H2O2 Peroxidation Research Articles

The Biochemical Role of Pomegranate Peel Extract in Tissues Antioxidants of High Sucrose Stressed Rabbits

Pomegranate (Pomg) fruit contains many phenolic compounds with high antioxidant activity, which may have useful health properties including flavonoids anthocyanins, flavonoids and hydrolysable tannins (punicalagin). The pomegranate peel includes tannins, gallagic acid ellagic acid and its esters of glucose and flavonoids. Oxidative stress is an imbalance between free radical production and the antioxidant defense system which could lead to lipid, protein and/or DNA alterations in this respect, the possibility exists that sucrose feeding facilitates oxidative damage. For the present study, the strong antioxidant activity of POMG on some antioxidant parameters in liver and heart of male rabbits exposed to high sucrose diet (HSD) induced oxidative stress, were investigated. Eighty (80) male rabbits at age of 4 weeks, weighting 500- 600 g. were used in this study. The rabbits were divided into four equal groups. 1) Control Normal group: kept on basal ration. 2) Stressed group (HSD): reared on the 25% sucrose concentration ration, daily for 4 months. 3) Pomegranate peel extract (PPE) group: reared on 25% pomegranate peel powder ration only, daily for 4 months. 4)Sucrose + PPE: kept on equal amounts of 25% sucrose and 25% PPE rations, daily for 4 months. Liver and heart samples were collected from all animal groups two times, after 2 and 4 months of experiment period. Levels of reduced glutathione (GSH) and activities of Catalase (CAT) and Glutathione-S-Transferase (GST) were determined in liver and heart tissues. Extent of oxidative stress was also assessed by liver and heart lipid peroxide L-Malondialdehyde (MDA) and Hydrogen peroxide H2O2. The obtained results revealed that, HSD supplementation exhibited a significant increase in: 1) Liver and heart MDA and H2O2 concentrations. PPE supplementation to stressed rabbits exhibited a significant decrease in the previously mentioned parameters. On contrast, HSD supplementation exhibited a significant decrease in liver and heart GSH, CAT and GST. Supplementation of PPE to stressed rabbits exhibited a significant increase in all mentioned parameters. From the obtained results, it could be concluded that, the potential of POMG as natural antioxidant act as a powerful agent against the harmful effects of sucrose induced oxidative stress.

Ferrate(VI) based chemical oxidation for the remediation of aged PCB contaminated soil: Comparison with conventional oxidants and study of limiting factors

Ferrate (Fe(VI)) has emerged as an efficient oxidant to treat organic pollutants in aqueous solution. However, its application has never been assessed to remediate the contaminated soils. Here, we report the first study to use Fe(VI) for chemical oxidation of PCBs in historically contaminated soils obtained from an industrial wasteland. The first part of this study explores the efficiency of ferrate(VI) to degrade PCBs under various experimental conditions (liquid/solid ratio, oxidant dose, temperature and reaction time). Integrated application of Fe(VI) with conventional oxidants (hydrogen peroxide H2O2, persulfate S2O82− and peroxymonosulfate HSO5−) was also tested. Conventional oxidants resulted in only 2–12% PCB degradation while Fe(VI) removed 30% of PCBs. Integrated use of Fe(VI) and conventional oxidants improved the degradation efficiency which was the highest (40% removal) by Fe(VI)/HSO5−. This could be attributed to two-step degradation proceeding firstly by electron transfer with Fe(VI) followed by radical attack of conventional oxidants. To evaluate if PCB degradation is limited by soil factors, role of carbonate content, overall soil matrix, and PCB availability were assessed as a second part of this study. Negative role of soil matrix was highly prominent for conventional oxidants than Fe(VI). An increase in PCB availability improved the treatment efficiency (45% removal by Fe(VI) alone) highlighting the role of soil factors. All these results indicate the higher suitability and efficiency of Fe(VI) as compared to the conventional oxidants for soil remediation. Since use of Fe(VI) is innovative for both soil remediation and PCB oxidation, degradation mechanisms are also proposed.

Durable and Cost Effective Oxygen Electrode Prepared By Electrodeposition for Proton Exchange Membrane Water Electrolyzer (PEMWE)

Hydrogen gas has been regarded as future energy medium for the zero-carbon, hydrogen-based energy ecosystem. For decades, however, majority of hydrogen gas (96%) has been produced by petrochemical processes that emit CO2 into atmosphere. As an effort to facilitate carbon-free energy ecosystem, the water electrolysis (WE), a technology to split water into hydrogen and oxygen using renewable sources, has been received much attention. Currently, alkaline water electrolyzer (AWE) has dominated the commercial market due to its technical maturity that provides low price. However, the drawbacks such as a need for large-scale plant and the use of toxic solvent has limited its further application on small size WE. As an alternative, the proton exchange membrane water electrolyzer (PEMWE) has been researched and recently commercialized. Advantages of this technology include compact design, high energy efficiency and high H2 purity, which is suitable to small- and medium-scale electrolyzer (<300 kW). PEMWE running at high temperature (100-150℃), also referred as to high temperature PEMWE (HT-PEMWE) is beneficial in both thermodynamic and kinetic points of views relative to conventional PEMWE (60–90℃). The better cell efficiency is associated with fast electrode reactions due to better electrode kinetics and lower equilibrium voltages. The drawbacks of high temperature operation is relatively inferior cell stability resulting from high operating temperature, which inevitably increases the stack replacement cost. The cell is severely degraded during HT-PEMWE operation, and the degradation rate become faster when the operating temperature increases. One of the major degradation source is a contact loss between IrO2 and Ti DL. The recent studies showed that Ti is rapidly passivated and corroded at high temperature (>100℃) and anodic potential (>1.0 VSHE). This process would severely degrade the DL and BP, though the impact of Ti corrosion has not been experimentally explored yet. In this study, electrodeposited IrO2 is suggested as a corrosion-protective film that suppresses the passivation of the inner Ti substrate, while also acting as a cost-effective catalyst layer for OER. An IrO2 film of submicron thickness was uniformly deposited over the entire surface of porous Ti mesh via anodic electrodeposition. The properties of the IrO2 film were examined and the performance and stability of this electrode were assessed at the single-cell level. Membrane electrode assembly (MEA) was prepared by placing the oxygen (IrO­2/Ti mesh) and hydrogen electrodes (Pt/C) onto either sides of nafion membrane (NR-212, Dupont). Oxygen electrode was prepared via anodic electrodeposition of IrO2 onto porous Ti diffusion layer in the bath of 10 mM iridium chloride hydrate (IrCl4H2O), 100 mM hydrogen peroxide H2O2, 40 mM oxalic acid (COOH22H2O, 340 mM potassium carbonate (KCO3). Ti mesh and standard calomel electrode (SCE) were employed as counter and reference electrodes, respectively. Hydrogen electrode was prepared via spraying the catalyst ink composed of 46.5wt% Pt/C (Johnson Matthey), 5 wt% nafion solution, isopropyl alcohol (IPA, J.T. Baker), and deionized water on commercial carbon paper (39BC, SGL carbon). As shown in Fig. 1, electrodeposited IrO2 film played dual roles as not only the catalyst layer toward oxygen evolution reaction (OER) but also the corrosion-protection layer preventing inner Ti from oxidation. The e-IrO2/Ti resulted in high performance (0.97 A/cm2) despite low IrO2 loading (0.4 mg/cm2) in single cell test conducted at 1.6 V and 120oC, which was comparable to that of conventional electrodes with more catalyst loading. Furthermore, the corrosion polarization test revealed that the coated IrO2 film physically blocked the exposure of Ti diffusion layer, and thus reduced the corrosion of Ti in acidic condition. Therefore, the low degradation rate (1.5 mA/cm2-hr (0.11 %/hr)) was obtained in aging experiment at 120℃ and 1.72 V (voltage efficiency : 85%), confirming the excellent stability of this electrode. Figure 1

Formation of OH Groups and Hydrogen Peroxide Molecules on the Tio2 Anatase Surface: Pseudopotential Calculations

The density functional pseudopotential simulation was carried out to study dissociation of the H2O molecule on the TiO2 anatase surface (pure and W doped). Formation and desorption of the OH groups were studied, and it was shown that the adding of tungsten into titanium dioxide leads to reduction of the desorption energy of OH groups from 6.06 eV to 4.74 eV. Creation of the hydrogen peroxide H2O2 molecules was also investigated. Substitution of Ti with W on the TiO2 anatase surface decreases the formation energy of hydrogen peroxide molecules and moves it up to the range of visible sun light. Decrease of the formation energy of free OH groups and H2O2 molecules, which are fissile oxidizers, increases their quantity in water and promotes increase in effectiveness of organic pollutants decomposition.

Green synthesis and characterization of biologically active nanosilver from seed extract of Gardenia jasminoides Ellis

This article reports the utilization of seed extract (GSE) from Gardenia jasminoides Ellis. in the synthesis of silver nanoparticles (Gs-AgNPs) with versatile biological activities. The synthesized Gs-AgNPs were spherical in shape, crystal lattice with an average size of 20 nm as confirmed by UV–vis spectrum, X-ray diffractometer (XRD), Transmission electron microscopy with Energy dispersive X-ray spectroscopy (TEM-EDS) and particle size analyses (PSA). Phenolic compounds, proteins, and terpenoids were likely involved in the Gs-AgNPs synthesis, as indicated by Fourier-transform infrared spectroscopy (FTIR) analysis. The minimum bactericidal concentration (MBC) of the Gs-AgNPs was 12.5 μg·ml−1 for S. enterica Typhimurium and 10 μg·ml−1 for S. aureus. The MBC of the Gs-AgNPs induced >70% bacterial cell death within 60 min, as confirmed by growth curve analysis followed by Confocal laser scanning microscope (CLSM). Gs-AgNPs showed the highest scavenging activity for 1, 2-diphenyl-1-picrylhydrazyl DPPH radical (92.3 ± 0.86%), Nitric oxide (NO) radical (72.5 ± 2.15%), and Hydrogen peroxide H2O2 radical (85.25 ± 1.45%). Anticancer results revealed an IC50 of 15.625 ± 1.3 μg·ml−1 for Gs-AgNPs, whereas it was 580.54 ± 2.5 μg·ml−1 for GSE. The Gs-AgNPs generated high reactive oxygen species (ROS) resulting in induced apoptosis as evident by up-regulation of apoptosis-related protein. In addition, the photocatalytic results revealed about 92% of the reduction in Coomassie Brilliant Blue dye color with Gs-AgNPs. Hence, this work provided economically viable and ecologically sustainable Gs-AgNPs as an alternative biomaterial for future therapeutic applications as antimicrobial, antioxidant, anti-cancer agents and in dye degradation for water remediation.

Therapeutic Efficacy Of Plasma Activated Medium In 2d And 3d In Vitro Head And Neck Fadu Cancer Cell

Plasma Activated Media (PAM) has shown an increasing anticancer effect in the past few [1-3]. In in vitro, decrease in cell proliferation [2.4], DNA damage [2;5] and apoptosis [6] were observed. The main advantage of PAM is its possibility to be prepared in advance and it can be used several weeks after activation by plasma jet when it is stored at the right temperature [2;7]. The aim of this work is to investigate the inhibitory effect of PAM and hydrogen peroxide H2O2 on Head and Neck cancerous cells (FaDu). The response of FaDu cells in monolayer cultures and Multi Cellular Tumor Spheroids (MCTS) after treatment with different PAMs was compared. A homemade helium plasma jet was used to produce PAM. Helium plasma jet was generated using dielectric barrier discharge configuration. Helium was injected with flowmeter and the gas flow is fixed at 3L/min. One treatment with PAM induces cell detachment from MTCs since the first day in a PAM exposure dependent manner. This is due to the presence of H2O2 in PAM. However, a rapid spheroids regrowth is observed attributed to a resistance of FaDu cells to H2O2. After multiple treatments of MCTS with PAM we obtained an inhibition of cell growth. MCTS is brought out with a comparison of PAM effect on 2D versus MCTS. Inversely, PAM induces cell death in the case of 2D cell culture. This result underlines the importance of working with MCTS instead of 2D cells.

Study effect of crude alcoholic extract of Hawthorn (Crataegus Oxyacantha) and crude polyphenolic compounds from blackolive (Olea Europae) fruits on some physiological parameters of kidney of male rats treated with hydrogen peroxide

This study was carried out to investigate the protective role of 70% ethanolic alcohol extract of Hawthorn (crataegus oxyacantha ) and crude polyphenolic compounds of black olive fruits (oleae uropae) on some physiological functions of the male rats kidney treated with 1% hydrogen peroxide .Twenty mature male newzeland rats were divided randomly into four equal groups and treated for 30 days as follows:-control group which were given ordinary tap water , first treated group (G1) was given 1% H2O2 in drinking water , the second treated group (G2) was orally given alcoholic extract of Hawthorn 300 mg / kg B.W. with 1%hydrogen peroxide H2O2in drinking water , third treated group(G3) was given 200mg /kg B.W. of crude extract of black olive with 1% H2O2 . Blood samples were collected at zero time and 30 days of the experiment for measuring the following parameters: - concentration of uric acid,urea,creatinine and glucose. The results showed significant increased in the concentration of uric acid and glucose of the group treated with 1%hydrogen peroxide H2O2 (G1) and significant decrease in the concentration of uric acid, creatinine, glucose of treated groups G2and G3, also significant decrease in the concentration of urea of treated group (G3) as compared with control group. Histological study revealed that oral treatment with 1%H2O2 caused cell necrosis and vacuolar degeneration of renal epithelial cells. It is concluded that treatment with hawthorn and crude polyphenol showed no clear pathological lesions. The present study documented the deleterious effect of H2O2 and renoprotective effect of Hawthorn and black olive fruits

Structural Analysis of Prosthetic Coatings Elaborated by Electrochemical Deposition

In this study, phosphocalcic coatings on titanium alloy Ti6Al4V substrate are elaborated using Electrodeposition (ELD) by adding optimized amount of hydrogen peroxide H2O2 into the electrolyte. Structural analysis is performed by X Rays Diffraction and the data are treated using the RIETVELD method. The characterization of the coatings elaborated by ELD showed that the H2O2 amount variation has an influence on the morphology, the crystal size and the chemical composition (monophasic or biphasic) of the coatings.

Effect of migration on homogeneous redox electrocatalysis at rotating disk electrode

This work is devoted to the theoretical study of the effect of migration on homogeneous redox electrocatalysis of electrochemical reactions at the rotating disk electrode. The mathematical model involves the Nernst-Planck equations that take into account diffusion, migration, convection, homogeneous chemical reactions, and electroneutrality condition. For the convenience of solving and analyzing the results, the mathematical model was reduced to the dimensionless form. The numerical solution was performed by the finite volume method on the nonuniform grid. Based on the results of computational experiments, for the electrocatalytic reduction of hydrogen peroxide in the presence of ferric ions, three zones were observed in the plane of concentrations of H2O2–H2SO4. These zones differ in the nature of the limiting current: for H+ ions, Fe+2 ions, and hydrogen peroxide H2O2. The dependences of the limiting current on the concentrations of H2SO4 and H2O2 were determined with and without consideration of the ionic migration. It was found that the ionic migration may be ignored only in the cases that the concentration of H2SO4 is significantly higher than that of H2O2. It was shown that the strongest effect of ionic migration is reached on the boundaries between zones that differ in the nature of the limiting current.

Thermodynamic properties of dissociated steam

In connection with the development of hydrogen technologies and the generation of dissociated steam as a result of the oxidation of hydrogen in an oxygen environment, it became necessary to determine the calorific parameters of dissociated steam. In the existing tables, the caloric parameters of dissociated steam are presented at a reference temperature of 0 K. By contrast, the authors have developed tables of dissociated steam using a reference temperature of 0°C, within the pressure range 0.01–20.0 MPa and the temperature range 1250–4000 K, along with a system of equations for the industrial calculation of the properties of dissociated steam within the temperature range 1250–2300 K and pressure range 0.01–10.0 MPa, followed by a temperature range of 2200–3600 K. During the dissociation of steam, a mixture of eight components are formed including hydrogen H, oxygen O, radicals OH and HO2, molecules of hydrogen H2, oxygen O2, steam H2O, and hydrogen peroxide H2O2. All existing tables of the properties of dissociated steam are based on a mixture of six components: H2, O2, OH, H, O, and H2O. For evaluate whether this is an oversimplification, the composition of the mixture comprising all eight components was calculated, taking into account additional chemical reactions for the formation of HO2 and H2O2. At a pressure of 0.01 MPa, the maximum mole fraction of HO2 was 2.8·10−5 at a temperature of 3000 K, and at a pressure of 10 MPa, the maximum mole fraction was 5·10−5 at a temperature of 4000 K. The mole fraction of H2O2 was much lower. Thus at temperatures up to 3000 K, calculations of the properties of dissociated steam are restricted to six components.

Protective effects of orange (Citrus sinensis L.) peel aqueous extract and hesperidin on oxidative stress and peptic ulcer induced by alcohol in rat

BackgroundMassive alcohol drinking can lead to gastric ulcer. In the present study we investigated the gastroprotective effect of Citrus sinensis peel aqueous extract (CSPE) and Hesperidin (H) in ethanol (EtOH) induced oxidative stress and peptic ulcer in rats.MethodsSeventy adult male Wistar rats were divided into seven groups of 10 each: control, EtOH (4 g/kg b.w.), EtOH + various doses of CSPE (100, 200 and 400 mg/kg, b.w.), EtOH + Hesperidin (50 mg/kg, p.o.) and EtOH + Omeprazole (OM, 20 mg/kg, p.o.). Animals were perorally (p.o.) pre-treated with CSPE during 15 days and intoxicated with a single oral administration of EtOH (4 g/kg b.w.) during 2 h. Gastric ulcer was induced in rats with a single dose of ethanol (EtOH). Ulcer index, gene expression of gastric cyclooxygenase-2 (COX-2), tumor necrosis factor alpha (TNF-α), malondialdhyde (MDA), hydrogen peroxide H2O2 and Thiol groups (−SH) content in stomach and antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and gluthation peroxidise (GPx) were measured. Furthermore, histopathological examinations were performed.ResultsThe results showed that ethanol induced gastric damage, improving oxidative stress markers level such as MDA (121 ± 4.45 nmol/mg proteins) and H2O2 (24.62 ± 1.04 μmol/mg proteins), increased pro-inflammatory cytokine (TNF-α level), as well as the expression of COX-2 in the ethanol group. However, a significant depletion of enzymatic and non-enzymatic antioxidants were observed, such as, GPx (72%), SOD (57.5%), CAT (41.6%) and -SH (50%). The lesions were associated with severe histopathological damage. The both Citrus sinensis peel aqueous extract (CSPE) and hesperidin significantly protect against all gastric damages caused by ethanol administration in rats.ConclusionsWe propose that CSPE and hesperidin exhibit protective effects in EtOH-induced peptic ulcer in rat. This protection might be related in to part its antioxidant properties as well as its opposite effects on some studied intracellular mediators.

Thermo- and photo-oxidation reaction scheme in a treatment system using submerged plasma

Some of hazardous liquid organic wastes, radioactive or not, are waiting from outlet to be destroyed. The ELIPSE process is a new technology of organic liquid destruction, involving a thermal plasma working under a water column, which ensures the cooling, the filtration and the scrubbing of the gases coming from the degradation. This study deals with the ability of the ELIPSE process to destroy the pure organic liquids and then to reduce the amount of organic matter remaining in the aqueous solution by means of the thermal or radiative properties of plasma.Preliminary test have shown how efficient the process is for the destruction of the organic liquids when they are directly fed in the plasma hearth. Extensive researches have been performed to assess the ability of the submerged plasma to destroy the remaining organic matters either by reinjecting them with the aqueous solution into the plasma or by using the UV ray coming from the plasma itself. A comparison of the experimental results obtained with various mechanisms proposed by the work carried out highlighted that this UV radiation could, by excitation of water molecules, produce radicals OH which may either dimerise to produce hydrogen peroxide H2O2, or react with organic substances present. The calculation of an activation energy of 8.5±0.9kJmol−1 during the experiments shows that these radicals OH act directly after having been formed which explains a low H2O2 content stability when the solution contains organic compounds. Thus, this photo-oxidation taking place in the water column could be used to improve the destruction of residual organic matter in the solution by maintaining the plasma after processing a given amount of organic liquids.

Fast quantitative ROS detection based on dual-color single rare-earth nanoparticle imaging reveals signaling pathway kinetics in living cells.

Reactive oxygen species (ROS), and notably hydrogen peroxide H2O2, are cellular second messengers that are known to control a variety of signaling processes. They can finely regulate the dynamics of signal transduction, cell response and ultimately tissue function. However, there are very few local, quantitative and time-resolved descriptions of their cellular organization at the scale of molecular reactions, due to the lack of efficient sensors. We thus developed a novel nanoprobe-based ROS detection system using the simultaneous imaging of single lanthanide nanoparticles (YAG:Ce and chemically reduced Gd0.6Eu0.4VO4). We reveal that both particle luminescence signals are controlled by their H2O2 local environment. By simultaneously tracking their luminescence, we devised a new approach providing a quantitative (0.5 μM accuracy in the 1-10 μM range) H2O2 measurement with a 500 ms time resolution, surpassing all existing methods by two orders of magnitude, and revealing previously inaccessible molecular events controlling ROS concentration. We used this nanoprobe in living cells to track fast signaling pathways, by measuring the dynamics of H2O2 intracellular concentrations, induced by endothelin-1 (ET-1) stimulation. We thus revealed the mechanisms controlling ROS production, notably the activity modulation of the ROS-producing enzyme NADPH oxidase by fast (<10 s) EGFR transactivation, and measured quantitatively their kinetic parameters through a minimal analytical model. Altogether, these results illustrate how lanthanide nanoparticle-based sensors are a powerful tool to dynamically probe molecular mechanisms shaping the oxidative cell response.

Treatment trails of saprolegniosis in Oreochromis niloticus

This study was performed to compare between different methods of Saprolegnia treatment hydrogen peroxide H2O2, potassium permanganate KMnO4 and biological treatment non pathogenic bacterial strain Aeromonas hydrophila (NPAH). 120 Oreochromis niloticus were randomly collected and investigated for Saprolegnia fungal infection and infection rate were 10%, 5% and 15% in tolompate village, Elhamool and om-sin village respectively. Obtained Saprolegnia parasitica (S. parasitica) was examined by Polymerase chain reaction (PCR of ITS gene, 750 bp). Results obtained revealed that Kmno4 had the highest effective treatment in S. parasitica infection compared with biological and control treatment. Also, biological treatment with A. hydrophila showed hazourd of bacterial infection. So, KMnO4 recommended in case of S. parasitica infection as treatment of choice followed by H2O2 and a biological treatment with A. hydrophila is not recommended.

Inhibition of Horseradish Peroxidase Activity by Boroxine Derivative, Dipotassium-trioxohydroxytetrafluorotriborate K2[B3O3F4OH

Recently research shows that horseradish peroxidase, HRP, when combined with other compounds, is highly reactive toward different human tumour cells and that better understanding of catalytic mechanism and inhibition HPR could lead to a new targeted cancer therapy. Thus, the inhibition of HRP activity by dipotassium-trioxohydroxytetrafluorotriborate K2[B3O3F4OH] was investigated for possible explanation of previously observed antitumour activities of this promising drug. HRP activity was studied under steady-state kinetic conditions by a spectrophotometric method. In the absence of the inhibitor values of Km = 0.47 mM and Vmax = 0.34 mM min−1, respectively, were determined. The hydrogen peroxide H2O2 kinetic measurements show a competitive inhibition with the inhibition constant KI = 2.56 mM. The activation energy Ea values were found to be very similar for both reactions; in the absence of inhibitor activation energy was 17.7 kJ mol−1 and in the presence of inhibitor activation energy was 16.3 kJ mol−1. The values of Arrhenius constants were found to be different; A = 4.635 s−1 was measured in the absence of inhibitor while in the presence of inhibitor Arrhenius constant was 1.745 s−1 showing that K2[B3O3F4OH] initiates conformational change in the structure of the HRP and subsequently reduces its activity.

Hierarchically porous Pd/SiO2 catalyst by combination of miniemulsion polymerisation and sol-gel method for the direct synthesis of H2O2

The production of hydrogen peroxide H2O2, as an important commodity chemical, attires the attention towards greener processes such as the direct synthesis from hydrogen H2 and oxygen O2, the selectivity being the biggest challenge. Since this reaction is structure-sensitive, the design of appropriate catalysts is required. We propose a novel method to prepare hierarchically porous Pd/SiO2 catalyst by combination of miniemulsion polymerisation to prepare a Pd-containing latex template and sol-gel synthesis in controlled conditions to tailor the silica porosity. The final material displayed a surface area of 711m2g−1 and a total pore volume of 0.93cm3g−1. The catalyst was evaluated with different pre-treatments in the direct synthesis of H2O2, where it exhibited structural resistance at the reaction conditions and a stable selectivity of 46±1% towards H2O2.

A better understanding of Cbd-Zn(S,O) using hydrogen peroxide as an additive

This paper explores the influence of hydrogen peroxide H2O2 on the chemical bath deposition of zinc oxisulfide Zn(S,O) and the final photovoltaic performances of the Cu(In,Ga)Se2-based (CIGSe) associated device. First, the influence of H2O2 on Zn(S,O) deposition rate and growth mechanism is studied with theoretical considerations and in situ quartz crystal microgravimetry measurements. It shows that hydrogen peroxide concentration masters the deposition rate and induces a “cluster-by-cluster” mechanism. Morphology and composition of Zn(S,O) films have been investigated by scanning electron microscopy and X-Ray photoelectron spectroscopy techniques. In a second part the optimized process is then on co-evaporated Cu(In,Ga)Se2 substrates and solar cells are completed with a (Zn,Mg)O/ZnO:Al window layers. The use of H2O2 leads to lower efficiency than CdS-based reference, which can be explained by an oxidation of the CIGSe surface.

Improved Data Retention of InSnZnO Nonvolatile Memory by H2O2Treated Al2O3Tunneling Layer: A Cost-Effective Method

An experiential aspect regarding the improvement of retention characteristics of InSnZnO (ITZO) thin-film transistor-based nonvolatile memory (TFT-NVM) devices with a hydrogen peroxide H2O2 treated Aluminum oxide (Al2O3) tunneling layer is reported. A better performance in retention of $\sim 92$ % (after ten years), a smaller subthreshold swing of 96 mV/decade, and a higher field effect mobility of 31.08 cm2/ $\text {V}\cdot \text {s}$ were obtained in H2O2 treated TFT-NVM devices compared with untreated one. Furthermore, employing the H2O2treatment in the Al2O3 layer provided oxygen-rich (O/Al ratio = 1.45) and OH− residuals free Al2O3, which effectively minimized the interface states ( $1.34 \times 10^{11}$ cm $^{-2}$ eV $^{-1})$ between the ITZO/(Al2O3/SiO x /SiO2) stack through strong oxidation. These results suggest that high-quality Al2O3 dielectric layer can be obtained through cost-effective H2O2 oxidation techniques for TFT-NVM devices.

How to assess the plasma delivery of RONS into tissue fluid and tissue

The efficacy of helium (He) and argon (Ar) plasma jets are being investigated for different healthcare applications including wound and cancer therapy, sterilisation and surface disinfections. Current research points to a potential link between the generation of reactive oxygen and nitrogen species (RONS) and outcomes in a range of biological and medical applications. As new data accrue, further strengthening this link, it becomes important to understand the controlled delivery of RONS into solutions, tissue fluids and tissues. This paper investigates the use of He and Ar plasma jets to deliver three RONS (hydrogen peroxide—H2O2, nitrite— and nitrate—) and molecular oxygen (O2) directly into deionised (DI) water, or indirectly into DI water through an agarose target. The DI water is used in place of tissue fluid and the agarose target serves as a surrogate of tissue. Direct plasma jet treatments deliver more RONS and O2 than the through-agarose treatments for equivalent treatments times. The former only deliver RONS whilst the plasma jets are ignited; the latter continues to deliver RONS into the DI water long after the plasmas are extinguished. The He plasma jet is more effective at delivering H2O2 and directly into DI water, but the Ar plasma jet is more effective at nitrating the DI water in both direct and through-agarose treatments. DI water directly treated with the plasma jets is deoxygenated, with the He plasma jet purging more O2 than the Ar plasma jet. This effect is known as ‘sparging’. In contrast, for through-agarose treatments both jets oxygenated the DI water. These results indicate that in the context of direct and indirect plasma jet treatments of real tissue fluids and tissue, the choice of process gas (He or Ar) could have a profound effect on the concentrations of RONS and O2. Irrespective of operating gas, sparging of tissue fluid (in an open wound) for long prolonged periods during direct plasma jet treatment, could have implications for healthy tissue function; whilst through-tissue plasma jet treatment may provide a method to reperfuse oxygen-starved tissue. The assays described in this paper can be readily adopted (by others) and may support the future development of plasma sources to deliver specific (metered) doses of RONS.

Preparation and Characterization of Bimetallic Catalyst (NiO – CoO) for Desulfurization of Gas Oil

In this study NiO - CoO bimetallic catalysts are prepared with two Ni/Co ratios (70:30 and 80: 20) using the precipitation method of nitrate salts. The effects of Ni /Co ratio and preparation methods on the catalyst are analyzed by using different characterization techniques, i.e. atomic absorption (AA) , XRD, surface area and pore volume measurements according to the BET method . The results indicate that the best catalyst is the one containing the percentage of Ni :Co ( 70 : 30 ). Experiments indicate that the optimal conditions to prepare catalyst are stirring for three hours at a temperature of 60oC of the preparation , pH= (8-9) , calcination temperature at 400oC for two hours using the impregnation method . The catalyst activity is studied through the application in the process of oxidative desulfurization of gas oil fuel . The optimal conditions for deep oxidative desulfurization processes are : catalysts 3% , 2 gm. Na2 CO3 , refluxe time 3 hours at 400 C , using a mechanical stirrer at moderate speed (700 rpm), the volume ratio of gas oil : H2O2 : acetic acid is 10: 1: 0.5 and extracted with 1:1 ratio of acetonitrile to the gas oil for three times . The results indicate that the catalysts are efficient to remove sulfur from gas oil depending on temperature, time, concentration of hydrogen peroxide H2O2 30 % and solvent used for extraction. The efficiency of the best catalyst gives a maximum sulfur removal reaching 68.97%.