27,984 research outputs found
Film breakers prevent migration of aqueous potassium hydroxide in fuel cells
Electrolyte film breakers made from polytetrafluoroethylene are installed in the reactant and water vapor removal outlets of each cell and sealed by elastomers. Use of these devices in the water vapor removal cavity outlets prevents loss of KOH solution through film migration during water removal
Fuel cell module development plan - Activity 145 - 205
Development plan for fuel cell modules consisting of 35 two-cell sections and incorporating static moisture control subsystems as integral part of modul
The Economic Welfare Cost of Conflict: An Empirical Assessment
War, whether external or internal, large or small, is a costly endeavor. Loss of life, loss of close friends or family, and the destruction of material possessions all play a part in the costs of war. The purpose of this paper is to capture only the material, economic welfare costs of conflict stemming from the altered path of consumption resulting from conflict. As such, our measure is quite a lower bound for the true and more encompassing welfare loss from living in a non-peaceful world. Remarkably, however, even these pure economic welfare losses from conflict are large. We find that, on average, individuals would give up over 8 percent of their current level of consumption to live in a peaceful world. Such large potential welfare gains from reducing warfare should make economists and policy-makers take note.Growth; Conflict; Welfare Costs
Normal and conormal maps in homotopy theory
Let M be a monoidal category endowed with a distinguished class of weak
equivalences and with appropriately compatible classifying bundles for monoids
and comonoids. We define and study homotopy-invariant notions of normality for
maps of monoids and of conormality for maps of comonoids in M. These notions
generalize both principal bundles and crossed modules and are preserved by nice
enough monoidal functors, such as the normaliized chain complex functor.
We provide several explicit classes of examples of homotopy-normal and of
homotopy-conormal maps, when M is the category of simplicial sets or the
category of chain complexes over a commutative ring.Comment: 32 pages. The definition of twisting structure in Appendix B has been
reformulated, leading to further slight modifications of definitions in
Section 1. To appear in HH
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Volumetric Calibration Refinement using masked back projection and image correlation superposition
This paper deals with a new, reconstruction based, approach of refining a volumetric calibration. The technique is based on a 2D cross-correlation between particle images on the sensor plane with a planar back projection from a tomographic reconstruction in the same sensor plane to determine potential disparities between the initial camera calibration and the measurement. Additive superposition of the correlation maps from different sets or particle images allows reducing the influence of noise and ghost particles such that the systematic errors in the calibration can be corrected. The different sections describe the theory, the principle processing steps and the convergence of the procedure. Furthermore, the concept is proven by simulating the entire process of the measurement chain, with the help of a synthetic comparison. The results show that disparities of over 9 pixels could be corrected to an average of below 0.1 pixels during the refinement steps. Finally, the technique demonstrates it´s potential to measured data, where the numbers of outliers in the raw results are reduced after the volumetric calibration refinement
What’s in a Name?
Plenty. This paper analyzes two broad questions: Does your first name matter? And how did you get your first name anyway? Using data from the National Opinion Research Centers (NORC’s) General Social Survey, including access to respondents first names from the 1994 and 2002 surveys, we extract the important “first name features” (FNF), e.g. popularity, number of syllables, phonetic features, Scrabble score, “blackness” (i.e. the fraction of people with that name who are black), etc ... We then explore whether these first name features are useful explanatory factors of a respondent’s exogenous background factors (sex, race, parents’ education, etc...) and lifetime outcomes (e.g. financial status, occupational prestige, perceived social class, education, happiness, and whether they became a parent before 25). We find that first name features on their own do have significant predictive power for a number of these lifetime outcomes, even after controlling for a myriad of exogenous background factors. We find evidence that first name features are independent predictors of lifetime outcomes that are likely related to labor productivity such as education, happiness and early fertility. Importantly, however, we also find evidence based on the differential impacts of gender and race on the blackness of a name and its popularity that suggest that discrimination may also be a factor.names, identity, discrimination
Does wage inflation cause price inflation?
Is there any evidence to support the assumption that increased wages cause inflation? This study updates and expands earlier research into this question and finds little support for the view that higher wages cause higher prices. On the contrary, more evidence is found for higher prices leading to wage growth.Inflation (Finance) ; Wages ; Prices
Vent subsystem - development plan
Vent subsystem design specifications for use in fuel cell assembl
Calculation of compressible flow in and about three-dimensional inlets with and without auxiliary inlets by a higher-order panel method
A three dimensional higher order panel method was specialized to the case of inlets with auxiliary inlets. The resulting program has a number of graphical input-output features to make it highly useful to the designer. The various aspects of the program are described instructions for its use are presented
A geometry package for generation of input data for a three-dimensional potential-flow program
The preparation of geometric data for input to three-dimensional potential flow programs was automated and simplified by a geometry package incorporated into the NASA Langley version of the 3-D lifting potential flow program. Input to the computer program for the geometry package consists of a very sparse set of coordinate data, often with an order of magnitude of fewer points than required for the actual potential flow calculations. Isolated components, such as wings, fuselages, etc. are paneled automatically, using one of several possible element distribution algorithms. Curves of intersection between components are calculated, using a hybrid curve-fit/surface-fit approach. Intersecting components are repaneled so that adjacent elements on either side of the intersection curves line up in a satisfactory manner for the potential-flow calculations. Many cases may be run completely (from input, through the geometry package, and through the flow calculations) without interruption. Use of the package significantly reduces the time and expense involved in making three-dimensional potential flow calculations
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