bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the thermal decomposition characteristics of C4F7N–CO2 mixture as eco‐friendly gas‐insulating medium
Authors: Li Yi , Zhang Xiaoxing , Zhang Ji , Xie Cheng , Shao Xianjun , Wang Ziling , Chen Dachang , Xiao Song
Published: June 2019

The authors explored the thermal decomposition characteristics of perfluoroisobutyronitrile–carbon dioxide (C4F7N–CO2) gas mixture as eco‐friendly dielectric medium. The main by‐products and decomposition mechanism of C4F7N–CO2 gas mixture under different temperature and gas pressure conditions were revealed and analysed. It was found that the thermal decomposition of 6%C4F7N–94%CO2 gas mixture starts at about 350°C (0.15 MPa), producing C3F6 and CO first. Some other characteristic by‐products such as CF4, C2F6, CF3CN, COF2 and (CN)2 could also be detected at higher temperature. The yield of C3F6, (CN)2 increased with the temperature (lower than 450°C) first and then decreased when it reached to 500°C. While the yield of CO, C3F8, COF2 and CF3CN increased with temperature (350–550°C). The generation of CF4 and C2F6 begins at temperatures higher than 500°C, which can be used as the feature component of severe overheating fault. The thermal decomposition amount and by‐products yield of C4F7N–CO2 gas mixture slowed down with the increase of gas pressure, indicating that C4F7N–CO2 gas mixture is quite suitable used at high‐pressure equipment, especially high‐voltage devices such as gas insulated switchgear.
Indications for transit-timing variations in the exo-Neptune HAT-P-26b
Authors: von Essen C. , Wedemeyer S. , Sosa M. S. , Hjorth M. , Parkash V. , Freudenthal J. , Mallonn M. , Miculán R. G. , Zibecchi L. , Cellone S. , Torres A. F.
Published: June 2019

Upon its discovery, the low-density transiting Neptune HAT-P-26b showed a 2.1σ detection drift in its spectroscopic data, while photometric data showed a weak curvature in the timing residuals, the confirmation of which required further follow-up observations. To investigate this suspected variability, we observed 11 primary transits of HAT-P-26b between March, 2015, and July, 2018. For this, we used the 2.15 m Jorge Sahade Telescope placed in San Juan, Argentina, and the 1.2 m STELLA and the 2.5 m Nordic Optical Telescope, both located in the Canary Islands, Spain. To add to valuable information on the transmission spectrum of HAT-P-26b, we focused our observations in the R-band only. To contrast the observed timing variability with possible stellar activity, we carried out a photometric follow-up of the host star over three years. We carried out a global fit to the data and determined the individual mid-transit times focusing specifically on the light curves that showed complete transit coverage. Using bibliographic data corresponding to both ground and space-based facilities, plus our new characterized mid-transit times derived from parts-per-thousand precise photometry, we observed indications of transit timing variations in the system, with an amplitude of ~4 min and a periodicity of ~270 epochs. The photometric and spectroscopic follow-up observations of this system will be continued in order to rule out any aliasing effects caused by poor sampling and the long-term periodicity.
CO observations of major merger pairs at z =  0: molecular gas mass and star formation
Authors: Lisenfeld Ute , Xu Cong Kevin , Gao Yu , Domingue Donovan L. , Cao Chen , Yun Min S. , Zuo Pei
Published: June 2019

We present CO observations of 78 spiral galaxies in local merger pairs. These galaxies represent a subsample of a Ks-band-selected sample consisting of 88 close major-merger pairs (HKPAIRs), 44 spiral–spiral (S+S) pairs, and 44 spiral–elliptical (S+E) pairs, with separation <20 h−1 kpc and mass ratio <2.5. For all objects, the star formation rate (SFR) and dust mass were derived from Herschel PACS and SPIRE data, and the atomic gas mass, MHI, from the Green Bank Telescope HI observations. The complete data set allows us to study the relation between gas (atomic and molecular) mass, dust mass, and SFR in merger galaxies. We derive the molecular gas fraction (MH2/M*), molecular-to-atomic gas mass ratio (MH2/MHI), gas-to-dust mass ratio and SFE (= SFR/MH2) and study their dependences on pair type (S+S compared to S+E), stellar mass, and the presence of morphological interaction signs. We find an overall moderate enhancement (∼2×) in both molecular gas fraction (MH2/M*) and molecular-to-atomic gas ratio (MH2/MHI) for star-forming galaxies in major-merger pairs compared to non-interacting comparison samples, whereas no enhancement was found for the SFE nor for the total gas mass fraction ((MHI + MH2)/M*). When divided into S+S and S+E, low mass and high mass, and with and without interaction signs, there is a small difference in SFE, a moderate difference in MH2/M*, and a strong difference in MH2/MHI between subsamples. For the molecular-to-atomic gas ratio MH2/MHI, the difference between S+S and S+E subsamples is 0.55 ± 0.18 dex and between pairs with and without interaction sign 0.65 ± 0.16 dex. Together, our results suggest that (1) star formation enhancement in close major-merger pairs occurs mainly in S+S pairs after the first close encounter (indicated by interaction signs) because the HI gas is compressed into star-forming molecular gas by the tidal torque; and (2) this effect is much weakened in the S+E pairs.
Reconstructing solar magnetic fields from historical observations
Authors: Virtanen I. O. I. , Virtanen I. I. , Pevtsov A. A. , Bertello L. , Yeates A. , Mursula K.
Published: June 2019

Aims. The evolution of the photospheric magnetic field has only been regularly observed since the 1970s. The absence of earlier observations severely limits our ability to understand the long-term evolution of solar magnetic fields, especially the polar fields that are important drivers of space weather. Here, we test the possibility to reconstruct the large-scale solar magnetic fields from Ca II K line observations and sunspot magnetic field observations, and to create synoptic maps of the photospheric magnetic field for times before modern-time magnetographic observations.

Methods. We reconstructed active regions from Ca II K line synoptic maps and assigned them magnetic polarities using sunspot magnetic field observations. We used the reconstructed active regions as input in a surface flux transport simulation to produce synoptic maps of the photospheric magnetic field. We compared the simulated field with the observed field in 1975−1985 in order to test and validate our method.

Results. The reconstruction very accurately reproduces the long-term evolution of the large-scale field, including the poleward flux surges and the strength of polar fields. The reconstruction has slightly less emerging flux because a few weak active regions are missing, but it includes the large active regions that are the most important for the large-scale evolution of the field. Although our reconstruction method is very robust, individual reconstructed active regions may be slightly inaccurate in terms of area, total flux, or polarity, which leads to some uncertainty in the simulation. However, due to the randomness of these inaccuracies and the lack of long-term memory in the simulation, these problems do not significantly affect the long-term evolution of the large-scale field.
The unique Abramovka REE-rich mineralization is a potential source of REE for the Pavlovsk coals deposit (Primorsky Krai, Russia)
Authors: Chekryzhov Igor , Tarasenko Irina , Vakh Elena , Vysotsky Sergey
Published: June 2019

The unique REE mineralization of the Abramovka ore occurrence, associated near-surface waters, and REE-rich coals of the Pavlovka basin were studied. The authors, on the base of new isotope-geochemical data and K-Ar dating, suggest that the Abramovka REE minerals (hydrocarbonates, hydrophosphates and hydroxides) formed as a result of interaction of the Palaeozoic metasedimentary and Mesozoic volcanic rocks with near-surface waters. In the Pavlovka metalliferous coals, REE are concentrated predominantly in a humic matter that sorbed REE from water solutions during the peat accumulation stage. A similar distribution of REE in the Abramovka ores, associated near-surface waters, and metalliferous coals of the Pavlovka basin suggest that the Abramovka-type mineralization might be a major source of REE enrichment in the Pavlovka coals.
Historical mine pollution and environmental resilience: biomineralization processes and biogeochemical barriers
Authors: De Giudici Giovanni , Medas Daniela , Cidu Rosa , Lattanzi Pierfranco , Podda Francesca , Rigonat Nicola , Marras Pier Andrea , Wanty Richard B. , Kimball Briant , Runkel Robert L.
Published: June 2019

Three streams in SW Sardinia were studied to evaluate the transport of metals in the environment, and to characterize the natural processes that lead to decreased metal loads. Here we focus on Zn. Although the metal load varies by 2-3 orders of magnitude, we have observed natural biologically mediated attenuation processes, including uptake by vegetation and biomineralization. In this paper, we review the chemical and physical processes that lead to natural Zn attenuation, and discuss the merits of mimicking those processes when designing remediation schemes.
Hydrogeochemistry of high-fluoride saline groundwater in the Yuncheng Basin, northern China
Authors: Li Chengcheng , Gao Xubo , Wang Yanxin , Howard Ken
Published: June 2019

The presence of saline groundwater has become one of the most acute problems for water resource management worldwide, since it causes deterioration in water quality and endangers future exploitation of groundwater resources. In addition, high levels of groundwater salinity are often associated with an increase in the concentrations of fluoride (F). Diverse mechanisms govern salts and fluoride enrichment in groundwater. In this case, saline groundwater with elevated fluoride (up to 14.1 mg/L) in the Yuncheng Basin (YB) was investigated. The research shows: (i) large-scale contamination of F in groundwater is closely associated with groundwater salinization processes in the area; (ii) groundwater with high F concentrations has distinctive major ion chemistry: Na-rich and Ca-poor with a high pH and HCO3- content. The major ion chemistry and pH are controlled by mineral dissolution, cation exchange, and evaporation in the aquifer systems which are also important for F mobilization.
Distribution of the stable isotopes (δ18O, δD и δ13C) in natural waters of the Baydar valley (Crimean Peninsula)
Authors: Novikov Dmitry A. , Nichkova Larisa A. , Chernykh Anatoliy V. , Dultsev Fedor F. , Pyryaev Alexander N. , Sigora Galina A. , Khomenko Tamara Yu.
Published: June 2019

Results of the study of the stable isotopes (δ18O, δD and δ13C) distribution in natural waters of the Baydar valley (southwestern part of the Crimean Peninsula) are presented. The study region holds fresh and ultra-fresh waters of predominantly bicarbonate calcium composition with TDS varying from 194 to 1137 mg/dm3. The research results revealed that all of the studied waters are of atmospheric origin that lie either along the global (GMWL) or local (LMWL) meteoric water lines. The established variations are: from -9.5 to -5.6‰ for δ18O values in waters with δD values varying from -64.0 to -40.0‰. The source for bicarbonate ion enriched in δ13C in natural waters of the Bauydar valley are carbonate sedimentary rocks, atmospheric carbon dioxide and organic compounds. Surface waters have heavier isotopic composition δ13C (-9.2 – -7.0‰) because of the atmospheric CO2. Artesian waters are differentiated by lighter δ13C (-12.8 – -10.7‰) due to the interactions between carbonate rocks and the dispersed organic matter. Water sources (springs, wells) are characterized by the widest variations of δ13C (-6.9 – -15.5‰) due to the presence of the atmospheric CO2 and intense processes of biochemical decomposition of organic compounds in the soil layer.
Storage and processing of acid waste waters of mining enterprises
Authors: Plyusnin Alexei , Smirnova Olga , Robinson Paul
Published: June 2019

In the present work, the formation of the chemical composition of acid mine waters in the area of waste disposal of mining and processing of tungsten ores of Transbaikalia (Russia) is considered. It is shown that during long-term storage of processing waste in the pore space, acidic waters with a high content of rare-earth elements accumulate. During the recycling of waste in the washings, a change occurs in the ratio of light and heavy rare earth elements. When water is neutralized with limestone, solid phases of these elements are formed, which can be extracted.
Nitrogen behavior in the shallow groundwater–soil system within agricultural landscapes
Authors: Soldatova Evgeniya , Dong Yihui , Li Jiale , Sun Zhanxue
Published: June 2019

The research is devoted to the analysis of the changes in the chemical composition of shallow groundwater within the agricultural landscapes of the Poyang Lake area taking into account the peculiarities of soil composition. The analysis is based on field data collected during 2011–2017 by the sampling of the shallow groundwater from the private and public wells and adjoining soils. Correlations between the content of the N-compounds and the Eh values in autumn as well as a relationship of the NH4+ concentration with the DOC content reflect the processes of the organic matter transformation in the aquifer. Correlations between the N content in the upper soil horizon and the concentrations of the N-compounds in the shallow groundwater indicate a strong connection of the origin of the groundwater chemical composition with the soil composition.
Experimental Study of the Mechanism of Acid Rain-Gabbro Interaction
Authors: Zhao Xiaoyan , Li Kunpeng , Xiao Dian , Li Xun
Published: June 2019

As a common natural disaster, acid rain could not only cause serious environmental pollution, but also endanger the engineering properties of rock due to water-rock interactions. The failure of slopes of mafic igneous or ultramafic igneous rock is not unusual in areas affected by acid rain, but the specific mechanism of instability remains to be studied. In this study, fresh gabbro samples were processed, and a simulated acid rain treatment of pH 3.0 in the laboratory was carried out. Then the shear strength parameters were evaluated on samples before and after the acid rain test. Finally, the samples were analyzed by X-ray Diffraction (XRD), Polarizing Microscope and Scanning Electron Microscope (SEM) to analyze the mechanism of acid rain-gabbro interaction. Overall, this study provided useful insights toward the evaluation of engineering properties of mafic igneous and ultramafic igneous rocks in acid rain area.
In situ X-ray absorption spectroscopy study of zinc and cadmium transport by S-rich fluids
Authors: Bazarkina Elena F. , Proux Olivier , Lahera Eric , Del Net William , Hazemann Jean-Louis
Published: June 2019

This experimental and theoretical study is aimed at better quantifying the transport of Zn and Cd by hydrothermal fluids rich in sulfur by using in-situ X-ray absorption spectroscopy (XAS). We measured simultaneously fluorescence and transmission spectra of dissolved metal in NaHS-H2S, K2S2O3, Na2S2O3, K2S2O3-HCl aqueous solutions at 250-350°C and 600 bar. Here the first experimental results are presented. Possible sulfur speciation models for Zn and Cd are briefly discussed.
Pore scale modelling of calcite cement dissolution in a reservoir sandstone matrix
Authors: Hinz Christian , Enzmann Frieder , Kersten Michael
Published: June 2019

Long-term evolution of permeability and tortuosity due to porosity changes evoked by reactivity of aqueous solutions is of paramount importance for predicting water-rock interaction. This challenge is best tackled by introducing reactive transport modelling on the pore-scale, where the modeling domain is a high-resolution tomographic image of the porous media. We suggest to use a voxel based Navier-Stokes-Brinkman solver in a finite volume formulation coupled to the thermodynamic equilibrium code PhreeqC. High-performance parallelized computations using this coupled numerical reactive transport solver are performed directly on the voxel grid of the segmented micro-CT scans. Retreat of the calcite cement in a sandstone matrix due to dissolution reactions can be directly visualized by digital rock physics experiments.
Climate change impact assessment on water security in South Africa: A case study in a semi-arid river basin
Authors: Woyessa Yali
Published: June 2019

The main aim of this paper is to assess the impact of regional climate change scenarios on the availability of water resources in a semi-arid river basin in South Africa using a hydrological model called Soil and Water Assessment Tool (SWAT). In this paper, climate change data was derived from two downscaling approaches, namely statistical downscaling experiment (SDE) and dynamic downscaling (CORDEX). These were derived from the GCM simulations of the Coupled Model Inter-comparison Project Phase-5 (CMIP5) and across two greenhouse gas emission scenarios known as Representative Concentration Pathways (RCP) 4.5 and 8.5. The spatial resolution of the dataset for the SDE method is 25 km × 25 km and 50 km × 50 km for the CORDEX method. Six GCM models were used for SDE set of data and four for the CORDEX set of data. SWAT model was run using these data for a period of up to mid-century (2020 – 2050) for SDE and for a period of up to the end of this century (2020 – 2100) for CORDEX data. The results were then compared with long-term historical data (1975-2005). Comparison of measured data with simulated historical data showed strong correlation (R2 = 0.95 for SDE data and R2 = 0.92 for CORDEX data), which is indicative of the reliability of projected future climate.
Role of sulfuric acid in chemical weathering of carbonate rocks for evaluating of carbon sinks in the Yangtze River Basin, China
Authors: Zhang Liankai , Qin Xiaoqun , Huang Qibo , Liu Pengyu
Published: June 2019

Chemical weathering of rock by river systems is an important process in the global carbon cycle. Sulfuric acid produced from anthropogenic sources in the Yangtze River basin of China has the potential to change rock weathering processes and the carbon cycle. Monitoring and analysis of the dissolved constituents of the main channel and major tributaries of the Yangtze River indicate that the sulfuric acid has enhanced the carbonate rock weathering rate by an average of 28% and reduced the CO2 consumption rate by 12%. Analysis of dissolved sources for SO42- in the Yangtze River indicates that 36% of SO42- can be attributed to rainwater, 26% to dissolution of evaporitic rocks, and 38% to input from coal. Calculations indicate that the annual output flux of CO2 from the Yangtze River Basin to the sea is 3495×104 tons, 80% of which is attributed to the weathering of carbonate rocks. Whilst the average consumption rate of atmospheric CO2 is 20.6 t/km2 y-1.
The speciation of chemical elements in water and their possible impact on human health
Authors: Mazukhina Svetlana , Tereshchenko Pavel , Drogobuzhskaya Svetlana , Pozhilenko Vladimir
Published: June 2019

The speciation of chemical elements in groundwaters of Apatity Kirovsky district may affect their bioavailability and toxicity. A complete hydrochemical analysis showed measurable concentrations of uranium, molybdenum, silver, barium, nickel, vanadium, aluminum, and lead, which contributed to a growing database of the chemical compositions of groundwater. Physical and chemical models showed that the vital elements calcium, sodium, potassium, magnesium and sulfate ion are in chemical forms that are favorable for human health (Ca2+, Na+, K+, Mg2+, SO42-). Forms of migration of carcinogenic or toxic elements (nickel, barium, vanadium, strontium, aluminum, lead) are among the most toxic (Ni2+, Ba2+, Sr2+) and remain so at the temperatures studied +3, +25, +37°C. One of the most insidious effects of inorganic compounds of lead, barium and strontium is the ability to replace calcium in bones isomorphically, nickel in the form of free ions (Ni2+) is 2 times more toxic than its complex compounds with inorganic and organic ligands. The results of this research can be useful in the fields of geochemistry, hydrology, ecology and medicine.
Thermal water chemistry of Yellowstone National Park after 24 years of research
Authors: Nordstrom D. Kirk , McCleskey R. Blaine , Ball James W.
Published: June 2019

The collection, analysis, and interpretation of 24 years of thermal water chemistry data from Yellowstone National Park have led to substantial insights into the water-rock interactions here and implications for other geothermal areas. New sampling and analytical methods have been developed and tested for trace elements. Quantitative measurements were obtained for changes in redox species of S, Fe, As, Sb, and Hg during outflow of thermal waters in which biotic and abiotic reactions play important roles. Fluoride speciation calculations were confirmed with ion-selective electrode measurements. The fate of contaminants, especially As and F, from thermal features in major rivers revealed no significant attenuation during downstream transport. Continuous monitoring for heat flux using year-round conductivity measurements was established. Testing of the “Multiple Equilibria Geothermometer” was achieved with high-quality, long-term data from Ojo Caliente, a continuously flowing hot spring. Yellowstone continues to be an outstanding field laboratory for expanding our knowledge of thermal water-rock interactions.
Contamination risk assessment of the Transboundary Zeravshan River using chemical and isotopic studies
Authors: Normatov Parviz , Normatov Inom
Published: June 2019

The results of chemical and isotope analyses of water of the Zeravshan River are presented. Results show that the low salinity of the river water in the upstream reach is formed mainly by water dissolution of minerals in natural rocks, i.e. the existence of a water-rock interaction process. The detection of heavy cations in the composition of the river water is due to their transport long distances in the form of microparticles by wind and accumulation in snow cover and glaciers. During the melting of snow and glaciers, and during rain events, pollutants are carried by streams, small rivers, and finally by Zeravshan River that distributes the pollutants over long distances.
The “Antica Fonte” of Boario (Italy): an hydrochemical and isotopic investigation in support of mineral water development
Authors: Sacchi Elisa , Paolucci Vittorio , Tedesco Dario , Oster Harald
Published: June 2019

The “Antica Fonte” mineral water is a valuable resource with well-known therapeutic effects due to its high magnesium and sulphate contents. Hydrochemical and isotopic data indicate that the water is recharged at an elevation exceeding 1000 m asl, derives its mineral content by dissolution of Triassic gypsum and dolomite, and partially mixes with present day recharge from the alluvial aquifer. The results of this investigation provide valuable information for a sustainable development of the resource.
The influence of hydrothermal activity during the origin of Co-rich manganese crusts of the N-W Pacific
Authors: Mikhailik Pavel , Khanchuk Alexandr , Mikhailik Evgenii , Ivanova Yuliya , Blokhin Maxim
Published: June 2019

The distribution of cobalt, vanadium, cadmium and molybdenum in the mineral fractions of the Co-rich manganese crusts (CMC) from Zubov and Govorov Guyots is considered. It is shown that the concentrations of cobalt in the ferrous fraction, and vanadium, cadmium in the manganese fraction indicate the ability of the CMC to record the rejuvenated volcanism in the N-W Pacific.
Experimental study of multicomponent diffusion in low permeable sediments
Authors: Lekhov Vladimir , Lekhov Alexei
Published: June 2019

Diffusion coefficients for Na+ and distribution coefficients for Cs+, Ba2+, Ni2+, CO2+, Sr2+ were measured on low permeable samples (3 cm diameter, average length 7 cm) from the deep disposal site Siberian Chemical Combine (SSC) using the end-diffusion technique. The direction of diffusion was perpendicular to bedding. Special equipment for experiment were designed and constructed. Two types of concentration observation were used. For non-sorbing Na+ in time used EC sensors and length distribution of sorbed elements. The synthetic solution used in the experiments was a model of low-activity contaminant of the SSC, and consist NaNO3 (25 g/l) and nitrate compounds: Cs+, Ba2+, Ni2+, Co2+, Sr2+ (100 mg/l each). The measured values of the effective diffusion coefficients De) for Na+ from 7.60×10-7 to 1.51×10-5 m2/day and volumetric dimensionless distribution coefficients (Kdρ) are: Cs+ from 0.21 to 22.1, Ba2+ from 1.1 to 1.45, Ni2+ from 0.3 to 16.4, Co2+ from 1.98 to 24.7, Sr2+ from 1.9 to 14.3. The values of the diffusion coefficient show a large degree of variability. The diffusion coefficients of non-sorbing Na+ measured in this study are in good agreement with pore-scale diffusion simulation on microtomography data.
Sources and accumulation of 7Be, 210Pb and 137Cs isotopes in the annual needles of larch and cedar in Novy Urengoy region (Arctic part of Western Siberia)
Authors: Belyanin Dmitriy , Vosel Yuliya , Mezina Kseniya , Melgunov Mikhail , Kropacheva Marya , Shcherbov Boris , Rubanov Maksim , Zhurkova Inna
Published: June 2019

Annual needles of larch and cedar were sampled in the tundra zone of the Arctic part of Western Siberia in order to determine 7Be, 210Pb and 137Cs specific activities. Higher concentrations of 137Cs in the needles of cedar relative to the needles of larch can be associated with a clear difference in the properties of accumulation and translocation of caesium among these species. Higher concentrations of 7Be and 210Pb in the needles of larch relative to cedar needles and close isotopic ratios (7Be/210Pb) are probably due to more efficient aerosol deposition on vegetative canopies of larch.
Isotopic characteristics (δ18O and δD) of surface and groundwater as an additional tool for searching quality drinking water (Western part of Novosibirsk Region, Russia)
Authors: Shemelina Olga , Sanchaa Aydisa , Faguet Alexey
Published: June 2019

Lack of quality drinking water is a problem for the western part of the Novosibirsk Region (Russia), where the total mineralization of water varies from 1.5 to 3-4 g/L and sometimes higher. The search for near-surface aquifers with high-quality groundwater can be successfully carried out using electrical tomography. To understand the relationship between groundwater of different depths, the isotopic characteristics (δ18O and δD) of the waters of existing wells was studied. The groundwater studied is likely to have a common origin.
Cl/Br and δ37Cl evolution in seawater expelled during the compaction of MX-80 smectite
Authors: Strydom Jessica , Eggenkamp Hans , Sterpenich Jérôme , Agrinier Pierre , Richard Antonin , Grgic Dragan , Gaire Patrick , Mosser-Ruck Régine , Gaucher Eric C.
Published: June 2019

During a high pressure (up to 150 MPa) high temperature (up to 150°C) compaction experiment of MX-80 smectite equilibrated with ocean water, it was found that the Cl and Br concentrations in the expelled solution are progressively being decreased while simultaneously being increased in the compacted clay. This significant retention of Cl and Br in the pore water of the compacted clay is indicative of ultrafiltration by the clay. Despite the size difference between the two anions no significant chemical partitioning between Cl and Br is observed in the expelled water. The δ37Cl value of the expelled water shows a sharp decrease (from -0.1 ‰ down to -0.5‰) during the first steps of compactions (between 45MPa – 21°C and 65MPa – 30°C) and then remains stable until 125MPa – 120°C. The largest impact on anion and stable isotope composition is seen during the earlier phases of the compaction. It is supposed that the surface chemistry of the clay in combination with decreasing porosity result in re-equilibration of compressed and overlapping diffuse double layers which in part, drive the anion and δ37Cl evolution.
Heavy metals and Zn isotope ratios in the snow of the Karabash copper smelting area (Southern Urals, Russia)
Authors: Udachin Valery , Streletskaya Maria , Kiseleva Daria , Zaitseva Maria , Aminov Pavel , Udachin Nikolay , Blinov Ivan
Published: June 2019

This work presents the first results of winter fieldworks aimed at the assessment of heavy metal content and Zn isotope composition in the snow cover of a smelting area in South Ural. Twenty one snowpacks were sampled at the end of the winter 2018 in the vicinity (1.0-95 km) of the copper smelter of the Karabash town (South Ural, Russia). The snow samples were analyzed for major and trace element composition using ICP-MS and ICP-OES techniques. Zn isotope analysis was performed by MC-ICP-MS with preliminary chromatographic purification. pH and water hardness values were obtained as well. Zn, Cu, Pb, Cd and Sr enrichment factors were calculated. The contaminant particles in snow were established to have been derived from the technogenic source through the distances up to 95 km from the industrial smelting area.
Pyroelectric effect in lead zirconate titanate/polyurethane composite for thermal energy harvesting
Authors: Tabbai Yassine , Belhora Fouad , El Moznine Reddad , Hajjaji Abdelowahed , El Ballouti Abdessamad
Published: June 2019

We deal with the thermal energy which is one of the ambient energy sources surely exploitable, but it has not been much interest as the mechanical energy. In the last decades, direct energy conversion devices received particular attention because of the need to develop flexible systems, autonomous and self-powered. The energy harvesting aims to make the systems, autonomous in terms of energy and to contribute to sustainable development by the total respect of the environment. In this paper, our aim is to use thermal energy and show that it's an important source for producing the electrical energy through pyroelectric effect: first, elaborate charged polyurethane (PU) with different proportions (20%, 30% and 40%) of lead zirconate titanate (PZT), then to use those PZT/PU composites as a pyroelectric energy harvesting systems. Secondly, the optimization of energy harvesting and storage. The PZT/PU composite prepared is considered as one of the most promising composites for energy harvesting systems, due its various advantages, such as mechanical flexibility, high temperature sensitivity, low cost as well as its high electro-active functional properties. The current generated by all samples for temperature fluctuations over a period of time in the order of 140 s have been rectified and stored in a charge capacitor of 1μF. The stored energy can reach a maximum value in the order of 14μW for a composite loaded with 40% PZT. Therefore, these composites show an interesting potential to be used in various applications. These results shed light on the thermoelectric energy conversion by a new composite of PZT/PU having the pyroelectric property.
Den Fit optimieren – Person Environment Occupation (PEO) Model
Authors: le Granse Mieke
Published: June 2019

Das Ergotherapiemodell PEO verdeutlicht auf anschauliche Weise die Interaktion zwischen einer Person, ihrer Umwelt und ihrer Betätigung. Ihm liegt der Gedanke zugrunde, dass, je größer die Schnittmenge – der Fit – der drei Anteile ist, sich ein Mensch umso besser betätigen kann. Damit bildet PEO die Grundlage für ergotherapeutisches Denken und weitere Modelle.
ACTIVATION AND INACTIVATION OF PURIFIED HUMAN FACTOR VIII BY THROMBIN
Authors: Sewerin K , Lundin A , Hellström E , Larsen K , Sandberg H
Published: June 2019

Highly purified human factor VIII was activated by human thrombin. The factor VIII material used showed variation in molecular weight and was separated into one heterogeneous form with a molecular weight ranging from 280 to 185 kDa and into one homogeneous 170 kDaform. Incubation of the (280-185) kDa form of factor VIII with thrombin resulted in proteolytic degradation of the heavy chain and formation of a 90 kDa peptide chain. This chain was further split intoone 52 kDa and one 43 kDa peptide chain, as was the 90 kDa chain pesent in the 170 kDa form of factor VIII. The light chain of 80 kDa was split into a 70 kDa peptide chain. The change in peptide composition was followed by scanning and integration of SDS-PAGE gels on samples from the activation of both forms of factor VIII with thrombin. No strict relationship between factor VIII activity and degradation or formation of a new peptide chain was seen.

When factor VIII bound to von Willebrand factor matrix was incubated with thrombin, activated factor VIII was released. The released material consisted mainly of a 90 kDa and a 70 kDa peptide chain, but the presence of the 52 and 43 kDa peptide chains increased with the passage of time. The concentration of Ca2+ ions was of great importance for the degree and rate of activation. A high concentration of CaCl2 resulted in a lower degree of activation but also slower inactivation of the factor Villa formed. However, no permanent stabilization of factor Villa was noted at either low or high concentrations of CaCl2.

Inhibition or removal of thrombin from the factor VIII system, by the use of protease inhibitors or matrix bound thrombin, did not prevent the loss of factor VIII activity following the activation. Thepeptide composition was stabilized, however, when thrombin was removed. This indicates that the inactivation of factor Villa is due to an intramolecular change in the factor VIII molecule.
DNA POLYMORPHISMS IN OR LINKED TO THE FACTOR VIII GENE IN CHINESE
Authors: Chan Vivian , Liu V W S , Wong A C K , Chan T K
Published: June 2019

78 unrelated X chromosomes from Southern Chinese (56 normal and 22 haemophiliac) were studied. DNA was restricted by Bel I, Bgl I or Taq I and hybridized to 3' factor VIII:C cDNA probe (5 kb, Chiron) or St 14.1 probe(3 kb, Oberle &Mandel) by standard techniques. The intragenic Bel I polymorphic site was positive in 82%, while Bgl I polymorphic site was positive in all. Thus, 29.5%(2 x×0.82 × 0.18) of Chinese females carried the Bel I polymorphism. Asto the Taq I polymorphism in the closely linked DXS52 DNA segment, the incidences for the various alleles were :System I - allele (3) 10.2%, (4) 2.6%, (5) 2.6%,(6) 17.9%, (7) 21.8% and (8) 44.9% System II - α a allele 56%, 6 allele 44%. Approximately 80% of females were heterozygous for two different alleles. Hence the Bel I and Taq I polymorphisms can be used to track the defective factor VIII gene for carrier detection and prenatal diagnosis. Furthermore, their frequencies in the Chinese are different from those previously reported in other ethnic groups.
ROUTINE MONITORING OF THE β-PROPIOLACTONE/UV STERILIZATION PROCEDURE USING BACTERIOPHAGES
Authors: Dichelmüller H , Stephan W
Published: June 2019

Cold sterilization of plasma or plasma derivatives such as the serum preserve Biseko® and coagulation factor concentrates by β-Propiolactone (β-PL)/UV has been demonstrated in various studies to be effective in inactivation of Hepatitis viruses and HIV. The methods used in these studies are not applicable in routine monitoring of sterilization processes, as chimpanzees must be involved in the titration of Hepatitis B or NANB viruses.

For routine monitoring of the sterilization efficacy we therefore developed a test system using four types of bacteriophages: Øx 174, Øe, Kappa and f2. Using these bacteriophages in 88 single tests, sterilization efficacy was regularly monitored during the period fran 1981 to 1986. For these tests samples were drawn from pooled human plasma, spiked with bacteriophages and subjected to the cold sterilization procedure under identical conditions and apparative equipenent, but strictly separated fran the production process. By treatment with β-Propiolactone and UV all bacteriophages were inactivated by more than 6.7 log10, independent from size or genom structure. This inactivation is in the range of inactivation of Hepatitis B virus by β-PL/UV as a relevant pathogenic virus. During this six year period of monitoring no significant alternations in sterilization efficacy were observed, indicating a constantly safe inactivation rate for numerous production lots and for many years of production.
NORMAL IN VIVO KINETICS OF FACTOR VIII (F VIII) AND FACTOR IX (F IX) TREATED WITH TRI (N-BUIYL) PHOSPHATE (TNBP) AND TWEEN 80 FOR INACTIVATION OF VIRUSES
Authors: Baumgartner C , Perret B A , Meili E , Furlan M , Friedli H , Morgen-thaler J J
Published: June 2019

Heat treatment has been cxxnmonly used for the sterilisation of coagulation factor concentrates. This causes, however, considerable loss of coagulation factor activity? therefore alternative methods have been developed. Two new virus-inactivated coagulation factor preparations were recently introduced by our institution. Their manufacturing procedure includes a lipid solvent extraction step: The cryoprecipitate (F VIII preparation) or the first DEAE eluate (F IX preparation) is incubated with 0.3 % TNBP and 1 % Tveen 80 at 24°C for at least 12 hours. (Horowitz, Transfusion 25 : 516-522, 1985). Single doses of these preparations (F VIII: median 20.5, range 6-33 U/kg, F IX: median 25, range 9-46 U/kg body weight) were given intravenously to 28 hemophilic patients with minor or no bleeding. F VIII or F IX levels in plasma were determined before and at intervals up to 48 h after injection. The recovery was calculated from the maximum increase of activity and an plasma volume of 41 ml/kg body weight. The plasma half life was calculated according to the procedures described by Morfini (Thrcmb. Res. 42: I-III, 1986). Results are shown in the table below.

No side effects were recorded. Hemostasis was satisfactory in all patients with bleedings (n = 13). These results are within the range expected for conventional and heat treated F VIII and F IX preparations. We conclude that the lipid solvent extraction procedure as used here does not influence the in vivo kinetics and the function of F VIII and F IX and does not induce any acute toxicity.
INTERACTIONS OF HUMAN PLATELETS WITH COAGULATION FACTORS IX AND IXa
Authors: Ahmad S S , Rawala R , Walsh P N
Published: June 2019

To elucidate the molecular mechanisms underlying the platelet contribution to the activation of factor IX (FIX) and FX, we have previously reported the presence of specific, high-affinity binding sites on activated platelets for FIX and FIXa (Blood 66:300a, 1985; Circulation, 74:11-238, 1986). Since both FIX and FIXa bind to a common site on thrombin-activated platelets in the presence of Ca++ ions, it is important to determine whether saturation of platelet binding sites with FIX would prevent F-IXa binding. We have therefore made direct comparisons of F-IX and F-IXa binding and examined the functional consequences of F-IXa binding in F-X activation. Gel-filtered platelets (GFP) were incubated with 125I-FIX or 125I-FlXa and centrifuged through silicone barriers to separate GFP from unbound proteins. Optimal binding of both FIX and FIXa occurred in the presence of CaCl2 (5 mM) and thrombin (0.1 U/ml), with maximal binding in 10-15 min at 37°C. Binding of both proteins was specific since a 130-fold excess of FIX or FIXa inhibited FIX binding >85% and excess FIXa inhibited FIXa binding >85%, whereas excess FIX inhibited FIXa binding to a lesser extent, and excess high Mr kininogen, FXI, FX, prothrombin, and prekallikrein inhibited binding <30%. Binding of both FIX and FIXa was rapidly reversible and saturable. The number of FIXa binding sites (551 + 48 per platelet) was significantly (p < 0.001) higher than for FIX (306 + 57). Dissociation constants (Kd) were 2.57 +0.14 nM for FIXa and 2.68 + 0.25 nM for FIX. However, the concentration of FIXa required for half-maximal rates of FX activation in the presence of FVIIIa and thrombin-activated GFP was approximately 0.1 nM. This suggests that the FIXa receptors functionally active in FX activation may bind FIXa >20-fold more tightly than indicated by equilibrium binding studies, and that FIXa binding studies should be carried out in the presence of large molar excesses of FIX. We conclude that FIX and FIXa bind to a coupon site on thrombin-activated platelets in the presence of Ca ions, and that FIXa also binds to a site distinct from that for FIX. FIXa binding to platelets appears to contribute to F-X activation.
FACTOR VIII/VON WILLEBRAND FACTOR COMPLEX: ONLY THE 440 000 SUBUNIT OF ENDOTHELIAL CELL-DERIVED VON WILLEBRAND FACTOR FORMS A COMPLEX WITH PURIFIED PLASMA FACTOR VIIIC
Authors: Pötzsch B , Delvos U , Anders E , Heimburger N , Müller-Berghaus G
Published: June 2019

Von Willebrand Factor (vWF) circulates in plasma as a series of multimers with moleculag weight ranging from M = 0.44 x 106 up to more than 20 x 106 . Besides the mediation of platelet adhesion to exposed subendothelium, the protein plays an important role in the stabilization and the transport of Factor VIIIC (FVIIIC). In the present study the interaction between FVIIIC and vWF was studied by recombination experiments. vWF was isolated from cultured human umbilical vein endothelial cells by immunoprécipitation. This source of vWF ascertained, that it was free of FVIIIC as indicated by the absence of FVIIIC activity as well as FVIIIC antigen. FVIIIC was prepared by immunoabsorption from human plasma yielding an activity of 1600 IJ/mg. SDS-PAGE analysis showed two main bands at Mr= 0.28 x 106 and 0.18 x 106 , respectively. vWF-multimers were separated by SDS agarose gel electrophoresis and were electrophoretically transferred onto nitrocellulose sheets. After extensive washing, the sheets were incubated for 12 h with 20 U/ml FVIIIC in PBS, pH 7.4, containing 2.5 mM calcium chloride. Subsequently, associated FVIIIC was detected by autoradiography with a 125-I-labelled monoclonal mouse anti-(human FVIIIC) antibody. The results of recombination experiments exclusively showed prominent staining of the Mr= 0.44 x 106 vWF band in the autoradiography. However, proteolytically degraded FVIIIC with partly retained procoagulant activity did not show a positive stain. The results indicate that an intact FVIIIC molecule and the smallest multimer of vWF are required for the formation of a stable FVIII/vWF complex.
EFFECT OF DDAVP ON MYOCARDIAL INFARCT SIZE
Authors: Pabón P , Vicente V , Alberca I , Martin Luengo C , Lopez Borrasca A
Published: June 2019

Infarct size, estimated by electrocardiographic changes (the QRS Scoring System, developed by Wagner et al, Circulation 65,342, 1982) and enzymatic analysis (creatinine kinase, CK) was studied in 45 patients with no history of previous infarcts. 25 received an intravenous dose of DDAVP (0.3 ug/kg) and 20 received a placebo solution (saline). The time between the onset of symptoms and DDVAP administration was less than 12 hours. The results showed no significant differences between the two groups in maximal or acumulative activity of creatinine kinase (CKr) or the QRS score peak. However, in patients with a mean evolution time of less than 1 hour, the CK peak was significantly lower in the DDAVP group than in the placebo group (p<0.05). Furthermore the percent of maximal increase in the QRS score was lower in the DDAVP group than in the patients receiving the placebo (p=0.1). On admission, the fibrinolytic activity of euglobulin fractions (measured by fibrin plates) was higher in the patients in both groups than in a group of healthy subjects (n=40). Also, DDAVP significantly increased fibrinolyric activity whereas no changes were found in patients receiving the placebo. The mean CKr value was lower in patients with an increase in fibrinolysis than in those who showed no changes in it. Finally, in the DDAVP group the QRS score peak was strongly dependent on the initial QRS score and, regarding this, our results suggest that small infarcts on admission may represent a potential indication for DDAVP therapy.
LOSS OF IMMUNE TO RECALL ANTIGENS IN THERE HIV+ HEMOPHILIC CHILDREN
Authors: GOMPERTS E D , WEINBERG K
Published: June 2019

Three children with severe inherited bleeding disorders have been followed for a number of years at this center. One child (DOB 3/71) initially presented with mild hemophilia A, (Factor VIII 6%). He subsequently developed an inhibitor to Factor VIII (maximum 45 B. U.) and seroconverted to HIV+ Status 12/83. In 12/86 he had virtually lost his antibody response to infused Factor VIII (previously withheld), with a maximum increase in inhibitor titre to1 B. U. on challenge. In addition, his antitetanus antibody titre was very low at 0.01 u/ml earlier in theyear. His absolute T4 cell number at this time was very low at 64 and did not respond to skin antigen testing to PPD, tetanus and Candida.

The second patient (severe hemophilia A DOB 7/76) had seroconvertedto HIV+ Status in 9/78. This child has lost his a-HBs seropositive status with an absolute T4 count of 239. His current anti-tetanus titre is 0.01 u/ml.

The third patient (von Willebrand disease, Type III, DOB 7/74) seroconverted to HIV+E status by 5/83. His T4 absolute numbers have fallen to 53. His anti-tetanus antibody titre has fallen to extremely low levels (0.01 u/ml), and this failed to respond to re-immunization with tetanus toxoid. These three patients indicate that previously immunized children may lose their immune status and their ability to respond to recall antigens. It is pertinent to note that lymphocytes from all 3 patients failed to respond mitogenically in vitro to tetanus antigen pari passu with the observed very low anti-tetanus antibody titres. These phenomena would indicate that these patients are probably susceptible to previously preventable infectious agents including poliovirus, measles, mumps, rubella, diphtheria, tetanus and hepatitis B virus.
EXPERIMENTAL THROMBUS FORMATION AND HAEMOSTASIS OF DIFFERENT LOW MOLECULAR WEIGHT HEPARINS AND DOSAGES
Authors: Zimmerman R A , Rieger C T , Hübner K , Harenber C W , Kübler W
Published: June 2019

Low molecular weight heparin induces a higher anti factor Xa (a-Xa) and a lower antithrombin activity in plasma in comparison to conventional heparin. From this constellation a more pronounced antithrombotic effect and a minor incidence of bleeding Complications has been suggested.

Therefore the antithrombotic activity of heparins was studied in a standardized experimental thrombosis model in rabbits. Three low molecular weight heparins with a mean molecular weight of 4.200 (heparin I),4.000 (heparin II),4.600 Dalton (heparin III) and standard heparin were tested at different dosages in 120 experiments. In the first series the dose of 60 anti Xa units (a-Xa U) given initially and 60 a-Xa U/kg/h induced a reduction of the thrombus size by 40 % (heparin I),37 % (heparin II) and 53 % (heparin III) and a prolongation of the aPTT to 45 (heparin I),66 (heparin II) and 79 sec (heparin III). The a-Xa activity was minor than 0.1 U/ml. In the second series heparins were given to aim at an a-Xa activity of 0.2-0.3 U/ml. Thereby the thrombus formation could be reduced by 84 % (heparin I), 62 % (heparin II) and 39 % (heparin III). aPTT and a-Xa activity were measured at 65.5 sec and 0.22 a-Xa U/ml (heparin I),67.3 sec and 0.3 a-Xa U/ml (heparin II) and 67.5 and 0.31 a-Xa U/ml (heparin III),respectively. In the third series the increase of the a-Xa activity to more than 0.3 U/ml showed no further reduction of the thrombus formation by heparin I, while heparins II and III already at this level reachedthe antithrombotic activity of heparin I.

Our data on three different low molecular weight heparins demonstrate that already a heparin level ranging at a minimal a-Xa activity induces a clear and statistically significant antithrombotic effect. A higher heparin dosage with higher a-Xa activity increases the antithrombitic effect. At a level of 0.2-0.3 a-Xa U/ml an obvious and maximum effect could be reached, but the further elevation of the a-Xa activity produced no further antithrombotic action.