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  • 1
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 3202-3204 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Monoclinic gallium oxide (β-Ga2O3) nanowires were synthesized by heat treating a composite material of GaAs and pre-evaporated Au at 1240 °C in dry oxygen atmosphere. The catalytic Au metal generated liquid nanoclusters that serve as reactive sites confining and directing the growth of β-Ga2O3 nanowires during the vapor-liquid-solid growth process. The β-Ga2O3 nanowires have diameters ranging from 20 to 50 nm and lengths of several micrometers. Photoluminescence measurement under excitation at 250 nm shows that the bulk β-Ga2O3 nanowires have a stable blue emission at 475 nm and an ultraviolet emission at 330 nm, which may be related to the defects such as the oxygen vacancy and the gallium–oxygen vacancy pair. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Fatigue & fracture of engineering materials & structures 24 (2001), S. 0 
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A statistical model for cleavage fracture in notched specimens of C-Mn steel has been proposed. This model is based on a recently suggested physical model. This statistical model satisfactorily describes the distributions of the cumulative failure probability and failure probability density of 36 notched specimens fractured at various loads at test temperature of −196 °C. The minimum notch toughness has also been discussed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Fatigue & fracture of engineering materials & structures 22 (1999), S. 0 
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: An elastic–plastic finite element method (FEM) is used to analyse the stress and strain distributions ahead of notches with various depths and flank angles in four-point bending (4PB) specimens of a C–Mn steel. By accurately measuring the distances of the cleavage initiation sites from the notch roots, the local cleavage fracture stress σf is measured. By increasing the notch depth and notch flank angle from 2.25 to 8.25 mm and 10 to 90°, respectively, the distributions of high stress and strain at the moment of fracture show considerable variations. However, the value of σf stays relatively constant. The critical fracture event is thus shown to be identical, i.e. the propagation of a ferrite grain-sized crack into the neighbouring matrix. It is concluded that σf is mainly determined by the length of the critical microcrack, while the notch geometry and its associated stress volume have little effect on the value of σf . The cleavage site ahead of a notch is determined by the stress distributions and the positions of the weakest grains.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Fatigue & fracture of engineering materials & structures 19 (1996), S. 0 
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract— The toughnesses of specimens of heterogeneous multipass weldments with various ratios of weld metal to base metal can be characterized by a single value of the local fracture stress within a narrow scatter band. Relationships were found between the normalized value of this parameter and the lower bound values of fracture toughness parameters such as the fracture load, the energy absorbed, and the crack opening displacement. These facts indicate that using such a toughness parameter, it is possible to assess a heterogeneous multipass weldment by a single value; within a narrow scatter band. Further experiments indicate that this parameter could be measured on specimens simulating the microstructure of the weakest zone where cleavage cracking is initiated.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1246
    Keywords: Styrene ; Biological monitoring ; Blood ; Alveolar air ; Normal population
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Blood styrene was measured by a gas chromatography-mass spectrometry method in 81 “normal people” and in 76 workers exposed to styrene. In the normal subjects, styrene was also tested in alveolar and environmental air. Styrene was found in nearly all (95%) blood samples. Average styrene levels in the normal subjects were 221 ng/1 in blood (Cb), 3 ng/1 in alveolar air (Ca) and 6 ng/1 in environmental air (Ci). Styrene levels did not differ significantly between smokers and non-smokers, 95% of values being below 512 ng/1 in Cb, 7 ng/1 in Ca and 15 ng/l in Ci. In workers with an average exposure to styrene of 204 μg/l, at the end of the workshift, mean blood styrene concentration was 1211 μg/l. In blood samples collected at the end of the Thursday shift, styrene levels were significantly higher (1590 μg/1) than those found at the end of the Monday shift (1068 μg/l. A similar difference was found in samples taken the morning after exposure (60 and 119 μg/l, respectively). Significant correlations between blood and environmental styrene were found both at the end of the shift and the morning after exposure (r=0.61 and 0.41, respectively). In workers occupationally exposed to styrene, 16 h after the end of the workshift, blood styrene (94 μg/l) was significantly higher than that found in the normal subjects (0.22 μg/l). The half-life of blood styrene was 3.9 h.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 100 (2000), S. 221-231 
    ISSN: 1432-2242
    Keywords: Key words Mitochondrial DNA ; RFLP analysis ; Triticum ; Aegilops ; Plasmon phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The first comprehensive analysis was made of restriction fragment length polymorphism (RFLP) of the mitochondrial (mt) DNA of two related genera, Triticum (wheat) and Aegilops. This led to clarification of the nature of mtDNA variability and the inference of the phylogeny of the mitochondrial genomes (=chondriome). Forty-six alloplasmic lines and one euplasmic line of common wheat (2n = 42, genomes AABBDD) carrying plasmons (cytoplasmic genomes) of 47 accessions belonging to 33 species were used. This consisted of nearly all the Triticum and Aegilops species. RFLP analysis, carried out with seven mitochondrial gene probes (7.0 kb in total) in combination with three restriction endonucleases, found marked variation: Of the 168 bands detected, 165 were variable (98.2%), indicative that there is extremely high mtDNA variability in these genera. This high variability is attributed to the variation present in the intergenic regions. Most of the variation was between chondriomes of different plasmon types; only 8 bands (4.8%) between those of the same plasmon types were variable, evidence of clear chondriome divergence between different plasmon types. The first comprehensive phylogenetic trees of the chondriome were constructed on the basis of genetic distances. All but 1 of the polyploids had chondriomes closely related to those of 1 putative parent, indicative of uniparental chondriome transmission at the time of polyploid formation. The chondriome showed parallel evolutionary divergence to the plastome (chloroplast genome). Use of a minimum set of 3 mtDNA probe-enzyme combinations is proposed for tentative plasmon type identification and the screening of new plasmon types in those genera.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Detailed observations were carried out on the metallurgical behaviour of joint-brazing of nickel based alloy Inconel 600 to Si3N4 with Ag71Cu27Ti2 filler metal, with emphasis on the interface between the filler metal and the Inconel 600 and the effects of nickel which was the predominant element in the base metal. Based on the experimental results, the mechanism of bonding Inconel 600 to the filler metal is attributed to the diffusion of silver and copper along the grain boundaries of the Inconel 600, which results in mechanical anchoring. The effects of nickel on the metallurgical behaviour of filler metal are summed up as enhancing the separation of silver- and copper-rich liquid phases from the molten filler metal; combining titanium and decreasing its activity in the reaction with Si3N4 at the interface with ceramics; promoting the diffusion of silver and copper into Inconel 600; and facilitating the flow of filler metal over the surface of Inconel 600.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Advances in contraception 4 (1988), S. 287-293 
    ISSN: 1573-7195
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Resumé On a étudié par spectrophotométrie d'absorption atomique et histo-chimie la quantité et al localisation du cuivre libéré par un DIU au cuivre dans l'endomètre de lapines portant ce dispositif pendant 30 jours. Le cuivre libéré était principalement concentré dans le cytoplasme de l'épithélium cavitaire et glandulaire. Toutefois, si la continuité de l'épithélium n'était pas parfaite, par suite d'une atteinte par le dispositif, le cuivre pouvait être décelé dnas les cellules du stroma, qui semblaient être des leucocytes neutrophiles ou des lymphocytes. La concentration moyenne de cuivre dans le tissu utérin provenant de la corne portant le DIU au cuivre (82.24 μg/g poids sec) était significativement plus élevée que celle de l'élément controlatéral du dispositif (14.48 μg/g poids sec) et avait également tendance à être plus élevée que celle de la corne portant le dispositif en acier inoxydable (39.97 μg/g poids sec) et de sa corne controlatérale (18.03 μg/g poids sec).
    Abstract: Resumen Espectofotometría de absorción atómica e histoquímica fueron utilizadas para estudiar el contenido y la localización del cobre liberado por un DIU con cobre en el endometrio de conejas con el dispositivo durante 30 días. El cobre liberado se acumuló principalmente en el lumen y en el citoplasma del epitelio glandular. Sin embargo, si la integridad del epitelio estaba imperfecta debido a la presencia del dispositivo, el cobre podía ser detectado en células des estroma que parecían ser leucocitos neutrófilos o linfocitos. La concentración media de cobre en el tejido del cuerno uterino con el DIU con cobre (82.24 μg/g peso seco) fué significativamente mas alta que la del opuesto (14.48 μg/g peso seco) y también tendía a ser mas alta que la del cuerno con el dispositivo de acero inoxidable (32.97 μg/g peso seco) y su cuerno opuesto (18.03 μg/g peso seco).
    Notes: Abstract Atomic absorption spectrophotometry and histochemistry have been employed to study the content and localization of copper released from a CuIUD in the endometrium of rabbits bearing the copper device for 30 days. The released copper was mainly accumulated in the luminal and glandular epithelial cytoplasm. However, if the succession of the epithelia was imperfect due to the impairment by the device, copper could be detected in the stroma cells, which appeared to be neutrophilic leukocytes or lymphocytes. The mean concentration of copper in the uterine tissue of the CuIUD-bearing horn (82.24 μg/g dry weight) was significantly higher than that of the contralateral one (14.48 μg/g dry weight), and also tended to be higher than that of the horn bearing the stainless steel device (32.97 μg/g dry weight) and its contralateral horn (18.03 μg/g dry weight).
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