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Potassium sulphate production from an aqueous sodium sulphate waste from lead acid battery recycling
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Applied Science in Industrial Systems Engineering, University of Regina. xvii, 216 p.In Canada and around the globe, government and regulatory agencies have implemented regulations to regulate the industries' amount and concentration of waste disposed into the environment. The regulations are enacted and executed to protect human, animal or plant health or the environment and other micro-organisms that form part of the ecosystem. Hence, there is a high industrial demand for value-added waste management methodologies, safer management, and disposition of industrial wastes. Also, the high demand for renewable energy sources necessitates the demand for energy storage technologies. Because of the comparative advantages that lead acid batteries have over other energy storage technologies, there is an increasing demand and use of lead acid batteries in various industrial operations. The lead acid battery waste stream is a significant source of Na2SO4, which is a potential reagent for production of K2SO4 for the fertilizer market. Various researchers have investigated the conversation Na2SO4 to K2SO4 and NaCl based on the assumption that Na2SO4 is pure. With this assumption, previous researchers did not investigate the capability of the impurities to either inhibit or amplify the conversion process. The Na2SO4 recovered from the recycling of lead acid battery is far from pure. The recovered Na2SO4 could not meet the market quality for commercialization because of the level of impurities - traces of heavy metals in it. The impurities in the solution are known to impede the crystallization process, with limited examples known to enhance the growth rate. HSC Chemistry and SysCAD simulation programs were used in this study to simulate the production of K2SO4 and NaCl from Na2SO4 and KCl, with the impurities accounted for in the feedstocks. The SysCAD program was used for validation of the HSC Chemistry with a strong similarity between the results from the two programs. It was found that it is possible to achieve over 90% yield and purity of K2SO4 from the Na2SO4 waste stream from lead acid battery
recycling at a constant pressure of 1 bar, feed temperature of 25oC and reactor temperature of 40oC. However, when the impurities were factored into the feeds, the yield of the K2SO4 dropped from 97.8 to 84.5% and NaCl from 93.7 to 75.8%. In other words, an inversely proportional relation was observed between the yield of both the K2SO4 and NaCl and the level of impurities in the feed. The elemental equilibrium composition of the two reactors indicated a significant decrement of potassium (K) and chlorine (Cl) molecules when the level of impurities was varied from 1% to 10%. Between the impurities levels of 0 to 3%, yields of both k2SO4 and NaCl greater 90% were achieved. Thereafter, the yields dropped below 90%. This observation indicated the need for more raw material (KCl) to increase the presence of K and Cl molecules in the reactors – by implication, an increase in the cost of raw material. Based on the results, it is evident the impurities have detrimental effects on the production of K2SO4 and NaCl from Na2SO4 and KCl.
Thermoeconomic analysis showed a directly proportional relationship between the impurity degrees and the exergy – both fuel exergy unit cost and product exergy unit cost for the system. This observation is an indication that the impurities in the feedstock will make the system demand more energy and do more work. Hence, it is essential to ensure that the feed is as pure as possible. The results of this simulation show that at the impurity ranges of 0% to about 4%, the system can achieve yield and purity of over 90% for both K2SO4 and NaCl.
Economic assessment of the simulated process was done with a Net Present Value (NPV). estimated at $63.5 million, ROI of 27%, and a payback period of 3.37 years.Studentye
Part-aware vehicle re-identification using harder negative aware triplet loss and attention embedded learnable resizer
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Applied Science in Industrial Systems Engineering, University of Regina. xii, 107 p.Vehicle re-identification is identifying and position referencing a vehicle of interest through images or video streams collected using a network of camera stations. This task is crucial in intelligent transportation systems and smart city development. However, vehicle re-identification poses a difficult problem due to various challenges, including intra-class variations, inter-class similarities, and near duplicate pairs. These challenges lead to a considerable false-positive rate in retrieved candidates. This research aims to design and develop a robust deep-learning-based vehicle re-identification system to address these challenges.
Effective training of deep learning models requires image down-scaling in preprocessing step, which can lead to a loss of detail in the input image. A recognition-aware attention-embedded learnable resizing module is employed in the preprocessing step to tackle this challenge. Furthermore, to overcome the inter-class similarity problem, a harder-negative-aware triplet loss, which produces a discriminative embedding space by focusing on dissimilarities in the dataset, is proposed. To improve the detailed-level perception of the framework, we incorporate the part-based local features into the feature extraction step along with the global information. The focus on the local features is extended further into the post-processing step, where the proposed candidates are validated via text-number tags (placed on the vehicle's body) verification for added robustness. Finally, to explore the effectiveness of the proposed vehicle re-identification framework, extensive experiments are conducted on a novel vehicle dataset. The dataset includes images of commercial vehicles and large trucks. The results show that our framework yields a Cumulative Match Curve at rank 1 of 99.62% and a Mean Reciprocal Rank of 99.56% on the novel dataset of commercial vehicles. Further analysis and study of the relationship between components of this framework point out the effect of the harder-negative-aware triplet loss on decreasing the false positive rate (4% improvement of Cumulative Match Curve at rank 1) by targeting the inter-class similarities challenge. Furthermore, the results display the exemplary impact of the local features extraction module on handling the near-duplicate challenge (14% further improvement of Cumulative Match Curve at rank 1) in the vehicle re-identification task.Studentye
Design optimization of sloshing tank using weakly compressible mesh free model
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Applied Science in Environmental Systems Engineering, University of Regina. vii, 70 p.In this study, the sloshing of the middle-baffled tank and non-baffled water tank under different external excitation frequencies and amplitudes. It was simulated and analyzed using the Weakly Compressible Moving Particle Explicit (WCMPE) method under condition of high-precision simulation data. Through the conversion of simulated data and images, the effects of baffle configuration, external excitation frequency and excitation amplitude, the effects of liquid sloshing were analyzed. The results showed that half-proportional baffles caused more complex liquid sloshing, which resulted in the dampening of the liquid slosh. On the other hand, it has been observed that the sloshing of the water tank at non-natural frequency also leads to the mutual cancellation of the particle velocities. With greater understanding of the sloshing and dampening effects, the focus of the study transitioned to the exploration in the relationship between the half-scale baffle and liquid depth at different position. Three case scenarios were simulated and analyzed. First, the length of the baffle was kept constant with gradual lifting of the baffle from the bottom of the tank until it protrudes the water surface. Secondly, the length of the baffle was gradually increased from bottom of tank until it protrudes above the water surface to explore the optimal damping effect. Lastly, the top of the baffle is situated immediately below the water surface. The baffle length was gradually shortened from the bottom of the tank until the baffle length is zero. Determination of the optimal ratio of baffle size and liquid depth was completed from the three hypothetical case studies.Studentye
Sedimentologic and lithostratigraphic properties and reservoir characterization of the Winnipeg Formation, Southern Saskatchewan
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Geology, University of Regina. vii, 112 p.The Winnipeg Formation is a Late Ordovician siliciclastic unit that occurs in subsurface of SE Saskatchewan. Deposition of the formation took place on the northern shelf of the sub-circular intracratonic Williston Basin. In the study area, the formation consists of two members: a lower sandstone-dominated Black Island Member and an upper shale-dominated Icebox Member. Core and well-log data from twenty-one wells, along with a detailed petrographic study of rock samples from the cores, have been collected, described, integrated, and interpreted. Textural properties, sedimentary structures, temporal stacking nature of the various lithofacies, and spatial correlation of the logged sections are significant tools used for deciphering the depositional environment, reservoir properties, and cyclostratigraphic analysis of the studied rocks. Ten lithofacies (eight quartz arenite and quartz wacke sandstones, one siltstone, and one shale) are recognized and interpreted as beach to lower offshore accumulations. The sandstone lithofacies are discriminated based on their textural and structural properties, e.g., grain size, bioturbation index (BI), hydrodynamic sedimentary structures, and matrix content. Well correlations show that the basin was somewhat funnel-shaped, with the central axis deepening southward, whereas uplifted flanks to the north and east define the direction of the shallower basin margins.
The vertical succession of the Winnipeg Formation is defined by shallow marine, high-energy sandstone of the Black Island Member overlain by relatively deep shelf shales of the Icebox Member. This stratigraphic succession underscores that deposition of the formation in the study area is characterized by a deepening-upward pattern. The Black Island Member's sandstone contains rhythmic units. Despite the overall deepening of the basin, the rhythmic units of the sandstone member underscore flooding events followed by progradation. These are parasequences within the transgressive systems tract. The transgression culminated during the deposition of the shales of the Icebox Member. The unconformity between Icebox and Yeoman Fm. defines the sea level drop and erosion of the uppermost beds (Roughlock Member) of the Winnipeg Formation. This regressive phase is represented by an erosional gap. Toward down south in North Dakota, there is a third member of the formation (Roughlock Member), which may represent the regressive phase of the T-R cycle.
Subsurface mapping shows variations in the thickness in three zones. Zone-1 constitutes most of the mapped area, and the isopach map shows that the formation thickens approximately 140m towards the southeast of the province. Zone-2 occurs west of Zone-1 and shows a relatively thinner distribution approximately 60m of the formation. This zone shows a northeast-southwest trend possibly controlled by high paleotopographic features. In Zone-3, the formation gets thicker, approximately 80m west of Zone-2. Depth structure map and 3D mapping show the basin was shallower towards the north, northeast, and northwest and deeper towards the south. The porosity interval map shows the thickness of the porous interval increasing southeastward.
The reservoir properties of Black Island Member are classified as quartz arenite, lithic arenite, two types of quartz wacke, feldspathic greywacke, and two types of mudrocks. Among the different well cores studied, the combined quartz arenite lithofacies constitute about 47% of the member, whereas the wacke and the mudrock lithofacies constitute 44% and 9%, respectively. Isopach maps of the various lithofacies indicate that the quartz arenites occur south to southeast, quartz wackes from southwest to southeast, and mudrocks toward the southeast of the studied area. Furthermore, the porosity of the quartz arenites ranges between ~22% and ~29%, whereas that of the wacke sandstone varies from ~8% to ~11%; these are affected by the different diagenetic processes. Thus, the sandstone lithofacies (the arenites and the wackes), which form a total thickness of about 91% of the member, are envisaged to constitute fair to excellent reservoirs.Studentye
Regina 1973 - Trajectories in Clay
No full textIn 1973, six ceramists represented Canada in Parisat an exhibition called
Canada Trajectoires 73 Musee d’Art Moderne de la ville de Paris (“CanadaTrajectories”):
Vic Cicansky, Joe Fafard, Dave Gilhooly, Ann James, Marilyn Levine, and Russ Yuristy. All six of the artists worked in Regina during the 1960s and ‘70s.
Most were still in Regina in ’73
Experiences of professionals working with pre-adolescent children who are using psychoactive substances in Regina, SK
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Social Work, University of Regina. vii, 224 p.The purpose of this thesis research was to 1) explore the pathways to seeking and accessing support for substance use among pre-adolescents from the point of view of professionals working with children under age of 12, and, 2) examine how these professionals’ views on pre-adolescent substance use inform what services this population receives. The goal of the study was not only to understand how preadolescents access services for substance use but how the views of professionals assist or create barriers to accessing these services. The study used a qualitative, multiple case study method to interview four service providers, representing different jurisdictions and services, who worked with children and their families in Regina, SK. Five key themes emerged from the study: (1) the main pathway that leads to pre-adolescents receiving addictions services is through family involvement with child protection services; (2) a system of services within Regina, SK is fractured with many organizations providing mental health and addictions services but none specializing on the pre-adolescent population; (3) the perceptions of and beliefs about substance use among preadolescents’ that service providers have inform their practice; (4) service providers emphasize education and prevention to reduce pre-adolescent substance use; and (5) there are assumptions that Indigenous children are more likely to be involved in substance use than their non-indigenous counterparts.Studentye
Efficacy of a brief online mindfulness and self-compassion intervention (Mind-OP+) to increase connectedness: Randomized controlled trial
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Clinical Psychology, University of Regina. viii, 123 p.Connectedness is defined as a connection with others that promotes well-being. Although studies examining connectedness are few to date, the extant literature on closely related concepts suggests connectedness is associated with reduced symptoms of psychological and physical disorders and higher overall well-being. Cultivating feelings of connectedness also appears to encourage prosocial behaviour, such as volunteering or donating to charity. Mindfulness and compassion interventions (MBIs) may be adapted to cultivate feelings of connectedness, thereby unlocking a protective mechanism in mental health and beyond. Further, brief self-guided MBIs are particularly promising, given demonstrations of their efficacy combined with their potential for wide scalability and dissemination. Accordingly, this author examined the effectiveness of an augmented, self-guided, brief, online mindfulness and self-compassion-based intervention (Mind-OP+) to facilitate perceptions of connectedness in undergraduate students. Total of 117 undergraduate students were randomized into a waitlist (n = 55) or Mind-OP+ (n = 62) condition. Participants in the Mind-OP+ condition completed five modules at a pace of one module per week. Correlation analyses with participants that passed baseline attention-checks (n = 101 ) revealed that social connectedness at baseline was correlated positively with mindfulness and self-compassion, and correlated negatively with fears of compassion, depression, anxiety, and stress. Relatedness at baseline was correlated positively with mindfulness and negatively with fears of compassion and depression, stress, and anxiety. Intent-to-treat mixed-model analyses on all randomized participants indicated that, compared to participants in the waitlist condition, participants in Mind-OP+ reported increased feelings of social connectedness (d = 0.81) and relatedness (d = 0.64) at post-treatment, and increased feelings of social connectedness (d = 0.80) and relatedness (d = .38) at one-month follow-up. Mediation analyses completed with protocol adherent participants at post-treatment (n = 47) demonstrated no statistically significant mediation of self-compassion or mindfulness scores on the relationship between group membership and connectedness nor relatedness scores at post-treatment. These findings provide support for the use of brief, accessible, self-guided interventions to cultivate connectedness. Larger, more definitive trials should compare the effects of Mind-OP+ for connectedness against an active control, and examine whether the effects on connectedness are independent of effects of reducing psychological disorder symptoms. This intervention holds promise as an option for those seeking protective factors for their mental health and general resiliency.Studentye
Controls of thermal response of temperate lakes to atmospheric warming
No full textAtmospheric warming heats lakes, but the causes of variation among basins are poorly understood. Here, multi-decadal profiles of water temperatures, trophic state, and local climate from 345 temperate lakes are combined with data on lake geomorphology and watershed characteristics to identify controls of the relative rates of temperature change in water (WT) and air (AT) during summer. We show that differences in local climate (AT, wind speed, humidity, irradiance), land cover (forest, urban, agriculture), geomorphology (elevation, area/depth ratio), and water transparency explain >30% of the difference in rate of lake heating compared to that of the atmosphere. Importantly, the rate of lake heating slows as air warms (P < 0.001). Clear, cold, and deep lakes, especially at high elevation and in undisturbed catchments, are particularly responsive to changes in atmospheric temperature. We suggest that rates of surface water warming may decline relative to the atmosphere in a warmer future, particularly in sites already experiencing terrestrial development or eutrophication.This work was supported by the National Natural Science Foundation of China (grants 42220104010 to B.Q., 42177058 to J.Z., U22A20561 and 41922005 to K.S., and 42007160 to Y.Z.), the National Key Research and Development Grant of China (2022YFC3204101) to J.Z and the NIGLAS foundation (E1SL002) to K.S., the Canada Research Chair Program to P.R.L., and US National Science Foundation (grants 1754265 and 2048031) to K.C.R
I was about to be them/there
No full textA Thesis Support Paper Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Fine Arts in Visual Arts, University of Regina. vi, 30 p.This paper supports my Master of Fine Arts graduation thesis exhibition, I Was About to Be Them/There, presented at the Fifth Parallel Gallery from December 13- 21 in 2023.
My MFA exhibition consists of videos of performances, an audio/video installation, and a photograph, through which I convey the experience of being subject to external forces that shape my behavior, thoughts, and emotions. This work offers a metaphoric perspective on my experiences as an Iranian woman, and resonates with the experiences of many other women in our homeland. I aim to share the confusion and paradox that arises from existing in two distinct worlds—here in Regina, tied to Iran—while my loved ones face imminent danger in Iran. I have experienced the simultaneous sensation of being distant from and yet incredibly close to the events unfolding in my country in 2022 and 2023. I Was About to Be Them/There serves as a medium for conveying this bewildering duality and the peril that threatens those dear to me.Studentye
Self-training for cyberbully detection: Achieving high accuracy with a balanced multi-class dataset
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Computer Science, University of Regina. xiii, 99.Cyberbullying has become an alarming issue in the digital era, causing significant
harm to its victims. The development of automated methods for detecting cyberbullying
in social media is of paramount importance to safeguard vulnerable individuals.
In this thesis, we propose a robust approach based on Machine Learning (ML) and
Deep Learning (DL) techniques for cyberbully detection in social media platforms.
Our approach involves the meticulous curation of a balanced dataset specifically
designed for training the ML/ DL models. To overcome the challenge of limited
labeled data, we employ a semi-supervised self-training algorithm, which effectively
expands the size of the labeled dataset. By leveraging real-world social media data,
we train and test the model, evaluating its performance using key metrics such as
precision, recall, and F1-score.
In addition, we present our meticulously annotated dataset comprising 99,991
tweets, which we have made publicly available for future scientific investigations.
This dataset serves as a valuable resource for further research in this field, facilitating
the development and evaluation of novel techniques for cyberbully detection.
Our results underscore the near-perfect performance of the proposed approach in
the context of cyberbully detection, reaffirming the efficacy of ML and DL techniques
for addressing this pervasive problem. These findings offer crucial insights for future
research endeavors in this domain and hold practical implications for the development
of automated systems capable of detecting and combating cyberbullying in social
media platforms.
By continuously advancing our understanding of cyberbullying detection and developing
sophisticated ML and DL models, we can foster safer digital environments
and protect individuals from the detrimental effects of cyberbullying.Studentye