195 research outputs found

    Bibliographie des lagunes et du littoral de Côte d'Ivoire (Afrique de l'Ouest)

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    The present bibliography collects references on lagoon and coastal environments in Côte d'Ivoire. It is mainly based on: - the draft bibliography prepared by Charles-Dominique and Durand in 1979, edited in the Archives Scientifiques du Centre de Recherches Océanographiques d'Abidjan (vol. 5 no. 2); - the synthesis on the marine environment, published in 1993 (LeLoeuff, Marchal and Amon-Kothias editors); - and the synthesis on the lagoon environment, published in 1994 (Durand, Dufour, Guiral and Zabi editors). In spite of a careful check of the available documents, it is more than possible that references are lacking or erroneous. That's why this bibliography is still a draft, and the author will be glad to receive complements and/or corrections from lectors. After these contributions, a more comprehensive version will be proposed. Remarks can be sent to this e-mail: [email protected] or to the postal address

    Incidences de la modification de la circulation des eaux sur l'hydrochimie et le degré de contamination bacterienne d'un estuaire eutrophe tropical

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    In order to control the proliferation of floating aquatic vegetation in Côte d'Ivoire, a coastal inlet, allowing a direct communication between the Comoe river and the ocean, was created in September 1987. The impact of this operation on the hydrochemistry (salinity, nutrients, algal biomass) and the bacterial contamination level was studied in the area close to the Vridi canal

    Estimation des niveaux de pollution organique et bacterienne des eaux à proximité des berges de la ville d'Abidjan (Lagune Ebrié - Côte d'Ivoire)

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    This article presents the results of three surveys, which were undertaken in order to estimate the levels of organic and bacterial pollutions of the Ebrié lagoon banks in the urban area of Abidjan

    Moteurs et conséquences de la resuspension dans un lac sahélien peu profond : le lac de Guiers au Sénégal

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    La dynamique des particules dans les systèmes aquatiques est régit par l’interaction entre la resuspension et la sédimentation. Cette étude est consacrée à la détermination des processus responsables de la resuspension des particules dans le lac de Guiers situé au nord du Sénégal. Des échantillons ont été collectés au cours d’un cycle annuel au niveau de trois stations prises dans la partie centrale du lac. Dans ce site, la resuspension des particules est liée à l’action des vents mais aussi à la crue du fleuve Sénégal. La resuspension sous l’effet des vents se produit pendant l’harmattan, alors qu’en période d’alizés maritimes, c’est la crue du fleuve Sénégal qui est responsable de la remise en suspension des particules. Le taux de particule en suspension est plus important en période d’harmattan qui est marquée par des vitesses du vent plus élevées (moyenne de 3,6 m.s-1 fluctuant entre 1 et 7 m.s-1), mais surtout par un fetch fort (24 km). Cette évolution saisonnière de la resuspension affecte la turbidité de l’eau, les taux de matière en suspension, la biomasse  phytoplanctonique, le coefficient d’atténuation lumineuse, le flux des particules et la structure de la colonne d’eau. La resuspension sous l’effet des vagues créées par le vent associé au fetch élevé constitue dans ce système peu profond le principal processus contrôlant la dynamique des particules.Mots clés : Vagues, crue du fleuve, resuspension, particule, turbidité, lac de Guiers

    The Relationship Between Shoulder Arm Muscle Power and the Ability to Punch the Court Tennis Drive in Students of the 2022 FKIP USK Physical Education Study Program

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    Field observations obtained when I was on the committee of the Field Tennis League (LITEL) from these players stated that to achieve high tennis achievements, supported by good physical, technical, tactical and mental conditions, especially when hitting drives on sportsmen is a requirement that cannot be neglected, especially the game of court tennis. This type of research can be classified under Descriptive research as stated by Arikunto (1991: 63) that "Descriptive research. The number of samples in this study was 31 Penjaskesrek students. Data collection techniques in this study were Measurement of Power Ability of shoulder arm muscles and Measurement of Agility of Stroke Drive Tennis Court. The calculation of the correlation coefficient value above can be concluded that arm muscle power with the ability to punch the court tennis drive in FKIP USK Physical Education Students has a significant relationship. The results of the data calculation, showed that the correlation coefficient value (r) between the power of the shoulder arm muscles and the ability to punch the court tennis drive in FKIP USK Penjaskesrek Students was 0.50. In the sport of field tennis, the Drive punch is one of the basic techniques that must be mastered in the game of court tennis

    Nonmonotonous Magnetic Field Dependence and Scaling of the Thermal Conductivity for Superconductors with Nodes of the Order Parameter

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    We show that there is a new mechanism for nonmonotonous behavior of magnetic field dependence of the electronic thermal conductivity of clean superconductors with nodes of the order parameter on the Fermi surface. In particular, for unitary scatterers the nonmonotony of relaxation time takes place. Contribution from the intervortex space turns out to be essential for this effect even at low temperatures. Our results are in a qualitative agreement with recent experimental data for superconducting UPt_3. For E_{2u}-type of pairing we find approximately the scaling of the thermal conductivity in clean limit with a single parameter x=T/T_c\sqrt{B_{c2}/B} at low fields and low temperatures, as well as weak low-temperature dependence of the anisotropy ratio K_{zz}/K_{yy} in zero field. For E_{1g}-type of pairing deviations from the scaling are more noticeable and the anisotropy ratio is essentially temperature dependent.Comment: 37 pages, 8 Postscript figures, REVTE

    Heat Transport and the Nature of the Order Parameter in Superconducting UPt3UPt_3

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    Recent thermal conductivity data on the heavy fermion superconductor UPt3UPt_3 have been interpreted as offering support for an E2uE_{2u} model of the order parameter as opposed to an E1gE_{1g} model. In this paper, we analyze this issue from a theoretical standpoint including the detailed effects of Fermi surface and gap anisotropy. Our conclusion is that although current data put strong constraints on the gap anisotropy, they cannot definitively distinguish between these two models. Measurements on samples of varying quality could be decisive in this regard, however.Comment: 8 pages, revtex, 15 uunencoded postscript figure

    Wicked social–ecological problems forcing unprecedented change on the latitudinal margins of coral reefs: the case of southwest Madagascar

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    High-latitude coral reefs may be a refuge and area of reef expansion under climate change. As these locations are expected to become dryer and as livestock and agricultural yields decline, coastal populations may become increasingly dependent on marine resources. To evaluate this social–ecological conundrum, we examined the Grand Récif of Toliara (GRT), southwest Madagascar, which was intensively studied in the 1960s and has been highly degraded since the 1980s. We analyzed the social and ecological published and unpublished literature on this region and provide new data to assess the magnitude of the changes and evaluate the causes of reef degradation. Top-down controls were identified as the major drivers: human population growth and migrations, overfishing, and climate change, specifically decreased rainfall and rising temperature. Water quality has not changed since originally studied, and bottom-up control was ruled out. The identified network of social–ecological processes acting at different scales implies that decision makers will face complex problems that are linked to broader social, economic, and policy issues. This characterizes wicked problems, which are often dealt with by partial solutions that are exploratory and include inputs from various stakeholders along with information sharing, knowledge synthesis, and trust building. A hybrid approach based on classical fishery management options and preferences, along with monitoring, feedback and forums for searching solutions, could move the process of adaptation forward once an adaptive and appropriately scaled governance system is functioning. This approach has broad implications for resources management given the emerging climate change and multiple social and environmental stresses

    Theory of Thermal Conductivity in YBa_2Cu_3O_{7-\delta}

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    We calculate the electronic thermal conductivity in a d-wave superconductor, including both the effect of impurity scattering and inelastic scattering by antiferromagnetic spin fluctuations. We analyze existing experiments, particularly with regard to the question of the relative importance of electronic and phononic contributions to the heat current, and to the influence of disorder on low-temperature properties. We find that phonons dominate heat transport near T_c, but that electrons are responsible for most of the peak observed in clean samples, in agreement with a recent analysis of Krishana et al. In agreement with recent data on YBa_2(Cu_1-xZn_x)_3O_7-\delta the peak position is found to vary nonmonotonically with disorder.Comment: 4 pages, 4 figures, to be published in Phys. Rev. Let
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