Добірка наукової літератури з теми "Dielectric penetration"
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Статті в журналах з теми "Dielectric penetration"
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Tıraş, Buşra, Sercan Dede, and Filiz Altay. "Dielectric Properties of Foods." Turkish Journal of Agriculture - Food Science and Technology 7, no. 11 (November 22, 2019): 1805. http://dx.doi.org/10.24925/turjaf.v7i11.1805-1816.2650.
Повний текст джерелаАнотація:
Dielectric properties of materials are used for evaluating their interactions with electromagnetic energy. Dielectric properties of food materials are required for various applications in food industry such as microwave (at 915 or 2450 MHz), radio wave (at 13.56, 27.12 or 40.68 MHz) and magnetic field processing. In order to understand the response of food materials to electromagnetic energy, dielectric parameters must be determined as a function of frequency, temperature, composition and moisture content. In this review, the dielectric properties of different food groups were listed depending on temperature and frequency ranges. In addition to the literature data of dielectric properties, the penetration depths of microwave or radio wave through food groups were calculated. The effects of temperature and composition (mostly moisture content) on dielectric properties depend on the type of the food and sometimes on frequency. However, the effect of frequency is constant; increased frequency decreased dielectric constant, loss factor and penetration depth. The lowest calculated penetration depth belonged to the fish surimi gel as 3.39 mm at microwave frequency whereas they were high generally for fats, oily seeds and flours (max was 372602 mm for corn flour). It appears that dielectric properties of foods should be investigated further depending on the interactions between frequency, temperature and composition. And then, dielectric heating based on the aim of the process can be applied accordingly. Besides, it appears that the moisture content and especially the dipole rotation and the conductivity movements of the molecules in free water content of the food are some of the most critical factors influencing the dielectric properties of food materials.
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Singh, A., G. K. Meena, S. Kumar, and K. Gaurav. "ANALYSIS OF THE EFFECT OF INCIDENCE ANGLE AND MOISTURE CONTENT ON THE PENETRATION DEPTH OF L- AND S-BAND SAR SIGNALS INTO THE GROUND SURFACE." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-5 (November 15, 2018): 197–202. http://dx.doi.org/10.5194/isprs-annals-iv-5-197-2018.
Повний текст джерелаАнотація:
<p><strong>Abstract.</strong> We study the functional relationship between the dielectric constant of soil-water mixture and penetration depth of microwave signals into the ground at different frequency (L&amp;S) band and incidence angles. Penetration depth of microwave signals into the ground depends on the incidence angle and wavelength of radar pulses and also on the soil properties such as moisture content and textural composition. It has been observed that the longer wavelengths have higher penetration in the soil but the penetration capability decreases with increasing dielectric behaviour of the soil. Moisture content in the soil can significantly increase its dielectric constant. Various empirical models have been proposed that evaluate the dielectric behaviour of soil-water mixture as a function of moisture content and texture of the soil. In this analysis we have used two such empirical models, the Dobson model and the Hallikainen model, to calculate the penetration depth at L- and C-band in soil and compared their results. We found that both of these models give different penetration depth and show different sensitivity towards the soil composition. Hallikainen model is more sensitive to soil composition as compared to Dobson model. Finally, we explore the penetration depth at different incidence angle for the proposed L- and S-band sensor of upcoming NASA-ISRO Synthetic Aperture Radar (NISAR) mission by using Hallikainen empirical model. We found that the soil penetration depth of SAR signals into the ground decreases with the increase in soil moisture content, incident angle and frequency.</p>
3
Chipman, Daniel M. "Charge penetration in dielectric models of solvation." Journal of Chemical Physics 106, no. 24 (June 22, 1997): 10194–206. http://dx.doi.org/10.1063/1.474048.
Повний текст джерела
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YU Zhenfang, 余振芳, 马凤英 MA Fengying, 苏建坡 SU Jianpo, 陈明 CHEN Ming, and 池泉 CHI Quan. "Penetration Depth Calculation of Quarterwave Dielectric Mirrors." ACTA PHOTONICA SINICA 39, no. 11 (2010): 1967–70. http://dx.doi.org/10.3788/gzxb20103911.1967.
Повний текст джерела
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Kamaruddin, Mohd Johari, Muhammad Abbas Ahmad Zaini, Anwar Johari та Tuan Amran Tuan Abdullah. "Dielectric Properties for the Ring Opening Polymerisation of ε-Caprolactone". Applied Mechanics and Materials 493 (січень 2014): 621–27. http://dx.doi.org/10.4028/www.scientific.net/amm.493.621.
Повний текст джерелаАнотація:
A dielectric property study was performed across a wide range of frequencies and temperatures onring opening polymerisation of ε-caprolactone system in order to relate quantitatively their dielectric properties to microwave heating mechanisms. An analysis of the results concluded that heating mechanism of the polymerisation mixtures in a microwave field was controlled by the dielectric properties of monomer, where the monomer was the major component (>90 % volume/volume) as well as the component with highest dielectric loss and dissipation factor. The penetration depth of mixtures at 2.45 GHz was noted to increase from ~0.58 cm (at 20 C) to ~3.3 cm (at 150 °C). This small penetration depth limits the potential to achieve the successful scale up of a microwave-assisted polymerisation of ε-caprolactone in batch mode at 2.45 GHz. As a result, this will lead to inhomogeneous bulk temperature distribution within the polymerisation mixture and irreproducible chemistry. However, a fast heating rate based on a high value of dissipation factor and dielectric loss of the polymerisation mixtures shows potential to enable the reaction to be completed in a few seconds that may allow the polymerisation to be transferred to a continuous flow process. In so doing, small diameter tubular reactors can be employed hence removing this penetration depth issue. Thus, the polymerisation mixtures dielectric properties are worth to be considered to ensure the reliability and reproducibility of the microwave assisted synthesis of poly-ε-caprolactone at large scale production.
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Liu, Chenhui, Libo Zhang, Jinhui Peng, Wenwen Qu, Bingguo Liu, Hongying Xia, and Junwen Zhou. "Dielectric Properties and Microwave Heating Characteristics of Sodium Chloride at 2.45 GHz." High Temperature Materials and Processes 32, no. 6 (December 1, 2013): 587–96. http://dx.doi.org/10.1515/htmp-2013-0008.
Повний текст джерелаАнотація:
AbstractThe effects of moisture content and temperature on the dielectric property of sodium chloride were investigated by using open-ended senor dielectric measurement system at the frequency of 2.45 GHz. Moisture content is a major influencing factor in the variation of dielectric properties. Dielectric constant, loss factor and loss tangent all increase linearly with moisture content increasing. Three predictive models were developed to obtain dielectric constant, loss factor, loss tangent and of sodium chloride as linear functions of moisture content. Temperature between 20 °C and 100 °C has a positive effect on dielectric constant and loss factor. Penetration depth decreased nonlinearly with moisture and temperature increasing. A predictive model was developed to calculate penetration depth for sodium chloride as a fifth function of moisture content. In addition, the measurements indicate that the particles temperature increases linearly with microwaving heating time at different power levels. The knowledge gained from these results is useful in developing more effective applications of microwave drying and designing better sensors for measuring moisture content of sodium chloride.
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Beh, Chong You, Ee Meng Cheng, Nashrul Fazli Mohd Nasir, Mohd Shukry Abdul Majid, Shing Fhan Khor, Mohd Ridzuan Mohd Jamir, Emma Ziezie Mohd Tarmizi, and Kim Yee Lee. "Regression Analysis of the Dielectric and Morphological Properties for Porous Nanohydroxyapatite/Starch Composites: A Correlative Study." International Journal of Molecular Sciences 23, no. 10 (May 19, 2022): 5695. http://dx.doi.org/10.3390/ijms23105695.
Повний текст джерелаАнотація:
This paper aims to investigate the dielectric properties, i.e., dielectric constant (ε′), dielectric loss factor (ε″), dielectric tangent loss (tan δ), electrical conductivity (σ), and penetration depth (Dp), of the porous nanohydroxyapatite/starch composites in the function of starch proportion, pore size, and porosity over a broad band frequency range of 5 MHz–12 GHz. The porous nanohydroxyapatite/starch composites were fabricated using different starch proportions ranging from 30 to 90 wt%. The results reveal that the dielectric properties and the microstructural features of the porous nanohydroxyapatite/starch composites can be enhanced by the increment in the starch proportion. Nevertheless, the composite with 80 wt% of starch proportion exhibit low dielectric properties (ε′, ε″, tan δ, and σ) and a high penetration depth because of its highly interconnected porous microstructures. The dielectric properties of the porous nanohydroxyapatite/starch composites are highly dependent on starch proportion, average pore size, and porosity. The regression models are developed to express the dielectric properties of the porous nanohydroxyapatite/starch composites (R2 > 0.96) in the function of starch proportion, pore size, and porosity from 1 to 11 GHz. This dielectric study can facilitate the assessment of bone scaffold design in bone tissue engineering applications.
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Liu, Boyan, Yu Lei, Shitao Sun, and Jie Zhang. "Thompson-Lampard Theorem for Dielectric Characteristics Detection of Generator Stator Insulation." Journal of Physics: Conference Series 2246, no. 1 (April 1, 2022): 012039. http://dx.doi.org/10.1088/1742-6596/2246/1/012039.
Повний текст джерелаАнотація:
Abstract The insulation of large generator stator winding will be gradually aging in the long-term operation process. The traditional aging test method cannot accurately locate the non-penetrating local defects of winding. Interdigital electrode is widely used in the fields of environmental monitoring and food detection because of its excellent characteristics such as self-closing and unidirectional penetration, but it has not been popularized in the identification of generator insulation aging. The paper proposes an interdigital electrode structure based on the Thompson-Lampard theory. The electrode suitable for dielectric characteristic detection of stator winding, and the electrode structure is optimized by using the finite element method from the parameters of signal strength, sensitivity and penetration depth. With the help of optimising, the measuring accuracy of the electrode can reach 0.1 level. Then, the different moisture conditions of water-cooled generator and air-cooled generator are simulated to verify the feasibility that interdigital electrode can detect insulation moisture which is an important factor in accelerating insulation aging. Finally, the moisture depth detection results show that the electrode combination based on the Thompson-Lampard theory can be used to locate moisture depth accurately, it is of great significance for the prevention of insulation aging and the pre-diagnosis.
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Josh, Matthew, Melvyn J. Lintern, Anton W. Kepic, and Mike Verrall. "Impact of grain-coating iron minerals on dielectric response of quartz sand and implications for ground-penetrating radar." GEOPHYSICS 76, no. 5 (September 2011): J27—J34. http://dx.doi.org/10.1190/geo2010-0321.1.
Повний текст джерелаАнотація:
An unexpected result of ground-penetrating radar (GPR) surveys in the Great Victoria Desert (South Australia) was the lack of returning signal in what appeared to be a favorable environment for GPR, with dry silica sand and calcrete aggregates in the near surface. We found that the dielectric response of the dry sand samples had much higher dielectric losses than comparable sands from Western Australia and that the dielectric losses are controlled by the presence of iron oxide minerals, although iron concentrations themselves are only around 0.4%. The samples contained over 90% quartz, with subsidiary amounts of carbonates, kaolin, and smectite occurring with the iron oxide minerals as a coating on the quartz grains. An acid washing procedure removed the reducible iron oxide minerals from the clay coating but left the clays substantially unaltered. Subsequent dielectric and magnetic analysis of the samples indicates that the iron oxide minerals removed during the washing process are responsible for the reduction of GPR penetration at 250 MHz from approximately 10 m to only 1 m.
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Das, Aparna, Ram Naresh Yadav, and Bimal K. Banik. "Microwave-Induced Surface-Mediated Highly Efficient Regioselective Nitration of Aromatic Compounds: Effects of Penetration Depth." Asian Journal of Chemistry 33, no. 9 (2021): 2203–6. http://dx.doi.org/10.14233/ajchem.2021.23131.
Повний текст джерелаАнотація:
Surface mediated highly regioselective nitration of aromatic compounds under diverse microwaveinduced conditions was investigated in this work. The effects of the penetration depth of the surfaces were found to be more crucial than other dielectric parameters. Despite significant progress of microwave-induced reactions, no reports have examined the penetration depth of the surfaces used in these processes.
Дисертації з теми "Dielectric penetration"
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Blandin, Christopher. "Production of dielectric materials." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26568.
Повний текст джерелаАнотація:
Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009.Committee Chair: Colton, Jonathan; Committee Member: Schultz, John; Committee Member: Zhou, Min. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Браге, Ксенія Сергіївна. "Метод вимірювання НВЧ- параметрів матеріалів на основі тонкого діелектричного резонатора". Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/22979.
Повний текст джерелаАнотація:
В даній роботі розглянуто питання загальних теоретичних відомостей з складених та тонких діелектричних резонаторів та методів вимірювання вимірювання НВЧ параметрів діелектричних матеріалів. Досліджено метод тонкого діелектричного резонатора та наведено результати експерементальних досліджень. При досліджені тонких діелектричних плівок виникають труднощі, тому що методи не забезпечують достатньої точності. При дослідженні метода тонких плівок результати показали, що при зменшенні товщини базового резонатора, збільшується точність. Тому метою роботи є адаптація методу складеного діелектричного резонатора для вимірювання параметрів тонких плівок.
Для досягнення поставленої мети необхідно було вирішити наступні задачі:
1. Проаналізувати існуючи методи вимірюваняя НВЧ – параметрів діелектричних матеріалів.
2. Проаналізувати властивості тонкого діелектричного резонатора (ТДР).
3. Запропонувати метод дослідження параметрів тонких плівок на основі ТДР.
4. Експерементально перевірити метод тонких плівок на основі ТДР.
Предметом і об’єктом даної робот є:
Об’єкт: тонкий діелектричний резонатор
Предмет: електродинамічні властивості тонкого діелектриного резонатора
Наукова новизна:
Теоретичне та експериментальне дослідження електро-динамічних властивостей ТДР показує, що на основі ТДР можна з достатньою точністю вимірювати НВЧ – властивості тонких діелектричних плівок.In the given work, the nutritional pockets of the teoretical publications are stored in those thin dielectric resonators and the method of determining the NVH parameters in the power electronics. The method of a thin dielectric resonator is applied to the result of the experimental data. When study slim dielectric films arise difficulties, to that method do not gave accuracy. When the method of thin plots is used, the results have been shown, when the basic resonator is changed, the accuracy is determined. To the method of robotics is adaptation to the method of the stored dielectric resonator for the parameterization of thin cells. For achivment it's delivered goal it was necessary to solve the problem: 1. Analyze existing methods 2. Analyze power of a thin dielectric resonator (TDR). 3.Propose method of study parameters in the small films on the basis of the TDR. 4. Experimentally check method of thin plvok on the basis of the TDR. The subject і objective of this work is: Ob'ekt: thin dielectric resonator Subject: Electrodynamic power of a thin dielectric resonator Science novelty: Theoretically, this experiment is complementary to the electric-dynamical authorities of the TDR, but on the basis of the TDR, it is possible to obtain the accuracy of the NVCH - the power of subtle electrical add-ons.
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Quevedo-Lopez, Manuel Angel. "Materials properties of hafnium and zirconium silicates: Metal interdiffusion and dopant penetration studies." Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3221/.
Повний текст джерелаАнотація:
Hafnium and Zirconium based gate dielectrics are considered potential candidates to replace SiO2 or SiON as the gate dielectric in CMOS processing. Furthermore, the addition of nitrogen into this pseudo-binary alloy has been shown to improve their thermal stability, electrical properties, and reduce dopant penetration. Because CMOS processing requires high temperature anneals (up to 1050 °C), it is important to understand the diffusion properties of any metal associated with the gate dielectric in silicon at these temperatures. In addition, dopant penetration from the doped polysilicon gate into the Si channel at these temperatures must also be studied. Impurity outdiffusion (Hf, Zr) from the dielectric, or dopant (B, As, P) penetration through the dielectric into the channel region would likely result in deleterious effects upon the carrier mobility. In this dissertation extensive thermal stability studies of alternate gate dielectric candidates ZrSixOy and HfSixOy are presented. Dopant penetration studies from doped-polysilicon through HfSixOy and HfSixOyNz are also presented. Rutherford backscattering spectroscopy (RBS), heavy ion RBS (HI-RBS), x-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HR-TEM), and time of flight and dynamic secondary ion mass spectroscopy (ToF-SIMS, D-SIMS) methods were used to characterize these materials. The dopant diffusivity is calculated by modeling of the dopant profiles in the Si substrate. In this disseration is reported that Hf silicate films are more stable than Zr silicate films, from the metal interdiffusion point of view. On the other hand, dopant (B, As, and P) penetration is observed for HfSixOy films. However, the addition of nitrogen to the Hf - Si - O systems improves the dopant penetration properties of the resulting HfSixOyNz films.
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Doria, Katerin Guerrero. "Desenvolvimento de uma sonda TDR helicoidal para uso em conjunto com o ensaio CPT." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-06012016-094209/.
Повний текст джерелаАнотація:
A reflectometria no domínio do tempo permite estimar o teor de umidade de um meio através da sua correlação com a constante dielétrica. Uma sonda helicoidal TDR, que pode ser cravada em conjunto outros ensaios de penetração in situ para a estimativa do teor de umidade em diversas profundidades, tem aplicação interessante para a investigação geotécnica do subsolo. No presente trabalho, uma sonda TDR foi adaptada e utilizada em conjunto ao ensaio CPT para caracterização de um perfil de solo arenoso não saturado que ocorre na região de Bauru (SP). A calibração dessa sonda foi feita em laboratório especificamente para esse solo. As equações de calibração que mostraram os melhores resultados foram definidas correlacionando a constante dielétrica, condutividade elétrica aparente e a massa específica seca com o teor de umidade. Com o intuito de melhorar a acurácia na determinação do teor de umidade em campo e eliminar possíveis interferências no registro da onda eletromagnética, foram efetuadas modificações em algumas características do projeto original dessa sonda. Tais modificações consistiram em separar os eletrodos condutores e as partes metálicas da sonda, e eliminar o cabo coaxial de extensão, conectando a sonda diretamente a um cabo coaxial de 12 m de comprimento. Tais mudanças levaram a uma melhoria significativa na determinação do perfil de teor de umidade do local estudado. Os valores de teor de umidade de campo determinados usando o TDR ao longo de 8 m de profundidade foram comparados com os valores de referência obtidos de amostras deformadas retiradas com trado mecânico. O erro médio na estimativa do perfil de teor de umidade gravimétrico utilizando a sonda TDR helicoidal foi de 1.61%, na última campanha de ensaios realizados. Os resultados dessa pesquisa indicam que esta ferramenta é adequada para estimar do perfil de teor de umidade para uso em conjunto com o ensaio CPT.The time domain reflectometry allows estimating the moisture content of a medium by means of its correlation with the dielectric constant. A coil TDR probe, which can be driven into the ground together with others in situ penetration tests, can be used to estimate the moisture content at different depths. It is an interesting approach for geotechnical site characterization. In this work, a coil TDR probe was adapted and used in combination with the CPT test for the site characterization of an unsaturated sandy soil profile which occurs in the region of Bauru (SP). The probe calibration was performed in laboratory specifically for that soil. The calibration equation, which presented the best results, were defined correlating the dielectric constant, electrical conductivity and dry density with the moisture content. In order to improve the accuracy for determining the water content in the field and to eliminate possible interference on the electromagnetic wave registration, modifications were made in some characteristics of the original design of this probe. Such modifications consisted in separating the conductive electrodes from the metal parts of the probe, and eliminating the coaxial extension cable, connecting the probe directly to a coaxial cable 12 m long. Such changes have led to a significant improvement in the determination of the moisture content profile of the studied site. The moisture content values determined in situ by using the TDR along 8 m depth were compared with reference values obtained from disturbed soil samples collected using mechanical augers. The root mean square error of the gravimetric water content profile using the TDR coil probe was 1.61% in the last test campaign. The results of this research indicate that this tool is suitable to estimate the gravimetric moisture content together with the CPT test.
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Evans, Robert D. "Optimising ground penetrating radar (GPR) to assess pavements." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/20465.
Повний текст джерелаАнотація:
Ground penetrating radar (GPR) technology has existed for many decades, but it has only been in the last 20 to 30 years that it has undergone great development for use in near surface ground investigations. The early 1980's saw the first major developments in the application of GPR for pavements (i.e. engineered structures designed to carry traffic loads), and it is now an established investigation technique, with generic information included in several national standard guidance documents. Analysis of GPR data can provide information on layer depths, material condition, moisture, voiding, reinforcement and location of other features. Assessing the condition of pavements, in order to plan subsequent maintenance, is essential to allow the efficient long-term functioning of the structure and GPR has enhanced and improved the range and certainty of information that can be obtained from pavement investigations. Despite the recent establishment of the technique in pavement investigation, the current situation is one in which GPR is used routinely for pavement projects in only a minority of countries, and the specialist nature of the technique and the sometimes variable results that are obtained can mean that there is both a lack of appreciation and a lack of awareness of the potential information that GPR can provide. The fact that GPR is still a developing technique, and that many aspects of its use are specialised in their nature, means that there are also several technical aspects of GPR pavement investigations which have not been fully researched, and knowledge of the response of GPR to some material conditions has not been fully established. The overall aim of this EngD research project was to provide improved pavement investigation capabilities by enhancing the methodologies and procedures used to obtain information from GPR. Several discrete research topics were addressed through various research methods including a literature review, fieldwork investigations, experimental laboratory investigations and a review of previously collected data. The findings of the research allowed conclusions and recommendations to be made regarding improved fieldwork methodologies, enhancing information and determining material condition from previously collected GPR data, assessing the effect of pavement temperature and moisture condition on GPR data and also on managing errors and uncertainty in GPR data. During the EngD project, a number of documents and presentations have been made to publicise the findings both within the EngD sponsoring company (Jacobs) and externally, and an in-house GPR capability has been established within Jacobs as a direct result of the EngD project.
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Loulizi, Amara. "Development of Ground Penetrating Radar Signal Modeling and Implementation for Transportation Infrastructure." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/26133.
Повний текст джерелаАнотація:
Ground penetrating radar (GPR) technology has been used for the past 20 years for a variety of applications to assess transportation infrastructure. However, the main issue after all these years remains: "How well does GPR work and under what conditions?" Results show that GPR works well for some situations, but is not an appropriate tool for other situations. It is not used currently on a routine basis by the US Departments of Transportation (DOTs) due mainly to difficulties encountered with data interpretation. Data interpretation difficulties are mainly attributed to the fact that images obtained from the reflected signals are not photographs of the features that are beneath the surface being investigated. The images show the amplitude of the radar-reflected signals from the interfaces with different dielectric properties. Therefore, a considerable amount of experience and operator skill may be required to correctly interpret sub-surface radar results. To better understand reflected GPR signals, this research was conducted with the following objectives: to determine the dielectric properties of concrete over the used GPR frequency range; to synthesize the reflected air-coupled radar signals and compare them with measured waveforms; to model and study the effects of simulated defects in concrete on the reflected air-coupled and ground-coupled radar signals; and to validate the research results in the field by predicting layer thicknesses of flexible pavements and detecting moisture in flexible pavement systems. Several concrete slabs, 1.5x1.5 m, were constructed with known thicknesses, simulated defects, and different reinforcement configurations. The concrete mixes included four different bridge deck mixes and one concrete pavement mix used in the State of Virginia. Results have shown that the dielectric constant of concrete is frequency and mix dependent. However, modeling the reflected signals using an average complex dielectric constant over the entire radar frequency range led to modeled waveforms comparable to the measured waveforms. Although air- and water-filled voids did distort the reflected waveforms, a model was developed to predict the reflected waveforms from the simulated defects. Reinforcement was found to affect the reflected waveforms only when it was oriented in a direction perpendicular to the GPR antennas. A model was also developed to predict the GPR waveforms obtained from flexible pavements. This model could be used in a procedure to measure layer thicknesses more accurately by including losses that occur inside the pavement materials. Two different case studies, where a ground-coupled GPR system was used to locate moisture at different layers, have led to the conclusion that the ground-coupled GPR is a feasible tool to detect moisture inside pavements.Ph. D.
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Рудяк, Юрій Аронович, Юрий Аронович Рудяк та Yu А. Rudyak. "Оптичні експериментально-розрахункові методи визначення напружено-деформованого та граничного станів прозорих діелектриків". Thesis, Тернопільський національний технічний університет ім. Івана Пулюя, 2015. http://elartu.tntu.edu.ua/handle/123456789/5827.
Повний текст джерелаАнотація:
Робота виконана на кафедрі технології та обладнання зварювального виробництва Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України.Захист відбувся в 2015 р. на засіданні спеціалізованої вченої ради Д58.052.01 у Тернопільському національному технічному університеті імені Івана Пулюя за адресою: 46001, м. Тернопіль, вул. Руська, 56, навчальний корпус №2, аудиторія №79.
З дисертацією можна ознайомитися у науково-технічній бібліотеці Тернопільського національного технічного університету імені Івана Пулюя за адресою: 46001, м. Тернопіль, вул. Руська, 56.Дисертаційна робота присвячена розв’язанню наукової проблеми – підвищення ефективності та функціональних можливостей експериментальних досліджень шляхом розробки експериментально-розрахункових оптичних методів визначення напружено-деформованого та граничного стану прозорих діелектриків на основі аналізу параметрів тензора діелектричної проникності. Теоретично обґрунтовано та експериментально підтверджено новий метод визначення НДС, який використовує п’єзооптичний ефект поглинаючого середовища (метод поглинання – МП), одержано формули визначення КІН за даними МП. Теоретично обґрунтовано та експериментально підтверджено новий метод визначення НДС, який базується на ефекті дифузного поверхневого розсіювання (МДПР), одержано формули визначення КІН (моментів) за допомогою даного методу, а також сумісним вимірюванням даних МДПР та фотопружності. Розроблено та реалізовано модель оптичного тензодатчика, який працює на основі МДПР, обґрунтовано застосування методу для оцінки «зони шийкоутворення» біля вершини тріщини. Розвинуто поляризаційно-оптичний метод для розв’язання таких задач експериментальної механіки руйнування, як визначення КІН КІ, КІІ, КІІІ, для неоднорідного основного напруженого стану та малих за величиною (до ) картин оптичної анізотропії, для випадків великих різниць оптичного ходу ( ) та значних градієнтів, коли важко визначити нульову ізохрому. Розроблено фізико-механічний критерій граничного стану діелектриків (критерій тензора діелектричної проникності - ТДП), експериментально досліджено, згідно критерію ТДП, граничний стан пластин з оргскла та оболонок з епоксидної смоли з тріщинами. За допомогою модифікованих методик поляризаційно-оптичного методу та розробленого фізико-механічного критерію ТДП проведено комплексне дослідження напруженого та граничного станів багатошарових структур (триплексів) при температурі Т=213 К і при можливій наявності тріщиноподібних дефектів у їх складових частинах (елементах).
Диссертационная работа посвящена решению научной проблемы –повышению эффективности и функциональных возможностей экспериментальных исследований путем разработки экспериментально-расчетных оптических методов определения напряженно-деформированного и предельного состояния прозрачных диэлектриков на основе анализа параметров тензора диэлектрической проницаемости. Теоретически обоснован и экспериментально подтвержден метод определения НДС, который использует пьезооптический эффект поглощающей среды (метод поглощения - МП), действие которого основано на анализе величин изменения мнимой части компонент тензора диэлектрической проницаемости (ТДП) при нагружении объекта. Метод предоставляет принципиальную возможность определения НДС объектов, изготовленных из непрозрачных в видимом диапазоне диэлектриков и позволяет определять сразу отдельно квазиглавные напряжения и деформации, а не их линейные комбинации, как в поляризационно-оптических (разности) и когерентно-оптических (суммы) методах. Предложенный метод поглощения применен для определения величин КИН при исследовании объектов, содержащих трещиноподобные дефекты (получены формулы определения КИН по данным МП). Теоретически обоснован и экспериментально подтвержден метод определения НДС, который использует эффект диффузного поверхностного рассеивания (метод диффузного поверхностного рассеивания – МДПР). Предложенный метод основывается на измерениях перераспределения интенсивностей зеркальной и диффузных составляющих рассеянного поверхностью объекта светового потока при локальном изменении ее кривизны. Метод позволяет проводить измерения в широком диапазоне изменения величин деформаций: от порогового значения чувствительности до разрушения объектов (10-2 – для полимеров, 10-0- для эластомеров), значительно превышая диапазон измерения спекл-интерферометрии. Получены формулы определения КИН (моментов) по данным МДПР для симметричного относительно берегов трещины моментного состояния (определения К3) и несимметричного моментного состояния (определения К3 и К4). Разработаны и реализованы модели оптических датчиков деформаций, которые работают на эффекте диффузного поверхностного рассеивания (датчики МДПР). Чувствительным элементом датчика первого конструктивного исполнения является изогнутая пластинка, а второго – выемка с диффузнорассеивающей поверхностью. Датчик МДПР, чувствительным элементом которого является выемка, не крепится определенным образом на поверхности объекта, а является частью приповерхностного слоя. Такая конструкция позволяет повысить точность измерений за счет отсутствия погрешностей в системе “датчик–склеивающий слой–поверхность объекта”. Предложен физико-механический критерий предельного состояния диэлектриков (критерий тензора диэлектрической проницаемости – ТДП). Критерий основывается на изменении компонент тензора диэлектрической проницаемости при нагружении объекта и позволяет интегрально учитывать влияние как механических, так и физических факторов (температуры, влажности, радиации) на предельное состояние диэлектриков. В данном критерии при изменении физических факторов изменяется не только предел прочности (как в классических механических теориях), а и выражение для эквивалентного напряжения за счет изменения величины соотношения оптико-механических констант С1/С2. Предложенный критерий ТДП позволяет определять долговременную прочность полимеров при постоянной нагрузке. Модифицирован поляризационно-оптический метод исследования натурных объектов с трещинами для малых по величине (до 1λ, где λ – длина волны зондирующего излучения) картин оптической анизотропии и для случаев больших разностей оптического хода (>8 λ) и значительных градиентов, при которых сложно определить нулевую изохрому. Исследована кинетика разрушения и предельное состояние неорганического силикатного стекла (как составной части гомогенных и гетерогенных триплексов). Проанализированы, при помощи критерия ТДП, данные разрушения пластин из органического стекла (как составной части гетерогенных триплексов) с краевыми трещинами. На моделях из эпоксидных смол ЭПСА и ЭД-20М показано конструкционное и технологическое влияние обрамления на распределение величин КИН при прорастании поверхностных трещин (надрезов) в сквозные в склеивающем слое триплексов. С помощью модифицированных методик поляризационно-оптического метода и разработанного физико-механического критерия ТДП проведено комплексное исследование напряженного и предельного состояния гомогенных и гетерогенных триплексов при сниженных температурах (до Т=213 К), с обрамлением и без, при возможном наличии трещиноподобных дефектов в их составных частях (элементах): неорганическом силикатном стекле, органическом стекле и склеивающем слое. Это позволило определить влияние гетерогенности и обрамления, а также получить численные результаты оценки НДС и предельного состояния для различных вариантов триплексов и выбрать оптимальный: гетерогенный триплекс без обрамления.
Thesis is dedicated to the solution of a scientific problem – developing of the optical experimental and computational methods for determining the stress-strain and limit states of transparent dielectrics on the basis of the analysis of the dielectric penetration tensor. The author theoretically justified and experimentally confirmed the new method for determining the SDS, that uses the piezooptic effect of absorbing environment (the absorption method – AM), obtained the formulae for finding SIF accord Кing to the data of the AM. The author theoretically justified and experimentally confirmed a new method for determining the SDS on the basis of the method of diffuse surface scattering (MDSS), obtained the formulae for finding SIF with help of this method and due to the joint estimation of data of the MDSS and photo resilience as well. The author developed and realized the model of optical strain gauge that works on the basis of the MDSS, the application of the method for estimation of “neck-like formation area” at the crack tip. The author developed the polarized and optical method for solution of such tasks of experimental mechanics of destruction like SIF F1 F2 F3 in the case of finding heterogeneous stress state and the small size (<1λ) pictures of optical anisotropy in the case of significant optical motion’s differences (>8λ) and significant gradients when it is difficult to determine the zero isochromat. The author developed the physical-mechanical criterion of boundary state of dielectrics (the criterion of dielectric penetration tensor (DPT)) and experimentally investigated according to the criterion of DPT the boundary state of the organic glass plates and epoxy resin’s casing with cracks. Due to the modified polarized and optical method and developed physical-mechanical criterion of DPT was conducted the complex study of stress and boundary states of multilayer structures (triplexes) with the temperature T= 213 K and with the possible availability of crack-like defects in their component parts (elements).
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Birch, Max (Max Lariviere). "Development of a cavity backed bowtie antenna with dielectric matching for ground penetrating radar." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52186.
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Thesis (MScEng)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: An antenna for ground level deployed Ground Penetrating Radar applications is presented. The antenna is matched to the ground via a low impedance dielectric matching section improving the radiation pattern and input impedance characteristics. A bowtie antenna was used for the design with the edges rounded to stabilize the resonant frequency. The radiation pattern was focused to the one side of the antenna for ground penetration using a non-absorptive metallic cylindrical air filled cavity. Edge reflections from the antenna were reduced by means of discrete resistor terminations between the antenna and the cavity. A wire equivalent of the solid metallic antenna was investigated giving similar characteristics to that of the solid antenna. The radiation pattern deformation arising from transmitting a wave from an antenna in air into the ground due to the impedance mismatch was investigated. This was overcome with the use of a polypropylene dielectric slab inserted between the antenna and the ground. Together with improving the radiation pattern the antenna was less sensitive to ground parameter variations and to an air gap introduced between the slab and the ground. This was implemented as a wheel mounted system with adjustable height settings depending on the terrain. A pair of mounted antennas was constructed to be tested on an existing bistatic Stepped Frequency Continuous Wave radar operating in the 50-400 MHz band developed by the University of Cape Town. This antenna is seen as providing a solution to the problem of coupling an antenna to a low wave impedance medium such as ground.
AFRIKAANSE OPSOMMING: 'n Antenne word vir Grond Penetrerende Radar toepassings voorgestel. Dit is spesifiek ontwikkel vir oppervlak ontplooide stelsels ontwerp. Die antenne is aangepas tot die grond deur middel van 'n diëlektriese aanpassingseksie wat die starlingspatroon en intree-impedansie karakteristieke verbeter. Die antenne is tot die grond toe aangepas deur middel van 'n diëlektriese aanpassingseksie wat die starlingspatroon en intree-impedansie karakteristieke verbeter. 'n Strikdas antenne was gebruik vir die ontwerp, met die kante gerond om die resonante freqwensie te stabiliseer. Om die stralingspatroon van die antenne na een kant toe te fokus was 'n nie-absorbeerede metaleiese, luggevulde, silindriese holte daaragter geplaas om die energie vorentoe te weerkaats. Weerkaatsings van die rand van die antenne word onderdruk met behulp van koppelende weerstande tussen die antenne en die holte. A draad ekwivalent van die antenne was ook ondersoek met goeie ooreenstemming met die soliede strikdas. Die impedansie wanaanpassing wat ontstaan as 'n antenne wat in lug is, in die grond in straal veroorsaak dat die stralingspatroon van die antenne vervorm word. Dit was gevind dat deur 'n aanpassings blad van 'n diëlektriese materiaal, naamlik polipropileen, gebruik te maak tussen die antenne en die grond dat dit die probleem oplos. Saam met dit was gevind dat die antenne minder sensitief was vir veranderings in grondparameters en ook vir 'n lug gaping tussen die blad en die grond. Die het gemaak dat die antenne op wiele gemonteer kon word met verstelbare hoogte afhangend van die terrein. 'n Stel geskaleerde antennes was gemaak om op 'n beskikbare bistatiese Trap Frekwensie Kontinue Golf radar te werk. Dit werk oor die 50-400 MHz band en was ontwikkel deur die Universitiet van Kaapstad. Die antenne word gesien as 'n oplossing vir antenne koppelingsprobleme ondervind by laë golf impedansie materiale.
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Reichmann, Markus. "Auslegung von Mikrowellen-Thermoprozess-Anlagen unter Nutzung von hochfrequenz-technischen Prinzipien." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2011. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-67409.
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Um der Mikrowellenerwärmung als Single- oder Hybridanwendung im industriellen Ofenbau ein weiteres Anwendungsspektrum zu eröffnen, wird dem Anlagenkonstrukteur im Rahmen dieser Arbeit eine Aufstellung von Entwicklungsprioritäten und Konstruktionshinweisen übergeben. Für eine energieeffiziente Ausnutzung des technologischen Potenzials wird hierbei nicht - wie in der Vergangenheit - die Feldstärkenverteilung, sondern das Reflexionsverhalten in den Vordergrund gestellt.
Durch die Entwicklung und den Aufbau eines Messplatzes zur Bestimmung temperaturspezifischer Dielektrizitätsparameter konnte die Realitätsnähe der Simulation für die anwendungsorientierte Applikatorentwicklung gesteigert werden.
Die Anwendbarkeit der Auslegungskriterien wird im Rahmen der Projektierung und des Aufbaus einer Beispielanlage zur Entbinderung von keramischen Grünkörpern und bei der Entwicklung zahlreicher mikrowellenspezifischer Anlagenbauteile verifiziert.
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Lahouar, Samer. "Development of Data Analysis Algorithms for Interpretation of Ground Penetrating Radar Data." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/11051.
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According to a 1999 Federal Highway Administration statistic, the U.S. has around 8.2 million lane-miles of roadways that need to be maintained and rehabilitated periodically. Therefore, in order to reduce rehabilitation costs, pavement engineers need to optimize the rehabilitation procedure, which is achieved by accurately knowing the existing pavement layer thicknesses and localization of subsurface defects. Currently, the majority of departments of transportation (DOTs) rely on coring as a means to estimate pavement thicknesses, instead of using other nondestructive techniques, such as Ground Penetrating Radar (GPR). The use of GPR as a nondestructive pavement assessment tool is limited mainly due to the difficulty of GPR data interpretation, which requires experienced operators. Therefore, GPR results are usually subjective and inaccurate. Moreover, GPR data interpretation is very time-consuming because of the huge amount of data collected during a survey and the lack of reliable GPR data-interpretation software. This research effort attempts to overcome these problems by developing new GPR data analysis techniques that allow thickness estimation and subsurface defect detection from GPR data without operator intervention. The data analysis techniques are based on an accurate modeling of the propagation of the GPR electromagnetic waves through the pavement dielectric materials while traveling from the GPR transmitter to the receiver. Image-processing techniques are also applied to detect layer boundaries and subsurface defects. The developed data analysis techniques were validated utilizing data collected from an experimental pavement system: the Virginia Smart Road. The layer thickness error achieved by the developed system was around 3%. The conditions needed to achieve reliable and accurate results from GPR testing were also established.Ph. D.
Книги з теми "Dielectric penetration"
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Ceng zhuang ti xi jie dian te xing fan yan li lun ji qi ying yong. Beijing: Ke xue chu ban she, 2011.
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Al-Qadi, Imad L. Ground-penetrating radar calibration at the Virginia Smart Road and signal analysis to improve prediction of flexible pavement layer thicknesses. Charlottesville, Va: Virginia Transportation Research Council, 2005.
Знайти повний текст джерелаЧастини книг з теми "Dielectric penetration"
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Tseng, H. H. "Silicon Oxynitride Gate Dielectric for Reducing Gate Leakage and Boron Penetration Prior to High-k Gate Dielectric Implementation." In High Dielectric Constant Materials, 195–220. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/3-540-26462-0_7.
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Serdar Turk, A., and D. S. Armagan Sahinkaya. "Partial Dielectric Loaded TEM-Horn Design for UWB Ground Penetrating Impulse Radar Systems." In Ultra-Wideband, Short-Pulse Electromagnetics 7, 306–15. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-37731-5_34.
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K. M., Sandhya, Litty Thomas Manamel, and Bikas C. Das. "Doping of Semiconductors at Nanoscale with Microwave Heating (Overview)." In Microwave Heating - Electromagnetic Fields Causing Thermal and Non-Thermal Effects. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.95558.
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Incorporation of dopants efficiently in semiconductors at the nanoscale is an open challenge and is also essential to tune the conductivity. Typically, heating is a necessary step during nanomaterials’ solution growth either as pristine or doped products. Usually, conventional heating induces the diffusion of dopant atoms into host nanocrystals towards the surface at the time of doped sample growth. However, the dielectric heating by microwave irradiation minimizes this dopant diffusion problem and accelerates precursors’ reaction, which certainly improves the doping yield and reduces processing costs. The microwave radiation provides rapid and homogeneous volumetric heating due to its high penetration depth, which is crucial for the uniform distribution of dopants inside nanometer-scale semiconducting materials. This chapter discusses the effective uses of microwave heating for high-quality nanomaterials synthesis in a solution where doping is necessary to tune the electronic and optoelectronic properties for various applications.
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Singh, Sukhmander, Ashish Tyagi, and Bhavna Vidhani. "Physics of Absorption and generation of Electromagnetic Radiation." In Electromagnetic Wave Propagation for Industry and Biomedical Applications [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99037.
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The chapter is divided into two parts. In the first part, the chapter discusses the theory of propagation of electromagnetic waves in different media with the help of Maxwell’s equations of electromagnetic fields. The electromagnetic waves with low frequency are suitable for the communication in sea water and are illustrated with numerical examples. The underwater communication have been used for the oil (gas) field monitoring, underwater vehicles, coastline protection, oceanographic data collection, etc. The mathematical expression of penetration depth of electromagnetic waves is derived. The significance of penetration depth (skin depth) and loss angle are clarified with numerical examples. The interaction of electromagnetic waves with human tissue is also discussed. When an electric field is applied to a dielectric, the material takes a finite amount of time to polarize. The imaginary part of the permittivity is corresponds to the absorption length of radiation inside biological tissue. In the second part of the chapter, it has been shown that a high frequency wave can be generated through plasma under the presence of electron beam. The electron beam affects the oscillations of plasma and triggers the instability called as electron beam instability. In this section, we use magnetohydrodynamics theory to obtain the modified dispersion relation under the presence of electron beam with the help of the Poisson’s equation. The high frequency instability in plasma grow with the magnetic field, wave length, collision frequency and the beam density. The growth rate linearly increases with collision frequency of electrons but it is decreases with the drift velocity of electrons. The real frequency of the instability increases with magnetic field, azimuthal wave number and beam density. The real frequency is almost independent with the collision frequency of the electrons.
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"The 2D Scattering Equations for Dielectric Targets." In Introduction to Ground Penetrating Radar, 48–78. Hoboken, NJ: John Wiley & Sons, Inc, 2014. http://dx.doi.org/10.1002/9781118835647.ch4.
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Sinharay, Rajib Kumar. "GPR Surveys in Antarctica to Map Ice Thickness and Rock Topography." In Geoscientific Investigations From the Indian Antarctic Program, 121–37. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-6684-4078-0.ch006.
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Ground penetrating radar (GPR) surveys have been carried out at Schirmacher Oasis and Dakshin Gangotri located at Queen Maud Land, East Antarctica, during the 22nd Indian Antarctic Summer Expedition, 2002-2003. The present study confirmed the ability of the high-resolution GPR for monitoring the glaciers. It gives information about the health of the glaciers before it collapses. GPR survey over three frozen lakes near the Maitri Station provided the lakes' top ice thickness and bedrock depth. Similarly, the internal layers of the glaciers have been mapped in-situ using GPR. The results can be correlated with the results obtained by ice-core drill wells to understand the different field parameters (i.e., thickness of each layer, dielectric constant, etc.).
Тези доповідей конференцій з теми "Dielectric penetration"
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Parent, David W., Janet Davis, and Eric J. Basham. "High-k dielectric fabrication process to minimize mobile ionic penetration." In 2010 32nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2010). IEEE, 2010. http://dx.doi.org/10.1109/iembs.2010.5627801.
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Zouaghi, Ayyoub, and Noureddine Zouzou. "Submicrometer Particle Penetration in a Miniature Dielectric Barrier Discharge type Electrostatic Precipitator." In 2020 IEEE Industry Applications Society Annual Meeting. IEEE, 2020. http://dx.doi.org/10.1109/ias44978.2020.9334854.
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Zhu, Fei, and Weizhong Dai. "Numerical Simulation of Nanopulse Penetration of Biological Matters Using the ADI-FDTD Method." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-86574.
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Study of the nanopulse bioeffects is important to ensure the appropriate application with nanopulse in biomedical and biotechnological settings. In this article, we develop an alternating-direction implicit (ADI) finite-difference time-domain (FDTD) scheme coupled with the Cole-Cole expression for dielectric coefficients of biological tissues to simulate the electromagnetic fields inside the biological tissues when exposed to nanopulses. The scheme is then tested by numerical examples with two different biological tissues. Numerical results show that the proposed ADI-FDTD scheme breaks through the Courant, Friedrichs, and Lewy (CFL) stability condition and provides a stable solution with a larger time step, where the conventional FDTD scheme fails. Results also indicate that the computational time can be reduced when using a larger time step.
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Bogdanov, F. G., G. Sh Kevanishvili, T. B. Kobakhidze, and G. G. Chikhladze. "Wave penetration through and reflection from the combined multilayered many-element gratings with dielectric layer and metal screen." In Proceedings of III International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory. DIPED-98. IEEE, 1998. http://dx.doi.org/10.1109/diped.1998.730953.
Повний текст джерела
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Binghai, Liu, Mo Zhiqiang, Hua Younan, and Teong Jennifer. "Optimization of SEM Analytical Conditions for Low K and Ultra Low K Dielectric Materials." In ISTFA 2008. ASM International, 2008. http://dx.doi.org/10.31399/asm.cp.istfa2008p0291.
Повний текст джерелаАнотація:
Abstract Electron beam induced radiation damage presents great challenges for the electron microscopy analysis of low k and ultra low k dielectrics due to their beam sensitive nature. In order to minimize the radiation damage, it is necessary to understand the mechanisms behind the damage. This work presents detailed studies regarding the mechanisms behind the effects of probe currents, accelerating voltage and anticharging coating layers on the radiation damage to low/ultralow K dielectrics. The results indicate that the probe current shows a stronger dependence on the size of the condenser lens aperture than the accelerating voltage. Therefore, in terms of the probe current, the condenser lens aperture plays a decisive role in affecting the radiation damage process. In order to minimize the radiation damage, SEM imaging should be conducted with not only a low accelerating voltage but also a small condenser lens aperture to reduce probe current. Based on simulation results, the effects of a coating layer and accelerating voltage are related to the interaction volume and the penetration depth of the electron beam. Pt coating can act as not only an anti-charging layer, but also an effective barrier layer for reducing electron flux that interacts with the low/ultra-low dielectrics.
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Burzo, Mihai G., Pavel L. Komarov, and Peter E. Raad. "A Study of the Effect of Surface Metalization on the Thermal Conductivity Measurements by the Transient Thermo-Reflectance Method." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-32761.
Повний текст джерелаАнотація:
This work is a numerical and experimental investigation of the effect of the use of a metallic absorption layer on the laser-based measurements of the thermal conductivity of dielectric, semiconductor, and highly-conductive materials. The numerical and supporting experimental results reveal the presence of behaviors associated with thermally-thin and thermally-thick absorption layers, depending on the ratio between the thickness of the absorption layer and the heat penetration depth. It is concluded that the TTR method performs optimally when the thickness of the metalization layer falls in the transition range between the identified thermally-thin and thermally-thick layers.
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Post, Marissa J., J. Liu, J. Du, S. R. Schmid, T. Ovaert, and M. Laurent. "Characterization of Silicon Oxide-Based Materials in an Atomic Force Microscope." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15636.
Повний текст джерелаАнотація:
Silicon oxides are widespread in microelectronics and microelectromechanical systems (MEMS) applications. One form of this material that has been suggested as a dielectric in MEMS applications is a carbon-doped form of silicon oxide that can be produced in thin coatings. However, the mechanical properties and wear resistance of these coatings is unknown, and coatings of interest are difficult to characterize because they are very thin. A test methodology has been previously described using extremely sharp diamond tips on a stainless steel cantilever in an atomic force microscope, and this method allows direct calculation of an effective material flow strength at penetration depths as small as twenty nanometers. A number of forms of carbon-doped and undoped silicon dioxide have been evaluated using this methodology. Size effects on material properties are evaluated, and correlations between test methods are presented.
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Zhu, L., A. Attaluri, N. Manuchehrabadi, H. Cai, R. Edziah, E. Lalanne, C. Bieberich, R. Ma, and A. Johnson. "Temperature Elevations in Implanted Prostatic Tumors During Laser Photothermal Therapy Using Nanorods." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53144.
Повний текст джерелаАнотація:
Gold nanoshells or nanorods are newly developed nanotechnology in laser photothermal therapy for cancer treatments in recent years [1–10]. Gold nanoshells consists of a solid dielectric nanoparticle core (∼100 nm) coated by a thin gold shell (∼10 nm). Gold nanorods have a diameter of 10 nm and an aspect ratio of approximately four. Nanorods may be taken up by tumors more readily than nanoshells due to nanorods’ smaller size. By varying the geometric ratio, both nanoshells and nanorods can be tuned to have strong absorption and scattering to a specific laser wavelength. Among a wide range of laser wavelengths, the near infrared (NIR) laser at ∼800 nm is most attractive to clinicians due to its deep optical penetration in tissue. Therefore, the tissue would appear almost “transparent” to the 800 nm laser light before the laser reaches the nanoshells or nanorods in tumors, with minimal laser energy wasted by the tissue without the nanostructures. The laser energy absorbed in an area congregating by the nanostructures is transferred to the surrounding tissue by heat conduction. This approach not only achieves targeted delivery of laser energy to the tumor, but also maximally concentrates a majority of the laser energy to the tumor region.
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Vaitkus, Audrius, Rita Kleizienė, and Martynas Karbočius. "EFFECT OF DIELECTRIC CONSTANT ON ASPHALT LAYERS THICKNESS BASED ON GROUND PENETRATING RADAR DATA ANALYSIS." In 11th International Conference “Environmental Engineering”. VGTU Technika, 2020. http://dx.doi.org/10.3846/enviro.2020.636.
Повний текст джерелаАнотація:
The ground penetrating radar (GPR) in roads is use to investigate the pavement structure layers thickness on network and project level, misaligned dowels and tie bar in concrete pavement, moisture and ground water level, air voids of asphalt layers, and to assure the quality control. Since, pavement layer thickness and materials properties are the key parameters for pavement bearing capacity and residual life determination the effective and reliable GPR analysis procedure is substantial for pavement management system. However, in order to determine asphalt layers thickness the dielectric constant or GPR velocity have to be known. The most common practice to determine the dielectric constant of specific pavement layer is to drill the cores at least every 1 km, as combination of destructive and non-destructive methods. The objective of this study is to investigate the effect of the dielectric constant to asphalt layers thickness determination accuracy. The dielectric constant of asphalt layers and GPR measurements were performed in the 27th pavement sections of the Test Road. The dielectric constant of asphalt layers calculated based on drilled cores data. Analysing the wearing, binder, and base layers separately and in combination. Finally, the errors of determined thicknesses of pavement layers were compared with actual thickness. To determine the dielectric constant influence to the asphalt layer thickness of road sections were investigated by drilling cores and determined the actual thickness. The dielectric constant based on core data and GPR measurements were compared.
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Sutinen, Raimo, Pekka Hnninen, Rowland Cromwell, and Eija Hyvnen. "GPR and dielectric classification of glacial materials." In Fourth International Conference on Ground Penetrating Radar. European Association of Geoscientists & Engineers, 1992. http://dx.doi.org/10.3997/2214-4609-pdb.303.18.
Повний текст джерелаЗвіти організацій з теми "Dielectric penetration"
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Al-Qadi, Imad, Qingqing Cao, Lama Abufares, Siqi Wang, Uthman Mohamed Ali, and Greg Renshaw. Moisture Content and In-place Density of Cold-Recycling Treatments. Illinois Center for Transportation, May 2022. http://dx.doi.org/10.36501/0197-9191/22-007.
Повний текст джерелаАнотація:
Cold-recycling treatments are gaining popularity in the United States because of their economic and environmental benefits. Curing is the most critical phase for these treatments. Curing is the process where emulsion breaks and water evaporates, leaving residual binder in the treated material. In this process, the cold-recycled mix gains strength. Sufficient strength is required before opening the cold-treated layer to traffic or placing an overlay. Otherwise, premature failure, related to insufficient strength and trapped moisture, would be expected. However, some challenges arise from the lack of relevant information and specifications to monitor treatment curing. This report presents the outcomes of a research project funded by the Illinois Department for Transportation to investigate the feasibility of using the nondestructive ground-penetrating radar (GPR) for density and moisture content estimation of cold-recycled treatments. Monitoring moisture content is an indicator of curing level; treated layers must meet a threshold of maximum allowable moisture content (2% in Illinois) to be considered sufficiently cured. The methodology followed in this report included GPR numerical simulations and GPR indoor and field tests for data sources. The data were used to correlate moisture content to dielectric properties calculated from GPR measurements. Two models were developed for moisture content estimation: the first is based on numerical simulations and the second is based on electromagnetic mixing theory and called the Al-Qadi-Cao-Abufares (ACA) model. The simulation model had an average error of 0.33% for moisture prediction for five different field projects. The ACA model had an average error of 2% for density prediction and an average root-mean-square error of less than 0.5% for moisture content prediction for both indoor and field tests. The ACA model is presented as part of a developed user-friendly tool that could be used in the future to continuously monitor curing of cold-recycled treatments.