scholarly journals Ventilatory response to high inspired carbon dioxide concentrations in anesthetized dogs

2011 ◽  
pp. 63-69 ◽  
Author(s):  
Jack Loeppky ◽  
Ray Risling
Keyword(s):  
Carbon Dioxide ◽  
Ventilatory Response ◽  
Carbon Dioxide Concentrations ◽  
Anesthetized Dogs

Ventilatory response to fixed acid evaluated by ‘iso-Pco2’ technique

1959 ◽  
Vol 14 (4) ◽  
pp. 557-561 ◽  
Author(s):  
Dario B. Domizi ◽  
John F. Perkins ◽  
Joan S. Byrne
Keyword(s):  
Carbon Dioxide ◽  
Ventilatory Response ◽  
Carbon Dioxide Tension ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Control Value ◽  
Anesthetized Dogs ◽  
Increased Sensitivity ◽  
Small Increments ◽  
Fixed Acid

In order to avoid changes in a second stimulus to ventilation, i.e. carbon dioxide, while measuring the response to fixed acid, a technique was utilized whereby alveolar carbon dioxide tension (PaCOCO2) could be held constant. This technique includes continuous recording of PaCOCO2 with an infrared type analyzer and addition of sufficient CO2 to the inspired air to keep PaCOCO2 at its control value (near 40 mm Hg). The response of anesthetized dogs to infusion of 0.5 m HCl was measured when the PaCOCO2 was held at the control value and also at various other levels. Other experiments measured the effect of CO2 when it was not allowed to change arterial hydrogen ion concentration [H+]. It was found that both these substances are potent respiratory stimuli and that their effects may be considered essentially separate and additive, as suggested by Gray. The experiments also demonstrated a slightly increased sensitivity to CO2 at increased arterial [H+], but this effect was not found necessary to explain the response to acid. Responses to successive small increments in PaCOCO2 failed to reveal any ‘threshold,’ even with CO2 tensions as low as 15 mm during acidosis. Submitted on December 29, 1958

scholarly journals Snowfall-albedo feedbacks could have led to deglaciation of snowball Earth starting from mid-latitudes

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Philipp de Vrese ◽  
Tobias Stacke ◽  
Jeremy Caves Rugenstein ◽  
Jason Goodman ◽  
Victor Brovkin
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Climate Models ◽  
Hydrological Cycle ◽  
High Surface ◽  
Dust Deposition ◽  
Carbon Dioxide Concentrations ◽  
Maximum Temperatures ◽  
Carbon Dioxide Levels ◽  
Earth’S Climate

AbstractSimple and complex climate models suggest a hard snowball – a completely ice-covered planet – is one of the steady-states of Earth’s climate. However, a seemingly insurmountable challenge to the hard-snowball hypothesis lies in the difficulty in explaining how the planet could have exited the glaciated state within a realistic range of atmospheric carbon dioxide concentrations. Here, we use simulations with the Earth system model MPI-ESM to demonstrate that terminal deglaciation could have been triggered by high dust deposition fluxes. In these simulations, deglaciation is not initiated in the tropics, where a strong hydrological cycle constantly regenerates fresh snow at the surface, which limits the dust accumulation and snow aging, resulting in a high surface albedo. Instead, comparatively low precipitation rates in the mid-latitudes in combination with high maximum temperatures facilitate lower albedos and snow dynamics that – for extreme dust fluxes – trigger deglaciation even at present-day carbon dioxide levels.

Carbon Capture and the Aluminium Industry: Preliminary Studies

2006 ◽  
Vol 3 (4) ◽  
pp. 297 ◽  
Author(s):  
Graham Jones ◽  
Gargi Joshi ◽  
Malcolm Clark ◽  
David McConchie
Keyword(s):  
Carbon Dioxide ◽  
Red Mud ◽  
Carbon Capture ◽  
Total Alkalinity ◽  
Industrial Processes ◽  
Carbonate Alkalinity ◽  
General Acceptance ◽  
Maximum Value ◽  
Carbon Dioxide Concentrations ◽  
Bicarbonate Alkalinity

Environmental Context. Carbon dioxide concentrations in the atmosphere are rising every year by 1.5–3.0 ppm and there is now a general acceptance that increased efforts must be made to reduce industrial sources of this greenhouse gas. Carbonation of red mud wastes produced by aluminium refineries has been carried out to study the capacity of these wastes to capture carbon dioxide. Removal is very rapid, with the added carbon dioxide recorded as a large increase in bicarbonate alkalinity. Although these results can only be considered preliminary, the experiments indicate that these wastes can potentially remove up to 15 million tonnes of carbon dioxide produced in Australia per annum. Furthermore, the carbonated waste can be used in other industrial processes to add further value to these waste materials. Abstract. Carbonation of raw red mud produced by aluminium refineries and a chemically and physically neutralized red mud (Bauxsol™) has been carried out to study the capacity of these wastes to capture carbon dioxide. After only 5 min of carbonation of raw red mud, total alkalinity dropped 85%. Hydroxide alkalinity was almost totally consumed, carbonate alkalinity dropped by 88%, and bicarbonate alkalinity increased to 728 mg L–1. After 24 min carbonation, the bicarbonate alkalinity reached its maximum value of 2377 mg L–1, and hydroxide and carbonate alkalinity were virtually absent. After 30 and 60 min carbonation, bicarbonate alkalinity started to decrease slightly as the pH of the slurry increased. After 5 min carbonation of Bauxsol™, total and bicarbonate alkalinity dropped 89% and 9%, respectively. After 20 min carbonation, bicarbonate alkalinity dropped another 11%, but after 30 min carbonation bicarbonate alkalinity increased 26% to levels found in the original Bauxsol material, and pH was stable. Based on these experiments, a calculation of the amount of carbon dioxide that could be removed annually at aluminium refineries in Australia is potentially 15 million tonnes, and suggests that further studies are necessary to maximize this carbon removal process. Furthermore, carbonation produces a product, which can potentially be used in other industrial and agricultural activities to remove toxic metals and nutrients.

Effect of prolonged exposure of rats to high carbon dioxide concentrations

1978 ◽  
Vol 86 (3) ◽  
pp. 1149-1151
Author(s):  
P. M. Gramenitskii ◽  
V. A. Galichii ◽  
N. V. Petrova ◽  
N. Yu. Leont'eva
Keyword(s):  
Carbon Dioxide ◽  
Prolonged Exposure ◽  
High Carbon ◽  
Carbon Dioxide Concentrations ◽  
High Carbon Dioxide

Elevated air carbon dioxide concentrations increase dissolved carbon leaching from a cropland soil

2011 ◽  
Vol 108 (1-3) ◽  
pp. 135-148 ◽  
Author(s):  
Jan Siemens ◽  
Andreas Pacholski ◽  
Katia Heiduk ◽  
Anette Giesemann ◽  
Ulrike Schulte ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Dissolved Carbon ◽  
Carbon Dioxide Concentrations

scholarly journals VENTILATORY RESPONSE TO CARBON DIOXIDE DURING EXTRADURAL ANAESTHESIA WITH LIGNOCAINE AND FENTANYL

1989 ◽  
Vol 63 (1) ◽  
pp. 97-102 ◽  
Author(s):  
P. MORISOT ◽  
J.F. DESSANGES ◽  
J. REGNARD ◽  
A. LOCKHART
Keyword(s):  
Carbon Dioxide ◽  
Ventilatory Response

Why does the climate response to greenhouse warming and greenhouse cooling differ? 

2021 ◽  
Author(s):  
Jennifer Kay ◽  
Jason Chalmers
Keyword(s):  
Carbon Dioxide ◽  
Radiative Forcing ◽  
Climate Model ◽  
Temperature Response ◽  
Greenhouse Warming ◽  
Climate Response ◽  
Cloud Feedbacks ◽  
Surface Climate ◽  
Carbon Dioxide Concentrations ◽  
Radiative Feedbacks

<p>While the long-standing quest to constrain equilibrium climate sensitivity has resulted in intense scrutiny of the processes controlling idealized greenhouse warming, the processes controlling idealized greenhouse cooling have received less attention. Here, differences in the climate response to increased and decreased carbon dioxide concentrations are assessed in state-of-the-art fully coupled climate model experiments. One hundred and fifty years after an imposed instantaneous forcing change, surface global warming from a carbon dioxide doubling (abrupt-2xCO2, 2.43 K) is larger than the surface global cooling from a carbon dioxide halving (abrupt-0p5xCO2, 1.97 K). Both forcing and feedback differences explain these climate response differences. Multiple approaches show the radiative forcing for a carbon dioxide doubling is ~10% larger than for a carbon dioxide halving. In addition, radiative feedbacks are less negative in the doubling experiments than in the halving experiments. Specifically, less negative tropical shortwave cloud feedbacks and more positive subtropical cloud feedbacks lead to more greenhouse 2xCO2 warming than 0.5xCO2 greenhouse cooling. Motivated to directly isolate the influence of cloud feedbacks on these experiments, additional abrupt-2xCO2 and abrupt-0p5xCO2 experiments with disabled cloud-climate feedbacks were run. Comparison of these “cloud-locked” simulations with the original “cloud active” simulations shows cloud feedbacks help explain the nonlinear global surface temperature response to greenhouse warming and greenhouse cooling. Overall, these results demonstrate that both radiative forcing and radiative feedbacks are needed to explain differences in the surface climate response to increased and decreased carbon dioxide concentrations.</p>

Sign in / Sign up

Export Citation Format

Share Document