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1	Materiály pro fúzní aplikace a jejich interakce s tokamakovým plazmatem / Materiály pro fúzní aplikace a jejich interakce s tokamakovým plazmatem Klevarová, Veronika January 2016 (has links) Title: Materials for fusion applications and their interaction with tokamak plasma Author: Veronika Klevarová Department: Department of Physics of Materials Supervisor: doc. RNDr. Miloš Janeček, CSc., Department of Physics of Materials Abstract: Tungsten represents a perspective option in the context of fusion devices first-wall materials. In the first part of this work, set of tungsten samples with variable grain size was prepared by spark plasma sintering. Specimens were exposed to steady state deuterium plasma beam and high energy heat pulses, simulating thus the normal operation in the tokamak. As a consequence of the exposure, samples surfaces were roughened, as-prepared grains were recovered and in some cases cracks were formed. Moreover, post-irradiation analysis of the damaged samples revealed activation of in-grain slip systems within the loaded surfaces. Threshold grain diameter for this mechanism was determined to be between 5.5 - 6.6 μm at the particular loading conditions. However, damaged features showed to depend more on the fabrication parameters than on the grain diameter. Synergistic effects of simultaneous loading were proven to be important since those reduced the heat propagation within the volume of the tested samples. In the second part of this thesis, introduction to plasma-surface...
2	Advanced materials for plasma facing components in fusion devices Thomas, Gareth James January 2009 (has links) This thesis describes the design, manufacture and characterisation of thick vacuum plasma sprayed tungsten (W) coatings on steel substrates. Fusion is a potentially clean, sustainable, energy source in which nuclear energy is generated via the release of internal energy from nuclei. In order to fuse nuclei the Coulomb barrier must be breached - requiring extreme temperatures or pressures – akin to creating a ‘star in a box’. Tungsten is a promising candidate material for future fusion reactors due to a high sputtering threshold and melting temperature. However, the large coefficient of thermal expansion mismatch with reactor structural steels such as the low activation steel Eurofer’97 is a major manufacturing and in-service problem. A vacuum plasma spraying approach for the manufacture of tungsten and tungsten/steel graded coatings has been developed successfully. The use of graded coatings and highly textured 3D interface surfi-sculpt substrates has been investigated to allow the deposition of thick plasma sprayed tungsten coatings on steel substrates. Finite element models have been developed to understand the residual stresses that develop in W/steel systems and made use of experimental measurements of coating thermal history during manufacture and elastic moduli measured by nano-indentation. For both the graded and surfi-sculpt coating, the models have been used to understand the mechanism of residual stress redistribution and relief in comparison with simple W on steel coatings, particularly by consideration of stored strain energy. In the case of surfi-sculpt W coatings, the patterned substrate gave rise to regular stress concentrating features, and allowed 2mm thick W coatings to be produced reproducibly without delamination. Preliminary through thickness residual stress measurements were compared to model predictions and provided tentative evidence of significant W coating stress relief by regulated coating segmentation. 621.48
3	A promise kept: the mystical reach through loss Collins, Jody 04 October 2019 (has links) The meaning of loss is love. I know this through attention to experience. Whether loss or love is experienced in abundance or in absence, the meaning is mystical with an opening of body, mind, heart and soul to spirit. And so, in the style of a memoir, in the way of contemplative prayer, I contemplate and share my soul as a promise kept in the mystical reach through loss. With the first, initiating loss, the loss of my nine-year-old nephew, Caleb, I experience an epiphany that gives me spiritual instructions that will not be ignored. I experience loss as an abundance of meaning that comes to me as gnosis, as “knowledge of the heart” according to Elaine Pagels or divine revelation in what Evelyn Underhill calls mystical illumination in the experience of “losing-to-find” in union with the divine. Then, with gnostic import, in leaving the ordinary for the extraordinary, I enter the empty room in the painful yet liberating experience of the loss of my self. In the embrace of emptiness, I proceed to the first wall, the second wall, the third wall, the dark corner of denial, the return to centre, and, finally, to breaking the fourth wall in the empty room so as to keep my promise to you. Who are “you”? You are God. You are Caleb. You are spirit. You are my higher soul or self. And, you are the reader. You are my dear companion in silence. And then, through a series of broken promises and more loss, within what John of the Cross calls, “the dark night of the soul,” I am stopped by the ineffability of the dark corner of denial, the horror of separation and the absence of meaning, which is depicted as the grueling gap between the spiritual abyss and the breakthrough. What does it mean to keep going through a solemn succession of losses? I don’t know. In going into the empty room, I simply put pain to work in order to reach you. Through loss, though there are infinite manifestations, there is only one way: keep going. And so, in a triumph of the spirit, I keep going so as to be: a promise kept in the mystical reach through loss. As for you, through my illumined and dark experiences of loss, what is my promise to you? I keep going to reach the unreachable you. In the loss of self, with embodied emptiness, in going into the dark corner of denial, with a return to the divine centre of my emptied self, in an invitation to you, I give my soul to you in union with you. / Graduate / 2020-06-25 mystic mysticism apophatic cataphatic mystical mystical reach a promise kept empty promise broken promise reverence epiphany losing-to-find gnosis loss union divine will parsing perfection Caleb Lanz put pain to work wholehearted emptiness the empty room first wall second wall third wall dark corner of denial stonewall breaking the forth wall return to centre Promised Land abyss gap standing in the gap void memoir contemplative prayer contemplation everywhere and nowhere revelation illumination ineffable ineffability metaphor higher self self-giving self-emptying embodied emptiness higher soul spirit the dark night of the soul mystical union God breakthrough infinity infinite dynamism spiritual instruction invitation to spirit paradox symbol eulogy spiritual eyes spiritual heart looking into the slow reveal remaining sudden I am everywhere and nowhere what is what ought to be what can be what will be what is as it already is on earth as it is in heaven no-self unknown spirituality

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