Wichita State University

About: Wichita State University is a education organization based out in Wichita, Kansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 4988 authors who have published 9563 publications receiving 253824 citations. The organization is also known as: WSU & Fairmount College.

Expressive Responses to News Stories About Extremist Groups: A Framing Experiment

Abstract: With the tension between national security and civil liberties as a backdrop, this study examines responses to news coverage of activist groups. This 2 3 2e xperiment presented participants with news stories about government efforts to restrict the civil liberties of an ‘‘extremist’’ individual or group (news frame) advocating for a cause supported or opposed by the respondent (cause predisposition). Willingness to take expressive action was greatest for individual-framed stories about a cause opposed by the respondent and for groupframed stories about a cause supported by the respondent. We contend that when reporters frame stories about extremist groups around individuals, fewer people will speak out in favor of causes they agree with and more will rally against causes they oppose.

A Kriging Model for Dynamics of Mechanical Systems With Revolute Joint Clearances

Abstract: Over the past two decades, extensive work has been conducted on the dynamic effect of joint clearances in multibody mechanical systems. In contrast, little work has been devoted to optimizing the performance of these systems. In this study, the analysis of revolute joint clearance is formulated in terms of a Hertzian-based contact force model. For illustration, the classical slider-crank mechanism with a revolute clearance joint at the piston pin is presented and a simulation model is developed using the analysis/design software MSC.ADAMS. The clearance is modeled as a pin-in-a-hole surface-to-surface dry contact, with an appropriate contact force model between the joint and bearing surfaces. Different simulations are performed to demonstrate the influence of the joint clearance size and the input crank speed on the dynamic behavior of the system with the joint clearance. In the modeling and simulation of the experimental setup and in the followed parametric study with a slightly revised system, both the Hertzian normal contact force model and a Coulomb-type friction force model were utilized. The kinetic coefficient of friction was chosen as constant throughout the study. An innovative design-of-experiment (DOE)-based method for optimizing the performance of a mechanical system with the revolute joint clearance for different ranges of design parameters is then proposed. Based on the simulation model results from sample points, which are selected by a Latin hypercube sampling (LHS) method, a polynomial function Kriging meta-model is established instead of the actual simulation model. The reason for the development and use of the meta-model is to bypass computationally intensive simulations of a computer model for different design parameter values in place of a more efficient and cost-effective mathematical model. Finally, numerical results obtained from two application examples with different design parameters, including the joint clearance size, crank speed, and contact stiffness, are presented for the further analysis of the dynamics of the revolute clearance joint in a mechanical system. This allows for predicting the influence of design parameter changes, in order to minimize contact forces, accelerations, and power requirements due to the existence of joint clearance.

Gas-Phase Complexes Containing the Uranyl Ion and Acetone

Abstract: We report here that electrospray ionization (ESI) of uranyl nitrate dissolved in a mixture of H 2 O and acetone causes the formation of doubly charged, gas-phase complexes containing UO 2 2 + "solvated" by neutral ligands.Using mild conditions, the dominant species observed in the ESI mass spectrum contained the uranyl ion coordinated by five acetone ligands, consistent with proposed most-stable structures in the solution phase. However, chemical mass shift data, ion peak shapes, and a plot of fractional ion abundance versus ion desolvation temperature suggest that in the gas phase, and under the ion-trapping and ejection conditions imposed, complexes with five equatorial acetone ligands are less stable than those with four. Multiple-stage tandem mass spectrometry showed that uranyl-acetone complexes dissociate via the elimination of acetone ligands and through pathways that involve reactive collisions with adventitious H 2 O in the ion trap. At no point was complete removal of ligands to generate the UO 2 2 + ion achieved. ESI was also used to generate complex ions of similar composition and ligand number but different charge state for an investigation of the influence of complex charge on the tendency to add ligands by gas-phase association reactions. We found that the addition of a fifth acetone molecule to complexes initially containing four equatorial ligands is more facile for the doubly charged species. The singly charged complex shows a significant back-reaction to eliminate the fifth ligand, suggesting an intrinsic difference in the preferred coordination number for the U(VI) and U(V) complexes in the gas phase.