Sarma Phase in Trapped Unbalanced Fermi Gases

We consider a trapped unbalanced Fermi gas at nonzero temperatures where the superfluid Sarma phase is stable. We determine in particular the phase boundaries between the superfluid, normal, and phase separated regions of the trapped unbalanced Fermi mixture. We show that the physics of the Sarma phase is sufficient to understand the recent observations of Zwierlein et al. [Science 311, 492 (2006); Nature 442, 54 (2006)] and indicate how the apparent contradictions between this experiment and the experiment of Partridge et al. [Science 311, 503 (2006)] may be resolved.Comment: Replaced with published version; 4 pages, 3 figure

Resonant Superfluidity in an Optical Lattice

We study a system of ultracold fermionic Potassium (40K) atoms in a three-dimensional optical lattice in the vicinity of an s-wave Feshbach resonance. Close to resonance, the system is described by a multi-band Bose-Fermi Hubbard Hamiltonian. We derive an effective lowest-band Hamiltonian in which the effect of the higher bands is incorporated by a self-consistent mean-field approximation. The resulting model is solved by means of Generalized Dynamical Mean-Field Theory. In addition to the BEC/BCS crossover we find a phase transition to a fermionic Mott insulator at half filling, induced by the repulsive fermionic background scattering length. We also calculate the critical temperature of the BEC/BCS-state and find it to be minimal at resonance.Comment: 19 pages, 3 figure

A thermionic energy converter with a molybdenum-alumina cermet emitter

A study is made of the properties of cermets as electrode materials for thermionic energy converters. For thermodynamic reasons it is expected that all cermets composed of pure Mo and refractory oxides have the same bare work function. From data on the work function of Mo in an oxygen atmosphere this bare work function is estimated to be F=4.9 eV (at T=1400¿°C). Experimentally, the bare work function of Al2O3-Mo cermets was found to be F=4.5 eV, independent of the relative amounts of Al2O3 and Mo. The cesiated work function of the Al2O3-Mo cermets was found to be 0.15 eV lower than the cesiated work function of pure Mo. The bare work function of Mo3Al was found to be F=4.0 eV. The cesiated work function of Mo3Al at collector temperature conditions was 0.3 eV lower than the cesiated work function of pure Mo. The electrical power density of a diode with an Al2O3-Mo cermet emitter was 0.4 W/cm2 at 1300¿°C. The barrier index at this temperature was 2.36 V. The high barrier index is attributed to a high plasma voltage drop Vd=0.91 V

An analysis of the morphology and submarine landslide potential of the upper and middle continental slope offshore Fraser Island, Queensland, Australia

This study presents an investigation into the geomorphological, sedimentological and geotechnical properties of submarine landslides present on the continental slope offshore Fraser Island. An extensive range of previously undiscovered features including marginal plateaus, linear rills, ridges and gullies, canyon systems, as well as slides and slumps were identified. Gravity cores (5.65 m and 3.64 m long) taken in the ‘Upper Slope Slide’ (25 km2 in area, 200-300 m thick), and the ‘Middle Slope Slide’ (11 km2 in area, 100-150 m thick) indicate the slide scars contain drapes of Pleistocene to Recent hemipelagic mud. Shorter gravity cores (1.33 m and 0.43 m long) taken adjacent to both slides terminated in stiff muds of upper Pliocene to lower Pleistocene age (Upper Slope Slide), and upper Miocene to lower Pliocene age (Middle Slope Slide). This unique pattern shows that the sediment is being accumulated and protected inside the slide hollows, while being actively removed from the exposed adjacent slopes, most likely by abrasion. Biostratigraphic ages determined for the basal material demonstrate that the seafloor surfaces at both sites are effectively erosional unconformities. The basal, stiff sediments on the upper slope was deposited between 2 and 2.5 Ma BP; this material was scoured and then buried beneath a 1 m thick sediment drape at 0.45 Ma BP. Sediments exposed on the seafloor adjacent to the Middle Slope Slide were dated at around 6-8.5 Ma BP. This indicates that the smooth upper continental slope developed its morphology by the late-mid Pleistocene, while the middle slope is a Post-Pliocene feature. It is thought that Pliocene-Pleistocene geological events including fluctuations in the intensity of surface and abyssal ocean currents are responsible for re-sculpting the continental slope’s morphology and have a) increased abrasion and erosion of the middle and upper slope; while b) suppressed sediment delivery

What Works in School-Based Programs for Child Abuse Prevention? The Perspectives of Young Child Abuse Survivors

Previous research has shown that youth consider school-based child abuse prevention programs as one of the most important strategies for preventing child abuse and neglect. This study asked young child abuse survivors how school-based child abuse prevention programs should be shaped and what program components they perceive as essential. Semi-structured interviews were conducted with 13 Dutch young adults that were a victim of child abuse or neglect. A literature review that resulted in 12 potential program components was used to guide the interviews. All young adults agreed that school-based child abuse prevention programs are important and have positive effects on children’s awareness of child abuse. Teaching children that they are never to blame for child abuse occurrences was considered one of the most important components of school-based programs, next to teaching children how to escape from threatening situations and to find help, increasing children’s social–emotional skills, promoting child abuse related knowledge, recognizing risky situations, and increasing children’s self-esteem. Further, the participants found it important to provide children with aftercare when a school program has ended. Overall, young child abuse survivors have a strong view on what should be addressed in school-based child abuse prevention programs to effectively prevent child abuse