Sensory Aids Research

Contains reports on three research projects.National Institutes of Health (Grant MH-04737-02)National Science Foundation (Grant G-16526)United States Air Force, Electronic Systems Division (Contract AF19(628)-258

Cognitive Information Processing

Contains reports on four research projects.National Institutes of Health (Grant 1 P01 GM-14940-01)National Institutes of Health (Grant 1 PO1 GM-15006-01)Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E

Cognitive Information Processing

Contains reports on two research project.National Institutes of Health (Grant 1 PO1 GM-14940-02)National Institutes of Health (Grant 1 P01 GM-15006-01)Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E

Comparative Direct Analysis of Type Ia Supernova Spectra. IV. Postmaximum

A comparative study of optical spectra of Type Ia supernovae (SNe Ia) obtained near 1 week, 3 weeks, and 3 months after maximum light is presented. Most members of the four groups that were defined on the basis of maximum light spectra in Paper II (core normal, broad line, cool, and shallow silicon) develop highly homogeneous postmaximum spectra, although there are interesting exceptions. Comparisons with SYNOW synthetic spectra show that most of the spectral features can be accounted for in a plausible way. The fits show that 3 months after maximum light, when SN Ia spectra are often said to be in the nebular phase and to consist of forbidden emission lines, the spectra actually remain dominated by resonance scattering features of permitted lines, primarily those of Fe II. Even in SN 1991bg, which is said to have made a very early transition to the nebular phase, there is no need to appeal to forbidden lines at 3 weeks postmaximum, and at 3 months postmaximum the only clear identification of a forbidden line is [Ca II] 7291, 7324. Recent studies of SN Ia rates indicate that most of the SNe Ia that have ever occurred have been "prompt" SNe Ia, produced by young (100,000,000 yr) stellar populations, while most of the SNe Ia that occur at low redshift today are "tardy", produced by an older (several Gyrs) population. We suggest that the shallow silicon SNe Ia tend to be the prompt ones.Comment: Accepted by PAS

Cognitive Information Processing

Contains research objectives and reports on one research project.National Institutes of Health (Grant 1 PO1 GM-14940-01)National Institutes of Health (Grant 1 PO1 GM-15006-01)Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E

Cognitive Information Processing

Contains reports on seven research projects.National Science Foundation (Grant SED76-81985)Graphic Arts Research Foundation (Grant)Providence Gravure, Inc. (Grant)Associated Press (Grant)National Institutes of Health (Grant 1 RO1 GM22547-01)National Institutes of Health (Grant 1 PO1 AG00354-01)Health Sciences Fund (Grant 76-11

Cognitive Information Processing

Contains reports on four research projects.Providence Gravure, Inc. (Grant)International Business Machines Corporation (Grant

Cognitive Information Processing

Contains research objectives, summary of research and reports on four research projects.National Institutes of Health (Grant 5 PO1 GM14940-05)National Institutes of Health (Grant 3 POI1 GM15006-03S2)Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-0300World Health Organization (Grant R/00348)Grant from the Associated Pres

Cognitive Information Processing

Contains research objectives.National Institutes of Health (Grant 5 POI GM14940-06)National Institutes of Health (Grant 1 P01 GM19428-01)National Science Foundation (Grant GK-33736X)Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-0300Grant from the Associated PressPeter Bent Brigham Hospital Purchase Orders F64088Peter Bent Brigham Hospital Purchase Orders F6580

Cognitive Information Processing

Contains reports on four research projects.National Science Foundation (Grant SED76-81985)Associated Press (Grant)Providence Gravure, Inc. (Grant)Taylor Publishing Company (Grant