314 research outputs found
Un Nouveau Concept Baser Sur La Métallurgie Des Poudres Et Le Calcul Eléments Finis Pour Les Produits Biocompatibles
Résumé- Une nouvelle méthode de conception des produits biocompatibles comme les prothèses totales de hanche, est proposée. Des paramètres techniques sont prisent en compte sur le plan géométrique (design) et surtout sur le plan de matériau et calcul de résistance pour assurer la biocompatibilité de ce dernier. Cette méthodologie va permettre un gain en temps et en qualité.Mots clés- design, mode d’obtention, La métallurgie des poudres, processus, calcul de résistance, biomatériau, biocompatibilité
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Optimising Well-Being and Learning Through Participatory Processes and Practices::an International Comparative Analysis of Ten Groundwork Case-Studies in Schools
The paper presents a theory of participation in systems of learning that emerges from our evidence gathered through partnerships between schools and the academy. The theory identifies young people need to endorse common principles of participation to include and respect all. Educational leaders’ evidence informed intervention strategies can positively impact young people’s inclusive and respectful participation in the action-research. The theory of participation conceptualises young people’s need for opportunities to pursue their ambitions and interests. Leaders’ intervention strategies may develop young people’s participation in attaining target examination outcomes to achieve their ambitions. We then develop the theory of participation regarding young people pursuing independent interests and ambitions in association with the other, to enable them to be drivers of social change. To do this they need to understand their future identity as potential consumers, employees, employers, and entrepreneurs with Small and Medium Enterprises (SME) that challenge public corporations in a variety of ways. We theorise how young people are well situated to build capacity in Europe and globally using the social media networks they have already developed. Our evidence identified five participation principals of inclusion, respect, trust in the search for truth, constructive cross-cultural critique of alternative world views to arrive at a shared multicultural world view, and the generation of new knowledge to enable the re-imagining of new futures where young people are drivers of social change. From these principals we developed a theory of practice and four global standards as guidelines. First, a commitment to inclusionary partnerships and communities of practice. Second, distributed autonomy across stakeholders in the institution characterized by respect for individuals’ associated rights and responsibilities. Third, constructive cross-cultural criticism underpinned by trust in a search for truth, using different group’s constructed identity schema’s to develop a shared multicultural world view. Fourth, the generation of new knowledge through structures and mechanisms to optimize participation
Treatment of olive mill based wastewater by means of magnetic nanoparticles: Decolourization, dephenolization and COD removal
AbstractOlive mill wastewater (OMW) is an environmental concern that has been highlighted as a serious environmental problem in the Mediterranean basin countries because of its high organic load and phytotoxic and antibacterial phenolic compounds, which resist biological degradation. Consequently, this type of wastewater represents a huge challenge for the conventional wastewater treatment techniques as it can impact the lifetime of bacteria needed for the treatment. Iron-oxide nanoparticles are attractive for wastewater treatment for two important reasons. First, nanoparticles can remove pollutants from wastewater rapidly. Second, this magnetic type of nanoparticles could be separated easily using a magnet after finishing treatment process. In this study, we aimed at investigating the effectiveness of the magnetic iron oxide nanoparticles in the removal of large organic contaminants from OMW. Batch and continuous mode processes were applied on OMW treatment to determine the effect of contact time, solution pH, coexisting contaminants and the adsorption isotherm.The results showed that the adsorption was fast and the adsorption reached equilibrium within less than 30min. The adsorption equilibrium data fit very well to the Brunauer–Emmett–Teller (BET) Model, indicating multi-layers adsorption. The adsorption of major pollutants was associated to an efficient removal of coexisting contaminants such as heavy metals and free ions. The adsorption of OMW pollutants was dependent on pH of the solution. Finally, continuous-mode process was tested successfully using a packed bed column that combined sand filtration with magnetic nanoparticles to decolourize OMW effluent. This study will provide valuable insight on the effect of nanoparticles toward the treatment and recyclability of olive mill wastewater, which is crucial for the local olive mill industry. After seeing the successful achievement of integrating nanoparticles with fixed bed filtration, a preliminary process description and cost estimation of stand-alone plant (with a capacity of 4m3/h) for OMW treatment were considered in this study. Process capital and annual operating costs were estimated to be 476/year, respectively
Bamboo Application In Building Design : Case Study Of Green School, Bali, Indonesia
Bamboo has been known widely as a material for buildings since the dawn of the century. Nevertheless, bamboo is often regarded as a lowclass building material which has commonly used by low-income people. Since the issue of global warming and sustainability, bamboo became a focus for building material due to its sustenance and fast
growth in the natural environment. Architects and builders alike started to choose bamboo as an alternative to wood. Furthermore, it is difficult to get good-quality woods for construction and historically, a vast tract
of land has been ruined due to deforestation that caused an adverse effect on the surroundings. This paper attempts to discuss the properties of bamboo and how it is inventively applied in building design.
Descriptive-qualitative methods were used in this study to reveal an understanding of the application of bamboo in building design. To further enhance the finding and context of discussing a case study on how bamboo has been used in designing the structure in an innovative
organic form. The result from this research found out that bamboo is noble to be considered as an alternative material in building design due to its natural properties, exclusively for curvilinear organic-form
building that hardly achieved in steel and concrete
A Predictive Model for Steady State Ozone Concentration at an Urban-Coastal Site
Ground level ozone (O3) plays an important role in controlling the oxidation budget in the boundary layer and thus affects the environment and causes severe health disorders. Ozone gas, being one of the well-known greenhouse gases, although present in small quantities, contributes to global warming. In this study, we present a predictive model for the steady-state ozone concentrations during daytime (13:00–17:00) and nighttime (01:00–05:00) at an urban coastal site. The model is based on a modified approach of the null cycle of O3 and NOx and was evaluated against a one-year data-base of O3 and nitrogen oxides (NO and NO2) measured at an urban coastal site in Jeddah, on the west coast of Saudi Arabia. The model for daytime concentrations was found to be linearly dependent on the concentration ratio of NO2 to NO whereas that for the nighttime period was suggested to be inversely proportional to NO2 concentrations. Knowing that reactions involved in tropospheric O3 formation are very complex, this proposed model provides reasonable predictions for the daytime and nighttime concentrations. Since the current description of the model is solely based on the null cycle of O3 and NOx, other precursors could be considered in future development of this model. This study will serve as basis for future studies that might introduce informing strategies to control ground level O3 concentrations, as well as its precursors’ emissions
A Predictive Model for Steady State Ozone Concentration at an Urban-Coastal Site
Ground level ozone (O-3) plays an important role in controlling the oxidation budget in the boundary layer and thus affects the environment and causes severe health disorders. Ozone gas, being one of the well-known greenhouse gases, although present in small quantities, contributes to global warming. In this study, we present a predictive model for the steady-state ozone concentrations during daytime (13:00-17:00) and nighttime (01:00-05:00) at an urban coastal site. The model is based on a modified approach of the null cycle of O-3 and NOx and was evaluated against a one-year data-base of O-3 and nitrogen oxides (NO and NO2) measured at an urban coastal site in Jeddah, on the west coast of Saudi Arabia. The model for daytime concentrations was found to be linearly dependent on the concentration ratio of NO2 to NO whereas that for the nighttime period was suggested to be inversely proportional to NO2 concentrations. Knowing that reactions involved in tropospheric O-3 formation are very complex, this proposed model provides reasonable predictions for the daytime and nighttime concentrations. Since the current description of the model is solely based on the null cycle of O-3 and NOx, other precursors could be considered in future development of this model. This study will serve as basis for future studies that might introduce informing strategies to control ground level O-3 concentrations, as well as its precursors' emissions.Peer reviewe
A Predictive Model for Steady State Ozone Concentration at an Urban-Coastal Site
Ground level ozone (O3) plays an important role in controlling the oxidation budget in the boundary layer and thus affects the environment and causes severe health disorders. Ozone gas, being one of the well-known greenhouse gases, although present in small quantities, contributes to global warming. In this study, we present a predictive model for the steady-state ozone concentrations during daytime (13:00–17:00) and nighttime (01:00–05:00) at an urban coastal site. The model is based on a modified approach of the null cycle of O3 and NOx and was evaluated against a one-year data-base of O3 and nitrogen oxides (NO and NO2) measured at an urban coastal site in Jeddah, on the west coast of Saudi Arabia. The model for daytime concentrations was found to be linearly dependent on the concentration ratio of NO2 to NO whereas that for the nighttime period was suggested to be inversely proportional to NO2 concentrations. Knowing that reactions involved in tropospheric O3 formation are very complex, this proposed model provides reasonable predictions for the daytime and nighttime concentrations. Since the current description of the model is solely based on the null cycle of O3 and NOx, other precursors could be considered in future development of this model. This study will serve as basis for future studies that might introduce informing strategies to control ground level O3 concentrations, as well as its precursors’ emissions
Ectopic thymoma simulating a pericardial cyst
We present a case of a 53 year old man with a thymoma near the pericardium, a rare ectopic localisation of thymoma. A round radiodensity found at the right cardiophrenic angle was initially suspected at the echocardiography to be a pericardial cyst. The diagnosis of thymoma was made only after histopathological examination of the surgically re-sected lesion
Effect of short-acting beta blocker on the cardiac recovery after cardiopulmonary bypass
The objective of this study was to investigate the effect of beta blocker on cardiac recovery and rhythm during cardiac surgeries. Sixty surgical rheumatic heart disease patients were received esmolol 1 mg/kg or the same volume of saline prior to removal of the aortic clamp. The incidence of cardiac automatic re-beat, ventricular fibrillation after reperfusion, the heart rate after steady re-beat, vasoactive drug use during weaning from bypass, the posterior parallel time and total bypass time were decreased by esmolol treatment. In conclusion: Esmolol has a positive effect on the cardiac recovery in cardiopulmonary bypass surgeries
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