Reducing the thermal inhomogeneity of massive steel slabs in continuous furnaces

A method is proposed for selecting the best displacement parameters for supporting pipes. The influence of lateral displacement of the longitudinal guide pipes in continuous furnaces on the disappearance of the dark spot is studied. © 2013 Allerton Press, Inc

Destruction of the Dendritic Bridge in Soft Reduction of Continuous-Cast Slab

In order to improve the properties of structural steels, the crystalline structure and chemical composition of the continuous-cast billet must be more isotropic. A promising approach is soft reduction of the billet by a special (dynamic) section in the roller track of the continuous-casting machine Industrial tests of soft reduction in the continuous casting of steel slabs on a vertical machine at OAO Severstal were described in Soft reduction increased the proportion of melts with an axial chemical-inhomogeneity score no greater than 1 from 68.9 to 95.8%, according to At the International Conference on Continuous Steel Casting (Madrid, 1987), the use of soft reduction in continuous casting of round and square bar billet was reported Soft reduction reduced the axial porosity of the cast billet by a factor of around 1.5-3, according to Two main factors are responsible for the axial chemical inhomogeneity in continuous-cast slabs, according to 2) swelling of the shell of the solidifying billet due to the ferrostatic pressure of the melt in the nonsolidifying part, with a sufficiently large distance between the supporting rollers. We now consider the theoretical principles underlying the reduction in axial chemical inhomogeneity of continuous-cast slabs by soft reduction, taking account of both the factors noted in We begin with the assumption that the reduced axial inhomogeneity in the billet is due to destruction of the dendritic bridges that are formed by the growing crystals (columnar or equiaxial crystals) and hinder the melt's access to the shrinkage zones in the central part of the solidifying billets. This is not an original suggestion. Under the influence of soft reduction, "the core is strengthened, the liquational material is driven out, and the dendrites are broken down, with improvement in axial structure of the ingot," according to In the present work, we attempt quantitative estimation of the probability that the bridges preventing melt access to the shrinkage cavities (pores) in the axial zone of the billet will disintegrate under the action of soft reduction. In production tests, it is found that soft reduction is most effective when the liquid-phase content S within the two-phase zone of the solidifying billet is 20-80%. When the content of solid phase Ψ = 1 -S is below the lower limit Ψ 1 = 0.2, the solidifying metal in the twophase zone consists of a suspension of crystals in melt, and the application of external forces leads to motion of the suspension as a whole within the liquid core (the nonsolidifying part of the billet), without significant improvement in the cast structure. On reaching the critical quantity of solid phase Ψ cr = 0.2, the crystals suspended in the melt, together with the oriented (columnar) dendrites, form a dendritic skeleton (filled with melt) capable of resisting the applied external force. The application of compressive force to the shell of the cast billet by the supporting rollers may fracture the dendritic skeleton; this does not always improve the cast structure. Evidently, when the solid-phase content in the two-phase zone exceeds the upper limit Ψ 2 = 0.8, the resistance of the dendritic skeleton to the externa

OpenEMR – Historia clínica electrónica de código abierto y distribución gratuita, apta para su uso en el sistema de salud de Argentina

Elegir un software para Historia Clínicas Electrónica (HCE) es una decisión compleja y generadora de un compromiso duradero. Un software único para el sistema hospitalario generaría una masa crítica de usuarios que garantizaría la calidad, el soporte y la innovación. Los productos gratuitos de Código Abierto son deseables por sus múltiples ventajas, y brindan mayor libertad y garantías a sus usuarios. El producto OpenEMR presenta la mayor cantidad de usuarios y desarrolladores activos, y se propone como estándar y como candidato para su adopción generalizada.Sociedad Argentina de Informática e Investigación Operativ

Qué clase de judío soy

Una vez, un joven dirigente de una asociación comunitaria, me preguntó: “¿Qué clase de judío sos vos? No distinguís Kippur de Rosh Hashaná, no crees en Dios, no celebrás la llegada del sábado... ni siquiera sabés idish...” Apenas atiné a contestarle que estoy circunciso, lo cuál no sé si le habrá bastado. Evidentemente, de las señales de pertenencia que enumeró, la de mínima era, a su entender, saber idish. Lo cierto es que me gustaría: me parece un idioma lleno de energía, adivino que es tan..

Theoretical basis for an economic evaluation of road accident losses

The article regards the theoretical basis for estimating life value for the purpose of calculating road accident losses. The paper presents a simple structure of accident costs that could be taken into account in order to calculate the total economic value of road accidents. The article also shows the basic methods of estimating life value in different countries for different purposes and describes the problems of estimating life value in the Republic of Belarus. The paper comprises practically used values of life and the costs of injuries in some countries. Losses and costs caused by a road accident are regarded as direct and indirect. Besides, losses occurring during a road accident are considered as economic and social. The temporary estimated values of the total economic value of road accidents are discussed at the end of the article. First published online: 27 Oct 201

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Screening and inplane magnetoresistance of anisotropic two-dimensional gas

In order to split the influence of the orbital and spin effects on the inplane magnetoresistance of a quasi two-dimensional gas we derive its linear response function and dielectric function for the case of anisotropic effective mass. This result is used for the calculation of elastic transport relaxation time of a quasi two dimensional system in a parallel magnetic field. The relaxation time is proved to be isotropic in the low density limit for the case of charged impurity scattering, allowing to separate the two contributions.Comment: as published. 4 pages, 1 figur

ОПРЕДЕЛЕНИЕ ДЛИНЫ ОСТАНОВОЧНОГО ПУНКТА В ЗАВИСИМОСТИ ОТ ИНТЕРВАЛА ДВИЖЕНИЯ МАРШРУТНЫХ ПАССАЖИРСКИХ ТРАНСПОРТНЫХ СРЕДСТВ

The paper considers a probability of simultaneous arrival more than one route vehicle at a stopping point  depending on a traffic interval.  Probability dependences of arrival more than one route vehicle on a traffic interval have been determined in the paper. The paper proposes calculated lengths of route vehicles, a methodology for calculation of stopping point length. A calculation example is given in the paper.Исследуется вероятность прибытия на остановочный пункт более одного маршрутного пассажирского транспортного средства (МПТС) одновременно в зависимости от интервала движения, определены зависимости вероятности прибытия более одного МПТС от интервала движения, предложены расчетные длины МПТС, методика расчета длины остановочного пункта, приведен пример расчета

RADIATION KINETICS AND CHEMICAL REACTIVITY OF BARRIER DISCHARGES IN HUMID ARGON

International audienceThe technique of spatially resolved cross-correlation spectroscopy was used to record two-dimensional luminosity distributions for the selected spectral bands of molecular nitrogen (λ=337.1 nm), OH-radical (λ=308 nm), and two spectral lines of excited Ar (λ=750.4 nm and λ=763.5 nm) emitted by the microdischarges of the barrier discharge in flowing humid argon at atmospheric pressure. Concentrations of two stable reaction products of H2O decomposition (H2 and O2) in argon plasma were determined experimentally as functions of humidity. Comparison of these results with the corresponding measurements of radiation kinetics permitted a detailed analysis of the influence of the discharge mechanism on its chemical reactivity in humid argon to be accomplished