Microstructural characterisation of continuously cooled steels and steel welds

Fe-Mn-Si-C steels are currently the most widely used type of steel for structural, building and automotive applications. Additionally, these steels also find important applications within welded structures, due to their low cost and versatility with regard to chemical composition and heat treatments because of the possibility to tailor their final mechanical properties. The production of a specific component made out of such steels generally involves continuous cooling heat treatments. Therefore, the way in which an optimum balance is achieved between the heat treatment parameters, the alloy composition and the desired microstructure for a specific application, is a vital step in the investigation of Fe-Mn-Si-C steels.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A quantum particle in a box with moving walls

We analyze the non-relativistic problem of a quantum particle that bounces back and forth between two moving walls. We recast this problem into the equivalent one of a quantum particle in a fixed box whose dynamics is governed by an appropriate time-dependent Schroedinger operator.Comment: 12 pages, 0 figure

Imaging follow-up after liver transplantation

Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures.Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures

High-temperature microstructural evolution and quantification for alloys IN740 and IN740H: comparative study

In ultra-supercritical power plants, Ni-base alloys are candidate materials for long-term, high-temperature applications, operating at temperatures and pressures as high as 750°C and 35 MPa. Alloy IN740 and its modification, alloy IN740H, are considered for such applications. Their microstructural evolution, at 750°C for times ranging between 3000 and 5000 hours, has been investigated by means of scanning electron microscopy, electron back-scattered diffraction, energy dispersive X-ray analysis and phase quantification. All phases were identified and quantified allowing comparison between the two microstructures, their evolution and stability. Particular attention was paid to γ′, η and G phases. The results are used within a broader investigation aimed at improving and further developing a predictive creep model based on continuous damage mechanics

Improving biomarker list stability by integration of biological knowledge in the learning process

BACKGROUND: The identification of robust lists of molecular biomarkers related to a disease is a fundamental step for early diagnosis and treatment. However, methodologies for biomarker discovery using microarray data often provide results with limited overlap. It has been suggested that one reason for these inconsistencies may be that in complex diseases, such as cancer, multiple genes belonging to one or more physiological pathways are associated with the outcomes. Thus, a possible approach to improve list stability is to integrate biological information from genomic databases in the learning process; however, a comprehensive assessment based on different types of biological information is still lacking in the literature. In this work we have compared the effect of using different biological information in the learning process like functional annotations, protein-protein interactions and expression correlation among genes. RESULTS: Biological knowledge has been codified by means of gene similarity matrices and expression data linearly transformed in such a way that the more similar two features are, the more closely they are mapped. Two semantic similarity matrices, based on Biological Process and Molecular Function Gene Ontology annotation, and geodesic distance applied on protein-protein interaction networks, are the best performers in improving list stability maintaining almost equal prediction accuracy. CONCLUSIONS: The performed analysis supports the idea that when some features are strongly correlated to each other, for example because are close in the protein-protein interaction network, then they might have similar importance and are equally relevant for the task at hand. Obtained results can be a starting point for additional experiments on combining similarity matrices in order to obtain even more stable lists of biomarkers. The implementation of the classification algorithm is available at the link: http://www.math.unipd.it/~dasan/biomarkers.html

Modelling of creep and fracture properties of nickel based alloys

This paper reviews the differences between two nickel based alloys, Alloy 740 and Alloy 740H. Microstructural evolution models are used to forecast the changes in volume fraction and interparticle spacing of both grain boundary and intra-granular precipitates in the alloys. These data are then employed in continuum damage mechanics models to forecast creep curves, and in fracture mechanics models to forecast Charpy impact energies/energy. The results reveal the key microstructural features that control secondary and tertiary creep rate as well as the time dependence of Charpy impact energy after high temperature exposure

Seroma in lipoabdominoplasty and abdominoplasty: ultrasonographic comparative study

BACKGROUND: Seroma is one of the most common complications in abdominoplasty. OBJECTIVE: To compare the rate of seroma formation in patients who underwent either abdominoplasty and lipoabdominoplasty. METHODS: The sample consisted of 41 female patients, who were divided into three groups and underwent one of the following procedures: group A (n=21), abdominoplasty and group B (n=20), lipoabdominoplasty. In order to investigate seroma formation, abdominal ultrasound was performed in 5 regions of the abdominal wall [epigastrium (EPI), umbilical (UMB), hypogastrium (HYPO), right iliac fossa (RIF) and left iliac fossa (LIF)], at two postoperative periods: (P1), between postoperative days 11 and 14, and (P2), between postoperative days 18 and 21. RESULTS: The rate of seroma formation at both P1 and P2 was significantly higher in group A than in group B. It was observed that, in group A at P1, the regions RIF and LIF developed larger fluid collections. In group B, there were significantly larger fluid collections in the HYPO region at P1, and in the UMB and HYPO regions at P2. CONCLUSION: Lipoabdominoplasty is effective technique for the prevention of seroma compared with abdominoplasty.INTRODUÇÃO: O seroma é uma das complicações mais frequentes nas abdominoplastias. OBJETIVO: Comparar a incidência de seroma em pacientes submetidos à abdominoplastia convencional e à lipoabdominoplastia. MÉTODO: Foram estudadas 41 pacientes, divididas em dois grupos: Grupo A (21 pacientes submetidas à abdominoplastia convencional e Grupo B (20 pacientes submetidas à lipoabdominoplastia). Para a investigação da formação de seroma foi realizado ultrassonografia de cinco regiões da parede abdominal (epigástrio (EPI), umbilical (UMB), hipogástrio (HIPO), fossa ilíaca direita (FID) e fossa ilíaca esquerda (FIE)) em dois momentos: entre o 11º e o 14º dia de pós-operatório (DPO) (P1) e entre o 18º e 21º DPO (P2). RESULTADOS: A incidência de seroma tanto em P1 quanto em P2 foi significativamente maior no grupo A que no grupo B. Observou-se que no grupo A, no P1, as regiões FID e FIE apresentaram maior incidência de coleções fluidas. No grupo B, houve uma maior incidência de coleções fluidas na região HIPO em P1 e nas regiões UMB e HIPO em P2. CONCLUSÃO: Houve menor incidência de seroma nos pacientes submetidos à lipoabdominoplastia em relação à abdominoplastia convencional nos momentos estudados.SBCPUNIFESP-EPMUNIFESP-EPM Setor de Deformidades da Parede Abdominal da Disciplina de Cirurgia PlásticaUniversidade de Santo AmaroUNIFESP-EPM Departamento de CirurgiaUNIFESP-EPM Programa Pós-Graduação em Cirurgia PlásticaUNIFESP, EPM, Setor de Deformidades da Parede Abdominal da Disciplina de Cirurgia PlásticaUNIFESP, EPM Depto. de CirurgiaUNIFESP, EPM Programa Pós-Graduação em Cirurgia PlásticaSciEL