Search results for "CO2"
showing 10 items of 402 documents
Water-use efficiency and transpiration across European forests during the Anthropocene
2015
Considering the combined effects of CO2 fertilization and climate change drivers on plant physiology leads to a modest increase in simulated European forest transpiration in spite of the effects of CO2-induced stomatal closure. The Earth’s carbon and hydrologic cycles are intimately coupled by gas exchange through plant stomata1,2,3. However, uncertainties in the magnitude4,5,6 and consequences7,8 of the physiological responses9,10 of plants to elevated CO2 in natural environments hinders modelling of terrestrial water cycling and carbon storage11. Here we use annually resolved long-term δ13C tree-ring measurements across a European forest network to reconstruct the physiologically driven r…
Er det sammenheng mellom oppvarmet CO2 gass, postoperative smerter og hypotermi ved laparaskopiske inngrep? : en kvantitativ undersøkelse
2016
Masteroppgave i spesialsykepleie – Universitetet i Agder 2016 Background: A common complication to laparoscopic procedures is postoperative shoulder pain. As a result of a surgical procedure, the patient is also exposed to hypothermia. There are various theories of the causes of postoperative shoulder pain and hypothermia. One of them suggest that the internal environment in the abdomen changes by insufflation of standard CO2 gas, and that this may result in peritoneal changes. Previous studies show that heated CO2 gas can reduce postoperative pain and hypothermia by laparoscopic surgery. Surgical and intensive patient is in a vulnerable situation, and the reflection on the operation and in…
Keski-Suomen maakunnan kasvihuonekaasupäästöt ja niiden kehitys 2000-luvulla
2010
Keski-Suomen maakuntahallitus on kansallisen ilmasto- ja energiastrategian mukaisesti käynnistänyt keväällä 2010 maakunnan ilmastostrategiatyön, jossa etsitään keinoja ilmastonmuutoksen hillintään ja ilmastonmuutokseen sopeutumiseen. Jotta tavoitteita ja toimenpiteitä voidaan näille asettaa, on tunnettava alueen nykytila ja hahmotettava meneillään oleva kehityssuunta. Tämän tutkimuksen tavoitteena oli selvittää Keski-Suomen maakunnan ihmisperäisten kasvihuonekaasupäästöjen nykyiset lähteet, päästöjen määrä ja niiden kehitys eri sektoreilla 2000-luvulla sekä arvioida päästöjen vähennyskeinoja. Keski-Suomessa syntyi kasvihuonekaasupäästöjä talouskasvun vuosina 2004 ja 2006 noin 3,0 miljoonaa …
Ogļskābās gāzes CO2 ietekme uz cilvēka kognitīvajām spējām
2020
Ogļskābā gāze (CO2) ir neredzama un nejūtama gāze, ar kuru cilvēki sastopas ikdienā gan iekštelpās, gan ārpus tām. Īpaša uzmanība ogļskābajai gāzei jāpievērš tieši iekštelpās, jo, vairākiem cilvēkiem atrodoties telpā vienlaikus, tās koncentrācija gaisā strauji pieaug. Pastāv aizdomas par CO2 ietekmi uz cilvēka kognitīvajām spējām. Līdzšinējie pētījumi norāda, ka ogļskābajai gāzei ir ietekme uz cilvēka kognitīvajām spējām. Tomēr pētījumu rezultāti ir dažādi. Dažos pētījumos šī ietekme ir negatīva, citos – pozitīva, vēl citos šī ietekme netiek novērota. Šī pētījuma mērķis ir noskaidrot, vai ogļskābā gāze ietekmē cilvēka kognitīvās spējas. Pētījumā piedalījās 34 dalībnieki, LU PPMF 2. psiholoģ…
Extraction of lapachol from Tabebuia avellanedae wood with supercritical CO2: an alternative to Soxhlet extraction?
2003
The solubility of lapachol in supercritical CO2 was determined at 40°C and pressures between 90 and 210 bar. Supercritical fluid extraction of lapachol and some related compounds by CO2 from Tabebuia avellanedae wood is compared to Soxhlet extraction with different solvents. A standard macroscale (100-200 g wood) and a microscale (~10 mg wood) experimental setup are described and their results are compared. The latter involved direct spectrophotometric quantification in a high-pressure autoclave with an integrated optical path and a magnetic stirrer, fitted directly into a commercial spectrophotometer. The relative amount of lapachol extracted by supercritical CO2 at 40°C and 200 bar was ab…
Elevated CO2 emissions during magmatic-hydrothermal degassing at Awu Volcano, Sangihe Arc, Indonesia
2020
Awu is a remote and little known active volcano of Indonesia located in the northern part of Molucca Sea. It is the northernmost active volcano of the Sangihe arc with 18 eruptions in less than 4 centuries, causing a cumulative death toll of 11,048. Two of these eruptions were classified with a Volcanic Explosivity Index (VEI) of 4. Since 2004, a lava dome has occupied the centre of Awu crater, channelling the fumarolic gas output along the crater wall. A combined Differential Optical Absorption Spectroscopy (DOAS) and Multi-component Gas Analyzer System (Multi-GAS) study highlight a relatively small SO2 flux (13 t/d) sustained by mixed magmatic&ndash
Tunable diode laser measurements of hydrothermal/volcanic CO2 and implications for the global CO2 budget
2014
Quantifying the CO2 flux sustained by low-temperature fumarolic fields in hydrothermal/volcanic environments has remained a challenge, to date. Here, we explored the potential of a commercial infrared tunable laser unit for quantifying such fumarolic volcanic/hydrothermal CO2 fluxes. Our field tests were conducted between April 2013 and March 2014 at Nea Kameni (Santorini, Greece), Hekla and Krýsuvík (Iceland) and Vulcano (Aeolian Islands, Italy). At these sites, the tunable laser was used to measure the path-integrated CO2 mixing ratios along cross sections of the fumaroles' atmospheric plumes. By using a tomographic post-processing routine, we then obtained, for each manifestation, the co…
Carbon emissions by Ssouth american companies: driving factors for reporting decisions and emissions reduction
2018
In the last decade, companies have started to disclose information on carbon emissions. To our knowledge, this is the first paper to look into this phenomenon in South America, which is a very important geographical area regarding climate change because of the local nature and developing economies. This paper explores the relationships between some corporate variables and two important decisions: (i) whether to report carbon emissions, and (ii) the impact on the evolution of carbon emissions. Logit and linear panel data models are used to determine the driving factors for decisions (i) and (ii). Our results show that regarding the carbon reporting decision, a company&rsquo
Die CO 2 -Messung im Atemgas
1997
UNLABELLED Currently, even in prehospital emergency medicine (PEM), continuous end-tidal CO2 monitoring is frequently used as a sensitive and non-invasive technique in ventilated patients. Due to its central role, the continuous measurement of exhaled CO2 provides immediate information about the status of three essential functions of the organism: ventilation, circulation, and metabolism. METHODS Recent literature, obtained by a computer-guided search (Winspirs), and product information of all currently available capnometry devices were reviewed in detail. Firstly, the theoretical background of different CO2-measurement methods and techniques is described. Secondly, indications and specific…
TISSUE OXYGENATION AND TISSUE METABOLISM IN THE BRAIN CORTEX DURING PRONOUNCED ARTERIAL HYPOCAPNIA
1981
Publisher Summary This chapter describes the tissue oxygenation and tissue metabolism in the brain cortex during pronounced arterial hypocapnia. Acute arterial hypocapnia induced by hyperventilation leads to typical reactions in the circulation and the metabolism of the brain tissue. With a lowering of arterial CO2 tension, the cerebro-vascular resistance (CVR) increases resulting in a decrease of cerebral blood flow. The changes in CVR are a consequence of decreasing hydrogen ion and potassium ion concentrations in the perivascular space of the brain arterioles. The corresponding changes in the brain metabolism are characterized by elevated concentrations of lactate and pyruvate and an inc…