Search

A crucial device with increasing demand is ventilator for patients who need help with breathing due to respiratory problem. In some cases there is a huge scarcity for oxygen cylinder especially in the emergency situation for this issues we creating a smart ventilator using the ESP32 microcontroller in which it will minimise the impact of ventilator shortage. It will be also a portable (easy to carry). Here we are making a low cost ventilator with self-pumping of the oxygen from the environmental air, with the help of AMBU bag. The components which we have used here are, Temperature sensor, BVM mask, buzzer, 20v transformer, converter, relay, dc motor. So the outcome of our project is a self-pumping of an oxygen through a ventilator without a human intervention. [ABSTRACT FROM AUTHOR]

A highly reactive and deadly material, atomic oxygen is prepared to undergo a singlet state transition (1O2). Commonly used in cancer diagnostics and photodynamic therapies, singlet oxygen (1O2) is produced by photoexcitation of compounds known as photosensitizers. Setting up the Singlet oxygen 1O2 is not a simple operation. For certain light-sensitive mixes, it is often undesirable. For instance, it makes the picture become white when tested with fluorescent light. Finding out how much singlet oxygen 1O2 is generated during light excitation is necessary to enhance the development of novel photosensitive synthetic compounds and treatments. The most direct way to measure the concentration of singlet oxygen 1O2 is to record its luminescence at 1270 nm. We advise utilising very specialised single-photon detectors since this fluorescence won't go away for long. Consequently, modern devices tend to be both costly and complicated. Using a simple piece of hardware and a very inexpensive NIR PIN photodiode, we provide a technique and solution for measuring the Singlet oxygen 1O2 luminescence in this work. Natural solvents including ethanol, DMSO, and H2O2 with NaOCl may be used to conduct estimates in a fixed mode. This basic setup is useful for evaluating the efficiency of singlet oxygen 1O2, which in turn helps with the development and presentation of photosensitizers and other photosensitive synthetic compounds. [ABSTRACT FROM AUTHOR]

The study's aim was to develop a simple and accurate oxygen saturation monitor that could be used for a variety of cardio exercises. The designed cuffless device was compared to a lab-based device (Pulse Oximeter) For two cardio regimes (skipping and walking). The lab-based system (Pulse Oximeter) was compared to the built cuffless device for skipping and waking data of normal subjects. The mean oxygen saturation was found to be very similar with a minor deviation between Lab based data for skipping and cuff-less data skipping (one way ANOVA (P>0.05), insignificant). As a consequence, the study concludes that the designed cuff-less wearable with the MAX30100 SpO₂ sensor seems to be equally efficient oxygen saturation monitor as any Lab-based pulse oximeter monitoring device. [ABSTRACT FROM AUTHOR]

Examples of high informativeness of generalized indicators in rapid water quality screening of technogenic organic carbon (TOC), technogenic organic chlorine (TOCl), technogenic organic bromine (TOBr), technogenic organic oxygen (TOO) are given. They reflect the total content of elements carbon, chlorine, bromine, oxygen in molecules of limited volatile organic compounds (LVOC). LVOC include compounds with boiling points in the range of 150-500° C and mol. mass up to 550 a.m.u. When using the proposed indicators, it is possible to timely fix LVOC in water source water at the stages of water treatment, the efficiency of water purification from LVOC during the passage of water filtering layers of wells at infiltration water intakes, the efficiency of filters and water purification devices for domestic and industrial use. [ABSTRACT FROM AUTHOR]

The aim of this article is to analytically examine the specific physical characteristics of high-temperature ceramic solid oxide superionic conductors, using the case study of an oxygen pump crafted from stabilized zirconium dioxide. By scrutinizing the basic axial cross-section of the superionic tube, considering geometric parameters like length, thickness, and tube diameter, an equation has been derived. This equation establishes a connection among all controllable variables of the oxygen pump across the entire range of oxygen dosage. It aids in selecting the device's geometric dimensions and optimal ratios for controllable parameters. The derivation of this equation for the pumping section of an oxygen pump is based on several assumptions, akin to those for an idealized oxygen pump. The volt-ampere characteristic of the oxygen pump is explored in the realm of deep pumping, linked to the emergence of electronic conductivity in the ceramics of the pumping section. This phenomenon may lead to the pump's destruction, electrochemical aging, or degradation. It is asserted that the volt-ampere characteristic is the sole informative curve for assessing the proper operation mode of the superionic pump and preventing the onset of electrochemical degradation. When formulating a research method and defining tasks for a ceramic oxide superionic conductor, several assumptions were considered, mirroring those for an idealized electrolyte. The examined solid oxide superionic conductor or solid electrolyte is a ceramic material shaped as tubes, test tubes, or tablets. These initially contain impurity cations of lower valence, such as calcium, yttrium, and scandium, in comparison to zirconium. These impurity cations are responsible for the presence of vacancies or holes in the solid cubic structure of zirconium dioxide. Through these vacancies, only oxygen anions are transported under the influence of external factors, high temperature, and a direct current electric field. The research methodology relies on measuring the electromotive force recorded at the air/electrode/superionic boundary section, which is mathematically linked to the oxygen concentration in the air stream. Mathematical formulas are provided for calculating the desired oxygen concentration based on various external conditions. Theoretical conclusions and justifications regarding the potential utilization of phenomenological transport properties of a superionic conductor in production conditions are presented. [ABSTRACT FROM AUTHOR]

A series of 6H-6-oxoanthra[1,9-cd]isoxazoles that contain various substituents at positions 3, 5, 7, etc. was obtained. We have found that arylotropic isomerizations of 5-aryloxynaphtho[1,2,3-cd]indole-6(2H)-ones occur under deaerated solutions and lead to 6-aryloxynaphtho[1,2,3-cd]indole-5(2H)-ones. The bathochromic shift of the resulting compounds is ∼100 nm. The initial 5-aryloxynaphtho[1,2,3-cd]indole-6(2H)-ones are destroyed by irradiation in the presence of oxygen. The resulting 6-aryloxynaphtho[1,2,3-cd]indole-5(2H)-ones are characterized by increased stability due obviously to the electron-donating effect of the π-excess pyrrole cycle on the aryloxyenone fragment. Interestingly, the initial 5-aryloxynaphtho[1,2,3-cd]indole-6(2H)-ones and 6-aryloxynaphtho[1,2,3-cd]indole-5(2H)-ones have the fluorescent properties. [ABSTRACT FROM AUTHOR]

Due to the various waves of the pandemic, which have affected millions of people both directly and indirectly, the past two years have been catastrophic on a global scale in terms of the loss of human life. The pandemic created a significant risk to human life and, in the process, revealed the fragility of the medical infrastructure with regard to the availability of medical devices, in particular the accessibility of oxygen concentrators. The oxygen concentrator was thrust into the spotlight as a result of the problem of overcrowded hospitals. Within the scope of this current body of work, a minimum viable product (MVP) of a portable and hospital-based oxygen concentrator has been developed. The PSA (Pressure Swing Adsorption) technology was used as the foundation for the design. After conducting tests here at the lab, further examinations were carried out at the government hospital. Both the 5 LPM version and the 15 LPM version were developed in order to carry out standard tests on adults at the Heart Institute for a period of eight to ten hours nonstop on a daily basis. The tests were carried out at the children's ward. During the course of the investigations, it was discovered that the apparatus has an increased ability to withhold heat as well as an increased purity concentration of 85–90%. According to the most recent test results, which were verified by the physicians and adhered to the recommendations of the World Health Organization, this effort has been effective. Additionally, the Sustainable Development Goal (SDGS-3) can be met by implementing this initiative. [ABSTRACT FROM AUTHOR]

Non-Faradaic electrochemical modification of catalytic activity (NEMCA) with an electric field (EF) has attracted attention as one of the methods to improve catalyst performance. However, this activation mechanism is not still clear. In this study, we focused on the NEMCA mechanism in CO2 methanation on Ni metal catalyst with solid oxide electrolysis cell (SOEC) and calculated two possible effects of the NEMCA mechanism; direct EF applications and oxygen atom co-adsorptions, using the density functional theory calculations and detailed kinetic simulations. Compared with these effects in terms of kinetic energy changes in the rate-determining steps, it has been revealed that the spillover effect of lattice oxygen toward the catalyst surface is dominant in the NEMCA mechanism. Also, we have found that overall CO2 methanation is promoted in SOEC mode with oxygen atom co-adsorptions in both cases of Ni flat and step sites. [ABSTRACT FROM AUTHOR]

We study the influence of vibrational and chemical relaxation behind the incident shock wave on the gas parameters behind the reflected wave. The detailed state-to-state approach is used to simulate the shock tube experiment for the pure oxygen flow. We extend our previous work including comparison with experimentally measured pressure time-histories behind the re-flected shock wave. The vibrational temperature time-histories are compared with both experimental and theoretical data obtained recently using simulations based on quasiclassical trajectory (QCT) method. The results show a weak role of dissociation reactions and, on the contrary, a significant effect of vibrational relaxation in the region between the incident and reflected shock waves on the pressure and temperature profiles. The best agreement with the experimental vibrational temperature is obtained for the combination of the Schwartz–Slawsky–Herzfeld (SSH) model of vibrational energy transitions and the state-specific Marrone–Treanor dissociation model with the parameter U = 3T. Three different definitions of the vibrational temperature are assessed, and their equivalence is proved. For more accurate comparison with experimental data we propose an additional correction to the experimental error which takes into account the effect of vibrational relaxation between the incident and reflected shocks. This correction is found large near the reflected shock front but tends to zero with rising distance. [ABSTRACT FROM AUTHOR]

A residual atmosphere of the Very-Low-Earth-Orbit (VLEO) could be the source of drag force. The Atmosphere-Breathing Electric Propulsion (ABEP) system has been proposed to compensate the drag force using the residual atmosphere as a propellant. The ABEP requires an intake device that collects atmosphere particles and delivers them to the discharge chamber. In this study, design parameters such as geometry, gas-surface interaction (GSI) models, surface temperature, and aspect ratio are to examine the performance of the intake device at the VLEO. The diffuse GSI model is considered to be realistic due to the adsorption of atomic oxygen. The results show that the geometry does not significantly affect the intake performance with the diffuse GSI model. Also, the lower surface temperature could increase the compression ratio while capture efficiency stays similar when the diffuse GSI model is used. The best performance is found at 15° out of 15 different tapered angles. [ABSTRACT FROM AUTHOR]

Very-Low-Earth-Orbit (VLEO) satellite requires a propulsion system for drag-compensating maneuvers to extend the mission lifetime. Electric propulsion (EP) systems have been widely adopted for orbit maintenance in recent decades. Even though the EP system shows high propellant efficiency, the mission lifetime is always limited by the onboard propellant capacity. Lately, an Atmosphere-Breathing Electric Propulsion (ABEP) system has been conceptually suggested to overcome the limitation by intaking ambient air as an alternative propellant. The ABEP and EP systems have similar ionization and acceleration mechanisms with different chemical compositions. In the plume of EP, plasma collisions may cause an ion backflow phenomenon. The backflow of ions is known to contaminate the satellite payloads and optical equipment. The backflowing ion current increases due to the plume-atmospheric gas interaction at VLEO. Moreover, the ion backflow of the ABEP system might be more contaminative on account of atomic oxygen. This study performs a 2D axisymmetric particle simulation to investigate such effects on the ABEP plume with Particle-In-Cell (PIC) and Direct Simulation Monte Carlo (DSMC) hybrid method. Collisions between ions and atoms are considered in 2 types; momentum exchange (MEX) collision and charge exchange (CEX) collision. The exhaust flow condition of ABEP is hypothetically analyzed. Far-field distribution of plume plasma properties is investigated. [ABSTRACT FROM AUTHOR]

According to the 2006 research report data of the Lembaga Penerbangan dan Antariksa Nasional (LAPAN) and the findings of the Balai Besar Teknologi Kesehatan Lingkungan dan Pengendalian Penyakit (BBTKLPP), the oxygen (O2) and carbon dioxide (CO2) levels on Gili Iyang Island reached 20.9%–21.5% and 302 ppm – 313 ppm, respectively. In comparison to oxygen levels in other regions, O2 concentrations are relatively higher. This investigation determined the air quality on Gili Iyang Island by an examination. Using O2 and CO2 meters, O2 and CO2 concentrations were measured at 77 sites over the island's land and water. The average O2 concentration is 20.02%, whereas the average CO2 concentration is 475.68 ppm. The measured findings suggest a reduction in O2 concentration and an increase in CO2 concentration. Based on the results of the visualization using the 3D field with the color cell map approach, the waters of the southern portion of the island have the highest O2 levels, while the middle of the island has the highest CO2 levels. Multiple variables contribute to the increasing and decreasing CO2 concentrations. The installation of a diesel power plant in 2017 and the increase in the number of motor vehicles on Gili Iyang island are among the contributing reasons. These have been delivering adverse implications for the island's ecosystem. [ABSTRACT FROM AUTHOR]

The commercially available SiO2 samples were successfully used as nuclear targets to study proton-induced reactions on oxygen in the energy range used in hadrontherapy. The stack of target was irradiated simultaneously with proton beam of initial energy equal to 58 MeV. The reactions (p,d), (p,α) and (p,αd) on 16O lead to the production of β+ emitters 15O, 13N and 11C. Their decay, leading to the emission of two 511 keV annihilation γ-quanta, was measured in LaBr3:Ce scintillation detectors. Decay spectroscopy of 511 keV line was applied, allowing to disentangle β+ decays with relative intensities determined within few % precision. No β+ activity originating from the short-lived reactions on Si was observed, as the measurements started few minutes after the irradiation. No significant modification of the surface of irradiated SiO2 targets was observed in AFM study; however, some changes are seen. [ABSTRACT FROM AUTHOR]

In this paper, for the first time, the mechanism of decomposition of the standard LP57 electrolyte during the charging of lithium-ion batteries was proved. It has been proven that the composition of the gases released during the decomposition of the standard electrolyte LP57 is the same as in the decomposition of the electrolyte EC within the experimental error. Therefore, in the LP57 electrolyte, EC decomposes mainly. It is shown that CO2, CO, and H2 gases are formed as a result of the decomposition of the LP57 electrolyte. Moreover, CO and H2 gases are formed as a result of electrochemical decomposition of the electrolyte, while CO2 gas is the result of the interaction of CO with atomic oxygen released from the active substance of the cathode. Therefore, the CO2/CO ratio in the evolved gas strongly depends on the amount of atomic oxygen released from the cathode. In turn, the amount of atomic oxygen released from the cathode strongly depends on the temperature and cutoff voltage during batteries charging. The proposed decomposition mechanism for the LP57 electrolyte corresponds to all known experimental data. [ABSTRACT FROM AUTHOR]

This study explores the use of hyperspectral imaging (HSI) to monitor the effectiveness of plasma-generated atomic oxygen (AO) treatment for non-invasive cleaning of cultural heritage object. Silk samples dyed with indigo blue, including those soiled with soot to mimic historical artifacts, were treated with plasma-generated atomic oxygen for varying durations. Using HSI with a TWINS [1,2] birefringent interferometer, diffuse reflectance and light-induced fluorescence are observed. That allowed a precise evaluation of sample degradation avoiding any invasive sample extraction. This research not only contributes to the field of cultural heritage conservation but also enhances understanding of indigo colour degradation processes and the evaluation of non-invasive cleaning techniques on sensitive materials. [ABSTRACT FROM AUTHOR]

The rapid growth of increased population, development in industrial and housing areas conducted land conversion phenomena that reduce the open green space in Batam City. Therefore, it is necessary to calculate the estimation of oxygen requirement based on existing open green space in Batam City to find the balance point and keep sustainable development. This research uses remote sensing data on Landsat-8 imagery to calculate how much-needed oxygen is toward existing open green space and determine whether the existing open green space can or cannot supply daily needs oxygen in Batam City. It uses transformation of NDVI, Gerrarkis and then will test data accuracy by validation. The validation results showed that the accuracy of index vegetation mapping is 87,4%, and based on these, the existing open green space in Batam City is 80849,53 Ha or 78% from total area Batam. Meanwhile, for estimating the human population, motor vehicles, farm animals, and industry oxygen requirement is 8842987,86 kg/day, by using the Gerrarkis method, the area of green space is 8733,81 Ha. So based on this research, it can conclude that the oxygen requirement in Batam City had fulfilled and balance to keep the sustainable development. [ABSTRACT FROM AUTHOR]

Influence of metal impurities of the VB–VIB groups on the oxygen absorption in the doped α2-Ti3Al and γ- TiAl alloys was studied by the projector augmented-wave method within the density functional theory. It was found that all considered atoms prefer to be on the Ti-sublattice. The doping leads to a decrease in the oxygen absorption energy, mainly due to the chemical contribution. The effect of the distance between impurity atoms on the interaction energy between them was also investigated. For both alloys, the most energetically preferred configurations of the impurity atoms were determined. The influence of two impurity atoms in these configurations on the oxygen absorption energy was evaluated. It was established that in the case of the Ti3Al alloy, this effect is additively enhanced and can be estimated as the sum of the effects of single atoms with accuracy of at least 91%. For the TiAl alloy, the effect of two impurity atoms is close to the effect of one nearest atom. [ABSTRACT FROM AUTHOR]

With the spread of pathogens like SARS-CoV-2, the urge for ergonomic disinfection techniques regained momentum. Ozone is a proven oxidizing agent that leaves no harmful residue after oxidation. Due to its green and cost-effective attributes, it is widely used for various industrial and domestic treatment/disinfection applications. In this paper, three mainstream Ozone generation methods i.e. (i) electrochemical method, (ii) ultraviolet ray method, and (iii) plasma discharge method are reviewed. The first step in Ozone generation involves the decomposition of molecular Oxygen into atomic Oxygen that requires the energy of certain intensity. This requirement of energy is fulfilled using Platinum coated PbO2 electrode, UV ray lamps with a certain range of wavelengths, and secondary streamers in plasma arc, respectively. In addition to the generation methods, various application of Ozone in wastewater treatment, fish-farming, food, and dairy industry, and odor treatment has also been reviewed. [ABSTRACT FROM AUTHOR]

The results of an intermediate meso-layer formation processes study between a PTFE base and a surface layer obtained by preliminary modification of polytetrafluoroethylene with zirconium dioxide, followed by ion-plasma molybdenum sputtering and laser ablation are presented. It was found that doping with zirconium dioxide makes the structure of polytetrafluoroethylene denser, and the ratio of atomic concentrations of fluorine and carbon decreases by 17%. It indicates a decrease in the number of saturated fluorocarbon bonds in the polymer and leads to a higher chemical activity of polytetrafluoroethylene. Upon surface modification with molybdenum and at laser radiation exposure, a change in the chemical composition towards an increase in the ratio of atomic concentrations of oxygen and molybdenum by 56% is observed on the surface, as well as the formation of close-packed individual particles of molybdenum oxides (Mo6+, Mo5+, Mo4+, Mo3+, Mo2+, Mo1+) from 3 to 15 µm in size were revealed. [ABSTRACT FROM AUTHOR]

The quality of pulp after delignification process is measured by the lignin content (Kappa Number) and viscosity (pulp strength). In this study, Eucalyptus Pellita was treated in Kraft process followed with oxygen delignification. The resulting pulp was then analyzed in term of Kappa number and viscosity. The aim of this work was to develop kinetic empirical model of oxygen delignification reaction and compare the Kappa number and viscosity obtained from experimental data with those from kinetic model. The experimental data was collected by varying the operating conditions of oxygen pressures, temperatures, alkali concentrations and heating times. The Kappa number decreased with the increasing of alkali concentration, oxygen pressure, temperature, and heating time, as well as for the viscosity. The value of both Kappa number and viscosity obtained from kinetic model were close enough to that obtained from experiment. Therefore, the kinetic model could be used to predict the optimum condition in oxygen delignification of kraft-pulped. [ABSTRACT FROM AUTHOR]

Nano Graphene Oxide (GO) has received much interest Because of its unique chemical and physical features. Because of its wide availability and inexpensive cost, GO is produced from a natural carbon source such as Graphite powder (40-100) micron. The oxidation method is a viable way of making large-scale GO. This study used a modified Hummers process to synthesize GO. The primary ingredients used were powder of Graphite, H2SO4 acid, and KMnO4 powder. FTIR, UV-vis, XRD, Raman spectroscopy, SEM, and EXD evaluated the GO structural synthesized and optical. The presence of groups oxygen-contained on the GO was determined by FTIR analysis. The UV-vis diffuse reflectance spectrum demonstrates the GO's optic absorption capabilities. For characterizing the crystal structure of the GO sheet, the XRD method was utilized. Raman spectroscopy was used to examine the structural and optical characteristics of the GO nanosheets as synthesized. SEM was used for the detailed morphological studies and EDX to determine the weight percentage of each element in the prepared GO. These results indicate that GO may be a potential new material used in several industrial applications, including removing heavy metal ions due to its high adsorption capacity. [ABSTRACT FROM AUTHOR]

Forests are the most important source of oxygen and have an essential role in the life of living things. Therefore, it is necessary to protect forests for ecological balance. However, forest fires disrupt the environmental balance and cause severe damage to forests. While forest fires are easy to put out when they first appear, it isn't easy to put out when they spread over large areas. Recently, images obtained from unmanned aerial vehicles have been used to detect forest fires by detecting fire and smoke in large areas. Deep learning algorithms provide faster and more accurate analysis of these images. This study uses the End to End Object Detection with Transformers (DETR) algorithm, a robust deep learning algorithm. Experimental studies show that the DETR algorithm has promising results in detecting forest fires. [ABSTRACT FROM AUTHOR]

There are many hazards for satellites within the Low Earth Orbit (LEO) environment: atomic oxygen (ATOX), ultraviolet and ionizing radiations, ultrahigh vacuum, thermal cycles, micrometeoroids, and debris. A significant concern for many satellite materials and structures is degradation resulting from ATOX which oxidises and erodes surfaces. This may result in loss of functionality and structural integrity, decreasing the lifespan of satellites and payloads. Defence Science and Technology Group (DSTG) is researching the effect of the space environment on satellite survivability. This study is examining key current and emerging structural materials in a ground-based ATOX-rich environment in order to gain an understanding of the resulting degradation and potential mitigation strategies. In this paper we discuss a glow phenomenon that was observed during the ATOX testing campaign. We present a potential explanation for the behaviour and discuss the influence of specimen holder design. These are important aspects to consider in order to ensure representative tests are being employed when designing space systems. [ABSTRACT FROM AUTHOR]

The Australian Department of Defence's Resilient Multi-Mission Space (RMS) Science, Technology and Research (STaR) Shot is a strategic research program established to develop future space technologies, demonstrating capability through a series of small satellite launches. A key theme of the RMS STaR Shot is to increase the resilience of the satellites and constellations to provide mission assurance for Defence. An important issue for resilience is the effect of atomic oxygen, one of the most significant hazards or risks to satellite materials in the low earth orbit. Materials intended for use on satellites are typically tested in ground-based facilities to match the atomic oxygen fluence experienced during satellite missions. However, in order to correlate these ground-based experiments to in-space results, the atomic oxygen fluence must be accurately measured both on the ground and in-space. The design of atomic oxygen fluence sensors for in-space experiments vary depending on many factors, including mission duration, orbit altitude, and whether or not the experiment is retrievable. This paper provides a review of the current state of art in atomic oxygen fluence sensors for in-space experiments for both retrievable and non-retrievable sensors. The review details the design of several fluence sensors utilised by different space organisations around the world, focusing on those developed recently. The outcome of this research will support resilient technology development in the RMS STaR Shot, as well as calibrating the ground-based extreme environment testing capabilities currently being developed by the Defence Science and Technology Group. The design, manufacture and implementation of an atomic oxygen sensor specifically created for the RMS satellite mission objectives will be essential to validation and verification of in-space atomic oxygen experimental results. [ABSTRACT FROM AUTHOR]

In recent decades, there has been an increasing interest in making use of satellite measurements for identifying trends in atmospheric composition and climate. Instruments like GOME-2 and TROPOMI are dedicated to air-quality and global trace gas monitoring. For the accurate retrieval of columnar information of the trace gases, cloud correction is necessary. This work is meant to examine the quality of the GOME-2 operational cloud product from AC SAF and to propose enhancements of the current dataset to improve the retrieval of the NO2 and HCHO tropospheric gases. [ABSTRACT FROM AUTHOR]

In this paper, we report the structural characteristics of Ti0.5Fe2.5O4/CS nanocomposite, synthesized through the coprecipitation method. Analysis of the formed nanocomposite particles' structure was successfully carried out by means of X-ray diffraction, and the functional groups were identified by means of Fourier-transform infrared spectroscopy. The morphology and average particle size were successfully observed and determined through scanning electron microscopy. The diffraction peaks confirmed the presence of Ti0.5Fe2O4 in the spinel structure, while the infrared spectrum analysis provided the functional groups of both elements with metal-oxygen bond identified at a wavenumber of 642.3 cm−1 and chitosan-typical functional groups such as amide I stretching vibration. The data analysis of scanning electron microscopy image exhibited an average particle size of 18.2 nm with agglomeration. [ABSTRACT FROM AUTHOR]

Dissolved oxygen (DO) is the amount of gaseous oxygen dissolved in water, which is influenced by atmospheric pressure, temperature, salinity, water turbulence, photosynthesis, respiration, and waste. The amount of dissolved oxygen DO in a river or lake represents the quality of water. Water molecules contain an oxygen atom. However, it is not needed by aquatic organisms living in natural water. This study aims to analyze the distribution of dissolved oxygen DO concentration distribution in the Kali Lamong river estuary during pandemic Covid-19 in.the dry season. The concentration of dissolved oxygen DO was measured by DO meter in real-time. The result demonstrated that the average concentration of dissolved oxygen dissolved oxygen concentration in the Kali Lamong river estuary was 5.29 mg/L. The results show that the water quality of Kali Lamong is classified in second class. These criteria indicate the water classification that can be utilized for water infrastructure/facilities. [ABSTRACT FROM AUTHOR]

The paper presents an experimental study of oxygen and acetylene mixture ratio for successful detonation in a Pulse Detonation Engine (PDE) arrangement. The experimental study was conducted by changing the measure of mass flow of acetylene-oxygen into the detonation tube at different pressures in the settling chamber of the PDE. The mixture ratio of the acetylene-oxygen blend regarding the valve opening period of acetylene-oxygen was plotted. The examination of mixture ration also characterizes the strategy which included the pattern of valves and constrains supply to achieve various benefits of filling fraction of the detonation tube. The outcomes tentatively anticipated the possible values of pressure in settling chamber for successful detonation in the PDE. [ABSTRACT FROM AUTHOR]

The influence of adsorbed oxygen on the properties of samples and the kinetics of spark plasma sintering of pure tungsten carbide and hard alloy powders has been investigated. It is shown that oxygen leads to the formation of W2C and η - phases in pure tungsten carbide and in hard alloys, respectively. It was found that adsorbed oxygen does not significantly affect the shrinkage kinetics of powder compacts. The activation energy of the intensive second stage of sintering of pure tungsten carbide and hard alloy powders was 9 and 12 kTm, respectively. Samples of pure tungsten carbide were characterized by high values of hardness (near 25 GPa) and crack resistance (4.7 MPa·m1/2). [ABSTRACT FROM AUTHOR]

Oxygen notably has high demand to be used in industrial applications. It is crucial that effective and efficient technology needs to be developed to coping this situation. Generally, oxygen is generated through cryogenic distillation, which requires the air to undergo cooling, compression, and further purification. It can produce almost 99% oxygen purity, but it is cost-intensive and has high energy consumption. Therefore, pressure swing adsorption (PSA) is developed for oxygen production, which has uncomplicated operating principles and is cost-efficient with generating relatively high product purity. In this paper, a brief review of pressure swing adsorption is presented. The usage of oxygen produced through pressure swing adsorption has been reviewed for on-board oxygen generation systems (OBOGS) and oxy-enriched incineration of municipal solid waste (MSW). In addition, assumptions and correlations for material, heat and energy balances, as well as the adsorption equilibrium are included. This work also addresses the suitable adsorbents to be used to generate oxygen through pressure swing adsorption. [ABSTRACT FROM AUTHOR]

LnBaMn2O6–δ (Ln = Nd, Sm) oxides were synthesized by the glycine–nitrate combustion method in 3 steps. The crystal structures of LnBaMn2O6–δ were found to possess a tetragonal cell with a space group of P4/mmm or P4/nmm for Ln = Nd or Sm, respectively. The oxygen content of LnBaMn2O6–δ determined iodometric titration methods was close to 6.0. TG measurements at a variable atmosphere (air or 5 % H2/Ar) were performed to simulate the single CLOU cycle. Both samples are demonstrated to weight loss down to 4.5 wt. % in 5% H2/Ar at 950 °C and reversible oxygen saturation in the air atmosphere at 400 °C was observed. The set of the observed characteristics of LnBaMn2O6–δ (Ln = Nd, Sm) distinguishes these materials as an effective oxygen carrier in a CLOU process. [ABSTRACT FROM AUTHOR]

A method for determining oxygen in a mixture of lithium and beryllium fluorides (FLiBe) was developed. The carrier gas hot extraction method was improved using a graphite cap and an inert chamber. This allowed the determination of oxygen in a relatively volatile FLiBe matrix containing a large amount of beryllium, which has a very high affinity for oxygen. [ABSTRACT FROM AUTHOR]

The influence of impurity and its concentration on the temperature-dependent diffusion coefficient of oxygen in α2-Ti3Al is studied using both a statistical and Landman's method. In the latter method, analytic expressions for oxygen diffusion coefficient along two directions are obtained. The first principle method within density functional theory was used for calculations of migration energy of oxygen jumps along different paths. The phonon frequencies required for estimating the jump rate are determined at initial and saddle oxygen sites. The factors that determine the oxygen diffusion in the alloy are revealed. We demonstrate that Landman's method applied in this work is validated by good agreement between the calculated oxygen diffusion coefficient and theoretical results obtained within the statistical approach as well as with available experimental data. [ABSTRACT FROM AUTHOR]

The photochromic properties of oxygen-containing yttrium hydride thin films are directly dependent on the oxygen concentration in the material. We use 16O/18O labelling to study oxidation of YH2 films. Oxygen penetrates the film through grain boundaries and intercolumnar voids oxidising the whole film thickness, without pronounced surface oxidation or self-passivation. Once oxidised, the mobility of oxygen in the films is low and no detectable changes in chemical composition of 18O-labeled YHO films is found under illumination. [ABSTRACT FROM AUTHOR]

The carbon/oxygen (C/O) ratio at the end of stellar helium burning is not known with sufficient accuracy due to the large uncertainty in the cross-section of the 12C(α, γ)16O reaction. We developed a new method to measure this reaction that is significantly different from the experimental efforts of the past four decades. Data were measured with vanishingly small background, inside one detector, that also serves as an active target (AT-TPC). Angular distributions of the 12C(α, γ)16O reaction were obtained by measuring the inverse 16O(γ, α)12C reaction with gamma-beams (from the HIγS facility) and an optical readout time projection chamber (O-TPC) detector. We agree with current world data on the measured total reaction cross-section. We further evidence the strength of our method with angular distributions measured over the 1–resonance at Ecm ~ 2.4 MeV. We extract the E1-E2 mixing phase angle (ϕ12) over this resonance and obtained values that follow the trend of prediction based on unitarity of the scattering amplitude. Our technique promises to yield results that will surpass the quality of the currently available data. We continue these measurements to lower energies at the HIγS facility of TUNL at Duke University, and anticipate measurements down to Ecm = 1.1 MeV at the ELI-NP, the EU facility in Romania.. [ABSTRACT FROM AUTHOR]

Samples of furnace carbon black of N 234 and N 330 grades with an oxygen content of 4–8% and an acidic pH value were obtained during the low-temperature oxidation by the ozone-oxygen mixture. The specific surface area of the samples does not change significantly during oxidative treatment. The pH value, texture parameters, oxygen content of oxidized furnace carbon black N234 are close to that of channel K354; so N234 can be recommended as a substitute for channel carbon black in the formulations of special-purpose rubbers and coloring compositions. [ABSTRACT FROM AUTHOR]

Jules Horowitz Reactor (JHR) irradiation test devices (so called ADELINE and MADISON) must undergo a periodic inspection every 40 months (French ESP(N) Regulation). The first step of inspection proposal was performed from October 2019 to March 2020 and concerns application of non-destructive methods for electron beam welds, while examining the possible methods and locations that could be utilized. This study has been performed in collaboration between VTT Technical Research Centre of Finland Ltd and French CEA with VTT employee secondment at CEA Cadarache. The initial conclusions of this work are the following: • Two inspection methods are likely needed. • Eddy current is likely suitable for surface examination while volumetric ultrasonic inspection can be used for tube bodies. • Inspection under-water in a storage pool (EPI) is likely the best option for location in the JHR. • Some automation and remote controls will be needed during the inspection process. The inspection area is quite large as the whole tube bodies will be inspected. • Internal surfaces located between the nested tubes likely cannot be inspected for corrosion and therefore, sealing the space from oxygen and water will be likely be the best option. • Experimental reference is a critical next step of the work to assess and qualify the inspection methods. As the next step, CEA will continue discussions on requirements of the mock-ups: for eddy current inspection, a Zircaloy-4 planar specimen with artificial reflectors is needed. For ultrasonic reference, a representative mock-up of the cylinder with a weld and artificial defect(s) is needed. The mock-up testing will provide an experimental reference to CIVA calculations as simulations of this work have been performed with CIVA software, which is extensively used in the industry and research organizations in simulation of non-destructive control. This study will allow further steps in the future, up to the qualification of inspection methods for JHR test devices. [ABSTRACT FROM AUTHOR]

This article presents the results of studies of the distribution profiles of implanted iron atoms into silicon, depending on the irradiation dose and annealing temperature by the RBS method. The results obtained confirm similar data obtained by SIMS. The effect of thermal annealing on the distribution of iron and other impurities, in particular, oxygen, has been studied. The possibility of using the RBS method for analyzing the concentration distribution of doped impurities and the interaction of impurities with each other is presented. [ABSTRACT FROM AUTHOR]

Currently, oxygen cylinders installed in an aircraft require refilling once to three times per production cycle for testing the oxygen system. Refilling a cylinder requires removal from the aircraft, transportation to the fill shop, performing the filling operation, returning to the aircraft, reinstallation, and retesting the oxygen system. Opportunity exist for damaging cylinders and contamination of the oxygen system along with adding a recurring potential for mistakes in the removal and installation of the cylinders and pressurization and depressurization of the system. A novel tool was developed to eliminate this lengthy and potentially hazardous way of working. Using the newly defined tool, oxygen cylinders no longer need removal from the aircraft. Only the pressure regulator must be removed from the cylinder assembly and the tool and fill cart attached to the cylinder, while remaining in its installed position. This process saves time and money as well as increases safety, both for personnel as well as for equipment. The tool is an assembly of existing qualified aircraft oxygen system parts and a pressure relief valve connected with copper based tubing. It is designed to minimize the potential fire hazard due to adiabatic compression heating during the filling operation. [ABSTRACT FROM AUTHOR]

This paper presents a way to solve the transfer rate equation of oxygen in water. After running a calculation program, the graph of the function that indicates the increase of the dissolved oxygen concentration in the water as a function of time is plotted. Constructed in an original manner, the experimental installation allows the measurement of the increase of the dissolved oxygen concentration in water. The experimental obtained results are compared with the theoretically obtained data. [ABSTRACT FROM AUTHOR]

Efficient and enhanced gas sensing especially at room temperature is the demand for contemporary industrial applications. This has been made possible due to a paradigm shift from semiconducting metal oxides to 2D materials including Graphene Oxide (GO) and reduced GO (RGO). GO and its derivatives have ushered in a revolution mainly because of their high surface to volume ratio and presence of various oxygen groups. Literature reports since 2010 indicate existence of investigations by many research groups wherein multiple approaches have been employed to enhance the gas sensing capabilities of GO and RGO. Some of the more radical approaches have been fabrication of free standing GO films, adoption of green fabrication techniques, thermal reduction and even implantation of nitrogen ions. However, quantitative augmentation of favourable oxygen species on the GO films envisaged to act as active sites for the target gas molecules (H2 and SO2 in the current investigation) is yet to be carried out. The present study reports enhancement in detection of gaseous species due to twin mechanisms of a) advantageous tailoring of surface morphology and b) presence of favourable oxygen species. Both the processes are shown to occur due to intentional incorporation of variations induced in the sonication process during synthesis of GO films. [ABSTRACT FROM AUTHOR]

Stable isotopic compositions of carbon and oxygen (δ13C et δ18O) measured from carbonates are used in geology to reconstruct paleotemperatures and to learn about the evolution of the biogeochemical carbon cycle. The standard technique used since the middle of the XXth century [1] to measure isotopic ratios is based on a wet chemical protocol which CO2 is evolved from the acidic dissolution of carbonates followed by quantification of CO2 molecules isotopologues using mass spectrometer or infrared spectroscopy. This is a lengthy protocol that necessitate to manipulate acid solution and numerous gas phases purification steps before isotopic measurements. Our new preparation technique aims at offering an alternative to the wet chemical preparation of the samples by using a direct extraction of CO2 via a laser-induced calcination process. In addition to save time, this method allows to consider spatially resolved and automated in-situ measurements and does not necessitate further purification steps of the evolved CO2 during calcination. [ABSTRACT FROM AUTHOR]

Currently, oxygen cylinders installed in an aircraft require refilling once to three times per production cycle for testing the oxygen system. Refilling a cylinder requires removal from the aircraft, transportation to the fill shop, performing the filling operation, returning to the aircraft, reinstallation, and retesting the oxygen system. Opportunity exist for damaging cylinders and contamination of the oxygen system along with adding a recurring potential for mistakes in the removal and installation of the cylinders and pressurization and depressurization of the system. A novel tool was developed to eliminate this lengthy and potentially hazardous way of working. Using the newly defined tool, oxygen cylinders no longer need removal from the aircraft. Only the pressure regulator must be removed from the cylinder assembly and the tool and fill cart attached to the cylinder, while remaining in its installed position. This process saves time and money as well as increases safety, both for personnel as well as for equipment. The tool is an assembly of existing qualified aircraft oxygen system parts and a pressure relief valve connected with copper based tubing. It is designed to minimize the potential fire hazard due to adiabatic compression heating during the filling operation. [ABSTRACT FROM AUTHOR]