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ABS TRACT Synthetic gases attract the attention of researchers due to the increase in energy demand. H2 and CO gases are the main components of synthetic gases. In this study, three different gas mixtures were tested according to their H2/CO (3, 1.5, 0.5) ratios. Thermal power (3 kW), swirl number (1) and equivalence ratio (0.7) kept constants for all experiments. Three different oxygen ratios selected for the oxygen enrichment experiments. First, the gas mixture was burned with standard air. After that, the oxygen concentration in the oxidizer was raised to 23 % and 25 % for examining the effect of oxygen enrichment. The stability results showed that an increase of hydrogen content in the synthetic gas mixtures caused decreasing in the oxygen enrichment limit. The mixture, which can be enriched up to 25.8 % O2 while the H2/CO ratios are 0.5, can be increased up to 25.2 % O2 at a medium H2/ CO ratio (1.5). In the case where the H2/CO ratio was increased to the high level (3) by increasing the hydrogen level, the oxygen enrichment limit decreased to 24.1 %. A stable flame did not occur after these oxygen enrichment values. In addition, dynamic pressure data were recorded for all mixtures under external acoustic enforcement. Increases in the hydrogen and oxygen ratio at the same time caused the flame instabilities. Thus, the flame extinguished under acoustic enforcement. In addition to these results mentioned, the emission values showed that oxygen enrichment caused the decrease in CO emissions but the increase of NOx values for all synthetic gas mixtures.(c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

12 pages, 3 figures, 2 tables, supporting information https://doi.org/10.1002/lno.11981.-- Data Availability Statement: The raw sequence data that support the findings in this study have been deposited online and can be accessed at the NCBI BioProject PRJNA531756, Human-induced expansion of oxygen-deficient zones can have dramatic impacts on marine systems and its resident biota. One example is the formation of the potent neurotoxic methylmercury (MeHg) that is mediated by microbial methylation of inorganic divalent Hg (HgII) under oxygen-deficient conditions. A negative consequence of the expansion of oxygen-deficient zones could be an increase in MeHg production due to shifts in microbial communities in favor of microorganisms methylating Hg. There is, however, limited knowledge about Hg-methylating microbes, i.e., those carrying hgc genes critical for mediating the process, from marine sediments. Here, we aim to study the presence of hgc genes and transcripts in metagenomes and metatranscriptomes from four surface sediments with contrasting concentrations of oxygen and sulfide in the Baltic Sea. We show that potential Hg methylators differed among sediments depending on redox conditions. Sediments with an oxygenated surface featured hgc-like genes and transcripts predominantly associated with uncultured Desulfobacterota (OalgD group) and Desulfobacterales (including Desulfobacula sp.) while sediments with a hypoxic-anoxic surface included hgc-carrying Verrucomicrobia, unclassified Desulfobacterales, Desulfatiglandales, and uncharacterized microbes. Our data suggest that the expansion of oxygen-deficient zones in marine systems may lead to a compositional change of Hg-methylating microbial groups in the sediments, where Hg methylators whose metabolism and biology have not yet been characterized will be promoted and expand, This work was funded by the Swedish Research Council Formas (grants 2018-01031 and 2016-00804); the Swedish Research Council (grants 2015-03717 and 2017-04422); the Swedish Environmental Protection Agency (grant NV-802-0151-18). A.G.B. acknowledges the Marie Curie Individual Fellowship (H2020-MSCA-IF-2016; project-749645). The authors acknowledge support from the National Genomics Infrastructure in Stockholm funded by Science for Life Laboratory, the Knut and Alice Wallenberg Foundation and the Swedish Research Council; SNIC/Uppsala Multidisciplinary Center for Advanced Computational Science for assistance with massively parallel sequencing and access to the UPPMAX computational infrastructure. The bioinformatic analyses were enabled by resources in project SNIC 2018-8-246 provided by the Swedish National Infrastructure for Computing (SNIC) at UPPMAX, partially funded by the Swedish Research Council through grant agreement no. 2018-05973, With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

The exploration for low-cost bifunctional materials for highly efficient overall water splitting has drawn profound research attention. Here, we present a facile preparation of Mo–P dual-doped Co/o...

The modern Pacific Ocean hosts the largest oxygen-deficient zones (ODZs), where oxygen concentrations are so low that nitrate is used to respire organic matter. The history of the ODZs may offer key insights into ocean deoxygenation under future global warming. In a 12-My record from the southeastern Pacific, we observe a >10‰ increase in foraminifera-bound nitrogen isotopes (15N/14N) since the late Miocene (8 to 9 Mya), indicating large ODZs expansion. Coinciding with this change, we find a major increase in the nutrient content of the ocean, reconstructed from phosphorus and iron measurements of hydrothermal sediments at the same site. Whereas global warming studies cast seawater oxygen concentrations as mainly dependent on climate and ocean circulation, our findings indicate that modern ODZs are underpinned by historically high concentrations of seawater phosphate., Proceedings of the National Academy of Sciences of the United States of America, 119 (45), ISSN:0027-8424, ISSN:1091-6490

Subject and Purpose. Peculiarities are considered of a purposeful modification of the functional indices of wheat seeds upon their soaking in water preliminarily enriched with oxygen and simultaneously irradiated with a low-intensity electromagnetic field (EMF). The aim is to investigate effectiveness of such an indirect exposure of wheat seeds to a low-intensity electromagnetic field related to discrete bands in the extremely high-frequency (EHF) range and depending on the initial state of seeds, “norm” or “pathology”. Methods and methodology. The study comprises experimentally approved radio-physical, radio-engineering and chemical methods. Generators G4-141 (37.5…53.57 GHz) and G4-142 (53.57…78.33 GHz) serve as radiation sources. Oxygen is obtained by reacting a hydrogen peroxide solution with potassium permanganate. The oxygen enrichment of water is executed during its irradiation. The verification of indirect electromagnetic field exposure is based on changes demonstrated by such functional indices of seeds as germination energy and mean lengths of roots and seedlings in each sample. Results. A possibility has been established to modify the functional indices of wheat seeds through their soaking in water preliminarily irradiated with an EMF and simultaneously enriched with oxygen. It has been revealed that the efficiency of the effect depends on whether the seeds are in “normal” or “pathological” state and that a feasibility exists of recovering properties lost in a “pathology” state. The role that the oxygen in the water imbibing the seeds plays in the germination process has been demonstrated. Peculiarities as to the efficiency of wheat seed EMF exposure through the oxygen-enriched water have been shown depending on the signal frequency and length of exposure and on the total energy load. Conclusion. It has been found that substances, including living entities, can be electromagnetically exposed through water. The water-dissipative model of substance exposure to the electromagnetic field has been validated. In this model, water is one of the targets liable to changing its properties at the EMF exposure. This point has been indirectly confirmed by the studies of the states of seeds upon their soaking in the pre-irradiated water. The gas model of the EMF interaction with a substance has been verified, too. A possibility of oxygen activation at resonance irradiation has been shown.

Oxy-combustion and oxygen enriched combustion are considered as promising options for CO2 capture and storage. In the present study, numerical simulations of a 30 kWth circulating fluidized bed reactor were performed under oxygen enriched (O2/N2) and oxy-combustion (O2/Recycled Flue Gas) (RFG) conditions to investigate the effects of combustion atmospheres on the lignite combustion characteristics. The influence of oxygen concentration ranging from 21% to 28% on temperature and gaseous emissions were investigated by keeping excess oxygen ratio constant at 1.45 for both atmospheres. The predicted gas emissions and temperature profiles along the combustor were validated with conducted experiments. A good agreement between the simulated and measured data was achieved. CO2 emission was found more in O2/RFG combustion compared to O2/N2 mode. All gas emissions increased with oxygen enrichment except for CO in both cases. O2/RFG case appears to be more promising option considering emission amounts per unit energy input.

Oxygen-enriched and deep-staging (OE and DS) combustion has drawn increasing attention due to its superior nitrogen oxide reduction efficiency and combustion efficiency. To clarify the NOx generati...

Engineering an efficient interface is a trustworthy strategy for designing advanced photocatalytic systems for solar energy conversion. Herein, oxygen-deficient Bi2WO6 atomic layers without organic residues were successfully fabricated via a facile solvothermal strategy by the multifunctional regulatory mechanism of introduced chloridion. Both DFT calculations and speciation determination revealed that chloridion displayed a more pronounced effect in the controllable synthesis of oxygen-deficient Bi2WO6 atomic layers without organic residues: ultrathinning and defect-engineering. This built-in multi-cooperative interface endowed Bi2WO6 with intriguing photoelectrochemical properties, O2 activation ability, and ultrahigh activity in visible-light powered deep oxidation of NO. A reasonable photocatalytic mechanism was proposed based on in situ infrared spectroscopy analysis and theoretical calculations. We believe that this multi-cooperative interface engineering of oxygen-deficient Bi2WO6 atomic layers without organic residues could provide new insights into the design of two-dimensional (2D) layered materials with efficient active sites and pave the way for efficient NO photooxidation systems.

A novel high-swirl reactor ANJEVOC-CP (annular jet vortex chamber for combustion pyrolysis) was designed for producing high-value chemicals such as alkynes and olefins from natural gas. In such a s...

Diffuse oxygen supply is an important means to improve the indoor oxygen environment of buildings and ensure physiological and psychological health of immigrants in plateau areas. Existing research on oxygen enrichment strategies at high altitudes has mainly focused on confined spaces under mechanical ventilation, with few studies on the distribution of indoor oxygen concentration under natural ventilation in actual buildings. This study used a verified computational fluid dynamics (CFD) method to investigate the indoor oxygen distribution with practical consideration of natural ventilation at high altitudes. The results showed that the oxygen distribution under wind-driven natural ventilation was more nonuniform than that under buoyancy-driven natural ventilation, with the ratio of local oxygen concentration to overall-mean oxygen concentration, the k value, between 0.8 and 1.3 under wind-driven natural ventilation and between 0.9 and 1.1 under buoyancy-driven natural ventilation. The effects of meteorological condition and oxygen source position on indoor spatial oxygen distribution characteristics were explored with careful examination in human occupied zone under lying, sitting and standing postures. The results can provide implications for effective and energy saving design of indoor oxygen supply system in plateau buildings.

Objectives Large drops in blood oxygen saturation (SpO2) to levels as low as 84% was observed following Tai Chi practice, during a study on the effects of Tai Chi on SpO2. The objectives of the current pilot study were to determine if this was a statistically significant drop, and how SpO2 levels compared to an aerobic activity such as running, in pre, concurrent, and post measurements. Methods Repeated measures of blood oxygen saturation (SpO2) were taken of a 50-year-old male before, during and for 1 min after TC and running. Results Measurements of SpO2 before, during, and after TC resulted in a statistically significant increase in SpO2 during TC (p=1.69e-06), and a statistically significant (p=1.71e-06) brief momentary drop from resting levels, as low as 87% SpO2. Running showed no significant change in pre and post levels, with a significant change and decrease in SpO2 during running (p=1.1e-08), suggesting increased oxygen use by the large muscle groups during exercise. SpO2 returned to normal resting levels following running with no post drop. Results suggest a higher rate of oxygen metabolism during TC, with a potential effect on hypoxic (oxygen deficient) areas of the body. Conclusions Findings suggest direct and unique effects on enhanced blood oxygen saturation and oxygen metabolism, which may underlie benefits for conditions complicated by hypoxia, including cardiopulmonary disease, immunity, chronic pain, and arthritis.

Cobalt sulfide is favorable for supercapacitors, but its application is inhibited by the inherent slow charge transfer kinetics and poor stability in alkaline solution. Herein, zeolitic imidazole f...

Materials having an anisotropic crystal structure often exhibit anisotropy in the electrical conductivity. Compared to complex transition-metal oxides (TMOs), simple TMOs rarely show large anisotropic electrical conductivity due to their simple crystal structure. Here, we focus on the anisotropy in the electrical conductivity of a simple TMO, oxygen-deficient tungsten oxide (WOx) with an anisotropic crystal structure. We fabricated several WOx films by the pulsed laser deposition technique on the lattice-matched (110)-oriented LaAlO3 substrate under a controlled oxygen atmosphere. The crystallographic analyses of the WOx films revealed that highly dense atomic defect tunnels were aligned one-dimensionally (1D) along [001] LaAlO3. The electrical conductivity along the 1D atomic defect tunnels was similar to 5 times larger than that across the tunnels. The present approach, introduction of 1D atomic defect tunnels, might be useful to design simple TMOs exhibiting anisotropic electrical conductivity.

Oxygen-deficient/non-stoichiometric tungsten oxides are a distinct class between two only stoichiometric tungsten oxides, i.e., WO3 and WO2. The WO3 could be termed as a parent structure while understanding the non-stoichiometric tungsten oxides. The oxygen vacancies (Ovacs) induced in the parent (WO3) structures cause the re-adjustment of atomic arrangement to compensate for the oxygen deficiency and follow the crystal chemistry. The degree of Ovacs determines the range of WO3-x. The W18O49 (WO2.722) is the highest oxygen-deficient stable phase. These non-stoichiometric oxides proved superior to WO3 for various applications. Thus, the composition, chemistry, crystallography, synthesis, and formation mechanisms of such materials have been elaborated. Further, the superiority of the materials in view of few applications is well discussed. Finally, the importance of non-stoichiometry/Ovacs in metal oxides for various functional applications can be understood.

The rapid proliferation of tumor cells and tortuous vasculature in solid tumors often bring about a hypoxic tumor microenvironment, which renders tumor cells more resistant to many cancer treatments, including radiotherapy. In this study, an injectable and thermosensitive composite hydrogel composed of perfluorooctanoic acid (PFOA) modified monomethoxy poly(ethylene glycol)-poly(D,L-lactide-co-glycolide) (mPEG-PLGA-PFOA) and perfluorooctyl bromide (PFOB) that presented a thermoreversible sol-gel transition upon heating was developed to deliver exogenous oxygen for the relief of tumor hypoxia and enhancement of radiotherapy. The fluorinated modification of copolymers significantly increased the stability of PFOB in the mPEG-PLGA-PFOA aqueous solution owing to the fluorophilic interaction between PFOB and PFOA-modified copolymers. The introduction of PFOB not only efficiently heightened the oxygen loading capacity of the composite hydrogel, but also endowed it with excellent X-ray opacity, allowing the visual observation of the hydrogel via micro-CT imaging. After peritumoral injection of the oxygen-enriched composite hydrogel, the continuous supply of oxygen effectively relieved tumor hypoxia and down-regulated the expression of hypoxia-inducible factor-1α. Profiting from this, the hyposensitivity of tumor cells to radiation was successfully reversed, and the tumor growth in mice was significantly suppressed and the survival of mice was prolonged when combined with multiple X-ray exposure. As a result, the oxygen-enriched composite hydrogel shows a great potential for radiosensitization to improve the radiotherapeutic efficacy.

In this report, SrFeO3-δ nanoparticle perovskite sample was prepared by the co-precipitation method. Rietveld refinement of the X-ray diffraction (XRD) data of SrFeO3-δ sample showed that it has a ...

Human life on Earth depends on the continuous availability of oxygen, but conditions for the entry of oxygen into the cells of the body change in time and space, easily broken, owing to what may develop hypoxia - a condition of oxygen starvation of tissues. The first part of the review provides information on the maintenance of oxygen homeostasis in cells, on the key component responsible for the regulation of the molecular response to hypoxia - the HIFs family of transcription factors (Hypoxia-Inducible Factors). It is indicated that it is possible to compensate for the lack of oxygen in the body by delivering it to cells and tissues with water and various oxygen cocktails. Data from experimental studies of the biological effect of oxygenated drinking water, as well as the results of studying the effects of oxygen-enriched drinking water with the participation of volunteers are presented. The issue of the formation of oxygen (free) radicals when drinking oxygen-enriched drinking water is considered. The second part of the review will provide data on the successful use of oxygen-rich water in domestic therapeutic and surgical practice in complex treatment in order to reduce the negative effect of hypoxia in patients with chronic heart failure and generalized peritonitis complicated by intestinal insufficiency syndrome; on the method of improving the supply of oxygen to the body using enteral oxygen therapy - oxygen cocktails - for diseases of the heart, lungs, bronchi and gastrointestinal tract, atopic dermatitis, placental insufficiency, as well as to improve physical and mental performance. The review draws specialist’s attention to the problem of the biological effect of oxygen-enriched drinking water, its insufficient knowledge and the possible yet unrealized potential in terms of preventing various diseases and maintaining optimal human health.

The experimental study on the laminar flame speeds of the CH4/H2/CO/CO2/N2 mixture was carried out in oxygen-enriched air condition. The laminar flame propagation velocities of the blended gas were measured in a range of equivalence ratios (from 0.6 to 1.4) and oxygen concentrations (from 21 to 33%) using a Bunsen flame. Comparisons between the experiments and calculations show that the GRI Mech 3.0 mechanism can well predict the laminar flame speed of the blended gas in oxygen-enriched conditions. The laminar flame propagation velocities were enhanced by the increasing oxygen concentration, while the reaction pathway of fuel changed little. The effects of each species of the CH4/H2/CO/CO2/N2 mixture on the laminar flame speeds were discussed. Results show that the laminar flame speed is promoted by the increase of H2 and CO, while the laminar flame speed is decreased by the increasing CH4, CO2, and N2 concentrations. The inhibition effect of CO2 on the laminar flame speed is bigger than that of N2, which is due to the difference in the properties of CO2 and N2.

In recent years, ammonia attracts much attention from researchers as a carbon-free energy carrier, but low reactivity hinders the direct use of ammonia in combustion applications. In this study, se...

Alkaline-earth perovskites are of particular interest for high-temperature energy conversion processes because of their mixed-valence charge states, which significantly affect their chemical and th...

Tin dioxide (SnO2) nanostructures are potential, excellent candidates for pseudocapacitive electrodes. However, the performances are seriously limited by their low electrical conductivities. Here, ...

Postoperative local recurrence and metastasis are non-negligible challenges in clinical cancer treatment. Photodynamic therapy (PDT) has presented a great potential in preventing cancer recurrence owing to its noninvasiveness and high specificity for local irradiation of tumor sites. However, the application of conventional PDT is often limited by insufficient oxygen supply, making it difficult to achieve high PDT efficacy. Herein, we combined liposomes with photosensitizer indocyanine green (ICG) and perfluorooctyl bromide (PFOB) to develop a new oxygen-enriched photodynamic nanospray (Lip-PFOB-ICG) for cancer postoperative treatment. The Lip-PFOB-ICG not only has good biocompatibility but also enhanced the PDT effect under near-infrared light. More importantly, PFOB can continuously absorb oxygen, thus improving the collision energy transfer between the ICG photosensitizer and oxygen, and significantly inhibit local tumor recurrence in the subcutaneous tumor recurrence model. This oxygen-enriched photodynamic nanospray strategy may open up new avenues for effective postoperative cancer therapy in the clinic.