Estimation procedures to measure and monitor failure rates of components during thermal-vacuum testing

Estimation procedures are described for measuring component failure rates, for comparing the failure rates of two different groups of components, and for formulating confidence intervals for testing hypotheses (based on failure rates) that the two groups perform similarly or differently. Appendix A contains an example of an analysis in which these methods are applied to investigate the characteristics of two groups of spacecraft components. The estimation procedures are adaptable to system level testing and to monitoring failure characteristics in orbit

Where do Women Give Birth in Rural Tanzania?

Skilled birth attendance is one of the key factors in improving maternal and neonatal health but coverage is frequently less than 50% in many African and Asian countries, especially in rural areas. This article reports the findings on skilled birth attendance in a remote area with a large nomadic population in northern Tanzania. In a secondary analysis of data from a retrospective study on immunisation rates, data were compiled on the rates of skilled birth attendance at 8 mobile reproductive and child health clinics run by a rural first-referral hospital in the Mbulu area, covering the years 1998, 1999, 2006 and 2007. These data were analysed according to tribal affiliation and distance from health institutions with obstetric services. Based on 3851 data sets, average rates of skilled birth attendance were 27%, 24%, 28% and 30% in 1998, 1999, 2006 and 2007, respectively (p = 0.02). At individual clinics, rates could be as low as 5-10%. Only at one clinic, significant improvement occurred over time (p< 0.01). In the univariate analysis, affiliation to the Iraqw tribe was a strong predictor of higher rates of skilled birth attendance in comparison with the nomadic Datoga tribe for all years combined (odds ratio [OR] 2.43 [95% confidence interval {CI} 1.92-3.07]), whereas distance showed only a minor influence (OR 1.02 [95% CI 1.01-1.02]). In the multivariate analysis, only tribal affiliation in 2007 (OR 2.69 [95% CI 1.12-6.46]) and for all years combined (OR 1.65 [95% CI 1.04-2.61]) was a significant factor. This study documented lower than the national average rates of skilled birth attendance in a rural area in Tanzania, especially among the nomadic Datoga tribe, over several years. The effect of distance was not consistent. To increase rates of women giving birth with skilled attendance in rural, remote settings and in populations with large proportions of nomadic people, a multi-facetted approach involving education in and sensitisation for pregnancy- and delivery-related issues, support for planned and emergency transportation, and improved quality of obstetric and neonatal services needs to be explored

Decentralization in the EU Emissions Trading Scheme and Lessons for Global Policy

In 2005, the European Union introduced the largest and most ambitious emissions trading program in the world to meet its Kyoto commitments for the containment of global climate change. The EU Emissions Trading Scheme (EU ETS) has some distinctive features that differentiate it from the more standard model of emissions trading. In particular, it has a relatively decentralized structure that gives individual member states responsibility for setting targets, allocating permits, determining verification and enforcement, and making some choices about flexibility. It is also a “cap-within-a-cap,” seeking to achieve the Kyoto targets while only covering about half of EU emissions. Finally, it is a program that many hope will link with other greenhouse gas trading programs in the future—something we have not seen among existing trading systems. Examining these features coupled with recent EU ETS experience offers lessons about how cost effectiveness, equity, flexibility, and compliance fare in a multi-jurisdictional trading program, and highlights the challenges facing a global emissions trading regime.emissions trading, Kyoto Protocol, European Union, linking, climate change

Grave expectations : participatory greywater management in two Western Cape shack settlements

Includes bibliographical references (leaves 161-180).South Africa faces enormous challenges in the face of burgeoning urbanisation and the growth of underserviced shack settlements. Waste water disposal is but one of many aspects of basic services that are lacking. This anthropological dissertation is focused upon a Water Research Commission funded project, conducted by University of Cape Town academics from the departments of Civil Engineering, Social Anthropology and Environmental and Geographic Sciences, and carried out in two shack settlements in the Western Cape, South Africa. The project's aim was to engender community-level greywater management through participatory methods in the two shack settlements. The dissertation involves close analyses of participatory methods, the legislation and policy which governs service delivery to shack settlements in South Africa, and ethnographic accounts of shack settlement residents' experiences of service delivery. This information is compared with the assumptions upon which the project was predicated, to argue that the project's participatory aims were challenged from the outset by the political and socio-economic context within which the project was carried out. Moreover, in line with enduring criticisms of participatory development - in spite of a professed adherence to the methodologies - was unable to achieve its participatory goals

The impact of nebular emission on the broadband fluxes of high-redshift galaxies

A substantial fraction of the light emitted from young or star-forming galaxies at ultraviolet to near-infrared wavelengths comes from the ionized interstellar medium in the form of emission lines and a nebular continuum. At high redshifts, star formation rates are on average higher and stellar populations younger than in the local Universe. Both of these effects act to boost the impact of nebular emission on the overall spectrum of galaxies. Even so, the broadband fluxes and colours of high-redshift galaxies are routinely analyzed under the assumption that the light observed originates directly from stars. Here, we assess the impact of nebular emission on broadband fluxes in Johnson/Cousins BVRIJHK, Sloan Digital Sky Survey griz and Spitzer IRAC/MIPS filters as a function of observed redshift (up to z=15) for galaxies with different star formation histories. We find that nebular emission may account for a non-negligible fraction of the light received from high-redshift galaxies. The ages and masses inferred for such objects through the use of spectral evolutionary models that omit the nebular contribution are therefore likely to contain systematic errors. We argue that a careful treatment of the nebular component will be essential for the interpretation of the rest-frame ultraviolet-to-infrared properties of the first galaxies formed, like the ones expected to be detected with the James Webb Space Telescope.Comment: 5 pages, 3 figures, accepted for publication in ApJ

Die integrasie van humoristiese tekste by taalonderwys om studente se emosionele geletterdheid te ontwikkel: ’n gevallestudie

The integration of humorous texts in language education to develop students’ emotional literacy: a case study The integration of humorous material in language teaching can be instrumental in the development of emotional literacy, thereby fostering an aesthetic sensitivity in student teachers (as learners) in different social contexts. Texts containing humour can play a significant role in the development of learners’ understanding and appreciation of a language, as well as the cultural heritage it embodies. Furthermore, it offers learners the opportunity to become creatively and imaginatively involved with oral, visual and written texts. The article illustrates how the application of humorous material in the teaching of Afrikaans is not only rooted in responsive education, but complies with the objectives of the South African teaching policy documents. By concentrating on a literature review of research studies, the authors point out the correlation between humour and various factors that influence learners’ and students’ affective behaviour in the context of the language classroom. Particular reference is made to research results indicating that the use of humour induces a more positive attitude, while also motivating students (as learners) to participate constructively in language activities. Attention is also paid to the relationship between different personality types (based on cognitive style) and anxiety. Moreover, the established link between humour and anxiety justifies the inclusion of humorous texts to reduce language-related anxiety. Ultimately the research serves to support the authors’ argument in favour of incorporating humorous material in the teaching of Afrikaans, while several (practical) teaching strategies are suggested. The authors hope to enhance the educational value by pursuing a holistic approach to language teaching

Geothermal reservoir engineering research

The Stanford University research program on the study of stimulation and reservoir engineering of geothermal resources commenced as an interdisciplinary program in September, 1972. The broad objectives of this program have been: (1) the development of experimental and computational data to evaluate the optimum performance of fracture-stimulated geothermal reservoirs; (2) the development of a geothermal reservoir model to evaluate important thermophysical, hydrodynamic, and chemical parameters based on fluid-energy-volume balances as part of standard reservoir engineering practice; and (3) the construction of a laboratory model of an explosion-produced chimney to obtain experimental data on the processes of in-place boiling, moving flash fronts, and two-phase flow in porous and fractured hydrothermal reservoirs

Delaying the bell: the effects of longer school days on adolescent motherhood in Chile

We analyze the effect of a Chilean school reform that lengthened the school day from half to full-day shifts on the likelihood that adolescent girls become mothers. By increasing the number of hours spent in school, the reform curtails opportunities to engage in risky sexual behaviors. Using Chile's socio-economic household surveys and administrative data from the Ministry of Education from 19902006, we exploit the exogenous time and regional variation in the implementation of the reform to identify the effects of increased education and adult supervision on the likelihood that adolescent girls become mothers. We find that access to full-day schools reduces the probability of becoming an adolescent mother among poor families and in urban areas: an increase in full-day municipal enrollment of 20% reduces the likelihood of teen motherhood by 5%