A method for determining r-value of aluminum sheets with the Portevin-Le Chatelier effect

Correlation between the deep-drawability of commercially pure aluminum sheets and the r value is investigated in detail. First, sheets with various r values are specially made for this study, and the conditions for making extra high r-value sheets are clarified. Then, it is found from the deep-drawability test that the limiting drawing ratio has a positive though weak correlation with r value. The reasons are considered both from the standpoints of drawing resistance and fracture strength and attributed to the variations of the r value during working. As a result, finding a strain path to enhance the r value is considered to be a future problem in the improvement of deep-drawability.

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Improvement in the r-value of aluminum sheets by differential-friction rolling

Scripta Materialia ◽

10.1016/j.scriptamat.2007.08.024 ◽

2007 ◽

Vol 57 (12) ◽

pp. 1109-1112 ◽

Cited By ~ 33

Author(s):

H. Utsunomiya ◽

T. Ueno ◽

T. Sakai

Keyword(s):

Aluminum Sheets ◽

R Value

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Assessment of Deep-Drawability of Mild Steel Sheets in Consideration of r-Value Change During Processing

Journal of Engineering for Industry ◽

10.1115/1.3187897 ◽

1988 ◽

Vol 110 (4) ◽

pp. 376-383 ◽

Cited By ~ 3

Author(s):

N. Kawai ◽

N. Hayashi ◽

S. Matsui

Keyword(s):

Mild Steel ◽

Pure Aluminum ◽

Plastic Anisotropy ◽

Drawing Ratio ◽

Deep Drawability ◽

Steel Sheets ◽

Aluminum Sheets ◽

Commercially Pure ◽

Strain Paths ◽

R Value

In the previous study, it was found that the plastic anisotropy of commercially pure aluminum sheets changed during the deep-drawing process, and that this change influenced markedly the deep-drawability. In the present study we discuss the deep-drawability of mild steel sheets with a crystal structure different from aluminum. The following have been confirmed: (1) The limiting drawing ratio correlates positively and nonlinearly with average r value (r¯ value). (2) Fracture strength correlates positively with r¯ value as in the theory, but the relation between them is nonlinear. Maximum drawing load remains almost constant irrespective of r¯ value against the theory. These relations can be connected with the result of (1). (3) The relations in (2) can be explained by the r¯ value measured from sheets prestrained in equibiaxial tension and pure shear, which resemble the strain paths of fracture site at punch profile and flange, respectively. (4) The results of (2) and (3) are quite different from those of commercially pure aluminum sheets.

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ARIC Hemostasis Study-IV. Intraindividual Variability and Reliability of Hemostatic Factors

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653761 ◽

1995 ◽

Vol 73 (02) ◽

pp. 256-260 ◽

Cited By ~ 19

Author(s):

Nghia D Nguyen ◽

Habib Ghaddar ◽

Valarie Stinson ◽

Lloyd E Chambless ◽

Kenneth K Wu ◽

...

Keyword(s):

Plasminogen Activator ◽

Plasminogen Activator Inhibitor ◽

Protein S ◽

Coagulation Factors ◽

Total Variance ◽

Intraindividual Variability ◽

Plasminogen Activator Inhibitor 1 ◽

Platelet Factor ◽

Hemostatic Factors ◽

R Value

SummaryWe have recently reported the short-term intraindividual variability of several coagulation factors and inhibitors included in the ARIC study (Chambless et al. Ann Epidemiol 1992; 2:723). In this paper, we reported the intraindividual variability results of additional hemostatic factors. Blood samples were collected for hemostatic assays three times at 1-2-week intervals from 39 subjects recruited from 4 ARIC field centers. The contributions of within-person, processing and assay (designated “method”) and between-person variances to the total variance were estimated and from them the reliability coefficient, R, was computed as the proportion of total variance in the between-person component. The R value was high for (β-thromboglobulin and tissue- plasminogen activator: 0.83 and 0.81, respectively; and intermediate for D-dimer and plasminogen activator inhibitor-1: 0.73 and 0.72, respectively. Protein S (total and free) and platelet factor 4 had low repeatability (R<0.50) derived mostly from “method” variability while low R value (0.03) for fibrinopeptide A was attributed to high “method” and “within-person” variability. Gender, age and the level of hemostatic factors did not influence the intraindividual variability.

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SERUM PROLACTINE LEVEL IN PATIENTS OF PSORIASIS VULGARIS AND ITS CORRELATION WITH DISEASE SEVERITY: A CASE-CONTROL STUDY

International Journal of Medical and Biomedical Studies ◽

10.32553/ijmbs.v3i6.303 ◽

2019 ◽

Vol 3 (6) ◽

Author(s):

Pawan Kumar Saini ◽

Devendra Yadav ◽

Rozy Badyal ◽

Suresh Jain ◽

Arti Singh ◽

...

Keyword(s):

Disease Severity ◽

Prolactin Level ◽

Case Control Study ◽

Statistical Significance ◽

Case Control ◽

Serum Prolactin ◽

P Value ◽

Serum Prolactin Level ◽

R Value ◽

Control Study

Background: Psoriasis is an autoimmune chronic inflammatory disorder affecting the skin mediated by T-lymphocytes resulting in production of cytokines which cause hyperproliferation of keratinocytes. Several factors and hormones like Prolactin have an action similar to these cytokines in promoting the multiplication of keratinocytes and other cells like lymphocytes and epithelial cells may have a role on the etiopathogenesis of psoriasis. Aim:-The aim of study is to compare the serum Prolactin levels in patients of psoriasis with a control group. Setting and study design: This is a case-control study conducted in the department of Dermatology, Venereology and Leprosy GMC, Kota over a period of 1year from July 2017 to June 2018 Material and method: The study included 100 cases of psoriasis (60 males and 40 females) and 100 controls similar for age and sex. Serum Prolactin levels were measured by ECLIA and results were obtained. Statistical analysis: Mean and standard deviation were calculated for each variable. Statistical significance of the results was analyzed using correlation analysis (Pearson correlation coefficient) and independent samples t-test. Statistical significance was assumed at p value<0.05. Result: Serum Prolactin level was significantly higher in cases of psoriasis compared to controls (p-value <0.001). PASI score and serum Prolactin levels were found to have a positive correlation (r value = 0.337; p-value: 0.001). No significant correlation was found between serum levels of Prolactin and duration of disease r value= -0.034, P value =0.733). Serum Prolactin level was higher in male patients compared to females patients. Conclusion:- High serum Prolactin may be a biological marker of disease severity in psoriasis and may have a role in the pathogenesis of psoriasis. Further studies with large sample size are required to confirm this hypothesis.

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Microstructure Evolution and Mechanical Properties of Wire-Brushed Surface and Roll-Bonded Interface of Aluminum Sheets

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2011.49.5.380 ◽

2011 ◽

Vol 49 (6) ◽

Keyword(s):

Mechanical Properties ◽

Microstructure Evolution ◽

Aluminum Sheets ◽

Bonded Interface

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Tris(dimethylphenylphosphine)ruthenium(0) Complexes of n4-Coordinated Polycyclic Aromatic Hydrocarbons

Australian Journal of Chemistry ◽

10.1071/ch00068 ◽

2000 ◽

Vol 53 (6) ◽

pp. 507 ◽

Cited By ~ 10

Author(s):

Martin A. Bennett ◽

Mark Bown ◽

David C. R. Hockless

Keyword(s):

Coordination Geometry ◽

Crystal Data ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

Tertiary Phosphine ◽

X Ray ◽

Tertiary Phosphines ◽

Polycyclic Aromatic ◽

R Value ◽

Axial Site

From the reaction of [Ru2Cl3(PMe2Ph)6] Cl with the appropriate radical anions, yellow complexes of general formula [Ru(PMe2Ph)3(η4-arene)] [arene = naphthalene (C10H8) (1), anthracene (C14H10) (2), and triphenylene (C18H12) (3)] have been isolated in poor yield and characterized by elemental analysis, n.m.r. (1H, 13C, 31P) spectroscopy and single-crystal X-ray diffraction. Crystal data: (1), monoclinic, C2/c, a 31.096(8), b 12.012(4), c 17.078(8) Å, β 104.41(3)˚, V 6178(4) Å3, ? 8, refined to final R value of 0.032 with use of 3641 reflections [I > 3σ(I)]; (2), monoclinic, C2/c, a 55.909(4), b 14.348(5), c 17.573(5) Å, β 105.41(1)˚, V 13590(6) Å3, Z 16 (two molecules per asymmetric unit), refined to final R value of 0.049 with use of 7770 reflections [I > 3σ(I)]; (3), mono-clinic, Pn, a 9.377(3), b 12.229(3), c 15.975(3) Å, β 103.51(2)˚, V 1781.2 (7) Å3, Z 2, refined to final R value of 0.026 with use of 2830 reflections [I > 3σ(I)]. In each case, coordination of the zerovalent metal fragment Ru(PMe2Ph)3 to the diene section of one of the terminal rings causes the aromatic molecule to be folded by c. 40˚ at the outer carbon atoms of the diene. The coordination geometry about ruthenium is approximately square pyramidal, with the diene and two tertiary phosphines in the equatorial plane and the remaining tertiary phosphine in the axial site.

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