20 research outputs found
Regional Dimensions of Economic Development in Iran - A New Economic Geography Approach
Validation of an SEU simulation technique for a complex processor: PowerPC7400
Results from fault injection experiments on a modern complex processor, the PPC7400, are combined with static register ground testing to predict single-event upset rates of several benchmark application programs. These results compare favorably with in-beam measurements on the same programs
Upset Characterization of the PowerPC405 Hard-core Processor Embedded in Virtex-II Pro Field Programmable Gate Arrays
Shown in this presentation are recent results for the upset susceptibility of the various types of memory elements in the embedded PowerPC405 in the Xilinx V2P40 FPGA. For critical flight designs where configuration upsets are mitigated effectively through appropriate design triplication and configuration scrubbing, these upsets of processor elements can dominate the system error rate. Data from irradiations with both protons and heavy ions are given and compared using available models
The Effect of Post-weld Heat Treatment on the Corrosion Behavior of Different Weld Zones of Titanium Ti-6Al-4V Alloy by Friction Stir Welding
On Duality of Set-Valued Optimization (Nonlinear Analysis and Convex Analysis)
Inspired by the observation that
crystalline calcium carbonate
and calcium phosphate biominerals frequently form via amorphous precursors,
a wide range of studies have been performed which demonstrate that
many inorganic crystals can precipitate from solution via amorphous
phases. This article considers the crystallization mechanism of calcium
oxalate, which is a significant biomineral in many plants and the
primary constituent of kidney stones in vertebrates, and shows that
this can also precipitate via an amorphous precursor phase from aqueous
solution. A range of approaches were employed to study calcium oxalate
formation, including precipitation in bulk solution in the presence
and absence of additives and in the spatially confined volumes offered
by track etched membranes and a crossed cylinders apparatus. A freeze
concentration method was also used to generate sufficient quantities
of amorphous calcium oxalate (ACO) for analysis. The results show
that amorphous calcium oxalate crystallizes rapidly in bulk solution
but can be significantly stabilized through the concerted activity
of additives and confinement. We also demonstrate that ACO has a composition
of ≈CaC<sub>2</sub>O<sub>4</sub>:H<sub>2</sub>O. These data
suggest that calcium oxalate biominerals, in common with their carbonate
and phosphate counterparts, may also precipitate via amorphous phases