Physics 111 Advanced Laboratory. Professor Sumner Davis This video accompanies the Gamma Ray Spectroscopy Experiment, providing students with an introduction to the theory, apparatus, and procedures. The purpose of this experiment is to measure the mass attenuation coefficients of several materials using gamma ray sources. First you will perform some tests to show the effect of various equipment settings. You will then use the known sources to calibrate your detector, and verify the inverse square law. Finally, you will make some measurements that will allow you to calculate the mass attenuation coefficients for several materials at several energies. In this apparatus, the gamma rays enter a NaI scintillator crystal, which converts them into many lower energy photons. These photons travel through the crystal to the photocathode of a photomultiplier tube, where they are converted into electrons by means of the photoelectric effect. The photo-electrons are sent through a series of electrodes where the number of electrons is multiplied. At the anode, a pulse of current is produced, and then counted. http://advancedlab.org

Economic Geography of the Industrial World

Public health practitioners make urgent and important decisions in complex and uncertain environments, oftentimes using both intuitive and deliberative processes. When decisions are made in uncertain stressful, and high impact situations, even the most carefully planned deliberative processes depend on intuitive reactions drawn from collective experiences and values of the decision maker. In this video, Dr. Tomás Aragón talks about Continutious Decision Improvement (DCI) in the context of Public Health, balancing Intuitive and Deliberative processes with the Dual Process Model. An example of the CDI Process is demonstrated with the decision to Trust someone. Cal Prepare is a CDC Funded Preparedness Emergency Response Research Center (PERRC) at the University of California, Berkeley School of Public Health.

Legal Studies 103, 001 - Fall 2014 Theories of Law and Society - David Lieberman Creative Commons 3.0: Attribution-NonCommercial-NoDerivs