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Phase separation has become a fascinating subject in the discussion
of cuprate superconductors. All these materials have layered
structures containing CU02 planes as the most important building
blocks. They are coupled only weakly so that the electronic
properties show a nearly two-dimensional behaviour. Due to
correlations the undoped compounds are insulators of the Mott
Hubbard type exhibiting long-range antiferromagnetic order. Upon
doping a rich scenario of physical phenomena appears: Even at low
hole concentra tions the antiferromagnetic ordering temperature is
reduced drastically and spin-glass behaviour as well as a hopping
type conductivity can be observed. Further doping leads to
metallic-like conductivity and below Tc to super conductivity. In
this doping regime antiferromagnetic fluctuations are still
observed. At very high charge carrier densities superconductivity
is lost and the systems show pure metallic conduction without
,magnetic correlations. One of the most interesting phenomena in
high-T c research is the interplay between magnetism and
conductivity or superconductivity. Especially the behaviour of
charge carriers in the antiferromagnetic background raises a number
of open questions. Two scenarios become possible: the carriers tend
to delocalize over the whole crystal forming a homogeneous state
with band-like structure or they separate into hole-rich
(conducting, superconducting) and hole-poor (insulating,
antiferromagnetic) phases leading to an inhomogeneous structure.
Structural Phase Transitions II, like its predecessor (Topics in
Current Physics, Vol. 23), presents selected methods and recent
advances in the experimental investigation of phase transitions in
solids. The two chapters in this volume deal with electron
paramagnetic resonance (EPR), and with nuclear magnetic and nuclear
quadrupole resonance (NMR-NQR). Both techniques are particularly
sensitive to local properties. The chapter on EPR concentrates
largely on the investigation of static properties, including
mean-field behaviour, critical and multicritical phenomena, whilst
NMR is shown to be a powerful tool for studying nonlinear dynamics,
incommensurate transitions, and disordered systems. This book will
serve as an excellent introduction to the methodology and
applications of EPR and NMR-NQR for all those wishing to become
acquainted with these important tools for studying structural phase
transitions.
This volume contains the lectures of "Earlier and Recent Aspects of
Super conductivity," the 18th course of the International School of
Materials Science and Technology, which was held at the Ettore
Majorana Centre for Scientific Culture in Erice (Sicily), Italy,
July 4-16, 1989. In the wake of the discovery of high-Tc oxides
many international confer ences have been held on the subject,
mainly intended for those already working in high-Tc research.
Hence, the idea evolved of organizing a school dedicated to
students and young scientists entering the field of
superconductivity. The intention was to give a broad perspective of
the field with its eight decades of research history and thus to
link existing fields of knowledge and gain con tinuity. The new
high-Tc cuprates were integrated, both historically and by subject,
into the field of classical superconductivity, as well as into its
newer branches of heavy-fermion, organic and chalcogenide
superconductors. Even the organizers and the lecturers were
surprised how many cross-links became apparent between the
different branches of superconductivity. The lectures have been
grouped into four parts, namely: - Fundamental properties of
superconductors - Coherence-length-related properties - Electronic
and magnetic properties - Theoretical models The number of
applications from potential participants greatly exceeded the
capacity of the facilities available. Ultimately, 100 students from
25 coun tries were selected to attend the course. The remarkable
surroundings of the medieval town of Erice promoted a most
stimulating but nevertheless relaxed atmosphere."
What did the inventor of Hershey's syrup have to do with the
founding of a major medical school? Where did Ben and Jerry learn
to make ice cream? What accomplishment is Joe Paterno most proud
of? The ABC's of PSU has the answers. Whether you are an alumnus or
fan, this book has plenty to offer. Each letter focuses on a topic
of interest. The accompanying images show some rare views of this
land grant university.
As software systems grow older, their maintenance costs increase
and reengineering often becomes necessary to keep a system valuable
and to enable its further evolution. Object-oriented software
systems are relatively young, yet the need to reengineer them
arises. The Object-oriented programming paradigm implies a
different approach to reengineering as for programs written in a
procedural language. This book presents a methodology on how to
tackle object-oriented software reengineering in practice. Adequate
techniques and tools are introduced within an organizational
framework and applied to real world ticket sales client written in
Java. Based on the results of the system analysis, options on how
to proceed are discussed and a plan for the restructuring of the
system is presented. This book is of use for IT professionals who
need a overview and hands on knowledge about object-oriented
sofware reengineering. It is also a valuable case study for
eduactional purposes since it shows how various theoretical
reengineering aspects are applied in practice.
An X Fairy is any mystical creature who, commits a terrible crime,
most often, murder. The punishment for such a terrible creature is
exile. That is what it's strange when a good, polite Elf named
Dekon becomes one. Even though the reason he killed was to save his
mother from a Goblin. Never the less, he is banned from his
peaceful home of Elfia. He is sent out into a new world. With no
where else to go, he follows a mysterious map to the dangerous
empire capital of the Goblins. Even he is not sure what awaits him
there.
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