6,447 research outputs found
The Classification of -Modules with Partial Decomposition Bases in
Ulm's Theorem presents invariants that classify countable abelian torsion
groups up to isomorphism. Barwise and Eklof extended this result to the
classification of arbitrary abelian torsion groups up to -equivalence. In this paper, we extend this classification to a class
of mixed -modules which includes all Warfield modules and is
closed under -equivalence. The defining property of these
modules is the existence of what we call a partial decomposition basis, a
generalization of the concept of decomposition basis. We prove a complete
classification theorem in using invariants deduced from the
classical Ulm and Warfield invariants
Influence of surface-related strain and electric field on acceptor wave functions in Zincblende semiconductors
The spatial distribution of the local density of states (LDOS) at Mn
acceptors near the (110) surface of p-doped InAs is investigated by Scanning
Tunneling Microscopy (STM). The shapes of the acceptor contrasts for different
dopant depths under the surface are analyzed. Acceptors located within the
first ten subsurface layers of the semiconductor show a lower symmetry than
expected from theoretical predictions of the bulk acceptor wave function. They
exhibit a (001) mirror asymmetry. The degree of asymmetry depends on the
acceptor atoms' depths. The measured contrasts for acceptors buried below the
10th subsurface layer closely match the theoretically derived shape. Two
effects are able to explain the symmetry reduction: the strain field of the
surface relaxation and the tip-induced electric field.Comment: 8 pages, 4 figure
Anomalously large capacitance of an ionic liquid described by the restricted primitive model
We use Monte Carlo simulations to examine the simplest model of an ionic
liquid, called the restricted primitive model, at a metal surface. We find that
at moderately low temperatures the capacitance of the metal/ionic liquid
interface is so large that the effective thickness of the electrostatic
double-layer is up to 3 times smaller than the ion radius. To interpret these
results we suggest an approach which is based on the interaction between
discrete ions and their image charges in the metal surface and which therefore
goes beyond the mean-field approximation. When a voltage is applied across the
interface, the strong image attraction causes counterions to condense onto the
metal surface to form compact ion-image dipoles. These dipoles repel each other
to form a correlated liquid. When the surface density of these dipoles is low,
the insertion of an additional dipole does not require much energy. This leads
to a large capacitance that decreases monotonically with voltage ,
producing a "bell-shaped" curve . We also consider what happens when the
electrode is made from a semi-metal rather than a perfect metal. In this case,
the finite screening radius of the electrode shifts the reflection plane for
image charges to the interior of the electrode and we arrive at a
"camel-shaped" . These predictions seem to be in qualitative agreement
with experiment.Comment: 7 pages, 5 figures; some numerical comparisons added; schematic
figure added, additional discussion of effect of electrode material, section
added with comparison to semiconductor devices; plotting error fixed in Fig.
The emergence of classical behavior in magnetic adatoms
A wide class of nanomagnets shows striking quantum behavior, known as quantum
spin tunneling (QST): instead of two degenerate ground states with opposite
magnetizations, a bonding-antibonding pair forms, resulting in a splitting of
the ground state doublet with wave functions linear combination of two
classically opposite magnetic states, leading to the quenching of their
magnetic moment. Here we study how QST is destroyed and classical behavior
emerges in the case of magnetic adatoms, as the strength of their coupling,
either to the substrate or to each other, is increased. Both spin-substrate and
spin-spin coupling renormalize the QST splitting to zero allowing the
environmental decoherence to eliminate superpositions between classical states,
leading to the emergence of spontaneous magnetization.Comment: 5 pages, 4 figure
Courts in quest for legitimacy; the case of wrongful life
This discussion will consider how different courts deal with difficult cases, and how courts
seek to maintain the legitimacy of their judicial authority. How do courts search for
legitimacy? From what sources do they draw their legitimacy? As a central example I will
use the problem often referred to as the “wrongful life” cases: can a medical care provider be
held liable for negligent malpractice that results in the creation or preservation of a life that is
not considered worth living? This question touches upon the autonomy of the plaintiff. By
comparing three judicial decisions in “wrongful life” cases from courts from the United
States, France and the Netherlands I hope to illustrate different possible sources of judicial
legitimacy
Limits of Private Law
In 2005 the Dutch Supreme Court decided a wrongful life case.2 This
case concerned a woman who consulted her midwife during her pregnancy
because there had been two cases of handicaps in her husband’s
family, due to chromosomal disorder. The midwife did not think it necessary
to investigate the matter any further. This was later considered a professional
failure with dramatic effects. When born, baby Kelly turned out
to have serious mental and physical handicaps from which she suffered
severely. The parents claimed damage – both on their own accord and in
Kelly’s name – and their claims were sustained by both the court of
appeal and the Supreme Court. The Supreme Court not only considered
the strictly legal issues but also considered moral and pragmatic arguments
that had been put forward against such so-called ‘wrongful life
claims’. Firstly, there is the moral opposition that sustaining these claims
violates the principle regarding the dignity of human life, since it acknowledges
that not being born is preferable to living in a condition like
hers. Secondly, there is the pragmatic argument that sustaining claims
like this will tempt doctors to practice ‘defensive medicine’ to avoid
serious risk. Both arguments were carefully examined by the court and
subsequently rejected. What does the Supreme Court in fact do here?
Does it call out or explain the law to us? Or does it exceed its limits by elaborating
on principles and policies, taking into account the moral
grounds and the possible consequences of the ruling itself? In both
directions the question arises: what constitutes the limits of private law
Ein deutscher Europäer : mit europäischer Politik kam Walter Hallstein zum ersten Mal im Frühjahr 1948 in Kontakt ...
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