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Effect of digital noise reduction on the accuracy of endodontic file length determination
Mehdizadeh, Mojdeh,Khademi, Abbas Ali,Shokraneh, Ali,Farhadi, Nastaran Korean Academy of Oral and Maxillofacial Radiology 2013 Imaging Science in Dentistry Vol.43 No.3
Purpose: The aim of the present study was to evaluate the measurement accuracy of endodontic file length on periapical digital radiography after application of noise reduction digital enhancement. Materials and Methods: Thirty-five human single-rooted permanent teeth with canals measuring 20-24 mm in length were selected. ISO #08 endodontic files were placed in the root canals of the teeth. The file lengths were measured with a digital caliper as the standard value. Standard periapical digital images were obtained using the Digora digital radiographic system and a dental X-ray unit. In order to produce the enhanced images, the noise reduction option was applied. Two blinded radiologists measured the file lengths on the original and enhanced images. The measurements were compared by repeated measures ANOVA and the Bonferroni test (${\alpha}=0.05$). Results: Both the original and enhanced digital images provided significantly longer measurements compared with the standard value (P<0.05). There were no significant differences between the measurement accuracy of the original and enhanced images (P>0.05). Conclusion: Noise reduction digital enhancement did not influence the measurement accuracy of the length of the thin endodontic files on the digital periapical radiographs despite the fact that noise reduction could result in the elimination of fine details of the images.
A Novel AE Based Algorithm for PD Localization in Power Transformers
Mehdizadeh, Sina,Yazdchi, Mohammadreza,Niroomand, Mehdi The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.6
In this paper, a novel algorithm for PD localization in power transformers based on wavelet de-noising technique and energy criterion is proposed. Partial discharge is one of the main failures in power transformers. The localization of which could be very useful for maintenance systems. Acoustic signals due to a PD event are transient, irregular and non-repetitive. So wavelet transform is an efficient tool for this signal processing problem that gives a time-frequency demonstration. First, different wavelet based de-noising methods are analyzed. Then, a reasonable structure for threshold value determining and applying manner on signals is presented. Evaluated errors are good evidences for choices. Next, applying the elimination low energy frequency bands is discussed and developed as a de-noising method. Time differences between signals are used for PD localization. Different ways in time arrival detection are introduced and a novel approach in energy criterion method is presented. At the end, the quality of algorithm is verified through the different assays in lab.
Tooraj Mehdizadeh,Hossein Tajik,Sima Jafarie,Ata Kaboudari 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.5
The present study aimed at extending shelf life of rainbow trout fillet. Fish and seafoods are the most valuable nutrients, however, high levels of moisture, free amino acids, unsaturated fatty acids, and the content of nutrients make them to be categorized as spoilable and unstable foods. The objective of this research was to study of the shelf life of rainbow trout fillets using Salvia officinalis L. extract. Chemical and microbial analyses were performed on treatments. The usage of hydro-ethanol extract of S. officinalis L. significantly decreased microbial growth in fish fillet and there were significant differences among concentrations of the extract (p ≤ 0.05). The presence of extract of S. officinalis L. resulted in an inhibitory effect on the formation of TVB-N and FFA in comparison with the control group at all analytical times. In conclusion, the shelf life of fish fillets was increased noticeably using extract at 4 ± 1 °C.
Effect of digital noise reduction on the accuracy of endodontic file length determination
Mojdeh Mehdizadeh,Abbas Ali Khademi,Ali Shokraneh,Nastaran Farhadi 대한영상치의학회 2013 Imaging Science in Dentistry Vol.43 No.3
Purpose: The aim of the present study was to evaluate the measurement accuracy of endodontic file length on periapical digital radiography after application of noise reduction digital enhancement. Materials and Methods: Thirty-five human single-rooted permanent teeth with canals measuring 20-24 mm in length were selected. ISO #08 endodontic files were placed in the root canals of the teeth. The file lengths were measured with a digital caliper as the standard value. Standard periapical digital images were obtained using the Digora digital radiographic system and a dental X-ray unit. In order to produce the enhanced images, the noise reduction option was applied. Two blinded radiologists measured the file lengths on the original and enhanced images. The measurements were compared by repeated measures ANOVA and the Bonferroni test (α=0.05). Results: Both the original and enhanced digital images provided significantly longer measurements compared with the standard value (P⁄0.05). There were no significant differences between the measurement accuracy of the original and enhanced images (P¤0.05). Conclusion: Noise reduction digital enhancement did not influence the measurement accuracy of the length of the thin endodontic files on the digital periapical radiographs despite the fact that noise reduction could result in the elimination of fine details of the images.
Does transcutaneous electrical nerve stimulation reduce the laparoscopic related shoulder pain?
Abolfazl Mehdizadeh kashi,Sepideh Khodaverdi,Azam Govahi,Saeedeh Sarhadi,Mania Kaveh,Kambiz Sadegi,Roya Derakhshan,Marziyeh Ajdary,Shahla Chaichian 대한산부인과학회 2024 Obstetrics & Gynecology Science Vol.67 No.1
Objective Although laparoscopic surgery is a good substitute for laparotomy in reducing postsurgical pain, many patients complain of shoulder pain after laparoscopic surgery and require pain-relief. Post-operative pain management leads to increased patient satisfaction. Transcutaneous Electrical Nerve Stimulation (TENS) is a non-pharmacological, noninvasive modality that reduces pain by activating the descending inhibitory systems in the central nervous system. Given the importance of decreasing shoulder pain after gynecological laparoscopy, the current study aimed to investigate the management of shoulder pain in these patients using TENS. Methods This was a retrospective case-control study. A total of 112 women aged 18-45 years who experienced shoulder pain due to gynecologic laparoscopic surgery were included in the study. Patients were divided into TENS and control groups. In the TENS group, TENS was used twice for 20 minutes each, but in the control group, the patients received regular treatment. Patients were evaluated at intervals of 2, 4, 8, 24, 48, and 72 hours after laparoscopy for shoulder pain score. Results The results showed a significant decrease in visual analog scale scores at 2, 4, and 8-hour in the TENS group compared with the control group. At 24 hours evaluation, although the pain was reduced, the difference was not significant. At 48- and 72-hour assessment, all patients in each group reported zero score for severity of pain. Conclusion The findings suggest that TENS significantly reduces postoperative shoulder pain.
( Abolfazl Mehdizadeh Kashi ),( Yousef Moradi ),( Shahla Chaichian ),( Zahra Najmi ),( Kamyar Mansori ),( Forugh Salehin ),( Azade Rastgar ),( Sorour Khateri ) 대한산부인과학회 2018 Obstetrics & Gynecology Science Vol.61 No.5
Objective Endometriosis, a common hormone-dependent chronic inflammatory disease causes various symptoms including pelvic pain, which affect the physical and psychological quality of life in women of reproductive age. The present study aimed to assess the quality of life of Iranian women with endometriosis using the World Health Organization Quality of Life Instrument, Short Form (WHOQOL-BREF) questionnaire. Methods This cross-sectional study performed in Tehran between October 2014 and July 2016 included 70 Iranian women with endometriosis. The Iranian version of the WHOQOL-BREF questionnaire was used to measure quality of life in these women. The Pearson's correlation coefficient, the paired and the independent t-tests, and a linear regression model were used to statistically analyze the data using the SPSS software version 16.0. Results The total mean score of the WHOQOL-BREF questionnaire was 80.58. The highest and the lowest mean scores were observed in the environmental (28.15) and the physical health domains (10.59), respectively. A multiple linear regression model (backward method) showed that insurance coverage was associated with the total WHOQOL-BREF score, whereas age, insurance coverage, and income level were associated with domains 1 through 4, respectively (P<0.05). Conclusion Endometriosis affects various aspects of the quality of life of Iranian women who therefore require holistic management focused on both, the physical and psychological aspects of treatment.
Mohsen Mehdizadeh,Hassan Farhangi 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.11
In the present paper, microstructural evolutions and its effect on the mechanical properties of IN617 were investigated inas-received and worked conditions. Worked samples had been operated at 800 °C, under average working stress for operatingtimes of 65,000 and 98,000 h. The different phases were extracted by phase extraction methods. The OM, SEM, TEM,XRD, hardness, impact, stress rupture and tensile tests are used to investigate the microstructure and mechanical propertiesof operated alloys. The main phases in the specimens are M23C6and M6Ccarbides and Ti(C,N) compounds. In additionto these three compounds, γ' phase was also observed in both samples, despite the long operating time; although its volumefraction in the second sample (98,000 h) was less than the first sample (65,000 h). A very small amount of δ phase,topologically closed packed phase, was also detected in the samples. With increasing operating time, the area fraction ofcarbides increased from 0.5% in the as-received plate to 5.5% in the 98,000 h specimen. Unlike M23C6carbide, which hasan increasing trend with operating time, M6Ccarbide decreased from 25.7% in the 65,000 h sample to 18.7% in the 98,000 hsample. This decrease is attributed to the M6C+ M′ → M23C6+ M′′ reaction. The observed phases are in the form of plateshape, quasi-spherical and irregular and their dimensions increase with increasing operating time. The hardness and strengthvalues are higher in the 65,000 h sample than both the 98,000 h sample and the as-received plate. However these values inthe 98,000 h are higher than as-received plate.
A Novel AE Based Algorithm for PD Localization in Power Transformers
Sina Mehdizadeh,Mohammadreza Yazdchi,Mehdi Niroomand 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.6
In this paper, a novel algorithm for PD localization in power transformers based on wavelet de-noising technique and energy criterion is proposed. Partial discharge is one of the main failures in power transformers. The localization of which could be very useful for maintenance systems. Acoustic signals due to a PD event are transient, irregular and non-repetitive. So wavelet transform is an efficient tool for this signal processing problem that gives a time-frequency demonstration. First, different wavelet based de-noising methods are analyzed. Then, a reasonable structure for threshold value determining and applying manner on signals is presented. Evaluated errors are good evidences for choices. Next, applying the elimination low energy frequency bands is discussed and developed as a de-noising method. Time differences between signals are used for PD localization. Different ways in time arrival detection are introduced and a novel approach in energy criterion method is presented. At the end, the quality of algorithm is verified through the different assays in lab.