Flow of a micropolar fluid bounded by a stretching sheet

We consider boundary layer flow of a micropolar fluid driven by a porous stretching sheet. A similarity solution is defined, and numerical solutions using Runge-Kutta and quasilinearisation schemes are obtained. A perturbation analysis is also used to derive analytic solutions to first order in the perturbing parameter. The resulting closed form solutions involve relatively complex expressions, and the analysis is made more tractable by a combination of offline and online work using a computational algebra system (CAS). For this combined numerical and analytic approach, the perturbation analysis yields a number of benefits with regard to the numerical work. The existence of a closed form solution helps to discriminate between acceptable and spurious numerical solutions. Also, the expressions obtained from the perturbation work can provide an accurate description of the solution for ranges of parameters where the numerical approaches considered here prove computationally more difficult.

Solutions for the flow of a micropolar fluid in a porous channel

How various additives can increase some cardio-vascular diseases and effects of transport for albumin and glucose through permeable membranes are some important studies in biomechanics. The rolling phenomena of the leucocytes gives rise to an inflammatory reaction along a vascular wall. Initiated by Eringen [5], a micropolar fluid is a satisfactory model for flows of fluids which contain micro-constituents which can undergo rotation.

Initial CFD investigation of an MR fluid in a bicycle ergometer

A bicycle ergometer is a scientific device used by exercise physiologists which attempts to mimic on-road cycling characteristics such as foot technique, EMG activity, VO2, VCO2 and rider cardiology in a laboratory environment. Presently there are no known useful scientific ergometers that mimic these characteristics and are able to provide a satisfactory controlled resistance that is independent of speed. Previous research has suggested the use of a Magneto-Rheological (MR) Fluid as part of the ergometer design, as when used in a rotary brake application it is able to be controlled electronically to increase resistance instantly and independent of speed. In the target application, MR fluids are subject to immense tribological wear and temperature during viscous shearing, and will eventually show some degree of deterioration which is usually manifested as an increase in off-state viscosity. It is not known exactly how the fluid fails, however the amount of deterioration is related to the shear rate, temperature and duration and directly related to the power dissipation. Currently, there is very little literature that investigates the flow and thermal characteristics of MR fluid tribology using CFD. In this paper, we present initial work that aims to improve understanding of MR fluid wear via CFD modelling using Fluent, and results from the model are compared with those obtained from a experimental test rig of an MR fluid-based bicycle ergometer.

Computational fluid dynamics of a centrifugal heart pump as biventricular assist device(BVAD)

The results of a recent study have shown that there is a severe shortage of donor hearts to meet the demand of patients suffering from acute heart failures, and patients who received a left ventricular assist device (LVAD) have extended lives. However, some of them develop right heart failure syndrome, and these patients required a right ventricular assist device (RVAD). Hence, current research focus is in the development of a bi-ventricular assist device (Bi-VAD). Computational Fluid Dynamics (CFD) is useful for estimating blood damage for design of a Bi-VAD centrifugal heart pump to meet the demand of the left and right ventricles of a normal hearts with a flow rate of 5 lit/min and the supply pressure of 100 mmHg for the left ventricle and 20 mmHg for the right ventricle. Numerical studies have been conducted to predict pressure, flow rate, the velocity profiles, and streamlines in a continuous flow Bi-VAD using. Based on the predictions of numerical simulations, only few flow regions in the Bi-VAD exhibited signs of velocity profiles and stagnation points, thereby signifying potentially low levels of thrombogenesis.

Automating the extraction of quantities

The Automated Estimator and LCADesign are two early examples of nD modelling software which both rely on the extraction of quantities from CAD models to support their further processing. The issues of building information modelling (BIM), quantity takeoff for different purposes and automating quantity takeoff are discussed by comparing the aims and use of the two programs. The technical features of the two programs are also described. The technical issues around the use of 3D models is described together with implementation issues and comments about the implementation of the IFC specifications. Some user issues that emerged through the development process are described, with a summary of the generic research tasks which are necessary to fully support the use of BIM and nD modelling.

Amniotic fluid stem cells produce robust mineral deposits on biodegradable scaffolds

Insufficient availability of osteogenic cells limits bone regeneration through cell-based therapies. This study investigated the potential of amniotic fluid–derived stem (AFS) cells to synthesize mineralized extracellular matrix within porous medical-grade poly-e-caprolactone (mPCL) scaffolds. The AFS cells were initially differentiated in two-dimensional (2D) culture to determine appropriate osteogenic culture conditions and verify physiologic mineral production by the AFS cells. The AFS cells were then cultured on 3D mPCL scaffolds (6-mm diameter9-mm height) and analyzed for their ability to differentiate to osteoblastic cells in this environment. The amount and distribution of mineralized matrix production was quantified throughout the mPCL scaffold using nondestructive micro computed tomography (microCT) analysis and confirmed through biochemical assays. Sterile microCT scanning provided longitudinal analysis of long-term cultured mPCL constructs to determine the rate and distribution of mineral matrix within the scaffolds. The AFS cells deposited mineralized matrix throughout the mPCL scaffolds and remained viable after 15 weeks of 3D culture. The effect of predifferentiation of the AFS cells on the subsequent bone formation in vivo was determined in a rat subcutaneous model. Cells that were pre-differentiated for 28 days in vitro produced seven times more mineralized matrix when implanted subcutaneously in vivo. This study demonstrated the potential of AFS cells to produce 3D mineralized bioengineered constructs in vitro and in vivo and suggests that AFS cells may be an effective cell source for functional repair of large bone defects

Toward a fuzzy domain ontology extraction method for adaptive e-learning

With the widespread applications of electronic learning (e-Learning) technologies to education at all levels, increasing number of online educational resources and messages are generated from the corresponding e-Learning environments. Nevertheless, it is quite difficult, if not totally impossible, for instructors to read through and analyze the online messages to predict the progress of their students on the fly. The main contribution of this paper is the illustration of a novel concept map generation mechanism which is underpinned by a fuzzy domain ontology extraction algorithm. The proposed mechanism can automatically construct concept maps based on the messages posted to online discussion forums. By browsing the concept maps, instructors can quickly identify the progress of their students and adjust the pedagogical sequence on the fly. Our initial experimental results reveal that the accuracy and the quality of the automatically generated concept maps are promising. Our research work opens the door to the development and application of intelligent software tools to enhance e-Learning.

Context-based chemistry : creating opportunities for fluid transitions between concepts and context

Nationally and internationally, context-based programs have been implemented in an attempt to engage students in chemistry through connecting the canonical science with the real-world. In Queensland, a context-based approach to chemistry was trialled in selected schools from 2002 but there is little research that investigates how students learn in a context-based setting. This paper presents one significant finding from an ethnographic study that explored the learning that occurred in an 11th grade context-based chemistry classroom in Queensland. The study found that by providing students with the opportunity to write, fluid transitions (or to-ing and fro-ing) between concepts and context were an outcome of context-based learning.

Dense Correspondence Extraction in Difficult Uncalibrated Scenarios

The relationship between multiple cameras viewing the same scene may be discovered automatically by finding corresponding points in the two views and then solving for the camera geometry. In camera networks with sparsely placed cameras, low resolution cameras or in scenes with few distinguishable features it may be difficult to find a sufficient number of reliable correspondences from which to compute geometry. This paper presents a method for extracting a larger number of correspondences from an initial set of putative correspondences without any knowledge of the scene or camera geometry. The method may be used to increase the number of correspondences and make geometry computations possible in cases where existing methods have produced insufficient correspondences.

The role of fluid and emotional intelligence in malingering

The purpose of the present study was to examine the role of fluid (gf), social (SI) and emotional intelligence (EI) in faking the Beck Depression Inventory (2nd ed., BDI-II). Twenty-two students and 26 non-students completed Raven’s Advanced Progressive Matrices (APM), a social insight test, the Schutte et al. self-report EI scale, and the BDI-II under honest and faking instructions. Results were consistent with a new model of successful faking, in which a participant’s original response must be manipulated into a strategic response, which must match diagnostic criteria. As hypothesised, the BDI-II could be faked, and gf was not related to faking ability. Counter to expectations, however, SI and EI were not related to faking ability. A second study explored why EI failed to facilitate faking. Forty-nine students and 50 non-students completed the EI measure, the Marlowe-Crown Scale and the Levenson et al. Psychopathy Scale. As hypothesised, EI was negatively correlated with psychopathy, but EI showed no relationship with socially desirable responding. It was concluded that in the first experiment, high-EI people did fake effectively, but high-psychopathy people (who had low EI) were also faking effectively, resulting in a distribution that showed no advantage to high EI individuals.

Towards an automatic road lane marks extraction based on ISODATA segmentation and shadow detection from large-scale aerial images

The automatic extraction of road features from remote sensed images has been a topic of great interest within the photogrammetric and remote sensing communities for over 3 decades. Although various techniques have been reported in the literature, it is still challenging to efficiently extract the road details with the increasing of image resolution as well as the requirement for accurate and up-to-date road data. In this paper, we will focus on the automatic detection of road lane markings, which are crucial for many applications, including lane level navigation and lane departure warning. The approach consists of four steps: i) data preprocessing, ii) image segmentation and road surface detection, iii) road lane marking extraction based on the generated road surface, and iv) testing and system evaluation. The proposed approach utilized the unsupervised ISODATA image segmentation algorithm, which segments the image into vegetation regions, and road surface based only on the Cb component of YCbCr color space. A shadow detection method based on YCbCr color space is also employed to detect and recover the shadows from the road surface casted by the vehicles and trees. Finally, the lane marking features are detected from the road surface using the histogram clustering. The experiments of applying the proposed method to the aerial imagery dataset of Gympie, Queensland demonstrate the efficiency of the approach.