11 research outputs found

    An investigation into the application and maintenance of Hamilton Russell traction on three orthopaedic wards

    No full text
    Investigates the application and maintenance of Hamilton Russell traction on three orthopedic wards. Use of the Hamilton Russell traction in the treatment of fractures of the femur; Level of knowledge in nurses working in an orthopedic area; Establishment of the theoretical traction using mathematics

    Transition from n- to p-type conduction concomitant with enhancement of figure-of-merit in Pb doped bismuth telluride: Material to device development

    No full text
    The majority of industrial, automobile processes, electrical appliances emit waste heat in the low-temperature range (<573 K), hence efficient thermoelectric materials operating in this range are highly needed. Bismuth telluride (Bi2Te3) based alloys are conventional thermoelectric material for the low-temperature application. The pure Bi2Te3 sample synthesized in this work exhibits n-type conduction. We demonstrate that by small doping of Pb at Bi site a transition in electrical transport form n- to p-type is observed. The figure-of-merit (ZT) of n-type Bi2Te3 is similar to 0.47 and optimized Bi1.95Pb0.05Te3 exhibit p-type conduction with enhanced ZT of similar to 0.63 at 386 K. The conversion efficiency of Bi1.95Pb0.05Te3 based single thermoelement with hot pressed Ni/Ag electrical contacts was found to be similar to 4.9% for a temperature difference (Delta T) of 200 K. The efficiency was further enhanced to similar to 12% (at Delta T similar to 494 K) in the segmented thermoelement consisting of Bi1.95Pb0.05Te3 and (AgSbTe2)(0.15)(GeTe)(0.85) (i.e. TAGS-85

    Transition from n- to p-type conduction concomitant with enhancement of figure-of-merit in Pb doped bismuth telluride: Material to device development

    No full text
    The majority of industrial, automobile processes, electrical appliances emit waste heat in the low-temperature range (<573 K), hence efficient thermoelectric materials operating in this range are highly needed. Bismuth telluride (Bi2Te3) based alloys are conventional thermoelectric material for the low-temperature application. The pure Bi2Te3 sample synthesized in this work exhibits n-type conduction. We demonstrate that by small doping of Pb at Bi site a transition in electrical transport form n- to p-type is observed. The figure-of-merit (ZT) of n-type Bi2Te3 is similar to 0.47 and optimized Bi1.95Pb0.05Te3 exhibit p-type conduction with enhanced ZT of similar to 0.63 at 386 K. The conversion efficiency of Bi1.95Pb0.05Te3 based single thermoelement with hot pressed Ni/Ag electrical contacts was found to be similar to 4.9% for a temperature difference (Delta T) of 200 K. The efficiency was further enhanced to similar to 12% (at Delta T similar to 494 K) in the segmented thermoelement consisting of Bi1.95Pb0.05Te3 and (AgSbTe2)(0.15)(GeTe)(0.85) (i.e. TAGS-85)

    Transition from n- to p-type conduction concomitant with enhancement of figure-of-merit in Pb doped bismuth telluride: Material to device development

    No full text
    The majority of industrial, automobile processes, electrical appliances emit waste heat in the low-temperature range (<573 K), hence efficient thermoelectric materials operating in this range are highly needed. Bismuth telluride (Bi2Te3) based alloys are conventional thermoelectric material for the low-temperature application. The pure Bi2Te3 sample synthesized in this work exhibits n-type conduction. We demonstrate that by small doping of Pb at Bi site a transition in electrical transport form n- to p-type is observed. The figure-of-merit (ZT) of n-type Bi2Te3 is similar to 0.47 and optimized Bi1.95Pb0.05Te3 exhibit p-type conduction with enhanced ZT of similar to 0.63 at 386 K. The conversion efficiency of Bi1.95Pb0.05Te3 based single thermoelement with hot pressed Ni/Ag electrical contacts was found to be similar to 4.9% for a temperature difference (Delta T) of 200 K. The efficiency was further enhanced to similar to 12% (at Delta T similar to 494 K) in the segmented thermoelement consisting of Bi1.95Pb0.05Te3 and (AgSbTe2)(0.15)(GeTe)(0.85) (i.e. TAGS-85)

    Tellurium-free thermoelectrics: Improved thermoelectric performance of n-type Bi2Se3 having multiscale hierarchical architecture

    No full text
    We report an improved thermoelectric performance of n-type Bi2Se3 bulk alloys synthesized by vacuum melt method followed by vacuum hot-pressing. In the samples so prepared, the synergetic combination of ultra low thermal conductivity (similar to 0.7 W/m K), high Seebeck coefficient (similar to-168 mu V/K), and low electrical resistivity (similar to 15 mu Omega-m) has been observed to successfully lead to a high figure-of-merit (ZT) of similar to 0.96 at 370 K. A detailed characterization of the samples reveals a presence of multiscale hierarchical defect structures i.e. atomic scale disorder arising from a multitude of factors such as large anharmonicity of Bi-Se bond due to electrostatic repulsion between the lone pair of Bi and charge of Se, nanoscale grains and dislocations trapped between mesoscale grains/grain boundaries accompanied by intrinsic layered structure of Bi2Se3. This compact layered grain structure in its consequence offers a high charge carrier mobility and thereby results into a high power factor, while multiscale hierarchical architecture accounts for the scattering of a wider spectrum of phonons leading to an ultra low thermal conductivity. In view of this promising thermoelectric performance together with the presence of copiously available constituent namely Se, the hot-pressed Bi2Se3 presents a technologically suitable and commercially viable alternative to the conventional Bi2Te3 which is based on expensive and scarcely available Te

    Alles Kidzzz: RCT naar een preventieve geïndiceerde individuele interventie voor agressie op de basisschool

    No full text
    Item does not contain fulltextFor elementary schoolchildren with aggressive behaviour, there is a need for effective preventive interventions to interrupt the development towards more serious behaviour problems. This rct study evaluated the effects of an indicated preventive individualized school-based intervention (Stay Cool Kids) to reduce aggression in selected children by enhancing cognitive behavioural skills. Schools (n = 48), with 264 fourth-grade children indicated by their teachers because of elevated externalizing behaviour, were randomly assigned to the intervention or control condition. The intervention reduced reactive and proactive aggression as reported by children, mothers, fathers or teachers (effect sizes: .11-.32). Clinically relevant changes in teacher-rated externalizing behaviour were found: The intervention reduced behaviour problems to (sub)clinical/normative levels. Children reported more positive self-perception and one aspect of social cognitive functioning changed. Ethnicity and gender moderated intervention effects on child and teacher reported aggression. Results demonstrate intervention effectiveness on outcome behaviour and child cognitions across informants under real-world conditions.17 p
    corecore