Millogo Y.,Bobo-Dioulasso Polytechnic University |
Millogo Y.,CNRS Tribology and Dynamic Systems Laboratory |
Morel J.-C.,CNRS Tribology and Dynamic Systems Laboratory |
Aubert J.-E.,CNRS Materials and Construction Durability Laboratory |
Ghavami K.,Pontifical Catholic University of Rio de Janeiro
Construction and Building Materials | Year: 2014
There is an intense on-going search for less polluting materials and technologies, which consume little energy in their production, construction and/or utilization. Attention of the researchers has turned to materials, which found applications in engineering in pre-industrial times: local vegetable fibers and earth composites are one of the promising materials. This paper presents the results of an investigation in establishing the physical and mechanical properties of Hibiscus cannabinus fibers which have been used in the fabrication of Pressed Adobe Blocks (PABs). The PABs have been reinforced with 0.2-0.8 wt.% of 30 mm and 60 mm lengths of H. cannabinus fibers. The microstructural characteristics of the PABs composites were investigated using X-ray diffraction (XRD), thermal gravimetric analyses (TGA), scanning electronic microscopy (SEM) and video microscopy. It was established that the addition with 0.2-0.6 wt.% of 30 mm long fibers reduced the dimensions of the pores in the PABs with the improvement of their mechanical properties. However, the addition of 0.8 wt.% of 60 mm fibers had negative effects on the compressive strength. The elaborated Pressed Adobe Blocks specimens were suitable as building material with contribution for thermal comfort. © 2013 Elsevier B.V. All rights reserved.
Ouedraogo A.,Bobo-Dioulasso Polytechnic University
International Journal of Dynamical Systems and Differential Equations | Year: 2016
Our purpose is to explicit the assumptions of a technical and fundamental lemma which has been used in many works as a main tool to get the uniqueness of solutions for some nonlinear and degenerate parabolic problems. In our investigation, we hope to generalise this result in a class of Hölder convection-diffusion functions. We also complete and validate the previous works by proving that the class of functions satisfying these hypotheses is not empty. Copyright © 2016 Inderscience Enterprises Ltd.
Zabsonre J.D.D.,Bobo-Dioulasso Polytechnic University |
Lucas C.,French National Center for Scientific Research |
Ouedraogo A.,Bobo-Dioulasso Polytechnic University
Nonlinear Analysis: Real World Applications | Year: 2013
In this paper, we consider a viscous bilayer shallow water model in one space dimension that represents two superposed immiscible fluids. For this model, we prove the existence of strong solutions in a periodic domain. The initial heights are required to be bounded above and below away from zero and we get the same bounds for every time. Our analysis is based on the construction of approximate systems which satisfy the BD entropy and on the method developed by A. Mellet and A. Vasseur to obtain the existence of global strong solutions for the one dimensional Navier-Stokes equations. © 2012 Elsevier Ltd. All rights reserved.
Ouedraogo F.,Bobo-Dioulasso Polytechnic University |
Cherblanc F.,Montpellier University |
Naon B.,Bobo-Dioulasso Polytechnic University |
Benet J.-C.,Montpellier University
Journal of Hydrology | Year: 2013
The dynamics of water content in the superficial layers of soils is critical in the modelling of land-surface processes. In arid regions, vapour flux contributes significantly to the global water mass balance. To account for it in theoretical descriptions, most of the models proposed in the literature rely on the local equilibrium assumption that constrains the vapour pressure to remain at its equilibrium value. It implicitly amounts to consider an instantaneous phase change. Recent works underlined a retardation time and a decrease in phase change rate as the water content gets lower. Therefore, the objective is to revisit water transport modelling by rejecting the local equilibrium assumption. This requires developing a non-equilibrium model by taking into account the phase change kinetics. To assess the interest of this approach, a natural soil of Burkina-Faso has been experimentally characterized from independent tests and soil column experiments have been carried out. The comparison of experimental drying kinetics and water content profiles with computational predictions confirms the reliability of this description. Liquid/gas non-equilibrium is significant in a limited subsurface zone which defines explicitly the transition from liquid transport in lower layers to vapour transport in upper layers, i.e., the evaporation front. The overall moisture dynamics is governed by the coupling between water transport mechanisms (liquid filtration, vapour diffusion, phase change) that mainly occurs in this transition zone. © 2013 Elsevier B.V.
Millogo Y.,Bobo-Dioulasso Polytechnic University |
Millogo Y.,University of Lyon |
Millogo Y.,University of Ouagadougou |
Morel J.-C.,University of Lyon
Materials and Structures/Materiaux et Constructions | Year: 2012
Microstructures of adobes, manufactured with clayey soil containing an important amount of quartz and stabilised with cement up to 12% by weight, were investigated with X-ray diffraction, infrared spectrometry, differential thermal analysis, scanning electron microscopy and energy dispersive spectrometry. The water absorption and mechanical (compressive and flexure strengths) characteristics of specimens elaborated with these mixtures were also measured. Cement additions resulted in the formation of calcium silicate hydrate (CSH) type tobermorite, portlandite, ettringite, iron oxyhydroxide and calcite. The CSH was formed through the hydration of anhydrous cement compounds (alite and belite). The formation of CSH through pozzolanic reaction, requiring kaolinite (unique clay minerals) and tiny quartz (obtained with the same material mixed of quicklime) is negligible. Moreover, CSH marked crystallisation with curing time contributed to the improvement of mechanical properties. The cement stabilised adobes comprised of 4-12% by weight cement, immersed for 4 days, were still suitable as building materials according to the required standards. This study concludes that for cement stabilised adobes, clayey soils containing an important amount of quartz were suitable soils for manufacturing resistant and durable adobes. © 2012 RILEM.
Millogo V.,Swedish University of Agricultural Sciences |
Svennersten Sjaunja K.,Swedish University of Agricultural Sciences |
Ouedraogo G.A.,Bobo-Dioulasso Polytechnic University |
Agenas S.,Swedish University of Agricultural Sciences
Food Control | Year: 2010
The aim of this study was to investigate raw milk hygiene and composition along the dairy chain in Burkina Faso. Milk samples were taken during the rainy and dry seasons from individual cows, farm tanks, milk collectors' churns, dairy processing unit tanks and at local markets. The results showed lower total bacteria count (10-104 cfu/ml) in individual cow milk than later in the dairy chain. The total bacteria count in farm tank milk was 106 cfu/ml and 107 cfu/ml in tank milk at dairy processing units, in milk collectors' churns and in market buckets. Somatic cell count (100,000-150,000 cells/ml) did not show significant variation between individual cow milk and in the rest of the chain. Higher pH and lower milk fat and lactose contents were found in market bucket milk than in farm and processing unit tank milks. It was concluded that milk from the cow is of good hygienic quality, but milk is often contaminated after milking, and the hygienic quality is very low when it reaches the consumers. Also, milk sold at local markets had low fat and lactose contents and high pH during the rainy season, indicating that the milk may have been diluted, which may further increase the hazards for human health. © 2010 Elsevier Ltd. All rights reserved.
Tiendrebeogo T.,Bobo-Dioulasso Polytechnic University
Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST | Year: 2016
Cloud computing technologies have attracted considerable interest in recent years. Thus, these latters became inescapable in most part of the developments of applications. It constitutes a new mode of use and of offer of IT resources in general. Such resources can be used “on demand” by anybody who has access to the internet. Cloud architecture allows today to provide a number of services to the software and database developers among others remote. But for most of the existing systems, the quality of service in term of services’ indexation is not present. Efforts are to be noted as for the search for the performance on the subject. In this paper, we define a new cloud computing architecture based on a Distributed Hash Table (DHT) and design a prototype system. Next, we perform and evaluate our cloud computing indexing structure based on a hyperbolic tree using virtual coordinates taken in the hyperbolic plane. We show through our experimental results that we compare with others clouds systems to show our solution ensures consistence and scalability for Cloud platform. © ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2016.
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: ICT-39-2015 | Award Amount: 2.80M | Year: 2016
The WAZIUP project, namely the Open Innovation Platform for IoT-Big Data in Sub-Saharan Africa is a collaborative research project using cutting edge technology applying IoT and Big Data to improve the working conditions in the rural ecosystem of Sub-Saharan Africa. First, WAZIUP operates by involving farmers and breeders in order to define the platform specifications in focused validation cases. Second, while tackling challenges which are specific to the rural ecosystem, it also engages the flourishing ICT ecosystem in those countries by fostering new tools and good practices, entrepreneurship and start-ups. Aimed at boosting the ICT sector, WAZIUP proposes solutions aiming at long term sustainability. The consortium of WAZIUP involves 7 partners from 4 African countries and partners from 5 EU countries combining business developers, technology experts and local Africa companies operating in agriculture and ICT. The project involves also regional hubs with the aim to promote the results to the widest base in the region.
Agency: European Commission | Branch: FP7 | Program: CP-FP-SICA | Phase: ENV.2009.2.1.3.2 | Award Amount: 4.53M | Year: 2010
UNDESERT aims at combatting desertification and land degradation in order to mitigate their impacts on ecosystem services, and following on human livelihoods. The West African region is central for understanding desertification and degradation processes, which are already severe and widespread as a consequence of climate change and human impact. An improved understanding of the effects of desertification and degradation processes is obtained on a local to regional scale by integrating remote sensing information with sound field data on biodiversity and soil as well as socioeconomic and climate data. On this basis decision support models and tools will be developed and introduced to natural resource managers. UNDESERT also includes two very practical aspects, 1) restoration through tree plantations, which will be certified for CO2 marketing as the first restoration site in West Africa, 2) ecosystem management based on scientific data and best practices developed in close collaboration between scientists and local communities. As a demand driven project, UNDESERT activities will be implemented by employing 17 young PhD students, who will receive training to enhance future capacities to manage risks and uncertainties in the frame of future demographic and climatic changes. The scientific results will be used to combat desertification and degradation directly and will be transferred to international programs in order to contribute to the implementation of relevant international strategies, initiatives and commitments of the EU and African countries.
Bobo-Dioulasso Polytechnic University | Date: 2016-09-14
Clothing, namely, blazers, t-shirts, dress pants, dress shirts, and ties.