Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Search Results: 1 - 10 of 142 matches for " Ghislain Mengata Mengounou "
All listed articles are free for downloading (OA Articles)
Page 1 /142
Display every page Item
Elaboration and Performance Analysis of a Bio-Based Insulating Liquid from Castor Oil for Power Transformers  [PDF]
Emeric Tchamdjio Nkouetcha, Ghislain Mengata Mengounou, Adolphe Moukengue Imano
Open Access Library Journal (OALib Journal) , 2019, DOI: 10.4236/oalib.1105404
The research for new mineral oil substitutes focuses on vegetable oils known for their biodegradability and low toxicity. This paper focuses on the development and analysis of physicochemical and dielectric properties of a bio-based insulating liquid from castor oil. Castor oil is an inedible tropical resource. It has a good annual oil yield and is widely available in developing countries. Cold pressing of castor seeds is the most appropriate non-chemical process for extracting oil. A refining process was used to remove metal and chemical residues. Refined Castor Oil was filtered and degassed in order to minimize the dissolved gases, solid particles and moisture. A transesterification operation was performed to significantly reduce viscosity oil. Finally, obtained Castor Oil Methyl Esters (COME) are finally distilled in a rotary evaporator under vacuum to remove traces of water and methanol. Physicochemical properties as visual examination, relative density, kinematic viscosity, and acidity were measured in accord-ance with ASTM D6871. AC Breakdown voltage was performed according to IEC 60156, and had been analyzed using Weibull distribution. Processed Castor Oil (PCO) has low viscosity than certified transformer vegetable oils (BIOTEMP, FR3) and high Dielectric Strength (74.67 kV/2.5 mm). Partial Discharges characteristics including the Partial Discharge Inception Voltage and the Partial Discharge Propagation Voltage were also investigated according to the recommendations of IEC 61294. PCO has satisfactory properties for their use as an insulating oil for transformer.
Living on a Carbon Diet  [PDF]
Ghislain Dubois
Low Carbon Economy (LCE) , 2015, DOI: 10.4236/lce.2015.61003
Abstract: The objectives of this paper are to understand the features of simulated low carbon lifestyles under strong greenhouse gas emissions reduction assumptions (20%, 50%), the nature of trade-offs and the hierarchy of choices operated by households within a limited carbon and financial carbon budget, the acceptability of important changes in consumption patterns, and finally the values and representations, benefits and losses that households express in such changes. The research implemented a protocol combining experimental economy (simulation of carbon budget reductions under financial constraints) and anthropology (semi-structured interviews, to understand the rationale behind choices). Each household of the sample (n = 30) was investigated for 2 - 3 days. Firstly, a very detailed carbon footprint of the household was calculated. Then households were proposed a list of 65 pre-defined solutions covering most of available mitigation options, with financial and carbon cost and savings calculated for their real situation. The sample reached an average of -37% (-12%/-64%), with a preference to act on habitat and food and a reluctance to change transport consumption. Due to the amount of reductions asked, low carbon lifestyles finally impact comfort but allow saving money. Recommendations for policies are presented.
La absorción de la macroeconomía por la microeconomía*
Lecturas de Economía , 2008,
Abstract: the aim of this article is to analyze the dominant tendency in the history of macroeconomics. it attempts to identify the two routes that research on the microeconomic foundations of macroeconomics has followed. on the one hand, the relation between employment, wages and inflation (the route indicated by friedman); on the other hand, the existence of rigidities or a monetary restriction (the route indicated by clower).
Trust and diversity: a perspective of organisation
Ghislain Verstraete
Revista CIDOB d'Afers Internacionals , 2003,
Abstract: According to Ghislain Verstraete, we have been deaf and mute too long in the face of the consequences and dangers engendered by our “society of risk”, which he calls the “second modernity”. For everyone (but not in the same way), this second modernity is complex, stimulating, conflictive, as well as provocative in our limited competencies. In the face of the crisis, two reactions are possible: one of a diffuse pessimism which gives rise to a defensive and reactionary attitude, limiting citizen action; another one, of an excessive optimism which takes on an offensive tone, generating more questions and more negotiations and opening a perspective of empowerment. All the organisations have to position themselves in a permanent way in relationship to this defensive/offensive axis, not only in theory but also in practice. But, how can pluralism be conceptualised in this second modernity and how can it be put into practice?
La absorción de la macroeconomía por la microeconomía
Ghislain Deleplace
Lecturas de Economía , 2008,
Abstract: The aim of this article is to analyze the dominant tendency in the history of macroeconomics. It attempts to identify the two routes that research on the microeconomic foundations of macroeconomics has followed. On the one hand, the relation between employment, wages and inflation (the route indicated by Friedman); on the other hand, the existence of rigidities or a monetary restriction (the route indicated by Clower).
Holiness, remembrance and lineage of Cistercian abbesses in 13th c. Castile. Countess Urraca of Ca as (b. 1207-1262)
Baury, Ghislain
Anuario de Estudios Medievales , 2011,
Abstract: Countess Urraca is one of the main ladies of 13th-century Castile. Daughter of Diego López II de Haro (d. 1214), wife of count álvaro Nú ez de Lara (d. 1218), she spent her widowhood as abbess of Ca as (1222-1262), a monastery on which the Haro exerted the rights of patronage. After her death, the community celebrated the memory of an influent ruler who had decisively contributed to the influence and wealth of her institution. Then, probably around mid-15th century, at the instance of the general chapter of C teaux, the nuns gave her a fame of holiness that was recorded by the Cistercian authors in the first half of the 17th century. The cult of Blessed Urraca was reactivated during the 20th century because of the openings of her tomb, and the writing of a hagiography. The real course of her life was then distorted to such an extent that it is still poorly known today. [fr] La comtesse Urraca figure parmi les principales dames du XIIIe siècle castillan. Fille de Diego López II de Haro (m. 1214), épouse du comte álvaro Nú ez de Lara (m. 1218), elle exer a pendant son veuvage la charge d’abbesse du monastère de Ca as (1222-1262), sur lequel les Haro exer aient un droit de patronage. Après sa mort, la communauté célébra sa mémoire comme celle d’une supérieure influente qui avait contribué de fa on décisive au rayonnement et à la prospérité de son institution. Puis, vers le milieu du XVe siècle probablement, les religieuses la dotèrent, sous l’impulsion du chapitre général de C teaux, d’une réputation de sainteté qui fut enregistrée par les auteurs cisterciens du premier XVIIe siècle. Le culte de la bienheureuse Urraca fut réactivé au XXe siècle par les ouvertures de sa sépulture et la rédaction d’une hagiographie. Sa biographie fut alors déformée au point qu’elle demeure encore mal connue aujourd’hui.
Jean-Claude Monod, La querelle de la sécularisation. De Hegel à Blumenberg, Paris, Vrin (Problèmes et controverses), 2002, 30 euros.
Ghislain Waterlot
Astérion , 2005,
Abstract: Voici un livre qui compte, non seulement en tant qu’il apporte en France une belle et rigoureuse discussion d’auteurs qui n’étaient pas encore très diffusés dans le débat intellectuel hexagonal (Karl L with sans doute, mais surtout Hans Blumenberg dont l’ uvre majeure a été récemment et donc tardivement traduite en fran ais), mais aussi en tant qu’il permet d’éclairer une catégorie politique particulièrement complexe, très surdéterminée, et dont la complexité échappe d’autant plus facilement ...
Extended partial order and applications to tensor products
Ghislain Fourier
Mathematics , 2012,
Abstract: We extend the preorder on k-tuples of dominant weights of a simple complex Lie algebra g of classical type adding up to a fixed weight $\lambda$ defined by V. Chari, D. Sagaki and the author. We show that the induced extended partial order on the equivalence classes has a unique minimal and a unique maximal element. For k=2 we compute its size and determine the cover relation. To each k-tuple we associate a tensor product of simple g-modules and we show that for k=2 the dimension increases also along with the extended partial order, generalizing a theorem proved in the aforementioned paper. We also show that the tensor product associated to the maximal element has the biggest dimension among all tuples for arbitrary k, indicating that this might be a symplectic (resp. orthogonal) analogon of the row shuffle defined by Fomin et al. The extension of the partial order reduces the number of elements in the cover relation and may facilitate the proof of an analogon of Schur positivity along the partial order for symplectic and orthogonal types.
Weyl modules and Levi subalgebras
Ghislain Fourier
Mathematics , 2012,
Abstract: For a simple complex Lie algebra of finite rank and classical type, we fix a triangular decomposition and consider the simple Levi subalgebras associated to closed subsets of roots. We study the restriction of global and local Weyl modules of current algebras to this Levi subalgebra. We identify necessary and sufficient conditions on a pair of a Levi subalgebra and a dominant integral weight, such that the restricted module is a global (resp. a local) Weyl module.
PBW-degenerated Demazure modules and Schubert varieties for triangular elements
Ghislain Fourier
Mathematics , 2014,
Abstract: We study certain faces of the normal polytope introduced by Feigin, Littelmann and the author whose lattice points parametrize a monomial basis of the PBW-degenerated of simple modules for $\mathfrak{sl}_{n+1}$. We show that lattice points in these faces parametrize monomial bases of PBW-degenerated Demazure modules associated to Weyl group elements satisfying a certain closure property, for example Kempf elements. These faces are again normal polytopes and their Minkowski sum is compatible with tensor products, which implies that we obtain flat degenerations of the corresponding Schubert varieties to PBW degenerated and toric varieties.
Page 1 /142
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.