bluuebunny/crossref_metadata_2025 huggingface dataset:
Receiving‐coil structure reducing stray AC resistance for resonant coupling wireless power transfer
Authors: Umetani Kazuhiro , Honjo Toru , Koyama Takahiro , Ishihara Masataka , Hiraki Eiji
Published: June 2019

Resonant inductive coupling wireless power transfer is widely known to be a possible convenient power supply method for the small mobile apparatus. However, the limited receiving‐coil size tends to lower the efficiency and limit the output power owing to the small mutual inductance and comparatively large stray alternating current (AC) resistance of the receiving‐coil. This study mitigates this issue by proposing a novel receiving‐coil structure. This proposed structure comprises a coil and a drum core with a thin axis. The coil is wound on the axis to form a single winding layer. The proposed structure can reduce stray AC resistance by suppressing the proximity effect and reducing the wire length without deteriorating the mutual inductance significantly. Therefore, better efficiency and larger output power can be achieved. Simulations and experiments were performed to verify the proposed structure. Consequently, both simulations and experiments supported the reduction in AC resistance compared to the conventional structure. Furthermore, the experiment revealed improvements by the proposed structure in both efficiency and output power. These results support the effectiveness of the proposed structure for wireless power transfer to small mobile apparatus.
Modified amplitude adaptive control algorithm for power quality improvement in multiple distributed generation system
Authors: Kewat Seema , Singh Bhim
Published: June 2019

This study deals with the modified amplitude adaptive notch filter (AANF)‐based control algorithm for managing the generated power from different energy sources in an autonomous microgrid. In this study, the autonomous microgrid consists of a wind energy conversion system, photovoltaic array and a storage battery. The main objective of the proposed modified AANF (MAANF)‐based control algorithm is to control the flow of active and reactive powers among the different energy sources and the load, along with the regulation of the point of common coupling (PCC) voltages and mitigation of the source current harmonics. The advanced features of proposed control algorithm are the DC‐offset rejection from the input signal and fast frequency estimation, which enable the MAANF control algorithm to rapidly and accurately estimate the fundamental components of the distorted load currents. Therefore, the estimated reference source currents remain immune to the DC offset and various harmonic currents. The active power balance is achieved by regulating the DC‐link voltage using a bidirectional DC–DC converter, which is connected between the DC link of the voltage source converter and a storage battery. Test results have validated the control algorithm under various steady‐state and dynamic operating conditions.
LL‐delta structure for CS featuring high‐PTC
Authors: He Guangming , Chen Qianhong , Ren Xiaoyong , Zhang Zhiliang
Published: June 2019

Aiming to improve the power transfer capability and efficiency of contactless sliprings (CS), LL‐delta structure for rotary transformer is proposed. Compared with the conventional UU structure, the effective cross‐section of magnetizing flux for LL structures are increased, resulting in higher coupling coefficient (k), mutual inductance (M) and associated improved power transfer capability and efficiency, without the burden of size. The finite element analysis is performed and demonstrates that the power transfer capability of the proposed LL‐delta structure is about 1.88–5.76 times larger than that of UU structure, and about 1.55–1.61 times larger than that of LL‐basic structure. Three rotary transformers with UU, LL‐basic and LL‐delta structure are fabricated along with the comparative experiments. Measured results indicate that the proposed LL‐delta structure has the largest product kM. With the same exciting current and the load quality factor, 2.06 kW output power is picked up for CS with LL‐delta structure, whereas 1.08 kW for UU structure and 1.36 kW for LL‐basic structure. The maximum efficiency for CS with LL‐delta structure is 96.97%, which is about 0.7% higher than that of UU and LL‐basic structures. The simulation and experimental results verify the effectiveness of the proposed structure.
New tri‐switching state non‐isolated high gain DC–DC boost converter for microgrid application
Authors: Maroti Pandav Kiran , Al‐Ammari Rashid , Bhaskar Mahajan Sagar , Meraj Mohammad , Iqbal Atif , Padmanaban Sanjeevikumar , Rahman Syed
Published: June 2019

High efficiency is an important requirement from DC–DC converter in DC microgrid system when integrated with renewable energy sources. This study proposes a new tri‐switching state non‐isolated high gain boost converter for 400 V DC microgrid applications. The proposed converter developed by modifying the conventional boost converter with advantageous features such as; high‐voltage gain operation with two different duty pulses to overcome the restriction of high duty ratio and continuous input current. Moreover, semiconductor components in the proposed converter are subjected to reduced voltage stress for a shorter duration when compared to conventional existing topologies. Steady state (with and without non‐idealities consideration) and performance analysis are presented to validate the viability of the proposed converter for high gain operation in grid‐connected systems. For experimental validation, a prototype model of the proposed converter is developed for 31 V/400 V, 500 W and operated at 50 kHz switching frequency. The converter is tested for a power range of 100–500 W for two different duty range (case: 1–k1 kept fixed and k2 is varied, case: 2–k2 kept fixed and k1 is varied) to validate the consistency in output voltage. Hardware results obtained validates superior performance and higher efficiency compared to conventional existing topologies.
Proactive frequency control based on ultra‐short‐term power fluctuation forecasting for high renewables penetrated power systems
Authors: Wen Shuli , Wang Yu , Tang Yi , Xu Yan , Li Pengfei
Published: June 2019

The rapidly increasing penetration of renewable energies has introduced severe challenges to power system frequency controls due to the highly intermittent and uncertain power output of renewable energies. This study proposes a proactive frequency control method to control traditional synchronous generators in advance in anticipation of sudden power fluctuation. Therefore, the frequency deviations can be well mitigated by such early‐acted control signal. In order to obtain this new control reference, an ensemble‐forecasting model based on the extreme learning machine algorithm is designed to predict ultra‐short‐term power fluctuations, which serves as an extra signal for automatic generation control. The proposed method was verified on an equivalent model of the Singapore power system with various types of generations and loads. The simulation results clearly demonstrate the accuracy of the forecasting model and the advantages of the proposed control method. The proposed method can also reduce the frequency charging/discharging of energy storage systems, which can effectively extend their lifetime.
Magnetic loss measurement of surface‐mounted permanent magnet synchronous machines used in explosive environments
Authors: Yogal Nijan , Lehrmann Christian , Henke Markus
Published: June 2019

High energy‐efficient permanent magnet synchronous machines (PMSMs) with low manufacturing costs and easy controllability are in high demand for the automotive and aerospace industries and in explosive environments (hazardous areas) like mines and the petrochemical industries. In explosive environments, the high surface temperature of PMSMs, due to magnetic losses and the irreversible demagnetisation of permanent magnets (PMs), could be a source of ignition leading to explosions. Therefore, this paper presents magnetic losses of a PMSM, which will help engineers to design robust machines with a high tolerance to explosive environments. Analytical calculations and finite element method (FEM) simulations of the magnetic losses of a PMSM are presented and compared with measured values from testing a PMSM.
First light of engineered diffusers at the Nordic Optical Telescope reveal time variability of the optical eclipse depth of WASP-12b
Authors: von Essen C. , Stefansson G. , Mallonn M. , Pursimo T. , Djupvik A. A. , Mahadevan S. , Kjeldsen H. , Freudenthal J. , Dreizler S.
Published: June 2019

We present the characterization of two engineered diffusers mounted on the 2.5-meter Nordic Optical Telescope, located at Roque de Los Muchachos, Spain. To assess the reliability and the efficiency of the diffusers, we carried out several test observations of two photometric standard stars, along with observations of one primary transit observation of TrES-3b in the red (R band), one of CoRoT-1b in the blue (B band), and three secondary eclipses of WASP-12b (V band). The achieved photometric precision is in all cases within the submillimagnitude level for exposures between 25 and 180 s. Along with a detailed analysis of the functionality of the diffusers, we add a new transit depth measurement in the blue (B band) to the already observed transmission spectrum of CoRoT-1b, disfavoring a Rayleigh slope. We also report variability of the eclipse depth of WASP-12b in the V band. For the WASP-12b secondary eclipses, we observe a secondary depth deviation of about 5σ, and a difference of 6σ and 2.5σ when compared to the values reported by other authors in a similar wavelength range determined from Hubble Space Telescope data. We further speculate about the potential physical processes or causes responsible for this observed variability.
High subcritical water-rock interaction for the formation of ferric minerals, in the absence of oxygen, UV light and microorganisms
Authors: Bassez Marie-Paule
Published: June 2019

The formation of ferric minerals on the anoxic early Earth is usually explained with the action of microorganisms or UV light in acidic conditions. Results show that amorphous and crystalline ferric oxides and silicates can form in the absence of oxygen, microorganisms and UV light, when rocks, located in the upper crust of the Earth until ca 1 km depth, contain ferrous silicates which interact with water called high subcritical, at 300-350 °C and 10-25 MPa. This conclusion is established following the analyses of Eh-pH diagrams for the Fe-H2O system and solubility diagrams for quartz and amorphous silica. It is shown that water below the critical point and not above can lead to the formation of ferric iron in geological terrains on Earth and extraterrestrial objects where anoxic alkaline high subcritical water reacts with rocks containing ferrous silicates.
Low-enthalpy thermal waters within Khoja-Obi-Garm field (Republic of Tajikistan)
Authors: Demonova Anna , Kharitonova Natalia , Bragin Ivan , Chelnokov Georgiy , Ivanov Vladimir
Published: June 2019

This paper presents data on the composition of the low-enthalpy thermal waters from the unique Khoja-Obi-Garm field located at the central part of the southern slope of the Gissar Range, in the gorge of the Khoja-Obi-Garm River, at an altitude of 1740-1960 meters. In this place, the eponymous SPA-center was built. Groundwaters from springs and boreholes of Khoja-Obi-Garm SPA has temperatures from 57 to 93°C, high pH (up to 8) and low TDS (less than 0.5 g/l). The estimated subsurface temperatures for the same thermal waters vary from 140°C to 156°C and 193-197°C based on the silica and K/Na geothermometer temperatures consequently. These waters belong to Na–SO4–HCO3 type with high content of H2SiO3 (~140 mg/l), F (up to 18 mg/l) and Rn (up to 814 Bq/l). Thermodynamic speciation indicated that these groundwaters are supersaturated with clay minerals and low-temperature zeolites and undersaturated with carbonate and main alumosilicate minerals.
Pressurized fluid flow within the mechanical stability domain of fault zones in shale
Authors: Donzé Frédéric-Victor , Tsopela Alexandra , Guglielmi Yves , Henry Pierre , Gout Claude
Published: June 2019

Fracture interaction mechanisms and reactivation of natural discontinuities under fluid pressurization conditions inside fault zone can represent critical issues in risk assessment of caprock integrity. A field injection test, carried out in a damage fault zone at the decameter scale i.e. mesoscale, has been studied using a Distinct Element Model. Considering the complex structural nature of a fault zone, the contribution of fracture sets on the bulk permeability has been investigated during a hydraulic injection. It has been shown that their orientation for a given in-situ stress field plays a major role. However, if homogeneous properties are assigned to the fracture planes in the model, the limited irreversible displacements cannot be reproduced. Despite these limited displacements (40 µm maximum), the transmissivity increased by a factor of 10-100. These results provide insights in fracture controlled permeability of fault zones depending on the geometrical properties of the fractures and their resulting hydro-mechanical behavior for a given in–situ stress field.
Thermodynamic equilibria of tailings dump pond water of Sherlovaya Gora tin-polymetallic deposit (Transbaikalia)
Authors: Eremin Oleg , Rusal Olga , Solodukhina Maria , Epova Ekaterina , Yurgenson Georgy
Published: June 2019

The potential toxic elements (Be, U, As, Cd, Pb, Sb, Bi) were detected for mine landscape of Sherlovaya Gora tin-polymetallic deposit. Thermodynamic calculation of equilibrium for tailings dump pond water was carried out by means of “Selektor” program complex based on Gibbs free energy minimization algorithm at 25°C and 1 bar total pressure. It turned out that the mine water is supersaturated with respect to many sulphates of Ca, Mg, Sr, Zn, K, Cu, Ni, Cd, Be, Al, Ce and Y, fluorides of (Ln and Y, Sc), and Y phosphate.
Chemical evidence from laboratory experiments for biokarst development in the Ordos Basin, northwestern China
Authors: Zhang Feng’e , Zhang Sheng , Yin Miying , He Ze , Geng Xinxin
Published: June 2019

The present work is designed to simulate the dissolution of sulphate rock under various conditions of different bacterial cell numbers, temperatures and reaction times both in water-rock system and water-rock-bacteria systems by laboratory experiment. The rate of sulphate reduction were estimated using the experimental data. The results suggested that the sulphate-reducing bacteria promote the sulphate rock dissolution and increase the amount of dissolved sulphate. The dissolution of sulphate rock driven by bacterial sulphate reduction results in the formation of sulphate rock karst. The research is an insight into biokarst, which provides a new perspective for the field of petroleum geology.
The hydrochemical characteristics and quality assessment of groundwater in Shuangliao City, China
Authors: Liu Mingjun , Xiao Changlai , Liang Xiujuan
Published: June 2019

In this study, a hydrochemical investigation was conducted in Shuangliao city to identify the hydrochemical characteristics and the quality of groundwater using descriptive statistics and correlation matrices. And on that basis, combined with Analytic hierarchy process (AHP), an improved two-level fuzzy comprehensive evaluation method is used to evaluate the groundwater quality. The results indicate that the major cations and anions in groundwater are Ca2+ and HCO3-, respectively. The chemical types are mainly HCO3—Ca type water, some areas are complicated due to the influence of human activities. The evaluation results show that the water quality in the area is mostly III type water, and the groundwater quality in some areas is IV or V water due to the influence of primary geological conditions or human activities. The groundwater quality in the East Liaohe River Valley and Shuangliao urban area is relatively poor, and in the northwest part which is the saline alkali soil area is also relatively poor.
Water–rock interaction within the oligotrophic peat bog (part of the Vasyugan Swamp, Western Siberia)
Authors: Savichev Oleg , Mazurov Aleksey , Rudmin Maxim , Soldatova Evgeniya
Published: June 2019

Geochemical conditions of the formation of various minerals were studied within the oligotrophic pine-shrub and sphagnum peat bog. It was shown that at least two complex barriers function within the peat deposit. These barriers correspond to the changes in the advective and diffusion transfer of substances and promote the immobilization of Fe and a number of other chemical elements. The upper complex geochemical (redox, sulfide and sorption) barrier occurs approximately at the depths of 0.40 to 1.25 m. The lower complex geochemical (alkaline and sorption) and mechanical barriers are located at the bottom part of the peat deposit (the depth of 2.25–2.50 m).
The chemical and isotopic compositions of thermal waters and gases in the Republic of Buryatia, Russia
Authors: Zippa Elena , Plyusnin Alexey , Shvartsev Stepan
Published: June 2019

The chemical and isotopic compositions of waters and associated gases in the Republic of Buryatia are investigated in this report. Results show the thermal waters are predominantly enriched in N2. They are alkaline, low salinity and have high concentrations of HCO3-, SO42-, F, Si but low values for Ca2+, Mg2+, K+. According to isotopic composition, the thermal waters are meteoric in origin. Despite the low salinity, the thermal waters are in equilibrium with calcite, magnesite, fluorite, albite, laumontite and other minerals but are not equilibrium with respect to primary aluminosilicates. This indicates that the thermal waters and water-bearing rocks represent the equilibrium-nonequilibrium system.
Geochemical conditions of hydrocarbon accumulation in low-permeability shale sequences
Authors: Kerimov Vagif , Mustaev Rustam , Serikova Uliana , Ismailov Javidan
Published: June 2019

The report is devoted to the study of conditions for the formation of organic porosity–void spaces of organic origin formed during transformation of the organic matter into hydrocarbons, and their role in the formation of hydrocarbon accumulation in low-permeability shale strata. The experience of studying and developing known shale formations of the world testifies to the fact that such strata are hybrid phenomena, that is, they are both oiland gas-bearing strata containing traditional and non-traditional accumulations of hydrocarbons. Based on the results of the programmed pyrolysis by the Rock-Eval-6 method, an estimate has been performed to quantify organic (kerogen) porosity. This estimate allows for determining the forecast retention volume of HCs generated during catagenesis.
Natural hydrogen the fuel of the 21st century
Authors: Truche Laurent , Bazarkina Elena F.
Published: June 2019

Much has been learned about natural hydrogen (H2) seepages and accumulation, but present knowledge of hydrogen behavior in the crust is so limited that it is not yet possible to consider exploitation of this resources. Hydrogen targeting requires a shift in the long-standing paradigms that drive oil and gas exploration. This paper describes the foundation of an integrated source-to-sink view of the hydrogen cycle, and propose preliminary practical guidelines for hydrogen exploration.
The HydroGeo Software Package and Its Usage
Authors: Dutova Ekaterina , Nikitenkov Aleksey , Kuzevanov Konstantin
Published: June 2019

This article presents experience of development and application of the HydroGeo software package used to handle practical and scientific tasks in the field of hydrogeochemistry and hydrogeology. There are examples of its application and basic scientific and practical results.
Arsenic mobilization in the piedmont area of the Hetao basin: an insight from a reactive transport model
Authors: Gao Zhipeng , Guo Huaming , Zhang Di , Zhao Bo
Published: June 2019

Groundwater showed a trend from oxic-suboxic conditions in the alluvial fan to anoxic conditions in the flat plain in the Hetao basin, with increases in As, Fe2+, NH4+, alkalinity and pH, and decreases in Eh and NO3-. A 1D reactive transport model was constructed using a model flow column by PHREEQC to quantitatively interpret geochemical processes related to As mobilization in a 5000 m-long hydrogeological unit. Results indicated that groundwater As concentration was mostly controlled by Fe(III) oxide reduction and As adsorption processes. Observed Fe2+ was the combination of Fe(III) oxide reduction and mackinawite/siderite precipitation. Increasing alkalinity was the result of oxidation of organic carbon, rather than the dissolution of carbonates.
Adsorption of Cu(II) from aqueous solution using raw peat: preliminary results
Authors: Naymushina Olga , Gaskova Olga
Published: June 2019

Peat is a polar, highly porous material that could have significant applications as an adsorbent for removal of heavy metals from aqueous solutions. Various functional groups in lignin allow such compounds to bind on active sites of peat. The adsorption of Cu (II) from aqueous solutions on peat from the West Siberia was studied in the concentration range of 10–150 mg/L and time variations of 0.25-12 hours. The pH of the solutions varied over a range of 3.2–4.3. The adsorption data could be fitted to a Freundlich adsorption isotherm and the maximum adsorption capacity of peat was determined to be 2.5⋅10-3 mmol/g when the initial concentration for Cu2+ was at its minimum (0.05 mmol/L), and the time of adsorption was 30 minutes.
Hydrogeochemistry of Groundwater from Kazaure Area, NW Nigeria using Multivariate Statistics
Authors: Ado Musa , Adeyeye Oluwafemi , Xiao Changlai , Liang Xuijuan
Published: June 2019

This study was aimed at understanding the factors affecting groundwater for the benefit of water resources management. Groundwater collected from 18 sites over an area of 770 Km2 was analysed. Temperature (Temp.), pH, Total Dissolved Solids (TDS) and Electrical Conductivity (EC) were measured in the field and 15 chemical parameters analysed in the laboratory. Factor Analysis (FA) of physiochemical results indicated mineralization, weathering of silicates and K-feldspar, and anthropogenic sources were mainly responsible for groundwater chemistry. Hierarchical Cluster Analysis (HCA) revealed sample clusters were mainly controlled by structure rather than by lithology, water source or altitude because 86% of cluster I samples occurred along a NNE-SSW trending fault zone. It was thus concluded that water-rock interaction, tectonics and anthropogenic factors are responsible for water physiochemistry.
Arsenic in the hot springs in the Yunnan-Sichuan-Tibet Geothermal Province, China
Authors: Guo Qinghai
Published: June 2019

The Yunnan-Sichuan-Tibet Geothermal Province (YST) in China is characterized by extremely high terrestrial heat flow and widely distributed hydrothermal systems, which are discharging geothermal waters with a wide range of arsenic concentrations. In this paper, the distribution of arsenic in the YST geothermal waters are presented, the general hydrochemistry of these waters is described, and the primary geochemical processes controlling the concentrations and speciation of geothermal arsenic in YST is considered.
Analysis of the Hydrochemical Characteristics and the Evolutionary Stages of Brine in Mahai Salt Lake in the Qaidam Basin
Authors: Hu Shu-ya , Zhao Quan-sheng , Zhang Jian-wei , Chen Jian-lei
Published: June 2019

The objective of this study was to contribute to the understanding of the hydrochemical processes and evolution of brine in the Qaidam basin, in order to provide a theoretical basis for the application of brine resources in the region. The hydrochemical characteristics and evolutionary stages of brine in Mahai Salt Lake were investigated using factor analysis on brine chemistry data from 109 sampling points. Our results showed that the centre of the Salt Lake has the highest concentration of total dissolved solids (TDS), and the hydrochemical type of brine is chloride-magnesium. The brine at the centre of the lake is at the later stages of mirabilite precipitation, and the content of K+ is relatively stable. Comparatively, the hydrochemical type of brine in the slope area of the Salt Lake is Cl-Na-Mg, and is at the early stages of brine evolution. It is of guiding significance to further develop and utilize brine resources, especially to evaluate its resource development potential.
Lake water and talik groundwater interaction in continuous permafrost, Central Yakutia
Authors: Pavlova Nadezhda , Lebedeva Liudmila , Efremov Vladimir
Published: June 2019

Structural features of a lake talik associated with eolian relief are discussed. Analysis of hydrochemical and hydrological data for 2010-2017 showed that talik groundwater feeds lake and maintains perennial outflow from the lake. Variations in the chemical composition of the lake and outflowing creek are characterized on an annual and interannual basis. Seasonal comparison of hydrochemical data indicates a downward trend in dissolved-solids content of the lake water over the last six years, suggesting an increasing contribution of suprapermafrost groundwater to the lake and lake talik. Probable reason of enhanced suprapermafrost flow is increase of its duration due to observed rise of winter air temperature.
Combining multiple isotope and noble gas data with seismic profiles in an interpretation of hydro-geochemical anomalies
Authors: Szocs Teodora , Kóbor Bujdosó Éva
Published: June 2019

Environmental isotopes (δ18O, δD, δ13C, 14C, 87Sr/86Sr), combined with hydrogeochemical data and seismic profile interpretation, have been used in studying regional groundwater flow systems in the Pannonian Basin. An interpretation of seismic profiles indicates the existence of faults systems, some of them being traceable from the Pre-Cenozoic basement up to near-surface Quaternary sediments. The Lakitelek study area shows high He contents (22 to 25 %) of mantle origin, where fault lines might have been reactivated during recent geological times and facilitated the occurrence of mantle-derived He in the groundwater. The Mezőtúr study area, where most H- and O-isotope compositions are shifted from the global meteoric water line, exhibits 7.6 to 10.6 % He of mantle origin,. The deepest sample indicates mixing with formation waters. Here basement faults might not have been reactivated, since they do not seem to have an active role on the groundwater composition and effects of the regional flow system seem to be the dominant factor determining the groundwater isotope compositions.
Geochemistry of ground water the Yurubcheno-Tokhomo hydrocarbon accumulation zone
Authors: Trifonov Nikolay
Published: June 2019

In this study the chemical analysis of groundwater in Yurubcheno-Tokhomo hydrocarbon accumulation zone (YTHAZ) was carried out. The analysis revealed that fresh, brackish, saline waters and brines of various chemical types occur in the study area. Water salinity increases with the depth, but this dependency is not observed in Vendian and Riphean oil and gas deposits. The most mineralized brines occur in the salt-bearing hydrogeological formation. On the basis of the data on the geochemistry of groundwater, the possibilities of their further practical application were determined.
Hydrothermal remobilization platinum group elements and their secondary minerals in chromitite deposits of the Eastern Sayan ophiolites (Russia)
Authors: Kiseleva Ol’ga , Airiyants Evgeniya , Belyanin Dmytriy , Zhmodik Sergey
Published: June 2019

Serpentinization is an important post-magmatic process in spreading and subducted zones. This process is the cause of the remobilization and redistribution of highly mobile elements, platinum group elements (PGE) and base metals. Secondary platinum group minerals (PGMs) formed because of PGE remobilization under the action of mantle and crustal fluid on the rocks. The formation of the secondary PGMs can occur in several stages. Under the effect on the chromitites of reduced mantle fluids, native PGE alloys were formed during early serpentinization. Under dehydrating subducted slab fluid phase was caused in serpentinization mantle peridotites and have been dissolved magmatic high-temperature platinum group minerals. During the obduction of ophiolites, an inversion from reducing to oxidizing condition took place with the formation of nickel arsenides and As, Sb – bearing PGMs.
The Khaung Daing hot spring (Inle lake, Southern Shan State, Myanmar): development opportunities and challenges
Authors: Sacchi Elisa , Comizzoli Sergio , Di Sipio Eloisa , Re Viviana , Rotiroti Marco , Setti Massimo , Thin Myat Mon
Published: June 2019

Located on the north-western border of the Inle lake basin, the Khaung Daing hot spring outflows at ca. 70°C. Temperature at depth, calculated with chemical geothermometers is probably less than 150°C, therefore classifying it as a medium-low enthalpy geothermal resource. Geochemical and isotopic results also demonstrate that the hot spring is fed by local groundwater, equilibrated with the carbonate rocks but without isotopic exchange with the matrix. Trace elements, particularly As (119 µg/L), display high concentrations, raising some concern about potential environmental and health effects.
Implications of depositional environment on the iodine enrichment in the sedimentary system: evidences from the N-alkane in sediments
Authors: Xue Xiaobin , Li Junxia , Wang Yanxin
Published: June 2019

To understand the implications of depositional environment on the enrichment of iodine in sediments, the N-alkane analysis has been conducted on the sediment from the North China Plain (NCP). The iodine contents of sediments ranged from 0.03 to 2.54 μg/g with the highest content occurring in the depth of 170-185 m. The results of sediment N-alkane (TAR, ΣT/ΣM and ACL) indicate that the marine source input is the predominant factor controlling the enrichment of iodine in the groundwater system. The Pr/Ph ratios (from 0.13 to 1.68) and the plot of Pr/n-C17 vs. Ph/n-C18 suggest that sediments deposited under suboxic to anoxic conditions. Under the oxdizing conditions, the iodine tends to be rich in the sediment, while the iodine may prefers to be released into groundwater under the reducing conditions.
Sorption of radionuclides onto minerals: Experiments and modelling
Authors: Romanchuk Anna , Semenkova Anna , Larina Alena , Kalmykov Stepan
Published: June 2019

Sorption of various radionuclides such as Cs(I), Eu(III)/Am(III), Np(V), U(VI) and others onto iron oxide (goethite, hematite) and clay minerals (montmorillonite, kaolinite) was studied at wide experimental range (pH ionic strength, total radionuclides concentrations). In all case athermodynamic model for describing sorption onto studied minerals was built and successfully applied for all experiments. The required constants were calculated or verified from published data. For modelling sorption in mineral assemblages Component Additivity (CA) approach was successfully applied.
Strontium isotopic ratio in brines from the north-east of the Angara-Lenskiy artesian basin
Authors: Alexeev Sergey , Alexeeva Ludmila , Shouakar-Stash Orfan
Published: June 2019

The Sr isotopic composition was measured in a number of samples of highly concentrated oil-field brines from the Angara-Lenskiy artesian basin. The brines are contained in the salt-bearing and subsalt-bearing hydrogeological formations at a depth of 1,500-3,000 m. They have high salinity (385-530 g/L) and high Sr content (2.3-7.0 mg/L). The 87Sr/86Sr ratio ranges from 0.70800 to 0.713062. Most brine samples exhibit an isotopic composition similar to Vendian-Cambrian paleoocean water, however several samples from the Yaraktinskiy horizon are significantly more radiogenic than others. It suggests that a considerable amount of 87Sr is likely to have been carried from terrigenous sediments due to a water-rock interaction.
Measuring reaction rates at equilibrium with the isotope doping method
Authors: Zhu Chen , Zhang Yilun , Rimstidt J Donald , Yuan Honglin
Published: June 2019

Since the time of J. H. van’t Hoff [1], it has been known that chemical equilibrium is dynamic, meaning that at equilibrium, chemical reactions do not cease, but instead the forward and backward reaction rates are equal. The constant concentrations at equilibrium preclude the use of concentrations to measure reaction rates at equilibrium. Therefore, with the exception of a few special cases, no reaction rates at equilibrium have been published in the literature of chemistry, physics, or chemical engineering. Here we report dissolution and precipitation rates at equilibrium for quartz and barite with the isotope-doping method. Experimental data show that dissolution and precipitation rates are equal at equilibrium, indicating the principle of detailed balance (PDB) appear to be applicable at these experimental conditions. The PDB has been a cornerstone for irreversible thermodynamics and chemical kinetics for a long time, and its wide application in geochemistry has mostly been implicit and without experimental testing of its applicability. Nevertheless, many extrapolations based on PDB without experimental validation have far reaching impacts on society’s mega environmental enterprises. The isotope doping method appears to able to test its applicability for a variety of minerals at a wide range of conditions.
Viscoelastic multi-resonator mechanism for broadening low-frequency band-gap of acoustic metamaterials
Authors: Liu Hongxing , Wu Jiu Hui
Published: June 2019

In this paper, viscoelastic multi-resonator mechanism for broadening low-frequency band-gaps of acoustic metamaterials is investigated. Firstly, the metamaterial unit consists of dual-mass and dual-viscoelasticity is proposed which can generate multiple resonances to form multiple band-gaps, and further the broadened band-gaps are realized by modulating the effect of the viscoelasticity. Secondly, for the dual-viscoelasticity, the band-gaps and transmission spectrum under the cases of with the consistent and inconsistent viscoelasticity are calculated. Comparing with the consistent case, by adjusting the viscoelasticity in the inconsistent case, the storage modulus changes the fastest and obtains a smaller and a larger elastic modulus at the corresponding starting frequency and ending frequency of the band-gap, in which the band-gap can be broadened and shifted to the low frequency since the resonant frequency is determined by the elastic modulus, and for the loss modulus, it has little effects on the width of the band-gap, but has great influence on the transmission coefficient. Thirdly, by adjusting the inconsistent viscoelastic parameters based on the above rules, the band width is increased by 1.7 times (1.3 times for the absolute band width) than the consistent structure and the band-gap is shifted to the low frequency by 31% (about 345 Hz). The viscoelastic multi-resonator mechanism can be used to practical applications of viscoelastic metamaterials.
Stellenwert der ST-Arthroplastik in der Therapie der STT-Arthrose bei gleichzeitiger Rhizarthrose
Authors: Halim Maximilian Hermann Lorenz , Horch Raymund E. , Bach Alexander D.
Published: June 2019

Hintergrund Die Rhizarthrose gehört zu den häufigsten Arthroseformen. Nicht selten besteht gleichzeitig auch eine STT-Arthrose. Als operativer
Goldstandard gelten die verschiedenen Modifikationen der Resektionsarthroplastik. In einer retrospektiven Studie wurden die postoperativen Ergebnisse der
Resektions-Suspensions-Arthroplastik (RSA) nach Lundborg, modifiziert nach Wulle mit und ohne zusätzliche ST-Arthroplastik miteinander verglichen.

Patienten und Methoden Im Rahmen der Studie wurden 50 Patienten mit symptomatischer Daumensattelgelenksarthrose (Stadium III und IV) nachuntersucht. Davon
sind 21 Patienten mittels konventioneller modifizierter Resektions-Suspensions-Arthroplastik nach Lundborg (RSA) und 29 Patienten mit derselben Technik und
zusätzlicher ST-Arthroplastik (RSA-plus) operiert worden. Es wurden der TDX-Score (Thumb Disability Examination-Score), der Kapandji-Score, das Schmerzniveau
und die Kraft im Grobgriff, im Schlüsselgriff, im palmaren Spitzgriff und im Dreifingerspitzgriff erhoben.

Ergebnisse In beiden Gruppen war die Schnitt-Naht-Zeit vergleichbar. Der Gesamt-TDX-Score betrug für die RSA-plus-Gruppe 15,9 ± 19,5 und für die
RSA-Gruppe 20,8 ± 24,3 (p > 0,05). Einen marginal signifikanten Unterschied zeigte der Kapandji-Score in der RSA-plus-Gruppe mit 9,5 ± 1,1 und in der
RSA-Gruppe mit 8,9 ± 1,6 (p = 0,08). Die Kraft im Grobgriff (RSA-plus: 48,3 ± 21 kPa, RSA: 55,2 ± 24,9 kPa (p > 0,05)), im Schlüsselgriff (RSA-plus:
32,6 ± 15 kPa, RSA: 37,3 ± 15,4 kPa (p > 0,05)), im palmaren Spitzgriff (RSA-plus: 30,6 ± 12,9 kPa, RSA: 34,8 ± 12,4 kPa (p > 0,05)) sowie im
Dreifingerspitzgriff (RSA-plus: 36,2 ± 14,2 kPa, RSA: 42 ± 13,6 kPa (p > 0,05)) wiesen in beiden Gruppen keine signifikanten Unterschiede auf. Die
Schmerzintensität in Ruhe (RSA-plus: 0,4 ± 1,3, RSA: 1 ± 2,1 (p > 0,05)), bei Bewegung (RSA-plus: 0,7 ± 1,8, RSA: 1,6 ± 2,7 (p > 0,05)) und bei Belastung
(RSA-plus: 1,6 ± 2,5, RSA: 2,9 ± 3,4 (p > 0,05)) zeigten sich in beiden Gruppen insignifikant unterschiedlich.

Zusammenfassung In den nachuntersuchten Patientengruppen zeigten sich keine signifikanten Unterschiede in den untersuchten Variablen. Wir stellen somit
fest, dass keine Nachteile bestehen eine zusätzliche ST-Arthroplastik zur konventionellen Resektions-Suspensions-Arthroplastik durchzuführen. Wir sind aufgrund
der erhobenen Daten der Ansicht, dass die Indikation zur ST-Arthroplastik im Rahmen der RSA großzügig gestellt werden sollte.
Effects of Gut Microbiota and Ingredient-Ingredient Interaction on the Pharmacokinetic Properties of Rotundic Acid and Pedunculoside
Authors: Yang Bao , Li Hui , Ruan Qingfeng , Xuan Shenxin , Chen Xiaojing , Cui Hui , Liu Zhongqiu , Jin Jing , Zhao Zhongxiang
Published: June 2019

Rotundic acid and pedunculoside are the most abundant constituents in Ilicis Rotundae Cortex, and possess lipid-lowering activity. In this study, we evaluated the pharmacokinetic interactions of rotundic acid with pedunculoside and other ingredients from Ilicis Rotundae Cortex with rotundic acid and pedunculoside, and preliminarily investigated the effects of gut microbiota on their pharmacokinetics using a pseudo-germ-free rat model. After a single oral administration of each monomer, a monomer mixture, and Ilicis Rotundae Cortex extract to the conventional and pseudo-germ-free rats, rotundic acid and pedunculoside were quantified in plasma by an UPLC/Q-TOF-MS/MS method. The systemic exposure (maximum plasma concentration and area under concentration-time curve) of two analytes in conventional rats were increased in an approximately dose-dependent manner. Oral administration of rotundic acid and pedunculoside in the forms of a monomer mixture and Ilicis Rotundae Cortex extract to the conventional rats significantly decreased the systemic exposure compared with the monomer groups, which demonstrated the existence of significant pharmacokinetic interactions. The pseudo-germ-free rats were prepared by nonabsorbable antibiotic treatment, and the systemic exposure of two analytes were significantly decreased and most of the “time to reach the maximum” values were delayed in comparison to conventional rats, therefore gut microbiota might serve as an efficient absorption promoter. These results provide a scientific basis for the clinical application of the two bioactive constituents and Ilicis Rotundae Cortex.
Risk of post-colonoscopy colorectal cancer in Denmark: time trends and comparison with Sweden and the English National Health Service
Authors: Pedersen Lasse , Valori Roland , Bernstein Inge , Lindorff-Larsen Karen , Green Charlotte , Torp-Pedersen Christian
Published: June 2019

Background The post-colonoscopy colorectal cancer (PCCRC) rate is a key quality indicator for colonoscopy. Previously published PCCRC rates have been difficult to compare owing to differences in methodology. The primary aim of this study was to compare Danish PCCRC rates internationally and to calculate Danish PCCRC rates using the World Endoscopy Organization (WEO) consensus method for future comparison. The secondary aim was to identify factors associated with PCCRC.

Methods National registries were used to examine the risk of PCCRC. The Danish 3-year rate of PCCRC (PCCRC-3yr) was calculated using previously published methods from England, Sweden, and the WEO. Poisson regression analysis was performed to identify factors associated with PCCRC.

Results The Danish PCCRC-3yr was significantly higher than the rate in the English NHS (relative risk [RR] 1.12, 95 % confidence interval [CI] 1.05 – 1.19) and Sweden (RR 1.15, 95 %CI 1.06 – 1.24). The Danish PCCRC-3yr based on the WEO consensus method fell from 22.5 % in 2001 to 7.9 % in 2012. The multivariable Poisson regression model found PCCRC to be significantly associated with diverticulitis (RR 3.25, 95 %CI 2.88 – 3.66), ulcerative colitis (RR 3.44, 95 %CI 2.79 – 4.23), hereditary cancer (age < 60 years: RR 7.39, 95 %CI 5.77 – 9.47; age ≥ 60 years: RR 3.81, 95 %CI 2.74 – 5.31), and location in the transverse (RR 1.57, 95 %CI 1.28 – 1.94) and ascending colon (RR 1.85, 95 %CI 1.64 – 2.08).

Conclusions The PCCRC-3yr was higher in Denmark than in comparable countries. Differences in colonoscopist training, background, and certification are possible contributing factors. A review of colonoscopist training and certification in Denmark, and continuous audit and feedback of colonoscopist performance may reduce PCCRC-3yr.
Endocuff-assisted colonoscopy for surveillance of serrated polyposis syndrome: a multicenter randomized controlled trial
Authors: Rivero-Sánchez Liseth , López Vicente Jorge , Hernandez Villalba Luis , Puig Ignasi , Arnau-Collell Coral , Moreno Lorena , Díaz Mireia , Rodriguez de Miguel Cristina , Ocaña Teresa , Moreira Leticia , Cuatrecasas Miriam , Carballal Sabela , Sánchez Ariadna , Ortiz Oswaldo , Llach Josep , Balaguer Francesc , Pellisé María ,   on behalf of the EndoCAR group from the Spanish Gastroenterology Association and the Spanish Society of Digestive Endoscopy
Published: June 2019

Background and study aims Serrated polyposis syndrome (SPS) is a condition with high risk for colorectal cancer. The Endocuff device has been shown to increase adenoma detection in the general and screening population. We aimed to ascertain whether Endocuff-assisted colonoscopy increases detection of serrated lesions in comparison with standard colonoscopy during the surveillance of patients with SPS. 

Methods In a multicenter randomized controlled study, patients who met SPS criteria I and/or III under surveillance (previous resection of all serrated lesions ≥ 4 mm) were consecutively randomly allocated 1:1 to Endocuff-assisted colonoscopy or standard colonoscopy, performed by expert endoscopists. The main outcome was the mean number of serrated lesions detected per patient.

Results 122 patients (standard colonoscopy n = 60; Endocuff-assisted colonoscopy n = 62; 59 % men; mean age 60.6 (standard deviation [SD] 7.5) were included at 4 centers. Baseline variables (demographic data, SPS phenotype, colorectal cancer [CRC] history, cumulative polyps, and follow-up), cecal intubation rate, and withdrawal time were similar between groups. There was no statistically significant difference between Endocuff-assisted colonoscopy and standard colonoscopy for the mean number of serrated lesions detected per patient: 5.8 (95 % confidence interval [95 %CI] 4.4 – 7.2) and 5.0 (3.9 – 6.1), respectively (P = 0.36). There were also no differences between Endocuff-assisted and standard colonoscopy for detection of sessile serrated lesions (mean number per patient 2.5 [1.3 – 3.6] vs. 2.0 [1.1 – 3.0], P = 0.54) and adenomas (0.9 [0.5 – 1.3] vs. 0.5 [0.3 – 0.7], P = 0.12).

Conclusion Use of Endocuff-assisted colonoscopy did not significantly increase the number of serrated lesion detected per patient during surveillance of SPS.
PROTEIN AGGREGATES IN HEATED BLOOD PRODUCTS
Authors: Freeman L , Hornsey V , Pepper D S , Foster P R , Winkelman L , Dawes J
Published: June 2019

Heating of blood products to reduce viral infectivity is now a standard practice. Such treatment may also modify the constituent proteins, reducing their activity or altering their structure with potentially harmful consequences for the recipient. Partially denatured proteins frequently form aggregates, which are often immunogenic and could precipitate immune complex formation, allergic reactions and kidney damage. In addition they may contribute to the development of AIDS after HIV infection by inducing a persistent state of T-cell activation.

Protein aggregate formation in factor VIII and factor IX (II + X) concentrates has been investigated by fast protein liquid chromatography (FPLC), which proved to be a rapid, convenient method for this purpose. Freeze-drying alone resulted in aggregate formation in intermediate purity FVIII concentrates, but not in FIX concentrates. However, aggregates were detected after heating the FIX concentrate at 80°C for 72h in the dry state. Dry heating of intermediate purity FVIII concentrates to 68°C for 24h also increased the content of protein aggregates, which contained fibrinogen and fibronectin but little IgG. In this product, the aggregate content after heating correlated with total protein concentration. A higher purity FVIII concentrate selectively depleted in fibrinogen and fibronectin also contained protein aggregates after freeze-drying, but heating this product at 80°C for 72h resulted in a relatively small increase in aggregate content. Haemophiliacs receiving regular injections of heated concentrates are constantly exposed to protein aggregates. They should be monitored for any harmful effects, and manufacturers should aim to reduce the aggregate content of their products.
THE INTERACTION OF THE FACTOR VIII/vWF COMPLEX WITH IMMOBILISED METAL AFFINITY CHROMATOGRAPHY (IMAC) MATRICES
Authors: Saundry R H , Kopp P , Savidge G F
Published: June 2019

1MAC principles were used to investigate the binding of Factor VIII/vWF from either Al(OH)3 - absorbed citrated PPP or cryoprecipitate using citrate-saline buffers. Factor VIII/ vWF showed high affinity for both Zn2+ - or Cu2+ - immobilised on biscarboxymethylaminoSepharose 4B at ambient room temperature, but no interaction with Ca2+, Mg2+, Mn2+ or Cd2+ - immobilised matrices.

Factor VIII/vWF could be re-eluted as a single component from Zn2+ - columns using either decreasing pK, or increasing competitor ligandconcentrations. In pK gradients comprising 14mM citrate, 2.14mM CaCl2, 0.15m NaCl Factor VIII eluted at pH 6.50, whereas in pH gradients comprising 0.1m Tris, 2.5mM CaCl2 pH 7.5 and 0.1M succinate, 2.5mM CaCl2 pH 5.5 Factor VIII eluted at pH 6.06. Citrate behaves as a competitor ligand; at 4° in citrate buffer Factor VIII did not bind.

In citrate-saline buffers pH 7.2 Factor VIII could be reeluted in high yield (100% Factor VIII:Ag; 70% VIII:C; 90% vWF:Ag) through application of linear competitor ligand gradients (at 11.5mM imidazole, 15.4mM dl-Eistidine, 45mM L-Lysine, or 1.7% BSA) , whereas 1.0M NaCl or 1.0M NH4Cl were ineffective. The Factor VIII activities co-eluted ahead of, but incompletely resolved from the re-eluted Fg and Fn.
If 5 mg/ml. BSA was incorporated into the buffers Factor VIII was quantitatively recovered in the column wash - through fractions leaving all the Fg and Fn bound to the matrix.