Modeling growth, lipid accumulation and lipid turnover in submerged batch cultures of Umbelopsis isabellina

The production of lipids by oleaginous yeast and fungi becomes more important because these lipids can be used for biodiesel production. To understand the process of lipid production better, we developed a model for growth, lipid production and lipid turnover in submerged batch fermentation. This model describes three subsequent phases: exponential growth when both a C-source and an N-source are available, carbohydrate and lipid production when the N-source is exhausted and turnover of accumulated lipids when the C-source is exhausted. The model was validated with submerged batch cultures of the fungus Umbelopsis isabellina (formerly known as Mortierella isabellina) with two different initial C/N-ratios. Comparison with chemostat cultures with the same strain showed a significant difference in lipid production: in batch cultures, the initial specific lipid production rate was almost four times higher than in chemostat cultures but it decreased exponentially in time, while the maximum specific lipid production rate in chemostat cultures was independent of residence time. This indicates that different mechanisms for lipid production are active in batch and chemostat cultures. The model could also describe data for submerged batch cultures from literature well

eMersion: A New Paradigm for Web-Based Training in Mechanical Engineering Education

The Board of the Swiss Federal Institutes of Technology has launched in 2000 a new programme to promote the use of New Learning Technologies (NLT) at the Swiss Federal Institutes of Technology. The goal of this programme is to encourage a reform of traditional teaching through the innovative application of Information and Communication Technologies. In this framework, the Mechanical Engineering Department at the Swiss Federal Institute of Technology in Lausanne (EPFL) has started the eMersion project, a multidisciplinary effort to deploy innovative pedagogical scenarios and flexible learning resources for carrying out virtual and real experiments via the Internet. The eMersion project aims at promoting a pedagogical trial-and-error paradigm by enhancing the opportunities for engineering trainees to carry out extensive experimentation in their education curriculum. The proposed approach relies on the benefits to be gained from alternative means of experimentation that allow the students to reinforce their understanding of physical phenomena in a framework where errors are neither penalized nor hazardous. The production of practice-oriented pedagogical components is directed toward the use of various existing tools to provide students with facilities to experiment through simulations, virtual and enhanced reality based manipulations as well as remote manipulations of laboratory setups. In the first part of this paper, the revised pedagogical scenarios that are envisioned for further deployments in automatic control, fluid mechanics and biomechanics are presented. Those three expertise domains of the Mechanical Engineering Department have been selected as trial candidates due to their respective needs for more flexible and practice-oriented facilities. In the second part of this paper, the NLT resources enabling the eMersion paradigm are introduced. The key components are Web-based documents describing the experimental setups and the protocols to be carry out, cockpit-like GUIs for running the virtual or real experiments in a highly interactive manner, and last but not least an original electronic journal shared by a team of students that collaborate to fulfill the hands-on sessions requirements

The Electronic Laboratoty Journal: A Web-Based Collaborative Environment for Remote Experimentation

The Electronic Laboratory Journal: A Web-Based Collaborative Environment for Remote Experimentation Georgios Fakas, and Denis Gillet Numerous tools have been developed that support the collaboration between students in education, tools that mainly include facilities for sharing documents and enabling discussions. However, these environments do not emphasize the use of facilities that sustain collaborative work in the framework of remote experimentation carried out by a group of students located at different places. We propose the Electronic Laboratory Journal paradigm, as a collaborative and cooperative environment for remote experimentation in engineering education. The Electronic Laboratory Journal enhances the traditional laboratory journal, by providing a group of students with Web-based tools to maintain notes in order to remotely complete their experimentation assignment by collecting, discussing, exchanging or sharing information and also by documenting and finally submitting their results to their educators. Notes may be composed of numerous objects of any format, such as text, images, graphics, manuscripts, measurement logs or simulation results. The Laboratory Journal also facilitates educators to remotely supervise, assist and tutor the progression of students with their learning activities. The Electronic Laboratory Journal paradigm is currently validated in the framework of the eMersion project, which aims at developing at EPFL (the Swiss Federal Institute of Technology Lausanne) hands-on resources for flexible learning in engineering education focusing on remote manipulation of real setups and web-based simulation facilities. The Laboratory Journal is designed to be an open and reusable Web-based application. For this reason, XML and Java technologies are deployed. This paper presents the Electronic Laboratory Journal environment, its application and validation in the eMersion project, its pedagogical benefits, and its technical peculiarities. Index Terms Knowledge Engineering, Collaborative Learning, Distance Learning, Web-Based Experimentation