The Middle Jurassic A6 Anomaly is located 30 km southeast of Eskay Creek, north-central British Columbia and consists of thick, altered felsic igneous rocks overlain by a mafic volcano-sedimentary ...package. Lithogeochemistry on igneous rocks, X-ray diffraction on altered felsic units, and electron probe microanalysis and secondary ion mass spectrometry on illite and quartz were applied to explore the volcanogenic massive sulfide (VMS) potential, characterize alteration, and determine fluid conditions at the A6 Anomaly. Lithogeochemistry revealed calc-alkaline rhyodacite to trachyte of predominantly FII type, tholeiitic basalts with Nb/Yb < 1.6 (i.e., Group A), and transitional to calc-alkaline basalts and andesites with Nb/Yb > 2.2 (i.e., Group B). The felsic units showed weakly to moderately phyllic alteration (quartz–illite with minor orthoclase and trace chlorite–pyrite–calcite–barite–rutile). Illite ranged in composition from illite/smectite (K = 0.5–0.69 apfu) to almost endmember illite (K = 0.69–0.8 apfu), and formed from feldspar destruction by mildly acidic, relatively low temperature, oxidized hydrothermal fluids. The average δ18O composition was 10.7 ± 3.0‰ and 13.4 ± 1.3‰ relative to Vienna Standard Mean Ocean Water for illite and quartz, respectively. Geothermometry involving illite composition and oxygen isotope composition on illite and quartz yielded average fluid temperatures of predominantly 200–250 °C. Lithogeochemical results showed that the A6 Anomaly occurred in a late-Early to Middle Jurassic evolving back-arc basin, further east then previously recognized and in which transitional to calc-alkaline units formed by crustal assimilation to enriched Mid-Ocean Ridge Basalt (EMORB) (i.e., felsic units, Group B), followed by thinning of the crust resulting in tholeiitic normalized MORB basalts (i.e., Group A) with a minor crustal component. The alteration assemblage is representative of distal footwall alteration, and metal transport in this zone was limited despite favorable temperature, pH, and redox state, indicating a metal depleted source (i.e., felsic units).
The two-dimensional pixel detector JUNGFRAU is designed for high performance photon science applications at free electron lasers and synchrotron light sources. It is developed for the SwissFEL ...currently under construction at the Paul Scherrer Institut, Switzerland. The detector is a hybrid pixel detector with a charge integration readout ASIC characterized by single photon sensitivity and a low noise performance over a dynamic range of 10 super(4) 12 keV photons. Geometrically, a JUNGFRAU readout chip consists of 256x256 pixels of 75x75 mum super(2). The chips are bump bonded to 320 mum thick silicon sensors. Arrays of 2x4 chips are tiled to form modules of 4x8 cm super(2) area. Several multi-module systems with up to 16 Mpixels per system will be delivered to the two end stations at SwissFEL. The JUNGFRAU full scale readout ASIC and module design are presented along with characterization results of the first systems. Experiments from fluorescence X-ray, visible light illumination, and synchrotron irradiation are shown. The results include an electronic noise of ~50 electrons r.m.s., which enables single photon detection energies below 2 keV and a noise well below the Poisson statistical limit over the entire dynamic range. First imaging experiments are also shown.
An octahedral PtNi catalyst has been evaluated for direct ethanol fuel cells (DEFC) by measuring its performance and product distribution in a proton exchange membrane electrolysis cell. This avoids ...errors due to the chemical reaction between ethanol and oxygen that occurs in a DEFC. The performance of the PtNi/C catalyst at low potentials was similar to that of a commercial Pt/C catalyst, while its selectivity for complete oxidation of ethanol to carbon dioxide was significantly higher. For example, at 0.2 V vs. a hydrogen-producing cathode the faradaic yield of CO2 was 73% at PtNi/C at an average current of 5.6 mA, but only 55% at Pt/C, at 5.1 mA. Consequently, the PtNi/C catalyst would provide higher DEFC efficiencies than Pt/C, or commercial PtRu/C. The voltammetric behaviors of PtNi/C and Pt/C have also been compared in a liquid electrolyte at ambient temperature, where it was found that the activity of the PtNi/C for ethanol oxidation was improved greatly by heating in acetic acid. This removes surface Ni and capping agents and greatly improved CO tolerance. However, the superior CO tolerance of the cleaned PtNi/C relative to Pt/C was not reflected in polarization curves measured at 80 °C in PEM cells.
•Octahedral PtNi is more efficient than Pt for ethanol oxidation in fuel cells.•PtNi is more selective for breaking the C-C bond to produce CO2.•The higher stoichiometry at low potentials increases efficiency in DEFCs.•Heating of the PtNi catalyst in acetic acid changes its activity and selectivity.•Cyclic voltammetry at RT is not a good indicator of performance in a DEFC.
Abstract
The TAIGA astroparticle observatory is progressing with the
deployment of new detector stations. The Tunka-Grande —
scintillation counter array of the observatory expands with the new
...TAIGA-Muon stations. Several simulation studies were conducted for
optimisation of the new station positioning and
performance. Extensive air showers induced by gamma quanta or a
proton in the range from 100 TeV to 1 PeV at a zenith angle of 0°
were used for these studies. Based on the developed simulation, the
capabilities of identification of high energy extensive air showers
were studied. The soil thickness, the detector and station
positions, the lowest measurable energy range of the cosmic rays,
and different methods of air shower identification were
investigated.
The aim of the study was to investigate the influence of oral rehydration solutions (ORS) on milk clotting, abomasal pH, electrolyte concentrations, and osmolality, as well as on the acid-base status ...in blood of suckling calves, as treatment with ORS is the most common therapy of diarrhea in calves to correct dehydration and metabolic acidosis. Oral rehydration solutions are suspected to inhibit abomasal clotting of milk; however, it is recommended to continue feeding cow's milk or milk replacer (MR) to diarrheic calves to prevent body weight losses. Three calves with abomasal cannulas were fed MR, MR-ORS mixtures, or water-ORS mixtures, respectively. Samples of abomasal fluid were taken before and after feeding at various time points, and pH, electrolyte concentrations, and osmolality were measured. The interference of ORS with milk clotting was examined in vivo and in vitro. To evaluate the effects of ORS on systemic acid-base status, the Stewart variables strong ion difference (SID), acid total (Atot), and partial pressure of CO2 (pCO2) were quantified in venous blood samples drawn before and after feeding. Calves reached higher abomasal pH values when fed with MR-ORS mixtures than when fed MR. Preprandial pH values were re-established after 4 to 6h. Oral rehydration solutions prepared in water increased the abomasal fluid pH only for 1 to 2h. Oral rehydration solutions with high SID3 (Na+ + K+ − Cl−) values produced significantly higher abomasal pH values and area under the curve data of the pH time course. Caseinomacropeptide, an indicator of successful enzymatic milk clotting, could be identified in every sample of abomasal fluid after feeding MR-ORS mixtures. The MR-ORS mixtures with SID3 values ≥92 mmol/L increased serum SID3 but did not change venous blood pH. Oral rehydration solutions do not interfere with milk clotting in the abomasum and can, therefore, be administered with milk. In this study, MR-ORS mixtures with high SID3 values caused an increase of serum SID3 in healthy suckling calves and may be an effective treatment for metabolic acidosis in calves suffering from diarrhea.
The cytogenetic hypothesis that common fragile sites (cFSs) are hotspots of cancer breakpoints is increasingly supported by recent data from whole-genome profiles of different cancers. cFSs are ...components of the normal chromosome structure that are particularly prone to breakage under conditions of replication stress. In recent years, cFSs have become of increasing interest in cancer research, as they not only appear to be frequent targets of genomic alterations in progressive tumors, but also already in precancerous lesions. Despite growing evidence of their importance in disease development, most cFSs have not been investigated at the molecular level and most cFS genes have not been identified. In this review, we summarize the current data on molecularly characterized cFSs, their genetic and epigenetic characteristics, and put emphasis on less-studied cFS genes as potential contributors to cancer development.
Pyrolysis oil produced from forestry residues is used as a low-grade fuel in applications such as heating oil. However, the high water and acid content can lead to fuel instability, phase separation, ...poor lubrication, and corrosion. In this work, pervaporation has been studied as a process to simultaneously upgrade a pyrolysis oil produced from Canadian softwood bark to meet a boiler fuel standard and extract value-added chemicals. Commercial polyacrylonitrile-supported polyvinyl alcohol membranes from DeltaMem AG were used at temperatures of 60 and 80 °C to separate water and volatile organic components, including methanol, acetic acid, and acetol. A design of experiment study was used to define the range of operating conditions. A temperature of 80 °C and a low feed flow rate of 0.1 mL min−1 resulted in the highest quality oil. The upgraded pyrolysis oil (pervaporation retentate) showed an increased heating value from incomplete combustion to 16.07 MJ kg−1 and the water content was lowered from 70.2 wt% in the feedstock to 21.4 wt%, demonstrating the potential for this process on a larger scale.
•Pyrolysis oil from sawmill residue (bark) has been processed by pervaporation.•Commercial polyvinyl alcohol membranes produced two value-added process streams.•The retentate was a low viscosity oil meeting the ASTM boiler fuel standard.•The aqueous permeate contained significant quantities of methanol and acetic acid.
In this paper we present an evaporation concept which enables access to very low substrate temperatures for the fabrication of CdTe solar cells at promising solar cell efficiencies. CdTe layers were ...deposited at substrate temperatures of 300°C to 190°C and processed to solar cells with efficiencies of about 12% and 9%, respectively. A further reduction of the substrate temperature abruptly results in non-working solar cells. That effect is discussed in terms of the morphology of the absorber layers. The corresponding solar cell characteristics are compared to cells which were prepared by the conventional close space sublimation method.
► We developed a method for the deposition of CdTe layers at very low temperatures. ► The device has similar evaporation characteristics as conventional devices. ► Solar cells with good efficiencies are prepared at very low substrate temperatures. ► At substrate temperatures of less than 190°C the efficiencies abruptly vanish. ► The presented concept is easily applicable to an industrial scale.
The physics motivations and advantages of the new TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) detector are presented. TAIGA aims at gamma-ray astronomy at energies ...from a few TeV to several PeV, as well as cosmic ray physics from 100 TeV to several EeV. For the energy range 30 – 200 TeV the sensitivity of 10 km
2
area TAIGA array for the detection of local sources is expected to be 5 × 10
-14
erg cm
-2
sec
-1
for 300 h of observations. Reconstruction of the given EAS energy, incoming direction and its core position, based on the timing TAIGA-HiSCORE data, allows one to increase a distance between the IACTs up to 600-1000 m. The low investments together with the high sensitivity for energies ≥ 30-50 TeV make this pioneering technique very attractive for exploring the galactic PeVatrons and cosmic rays. At present the TAIGA first stage has been constructed in Tunka valley, 50 km West from the Lake Baikal. The first experimental results of the TAIGA first stage are presented.
Vertebrates develop distinct asymmetries along the left-right axis, which are consistently aligned with the anteroposterior and dorsoventral axes. The mechanisms that direct this handed development ...of left-right asymmetries have been elusive, but recent studies of mutations that affect left-right development have shed light on the molecules involved. One molecule implicated in left-right specification is left-right dynein (LRD), a microtubule-based motor protein. In the LRD protein of the inversus viscerum (iv) mouse, there is a single amino acid difference at a conserved position, and the lrd gene is one of many genes deleted in the legless (lgl) mutation. Both iv and lgl mice display randomized left-right development. Here we extend the analysis of the lrd gene at the levels of sequence, expression and function. The complete coding sequence of the lrd gene confirms its classification as an axonemal, or ciliary, dynein. Expression of lrd in the node at embryonic day 7.5 is shown to be symmetric. At embryonic day 8.0, however, a striking asymmetric expression pattern is observed in all three germ layers of the developing headfold, suggesting roles in both the establishment and maintenance of left-right asymmetries. At later times, expression of lrd is also observed in the developing floorplate, gut and limbs. These results suggest function for LRD protein in both ciliated and non-ciliated cells, despite its sequence classification as axonemal. In addition, a targeted mutation of lrd was generated that deletes the part of the protein required for ATP binding, and hence motor function. The resulting left-right phenotype, randomization of laterality, is identical to that of iv and lgl mutants. Gross defects in ciliary structure were not observed in lrd/lrd mutants. Strikingly, however, the monocilia on mutant embryonic node cells were immotile. These results prove the identity of the iv and lrd genes. Further, they argue that LRD motor function, and resulting nodal monocilia movement, are required for normal left-right development.
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