Exilliteratur und Identitätsdiskurs am Beispiel Shanghai. Eine archivalische Spurensuche

The present study analyzes unpublished manuscripts by German language Jewish authors who escaped from Nazi Germany to Shanghai. Although the experience of exile in China is a common topic of these sources, images of individual and collective identity vary significantly. After some introductory remarks on Shanghai as an exile destination and on the archival sources and their (almost unknown) authors, I will concentrate on the various dimensions of identity that emerge in selected narratives by Fritz Friedländer (1901-1980), Wolfgang Weiss (1924-1973), Irma Cohn Erman (1908-2000), and Alfred Walter Kneucker (1904-1960)

Hot deformation behavior of a ni‐based superalloy with suppressed precipitation

Abstract:Inconel ® 718 is a well-known nickel-based super-alloy used for high-temperature applicationsafter thermomechanical processes followed by heat treatments. This work describes theevolution of the microstructure and the stresses during hot deformation of a prototype alloy namedIN718WP produced by powder metallurgy with similar chemical composition to the matrix ofInconel ® 718. Compression tests were performed by the thermomechanical simulator Gleeble3800 in a temperature range from 900 to 1025 °C, and strain rates scaled from 0.001 to 10 s. Flow curves of IN718WP showed similar features to those of Inconel ® 718. The relative stress softening of the IN718WP was comparable to standard alloy Inconel ® 718 for the highest strain rates. Large stress softening at low strain rates may be related to two phenomena: the fast recrystallization rate, and the coarsening of micropores driven by diffusion. Dynamic recrystallization grade and grain size were quantified using metallography. The recrystallization grade increased as the strain rate decreased, although showed less dependency on the temperature. Dynamic recrystallization occurred after the formation of deformation bands at strain rates above 0.1 s-1 and after the formation of subgrains when deforming at low strain rates. Recrystallized grains had a large number of sigma 3 boundaries, and their percentage increased with strain rate and temperature. The calculated apparent activation energy and strain rate exponent value were similar to those found for Inconel ® 718 when deforming above the solvus temperature.Keywords: ; hot deformation; Gleeble; recrystallization; flow modelling approachFil: Lizzi, Franco. Universidad Nacional del Comahue; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería. Universidad Nacional del Comahue. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería; Argentina. Christian Doppler Laboratory for Design of High-Performance Alloys by Thermomechanical Processing; AustriaFil: Pradeep, Kashyap. Graz University Of Technology.; Austria. Christian Doppler Laboratory for Design of High-Performance Alloys by Thermomechanical Processing; AustriaFil: Stanojevic, Aleksandar. Voestalpine Böhler Aerospace; AustriaFil: Sommadossi, Silvana Andrea. Universidad Nacional del Comahue; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería. Universidad Nacional del Comahue. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Poletti, MARIA CECILIA. Christian Doppler Laboratory for Design of High-Performance Alloys by Thermomechanical Processing; Austria. Graz University Of Technology.; Austri

Transformaciones de fases sólido-sólido en el sistema al-ni. parte II

Uno de los sistemas que pertenece a las superaleaciones es el de Aluminio-Níquel. El objetivo de este trabajo es profundizar el análisis de sus fases intermetálicas (FIs) de mayor contenido de Ni, a 1000 y 1170°C, las cuales poseen atractivas características tecnológicas y diversas aplicaciones a nivel industrial. El proceso de Unión por Transición de Fase Líquida (Transition Liquid Phase Bonding, TLPB) permite obtener uniones de alta estabilidad mecánica y térmica, resistentes a la corrosión, y la formación de capas intermetálicas (CIs)/FIs de buena adhesividad con el sustrato, mediante procesos de difusión-reacción. Las CIs de mayor contenido de Ni crecen consumiendo a las capas de mayor contenido de Al. La secuencia es Al/C1/C2/C3/C4/C5/Ni, siendo C1: Al3Ni, C2: Al3Ni2, C3: AlNi-rica en Al, C4: AlNi-pobre en Al y C5: AlNi3. Se realizaron estudios de morfología, cinética, composición química y comportamiento mecánico, utilizando técnicas de microscopía óptica, electrónica (SEM-EDS) y microdureza Vickers, en C3, C4 y C5 con extensos tratamientos térmicos (TT). La capa C3 presentó una morfología porosa, disminuyendo su espesor a costa de C4 y un acelerado crecimiento de C5. C4 evidenció a ambas temperaturas una morfología lisa y otra martensítica, donde C4-martensita se consumió en última instancia a costa de C5. A ambas temperaturas y extensos TT, creció una fase de morfología porosa que llamamos C5-Superior. Los resultados de composición química y de dureza evidenciaron que la misma, es similar a C5 y se correlaciona con AlNi3. El estudio cinético reportó que a 1000°C, las capas C4 y C5 tienen un crecimiento parabólico controlado por difusión. A 1170°C, C4 creció con un control por reacción en la interface, mientras que C5, cambió la modalidad parabólica de crecimiento cuando desapareció C3, incrementando sustancialmente su constante de crecimiento. Los valores de microdureza Vickers disminuyeron con el incremento del contenido de Ni, a ambas temperaturas.One of the systems belonging to the superalloys is Nickel/Aluminum. The aim of this work is to deepen the analysis of this superalloy’s inter-metallic phases (IPs) of higher Ni content, at 1000 and 1170°C, which have attractive technological characteristics and diverse industrial applications. The Transition Liquid Phase Bonding (TLPB) process allows obtaining joints with higher thermal and mechanical stability, corrosion resistance, and formation of inter-metallic layers (ILs)/IPs of good adhesion to the substrate through diffusion-reaction processes. The ILs with the highest Ni concentration grow by consuming the layers with the highest content of Al. The sequence is Al/L1/L2/L3/L4/L5/Ni, being L1: Al3Ni, L2: Al3Ni2, L3: AlNi(Al rich), L4: AlNi(Al poor) and L5: AlNi3. Morphology, kinetics, chemical composition and mechanical behavior studies were performed, using optical and electronic microscopy (SEM/EDS) and Vickers micro-hardness techniques in layers L3, L4 and L5 under extensive thermal treatments (TT). Layer L3 presented a porous morphology, decreasing its thickness at the expense of L4 and an accelerated growth of L5. L4 showed a smooth and a martensitic morphology at both temperatures, where L4-martensite was ultimately consumed at the expense of L5. A phase of porous morphology that we called L5- Superior, grew at both temperatures and extensive TT. The results of chemical composition and micro-hardness showed that it is similar to L5 and correlates with AlNi3 phase. The kinetic study reported that L4 and L5 exhibit parabolic growth, controlled by diffusion, at 1000 °C. L4 grew, controlled by interface reaction, at 1170°C, while L5 changed the parabolic growth when L3 disappeared, increasing its growth rate constant. Vickers micro-hardness values decreased with Ni concentration at both temperatures.Fil: Segobia, Sofía. Universidad Nacional del Comahue; ArgentinaFil: Sommadossi, Silvana Andrea. Universidad Nacional del Comahue; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería. Universidad Nacional del Comahue. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería; Argentin

Dft-cef approach for the thermodynamic properties and volume of stable and metastable al–ni compounds

The Al–Ni system has been intensively studied both experimentally and theoretically. Previous first-principles calculations based on density-functional theory (DFT) typically investigate the stable phases of this system in their experimental stoichiometry. In this work, we present DFT calculations for the Al–Ni system that cover stable and metastable phases across the whole composition range for each phase. The considered metastable phases are relevant for applications as they are observed in engineering alloys based on Al–Ni. To model the Gibbs energies of solid phases of the Al–Ni system, we combine our DFT calculations with the compound energy formalism (CEF) that takes the Bragg–Williams–Gorsky approximation for the configurational entropy. Our results indicate that the majority of the investigated configurations have negative energy of formation with respect to Al fcc and Ni fcc. The calculated molar volumes for all investigated phases show negative deviations from Zen’s law. The thermodynamic properties at finite temperatures of individual phases allow one to predict the configurational contributions to the Gibbs energy. By applying a fully predictive approach without excess parameters, an acceptable topology of the DFT-based equilibrium phase diagram is obtained at low and intermediate temperatures. Further contributions can be added to improve the predictability of the method, such as phonons or going beyond the Bragg–Williams–Gorsky approximation that overestimates the stability range of the ordered phases. This is clearly demonstrated in the fcc order/disorder predicted metastable phase diagramFil: Tumminello, Silvana Deisy Paulina. Universidad Nacional del Comahue; Argentina. Universidad Nacional de San Martín; Argentina. Ruhr Universität Bochum; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería. Universidad Nacional del Comahue. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Palumbo, Mauro. Ruhr Universität Bochum; AlemaniaFil: Koßmann, Jörg. Ruhr Universität Bochum; AlemaniaFil: Hammerschmidt, Thomas. Ruhr Universität Bochum; AlemaniaFil: Alonso, Paula Regina. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Instituto Sabato; ArgentinaFil: Sommadossi, Silvana Andrea. Universidad Nacional del Comahue; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería. Universidad Nacional del Comahue. Instituto de Investigación En Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Fries, Suzana G. Ruhr Universität Bochum; Alemani

Molecular basis for the enantioselectivity of HIV-1 reverse transcriptase: Role of the 3′-hydroxyl group of the L-(β)-ribose in chiral discrimination between D- and L-enantiomers of deoxy- and dideoxy-nucleoside triphosphate analogs

In order to identify the basis for the relaxed enantioselectivity of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) and to evaluate possible cross-resistance patterns between L-nucleoside-, D-nucleoside- and non-nucleoside RT inhibitors, to be utilised in anti-HIV-1 combination therapy, we applied an in vitro approach based on the utilisation of six recombinant HIV-1 RT mutants containing single amino acid substitutions known to confer Nevirapine resistance in treated patients. The mutants were compared on different RNA/DNA and DNA/DNA substrates to the wild type (wt) enzyme for their sensitivity towards inhibition by the D- and L-enantiomers of 2′-deoxy- and 2′,3′-dideoxynucleoside triphosphate analogs. The results showed that the 3′-hydroxyl group of the L-(β)-2′-deoxyribose moiety caused an unfavourable steric hindrance with critic residues in the HIV-1 RT active site and this steric barrier was increased by the Y181I mutation. Elimination of the 3′-hydroxyl group removed this hindrance and significantly improved binding to the HIV-1 RT wt and to the mutants. These results demonstrate the critical role of both the tyrosine 181 of RT and the 3′-position of the sugar ring, in chiral discrimination between D- and L-nucleoside triphosphates. Moreover, they provide an important rationale for the combination of D- and L-(β)-dideoxynucleoside analogs with non-nucleoside RT inhibitors in anti-HIV chemotherapy, since non-nucleoside inhibitors resistance mutations did not confer crossresistance to dideoxynucleoside analog

Crystal structure of Cu-Sn-In alloys around the {\eta} phase field studied by neutron diffraction

The study of the Cu-Sn-In ternary system has become of great importance in recent years, due to new environmental regulations forcing to eliminate the use of Pb in bonding technologies for electronic devices. A key relevant issue concerns the intermetallic phases which grow in the bonding zone and are determining in their quality and performance. In this work, we focus in the {\eta}-phase (Cu2In or Cu6Sn5) that exists in both end binaries and as a ternary phase. We present a neutron diffraction study of the constitution and crystallography of a series of alloys around the 60 at.% Cu composition, and with In contents ranging from 0 to 25 at.%, quenched from 300\degreeC. The alloys were characterized by scanning electron microscopy, probe microanalysis and high-resolution neutron diffraction. The Rietveld refinement of neutron diffraction data allowed to improve the currently available model for site occupancies in the hexagonal {\eta}-phase in the binary Cu-Sn as well as in ternary alloys. For the first time, structural data is reported in the ternary Cu-Sn-In {\eta}-phase as a function of composition, information that is of fundamental technological importance as well as valuable input data for ongoing modelisations of the ternary phase diagram.Comment: 8 pages, 10 figure

Synthesis, physicochemical and pharmacokinetic studies of potential prodrugs of β-L-2'-deoxycytidine, a selective and specific anti-HBV agent

β-L-2′-Deoxycytidine (β-L-dC) is a potent, selective and specific anti-hepatitis B virus (HBV) agent. To improve its oral bioavailability, several derivatives involving sugar or base acylation, as well as N4-derivatization with an N,N-(dimethyl-amino)methylene function, were synthesized. The physicochemical characteristics (including chemical stabilities, solubilities and distribution coefficient values) and pharmacokinetics of these compounds were determined and compared with those of the parent drug, β-L-dC. Presented in part at the 14th International Conference on Antiviral Research, Seattle, Washington, USA, 8–13 April 2001. Antiviral Reseach 2001; 50:A79

Initiating antiretrovirals during tuberculosis treatment: a drug safety review

Introduction: Integrating HIV and tuberculosis (TB) treatment can reduce mortality substantially. Practical barriers to treatment integration still exist and include safety concerns related to concomitant drug use because of drug interactions and additive toxicities. Altered therapeutic concentrations may influence the chances of treatment success or toxicity. Areas covered: The available data on drug-drug interactions between the rifamycin class of anti-mycobacterials and the non-nucleoside reverse transcriptase inhibitor and the protease inhibitor classes of antiretrovirals are discussed with recommendations for integrated use. Additive drug toxicities, the impact of immune reconstitution inflammatory syndrome (IRIS) and the latest data on survival benefits of integrating treatment are elucidated. Expert opinion: Deferring treatment of HIV to avoid drug interactions with TB treatment or the occurrence of IRIS is not necessary. In the integrated management of TB-HIV co-infection, rational drug combinations aimed at reducing toxicities while effecting TB cure and suppressing HIV viral load are possible

Enhanced Uridine Bioavailability Following Administration of a Triacetyluridine-Rich Nutritional Supplement

Uridine is a therapy for hereditary orotic aciduria and is being investigated in other disorders caused by mitochondrial dysfunction, including toxicities resulting from treatment with nucleoside reverse transcriptase inhibitors in HIV. Historically, the use of uridine as a therapeutic agent has been limited by poor bioavailability. A food supplement containing nucleosides, NucleomaxX®, has been reported to raise plasma uridine to supraphysiologic levels