Till now, most studies of the Blood Oxygen Level-Dependent (BOLD) response to interictal epileptic discharges (IED) have assumed that its time course matches closely to that of brief physiological stimuli, commonly called the canonical event-related haemodynamic response function (canonical HRF). Analyses based on that assumption have produced significant response patterns that are generally concordant with prior electroclinical data. In this work, we used a more flexible model of the event-related response, a Fourier basis set, to investigate the presence of other responses in relation to individual IED in 30 experiments in patients with focal epilepsy. We found significant responses that had a noncanonical time course in 37% of cases, compared with 40% for the conventional, canonical HRF-based approach. In two cases, the Fourier analysis suggested activations where the conventional model did not. The noncanonical activations were almost always remote from the presumed generator of epileptiform activity. In the majority of cases with noncanonical responses, the noncanonical responses in single-voxel clusters were suggestive of artifacts. We did not find evidence for IED-related noncanonical HRFs arising from areas of pathology, suggesting that the BOLD response to IED is primarily canonical. Noncanonical responses may represent a number of phenomena, including artefacts and propagated epileptiform activity.

/pdf/noncanonical-spike-related-bold-responses-in-focal-epilepsy-4gbe8s586e.pdf

Noncanonical spike-related BOLD responses in focal epilepsy

Disclosed is a novel heat-resistant superalloy for turbine disks having a chemical composition consisting of, in mass%, 19.5-55% of cobalt, 2-25% of chromium, 0.2-7% of aluminum, 3-15% of titanium and the balance of nickel and inevitable impurities.

Heat-resistant superalloy

There are a multiplicity of methods of making through-holes. In particular in the production of a multiplicity of film-cooling holes, as in gas turbine blades or combustion chamber elements, small time advantages are also important when making a hole. The method according to the invention, to make the hole close to the final contour in each case in sections in a top and a bottom region in order to then produce the final contour with other laser parameters, achieves time advantages.

Method For Producing a Hole

A welding method for welding workpieces made of highly heat-resistant superalloys is provided. The method includes generating a heat input zone on the workpiece surface by means of a heat source, feeding welding filler material into the heat input zone by means of a feeding device, and generating a relative motion between the heat source and the feeding device on one hand and the workpiece surface on the other hand by means of a conveying device. Furthermore, according to the welding method, the mass feed rate is ≦350 mg/min.

Method for welding workpieces made of highly heat-resistant superalloys, including a particular mass feed rate of the welding filler material

A core for casting a metal part having a body with solid portions spaced apart by hollow portions The body includes at least one support element extending between adjacent solid portions The support element provides stiffness and strength for the casting core during the casting process The support element has an optimized shape to prevent the core from fracturing during the casting process and to minimize operating stress in the metal part around the area formed by the support element

Apparatus and method for reducing operating stress in a turbine blade and the like

Component made from a nickel-based super alloy contains (in wt.%) 9-11 chromium (Cr),3-5 tungsten (W), 0.5-2.5 molybdenum (Mo), 3-3.5 aluminium (Al), 3-5 titanium (Ti), 3-7 tantalum (Ta), 0-12 cobalt (Co), 0-1 niobium (Nb), 0-2 hafnium (Hf), 0-1 zirconium (Zr), 0-0.05 boron (B), 0-0.2 carbon (C), 1-5 rhenium (Re), 0.1-5 ruthenium (Ru), balance nickel (Ni) and impurities. Preferably the alloy contains at least 2 wt.% Re and a maximum of 3 wt.% Ru. The component is a monocrystalline structure having an isotropic distribution of the orientation of the grain structure.

High temperature resistant part, made of single-crystal or polycrystalline nickel-base superalloy

In a method for removing tin from a surface and/or from a region close to the surface of a component part, the component part has a concentrated aqueous sodium hydroxide or concentrated hydrochloric acid flowing in contact with it at a temperature which is distinctly higher than room temperature. Preferably, the temperature is approximately 220° C., and the component part is moreover subjected to a positive pressure of 5.5 bar. The method is suitable for a component part fabricated through the use of unidirectional solidification and liquid-metal cooling, in particular a turbine blade.

Method for removing tin

The invention relates to a turbine blade (1), especially a gas turbine blade. The inventive turbine blade extends along a main axis (2) from a base area (3) to a top area (5), via a flat blade area (4). The blade has a hollow space (6) in the area of the flat blade part (4) which is surrounded at least in areas by a blade wall (7). Said blade wall (7) is of a low thickness and has a metallic material (8) with a low average particle size. The invention also relates to a method for producing a turbine blade (1).

Turbine blade and method for producing a turbine blade

The turbine blade extends along a main axis (2) from a foot region (3) to a head region (5), with the intermediate blade region (4) incorporating at least one hollow space (6), enclosed by a turbine wall section with a reduced thickness. The turbine wall is made of a metallic material (8) with a lesser mean particle size than a conventional cast metal. The thickness of the turbine wall may reduce continuously in the direction of the head region.

Turbine blade and method of fabrication of a turbine blade

The invention relates to a process for removing tin from a surface and/or the region close to the surface of a component in which the component is subjected to a flow of concentrated caustic soda or hydrochloric acid at a temperature considerably above ambient temperature. The temperature is preferably about 220 °C and the component is also subjected to an overpressure of 5.5 bar. The process is suitable for a component produced by directional solidification and liquid metal cooling, especially a turbine blade.

Winfried Esser

Papers

High temperature resistant part, made of single-crystal or polycrystalline nickel-base superalloy

Method for removing tin

Turbine blade and method for producing a turbine blade

Turbine blade and method of fabrication of a turbine blade

Process for removing tin