858 results on '"high resistivity"'
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2. LONGITUDINAL FRACTURE INFLUENCE ON THE UNFOCUSED LATERAL LOGGING SOUNDING RESPONSES IN HIGH-RESISTIVITY DEPOSITS
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Irina V. Surodina, Karina V. Sukhorukova, Anita A. Lapkovskaya, and Aleksei M. Petrov
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Depth sounding ,High resistivity ,Logging ,Longitudinal fracture ,Seismology ,Geology - Abstract
The article considers the analysis of unfocused lateral logs (BKZ) simulated in three-dimensional media models with a vertical fracture. It was found that for the Tomsk region Upper Paleozoic deposits conditions the influence of a single thin fracture passing through the well axis on the signals is equivalent to the influence of the invaded low resistivity zone. On the practical data measured in the well of Archinskoe oil-gas-condensate field (Tomsk region) we discuss the possibilities of numerical data inversion for identifying oil-productive intervals.
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- 2021
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3. Drain Voltage Dependence Analysis of RF Inductive Effect in Body Contacted High Resistivity PD-SOI N-MOSFETs
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Seonghearn Lee and LeeKiAhn
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Materials science ,High resistivity ,business.industry ,Silicon on insulator ,Optoelectronics ,Voltage dependence ,Soi cmos ,business ,Inductive effect - Published
- 2021
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4. Genesis of bitumen and high resistivity water layer in Yanchang formation, Ordos Basin, China
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Zhenglu Xiao, Shijia Chen, Longxiang Tang, Meimei Han, Zhanxi Chen, and Xiangdong Yin
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Renewable Energy, Sustainability and the Environment ,020209 energy ,Geochemistry ,Energy Engineering and Power Technology ,02 engineering and technology ,Structural basin ,humanities ,Fuel Technology ,High resistivity ,020401 chemical engineering ,Nuclear Energy and Engineering ,Water layer ,Asphalt ,0202 electrical engineering, electronic engineering, information engineering ,0204 chemical engineering ,China ,Geology - Abstract
Many oil-bearing basins in the world have found high-resistivity water layers, which brings difficulties to the identification of oil-water layers and the exploration and development of oil fields....
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- 2021
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5. Ground Electromagnetic and Electric Studies for Um Salim Gold Mine, Central Eastern Desert, Egypt
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Hussein F. Abd El Salam, Ibrahim M. M. Al-Alfy, Mohamed A. El-Sadek, and Mostafa A. M. Zaeimah
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High resistivity ,Electrical resistivity and conductivity ,Drilling ,Mineralogy ,Gold mineralization ,Induced polarization ,Geology - Abstract
Horizontal Loop Electromagnetic (HLEM) and Induced Polarization (IP) methods have been carried out within Um Salim gold mine area. The study area reveals special importance, as it comprises rock units, which show some indication of the presence of various mineralization. The result of HLEM has shown significant and well-defined conductive zones are recorded along with the four used frequencies (110 Hz, 440 Hz, 1760 Hz, and 7040 Hz) at the station 2,782,900 and station 2,782,880 of two (HLEM) profiles (596,050 N & 596,240 N) respectively, that may reflect the sources of the conductive bodies are situated at shallow depths continued to considerable depths. The result of IP exhibits a strong anomalous zone centered at stations 140 and 240, with chargeability values ranging (37 to more than 120 mV/V) on chargeability model section, and corresponding to high resistivity on resistivity model section which may reflect considerable surface and subsurface disseminated mineralization. Through the integration between HLEM and IP a core drilling is recommended at station 140 on IP profile which coincides with station 2,782,850 on HLEM profile (596,240 N) to a depth of concerning 100m take a look at the thickness, depth, and grade of mineralization.
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- 2021
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6. High Resistivity Reservoirs (Causes And Effects): Sahara Field, Murzuq Basin, Libya
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Hammad Janjujah, Abubaker Alansari, Ahmed Mohamed Ahmed Salim, Abdul Hadi Abd Rahman, and Nuri Mohamed Fello
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High resistivity ,Field (physics) ,General Earth and Planetary Sciences ,Structural basin ,Petrology ,Geology ,General Environmental Science - Abstract
High and low resistivity values is an alarming phenomenon that is usually associated with a very complicated reservoir history and worth looking into. Ordovician sandstone reservoirs are the primary oil producers in the Murzuq basin oil fields that is characterized with an average porosity of 14%, permeability range 410-10,760 md and clean quartz aranite composition. More than fifty wells were drilled in Sahara oil field, but only four of them were announced to have high resistivity values more than 100k ohm-m and ten others to be considered as low resistivity wells (below 50 ohm-m). Therefore, average deep resistivity was mapped in both water and oil legs using all available data set, and the top reservoir was employed as a trend map. They showed distinctive trends for low resistivity readings in oil-leg and confirmed the extreme deep resistivity nature for the wells (W7, W8, W9, and W10). Height above oil water contact and capillary pressure was also calculated for all the wells and revealed a high pressure (400 psi) at the location of the high resistivity wells. As a result, of higher capillary pressure in thicker reservoir area oil might have been able to displace water through geological time by benefitting of more considerable height above oil-water contact, higher connate pressure, and buoyancy forces support, which resulted in occupying all the larger pores and pushed the water into minor scattered pores leading to gradual alteration of reservoir wettability from water to oil-wet. Hence, the brine fluids will no longer be connected to each other inside the pore system. Therefore, they will lose their contribution to resistivity readings, and the resistivity tool will encounter a more resistant medium, which in turn will lead to underestimation of water saturation.
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- 2020
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7. Sn doped ZnO thin films as high resistivity window layer for Cu(In,Ga)Se2 solar cells
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Niu Jian-wen, MA Rui-xin, and LI Shi-na
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Materials science ,business.industry ,Doping ,02 engineering and technology ,Condensed Matter Physics ,Laser ,01 natural sciences ,Copper indium gallium selenide solar cells ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,010309 optics ,020210 optoelectronics & photonics ,High resistivity ,law ,0103 physical sciences ,Solar cell ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,Electrical and Electronic Engineering ,Thin film ,Photonics ,business ,Layer (electronics) - Abstract
For high efficiency Cu(In,Ga)Se2 (CIGS) solar cell, the high-resistivity layer with high optical transmittance has to be adopted between the buffer layer and the high-conductivity window layer. In this paper, we propose Sn doped ZnO (ZTO) film, instead of the traditional intrinsic ZnO (i-ZnO) film, as an alternative n-type high-resistivity window layer for CIGS solar cell. In this experiment, both ZTO and i-ZnO films are strong (002) oriented, and the surface morphologies of the two films are almost the same. The statistical roughnesses of i-ZnO film and ZTO film are 0.58 nm and 0.63 nm, respectively. However, the optical transmittance of ZTO film is higher than that of i-ZnO film with the same thickness. The efficiency of ZTO based CIGS cell was 14.24%, which is almost the same as the efficiency of i-ZnO based CIGS cell. These results fully suggest that it is very feasible to replace i-ZnO with ZTO as the high resistant window layer.
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- 2020
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8. DC characterization of isoparaffinic insulation oil
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Nils Lavesson, Joachim Schiessling, and Lars Walfridsson
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010302 applied physics ,Pressboard ,Resistive touchscreen ,Materials science ,Petroleum engineering ,Dielectric ,01 natural sciences ,law.invention ,Gas to liquids ,High resistivity ,Electrical resistivity and conductivity ,law ,0103 physical sciences ,medicine ,Electrical and Electronic Engineering ,Mineral oil ,Transformer ,medicine.drug - Abstract
Converter transformers in HVDC stations are subject to both AC and DC stresses. With new oils entering the market it is important that these are characterized both for AC and DC. This paper focuses on DC characterization of one such oil, which is an isoparaffinic oil produced using a gas to liquid production process. The results are compared to mineral oil as reference. The isoparaffinic oil is shown to have a very high resistivity. In fact, the resistivity is so high that it is more resistive than impregnated pressboard with low moisture content. This is a dielectric risk which must be considered if the oil is to be used in converter transformers.
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- 2020
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9. Solution to the Problem of Precipitation of High-Resistivity Ashes by Electrostatic Precipitators
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L. V. Chekalov, V. A. Guzaev, and M. E. Smirnov
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Flue gas ,High resistivity ,Precipitation (chemistry) ,Electrostatic precipitation ,Environmental engineering ,Energy Engineering and Power Technology ,Electrostatic precipitator ,Environmental science ,Particle drift ,Bag filter ,Coal power plant - Abstract
The innovative and highly effective Russian electrostatic precipitators of the EGAV type were created in order to solve problems associated with the reduction of ash emissions at coal power plants. The new electrostatic precipitators ensured an increase in precipitation effectiveness to 99.87% in the same overall housing sizes along with a reduction in emissions up to 16 times, with actual emissions ranging from 12.6 to 119 mg/m3 (under standard conditions). The technical solutions for intensifying electrostatic precipitation realised in EGAV precipitators increase particle drift velocity to the precipitating electrode by 65%. The application of the EGAV type electrostatic precipitators for removing high-resistivity ashes from flue gases led to the required reduction of emissions during the modernization of the acting electrostatic precipitators. The cost of reconstructing the gas-cleaning unit with the application of innovative electrostatic precipitators turned to be less than with the use of a combined electrostatic precipitator or a bag filter. The new electrical cleaning technology also formed a scientific basis for the innovative development of other promising gas-cleaning technologies.
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- 2020
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10. INTERPRETASI GEOFISIKA BIDANG GELINCIR PALEO-ROCKSLIDE PARANGTRITIS
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Suharno Suharno, Hesti Hesti, Bella Restu Juliarka, Rahmi Mulyasari, and Akroma Hidayatika
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QE1-996.5 ,geography ,geography.geographical_feature_category ,Andesite ,Geology ,Slip (materials science) ,audio-magnetotelluric ,Sand dune stabilization ,paleo-rockslide ,Rockfall ,High resistivity ,Electrical resistivity and conductivity ,Breccia ,parangtritis ,sliding plane ,Rock mass classification ,Geomorphology - Abstract
Parangtritis has a rock fall hazard area with a medium to high level of risk. In Parangtritis, there was a large scale paleo-rockslide that involved more than 800 million m3 of rock mass with an area of 1500 m x 2700 m. This is a significant factor in changing the landscape. This research uses 9 Audio-MagnetoTelluric (AMT) primary data points. Using the distance between points 750 m within a 2 km x 2 km study area. The location focused on the western side of the paleo-landslide area in Parangtritis Village. Processing AMT data using the help of MT-INV and RockWorks software. The result of one-dimensional inversion consists of 3 layers. Indicates a low resistivity value (0-10 Ωm) interpreted as beach deposition and sand dune, medium resistivity (50 - 160 Ωm) for Wonosari limestone and high resistivity ( 170 Ωm) for Nglanggran andesite breccias. The average thickness of the first layer is 44 m and the second layer reaches 175 m. Based on the resistivity structure of the AMT data, the interpretation of the boundary contact between the Wonosari limestone and the Nglanggran andesite breccia can act as a slip field in a depth of about 250 m This field is a passive fault field controlled by the Girijati fault in the east of the study area.
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- 2020
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11. High-Resistivity Transition-Edge Sensor Modeling and Expected Performances
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Galahad Jego, X. F. Navick, Xavier Coppolani, Xavier de la Broïse, S. Marnieros, and Jean-Luc Sauvageot
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Pixel ,Physics::Instrumentation and Detectors ,Computer science ,Detector ,Astrophysics::Instrumentation and Methods for Astrophysics ,Cryogenics ,Cryocooler ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010305 fluids & plasmas ,High resistivity ,0103 physical sciences ,Electronic engineering ,General Materials Science ,Stage (hydrology) ,Spectral resolution ,Transition edge sensor ,010306 general physics - Abstract
High spectral resolution detectors based on low-resistivity transition-edge sensors (TES) are being developed for future X-ray spatial observatories, but difficulties (cryogenics limitations) are to be expected in next generation’s detectors with even more pixels. A new technology, the high-resistivity TES (HRTES), is likely to offer similar performance to existing TES when associated to an active electrothermal feedback, adding the possibility of moving the readout electronics to a 2.5 K stage of the cryocooler. This work aims to investigate HRTES by making a precise model of the device, comparing it to experimental measurements, and deducing its performance potential.
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- 2020
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12. Reconstructing salt geometry using 3D CSEM data
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Martin Panzner, Humberto Salazar Soto, and Luis Alberto Sanchez Perez
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Geophysics ,High resistivity ,Electrical resistivity and conductivity ,Inversion (meteorology) ,Geometry ,Seismic interpretation ,010502 geochemistry & geophysics ,01 natural sciences ,Model building ,Synthetic data ,Geology ,0105 earth and related environmental sciences ,Controlled source - Abstract
In this paper we demonstrate the imaging capabilities of a newly developed 3D Gauss-Newton inversion algorithm for marine controlled source electromagnetic (CSEM) data by inverting synthetic data generated from a known salt resistivity model. We show that the high resistivity contrast between salt and background sediments can be utilized to reconstruct reliable images of the salt structure without the use of any a-priori information which could bias the outcome. Further, we re-invert a CSEM data set acquired in 2012 in the Salina basin in the Gulf of Mexico, using the same 3D Gauss-Newton inversion algorithm. The resulting resistivity model is compared to the initial salt interpretation based on seismic data. The top salt boundary in the inverted resistivity model correlates well with the initial interpretation. However, the base salt geometry, which is often difficult to map with seismic data alone, is imaged very differently. The CSEM inversion result is robust and independent of other geophysical data and therefore very valuable in a salt imaging workflow to support seismic interpretation and velocity model building.
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- 2020
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13. High-resistivity p-type silicon-based p-i-n photodiode with high responsivity at the wavelength of 1060 nm
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M. S. Kukurudziak, O. P. Andreeva, and V. M. Lipka
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Materials science ,business.industry ,silicon ,P type silicon ,sensitivity ,TK1-9971 ,Photodiode ,law.invention ,Wavelength ,Responsivity ,High resistivity ,law ,technological mode ,Optoelectronics ,photodiode ,Electrical engineering. Electronics. Nuclear engineering ,business - Abstract
The paper presents the results of development, optimization and improvement of p–i–n photodiode technology based on high-resistance p-type silicon with increased responsivity at a wavelength of 1060 nm. The optimal material was selected and the technological modes optimal for solving the set task were established and worked out іn the course of research.
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- 2020
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14. Identification of Mineral Potential in Galang District Tolitoli Regency Using the Method of Resistance and Induced Polarization
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Nur Hidayat, Adya Nur Syafitri Wijaya, and Tati Zera
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Igneous rock ,High resistivity ,Andesite ,Metamorphic rock ,Geochemistry ,General Earth and Planetary Sciences ,Sedimentary rock ,Mineral potential ,Mineral resource classification ,Induced polarization ,Geology ,General Environmental Science - Abstract
Geologically, the province of Central Sulawesi is composed of various types of rocks, both in the form of igneous, sedimentary and metamorphic rocks. Regarding Central Sulawesi Province, mineral resources both metal and non-metal are quite varied. Increasing demand and demand for minerals, both metals, and non-metals. Research conducted to study the mineral potential in one of the regencies in Central Sulawesi Province. This research was conducted in Galang Sub-district, Tolitoli Regency, and Central Sulawesi Province by using the resistivity method and the Induced Polarization (IP) method with the Wenner-Schlumberger arrangement consisting of eight lines. The IP method is very accurate to discuss the potential of minerals that are below the surface. The inversion process does data processing in order to obtain the actual form of resistivity and chargeability modeling. Based on the modeling, the mineral potential in Galang Sub-district, Tolitoli Regency, Central Sulawesi Province is mostly found in all trajectories namely lane 01; 02; 04; 05; 05; 06; 07. Which is marked by a very high chargeability value between 300 msec - 500 msec. The research area also discusses granite and andesite, which have high resistivity values, between 2000 Ωm – 400000 Ωm.
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- 2019
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15. High-Resistivity Gallium Antimonide Produced by Metal–Organic Vapor-Phase Epitaxy
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Alexander N. Smirnov, R. V. Levin, B. V. Pushnyi, and A. S. Vlasov
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010302 applied physics ,Materials science ,Analytical chemistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Epitaxy ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Organic vapor ,Electronic, Optical and Magnetic Materials ,Crystal ,Metal ,Gallium antimonide ,chemistry.chemical_compound ,High resistivity ,chemistry ,Electrical resistivity and conductivity ,visual_art ,Phase (matter) ,0103 physical sciences ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
The results of studies of nominally undoped epitaxial p-GaSb layers grown by metal–organic vapor-phase epitaxy at a ratio TMSb/TEGa in the range from 1 to 50 are reported. At the ratio TMSb/TEGa = 50, GaSb epitaxial layers, whose resistivity is 400 Ω cm, are produced. It is shown that, for such layers, the crystal quality assessed by several methods remains comparable to the quality of n-GaSb substrates used for the growth of nominally undoped GaSb layers.
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- 2019
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16. Microstructuring of the Surface of High-Resistivity Single-Crystalline Silicon by Chemical Etching
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M. R. Lakmanova, A. V. Pogozheva, E. V. Permikina, A. S. Kashuba, and Sergey V. Golovin
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Radiation ,Anisotropic etching ,Materials science ,Silicon ,fungi ,technology, industry, and agriculture ,chemistry.chemical_element ,macromolecular substances ,Electrolyte ,Condensed Matter Physics ,Isotropic etching ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,High resistivity ,stomatognathic system ,chemistry ,Chemical engineering ,Etching (microfabrication) ,Crystalline silicon ,Electrical and Electronic Engineering ,Hydrogen peroxide - Abstract
The influence of various etching processes on the single-crystalline (100) silicon surface is studied. It is demonstrated that microstructuring of the surface of high-resistivity single-crystalline silicon in alkaline solutions is better performed using electrolytic methods at temperatures no lower than 80°C. Etch patterns with better-defined side faces are formed by anisotropic etching with the addition of hydrogen peroxide.
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- 2019
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17. In-situ synthesis and magnetic properties of core-shell structured Fe/Fe3O4 composites
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Qian Zhang, Kun Peng, and Wei Zhang
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010302 applied physics ,In situ ,Materials science ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Core shell ,Magnetization ,Insulation layer ,High resistivity ,Ferrimagnetism ,Permeability (electromagnetism) ,0103 physical sciences ,Composite material ,0210 nano-technology ,Control methods - Abstract
Fe/Fe3O4 core-shell structure soft magnetic composites were synthesized by in-situ oxidation method, the shell thickness control method and its effect on magnetic properties was investigated. The formation of Fe3O4 shell will decrease eddy-current loss for its high resistivity but reduce the permeability and saturation magnetization for its ferrimagnetic characteristics, appropriate shell thickness is the key factor to obtain a good performance of composites. The magnetic loss decreased dramatically due to the existence of a dense insulation layer and increased slightly owing to the presence of cracks in the insulation layer with the shell thickness increase further. The optimum magnetic properties of the composites were obtained for the composites with about 0.17 μm shell thickness, which exhibits a high permeability (μ) of 55, a high magnetization of 232.1 emu/g at 1 T and a low magnetic loss (W) of 30.56 w/kg at 20 mT and 100 kHz.
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- 2019
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18. Effect of high-resistivity ground on the lightning performance of overhead lines
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José Osvaldo Saldanha Paulino and Celio Fonseca Barbosa
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Physics ,High resistivity ,Monte carlo code ,020209 energy ,020208 electrical & electronic engineering ,0202 electrical engineering, electronic engineering, information engineering ,Energy Engineering and Power Technology ,Overhead (computing) ,Ground and neutral ,02 engineering and technology ,Electrical and Electronic Engineering ,Lightning ,Computational physics - Abstract
This paper presents an approximate formula for the peak-value of the lightning overvoltages induced on aerial lines installed over high resistivity ground, which is valid up to 10 kΩ m. The formula is validated by comparing its results with results obtained from more accurate techniques. The formula is then applied in a Monte Carlo code to assess the effect of high-resistivity ground on the lightning performance of distribution lines without grounded neutral conductor. The results show that, for good conducting ground (e.g., 100 Ω m), indirect flashes are relevant for the 100 kV CFO lines, but they are not relevant for the 170 kV CFO lines. For poorly-conducting ground (e.g., 1000 Ω m), indirect flashes are relevant for 170 kV CFO lines, but they are not relevant for the 300 kV CFO lines. Indirect flashes become relevant for the 300 kV CFO lines only for very poor-conducting ground (e.g., above 2000 Ω m). The paper results also show that using a grounded neutral conductor improves significantly the indirect lightning performance of distribution lines.
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- 2019
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19. The use of Electrical Resistivity Tomography for Soil Sinking Investigation a case study in Satellite Town Langerpura Sub Himalaya Azad Jammu and Kashmir Pakistan
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S. J. A. S. Kazmi, S. Z. A. Gurdazi, J. Niaz, Abrar Niaz, and J. Khan
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geography ,High resistivity ,geography.geographical_feature_category ,Soil test ,Electrical resistivity and conductivity ,Compaction ,Borehole ,Soil science ,Electrical resistivity tomography ,Muck ,Geology ,Sink (geography) - Abstract
Soil sinking is a major engineering concern need to be addressed through proper planning and investigation. Usually Engineers depend on borehole data or soil tests for designing the solution for such problems. In view of cost, time and less destruction, geophysical methods are best to probe such engineering and environmental problems. Therefore, Electrical resistivity tomography (ERT) method used to investigate soil sinking in Satellite town Langerpura, Sub Himalayas Azad Jammu and Kashmir Muzaffarabad Pakistan. Two profiles acquired overlap the zone under study with electrode spacing 5m and average depth of 40-50m. Three different geological zones are identified on the base of resistivity data. Low resistivity zone having resistivity 3.0 – 15Ωm is water saturated friable sandstone. Intermediate resistivity zone with resistivity range 100-1000 Ωm consists of alternate layers of sand, clay and river deposits. High resistivity zone with resistivity range 1000-4000 Ωm show cavities in subsurface. The room size cavity detected which cause the soil sinking at surface. Muck filling or compaction grouting recommended as engineering solution for stabilization of sink soil.
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- 2019
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20. Core–shell NTC materials with low thermal constant and high resistivity for wide‐temperature thermistor ceramics
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Ting Liu, Hui Jiang, Huimin Zhang, Panfei Ma, and Aimin Chang
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Core shell ,High resistivity ,Materials science ,visual_art ,Thermistor ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Ceramic ,Composite material ,Ceramic matrix composite ,Thermal constant - Published
- 2019
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21. Intrinsic and complex defect engineering of quasi-one-dimensional ribbons Sb2S3 for photovoltaics performance
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Xiuli Yang, Hongliang Shi, Mao-Hua Du, and Rumeng Zhao
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Materials science ,Physics and Astronomy (miscellaneous) ,Band gap ,Fermi level ,Defect engineering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Acceptor ,Hybrid functional ,Crystallography ,symbols.namesake ,High resistivity ,0103 physical sciences ,symbols ,General Materials Science ,Quasi one dimensional ,010306 general physics ,0210 nano-technology ,Transient spectroscopy - Abstract
${\mathrm{Sb}}_{2}{\mathrm{S}}_{3}$ has attracted great attention recently as a prospective solar cell absorber material. In this work, intrinsic defects, dopants, and their complexes in ${\mathrm{Sb}}_{2}{\mathrm{S}}_{3}$ are systematically investigated by using hybrid functional theory. ${\mathrm{V}}_{\mathrm{Sb}}$ and ${\mathrm{V}}_{\mathrm{S}}$ are dominant native defects and pin the Fermi level near the midgap, which is consistent with the high resistivity observed experimentally. Both ${\mathrm{V}}_{\mathrm{Sb}}$ and ${\mathrm{V}}_{\mathrm{S}}$ introduce deep levels inside the band gap, which can trap free carriers. Our calculated deep transition levels of ${\mathrm{V}}_{\mathrm{Sb}}$ and ${\mathrm{Sb}}_{\mathrm{S}}$ are consistent well with the results of the deep-level transient spectroscopy measurement. We further study dopants (including Cu, Ti, Zn, Br, and Cl) in ${\mathrm{Sb}}_{2}{\mathrm{S}}_{3}$ and find that Zn and Br/Cl are shallow acceptors and donors, respectively, which may be used to control the carrier and trap densities in ${\mathrm{Sb}}_{2}{\mathrm{S}}_{3}$. In addition, the defect complexes, i.e., $\mathrm{Cu}{(\mathrm{Zn})}_{\mathrm{Sb}}+{\mathrm{V}}_{\mathrm{S}}$ and $\mathrm{Cl}{(\mathrm{Br})}_{\mathrm{S}}+{\mathrm{V}}_{\mathrm{Sb}}$ are also investigated. The interaction between the donor and acceptor defects makes the defect levels of complexes shallower and less detrimental to carrier transport.
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- 2021
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22. Defect Physics of Ternary Semiconductor ZnGeP2 with a High Density of Anion-Cation Antisites: A First-Principles Study
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Menglin Huang, Shanshan Wang, Yu-Ning Wu, and Shiyou Chen
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Physics ,business.industry ,General Physics and Astronomy ,High density ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Spectral line ,Ion ,Condensed Matter::Materials Science ,Crystallography ,Semiconductor ,High resistivity ,Vacancy defect ,0103 physical sciences ,Absorption (logic) ,010306 general physics ,0210 nano-technology ,Ternary operation ,business - Abstract
Anion-cation antisite defects usually have low density in the group III-V (e.g., $\mathrm{Ga}\mathrm{N}$) and ${\mathrm{II}\ensuremath{-}\mathrm{IV}\ensuremath{-}\mathrm{V}}_{2}$ (${\mathrm{Zn}\mathrm{Ge}\mathrm{N}}_{2}$, ${\mathrm{Zn}\mathrm{Sn}\mathrm{P}}_{2}$) semiconductors, and thus, have not drawn enough attention in defect studies of ${\mathrm{Zn}\mathrm{Ge}\mathrm{P}}_{2}$ since 1976. However, our first-principles calculations based on a hybrid functional show that the anion-cation antisite defects (${\mathrm{Ge}}_{\mathrm{P}}$ and ${\mathrm{P}}_{\mathrm{Ge}}$) can have very high density (${10}^{17}\ensuremath{-}{10}^{18}\phantom{\rule{0.1em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$), making them the dominant defects in ${\mathrm{Zn}\mathrm{Ge}\mathrm{P}}_{2}$. Their calculated photoluminescence (PL) spectra agree well with the 1.4 and 1.6 eV PL peaks observed experimentally, indicating that they may be the origin of defects, which challenges previous assumptions that the $\mathrm{P}$ vacancy ($V_{\rm{P}}$) defect is responsible for the two PL peaks. Although the anion-cation antisites (${\mathrm{Ge}}_{\mathrm{P}}$ and ${\mathrm{P}}_{\mathrm{Ge}}$) and cation-cation antisites (${\mathrm{Ge}}_{\mathrm{Zn}}$ and ${\mathrm{Zn}}_{\mathrm{Ge}}$) both have densities as high as ${10}^{17}\phantom{\rule{0.1em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$, ${\mathrm{Zn}\mathrm{Ge}\mathrm{P}}_{2}$ suffers from serious donor-acceptor compensation, which results in a low carrier density (below ${10}^{10}\phantom{\rule{0.1em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$), and thus, poor electrical conductivity. These results explain the mysterious observation that ${\mathrm{Zn}\mathrm{Ge}\mathrm{P}}_{2}$ crystals grown using different methods have a high defect density, but low carrier density and high resistivity, and also indicate that it is challenging to suppress the defect-induced optical absorption in the development of high-power ${\mathrm{Zn}\mathrm{Ge}\mathrm{P}}_{2}$-based optical devices.
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- 2021
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23. Natural molecules against QS-associated biofilm formation of pathogens
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Shunmugiah Karutha Pandian, Thirukannamangai Krishnan Swetha, and Arumugam Priya
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Quorum sensing ,Multicellular organism ,education.field_of_study ,High resistivity ,Antibiotic resistance ,Population ,Biofilm ,Virulence ,Human pathogen ,Biology ,education ,Cell biology - Abstract
Microbes can no more be perceived as single cell as they could experience temporary multicellular existence through mob psychology or group behaviorism. This group behaviorism is made possible through cell-to-cell communication, which is executed by signaling process called quorum sensing (QS). In general terms, QS signaling is a population- dependent group behaviorism, which triggers the microbes to synthesize, transport, and exchange chemical signals between each other to bring about required phenotypic change in the microbial population against environmental challenges. QS circuitry is a tightly regulated process that monitors the expression of many genes. Biofilm formation is one of the major virulent phenotypes of the microbial system, which is regulated by QS circuits. The ability of microbes to form biofilm has been stated to cause serious implications in clinical settings owing to the high resistivity of biofilm cells to multiple antibiotics. Hence, there is an intense need to probe for alternate treatment strategies that could support the management of antimicrobial resistance and infectious diseases. In this regard, quenching of microbial quorum using natural molecules has evolved as one of the effective alternate strategies. With this setting, this chapter focuses on QS circuitry of most notorious human pathogens, the relevance of QS signaling in biofilm formation and infectious diseases, the role of natural molecules as quorum quenchers, and challenges associated with quorum quencher based therapy.
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- 2021
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24. A Novel Insight on Interface Traps Density (Dit) Extraction in GaN-on-Si MOS-c HEMTs
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R. Gwoziecki, William Vandendaele, A. Krakovinsky, Steve W. Martin, A. G. Viey, Marie-Anne Jaud, Marc Plissonnier, Laura Vauche, R. Modica, Ferdinando Iucolano, F. Gaillard, Jérôme Biscarrat, and C. Le Royer
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Materials science ,Equivalent series resistance ,business.industry ,Extraction (chemistry) ,Doping ,Gate stack ,Temperature measurement ,law.invention ,Capacitor ,High resistivity ,law ,Logic gate ,Optoelectronics ,business - Abstract
This paper aims to investigate the interface traps density (Dit) extraction on MOS gate stacks processed on GaN-on-Si substrates. CGV (Capacitance-Conductance) measurements under different frequencies (f = 1kHz-1MHz) and temperatures (T = 20K-500K) on various Al 2 O 3 /UID-GaN MOS capacitors were carried out. Thorough analysis under dark and UV light compared to TCAD/analytical modeling reveal a strong distributed series resistance under the gate related to the high resistivity of UID-GaN layer. This effect leads to an overestimation of the actual Dit value extracted at high frequencies (> 10kHz). Choosing an adequate doping under the gate (n-type) cancels the series resistance effect and unlocks a reliable extraction through {T/f} dependent CGV measurements.
- Published
- 2020
- Full Text
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25. Treatment of the Vacuum Gap Electrodes in a State of Delayed Breakdown
- Author
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S. A. Onischenko and E. V. Nefedtsev
- Subjects
Electric strength ,Materials science ,High resistivity ,law ,Electrode ,Metal electrodes ,Composite material ,Current (fluid) ,Cathode ,Vacuum gap ,law.invention ,Anode - Abstract
The objects of experimental studies were plane vacuum gaps (VG) with a metal cathode and anode made of a heat-resistant material with high resistivity. In these VG's, it was possible to create conditions that can be described as a state of delayed breakdown and to study temporary changes in the current-voltage characteristics at current levels up to 10−4 A without the risk of spark breakdown of the VG during discharge of its capacity. Morphological changes on the metal electrodes surface in the state of delayed breakdown are studied. The possibility of separate conditioning of the VG electrodes together with a high-resistance electrode was also investigated to increase its short-pulse electrical strength of the first breakdown.
- Published
- 2020
- Full Text
- View/download PDF
26. Granite Exploration by using Electrical Resistivity Imaging (ERI): A Case Study in Johor
- Author
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M. N Zolkepli, Z. Abu Talib, M. S. Wahap, A. Mohd Yasin, K. Z. Mohd Arof, M. F. Zolkepli, Earth Resources, M. S. I. Zaini, M. F. Ishak, J. I. Jaafar Sidek, and Mohamad Hazeem Sidik
- Subjects
Mechanical Engineering ,Materials Science (miscellaneous) ,Borehole ,Soil science ,Industrial and Manufacturing Engineering ,Overburden ,High resistivity ,Mechanics of Materials ,Electrical resistivity and conductivity ,Geophysical survey ,Electrical resistivity tomography ,Electrical and Electronic Engineering ,Geology ,Civil and Structural Engineering - Abstract
Electrical Resistivity Imaging (ERI) is a tool used in near surface geophysical surveys by flowing an electric current through electrodes that were injected into the ground. The usage of electrical resistivity imaging (ERI) method dominated by geophysicist has increased tremendously in geotechnical engineering application owing to the efficiency and effectiveness of the method in term of time, cost and also data coverage. The survey performed with respect to the particular reference to ERI in determining the granite rock underneath the ground. There were seven (7) lines of ERI performed at the study area by using ABEM Terrameter LS 2 set of equipment based on Schlumberger protocol. Six (6) boreholes were also drilled to obtain engineering properties of rock at the study area. In order to develop the relationship between resistivity and engineering properties, a comparison between borehole field test result and the resistivity value were made. Results from the ERI indicated the presence of zones with high resistivity values identified as overburden soil, fractured granite and solid granite. The findings of this study also showed that the electrical resistivity imaging coupled with borehole drillings were applicable tools for the determination of the granite rock underneath the ground via subsurface profiles and such as depth of overburden soil and engineering properties of soil. In conclusion, ERI is a method that does not disturb the structure or the function of the soil which successfully became the best method in exploring the granite rock.
- Published
- 2020
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- View/download PDF
27. Modeling liquid crystal lenses
- Author
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Yu Jen Wang, Oleksandr Sova, Yi-Hsin Lin, and V. Yu. Reshetnyak
- Subjects
Materials science ,business.industry ,Physics::Optics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,law.invention ,Contact lens ,Lens (optics) ,High resistivity ,Optics ,Wide area ,Liquid crystal ,law ,Electrode ,Focal length ,business ,Layer (electronics) - Abstract
Liquid crystal based lenses with variable focal length are of broad interest due to their wide area of applications ranging from techniques to medicine. We present the modeling approaches and results for a couple of tunable liquid crystal based lenses, namely: curved electrode lens, lens with hole patterned electrode and high resistivity layer, lens based on modulated anchoring and contact lens. We also discuss the current challenges associated with the modeling of LC lenses and possible ways to overcome them.
- Published
- 2020
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- View/download PDF
28. Defect structure of high-resistivity CdTe:Cl crystals according to the data of high-resolution x-ray diffractometry
- Author
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Ivan Hutsuliak, O. L. Maslyanchuk, Mykola Solodkyi, Volodymyr Dovganyuk, Yurii Roman, Ruslan Zaplitnyy, Andrii Kuzmin, V. V. Lizunov, I. M. Fodchuk, V. P. Kladko, Vadym Mоlоdkin, and Oleksandr Gudymenko
- Subjects
High resistivity ,Materials science ,Analytical chemistry ,X-ray ,High resolution ,Cadmium telluride photovoltaics - Published
- 2020
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29. Analysis and Application of Water Drive Curve Characteristics of Water-Bearing Gas Reservoirs––Taking B-P Gas Field in the Amu Darya Right Bank Area as an Example
- Author
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Wei Ding, Chunqiu Guo, Muwei Cheng, Pengyu Chen, Yue Zheng, Ji-li Yang, and Haidong Shi
- Subjects
geography ,Bearing (mechanical) ,geography.geographical_feature_category ,Lithology ,Structural basin ,law.invention ,Water saturation ,Natural gas field ,High resistivity ,Terrace (geology) ,law ,Electrical resistivity and conductivity ,Petrology ,Geology - Abstract
The B-P gas field locates on the middle section of Region B on the right bank of the Amu Darya, Turkmenistan. In geological structure, it belongs to central uplift belt of Sandykly of Zarzhu terrace, Amy Darya basin. The higher structure parts produce gas, the lower structure parts produce gas and water and some of the low position wells produce only water. The gas reservoir’s upper parts have high resistivity, low water saturation and a obvious gas reservoir character when the lower parts have low resistivity, high water saturation with a obvious character of water in reservoir which means the gas reservoir is controlled by geological structure mainly. Meanwhile, the whole gas reservoir can be divided into four individual gas-water system based on the gas-water interface and conversion pressure of each well which means this gas reservoir is also controlled by lithology.
- Published
- 2020
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- View/download PDF
30. A brief review on synthesis, properties and applications of ferrites
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Rajesh Kumar Sharma, Nisha Kumari, Satvinder Kour, and Gurpreet Singh
- Subjects
Medical diagnostic ,Materials science ,business.industry ,Synthesis methods ,chemistry.chemical_element ,Solar energy ,Engineering physics ,law.invention ,High resistivity ,chemistry ,law ,Eddy current ,Degree of interest ,Lithium ,business - Abstract
During last few decades, there has been a growing degree of interest in ferrites. The magnetic, electrical, optical and other properties of ferrites gain attention due to their use in various applications such as medical diagnostics, rechargeable lithium batteries, high frequency media, solar energy devices and magnetic fluids. The high resistivity and low eddy currents makes ferrites the better choice over metals. The aim of this review paper consists of an overview on the ferrites, classification of ferrites, synthesis methods, properties and its potential applications in different fields of technology.
- Published
- 2020
- Full Text
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31. Nickel ferrite/Chitosan composite as a RADAR absorbing material on missile: A review and prospective
- Author
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Romie Oktovianus Bura and Maspin Apit
- Subjects
Materials science ,Composite number ,Dielectric ,law.invention ,Chitosan ,chemistry.chemical_compound ,Missile ,High resistivity ,chemistry ,law ,Radar ,Composite material ,Radar-absorbent material ,Nickel ferrite - Abstract
Missiles are usually difficult to attack a land target or a surface ship that is equipped with a RADAR. Therefore, technology needs to be developed on missiles so that they are not detected by enemy RADAR. One of these technologies is the provision of RADAR absorbing material on missiles. Nickel ferrite is a cheap material that has high permeability, high resistivity, and high magnetic saturation, so it can be used as RADAR absorbing material. Chitosan is a biopolymer that is polycationic or possessing lots of positive charges from the nitrogen group. These polycationic properties tend to classify chitosan into dielectric materials. Materials with high dielectric properties will be able to absorb electromagnetic waves. Nickel ferrite and Chitosan are combined to make a cheap composite and has a prospect to be a RADAR absorbing material on missile.
- Published
- 2020
- Full Text
- View/download PDF
32. Empirical Kink Effect Modeling for Body Contacted High Resistivity PD-SOI nMOSFETs
- Author
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LeeKiAhn and Seonghearn Lee
- Subjects
010302 applied physics ,High resistivity ,Materials science ,Condensed matter physics ,Body contact ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Silicon on insulator ,020206 networking & telecommunications ,02 engineering and technology ,01 natural sciences - Published
- 2018
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33. Airborne Geophysics over the Dolly Varden VMS and Low Sulphidation Epithermal Silver Deposits, Northwestern BC, Canada
- Author
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Sean E. Walker, Christopher Campbell, Ben Whiting, Jean M. Legault, Karl Kwan, Carlos Izarra, Geoffrey Plastow, and Robert Van Egmond
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Mineralization (geology) ,Electromagnetics ,010504 meteorology & atmospheric sciences ,Volcanogenic massive sulfide ore deposit ,General Engineering ,Geophysics ,Structural basin ,010502 geochemistry & geophysics ,Natural field ,01 natural sciences ,Extensional definition ,High resistivity ,Base metal ,Geology ,0105 earth and related environmental sciences - Abstract
Results from helicopter VTEM time-domain electromagnetics that include aeromagnetics and gamma ray spectrometrics and later ZTEM natural field helicopter electromagnetics are compared over the Dolly Varden Mine region that hosts both potential VMS Pb-Zn base metal and low sulphidation epithermal silver mineralization, beyond the known vein-type Ag deposits and showings. There are few well-defined discrete targets within the VTEM data set. The magnetic data have defined a network of older fault structures trending NNE, ENE, WNW, and NW. These structures are interpreted to be related to extensional basin formation. Prominent in the radiometrics is a potassium anomaly over the Red Point area, consistent with a quartz-K-feldspar-chlorite-pyrite zone, interpreted as a VMS feeder. ZTEM resistivity and magnetic geophysical anomalies suggest the presence of broad, generally flat lying resistive and magnetic units at depth. At Red Point and along the Tiger-Evindsen Corridor, ZTEM displays moderate to high resistivity and low magnetics, which suggest the presence of strong potassic-silicic alteration, related to low sulphidation epithermal systems. The airborne geophysical results over the Dolly Varden mine region provide valuable insights on the detectability of similar Ag rich Eskay Creek type HS VMS and Brucejack style LS epithermal deposits. The principal VMS deposits seem immune to clear or discrete identification as EM conductors using VTEM, likely due to their Pb-Zn rich/Cu poor mineralogy; whereas, unlike VTEM, the ZTEM seems to clearly define high resistivity regions surrounding the known deposits that would seem to be consistent with their K-Si-altered low sulphidation epithermal origin.
- Published
- 2018
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34. Effect of Al content on magnetic domains of {1 0 0} grains in electrical steels
- Author
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Jae Kwan Kim, Yang Mo Koo, Jaewan Hong, and Hyunseo Choi
- Subjects
010302 applied physics ,Materials science ,Condensed matter physics ,Magnetic domain ,Al content ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Force closure ,Electronic, Optical and Magnetic Materials ,Magnetization ,High resistivity ,Permeability (electromagnetism) ,0103 physical sciences ,0210 nano-technology ,Kerr microscopy - Abstract
Magnetic domains of {1 0 0} grains in electrical steels with 1.85 ≤ Al ≤ 6.54 wt% were observed by magneto-optic Kerr microscopy. The characteristics and motion of magnetic domains were correlated with hysteresis loss, anomalous loss and permeability. As Al contents increased, domain wall energy decreased, so the magnetic domain size of {1 0 0} grains decreased. In steel with Al 6.54 wt%, 90° domain walls appeared, so the complexity of domain structures increased. Addition of Al caused increase in hysteresis loss. Anomalous loss decreased until Al 4.68 wt%, then saturated, despite high resistivity and small domain size. External magnetizing force H → required to induce maximum permeability µmax increased drastically at Al 6.54 wt%. These changes of magnetic properties may be caused by pinning of 90° walls during magnetization. As domain size decreased to form closure domains, the complexity of reorganization of magnetic domains increased, and they were interrupted by pinning 90° walls.
- Published
- 2018
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- View/download PDF
35. Quality factor enhancement techniques for inductor and transformer
- Author
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Neerja Singh, Pallavie Tyagi, Sarnam Singh, and Sunil Pandey
- Subjects
Materials science ,Computer Networks and Communications ,business.industry ,Inductor ,Electronic, Optical and Magnetic Materials ,law.invention ,High resistivity ,law ,Q factor ,RFIC ,Optoelectronics ,Electrical and Electronic Engineering ,Transformer ,business ,Instrumentation - Abstract
Quality factor enhancement for inductor and transformer has been achieved by the techniques such as fabricating the inductor and transformer on a glass substrate having high resistivity and by fabr...
- Published
- 2018
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- View/download PDF
36. Detection of Cavity Using Electrical Resistivity Tomography (ERT) at Patherdih, Jharia Coal Field, Dhanbad, India
- Author
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Partha Pratim Mahato
- Subjects
Ground level ,High resistivity ,Electrical resistivity and conductivity ,Geophysical survey ,Coal field ,Mineralogy ,Survey result ,Electrical resistivity tomography ,Joint (geology) ,Geology - Abstract
Geophysical survey for cavity detection is one of the most common near surface application. The usage of resistivity methods are also very straightforward for the air filled underground voids, which should have theoretically very high resistivity in the ERT image, whereas the water filled cavities have low resistivity in Electrical Resistivity Tomography (ERT) image. Three different geoelectric arrays Wenner, Schlumberger and Dipole-dipole are applied for detecting cavities. The survey results suggest that ERT is a viable geophysical tool for the detection and monitoring of mining voids and other subsurface cavities. The resolution capacity of joint Wenner-Schlumberger, Dipole-dipole array for the detection of cavity is greater than that of the individual one. Using the ERT survey in Patherdih Thana Basti village (Jharia coal field), a number of air filled cavity or water filled mining voids are detected at around 25-30m of below the ground level at different profile distance of 630m profile length along the road that extending S-E to N-W direction.
- Published
- 2018
- Full Text
- View/download PDF
37. Experimental study on electrostatic charges and discharges inside storage silo during loading of polypropylene powders
- Author
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Kwangseok Choi, Teruo Suzuki, and Yuta Endo
- Subjects
Polypropylene ,chemistry.chemical_classification ,Electrostatic discharge ,Materials science ,General Chemical Engineering ,02 engineering and technology ,Polymer ,021001 nanoscience & nanotechnology ,Running time ,law.invention ,chemistry.chemical_compound ,High resistivity ,020401 chemical engineering ,chemistry ,law ,Silo ,0204 chemical engineering ,Composite material ,0210 nano-technology ,Faraday cage - Abstract
As polymer powders have high resistivity, they can easily be charged due to the repeated collision and separation of particles along with particle-wall friction in a pneumatic conveying system. This study experimentally investigated the electrostatic charges and discharges inside a conical-cylindrical silo during the loading of polypropylene (PP, 2–3 mm) powders. The silo was continuously loaded with PP powders at 0.68 kg/s to a total mass of approximately 800 kg. To measure electrostatic charges of the PP powder being loaded into the silo, a Faraday cage with a cover was set at a distance of 50 mm from the center of the loading pipe inside the silo. To observe electrostatic discharges inside the silo, an image-intensifier unit was set on the windowpane of the silo roof. The results show that the charge-to-mass ratio of the loading PP powder remained at a constant value of approximately −12 μC/kg. The ring-shaped light, which is the electrostatic discharge, appeared clearly at the center of the silo approximately 7 s after initial loading. The diameter of the ring-shaped light grew larger as time passed after loading. This was because the diameter of the accumulated PP powders increased in the silo during the running time, meaning that electrostatic discharge occurred between settled PP powders and the grounded metal silo wall. Additionally, the electrostatic discharges during the loading of powder in this study were clearly observed and classified into three kinds of discharges: brush, linear, or broad bulk surface discharges.
- Published
- 2018
- Full Text
- View/download PDF
38. SOI MESFETs on high-resistivity, trap-rich substrates
- Author
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Payam Mehr, Trevor Thornton, Xiong Zhang, William Lepkowski, and Chaojiang Li
- Subjects
010302 applied physics ,Materials science ,business.industry ,Substrate (chemistry) ,Silicon on insulator ,020206 networking & telecommunications ,02 engineering and technology ,Condensed Matter Physics ,Thermal conduction ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Trap (computing) ,High resistivity ,CMOS ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Materials Chemistry ,Optoelectronics ,Electrical and Electronic Engineering ,business - Abstract
The DC and RF characteristics of metal-semiconductor field-effect-transistors (MESFETs) on conventional CMOS silicon-on-insulator (SOI) substrates are compared to nominally identical devices on high-resistivity, trap-rich SOI substrates. While the DC transfer characteristics are statistically identical on either substrate, the maximum available gain at GHz frequencies is enhanced by ∼2 dB when using the trap-rich substrates, with maximum operating frequencies, fmax, that are approximately 5–10% higher. The increased fmax is explained by the reduced substrate conduction at GHz frequencies using a lumped-element, small-signal model.
- Published
- 2018
- Full Text
- View/download PDF
39. Earth Return Admittance Effect on Underground Cable System Modeling
- Author
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Antonio C. S. Lima, Maria Teresa Correia de Barros, and Antonio P. C. Magalhaes
- Subjects
Engineering ,Admittance ,business.industry ,020209 energy ,Acoustics ,Electrical engineering ,Energy Engineering and Power Technology ,02 engineering and technology ,Systems modeling ,Physics::Classical Physics ,Electric power system ,High resistivity ,Excited state ,0202 electrical engineering, electronic engineering, information engineering ,Range (statistics) ,Transient response ,Electrical and Electronic Engineering ,business ,Electrical impedance - Abstract
Typically, in cable system modeling for power system transients studies, the ground return effect is taken into account in the per unit length impedance, its effect on the admittance being neglected. In this paper, the per unit length impedance and admittance matrices for a cable system are established, based on the approach previously presented by the authors for the case of a single insulated cable in a dispersive medium. The presented formulation is derived from a full-wave approach, assuming quasi-TEM propagation which was proved suitable for the frequency range of interest. A comparison of the propagation modes indicates that the inclusion of the ground return admittance affects significantly the ground and intersheath modes in the high frequency range, i.e., above a few kilohertz. Test cases where the different modes are excited are used to analyze the impact of including the ground return admittance in computing the transient response of underground cable systems. The results indicate that this impact increases for high resistivity soils and shorter cables.
- Published
- 2018
- Full Text
- View/download PDF
40. Factors influencing corrosion of metal pipes in soils
- Author
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Nabisab Mujawar Mubarak, Inamuddin, Muhammad Wasim, Shahrukh Shoaib, and Abdullah M. Asiri
- Subjects
chemistry.chemical_classification ,Materials science ,Moisture ,020209 energy ,education ,Metallurgy ,Soil resistivity ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Corrosion ,Metal ,High resistivity ,chemistry ,visual_art ,Soil water ,0202 electrical engineering, electronic engineering, information engineering ,engineering ,visual_art.visual_art_medium ,Environmental Chemistry ,Organic matter ,Cast iron ,0210 nano-technology - Abstract
Deterioration of buried metal pipes due to corrosive soil environment is a major issue worlwide. Although failures of buried pipe due to corrosive soil is an old problem, yet such failures are still uncontrollable even with the application of advanced corrosion protection technologies. Therefore, understanding factors causing corrosion of buried pipes is necessary. This article reviews factors causing corrosion of buried pipes in soils. Factors include moisture content, soil resistivity, pH, dissolved oxygen, temperature and microbial activity. Moreover, we discuss the influence of manufacturing method and the comparison of corrosion behaviour of cast iron, ductile and mild steel pipes. We found that corrosion rate of pipes increases with moisture contents up to the critical moisture value. Although pH affects corrosion, there is no relationship between corrosion and pH and the corrosion rates of buried pipes are inversely proportional to soil resistivity. Soils containing more organic matter show high resistivity. Dissolved oxygen in soil develops differential cell which accelerates corrosion of metallic pipe. Different types of bacteria present in soil develop biofilms on metallic pipes, which deteriorates pipes with time.
- Published
- 2018
- Full Text
- View/download PDF
41. Resolution of well-known resistivity equivalences by inclusion of time-domain induced polarization data
- Author
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Gianluca Fiandaca, Line Meldgaard Madsen, Anders Vest Christiansen, and Esben Auken
- Subjects
Dc resistivity ,0208 environmental biotechnology ,Inverse transform sampling ,Inversion (meteorology) ,02 engineering and technology ,010502 geochemistry & geophysics ,01 natural sciences ,Induced polarization ,020801 environmental engineering ,Computational physics ,Markov chain monte carlo algorithm ,Geophysics ,High resistivity ,Geochemistry and Petrology ,Electrical resistivity and conductivity ,Time domain ,Algorithm ,0105 earth and related environmental sciences ,Mathematics - Abstract
The principle of equivalence is known to cause nonuniqueness in interpretations of direct current (DC) resistivity data. Low- or high-resistivity equivalences arise when a thin geologic layer with a low/high resistivity is embedded in a relative high-/low-resistivity background formation causing strong resistivity-thickness correlations. The equivalences often make it impossible to resolve embedded layers. We found that the equivalence problem could be significantly reduced by combining the DC data with full-decay time-domain induced polarization (IP) measurements. We applied a 1D Markov chain Monte Carlo algorithm to invert synthetic DC data of models with low- and high-resistivity equivalences. By applying this inversion method, it is possible to study the space of equivalent models that have an acceptable fit to the observed data, and to make a full sensitivity analysis of the model parameters. Then, we include a contrast in chargeability into the model, modeled in terms of spectral Cole-Cole IP parameters, and invert the DC and IP data in combination. The results show that the addition of IP data largely resolves the DC equivalences. Furthermore, we present a field example in which DC and IP data were measured on a sand formation with an embedded clay layer known from a borehole drilling. Inversion results show that the DC data alone do not resolve the clay layer due to equivalence problems, but by adding the IP data to the inversion, the layer is resolved.
- Published
- 2018
- Full Text
- View/download PDF
42. Growth and Characterisation of Antiferromagnetic Ni2MnAl Heusler Alloy Films
- Author
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Oliver Whear, David C. Lloyd, Atsufumi Hirohata, K. O'Grady, Gonzalo Vallejo-Fernandez, Andrew James Vick, and Teodor Huminiuc
- Subjects
Materials science ,Spintronics ,Condensed matter physics ,Terahertz radiation ,Doping ,Alloy ,engineering.material ,blocking temperature ,Electronic, Optical and Magnetic Materials ,Chemistry ,Exchange bias ,High resistivity ,Chemistry (miscellaneous) ,exchange bias ,Heusler alloys ,spintronic devices ,Materials Chemistry ,engineering ,Antiferromagnetism ,antiferromagnets ,Thin film ,QD1-999 - Abstract
Recent rapid advancement in antiferromagnetic spintronics paves a new path for efficient computing with THz operation. To date, major studies have been performed with conventional metallic, e.g., Ir-Mn and Pt-Mn, and semiconducting, e.g., CuMnAs, antiferromagnets, which may suffer from their elemental criticality and high resistivity. In order to resolve these obstacles, new antiferromagnetic films are under intense development for device operation above room temperature. Here, we report the structural and magnetic properties of an antiferromagnetic Ni2MnAl Heusler alloy with and without Fe and Co doping in thin film form, which has significant potential for device applications.
- Published
- 2021
- Full Text
- View/download PDF
43. Realization low resistivity of high AlN mole fraction Si-doped AlGaN by suppressing the formation native vacancies
- Author
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F. Liang, J.C. Yang, Y. H. Zhang, Degang Zhao, Ping Chen, and Z. S. Liu
- Subjects
Inorganic Chemistry ,High resistivity ,Materials science ,Electrical resistivity and conductivity ,Materials Chemistry ,Analytical chemistry ,Si doped ,Growth rate ,Condensed Matter Physics ,Mole fraction ,Realization (systems) ,Emission intensity - Abstract
The influence of resistivity for n-AlGaN is investigated by changing Si concentration, growth temperature and growth rate. It is found that the resistivity strongly depended on the growth conditions and it reaches to a small value of 5 × 10−3 Ω cm at the growth temperature of 1040 °C. In addition, it is found that there is a strong correlation between the resistivity and the PL emission intensity of group-III-vacancy–Si (VIII-Si) complexes. It indicates that defect compensation can play a key role in high resistivity of n-AlGaN films.
- Published
- 2021
- Full Text
- View/download PDF
44. Frequency-Dependent Quality Factor Modeling of High Resistivity SOI RF CMOS Inductor
- Author
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Seonghearn Lee and Changjo Lee
- Subjects
High resistivity ,Materials science ,Quality (physics) ,CMOS ,business.industry ,Optoelectronics ,Silicon on insulator ,business ,Inductor - Published
- 2017
- Full Text
- View/download PDF
45. Mapping fluids to subduction megathrust locking and slip behavior
- Author
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Demian M. Saffer
- Subjects
010504 meteorology & atmospheric sciences ,Subduction ,Thrust ,Slip (materials science) ,Aseismic creep ,010502 geochemistry & geophysics ,01 natural sciences ,Pore water pressure ,Geophysics ,High resistivity ,Magnetotellurics ,General Earth and Planetary Sciences ,Episodic tremor and slip ,Geology ,Seismology ,0105 earth and related environmental sciences - Abstract
In subduction zones, high fluid content and pore pressure are thought to promote aseismic creep, whereas well-drained conditions are thought to promote locking and failure in earthquakes. However, observations directly linking fluid content and seismic coupling remain elusive. Heise et al. [2017] use a magnetotelluric survey to image the electrical resistivity structure of the northern Hikurangi subduction thrust to ~30 km depth, as an indicator of interconnected fluid content. The authors document a clear correlation between high resistivity and a distinct geodetically locked patch, and between conductive areas and weak coupling. Their study, together with other recent geophysical investigations, provides new evidence for the role of fluids in governing subduction thrust locking.
- Published
- 2017
- Full Text
- View/download PDF
46. Abandoned mine galleries detection using electrical resistivity tomography method over Jharia coal field, India
- Author
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Prasenjit Das, Sanjit Kumar Pal, Piyush Priyam, P. R. Mohanty, Abhay Kumar Bharti, and Rajwardhan Kumar
- Subjects
Hydrogeology ,business.industry ,Model study ,Coal mining ,Geology ,010501 environmental sciences ,010502 geochemistry & geophysics ,01 natural sciences ,High resistivity ,Mining engineering ,Random noise ,Coal field ,Local environment ,Electrical resistivity tomography ,business ,0105 earth and related environmental sciences - Abstract
Land subsidence is a serious problem in Indian coalfields due to old underground mine workings. Unfortunately, most of these are uncharted as no mine plans are available. The hidden galleries, goafs, shafts etc. may pose great threat for future mine development as well as to the local environment. The mine workings should be charted to undertake an effective preventive action. In the present study, 2D electrical resistivity tomography (ERT) technique has been used to detect underground mine workings, mainly air or water filled galleries. Initially, the whole exercise has been executed through a synthetic model study. Gaussian random noise of 5mV/A has been added with synthetic data to demonstrate field condition which provides realistic results. ERT survey was conducted over a part of Jogidih coal mine of Jharia coal field in India for a first time. Four electrode configurations, Wenner, Schlumberger, dipole-dipole and gradient were considered for this study. The results indicate the presence of sub-surface water and air filled cavity due to high resistivity contrast with surroundings.
- Published
- 2017
- Full Text
- View/download PDF
47. Electric behavior of conductor systems embedded in finite inhomogeneous volumes scattered into a multilayered soil: The problem of High-Resistivity Ratios revisited
- Author
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G. Denche, Eduardo Faleiro, Gabriel Asensio, and Jose Ignacio Moreno
- Subjects
Surface (mathematics) ,Materials science ,020209 energy ,Absolute electrode potential ,Energy Engineering and Power Technology ,02 engineering and technology ,Mechanics ,Impedance parameters ,Grid ,01 natural sciences ,Conductor ,010101 applied mathematics ,High resistivity ,Volume (thermodynamics) ,Electrode ,0202 electrical engineering, electronic engineering, information engineering ,Geotechnical engineering ,0101 mathematics ,Electrical and Electronic Engineering - Abstract
The problem of finding the absolute potential and grounding resistance of an electrode system in a multilayered soil is dealt in this paper. Some of the electrodes may be embedded in finite inhomogeneous volumes scattered into the soil. Furthermore, the electrodes may or may not be interconnected. A semi-analytic method is proposed, which is applied to the study of the electrical properties of a ground electrode connected to a metallic grid which is embedded into a cubic volume made of concrete. This volume may be buried in the soil or lying above the ground surface. The problem of high resistivity ratios between the volume and the surroundings is addressed. The paper focuses on the ill-conditioning of the system impedance matrix, resulting in inaccurate numerical solutions of the problem. A procedure will be suggested in order to obtain acceptable solutions in some cases, without increasing the computational cost.
- Published
- 2017
- Full Text
- View/download PDF
48. Laboratory modeling and measurement of the electrical resistivity of hydrate-bearing sand samples
- Author
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A. Yu. Manakov, N.A. Manchenko, A.D. Duchkov, A. N. Drobchik, M. E. Permyakov, and A.K. Manshtein
- Subjects
Bearing (mechanical) ,Aqueous solution ,010504 meteorology & atmospheric sciences ,Analytical chemistry ,Mineralogy ,Geology ,010502 geochemistry & geophysics ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Geophysics ,High resistivity ,chemistry ,law ,Electrical resistivity and conductivity ,Ohm ,Hydrate ,Tetrahydrofuran ,0105 earth and related environmental sciences - Abstract
In this paper, we describe a setup for modeling hydrate-bearing rock samples and measuring their electrical resistivity at different pressures and temperatures using an AMNB cylindrical four-electrode probe. Methods for modeling hydrate-bearing rock samples and measuring their resistivity are considered. The setup was used in a series of experiments to measure the resistivity of sand samples containing water, ice or tetrahydrofuran (THF) hydrate. It is shown that when the rock pores contain hydrates and a partially unfrozen aqueous solution of NaCl and THF, the electrical resistivity is determined by the high resistivity of the solution and increases with the formation of hydrate. The presence of THF hydrate in the experimental samples increased their resistivity by 180–320 Ohm·m at a temperature of about 0 °C. After the formation of hydrate and freezing of residual water, the resistivity of the sample is stabilized at 70–80 Ohm·m at a temperature of -15 °C.
- Published
- 2017
- Full Text
- View/download PDF
49. Evaluation of 2D resistivity imaging technique for delineating subsurface seepage of hydrocarbon-contaminated water southeast of Karbala city, Iraq
- Author
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Jassim M. Thabit and Firas H. AL-Menshed
- Subjects
0301 basic medicine ,Health, Toxicology and Mutagenesis ,030106 microbiology ,Soil science ,010502 geochemistry & geophysics ,01 natural sciences ,03 medical and health sciences ,High resistivity ,Electrical resistivity and conductivity ,Electric Impedance ,Electrochemistry ,Water Movements ,Environmental Chemistry ,Cities ,Transect ,Electrodes ,Groundwater ,0105 earth and related environmental sciences ,Hydrology ,Dry zone ,General Medicine ,Pollution ,Hydrocarbons ,Contaminated water ,Iraq ,Imaging technique ,Water Pollutants, Chemical ,Geology ,Environmental Monitoring - Abstract
2D imaging technique was applied in (8) transects near a pit of contaminated water near contaminated well southeast of Karbala city, Iraq. Each transect was 30 m long with 1 m electrode spacing. Data acquisition was fulfilled by using Wenner electrode array. The resistivity of water-contaminated zone is found less than 3Ω.m and the top dry zone recorded relatively high resistivity (more than 170Ω.m). It is found that the greatest amount of seepage was found moving towards northeast direction coincided with groundwater movement direction, whereas there was no movement towards northwest and southeast directions and restricted on the closest areas to the pit location. The outcomes suggested that the 2D imaging technique is a successful and powerful tool in separating contaminated zone from clear one and in detecting underground seepage depth and moving direction.
- Published
- 2017
- Full Text
- View/download PDF
50. Rectifiers, MOS Diodes and LEDs Made of Fully Porous GaN Produced by Chemical Vapor Deposition
- Author
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Francesc Díaz, Josue Mena, Magdalena Aguiló, Jordi Aixart, Colm O'Dwyer, Joan J. Carvajal, Física i Cristal.lografia de Materials, Física i Cristal·lografia de Nanomaterials, Química Física i Inorgànica, and Universitat Rovira i Virgili
- Subjects
Materials science ,Dielectric interlayers ,Turn-on voltages ,2162-8769 ,02 engineering and technology ,Chemical vapor deposition ,Metallic alloys ,01 natural sciences ,Leakage currents ,GaN ,law.invention ,High resistivity ,law ,P-n junction ,0103 physical sciences ,Magnesium compounds ,Deposition ,Díodes electroluminescents ,Diode ,010302 applied physics ,LED ,Gallium compounds ,Electric rectifiers ,Gallium alloys ,Gallium nitride ,Química ,Binary alloys ,Semiconductor junctions ,021001 nanoscience & nanotechnology ,Diodes ,Vapor deposition ,Engineering physics ,Light emitting diodes ,Electronic, Optical and Magnetic Materials ,Metallic alloy ,Chemistry ,Chemical vapor depositions (CVD) ,Magnesium alloys ,Wide band gap ,Growth steps ,Nitrur de gal·li ,0210 nano-technology ,Porosity ,MOS Diodes ,Light-emitting diode - Abstract
Here we present the fabrication of LEDs based on porous GaN produced by chemical vapor deposition (CVD) and reviewed the work done that allowed demonstrating p-n junction rectifiers and MOS diodes in a simple manner and without involving post-growth steps to induce porosity. p-n junction rectifiers exhibited stable rectification in the range ±1–±5 V, with very stable values of current with time. MOS diodes were fabricated in a single growth step formed by a MgO dielectric interlayer in between Mg-doped porous GaN and a Mg-Ga metallic alloy. Despite the high resistivity observed in the LEDs fabricated, that induced a turn on voltage of ∼13 V, the emission consisted only in one peak centered at 542 nm. Our porous GaN films exhibit random porosity when compared to arrays of nanostructures, however, their easy deposition over large areas without dominating leakage currents is promising for wideband gap applications.
- Published
- 2017
- Full Text
- View/download PDF
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