scholarly journals Sensitivity analysis to study the effects of temperature, carbon dioxide and solar radiation on sunflower under middle Gujarat Agro climatic region

2021 ◽  
Vol 23 (1) ◽  
pp. 141-143
Author(s):  
M.G. JADHAV ◽  
M.M. LUNAGARIA ◽  
D.D. PATIL ◽  
H.R. PATEL
Keyword(s):  
Carbon Dioxide ◽  
Sensitivity Analysis ◽  
Solar Radiation ◽  
Climatic Region ◽  
Effects Of Temperature

scholarly journals Value of variation of end-tidal carbon dioxide for predicting fluid responsiveness during the passive leg raising test in patients with mechanical ventilation: a systematic review and meta-analysis

Critical Care ◽  
2022 ◽  
Vol 26 (1) ◽  
Author(s):  
Haijun Huang ◽  
Chenxia Wu ◽  
Qinkang Shen ◽  
Yixin Fang ◽  
Hua Xu
Keyword(s):  
Carbon Dioxide ◽  
Mechanical Ventilation ◽  
Sensitivity Analysis ◽  
Fluid Responsiveness ◽  
Meta Analysis ◽  
End Tidal Carbon Dioxide ◽  
Study Heterogeneity ◽  
Meta Regression ◽  
Meta Regression Analysis ◽  
End Tidal

Abstract Background The ability of end-tidal carbon dioxide (ΔEtCO2) for predicting fluid responsiveness has been extensively studied with conflicting results. This meta-analysis aimed to explore the value of ΔEtCO2 for predicting fluid responsiveness during the passive leg raising (PLR) test in patients with mechanical ventilation. Methods PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched up to November 2021. The diagnostic odds ratio (DOR), sensitivity, and specificity were calculated. The summary receiver operating characteristic curve was estimated, and the area under the curve (AUROC) was calculated. Q test and I2 statistics were used for study heterogeneity and publication bias was assessed by Deeks’ funnel plot asymmetry test. We performed meta-regression analysis for heterogeneity exploration and sensitivity analysis for the publication bias. Results Overall, six studies including 298 patients were included in this review, of whom 149 (50%) were fluid responsive. The cutoff values of ΔEtCO2 in four studies was 5%, one was 5.8% and the other one was an absolute increase 2 mmHg. Heterogeneity between studies was assessed with an overall Q = 4.098, I2 = 51%, and P = 0.064. The pooled sensitivity and specificity for the overall population were 0.79 (95% CI 0.72–0.85) and 0.90 (95% CI 0.77–0.96), respectively. The DOR was 35 (95% CI 12–107). The pooled AUROC was 0.81 (95% CI 0.77–0.84). On meta-regression analysis, the number of patients was sources of heterogeneity. The sensitivity analysis showed that the pooled DOR ranged from 21 to 140 and the pooled AUC ranged from 0.92 to 0.96 when one study was omitted. Conclusions Though the limited number of studies included and study heterogeneity, our meta-analysis confirmed that the ΔEtCO2 performed moderately in predicting fluid responsiveness during the PLR test in patients with mechanical ventilation.

scholarly journals Value of Variation of End-Tidal Carbon Dioxide for Predicting Fluid Responsiveness During the Passive Leg Raising Test in Patients with Mechanical Ventilation: A Systematic Review and Meta-Analysis

2021 ◽  
Author(s):  
Haijun Huang ◽  
Chenxia Wu ◽  
Qinkang Shen ◽  
Yixin Fang ◽  
Hua Xu
Keyword(s):  
Carbon Dioxide ◽  
Mechanical Ventilation ◽  
Sensitivity Analysis ◽  
Regression Analysis ◽  
Fluid Responsiveness ◽  
Meta Analysis ◽  
End Tidal Carbon Dioxide ◽  
Meta Regression ◽  
Meta Regression Analysis ◽  
End Tidal

Abstract Background: The variation of end-tidal carbon dioxide(ΔEtCO2) has have been extensively studied with respect to its value in predicting fluid responsiveness, but the results are conflicting. This meta-analysis aimed to explore the value of ΔEtCO2 for predicting fluid responsiveness during the passive leg raising(PLR) test in patients with mechanical ventilation. Methods: PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched up to November 2021. The diagnostic odds ratio (DOR), sensitivity, and specificity were calculated. The summary receiver operating characteristic curve was estimated, and the area under the curve (AUROC) was calculated. We performed meta-regression analysis for heterogeneity exploration and sensitivity analysis for the publication bias.Results: Overall, 298 patients were included in this review, of whom 149 (50%) were fluid responsive. The cutoff values of ΔEtCO2 varied across studies, ranging from 5% to 5.8% or absolute increase 2mmHg. Heterogeneity between studies was assessed with an overall Q = 4.098, I2 = 51%, and P = 0.064. The pooled sensitivity and specificity for the overall population were 0.79 (95% CI: 0.72–0.85) and 0.90 (95% CI: 0.77–0.96), respectively. The DOR was 35 (95% CI: 12–107) (Fig. 4). The pooled AUROC was 0.81 (95% CI: 0.77–0.84). On meta-regression analysis, the number of patients was sources of heterogeneity. The sensitivity analysis showed that the pooled DOR ranged from 21 to 140 and the pooled AUC ranged from 0.92 to 0.96 when one study was omitted.Conclusions: This study was the first meta-analysis to evaluate the diagnostic accuracy of ΔEtCO2 in predicting fluid responsiveness during PLR test in patients with mechanical ventilation. This study confirmed that the ΔEtCO2 performed well in predicting fluid responsiveness in patients with mechanical ventilation.

scholarly journals Ventilated Double Window for the Preheating of the Ventilation Air Comparison of Its Performance in a Northern and a Southern European Climate

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Jorge S. Carlos ◽  
Helena Corvacho
Keyword(s):  
Sensitivity Analysis ◽  
Solar Radiation ◽  
Indoor Air ◽  
Climatic Data ◽  
Relevant Factor ◽  
Outdoor Air ◽  
Cold Winter ◽  
Passive System ◽  
Reference Levels ◽  
European Climate

Keeping the indoor air quality within the reference levels requires that the polluted indoor air be replaced by fresh air coming from the outside. This paper presents a sensitivity analysis and a series of simulations where the performance of this passive system is studied. The influence of each relevant factor, like the wind, the solar radiation, and the outdoor air temperature, is assessed. Two different local sets of climatic data were chosen, a mild and a cold winter.

Effects of temperature on the morphology and photosynthetic activity of newly matured leaves of alfalfa

1973 ◽  
Vol 51 (10) ◽  
pp. 1907-1916 ◽  
Author(s):  
S. B. Ku ◽  
L. A. Hunt
Keyword(s):  
Carbon Dioxide ◽  
Exchange Rate ◽  
Water Content ◽  
Intercellular Space ◽  
Leaf Water Content ◽  
Carbon Dioxide Exchange ◽  
Specific Leaf Weight ◽  
Leaf Density ◽  
Effects Of Temperature ◽  
Space Volume

Effects of temperature on (1) physical characteristics of newly matured leaves throughout regrowth, and (2) net carbon dioxide exchange–irradiance response curves throughout regrowth and throughout the day are described for two alfalfa (Medicago saliva L.) genotypes (AT171 and CC120) grown at 20/15C and 30/25C day/night temperatures and 53 nE cm−2 s−1 irradiance (400–700 nm).Area per leaf increased linearly with increasing leaf number up to the fourth or fifth leaf, and thereafter remained constant. Both specific leaf weight and leaf density were constant for the first four leaves, and increased sharply thereafter, particularly at day/night temperatures of 20/15C. Percentage of leaf water content did not change throughout regrowth at 30/25C, but decreased after leaf 4 at 20/15C. Intercellular space volume fluctuated with leaf number. Leaf area was larger, specific leaf weight, and leaf density were greater, intercellular space volume was higher, and percentage of leaf water content was lower, with plants grown at 20/15C than at 30/25C.The net carbon dioxide exchange rate at 116 nE cm−2 s−1 increased with leaves produced progressively until a peak was reached at leaf 4 or 5 and then decreased. At any given leaf position, net carbon dioxide exchange rate at 116 nE cm−2 s−1 was greater at 20/15C than at 30/25C for AT171, but was the same at both temperatures for CC120. In contrast, net carbon dioxide exchange rate at 76 nE cm−2 s−1 was greater at 20/15C than 30/25C for both genotypes. Net carbon dioxide exchange rates measured in the morning were always lower than those measured in the afternoon regardless of irradiance, genotype, and growth temperature.

A Sensitivity Analysis for Effective Use of CO2 for Heat Mining in Geothermal Reservoirs

2015 ◽  
Author(s):  
Ana Laura Soto-Sánchez ◽  
Carlos Rubio-Maya ◽  
Alicia Aguilar Corona ◽  
Oscar Chávez
Keyword(s):  
Carbon Dioxide ◽  
Sensitivity Analysis ◽  
Power Plants ◽  
Control Volume ◽  
Working Fluid ◽  
Unusual Behavior ◽  
Geothermal Heat ◽  
Geothermal Reservoirs ◽  
Linear Behavior ◽  
Better Than

Carbon dioxide (CO2) emitted from various sources, mainly fossil fuel power plants, is considered responsible of the global warming effect. Many processes and techniques are still under research for CO2 capture and sequestration. On the other hand, it is proposed that the geothermal heat be mined from geothermal reservoirs using captured CO2. In this sense, some theoretical studies show feasibility of using supercritical carbon dioxide (sCO2) as a heat mining media in such geothermal reservoirs. In this work, it is carried out a set of numerical simulations to determine the most effective distance between injection and production wells for extracting geothermal energy utilizing sCO2 (Water is used for comparison). In the study, the permeability is considered in the range of 0.5 mD to 3.5 mD, with the aim of determining also the critical point in which sCO2 works better than water (H2O) as a working fluid. The remaining properties such as volume, density and other thermal properties remain fixed. Afterwards, it is constructed a numerical model which is implemented in TOUGH2 and PETRASIM 5 software to simulate the cases established. In the model, it is considered a simplified control volume, i.e. only one well for injection and one for production, assuming a constant flow rate at the inlet and at the outlet, meaning that sequestration is not taken into account. A length of 300 meter is defined for reservoir thickness, considering also a pressure and temperature of 100 bar and 200 °C, respectively. The energy mined is estimated for a period of twenty-five years. As typically, the sensitivity analysis is performed by varying only one property and keeping the remaining properties constant, isolating in this way the effect of such variable. Results show that for small permeabilities H2O works better than sCO2, but it is possible to assure that for permeabilities greater than 1 mD, sCO2 presents more advantages as extracting heat media instead of water. Both, H2O and sCO2 show a linear behavior. A deep analysis is necessary to carry out, because results shows that sCO2 works better in an intermediate zone (greater than 200 meter length, but smaller than 800 meter length). An unusual behavior is presented when the distances between the wells are varied; water shows a linear behavior increasing monotonically, while sCO2 shows a nonlinear behavior for some distances sCO2 works better. As expected, the more the distance, the greater the amount of the energy mined due to the volume related with each one of the distances.

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