Phase field crystal dynamics for binary systems: Derivation from dynamical density functional theory, amplitude equation formalism, and applications to alloy heterostructures

The dynamics of phase field crystal (PFC) modeling is derived from dynamical density functional theory (DDFT), for both single-component and binary systems. The derivation is based on a truncation up to the three-point direct correlation functions in DDFT, and the lowest order approximation using scale analysis. The complete amplitude equation formalism for binary PFC is developed to describe the coupled dynamics of slowly varying complex amplitudes of structural profile, zeroth-mode average atomic density, and system concentration field. Effects of noise (corresponding to stochastic amplitude equations) and species-dependent atomic mobilities are also incorporated in this formalism. Results of a sample application to the study of surface segregation and interface intermixing in alloy heterostructures and strained layer growth are presented, showing the effects of different atomic sizes and mobilities of alloy components. A phenomenon of composition overshooting at the interface is found, which can be connected to the surface segregation and enrichment of one of the atomic components observed in recent experiments of alloying heterostructures.Comment: 26 pages, 5 figures; submitted to Phys. Rev.

Why the Amish Sing

An intimate portrait of the diverse music-making at the center of Amish faith and life.Singing occurs in nearly every setting of Amish life. It is a sanctioned pleasure that frames all Amish rituals and one that enlivens and sanctifies both routine and special events, from household chores, road trips by buggy, and family prayer to baptisms, youth group gatherings, weddings, and “single girl” sings. But because Amish worship is performed in private homes instead of public churches, few outsiders get the chance to hear Amish people sing. Amish music also remains largely unexplored in the field of ethnomusicology. In Why the Amish Sing, D. Rose Elder introduces readers to the ways that Amish music both reinforces and advances spiritual life, delving deep into the Ausbund, the oldest hymnal in continuous use. This illuminating ethnomusicological study demonstrates how Amish groups in Wayne and Holmes Counties, Ohio—the largest concentration of Amish in the world—sing to praise God and, at the same time, remind themselves of their 450-year history of devotion. Singing instructs Amish children in community ways and unites the group through common participation. As they sing in unison to the weighty words of their ancestors, the Amish confirm their love and support for the community. Their singing delineates their common journey—a journey that demands separation from the world and yielding to God's will.By making school visits, attending worship services and youth sings, and visiting private homes, Elder has been given the rare opportunity to listen to Amish singing in its natural social and familial context. She combines one-on-one interviews with detailed observations of how song provides a window into Amish cultural beliefs, values, and norms

Results of an investigation of hypersonic viscous interaction effects of the space shuttle orbiter using a 0.010 scale model (51-0) in the AEDC-VKF tunnel F (OA160)

An experimental aerodynamic investigation was conducted in the AEDC-VKF Hypervelocity Wind Tunnel (Tunnel F) at a nomial Mach number of 19 to determine hypersonic viscous interaction effects on the space shuttle orbiter. The tests were conducted at an angle of attack of 30 degrees over a free-stream Reynolds number (based on fuselage length) variation from 0.1 to 0.4 million. Viscous interaction parameter was varied from 0.02 to 0.06. Six component static stability force and moment data were measured by an internally compensated internal strain gage balance. Resulting data are presented

Community Service and Public Health: The Jefferson Health System

No abstract available

The Application of Molecular Orbital Calculations to Wood Chemistry. II. The Protonation of Beta-Methyl Glucopyranoside

The protonation step in the acid hydrolysis reaction of beta-methyl glucopyranoside was studied by molecular orbital techniques. The semi-empirical, self-consistent fields method of modified neglect of diatomic overlap (MNDO) was used to calculate energetic and electronic information in an attempt to determine the site of initial protonation

STORYTELLING SONGS OF THE ÈWÈ-DÒMÈ OF GHANA

For the Central Èwè or Èwè-Dòmè people of Ghana’s Volta Region, storytelling is a vital practice used to transmit key lessons. For centuries the Èwè-Dòmè employed storytelling performances in initiation rites, war celebrations, wake-keeping, and praise singing to enrich the gathering by relaying important information, building group identity, and binding the community together with story, song, and dance. Storytellers and community participants point to the role that songs play within storytelling as cultural markers for the Èwè-Dòmè communities in the area around Ho, the Volta Region’s capital. Within the framework of extended family or town-wide storytelling performances, audience members habitually interrupt the story with song and dance that enlivens sleepy listeners and augments the story with an interpretive angle on the theme. Singing reverses the artist-audience roles. Other community events similarly provide an opportunity for artist-audience interaction and the reversal of roles. This paper documents the social role of songs in the context of storytelling as well as the performance practices, texts, melodies, rhythms, and harmonies of this important traditional musical genre in the face of numerous threats to its ongoing existence