In Situ Digital Image Correlation Observations of Laser Forming

In this study experimental and modelling methods are used to examine the microstructural and bending responses of laser-formed commercially pure titanium grade 2. The in situ bending angle response is measured for different processing parameters utilizing 3D digital image correlation. The microstructural changes are observed using electron backscatter diffraction. Finite element modelling is used to analyse the heat transfer and temperature field inside the material. It has been proven that the laser bending process is not only controlled by processing parameters such as laser power and laser beam scanning speed, but also by surface absorption. Grain size appears to have no influence on the final bending angle, however, sandblasted samples showed a considerably higher final bending angle. Experimental and simulation results suggest that the laser power has a larger influence on the final bending angle than that of the laser transverse speed. The microstructure of the laser heat-affected zone consists of small refined grains at the top layer followed by large elongated grains. Deformation mechanisms such as slip and twinning were observed in the heat-affected zone, where their distribution depends on particular processing parameters

Взаємозв’язок великих кондратьєвських циклів розвитку економіки і системних світових конфліктів

Однією з найважливіших проблем, що постала перед сучасною наукою у зв’язку із стрімким розгортанням глобальної економічної кризи, загостренням світових конфліктів, є вироблення науково обґрунтованих «метричних» експрес прогнозів розвитку суспільства на ближчу і далеку перспективу

Hemodynamic and biochemical effects of the AT1 receptor antagonist irbesartan in hypertension

We studied the hemodynamic, neurohumoral, and biochemical effects of the novel angiotensin type 1 (AT1) receptor antagonist irbesartan in 86 untreated patients with essential hypertension on a normal sodium diet. According to a double-blind parallel group trial, patients were randomized to a once-daily oral dose of the AT1 receptor antagonist (1, 25, or 100 mg) or placebo after a placebo run-in period of 3 weeks. Randomization medication was given for 1 week. Compared with placebo, 24-hour ambulatory blood pressure did not change with the 1-mg dose, and it fell (mean and 95% confidence interval) by 7.0 (4.2-9.8)/6.1 (3.9-8.1) mm Hg with the 25-mg dose and by 12.1 (8.1-16.2)/7.2 (4.9-9.4) mm Hg with the 100-mg dose. Heart rate did not change during either dose. With the 25-mg dose, the antihypertensive effect was attenuated during the second half of the recording, and wi

Professionele leergemeenschappen : zo werkt het (goed)

Professionele leergemeenschappen (PLG’s) waarin docenten samenwerken blijken een positieve bijdrage te leveren aan de kwaliteit van het onderwijs en werkplezier van docenten. In een vijfjarig onderzoek dat is uitgevoerd door onderzoekers van drie universiteiten (Leiden, Rotterdam, Eindhoven) is op een unieke manier gekeken naar hoe je die PLG’s het beste kunt laten werken. Er is gekeken naar hoe PLG’s ondersteund kunnen worden, waarom docenten eraan deelnemen, wat het oplevert aan veranderingen bij docenten en in de klas. Ook is gedetailleerd gekeken naar hoe het samenwerken tijdens bijeenkomsten nu echt gaat, hoe gesprekken zich ontwikkelen over de tijd, en hoe je die gesprekken het beste kunt organiseren