Space power distribution system technology. Volume 2: Autonomous power management

Electrical power subsystem requirements, power management system functional requirements, algorithms, power management subsystem, hardware development, and trade studies and analyses are discussed

Space power distribution system technology. Volume 1: Reference EPS design

The multihundred kilowatt electrical power aspects of a mannable space platform in low Earth orbit is analyzed from a cost and technology viewpoint. At the projected orbital altitudes, Shuttle launch and servicing are technically and economically viable. Power generation is specified as photovoltaic consistent with projected planning. The cost models and trades are based upon a zero interest rate (the government taxes concurrently as required), constant dollars (1980), and costs derived in the first half of 1980. Space platform utilization of up to 30 years is evaluated to fully understand the impact of resupply and replacement as satellite missions are extended. Such lifetimes are potentially realizable with Shuttle servicing capability and are economically desirable

Participatory Action Research (PAR) in Middle School: Opportunities, Constraints, and Key Processes

Late childhood and early adolescence represent a critical transition in the developmental and academic trajectory of youth, a time in which there is an upsurge in academic disengagement and psychopathology. PAR projects that can promote youth’s sense of meaningful engagement in school and a sense of efficacy and mattering can be particularly powerful given the challenges of this developmental stage. In the present study, we draw on data from our own collaborative implementation of PAR projects in secondary schools to consider two central questions: (1) How do features of middle school settings and the developmental characteristics of the youth promote or inhibit the processes, outcomes, and sustainability of the PAR endeavor? and (2) How can the broad principles and concepts of PAR be effectively translated into specific intervention activities in schools, both within and outside of the classroom? In particular, we discuss a participatory research project conducted with 6th and 7th graders at an urban middle school as a means of highlighting the opportunities, constraints, and lessons learned in our efforts to contribute to the high-quality implementation and evaluation of PAR in diverse urban public schools

Degrees of choice

University or conservatoire? In recent years the provision of undergraduate music education at music colleges has undergone profound changes as conservatoires have reassessed their role within the education system. David Wright and Janet Ritterman offer two views of the choices and challenges facing the undergraduate college student

National review of orchestral provision Report of the consultation

SIGLEAvailable from British Library Document Supply Centre-DSC:GPE/4967 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Objective and subjective social class gradients for substance use among Mexican adolescents

This study examines the shape of social class gradients for substance use among Mexican adolescents. Substance use and objective and subjective indicators of social class were assessed in house-to-house surveys conducted with 7614 Mexican adolescents in 2004. The sample was designed to be representative of the poorest urban communities in seven Mexican states. The prevalence of current smoking was 16.8%, alcohol consumption was 30.2%, and drug use was 4.6%. Multiple logistic regressions are used to estimate the associations of objective indicators of socioeconomic status (SES) and subjective social status (SSS)--at both community and societal levels-and smoking, alcohol and drug use. Adolescents who perceived themselves as higher in social status in reference to their local community reported more smoking and drinking. Our findings were similar when we used objective measures of SES, such as maternal education and total monthly household expenditures per person. In contrast, adolescents who perceived that they had high social standing in reference to Mexican society as a whole were less likely to report being current smokers and drinkers. We found no significant association between social status and drug use. Research into how adolescents perceive themselves in reference to their peer communities may help strengthen programs and policies aimed at promoting health in vulnerable adolescent populations.Mexico Smoking Drinking Drug use Socioeconomic status (SES) Global health Poverty Subjective social status Adolescents