Performing Embodied Translations: Decolonizing Methodologies of Knowing and Being

This performance and transcript emerge from a collaborative journey that grapples with what it might mean to agitate dominant pedagogical and methodological conventions of Eurocentric Angophone academia. Together, we perform an argument and a search: for multiple entry points into decolonizing feminisms; for multiple modes of knowing and being that can interrupt and challenge the epistemes that are rooted in thoughts and practices of colonialism and coloniality; for interrogating the dominant politics of citation that often operate in academic practices in disembodied ways. We search for a politics of knowing that is firmly rooted in relationalities where power and authority can be shared across uneven and unequal locations and languages. We invite you to step into the spaces that we have started imagining here and push all of our collective conversations and imaginations further, beyond the silos that cage us in our disciplined modes of thinking, writing, arguing, and dreaming

Performance Assessment of Single Electrode-Supported Solid Oxide Cells Operating in the Steam Electrolysis Mode

An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production. Results presented in this paper were obtained from single cells, with an active area of 16 cm{sup 2} per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes ({approx}10 {mu}m thick), nickel-YSZ steam/hydrogen electrodes ({approx}1400 {mu}m thick), and modified LSM or LSCF air-side electrodes ({approx}90 {mu}m thick). The purpose of the present study is to document and compare the performance and degradation rates of these cells in the fuel cell mode and in the electrolysis mode under various operating conditions. Initial performance was documented through a series of voltage-current (VI) sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-term testing, first in the fuel cell mode, then in the electrolysis mode. Results generally indicate accelerated degradation rates in the electrolysis mode compared to the fuel cell mode, possibly due to electrode delamination. The paper also includes details of an improved single-cell test apparatus developed specifically for these experiments

Recent Advances in High Temperature Electrolysis at Idaho National Laboratory: Stack Tests

High temperature steam electrolysis is a promising technology for efficient sustainable large-scale hydrogen production. Solid oxide electrolysis cells (SOECs) are able to utilize high temperature heat and electric power from advanced high-temperature nuclear reactors or renewable sources to generate carbon-free hydrogen at large scale. However, long term durability of SOECs needs to be improved significantly before commercialization of this technology. A degradation rate of 1%/khr or lower is proposed as a threshold value for commercialization of this technology. Solid oxide electrolysis stack tests have been conducted at Idaho National Laboratory to demonstrate recent improvements in long-term durability of SOECs. Electrolytesupported and electrode-supported SOEC stacks were provided by Ceramatec Inc., Materials and Systems Research Inc. (MSRI), and Saint Gobain Advanced Materials (St. Gobain), respectively for these tests. Long-term durability tests were generally operated for a duration of 1000 hours or more. Stack tests based on technology developed at Ceramatec and MSRI have shown significant improvement in durability in the electrolysis mode. Long-term degradation rates of 3.2%/khr and 4.6%/khr were observed for MSRI and Ceramatec stacks, respectively. One recent Ceramatec stack even showed negative degradation (performance improvement) over 1900 hours of operation. A three-cell short stack provided by St. Gobain, however, showed rapid degradation in the electrolysis mode. Improvements on electrode materials, interconnect coatings, and electrolyteelectrode interface microstructures contribute to better durability of SOEC stacks

The measurement of stress and phase fraction distributions in pre and post-transition Zircaloy oxides using nano-beam synchrotron X-ray diffraction

Zircaloy-4 oxide stress profiles and tetragonal:monoclinic oxide phase fraction distributions were studied using nano-beam transmission X-ray diffraction. Continuous stress relief and phase transformation during the first cycle of oxide growth was observed. The in-plane monoclinic stress was shown to relax strongly up to each transition, whereas in-plane tetragonal stress-relief (near the metal-oxide interface) was only observed post transition. The research demonstrates that plasticity in the metal and the development of a band of in-plane cracking both relax the monoclinic in-plane stress.The observations are consistent with a model of transition in which in-plane cracking becomes interlinked prior to transition. These cracks, combined with the development of cracks with a through-thickness component (driven primarily by plasticity in the metal) and/or a porous network of fine cracks (associated with phase transformation), form a percolation path through the oxide layer. The oxidising species can then percolate from the oxide surface to the metal/oxide interface, at which stage transition then ensues

Simultaneous Microwave Extraction and Separation of Volatile and Non-Volatile Organic Compounds of Boldo Leaves. From Lab to Industrial Scale

Microwave extraction and separation has been used to increase the concentration of the extract compared to the conventional method with the same solid/liquid ratio, reducing extraction time and separate at the same time Volatile Organic Compounds (VOC) from non-Volatile Organic Compounds (NVOC) of boldo leaves. As preliminary study, a response surface method has been used to optimize the extraction of soluble material and the separation of VOC from the plant in laboratory scale. The results from the statistical analysis revealed that the optimized conditions were: microwave power 200 W, extraction time 56 min and solid liquid ratio of 7.5% of plants in water. Lab scale optimized microwave method is compared to conventional distillation, and requires a power/mass ratio of 0.4 W/g of water engaged. This power/mass ratio is kept in order to upscale from lab to pilot plant

Water as alternative solvent for green extraction of vegetal products

L’utilisation de technologies d’extraction est cruciale dans l’industrie cosmétique. Cette étape de procédé consomme beaucoup d’énergie et de grandes quantités de matières premières. De plus, les solvants utilisés ne sont pas tous anodins, et certains sont issus de produits pétroliers. Afin de mieux préserver l’environnement et la santé humaine, il faut trouver des alternatives aux solvants et aux méthodes d’extractions conventionnelles. Pour cela, nous avons utilisé l’eau comme solvant et des technologies innovantes pour créer de nouvelles méthodes. Les travaux présentés dans cette thèse font tout d’abord un état de l’art des méthodes d’extractions utilisant l’eau comme solvant. L’ensemble de ces méthodes très anciennes, comme récentes, ont toutes leurs spécificités en termes de matrices et de molécules extraites. Puis nous nous sommes intéressés à une méthode ancienne qu’est l’hydrodistillation. L’extraction et la séparation simultanée des composés hydrosolubles et volatiles des feuilles de boldo (Peumus boldus, Mol.) est ensuite effectuée à l’aide des micro-ondes. L’optimisation des paramètres ont ensuite aboutis sur un scale-up à l’échelle pilote. L’intensification et la mise en continu de l’extraction des feuilles de boldo assisté par ultrasons sont ensuite explorés. Puis, nous étudions une méthode en cours de maturation avec l’assistance des tensioactifs pour l’extraction de composés hydrophiles et hydrophobes du romarin (Rosmarinus officinalis L.) dans l’eau. Enfin, nous avons exploré une méthode d’extraction encore en R&D. Elle utilise uniquement l’eau pour obtenir des composés hydrophobes de l’écorce d’orange douce ( Citrus sinensis L.) à l’aide d’un appareil micro-ondes pour atteindre un état subcritique.The use of innovative extraction technologies is of outmost importance in the cosmetic industry. This process step is consuming large amounts of energy and materials. Furthermore, some solvents used are not benign. Some of them are from oil products. In order to better preserve the environment and human health, we must find alternatives to solvents and conventional extraction methods. To pursue this goal, we will use water as solvent and innovative technologies to create new extraction methods of natural products. The work presented in this thesis first establishes a review of extraction methods. All those methods, old as well as new ones, are specific in terms of target matrix or extracted molecules. Then, we focused on a mature extraction method: hydrodistillation. The simultaneous extraction and separation of water soluble compounds as well as volatile compounds from boldo leaves (Peumus boldus, Mol.), is undertaken with the help of microwaves. The parameters optimization leads to a pilot scale-up. The intensification and continuous mode transition of the ultrasound assisted extraction of boldo leaves is then studied. Afterwards, we studied the maturing method of surfactant addition to water. This is in order to extract hydrophilic and hydrophobic compounds of rosemary (Rosmarinus officinalis L.). Finally, we explored an extraction method still in R&D. This method use only water in order to extract hydrophobic compounds of sweet orange peels ( Citrus sinensis L.) with a microwave device