Analytical Modelling of Electromagnetic Bulging of Thin Metallic Tubes

© 2021 The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. This is the accepted manuscript version of a conference paper which has been published in final form at https://doi.org/10.1007/978-981-15-9505-9_70The main objective of this paper is to develop an analytical method based on the energy balance equation to model the plastic deformation of thin metallic tubes in a high velocity forming process under axisymmetric conditions. A yield criterion is proposed, which involves the coupled effect of the axial and circumferential internal force resultants. Using a combination of power-law strain hardening and strain rate hardening flow stress models, both strain hardening and strain rate effects are included. The proposed method permits consideration of the influence of different terms of kinetic energy and plastic work of the tube. The study presents a typical electromagnetic tube expansion model, using a dynamic high strain-rate forming method with strain-rates above 103 s−1. In this process, the deformation of the workpiece is achieved by the interaction of a current generated in the workpiece with a magnetic field generated by a coil adjacent to the workpiece. The results reveal that the achieved high strain rates influence the plastic flow stress and the final permanent radial deformation, consequently. The study concluded that an appropriate shape function eventuates a more accurate estimation of both the radial displacement and the deformed meridian profile

ProductAE: Toward Deep Learning Driven Error-Correction Codes of Large Dimensions

While decades of theoretical research have led to the invention of several classes of error-correction codes, the design of such codes is an extremely challenging task, mostly driven by human ingenuity. Recent studies demonstrate that such designs can be effectively automated and accelerated via tools from machine learning (ML), thus enabling ML-driven classes of error-correction codes with promising performance gains compared to classical designs. A fundamental challenge, however, is that it is prohibitively complex, if not impossible, to design and train fully ML-driven encoder and decoder pairs for large code dimensions. In this paper, we propose Product Autoencoder (ProductAE) -- a computationally-efficient family of deep learning driven (encoder, decoder) pairs -- aimed at enabling the training of relatively large codes (both encoder and decoder) with a manageable training complexity. We build upon ideas from classical product codes and propose constructing large neural codes using smaller code components. ProductAE boils down the complex problem of training the encoder and decoder for a large code dimension $k$ and blocklength $n$ to less-complex sub-problems of training encoders and decoders for smaller dimensions and blocklengths. Our training results show successful training of ProductAEs of dimensions as large as $k = 300$ bits with meaningful performance gains compared to state-of-the-art classical and neural designs. Moreover, we demonstrate excellent robustness and adaptivity of ProductAEs to channel models different than the ones used for training.Comment: arXiv admin note: text overlap with arXiv:2110.0446

Development of an Affordable MGT-CHP for Domestic Applications

© 2023 The Editor(s) (if applicable) and The Author(s). This is an open access conference contribution distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/The micro gas turbine (MGT) is considered one of the main solutions for the future power generation system to provide secure and stable energy. Thanks to its multi-fuel capability and high values of power-to-weight ratio, it is a suitable candidate for many applications such as Combined Heat and Power (CHP) systems, range extenders, and auxiliary power units. Among these applications, the micro-CHP system benefits from both the electricity and exhaust heat of the MGT for household or industrial process applications. The MGT could be integrated with a heat exchanger to introduce a CHP boiler to the domestic boiler market. To reduce the cost and size of the package and to compete with a traditional boiler the simple Brayton cycle without the recuperator is considered and all of the useful energy in the exhaust gas is transferred to the heat exchanger to provide hot water. To further reduce the cost of the system to compete in the market, off-the-shelf components were adopted in this project. In this article, the development process of this product is presented including conceptual design based on the type and size of the market. It follows with an evaluation of off-the-shelf compressor and turbine modulus from the automotive turbochargers to match the operating conditions. Here, the MGT is designed in a way that can be adapted to the boilers with minimum components change. A high-speed alternator was powered with a tie grid drive/inverter to enable a bi-directional connection of the power unit to the network. A comparison between the product definition and experimental results of a demonstrator prototype is presented which reveals gaps between design and prototype outcomes. Analysis shows that 23% of the power degradation can be recovered by enhancing the cooling. Potential development and improvement scenarios are addressed for future development

Comprehensive Gene Expression Analysis of Human Embryonic Stem Cells during Differentiation into Neural Cells

Global gene expression analysis of human embryonic stem cells (hESCs) that differentiate into neural cells would help to further define the molecular mechanisms involved in neurogenesis in humans. We performed a comprehensive transcripteome analysis of hESC differentiation at three different stages: early neural differentiation, neural ectoderm, and differentiated neurons. We identified and validated time-dependent gene expression patterns and showed that the gene expression patterns reflect early ESC differentiation. Sets of genes are induced in primary ectodermal lineages and then in differentiated neurons, constituting consecutive waves of known and novel genes. Pathway analysis revealed dynamic expression patterns of members of several signaling pathways, including NOTCH, mTOR and Toll like receptors (TLR), during neural differentiation. An interaction network analysis revealed that the TGFβ family of genes, including LEFTY1, ID1 and ID2, are possible key players in the proliferation and maintenance of neural ectoderm. Collectively, these results enhance our understanding of the molecular dynamics underlying neural commitment and differentiation

Suicide attempts, suicide and their association with socio-demographic variables in Iran: a retrospective, registry-based, cohort study (2016-2021)

INTRODUCTION: Suicide is recognized as one of the most significant concerns in healthcare and a serious psychological health issue in many countries throughout the world. Suicide attempts occur in all social sectors and demographics. It is important to know what are the causes for people to try to commit suicide for an effective prevention and control. The aim of this review was to find out the levels and predictors of suicide attempts. MATERIAL AND METHODS: A cross-sectional descriptive-analytical research looked for suicide attempt reported cases at Dr. Moaven Hospital in Sahneh, Iran, during the 2016–2021 period. Data was collected via checklists completed by supervisors during referrals and subsequently analyzed using the SPSS Statistics software tool (version 24). Descriptive statistics and the Chi-square test were used. A significance threshold of 0.05 was used. RESULTS: A total of 1,059 cases of suicide attempts were found. The highest prevalence rate was reported in the group ages 16–25. Males had higher rates of cases (57.4%), which were twice more prevalent in cities and more common in lower-socioeconomic-status families Furthermore, the most common method used (79.5%) was medication intake. There was also a significant association between marital status, job, and suicide-attempt rates (p < 0.05). CONCLUSIONS: Suicide attempts are among the most important issues in terms of psychosocial healthcare in all countries and communities, and their prevalence rates may be determined by a variety of factors, such as mental health status, family and living conditions, financial problems and unemployment rate. Preventive control of these factors can contribute to reducing the prevalence of these acts

Proceedings of Abstracts, School of Physics, Engineering and Computer Science Research Conference 2022

© 2022 The Author(s). This is an open-access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For further details please see https://creativecommons.org/licenses/by/4.0/. Plenary by Prof. Timothy Foat, ‘Indoor dispersion at Dstl and its recent application to COVID-19 transmission’ is © Crown copyright (2022), Dstl. This material is licensed under the terms of the Open Government Licence except where otherwise stated. To view this licence, visit http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: [email protected] present proceedings record the abstracts submitted and accepted for presentation at SPECS 2022, the second edition of the School of Physics, Engineering and Computer Science Research Conference that took place online, the 12th April 2022

Nursing staff’s Understanding about risk factors for musculoskeletal disorders associated with carriage of patients in educational centers of Kermanshah University of Medical Sciences in 2017

Abstract Background & Aim: Musculoskeletal disorders associated with patient transport are one of the most common occupational diseases in nursing staff. The objective of this study was to determine the understanding of nursing staffs about the risk factors of musculoskeletal disorders associated with carriage of patients in educational centers of Kermanshah University of Medical Sciences in 2017. Methods & Materials: In this descriptive cross-sectional study, 270 nursing staff were studied in 2017. The sampling method was proportional in this stratified study. In order to assess nurses' understanding about the risk factors that cause the development of musculoskeletal disorders, a 17-item questionnaire, which was based on a survey of Nigerian nurses working on musculoskeletal disorders, was used. After entering the data in SPSS 21, descriptive and inferential statistics such as Chi-square, independent t-test, ANOVA and Pearson correlation coefficient were used to achieve the goals and to answer the research questions. Results: The average working hours per week was 14.44±13.17 hours. 53.7% of nursing staff had self-treatment due to work-related problems. The most painful organ of the nursing staff was the lower back (42.8%) and neck (20.4%). The understanding of the majority (85.6%) of nursing staff was minimal in relation to the risk factors for musculoskeletal disorders associated with carrying the patient. Work experience (P=0.031), work situation in the last 12 months (P=0.40) and job position (P=0.005) had a significant relationship with understanding. Conclusion: According to the results of this study, considering the musculoskeletal disorders related to patients’ carriage among the nursing staff, education and improvement of existing conditions were necessary in order to reduce and prevent these disorders

Papillary and peripapillary vascular densities and corresponding correlation with peripapillary retinal thicknesses using optical coherence tomography angiography in healthy children and adolescents

Abstract To evaluate the peripapillary retinal thickness (PPRT), vascular density (PPVD), and disc vascular density (PVD) and their correlations in normal healthy children using optical coherence tomography angiography (OCTA). This was a cross-sectional study of 70 eyes from 36 normal healthy children aged 6–18 years who performed optic nerve head scans using OCTA. The PPRT included the peripapillary nerve fiber layer (PP-RNFLT), inner retina (PP-IRT), middle retinal thickness, and outer retinal thicknesses. The PP-RNFLT and PP-IRT were not significantly different between males and females. Superior nasal peripapillary RNFLT and IRT were significantly affected by age (ANOVA, P > 0.05). The PP-IRT and PP-RNFLT were lower in the 7–11 years old group in comparison with the other 3 groups (Post hoc Tukey test, P value  0.05). PPRT was not correlated with PVD, PPVD, superficial and deep retinal vascular densities, and choroidal vascular density. This study demonstrated that PPRT appears to change during growth in childhood. Superior nasal PPRT was affected more in the groups, decreasing from less than 7 years old to 7–11 years old and then back to pre-reduction values after 11 years old

Poly(styrene-co-butyl acrylate)/Clay Nanocomposite Latexes Synthesized via In Situ Atom Transfer Radical Polymerization in Miniemulsion: Activators Generated by Electron Transfer Approach

W       ater born poly(styrene-butyl acrylate)/clay nanocomposite latexes were synthesized by a novel initiating system of activators generated by   electron transfer (AGET) in a system of atom transfer radical polymerization   (ATRP). Initially, the clay was swelled in a mixture of styrene, butyl acrylate,   and hexadecane. The mixture was then sonicated to obtain a stable miniemulsion. To   synthesize poly(styrene-butyl acrylate)/clay nanocomposite latexes, the reducing   agent (ascorbic acid) was added dropwise to the reactor (to reduce termination reactions).   Particle size and particle size distribution of resulting nanocomposite latexes   were determined by dynamic light scattering (DLS). These latex particles were produced   with diameters in the size range of 138-171 nm. In addition, the increase in   clay content led to increased particles size. Number and weight-average molecular   weights of the resultant copolymer nanocomposites and their molecular weight distributions   were determined by gel permeation chromatography. The narrow molecular   weight distribution of the nanocomposites is an indication of a successful ATRP   which was accomplished in miniemulsion formation. Using         1   H NMR, copolymers were characterized and the mol ratios of monomers in copolymer composition were   calculated. X-Ray diffraction and transmission electron microscopy results showed   the mixed intercalated and exfoliated morphologies of nanocomposites in which   homogeneous distributions of clay layers in the polymer matrix have been achieved