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Strain hardening and microstructure evolution in ECAP-processed ultrafine-grained metals: a comparative study of copper, aluminum, and magnesium alloys
No full textThis study presents a comparative analysis of texture evolution, deformation mechanisms, and dislocation density evolution in pure copper, Al-1100 alloy, and Mg AZ31 alloy subjected to equal-channel angular pressing (ECAP). For that purpose, a unique grain fragmentation model combining continuum dislocation dynamics with Taylor-Lin crystal plasticity is presented. Copper and aluminum alloys, with their face-centered cubic (FCC) crystal structures, exhibit similar micromechanical processes during grain fragmentation. The post-ECAP textures for both materials align with ideal orientations, indicating a rotation of grains around the center of the flow direction. On the other hand, the magnesium AZ31 alloy, with its hexagonal close-packed (HCP) crystal structure, displays a rolling-like texture. Al-1100 showed high dislocation multiplication rate favored by dislocation glide, while Mg AZ31 displayed slower dislocation density evolution at 200 °C which can be associated with dynamic recrystallization and twinning low activity. Indeed, driven by elevated temperatures, dynamic recrystallization could form new grains, resulting in a gradual increase in dislocation density. Furthermore, the comparison of average grain size reduction rates aligns with the dislocation density findings, with aluminum alloys experiencing significant grain fragmentation and Mg AZ31 alloy undergoing the slowest rate of grain fragmentation. The employed continuum dislocation dynamics (CDD) coupled with a crystal plasticity modeling approach enables the prediction of material responses, offering a powerful tool for understanding and optimizing deformation behavior. Further research opportunities lie in exploring additional factors and refining the understanding of deformation behavior in FCC and HCP materials, as well as expanding the applicability of the modeling approach to other materials and processing techniques. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature
Revoking the Exercised Termination of the Construction Contract: Implications and Lessons Learned
Get PDFThe decision to terminate the main construction contract by a project owner is a serious task that is normally approached with a great deal of caution and made almost invariably after seeking the appropriate legal advice. However, it is not a rare case that affected contractors find themselves in a position of attempting to have the exercised contract termination amicably revoked and the resumption of work on site reinstated. Whether such attempts eventually fail or succeed, major ramifications are likely to surface in administrating the propagation of the impacts of both main contract termination and its subsequent revocation on the subcontracts of the lower-tier project participants, i.e., subcontractors. This paper tackles this exact case, which involves the actions taken by the general contractor toward the subcontracts' works, first upon the termination of the main contract becoming effective and then upon having this owner's exercised termination successfully revoked. The methodology involved a number of steps. First, an analysis of the legal perspective on how the termination of the construction contract becomes effectively in place is carried out, using (1) a case law review of numerous industry-reported cases involving contract termination, and (2) a review of standard forms contracts. Second, an investigation of the viability and requirements for the possible annulment of contract termination, as stipulated under civil and common laws, is performed. Last, the details of a recent multinational contractor-subcontractor dispute are thoroughly studied, and lessons learned concerning the prevailed irreparable harm are deduced. The outcomes of the work shall be of value to project owners when deciding to revoke their exercised termination and to general contractors when deciding on the effective actions toward the subcontracts' works when such a revoking action becomes effective. © 2023 American Society of Civil Engineers
HUMAN-IN-THE-LOOP MACHINE LEARNING ARCHITECTURE FOR HIGH-RISK APPLICATIONS
No full textThe rise of Artificial Intelligence (AI) and Machine Learning (ML) has had a profound impact on various industries. As self-learning and autonomous systems are increasingly relied upon to make decisions, the safety and well-being of humans and society at large become more reliant on these technologies. In high-risk and safety-critical applications, such as the health industry and autonomous driving, incorrect predictions by AI can have disastrous consequences. It is therefore crucial to ensure the safe use of AI in these contexts. One way to address the challenges associated with machine learning for sensitive applications is to utilize a Human-In-The-Loop approach. By combining the strengths of AI and human expertise, this approach aims to minimize the burden on professionals while improving the reliability of the system. The core idea is to automate decision-making for the majority of instances, while flagging difficult-to-classify instances for human experts to evaluate. This approach not only reduces the burden on professionals but also ensures the safety and reliability of the system. In this paper, we present a novel two-layer Human-In-The-Loop architecture designed for sensitive applications. Our approach is based on the central principle of learning from mistakes to improve the reliability of the system. Specifically, we propose a model that can forecast the type and class of errors for future estimations improvement. We demonstrate the feasibility of our architecture by conducting an empirical study focused on two distinct applications: agitation detection in dementia patients, Arabic speech recognition. Our two-layer classification system aims to improve the overall performance of the classifier by increasing its sensitivity, while directing difficult-to-classify instances to human experts for further evaluation. Overall, our proposed architecture provides a promising solution for sensitive applications that require high levels of reliability and accuracy. By combining the strengths of AI and human expertise, we believe our approach can significantly improve the safety and well-being of individuals and society at large
The Arabic Hospital Anxiety and Depression Scale: validation in a sample of Lebanese patients with cancer
Get PDFBackground: Depression and anxiety are common comorbid psychological disorders among patients with cancer. Despite the wide use of the Arabic Hospital and Anxiety Scale (HADS) in oncological settings, it has not been yet validated among Lebanese patients with cancer. We aimed to assess the reliability and validity of the HADS in a sample of Lebanese patients with cancer. One-hundred one Lebanese patients diagnosed with cancer presenting to the Ambulatory Care Center in the Hematology Oncology Department at the American University of Beirut Medial Center filled the Arabic version of the HADS. The Generalized Anxiety Disorder 7-Item Scale (GAD-7) and the Patient Health Questionnaire 9-Item Scale (PHQ-9) were used to assess its concurrent validity in capturing anxiety and depression, respectively. Results: Reliability analysis using Cronbach’s alpha (α) coefficient revealed good internal consistency for the Arabic HADS (α = 0.89) and both subscales (α = 0.86 for depression and α = 0.78 for anxiety). Correlations between HADS with both GAD-7 and PHQ-9 were statistically significant and strong for both depression (r = 0.795; p < 0.0001) and anxiety (r = 0.727; p < 0.0001). Confirmatory factor analysis revealed that the observed data fits the two-factor model of depression and anxiety (Kaiser–Meyer–Olkin = 0.86; Tucker Lewis Index = 0.879; root-mean-square error of approximation = 0.08). Depression and anxiety rates were approximately 52% and 25%, respectively. Conclusion: We conclude that the Arabic version of the HADS is a credible and valid tool for clinical assessment of psychological distress (anxious and depressive states) among Lebanese patients with cancer. © 2023, Okasha Institute of Psychiatry, Ain Shams University
Breast cancer knowledge in Lebanese females with positive family history
Get PDFBreast cancer is the most commonly diagnosed cancer in women and the second leading cause of cancer-related death worldwide. Positive family history increases the likelihood of developing this disease. As late-stage presentation and poor survival rates are associated with a lack of knowledge about breast cancer and its screening methods, this study aimed to evaluate the knowledge of Lebanese women with first-degree relatives who were diagnosed with breast cancer. In this cross-sectional study, 200 women with a positive family history accompanying their relatives to oncology clinics or the infusion center at the American University of Beirut Medical Center, completed an online survey after institutional review board approval was granted. Demographic information and answers to questions related to breast cancer risk factors, warning signs, and screening techniques were collected and analyzed using descriptive statistics and chi-square tests. Eighty-one percent of the study participants agreed that a history of breast cancer is associated with a higher disease risk. The smaller portions were aware of other potential risk factors, such as hormone replacement therapy, alcohol consumption, late menopause, early menarche, and overweight and sedentary lifestyles. Also, 93% to 96.5% of the participants recognized breast self-examination and mammography as useful tools for early detection. Furthermore, younger participants who reached university level and were employed had more insights into breast cancer. Breast cancer knowledge and early diagnosis are key elements in preventing late presentations and reducing the associated morbidity and mortality. Further educational and awareness campaigns should be conducted in Lebanon to improve women knowledge of breast cancer. © 2023 Lippincott Williams and Wilkins. All rights reserved
Evaluation of an Autism Training in a Much-Needed Context: The Case of France
Get PDFBackground: Autistic people in France have called for community education to reduce autism stigma. As such, training is needed to help university students appreciate autistic peers and autistic people they may work with in their future careers. Methods: We adapted an autistic-affirming training from a training developed in other cultural contexts and evaluated it with 107 university students in France using a pretest-post-test design. Results: Questionnaire responses suggested that our brief online training helped improve attitudes toward inclusion, autism knowledge, and stigma among future educators and psychologists in France. Participants' open-ended definitions of autism revealed increased alignment with the neurodiversity movement after training. Conclusions: Findings suggest that wider-scale autistic-led adaptations of autism trainings like the one described in this report could begin to ameliorate autism stigma in France. © Copyright 2023, Mary Ann Liebert, Inc., publishers 2023
Analysis and Characterization of Pore System and Grain Sizes of Carbonate Rocks from Southern Lebanon
Get PDFCarbonate rocks are common in many parts of the world, including the Eastern Mediterranean, where they host significant groundwater supplies and are widely used as building and ornamental stones. The porosity of carbonate rocks plays a critical role in fluid storage and retrieval. The pore structure connectivity, in particular, controls many properties of geological formations, as well as the relationships between the properties of individual minerals and the bulk properties of the rock. To study the relationships between porosity, rock properties, pore structure, pore size, and their impact on reservoir characteristics, 46 carbonate rock samples were collected from four stratigraphic sections exposed near Sidon, South Lebanon. The studied carbonate rocks are related to marine deposits of different ages (e.g., Upper Cretaceous, Eocene, and Upper Miocene). In order to understand the pore connectivity, the MICP (mercury injection capillary pressure) technique was conducted on ten representative samples. Results from the SEM analysis indicate the dominance of very fine and fine pore sizes, with various categories ranging in diameter from 0.1 to10 µm. The MICP data revealed that the pore throat radii vary widely from 0.001 to 1.4 µm, and that all samples are dominated by micropore throats. The grain size analysis indicated that the studied rocks have significant amounts of silt- and clay-size grains with respect to the coarser ‘sand-size’ particles, suggesting a high proportion of microporosity. Obtained results, such as the poorly-sorted nature of grains, high microporosity, and the high percentage of micropore throats, justify the observed low mean hydraulic radius, the high entry pressure, and the very low permeability of the studied samples. These results suggest that the carbonate rocks near Sidon (south of Lebanon) are possibly classified as non-reservoir facies. © 2023, China University of Geosciences (Wuhan) and Springer-Verlag GmbH Germany, Part of Springer Nature
Outlooks on using a mobile health intervention for supportive pain management for children and adolescents with cancer: a qualitative study
Get PDFBackground: Considerable improvements in the prognosis of pediatric cancer patients have been achieved over recent decades due to advances in treatment. Nevertheless, as the most common and distressing health issue for pediatrics with cancer, cancer-related pain is still a significant hurdle that impedes patients’ journey to recovery, compromises their quality of life, and delays the positive outcome and effectiveness of their treatments. Purpose: Taking into consideration that acceptability studies are imperative for the design, evaluation, and implementation of healthcare interventions, this study aims to explore pediatric oncology patients’ readiness to use a mobile health application that emphasizes social assistance and peer support in addition to conventional pain management methods. Design and methods: This study followed the Qualitative description approach. Twelve participants were chosen based on purposive sampling and maximum variation sampling. Interviews were analyzed using the conventional content analysis. Results: Analysis of the interviews revealed four major categories: (A) The need for connectedness; (B) An innovative way to connect yet fearful; (C) A 3D approach; (D) Fears of the unfamiliar. Conclusions: This study is the first in Lebanon and the region to undertake an initiative towards introducing technology for pain assessment and management of children with cancer through a dedicated digital platform. The study results attested to the acceptability and potential utilization of this platform by children with cancer. Practice implications: Nurses need to be trained to play an essential role in teaching children with cancer about the significance of social support and assisting them to establish their social support network. Children with cancer are encouraged to voice out their need for help. Our proposed application can create an enabling environment to harness the power of social support and provide children with cancer the opportunity to connect on a deeper level in a supportive and pity-free space. © 2023, BioMed Central Ltd., part of Springer Nature
Art Therapy Interventions for Syrian Child and Adolescent Refugees: Enhancing Mental Well-being and Resilience
Get PDFPurpose of Review: This critical review primarily aims to conduct a comprehensive assessment of recent studies conducted within the past 3 years, with a specific focus on the use of art therapy within Syrian child and adolescent refugee populations. The central objective of this inquiry is to explore the impact of art therapy interventions and provide critical insights into their effectiveness in enhancing the mental well-being and resilience of these young refugees. Recent Findings: Recent research conducted within the past 3 years highlights the effectiveness of art therapy as an intervention strategy within Syrian child and adolescent refugee populations. These studies emphasize that art therapy offers a safe and supportive space for these young refugees to express emotions, process trauma, and improve their psychological well-being. It has shown promise in mitigating trauma-related challenges and fostering resilience among this group of refugee populations. Furthermore, art therapy plays a crucial role in preserving cultural identities and has proven to be versatile and adaptable to various artistic modalities. These findings underscore the potential of art therapy as a valuable tool for supporting the mental well-being and resilience of Syrian children and adolescent refugees, warranting further exploration and integration into their care and support programs. Summary: Recent studies on the use of art therapy within Syrian child and adolescent refugee communities reveal its potential as a powerful intervention strategy for enhancing mental well-being and resilience in this vulnerable population. The review identifies six key themes, highlighting the therapeutic benefits and versatility of art therapy. As we move forward, these findings offer promising future directions for research and practice in art therapy with this specific group of refugees, emphasizing the need for continued exploration and integration of this approach in supporting Syrian child and adolescent refugees. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature
New keratoconus staging system based on OCT
Get PDFPurpose:To establish a numerical spectral-domain optical coherence tomography (SD-OCT)-based keratoconus (KC) staging system and compare it with existing KC staging systems.Setting:Eye Hospital of Wenzhou Medical University, Wenzhou, China.Designs:Retrospective case-control study.Methods:Scheimpflug tomography, air-puff tonometry, and SD-OCT were performed on 236 normal and 331 KC eyes. All SD-OCT-derived parameters of the corneal epithelium and stroma were evaluated based on their receiver operating characteristic (ROC) curves, area under the curve (AUC), sensitivity, and specificity to discriminate between normal and KC eyes. The best performing parameters were subsequently used to create an OCT-based staging system, which was compared with existing tomographic and biomechanical staging systems.Results:236 eyes from 236 normal patients and 331 eyes from 331 KC patients of different stages were included. The highest ranked AUC ROC SD-OCT parameters, derived from stroma and epithelium, were stroma overall minimum thickness (ST: AUC 0.836, sensitivity 90%, specificity 67%) and epithelium overall SD (EP: AUC 0.835, sensitivity 75%, specificity 78%). A numerical SD-OCT staging system called STEP including 2 parameters - STand EP- with 5 stages was proposed.Conclusions:The new SD-OCT-based KC staging system is the first to take the epithelium with its sublayer stroma information into account, showing a strong agreement to the existing staging systems. This system could be incorporated into daily practice, potentially leading to an overall improvement in KC treatment and follow-up management. © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of ASCRS and ESCRS Published by Wolters Kluwer Health, Inc