533 research outputs found

    Wet op Vervreemding van Grond 68 van 1981 : die haakplekke bestaan steeds

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    Litigasie rondom die formaliteitsvoorskrifte kragtens die bepalings van artikel 2(1) van die Wet op Vervreemding van Grond 68 van 1981 blyk epidemies te wees. Gedurende die afgelope vier jaar is daar nie minder nie as negentien sake hieroor gerapporteer. Hierdie artikel is daarop gemik om die haakplekke, soos byvoorbeeld die omskrywing van die koopsaak en koopprys, skrifstelling en skriftelike volmaggewing te identifiseer en konsepoplossings aan die hand te doen oor hoe die aangeleentheid moontlik aangespreek kan word. Hiermee saam word daar ook kursories gekyk na die invloed van die Wet op Verbruikersbeskerming 68 van 2008 en die nuwe Maatskappywet 71 van 2008 op die bestaande formaliteitsvoorskrifte. Die werkswyse wat gevolg word, is om die betrokke sake waarop die probleem betrekking het, te ontleed en vandaar die voorgestelde submissies in perspektief te plaas.http://www.lexisnexis.co.zaam2017Mercantile La

    Magnetic flux jumps in textured Bi2Sr2CaCu2O(8+d)

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    Magnetic flux jumps in textured Bi2Sr2CaCu2O(8+d) have been studied by means of magnetization measurements in the temperature range between 1.95 K and Tc, in an external magnetic field up to 9 T. Flux jumps were found in the temperature range 1.95 K - 6 K, with the external magnetic field parallel to the c axis of the investigated sample. The effect of sample history on magnetic flux jumping was studied and it was found to be well accounted for by the available theoretical models. The magnetic field sweep rate strongly influences the flux jumping and this effect was interpreted in terms of the influence of both flux creep and the thermal environment of the sample. Strong flux creep was found in the temperature and magnetic field range where flux jumps occur suggesting a relationship between the two. The heat exchange conditions between the sample and the experimental environment also influence the flux jumping behavior. Both these effects stabilize the sample against flux instabilities, and this stabilizing effect increases with decreasing magnetic field sweep rate. Demagnetizing effects are also shown to have a significant influence on flux jumping.Comment: 10 pages, 6 figures, RevTeX4, submitted to Phys. Rev.

    Species of Bursaphelenchus Fuchs, 1937 (Nematoda: Parasitaphelenchidae) and other nematode genera associated with insects from Pinus pinaster in Portugal

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    Insects associated with maritime pine, Pinus pinaster, in Portugal were collected and screened for the presence of Bursaphelenchus species. Nematodes were identified using Internal Transcribed Spacers-Restriction Fragment Length Polymorphism (ITS-RFLP) analysis of dauer juveniles and morphological identification of adults that developed from dauer juveniles on fungal cultures or on cultures in pine wood segments at 26 C. Several associations are described: Bursaphelenchus teratospicularis and Bursaphelenchus sexdentati are associated with Orthotomicus erosus; Bursaphelenchus tusciae, B. sexdentati and/or Bursaphelenchus pinophilus with Hylurgus ligniperda and Bursaphelenchus hellenicus with Tomicus piniperda, Ips sexdentatus and H. ligniperda. An unidentified Bursaphelenchus species is vectored by Hylobius sp. The previously reported association of Bursaphelenchus xylophilus with Monochamus galloprovincialis was confirmed. The association of Bursaphelenchus leoni with Pityogenes sp. is not definitively established and needs further studies for clarification. Other nematode genera besides Bursaphelenchus were found to be associated with the insects sampled, including two different species of Ektaphelenchus, Parasitorhabditis sp., Parasitaphelenchus sp., Contortylenchus sp. and other unidentified nematodes. The Ektaphelenchus species found in O. erosus is morphologically similar to B. teratospicularis found in the same insect; adults of both the species are found in cocoon-like structures under the elytra of the insects. Introduction Approximately one third of the nematodes belonging to the order Aphelenchida Siddiqi, 1980 are associated with insects (Poinar, 1983). These nematodes establish a variety of associations with the insects, which may be described as commensalism, e.g. phoresy (to the benefit of the nematode but not affecting the insect), mutualism (both the organisms benefit) or parasitism (nematodes benefit at the expense of the insect) (Giblin-Davis, 2004). Most Bursaphelenchus Fuchs, 1937 species are mycetophagous, feeding on fungi in the galleries of bark beetles and thu

    Large N_c, chiral approach to M_eta' at finite temperature

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    We study the temperature dependence of the eta and eta' meson masses within the framework of U(3)_L x U(3)_R chiral perturbation theory, up to next-to-leading order in a simultaneous expansion in momenta, quark masses and number of colours. We find that both masses decrease at low temperatures, but only very slightly. We analyze higher order corrections and argue that large N_c suggests a discontinuous drop of M_eta' at the critical temperature of deconfinement T_c, consistent with a first order transition to a phase with approximate U(1)_A symmetry.Comment: 21 pages, 6 figures. 2 footnotes added, 1 reference changed and 1 typo corrected. To be published in Phys. Rev.

    Designing Playful Games and Applications to Support Science Centers Learning Activities

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    In recent years there has been a renewed interest on science, technology, engineering, and mathematics (STEM) education. Following this interest, science centers\u27 staff started providing technology enhanced informal STEM education experiences. The use of well-designed mobile and ubiquitous forms of technology to enrich informal STEM education activities is an essential success factor. The goal of our research is to investigate how technology applications can be better used and developed for taking full advantage of the opportunities and challenges they provide for students learning about STEM concepts. In our approach, we have conducted a series of interviews with experts from science center curating and outdoor learning activities development, with the final goal of exploring and improving current learning environments and practices. This paper presents the development of set of design considerations for the development of STEM games and applications of young students. An initial set of best practices was first developed through semi-structures interviews with experts; and afterwards, by employing content analysis, a revised set of considerations was obtained. These results are useful for STEM education teachers, curriculum designers, curators and developers for K-12 education environments

    Some aspects of the Liouville equation in mathematical physics and statistical mechanics

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    This paper presents some mathematical aspects of Classical Liouville theorem and we have noted some mathematical theorems about its initial value problem. Furthermore, we have implied on the formal frame work of Stochastic Liouville equation (SLE)

    QCD sum rule for nucleon in nuclear matter

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    We consider the two-point function of nucleon current in nuclear matter and write a QCD sum rule to analyse the residue of the nucleon pole as a function of nuclear density. The nucleon self-energy needed for the sum rule is taken as input from calculations using phenomenological NN potential. Our result shows a decrease in the residue with increasing nuclear density, as is known to be the case with similar quantities

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
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