Flexural Strength of Continuous-Span Z-Purlins with Paired Torsion Braces using the Direct Strength Method

A procedure is presented to calculate the local and distortional flexural buckling strength of continuous span purlins with paired torsion braces using the Direct Strength Method. Displacement compatibility is utilized to determine the forces interacting between the purlin, the flexible diaphragm and the torsion braces. The biaxial bending and torsion effects caused by this interaction are superimposed, and the actual distribution of stresses within the cross section are calculated at critical locations along the span. With this distribution of stresses, a finite strip buckling analysis is performed to determine the local and distortional buckling strength. In current design practice, results from a simple span Base Test are extrapolated to multi-span systems using a constrained bending stress distribution. In previous work, a variation of the presented method was compared to simple span base test results with good correlation. In this paper, the simple span stresses are compared to the stresses of continuous span systems. Significant, although typically conservative differences in the stress distributions and, as a result the predicted flexural strength, are observed in the comparison between simple span and multi-span systems. Additionally, significant changes in the distribution of stresses are observed as roof slope effects are considered. Increases in the flexural strength with increasing roof slope are reported and compared to the strength predicted by the current base test method

A Monte Carlo Investigation of Nonparametric One-Way Multivariate Analysis of Variance (Rank Transformation, Normal Scores, Manova Test, Robustness).

This research is concerned with the rank and normal score transform procedures in which the usual parametric procedures are applied to the ranks of the data and the normal scores based on the ranks instead of the original data in one-way multvariate analysis of variance (MANOVA). Four MANOVA test criteria were compared in terms of the parametric, rank and normal score procedures: (1) Roy\u27s largest root, R, (2) Lawley-Hotelling trace, T, (3) Wilks\u27s likelihood ratio, W and (4) Bartlett-Nanda-Pillai trace, V. A Monte Carlo investigation was designed to compare the procedures in terms of control of Type I error and power. Four factors were involved in the Type I error study for each of the four MANOVA criteria: the number of variates (p = 2, 3, 4, 5), the number of groups (k = 3, 4, 5), the equal group size (Ns = 5, 10, 20, 40) and the five distributions (normal, lognormal, uniform, Cauchy, exponential). Each of the variates in a sample was generated independently from a parent distribution. In the power study, p = 3, k = 4, Ns = 10 and 20 were selected. Five levels of location parameter for group 1 were used. The major results drawn from the investigation are as follows. The rank and normal score procedures compete well with the parametric procedure for the normal distribution and outperform it in other cases. The overall evaluation indicates that the normal scores are preferable in terms of Type I error control, closely followed by the rank procedure. However, the overall power evaluation favors the rank procedure, followed by normal scores. The nonparametric procedures are rather robust and consistent throughout the considered distributions and four MANOVA test criteria. Even though normal scores appear to be slightly better than the ranks in terms of Type I error control, the advantage of the normal scores over the ranks is not significant enough to offset the complicated nature of the normal score transform. Consequently, the use of the rank transform can be recommended when the data do not meet the normality assumption

A Multicultural/Multimodal/Multisystems (MULTI-CMS) Approach for Immigrant Families: Structural Equation Modeling of Adolescent Perception of Conflict with Parents

The University Archives has determined that this item is of continuing value to OSU's history.Moon, Sung Seek, Ph.D., University of Georgia, Athens, Georgia - "A Multicultural/Multimodal/Multisystems Approach for Immigrant Families: Structural Equation Modeling of Adolescent Perceptions of Conflict with Parents"The Ohio State University College of Social Wor

Removal of Copper Using Microwave Incinerated Rice Husk Ash (MIRHA) In Continuous Flow Activated Sludge System

Copper is being widely used in a variety of textile, steel and dyes industries. Wastewater contains copper and organic matters need to be treated prior to discharge to the environment, else it could pose adverse health effects to human. Current heavy metals removal methods, such as adsorption by activated carbon, ion exchange, reverse osmosis, chemical precipitation and nanofiltration, are expensive, unable to completely remove heavy metals and involve high energy and chemical consumption. The purpose of this research is to propose the removal of copper and organic matters using biological treatment system, dosed with Microwave Incinerated Rice husk Ash (MIRRA) adsorbent. The objectives are to study if MIRRA is capable to delay the toxicity effect of copper and the feasibility of using MIRRA as low cost copper adsorbent in activated sludge system. The research is carried out by conducting experiments using 2 scaled down biological reactor. Medium strength wastewater dosed with copper at dosage of 0.5 mg/L, 1.0 mg/L, 2.0 mg!L, 5.0 mg/L and 10.0 mg/L is used as influent. The reactor is run in Extended Aeration Activated Sludge mode. The result shows that MIRRA adsorbent has improved the overall performance of biological treatment system in term of organic matters (TCOD & BOD) removal, copper removal and improved the growth of microbes in the activated sludge system. With MIRRA adsorbent and gradual acclimatization, microbes are capable to withstand copper concentration up to 5.0 mg/L, as compared to 2.0 mg/L without MIRRA. Besides, it is also concluded that acclimatization is capable to improve microbes' tolerance toward copper toxicity from 1.0 mg/L to 2.0 mg!L in Extended Aeration Activated Sludge system. In short, Extended Aeration Activated Sludge system dosed with MIRRA adsorbent is a new approach toward removal of copper and organic matters in wastewater that contains copper concentration up to 5. 0 mg/L

An Updated Analytical Method for Predicting the Bracing Behavior of Z-Purlin Supported Standing Seam Diaphragm Systems

Roof systems utilizing Z-purlins as a secondary member supporting a standing seam panel system are used extensively by the metal building industry. The Z-purlins rely on the diaphragm action in the standing seam panel system to provide lateral support and transfer forces to anchorages. The behavior of the standing seam system is highly nonlinear making prediction of the interaction between the Z-purlin and the standing seam system difficult. To better understand the behavior of the interaction between the purlins and the panel system, a series of non-linear shell finite element models were developed based on the test results of simple span systems. These models capture the non-linear flexibility of the connection between the purlin and the panel and show good correlation to the tests. Based on the results of the finite element models, an analytical method to predict the forces interacting between the purlin and the sheathing as well as the resulting diaphragm deformation was developed. This analytical method provides a foundation for additional analytical methodologies to predict the strength and stability of Z-purlin and standing seam panel systems

Improvements to the Prediction of Brace Forces in Z-Purlin Roof Systems with Support + Third Point Bracing

The Component Stiffness Method is a displacement compatibility method used to analyze C- and Z- section supported roof systems. The method provides a detailed analysis of the flexibility in the roof system and the distribution of forces as they flow out of the system. Parametric studies of the equations for typical roof systems have shown that by ignoring the flexibility of some of the components, the method can be simplified with little impact on the anchorage forces calculated. Changes have also been made to the way in which cross section deformations are incorporated into the method. This paper focuses on the changes to the supports + third point bracing configuration and compares the bracing force predicted by the revised equation to the existing equations. The prediction equations are applied to a series of purlins and sheathing systems to represent the ends of the spectrum and the results are compared