Basic NMR Spectroscopy NMRTerminology The laboratory vs. rotating frame of reference Response of spins to pulsed magnetic field NMR pulse sequences The Fourier transform Measuring relaxation times 8. Imaging using the hack projection 9. Slice selection in MRI 10. Partial saturation Fourier transform imaging sequence I I . Imaging data and the iwo-dimensionalFourier transform 12. Additional MRI pulsesequences 13. l'hr magnetic resonance image 14. List oi rquations 15. Lirt of rrnding materials 1. 2. 3. 4. 5. 6. 7.
The package is suitable as a stand-alone teaching package or as part of a lecture presentation. Although the package was intended to introduce the principles of MRI, the first half is suitable for teaching the basics of modern NMR techniques. ~ a c k a e ehas been used at RIT at the underThis teachine-. graduate and introductory graduate levels with much success. Students may use the package a t RIT in our departmental computer room or check it out for use a t home. Students have found the seauences describine - the soin echo and two-dimensional Fourier transform imaging techniques esneciallvuseful. Thev have commented that the material is i k m e d i a k y comprehendible on viewing the sequences. From the instructor's point of view the time needed to explain the dynamic processes of MR is significantly reduced. The menu selection of topics allows the viewer to treat the material as a formal course by viewing topics in order or as a review by viewing individual topics. creation of this software was supported by the Rochester Institute of Technology under its productivity grant program. This software package is entitled "The Basics of NMR Imaging, A Computer Based Teaching Package" and is available from RIT Instructional Media Services for $50.
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EmerllencY Response J. Shofstahl, D. Jencen, G. Chansa, and J. Hardy The University of Akron Akron. OH 44325
Safetv in the chemical laboratorv is alwavs a concern. precautions to take ~ t u d e n i a a r einstructed as to the as to ~rotectiveclothine and safe handline of chemicals. ~ h e n ' s ~ e c i aprecautions l are required, this is also noted. However. i t is not alwavs oossible to nresent much information as to health hazids'and procedures in the event of a laree soill or fire. system has been developed t o provide information on over 1900 chemicals, mixtures, and general material classes in a form that is easy t o retrieve -and use. Students can rapidly locate hazard-related information on chemicals they will be using with little or no instruction. The system contains a range or information for each material where available and appropriate.
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Name and up to four synonyms Formula Description Chemleal and storage incompatibilities Chemical Ahslracta Registry number (CAS) NlOSH Remtryof Tonic Effects of ChemicalSubstances (RTECS) number Environmental Protection Agency (EPA) Hazsrdous Waste Codes Department of Transportation (DOT) Numbers and Guides National Fire Protection Association (NFPA) values for Health, Flammability, and Reactivity hazards. Physical properties including: weight, vapor pressure, melting paint, boiling point, flash point, explosive limits, and solubility. 648
Journal of Chemical Education
All information has been taken from the following standard sources on hazardous materials. NFPA No. 49-Hazardous Materials, 1975. DOT-P 58000.2-Hazardous Materials, Emergency Response Guidebook. 1980. DHEW ~ubiicationNo. 78-210-NIOSH Pocket Guidebook to Chemical Hazards, 1985. Federal Register, Vol. 45, No. 229. The student can locate a chemical based on names. formula, or registry numbers. Wildcards may be used tb locate materials based on oartial entries. Once an entrv has been identified, the data screen is displayed withalldaro pertainine to the chemiral. Svecific definitions for the NFPA haza& values and a compiete DOT Emergency Response Guide can be obtained with a single key stroke. The Emergency Response Guide gives the student a list of any health, fire, and explosive hazards and corrective actions they can take in the event of a spill or fire. A second benefit of the system is that i t provides a crossreference of the various reeistrv numbers assiened to a chemical. This should prove-usef;l to stockroom-personnel faced with the res~onsibilitvof hazardous waste dis~osal. The program is h i t t e n incompiled BASIC and runsonan 1BM PC (orcomvatible) withal least 512 K RAMand a hard disk containing at least 2.5 MB of free space. The system is distributed on either two 360 K 5 W n . disks or one 720 K 3'f2-in. disk. A copy of the system and the 63-page user manual may be obtained by sending $50 (to cover postage and duplication costs) to J. K. Hardy, Department of Chemistry, The University of Akron, Akron, OH 44325. Please specify the disk format desired.
An X-ray Diffraction Pattern Simulator Gonzalo Rodriguez and Silvlo Rodrfguez University of the Pacific Stockion. CA 95211 Most textbooks on experimental physical chemistry include the analysis of an X-ray powder diffraction pattern from which students determine the cubic lattice type and the lattice constant of a crystalline substance. The density of the substance is then calculated from these data (12-15). Currently, structural determinations by X-ray diffraction are highly computerized, and powder pattern photographs are verv ~" rarelv used. Because manv educational institutions donot have X-ray equipment avaiiable, usually each student is eiven a neeative or nrint of a film and asked to oerform c e h n calcu~atioos. here is a clear pedagogical val"e in the determination o f a cwstal structure hv this method, and the experiment is usualiy included in experimental physical chemistry rourses. Although powder patterns for all alkali halides are available in the literature (16), it is desirahle to be able to eenerate the X-ray powder diffraction pattern of a substancefrom a knowledge bf its density and cubic structure. This increases the variety of "unknowns" available for student usage and allows a comparison of the diffraction patterns of a substance hypothetically crystallizing in a simple (primitive), face-centered, or body-centered cubic lattice. We have develooed a microcom~uteraroeram that simulates X-ray powder diffraction for many substances and oroduces realistic spectra from the input of (1) the atomic or ?ormula weight o f t h e compound, (2) the density of the compound, and (3) the lattice type. The program, written in Microsoft BASIC Version 1.31, for execution on the Sanyo MBC-555 microcomputer, consists of 85 lines, including 10 remark statements, and can be easily converted for use on any other version of BASIC. The program calculates the ~
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