Hydrodynamics-Biology Coupling for Algae Culture and Biofuel Production

International audienceBiofuel production from microalgae represents an acute optimization problem for industry. There is a wide range of parameters that must be taken into account in the development of this technology. Here, mathematical modelling has a vital role to play. The potential of microalgae as a source of biofuel and as a technological solution for CO2 fixation is the subject of intense academic and industrial research. Large-scale production of microalgae has potential for biofuel applications owing to the high productivity that can be attained in high-rate raceway ponds. We show, through 3D numerical simulations, that our approach is capable of discriminating between situations where the paddle wheel is rapidly moving water or slowly agitating the process. Moreover, the simulated velocity fields can provide lagrangian trajectories of the algae. The resulting light pattern to which each cell is submitted when travelling from light (surface) to dark (bottom) can then be derived. It will then be reproduced in lab experiments to study photosynthesis under realistic light patterns

Towards Our Common Digital Future. Flagship Report.

In the report “Towards Our Common Digital Future”, the WBGU makes it clear that sustainability strategies and concepts need to be fundamentally further developed in the age of digitalization. Only if digital change and the Transformation towards Sustainability are synchronized can we succeed in advancing climate and Earth-system protection and in making social progress in human development. Without formative political action, digital change will further accelerate resource and energy consumption, and exacerbate damage to the environment and the climate. It is therefore an urgent political task to create the conditions needed to place digitalization at the service of sustainable development

The World We Want to Live In

Digitalisation, digital networks, and artificial intelligence are fundamentally changing our lives! We must understand the various developments and assess how they interact and how they affect our regular, analogue lives. What are the consequences of such changes for me personally and for our society? Digital networks and artificial intelligence are seminal innovations that are going to permeate all areas of society and trigger a comprehensive, disruptive structural change that will evoke numerous new advances in research and development in the coming years. Even though there are numerous books on this subject matter, most of them cover only specific aspects of the profound and multifaceted effects of the digital transformation. An overarching assessment is missing. In 2016, the Federation of German Scientists (VDW) has founded a study group to assess the technological impacts of digitalisation holistically. Now we present this compendium to you. We address the interrelations and feedbacks of digital innovation on policy, law, economics, science, and society from various scientific perspectives. Please consider this book as an invitation to contemplate with other people and with us, what kind of world we want to live in

South Africa’s peaceful use of nuclear energy under the nuclear non-proliferation treaty and related treaties

Energy is the natural power stored in matter which can be potential and kinetic energy. This occurs in nature in various forms such as chemical energy, thermal energy, electromagnetic radiation, gravitational energy, electric energy, elastic energy, nuclear energy, and rest energy. The scientific research relating to nuclear energy has revealed that atoms are the foundation of matter. In 1905 Albert Einstein initiated the quantum revolution utilising the Newtonian mass-energy equivalence concept in order to put his famous equation: E =mc2, where energy is (E). This facilitated the nuclear research which focused on manufacturing the first atomic bomb. In 1945 the USA acquired its first two atomic bombs which were dropped on Nagasaki and Hiroshima, killing 200 000 people; mostly civilians. But nuclear energy research has been redirected by scientists in order to industrialise nuclear technology in order to address growing power needs. This encouraged policy makers to consider the risks posed by utilising nuclear energy for civil purposes. The shift towards peaceful nuclear energy applications has been motivated by the many valuable contributions to humankind which nuclear energy offers - for instance in the fields of energy generation, human health, agriculture and industry. The nature of nuclear energy lends itself to becoming an important component of the world energy and global economic system. Nuclear energy is a viable option for many countries including South Africa, because it offers an economic and clean source of electricity; the primary engine for socio-economic development. South Africa operates the only two nuclear power reactors in Africa, (Koeberg 1 and Koeberg 2) generating 1.8 GWe. South Africa’s energy supply infrastructure consists fundamentally of coal-fired power plants which pose serious threats to the environment. Therefore, it is assumed that the planned 9.6 GW of new nuclear capacity by 2030 will meet the requirements of South Africa’s policy regarding the diversification of available energy resources to secure energy supply, support economic growth, and contribute to environmental management. Consequently, the legal system which governs nuclear energy programme is intended to prohibit the proliferation of nuclear weapons, ensure security and maintain the safe operation of nuclear facilities.Public, Constitutional, and International LawLL. D

(Re)Placing America: Cold War Mapping and the Mediation of International Space

The United States emerged from World War II as an undeniably global power, and as the Cold War unfolded, America faced decisions about where to place and display its power on the globe. The Cold War was a battle between two ideologies and competing world systems, both of which were vying for space and had the tools and technologies to control those spaces. Maps became a central vehicle for the testing of these new boundaries. Mapping projects and programs emerged from a variety of popular cartographers, foreign policy strategists, defense leaders, Congressional representatives, scientists, oppositional movements, labor unions, educational publishers, even everyday citizens. As each of these sources confirms, the scope of American commitments had expanded considerably; to account for this expansion, a cartographic impulse underwrote the continually evolving Cold War, and the tensions of art and science, realism and idealism, and space and place inherent in this impulse helped form the fault lines of the conflict. (Re)Placing America looks largely at the ways that cartography adapted to such changes and tensions in the second half of the twentieth century, and how the United States marshaled the practice of mapping in a variety of ways to account for the shift to internationalism. This dissertation explores how cartography mediated visions of space, and particularly, how it defined America's place within those spaces. Treating cartography as a complex rhetorical process of production, display, and circulation, the five chapters cover major geopolitical thematics, and the responding evolution of maps, from World War II until the Cold War's end in the early 1990s. Some of these driving themes include the "air-age" expansion of visual perspectives and strategic potential in journalistic maps; the appropriation of cartography as a medium for intelligence and national security objectives; the marshaling of maps as evidential weapons against the Soviet Union in diplomatic exchanges, Congressional reports, and government-sponsored propaganda; the shifts from East/West antagonisms to North/South ones as cartography was drafted into the modernization efforts of the U.S. in mapping the Third World; and the Defense Department's use of maps to argue for nuclear deterrence, while protest groups made radical cartographic challenges to these practices of state power. (Re)Placing America reads closely the maps of the forty-years-plus conflict and considers the complexity of their internal codes (in colors, shapes, icons, etc.), while also reaching out externally to the intersecting interests and visions of the cartographic producers and the Cold War contexts in which they emerged. The project seeks out and explores particular nodal points and thematics where maps consolidated and shaped changing shifts in perception, where cartographic fragments cohered around the defining moments, but also sometimes in the everyday politics of the Cold War. Ultimately, this project offers four conclusions about and conduct and operation of American mapping during the complex, ideologically charged time of the Cold War. First, the function of the map to both "fix" and "unfix" particular perceptions of the world is relevant to assessing how America sought to stabilize its place in a rapidly changing world. Second, the internationalism of the Cold War was bound up in the capacities for cartography to document and adapt to it. Third, the humanistic notion of a geographical imagination is central to understanding why particular Cold War agents and institutions continually drew on cartography to represent their interests. Finally, combining an ideological approach to reading maps as articulators of contextual tensions and historical ideas with an instrumental approach to maps as material, strategic documents can best help to situate cartography as an ongoing process of production, circulation, and display

Amsterdam human capital

The familiar shape of western cities is changing dramatically. For long times the urban core was taken for granted as the focal point for international contacts and day-to-day activities in the region. Currently, the urban scope is transforming into multi centred forms at metropolitan scale. The transition is not just a matter of spatial form, it is reflecting social, economic and cultural processes. The question is what new identities may develop in such changing historical conditions of space and place. The book is a first attempt to analyse the process of urban transformation in an integral way. The focus is on the region of Amsterdam. All contributions are written by senior researchers of the Amsterdam studycentre for the Metropolitan Environment (AME). AME is the interdisciplinary urban research institute of the Universiteit van Amsterdam. As the urban research institute at the Universiteit van Amsterdam, the Amsterdam studycentre for the Metropolitan Environment (AME) analyses the economic, social and cultural aspects of this spatial transformation, usually in international comparative research. All contributions to this book are written by senior researchers of AME in an attempt to analyse in an integral way the present and future dilemmas out of the historical growth paths of this dynamic city

A year in the life of the primary head teacher

This study was conducted to establish patterns of Primary Head Teacher behaviour over a complete school year, including weekends and holidays. Certain aspects of the role of the Primary Headteacher were also investigated. Two Head Teachers kept diaries, recording daily the nature of activities being undertaken and the length and frequency of them. A group of 25 Head Teachers also participated by completing diaries for periods of 2 weeks each - at different times of the year. The diaries were analysed by classifying recorded activities against category criteria, which had been agreed and devised with the Head Teachers prior to the commencement of the project. The evidence, once interpreted and collated, was brought to the attention of the two principal respondents one year after their diaries had been completed to assess their response and seek their views. This was repeated after a further period of twelve months had elapsed. The study shows that Primary Head Teachers' behaviour is characterised by long hours spent on multifarious tasks and activities of varying importance, with frequent interruptions and often brief duration. One of the main diary keepers was an experienced Head Teacher, the other was beginning her first Headship, whilst the remaining Head Teachers had a range of experience. The total amounts of time devoted to school-related issues, the range of activities being undertaken and the frequency of activity change were remarkably similar for all Head Teachers. Head Teachers bring experience, knowledge, skills, beliefs, attitudes and values to their schools and attempt to recreate these in the hearts and minds of those associated with their schools