Structural damage detection based on changes of wavelet transform coefficients of correlation functions

Sadeghian, Mohsen,Esfandiari, Akbar,Fadavie Manochehr Techno-Press 2022 Structural monitoring and maintenance Vol.9 No.2

In this paper, an innovative finite element updating method is presented based on the variation wavelet transform coefficients of Auto/cross-correlations function (WTCF). The Quasi-linear sensitivity of the wavelet coefficients of the WTCF concerning the structural parameters is evaluated based on incomplete measured structural responses. The proposed algorithm is used to estimate the structural parameters of truss and plate models. By the solution of the sensitivity equation through the least-squares method, the finite element model of the structure is updated for estimation of the location and severity of structural damages simultaneously. Several damage scenarios have been considered for the studied structure. The parameter estimation results prove the high accuracy of the method considering measurement and mass modeling errors.

Do Psychological Factors Increase the Risk for Low Back Pain Among Nurses? A Comparing According to Cross-sectional and Prospective Analysis

Sadeghian, Farideh,Hosseinzadeh, Samaneh,Aliyari, Roqayeh Occupational Safety and Health Research Institute 2014 Safety and health at work Vol.5 No.1

Background: This study assesses influences of baseline psychological risk factors on prevalence of low back pain (LBP) at baseline and follow-up among nurses. Methods: A prospective longitudinal study was performed at two phases, baseline and 1-year follow-up among 246 nurses of university hospitals in Shahroud, Iran. A standardized Cultural and Psychosocial Influences on Disability questionnaire was used for data collection. Logistic regression was performed for analysis. Results: At the baseline of the study, 58.9% of nurses reported back pain in the previous 12 months. Age (p = 0.001), belief that work causes pain (p = 0.022), and somatization tendency (p = 0.002) significantly increased risk of LBP. At 1-year follow-up, prevalence of LBP was 45.7% and expectation of back pain at baseline (p = 0.016) significantly increased risk of LBP in this phase (p < 0.05). Conclusion: Results indicate that risk factors for prevalence of back pain at baseline and 1-year follow-up are different. At baseline, the risk factors are age, belief that work causes pain, and somatization tendency, and at follow-up, expectation of pain is the major risk factor.

Do Psychological Factors Increase the Risk for Low Back Pain Among Nurses? A Comparing According to Cross-sectional and Prospect

Farideh Sadeghian,Samaneh Hosseinzadeh,Roqayeh Aliyari 한국산업안전보건공단 산업안전보건연구원 2014 Safety and health at work Vol.5 No.1

BackgroundThis study assesses influences of baseline psychological risk factors on prevalence of low back pain (LBP) at baseline and follow-up among nurses. MethodsA prospective longitudinal study was performed at two phases, baseline and 1-year follow-up among 246 nurses of university hospitals in Shahroud, Iran. A standardized Cultural and Psychosocial Influences on Disability questionnaire was used for data collection. Logistic regression was performed for analysis. ResultsAt the baseline of the study, 58.9% of nurses reported back pain in the previous 12 months. Age (p = 0.001), belief that work causes pain (p = 0.022), and somatization tendency (p = 0.002) significantly increased risk of LBP. At 1-year follow-up, prevalence of LBP was 45.7% and expectation of back pain at baseline (p = 0.016) significantly increased risk of LBP in this phase (p < 0.05). ConclusionResults indicate that risk factors for prevalence of back pain at baseline and 1-year follow-up are different. At baseline, the risk factors are age, belief that work causes pain, and somatization tendency, and at follow-up, expectation of pain is the major risk factor.

A graphical user interface for stand-alone and mixed-type modelling of reinforced concrete structures

Vahid Sadeghian,Frank Vecchio 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.16 No.2

FormWorks-Plus is a generalized public domain user-friendly preprocessor developed to facilitate the process of creating finite element models for structural analysis programs. The lack of a graphical user interface in most academic analysis programs forces users to input the structural model information into the standard text files, which is a time-consuming and error-prone process. FormWorks-Plus enables engineers to conveniently set up the finite element model in a graphical environment, eliminating the problems associated with conventional input text files and improving the user’s perception of the application. In this paper, a brief overview of the FormWorks-Plus structure is presented, followed by a detailed explanation of the main features of the program. In addition, demonstration is made of the application of FormWorks-Plus in combination with VecTor programs, advanced nonlinear analysis tools for reinforced concrete structures. Finally, aspects relating to the modelling and analysis of three case studies are discussed: a reinforced concrete beam-column joint, a steel-concrete composite shear wall, and a SFRC shear panel. The unique mixed-type frame-membrane modelling procedure implemented in FormWorks-Plus can address the limitations associated with most frame type analyses.

Natural and organo-montmorillonite as antibacterial nanoclays for cotton garment

Ali Sadeghian Maryan,Majid Montazer 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.22 No.-

Here, antibacterial activities of the powder and colloidal forms of natural and organo-montmorillonite(Mt) and also clay mineral and the cotton fabrics treated with various Mt and clay mineral wereinvestigated against S. aurous as Gram-positive and E. coli as Gram-negative bacteria based on AATCC 100standardmethod. The durability of the treated cotton fabrics was also studied against home laundering. The cell cytotoxicity of natural and modified montmorillonite was assessed through MTT against cellfibroblast of human skin. The natural and organo-Mt in powder and colloid forms and also on the cottonfabrics indicated good antibacterial activities however clay mineral showed no antibacterial properties. Further, the kinetic of bacteria killing of treated cotton fabrics followed Chick–Watson model. Naturalmontmorillonite indicated lower cytotoxicity in comparison of cell viability of natural and modifiedmontmorillonite with human skin cell.

Controller tuning based on optimization algorithms of a novel spherical rolling robot

Rasoul Sadeghian,Islamic Azad University 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

This study presents the construction process of a novel spherical rolling robot and control strategies that are used to improve robot locomotion. The proposed robot drive mechanism is constructed based on a combination of the pendulum and wheel drive mechanisms. The control model of the proposed robot is developed, and the state space model is calculated based on the obtained control model. Two control strategies are defined to improve the synchronization performance of the proposed robot motors. The proportional-derivative and proportional-integral-derivative controllers are designed based on the pole placement method. The proportional-integral-derivative controller leads to a better step response than the proportional-derivative controller. The controller parameters are tuned with genetic and differential evaluation algorithms. The proportional-integral-derivative controller which is tuned based on the differential evaluation algorithm leads to a better step response than the proportional-integral-derivative controller that is tuned based on genetic algorithm. Fuzzy logics are used to reduce the robot drive mechanism motors synchronizing process time to the end of achieving a high-performance controller. The experimental implementation results of fuzzy-proportional-integral-derivative on the proposed spherical rolling robot resulted in a desirable synchronizing performance in a short time.

Successful Treatment of Lupoid Cutaneous Leishmaniasis with Glucantime and Topical Trichloroacetic Acid (A Case Report)

Mohamad Ali Nilforoushzadeh,Giti Sadeghian,Fariba Jaffary,Hengameh Ziaei,Liela Shirani-Bidabad,Parvin Mahzoni 대한기생충학열대의학회 2008 The Korean Journal of Parasitology Vol.46 No.3

Mesenchymal Stem Cells Improved the Ultrastructural Morphology of Cerebral Tissues after Subarachnoid Hemorrhage in Rats

Mohammad Ali Khalili,Fatemeh Sadeghian-Nodoushan,Farzaneh Fesahat,Seyed Mohsen Mir-Esmaeili,Morteza Anvari,Seyed Hossain Hekmati-moghadam 한국뇌신경과학회 2014 Experimental Neurobiology Vol.23 No.1

Subarachnoid hemorrhage (SAH) causes widespread disruption in the cerebral architecture.The process of SAH is complicated and many people lose their lives or become disabled after injury. Mesenchymal stem cells (MSCs) are considered as good candidate for repair of cerebral damage. The aim was to assess the ultrastructural changes in the rat cerebral tissue after intravenous transplantation of MSCs. Female Wistar rats (8 per group) weighing 275~300 g were assigned to control (SAH+PBS) and experimental groups (SAH+MSCs).The samples from middle cerebral arterial wall and parietal cerebral tissue were prepared for transmission electron microscopy (TEM) according to standard protocol. Fine architectures of the vessel wall, including the contraction of the inner layer, smooth muscle layer,as well as neural cells were observed after SAH. Cerebral arterial wall and cortex, including neuronal and glial cells were injured post SAH. But, administration of MSCs improved the structural integrity of cerebral tissues. Changes were much more balanced with their relative improvement in some areas. The role of MSCs for repairing the injured cerebral tissues post experimental SAH was approved by electron microscopy.

C2 Body Fracture: Report of Cases Managed Conservatively by Philadelphia Collar

Rouzbeh Motiei-Langroudi,Homa Sadeghian 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.5

Study Design: Case series. Purpose: To present results of conservative management in patients with pure C2 body fractures. Overview of Literature: Axis body fractures, a less common subgroup of C2 fractures, are commonly classified as vertical coronal, vertical sagittal, and transverse subtypes. While the treatment paradigm for other C2 fractures is clear, there is insufficient evidence to support treatment guidelines for C2 body fractures. Methods: Eleven patients with pure C2 body fractures were managed with external immobilization and followed thereafter. Results: All neurologic examinations were normal. In computed tomography (CT) scans, four, two, three, and two patients had a coronal, sagittal, horizontal, and burst fracture, respectively. Magnetic resonance imaging showed hematoma and partial rupture in the anterior longitudinal ligament in four patients, posterior ligamentous complex injury in one, and normal ligamentous structure in six. All fractures were managed conservatively using the Philadelphia collar, which was continued until complete disappearance of symptoms (within 1–3 months in all patients). The decision to discontinue the neck collar was made by a dynamic neck X-ray and CT scan that showed complete bony fusion. All patients were then followed for an additional 1.5 years (mean follow-up of 21 months for all patients). No patient showed any neurologic symptoms or deficits during the follow-up period. Conclusions: In patients with pure C2 body fracture, non-operative management with Philadelphia neck collar is a safe and efficacious option, even in the presence of some sort of ligamentous injury.

Predicting the Need for Surgery in Patients with Lumbar Disc Herniation: A New Internally Validated Scoring System

Motiei-Langroudi Rouzbeh,Sadeghian Homa,Ekanem Uduak-Obong,Safdar Aleeza,Grossbach Andrew James,Viljoen Stephanus 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.6

Study Design: Prospective study.Purpose: To propose a scoring system for predicting the need for surgery in patients with lumbar disc herniation (LDH).Overview of Literature: The indications for surgery in patients with LDH are well established. However, the exact timing of surgery is not. According to surgeons, patients with failed conservative treatment who underwent delayed surgery, often after 6 months postsymptom initiation, have poor functional recovery and outcome.Methods: The current study included patients with symptomatic LDH. Patients with an indication for emergent surgery such as profound or progressive motor deficit, cauda equina syndrome, and diagnoses other than single-level LDH were excluded from the analysis. All patients followed a conservative treatment regimen (a combination of physical therapy, pain medications, and/or spinal epidural steroid injections). Surgery was indicated for patients who continuously experienced pain despite maximal conservative therapy.Results: In total, 134 patients met the inclusion and exclusion criteria. Among them, 108 (80.6%) responded to conservative management, and 26 (19.4%) underwent unilateral laminotomy and microdiscectomy. The symptom duration, disc degeneration grade on magnetic resonance imaging (Pfirrmann disc grade), herniated disc location and type, fragment size, and thecal sac diameter significantly differed between patients who responded to conservative treatment and those requiring surgery. The area under the receiver operating characteristic curve of the scoring system based on the anteroposterior size of the herniated disc fragment and herniated disc location and type was 0.81.Conclusions: A scoring system based on herniated disc/fragment size, location, and type can be applied to predict the need for surgery in patients with LDH. In the future, this tool can be used to prevent unnecessarily prolonged conservative management (>4–8 weeks).