Artigos de revistas: "NDE test"

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Kondziella, Daniel, Markus Harboe Olsen, Coline L. Lemale e Jens P. Dreier. "Migraine aura, a predictor of near-death experiences in a crowdsourced study". PeerJ 7 (4 de dezembro de 2019): e8202. http://dx.doi.org/10.7717/peerj.8202.

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Background Near-death experiences (NDE) occur with imminent death and in situations of stress and danger but are poorly understood. Evidence suggests that NDE are associated with rapid eye movement (REM) sleep intrusion, a feature of narcolepsy. Previous studies further found REM abnormalities and an increased frequency of dream-enacting behavior in migraine patients, as well as an association between migraine with aura and narcolepsy. We therefore investigated if NDE are more common in people with migraine aura. Methods We recruited 1,037 laypeople from 35 countries and five continents, without any filters except for English language and age ≥18 years, via a crowdsourcing platform. Reports were validated using the Greyson NDE Scale. Results Eighty-one of 1,037 participants had NDE (7.8%; CI [6.3–9.7%]). There were no significant associations between NDE and age (p > 0.6, t-test independent samples) or gender (p > 0.9, Chi-square test). The only significant association was between NDE and migraine aura: 48 (6.1%) of 783 subjects without migraine aura and 33 (13.0%) of 254 subjects with migraine aura had NDE (p < 0.001, odds ratio (OR) = 2.29). In multiple logistic regression analysis, migraine aura remained significant after adjustment for age (p < 0.001, OR = 2.31), gender (p < 0.001, OR = 2.33), or both (p < 0.001, OR = 2.33). Conclusions In our sample, migraine aura was a predictor of NDE. This indirectly supports the association between NDE and REM intrusion and might have implications for the understanding of NDE, because a variant of spreading depolarization (SD), terminal SD, occurs in humans at the end of life, while a short-lasting variant of SD is considered the pathophysiological correlate of migraine aura.

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Clark, Alfred V. "An NDE formability test for sheet metal". JOM 42, n.º 7 (julho de 1990): 48. http://dx.doi.org/10.1007/bf03221024.

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Skafidas, Panagiotis. "Non-Destructive Testing of Mechanical Properties of Magnetic Materials Using Barkhausen Noise and B-H Loop Techniques". Key Engineering Materials 495 (novembro de 2011): 272–75. http://dx.doi.org/10.4028/www.scientific.net/kem.495.272.

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A magnetic-based nondestructive evaluation (NDE) method, which employs Barkhausen effect and measurement of hysteresis loops, is developed and used to correlate the magnetic and mechanical properties. The NDE test equipment offers the capability to detect small deviations from linearity that occur in the stress-strain curve.

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Hotta, Naoshi, Takahiro Tadokoro, John Henry, Daisuke Koga, Keisuke Kawata, Hiroyuki Ishida, Yuko Oguma, Akihiro Hirata, Masato Mitsuhashi e Kenji Yoshitani. "Monitoring of Post-Brain Injuries By Measuring Plasma Levels of Neuron-Derived Extracellular Vesicles". Biomarker Insights 17 (janeiro de 2022): 117727192211281. http://dx.doi.org/10.1177/11772719221128145.

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Background: Extracellular vesicles (EV) released from neurons into the blood can reflect the state of nervous tissue. Measurement of neuron derived EV (NDE) may serve as an indicator of brain injury. Methods: A sandwich immunoassay was established to measure plasma NDE using anti-neuron CD171 and anti-EV CD9 ([CD171 + CD9+]). Plasma samples were obtained from commercial sources, cross-country (n = 9), football (n = 22), soccer (n = 19), and rugby (n = 18) athletes over time. Plasma was also collected from patients undergoing total aortic arch replacement (TAR) with selective cerebral perfusion during cardiopulmonary bypass before and after surgery (n = 36). Results: The specificity, linearity, and reproducibility of NDE assay (measurement of [CD171 + CD9+]) were confirmed. By scanning electron microscopy and nanoparticle tracking, spherical vesicles ranging in size from 150 to 300 nm were confirmed. Plasma levels of NDE were widely spread over 2 to 3 logs in different individuals with a significant age-dependent decrease. However, NDE were very stable in each individual within a ± 50% change over time (cross-country, football, soccer), whereas rugby players were more variable over 4 years. In patients undergoing TAR, NDE increased rapidly in days post-surgery and were significantly ( P = .0004) higher in those developing postoperative delirium (POD) (n = 13) than non-delirium patients (n = 23). Conclusions: The blood test to determine plasma levels of NDE was established by a sandwich immunoassay using 2 antibodies against neuron (CD171) and exosomes (CD9). NDE levels varied widely in different individuals and decreased with age, indicating that NDE levels should be considered as a normalizer of NDE biomarker studies. However, NDE levels were stable over time in each individual, and increased rapidly after TAR with greater increases associated with patients developing POD. This assay may serve as a surrogate for evaluating and monitoring brain injuries.

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Hesse, Alex A., Rebecca A. Atadero e Mehmet E. Ozbek. "Using Expert Opinion to Quantify Uncertainty in and Cost of Using Nondestructive Evaluation on Bridges". Advances in Civil Engineering 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/7925193.

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A previous literature review indicated that there is little published experimental data that can be used to determine quantities such as bias, accuracy, reliability, and cost of common Nondestructive Evaluation (NDE) methods as far as their use on bridges is concerned. This study attempts to quantify these parameters for common bridge NDE methods through a four-round Delphi method survey with experts in the NDE bridge field. The survey results indicate that most commonly used bridge NDE methods tend to be underbiased and relatively reliable. Furthermore, the accuracy of commonly used bridge NDE methods tends to be relatively variable with the average test measuring a true response between 80% and 85% of the time. In general, it was shown by the participant responses that the more expensive the method was, the better the bias, accuracy, and reliability the method had, and vice versa. The information presented in this paper can serve as a starting point for characterizing different NDE methods for use in bridge management and inspection planning and identifies the type of information that is still needed. As such, this research has the potential to promote further research on this subject.

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Dong, Jun Hua, Shan Na Xu, Wei Ke e Nan Chen. "The Effect of Cd Addition on NDE of As-Cast Mg-Cd Alloy in 0.1M NaCl Solution". Materials Science Forum 654-656 (junho de 2010): 779–82. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.779.

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The effect of Cd additions on NDE of an as-cast Mg-Cd alloy in 0.1M NaCl solution was investigated using the gas collection method, potentiostatic current decay test and in-situ Laser Raman Spectroscopy. The experimental results showed that, in the cathodic region the addition of Cd reduced the hydrogen evolution and the magnesium hydride formation; in the anodic region the addition of Cd restrained the NDE but slightly increased the anodic dissolution.

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Albakri, Mohammad I., Logan D. Sturm, Christopher B. Williams e Pablo A. Tarazaga. "Impedance-based non-destructive evaluation of additively manufactured parts". Rapid Prototyping Journal 23, n.º 3 (18 de abril de 2017): 589–601. http://dx.doi.org/10.1108/rpj-03-2016-0046.

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Purpose This work proposes the utilization of electromechanical impedance measurements as a means of non-destructive evaluation (NDE) for additive manufacturing (AM). The effectiveness and sensitivity of the technique for a variety of defect types commonly encountered in AM are investigated. Design/methodology/approach To evaluate the feasibility of impedance-based NDE for AM, the authors first designed and fabricated a suite of test specimens with build errors typical of AM processes, including dimensional inaccuracies, positional inaccuracies and internal porosity. Two polymer AM processes were investigated in this work: material jetting and extrusion. An impedance-based analysis was then conducted on all parts and utilized, in a supervised learning context, for identifying defective parts. Findings The newly proposed impedance-based NDE technique has been proven to be an effective solution for detecting several types of print defects. Specifically, it was shown that the technique is capable of detecting print defects resulting in mass change (as small as 1 per cent) and in feature displacement (as small as 1 mm) in both extruded nylon parts and jetted VeroWhitePlus parts. Internal porosity defects were also found to be detectable; however, the impact of this defect type on the measured impedance was not as profound as that of dimensional and positional inaccuracies. Originality/value Compared to currently available NDE techniques, the newly proposed impedance-based NDE is a functional-based technique with the advantages of being cost-effective, sensitive and suitable for inspecting AM parts of complex geometry and deeply embedded flaws. This technique has the potential to bridge the existing gaps in current NDE practices, hence paving the road for a wider adoption of AM to produce mission-critical parts.

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Alvarado, Carlos S., e Nancy L. Zingrone. "Factors Related to the Depth of Near-Death Experiences: Testing the “Embellishment over Time” Hypothesis". Imagination, Cognition and Personality 17, n.º 4 (junho de 1998): 339–44. http://dx.doi.org/10.2190/vyqp-867c-newq-f054.

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In this article we explore the correlation of several variables with the depth of the near-death experience (NDE) as measured by Ring's Weighted Core Experience Index (WCEI). For this purpose we analyzed fifty-one NDE cases presented by Sutherland in tabular form in her book Reborn in the Light [1]. To test for the possibility that older cases are embellished as time goes on we predicted that we would find a positive correlation between the WCEI and the time elapsed between the experience and Sutherland's interview. Other exploratory analyses attempted to relate the WCEI to sex, age at the time of the experience and at the time of the interview, and type of medical crisis during which the experience took place. None of the analyses conducted obtained significant results. There was a non-significant trend for surgical NDE cases to have higher scores in the WCEI than other conditions.

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Jaber, Ali, Sasan Sattarpanah Sattarpanah Karganroudi, Mohammad Saleh Meiabadi, Ahmad Aminzadeh, Hussein Ibrahim, Mehdi Adda e Hossein Taheri. "On Smart Geometric Non-Destructive Evaluation: Inspection Methods, Overview, and Challenges". Materials 15, n.º 20 (15 de outubro de 2022): 7187. http://dx.doi.org/10.3390/ma15207187.

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Inspection methods, also known as non-destructive evaluation (NDE), is a process for inspecting materials, products, and facilities to identify flaws, imperfections, and malfunctions without destruction or changing the integrity of materials, structures, and mechanisms. However, detecting those defects requires test conducting and results inferring, which is highly demanding in terms of analysis, performance, and time. New technologies are therefore needed to increase the efficiency, probability of detection, and interpretability of NDE methods to establish smart inspection. In this context, Artificial intelligence (AI), as a fundamental component of the Industry 4.0, is a well-suited tool to address downsides associated with the current NDE methods for analysis and interpretation of inspection results, where methods integrating AI into their inspection process become automated and are known as smart inspection methods. This article sheds a light on the conventional methods and the smart techniques used in defects detection. Subsequently, a comparison between the two notions is presented. Furthermore, it investigates opportunities for the integration of non-destructive evaluation (NDE) methods and Industry 4.0 technologies. In addition, the challenges hindering the progress of the domain are mentioned as the potential solutions. To this end, along with Industry 4.0 technologies, a virtual inspection system has been proposed to deploy smart inspection.

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Wilcox, Paul D., Anthony J. Croxford, Nicolas Budyn, Rhodri L. T. Bevan, Jie Zhang, Artem Kashubin e Peter Cawley. "Fusion of multi-view ultrasonic data for increased detection performance in non-destructive evaluation". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 476, n.º 2243 (novembro de 2020): 20200086. http://dx.doi.org/10.1098/rspa.2020.0086.

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State-of-the-art ultrasonic non-destructive evaluation (NDE) uses an array to rapidly generate multiple, information-rich views at each test position on a safety-critical component. However, the information for detecting potential defects is dispersed across views, and a typical inspection may involve thousands of test positions. Interpretation requires painstaking analysis by a skilled operator. In this paper, various methods for fusing multi-view data are developed. Compared with any one single view, all methods are shown to yield significant performance gains, which may be related to the general and edge cases for NDE. In the general case, a defect is clearly detectable in at least one individual view, but the view(s) depends on the defect location and orientation. Here, the performance gain from data fusion is mainly the result of the selective use of information from the most appropriate view(s) and fusion provides a means to substantially reduce operator burden. The edge cases are defects that cannot be reliably detected in any one individual view without false alarms. Here, certain fusion methods are shown to enable detection with reduced false alarms. In this context, fusion allows NDE capability to be extended with potential implications for the design and operation of engineering assets.

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Satyarnarayan, L., D. M. Pukazhendhi, Krishnan Balasubramaniam, C. V. Krishnamurthy e D. S. Ramachandra Murthy. "Phased Array Ultrasonic Measurement of Fatigue Crack Growth Profiles in Stainless Steel Pipes". Journal of Pressure Vessel Technology 129, n.º 4 (24 de julho de 2006): 737–43. http://dx.doi.org/10.1115/1.2767367.

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This paper reports experimental sizing of fatigue crack profiles that are initiated from artificially made circumferential starter notches in stainless steel pipes of 169mm outer diameter and 14.33mm thickness, which were subjected to cyclic bending loads in a four point bending load arrangement using two nondestractive evaluation (NDE) methods: (a) phased array ultrasonic technique and (b) alternating current potential drop technique. The crack growth estimated using the two NDE techniques were compared with the beach marks that were present in the fracture surface. A simulation study using the ray tracing method was carried out to model the ultrasonic wave propagation in the test specimen, and the results were compared with the experimental results.

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Prasanna, N. Gnana, R. Rajkumar e F. Michael Raj. "Non-destructive evaluation from deformed aluminum alloy 6063 and silicon carbides black and green reinforced aluminium alloy based composites". Materials Express 12, n.º 3 (1 de março de 2022): 435–45. http://dx.doi.org/10.1166/mex.2022.2166.

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In this work, tensile mechanical properties of the aluminum alloy 6063 (AA6063) with reinforced silicon carbides (SiC) black and green aluminium based composites and the deformed specimens are analyzed using nondestructive evaluation (NDE) of ultrasonic inspections. The specimens making of various weight proportions and its manufacturing of stir casting technique. After tensile test the deformed specimens measure the surfaces using scanning electron microscope (SEM) and Energy Dispersive X-ray spectrum (EDX). Also, conduct the salt spray test of the deformed specimens and compare the surfaces at before and after the deformation. The deformed specimen for NDE was observed interruption, twinning and debonding in onset of plastic deformation of the matrix interfaces. However, the interaction moment was significantly influence by the load bearing capacity from the reinforcement to the matrix. The result was showed that AA6063 with SiC black and green composites are better tensile mechanical properties and better surface integrity was investigated. Furthermore, the regression analysis shows that the variations of interfaces on AA6063 with SiC black and green composites and the factors influenced by the tensile properties, salt spray test and ultrasonic test are found significant and the MMCs are the specific applications of automotive industries.

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Sultan, Ali A., e Glenn A. Washer. "Comparison of Two Nondestructive Evaluation Technologies for the Condition Assessment of Bridge Decks". Transportation Research Record: Journal of the Transportation Research Board 2672, n.º 41 (23 de agosto de 2018): 113–22. http://dx.doi.org/10.1177/0361198118790835.

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Selection of the appropriate condition assessment tool to meet the decision-making needs for preservation, maintenance, and repair (PM&R) actions can be difficult, because different nondestructive evaluation (NDE) technologies have different performance characteristics. The objective of the research was to compare the reliability of ground-penetrating radar (GPR) and infrared thermography (IRT) for the detection of delamination in concrete bridge decks. Field tests were conducted on two in-service concrete decks constructed in the same era and having significant deterioration due to corrosion damage. Reliability of the technologies was evaluated using receiver operator characteristics (ROC) analysis, a methodology that allows for a quantitative point-by-point comparison of results from NDE technologies with ground truth. The analysis results quantified the reliability of IRT and GPR for the two candidate concrete decks. It was found that IRT exhibited a higher reliability measure as compared with GPR for these two bridge decks. The implication of the test results for implementation of these technologies is discussed. The results of the analysis provide useful data for bridge owners making decisions regarding suitable NDE technologies for the condition assessment of bridge decks.

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Kim, Jeong Guk. "Tensile Damage Characterization in Nicalon Fiber Reinforced Ceramic Composites". Key Engineering Materials 326-328 (dezembro de 2006): 1237–42. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.1237.

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Tensile failure behavior of ceramic matrix composites (CMCs) was characterized with nondestructive evaluation (NDE) techniques. Prior to the mechanical testing, infrared (IR) thermography was employed to obtain thermal diffusivity maps for CMC specimens. IR thermography also was used for quantitative analyses of the progressive damage and in-situ monitoring of the damage during tensile tests, while ultrasonic (UT) C-scans were used to present defect distributions of the composites. The thermal diffusivity map showed good consistency with ultrasonic C-scan results of CMC specimens. In this investigation, qualitative relationship between UT signatures and thermal diffusivity has been introduced, and the temperature changes of CMC specimens during tensile test have been measured. Moreover, the correlation between NDE results and fracture behavior of CMCs has been presented to understand tension fracture behavior of CMCs.

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Ruan, J. T., F. Aymerich, J. W. Tong e Z. Y. Wang. "Optical Evaluation on Delamination Buckling of Composite Laminate with Impact Damage". Advances in Materials Science and Engineering 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/390965.

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The delamination buckling and growth behaviors of a cross-ply composite laminate with damage induced by low velocity impact are investigated optically using three-dimensional digital image correlation (3D-DIC) method. For the 3D deformation measurement, the 3D-DIC setup comprised of two CCD cameras was adopted. The rectangle specimen was impacted under the impact energy of 7.0 J using a drop-weight testing machine, and the impact damage was detected by means of X-ray nondestructive evaluation (NDE) technique. The 3D deformation field measured with the optical system clearly reveals that the delamination buckling characteristic of the specimen mainly appears local deformation mode under compression after impact test. Moreover, the behavior of delamination growth evaluated by the 3D-DIC optical method reasonably agrees with the NDE observed damage result after compression.

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Hahn, F., C. W. Kensche, R. J. H. Paynter, A. G. Dutton, C. Kildegaard e J. Kosgaard. "Design, Fatigue Test and NDE of a Sectional Wind Turbine Rotor Blade". Journal of Thermoplastic Composite Materials 15, n.º 3 (maio de 2002): 267–77. http://dx.doi.org/10.1177/0892705702015003455.

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Dahiya, Ekta, Man Mohan Mehndiratta e Krishna Pillai. "Plasma tetranectin as a potential clinical biomarker for epilepsy and correlation with clinical and social characteristics". International Journal of Epilepsy 04, n.º 01 (junho de 2017): 002–5. http://dx.doi.org/10.1016/j.ijep.2016.12.003.

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Abstract Background Tetranectin concentration has been identified as a biomarker of several types of metastatic and malignant cancers. The role of tetranectin has also be seen in some neurological disorders. We aimed to estimate the plasma tetranectin concentration in different groups of people with epilepsy (PWE) followed-up for a year. As a secondary objective, the clinical and social characteristics were also correlated with the tetranectin levels. Methods We enrolled 90 subjects grouped as Newly-diagnosed epilepsy (NDE), Drug-effective epilepsy (DEE), and Drug-refractory epilepsy (DRE) and an age-gender matched control group (n = 30). The plasma samples were collected thrice at the six-month interval and were analysed for the tetranectin concentration using S-ELISA. Results The mean plasma tetranectin levels at the baseline test were significantly lower for the DEE (6.294 ± 0.806) and DRE (7.572 ± 0.545) groups compared with control group (9.71 ± 0.628) but not the NDE group (8.651 ± 0.859 vs. 9.71 ± 0.628; p > 0.05). On a year of follow-up, the tetranectin levels for the NDE group significantly decreased (p < 0.001) matching with that of the DEE and DRE group. Multivariate linear regression analysis showed that gender (p = 0.035) in the DRE group and seizure type (p = 0.040) and diet (p = 0.046) for the NDE group were significantly correlated. Conclusion The plasma tetranectin level in PWE significantly decreased as the disease progressed irrespective of the stage of epilepsy. Thus, tetranectin could be considered as a potential progressive biomarker for epilepsy. The study outcome suggests further investigation for the possible link of tetranectin levels with clinical and social parameters.

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Ahmed, Marwa, Osama Moselhi e Anjan Bhowmick. "Two-tier data fusion method for bridge condition assessment". Canadian Journal of Civil Engineering 45, n.º 3 (março de 2018): 197–214. http://dx.doi.org/10.1139/cjce-2017-0160.

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Fusing collected inspection data provides comprehensive and relatively more accurate diagnostics of defects and accordingly more accurate condition assessment of structures. This paper presents a new two-tier method that utilized data fusion methods for condition assessment of reinforced concrete bridge decks. The method utilizes pixel and feature levels fusion of data collected from multiple nondestructive evaluation (NDE) methods such as ground penetrating radar, impact echo, half-cell potential, and electrical resistivity. Data and measurements of NDE methods are extracted from the Iowa Highway research board project 2011 report for three case studies. It is observed from the three cases that each level of data fusion has its unique advantage. The power of pixel level fusion lies in its ability to provide an overview of bridge deck deterioration in one map as it appears in the fused image. On the other hand, feature fusion works better when only specific types of defects such as corrosion, delamination, and deterioration captured from inspection carried out by each of technologies referred to above. The proposed method is tested against filed inspection methods and core sample results described in the three case studies. The main findings of this research recommend utilizing data fusion in two levels as a new method to facilitate and enhance the confidence and capabilities of inspectors in interpretation of the NDE test results.

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Schecklman, Scott, e Lisa Zurk. "Terahertz Imaging of Thin Film Layers with Matched Field Processing". Sensors 18, n.º 10 (19 de outubro de 2018): 3547. http://dx.doi.org/10.3390/s18103547.

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Terahertz (THz) time of flight (TOF) tomography systems offer a new measurement modality for non-destructive evaluation (NDE) of the subsurface layers of protective coatings and/or laminated composite materials for industrial, security and biomedical applications. However, for thin film samples, the time-of-flight within a layer is less than the duration of the THz pulse and consequently there is insufficient range resolution for NDE of the sample under test. In this paper, matched field processing (MFP) techniques are applied to thickness estimation in THz TOF tomography applications, and these methods are demonstrated by using measured THz spectra to estimate the the thicknesses of a thin air gap and its depth below the surface. MFP methods have been developed over several decades in the underwater acoustics community for model-based inversion of geo-acoustic parameters. It is expected that this research will provide an important link for THz researchers to access and apply the robust methods available in the MFP literature.

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Sobenin, Igor A., Margarita A. Sazonova, Anton Y. Postnov, Yuri V. Bobryshev e Alexander N. Orekhov. "Mitochondrial Mutations are Associated with Atherosclerotic Lesions in the Human Aorta". Clinical and Developmental Immunology 2012 (2012): 1–5. http://dx.doi.org/10.1155/2012/832464.

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Somatic mutations of the human mitochondrial genome can be a possible determinant of atherosclerosis. To test this possibility, forty mitochondrial mutations were analyzed in the present study in order to see which of these mutations might be associated with atherosclerosis. Ten mitochondrial mutations belonging to mitochondrial genes MT-RNR1 (rRNA 12S); MT-TL1 (tRNA-Leu, recognizes UUR); MT-TL2 (tRNA-Leu, recognizes CUN); MT-ND1, MT-ND2, MT-ND5, and MT-ND6 (subunits 1, 2, 5, and 6, respectively, of NADH dehydrogenase); and MT-CYB (cytochrome b) were potentially associated with atherosclerosis. From 29% (2 of 7 aortic samples) upto 86% (6 of 7 aortic samples) of aortic samples had a significant difference between atherosclerotic plaques and unaffected tissue, with the respect to the level of heteroplasmy for each mutation. Further, the homogenates of affected and normal intimae of 22 aortas were compared to reveal the average level of heteroplasmy for the above-mentioned 10 mutations. For five mutations, the mean level of heteroplasmy was significantly different in atherosclerotic intimal homogenates in comparison with the unaffected tissue. These mutations were A1555G, C3256T, T3336C, G13513A, and G15059A. Thus, it was demonstrated that at least five mitochondrial mutations occurring in MT-RNR1, MT-TL1, MT-ND2, MT-ND5, and MT-CYB genes are associated with atherosclerosis.

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Xu, Shanna, Junhua Dong e Wei Ke. "Effect of Magnesium Hydride on the Corrosion Behavior of Pure Magnesium in 0.1 M NaCl Solution". International Journal of Corrosion 2010 (2010): 1–5. http://dx.doi.org/10.1155/2010/934867.

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The effect of magnesium hydride on the corrosion behavior of pure magnesium in 0.1 M NaCl solution was investigated using the gas collection method, potentiostatic current decay test, and in situ Raman spectrum. The formation of magnesium hydride (MgH2,Mg2H4) was observed at the cathodic region. Applying anodic potential leads to decomposition of magnesium hydride. Magnesium hydride plays an important role on the negative difference effect (NDE) in both the cathodic and anodic regions.

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Yang, Peiji, Qi Yuan, Chao Huang, Yafeng Zhou, Hongliang Li e Yu Zhou. "Analysis of the Impacts of Bearing on Vibration Characteristics of Rotor". Shock and Vibration 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/8098591.

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Aiming at a Top Gas Recovery Turbine Unit (TRT) with double support rotor and the extending disk end, theoretical and experimental analysis about influence of cylindrical bearing and four-lobe bearing on vibration of TRT rotor system are conducted in this paper. The results indicate that vibration of the rotor supported by cylindrical bearing is more stable than that supported by four-lobe bearing at the driving end (DE) and the nondriving end (NDE). The amplitude of rotor is supported by both of these types of bearing increases as the speed increases at the NDE, while the amplitude of the DE remains unchanged. Comparing with the result of theoretical analysis, the practical test results are more consistent with the theoretical response analysis conducted by applying unbalanced mass at the extending disk end. This paper presents an analysis method of the critical characteristics of a double support rotor system with the extending disk end and provides reference value for dealing with vibration fault of double support rotor system with the extending disk end.

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Chen, Le, Yue Min Wang e Hai Quan Geng. "Flaw Detection in Aluminum Plate by Shear Horizontal Guided Wave Based on Magnetostriction EMAT". Applied Mechanics and Materials 614 (setembro de 2014): 287–90. http://dx.doi.org/10.4028/www.scientific.net/amm.614.287.

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Shear horizontal (SH) guided waves have been proved to be a viable method in the Non-Destructive Evaluation (NDE). Electromagnetic acoustic transducers (EMAT) can excite SH waves easily. By bonding the Fe-Co alloy to the test sample, the SH guided waves based on magnetostriction effect can be used to detect the flaw in nonferromagnetic material. The principle of exciting and receiving SH waves is introduced, and an experiment is carried out to validate the result.

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Nychka, J. A., D. R. Clarke, S. Sridharan, E. Jordan, M. Gell, M. J. Lance, C. J. Chunnilall et al. "NDE assessment of TBCs: an interim report of a photo-stimulated luminescence ‘round-robin’ test". Surface and Coatings Technology 163-164 (janeiro de 2003): 87–94. http://dx.doi.org/10.1016/s0257-8972(02)00596-0.

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Zhong, Xiao Yong, e Xiao Hong Zhang. "Research of On-Line Detection Apparatus for Industrial Steel Wire Rope". Applied Mechanics and Materials 48-49 (fevereiro de 2011): 924–27. http://dx.doi.org/10.4028/www.scientific.net/amm.48-49.924.

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A new type of steel wire rope non destructive evaluation (NDE) apparatus is presented. It is composed of Hall sensor and signal processing system based on embedded micro processor. The apparatus detects flaws of steel wire rope real-time and on-line. The detection principle, hardware structure and software design of the apparatus are introduced. Examples of the application are given. The experiment results show that quantitatively defect detection of steel wire rope is attained. The apparatus can also be used for the test of the ferromagnetic bars.

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Panjsetooni, Alireza, Norazura Muhamad Bunnori e Amir Hossein Vakili. "Damage Source Identification of Reinforced Concrete Structure Using Acoustic Emission Technique". Scientific World Journal 2013 (2013): 1–5. http://dx.doi.org/10.1155/2013/870585.

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Acoustic emission (AE) technique is one of the nondestructive evaluation (NDE) techniques that have been considered as the prime candidate for structural health and damage monitoring in loaded structures. This technique was employed for investigation process of damage in reinforced concrete (RC) frame specimens. A number of reinforced concrete RC frames were tested under loading cycle and were simultaneously monitored using AE. The AE test data were analyzed using the AE source location analysis method. The results showed that AE technique is suitable to identify the sources location of damage in RC structures.

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Bemis, R. A., K. Shiloh e W. A. Ellingson. "Nondestructive Evaluation of Thermally Shocked Silicon Carbide by Impact-Acoustic Resonance". Journal of Engineering for Gas Turbines and Power 118, n.º 3 (1 de julho de 1996): 491–94. http://dx.doi.org/10.1115/1.2816673.

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Monolithic ceramics are under consideration as structural components for hot-stage sections of gas-fired turbine engines. In addition to manufacturing quality control, other important aspects for this application include life prediction modeling and time between engine overhauls. One nondestructive evaluation (NDE) method that provides information about material condition involves an analysis of resonant vibrations. In previous work by this general approach, changes in modal parameters have been related to bulk defect mechanisms such as microcracking due to thermal shock damage. In this work resonant vibrations from monolithic ceramic specimens were excited by an instrumented impact hammer and detected by a noncontact acoustic microphone over frequencies up to 100 kHz. Computer-based analysis of vibration signatures from test specimens allowed extraction of modal frequencies and damping constants. Downward shifts in detected resonant frequencies and increases in internal friction or (specific) damping capacity measurements were obtained from SiC cylindrical rings, and these measurements were shown to relate to thermal shock severity. This NDE method not only provides measurable parameters that could be used as accept–reject criteria for in-line process inspection, it also provides a means for tracking the mechanical integrity of in-service engine components to support life prediction modeling.

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Srinivas, V. Karthik, e A. K. Lakshminarayanan. "On the Local Constitutive Behavior of Friction Stir Welded AISI 304 Stainless Steel Joints". Materials Science Forum 979 (março de 2020): 107–13. http://dx.doi.org/10.4028/www.scientific.net/msf.979.107.

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The uniaxial tensile test is often used to determine the mechanical properties of a material like its yield strength and elastic limit. However, some of the recent advances in imaging Non Destructive Evaluation (NDE) modalities offer experimental tools which, apart from determining the conventional properties, also make it possible to visualise and map the dynamic strain evolution during monotonic loading and correlate it with the micro mechanisms of deformation. Infrared thermal imaging (IRT) and digital image correlation (DIC) are two such advanced NDE methods which are being widely used in experimental mechanics. Infrared thermal imaging maps the thermal gradient including the dynamic thermal transients that may occur during the tensile testing and is based on the detection of infrared radiation. Digital image correlation, a non-contact optical method based on grey value correlation before and after deformation, maps the magnitude of deformation on the surface of the object under load. In this investigation, the global and local properties of a friction stir welded joint of 304 Austenitic Stainless steel through the simultaneous application of thermal imaging and digital image correlation. By characterising the various stages of tensile deformation, this study enabled correlation of the thermal and strain evolutions and to provide deeper insights into the micro-mechanisms of the associated deformation phenomenon.

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Chen, Hong Lei, Fei Deng e Xi Zhang. "Defect Imaging via Chirp Signal Excitation in Plate". Advanced Materials Research 846-847 (novembro de 2013): 826–30. http://dx.doi.org/10.4028/www.scientific.net/amr.846-847.826.

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The chirp signal can bring some useful information for structural non-destructive evaluation (NDE) applications due to its broad frequency components with different sensitivity to defects that exist in test pieces. This paper introduces a defect imaging method based on the chirp signal. When a chirp signal is used as excitation in the guided wave detection system, tone burst results can be gotten from the response easily. Numerical simulation results show that this method simplifies the procedure to find the best exciting frequency and guided wave mode for the hole defect detection, and yields more accurate defect imaging results with arc imaging algorithm.

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Mahdavi, Mohammad Ebrahim, Maryam Rezaeian, Homa Zarrinkoob, Mohsen Rezaeian e Alireza Akbarzadeh. "Effect of a Dichotic Interaural Time Difference Program on Dichotic Listening Deficit of Children with Learning Difficulty". Journal of the American Academy of Audiology 32, n.º 05 (maio de 2021): 295–302. http://dx.doi.org/10.1055/s-0041-1728753.

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Abstract Background Dichotic listening deficit (DLD) is a common sign in children showing learning problem and is identified during auditory processing assessment. A dichotic listening training program was developed in which the weak ear lags behind the strong ear in time and has certain practices for switching attention between the ears and auditory memory. Purpose The aim of the present study was to evaluate the effectiveness of this treatment program on dichotic performance of primary school children showing DLD. Research Design A pre/post clinical trial without control study. Study Sample Twenty-five primary school children, aged 7 to 12 years (mean = 9.3 years), showing DLD. Data Collection and Analysis Several primary schools referred the children with learning difficulty to us. We defined learning difficulty as a score of 2 and lower on a five-point scale in at least two primary school courses in the current semester. The children with DLD participated in listening practices three times a week for 10 weeks, each session lasting for 30 minutes. The practices started with one pair of dichotic digits and ended in practice with sentences. The weak ear lag varied from 100 to 1,000 milliseconds. In the last stage of the practices, the precued and postcued directed response aimed at strengthening auditory memory and switching attention between the ears. The results obtained by the tests of dichotic digits, competing words, and competing sentences before and after the intervention were compared using paired t-test. Hedges's g was calculated as the effect size. Results Comparison of the results of pretraining and those of posttraining revealed that the average dominant ear (DE) and nondominant ear (NDE) scores in dichotic listening tests improved significantly with medium-to-large effect sizes. It was also found that the mean change in the NDE score of the children was significantly greater than that of the DE score for all the tests. Conclusions Dichotic interaural time difference training that employed dichotic lag phenomenon followed by directed response practices significantly improved the DE and the NDE scores of the schoolchildren with DLD.

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PARK, YOUNG-CHUL, JIN-KYUNG LEE, SANG-PILL LEE, GYU-CHANG LEE, JOON-HYUN LEE, YOUN-HO CHO e JONG-BACK LEE. "A STUDY ON FATIGUE DAMAGE OF SHAPE MEMORY ALLOY COMPOSITE USING NDE TECHNIQUE". International Journal of Modern Physics B 20, n.º 25n27 (30 de outubro de 2006): 3775–80. http://dx.doi.org/10.1142/s0217979206040350.

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TiNi shape memory alloy was used to recover the shape of transformed objects using its shape memory effect. This shape memory effect plays an important role inside metal matrix composite. A composite using shape memory alloy has a large advantage that can control crack initiation and propagation, when compared with other composites due to the shape memory effect of shape memory alloy under high temperature. In this study, TiNi/Al6061 and TiNi/2024 shape memory composites were fabricated by the hot press method, and a fatigue test was performed to evaluate the fatigue damage for the shape memory composites under room temperature and high temperature. The relationship of the crack growth rate and the stress intensity factor for these shape memory composites were clarified at both temperature conditions. The delay effect of crack propagation due to shape memory alloy was also evaluated under high temperature. In addition, an acoustic emission technique was used to evaluate the crack initiation and the control of crack propagation by shape memory effect under fatigue test nondestructively. The relationship between AE parameter and the degree of fatigue damage of the shape memory composites was discussed.

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Saboktakin, A., e T. Vu-Khanh. "Performance assessment of textile composite using NDE and mechanical testing techniques". International Journal of Structural Integrity 5, n.º 1 (11 de março de 2014): 17–29. http://dx.doi.org/10.1108/ijsi-04-2013-0007.

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Purpose – Quality assessment of textile composites needs to have sufficient knowledge about the various types of non-destructive testing techniques to detect defects as well as the effect of these defects on mechanical performance. The paper aims to discuss these issues. Design/methodology/approach – The major approach of this paper was to evaluate the potential of two inspection techniques named ultrasounds, vibrations for detecting textile reinforcement defects in composites and evaluate the composite performance in the presence of a damage. Findings – Potential solutions have been identified to solve the issue of signal attenuation observed during C-scan ultrasonic testing, and the criticality of initial defects on static test was determined. Originality/value – The research work presented here has been a first attempt to apply the combination of different techniques in particular polar scan for the textile composite inspection. This will become more crucial as requirements for high performance and complex shape textile composite parts.

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Chulya, A., J. P. Gyekenyesi e R. T. Bhatt. "Mechanical Behavior of Fiber-Reinforced SiC/RBSN Ceramic Matrix Composites: Theory and Experiment". Journal of Engineering for Gas Turbines and Power 115, n.º 1 (1 de janeiro de 1993): 91–102. http://dx.doi.org/10.1115/1.2906691.

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The mechanical behavior of continuous fiber-reinforced SiC/RBSN composites with various fiber contents is evaluated. Both catastrophic and noncatastrophic failures are observed in tensile specimens. Damage and failure mechanisms are identified via in-situ monitoring using NDE techniques throughout the loading history. Effects of fiber/matrix interface debonding (splitting) parallel to the fibers are discussed. Statistical failure behavior of fibers is also observed, especially when the interface is weak. Micromechanical models incorporating residual stresses to calculate the critical matrix cracking strength, ultimate strength, and work of pull-out are reviewed and used to predict composite response. For selected test problems, experimental measurements are compared to analytic predictions.

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Evanson, S., M. Otaka e K. Hasegawa. "SQUID NDE Apparatus and Magnetic Calibration to Detect Degradation in Duplex Stainless Steel". Journal of Engineering Materials and Technology 114, n.º 1 (1 de janeiro de 1992): 41–45. http://dx.doi.org/10.1115/1.2904138.

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We report on apparatus for the magnetic material characterization of a wide range of steel grades of high and low magnetic permeability. The instrument has been used to detect thermal aging in Duplex steel by the measurement of the residual magnetization (Br) of test specimens. A method to estimate the value of Br by remote measurements up to 200 mm from a specimen is described. The results are compared with data from conventional hysteresis loop measurements.

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Gyekenyesi, A. L. "Thermoelastic Stress Analysis: An NDE Tool for Residual Stress Assessment of Metallic Alloys". Journal of Engineering for Gas Turbines and Power 124, n.º 2 (26 de março de 2002): 383–87. http://dx.doi.org/10.1115/1.1417982.

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The primary objective of this report involves studying and developing various experimental techniques for accurate measurement of the mean stress effect in thermoelastic stress analysis (TSA, also recognized as SPATE: stress pattern analysis by thermal emission). The analysis of cyclic mean stresses at the coupon level directly relates to the measurement of residual stresses in structures. In a previous study by the authors, it was shown that cyclic mean stresses significantly influenced the TSA results for titanium and nickel-based alloys, although, difficulties were encountered concerning the quantification of the mean stress effect because of large test-to-test variations. This study continues the effort of accurate direct measurements of the mean stress effect by implementing various experimental modifications. In addition, a more in-depth analysis is included which involves analyzing the second harmonic of the temperature response. By obtaining the amplitudes of the first and second harmonics, the stress amplitude and the mean stress at a given point on a structure subjected to a cyclic load can be simultaneously obtained. The rather complex analysis of the temperature response involves obtaining the first and second harmonic amplitudes for 16384 infrared detectors (128×128 focal plane array). Upon establishing a protocol for mean stress measurements in the laboratory using the TSA technique, the next step is to utilize the method to assess residual stress states in complex structures during manufacturing and life.

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Xie, Xin Chun, Jin Sen Zhang, Dong Yu Xu, Xiao Jing Guo, Fei Sha e Shi Feng Huang. "Fabrication of 1-3 Cement-Based Piezoelectric Ultrasonic Sensors for NDE Applications". Applied Mechanics and Materials 575 (junho de 2014): 580–84. http://dx.doi.org/10.4028/www.scientific.net/amm.575.580.

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This paper described fabrication and comparison of embedded ultrasonic sensors for NDE applications. A 1-3 cement-based piezoelectric composite was used as the sensing element of the ultrasonic sensor. As a front matching layer between test material and piezoelectric materials, cement/epoxy resin was selected. In order to make the backing materials for sensors had enough acoustic attenuation performance, the backing material of sensors doped with tungsten powder. When the mass ratio of tungsten/cement backing was two and the thickness of cement/epoxy resin front-face matching was 3mm, the 1-3 cement-based piezoelectric ultrasonic sensor showed a significant enhancement in both relative pulse-echo sensitivity and-6dB bandwidth. These promising results suggested the great potential for developing high-performance ultrasonic sensors using the 1-3 cement-based piezoelectric composite.

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Akunne, Theophine C., Bonaventure C. Obi, Martha N. Ofokansi, Patience C. Nwonu e Charles O. Okoli. "ANTIDIABETIC ACTIVITY AND TOXICOLOGICAL EVALUATION OF THE METHANOL-DICHLOROMETHANE ROOT BARK EXTRACT OF NAUCLEA DIDERRICHII (DE WILD) MERR". International Journal of Pharmacy and Pharmaceutical Sciences 9, n.º 9 (14 de agosto de 2017): 279. http://dx.doi.org/10.22159/ijpps.2017v9i9.20556.

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Objective: In southeastern Nigeria, Nauclea diderrichii (De Wild) Merr is used in the treatment of a wide range of ailments including diabetes mellitus (DM). This study evaluates the antidiabetic activity and toxicological profile of the methanol-dichloromethane root bark extract of N. diderrichii in normoglycemic and alloxan-induced diabetic models.Methods: Dried root barks of N. diderrichii were extracted using methanol and dichloromethane (1:1) to obtain N. diderrichii extract (NDE). The acute and sub-chronic toxicity tests were performed using standard procedures. The effect on alanine aminotransferase (ALT) aspartate aminotransferase (AST), alkaline phosphatase (ALP), total protein (TP), packed cell volume (PCV), hemoglobin concentration (HB) and total white blood cell (TWBC) count was determined in the rats after treatment. In order to elucidate its antidiabetic mode of action, an oral glucose tolerance test (OGTT) was performed using glucose (2 g/kg) as substrate and alloxan (100 mg/kg; i. v.) induced diabetic model. Glibenclamide (GLI 0.2 mg/kg) was used as the reference standard drug.Results: The results indicated that the LD50 of the extract is>5000 mg/kg. ALT, AST, ALP PCV, HB and TWBC were insignificantly (p>0.05) different compared with the control. No significant changes were observed in the organ weights compared with the control. In the acute and prolonged antidiabetic study, NDE (100, 200 and 400 mg/kg) significantly reduced the blood glucose level (BGL) by 14.66, 18.9, 25.80% and 75.11, 80.24, 83.74% respectively. In comparison, GLI, when administered, reduced BGL by 38.18 and 92.86% respectively.Conclusion: N. diderrichii possesses antidiabetic activity with good toxicological profile.

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Jin, Han Xun, Chen Bo Yin, Ming Guo e Yue Gong. "The Research of Remanufacturing Technology Applied to Lifting Machinery". Applied Mechanics and Materials 541-542 (março de 2014): 530–33. http://dx.doi.org/10.4028/www.scientific.net/amm.541-542.530.

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Lifting machinery usually fail or become scrapped after a certain period of use for a variety of reasons. Thus, they often need remanufacturing technology. The purpose of this paper is to research and analyze how to apply remanufacturing technology to lifting machinery. In this paper, the background of remanufacturing technology is firstly discussed. Then illuminate the specific processes of remanufacturing technology including the cleaning measures of those components after dismantled, the non-destructive examination (NDE), and assessment software using to test the perfectness of the produces remanufactured. Finally, the benefits of the widespread use of remanufactured lifting machinery which can make the best use of various resources to achieve energy saving, material saving and environment protection goals are discussed in order to draw key conclusions.

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Artana, I. G. W., W. G. Ariastina e I. N. S. Kumara. "RANCANG BANGUN SISTEM PEMANTAU SUHU BEARING MOTOR UNTUK POMPA SIRKULASI AIR BERBASIS IOT". Jurnal SPEKTRUM 9, n.º 2 (30 de junho de 2022): 20. http://dx.doi.org/10.24843/spektrum.2022.v09.i02.p3.

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The importance of monitoring the temperature of the motor bearing on the water circulation pump on a regular basis to prevent pump operation failures due to bearing. The operator monitors the temperature bearing manually using a Flir measuring instrument with potential hazards in the work area namely slipping, falling and electrocution. On this basis, IoT based bearing monitoring system for circulation water pump in real time is very necessary.The design of this prototype uses hardware such as ESP32 microcontroller and MLX90614-BCC sensor, while the software used are blynk and google spreadsheet. The MLX90614-BCC sensor calibration uses a linear regression method to adjust the sensor value to the Flir TG167 so as to minimize deviations in temperature readings.The results of this prototype are able to read temperature bearing well which are integrated with the blynk on smartphones by displaying temperature values in the form of numbers and graphs and also equipped with a notification. The prototype that was built had an average measurement deviation of 0.32% on the DE sensor and 0.3% on the NDE sensor. Storage of temperature data on google spreadsheet with the amount of data that can be stored as much as 1,666,666 data. The conclusion of the research is that it has succeeded in designing and manufacturing a prototype IoT based bearing monitoring system for circulation water pump. Testing the performance of the prototype can work well. The results of the prototype test on bearing for the water circulation pump showed that DE and NDE bearing temperatures were still below 55 °C and there was no notification on the smartphone which indicates the motor bearing is still in normal condition.

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ONO, M., W. NAKAO, K. TAKAHASHI, K. ANDO e M. NAKATANI. "SMS-17: Crack-healing+Proof Test : A New Methodology to Guarantee the Reliability of a Ceramics Component(SMS-III: SMART MATERIALS AND STRUCTURES, NDE)". Proceedings of the JSME Materials and Processing Conference (M&P) 2005 (2005): 35. http://dx.doi.org/10.1299/jsmeintmp.2005.35_2.

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Ünal, Bengü Türkyılmaz, Oğuzhan Mentiş e Ethem Akyol. "Elma Bitkisi (Malus domestica L.)’nde Foliar Uygulanan Salisilik Asitin Donmaya Karşı Etkileri". Turkish Journal of Agriculture - Food Science and Technology 3, n.º 5 (14 de janeiro de 2015): 221. http://dx.doi.org/10.24925/turjaf.v3i5.221-225.266.

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In our study we aim to increase frost resistance and improve the yield and quality of apple is important in Turkey and world economy. Phenological and morphological observations, physiological and biochemical analyzes were carried out in apple (Malus domestica L.) plants. It was studied to determine the effects of foliar Salicylic acid (0, 500 ppm/plant and 1000 ppm/plant) on adaptation of this plant when exposed to freezing stress, the quality and yield. Leaf photosynthetic pigment contents, total protein amount, proline amount, superoxide dismutase and peroxidase enzymatic activities were measured. The study planned by random experimental design and statistical analysis of data with SPSS program (LSD test) were made. It was determined that fruit and shoot numbers were increased in samples exposed to 500 ppm salicylic acid and while fruit weights were increased in samples exposed to 500 ppm and 1000 ppm salicylic acid compared to the control. Also, colour of plants were darkened. Chla, chlb, total chl, proline, superoxide dismutase and peroxidase amounts were increased significantly compared to the control group. Increases occured in the carotenoid and the protein amounts are not significant statistically. In the light of obtained data, foliar application of salicylic acid were found to reduce the effects of freezing stress and to increase the yield and quality of apple plants.

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Rose, J. L., A. Pilarski, K. Balasubramaniam, A. Tverdokhlebov e J. Ditri. "Ultrasonic Wave Considerations for the Development of an NDE Feature Matrix for Anisotropic Media". Journal of Engineering Materials and Technology 111, n.º 3 (1 de julho de 1989): 255–62. http://dx.doi.org/10.1115/1.3226464.

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The problem of ultrasonic surface and bulk wave propagation in an anisotropic media and/or a composite material is addressed so that applications in Nondestructive Evaluation can be considered, emphasis in this paper being placed on bulk wave propagation. Global material property determination is considered in an inverse wave velocity computation of stiffness coefficients based on principles of anisotropic elasticity. A one-sided inspection technique based on practical considerations of a field environment is developed. The concept of a feature matrix, based on the stiffness coefficients, is then introduced as a means of both material characterization and defect analysis in composite materials. A brief discussion on a test protocol and an interpretation of the elements in the feature matrix from an NDE point of view is also presented. The conclusions of a previous theoretical investigation of wave propagation in anisotropic media are considered from an experimental point of view by way of the bulk wave technique. A result of fundamental value is that the actual propagation of quasilongitudinal waves, generated by a standard broad band pulsed transducer, is indeed well matched with the theoretical approximation obtained earlier. This approximation was based on the generalized retarded potential principle with variable energy velocity of the quasilongitudinal mode in an anisotropic medium as the substitute for the constant longitudinal velocity used in the retarded potential scheme for an isotropic medium.

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Han, So Ra, Chun Young Park, Young Geun Eom e Jun Jae Lee. "Studies about the Influence Factors on Ultrasonic Velocity of Domestic Red Pine". Key Engineering Materials 321-323 (outubro de 2006): 1177–81. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.1177.

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This research was carried out to grasp the factors influencing to the ultrasonic velocity to improve the efficiency of the ultrasonic wave test using as the method of NDE of wood. However, it was difficult to detect the defect of wood accurately, because ultrasonic velocity is influenced by various factors. So, some effect factors, which were not concerned with decay, were confirmed at first. Therefore, in this research, we tried to find the factors which affect on the natural characters and the ultrasonic velocity at decayed wood, additionally, we tried an anatomic experiment and analyze. As a result of research, the velocity at radial direction was faster than that at tangential direction and the ultrasonic velocity at immature wood and reaction wood was slower than that at normal wood. And the ultrasonic velocity was more the slower at bigger the length of decay and reduction of weight.

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Im, Kwang-Hee, Yun-Taek Yeom, Hyung-Ho Lee, Sun-Kyu Kim, Young-Tae Cho, Yong-Deuck Woo, Peng Zhang, Gue-Lin Zhang e Sung-Duk Kwon. "NDE Characterization of Surface Defects on Piston Rods in Shock Absorbers Using Rayleigh Waves". Applied Sciences 12, n.º 12 (12 de junho de 2022): 5986. http://dx.doi.org/10.3390/app12125986.

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In general, shock absorbers are components that can absorb shock and vibration energy caused by wheel behavior, and they provide handling stability. As a piston rod is an important component in shock absorbers, multiple processes are performed in order to guarantee its quality during manufacturing. Micro-defects can be generated on the surfaces of piston rods after processing. Because these defects can degrade the function of shock absorbers, proper non-destructive techniques are necessary to monitor the surfaces of piston rods. In this study, micro-defects were artificially machined on the surfaces of piston rods. In particular, a Rayleigh wave technique was adopted to detect defects on the surfaces of the piston rods, and Rayleigh wave behaviors were analyzed to establish beam profiles. In terms of the experimental method, defects were fabricated on the piston rods, and the optimal Rayleigh angle was determined using the pulse-echo method with ultrasonic transducers in a water tank. This was performed to evaluate the characteristics of the Rayleigh waves. In testing, regardless of the types of micro-defects on the surfaces of the pistons, it was found that the optimal inspection condition could be in the range of 5–10 mm, where ultrasonic signals were received with a high resolution. Moreover, the behaviors of the transmitted Rayleigh waves were simulated, and reflection, transmission, and scattering occurred due to defects at the interface between the water and steel. Thus, the propagation of Rayleigh waves and the optimal test conditions were implemented through FEM simulation to generate effective Rayleigh waves.

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Barreto, Mayara Leilane de Jesus, Adriano Henrique do Nascimento Rangel, Maria Helena Constantino Spyrides, Gelson Santos Difante e Dorgival Morais de Lima Júnior. "Physicochemical and sensory characteristics of milk from cows in different lactation stages and calving orders". Semina: Ciências Agrárias 37, n.º 4 (30 de agosto de 2016): 1963. http://dx.doi.org/10.5433/1679-0359.2016v37n4p1963.

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Knowledge of the variation in milk composition is essential for determining milk quality, which is defined by several organoleptic properties. This study evaluated the effect of lactation stage and calving order on the physicochemical composition and sensory characteristics of milk from primiparous and multiparous lactating dairy cows. Milk samples were collected monthly from December 2011 to May 2012. Data were analyzed using ANOVA followed by Tukey’s test (p < 0.05). Milk production (PROD), somatic cell count (SCC), and milk urea nitrogen (MUN) were significantly higher in multiparous cows, whereas the casein to total protein ratio (C/TP) was significantly higher in primiparous cows. All milk components except for non-fat dry solids (NDE) were significantly affected by lactation stage. Body condition score (BCS) was not affected by calving order or lactation stage. Color was the only sensory attribute affected by calving order. In conclusion, the physicochemical properties and sensory attributes of milk were affected by calving order and lactation stage.

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Hao, Jun Cai, Jin Wang e Yue Min Yu. "Non-Destructive Evaluation of Composite Laminates by Using Fiber Optic AE Sensor". Applied Mechanics and Materials 204-208 (outubro de 2012): 3965–69. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.3965.

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Considering the damage that composite material under loading may occur, acoustic emission (AE) technique is adopted to perform non-destructive evaluation (NDE). In order to obtain the acoustic emission emitted from the composite material, a novel fiber optic AE sensor which is based on single mode fiber optical fused-tapered coupler design is developed. Futhermore, its fabrication process was described and performance was studied. Results of a pencil break test on the composite laminate show that the fiber optic AE sensor have better frequency response than the commercial piezoelectric sensor. During a tension experiment of a carbon fiber composite specimen , the fiber optic sensor which was mounted on it detected the enormous acoustic emission signals. To analyze their characteristic parameter, such as amplitude, duration, can identify the type of failure to composite materials, including Matrix cracking , Interface stripping, fiber breakage. Experimental results would offer the reference to damage identification to complicate composite structures.

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Miwa, Takashi. "Non-Destructive and Quantitative Evaluation of Rebar Corrosion by a Vibro-Doppler Radar Method". Sensors 21, n.º 7 (5 de abril de 2021): 2546. http://dx.doi.org/10.3390/s21072546.

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It is well known that evaluation of rebar corrosion is important for the maintenance of reinforced concrete structures, but, it is difficult to simply, quickly and quantitatively evaluate the amount of corrosion of rebars embedded in concrete by conventional non-destructive evaluation (NDE) methods such as electrical, electromagnetic and mechanical method. This paper proposes a vibro-Doppler radar (VDR) measurement method to quantitatively evaluate rebar corrosion by measuring the vibration ability of the rebar forcibly vibrated in concrete by an excitation coil. It is experimentally demonstrated in RC test pieces that the rebar vibration displacement obtained by developed VDR method is valid and is less affected by the moisture in the concrete. In addition, simultaneous monitoring of the rebar vibration displacement of the test pieces is performed through an electrolytic corrosion test and the measured vibration displacement is compared to the rebar corrosion loss evaluated. As the results, it is cleared that the rebar vibration displacement starts to increase from slightly before the occurrences of corrosion crack on the concrete surface as the corrosion loss increases. It is also shown that the rebar vibration displacement becomes 4 times higher than that in initial condition at the rebar corrosion loss of 250 mg/cm2. This implies that the VDR has potential to nondestructively and quantitatively evaluate rebar corrosion in concrete.

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ANDO, K., K. TAKAHASHI, K. FURUSAWA e W. NAKAO. "SMS-18: Crack-healing+Proof Test+In-Situ-Crack-Healing : A New Methodology to Guarantee the Structural Integrity of Ceramic Components(SMS-III: SMART MATERIALS AND STRUCTURES, NDE)". Proceedings of the JSME Materials and Processing Conference (M&P) 2005 (2005): 35. http://dx.doi.org/10.1299/jsmeintmp.2005.35_3.

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Kasarda, M., D. D. Quinn, T. Bash, G. Mani, Daniel J. Inman, R. G. Kirk e Jerzy T. Sawicki. "Magnetic Bearings for Non-Destructive Health Monitoring of Rotating Machinery Supported in Conventional Bearings". Key Engineering Materials 293-294 (setembro de 2005): 383–90. http://dx.doi.org/10.4028/www.scientific.net/kem.293-294.383.

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This paper describes initial results from a project expanding the field of rotor health monitoring by using Active Magnetic Bearings (AMBs) as actuators for applying a variety of known force inputs to a spinning rotor in order to monitor and evaluate response signals resulting from these inputs on-line. Similar to modal analysis and other nondestructive evaluation (NDE) techniques which apply input signals to static structures in order to monitor responses; this approach allows for the measurement of both input and output response in a rotating system for evaluation. However, unlike these techniques, the new procedure allows for multiple forms of force input signals to be applied to a rotating structure. This technique is being developed for use on rotating equipment supported in conventional bearings where an AMB actuator is added to a system for improved health monitoring. This paper presents initial results from this project including a demonstration of the system identification capability of the procedure during the commissioning of a test rig, and a summary of a technique developed for identifying breathing-cracks in rotors using the new technique.

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Dai, L. S., Q. S. Feng, X. Q. Xiang, J. Sutherland, T. Wang, D. P. Wang e Z. J. Wang. "Application of USCCD on Girth Weld Defect Detection of Oil Pipelines". Applied Sciences 10, n.º 8 (15 de abril de 2020): 2736. http://dx.doi.org/10.3390/app10082736.

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Globally, more and more attention has been paid to the integrity of Girth Welds (GW) of oil and gas pipelines due to their failures with high consequences. A primary concern is that defects originate during field construction but over time may be subject to external loads due to earth movement. GW defects in newly built pipelines are also assumed to exist but would be much smaller in size, and more difficult to detect, which motivated the investigation into minimum defect detection capabilities of the inspection technologies. This study presents the evaluation results of UltraScan™ Circumferential Crack-Like Detection (USCCD) technology for oil pipeline GW inspection, based upon the pull test and in field data from Inline Inspection (ILI) of pipeline by PetroChina Pipeline Company (PPC) using GE PII (General Electric Company, Pipeline Integrity Inspection) 32” UltraScan™ CCD Tool. The performance of USCCD is given according to the ILI data, pull test results and dig NDE (Non-Destructive Examination). It can be concluded that crack-like defects with clear edges can be detected during ultrasonic propagation; however, the irregular shape of weld makes the inspection more difficult. It is still a challenge to identify the type of defects, and depth sizing can only be classified not quantified, which would require more excavations. However, this technology is feasible for the alternative technology of GW defect inspection.

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