Methods of manufacturing or repairing a turbine blade or vane are described. The airfoil portions of these turbine components are typically manufactured by casting in a ceramic mold, and a surface made up of the cast airfoil and at the least the ceramic core serves as a build surface for a subsequent process of additively manufacturing the tip portions. The build surface is created by removing a top portion of the airfoil and the core, or by placing an ultra-thin shim on top of the airfoil and the core. The overhang projected by the shim is subsequently removed. These methods are not limited to turbine engine applications, but can be applied to any metallic object that can benefit from casting and additive manufacturing processes. The present disclosure also relates to finished and intermediate products prepared by these methods.

Filled carbon nanotubes (CNTs) and methods of synthesizing the same are provided. An in situ chemical vapor deposition technique can be used to synthesize CNTs filled with metal sulfide nanowires. The CNTs can be completely and continuously filled with the metal sulfide fillers up to several micrometers in length. The filled CNTs can be easily collected from the substrates used for synthesis using a simple ultrasonication method.

Filled carbon nanotubes (CNTs) and methods of synthesizing the same are provided. An in situ chemical vapor deposition technique can be used to synthesize CNTs filled with metal sulfide nanowires. The CNTs can be completely and continuously filled with the metal sulfide fillers up to several micrometers in length. The filled CNTs can be easily collected from the substrates used for synthesis using a simple ultrasonication method.

The present disclosure provides a method for preparing a doped YAG single crystal fiber. The method may include placing a doped YAG single crystal fiber core into a growth zone and placing a raw material into a dissolution zone; adding a mineralizer into the growth chamber to cause the mineralizer to immerse the raw material and the doped YAG single crystal fiber core; heating the growth zone and the dissolution zone by a two-stage heating device, respectively; and preparing a doped YAG single crystal fiber by growing a YAG single crystal fiber cladding on a surface of the doped YAG single crystal fiber core based on the doped YAG single crystal fiber core and the raw material under a preset pressure.

Methods for forming samples of noble metal bipyramid nanocrystals having very low size and shape polydispersities from samples of mixed noble metal nanocrystals are provided. The samples include those comprising high purity, substantially monodisperse, plasmonic gold bipyramid nanocrystals. Also provided are methods of growing secondary twinned metal nanocrystals using the noble metal bipyramid nanocrystals as seed particles. Like the seed bipyramid nanocrystals from which they are grown, the secondary nanocrystals are twinned nanocrystals and may also be characterized by very low size and shape polydispersities. Secondary twinned nanocrystals grown by these methods include enlarged metal bipyramid nanocrystals and nanocrystals with anisotropic “dumbbell” shapes having a variety of tip geometries. Methods for using noble metal bipyramid nanocrystals as plasmonic heaters to heat reaction solutions via plasmonic-photothermal radiation-to-heat conversion are also provided.

Methods for forming samples of noble metal bipyramid nanocrystals having very low size and shape polydispersities from samples of mixed noble metal nanocrystals are provided. The samples include those comprising high purity, substantially monodisperse, plasmonic gold bipyramid nanocrystals. Also provided are methods of growing secondary twinned metal nanocrystals using the noble metal bipyramid nanocrystals as seed particles. Like the seed bipyramid nanocrystals from which they are grown, the secondary nanocrystals are twinned nanocrystals and may also be characterized by very low size and shape polydispersities. Secondary twinned nanocrystals grown by these methods include enlarged metal bipyramid nanocrystals and nanocrystals with anisotropic “dumbbell” shapes having a variety of tip geometries. Methods for using noble metal bipyramid nanocrystals as plasmonic heaters to heat reaction solutions via plasmonic-photothermal radiation-to-heat conversion are also provided.

Core-shell nanostructures with platinum overlayers conformally coating palladium nano-substrate cores and facile solution-based methods for the preparation of such core-shell nanostructures are described herein. The obtained Pd@Pt core-shell nanocatalysts showed enhanced specific and mass activities towards oxygen reduction, compared to a commercial Pt/C catalyst.

Core-shell nanostructures with platinum overlayers conformally coating palladium nano-substrate cores and facile solution-based methods for the preparation of such core-shell nanostructures are described herein. The obtained Pd@Pt core-shell nanocatalysts showed enhanced specific and mass activities towards oxygen reduction, compared to a commercial Pt/C catalyst.

An apparatus for producing an ingot includes a crucible body having an opening and in which raw materials are accommodated, and a lid assembly located at the opening and having a portion fixed to the crucible body. The lid assembly includes a placement hole having open upper and lower ends, a frame member arranged along a periphery of the opening while surrounding a periphery of the placement hole, and a core member located in the placement hole and movable upward and downward with respect to the frame member.

An apparatus for producing an ingot includes a crucible body having an opening and in which raw materials are accommodated, and a lid assembly located at the opening and having a portion fixed to the crucible body. The lid assembly includes a placement hole having open upper and lower ends, a frame member arranged along a periphery of the opening while surrounding a periphery of the placement hole, and a core member located in the placement hole and movable upward and downward with respect to the frame member.