alcohol use.Conclusion: SCNs diminish over time, but remain prevalent in HNC patients.</p
Theory for the electromigration wind force in dilute alloys
A multiple scattering formulation for the electromigration wind force on
atoms in dilute alloys is developed. The theory describes electromigration via
a vacancy mechanism. The method is used to calculate the wind valence for
electromigration in various host metals having a close-packed lattice
structure, namely aluminum, the noble metals copper, silver and gold and the
transition metals. The self-electromigration results for aluminum and the
noble metals compare well with experimental data. For the metals small
wind valences are found, which make these metals attractive candidates for the
experimental study of the direct valence.Comment: 18 pages LaTeX, epsfig, 8 figures. to appear in Phys. Rev. B 56 of
15/11/199
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