ASTM (American Society for Testing and Material)
역사와 특성 : 재료의 용도별, Test별 규격화를 통해 재료의 품질을 향상시키고 Maker와 User로 하여금 보다 손쉬운 재료의 선정과 취급을 유도하기 위한 목적으로 1898년에 설립.1995년 현재 132개의 위원회에서 매년 9500여개의 신규 Standard가 발행 또는 개정되고 있다.
idea behind the sonic resonance test method can be explained using the equation by which one can measure the propagating speed of flexural sonic wave through a medium
(1)
where v is the propagating speed of the flexural wave on a string, F is the tension applied to both sides of the string, P is the mass per unit length of the string.
Some methmatical manipulation of Eq (1) yields
flexure sensitivity (force or elasticity that bear in external force that nod some quality of the material or is curve . = bending strength) is lacking.
Iron frame concrete method of construction is making thereby.
Advantage of RC (Reinforced Concrete) structure is as following.
1) high economic performance
2) because resources expense is inexpensive than steel-frame structure) corrosion
is obtained through neuromarketing. Understanding how and why consumers feel various emotions is the most essential step for all marketing strategies, since they can turn out to be a great failure if customers do not empathize with them. In a sense, neuromarketing, dealing with emotions and subconscious of consumers, encompasses virtually all kinds of marketing trends to come in the future.
Ⅰ.질환
1.간암
간암이란 간의 대부분을 차지하는 간 세포에서 기원하는 악성 종양을 말한다. 넓은 의미로는 간에 생기는 모든 종류의 악성 종양(예를 들면 간내 담관암)이나 다른 기관의 암이 간에 전이되어 발생하는 전이성 간암까지도 포함하지만, 간세포암종이 간암 중 가장 흔하기 때문에 일반적