Comparaison des formes de Seifert et des fonctions zêta de Denef-Loeser des germes de courbe plane à singularité isolée

We show that the topological type of a plane curve germ with isolated singularity is not determined by its integral Seifert form and Denef-Loeser zeta function. Furthermore, the integral Seifert form of such a germ is not determined by its Denef-Loeser zeta function

A dynamic modelling of safety nets

The nonlinear dynamic modelling of safety net systems is approached at different scales. For this purpose, the fundamental rope dynamic tests are the reference for two basic tools. One hand an anaytical bidimensional model with explicit geometrical nonlinearity and bilnear material law is proposed for preliminary design. On the other hand, a nonlinear explicit finite element is defined for numerical modelling of net systems. Semi-scale and full scale dynamic tests are performed to validate complete finite element models, suitable for global qualification of safety systems. The direct applications of these tools deal with explicit certification of safety systems for high-speed sport, such as downhill competitions

Low-loss singlemode PECVD silicon nitride photonic wire waveguides for 532-900 nm wavelength window fabricated within a CMOS pilot line

PECVD silicon nitride photonic wire waveguides have been fabricated in a CMOS pilot line. Both clad and unclad single mode wire waveguides were measured at lambda = 532, 780, and 900 nm, respectively. The dependence of loss on wire width, wavelength, and cladding is discussed in detail. Cladded multimode and singlemode waveguides show a loss well below 1 dB/cm in the 532-900 nm wavelength range. For singlemode unclad waveguides, losses < 1 dB/cm were achieved at lambda = 900 nm, whereas losses were measured in the range of 1-3 dB/cm for lambda = 780 and 532 nm, respectively

Characterization of PECVD Silicon Nitride Photonic Components at 532 and 900 nm Wavelength

Low temperature PECVD silicon nitride photonic waveguides have been fabricated by both electron beam lithography and 200 mm DUV lithography. Propagation losses and bend losses were both measured at 532 and 900 nm wavelength, revealing sub 1dB/cm propagation losses for cladded waveguides at both wavelengths for single mode operation. Without cladding, propagation losses were measured to be in the 1-3 dB range for 532 nm and remain below 1 dB/cm for 900 nm for single mode waveguides. Bend losses were measured for 532 nm and were well below 0.1 dB per 90 degree bend for radii larger than 10 mu m

Effect of xylopic acid on alloxan-induced diabetic neuropathy in rats

Background: Neuropathic pain is a very disturbing condition commonly found in diabetic patients. This study investigated xylopic acid (XA), the major constituent of Xylopia aethiopica in diabetic neuropathy as well as established possible toxicity of the compound on some selected tissues.Methods: Diabetes was induced in six groups of male rats with 120 mg/kg alloxan monohydrate. Diabetes was confirmed as a blood glucose level >15 mmol/dl. Neuropathic pain was confirmed on day three post-diabetes induction and treatment with 10 mg/kg, 30 mg/kg or 100 mg/kg xylopic acid, 10 mg/kg glibenclamide, 10 mg/kg morphine, and 10 ml/kg normal saline were initiated and continued for the next 15 days. The effects of the treatments on cold allodynia (cold water at 4°C) and thermal hyperalgesia (hot water at 55 ± 1°C) were evaluated within the duration of treatments. Histology of the liver and kidney, as well as haematological, serum biochemical, and semen analyses, were done after the fifteenth day of the experiment.Results: Xylopic acid produced significant anti-hyperglycaemic and analgesic effects in the cold allodynia and thermal hyperalgesia tests. Sperm motility, viability and count were significantly restored at 10 mg/kg XA as compared higher doses and negative control. The outcome of haematological analysis revealed a protective effect of XA although histological damage liver and kidney due to alloxan treatment was observable.Conclusions: Xylopic acid ameliorates diabetic neuropathy in rats and does not exert detrimental effects at low doses