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Applications of Multinutrient Fertilizers to Improve Mature Mixed Forage Stands in Northern Alberta
No full textThis thesis examines the efficacy of multinutrient fertilizer products in increasing biomass yield, plant nutrient uptake, and residual soil nutrients of mature mixed forage stands. Three sites were established in Northern Alberta: one near Breton and two near Beaumont. The study was conducted for three years, from 2021 to 2023. Eight treatments were applied: an unfertilized control, three nutrient exclusion treatments (removing nitrogen, phosphorus, and sulphur from the blends), and four “complete” treatments containing nitrogen, phosphorus, potassium, and sulphur. Three of the complete treatments included multinutrient fertilizer products, while the fourth was a blend of conventional fertilizers. One of the complete multinutrient fertilizer treatments contained exclusively sulphate-sulphur, one contained equal portions of sulphate-sulphur and elemental sulphur, and one contained exclusively elemental sulphur.
While there were forage biomass yield responses to added fertilizer over the unfertilized check and nutrient exclusion treatments, there were no yield differences found between the complete fertilizer treatments. Further, the sites were largely unresponsive to individual additions of nitrogen, phosphorus, potassium, or sulphur. The experiment year, representing a range of moisture and temperature conditions over the three-year duration of the experiment, tended to be more predictive of forage biomass yield than fertilizer treatment.
Plant nutrient uptake and residual soil nutrients responded in a fashion similar to biomass yield, with the year of the experiment having a strong influence on these factors and few statistically significant differences between complete fertilizer treatments.
Elemental sulphur has been extensively studied on the Canadian prairies, and it has generally been thought to oxidize too slowly for annual crops in this relatively cool and dry
climate. Surface applying elemental sulphur to perennial crops is likely the best fit for elemental sulphur, because of the increased weathering and dispersion compared to subsurface banding applications and the longer timeline of sulphur uptake of perennial crops. Additionally, new formulations of elemental sulphur have smaller particle sizes than those of the past, which should also facilitate more rapid oxidation. Through the results of this project, it was discovered that the sites in this study were not sulphur responsive. Therefore, little could be determined about the oxidation rate and subsequent plant uptake of the elemental sulphur products in this project.
While the addition of fertilizer did, in general, increase forage biomass yields, fertilizer marketing claims of enhanced efficiency or greater nutrient uptake of multinutrient fertilizer products than conventional fertilizer blends could not be supported by this study. Repeating the work on sites with a greater proportion of legumes, or using higher nitrogen rates on predominantly grass stands, may be beneficial. Future work examining feed quality in greater detail in response to these fertilizer products may produce interesting results, as well
Enhancing the Observability of Microservices Using Anomaly Detection and Root Cause Localization With Distributed Traces and Profiling Metrics
Get PDFFuture microservice systems demand enhanced observability to support efficient anomaly detection and root cause localization, especially as these systems scale. This thesis investigates methods for advancing anomaly detection and root cause localization in microservices using multi-source observability data, including distributed traces and profiling metrics. Existing approaches either focus on limited single-source metrics or rely on assumptions about data and services relationships that do not hold in dynamic, real-world systems. These limitations hinder the accuracy of root cause analysis, particularly in complex scenarios where issues propagate across interconnected services.
To address these challenges, this thesis introduces three novel methods. First, it presents ServiceAnomaly, an anomaly detection approach that constructs a Context Propagation Graph (CPG) using distributed traces and profiling metrics to model expected system behavior, enabling the detection and analysis of both structural and behavioral deviations in system performance. Second, it proposes an unsupervised root cause localization method that utilizes critical path analysis in combination with Graph Neural Networks (GNNs), allowing for precise anomaly detection and root cause identification in complex microservice architectures. Third, CARE (Context-Aware Root Cause Identification), a contextual root cause localization approach, integrates social network analysis techniques to investigate anomaly propagation paths, emphasizing the significance of service communities, execution paths, and individual services. CARE offers a new level of observability by contextualizing root cause analysis with a weighted spectrum that considers various propagation pathways in the service network.
These contributions aim to enhance the robustness and scalability of microservice systems by providing a comprehensive framework for anomaly detection and root cause localization. The proposed methods have been rigorously evaluated on both simulated and real-world datasets, demonstrating significant improvements in the detection and localization of complex, cascading anomalies in distributed microservice environments
Examining Known and Novel Hypotheses Related to Children’s Letter Naming Knowledge
No full textThis study explored early literacy skill development, specifically letter knowledge, and compared several existing hypotheses related to why children learn some alphabet letters earlier than other letters. We sought to determine whether letter names, letter sounds, or structural characteristics provide some advantage that could inform instruction and remediation where needed. While past research highlights phonological awareness and letter knowledge as predictors of reading success, gaps remain in understanding how distinctive visual features of letters influence letter identification. By investigating letter knowledge with a sample of children ages four- to six-years old, these results span across the years children are learning conventional reading. Using mixed effect logistic regression, this study found that the letters in a child’s own name, alphabet letter order of instruction, a letter’s position in the alphabet, uppercase and lowercase similarity, and visually distinctive features were the variables that individually supported a greater likelihood of letter identification accuracy. This suggests that there is not one single element that seems to aid in children’s letter knowledge development, but rather, it is expedited with the synergy of several hypothesized factors. We conclude that these main elements, associated with the greatest likelihood of children knowing the letters of alphabet, ought to be carefully considered when creating instructional tools or for interventions targeting letter knowledge development. Future research may consider evaluating the effectiveness of targeted letter knowledge instruction or remediation that integrates considerations related to lowercase letter knowledge, letter sound knowledge, and letters that are closely similar in upper- and lowercase with children that demonstrate typical or atypical language and literacy development while leveraging eye-tracking technology to further investigate the role of visually distinctive features in children’s letter knowledge development
Insight into government, March 7, 2025
No full textAlberta's independent newsletter on government & politics
Dual cannibalization of energy prices and carbon credits in Alberta’s wind energy fleet
No full textAlberta's electricity market has undergone significant greenhouse gas emissions reductions between 2014 and 2023 as it transitioned from coal to natural gas, and had an increased penetration of renewable energy in the market. Wind energy in particular has played an important role in Alberta's transition, but there exist challenges with maintaining wind generator revenue amid decarbonization. This research examines a dual cannibalization effect where an increase in wind energy in Alberta has led to a decrease in wind's average market capture price, and concurrently the carbon offset value available to wind energy generators is poised to decline as the grid continues to decarbonize. To examine these phenomena, this study uses 10 years of historical Alberta electricity market data to develop a counterfactual analysis quantifying the emissions displaced by wind energy. The study examines an alternative offset valuation based on displaced emissions, which yielded an average premium of 4 CAD/MWh over historical offset values. However, this premium diminished to 0 CAD/MWh as the marginal generating fleet decarbonized.
A second counterfactual analysis determined a nearly linear relationship between output increases and revenue increases from wind turbine retrofitting as a mitigation strategy to market price cannibalization. If more wind farms were to apply the modeled retrofit, it would result in diminishing returns in the value of the retrofit as the increase in energy sales was not enough to counterbalance price erosion in the market.
In addition to examining historical data, a forecast model was developed using Aurora software to examine potential wind energy market price erosion into the future. Current carbon pricing policy in Alberta suggests wind energy capacity could grow to as much as 24.3 GW, contributing up to 47 percent of the total energy generation in 2030. Without the support of carbon pricing however, the model forecast 84 percent less new wind capacity and 2030 emissions increased by 2.5 times compared to the scenario following current carbon pricing policies, showing wind energy's reliance on carbon credits.
Overall, the results from this thesis suggest that the current market design will pose challenges to the financial subsidy of wind energy as there is a persistent capture price discount-induced revenue deficit for wind generators
Improving water-related stress tolerance in alfalfa through the down-regulation and genome editing-mediated knockout of stress-responsive genes
Get PDFTwo different water extremes, drought and waterlogging, exert profound detrimental impacts on
productivity and yields of alfalfa. With climate change intensifying globally, these abiotic
stressors are projected to escalate in prevalence, exacerbating agricultural challenges. To
minimize existing losses, there is a critical need for the development of new alfalfa cultivars that
can better withstand these types of stresses; however, progress has been hindered by the
complexity of stress tolerance mechanisms, as well as significant gaps in our understanding of
these processes. As such, I sought to provide further insight into the mechanisms behind
resilience to waterlogging and drought stresses in alfalfa through the assessment of genotypes in
which two transcription factors, WUSCHEL-related homeobox 13-2 (MsWOX13-2) and
telomerase activator 1/regulator of symbiosome differentiation (MsTAC1/RSD), had been downregulated, respectively. Both of these genes had been implicated in abiotic stress responses
previously; however, their roles in alfalfa had yet to be elucidated.
In the case of alfalfa MsWOX13-2, which I found to be expressed preferentially in roots
and differentially under waterlogging stress, the RNAi-mediated down-regulation of MsWOX13-
2 in alfalfa had no effects on growth or morphological characteristics under control (well-watered) conditions. However, under waterlogged conditions, MsWOX13-2 RNAi plants
exhibited enhanced performance, as evidenced by a reduced impact of stress on morphology and
greater survivability compared to empty vector genotypes. In addition, MsWOX13-2 RNAi
genotypes exhibited an apparent reduction in leaf chlorosis under waterlogging, which correlated
with higher chlorophyll retention and maximum quantum efficiency of photosystem II (Fv/Fm),
compared to empty vector genotypes. This reduction in stress symptoms was associated with
reduced malondialdehyde (MDA), which is a marker for oxidative stress, and higher superoxideiii
dismutase (SOD) activity in MsWOX13-2 RNAi leaves. RNA-Seq analysis confirmed the
presence of differentially expressed genes (DEGs) related to photosynthesis, antioxidant
activities, anaerobic respiration, cell wall modulation, phytohormone-related pathways, and
transcription factors. Subsequently, CRISPR/Cas9 was used to edit the MsWOX13-2 gene in
alfalfa with up to two alleles mutated in the first generation, resulting in bi-allelic mutations that
conferred waterlogging tolerance and enhanced branching.
Alfalfa MsTAC1/RSD, on the other hand, which shares orthology with Arabidopsis TAC1
and Medicago truncatula RSD, was highly expressed in nodules in a manner similar to MtRSD
and was up-regulated as drought stress progressed. Under well-watered conditions,
MsTAC1/RSD RNAi genotypes had equivalent biomass production with smaller stem diameter
and delayed flowering, as well as increased lateral root branching. Under drought conditions,
these genotypes exhibited improvements in their resilience to water-deficit compared to empty
vector control genotypes as evidenced by higher plant height and dry root biomass following
drought recovery. This tolerance to drought could be attributed, at least in part, to a reduction in
stomatal density, and a consequent decrease in leaf water loss, along with improved baseline
total antioxidant capacity and higher superoxide dismutase (SOD) and catalase (CAT) activity
under drought stress. In line with this, transcript profiling via RNA-Seq demonstrated changes in
the expression of genes related to photosynthesis, antioxidant activities, cell wall modulation,
phytohormones, and transcription factors, which could have contributed to the observed
improvements in MsTAC1/RSD RNAi genotypes under drought stress. Additionally,
MsTAC1/RSD RNAi genotypes exhibited shorter telomeres, as evidenced by lower relative
telomere length, and showed impaired nodulation, with fewer pink nodules compared to wildiv
type genotypes. Enhanced drought resilience and impaired nodulation were further confirmed
through CRISPR/Cas9-mediated knock-out of the MsTAC1/RSD gene in alfalfa.
Taken together, these results indicate that MsWOX13-2 and MsTAC1/RSD function as
negative regulators of waterlogging and drought stress response in alfalfa, respectively.
However, MsTAC1/RSD seems to be positively associated with telomere maintenance and
nodulation, suggesting its multiple roles in plant development and stress response in alfalfa.
While MsTAC1/RSD CRISPR genotypes will not provide a beneficial source of germplasm due
to the fact that these genotypes do not produce nitrogen-fixing nodules, transgene-free genomeedited MsWOX13-2 CRISPR genotypes could be ideal candidates for improving alfalfa
productivity under adverse environmental conditions in the future
Experimental and Modeling Investigation of Brine-Salt Rock Interactions and Permeability of Salt Rocks for Hydrogen Storage in Salt Caverns
No full textIn recent years, the use of salt caverns for hydrogen storage has gained increasing attention as a promising solution for supporting the global transition toward a carbon-neutral economy. This approach is seen as essential for achieving net-zero emissions and facilitating the move toward a sustainable energy future. The geological properties of salt caverns make them particularly suitable for this purpose due to their low permeability and high injection-withdrawal cycle frequency, which are ideal for safely storing hydrogen gas. Despite these advantages, several challenges remain, particularly related to the interaction between salt rocks and high salinity brines, which can lead to structural weakening.
In this study, we investigated the factors that contribute to the weakening and cracking of salt rock when exposed to high salinity brine. Through a series of experiments using brine with salinities of 0 ppm, 50,000 ppm, 150,000 ppm, and 250,000 ppm, and salt rock samples containing halite, calcite, dolomite, quartz, and K-feldspar, we observed that prolonged exposure to brine can lead to the formation of oversized pores, up to 50 μm in diameter, on the surface of the salt rock. These enlarged pores can compromise the structural integrity of the rock, leading to increased permeability and potential failure of the storage system. Our analysis suggests that the primary mechanisms driving this damage are: (1) the combined dissolution and detachment of halite crystals embedded within the salt rock, and (2) the similar dissolution and detachment of calcite and dolomite grains, which are present as impurities. These processes lead to significant changes in the rock's microstructure, contributing to its overall deterioration.
Additionally, we developed a novel methodology to accurately measure the permeability and porosity of salt rocks under hydrogen gas flow. This new approach employs modified boundary conditions, differing from the conventional Pressure Pulse Decay (PPD) method. In the PPD method, permeability is determined by creating a pressure gradient across the core, which can result in overestimated permeability due to hydrogen leakage through the sleeve and the sleeve-rock interface. By contrast, our method involves applying identical negative pressure pulses at both ends of the sample. This allows the gas, initially at higher pressure within the sample, to flow toward both ends through the pore spaces of the rock, which minimizes the possibility of leakage. The novel technique offers improvements in measurement accuracy, reducing errors by at least tenfold. Additionally, it significantly shortens the measurement time it by a factor of at least four compared to PPD method.
Our results indicate that the measured permeability values for salt rocks fall within the nano-darcy range, with the porosity values below 5%. However, this study also highlighted the presence of slippage effect during hydrogen flow through salt rock samples. during hydrogen flow through salt rock samples. The slippage effect, or Klinkenberg effect, occurs when the gas molecules are more frequently interacting with the pore walls than with each other. This happens when the mean free path of the gas molecules (the distance a molecule travels before colliding with another molecule) becomes comparable to or larger than the size of the pores in the rock. In such cases, the gas flow is dominated by collisions between the gas molecules and the pore walls, rather than collisions between the gas molecules themselves. This interaction results in an apparent increase in permeability, as the gas can flow more easily through the rock compared to Darcy flow, where molecular collisions dominate. Our results show that sample #1 exhibited an intrinsic permeability of 3.47 nD and a Klinkenberg coefficient of 4.05 MPa, sample #2 showed 17.265 nD and 1.89 MPa, and sample #3 had 3.14 nD and 2.22 MPa. Additionally, the porosity of the samples was generally below 5%, measured at 2.7%, 3.2%, and 1.5% for sample 1 to 3, respectively. As a result, we determined that the permeability measurements must be corrected for the slippage effect to accurately reflect the intrinsic permeability of the salt rock, which is critical for reliable predictions of hydrogen containment and long-term cavern stability
Arctic River Temperature Data
No full textRiver water temperature data produced using the A-HYPE hydrological model for the Arctic rivers for. Data is monthly, from 1981 to 2018. Data is formatted by river subid, latitude, longitude and then for each month the temperature at the runoff point