Diagnosis and Therapy of Female Pelvic Organ Prolapse. Guideline of the DGGG, SGGG and OEGGG (S2e-Level, AWMF Registry Number 015/006, April 2016).

Aims: The aim was to establish an official interdisciplinary guideline, published and coordinated by the German Society of Gynecology and Obstetrics (DGGG). The guideline was developed for use in German-speaking countries. In addition to the Germany Society of Gynecology and Obstetrics, the guideline has also been approved by the Swiss Society of Gynecology and Obstetrics (SGGG) and the Austrian Society of Gynecology and Obstetrics (OEGGG). This is a guideline published and coordinated by the DGGG. The aim is to provide evidence-based recommendations obtained by evaluating the relevant literature for the diagnostic, conservative and surgical treatment of women with female pelvic organ prolapse with or without stress incontinence. Methods: We conducted a systematic review together with a synthesis of data and meta-analyses, where feasible. MEDLINE, Embase, Cinahl, Pedro and the Cochrane Register were searched for relevant articles. Reference lists were hand-searched, as were the abstracts of the Annual Meetings of the International Continence Society and the International Urogynecological Association. We included only abstracts of randomized controlled trials that were presented and discussed in podium sessions. We assessed original data on surgical procedures published since 2008 with a minimum follow-up time of at least 12 months. If the studies included descriptions of perioperative complications, this minimum follow-up period did not apply. Recommendations: The guideline encompasses recommendations for the diagnosis and treatment of female pelvic organ prolapse. Recommendations for anterior, posterior and apical pelvic organ prolapse with or without concomitant stress urinary incontinence, uterine preservation options, and the pros and cons of mesh placements during surgery for pelvic organ prolapse are presented. The recommendations are based on an extensive and systematic review and evaluation of the current literature and include the experiences and specific conditions in Germany, Austria and Switzerland

Techniques for modelling microstructure in metal forming processes

This chapter discusses several types of numerical models for metallurgical evolution. First, some basic notions of microstructure representations and microstructure state variables, some features of hardening and recovery and some features of recrystallization are recalled. Then, constitutive models coupled with state variables are introduced and examples of applications are given. Mean field methods are also presented and applied to necklace structures produced in discontinuous dynamic recrystallization. Finally, future trends are described, with an emphasis on digital material models and how they will provide powerful models of recrystallization on the microscopic scale. © 2012 Woodhead Publishing Limited. All rights reserved

Superplastic behavior of a fine-grained Mg−Gd−Y−Ag alloy processed by equal channel angular pressing

An extruded Mg−6Gd−3Y−1.5Ag (wt%) alloy was processed by 6 passes of equal channel angular pressing (ECAP) at 553 K using route Bc to refine the microstructure. Electron back-scattered diffraction (EBSD) analysis showed a fully recrystallized microstructure for the extruded alloy with a mean grain size of 8.6 µm. The microstructure of the ECAP-processed alloy was uniformly refined through dynamic recrystallization (DRX). This microstructure contained fine grains with an average size of 1.3 µm, a high fraction of high angle grain boundaries (HAGBs), and nano-sized Mg5Gd-type particles at the boundaries of the DRXed grains, detected by transmission electron microscopy (TEM). High-temperature shear punch testing (SPT) was used to evaluate the superplastic behavior of both the extruded and ECAP-processed alloys by measuring the strain rate sensitivity (SRS) index (m-value). While the highest m-value for the extruded alloy was measured to be 0.24 at 673 K, the ECAP-processed alloy exhibited much higher m-values of 0.41 and 0.52 at 598 and 623 K, respectively, delineating the occurrence of superplastic flow. Based on the calculated average activation energy of 118 kJ mol−1 and m-values close to 0.5, the deformation mechanism for superplastic flow at the temperatures of 598 and 623 K for the ECAP-processed alloys was recognized to be grain boundary sliding (GBS) assisted by grain boundary diffusion

On the sluggish recrystallization of a cold-rolled Al–Mn–Fe–Si alloy

Annealing of supersaturated AA3xxx alloys at low temperatures usually results in sluggish recrystallization kinetics. This is due to the joint effect of the following factors: low nucleation rate, reduced grain boundary mobility, and large amount of fine precipitates (dispersoids). In this paper, samples of Al–Mn–Fe–Si alloy were appropriately homogenized in different conditions to produce different microchemistries before deformation, i.e. solutes and second-phase particles. The sluggish recrystallization behaviour of these cold-rolled Al–Mn–Fe–Si samples annealed in three different conditions was then investigated, the first condition being recrystallization without precipitation, followed by recrystallization and precipitation occurring concurrently, and finally precipitation occurring before recrystallization. The results clearly show that in all these conditions, an incubation time is involved, which decreases with increasing annealing temperature and cold deformation, as well as with decreasing solute amount. Qualitative analysis of the microstructure evolution after a sudden increase of annealing temperature suggests that the effective retarding force from solute and/or particles decreases at higher temperatures. When recrystallization occurs concurrently with precipitation, the growth of successful nuclei can still be suppressed by concurrent precipitation

Identification of cyclic and anisotropic behaviour of ODS steels tubes

In this paper, an elastic plastic behaviour model based on internal state variables is investigated. The final aim is to describe the mechanical stress-strain cyclic response of oxide dispersion strengthened (ODS) steels during the cold pilgering process. In this tube forming operation, a material element undergoes a series of small incremental deformations, alternatively under tensile and compressive stresses. The cyclic model considers isotropic hardening and kinematic hardening which can be related to the typical continuous cyclic softening of the ODS steels. Moreover, the identification process of the cyclic model parameters involves experimental data from only one sample. ODS steels tubes usually reveal an anisotropic strength in the radial, ortho-radial and longitudinal directions due to a crystallographic and strongly elongated grain morphology in the rolling direction. Identification of 3 Hill's parameters is done using compression tests of cylindrical specimens cut in three different directions (longitudinal, radial and ortho-radial) combined with an inverse analysis. © 2011 Published by Elsevier Ltd

Prediction of tantalum microstructure evolution during thermomechanical treatments using FEM calculations with a dislocation density based constitutive law

In this paper, the behaviour of the tantalum subjected to a complex range of thermomechanical solicitations is studied and modelled. The objective of this work is the prediction of microstructure evolution of a tantalum part that is cold flow-formed, then stress-relieved and softened by heat treatments. Flow forming is a cold chipless process that elongates and thins the wall of a tubular part by applying a free rotating roller on the wall of the rotating part. (See Figure 1) This process leads to large strain up to 5 and one material point may be deformed at a fluctuating strain rate. To model this process, it is thus recommended to use a constitutive law that takes into account the history of the material. Microstructure evolution is controlled through the whole process by monitoring the state variable, that is, the dislocation density, within a FEM code. The 3D FEM software FORGE2007® is used to model the entire process. The code is enhanced with physical constitutive laws relative to the tantalum and derived from works of Klepaczko and Buy et al. [1,2,3]. The formalism of Klepaczko and Buy et al. is useful since it is based on laws regulating physical mechanisms of dislocations multiplication, annihilation and kinetics of glide depending on strain rate and thermal activation. Static recovery is modelled subsequently with an incremental approach where the softening is related to the dislocation density evolution. A set of thermomechanical experiments and treatments are done to identify the constitutive law and associated microstructure evolution. Compression, dynamic and static torsion tests covering a wide range of strain rates are used to fit the mechanical constitutive law and the dislocation density evolution law both inspired from Klepaczko and Buy et al. works. The same samples are then annealed with variable temperatures and times. Microstructure of annealed samples is characterized by means of micro-hardness. They give information to evaluate the dislocation density evolution. The data is used to model static recovery.0

Competition between intragranular and intergranular deformation mechanisms in ODS ferritic steels during hot deformation at high strain rate

Oxide Dispersed Strengthened (ODS) ferritic stainless steels present well-known fine grains microstructures where dislocation movement is hindered by a dense precipitation of nano-oxides particles. Previous research, on the thermomechanical behavior at high temperature and strain rates, was focused on torsion tests (Karch in J Nucl Mater 459:53–61, 2014). Considering texture evolution and grain shape as indicators of the intragranular dislocation glide activity, it was shown that, for high temperature and strain rate, intragranular deformation was in competition with intergranular accommodation. The latter phenomenon was related to early damaging at grain boundaries. The occurrence of a transition phenomenon from an intragranular to an intergranular deformation mechanism, with increasing temperature, was recently confirmed by neutron diffraction spectroscopy (Stoica in Nature Commun 5:5178, 2014). In the present paper, hot extrusion (HE) tests are performed, avoiding damage due to the high stress triaxiality, and allowing further investigation of intragranular and intergranular plasticity at large strains. Three ferritic steels exhibiting various precipitation size anddensitywere hot extruded.Microstructure evolution at different stages of deformation is investigated using the Electron Back-Scattered Diffraction (EBSD) technique. After extrusion at 1373 K (1100°C), the microstructure of ODS steels consists of a mixture of small round shape grains and larger elongated grains containing low-angle grain boundaries. Texture measurements show the appearance of the a-fiber (\110[//extrusion direction) and an increase in its intensity during the extrusion process in the larger grains. The fragmentation of the large elongated grains by Continuous Dynamic Recrystallization (CDRX) partially occurs in ODS materials depending on precipitation reinforcement. For smaller grains, plastic deformation has no effect on crystallographic orientation and grain shape, indicating a grain boundary accommodation phenomenon as the major deformation mechanism. Precipitation density not only impacts the intragranular dislocation glide activity, but also reduces CDRX kinetics in coarse grains