scholarly journals Cowpea development under different temperatures and carbon dioxide concentrations

2020 ◽  
Vol 50 ◽  
Author(s):  
Francislene Angelotti ◽  
Laise Guerra Barbosa ◽  
Juliane Rafaele Alves Barros ◽  
Carlos Antonio Fernandes dos Santos
Keyword(s):  
Carbon Dioxide ◽  
Seed Weight ◽  
Carbon Dioxide Concentration ◽  
Cowpea Cultivars ◽  
Randomized Design ◽  
Flower Abortion ◽  
Carbon Dioxide Concentrations ◽  
Different Temperatures ◽  
Reproductive Phases ◽  
The Impact

ABSTRACT The increase of CO2 concentrations and temperatures may affect the plant development and production. This study aimed to evaluate the impact of the increased temperature and carbon dioxide concentration on the development of cowpea cultivars. The experiment was conducted in growth chambers, with control of CO2 and temperature. A completely randomized design was carried out, in a 4 x 3 x 2 factorial arrangement [cultivar x temperature (day/night) x CO2], with three replicates. The duration of the cowpea vegetative and reproductive phases was evaluated and, at the end of the experiment, the number of pods per plant, number of grains per pod, seed weight, shoot fresh and dry matter weight were quantified. Temperature affects the development of cowpea cultivars, and the temperatures of 29 ºC (day)/23 ºC (night) lead to a higher seed weight. The increase of CO2 leads to a higher number of pods and seeds and seed weight. The BRS Tapaihum cultivar presented the highest number of pods and seeds and seed weight. In addition, the temperatures of 32 ºC (day)/29 ºC (night) lead to a greater flower abortion in the BRS Pujante and BRS Tapaihum cultivars.

scholarly journals Technical Note: Long-term memory effect in the atmospheric CO<sub>2</sub> concentration at Mauna Loa

2006 ◽  
Vol 6 (6) ◽  
pp. 11957-11970 ◽  
Author(s):  
C. Varotsos ◽  
M.-N. Assimakopoulos ◽  
M. Efstathiou
Keyword(s):  
Carbon Dioxide ◽  
Time Series ◽  
Power Law ◽  
Carbon Dioxide Concentration ◽  
Global Climate Models ◽  
Fluctuation Analysis ◽  
Original Time Series ◽  
Mauna Loa ◽  
Carbon Dioxide Concentrations ◽  
Original Time

Abstract. The monthly mean values of the atmospheric carbon dioxide concentration derived from in-situ air samples collected at Mauna Loa Observatory, Hawaii, during 1958–2004 (the longest continuous record available in the world) are analyzed by employing the detrended fluctuation analysis to detect scaling behavior in this time series. The main result is that the fluctuations of carbon dioxide concentrations exhibit long-range power-law correlations (long memory) with lag times ranging from four months to eleven years, which correspond to 1/f noise. This result indicates that random perturbations in the carbon dioxide concentrations give rise to noise, characterized by a frequency spectrum following a power-law with exponent that approaches to one; the latter shows that the correlation times grow strongly. This feature is pointing out that a correctly rescaled subset of the original time series of the carbon dioxide concentrations resembles the original time series. Finally, the power-law relationship derived from the real measurements of the carbon dioxide concentrations could also serve as a tool to improve the confidence of the atmospheric chemistry-transport and global climate models.

An Investigation of the Sources of Blowby in Single-Cylinder Supercharged Diesel Engines

1978 ◽  
Vol 192 (1) ◽  
pp. 39-48 ◽  
Author(s):  
B. Bull ◽  
M. A. Voisey
Keyword(s):  
Carbon Dioxide ◽  
Diesel Engines ◽  
Piston Ring ◽  
Carbon Dioxide Concentration ◽  
Operating Conditions ◽  
Exhaust Valve ◽  
Simple Method ◽  
Single Cylinder ◽  
Carbon Dioxide Concentrations ◽  
Wide Range

Measurements of carbon dioxide concentrations in the exhaust and in the crankcase of two different types of single-cylinder, supercharged diesel engines have been used to determine the amount of exhaust gas reaching the crankcase as piston ring blowby and as leakage through the exhaust valve stem-to-guide clearance. Over a wide range of operating conditions in both engines the carbon dioxide concentration was found to be more dependent on engine fuelling rate per hour than on fuel input per stroke. It was established that blowby through the exhaust valve guide was a major contributor to crankcase contamination. A simple method has been devised, requiring only minor modifications to the engine, that permits the blowby through the piston ring pack and the exhaust valve guides to be determined separately in turbocharged production engines.

Respiration in cropped and fallow soil

1979 ◽  
Vol 92 (1) ◽  
pp. 45-51 ◽  
Author(s):  
D. T. Pritchard ◽  
N. J. Brown
Keyword(s):  
Carbon Dioxide ◽  
Gas Chromatography ◽  
Soil Moisture ◽  
Moisture Content ◽  
Temperature Effects ◽  
Root Respiration ◽  
Soil Moisture Content ◽  
Carbon Dioxide Concentration ◽  
Carbon Dioxide Concentrations ◽  
Fallow Soil

SummarySoil air was sampled daily at depths of 5, 10, 20 and 30 cm in fallow and cropped plots, which had either been rolled or cultivated. Carbon dioxide was measured by gas chromatography.Carbon dioxide concentrations were greater in the cropped than in the fallow plots. The rolled plots were wetter than the cultivated plots and carbon dioxide concentrations were also greater.In the fallow plots, carbon dioxide was correlated with soil temperature but variations in soil moisture content had little immediate effect.In the cropped plots, temperature effects were overshadowed by the response to irrigation which immediately increased the carbon dioxide concentration. These increases were attributed to enhanced root respiration, rather than to restricted diffusion or increased microbial activity.

scholarly journals Photosynthetic Responses of Swiss Chard, Kale, and Spinach Cultivars to Irradiance and Carbon Dioxide Concentration

HortScience ◽  
2017 ◽  
Vol 52 (5) ◽  
pp. 706-712 ◽  
Author(s):  
John Erwin ◽  
Esther Gesick
Keyword(s):  
Carbon Dioxide ◽  
Dark Respiration ◽  
Carbon Dioxide Concentration ◽  
Controlled Environment ◽  
Plant Responses ◽  
Whole Plant ◽  
Swiss Chard ◽  
Spinacea Oleracea ◽  
Photosynthetic Responses ◽  
The Impact

The impact of irradiance (0–1200 μmol·m−2·s−1) and carbon dioxide concentration (CO2; 50–1200 ppm) on kale (Brassica oleracea and B. napus pabularia; three cultivars), Swiss chard (chard, Beta vulgaris; four cultivars), and spinach (Spinacea oleracea; three cultivars) photosynthetic rate (Pn; per area basis) was determined to facilitate maximizing yield in controlled environment production. Spinach, chard, and kale maximum Pn were 23.8, 20.3, and 18.2 μmol CO2·m−2·s−1 fixed, respectively, across varieties (400 ppm CO2). Spinach and kale had the highest and lowest light compensation points [LCPs (73 and 13 μmol·m−2·s−1, respectively)] across varieties. The light saturation points (LSPs) for chard and kale were similar at 884–978 μmol·m−2·s−1, but for spinach, the LSP was higher at 1238 μmol·m−2·s−1. Dark respiration was lowest on kale and highest on spinach (−0.83 and −5.00 μmol CO2·m−2·s−1, respectively). The spinach CO2 compensation point (CCP) was lower (56 ppm) than the chard or kale CCP (64–65 ppm). Among varieties, ‘Red Russian’ kale Pn saturated at the lowest CO2 concentration (858 ppm), and ‘Bright Lights’ chard saturated at the highest (1266 ppm; 300 μmol·m−2·s−1). Spinach Pn was more responsive to increasing irradiance than to CO2. Kale Pn was more responsive to increasing CO2 than to irradiance, and chard Pn was equally responsive to increasing CO2 or irradiance. Implications and limitations of this work when “upscaling” to whole-plant responses are discussed.

scholarly journals Detecting causality signal in instrumental measurements and climate model simulations: global warming case study

2019 ◽  
Author(s):  
Mikhail Y. Verbitsky ◽  
Michael E. Mann ◽  
Byron A. Steinman ◽  
Dmitry M. Volobuev
Keyword(s):  
Carbon Dioxide ◽  
Time Series ◽  
Atmospheric Carbon Dioxide ◽  
Climate Model ◽  
Carbon Dioxide Concentration ◽  
Anthropogenic Forcing ◽  
Carbon Dioxide Concentrations ◽  
Climate Model Simulations ◽  
Earth’S Climate

Abstract. Detecting the direction and strength of the causality signal in observed time series is becoming a popular tool for exploration of distributed systems such as Earth's climate system. Here we suggest that in addition to reproducing observed time series of climate variables within required accuracy a model should also exhibit the causality relationship between variables found in nature. Specifically, we propose a novel framework for a comprehensive analysis of climate model responses to external natural and anthropogenic forcing based on the method of conditional dispersion. As an illustration, we assess the causal relationship between anthropogenic forcing (i.e., atmospheric carbon dioxide concentration) and surface temperature anomalies. We demonstrate a strong directional causality between global temperatures and carbon dioxide concentrations (meaning that carbon dioxide affects temperature stronger than temperature affects carbon dioxide) in both the observations and in (CMIP5) climate model simulated temperatures.

Environment in stone chamber of an unexcavated tumulus and preservation of buried relics: Part 1. Environmental monitoring for simulated tumulus

2020 ◽  
pp. 174425912091390
Author(s):  
Huarong Xie ◽  
Daisuke Ogura ◽  
Hiroyuki Yasui ◽  
Nobumitsu Takatori ◽  
Shuichi Hokoi ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Environmental Monitoring ◽  
Oxygen Concentration ◽  
Carbon Dioxide Concentration ◽  
Metal Corrosion ◽  
Small Temperature ◽  
Carbon Dioxide Concentrations ◽  
Hygrothermal Environments ◽  
Term Monitoring

Japan has many unexcavated tumuli, most of which were buried along with artifacts of precious cultural heritage. For such a tumulus, it is essential to understand how changes in its exterior environment affect its interior environment, and how those interior changes affect the deterioration of the relics buried in the stone chamber. In this study, an underground space was constructed in the forest of the Katsura Campus of Kyoto University to simulate the environment of an unexcavated tumulus, and long-term monitoring was implemented in the simulated stone chamber, including the temperature, humidity, water potential, wetness, and oxygen and carbon dioxide concentrations, along with metal corrosion tests. This article is focused on environmental monitoring, and the results demonstrate that the simulated tumulus has the general characteristics of the hygrothermal environments of an unexcavated tumulus that has small temperature fluctuation and near-saturation humidity. The ceiling of the simulated chamber condensed significantly from October to April, which is related to the variations of the ceiling and floor temperatures. Also, the wetness of the walls in the simulated chamber was affected by rainfall. The oxygen concentration in the simulated stone chamber varied in the range of 13%–19% in 2015, and the variation of carbon dioxide concentration in the simulated stone chamber was contrary to the oxygen concentration and varied in the range of 3%–9% in 2016. The oxygen concentration in the stone chamber was similar to that in the surrounding soil that decreased at times of rainfall, contrary to the fluctuations in the soil water content.

Fuel Property Effects on the Fate of Volume Distributed Combustion

2016 ◽  
Author(s):  
Ahmed E. E. Khalil ◽  
Ashwani K. Gupta
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Concentration ◽  
Gas Temperature ◽  
Field Uniformity ◽  
Different Temperatures ◽  
Pollutants Emission ◽  
Reactive Gases ◽  
Colorless Distributed Combustion ◽  
The Impact ◽  
No Emissions

Colorless Distributed Combustion (CDC) has been shown to provide singular benefits on ultra-low pollutants emission, enhanced stability and thermal field uniformity. To achieve CDC conditions, fuel-air mixture must be properly prepared and mixed with hot reactive gases from within the combustor prior to the mixture ignition. Hot reactive gases reduce the oxygen concentration in the mixture while increasing its temperature. In this paper, the impact of fuel type (methane, propane, and hydrogen enriched methane) on achieving distributed combustion is investigated. A mixture of nitrogen and carbon dioxide was mixed to simulate the hot recirculated gases at different temperatures using normal air upstream of the combustor. Increasing the amounts of nitrogen and carbon dioxide reduced the oxygen concentration within the combustor. Distributed combustion was identified through OH* chemiluminescence distribution across the combustor. For methane, this oxygen concentration varied between 13.8% and 11.2% (depending on the mixture temperature) with some 85% reduction in NO emissions as compared to that without entrainment. Similar behavior was demonstrated with propane and hydrogen enriched methane, albeit at a lower oxygen concentration (13.7%–11.6% and 12.2%–10.5%), to result in 94% and 92% reduction in NO emission, respectively. The inlet gas temperature was varied between 300K and 750K. Experimental data using a variety of fuels showed NO emissions of 1 PPM or less. Analysis and extrapolation of obtained data suggest that distributed combustion can be achieved at an oxygen concentration of 9.5% for hot reactive entrained gases having a temperature of 1800K. This value may be used as a guideline to achieve distributed combustion with ultra-low emission.

scholarly journals Infection by Xanthomonas campestris pv.viticola under temperature increase and carbon dioxide concentrations

2018 ◽  
Vol 8 (2) ◽  
pp. 214-220
Author(s):  
Jaime Luiz Albuquerque Conceição ◽  
FRANCISLENE ANGELOTTI ◽  
Ana Rosa Peixoto ◽  
Raquel Ghini
Keyword(s):  
Carbon Dioxide ◽  
Incubation Period ◽  
Temperature Increase ◽  
Xanthomonas Campestris ◽  
Carbon Dioxide Concentration ◽  
Co2 Concentration ◽  
Bacterial Suspension ◽  
Bacterial Canker ◽  
Progress Curve ◽  
The Impact

The experiments were carried out under controlled conditions to evaluate the impact of increased temperature and concentration of carbon dioxide on infection of Xanthomonas campestris pv viticola, the causal agent of bacterial canker in Vine seedlings. It proceeded the evaluation of the following epidemiological components: incubation period (PI), severity (SEV) and using that data were calculated the area under the disease progress curve (AUDPC). It used grape seedlings (Italia, Crimson Seedless, Sugraone and Selection 8) inoculated with bacterial suspension (108 CFU mL-1). The experimental design was completely randomized, factorial arrangement 4x4 (cultivar x temperature) and 4x2 (cultivar x carbon dioxide concentration) which was carried out twice. The data were subjected to variance analysis. Increasing temperature reduced bacterium’s incubation period with significant differences between genotypes. For Selection 8 and Crimson temperature increase caused enhancement on severity and AUDPC. For Seleção 8 the incubation period (PI) was extended from 7.93 to 30.18 days when the concentration changed from 390 to 770 µmol/mol. The increased CO2 concentration reduced AACPSD and SEV for Sugraone and Selection 8. The results show that the temperature and carbon dioxide (CO2) concentration of the air may have different effects on bacterial canker of grapevine.

scholarly journals Nature-Based Resilience: A Multi-Type Evaluation of Productive Green Infrastructure in Agricultural Settings in Ontario, Canada

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1183
Author(s):  
Vidya Anderson ◽  
William A. Gough
Keyword(s):  
Carbon Dioxide ◽  
Green Infrastructure ◽  
Climate Change Impacts ◽  
Air Pollutant ◽  
Agricultural Practice ◽  
Mitigation And Adaptation ◽  
Climate Resilience ◽  
Carbon Dioxide Concentrations ◽  
New Findings ◽  
The Impact

Nature-based solutions such as green infrastructure present an opportunity to reduce air pollutant concentrations and greenhouse gas emissions. This paper presents new findings from a controlled field study in Ontario, Canada, evaluating the impact of productive applications of green infrastructure on air pollution and carbon dioxide concentrations across different agricultural morphologies compared to other non-productive applications. This study demonstrates that productive green infrastructure applications are as beneficial as non-productive applications in reducing ozone, nitrogen dioxide, and carbon dioxide concentrations. Nature-based solutions present an opportunity to build climate resilience into agricultural systems through supply-side mitigation and adaptation. The implementation of productive green infrastructure could be a viable agricultural practice to address multiple climate change impacts.

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