Search results for "Dislocation"

Effect of plastic deformation on photoluminescence of ZnTe bulk monocrystals

1999

Abstract In this work ZnTe bulk single crystals have been deformed by axial compression with the aim of analyzing the luminescence properties related to intrinsic structural defects like dislocations. Plastic deformation greatly decreases the overall PL response, near-band-edge luminescence as well as deep level-related emissions. Results indicate a close relationship between the so-called Y1 and Y2 bands and the density of generated dislocations. Plastic deformation also produces an emission band at 603 nm whose intensity is proportional to the amount of introduced deformation.

A physical-based constitutive model for surface integrity prediction in machining of OFHC copper

2017

International audience; Due to the rising interest in predicting machined surface integrity and sustainability, various models for metal cutting simulation have been developed. However, their accuracy depends deeply on the physical description of the machining process. This study aims to develop an orthogonal cutting model for surface integrity prediction, which includes a physical-based constitutive model of Oxygen Free High Conductivity (OFHC) copper. This constitutive model incorporates the effects of the state of stress and microstructure on the work material behavior, as well as a dislocation density-based model for surface integrity prediction. The coefficients of the constitutive mod…

Influence of M23C6 carbides on the heterogeneous strain development in annealed 420 stainless steel

2020

Understanding the local strain enhancement and lattice distortion resulting from different microstructure features in metal alloys is crucial in many engineering processes. The development of heterogeneous strain not only plays an important role in the work hardening of the material but also in other processes such as recrystallization and damage inheritance and fracture. Isolating the contribution of precipitates to the development of heterogeneous strain can be challenging due to the presence of grain boundaries or other microstructure features that might cause ambiguous interpretation. In this work a statistical analysis of local strains measured by electron back scatter diffraction and …

<title>Effect of light exposure on dislocation mobility in fullerite C60 crystals</title>

2001

The illumination-time evolution and the wavelength dependence of the photoinduced changes in dislocation mobility on the (111) face of C60 single crystals in air for the wavelength range 150 - 900 nm and power densities 0.2 - 2 mW/cm2 has been investigated. The results show that the light exposure in air leads to the decrease of the dislocation mobility. The magnitude of the effect as a function of the illumination time was investigated and a two-stage relationship was obtained. The ultraviolet light was found to be more effective than the visible light in the photoinduced reduction of dislocation mobility and solubility. In the wavelength range of 150 - 700 nm, the reduction of dislocation…

Children's exploration of the concepts of home and belonging: Capturing views from five European countries.

2021

Understanding one's sense of belonging is a central part of identity formation and self-awareness; feeling safe somewhere, with specific people is identified as a basic human need. This paper explores the ideas of children from three age groups in five different European as they discussed the concepts of ‘home’ and ‘belonging’. Findings showed that the children's ideas could be organised into six interrelated aspects: Spatiality, Materiality, Multiplicity, Social Relations, Affect, and Dislocation. Whilst there were differences in the ways that the children conceptualised home across the classes, even the youngest children were able to describe their ideas using metaphors and abstract conce…

La dislocation en français parlé en relation avec le contexte

1999

Modification of the Structure and Nano-Mechanical Properties of LiF Crystals Under Irradiation with Swift Heavy Ions

2011

The modifications of the structure and hardness of LiF crystals under high-fluence irradiation with MeV- and GeV-energy Au ions have been studied using nanoindentation and atomic force microscopy. The formation of ion-induced dislocations and bulk nanostructures consisting of grains with nanoscale dimensions (50 nm - 100 nm) has been observed. The structural modifications are accompanied by a strong ion-induced hardening which is related to dislocation impeding by assemblies of defect aggregates, dislocation loops of vacancy and interstitial types and grain boundaries. For MeV ions, the modifications are localized in a thin surface layer (few mm) where much higher density of deposited energ…

Medical news from scientific analysis of the Turin Shroud

2015

This paper synthetizes a series of works recently published in reference to medical studies regarding both the physical conditions of the Man who was wrapped in the Turin Shroud (TS) and the tortures to which this Man was subjected. An event that influenced the rapid course of the Passion and the cause of death of the TS Man was the fall under the weight of the cross. This Man shows, on the right side, shoulder lowering, flat hand and henophthalmos, revealing a violent blunt trauma, from behind, to neck, chest and shoulder, with the entire brachial plexus injury and muscular damage to the neck bottom with the head bent forward and turned to the left, on the cross, as he had a stiff neck. Mo…

Transverse fracture-dislocation of the sacrum: a diagnostic pitfall and a surgical challenge.

2002

Transverse fracture-dislocations of the sacrum are rare. Associated lesions of the lumbosacral spine as well as neurological injuries are common. Conventional radiographs of the pelvis often fail to clearly visualize the fracture. Delayed diagnosis increases the risk of progressive neurological disfunction. True lateral sacral views and CT-scans with 3-dimensional reconstructions are very helpful in establishing the full extent of the injury. These examinations should be considered in all patients with a history of high energy trauma and clinical signs indicating lumbosacral injury, such as severe low back pain and neurological disturbances of the lower extremities. The management of transv…

Cementless total hip replacement with subtrochanteric femoral shortening for severe developmental dysplasia of the hip.

2003

Total joint replacement in patients suffering from developmental dysplasia of the hip poses specific technical difficulties due to insufficient bone stock at the site of the original and secondary acetabulum and a narrow, cranially displaced proximal femur. Twelve hips with severe congenital dislocation (4 Crowe type II, 5 type III, 3 type IV) were treated with cementless, porous structured total hip replacement. The cup was implanted at the anatomic height, a femoral segment was resected below the minor trochanter to reduce the femoral component in all cases. One femoral component was exchanged for a longer stem after 2 months due to insufficient fit and fill. After a mean follow-up of 5.1…