Oxygen seasonality

Many reformulated gasolines use oxygenated compounds as additives. Clean Air regulations specify the need for oxygenated fuel in 39 metropolitan areas with high carbon monoxide concentrations. The regulations for oxygenated fuel are seasonal ... 

The composition given in Table 2.8 is global and, for most components, is reasonably constant for all locations, but the water vapour content will obviously vary according to the climatic region, season of the year, time of the day, etc. However, only oxygen, carbon dioxide and water vapour need to be considered in the context of atmospheric corrosion. 

Variability of Seawater Vertical sections through seawater showing the distribution of temperature, salinity, and oxygen for the Pacific Ocean and Western Atlantic Ocean are shown in Figures 21.3 and 21.4. The global variability of natural seawater and its effects on corrosion have been reviewed in particular with respect to seasonal variation of temperature, salinity, oxygen and pH in the Pacific surface water. Data is also given on... 

Atmospheric exposure trials, carried out in Cambridge, established the fact that when rusty specimens were painted in the summer, their condition, after some years exposure, was very much better than that of similar specimens painted in the winter It was found that steel weathered in Cambridge carried spots of ferrous sulphate, deeply imbedded in the rust, and that the quantity of ferrous sulphate/unit area was very much greater in the winter than in the summer this seasonal variation was attributed to the increased sulphur dioxide pollution of the atmosphere in the winter, caused by the combustion of coal in open grates. It was concluded that there was a causal relationship between the quantity of ferrous sulphate and the effective life of the paint. It was suggested that these soluble deposits of ferrous sulphate short-circuit the resistance of the paint film and, since paint films are very permeable to water and oxygen, the ferrous sulphate will become oxidised and hydrolysed with the production of voluminous rust, which will rupture the film at numerous points, thus giving rise to the characteristic type of failure seen on painted rusty surfaces. 

The oxygen atom produced in this step can react with oxygen molecules to produce more ozone, and so the ozone concentration in the stratosphere normally remains constant, with seasonal variations. Because the decomposition of ozone... 

Fig. 10-15 Organic carbon fluxes with depth in the water column normalized to mean annual primary production rates at the sites of sediment trap deployment. The undulating line indicates the base of the euphotic zone the horizontal error bars reflect variations in mean annual productivity as well as replicate flux measurements during the same season or over several seasons vertical error bars are depth ranges of several sediment trap deployments and uncertainities in the exact depth location. (Reproduced with permission from E. Suess (1980). Particulate organic carbon flux in the oceans - surface productivity and oxygen utilization, Nature 288 260-263, Macmillan Magazines.)...

Variability in herbivore tooth oxygen isotope compositions reflections of seasonality... 

Kirsanow K., Makarewicz, C., Tuross, N. (2008). Stable oxygen (8i 0) and hydrogen (8D) isotopes in ovicaprid dentinal collagen record seasonal variation. Journal of Archaeological Science Vol. 35, No. 12, pp. 3159-3167. 

Prolonged seasoning of the adsorbent in triplet oxygen leads to loss of the adsorbent s activity relative to the adsorption of 02( A ). This... 

Metal removal in SSFCWs has been recently focused on metal elimination from synthetic water and different wastewaters,66-86 on the evaluation of the effects of season, temperature, plant species, and chemical oxygen demand (COD) loading on metals removal,87 and on the accumulation of metals in wetland plant species and sediments.88-89 Recent reviews on heavy metal phytoremediation wetlands are also available.48... 

Shackleton, N. J. (1973), Oxygen isotope analysis as a means of determining season of occupation of prehistoric hidden sights, Archaeometry 15,133-141. 

Sea Salts - Most of the Na and Cl in both Greenland and Antarctica is of marine origin [1,13,21]. Near the ocean, sea salts may also account for most of the Mg, K, Ca, and S042-. Concentrations of Na and Cl display a maximum in winter Greenland precipitation which is coincident with the minimum oxygen isotope delta values [1,13,18]. The seasonal maximum in sea salt concentrations may be due to increased storminess, over the ocean in winter or to an increased poleward latent heat flux during the polar night [13]. 

Season of collection (Fowler and Oregioni 1976 Sanders etal. 1991) and latitude (Anderlini 1974) also influenced silver accumulations. Seasonal variations in silver concentrations of Baltic clams (Macoma balthica) were associated with seasonal variations in soft tissue weight and frequently reflected the silver content in the sediments (Cain and Luoma 1990). Oysters from the Gulf of Mexico vary considerably in whole-body concentrations of silver and other trace metals. Variables that modify silver concentrations in oyster tissues include the age, size, sex, reproductive stage, general health, and metabolism of the animal water temperature, salinity, dissolved oxygen,... 

Carbonates deposited in freshwater lakes exhibit a wide range in isotopic composition, depending upon the isotopic composition of the rainfall in the catchment area, its amount and seasonality, the temperature, the rate of evaporation, the relative humidity, and the biological productivity. Lake carbonates typically consist of a matrix of discrete components, such as detrital components, authigenic precipitates, neritic, and benthic organisms. The separate analysis of such components has the potential to permit investigation of the entire water column. For example, the oxygen isotopic... 

Fricke HC, Wickham SM, O Neil JR (1992) Oxygen and hydrogen isotope evidence for meteoric water infiltration during mylonitization and uphft in the Ruby Mountains - East Humboldt Range core complex, Nevada. Contr Miner Petrol 111 203-221 Fricke HC, Clyde WC, O Neil JR (1998a) Intra-tooth variations in 5 0 (PO4) of mammalian tooth enamel as a record of seasonal variations in continental climate variables. Geochim Cosmochim Acta 62 1839-1850... 

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