8,128 research outputs found

    Colophospermum mopane Wood Utilisation in the Northeast of the Limpopo Province, South Africa

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    The use of Colophospermum mopane wood was quantified from six villages in the northeast of the Limpopo Province, South Africa. One hundred and eighty individuals were interviewed from the selected villages. Three villages were located in the depleted woodlands and the remaining three at abundant woodlands. Traditional governance structures within the selected villages and relevant conservation department officials were also interviewed. Colophospermum mopane is an essential source of fuelwood and provide poles used for construction of traditional structures. Each family uses 6.8 ± 0.1 kg of Colophospermum mopane fuelwood for cooking day-1 in the woodland depleted villages, while 8.2 ± 0.2 kg is used at the woodland abundant villages. Colophospermum mopane is preferred for construction of traditional structures because its wood is durable and is able to resists the effects of termites and wood borers

    Rosenfeld functional for non-additive hard spheres

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    The fundamental measure density functional theory for hard spheres is generalized to binary mixtures of arbitrary positive and moderate negative non-additivity between unlike components. In bulk the theory predicts fluid-fluid phase separation into phases with different chemical compositions. The location of the accompanying critical point agrees well with previous results from simulations over a broad range of non-additivities and both for symmetric and highly asymmetric size ratios. Results for partial pair correlation functions show good agreement with simulation data.Comment: 8 pages with 4 figure

    Direct observation of isolated Damon-Eshbach and backward volume spin-wave packets in ferromagnetic microstripes

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    The analysis of isolated spin-wave packets is crucial for the understanding of magnetic transport phenomena and is particularly interesting for applications in spintronic and magnonic devices, where isolated spin-wave packets implement an information processing scheme with negligible residual heat loss. We have captured microscale magnetization dynamics of single spin-wave packets in metallic ferromagnets in space and time. Using an optically driven high-current picosecond pulse source in combination with time-resolved scanning Kerr microscopy probed by femtosecond laser pulses, we demonstrate phase-sensitive real-space observation of spin-wave packets in confined permalloy (Ni80Fe20) microstripes. Impulsive excitation permits extraction of the dynamical parameters, i.e. phase- and group velocities, frequencies and wave vectors. In addition to well-established Damon-Eshbach modes our study reveals waves with counterpropagating group- and phase-velocities. Such unusual spin-wave motion is expected for backward volume modes where the phase fronts approach the excitation volume rather than emerging out of it due to the negative slope of the dispersion relation. These modes are difficult to excite and observe directly but feature analogies to negative refractive index materials, thus enabling model studies of wave propagation inside metamaterials

    COSY-11: an experimental facility for studying meson production in free and quasi-free nucleon-nucleon collisions

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    The COSY-11 experimental setup is an internal facility installed at the COoler SYnchrotron COSY in Juelich. It allows to investigate meson production in free and quasi-free nucleon-nucleon collisions, eg. pp --> pp meson and pd --> p_sp np meson reactions. Drift chambers and scintillators permit to measure outgoing protons, separated in magnetic field of COSY-11 dipole. Neutrons are registered in the neutron modular detector installed downstream the beam. Recently, the experimental setup has been extended with spectator detector, deuteron drift chamber and polarization monitoring system, and since then meson production can be investigated also as a function of spin and isospin of colliding nucleons.Comment: Presented at LEAP05: International conference on Low Energy Antiproton Physics, Bonn - Juelich, Germany, May 16-22, 200

    Isospin dependence of the eta' meson production in nucleon--nucleon collisions

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    According to the quark model, the masses of eta and eta' mesons should be almost equal. However, the empirical values of these masses differ by more than the factor of two. Similarly, though the almost the same quark-antiquark content, the total cross section for the creation of these mesons close to the kinematical thresholds in the pp --> ppX reaction differs significantly. Using the COSY-11 detection setup we intend to determine whether this difference will also be so significant in the case of the production of these mesons in the proton-neutron scattering. Additionally, the comparison of the pp --> pp eta' and pn --> pn eta' total cross sections will allow to learn about the production of the eta' meson in the channels of isospin I = 0 and I = 1 and to investigate aspects of the gluonium component of the eta' meson.Comment: Presented at LEAP05: International conference on Low Energy Antiproton Physics, Bonn - Juelich, Germany, May 16-22, 200

    Not Just Efficiency: Insolvency Law in the EU and Its Political Dimension

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    Certain insolvency law rules, like creditors’ priorities and set-off rights, have a distributive impact on creditors. Distributional rules reflect the hierarchies of values and interests in each jurisdiction and, as a result, have high political relevance and pose an obstacle to reforming the EU Insolvency Regulation. This paper will show the difficulty of reform by addressing two alternative options to regulate cross-border insolvencies in the European Union. The first one is the ‘choice model’, under which companies can select the insolvency law they prefer. Although such a model would allow distressed firms to select the most efficient insolvency law, it would also displace Member States’ power to protect local constituencies. The choice model therefore produces negative externalities and raises legitimacy concerns. The opposite solution is full harmonisation of insolvency law at EU level, including distributional rules. Full harmonisation would have the advantage of internalising all externalities produced by cross-border insolvencies. However, the EU legislative process, which is still based on negotiations between states, is not apt to decide on distributive insolvency rules; additionally, if harmonisation includes such rules, it will indirectly modify national social security strategies and equilibria. This debate shows that the choice regarding power allocation over bankruptcies in the EU depends on the progress of European integration and is mainly a matter of political legitimacy, not only of efficiency

    Causation, Measurement Relevance and No-conspiracy in EPR

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    In this paper I assess the adequacy of no-conspiracy conditions employed in the usual derivations of the Bell inequality in the context of EPR correlations. First, I look at the EPR correlations from a purely phenomenological point of view and claim that common cause explanations of these cannot be ruled out. I argue that an appropriate common cause explanation requires that no-conspiracy conditions are re-interpreted as mere common cause-measurement independence conditions. In the right circumstances then, violations of measurement independence need not entail any kind of conspiracy (nor backwards in time causation). To the contrary, if measurement operations in the EPR context are taken to be causally relevant in a specific way to the experiment outcomes, their explicit causal role provides the grounds for a common cause explanation of the corresponding correlations.Comment: 20 pages, 1 figur

    Характеристика экономических отношений на финансовом рынке Украины

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    Розглянуто проблеми, особливості функціонування та взаємодії учасників фінансового ринку України. Обґрунтовано наявність внутрішніх фінансових джерел формування ресурсного потенціалу вітчизняних банків, доведено їх пріоритетність для країни порівняно із зовнішніми джерелами. Окреслено причини, що зумовлюють дефіцит ресурсного потенціалу в банківській системі України. Ключові слова: заощадження, нагромадження, банки, економічне зростання, посередники, фінансовий ринок, ресурси, трансформація, інвестиційний потенціал.Рассмотрены проблемы, особенности функционирования и взаимодействия участников финансового рынка Украины. Обосновано наличие внутренних финансовых источников формирования ресурсного потенциала отечественных банков, доказана их приоритетность для страны по сравнению с внешними источниками. Очерчены причины, которые предопределяют дефицит ресурсного потенциала в банковской системе Украины. Ключевые слова: сбережения, накопления, банки, экономический рост, посредники, финансовый рынок, ресурсы, трансформация, инвестиционный потенциал.The present paper examines topical problems related to the specific aspects of economic relations in the financial market of Ukraine. The relevance and selection of the theme stem from the fact that financial market as a specific organization form of cash flows takes a leading place in the economic mechanism of market economy. Agents of this market are engaged in a whole range of complex economic relations which in their turn play a key role in securing a dynamic and sustainable economic growth of a country. Development of the financial market and creation of adequate flexible and adaptive economic relations between its players are critical for Ukraine. This is explained by specific aspects of the economic system formation and reforming, which are related to undergoing an intersystem transformation stage. The indicated circumstances predetermined the goal and objectives of the study pursued, which come to examination of economic relations in the financial market of Ukraine, identification of the interaction specificity of various financial intermediaries in the accumulation process of idle cash and its transformation into the investment capital of national economy. Based on the results of the analysis conducted, it is established that unlike countries with developed financial systems, where the majority of institutional participants of the capital market are proportionally developed, it is the banking sector that dominates in Ukraine and has a determinant role in financing the economic development of the state. The availability of domestic financial resources for forming the resource potential of banks is substantiated, and their priority versus external resources for Ukraine is proved. The comparison of gross savings and gross capital formation allowed identifying certain problems as to transformation of the former into investment resources in Ukraine. The paper outlines some causes of a poor resource potential of national banking institutions. Keywords: savings, accumulation, banks, economic growth, intermediaries, financial market, resources, transformation, investment potential

    A method to disentangle single- and multi-meson production in missing mass spectra from quasi-free pn --> pn X reactions

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    The separation of contributions from multi- and single-meson production in the missing mass spectrum of the quasi-free pn --> pnX reaction constitutes a~challenging task when the reaction is studied close to threshold. This is especially true if the resolution of the mass determination is comparable with the excess energy and if the investigated signal appears close to the kinematical limit. In this article we outline a method which permits the extraction of the signal originating from the creation of a single meson without the necessity of conducting model-dependent simulations. For the pd --> pnXp(spectator) reactions, the method allows one to combine events corresponding to multi-meson production at various excess energies with respect to the pn --> pn meson process, and hence leads to an increase of the statistics needed for the determination of the shape of the multi-meson background. As an example of the application of the method, we demonstrate that the evaluation of the data from the pd --> pnXp(sp) process according to the described technique enables one to extract a signal of the pn --> pn eta reaction whose shape is consistent with expectations, supporting the correctness and usefulness of the method introduced.Comment: 14 pages, 10 figure
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