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This paper focuses on a comparative analysis of the most important parameters of an icebreaker ship’s sustainable operations: the operational availability, power performance and power performance deficiency of the multi-state Multi-Power Source Traction Drives of Norilsk-type Arctic icebreaker ships. These parameters have a significant impact on the correct choice of the propulsive system of icebreaking vessels. The parameters’ evaluation was based on statistical operational data on Arctic icebreaker ships with diesel-geared traction drive. The -transform approach was used to arrive at a solution of that problem. This approach drastically simplifies the solution compared with the straightforward Markov method.

The level of awareness about ocean wave energy as a viable source of useful energy has been increasing recently. Different concepts and methods have been suggested by many researchers to harvest ocean wave energy. This paper reviews and compares the efficiencies and power performance of different wave energy converters. The types of analyses used in deriving the reported efficiencies are identified, and the stage of the power conversion processes at which the efficiencies were determined is also identified. In order to find a common way to compare the efficiencies of different technologies, the hydrodynamic efficiency in relation to the characteristic width of the wave energy converters and the wave resource potential are chosen in this paper. The results show that the oscillating body systems have the highest ratio in terms of the efficiency per characteristic width, and overtopping devices have the lowest. In addition, with better understanding of the devices’ dynamics, the efficiencies of the newer oscillating water column and body systems would increase as the potential wave energy level increases, which shows that those newer designs could be suitable for more potential locations with large variations in wave energy potentials. At last, discussion about the cost of ocean wave energy is presented as well.

This article is about self-defense movements in Burkina Faso, with an emphasis on the interplay of political pragmatics and cultural representation in public debate. It examines how two different self-defense movements—the dozos and the koglweogos—articulate tradition and politics with respect to locally organized self-defense in present-day Burkina Faso. In addition to a description of these movements, this comparative study of self-defense movements adds the important dimension of political rivalry and antagonism between the movements under study. First, it demonstrates how the state has tried to contain self-defense movements. Second, the emergence of koglweogos is analyzed with respect to public debate, as well as the state’s attempts to contain the movement bureaucratically. Third, it describes how dozos and koglweogos seek to assert public authority in “the new Burkina Faso” that has taken shape since the fall of Blaise Compaoré in October, 2014. More specifically, this article is devoted to the conflictual relationship between the dozos and the koglweogos that was publicly enacted in late 2016 and early 2017. Self-defense movements must not only be locally and traditionally legitimate, but they also need to be responsible actors in the national political space. Hence, “performing tradition, while doing politics” simultaneously represents the political containment and the cultural legitimacy of the self-defense movements. Cet article porte sur les mouvements d’autodéfense au Burkina Faso, en mettant l’accent sur l’interaction de la pragmatique politique et de la représentation culturelle dans le débat public. Il examine comment deux mouvements d’autodéfense différents — les dozos et les koglweogos — articulent la tradition et la politique en ce qui concerne l’autodéfense organisée localement au Burkina actuel. Outre une description de ces mouvements, cette étude comparative des mouvements d’autodéfense ajoute la dimension importante de la rivalité politique et de l’antagonisme entre les mouvements. Tout d’abord, il montre comment l’État a tenté de contenir ces mouvements d’autodéfense. En second lieu, l’émergence de koglweogos est analysée en ce qui concerne le débat public, ainsi que les tentatives de l’État pour contenir le mouvement sur le plan bureaucratique. En troisième lieu, il décrit comment les dozos et koglweogos cherchent à affirmer une autorité publique dans le cadre de « la nouvelle Burkina Faso » qui a pris forme depuis la chute de Blaise Compaoré en octobre 2014. Plus précisément, cet article est consacré à la relation conflictuelle entre les dozos et les koglweogos qui a été publiquement promulguée en fin 2016 et au début 2017. Les mouvements de l’autodéfense doivent non seulement être localement et traditionnellement légitimes, mais ils doivent aussi être des acteurs responsables dans l’espace politique national. Par conséquent, « pratiquer la tradition, tout en faisant la politique » représente à la fois l’endiguement politique et la légitimité culturelle des mouvements d’autodéfense.

Secrecy and its performative display have been privileged perspectives in the study of poro and similar power associations in West Africa. I develop an alternative understanding of the Senufo poro as an institution that fosters and sustains bodily experience, establishing an all-embracing sensory regime for members as well as non-members in their villages. Participation in nighttime funerary rites creates the image of an invisible social body, and shared bodily experience informs collective intentionality towards the social. Serving as a stable nodal point in everyday discourse, this function contributes to the recent revitalization of poro associations in Côte d’Ivoire’s post-conflict society. Le secret et sa démonstration performative ont été des perspectives privilégiées dans l’étude du poro et des associations semblables de pouvoir en Afrique de l’Ouest. Dans cet article, Je développe une compréhension autre du Sénoufo poro comme une institution qui favorise et soutien l’expérience corporelle, en établissant un régime sensoriel universel pour les membres et non membres des villages. La participation aux rites funéraires nocturnes crée l’image d’un corps social invisible et l’expérience corporelle partagée informe l’intentionnalité collective et sociale. Servant de point central stable dans le discours quotidien, cette fonction contribue à la revitalisation récente des associations poro dans la société après le conflit de la Côte d’Ivoire.

This article looks at the characteristic shirts of the donso, or initiated Mande hunters. Often described in the literature as visual displays of the wearer’s power, in the context of contemporary Burkina Faso these shirts are instead an example of how hunters deal with representations of power through an aesthetics of concealment (Ferme 2001). An excess of display is conversely connected with the politics of state-recognized hunters’ associations. Issues of ecological change, local conceptions of power, and contemporary struggles with state authority intersect in the practices and discourses on hunters’ shirts. Cet article se penche sur les chemises caractéristiques des donso ou chasseurs initiés du Mandé. Souvent décrites dans la littérature comme des visualisations de la puissance du porteur, dans le contexte contemporain burkinabé ces chemises sont plutôt un exemple de la façon dont les chasseurs traitent les représentations du pouvoir par une esthétique de la dissimulation (Ferme 2001). Un excès d’affichage est inversement lié à la politique des associations de chasseurs reconnues par l’État. Les enjeux de changements écologiques, les conceptions locales du pouvoir et les luttes contemporaines avec l’autorité de l’État se recoupent dans les pratiques et les discours sur les chemises des chasseurs.

This article analyzes the relationship between Mande hunters (dozos) and the Ivorian state in the prefecture of Ouangolodougou in northern Côte d’Ivoire. Having adopted a prominent security role during the violent conflict of 2002–2011, dozos have made continuing efforts to maintain their position in the post-conflict state. To negotiate their position, they draw on a performative repertoire, such as the display of powerful attributes in the context of processions. Although they have had to concede some more strategic and profitable activities to the reestablished state, dozo chiefs effectively govern the rural northern borderlands of Côte d’Ivoire. Cet article analyse la relation entre les chasseurs Mandé appelés “dozos” et l’Etat Ivoirien dans la préfecture de Ouangolodougou au nord de la Côte d’Ivoire. Ayant adopté un rôle sécuritaire important pendant le violent conflit armé de 2002 à 2011, les dozos ont fourni des efforts à maintenir leur position dans l’Etat après conflit. Afin de négocier leur position, ils s’appuient sur un répertoire performatif tel que l’étalage des attributs puissants dans le contexte des processions. Bien qu’ils aient dû concéder des activités plus stratégiques et plus rentables à l’Etat rétabli, les chefs dozos gouvernent effectivement les régions frontalières rurales situées au nord de la Côte d’Ivoire. Este artigo analisa a relação entre os caçadores Mandé (dozos) e o Estado da Costa do Marfim na prefeitura de Ouangolodougou, no norte do país. Tendo desempenhado um papel securitário importante nos violentos conflitos entre 2002 e 2011, os dozos empenharam-se em manter, até hoje, a sua posição no Estado pós-conflito. Com o objetivo de negociarem a sua posição, os dozos recorrem a um repertório performativo, nomeadamente à exibição dos seus atributos no contexto das procissões. Apesar de terem sido forçados a conceder algumas atividades mais estratégicas e rentáveis ao Estado restabelecido, na prática são os chefes dozo quem governa efetivamente as fronteiras rurais do norte da Costa do Marfim.

The West African savannah is an area where old and new institutions fill the lacunae that limited statehood has left. Some of them claim a long history, others have emerged recently as a reaction to military and civil crises. The performance of power, its display and presentation, is a theme that all these associations share. They do so on different occasions and by different means, which highlights their diverging ethics and attitudes towards their local communities and the state. This introduction to the guest edited forum outlines central themes of these performances and discusses performativity in West African power associations. La savane ouest-africaine est une région dans laquelle des institutions tant anciennes que nouvelles viennent combler les lacunes laissées par les États à souveraineté limitée. Certaines d’entre elles sont caractérisées par une longue histoire, alors que d’autres ont vu le jour récemment en réaction aux crises militaires et civiles. La performance du pouvoir – sa présentation et sa représentation – est un thème commun à toutes ces institutions. Celles-ci s’engagent dans ces performances à diverses occasions et par des moyens multiples, mettant en lumière une éthique et des attitudes divergentes envers les communautés locales et l’État. L’introduction de ce forum dessine les contours des thèmes centraux de ces performances et discute la performativité de ces institutions en Afrique occidentale. A savana da África ocidental é um território onde novas e antigas instituições preenchem as lacunas criadas pelo baixo nível de estatização. Algumas dessas instituições têm uma longa história, outras emergiram recentemente, em resultado de crises militares e civis. Todas estas associações partilham entre si o tema da performance do poder, da sua exibição e apresentação. Fazem-no em diferentes ocasiões e de formas diversas, o que evidencia a prevalência de éticas e atitudes divergentes em relação às respetivas comunidades locais e ao estado. Nesta introdução ao fórum editado por um convidado, elencamos os temas centrais destas performances e analisamos a natureza performativa das associações que exercem poder na África ocidental.

The aim of this study is to investigate the effects of the separator thickness on not only the heat and mass transfer characteristics, but also the power generation characteristics of a polymer electrolyte membrane fuel cell (PEMFC) with a thin polymer electrolyte membrane (PEM) and thin gas diffusion layer (GDL) operated at higher temperatures of 363 and 373 K. The in-plane temperature distributions on the back of the separator at the anode and cathode, which are the opposite sides to the GDL, are measured using a thermograph at various initial cell temperatures (Tinit), relative humidity (RH) levels, and supply gas flow rates. The total voltage corresponding to the load current is measured in order to evaluate the performance of the PEMFC. As a result, it is revealed that the effect of the RH on the power generation characteristics is more significant when the separator thickness decreases. It is revealed that the power generation performance obtained at high current densities decreases with the increase in Tinit with thinner separator thicknesses. According to the investigation of the in-plane temperature distribution, it is clarified that the temperature decreases at corner positions in the separator with the separator thickness of 2.0 mm, while the temperature gradually increases along with the gas flow with separator thicknesses of 1.5 mm and 1.0 mm.

The hunting songs of the majority-Muslim, Odienné region of Northwestern Côte d’Ivoire accomplish more than meets the ear. They conjoin and distinguish Muslim goals and ostensibly non-Muslim hunting practices. The musical repertoire of my host, Dramane Coulibaly, is illustrative. This study examines the role that Dramane’s songs played in motivating initiated dozo hunters to kill game during dozo funerals, a primary concern for dozos at these events. Next, it analyzes the structure and content of Dramane’s songs in relation to the embodied, emplaced, and material dimensions of dozo funerals, where Dramane’s performances served to calm the spirits of the dead so that they would leave the living in peace. Finally, it examines the musical aspects of Dramane’s songs in relation to Islam, with the aim of broadening the study of Islam in West Africa and beyond to encompass the texts and performance practices of dozo funerals. les chants de chasse de la région à majorité musulmane d’Odienné, au nord-ouest de la Côte d’Ivoire, accomplissent plus qu’il n’y parait. Ils joignent et distinguent les objectifs musulmans et les pratiques de chasse apparemment non-musulmanes. Les chansons de mon hôte, Dramane Coulibaly, sont représentatives. Cette étude examine tout d’abord la relation substantielle que les textes de chansons de Dramane établissent entre ses performances et la chasse, une préoccupation centrale des dozos. Ensuite, il analyse la structure et le contenu des chansons de Dramane en relation avec les dimensions symboliques réalisées de mises en scène des funérailles dozo, où ses performances ont servi à calmer les esprits des morts afin qu’ils puissent laisser en paix les vivants. Enfin, il examine les aspects musicaux des chansons de Dramane en relation avec l’islam, dans le but d’élargir l’étude de l’islam en Afrique de l’Ouest et de l’islam en général, pour y inclure l’esthétique sonique et cinétique des performances dozo. As canções de caça típicas de Odienné, uma região no noroeste da Costa do Marfim de maioria muçulmana, cumprem mais funções do que o ouvido alcança. Elas articulam e distinguem os objetivos muçulmanos e as práticas de caça aparentemente não muçulmanas. As canções de Dramane Coulibaly, o meu anfitrião, são disso exemplificativas. O presente artigo analisa a relação de causa e efeito que as letras das canções de Dramane estabelecem entre as suas performances e a caça, uma preocupação central para os dozos. Em seguida, analisa-se a estrutura e o conteúdo das canções de Dramane e a sua relação com as dimensões materiais e de concretização dos funerais dozo, onde as suas performances serviam para acalmar os espíritos dos mortos, de modo que estes deixassem os vivos em paz. Por fim, o artigo debruça-se sobre os aspetos musicais que, nas canções de Dramane, se relacionam com o Islão, tendo como objetivo um aprofundamento do estudo do Islão na África ocidental – e do Islão em geral – que inclua a estética sonora e cinética das performances dozo.

IEA Wind Task 32 exists to identify and mitigate barriers to the adoption of lidar for wind energy applications. It leverages ongoing international research and development activities in academia and industry to investigate site assessment, power performance testing, controls and loads, and complex flows. Since its initiation in 2011, Task 32 has been responsible for several recommended practices and expert reports that have contributed to the adoption of ground-based, nacelle-based, and floating lidar by the wind industry. Future challenges include the development of lidar uncertainty models, best practices for data management, and developing community-based tools for data analysis, planning of lidar measurements and lidar configuration. This paper describes the barriers that Task 32 identified to the deployment of wind lidar in each of these application areas, and the steps that have been taken to confirm or mitigate the barriers. Task 32 will continue to be a meeting point for the international wind lidar community until at least 2020 and welcomes old and new participants.