Letter, 1976 September 5, from Edith Borroff to Eva Jessye

2 pages, Borroff is a proffessor and an old friend of Jessye

Letter, n.d. , from Edith Borroff to Eva Jessye

2 pages, Borroff is a proffessor and an old friend of Jessye

Raman scattering by optical phonons in In1−y−zAlyGazAs lattice matched to InP

We report on Raman scattering by longitudinal optical phonons in In1−y−zAlyGazAs (1−y−z=0.53) lattice matched to InP. The quaternary alloys were grown on (001) InP by molecular beam epitaxy. The phonon spectra exhibit three‐mode behavior. The frequencies of AlAs‐ and GaAs‐like modes vary linearly with the concentration of Al (or Ga) while the position of the InAs‐like phonon remains nearly constant. The data show no evidence of alloy clustering.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71267/2/APPLAB-53-17-1652-1.pd

Electronic raman scattering in quantum wells: Coupled levels in tilted magnetic fields

We report on a magneto-Raman scattering investigation of free and donor-bound electrons in GaAs---AlxGa1-xAs quantum wells. For fields perpendicular to the layers, the spectra show intersubband transitions of photoexcited electrons and 1s --> 1s' donor excitations. Tilted fields lead to subband-Landau level and 1s' - 2p+ coupling. Experimental results for the latter case agree very well with variational calculations. Data on combined intersubband-cyclotron resonances at arbitrary tilt angles are accurately described by expression valid for wells. The parabolic approach is shown to provide a good approximation in situations where coupling to higher subbands can be neglected.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26968/1/0000535.pd

Observation of coupled quasi-two-dimensional electronic excitations in tilted magnetic fields

We report on a magneto-Raman scattering investigation of free and donor-bound electrons in GaAs/AlxGa1-xAs quantum wells. For fields perpendicular to the layers, the spectra show intersubband transitions of photoexcited electrons and ls-->ls' donor excitations. Tilted fields lead to subband-Landau level and ls'-2p+ coupling. Experimental results for the latter case agree very well with variational calculations. Data on combined intersubband-cyclotron resonances at arbitrary tilt angles are accurately described by expressions valid for parabolic wells. The parabolic approach is shown to provide a good approximation in situations where coupling to higher subbands can be neglected.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27584/1/0000628.pd

Raman scattering in a two-dimensional electron gas: Boltzmann equation approach

The inelastic light scattering in a 2-d electron gas is studied theoretically using the Boltzmann equation techniques. Electron-hole excitations produce the Raman spectrum essentially different from the one predicted for the 3-d case. In the clean limit it has the form of a strong non-symmetric resonance due to the square root singularity at the electron-hole frequency $\omega = vk$ while in the opposite dirty limit the usual Lorentzian shape of the cross section is reestablished. The effects of electromagnetic field are considered self-consistently and the contribution from collective plasmon modes is found. It is shown that unlike 3-d metals where plasmon excitations are unobservable (because of very large required transfered frequencies), the two-dimensional electron system gives rise to a low-frequency ($\omega \propto k^{1/2}$) plasmon peak. A measurement of the width of this peak can provide data on the magnitude of the electron scattering rate.Comment: 4 pages, 3 figures. to appear in Phys. Rev. B 59 (1999

Revision rates after primary hip and knee replacement in England between 2003 and 2006

<b>Background</b>: Hip and knee replacement are some of the most frequently performed surgical procedures in the world. Resurfacing of the hip and unicondylar knee replacement are increasingly being used. There is relatively little evidence on their performance. To study performance of joint replacement in England, we investigated revision rates in the first 3 y after hip or knee replacement according to prosthesis type. <b>Methods and Findings</b>: We linked records of the National Joint Registry for England and Wales and the Hospital Episode Statistics for patients with a primary hip or knee replacement in the National Health Service in England between April 2003 and September 2006. Hospital Episode Statistics records of succeeding admissions were used to identify revisions for any reason. 76,576 patients with a primary hip replacement and 80,697 with a primary knee replacement were included (51% of all primary hip and knee replacements done in the English National Health Service). In hip patients, 3-y revision rates were 0.9% (95% confidence interval [CI] 0.8%–1.1%) with cemented, 2.0% (1.7%–2.3%) with cementless, 1.5% (1.1%–2.0% CI) with “hybrid” prostheses, and 2.6% (2.1%–3.1%) with hip resurfacing (p < 0.0001). Revision rates after hip resurfacing were increased especially in women. In knee patients, 3-y revision rates were 1.4% (1.2%–1.5% CI) with cemented, 1.5% (1.1%–2.1% CI) with cementless, and 2.8% (1.8%–4.5% CI) with unicondylar prostheses (p < 0.0001). Revision rates after knee replacement strongly decreased with age. <b>Interpretation</b>: Overall, about one in 75 patients needed a revision of their prosthesis within 3 y. On the basis of our data, consideration should be given to using hip resurfacing only in male patients and unicondylar knee replacement only in elderly patients

The Instrumental Works Of Jean-joseph Cassanea De Mondonville (volumes I And Ii).

PhDMusicUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/179395/2/5902099.pd

Sir Gawain and the Green Knight

xiii, 62 ha

wallace Stevens:A Collection of Gritical Essays

181 hal;ill;23 c