Mechanistic details of CH4 oxidation were examined on PdO/ ZrO2 catalysts using isotopic tracer methods and measurements of kinetic isotope effects. Normal kinetic isotope effects were observed using CH4/O2 and CD4/O2 reactant mixtures. The (kH/kD) ratio was between 2.6 and 2.5, and it decreased slightly as the reaction temperature increased from 527 to 586 K. These kinetic isotope effects refl...

Oxygen depletion in the upper ocean is commonly associated with poor ventilation and storage of respired carbon, potentially linked to atmospheric CO2 levels. Iodine to calcium ratios (I/Ca) in recent planktonic foraminifera suggest that values less than ∼2.5 μmol mol(-1) indicate the presence of O2-depleted water. Here we apply this proxy to estimate past dissolved oxygen concentrations in the...

in the present research, effects of modified atmosphere packaging (map) includingthree gas combinations and two packaging films (low density polyethylene (ldpe) andpolypropylene (pp)) on postharvest quality and storage-life of 'elberta' peach wereevaluated. the study was conducted as a factorial experiment based on crd(completely randomized design) with three replicates for 9 weeks. f...

The effects of different concentrations of the hydroalcoholic extract of dried powdered leaves of Cichorium intybus L., on CCl4-induced hepatotoxicity in vivo in rats and CCl4-induced cytotoxicity in isolated rat hepatocytes were investigated. Rats received different concentrations of the extract by i.p. injection for 3 consecutive days before the injection of (3ml/kg) CCl4 (i.p.). Twenty four ...

BACKGROUND Effective O2 delivery and accurate end-tidal CO2 (ETCO2) sampling are essential features of nasal cannulae (NCs) in patients with compromised respiratory status. We studied 4 NC designs: bifurcated nasal prongs (NPs) with O2 delivery and CO2 sensing in both NPs (Hudson), separate O2/CO2 NPs (Salter), and CO2 sensing in NPs with cloud O2 delivery outside the NPs via multi vents (Oridi...

Poultry fillets were packaged under 6 different gas atmospheres (A: 15% Ar, 60% O2, 25% CO2; B: 15% N2, 60% O2, 25% CO2; C: 25% Ar, 45% O2, 30% CO2; D: 25% N2, 45% O2, 30% CO2; E: 82% Ar; 18% CO2; F: 82% N2, 18% CO2) and stored at 4°C. During storage, the growth of typical spoilage organisms (Brochothrix thermosphacta, Pseudomonas spp., Enterobacteriaceae, and Lactobacilli spp.) and total viabl...

We investigate the chemical stability of CO2-dominated atmospheres of desiccated M dwarf terrestrial exoplanets using a one-dimensional photochemical model. Around Sun-like stars, CO2 photolysis by Far-UV (FUV) radiation is balanced by recombination reactions that depend on water abundance. Planets orbiting M dwarf stars experience more FUV radiation, and could be depleted in water due to M dwa...

Sunflower (Helianthus annuus L.) and tobacco (Nicotiana tabacum L.) were grown in the laboratory and leaves were taken from field-grown birch trees (Betula pendula Roth). Chlorophyll fluorescence, CO2 uptake and O2 evolution were measured and electron transport rates were calculated, J(C) from the CO2 uptake rate considering ribulose-1,5-bisphosphate (RuBP) carboxylation and oxygenation, J(O) f...

in general, amount of sludge will definitely increase in near future and composting processes, optimum composting conditions and compost use as fertilizer and soil amendment will then be significant research topics. the present study was conducted for o2 parameter estimation by multiple regression and artificial neural networks methods. daily temperature, ch4, h2s, co2 and o2 measurements were ...