Search

Zechstein (Upper Permian) dolomitic grainstones saturated with high pressure natural gas (including N2, CH4 and CO2) are present in the roof of workings in the Rudna copper mine in SW Poland. Natural gas commonly occurs in Zechstein reefal carbonates but this is the first occurrence of gas in basinal facies of the Zechstein Limestone in Poland. The reservoir dolomites are thin (ca. 1m), with porosity of 2-15% and permeability of less than a few mD. Pore size and pore distribution was analysed using microscope observations, X-ray computed microtomography, mercury porosimetry and argon adsorption to investigate the dolomitic reservoir interval. The dolomites have variable reservoir properties, and stratigraphic traps with dimensions of several metres are present where high poro-perm dolo-grainstones are sealed by tighter dolomites. Geochemical data indicate that the methane and carbon dioxide present are derived from source rock intervals in the Kupferschiefer (Late Permian) and the Zechstein Limestone. The high content of nitrogen in the gas may be related to the thermal decomposition of Carboniferous organic matter. However, a biogenic origin for the nitrogen is also possible. [ABSTRACT FROM AUTHOR]

Magnetite nanoparticles have become a promising material for scientific research. Among numerous technologies of their synthesis, co-precipitation seems to be the most convenient, less time-consuming and cheap method which produces fine and pure iron oxide particles applicable to environmental issues. The aim of the work was to investigate how the co-precipitation synthesis parameters, such as temperature and base volume, influence the magnetite nanoparticles ability to separate heavy metal ions. The synthesis were conducted at nine combinations of different ammonia volumes - 8 cm3, 10 cm3, 15 cm3 and temperatures - 30°C, 60°C, 90°C for each ammonia volume. Iron oxides synthesized at each combination were examined as an adsorbent of seven heavy metals: Cr(VI), Pb(II), Cr(III), Cu(II), Zn(II), Ni(II) and Cd(II). The representative sample of magnetite was characterized using XRD, SEM and BET methods. It was observed that more effective sorbent for majority of ions was produced at 30°C using 10 cm3 of ammonia. The characterization of the sample produced at these reaction conditions indicate that pure magnetite with an average crystallite size of 23.2 nm was obtained (XRD), the nanosized crystallites in the sample were agglomerated (SEM) and the specific surface area of the aggregates was estimated to be 55.64 m2·g-1 (BET). The general conclusion of the work is the evidence that magnetite nanoparticles have the ability to adsorb heavy metal ions from the aqueous solutions. The effectiveness of the process depends on many factors such as kind of heavy metal ion or the synthesis parameters of the sorbent.

The Plasma Electrolytic Oxidation (PEO) process may be used to fabricate porous coatings on titanium. The ranges of voltages used in case of these plasma treatments are different. It has been found that for DC PEO processing the voltage must be higher than that in the case of AC PEO treatment. In addition, the shape and frequency of the voltage signal have also an influence. In the paper scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and glow discharge optical emission spectroscopy (GDEOS) were used to characterise obtained coatings. It was found that it is possible to obtain the porous coatings enriched with phosphorus and copper by use of AC-PEO at only 200 Vpp, while increasing the PEO voltage results in non-porous and cracked coatings. Based on GDEOS for 200 Vpp three sublayers were used, with ranges of 0-400, and 400-2400, and 2400-3600 seconds of sputtering time for first, and second, and transition sublayers respectively. XPS spectra for sample processed at 200 Vpp indicate in top 10 nm layer presence of titanium as Ti4+ and phosphorous as phosphates (most likely PO43–, HPO42–, H2PO4–, P2O73–).

Porous coatings on titanium may be obtained by AC or DC Plasma Electrolytic Oxidation (PEO) process. One has to point out that depending on the plasma treatment the ranges of voltages used are different. It has been found that for DC PEO processing the voltage must be higher than that in the case of AC PEO treatment. In addition, the shape and frequency of the voltage signal have also an impact. Produced coatings were examined with scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and glow discharge optical emission spectroscopy (GDEOS). It was found that it is possible to obtain the porous coatings enriched with phosphorus and copper by use of DC-PEO at 500, 575 and 650 VDC, whereas increasing the PEO voltage results in an increase of Cu/P (copper-to-phosphorus) atomic ratio. Furthermore, based on GDEOS data, three sublayers with different elements concentrations were detected ranging as follows 0-350, 350-2100, 2100-2900 seconds of sputtering time for 575 VDC. Based on XPS results the top 10 nm layer, consisted mainly of titanium (Ti4+), copper (Cu+ and/or Cu2+), and phosphates (PO43–, HPO42–, H2PO4–, P2O73–).

The introduction of the hydrogen economy, despite its obvious technological problems, creates a need for a significant number of niche-focused solutions, such as small-sized (10-100 W) fuel cells able to run on hydrogen of lesser purity than what is considered a standard in the case of PEMFCs. One of the solutions can be derived from the fact that an increase in the operational temperature of a cell significantly decreases its susceptibility to catalyst poisoning. Electrolytes suitable for the so-called medium temperature operational range of 120-400 °C, hence developed, are neither commercialized nor standardized. Among them, phosphate silicate protonically conductive glasses were found not only to reveal interestingly high levels of operational parameters, but also, to exhibit superior chemical and electrochemical stability over their polymeric counterparts. On the other hand, their mechanical properties, including cracking fragility, still need elaboration. Initial studies of the composite phosphate silicate glasses with uranyl-based protonic conductors, presented here, proved their value both in terms of application in fuel cell systems, and in terms of understanding the mechanism governing the charge transport mechanism in these and similar systems. It was found that whereas systems containing 10-20 wt% of the crystalline additive suffer from significant instability, materials containing 45-80 wt% (with an optimum at 60%) should be examined more thoughtfully. Moreover, the uranyl hydrogen phosphate was found to surpass its arsenate counterpart as an interesting self-healing behavior of the phase structure of the derived composite was proved.

This paper is focused on the determination of the physicochemical properties of a composite inorganic-organic modified membrane. The electrical conductivity of a family of glassy protonic electrolytes defined by the general formula (P 2 O 5 ) x (SiO 2 ) y , where x/y is 3/7 are studied by Alternating Current electrochemical impedance spectroscopy (AC EIS) method. The reference glass was doped with polymeric additives-poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA), and additionally with a titanium-oxide-based filler. Special attention was paid to determination of the transport properties of the materials thus modified in relation to the charge transfer phenomena occurring within them. The electrical conductivities of the 'dry' material ranged from 10 -4 to 10 -9 S/cm, whereas for 'wet' samples the values were ~10 -3 S/cm. The additives also modified the pore space of the samples. The pore distribution and specific surface of the modified glassy systems exhibited variation with changes in electrolyte chemical composition. The mechanical properties of the samples were also examined. The Young's modulus and Poisson's ratio were determined by the continuous wave technique (CWT). Based on analysis of the dispersion of the dielectric losses, it was found that the composite samples exhibit mixed-type proton mobility with contributions related to both the bulk of the material and the surface of the pore space.

Studies demonstrate that GRM, expressed by >60% of human melanomas, may be a therapeutic target. We performed a phase II trial of 100 mg PO bid of riluzole, an inhibitor of GRM1 signaling, in patients with advanced melanoma with the primary endpoint of response rate. Thirteen patients with GRM1-positive tumors were enrolled. No objective responses were observed, and accrual was stopped. Stable disease was noted in six (46%) patients, with one patient on study for 42 weeks. Riluzole was well tolerated, with fatigue (62%) as the most common adverse event. Downregulation of MAPK and PI3K/AKT was noted in 33% of paired tumor biopsies. Hypothesis-generating correlative studies suggested that downregulation of angiogenic markers and increased leukocytes at the active edge of tumor correlate with clinical benefit. Pharmacokinetic analysis showed interpatient variability consistent with prior riluzole studies. Future investigations should interrogate mechanisms of biologic activity and advance the development of agents with improved bioavailability., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)