4,534 research outputs found

    Simple, high current LaB_6 cathode

    Get PDF
    A cathode constructed of a thin, directly heated strip of LaB_6 is described. The cathode is simple to construct, requires modest heating power, has high current emission capability and is quite rugged. Construction details will be given and cathode performance data presented. The cathode has been used in tokamak dc current injection experiments

    The fake food buffet - a new method in nutrition behaviour research

    Get PDF
    Experimental research in behavioural nutrition is often limited by practical applicability. In the present study, we assess the reproducibility and validity of a new experimental method using food replicas. A total of fifty-seven people were invited on two separate occasions with an interval of 2 weeks to serve themselves a meal from a fake food buffet (FFB) containing replica carrots, beans, pasta and chicken. The external validity of the FFB was assessed in a second study by comparing meals served from replica foods (beans, pasta, chicken) with meals served from a corresponding real food buffet (RFB). For the second study, forty-eight participants were invited on two separate occasions; first to serve themselves a meal from the FFB or an RFB and 2 weeks later from the other buffet. The amounts of food items served and (theoretical) energy content were compared. Correlation coefficients between the amounts of fake foods served were 0·77 (95% CI 0·68, 0·86) for chicken, 0·79 (95% CI 0·68, 0·87) for carrots, 0·81 (95% CI 0·69, 0·89) for beans and 0·89 (95% CI 0·82, 0·93) for pasta. For the FFB meal and the RFB meal, the correlations ranged between 0·76 (95% CI 0·73, 0·91) for chicken and 0·87 (95% CI 0·77, 0·92) for beans. The theoretical energy of the fake meal was 132kJ (32kcal) lower compared to the energy of the real meal. Results suggest that the FFB can be a valuable tool for the experimental assessment of relative effects of environmental influences on portion sizes and food choice under well-controlled condition

    Infinite Layer LaNiO(2): Ni(1+)is not Cu(2+)

    Full text link
    The Ni ion in LaNiO2_2 has the same formal ionic configuration 3d93d^9 as does Cu in isostructural CaCuO2_2, but it is reported to be nonmagnetic and probably metallic whereas CaCuO2_2 is a magnetic insulator. From ab initio calculations we trace its individualistic behavior to (1) reduced 3d2p3d-2p mixing due to an increase of the separation of site energies (ϵdϵp\epsilon_d - \epsilon_p) of at least 2 eV, and (2) important Ni 3d(3z2r2)3d(3z^2-r^2) mixing with La 5d(3z2r2)5d(3z^2-r^2) states that leads to Fermi surface pockets of La 5d5d character that hole-dope the Ni 3d band.Correlation effects do not appear to be large in LaNiO2_2. However, ad hoc increase of the intraatomic repulsion on the Ni site (using the LDA+U method) is found to lead to a novel correlated state: (i) the transition metal d(x2y2)d(x^2-y^2) and d(3z2r2)d(3z^2-r^2) states undergo consecutive Mott transitions, (ii) their moments are antialigned leading (ideally) to a "singlet" ion in which there are two polarized orbitals, and (iii) mixing of the upper Hubbard 3d(3z2r2)3d(3z^2-r^2) band with the La 5d(xy)5d(xy) states leaves considerable transition metal 3d character in a band pinned to the Fermi level. The magnetic configuration is more indicative of a Ni2+^{2+} ion in this limit, although the actual charge changes little with U.Comment: 7 pages, 8 figure

    Applying the effort-reward imbalance model to household and family work: a population-based study of German mothers

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>This paper reports on results of a newly developed questionnaire for the assessment of effort-reward imbalance (ERI) in unpaid household and family work. Methods: Using a cross-sectional population-based survey of German mothers (n = 3129) the dimensional structure of the theoretical ERI model was validated by means of Confirmatory Factor Analysis (CFA). Analyses of Variance were computed to examine relationships between ERI and social factors and health outcomes.</p> <p>Results</p> <p>CFA revealed good psychometric properties indicating that the subscale 'effort' is based on one latent factor and the subscale 'reward' is composed of four dimensions: 'intrinsic value of family and household work', 'societal esteem', 'recognition from the partner', and 'affection from the child(ren)'. About 19.3% of mothers perceived lack of reciprocity and 23.8% showed high rates of overcommitment in terms of inability to withdraw from household and family obligations. Socially disadvantaged mothers were at higher risk of ERI, in particular with respect to the perception of low societal esteem. Gender inequality in the division of household and family work and work-family conflict accounted most for ERI in household and family work. Analogous to ERI in paid work we could demonstrate that ERI affects self-rated health, somatic complaints, mental health and, to some extent, hypertension.</p> <p>Conclusions</p> <p>The newly developed questionnaire demonstrates satisfied validity and promising results for extending the ERI model to household and family work.</p

    A new ambulatory system for comparative evaluation of the three-dimensional knee kinematics, applied to anterior cruciate ligament injuries

    Get PDF
    The aim of this study was to develop an ambulatory system for the three-dimensional (3D) knee kinematics evaluation, which can be used outside a laboratory during long-term monitoring. In order to show the efficacy of this ambulatory system, knee function was analysed using this system, after an anterior cruciate ligament (ACL) lesion, and after reconstructive surgery. The proposed system was composed of two 3D gyroscopes, fixed on the shank and on the thigh, and a portable data logger for signal recording. The measured parameters were the 3D mean range of motion (ROM) and the healthy knee was used as control. The precision of this system was first assessed using an ultrasound reference system. The repeatability was also estimated. A clinical study was then performed on five unilateral ACL-deficient men (range: 19-36years) prior to, and a year after the surgery. The patients were evaluated with the IKDC score and the kinematics measurements were carried out on a 30m walking trial. The precision in comparison with the reference system was 4.4°, 2.7° and 4.2° for flexion-extension, internal-external rotation, and abduction-adduction, respectively. The repeatability of the results for the three directions was 0.8°, 0.7° and 1.8°. The averaged ROM of the five patients' healthy knee were 70.1° [standard deviation (SD) 5.8°], 24.0° (SD 3.0°) and 12.0° (SD 6.3°) for flexion-extension, internal-external rotation and abduction-adduction before surgery, and 76.5° (SD 4.1°), 21.7° (SD 4.9°) and 10.2° (SD 4.6°) 1year following the reconstruction. The results for the pathologic knee were 64.5° (SD 6.9°), 20.6° (SD 4.0°) and 19.7° (8.2°) during the first evaluation, and 72.3° (SD 2.4°), 25.8° (SD 6.4°) and 12.4° (SD 2.3°) during the second one. The performance of the system enabled us to detect knee function modifications in the sagittal and transverse plane. Prior to the reconstruction, the ROM of the injured knee was lower in flexion-extension and internal-external rotation in comparison with the controlateral knee. One year after the surgery, four patients were classified normal (A) and one almost normal (B), according to the IKDC score, and changes in the kinematics of the five patients remained: lower flexion-extension ROM and higher internal-external rotation ROM in comparison with the controlateral knee. The 3D kinematics was changed after an ACL lesion and remained altered one year after the surger
    corecore