Growth of Oxide Compounds under Dynamic Atmosphere Composition

Commercially available gases contain residual impurities leading to a background oxygen partial pressure of typically several 10^{-6} bar, independent of temperature. This oxygen partial pressure is inappropriate for the growth of some single crystals where the desired oxidation state possesses a narrow stability field. Equilibrium thermodynamic calculations allow the determination of dynamic atmosphere compositions yielding such self adjusting and temperature dependent oxygen partial pressures, that crystals like ZnO, Ga2O3, or Fe{1-x}O can be grown from the melt.Comment: 4 pages, 3 figures, talk on CGCT-4 Sendai, May 21-24, 200

Intrinsic and Extrinsic Performance Limits of Graphene Devices on SiO2

The linear dispersion relation in graphene[1,2] gives rise to a surprising prediction: the resistivity due to isotropic scatterers (e.g. white-noise disorder[3] or phonons[4-8]) is independent of carrier density n. Here we show that acoustic phonon scattering[4-6] is indeed independent of n, and places an intrinsic limit on the resistivity in graphene of only 30 Ohm at room temperature (RT). At a technologically-relevant carrier density of 10^12 cm^-2, the mean free path for electron-acoustic phonon scattering is >2 microns, and the intrinsic mobility limit is 2x10^5 cm^2/Vs, exceeding the highest known inorganic semiconductor (InSb, ~7.7x10^4 cm^2/Vs[9]) and semiconducting carbon nanotubes (~1x10^5 cm^2/Vs[10]). We also show that extrinsic scattering by surface phonons of the SiO2 substrate[11,12] adds a strong temperature dependent resistivity above ~200 K[8], limiting the RT mobility to ~4x10^4 cm^2/Vs, pointing out the importance of substrate choice for graphene devices[13].Comment: 16 pages, 3 figure

SULLE PECULIARITÀ DEL SISTEMA SEGNICO MIMICO-GESTUALE

La persona sorda non sente il mondo intorno a sé, bensì lo guarda e non può perciò rappresentarlo con la voce, organo strettamente dipendente dall’udito, ma può invece rappresentarlo con i gesti e con la mimica. Il mondo, sia quello circostante che quello interiore, si costituisce per la persona sorda mediante il canale visivo e si articola dunque in segni mimico-gestuali piuttosto che vocali. La peculiarità del sistema mimico-gestuale si misura sulla base dell’analisi dei quattro parametri manuali (il luogo dello spazio in cui avviene la configurazione manuale, la configurazione e il movimento delle mani, l’orientamento del palmo delle mani) e delle componenti non manuali di cui esso si compone. Ciascun segno si distingue da un altro per differenze oppositive tra uno o più di questi elementi che lo compongono. La struttura oppositiva che caratterizza la lingua delle persone sorde differisce in quanto la lingua dei sordi sfrutta il canale visivo anziché quello uditivo e si costituisce nella materia manuale, gestuale quindi, anziché in quella fonica. Nella costituzione del segno delle persone sorde, inoltre, le componenti non manuali non sono semplici elementi paralinguistici che accompagnano la semiosi enfatizzandola, come per le lingue vocali, bensì sono veri e propri elementi costitutivi del segno la cui carenza compromette la comprensione reciproca

More Than Our Share: The Unchecked HIV/AIDS Crisis in Mississippi

This presentation describes the unmet needs of people living with HIV/AIDS in the rural south (specifically Mississippi) in light of the inequity in the distribution of federal funds to rural states. Participants will understand the the reciprocal influences of these needs and HIV as well as the need for policy changes at the state and federal levels

More Than Our Share: The Unchecked HIV/AIDS Crisis In Mississippi

Rich and varied cultures as well as rich and varied geography make Mississippi a charming state. Mississippi has provided the world with talented musicians, gifted authors, and many creative individuals who have shaped American culture. There is beauty in the century-old oaks trees, power in the mighty Mississippi River, excitement in the sun and sand of the gulf coast, and grace in the abundance of fragrant azalea bushes. Underneath the veneer of southern gentility and beauty, however, there is a tangled and disparaging world of hardship and disparity. There are layers of dark history that have left deep gouges in the metaphorical landscape and continue to impact much of everyday life for the residents of the state. The horrors of slavery and segregation still echo throughout Mississippi, and prevailing conservative Christian values have profound effects on social welfare policy. Meanwhile, modern societal problems such as extreme poverty, racism, and substandard education tear at the fabric of Mississippi society. Mississippi’s place as last in the country in almost every socioeconomic category causes and exacerbates a host of deeper issues, and chief among them is the HIV/AIDS crisis, one of Mississippi’s deadliest and yet most ignored problems

Five Years Later: Resiliency Among Older Adult Survivors of Hurricane Katrina

The purpose of this study was to examine the resilience of older adult survivors of Hurricane Katrina in light of their traumatic experiences and multiple losses. Ten Mississippi Gulf Coast residents who have survived Hurricane Katrina and its aftermath were interviewed. The participants were 65 years old or older. Their responses were audiotaped and transcribed. The transcripts were analyzed using phenomenological methodology and NVivo 2.5 software. Three major themes emerged. Participants described finding personal gratification, realizing their ability to cope, and developing a new interest in life through their novel experiences. © 2012 Copyright Taylor and Francis Group, LLC

The Unchecked HIV/AIDS Crisis in Mississippi

While the population of the southern United States is only 37% of the country’s total, this region is experiencing 50% of new HIV diagnoses and 46% of new AIDS diagnoses. Specifically, Mississippi has the highest rates of new infection, the most AIDS deaths, the greatest number of people living with HIV/AIDS, and the fewest resources. Mississippi has the highest death rate in the country: 32.9 per 1,000. A Mississippian with HIV/AIDS is almost twice as likely to die as the average American with the virus (SHARP Report, 2010). Compounding the problem are government policy issues, such as disproportionate program funding; socio-economic issues, such as widespread poverty, housing insecurity, and the lack of access to care; and cultural issues, such as homophobia and social stigma. These factors are reflected in this study which examines the needs of people living with HIV/AIDS in a southern, rural county of Mississippi. From a representative sample of 218 HIV positive individuals, researchers identified the levels of need for housing, transportation, medical care, mental health care, substance abuse treatment, and education. The author discusses the reciprocal influences of these needs and HIV, the need for policy changes at the state and federal levels, and the need for resources that both support people living with HIV/AIDS and curb the rate of new infections

Creating Macro Social Work Field Placements Through a University Campus Social Justice Issue

Providing hands-on experiential learning opportunities to supplement hypothetical classroom lessons involving macro social work often presents challenges for educators. Applying theoretical lessons to real-world settings has the potential to significantly boost student critical thinking and problem-solving capabilities. Skill acquisition in these settings can help create job-ready graduates who apply for management or leadership positions. This article provides an overview of a social work field placement setting developed on a university campus in the U.S. Deep South. The mission of the field placement program is to address the needs of underserved students, staff, and faculty who were experiencing food insecurity or who lacked other vital resources. Lessons learned by graduate students along with implications for social work education are provided