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Experimental test and PFC3D simulation of the effect of a hole on the tensile behavior of concrete : a comparative analysis of four different hole shapes
No full textIn this article, the effects of porosity and its geometry on tensile features of concrete were investigated, using the Brazilian test and three dimensions PFC model. In the first step, the PFC sample was calibrated by indirect tensile lab outcomes and uniaxial compression test outputs. In the next step, indirect tensile tests were done on the models consisting of various pore shapes. Cylindrical models consisted of internal pores with different shapes such as rectangular, circular, horizontal notch, and vertical notch. The diameter and or the length of these porosity changes in various values, i.e., 10 mm, 20 mm, and 30 mm. Twelve different configurations of samples were prepared by varying the porosity shapes. The mechanical behavior of samples has been provided in form of stress–strain curves at a constant and slow loading rate of 0.05 mm/min for ensuring the static condition based on Newton’s first law. Concurrent with numerical simulation, an experimental test was done on the concrete slabs containing different pores. The outcomes showed that porosity geometry plays an important role in the fracturing pattern. It was found that the porosity geometry has potent consequences on fracturing process stress and the value of the UCS for rocks. Numerical simulation shows that fracture energy decreased by increasing the dimension of the defect. Crack initiation stress was close to final stress in vertical notch configuration while the difference between the final stress and crack initiation stress has a high value for horizontal notch configuration. The sharper the hole tip, the faster the progressive failure occurred. © 2023 Taylor & Francis Group, LLC
Hope during COVID-19 : a poetic inquiry of early career academics
Get PDFThe COVID-19 pandemic continues to cause global upheaval. It had a significant impact on the field of education, with multiple lockdowns changing the nature of teaching. This has been particularly challenging for early career academics (ECA) who already experience heightened stresses in the field of academia. This article explores the impact of COVID-19 on three ECAs who are Health, Outdoor and Physical Education (HOPE) teacher educators. Using poetic inquiry, this article explores our experiences of teaching experiential content in an online environment during an extended lockdown. Engaging in this process highlighted the personal and professional challenges we faced, including work-life balance, teaching online, and staying up to date with research and leadership commitments. It also highlighted significant opportunities, including affirming good pedagogy and building a sense of community. Ultimately, engaging in this process highlighted a sense of hope and provided an opportunity for the three authors to grow as educators. © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Economic model predictive control for microgrid optimization : a review
Get PDFMicrogrids have emerged as a promising solution to integrate distributed energy resources (DERs) and supply reliable and efficient electricity. The operation of a microgrid involves the coordination of different DERs and loads. To date, various control methods have been developed to maximize the overall benefit while satisfying various constraints. Now it is urgently needed to understand and comprehend these approaches to further stimulate the deployment of microgrids. This paper presents an overview for researchers on economic model predictive control (EMPC) methods of microgrids to achieve a variety of objectives such as cost minimization and benefit maximization. The fundamental principle of the EMPC theory is explained in detail. The most popular and important strategies applied to stand-alone microgrids, grid-connected microgrids, residential smart homes, as well as networked microgrids are discussed. Future trends are also highlighted. © 2010-2012 IEEE
Advanced care directives in residential aged care for residents with major neuro-cognitive disorders (dementia) : a scoping Review
Get PDFThe aim of this review was to identify, assess, collate, and analyze existing research that has made a direct contribution to aiding understanding of the ethical and decision-making issues related to the use of advance care directives for people with dementia and/or other major neurocognitive disorders and/or their surrogate decision-makers on treatment. The Web of Science, Scopus, PubMed, CINAHL, Academic Search Ultimate, and MEDLINE databases were searched between August and September 2021 and July to November 2022 limited to primary studies written in English, Spanish, or Portuguese. Twenty-eight studies of varying quality that addressed related thematic areas were identified. These themes being support for autonomy in basic needs (16%), making decisions ahead/planning ahead and upholding these decisions (52%), and support in decision-making for carers (32%). Advance care directives are an important mechanism for documenting treatment preferences in patient care planning. However, the available literature on the topic is limited in both quantity and quality. Recommendations for practice include involving decision makers, promoting educational interventions, exploring how they are used and implemented, and promoting the active involvement of social workers within the healthcare team. © 2023 The Author(s). Published with license by Taylor & Francis Group, LLC
Animal models, pathogenesis, and potential treatment of thoracic aortic aneurysm
Get PDFThoracic aortic aneurysm (TAA) has a prevalence of 0.16–0.34% and an incidence of 7.6 per 100,000 person-years, accounting for 1–2% of all deaths in Western countries. Currently, no effective pharmacological therapies have been identified to slow TAA development and prevent TAA rupture. Large TAAs are treated with open surgical repair and less invasive thoracic endovascular aortic repair, both of which have high perioperative mortality risk. Therefore, there is an urgent medical need to identify the cellular and molecular mechanisms underlying TAA development and rupture to develop new therapies. In this review, we summarize animal TAA models including recent developments in porcine and zebrafish models: porcine models can assess new therapeutic devices or intervention strategies in a large mammal and zebrafish models can employ large-scale small-molecule suppressor screening in microwells. The second part of the review covers current views of TAA pathogenesis, derived from recent studies using these animal models, with a focus on the roles of the transforming growth factor-beta (TG
Dreaming of an indigenised Australia
Get PDFThis article offers a critical engagement with Billy Griffiths’s award-winning book Deep Time Dreaming: Uncovering Ancient Australia as a departure point towards uncovering and examining a significant tradition of Australian cultural reflection and interpretation it terms, following Anthony Moran, indigenising settler nationalism. Tracing the genealogy of the indigenising settler-nationalist tendencies that shape Deep Time Dreaming, and to which the text itself contributes, the article situates Griffiths’s contribution as a recent and notable exemplar of a longstanding historiographical tradition that responds to the continuing crisis of settler-national belonging and legitimacy by attempting to incorporate the historical depth of Indigenous occupation into its own national, nationalising narrative, and so to indigenise the settler nation itself. The tradition is not Griffiths’s alone. When read in the context of a broader indigenising settler-nationalist tradition, Griffiths’s approach is revealed as neither unusually problematic nor uniquely complicit in the dynamics the article draws attention to. On the contrary, the genealogical reading of Griffiths’s work I offer here is important precisely to the extent that it facilitates an understanding of the underlying tendencies towards settler indigenisation that continue to condition Australian settler-national/ist historiography, and culture at large. © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
DCCGAN based intrusion detection for detecting security threats in IoT
No full textInternet of things (IoT) consists of wired/wireless network, sensor, and actuator, where security is more important when more devices are connected to IoT. To increase more security in IoT devices, this manuscript proposes a dual-channel capsule generation adversarial network (DCCGAN) espoused intrusion detection scheme for detecting security threats in IoT network (DCCGAN-IDF-DST-IoT). Data are collected from MQTT-IoT-IDS2020 dataset and Bot-IoT dataset. Then, the data are fed to local least squares, which eradicate the redundancy and replace the missing value. The pre-processed dataset is supplied to fertile field optimisation algorithm (FFOA), which selects the relevant features. Then DCCGAN is used for classifying the data as normal or anomalous. The proposed technique is activated in Python language. The performance of proposed technique for MQTT-IoT-IDS2020 dataset attains 16.55%, 21.37%, 32.99%, 27.66%, 26.45%, 21.47% and 22.86% higher accuracy compared with the existing methods. Copyright © 2024 Inderscience Enterprises Ltd
High school students’ statistical literacy changes in a flipped classroom environment: a quasi-experimental study
Get PDFStatistics in the 2018 Vietnam General Education Curriculum for Mathematics is emphasized from Grade 2 to Grade 12, helping develop students’ competences and qualities. However, students still struggle to connect and apply statistical concepts to real-life situations. This study used a flipped classroom model to teach 10th-graders statistics to develop their statistical literacy. Using a quasi-experimental design, we evaluated how the students’ statistical literacy developed as they participated in the flipped classroom. The results show that the flipped classroom improves students’ statistical literacy. All four categories of statistical literacy increased statistically significantly, including graphical displays, measures of central tendency, measures of variability, and using statistical knowledge to solve problems. The results are explained by the opportunities embedded into the program. Time outside of class was used for the students to review content and access new concepts, along with questions to demonstrate their statistical knowledge and reveal shortcomings. The students spent the most of their interaction time in class on activities to understand concepts and applied them to real-life situations. Some lessons learned from the study are discussed
Fatigue crack growth in functionally graded materials using an adaptive phase field method with cycle jump scheme
No full textFunctionally graded materials provide versatility in adjusting the volume fractions of constituent materials to meet specific design requirements. However, this customization often introduces mode-mixity at the crack tip, posing challenges in predicting fracture under cyclic loading with discrete approaches and computationally expensive with conventional phase-field fracture models. To address these issues, this paper introduces an adaptive phase-field fracture formulation with cycle jump scheme to elegantly predict fatigue crack nucleation and growth in functionally graded materials. Within this framework, the effective properties at a point are estimated using the Mori–Tanaka homogenization scheme, while the crack growth due to cyclic load is captured by incorporating an additional fatigue degradation parameter. Moreover, the computational efficiency of the proposed framework is improved through an adaptive mesh refinement and explicit cycle jump scheme. The adaptive refinement scheme utilizes an error indicator derived from both the displacement solution and phase-field variable. The adaptive refinement scheme is integrated with efficient quadtree decomposition, which generates a hierarchical mesh structure. Hanging nodes resulting from the quadtree decomposition are efficiently handled using a polygonal finite element method. The proposed framework is validated against experimental and numerical results reported in the literature. Furthermore, we investigate the fatigue crack growth resistance across a broad range of material gradation directions, gaining valuable insights and identifying functionally graded materials with high fatigue resistance. © 2024 The Author
The role of pregnancy associated plasma protein-A in triple negative breast cancer : a promising target for achieving clinical benefits
Get PDFPregnancy associated plasma protein-A (PAPP-A) plays an integral role in breast cancer (BC), especially triple negative breast cancer (TNBC). This subtype accounts for the most aggressive BC, possesses high tumor heterogeneity, is least responsive to standard treatments and has the poorest clinical outcomes. There is a critical need to address the lack of effective targeted therapeutic options available. PAPP-A is a protein that is highly elevated during pregnancy. Frequently, higher PAPP-A expression is detected in tumors than in healthy tissues. The increase in expression coincides with increased rates of aggressive cancers. In BC, PAPP-A has been demonstrated to play a role in tumor initiation, progression, metastasis including epithelial-mesenchymal transition (EMT), as well as acting as a biomarker for predicting patient outcomes. In this review, we present the role of PAPP-A, with specific focus on TNBC. The structure and function of PAPP-A, belonging to the pappalysin subfamily, and its proteolytic activity are assessed. We highlight the link of BC and PAPP-A with respect to the IGFBP/IGF axis, EMT, the window of susceptibility and the impact of pregnancy. Importantly, the relevance of PAPP-A as a TNBC clinical marker is reviewed and its influence on immune-related pathways are explored. The relationship and mechanisms involving PAPP-A reveal the potential for more treatment options that can lead to successful immunotherapeutic targets and the ability to assist with better predicting clinical outcomes in TNBC. © The Author(s) 2024