On numerical simulation of the continuous casting process

1988

In this paper a steady-state nonlinear parabolic-type model, which simulates the multiphase heat transfer during solidification in continuous casting, is presented. An enthalpy formulation is used and we apply a FE-method in space and an implicit Euler method in time. A detailed solution algorithm is presented. We compute the temperature distributions in the strand when the boundary conditions (mold/spray cooling) on the strand surface are known. The numerical model gives thereby a good basis for the testing of new designs of continuous-casting machines. An application of the model to continuous casting of billets is presented.

Antimykotische Wirkstoffe, Mitt. Chlor-(1-piperazinyl)-1,3,5-triazine

1988

Aus der Umsetzung von Cyanurchlorid (1) mit den Piperazinderivaten 2a–c bei –20 bis 10° gehen die Dichlor-(1-piperazinyl)-1,3,5-triazine 3a–c hervor. Bei der erhohten Reaktionstemperatur von 40° erfolgt aus 1 und den Piperazinderivaten 4a–b Bildung der 2-Chlor-4,6-bis(piperazinyl)-1,3,5-triazine 5a–b. Zu gemischt substituierten Chlor-1,3,5-triazinen 9 fuhrt die nacheinander erfolgende Umsetzung von 1 mit 2 verschiedenen cyclischen sekundaren Aminen (6 und 8). Die Strukturtypen 3, 5 und 9 zeigen in den 1H-NMR-Spektren zwei fur Piperazinringe charakteristische Signalgruppen im Bereich 2.4–4.0 ppm. Unter den neu entwickelten Verbindungen finden sich Vertreter mit sehr starker antimykotischer W…

Killer toxin producing strains of the yeasts Hanseniaspora uvarum and Pichia kluyveri

1988

By heat treatment killer strains of the type K1 of Saccharomyces cerevisiae that are known to harbour dsRNA plasmids were completely cured, whereas only a small fraction of the clones of the killer type K2 had lost the dsRNA dependent killer character. The K2 killers but not the strains of killer type K1 were easily cured by cycloheximide. Killer strains of Hanseniaspora uvarum were not curable by heat treatment. Curing was successfull with cycloheximide or 5-fluorouracil. Two double-stranded RNA plasmids were detected in the killer strains of H. uvarum. The smaller dsRNA plasmid was absent in the strains that were cured of their killer character by 5-fluorouracil. The killer character of H…

The Obstacle Problem in a Non-Linear Potential Theory

1988

M. Brelot gave rise to the concept harmonic space when he extended classical potential theory on ℝn to an axiomatic system on a locally compact space. I have recently constructed1 a non-linear harmonic space by dropping the assumption that the sum of two harmonic functions is harmonic and considering some other axioms instead. This approach has its origin in the work of O. Martio, P. Lindqvist and S. Granlund2,3,4, who have developed a non-linear potential theory on ℝn connected with variational integrals of the type ∫ F(x,∇u(x)) dm(x), where F(x, h) ≈ |h|p.

New Results on Multiphoton Free-Free Transitions

1988

Recently some of the present authors have reported on calculations concerning free-free transitions in the presence of very strong laser fields,1 in which a number of peculiar features were clearly displayed (among others, well pronounced maxima in the total cross sections and an oscillatory structure). In particular, those calculations concerned total cross sections of direct and inverse multiphoton bremsstrahlung, for several numbers of exchanged photons as functions of the field intensity. Figs. 1 and 2 show a sample of the typical results reported in Ref. 1.

Intertextualidad y cultura de masas: entre la parodia y el pastiche

1988

La parodia ha afectado al género de la Universal Pictures en The Munsters, telefilm de los años sesenta, del mismo modo como el pastiche alcanzó a Vertigo en el caso de Falcon Crest. Pero en realidad ¿nos basta el término parodia para dar cuenta de esta actitud en la que, sin duda, reconocemos algo del pastiche antes estudiado? Cabe, a pesar de todo, suponer que la distinción no ha de ser tan tajante como la formulamos en este texto, que las fronteras no son tan nítidas y que, en todo caso, ni en un ejemplo ni en otro hay integrac¡ón en la estructura. Detengamos aquí nuestro texto y limitémonos a anunciar una segunda entrega en la que se apliquen los criterios que aquí funcionan a la cita r…

Der intramedulläre Druck während Marknagelosteosynthesen

1988

In einer Sammelstudie der AO fand ECKE (1) 1 985 bei 1 257 Marknagelosteosynthesen wegen isolierter Femurfraktur in 4% der Falle schwere pulmonale Komplikationen wie Fettembolie, Lungenversagen und Pneumonien. Die pulmonale Komplikationsrate war bei den unter dreisigjahrigen primar operierten Patienten ebenfalls 4%, so das altersbedingte Risikofaktoren als alleinige Ursache ausscheiden.

Ein Expertensystem mit integrierter Simulationskomponente am Beispiel des Tennis-Simulations-Systems TESSY

1988

Das TESSY-Expertensystem organisiert Spiel- bzw. Leistungsdaten von Tennisspielern in einer Datenbank, wertet sie aus, simuliert Spiele zur interaktiven Nutzung auf dem Bildschirm und simuliert Spiele fur die interne Gewinnung zusatzlicher Daten und Fakten.

Preparation of N,O-Aminals as Synthetic Equivalents of H2C=NAr and (H2C=NHAr)+ Ions: Neutral and Acid-promoted Transformations

1988

A general method for the synthesis of N,O-aminals derived from primary aromatic amines is described. The reactivity of these compounds under neutral and acidic conditions has been studied and the title compounds can be envisaged as general purpose H2C=NAr or (H2C=NHAr)+ equivalents. N,O-Aminals have been converted into perhydrotriazines by moderate heating and into bis(4-aminoaryl) methane derivatives or N-benzylarylamines, respectively when heated in acidic media with pH control. Reduction of N, O-acetals with sodium cyanoborohydride has revealed that the C-O bond is broken exclusively in acidic media.

Esencialismo y experimentación en la filosofía natural de John Locke

1988

Esencialismo y experimentación en la filosofía natural de John Locke

Valores Humanos. Principales concepciones teóricas.

1988

Valores Humanos. Principales concepciones teóricas.

L'impact de la crise économique sur les systèmes éducatifs

1988

International audience

Glyphosate: herbicidal effects, mode of action and degradation in soil

1988

Éducation, formation et choix technologiques : un modèle macro économique sur le cas de l'Équateur

1988

International audience

Postersitzung 6: Extrakorporale Stoßwellenlithotripsie (ESWL) bei komplizierter Urolithiasis

1988

Die Nierensteinbehandlung hat sich mit Einfuhrung von PCNL und ESWL innerhalb weniger Jahre dramatisch gewandelt. Die Kombination von PCNL plus ESWL minimiert die Nachteile beider Techniken, die sie in ihrer alleinigen Anwendung bei der Behandlung von Ausgussteinen aufweisen. Uber unsere ersten Erfahrungen mit diesem Therapiekonzept haben wir bereits berichtet [1]. Bisher ist jedoch noch unklar, welche Spatergebnisse in diesen mit PCNL plus ESWL behandelten Patienten erzielt werden. In dieser Studie haben wir daher Patienten nachuntersucht, die 1984 und 1985 an unserer Klinik wegen Ausgussteinen kombiniert mit PCNL plus ESWL behandelt worden waren.

A rapid method for the screening of plasmids in transformed yeast strains

1988

A method for the rapid screening of plasmids in yeast cells has been developed. The method is an adaptation of the currently used alkaline lysis methods forEscherichia coli plasmids. Following the conditions described, several dozen ofSaccharomyces cerevisiae-transformed clones can be analyzed for their plasmid content in less than 2 h. The plasmids obtained by this procedure are suitable for restriction analysis or forE. coli andS. cerevisiae transformation.

Investigations on The Micro-Structure of Hardened Cement Pastes

1988

Abstract Creep is a mechanical property, that has to be taken into account in the design of concrete constructions. Earlier studies showed that creep of concrete, among other things, depends on the relative humidity of the environment and on the type of cement used. The origin of creep lies in the hydrated cement paste, which is present between the aggregates. This paper, based on a thesis of H.H. Willems (ref. 1) deals with the relation between the creep behaviour and the microstructure of hardened Portland (PC) and Portland-blastfurnace cement (PBC) pastes. At several relative humidities shrinkage and creep experiments have been performed with thin-walled hollow cylindrical specimens. Nex…

Appendicitis in der Schwangerschaft

1988

Wir haben die Falle von 62 schwangeren Patientinnen, welche unter der Diagnose Appendicitis operiert wurden untersucht um unser Konzept der fruhen Indikation zur Operation zu uberprufen. Die Diagnose bestatigte sich in 47 Fallen, nur in 7 Fallen konnte kein pathologischer Befund erhoben werden. Wir fanden 9 perforierte Appendices mit Peritonitis, dabei kam es in 6 Fallen zum Tod der Feten. Alle anderen Frauen konnten ihre Kinder termingerecht gebaren. Wegen des im Fall der Perforation erheblichen Risikos fur Mutter und Frucht sollte bei klinischem Verdacht einer akuten Appendicitis die Operation erfolgen.

Polar Sets in a Nonlinear Potential Theory

1988

In this lecture we discuss nonlinear potential theory based on “A-super-harmonic functions”; the theory can be viewed as a (nonlinear) extension of the classical study of superharmonic functions in ℝn.

Geografía: espacio social e imágenes de marca : el análisis de "Flor de mayo" de Vicente Blasco Ibáñez

1988

A TRAVES DE UN ANALISIS MINUCIOSO DE LA OBRA DEL NOVELISTA VALENCIANO VICENTE BLASCO IBAÑEZ (1867-1928), "FLOR DE MAYO", PODEMOS RECONSTRUIR EL ESPACIO VIVIDO DE LOS HABITANTES DEL CABANYAL DE PRINCIPIOS DE SIGLO. LA ACCION DE LA NOVELA, QUE FUE ESCRITA EN 1895, RECOGE LAS FORMAS DE VIDA DE LOS MARINEROS Y PESCADORES VALENCIANOS, EN SUS DIFERENTES ESPACIOS OPERATIVOS: EL ESPACIO DE LA PESCA, EL ESPACIO DEL CONTRABANDO, EL PROPIO PUEBLO DEL CABANYAL, LA CIUDAD DE VALENCIA, ARGEL, AFRICA, EL MEDITERRANEO. BLASCO IBAÑEZ RECOGIO CON VERACIDAD LOS ESPACIOS DE ACCION DE SUS PERSONAJES Y, GRACIAS A SU POPULARIDAD, HA CONTRIBUIDO A CREAR Y RECREAR ENTRE SUS LECTORES, LAS "IMAGENES DE MARCA" DE LUGA…

The ASHRAE clear sky model. An evaluation in the Mediterranean Zone

1988

Abstract The ASHRAE clear sky model in the version proposed by G. L. Powell is here applied to a yearly set of data for Palermo with small scale time intervals. The model is shown to yield computed values generally higher than the measured ones. New values for the atmospheric extinction coefficient are derived and proposed for the application to the Mediterranean atmosphere. A successful verification is performed using hourly data of Genoa, a location belonging to the same meteoclimatic area.

Los orígenes de la enfermería de salud pública

1988

Treatment of hypertension with a combination of nifedipine and atenolol compared with atenolol alone. Preliminary report.

1988

C—br insertion reactions in rhodium and iridium compounds containing an ortho-halo-arylphosphine. X-ray structures of two ortho-metallated compounds …

1988

Abstract A comparative study of the reaction of rh and ir complexes with the ortho-bromo-arylphosphine PCBr [PCBr = P(o-BrC6F4)(C6H5)2], is presented. Various PCBr complexes of Ir(I) and Rh(I) undergo rapid insertion of the metal atom into a CBr bond provided the phosphine is coordinated in a η2-mode (Pbr). If the Br coordination is substituted by a superior ligand such as CO or an olefin, no reaction occurs under normal conditions. PCBr complexes of the tervalent metals require a two-electron reduction step prior to the ortho-metallation reaction. Most intermediates were characterized by chemical and spectroscopic analysis. Two intermediates of general formula IrX2(η2-PC)(η-PCBr), [PC = …

Atmospheric Lead Deposition into Guarapina Lagoon, Rio de Janeiro State, Brazil

1988

The rate of anthropogenic mobilization of heavy metals is higher than the natural supply to the sedimentary environments. I n rivers, lakes and various other terrestrial areas, the drastic increase of heavy metals has been accredited to human activity (Tyler 1972). Erlenkeuser et al. (1974) suggest that Cd, Pb, Zn and Cu in the upper sediment sequence of sediment cores collected from Kiel Bight in the Baltic Sea, are the result of fossil fuel use in industries. Such assemblages have been identified in North America by Goldberg et al. (1977, 1979) from both coastal regions. Sediment cores taken from the deepest part of lakes and lagoons have been analysed to study the historical development …

A Consistent Formulation of the BEM within Elastoplasticity

1988

A symmetric-definite BEM formulation is derived by making alternatively use of two energy principles, i.e. the Hellinger-Reissner principle and a boundary min-max principle ad-hoc formulated. Two kinds of discretization are operated, one by boundary elements to model the system elastic properties, another by cell-elements to model the material plastic behavior. The cell yielding laws are expressed in terms of generalized variables and comply with the features of associated plasticity, due to the maximum plastic work theorem used for their derivation.

Dos países en la acción cultural europea

1988

Texto en español de la intervención de José Vidal-Beneyto en el "I Encuentro. Diálogo Cultural Hispano-Alemán en el marco de la política cultural europea". Santillana del mar, 27-28 de mayo de 1988. La versión que aquí se facilita no es la publicada sino el texto mecanografiado por el propio autor.

Transformaciones político-administrativas de la "Junta de Murs i Valls" tras la Nueva Planta borbónica (1707-1788)

1988

Coste y Financiación de la Universidad Española

1988

International audience

Enfermedad de las sinóstosis múltiples : (aportación de dos casos)

1988

The authors reported two cases of familiar squeletic alteration, autosomal dominance inheritance, with synostosis of the carpus and tarsus bones, symphalangism, brachydactyly and hypoplasia of the fíbula.

Graph languages defined by systems of forbidden structures: A survey

1988

This paper deals with different ways of defining graph languages. These are the so-called forbidden structures. Some results on decision problems, their complexity, and set theoretic closure properties are scetched. A normal form, the minimal systems, are given. Finally the influence of the different kinds of forbidden structures on the descriptive power of the systems is shown.

Electrooptic beam deflection with latex

1988

The use of latex in electrooptic devices is proposed. The static non linearity coefficient is shown to be approximatively 200 times the optical one. The theory of a beam deflector is developed and an explicit expression is given for the deflection angle versus the physical parameters of the sample Utilisation de suspensions aqueuses de latex dans un dispositif electro-optique. On montre que le coefficient statique de non-linearite devrait etre 200 fois plus eleve que le coefficient optique. Application a un deflecteur optique

Quelques éléments de comparaison des revenus en Andalousie

1988

International audience

La formación de las rentas del trabajo en Andalucía

1988

International audience; Este articulo analiza la distribución personal de las rentas de los asalariados y de los no asalariados en Andalucia. La primera sección describe las caracteristicas individuales de cada uno de estos colectivos, mientras la segunda estudia sus perfiles edad-rentas, a la luz de la teoria del capital humano. En la tercera sección estimamos funciones generadoras de rentas, a partir de las cuales se evalúan el rendimiento de la educación formal y el efecto de la experiencia profesional.

Sorption Studies on Large ZSM-5 Crystals: The Influence of Aluminium Content, The Type of Exchangeable Cations and the Temperature on Nitrogen Hyster…

1988

Abstract In comparison to polycrystalline powder large ZSM-5 crystals are best suited for high resolution sorption experiments. The nitrogen isotherms on HZSM-5 at 77 K reveal a pronounced hysteresis loop. The shape and position of the hysteresis relative to the pressure axis has been found to be affected by the aluminium content of the zeolite, the type of framework cation and the sorption temperature. The occurence of the hysteresis and its changes are assigned to a transition from a liquidlike to a solid-like adsorbed phase of nitrogen. The micropore volume v mp derived from the argon and nitrogen isotherm (s. Fig. 2b, first plateau) and calculated according to DUBININ-RADUSHKEVICH was c…

Central region in relativistic heavy ion collisions; results from hydrodynamic calculations and cascade simulation

1988

Results of three dimensional hydrodynamic calculations with boost invariant longitudinal expansion are presented with special emphasis on the transverse momentum spectra of hadrons and production rates of dileptons. The effect and signatures of transverse collective motion are discussed in detail. The hydrodynamic results which are based on the assumption of the existence of a first order phase transition and formation of an equilibrium mixed phase are compared with cascade simulation where the mixed phase is modelled in terms of plasma droplets embedded in a pion gas. The comparison shows a great deal of similarity between the two approaches lending further support for the hydrodynamic app…