422 research outputs found

    EVIDENCE OF WEAK CHAOS WITHIN PLUG-SLUG TRANSITION IN HORIZONTAL TWO PHASE FLOW

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    Intermittent behaviour has been observed in gas-liquid flows in a horizontal pipe and a weak sign of deterministic chaos has been diagnosed within a transition from plug to slug flow. The analysis has been performed on the basis of an algorithm which exploits the concept of short-term predictability of chaotic motions. The method is completely non-parametric and works whatever the distribution function of the data points may be. The weak sign of chaos is in contrast with the Lorenz-type systems (strong chaos) and supports the idea of Kolmogorov about irregular motion in hydrodynamical systems

    Shorter Exposures to Harder X-Rays Trigger Early Apoptotic Events in Xenopus laevis Embryos

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    A long-standing conventional view of radiation-induced apoptosis is that increased exposure results in augmented apoptosis in a biological system, with a threshold below which radiation doses do not cause any significant increase in cell death. The consequences of this belief impact the extent to which malignant diseases and non-malignant conditions are therapeutically treated and how radiation is used in combination with other therapies. Our research challenges the current dogma of dose-dependent induction of apoptosis and establishes a new parallel paradigm to the photoelectric effect in biological systems. embryo. Three different experimental scenarios were analyzed and morphological and biochemical hallmarks of apoptosis were evaluated. Initially, we examined cell death events in embryos exposed to increasing incident energies when the exposure time was preset. Then, we evaluated the embryo's response when the exposure time was augmented while the energy value remained constant. Lastly, we studied the incidence of apoptosis in embryos exposed to an equal total dose of radiation that resulted from increasing the incoming energy while lowering the exposure time. absorbed dose of radiation, the response is significantly increased when shorter bursts of more energetic photons are used. These results suggest that biological organisms display properties similar to the photoelectric effect in physical systems and provide new insights into how radiation-mediated apoptosis should be understood and utilized for therapeutic purposes

    Banner News

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    https://openspace.dmacc.edu/banner_news/1158/thumbnail.jp

    Acoustic and visual study of bubble formation processes in bubble columns staged with fibrous catalytic layers

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    High-speed images of bubbly flow coupled with simultaneous passive acoustic measurements were carried out in a bubble column staged with structured fibrous catalysts. Local observations made with a high-speed camera system allow a detailed understanding of the influence of fabric structure on bubble formation processes and the detn. of the Sauter bubble diam. With acoustic measurements, the building frequency of bubble swarm formation is identified to be a linear function of the superficial gas velocity. Due to bubble size and building frequency of bubble swarm the percentage of simultaneously operative sites (holes at which bubbles were formed simultaneously) is calcd. [on SciFinder (R)

    TRIPS implementation and secondary pharmaceutical patenting in Brazil and India

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    This article compares national approaches toward secondary pharmaceutical patents. Because secondary patents can extend periods of exclusivity and delay generic competition, they can raise prices and reduce access to medicines. Little is known about what measures countries have enacted policies to address applications for secondary pharmaceutical patents, how they function, and whether, in practice, these measures limit secondary patents. We analyze the cases of India and Brazil. We assemble data on pharmaceutical patent applications filed in the two countries, code each application to identify which constitute secondary applications, and examine outcomes for each application in both countries. The data indicate that Brazil is less likely to grant applications than India, but in both countries the measures designed to limit secondary patents are having little direct effect. This suggests, on the one hand, that critics of these policies, such as the transnational pharmaceutical sector and foreign governments, may be more worried than they should be. On the other hand, champions of the policies, such as NGOs and international organizations, may have cause for concern that laws on the books are not having the expected impact on patent outcomes in practice. Our findings also suggest that, at the drug level, the effects of countries’ approaches toward secondary patents need to be understood in the context of their broader approaches toward TRIPS implementation, including when and how they introduced pharmaceutical patents in the 1990s and 2000s
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