High Pressure Isotropic Compression and Grain Crushing of Coarse Granular Materials

The effect of grain crushing and grain size on the evolution of water retention curve is investigated based on the framework of Unsaturated Breakage Mechanics (UBM) (Buscarnera &amp; Einav, 2012). The previous study by Gao et al. (2016) have been complemented by additional compression and soil water retention data on two types of granular soils with coarser and finer initial gradings than the ones presented in Gao et al. (2016). The model satisfactorily captures the co-evolution of suction air-entry value (SAEV) and the degree of grain breakage during compression. In addition, this study revealed that the effect of grain shape and pre-yielding void collapse are necessary components for future enhancement of the breakage mechanics model. The compressive and breakage response of coarse granular materials are further investigated using the High Pressure Isotropic Compression (HPIC) device (Mun &amp; McCartney., 2017). This thesis introduces several troubleshooting attempts of the HPIC device and the developed protocols to conduct high-pressure crushing tests. Coarse quartz sand and crushed shale sand are subjected to the high pressure isotropic compression test under dry and saturated states. Differences between the two materials in the compression curve are observed and the possible reasons are discussed. The compression tests are stopped at various stress levels to allow for inspections on the grain size distribution (GSD). Based on these measures, the degree of grain breakage is quantified via Einav&rsquo;s breakage index (Einav, 2007). A clear increase on grain breakage at elevated stress states and the evolution towards an ultimate fractal state is clearly observed. The obtained results are interpreted using a new 1D breakage model to serve as the basis of the next-generation breakage mechanics models.</p

We Should Agree to Disagree

Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Peer reviewedPublisher PD

Numerical Analysis of Saturated Sand Under Dynamic Loads

In this study, the behavior of reclaimed soils including the effects of excess pore water pressure and the loss of strength under dynamic loads or earthquakes are investigated and simulated. The constitutive model based on the disturbed state concept (DSC) is introduced and DSC-DYN2D program is utilized in a numerical analysis. In the laboratory test, quasi-static and cyclic triaxial tests were carried out to determine parameters for the numerical analysis. Field tests were executed in Inchon International Airport with a 10 tons hydraulic hammer. In the field test, the data of dynamic loads and excess pore water pressure were measured using a 3-D geophone and a pressure transducer respectively, The data of field tests showed the accumulation of excess pore water pressure when rapid dynamic loads were applied. Especially, a back-prediction program based on DSC model is developed and verified its accuracy using various parameters from the cyclic triaxial test. As the results of numerical simulation, the predicted trends for excess pore water pressure compare well with the observed data. Based on the result of this research, it is found that the numerical analysis based on the DSC model is compatible to predict the softening behavior of saturated reclaimed soils under dynamic loads

High speed formation of pyro-carbon coat on silicon carbide fiber by continuous chemical vapor deposition furnace

In order to develop a practical process for the carbon coating on SiC fiber, high-speed and continuous pyrocarbon (PyC) coating process are under development by using a continuous CVD furnace with open-ends structure. The effects of process gas and winding speed have been investigated. It was revealed that the growth rate of PyC is in proportion to winding speed and the flow rate of process gas. PyC growth rate was reached up to 250 nm/min, which is several hundred higher than those of conventional CVI/CVD methods This results indicates that the mass production of PyC coated SiC fiber without unexpected residual deformation (torsion and curvature) is possible. And, the mass production and practical use of SiC/SiC using PyC coated SiC fiber will be largely promoted

Association between body mass index and dental caries in the Kingdom of Saudi Arabia : Systematic Review

Peer reviewe

Cosimulation of MBD (Multi Body Dynamics) and DEM of many spheres using GPU technology

In this paper, dynamic simulation model which have many sphere particles and MBD (Multi Body Dynamics) entities, i.e. bodies, joints, forces, is built and simulated. Many sphere particles are solved with DEM (Discrete Element Method) and simulated with GPU technology. Fast algorithm is applied to calculate hertzian contact forces between many sphere particles (from 100,000 to 1,000,000) and NVIDIA’s CUDA is used to accelerate the calculation. Explicit integration method is applied to solve the many spheres. MBD (Multi Body Dynamics) entities are simulated with recursive formulation. Constraints are reduced by recursive formulation and implicit generalized alpha method is applied to solve dynamic model. Many sphere particles and MBD (Multi Body Dynamics) entities are co-simulated within commercial software RecurDyn. The interaction forces between many sphere particles and rigid body mesh are calculated and applied to each body to simulate two parts simultaneously. These models are built and simulated; fork lifter with sand model, oil in oil tank model, oil filled engine system and water filled washing machine model. All models are simulated with NVIDIA’s GPU and the result is shown

Dental students' knowledge of and attitudes towards prescribing medication in Western Australia

ACKNOWLEDGEMENTThe authors would like to acknowledge UWA dental students for their time and valuable input. Open access publishing facilitated by The University of Western Australia, as part of the Wiley - The University of Western Australia agreement via the Council of Australian University Librarians. [Correction added on 14 May 2022, after first online publication: CAUL funding statement has been added.]Peer reviewedPublisher PD

Cross-sectional analysis of dental treatment under general anaesthesia in hospitalised Western Australian children in 2018-19

Acknowledgements The authors acknowledge the Department of Dental Medicine staff at the Perth Children’s Hospital. The authors also acknowledge Winthrop 588 Australian Health Review Y. F. A. Alshehri et al. Professor Marc Tennant at the School of Human Sciences and Clinical Associate Professor John Winters from Perth Children’s Hospital for their kind support and assistancePeer reviewedPublisher PD

Australian community pharmacists’ ability to identify the indications for dental prescriptions : A case vignette study

Acknowledgement The authors would like to acknowledge Dr Payne for his assistance in the proofreading of this manuscript. Funding A.T.P. is supported by an NHMRC Early Career Fellowship (1156892)Peer reviewedPublisher PD