Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor

This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe(2+) dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation.

A study and a directory of energy consumption data sets of buildings

Energy consumption data are required to perform analysis, modelling, evaluation, and optimisation of energy usage in buildings. While a variety of energy consumption data sets have been examined and reported in the literature, there is a lack of a comprehensive categorisation and analysis of the available data sets. In this study, an overview of energy consumption data of buildings is provided. Three common strategies for generating energy consumption data, i.e., measurement, survey, and simulation, are described. A number of important characteristics pertaining to each strategy and the resulting data sets are discussed. In addition, a directory of energy consumption data sets of buildings is developed. The data sets are collected from either published papers or energy related organisations. The main contributions of this study include establishing a resource pertaining to energy consumption data sets and providing information related to the characteristics and availability of the respective data sets; therefore facilitating and promoting research activities in energy consumption data analysis.

Damage identification scheme based on compressive sensing

Civil infrastructures are critical to every nation, due to their substantial investment, long service period, and enormous negative impacts after failure. However, they inevitably deteriorate during their service lives. Therefore, methods capable of assessing conditions and identifying damage in a structure timely and accurately have drawn increasing attention. Recently, compressive sensing (CS), a significant breakthrough in signal processing, has been proposed to capture and represent compressible signals at a rate significantly below the traditional Nyquist rate. Due to its sound theoretical background and notable influence, this methodology has been successfully applied in many research areas. In order to explore its application in structural damage identification, a new CS-based damage identification scheme is proposed in this paper, by regarding damage identification problems as pattern classification problems. The time domain structural responses are transferred to the frequency domain as sparse representation, and then the numerical simulated data under various damage scenarios will be used to train a feature matrix as input information. This matrix can be used for damage identification through an optimization process. This will be one of the first few applications of this advanced technique to structural engineering areas. In order to demonstrate its effectiveness, numerical simulation results on a complex pipe soil interaction model are used to train the parameters and then to identify the simulated pipe degradation damage and free-spanning damage. To further demonstrate the method, vibration tests of a steel pipe laid on the ground are carried out. The measured acceleration time histories are used for damage identification. Both numerical and experimental verification results confirm that the proposed damage identification scheme will be a promising tool for structural health monitoring.

Nonlinear large deformation dynamic analysis of electroactive polymer actuators

Electroactive polymers have attracted considerable attention in recent years due to their sensing and actuating properties which make them a material of choice for a wide range of applications including sensors, biomimetic robots, and biomedical micro devices. This paper presents an effective modeling strategy for nonlinear large deformation (small strains and moderate rotations) dynamic analysis of polymer actuators. Considering that the complicated electro-chemo-mechanical dynamics of these actuators is a drawback for their application in functional devices, establishing a mathematical model which can effectively predict the actuator's dynamic behavior can be of paramount importance. To effectively predict the actuator's dynamic behavior, a comprehensive mathematical model is proposed correlating the input voltage and the output bending displacement of polymer actuators. The proposed model, which is based on the rigid finite element (RFE) method, consists of two parts, namely electrical and mechanical models. The former is comprised of a ladder network of discrete resistive-capacitive components similar to the network used to model transmission lines, while the latter describes the actuator as a system of rigid links connected by spring-damping elements (sdes). Both electrical and mechanical components are validated through experimental results.

Thermal comfort of multiple user groups in indoor aquatic centres

Aquatic centres are popular recreational facilities in Australia and other developed countries. These buildings have experienced exponential demand over the past few decades. The growing desire for better indoor environmental quality in aquatic centres has resulted in a marked increase in energy consumption in this sector. With the existence of multiple user groups, achieving thermal comfort has always been challenging. Even though several thermal comfort studies are conducted in other building types, such studies are very limited with respect to aquatic centres. This paper analyses the thermal comfort conditions of various user groups in seven aquatic centres in Australia. Comfort measurements are performed through monitoring environmental parameters and surveying swimmers, staff and spectators. The results revealed the variation of air temperatures among the buildings, resulting in high level of thermal discomfort for the spectators and staff in some of the buildings. The thermal sensation of the staff and spectators had good correlation with the indoor temperatures and PMVs. Altering temperature settings according to the seasons will help to improve the comfort with respect to the adaptation and expectation of the occupants.

Reducing the effect of wave dispersion in a timber pole based on transversely isotropic material modelling

Round timbers are used for telecommunication and power distribution networks, jetties, piles, short span bridges etc. To assess the condition of these cylindrical shape timber structures, bulk and elementary wave theory are usually used. Even though guided wave can represents the actual wave behaviour, a great deal complexity exists to model stress wave propagation within an orthotropic media, such as timber. In this paper, timber is modelled as transversely isotropic material without compromising the accuracy to a great extent. Dispersion curves and mode shapes are used to propose an experimental set up in terms of the input frequency and bandwidth of the signal, the orientation of the sensor and the distance between the sensors in order to reduce the effect of the dispersion in the output signal. Some example based on the simulated signal is also discussed to evaluate the proposed experimental set up.

A method for comprehensively assessing economic trade-offs of new irrigation developments

To meet the anticipated increase in global demand for food and fibre products, large areas of land around the world are being cleared and infrastructure constructed to enable irrigation, referred to herein as ‘greenfield irrigation’. One of the challenges in assessing the profitability of a greenfield irrigation development is understanding the impact of variability in climate and water availability and the trade-offs with scheme size, cost and the sensitivity of crop yield to water stress. For example, is it more profitable to irrigate a small area of land most years or a large area once every few years? And, is it more profitable to partially or fully water the crop? This paper presents a new method for efficiently linking a river system model and an agricultural production model to explore the financial trade-offs of different management choices, thereby enabling the optimal scheme area and most appropriate level of farmer risk to be identified. The method is demonstrated for a hypothetical but plausible greenfield irrigation development based around a large dam in the Flinders catchment, northern Australia. It was found that a dam and irrigation development paid for and operated by the same entity is not, under the conditions examined in this analysis, economically sustainable. The method could also be used to explore the impact of different management strategies on the agricultural production and profitability of existing irrigation schemes within a whole of river system context.

Impact of integrating disaster risk reduction philosophies into infrastructure reconstruction projects in Sri Lanka

Major impacts on infrastructures due to natural and man-made hazards could result in secondary and additional impacts, compounding the problem for those communities already affected by the hazard. Integration of disaster risk reduction (DRR) philosophies into infrastructure projects has been an important solution to mitigate and prevent such disaster risks, as well as for a speedy recovery after disasters. Vulnerability reduction is defined by the research community as an enabler which facilitates the process of DRR. However, there is a research need to identify the most beneficial DRR strategies that would result in vulnerability reduction in an effective way. As part of this main aim, this paper seeks to explore the nature of various vulnerabilities within infrastructure reconstruction projects and their respective communities and to evaluate the DRR practises within these projects. Finally the paper attempts to map the effects of integration of DRR into infrastructure reconstruction on vulnerability reduction of infrastructure reconstruction projects and the communities which benefited from such projects. This study adopts the case study approach and the paper is entirely based on data collated from semi-structured interviews and a questionnaire survey conducted within one case study (a water supply and sanitation reconstruction project) in Sri Lanka and expert interviews conducted in Sri Lanka and the United Kingdom. Results reveal that emergency preparedness strategies are the most important group of DRR strategies, while physical/technical strategies are also very important. However, none of the emergency preparedness strategies are satisfactorily implemented, while most of the physical/technical strategies are adequately implemented.

Relationships between civil engineering students’ learning approaches and their perception of curriculum and teaching quality

BACKGROUND: Deakin University graduated its first cohort from four-year undergraduate civil engineering course/program in 2012. The internal annual Course Experience Survey, which has been running annually since 2012, targets to identify the graduating students’ learning approaches and students’ perceptions of the curriculum and teaching quality. Literature suggests that students’ learning outcomes can be achieved more efficiently when the students’ perceptions of curriculum and teaching quality are closely aligned with their learning approaches. Where the students’ approaches to learning and their perception of curriculum and teaching quality are mismatched, a series of frustrations can result for the students that may not only negatively impact their learning achievement but also their learning experience.
PURPOSE OR GOAL: This study explores the relationships between students’ learning approaches and their perception of curriculum and teaching quality in an undergraduate civil engineering program/course. This will help understand whether the curriculum and teaching quality provided by the university have actually accommodated ‘all’ enrolled students in the similar way.
APPROACH: To uncover these relationships, this study adopts questionnaire survey approach to collect response data over a two year period by asking students about their perception through a series of statements. 5-point Likert-scale questionnaire survey (strongly disagree, disagree, neutral, agree, strongly agree) is developed and responses are collected. The responses are then statistically analysed in order to uncover the relationships between students’ learning approaches and their perception of curriculum and teaching quality provided by the university.
DISCUSSION: Deep learners and surface learners had a statistically different perception of curriculum and teaching quality. These results contradict the assumption that learners will have uniform preferences on the curriculum, teaching quality and the way they deal with the demands of specific learning situations. Anecdotal belief that ‘good course/program curriculum and good teaching approaches are good for all students and vice-versa’ may not be strictly true for contemporary heterogeneous student cohorts.
RECOMMENDATIONS/IMPLICATIONS/CONCLUSION: This finding highlights the challenge for curriculum designer to design appropriate course curriculum and teaching staff to implement efficient teaching strategies that benefit both surface and deep learners, who are usually enrolled together. It may be beneficial to provide diversity and flexibility in the curriculum and teaching approaches (rather than a uniform approach). However, this may demand additional resources and may also be questioned for equity and consistency of education. It is also important to note that due to relatively a small dataset, these results may not be generalised.

Framework for undergraduate engineering management studies

The importance of management to the long-term careers of practicing professional engineers has long been recognized. Undergraduate engineering education should therefore provide an exposure to the management skills required by engineers in professional practice. For the rational and effective design of undergraduate engineering management studies, it is essential to understand the nature of engineering management and to identify those management skills identified as important by practicing professional engineers. Through an investigation of the recent literature, the management skills considered important by engineering stakeholder groups are identified and ranked. This information is supplemented by recent surveys conducted by the author of stakeholders in Australia, including academic staff, mature age undergraduate students, and recent graduates of the engineering programs at Deakin University in Australia. Based on an examination of the literature and original research, a framework of ranked classified management skills is proposed. Broadly, the ranking framework is generic professional skills first, followed by general management skills and technical discipline specific management skills, followed by other professional discipline skills and theoretical skills.

Damage identification of civil infrastructure in the time domain using FEM calibrated ARMAX model

Due to environmental loads, mechanical damages, structural aging and human factors, civil infrastructure inevitably deteriorate during their service lives. Since their damage may claim human lives and cause significant economic losses, how to identify damages and assess structural conditions timely and accurately has drawn increasingly more attentions from structural engineering community worldwide. In this study, a fast and sensitive time domain damage identification method will be developed. First, a high quality finite element model is built and the structural responses are simulated under different damage scenarios. Based on the simulated data, an Auto Regressive Moving Average Exogenous (ARMAX) model is then developed and calibrated. The calibrated ARMAX model can be used to identify damage in different scenarios through model updating process using clonal selection algorithm (CSA). The identification results demonstrate the performance of the proposed methodology, which has the potential to be used for damage identification in practices.