47,535 research outputs found
Public Comment on OMB Draft Risk Assessment Bulletin
The OIRA draft Risk Assessment Bulletin has worthy intentions and has stimulated useful review and discussion.; Most previous major documents in the development of the risk assessment field have been cited and used appropriately. In general, the formulation is too broad. The Revision should clarify the place of risk assessment as distinguished from hazard identification and from risk management.The category of "influential risk assessment" is unnecessary and confusing, and should be deleted. A single set of six standards would suffice, without the additional nine special standards for "influential risk assessments". Greater transparency within the EOP is desirable to give this process credibility and meet one of the explicit aims of the Bulletin. Finally, several omissions should be addressed: proactive engagement of stakeholders, public health context, deceptive use of quantitation, exclusion for research agencies, interagency steering committee and symmetry of risk assessment guidance for manufacturers as well as regulatory agencies.
Fertilization Narratives In The Art Of Gustav Klimt, Diego Rivera And Frida Kahlo: Repression, Domination And Eros Among Cells
Fertilization narratives are powerful biological stories that can be used for social ends, and 20th-century artists have used fertilization-based imagery to convey political and social ideas. In Danae, Gustav Klimt used an esoteric stage of early human embryos to indicate successful fertilization and the inability of government repression to stifle creativity. In Man, Controller of the Universe, Diego Rivera painted a mural of a man controlling an ovulating ovary, depicting Trotsky\u27s view that society will rationally regulate human fertilization. His former wife, Frida Kahlo, refuted this view in Moses: Nucleus of Creation, wherein she painted images of fertilization and embryo formation as the ultimate acts of erotic consummation and generation
Wall temperature jump in polyatomic gas flows
This article deals with the calculations of the temperature jump at the wall for gas flows in the slip regime. The analytical calculations are based on kinetic boundary conditions developed especially for polyatomic molecules. When compared to an expression previously obtained for unstructured molecules, the polyatomic molecule temperature jump reveals supplementary terms of bulk viscosity type due to the internal mode excitation. These terms may be important in high speed flows or in gas flows displaying significant relative density variation at the wall
Temperature jump and slip velocity calculations from an anisotropic scattering kernel
This article deals with the problem of temperature jump and slip velocity at the wall in gas/surface interaction. A consistent modelling of an impermeable surface involving an anisotropic scattering kernel developed in previous works is used to establish boundary conditions in unstructured molecule gas flows. Thus a temperature jump relation is derived in which the gas viscous effects at the wall and the mean velocity gradients appear. Likewise, a slip velocity relation is obtained in which both the slip coeffcient and the thermal creep coeffcient depend on the wall-to-gas temperature ratio. Moreover, both the temperature jump and the slip velocity relations involve not only one accommodation coeffcient as in usual expressions, but also the gas/surface information through the various (notably normal and tangential) accommodation coeffcients of the momentum components
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