Comment on "Indispensable Finite Time Correlations for Fokker-Planck Equations from Time Series Data"

Comment on "Indispensable Finite Time Correlations for Fokker-Planck Equations from Time Series Data"Comment: 2 pages, 1 figur

On different cascade-speeds for longitudinal and transverse velocity increments

We address the problem of differences between longitudinal and transverse velocity increments in isotropic small scale turbulence. The relationship of these two quantities is analyzed experimentally by means of stochastic Markovian processes leading to a phenomenological Fokker- Planck equation from which a generalization of the Karman equation is derived. From these results, a simple relationship between longitudinal and transverse structure functions is found which explains the difference in the scaling properties of these two structure functions.Comment: 4 pages, 5 figures, now with corrected postscrip

Social work and genetics : Sylvia Schild and Rita Beck Black. New York: The Haworth Press, 1984

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25482/1/0000022.pd

Primary Prevention in the New Millennium: The Challenge of Translating Knowledge into Action

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45092/1/10935_2004_Article_297087.pd

Spectral signatures of photosynthesis II: coevolution with other stars and the atmosphere on extrasolar worlds

As photosynthesis on Earth produces the primary signatures of life that can be detected astronomically at the global scale, a strong focus of the search for extrasolar life will be photosynthesis, particularly photosynthesis that has evolved with a different parent star. We take planetary atmospheric compositions simulated by Segura, et al. (2003, 2005) for Earth-like planets around observed F2V and K2V stars, modeled M1V and M5V stars, and around the active M4.5V star AD Leo; our scenarios use Earth's atmospheric composition as well as very low O2 content in case anoxygenic photosynthesis dominates. We calculate the incident spectral photon flux densities at the surface of the planet and under water. We identify bands of available photosynthetically relevant radiation and find that photosynthetic pigments on planets around F2V stars may peak in absorbance in the blue, K2V in the red-orange, and M stars in the NIR, in bands at 0.93-1.1 microns, 1.1-1.4 microns, 1.5-1.8 microns, and 1.8-2.5 microns. In addition, we calculate wavelength restrictions for underwater organisms and depths of water at which they would be protected from UV flares in the early life of M stars. We estimate the potential productivity for both surface and underwater photosynthesis, for both oxygenic and anoxygenic photosynthesis, and for hypothetical photosynthesis in which longer wavelength, multi-photosystem series are used.Comment: 59 pages, 4 figures, 4 tables, forthcoming in Astrobiology ~March 200

Barriers to the Employment of Welfare Recipients

Dramatic reductions in welfare caseloads since passage of the Personal Responsibility and WorkOpportunity Reconciliation Act of 1996 have not allayed policy concerns about the employability of recipients remaining on the rolls. Analysis of potential barriers to employment can address whether current recipients have problems that either singly or in combination make it difficult for them to comply with the new requirements for getting and keeping jobs. In this paper, we explore the prevalence and work effects of 14 potential barriers in a new survey of a representative sample of 753 urban single-mother recipients. We report the prevalence of the barriers and how their number predicts employment rates, controlling for demographic characteristics. We also analyze which individual barriers are associated with employment and how a model inclusive of a comprehensive array of barriers improves upon a traditional human capital model of the work effects of education and work and welfare history. Single mothers who received welfare in 1997 had higher rates of personal health and mental health problems, domestic violence, and children’s health problems than do women in national samples, but they were no more likely than the general population to be drug or alcohol dependent. Only 15 percent of respondents had none of the barriers and almost two-thirds had two or more barriers. The numbers of multiple barriers were strongly and negatively associated with working, and among the individual barriers, low education, lack of access to transportation, poor health, having drug dependence or a major depressive disorder, and several experiences of workplace discrimination reduced employment. Welfare-to-work programs need to be more finely targeted with respect to exemptions and service provision, and states should consider providing longer-term and enhanced supports for those who face low prospects of leaving welfare for employment.

Factors contributing to heat affected zone damage in Grade 91 steel feature type cross-weld tests

Grade 91 steel has been widely utilized in power plants over the last 20 years. Its specification worldwide has dramatically increased since the acceptance of ASME Code Case 1943 for this material in 1983. Recent evaluation of a combination of ex-service Grade 91 steel components and virgin material has provided a unique opportunity to revisit commonly stated factors which contribute to damage in cross-weld creep tests. The approach adopted here is grounded in the fundamental objective of linking metallurgical risk factors in Grade 91 steel to the cross-weld creep performance. Establishing metallurgical risk factors in 9%Cr steels is regarded as a key consideration in the integration of a well-engineered life management strategy for these complex materials. In this study, two heats of ex-service Grade 91 steel which exhibit a similar response to the deformation resistance (i.e. strength) but dramatic differences in the susceptibility to damage (i.e. creep ductility) were evaluated in the welded condition using large, feature type cross-weld creep samples. Heat affected zone damage was investigated from both a macro-damage and micro-damage perspective. The macro-damage evaluation provided a comprehensive understanding of the global damage distribution through the heat affected zone (HAZ). The damage was linked to extensive hardness mapping and calculated peak temperatures through the HAZ. The microdamage characterization included a number of local observations for cavities in each sample using scanning electron microscope techniques. General observations were made regarding the shape and size of creep cavities and association of damage with microstructural features. These observations were linked to the as-fabricated microstructure and as characterized by electron backscatter diffraction (EBSD) and energy dispersive x-ray spectroscopy (EDS) mapping

Cross-weld creep performance in grade 91 steel: Macro-based assessment

Meaningful characterization of the microstructure in metallurgically complex steels is complicated by the diversity of thermal cycles experienced by multipass fusion welds. To overcome the problems of relevant documentation, it is necessary to balance information from macro-, micro-, and nano-evaluation with appropriate analysis. This paper presents details regarding recommended approaches that optimize this characterization. Initially, specific procedures relevant to macroanalysis, including hardness mapping and calculation of the peak temperature through the width of the heat-affected zone (HAZ), are described. Then, assessment of the distribution of creep damage in feature-type, cross-weld creep tests using laser microscopy is detailed. Using these methods, the extent of damage through the HAZ was compared to the local reduction in the HAZ hardness and to the calculated peak temperatures in the HAZ. The implications of these findings are discussed with respect to damage, deformation, and sample geometry