Search results for "History"

Robert de Montessus de Ballore's 1902 theorem on algebraic continued fractions : genesis and circulation

2013

Robert de Montessus de Ballore proved in 1902 his famous theorem on the convergence of Pad\'e approximants of meromorphic functions. In this paper, we will first describe the genesis of the theorem, then investigate its circulation. A number of letters addressed to Robert de Montessus by different mathematicians will be quoted to help determining the scientific context and the steps that led to the result. In particular, excerpts of the correspondence with Henri Pad\'e in the years 1901-1902 played a leading role. The large number of authors who mentioned the theorem soon after its derivation, for instance N\"orlund and Perron among others, indicates a fast circulation due to factors that w…

Long-term performance and life cycle assessment of energy piles in three different climatic conditions

2020

Abstract The main purpose behind the use of energy piles is to enable the exploitation of geothermal energy for meeting the heating/cooling demands of buildings in an efficient and environment-friendly manner. However, the long-term performance of energy piles in different climatic conditions, along with their actual environmental impacts, has not been fully assessed. In this paper, the results of a finite element model taking into consideration the heating and cooling demands of a reference building, and the intermittent operation of a ground source heat pump, are revealed to examine the long-term performance of energy piles. Furthermore, a life cycle assessment model is implemented to com…

Preventing the oil film instability in rotor-dynamics

2016

Horizontal rotor systems on lubricated journal bearings may incur instability risks depending on the load and the angular speed. The instability is associated with the asymmetry of the stiffness matrix of the bearings around the equilibrium position, in like manner as the internal hysteretic instability somehow, where some beneficial effect is indeed obtainable by an anisotropic configuration of the support stiffness. Hence, the idea of the present analysis is to check if similar advantages are also obtainable towards the oil film instability. The instability thresholds are calculated by usual methods, such as the Routh criterion or the direct search for the system eigenvalues. The results …

Direct Torque Control of a Small Wind Turbine with a Sliding-Mode Speed Controller

2016

In this paper. the method of direct torque control in the presence of a sliding-mode speed controller is proposed for a small wind turbine being used in water heating applications. This concept and control system design can be expanded to grid connected or off-grid applications. Direct torque control of electrical machines has shown several advantages including very fast dynamics torque control over field-oriented control. Moreover. the torque and flux controllers in the direct torque control algorithms are based on hvsteretic controllers which are nonlinear. In the presence of a sliding-mode speed control. a nonlinear control system can be constructed which is matched for AC/DC conversion …

Beyond cells – The virome in the human holobiont

2019

Viromics, or viral metagenomics, is a relatively new and burgeoning field of research that studies the complete collection of viruses forming part of the microbiota in any given niche. It has strong foundations rooted in over a century of discoveries in the field of virology and recent advances in molecular biology and sequencing technologies. Historically, most studies have deconstructed the concept of viruses into a simplified perception of viral agents as mere pathogens, which demerits the scope of large-scale viromic analyses. Viruses are, in fact, much more than regular parasites. They are by far the most dynamic and abundant entity and the greatest killers on the planet, as well as th…

Me, My Bot and His Other (Robot) Woman? Keeping Your Robot Satisfied in the Age of Artificial Emotion

2018

With a backdrop of action and science fiction movie horrors of the dystopian relationship between humans and robots, surprisingly to date-with the exception of ethical discussions-the relationship aspect of humans and sex robots has seemed relatively unproblematic. The attraction to sex robots perhaps is the promise of unproblematic affectionate and sexual interactions, without the need to consider the other&rsquo

Construcción de puentes y avenidas fluviales: algunos debates técnicos en el academicismo ilustrado del Reino de Valencia

2020

Con el afianzamiento de las políticas reformistas y la consolidación de las academias de bellas artes, durante el último tercio del siglo XVIII se desarrolló una creciente polémica entre los arquitectos y los maestros de obra en torno a la proyección y diseño de obra civil, particularmente la relacionada con ambientes fluviales. En este artículo se valora, con diferentes ejemplos, la incidencia de este debate en la proyección de puentes y su capacidad de resistencia a las avenidas fluviales. During the last third of the 18th century, reformist policies and the consolidation of the fine arts academies were consolidated. This fact affected the architects and the master builders with a policy …

Rodzinna postpamięć Ślązaków

2017

Family Postmemory of the People of Silesia
 The author suggests a possible use of postmemory to analyse the contemporary family memory of the people of Silesia. Their memoirs about WW2 (such as working for the Wehrmacht, the Red Army invading Silesia, working in labour camps, nationality verification, displacements to Germany, and deportations to Siberia) bear signs of latent memory which is rarely revealed even to the next of kin. Present mainly within the family circle, within the local society, and among friends, these memoirs integrated Silesians and made them a unique community that considers itself a stigmatized minority. This contributed to mythologizing and stereotyping the who…

Miracles in Dark Times: Hannah Arendt and Refugees as ‘Vanguard’

2019

AbstractThe radical uncertainty that refugees face because of war, flight and exile often dramatically shapes their participation in society. Violent conflict and human rights abuses are not just disproportionately experienced by, but can also create, political subjects. Such life events can transform the motivations, sense of responsibility and political actions of individuals with refugee backgrounds. In this article, we explore the links between civil–political engagement and the life stories of such individuals, analysing our empirical data through themes in the work of Hannah Arendt. We make three central points. First, we highlight the possibility of refugees as ‘vanguard’, playing a …

2018

Abstract Disaster diplomacy investigates how and why disaster-related activities do and do not influence conflict and cooperation. Studies into the topic so far have tended to develop the theory, analyse a specific case study in space and time, or connect both. Explorations of disaster diplomacy case studies over the long-term are so far absent from the literature. This paper explores Jammu and Kashmir in the Himalaya as a long-term case study for disaster diplomacy. Jammu and Kashmir has a long history of conflicts, multiple environmental hazards, and significant vulnerabilities yielding major disasters, with each topic generally addressed separately in the literature. This paper explores …