NFPA's perspectives on performance-based codes and standards

Our ability to predict fire behavior and its effects on our lives has greatly improved over the past quarter century. Numerous scientific advancements have introduced new approaches and tools for the fire safety-related design of both the built environment and the development of new products. However, many of these new methods are not currently used on a routine basis.A growing number of individuals in the fire safety community think that our current fire safety design and approval process, coupled with the rigid make-up of our existing codes and standards, inhibit the greater application of these new methods. While many factors such as resistance to change and the potential misapplication of calculation tools, can account for this inhibiting effect, this paper focuses on the role of codes and standards and discusses how they might better serve the transfer and application of new technology.     

Runaway Electrons Pre-ionized Diffuse Discharges in SF6, Air,Argon and Nitrogen

The formation of runaway electron pre-ionized diffuse discharges at the pressures 0.05-0.7 MPa of in air, argon, nitrogen, and SF6 in an inhomogeneous electric field was investigated. Dynamics of intensity of the discharge plasma radiation from the different discharge gap regions in the gas pressure range （0.05-0.7 MPa） was established. It was shown that, the breakdown is occurred owing to the ionization wave, which starts from the electrode with small radius of curvature at both polarity of high voltage pulses. It is seen that formation of bright spots on the fiat electrode at the negative polarity of the electrode with small radius of curvature are observed during the changing of the discharge current polarity. It was shown that, at positive polarity of electrode with a small radius of curvature, the bright spots on the flat electrode arise due to the participation of the dynamic displacement current in the gap conductance.     

纳米流体驱提高原油采收率的三维孔隙尺度模拟

基于不同渗透率岩心的三维微观模型,采用流体体积法对纳米流体驱油进行数值模拟;利用实验测得的含SiO2纳米颗粒的悬浮液界面张力、接触角和黏度,针对质量分数为0～1％、具有不同粒径的SiO2纳米颗粒的水基悬浮液,研究了纳米颗粒质量分数和粒径、驱替液流速、原油黏度和岩心渗透率对纳米流体驱油效率的影响.研究表明:采收率随着颗粒...