611 research outputs found

    Rank one discrete valuations of power series fields

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    In this paper we study the rank one discrete valuations of the field k((X1,...,Xn))k((X_1,..., X_n)) 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 σ\sigma of the natural homomorphism R_v\to\d between the ring and the residue field of the valuation vv. However, as a consequence of this construction, in section 7, we prove that k((\X)) can be embedded into a field L((\Y)), where LL is an algebraic extension of kk 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

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    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 TsT_s at which the transverse field was previously applied.Comment: ReVTeX4 Twocolumn 4 pages, 4 figure

    Key polynomials for simple extensions of valued fields

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    Let ι:KLK(x)\iota:K\hookrightarrow L\cong K(x) be a simple transcendental extension of valued fields, where KK is equipped with a valuation ν\nu of rank 1. That is, we assume given a rank 1 valuation ν\nu of KK and its extension ν\nu' to LL. Let (Rν,Mν,kν)(R_\nu,M_\nu,k_\nu) denote the valuation ring of ν\nu. 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 ι\iota a countable well ordered set Q={Qi}iΛK[x]; \mathbf{Q}=\{Q_i\}_{i\in\Lambda}\subset K[x]; the QiQ_i are called {\bf key polynomials}. Key polynomials QiQ_i which have no immediate predecessor are called {\bf limit key polynomials}. Let βi=ν(Qi)\beta_i=\nu'(Q_i). 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 char kν=0\operatorname{char}\ k_\nu=0 then the set of key polynomials has order type at most ω\omega, while in the case char kν=p>0\operatorname{char}\ k_\nu=p>0 this order type is bounded above by ω×ω\omega\times\omega, where ω\omega stands for the first infinite ordinal.Comment: arXiv admin note: substantial text overlap with arXiv:math/060519

    Experimental method to determine specific heat and transition enthalpy at a first order phase transition: fundamentals and application to a NiMnIn Heusler alloy

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    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

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    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

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    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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