Friday, March 17, 2017

Spring 2017 CHEM 312: Lecture 12 Uranium Chemistry

Uranium chemistry is covered in this lecture with an emphasis on separations and synthesis for the nuclear fuel cycle. The solution chemistry of uranium is explored, focusing on uranyl. The molecular orbital of uranium is described. Separation of uranium by solvent extraction and ion exchange is presented. The enrichment of uranium from the uranium hexafluoride species is discussed, including diffusion, centrifuge, and laser methods. Oxide species of uranium are presented. Due to its potential as a nuclear fuel, the synthesis and properties of uranium metal and alloys are described in detail. With three different phase, the uranium metal exhibits more complex electronic behavior than the metals of the lighter actinides, a trend that continues to plutonium metal. The lecture is in two parts; part 1 is 50 minutes and part 2 is 30 minutes.  The lecture is assigned 16-Mar-17 and is due 26-Mar-17.

Monday, March 13, 2017

Spring 2017 CHEM 312: Radiochemistry laboratory tour Wednesday 15 March

For those interested, we will have visits to the UNLV radiochemistry laboratories this week.  We will have two meetings times on Wednesday 15 March, 1000 and 1130.  We will meet in the lobby of the HRC.  Each tour will be between 30 and 45 minutes.  

Spring 2017 CHEM 312: Lecture 11 Speciation

This lecture covers fundamentals of chemical kinetics and thermodynamics, mainly as a review. Thermodynamic laws, electrochemical reactions, and acid-base reactions are covered. The thermodynamic discussion relates to Gibbs free energy and equilibrium constants. Kinetic discussion related to its use in data analysis Emphasis of the lectures is applied to information useful for speciation modeling. Calculations and models for speciation are discussed. Equilibrium modeling using EXCEL and the program CHESS are presented. The lecture is 47 minutes.  The lecture is assigned 14-Mar-17 and due 19-Mar-17.

Wednesday, March 8, 2017

Spring 2017 CHEM 312: Lecture 10 Radiation Interactions

This lecture, in 2 parts, covers interaction of radiation with matter and includes fundamental interactions, particle ranges, dosimetry, and hot atom chemistry. Interaction of radiation with matter covers energy loss and reactions with charged particles and photons. The stopping power of charged particles in different material is covered, including calculations on energy loss with thickness. Electron backscattering is introduced with examples on different behavior with varied elements. Discussion on photon interaction includes photoelectric effect, Compton effect, and pair production. Units of dosimetry are described. Dosimetry measurements are discussed and quality factors based on particle mass and charge are introduced. Introductory dose calculations are supplied. Radiation protection regulations and the definition of terms (ALI, DAC) are given. A review of hot atom chemistry is given. Part 1 is 22 minutes, part 2 is 29 minutes. The lecture is assigned 9-Mar-17 and due 14-Mar-17.

Tuesday, March 7, 2017

Spring 2017 CHEM 312: Lecture 9 Nuclear Reactions

The lecture on nuclear reactions is presented in two parts. Nuclear reaction notation is introduced. The role of energetics in nuclear reactions is discussed and evaluated, including Q value, reaction barriers, and threshold energy. Center of mass and laboratory frames are discussed. The different processes involved in the formation of isotopes is provided including photonuclear processes. Reaction energetics, mechanisms and types are described. Nuclear reaction cross sections are described, with a presentation on values and limits given. This includes role of angular momentum in cross section values. The stellar production of elements is presented in terms of nuclear reactions. These provide the basis for understanding the formation of isotopes in stars. Part one is 26 minutes, part 2 is 34 minutes.  The lecture is assigned 7-Mar-17 and the PDF quiz is due 12-Mar-17.

Thursday, March 2, 2017

Spring 2017 CHEM 312: Exam 2

Exam 2
Assigned: 2 March 2017
Due: 7 March 2017                                                                      
2nd Due date:  10 March 2017
Lecture 4:  Alpha Decay
Lecture 5:  Beta Decay
Lecture 6:  Gamma Decay
Lecture 7:  Fission

Use lecture notes, textbooks, Chart of the Nuclides, Table of the Isotopes, and web pages.  Use the chart of the nuclides as your primary dataset for isotope half-life.   Submission of the work is not required for the 1st due date.  Show your work or references on a separate page and save electronically for the 2nd due date. 

There will be a skype meeting on the quiz on Tuesday 7 March at 1000 in the HRC 4th floor conference room.  

Please use 3 significant digits for your answers. 

For scientific notation please use X.XXEX (i.e, 1230 as 1.23E3).  This can be read by EXCEL as a number.  DO NOT use y.yyx10^y or y.yy*10^y.

Saturday, February 25, 2017

Spring 2017 CHEM 312: Lecture 8 Nuclear Force and Nuclear Models

This lecture provides information on nuclear force and nuclear models. The strong force is introduced through isospin. A comparison of exchange particles is provided. The use of mirror nuclei to examine the strong force is presented. An overview of nuclear potentials is provided and used to discuss the shell model. States of the shell model and their relationship to magic numbers are discussed. Use of the shell model is determine nuclide spin and parity is presented. The relationship between spin and parity with nuclear deformation is introduced with Nilsson diagrams. Additional information on Nilsson diagrams can be found in the Table of the Isotopes. An introduction of the Fermi model for energetic nuclei is given. The lecture length is 52 minutes.  The lecture is assigned 23-Feb-17 and due 5-Mar-17.