Vibration analysis of a tyre model using the wave finite element method

The vibration of a tyre is predicted using the wave finite element (WFE) method. The material properties are considered to be frequency dependent. The WFE method starts from a conventional finite element (FE) model of only a short section of a structure, which is uniform in one direction. Existing element libraries can be fully utilised and the size of the FE model can be very small. Free wave propagation characteristics are extracted from the dynamic stiffness matrix of the FE model. The forced response is calculated using the wave approach. An approach for determining the amplitudes of the directly excited wave is proposed to reduce numerical difficulties. The method is applied to a tyre FE model formed using ANSYS. The material properties of rubber are considered to be frequency dependent. The free wave propagation is shown including nearfield waves. The predicted forced response is compared with experimental data. Good agreement can be seen on the whole

The Tribune’s turbulent times

The Sunday Tribune’s 30-year-story starts with Hibernia’s demise, as an attempt to continue by other means that magazine’s dissenting journalism. Set up by an unlikely partnership of John Mulcahy, proprietor-editor of Hibernia, and Hugh McLaughlin, commercial magazine publisher and Sunday World co-founder, the Sunday Tribune went through several distinct phases in its three decades: 1980- 82, under the control of McLaughlin, with various associates; 1983-94, under the editorship and partial control of Vincent Browne, with changing investment partners, finally Independent Newspapers; 1994-2011, under the effective control of Independent Newspapers, with a succession of four editors. This chapter concentrates on the first two phases, from the founding years through Vincent Browne’s editorship. In these 13 years, the Tribune sought to maintain a structure and perspective that was independent and distinct within the mass-market media of the time. We review several key features of the Sunday Tribune of that period, and present a portrait of a newspaper that has a particular place in the history of Irish journalism and newspaper publishing. But we also describe the pervasive uncertainty about the Tribune’s commercial potential and even its survival, as investors and senior executives came and went frequently, with unsettling effects on the continuing production of the newspaper

Application of High-precision Timing Systems to Distributed Survey Systems

In any hydrographic survey system that consists of more than one computer, one of the most difficult integration problems is to ensure that all components maintain a coherent sense of time. Since virtually all modern survey systems are of this type, timekeeping and synchronized timestamping of data as it is created is of significant concern. This paper describes a method for resolving this problem based on the IEEE 1588 Precise Time Protocol (PTP) implemented by hardware devices, layered with some custom software called the Software Grandmaster (SWGM) algorithm. This combination of hardware and software maintains a coherent sense of time between multiple ethernet-connected computers, on the order of 100 ns (rms) in the best case, of the timebase established by the local GPS-receiver clock. We illustrate the performance of this techniques in a practical survey system using a Reson 7P sonar processor connected to a Reson 7125 Multibeam Echosounder (MBES), integrated with an Applanix POS/MV 320 V4 and a conventional data capture computer. Using the timing capabilities of the PTP hardware implementations, we show that the timepieces achieve mean (hardware based) synchronization and timestamping within 100-150 ns (rms), and that the data created at the Reson 7P without hardware timestamps has a latency variability of 28 µs (rms) due to software constraints within the capture system. This compares to 288 ms (rms) using Reson’s standard hybrid hardware/software solution, and 13.6 ms (rms) using a conventional single-oscillator timestamping model

Optimal strategies for regional cultivar testing

In undertaking cultivar trials, the variability of the response of the cultivars to the different environments in which they are grown introduces the possibility of release errors and non‐release errors in the decisions made on the basis of the trial results. In this article a model is developed that accounts for the economic costs of those errors as well as the costs of operating the trials, and enables the features of the optimal cultivar testing program to be identified. The model is illustrated by application to wheat cultivar trials in central and southern NSW.Crop Production/Industries,

A Complex Interaction Between Reduced Reelin Expression and Prenatal Organophosphate Exposure Alters Neuronal Cell Morphology.

Genetic and environmental factors are both likely to contribute to neurodevelopmental disorders including schizophrenia, autism spectrum disorders, and major depressive disorders. Prior studies from our laboratory and others have demonstrated that the combinatorial effect of two factors-reduced expression of reelin protein and prenatal exposure to the organophosphate pesticide chlorpyrifos oxon-gives rise to acute biochemical effects and to morphological and behavioral phenotypes in adolescent and young adult mice. In the current study, we examine the consequences of these factors on reelin protein expression and neuronal cell morphology in adult mice. While the cell populations that express reelin in the adult brain appear unchanged in location and distribution, the levels of full length and cleaved reelin protein show persistent reductions following prenatal exposure to chlorpyrifos oxon. Cell positioning and organization in the hippocampus and cerebellum are largely normal in animals with either reduced reelin expression or prenatal exposure to chlorpyrifos oxon, but cellular complexity and dendritic spine organization is altered, with a skewed distribution of immature dendritic spines in adult animals. Paradoxically, combinatorial exposure to both factors appears to generate a rescue of the dendritic spine phenotypes, similar to the mitigation of behavioral and morphological changes observed in our prior study. Together, our observations support an interaction between reelin expression and chlorpyrifos oxon exposure that is not simply additive, suggesting a complex interplay between genetic and environmental factors in regulating brain morphology

Numerical Computations For Pde Models Of Rocket Exhaust Flow In Soil

We study numerical methods for solving the nonlinear porous medium and Navier-Lame problems. When coupled together, these equations model the flow of exhaust through a porous medium, soil, and the effects that the pressure has on the soil in terms of spatial displacement. For the porous medium equation we use the Crank-Nicolson time stepping method with a spectral discretization in space. Since the Navier-Lame equation is a boundary value problem, it is solved using a finite element method where the spatial domain is represented by a triangulation of discrete points. The two problems are coupled by using approximations of solutions to the porous medium equation to define the forcing term in the Navier-Lame equation. The spatial displacement solutions can be used to approximate the strain and stress imposed on the soil. An analysis of these physical properties shows whether or not the material ceases to act as an elastic material and instead behaves like a plastic which will tell us if the soil has failed and a crater has formed. Analytical as well as experimental tests are used to find a good balance for solving the porous medium and Navier-Lame equations both accurately and efficiently

A history of the Kennedy Earls of Cassillis before 1576

This thesis will study the Kennedy family, beginning with its origins as a minor cadet branch of the lineage that ruled Galloway in the twelfth century, and trace its history until the death of the fourth earl of Cassillis in 1576. A study of how the Kennedys extended their influence across south-west Scotland and acquired an earldom has never been undertaken. This thesis aims to fill the significant gap in our understanding of how lordship operated in this region. In particular, analysis of the interactions between the Kennedys and the earls of Carrick, usually the monarch or his heir, demonstrates that the key factor in their success was their policy of close alignment and support of the crown. The Kennedy kindred were the dominant force in Carrick in south-west Scotland from the middle of the fourteenth century. Their first appearance in the historical record in the late twelfth century makes it likely that the Kennedys were connected to the kindred of Fergus, Lord of Galloway. His grandson Duncan became the first earl of Carrick when that territory was separated from Galloway. Duncan’s lineage was known as the ‘de Carricks’ and the Bruce family gained the earldom through marriage to a ‘de Carrick’ heiress. The earldom of Carrick then became connected to the crown and, when the male line of the ‘de Carricks’ failed, Robert II recognised John Kennedy of Dunure as the rightful leader of the kindreds within Carrick. For over two hundred years the principal Kennedy line exerted a powerful lordship in Carrick which later extended into western Galloway. The family’s dominance in the area and their loyalty to the crown was recognised when the head of the Kennedys was made a lord of parliament in 1458. The Kennedy chief was granted a comital title in 1509 and the Kennedy earls of Cassillis were highly influential during the reigns of James V and Mary Queen of Scots. The power and influence of the Kennedy chiefs has been acknowledged by historians but there has been limited study of the kindred. As bailies to the earls of Carrick, usually the monarch or the heir to the throne, the Kennedys may have been seen as playing a secondary role within the province. Studies have examined the life of individual Kennedys and the mechanisms used by some Kennedy chiefs to exert their lordship in an area where Gaelic kinship practices still operated. However, until now the history of the Kennedy dynasty has never been subjected to in-depth analysis