Phase diagram for a Bose-Einstein condensate moving in an optical lattice

The stability of superfluid currents in a system of ultracold bosons was studied using a moving optical lattice. Superfluid currents in a very weak lattice become unstable when their momentum exceeds 0.5 recoil momentum. Superfluidity vanishes already for zero momentum as the lattice deep reaches the Mott insulator(MI) phase transition. We study the phase diagram for the disappearance of superfluidity as a function of momentum and lattice depth between these two limits. Our phase boundary extrapolates to the critical lattice depth for the superfluid-to-MI transition with 2% precision. When a one-dimensional gas was loaded into a moving optical lattice a sudden broadening of the transition between stable and unstable phases was observed.Comment: 4 figure

Performance Metrics for the Objective Assessment of Capacitive Deionization Systems

In the growing field of capacitive deionization (CDI), a number of performance metrics have emerged to describe the desalination process. Unfortunately, the separation conditions under which these metrics are measured are often not specified, resulting in optimal performance at minimal removal. Here we outline a system of performance metrics and reporting conditions that resolves this issue. Our proposed system is based on volumetric energy consumption (Wh/m$^3$) and throughput productivity (L/h/m$^2$) reported for a specific average concentration reduction, water recovery, and feed salinity. To facilitate and rationalize comparisons between devices, materials, and operation modes, we propose a nominal standard testing condition of removing 5 mM from a 20 mM NaCl feed solution at 50% water recovery for CDI research. Using this separation, we compare the desalination performance of a flow-through electrode (fte-CDI) cell and a flow between membrane (fb-MCDI) device, showing how significantly different systems can be compared in terms of generally desirable desalination characteristics. In general, we find that performance analysis must be considered carefully so to not allow for ambiguous separation conditions or the maximization of one metric at the expense of another. Additionally, for context we discuss a number of important underlying performance indicators and cell characteristics that are not performance measures in and of themselves but can be examined to better understand differences in performance

The Stability of Double White Dwarf Binaries Undergoing Direct Impact Accretion

We present numerical simulations of dynamically unstable mass transfer in a double white dwarf binary with initial mass ratio, q = 0.4. The binary components are approximated as polytropes of index n = 3/2 and the initially synchronously rotating, semi-detached equilibrium binary is evolved hydrodynamically with the gravitational potential being computed through the solution of Poisson's equation. Upon initiating deep contact in our baseline simulation, the mass transfer rate grows by more than an order of magnitude over approximately ten orbits, as would be expected for dynamically unstable mass transfer. However, the mass transfer rate then reaches a peak value, the binary expands and the mass transfer event subsides. The binary must therefore have crossed the critical mass ratio for stability against dynamical mass transfer. Despite the initial loss of orbital angular momentum into the spin of the accreting star, we find that the accretor's spin saturates and angular momentum is returned to the orbit more efficiently than has been previously suspected for binaries in the direct impact accretion mode. To explore this surprising result, we directly measure the critical mass ratio for stability by imposing artificial angular momentum loss at various rates to drive the binary to an equilibrium mass transfer rate. For one of these driven evolutions, we attain equilibrium mass transfer and deduce that effectively q_crit has evolved to approximately 2/3. Despite the absence of a fully developed disk, tidal interactions appear effective in returning excess spin angular momentum to the orbit.Comment: 27 pages, 6 figures. Please see http://www.phys.lsu.edu/faculty/tohline/astroph/mftd07/ for animations and full resolution figures. Accepted for publication in the Astrophysical Journa

The impact of prior physical conditioning in initial recruit training success: A systematic review

Aim: To determine whether recruits who underwent a physical conditioning program prior to initial tactical training had increased rates of success.Design: Systematic ReviewMethod: A systematic search, following the PRISMA protocol and registered in the Open Science Framework, was conducted to identify relevant studies. Keywords, derived from three themes (physical conditioning, tactical, and recruits), were employed in the search of database CINAHL, ProQuest, PubMed, Scopus, SportDiscus, and Web of Science. Studies were screened against inclusion/exclusion criteria with data extracted and analyzed. The Joanna Briggs Institute critical appraisal tools were used to assess methodological quality of included studies by two authors independently with a Kappa analysis to determine inter-rater agreement.Results: Of 14,411 identified articles, 13 studies informed the review. The mean quality of studies was considered ‘good’ with a Kappa of 0.81 between raters. Seven studies identified that an increase in physical fitness, through use of preconditioning programs, resulted in lower rates of injury. Three studies attributed increased basic training pass rates to physical conditioning programs. However, three studies failed to find a change in attrition rates following the programs.Conclusion: The volume of evidence suggests that programs aimed at increasing muscular conditioning and aerobic endurance prior to tactical training would result in fewer injuries and increased pass rates although reductions in absolute attrition may not change.Key Practice Points:• Recruits are less likely to be injured if they are fitter and / or have completed additional training prior to completing training for a tactical occupation

Perceptions of Discrimination Among Persons With Serious Mental Illness

Objectives: The authors sought to gain further perspective on discrimination experienced by persons with mental illness by comparing self-reports of discrimination due to mental illness to self-reports of discrimination due to other group characteristics, such as race, gender, and sexual orientation. Methods: A total of 1,824 persons with serious mental illness who participated in a baseline interview for a multistate study on consumer-operated services completed a two-part discrimination questionnaire. The first part of the questionnaire assessed participants\u27 perceptions about discrimination due to mental illness as well as more than half a dozen other group characteristics. The second part of the questionnaire asked participants who reported some experience with discrimination to identify areas in which this discrimination occurred, such as employment, education, and housing. Results: More than half of the study participants (949 participants, or 53 percent) reported some experience with discrimination. The most frequent. sources of this discrimination were mental disability, race, sexual orientation, and physical disability. Areas in which discrimination frequently occurred included employment, housing, and interactions with law enforcement. Areas in which discrimination was experienced did not significantly differ among groups of study participants characterized by mental disability, race, gender, sexual orientation, or physical disability. Conclusions: Discrimination based on group characteristics other than mental illness does not diminish the impact of stigma associated with mental illness. Antistigma programs need to target not only discrimination related to mental illness but also that associated with other group characteristics, such as race, gender, sexual orientation, and physical disability

Nanographene Aerogels: Size Effect of the Precursor Graphene Oxide on Gelation Process and Electrochemical Properties

Improving the electrochemical properties of graphene aerogels (GAs) without doping or making composites is an attractive synthetic strategy. In this work we report on the effects of graphene sheet dimensions on GAs. Nanographene aerogels (nG-AGs) were synthesized using nanographene oxide (nGO) powder with a mean platelet diameter of 90 nm. In-situ Fourier transform infrared spectroscopy (FTIR) during gelation revealed a longer fast gelation regime for nG-AGs than for stdG-AGs. The surface-area-normalized capacitance of nG-AGs calculated from cyclic voltammetry is 16% higher than that of stdG-AGs, and the onset of hydrogen evolution is observed at a lower over-potential. These observations can be attributed to increased edge sites and defects in nanographene sheets. Our results imply that the diameter of the precursor graphene sheets can be used as a parameter to optimize the electrochemical properties of graphene AGs depending on the application

Nanographene Aerogels: Size Effect of the Precursor Graphene Oxide on Gelation Process and Electrochemical Properties

Improving the electrochemical properties of graphene aerogels (GAs) without doping or making composites is an attractive synthetic strategy. In this work we report on the effects of graphene sheet dimensions on GAs. Nanographene aerogels (nG-AGs) were synthesized using nanographene oxide (nGO) powder with a mean platelet diameter of 90 nm. In-situ Fourier transform infrared spectroscopy (FTIR) during gelation revealed a longer fast gelation regime for nG-AGs than for stdG-AGs. The surface-area-normalized capacitance of nG-AGs calculated from cyclic voltammetry is 16% higher than that of stdG-AGs, and the onset of hydrogen evolution is observed at a lower over-potential. These observations can be attributed to increased edge sites and defects in nanographene sheets. Our results imply that the diameter of the precursor graphene sheets can be used as a parameter to optimize the electrochemical properties of graphene AGs depending on the application

Internal derangement of the knee in physically demanding occupations: A rapid review

Aim: To identify and review studies reporting on occupational risk factors for the occurrence of internal derangement of the knee (IDK) in physically demanding occupations.Design: Systematic review of the literature.Method: This review was guided by the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. A comprehensive search of seven databases was performed using terms derived from three concepts: ‘risk’, ‘paid occupations’, and ‘IDK’.Results: One article met the eligibility criteria. Findings revealed that male Turkish military personnel with IDK that was secondary to anterior cruciate ligament (ACL) ruptures, managed without reconstruction, and who continued their regular military duties following ACL rupture, had a high prevalence of additional intra- articular lesions. A moderate positive correlation was found between the time from the initial ACL rupture and the presence of at least one additional intra-articular lesion (rs = 0.574; p = 0.0001). Additionally, individuals aged 30 years and older were at slightly greater risk than their younger peers.Conclusion: These findings suggest that the occupational demands to which Turkish military personnel are exposed are associated with IDK developing and worsening over time after ACL rupture as military duties continue.</div

The effects of early physiotherapy treatment on musculoskeletal injury outcomes in military personnel: A narrative review

The risks and incidence rates of musculoskeletal injuries among military personnel are high, and the importance of physiotherapy in treating these injuries is well established. However, what is less clear is whether the timing of commencement of physiotherapy treatment affects musculoskeletal injury outcomes in military personnel. This lack of clarity is exacerbated by the known underreporting of injuries among military personnel, and the resulting self-management of musculoskeletal injuries using analgesics, non-steroidal anti-inflammatories and other means. This narrative review was designed to identify and synthesize current evidence regarding the effects of timing of physiotherapy treatment on musculoskeletal injury outcomes, focusing on potential benefits of early versus typical or delayed commencement of physiotherapy treatment. Overall, current evidence suggests early physiotherapy treatment of musculoskeletal injuries offers distinct advantages over typical or delayed commencement of physiotherapy treatment in military settings. Specifically, it appears early treatment expedites recovery in early phases following injury onset and benefits longer term mental health and well-being. It may also reduce the need for more invasive and costly health care interventions and enable earlier return to training and operational service. Importantly, a cultural shift within military contexts to ensure early reporting of musculoskeletal injuries is required if the benefits of early commencement of physiotherapy treatment are to be achieved