Linear Zone Research Articles

Using a novel MR imaging sign to differentiate retinal pigment epithelium from uveal melanoma.

Retinal pigment epithelium (RPE) adenoma is a rare intraocular benign tumor. It is almost always misdiagnosed as uveal melanoma (UM) resulting in inappropriate management. The purpose of this study was to investigate MRI features of the RPE adenoma that may help differentiate this entity from UM. MRI was performed in eight patients with pathology-proven RPE adenoma, five of whom had dynamic contrast-enhanced (DCE) MRI. The time-intensity curves (TIC) of all DCE-MRI were evaluated, and the maximum contrast index (CImax) were calculated. All eight tumors showed well-defined margins. They were homogeneously hyperintense on T1WI and hypointense on T2WI compared to vitreous body. An oval mass was seen in five tumors, lentiform in two tumors, and placoid-shaped in one tumor. After contrast administration, mild enhancement was identified in five tumors and moderate enhancement in three tumors. In all five tumors, DCE-MRI exhibited a plateau-shaped TIC with a median CImax of 0.37. A "dark-linear sign" (defined as low signal intensity linear zone located between tumor and enhanced choroid on post contrast T1WI with fat-suppression) was noted in all eight patients with RPE adenoma. RPE adenoma and UM often have similar MR imaging findings. This study reports for the first time a "dark-linear sign" on post contrast T1WI with fat-suppression seen in RPE adenoma. This observation may be characteristic of RPE adenoma and may help separate this entity from UM.

Data Retrieval Method based on Physical Meaning and its Application for Prediction of Linear Precipitation Zone with Remote Sensing Satellite Data and Open Data

Data retrieval method based on physical meaning is proposed together with its application for prediction of linear precipitation zone with remote sensing satellite data and open data. The linear precipitation zone causes extremely severe storm and flood damage, landslide, and so on. Linear precipitation zone is formed in the case that the warm, moist air must continuously flow in, the force to lift this air up and it is often in collisions with mountain slopes or cold fronts, the atmospheric conditions are unstable, and there is a certain direction of wind above the sky. These conditions can be monitored by remote sensing satellite data. The proposed method is intended to attempt for prediction of the linear precipitation zone for disaster mitigation. There are water vapor data, cloud liquid data, cloud fraction data, and upper atmospheric wind data derived from the remote sensing satellite-based mission instruments. Through experiment in the case of the linear precipitation zone which was occurred in northern Kyushu, Japan in the begging of July 2020, a possibility to detect the linear precipitation zone was confirmed. Also, flooding damages and other disasters occurred in the northern Kyushu, in same time period caused by the detected linear precipitation zone is detected with Sentinel-1 of SAR data.

Approximate Time-Optimal Control Considering System Bandwidth and Saturation

Time-optimal (TO) control is promising in many fields since it ensures to accomplish a task in minimum time. However, its direct application may cause oscillations or even limit cycles due to the restriction of the sampling period, state measurement accuracy and so on. To solve these problems, a compound proximate time-optimal (PTO) control law is proposed by considering system bandwidth and saturation in this paper. With the help of the phase plane, the switching zone and linear zone of the PTO control law are constructed. When the system state lies outside of both switching and linear zones, the bang-bang optimal scheme is adopted to achieve rapidity. And when the system state enters the switching zone, the bang-bang suboptimal scheme is developed to avoid oscillations or even limit cycles. Proportional-derivative (PD) scheme is applied in the linear zone to obtain local asymptotic stability around the origin. Numerical simulations are carried out to corroborate the advantages of the PTO control law.

Effective Lifetime Experimental Measurement under External Magnetic Field in Transient Dynamic State Obtained from a Square Electrical Excitation by Open Circuit Voltage Decay Method

In this work, we present an experimental transient 3-Dimensionnal study for the minority charge carriers’ effective lifetime measurement under magnetic field in transient dynamic state. The magnitude of the magnetic field B is varied from 0 mT to 0.03 mT. The method used is mainly based on the open circuit voltage decay method. The solar cell is injected by a low electrical excitation which protects against capacitance effects. Our approach is based on the open circuit voltage decay response analysis. From an experimental set-up, we get the transient voltage data on a digital scope. The data are used for plotting transient voltage decay curves. The curves obtained and analyzed are fitted in their linear zone. This zone presents an ideal decay which permits to get good values of lifetime. The slope of the linear decay is inversely proportional to effective lifetime. The results of fitting permit determinate the effective charge carriers’ lifetime directly. The results obtained are then presented and analyzed. The observations indicate that the charge carriers effective lifetime decrease when the magnetic field increases.

The T-stress influence on the plastic zone size around the crack tip under the thermal load

A review of the fracture mechanics problems for estimating the safety of constructions with the crack-like defects is carried out. The need to develop a new methodology that combines the advantages of calculation and instrumental methods was revealed. The correlations between the most important fracture mechanics parameters and the characteristics of acoustic-emission signals proposed to use for estimating the parameters of stress-strain state. It is noted that considerable attention should be paid to the size and shape of the plastic zone in order to establish a theoretical relationship between the characteristics of acoustic signals and the fracture mechanics parameters. It is assumed that T-stresses are the cause of differences in the coefficients of the power dependence of the parameters of acoustic signals for the same values of the stress intensity factor. The task of finding the influence of T-stresses on the size of the plastic zone at the crack tip is set. A numerical modeling of thermal loading of a steel sheet with a central crack by the finite element method is carried out in order to determine the dependence of the crack tip plastic zone size on the stress intensity factor for several values of T-stress. Multiple calculations of the stress intensity factor and the T-stresses were performed for the several values of the cooling zone, using the parametric design language ANSYS APDL. By substituting the yield point of the material into the equations of linear elastic fracture mechanics, the specific volume and linear plastic zone size along the crack line were determined for the previously found values of the stress intensity factor and T-stress. A relationship between the fracture mechanics parameters and the plastic zone size at the crack tip was established using numerical methods. The assumptions that the T-stress influence to the plastic zone size are qualitatively confirmed. It is shown, that the negative values of T-stresses decrease the plastic zone size for a same value of the stress intensity factor.

Numerical Test Research on Loading Rate Effect of Rock Mass with Transfixion Sawtooth Structural Plane

In this paper, numerical test research is carried out on the loading rate effect of a numerical specimen (sample C) with a transfixion sawtooth structural plane by using the rock failure process analysis (RFPA) 2D software. In order to study the mechanical characteristics difference between the rock mass with this kind of structural plane and other rock masses, the intact numerical specimen (sample A) of no structural plane and the numerical specimen (sample B) with smooth structural plane are also simulated. The uniaxial compression tests were carried out for each specimen under five loading rates of 0.002, 0.005, 0.008, 0.02, and 0.05 mm/s. The following several conclusions are obtained by the numerical test. When the loading rate is 0.002 or 0.005 mm/s, the failure mode of the numerical specimen C is an inclined linear fracture zone located in the middle and lower part of the rock mass; however, when the loading rate rises to 0.008, 0.02, and 0.05 mm/s, the fracture zone of the numerical specimen C is located in the middle and upper part of the rock mass, and its inclination angle is about 60 degrees. The peak strength, residual strength, and stress drop of the specimens A, B, and C increase with the addition of loading rate; the peak strength and stress drop of the sample C are higher than those of the other two samples. When the loading rate is 0.002 mm/s, the residual strength of sample C is lower than that of samples A and B, and the other four kinds of loading conditions are higher than those of specimens A and B. Based on the acoustic emission (AE) information, it can be seen that the failure modes of the numerical specimen C under five loading conditions are tensile failure. The AE accumulated energy decreases with the increase of loading rate, but the change law of AE accumulated number is opposite.

Tectonic inversion of the Dnieper-Donets basin. Part 1. Collizion tectonics of the Western-Donets graben

Formulation of the problem. New results of tectonophysical studies of the structural-kinematic evolution of the Earth's crust of Dnieper-Donets paleorift at the collision stage are presented in the paper. The subject of research is a complex of deformation structures that complicate the sedimentary cover in the transitional zone with Donets folded structure. Review of previous publications and studies. According to new mapping data, tectonic deformations of the sedimentary cover were controlled by systems of faults of the north, northwest, and southeast vergence. The lattices of the Hercynian, Lamaric, and Attic tectonites determine the specific “cross-thrust” structure of pushing. Due to the heterogeneous distribution of deformations of different ages, the stratigraphic volume of the sedimentary sequence varies in area from the Pliocene-Anthropogenic to the Mesozoic-Cenozoic. Overthrusts and linear folding of three generations permeate the sedimentary sequence of the transition zone from east to west for hundreds of kilometers within the eastern part of Izyumsky paleorift segment. Methods. Using the original method of tectonic deformation fields’ reconstruction and tectonophysics analysis of structures, collision deformations of the platform sedimentary cover of the southeastern part of Dnieper-Donets depression are studied. The materials of geological mapping of the transition zone and instrumental definitions of the vergence of the Hercynian, Laramian, and Attic faults constituted the analytical base of tectonophysical studies. Results. In the transition zone, West-Donets segment of the tectonic wedging, which completely destroys the riftogenic structure in the southeast of the basin was identified. It was formed as a result of a thrust on the syneclise autochthon repeatedly deformed, crumpled into the folds of geomass from the western slopes of Donets folded structure. It consists of structural ensembles of linear thrust folds, tectonic covers of transverse, pushing of sedimentary geomas from axial to onboard zones, and folded covers of longitudinal thrust. The thrust covers and folds of allochthon end in the depression with scaly compression fans formed at the ends of the main thrusts. In the thrust front of West Donets segment, a geodynamic discharge strip was diagnosed, where structural zones of displacement of geomass were formed. On the north-eastern flank of the thrust front they are represented by large linear anticlinal zones of the so-called “open Paleozoic structures”, such as Torsko-Drobishevsk, North-Donets, Matrossko-Toshkovsk zones, and on the southwestern - Petrovsky-Novotroitsk zone of reverse-folds. The structural peak of the West-Donets segment is the tectonic node of thrusts and strike-slips of three generations, localized in the joint area of the central and southern structural branches of the axial salt-dome folding. Scientific novelty and practical significance. The current regional tectonic scheme has been revised on the conceptual foundations of dynamic geotectonics. It is shown that the riftogenic structure of the transition zone at the collision stage of evolution was completely destroyed by deformations of three generations. Lattice of tectonites, thrust cover and uplift folding zones of the Hercynian, Laramian, and Attic generations together form West-Donets cover-fold region within it. The main tectonic element of the region is the segment of the tectonic wedging of the same name. By the nature of the structure in its northern part, Lugansk-Kamyshevakhsky district is distinguished by a link echelon of linear folding, and in the south by Kalmius-Toretsky region of tectonic thrust cover. West Donets segment is an important component of the structural-tectonic frame of the sedimentary cover, which determines the modern transverse tectonic segmentation of the paleorift.

Predictive Mapping of the Mineral Potential Using Geophysical and Remote Sensing Datasets in Parts of Federal Capital Territory, Abuja, North-Central Nigeria

Mineral Prospectivity Mapping (MPM) is a multi-step process that ranks a promising target area for more exploration. This is achieved by integrating multiple geoscience datasets using mathematical tools to determine spatial relationships with known mineral occurrences in a GIS environment to produce mineral prospectivity map. The study area lies within Latitudes 9° 00ʹ N to 9° 15ʹ N and 6° 45ʹ to 7° 00ʹ E and is underlain by rocks belonging to the Basement Complex of Nigeria which include migmatitc gneiss, schist, granite and alluvium. The datasets used in this study consist of aeromagnetic, aeroradiometric, structural, satellite remote sensing and geological datasets. Published geologic map of the Sheet 185 Paiko SE was used to extract lithologic and structural information. Landsat images were used to delineate hydroxyl and iron-oxide alterations to identify linear structures and prospective zones at regional scales. ASTER images were used to extract mineral indices of the OH-bearing minerals including alunite, kaolinite, muscovite and montmorillonite to separate mineralized parts of the alteration zones. Aeromagnetic data were interpreted and derivative maps of First Vertical Derivative, Tilt derivative and Analytic signal were used to map magnetic lineaments and other structural attributes while the aeroradiometric dataset was used to map hydrothermally altered zones. These processed datasets were then integrated using Fuzzy Logic modelling to produce a final mineral prospectivity map of the area. The result of the model accurately predicted known deposits and highlighted areas where further detailed exploration may be conducted.

Modelling the Force Action of a Liquid on the Shutter of a Measuring Transducer

The article describes the original design of the measuring transducer of angular velocity of the type “flapper-nozzle “. The aim of the study is mathematical modeling in the MathCAD program of the force action of liquid jets exiting nozzles, since this significantly affects the characteristics of the converter. The calculated values of the acting forces are compared by several known methods and their results are compared with experimental data. For the proposed design of the measuring transducer, greater convergence of the theoretical and experimental values of the power characteristic in the linear section is provided by the expressions for determining the force effect of two jets on the damper, defined as the hydrodynamic effect of the liquid jet on the obstacle. Given the real differences in the design of the converter from theoretical models, it is required to apply correction factors. As pressure increases, the coefficient increases from 1 to 1.24-1.30 depending on the pressure supplied to the measuring transducer and the version of expression used to calculate it. When using the expression for the approximate calculation of the acting forces in the converter, the correction factor is much higher and varies from 1.9 at a supply pressure of 0.5 MPa to 1.74 at a supply pressure of 1.5-2.0 MPa. The practical use of this calculation option is limited to the linear zone of pressure dependence in the working chambers of the converter on the gap between the nozzles and the shutter.

Characterization of nutritional and functional properties of "Blanco Sinaloa" chickpea (Cicer arietinum L.) variety, and study of the rheological behavior of hummus pastes.

In this work the preparation of a hummus pastes from a Mexican variety of chickpea (Blanco Sinaloa, BS) was investigated. With this purpose, the nutritional and functional properties of the raw chickpea were evaluated, which revealed a content of protein, fiber and lipids of 19, 1.6 and 10.3%, respectively. Meanwhile the values of hydration capacity, water absorption index, water solubility index, emulsifying activity and foam capability were 0.65g/seed, 2.26g/g, 22.3%, 40.7% and 29.2%, respectively. Based on these results this variety of chickpea was considered suitable for the target application. The preparation of the paste was done by further sterilization of the paste promoted a decreased on the activity of lipoxygenase (68%) and starch content (40%). The rheological characterization of the hummus paste showed that the sterilization induced the formation of a tridimensional structure, due to the gelatinization of the starch and protein denaturation. Moreover, the linear viscoelastic zone shifted to higher values of strain (%γ), whereas the storage modulus (G') increased in about two orders of magnitude. The results of frequency sweeps showed that the paste exhibits a solid-like behavior (weak gel). Measurements of shear rate of the paste (unsterilized and sterilized) revealed that the shear viscosity exhibited a shear thickening behavior and a thixotropic behavior.

Structural evolution of hard-elastic polyethylene cast film in temperature-strain space: An in-situ SAXS and WAXS study

Hard-elastic polyethylene (HEPE) cast films are the key intermediate product for producing PE microporous membranes (dry process) used as separators in Lithium battery. The effects of temperature on the deformation mechanisms of HEPE cast films are systematically studied with in-situ synchrotron radiation small- and wide-angle X-ray scattering (SAXS/WAXS) techniques during stretching in a wide temperature range from 25 to 135 °C. The structural evolutions and mechanical behaviors show three distinct features, which contribute to the rough divisions of the temperature space into three regions (I/II/III) with α-I relaxation temperature (TαI) and the onset melting temperature (Tonset) as the boundaries. On the basis of the evolutions of the structural parameters like long period (Lm), micro-strain (εm), orientation parameter (f200), crystallinity (Xc), and etc., lamellar separation is the main deformation mode in the linear elastic strain zone. And microphase separation of interlamellar amorphous, lamellar crystal slipping and melt-recrystallization are proposed to determinate the later non-linear mechanical behaviors in the three temperature regions, respectively. The full view of deformation mechanisms in the 2D temperature-strain space aids to deepen the understanding of the nonequilibrium structural evolutions in hard-elastic polyethylene films and guide the manufacture of high-performance microporous membranes with dry process.

Probabilistic Evaluation of Off-Fault Displacements of the 2016 Kumamoto Earthquake

The 2016 Kumamoto earthquake occurred on April 16, 2016, and induced the complex distribution of surface ruptures and fault displacements, which revealed the difficulty of evaluating off-fault displacement hazards. The evaluation of off-fault displacements is necessary for the site investigation of an important facility, such as nuclear installations, but is difficult because off-fault displacements are thought to occur on unmapped or small-scale structures. A probabilistic fault displacement hazard analysis (PFDHA) assesses an off-fault displacement hazard as well as an on-fault one. Several PFDHA models have been developed from fault displacement datasets parsed by global-specific and Japanese-various faulting types. We developed a procedure to assess off-fault displacement hazards based on probabilistic and numerical simulation approaches. In the probabilistic approach, we constructed strike-slip and reverse-slip PFDHA models from a dataset of Japanese fault displacements. The off-fault components in PFDHA had a probability of non-zero off-fault displacement and an attenuation relationship. In the case of evaluating the site of an important facility, detailed field surveys were performed to collect numerous site-specific information. There is little site-specific data of off-fault displacements in Japan. The trench surveys were performed at off-fault displacement sites from the 2016 Kumamoto earthquake. The two trench sites were selected based on a linear low-coherence zone derived from the InSAR analysis, which emphasizes small-scale displacements. The excavation survey result at one site suggests a shorter recurrence interval than that of the active fault long-term evaluation. We also performed a probabilistic fault hazard analysis (PFDHA) of the trench sites by using the global strike-slip model and Japanese PFDHA models with and without the site-specific data. For the PFDHA results without site-specific data, the difference in the annual rates of exceedance between the global strike-slip and Japanese models increased with increasing fault displacements. This is because of the reduced decrease in the attenuation relationship of Japanese models. The differences in the annual rates of exceedance constrained with the site-specific data are independent of fault displacements due to variation in the probability of non-zero off-fault displacement between the global strike-slip and Japanese PFDHA models. These results suggest that the off-fault PFDHA models have high variability. In the case of PFDHA evaluation with several models, the individual PFDHA components are carefully selected by considering the individual effects. The site-specific short recurrence interval revealed by the trench survey leads to higher annual rates of exceedance.

A novel four-linear cohesive law for the delamination simulation in composite DCB laminates

Large-scale fiber bridging usually presents in the wake of the crack tip in multidirectional composite DCB laminates, resulting in a significant R-curve phenomenon on the fracture toughness. In order to consider the influence of the fiber bridging on the delamination behavior in FE modelling, a novel four-linear cohesive law is proposed in this study, which is physically established based on the realistic failure mechanism during the delamination process. The required parameters in this law can be determined by experiments, expect for the fracture toughness ratio, which is introduced to present the non-linear softening behavior of the bridging fibers in a simple way and make the cohesive law easy to be implemented in FEM. The numerical results predicted by the proposed law have good agreements with the experimental results for two kinds of multidirectional laminates, illustrating the applicability of the new four-linear cohesive law. The advantages of this new cohesive law are the less parameters required to be numerically determined and the simplicity for practical application than existing methods. In addition, the new cohesive law is physical-based rather than a direct superposition by two linear cohesive zone models, which is lack of physical basis.

Collective dynamics of capacitively coupled oscillators based on NbO2 memristors

The dynamics of NbO2-based single and coupled oscillators are comprehensively investigated in this study. For single oscillators, the oscillation frequency is shown to have a strong dependence on the source voltage and load resistance. The range of the frequency modulation can be tuned from 2.1 to 6.8 MHz, while the load resistance is fixed at 3 kΩ. For coupled oscillators, rich and complex dynamics including in- and antiphase locking phenomena are carefully explored by using a mutual capacitor. According to different phase trajectories on the phase plane of both voltages across two devices, the evolution of the source voltage vs coupling capacitance phase diagram is shown with load resistance mismatch. Four coupling regions in the phase diagram are recognized, including a butterfly-shaped coupling zone, a linear coupling zone, a transition zone, and an uncoupled zone. As the load resistance mismatch increases from 1.0% to 3.9%, the linear coupling zone gradually disappears while the butterfly-shaped coupling zone gradually expands. When the load resistance mismatch is larger than 9.5%, the butterfly-shaped coupling zone gradually decreases while the uncoupled zone enlarges significantly.

Common features in the manifestation of natural and induced geodynamic events in the eastern regions of Russia and China

The study of geodynamic processes observed in the Earth’s crust at densely populated and commercially developed areas in the east of Russia and China is of great importance for their sustainable development. The research results available show that not only natural, but also man-made geodynamic events associated with mining operations reflect the global geodynamic processes. Geodynamic events that occurred while mining in impact-hazardous areas allowed to identify some common features in the manifestation of natural and man-made geodynamic events in the eastern regions of Russia and China. Thus, both natural and disastrous technogenic geodynamic events (tectonic rock bursts, induced earthquakes, cracking on the earth’s surface) have positional connection with the linear zones of earth’s crust modern destruction (block boundaries and faults). Existing tectonic faults get re-activated during major geodynamic events, i.e. they get displaced in response to the mining operations. Areas hazardous for manifestation of geodynamic phenomena can be defined by geodynamic zoning method which can be used to draft the development programs for the eastern regions of Russia and China

Improving the dynamics of a synchronous in-phase electric drive in transient modes of synchronization, phasing and control in response of reference signal changes

Synchronous in-phase electric drive is widely used in thermal-imaging and laser scanning systems due to their high accuracy and dynamic characteristics in a wide range of angular velocity control. The purpose of the article is to develop ways to control a synchronous-in-phase electric drive in the modes of synchronization, phasing and control in response of reference signal changes, allowing to improve the dynamic performance of the electric drive and reduce information loss in the scanning system. The method of electric drive phasing that is quasi-optimal in speed has been improved. Recommendations on the organization of transient processes with an abrupt change in the reference signal are formulated. For use in the electric drive control system, a circuit implementation of an impulse frequency-phase discriminator with an extended linear zone in the phase comparison mode has been proposed, it allows to improve the dynamic performance of the electric drive in the modes of synchronization, phasing and control in response of reference signal changes.

Grain-scale distribution of molybdenite polytypes versus rhenium contents: μXRD and EBSD data

AbstractMolybdenite from two porphyry copper mineralisation sites within the South Urals was studied by electron microprobe (EMPA), micro x-ray diffraction (μXRD) and electron backscattered diffraction (EBSD) methods. Elevated contents of rhenium (0.2 to 0.4, sometimes up to 1.1 wt.%) form linear zones from several to tens of micrometres wide and up to hundreds of micrometres long parallel to the elongation of molybdenite flakes. In most cases Re-rich zones are composed of the rhombohedral (3R) polytype of molybdenite, while the rest of the molybdenite flakes with ca. 0.1 wt.% of Re consist of hexagonal (2H) molybdenite. In rare cases Re-rich zones are confined to grain boundaries of molybdenite-2H. It is shown that both μXRD and EBSD are the most appropriate tools to distinguish different polytypes within a single grain of molybdenite.

Continental slope-confined canyons in the Pearl River Mouth Basin in the South China Sea dominated by erosion, 2004–2018

Repeat multibeam bathymetric surveys conducted in 2004, 2005 and 2018 show that seven slope-confined canyons on the continental slope of the Pearl River Mouth Basin, South China Sea, were dominated by large volume, widespread erosion. Erosion volumes were up to 3.4 times greater than deposition volumes. Erosion-dominated areas of the canyons are up to 2.3 times greater than areas dominated by deposition. Average rates of erosion (ranging from 0.7 to 0.8 m/yr) were greater than average rates of deposition (ranging from 0.5 to 0.8 m/yr). In plan view, the erosion-dominated zones exhibit two characteristic shapes: (1) linear, found mainly in upper canyon reaches, distributed predominantly along canyon axes and at the base of eastern canyon walls, and; (2) blocky, found mainly in lower canyon reaches, widely distributed along the steep canyon walls and on lower-canyon interfluves. The deposition-dominated zones are scattered along canyon floors and walls. Seismic reflection data show lateral shifts of canyon fill deposits through time, indicative of longer-term eastward canyon migration. The linear erosion-dominated zones may be attributed to erosive turbidity currents triggered by energetic internal solitary waves shoaling on the shelf. The eastward canyon shifts were likely induced by rapid near-bed eastward currents generated mainly by westward propagating powerful internal solitary waves of depression. The widespread erosion in the deeper canyon areas and interfluves is likely a consequence of slope instabilities associated with the presence of gas hydrates. This study indicates that active sedimentary processes can occur in slope-confined canyons even during sea level highstands. Local, site-specific oceanographic and geological features (e.g., internal solitary waves, gas hydrates) can significantly increase sedimentary activity in and around submarine canyons.

Viscoelastic behavior of silicone/clay nanocomposite coatings

Rubber/clay nanocomposites (RCNs) have attracted an emerging interest from academia and industry alike due to their outstanding tunable properties. The present paper addresses the viscoelastic behavior of silicone/clay systems in order to get an understanding of physical interactions in the RCNs systems as well as making possible interpretation of the effect of nanoparticle shape and surface functionality on viscoelastic behavior of molten RCNs. Rheological behavior determination of silicone/clay composites provides insight into dependency of properties of resulting nanocomposite coatings on processing and preparation conditions. The effect of bare and (3-aminopropyl) triethoxysilane (APTES) functionalized platy and tubular clays on viscoelastic behavior of silicone rubber nanocomposites were investigated by rheometric mechanical spectrometer (RMS). The analysis was set to the strain and frequency sweep tests, where the linear viscoelastic zone of the uncured nanocomposites were determined by dynamic strain sweep and then frequency sweep to probe into the role of dispersion of nanoparticles in silicone matrix. Well-known Han, Cole-Cole and van Gurp-Palmen models were applied to peruse silicone/clay interaction and to find additional information on rheological properties of nanocomposites under the influence of the shape, surface chemistry and content of nanoparticles. The findings depicted the effective role of physical interactions on APTES-functionalized clay on appropriate dispersion of clays throughout silicone matrix. This effect was more obvious in the presence of platelet-like clays in view of improved intercalation and/or exfoliation.

New genetic type of leaching zones in the salts of the verkhnekamskoe salt deposit: hydrochemical, mineralogical and structural indicators

The brine-saturated leaching zone first encountered in the salt rocks of the Verkhnekamskoe Salt Deposit is characterized in detail. It consists of a cavernous nucleus (40×70 m), composed of an aposilvinite syngenite-halite rock with gypsum and kalistroncite, and a recrystallization halo 60–80 m wide, not containing secondary sulfates. Above the leaching zone is a linear zone of weathering and decarbonization of marls above the salt layer. This zone is controlled by the anticlinal crest of the sublatitudinal strike, extending parallel to the Durinsky Trough of the sedimentary-fault nature. The penetration of supra-salt waters into a salt deposit is associated with the manifestation of deformations in the salt mass at its hinge inflection during the formation of the Durinsky deflection in the Early Permian time. The connection of the brines of the investigated leaching zone with infiltration over-salt sulfate-calcium waters was revealed and their place was determined in the general scheme of genetic typification of natural brines and waters circulating in the salt deposit of the Verkhnekamskoe Salt Deposit.