Studies on the effect of the size of polycaprolactone microspheres for the dispersion of Salbutamol Sulfate from dry powder inhaler formulations

Purpose: To study the effect of the size of the surface-coated polycaprolactone (PCL) microparticle carriers on the aerosolization and dispersion of Salbutamol Sulfate (SS) from Dry Powder Inhaler (DPI) formulations. Methods: The microparticles were fabricated using an emulsion technique in four different sizes (25, 48, 104 and 150 μm) and later coated with Magnesium stearate (MgSt) and leucine. They were characterized by laser diffraction and SEM. The Fine Particle Fraction (FPF) of SS from powder mixtures was determined by a Twin Stage Impinger (TSI). Results: As the carrier size increased from 25 μm to 150 μm, the FPF of the SS delivered by the coated PCL particles increased approximately four fold. A linear relationship was found between the FPF and Volume mean Diameter (VMD) of the particles over this range. Conclusions: The dispersion behaviour of SS from PCL carriers was dependent on the inherent size of the carriers and the increased FPF of SS with increased carrier size probably reflects the higher mechanical forces produced due to the carrier-carrier collisions or collisions between the carrier particles and the internal walls of the inhaler during aerosolization.

Computationally efficient methods for solving time-variable-order time-space fractional reaction-diffusion equation

Fractional differential equations are becoming more widely accepted as a powerful tool in modelling anomalous diffusion, which is exhibited by various materials and processes. Recently, researchers have suggested that rather than using constant order fractional operators, some processes are more accurately modelled using fractional orders that vary with time and/or space. In this paper we develop computationally efficient techniques for solving time-variable-order time-space fractional reaction-diffusion equations (tsfrde) using the finite difference scheme. We adopt the Coimbra variable order time fractional operator and variable order fractional Laplacian operator in space where both orders are functions of time. Because the fractional operator is nonlocal, it is challenging to efficiently deal with its long range dependence when using classical numerical techniques to solve such equations. The novelty of our method is that the numerical solution of the time-variable-order tsfrde is written in terms of a matrix function vector product at each time step. This product is approximated efficiently by the Lanczos method, which is a powerful iterative technique for approximating the action of a matrix function by projecting onto a Krylov subspace. Furthermore an adaptive preconditioner is constructed that dramatically reduces the size of the required Krylov subspaces and hence the overall computational cost. Numerical examples, including the variable-order fractional Fisher equation, are presented to demonstrate the accuracy and efficiency of the approach.

Damage quantification techniques in acoustic emission monitoring

Acoustic emission (AE) analysis is one of the several diagnostic techniques available nowadays for structural health monitoring (SHM) of engineering structures. Some of its advantages over other techniques include high sensitivity to crack growth and capability of monitoring a structure in real time. The phenomenon of rapid release of energy within a material by crack initiation or growth in form of stress waves is known as acoustic emission (AE). In AE technique, these stress waves are recorded by means of suitable sensors placed on the surface of a structure. Recorded signals are subsequently analysed to gather information about the nature of the source. By enabling early detection of crack growth, AE technique helps in planning timely retrofitting or other maintenance jobs or even replacement of the structure if required. In spite of being a promising tool, some challenges do still exist behind the successful application of AE technique. Large amount of data is generated during AE testing, hence effective data analysis is necessary, especially for long term monitoring uses. Appropriate analysis of AE data for quantification of damage level is an area that has received considerable attention. Various approaches available for damage quantification for severity assessment are discussed in this paper, with special focus on civil infrastructure such as bridges. One method called improved b-value analysis is used to analyse data collected from laboratory testing.

Providing a law degree for the real world : perspective of an Australian law school

As a result of a two year curriculum review, QUT’s undergraduate law degree has a focus on first year student transition, integration of law graduate capabilities throughout the degree and work integrated learning. A ‘whole-degree’ approach was adopted to ensure that capabilities were appropriately embedded and scaffolded throughout the degree, that teaching and learning approaches met the needs of students as they transitioned from first year through to final year, and that students in final year were provided with a capstone experience to assist them with transition into the work place. The revised degree commenced implementation in 2009. This paper focuses on the ‘real world’ approach to the degree achieved through the first year program, embedding and scaffolding law graduate capabilities through authentic and valid assessment and work integrated learning to assist graduates with transition into the workplace.

Navigational traffic conflict technique: a proactive approach to quantitative measurement of collision risks in port waters

Navigational safety analysis relying on collision statistics is often hampered because of low number of observations. A promising alternative approach that overcomes this problem is proposed in this paper. By analyzing critical vessel interactions this approach proactively measures collision risk in port waters. The proposed method is illustrated for quantitative measurement of collision risks in Singapore port fairways, and validated by examining correlations between the measured risks with those perceived by pilots. This method is an ethically appealing alternative to the collision-based analysis for fast, reliable and effective safety assessment, thus possesses great potential for managing collision risks in port waters.

Modelling port water collision risk using traffic conflicts

Navigational collisions are one of the major safety concerns for many seaports. Despite the extent of work recently done on collision risk analysis in port waters, little is known about the influencing factors of the risk. This paper develops a technique for modeling collision risks in port waterways in order to examine the associations between the risks and the geometric, traffic, and regulatory control characteristics of waterways. A binomial logistic model, which accounts for the correlations in the risks of a particular fairway at different time periods, is derived from traffic conflicts and calibrated for the Singapore port fairways. Estimation results show that the fairways attached to shoreline, traffic intersection and international fairway attribute higher risks, whereas those attached to confined water and local fairway possess lower risks. Higher risks are also found in the fairways featuring higher degree of bend, lower depth of water, higher numbers of cardinal and isolated danger marks, higher density of moving ships and lower operating speed. The risks are also found to be higher for night-time conditions.

Double diffusive magneto-convection fluid flow in a strong cross magnetic field with uniform surface heat and mass flux

In this study, magnetohydrodynamic natural convection boundary layer flow of an electrically conducting and viscous incompressible fluid along a heated vertical flat plate with uniform heat and mass flux in the presence of strong cross magnetic field has been investigated. For smooth integrations the boundary layer equations are transformed in to a convenient dimensionless form by using stream function formulation as well as the free variable formulation. The nonsimilar parabolic partial differential equations are integrated numerically for Pr ≪1 that is appropriate for liquid metals against the local Hartmann parameter ξ . Further, asymptotic solutions are obtained near the leading edge using regular perturbation method for smaller values of ξ . Solutions for values of ξ ≫ 1 are also obtained by employing the matched asymptotic technique. The results obtained for small, large and all ξ regimes are examined in terms of shear stress, τw, rate of heat transfer, qw, and rate of mass transfer, mw, for important physical parameter. Attention has been given to the influence of Schmidt number, Sc, buoyancy ratio parameter, N and local Hartmann parameter, ξ on velocity, temperature and concentration distributions and noted that velocity and temperature of the fluid achieve their asymptotic profiles for Sc ≥ 10:0.

A Fair Go Beyond the School Gate? Systemic factors affecting participation and attainment in tertiary education by Queensland students from LSES backgrounds

The purpose of this project was to conduct an empirical study that would result in findings that inform systemic policy development aimed at improving tertiary participation and attainment by students from low socioeconomic status (LSES) backgrounds in Queensland. The project focuses on systemic policy, initiatives and programs that encourage tertiary education participation and attainment by individuals from LSES backgrounds, rather than on institution-specific initiatives or programs. While the broad remit was to consider tertiary education participation, the study particularly highlights issues pertaining to LSES student participation and attainment in the higher education sector, given the notable under representation of this demographic subgroup in Australian universities. This study supports the strategic priority of addressing professional skills shortages and innovations aiming to improve human and social capital in the state of Queensland. The ultimate goal is to contribute to the enhancement of Queensland’s education and training system by maximising participation and attainment by people from LSES backgrounds in higher education, thereby improving their quality of life and future life choices and opportunities. The study addressed the following five research questions: 1. What are the major factors that promote or inhibit participation and attainment in tertiary education by LSES students in Queensland? 2. To what extent do systemic policies or practices(systemic factors) of Queensland’s tertiary education system promote or inhibit participation and attainment by LSES students? That is, what features of Queensland’s tertiary education system have a significant effect on participation and attainment by LSES students? 3. What system policies or practices are found to boost participation and attainment by LSES students in other jurisdictions? 4. What evidence is there to suggest that policies or practices that have boosted participation and attainment by LSES students in other jurisdictions would be successful if implemented in Queensland? 5. What are the implications of the research findings for Queensland’s tertiary education system to improve participation and attainment by LSES students? The project adopted a mixed methods approach to data collection. A comprehensive review of the literature was conducted to identify relevant state, national and international literature. Both qualitative and quantitative methodologies were used to collect data from a range of key stakeholders.

Developing safer passengers through a school-based injury prevention program

Motor vehicle crashes are a leading cause of death among young people. Fourteen percent of adolescents aged 13-14 report passenger-related injuries within three months. Intervention programs typically focus on young drivers and overlook passengers as potential protective influences. Graduated Driver Licensing restricts passenger numbers, and this study focuses on a complementary school-based intervention to increase passengers’ personal- and peer-protective behavior. The aim of this research was to assess the impact of the curriculum-based injury prevention program, Skills for Preventing Injury in Youth (SPIY), on passenger-related risk-taking and injuries, and intentions to intervene in friends’ risky road behavior. SPIY was implemented in Grade 8 Health classes and evaluated using survey and focus group data from 843 students across 10 Australian secondary schools. Intervention students reported less passenger-related risk-taking six months following the program. Their intention to protect friends from underage driving also increased. The results of this study show that a comprehensive, school-based program targeting individual and social changes can increase adolescent passenger safety.

Field-of-view, detection range, and false alarm trade-offs in vision-based aircraft detection

This paper presents a survey of previously presented vision based aircraft detection flight test, and then presents new flight test results examining the impact of camera field-of view choice on the detection range and false alarm rate characteristics of a vision-based aircraft detection technique. Using data collected from approaching aircraft, we examine the impact of camera fieldof-view choice and confirm that, when aiming for similar levels of detection confidence, an improvement in detection range can be obtained by choosing a smaller effective field-of-view (in terms of degrees per pixel).

“A problem of versions” : laying down the law in the school playground

Purpose This chapter investigates an episode where a supervising teacher on playground duty asks two boys to each give an account of their actions over an incident that had just occurred on some climbing equipment in the playground. Methodology This paper employs an ethnomethodological approach using conversation analysis. The data are taken from a corpus of video recorded interactions of children, aged 7-9 years, and the teacher, in school playgrounds during the lunch recess. Findings The findings show the ways that children work up accounts of their playground practices when asked by the teacher. The teacher initially provided interactional space for each child to give their version of the events. Ultimately, the teacher’s version of how to act in the playground became the sanctioned one. The children and the teacher formulated particular social orders of behavior in the playground through multi-modal devices, direct reported speech and scripts. Such public displays of talk work as socialization practices that frame teacher-sanctioned morally appropriate actions in the playground. Value of paper This chapter shows the pervasiveness of the teacher’s social order, as she presented an institutional social order of how to interact in the playground, showing clearly the disjunction of adult-child orders between the teacher and children.

Real-time detection of concealed chemical hazards under ambient light conditions using Raman spectroscopy

Current concerns regarding terrorism and international crime highlight the need for new techniques for detecting unknown and hazardous substances. A novel Raman spectroscopy-based technique, spatially offset Raman spectroscopy (SORS), was recently devised for non-invasively probing the contents of diffusely scattering and opaque containers. Here, we demonstrate a modified portable SORS sensor for detecting concealed substances in-field under different background lighting conditions. Samples including explosive precursors, drugs and an organophosphate insecticide (chemical warfare agent surrogate) were concealed inside diffusely scattering packaging including plastic, paper and cloth. Measurements were carried out under incandescent and fluorescent light as well as under daylight to assess the suitability of the probe for different real-life conditions. In each case, it was possible to identify the substances against their reference Raman spectra in less than one minute. The developed sensor has potential for rapid detection of concealed hazardous substances in airports, mail distribution centers and customs checkpoints.

Direct evaluation of IEC 61850-9-2 process bus network performance

This letter presents a technique to assess the overall network performance of sampled value process buses based on IEC 61850-9-2 using measurements from a single location in the network. The method is based upon the use of Ethernet cards with externally synchronized time stamping, and characteristics of the process bus protocol. The application and utility of the method is demonstrated by measuring latency introduced by Ethernet switches. Network latency can be measured from a single set of captures, rather than comparing source and destination captures. Absolute latency measures will greatly assist the design testing, commissioning and maintenance of these critical data networks.

Investigating the change in three dimensional deformity for idiopathic scoliosis using axially loaded MRI

Background: Adolescent idiopathic scoliosis is a complex three-dimensional deformity, involving a lateral deformity in the coronal plane and axial rotation of the vertebrae in the transverse plane. Gravitational loading plays an important biomechanical role in governing the coronal deformity, however, less is known about how they influence the axial deformity. This study investigates the change in three-dimensional deformity of a series of scoliosis patients due to compressive axial loading. Methods: Magnetic resonance imaging scans were obtained and coronal deformity (measured using the coronal Cobb angle) and axial rotations measured for a group of 18 scoliosis patients (Mean major Cobb angle was 43.4 o). Each patient was scanned in an unloaded and loaded condition while compressive loads equivalent to 50% body mass were applied using a custom developed compressive device. Findings: The mean increase in major Cobb angle due to compressive loading was 7.4 o (SD 3.5 o). The most axially rotated vertebra was observed at the apex of the structural curve and the largest average intravertebral rotations were observed toward the limits of the coronal deformity. A level-wise comparison showed no significant difference between the average loaded and unloaded vertebral axial rotations (intra-observer error = 2.56 o) or intravertebral rotations at each spinal level. Interpretation: This study suggests that the biomechanical effects of axial loading primarily influence the coronal deformity, with no significant change in vertebral axial rotation or intravertebral rotation observed between the unloaded and loaded condition. However, the magnitude of changes in vertebral rotation with compressive loading may have been too small to detect given the resolution of the current technique.

Mixed convection flow of micropolar fluid in an open ended arc-shape cavity

Numerical simulations for mixed convection of micropolar fluid in an open ended arc-shape cavity have been carried out in this study. Computation is performed using the Alternate Direct Implicit (ADI) method together with the Successive Over Relaxation (SOR) technique for the solution of governing partial differential equations. The flow phenomenon is examined for a range of values of Rayleigh number, 102 ≤ Ra ≤ 106, Prandtl number, 7 ≤ Pr ≤ 50, and Reynolds number, 10 ≤ Re ≤ 100. The study is mainly focused on how the micropolar fluid parameters affect the fluid properties in the flow domain. It was found that despite the reduction of flow in the core region, the heat transfer rate increases, whereas the skin friction and microrotation decrease with the increase in the vortex viscosity parameter, Δ.