scholarly journals Photosynthesis of Tropical Pasture Plants II. Temperature and Illuminance History

1971 ◽  
Vol 24 (4) ◽  
pp. 1065 ◽  
Author(s):  
MM Ludlow ◽  
GL Wilson
Keyword(s):  
Carbon Dioxide ◽  
Water Vapour ◽  
Gas Analysis ◽  
Controlled Environment ◽  
Tropical Pasture ◽  
Two Temperatures ◽  
Analysis System ◽  
Pasture Plants

Grasses and legumes were grown at two temperatures in controlled-environment rooms and at three illuminances (obtained by shading) in a glasshouse. Carbon dioxide and water vapour exchange of leaves were measured in an open gas analysis system.

scholarly journals Photosynthesis of Tropical Pasture Plants III. Leaf Age

1971 ◽  
Vol 24 (4) ◽  
pp. 1077 ◽  
Author(s):  
MM Ludlow ◽  
GL Wilson
Keyword(s):  
Dark Respiration ◽  
Leaf Age ◽  
Gas Analysis ◽  
Controlled Environment ◽  
Tropical Pasture ◽  
Optimum Conditions ◽  
Dark Respiration Rate ◽  
Leaf Ontogeny ◽  
Analysis System ◽  
Pasture Plants

Grass and legume plants were grown under near-optimum conditions in controlled-environment cabinets. Changes in net photosynthetic rate, dark respiration rate, and carbon dioxide transfer resistances during leaf ontogeny, and variability between leaves on grass tillers and legume runners were studied under controlled conditions in an open gas analysis system.

scholarly journals Photosynthesis of Tropical Pasture Plants I. Illuminance, Carbon Dioxide Concentration, Leaf Temperature, and Leaf-Air Vapour Pressure Difference

1971 ◽  
Vol 24 (3) ◽  
pp. 449 ◽  
Author(s):  
M M Ludlow ◽  
GL Wilson
Keyword(s):  
Carbon Dioxide ◽  
Vapour Pressure ◽  
Pressure Difference ◽  
Carbon Dioxide Concentration ◽  
Gas Analysis ◽  
Leaf Temperature ◽  
Tropical Pasture ◽  
Analysis System ◽  
Vapour Pressure Difference ◽  
Pasture Plants

Carbon dioxide and water vapour exchange of attached, young, fully expanded leaves of tropical pasture species were measured in an open gas analysis system. The influence of illuminance, carbon dioxide concentration, leaf temperature, and leaf-air vapour pressure difference on net photosynthetic rate and carbon dioxide transfer resistances was studied.

scholarly journals INVESTIGATION AND EVALUATION OF CARBON DIOXIDE EMISSIONS FROM SOIL IN NERIS REGIONAL PARK / ANGLIES DVIDEGINIO EMISIJŲ IŠ DIRVOŽEMIO NERIES REGIONINIAME PARKE TYRIMAI IR VERTINIMAS / ИССЛЕДОВАНИЕ И ОЦЕНКА ВЫБРОСОВ ДВУОКИСИ УГЛЕРОДА ИЗ ПОЧВЫ В РЕГИОНАЛЬНОМ ПАРКЕ «НЕРИС»

2011 ◽  
Vol 19 (2) ◽  
pp. 115-122 ◽  
Author(s):  
Pranas Baltrėnas ◽  
Mantas Pranskevičius ◽  
Arvydas Lietuvninkas
Keyword(s):  
Carbon Dioxide ◽  
Research Methods ◽  
Carbon Dioxide Emissions ◽  
Co2 Emission ◽  
Gas Analysis ◽  
Field Conditions ◽  
Measuring Instrument ◽  
Agricultural Ecosystems ◽  
Co2 Balance ◽  
Analysis System

Soils release around 20% of the total CO2 content to the atmosphere; consequently, forest and agricultural ecosystems have a big influence on CO2 balance. Until recently, the majority of CO2 measurements of Lithuanian soils were either carried out under laboratory conditions or obtained by applying outdated research methods. CO2 investigations in Neris Regional Park were carried out under field conditions during plant vegetation by using the CO2 emission measuring instrument ADC BioScientific and soil chamber, the analysis system of which includes a metal collar of ∼0.9 m2 area. This infrared gas analysis system performs measurements within the range of 0–2000 ppm, with an error of 1 ppm. The emission's error is a mere ±2%. The system allows making reliable measurements within the temperature range of −5 °C to +50 °C. Santrauka Apie 20% viso CO2 kiekio, patenkančio įatmosferą, išskiria dirvožemiai, todėl miškų bei agroekosistemos daro nemažįtaką CO2 balansui. Lietuvoje iki pastarųjų metų dirvožemio CO2 matavimai daugeliu atveju buvo atliekami laboratorinėmis sa˛lygomis, arba duomenys surinkti taikant senstelėjusius tyrimų metodus. CO2tyrimai Neries regioniniame parke atlikti lauko sąlygomis augalų vegetacijos metu matuojant ADC BioScientific CO2 emisijos matuokliu. Šios infraraudonųjų spindulių dujų analizavimo sistemos skalė 0–2000 ppm, paklaida 1 ppm. Emisijos paklaida tesudaro ±2%. Matavimai šiuo prietaisu patikimi −5–+50 °C temperatūroje. Резюме Около 20% CO2 от общего объема попадает в атмосферу из почвы, поэтому столь велико влияние лесов и агроэкосистем на баланс CO2. В Литве измерения эмиссий CO2 с поверхности почв проводились в лабораторных условиях либо применялись старые методы исследования. В региональном парке «Нерис» эмиссии CO2 с поверхности почв измерялись новым прибором ADC BioScientific. Для исследований применялся прибор с системой инфракрасного газового анализа по шкале от 0 до 2000 частей на миллион. Выбросы учитывались с погрешностью ±2%. Устройство позволяет надежно измерять эмиссии CO2 в диапазоне температур от −5 °C до +50 °C.

The Effects of Drought on Leaf Gas Exchange and Growth of Three Species of Herbaceous Perennials

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540a-540
Author(s):  
K.J. Prevete ◽  
R.T. Fernandez
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Drought Tolerance ◽  
Transpiration Rate ◽  
Leaf Gas Exchange ◽  
Gas Analysis ◽  
Herbaceous Perennials ◽  
Effects Of Drought ◽  
Analysis System

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.

Validation of transcutaneous carbon dioxide monitoring using an artificial lung during adult pulsatile cardiopulmonary bypass

2021 ◽  
pp. 039139882098785
Author(s):  
Lawrence Garrison ◽  
Jeffrey B Riley ◽  
Steve Wysocki ◽  
Jennifer Souai ◽  
Hali Julick
Keyword(s):  
Carbon Dioxide ◽  
Cardiopulmonary Bypass ◽  
Gold Standard ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Artificial Lung ◽  
Blood Gas ◽  
Median Difference ◽  
Transcutaneous Carbon Dioxide ◽  
Arterial Blood

Measurements of transcutaneous carbon dioxide (tcCO2) have been used in multiple venues, such as during procedures utilizing jet ventilation, hyperbaric oxygen therapy, as well as both the adult and neo-natal ICUs. However, tcCO2 measurements have not been validated under conditions which utilize an artificial lung, such cardiopulmonary bypass (CPB). The purpose of this study was to (1) validate the use of tcCO2 using an artificial lung during CPB and (2) identify a location for the sensor that would optimize estimation of PaCO2 when compared to the gold standard of blood gas analysis. tcCO2 measurements ( N = 185) were collected every 30 min during 54 pulsatile CPB procedures. The agreement/differences between the tcCO2 and the PaCO2 were compared by three sensor locations. Compared to the earlobe or the forehead, the submandibular PtcCO2 values agreed best with the PaCO2 and with a median difference of –.03 mmHg (IQR = 5.4, p < 0.001). The small median difference and acceptable IQR support the validity of the tcCO2 measurement. The multiple linear regression model for predicting the agreement between the submandibular tcCO2 and PaCO2 included the SvO2, the oxygenator gas to blood flow ratio, and the native perfusion index ( R2 = 0.699, df = 1, 60; F = 19.1, p < 0.001). Our experience in utilizing tcCO2 during CPB has demonstrated accuracy in estimating PaCO2 when compared to the gold standard arterial blood gas analysis, even during CO2 flooding of the surgical field.

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