EFFECT OF TEMPERATURE ON NET CARBON DIOXIDE EXCHANGE RATES OF TWELVE BARLEY VARIETIES

1968 ◽  
Vol 48 (4) ◽  
pp. 363-368 ◽  
Author(s):  
D. P. Ormrod ◽  
W. F. Hubbard ◽  
D. G. Faris
Keyword(s):  
Carbon Dioxide ◽  
Exchange Rates ◽  
Effect Of Temperature ◽  
Carbon Dioxide Exchange ◽  
Controlled Environment ◽  
Response Curves ◽  
Gradual Decline ◽  
Carbon Dioxide Uptake ◽  
Higher Temperature ◽  
Increasing Temperature

Seedlings of 12 barley varieties were grown in a controlled environment to 21 days of age and then transferred to an apparatus for measuring net carbon dioxide exchange rates. Rates were measured at temperatures ranging from 4 to 34 °C and the results were plotted to provide a response curve for each variety. The response curves were not clearly different between varieties, but some trends were evident. The varieties Husky, Parkland and Vantmore had response curves of similar shape with marked increases with increasing temperature to 14 to 18 °C. Asa, Olli and Pirkka showed a more gradual rise to about 20 °C. Varieties O.A.C. 21, Vantage and Wolfe showed a very rapid increase in carbon dioxide uptake to about 6 °C followed by very little change to 20 °C, leading into a gradual decline. Stavropol, Trebi and White Gatami had maximum rates at a higher temperature. The patterns presented by the varieties may be related to different areas of origin and production. Varieties were markedly different at low temperatures but differed little in response to temperatures near 34 °C. Absolute rates of net carbon dioxide exchange differed markedly among varieties.

Effects of pretreatment temperature on carbon dioxide exchange in alfalfa

1972 ◽  
Vol 50 (9) ◽  
pp. 1925-1930 ◽  
Author(s):  
C. J. Pearson ◽  
L. A. Hunt
Keyword(s):  
Carbon Dioxide ◽  
Temperature Response ◽  
Day Length ◽  
Carbon Dioxide Exchange ◽  
Response Curves ◽  
Free Atmosphere ◽  
Pretreatment Temperature ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
The Relationship

The temperature response curves for net carbon dioxide exchange are described for plants of cultivars (cvs.) Vernal and Moapa alfalfa (Medicago sativa L.) grown at day/night temperatures of 30/25C and 20/15C, an irradiance of 25 nE cm−2 s−1 (400–700 nm), and a day length of 15.5 h. Net carbon dioxide intake (NCI) of the tops decreased with increasing temperature from 20 mg dm−2 h−1 at 10C to 5 mg dm−2 h−1 at 40C. The nature of the NCI-temperature response curve was affected by pretreatment temperature, with NCI being lower at all temperatures except 10C after growth at 20/15C. Photorespiration, which reached its maximum value at a higher temperature (20–30C) than that required for maximum NCI, accounted for 22% of the gross carbon dioxide intake (net carbon dioxide exchange in an oxygen-free atmosphere) at 10C and 55% at 40C. Pretreatment affected the relationship between net carbon dioxide output (NCO) and temperature, with NCO being higher at 10C but lower at 30C after growth at 20/15C as compared to 30/25C.

Atomistic simulation for configuration evolution and energetic calculation of crack in body-centered-cubic iron

2006 ◽  
Vol 21 (10) ◽  
pp. 2542-2549 ◽  
Author(s):  
Li-Xia Cao ◽  
Chong-Yu Wang
Keyword(s):  
Low Temperatures ◽  
Crack Tip ◽  
Dislocation Nucleation ◽  
Effect Of Temperature ◽  
Body Centered Cubic ◽  
Partial Dislocations ◽  
Higher Temperature ◽  
Crack Blunting ◽  
Increasing Temperature ◽  
Extended Dislocation

The molecular dynamics method has been used to simulate mode I cracking in body-centered-cubic iron. Close attention has been paid to the process of the atomic configuration evolution of the cracks. The simulation shows that at low temperatures, partial dislocations are emitted before the initiation of crack propagation, subsequently forming the stacking faults or multilayer twins on {112} planes, and then brittle cleavage and extended dislocation nucleation are observed at the crack tip accompanied by twin extension. These results are in agreement with the experimental observation that twinning and fracture processes cooperate at low temperatures. Furthermore, an energetics analysis has been made on the deformation behavior observed at the crack tip. The effect of temperature on the fracture process is discussed. At the higher temperature, plastic deformation becomes easier, and crack blunting occurs. With increasing temperature, the fracture resistance increases, and the effect of the lattice trapping can be weakened by thermal activation.

scholarly journals Inclination to self-ignition and analysis of gaseous products of wood chips heating

2020 ◽  
Vol 13 (1) ◽  
pp. 88-97
Author(s):  
Michaela Skrizovska ◽  
Hana Veznikova ◽  
Petra Roupcova
Keyword(s):  
Carbon Dioxide ◽  
Fourier Transformation ◽  
Wood Chips ◽  
Effect Of Temperature ◽  
European Standard ◽  
Gaseous Products ◽  
Self Heating ◽  
Infrared Spectrometer ◽  
Increasing Temperature ◽  
Solid Biomass

AbstractThis paper focuses on the assessment of the inclination to self-ignition of various types of wood chips according to the methodology of European standard EN 15188. The study also assesses the effect of heating temperatures on the composition and quantity of gaseous products of heating. Gases were analysed using an infrared spectrometer with Fourier transformation. From the measured results it was found that the inclination to self-ignition differs for various samples of wood chips. The paper discusses certain parameters assumed to affect the inclination of biomass to self-ignite. When assessing the effect of temperature on the composition of gaseous products, a sample of forest wood chips heated at temperatures from 50 to 150 °C resulted in the following gaseous products: carbon dioxide, carbon monoxide, water and aliphatic hydrocarbons; their concentrations increase with the increasing temperature. Carbon oxides have been proposed as indicators of the state of stored materials self-heating. Observations presented in this paper can be used as data for elaborating safety instructions for storage of fuels based on solid biomass.

CARBON DIOXIDE EXCHANGE RATES OF FRUITING SOYBEAN PLANTS EXPOSED TO OZONE AND SULPHUR DIOXIDE SINGLY OR IN COMBINATION

1984 ◽  
Vol 64 (1) ◽  
pp. 69-75 ◽  
Author(s):  
N. M. LE SUEUR-BRYMER ◽  
D. P. ORMROD
Keyword(s):  
Carbon Dioxide ◽  
Glycine Max ◽  
Exchange Rates ◽  
Sulphur Dioxide ◽  
Net Photosynthesis ◽  
Exposure Period ◽  
Carbon Dioxide Exchange ◽  
Continuous Stirred Tank Reactor ◽  
Glycine Max L ◽  
Soybean Plants

Carbon dioxide exchange rates (CER) of intact soybean (Glycine max (L.) Merr.) plants at the fruiting stage were measured in continuous stirred tank reactor (CSTR) chambers. Plants were exposed to clean air, 67 ppb ozone (O3), 300 ppb sulphur dioxide (SO2), or 67 ppb O3 plus 300 ppb SO2 for 7.5 h∙day−1 for 5 days. Carbon dioxide exchange rates were measured hourly during the last 6 h of each exposure period and decreased progressively during the first period of exposure to O3 plus SO2, dropping in hour 6 to 42% of the hour 1 rate, and to a lesser extent in the second daily exposure when the corresponding decline was to 70%. There was a declining trend in CER of SO2-treated but not O3-treated plants with increasing number of days of exposure. Carbon dioxide exchange rates of all plants generally peaked and declined during each exposure period.Key words: Air pollution, net photosynthesis, mixtures, Glycine max

Estimating carbon dioxide exchange rates at contrasting northern peatlands using MODIS satellite data

2013 ◽  
Vol 137 ◽  
pp. 234-243 ◽  
Author(s):  
Angela Kross ◽  
Jonathan W. Seaquist ◽  
Nigel T. Roulet ◽  
Richard Fernandes ◽  
Oliver Sonnentag
Keyword(s):  
Carbon Dioxide ◽  
Exchange Rates ◽  
Satellite Data ◽  
Carbon Dioxide Exchange ◽  
Northern Peatlands
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