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Recombination lifetimes in gamma-irradiated silicon
No full textThe small-signal recombination lifetimes of minority carriers were
measured as a function of temperature in silicon before and after irradiation
at room temperature by cobalt 60 gamma rays. The resistivity of
the boron doped samples ranged between 10 and 5000 ohm-cm, and the
resistivity of the phosphorus doped samples was between 20 and 220 ohm-cm.
Both crucible and floating zone grown materials were investigated.
The radiation induced lifetime changes were interpreted by the theory
of Hall, and Shockley and Read. The lifetime changes in n-type material
were interpreted to be due to two energy levels, one 0.17 ev from the
conduction band edge, which was assumed to be the substitutional oxygen
(A center) defect, and the other at 0.4 ev from the conduction band edge.
On the basis of annealing data, it appeared that the 0.4 ev level could be
due to several defects whose energy levels coincided, but that most of the
recombination in the float~zoned material occurred through the donor-vacancy
complex (E center). The introduction rates of the levels were not strongly
influenced by differences in resistivity, but the introduction rate of the
0.4 ev level was much less in material containing large oxygen concentrations.
Defects controlling the lifetime in irradiated p-type material were
placed at 0.18 ev above the valence band edge and at 0.3 ev below the
conduction band edge. The former level could possibly be located 0.18 ev
below the conduction band edge, but it is most unlikely that it is the A center
because of the ratio of the hole and electron Qapture cross-sections. The
0.18 ev level controlled the lifetime in the room temperature region in the
pulled material, and the 0.3 ev level controlled the lifetime at all measured
temperatures in float-zoned material whose resistivity was 70 ohm-em or
greater. The ratio of the hole to electron capture cross-section for the
0.3 ev level was about 20. No strong effect of resistivity was seen in
either of the p-type silicon, but the effect of the larger oxygen content
of the pulled material was to reduce the introduction rate of the 0.3 ev
level.Submitted by Carolyn Mead ([email protected]) on 2011-05-27T16:08:14Z
No. of bitstreams: 1
1966_hewes.pdf: 4384284 bytes, checksum: c3eae77e5756d6f5f378e16955f7e257 (MD5)Made available in DSpace on 2011-05-27T16:08:14Z (GMT). No. of bitstreams: 1
1966_hewes.pdf: 4384284 bytes, checksum: c3eae77e5756d6f5f378e16955f7e257 (MD5)
Previous issue date: 1966Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead ([email protected]) on 2011-05-27T16:08:14Z
Item is restricted indefinitely.Restriction data tranferred 2014-07-01T11:13:45-05:00
Original Data
Group with Access UIUC Users [automated]
Release Date: none
Reason: ThesisThesisU of I Onl
The Illinois Coal Mining Industry
No full textMade available in DSpace on 2014-12-05T21:03:49Z (GMT). No. of bitstreams: 1
0002728.pdf: 14671678 bytes, checksum: d17f161412f65d9b46ba5ca4eca2d0aa (MD5)
Previous issue date: 1951Embargo set by: Seth Robbins for item 58506
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only290 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1951
On Program Restructuring, Scheduling, and Communication for Parallel Processor Systems
No full textThis dissertation discusses several software and hardware aspects of program execution on large-scale, high-performance parallel processor systems. The issues covered are program restructuring, partitioning, scheduling and interprocessor communication, classification and utilization of program parallelism, and synchronization and hardware design issues of specialized units. All this work was performed focusing on a single goal: maximizing program speedup, or equivalently, minimizing parallel execution time. Parafrase, a Fortran restructuring compiler was used to transform programs in a parallel form and conduct experiments. Two new restructuring techniques are presented, loop coalescing and subscript blocking. Compile-time and run-time scheduling schemes are covered extensively. Depending on the program construct, these algorithms generate optimal or near-optimal schedules. Techniques for program partitioning and minimization of interprocessor communication for idealized program models and for real Fortran programs are also discussed. The close relationship between scheduling, interprocessor communication, and synchronization becomes apparent at several points in this work. Finally, the impact of various types of overhead on program speedup and experimental results are presented.Made available in DSpace on 2014-12-15T19:25:49Z (GMT). No. of bitstreams: 1
8701592.pdf: 7770759 bytes, checksum: 3b9de78507d5a6053b78e5a0d7e85284 (MD5)
Previous issue date: 1986Embargo set by: Seth Robbins for item 69729
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only220 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1986
Functional Approaches and Communicative Competence: English Language Teaching in Non-Native Contexts
No full textRecently considerable attention has been given to communicative approaches to language teaching, which have grown from the realization that knowledge of grammatical forms and structures alone does not adequately prepare learners to use the language they are learning effectively when communicating with others. It is also an outgrowth of renewed interest in the view of language as communication, a view associated with functional approaches to linguistics, which have been acknowledged as the theoretical base of the development of communicative language teaching theory and practice. However, the relationship between communicative language teaching and functional approaches to linguistics is far from clear.This study explores the relationship of functional approaches and communicative language teaching through a consideration of the Prague and British linguistic traditions, concepts such as communicative competence, intelligibility, and model, the nature of English language use and teaching in the contexts of India, Japan, and West Germany, and the application of American and European communicative approaches to the development of English language teaching materials designed for English language learners in these three non-native contexts.As an applied study, it does not claim to offer solutions to pedagogic problems, but to provide a means by which such problems may be solved. One of its objectives is to show how a theoretical model for linguistics can be used for classroom purposes by relating a linguistic framework to actual classroom materials and activities. It also offers a clarification of linguistic principles, drawn from the functional linguistic models of the Prague School and the British linguistic tradition, which can guide in the development and implementation of communicative language teaching models which are responsive to the needs of a growing number of learners of English in non-native contexts.This study also addresses applied and theoretical implications for teacher training, cross-cultural communication, models in the pedagogical context, intelligibility in the classroom, and syllabus design.Made available in DSpace on 2014-12-15T20:08:30Z (GMT). No. of bitstreams: 1
8521720.pdf: 13193228 bytes, checksum: 7b18c8110b31e9f9879d1348a83e1d19 (MD5)
Previous issue date: 1985Embargo set by: Seth Robbins for item 69992
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only159 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985
Partitioning of Areas Into Subareas: The Problem and a Comparison of Twoprocedures
No full textMade available in DSpace on 2014-12-09T20:15:02Z (GMT). No. of bitstreams: 1
6408355.pdf: 3778308 bytes, checksum: 7964da1a37c765a0096e2db1a7cc23c4 (MD5)
Previous issue date: 1964Embargo set by: Seth Robbins for item 61483
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only91 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1964
Linear Control Laws for Singular Linear Systems
No full textMade available in DSpace on 2014-12-08T22:23:30Z (GMT). No. of bitstreams: 1
6408438.pdf: 722029 bytes, checksum: e7b5b8e6e863a4d1d6fce4411ca872f0 (MD5)
Previous issue date: 1964Embargo set by: Seth Robbins for item 59749
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only39 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1964
An Evaluation of the Student-Teaching Experience in Athletic Coaching Formale Undergraduate Physical Education Majors in Illinois
No full textMade available in DSpace on 2014-12-12T01:11:58Z (GMT). No. of bitstreams: 1
7114869.pdf: 6511203 bytes, checksum: 3145701eec3750cf8a0d3962288fd504 (MD5)
Previous issue date: 1970Embargo set by: Seth Robbins for item 65575
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only251 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1970
Effects of Low Concentrations of Chloramphenicol on Bacterial Metabolism
No full textMade available in DSpace on 2014-12-10T23:24:33Z (GMT). No. of bitstreams: 1
7414534.pdf: 7814477 bytes, checksum: 7a9297e97512cdcfc242e904002670ad (MD5)
Previous issue date: 1974Embargo set by: Seth Robbins for item 64364
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only245 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1974
An Analysis of Transportation Nodes Using Several Transportation Terminalvariables
No full textMade available in DSpace on 2014-12-10T23:41:30Z (GMT). No. of bitstreams: 1
7309962.pdf: 2624057 bytes, checksum: 186d3b68c1778ec86eefcabfa011e70c (MD5)
Previous issue date: 1972Embargo set by: Seth Robbins for item 64431
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only92 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1972
High School Dropping- Out and Returning: Case Studies and Policy Recommendations
No full textMajor conclusions of this study were that the majority of the participants did not connect the importance of high school education to their future lives when they were attending high school because they felt the school curriculum was not relevant to their interests or needs. Besides, most of the participants felt they were not cared for by their teachers in the periods of their dropping out. They experienced that it was easy to cut class and enjoy excitement outside of school and there was no other option than leaving school when they found out that they could not graduate on time. The results of this study suggest that real strides can be made in reducing the number of dropouts, and they correspond to the efforts of school systems providing a relevant curriculum, a caring system, and establishing an effective and long-term intervention plan.Made available in DSpace on 2015-09-25T19:55:05Z (GMT). No. of bitstreams: 2
license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5)
3337687.pdf: 2814183 bytes, checksum: 983ecfc33ae28be2bc2c211175fe75ee (MD5)
Previous issue date: 2008Embargo set by: Seth Robbins for item 81329
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only224 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008