2000 B.C - The first recorded (The Susruta Samhita, Sanskrit writing) water purification began with the Egyptians. It is said that impure water should be boiled over a fire, heated in the sun, have a hot iron dipped into it or purified by filtration through sand and course gravel.
A major step in the development of desalination technologies came in the 1940s during World War II when various m
1. Introduction
1) Definition of preservation and food-spoilage micro-organisms
Food preservation is the process of treating and handling food to stop or greatly slow down spoilage (loss of quality, edibility or nutritive value) caused or accelerated by micro-organisms. Some methods, however, use benign bacteria, yeasts or fungi to add specific qualities and to preserve food (e.g., cheese, wine
Flow around and through fish gills
Jeesoon Choi and Dongyeop Baek
School of Mechanical and Aerospace Engineering, Seoul National University
Abstract. An overall view of the flow over the fish gills is first described by using the active pump system and the passive ram ventilation. The concept of ram ventilation is introduced and its merits of reducing hydrodynamic drags and efficient e
1. 서 론
인공투석이란 신장이 그 기능을 충분히 발휘하지 못할 때 인공적으로 혈액중의 노폐물을 제거하여 깨끗한 혈액으로 바꾸어 내보내는 방법이다. 신장은 과잉 섭취된 물과 단백질 대사 결과 생성되는 질소 대사 노폐물을 분비하고, 혈장의 산·염기 평형과 전해질 농도를 조절하며, 내분비기능