bluuebunny/crossref_metadata_2025 huggingface dataset:
Comprehensive optimisation and comparison of multiphase receiver for dynamic wireless charging system
Authors: Wang Zhiyuan , Cui Shumei , Song Beibei , Han Shouliang , Zhu Chunbo
Published: June 2019

Different configurations of multiphase receiver for 20 kW/20 kHz dynamic wireless charging (DWC) system are comprehensive compared based on multi‐objective (material‐cost and efficiency) optimisation results under multi‐constraint condition. The constraints include total length of receiver, lateral tolerance, resonant voltage of compensation capacitance and fluctuation factor which are the factors may limit the application of multiphase receiver. Each constraint is divided into two cases: strong and weak. So there are sixteen multi‐constraint conditions composed of different constraint cases. Five configurations of two‐phase and four‐phase receiver are studied. The relationships between design parameters and mutual inductance, efficiency and constraints are calculated by analysis of structure configuration and equivalent circuit. In order to improve the rapidness and global optimum of optimisation, a multi‐objective optimisation process based on complete enumeration and Pareto optimality is proposed. Five configurations for 20 kW/20 kHz DWC system are optimised under sixteen multi‐constraint conditions respectively. Four‐phase receiver of hybrid connection is taken as an example to analyse the influence of different constraint values on the optimisation results. The Pareto fronts of different configuration optimisation results are comprehensive evaluated and compared. The optimal configuration under each condition is determined. A 10 kW/20 kHz DWC prototype system is established and the models in optimisation design are verified.
EMI mitigation in switching power converters combining closed‐loop gate drive and chaotic frequency modulation technique
Authors: Cui Tongkai , Ma Qishuang , Xu Ping , Zhang Poming
Published: June 2019

All switching power converters are characterised by inevitable switching actions with relevant interference emissions. The voltage and current transients of power metal oxide semiconductor field effect transistor (MOSFET)/insulated‐gate bipolar transistor are the main sources in switching power converters for both conducted and radiated emissions. In this study, a promising electromagnetic interference (EMI) mitigation method combining the closed‐loop gate drive method and the chaotic switching frequency modulation technique is demonstrated for switching power converters. A chaotic pulse‐width modulation waveform with Gaussian S‐shape switching transients was proposed to achieve remarkable reduced EMI generation at all frequencies. Spectral characteristics of this new switching waveform were investigated by the power spectral density to verify the feasibility of reduced EMI generation. A closed‐loop gate controller was presented to shape the switching transients of power MOSFET into the proposed switching waveform. Circuit tests were carried out in both simulations and experiments. The results validated that the proposed method could achieve remarkable EMI mitigation in switching power converters.
Wireless battery charging control for electric vehicles: a user‐involved approach
Authors: Ouyang Quan , Xu Guotuan , Liu Kailong , Wang Zhisheng
Published: June 2019

This study presents a user‐involved wireless battery charging approach for electric vehicles, which enables the battery to reach the user‐specified state by regulating the charging current provided by a wireless charger with double‐sided inductor–capacitor–capacitor compensation topology. Specifically, an optimal state of charge (SOC) trajectory is first generated through formulating and solving an optimisation issue with the consideration of user demand and operating constraints. Next, a cascade control strategy is proposed to regulate the wireless charger to make the battery track the scheduled charging trajectory. The out loop control designs suitable charging current for SOC trajectory tracking, which can effectively suppress the violation of the charging constraints by on‐line compensating the battery model bias. In the inner loop, a fuzzy proportion–integration (PI) algorithm is proposed to control the wireless charger to provide the charging current designed by the out loop, in which fuzzy logic algorithm is utilised to on‐line tune the PI gains to improve the control performance. Extensive real‐time results demonstrate the effectiveness and promise of the proposed user‐involved wireless battery charging control strategy.
Efficient approach for OS‐CFAR 2D technique using distributive histograms and breakdown point optimal concept applied to acoustic images
Authors: Villar Sebastián A. , Menna Bruno V. , Torcida Sebastián , Acosta Gerardo G.
Published: June 2019

In this work, a new approach to improve the algorithmic efficiency of the order statistic‐constant false alarm rate (OSCFAR) applied in two dimensions (2D) is presented. OS‐CFAR is widely used in radar technology for detecting moving objects as well as in sonar technology for the relevant areas of segmentation and multi‐target detection on the seafloor. OS‐CFAR rank orders the samples obtained from a sliding window around a test cell to select a representative sample that is used to calculate an adaptive detection threshold maintaining a false alarm probability. Then, the test cell is evaluated to determine the presence or absence of a target based on the calculated threshold. The rank orders allow that OS‐CFAR technique to be more robust to the presence of the speckle noise, but requires higher computational effort. This is the bottleneck of the technique. Consequently, the contribution of this work is to improve the OSCFAR 2D on‐line computation with the distributive histograms and the optimal breakdown point optimal concept, mainly from the standpoint of efficient computation. The theoretical algorithm analysis is presented to demonstrate the improvement of this approach. Also, this novel efficient OS‐CFAR 2D was contrasted experimentally on acoustic images.
Design of a six‐phase asymmetrical permanent magnet synchronous generator for wind energy applications
Authors: Gonçalves Pedro F.C. , Cruz Sérgio M.A. , Mendes André M.S.
Published: June 2019

The electromagnetic design of a six‐phase permanent magnet synchronous generator (PMSG) for application in medium/high‐speed wind energy conversion systems (WECS) is studied in this work. The dynamic model and the analytical design process of the six‐phase PMSG are presented and some design aspects, such as the winding configuration and the geometry of the permanent magnets are discussed in order to improve the performance of the generator in both healthy and fault‐tolerant conditions, i.e. when only one set of three‐phase windings is connected to the grid. Finally, several simulation results obtained through finite element analysis are presented in order to validate the proposed design.
Explorer les liens entre agriculture, migration et sécurité alimentaire : une enquête auprès de ménages agricoles diversifiés et multilocalisés du nord-ouest du Nicaragua
Authors: Fréguin-Gresh Sandrine , Padilla Lissania , Pavon Karen , Elizondo Douglas , Cortès Geneviève , Banoviez Urrutia Valentina , Lourme Ruiz Alissia , Dury Sandrine , Bouquet Emmanuelle
Published: June 2019

Cet article présente une enquête menée dans le nord-ouest du Nicaragua, qui vise à comprendre comment les flux d’argent et d’aliments générés par les activités diversifiées et multilocalisées des familles agricoles interviennent dans l’accès aux aliments et dans la perception de la sécurité alimentaire. Dans la région d’étude, l’agriculture familiale est caractérisée par des conditions agro-écologiques difficiles et repose sur la production vivrière et l’élevage bovin. En réponse au manque de revenus, les ménages ont depuis longtemps diversifié leurs activités hors exploitation, localement ou en migration. Cette diversification et cette multilocalisation leur permettent d’obtenir des revenus et des aliments, indispensables à la sécurité alimentaire dans les régions d’origine. Ces flux d’argent et d’aliments se fondent sur des rapports sociaux entre les membres des ménages et au-delà (famille élargie, voisinage, acteurs institutionnels). Pour capter ces flux, le questionnaire d’enquête, composé de trois sections, s’organise autour d’une clef d’identification unique : l’individu. En captant les activités individuelles et les flux de ressources dirigés vers la cuisine familiale, l’enquête propose des possibilités d’analyse de la sécurité alimentaire basées sur la déconstruction des unités classiques d’analyse (résidence, ménage, exploitation). Des communautés de production et de circulation sont alors établies pour pouvoir étudier les stratégies d’approvisionnement de la communauté de consommation, point de départ de l’étude de la sécurité alimentaire. Le questionnaire a été appliqué à 350 ménages dans une région d’étude au nord-ouest du Nicaragua. La collecte s’est faite par questionnaire papier et en entretien face-à-face entre avril et juin 2016. Des entretiens individuels complémentaires ont été conduits entre février et mai 2016. Les données ont été saisies entre juillet et octobre 2016, avant d’être contrôlées, nettoyées et préparées pour les analyses entre juin et octobre 2017 sur le logiciel SPSS. Les métadonnées ont été produites sur NESSTAR.
Sparse and switching infinite horizon optimal controls with mixed-norm penalizations
Authors: Kalise Dante , Kunisch Karl , Rao Zhiping
Published: June 2019

A class of infinite horizon optimal control problems involving mixed quasi-norms of Lp-type cost functionals for the controls is discussed. These functionals enhance sparsity and switching properties of the optimal controls. The existence of optimal controls and their structural properties are analyzed on the basis of first order optimality conditions. A dynamic programming approach is used for numerical realization.
Hydrothermal fluid circulations in the western Pyrenees: new data on stable isotopes, in-situ gas analysis and fluid inclusions
Authors: Barré Guillaume , Elias-Bahnan Alexy , Motte Geoffrey , Ducoux Maxime , Hoareau Guilhem , Laurent Dimitri , Gaucher Eric C.
Published: June 2019

Several fluid circulation events are recorded in the Aquitaine Basin and the Chaînons Béarnais in the Pyrenean belt of southwestern France. Different fluid types are found in all locations studied. The main difference comes from the thermal peak event (rifting), which was more intense in the Chaînons Béarnais close to the exhumed mantle zone. In situ gas analysis associated of fluid inclusions and isotopic (C, O, H, S) analyses show that similar fluids are generated in both systems, although separated by deep structures, e.g. the North Pyrenean Frontal Thrust (NPFT). The Pyrenean tectonic history leads to the compartmentalization of fluid circulations.
Radiobiogeochemical research of the Karakol River basin in the Issyk-Kul region, Kyrgystan
Authors: Ibraeva Kymbat , Kaldybaev Bakyt
Published: June 2019

This paper presents the results of radioecological research of the Karakol River basin in Issyk-Kul region of Kyrgystan. The Karakol River has a snow-glacier feed, the chemical concentration of the water is slightly mineralized and it is of calcium-hydrocarbonate-sulfate type. The concentration of radionuclide was determined in soil, water, river bottom sediments and the city of Karakol. The values of concentrations are varied within the natural regional background, but a significant increase of the specific activity of radionuclides was observed in the estuary zone of the river. The map of the level of the exposure dose of the territory of the city of Karakol was compiled with the help of the computer program "Surfer-12".
Geochemical barriers as structural components of the geochemical systems evolution
Authors: Khaustov Aleksandr , Redina Margarita
Published: June 2019

The term “geochemical barrier” (GCB) has been widely used in the Russian geochemical literature as a key concept of the distribution of elements and substances theory (incl. pollutions)although in the world research practice this term is not particularly represented. The assessment of the functional role of the geochemical barriers in relation to the properties and evolution of the geochemical systems (GCS)is demonstrated.The foundations of Haken synergy, the foundations of self-organization of systems and non-equilibrium (non-linear) thermodynamics of I. Prigogine and his school are used as a methodological framework. From the authors’ point of view, GCB are considered as self-organizing components of GCS, in which physical and chemical processes are activated, leading to the transformation of atomic and molecular structures, chemical associations and individual chemical elements under the impact of active media (processes). They can be the defining phenomenon of the emergence and evolution of GCS. The concept of geochemical barriers is the foundation for technologies that are actively implemented for cleaning and protecting soils, groundwater and surface water, and the geological environment in general.
Modern carbonate formation in low-mineralized flowing waters
Authors: Korolev Eduard , Eskin Aleksey , Khuzin Ilnur , Petrova Dariya , Barieva Enza , Korolev Albert
Published: June 2019

Continental carbonate formation in low-mineralized flowing waters of temperate latitude is rare phenomenon. Taking this into account a study was conducted of crustate and stalactite-like authigenic calcite aggregates formed in the thalwegs of the ravines of the Volga Upland. According to chemical and isotopic analysis, modern carbonates are formed from poorly mineralized, meteoric waters of medium hardness, hydrocarbonate-magnesium-calcium hydrochemical type. It has been established that newly formed carbonate aggregates are characterized by the predominance of lightweight carbon and oxygen in the crystal structure. The osmotic hypothesis of the formation of lime-calcite aggregates is proposed.
Geochemistry of natural waters of the Baydar valley (Crimean Peninsula)
Authors: Nichkova Larisa A. , Novikov Dmitry A. , Chernykh Anatoliy V. , Dultsev Fedor F. , Sigora Galina A. , Khomenko Tamara Yu.
Published: June 2019

The paper discusses the pioneering results of comprehensive hydrogeochemical studies of natural waters of the Baydar valley (southwestern parts of the Crimean Peninsula), whose major aquifers are confined to the upper Jurassic sediments (karst limestone) representing the most important hydrogeological feature of the study area. Fresh and ultra-fresh waters of predominantly bicarbonate calcium composition with total mineralization in the range from 194 to 1137 mg/dm3 are most widespread in the region. The analyzed waters (surface, ground and artesian) differ significantly in chemical composition and their basic characteristics have been arranged in the following patterns: mineralization of 254-832 mg/dm3 and neutral pH (6.98-7.54) for artesian waters; higher mineralization level (up to 1137 mg/dm3) and wide variations of pH values (from 7.18 to 8.31) for ground waters; mineralization from 194 to 288 mg/dm3 and a slightly alkaline pH (between 8.02 and 8.04) for surface waters collected in the Chyornaya river basin and Chernorechensk reservoir. The studied waters display a unique spectrum of trace elements and REE distribution.
Assessment of diameters of karst holes in the design of the main gas pipeline, South Yakutia
Authors: Strokova Ludmila , Ezhkova Aloyna
Published: June 2019

The report describes the local and regional geological factors of the South Yakutia, through which it is planned to build a gas pipeline. On this territory there are the main karstic rocks, with relatively high mineral solubilities: dolomite, limestone and gypsum. These rocks have different dissolution rates and others geological settings. The assessment of the karst holes diameters for the gas pipeline section was made. The measures to protect potentially hazardous sections are suggested, including timely notification about sinkholes.
Water-rock interactions: the formation of an unusual mineral assemblage found in a Siberian coal
Authors: Thompson Leah N. , Finkelman Robert B. , Arbuzov Sergey I.
Published: June 2019

Volcanic ash is regularly found in coal and is particularly common in the Minusinsk coal basin in southern Siberia, Russia. Ash deposits in coal are usually observed in the form of thinly bedded, kaolinite-rich layers called tonsteins. The coal we studied by scanning electron microscopy with an energy dispersive detector contained many of the minerals typically found in tonsteins: kaolinite groundmass, volcanogenic phenocrysts such as K-feldspar, quartz, apatite, and zircon, along with secondary minerals such as galena, sphalerite, and REE minerals. However, in addition to these commonly observed minerals, the groundmass contains a rare calcium-bearing magnesian siderite in roughly equal proportion to the kaolinite. Ca-Mg siderite has only been reported in a few Australian coals and never at these relatively high proportions. The relative levels of K-feldspar, apatite, and quartz are consistent with a parent magma of felsic to intermediate composition. The Ca-rich-Mg siderite appears to have developed late in the diagenetic process, likely as a result of the dissolution of calcic feldspars, micas, and mafic minerals in the acidic peat waters releasing calcium, iron, and magnesium which reacted with carbon dioxide from the decomposing plant matter.
Elemental composition of human hair in different territories of the Crimean peninsula
Authors: Evstafeva Elena , Baranovskaya Nataliya , Bogdanova Anna , Ablialimov Osman , Macarova Anna , Evstafeva Irina , Yaseneva Elena
Published: June 2019

The chemical homeostasis of humans has changed due to global and local anthropogenic impacts on biogeochemical cycles. Their degree is mediated by natural geochemical character of local environments. The elemental composition of human hair and quantitative relation between elements is summary characteristic of biogeochemical environmental conditions. To determine the biogeochemical situation 78 inhabitants from different geographic regions across the Crimean peninsula, cities and rural areas were investigated through the analysis of 28 elements by neutron activation analysis and determination of mercury by atomic absorption spectroscopy. High variety of elemental composition in inhabitants’ hair on different types of territories in the Crimean peninsula was revealed. Comparison with different territories of Russian Federation and Belarus shows both common and specific features. On most part of Russian and the Crimean territories a deficiency of essential elements (Zn, Cu) in human hair is characteristic. At the same time there are significant differences in content of some essential elements (Ca, Fe) and other ones (Th, Ce, Au, U, Ag, Cs) even in the limited Crimean territory. It requires further investigation of factors, which determine the revealed variability.
Geochemical research of asphaltite formation in the Orenburg region
Authors: Zakharchenko Maria , Salihova Irina , Kerimov Vagif
Published: June 2019

The results of the studies of the physicochemical properties and genesis of asphaltites from the deposits of the Orenburg region are considered. Based on the data of a study on the distribution of hydrocarbon biomarkers (n-alkanes, isoprenanes, steranes, and terpanes), it was found that deposit formation occurred in carbonate layers under reducing conditions. The distribution of steranes and terpanes confirmed a sufficient maturity of the asphaltite. The C28/C29 sterane ratio of 0.31 corresponds to Silurian age according to Grantham or to Silurian–Devonian age according to the pregnane coefficient (a ratio of the sum of C21–C22 pregnanes to the sum of C21–C22 pregnanes and C27–C29 regular steranes) of 9.0%. Thus, it is likely that asphaltites from the Ivanovk deposit in the Orenburg region were redeposited in Silurian/Devonian source rock formations.
Mechanisms of arsenite oxidation and arsenate adsorption by a poorly crystalline manganese oxide in the presence of low molecular weight organic acids
Authors: Liang Mengyu , Guo Huaming , Xiu Wei
Published: June 2019

Manganese oxides are considered as one of the effective oxides capable of oxidizing arsenite and reduce the toxicity of arsenic. Since low molecular weight organic acids (LMWOAs) commonly found in nature can act as reducing and chelating agents for manganese oxides, it is particularly important to investigate how these organic acids with different numbers of carboxyl groups like citrate and EDTA affect oxidation and adsorption of arsenic by manganese oxides. In this study, low As(V) adsorption on manganese oxide is slightly enhanced by citrate and EDTA, which results from the increase in active sites via reduction of manganese oxide by LMWOAs. However, citrate and EDTA have different effects on the oxidation of As(III). MnIII/II citrate autocatalytic cycle as a manganese-based redox system decreases As(III) oxidation rate, but EDTA does not yield autocatalysis, which slightly increases the oxidation rate of As(III). Reduction of manganese oxide by EDTA and chelation between Mn(II) and EDTA lead to exposure of more active sites. Our research highlights the different effects of low molecular weight organic acids on the reactions between arsenic and manganese oxide.
Microfluidic measurement of the dissolution rate of gypsum in water using the reactive infiltration-instability
Authors: Osselin Florian , Kondratiuk Pawel , Cybulski Olgierd , Garstecki Piotr , Szymczak Piotr
Published: June 2019

We present an original method for measuring the intrinsic dissolution rate of gypsum. We use a simple microfluidic setup, with a gypsum block inserted between two polycarbonate plates, which is dissolved by water. By changing the flow rate and the distance between the plates, we can scan a wide range of Péclet and Damköhler numbers, characterizing the relative magnitude of advection, diffusion and reaction in the system. We find the dissolution to be unstable, with a formation of a characteristic fingering pattern. The dissolution rate can then be calculated from the initial wavelength of this pattern. Alternatively, it can also be estimated from the time it takes for the gypsum chip to get completely dissolved near the inlet channel. The method presented here is general and can be used to assess the dissolution rates of other minerals.
The effect of a phosphonate-based antiscalant on the morphology and precipitation kinetics of gypsum: The Red Sea – Dead Sea project
Authors: Reiss Amit G , Ganor Jiwchar , Gavrieli Ittai
Published: June 2019

The proposed plan for the 'Red Sea – Dead Sea project' has raised concerns that the surface water of the Dead Sea would turn white due to gypsum precipitation. The occurrence of such an event would depend on the precipitation kinetics and the morphology of the precipitating crystals. Batch experiments were conducted to study the effect of a phosphonate-based antiscalant on the precipitation kinetics and morphology of gypsum under the conditions of this project.

Addition of the antiscalant was found to increase the induction time by a factor of 1.2-5 over the entire range of Dead Sea – Seawater mixtures investigated, depending on brine composition. Once nucleation occurred, the antiscalant also slowed the crystal growth by a factor of 1.2-3. However, when the solutions were seeded with gypsum, the rate of crystal growth with and without antiscalant were similar, within uncertainty. More crystals precipitated from unseeded solutions with no antiscalant and the crystals were smaller and less tabular than those precipitated from unseeded solutions with antiscalant.
Role of water/rock interaction in the formation of ore-bearing solutions and deposition of hydrothermal ore, Sadon Mining District, North Caucasus Mountains, Russia
Authors: Borisov Michael , Bychkov Dmitry , Volkova Mariya , Shvarov Yury
Published: June 2019

REE distribution patterns of the ores and host rocks of the Dzhimidon vein lead-zinc deposit (North Caucasus, Ossetia, Sadon mining district, Russia) have been analyzed to elucidate the source(s) of hydrothermal ore deposits. Two types of prevailing rocks are involved in ore formation - Paleozoic granites (the main ore-hosting rocks at the majority of deposits) and Precambrian schists (specific only the for host rocks of the Dzhimidon deposit). The source of ore components tends to be complex and includes host rocks in variable proportions that could be characterized by REE distribution in ores. Interaction of water with combined sources was thermodynamically modeled. Critical differences were found in the ore-forming models, with variable sequence and rock proportions during interaction with barren fluid.
The influence of land use on nitrogen and sulfur turnover: a microbial approach
Authors: Espín Yolanda , Sanz Guillermo , Valiente Nicolás , Menchén Alfonso , Toledo Beatriz , Álvarez-Ortí Manuel , Seseña Susana , Gómez-Alday Juan José
Published: June 2019

Saline lakes are subject to numerous environmental impacts related to human activities. Pollution is one of the major threats to water bodies, since it produces the increase of nitrogen and sulfur contents, changing the chemical and biological conditions of the ecosystem. Microbially mediated redox processes exert a fundamental control on nutrient and contaminant turnover. Therefore, the aim of this study was to determine the influence of land use on the microbial communities responsible for N and S turnover in the lacustrine sediments from Pétrola Lake (SE Spain) disturbed by anthropogenic activities (agriculture, farming, mining, and wastewaters). To reach this goal, chemical and molecular tools (sequencing of 16S rDNA gene) were applied. The results showed the influence of land use on the chemistry and microbial community structure of the sediments from the saline lake. Compared to natural conditions, wastewater and mining showed the largest differences in terms of microbial structure as a result of salinity. These findings provide better understanding of how land use affects the water chemistry and the abundance of organisms responsible for nutrient turnover.
Impact of filtration artifacts on the seasonality of river waters chemical composition
Authors: Shulkin Vladimir , Bogdanova Natalia , Lutsenko Tatyana , Yurchenko Svetlana
Published: June 2019

The difference in concentration of filterable trace metals, macro ions, nitrate and dissolved organic carbon (DOC) after capsule and membrane 0.45 µm filters was studied at the seasonal sampling of the typical medium size boreal Razdolnaya River, Far East of Russia. Trace metals showed notable decrease after membrane filtration compared with capsules, though concentrations of macro ions, nitrates and DOC were equal. Clogging of membranes with subsequent retention of coarse colloids was suggested as a reason for this difference. In summer the dissimilarity in concentration grew in order Cu < Zn < Ni, Cd < Mn < Fe reflecting a significant role of coarse colloids in the pool of filterable forms for Fe and Mn. In winter, retention of Mn was declined due to input of ionic forms from redox cycle. Floods are the periods with the most notable increase of coarse colloids content and maximum bias in the determination of filterable trace metals if frontal membrane filtration is being used.
Geochemistry of the frost mound’s ice in the Sentsa River Valley (Oka plateau, East Sayan Mnt.)
Authors: Alexeev Sergey , Alexeeva Ludmila
Published: June 2019

The authors have studied the chemical composition of ground ice sampled from the frost mounds located in the unconsolidated sediments of the Sentsa River valley (Oka plateau, Eastern Sayan Mountains) to reconstruct the formation history of these cryogenic creations. Numerous frost mounds of various sizes are mainly composed of clayey silts with interlayers of heavy silts and ice lenses. It is found that the chemical composition of the melt ice sampled from lenses and layers within the frost mounds is HCO3 Ca, SO4-HCO3 Ca and NH4-HCO3 Ca with 6.5–15.6 mg/L salinity and pH = 5.6÷6.1. Whereas, the salinity of the melt texture-forming ice sampled from the ice with fractions of enclosing clayey silts was much higher: from 50 up to 792.5 mg/L. River and lake water is ultra-fresh HCO3 Ca with 99–132 mg/L salinity. The geochemical features of ground ice depend on a water-rock interaction, a presence of organic matter in the unconsolidated sediments and a repeated volcanic activity. The frost mounds are confined to a lacustrine sediments area in the backwater zone that was formed by the Late Pleistocene end moraine. The frost mounds have probably a mixed segregation-injection genesis.
Evolution of groundwater chemistry in coastal aquifers of the Northern Dvina basin (NW Russia)
Authors: Malov Alexander
Published: June 2019

The specific objective of the study is to clarify the sources and characteristics of groundwater chemistry in coastal aquifers of the Northern Dvina basin. It has been established that the chemical composition of fresh water evolves in the direction (Ca-Mg-HCO3) - (Na-HCO3) - (Na-Cl). It is due to successive replacement of the process of calcite dissolution in the recharge area on the watershed i) by the process of hydrolysis of sodium aluminosilicates in the transit zone and ii) by the processes of mixing fresh water with salt water and brines, cation exchange of alkaline earth elements with alkaline elements and dissolution of gypsum near discharge areas at the seashore and in paleovalleys. In the brackish and salty waters the Na/Ca ratio is reduced to 1-4. This indicates that in the aquifers there are other sources of Ca, in addition to the dissolution of gypsum. The most probable process is the hydrolysis of Ca-aluminosilicates, which indicates a significant time of water-rock interaction. The “brackish1” water with TDS 5-6 g·L-1, is particularly distinguished by the degree of modification due to water-rock interaction.
The origin of the warm groundwater near Lake Mývatn, NE Iceland, traced by stable isotopes
Authors: Óskarsson Finnbogi
Published: June 2019

The origin of the warm groundwater which feeds Lake Mývatn is unknown, but it has been affected by volcanic episodes as well as geothermal activity and utilisation. In this contribution stable isotopes of hydrogen (2H), oxygen (18O), sulphur (34S), chlorine (37Cl) and strontium (86Sr and 87Sr) in 20 groundwater and effluent samples from the Lake Mývatn area are used to constrain the origin of the warm groundwater. The results suggest that the warm groundwater is partly formed by mixing with geothermal effluent water and partly by mixing with geothermal steam.
Experimental study on the effect of salinity change on Fe and Cr removal from estuary water
Authors: Luo Ximing , Lang Hang , Wang Wenjuan
Published: June 2019

Freshwater mental contaminants which in the estuary tend to precipitate into intertidal surface sediments during freshwater-seawater mixing because of heavy water chemical reaction. The impacts of ferric hydroxide on the removal rate of Cr with increasing pH and salinity were conducted by laboratory simulation experiment. The removal rate of Cr by ferric hydroxide decreased with increasing pH from river water to seawater in the estuary; this is because pH changed the Zeta potential of ferric hydroxide. And with increasing salinity, the removal rate of Cr by ferric hydroxide firstly decreased and then increased. On the hand, Na+ entering the sliding surface, which could improve Zeta potential and stability of ferric hydroxide colloid, which leads to the amount of Cr removal by colloid aggregation decreased. On the other hand, there was competitive adsorption between Cland CrO42-/HCrO4-. In this study, Fe was the key factor of heavy metal Cr distribution with pH change.
Hydrothermal alteration of sediments in the high-temperature reaction zone at Central Hill of Escanaba Trough, Gorda Ridge
Authors: Galin Konstantin , Khakhina Alexandra , Kurnosov Victor , Konovalov Yurii
Published: June 2019

In sediments from Holes ODP 1038A and 1038H, drilled near the hot springs at Central Hill, Escanaba Trough (Gorda Ridge), redistribution of major elements occurs during the water-rock interaction. Contents of Si, Fe, Mg, Ca, Na and K have changed in altered sediments. In this process, an increase/decrease in contents of major elements in altered sediments shows a decrease/increase in their contents in fluids. The irregular distribution of major elements in altered sediments resembles a layer pie, which reflects the existence of lateral flows of hydrothermal fluids.
Chemical and isotopic compositions of boron in the geothermal waters in the Xianshuihe Fault Zone, Western Sichuan Province, China
Authors: Yuan Jianfei , Xu Fen , Liu Huizhong
Published: June 2019

In this study, boron contents and boron isotopic compositions of geothermal waters are first reported in the Xianshuihe Fault Zone (XSHFZ), Western Sichuan. The results show that boron contents of geothermal water are 0.03-10.50 mg/L, and the δ11B values range from -6.75 to 4.01‰, indicating the non-marine origin. The δ11B values and Cl/B molar ratios reveal that boron in geothermal water is mainly leached from reservoir rocks, such as carbonate and igneous rocks. Comparing it with other geothermal systems in the Yunnan-Tibet Geothermal Belt, we found that the samples from XSHF have the largest variations of Cl/B molar ratio and the intermediate δ11B values.
Chemical weathering fluxes from Paramushir volcanic island (Kuril Island arc, Russia)
Authors: Kalacheva Elena , Kotenko Tatiana , Voloshina Ekaterina
Published: June 2019

The rates of the chemical erosion for Paramushir Island, north Kuril Arc, were studied. The rates of the chemical erosion for Paramushir Island, north Kuril Arc, were studied. They were based on the results of the flow rate measurements and chemical analyses of 35 river’s water, sampled in July 2017. The silicate weathering fluxes caused by the subsurface thermal and two different types of surface waters (acid SO4 and near-neutral Na (Ca)-HCO3) of Paramushir have been estimated as 1095±200, 203 ±100 and 64 ± 20 t/km2/year, respectively. The total chemical weathering flux for Paramushir Island is estimated as 120± 40 t/km2/year.
Laboratory leaching tests to investigate mobilisation of metals within engineered geothermal reservoirs
Authors: Rochelle Christopher , Kilpatrick Andrew , Osvald Máté , Szanyi János , Medgyes Tamás , Kóbor Balázs
Published: June 2019

Combining geothermal energy utilization with the extraction of metals in a single interlinked process offers a way to improve the economics of engineered geothermal systems. Here we describe laboratory experiments used to assess the effectiveness of a range of leaching fluids by quantifying metal release from various mineralised rocks. The main findings of this study include: enhanced mobilisation of metals typically found in sulphide minerals (Pb, Zn, Cu), lesser mobilisation of some critical elements (such as Co, Sr and W), and the efficacy of organic additives in mobilising metals.
Secondary minerals in the geyserites of the Geysers Valley (Kamchatka)
Authors: Sergeeva Anastasia , Kiryukhin Alexey
Published: June 2019

Secondary minerals assemblages that are deposited from thermal solutions at the top of geysers (Velikan, Bolshoy) were investigated. It is established that assemblages are represented mainly by opal and high-silica zeolites (mordenite and heulandite). As conditions of feeding hydrothermal reservoir change, minerals of the kaolinite group and smectites may appear.
Theoretical evaluation of iodine and selenium speciation in the natural waters of iodine-deficient territories
Authors: Kolmykova Liudmila , Korobova Elena , Ryzhenko Boris , Cherkasova Elena
Published: June 2019

Water migration of iodine, selenium are in many cases directly related to manifestation of thyroid pathologies, in particular, the endemic goiter. The main aim was to evaluate species and conditions of migration of these elements in natural waters from different water-bearing rocks in areas with a natural iodine deficiency. Evaluation of iodine and selenium species in aqueous solutions has been carried out by thermodynamic modeling basing on chemical composition of 81 water samples taken in the Bryansk region in the period of 2015-2017. The study has showed that the predominant species of iodine in the natural waters is iodide-ion (89%), which may also associate with typomorphic ions (Ca, Mg, Na, K, Sr) forming mineral complexes with them. In the latter state iodine may be removed from solution by fixation on a carbonate barrier. Selenium dominates in natural waters as hydroselenide ion (91%). In the presence of a significant amount of iron, this trace element may form the FeSe mineral phase which may be fixed in reduction conditions.
Time evolution of groundwater quality in Dehui City
Authors: Wei Hongyang , Liang Xiujuan
Published: June 2019

The unreasonable development and utilization of groundwater in Dehui City, China, has resulted in poor groundwater quality conditions. Based on the collection of a large amount of groundwater chemical data and hydrogeological data collected by Dehui City from 1992 to 2015, this paper uses hydrogeological analysis, graphic and other methods and ArcGIS toolbox to analyze the groundwater quality of this City. The study shows that the concentration of groundwater chemical components in the vicinity of the Songhua River is decreasing with time, and the concentration of groundwater chemical components in other regions is increasing with time. The increase of chemical concentrations are affected by human activities and water-rock interaction. The decrease of groundwater chemical concentration in Songhua River area is caused by the mixing between dilute river water and groundwater.
Substantiation of the rock massif permeability based on packer tests
Authors: Neuvazhaev Georgii , Rastorguev Alexandr
Published: June 2019

There are uncertainties, concerning the hydraulic properties used in groundwater flow models while constructing them. This article shows the ranges of changes in hydraulic properties and their optimization for a groundwater flow model in a heterogeneous geological environment of the Nizhnekansky massif.
Continuous-flow membrane filtration (CFMF) as a new method to study the narrow size fractions of colloidal dimension
Authors: Alekhin Yury , Ilina Svetlana , Ivleva Elena
Published: June 2019

In addition to the cascade filtering method, a new method of continuous-flow gel filtration (CFMF gel filtration) without replacing the filter septum has been developed and tested. The results of narrow size fractions separation from water samples with a high content of colloids (cascade filtration and continuous filtration) and the study of their migration with microelements are presented. An experimental investigation of the joint migration of a large number of elements (up to 40-60) and organic matter in continental waters demonstrates the high prospects for the methods to establish stable geochemical associations of trace elements adsorbed on colloids.
81Kr dating – A tool for finding and studying paleogroundwater
Authors: Jiang Wei , Dong Xi-Ze , Hu Shui-Ming , Lu Zheng-Tian , Ritterbusch Florian , Yang Guo-min
Published: June 2019

The study of paleogroundwater on a timescale of several thousands to a million years is interesting both in terms of understanding the aquifer system itself and water resource management. It may also provide valuable information about paleoclimate. 81Kr is an ideal age tracer for paleogroundwater up to 1.3 million years old. Recent developments in the Atom Trap Trace Analysis method have made 81Kr dating available to the earth science community at large.
The role of unsaturated zone in estimating groundwater recharge in arid and semiarid areas as depicted by geochemical tracers
Authors: Huang Tianming , Ma Baoqiang , Long Yin , Pang Zhonghe
Published: June 2019

In arid and semiarid area, the recharge rate is relatively limited and the unsaturated zone (UZ) is commonly thick. The moisture in the UZ may represent the water infiltrating from precipitation during the past decades to thousands of years. Therefore, the multiple geochemical tracers in soil moisture, including Cl (chloride mass balance), 3H (tritium peak displacement), NO3, 2H, 18O, can be used to estimate diffuse recharge rate and related recharge characteristics. Based on 45 UZ profiles with maximum depth of 62 m in the Ordos Basin in NW China, a typical arid and semiarid area, we has used multiple geochemical tracers to study the following recharge informations: (1) reconstruction of groundwater recharge history, (2) determination of groundwater recharge mechanism, and (3) assessment of impact of vegetation changes on groundwater recharge. The results show that the soil texture (epically the shallow soil), vegetation and precipitation mainly control the recharge rate. This study also found that shallow groundwater in arid and semiarid areas is often not in equilibrium with near-surface boundary conditions. To estimate present recharge information, the UZ must be considered. The whole recharge process from precipitation to groundwater cannot be well understood unless the UZ have been included in arid and semiarid areas.
Chemical weathering of a granitic watershed: coupling Lithium isotopes and reactive transport modeling, preliminary results
Authors: Millot Romain , Tremosa Joachim , Négrel Philippe
Published: June 2019

In the present study, we report lithium concentrations and Li isotopic compositions for different samples within a granitic watershed (Margeride, France). We investigate unweathered bedrock and samples displaying different stages of weathering in order to characterize Li isotopic fractionation. This was achieved by coupling lithium isotope geochemistry and reactive transport modeling during granite weathering at the scale of this watershed. The following manuscript reports methodology and the preliminary data.
Anthropogenic N – A global issue examined at regional scale from soils, to fungi, roots and tree rings
Authors: Savard Martine M. , Bégin Christian , Laganière Jérôme , Martineau Christine , Marion Joëlle , Stefani Franck O.P. , Séguin Armand , Smirnoff Anna , Bergeron Jade , Morency Marie-Josée , Paré David
Published: June 2019

Globally increasing anthropogenic airborne emissions of reactive nitrogen (N) generate several environmental issues that require investigating how N accumulation modifies the N cycle. Tree-ring δ15N series may help understanding past and current perturbations in the forest N cycle. Although several studies have addressed this issue, most of them were of local scale or based on short δ15N series. The development of this environmental indicator however would benefit from examining, at the regional scale, the relationships of long tree-ring series with soil N biogeochemical processes. Here we explore these links for tree stands of the oil-sands region in northern Alberta, and the coal-fired power plants region in central Alberta, Canada. We characterize the tree-ring δ15N trends, the N modification rates and bacterial and fungal communities of soil samples collected in the immediate surrounding of the characterized trees. The dataset suggests that specific soil pH, and N-cycling bacterial and fungal communities influence tree-ring δ15N responses to anthropogenic emissions, correlating either directly or inversely. Overall, tree-ring δ15N series may record changes in the forest-N cycle, but their interpretation requires understanding key soil biogeochemical processes. «In nature nothing exists alone», Rachel Carson.
Gas chromatography-mass spectrometry analysis andin vitrobiological studies on fixed oil isolated from the waste pits of two varieties ofOlea europaeaL.
Authors: Abdelrahman Muna Hayder , Hussain Reem Osama , Shaheed Dhulfiqar Sami , AbuKhader Majed , Khan Shah Alam
Published: June 2019

Olive oil isolated from the fruits of theOlea europaeaL. is an important part of Mediterranean diet. It is known for its diverse biological actions. Furthermore, a little amount of fixed oil and other bioactive components can also be extracted from the olive seeds which are considered as byproduct of olive oil extraction. Therefore, this study was designed to analyze the fatty acid composition and to performin vitrobiological studies on fixed oil isolated from olive seeds. The fixed oil was isolated from the olive seeds of Syrian and Greek black olive fruits by using Soxhlet apparatus. The purity was checked by measuring its refractive index. Composition of two isolated oils and a commercially available virgin olive oil was determined by preparing their Methyl esters (FAME) followed by GC-MS analysis. Variousin vitroassay methods were used to investigate activities such as antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), cytotoxic activity by using Brine shrimps lethality bioassay and antimicrobial activity against two bacterial strains;Staphylococcus aureusandEscherichia coliby agar well diffusion method. GC-MS analysis revealed that the two isolated oils differ quantitatively in chemical composition with oleic acid identified as the major chemical constituent (62.6% and 73.56%). Both the fixed seed oils showed a concentration dependent DPPH radical scavenging activity ranging from 8 to 76% inhibition. The oils also exhibited excellent cytotoxic activity but no antimicrobial activity was observed. The chemical composition of the isolated fixed olive seed oil is found to be almost similar to the commercially available fruit olive oil. The fixed oil from the seeds of olive fruits possesses useful biological actions. Further studies are needed to isolate and quantify their bioactive constituents.
RECOMBINANT AND PLASMA FVIII SHARE EPITOPES RECOGNIZED BY A PANEL OF MONOCLONAL AND POLYCLONAL ANTIBODIES
Authors: Pancham N , Dumas M , Madant M S , Esmon P C , Voehrinqer V
Published: June 2019

A panel of neutralizing and nonneutralizing monoclonal and polyclonal antibodies raised against human plasma FVIII and human recombinant FVIII was employed in Western blotting, activity inhibition and two-site ELISA studies to investigate structural similarities between recombinant FVIII (r-FVIII) and plasma FVIII (p-FVIII). The monoclonal antibodies were obtained either commercially or produced in-house and react with either the 90kd, 80kd or B-region polypeptides. Some antibodies were raised to FVIII synthetic peptides. Rabbit polyclonal antibodies were obtained from either r-FVIII or p-FVIII immunizations. Recombinant FVIII and p-FVIII were compared either as intact molecules or following thrombin digestion by immunoblots after SDS gradient PAGE. Combinations of antibodies were used in two-site ELISA. Activity inhibition was evaluated by one-stage clotting or in FXa generation assays. Recombinant FVIII and p-FVIII responded similarly to these antibodies in all of the immunotechniques used. Collectively, these results indicate that using this approach r-FVIII and p-FVIII display similar structural and functional characteristics.
ENZYME LINKED IMMUNOASSAY (ELISA) FOR FACTOR VIII ANTIGEN
Authors: Váradi K , Kárpáti J , Elödi S
Published: June 2019

A two site ELISA test was developed for measuring factor VIII antigen (FVIIIsAg). The assay is based on two antibodies developed in a non-haemophilic and in a severe haemophilia-A patient, respectively. The IgG fraction prepared from the non-haemophilic plasma was used for coating, and the IgG isolated from the haemophilia-A plasma was labelled with horse-radish peroxidase

FVIII:Ag and FVIII activity was measured in 28 healthy blood donors and in 41 haemophilia-A patients. The normal range for FVIIIcAg was 40 - 180 %, the correlation coefficient between FVIII:Ag and FVIII activity assays was 0.8. The sensitivity of the assay ranges between 0.005 - 0.2 U/ml FVIII:Ag. In 18 cases of severe haemophilia-A FVIII:Ag was not detectable. In 3 out of 23 mild haemophilia-A cases FVIIIrAg was significantly higher, then FVIII activity, indicating CRM variants of the disease. Due to the high sensitivity of FVIII:Ag detection, the assay appears to be suitable for prenatal diagnosis