BACKGROUND Algae powders have been increasingly used in therapeutic preparations. Their potential as inducers of occupational asthma (OA), however, remains to be demonstrated. METHODS A 33-year-old woman developed asthma following exposure to algae powder used for thalassotherapy. She had positive patch tests to nickel and cobalt in an evaluation for intermittent skin rash. At work, she had a...

Laser-based additive manufacturing (LBAM) requires precise control over the metal, ceramic, or carbide powder added to the molten pool. The feeding rate of the powder must be very consistent, and it must respond rapidly to commands to change the feeding rate. LBAM also requires feeding rates as low as one gram per minute. Currently, commercially available powder feeders are optimized for such t...

We report on the first observation of isolated large neutral metal amino acid complexes such as Trp(n)Me(k), with Me=Ca, Ba, Sr, cluster combinations covering n=1...33, k=0..2 and masses beyond 6500 u. The cluster beam is generated using UV laser desorption from a mixed powder of alkaline-earth metal salts and tryptophan inside a cluster mixing channel. The particles are detected using VUV phot...

Laser-powder bed fusion (L-PBF) additive manufacturing involves complex physics such as heat transfer and molten metal flow, which have a significant influence on the final build quality. In this study, transport phenomena based modeling is used to provide a quantitative understanding of complex molten pool transients. In particular, a three dimensional (3D), transient numerical model is develo...

The paper reports on an investigation into the various aspects of closed die cold forging of polygonal powder preforms, which have been compacted and sintered from atomized powder. It is found that for certain dimensional ratios of the preform the die pressure is minimum. An attempt has been made for the determination of the die pressures developed for given geometries of the disc during the cl...

A unit cell based numerical approach to model the metal powders and metal-dielectric composites at microwave frequencies is proposed. The unit cell based numerical modeling helps to compute the equivalent reflection and transmission coefficients of these materials, which are commonly used measured parameters at RF and microwave frequencies. The computation of the reflection and transmission coe...

Grain structure control is challenging for metal additive manufacturing (AM). Grain structure optimization requires the control of grain morphology with grain size refinement, which can improve the mechanical properties of additive manufactured components. This work summarizes methods to promote fine equiaxed grains in both the additive manufacturing process and subsequent heat treatment. Influ...

The ability to fabricate geometrically complex copper shapes via Additive Manufacturing (AM) could have a significant impact on the design and performance of thermal management systems and structural electronics. In this research a Binder Jetting AM process (ExOne R2) was used to fabricate green parts made of high purity copper powder. Once printed, the green part was sintered under a reducing ...