Single event upset tests of a RISC-based fault-tolerant computer

The project successfully demonstrated that dual lock-step comparison of commercial RISC processors is a viable fault-tolerant approach to handling SEU in space environment. The fault tolerant approach on orbit error rate was 38 times less than the single processor error rate. The random nature of the upsets and appearance in critical code section show it is essential to incorporate both hardware and software in the design and operation of fault-tolerant computers

Homogenization of nonlinearly elastic materials, microscopic bifurcation and macroscopic loss of rank-one convexity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46162/1/205_2004_Article_BF00380256.pd

Diagnostic development for determining the joint temperature/soot statistics in hydrocarbon-fueled pool fires : LDRD final report.

A joint temperature/soot laser-based optical diagnostic was developed for the determination of the joint temperature/soot probability density function (PDF) for hydrocarbon-fueled meter-scale turbulent pool fires. This Laboratory Directed Research and Development (LDRD) effort was in support of the Advanced Simulation and Computing (ASC) program which seeks to produce computational models for the simulation of fire environments for risk assessment and analysis. The development of this laser-based optical diagnostic is motivated by the need for highly-resolved spatio-temporal information for which traditional diagnostic probes, such as thermocouples, are ill-suited. The in-flame gas temperature is determined from the shape of the nitrogen Coherent Anti-Stokes Raman Scattering (CARS) signature and the soot volume fraction is extracted from the intensity of the Laser-Induced Incandescence (LII) image of the CARS probed region. The current state of the diagnostic will be discussed including the uncertainty and physical limits of the measurements as well as the future applications of this probe

Boundary objects, social meanings and the success of new technologies

Boundary objects are entities that enhance the capacity of an idea, theory or practice to translate across culturally defined boundaries, for example, between communities of knowledge or practice. This concept thus has potential to both explain and predict technology adoption; however, it remains sociologically under-theorized. This article assesses, by recourse to a historical case study of innovations in surgical sterility, how boundary objects work and their relationship to social meanings within communities of practice. It is concluded that not only are there positive and negative boundary objects, but that technological devices or processes may themselves act as facilitative or inhibitory boundary objects during innovation. The approach set out here has potential as a sociologically informed model of improving adoption of technologies and policies by managing the positive and negative social meanings of technology objects

Contributions of nitrogen and phosphorus from three agricultural systems of "el jihuite" watershed, in jalisco, méxico [Aportes de nitrógeno y fósforo de tres sistemas agrícolas de la cuenca hidrográfica "el jihuite", en jalisco, méxico]

The El Jihuite watershed has a reservoir with the same name, which is used for the inhabitants of Tepatitlán, in the state of Jalisco, México. However, the problem of eutrophication has been observed in the water of the dam and phosphorous as a limiting factor, although there is no knowledge on the processes taking place on the lands with agricultural use, in which the enrichment of this nutrient in this reservoir takes place. Nitrogen and phosphorous losses brought about by maize, tequila agave and grass crops were evaluated on a scale of field plot, in order to quantify the nutrients produced by these agricultural systems and identify the processes related to the eutrophication of the El Jihuite dam. Nitrogen loss was seen to be related to surface runoff, whereas phosphorous depended on the water erosion of the agricultural systems studied. The loss of inorganic nitrogen in tequila agave, maize, bare soil and native grass, for 2002, was of 7, 4.6, 3.9 and 3 kg ha-1; in 2003 it was 14.9, 7.2, 8.6 and 2.4 kg ha-1. Total loss of phosphorous in the same crops for 2002 was 3.7, 3.4, 1.7 and 0.1 kg ha?1; in 2003 it was 10.8, 7.8, 4.3 and 0.0 kg ha-1. Phosphorous is a limiting factor in the eutrophication of the El Jihuite dam, and its correction will rely on the control of water erosion on lands with agricultural use; soil conservation practices should therefore be encouraged

Contributions of nitrogen and phosphorus from three agricultural systems of "el jihuite" watershed, in jalisco, méxico [Aportes de nitrógeno y fósforo de tres sistemas agrícolas de la cuenca hidrográfica "el jihuite", en jalisco, méxico]

The El Jihuite watershed has a reservoir with the same name, which is used for the inhabitants of Tepatitlán, in the state of Jalisco, México. However, the problem of eutrophication has been observed in the water of the dam and phosphorous as a limiting factor, although there is no knowledge on the processes taking place on the lands with agricultural use, in which the enrichment of this nutrient in this reservoir takes place. Nitrogen and phosphorous losses brought about by maize, tequila agave and grass crops were evaluated on a scale of field plot, in order to quantify the nutrients produced by these agricultural systems and identify the processes related to the eutrophication of the El Jihuite dam. Nitrogen loss was seen to be related to surface runoff, whereas phosphorous depended on the water erosion of the agricultural systems studied. The loss of inorganic nitrogen in tequila agave, maize, bare soil and native grass, for 2002, was of 7, 4.6, 3.9 and 3 kg ha-1; in 2003 it was 14.9, 7.2, 8.6 and 2.4 kg ha-1. Total loss of phosphorous in the same crops for 2002 was 3.7, 3.4, 1.7 and 0.1 kg ha?1; in 2003 it was 10.8, 7.8, 4.3 and 0.0 kg ha-1. Phosphorous is a limiting factor in the eutrophication of the El Jihuite dam, and its correction will rely on the control of water erosion on lands with agricultural use; soil conservation practices should therefore be encouraged