A closed system consisting of an assimilation chamber furnished with a membrane inlet from the liquid phase connected to a mass spectrometer was used to measure O(2) evolution and uptake by Chlamydomonas reinhardtii cells grown in ambient (0.034% CO(2)) or CO(2)-enriched (5% CO(2)) air. At pH = 6.9, 28 degrees C and concentrations of dissolved inorganic carbon (DIC) saturating for photosynthesi...

Mass-spectrometric disequilibrium analysis was applied to investigate CO2 uptake and HCO3 2 transport in cells and chloroplasts of the microalgae Dunaliella tertiolecta and Chlamydomonas reinhardtii, which were grown in air enriched with 5% (v/v) CO2 (high-Ci cells) or in ambient air (low-Ci cells). Highand low-Ci cells of both species had the capacity to transport CO2 and HCO3 , with maximum r...

We describe further development of a previous laboratory prototype pulsed cavity ring-down spectroscopy (CRDS) sensor into a field-deployable system for hightime-resolution, continuous, and automated measurement of gaseous elemental mercury (GEM) concentrations in ambient air. We employed an external, isotopically enriched Hg cell for automated locking and stabilization of the laser wavelength ...

Increased concentrations of CO2 and ozone are predicted to lower nutritional quality of leaves for insect herbivores, which may increase herbivory as insects eat more to meet their nutritional demands. To test this prediction, we measured levels of herbivory in soybean grown in ambient air and air enriched with CO2 or O3 using free air gas concentration enrichment (FACE). Under open-air conditi...

In this study, a 3D combustion chamber was simulated using FLUENT 6.32. Aims to obtain accurate information about the profile of the combustion in the furnace and also check the effect of oxygen enrichment on the combustion process. Oxygen enrichment is an effective way to reduce combustion pollutant. The flow rate of air to fuel ratio is varied as 1.3, 3.2 and 5.1 and the oxygen enriched flow ...

A stratified air mass enriched in methane (CH4) was sampled at ~600m to ~2000m altitude, between the north coast of Norway and Svalbard as part of the Methane in the Arctic: Measurements and Modelling campaign on board the UKˈs BAe-146-301 Atmospheric Research Aircraft. The approach used here, which combines interpretation of multiple tracers with transport modeling, enables better understandin...

We hypothesized that reductions in arterial PCO2 (PaCO2) below the apnea threshold play a key role in the pathogenesis of idiopathic central sleep apnea syndrome (ICSAS). If so, we reasoned that raising PaCO2 would abolish apneas in these patients. Accordingly, patients with ICSAS were studied overnight on four occasions during which the fraction of end-tidal CO2 and transcutaneous PCO2 were me...

Haploid tobacco (Nicotiana tabacum L.) cell cultures derived from quite different cultivars have been grown photoautotrophically in medium lacking sucrose and with 1.6 mum naphthaleneacetic acid and 1.5 mum isopentenylaminopurine. Cells were grown for 5 months on agar medium in Petri plates in air with dry weight increases of 1.5- to 3-fold per month. Callus cells were also grown photoautotroph...

A CFD-based numerical model has been developed for the determination of the volume concentration and number density of soot in a laminar diffusion flame of methane in air, under transient condition following ignition of the flame. The transience is studied from the point of ignition till the final steady state is reached. The burner is an axi-symmetric co-flowing one with the fuel issuing throu...

background: measuring and monitoring of air pollutants are one of environmental and all' pollution controls tools. due to lack of widespread data in iran, this study was performed to estimate the trends of major pollutant emissions to atmosphere in the uk from 1980 to 1996. methods: this investigation is a retrospective study that the data were collected from the departments of environment, tra...