Cliver E.W.,Air Force Research Lab |
Dietrich W.F.,Praxis Inc.
Journal of Space Weather and Space Climate | Year: 2013
The solar flare on 1 September 1859 and its associated geomagnetic storm remain the standard for an extreme solar-terrestrial event. The most recent estimates of the flare soft X-ray (SXR) peak intensity and Dst magnetic storm index for this event are: SXR class = X45 (±5) (vs. X35 (±5) for the 4 November 2003 flare) and minimum Dst = -900 (+50, -150) nT (vs. -825 to -900 nT for the great storm of May 1921). We have no direct evidence of an associated solar energetic proton (SEP) event but a correlation between >30 MeV SEP fluence (F30) and flare size based on modern data yields a best guess F30 value of ~1.1 × 1010 pr cm -2 (with the ±1σ uncertainty spanning a range from ~109-1011 pr cm-2) for a composite (multi-flare plus shock) 1859 event. This value is approximately twice that of estimates/measurements - ranging from ~5-7 × 109 pr cm -2 - for the largest SEP episodes (July 1959, November 1960, August 1972) in the modern era. © E.W. Cliver et al., Published by EDP Sciences 2013. Source
Mindach M.,Praxis Inc.
Fortschritte der Neurologie Psychiatrie | Year: 2015
In February 2015, the German Ethics Council released a statement on brain death and organ removal. The Council has decided to adhere to the criterion of brain death as a condition for organ removal, and the majority of the Council holds the view of brain death as the criterion of death. The German medical associations have welcomed this statement, but there is room for further discussion of some aspects of this statement from a clinical point of view. © 2015 Georg Thieme Verlag KG Stuttgart New York. Source
Praxis Inc. | Date: 2010-01-15
A porous metal article having a predetermined pore structure. The porosity is provided by the use of an extractable particulate in a powder forming route to create a desired porosity. Extraction of the pore forming particulate prior to sintering of the powder minimizes contamination of the sintered article and allows for the processing of material sensitive to contamination such as titanium. Added functionality can be gained by co-forming the porous material with non-porous material to create an article with layers of differing characteristics. The article is suitable for use as an implant body is porous enough to facilitate tissue in-growth and bony fusion.
Praxis Inc. | Date: 2011-10-11
In one embodiment, the present invention may be a method of making a porous biocompatible metal article by combining a metal powder with a homogenizing aid to form metal granules, including blending the metal granules and an extractable particulate to form a composite, forming the composite into a green article, removing the extractable particulate from the green article to form a metal matrix and pore structure, and sintering the metal matrix and pore structure. Furthermore the present invention may include a second homogenizing aid combined with the extractable particulate. The present invention also includes shaping the metal matrix and pore structure with or without the use of a binder.
Praxis Inc. | Date: 2014-01-08
High strength implantable devices having complex surfaces are injection molded from powder metal wherein the surface is defined by a monolithic insert made by additive manufacturing. The insert defines the surface texture of the device and may also include a portion to form an ingrowth texture and a portion to form a substrate interface texture. The tensile bond strength of the texture is 20 Mega Pascal or greater.