Reconciling transport models across scales: The role of volume exclusion

Diffusive transport is a universal phenomenon, throughout both biological and physical sciences, and models of diffusion are routinely used to interrogate diffusion-driven processes. However, most models neglect to take into account the role of volume exclusion, which can significantly alter diffusive transport, particularly within biological systems where the diffusing particles might occupy a significant fraction of the available space. In this work we use a random walk approach to provide a means to reconcile models that incorporate crowding effects on different spatial scales. Our work demonstrates that coarse-grained models incorporating simplified descriptions of excluded volume can be used in many circumstances, but that care must be taken in pushing the coarse-graining process too far.

Analytical model of reactive transport processes with spatially variable coefficients

Analytical solutions of partial differential equation (PDE) models describing reactive transport phenomena in saturated porous media are often used as screening tools to provide insight into contaminant fate and transport processes. While many practical modelling scenarios involve spatially variable coefficients, such as spatially variable flow velocity, v(x), or spatially variable decay rate, k(x), most analytical models deal with constant coefficients. Here we present a framework for constructing exact solutions of PDE models of reactive transport. Our approach is relevant for advection-dominant problems, and is based on a regular perturbation technique. We present a description of the solution technique for a range of one-dimensional scenarios involving constant and variable coefficients, and we show that the solutions compare well with numerical approximations. Our general approach applies to a range of initial conditions and various forms of v(x) and k(x). Instead of simply documenting specific solutions for particular cases, we present a symbolic worksheet, as supplementary material, which enables the solution to be evaluated for different choices of the initial condition, v(x) and k(x). We also discuss how the technique generalizes to apply to models of coupled multispecies reactive transport as well as higher dimensional problems.

An economic approach towards estimating health impacts of major transport investments and transport policies: A case study of transport emission abatement policy

The PhD thesis developed an economic model as an integral part of the current Health Impact Assessment (HIA) framework. Based on a Health Production Function approach, the model showed how to estimate economic benefits of positive health gains generated by transport investment programs and transport policies. Using Australian mortality and morbidity statistics and applying econometric analysis, the case study quantified health benefits induced by transport emission abatement policies in dollar terms for the Australian households. Finally, the thesis demonstrated transferability of the economic model through two example case studies, establishing a wider application capacity of the model.

Analyzing hysteresis behavior of capacitance-voltage characteristics of IZO/C₆₀/pentacene/Au diodes with a hole-transport electron-blocking polyterpenol layer by electric-field-induced optical second-harmonic generation measurement

By using electric-field-induced optical second-harmonic generation (EFISHG) measurement, we analyzed hysteresis behavior of capacitance-voltage (C-V) characteristics of IZO/polyterpenol (PT)/C₆₀/pentacene/Au diodes, where PT layer is actively working as a hole-transport electron-blocking layer. The EFISHG measurement verified the presence of interface accumulated charges in the diodes, and showed that a space charge electric field from accumulated excess electrons (holes) that remain at the PT/C₆₀ (C₆₀/pentacene) interface is responsible for the hysteresis loop observed in the C-V characteristics.

Electron-blocking hole-transport polyterpenol thin films

The carrier blocking property of polyterpenol thin films derived from non-synthetic precursor is studied using Electric Field Induced Optical Second Harmonic Generation (EFISHG) technique that can directly probe carrier motion in organic materials. A properly biased double-layer MIM device with a structure of indium zinc oxide (IZO)/polyterpenol/C₆₀/Al shows that by incorporating the polyterpenol thin film, the electron transport can be blocked while the hole transport is allowed. The inherent electron blocking hole transport property is verified using Al/C₆₀/Alq3/polyterpenol/IZO and Al/Alq3/polyterpenol/IZO structures. The rectifying property of polyterpenol is very promising and can be utilized in the fabrication of many organic devices.

A high-density association screen of 155 ion transport genes for involvement with common migraine

The clinical overlap between monogenic Familial Hemiplegic Migraine (FHM) and common migraine subtypes, and the fact that all three FHM genes are involved in the transport of ions, suggest that ion transport genes may underlie susceptibility to common forms of migraine. To test this leading hypothesis, we examined common variation in 155 ion transport genes using 5257 single nucleotide polymorphisms (SNPs) in a Finnish sample of 841 unrelated migraine with aura cases and 884 unrelated non-migraine controls. The top signals were then tested for replication in four independent migraine case-control samples from the Netherlands, Germany and Australia, totalling 2835 unrelated migraine cases and 2740 unrelated controls. SNPs within 12 genes (KCNB2, KCNQ3, CLIC5, ATP2C2, CACNA1E, CACNB2, KCNE2, KCNK12, KCNK2, KCNS3, SCN5A and SCN9A) with promising nominal association (0.00041 < P < 0.005) in the Finnish sample were selected for replication. Although no variant remained significant after adjusting for multiple testing nor produced consistent evidence for association across all cohorts, a significant epistatic interaction between KCNB2 SNP rs1431656 (chromosome 8q13.3) and CACNB2 SNP rs7076100 (chromosome 10p12.33) (pointwise P = 0.00002; global P = 0.02) was observed in the Finnish case-control sample. We conclude that common variants of moderate effect size in ion transport genes do not play a major role in susceptibility to common migraine within these European populations, although there is some evidence for epistatic interaction between potassium and calcium channel genes, KCNB2 and CACNB2. Multiple rare variants or trans-regulatory elements of these genes are not ruled out.

Recruiting/hiring of older workers

This chapter reviews five key components of the recruitment process with regard to an aging workforce. First, targeted recruitment entails that organizations understand the needs, preferences, and strengths of older workers. Second, the recruitment message should communicate job and organizational characteristics that are attractive to older jobseekers. Third, the recruitment source should be consistent with the mediayse and job-search behaviors of older jobseekers. Fourth, the characteristics and behaviors of recruiters play an essential role in the recruitment of older applicants. Finally, organizations need to convey an attractive image of themselves as employers for older workers. Throughout the chapter, best practices are contrasted with available research evidence, and directions for future research are outlined.

Was wollen jüngere und ältere Erwerbstätige erreichen? Altersbezogene Unterschiede in den Inhalten und Merkmalen beruflicher Ziele [What do younger and older workers want to accomplish? Age-related differences in content and characteristics of occupational goals ]

Demographic changes necessitate that companies commit younger workers and motivate older workers through work design. Age-related differences in occupational goals should be taken into account when accomplishing these challenges. In this study, we investigated goal contents and goal characteristics of employees from different age groups. We surveyed 150 employees working in the service sector (average age = 44 years, age range 19 to 60 years) on their most important occupational goals. Employees who stated goals from the area of organizational citizenship were significantly older than employees with other goals. Employees who stated goals from the areas of training and pay/career were significantly younger than employees with other goals. After controlling for gender, education, and work characteristics, no age-related differences were found in the goal areas teamwork, job security, working time, well-being, and new challenges. In addition, no relationships were found between age and the goal characteristics specificity, planning intensity, as well as positive and negative goal emotions. We recommend that companies provide older workers with more opportunities for organizational citizenship and commit younger workers by providing development opportunities and adequate pay

Older workers' age as a moderator of the relationship between career adaptability and job satisfaction

Research on career adaptability and its relationships with work outcomes has so far primarily focused on the cohort of younger workers and largely neglected older workers. We investigated the relationship between career adaptability and job satisfaction in a sample of 577 older workers from Australia (M age = 59.6 years, SD = 2.4, range 54–66 years), who participated in a 4-wave substudy of the 45 and Up Study. Based on socioemotional selectivity theory, we examined older workers’ chronological age (as a proxy for retirement proximity) and motivation to continue working after traditional retirement age as moderators of the relationship between career adaptability and job satisfaction. We hypothesized that the positive relationship between career adaptability and job satisfaction is stronger among relatively younger workers and workers with a high motivation to continue working compared to relatively older workers and workers with a low motivation to continue working. Results showed that older workers’ age, but not their motivation to continue working, moderated the relationship between career adaptability and job satisfaction consistent with the expected pattern. Implications for future research on age and career adaptability as well as ideas on how to maintain and improve older workers’ career adaptability and job satisfaction are discussed.

Teachers as health workers: Patterns and imperatives of Australian teachers’ work

With increasing cross-sectoral relationships and partnerships and the blurring of the boundaries of the various service sectors (Westall 2009), the membrane that is assumed separate education and health in terms of young people’s wellbeing looks thinner than ever. In this project we are concerned to know what teachers do in terms of young people’s health, how much time they spend doing it, and to what extent this work might be considered as health work? The paper is informed by a Likert style survey and semi-structured interview data collected from a large cohort of teachers employed in different school sectors across Queensland, Australia and is framed by Bourdieu’s (1977) ideas around field, practice and doxa. The data suggest that teachers, often with a minimum of training undertake work that might be categorised as health work and do so with a high degree of commitment and with a growing sense of urgency but with concerns related to their competence. We consider it important to understand the reasons why and the extent to which teachers engage in work that might be more readily associated with public health and to ask “are teachers health workers?”

A descriptive analysis of incidents reported by community aged care workers

Little is known about the types of incidents that occur to aged care clients in the community. This limits the development of effective strategies to improve client safety. The objective of the study was to present a profile of incidents reported in Australian community aged care settings. All incident reports made by community care workers employed by one of the largest community aged care provider organizations in Australia during the period November 1, 2012, to August 8, 2013, were analyzed. A total of 356 reports were analyzed, corresponding to a 7.5% incidence rate per client year. Falls and medication incidents were the most prevalent incident types. Clients receiving high-level care and those who attended day therapy centers had the highest rate of incidents with 14% to 20% of these clients having a reported incident. The incident profile indicates that clients on higher levels of care had higher incident rates. Incident data represent an opportunity to improve client safety in community aged care.

Spray deposition of exfoliated MoS2 flakes as hole transport layer in perovskite-based photovoltaics

We propose the use of solution-processed molybdenum disulfide (MoS2) flakes as hole transport layer (HTL) for metal-organic perovskite solar cells. MoS2 bulk crystals are exfoliated in 2-propanol and deposited on perovskite layers by spray coating. We fabricated cells with glass/FTO/compact-TiO2/mesoporous-TiO2/CH3NH3PbI3/spiro- OMeTAD/Au structure and cells with the same structure but with MoS2 flakes as HTL instead of spiro-OMeTAD, the most widely used HTL. The electrical characterization of the cells with MoS2 as HTL show promising power conversion efficiency -η- of 3.9% with respect to cells with pristine spiro-OMeTAD (η=3.1%). Endurance test on 800-hour shelf life has shown higher stability for the MoS2–based cells (ΔPCE/PCE=-17%) with respect to the doped spiro-OMeTAD-based one (ΔPCE/PCE =-45%). Further improvements are expected with the optimization of the MoS2 deposition process

A new multi-objective model to optimise rail transport scheduler

The sugarcane transport system plays a critical role in the overall performance of Australia’s sugarcane industry. An inefficient sugarcane transport system interrupts the raw sugarcane harvesting process, delays the delivery of sugarcane to the mill, deteriorates the sugar quality, increases the usage of empty bins, and leads to the additional sugarcane production costs. Due to these negative effects, there is an urgent need for an efficient sugarcane transport schedule that should be developed by the rail schedulers. In this study, a multi-objective model using mixed integer programming (MIP) is developed to produce an industry-oriented scheduling optimiser for sugarcane rail transport system. The exact MIP solver (IBM ILOG-CPLEX) is applied to minimise the makespan and the total operating time as multi-objective functions. Moreover, the so-called Siding neighbourhood search (SNS) algorithm is developed and integrated with Sidings Satisfaction Priorities (SSP) and Rail Conflict Elimination (RCE) algorithms to solve the problem in a more efficient way. In implementation, the sugarcane transport system of Kalamia Sugar Mill that is a coastal locality about 1050 km northwest of Brisbane city is investigated as a real case study. Computational experiments indicate that high-quality solutions are obtainable in industry-scale applications.

To ask or not to ask? Investigating workers' flexibility requests and the phenomenon of discontented non-requesters

Flexible working arrangements have attracted growing attention in workplaces across Australia and in many other countries in recent years. This contribution utilises the results of two large Australian employee surveys to analyse who asks for flexibility, why, and with what effects on work-life interference. This analysis is set in the context of Australia’s ‘Right to Request’ (RTR) provisions which, at the time of the study, gave parents of preschool children and those with a disabled child aged up to 18 the RTR flexibility. The analysis also draws on a set of qualitative interviews of those we term ‘discontented non-requesters’ (that is, those who are not content with current arrangements but who do not ask for flexibility) to probe beneath the survey results to consider explanations about why some people do not ask for flexibility despite desiring different working arrangements. We conclude with the implications for policy and regulation.

Project Energise: Using participatory approaches and real time computer prompts to reduce occupational sitting and increase work time physical activity in office workers

Objectives This efficacy study assessed the added impact real time computer prompts had on a participatory approach to reduce occupational sedentary exposure and increase physical activity. Design Quasi-experimental. Methods 57 Australian office workers (mean [SD]; age = 47 [11] years; BMI = 28 [5] kg/m2; 46 men) generated a menu of 20 occupational ‘sit less and move more’ strategies through participatory workshops, and were then tasked with implementing strategies for five months (July–November 2014). During implementation, a sub-sample of workers (n = 24) used a chair sensor/software package (Sitting Pad) that gave real time prompts to interrupt desk sitting. Baseline and intervention sedentary behaviour and physical activity (GENEActiv accelerometer; mean work time percentages), and minutes spent sitting at desks (Sitting Pad; mean total time and longest bout) were compared between non-prompt and prompt workers using a two-way ANOVA. Results Workers spent close to three quarters of their work time sedentary, mostly sitting at desks (mean [SD]; total desk sitting time = 371 [71] min/day; longest bout spent desk sitting = 104 [43] min/day). Intervention effects were four times greater in workers who used real time computer prompts (8% decrease in work time sedentary behaviour and increase in light intensity physical activity; p < 0.01). Respective mean differences between baseline and intervention total time spent sitting at desks, and the longest bout spent desk sitting, were 23 and 32 min/day lower in prompt than in non-prompt workers (p < 0.01). Conclusions In this sample of office workers, real time computer prompts facilitated the impact of a participatory approach on reductions in occupational sedentary exposure, and increases in physical activity.