Resistance Water Research Articles

Identification of Pulse Discharge Parameters in Water for Reservoir Resonance Transform Device

The reservoir resonance transform device is applied to unconventional shale gas stimulation. To achieve the purpose of resonance stimulation, the discharge frequency is dynamically corresponding to the natural frequency of the reservoir. However, the discharge parameters under the same conditions differ in the resonance process. It is hard to analyze the real-time change of reservoir frequency precisely. Therefore, the identification of pulse discharge parameters in water is extremely important. In this paper, an equivalent circuit model of pulse discharge in water is established to analyze the time-varying resistance. The Kalman filter makes the discrete resistance data continuous and reduces the interference caused by the random discharge. Meanwhile, the data error analysis is carried out. The results show that the variance of pulse discharge resistance in water based on the Kalman filter is less than 0.528 compared with the experiment value, so the identified resistance obtained by this method can be used in the study of resonant discharge in the same frequency.

Translocation and Utilization Mechanisms of Leaf Intracellular Water in Karst Plants Orychophragmus violaceus (L.) O. E. Schulz and Brassica napus L.

Orychophragmus violaceus (L.) O. E. Schulz adapts to karst environments through a variety of adaptability mechanisms. However, the leaf intracellular water translocation and utilization mechanism is still unknown. This study hypothesizes that plants adapt to dehydration by synergistically adjusting the leaf anatomy, cell elasticity and intracellular water translocation. Leaf structure, elastic modulus (Em), physiological capacitance (CP), impedance (Z), water potential (ΨL), leaf tensity (LT) and chlorophyll fluorescence parameters of the detached leaves in plants of O. violaceus and Brassica napus L. were measured at each water loss time (0, 1, 2, 3, 4 and 5 h). The uniform leaves were randomly selected from five different plants for each species. The cell vacuole volume and translocation resistance of intracellular water could be represented by the electrophysiological parameters, such as CP and Z. The results indicated that timely shrinkage of O. violaceus leaves and mesophyll cells together with the increased water translocation resistance retained the intracellular water and maintained the turgor pressure. Water within sponge parenchyma could also be translocated into palisade parenchyma. The PSII reaction center was kept stable, and the photosynthetic activity of O. violaceus was clearly inhibited at 3 h. Palisade parenchyma of B. napus leaves increased quickly to improve the intercellular water translocation due to the strong cell stiffness. Gradually increasing intracellular water translocation resistance and recovery of the cell elasticity slowed down the leaf water loss, which, however, could not timely stop the damage on the PSII reaction center and the photochemical efficiency. The photochemical efficiency was seriously inhibited at 4 h and 5 h. The response mechanism of intracellular water to dehydration can be investigated with the help of leaf electrophysiological traits. However, the direct determination of plant drought resistance using electrophysiological information can still not be realized at present and needs further research.

The study of physical-chemical characteristics of produced water and water of other origins

The physical-chemical characteristics of water from various fields and those of different origins, the water samples prepared from the mixture of solvents with produced water, as well as the salts formed on the ionic composition of these samples and their amount are studied, the comparison of electric conductivity with the mineralization carried out as well. The studies justify that the data on the electric conductivity and specific electric resistance of water from various fields may be used in the interpretation of produced water. The specification of the probability of entering extraneous water into the well is possible via the regular control of the study results on electric conductivity and specific electrical resistance of produced water. These studies enable us to previously estimate the mineralization in short term as well.

Reanalysis of the revised EEDI parameters for inland ships of Bangladesh

A revision of the Energy Efficiency Design Index (EEDI) formulation was previously proposed to be useful for inland ships of Bangladesh. The study incorporated the shallow water effect using Schlichting’s method which has been developed in 1934 based on a large number of ship model tests to show how a ship’s resistance in shallow water deviates from that in deep water. However, the evaluation and presentation of Schlichting’s results did not cover all range of ship parameters. This reanalysis has considered the shallow water effect by actual measurement of 15 inland ships of Bangladesh. Later, the results of Schlichting’s method were compared with (a) actual investigation, (b) an improved version of Schlichting’s method proposed by Lackenby in 1963, and (c) a new method proposed by C B Barrass in 2004. It was found that the deviations of Schlichting’s results are much higher than Lackenby and Barrass’s methods in comparison to the investigated results. In a previous analysis of the inland ships of Bangladesh, the Maximum Continuous Rating (MCR) of the main engine was considered by using the Holtrop-Mennen method. As this method requires too much ship data, that analysis had assumed some unknown required ship data. This reanalysis has overcome that problem by the physical investigations of the same 15 inland ships of Bangladesh. The average MCR for inland cargo ships and oil tankers of Bangladesh are measured as 70% by the investigations, whereas it is 80% for passenger ships.

Water Degradation in ITER Neutral Beam Test Facility Cooling Circuits

Source for production of ion of deuterium extracted from rf plasma (SPIDER) is the 100 keV negative ion source prototype of the ITER neutral beam injector. The cooling plant is one of the SPIDER auxiliary systems where ultrapure water (UPW) is used as the cooling media, thanks to its advantageous properties such as good cooling performance and high resistivity. Water resistivity needs to be maintained above certain values during SPIDER operation to enable the electrical insulation of in-vessel components that operate at different voltages. Nonetheless, degradation of water resistivity was observed in some circuits during operation. Water resistivity degradation had a negative impact on the SPIDER experimental campaign since it limits cooling plant availability. To understand the cause for the observed water degradation, sampling points were installed to sample water during operation. Ad hoc experiments have been performed on the worst affected circuit, and water samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Circulation experiments were conducted at constant temperature, pressure, and flow rate to assess water degradation by monitoring water conductivity increase. ICP-MS analyses on water from the worst affected circuit revealed the presence of Cu in relevant quantities and Zn. Corrosion induced by the presence of a non-compatible component with SPIDER requirements was found. The identified component was made of a galvanized steel plate, carbon steel, and brass. This was found responsible for the contamination of the cooling loop and its water properties’ degradation.

Corrosion and Metal Release of Copper and Stainless Steel Exposed to Ultrapure Water

Source for Production of Ion of Deuterium Extracted from Rf plasma (SPIDER) and Megavolt ITer Injector and Concept Advance (MITICA) experiments are actively cooled by ultrapure water (UPW) to electrically insulate in-vessel components that are polarized to high voltage levels. Water circulating in cooling pipes reacts with wetted surfaces made of copper and stainless steel, causing water resistivity degradation. First investigations on the causes that might determine water degradation highlighted the necessity to measure release rates of the main materials (copper and stainless steel) exposed to UPW as a baseline study to better understand the release rates measured during experimental campaign in the real cooling circuits in SPIDER and MITICA. This article presents first the experimental results of stainless steel and copper samples exposed to stagnant UPW at ambient temperature and high oxygen environment to measure the ion release behavior. Trace metal analysis using inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify metals released in solution, and scanning electron microscope (SEM) was used to characterize the oxide formed on the sample surface after the exposure.

Fabrication and Supercritical Water Corrosion Resistance of TiN/TiNC/Al2O3 Multilayer Coating on Inconel 625 Alloy by CVD Method.

A TiN/TiNC/Al2O3 multilayer coating was deposited on an Inconel 625 alloy by the chemical vapor deposition method as a protective barrier to improve the corrosion resistance in supercritical water. The corrosion characteristics were evaluated in a reactor at 500 °C and 25 MPa for 72 h. The surface morphology of the coated samples was relatively dense with no obvious cracks or pores observed. The XRD analysis revealed that the coatings were composed of TiN, TiNC and α-Al2O3 phases. After exposure to supercritical water, the surface morphology of the coatings was still dense and kept integrity. The phase composition of the coatings was also not changed, with no obvious corrosion scales detected. This result demonstrates the effectiveness of TiN/TiNC/Al2O3 coatings as a protective coating under harsh supercritical water environments.

Trans-media resistance investigation of hybrid aerial underwater vehicle base on hydrodynamic experiments and machine learning

In this paper, the trans-media hydrodynamics of a multi-rotor hybrid aerial underwater vehicle (HAUV) is studied base on experiments and machine learning. First, experiments are conducted to obtain the hydrodynamic forces during water exit/entry. Then, based on the experimental data and phenomena, it is evident that the multi-rotor HAUV's total resistance, particularly the impact of the arms, should not be ignored. The overall resistance is primarily affected by the depth and velocity at constant velocity. The total resistance increases as the velocity increases. The maximum total resistance in water exit/entry can be 46%/64% of gravity. Finally, a two-layer feed-forward network with six sigmoid hidden neurons and linear output neurons is used for machine learning training. The training results show that using experimental data and a machine learning method, the trans-media resistance of HAUV can be accurately predicted within a certain range.

Numerical Simulation on Dynamic Characteristics of Longitudinal Launching of Large Container Ships

The upsizing and rapid development of container ships has resulted in many large ships launching in small slipways due to the lagging of advanced equipment. In particular, the dynamic characteristics of these large ships in the longitudinal launching operation under restricted water are yet to be studied in detail. In this study, a ship model to simulate the longitudinal launching process of an 8500 TEU container ship was created based on the URANS method. The ship resistance in calm water was determined and validated against the experimental data. The influence of the stern appendage on the ship’s resistance and the flow field around the hull, with and without the aft poppet, under various water-depth-to-draught ratios was analyzed. A comparison of the ship’s resistance between the numerical and the experimental data shows that the difference is minimal, within 1.5%. The numerical results revealed that the aft poppets change the flow pattern and effectively reduce the pressure drag in the drifting stage. The shallow water causes a restraining effect on the ship. The proposed analytical approach in the numerical analysis, considering the aft poppet and the water depth, could provide a better simulation for a large ship’s longitudinal launching operation.

Genetic Mechanisms and Identification of Low-Resistivity Pay Zones: A Case Study of Pengyang Area, Ordos Basin, China

The Triassic Yanchang Formation in the Pengyang area of Ordos Tianhuan depression is an important oil and gas formation. However, most of the oil pays in the study formations are low-resistivity or low-contrast reservoirs with low permeability, bringing challenges to the reservoir identification and evaluation by well logs. In this paper, we first measured the nuclear magnetic resonance (NMR), phase permeability, cation exchange capacity (CEC), and X-ray diffraction for core samples. Then, the genetic types for the low-resistivity pays were analyzed based on the experiment results, water analysis, and well log data collected. It was found that large variations of formation water salinity, high irreducible water saturation, and clay conductivity are the primary genetic types. Further, the random forest (RF) algorithm with sensitive parameter inputs was used to identify the oil, oil and water, and water layers. The anomaly of spontaneous potential (∆SP) that characterizes water salinity, the relative value of gamma ray log (∆GR) that describes the bound water content, resistivity, density, and acoustic logs were taken as sensitive logs according to the genetic analysis. Finally, this identification method was verified by comparison with the traditional crossplot method and oil test results. The identification accuracy of the RF is 90%, far higher than that by the crossplot method.

Influence of Seawater Cation Contamination on the Performance and Lifetime of PEM Electrolysis Cells

Polymer electrolyte membrane water electrolysis (PEMWE) requires highly purified water (resistivity ≥ 1 MOhm·cm). If the electrolyzer is fed with water of poor quality, both the lifetime and the performance are reduced. [1] Mainly cationic species cause several degradation effects in the membrane and the catalyst layer of the cell. Within the membrane, protons are exchanged by the cations, leading to a reduced ionic conductivity. Further, according to Fenton's reaction, some transition metal cations catalyze the formation of radicals attacking the membrane structure. [2] Additionally, the catalyst layer is occupied with cations, which causes a reduced electrochemical surface area. [3] For offshore applications of PEMWE, the feed water is generated by the purification of seawater, which contains a high amount of impurities such as calcium and magnesium. [4, 5] This purified seawater nevertheless contains some impurities [4] and as soon as the purification process is erroneous, the PEMWE is contaminated with the cations. For that reason, the scope of this contribution is to find a threshold value of a magnesium and calcium contamination in the water supply of a PEM water electrolysis cell, which affects the cell performance and lifetime to a tolerable extent.To do so, electrolysis cells equipped with commercially available catalyst coated membranes (CCM) are contaminated with magnesium and calcium solutions of different concentrations and operated for up to 100 h. The actual performance of a cell is measured by polarization curve and electrochemical impedance spectroscopy every 25 h. In order to get deeper insights into the degradation phenomena, several in- and ex-situ characterization techniques are used. The investigation contains ion chromatography (IC), inductive coupled plasma mass spectroscopy (ICP-MS), mass spectrometry (MS) and thermo-gravimetric analysis (TGA).The polarization curves show the cell's overall performance over time but give only a little information about the occurring phenomena. The high frequency resistance of the measured impedance spectra can determine the change in the ionic resistance of the membrane. This ionic resistance increases when the cations occupy the active sides of the membrane. Otherwise, a possible membrane thinning caused by the radical attack decreases the ionic resistance. To distinguish between these antithetical effects, the fluoride concentration in the water supply is measured with an anion IC. The resulting fluoride emission rate correlates with membrane thinning and quantifies this effect. Another method to detect membrane thinning is investigating the process gases with MS. The occurring gas crossover, especially at the anode with its H2 in O2 content, indicates a membrane thickness change. The occupation of the catalyst particles by cations is measurable in-situ by tracking the polarization current at a set potential over time and the impedance spectra reveal changes in the charge-transfer and resistance characteristics as well. Other degradation effects like losing catalyst particles because of weak ionomer structure or catalyst dissolution are investigated with the ICP-MS, which measures the metal concentration in the process water. At the end of the test procedure, the CCMs are analyzed in the TGA to investigate the thermal stability after the operation and the residual weight fraction of the catalyst particles, which is also an indicator for catalyst loss. With these in- and ex-situ characterization techniques, the degradation effects in a PEM electrolysis cell caused by different cation contaminations are investigated separately and their specific contribution is revealed. With this knowledge of different cation concentrations, a relation is derived to find a tolerable concentration of cations in PEM electrolysis operation.

Natural-product-derived membranes for high-efficiency anionic dye removal

Nature possesses inexhaustible resources that inspire researchers to convert natural products into functional materials. Membranes with excellent permeability to balance the trade-off relationship between permeance and retention are highly desirable in the water-purification field. Herein, β-cyclodextrin (β-CD) and sodium ligninsulfonate (SLS) as derivatives of natural products were utilized to construct membranes with enhanced permeability via a facile molecularly engineered interfacial polymerization with 1,3,5-trimesoyl chloride. β-CD with an inner cavity of intrinsic 3D hollow bowls of several angstroms in diameter and hydrophilicity, it was utilized to reduce the permeation resistance of water. SLS endowed the newly designed SLS-CD-2 membrane with a highly negatively charged surface. Thus, the fabricated SLS-CD-2 membrane demonstrated a high permeance of 33.7 L m−2 h−1 bar−1 and a rejection rate of 99.8% for the filtration of Congo red solution. A 91.5% increase in permeance and a negligible change in retention were observed for the SLS-CD-2 membrane compared with those of the membrane without β-CD. The SLS-CD-2 membrane also exhibited excellent separation performance for the filtration of mixed-dye solution, high separation stability, and outstanding anti-pollution capacity. The results indicated the importance of the newly designed membrane in separation processes.

A numerical approach to accurately estimate water resistivity (Rw) and saturation (Sw) in shaly sand formations

In hydrocarbon reservoirs, the accuracy of hydrocarbon saturation depends on the precision of the water saturation and resistivity (Sw and Rw). A significant interpretation parameter is the resistivity of formation water (interstitial water or connate water which is, uncontaminated by the drilling mud that saturates the porous formation rock) because it is appropriate for the calculations of saturation (water and/or hydrocarbon) from basic resistivity logs. The most reliable way to determine this value is through the determination of the chemical composition or resistivity of uncontaminated connate water inside the formation. The saturation of water is the ratio between water volume to total pores volume and its determination accuracy has a great role in estimating hydrocarbon volume. However, the aims of this paper have two main folds, firstly, to introduce a complete review on water resistivity, saturation, and shale volume. Secondly, it presents a numerical method for the determination of resistivity of connate water and water saturation from the true resistivity of the formation using Schlumberger (1975) in shaly sand formations which require critical treatment compared to the clean sand reservoirs. To ensure its ability to determine both the resistivity and saturation of formation water, the technique was tested using synthetic and real field data.

Theoretical Study on the Dynamic Characteristics of Marine Stern Bearing Considering Cavitation and Bending Deformation Effects of the Shaft

When the ship runs, owing to the superposition of the gravity of the shaft and resistance of water, with the increment in rotational speeds, the shaft will produce different degrees of bending deformation, which immensely reduces the power transmission efficiency. Based on the aforementioned problem, the present study focuses on the influences of bending deformation of the shaft with a cavitation effect on the dynamic characteristics of the stern bearing. The mixed lubrication model with bending deformation and cavitation effect is established. At present, the deflection curve equation is employed, the finite perturbation method is applied to calculate the dynamic coefficient, and the cavitation pressure is determined by the numerical method. According to the analysis, the variation laws of equivalent stiffness and natural frequency are exhibited. It is shown that the equivalent stiffness is more affected by the speeds, especially at low speeds; There is a critical speed between 130 rpm and 150 rpm, which makes the natural frequency strike the maximum value. Finally, the research results provide a theoretical basis for the ships to avoid large vibration during navigation.

Dissemination of Carbapenemases and MCR-1 Producing Gram-Negative Bacteria in Aquatic Environments in Batna, Algeria.

Antibiotic-resistant-bacteria are being considered as emerging environmental contaminants where the importance of the surrounding environment in their emergence and dissemination has been emphasized. The aim of this study was to screen for the presence and diversity of carbapenem- and colistin-resistant Gram-negative bacteria (GNBs) in different aquatic environments. Water samples were collected in Batna, Algeria. Carbapenem- and colistin-resistant GNBs were selectively isolated and then identified using matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. After phenotypic antibiotic susceptibility testing, the molecular mechanisms of β-lactams and colistin-resistance were investigated by PCR and sequencing. The clonality of mcr-1 positive Escherichia coli was determined by multi-locus sequence typing. We noticed a high level of resistance in both tap water and wastewater. The most commonly found carbapenem-resistance mechanism was the OXA-48 enzyme, but other carbapenemases were also detected. In addition, the mcr-1 gene was detected in 18 E. coli of different sequence types. Our findings highlight the role of aquatic environments in the dissemination of resistant-bacteria, especially considering that water is a connecting medium between different ecological systems and can easily transmit resistant-bacteria and promote horizontal gene transfer. Thus, the development of effective treatment strategies for eliminating antibiotic-resistance is seriously needed.

Quantitative Evaluation of Water-Flooded Zone in a Sandstone Reservoir with Complex Porosity–Permeability Relationship Based on J-Function Classification: A Case Study of Kalamkas Oilfield

The water-flooded zone in a sandstone reservoir with a complex porosity–permeability relationship is difficult to interpret quantitatively. Taking the P Formation of Kalamkas Oilfield in Kazakhstan as an example, this paper proposed a reservoir classification method that introduces the J-function into the crossplot of resistivity and oil column height to realize the classification of sandstone reservoirs with a complex porosity–permeability relationship. Based on the classification results, the initial resistivity calculation models of classified reservoirs were established. The oil–water seepage experiment was performed for classified reservoirs to measure the lithoelectric parameters and establish the relationship between water production rate and resistivity for these reservoirs, and then water production was quantitatively calculated according to the difference between the inverted initial resistivity and the measured resistivity. The results show that the reservoirs with an unclear porosity–permeability relationship can be classified by applying the J-function corresponding to grouped capillary pressure curves to the crossplot of oil column height and resistivity, according to the group average principle of capillary pressure curves. This method can solve the problem that difficult reservoir classification caused by a weak porosity–permeability correlation. Moreover, based on the results of reservoir classification, the water production rate and resistivity model of classified reservoirs is established. In this way, the accuracy of quantitative interpretation of the water-flooded zone in the reservoir can be greatly improved.

High-temperature and abrasion resistance of self-compacting mortars incorporating binary and ternary blends of silica fume and slag

Researchers from all over the world have recently developed an interest in the utilization of waste materials in the concrete industry. Using silica fume (SF) and ground granulated blast furnace slag (S) to manufacture self-compacting mortars (SCMs) could be a step toward sustainable waste management and produce the unique fresh qualities needed for SCMs. This research evaluates the abrasion and high-temperature resistance of SF and S based SCMs. A total of 14 mixtures were designed by partially replacing SF and S with Portland cement (PC) including control, binary and ternary mixtures. Binary mixtures were obtained by replacing cement by SF and S at replacement rates of 5, 10, 15 and 20 % and 10, 20, 30 % by weight respectively. Ternary mixtures were determined at the rates of 5, 10, 15 and 20 % SF and 10 and 20 % S respectively. The flexural strength and compressive strength of SF and S based binary and ternary water curing SCMs samples were determined at the age of 7, 28 and 90 days at room conditions. SCMs specimens were exposed to high temperatures after 90-day water curing. Water absorption, apparent porosity, sorptivity and abrasion resistance of 28-day water cured SCMs samples was also determined. The fresh and rheological properties of SCMs was evaluated by conducting mini-slump flow and viscosity tests. Cost analysis of the SCMs were also performed. The experimental results exhibited that the flowability of SCMs mixes containing SF was reduced with the increasing rate of SF compared to control while the workability of S incorporated SCMs mixes increased with the increase of S in comparison to control mixtures. Late- age of compressive strength above 70 MPa was achieved for 20 % SF incorporated binary mixture and 15 %SF and 10 % S incorporated ternary mixture. The ternary mixture with 15 % SF and 10 % S also exhibited the best abrasion resistance and the lowest sorptivity. Overall, it can be concluded from the mechanical characteristics and abrasion resistance that ternary combination of S with SF content of especially above 10 % and can be used to manufacture self-compacting mortar with a smaller carbon footprint.

Assessment of Carbon Dioxide Storage Capacity of Selected Aquifers in ‘J’ Field, West Africa

combination of seismic data and petrophysical logs from five wells acquired in ‘J’ Field, Niger Delta, Nigeria, have been analyzed to assess the carbon dioxide (CO2) storage potential of some saline aquifers in ‘J’ field. The study aims to evaluate the volume of CO2 that can be potentially stored in the aquifers and the risk of CO2 leakages in the storage. The sand aquifers were correlated across the five wells to evaluate their thicknesses and lateral extent. Porosity, permeability, formation water resistivity, and net sand thickness were estimated in the different wells. The Horizons corresponding to the top of the aquifers was mapped, and time and depth structured maps were generated for structural analysis and volumetric estimations. The risk of CO2 leakages through sealing layers (cap rocks) was evaluated in terms of caprock integrity and pore pressure sealing mechanism. Results of the study showed that four aquifers, namely, L20, N30, M40, and P50, are laterally extensive across the five wells and have thicknesses that range from 14 to 352 m. The individual CO2 storage capacity of L20, M30, N40, and P50 was estimated to be 6.97×1010, 1.48×1010, 7.78×109 and 1.49×1010 tons, respectively. The combined aquifer storage capacity was estimated to be 1.07×1011 tons. The sealing layers have low risk of CO2 leakages. The study concluded that the aquifers have good potential for CO2 storage and low risk of leakages. The study ranked L20 as the best among the four aquifers.

GEORADAR AND RADIOIMPEDANCE DIAGNOSTICS OF THE SELENGA RIVER WATER AREA

The relevance of the work is determined by the fact that no radiowave methods have ever been used to study the water areas of rivers and lakes and their geoelectric sections within the Baikal natural territory (BNT) in winter time. The purpose of the research is to determine the electrical and geometric characteristics of the layered medium "ice – water – bottom soil" and the ice cover of the Selenga River on the BNT in the VLF-LF and VHF radio wave bands according to the data of instrumental radiophysical measurements by GPR and radio impedance methods, including the determination of the structure of the ice crossings over the Selenga River. Using the Selenga River as an example, consideration has been given to the results of combining VLF-LF and VHF methods of electromagnetic diagnostics of a layered medium in a wide range of radio waves (from tens of kilohertz to units of gigahertz). Radio impedance profiling and sounding in the VLF-LF bands with the IPI-300 equipment made it possible to determine the sub-bottom structure of the soil from the change in impedance and geoelectric section. GPR in the VHF band made it possible to differentiate the fine structure of the Selenga River in winter by thickness of snow, ice and water. The sounding involved the use of georadar "Oko-2" with antenna units "Triton" (central frequency 50 MHz), AB-400 (central frequency 400 MHz), AB-700 (central frequency 700 MHz), and AB-1700 (central frequency 1700 MHz). The thickness of ice of the road crossing in the Mostovoy microdistrict of Ulan-Ude city was 0.5–1.2 m – 0.1–0.2 m thicker than that beyond the road crossing. It was found that the presence of snow cover beyond the road crossing prevents the ice mass from freezing. Calibration sounding of ice with borehole drilling yielded ice dielectric constant ε=3.17. The specific electrical resistance (SER) of water from boreholes is 71–74 Ohm·m at a temperature of 1 °C. The methods used complement each other and provide a quantitative description of the object of research. The integration of various methods of radio wave diagnostics provides more detailed information on the structure of the layered medium "ice – water – bottom soil". The obtained results and the developed methods of radio impedance and GPR sounding and profiling of an inhomogeneously layered underlying environment in winter time can be used in engineering and geological surveys in the eastern and northern regions of Russia.

Experimental study of water migration characteristics in compacted loess subjected to rainfall infiltration.

In order to study the effect of the rainfall infiltration on water migration in compacted loess, a model device was developed for testing water migration in the soil under rainfall conditions. In this study, the volumetric water content and resistivity of soil were introduced into the model test device. This model test device was applied to the study of water migration characteristics in compacted loess under different rainfall conditions. The results show that the resistivity decreases with the increase of the volumetric water content at the same depth of the loess column. In this way, the characteristics of the water migration can also be reflected from the change of the resistivity. There is an intimate relationship between the resistivity and volumetric water content, dry density. The volumetric water content and dry density are normalized by saturation of loess, arriving the equation of saturation against the resistivity. The characteristics of rainfall infiltration in compacted loess show a particular pattern, which demonstrates that, with the increase of dry density of the loess column, the rainfall infiltration line present "Y", "D" and "Λ" shape distribution respectively, under light rain, heavy rain and rainstorm.