Development and Implementation of an Advanced Analytical Approach for Flexible Pavement Analysis and Design in Western Australia

An advanced method for analysis of pavement having thin wearing surface layer is proposed. A mechanistic approach, based on disturbed state concept, was adopted for material modelling. A 3D column-strip model of pavement structures was then introduced using finite element method. Results indicate that the proposed approach can be used in predicting the permanent deformation of pavement structures and provides realistic resultant stresses and deformations because important engineering properties can be incorporated in the calculation

Numerical Study of Forced Air Cooling of a Heated Porous Foam Pyramid array

The current study employs CFD to study the forced air cooling of a pyramid shaped porous foam absorber. Herein, a three by three (3×3) array of porous foam absorbers heated with an external heat flux is modeled using the differential equations governing heat and fluid flow through porous media based on the Brinkman-Darcy flow equations and an effective thermal conductivity to account for the porous medium. The numerical simulations are carried out using the COMSOL commercial Computational Fluid Dynamics (CFD) Finite Element based software package. The primary finding of our study is that the more porous the foam absorber media is, the more dependent the effective thermal conductivity is on the thermal conductivity of the fluid used for cooling. If the fluid is air, which has a very low thermal conductivity, the effective thermal conductivity is decreased as the porosity increases, thus diminishing removal of heat from the foam array via the cooling air stream. Based on the parametric study, the best case operating conditions which may allow the pyramidal foam absorber to stay within the max allowable temperature are as follows: porosity = 0.472, inlet air cooling velocity = 50 m/s

A preliminary study on characterisation of mechanical behaviour of hydrated cement treated crushed rock base using the disturbed state concept

For road pavements in Western Australia, base layers are usually constructed using hydrated cement treated crushed rock base (HCTCRB) of which the mechanistic properties with the reliable material model are necessary for rational pavement analysis and design. The purpose of this study is to present the experimental results produced from the assessment of the mechanical behaviour of HCTCRB and the material modelling based on the Disturbed State Concept theory-based process. The results reveal that HCTCRB can be treated as cohesive granular material where its internal friction angle (ø) is 43° and its cohesion (c) is 168 kPa. The Disturbed State Concept (DSC) and K-θ model can be used for establishing the relationship between the resilient moduli and the applied stresses. The permanent deformation of HCTCRB can be predicted by using models such as the DSC model and G.T.H. Sweere,’s model, which are presented in this paper. The use of the DSC model shows the advantage of showing the relationship between permanent deformations and applied stresses (σ1, σ3), and these are derived from the resilient modulus equation

Numerical Simulation of 3-D free convection in porous media due to combined surface forced convection and internal heat generation

A three-dimensional fluid-saturated porous medium model for natural convective flow has been developed, taking into account inertial and viscous forces within the fluid. The model consists of a cube with a top surface partially exposed to a steady, uniform convective heat flux and the entire domain to uniform internal heat generation. The differential equations for the Brinkman-extended Darcy model were formulated and non-dimensionalized, with numerical solutions obtained using the Galerkin finite element method. The results have been validated by comparison with previously published reports. It has been observed that the applied boundary conditions result in a central toroidal vortex driven by buoyancy, which in turn influences the isothermal profile. The shape and intensity of these vortices is significantly affected by a combination of dimensionless parameters such as Rayleigh number, Darcy number, and porosity

Constitutive Modelling of Hydrated Cement Treated Crush Rock Base with Cyclic-loading Behaviour

Hydrated Cement Treated Crush Rock Base (HCTCRB) is a unique road base material developed and commonly used for Western Australia roads. This paper presents the application of disturbed state concept (DSC) for the constitutive modelling of HCTCRB. DSC was adopted as the modelling approach because of its simplicity and yet is powerful in capturing the elastic and inelastic responses of materials to loading and unloading-reloading history. The DSC constitutive model depends on the main assumption that the actual material deformation, at any loading state, can be determined from its assumed relative intact (RI) state. DSC equations are derived based on an idealised material model of the RI state, namely linear elastic RI state. The use of the idealised linear elastic RI state leads to a unified stress-strain equation in terms of the stress and strain values at the maximum yielding and ultimate limit states. The DSC models are found to be in good correlation with the actual HCTCRB behaviour based on the test data. The proposed constitutive model is also suitable for predicting the resilient modulus of HCTCRB, which will be presented and verified

CRITICAL SUCCESS FACTORS (CSFs) OF THE ORGANISATIONAL CHANGE IN THE DISRUPTIVE TECHNOLOGY CONVERGENCE OF THE GOVERNMENTAL REGULATORY ORGANISATION

The impacts of the disruptive technology convergence of broadcasting and telecommunications is currently considered as the most important critical external factor among other external environmental factors, which is driven by the development of the high-speed internet infrastructure. The governmental regulatory organisation has to adapt to this significant impacts through the organisational change management. However, the studies of both empirical and theoretical as well as experienced based have not identified the Critical Success Factors (CSFs) that provide statistically significant positive relations for a successful organisational change management. If the Critical Success Factors (CSFs) can be identified during the organisational change implementation process, then the organisational change management team can use it to focus more on critical areas that are highly important to implement the organisational change effectively and successfully. The major objectives of this research are focused on the action research (AR) to (1) develop the Critical Success Factors (CSFs) Taxonomy of the Organisational Change Management, (2) develop the new redesign of the business processes of the Business Process Management (BPM), and (3) develop the Key Performance Indicators (KPIs) Taxonomy of the Business Process Management (BPM). This research study focuses on the new combined broadcasting and telecommunications licensing bureau of the Office of the National Broadcasting and Telecommunications Commission (NBTC). The mixed method research is used to conduct this action research (AR). The qualitative method is implemented through in-depth and semi-structured interview to nine participants, namely senior directors of the NBTC, senior executives of broadcasting operators, senior executives of telecommunications operators, and a senior academic researcher. The quantitative method to analyse and present the research data using statistical analysis through Excel Computer Software to make the research outcomes be more complete. The main findings show that the Critical Success Factors (CSFs) Taxonomy of the Organisational Change Management consists of four categorized factors include (1) Organisational Critical Success Factors (CSFs), (2) Human Capital Critical Success Factors (CSFs), (3) Operations Critical Success Factors (CSFs), and (4) Technology Critical Success Factors (CSFs). These Organisational Critical Success Factors (CSFs) are classified into three classes include class A:CSFs (most important), class B:CSFs (second most important) and class C:CSFs (third most important). In addition, the outcome of the Key Performance Indicators (KPIs) Taxonomy of the Business Process Management (BPM) is classified into three classes include class A:KPIs (most important), class B:KPIs (second most important) and class C:KPIs (third most important). The validation of the acceptability and the usefulness of the Critical Success Factors (CSFs) Taxonomy of the Organisational Change Management and KPIs Taxonomy of the Business Process Management (BPM) results are both highly acceptable to both Organisational Change Management and the Business Process Management (BPM). The validation of the contributions of the proposed Taxonomies to the Organisational Change Management concepts is considered as of a high consistency. Therefore, the proposed Taxonomies provide the benefits to the Organisational Change Management concepts. In addition, the validation of contributions of the proposed taxonomies to the Knowledge Management (KM) is considered as of a high consistency. The implications of this study show that the Critical Success Factors (CSFs) Taxonomy of the Organisational Change Management and the Key Performance Indicators (KPIs) Taxonomy provide great benefits and contributions to both theoretical and practical implications. The theoretical implication shows that the Critical Success Factors (CSFs) Taxonomy of the Organisational Change Management does not create a new academic theory. However, it does provide a complement to the relevant organisational change management concept in terms of the relationship of the Critical Success Factors (CSFs) and the Organisational Change Management theory. The organisational change management can use the Critical Success Factors (CSFs) Taxonomy as the major focused areas that the organisation must allocate time and critical resources enough for these areas to ensure the successful organisational change implementation. The Key Performance Indicators (KPIs) Taxonomy of the Business Process Management (BPM) is complementary to the performance management system and the Business Process Management (BPM) theory. An organisation can use these study results as learning tools to learn new knowledge of the importance and the relationship, and this can enhance the organisational capability to cope with the disruptive technology convergence of broadcasting and telecommunications. Furthermore, the organisation can capture and transfer both explicit and tacit knowledge and experience of the success of the Organisational Change Management and the Business Process Management (BPM) related to the Critical Success Factors (CSFs) and the Key Performance Indicators (KPIs) respectively to other bureaus or to a new generation of employees within their organisation to build up the competence and capability of the Organisational Change Management and the Business Process Management (BPM) as a Knowledge Management (KM) system. The recommendations for future study are to extend the action research study to other 37 bureaus as well as across the organisation of the NBTC in order to implement both Organisational Change Management and the Business Process Management (BPM) throughout the NBTC completely and successfully. In addition, the future research study should also cover the monitoring, evaluating and taking corrective actions of both proposed taxonomies that might be affected from the dynamic changing disruptive technology convergence of broadcasting and telecommunications. The final recommendation suggests applying this action research study to other organisations in both governmental and private sectors

Numerical Analysis on the Two-Dimensional Unsteady Magnetohydrodynamic Compressible Flow through a Porous Medium

In the present study, the unsteady magnetrohydrodynamic (MHD) flow of compressible fluid with variable thermal properties has been numerically investigated. The electrically conducting fluid flows through a porous media channel. The uniform magnetic field is applied perpendicular to the direction of the flow. The wall is assumed to be non-conducting and maintained at two different temperatures. The thermal conductivity and viscosity of the fluid change with temperature. Sixth - Order Accurate Compact Finite Difference scheme together with the Third-order Runge-Kutta method is used to solve a set of non-linear equations. The results of the calculation are expressed in the form of the velocity and temperature at different values of the magnetic field and porosity. The proposed mathematical model and numerical methods have been validated by comparing with the results of previously published studies that the compared results reveal the same trends. The difference is due to the compressibility and property variation effects. The results showed that the magnetic field and variable properties considerably influences the flows that is compressible thereby affecting the heat transfer as well as the wall shear stress

Complications after coronectomy of third molars

ABSTRACT   Background Removal of mandibular third molars can be associated with postoperative complications. Coronectomy with partial removal of the crown, is described as an alternative surgical method when risks for post-operative complications are substantial.  Aim  The aim of this study was to evaluate risk factors for post-operative complications after coronectomy.   Materials and Methods Fifty-six patients (26 men/30 women, median age 51 years) were operated with coronectomy of mandibular third molars. Risk factors were identified from medical records and radiographic examinations. Post-operative complications lasting over 14 days were registered.   Results  Fifty percent of the patients had a post-operative complication with significant higher risk for complications for patients over 51 years (p = 0.016). The most common complications were pain from surgical site and local infection. Three patients were registered with affected sensory function. Root migration was registered in 16 patients. Gender, comorbidity, medication, tobacco use, cause of referral (bacterial/other causes) or angulation of the third molar did not affect the risk for complications. Conclusion  The results indicate that coronectomy is an appropriate surgical technique when the risks for postoperative complications are significant, although a high level of short-term complications has been observed.