57,644 research outputs found
A psychoanalytic concept illustrated: Will, must, may, can — revisiting the survival function of primitive omnipotence
The author explores the linear thread connecting the theory of Freud and Klein, in terms of the central significance of the duality of the life and death instinct and the capacity of the ego to tolerate contact with internal and external reality. Theoretical questions raised by later authors, informed by clinical work with children who have suffered deprivation and trauma in infancy, are then considered. Theoretical ideas are illustrated with reference to observational material of a little boy who suffered deprivation and trauma in infancy. He was first observed in the middle of his first year of life while he was living in foster care, and then later at the age of two years and three months, when he had been living with his adoptive parents for more than a year
IMPACTS OF GLOBAL WARMING ON CROPPING PRACTICES IN ALBERTA
A Target MOTAD farm-level model was developed to assess the expected impacts from global warming on representative grain and oilseed farms in Alberta. It was found that a warmer climate would increase crop yields and length of the cropping season. Net returns and shadow values of land would increase substantially. Price risk generally was more important than yield risk under simulated warmer climates.Environmental Economics and Policy,
Research and development of magnesium/aluminum electroforming process for solar concentrators Final report, 13 May 1966 - 10 May 1967
Magnesium and aluminum electroforming process for solar concentrator
Large-Scale Radio Structure in the Universe: Giant Radio Galaxies
Giant radio galaxies (GRGs), with linear sizes larger than 1 Mpc (H0=50
km/s/Mpc), represent the biggest single objects in the Universe. GRGs are rare
among the entire population of radio galaxies (RGs) and their physical
evolution is not well understood though for many years they have been of
special interest for several reasons. The lobes of radio sources can compress
cold gas clumps and trigger star or even dwarf galaxy formation, they can also
transport gas from a host galaxy to large distances and seed the IGM with
magnetic fields. Since GRGs have about 10 to 100 times larger sizes than normal
RGs, their influence on the ambient medium is correspondingly wider and is
pronounced on scales comparable to those of clusters of galaxies or larger.
Therefore `giants' could play an important role in the process of large-scale
structure formation in the Universe. Recently, thanks to the new all sky radio
surveys, significant progress in searching for new GRGs has been made.Comment: To appear in Multiwavelength AGN Surveys, ed. R. Maiolino and R.
Mujica, Singapore: World Scientific, 2004, 2 page
A study of starting time in great hard X-ray flares
An analysis of the starting time in ten great hard X-ray bursts observed with the X-Ray Burst Spectrometer (HXRBS) is presented. It is shown that the impulsive phase of nine of them is composed of a preflash phase, during which the burst is observed up to an energy limit ranging from some tens of keV to 200 keV, followed ten to some tens of seconds afterwards by a flash phase, where the count rate rises simultaneously in all detector channels. For two events strong gamma-ray line emission is observed and is shown to start close to the onset of the flash phase
Studies on the flight medical aspects of the German Lufthansa non-stop route from Frankfurt to Rio de Janeiro, part 1
The problem of crew size for regularly scheduled flights between Frankfurt and Rio de Janeiro is discussed. Factors affecting crew performance are examined, comparisons are drawn to regulations of other countries and crew questionnaires and tests are presented
Evolution of Magnetic and Superconducting Fluctuations with Doping of High-Tc Superconductors
Electronic Raman scattering from high- and low-energy excitations was studied
as a function of temperature, extent of hole doping, and energy of the incident
photons in Bi_2Sr_2CaCu_2O_{8 \pm \delta} superconductors. For underdoped
superconductors, short range antiferromagnetic (AF) correlations were found to
persist with hole doping, and doped single holes were found to be incoherent in
the AF environment. Above the superconducting (SC) transition temperature T_c,
the system exhibits a sharp Raman resonance of B_{1g} symmetry and energy of 75
meV and a pseudogap for electron-hole excitations below 75 meV, a manifestation
of a partially coherent state forming from doped incoherent quasi particles.
The occupancy of the coherent state increases with cooling until phase ordering
at T_c produces a global SC state.Comment: 6 pages, 4 color figures, PDF forma
Estimating single molecule conductance from spontaneous evolution of a molecular contact
We present an original method to estimate the conductivity of a single
molecule anchored to nanometric-sized metallic electrodes, using a Mechanically
Controlled Break Junction (MCBJ) operated at room temperature in liquid. We
record the conductance through the metal / molecules / metal nanocontact while
keeping the metallic electrodes at a fixed distance. Taking advantage of
thermal diffusion and electromigration, we let the contact naturally explore
the more stable configurations around a chosen conductance value. The
conductance of a single molecule is estimated from a statistical analysis of
raw conductance and conductance standard deviation data for molecular contacts
containing up to 14 molecules. The single molecule conductance values are
interpreted as time-averaged conductance of an ensemble of conformers at
thermal equilibrium.Comment: 25 pages, 6 figure
Multi-Frequency Study of the B3-VLA Sample II. The Database
We present total flux densities of 1049 radio sources in the frequency range
from 151 MHz to 10.6 GHz. These sources belong to the B3-VLA sample, which is
complete down to 100 mJy at 408 MHz. The data constitute a homogeneous spectral
database for a large sample of radio sources, 50 times fainter than the 3C
catalogue, and will be used to perform a spectral ageing analysis, which is one
of the critical points in understanding the physics and evolution of
extragalactic radio sources.Comment: 14 pages, 3 figures, accepted for publication in Astronomy &
Astrophysics Supplement Series, gzipped postscript file also available at
http://multivac.jb.man.ac.uk:8000/ceres/papers/papers.html or
http://gladia.astro.rug.nl:8000/ceres/papers/papers.htm
Validity of the Taylor Hypothesis for Linear Kinetic Waves in the Weakly Collisional Solar Wind
The interpretation of single-point spacecraft measurements of solar wind
turbulence is complicated by the fact that the measurements are made in a frame
of reference in relative motion with respect to the turbulent plasma. The
Taylor hypothesis---that temporal fluctuations measured by a stationary probe
in a rapidly flowing fluid are dominated by the advection of spatial structures
in the fluid rest frame---is often assumed to simplify the analysis. But
measurements of turbulence in upcoming missions, such as Solar Probe Plus,
threaten to violate the Taylor hypothesis, either due to slow flow of the
plasma with respect to the spacecraft or to the dispersive nature of the plasma
fluctuations at small scales. Assuming that the frequency of the turbulent
fluctuations is characterized by the frequency of the linear waves supported by
the plasma, we evaluate the validity of the Taylor hypothesis for the linear
kinetic wave modes in the weakly collisional solar wind. The analysis predicts
that a dissipation range of solar wind turbulence supported by whistler waves
is likely to violate the Taylor hypothesis, while one supported by kinetic
Alfven waves is not.Comment: 10 pages, 3 figures, Accepted for publication in The Astrophysical
Journa
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