98 research outputs found

    Investigation of Rheological and Geometric Properties Effect on Nonlinear Behaviour of Fluid Viscous Dampers

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    Global approval of the use of fluid viscous dampers to control the buildings response against dynamic loadings is growing. The idea behind incorporating additional dampers is that they will reduce most of the energy that is transmitted to the building during shaking event. The objective of this work is to identify and enhance the design parameters that control the nonlinear behaviour of fluid viscous damper subjected to sinusoidal excitation. For this, a numerical model of the flow inside the dissipater has been carried out based on finite volume method. A novel approach has been adopted to simulate elastic behaviour of the fluid, taking into account its compressibility by using the Murnaghan equation of state. A comparison between the calculations of the proposed model and the experimental tests was carried out. The model proved to be sufficiently accurate. A fluid flow analysis was then conducted to fully understand the internal mechanism of the damper. A parametric study was then performed by varying aspects such as dimensions, geometric relationships between components and fluid properties in order to better understand their effect on the non-linear behaviour of the device.  The results highlight the relationship between the parameters governing the shear thinning behaviour of the fluid and the non-linearity exponent of the damper. This makes it possible to better control the non-linear behaviour of the device by selecting the appropriate silicone oil and the appropriate geometric dimensions of its components

    Generating multimedia presentations: from plain text to screenplay

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    In many Natural Language Generation (NLG) applications, the output is limited to plain text – i.e., a string of words with punctuation and paragraph breaks, but no indications for layout, or pictures, or dialogue. In several projects, we have begun to explore NLG applications in which these extra media are brought into play. This paper gives an informal account of what we have learned. For coherence, we focus on the domain of patient information leaflets, and follow an example in which the same content is expressed first in plain text, then in formatted text, then in text with pictures, and finally in a dialogue script that can be performed by two animated agents. We show how the same meaning can be mapped to realisation patterns in different media, and how the expanded options for expressing meaning are related to the perceived style and tone of the presentation. Throughout, we stress that the extra media are not simple added to plain text, but integrated with it: thus the use of formatting, or pictures, or dialogue, may require radical rewording of the text itself

    Ba(H2PO3)2.0.5H2O: Synthesis, crystal structure optimization, vibrational study, DFT computation and application as a corrosion inhibitor

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    This investigation involved the synthesis of barium phosphite Ba(H2PO3)2.0.5H2O by reacting barium chloride with phosphorous acid. The physical characteristics, FT-IR spectra, and X-ray diffraction were employed to validate the composition of the synthesized substance, and powder X-ray diffraction (PXRD) was used to determine the phase purity. The optimal molecular geometry, infrared intensities were calculated using density functional theory (DFT/B3LYP) methods with the LanL2DZ basis set. The HOMO-LUMO properties and geometries of this compound have been determined and discussed. The computational structural parameters are generally in agreement with the experimental investigations. The theoretical infrared for the title compound has been constructed. Additionally, the anti-corrosion properties of this compound were investigated in an acidic solution using weight loss and electrochemical techniques. The results showed good effectiveness, indicating the formation of a protective film on the C38 surface

    Traitement peu invasif d’une breche osteo meningee associee a une hypertension intracranienne benigne

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    Description L’hypertension intracrânienne bénigne (HTICB) est une augmentation anormale de la pression intracrânienne non associée à un processus occupant de l’espace intracrânien, une thrombose des veinescérébrales ou une hydrocéphalie. Caractérisée par des céphalées invalidantes, des acouphènes pulsatiles, elle peut avoir une évolution péjorative et irréversible entraînant une cécité. La survenue d’une rhinorrhée spontanée dans un contexte d’HTICB a été décrite dans la littérature mais demeure peu fréquente. Objectif et cas cliniqueNous rapportons le cas d’une femme obèse âgée de 40 ans, qui a été admise pour rhinorrhée droite spontanée. Les explorations neuroradiologiques ont permis d’évoquer une hypertension intracrânienne bénigne sur une brèche ethmoïdale antérieure. Le monitoring de la pression a confirmé le diagnostic. Elle abénéficié d’une dérivation ventriculo péritonéale. L’évolution est favorable (disparition des symptômes) avec un delai de recul de 16 mois . Conclusion L’HTICB est une pathologie avec des conséquences irréversibles si le traitement n’est pas adéquat et rapide. En cas de rhinorrhée isolée dans le cadre de l’hypertension intracrânienne bénigne la dérivation ventriculo péritonéale est une attitude thérapeutique simple mais efficace

    Entrepreneurial intention among rural youth in Moroccan Agricultural Cooperatives: the future of rural entrepreneurship

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    Open Access Journal; Published online: 18 Aug 2021Rural entrepreneurship in the developing world has long been hailed as a powerful tool for promoting the socioeconomic integration of young people and the key to avoiding rural depopulation as well as ensuring these areas remain attractive places for rural youth. However, there have been no efforts to investigate the role of collective entrepreneurship in the creation and management of new businesses in Morocco. Furthermore, we build on the theory of planned behavior (TPB) to investigate and explain entrepreneurial intention among the rural youth members of agricultural cooperatives, and identify the vulnerabilities and factors that influence the choice or decision-making between permanent membership at the cooperative and an entrepreneurial career. In this case, we apply the cognitive approach to survey rural youth in the Drâa-Tafilalet region of Morocco in 2020. The binary logistic regression analysis technique has been used and applied to build the best model to explain why some rural youth members of the cooperative, but not others, choose to become entrepreneurs. We model how agricultural cooperatives may favor or inhibit the translation of entrepreneurial intention into new venture creation. A random sample size of 130 young people has been selected, from which 54 are intending to start a business and 76 have a negative intention of self-employment. The results of the analysis showed that socio-demographic variables, individual perceptions, previous experience, and the activities of the cooperative were statistically significant and reliable in building the binary logistic regression model. Findings also suggest that the risks of agribusiness and financing constraints have a negative influence on entrepreneurial intentions of the youth and women in agricultural cooperatives

    Corrosion Protection of Mild Steel in Hydrochloric Acid at 308 K using Benzimidazole Derivatives: Weight Loss, Adsorption and Quantum Chemical Studies

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    For the first time, the investigation and characterization of Benzimidazole derivatives, as a potential corrosion inhibitors for mild steel in acidic aqueous solutions has been reported. The inhibition efficiency was calculated based on the data using weight loss, surface studies and basic computational calculations. The values reported in this manuscript were 80% for P1 and 89 for P2. The adsorption of the inhibitors on the mild steel surface was found to obey the Langmuir’s adsorption isotherm. The results obtained from chemical and theoretical techniques are in good agreement with each other
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