scholarly journals Lattice Curvatures Produced by the Heavy Deformation of Polycrystals

1980 ◽  
Vol 4 (1) ◽  
pp. 41-56 ◽  
Author(s):  
I. L. Dillamore

An outline nomenclature is given for some of the microstructural heterogeneities found in heavily deformed single phase cubic metals. The relationship of these features to the development of lattice curvatures is discussed and the importance of lattice curvatures in relating deformation and annealing textures is assessed.

2014 ◽  
Vol 945-949 ◽  
pp. 2873-2879
Author(s):  
Zhong An Yu ◽  
Ming Zhao Cheng ◽  
Pei Yu Guo ◽  
Neng Ling Tai

The application of traditional distance relay for four-parallel transmission lines is adversely affected by the mutual coupling between the lines. The result will lead to not achieved measured impedance calculation. And it has an effect on the operation of ground protection. In this paper, A new ground distance algorithm is proposed for single-phase grounding fault of four-parallel transmission lines. Based on the case of single-phase grounding fault, The first the relationship between fault point voltage and the voltage at protection installed location is presented by twelve-sequence component method. In the basis, According to the relationship of phase corner between the fault voltage and the fault current to eliminate the effect of fault voltage. The simulation results show that the new scheme has high sensitivity and reliability under different single-phase grounding fault of four-parallel transmission lines.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
David S Liebeskind ◽  
Leticia C Rebello ◽  
Gisele S Silva ◽  
Daniel G Abud ◽  
Francisco Jose MontAlverne ◽  
...  

Background: The RESILIENT randomized trial of endovascular therapy for anterior circulation stroke within 8 hours of symptom onset excluded subjects with poor collaterals. We analyzed the relationship of CTA collateral grade with respect to subsequent infarct growth over 24 hours, with and without revascularization. Methods: The independent RESILIENT imaging and angiography core lab scored baseline CTA Tan collateral grade (0-3) and CT ASPECTS scores at baseline and 24 hours in both arms. ASITN collateral grade (0-4) was adjudicated prior to revascularization in the interventional arm. Descriptive statistics, univariate, multivariate and ANOVA related CTA collateral grade with 24-hour infarct growth. Results: 210/221 (95%) subjects (median age 67 (53-76) years; 48% women) in RESILIENT had baseline single-phase CTA available to the core lab evaluation. CTA collateral grade was complete (grade 3) in 106 (50.5%), grade 2 (50-99%) in 68 (32.4%), grade 1 (1-49%) in 36 (17.1%), with no collaterals in 0. The extent of collaterals was more robust in the medical arm (55.0% grade 3, 31.4% grade 2, 13.3% grade 1) compared to the interventional arm (45.7% grade 3, 33.3% grade 2, 21.0% grade 1), although this finding was not statistically significant (p=0.11). In the interventional arm, the extent of CTA collaterals had a strong correlation with ASITN grade (ρ=0.59, p<0.001). Overall, the median baseline ASPECTS (n=210) was 8 (range 6-10) with CTA grade 3 collaterals, 8 (5-9) with grade 2 and 7 (2-10) with grade 1. For 24-hour ASPECTS (n=202) the median was 6 (range 0-10) with CTA grade 3 collaterals, 4 (0-8) with grade 2 and 3 (0-7) with grade 1. 24-hour infarct growth (n=200) was greater in those with worse collateral grade, p<0.001. 24-hour infarct growth was more pronounced in the medical arm compared with subjects treated with revascularization in the interventional arm, p<0.01. Multivariate analysis showed that 24-hour infarct growth was worse in the medical arm, despite more extensive collaterals at baseline p=0.001. Conclusions: In RESILIENT, CTA collateral grade was linked with higher ASPECTS and less infarct growth over 24 hours. Despite more robust collaterals in the medical arm, greater infarct growth occurred without revascularization or endovascular therapy.


Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
Leon Dmochowski

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.


Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.


1993 ◽  
Vol 2 (3) ◽  
pp. 52-55 ◽  
Author(s):  
Michael Collins ◽  
Robert McDonald ◽  
Robert Stanley ◽  
Timothy Donovan ◽  
C. Frank Bonebrake

This report describes an unusual and persistent dysphonia in two young women who had taken a therapeutic regimen of isotretinoin for intractable acne. We report perceptual and instrumental data for their dysphonia, and pose a theoretical basis for the relationship of dysphonia to this drug. We also provide recommendations for reducing the risk of acquiring a dysphonia during the course of treatment with isotretinoin.


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