Stabilization of experimental bioretention basins during intermittent wetting and drying

Stormwater bioretention basins are subjected to spontaneous intermittent wetting and drying, unlike water treatment filter systems that are subjected to continuous feed. Drinking water filters when constructed new or after back-wash, are subjected to a phase of stabilization. Experiments show that bioretention basins are similarly impacted by intermittent wetting and drying. The common parameter monitored in the stabilisation of filters is the concentration of total solids in the outflow. Filter media in bioretention basins however, consists of a mix of particulate organic matter and fine sand. Organic carbon and solids are therefore needed to be monitored. Four Perspex bioretention filter columns of 94 mm (ID) were packed with a filter layer (800 mm), transition layer and a gravel layer and operated with synthetic stormwater in the laboratory. The filter layer contained 8% organic material by weight. A free board of 350 mm provided detention storage and head to facilitate infiltration. Synthetic stormwater was prepared by adding NH4NO3 (ammonium nitrate) and C2H5NO2 (glycine) and a mixture of kaolinite and montmorillonite clay, to tapwater. The columns were fed with synthetic stormwater with different Antecedent Dry Days (ADD) (0 – 25 day) and constant inflow concentration (2 ppm: nitrate-nitrogen, 1.5 ppm: ammonium-nitrogen, 2.5 ppm: organic-nitrogen 100 ppm: total suspended solids and 7 ppm: organic carbon) at a feed rate of 100mL.min (85.7cm/h). Samples were collected from the outflow at different time intervals between 2 – 150 min from the start of outflow and were tested for Total Suspended Solids (TSS) and Total Organic Carbon (TOC). Both TSS and TOC concentrations in the outflow were observed to be much higher than the concentration of both the parameters in the inflow during the stabilisation period indicating a phase of wash-off (first flush) which lasted for approximately 30 min for both parameters at the beginning of each storm event. The wash-off of TSS and TOC were found to be highly variable depending on the age of the filter and the number of antecedent dry days. The duration of stabilisation phase in the experiments is significant compared with many of the stormwater events. A computational analysis on total mass of each pollutant further affirmed the significance of the first flush of an event on removal of these pollutants. Therefore, the kinetics of the first flush in the stabilisation phase needs to be considered in the performance analysis of the systems.

Knowledge integration within innovation process : a technopreneurial perspective

Knowledge Integration (KI) is one of the major aspects driving innovation within an organisation. In this paper, we attempt to develop a better understanding of responses to the challenges of knowledge integration within the innovation process in technology-based firms. Using four technology-based Australian firms, we investigated how knowledge integration may be managed within the context of innovation in technology firms. Previous research highlights the role of four KI tasks that affect the innovation capability within technology-oriented firms, namely team building capability, capturing tacit knowledge, role of Knowledge Management (KM) systems and technological systemic integration. Our findings indicate that in addition to these four tasks, a strategic approach to integrating knowledge for innovation, as well as leadership and management, are essential to achieving effective KI across multiple levels of engagement. Our findings also offer practical insights into how knowledge can be integrated within innovation process, with specific implications for managers.

Effect of temperature and moisture on high pressure lipid/oil extraction from microalgae

Commercially viable carbon–neutral biodiesel production from microalgae has potential for replacing depleting petroleum diesel. The process of biodiesel production from microalgae involves harvesting, drying and extraction of lipids which are energy- and cost-intensive processes. The development of effective large-scale lipid extraction processes which overcome the complexity of microalgae cell structure is considered one of the most vital requirements for commercial production. Thus the aim of this work was to investigate suitable extraction methods with optimised conditions to progress opportunities for sustainable microalgal biodiesel production. In this study, the green microalgal species consortium, Tarong polyculture was used to investigate lipid extraction with hexane (solvent) under high pressure and variable temperature and biomass moisture conditions using an Accelerated Solvent Extraction (ASE) method. The performance of high pressure solvent extraction was examined over a range of different process and sample conditions (dry biomass to water ratios (DBWRs): 100%, 75%, 50% and 25% and temperatures from 70 to 120 ºC, process time 5–15 min). Maximum total lipid yields were achieved at 50% and 75% sample dryness at temperatures of 90–120 ºC. We show that individual fatty acids (Palmitic acid C16:0; Stearic acid C18:0; Oleic acid C18:1; Linolenic acid C18:3) extraction optima are influenced by temperature and sample dryness, consequently affecting microalgal biodiesel quality parameters. Higher heating values and kinematic viscosity were compliant with biodiesel quality standards under all extraction conditions used. Our results indicate that biodiesel quality can be positively manipulated by selecting process extraction conditions that favour extraction of saturated and mono-unsaturated fatty acids over optimal extraction conditions for polyunsaturated fatty acids, yielding positive effects on cetane number and iodine values. Exceeding biodiesel standards for these two parameters opens blending opportunities with biodiesels that fall outside the minimal cetane and maximal iodine values.

Proceedings of the Third International Workshop on Theory and Applications of Process Visualization

This is the third TAProViz workshop being run at BPM. The intention this year is to consolidate on the results of the previous successful workshops by further developing this important topic, identifying the key research topics of interest to the BPM visualization community. We note this year the continuing interest in the visualisation of process mining data and resultant process models. More info at: http://wst.univie.ac.at/topics/taproviz14/

“My hands are plunged in oranges”…: an experiential account of a working process

This presentation incorporated the live performance throughout, by the author, of movement from “The All Weather Project” by Liz Roche. Movement sections are indicated by italics. “I am going to start by dancing for you… Movement: Live performance of solo approximately 10 minutes in duration This is the introduction... Through my PhD research, I am examining the choreographic process from the perspective of the independent contemporary dancer, through embodying this role as a researcher/participant. My methodological frameworks, which utilise video documentation and journal writing, could be characterised as ethnographic, multi-modal embodied theorising, leading to “multi-dimensional theorising” (I adopt this term from Susan Melrose). In this way, I am unwinding the embodied practice of dancing, through the co-existent layers of experience, towards forming a theoretical understanding of the issues that arise for the dancer. The issues that I have identified as relevant to my research are those relating to the dancer’s ‘moving identity’ or way of moving, as a mutable and adaptable form that must alter and re-adjust to each different choreographic engram or movement vocabulary, that she/he encounters. I am examining this interplay between stability and change. I also reflect on the impact of destabilisation and flux on the dancer’s identity in a wider sense, as she/he relates outwardly to signifying factors within the social strata. Today I am going to bring you through a reflection on the working process of a dance piece as experienced from the inside. By doing so, I hope to capture and elucidate the multi-dimensional layers which existed for me within this process. Through displaying these fragments together, I endeavour to invoke the ‘totality’ of the experience...

Numerical simulation of micro-scale morphological changes of plant food materials during drying - a meshfree approach

This thesis developed a high preforming alternative numerical technique to investigate microscale morphological changes of plant food materials during drying. The technique is based on a novel meshfree method, and is more capable of modeling large deformations of multiphase problem domains, when compared with conventional grid-based numerical modeling techniques. The developed cellular model can effectively replicate dried tissue morphological changes such as shrinkage and cell wall wrinkling, as influenced by moisture reduction and turgor loss.