Academic literature on the topic 'Electric capacitance non-destructive control'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Electric capacitance non-destructive control.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Electric capacitance non-destructive control"
1
Mustafa, Ehtasham, Ramy S. A. Afia, Oumaima Nouini, and Zoltán Ádám Tamus. "Implementation of Non-Destructive Electrical Condition Monitoring Techniques on Low-Voltage Nuclear Cables: I. Irradiation Aging of EPR/CSPE Cables." Energies 14, no. 16 (August 20, 2021): 5139. http://dx.doi.org/10.3390/en14165139.
Full textAbstract:
In a nuclear power plant environment, low-voltage cables experience different stresses during their service life which challenge their integrity. A non-destructive and reliable condition monitoring technique is desired to determine the state of these low-voltage cables during service and for the life extension of nuclear power plants. Hence, in this research work, an EPR/CSPE-based low-voltage cable was exposed to γ-rays for five different absorbed doses. The overall behavior of the cable under stress was characterized by frequency and time domain electrical measurements (capacitance, tan δ, and Extended Voltage Response) and a mechanical measurement (elongation at break). Significant variations in the electrical parameters were observed, as was a decline in the elongation at break values. A strong correlation between the measurement methods was observed, showing the ability of the electrical methods to be adopted as a non-destructive condition monitoring technique.
2
Lee, Gayoung, Jaehun Jeong, Yeeun Kim, Dahyun Kang, Sooyong Shin, Jongwon Lee, Sung Ho Jeon, and Moongyu Jang. "Growth and Drug Interaction Monitoring of NIH 3T3 Cells by Image Analysis and Capacitive Biosensor." Micromachines 12, no. 10 (October 14, 2021): 1248. http://dx.doi.org/10.3390/mi12101248.
Full textAbstract:
Capacitive biosensors are manufactured on glass slides using the semiconductor process to monitor cell growth and cell–drug interactions in real time. Capacitance signals are continuously monitored for each 10 min interval during a 48 h period, with the variations of frequency from 1 kHz to 1 MHz. The capacitance values showed a gradual increase with the increase in NIH 3T3 cell numbers. After 48 h of growth, 6.67 μg/mL puromycin is injected for the monitoring of the cell–drug interaction. The capacitance values rapidly increased during a period of about 10 h, reflecting the rapid increase in the cell numbers. In this study, we monitored the state of cells and the cell–drug interactions using the developed capacitive biosensor. Additionally, we monitored the state of cell behavior using a JuLiTM Br&FL microscope. The monitoring of cell state by means of a capacitive biosensor is more sensitive than confluence measuring using a JuLiTM Br&FL microscope image. The developed capacitive biosensor could be applied in a wide range of bio-medical areas; for example, non-destructive real-time cell growth and cell–drug interaction monitoring.
3
Vilitis, O., M. Rutkis, J. Busenberg, and D. Merkulov. "Determination of Contact Potential Difference by the Kelvin Probe (Part I) I. Basic Principles of Measurements." Latvian Journal of Physics and Technical Sciences 53, no. 2 (April 1, 2016): 48–57. http://dx.doi.org/10.1515/lpts-2016-0013.
Full textAbstract:
Abstract Determination of electric potential difference using the Kelvin probe, i.e. vibrating capacitor technique, is one of the most sensitive measuring procedures in surface physics. Periodic modulation of distance between electrodes leads to changes in capacitance, thereby causing current to flow through the external circuit. The procedure of contactless, non-destructive determination of contact potential difference between an electrically conductive vibrating reference electrode and an electrically conductive sample is based on precise control measurement of Kelvin current flowing through a capacitor. The present research is devoted to creation of a new low-cost miniaturised measurement system to determine potential difference in real time and at high measurement resolution. Furthermore, using the electrode of a reference probe, the Kelvin method leads to both the indirect measurement of an electronic work function, or a contact potential of sample, and of a surface potential for insulator type samples. In the article, the first part of the research, i.e., the basic principles and prerequisites for establishment of such a measurement system are considered.
4
Zhang, Hao, Shupeng Chen, Hongxia Liu, Shulong Wang, Dong Wang, Xiaoyang Fan, Chen Chong, Chenyu Yin, and Tianzhi Gao. "Polarization Gradient Effect of Negative Capacitance LTFET." Micromachines 13, no. 3 (February 22, 2022): 344. http://dx.doi.org/10.3390/mi13030344.
Full textAbstract:
In this paper, an L-shaped tunneling field effect transistor (LTFET) with ferroelectric gate oxide layer (Si: HfO2) is proposed. The electric characteristic of NC-LTFET is analyzed using Synopsys Sentaurus TCAD. Compared with the conventional LTFET, a steeper subthreshold swing (SS = 18.4 mV/dec) of NC-LTFET is obtained by the mechanism of line tunneling at low gate voltage instead of diagonal tunneling, which is caused by the non-uniform voltage across the gate oxide layer. In addition, we report the polarization gradient effect in a negative capacitance TFET for the first time. It is noted that the polarization gradient effect should not be ignored in TFET. When the polarization gradient parameter g grows larger, the dominant tunneling mechanism that affects the SS is the diagonal tunneling. The on-state current (Ion) and SS of NC-LTFET become worse.
5
Luo, Bing, Tingting Wang, Fuzeng Zhang, Yibin Lin, Chaozhi Zheng, and She Chen. "Interdigital Capacitive Sensor for Cable Insulation Defect Detection: Three-Dimensional Modeling, Design, and Experimental Test." Journal of Sensors 2021 (March 31, 2021): 1–10. http://dx.doi.org/10.1155/2021/8859742.
Full textAbstract:
Due to excellent electrical and mechanical properties, cross-linked polyethylene (XLPE) cables are widely used in power systems. Poor manufacturing techniques in the production and installation of cable joints will cause insulation defects. The interdigital capacitive (IDC) sensor has advantages of simple structure and non-contact with the center conductor and shows great potential for online monitoring on XLPE cables. This paper focuses on the 3D modeling of a fully covered IDC sensor for cable insulation detection. Firstly, a 3D finite element model of the sensor is built, and the electric field distributions are compared with those of the partially covered sensor. For the sensor with more electrode pairs, the sensitivity increases with the sensor length and tends to saturate at the length of 5 cm, while the sensitivity remains constant for the sensor with fewer electrode pairs. Then, the differences between 3D and 2D results are discussed and the sensor parameters are optimized to reduce the influence of the fringe capacitance. The simulation results indicate that air gaps between the sensor and XLPE cable are the main reason of the difference between simulation and experiment. When the electrode width is equal to the gap width, the effects of both the fringing electric field and air gaps are relatively small. Finally, several types of sensors are made and used to detect the cable joint with and without the stress cone dislocation under different excitation voltage frequency. The results show that the measured capacitance decreases with frequency and the capacitance of the cable joint with the defects is smaller than that of the normal cable joint.
6
Dionne, Eric R., Fadwa Ben Amara, and Antonella Badia. "An electrochemical immittance analysis of the dielectric properties of self-assembled monolayers." Canadian Journal of Chemistry 98, no. 9 (September 2020): 471–79. http://dx.doi.org/10.1139/cjc-2020-0005.
Full textAbstract:
The ability of organic self-assembled monolayers (SAMs) to act as insulating barriers to electron transfer, ion transport, or molecular diffusion is critical to their application in a variety of technologies. The use of appropriate analytical tools to characterize the dielectric properties of these molecular thin films is important for the control of structural defects and establishing structure–property relations. In this context, we analyze the ionic permeability and dielectric response of SAMs formed from a homologous series of n-alkanethiolates (CH3(CH2)nS, where n = 9, 11, 13, 15, 17, and 19) on gold using the immittance quantities of the complex impedance, capacitance, and permittivity available from the same electrochemical impedance spectroscopy (EIS) measurement. The most sensitive parameters and frequency range for characterizing the capacitive behavior and assessing the ion-blocking quality of the SAMs under non-Faradaic conditions are identified. We also investigate the effect of chain length on the interfacial capacitance and dielectric constant of ionic insulating SAMs. The advantages of the capacitance quantity and related permittivity data over traditional impedance representations and equivalent electric circuit modeling are discussed.
7
Jagtap, Sarika Madhukar, and Vitthal Janardan Gond. "Modeling of 7 Nano Meter Fin Field Effect Transistor for Evaluation of Fringe & Oxide Capacitance." Trends in Sciences 19, no. 2 (January 15, 2022): 2051. http://dx.doi.org/10.48048/tis.2022.2051.
Full textAbstract:
Fin-FET are insusceptible to short channel effects punch through, threshold voltage, leakage current but their concerts at high frequencies are conceded due to durable fringing field between gate and source with drain area. Because of high-technology progression, the gate construction of MOSFET has been upgraded from planar to nonplanar with an enrichment in the number of monitoring gates multiple gates on 3 sides. In this paper we mention Fin-FET assembly for high frequency applications.
MOS-FET plays very energetic role but scaling of device affected on performance parameters like speed and power. Fin-FET is non planar novel device to solve the short channel effects which occurs due to scaling. Non-planar structure of Fin-FET parasitic capacitances like gate oxide overlap and fringe capacitance makes adverse effect like lower switching speed of device, making result on delay ion and ioff of device. In this paper we planned Fin-FET design procedure to measure oxide and fringe capacitance with low k dielectric spacer thickness and increase ion to recover device driving ability. Effect on threshold voltage having observed with low k spacer at least count of 0.051 V. By using 4.65 eV metal gate work function with front, top and back gate we control leakage current and threshold voltage. Seven nano meter gate length Fin-FET is design We measured oxide capacitance of 0.464 F for 19.28 GHz and fringe capacitance (69.66 nf) for 4.88 GHz frequency by designing the Fin-FET with high-K SOI MOSFETs which support 11.4 nA leakage current to improve the speed of the processor.
In this research work, design topologies of Single Finger Fin Filed Effect Transistors are discussed and evaluate the probable result of fringe and parasitic capacitance from fringing area on the device. By using geometry of device like fin width, height, thickness and multiple fingers we measure the fringe capacitance and oxide capacitance of designed Fin-FET.
HIGHLIGHTS
In this Paper, we focus on fundamentals of novel device Fin-FET its working construction & design based on geometry parameter & capacitance measurement by designing model of 7 nm gate length
In this work, we focus on how Fin-FET helps to reduce short channel effect by possessions of geometry parameters like gate length and Fin thickness & progress the performance of the nanoscale device
From the simulation results we observe lowering of drain induced barrier lowering, subthreshold slope and leakage current, whereas threshold voltages rise
From the observation, SCE has been attributed to the distribution of the junction electric fields into the channel region, producing lower DIBL which decreases VTH
GRAPHICAL ABSTRACT
8
Tsubota, Toshiki, Shion Tsuchiya, Tatsuya Kusumoto, and Dimitrios Kalderis. "Assessment of Biochar Produced by Flame-Curtain Pyrolysis as a Precursor for the Development of an Efficient Electric Double-Layer Capacitor." Energies 14, no. 22 (November 16, 2021): 7671. http://dx.doi.org/10.3390/en14227671.
Full textAbstract:
Pine tree biochar produced by flame-curtain pyrolysis, an inexpensive and simple pyrolysis methodology, was used as the starting material for KOH-activated carbon. Flame-curtain pyrolysis is a simple, low-technology methodology that can be performed by non-specialized personnel. The elemental analysis of the biochars highlighted the high reproducibility of the process. The N2 adsorption isotherms indicated that KOH activation was effective for the preparation of high-surface-area activated carbons from the biochar. The BET specific surface area increased with the quantity of KOH added in the activation process, achieving a maximum value of 3014 m2 g−1 at 85.7 wt.% of KOH addition. The adsorption isotherms of all samples were IUPAC type I, establishing their microporous nature. Results from the Mikhail–Brunauer (MP) method and αs plot indicated that the pore size distribution became wider and the pore volume increased as the KOH content increased. The measured capacitance values followed the same dependence on KOH content. The maximum capacitance value at 1 mV s−1 was determined as 200.6 F g−1 for the sample prepared at 75 wt.% of KOH addition. Therefore, pine tree biochar prepared by simple pyrolysis equipment is a suitable precursor for the development of an electric double-layer capacitor.
9
Rasheed, Mohammed Sarvar, Mustufa H. Abidi, Abdulaziz M. El-Tamimi, and A. M. Al-Ahmari. "Investigation of Micro-EDM Input Parameters on Various Outputs in Machining Ni-Ti Shape Memory Alloy Using Full Factorial Design." Advanced Materials Research 816-817 (September 2013): 173–79. http://dx.doi.org/10.4028/www.scientific.net/amr.816-817.173.
Full textAbstract:
Micro Electric Discharge Machining (μ-EDM) is a non-traditional machining process which is used for drilling micro holes in a high strength-to-weight ratio advanced engineering materials like shape memory alloys that have many applications in the field of aerospace and medical sciences. However, in order to achieve the desired output responses the process control parameters of the machine have to be set at an optimal setting. In this research work, an investigation has been made to study the influence of the input parameters (such as capacitance, discharge voltage and electrode material) on the micro-EDM process output responses (such as MRR, TWR, Ra and circularity of the micro-holes) while drilling the micro-holes on Ni-Ti shape memory alloy. The full factorial design based study resulted in a set of recommended values for input variables to obtain the desired output. Mathematical predictive models have also been developed, which predict good values for the output responses.
10
Zhu, Xixiang, Liping Peng, Jinpeng Li, Haomiao Yu, and Yulin Xie. "Formation of a Fast Charge Transfer Channel in Quasi-2D Perovskite Solar Cells through External Electric Field Modulation." Energies 14, no. 21 (November 5, 2021): 7402. http://dx.doi.org/10.3390/en14217402.
Full textAbstract:
Quasi-2D perovskites solar cells exhibit excellent environmental stability, but relatively low photovoltaic properties, compared with 3D perovskites solar cells. However, charge transport and extraction in quasi-2D perovskite solar cells are still limited by the inevitable quantum well effect, resulting in low power conversion efficiency (PCE). To date, most efforts concentrate on crystal orientation and favorable alignment during materials and films processing. In this paper, we demonstrated that the quasi-2D perovskite [(BA)2(MA)3Pb4I13 (n = 4)] solar cells show an optimized device performance through forming a fast charge transfer channel among 2D quantum wells through external electric field modulation, with appropriate modulation bias and time after the device has been fabricated. Essentially, ions will move directionally due to local polarization in quasi-2D perovskite solar cells under the action of electric field modulation. More importantly, the mobile ions function as a dopant to de-passivate the defects when releasing at grain boundaries, while decreasing built-in potential by applying forward modulation bias with proper modulation time. The capacitance-voltage characteristics indicate that electric field modulation can decrease the charge accumulation and improve the charge collection in quasi-2D perovskite solar cells. Photoluminescence (PL) studies confirm that the non-radiative recombination is reduced by electric field modulation, leading to enhanced charge transfer. Our work indicates that external electric field modulation is an effective method to form a fast charge transfer channel among 2D quantum wells, leading to enhanced charge transfer and charge collection through local polarization toward developing high–performance quasi-2D perovskite devices.
Dissertations / Theses on the topic "Electric capacitance non-destructive control"
1
Івіцька, Дар’я Костянтинівна. "Вдосконалення електроємнісного методу контролю для дефектоскопії матеріалів." Doctoral thesis, Київ, 2019. https://ela.kpi.ua/handle/123456789/26528.
Full textAbstract:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.11.13 – Прилади і методи контролю та визначення складу речовин. – Національний технічний університет України «Київський політехнічний інститут імені Ігоря Сікорського», МОН України, Київ, 2019.
У роботі здійснено математичне моделювання, яке дозволило визначити раціональні параметри та режими роботи сенсору для забезпечення максимальної чутливості схеми. Досліджено параметри процесу контролю та межі застосування методу. Здійснено моделювання контролю дефектів різних типів.
Здійснено моделювання розподілу чутливості ємнісного сенсора, що дозволило порівняти сенсори різної геометричної форми та визначити оптимальні конструктивні параметри. Запропоновано конструкцію сенсора, яка має найвищу чутливість та глибину проникнення. Здійснено моделювання процесу контролю матеріалів зі змінними провідними властивостями, що підтвердило можливість застосування методу для такого класу матеріалів.
Розроблено спосіб підвищення завадостійкості та швидкодії методу. Проведено експериментальні дослідження, які підтвердили працездатність електроємнісного методу для контролю дефектів. Шляхом математичного моделювання проаналізовано вплив різних чинників на випадкову похибку вимірювання.
2
Новик, К. С. "Пристрій експрес-контролю концентрації аргону в енергозберігаючих склопакетах." Thesis, Чернігів, 2020. http://ir.stu.cn.ua/123456789/21477.
Full textAbstract:
Новик, К. С. Пристрій експрес-контролю концентрації аргону в енергозберігаючих склопакетах : дипломна робота : 152 Метрологія та інформаційно-вимірювальна техніка / К. С. Новик ; керівник роботи Наумчик П. І. ; Національний університет «Чернігівська політехніка», кафедра інформаційно-вимірювальних технологій, метрології та фізики. – Чернігів, 2020. – 46 с.Об'єкт – пристрій експрес-контролю концентрації аргону в енергозберігаючих склопакетах. Мета – розробка пристрою експрес-контролю концентрації аргону в енергозберігаючих склопакетах та дослідження залежності електричної міцності суміші аргону і повітря від концентрації аргону. Установка для проведення експериментального дослідження включала в себе вакуумну тарілку, вакуумний насос, електрофорну машину, розрядник, вольтметр, балон з аргоном. В ході дослідження за допомогою штангенциркуля встановлювали, на якій найменшій відстані відбувається іскровий електричний розряд між розрядними кулями електрофорної машини, а також виміряли напругу розряду. Слід зазначити, що іскровий розряд між кулями електрофорної машини відбувався на значно меншій відстані, ніж між кулями розрядника, який розміщувався під ковпаком вакуумної тарілки з аргоном. Загалом було проведено 6 серій експерименту для різних концентрацій. За отриманими даними побудували графік залежності електричної міцності від концентрації аргону в газо-повітряній суміші, який можна використати для калібрування пристрою оцінювання якості склопакетів. Розібрали будову та принцип дії пристрою експрес-контролю концентрації аргону в енергозберігаючих склопакетах. Визначили, що пристрій повинен містити такі частини: гальванічний елемент, кнопка запалення іскри, високовольтний генератор, індикатор струму, контактні електроди, корпус, клеми електричного розрядника, електричний розрядник та внутрішня камера склопакета.
Оbject – device for express control of argon concentration in energy-saving double-glazed windows. Purpose – development of a device for express control of argon concentration in energy-saving double-glazed windows and study of the dependence of the electrical strength of a mixture of argon and air on the argon concentration. The installation for the experimental study included a vacuum plate, a vacuum pump, an electrophoretic machine, an arrester, a voltmeter, and an argon filled cylinder. In the course of the study, a caliper was used to determine the smallest distance between the spark electric discharge between the discharge balls of the electrophoretic machine, and the discharge voltage was measured. It should be noted that the spark discharge between the balls of the electrophoretic machine occurred at a much shorter distance than between the balls of the arrester, which was placed under the cap of a vacuum plate with argon. In total, 6 series of experiments were performed for different concentrations. According to the obtained data, a graph of the dependence of electrical strength on the concentration of argon in the gas-air mixture, which can be used to calibrate the device for assessing the quality of double-glazed windows. The structure and principle of operation of the device of express control of argon concentration in energy-saving double-glazed windows were disassembled. It was determined that the device should contain the following parts: galvanic cell, spark ignition button, high-voltage generator, current indicator, contact electrodes, housing, terminals of the electrical arrester, electrical arrester and internal chamber of double-glazed windows.
Book chapters on the topic "Electric capacitance non-destructive control"
1
Krishnan, Kannan M. "Scanning Probe Microscopy." In Principles of Materials Characterization and Metrology, 745–802. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198830252.003.0011.
Full textAbstract:
Scanning probe microscopy (SPM) scans a fine tip close to a surface and measures the tunneling current (STM) or force (SFM), based on many possible tip-surface interactions. STM provides atomic resolution imaging, or the local electronic structure (spectroscopy) as a function of bias voltage, and is also used to manipulate adsorbed atoms on a clean surface. STM operates in two modes— constant current or height—and requires a conducting specimen. SFM uses a cantilever (force sensor) to measure short range (< 1 nm) chemical, and a variety of long-range (< 100 nm) forces, depending on the tip and the specimen; a conducting specimen is not required. In static mode, the tip height is controlled to maintain a constant force, and measure surface topography. In dynamic mode, changes in the vibrational properties of the cantilever are measured using frequency, amplitude, or phase modulation as feedback to control the tip-surface distance and form the image. Dynamic imaging includes contact and non-contact modes, but intermittent contact or tapping mode is common. SPMs measure properties (optical, acoustic, conductance, electrochemical, capacitance, thermal, magnetic, etc.) using appropriate tips, and find applications in the physical and life sciences. They are also used for nanoscale lithography.
Conference papers on the topic "Electric capacitance non-destructive control"
1
He Yinsheng and Shang Liqun. "Study of fault line selection in the non-solidly earthed network based on the method of increasing the grounding capacitance of the line." In 2011 International Conference on Electric Information and Control Engineering (ICEICE). IEEE, 2011. http://dx.doi.org/10.1109/iceice.2011.5777768.
Full text
2
Kim, Jun-Sik, K. W. Wang, and Edward C. Smith. "High Authority Piezoelectric Actuation System Synthesis Through Mechanical Resonance and Electrical Tailoring." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-43994.
Full textAbstract:
In this research, a new approach is proposed to enhance the effectiveness of piezoelectric actuators without the trade off between force and stroke. Through mechanical tailoring, the resonant frequencies of the actuation system (includes the piezoelectric actuator and the related mechanical and the electrical elements for actuation) can be tuned to the required actuation frequencies. This obvious will increase the authority (both stroke and force) of the actuation system. However, resonant actuation system could be hard to control and non-robust, due to its narrow operating bandwidth. This issue can be resolved through electric circuit tailoring. With the aid of a network of inductance, resistance, and negative capacitance, the actuation resonant peak can be significantly broadened and flattened. In this case, one can achieve a high authority actuation system without the negative effects of resonant problems. The electrical networks can also a achieve a fail-safe system due to its passive shunting characteristic. The proposed concept is evaluated using a PZT tube actuator for trailing edge flap control of rotocraft blades. Promising results are demonstrated, showing that the treatment can indeed create a high authority and robust actuation system that satisfies the performance requirements of the example application. Also, the proposed concept is verified by experiments using an equivalent circuit model with synthetic inductor and negative impedance converter of capacitance.
3
Hong, Liu, Yu Hua, Niu Shu, and Guo Ruizhou. "Measurement of Capacitance Current of Neutral Point Non - grounding System." In 2018 IEEE 3rd Advanced Information Technology, Electronic and Automation Control Conference (IAEAC). IEEE, 2018. http://dx.doi.org/10.1109/iaeac.2018.8577664.
Full text
4
Chigullapalli, Aarti, and Jason V. Clark. "Towards Measuring Young’s Modulus by Electronic Probing." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-89155.
Full textAbstract:
We propose an accurate and precise method for measuring the Young’s modulus of MEMS with comb drives by electronic probing of capacitance. The electronic measurement can be performed off-chip for quality control or on-chip after packaging for self-calibration. Young’s modulus is an important material property that affects the static or dynamic performance of MEMS. Electrically-probed measurements of Young’s modulus may also be useful for industrial scale automation. Conventional methods for measuring Young’s modulus include analyzing stress-strain curves, which is typically destructive, or include analyzing a large array of test structures of varying dimensions, which requires a large amount of chip real estate. Our method measures Young’s modulus by uniquely eliminating unknowns and extracting the fabricated geometry, displacement, comb drive force, and stiffness. Since Young’s modulus is related to geometry and stiffness that we find using electronic measurands, we are able to express Young’s modulus as a function of electronic measurands. We verify our method by using it to predict the Young’s modulus of a computer model. We treat the computer model as we would treat a true experiment by depending only on its electronic measurands. We find good agreement in predicting the exactly known Young’s modulus in a computer model within 0.1%.
5
Lu, Xiaoyu, and Xiang Zhou. "Calculation of Capacitance Matrix of Non-uniform Multi-conductor Transmission Lines based on S-parameters." In 2021 IEEE 5th Information Technology,Networking,Electronic and Automation Control Conference (ITNEC). IEEE, 2021. http://dx.doi.org/10.1109/itnec52019.2021.9586871.
Full text
6
Tandon, G. P., and R. Y. Kim. "Non-Destructive Evaluation of Damage Around Circular Holes in Bolted Composite Laminates." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14987.
Full textAbstract:
One of the more formidable problems in composite research is the study of delamination and other failure modes in the vicinity of a circular hole in a laminate, e.g., a circular cut-out in a structure. In this problem, the singularity varies around the periphery of the hole as well as through the thickness of the laminate. Under tensile loading, the early failure modes in this problem consist of transverse cracks in various layers, so that delamination occurs only after other damage is precipitated, followed by fiber breakage leading to failure. A literature review of past work clearly shows that mechanical testing with simultaneous AE monitoring is a fruitful technique to study damage accumulation in composite systems. The acoustic-ultrasonic (AU) testing combines the high sensitivity of ultrasonics to internal damage and the method of acoustic emission technique to characterize elastic waves. As damage accumulates in the specimen along the wave path, the net internal damping increases and changes the wave parameters such as velocity, peak amplitude, duration, etc. accordingly. Additionally, a range of experimental results over the last decade has further shown that the mechanical deformation and electric resistance of carbon fiber reinforced polymers are coupled, so that the material is inherently a sensor of its own damage state. The monitoring of electric resistance and capacitance changes, linked to the modifications of the conduction paths in the composite, allows the detection of damage growth. It seems logical that a natural extension of these different approaches is the determination of damage mode, e.g., fiber breakage, matrix cracking or delamination, and damage size and position, based on combined measurements from these techniques. These multiple techniques will serve a two-fold purpose, namely, enable comparison as well as complement each other in case of incomplete damage mapping from one set of sensors For this study, we will consider carbon fiber-reinforced toughened bismaleimide, (IM7/5250-4) quasi-isotropic laminate coupons 12" long, 4" wide with hole at the center under tension. Figure 1 shows the damage which occurs around a 0.75" hole in a [45/0/-45/90]s graphite epoxy laminate obtained by radiography after unloading the test specimen from an applied stress of 50 Ksi. The failure stress for this laminate was 56.4 Ksi. Damage in the form of ply cracks in the 90, 45, and -45 plies and delamination around hole edges is clearly evident. The radiograph taken after unloading from a 50 Ksi stress level clearly shows the location and extent of damage, but contains no specific information about the sequence and the timing of damage events. Figure 2 shows stress-strain curves obtained from strain gages mounted at various distances away from the hole edge along with the far-field value. The stress-strain curves provide useful information regarding the initiation as well as the growth of the damage, as evidenced by jump in strain levels and onset of nonlinearity. Damage initiation is first picked up by the strain gage which is mounted closest to the hole edge at a stress level of 21 Ksi. Subsequently, other strain gages begin to sense damage growth as the applied stress level increases. The strain gage data provides useful information regarding initiation, growth and severity of damage, but it is difficult to assign specific damage modes and their location to the measurements. This example clearly demonstrates the needs, with the associated benefits, of the multiple sensor approach. In this work, three different hole sizes (0.25", 0.5" and 0.75") will be investigated. In addition to inherent resistivity measurements, we will also make strain measurements using gages coupled with simultaneous monitoring of AE events and attenuation of elastic waves using piezoelectric transducers and acceleration sensors. This example problem will enable us to examine the combined effects of cut-outs, matrix cracking, delamination and fiber breakage on the ability of various NDE techniques to assess damage. Integrating several nondestructive evaluation (NDE) techniques could provide a solution for real-time health monitoring.
7
Agazar, Mohamed, Denis Perrillat, Hanane Saadeddine, Christophe Robert, Laurence Casteignau, and Dominique Fortune. "Study of non-invasive instruments for the measurement of pulsed X-ray high voltage tube." In 19th International Congress of Metrology (CIM2019), edited by Sandrine Gazal. Les Ulis, France: EDP Sciences, 2019. http://dx.doi.org/10.1051/metrology/201902002.
Full textAbstract:
Non-invasive instruments (kVp meters) are widely used in radiology with diagnostic and guidance systems. Placed in the x-ray beam, they combine detectors and filters, to determine X-ray tube voltage and exposure time, which are the most important quantities in radiology and diagnostic quality control. Calibration of these instruments were limited by reference bench capabilities. General Electric Medical System France and LNE (The national metrology institute in France) have developed a reference bench for the characterization of kVp meters. The set up includes a fast high voltage generator associated with its internal measuring systems and an X-ray tube. The measurements are compared with an invasive reference standard. The set-up is installed in a Faraday cage, precautions have been taken in order to carry out accurate measurements and special adaptations have been made to avoid stray capacitances, which affect the dynamic performance of the generator. Results have shown a good agreement with the internal measuring system of the generator but the kVp meters have shown both good and bad results depending the exposure time, the current and the positioning.
8
Tandon, G. P., and R. Y. Kim. "Multi-Sensor Approach to Non-Destructive Evaluation of Damage Around Circular Holes in Composite Laminates." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79275.
Full textAbstract:
One of the more formidable problems in composite research is the study of delamination and other failure modes in the vicinity of a circular hole in a laminate, e.g., a circular cut-out in a structure. In this problem, the singularity varies around the periphery of the hole as well as through the thickness of the laminate. Under tensile loading, the early failure modes in this problem consist of transverse cracks in various layers, so that delamination occurs only after other damage is precipitated, followed by fiber breakage leading to failure. A literature review of past work clearly shows that mechanical testing with simultaneous AE monitoring is a fruitful technique to study damage accumulation in composite systems. The acoustic-ultrasonic (AU) testing combines the high sensitivity of ultrasonics to internal damage and the method of acoustic emission technique to characterize elastic waves. As damage accumulates in the specimen along the wave path, the net internal damping increases and changes the wave parameters such as peak amplitude, duration, etc. accordingly. Additionally, a range of experimental results over the last decade has further shown that the mechanical deformation and electric resistance of carbon fiber reinforced polymers are coupled, so that the material is inherently a sensor of its own damage state. The monitoring of electric resistance and capacitance changes, linked to the modifications of the conduction paths in the composite, allows the detection of damage growth. It seems logical that a natural extension of these different approaches is the determination of damage mode, e.g., fiber breakage, matrix cracking or delamination, and damage size and position, based on combined measurements from these techniques. These multiple techniques will serve a two-fold purpose, namely, enable comparison as well as complement each other in case of incomplete damage mapping from one set of sensors For this study, we will consider carbon fiber-reinforced toughened bismaleimide, (IM7/5250-4) quasi-isotropic laminate coupons 12” long, 4” wide with hole at the center under tension. Figure 1 shows the damage which occurs around a 0.75” hole in a [45/0/-45/90]s graphite epoxy laminate obtained by radiography after unloading the test specimen from an applied stress of 50 Ksi. The failure stress for this laminate was 56.4 Ksi. Damage in the form of ply cracks in the 90, 45, and −45 plies and delamination around hole edges is clearly evident. The radiograph taken after unloading from a 50 Ksi stress level clearly shows the location and extent of damage, but contains no specific information about the sequence and the timing of damage events. Figure 2 shows stress-strain curves obtained from strain gages mounted at various distances away from the hole edge along with the far-field value. The stress-strain curves provide useful information regarding the initiation as well as the growth of the damage, as evidenced by jump in strain levels and onset of nonlinearity. Damage initiation is first picked up by the strain gage which is mounted closest to the hole edge at a stress level of 21 Ksi. Subsequently, other strain gages begin to sense damage growth as the applied stress level increases. The strain gage data provides useful information regarding initiation, growth and severity of damage, but it is difficult to assign specific damage modes and their location to the measurements. This example clearly demonstrates the needs, with the associated benefits, of the multiple sensor approach. In this work, three different hole sizes (0.25”, 0.5” and 0.75”) will be investigated. This example problem will enable us to examine the combined effects of cut-outs, matrix cracking, delamination and fiber breakage on the ability of various NDE techniques to assess damage. The development and growth of damage in the composite laminate with a hole under compression will be markedly different than in tension. Under compression, the major damage modes are fiber buckling and delamination, and will also be investigated.
9
Burns, Steven Robert, Daniel G. Cole, and Robert L. Clark. "The Adaptive Piezoelectric Microsensoriactuator for Active Control of Microcantilevers." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61804.
Full textAbstract:
The adaptive piezoelectric sensoriactuator is modified for use at the microscale to facilitate non-contact mode imaging of a microcantilever MEMS device in atomic force microscopy. The sensoriactuator is a truly colocated (sensor and actuator occupy exactly the same position on the structure) sensor/actuator device that uses a hybrid digital and analog design to drive a structure while simultaneously sensing the mechanical response. Using a piezoelectric material to both sense and actuate simultaneously is problematic because of the difficulty in resolving the sensory (mechanical) and actuator (electrical) parts of the output signal. Implementation of the adaptive piezoelectric sensoriactuator at the microscale results in a system with electrical quantities that are vastly reduced or increased from typical macroscale values, requiring more precise components and more careful design and construction of analog circuitry. For example, a typical micro-cantilever piezoelectric has a capacitance of on the order of 100 pF with an impedance at 50 kHz nearly 32 kΩ. The signal levels are significantly smaller with a typical piezoelectric current on the order of 100 nA. Thus, environmental noise can overwhelm signals in the system mandating the use of high precision operational amplifiers featuring ultra-low bias currents (±30 fA) and careful guarding or shielding of all circuitry. As reported in this paper, the adaptive piezoelectric microsensoriactuator has been successfully used to simultaneously sense and actuate while imaging using non-contact mode. The self-sensing microcantilever was successfully tested to produce a surface image using the microsensoriactuator to measure the movement of the microcantilever. The RMS value of the microsensoriactuator output is compared with the desired RMS output and the difference is used to drive an active resonance response controller. The active resonance response controller determines the control signal required to augment or attenuate the microcantilever’s motion to match the desired motion.
10
Jackson, Deborah A. "Stress Corrosion Cracking and Non-Destructive Examination of Dissimilar Metal Welds and Alloy 600." In 10th International Conference on Nuclear Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/icone10-22740.
Full textAbstract:
The United States Nuclear Regulatory Commission (USNRC) has conducted research since 1977 in the areas of environmentally assisted cracking and assessment and reliability of non-destructive examination (NDE). Recent occurrences of cracking in Alloy 82/182 welds and Alloy 600 base metal at several domestic and overseas plants have raised several issues relating to both of these areas of NRC research. The occurrences of cracking were identified by the discovery of boric acid deposits resulting from through-wall cracking in the primary system pressure boundary. Analyses indicate that the cracking has occurred due to primary water stress corrosion cracking (PWSCC) in Alloy 82/182 welds. This cracking has occurred in two different locations: in hot leg nozzle-to-safe end welds and in control rod drive mechanism (CRDM) nozzle welds. The cracking associated with safe-end welds is important due to the potential for a large loss of reactor coolant inventory, and the cracking of CRDM nozzle base metal and welds, particularly circumferential cracking of CRDM nozzle base metal, is important due to the potential for a control rod to eject resulting in a loss of coolant accident. The industry response in the U.S. to this cracking is being coordinated through the Electric Power Research Institute’s Materials Reliability Project (EPRI-MRP) in a comprehensive, multifaceted effort. Although the industry program is addressing many of the issues raised by these cracking occurrences, confirmatory research is necessary for the staff to evaluate the work conducted by industry groups. Several issues requiring additional consideration regarding the generic implications of these isolated events have been identified. This paper will discuss the recent events of significant cracking in domestic and foreign plants, discuss the limitations of NDE in detecting SCC, identify deficiencies in information available in this area, discuss the USNRC approach to address these issues, and discuss the development of an international cooperative effort.