Evaluating the performance of different media in a horizontal subsurface flow constructed wetland

The treatment efficiency of a wetland system requires a balance between pollutant loading rate and hydraulic retention time (HRT), hydraulic loading rate (HLR) and the suitable substrate to be used. The aim of this study was to investigate the treatment efficiency of horizontal subsurface flow constructed wetland planted with phragmites australis and scirpus maritimus containing three different substrates to treat agricultural wastewater under short term operation. Alum sludge and zeolite were used as substrates and gravel was used as a control for a laboratory-scale horizontal flow constructed wetland (CW) units that were made of high-density Polyethylene. The units were operated under 2, 3 and 4 days of HRTs and at different HLR for each substrate. Each beds received 0.012 m3/d to 0.08 m3/d of synthetic wastewater corresponding to a HLR of 0.035 to 0.243 m/d and a COD loading rate of 0.0148 kg COD (m2.d)-1 to 0.026 kg COD (m2.d)-1. The relationships between the substrate, retention time and removal efficiency, especially of organic matter and nutrient removal were investigated. All units showed relatively stable removal for COD during the entire operational period. The COD removal for all units and HRT were in ranged from 67% to 93%. The zeolite unit achieved significantly higher removal of TN, NH4-N and TSS compared to alum sludge and gravel unit at all HRT. The unit with zeolite was highly effective in removing TN (54 to 96%), NH4-N (50 to 99%) and TSS (91 to 96%) respectively, at 2, 3 and 4 days of HRT. Meanwhile, alum sludge was highly effective in removing phosphate. The removal of phosphate from alum sludge unit was ranged from 94 to 97% for all HRT. Compared to gravel CW unit, zeolite and alum sludge CW were proved to be tolerant to high organic loadings and nutrients, suggesting these substrates as viable options for biological treatment of agricultural wastewater.

Book review : International entrepreneurship in family businesses

J.C. Casillas, F.J. Acedo and A.M. Moreno (2007) International Entrepreneurship in Family Businesses, Edward Elgar, Cheltenham, United Kingdom, ISBN 978 1 845428792

Solving the median shortest path problem in the planning and design of urban transportation networks using a vector labeling algorithm

This paper proposes an alternative algorithm to solve the median shortest path problem (MSPP) in the planning and design of urban transportation networks. The proposed vector labeling algorithm is based on the labeling of each node in terms of a multiple and conflicting vector of objectives which deletes cyclic, infeasible and extreme-dominated paths in the criteria space imposing cyclic break (CB), path cost constraint (PCC) and access cost parameter (ACP) respectively. The output of the algorithm is a set of Pareto optimal paths (POP) with an objective vector from predetermined origin to destination nodes. Thus, this paper formulates an algorithm to identify a non-inferior solution set of POP based on a non-dominated set of objective vectors that leaves the ultimate decision to decision-makers. A numerical experiment is conducted using an artificial transportation network in order to validate and compare results. Sensitivity analysis has shown that the proposed algorithm is more efficient and advantageous over existing solutions in terms of computing execution time and memory space used.

Coupled modelling of hydrodynamics and mass transfer in membrane filtration

This research produced a novel predictive computational model for the water treatment processes of nanofiltration and reverse osmosis. This model combined commercial computational fluid dynamics codes with numerical mass transfer models developed by the candidate to provide a rigorous description of these processes’ hydrodynamic and pollutant removal behaviour.

Animals as disregarded pawns in family violence : exclusionary practices of feminist based refuge policies

Commonly agreed upon is the relationship between family violenceand violence toward nonhuman animals. Workers in the field of family violence also acknowledge that women may delay leaving a violent home due to loyalty to their nonhuman counterparts, and because refuge policies often do not allow them to accompany humans into safe shelter. The recent work of Clifton Flynn has indicated the relationship between nonhuman animals and human animals to be one of responsive interaction, with theoretical analyses most often based upon Goffman’s theory of symbolic interaction. Despite literature indicating the level of harm inflicted upon nonhuman family members in violent homes, and requests from women and children that they accompany them to safe shelter, refuge policies often negate the possibility of this occurring. This article critiques the feminist ideals on which refuge policies are based, and in doing so, argues that justice is denied to nonhuman animals. Their existence in the violent home is maintained by lack of choices available to their human counterpart, and is enforced by feminist ideals, which are ironically based upon equity. Unless feminist principles are challenged, nonhuman family members will continue to be denied justice in violent families where escape is the only option to ensure safety.

Social media in disaster response : Queensland Police Service - public engagement during the 2011 floods

Social Media, particularly Microblogging services, are now being adopted as an additional tool for emergency service agencies to be able to interact with the community at all stages of a disaster. Unfortunately, no standard framework for Social Media adoption for disaster management exists and emergency service agencies are adopting Social Media in an ad-hoc fashion. This paper seeks to provide a general understanding of how Social Media is being used by emergency service agencies during disasters, to better understand how we might develop a standardised framework of adoption. In this study of the 2010/11 Queensland Flood event, Facebook broadcast messages from the Queensland Police Service to the general public, were analysed by genre. Findings show that these Microblogging activities were mostly about information distribution and warning broadcasts and that the strength of Social Media for two-way communication and collaboration with the general public, was under-utilised during this event.

Adoption of social media in Victorian local governments

The use of the Internet and social media tools by Australians has increased significantly over the last five years. Social media tools provide local governments with the opportunity to inform, serve and interact with their constituents on a level not previously possible. This paper uses a mixed method approach to firstly review current use of social media tools by Victorian local governments and secondly interview elected officials and administrators of four Victorian local councils about barriers to the adoption of social media tools. The results show that while 59 Victorian local governments (74%) are utilizing at least one social media tool, there are 20 councils (25%) that still do not utilize social media tools. The interviews indicate that the main barriers hindering social media implementations are: uncertainty, fear of risk, lack of knowledge and experience, lack of resources, lack of trust and, the culture of government. The main contribution of this study is a review of the current level of adoption of social media tools by Victorian local governments and identifies a number of barriers that prevent local government from fully utilizing the advantages of social media tools. Currently most Victorian local governments use social media to disseminate information.

Social media in the classroom : a simple yet complex hybrid environment for students

This article reports on part of the author’s PhD action research study. It examines the complexity of features that social media and Web 2.0 offer when combined with face-to-face teaching and learning. Action research was used to help redesign the learning programs of thirteen Middle Years classes over an eighteen month period. These learning programs took advantage of the unique communicative methods offered by social media and provided spaces such as blogs, groups and discussion forums. Students developed their own identity when working online, made online friends, left comments for peers and uploaded content which included publishing, peer reviewing and self assessment. The research highlighted the simplicity in the creation and exchange of user-generated content and interaction while identifying a complex depth behind such interaction. Designing learning programs using social media enabled the students to be active and valued participants in the learning process and a ‘hybrid’ learning environment