Steady non-ideal detonations in cylindrical sticks of expolsives

Numerical simulations of detonations in cylindrical rate-sticks of highly non-ideal explosives are performed, using a simple model with a weakly pressure dependent rate law and a pseudo-polytropic equation of state. Some numerical issues with such simulations are investigated, and it is shown that very high resolution (hundreds of points in the reaction zone) are required for highly accurate (converged) solutions. High resolution simulations are then used to investigate the qualitative dependences of the detonation driving zone structure on the diameter and degree of confinement of the explosive charge. The simulation results are used to show that, given the radius of curvature of the shock at the charge axis, the steady detonation speed and the axial solution are accurately predicted by a quasi-one-dimensional theory, even for cases where the detonation propagates at speeds significantly below the Chapman-Jouguet speed. Given reaction rate and equation of state models, this quasi-one-dimensional theory offers a significant improvement to Wood-Kirkwood theories currently used in industry

Genotype by Environment Interaction for Holstein Milk Yield in Colombia, Mexico, and Puerto Rico

Components of (co)variance and genetic parameters were estimated by REML procedures from first lactation mature equivalent Holstein milk records from 54,604 Colombian, Mexican, and Puerto Rican cows and 198,079 US cows. The objective was to determine the cause of heterogeneous daughter response to sire selection for milk yield between the regions. Data from Latin America were partitioned by country and by herd-year SD class for milk to obtain five joint analyses between the US and Latin America, low herd-year SD, high herd year SD, Colombia, and Mexico. Sire and residual variances for milk were 41 and 29% smaller in Latin America than in the US, 47 and 58% smaller for low than for high herd-year SD, and 31 and 49% smaller for Colombia than for Mexico. Resultant heritabilities ranged from .20 to .29. Genetic correlations for milk yield between the US and Latin America, low and high herd-year SD, Colombia, and Mexico were .91, .82, .89, .78, and .90. Expected correlated responses for milk in Latin America, low and high herd-year SD, Colombia, and Mexico were 70, 53, 79.56, and 78% of the direct response in the US. The scaling effects of heterogeneous variance resulted in smaller daughter milk responses in Latin America compared with the US even when herd-year SD was similar

Bronchoscopy-Derived Correlates of Lung Injury following Inhalational Injuries: A Prospective Observational Study

Background: Acute lung injury (ALI) is a major factor determining morbidity following burns and inhalational injury. In experimental models, factors potentially contributing to ALI risk include inhalation of toxins directly causing cell damage; inflammation; and infection. However, few studies have been done in humans. Methods: We carried out a prospective observational study of patients admitted to the NC Jaycees Burn Center who were intubated and on mechanical ventilation for burns and suspected inhalational injury. Subjects were enrolled over an 8-month period and followed till discharge or death. Serial bronchial washings from clinically-indicated bronchoscopies were collected and analyzed for markers of cell injury and inflammation. These markers were compared with clinical markers of ALI. Results: Forty-three consecutive patients were studied, with a spectrum of burn and inhalation injury severity. Visible soot at initial bronchoscopy and gram negative bacteria in the lower respiratory tract were associated with ALI in univariate analyses. Subsequent multivariate analysis also controlled for % body surface area burns, infection, and inhalation severity. Elevated IL-10 and reduced IL-12p70 in bronchial washings were statistically significantly associated with ALI. Conclusions: Independently of several factors including initial inhalational injury severity, infection, and extent of surface burns, high early levels of IL-10 and low levels of IL-12p70 in the central airways are associated with ALI in patients intubated after acute burn/inhalation injury. Lower airway secretions can be collected serially in critically ill burn/inhalation injury patients and may yield important clues to specific pathophysiologic pathways

Mensuração e Filosofia

Peirce earned his keep making measurements, mainly of gravity but also astronomical, and he made several contributions to the science of measurement. It has been said that his experience measuring had philosophical consequences: his adoption of fallibilism, his argument against necessitarianism, and his conception of inquiry as converging on the truth have all been mentioned. But not much attention has been paid to the curious episode of his making “the study of great men” part of a course in logic: students were asked to rank a long list of men by order of greatness. That was at Johns Hopkins in 1883. I shall argue that that study, together with his reflections on pre-instrumental estimates of stars” brightness, bears directly on the method of phaneroscopy formulated nearly two decades later. In each case, the problem is to show how objectivity is possible under conditions in which it must seem that objectivity is impossible.Peirce ganhou seu sustento fazendo mensurações, principalmente de gravidade, mas também mensurações astronômicas, dando várias contribuições à ciência da mensuração. Já se disse que sua experiência nessa área teve conseqüências filosóficas: sua adoção do falibilismo, seu argumento contra o necessitarismo e sua concepção da inquirição como convergência para a verdade foram todas mencionadas. Mas foi dada tanta atenção ao curioso episódio de ele ter feito de “o estudo dos grandes homens” uma parte de um curso de lógica: era pedido aos estudantes que classificassem uma longa lista de homens por ordem de grandeza. Isso aconteceu na Universidade Johns Hopkins em 1883. Defenderei que esse estudo, junto com suas reflexões sobre estimativas pré-instrumentais do brilho das estrelas, é diretamente relevante para o método da faneroscopia formulado aproximadamente duas décadas mais tarde. Em cada um dos casos, o problema é mostrar como a objetividade é possível sob condições em que é preciso parecer que a objetividade é impossível

Lendo Peirce de uma Maneira Diferente: Uma Resposta a David Dilworth

In response to criticism of an article on Peirce’s objective idealism, I raise a question about how the philosophical writings of Peirce should be read. Are writings widely separated in time to be read as developing different aspects of a single, comprehensive system, or are they, at least in some cases, to be read as trying out a sequence of alternative hypotheses? And how is that question to be resolved? And in which way did Peirce himself conceive of his philosophical work?Em resposta à crítica a um artigo sobre o idealismo objetivo de Peirce, levanto a questão sobre como os escritos filosóficos de Peirce devem ser lidos. São escritos amplamente separados pelo tempo para serem lidos como desenvolvendo aspectos diferentes de um sistema único, compreensível, ou devem, ao menos em alguns casos, serem lidos experimentando uma sequência de hipóteses alternativas. Como tal questão pode ser resolvida? E de que modo o próprio Peirce concebia seu trabalho filosófico