Solute carbon and nitrogen in the ferrite after continuous annealing of low carbon low aluminium steels

Low N_sol levels not only require reduced N contents (≤ 20 ppm) in steel but also Al/N ratios higher than 5 and C contents higher than 0.025% because of the synergic effect between N and C precipitations; scavenging of Al on nitrogen is far from complete even in steels coiled at 750°C. Low C_sol levels are achieved either at very lowC contents (C ≤ 0.003%) or at C contents higher than 0.025%. Due to high C_sol, carbon aging is expected in steels coiled at 750°C. Softer, bake hardenable steels with good aging resistance will be obtained in the range 0.025–0.030 % C independently of the coiling temperature. C supersaturation of the ferrite is reduced at higher cooling rates after continuous annealing. Changes in C and N supersaturation according to the steel composition and the continuous annealing process are explained, taking into account the carbides morphology and the annealing conditions.     

The condensation of lignin model compounds with hexamethylene diisocyanate

Analysis by infrared and nuclear magnetic resonance spectroscopy, differential scanning calorimetry and thermogravimetric estimation of the condensation products of hexamethylene diisocyanate and certain lignin model compounds bearing a free phenolic hydroxyl (prepared both in the melt at 100°C and in refluxing methylene chloride solution) shows that stoichiometric proportions give high yields of bisurethanes. These products decompose below 160°C to regenerate the starting materials.     

Adhesion improvement of polyester/aluminium interface by plasma polymerization pretreatments

Plasma polymerizations (PP) of acrylic acid (AA) and methacrylic acid (MAA) on polyester were used to improve the adhesion of the polyester/aluminium interface. It was found that this adhesion measured by the peel test method is 5-10 times higher than in the case of untreated polyester. Comparisons of the X-ray photoelectron spectroscopy (XPS) results obtained from the treated polyester, the untreated polyester and the reference spectra of poly(acrylic acid) cast from H₂O suggest that the observed adhesion improvement can be explained in terms of the formation of new functionalities at the polyester surface.     

Evidence that type III iodothyronine deiodinase in rat astrocyte is a selenoprotein

A type III iodothyronine deiodinase (D-III) that inactivates thyroid hormones has been recently cloned and identified as a selenoprotein in neonatal rat skin. However, selenium (Se) deficiency does not affect the D-III activity in the rat placenta and decreases the D-III in the rat brain only slightly. This study examines the effect of Se on the D-III activity in cultures of rat brain astrocytes. Astrocytes were depleted in Se by maintaining them in Se-free chemically defined medium for 7 days. These conditions decreased the activity of a recognized selenoprotein, glutathione peroxidase, 3-10-fold. D-III activity induced by 12-0-tetradecanoylphorbol-13-acetate (TPA) was also decreased 2-6-fold. Addition of 30 nM Se to the culture medium caused a rapid increase in TPA-induced D-III activity visible within 1 h. This Se effect was maximal at 3 h (4-fold increase) and dose-dependent. Se also increased the induction of D-III by acidic Fibroblast Growth Factor, 8-bromo-cAMP, T4, or retinoic acid. Cycloheximide blocked the effect of Se on TPA-induced D-III activity, whereas actinomycin D did not. Thus the rapid effect of Se does not require messenger RNA synthesis but requires protein synthesis. We conclude that the D-III in astrocytes is probably a selenoprotein.     

A tabu search heuristic for the routing and wavelength assignment problem in optical networks

This letter proposes a tabu search heuristic for solving the routing and wavelength assignment (RWA) problem in optical WDM networks, considering the wavelength continuity constraint and a given set of connections to satisfy. For a number of available wavelengths on each link, this algorithm attempts to maximize the number of routed connections. The algorithm has been implemented and tested on NSFNET and EONNET networks and comparisons have been done with other algorithms in terms of the blocking rate. Generally, the results obtained with our tabu search heuristic are better than those provided by these algorithms.     

Mental rotation and the identification of disoriented objects.

Compared the effects of stimulus orientation among 30 undergraduates across an object-naming task and a left–right decision task using the same line-drawing stimuli in a within-Ss design. Stimuli were shown at various orientations by rotating the objects in the picture plane. The effects of orientation on object-naming were different from those observed in the left–right task. Results suggest that 2 mechanisms are involved in the naming task, one of which is more sensitive to orientation effects. Results also suggest the possibility that one of the mechanisms underlying the effects of orientation on object-naming time may be mental motion. A list of the objects used in the experiment is appended. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reformulated Nyquist criterion for discrete-time systems

A reformulated Nyquist criterion for discrete time systems is generalized in two ways. First, the criterion is cast in a form which allows the user to assess, directly from the mapping, the range of a parameter that yields stability. Second, the criterion is extended to apply to the case where poles at z=∞ occur in the function being mapped