Negative Oxygen Research Articles

Clustering rooting for the high heat resistance of some CHNO energetic materials

Highly thermostable energetic materials (EMs) are highly desired for deep underground and space exploration, and therefore have attracted much attention. This work employs four typical traditional EMs composed of C, H, N and O atoms as example to clarify the origin of high heat resistance, by means of molecular dynamics simulations with the molecular reactive forcefield of ReaxFF. These EMs include 3,5-dinitro-N,N´-bis(2,4,6-trinitrophenyl)pyridine-2,6-diamine (PYX), 1,3,5-diamino-2,4,6-trinitrobenzene (TATB) and 2,2´,4,4´,6,6´-hexanitrostilbene (HNS), which are highly thermostable with decomposition temperature peaks > 600 K, and a less one of pentaerythritol tetranitrate (PETN) for comparison. It is found that the clustering in the decomposition of PYX, TATB and HNS retards the extraction of small product molecules from clusters, as well as heat release, and thereby roots for their high heat resistance; while, the clustering in the PETN decay is negligible and heat release and fragmentation proceed rapidly, facilitating to fast decomposition. Combining this finding with the well-known molecular stability, this work presents a perspective on the high heat resistance of traditional EMs. Based on it, a highly negative oxygen balance, a high C content and a high molecular stability are proposed as a strategy for designing and constructing new highly heat-resistant EMs.

Time-resolved radial uniformity of pulse-modulated inductively coupled O2/Ar plasmas* *Project supported by the National Natural Science Foundation of China (Grant Nos. 11805150, 11875100, 11705141, and 11775282), the Dean Fund of the School of Optoelectronic Engineering (Grant No. 2019GDYT04), the Fund from the Xi’an Key Laboratory of Intelligent Detection and Perception (Grant No. 201805061ZD12CG45), and the Key Industry Innovation Chain Project

Time-resolved radial uniformity of pulse-modulated inductively coupled O2/Ar plasma has been investigated by means of a Langmuir probe as well as an optical probe in this paper. The radial uniformity of plasma has been discussed through analyzing the nonuniformity factor β (calculated by the measured n e, lower β means higher plasma radial uniformity). The results show that during the active-glow period, the radial distribution of n e exhibits an almost flat profile at the beginning phase, but it converts into a parabola-like profile during the steady state. The consequent evolution for β is that when the power is turned on, it declines to a minimum at first, and then it increases to a maximum, after that, it decays until it keeps constant. This phenomenon can be explained by the fact that the ionization gradually becomes stronger at the plasma center and meanwhile the rebuilt electric field (plasma potential and ambipolar potential) will confine the electrons at the plasma center as well. Besides, the mean electron energy (〈 ε 〉on) at the pulse beginning decreases with the increasing duty cycle. This will postpone the plasma ignition after the power is turned on. This phenomenon has been verified by the emission intensity of Ar (; = 750.4 nm). During the after-glow period, it is interesting to find that the electrons have a large depletion rate at the plasma center. Consequently, n e forms a hollow distribution in the radial direction at the late stage of after-glow. Therefore, β exhibits a maximum at the same time. This can be attributed to the formation of negative oxygen ion (O−) at the plasma center when the power has been turned off.

Understanding the role of energetic particles during the growth of TiO2 thin films by reactive magnetron sputtering through multi-scale Monte Carlo simulations and experimental deposition

In this paper, a previously established 3D multi-scale simulation chain of plasma deposition process, based on a combination of a direct simulation Monte Carlo (gas phase) algorithm and a kinetic Monte Carlo (kMC) (film growth) code, is improved by the addition of a particle-in-cell Monte Carlo collision algorithm in order to take into account and clarify the role of charged particles. The kinetic Monte Carlo code is also extended with a binary collision approximation algorithm to handle charged particles. This modelling strategy is successfully applied to the growth of TiO2 thin films by means of reactive magnetron sputtering. In order to highlight the effects of negative oxygen ions, two substrate locations are selected: one in the median plane of the targets and another one off the median plane. The model efficiently predicts the densities and fluxes of both charged and neutral particles towards the substrate. Typical results such as particle densities, the discharge current density and ion flux onto the target, and the various substrate locations are calculated. The angular distribution and energy distribution of all involved particles are sampled at these very same substrate locations and the nanoscale modelling (NASCAM) code, implementing the kMC approach, uses these results to explain the morphology of the experimentally deposited coatings. The changes throughout the transition from metallic deposition to stoichiometric TiO2 of the columnar structure of the deposited films is explained by the suppression of the atom diffusion on the growing film due to Ti oxidation. Moreover, the high-energy negative atomic oxygen ions originating from the targets are identified as the origin of the abnormally low inclination of the columnar structure experimentally observed for the oxide mode coatings. Measurements of the normalized energy flux (energy per deposited atom) are experimentally investigated to support and highlight the important role of energetic particles during film growth.

Highly Sensitive and Selective HCHO Sensor Based on Co Doped ZnO Hollow Microspheres Activated by UV Light

Low power consumption or even detecting harmful gases at room temperature is the future development trend of gas sensors. In this work, Co doped ZnO hollow microspheres were prepared by a facile water bath method. Co doping increases the electron density of ZnO and promotes the adsorption of oxygen on the surface. The surface band bending caused by oxygen adsorption further promotes the separation efficiency of photogenerated charge. The sensing results showed that 1.5 mol% Co doped ZnO exhibited the highest response of 111.6 to 50 ppm formaldehyde (HCHO) activated by UV light (6.8 mW/cm2) at room temperature. Moreover, the detection of limit can reach to 100 ppb, and the response and recovery time is 32 and 44 s, respectively. The excellent gas-sensing performance could be attributed to the increase in adsorbed negative oxygen species on the surface, the improved separation efficiency of photogenerated charge, and the porous and hollow microstructure of ZnO. In addition, the sensor possessed excellent reproducibility, selectivity, and a certain ability of moisture resistance.

Incorporating highly basic polyoxometalate anions comprising Nb or Ta into nanoscale reaction fields of porous ionic crystals.

Polyoxometalates (POMs) are oxide cluster anions composed of high-valence early transition metals and are widely used as catalysts. Yet base catalysis of POMs remains an ongoing challenge; group V (V, Nb, and Ta) elements form more negatively charged POMs than group VI (Mo and W) elements, and in particular, polyoxoniobates and polyoxotantalates are known to show strong basicity in solution due to the highly negative surface oxygen atoms. Herein, we report for the first time porous ionic crystals (PICs) comprising Nb or Ta. The PICs are composed of Dawson-type Nb/W or Ta/W mixed-addenda POMs with oxo-centered trinuclear CrIII carboxylates and potassium ions as counter cations to control the crystal structure. Among the PICs, those with Nb or Ta tri-substituted POMs exhibit the highest yield (78-82%) and selectivity (99%) towards the Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate (353 K, 6 h), which is a typical base-catalyzed reaction, as reusable solid catalysts, and they can also catalyze the reaction of other active methylene compounds. A detailed investigation into the crystal structures together with DFT calculations and in situ IR spectroscopy with methanol as a basic probe molecule shows that the exposure of [Nb3O13] or [Ta3O13] units with highly negative surface oxygen atoms to the pore surface of PICs is crucial to the catalytic performance. These findings based on the composition-structure-function relationships show that Nb- and Ta-containing PICs can serve as platforms for rational designing of heterogeneous base catalysts.

Чисельне моделювання нестаціонарних потоків холодної плазми при роботі плазмового актуатора

The numerical simulation of unsteady flows of cold plasma is considered in this article. A low-temperature non-equilibrium ideal plasma is formed when the plasma actuator interacts with the air. The mathematical model has been developed to describe the behavior of low-temperature plasma. It is based on non-stationary equations describing the dynamics of charged particles and plasma electrodynamics equations. The 14 types of particles: metastable and excited nitrogen and oxygen atoms, positive and negative ions, electrons and atomic oxygen are considered. Volumetric and surface chemical reactions describing processes in a barrier discharge that occur above the dielectric surface are considered. For non-stationary equations of plasma dynamics, an implicit numerical algorithm with pseudo-time iteration has been developed, which is based on a finite-volume approach. The equation for the electrostatic potential with sources was solved using the generalized minimal residual method with incomplete LU preconditioning. In non-stationary equations for the density of plasma particles, the drift derivatives were approximated using the TVD scheme with the MinMod limiter function. The derivatives in the equation for the electric potential were calculated using finite-volume relations taking into account the upwind approximation of the concentration of charged plasma particles. The numerical results of the generation, propagation and destruction of a streamer during a dielectric barrier discharge are obtained. The unsteady plasma characteristics in the region above the dielectric surface are analyzed, including the distribution of the particles density, electric potential and the Lorentz force components. The results of numerical simulation of unsteady flows of low-temperature plasma are in good agreement with the available experimental data.

Modeling the Physical Properties of ZnO Nanoparticles with Selective Hydrogen Using DFT

The impact of hydrogen on the conductivity and vibration for zinc oxide (ZnO) nanoparticles had implicated for nanoscale optoelectronic units. Infrared reflectance spectra for ZnO hydrogen-annealed nanoparticles were calculated at incidence. The theory of density functional theory is applied to the reflectance model and absorption spectra. There is an agreement between both the model suggesting that the nanoparticles have inhomogeneous carriers’ concentrations and the experimental results. A significant decrease in carrier concentration resulted from exposure to oxygen for several hours, according to the adsorption on the nanoparticle surface of negative oxygen molecules. Also, the density of states in deferent wurtzoid’s size has been studied. The experimental energy gap values of bulk ZnO, HOMO and LUMO levels as a function of the total Zn and O atoms number in ZnOH diamondoids were determined, as well as the bond length in deferent wurtzoid’s size where the experimental ZnO bond length at 1.9767 Å has been calculated. The tetrahedral angles in deferent wurtzoid’s size were studied, deferent wurtzoid’s size Reduced mass as a vibration frequency function and force constant as a function of vibrational frequency in deferent wurtzoid’s size were determined. A good result for infrared as a vibration frequency function in deferent wurtzoid’s size has been found, as well as Raman as a vibration frequency function in deferent wurtzoid’s size.

In the Subtropical Monsoon Climate High-Density City, What Features of the Neighborhood Environment Matter Most for Public Health?

Urbanization and climate change have been rapidly occurring globally. Evidence-based healthy city development is required to improve living quality and mitigate the adverse impact of the outdoor neighborhood environment on public health. Taking Guangzhou as an example to explore the association of neighborhood environment and public health and preferably to offer some implications for better future city development, we measured ten environmental factors (temperature (T), wind-chill index (WCI), thermal stress index (HSI), relative humidity (RH), average wind speed (AWS), negative oxygen ions (NOI), PM2.5, luminous flux (LF), and illuminance (I)) in four seasons in four typical neighborhoods, and the SF-36 health scale was employed to assess the physical and mental health of neighborhood residents in nine subscales (health transition(HT), physiological functions (PF), general health status (GH), physical pain (BP), physiological functions (RP), energy vitality (VT), mental health (MH), social function (SF), and emotional functions (RE)). The linear mixed model was used in an analysis of variance. We ranked the different environmental factors in relation to aspects of health and weighted them accordingly. Generally, the thermal environment had the greatest impact on both physical and mental health and the atmospheric environment and wind environment had the least impact on physical health and mental health, respectively. In addition, the physical health of the resident was more greatly affected by the environment than mental health. According to the results, we make a number of strategic suggestions for the renewal of the outdoor neighborhood environment in subtropical monsoon climate high-density cities and provide a theoretical basis for improving public health through landscape architecture at the neighborhood scale.

Origin of the penecontemporaneous sucrosic dolomite in the Permian Qixia Formation, northwestern Sichuan Basin, SW China

Abstract The characteristics, formation time, and origin of the sucrosic dolomite reservoirs in the Permian Qixia Formation of northwestern Sichuan Basin are analyzed. Core and outcrop description and microscopic analysis of the sucrosic dolomite samples are carried out. It is found that the dolomite has typical features different from other kinds of dolomites: (1) This dolomite is generally medium-coarse in crystal size, and often associated with very finely to finely crystalline dolomite and cave-filling dolomite. (2) Typical identification marks of eogenetic karstification are developed at the top of the upward-shallowing sequence. (3) The medium-coarse crystalline sucrosic dolomite is cut by the early diagenetic karst fabric, and is characterized by dolomite with dissolution edge, dolomite vadose silt in pores, and transgression clay filling between the medium-coarse dolomite crystals. The medium-coarse crystalline sucrosic dolomite was formed earlier than the eogenetic karstification. The sucrosic dolomite with occasional cloudy core and clear rim has bright cathodoluminescence, high inclusions temperature, significant negative skewness carbon and oxygen isotopic compositions, and rare-earth element (REE) pattern similar to seawater, indicating it experienced two periods of dolomitization, evaporative concentration reflux-infiltration and penecontemporaneous seawater circulation hydrothermal fluid dolomitization. The study results not only update the understanding on the dolomitization time of Qixia Formation, demonstrate that the sucrosic dolomite can be formed in the penecontemporaneous stage when seawater reflux superimposed with hydrothermal fluid effects, but also show that the taphorogenesis in the Dongwu period began in the Early Permian. Moreover, the dolomite controlled by the grain bank migration and terrain in the slope break appears in bands of large scale, this knowledge provides basis for expanding the exploration field of this type of reservoirs.

Fabrication and Electrochemical Evaluation of Organic Secondary Battery Capable of Charging and Discharging in Neutral Solution

There are attractive attentions on organic secondary batteries as new energy storage devices, in which organic compounds as electrode active materials supported on a porous carbon. Dilute sulfuric acid and organic solvents were used as electrolytes1,2). On the other hand, an organic electrolyte has a risk of ignition, and an acidic electrolyte is low safety when leaked.In this study, we newly fabricated an organic secondary battery that can be charged and discharged with a non-flammable, non-poisonous neutral aqueous solution, and evaluated its electrochemical performance.4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl-benzoate (TEMPO-benzoate) was used as the cathode active material, and 9,10-anthraquinone (AQ) was used as the anode active material. Both active materials are hydrophobic and expected to overcome the problem of elution of the active material into the electrolyte.Firstly, carbon cloth was immersed in a slurry of acetylene black and polyvinylidene fluoride (PVdF) ultrasonically dispersed in N-methyl-2-pyrrolidone (NMP) and dried at 60 ° C for 48 hours. Next, each active material solution was dropped, dried under reduced pressure for 4 hours to adsorb each active material, and a porous carbon electrode was produced. For single electrode evaluation, cyclic voltammetry was performed at a scanning speed of 10 mV s-1. The as-fabricated electrodes were used as the working electrode, a platinum mesh was used as the counter electrode, a saturated KCl/Ag/AgCl electrode (SSE) was used as the reference electrode, and a 1 mol/dm3 KCl aqueous solution was used as the electrolyte. An organic secondary battery was fabricated using the as-fabricated electrode, and electrochemical evaluation was performed by a charge and discharge test using a reference electrode. A cellophane was used for the separator.Figure 1 (A) shows the reaction mechanism of the active materials of both electrodes used in this study. Figure 1 (B) and (C) show the cyclic voltammograms of AQ and TEMPO-benzoate. It was found that AQ showed an anodic peak near -0.65 V vs. SSE and a cathodic peak near -0.8 V vs. SSE (Fig. 1(B)). The anodic current and cathodic current is related to the two-electron transfer reaction between quinone and hydroquinone shown on the left side of Fig.1 (A). TEMPO-benzoate showed an anodic peak near 0.85 V vs. SSE and a cathodic peak near 0.65 V vs. SSE (Fig. 1(C)) due to the one-electron transfer reaction between the NO radical and the NO cation on TEMPO-benzoate shown on the right side of Fig. 1 (A). The peak appeared near 1.1 V vs. SSE in Fig. 1 (C) is considered to be due to chlorine gas generation on the electrode surface by chloride ions in the electrolyte.Figure1 (D) shows the results of a charge and discharge test performed by applying a constant current of 820 mA to an organic secondary battery. The cut-off voltage were 2 V and 0.4 V, respectively. A large irreversible capacity appeared during the first charge. The potentials of the two electrodes during charging and discharging using the reference electrode suggested that reduction of dissolved oxygen in the negative electrode and oxygen in the porous carbon pores and side reactions were caused. On the other hand, it was confirmed that charge and discharge was performed stably repeatedly after the first discharge. We also tried to improve cycling characteristics by suppressing irreversible capacity by performing thorough degassing of porous carbon and degassing of electrolyte, and assembling cells in an inert gas atmosphere. References 1) T. Tomai et al., Scientific reports, 4, 3591 (2014).2) B. Huskinson et al., Nature, 505, 195-198 (2014). Acknowledgments This work was partially supported by JST-ASTEP Grant Number JPMJTS1513, JSPS Grant Number 17H02162 and Private University Research Branding Project (2017-2019) from Ministry of Education, Culture, Sports, Science and Technology, and Tokyo University of Science Grant for President's Research Promotion． Figure 1

Dose–response relationship between local anesthetic volume and hemidiaphragmatic paresis following ultrasound-guided supraclavicular brachial plexus blockade

BackgroundThere is no consensus regarding what volume of local anesthetic should be used to achieve successful supraclavicular block while minimizing hemidiaphragmatic paresis (HDP). This study investigated the dose–response relationship between...

Reduction of peroxynitrite by some manganoporphyrins of AEOL series: DFT approach with dispersion correction and NBO analysis

The AEOL series of manganoporphyrins (MnP; AEOL compounds were named by US Aeolus pharmaceuticals) designed as superoxide dismutase mimic are well-known for their powerful catalytic activity to neutralize reactive oxygen and nitrogen species. Reductive oxygen atom cleavage from peroxynitrite (ONOO−) to form NO2 in aqueous solution by some AEOL compounds (AEOL-10113, AEOL-10150, AEOL-11114 and AEOL-11203) was studied by DFT/M06-2X computations with D3 dispersion correction and gCP (geometrical counterpoise correction) for basis set superposition error. DFT computation showed that AEOL-10150 can form the most stable association complex {MnP…OONO} among four AEOL models. AEOL-10150 complex with ONOO− has the lowest deformation energy. In AEOL compounds and their association complexes with ONOO−, Mn atom prefered the high spin state (S = 2) to the intermediate spin state (S = 1). Natural bond orbital analysis showed that electron transfer from the most negative oxygen atom in ONOO− to Mn atom in MnP has the biggest interaction energy among all kinds of donor-acceptor interactions between ONOO− and MnP.

Spectroscopic study of the HII regions in the NGC 1232 galaxy

Context. NGC 1232 is a face-on spiral galaxy that serves as an excellent laboratory for the study of star formation due to its proximity. Recent studies have revealed interesting features about this galaxy: X-ray observations suggest that it recently collided with a dwarf galaxy, however, no apparent remnant is observed. Aims. In this study, we search for evidence of this possible collision. Methods. We used long-slit optical spectra of the galaxy in two different positions obtained with the Goodman spectrograph at the SOAR telescope. Results. We detected 18 HII regions in the north-south direction and 22 HII regions in the east-west direction and a background galaxy, NGC 1232B, for which we present the first redshift measurement and spectral analysis. We used the stellar population fitting technique to study the underlying stellar population of NGC 1232 and NGC 1232B and to subtract it from the spectra to measure the emission lines. The emission lines were used to determine the extinction, electron density, chemical abundance, and the star-formation rate gradient of NGC 1232. Conclusions. As is common in spiral galaxies, we found a stellar population gradient with older populations at the central regions and younger ones towards the outskirts, along with a negative oxygen abundance gradient of −0.16 dex/re. Due to the difficulty of measuring important emission lines, the number of objects for the abundance gradient is small, but there is a hint that this galaxy has a broken gradient profile, with a drop towards the center. Some authors have explained this effect as the result of a satellite collision, but observations of a large sample of spiral galaxies shows evidence that goes against such a mechanism. If the collision caused any disturbance in the galaxy, we believe it would be small and hard to detect with a limited number of objects. From all the other measurements, we found no deviations from a typical spiral galaxy and no significant difference between different directions in the galaxy. The stellar population and emission line analysis of NGC 1232B suggest that it is a starburst galaxy.

Mechanical and radiation-shielding properties of B2O3–P2O5–Li2O–MoO3 glasses

Amassed borophosphate lithium molybdate samples were synthesized by the melting classical technique. To check the conditions of these synthesized glasses, the X-ray diffractometer technique was applied. The density value of these samples was increased as well as the molar volume decreased. The mechanical characteristics were linked with Fourier-transform infrared spectrum results. The addition of MoO3 increases the polymerization degree and changes the basic boring units from BO3 to BO4, increases the polymerization degree of phosphate network and changes the negative non-bridging oxygen to positive charges. Ultrasonic velocities and elastic modulus (experimental and theoretical) are increased. This behaviour is correlated to the substitution of Li–O with Mo–O linkages. Mass attenuation coefficient of the prepared samples decreased with the energy increase and with the addition of MoO3. With the increase in photon energy and MoO3 half value layer, the tenth value layer and the mean free path values increase. Hence, the increase of MoO3 leads to a better attenuation of gamma radiation. Therefore, the glass under investigation had superior characteristics for radiation protection applications.

Lithium ion specific fluorescent reversible extraction-release based on spiropyran isomerization combining crown ether coordination and its bioimaging

Lithium is a potent mood stabilizer and has unusual clinical, pharmacological, and biochemical properties. Therefore, it is of great significance to develop fluorescent probes to monitor Li+ in living cells visually. The emission wavelength of the reported Li+ fluorescent probes was mostly in the short-wave region, which is greatly interfered by the biological background fluorescence and not suitable for biological imaging. In view of the above shortcomings, we constructed a red emitted fluorescent probe by utilizing the spiropyran derivative as fluorophore and integrating the aza-12-crown-4 as the recognition site of Li+. Li+ induced the isomerization of spiropyran (fluorescent emission) to release oxygen negative ions, which combined with the coordination effect of crown ether to realize the specific fluorescence detection of lithium ion. The system was used for biological imaging in Hela cells and zebrafish. We believe that the current project will provide an effective visualization tool for studying the biological functions of lithium ions.

Enhancing methanogenesis in fed-batch anaerobic digestion of high-strength sulfate-rich wastewater using zero valent scrap iron

The aim of this study was to evaluate the addition of zero valent iron (ZVI) in scrap form to an anaerobic digestion reactor in order to enhance methane production from high-strength, sulfate-rich wastewater. The wastewater contained 6,000 mg/L COD and 3,000 mg/L sulfate. From an initial set of batch tests, the addition of either ZVI powder or ZVI scrap to the medium resulted in comparable methane yields of around 0.13 L CH4/g COD added. In a fed-batch operation treating the sulfate-rich wastewater for 60 days, the reactor with added ZVI scrap was found to have higher media pH (6.3-8.1), increased sulfate reduction efficiency (65-85%) and higher concentrations of dissociated sulfide (106-1,020 mg S/L) than a fed-batch operation without added ZVI scrap. The reactor with added ZVI had a maximum methane yield of 0.25 L CH4/g COD added⋅day and a maximum methane composition in the biogas of 53%. In contrast, the control reactor without added ZVI gave a methane yield of 0.07 L CH4/g COD added⋅day and a methane composition in the biogas of 27%. The control reactor also had higher concentrations of undissociated sulfide (153-612 mg S/L) and relatively high volatile fatty acids (VFA) to alkalinity ratios (0.4-0.7 g CH3COOH/g CaCO3). The experimental results suggested that ZVI provided favorable pH values for methanogenesis, reduced the toxicity of sulfides and thus enhanced the competitiveness of methanogens with sulfate-reducing bacteria (SRB). Moreover, the larger negative oxygen reduction potential (ORP) values in the reactor with added ZVI scrap indicated that the ZVI might enhance electron transfer activities of microbes in the reactor.

Oxygen Homeostasis and Mitochondrial Function in COVID-19 and ARDS Patients: The Ultimate Vital Signs

The leading cause of death from the COVID-19 is the development of Pneumonia and Acute Respiratory Distress Syndrome-ARDS. Advanced physiological monitoring of COVID -19 patients in real time is a missing tool that avoid the optimization of better diagnosis and evaluating the efficacy of the treatment given. As of today, the monitoring of the systemic vital signs provides important information regarding the respiratory and cardiovascular systems including the pulse oximetry that provide data on hemoglobin oxygenation in the macro circulation. Our hypothesis is that the pathophysiology of COVID-19 and ARDS patients includes severe changes in the microcirculatory hemodynamics and cellular disturbances in Tissue and cellular Oxygen Homeostasis. Therefore, we postulate that real time monitoring of mitochondrial NADH redox state and microcirculatory blood flow, volume and hemoglobin oxygenation is the missing information that will affect dramatically the outcome of COVID-19 and ARDS patients. During the last 2 decades we studied the mechanism of blood flow redistribution activated in animal models as well as in patients exposed to total body negative oxygen balance. This mechanism is activated by the sympathetic pathway. This effect is not equal in all organs of the body, namely, in the most vital organs - brain, heart, and adrenal glands oxygen supply is preserved while in the less vital organs (visceral and peripheral organs) hypo perfusion and negative oxygen balance is recorded. In order to evaluate the tissue oxygen homeostasis, we developed a new concept named - LifenLight Score (LLS)TM based on the monitoring of four physiological parameters measured in real time from one of the less vital organs in the body. Our developed device is monitoring mitochondrial function by measuring the NADH auto fluorescence and microcirculatory blood flow, tissue reflectance and hemoglobin oxygenation. In animal model we monitored simultaneously the brain and the small intestine. In patients we used a 3-way Foley catheter introduced to the bladder via the urethra. We found that monitoring the less vital organ could serve as an early warning signal to the development of negative oxygen balance in the body as well as indicate of a recovery process in the improvement of the oxygen balance homeostasis. In conclusion, we hypothesize that using our new monitoring system will be able to detect deterioration process related to hypoxia in COVID-19 and ARDS patients, as well as to monitor improvement in tissue oxygen balance due to various treatments such as exposure to hyperoxia.

A study on negative oxygen ions shunting based on direct current pulsating co-frequency coupled electric fields method

This paper aims to explore the feasibility and stability of negative oxygen ions (NOI) shunting based on direct current (DC) pulsating co-frequency coupled electric field method, and the safeness under a high anion concentration. Negative oxygen ions were obtained under corona electric discharge from high negative voltage, a shunting method which was employed to detach the negative ions and neutral gas was executed with an uncoupled and a coupled electric field. In coupled field, the negative ions were exported with the same electric field derived from the ion emission polar as a guiding polar, while neutral gas was exported from another outlet; In uncoupled electric field, the purity of NOI from guiding polar powered separately is employed as a control group. Safeness test was approached with 2 rats under a normal cage system. The purity(separate) ratio of NOI between the guide outlet and the neutral gas outlet is 8.5, while the separate ratio is 163636.4 in the coupled electric field respectively. The purity of NOI is 18 million per cm3 in coupled electric field and 9.8 million per cm3 in uncoupled electric field. The purity of NOI is 180 million/cm3 under a voltage of -26 kV. The purity and separate ratio of NOI could be improved significantly after using the coupled electric field compared to uncoupled electric field.

Highly accurate tuning of current–voltage characteristic shift in a photo-sensitive three terminal metal–insulator–semiconductor device

We present a planar three terminal device fabricated on a silicon-on-insulator substrate. The device is based on a two-layer dielectric stack comprising SiO2 tunneling and HfO2 layers. A so-called gate electrode is placed between two other contacts, of the source and drain, all deposited on the insulator stack. In the dark as well as under illumination, the current–voltage characteristic can be shifted in an ideal linear manner with changes in a positive gate voltage with the shift being somewhat larger under illumination. The reason for the change of shift is the ability of high-density oxygen vacancies, arranged in the filament regions within an HfO2 sublayer that was voltage stress. Namely, holes or electrons are trapped in the HfO2 sublayer, respectively, from the inverted or accumulated Si layer. This process is controlled by the gate and drain bias levels. Moreover, under illumination and at negative gate and drain voltages, the device exhibits negative differential resistance caused by capture of photo-generated minority carriers induced in the depletion region of the Si after they tunnel through the SiO2 layer by negative oxygen vacancies that migrate to the SiO2/HfO2 interface through the filament regions. Finally, the low level of saturation current in the dark and the ability to precisely control its value by illumination intensity, together with a large sensitivity of 80–85 A/W and 25 A/W, at 490 nm and 365 nm, respectively, allow additional applications that cannot be achieved with conventional MIS devices.

Lowering the resistivity of aluminum doped zinc oxide thin films by controlling the self-bias during RF magnetron sputtering

Transparent conducting thin films based on aluminum-doped zinc oxide are regarded as a viable alternative for low-cost and large-area applications such as solar cells and smart windows. Despite of intensive research, the thin film growth mechanism by magnetron sputtering is under debate concerning the role of energetic oxygen negative ions and the spatial distribution of atomic oxygen during the deposition. As the negative ions energy is directly related to the self-bias during RF driven magnetron sputtering, this work demonstrates a method to lower the thin film resistivity with a factor above 2 by including a tuning electrode between the target and the substrate. The electrode increases the RF coupling, reduces the dc self-bias and improves the electronic properties uniformity over the substrate. Consequently, resistivity below 3 × 10−3 Ωcm is obtained over a substrate area comparable with the target surface for an averaged transmittance above 90% without intentional substrate heating.