Damage detection in concrete gravity dams using signal processing algorithms based on earthquake vibrations

In structural engineering, damage detection in concrete gravity dams (CGDS) is a practical problem. Dam destruction can have severe financial consequences and may even lead to fatalities. Therefore, structural health monitoring in advance is crucial. In this regard, a well-known CGD, namely the Pine Flat Dam, has been chosen for the Finite Element Modeling. In this paper, damage is induced in the dam neck through elasticity modulus reduction by 40 % and 80 %. In addition, after applying Northridge earthquake, the acceleration in structure nodes for intact and damaged cases are recorded in vector formats. Using various methods, such as Discrete-time Fourier Transform (DTFT), Wavelet transform and Wiener transform, the differences between these two signals are investigated. The standard deviation (S.D.) of variations is chosen as the performance metric and is applied to the signal amplitude between intact and damage observations/signals. The reason why several signal processing algorithms are used is finding an approach which shows more clearly the differences caused by the destruction. This is evaluated via S.D. values for different algorithms. The results confirm the superiority of DTFT over other given algorithms. DTFT has a negligible outperformance (approximately zero dB) with respect to the Wavelet transform in both the crest and the lower nodes of the dam. This rate for DTFT and Wavelet is 10dB higher than that of Wiener and 35 dB in comparison with the simple amplitude difference. Moreover, the detection thresholds for the given methods are compared, and it is verified that the DTFT and Wavelet indicate the best performance

Short-Term Results of Sutureless Scleral Tunnel Trabeculectomy Using Adjunctive Topical Bevacizumab

This study was performed to assess the short-term effect of sutureless scleral tunnel trabeculectomy procedure with and without topical bevacizumab. Thirty patients with Primary Open-Angle Glaucoma (POAG) were enrolled and randomly divided to two groups. Patients in the first group (15 patients) underwent sutureless trabeculectomy without topical bevacizumab and patients in the second group (15 patients) underwent sutureless trabeculectomy with 1.25 mg of topical bevacizumab. Intraocular Pressure (IOP) of both groups was measured by an expert ophthalmologist, without awareness of the patient’s study group before the operation and six months post-operatively. Out of 30 patients in this study, six females (40%) and nine males (60%) underwent the sutureless trabeculectomy procedure (group A) as well as seven females (46.7%) and eight males (53.3%) underwent sutureless trabeculectomy with topical bevacizumab (group B). The mean age of the patients was not significantly different between the two groups (P = 0.91). A statistically significant difference in time variation of IOP was found between the two groups (P < 0.001). Mean IOP was 18.4 ± 4.35 mmHg in the sutureless group without bevacizumab and 11.73 ± 2.12 mmHg in the sutureless group with bevacizumab, six months post-surgically. No statistical significant differences were found in the baseline IOP between the two groups (P = 0.28). However, IOP changed significantly in group A and B from baseline to six months post-operatively (P = 0.004 and P < 0.001 respectively). According to the current findings, the sutureless trabeculectomy procedure is an effective surgical method for reduction of IOP. Addition of a single dose of 1.25 mg topical bevacizumab was more effective in reduction of IOP compared to sutureless trabeculectomy alone.Â

Short-Term Results of Sutureless Scleral Tunnel Trabeculectomy Using Adjunctive Topical Bevacizumab

This study was performed to assess the short-term effect of sutureless scleral tunnel trabeculectomy procedure with and without topical bevacizumab. Thirty patients with Primary Open-Angle Glaucoma (POAG) were enrolled and randomly divided to two groups. Patients in the first group (15 patients) underwent sutureless trabeculectomy without topical bevacizumab and patients in the second group (15 patients) underwent sutureless trabeculectomy with 1.25 mg of topical bevacizumab. Intraocular Pressure (IOP) of both groups was measured by an expert ophthalmologist, without awareness of the patient’s study group before the operation and six months post-operatively. Out of 30 patients in this study, six females (40%) and nine males (60%) underwent the sutureless trabeculectomy procedure (group A) as well as seven females (46.7%) and eight males (53.3%) underwent sutureless trabeculectomy with topical bevacizumab (group B). The mean age of the patients was not significantly different between the two groups (P = 0.91). A statistically significant difference in time variation of IOP was found between the two groups (P < 0.001). Mean IOP was 18.4 ± 4.35 mmHg in the sutureless group without bevacizumab and 11.73 ± 2.12 mmHg in the sutureless group with bevacizumab, six months post-surgically. No statistical significant differences were found in the baseline IOP between the two groups (P = 0.28). However, IOP changed significantly in group A and B from baseline to six months post-operatively (P = 0.004 and P < 0.001 respectively). According to the current findings, the sutureless trabeculectomy procedure is an effective surgical method for reduction of IOP. Addition of a single dose of 1.25 mg topical bevacizumab was more effective in reduction of IOP compared to sutureless trabeculectomy alone.

The Effect of Intravitreal Bevacizumab on Central Serous Chorioretinopathy

The aim of this study was to investigate the efficacy of Intravitreal Injection of Bevacizumab (IVB) in patients with Central Serous Chorioretinopathy (CSC) compared to the control group, after four months of injection. In this study, 30 eyes of 30 patients with CSC, who were in the age range of 23 to 50 years old (70% male subject) were included. Eligible patients were randomly allocated to the intervention (n = 15) and control groups (n = 15). Patients in the intervention group received a single dose injection of bevacizumab (1.25 mg in 0.05 mL), while patients in the control group were followed-up during the same time interval, without any medical interventions. Corrected Distance Visual Acuity (CDVA) and Central Macular Thickness (CMT) were evaluated as the primary outcome measures at the four-month follow-up. There was no statistically significant difference between the intervention and control groups regarding their baseline characteristics. Corrected Distance Visual Acuity was improved significantly in the intervention group (P < 0.001), while this improvement was not observed in the control group. Furthermore, greater improvement of CDVA was detected in the IVB group compared to the patients without injection (P = 0.018). The CMT findings were in line with CDVA changes in both groups, revealing a significant reduction of CMT only in the intervention group (P < 0.001). Also, thinner central retina was found in the intervention group compared to the comparison group, at the four-month follow-up (P < 0.001). Based on the findings, bevacizumab could be effective for improvement of both anatomical and functional outcomes in patients with CSC

Increasing Reliability of a Power System in Presence of Static Transfer Switch

Abstract: Long interruptions cause no compensable problems to the power systems and decrease the reliability of the system significantly. One of new technologies that decrease the fault time is Static Transfer Switch (STS) with alternative power supply. In this study an industrial plant with motor loads has been studied with and without use of STS in front of a voltage fault. The simulations have been done to demonstrate the speed of the motors during the faults. As the interruption duration is an important factor in reliability analyzing, some faults with various durations have been applied to the system to study the reliability of the system with and without STS. The results are given to verify the STS efficiency in increasing the system reliability by restoring the motors' speed drop in least time

SURVEY OF MATLAB EFFICIENCY IN DAMAGE DETECTION OF CONCRETE GRAVITY IN CONCRETE GRAVITY DAMS

Detection of damage in concrete gravity dams (CGDs) is one of the challenges that need to be overcome since dam failure may lead to irreversible consequences. This research aims to detect structural damage within CGDs by wavelet analysis. From a structural point of view, stiffness is an important factor in the dynamic behaviour of concrete gravity dam systems. Any sudden change in the stiffness leads to alteration in the dynamic response of the structures. The proposed analysis of such a condition will help to investigate the responses before and after the occurrence of any structural damage. The main contributions of this paper are to detect the existence of any damage in the dam structure and determine the damage location along the height of the dam. In order to achieve these purposes, three finite element models of the Pine Flat, Bluestone, and Folsom dams are chosen as case studies. These dams have been modelled for both intact and damaged states, and their geometrical, physical, and mechanical characteristics are defined by SAP2000 software. A series of modal analyses was performed to determine the frequencies and shapes of the structural motions. After reduction of the elasticity modulus by 20% and 50%, the Discrete Wavelet Transform (DWT) was applied to the difference between the intact and damaged observations. Then, the DWT outputs were analysed to get information about the existence of damage as well as its location in the dam structure. Overall, from the obtained results, the main finding of this study states that the location and severity of the structural damages have been efficiently detected according to the significant amplitude variations in DWT diagrams. ABSTRAK: Pengesanan kerosakan pada empangan graviti konkrit (CGDs) adalah salah satu cabaran yang perlu diatasi disebabkan kegagalan empangan yang boleh membawa kepada akibat buruk. Kajian ini bertujuan bagi mengesan kerosakan struktur dalam CGDs menggunakan analisis wavelet. Dari sudut pandang struktur, struktur yang kukuh adalah faktor penting dalam sifat dinamik sistem empangan graviti konkrit. Sebarang perubahan secara tiba-tiba pada struktur bangunan membawa kepada perubahan tindak balas dinamik struktur. Analisis yang dicadangkan terhadap keadaan ini membantu dalam memberi tindak balas sebelum dan selepas jika berlaku sebarang kerosakan struktur. Sumbangan utama kajian ini adalah bagi mengesan jika terdapat sebarang kerosakan pada struktur dalam empangan dan menentukan lokasi kerosakan sepanjang ketinggian empangan. Bagi mencapai matlamat ini, tiga model unsur terhingga daripada empangan Pine Flat, Bluestone dan Folsom telah dipilih sebagai kes kajian. Kesemua empangan ini dimodelkan bagi kedua-dua keadaan iaitu ketika baik dan rosak. Ciri geometri, fizikal dan ciri-ciri mekanikal juga telah ditakrif menggunakan perisian SAP2000. Satu siri model analisis telah dijalankan bagi menentukan frekuensi dan bentuk gerakan struktur. Selepas pengurangan modulus keanjalan sebanyak 20% dan 50%, Transformasi Wavelet Diskret (DWT) telah digunakan bagi mengesan perbezaan antara keadaan baik dan rosak. Kemudian, hasil dari DWT ini dianalisis bagi mendapatkan maklumat mengenai kewujudan kerosakan pada empangan dan juga lokasi kerosakan dalam struktur empangan. Secara keseluruhan, hasil kajian berjaya menentukan lokasi dan tahap kerosakan struktur dengan cekap mengikut variasi amplitud ketara dalam rajah DWT

Effectiveness of oral clonidine and gabapentin on peripheral neuropathy in diabetic patients in southwestern Iran: a randomized clinical trial

Abstract Background Peripheral neuropathy is not only the most prevalent consequence of diabetes but also the main reason for foot ulceration, disability, and amputation. Therefore, the current study aims to determine the effectiveness of oral clonidine and gabapentin on peripheral neuropathy in diabetic patients. Methods This 12-week, randomized, and parallel-group trial was conducted to compare the efficacy of oral clonidine and gabapentin with gabapentin alone in diabetic patients in southwest Iran during the first half of 2021. Thirty patients with type 2 diabetes with peripheral neuropathy as assessed by a visual analog scale (VAS) and divided into two groups of 15 patients, treated for up to three months. The data were analyzed using SPSS-21 software. In order to report the results, descriptive indices, independent t-test, one-way analysis of covariance (ANCOVA) and analysis of variance with repeated measures were used. Results The mean and standard deviation of the age of the participants in the clonidine + gabapentin group was equal to 50.20 ± 7.44, and in the gabapentin group was equal to 50.47 ± 7.57 (t = 0.10, P-value = 0.923). This research showed a significant difference between the clonidine + gabapentin group and with gabapentin group in terms of neuropathic pain and the severity of neuropathic pain (P < 0.001). Conclusions According to this research results, clonidine + gabapentin can reduce neuropathic pain and the severity of neuropathic pain in diabetic patients. Therefore, it is recommended that healthcare professionals with diabetes expertise prescribe these medications to reduce neuropathic pain and its severity. Trial registration This study was registered in the Iranian Clinical Trials System with the ID (IRCT20211106052983N1) on 14/01/2022

Is Meconium Obstruction Distinguishable from Intestinal Obstruction through Ultrasound?

Background: Since the treatment of meconium ileus is very different from other types of intestinal obstruction, it is very important to distinguish these two entities. The aim of this study was to assess sonographic findings to differentiate meconium ileus from other types of obstruction. Methods: This study was performed in Dr. Sheikh and Akbar hospitals, Mashhad Medical University of Science, Iran, during 2017- 2018. The imaging signs of 25 newborns (aged 2-8 days) with delayed passage of meconium were documented. These neonates were suspicious of low type intestinal obstruction. In cases with the simple form of meconium ileus and the small left colon syndrome, ultrasonic guided Gastrografin enema was performed for the treatment. In the patients with the failure of medical treatment and in other surgical cases, the appropriate surgical procedure was performed. Results: The subjects in this study were diagnosed with small bowel atresia (n=9), a simple form of meconium ileus (n=6), a complicated form of meconium ileus (n=3), small left colon syndrome (n=3), bowel atresia and duplication (n=1), and Hirschsprung’s disease (n=3). The ultrasound findings were as follows: a totally or partially micro-colon in almost all patients, collapsed small bowel in right lower quadrant in all of the patients with bowel atresia, hypoechoic meconium in rectosigmoid in small left colon syndrome and Hirschsprung’s disease, hypoechoic tubular or beaded intraluminal inspissated meconium within terminal ileum, and the floating air bubbles (sonographic soap bubble sign) within fluids on proximal dilated loops in meconium ileus cases. Conclusion: Although plain abdominal radiography confirmed bowel obstructions in all patients with delayed passage of meconium, it had a low level of specificity in the diagnosis and cause of obstruction.  Abdominal ultrasound had a high level of accuracy in the correct diagnosis of meconium obstructions and its differentiation from other intestinal obstructions. Accordingly, it eliminates the need to do a diagnostic contrast enema in order to differentiate these entities