An empirical approach to predicting long term behavior of metal particle based recording media

Alpha iron particles used for magnetic recording are prepared through a series of dehydration and reduction steps of alpha-Fe2O3-H2O resulting in acicular, polycrystalline, body centered cubic (bcc) alpha-Fe particles that are single magnetic domains. Since fine iron particles are pyrophoric by nature, stabilization processes had to be developed in order for iron particles to be considered as a viable recording medium for long term archival (i.e., 25+ years) information storage. The primary means of establishing stability is through passivation or controlled oxidation of the iron particle's surface. Since iron particles used for magnetic recording are small, additional oxidation has a direct impact on performance especially where archival storage of recorded information for long periods of time is important. Further stabilization chemistry/processes had to be developed to guarantee that iron particles could be considered as a viable long term recording medium. In an effort to retard the diffusion of iron ions through the oxide layer, other elements such as silicon, aluminum, and chromium have been added to the base iron to promote more dense scale formation or to alleviate some of the non-stoichiometric behavior of the oxide or both. The presence of water vapor has been shown to disrupt the passive layer, subsequently increasing the oxidation rate of the iron. A study was undertaken to examine the degradation in magnetic properties as a function of both temperature and humidity on silicon-containing iron particles between 50-120 deg C and 3-89 percent relative humidity. The methodology to which experimental data was collected and analyzed leading to predictive capability is discussed

What Ails Local Service Delivery of Public Goods and Services?

This Note provides an account of the problems underlying local service delivery (LSD) in the Philippines and presents some prospective solutions. The problems are examined on the basis of the three components of the Triangulation Framework for LSD developed in a recently completed PIDS-UNICEF study.millennium development goal (MDG), local service delivery, triangulation, public goods and services

Nucleosynthesis and astrophysical gamma ray spectroscopy

The HEAO-3 gamma ray spectrometer has provided evidence in the quest for the understanding of complex element formation in the universe with the discovery of Al-26 in the interstellar medium. It has demonstrated that the synthesis of intermediate mass nuclei is currently going on in the galaxy. This discovery was confirmed by the Solar Maximum Mission. The flux is peaked near the galactic center and indicates about 3 solar masses of Al-26 in the interstellar medium, with an implied ratio of Al-26/Al-27 = .00001. Several possible distributions were studied but the data gathered thus far do not allow discrimination between them. It is felt that only the spaceflight of a high resolution gamma ray spectrometer with adequate sensitivity will ultimately resolve the issue of the source of this material

Sustained eruptions on Enceladus explained by turbulent dissipation in tiger stripes

Spacecraft observations suggest that the plumes of Saturn's moon Enceladus draw water from a subsurface ocean, but the sustainability of conduits linking ocean and surface is not understood. Observations show sustained (though tidally modulated) fissure eruptions throughout each orbit, and since the 2005 discovery of the plumes. Peak plume flux lags peak tidal extension by $\sim$1 radian, suggestive of resonance. Here we show that a model of the tiger stripes as tidally-flexed slots that puncture the ice shell can simultaneously explain the persistence of the eruptions through the tidal cycle, the phase lag, and the total power output of the tiger stripe terrain, while suggesting that the eruptions are maintained over geological timescales. The delay associated with flushing and refilling of \emph{O}(1) m-wide slots with ocean water causes erupted flux to lag tidal forcing and helps to buttress slots against closure, while tidally pumped in-slot flow leads to heating and mechanical disruption that staves off slot freeze-out. Much narrower and much wider slots cannot be sustained. In the presence of long-lived slots, the 10$^6$-yr average power output of the tiger stripes is buffered by a feedback between ice melt-back and subsidence to \emph{O}(10$^{10}$) W, which is similar to the observed power output, suggesting long-term stability. Turbulent dissipation makes testable predictions for the final flybys of Enceladus by the \emph{Cassini} spacecraft. Our model shows how open connections to an ocean can be reconciled with, and sustain, long-lived eruptions. Turbulent dissipation in long-lived slots helps maintain the ocean against freezing, maintains access by future Enceladus missions to ocean materials, and is plausibly the major energy source for tiger stripe activity

Experimental study of extrusion and surface treatment of organo clay with PET nano-composites

This article was submitted to and presented at the Polymer Process Engineering 2009 conference.Inclusion of organoclay in engineering polymers is increase annually and this trend will continue for the foreseeable future despite the economic downturn. This paper describes melt blending techniques using PET nanocomposites containing commercially available organoclays with different percentage of surfactant coatings. This paper will also evaluate the morphology and mechanical properties of the composites using a range of techniques like, scanning electron microscopy, melt rheology and thermal analysis. Comparisons will be made between properties of amorphous and semi crystalline films in terms of surfactant used and material properties. It will be demonstrated that the quantity of surfactant used with the organoclays can significantly affect dispersion and properties of composites produced

Literature circles, gender and reading for enjoyment

The research was commissioned through Information and Analytical Services Division, which is responsible for providing analytical services within the Scottish Executive Education Department (SEED). Their work is part of a multidisciplinary unit (consisting of researchers, economists and statistics staff) and the staff undertakes and funds economic analysis and social research in the fields of: school education; children, young people and social work: architecture; and tourism, culture and sport

Inflation and Wage Dispersion

A large body of empirical work has demonstrated that higher inflation, especially when it is unexpected, leads to greater dispersion in the distribution of price changes across subaggregates. A sparse and more recent literature suggests exactly the opposite effects on the distribution of wage changes. This study first reconciles these apparently opposite results using a model in which shocks to the economy can affect both wages and prices and the demand for indexing. If the positive effect of shocks on the demand for indexing is sufficiently large, the dispersion of changes in wages or prices will be reduced even though the shocks' direct effect is to increase this dispersion. Implicitly from the evidence, this offset is large enough in wage-setting, but not so large in price determination. Additional evidence on the relationship between inflation and the dispersion of wage changes is provided by empirical work for 14 Israeli manufacturing industries, 1956-82. The results suggest that in Israel, just as in the United States (on which previous work has been conducted) with its much less rapid and variable inflation, dispersion also decreased with unexpected price inflation.

Convection and dynamo action in B stars

Main-sequence massive stars possess convective cores that likely harbor strong dynamo action. To assess the role of core convection in building magnetic fields within these stars, we employ the 3-D anelastic spherical harmonic (ASH) code to model turbulent dynamics within a 10 solar mass main-sequence (MS) B-type star rotating at 4 times the solar rate. We find that strong (900 kG) magnetic fields arise within the turbulence of the core and penetrate into the stably stratified radiative zone. These fields exhibit complex, time-dependent behavior including reversals in magnetic polarity and shifts between which hemisphere dominates the total magnetic energy.Comment: 2 pages, 1 figure; IAU symposium 271, Astrophysical Dynamics: From Galaxies to Star