Steel is often used as an assembly of main structure such as columns and beams on external walls of buildings. Such steel structural members lose their structural function when the temperature of the steel rises due to spouting hot gas or radiation heating via openings, such as windows, upon fire in a neighboring compartment. This paper presents a calculation model for predicting temperature properties of steel structural members upon fire heating and proposes it as a practical tool for evaluation of fire resistance. Establishing a model of three-dimensional heat flow analysis is focused on considering a heat flow toward an axis of a member. Spouting hot gas and radiation heating through openings are taken into consideration as a heat source upon modeling. Firstly, spouting hot gas properties and radiation heating through openings were formulated in order to model their heating impact on temperature of members. Then a model of three-dimensional heat flow analysis (the model of calculating temperature), involving these results as main components, was created. This model also helps the practical prediction of temperature properties of steel structural members that local heating brings about.

No abstract

No abstract

SUMMARY Iris prolapse during intraocular surgery can be successfully prevented with the use of a simple iris protector made from a piece of polyethylene sheet. When employed during a peripheral iridotomy, the protector is particularly helpful in extracting dislocated lenses without causing vitreous loss.