1,831 research outputs found
Red Golem: Criticism of Industrial Civilization in Soviet Culture and Misticism During the Civil War
This article describes an early Soviet version of the critique of the industrial culture, based on the works by Alexander Bogdanov and George Gurdjieff. Bogdanov’s analysis of Taylorism is explored within the context of the development of the concept of ‘proletarian culture’. Terminological apparatus of George Gurdjieff’s theory is described as a form of radical criticism of the early XXth-century culture. We also highlight the place of the ‘man-machine’ metaphor within the intellectual life of the post-revolutionary Soviet Russia.
Keywords: Taylorism, Soviet culture, 1919, А. Bogdanov, proletarian culture, G. Gurdjief
Essential spectra and exponential estimates of eigenfunctions of lattice operators of quantum mechanics
This paper is devoted to estimates of the exponential decay of eigenfunctions
of difference operators on the lattice Z^n which are discrete analogs of the
Schr\"{o}dinger, Dirac and square-root Klein-Gordon operators. Our
investigation of the essential spectra and the exponential decay of
eigenfunctions of the discrete spectra is based on the calculus of so-called
pseudodifference operators (i.e., pseudodifferential operators on the group
Z^n) with analytic symbols and on the limit operators method. We obtain a
description of the location of the essential spectra and estimates of the
eigenfunctions of the discrete spectra of the main lattice operators of quantum
mechanics, namely: matrix Schr\"{o}dinger operators on Z^n, Dirac operators on
Z^3, and square root Klein-Gordon operators on Z^n
Liberty, Equality and Not Too Much Fraternity: An Experience in Practical Application of Liberal Education Teaching Techniques
The paper explores an experience in practical application of liberal education teaching techniques. We describe the most frequently used techniques and present sample classroom assignments based on this framework. We also discuss the opportunities and limitations provided by the use of these methods in a classroom setting.
Keywords: teaching techniques, liberal education, writing and analytical reading, humanities teaching
Pattern formation without heating in an evaporative convection experiment
We present an evaporation experiment in a single fluid layer. When latent
heat associated to the evaporation is large enough, the heat flow through the
free surface of the layer generates temperature gradients that can destabilize
the conductive motionless state giving rise to convective cellular structures
without any external heating. The sequence of convective patterns obtained here
without heating, is similar to that obtained in B\'enard-Marangoni convection.
This work present the sequence of spatial bifurcations as a function of the
layer depth. The transition between square to hexagonal pattern, known from
non-evaporative experiments, is obtained here with a similar change in
wavelength.Comment: Submitted to Europhysics Letter
Essential spectra of difference operators on \sZ^n-periodic graphs
Let (\cX, \rho) be a discrete metric space. We suppose that the group
\sZ^n acts freely on and that the number of orbits of with respect to
this action is finite. Then we call a \sZ^n-periodic discrete metric
space. We examine the Fredholm property and essential spectra of band-dominated
operators on where is a \sZ^n-periodic discrete metric space.
Our approach is based on the theory of band-dominated operators on \sZ^n and
their limit operators.
In case is the set of vertices of a combinatorial graph, the graph
structure defines a Schr\"{o}dinger operator on in a natural way. We
illustrate our approach by determining the essential spectra of Schr\"{o}dinger
operators with slowly oscillating potential both on zig-zag and on hexagonal
graphs, the latter being related to nano-structures
Possibility of measuring the thermal Casimir interaction between a plate and a cylinder attached to a micromachined oscillator
We investigate the possibility of measuring the thermal Casimir force and its
gradient in the configuration of a plate and a microfabricated cylinder
attached to a micromachined oscillator. The Lifshitz-type formulas in this
configuration are derived using the proximity force approximation. The accuracy
for the obtained expressions is determined from a comparison with exact results
available in ideal metal case. Computations of the thermal correction to both
the Casimir force and its gradient are performed in the framework of different
theoretical approaches proposed in the literature. The correction to the
Casimir force and its gradient due to lack of parallelism of the plate and
cylinder is determined using the nonmultiplicative approach. The error
introduced in the theory due to the finite length of the cylinder is estimated.
We propose that both static and dynamic experiments measuring the thermal
Casimir interaction between a cylinder and a plate using a micromachined
oscillator can shed additional light on the thermal Casimir force problem.
Specifically, it is shown that the static experiment is better adapted for the
measurement of thermal effects.Comment: 29 pages, 4 figures, 1 table; minor additions are made in accordance
to the version accepted for publication; to appear in Phys. Rev.
A Simple Theory of Condensation
A simple assumption of an emergence in gas of small atomic clusters
consisting of particles each, leads to a phase separation (first order
transition). It reveals itself by an emergence of ``forbidden'' density range
starting at a certain temperature. Defining this latter value as the critical
temperature predicts existence of an interval with anomalous heat capacity
behaviour . The value suggested in literature
yields the heat capacity exponent .Comment: 9 pages, 1 figur
The impact of climate change on the geographical distribution of two vectors of Chagas disease: Implications for the force of infection
Chagas disease, caused by the parasite Trypanosoma cruzi, is the most important vector-borne disease in Latin America. The vectors are insects belonging to the Triatominae (Hemiptera, Reduviidae), and are widely distributed in the Americas. Here, we assess the implications of climatic projections for 2050 on the geographical footprint of two of the main Chagas disease vectors: Rhodnius prolixus (tropical species) and Triatoma infestans (temperate species).We estimated the epidemiological implications of current to future transitions in the climatic niche in terms of changes in the force of infection (FOI) on the rural population of two countries: Venezuela (tropical) and Argentina (temperate). The climatic projections for 2050 showed heterogeneous impact on the climatic niches of both vector species, with a decreasing trend of suitability of areas that are currently at high-to-moderate transmission risk. Consequently, climatic projections affected differently the FOI for Chagas disease in Venezuela and Argentina. Despite the heterogeneous results, our main conclusions point out a decreasing trend in the number of new cases of Tr. cruzi human infections per year between current and future conditions using a climatic niche approach.Centro de Estudios Parasitológicos y de VectoresFacultad de Ciencias Naturales y Muse
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