Skin-friction measurements in high-enthalpy hypersonic boundary layers

Skin-friction measurements are reported for high-enthalpy and high-Mach-number laminar, transitional and turbulent boundary layers. The measurements were performed in a free-piston shock tunnel with air-flow Mach number, stagnation enthalpy and Reynolds numbers in the ranges of 4.4-6.7, 3-13 MJ kg(-1) and 0.16 x 10(6)-21 x 10(6), respectively. Wall temperatures were near 300 K and this resulted in ratios of wall enthalpy to flow-stagnation enthalpy in the range of 0.1-0.02. The experiments were performed using rectangular ducts. The measurements were accomplished using a new skin-friction gauge that was developed for impulse facility testing. The gauge was an acceleration compensated piezoelectric transducer and had a lowest natural frequency near 40 kHz. Turbulent skin-friction levels were measured to within a typical uncertainty of +/-7%. The systematic uncertainty in measured skin-friction coefficient was high for the tested laminar conditions; however, to within experimental uncertainty, the skin-friction and heat-transfer measurements were in agreement with the laminar theory of van Driest (1952). For predicting turbulent skin-friction coefficient, it was established that, for the range of Mach numbers and Reynolds numbers of the experiments, with cold walls and boundary layers approaching the turbulent equilibrium state, the Spalding & Chi (1964) method was the most suitable of the theories tested. It was also established that if the heat transfer rate to the wall is to be predicted, then the Spalding & Chi (1964) method should be used in conjunction with a Reynolds analogy factor near unity. If more accurate results are required, then an experimentally observed relationship between the Reynolds analogy factor and the skin-friction coefficient may be applied.

Estimates of global and regional potential health gains from reducing multiple major risk factors

Background Estimates of the disease burden due to multiple risk factors can show the potential gain from combined preventive measures. But few such investigations have been attempted, and none on a global scale. Our aim was to estimate the potential health benefits from removal of multiple major risk factors. Methods We assessed the burden of disease and injury attributable to the joint effects of 20 selected leading risk factors in 14 epidemiological subregions of the world. We estimated population attributable fractions, defined as the proportional reduction in disease or mortality that would occur if exposure to a risk factor were reduced to an alternative level, from data for risk factor prevalence and hazard size. For every disease, we estimated joint population attributable fractions, for multiple risk factors, by age and sex, from the direct contributions of individual risk factors. To obtain the direct hazards, we reviewed publications and re-analysed cohort data to account for that part of hazard that is mediated through other risks. Results Globally, an estimated 47% of premature deaths and 39% of total disease burden in 2000 resulted from the joint effects of the risk factors considered. These risks caused a substantial proportion of important diseases, including diarrhoea (92%-94%), lower respiratory infections (55-62%), lung cancer (72%), chronic obstructive pulmonary disease (60%), ischaemic heart disease (83-89%), and stroke (70-76%). Removal of these risks would have increased global healthy life expectancy by 9.3 years (17%) ranging from 4.4 years (6%) in the developed countries of the western Pacific to 16.1 years (43%) in parts of sub-Saharan Africa. Interpretation Removal of major risk factors would not only increase healthy life expectancy in every region, but also reduce some of the differences between regions, The potential for disease prevention and health gain from tackling major known risks simultaneously would be substantial.

The Galilean turn in population ecology

The standard mathematical models in population ecology assume that a population's growth rate is a function of its environment. In this paper we investigate an alternative proposal according to which the rate of change of the growth rate is a function of the environment and of environmental change. We focus on the philosophical issues involved in such a fundamental shift in theoretical assumptions, as well as on the explanations the two theories offer for some of the key data such as cyclic populations. We also discuss the relationship between this move in population ecology and a similar move from first-order to second-order differential equations championed by Galileo and Newton in celestial mechanics.

Deviance and marginal occupations: the case of taxi drivers

The taxi industry provides a strategic site to explore workplace deviance in low supervision, low status, occupational settings. Despite this theoretical opportunity and the objective importance of the taxi industry worldwide, very little is known about deviance among taxi drivers. Making use of interview data, this exploratory study maps out forms of workplace deviance and the explanations given for them by a sample of male taxi drivers. Major illegal activities reported included speeding, driving unsafe vehicles, taking drugs, and fraud. Theories pertaining to worker alienation, stress management, victim precipitation, and social control were relevant to the rationalizations some of the drivers provided to account for their illegal behaviors. We conclude that the occupational culture of taxi drivers and the structure of the taxi industry facilitate the forms of deviance reported here.

Caenorhabditis elegans mutants resistant to phosphine toxicity show increased longevity and cross-resistance to the synergistic action of oxygen

Phosphine (hydrogen phosphide, PH3) is the fumigant most widely used to protect stored products from pest infestation. Despite the importance of this chemical, little is known about its mode of action. We have created three phosphine-resistant lines (pre-1, pre-7, pre-33) in the model organism C. elegans, with LC50 values 2, 5, and 9 times greater than the fully susceptible parental strain. Molecular oxygen was shown to be an extremely effective synergist with phosphine as, under hyperoxic conditions, 100% mortality was observed in wild-type nematodes exposed to 0.1 mg/l phosphine, a nonlethal concentration in air. All three mutants were resistant to the synergistic effects of oxygen in proportion to their resistance to phosphine with one mutant, pre-33, showing complete resistance to this synergism. We take the proportionality of cross-resistance between phosphine and the synergistic effect of oxygen to imply that all three mutants circumvent a mechanism of phosphine toxicity that is directly coupled to oxygen metabolism. Compared with the wild-type strain, all three mutants have an extended average life expectancy of from 12.5 to 25.3%. This is consistent with the proposed involvement of oxidative stress in both phosphine toxicity and ageing. Because the wild-type and mutant nematodes develop at the same rate, the longevity is unlikely to be caused by a clk-type reduction in oxidative metabolism, a potential alternative mechanism of phosphine resistance.

Clinical and economic impact of exercise electrocardiography and exercise echocardiography in clinical practice

Background Patients with known or suspected coronary disease are often investigated to facilitate risk assessment. We sought to examine the cost-effectiveness of strategies based on exercise echocardiography and exercise electrocardiography. Methods and results We studied 7656 patients undergoing exercise testing; of whom half underwent exercise echocardiography. Risk was defined with the Duke treadmill score for those undergoing exercise electrocardiography alone, and by the extent of ischaemia by exercise echocardiography. Cox proportional hazards models, risk adjusted for pretest likelihood of coronary artery disease, were used to estimate time to cardiac death or myocardial infarction. Costs (including diagnostic and revascularisation procedures, hospitalisations, and events) were calculated, inflation-corrected to year 2000 using Medicare trust fund rates and discounted at a rate of 5%. A decision model was employed to assess the marginal cost effectiveness (cost/life year saved) of exercise echo compared with exercise electrocardiography. Exercise echocardiography identified more patients as low-risk (51% vs 24%, p<0.001), and fewer as intermediate- (27% vs 51%, p<0.001) and high-risk (22% vs 4%); survival was greater in low- and intermediate- risk and less in high-risk patients. Although initial procedural costs and revascularisation costs (in intermediate- high risk patients) were greater, exercise echocardiography was associated with a greater incremental life expectancy (0.2 years) and a lower use of additional diagnostic procedures when compared with exercise electrocardiography (especially in lower risk patients). Using decision analysis, exercise echocardiography (Euro 2615/life year saved) was more cost effective than exercise electrocardiography. Conclusion Exercise echocardiography may enhance cost-effectiveness for the detection and management of at risk patients with known or suspected coronary disease. (C) 2003 Published by Elsevier Science Ltd on behalf of The European Society of Cardiology.

Writing the body of the mother: Narrative moments in Tsushima Yuko, Ariyoshi Sawako and Enchi Fumiko

This discussion argues the transformative potential inherent in the corporeal experience of motherhood as represented in selected textual moments of Japanese narrative. Narratives that address the experiences of the body of the mother are informed and given substance by an intense physicality, and thus have the potential to contest processes of social inscription in addition to suggesting alternative possibilities for all readers, not just those occupying an embodied maternal space. The discussion features brief events from the work of three writers who have written as mothers: Tsushima Y(u)macrko, Ariyoshi Sawako and Enchi Fumiko. In Yama o hashiru onna (1980; translated as Woman Running in the Mountains, 1991), Tsushima Y(u)macrko invites the reader to consider the embodied response to light of Takiko, a young pregnant woman. Emiko, the protagonist of Hishoku (Without Colour, 1967) by Ariyoshi Sawako, is the Japanese wife of an African American and has just given birth to a child. The daughter protagonist in Enchi Fumiko's 'Kami' ('Hair', 1957) operates a hairdressing business that is viable only with her mother's unpaid labour. The narratives are read through a matrix of post-structuralist theories of embodiment, drawing on the work of writers such as Julia Kristeva, Luce Irigaray and Elizabeth Grosz.

Review of time-domain polarization measurements for assessing insulation condition in aged transformers

This paper presents a review of the time-domain polarization measurement techniques for the condition assessment of aged transformer insulation. The polarization process is first described with appropriate dielectric response theories and then commonly used polarization methods are described with special emphasis on the most widely used return voltage(rv) measurement. Most recent emphasis has been directed to techniques of determining moisture content of insulation indirectly by measuring rv parameters. The major difficulty still lies with the accurate interpretation of return voltage results. This paper investigates different thoughts regarding the interpretation of rv results for different moisture and ageing conditions. Other time domain polarization measurement techniques and their results are also presented in this paper.

Water table waves in an unconfined aquifer: Experiments and modeling

[1] Comprehensive measurements are presented of the piezometric head in an unconfined aquifer during steady, simple harmonic oscillations driven by a hydrostatic clear water reservoir through a vertical interface. The results are analyzed and used to test existing hydrostatic and nonhydrostatic, small-amplitude theories along with capillary fringe effects. As expected, the amplitude of the water table wave decays exponentially. However, the decay rates and phase lags indicate the influence of both vertical flow and capillary effects. The capillary effects are reconciled with observations of water table oscillations in a sand column with the same sand. The effects of vertical flows and the corresponding nonhydrostatic pressure are reasonably well described by small-amplitude theory for water table waves in finite depth aquifers. That includes the oscillation amplitudes being greater at the bottom than at the top and the phase lead of the bottom compared with the top. The main problems with respect to interpreting the measurements through existing theory relate to the complicated boundary condition at the interface between the driving head reservoir and the aquifer. That is, the small-amplitude, finite depth expansion solution, which matches a hydrostatic boundary condition between the bottom and the mean driving head level, is unrealistic with respect to the pressure variation above this level. Hence it cannot describe the finer details of the multiple mode behavior close to the driving head boundary. The mean water table height initially increases with distance from the forcing boundary but then decreases again, and its asymptotic value is considerably smaller than that previously predicted for finite depth aquifers without capillary effects. Just as the mean water table over-height is smaller than predicted by capillarity-free shallow aquifer models, so is the amplitude of the second harmonic. In fact, there is no indication of extra second harmonics ( in addition to that contained in the driving head) being generated at the interface or in the interior.

Believing is not enough: Predicting support for the NTEU on an Australian campus

Asurvey-based field study was conducted with 232 members and nonmembers of the National Tertiary Education Union to investigate the psychological processes underpinning union support. Drawing on value-expectancy models and social identity/self-categorisation theory, this study investigated the role that both individual and grouprelated factors play in predicting attitudinal and behavioural support for the union. Variables investigated included instrumental and ideological attitudes, perceptions of a normative climate of union-support, and perceptions of higher education being under threat. Further to support for previous findings for the role of instrumental and ideological attitudes it was found that the perceived workplace norm had the anticipated direct effect on behaviour and evaluation and also moderated the behavioural expression of ideological and instrumental attitudes. The perception of threat to employment and higher education also directly impacted on behaviour and moderated the behavioural expression of ideological beliefs. The implications of these findings for collective action research will he discussed.

O recorrente apelo das reformas gerenciais: uma breve compara????o

Reformas de corte gerencial n??o s??o uma novidade no Brasil e est??o condenadas a reaparecerem de forma recorrente, dado o incessante processo de renova????o das teorias de administra????o no setor privado. Dado permanente apelo que det??m junto ?? ??rea governamental, ?? natural que estejam continuamente sendo transplantadas para o setor p??blico com maior ou menor sucesso, conforme um conjunto de circunst??ncias e caracter??sticas. O trabalho busca fazer uma breve an??lise comparativa dos processos de transforma????es em determinadas pol??ticas de gest??o p??blica nos dois ciclos de reformas autodenominadas gerenciais ocorridas nos dois mandatos de Fernando Henrique Cardoso. O texto identifica contrastes em rela????o a aspectos do policy making process nos dois momentos, com ??nfase para os momentos relacionados com a forma????o da agenda, especifica????o de propostas e processos decis??rios. Na primeira parte s??o recuperadas algumas quest??es comuns a outro esfor??o de reforma ??? no caso a de 1967 ??? e na conclus??o, s??o feitos alguns coment??rios relacionados com o legado de reformas de cunho gerencial no contexto do governo atual.

Sobre as causas naturais que formam a base empírica do fenômeno dos turbilhões nas cosmogonias : dos pré-socráticos a René Descartes

Neste trabalho é apresentado um possível fundamento empírico para as teorias dos turbilhões que figuram em praticamente todas as teorias cosmogônicas dos pré-socráticos e mesmo presentes nas teorias de pensadores modernos como René Descartes e C. Huyghens.

A crise financeira de 2008 e seus impactos na economia brasileira: uma análise sob a perspectiva de Minsky

Diante do colapso financeiro de 2008, este trabalho retoma a teoria econômica proposta por Hyman P. Minsky com o objetivo de esclarecer as circunstâncias que propiciaram uma crise financeira tão profunda. A estrutura analítica de Minsky é marcada pela Hipótese da Instabilidade Financeira, a qual aponta para fatores endógenos ao próprio sistema capitalista como o principal causador de instabilidades financeiras. Este processo, caracterizado principalmente por um avanço desfavorável no nível de endividamento dos agentes, constrói um ciclo de estágios que pode se desenvolver para uma crise financeira ou um colapso sistêmico, definidos como “Momento Minsky” e “Colapso Minsky”. Este cenário descrito por Minsky, também analisado à luz de teorias mais recentes como as de Gary A. Dymski e Alessandro Vercelli, é conhecido por “ciclo minskyano”. Ao adotar estes preceitos da análise teórica de Minsky, é possível visualizar como o processo de desregulamentação e fragilização financeira dos Estados Unidos nas décadas de 1980 e 1990 proveram condições para a crise do subprime e, posteriormente, o colapso financeiro de 2008. De maneira similar, é possível observar que a análise teórica de Minsky também é aplicável à crise que afeta a economia brasileira no final de 2008. A fragilização financeira que se inicia no Brasil poucos anos antes da crise, acentuada no setor exportador de commodities, cria a condição para o “momento Minsky brasileiro”, demonstrando que apesar das falhas da análise teórica de Minsky, que supõe uma economia fechada com características da economia estadunidense, é possível visualizar uma relação de causa e efeito da recente crise financeira com a teoria minskyana.

Hibridizações curriculares nos cotidianos de uma escola de ensino médio: ou sobre a força dos jovens na invenção de uma vida bonita

O texto apresenta os percursos da investigação realizada numa escola pública de ensino médio do município de Santa Teresa, interior do Espírito Santo. Afirma que, nas ações e inventividades cotidianas dos sujeitos praticantes, são tecidos os processos curriculares que dão movimento à pesquisa, considerando esses praticantes como protagonistas das teoriaspráticas curriculares. Problematiza os modos de ser jovem ao discutir os processos de singularização que acontecem nas relações cotidianas, defendendo uma perspectiva teoricoepistemológica que considera os jovens como sujeitos híbridos que habitam entre-lugares culturais, impossibilitando sua localização em identidades idealizadas ou fixas. Aposta nas relações e criações cotidianas, nos movimentos e tessituras dos currículos que se dão em redes coletivas e compartilhadas de saberesfazessentidos, tecidas entre os jovenspraticantes, seus professores e demais habitantes dos cotidianos escolares para além das uniformidades, padronizações e hierarquias das políticas oficiais de currículos. Assume o processo de hibridação que acontece nessas relações, nas discussões ligadas às teoriaspráticas cotidianas e associa a educação e a produção curricular aos processos culturais mais amplos, reconhecendo os limites da criação de uma definição única e precisa de “currículo”. Nesse sentido, defende o fazer curricular como produção de sentidos, argumentando a favor da criação de currículos hibridizados que se constituem em meio a práticas culturais híbridas, onde os movimentos, usos e negociações devem ser considerados nos processos complexos que os constituem, em meio às criações anônimas que se proliferam nos cotidianos. Assume como opção teoricometodologicopolítica as pesquisas com os cotidianos, utilizando narrativastextuaisimagéticas produzidas nos diferentes contextos da pesquisa pelos praticantes. Evidencia, ainda, que a criação da tese se faz no próprio movimento da escrita, num processo de ficção, discutindo questões ligadas às juventudes, à educação profissionalizante, ao ensino médio, aos modos de pesquisa, às relações cotidianas, às redes de singularidades, aos currículos, aos modelos de escola, às magensnarrativas desses processos, entre outras, sem, no entanto, definir os limites desses campos enunciativos, compondo-se, numa mistura intrigante e complexa de sons, gostos, fazeres, dizeres e calares dos percursos de conhecer, compreendendo a maior “marca cotidiana do cotidiano”.

Processos de exclusão da/na escola no período da Primeira República (1889-1930) no Estado do Espírito Santo

O objetivo desta tese é analisar que práticas de tradução educacional foram feitas em relação às crianças e jovens excluídos da/na escola da Primeira República (1889-1930) no Estado do Espírito Santo. Período este em que a cultura ocidental, mais especificamente a europeia, exercia forte influência nas políticas de regulação e de emancipação do Brasil. Assim constando, na área educacional, muitas das experiências e teorias defendidas e socializadas na Europa foram traduzidas para o Brasil, e por extensão, para o Espírito Santo. Para compreender as traduções na área educacional, situada no contexto da modernidade é que se reportou a Boaventura de Sousa Santos, à luz das ferramentas disponíveis pela Sociologia das Ausências, pela Sociologia das Emergências, bem como o Trabalho de Tradução. A proposta de pesquisa está ancorada numa perspectiva qualitativa de base hermenêutica e, para construir a investigação, foram utilizadas fontes históricas bibliográficas e documentais. As fontes de investigação permitiram explicar parte das possíveis razões para as exclusões da escola ou defesas de segregação (exclusão na escola). Estas exclusões se concentram em torno de cinco tempos: 1909, 1917, 1923, 1924 e 1929. Nos anos de 1909 e 1924, disserta-se pela via educacional, sobre as práticas da área jurídica em relação aos órfãos. A Escola Normal do Espírito Santo, por sua vez, reproduzia a ideia de ordem ao atrelar a Pedagogia à educação cívica. Em 1917, a partir do episódio relativo a uma jovem, associada a um possível caso de loucura/alienação mental, é abordada a influência da área médica na área educacional, no Estado do Espírito Santo. Quanto à década de 20, existiu todo um discurso sobre o estudo da criança, na formação de educadores, como tentativa de apreender a totalidade do ser humano. Algumas práticas de tradução construtivas na área educacional foram evidenciadas, como por exemplo, quando o professor Elpídio Pimentel sugere que os educadores trabalhem com o que o aluno sabe ou poderá aprender. Ao final do trabalho, percebe-se que, muitas exclusões poderiam ter sido evitadas, mas para isso, a sociedade, os educadores teriam que ter adotado uma outra postura em relação às práticas de tradução: talvez uma menos idealizada e que valorizasse o que emergia de potencial nas realidades locais.