Search

– The final result of the project is to create a 2D model of the mine plan based on the results of the geophysical measurements. – ERT was chosen as the primary method in this project due to the fact that the voids and the air have a very high resistivity (3,3 ∙ 1016Ωm). Voids are very well recognizable on the ERT results. – Using of the Seismic Refraction Tomography (SRT) is planned on some profiles. SRT is the method rarely used in archaeogeophysical research.

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.

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....

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.

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.

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.

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.

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.

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.

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.

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.

This article analyzes the performance of pinned photodiode (PPD) for Time-of-Flight(ToF) applications on high resistivity epitaxial wafers. Due to its wide depletion region, high epitaxial resistivity PPDs feature some key advantages in collecting photogenerated charges. This article compares the demodulation contrast of the same pixel design on epitaxial wafers with different resistivity at near-infrared wavelength to analyze their performance. By comparing the simulated profile of pixels with different epitaxial resistivity, the characteristics of the PPD pixel on high resistivity epitaxial wafer when collecting photogenerated charges are concluded. This article also discusses the effects of using high resistivity epitaxial wafer with various design parameters. It is found that the use of high resistivity epitaxial wafer can greatly improve crosstalk performance, allow pixels to work at higher modulation frequencies, and enable large-sized pixels to have good demodulation capabilities.

The research had been performed using Magnetotelluric to get a 2D model based on variations in resistivity of the subsurface rock. The purpose of this study was to determine the hydrocarbon formation zone. The research method to achieve the research objectives, among others, the first filtering performed on the data with a robust process. This process consists of Robust No Weight, Robust Rho Variance and Ordinary Cohenerency. The second step is done to change the format Selection XPR And Edi. A third inversion resistivity model for the review get a 2D cross section. Based on the findings of the eight data processing methods of measurement points obtained information Magnetotelluric rock formations. Formation hidrokrabon What are the areas is research a reservoir and caprock. The layer in 1600 m – 2700 m depth from the surface which resisvity 12 -33 m assumpted as clay cap. While the layer in 2700 m – 5000 m depth from the surface with high resistivity 41- 250 m is assumpted as oil sands (reservoir). The trap zone of this hidrocarbon formation categorized into structural trap which is the trap of anticline.

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.

Eight time-domain electromagnetic profiles were carried out in Harrat Ithnayn, northwestern Saudi Arabia, to detect potential groundwater-bearing aquifers in the area. The collected data were processed and analyzed, with the results inferred or extrapolated between one-dimensional vertical soundings to obtain two-dimensional resistivity sections of the subsurface geological setting. We found that the resistivity values change laterally and vertically throughout the area. High resistivity values (greater than 100 Ohm-m) occupy most of the sections down to depths of approximately 100–150 m, whereas the low-resistivity regions of the section appear to be shallower than 100 m toward the west in the northern part of Harrat Ithnayn. The high-resistivity regions correspond to the Harrat basalts and are underlain by low resistivity (down to a few Ohm-m) in the saturated zones. There are also localized regions of low resistivity at depths of approximately 20–30 m, indicating shallow local groundwater aquifers. Aquifer thickness varies from approximately 50 to more than 100 m. In the southern part, the resistivity sections indicate that the main aquifer is at a depth of 150–200 m (possibly near 170 m) below the basalt. A saturated zone or shallow aquifer approximately 20–30 m thick also exists at a depth of approximately 15 m. In both the shallow and deep aquifers, the resistivity values indicate that there is good quality fresh water.

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.

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.

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.

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.

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.

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.

${\mathrm{Sb}}_{2}{\mathrm{S}}_{3}$ 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.

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.

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.

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.

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.

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.

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.