29 research outputs found
Phase Equilibria and Thermodynamic Modeling of Ethane and Propane Hydrates in Porous Silica Gels
No full textIn the present study, we examined the active role of porous silica gels when used as natural gas storage and transportation media. We adopted the dispersed water in silica gel pores to substantially enhance active surface for contacting and encaging gas molecules. We measured the three-phase hydrate (H)-water-rich liquid (L-W)-vapor (V) equilibria of C2H6 and C3H8 hydrates in 6.0, 15.0, 30.0, and 100.0 nm silica gel pores to investigate the effect of geometrical constraints on gas hydrate phase equilibria. At specified temperatures, the hydrate stability region is shifted to a higher pressure region depending on pore size when compared with those of bulk hydrates. Through application of the Gibbs-Thomson relationship to the experimental data, we determined the values for the C2H6 hydrate-water and C3H8 hydrate-water interfacial tensions to be 39 +/- 2 and 45 +/- 1 mJ/m(2), respectively. By using these values, the calculation values were in good agreement with the experimental ones. The overall results given in this study could also be quite useful in various fields, such as exploitation of natural gas hydrate in marine sediments and sequestration of carbon dioxide into the deep ocean.The authors acknowledge funding from
the Korea Ministry of Knowledge Economy (MKE) through
“Energy Technology Innovation Program”. This research is also
financially supported by Changwon National University in 2008
and partially supported by the Brain Korea 21 project
Reflections of a disk-less Inuk on Canada’s Eskimo identification system
No full textThis essay examines the reactions of several Inuit women to an identification system whereby from 1941 to 1978 the Canadian government required the Inuit to wear small numbered disks. The author presents each Inuk woman’s personal perspectives, including her own, through narratives, interviews, and songs. The second part discusses the historical context of the “Eskimo disk list” system and its repercussions decades after it was discontinued.Cet essai examine les réactions de plusieurs femmes inuit devant un système d’identification que le gouvernement canadien imposa aux Inuit de 1941 à 1978: ceux-ci devaient porter un petit disque sur lequel figurait le numéro qui leur avait été attribué. L’auteure présente le point de vue personnel de chacune de ces femmes inuit, incluant le sien, à travers des récits, des entrevues et des chansons. La deuxième partie discute du contexte historique du système «des numéros de disques inuit» et de ses répercussions plusieurs décennies après son abandon
Atauttikkut: Combining home and research
No full textMy experience as an Inuk graduate student working in my hometown has taught me many lessons. It is not as simple as being Indigenous to be able to do good research in the Arctic. There are also risks taken when we decide to work in the same place that we grew up. In this chapter, I discuss doing marine mammal research in my home community of Iqaluit, Nunavut and reflect on what it is like to conduct fieldwork in the Arctic as an Inuk researcher
Phase Behavior and C-13 NMR Spectroscopic Analysis of the Mixed Methane plus Ethane plus Propane Hydrates in Mesoporous Silica Gels
No full textIn this study, the phase behavior and quantitative determination of hydrate composition and cage occupancy for the mixed CH4 + C 2H6 + C3H8 hydrates were closely investigated through the experimental measurement of three-phase hydrate (H)-water-rich liquid (LW)-vapor (V) equilibria and 13C NMR spectra. To examine the effect of pore size and salinity, we measured hydrate phase equilibria for the quaternary CH4 (90%) + C 2H6 (7%) + C3H8 (3%) + water mixtures in silica gel pores of nominal diameters of 6.0, 15.0, and 30.0 nm and for the quinary CH4 (90%) + C2H6 (7%) + C 3H8 (3%) + NaCl + water mixtures of two different NaCl concentrations (3 and 10 wt %) in silica gel pores of a nominal 30.0 nm diameter. The value of hydrate-water interfacial tension for the CH4 (90%) + C2H6 (7%) + C3H8 (3%) hydrate was found to be 47 ?? 4 mJ/m2 from the relation of the dissociation temperature depression with the pore size of silica gels at a given pressure. At a specified temperature, three-phase H-LW-V equilibrium curves of pore hydrates were shifted to higher pressure regions depending on pore sizes and NaCl concentrations. From the cage-dependent 13C NMR chemical shifts of enclathrated guest molecules, the mixed CH4 (90%) + C2H6 (7%) + C3H8 (3%) gas hydrate was confirmed to be structure II. The cage occupancies of each guest molecule and the hydration number of the mixed gas hydrates were also estimated from the 13C NMR spectra.close9
Phase Behavior and <sup>13</sup>C NMR Spectroscopic Analysis of the Mixed Methane + Ethane + Propane Hydrates in Mesoporous Silica Gels
No full textBraiding Voices: The Hybrid Musical Identity of Inuk Soprano Deantha Edmunds
No full textThis dissertation investigates the musical identity of Inuk soprano, Deantha Edmunds. The Truth and Reconciliation Commission of Canada has issued Calls to Action for Indigenous language and culture, which extend to music institutions. Western art music academies hold a hegemonic power over the telling of Canadian music history and performance practice, effectively gatekeeping music at the highest academic level. Consequently, Edmunds’ music has been periodically met with confusion. Therefore, this study focuses on Edmunds’ hybrid musical identity, demonstrating the significance and resistance of her compositions and performances. As an embedded case study, this dissertation centres on Edmunds’ performance career, studying how her performances question early music performance practice and challenge Western art music listeners. This qualitative methodology illustrates that Edmunds enacts Calls to Action through her compositions and performances, a claim which is triangulated by personal interviews with Edmunds conducted by the author, literature reviews of the history and music of the Moravian Inuit, Indigenous sound studies, identity politics, and the music aesthetics of Truth and Reconciliation. Edmunds consistently uses her talent and position to uplift Inuit music traditions, and this research amplifies Edmund’s aspirations for Truth and Reconciliation through music.
Key findings reveal that Edmunds’ compositions and performances reclaim and redefine the colonial construct of music performance. Her compositions, such as her album Connections (2022) and her song-cycle Angmalukisaa 2024, braid Indigenous aesthetics into Western art music, reaffirming historically discounted Inuit voices. For authentic Inuit translations, Edmunds turns to Inuit Elders for guidance, deepening her connection to her community and furthering her efforts for language revitalization. Her music and storytelling are rooted in Indigenous history, promoting Truth and Reconciliation.
This research was made possible by Edmunds’ generous engagement with non-Indigenous listeners. This dissertation argues that Edmund’s music effectively reorients the definition of performance in Western art music. Leveraging her positionality, Edmunds creates a pathway to resilience for future Indigenous generations, especially her daughter Annabelle, whom she includes in her performances. In this way, Edmunds creates a living legacy that incites further research on listening positionality, performance theories, music scholarship, and Indigenous studies.D.M.A
Separation of SF6 from Gas Mixtures Using Gas Hydrate Formation
No full textThis study aims to examine the thermodynamic feasibility of separating sulfur hexafluoride (SF6), which is widely used in various industrial fields and is one of the most potent greenhouse gases, from gas mixtures using gas hydrate formation. The key process variables of hydrate phase equilibria, pressure-composition diagram, formation kinetics, and structure identification of the mixed gas hydrates, were closely investigated to verify the overall concept of this hydrate-based SF6 separation process. The three-phase equilibria of hydrate (H), liquid water (LW), and vapor (V) for the binary SF6 + water mixture and for the ternary N2 + SF6 + water mixtures with various SF6 vapor compositions (10, 30, 50, and 70%) were experimentally measured to determine the stability regions and formation conditions of pure and mixed hydrates. The pressure-composition diagram at two different temperatures of 276.15 and 281.15 K was obtained to investigate the actual SF6 separation efficiency. The vapor phase composition change was monitored during gas hydrate formation to confirm the formation pattern and time needed to reach a state of equilibrium. Furthermore the structure of the mixed N2 + SF6 hydrate was confirmed to be structure II via Raman spectroscopy. Through close examination of the overall experimental results, it was clearly verified that highly concentrated SF6 can be separated from gas mixtures at mild temperatures and low pressure conditions.close262
Opportunity for Aajiiqatigiingniq with Qamanittuaq youth: An examination of the factors impacting identity development and wellness
No full textThe community of Qamanittuaq, like many communities in Nunavut, suffers from disproportionate levels of youth suicide and substance related deaths (statistics Canada, 2016, Tootoo, 2018). This uncharacteristically high suicide rate in Nunavut has been described by Kral (2019) as a phenomenon that is a direct response to colonial disruption. The territory has begun to address the challenge strategically with the Inuusivut Anninaqtuq (IA) 2017-2022 action plan (United for Life, 2017). One key feature of the plan is to support community-led action for suicide prevention. This article presents the results from the first phase of a Canadian Social Sciences and Humanities Research Council (SSHRC) funded Participatory Action Research Project designed to empower youth as leaders and change agents in their community. Within phase one, we sought to answer to the following research question: what factors impact youth identity development and consciousness about traditional and contemporary Inuit values, culture, and knowledge systems? Through focus groups held with Grade 10-12 youth within the context of the Aulajaagtut course offering at the local High School, we wanted to learn how youth defined their Inuk identity in the face of pressures from school, community and media. Through an analysis of the thoughts and products shared within the focus groups conducted in February 2019, we were able to gather insights into factors that helped or hindered pride in identity, resilience in the face of challenges and a sense of wellbeing/belonging in community. This article gives voice to the youth who are often unheard in discussions of curriculum development and solutions to complex community issues
Stability conditions and guest distribution of the methane plus ethane plus propane hydrates or semiclathrates in the presence of tetrahydrofuran or quaternary ammonium salts
No full textIn this study, the stability conditions and guest distributions of methane (CH4) + ethane (C2H6) + propane (C 3H8) hydrates or semiclathrates are examined in the presence of tetrahydrofuran (THF) and quaternary ammonium salts such as tetra-n-butylammonium bromide (TBAB) and tetra-n-butylammonium fluoride (TBAF) through thermodynamic and spectroscopic analyses. The three-phase equilibria of hydrate or semiclathrate (H), liquid water (LW), and vapor (V) for the quinary CH4 + C2H6 + C3H 8 + THF + water, CH4 + C2H6 + C 3H8 + TBAB + water, and CH4 + C 2H6 + C3H8 + TBAF + water mixtures with various concentrations were experimentally measured in order to determine the hydrate or semiclathrate stability conditions. The experimental results demonstrated that all thermodynamic promoters such as THF, TBAB, and TBAF used in this study could remarkably stabilize the hydrate dissociation conditions even though the degree of stabilization was dependent on the type of promoters and on the concentrations of each promoter used. From the 13C NMR analysis, preferential occupation of CH4 molecules in the hydrate or semiclathrate lattices was observed at the stoichiometric concentrations of each hydrate or semiclathrate structure. However, at the THF mole fraction lower than 0.056, the large cages of structure II were shared by CH4, C2H6, C3H8, and THF molecules, whereas the small cages were occupied by only CH4 molecules. The results given in this study are very useful in understanding the thermodynamic stability, structural characteristics, and guest distribution of the hydrates or semiclathrates with multi-components in the presence of thermodynamic promoters for further applications in gas storage and separation processes.close1
