Now or Never

돌비[bumping,突沸 ] 액체가 끓는점이 되어도 끓지 않고, 끓는점 이상으로 가열된 후에 충격을 받거나 이물질등이 첨가되어 갑자기 끓는 현상을 말한다. 이를 막기 위해서는 끓기 전에 액체와 기체가 많이 만날 수 있도록 구멍이 많이 난 물체등을 넣어 끓이거나 모세관으로 공기를 넣으면 된다. 튐이라고도 한다. 1기압에서 물을 가열하면 끓는점 100℃에서 물의 증기압도 1기압이 되므로 액체 표면 뿐 아니라 내부에서도 기화가 시작되어 비등이 일어난다. 그러나 용기 안을 깨끗하게 하고 서서히 가열하면 물의 온도가 100℃에 이르러도 끓지 않고 100℃ 이상이 되는 과열현상이 일어난다. 이 현상은 준안정 상태이므로 외부로부터의 충격이나 먼지가 들어가는 등의 원인으로 한번 기포가 생기기 시작하면 매우 큰 기포를 ..

Compare Alpha and Beta Glucose in the Chair Structures: The position of the -OH group on the anomeric carbon (#1) is an important distinction for carbohydrate chemistry. The Beta position is defined as the -OH being on the same side of the ring as the C # 6. In the chair structure this results in a horizontal projection. The Alpha position is defined as the -OH being on the opposite side of the ..

( Aqua regia or aqua regis (Latin for royal water or king's water) is a highly corrosive, fuming yellow or red solution, also called nitro-hydrochloric acid. The mixture is formed by freshly mixing concentrated nitric acid and concentrated hydrochloric acid, usually in a volumetric ratio of 1:3 respectively. It was named so because it can dissolve the so-called "royal metals," or noble metals, g..

The team examined leukaemia cells before (left) and after treatment Leukaemia cells 'killed quicker' The team examined leukaemia cells before (left) and after treatment Scientists have claimed to have found a way of killing leukaemia cells quicker and more effectively. The Simon Flavell Research Laboratory in Southampton used a compound from the common gypsophila plant to break down the membrane..

Definition of relative standard deviation : Same as coefficient of variation. The standard deviation is a measure of how precise the average is, or how well the numbers in a sequence agree or relate to each other. It is a measure of random error-the error not easily controlled, and is calculated as the sum of the differences between the numbers in a series from the average of those numbers divid..

If you are looking at purchasing an ELSD, you most likely have an analyte without chromaphoric properties. ELS detectors will detect any analyte that is not volatile at the temperatures required to volatilize the mobile phase. An ELSD will be more sensitive then a UV detector for compounds without chromaphores, but may be less sensitive then UV for chromaphoric analytes that are semi-volatile. L..

III.3.The detector’s time behaviour A detector’s time resolution is limited by its response to an instantaneous change of the input signal. Due to electrical capacities of the light sensitive element and the electronics, the output signal does not change instantaneously as well but gradually increases or decreases until it reaches its final value. The detector’s rise time is defined by the time ..

Chromatography forum은 최근에 알게된 아주 좋은 사이트이다. 전 세계 대학원생 + 연구원 + 심지어는 HPLC 책 저자 들이 다양한 질문에 다양한 답변을 해주는 곳이다. 마치 국내의 Bric과 비슷한 성격의 사이트라 하겠다. http://www.chromforum.org Triangular and "shark fin" shapes almost always indicate overload, and are often accompanied by a reduction in retention. You have already done the experiment to prove this - when you decrease concentration, the peak shape improves. I re..

*Indicates a definition adapted from: L.S. Ettre, Nomenclature for Chromatography, Pure Appl. Chem. 65: 819-872 [1993], © 1993 IUPAC; an updated version of this comprehensive report is available in the Orange Book, Chapter 9: Separations [1997] at: . Alumina A porous, particulate form of aluminum oxide [Al203] used as a stationary phase in normal-phase adsorption chromatography. Alumina has a hi..