New low-temperature methods to produce GaN:Eu and Ga2O3 :Eu (0 x 1) highly-luminescent powders are presented. These procedures yield finely divided powders through exothermic reactions between the precursors. The preparation of Eu-doped Ga2O3 powders was achieved using a new combustion synthesis technique (hydrazine/metal-nitrate method). The process starts with aqueous solutions of Eu(NO3)3 an...

In this work infiltration behavior of mechanical alloyed 75 wt% Cu – 25 wt% WC powders into porous WC compacts were studied. Owing to their ductile nature, initial Cu powders were directly added to mechanical alloying batch. On the other hand initial WC powders were high energy milled prior to mechanical alloying. Contact infiltration method was selected for densification and compacts prepared ...

High-quality rare-earth-ion (REI) doped materials are a prerequisite for many applications such as quantum memories, ultra-high-resolution optical spectrum analyzers and information processing. Compared to bulk materials, REI doped powders offer low-cost fabrication and a greater range of accessible material systems. Here we show that crystal properties, such as nuclear spin lifetime, are stron...

In order to comply with current trends concerning sustainability, saving of primary materials and energy savings, this paper addresses Eco-concrete. The major focus thereby is on the increased efficiency of cement use. Applying a new mix design method for concrete, cement contents can be decreased and partially be substituted by other fine powders, preferentially by waste powders which have no ...

The authors interviewed 116 female residents of western Washington State with serous and mucinous borderline ovarian tumors diagnosed between 1980 and 1985 and questioned them on their use of hygienic powders. A sample of 158 control women from the same counties were identified through random digit dialing and were interviewed as well. Neither the perineal application of baby powder nor the per...

This paper demonstrates that seeding nanocrystalline transition alumina powders is a viable option for producing high quality, alumina-based ceramics. By using a-Al2O3 concentrations of 51.25 wt.% a-Al2O3 seed particles (equivalent to 5 10 seeds/cm of g-Al2O3) the sintering temperature is reduced from 1600 C for unseeded g-Al2O3 to 1300–1400 C in dry pressed powders. The scale of the sinteredmi...

We study the packing of fine glass powders of mean particle diameter in the range (4-52) μm both experimentally and by numerical DEM simulations. We obtain quantitative agreement between the experimental and numerical results, if both types of attractive forces of particle interaction, adhesion and non-bonded van der Waals forces are taken into account. Our results suggest that considering only...

When NiTi powder compacts containing Nb wires are heated above 1 170 8C, each Nb wire reacts with adjacent NiTi powders to form a eutectic liquid which wicks into the space between the remaining NiTi powders. This creates a macropore at the location of the Nb wire while eliminating the microporosity between NiTi powders which is filled with a NiTi/Nb eutectic phase after solidification. This no...

Novel carbon nanotubes±metal±ceramic nanocomposite powders and dense materials have been prepared and their microstructure and mechanical properties have been investigated. After a brief review on the structure, synthesis and physical properties of carbon nanotubes, we describe an original catalytic method that produces ceramic±matrix composite powders that contain in situ grown nanotubes. The ...

Synthetic multi-substituted hydroxyapatite nano powders containing silicon and or carbonate prepared by a wet chemical method. The process parameters are set up to allow the simultaneous substitution of carbonate and silicon ions in the place of phosphorus. The chemical and structural characterizations of the prepared powders are determined with the aid of; XRF, ICP, XRD and FTIR. The results s...