Codes and Supersymmetry in One Dimension

Adinkras are diagrams that describe many useful supermultiplets in D=1 dimensions. We show that the topology of the Adinkra is uniquely determined by a doubly even code. Conversely, every doubly even code produces a possible topology of an Adinkra. A computation of doubly even codes results in an enumeration of these Adinkra topologies up to N=28, and for minimal supermultiplets, up to N=32.Comment: 48 pages, a new version that combines arXiv:0811.3410 and parts of arXiv:0806.0050, for submission for publicatio

Nuclear magnetic resonance-paramagnetic relaxation enhancements: Influence of spatial quantization of the electron spin when the zero-field splitting energy is larger than the Zeeman energy

Dissolved paramagnetic ions generally provide an efficient mechanism for the relaxation of nuclear spins in solution, a phenomenon called the nuclear magnetic resonance-paramagnetic relaxation enhancement (NMR-PRE). Metal ions with electron spins S ≥ 1S⩾1 exhibit rich NMR relaxation phenomena originating in the properties of the zero-field splitting (zfs) interaction, which vanishes for spin-½12 ions but which is nonzero for S ≥ 1S⩾1 ions in site symmetry lower than cubic. For S ≥ 1S⩾1 ions in the vicinity of the zfs-limit, i.e., at magnetic-field strengths low enough that the zfs energy exceeds the Zeeman energy, the NMR-PRE depends strongly on the detailed structure of the electron spin energy levels as well as on the spatial quantization of the spin motion. It is shown theoretically and experimentally that the NMR-PRE produced by integer spins can be influenced strongly by the small intradoublet zero-field splittings, i.e., the splittings between the components of the non-Kramers doublets, which are produced by noncylindrical components of the crystal field potential. These small splittings produce relatively low-frequency oscillations in the dipolar field associated with 〈〉〈Sẑ〉 (the spin component along the molecule-fixed ẑ axis). These motions decouple the nuclear spin from the electron spin, thereby depressing, in some cases very strongly, the NMR-PRE. The presence of a relatively small Zeeman field, comparable in magnitude to the intradoublet spacing but small compared to the larger interdoublet zfs splittings, causes a major change in the spin wave functions which has profound effects on the motions of the electron spin. When the Zeeman energy exceeds the small zfs splitting, the oscillatory motion of 〈〉〈Sẑ〉 damps out, with the result that the electron spin couples more effectively to the nuclear spin, providing a more efficient NMR relaxation pathway. NMR-PRE data are presented for the S = 1S=1 complex Ni(II)(o-pda)2Cl2Ni(II)(o-pda)2Cl2 (o-pda = ortho-phenylenediamine)(o-pda=ortho-phenylenediamine) which confirm the importance of the splitting of the mS = ±1mS=±1 non-Kramers doublet on the NMR relaxation efficiency. The zfs E-parameter was measured from the NMR data to be ∣E∣ = 0.26 cm−1.∣E∣=0.26cm−1. The S = 2S=2 spin system, Mn(III)Mn(III)-tetraphenylporphyrin sulfonate, exhibits a related phenomenon which arises from the effects of a small zfs splitting, Δϵ±2,Δϵ±2, of the mS = ±2mS=±2 non-Kramers doublet that is caused by a fourfold rotational component of the crystal field potential. The splitting Δϵ±2Δϵ±2 was measured from NMR data to be 0.20 cm−1.0.20cm−1. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70721/2/JCPSA6-109-10-4035-1.pd

Brayton-cycle radioisotope heat source design study. Phase I - /Conceptual design/ report

Conceptual designs for radioisotope heat source systems to provide 25 kW thermal power to Brayton cycle power conversion system for space application

Transistors

Contains reports on six research projects

Ariel - Volume 4 Number 6

Editors David A. Jacoby Eugenia Miller Tom Williams Associate Editors Paul Bialas Terry Burt Michael Leo Gail Tenikat Editor Emeritus and Business Manager Richard J. Bonnano Movie Editor Robert Breckenridge Staff Richard Blutstein Mary F. Buechler J.D. Kanofsky Rocket Weber David Maye

The effects of exposure to a rotating environment /10 rpm/ on four aviators for a period of twelve days

Motion sickness studies of aviators exposed to rotating environment - Aerospace medicin

Delayed-onset endophthalmitis associated with corneal suture infections

BACKGROUND: The purpose of the current study was to report the microbiology, risk factors, and treatment outcomes in patients with delayed-onset endophthalmitis associated with corneal suture infections. For this retrospective consecutive case series, a search of the ocular microbiology department database was performed to identify all patients with positive corneal and intraocular cultures (anterior chamber and/or vitreous) between 01 January 1995 and 01 January 2010. A subset of patients with a history of corneal suture infections and delayed-onset endophthalmitis was identified. RESULTS: Over the 15-year period of the study, 68 patients were identified to have both positive corneal and intraocular cultures. Among them, six patients were identified to have a culture-proven, delayed-onset endophthalmitis that developed from a culture-positive corneal suture infection. All of the patients in the current study were using topical corticosteroids at the time of diagnosis. In four of six patients, there was documented manipulation of a suture before the development of endophthalmitis. Streptoccocus was identified as the causative organism in five of six patients in the current study. All of the Streptoccocus isolates were sensitive to vancomycin. The single case of Serratia marcescens endophthalmitis was sensitive to amikacin, ceftazidime, ciprofloxacin, gentamicin, and tobramycin. Treatment modalities varied and were guided by the attending ophthalmologist depending upon clinical presentation. One patient with severe Streptococcus pyogenes keratitis and endophthalmitis underwent a primary enucleation after developing a wound dehiscence. Of the remaining five patients, all received topical and intravitreal antibiotics. Therapeutic penetrating keratoplasty was performed in three patients. Pars plana vitrectomy was performed in two patients. Visual acuity outcomes ranged from 20/150 to no light perception. CONCLUSIONS: In the current study, Streptococcus was isolated in nearly all patients with delayed-onset endophthalmitis associated with corneal suture infections. Topical steroid use and suture manipulation were identified as associated factors for developing endophthalmitis. Visual acuity outcomes were poor despite the prompt recognition of endophthalmitis and appropriate antibiotic therapy