An Overview of System Strength Challenges in Australia’s National Electricity Market Grid

The national electricity market (NEM) of Australia is reforming via the rapid uptake of variable renewable energy (VRE) integration concurrent with the retirement of conventional synchronous generation. System strength has emerged as a prominent challenge and constraint to power system stability and ongoing grid connection of VRE such as solar and wind. In order to facilitate decarbonization pathways, Australia is the first country to evolve system strength and inertia frameworks and assessment methods to accommodate energy transition barriers, and other parts of the world are now beginning to follow the same approach. With the evolvement of the system strength framework as a new trending strategy to break the transition barriers raised by renewable energy project development and grid connection studies, this paper provides a high-level overview of system strength, covering such fundamental principles as its definition, attributes, and manifestations, as well as industry commentary, cutting-edge technologies and works currently underway for the delivery of a secure and reliable electricity system with the rapid integration of inverter-based resources (IBRs) in the NEM grid. The intent of this study is to provide a comprehensive reference on the engineering practices of the system strength challenge along with complementary technical, regulatory, and industry perspectives.

Improving bioinformatics software quality through incorporation of software engineering practices

Background Bioinformatics software is developed for collecting, analyzing, integrating, and interpreting life science datasets that are often enormous. Bioinformatics engineers often lack the software engineering skills necessary for developing robust, maintainable, reusable software. This study presents review and discussion of the findings and efforts made to improve the quality of bioinformatics software. Methodology A systematic review was conducted of related literature that identifies core software engineering concepts for improving bioinformatics software development: requirements gathering, documentation, testing, and integration. The findings are presented with the aim of illuminating trends within the research that could lead to viable solutions to the struggles faced by bioinformatics engineers when developing scientific software. Results The findings suggest that bioinformatics engineers could significantly benefit from the incorporation of software engineering principles into their development efforts. This leads to suggestion of both cultural changes within bioinformatics research communities as well as adoption of software engineering disciplines into the formal education of bioinformatics engineers. Open management of scientific bioinformatics development projects can result in improved software quality through collaboration amongst both bioinformatics engineers and software engineers. Conclusions While strides have been made both in identification and solution of issues of particular import to bioinformatics software development, there is still room for improvement in terms of shifts in both the formal education of bioinformatics engineers as well as the culture and approaches of managing scientific bioinformatics research and development efforts.

Failure Mechanism of Gob-Side Roadway under Overlying Coal Pillar Multiseam Mining

Roadway deformation and rock burst are the two key challenges faced by the safe operation of coal mines. Aiming at the issue of large deformation of the gob-side roadway under coal pillars in multiseam mining, this study has considered the case of the 8308 panel of Xinzhouyao coal mine in China. Based upon a combination of theoretical analysis, numerical simulations, and engineering practices, the mechanical model of “stress and deformation quantitative calculation of gob-side roadway under overlying coal pillars” was established in this study. The analytical solutions of the vertical stress distribution and the plastic zone of the gob-side roadway under overlying coal pillars were obtained. Finally, the accuracy of the mechanical model was verified using numerical simulations. The results showed that the coal pillar, upright above the gob-side roadway, and the cantilever roof around the gob-side roadway were the main factors leading to stress concentration and deformation around the gob-side roadway. For the particular cases considered in this study, the peak stress of the gob-side roadway could reach 1.8 times of the self-weight stress of overlying strata. The rates of the contribution of the gob-side roadway’s overlying pillar and the cantilever roof around the gob-side roadway to peak stress were 78.3% and 16%, respectively. The obtained results have an essential reference significance for stress calculations and rock burst prevention design of gob-side roadway under overlying coal pillars in multiseam mining.

Designing for others: the roles of narrative and empathy in supporting girls’ engineering engagement

Purpose Science museums provide a context for developing and testing engineering activities that support visitors in creating personally meaningful objects. This study aims to propose that narrative design elements in such engineering activities can foster empathy to support engineering engagement among girls ages 7–14. Design/methodology/approach Taking a constructionist approach to engineering design, the authors present results from an observational study (n = 202 girls) of engineering activities across three museums that were designed to foster girls’ engineering engagement by integrating narrative elements aimed to foster empathy in activities. Using quantitative counts from observation protocols, the authors conducted statistical analyses to explore relationships between narrative, engineering and empathy. Findings Linear regression demonstrated a statistically significant relationship between empathy and increased numbers of engineering practices within museum activities. Additionally, this led us to explore the impacts the potential narrative design elements may have on designing for empathy – multiple linear regressions found both narrative and empathy to be independently associated with engineering practices. Overall, the authors found that using narrative to design activities to elicit empathy resulted in girls demonstrating more engineering practices. Originality/value The authors offer design ideas to foster aspects of empathy, including user-centered design, perspective-taking, familiarity and desire to help.

Exploring relationships between playspaces, pedagogy, and preschoolers’ play-based science and engineering practices

This manuscript reports the results of a research study exploring the ways in which physical space and teacher pedagogy are related to preschoolers’ engagement with science and engineering practices while at play. Using the Science and Engineering Practices Observation Protocol (SciEPOP), researchers captured children’s engagement with the eight science and engineering practices identified in the Next Generation Science Standards (NGSS). This study explores relationships between specific playspaces, materials, and pedagogical strategies, and children’s patterns of engagement with particular science and engineering practices during free play. There are notable differences in the spaces, materials, and pedagogies children encounter across the four participating preschools, and these differences suggest significant gaps in children’s opportunities to engage in and deepen their enactment of science and engineering practices. The authors present evidence in support of adaptive, personalized strategies for deepening children’s engagement with science through play, and raise questions about equity in early science learning environments that have implications both nationally and internationally for science education research, practice, and policy.

Accurate Live Interfacial Tension for Improved Reservoir Engineering Practices

Current reservoir simulators use interfacial tension (IFT) values derived from dead oil measurements at ambient conditions or predicted from literature correlations. IFT is highly dependent on temperature, pressure and fluid composition. Therefore, knowledge of the IFT value at reservoir conditions is essential for accurate reservoir fluid characterization. This study compares IFT values from dead and live oil measurements and the results of literature predicted values, thereby clearly showing the weakness of existing correlations when trying to predict crude oil IFT. A total of ten live oils was sampled for this study. Using the pendent drop technique, IFT was measured for each oil at different conditions: in the under-saturated region at reservoir pressure and temperature, in the saturated region at reservoir temperature, and for dead oil at ambient conditions. Basic PVT properties such as gas to oil ratio (GOR), gas and liquid composition, density, viscosity and molecular weight were also measured. The bubble point for each oil was identified to define the pressure step in the saturated region for extra IFT measurement. The equilibrium IFT values for the live oils were generally higher than for the corresponding dead oils. For oils where this general trend was not observed, contaminations were found in the crude samples. The use of current literature correlations does not allow to predict correct reservoir IFT. Therefore, this study provides accurate live IFT values for a variety of reservoir fluids and conditions in combination with live oil properties, highly beneficial to reservoir engineers, allowing better oil production planning.

Investigation of the Fatigue Stress of Orthotropic Steel Decks Based on an Arch Bridge with the Application of the Arlequin Method

Orthotropic steel decks are widely used in the construction of steel bridges. Although there are many fatigue-evaluation methods stipulated by codes, unexpected fatigue cracks are still detected in some bridges. To justify whether the local finite element model commonly used in fatigue investigations on orthotropic decks can correctly instruct engineering practices, the Arlequin framework is applied in this paper to determine the full fatigue stress under traffic loads. The convergence on and validity of this application for orthotropic decks are checked. Results show that the Arlequin model for deck-fatigue analysis established in this paper tends to be an efficient method for complete fatigue stress acquisition, whereby the vulnerable sites of orthotropic steel decks under traffic loads are defined. Vehicles near the flexible components, such as hangers or cables, can have adverse effects on the fatigue durability of decks. Additionally, the total number of vehicles and their arrangement concentration also affect fatigue performance. Complex traffic conditions cannot be fully loaded in local models. Regardless of the gross bridge mechanics and deck deformation, the fatigue stress range is underestimated by about 30–40%. Such a difference in fatigue assessment seems to explain the premature cracks observed in orthotropic steel decks.

Airport, Docks & Harbours Engineering

This book has been prepared keeping in view the experience in the implementation of Docks, Harbour and Airport Engineering on engineering concepts which are applied in field of Water and Air Transportation Engineering. Diverse knowledge of Docks, Harbour and Airport engineering practices applied to real life problems. The students will learn to understand the theoretical and practical aspects of Docks, Harbour and Airport engineering along with the design and management applications.