Electrical and Thermal Conductivity of Complex-Shaped Contact Spots

This paper explores the electrical and thermal conductivity of complex contact spots on the surface of a half-space. Employing an in-house Fast Boundary Element Method implementation, various complex geometries were studied. Our investigation begins with annulus contact spots to assess the impact of connectedness. We then study shape effects on "multi-petal" spots exhibiting dihedral symmetry, resembling flowers, stars, and gears. The analysis culminates with self-affine shapes, representing a multi-scale generalization of the multi-petal forms. In each case, we introduce appropriate normalizations and develop phenomenological models. For multi-petal shapes, our model relies on a single geometric parameter: the normalized number of "petals". This approach inspired the form of the phenomenological model for self-affine spots, which maintains physical consistency and relies on four geometric characteristics: standard deviation, second spectral moment, Nayak parameter, and Hurst exponent. As a by product, these models enabled us to suggest flux estimations for an infinite number of petals and the fractal limit. This study represents an initial step into understanding the conductivity of complex contact interfaces, which commonly occur in the contact of rough surfaces.Comment: 40 pages, 28 figure

La prochaine fois on ira chez Courbet ! Chronique de la justice ordinaire

Pour la plupart, nous ne connaissons de la justice et du métier d\u27avocat que des clichés qui ont la vie dure ; entre l\u27image d\u27Epinal de l\u27avocat capable de défendre le pire criminel sans l\u27ombre d\u27une hésitation et le juriste assoiffé de gloire médiatique et politique, nous ne voyons l\u27institution judiciaire qu\u27à travers le prisme déformé des feuilletons américains. Mais qu\u27en est-il du quotidien, de cette justice ordinaire à laquelle un jour ou l\u27autre, chacun peut être confronté ? Dans ces chroniques de la justice ordinaire, Antoine Béguin prend le contrepied des idées reçues et nous fait découvrir son métier et le petit monde de la "justice ordinaire ", loin des clichés. Fruit de son expérience personnelle et des histoires racontées par ses confrères, l\u27auteur nous invite dans cet univers, au travers d\u27anecdotes ou de portraits parfois féroces, mais toujours empreints d\u27humanité. Entre les histoires de voisins qui se détestent, le braconnier rétif à toute idée de sanction, le vieux comte qui défie la Justice pour une question d\u27honneur, la jeune femme "qui ne sait pas dire non", l\u27agriculteur victime d\u27une femme "fatale", ce couple et son chien dont le handicap déclenchera le rire, ou encore l\u27avocat resté enfermé la nuit dans un palais de justice... Toutes ces histoires et bien d\u27autres sont le juste reflet de la réalité du métier et de l\u27état de notre Justice, loin, très loin des idées préconçues. Au-delà de l\u27humour omniprésent dans ces chroniques, le lecteur pourra réaliser qu\u27il n\u27est pas facile pour l\u27avocat d\u27être à la fois le juriste, le confident, l\u27autorité nécessaire attendus de tous ; il touchera au plus près la passion qui anime ces hommes de l\u27art

Identification of N- and C-terminal corticotropin peptides in the Mr 80 000 form of neurophysin

AbstractThe 125I-labeled Mr 80 000 form of neurophysin has been purified from bovine neurohypophysi. Tryptic digests of this species were analyzed, prior to or after treatment with carboxypeptidase B, by high-pressure liquid chromatography followed by isoelectric focusing and the fragments compared with those generated by a similar treatment of reference bovine 1–39 adrenocorticotropin. The ACTH peptides 22–39 and 1–8, as well as the 1–7 derivative of the latter were identified by those two independent criteria. This provides chemical evidence supporting the hypothesis [8] that high Mr neurophysin may contain the sequence of ACTH

Cosmological time versus CMC time I: Flat spacetimes

This paper gives a new proof that maximal, globally hyperbolic, flat spacetimes of dimension $n\geq 3$ with compact Cauchy hypersurfaces are globally foliated by Cauchy hypersurfaces of constant mean curvature, and that such spacetimes admit a globally defined constant mean curvature time function precisely when they are causally incomplete. The proof, which is based on using the level sets of the cosmological time function as barriers, is conceptually simple and will provide the basis for future work on constant mean curvature time functions in general constant curvature spacetimes, as well for an analysis of the asymptotics of constant mean foliations

Defective iron supply for erythropoiesis and adequate endogenous erythropoietin production in the anemia associated with systemic-onset juvenile chronic arthritis.

peer reviewedSystemic-onset juvenile chronic arthritis (SoJCA) is associated with high levels of circulating interleukin-6 (IL-6) and is frequently complicated by severe microcytic anemia whose pathogenesis is unclear. Therefore, we studied 20 consecutive SoJCA patients with hemoglobin (Hb) levels <12 g/dL, evaluating erythroid progenitor proliferation, endogenous erythropoietin production, body iron status, and iron supply for erythropoiesis. Hb concentrations ranged from 6.5 to 11.9 g/dL. Hb level was directly related to mean corpuscular volume (r = .82, P < .001) and inversely related to circulating transferrin receptor (r = -.81, P < .001) suggesting that the severity of anemia was directly proportional to the degree of iron-deficient erythropoiesis. Serum ferritin ranged from 18 to 1,660 microgram/L and was unrelated to Hb level. Bone marrow iron stores wore markedly reduced in the three children investigated, and they also showed increased serum transferrin receptor and normal-to-high serum ferritin. All 20 patients had elevated IL-6 levels and normal in vitro growth of erythroid progenitors. Endogenous erythropoietin (epo) production was appropriate for the degree of anemia as judged by both the observed to predicted log (serum epo) ratio 10.95 +/- 0.12) and a comparison of the serum epo-Hb regression found in these subjects with that of thalassemia patients. Multiple regression analysis showed that serum transferrin receptor was the parameter most closely related to hemoglobin concentration: variation in circulating transferrin receptor explained 61% of the variation in Hb level (P < .001). In 10 severely anemic patients, amelioration of anemia following intravenous iron administration resulted in normalization of serum transferrin receptor. Defective iron supply to the erythron rather than blunted epo production is the major cause of the microcytic anemia associated with SoJCA. A true body-iron deficiency caused by decreased iron absorption likely complicates long-lasting inflammation in the most anemic children, and this can be recognized by high serum transferrin receptor levels. Although oral iron is of no benefit, intravenous iron saccharate is a safe and effective means for improving iron availability for erythropoiesis and correcting this anemia. Thus, while chronically high endogenous IL-6 levels do not appear to blunt epo production, they are probably responsible for the observed abnormalities in iron metabolism. Anemia of chronic disease encompasses a variety of anemic conditions whose peculiar features may specifically correlate with the type of cytokine(s) predominantly released