THE ESTABLISHMENT OF CARBON DIOXIDE CONCENTRATION GRADIENTS IN ONTARIO WOODLANDS

1966 ◽  
Vol 44 (3) ◽  
pp. 321-329 ◽  
Author(s):  
J. H. Sparling ◽  
M. Alt
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Concentration ◽  
Gas Analyzer ◽  
Concentration Gradients ◽  
Carbon Dioxide Concentrations ◽  
High Concentrations ◽  
Infrared Gas Analyzer

Carbon dioxide concentrations were measured in a number of Ontario woodlands with an infrared gas analyzer. Little evidence of season variation in the concentration of carbon dioxide was obtained. Measurements over 24-hour periods revealed the existence of high concentrations, frequently exceeding 500 p.p.m. at night during midsummer. The high concentrations dropped rapidly at sunrise.The existence of extreme stratification of carbon dioxide which had been reported by earlier workers was not confirmed.

675. The carbon dioxide content of New Zealand Cheddar cheese

1957 ◽  
Vol 24 (2) ◽  
pp. 235-241 ◽  
Author(s):  
P. S. Robertson
Keyword(s):  
Carbon Dioxide ◽  
New Zealand ◽  
Carbon Dioxide Concentration ◽  
Cheddar Cheese ◽  
Carbon Dioxide Content ◽  
Single Strain ◽  
Open Texture ◽  
Factors Influencing ◽  
High Concentrations ◽  
Lower Temperature

Some of the factors influencing the concentration of carbon dioxide found in New Zealand Cheddar cheese have been investigated.1. Cheeses made with the use of commercial starters (containing betacocci) are characterized by a rapid increase in their carbon dioxide content during the 2 weeks following manufacture.2. Cheeses made with the use of single strain starters do not change in carbon dioxide content in the first 2 weeks following manufacture, but may ultimately contain as much carbon dioxide as commercial starter cheeses.3. High concentrations of carbon dioxide within a cheese result in an open texture, especially when the carbon dioxide is formed shortly after manufacture.4. The loss of carbon dioxide to the atmosphere is demonstrated by the existence of a carbon dioxide concentration gradient within the cheese.5. Storage of cheese at a lower temperature than is usual results in retarded carbon dioxide formation.

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.

Infrared Gas Analyzer for Low Concentrations of Carbon Dioxide

1952 ◽  
Vol 24 (3) ◽  
pp. 591-591 ◽  
Author(s):  
J. M. Watkins ◽  
C. L. Gemmill
Keyword(s):  
Carbon Dioxide ◽  
Gas Analyzer ◽  
Low Concentrations ◽  
Infrared Gas Analyzer

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.

Carbon Dioxide and the Regulation of Photosynthesis: Activities of Photosynthetic Enzymes and Carbonate Dehydratase (Carbonic Anhydrase) in Chlorella after Growth or Adaption in Different Carbon Dioxide Concentrations

1977 ◽  
Vol 4 (1) ◽  
pp. 87 ◽  
Author(s):  
M.L Reed ◽  
D Graham
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Chlorella Pyrenoidosa ◽  
Pentose Phosphate ◽  
Fructose Bisphosphate ◽  
Carbon Dioxide Concentrations ◽  
Ribulosebisphosphate Carboxylase ◽  
High Concentrations ◽  
Fraction I

The unicellular green alga Chlorella pyrenoidosa, after growth in air or 5 % (v/v) CO*2, has markedly differing rates of photosynthesis in the presence of very low concentrations of CO*2. It was proposed that the differences could be accounted for by differences in the activities of ribulosebisphosphate carboxylase or other enzymes of the reductive pentose phosphate pathway. This hypothesis was tested and it was shown that between the two types of cells there were no significant differences in the activities of ribulosebisphosphate carboxylase (EC 4.1.1.39), phosphoenolpyruvate carboxylase (EC 4.1.1.31), phosphoenolpyruvate carboxykinase (ATP) (EC 4.1.1.49), glyceraldehyde-phosphate dehydrogenase (NADP) (EC 1.2.1.9), hexosebisphosphatase (EC 3.1.3.11), fructose-bisphosphate aldolase (EC 4.1.2.13), ribosephosphate isomerase (EC 5.3.1.6) and phosphoribulokinase (EC 2.7.1.19). There was also no difference between air-grown and 5% CO*2-grown cells in the content of fraction I protein isolated by disc gel electrophoresis and measured by a colorimetric procedure. A fivefold or sixfold increase in rate of photosynthesis occurs during about 90 min when 5% CO*2-grown Chlorella is illuminated in the presence of a very low CO*2 concentration (approximately 1 �M free CO*2, which is about one-tenth the concentration of CO*2 in distilled water in equilibrium with air). During this increase, the only photosynthetic enzyme to change in activity was carbonate dehydratase (carbonic anhydrase, EC 4.2.1.1). This enzyme was absent from cells grown with 5% CO*2 but was present in air-grown cells. The enzyme appears to be induced by low CO*2 concentrations and repressed by high concentrations. It was concluded that carbonate dehydratase plays a major regulatory role in photosynthesis in Chlorella at low CO*2 concentrations.

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.

THE EFFECT OF LIGHT AND TEMPERATURE ON THE GROWTH AND RESPIRATION OF BOTRYTIS SQUAMOSA

1958 ◽  
Vol 36 (6) ◽  
pp. 927-934 ◽  
Author(s):  
R. H. Stinson ◽  
R. S. Gage ◽  
E. B. MacNaughton
Keyword(s):  
Carbon Dioxide ◽  
Maximum Growth ◽  
Temperature Sensitive ◽  
Gas Analyzer ◽  
Botrytis Squamosa ◽  
Light Levels ◽  
Considerable Portion ◽  
Mycelial Mass ◽  
Infrared Gas Analyzer ◽  
Effect Of Light

The fungus organism Botrytis squamosa Walker when maintained at constant temperature is unaffected by light levels as high as 100 ft-c for periods of several days and by levels of 250 ft-c for periods of a few hours. This is contrary to an earlier report which said that an illuminance of 70 ft-c would prevent growth of the organism. It is suspected that a combination of undetected temperature gradients and the variability of the organism lead to the earlier report of a light inhibition.The organism is temperature sensitive. No growth occurred at, or beyond, 30 °C. Maximum growth occurred at 23 °C, the lowest temperature used in the investigations.While all portions of the mycelial mass evolve some carbon dioxide, the most active evolution is generally around the circumference. Variations in age and circumference accounted for a considerable portion of the variability in the carbon dioxide evolution.Measuring techniques involved the use of thermocouples, a radiation thermopile and photronic cell, and an infrared gas analyzer.

Sign in / Sign up

Export Citation Format

Share Document