An experimental lung model was used, with controlled ventilation, to determine the effect of different circle arrangements and varying ventilatory frequencies on the efficiency of carbon dioxide removal from a circle system without carbon dioxide absorption. Greater efficiency was found when fresh gas entered the system between the unidirectional inspiratory valve and the subject that when the ...

This study investigated the effects of four structurally different quaternary ammonium salts (QASs), i.e., tetrabutylammonium tetrafluoroborate [TBA][BF4], tetrahexylammonium tetrafluoroborate [THA][BF4], tetrabutylammonium hexafluorophosphate [TBA][PF6], and tetrahexylammonium hexafluorophosphate [THA][PF6], on the growth and development of three weed species: gallant soldier (Galinsoga parvif...

Plants undergoing heat and low-CO2 stresses emit large amounts of volatile isoprenoids compared with those in stress-free conditions. One hypothesis posits that the balance between reducing power availability and its use in carbon assimilation determines constitutive isoprenoid emission rates in plants and potentially even their maximum emission capacity under brief periods of stress. To test t...

Deep sea hydrothermal vents are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. ...

Enzyme efficiency was investigated in the lipase-catalyzed hydrolysis of canola oil in supercritical carbon dioxide (SCCO2). Immobilized lipase from Mucor miehie (Lipozyme IM) was used as the catalyst and the results showed that enzyme efficiency dropped at high pressures indicating a possible change in enzyme microstructure. Therefore, scanning electron microscopy (SEM) was used...

We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomas...

differential scanning calorimetry (dsc), temperature programmed desorption mass spectrometry (tpd-ms) and small angle neutron scattering (sans) were used to investigate co2 uptake by the wyodak coal. adsorption of carbon dioxide on wyodak coal was studied by dsc. the exotherms evident at low temperatures are associated with the uptake of co2 suggesting that carbon dioxide interacts strongly wit...

Simultaneous measurements of CO(2) and O(2) fluxes from wheat (Triticum aestivum) shoots indicated that short-term exposures to elevated CO(2) concentrations diverted photosynthetic reductant from NO(3)(-) or NO(2)(-) reduction to CO(2) fixation. With longer exposures to elevated CO(2), wheat leaves showed a diminished capacity for NO(3)(-) photoassimilation at any CO(2) concentration. Moreover...