611 research outputs found
Rank one discrete valuations of power series fields
In this paper we study the rank one discrete valuations of the field
whose center in k\lcor\X\rcor is the maximal ideal. In
sections 2 to 6 we give a construction of a system of parametric equations
describing such valuations. This amounts to finding a parameter and a field of
coefficients. We devote section 2 to finding an element of value 1, that is, a
parameter. The field of coefficients is the residue field of the valuation, and
it is given in section 5.
The constructions given in these sections are not effective in the general
case, because we need either to use the Zorn's lemma or to know explicitly a
section of the natural homomorphism R_v\to\d between the ring and
the residue field of the valuation .
However, as a consequence of this construction, in section 7, we prove that
k((\X)) can be embedded into a field L((\Y)), where is an algebraic
extension of and the {\em ``extended valuation'' is as close as possible to
the usual order function}
Memory effect in triglycine sulfate induced by a transverse electric field: specific heat measurement
The influence of a transverse electric field in the specific heat of
triglycine sulphate (TGS) has been studied. The specific heat of TGS has been
measured heating the sample from ferroelectric to paraelectric phase after
prolonged transverse electric field (i.e. perpendicular to the ferroelectric
axis). It is shown that the specific heat of TGS can remember the temperature
at which the transverse field was previously applied.Comment: ReVTeX4 Twocolumn 4 pages, 4 figure
Key polynomials for simple extensions of valued fields
Let be a simple transcendental extension
of valued fields, where is equipped with a valuation of rank 1. That
is, we assume given a rank 1 valuation of and its extension to
. Let denote the valuation ring of . The purpose
of this paper is to present a refined version of MacLane's theory of key
polynomials, similar to those considered by M. Vaqui\'e, and reminiscent of
related objects studied by Abhyankar and Moh (approximate roots) and T.C. Kuo.
Namely, we associate to a countable well ordered set the are called {\bf key
polynomials}. Key polynomials which have no immediate predecessor are
called {\bf limit key polynomials}. Let .
We give an explicit description of the limit key polynomials (which may be
viewed as a generalization of the Artin--Schreier polynomials). We also give an
upper bound on the order type of the set of key polynomials. Namely, we show
that if then the set of key polynomials has
order type at most , while in the case
this order type is bounded above by , where stands
for the first infinite ordinal.Comment: arXiv admin note: substantial text overlap with arXiv:math/060519
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Pushing the limits of concertedness. A waltz of wandering carbocations.
Among the array of complex terpene-forming carbocation cyclization/rearrangement reactions, the so-called "triple shift" reactions are among the most unexpected. Such reactions involve the asynchronous combination of three 1,n-shifts into a concerted process, e.g., a 1,2-alkyl shift followed by a 1,3-hydride shift followed by a second 1,2-alkyl shift. This type of reaction so far has been proposed to occur during the biosynthesis of diterpenes and the sidechains of sterols. Here we describe efforts to push the limits of concertedness in this type of carbocation reaction by designing, and characterizing with quantum chemical computations, systems that could couple additional 1,n-shift events to a triple shift leading, in principle to quadruple, pentuple, etc. shifts. While our designs did not lead to clear-cut examples of quadruple, etc. shifts, they did lead to reactions with surprisingly flat energy surfaces where more than five chemical events connect reactants and plausible products. Ab initio molecular dynamics simulations demonstrate that the formal minima on these surfaces interchange on short timescales, both with each other and with additional unexpected structures, allowing us a glimpse into a very complex manifold that allows ready access to great structural diversity
Experimental method to determine specific heat and transition enthalpy at a first order phase transition: fundamentals and application to a NiMnIn Heusler alloy
A new method that characterizes thermal properties during a first-order phase
transition is described. The technique consists in exciting the sample by a
series of constant frequency thermal pulses which one in every N pulses (N is a
small number like four) being exceedingly large in amplitude. This pulse
induces phase transformation which is inhibited during the following smaller
pulses due to thermal hysteresis. That way the specific heat for a given
mixture of phases can be determined. The results obtained are independent of
experimental parameters like the rate and the amplitude of the pulses, unlike
what happens in other calorimetric techniques. The method also provides the
enthalpy excess by analyzing the energy balance between the dissipated heat and
the heat flowing during each pulse of measurement.
The protocol is tested to analyze the phase transitions of a Heusler alloy Ni
50.54 Mn 33.65 In 15.82 . The paramagnetic-ferromagnetic transition for the
austenite phase is continuous and the specific heat shows a lambda anomaly. The
martensitic phase transition shows a first-order character and the specific
heat follows a step-like behaviour in contrast with previously reported
large-peak anomalies.Comment: 15 pages, 5 figure
El hastial sur de la catedral de León: patología existente derivada de la utilización de azufre en el retacado de grapas y tochos en las obras de restauración realizadas en el siglo XIX
During the restorations carried out in the nineteenth century in the cathedral of Leon, the architect-restorers Juan de Madrazo and Demetrio de los Rios proposed in their projects the use of liquid sulphur to caulk iron or bronze staples, or billets that linked edge elements and solids from the masonry. This solution, not previously used, has produced important construction pathology in the south gable today: cracks in a large number of blocks and partial detachment of them. Some of these detachments have been falling to the court of the temple with the risk to cause harm to people and things. It is worth to point out that this unpublished work has a great importance because, according to the content of the projects of both architects, this practice spread to more parts of the monument, so this localized pathology is expected to manifest itself in other areas with the consequent risk.Durante las restauraciones efectuadas en el siglo xix en la catedral de León, los arquitectos restauradores Juan de Madrazo y Demetrio de los Ríos propusieron en sus proyectos el empleo de azufre líquido para retacar los tochos y engrapados de hierro o bronce que enlazaban los elementos de remate y los sólidos de las fábricas. Esta solución, no utilizada con anterioridad, ha dado lugar a la aparición hoy en día de una importante patología en el hastial sur: la fractura de un gran número de sillares y el desprendimiento parcial de éstos, cayendo al atrio del templo con el consecuente peligro. Este trabajo es una contribución inédita que reviste gran importancia porque, según el contenido de los proyectos de ambos arquitectos, esta práctica se extendió a más partes del monumento, por lo que esta patología localizada es previsible que se manifieste en otras zonas del mismo con el consecuente riesgo
Mapping research on corporate misconduct in banking: lessons from literature on preventive and punitive actions
Advanced societies are increasingly concerned about corporate misconduct. Citizens are more willing to penalize it, and regulators are punishing companies more significantly than ever before. In particular, while reputation is a key asset for any business, corporate conduct has proven to be especially relevant in the banking industry. The present paper explores the main research efforts carried out on this topic, aiming to learn lessons from a comparison of studies focused on preventive and punitive actions. To accomplish this, we selected relevant corporate misconduct papers from the Web of Science, conducted a comprehensive bibliometric analysis to understand the role of banking industry-oriented research, and finally, performed a systematic review to distinguish between articles addressing impact measurement and those focusing on prevention. The results allowed us to respond to the unanswered questions regarding the particularities of the banking industry that make it require further and independent analysis and to the debate about whether the current regulation led to certain unwanted effects. Among those many lessons, one is strikingly important as most studies coincide in the conclusion that, instead of the current actions, more effort should be put into efficient prevention methods, such as education for more ethical corporate and individual behavior.The authors acknowledge the financial support the European Commission (20132-EPP- 1- 2020- 1- ES- EPP JMO-MODULE)
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