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Over the past several years, Pechiney has launched intensive R&D activities, in close connection with its main customers, aimed at tailoring property balances to specific applications and at reducing the overall cost of manufactured aircraft parts. These close partnerships led to the development of a number of new alloys and tempers covering all the major aircraft structural parts, all of them bringing benefits in one or more design properties, and all of them having being chosen for new aircraft. Similarly, new special qualities were designed to reduce customer costs: low residual stress, high formability, age formable and weldable solutions were developed and chosen for their efficiency in lean manufacturing. It is the purpose of this paper to review these cost reduction and weight saving initiatives conducted by Pechiney. The main design property improvements for the newly developed alloys and tempers and practical applications of the special material qualities will be reported. In addition, the underlying metallurgical principles of the performance improvements will be discussed.

The purpose of this paper is to formulate an algorithm for a novel damage‐coupled material law for crystalline polyethylene at finite inelastic strains followed by investigation of the influence of the aggregate representation and material parameters on the material response.

The constitutive equations are developed within the framework of continuum damage mechanics to describe crystal fragmentation caused by atomic debonding of the crystallographic planes. The material is assumed initially isotropic and homogeneous and is represented as an aggregate of randomly oriented crystals with an orthorhombic lattice. For the velocity gradient, an additive decomposition into symmetric and skew‐symmetric components is applied, where the skew‐symmetric part (spin) is decoupled from the lattice shear by means of a damage variable. Structural features such as lattice parameters and orientations, slip systems, and kinematic constraints are incorpo‐rated.

The proposed model is implemented to predict stress‐strain behaviour under uniaxial tension and damage accumulation and texture development at the different stages of deformation. In the numerical examples, the effects of the aggregate size, crystal orientations, and material parameters on the model estimates are analyzed.

The model used herein is a first attempt to analyze the influence of crystal fragmentation caused by the debonding of the crystallographic planes on the predicted mechanical behaviour and texture development of polyethylene prior to failure.

The purpose of this paper is to provide a computational procedure for a novel damage‐coupled material law for semicrystalline polyethylene. Using a damage mechanics approach, the model seeks to gain insight into the mechanical behaviour of polyethylene considering the microstructure and degradation processes occurring under uniaxial tension.

The material morphology is modelled as a collection of inclusions. Each inclusion consists of crystalline material lying in a thin lamella attached to an amorphous layer. The interface region interconnecting the two phases is the plane through which loads are carried and transferred by the tie molecules. It is assumed that the constitutive model contains complete information about the mechanical behaviour and degradation processes of each constituent. After modelling the two phases independently, the inclusion behaviour is found by applying some compatibility and equilibrium restrictions along the interface plane.

The model provides a rational representation of the damage process of the intermolecular bonds holding crystals and of the tie‐molecules connecting neighbouring crystallites. The model is also used to analyze the degree of relationship between some of the material properties and the mechanical responses.

In practice, the numerical model clearly helps to understand the influence of the different microstructure properties on the tensile mechanical behaviour of semicrystalline polyethylene – an issue of particular interest in improving material processability and product performance.

To the authors’ knowledge, a phenomenon such as microstructural degradation of polyethylene has not received much attention in the literature. The proposed model successfully captures aspects of the material behaviour considering crystal fragmentation and tie‐molecule rupture.

This paper aims to shed light on the spatial constraints of sex work in Greece. The objective is twofold: to illustrate the intertemporal stance of the Greek state to push sex work at the edge of both the city and the law produces sex workers as always already marginal subjects and to identify how a spatial-based understanding of sex work could help in acknowledging sex workers’ full community citizenship.

This article examines the legal geographies of sex work in modern and contemporary Greece. The author is a doctoral student in critical jurisprudence with a professional background in urban planning law, who also works voluntarily with Athens-based sex worker’s organizations. Law’s materialization within space (Bennet and Layard, 2015, p. 406), namely, the implication of law in the discursive and material production of place, is examined through archival research with primary and secondary sources, including legislations and LGBT publications such as Amfi and Kráximo from the 1980s and 1990s found in the Archives of Contemporary Social History (ASKI) in Athens. Additionally, as the author is currently conducting fieldwork with people who are working or have worked in the past in sex in Greece as a part of her PhD dissertation, the paper contains data provided by ten interlocutors to highlight their own personal experience. The researcher has used the critical oral history method, as it is committed to recording first-hand knowledge of experiences of marginalized community members who are often unheard or untold, with the additional goals of contextualizing these stories to reveal power differences and inequities (Lemley, 2017, Rickard, 2003).

The paper provides insight into how regulationism establishes the brothel – a metonymy of prostitution – as a heterotopia within the urban space. Contemporary approaches, such as LULUs and broken window policies, are used to indicate the historically marginal placement of sex work.

The interviews presented here were conducted in the summer of 2022, in the context of the author’s PhD research. Despite her six years of activist-level involvement with sex workers’ rights organizations, due to ethical constraints, only the findings of interviews conducted up to the writing of this paper are presented here, while details of private discussions with members of these organizations are omitted.

The paper examines a significant and timely matter of place making and spatial justice. Unlike earlier research on prostitution in Greece that focused on the brothel either as a heterotopia or as an undesirable land use, the novelty of this paper is that it highlights the intersections between policing, planning, public hygiene, anti-immigration policies around the regulation of the sex market. By critically discussing the implications of the de facto illegality of sex work in Greece, the study highlights the importance of including the voices of sex workers in decision-making and contributes to the debate around the decriminalization of sex work in Greece.

Coronavirus disease 2019 (COVID-19) outbreak has impacted catastrophically every sector of the economy throughout the world. And, the education sector is not leftover from the devastating effects of lockdown, especially in South Asia. It has led to the prolonged closure of schools/universities, subsequently, traditional teaching expeditiously transformed into online teaching. In the light of the events, this study is pertinent to examine teachers’ perceptions of online teaching and the obstacles they face in online teaching during this pandemic.

The research takes a quantitative and sample survey approach. A Google Form Questionnaire was used to obtain a sample of 200 Delhi school teachers in March and April 2021. Data were analyzed in SPSS by using Descriptive Statistics, Factor Analysis, Reliability and Chi-Square test, etc.

The result of the study indicates that on average, teachers have a positive perception about virtual teaching amid COVID-19 for reducing the learning gap and shaping pupils’ future during the crisis. Nevertheless, they encountered several obstacles in online teaching such as technical obstacles, difficulties in online exams and assessment, etc.

The findings of this study would persuade educational institutions and policymakers for enhancing the quality of online teaching by embracing the newest instructional strategies and providing continuous training to teachers.

Several studies described obstacles confronted by instructors in virtual teaching in higher education during the Coronavirus while disregarding the perception and challenges of school teachers toward e-learning in an ongoing outbreak. The present study replenishes this gap.

The rapid expansion of online education in the 21st century, driven by technological advancements and the COVID-19 pandemic, has highlighted the critical role of massive open online courses (MOOCs) in higher education. This study aims to investigate student satisfaction with the instructional design of MOOCs at a private university in Vietnam.

This mixed-methods research integrates quantitative data from a survey of 225 students with qualitative insights from interviews with 10 students. The study examines key determinants of student satisfaction, including course content, instructional methodologies, assessment systems, engagement in discussion forums and the overall online learning environment.

The findings reveal high levels of student satisfaction with the quality of course materials, the flexibility of the platform and the usability of the interface. However, areas of dissatisfaction include limited interactive engagement, inadequate motivational elements, suboptimal assessment strategies and insufficient staff support. The study underscores the need for comprehensive instructor evaluations, increased student-instructor interactions, improved plagiarism detection mechanisms and timely academic support to enhance the instructional design and educational outcomes of MOOCs.

This study provides a nuanced understanding of student satisfaction with MOOCs, specifically within the context of a private university in Vietnam. By integrating both quantitative and qualitative data, the research offers valuable insights into specific elements that contribute to or detract from learner satisfaction. These findings can inform practical enhancements in MOOC design and delivery, ultimately aiming to improve educational outcomes in online learning environments.