3,543 research outputs found

    The poor and the white paper on land reform

    Get PDF
    The White Paper on Land Reform is based on commendable principles. Its three main policy objectives are: * Utilization ofland as a national asset* Broadening of access to land rights to the whole population* Upgrading of quality and security of title. Implementation of these policy prin­ciples should improve general living standards. The White Paper does not, however, stand up to scrutiny with re­gard to its impact on the urban poor.&nbsp

    Effect of time and thermo-mechanical couplings on polymers

    Get PDF
    National audienceAnalysis of the thermo-mechanical behaviour of polymers has been and still is the subject of many rheological studies both experimentally and theoretically. For small deformations, the modelling framework retained by rheologists is often of linear visco-elasticity, which led to the definition of complex modules and used to identify the glass transition temperature as the so called rule of time-temperature superposition. In this context, the effects of time are almost unanimously associated with viscous effects. It has also been observed that the dissipative effects associated with viscous effects are often very small compared to the coupling of sources indicating a high sensitivity of polymeric materials to temperature variations. This work is mainly focused on establishing the exact role of coupling effects, which also induce the effect of time. Using traditional experimental methods of visco-analysis (DMTA) and via an energy analysis of the behaviour, the goal of the thesis is to try to restate the time-temperature equivalence rule under the Thermodynamics of Irreversible Processes, taking into account the dissipative effects and coupling induced process deformation

    Addendum to 'The equivariant spectral function of an invariant elliptic operator'

    Full text link
    Let MM be a compact boundaryless Riemannian manifold, carrying an effective and isometric action of a torus TT, and P0P_0 an invariant elliptic classical pseudodifferential operator on MM. In this note, we strengthen asymptotics for the equivariant (or reduced) spectral function of P0P_0 derived previously, which are already sharp in the eigenvalue aspect, to become almost sharp in the isotypic aspect. In particular, this leads to hybrid equivariant LpL^p-bounds for eigenfunctions that are almost sharp in the eigenvalue and isotypic aspect.Comment: 14 pages. arXiv admin note: text overlap with arXiv:1512.0219

    EOR modeling study applied to Ainsa

    Get PDF

    Direct CP violation in β decays including ρ-ω mixing and covariant light-front dynamics.

    Get PDF
    Since its discovery in kaon decay in 1964, the origin of CP (Charge-Parity) violation has still not been completely understood. Even though the Standard Model is able to describe this phenomenon, its description involves many theoretical uncertainties. Examples are the parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements, and the hadronic matrix elements connected to the short and long distance effects. The interest in CP violation has increased with the rise of studies in cosmological physics (baryo-genesis) and also with the use of new models so-called "beyond the Standard Model", such as the Higgs model and its derivative, the left-right symmetric models and supersymmetric models.Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 200

    Training Strategies to Improve Muscle Power: Is Olympic-style Weightlifting Relevant?

    Get PDF
    Introduction: This efficacy study investigated the effects of (1) Olympic-style weightlifting (OWL), (2) motorized strength and power training (MSPT), and (3) free weight strength and power training (FSPT) on muscle power. Methods: Thirty-nine young athletes (20±3 yr.; ice hockey, volleyball and badminton) were randomized into the three training groups. All groups participated in 2-3 sessions/week for 8 weeks. The MSPT and FSPT groups trained using squats (two legs and single leg) with high force and high power, while the OWL group trained using clean and snatch exercises. MSPT was conducted as slow-speed isokinetic strength training and isotonic power training with augmented eccentric load, controlled by a computerized robotic engine system. FSPT used free weights. The training volume (sum of repetitions x kg) was similar between all three groups. Vertical jumping capabilities were assessed by countermovement jump (CMJ), squat jump (SJ), drop jump (DJ), and loaded CMJs (10-80 kg). Sprinting capacity was assessed in a 30 m sprint. Secondary variables were squat 1-repetitionmaximum, body composition and quadriceps thickness and architecture. Results: OWL resulted in trivial improvements, and inferior gains compared to FSPT and MSPT for CMJ, SJ, and DJ. MSPT demonstrated small, but robust effects on SJ, DJ and loaded CMJs (3-12%). MSPT was superior to FSPT in improving 30 m sprint performance. FSPT and MSPT, but not OWL, demonstrated increased thickness in the vastus lateralis and rectus femoris (4-7%). Conclusion: MSPT was time-efficient and equally or more effective than FSPT training in improving vertical jumping and sprinting performance. OWL was generally ineffective and inferior to the two other interventions.Training Strategies to Improve Muscle Power: Is Olympic-style Weightlifting Relevant?acceptedVersio

    Oblique reflections in the Mars Express MARSIS data set:stable density structures in the Martian ionosphere

    Get PDF
    The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) onboard the European Space Agency's Mars Express (MEX) spacecraft routinely detects evidence of localized plasma density structures in the Martian dayside ionosphere. Such structures, likely taking the form of spatially extended elevations in the plasma density at a given altitude, give rise to oblique reflections in the Active Ionospheric Sounder data. These structures are likely related to the highly varied Martian crustal magnetic field. In this study we use the polar orbit of MEX to investigate the repeatability of the ionospheric structures producing these anomalous reflections, examining data taken in sequences of multiple orbits which pass over the same regions of the Martian surface under similar solar illuminations, within intervals lasting tens of days. Presenting three such examples, or case studies, we show for the first time that these oblique reflections are often incredibly stable, indicating that the underlying ionospheric structures are reliably reformed in the same locations and with qualitatively similar parameters. The visibility, or lack thereof, of a given oblique reflection on a single orbit can generally be attributed to variations in the crustal field within the ionosphere along the spacecraft trajectory. We show that, within these examples, oblique reflections are generally detected whenever the spacecraft passes over regions of intense near-radial crustal magnetic fields (i.e., with a “cusp-like” configuration). The apparent stability of these structures is an important feature that must be accounted for in models of their origin
    corecore