An experimental and finite element poroelastic creep response analysis of an intervertebral hydrogel disc model in axial compression

A hydrogel intervertebral disc (lVD) model consisting of an inner nucleus core and an outer anulus ring was manufactured from 30 and 35% by weight Poly(vinyl alcohol) hydrogel (PVA-H) concentrations and subjected to axial compression in between saturated porous endplates at 200 N for 11 h, 30 min. Repeat experiments (n = 4) on different samples (N = 2) show good reproducibility of fluid loss and axial deformation. An axisymmetric nonlinear poroelastic finite element model with variable permeability was developed using commercial finite element software to compare axial deformation and predicted fluid loss with experimental data. The FE predictions indicate differential fluid loss similar to that of biological IVDs, with the nucleus losing more water than the anulus, and there is overall good agreement between experimental and finite element predicted fluid loss. The stress distribution pattern indicates important similarities with the biological lVD that includes stress transference from the nucleus to the anulus upon sustained loading and renders it suitable as a model that can be used in future studies to better understand the role of fluid and stress in biological IVDs. (C) 2005 Springer Science + Business Media, Inc.

Extending choreography with business contract constraints

Business contracts play a central role in governing commercial interactions between organizations. It is increasingly recognized that business contract conditions need to be closely linked to internal and external business processes, both to reduce the risk of contract violations and to ensure compliance with legislative regimes. Recent research has proposed contract languages allowing the specification of obligations, permissions and prohibitions in business contracts. Business processes that cross-organizational boundaries can be specified in choreography and coordination languages but these do not provide appropriate abstractions for contract constraints. In this paper, we examine the transformation of contract constraints in a business contract language into expressions in a choreography language. An example cross-organizational process is presented, along with a specification of the process in a choreography language and a specification of a set of contract conditions for the process in a business contract language. The contract terms are then translated into choreography expressions that govern the process to ensure compliance. Subsequent discussion explores a number of business and technology issues related to the results. We conclude that cross-organizational business processes can be monitored and enforced according to business contract specifications through the transformation of a contract definition to constraints on process behavior.

Building business cases for maintenance improvement projects

Many maintenance managers find it difficult to justify investments in maintenance improvement initiatives. In part, this is due to a tendency by mine managers to regard maintenance purely as a cost centre, and not as a process able to influence productive capacity and profit. It is also hindered by a lack of alignment between commonly used maintenance performance measures and key business drivers, and the lack of formal business training amongst maintenance professionals. With this in mind, a model to assist maintenance managers in evaluating the benefits of maintenance improvement projects was recently formulated. The model considers four cost saving dimensions. These are: 1. reduction in the cost of unplanned repairs and maintenance, 2. increased or accelerated production and/or sales, 3. spares inventory reduction, and 4. reduction in over-investment in physical assets and operating costs. This paper discusses the application of this model and a number of numerical examples are given to justify investments in maintenance improvement projects having varying objectives.

Motorcycle accident risk could be inflated by a time to arrival illusion

Purpose. Drivers adopt smaller safety margins when pulling out in front of motorcycles compared with cars. This could partly account for why the most common motorcycle/car accident involves a car violating a motorcyclist's right of way. One possible explanation is the size-arrival effect in which smaller objects are perceived to arrive later than larger objects. That is, drivers may estimate the time to arrival of motorcycles to be later than cars because motorcycles are smaller. Methods. We investigated arrival time judgments using a temporal occlusion paradigm. Drivers recruited from the student population (n = 28 and n = 33) saw video footage of oncoming vehicles and had to press a response button when they judged that vehicles would reach them. Results. In experiment 1, the time to arrival of motorcycles was estimated to be significantly later than larger vehicles (a car and a van) for different approach speeds and viewing times. In experiment 2, we investigated an alternative explanation to the size-arrival effect: that the smaller size of motorcycles places them below the threshold needed for observers to make an accurate time to arrival judgment using tau. We found that the motorcycle/car difference in arrival time estimates was maintained for very short occlusion durations when tau could be estimated for both motorcycles and cars. Conclusions. Results are consistent with the size-arrival effect and are inconsistent with the tau threshold explanation. Drivers estimate motorcycles will reach them later than cars across a range of conditions. This could have safety implications.

Eco-efficiency and dairy processing

The dairy industry is a global industry that provides significant nutritional benefit to many cultures. in australia the industry is especially important economically, being a large export earner, as well as a vital domestic sector. in recent years the sector has come under increased competitive pressure and has restructured to cope with the changes. the industry recently undertook an eco-efficiency project to investigate where business and environmental improvements might be found. the project involved collecting and collating previous project data and surveying 38 companies in different dairy operations, from market milk to dried products. after the survey, 10 sites in two states were visited to discuss eco-efficiency issues in detail with key players. From the surveys, visits and data compilation, a comprehensive manual was prepared to help interested companies find relevant eco-efficiency data easily and assist them in the implementation process. ten fact sheets were also produced covering the topics of water management, water recycling and re-use, refrigeration optimisation, boiler optimisation, biogas, the use of treated wastewater, yield optimisation and product recovery, optimisation of ciP systems, chemical use and membranes the project highlighted the large amount of technical and engineering expertise within the sector that could result in eco-efficiency outcomes and also identified the opportunities that exist for changes to occur in some operations to save energy, input raw materials and water.

The Australian Universities Teaching Committee project in 'Learning Outcomes and Curriculum Development in Psychology'

The Australian Universities Teaching Committee (AUTC) funds projects intended to improve the quality of teaching and learning in specific disciplinary areas. The project brief for 'Learning Outcomes and Curriculum Development in Psychology' for 2004/2005 was to 'produce an evaluative overview of courses ... with a focus on the specification and assessment of learning outcomes and ... identify strategic directions for universities to enhance teaching and learning'. This project was awarded to a consortium from The University of Queensland, University of Tasmania, and Southern Cross University. The starting point for this project is an analysis of the scientist-practitioner model and its role in curriculum design, a review of current challenges at a conceptual level, and consideration of the implications of recent changes to universities relating to such things as intemationalisation of programs and technological advances. The project will seek to bring together stakeholders from around the country in order to survey the widest possible range of perspectives on the project brief requirements. It is hoped also to establish mechanisms for fiiture scholarly discussion of these issues, including the establishment of an Australian Society for the Teaching of Psychology and an annual conference.

Experience as a moderator of involvement and satisfaction on brand loyalty in a business-to-business setting 02-314R

This paper examines the relative influence of two key antecedents of brand loyalty-satisfaction and involvement and the moderating role of experience, using a sample of business buyers. The central argument of this paper is that the strength of the effect of these variables on attitudinal brand loyalty will vary with the level of customer experience with purchasing the service. Building on previous research which examined low-risk, customer product settings [Kim, J., Lim, J.S., & Bhargava, M. (1998). The role of affect in attitude formation: A classical conditioning approach. Journal of the Academy of Marketing Science 26 (2): pp. 143-152; Shiv, B., & Fedorikhin, A. (1999). Heart and mind in conflict: The interplay of affect and cognition in consumer decision-making. Journal of Consumer Research 26: 278], this study shows that for a high-risk setting, involvement with the service category will be more dominant in its influence on brand loyalty than satisfaction with the preferred brand. Furthermore, it was found that experience moderated the influence of involvement and satisfaction on attitudinal brand loyalty for a high-risk business-to-business service. This study provides new insights into the theory and practice of buyer behavior and business-to-business brands. Crown Copyright (C) 2004 Published by Elsevier Inc. All rights reserved.

How do practitioners use conceptual modeling in practice?

Much research has been devoted over the years to investigating and advancing the techniques and tools used by analysts when they model. As opposed to what academics, software providers and their resellers promote as should be happening, the aim of this research was to determine whether practitioners still embraced conceptual modeling seriously. In addition, what are the most popular techniques and tools used for conceptual modeling? What are the major purposes for which conceptual modeling is used? The study found that the top six most frequently used modeling techniques and methods were ER diagramming, data flow diagramming, systems flowcharting, workflow modeling, UML, and structured charts. Modeling technique use was found to decrease significantly from smaller to medium-sized organizations, but then to increase significantly in larger organizations (proxying for large, complex projects). Technique use was also found to significantly follow an inverted U-shaped curve, contrary to some prior explanations. Additionally, an important contribution of this study was the identification of the factors that uniquely influence the decision of analysts to continue to use modeling, viz., communication (using diagrams) to/from stakeholders, internal knowledge (lack of) of techniques, user expectations management, understanding models' integration into the business, and tool/software deficiencies. The highest ranked purposes for which modeling was undertaken were database design and management, business process documentation, business process improvement, and software development. (c) 2005 Elsevier B.V. All rights reserved.

The oil shock of 2005

During the course of 2005, the price of crude oil reached unprecedented high levels, at least in nominal terms. Australian motorists have become used to paying more than a dollar a litre for petrol. Given the past volatility in oil prices, often described in terms of a series of oil ‘shocks’ (the large price increases in 1973, 1979 and 1999), several questions arise. First, will current high prices persist, or will prices decline substantially as occurred after previous oil shocks? Second, is the current shortage of oil a temporary phenomenon, caused by inadequate investment in oil exploration, drilling and refining capacity, or is it a signal that the supply of oil available to the world has peaked? Third, will high oil prices lead to broader economic disruption, as is commonly supposed to have happened after previous shocks? Fourth, how painful will an adjustment to lower use of oil be? Finally, how does all this relate to our efforts to deal with the problem of climate change? This article is an effort to answer some of these questions in the light of the knowledge available to us.