High Oxygen Pressure Research Articles

Experimental Study on the Combustion Characteristics of Polyurethane Under High Pressure and Low Oxygen Environment

Closing the coal mine and injecting nitrogen, as a common fire fighting method, will form a high pressure and low oxygen environment in the closed coal mine. To investigate the fire risk of the rigid polyurethane (PU) foam under this environment, a series of experiments were carried out in the self-designed device. In the experiments, the oxygen concentration (pressure) changed from $${21}\%\, ({0.101}\,{\hbox {MPa}})$$ to $${16}\,{\%}\, ({0.133}\,{\hbox {MPa}})$$ , and the material thickness varied between $${3}\,{\hbox {cm}}, {4}\,{\hbox {cm}}$$ and $${5}\,{\hbox {cm}}$$ . PU’s flame speed, flame height and gas-phase temperature were obtained and analyzed from different aspects. The experimental results are as follows: (1) The effect of oxygen concentration reduction was stronger than that of pressure increase on flame speed. The critical heat flux of vertical flame propagation and the volume of carbon skeleton structure, which were influenced by the material thickness, affected the flame speed. (2) Under the influence of oxygen concentration and buoyancy of mixed gas in closed area, the normalized flame height showed a unique variation rule. (3) The final absolute pressure in the experimental equipment could be compared with the initial pressure to show the insufficiency of combustion. The maximum gas-phase temperature at $${3}\,{\hbox {cm}}$$ above the fuel surface showed different variation patterns, when the average optical density of soot particles were on the two sides with 200 (dimensionless number). The results illustrate that in the high pressure and low oxygen environment, reducing the oxygen concentration rapidly is the key to extinguishing the coal mine fire, although the increase in pressure will enhance the intensity of combustion.

Low temperature exchange bias study on Pr0.8Ca0.2MnO3/La0.3Ca0.7MnO3 system

Abstract Pr1-xCaxMnO3 with x = 0.2 is a ferromagnetic material at low temperature TC ∼ 130 K, and paramagnetic at higher temperatures, while La1-xCaxMnO3 with x=0.7 is antiferromagnetic material at low temperature TN ∼ 130 K. Bilayers with an antiferro/ferromagnetic (AF/FM) configuration based on manganites exhibit an interesting phenomenon known as exchange bias effect. Using a DC sputtering system at high oxygen pressure, we grew Pr0.8Ca0.2MnO3 (PCMO) and La0.3Ca0.7MnO3 (LCMO) thin films and Pr0.8Ca0.2MnO3/La0.3Ca0.7MnO3 (PCMO/LCMO) bilayers on (100) SrTiO3 substrates, to study the exchange bias effect in both systems (PCMO films and bilayers) at 10 K. Structural properties of samples were obtained by x-ray diffraction, reciprocal space maps, and transmission electron microscopy (TEM). Magnetic characterization was carried out by magnetic hysteresis loops measurements at 10 K. We found that PCMO thin films showed a shift in their hysteresis loops ∼80 Oe. However, the PCMO/LCMO bilayers displayed almost double of the shifting in the hysteresis loop ∼150 Oe. The additional shift with respect to the single layer could be associated to the interface interaction between PCMO and LCMO layers.

Disappearance of Superconductivity and a Concomitant Lifshitz Transition in Heavily Overdoped Bi2Sr2CuO6 Superconductor Revealed by Angle-Resolved Photoemission Spectroscopy**Supported by the National Key Research and Development Program of China under Grant Nos 2016YFA0300300 and 2017YFA0302900, the Strategic Priority Research Program (B) of Chinese Academy of Sciences under Grant Nos XDB07020300 and XDB25000000, the National Basic Research Program of China under Grant

By partially doping Pb to effectively suppress the superstructure in single-layered cuprate Bi2Sr2CuO6+δ (Pb-Bi2201) and annealing them in vacuum or in high pressure oxygen atmosphere, a series of high quality Pb-Bi2201 single crystals are obtained with Tc covering from 17 K to non-superconducting in the overdoped region. High resolution angle resolved photoemission spectroscopy measurements are carried out on these samples to investigate the evolution of the Fermi surface topology with doping in the normal state. Clear and complete Fermi surfaces are observed and quantitatively analyzed in all of these overdoped Pb-Bi2201 samples. A Lifshitz transition from hole-like Fermi surface to electron-like Fermi surface with increasing doping is observed at a doping level of ∼0.35. This transition coincides with the change that the sample undergoes superconducting-to-non-superconducting states. Our results reveal the emergence of an electron-like Fermi surface and the existence of a Lifshitz transition in heavily overdoped Bi2201 samples. This provides important information in understanding the connection between the disappearance of superconductivity and the Lifshitz transition in the overdoped region.

High pressure synthesis of a quasi-one-dimensional GdFeO3-type perovskite PrCuO3 with nearly divalent Cu ions.

A new perovskite-type cuprate PrCuO3 has been synthesized by high-pressure oxygen annealing. Synchrotron X-ray powder diffraction and absorption spectroscopy revealed that PrCuO3 crystallizes in the GdFeO3-type structure with cooperative Jahn-Teller distortion, forming one-dimensional chains of corner-shared CuO4 plaquettes with nearly divalent Cu ions.

Rapid Synthesis of Li<sub>2</sub>O-(Nb/Ta)<sub>2</sub>O<sub>5</sub>-TiO<sub>2</sub> Solid Solution Having Superstructure by Smart Processing Techniques

We successfully synthesized Li1+x-yM1-x-3yTix+4yO3 solid solutions (M = Nb or Ta, LMT, 0.07 ≤ x ≤ 0.33, 0 ≤ y ≤ 0.175) that have a superstructure. The materials formed a superstructure known as the M-phase, which is formed by the periodical insertion of an intergrowth layer in a matrix having a trigonal structure. The homogeneous and periodical structure of M-phase in LNT needed to sinter at 1393 K for 40 h-200 h using a conventional electric furnace. In order to form the homogeneous intergrowth layers rapidly, millimeter-wave or air-pressure control atmos furnaces were also used as smart processing techniques. We concluded that atomic diffusion was promoted in the useful reaction-fields: millimeter-wave radiation or high oxygen pressure.

Pulsed Dose Oxygen Delivery During Mechanical Ventilation: Impact on Oxygenation.

Adequate oxygenation is one of the primary goals of mechanical ventilation. Maintenance of adequate oxygenation and prevention of hypoxemia are the primary goals for the battlefield casualty, but military operations have unique concerns. In military operations, oxygen is a limited resource. A portable oxygen concentrator has the advantage of operating solely from electrical power and theoretically is a never-exhausting supply of oxygen. Our previous bench work demonstrated that the pulsed dose setting of the concentrator can be used in concert with the ventilator to maximize oxygen delivery. We evaluated this ventilator/concentrator system with closed loop control of oxygen output in a porcine model. The Zoll 731 portable ventilator and Sequal Saros portable oxygen concentrator were used for this study. The ventilator and concentrator were connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen based on the oxygen saturation (SpO2) via the integral pulse oximetry sensor. The ventilator communicates with the concentrator to increase or decrease oxygen bolus size to maintain a target SpO2 of 94%. Three separate experiments were conducted in this study. Experiments 1 and 2 used oxygen bolus sizes 16-96 mL in 16-mL increments and experiment 3 used 1 mL increments. The oxygen bolus was delivered from the concentrator and injected into the ventilator circuit at the patient connector. Six pigs were used for each experiment. Experiment 1, done without lung injury, was completed to determine the optimum timing during the respiratory cycle for injecting the oxygen bolus. Lung injury for experiments 2 and 3 was induced in the animals by warmed saline lavage via the endotracheal tube until PaO2/FIO2 decreased to <100. The pigs were then placed on the ventilator/concentrator system and allowed to adjust the oxygen autonomously to determine if the target SpO2 could be maintained. PEEP was manually adjusted. Arterial blood gases were drawn to verify the PaO2 and the SpO2/SaO2 correlation. Experiment 1 showed that the O2 bolus injected into the ventilator circuit 300 ms before breath delivery produced the highest PaO2. Mean PaO2/FIO2 was 500 ± 33 for experiments 2 and 3 before lung lavage and 72 ± 11 after lung lavage (p < 0.001), representing severe acute respiratory distress syndrome. Thirty minutes after placing the animals on the ventilator/concentrator system, the bolus size range was 64-96 mL and 16-96 mL after 2 hours (p < 0.05). The SpO2 range was 81-95% after 30 minutes and 94-98% after 2 hours (p < 0.05). PEEP range was 5-14 cm H2O. The SpO2 to SaO2 difference was ≤4% throughout the evaluation. The ventilator/concentrator system was able to manage oxygenation of severely injured lungs in a porcine model by injecting oxygen boluses at the front end of the ventilator breath, and appropriate use of PEEP to maximize oxygen delivery at the alveolar level. This proof of concept ventilator system may prove to be of use in situations where high-pressure oxygen is unavailable but electricity is accessible.

LA-ICP-MS Analysis of Clinopyroxenes in Basaltic Pyroclastic Rocks from the Xisha Islands, Northwestern South China Sea

Cenozoic volcanic rocks were recently discovered during full-coring kilometer-scale major scientific drilling in the Xisha Islands, northwestern South China Sea. A systematic mineralogical study of these samples was performed for this paper. The results show that the volcanic rock samples are basaltic pyroclastic. The major elements demonstrate that the clinopyroxenes are diopside and fassaite, which contain high Al2O3 (5.33–11.2 wt. %), TiO2 (2.13–4.78 wt. %) and CaO (22.5–23.7 wt. %). Clinopyroxenes have high REE abundances (104–215 ppm) and are strongly enriched in LREE (LREE/HREE = 3.56–5.14, La/YbN = 2.61–5.1). Large-ion lithophile elements show depleted characteristics. Nb/Ta shows obvious fractionation features: Nb is lightly enriched, relative to primitive mantle, but Ta is heavily depleted, relative to primitive mantle. The parental magma of the basaltic pyroclastic rocks belongs to a silica-undersaturated alkaline series, characterized by a high temperature, low pressure, and low oxygen fugacity. The AlIV content increases with decreasing Si concentration. The Si-unsaturated state causes Si-Al isomorphic replacement during the formation of clinopyroxene. The electric charge imbalance caused by the replacement of Si by Al is mainly compensated by Fe3+. The clinopyroxene discrimination diagrams show that the parental magma formed in an intraplate tectonic setting environment.

Ignition and Oxidation of Core–Shell Al/Al2O3 Nanoparticles in an Oxygen Atmosphere: Insights from Molecular Dynamics Simulation

This study employed the reactive force field molecular dynamics to capture atomic-level heat and mass transfer and reaction processes of an aluminum nanoparticle (ANP) oxidizing in a high temperature and pressure oxygen atmosphere, revealing detailed mechanisms for oxidation of ANPs. Temporal variations of temperature, density, mean square displacement, atom consumption rate, and heat release rate of ANPs have been systematically examined. In addition, the effects of environment on ANP oxidation were also evaluated. The results show that ANPs undergo four stages of preheating, melting, fast Al core, and moderate shell oxidations during the whole oxidation process. The Al core starts to melt from a core–shell interface with outward diffusion of core Al atoms into the shell. Intense reaction occurs between shell O and core Al atoms around the interface at the end of melting, leading to fast Al core oxidation. After complete oxidation of the Al core, the oxide shell continues to react with ambient O atoms. Both the initial environmental temperature and the equivalent pressure significantly influence the preheating. Conversely, the melting stage seems almost independent of any of them. However, fast Al core oxidation presents more sensitivity to the ambient equivalent pressure.

MORPHOLOGICAL AND MICROSTRUCTURAL CHARACTERISTICS OF HA COMPOSITE FILMS DEPOSITED BY PULSED LASER

The influence of oxygen atmosphere and substrate temperature on morphology and microstructure of the hydroxyapatite (HA) composite films prepared by pulsed laser deposition (PLD) was studied. According to the results of X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR), it was found that the phase compositions and the crystallinity of HA were affected by the oxygen pressure and substrate temperature. High oxygen pressure can increase the crystallinity of HA, and make random oriented HA gradually transform into [Formula: see text]-axis orientation, and decrease the Ca/P atomic ratio of the film. High substrate temperature can increase the crystallinity of films and the degree of c-axis orientation of HA, but increase the Ca/P atomic ratio slightly. Changes of oxygen pressure or substrate temperature have little influence on the surface morphology and thickness of film. Valuable HA composite film could be obtained at 600[Formula: see text]C under 5[Formula: see text]Pa O2atmosphere.

Residual high intrapulmonary shunt fraction limits exercise capacity in patients treated with balloon pulmonary angioplasty

Balloon pulmonary angioplasty (BPA) has emerged as a new treatment strategy for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Improvements in hemodynamic parameters after BPA have been reported, but some patients continue to suffer from reduced exercise tolerance even after the normalization of hemodynamic parameters following BPA. As the amelioration of hemodynamic parameters is reportedly achieved via BPA, we hypothesized that the limiting factors for exercise tolerance in these patients are related to respiratory function. Therefore, we investigated the associations between respiratory function and exercise tolerance, and the mechanisms underlying respiratory dysfunction in patients after BPA. We analyzed 62 patients with CTEPH who underwent 1-year follow-up after BPA. Predictors for reduced exercise tolerance after BPA determined with six-minute walk test were sought from pulmonary hemodynamic and respiratory parameters using logistic regression analysis. After multivariate adjustments, high mean right atrium pressure (mRAP) and high alveolar-arterial oxygen gradient (A-aDO2) were significant predictors for reduced exercise tolerance. Next, we analyzed factors associated with high A-aDO2. Among the pathophysiological causes of high A-aDO2, including ventilation, diffusing capacity, and low ventilation-perfusion ratio, only low ventilation-perfusion ratio caused by high intrapulmonary shunt fraction was associated with high A-aDO2. Impaired oxygenation due to residual high intrapulmonary shunt fraction was associated with reduced exercise tolerance in patients with CTEPH, after receiving BPA.

Optical Diagnostics in a High-Pressure Combustor with Gaseous Oxygen and Kerosene

This paper presents analysis of results from optical diagnostics in a high-pressure combustor burning gaseous oxygen (GOX) and liquid kerosene RP-2 fuel through a jet-swirl coflow injector. The objectives of the experiment were to measure flame stabilization and position under high-pressure conditions. Data were obtained at pressures from 2 to 16.5 MPa and mixture ratios from 2.9 to 20. High-speed cameras captured side-on chemiluminescence and infrared images of the flame. Results show that the flame-spreading angle from the injector ranges from approximately 3 to 6 deg, varying with pressure and propellant mass flow rate. A novel borescope was used to image the flame from upstream of the GOX post, enabling visualization of the flame near its stabilization location. The flame stabilization characteristics change significantly with the fuel flow velocity (which is proportional to pressure). At low pressures and fuel flow velocities, the flame appears to be distributed azimuthally in a nearly axisymmetric manner. At higher velocities, helical spirals of luminosity develop near the GOX post. In addition, the side-on views reveal concentrated streaks of, presumably, fuel entering the combustion chamber. These results suggest that computations must resolve the individual fuel injection orifices, to capture the flame stabilization.

Development of a flat membrane microchannel packed-bed reactor for scalable aerobic oxidation of benzyl alcohol in flow

A flat membrane microchannel reactor was designed and demonstrated for the safe and scalable oxidation of solvent-free benzyl alcohol with molecular oxygen on Au-Pd/TiO2 catalyst. The microchannel reactor employed a mesh-supported Teflon AF-2400 membrane, with gas and liquid channels on each side. Catalyst particles were packed in the liquid flow channel. Operation with 20 bara pressure difference between the gas and the liquid phases was possible at 120 °C. Pervaporation of organics through the membrane was experimentally measured to ensure that the organic vapour concentration remained below the lower flammability limit during the reaction. High oxygen pressure was shown to have a positive effect on reactor performance. A conversion of benzyl alcohol of 70% with 71% selectivity to benzaldehyde was obtained at 1150 gcat·s/galcohol, 8.4 bara oxygen pressure and 10 bara liquid pressure. The oxygen consumption rate was not significantly decreased when doubling the membrane thickness, indicating that the membrane generated only low resistance to oxygen mass transfer. When changing the catalyst particle size and the liquid flow rate, no significant effect was observed on the oxidation reaction rate. An effectiveness factor approach is proposed to assess the effect of oxygen permeation and transverse mass transfer on the catalyst packed in the membrane reactor, which suggests that the oxidation of benzyl alcohol on the highly active Au-Pd/TiO2 catalyst is controlled by the oxygen transverse mass transfer in the bulk liquid within the catalyst bed. Scale-up of the flat membrane microchannel reactor was demonstrated through increasing the liquid channel width by approximately ten times, which increased the reactor productivity by a factor of eight.

The Effects of Oxygen and Treatments in Hypoxic Conditions in SH-SY5Y Cells.

Many patients are admitted to the emergency department due to trauma. Patients with massive hemorrhage and respiratory failure can fall into hypovolemic shock. Thereafter, oxygen is an essential part of the treatment of trauma patients, but the mechanisms of its effects in the management of trauma patients remain unknown. Therefore, we conducted an experiment to apply hypoxia, hyperoxia, and other treatment with the goal of decreasing hypoxic neuronal cells damage, as reflected by cell survival, apoptosis, hydrogen peroxide (H2O2) production, and hypoxia-inducible factor 1α (HIF) expression in SH-SY5Y cells. Under hypoxic insults, cell survival percentages decreased and apoptosis was seen with increased necrotic cell death. High-pressure oxygen (80% O2) had no effect compared with normal-pressure oxygen (20% O2). After exposure to hypoxia, H2O2 production and levels of HIF significantly increased compared with normoxia. However, when pentoxifylline (PTX), steroid, and hypertonic saline (HTS) were added after exposure to hypoxic conditions, the production of H2O2 and HIF levels significantly decreased in the groups treated with PTX and HTS. That is, the neuroprotective effect of PTX and HTS alleviated the impacts of hypoxic insulted on neuronal cells.

Tuning LaAlO3 lattice structure by growth rate at the picometer scale in LaAlO3/SrTiO3 heterostructures

Here, we report an abnormal lattice reconstruction of LaAlO3 in the LaAlO3/SrTiO3 two-dimensional electron liquid heterostructure using the layer-by-layer pulsed laser deposition. We found that the lattice structure change of the top LaAlO3 layer is at the picometer level and is mainly controlled by the oxygen vacancies with an abnormal dependence on the oxygen background pressure. The lattice of the LaAlO3 film expands with more oxygen vacancies grown with high oxygen pressure and collapses with less oxygen vacancies grown with low oxygen pressure. The in situ monitoring of reflective high energy electron diffraction shows the lattice change coincident to the layer-by-layer deposition period change, revealing a non-equilibrium correlation between the lattice and the deposition environment, instead of the commonly assumed equilibrium correlation.

Iodine defect energies and equilibria in ZrO2

Incorporation energies and defect equilibria in monoclinic, tetragonal and cubic phases of ZrO2 are predicted, using density functional theory calculations, for iodine dopant concentrations between 10−5 and 10−3 atoms per formula unit of ZrO2. Data are presented for monoclinic and tetragonal polymorphs, in the form of Brouwer diagrams, to show the defect response at oxygen pressures ranging from 10−35 to 100 atm. The oxygen pressure required for stoichiometry in monoclinic ZrO2 is approximately 10−7.5 atm, at both low and high iodine concentrations, whereas for tetragonal ZrO2, it increases from 10−10 to 10−6.5 atm as the iodine concentration is increased from 10−5 to 10−3 atoms/formula unit. The dominant defects in monoclinic ZrO2 are IO• charge-compensated by I‴Zr at low oxygen pressures, and a combination of I‴Zr, IO••• and Ii• defects at high oxygen pressures. In tetragonal ZrO2, the dominant defects at low oxygen pressures are e′, VO•• and IO•. At high oxygen pressures, h• and I‴Zr are dominant, with additional charge-compensation from V″″Zr defects when iodine concentrations are low. The concentration of IO defects in the tetragonal phase decrease with increasing oxygen pressure above stoichiometry, demonstrating competition between iodine and oxygen for occupancy of the anion site. This has implications for fuel and cladding designs that are resistant to iodine-SCC.

Sample‐Controlled analysis under high pressure for accelerated process studies

AbstractThe potential of controlled rate thermal analysis (CRTA) for studying high‐pressure gas‐solid processes has been evaluated. CRTA is a type of smart temperature program based on a feedback system that uses any experimental signal related to the process evolution for commanding the temperature evolution. In this work, an instrument that uses the gravimetric signal for CRTA control has been designed and used for the study of two high‐pressure gas‐solid reactions: the highly exothermic thermal oxidation of TiC under high pressure of oxygen and the reduction in Fe2O3 under high pressure of hydrogen. Advantages of CRTA for discriminating overlapping processes and appraising kinetic reaction mechanisms are shown.

Polymer Electrolyte Membrane Fuel Cells (PEMFCs) Catalyst Layer Based on the Triple-Phase Separated Nanostructure

The eco-friendly power generation mechanism and high energy density of polymer electrolyte membrane fuel cells(PEMFCs) have been steadily researched in many institutions and countries that are aiming for sustainable development and have improved to a commercially available level of performance. However, electrode production using platinum has high price and supply problem, so research is being carried out to achieve high performance using small amount Pt catalyst. In order to produce MEA that meet these requirements, this study understands the three phase boundary, which is the basis of the catalytic reaction, and aims to design an electrode layer suitable for a polymer electrolyte membrane fuel cell and suggest a production method. In the conventional electrode manufacturing process, the mixed liquid slurry is used, so the ionomer is randomly distributed in the electrode layer after drying. Therefore, it was difficult to adjust to exist in the optimal position favorable to the reaction. Especially, the thick ionomer on carbon supports is located in the catalyst layer inevitably has a structure that is difficult to reach the Pt surface because the reaction gas supplied through the pores is diffused. In the case of cathodes, Pt surface is known to form a low oxygen fraction of 1/20 compared to pores, which indicates the limit of performance with high mass transfer resistance. In this study, Ionomer was coated on a carbon support and then solidified. After that, the electrode was made by mixing with the commercial catalyst at the optimal ratio, so that the movement path of the proton and the electron could be separated independently. We are trying to suggest a new recipe to make a catalytic layer that can induce high oxygen pressure on the surface of the catalyst and introduce a pore distribution that is effective for electrochemical reactions. In addition, the catalytic layer produced by this method was able to realize an independent path because the contact of each part was maintained well. As a result, the pores effective for electrochemical reactions were widened to achieve the performance of commercial electrodes even at a low level of 0.2mgPt/cm2. Moreover, this method can be used to produce high-performance electrodes at a low price using a small amount of expensive platinum catalysts, and especially in the related industries, because all materials used in the manufacturing method are commercially used and do not require specially manufactured equipment.

Electrically Controlled Nano and Micro Actuation in Memristive Switching Devices with On-Chip Gas Encapsulation.

Nanoactuators are a key component for developing nanomachinery. Here, an electrically driven device yielding actuation stresses exceeding 1 MPa withintegrated optical readout is demonstrated. 10 nm thick Al2 O3 electrolyte films are sandwiched between graphene and Au electrodes. These allow reversible room-temperature solid-state redox reactions, producing Al metal and O2 gas in a memristive-type switching device. The resulting high-pressure oxygen micro-fuel reservoirs are encapsulated under the graphene, swelling to heights of up to 1 µm, which can be dynamically tracked by plasmonic rulers. Unlike standard memristors where the memristive redox reaction occurs in single or few conductive filaments, the mechanical deformation forces the creation of new filaments over the whole area of the inflated film. The resulting on-off resistance ratios reach 108 in some cycles. The synchronization of nanoactuation and memristive switching in these devices is compatible with large-scale fabrication and has potential for precise and electrically monitored actuation technology.

Fluid evolution and mineralization mechanism of the East Kounrad porphyry Mo-W deposit in the Balkhash metallogenic belt, Central Kazakhstan

The East Kounrad Mo-W deposit is located in the eastern part of the Balkhash metallogenic belt, Central Kazakhstan. The intrusion in the East Kounrad deposit is a Permain complex that includes medium- and fine-grained granites. Both the primary magma and hydrothermal fluids of the East Kounrad deposit are characterized by high fluorine and high oxygen fugacity, which would be important for the formation of high-grade large Mo deposit. Four mineralization stages are identified in this study. Stage I quartz–wolframite ± molybdenite ± fluorite veins, which were associated with intensively greisen alteration, were formed from fluids with high temperature (340–460 °C), high pressure (250–400 bars), high/low salinity (54.5 wt% and 3.4–10.2 wt%, respectively), and high oxygen fugacity with a fluid system of H2O-NaCl-CO2. Stage II quartz–molybdenite ± pyrite veins, which were accompanied by K-feldspars–muscovite–fluorite alteration, were formed from fluids with medium-high temperature (260–400 °C), medium pressure (100–250 bars), high/low salinity (39.1–58.4 wt% and 2.4–11.7 wt%, respectively), and relatively low oxygen fugacity. After the main stage of W and Mo mineralization, stage III quartz–pyrite ± molybdenite veins, associated with quartz–sericite alteration, were formed from fluids with medium-low temperature (160–340 °C), low pressure (less than 100 bars), various salinity (4.5–46.2 wt%) and high oxygen fugacity. Stage IV quartz–polymetallic sulfide veins, related to argillic alteration, were formed under temperature of 120–220 °C and salinity of 1.7–8.1 wt%. Remarkably, fluid boiling is the most important precipitation mechanism of molybdenite and wolframite. In addition, the decreasing oxygen fugacity and temperature also play a vital role in triggering deposition of molybdenite. The Pb isotopic composition of sulfides shows that the ore-forming materials at East Kounrad are dominantly derived from the lower crust.

High Oxygen Pressure during Continuous Hypothermic Machine Perfusion is Associated with a Better Ex Vivo Renal Blood Flow and Early Graft Function in a Porcine DCD Auto-Transplant Model

High Oxygen Pressure during Continuous Hypothermic Machine Perfusion is Associated with a Better Ex Vivo Renal Blood Flow and Early Graft Function in a Porcine DCD Auto-Transplant Model