Flash column chromatography is a quick and (usually) easy way to separate complex mixtures of compounds. We will be performing relatively large scale separations in 5.301,around 1.0 g of compound. Columns are often smaller in scale than this and some of you will experience these once you move into the research lab. Column chromatography uses the same principles

Introduction Are people unaffected by tax increase if they pay zero in taxes afterwards? No, consumption may have changed in response to the tax increase Bundle consumed is less desirable Excess burden is a loss of welfare above and beyond the tax revenues collected

In this lecture, we consider the problem of a body in which the mass of the body changes during the motion, that is, m is a function of t, i.e. m(t). Although there are many cases for which this particular model is applicable, one of obvious importance to us are rockets. We shall see that a significant fraction of the mass of a rocket is the fuel, which is expelled during flight at a high velocity and thus, provides the propulsive force for the rocket

In this lecture, we will consider how to transfer from one orbit, or trajectory, to another. One of the assumptions that we shall make is that the velocity changes of the spacecraft, due to the propulsive effects, occur instantaneously. Although it obviously takes some time for the spacecraft to accelerate to the velocity of the new orbit, this assumption is reasonable when the burn time of the rocket is much smaller than the period of the orbit. In such cases, the Av required to do the maneuver is simply the difference between the

I. Revision Teacher uses the following exercise to help the students to revise the important expressions or phrases or sentences which were learnt in the loud speaker, study of last unit eacher: When I say a phrase or an expression in Chinese, you respond by blackboard

1. what have we learned in the Unit projector, Possible answers: cellular Mobile Telephone System 2. What is cellular Mobile Telephone System? loud speaker Possible answers: to reuse the allocated frequency band in different geographic locations blackboard

1. to know the three basic processes of PCM: Sampling Quantizing Encoding Teaching 2. to understand that PCM is the heart of technology in communications in Objectives

Chapter6 Transaction behavior on the internet 6.1 consumer buying behavior 6. 1. 1 What is Consumer Buying Behavior Buying Behavior is the decision processes and acts of people involved in bu product Need to understand why consumers make the purchases that they make? what factors influence consumer purchases? the changing factors in our society

An introduction to biotechnological innovations in the chemical industry 1.1 Introduction 1.2 Production processes 1.3 Choice of production process

Why is the element stiffness matrix singular in a finite element formulation? 1. So that it can accomodate rigid element dis- placements without introducing spurious nodal 2 Because we made a mistake in the formula- tion the stiffness matrix should not be sin- g 3. Because we havent enforced any displace ment boundary conditions(it's a variational approach after all) Statement(1)