Photosynthesis of wheat under field conditions. II.* Effect of defoliation on the carbon dioxide uptake of the community

1969 ◽  
Vol 20 (4) ◽  
pp. 623
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Flag Leaf ◽  
Wheat Plant ◽  
Horizontal Component ◽  
Field Conditions ◽  
The Sun ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber ◽  
Before And After

A field assimilation chamber was used to measure the carbon dioxide uptake of wheat plants in the field before and after defoliation or ear removal. At anthesis and 10 days later only the top three leaves were effective in photosynthesis. Removal of the two leaves below the flag leaf reduced photosynthesis of the community by 25–28% and further removal of the flag leaf reduced the community photosynthesis by an additional 24–30%. The estimated contribution of the ears depended on the technique of measurement and varied from 7 to 15%. After removal of the leaf laminae and ears, the stems and leaf sheaths assimilated carbon dioxide at a rate of 44% of that of the whole community. For defoliated plants, photosynthesis of the ears and stems increased with increasing elevation of the sun, which indicated a greater efficiency of photosynthesis with an increased horizontal component of radiation. This was opposite to the response of the undefoliated community. The techniques of estimating the contribution of individual organs to total photosynthesis of the wheat plant are discussed in relation to variability of results and the effects of compensation. * Part I, Aust. J. Agric. Res., 1968, 19: 711.

Corrigendum - Photosynthesis of wheat under field conditions. II. Effect of defoliation on the carbon dioxide uptake of the community

1969 ◽  
Vol 20 (4) ◽  
pp. 623
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Flag Leaf ◽  
Wheat Plant ◽  
Horizontal Component ◽  
Field Conditions ◽  
The Sun ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber ◽  
Before And After

A field assimilation chamber was used to measure the carbon dioxide uptake of wheat plants in the field before and after defoliation or ear removal. At anthesis and 10 days later only the top three leaves were effective in photosynthesis. Removal of the two leaves below the flag leaf reduced photosynthesis of the community by 25–28% and further removal of the flag leaf reduced the community photosynthesis by an additional 24–30%. The estimated contribution of the ears depended on the technique of measurement and varied from 7 to 15%. After removal of the leaf laminae and ears, the stems and leaf sheaths assimilated carbon dioxide at a rate of 44% of that of the whole community. For defoliated plants, photosynthesis of the ears and stems increased with increasing elevation of the sun, which indicated a greater efficiency of photosynthesis with an increased horizontal component of radiation. This was opposite to the response of the undefoliated community. The techniques of estimating the contribution of individual organs to total photosynthesis of the wheat plant are discussed in relation to variability of results and the effects of compensation.

Photosynthesis of wheat under field conditions. III. Seasonal trends in carbon dioxide uptake of crop communities

1971 ◽  
Vol 22 (1) ◽  
pp. 1 ◽  
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Weight ◽  
Field Conditions ◽  
Wheat Cultivars ◽  
Area Index ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber

Photosynthesis of two wheat cultivars grown in the field was examined during three seasons by use of a portable field assimilation chamber. There were large differences in dry weight, leaf area, and carbon dioxide uptake between seasons. Variations in carbon dioxide uptake by the community were related mainly to changes in leaf area index (LAI). There were changes in carbon dioxide uptake per unit LAI with time, and between the two cultivars in the first season, but the effects of these changes were small compared with the effects of LAI. Differences in grain yield were correlated with LAI and carbon dioxide uptake in the period after anthesis.

Photosynthesis of wheat under field conditions. V.* The effect of sugar elevation on the distribution of photosynthetic activity within the crop canopy

1972 ◽  
Vol 23 (3) ◽  
pp. 397 ◽  
Author(s):  
DW Puckridge
Keyword(s):  
Photosynthetic Activity ◽  
Specific Activity ◽  
Dry Weight ◽  
Total Carbon ◽  
The Sun ◽  
Crop Canopy ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber ◽  
Solar Elevation ◽  
Relative Contribution

The distribution of photosynthetic activity within the canopy of a wheat community was measured at different times of the day Plants In the field were covered by a Perspex assimilation chamber and exposed to 14CO2 and light for 15 min., then harvested and dissected. The relative specific activity and dry weight of the parts, and the calculated total carbon dioxide uptake of the community were then used to determine the distribution of photosynthesis within the community. The contribution of the lower leaves and leaf sheaths increased with increasing elevation of the sun up to 67°, while the photosynthesis of the flag leaves approached a maximum when the elevation of the sun was only 28°. The relative contribution of the ears to total photosynthesis decreased from 33 to 13% as the solar elevation increased from 17 to 67°. __________________ *Part IV, Aust. J. Agric. Res., 22: 1 I (1971).

Carbon Capture Performance of Amino-Modified MIL-101 at Room Temperature

2013 ◽  
Vol 395-396 ◽  
pp. 637-640
Author(s):  
Yi Yang ◽  
Zheng Ping Wang ◽  
Ling Meng ◽  
Lian Jun Wang
Keyword(s):  
Carbon Dioxide ◽  
Specific Surface ◽  
Pore Structure ◽  
Carbon Capture ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Metal Organic Framework ◽  
Adsorption Properties ◽  
Carbon Dioxide Adsorption ◽  
Before And After

MIL-101, a metal-organic framework material, was synthesized by the high-temperature hydrothermal method. Triethylenetetramine (TETA) modification enabled the effective grafting of an amino group onto the surface of the materials and their pore structure. The crystal structure, micromorphology, specific surface area, and pore structure of the samples before and after modification were analyzed with an X-ray diffractometer, scanning electron microscope, specific surface and aperture tester, and infrared spectrometer. The carbon dioxide adsorption properties of the samples were determined by a thermal analyzer before and after TETA modification. Results show that moderate amino modification can effectively improve the microporous structure of MIL-101 and its carbon dioxide adsorption properties. After modification, the capacity of MIL-101 to adsorb carbon dioxide decreased only by 0.61 wt%, and a high adsorption capacity of 9.45 wt% was maintained after six cycles of adsorption testing at room temperature and ambient pressure.

Split face comparative study of microneedling with platelet rich plasma versus Fractional carbon dioxide laser with platelet rich plasma in treatment of atrophic post acne scars

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Mohamed Abd Elnaeem Sallam ◽  
Khaled El Zawahry ◽  
Abdul Rahman Muhammed Ali Mustafa
Keyword(s):  
Carbon Dioxide ◽  
Co2 Laser ◽  
Carbon Dioxide Laser ◽  
Platelet Rich Plasma ◽  
Fractional Co2 Laser ◽  
Acne Scars ◽  
Significant Difference ◽  
Before And After ◽  
The Face ◽  
Fractional Carbon Dioxide Laser

Abstract Background Acne scars, is a challenge for dermatologists, despite having multiple treatment modalities like microneedling, dermabrasion, Fractional CO2 Laser, dermal fillers, etc. However, monotherapy has been hardly satisfactory because of the polymorphism seen with the scars. Objective Comparison between microneedling with platelet rich plasma versus Fractional carbon dioxide laser with platelet rich plasma in treatment of atrophic post acne scars. Patients and methods This study was carried out in department of dermatology, venereology and andrology, in Kobry El-Kobba Military complex during the period (from September 2018 to July 2020 ) on 20 patients of both sexes aged from 20 to 60 years old presenting with Goodman and Baron Grade II, III, IV acne scars . Results The study revealed a statistically significant difference (p = 0.017) between Goodman and Baron scar grades on the right side of the face before and after treatment indicating that microneedling with platelet rich plasma was effective in improving acne scars. Also, there is a statistically significant difference (p = 0.010) between Goodman and Baron scar grades on the left side of the face before and after treatment, indicating that fractional CO2 laser with platelet rich plasma was effective in improving acne scars. Conclusion and recommendation Further controlled and randomized studies are needed to validate our findings in a larger cohort of patients and longer follow up. Also, number of sessions might be more than 3 sessions.

Breathing in brief exercise

1960 ◽  
Vol 15 (4) ◽  
pp. 583-588 ◽  
Author(s):  
F. N. Craig ◽  
E. G. Cummings
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Metabolic Cost ◽  
Carbon Dioxide Tension ◽  
Minute Volume ◽  
Carbon Dioxide Output ◽  
Respiratory Minute Volume ◽  
Before And After

Two men ran for 20 or 60 seconds while inhaling air, oxygen or 4% carbon dioxide. Inspired respiratory minute volume was determined for each breath. Ventilation increased suddenly in the first breath with minimal changes in end-expiratory carbon dioxide tension and respiratory exchange ratio to a rate that remained constant for 20 seconds before increasing further. The rate of carbon dioxide output was uniform during the first 20 seconds. A 12% grade did not increase ventilation or oxygen uptake during runs of 20 seconds, but in the first minute of recovery, ventilation was 64% greater than after level runs. Inhalation of oxygen inhibited ventilation by 24% in the 20-second periods before and after the end of a 60-second run. Inhalation of carbon dioxide begun at rest produced increments in ventilation and end-expiratory carbon dioxide tension that varied little during running and recovery. In the 20-second runs ventilation varied with speed but appeared independent of ultimate metabolic cost. Submitted on January 21, 1960

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