7,512 research outputs found
Optimising water quality outcomes for complex water resource systems and water grids
As the world progresses, water resources are likely to be subjected to much greater pressures than in the past. Even though the principal water problem revolves around inadequate and uncertain water supplies, water quality management plays an equally important role. Availability of good quality water is paramount to sustainability of human population as well as the environment. Achieving water quality and quantity objectives can be conflicting and becomes more complicated with challenges like, climate change, growing populations and changed land uses. Managing adequate water quality in a reservoir gets complicated by multiple inflows with different water quality levels often resulting in poor water quality. Hence, it is fundamental to approach this issue in a more systematic, comprehensive, and coordinated fashion. Most previous studies related to water resources management focused on water quantity and considered water quality separately. However, this research study focused on considering water quantity and quality objectives simultaneously in a single model to explore and understand the relationship between them in a reservoir system. A case study area was identified in Western Victoria, Australia with water quantity and quality challenges. Taylors Lake of Grampians System in Victoria, Australia receives water from multiple sources of differing quality and quantity and has the abovesaid problems. A combined simulation and optimisation approach was adopted to carry out the analysis. A multi-objective optimisation approach was applied to achieve optimal water availability and quality in the storage. The multi-objective optimisation model included three objective functions which were: water volume and two water quality parameters: salinity and turbidity. Results showed competing nature of water quantity and quality objectives and established the trade-offs. It further showed that it was possible to generate a range of optimal solutions to effectively manage those trade-offs. The trade-off analysis explored and informed that selective harvesting of inflows is effective to improve water quality in storage. However, with strict water quality restriction there is a considerable loss in water volume. The robustness of the optimisation approach used in this study was confirmed through sensitivity and uncertainty analysis. The research work also incorporated various spatio-temporal scenario analyses to systematically articulate long-term and short-term operational planning strategies. Operational decisions around possible harvesting regimes while achieving optimal water quantity and quality and meeting all water demands were established. The climate change analysis revealed that optimal management of water quantity and quality in storage became extremely challenging under future climate projections. The high reduction in storage volume in the future will lead to several challenges such as water supply shortfall and inability to undertake selective harvesting due to reduced water quality levels. In this context, selective harvesting of inflows based on water quality will no longer be an option to manage water quantity and quality optimally in storage. Some significant conclusions of this research work included the establishment of trade-offs between water quality and quantity objectives particular to this configuration of water supply system. The work demonstrated that selective harvesting of inflows will improve the stored water quality, and this finding along with the approach used is a significant contribution to decision makers working within the water sector. The simulation-optimisation approach is very effective in providing a range of optimal solutions, which can be used to make more informed decisions around achieving optimal water quality and quantity in storage. It was further demonstrated that there are range of planning periods, both long-term (>10 years) and short-term (<1 year), all of which offer distinct advantages and provides useful insights, making this an additional key contribution of the work. Importantly, climate change was also considered where it was found that diminishing water resources, particularly to this geographic location, makes it increasingly difficult to optimise both quality and quantity in storage providing further useful insights from this work.Doctor of Philosoph
Leveraging a machine learning based predictive framework to study brain-phenotype relationships
An immense collective effort has been put towards the development of methods forquantifying brain activity and structure. In parallel, a similar effort has focused on collecting experimental data, resulting in ever-growing data banks of complex human in vivo neuroimaging data. Machine learning, a broad set of powerful and effective tools for identifying multivariate relationships in high-dimensional problem spaces, has proven to be a promising approach toward better understanding the relationships between the brain and different phenotypes of interest. However, applied machine learning within a predictive framework for the study of neuroimaging data introduces several domain-specific problems and considerations, leaving the overarching question of how to best structure and run experiments ambiguous. In this work, I cover two explicit pieces of this larger question, the relationship between data representation and predictive performance and a case study on issues related to data collected from disparate sites and cohorts. I then present the Brain Predictability toolbox, a soft- ware package to explicitly codify and make more broadly accessible to researchers the recommended steps in performing a predictive experiment, everything from framing a question to reporting results. This unique perspective ultimately offers recommen- dations, explicit analytical strategies, and example applications for using machine learning to study the brain
High-throughput Tools and Techniques to Investigate Environmental Effects on Aging Behaviors in Caenorhabditis elegans
Aging is modulated by genetic and environmental cues; however, it is difficult to study how these perturbations modulate the aging process in a robust, high-throughput manner. Methods to gather large-scale behavioral data for aging studies are labor-intensive, lack individual-level resolution, or lack precise spatiotemporal environmental control. In addition, tools to analyze large-scale behavioral data sets are difficult to scale, unable to be broadly applied across complex environments, or fail to detect subtle behavioral changes.
In this thesis I develop tools to enable robust, microfluidic culture and behavioral analysis of C. elegans to examine how environmental cues, such as dietary restriction, influence longevity and behavior with age. In Aim 1, I engineer a robust pipeline for the long-term longitudinal culture and behavioral monitoring of C. elegans in aging studies with precise spatiotemporal environmental control. In Aim 2, I develop a flexible deep learning based pipeline for detecting and extracting postural information from large-scale behavioral datasets across heterogeneous environments. In Aim 3, I characterize how the full behavioral repertoire of individuals change with age, along with examining how these age-related behavioral changes are modulated by different dietary restriction regimes. The completion of this thesis provides 1) a new toolset to robustly explore how genetic or environmental effects influence longevity and healthspan, 2) a flexible pipeline for analyzing large-scale behavioral data in C. elegans, and 3) insight into how environmental perturbations influence health through age-related changes in behavior.Ph.D
Glioblastoma and the search for non-hypothesis driven combination therapeutics in academia
Glioblastoma (GBM) remains a cancer of high unmet clinical need. Current standard of care for GBM, consisting of maximal surgical resection, followed by ionisation radiation (IR) plus concomitant and adjuvant temozolomide (TMZ), provides less than 15-month survival benefit. Efforts by conventional drug discovery to improve overall survival have failed to overcome challenges presented by inherent tumor heterogeneity, therapeutic resistance attributed to GBM stem cells, and tumor niches supporting self-renewal. In this review we describe the steps academic researchers are taking to address these limitations in high throughput screening programs to identify novel GBM combinatorial targets. We detail how they are implementing more physiologically relevant phenotypic assays which better recapitulate key areas of disease biology coupled with more focussed libraries of small compounds, such as drug repurposing, target discovery, pharmacologically active and novel, more comprehensive anti-cancer target-annotated compound libraries. Herein, we discuss the rationale for current GBM combination trials and the need for more systematic and transparent strategies for identification, validation and prioritisation of combinations that lead to clinical trials. Finally, we make specific recommendations to the preclinical, small compound screening paradigm that could increase the likelihood of identifying tractable, combinatorial, small molecule inhibitors and better drug targets specific to GBM
Feature Papers in Compounds
This book represents a collection of contributions in the field of the synthesis and characterization of chemical compounds, natural products, chemical reactivity, and computational chemistry. Among its contents, the reader will find high-quality, peer-reviewed research and review articles that were published in the open access journal Compounds by members of the Editorial Board and the authors invited by the Editorial Office and Editor-in-Chief
A Reinforcement Learning-assisted Genetic Programming Algorithm for Team Formation Problem Considering Person-Job Matching
An efficient team is essential for the company to successfully complete new
projects. To solve the team formation problem considering person-job matching
(TFP-PJM), a 0-1 integer programming model is constructed, which considers both
person-job matching and team members' willingness to communicate on team
efficiency, with the person-job matching score calculated using intuitionistic
fuzzy numbers. Then, a reinforcement learning-assisted genetic programming
algorithm (RL-GP) is proposed to enhance the quality of solutions. The RL-GP
adopts the ensemble population strategies. Before the population evolution at
each generation, the agent selects one from four population search modes
according to the information obtained, thus realizing a sound balance of
exploration and exploitation. In addition, surrogate models are used in the
algorithm to evaluate the formation plans generated by individuals, which
speeds up the algorithm learning process. Afterward, a series of comparison
experiments are conducted to verify the overall performance of RL-GP and the
effectiveness of the improved strategies within the algorithm. The
hyper-heuristic rules obtained through efficient learning can be utilized as
decision-making aids when forming project teams. This study reveals the
advantages of reinforcement learning methods, ensemble strategies, and the
surrogate model applied to the GP framework. The diversity and intelligent
selection of search patterns along with fast adaptation evaluation, are
distinct features that enable RL-GP to be deployed in real-world enterprise
environments.Comment: 16 page
A Decision Support System for Economic Viability and Environmental Impact Assessment of Vertical Farms
Vertical farming (VF) is the practice of growing crops or animals using the vertical dimension via multi-tier racks or vertically inclined surfaces. In this thesis, I focus on the emerging industry of plant-specific VF. Vertical plant farming (VPF) is a promising and relatively novel practice that can be conducted in buildings with environmental control and artificial lighting. However, the nascent sector has experienced challenges in economic viability, standardisation, and environmental sustainability. Practitioners and academics call for a comprehensive financial analysis of VPF, but efforts are stifled by a lack of valid and available data.
A review of economic estimation and horticultural software identifies a need for a decision support system (DSS) that facilitates risk-empowered business planning for vertical farmers. This thesis proposes an open-source DSS framework to evaluate business sustainability through financial risk and environmental impact assessments. Data from the literature, alongside lessons learned from industry practitioners, would be centralised in the proposed DSS using imprecise data techniques. These techniques have been applied in engineering but are seldom used in financial forecasting. This could benefit complex sectors which only have scarce data to predict business viability.
To begin the execution of the DSS framework, VPF practitioners were interviewed using a mixed-methods approach. Learnings from over 19 shuttered and operational VPF projects provide insights into the barriers inhibiting scalability and identifying risks to form a risk taxonomy. Labour was the most commonly reported top challenge. Therefore, research was conducted to explore lean principles to improve productivity.
A probabilistic model representing a spectrum of variables and their associated uncertainty was built according to the DSS framework to evaluate the financial risk for VF projects. This enabled flexible computation without precise production or financial data to improve economic estimation accuracy. The model assessed two VPF cases (one in the UK and another in Japan), demonstrating the first risk and uncertainty quantification of VPF business models in the literature. The results highlighted measures to improve economic viability and the viability of the UK and Japan case.
The environmental impact assessment model was developed, allowing VPF operators to evaluate their carbon footprint compared to traditional agriculture using life-cycle assessment. I explore strategies for net-zero carbon production through sensitivity analysis. Renewable energies, especially solar, geothermal, and tidal power, show promise for reducing the carbon emissions of indoor VPF. Results show that renewably-powered VPF can reduce carbon emissions compared to field-based agriculture when considering the land-use change.
The drivers for DSS adoption have been researched, showing a pathway of compliance and design thinking to overcome the ‘problem of implementation’ and enable commercialisation. Further work is suggested to standardise VF equipment, collect benchmarking data, and characterise risks. This work will reduce risk and uncertainty and accelerate the sector’s emergence
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Decarbonizing the electricity sector in Qatar
Limiting global warming to 1.5℃ requires transitioning to low-carbon electricity grids. In Qatar, high and predictable insolation synergetic with demand makes exploiting solar energy particularly attractive to decarbonize the electricity sector. With a hot desert climate, space-cooling drives demand, accounting for nearly half of annual electricity use. This dissertation analyzes a decarbonization pathway by exploiting solar PV generation combined with ice storage for cooling load shifting and battery storage for electric load shifting in a top-down approach by (i) assessing the potential for large-scale deployment, (ii) examining the subsequent problem of distributed energy resources capacity sizing, and (iii) proposing a solution to the arising demand side management problem. A carbon tax is examined to oppose cheap and plentiful natural gas.
The analysis outcomes using a linear program show a strong potential for decarbonizing using PV-enabled solutions. While they cannot displace gas generations, their role is reduced to aid in meeting summer demands. Although buildings are well suited for distributed PV, Qatar is a better fit for utility-scale implementation because of reduced costs and higher output from solar tracking technology, and accessibility for cleaning as soiling on PV is a concern.
Under the current gas price of 60/ton of COâ‚‚ reduces emissions by 60%. Further reduction is difficult due to the misalignment of the summer electricity demand peak with the solar insolation peak, and ice storage cannot outcompete existing gas generation for a seasonal cooling load. Ice storage is fit to utilize the large idle chiller capacity in the shoulder season, particularly in less efficient systems, because an equal tank volume corresponds to a greater electric load shifting. Battery storage becomes economical with a carbon tax above 140/ton of COâ‚‚ carbon tax. However, peak gas generation demand was only lowered by 66%.
Linear models are useful to describe large systems, but they cannot be applied to an individual system. Instead, hybrid models combining models from first principles with data-driven parameters are developed. The distributed-scale capacity sizing problem is formulated in a bi-level optimization. The upper-level decided equipment capacities using particle swarm are passed down to solve the scheduling problem to estimate electricity charges in a mixed-integer linear program with piecewise linearization. The distributed-scale analysis affirmed the suitability of the decarbonization pathway. Buildings with dominant day-time demand, such as commercial buildings, are well positioned to benefit from exploiting distributed PV generation.
Demand-side management for cooling systems becomes essential in transitioning to low-carbon power grids since intermittent renewable generations cannot be dispatched or perfectly predicted. An optimization strategy is developed to schedule and dispatch chiller systems with ice storage. The strategy decomposes the problem into a bi-level formulation solved using the genetic algorithm. The upper level decides the storage dispatch amount, and the lower level solves the scheduling problem at each time step. The penalty function method handles the scheduling problem's constraints, and with penalty factor tuning, premature convergence is eliminated. Compared to commonly used heuristic strategies, optimal control reduced cost by 11-33%. The gains are augmented with a more complex tariff structure like demand charge
Authentic Alignment: Toward an Interpretative Phenomenological Analysis (IPA) informed model of the learning environment in health professions education
It is well established that the goals of education can only be achieved through the constructive alignment of instruction, learning and assessment. There is a gap in research interpreting the lived experiences of stakeholders within the UK learning environment toward understanding the real impact – authenticity – of curricular alignment. This investigation uses a critical realist framework to explore the emergent quality of authenticity as a function of alignment.
This project deals broadly with alignment of anatomy pedagogy within UK undergraduate medical education. The thread of alignment is woven through four aims: 1) to understand the alignment of anatomy within the medical curriculum via the relationships of its stakeholders; 2) to explore the apparent complexity of the learning environment (LE); 3) to generate a critical evaluation of the methodology, Interpretative Phenomenological Analysis as an approach appropriate for realist research in the complex fields of medical and health professions education; 4) to propose a functional, authentic model of the learning environment.
Findings indicate that the complexity and uncertainty inherent in the LE can be reflected in spatiotemporal models. Findings meet the thesis aims, suggesting: 1) the alignment of anatomy within the medical curriculum is complex and forms a multiplicity of perspectives; 2) this complexity is ripe for phenomenological exploration; 3) IPA is particularly suitable for realist research exploring complexity in HPE; 4) Authentic Alignment theory offers a spatiotemporal model of the complex HPE learning environment: the T-icosa
Program and Proceedings: The Nebraska Academy of Sciences 1880-2023. 142th Anniversary Year. One Hundred-Thirty-Third Annual Meeting April 21, 2023. Hybrid Meeting: Nebraska Wesleyan University & Online, Lincoln, Nebraska
AERONAUTICS & SPACE SCIENCE Chairperson(s): Dr. Scott Tarry & Michaela Lucas
HUMANS PAST AND PRESENT Chairperson(s): Phil R. Geib & Allegra Ward
APPLIED SCIENCE & TECHNOLOGY SECTION Chairperson(s): Mary Ettel
BIOLOGY Chairpersons: Lauren Gillespie, Steve Heinisch, and Paul Davis
BIOMEDICAL SCIENCES Chairperson(s): Annemarie Shibata, Kimberly Carlson, Joseph Dolence, Alexis Hobbs, James Fletcher, Paul Denton
CHEM Section Chairperson(s): Nathanael Fackler
EARTH SCIENCES Chairpersons: Irina Filina, Jon Schueth, Ross Dixon, Michael Leite
ENVIRONMENTAL SCIENCE Chairperson: Mark Hammer
PHYSICS Chairperson(s): Dr. Adam Davis
SCIENCE EDUCATION Chairperson: Christine Gustafson
2023 Maiben Lecturer: Jason Bartz
2023 FRIEND OF SCIENCE AWARD TO: Ray Ward and Jim Lewi
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