Caractérisations optiques et microscopiques de la structure de membranes organiques d'ultrafiltration PDF Download

Author: Rahma Tamime
Publisher:
ISBN:
Category :
Languages : fr
Pages : 210

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Book Description
Afin d’améliorer la compréhension des effets des coagulants sur les performances des membranes organiques d'ultrafiltration employées dans la production d’eau potable, une caractérisation structurale complète (surface et volume) de l’échelle microscopique à l’échelle macroscopique des membranes (neuves, après filtration de coagulant et après lavage chimique) est utilisée. En premier lieu, les propriétés structurales des membranes planes neuves PES ont été déterminées en fonction du seuil de coupure. Les caractéristiques de surface (taille de pore et taux de remplissage) déterminées par le MEB et les caractéristiques en volume déterminées par l’ellipsométrie de speckle ont montré une évolution croissante avec le seuil de coupure. L’utilisation du LB et de l’AFM avec différentes fenêtres d’observation a montré que la détermination de la rugosité d'une membrane est bien fonction de l'échelle d’observation. L’AFM a permis de différencier les membranes selon leur seuil de coupure mais aussi selon les méthodes de fabrication. En second lieu, l’impact de la nature des coagulants en polychlorosulfate d'aluminium (PAX-XL 7A et Aqualenc F1) sur les propriétés structurales des membranes en PES 100 kDa a été abordé. L'utilisation du modèle d’Hermia et les analyses multi-échelle de la rugosité de surface ont montré que la filtration de suspensions de cogulants de PAX-XL 7A ou Aqualenc F1 produit un dépôt à la surface dû à l’adsorption et/ou la précipitation des produits d’hydrolyse de coagulants, provoquant une modification importante de la morphologie de surface de la membrane. Cette modification structurale est aussi révélée par des mesures du speckle de l’onde diffusée. Des analyses MEB et AFM ont révélé un changement de l’état de surface de la membrane lavées après colmatage. L’extension des techniques de caractérisation structurale, en particulier l'AFM, à l'étude des fibres creuses en AC et PVDF et leur vieillissement a montré une voie d’exploitation très intéressante.

Author: Satinder Kaur Brar
Publisher: Elsevier
ISBN: 0128030046
Category : Science
Languages : en
Pages : 530

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Book Description
Platform Chemical Biorefinery: Future Green Chemistry provides information on three different aspects of platform chemical biorefinery. The book first presents a basic introduction to the industry beneficial for university students, then provides engineering details of existing or potential platform chemical biorefinery processes helpful to technical staff of biorefineries. Finally, the book presents a critical review of the entire platform chemical biorefinery process, including extensive global biorefinery practices and their potential environmental and market-related consequences. Platform chemicals are building blocks of different valuable chemicals. The book evaluates the possibility of renewable feedstock-based platform chemical production and the fundamental challenges associated with this objective. Thus, the book is a useful reference for both academic readers and industry technical workers. The book guides the research community working in the field of platform chemical biorefinery to develop new pathways and technologies in combination with their market value and desirability. - Offers comprehensive coverage of platform chemicals biorefineries, recent advances and technology developments, potential issues for preventing commercialization, and solutions - Discusses existing technologies for platform chemicals production, highlighting benefits as well their possible adverse effects on the environment and food security - Includes a global market analysis of platform chemicals and outlines industry opportunities - Serves as a useful reference for both academic readers and industry technical workers

Author: Satinder Kaur Brar
Publisher: ASCE Press
ISBN: 9780784414088
Category : Nanotechnology
Languages : en
Pages : 642

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Book Description
This text presents the most current knowledge on the environmental impact of materials and products developed using nanotechnology. Although nanomaterials are revolutionising electronics, medicine, transportation and many other industries, they pose risks to living beings and ecosystems that are barely understood. Leading researchers here consider the science of nanomaterials, their behaviour in the environment, risk assessment and toxicology, and the future of nanomaterials.

Author: World Bank
Publisher: World Bank Publications
ISBN: 0821385631
Category : Social Science
Languages : en
Pages : 114

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Book Description
This report provides the most comprehensive and rigorous analysis of Iraqi income and expenditure in several decades. The report makes extensive use of the Iraq Household Socio-Economic Survey, the first nationwide income and expenditure survey since 1988. IHSES data is complemented income and expenditure data from a wide range of other measures of living standards, allowing us to analyze living standards in a holistic way. The analysis presented here was performed with two main goals first, to inform the Government s Poverty Reduction Strategy; and second, to serve as a baseline for future assessments of changes in living standards and the identification of critical issues for deeper examination. Iraqi living standards have two unusual characteristics. First, they have fallen over the past generation. Second, they feature surprisingly little inequality. These characteristics are both rooted in Iraq s recent history of authoritarian government, war, military occupation, insurgency, and civil strife leading to infrastructure destruction and population displacement. There have been few opportunities for individuals to prosper from professional or entrepreneurial activities. Decades of neglected investment have resulted in deterioration of social services and economic infrastructure. Consequently, individuals have lacked capabilities to prosper and an investment climate conducive to prosperity. School enrollment and life expectancy have declined. Extremely low returns to education reflect the combination of poor educational quality and lack of employment opportunities. In terms of economic infrastructure, access to reliable electricity and water, and even access to paved roads are low, are further reflections of decades of neglect. While the upper end of the distribution has been pulled down by a lack of opportunities, the lower end has been supported by direct government provision of food. The Public Distribution System (PDS) provides 85 percent of food needs. While PDS has been useful as a safety net for the poor and the vulnerable, the system is expensive, inefficient, and fiscally risky. Indeed, PDS food rations account for a far greater share of public spending than does education or health. Going forward, Iraq faces two main challenges. First, although Iraq does not have to develop from scratch, it faces a formidable challenge in re-development. Second, a shift by the Government is required from direct provision of basic subsistence toward investment in human capacities. The Government can provide an enabling environment through investments in economic infrastructure and services to business and citizens, thus allowing the population to make productive use of education and their own labor. Both challenges are now being taken up by the Poverty Reduction Strategy, which articulates a detailed set of required actions and outlines priorities for government spending.

Author: Christine Parent
Publisher: Springer Science & Business Media
ISBN: 354030326X
Category : Computers
Languages : en
Pages : 475

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Book Description
From environmental management to land planning and geo-marketing, the number of application domains that may greatly benefit from using data enriched with spatio-temporal features is expanding very rapidly. This book shows that a conceptual design approach for spatio-temporal databases is both feasible and easy to apprehend. While providing a firm basis through extensive discussion of traditional data modeling concepts, the major focus of the book is on modeling spatial and temporal information.