NOAA 26.5 Ah LEO characterization test

The General Electric (GE) 26.5 Ah NOAA-G flight nickel-cadmium cells were obtained from RCA-Astro Electronics to undergo performance characterization testing at the Goddard Space Flight Center (GSFC). This lot of cells was manufactured with passivated positive plate, to control nickel structure attack duing active material impregnation, and less electrolyte than normal (less than 3cc/Ah). The cells were tested in a parametric low Earth orbit (LEO) cycling regime that was previously used to test and characterize standard 50 Ah cells. Life cycle testing at the Naval Weapons Support Center (NWSC), in Crane, followed. The results of the test showed nominal performance in comparison with previous test data on the standard 50. Life cycle testing in the NOAA orbital regime is continuing at NWSC

Comparison of Standard and Heart-pacer Type 3rd Electrodes in Design Variable Cells

Nine packs of sealed aerospace nickel cadmium cells were put on life test in February 1979. Each 5 cell pack contained one cell with a standard sensor signal electrode and one cell with a new heart pacer sensor signal electrode. Testing was discontinued in May 1983 and the signal electrode performance data was studied. It was found that the heart pacer electrode generally provided a greater voltage swing over a cycle; that both types of electrodes lost significant sensitivity during life, and that both types of electrodes show great signal variation from cell to cell

Qualification Testing of General Electric 50 Ah Nickel-Cadmium Cells with New Separator and New Positive Plate Processing

Forty-two 50 Ah aerospace nickel-cadmium cells were delivered to Goddard Space Flight Center (GSFC) by General Electric (GE) in February, 1985, for the purpose of evaluating and qualifying a new nylon separator material Pellon 2536, and the new GE Positive Plate Nickel Attack Control Passivation process. Testing began in May, 1985, at the Naval Weapons Support Center (NWSC) in Crane, Indiana with standard initial evaluation tests. Life cycling in both Low Earth Orbit (LEO) and Geosynchronous Orbit (GEO) began in July, 1985, with approximately 1200 LEO cycles complete at this writting. Early test results show that cells with positive plate passivation exhibit higher than normal charge voltage characteristics. Other aspects of performance were nominal

Nickel Cadmium Cell Design Variable Program Data Analysis

A program was undertaken to evaluate eight of the more important nickel-cadmium cell designs that are currently being used or that have been used during the past 15 years. Design variables tested in this program included teflonated negative plates, silver treated negative plates, light plate loading level, no positive plate cadmium treatment, plate design of 1968, utilizing both old and new processing techniques, and electrochemically impregnated positive plates. The data acquired from these test packs in a low Earth orbit cycling regime is presented and analyzed here. This data showed conclusively that the cells manufactured with no positive plate cadmium treatment outperformed all other cell designs in all aspects of the program and that the cells with teflonated negative electrodes performed very poorly

Qualification testing of General Electric 50 Ah nickel-cadmium cells with Pellon 2536 separator and passivated positive plates

Forty-two 50 Ah nickel-cadmium cells were delivered to the Goddard Space Flight Center (GSFC) by General Electric (GE) in February, 1985 for the purpose of evaluating and qualifying a nonwoven nylon separator material, Pellon 2536, and the GE positive plate nickel attack control gas passivation process. Testing began May, 1985 at the Naval Weapons Support Center (NWSC) in Crane, Indiana with GSFC standard initial evaluation tests. Life cycling in both Low Earth Orbit (LEO) and Geosynchronous Orbit (GEO) began in July, 1985 with approximately 6500 LEO cycles and three GEO eclipse seasons completed. After early problems in maintaining test pack temperature control, all packs are performing well but are exhibiting higher than normal charge voltage characteristics

Should Optimal Designers Worry About Consideration?

Consideration set formation using non-compensatory screening rules is a vital component of real purchasing decisions with decades of experimental validation. Marketers have recently developed statistical methods that can estimate quantitative choice models that include consideration set formation via non-compensatory screening rules. But is capturing consideration within models of choice important for design? This paper reports on a simulation study of a vehicle portfolio design when households screen over vehicle body style built to explore the importance of capturing consideration rules for optimal designers. We generate synthetic market share data, fit a variety of discrete choice models to the data, and then optimize design decisions using the estimated models. Model predictive power, design "error", and profitability relative to ideal profits are compared as the amount of market data available increases. We find that even when estimated compensatory models provide relatively good predictive accuracy, they can lead to sub-optimal design decisions when the population uses consideration behavior; convergence of compensatory models to non-compensatory behavior is likely to require unrealistic amounts of data; and modeling heterogeneity in non-compensatory screening is more valuable than heterogeneity in compensatory trade-offs. This supports the claim that designers should carefully identify consideration behaviors before optimizing product portfolios. We also find that higher model predictive power does not necessarily imply better design decisions; that is, different model forms can provide "descriptive" rather than "predictive" information that is useful for design.Comment: 5 figures, 26 pages. In Press at ASME Journal of Mechanical Design (as of 3/17/15

EU pension reform - An overview of the debate and an empirical assessment of the main policy reform options

This paper on European Union (EU) pension reform provides an overview of the debate and, on the basis of a series of model simulations, makes an empirical assessment of the main pension policy reform options at the EU, not the Member State, level. It estimates what it would take to bring the public PAYG pension system back into equilibrium and assesses the case for a shift to funding. The main conclusion of this paper is that the EU pension system should in the very long run (i.e. over more than one generation) be fully funded, with this being achieved using a two-stage optimal transition path. Stage one of this transition process should concentrate on stabilising the PAYG system and achieving a partial shift to funding, with stage two only occurring once circumstances permit. The fully funded system, once established, should have public and private pillars, with the public system in effect replacing the old PAYG system with a similar compulsory, defined benefit, system and with the private pillar being a voluntary, defined contribution, system.pension reform, policy reform options, ageing model, Mc Morrow, R�ger,

Numerical investigation of controlling interfacial instabilities in non-standard Hele-Shaw configurations

Viscous fingering experiments in Hele-Shaw cells lead to striking pattern formations which have been the subject of intense focus among the physics and applied mathematics community for many years. In recent times, much attention has been devoted to devising strategies for controlling such patterns and reducing the growth of the interfacial fingers. We continue this research by reporting on numerical simulations, based on the level set method, of a generalised Hele-Shaw model for which the geometry of the Hele-Shaw cell is altered. First, we investigate how imposing constant and time-dependent injection rates in a Hele-Shaw cell that is either standard, tapered or rotating can be used to reduce the development of viscous fingering when an inviscid fluid is injected into a viscous fluid over a finite time period. We perform a series of numerical experiments comparing the effectiveness of each strategy to determine how these non-standard Hele-Shaw configurations influence the morphological features of the inviscid-viscous fluid interface. Tapering plates in either converging or diverging directions leads to reduced metrics of viscous fingering at the final time when compared to the standard parallel configuration, especially with carefully chosen injection rates; for the rotating plate case, the effect is even more dramatic, with sufficiently large rotation rates completely stabilising the interface. Next, we illustrate how the number of non-splitting fingers can be controlled by injecting the inviscid fluid at a time-dependent rate while increasing the gap between the plates. Simulations compare well with previous experimental results for various injection rates and geometric configurations. Further, we demonstrate how the fully nonlinear dynamics of the problem affect the number of fingers that emerge and how well this number agrees with predictions from linear stability analysis

Structural synthesis of a stiffened cylinder

Structural synthesis of cylindrical shell reinforced with rectangular cross section stiffener