Electrolytic silver ion cell sterilizes water supply

Electrolytic water sterilizer controls microbial contamination in manned spacecraft. Individual sterilizer cells are self-contained and require no external power or control. The sterilizer generates silver ions which do not impart an unpleasant taste to water

Water management system and an electrolytic cell therefor Patent

Description of electrical equipment and system for purification of waste water by producing silver ions for bacterial contro

On the Numerical Dispersion of Electromagnetic Particle-In-Cell Code : Finite Grid Instability

The Particle-In-Cell (PIC) method is widely used in relativistic particle beam and laser plasma modeling. However, the PIC method exhibits numerical instabilities that can render unphysical simulation results or even destroy the simulation. For electromagnetic relativistic beam and plasma modeling, the most relevant numerical instabilities are the finite grid instability and the numerical Cherenkov instability. We review the numerical dispersion relation of the electromagnetic PIC algorithm to analyze the origin of these instabilities. We rigorously derive the faithful 3D numerical dispersion of the PIC algorithm, and then specialize to the Yee FDTD scheme. In particular, we account for the manner in which the PIC algorithm updates and samples the fields and distribution function. Temporal and spatial phase factors from solving Maxwell's equations on the Yee grid with the leapfrog scheme are also explicitly accounted for. Numerical solutions to the electrostatic-like modes in the 1D dispersion relation for a cold drifting plasma are obtained for parameters of interest. In the succeeding analysis, we investigate how the finite grid instability arises from the interaction of the numerical 1D modes admitted in the system and their aliases. The most significant interaction is due critically to the correct represenation of the operators in the dispersion relation. We obtain a simple analytic expression for the peak growth rate due to this interaction.Comment: 25 pages, 6 figure

Realization of the Large Mixing Angle Solar Neutrino Solution in an SO(10) Supersymmetric Grand Unified Model

An SO(10) supersymmetric grand unified model proposed earlier leading to the solar solution involving ``just-so'' vacuum oscillations is reexamined to study its ability to obtain the other possible solar solutions. It is found that all four viable solar neutrino oscillation solutions can be achieved in the model simply by modification of the right-handed Majorana neutrino mass matrix, M_R. Whereas the small mixing and vacuum solutions are easily obtained with several texture zeros in M_R, the currently-favored large mixing angle solution requires a nearly geometric hierarchical form for M_R that leads by the seesaw formula to a light neutrino mass matrix which has two or three texture zeros. The form of the matrix which provides the ``fine-tuning'' necessary to achieve the large mixing angle solution can be understood in terms of Froggatt-Nielsen diagrams for the Dirac and right-handed Majorana neutrino mass matrices. The solution fulfils several leptogenesis requirements which in turn can be responsible for the baryon asymmetry in the universe.Comment: 14 pages including 2 figure

Resonant leptogenesis in a predictive SO(10) grand unified model

An SO(10) grand unified model considered previously by the authors featuring lopsided down quark and charged lepton mass matrices is successfully predictive and requires that the lightest two right-handed Majorana neutrinons be nearly degenerate in order to obtain the LMA solar neutrino solution. Here we use this model to test its predictions for baryogenesis through resonant-enhanced leptogenesis. With the conventional type I seesaw mechanism, the best predictions for baryogenesis appear to fall a factor of three short of the observed value. However, with a proposed type III seesaw mechanism leading to three pairs of massive pseudo-Dirac neutrinos, resonant leptogenesis is decoupled from the neutrino mass and mixing issues with successful baryogenesis easily obtained.Comment: 22 pages including 1 figure; published version with reference adde

Engineering Economics as a Benchmark Course in the Context of a Sustainable Continuous Improvement Process

Programs seeking ABET accreditation must demonstrate that they satisfy eight general accreditation criteria, plus any program specific criteria.The two most important and widely debated ABET accreditation criteria are Student Outcomes (SOs), and Continuous Improvement (CI). While ABET has always encouraged program improvement as part of the accreditation process, Continuous Improvement (CI) has emerged as the most important criterion for accreditation.The primary inputs to this criterion are the results of assessment and evaluation of SOs. And, course-embedded assessment plays a major role in the assessment of Student Outcomes.The outcomes of the CI process are the changes that improve an engineering program. Since 2006, we have been periodically reviewing our assessment and evaluation processes with a goal to reduce the amount of time faculty spend in gathering and analyzing data. The outcome of this effort is a more sustainable CI process; a process in which not all courses are involved in course-embedded assessment and not all student outcomes are assessed and evaluated every year. The choice of courses for course-embedded assessment is guided by two principles:(1) each Student Outcome is assessed with student work in a benchmark course, and (2) only required courses, not elective courses, in the curriculum are selected as benchmark courses. Assessment of a benchmark course is conducted with the following in mind:(1) assessment of student work measures the extent to which SOs are being attained, (2) it is not necessary to use all of the student work to assess an outcome, and (3) outcomes assessment is based upon student work and is guided by the grading of that work. The implementation of our course-embedded assessment method to a benchmark course, namely Engineering Economics, is presented in this paper. A description of the process, data collection efforts, and analysis of the results in applying course embedded assessment method to the benchmark course are presented in this article