Digital Commons Network^™

December 28th 1994, Hispanic News

Inland Empire Hispanic News

No abstract provided.

Model And Design-Based Analysis Of Complex Surveys., Joydip Mitra Dr.

Doctoral Theses

We consider estimating the total Y of a variable y defined on a survey population. The survey is complex only in the sense that we admit sample selection with arbitrary probabilities. Our 'analysis' consists in examining efficacies of conf Idence intervals for the For this we need point estimators and or mean square error (MSE) variance { estimators, respectively say, total. the corresponding e and v. The distribution, resulting from repeated sampling, of the pivotal quantity d = (e-Y)/V 1s supposed to approximate that of standard normal deviate t or of Students t with (n-1) degrees of freedom, assuming large …

Orlando Gets Hockey But Not Nhl Hockey, Richard C. Crepeau

On Sport and Society

When the announcement came a little over a week ago The Orlando Sentinel fell over itself like the lapdog it has become for the Orlando Magic and the DeVoss family. It was of course the major news that Orlando was about to get a hockey team in the International Hockey League, and the city was about to facilitate the process with another sweetheart contract with the family DeVoss for use of the O-Arena.

Bias Dependence Of The Depletion Layer Width In Semi-Insulating Gaas By Charge Collection Scanning Microscopy, A. Castaldini, A. Cavallini, C. Del Papa, M. Alietti, C. Canali, F. Nava, C. Lanzieri

Scanning Microscopy

A procedure for the evaluation of the depletion region width of a Schottky barrier diode made on semi-insulating materials has been assessed and applied to gallium arsenide nuclear detectors. This procedure, which makes use of the optical beam induced current method of charge collection scanning microscopy, allows the direct measurement of the depletion layer width. By taking into account the high resistivity of the material under examination and measuring the diode reverse current, it is possible to evaluate the actual voltage applied at the depletion layer boundaries. It was found that, at low actual bias values, the voltage dependence of …

What's Happening: December 28, 1994, Maine Medical Center

What's Happening

No abstract provided.

Principles Of Semiconductor Surface Reconstruction, C. B. Duke

Scanning Microscopy

Semiconductor surfaces are known to reconstruct, i.e., their surface atomic geometries differ from those of the corresponding surface planes in the bulk material. For clean tetrahedrally coordinated semiconductors, these reconstructed geometries are shown to be predicted by five simple principles. These principles are illustrated by the specific examples of Si(100)-(2x1), Si(111)-(2x1), GaAs(100)-c(2x8), GaAs(111)-(2x2), and relaxed zincblende (110) surfaces. The concept of universal (i.e., material independent) semiconductor surface structures is introduced and shown to be characteristic of the cleavage surfaces of tetrahedrally coordinated compound semiconductors. The role of scanning tunneling microscopy in identifying and validating these principles is highlighted.

Letter To Sally Curtis Askew Regarding Award Of A Lucile Elliott Scholarship, December 28, 1994, Mary Smith Forman

Scholarship Committee

A letter from Mary Smith Forman to Sally Curtis AsKew accepting the Lucile Elliott Scholarship awarded to her.

Letter To Sally Curtis Askew Regarding Award Of A Seaall Scholarship, December 28, 1994, Carol Gebel

Scholarship Committee

A letter from Carol Gebel to Sally Curtis AsKew accepting the scholarship awarded to her.

The Murray Ledger And Times, December 27, 1994, Th Murray Ledger And Times

The Murray Ledger & Times

No abstract provided.

Mapping Metal Distributions In Thin Cryosections Without Scanning Transmission Electron Microscope With The Philips Electron Beam And Image Deflection (Ebid) Unit, A. J. Morgan, J. M. Brock, C. Winters, G. H. J. Lewis

Scanning Microscopy

The purpose of the present paper was to describe the use of a commercially-available, and relatively inexpensive, beam and image deflection unit that can facilitate digital X-ray (element) mapping in a standard transmission electron microscope not furnished with a STEM attachment. The test specimen was a thin freeze-dried section of the metal-sequestering chloragogenous tissue from the earthworm, Lumbricus rubellus, inhabiting a soil naturally contaminated with Pb, Zn and Cd. Qualitative maps obtained from this material confirmed the efficacy of the deflection unit, and revealed the presence of three compositionally distinct metal-accumulating compartments within the chloragocytes: (i) ovoid, electron-dense, phosphate-bearing and …

Role Of Surface Interactions In Determining Surface Structure And State Formation In Iii-V Semiconductors, H. E. Ruda, G. P. Jiang

Scanning Microscopy

GaAs(100), (110), and (111) surfaces are chosen as a vehicle to explain the plethora of surface relaxation and reconstruction phenomena seen for III-V compound semiconductors. These relaxation and reconstruction processes directly affect the formation of surface states. The occupation of these states, in turn, can have a profound influence on device performance. The purpose of this work is to attempt to provide a unified description of the phenomena responsible for surface relaxation and reconstruction on these surfaces. Our work makes use of an ab initio effective core potential scheme based on the Hartree Fock approximation. We discuss the critical steps …

Dislocation Nucleation And Propagation In Semiconductor Heterostructures, D. Cherns, S. Mylonas, C. T. Chou, J. Wu, D. E. Ashenford, B. Lunn

Scanning Microscopy

This paper considers misfit dislocation nucleation and propagation in dilute magnetic semiconductor heterostructures in the CdTe-ZnTe-MnTe system. It is shown that, where the deposit is in tension, 1/2 < 110 > dislocations with inclined Burgers vectors propagate by glide along interfacial < 110 > directions and may dissociate giving intrinsic stacking faults. In cases where the deposit is in compression, 1/2 < 110 > dislocations show no evidence of dissociation and propagate by extensive cross-slip to give networks of dislocations close to interfacial < 100 > directions.

Evidence for dislocation sources in ZnTe/GaSb films is presented. ZnTe films contained stacking fault pyramids, single Frank faults and a new type of "diamond defect" …

Surface Stress, Morphological Development, And Dislocation Nucleation During Sixge1-X Epitaxy, D. E. Jesson, S. J. Pennycook, J. -M. Baribeau, D. C. Houghton

Scanning Microscopy

Utilizing Ge marker layer experiments combined with atomic number contrast (Z-contrast) imaging, we have studied the evolving surface morphology of Si_xGe_1-x alloys during growth by molecular beam epitaxy. The marker layers map out the instability transition between planar two-dimensional (2D) growth and three-dimensional (3D) growth. The transition occurs via the gradual formation of a surface ripple as anticipated from instability theory. However, these undulations rapidly develop into crack-like surface instabilities which we simulate and explain by the mechanism of stress-driven surface diffusion. Finally, we model the large stresses associated with these features within a fracture mechanics formalism. …

12/27/1994 - Eiu Highlights Of 1994, University Marketing And Communications

1994

No abstract provided.

Mother Of Perpetual Help Church Of The Deaf, December 25, 1994

Mother of Perpetual Health Church of the Deaf

A newsletter published for Deaf Catholics in Omaha, NE

Blessed Kateri Catholic Center Newsletter, Christmas 1994

Blessed Kateri Catholic Center Newsletter

A newsletter published for Deaf Catholics in Toledo, OH

Good News, Christmas 1994

Good News

A newsletter published for Deaf Catholics in Croydon, PA

Vision, Christmas 1994

Vision

A newsletter published for Deaf Catholics in USA

VisionFinding Aid

Light Scattering And Electron Microscopy Study Of The Surface Morphology Of Gaas Films Grown By Molecular Beam Epitaxy, M. K. Nissen, C. Lavoie, S. Eisebitt, T. Pinnington, T. Tiedje

Scanning Microscopy

The surface morphology of thermally quenched GaAs films grown by molecular beam epitaxy on GaAs substrates has been studied by elastic light scattering, by scanning electron microscopy and by scanning tunneling microscopy (STM) in air. STM shows that the oxide-desorbed surface of GaAs is pitted, but smooths after deposition of a few hundred nanometers of material. Light scattering shows that, after the surface has smoothed, the power spectral density of the surface approaches a q^-2 dependence on spatial frequency over the spatial frequency range 0.2 μm^-1 < q < 20 μm^-1 that is accessible to the light scattering measurements at 488 nm. …

Uis Commission On Volcanic Caves Newsletter, No. 5, December 25, 1994, International Union Of Speleology

Union Internationale de Spéléologie (UIS) Commission on Volcanic Caves

No abstract provided.

Uis Commission On Volcanic Caves Newsletter, No. 5, December 25, 1994, International Union Of Speleology

Union Internationale de Spéléologie (UIS) Commission on Volcanic Caves

No abstract provided.

F.Y.I., 1994-12-23, Office Of Public Affairs

F.Y.I.

Newsletter published by Governors State University between 1989-1996.

The Morphology And Misfit Dislocation Formation Characteristics Of Strained Heteroepitaxial Layers: Ex Situ And In Situ Growth Studies, A. G. Cullis

Scanning Microscopy

Under certain regimes of heteroepitaxial layer growth, misfit stresses can lead to very significant distortions in interface morphology, which can influence strain relief and subsequent misfit dislocation introduction. These phenomena have been clearly demonstrated in the case of SiGe/Si heteroepitaxy and the way in which surface SiGe growth ripples are accompanied by strain waves has been established. The ripples provide partial elastic relief of the layer misfit stress in a manner which has been correlated with theoretical expectations. The local stress variations ultimately may influence the formation and disposition of misfit dislocations in the strained layer structures. The present paper …

Ionoluminescence: A New Tool For Nuclear Microprobes In Geology, C. Yang, N. P. -O. Homman, K. G. Malmqvist, L. Johansson, N. M. Halden, V. Barbin

Scanning Microscopy

When an ion beam in the energy range of a few MeV/amu impacts on a mineral, visible light can often be observed. This light, induced by energetic ions, is termed ionoluminescence (IL). The intensity and wavelength of the ionoluminescent light provide information concerning the nature of luminescence centers, such as trace substituents and structural defects, found in the mineral. This makes IL a useful complement to other methods of ion beam analysis (IBA), such as particle induced X-ray emission (PIXE) and Rutherford backscattering (RBS), in characterizing geological samples. In the present study, a proton or alpha particle beam was used …

Ultrastructure Of Dentin Matrix In Heritable Dentin Defects, J. Waltimo, H. Ranta, P. -L. Lukinmaa

Scanning Microscopy

Heritable dentin defects form a group of diseases which exclusively affect dentin among the various dental tissues. While one type is associated with the generalized connective tissue disorder, osteogenesis imperfecta, other types occur as single traits. The clinical manifestations of the dentin defects vary from insignificant to severe enough to cause aesthetical and functional failure of the teeth. Scanning and transmission electron microscopic studies, reviewed in this paper, have markedly clarified the ultrastructure of the aberrant dentin matrix. Both similar and different changes seem to occur in the various forms of heritable dentin defects. Abnormalities in the appearance and organization …

We Forum, Vol Xviii No. 35 - Dec. 23-29, 1994, Jose Burgos, Jr.

We Forum

No abstract provided.

Observations On Interactions Between Metal Clusters And Iii-V Semiconductor Substrates, Theodore D. Lowes

Scanning Microscopy

Interfacial reactions between deposited indium and gallium metals with GaAs(001) substrates are discussed. After Knudsen cell molecular beam epitaxy (MBE) deposition, samples were annealed in ultrahigh vacuum (UHV) and examined by ex situ electron microscopy. The resulting microstructure was compared to the microstructure of GaAs(001) substrates without metal deposition. It is shown that significant interactions occur between the deposited metal and substrate and that the final microstructure is consistent with the model for thermal decomposition of III-V compound semiconductor substrates.

Metastable Reconstructions On Si(111), Y. -N. Yang, E. D. Williams

Scanning Microscopy

We report unambiguous atomic scale evidence demonstrating that the atom density in the high temperature "1x1" phase of Si(111) is ~6% higher than the 7x7. Such evidence is provided by scanning tunneling microscopy (STM) observation of excess adatom density, and related island formation, on surfaces with very large terraces. The unusually large terraces were produced by heating the sample with DC current in the step-down direction at 1200°C. By trapping adatoms on the terraces through a quench, we have also created areas of metastable reconstructions, i.e., 9x9, 2x2, c2x4 and √3x√3, much larger than previously reported. For …

Boron Reconstructed Si(111) Surfaces Produced By B2o3 Decomposition, J. Nogami, S. Yoshikawa, J. C. Glueckstein, P. Pianetta

Scanning Microscopy

Scanning tunneling microscopy has been used to study the growth of boron on the Si(111) surface. Boron was deposited in the form of B₂O₃ which was decomposed by heating the substrate. With this technique, it is possible to control the B coverage, and also to produce the well known √3 x √3 reconstruction at annealing temperatures as low as 600°C. The optimal conditions for the formation of the √3 x √3 surface by B₂O₃ decomposition are given. In addition, the nature of the √3 x √3 surface over …

Montana Committee For The Humanities Elects New Board Members, University Of Montana--Missoula. Office Of University Relations

University of Montana News Releases, 1928, 1956-present

No abstract provided.