4,047 research outputs found
The effect of high temperature exposure on the dendritic segregation in a conventionally cast Ni based superalloy
No full textDendritic segregation in conventionally cast, commercially heat treated and exposed MarM002 turbine blades has been investigated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). During casting Cr, Co and W segregate to the dendrites and Hf, Ti and Ta segregate to the eutectics. As a result of the dissolution of precipitates in the dendrites and coarsening of precipitates in the eutectics this segregation aggravates during exposure at 1000°C. At this high exposure temperature homogenisation of dendritic segregation does not occur because it involves long diffusion distances and a low driving force compared with dissolution and coarsening of precipitates
American Society for 18th century Studies, Studies in 18th century Culture, vol. 5, éd. R.C. Rosbottom, 1976
No full textThomson Ann. American Society for 18th century Studies, Studies in 18th century Culture, vol. 5, éd. R.C. Rosbottom, 1976. In: Dix-huitième Siècle, n°9, 1977. Le sain et le malsain. pp. 387-388
Modelling microstructural evolution in conventionally cast Ni-based superalloys during high temperature service
No full textModern conventionally cast (CC) Ni-based superalloys are highly alloyed metals that undergo a number of complex microstructural changes during in-service exposure to high temperatures. This paper focuses on modelling the kinetics of reactions involving carbides. An important element in various approaches for modelling of kinetics of reactions in Ni-based superalloys is so-called thermodynamic modelling (CALPHAD method). A detailed comparison of CALPHAD predictions made by one database with extensive long term experimental data for the MarM002 Ni-based superalloy for all phases is presented.A comparison of CALPHAD predictions made by the Thermotech database for Ni-based superalloys with long term experimental data shows that for the MarM002 Ni-based superalloy the volume fractions and compositions of the FCC gamma ?matrix, the L12 ordered gamma' and the M23C6 carbide phase are predicted well. Thermodynamic modelling is currently unable to predict the presence of M6C in this alloy. The reason for this is primarily due to the large number of carbides of different types and compositions within MarM002. There must be a balance of stability for all of the carbides and therefore slight perturbations to the Gibbs free energy polynomials describing each phase can limit the accuracy of the prediction for minor carbides. It is also shown that it is necessary to allow for a miscibility gap in the MC carbide phase to enable a more accurate prediction of its chemical composition in such a complex alloy system. A method for modelling the kinetics of reactions using an approximation of the diffusion fields around particles (i.e. akin to the well-known Johnson-Mehl-Avrami-Kolmogorov approach) is described. With this method the carbide reactions in during high temperature exposure of CC Ni-based superalloy can be accurately described.<br/
MC carbides in the Hf containing Ni based superalloy MarM002
No full textUnexposed MarM002 alloy turbine blades and blades exposed at 700-1000ºC for up to 250 days were studied by TEM, SEM, EDX and XRD. The shapes, distribution and compositions of the MC carbides do not vary significantly during exposure at 700 and 800ºC. All MC carbides contain significant amounts of Hf, Ta, Ti and W, and they are present with a very broad range of compositions. The latter is caused by a miscibility gap in the MC carbide phase which causes the formation of MC carbides to shift from Hf lean in the initial stages of solidification to Hf rich in the later stages. In the unexposed samples the Hf lean (Ti,Ta)C carbide is the most numerous one. The shape of the complex MC carbide diffraction peaks are explained semi-quantitatively on the basis of the compositional range of the MC carbides
Low temperature copper solubilities in Fe-Cu-Ni
No full textAn atom probe characterization of the copper concentration in the matrix of a model Fe–1.1at.%Cu–1.4% Ni alloy has been performed after isothermal ageing for various extended times at low temperatures. The matrix copper concentrations from material annealed at 500, 550 and 600°C are approximately 10% lower than the equilibrium values predicted from the Thermocalc™ program with the Kaufman database. Isothermal annealing for 4000 h at either 400 or 300°C was not sufficient to attain the equilibrium copper concentration. The kinetics of copper precipitation was investigated with the Starink-Zahra model derived for nucleation and growth reactions and a good fit with the atom probe data was found for an activation energy of 250 kJ mol?1
Belonging: natural histories of place, identity and home
No full textCanongate's synopsis:
"Reflecting on family, identity and nature, Belonging is a personal memoir about what it is to have and make a home. It is a love letter to nature, especially the northern landscapes of Scotland and the Scots pinewoods of Abernethy – home to standing dead trees known as snags, which support the overall health of the forest.
Belonging is a book about how we are held in thrall to elements of our past. It speaks to the importance of attention and reflection, and will encourage us all to look and observe and ask questions of ourselves.
Beautifully written and featuring Amanda Thomson’s artwork and photography throughout, it explores how place, language and family shape us and make us who we are."
Longlisted for the Highland Book Prize, 2023
Some of the reviews...
Outstanding - ROBERT MACFARLANE
Amanda Thomson’s new book manages to carve out a distinctive niche for itself . . . This is a passionate book and infused with a sense of rootedness - STUART KELLY, The Scotsman
In recent years rural landscapes have turned into battlegrounds, and nature writing has become increasingly polemical. Belonging is a quiet book of questions in a genre full of answers, but it is all the more powerful and beautiful for this - PATRICK GALBRAITH, TLS
One of the best things I have read in ages . . . Quiet and beautiful and powerful - ALYS FOWLER
Thomson writes of the natural in a way I have yet to encounter before. There is no real hoo-haa, no flowery description of which to speak yet somehow, I came away with that ache inside me — that renewed obsession with the world that is only borne of a very particular kind of writing — poetic, loving, raw . . . Like no other - KERRI Ní DOCHARTAIGH, Caught by the River
In strikingly original takes on Scottish history, environmentalism, Black feminist theory, artmaking, list-making, memory, and memoir, Thomson crafts a cadence that is as wise as it is vitally alive. - MARGOT DOUAIHY, author of Scorched Grac
Kathleen Jamie, Chitra Ramaswamy & Amanda Thomson: Antlers of Water - Live Event
No full text‘When we read and write, when we love our fellow creatures, when we walk on the beach, when we just listen and notice, we are not little cogs in the machine, but part of the remedy.’ These luminous words by Kathleen Jamie form part of the introduction to Antlers of Water, an outstanding collection of contemporary Scottish writing about nature and landscape.
The generosity of Jamie’s approach as editor of the collection goes beyond the stellar selection of contributors such as Amy Liptrot, Karine Polwart and Malachy Tallack: she also invokes the agency of readers to make a difference. ‘If, by reading, you are encouraged or confirmed in your love of the natural world, if you’re inspired simply to… look outside, then our job is done.’
In a discussion led by the BBC's Clare English, Jamie is joined by award-winning journalist Chitra Ramaswamy as well as visual artist and writer Amanda Thomson – both contributors to the anthology – to discuss Scotland, landscape and the more-than-human world around us.
This is a live event, with an author Q&A.
Part of the Edinburgh International Book Festival Making Climate Change Personal festival theme
Improved heart rate recovery despite reduced exercise performance following heavy training: a within-subject analysis
No full textAbstract not availableRebecca L. Thomson, Clint R. Bellenger, Peter R.C. Howe, Laura Karavirta, Jonathan D. Buckle
Taurorcus chabrillacii Thomson 1857
No full text66. Taurorcus chabrillacii Thomson, 1857 Distribution: Brazil (Minas Gerais, Paraná, Santa Catarina, Rio Grande do Sul), Argentina (Misiones). Material examined: BRAZIL, Paraná, Céu Azul, 700 m a.s.l., 25 o 04’09”S, 53°39’35”W. Canopy, Light trap (Luiz de Queiroz), 2 males, 13.IX.2015, R.C. Barros, R. Rockembacher & M.P. Rincão leg. (MZUEL).Published as part of De Barros, Rafael C., Da Fonseca, Mailson G., Vendramini, Vinicius E. & De Arvarenga Julio, Carlos E., 2019, Species of Lamiinae (Insecta, Coleoptera, Cerambycidae) from east Paraná State (Brazil), with new geographic records, pp. 179-204 in Zootaxa 4545 (2) on page 189, DOI: 10.11646/zootaxa.4545.2.2, http://zenodo.org/record/261877
Compsosoma phaleratum Thomson 1857
No full text90. Compsosoma phaleratum Thomson, 1857 Distribution: Brazil (Bahia, Espírito Santo, Rio de Janeiro, São Paulo, Paraná, Santa Catarina, Rio Grande do Sul). Material examined: BRAZIL, Paraná, Céu Azul, 700 m a.s.l., 25 o 04’09”S, 53°39’35”W. Understory, Light trap (Luiz de Queiroz), 1 male, 17.XII.2015, R.C. Barros, V.E. Vendramini & J.P.B. Pine leg. (MZUEL).Published as part of De Barros, Rafael C., Da Fonseca, Mailson G., Vendramini, Vinicius E. & De Arvarenga Julio, Carlos E., 2019, Species of Lamiinae (Insecta, Coleoptera, Cerambycidae) from east Paraná State (Brazil), with new geographic records, pp. 179-204 in Zootaxa 4545 (2) on page 192, DOI: 10.11646/zootaxa.4545.2.2, http://zenodo.org/record/261877
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