The carbon dioxide production rate assumption biases gastric emptying parameters in healthy adults

2013 ◽  
Vol 27 (4) ◽  
pp. 539-545
Author(s):  
Oonagh Markey ◽  
Amir Shafat
Keyword(s):  
Carbon Dioxide ◽  
Gastric Emptying ◽  
Production Rate ◽  
Carbon Dioxide Production ◽  
Healthy Adults ◽  
Carbon Dioxide Production Rate

Performance of Fuel Cell and Engine Based Cogeneration Systems in Heating and Cooling Applications

2004 ◽  
Author(s):  
Gregory J. Kowalski ◽  
Mansour Zenouzi
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cell ◽  
Production Rate ◽  
Thermal Load ◽  
Carbon Dioxide Production ◽  
Thermodynamic System ◽  
Order System ◽  
Environment Impact ◽  
Heating And Cooling ◽  
Carbon Dioxide Production Rate

A generalized thermodynamic model is developed to describe cooling, heating and power generating systems. This model is based on reversible power generation and refrigeration devices with practical, irreversible heat exchanger processes provides valuable information on a system’s performance and allows easy comparisons among different systems at different loading conditions. Using both the first and second laws as well as the carbon dioxide production rate allows one to make a first order system assessment on its energy usage and environment impact. The use of the exergy destruction rate and insuring that its behavior be consistent with that of the first law performance is a important to insure that the thermodynamic system boundaries are correctly and completely defined. The importance of the total thermal load to required power ratio (HLRP) as a scaling parameter is demonstrated. While the reported results confirmed that generalized trends are not possible identify, a number of trends for limited conditions have been identified. The results have shown that a combined vapor compression/absorption refrigeration has higher first law utilization factors and lower carbon dioxide production rate for system with higher refrigeration to total thermal load ratios for all HLRP values. Fuel cell based subsystems outperform engine based subsystems for systems with large refrigeration loads.

Treatment of air polluted with methanol vapours in biofilters with and without percolationThis article is one of a selection of papers published in this Special Issue on Biological Air Treatment.

2009 ◽  
Vol 36 (12) ◽  
pp. 1911-1918 ◽  
Author(s):  
Antonio Avalos Ramirez ◽  
Sandrine Bénard ◽  
Anne Giroir-Fendler ◽  
J. Peter Jones ◽  
Michèle Heitz
Keyword(s):  
Carbon Dioxide ◽  
Production Rate ◽  
Removal Efficiency ◽  
Nitrogen Concentration ◽  
Carbon Dioxide Production ◽  
Elimination Capacity ◽  
Biotrickling Filter ◽  
Filter Performance ◽  
Carbon Dioxide Production Rate ◽  
Maximum Elimination Capacity

Air polluted with methanol vapours was treated in a biofilter and a biotrickling filter, both packed with inert materials. The effects of the nitrogen concentration present in the nutrient solution, the empty bed residence time, and the methanol inlet load, on the biofilter and biotrickling filter performance were all examined and compared. The elimination capacity, the biomass and the carbon dioxide production rates all increased with the increase of the parameters tested. The maximum elimination capacity for the biotrickling filter was 240 g·m–3·h–1 with corresponding removal efficiency of 75% and carbon dioxide production rate of 10 g·m–3·h–1, whereas the maximum elimination capacity for the biofilter was 80 g·m–3·h–1 with corresponding removal efficiency of 35% and carbon dioxide production rate of 70 g·m–3·h–1. The biomass production rate was similar for both the biofilter and the biotrickling filter. The carbon dioxide production rate was higher by a factor of 2 to 9 for the biofilter compared to the biotrickling filter.

scholarly journals Genetic variance and covariance components for carbon dioxide production and postweaning traits in Angus cattle

2020 ◽  
Vol 98 (9) ◽  
Author(s):  
Kath A Donoghue ◽  
Tracie Bird-Gardiner ◽  
Robert M Herd ◽  
Roger S Hegarty ◽  
Paul F Arthur
Keyword(s):  
Carbon Dioxide ◽  
Production Rate ◽  
Genetic Relationships ◽  
Carbon Dioxide Production ◽  
Strongly Correlated ◽  
Respiration Chamber ◽  
Angus Cattle ◽  
Methane Production Rate ◽  
Carbon Dioxide Production Rate ◽  
Variance And Covariance Components

Abstract This experiment investigated phenotypic and genetic relationships between carbon dioxide production, methane emission, feed intake, and postweaning traits in Angus cattle. Respiration chamber data on 1096 young bulls and heifers from 2 performance recording research herds of Angus cattle were analyzed to provide phenotypic and genetic parameters for carbon dioxide production rate (CPR; n = 425, mean 3,010 ± SD 589 g/d) and methane production rate (MPR; n = 1,096, mean 132.8 ± SD 25.2 g/d) and their relationships with dry matter intake (DMI; n = 1,096, mean 6.15 ± SD 1.33 kg/d), body weight (BW) and body composition traits. Heritability estimates were moderate to high for CPR (0.53 [SE 0.17]), MPR (0.31 [SE 0.07]), DMI (0.49 [SE 0.08]), yearling BW (0.46 [SE 0.08]), and scanned rib fat depth (0.42 [SE 0.07]). There was a strong phenotypic (0.83 [SE 0.02]) and genetic (0.75 [SE 0.10]) correlation between CPR and MPR. The correlations obtained for DMI with CPR and with MPR were high, both phenotypically (rp) and genetically (rg) (rp: 0.85 [SE 0.01] and 0.71 [SE 0.02]; rg (0.95 [SE 0.03] and 0.83 [SE 0.05], respectively). Yearling BW was strongly correlated phenotypically (rp ≥ 0.60) and genetically (rg > 0.80) with CPR, MPR, and DMI, whereas scanned rib fat was weakly correlated phenotypically (rp < 0.20) and genetically (rg ≤ 0.20) with CPR, MPR, and DMI. The strong correlation between both CPR and MPR with DMI confirms their potential use as proxies for DMI in situations where direct DMI recording is not possible such as on pasture.

Selection of Distributed Power-Generating Systems Based on Electric, Heating, and Cooling Loads

2006 ◽  
Vol 128 (3) ◽  
pp. 168-178 ◽  
Author(s):  
Gregory J. Kowalski ◽  
Mansour Zenouzi
Keyword(s):  
Carbon Dioxide ◽  
Production Rate ◽  
Thermal Load ◽  
Electric Heating ◽  
Carbon Dioxide Production ◽  
Thermodynamic System ◽  
Order System ◽  
Environment Impact ◽  
Heating And Cooling ◽  
Carbon Dioxide Production Rate

A generalized thermodynamic model is developed to describe combined cooling, heating, and power generating systems. This model is based on reversible power generation and refrigeration devices with practical, irreversible heat exchanger processes. It provides information on a system’s performance and allows easy comparisons among different systems at different loading conditions. Using both the first and second laws as well as the carbon dioxide production rate allows one to make a first-order system assessment of its energy usage and environment impact. The consistency of the exergy destruction rate and the first law performance ensures that the thermodynamic system boundaries are correctly and completely defined. The importance of the total thermal load to the required power ratio (HLRP) as a scaling parameter is demonstrated. A number of trends for limited conditions can be delineated even though the reported results confirmed that generalized trends are not identifiable because of the systems’ complexities. The results demonstrate that the combined vapor compression∕absorption refrigeration has higher first law utilization factors and lower carbon dioxide production rate for systems with high refrigeration to total thermal load ratios for all HLRP values. Fuel cell systems outperform engine systems for large refrigeration load applications. An illustration of combining these results to an economic analysis is presented.

Proxies to adjust methane production rate of beef cattle when the quantity of feed consumed is unknown

2016 ◽  
Vol 56 (3) ◽  
pp. 231 ◽  
Author(s):  
R. M. Herd ◽  
J. I. Velazco ◽  
P. F. Arthur ◽  
R. S. Hegarty
Keyword(s):  
Carbon Dioxide ◽  
Production Rate ◽  
Methane Production ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Test Results ◽  
Ch4 Production ◽  
Time Period ◽  
Methane Production Rate ◽  
Carbon Dioxide Production Rate

The aim of the present experiment was to evaluate the utility of carbon dioxide production rate (CPR; g CO2/day) and animal weight (WT) data as proxies for feed intake to adjust methane production rate (MPR; g CH4/day) in situations where dry-matter intake (DMI) is not known. This experiment measured individual-animal DMI, MPR and CPR in the feedlot, and then again on restricted quantities of grain and roughage diets in open-circuit respiration chambers. Of the 59 cattle tested in the feedlot, 41 had MPR and CPR recorded, and 59 and 57 had test results on the restricted grain and roughage rations. Methane production relative to DMI by individual animals was calculated as CH4 yield (MY; MPR/DMI) and as residual CH4 production (RMPDMI; calculated as MPR less predicted MPR based on DMI). A second form of RMP: RMPCO2, was calculated by regressing MPR against CPR to determine whether animals were producing more or less CH4 than predicted for their CPR. Carbon dioxide production rate was positively associated with DMI in all three test phases (R2 = 0.25, 0.45 and 0.47; all P < 0.001). The associations for MY with MPR : CPR were moderate and positive, as follows: R2 = 0.49 in the feedlot test; R2 = 0.37 in the restricted-grain test; and R2 = 0.59 in the restricted-roughage test, and with RMPCO2, values of R2 were 0.57, 0.34 and 0.59 in the three test phases (all P < 0.001). The R2 for RMPDMI with MPR : CPR in all three tests were 0.50, 0.79 and 0.69, and with RMPCO2, values of R2 were 0.68, 0.79 and 0.68 (all P < 0.001). The high R2 for MY with MPR : CPR and RMPCO2 and even higher R2 for RMPDMI with MPR : CPR and RMPCO2 in all three test phases showed that CPR can be used to adjust MPR data for DMI when DMI is not recorded. In the feedlot test, where animal WT data were recorded over 70 days, MPR adjusted for WT and WT gain had R2 with MY and RMPDMI of 0.60 and 0.83, respectively (P < 0.001), offering the possibility that animal WT data determined over an extended time period could also be used as a proxy for DMI in adjustment of MPR.

Measurement of Carbon Dioxide Production Rate in Sick Ventilated Premature Infants

Neonatology ◽  
1987 ◽  
Vol 51 (3) ◽  
pp. 138-143 ◽  
Author(s):  
A. Lucas ◽  
V. Nohria ◽  
S.B. Roberts
Keyword(s):  
Carbon Dioxide ◽  
Production Rate ◽  
Premature Infants ◽  
Carbon Dioxide Production ◽  
Carbon Dioxide Production Rate

Isotope method for the measurement of carbon dioxide production rate in man

1985 ◽  
Vol 41 (3) ◽  
pp. 659-661 ◽  
Author(s):  
W A Coward ◽  
A M Prentice
Keyword(s):  
Carbon Dioxide ◽  
Production Rate ◽  
Carbon Dioxide Production ◽  
Isotope Method ◽  
Carbon Dioxide Production Rate
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