The atmosphere shields us from the sun's cancer-causing ultraviolet (UV) radiation and also moderates the earth's climate.
The atmosphere is obviously vital for human existence, but we have nevertheless been polluting it for years.
The atmosphere is obviously vital for human existence, but we have nevertheless been polluting it for years.
The atmosphere can be divided vertically into four m
High-Tech Textiles
1. Smart flame-resistant textile
1) 배경
IED(Improvised Explosive Deviced:급조폭발물)로 인한 사상자발생으로
화염방지의 필요성을 절감하였다.
2) Nomex®
듀퐁사에서 1960년대 초반에 개발한 Aromatic polyamid(aramid) fiber로 1967년부터 상업적으로 생산되기 시작. 지금은 화염방지 소재에 있어 하나의 명
Blackness. Then a hint of green becomes EARTH. It lies across an expanse of space. Richly colored. Fertile.
A GIGANTIC ASTEROID cuts into frame, Burning into EARTHS ATMOSPHERE and striking down in the currant area of Guzumel, Mexico.
Voice : An impact equivalent to ten thousand nuclear weapons detonating simultaneously.
A HUGE DINOSAUR FOOT steps down hard and is VAPORIZED with a deafening ROAR.
Ⅰ. 서론
1.1. 연구배경 및 목적
순철, 45C, 연강, 편상흑연주철, 구상흑연주철의 마운팅, 폴리싱, 부식, 사진현상 및 인화의 과정에 중점을 두고 각 시편의 금속조직을 관찰한다.
각종 재료로 제조된 부품의 외관 결함은 용이하게 발견할 수 있으나, 내부결함은 찾아내기가 용이하지 않다. 국산부
What is Amorphous metal?
Polycrystalline grains of varying shapes and sizes
Misaligned planes of atoms slip past each other easily, absorbing energy and allowing dislocations to move, making deformation permanent.
Grain boundaries represent weak spots
Also called Metallic glasses or glassy metals
Cooled faster than atoms can rearrange into a crystal.
Dislocation movement obstructed s