Are hemispherical caps of boron-nitride nanotubes possible?

We report all-electron, density-functional calculations with large Gaussian polarization basis set of the recently synthesized octahedral B24N24 cage that is perfectly round by symmetry, and boron-nitride (BN) clusters that its existence might suggest. We consider whether it is energetically possible that the two halves of this round cage could cap the BN nanotubes, modeled by B28N28 and B32N32. The energetics show that BN nanotubes with such round caps, are only slightly less favorable than the BN clusters containing six squares as the only defects in the otherwise perfect hexagonal lattice. A larger B96N96 octahedral cage formed from B24N24 by adding sufficient hexagons to isolate all squares is not very favorable energetically. The squares protrude noticeably from its otherwise round surface.Comment: Uses elsart.cls (Elsevier Science), (Better pictures can be obtained from authors); Manuscript to appear in Chemical Physics Letter

Employment Program Models for People Experiencing Homelessness: Different approaches to program structure

Most individuals experiencing or at risk of homelessness want to work and a growing number of service providers and policymakers have taken notice. Although choosing the right employment program model can seem like a daunting task, research and wisdom from the field shows that multiple models have proven effective or promising in attaching the most disadvantaged jobseekers to work and helping them advance to employment options that meet their long-term needs and interests. Additionally, these models can be helpful in building upon existing skills or developing new skills necessary to enter and succeed in employment today. This best practice brief highlights what is known about these employment approaches to attachment and advancement, covering each model's purpose, elements, principles, funding, and research evidence, with examples from the field

Reflections

Postcard from Erin Dunlap, during the Linfield College Semester Abroad Program at Hong Kong Baptist University in Hong Kong, Chin

Employment Program Components: Considerations for Modifying Programming for People Experiencing Homelessness

Employment programs typically include assessment, job search assistance, work readiness training, occupational training, job placement, and retention services. Research and experience suggest that programs can best meet individual needs, strengths, and interests by modifying these elements to ensure flexible services that support each individual's personal and developmental needs as they transition to employment. This best practice brief highlights a menu of enhancements and examples that programs may consider in providing supportive, flexible services for individuals experiencing or at risk of homelessness

Service Delivery Principles and Techniques: Helping People Experiencing Homelessness Engage in Services and Succeed in Employment

Individuals experiencing or at risk of homelessness are motivated to engage in services, employment and other life changes at different times and in different ways. Understanding how to meet people where they are and help foster the process of change can bolster program successes with people experiencing homelessness

Populations Experiencing Homelessness: Diverse Barriers to Employment and How to Address Them

People experience homelessness for many reasons including financial insecurity, a lack of affordable housing, and difficulty accessing services such as medical care. Effective employment programs take special care when serving individuals facing these barriers. This best practice brief outlines the common employment barriers for these populations and provides considerations for tailoring employment services and prioritizing supportive services to best meet their needs

Adjustment and Developmental Outcomes of Students Engaged in Service Learning

In an effort to better understand the psychosocial and adjustment processes experienced by college students engaged in service learning, 22 randomly selected reflection journals were content-analyzed from a class of 44 child development students who had been engaged in service learning in a variety settings. Three of the themes that emerged in the journals involved students: feeling awkward during the first visits; feeling uncertain about redirecting children\u27s misbehavior; and having ambivalent feelings when bringing their service learning experiences to an end. The coping mechanisms and resources upon which students draw to successfully grow beyond these initial challenges are discussed, as well as practical suggestions for facilitators of the service learning experience