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Classical Description And Calculation Of Ionization In Collisions Of 100 Ev Electrons And Positrons With He And H2, D. R. Schultz, L. Meng, Ronald E. Olson Nov 1992

Classical Description And Calculation Of Ionization In Collisions Of 100 Ev Electrons And Positrons With He And H2, D. R. Schultz, L. Meng, Ronald E. Olson

Physics Faculty Research & Creative Works

In order to explore the range of applicability of the classical trajectory Monte Carlo technique concerning the phenomena associated with light-particle impact of atoms and molecules we present calculations of the singly and doubly differential cross sections for 100 eV electron and positron impact of He and H2 Through comparison with experimental measurements it is noted in what regimes of ejection energy and angle the classical model describes reasonably the process of ionization by electrons. We find that reasonable agreement is obtained regarding the integrated (singly differential and total) cross sections while the features of the doubly differential cross …

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The Missouri Miner, November 11, 1992 Nov 1992

The Missouri Miner, November 11, 1992

The Missouri Miner Newspaper

No abstract provided.

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Electrochemical Evaluation Of The Adherence Of Zinc To Aluminum Cathodes, Jang Sop Han, Thomas J. O'Keefe Nov 1992

Electrochemical Evaluation Of The Adherence Of Zinc To Aluminum Cathodes, Jang Sop Han, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

Excess fluoride ions in zinc electrolyte are known to cause problems with the removal of electrowon zinc from aluminum blanks. The mechanisms responsible for this undesirable adherence were studied. Acid zinc sulfate electrolyte similar to that employed in zinc electrowinning was used. Using electrolyte containing various fluoride ion concentrations, the initial nucleation and growth morphology of zinc and the aluminum electrode surface were examined using scanning electron microscopy. Electrochemical tests were also carried out in various solutions to obtain a better understanding of the polarization behavior of the system. © 1992.

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The Missouri Miner, November 04, 1992 Nov 1992

The Missouri Miner, November 04, 1992

The Missouri Miner Newspaper

No abstract provided.

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Structural Ceramic Incorporating Boron Carbide Whiskers For The Strengthening Thereof, P. D. Ownby, J. Liu Nov 1992

Structural Ceramic Incorporating Boron Carbide Whiskers For The Strengthening Thereof, P. D. Ownby, J. Liu

Materials Science and Engineering Faculty Research & Creative Works

Ceramic composites, and in particular structural ceramic composites, have enhanced strength, toughness and abrasion resistance due to the presence of up to about 40 volume percent of relatively large boron carbide whiskers. Although whiskers of various sizes were studied, those of particular interest are whiskers having an average diameter greater than about 3 micrometers, and particularly about 5 to about 8 micrometers, with an average aspect ratio of about 50. Due to the larger size, which had been predicted to be detrimental, there is less respiratory health risk when using these whiskers in the manufacturing of thse improved ceramic composites. …

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Missouri S&T Magazine, November 1992, Miner Alumni Association Nov 1992

Missouri S&T Magazine, November 1992, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

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A Mössbauer Effect Study Of The Microscopic Magnetic Properties Of Nd₂Fe₁₇ And Nd₂Fe₁₇N₂.₆, Gary J. Long, Oran Allan Pringle, Fernande Grandjean, K. H. J. Buschow Nov 1992

A Mössbauer Effect Study Of The Microscopic Magnetic Properties Of Nd₂Fe₁₇ And Nd₂Fe₁₇N₂.₆, Gary J. Long, Oran Allan Pringle, Fernande Grandjean, K. H. J. Buschow

Chemistry Faculty Research & Creative Works

The Mössbauer spectra of Nd2Fe17 and Nd 2Fe17N2.6 have been measured at various temperatures between 78 and 295 K and analyzed with a model that is based on the Wigner-Seitz cell environment of each iron site, the orientation of the magnetization, and the magnetic moments as determined from either neutron-diffraction measurements or band-structure calculations. Upon nitrogenation of Nd2Fe17, the weighted average isomer shift increases from 0.060 to 0.164 mm/s and further the isomer shifts of the four crystallographically distinct sites increase in agreement with the increase observed in their …

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Investigation Of Strontium-Doped La(Cr, Mn)O3 For Solid Oxide Fuel Cells, Rasit Koc, Harlan U. Anderson Nov 1992

Investigation Of Strontium-Doped La(Cr, Mn)O3 For Solid Oxide Fuel Cells, Rasit Koc, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The (La, Sr) (Cr, Mn)O3 system was investigated in an effort to develop an interconnect and cathode materials for solid oxide fuel cells. Sintering studies were done in air at temperatures below 1500°C. Significant improvements in densification were observed with substitution of 50 mol% Mn for chromium and a density of 95% theoretical was achieved with the substitution of 70 mol% Mn for chromium in the La(Cr, Mn)O3 system. Electrical conductivity (d.c.) measurements were made as a function of temperature and oxygen activity. At 1000°C and 1 atm oxygen, the electrical conductivity ranged from 2.2-20 S cm-1 …

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Photoluminescence And Raman Studies Of Cds Films Grown By Metal-Organic Chemical Vapor Deposition On Si{111} Substrates, Alok K. Berry, P. M. Amirtharaj, Jing Tong Du, Jack L. Boone, Don D. Martin Oct 1992

Photoluminescence And Raman Studies Of Cds Films Grown By Metal-Organic Chemical Vapor Deposition On Si{111} Substrates, Alok K. Berry, P. M. Amirtharaj, Jing Tong Du, Jack L. Boone, Don D. Martin

Electrical and Computer Engineering Faculty Research & Creative Works

CdS epitaxial films grown using metal-organic chemical vapor deposition on Si{111} substrates at growth temperatures ranging from 270 to 325 °C have been characterized using photoluminescence and Raman spectroscopy. Out of all the samples the best optical behavior is obtained from that grown at the lowest temperature. Samples grown at the lowest temperature exhibited increased intensity of the bound excitonic peaks and reduced emission at the defect-related luminescence region. The Raman spectra were compatible with the film surface being normal to the c axis, indicating a preferred growth orientation. © 1992.

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The Missouri Miner, October 28, 1992 Oct 1992

The Missouri Miner, October 28, 1992

The Missouri Miner Newspaper

No abstract provided.

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Line Emission From C⁶⁺, O8+ + Li Electron Capture Collisions, Ronald E. Olson, J. Pascale, R. Hoekstra Oct 1992

Line Emission From C⁶⁺, O8+ + Li Electron Capture Collisions, Ronald E. Olson, J. Pascale, R. Hoekstra

Physics Faculty Research & Creative Works

Electron capture cross sections to nl sublevels have been calculated for 1-10keVu−1 collisions of C6+ and O8+ projectiles on a Li target. The classical trajectory Monte Carlo method has been employed with the initial phase distributions for the Li(2s) target obtained from Hartree-Fock calculations. The cross sections are found to maximize at π = 7 for C6+ and n = 8−9 for O8+. The nl cross sections were used to calculate Δ n = 1 line emission cross sections. Comparison of these cross sections with the experimental results of Wolfruni et al indïoitçs good …

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Using Minimal And Maximal Fault Tolerance For The Assessment Of Fault-Tolerant Algorithms, Martina Schollmeyer, Bruce M. Mcmillin Oct 1992

Using Minimal And Maximal Fault Tolerance For The Assessment Of Fault-Tolerant Algorithms, Martina Schollmeyer, Bruce M. Mcmillin

Computer Science Technical Reports

No abstract provided.

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The Missouri Miner, October 21, 1992 Oct 1992

The Missouri Miner, October 21, 1992

The Missouri Miner Newspaper

No abstract provided.

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Tests Of Profiled Steel Decks With V-Stiffeners, E. S. Bernard, Russell Q. Bridge, Gregory J. Hancock Oct 1992

Tests Of Profiled Steel Decks With V-Stiffeners, E. S. Bernard, Russell Q. Bridge, Gregory J. Hancock

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The size and position of intermediate stiffeners in the compression flanges of thin-walled profiled steel decks exerts a strong influence on the dominant buckling mode of the flange. The ability of the deck to provide both high load carrying capacity before the onset of elastic buckling and a high ultimate load capacity may therefore be affected. A programme of tests to determine the effectiveness of intermediate stiffeners in controlling buckling modes has been undertaken. A series of specimens were loaded in pure bending resulting in various buckling waveforms prior to ultimate failure through a plastic collapse mechanism. All specimens were …

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Flexural Capacity Of Discretely Braced C'S And Z'S, Thomas Sputo, Jack Haynes, Duane S. Ellifritt Oct 1992

Flexural Capacity Of Discretely Braced C'S And Z'S, Thomas Sputo, Jack Haynes, Duane S. Ellifritt

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The American Iron and Steel Institute's Specification for the Design of Cold-Formed Steel Structural Members (1) presently requires that channel and zee flexural members, when not attached to sheathing, be braced against twist and lateral translation at the quarter-points of the span (Section D3.2.2). This provision first appeared in the Second Edition of the Specification in 1956, and has been there through all succeeding editions up through the 1989 Addendum. The newest formula for lateral buckling (part (a) of C3.1.2) is a more exact procedure for calculating lateral torsional buckling of a doubly, singly, or point symmetrical section than was …

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Tests Of Continuous Purlins Under Downwards Loading, Michael Celeban, Chris Healy, Gregory J. Hancock Oct 1992

Tests Of Continuous Purlins Under Downwards Loading, Michael Celeban, Chris Healy, Gregory J. Hancock

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The paper describes a test program on purlin-sheeting systems for which the sheeting was screw fastened to the purlins. The test program simulates downwards loading. Z-section purlins were tested in three span continuous lapped configurations. The test purlins were supported by a range of bridging (bracing) members ranging from no bracing to one brace per span. The test results are compared with the design values computed using the Australian Cold-Formed Steel Structures Standard (AS1538-1988). The Australian Standard design is based on a flexural-torsional buckling analysis which may include the restraint from attached sheeting.

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The Buckling Behaviour Of Hollow Flange Beams, Mahen Mahendran, T. J. Heidt Oct 1992

The Buckling Behaviour Of Hollow Flange Beams, Mahen Mahendran, T. J. Heidt

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A new cold formed structural section known as the hollow flange beam is currently under development in Australia. This section will have many applications, particularly in portal frame buildings. This paper discusses the lateral distortional buckling behaviour of the hollow flange beam.

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Recent Research And Developments In Cold-Formed Steel Design And Construction, Wei-Wen Yu, Roger A. Laboube Oct 1992

Recent Research And Developments In Cold-Formed Steel Design And Construction, Wei-Wen Yu, Roger A. Laboube

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Unstiffened Elements - Some Interesting Features - Tests of Profiled Steel Decks with V-Stiffeners - Bending Strength of Beams with Non-Linear Analysis - Local and Distortional Buckling of Thin-Walled Beams - Design of C-Sections Against Deformational Lip Buckling - Lateral Buckling of Singly Symmetric Beams - Flexural Capacity of Discretely Braced C's and Z's - The Buckling Behaviour of Hollow Flange Beams - Experimental Investigations of I-Beams - Tests of Continuous Purlins Under Downwards Loading - Tests of Full-Scale Roofing Systems - Profiled Sheet Behaviour Under Concentrated Load - On Design of Profiled Sheets with Varying Cross Sections - Properties …

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Stainless Steel Tubular Beams - Tests And Design, Gregory J. Hancock, Kim J. R. Rasmussen Oct 1992

Stainless Steel Tubular Beams - Tests And Design, Gregory J. Hancock, Kim J. R. Rasmussen

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The paper presents tests on square and circular stainless steel tubular beams. An important part of the test programme was to quantify the increase in bending strength resulting from cold-work during the fabrication process. Tension and compression tests on coupons cut from finished tubes were also included in the test programme. Stress-strain curves for shear were obtained using the coupon test results and the concept of affinity factors. A design method is proposed for stainless steel tubular beams. The method incorporates the increase in strength produced by the cold-rolling process and is validated by comparing it to the test strengths. …

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Bending Strength Of Beams With Non-Linear Analysis, Pekka Salmi, Asko Talja Oct 1992

Bending Strength Of Beams With Non-Linear Analysis, Pekka Salmi, Asko Talja

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Bending strengths of open cross-section beams cold-formed from high-strength steel (HSS) are determined with non-linear analysis. Two kinds of beams are studied. The short beams are for examining the bending resistance of cross-sections and the long beams for studing the lateral buckling of open sections. The beams are modelled with shell elements and non-linear FEM analyses are carried out to predict the strengths of the models. Both material and geometrical non-linearities are included in the analyses. The results are compared with experimental results.

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Local And Distortional Buckling Of Thin-Walled Beams, Reynaud Serrette, Teoman Pekoz Oct 1992

Local And Distortional Buckling Of Thin-Walled Beams, Reynaud Serrette, Teoman Pekoz

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Recent research has characterized the behavior of panel beams with laterally unsupported compression flanges as either a complex local buckling mode or an overall buckling mode. Tests have shown that the behavior of the unsupported flange and web is similar to that of lateral buckling, except, rotation is enforced along the axis of the web and the tension flange--a behavior which may be described as distortional buckling. In the work described here, an analytical expression is presented for computing the elastic distortional buckling stress based on a model which treats the web and compression flange as an elastically restrained beam. …

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Lateral Buckling Of Singly Symmetric Beams, Teoman Pekoz Oct 1992

Lateral Buckling Of Singly Symmetric Beams, Teoman Pekoz

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

General solutions for the elastic lateral buckling moment of singly symmetric sections are studied. The studies include the effect of the location of the load on the section as well as the effect of moment gradients on the lateral buckling moment. Design provisions are outlined for the case of moment gradients.

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On Design Of Profiled Sheets With Varying Cross Sections, Laszlo Horvath, Miklos Nemeti, Bela Veroci Oct 1992

On Design Of Profiled Sheets With Varying Cross Sections, Laszlo Horvath, Miklos Nemeti, Bela Veroci

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A short review is given on the effective width concept and about its use for determining of the moment capacity of sheets. A modified method, taking into account the varying flexural rigidity along the spans, is described and illustrated on examples carried out on first -generation panels.

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Composite Slabs Analyzed By Block Bending Test, Li An, Krister Cederwall Oct 1992

Composite Slabs Analyzed By Block Bending Test, Li An, Krister Cederwall

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A new small-scale test, concrete block bending test, was carried out to determine the amount of shear stress and the slip distribution at the interface between the steel sheet and the concrete. The result was then used in the finite element analysis to predict the behaviour of composite slabs. Good agreement has been shown between the analytical results and measured results from the full-scale composite slabs.

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Design Of Channels Against Distortional Buckling, Y. B. Kwon, Gregory J. Hancock Oct 1992

Design Of Channels Against Distortional Buckling, Y. B. Kwon, Gregory J. Hancock

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Thin-walled lip-stiffened channel columns composed of high strength steel may fail in a distortional mode involving movement of the lip stiffener perpendicular to the flange plate it supports. In this report, test results for a simple lipped channel section(CH1) and an intermediate stiffened channel section (CH2) of thickness of approximately 1.1 mm (0.043 in) and 550 MPa (79.8 ksi) steel and undergoing distortional or mixed local-distortional buckling failure are compared with different design methods. The design methods compared are Australian Standard AS1538, EC3 Partl/ Annexe A, the ECCS Recommendations and the AISI Specification. In addition, new methods based on a …

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Some Applications Of Generalized Beam Theory, J. Michael Davies, Philip Leach Oct 1992

Some Applications Of Generalized Beam Theory, J. Michael Davies, Philip Leach

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Generalised Beam Theory (GBT) has been developed by Professor R Schardt and his colleagues at the University of Darmstadt in Germany. The definitive reference at the present time is a recent German text(1) which describes the first-order theory. For the analysis of cold-formed sections, second-order theory may be required and this is less well documented. This paper will attempt to describe the principles involved and illustrate them by means of some practical examples. GBT unifies the conventional theories for the analysis of prismatic thin-walled structural members within a consistent notation. It then extends them into new territory. Conventional beam theory …

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The Lateral Torsional Buckling Strength Of Cold-Formed Stainless Steel Lipped Channel Beams, P. Van Der Merwe, P. J. Bredenkamp, G. J. Van Den Berg Oct 1992

The Lateral Torsional Buckling Strength Of Cold-Formed Stainless Steel Lipped Channel Beams, P. Van Der Merwe, P. J. Bredenkamp, G. J. Van Den Berg

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The findings of an investigation into the lateral buckling strength of cold-formed singly-symmetric stainless steel beams are reported in this study. The singly-symmetric sections under consideration were lipped channel sections fabricated from a modified AISI stainless steel Type 409 designated 3CR12, a ferritic corrosion resisting steel. The purpose of this study was to compare the experimental strengths of singly-symmetric sections to the theoretical predictions proposed by the new ASCE Specification for the Design of Cold-Formed Stainless Steel Structural Members. It was concluded in this investigation that the tangent modulus approach adopted in the design specification for stainless steels, compared well …

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Testing And Design Of Bolted Connections In Cold Formed Steel Sections, F. Zadanfarrokh, E. R. Bryan Oct 1992

Testing And Design Of Bolted Connections In Cold Formed Steel Sections, F. Zadanfarrokh, E. R. Bryan

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A detailed analysis of the strength and rigidity of bolted connections in cold formed steel has been carried out. Design expressions are proposed that improve on the existing equations for bearing strength, and for the first time, quantify the rigidity of such connections. The effects on the design of bolted joints are described and it is shown how, by incorporating the proposed expressions, it is now possible to select the correct semirigid joint and achieve economy without having to resort to testing.

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Design Of C-Sections Against Deformational Lip Buckling, D. Buhagiar, J. C. Chapman, P. J. Dowling Oct 1992

Design Of C-Sections Against Deformational Lip Buckling, D. Buhagiar, J. C. Chapman, P. J. Dowling

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Deformational lip buckling is one of the considerations affecting the choice of cross-section dimensions which were adopted for the C-sectlon chord members of a space frame system. No guidance on lip buckling of channel sections is given in the current British design specification. A method was therefore required for determining the lip buckling resistance of the members when subjected to axial compression or bending. A design procedure was formulated in which the lips are represented as a strut on an elastic foundation, the stiffness of which depends on the deformational stiffness of the section. The critical buckling stress and the …

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New Asce Standards For Cold-Formed Steel Deck Slabs, Max L. Porter Oct 1992

New Asce Standards For Cold-Formed Steel Deck Slabs, Max L. Porter

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper presents highlights of the newly approved and printed ASCE Standard on the design and construction of composite floor deck slabs utilizing cold-formed steel. In 1992 four documents are being published including the following: • "Standard for the Structural Design of Composite Slabs"--ASCE3-92, • "Standard Practice for Construction and Inspection of Composite Slabs"-ASCE9-92, and • A separate commentary on each of the two above Standards. These above four documents stem from a previously published ASCE Standard entitled "Specifications for the Design and Construction of Composite Slabs" and the associated commentary thereon. The Steel Deck with Concrete Committee of the …

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