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Adaptive Information Filtering As A Means To Overcome Information Overload, Daniel R. Tauritz Jan 1996

Adaptive Information Filtering As A Means To Overcome Information Overload, Daniel R. Tauritz

Computer Science Faculty Research & Creative Works

Information Filtering is concerned with filtering data streams in such a way as to leave only pertinent data (information) to be perused. When the data streams are produced in a changing environment (as most if not all are) the filtering has to adapt too in order to remain effective. Adaptive Information Filtering (AIF) is concerned with filtering in changing environments. The changes may occur both on the transmission side (the nature of the streams can change), and on the reception side (the interest of a user can change). The thesis research described in this paper combines trigram analysis, clustering, and …

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High-Temperature Thermopower Of And Related Systems, D. Marsh, Paul Ernest Parris Jan 1996

High-Temperature Thermopower Of And Related Systems, D. Marsh, Paul Ernest Parris

Physics Faculty Research & Creative Works

We investigate theoretically the high-temperature Seebeck coefficient in LaMnO3 and related transition-metal-oxide perovskites. Our analysis employs a model for small polaron conduction that takes into account the electronic structure of the 3d orbitals of B-site transition-metal cations, yielding expressions for systems in which conduction occurs through the eg transition-metal manifold. Limiting forms for the Seebeck coefficient as a function of carrier concentration and site degeneracy are identified for strong and weak Coulomb interactions between electrons on the same and neighboring sites. Results are applied to an analysis of experimental data for LaMnO3, the La1-xCa …

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Data Report For The 1993 Los Angeles Region Seismic Experiment (Larse93), Southern California: A Passive Study From Seal Beach Northeastward Through The Mojave Desert, Monica D. Kohler, Paul M. Davis, Kelly H. Liu, Mark Benthien, Stephen S. Gao, Gary S. Fuis, Robert W. Clayton, David Okaya, James Mori Jan 1996

Data Report For The 1993 Los Angeles Region Seismic Experiment (Larse93), Southern California: A Passive Study From Seal Beach Northeastward Through The Mojave Desert, Monica D. Kohler, Paul M. Davis, Kelly H. Liu, Mark Benthien, Stephen S. Gao, Gary S. Fuis, Robert W. Clayton, David Okaya, James Mori

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This report contains a description of the first part of the Los Angeles Region Seismic Experiment (LARSE). To date, LARSE has consisted of two experiments: passive, which took place in fall, 1993 (LARSE93), and active, which took place in fall, 1994 (LARSE94). The goal of the 1993 experiment was to collect waveform data from local and distant earthquakes to obtain three-dimensional images of lower crust and upper mantle structure in Southern California, particularly under the San Gabriel Mountains and across the San Andreas fault. During LARSE93, approximately 88 stations were deployed in a 175-km-long, linear array across the Los Angeles …

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Influence Of Formation Processes On Oblique Detonation Wave Stabilization, K. Ghorbanian, J. D. Sterling Jan 1996

Influence Of Formation Processes On Oblique Detonation Wave Stabilization, K. Ghorbanian, J. D. Sterling

Business and Information Technology Faculty Research & Creative Works

In this article we report steady, two-dimensional, inviscid solutions for the near field and far field of a supersonic reactive flow over a variable-double-ramp geometry. The incident shock wave compresses and heats the reactants that will combust after flowing some induction length. Upon reaction, a detonation wave forms and intersects the leading wave at some distance from the ramp surface. In this article, reaction-polar diagrams are developed, and the detonation branch solutions are used to investigate the wave interaction processes that may lead to a steady three-wave structure. By considering this formation process new oblique detonation wave stabilization criteria based …

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Optimization Of The Discriminatory Power Of A Trigram Based Document Clustering Algorithm Using Evolutionary Computation, Daniel R. Tauritz Jan 1996

Optimization Of The Discriminatory Power Of A Trigram Based Document Clustering Algorithm Using Evolutionary Computation, Daniel R. Tauritz

Computer Science Faculty Research & Creative Works

No abstract provided.

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Effective-Medium Theory For The Electric-Field Dependence Of The Hopping Conductivity Of Disordered Solids, Paul Ernest Parris, B. D. Bookout Jan 1996

Effective-Medium Theory For The Electric-Field Dependence Of The Hopping Conductivity Of Disordered Solids, Paul Ernest Parris, B. D. Bookout

Physics Faculty Research & Creative Works

We derive a general effective-medium theory for describing biased diffusion on a bond-disordered lattice in the presence of an external driving field. In our theory, the effective medium associated with a disordered d-dimensional lattice is characterized, for each value of the applied field, by 2d independent parameters describing, respectively, the net drift velocity vv and the diffusion constant Dvv describing the spread of a carrier packet about its mean value, for each of the d crystal axes. The theory correctly predicts the velocity transition occurring in an exactly soluble model studied by Derrida and, in contrast to other …

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The Rollamo 1996, University Of Missouri - Rolla Jan 1996

The Rollamo 1996, University Of Missouri - Rolla

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No abstract provided.

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High-Frequency Spin Waves In Yba₂Cu₃O6.15>/Sub>, Stephen M. Hayden, Gabriel Aeppli, Toby G. Perring, Herbert A. Mook, Fatih Dogan Jan 1996

High-Frequency Spin Waves In Yba₂Cu₃O6.15>/Sub>, Stephen M. Hayden, Gabriel Aeppli, Toby G. Perring, Herbert A. Mook, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Pulsed neutron spectroscopy is used to absolute measurements of the dynamic magnetic susceptibility of insulating YBa2Cu3O6.15. Acoustic and optical modes, derived from inand out-of-phase oscillation of spins in adjacent CuO2 planes, dominate the spectra and are observed up to 250 meV. The optical modes appear first at 74±5 meV. Linear-spin-wave theory gives an excellent description of the data and yields intralayer and interlayer exchange constants of J∥=125±5 meV and J⊥=11±2 meV, respectively, and a spin-wave intensity renormalization ZΧ=0.4±0.1.

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Liquid Phase Behaviour In Nonstoichiometric Calcium-Doped Lanthanum Chromites, J. D. Carter, M. M. Nasrallah, Harlan U. Anderson Jan 1996

Liquid Phase Behaviour In Nonstoichiometric Calcium-Doped Lanthanum Chromites, J. D. Carter, M. M. Nasrallah, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The sinter ability of (La,Ca)CrO3 is analyzed by comparing the liquid phase behavior in A-site excess and A-site deficient compositions (referring to the ABO3 formula). The analysis shows that a series of A-site excess and deficient compositions form distinct liquid phases belonging to the CaO-Cr2O3 phase system. Although both series experience grain growth and densification due to the presence of a liquid phase, the A-site excess compositions exhibit greater shrinkage and sinter to closed porosity, whereas the A-site deficient compositions remain porous. During the final stages of sintering, surplus liquid from the A-site excess material exudes to the free-surface forming …

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Neutron Diffraction And Magnetic Studies Of Nd₂Fe₁₇₋ₓtₓ (T=Si, Mn) Alloys, William B. Yelon, Z. Hu, Mingxing Chen, H. Luo, F. Pourarian, Peter C. Ezekwenna, G. K. Marasinghe, K. H. J. Buschow, D. P. Middleton, William Joseph James Jan 1996

Neutron Diffraction And Magnetic Studies Of Nd₂Fe₁₇₋ₓtₓ (T=Si, Mn) Alloys, William B. Yelon, Z. Hu, Mingxing Chen, H. Luo, F. Pourarian, Peter C. Ezekwenna, G. K. Marasinghe, K. H. J. Buschow, D. P. Middleton, William Joseph James

Physics Faculty Research & Creative Works

We have carried out neutron and magnetic studies on Nd2Fe17-xTx (T=Si, Mn) alloys. the unit cell of the compounds contracts with both Si and Mn substitution. Si atoms avoid the 6c site, prefer the 18h site strongly, fill the 9d site steadily and fill the 18f site only at relatively high Si concentration. Mn atoms avoid the 9d sites but prefer the 6c site strongly, while the 18f site and 18h site fill slowly. the Si site occupancies appear to be dominated by the crystal environment while the Mn site occupancies are dominated by steric …

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Single Ionization Of He By Low-Velocity Protons And [Formula Presented]: Ejected Electron Momentum Distributions, S. D. Kravis, M. Abdallah, C. L. Cocke, C. D. Lin, M. Stockli, B. Walch, Y. D. Wang, Ronald E. Olson, V. D. Rodríguez, W. Wu, M. Pieksma, N. Watanabe Jan 1996

Single Ionization Of He By Low-Velocity Protons And [Formula Presented]: Ejected Electron Momentum Distributions, S. D. Kravis, M. Abdallah, C. L. Cocke, C. D. Lin, M. Stockli, B. Walch, Y. D. Wang, Ronald E. Olson, V. D. Rodríguez, W. Wu, M. Pieksma, N. Watanabe

Physics Faculty Research & Creative Works

A technique for electron spectroscopy which yields full two-dimensional momentum distributions for continuum electrons has been used to study ejected electrons from single ionization of He by [Formula Presented] and proton projectiles at low velocities. Projectile velocities of 1.63, 1.38, and 1.16 a.u. for [Formula Presented] and 2.39, 1.71, 1.15,. 85, and 0.63 a.u. for protons were used. All spectra show much broader distributions along the beam than transverse to the beam. For the case of proton bombardment, the spectra are strongly influenced by both target and projectile potentials, maximizing near the velocity of the saddle in the potential between …

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Attention In Direct And Indirect Memory Tasks With Short- And Long-Term Probes, Ronald Thomas Kellogg, Christopher Newcombe, Darren Kammer, Katherine Schmitt Jan 1996

Attention In Direct And Indirect Memory Tasks With Short- And Long-Term Probes, Ronald Thomas Kellogg, Christopher Newcombe, Darren Kammer, Katherine Schmitt

Psychological Science Faculty Research & Creative Works

In two experiments, college students verified the answers to addition problems as their primary task while simultaneously viewing a word or nonword. The degree of attention allocated to the verbal stimulus varied depending on the difficulty of the problem and the instructions given. After each problem, a test probe assessed either a direct test of recognition memory or an indirect test of repetition priming in lexical decision at lags of 0, 1, or 8 intervening trials. The degree of attention at encoding and lag strongly affected recognition sensitivity (d′), but only lag affected recognition latencies. The repetition-priming effect neither declined …

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Quantum Version Of A Spherical Model: Crossover From Quantum To Classical Critical Behavior, Thomas Vojta Jan 1996

Quantum Version Of A Spherical Model: Crossover From Quantum To Classical Critical Behavior, Thomas Vojta

Physics Faculty Research & Creative Works

We investigate a quantum version of the spherical model which is obtained from the classical Berlin-Kac spherical model by a simple canonical quantization scheme. We find a complete solution of the model for short-range as well as for long-range interactions. At finite temperatures the critical behavior is the same as in the classical spherical model whereas at zero temperature we find a quantum phase transition characterized by new critical exponents. Based on a functional-integral representation of the partition function the free energy of the model is shown to be equivalent to that of the nonlinear σ model in the limit …

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Collective Behavior Of Electrons Emitted In Multiply Ionizing Collisions Of 5.9 Mev/U U⁶⁵⁺ With Ne, M. Unverzagt, R. Moshammer, W. Schmitt, Ronald E. Olson, P. Jardin, V. Mergel, J. Ullrich, H. Schmidt-Böcking Jan 1996

Collective Behavior Of Electrons Emitted In Multiply Ionizing Collisions Of 5.9 Mev/U U⁶⁵⁺ With Ne, M. Unverzagt, R. Moshammer, W. Schmitt, Ronald E. Olson, P. Jardin, V. Mergel, J. Ullrich, H. Schmidt-Böcking

Physics Faculty Research & Creative Works

The collective behavior of up to six target electrons emitted in a single collision of 5.9 MeV/u U65+ with Ne was investigated using high-resolution recoil-ion momentum spectroscopy. With an increasing number of ejected electrons the recoil ions are increasingly scattered into the backward direction, providing evidence that the electrons are emitted into the forward hemisphere. Their mean longitudinal sum energy varies from about 5 eV for single ionization up to 1.1 keV for Ne6+. Experimental recoil-ion momentum distributions are in excellent agreement with results of classical many-particle calculations. © 1996 The American Physical Society.

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Measurements Of Recoil And Projectile Momentum Distributions For 19-Mev [Formula Presented] + Ne Collisions, V. Frohne, S. Cheng, R. M. Ali, M. L.A. Raphaelian, C. L. Cocke, Ronald E. Olson Jan 1996

Measurements Of Recoil And Projectile Momentum Distributions For 19-Mev [Formula Presented] + Ne Collisions, V. Frohne, S. Cheng, R. M. Ali, M. L.A. Raphaelian, C. L. Cocke, Ronald E. Olson

Physics Faculty Research & Creative Works

The collision system of 19-MeV [Formula Presented] on Ne has been studied using recoil and projectile momentum spectroscopy. For each event, identified by final recoil and projectile charge state, the three-dimensional momentum vector of the recoil ion and the transverse momentum vector of the projectile ion were measured. The transverse momenta of the recoil and projectile ions were found to be equal in magnitude and opposite in direction, indicating that the transverse momentum exchange is dominated by interactions between the two ion cores. The transverse momentum distributions are well described by nCTMC calculations. The longitudinal momentum distributions of the recoil …

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Doubly Differential Final-State Momentum Distributions Of The Ionization Products In Collision Of Bare Ions With Hydrogen, Lokesh C. Tribedi, P. Richard, Y. D. Wang, C. D. Lin, Ronald E. Olson Jan 1996

Doubly Differential Final-State Momentum Distributions Of The Ionization Products In Collision Of Bare Ions With Hydrogen, Lokesh C. Tribedi, P. Richard, Y. D. Wang, C. D. Lin, Ronald E. Olson

Physics Faculty Research & Creative Works

In this paper recoil-ion production cross sections are presented differential in recoil-ion longitudinal momentum and electron emission angle in ionization of atomic and molecular hydrogen by bare ion projectiles. A new formulation for constructing these double differential distributions from the measured electron double differential cross sections is used. A novel feature is the separation of two different branches of the recoil-ion longitudinal momentum distribution corresponding to soft and hard collision mechanisms of ionization. The single differential distributions have also been derived. © 1996 The American Physical Society.

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Imaging Of Saddle Point Electron Emission In Slow, R. Dörner, H. Khemliche, M. H. Prior, C. L. Cocke, J. A. Gary, Ronald E. Olson, V. Mergel, J. Ullrich, H. Schmidt-Böcking Jan 1996

Imaging Of Saddle Point Electron Emission In Slow, R. Dörner, H. Khemliche, M. H. Prior, C. L. Cocke, J. A. Gary, Ronald E. Olson, V. Mergel, J. Ullrich, H. Schmidt-Böcking

Physics Faculty Research & Creative Works

The two-dimensional velocity distribution of electrons emitted in 5-15 keV p - He collisions has been measured for completely determined motion of the nuclei, that is, as a function of the impact parameter and in a well defined scattering plane. The electrons are emitted preferentially in the scattering plane and in the forward direction. The velocity distributions show sharp structures that vary strongly with impact parameter and projectile velocity. The results are compared to classical trajectory calculations. © 1996 The American Physical Society.

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An Inline Optical Electron Polarimeter, K. W. Trantham, Timothy J. Gay, R. J. Vandiver Jan 1996

An Inline Optical Electron Polarimeter, K. W. Trantham, Timothy J. Gay, R. J. Vandiver

Physics Faculty Research & Creative Works

The design and operation of a simple inline optical electron polarimeter is presented. It is based on exchange excitation of ground state neon atoms. The electron polarization is determined from the degree of circular polarization of the subsequent 2p53p 3D3→2p53s 3P2 (6402 Å) fluorescence. This device can characterize both longitudinally and transversely polarized electron beams in a nondestructive fashion, and is inexpensive and easily constructed. © 1996 American Institute of Physics.

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Double Ionization Of Helium And Neon For Fast Heavy-Ion Impact: Correlated Motion Of Electrons From Bound To Continuum States, R. Moshammer, J. Ullrich, H. Kollmus, W. Schmitt, M. Unverzagt, O. Jagutzki, V. Mergel, H. Schmidt-Böcking, R. Mann, C. J. Woods, Ronald E. Olson Jan 1996

Double Ionization Of Helium And Neon For Fast Heavy-Ion Impact: Correlated Motion Of Electrons From Bound To Continuum States, R. Moshammer, J. Ullrich, H. Kollmus, W. Schmitt, M. Unverzagt, O. Jagutzki, V. Mergel, H. Schmidt-Böcking, R. Mann, C. J. Woods, Ronald E. Olson

Physics Faculty Research & Creative Works

Double ionization of He and Ne by charged particle impact was explored in kinematically complete experiments measuring the final momenta of the two emerging electrons(Pfe1, Pfe2) and of the recoiling target ion PRf. The momentum transfer from the 3.6 MeV/u Se28+projectile to the electrons is found to be negligibly small. Thus distinct patterns observed in the Pfe1- versus - Pfe2spectra sensitively reflect the details of the electrons' correlated motion. Classical calculations reasonably describe the data only when the (e-e)interaction during the ionization reaction is included. © 1996 The American Physical Society.

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Optical Electron Polarimetry With Heavy Noble Gases, Timothy James Gay, J. E. Furst, K. W. Trantham, W. M.K.P. Wijayaratna Jan 1996

Optical Electron Polarimetry With Heavy Noble Gases, Timothy James Gay, J. E. Furst, K. W. Trantham, W. M.K.P. Wijayaratna

Physics Faculty Research & Creative Works

We have measured the polarization of fluorescence emitted by the noble gases He, Ne, Ar, Kr, and Xe following impact excitation by polarized electrons. In He, the [Formula Presented]P→[Formula Presented]S transition was studied; in the heavy noble gases the [Formula Presented](n+1)p[Formula Presented]→[Formula Presented](n+1)s[Formula Presented] transitions were analyzed. We investigated these transitions as candidates for efficient optical electron polarimetry and found that, because of their larger excitation cross sections and analyzing power, the heavy noble gases are superior to He, which had been used previously as a polarimetric target. Several issues with regard to the implementation and accuracy of optical electron …

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Interaction Between Millimeter Oscillations And Monocrystal Hexagonal Ferrites With Modulated Resonance Frequency, Alexander A. Kitaytsev, Marina Koledintseva Jan 1996

Interaction Between Millimeter Oscillations And Monocrystal Hexagonal Ferrites With Modulated Resonance Frequency, Alexander A. Kitaytsev, Marina Koledintseva

Electrical and Computer Engineering Faculty Research & Creative Works

Investigation of non-linear stable effects taking place at ferromagnetic resonance (FMR) in monocrystal arbitrarily oriented hexagonal ferrite resonators (HFR) with controlled (modulated) resonance frequency is an urgent problem. The presented analysis is based on two approaches: the “quasistatic” approach using the static tensor of the HFR magnetic susceptibility and the “dynamic” one based on the solution of the magnetization vector motion equation (MVME) with varying time coefficients due to modulated magnetization field or HFR angle of orientation. The first approach is valid at low modulation frequencies (in comparison with the relaxation frequency of the HFR) and the second one can …

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Phytoremediation: Plant Uptake Of Atrazine And Role Of Root Exudates, Joel G. (Gerard) Burken, Jerald L. Schnoor Jan 1996

Phytoremediation: Plant Uptake Of Atrazine And Role Of Root Exudates, Joel G. (Gerard) Burken, Jerald L. Schnoor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Phytoremediation is an Emerging Technology for Degradation of Organic Chemicals. the Potential of Phytoremediation in the Cleanup of Contaminated Sites and Prevention of Non-Point-Source Pollution Was Examined with the Pesticide Atrazine in Two Experimental Systems. Uptake Was Determined in Batch Experiments with 14C Ring-Labeled Atrazine and Hybrid Poplar Trees Grown in Two Soil Types. Mineralization Was Studied Utilizing Soil Microcosms with the Addition of Root Exudates. Results Indicate that Poplar Cuttings Were Able to Uptake the Majority of Applied Atrazine that Was Not Tightly Sorbed to the Organic Fraction of the Soil, with No Detectable Adverse Effects to the Trees. …

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On Seismic Displacements Of Rigid Retaining Walls, Yingwei Wu, Shamsher Prakash Jan 1996

On Seismic Displacements Of Rigid Retaining Walls, Yingwei Wu, Shamsher Prakash

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Rigid retaining walls experience both sliding and rocking displacement during earthquakes. Richards and Elms' (1979) method incorporates only sliding displacements in design. A realistic method of computing both sliding and rocking displacements of the walls based on nonlinear soil properties both for the base soil and backfill was developed by Rafnsson and Prakash (1994). A design procedure based on this method was then developed by Prakash. et al (1995, b). Comparisons of the displacements of typical walls by both the methods have been made. Also, typical field data from recent earthquakes has been analyzed to compare the observed displacements with …

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Behavior Of Low Ductility Steels In Cold-Formed Steel Connections, S. Seleim, Roger A. Laboube Jan 1996

Behavior Of Low Ductility Steels In Cold-Formed Steel Connections, S. Seleim, Roger A. Laboube

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Accepted design approaches for the strength of a steel connection rely on adequate ductility of the connected parts. In cold-formed steel connection design, adequate ductility is defined by the Specification for the Design of Cold-Formed Steel Members. To assess the influence of low ductility steels, i.e. steels not meeting the specification ductility requirements, single lap bolted connections were studied. The experimental study reflected key connection strength parameters: edge distance, sheet thickness, sheet width, bolt pattern, Fu/Fy, and percentage elongation. Test results indicate that failure modes in low ductility steels are inconsistent with observed failure modes in adequate ductility steels. It …

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Performance Of Laminated Glass Units Under Simulated Windborne Debris Impacts, Richard A. Behr, Paul A. Kremer Jan 1996

Performance Of Laminated Glass Units Under Simulated Windborne Debris Impacts, Richard A. Behr, Paul A. Kremer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Severe windstorm events such as Hurricane Andrew in 1992 have underscored the vulnerability of building envelopes to breaching under the combined effects of windborne debris impacts and wind pressures. Damage to building interiors and disruption of building functions are exacerbated greatly when building envelopes are breached. When the inner glass ply in a laminated glass window unit is unbroken, the integrity of that part of the building envelope is preserved - provided that the inner glass ply has sufficient resistance to subsequent positive and negative wind pressures. In an effort to develop glazing systems that are resistant to breaching due …

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Biodegradation Of Nonionic Surfactants And Effects Of Oxidative Pretreatment, Craig D. Adams, S. Spitzer, R. M. Cowan Jan 1996

Biodegradation Of Nonionic Surfactants And Effects Of Oxidative Pretreatment, Craig D. Adams, S. Spitzer, R. M. Cowan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The aerobic biodegradability of nonionic, ethoxylated surfactants and model compounds, and the effect of advanced oxidation pretreatment on the biodegradability of the biorefractory surfactants were examined. Bioassays conducted using a mixed microbial seed showed that the linear primary alcohol ethoxylates, the fatty acid ethoxylates, and also polyethylene glycol were all degradable. The biomineralization of the linear secondary alcohol ethoxylate, ethylene oxide/propylene oxide block copolymer, and alkylphenol ethoxylate was observed to be inhibited to varying degrees. Additional bioassays were conducted on model compounds to examine the effect of specific structural components on biodegradability. Advanced oxidation pretreatment using hydrogen peroxide in combination …

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Multiobjective Optimization Of Structures With And Without Control, Franklin Y. Cheng, Dan Li Jan 1996

Multiobjective Optimization Of Structures With And Without Control, Franklin Y. Cheng, Dan Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A multiobjective optimization algorithm is introduced, and the effect of different objective functions on structural design is investigated. The basic idea of this approach is to support the decisionmaker by directly selecting the best compromise solution from the Pareto optimal solutions. A payoff matrix is first constructed by optimizing each objective function subject to the given constraints; a substitute function is then formed. Under the original constraint conditions, maximizing the substitute function gives the best compromise solution. This research shows that multiobjective optimization should be carried out to obtain a rational structural design. Two structural optimal design examples - one …

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Comparison Of Linear And Nonlinear Seismic Drift Histories For Midrise Steel Frames, K. Z. Truman, C. Pantelides, Richard A. Behr, Abdeldjelil Belarbi Jan 1996

Comparison Of Linear And Nonlinear Seismic Drift Histories For Midrise Steel Frames, K. Z. Truman, C. Pantelides, Richard A. Behr, Abdeldjelil Belarbi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The linear and nonlinear seismic responses for two midrise office buildings of five- and 24-storeys were generated by two independent research groups using three commercial analysis packages, ABAQUS, SAP90 and DRAIN-2DX. The results indicate that a variability of up to 25% occurred between the independent research groups' seismic responses. Originally, these models and analyses were generated for the purpose of aiding in the development of load histories for the seismic testing of architectural glass at the University of Missouri-Rolla. The independent researchers were provided with the same structures, accelerograms and basic modelling assumptions and were directed to perform both linear …

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Effects Of Accelerated Weathering On Architectural Laminated Glass In A Windstorm Environment, Richard A. Behr, Joseph E. Minor, Paul A. Kremer Jan 1996

Effects Of Accelerated Weathering On Architectural Laminated Glass In A Windstorm Environment, Richard A. Behr, Joseph E. Minor, Paul A. Kremer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An experimental study was conducted to assess the serviceability and ultimate limit state behavior of a fully glazed architectural laminated glass system under accelerated weathering conditions. Glazed specimens included heat-strengthened laminated glass with a low-emissivity, metallic solar coating on one glass surface next to the polyvinyl butyral interlayer. The laminated glass units were anchored to the aluminum curtain wall frame with a perimeter anchor bead of medium-modulus structural silicone sealant. Accelerated weathering was performed in a manner similar to the provisions of ASTM E773-88 and E774-92. All specimens (weathered and unweathered) were then subjected to a severe windstorm simulation test, …

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Bending And Shear Behavior Of Web Elements With Openings, M. Y. Shan, Roger A. Laboube, Wei-Wen Yu Jan 1996

Bending And Shear Behavior Of Web Elements With Openings, M. Y. Shan, Roger A. Laboube, Wei-Wen Yu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Cold-formed steel C-sections are frequently used as wall studs and floor joists in both commercial and residential construction. To facilitate installation of ancillary systems such as electrical wiring and plumbing, the C-section is manufactured with a web opening. Although the opening offers construction advantages, it may degrade the structural integrity of the member. To quantify the degrading effect of a web opening, a study has been conducted at the University of Missouri-Rolla (UMR). The UMR study included the loading conditions of bending, shear, web crippling, and the combinations thereof. This paper summarizes the results of an experimental study which addressed …

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