Effect of mixing and spatial dimension on the glass transition

We study the influence of composition changes on the glass transition of binary hard disc and hard sphere mixtures in the framework of mode coupling theory. We derive a general expression for the slope of a glass transition line. Applied to the binary mixture in the low concentration limits, this new method allows a fast prediction of some properties of the glass transition lines. The glass transition diagram we find for binary hard discs strongly resembles the random close packing diagram. Compared to 3D from previous studies, the extension of the glass regime due to mixing is much more pronounced in 2D where plasticization only sets in at larger size disparities. For small size disparities we find a stabilization of the glass phase quadratic in the deviation of the size disparity from unity.Comment: 13 pages, 8 figures, Phys. Rev. E (in print

Timing of Latest Eocene Molluscan Extinction Patterns in Mississippi

Molluscs removed from 12 bulk samples of the Yazoo Formation (upper Eocene), exposed in a quarry at Cynthia, Mississippi, are similar in com- position and diversity to those found in the underlying upper Eocene Moodys Branch Formation, when dif- ferences in outcrop area are considered (74% of the Yazoo species are also found in the Moodys Branch). This suggests there was no significant extinction during the late Eocene (at the P15/P16 biozone boundary) as has been reported for planktic foraminifera. Only 11.4% of the species from the Yazoo extend into the Oligocene Red Bluff Formation, suggesting a large molluscan extinction at or near the Eocene-Oligocene boundary. The presence in the lowermost Red Bluff of an assemblage with a relatively high diversity dominated by suspension-feeding bivalves suggests that the molluscan fauna had recovered from the extinction by the earliest Oli- gocene

The Potential Constants of Ethane

The infrared and Raman data of light and heavy ethane (C2H6 and C2D6) have been reexamined for the purpose of determining as accurately as possible the potential constants of the ethane molecule. In order to fill in some of the gaps in the spectroscopic data, additional high resolution measurements have been made on the infrared spectrum of heavy ethane which have given more precise values for the active fundamental frequencies and zeta‐values. Resolution of the fine structure associated with the parallel band ν5* has given the value of the large moment of inertia of C2D6, thus completing the information required for the spectroscopic determination of the dimensions of ethane. The data yield, C☒C distance=1.543A, C☒H distance=1.102A, H☒C☒C angle=109°37′, and H☒C☒H angle=109°19′. The twenty‐two distinct potential constants compatible with the D3d symmetry of ethane have been determined through their relationships to the normal frequencies and zeta‐values of C2H6 and C2D6. The normal frequencies have been obtained by addition of anharmonic corrections to the spectroscopically observed fundamental frequencies. These corrections were estimated by means of the known anharmonic corrections for methane and the conditions imposed by the Teller product rule. The fundamental frequencies and zeta‐values have been taken directly from the observed band centers and rotational spacings wherever possible. In the cases of resonance, the influence of the couplings were either calculated or estimated and the corresponding unperturbed values for the frequencies and zeta‐values selected. The potential function is determined first in terms of a set of simple symmetry coordinates, and then reexpressed in terms of valence coordinates to permit comparison of the valence force constants of ethane and methane.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70194/2/JCPSA6-20-2-313-1.pd

Reliability of Manure Application Rates to Predict Availability of Swine Manure-N in Cornfields

Efficient use of the nitrogen in animal manures is essential for economic and environmental reasons. It requires applying the manure appropriately and making adjustments for this N if commercial fertilizer also is applied. Estimates of the amounts of plant-available N supplied by animal manures commonly are based on amounts of manure-N applied. Adjustments are often made for expected losses of N soon after application. These estimates are made with the knowledge that there is unpredictable variability in amounts of N rendered unavailable by ammonia volatilization, surface runoff, inunobilization, leaching, or denitrification. Although it is known to be substantial, there has been no practical method for addressing this variability. Advances in soil testing and plant analysis have provided new tools for estimating amounts of plant available N in soils. Soil testing for nitrate when com plants are between 6 and 12 in. gives estimates of N availability just before it is needed by the crop. This test can be used to evaluate the N-supplying power of manure applied to cornfields. In this study we use soil testing and yield response measurements to learn more about the relationship between rates of manure-N application and amounts of N available to com. The study centers on liquid swine manure from modem confinement buildings to minimize differences in quality of manure applied

Construct-Validity of the Engagement with Challenge Measure for Adolescents: Structural- and Criterion-Validity Evidence

This is the published version.For adolescents, engaging with challenge is a key developmental task, hypothesized to support development of adult-like competencies (e.g., agency and self-direction; Larson, 2000). This study aimed to assess the construct-validity (structural- and concurrent-validity) of a new self-report measure assessing adolescents’ engagement with challenge to help researchers understand how different settings and the conditions in these settings support adolescents’ development. The sample consisted of 337 adolescents in 10 FFA programs along with the adult advisors in each program. Adolescents completed a questionnaire, which included the Engagement with Challenge measure and the following criterion variables: number of contests completed, participation frequency, and leadership roles. In addition to the self-reported criterion variables, the adult advisor evaluated Engagement with Challenge for each FFA student member in that program using a single item. The findings of this study provided strong evidence for the structural-validity of the engagement with challenge construct measured by the new scale, including having passed confirmatory factor analysis configural, weak, and strong invariance tests across four grade groupings. The findings also provided further evidence of construct-validity, as Engagement with Challenge correlated in the a priori hypothesized direction and magnitude. Suggestions for analysis with the new measure and for future research are presented

What Does the Late-Spring Soil Test Really Measure?

The late-spring test for soil nitrate has been available in Iowa for about 10 years. Guidelines for using this test clearly indicate that the test measures concentrations of nitrate in the surface foot of soil when corn plants are 6 to 12 inches tall. Ongoing discussions concerning the reliability of the soil test, however, indicate uncertainty in what should be concluded from the soil nitrate concentrations measured

Superconductivity in NdFe1-xCoxAsO (0.05 < x < 0.20) and rare-earth magnetic ordering in NdCoAsO

The phase diagram of NdFe1-xCoxAsO for low cobalt substitution consists of a superconducting dome (0.05 < x < 0.20) with a maximum critical temperature of 16.5(2) K for x = 0.12. The x = 1 end member, NdCoAsO, is an itinerant ferromagnet (TC = 85 K) with an ordered moment of 0.30(1) BM at 15 K. Below TN = 9 K, Nd spin-ordering results in the antiferromagnetic coupling of the existing ferromagnetic planes. Rietveld analysis reveals that the electronically important two-fold tetrahedral angle increases from 111.4 to 115.9 deg. in this series. Underdoped samples with x = 0.046(2) and x = 0.065(2) show distortions to the orthorhombic Cmma structure at 72(2) and 64(2) K, respectively. The temperature dependences of the critical fields Hc2(T) near Tc are linear with almost identical slopes of 2.3(1) T K-1 for x = 0.065(2), x = 0.118(2) and x = 0.172(2). The estimated critical field Hc2(0) and correlation length for optimally doped samples are 26(1) T and 36(1) Angstrom. A comparison of the maximum reported critical temperatures of well-characterized cobalt doped 122- and 1111-type superconductors is presented.Comment: accepted to PR

Adolescent Development in Context: Social, Psychological, and Neurological Foundations

This project was funded by KU Libraries’ Parent’s Campaign with support from the David Shulenburger Office of Scholarly Communication & Copyright and the Open Educational Resources Working Group in the University of Kansas Libraries.Increasingly, there is a tendency to characterize the teenage years as a time of general moral degeneration and deviance. This is unfortunate because the teenage years represent a key developmental period of the typical human lifespan, and from an evolutionary point of view, the actual characteristics that define adolescence represent critical learning opportunities. The increased sensitivity to social influences, identity formation, and social-emotional skills are just a few of such opportunities that require appropriate environments and contexts for optimal, healthy outcomes. Research in the field of adolescent development has not been immune to the negative stereotypes surrounding adolescence, and it is common to see researchers, either implicitly or explicitly, refer to adolescence as a high-risk, anomalous developmental stage that must be controlled, managed, or simply endured until adult-level abilities emerge spontaneously as a result of having survived an intrinsically tumultuous developmental time. More enlightened views of adolescence recognize that all biological adaptations have a cause and a purpose, and that the purpose of adolescence can be discerned from understanding the complex evolutionary history of humans as a group-based, family-based, highly social, sometimes competitive, abstract-thinking species. Understanding the biological foundations of adolescence is meaningless if one does not also consider how biology and environment interact. In humans, these interactions are highly complex and involve not only immediate physical realities, but also social, cultural, and historical realities that create complex contexts and webs of interactions. Therefore, this textbook seeks to reconcile the biological and neurological foundations of human development with the psychological and sociological mechanisms that formed and continue to influence human developmental trajectories. To this end, we have divided the textbook into three main sections. The first, Foundations of Adolescent Development, introduces the historical science of studying adolescence and the biological foundations of puberty. The second section, Contexts of Adolescent Development, considers the primary contextual factors that influence developmental outcomes during adolescence. These include work and employment, peers, in-school and out-of-school contexts, leisure time, and the family. The final section, Milestones of Adolescent Development, addresses the primary psychological milestones that represent healthy adjustment to adult roles and responsibilities in society. The domains of these milestones include cognition and decision-making; identity, meaning, and purpose, moral development, and sexuality. From an educational point of view, the objective of this textbook is to provide a resource that is capable of fostering advanced conceptual change and learning in the field of adolescent development in order to go beyond stereotypical portrayals of adolescence as a pathological condition. Organized in a manner designed to scaffold increasingly complex ideas, the textbook redefines adolescence a sensitive period of development characterized by phylogenetically derived experience-expectant states and complex interactions of biological, psychological, and social factors. The textbook draws from the latest advances in neuroscience and psychology to construct a practical framework for use in a wide range of academic and professional contexts, and it presents historical as well as contemporary research to accomplish a radical redefining of an often misunderstood and maligned developmental period