scholarly journals Constant structure creep experiments on aluminium

2011 ◽  
Vol 49 (05) ◽  
pp. 307-318 ◽  
Author(s):  
K. MILICKA
Keyword(s):  
Constant Structure

Carbide precipitation and chromium depletion on coherent twin boundaries in deformed 304 stainless steels

1992 ◽  
Vol 50 (2) ◽  
pp. 1216-1217
Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D.J. Matlock ◽  
W.W. Fisher ◽  
P.M. Tarin ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Stainless Steels ◽  
Interfacial Free Energy ◽  
Carbide Precipitation ◽  
Twin Boundaries ◽  
Invariant Structure ◽  
Heat Treated ◽  
Constant Structure ◽  
Cr Depletion

Coherent annealing-twin boundaries are constant structure and energy interfaces with an average interfacial free energy of ∼19mJ/m2 versus ∼210 and ∼835mJ/m2 for incoherent twins and “regular” grain boundaries respectively in 304 stainless steels (SS). Due to their low energy, coherent twins form carbides about a factor of 100 slower than grain boundaries, and limited work has also shown differences in Cr-depletion (sensitization) between twin versus grain boundaries. Plastic deformation, may, however, alter the kinetics and thermodynamics of twin-sensitization which is not well understood. The objective of this work was to understand the mechanisms of carbide precipitation and Cr-depletion on coherent twin boundaries in deformed SS. The research is directed toward using this invariant structure and energy interface to understand and model the role of interfacial characteristics on deformation-induced sensitization in SS. Carbides and Cr-depletion were examined on a 20%-strain, 0.051%C-304SS, heat treated to 625°C-4.5h, as described elsewhere.

Constant structure creep experiments in aluminum, AlMg and alzn solid solutions

1997 ◽  
Vol 234-236 ◽  
pp. 912-914
Author(s):  
K. Milicka ◽  
F. Dobes ◽  
J. Slameníková
Keyword(s):  
Solid Solutions ◽  
Constant Structure

Phytoplankton photoadaptation during the spring period in Lake Zürich

1995 ◽  
Vol 32 (4) ◽  
pp. 59-62 ◽  
Author(s):  
Ferdinand Schanz ◽  
Judith Burri
Keyword(s):  
Species Composition ◽  
Light Availability ◽  
Plankton Community ◽  
Short Term ◽  
Spring Period ◽  
Constant Structure ◽  
Phytoplankton Communities ◽  
Lake Zürich

Long- and short-term photoadaptations as a response to increased light availability in spring phytoplankton communities in Lake Zürich have been investigated. At various stages fundamental changes in species composition and species adaptation in a plankton community of approximately constant structure were apparent.

Development of the Human Biceps Brachii Tendon and Coracoglenoid Ligament (7th-12th Week of Development)

2017 ◽  
Vol 203 (6) ◽  
pp. 365-373 ◽  
Author(s):  
Crótida de la Cuadra-Blanco ◽  
Luis A. Arráez-Aybar ◽  
Jorge A. Murillo-González ◽  
Manuel E. Herrera-Lara ◽  
Juan A. Mérida-Velasco ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Optical Microscope ◽  
Coracoid Process ◽  
Anatomical Structure ◽  
Human Embryos ◽  
Glenoid Labrum ◽  
Labral Lesion ◽  
Constant Structure ◽  
Biceps Brachii Tendon ◽  
Long Head

The goal of this study is to clarify the development of the long head of the biceps brachii tendon (LHBT) and to verify the existence and development of the coracoglenoid ligament. Histological preparations of 22 human embryos (7-8 weeks of development) and 43 human fetuses (9-12 weeks of development) were studied bilaterally using a conventional optical microscope. The articular interzone gives rise to the LHBT, glenoid labrum, and articular capsule. During the fetal period, it was observed that in 50 cases (58%), the LHBT originated from both the glenoid labrum and the scapula, while in 36 cases (42%), it originated only from the glenoid labrum. The coracoglenoid ligament, first described by Sappey in 1867, is a constant structure that originates at the base of the coracoid process and projects toward the glenoid labrum zone, which is related to the origin of the LHBT. The coracoglenoid ligament was more easily identifiable in the 36 cases in which the LHBT originated only from the glenoid labrum. We suggest that the coracoglenoid ligament is a constant anatomical structure, is not derived from the articular interzone unlike the LHBT, and contributes to the fixation of the glenoid labrum in the scapula in cases in which the LHBT originated only from the glenoid labrum. We postulate that, when the LHBT is fixed only at the glenoid labrum, alterations in the coracoglenoid ligament could lead to a less sufficient attachment of the glenoid labrum to the scapula which could predispose to a superior labral lesion.

scholarly journals Estimating High-Affinity Methanotrophic Bacterial Biomass, Growth, and Turnover in Soil by Phospholipid Fatty Acid 13C Labeling

2006 ◽  
Vol 72 (6) ◽  
pp. 3901-3907 ◽  
Author(s):  
P. J. Maxfield ◽  
E. R. C. Hornibrook ◽  
R. P. Evershed
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acid ◽  
Phospholipid Fatty Acid ◽  
Bacterial Biomass ◽  
Isotope Ratio Mass Spectrometry ◽  
Dry Weight ◽  
Methane Oxidizing Bacteria ◽  
Constant Structure ◽  
Carbon Recycling ◽  
Time Point

ABSTRACT A time series phospholipid fatty acid (PLFA) 13C-labeling study was undertaken to determine methanotrophic taxon, calculate methanotrophic biomass, and assess carbon recycling in an upland brown earth soil from Bronydd Mawr (Wales, United Kingdom). Laboratory incubations of soils were performed at ambient CH4 concentrations using synthetic air containing 2 parts per million of volume of 13CH4. Flowthrough chambers maintained a stable CH4 concentration throughout the 11-week incubation. Soils were analyzed at weekly intervals by gas chromatography (GC), GC-mass spectrometry, and GC-combustion-isotope ratio mass spectrometry to identify and quantify individual PLFAs and trace the incorporation of 13C label into the microbial biomass. Incorporation of the 13C label was seen throughout the experiment, with the rate of incorporation decreasing after 9 weeks. The δ13C values of individual PLFAs showed that 13C label was incorporated into different components to various extents and at various rates, reflecting the diversity of PLFA sources. Quantitative assessments of 13C-labeled PLFAs showed that the methanotrophic population was of constant structure throughout the experiment. The dominant 13C-labeled PLFA was 18:1ω7c, with 16:1ω5 present at lower abundance, suggesting the presence of novel type II methanotrophs. The biomass of methane-oxidizing bacteria at optimum labeling was estimated to be about 7.2 � 106 cells g−1 of soil (dry weight). While recycling of 13C label from the methanotrophic biomass must occur, it is a slower process than initial 13CH4 incorporation, with only about 5 to 10% of 13C-labeled PLFAs reflecting this process. Thus, 13C-labeled PLFA distributions determined at any time point during 13CH4 incubation can be used for chemotaxonomic assessments, although extended incubations are required to achieve optimum 13C labeling for methanotrophic biomass determinations.

scholarly journals Large-mode-area photonic crystal fiber with double lattice constant structure and low bending loss

2011 ◽  
Vol 19 (23) ◽  
pp. 22628 ◽  
Author(s):  
Marek Napierała ◽  
Tomasz Nasilowski ◽  
Elżbieta Bereś-Pawlik ◽  
Paweł Mergo ◽  
Francis Berghmans ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Lattice Constant ◽  
Large Mode Area ◽  
Crystal Fiber ◽  
Bending Loss ◽  
Constant Structure ◽  
Mode Area

scholarly journals The Anatomy of the Dorsal Capsulo-Scapholunate Septum: A Cadaveric Study

2017 ◽  
Vol 06 (03) ◽  
pp. 244-247 ◽  
Author(s):  
Marina Tommasini Carrara de Sambuy ◽  
Tanya Burgess ◽  
Christophe Mathoulin ◽  
Adeline Cambon-Binder
Keyword(s):  
Dorsal Surface ◽  
Anatomical Study ◽  
Biomechanical Properties ◽  
Scapholunate Ligament ◽  
Maximum Width ◽  
Interosseous Ligament ◽  
Gothic Architecture ◽  
Constant Structure ◽  
Fresh Frozen ◽  
The Mean

Background Tears of the dorsal radiocarpal capsule at the level of the scapholunate interosseous ligament (SLIL) have recently been described in association with predynamic scapholunate instability. Purpose The aim of this anatomical study of the dorsal capsulo-scapholunate septum (DCSS) was to examine the connection of the dorsal capsule on the SLIL and dorsal intercarpal ligament (DICL). Methods Fourteen fresh frozen wrists from seven adult cadavers were dissected through a dorsal approach. Any dorsal attachment of the DICL on the dorsal surface of the SLIL, that is, the DCSS, was identified and measured (height and width). Results The DCSS was consistently found connecting the DICL, the dorsal radiocarpal capsule, and the dorsal aspect of the SLIL. It was formed by the confluence of three arches like intersecting ribs in gothic architecture. The mean dimensions of the DCSS were 5.8 mm in height and 4.0 mm in maximum width. Conclusion The DCSS that connects the SLIL with the dorsal capsule and DICL could be a constant structure of dorsal wrist. Further investigation is required to study the histology of the DCSS and its biomechanical properties in isolation to know whether the DCSS can be considered a secondary stabilizer of the scapholunate ligament complex. Clinical Relevance A better anatomical knowledge of scapholunate ligament complex could help understand and manage instability of the wrist.

scholarly journals Studies on the Comparative Physiology of Chara Australis II. The Fine Structure of The Protoplast

1964 ◽  
Vol 17 (2) ◽  
pp. 372 ◽  
Author(s):  
TC CHAMBERS ◽  
FV MERCER
Keyword(s):  
Fine Structure ◽  
Unit Volume ◽  
Higher Plants ◽  
Linear Phase ◽  
Comparative Physiology ◽  
Thin Sections ◽  
Golgi Bodies ◽  
Constant Structure ◽  
Parenchyma Cells ◽  
Chara Australis

The fine structure of the internodal cells of G. australis in the linear phase of cell expansion is described from electron micrographs of thin sections of osmium. and permanganate-fixed material. . The static picture obtained is basically similar to that of the parenchyma cells of higher plants as established by electron-microscope observations. A unit volume of protoplast has the same fine structure in cells ranging from 1 em to many centimetres in length, and contains cell wall, plasmalemma, tonoplast, endoplasmic reticulum, golgi bodies, micro somes, mitochondria, chloro_ plasts, nuclei, and other inclusions. This constant structure may account for the constant metabolism per unit volume of protoplast during the linear phase of development. A brief discussion of the possible significance of this picture of the structure of the internodal protoplast to the functional activity of the cell is given.

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