677 research outputs found
Zero-Temperature Relaxation in Spin-Polarized Fermi Systems
The effect of zero-temperature attenuation, which has been recently observed in spin dynamics of Fermi liquids, on various processes in helium and ferromagnetic systems is described. A brief review of theoretical and experimental data on zero-temperature attenuation in transverse spin dynamics of helium systems is followed by a discussion of coupling between longitudinal and transverse processes, the Castaing instability in 3He and 3Heâ4He mixtures, and applications to pure ferromagneticmetals
Code vs. Code: Nationalist and Internationalist Images of the Code Civil in the French Resistance to a European Codification
French academics reacted to announcements about a possible future European civil code ten years ago in the way in which Americans reacted to the Japanese attack on Pearl Harbor 1940: first with shock, then with rearmament, finally with attempted counterattacks. Military metaphors abound. Yet the defense of the French Code Civil against a European civil code is tricky: they must defend one Code against another. The images drawn of codes are therefore of particular interest for our understanding both of civil codes and of legal nationalism. Often, two mutually exclusive images are presented at the same time. In cultural terms, the code civil is both traditional and revolutionary, both linguistically determined and independent of its language, both an expression of values and merely formal and neutral. Politically, the code civil is legitimated both in democracy and technocracy, it expresses both self-determination and imperialism, it is about both pluralism and universalism. Necessarily, in such juxtapositions, the same characteristics must be assigned to a European Code, making the arguments ultimately self-refuting. Nonetheless, the point is not to dismiss these defenses. Rather, they should be understood as expressions of faithâand the discussion over a European Code resembles, in part, a religious war
Uncovering latent singularities from multifractal scaling laws in mixed asymptotic regime. Application to turbulence
In this paper we revisit an idea originally proposed by Mandelbrot about the
possibility to observe ``negative dimensions'' in random multifractals. For
that purpose, we define a new way to study scaling where the observation scale
and the total sample length are respectively going to zero and to
infinity. This ``mixed'' asymptotic regime is parametrized by an exponent
that corresponds to Mandelbrot ``supersampling exponent''. In order to
study the scaling exponents in the mixed regime, we use a formalism introduced
in the context of the physics of disordered systems relying upon traveling wave
solutions of some non-linear iteration equation. Within our approach, we show
that for random multiplicative cascade models, the parameter can be
interpreted as a negative dimension and, as anticipated by Mandelbrot, allows
one to uncover the ``hidden'' negative part of the singularity spectrum,
corresponding to ``latent'' singularities. We illustrate our purpose on
synthetic cascade models. When applied to turbulence data, this formalism
allows us to distinguish two popular phenomenological models of dissipation
intermittency: We show that the mixed scaling exponents agree with a log-normal
model and not with log-Poisson statistics.Comment: 4 pages, 3 figure
Normal integrands and related classes of functions
summary:Let , where is a measurable space, and a topological space. We study inclusions between three classes of extended real-valued functions on which are upper semicontinuous in and satisfy some measurability conditions
The contemplative style in the ethnographic documentary between observation and immersion
The author draws the field of a documentary style he calls
âcontemplativeâ essentially based on long shots, long takes, limited
montage and absence of dialogues. The precursor signs of this style
are indicated by Marano in the observational cinema, particularly in
some of David MacDougallâs films, and then continued in the production
of anthropological documentary filmmakers at Harvardâs Sensory
Ethnography Lab. The enunciative modes of the contemplative style
do not lead back to contemplation as an activity of the mind, but are
a rhetorical strategy to overcome oculocentrism, give way to the other
senses and convert contemplation to immersion
Sensitivity analysis and optimization of a compressed air energy storage (CAES) system powered by a photovoltaic plant to supply a building
International audienceOne of the handicaps of the large-scale integration of solar energy is due to its variability and its intermittency. The main way to overcome this issue is the energy storage technology. Knowing the high cost of batteries and their impact on the environment, we simulate a storage system based on compressed air and acting as a battery system. The CAES consists in storing the air at a high pressure in a tank during the period when the energy source is abundant, i.e., cheap, or when the energy demand is low. The compressed air is later expanded through an air turbine which generates electricity during the high demand periods, i.e. when the energy source becomes very expensive for instance. This system could be used for decentralized electricity supply or in an area with no electric grid. In order to evaluate the feasibility of a Compressed Air Energy Storage system coupled to a photovoltaic plant and a building that represents a reduced power demand, a numerical model that reflects the instant behaviour has been built. The system is composed of a photovoltaic power plant, an air compression system, a storage vessel, an expansion module, a power grid and a building. The inputs used are, on the one hand, the climate data such as ambient temperature and the global solar irradiation and, on the other hand, the load curve of a building or of the group of buildings, which has to be supplied by electricity. The overall system optimization has then been performed after having done a sensitivity analysis of the key parameters. This optimization allows us to find the most suitable size for each component of the system: compressor, tank size and photovoltaic area. Abstract One of the handicaps of the large-scale integration of solar energy is due to its variability and its intermittency. The main way to overcome this issue is the energy storage technology. Knowing the high cost of batteries and their impact on the environment, we simulate a storage system based on compressed air and acting as a battery system. The CAES consists in storing the air at a high pressure in a tank during the period when the energy source is abundant, i.e., cheap, or when the energy demand is low. The compressed air is later expanded through an air turbine which generates electricity during the high demand periods, i.e. when the energy source becomes very expensive for instance. This system could be used for decentralized electricity supply or in an area with no electric grid. In order to evaluate the feasibility of a Compressed Air Energy Storage system coupled to a photovoltaic plant and a building that represents a reduced power demand, a numerical model that reflects the instant behaviour has been built. The system is composed of a photovoltaic power plant, an air compression system, a storage vessel, an expansion module, a power grid and a building. The inputs used are, on the one hand, the climate data such as ambient temperature and the global solar irradiation and, on the other hand, the load curve of a building or of the group of buildings, which has to be supplied by electricity. The overall system optimization has then been performed after having done a sensitivity analysis of the key parameters. This optimization allows us to find the most suitable size for each component of the system: compressor, tank size and photovoltaic area
Hilar Biliary Cancer â are We Getting it Right?
Recent reviews of the management of hilar biliary cancer suggest that radical resection is the preferred
treatment option. It seems true that most of the long term survivors are treated this way, but it is equally
true that most patients receive palliative rather than curative treatment. Before we go too far in our
advocacy of radical treatment, we need to develop methods for quantifying palliation because that is in
truth what we usually achieve. A method of quantifying palliation is described. Surgeons are encouraged
to use methods of this kind in order to allow valid comparison of the results of different methods of
treatment
Center City Southeast
Center City Southeast is a multi-media performance comprised of sound, video, and short stories. The performance tracks a series of incidental encounters in placesâplaces in which I just happened to be. In the piece, I blend text, video, and sound into a cohesive whole and illuminate surprising relationships between disparate elements. The storiesâwritten accounts of both real and fictionalized encountersâact as guideposts. They articulate uncanny feelings and highlight strange occurrences with memory, nature, and doppelgangers that I experienced while recording the sounds and sights of my environment. Moreover, the sound, video and text trace moments when the banal slips into the bizarre, capturing a broad collection of moments that range from the utterly familiar to the deeply uncanny
Resultados a largo plazo de la patelectomĂa total
Desde el año 1981 hemos realizado 19 patelectomĂas totales, 9 por artrosis femoropatelar,
8 por dolor anterior de rodilla y 2 por fracturas conminutas. La edad media en el momento
de la intervenciĂłn era de 48 años (25-80); todos los pacientes con dolor anterior habĂan sido
operados previamente. Con una evolución media de 7,8 años (3-14), hemos realizado una revisión
clĂnica y radiolĂłgica. SegĂșn la escala de la Sociedad Internacional de Rodilla obtuvimos un
58% de resultados excelentes y buenos, resaltando que continĂșan con dolor todos los pacientes
operados por artrosis y el 50% de los intervenidos por dolor anterior. La patelectomĂa total es una
técnica cada vez menos utilizada, limitåndose sus indicaciones a fracturas muy conminutas, artrosis
femoropatelar en pacientes en los que estarĂa contraindicada la artroplastia total y en cuadros
de dolor anterior de rodilla rebeldes a otros tratamientosNineteen total patelectomies were performed since 1981. The indication was femoropatellar
osteoarthritis in nine cases, anterior knee pain syndrome in eight, and conminute
fractures in two. The mean age of the group at the time of operation was 48 years (25-80). A1l the
patients with anterior knee pain syndrome had been operated previously. With an average followup
time of 7.8 years (3-14), vve reviewed our patients clinically and radiographically. We used the
International Knee Society rating scale and found 58% of excellent and good results; 100% of the
patients operated because of osteoarthritis and 50% of those operated because an anterior knee
pain syndrome have pain at review. Total patellectomy is not a frequent technique. Today, the sole
indications are very conminute fractures of the patella, femoropatellar osteoarthritis in those patients
in which total knee arthroplasty is not indicated and in the anterior knee pain syndrome
not improved with other treatments
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