STM and RHEED study of the Si(001)-c(8x8) surface

The Si(001) surface deoxidized by short annealing at T~925C in the ultrahigh vacuum molecular beam epitaxy chamber has been in situ investigated by high resolution scanning tunnelling microscopy (STM) and reflected high energy electron diffraction (RHEED). RHEED patterns corresponding to (2x1) and (4x4) structures were observed during sample treatment. The (4x4) reconstruction arose at T<600C after annealing. The reconstruction was observed to be reversible: the (4x4) structure turned into the (2x1) one at T>600C, the (4x4) structure appeared again at recurring cooling. The c(8x8) reconstruction was revealed by STM at room temperature on the same samples. A fraction of the surface area covered by the c(8x8) structure decreased as the sample cooling rate was reduced. The (2x1) structure was observed on the surface free of the c(8x8) one. The c(8x8) structure has been evidenced to manifest itself as the (4x4) one in the RHEED patterns. A model of the c(8x8) structure formation has been built on the basis of the STM data. Origin of the high-order structure on the Si(001) surface and its connection with the epinucleation phenomenon are discussed.Comment: 26 pages, 12 figure

Envelhecimento, estratégias de enfrentamento do idoso e repercussões na família Envejecimiento, estrategias de afrontamiento de los ancianos y impactos en la familia Aging, facing strategies of the aged and the consequences for family

Trata-se de estudo qualitativo para conhecer a percepção de idosos, usuários de Unidade Básica de Saúde de São Paulo, sobre envelhecimento, estratégias de enfrentamento e repercussões na família. Foram realizadas, de setembro de 2007 a julho de 2008, entrevistas com três idosos, de 71 a 90 anos. Os participantes responderam às perguntas da Escala de Depressão Geriátrica, Ecomapa, Genograma e modelo Calgary. Com análise de conteúdo de Bardin, encontramos três categorias percebendo o momento do ciclo vital; sofrendo as repercussões deste momento; enfrentando o envelhecimento e a velhice. Acreditamos na continuidade de estudos que busquem estratégias com idosos e famílias na tentativa de melhorar a qualidade de vida e dinâmica familiar com inclusão de entretenimento, segundo possibilidade da comunidade.<br>El siguiente estudio cualitativo busca comprender la percepción de las personas de edad avanzada, usuarios de la Unidad Básica de Salud de São Paulo, en cuanto al envejecimiento, estrategias de afrontamiento y el impacto en la familia. Se hicieron entrevistas desde Septiembre del 2007 hacia Julio del 2008 con tres personas mayores, de los 71 a 90 años. Los participantes contestaron a las preguntas de la Escala de Depresión Geriátrica, Ecomapa, Genograma y modelo Calgary. A través del análisis de Bardin, hemos descubierto tres categorías - el momento de darse cuenta del ciclo de la vida; se sufren las consecuencias de ese momento; se enfrentan el proceso de envejecimiento y la vejez. Creemos en la continuidad de los estudios que buscan estrategias con las personas mayores y sus familias para mejorar la calidad de vida y la dinámica familiar a través de la inclusión del entretenimiento, acuerdo a las posibilidades ofrecidas a la comunidad.<br>This qualitative study seeks the understanding of the perception of the elderly, users of Basic Health Unit of São Paulo, on aging, coping strategies and impact on family. Interviews with three elderly people, from 71 to 90 years-old, were held from September 2007 to July'2008. Participants responded to questions under the Geriatric Depression Scale, Ecomapa, Genogram and Calgary model. From the Bardin analysis, we could determine three categories - the moment of realizing the life cycle; suffering the consequences of this time; facing the aging and old age. We believe in the continuity of studies that search for strategies with older people and their families in an attempt to improve life quality and family dynamics by the inclusion of entertainment, according to the possibilities offered to their communities