A new damage index to monitor the range of the penetration process in thick laminates

2008 ◽  
Vol 68 (13) ◽  
pp. 2646-2652 ◽  
Author(s):  
Giovanni Belingardi ◽  
Maria Pia Cavatorta ◽  
Davide Salvatore Paolino
Keyword(s):  
Damage Index ◽  
Penetration Process ◽  
Thick Laminates

Assessment of Quality of Life (QoL) in Systemic Lupus Erythematosus Patients at a Tertiary Care Hospital in Egypt

2019 ◽  
Vol 15 (4) ◽  
pp. 304-311
Author(s):  
Mervat E. Behiry ◽  
Sahar A. Ahmed ◽  
Eman H. Elsebaie
Keyword(s):  
Quality Of Life ◽  
Systemic Lupus Erythematosus ◽  
Disease Activity ◽  
Lupus Erythematosus ◽  
Tertiary Care ◽  
Damage Index ◽  
Life Questionnaire ◽  
Care Hospital ◽  
Systemic Lupus

: Systemic Lupus Erythematosus (SLE) has a profound impact on quality of life. Objective: The objective of this study was to explore the quality of life among Egyptian SLE patients and to assess its relationships with demographic and clinical features. Methods: One hundred sixty-four SLE patients were recruited for this study. Demographic information; clinical parameters; disease activity, as evaluated by the systemic lupus erythematosus Disease Activity Index; and organ damage, as assessed by the systemic lupus international Collaborative Clinics/American College of Rheumatology Damage Index, were reported. Quality of life was assessed with a quality of life questionnaire specifically designed for patients with systemic lupus erythematosus; the questions are grouped in the following six domains: physical function, sociooccupational activities, symptoms, treatment, mood, and self-image. Higher values indicate poorer quality of life. Conclusion: Poor quality of life among Egyptian SLE patients and disease activity are strongly related to impaired lifestyles in these patients.

Threaded inserts pull-through behaviour in carbon-epoxy thick laminates

2017 ◽  
Vol 173 ◽  
pp. 86-95 ◽  
Author(s):  
Edoardo Maria Carrai ◽  
Alessia Prato ◽  
Marco Anghileri
Keyword(s):  
Pull Through ◽  
Thick Laminates

scholarly journals Predictors of renal damage in systemic lupus erythematous patients: data from a multiethnic, multinational Latin American lupus cohort (GLADEL)

RMD Open ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. e001299
Author(s):  
Cristina Reátegui-Sokolova ◽  
Manuel F Ugarte-Gil ◽  
Guillermina B Harvey ◽  
Daniel Wojdyla ◽  
Guillermo J Pons-Estel ◽  
...  
Keyword(s):  
Risk Factors ◽  
Systemic Lupus Erythematosus ◽  
Latin American ◽  
Lupus Erythematosus ◽  
Renal Damage ◽  
Cox Regression ◽  
Damage Index ◽  
Early Response ◽  
Male Gender ◽  
Systemic Lupus

AimA decrease in proteinuria has been considered protective from renal damage in lupus nephritis (LN), but a cut-off point has yet to be established. The aim of this study was to identify the predictors of renal damage in patients with LN and to determine the best cut-off point for a decrease in proteinuria.MethodsWe included patients with LN defined clinically or histologically. Possible predictors of renal damage at the time of LN diagnosis were examined: proteinuria, low complement, anti-double-stranded DNA antibodies, red cell casts, creatinine level, hypertension, renal activity (assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)), prednisone dose, immunosuppressive drugs and antimalarial use. Sociodemographic variables were included at baseline. Proteinuria was assessed at baseline and at 12 months, to determine if early response (proteinuria <0.8 g/day within 12 months since LN diagnosis) is protective of renal damage occurrence. Renal damage was defined as an increase of one or more points in the renal domain of The Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index (SDI). Cox regression models using a backward selection method were performed.ResultsFive hundred and two patients with systemic lupus erythematosus patients were included; 120 patients (23.9%) accrued renal damage during their follow-up. Early response to treatment (HR=0.58), antimalarial use (HR=0.54) and a high SES (HR=0.25) were protective of renal damage occurrence, whereas male gender (HR=1.83), hypertension (HR=1.86) and the renal component of the SLEDAI (HR=2.02) were risk factors for its occurrence.ConclusionsEarly response, antimalarial use and high SES were protective of renal damage, while male gender, hypertension and higher renal activity were risk factors for its occurrence in patients with LN.

scholarly journals Mode Shape-Based Damage Detection Method (MSDI): Experimental Validation

2021 ◽  
Vol 11 (10) ◽  
pp. 4589
Author(s):  
Ivan Duvnjak ◽  
Domagoj Damjanović ◽  
Marko Bartolac ◽  
Ana Skender
Keyword(s):  
Boundary Conditions ◽  
Damage Detection ◽  
Mode Shape ◽  
Experimental Validation ◽  
Detection Method ◽  
Dynamic Properties ◽  
Damage Index ◽  
Main Principle ◽  
The Difference ◽  
Different Levels

The main principle of vibration-based damage detection in structures is to interpret the changes in dynamic properties of the structure as indicators of damage. In this study, the mode shape damage index (MSDI) method was used to identify discrete damages in plate-like structures. This damage index is based on the difference between modified modal displacements in the undamaged and damaged state of the structure. In order to assess the advantages and limitations of the proposed algorithm, we performed experimental modal analysis on a reinforced concrete (RC) plate under 10 different damage cases. The MSDI values were calculated through considering single and/or multiple damage locations, different levels of damage, and boundary conditions. The experimental results confirmed that the MSDI method can be used to detect the existence of damage, identify single and/or multiple damage locations, and estimate damage severity in the case of single discrete damage.

scholarly journals Evaluation of Damage Process of a Coating by Using Nonlinear Ultrasonic Method

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 440
Author(s):  
Chunguang Xu ◽  
Lei He ◽  
Shiyuan Zhou ◽  
Dingguo Xiao ◽  
Pengzhi Ma
Keyword(s):  
Tensile Stress ◽  
Order Parameter ◽  
Evaluation Method ◽  
Early Stage ◽  
Ultrasonic Method ◽  
Nonlinear Coefficient ◽  
Damage Index ◽  
Second Order ◽  
External Loading ◽  
Nonlinear Ultrasonic

During the service or external loading of the surface coating, the damage accumulation may develop in the coating or at the interface between the substrate and the coating, but it is difficult to measure directly in the early stage, so the acoustic nonlinear parameters are used as the early damage index of the coating. In this paper, the nonlinear wave motion equation is solved by the perturbation method and the new relationship between the relative ratio of second-order parameter and third-order parameter was derived. The nonlinear ultrasonic testing system is used to detect received signals during tensile testing of for the specimen with Al2O3 coatings. It is found that when the stress is less than 260 MPa, the appearance of the coating has no obvious change, but the nonlinear coefficients measured by the experiment increase with the increase of the tensile stress. By comparing the curves of nonlinear coefficients and stress respectively, the fluctuation of curves the second-order nonlinear coefficient A2 and the relative nonlinear coefficient β′ to stress is relatively small, and close to the linear relationship with the tensile stress, which indicates that the two parameters of the specimen with Al2O3 coatings are more sensitive to the bonding conditions, and can be used as an evaluation method to track the coating damage.

scholarly journals Detection and localization of multiple small damages in beam

2021 ◽  
Vol 13 (1) ◽  
pp. 168781402098732
Author(s):  
Ayisha Nayyar ◽  
Ummul Baneen ◽  
Syed Abbas Zilqurnain Naqvi ◽  
Muhammad Ahsan
Keyword(s):  
Frequency Response ◽  
Natural Frequencies ◽  
Signal To Noise Ratio ◽  
Moving Average ◽  
A Priori ◽  
Damage Index ◽  
High Signal ◽  
Frequency Range ◽  
Spatial Locality ◽  
System Frequency

Localizing small damages often requires sensors be mounted in the proximity of damage to obtain high Signal-to-Noise Ratio in system frequency response to input excitation. The proximity requirement limits the applicability of existing schemes for low-severity damage detection as an estimate of damage location may not be known  a priori. In this work it is shown that spatial locality is not a fundamental impediment; multiple small damages can still be detected with high accuracy provided that the frequency range beyond the first five natural frequencies is utilized in the Frequency response functions (FRF) curvature method. The proposed method presented in this paper applies sensitivity analysis to systematically unearth frequency ranges capable of elevating damage index peak at correct damage locations. It is a baseline-free method that employs a smoothing polynomial to emulate reference curvatures for the undamaged structure. Numerical simulation of steel-beam shows that small multiple damages of severity as low as 5% can be reliably detected by including frequency range covering 5–10th natural frequencies. The efficacy of the scheme is also experimentally validated for the same beam. It is also found that a simple noise filtration scheme such as a Gaussian moving average filter can adequately remove false peaks from the damage index profile.

scholarly journals Early Detection of Defects through the Identification of Distortion Characteristics in Ultrasonic Responses

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 850
Author(s):  
Pietro Burrascano ◽  
Matteo Ciuffetti
Keyword(s):  
Early Detection ◽  
Additive Noise ◽  
Linear Models ◽  
High Stress ◽  
Damage Index ◽  
Hammerstein Model ◽  
Linear Behavior ◽  
Non Linear ◽  
Ultrasonic Techniques ◽  
Detection Of Defects

Ultrasonic techniques are widely used for the detection of defects in solid structures. They are mainly based on estimating the impulse response of the system and most often refer to linear models. High-stress conditions of the structures may reveal non-linear aspects of their behavior caused by even small defects due to ageing or previous severe loading: consequently, models suitable to identify the existence of a non-linear input-output characteristic of the system allow to improve the sensitivity of the detection procedure, making it possible to observe the onset of fatigue-induced cracks and/or defects by highlighting the early stages of their formation. This paper starts from an analysis of the characteristics of a damage index that has proved effective for the early detection of defects based on their non-linear behavior: it is based on the Hammerstein model of the non-linear physical system. The availability of this mathematical model makes it possible to derive from it a number of different global parameters, all of which are suitable for highlighting the onset of defects in the structure under examination, but whose characteristics can be very different from each other. In this work, an original damage index based on the same Hammerstein model is proposed. We report the results of several experiments showing that our proposed damage index has a much higher sensitivity even for small defects. Moreover, extensive tests conducted in the presence of different levels of additive noise show that the new proposed estimator adds to this sensitivity feature a better estimation stability in the presence of additive noise.

scholarly journals EQ-5D-3L full health state discriminates between drug and placebo in clinical trials of systemic lupus erythematosus

Rheumatology ◽  
2021 ◽  
Author(s):  
Julius Lindblom ◽  
Alvaro Gomez ◽  
Alexander Borg ◽  
Sharzad Emamikia ◽  
Dimitris Ladakis ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Lupus Erythematosus ◽  
Damage Index ◽  
Patient Reported Outcome ◽  
Health State ◽  
Full Health ◽  
Chi Square ◽  
Discriminative Ability ◽  
Exact Test ◽  
Patient Reported

Abstract Objectives To investigate the discriminative ability of EQ-5D-3L full health state (FHS) in clinical trials of SLE, and identify factors associated with FHS after treatment. Methods Data from the BLISS-52 (NCT00424476) and BLISS-76 (NCT00410384) trials of belimumab (N = 1684) were utilised. FHS was defined as a response of no problems in all five EQ-5D-3L dimensions, yielding an index score of 1. The Pearson’s chi-square or Fisher’s exact test was employed for comparisons, and logistic regression for adjustments and assessment of independence. Results We demonstrated higher EQ-5D-3L FHS frequencies among patients given standard therapy (ST) plus the licensed belimumab dose versus ST alone (26.1% versus 19.4%; P = 0.001; week 52), and within SRI-4 responders versus non-responders (27.0% versus 19.8%; P &lt; 0.001; week 52) from week 36 to 52. In multivariable regression analysis, SLEDAI-2K (OR: 0.90; 95% CI: 0.87 − 0.94; P &lt; 0.001) and SLICC/ACR Damage Index (OR: 0.79; 95% CI: 0.69 − 0.91; P = 0.001) scores were independently associated with lower FHS frequencies at week 52, while adding monthly infusions of belimumab 10 mg/kg to ST favoured FHS perception (OR: 1.60; 95% CI: 1.15 − 2.24; P = 0.006). Add-on belimumab 10 mg/kg yielded higher FHS frequencies in antimalarial users versus non-users (29.9% versus 20.1%; P = 0.011), and in anti-dsDNA and anti-Sm positive versus negative patients (31.4% versus 13.4%; P &lt; 0.001 and 33.0% versus 22.6%; P = 0.010, respectively), whereas no significant differences were observed in patients given ST alone. Conclusion EQ-5D-3L FHS distinguished belimumab from placebo and responders from non-responders, and exhibited known-group validity in subgroup analysis. FHS may prove a useful patient-reported outcome in SLE studies.

Sign in / Sign up

Export Citation Format

Share Document