Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Missouri University of Science and Technology

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 12991 - 13020 of 21751

Full-Text Articles in Engineering

Rapid Measurement Of Indoor Mass-Transfer Coefficients, Glenn Morrison, Zhao Ping, Deborah J. Wiseman, Maneerat Ongwandee, Hong Chang, Julie Portman, Shekhar Regmi Jan 2003

Rapid Measurement Of Indoor Mass-Transfer Coefficients, Glenn Morrison, Zhao Ping, Deborah J. Wiseman, Maneerat Ongwandee, Hong Chang, Julie Portman, Shekhar Regmi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Indoor air pollutant concentrations can be influenced by how rapidly species are transported to and from surfaces. Consequently, a greater understanding of indoor transport phenomena to surfaces improves estimates of human exposure to indoor air pollutants. Here, we introduce two methods of rapidly and directly measuring species fluxes at indoor surfaces, allowing us to evaluate the transport-limited deposition velocity, vt (a mass-transfer coefficient). The deposition velocity sensor (DeVS) method employs a small microbalance coated with a pure hydrocarbon, preferably octadecane. We quantify flux (or evaporation rate) of the hydrocarbon into a room by observing the rate of mass loss …

Go to article

A Finite Subelement Generalization Of The Variational Nodal Method, M. A. Smith, Nicholas Tsoulfanidis, E. E. Lewis, G. Palmiotti, T. A. Taiwo Jan 2003

A Finite Subelement Generalization Of The Variational Nodal Method, M. A. Smith, Nicholas Tsoulfanidis, E. E. Lewis, G. Palmiotti, T. A. Taiwo

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The variational nodal method is generalized by dividing each spatial node into a number of triangular finite elements designated as subelements. the finite subelement trial functions allow for explicit geometry representations within each node, thus eliminating the need for nodal homogenization. the method is implemented within the Argonne National Laboratory code VARIANT and applied to two-dimensional multigroup problems. Eigenvalue and pin-power results are presented for a four-assembly Organization for Economic Cooperation and Development/Nuclear Energy Agency benchmark problem containing enriched UO2 and mixed oxide fuel pins. Our seven-group model combines spherical or simplified spherical harmonic approximations in angle with isoparametric linear …

Go to article

Adaptive-Critic-Based Optimal Neurocontrol For Synchronous Generators In A Power System Using Mlp/Rbf Neural Networks, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2003

Adaptive-Critic-Based Optimal Neurocontrol For Synchronous Generators In A Power System Using Mlp/Rbf Neural Networks, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel optimal neurocontroller that replaces the conventional controller (CONVC), which consists of the automatic voltage regulator and turbine governor, to control a synchronous generator in a power system using a multilayer perceptron neural network (MLPN) and a radial basis function neural network (RBFN). The heuristic dynamic programming (HDP) based on the adaptive critic design technique is used for the design of the neurocontroller. The performance of the MLPN-based HDP neurocontroller (MHDPC) is compared with the RBFN-based HDP neurocontroller (RHDPC) for small as well as large disturbances to a power system, and they are in turn compared …

Go to article

An Extended Kalman Filter (Ekf) Approach On Fuzzy System Optimization Problem, Nian Zhang, Donald C. Wunsch Jan 2003

An Extended Kalman Filter (Ekf) Approach On Fuzzy System Optimization Problem, Nian Zhang, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Optimizing the membership functions of a fuzzy system can be viewed as a system identification problem for a nonlinear dynamic system. Basically, we can view the optimization of fuzzy membership functions as a weighted least-squares minimization problem, where the error vector is the difference between the fuzzy system outputs and the target values for those outputs. The extended Kalman filter algorithm is a good choice to solve this system identification problem, not only because it is a derivative-based algorithm that is suitable to solve the weighted least-squares minimization problem, but also because of its appealing predictor-corrector feature for nonlinear system …

Go to article

Capacitor Voltage Balancing In Full Binary Combination Schema Flying Capacitor Multilevel Inverters, Keith Corzine, X. Kou Jan 2003

Capacitor Voltage Balancing In Full Binary Combination Schema Flying Capacitor Multilevel Inverters, Keith Corzine, X. Kou

Electrical and Computer Engineering Faculty Research & Creative Works

Recently, the full binary combination schema (FBCS) method has been introduced to control the flying capacitor multilevel inverter. This method has the primary advantage that the number of voltage levels can be increased for a given number of semiconductor devices when compared to the conventional control methods. However, due to the difficulty of balancing the capacitors, the new schema requires fixed floating sources to provide the DC voltages. This paper reveals an approach of balancing the capacitors, thus expanding the application fields of FBCS inverters to the family of the flying capacitor multilevel inverters under the condition of choosing a …

Go to article

Computational Enhancement Of Genetic Algorithm Via Control Device Pre-Selection Mechanism For Power System Reactive Power/Voltage Control, G. Krost, Ganesh K. Venayagamoorthy, G. A. Bakare, U. O. Aliyu Jan 2003

Computational Enhancement Of Genetic Algorithm Via Control Device Pre-Selection Mechanism For Power System Reactive Power/Voltage Control, G. Krost, Ganesh K. Venayagamoorthy, G. A. Bakare, U. O. Aliyu

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the application of a novel and computationally enhances genetic algorithm (GA) for solving the reactive power dispatch problem is presented. In order to attain a significant reduction in the computational time of GA, a systematic procedure of reactive power control device pre-selection mechanism is herein proposed to choose a-priori subsets of the available control devices, which maximally influence buses experiencing voltage limit violations. The GA reactive power dispatch module then accesses such judiciously pre-selected control device candidates to determine their optimal settings. A pragmatic scheme aimed at further curtailing the number of the final control actions entertained …

Go to article

Dual Heuristic Programming Excitation Neurocontrol For Generators In A Multimachine Power System, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 2003

Dual Heuristic Programming Excitation Neurocontrol For Generators In A Multimachine Power System, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The design of nonlinear optimal neurocontrollers that replace the conventional automatic voltage regulators for excitation control of turbogenerators in a multimachine power system is presented in this paper. The neurocontroller design is based on dual heuristic programming (DHP), a powerful adaptive critic technique. The feedback variables are completely based on local measurements from the generators. Simulations on a three-machine power system demonstrate that DHP-based neurocontrol is much more effective than the conventional proportional-integral-derivative control for improving dynamic performance and stability of the power grid under small and large disturbances. This paper also shows how to design optimal multiple neurocontrollers for …

Go to article

Method Of Scrapping Steel Structures, G. E. Shapiro, Paul Nicholas Worsey Jan 2003

Method Of Scrapping Steel Structures, G. E. Shapiro, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

A method of breaking up a structure for the recovery of steel as scrap. The structure has steel plates forming a compartment secured to framing in the compartment. The method includes at least partially filling the compartment with a substantially incompressible substance and placing explosive in the substance in the compartment. The explosive is sufficient and adapted on detonation thereof to pressurize the compartment to the extent of causing separation of the plates from the framing. The method further includes detonating the explosive.

Go to article

Power System Basics For Business Professionals In Our Industry, G. Gross, Peter W. Sauer, Mariesa Crow Jan 2003

Power System Basics For Business Professionals In Our Industry, G. Gross, Peter W. Sauer, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

The rapid changes in the business aspects of the electricity industry are making it necessary for engineers to communicate more frequently and more effectively with nontechnical people. With the heightened interest in electric power and energy systems, a broad range of "nonpower" people has expressed a need for a primer on power engineering fundamentals presented in a nontechnical manner. In response, the IEEE Power Engineering Society sponsored the preparation of such a course targeted towards the "business professional." The first offering of this course was in July 2002 as part of the IEEE PES Summer Meeting in Chicago. Power System …

Go to article

Rate-Based End-To-End Congestion Control Of Multimedia Traffic In Packet Switched Networks, Mingsheng Peng, S. R. Subramanya, Jagannathan Sarangapani Jan 2003

Rate-Based End-To-End Congestion Control Of Multimedia Traffic In Packet Switched Networks, Mingsheng Peng, S. R. Subramanya, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes an explicit rate-based end-to-end congestion control mechanism to alleviate congestion of multimedia traffic in packet switched networks such as the Internet. The congestion is controlled by adjusting the transmission rates of the sources in response to the feedback information from destination such as the buffer occupancy, packet arrival rate and service rate at the outgoing link, so that a desired quality of service (QoS) can be met. The QoS is defined in terms of packet loss ratio, transmission delay, power, and network utilization. Comparison studies demonstrate the effectiveness of the proposed scheme over New-Reno TCP (a variant …

Go to article

Computer Simulations And Neutron Reflectivity Of Proteins At Interfaces, Amol A. Mungikar, Daniel Forciniti Dec 2002

Computer Simulations And Neutron Reflectivity Of Proteins At Interfaces, Amol A. Mungikar, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Computer simulations in conjunction with neutron reflectivity is an excellent combination for the study of biological materials at solid-liquid interfaces: Both techniques have excellent resolution levels (Ångströms) and they are mature. A stronger interaction between physicists and biologists will allow the use of these two approaches in topics of biological-biomedical interest.

Go to article

Novel General Expressions That Describe The Behavior Of The Height Equivalent Of A Theoretical Plate In Chromatographic Systems Involving Electrically-Driven And Pressure-Driven Flows, B. A. Grimes, S. Lüdtke, K. K. Unger, Athanasios I. Liapis Dec 2002

Novel General Expressions That Describe The Behavior Of The Height Equivalent Of A Theoretical Plate In Chromatographic Systems Involving Electrically-Driven And Pressure-Driven Flows, B. A. Grimes, S. Lüdtke, K. K. Unger, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Novel general expressions are constructed and presented that describe the behavior of the height equivalent of a theoretical plate (plate height), H, as a function of the linear velocity, Vx, along the axis, x, of the column and the kinetic parameters that characterize the mass transfer and adsorption mechanisms in chromatographic columns. Open tube capillaries as well as columns packed with either non-porous or porous particles are studied. The porous particles could have unimodal or bimodal pore-size distributions and intraparticle convective fluid flow and pore diffusion are considered. The expressions for the plate height, H, presented in this work could …

Go to article

Nonstoichiometry And Electrical Transport In Sc-Doped Zirconia, Igor Kosacki, Harlan U. Anderson, Yasunobu Mizutani, Kenji Ukai Dec 2002

Nonstoichiometry And Electrical Transport In Sc-Doped Zirconia, Igor Kosacki, Harlan U. Anderson, Yasunobu Mizutani, Kenji Ukai

Materials Science and Engineering Faculty Research & Creative Works

The results of electrical conductivity measurements on ZrO2: Sc (ScSZ) ceramics as a function of oxygen activity and temperature are presented. The influence of the microstructure on electrical transport is discussed and the experimental data for dense microcrystalline specimens have been compared with those obtained for dense nanocrystalline thin films. From these results the electronic and ionic contribution to the electrical transport has been determined and correlated with microstructure. It has been found that nanocrystalline ScSZ films possess quite different nonstoichiometry compared with that observed for microcrystalline specimens in the fact that the electronic conductivity is enhanced so …

Go to article

Phase Diagram For Stripes In Yba2cu3o6+X Superconductors, Herbert A. Mook, Fatih Dogan Dec 2002

Phase Diagram For Stripes In Yba2cu3o6+X Superconductors, Herbert A. Mook, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Neutron scattering has been used to measure the charge and spin structure in the YBa2Cu3O6+x superconductors. Incommensurate static charge ordering is found at low doping levels while only charge fluctuations are found at higher doping. The spin structure is complex with both a commensurate resonance and incommensurate structure observed at low temperatures. The scattering results are used to construct a phase diagram for stripes in the YBa2Cu3O6+x system.

Go to article

Electrical Properties Of Srbi₂Ta₂O₉ Ferroelectric Thin Films At Low Temperature, Pingxiong Yang, David L. Carroll, John Ballato, Robert W. Schwartz Dec 2002

Electrical Properties Of Srbi₂Ta₂O₉ Ferroelectric Thin Films At Low Temperature, Pingxiong Yang, David L. Carroll, John Ballato, Robert W. Schwartz

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The temperature dependence of electrical properties for SrBi2Ta2O9 thin film capacitors with platinum electrodes (Pt/SBT/Pt) on silicon wafers was studied from 10 to 300 K. with a decrease in temperature from 300 to 200 K, the remanent polarization of the thin films shows about an 11% reduction from its 300 K value; however, it is reduced by about 87% reduction from its 200 K value when the temperature drops from 200 to 100 K. with a decrease to 200 K, the polarization fatigue was significant, and the capacitor shows an approximate 29% reduction in polarization from its initial value following …

Go to article

Sensorless Super-High-Speed Switched Reluctance Generators, Chris S. Edrington, Babek Fahimi, Ray B. Sepe Dec 2002

Sensorless Super-High-Speed Switched Reluctance Generators, Chris S. Edrington, Babek Fahimi, Ray B. Sepe

Electrical and Computer Engineering Faculty Research & Creative Works

Operating at super high speeds emerges as a need in various sectors of industry including military, automotive and home appliances. Generation of electric power at such speeds has the inherent advantage of compactness and elimination of speed adaptation means. Switched Reluctance (SR) drives favor high-speed operation due to their inherent ruggedness and robust structure. In addition, they represent a very long constant power region allowing an efficient operation in a compact form. Moreover, SRM drives can tolerate structural and thermal conditions imposed by the application. Finally, they are inherently fault tolerant due to their modular configuration. To take steps towards …

Go to article

Interactive Learning Tools: Animating Statics, Nancy Hubing, David B. Oglesby, Timothy A. Philpot, Vikas Yellamraju, Richard H. Hall, Ralph E. Flori Dec 2002

Interactive Learning Tools: Animating Statics, Nancy Hubing, David B. Oglesby, Timothy A. Philpot, Vikas Yellamraju, Richard H. Hall, Ralph E. Flori

Business and Information Technology Faculty Research & Creative Works

Computer-Based Modules for Engineering Instruction Must Be Concise, Flexible, Educational and Engaging in Order to Effectively Supplement Traditional Classroom Teaching Tools. a Computer Example that Takes More Time Than a Chalkboard Presentation is Not Likely to Be Useful in Today's Engineering Classroom. Flexible Navigation is Necessary So that the Instructor Can Quickly and Easily Respond to Student Questions. Useful Modules Must Also Improve Problem-Solving Skills or Clarify Troublesome Concepts in Order to Be Considered Worthy of Inclusion in the Limited Class Time Available. Finally, and Perhaps Most Importantly, Effective Computer-Based Modules Must Meet the Challenge of Holding the Student's Attention. …

Go to article

The Evolution And Implications Of The Concentration Profiles Of An Analyte In Porous Adsorbent Particles Packed In A Capillary Electrochromatography Column Operated In The Analytical Mode, B. A. Grimes, Athanasios I. Liapis Dec 2002

The Evolution And Implications Of The Concentration Profiles Of An Analyte In Porous Adsorbent Particles Packed In A Capillary Electrochromatography Column Operated In The Analytical Mode, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this work, a mathematical model is constructed and solved to describe the propagation and dispersion of the mass wave of an analyte in a capillary electrochromatography (CEC) column packed with porous adsorbent particles and operated in the analytical mode. The evolution and dynamic behavior of the isoconcentration contours of the concentration of the analyte in the pores of the particles are presented in order to demonstrate the significant impact that the velocity of the intraparticle electroosmotic flow (EOF) encountered in CEC systems could have in reducing the overall intraparticle mass transfer resistance. It is shown that under both unretained …

Go to article

Dynamic Yield Analysis And Enhancement Of Fpga Reconfigurable Memory Systems, Minsu Choi, Nohpill Park Dec 2002

Dynamic Yield Analysis And Enhancement Of Fpga Reconfigurable Memory Systems, Minsu Choi, Nohpill Park

Electrical and Computer Engineering Faculty Research & Creative Works

This paper addresses the issues of field programmable gate arrays (FPGA) reconfigurable memory systems with faulty physical memory cells and proposes yield measurement techniques. Static yield (i.e., the yield which does not take into account the inherited redundancy utilization for repair) and dynamic yield (i.e., the yield which takes into account the inherited redundancy utilization for repair) of FPGA reconfigurable memory systems and their characteristics are extensively analyzed. Yield enhancement of conventional memory systems relies on additional redundancy, but FPGA reconfigurable memory systems have inherited redundancy and customizability. Thus, they can accommodate numerous target memory configurations, and redundant memory cells, …

Go to article

Method, Apparatus And Article For Microfluidic Control Via Electrowetting, For Chemical, Biochemical And Biological Assays And The Like, James D. Sterling Nov 2002

Method, Apparatus And Article For Microfluidic Control Via Electrowetting, For Chemical, Biochemical And Biological Assays And The Like, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

An active-matrix microfluidic platform employs thin film transistor active ("TFT") matrix liquid crystal display ~ technology to manipulate small samples of fluid for chemical, biochemical, or biological assays without moving parts, for example, using a two-dimensional matrix array of drive electrodes. The active-matrix microfluidic platform may employ existing active matrix 0 addressing schemes and/or commercial "off-the-shelf" animation software to program assay protocols. A feedback subsystem may > determine an actual location of a fluid in the microfluidic structure, and provides location information to for display, for example, on an active-matrix display, and/or to control movement of one or more fluid bodies …

Go to article

Segmented Roll For Casting Metal Strip, James R. Sauer, Ronald J. O'Malley, Robert S. Williams Nov 2002

Segmented Roll For Casting Metal Strip, James R. Sauer, Ronald J. O'Malley, Robert S. Williams

Materials Science and Engineering Faculty Research & Creative Works

Casting molten metal using a segmented roll for casting continuous metal strip. A strip caster (10) for producing a continuous strip (18) includes a tundish for containing a melt and a pair of horizontally disposed water cooled composite casting rolls (84). The casting rolls are juxtaposed relative to one another for forming a pouring basin (16) for receiving molten metal. The composite rolls are formed from a plurality of annular segments (45). Each segment preferably includes at least a pair of coolant openings (34) and means for aligning the coolant openings, such as a pair of alignment openings (26). The …

Go to article

Microstructure-Electrical Conductivity Relationships In Nanocrystalline Ceria Thin Films, Toshio Suzuki, Igor Kosacki, Harlan U. Anderson Nov 2002

Microstructure-Electrical Conductivity Relationships In Nanocrystalline Ceria Thin Films, Toshio Suzuki, Igor Kosacki, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

A study of nanocrystalline oxide thin film processing and influence of microstructure on the electrical properties of nanocrystalline Gd3+-doped CeO2 thin films was reported. Nanocrystalline films on sapphire substrate were prepared using a polymeric precursor spin coating technique. The grain size of these films depends upon the annealing temperatures and the dopant content, where higher content of dopant realized smaller grain size. The electrical conductivity of nanocrystalline Gd3+-doped CeO2 thin films was studied as a function of temperature and oxygen activity and correlated with the grain size. The results show that the electronic conductivity …

Go to article

Numerical Simulation Of Partial Discharge Propagation In Cable Joints Using The Finite Difference Time Domain Method, David Pommerenke, R. Jobava, R. Heinrich Nov 2002

Numerical Simulation Of Partial Discharge Propagation In Cable Joints Using The Finite Difference Time Domain Method, David Pommerenke, R. Jobava, R. Heinrich

Electrical and Computer Engineering Faculty Research & Creative Works

In this second of a series of three papers, the authors investigate partial discharge (PD) detection and propagation in cable joints. The complex nature of cable joints leads to errors when PD analysis is carried out using conventional equivalent circuits. The authors use the finite difference time domain method to determine the transient electromagnetic fields caused by simulated PD in model cable joints.

Go to article

Strengthening And Load Testing Of Three Bridges In Boone County, Missouri, S. Schiebel, R. Parretti, Antonio Nanni, M. Huck Nov 2002

Strengthening And Load Testing Of Three Bridges In Boone County, Missouri, S. Schiebel, R. Parretti, Antonio Nanni, M. Huck

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Three bridges in Boone County, Missouri - Brown School Road, Coats Lane, and Creasy Springs Bridges - were selected for strengthening with carbon-fiber-reinforced polymer laminates in both shear and flexure. The objective of the rehabilitation program was to remove the 15-ton load posting that had been imposed on each of the bridges. To verify the results of the upgrade, load tests were performed before and after strengthening on two of the bridges - Brown School Road and Coats Lane Bridges. This paper presents the procedures followed in the design, installation, and load testing of the bridges. A recommendation regarding the …

Go to article

Strengthening Of Short Shear Span Reinforced Concrete T Joists With Fiber-Reinforced Plasic Composites, Francesco Micelli, Raghu H. Annaiah, Antonio Nanni Nov 2002

Strengthening Of Short Shear Span Reinforced Concrete T Joists With Fiber-Reinforced Plasic Composites, Francesco Micelli, Raghu H. Annaiah, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this work, the results of an experimental study conducted in a 1964-vintage building are presented. Twelve reinforced concrete (RC) T-joists strengthened with fiber-reinforced plastic (FRP) composites were loaded until failure in a short shear span configuration. Different strengthening schemes, including different FRP materials and a new FRP anchorage system, were adopted in order to compare the performance of the different installations. Carbon FRP and aramid FRP sheets in an epoxy matrix were bonded to the RC joists using the wet layup technique. All of the joists were loaded close to one end support and showed similar cracking patterns at …

Go to article

Review Of Stabilization Of Clays And Expansive Soils In Pavements And Lightly Loaded Structures - History, Practice, And Future, Thomas M. Petry, Dallas N. Little Nov 2002

Review Of Stabilization Of Clays And Expansive Soils In Pavements And Lightly Loaded Structures - History, Practice, And Future, Thomas M. Petry, Dallas N. Little

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Expansive clay soils-those that change significantly in volume with changes in water content-are the cause of distortions to structures that cost taxpayers several billion dollars annually in the United States. Much has been learned about their behavior over the past 60 years, and relatively successful methods have been developed to modify and stabilize them. This paper reviews some of the key advances developed over the past 60 years in improving our understanding of the nature and methods of modifying and stabilizing expansive clay soils. The state of the practice in stabilization is presented, and practical and research needs to help …

Go to article

Magnetic Order In Yba2⁢Cu3⁢O6+X Superconductors, Herbert A. Mook, Pengcheng Dai, Stephen M. Hayden, Arno Hiess, Jw Lynn, S-H Lee, Fatih Dogan Oct 2002

Magnetic Order In Yba2⁢Cu3⁢O6+X Superconductors, Herbert A. Mook, Pengcheng Dai, Stephen M. Hayden, Arno Hiess, Jw Lynn, S-H Lee, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Polarized and unpolarized neutron diffraction has been used to search for magnetic order in YBa2⁢Cu3⁢O6+x superconductors. Most of the measurements were made on a high-quality crystal of YBa2⁢Cu3⁢O6.6. It is shown that this crystal has highly ordered ortho-II chain order, and a sharp superconducting transition. Inelastic scattering measurements display a very clean spin-gap and pseudo gap with any intensity at 10 meV being 50 times smaller than the resonance intensity. The crystal shows a complicated magnetic order that appears to have three components. A magnetic phase is found at …

Go to article

Structural Behaviour Of Self-Piercing Riveted Connections In Steel Framed Housing, Stephen Moss, Mahen Mahendran Oct 2002

Structural Behaviour Of Self-Piercing Riveted Connections In Steel Framed Housing, Stephen Moss, Mahen Mahendran

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

Self-piercing riveting involves the joining of two or more plates by using a rivet to pierce and clinch in a single operation. There is a distinct lack of information regarding the use of self-piercing riveted connections in cold-formed steel frames. Experimental research is being undertaken to investigate the structural behaviour of self-piercing riveted connections used in steel framed housing. To date, testing has been carried out on 0.75 mm to 1.15 mm G300 steels to determine the primary failure modes for self-piercing riveted connections and also to assess the applicability of standard single point lap shear tests to actual house …

Go to article

Seismic Performance Of Wall-Stud Shear Walls, Ludovic A. Fulop, Dan Dubina Oct 2002

Seismic Performance Of Wall-Stud Shear Walls, Ludovic A. Fulop, Dan Dubina

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

The ever-increasing need for housing generated the search for new and innovative building methods to increase speed, efficiency and enhance quality, one direction being the use of light steel profiles as load bearing elements and different materials for cladding. Wind and seismic behavior of these structures is influenced by the hysteretic characteristics of the shear wall panels. In this paper a review of actual research in the field and results of a full-scale shear test program on wall panels are presented. Based on tests, a numerical equivalent model for hysteretic behavior of wall panels working in shear was built to …

Go to article

Stiffened Elements With Multiple Intermediate Stiffeners And Edge Stiffened Elements With Intermediate Stiffeners, Benjamin W. Schafer Oct 2002

Stiffened Elements With Multiple Intermediate Stiffeners And Edge Stiffened Elements With Intermediate Stiffeners, Benjamin W. Schafer

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

Section B5 of the AISI Specification, covering stiffened elements with multiple intermediate stiffeners and edge stiffened elements with intermediate stiffeners, has been entirely replaced in the latest edition of the Cold-Formed Steel Specification (NAS 2001). The new design rules are based primarily on the work of Schafer and Pekoz (1998); however, subsequent to that work and prior to adoption by AISI, additional work was also completed. For elements with multiple intermediate stiffeners consideration of weblflange interaction was added. The resulting expressions are shown to agree well with both experimental and numerical data. New provisions for edge stiffened elements with intermediate …

Go to article

First Prev Next Last