Titania nanotube (TNT) arrays fabricated by anodizing of titanium foil in organic (ethylene glycol) and inorganic (phosphoric acid) electrolytes and thermally modified in argon revealed much improved properties to detect hydrogen peroxide. Horseradish peroxidase and acetate thionine co-absorbed by a dip coating on the TNT electrode were used to detect hydrogen peroxide in phosphate buffered saline. The morphology and electrochemical properties of TNT arrays were studied by scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry. Well defined oxidation and reduction peaks for potassium ferricyanide have been observed for TNT formed in ethylene glycol and annealed in argon. TNT arrays formed in organic electrolyte and annealed in argon indicated more favorable adsorption and electrochemical properties what was confirmed by detection of hydrogen peroxide towards analyte in phosphorate buffered saline solution.

This paper proposes a new, simple and an efficient method for methanol formation under the cavitation influence of hydrogen-peroxide using a dynamic cavitation reactor. The process involves the reaction of the generated hydroxyl radical with propanebutane gas (C3–C4) to form propyl and butyl radicals which decompose into methyl radicals and alkenes, followed by the subsequent yield of methanol (via the interaction of methyl-radical with hydroxyl radical). Technological process parameters employed in this investigation are quite achievable for industrial production.

This paper presents an idea and results of 2D and 3D numerical CFD simulations of the proposed ring-engine construction dedicated for air propulsion or generation of electric power. The engine is designed as the simplest construction realizing the idea of pulsating reaction chamber utilizing a constant volume combustion principle. An atypical fuel (hydrogen peroxide) is used in the analyzed construction. The proposed ring-engine has reaction chambers forming a part of a ring periodically filled by cooling air and hydrogen peroxide vapour. The H2O2 is decomposed in exothermic reaction increasing pressure inside the chamber of constant volume. High pressure gas contents of the reaction chambers are periodically decompressed by jet nozzles generating torque. The paper contains the description of the ring-engine idea, the schematic engine geometry and a set of data visualizing pressure, velocity, temperature and species distribution inside the engine components being results of numerical simulations.

Bactericidal activity of caprylic acid (CA) and hydrogen peroxide (HP) was investigated in this study in order to design a suitable formulation for use in the food-processing industry. Antibacterial effects of the two chemicals were tested in vitro against the reference strains of Salmonella enterica subsp. enterica serotype Enteritidis CCM 4420, Escherichia coli CCM 3988, Listeria monocytogenes CCM 5578 and Staphylococcus aureus CCM 4223, as well as against the wild bacterial strains obtained from various food commodities (poultry meat, rabbit meat, raw milk sheep cheese ‘Bryndza’) and potable water. First, suspension test was carried out to determine the minimum bactericidal concentrations for individual chemical compounds. While most Gram-negative bacteria tested were effectively inhibited by HP at a 0.5% concentration, the growth of Gram-positive bacterial strains was stopped by a 2% solution. CA showed similar antibacterial effect on all bacterial strains tested except for Staph. aureus showing the same sus- ceptibility as Gram-negative bacteria. The wild strains generally had higher resistance to both chemicals than the reference strains. Combination of HP and CA at concentrations of 0.01%; 0.05% and 0.1% was further tested by the suspension test, carrier test, and carrier test with simul- taneous exposure to UV light. The total bactericidal activity against selected foodborne pathogens was already observed at a concentration of 0.1% and the efficiency was significantly increased by the use of UV radiation. A novel disinfectant based on the combination of HP with CA appears to be a suitable binary formulation for potential use in the food sector.

It is known that external diffusional resistances are significant in immobilized enzyme packed-bed reactors, especially at large scales. Thus, the external mass transfer effects were analyzed for hydrogen peroxide decomposition by immobilized Terminox Ultra catalase in a packed-bed bioreactor. For this purpose the apparent reaction rate constants, kP, were determined by conducting experimental works at different superficial velocities, U, and temperatures. To develop an external mass transfer model the correlation between the Colburn factor, JD, and the Reynolds number, Re, of the type JD = K Re(n-1) was assessed and related to the mass transfer coefficient, kmL. The values of K and n were calculated from the dependence (am kp-1 - kR-1) vs. Re-1 making use of the intrinsic reaction rate constants, kR, determined before. Based on statistical analysis it was found that the mass transfer correlation JD = 0.972 Re-0.368 predicts experimental data accurately. The proposed model would be useful for the design and optimization of industrial-scale reactors.

In this study defense responses in three potato varieties with different levels of reaction to the late blight disease caused by Phytophthora infestans were analyzed after inoculation with the pathogen. In the resistant cv. Pastusa Suprema, increased intensity of H2O2 and callose deposit accumulation was observed beginning at 24 hours after inoculation, followed by a hypersensitive response at the inoculation points. In the moderately resistant cv. Diacol-Monserrate, the same responses were observed as in the resistant variety, but with less intensity over time. For the susceptible cv. Diacol-Capiro, the responses observed occurred later than in the other two varieties, subsequent to the advance of the pathogen over extensive necrotic areas. These results suggest that early, intense peroxide and callose accumulation and a hypersensitive response are associated with the observed resistance of the cv. Pastusa Suprema and cv. Diacol-Monserrate to P. infestans.

In this study, we examined whether and to what extent oxidative stress is induced in seedlings of two winter triticale (Triticosecale Wittm.) varieties (susceptible Tornado and resistant Witon) in response to infestation by the cereal grain aphid (Sitobion avenae L.) and bird-cherry-oat aphid (Rhopalosiphum padi L.). We compared the level of hydrogen peroxide (H2O2) and lipid peroxidation products as well as markers of protein damage (protein-bound thiol and carbonyl groups). The studied parameters were measured at 6, 24, 48 and 96 h post-initial aphid infestation compared to the non-infested control seedlings. Our studies indicated that the cereal aphid feeding evoked oxidative stress in the triticale seedlings. Cereal aphid feeding increased the H2O2 level in triticale tissues, with maximum levels observed at 24 and 48 h post-infestation. Triticale infestation with aphids also increased lipid peroxidation products in triticale seedlings, with the maximal levels at 48 or 96 h post-infestation. Further, there was a reduction in protein thiol content and an increase in protein carbonyl content in the triticale seedlings after infestation with female aphids. Stronger triticale macromolecule damages were evoked by the oligophagous aphid R. padi. There was a more substantial protein thiol content reduction in the resistant Witon cultivar and higher accumulation of protein-bound carbonyls in the tissues of the susceptible Tornado cultivar. The changes were proportional to the aphid population and the time of aphid attack. These findings indicate that the defensive strategies against cereal aphid (S. avenae and R. padi) infestation were stimulated in triticale Tornado and Witon seedlings. Our results explain some aspects and broaden the current knowledge of regulatory mechanisms in plant-aphid interactions.

The performance of adsorbent synthesized by alkali activation of aluminosilicate precursor metakaolin with sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as well as the foaming agent was studied for copper ions adsorption from aqueous solution. This paper investigated the effect of adding hydrogen peroxide (H2O2) and aluminium powder as foaming agents to an alkali activated materials slurry. The experimental range included 0.50 wt%, 0.75 wt%, and 1.00 wt% hydrogen peroxide and 0.02 wt%, 0.04 wt%, and 0.06 wt% aluminium powder. A control sample without a foaming agent was also created for comparison. The specific surface area, water absorption, density, compressive strength and microstructure of metakaolin based alkali activated materials were evaluated. The adsorption capability of Cu2+ with addition of hydrogen peroxide and aluminium powder was then tested. Results indicate hydrogen peroxide addition had superior pore size distribution and homogeneous porosity than aluminium powder, implying improved copper ion elimination. Cu2+ adsorption capability reached 98% with 0.75 wt% hydrogen peroxide and 24.6076 m2/g surface area. The results demonstrating that low cost metakaolin-based AAMs are the most effective adsorbent for removing copper ions.

On the basis of hydrogen peroxide decomposition process occurring in the bioreactor with fixed-bed of commercial catalase the optimal feed temperature was determined. This feed temperature was obtained by maximizing the time-average substrate conversion under constant feed flow rate and temperature constraints. In calculations, convection-diffusion-reaction immobilized enzyme fixed-bed bioreactor described by a coupled mass and energy balances as well as general kinetic equation for rate of enzyme deactivation was taken into consideration. This model is based on kinetic, hydrodynamic and mass-transfer parameters estimated in earlier work. The simulation showed that in the biotransformation with thermal deactivation of catalase optimal feed temperature is only affected by kinetic parameters for enzyme deactivation and decreases with increasing value of activation energy for deactivation. When catalase undergoes parallel deactivation the optimal feed temperature is strongly dependent on hydrogen peroxide feed concentration, feed flow rate and diffusional resistances expressed by biocatalyst effectiveness factor. It has been shown that the more significant diffusional resistances and the higher hydrogen peroxide conversions, the higher the optimal feed temperature is expected.

Optimal feed temperature was determined for a non-isothermal fixed-bed reactor performing hydrogen peroxide decomposition by immobilized Terminox Ultra catalase. This feed temperature was obtained by maximizing the average substrate conversion under constant feed flow rate and temperature constraints. In calculations, convection-diffusion-reaction immobilized enzyme fixed-bed reactor described by a set of partial differential equations was taken into account. It was based on kinetic, hydrodynamic and mass transfer parameters previously obtained in the process of H2O2 decomposition. The simulation showed the optimal feed temperature to be strongly dependent on hydrogen peroxide concentration, feed flow rate and diffusional resistances expressed by biocatalyst effectiveness factor.