3,908 research outputs found
Relations between some analytic representations of one-loop scalar integrals
We compare several parametrized analytic expressions for an arbitrary
off-shell one-loop -point function in scalar field theory in -dimensional
space-time, and show their equivalence both directly and through path-integral
methods.Comment: 12 pages, NIKHEF-H/94-2
Ion milling - the perfect cross-section of a painted textile
The successful study and conservation of historical objects is greatly enhanced by accurate materials analysis. Here embedded cross-sections from a processional marching banner were viewed by scanning electron microscopy (SEM) pre and post ion milling The application of ion-milling to the resin embedded cross-sections of the painted textile improved the sample surface resulting in greatly enhanced SEM images by producing clear distinctions between layers. It also enabled clear images which show the areas where ingress of the ground paint layer had seeped into the textile support in some areas and not on others. This perhaps indicates deliberate differences in the preparation layer depending on the type of final painting layer or it could simply be due to a lack of accuracy in its application prior to painting. The analysis of cross-section samples from painted textiles often includes the textile itself making sample preparation more complex due to the possibility of fraying of the textile during sample polishing; the ion-milling technique prevented this from occurring. To enhance findings further analysis on these ion milled cross-section samples by the use of mapping spectroscopic techniques such as Fourier transform infrared spectroscopy (FTIR) and Raman would facilitate material identification of the layers
An Audit of the Use of Regional Anaesthesia for Caesarean Section in the Free State: from 2002 to 2004
Regional anaesthesia (RA) is associated with a lower mortality than general anaesthesia (GA) for obstetric anaesthesia. Accordingly, the Saving Mothers Report 1999-2001 proposed that 75% of Caesarean section (CS) should be performed under RA.2 An initial audit found that in the Free State, 71% of CS’s were performed under RA in 2002. Various educational interventions promoting the use of RA for CS were then instituted and the audit repeated for 2004, to determine whether there had been any change in the use of RA for CS’s from 2002 to 2004 and the 75% target achieved
Economic Reform & Integration Project (ERI) of the Technology, Economy & Society (TES) Program
In summer 1989 IIASA was approached by Academician S. Shatalin of the Soviet Union with the request to consider establishing an activity that could analyze international economic interdependencies and serve as a scientific forum to support economic reforms in the Soviet Union and the other socialist Member countries of our Institute. In late 1989, the Economic Reform and Integration (ERI) Project was established with the general aim of establishing bridges between eastern and western economic theory and practice, creating conditions for mutually assimilating successful managerial experience, and for possible rapprochement of economic systems.
This paper presents the current status of the IIASA ERI Project
The XML benchmark project
With standardization efforts of a query language for XML documents drawing to a close, researchers and users increasingly focus their attention on the database technology that has to deliver on the new challenges that the sheer amount of XML documents produced by applications pose to data management: validation, performance evaluation and optimization of XML query processors are the upcoming issues. Following a long tradition in database research, the XML Store Benchmark Project provides a framework to assess an XML database's abilities to cope with a broad spectrum of different queries, typically posed in real-world application scenarios. The benchmark is intended to help both implementors and users to compare XML databases independent of their own, specific application scenario. To this end, the benchmark offers a set queries each of which is intended to challenge a particular primitive of the query processor or storage engine. The overall workload we propose consists of a scalable document database and a concise, yet comprehensive set of queries, which covers the major aspects of query processing. The queries' challenges range from stressing the textual character of the document to data analysis queries, but include also typical ad-hoc queries. We complement our research with results obtained from running the benchmark on our XML database platform. They are intended to give a first baseline, illustrating the state of the art
Caloric Curves in two and three-dimensional Lennard-Jones-like systems including Long-range forces
We present a systematic study of the thermodynamics of two and
three-dimensional generalized Lennard-Jones () systems focusing on the
relationship between the range of the potential, the system density and its
dimension. We found that the existence of negative specific heats depends on
these three factors and not only on the potential range and the density of the
system as stated in recent contributions.Comment: LaTex, 12 pages, 7 figure
Photon Splitting in a Strong Magnetic Field: Recalculation and Comparison With Previous Calculations
We recalculate the amplitude for photon splitting in a strong magnetic field
below the pair production threshold, using the worldline path integral variant
of the Bern--Kosower formalism. Numerical comparison (using programs that we
have made available for public access on the Internet) shows that the results
of the recalculation are identical to the earlier calculations of Adler and
later of Stoneham, and to the recent recalculation by Baier, Milstein, and
Shaisultanov.Comment: Revtex, 9 pages, no figure
Lepton asymmetry and the cosmic QCD transition
We study the influence of lepton asymmetry on the evolution of the early
Universe. The lepton asymmetry is poorly constrained by observations and
might be orders of magnitude larger than the baryon asymmetry , . We find that lepton asymmetries that are large compared to the
tiny baryon asymmetry, can influence the dynamics of the QCD phase transition
significantly. The cosmic trajectory in the phase diagram of strongly
interacting matter becomes a function of lepton (flavour) asymmetry. Large
lepton asymmetry could lead to a cosmic QCD phase transition of first order.Comment: 23 pages, 14 figures; matches published version, including Erratum.
Conclusions, pictures, numerics remained unchange
The flat phase of fixed-connectivity membranes
The statistical mechanics of flexible two-dimensional surfaces (membranes)
appears in a wide variety of physical settings. In this talk we discuss the
simplest case of fixed-connectivity surfaces. We first review the current
theoretical understanding of the remarkable flat phase of such membranes. We
then summarize the results of a recent large scale Monte Carlo simulation of
the simplest conceivable discrete realization of this system \cite{BCFTA}. We
verify the existence of long-range order, determine the associated critical
exponents of the flat phase and compare the results to the predictions of
various theoretical models.Comment: 7 pages, 5 figures, 3 tables. LaTeX w/epscrc2.sty, combined
contribution of M. Falcioni and M. Bowick to LATTICE96(gravity), to appear in
Nucl. Phys. B (proc. suppl.
The Phase Diagram of Crystalline Surfaces
We report the status of a high-statistics Monte Carlo simulation of
non-self-avoiding crystalline surfaces with extrinsic curvature on lattices of
size up to nodes. We impose free boundary conditions. The free energy
is a gaussian spring tethering potential together with a normal-normal bending
energy. Particular emphasis is given to the behavior of the model in the cold
phase where we measure the decay of the normal-normal correlation function.Comment: 9 pages latex (epsf), 4 EPS figures, uuencoded and compressed.
Contribution to Lattice '9
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