Digital Commons Network^™

Experimental Study Of Longitudinally Stiffened Web Channels Subjected Predominantly To Shear, Luciano A. Bruneau, Cao Hung Pham, Gregory J. Hancock

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

The Direct Strength Method (DSM) of design of cold-formed sections has recently been extended in the North American Specification for Cold-Formed Steel Structural Members-NAS S100:2012 to include shear. The two new features of the DSM rules for shear researched are the effect of full-section shear buckling as opposed to web-only shear buckling and Tension Field Action (TFA). The prequalified sections in the rules include sections with flat webs and webs with small intermediate longitudinal stiffeners. In order to extend the range to larger intermediate stiffeners as occurs in practice, a series of fourteen shear tests have been performed at the …

Numerical Studies Of Collapse Behaviour Of Multi-Span Beams With Cold Formed Sigma Sections, F. L. Wang, J. Yang, J. Lim

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

Multi-span cold-formed steel beams are widely used for roof purlin and cladding rails due to their high strength to weight ratio and ease of installation on site. There are a wide variety of cross-sectional shapes e.g. C, Z, top hat and sigma sections. A sigma section possesses several advantages such as high cross-sectional resistances and large torsional rigidities compared with standard Z or C sections.

Traditional design methods for cold-formed multi-span steel beams have been based on elastic theory, such as the Effective Width Method (EWM) and the Direct Strength Method (DSM). Both methods ignore the effect of redistribution of …

Development Of A New Beam-Column Design Method For Cold-Formed Steel Lipped Channel Members, Shahabeddin Torabian, Baofeng Zheng, Benjamin W. Schafer

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

The structural strength of cold-formed steel lipped channels under combined axial force and biaxial bending moments has been predicted by geometric and material nonlinear collapse analyses performed in ABAQUS and compared to both current, and a newly proposed, beam-column design method. The ABAQUS analyses utilizes a validated modeling protocol calibrated against previous testing by the authors, and including residual stresses and strains, and geometric imperfections; as well as, appropriate cross-section dimensions, member length, and boundary conditions. A total of 75 different lipped channel cross-sections have been selected and the capacity of the beam-column member has been examined under 127 combinations …

Experimental Investigation On Ultimate Capacity Of Eccentrically-Compressed Cold-Formed Beam-Columns With Lipped Channel Sections, Yuanqi Li, Yinglei Li, Yanyong Song

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

This paper is mainly concerned with the in-plane behavior of eccentrically-compressed cold-formed steel beam-columns with lipped channel sections. The tested members are classified into three series by loading types including: axial compression and major axis bending (X), axial compression and minor axis bending (lips in tension, Y1), and axial compression and minor axis bending (lips in compression, Y2). A numerical model is developed and verified by the experimental results. Then the elastic local buckling loads are discussed based on test results, numerical analysis, and design methods. The comparison between test strength and nominal strength obtained by AISI specification indicates that …

Going From Microbial Ecology To Genome Data And Back: Studies On A Haloalkaliphilic Bacterium Isolated From Soap Lake, Washington State, Melanie R. Mormile

Biological Sciences Faculty Research & Creative Works

Soap Lake is a meromictic, alkaline (∼pH 9.8) and saline (∼14-140 g liter^-1) lake located in the semiarid area of eastern Washington State. Of note is the length of time it has been meromictic (at least 2000 years) and the extremely high sulfide level (∼140 mM) in its monimolimnion. As expected, the microbial ecology of this lake is greatly influenced by these conditions. A bacterium, Halanaerobium hydrogeniformans, was isolated from the mixolimnion region of this lake. Halanaerobium hydrogeniformans is a haloalkaliphilic bacterium capable of forming hydrogen from 5- and 6-carbon sugars derived from hemicellulose and cellulose. Due …

System Function Adoption Of An Open Source Digital Repository System: A Global View, Hsin-Liang Chen, Yin Zhang

University Libraries Faculty Research & Creative Works

This poster reports a project that examines the adoption of system functions of an open source digital repository, DSpace. It also identifies the factors which have influenced the functions' adoption. The data were collected from DSpace user registry from September 2013 to March 2014. A total of 545 repositories in the registry contained system function customizations, representing 533 unique institutions from 95 countries. The preliminary findings indicate that 10 of the 32 available system functions are adopted by over 10% of its members; the majority of repositories are from academia; academic repositories also offer most system functions; and the U.S. …

Fano Resonances Realized In Thz Metamaterials Composed Of Continuous Metallic Wires And Split Ring Resonators, Z. Li, S. Cakmakyapan, B. Butun, C. Daskalaki, S. Tzortzakis, Xiaodong Yang, E. Ozbay

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Route To Optimal Generation Of Soft X-Ray High Harmonics With Synthesized Two-Color Laser Pulses, Cheng Jin, Guoli Wang, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

High harmonics extending to X-rays have been generated from gases by intense lasers. To establish these coherent broadband radiations as an all-purpose tabletop light source for general applications in science and technology, new methods are needed to overcome the present low conversion efficiencies. Here we show that the conversion efficiency may be drastically increased with an optimized two-color pulse. By employing an optimally synthesized 2-µm mid-infrared laser and a small amount of its third harmonic, we show that harmonic yields from sub- to few-keV energy can be increased typically by ten-fold over the optimized single-color one. By combining with favorable …

Fully Differential Study Of Interference Effects In The Ionization Of H₂ By Proton Impact, Sachin D. Sharma, T. P. Arthanayaka, Ahmad Hasan, B. R. Lamichhane, J. Remolina, Adolph P. Smith, Michael Schulz

Physics Faculty Research & Creative Works

We have measured fully differential cross sections for ionization of H₂ by 75-keV proton impact. The coherence length of the projectile beam was varied by changing the distance between a collimating slit and the target. By comparing the cross sections measured for large and small coherence lengths pronounced interference effects could be identified in the data. A surprising result is that the phase angle in the interference term is primarily determined by the momentum transfer and only to a lesser extent by the recoil-ion momentum.

Study Of Energy Recovery And Power Generation From Alternative Energy Source, Abdulhakim Amer A. Agll, Yousif M. Hamad, Tarek A. Hamad, John W. Sheffield

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The energy requirement pattern of world is growing up and developing technology. The available sources, while exhausting and not friendly to the environment, are highly used. Looking at partial supply and different options of environment problems associated with usage, renewable energy sources are getting attention. MSW (Municipal solid waste) composition data had been collected from 1997 to 2009, in Benghazi Libya, to evaluate the waste enthalpy. An incinerator with capacity of 47,250 kg/h was confirmed to burn all the quantity of waste generated by the city through the next 15 years. Initial study was performed to investigate energy flow and …

Multimessenger Search For Sources Of Gravitational Waves And High-Energy Neutrinos: Initial Results For Ligo-Virgo And Icecube, M. G. Aartsen, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010 run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of gravitational-wave emission energy of 10^-2M⊙c² at ∼150Hz with …

Predicting Solar Irradiance Using Time Series Neural Networks, Ahmad Alzahrani, Jonathan W. Kimball, Cihan H. Dagli

Electrical and Computer Engineering Faculty Research & Creative Works

Increasing the accuracy of prediction improves the performance of photovoltaic systems and alleviates the effects of intermittence on the systems stability. A Nonlinear Autoregressive Network with Exogenous Inputs (NARX) approach was applied to the Vichy-Rolla National Airport's photovoltaic station. The proposed model uses several inputs (e.g. time, day of the year, sky cover, pressure, and wind speed) to predict hourly solar irradiance. Data obtained from the National Solar Radiation Database (NSRDB) was used to conduct simulation experiments. These simulations validate the use of the proposed model for short-term predictions. Results show that the NARX neural network notably outperformed the other …

Modeling Of Thermal And Mechanical Behavior Of Zrb₂-Sic Ceramic After High Temperature Oxidation, Jun Wei, Lokeswarappa R. Dharani, K. Chandrashekhara, Greg Hilmas, William Fahrenholtz

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Interaction Of Bn-Zro2-Sic Ceramics With Inclusions In Si-Killed Steel, Abhishek Kumar, Vivek Thapliyal, Jeffrey D. Smith

Materials Science and Engineering Faculty Research & Creative Works

Boron nitride (BN)-based ceramics are often used as containment refractory in thin-strip steel production. The interaction of this material (BN-ZrO₂-SiC: -MYCROSINT® SO43) was studied using a steel-inclusion system in a laboratory setup. Isothermal interaction tests were performed to evaluate the interaction of inclusions with this refractory. It was determined that corrosion of the BN refractory occurs through a dissolution mechanism and it was more severe in contact with steel compared to slag. A thermodynamic model was developed using FactSage to study the change in liquid steel/slag composition with refractory interaction. Thermodynamic predictions were in agreement with the experimental …

Conducting Scaffolds For Liver Tissue Engineering, Armin Tahmasbi Rad, Naushad Ali, Hari Shankar R. Kotturi, Mostafa Yazdimamaghani, Jim Smay, Daryoosh Vashaee, Lobat Tayebi

Chemical and Biochemical Engineering Faculty Research & Creative Works

It is known that there is a correlation between a cell membrane potential and the proliferation of the cell. The high proliferation capacity of liver cells can also be attributed to its specific cell membrane potential as liver cell is recognized as one of the most depolarized of all differentiated cells. We hypothesized that this phenomenon can be emphasized by growing liver cells in conducting scaffolds that can increase the electrical communication among the cells. In this article, using tissue engineering techniques, we grew hepatocyte cells in scaffolds with various compositions. It was found that the scaffolds containing conducting polymer …

Large-Scale Mechanical Buckle Fold Development And The Initiation Of Tensile Fractures, Andreas Eckert, Peter Connolly, Xiaolong Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Tensile failure associated with buckle folding is commonly associated to the distribution of outer arc extension but has also been observed on fold limbs. This study investigates whether tensile stresses and associated failure can be explained by the process of buckling under realistic in situ stress conditions. A 2-D plane strain finite element modeling approach is used to study single-layer buckle folds with a Maxwell viscoelastic rheology. A variety of material parameters are considered and their influence on the initiation of tensile stresses during the various stages of deformation is analyzed. It is concluded that the buckling process determines the …

Localization Of Near-Field Radio Controlled Unintended Emitting Sources In The Presence Of Multipath Fading, Nurbanu Guzey, Hao Xu, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Localization of near-field unintended emitting radio controlled (RC) devices under a multipath environment is considered in this paper using a uniform linear array (ULA). Since received signals are dependent on both angle of arrival (AoA) and distance from the RC devices to the ULA in the near-field scenario, traditional localization schemes based on received signal strength indicator, time difference in arrival, which only estimate either AoA or distance, are unsuitable. Therefore, a novel smooth 2-D multiple signal classification (MUSIC) near-field localization scheme is developed to locate RC devices under a multipath environment with a possible location error of 0.5 m. …

Runtime Self-Calibrated Temperature-Stress Cosensor For 3-D Integrated Circuits, Chun Zhang, Dian Ma, Changzhi Li, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

On-chip temperature and stress sensors are important for runtime system management techniques tackling thermomechanical reliability issues in 3-D integrated circuits (ICs). However, traditional temperature and stress sensor designs require large calibration overhead to improve accuracy, which incurs significant cost for massive production. To address the challenge, in this paper, we propose a novel temperature-stress cosensor design for 3-D ICs. By exploring the inherent reciprocity of temperature and stress mechanisms, it achieves runtime self-calibration such that no dedicated calibration effort is needed. Simulation results show that the cosensor achieves 0.26 C and 0.43 MPa accuracy on average in temperature and stress …

Solid Waste As Renewable Source Of Energy: Current And Future Possibility In Libya, Tarek A. Hamad, Abdulhakim A. Agll, Yousif M. Hamad, John W. Sheffield

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Solid waste holds the greatest potential as biomass source in Libya. The rapid expansion of industry has led to increased urbanization and growing population. These factors have dramatically increased the amount of MSW (municipal solid waste) generated in Libya. However, issues related to environmentally sound MSW management - including waste decrease and clearance - have not been addressed sufficiently. This study presents an overview on solid waste that can be used as a source of bioenergy in Libya including MSW, ISW (industrial solid waste), and HSW (health care wastes) as biomass sources. The management of solid waste and valorization is …

Manufacturing Of Transparent Composites Using Vacuum Infusion Process, V. G.K. Menta, R. R. Vuppalapati, K. Chandrashekhara, Thomas P. Schuman

Chemistry Faculty Research & Creative Works

A novel optically transparent glass fiber reinforced polymer matrix composite has been developed by infusing a clear epoxy resin system of matching refractive index into a conventional E-glass fabric preform. Transparent composites are manufactured using a low cost, environmentally friendly vacuum infusion process. Physical and mechanical tests have been conducted. Transparent composites manufactured using the modified vacuum infusion process had a fiber volume fraction of 40%. Tensile strength and tensile modulus of these composites were 374.9 MPa and 31.74 GPa respectively. The results indicate that the transparent composites possess good physical and mechanical properties. These transparent composites form a good …

Crystallographic Changes In Lead Zirconate Titanate Due To Neutron Irradiation, Alexandra Henriques, Joseph T. Graham, Sheldon Landsberger, Jon F. Ihlefeld, Geoff L. Brennecka, Donald W. Brown, Jennifer S. Forrester, Jacob L. Jones

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Piezoelectric and ferroelectric materials are useful as the active element in non-destructive monitoring devices for high-radiation areas. Here, crystallographic structural refinement (i.e., the Rietveld method) is used to quantify the type and extent of structural changes in PbZr_0.5Ti_0.5O₃ after exposure to a 1 MeV equivalent neutron fluence of 1.7x10¹⁵ neutrons/cm². The results showa measurable decrease in the occupancy of Pb and O due to irradiation, with O vacancies in the tetragonal phase being created preferentially on one of the two O sites. The results demonstrate a method by which the …

The Impact Of Regulation Fd On The Information Environment: Evidence From The Stock Market Response To Stock Split Announcements, Lili Eng, Joohyung Ha, Sandeep Nabar

Business and Information Technology Faculty Research & Creative Works

This paper examines the information environment effects of regulation fair disclosure (Reg FD). We investigate the stock market response to stock splits in the pre- and post-regulation periods. We find that abnormal returns around split announcement are positive in both periods, but the magnitude of the returns is smaller in the post-FD period relative to the pre-FD period. The difference between the pre- and post-FD period abnormal returns persists even after we control for factors that may affect split announcement returns. We also find that the magnitude of the association between announcement returns, and the unexpected portion of the split …

Calderón Preconditioned Pmchwt Equations For Analyzing Penetrable Objects In Layered Medium, Yongpin P. Chen, Lijun Jiang, Sheng Sun, Weng Cho Chew, Jun Hu

Electrical and Computer Engineering Faculty Research & Creative Works

We study Calderón preconditioners for analyzing electromagnetic scattering by penetrable objects in a layered medium. To account for the scattering effects of the multilayered background, the layered medium Green's function is adopted in the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) method. However, similar to the free-space case, the spectrum of the resulting equation is undesirable. This leads to a slow convergence of an iterative solver, especially when the geometry is densely meshed. To improve the convergence, a highly effective preconditioner is proposed. Different from its free-space counterpart, the preconditioning operator is constructed based on the Calderón identities for inhomogeneous medium. To reduce the relatively …

The Missouri Miner, October 30, 2014

The Missouri Miner Newspaper

No abstract provided.

Faculty Senate Minutes October 23, 2014, Missouri University Of Science And Technology Faculty Senate

Minutes & Agendas

No abstract provided.

The Missouri Miner, October 23, 2014

The Missouri Miner Newspaper

No abstract provided.

An Adaptive Hierarchical Sparse Grid Collocation Method For Stochastic Scattering Systems Analysis, Ping Li, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

To quantify the impacts of random inputs on hybrid electromagnetics (EM)-circuit systems or EM scattering from objects, an adaptive hierarchical sparse grid collocation (ASGC) algorithm combined with discontinuous Galerkin time-domain (DGTD) method is presented in this work. As a stochastic polynomial chaos modality, the ASGC method approximates the interested stochastic observables using interpolation functions over a set of collocation points. Instead of employing a full-tensor product sense, the collocation points in ASGC method are hierarchically marched with interpolation level based on Smolyak's algorithm. To further reduce the collocation points, the hierarchical surplus is used as the error indicator for each …

Integral Equation Domain Decomposition Method For Low Frequency Scattering, Circuits, And Casimir Force Calculations, P. R. Atkins, Z. H. Ma, L. E. Sun, M. K. Li, L. (Lijun) J. Jiang, M. S. Tong, Q. I. Dai, W. C. Chew

Electrical and Computer Engineering Faculty Research & Creative Works

A broadband integral-equation-based domain decomposition method (DDM) using augmented equivalence principle algorithm (A-EPA) is introduced for solving large scale electromagnetic scattering, circuits, and Casimir force problems. The root cause of the low frequency breakdown problem of EPA algorithm without augmentation technique is analyzed. Numerical examples validate the method for various applications in scattering, circuits, and Casimir force calculations.

Beam-Switchable Magneto-Electric Antenna Array Based On Composite Right/Left-Handed (Crlh) Structures, Shulabh Gupta, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The beam-switching characteristics of Magneto-Electric (ME) dipole antenna array is presented based on differentially exciting the two ports of the array with different polarities. The proposed principle is demonstrated using full-wave simulations that the depending on the polarity of the two excitations, either a magnetic-dipole or an electric-dipole radiation can be selectively achieved.

Generalized Natural Mode Expansion For Arbitrary Electromagnetic Fields, Q. I. Dai, W. C. Chew, L. (Lijun) J. Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A generalized natural mode expansion theory for investigating arbitrary electromagnetic fields is presented. When an inhomogeneity is bounded with impenetrable boundaries, the field excited by arbitrary sources is expanded with a complete set of eigenmodes, which are classified into trapped modes and exterior modes. As the boundaries tend to infinity, trapped modes remain unchanged, while exterior modes form a continuum. In numerical studies, unbounded systems can be emulated by placing perfectly matched layers (PMLs) at finite extent. Simulation shows that only a few natural modes are prominent in expanding the excited field in a properly functioning device. Such a reduced …