396 research outputs found

    Design of an Experimental Setup for Testing Multiphysical Effects on High Speed Mini Rotors

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    Recently, there have been numerous research projects on the development of minirotating machines. These machines mostly operate at speeds above the first critical speed and have special levitation systems. Besides, the multiphysical effects become significant in small scale. Therefore, advanced modeling approaches should be developed and innovative experimental rigs with the foregoing requirements should be constructed in order to test the developed techniques. In the current study, the design of an experimental setup for testing the multiphysical effects has been outlined. First, the previously developed multiphysical models (Dikmen, E., van der Hoogt, P., de Boer, A., and Aarts, R., 2010, “Influence of Multiphysical Effects on the Dynamics of High Speed Minirotors—Part I: Theory,” J. Vibr. Acoust., 132, p. 031010; Dikmen, E., van der Hoogt, P., de Boer, A., and Aarts, R., 2010, “Influence of Multiphysical Effects on the Dynamics of High Speed Minirotors—Part II: Results,” J. Vibr. Acoust., 132, p. 031011) for the analysis of small scale rotors are described briefly for background information. Second, an analysis of the effect of the rotor parameters (diameter, length, rotation speed, etc.) on the dynamics of the rotor under multiphysical effects is presented. Afterward the design process which includes the design decisions based on these results, the availability, simplicity, and applicability of each component is presented in detail. Finally, the experimental results have been presented and the efficiency of the design has been evaluated. In summary, the design requirements for an experimental setup for testing multiphysical effects on minirotors have been analyzed. The design procedure and evaluation of the design have been presented

    Rates of depressive and anxiety symptoms in the perinatal period during the COVID-19 pandemic: Comparisons between countries and with pre-pandemic data

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    Background: The COVID-19 pandemic was a significant threat to perinatal mental health. This study examined differences in clinically significant depression, anxiety, and co-morbid symptoms among pregnant and postpartum women across several countries and compared prevalence of perinatal depression and anxiety before and during the pandemic in each participating country. Methods: Participants were 3326 pregnant and 3939 postpartum women (up to six months postpartum) living in Brazil, Chile, Cyprus, Greece, Israel, Portugal, Spain, Turkey, and the United Kingdom. An online survey was completed between June 7th and October 31st 2020, and included the Edinburgh Postnatal Depression Scale (EPDS) and the Generalized Anxiety Disorder Screener (GAD-7). The pre-pandemic studies were identified through literature review. Results: Prevalence of clinically significant depression (EPDS≥13), anxiety (GAD-7 ≥ 10), and co-morbid (EPDS≥13 and GAD-7 ≥ 10) symptoms was 26.7 %, 20 % and 15.2 %, in pregnant women, and 32.7 %, 26.6 % and 20.3 %, in postpartum women, respectively. Significant between-country differences were found in all mental health indicators in both perinatal periods. Higher levels of symptoms were observed during (versus before) the pandemic, especially among postpartum women. Limitations: Participants were mostly highly educated and cohabiting with a partner. The online nature of the survey may have limited the participation of women from vulnerable socio-economically backgrounds. Conclusions: Our findings expand previous literature on the negative impact of the COVID-19 pandemic on perinatal mental health, by highlighting that this may be influenced by country of residence. Mental health care policies and interventions should consider the unique needs of perinatal women in different parts of the world. © 2022Funding text 1: Sara Cruz acknowledges the Centro de Investigação em Psicologia para o Desenvolvimento (CIPD) [The Psychology for Positive Development Research Center] ( UID/PSI/04375 ), Lusíada University North, Porto, supported by national funds through the Portuguese Foundation for Science and Technology , I.P., and the Portuguese Ministry of Science, Technology and Higher Education ( UID/PSI/04375/2019 ).; Funding text 2: This paper is part of the COST Action Riseup-PPD CA18138 and was supported by COST under COST Action Riseup-PPD CA18138 . ; Funding text 3: Vera Mateus received financial support from CAPES /PrInt grant no. 88887.583508/2020-00 . ; Funding text 4: Raquel Costa was supported by the FSE and FCT under the Post-Doctoral Grant SFRH/BPD/117597/2016 [RC]. EPIUnit, ITR, and HEI-lab are supported by national funds through the Portuguese Foundation for Science and Technology , I.P., under the projects UIDB/04750/2020 , LA/P/0064/2020 , and UIDB/05380/2020 , respectively. ; Funding text 5: This publication is based upon work from COST Action 18138 - Research Innovation and Sustainable Pan-European Network in Peripartum Depression Disorder (Riseup-PPD), supported by COST (European Cooperation in Science and Technology). www.cost.eu . ; Funding text 6: Ana Osório received financial support from CAPES PROEX grant no. 0426/2021 , process no. 23038.006837/2021-73, CAPES /PrInt grant no. 88887.310343/2018-00 and MackPesquisa Fund . ; Funding text 7: Rena Bina received financial support from the Bar-Ilan Dangoor Centre for Personalized Medicine , grant no. REFU/DANGO/100. ; Funding text 8: This publication is based upon work from COST Action 18138 - Research Innovation and Sustainable Pan-European Network in Peripartum Depression Disorder (Riseup-PPD), supported by COST (European Cooperation in Science and Technology). www.cost.eu.Vera Mateus received financial support from CAPES/PrInt grant no. 88887.583508/2020-00.Ana Osório received financial support from CAPES PROEX grant no. 0426/2021, process no. 23038.006837/2021-73, CAPES/PrInt grant no. 88887.310343/2018-00 and MackPesquisa Fund.Rena Bina received financial support from the Bar-Ilan Dangoor Centre for Personalized Medicine, grant no. REFU/DANGO/100.Raquel Costa was supported by the FSE and FCT under the Post-Doctoral Grant SFRH/BPD/117597/2016 [RC]. EPIUnit, ITR, and HEI-lab are supported by national funds through the Portuguese Foundation for Science and Technology, I.P., under the projects UIDB/04750/2020, LA/P/0064/2020, and UIDB/05380/2020, respectively.This paper is part of the COST Action Riseup-PPD CA18138 and was supported by COST under COST Action Riseup-PPD CA18138. The authors would like to thank all women who participated in the survey. Sara Cruz acknowledges the Centro de Investigação em Psicologia para o Desenvolvimento (CIPD) [The Psychology for Positive Development Research Center] (UID/PSI/04375), Lusíada University North, Porto, supported by national funds through the Portuguese Foundation for Science and Technology, I.P. and the Portuguese Ministry of Science, Technology and Higher Education (UID/PSI/04375/2019)

    Piecewise linear asymptotic waveform evaluation for transient simulation of electronic circuits

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    A general purpose circuit simulation program, PL-AWE (piecewise linear asymptotic waveform evaluator) is developed especially for the analysis of VLSI circuits. PL-AWE uses the asymptotic waveform evaluation (AWE) technique, which is a new method to analyze linear(ized) circuits, and piecewise-linear (PL) models to represent nonlinear elements. AWE employs a form of Padeapproximation rather than numerical integration to approximate the behavior of linear(ized) circuits in either the time or the frequency domain. The authors discuss the internal workings of the program, and indicate its effectiveness in terms of several illustrative examples
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