Extended plasticity in commercial-purity zinc

90% rolling-reduction of annealed commercial-purity zinc sheet (grain size 100 - 150 μ) results in the fragmentation of the large grains into, finally, stable micro-grains, 1 - 211 in diameter. The stability of the micro-grains is due to the presence of soluble and insoluble impurities which prevent recrystallization. This micro-grain material is strain-rate sensitive, and elongations of 200% have been obtained at room temperature. Although this as-rolled, 90% reduction zinc sheet is not super-plastic according to the current definition, its behaviour has led to the coining of the phase 'extended plasticity'. Evidence of grain-boundary sliding is found on examination of the surface by scanning electron microscopy, while the examination of thin foils and activation energy measurements support the dynamic softening (recovery) theory; thus, both these mechanisms must be operating, to a greater or less extent, to confer on this material the observe mechanical behaviour. It is finally concluded that it is dangerous to draw conclusions regarding the mechanism of plastic deformation from surface observations alone

Increased plasma levels of metalloproteinase-9 are associated with abdominal aortic aneurysms

AbstractPurpose: Previous investigators have identified disease-specific elevations of metalloelastase-9 (MMP-9) in aneurysm tissue biopsies. We hypothesized that circulating MMP-9 might also be elevated in patients with aneurysms. The purpose of this study was to compare plasma and aortic tissue MMP-9 levels in patients with infrarenal aneurysms (AAAs), patients with symptomatic aortoiliac occlusive disease (AOD), and healthy patients. Methods: A sandwich enzyme-linked immunosorbent assay was used to measure plasma MMP-9 in patients with AAA (n = 22; mean age, 72.7 years), with AOD (n = 9; mean age, 60.5 years), and without disease (n = 8; mean age, 35.3 years). The MMP-9 levels also were measured in 48-hour supernatants of organ culture tissue explants from patients with AAA (n = 10; mean age, 66.2 years) and AOD (n = 5; mean age, 50.4 years) and organ donors (n = 7; mean age, 48.1 years). The results were reported as the mean ± the standard error of the mean and analyzed with analysis of variance with multivariate regression. Results: The plasma MMP-9 levels were significantly higher in the patients with AAA (85.66 ng/mL ± 11.64) than in the patients with AOD (25.75 ng/mL ± 4.159; P < .001) or the healthy patients (13.16 ng/mL ± 1.94; P < .001). No significant difference in plasma MMP-9 levels between patients with AOD and healthy patients was identified. The patients with multiple aneurysms had significantly higher levels of plasma MMP-9 than did the patients with an isolated AAA (134.68 ng/mL ± 17.5 vs 71.03 ng/mL ± 10.7; P < .04). In organ culture, AAA and AOD tissue explants produced significantly higher levels of MMP-9 (3218.5 ng/gm ± 1115.2 and 1283.1 ng/gm ± 310.6 aortic tissue) than did disease-free explants (6.14 ng/gm ± 2.3 aortic tissue; P < .0001). No significant difference in MMP-9 production between AAA and AOD explants was identified. Conclusion: Plasma MMP-9 levels are significantly higher in patients with AAA than in patients with AOD or in healthy volunteers. The patients with multiple aneurysms have higher levels than those patients with an isolated AAA. Organ culture studies suggest that diseased aortic tissue is the source of MMP-9. (J Vasc Surg 1999;29:122-9.

Preliminary data on boulders at station 6, Apollo 17 landing site

A cluster of boulders at Station 6 (Apollo 17 landing site) consists of breccias derived from the North Massif. Three preliminary lithologic units were established, on the basis of photogeologic interpretations; all lithologies identified photogeologically were sampled. Breccia clasts and matrices studied petrographically and chemically fall into two groups by modal mineralogy: (1) low-K Fra Mauro or high basalt composition, consisting of 50-60% modal feldspar, approximately 45% orthopyroxene and 1-7% Fe-Ti oxide; (2) clasts consisting of highland basalt composition, consisting of 70% feldspar, 30% orthopyroxene and olivine and a trace of Fe-Ti oxide

Geometric Exponents, SLE and Logarithmic Minimal Models

In statistical mechanics, observables are usually related to local degrees of freedom such as the Q < 4 distinct states of the Q-state Potts models or the heights of the restricted solid-on-solid models. In the continuum scaling limit, these models are described by rational conformal field theories, namely the minimal models M(p,p') for suitable p, p'. More generally, as in stochastic Loewner evolution (SLE_kappa), one can consider observables related to nonlocal degrees of freedom such as paths or boundaries of clusters. This leads to fractal dimensions or geometric exponents related to values of conformal dimensions not found among the finite sets of values allowed by the rational minimal models. Working in the context of a loop gas with loop fugacity beta = -2 cos(4 pi/kappa), we use Monte Carlo simulations to measure the fractal dimensions of various geometric objects such as paths and the generalizations of cluster mass, cluster hull, external perimeter and red bonds. Specializing to the case where the SLE parameter kappa = 4p'/p is rational with p < p', we argue that the geometric exponents are related to conformal dimensions found in the infinitely extended Kac tables of the logarithmic minimal models LM(p,p'). These theories describe lattice systems with nonlocal degrees of freedom. We present results for critical dense polymers LM(1,2), critical percolation LM(2,3), the logarithmic Ising model LM(3,4), the logarithmic tricritical Ising model LM(4,5) as well as LM(3,5). Our results are compared with rigourous results from SLE_kappa, with predictions from theoretical physics and with other numerical experiments. Throughout, we emphasize the relationships between SLE_kappa, geometric exponents and the conformal dimensions of the underlying CFTs.Comment: Added reference

Evaluation of Forage Yield and Quality of Low-Lignin Alfalfa in Monoculture and Binary Mixtures in the Dark Brown Soil Zone of Saskatchewan

Non-Peer ReviewedThe objective of this study was to compare low-lignin Hi-Gest® 360 alfalfa to a conventional legume in both monoculture and binary mixtures. Two varieties of alfalfa (monoculture) [Medicago sativa L. cv. AC Grazeland (Grazeland) and Hi-Gest 360 (Hi-Gest] or in mixture (binary) with AC Success hybrid bromegrass (HB) (Grazeland+HB and Hi-Gest+HB) were grown at a Dark Brown soil zone site (52o07′ N, 106o 38′ W) in Saskatchewan and harvested at 3 maturity stages (stage) of alfalfa [1 = 10% bloom; 2 = 40% bloom; and 3 = 100% bloom)] over 2 yr. Forage was harvested on June 21, June 25, and June 29 2018, and July 8, July 12, and July 16 2019. All plots were established in a randomized complete block design with four replications using forages as treatments. Plot size was 6.2 m × 1.2 m (7.44 m2) with 4 rows and total of 48 plots. Dry matter yield (DMY; 2-yr) and nutritive value (1-yr) of forages were determined. Results indicate that monoculture Hi-Gest alfalfa had greater (P 0.05) for forage quantity and quality. However, forages at maturity stage 3 had greater DMY (1058 vs. 783 kg), but lower CP (17.6 vs. 19.6%) and IVNDFD48 (37.1 vs. 42.3%) than those at maturity stage 1. The sugar content of forages linearly increased (P 0.05) observed between AC Grazeland+HB and Hi-Gest+HB mixtures for DMY or quality profiles. Monoculture had greater CP (18.5 vs. 12.0 %), ADFCP (2.5 vs. 1.5%), lignin (6.9 vs. 4.7%), fat (3.0 vs. 2.6%), RFV (174.8 vs. 91.8), NEm (1.6 vs. 1.3 Mcal/kg), NEg (0.96 vs. 0.77 Mcal/kg), but lower DMY (920 vs. 3343 kg/ha), ADF (27.4 vs. 35.9%), NDF (36.3 vs. 61.9%), starch (0.41 vs. 0.82%), and IVNDFD48 (39.2 vs. 50.7%), compared to binary mixtures. Results suggest that Hi-Gest alfalfa as a monoculture yielded less than AC Grazeland, however Hi-Gest monoculture had higher nutritive value than AC Grazeland, but was similar for yield and quality in mixture, suggesting Hi-Gest 360 alfalfa is a viable alternative legume for Dark Brown soil zone of Saskatchewan

W-Extended Fusion Algebra of Critical Percolation

Two-dimensional critical percolation is the member LM(2,3) of the infinite series of Yang-Baxter integrable logarithmic minimal models LM(p,p'). We consider the continuum scaling limit of this lattice model as a `rational' logarithmic conformal field theory with extended W=W_{2,3} symmetry and use a lattice approach on a strip to study the fundamental fusion rules in this extended picture. We find that the representation content of the ensuing closed fusion algebra contains 26 W-indecomposable representations with 8 rank-1 representations, 14 rank-2 representations and 4 rank-3 representations. We identify these representations with suitable limits of Yang-Baxter integrable boundary conditions on the lattice and obtain their associated W-extended characters. The latter decompose as finite non-negative sums of W-irreducible characters of which 13 are required. Implementation of fusion on the lattice allows us to read off the fusion rules governing the fusion algebra of the 26 representations and to construct an explicit Cayley table. The closure of these representations among themselves under fusion is remarkable confirmation of the proposed extended symmetry.Comment: 30 page

A longitudinal, observational study examining the relationships of patient satisfaction with services and mental well-being to their clinical course in young people with Type 1 diabetes mellitus during transition from child to adult health services

AIM: We hypothesized that participant well-being and satisfaction with services would be positively associated with a satisfactory clinical course during transition from child to adult health care. METHODS: Some 150 young people with Type 1 diabetes mellitus from five diabetes units in England were recruited to a longitudinal study of transition. Each young person was visited at home four times by a research assistant; each visit was 1 year apart. Satisfaction with services (Mind the Gap; MTG) and mental well-being (Warwick-Edinburgh Mental Well-being Scale; WEMWBS) were captured. Change in HbA1c , episodes of ketoacidosis, clinic and retinal screening attendance were used to assess clinical course. In total, 108 of 150 (72%) young people had sufficient data for analysis at visit 4. RESULTS: Mean age at entry was 16 years. By visit 4, 81.5% had left paediatric healthcare services. Median HbA1c increased significantly (P = 0.01) from 69 mmol/mol (8.5%) at baseline to 75 mmol/mol (9.0%) at visit 4. WEMWBS scores were comparable with those in the general population at baseline and were stable over the study period. MTG scores were also stable. By visit 4, some 32 individuals had a 'satisfactory' and 76 a 'suboptimal' clinical course. There were no significant differences in average WEMWBS and MTG scores between the clinical course groups (P = 0.96, 0.52 respectively); nor was there a significant difference in transfer status between the clinical course groups. CONCLUSIONS: The well-being of young people with diabetes and their satisfaction with transition services are not closely related to their clinical course. Investigating whether innovative psycho-educational interventions can improve the clinical course is a research priority

Fusion algebra of critical percolation

We present an explicit conjecture for the chiral fusion algebra of critical percolation considering Virasoro representations with no enlarged or extended symmetry algebra. The representations we take to generate fusion are countably infinite in number. The ensuing fusion rules are quasi-rational in the sense that the fusion of a finite number of these representations decomposes into a finite direct sum of these representations. The fusion rules are commutative, associative and exhibit an sl(2) structure. They involve representations which we call Kac representations of which some are reducible yet indecomposable representations of rank 1. In particular, the identity of the fusion algebra is a reducible yet indecomposable Kac representation of rank 1. We make detailed comparisons of our fusion rules with the recent results of Eberle-Flohr and Read-Saleur. Notably, in agreement with Eberle-Flohr, we find the appearance of indecomposable representations of rank 3. Our fusion rules are supported by extensive numerical studies of an integrable lattice model of critical percolation. Details of our lattice findings and numerical results will be presented elsewhere.Comment: 12 pages, v2: comments and references adde