Damage detection in truss structures using a flexibility based approach with noise influence consideration

Miguel, Leandro Fleck Fadel,Miguel, Leticia Fleck Fadel,Riera, Jorge Daniel,Menezes, Ruy Carlos Ramos De Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.27 No.5

The damage detection process may appear difficult to be implemented for truss structures because not all degrees of freedom in the numerical model can be experimentally measured. In this context, the damage locating vector (DLV) method, introduced by Bernal (2002), is a useful approach because it is effective when operating with an arbitrary number of sensors, a truncated modal basis and multiple damage scenarios, while keeping the calculation in a low level. In addition, the present paper also evaluates the noise influence on the accuracy of the DLV method. In order to verify the DLV behavior under different damages intensities and, mainly, in presence of measurement noise, a parametric study had been carried out. Different excitations as well as damage scenarios are numerically tested in a continuous Warren truss structure subjected to five noise levels with a set of limited measurement sensors. Besides this, it is proposed another way to determine the damage locating vectors in the DLV procedure. The idea is to contribute with an alternative option to solve the problem with a more widespread algebraic method. The original formulation via singular value decomposition (SVD) is replaced by a common solution of an eigenvector-eigenvalue problem. The final results show that the DLV method, enhanced with the alternative solution proposed in this paper, was able to correctly locate the damaged bars, using an output-only system identification procedure, even considering small intensities of damage and moderate noise levels.

Interventions on Well-being, Occupational Health, and Aging of Healthcare Workers: A Scoping Review of Systematic Reviews

Fadel Marc,Roquelaure Yves,Descatha Alexis 한국산업안전보건공단 산업안전보건연구원 2023 Safety and health at work Vol.14 No.1

Introduction: With recent higher awareness of the necessity of improving healthcare workers’ wellbeing, we aimed to overview systematic reviews dealing with interventions on well-being, occupational health, and aging of healthcare workers. Methods: From three databases (PubMed, Embase, and Web of Science), a scoping review of systematic reviews was carried out to determine current knowledge on interventions focused on the well-being or aging of healthcare workers. Only systematic reviews were considered, with appropriate extraction and quality evaluation. Results: Of the total of 445 references identified, 10 systematic reviews were included, mostly published since 2019. Nurses were the most frequent targets of interventions, and mental health was the main outcome described. The overall level of quality was also heterogenous, with high to low-quality reviews. Conclusions: Workers’ mental health well-being was the major outcome targeted by intervention, with varying level of evidence. Further studies are needed with integrative approaches on global health and life course perspectives, with a focus on the plurality of settings, worker types, and women.

Examination of an Algerian Clay in the Retention of Zinc Ions Charged in Brackish Water

Fadel, Ammar,Nacef, Saci The Korean Institute of Chemical Engineers 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.5

We studied the removal of zinc ions from synthetic brackish water by an adsorption method using natural Algerian Bentonite (NAB). The effect of the main physico chemical parameters-contact time, pH, temperature, ionic strength, clay weight and initial metal ion concentrations on the removal of $Zn^{+2}$-were investigated. The results showed that equilibrium was attained within 10 min of stirring time. The retention capacity of $Zn^{+2}$ increased with the increase of pH, the adsorbent dose and ionic strength. A modelization study showed that the adsorption follows Langmuir isotherm, while its kinetics was pseudo-second-order. Based on the results, it was concluded that NAB, which is natural and available, could be used as an alternative for the removal of zinc from saline aqueous solutions.

One-Class Convolutional Neural Network (OC-CNN) Model for Rapid Bridge Damage Detection Using Bridge Response Data

Fadel Yessoufou,Jinsong Zhu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.4

This study proposes a numerical investigation for rapid bridge damage detection based on a semi-supervised deep learning (DL) model and a damage index (DI)-based Gaussian process. The proposed damage detection method uses bridge response data (acceleration and displacement data) from various damage scenarios within a simply supported girder bridge subjected to a two-axle moving vehicle load. As for semi-supervised learning, we used a one-class convolutional neural network (OC-CNN) model. This model combines a one-class (OC) classification algorithm with a simple one-dimensional convolutional neural network (1D CNN) configuration. The performance of the proposed OC-CNN model was evaluated through a numerical example of a vehicle-bridge coupling system. The proposed OC-CNN model trained using acceleration data showed promising results for different vehicle weights and speeds. These results offer confidence in using the prediction error loss of the proposed OC-CNN model as an ideal damage-sensitive feature for rapid bridge damage detection. In addition, the Gaussian process used in the DI can classify the prediction error losses resulting from the change induced by different damage severities (10%, 20%, and 30%) and different types of damage scenarios (single damage, double damages, and multiple damages). These results emphasize the potential of the proposed damage detection method to monitor the state of bridges in practical engineering.

Effects of Ammonia, Urea Plus Calcium Hydroxide and Animal Urine Treatments on Chemical Composition and In sacco Degradability of Rice Straw

Fadel Elseed, A.M.A.,Sekine, J.,Hishinuma, M.,Hamana, K. Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.3

This experiment was conducted to examine the effects on the composition and rumen degradation in sacco of rice straw treated with animal urine (1 l of 2.9 g N/kg DM straw) and urea plus calcium hydroxide (2% urea plus 0.5% $Ca(OH)_2$/kg DM straw) as a cheap and relatively safe alternative for ammonia (3% ammonia solution/kg DM straw). Mold occurred in urine treated straw, but other treatments were apparently mold-free. All treatments significantly (p<0.05) increased CP content in the straw compared with untreated one. Ammonia-treated straw contained CP at about twice that in urine or urea-calcium hydroxide treated straw. NDF and hemicellulose contents decreased significantly (p<0.05) in all treatments, while ADF and cellulose showed no differences compared with untreated straw. The degradable fraction of DM, CP, NDF, hemicellulose and cellulose was significantly (p<0.05) increased for ammonia and urea-calcium hydroxide treatments than for urine treated or untreated straw except for CP of urine treated straw. Chemical treatment of rice straw increased the readily degradable fraction of CP, while it decreased the slowly degradable fraction for urine or urea-calcium hydroxide treated rice straw. The degradation rate of hemicellulose was significantly (p<0.05) increased for ammonia and urea-calcium hydroxide treatments compared to urine treated or untreated straw. However, no effect on cellulose degradation rate was found by any of the treatments. There was no improvement in the degradation kinetics caused by the urine treatment despite the improvement of the chemical composition. Although the improvement in rumen degradability was less in the urea-calcium hydroxide treatment than in the ammonia treatment, its use may be more desirable because it is less expensive to obtain, less hazardous nature, and readily available. For further improvement it is necessary to investigate the supplementation of slowly degradable nitrogen to ureacalcium hydroxide treated rice straw diet.

Clinical characteristics and outcomes of critically Ill patients with COVID-19 in Northeast Ohio: low mortality and length of stay

Fadel Francois Abi,Al-Jaghbeer Mohammed,Kumar Sany,Griffiths Lori,Wang Xiaofeng,Han Xiaozhen,Burton Robert 대한중환자의학회 2020 Acute and Critical Care Vol.35 No.4

Background: Published coronavirus disease 2019 (COVID-19) reports suggest higher mortality with increasing age and comorbidities. Our study describes the clinical characteristics and outcomes for all intensive care unit (ICU) patients admitted across the Cleveland Clinic enterprise, a 10-hospital health care system in Northeast Ohio, serving more than 2.7 million people. Methods: We analyzed the quality data registry for clinical characteristics and outcomes of all COVID-19-confirmed ICU admissions. Differences in outcomes from other health care systems and published cohorts from other parts of the world were delineated. Results: Across our health care system, 495 COVID-19 patients were admitted from March 15 to June 1, 2020. Mean patient age was 67.3 years, 206 (41.6%) were females, and 289 (58.4%) were males. Mean Acute Physiology Score was 45.3, and mean Acute Physiology and Chronic Health Evaluation III score was 60.5. In total, 215 patients (43.3%) were intubated for a mean duration of 9.2 days. Mean ICU and hospital length of stay were 7.4 and 13.9 days, respectively, while mean ICU and hospital mortality rates were 18.4% and 23.8%. Conclusions: Our health care system cohort is the fourth largest to be reported. Lower ICU and hospital mortality and length of stay were seen compared to most other published reports. Better preparedness and state-level control of the surge in COVID-19 infections are likely the reasons for these better outcomes. Future research is needed to further delineate differences in mortality and length of stay across health care systems and over time.

Robust optimum design of MTMD for control of footbridges subjected to human-induced vibrations via the CIOA

Letícia Fleck Fadel Miguel,Otávio Augusto Peter de Souza 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.86 No.5

It is recognized that the installation of energy dissipation devices, such as the tuned mass damper (TMD), decreases the dynamic response of structures, however, the best parameters of each device persist hard to determine. Unlike many works that perform only a deterministic optimization, this work proposes a complete methodology to minimize the dynamic response of footbridges by optimizing the parameters of multiple tuned mass dampers (MTMD) taking into account uncertainties present in the parameters of the structure and also of the human excitation. For application purposes, a steel footbridge, based on a real structure, is studied. Three different scenarios for the MTMD are simulated. The proposed robust optimization problem is solved via the Circle-Inspired Optimization Algorithm (CIOA), a novel and efficient metaheuristic algorithm recently developed by the authors. The objective function is to minimize the mean maximum vertical displacement of the footbridge, whereas the design variables are the stiffness and damping constants of the MTMD. The results showed the excellent capacity of the proposed methodology, reducing the mean maximum vertical displacement by more than 36% and in a computational time about 9% less than using a classical genetic algorithm. The results obtained by the proposed methodology are also compared with results obtained through traditional TMD design methods, showing again the best performance of the proposed optimization method. Finally, an analysis of the maximum vertical acceleration showed a reduction of more than 91% for the three scenarios, leading the footbridge to acceleration values below the recommended comfort limits. Hence, the proposed methodology could be employed to optimize MTMD, improving the design of footbridges.

Nutritive Evaluation of Some Fodder Tree Species during the Dry Season in Central Sudan

A. M. A. Fadel Elseed,A. E. Amin,Khadiga,A. Abdel Ati,J. Sekine,M. Hishinuma,K. Hamana 아세아·태평양축산학회 2002 Animal Bioscience Vol.15 No.6

Cardiac Arrest Management in the Workplace: Improving but Not Enough?

Descatha Alexis,Morin François,Fadel Marc,Bizouard Thomas,Mermillod-Blondin Romain,Turk Julien,Armaingaud Alexandre,Duhem Hélène,Savary Dominique 한국산업안전보건공단 산업안전보건연구원 2023 Safety and health at work Vol.14 No.1

The aim was to describe out-of-hospital cardiac arrest (OHCA) occurring in the workplace of a large emergency network, and compare the evolution of their management in the last 15 years. A retrospective study based on data from the Northern Alps Emergency Network compared characteristics of OHCA between cases in and out the workplace, and between cases occurring from January 2004 to December 2010 and from January 2011 to December 2017. Among the 15,320 OHCA cases included, 320 occurred in the workplace (2.1%). They were more often in younger men, and happened more frequently in an area with access to public defibrillation, had more often a shockable rhythm, had a cardiopulmonary resuscitation started by a bystander more frequently, and had a better outcome. Cardiopulmonary resuscitation started by a bystander was the only chain of survival link that improved for cases occurring after December 2010. Workplace OHCA seems to be managed more effectively than others; however, only a slight survival improvement was observed, suggesting that progress is still needed.

Comment on "Recurrent late seroma after immediate breast reconstruction with latissimus dorsi musculocutaneous flap"

Atiyeh, Bishara,Chahine, Fadel M. Korean Society of Plastic and Reconstructive Surge 2021 Archives of Plastic Surgery Vol.48 No.2