Abstract: A turbine blade vibration damper is described. The damper has an axially-extending main body defining an inner surface and opposed damping surface. The main body also has an edge spanning from the inner surface to the damping surface and slotted apertures extending through the main body. The slotted apertures extend between the inner surface and damping surface. Adjacent pairs of slotted apertures have elongated shapes defining longitudinal axes that intersect at a point off the surface of the damper.

Abstract: Methods for forming optical fiber preforms with low-index trenches are disclosed. According to one embodiment, the method includes depositing silica-based glass soot on a bait rod to form a low-index trench region of the optical fiber preform. The silica-based glass soot is deposited such that the low-index trench region has a first density. Thereafter a barrier layer having a second density greater than the first density is formed around the low-index trench region. Therafter, an overclad region is deposited around the barrier layer. The bait rod is then removed from a central channel of the trench-overclad assembly. A separate core assembly is inserted into the central channel. A down-dopant gas is then directed through the central channel of the trench-overclad assembly as the trench-overclad assembly is heated to dope the low-index trench region. The barrier layer prevents diffusion of the down-dopant from the low-index trench region into the overclad region.

Abstract: A turbine blade vibration damper is described. The damper has an axially-extending main body defining an inner surface and opposed damping surface. The main body also has an edge spanning from the inner surface to the damping surface and slotted apertures extending through the main body. The slotted apertures extend between the inner surface and damping surface. Adjacent pairs of slotted apertures have elongated shapes defining longitudinal axes that intersect at a point off the surface of the damper.

Abstract: Methods for forming optical fiber preforms with low-index trenches are disclosed. According to one embodiment, the method includes depositing silica-based glass soot on a bait rod to form a low-index trench region of the optical fiber preform. The silica-based glass soot is deposited such that the low-index trench region has a first density. Thereafter a barrier layer having a second density greater than the first density is formed around the low-index trench region. Therafter, an overclad region is deposited around the barrier layer. The bait rod is then removed from a central channel of the trench-overclad assembly. A separate core assembly is inserted into the central channel. A down-dopant gas is then directed through the central channel of the trench-overclad assembly as the trench-overclad assembly is heated to dope the low-index trench region. The barrier layer prevents diffusion of the down-dopant from the low-index trench region into the overclad region.

Abstract: According to one example of the invention an optical fiber comprises: (i) silica based, rare earth doped core having a first index of refraction n1; (ii) at least one silica based cladding surrounding the core and having a second index of refraction n2, such that n1>n2; wherein at least one of the core or cladding is doped with Al2O3, such that the ratio of max wt % to min wt % of Al2O3 concentration is less than 2:1.

Abstract: According to one example of the invention an optical fiber comprises: (i) silica based, rare earth doped core having a first index of refraction n1; (ii) at least one silica based cladding surrounding the core and having a second index of refraction n2, such that n1>n2; wherein at least one of the core or cladding is doped with Al2O3, such that the ratio of max wt % to min wt % of Al2O3 concentration is less than 2:1

Abstract: A float attachment for hydraulic systems, such as those used in controlling dozer blades, front end loaders, snow plow blades and the like where the blade, bucket or the like is controlled with a double acting cylinder. The float apparatus includes a float cylinder that is connected in parallel with the double acting cylinder. The float cylinder contains a free floating piston and may have, at the end connected to the lowering end of the hydraulic cylinder, a check valve preventing flow into the float cylinder and a pressure relief valve by-passing the check valve. The relief valve controls the pressure of the blade on the ground and allows the blade to float if that pressure is exceeded.

Abstract: According to one example of the invention an optical fiber comprises: (i) silica based, rare earth doped core having a first index of refraction n1; (ii) at least one silica based cladding surrounding the core and having a second index of refraction n2, such that n1>n2; wherein at least one of the core or cladding is doped with Al2O3, such that the ratio of max wt % to min wt % of Al2O3 concentration is less than 2:1.