89 research outputs found
Effect of alloying on the microstructure, phase stability, hardness and partitioning behavior of a new dual-superlattice nickel-based superalloy
A novel y-y'-y" dual-superlattice superalloy, with promising mechanical
properties up to elevated temperatures was recently reported. The present work
employs state of the art chemical and spatial characterization techniques to
study the effect systematic additions of Mo, W and Fe and variations in Nb and
Al contents have on the phase fraction, thermal stability, elemental
partitioning and mechanical properties. Alloys were produced through arc
melting followed by heat treatment. Multi-scale characterization techniques and
hardness testing were employed to characterize their microstructure, thermal
stability and mechanical properties. Alterations in such properties or in
elemental partitioning behaviour were then explained through thermodynamic
modelling.
A modest addition of 1.8 at.% Mo had a strong effect on the microstructure
and thermal stability: it minimized microstructural coarsening during heat
treatments while not significantly decreasing the y' solvus temperature. A
reduction of Nb by 0.6 at.%, strongly reduced the y" volume fraction, without
affecting the y' volume fraction. The reduced precipitate fraction led to a
significant reduction in alloy hardness. Fe, added to achieve better
processability and reduced material cost, decreased the y' solvus temperature
and caused rapid microstructural coarsening during heat treatments, without
affecting alloy hardness. A reduction of Al by 0.4 at.%, reduced the y' volume
fraction and the y' solvus temperature, also without affecting alloy hardness.
The addition of 0.9 at.% W decreased the y' solvus temperature but increased
both precipitate volume fractions. These data will be invaluable to optimize
current alloy design and to inform future alloy design efforts
Die Libellen des Neffelbachtales bei ZĂŒlpich
Jochen Rodenkirche
Nachtrag zur Schmetterlingsfauna des Bausenbergs (Eifel)
Matthias Forst und Jochen Rodenkirche
When life takes a turn : Parents' experience of having a child sick in cancer
Bakgrund: Barncancer Ă€r ett Ă„terkommande och skrĂ€mmande Ă€mne. Varje Ă„r insjuknar ca 300 barn i cancer i Sverige. Detta drabbar givetvis barnen sjĂ€lva men ocksĂ„ förĂ€ldrarna. För att fĂ„ mer förstĂ„else inom barncancervĂ„rden behövs mer forskning om förĂ€ldrars upplevelser och vad som Ă€r viktigt för dem under sjukdomens förlopp. Syfte: Syftet var att undersoÌka foÌraÌldrars upplevelser, kĂ€nslor och erfarenheter av att ha ett cancersjukt barn. Metod: En litteraturstudie som metod anvĂ€ndes. Tio vetenskapliga artiklar i databaserna PubMed och Cinahl anvĂ€ndes. Erikssons omvaÌrdnadsteori anvĂ€ndes som teoretisk ram av studien. Resultat: Majoriteten av förĂ€ldrarna beskrev den första kĂ€nslan av chock och oro nĂ€r barnet fick diagnosen. MĂ„nga kĂ€nde sig maktlösa och otillrĂ€ckliga. NĂ€r den nya vardagen förĂ€ndrats och anpassats lĂ„g fokus endast pĂ„ vad som skedde just dĂ„, ingenting kunde tas för givet. Det gick inte att planera framtiden i och med cancerbeskedet och den lĂ„nga vĂ„rdtiden. Majoriteten av förĂ€ldrarna upplevde Ă€ven att sjuksköterskan hade god kompetens till att stötta och informera om olika behandlingar, samt med god kunskap om Ă€mnet kunde förmedla detta pĂ„ ett empatiskt och pedagogiskt sĂ€tt för att frĂ€mja hĂ€lsa och god vĂ„rd gentemot familjen. Slutsats: NĂ€r ett barn drabbas av cancer Ă€r det svĂ„rt att veta hur barnet kommer att mĂ„. Det Ă€r ocksĂ„ svĂ„rt, oavsett kunskap, att veta hur förĂ€ldrarna kommer reagera dĂ„ alla reagerar och hanterar situationer olika. Det Ă€r dĂ€rför viktigt att sjuksköterskan skapar en god relation till familjen för att sedan kunna informera bĂ„de förĂ€ldrarna och barnet i ett tidigt skede om vad som hĂ€nder, och kommer att hĂ€nda, under den lĂ„nga och jobbiga tid som vĂ€ntar dem framöver.Background:Childhood cancer is a recurring and frightening subject. Each year, about 300 children becomes ill in cancer in Sweden. This of course affects the children themselves, but also the parents. To gain more understanding in childhood cancer care, more research is needed on parents' experiences and what was important for them during the disease process. Aim:The purpose was to investigate parents' different experiences and feelings of having a child sick in cancer. Method:A literature study was used as method. Ten scientific articles from the databases PubMed and Cinahl were used. Erikssonâs nursing theory was used as theoretical framework of this study. Result: A majority of the parents described the first feeling of shock and anxiety when they found out the diagnosis. Many parents felt powerless and inadequate. When their new everyday life changed and adjusted, the focus was only on what happened at that time and nothing could be taken for granted. They were not able to plan the future due to the cancer diagnosis and the long treatment period. The majority of the parents also felt that the nurse had good competence to support and inform about different treatments and with good knowledge of the subject could convey in an empathic and educational way to promote health and good care towards the family. Conclusion: When a child gets sick in cancer, it is difficult to know how the child will feel. It is also difficult regardless of knowledge, to know how the parents react when everyone reacts and handles situations differently. It is therefore important that the nurse first of all creates a relationship with the family, and then informs the parents at an early stage about what is happening and will happen in the long, hard time the child will be treated
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