Ingénierie | EPFL Graph Search

L'ingénierie est l'ensemble des fonctions qui mènent de la conception et des études, de l'achat et du contrôle de fabrication des équipements, à la construction et à la mise en service d'une installation technique ou industrielle. Par extension, le terme est aussi souvent utilisé dans d'autres domaines : on parle par exemple d'ingénierie informatique ou d'ingénierie financière. Cette activité est actuellement exercée à titre principal par des sociétés dites « sociétés d'ingénierie » qui étudient, conçoivent et font réaliser tout ou partie d'un aménagement (portuaire, routier), d'un ouvrage (hôpital, usine) ou d'un équipement (tronçon d'Airbus, véhicule électrique). Le terme « ingénierie » est un terme introduit assez récemment dans la langue française, par abandon durant la moitié du du terme « génie », désignant l'art de l'ingénieur. Activité scientifique Ingénierie et STEM L’ingénierie est une activité rigoureuse de conceptualisation et de réalisation d'

Assessment of organic waste availability and suitability for the co-digestion of faecal sludge in Vietnam

Adeline Mertenat

This Master thesis comes within the framework of the PURR project (Partnership for Urban Resource Recovery), which is a collaboration between the Department of Water and Sanitation in Developing Countries (Sandec) at the Swiss Federal Institute of Aquatic Science and Technology (Eawag), the Institute of Environmental Science and Engineering (IESE) at the National University of Civil Engineering of Hanoi (HUCE), and the Laboratory for Environmental Biotechnology (LBE) at the Swiss Federal Institute of Technology Lausanne (EPFL). The PURR project is aiming to allow a comprehensive management of faecal sludge (FS) in Vietnamese urban areas. In that perspective, anaerobic co-digestion of FS with other type of organic waste is seen as a very promising technology. As the potential benefit from FS co-digestion is closely linked with the choice of co-substrates, this Master thesis was focusing on assessing the availability and suitability of potential co-substrates produced in the two case study cities Bac Ninh and Son La. By field research and interviews, a better understanding of the actual organic waste management was established. This showed that the actual organic waste management is not in favour of FS co-digestion as such. Indeed, all organic wastes separated at production source and therefore of high quality in terms of absence of impurities with disturbing effects, are already being reused, mainly as livestock feed. The remaining organic wastes are domestic waste, which cannot be used for anaerobic digestion (AD) process due to their high level of impurities related to their mixture with non-organic wastes. However, field research also revealed that rooms for improvements do exist for a better management of organic domestic waste. Nowadays they are most of the time dumped in landfills without any treatment. A segregation step would be really relevant to implement in order to decrease the related pollution and potential resource recovery of these valuable but underexploited wastes. Nevertheless, this would require political support from local authority in order to be efficient. Based on the organic waste assessment, co-treatment scenarios and related pros and constraints for FS co-digestion when considering the local context were developed. The use of segregated organic domestic waste came out to be the most sustainable scenario but is largely compromised by actual policy. The use of unfresh fruits and vegetables from market can be considered as the best compromise between technical and contextual constraints and would require less effort to be effective. In both scenarios, local support is a key factor for their effectiveness. Based on the results of the current report, the following statement can be deduced: If local support is provided, anaerobic co-digestion would be a relevant process for FS treatment. Otherwise, other treatment processes should be investigated.

2014

Tissue engineering for prenatal applications

Anna-Sofia Johanna Kiveliö

Fetal therapies have become available for a restricted number of life-threatening clinical conditions. Harnessing tissue engineering for prenatal applications has not been widely pursued even though isolating cells from fetal and extraembryonic tissues has been routinely done for years. The objectives of this thesis were twofold: i) the development of materials based and tissue engineering based strategies to prevent iatrogenic preterm prelabour rupture of fetal membranes (iPPROM) after diagnostic or therapeutic interventions into the amniotic cavity and ii) the generation of tissue substitutes from patient derived fetal cells, which can be employed for prenatal or perinanal transplantation to restore or replace defective tissues. For the prevention of iPPROM, mussel-mimetic tissue adhesive (mussel glue) a biomaterial which was recently described to not compromise cell viability and to have good tissue sealing capability was compared to fibrin glue. In this in vivo study we assessed whether in a mid-gestational rabbit model punctured fetal membranes could be efficiently sealed with mussel glue. Mussel glue showed comparable in vivo performance to fibrin glue in sealing fetal membranes though no apparent healing of the membranes could be observed in any of the samples. The limited ability of naturally derived scaffolds to promote fetal membrane healing inspired the engineering of synthetic plugging material with specifically tailored biological and mechanical properties which could activate the cells in the amnion and induce a healing response. In this thesis the modularly designed biomimetic poly(ethylene glycol) (PEG)-based hydrogel platform (called TG-PEG from here on) was used together with fetal cells to demonstrate that upon presentation of appropriate biological cues in 3D tissue mimicking environment, mesenchymal progenitor cells from amnion can be mobilized, induced to proliferate and supported in maintaining their native extracellular matrix production, thus creating a suitable environment for healing to take place. These data provide the basis for future engineering of materials with defined mechanical and biochemical properties and the ability to present migration and proliferation inducing factors, namely PDGF, bFGF, or EGF which could be key in resolving the clinical problem of iPPROM and allowing the field of fetal surgery to move forward. Cleft palate, where the bones of the palatal halves fail to fuse properly, is one of the most common birth defects. Tissue engineering has been envisioned as a treatment option but current approaches have been limited by the lack of i) appropriate autologous cell sources and ii) structural organization and vascularization. Tissue engineering of cleft palates using of autologous amniocentesis-derived and thus ethically unproblematic fetal amniotic fluid cells (AFCs) could be done parallel to the ongoing pregnancy with living reconstruction material being ready when the child is born. We describe using TG-PEG hydrogels to first evaluate 3D osteogenic differentiation of AFCs and creation of vascular structures from AFC derived endothelial cells (enAFC) and undifferentiated AFC either in random or organized channel cocultures in vitro and in vivo. Next, these approaches were combined in an osteogenic matrix with a channel perfused with enAFC and finally the integration and functional properties of these fetal bone constructs was tested in ectopic mouse model.

EPFL2015