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  • 1
    Publication Date: 2024-01-22
    Description: Natural gas is considered a bridging technology in the energy transition because it produces fewer carbon emissions than coal, for example. However, when leaks exist, methane is released into the atmosphere, leading to a dramatic increase in the carbon footprint of natural gas, as methane is a much stronger greenhouse gas than carbon dioxide. Therefore, we conducted a detailed study of methane emissions from gas‐powered end‐use appliances and then compared their climate impacts with those of electricity‐powered appliances. We used the Munich Oktoberfest as a case study and then extended the study to 25 major natural gas consuming countries. This showed that electricity has been the more climate‐friendly energy source at Oktoberfest since 2005, due to the extensive use of renewable electricity at the festival and the presence of methane emissions, particularly caused by the incomplete combustion and leakages of natural gas in cooking and heating appliances. By contrast, at the global level, our study shows that natural gas still produces lower carbon emissions for end‐user appliances than electricity in 18 of the 25 countries studied. However, as the share of renewable energy in the electricity mix steadily increases in most countries, the carbon footprint of electricity will be lower than that of natural gas in these countries in the near future. These findings from our comparison of the total carbon emissions of electric and gas‐powered end‐use appliances can help inform the debate on how to effectively address climate change.
    Description: Plain Language Summary: Although natural gas is considered a relatively climate‐friendly energy source compared to coal, leakage of methane, the main component of natural gas, can significantly increase the climate impact of natural gas. This is because methane is a very strong greenhouse gas. In this study, we focused on methane leakage from end‐use appliances used for cooking and heating. Using the Munich Oktoberfest as a case study, we found that these end‐use appliances produce significant methane emissions. Therefore, we investigated at which leakage rates and which electricity mixes it would be better to use electric appliances for cooking and heating instead to reduce overall carbon emissions. We found that despite leakage rates, natural gas is still more climate‐friendly than electricity in most countries around the world. However, as the share of renewable energy in the electricity mix increases in most countries, electricity is becoming a more climate‐friendly energy source every year. With this study, we want to make people aware of how the climate friendliness of electricity compares to natural gas over time.
    Description: Key Points: Methane emissions at Oktoberfest are measured and classified as natural gas‐based using isotopic analysis and the ratio of ethane to methane. Oktoberfest could save 87% of total carbon emissions from energy consumption if all gas‐powered appliances were replaced with electric ones. We aim to make people aware how the carbon footprint of electric and natural gas‐driven end‐user appliances compares and evolves over time.
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: ETH Zürich Foundation http://dx.doi.org/10.13039/501100012652
    Description: Technical University of Munich–Institute for Advanced Study
    Description: German Excellence Initiative
    Description: European Union Seventh Framework Programme
    Description: https://doi.org/10.14459/2022mp1663551
    Description: https://github.com/ankitshekhar99/Oktoberfest2019Study/tree/main
    Keywords: ddc:333.7 ; climate change ; methane ; carbon dioxide ; emissions ; carbon mitigation ; global
    Language: English
    Type: doc-type:article
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    The journal of membrane biology 13 (1973), S. 61-78 
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Incubation of the free living soil amoebaAcanthamoeba castellanii with lysolecithins results in aggregation of the cells into multicellular masses. The cells in these masses form close junctions and are electrically coupled. Our data support the hypothesis that specialized membrane regions like gap and/or tight junctions constitute a site of electrical coupling between cells. The possible role of lysophospholipids within the phenomenon of cell communication is discussed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    The journal of membrane biology 7 (1972), S. 88-110 
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The electrical coupling of epithelial cells of the intestine of chick embryo cultured in monolayers was studied. This coupling can be evaluated by regarding the monolayer as a honeycomb structure of cells and the cells as equipotential spaces, as long as the cells are small (diameter 〈25μm). With help of this discrete model it was found that for the non-junctional membrane the membrane resistance isϱ m =250−2,000 Ω cm2, and for the junctional membraneϱ m =5−50 Ω cm2. In addition to this discrete model, a continuous model was also considered and good agreement between the two descriptions was found. With the aid of the continuous model, a value for the non-junctional membrane capacitance (C m ) was obtained: 5–50 μF/cm2. The electrical values are not corrected for membrane folding, microvilli and the like. Tentative corrections based on electron microscopy suggest: 1,000 〈ϱ m 〈 10,000 Ω cm2, 10 〈ϱ m 〈 100 Ω cm2, 1〈C m 〈 10 μF/cm2
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary In this paper, discrete as well as continuous models are developed to enable accurate interpretations of experimental findings of electrical cell coupling in the salivary gland of the larva ofDrosophila hydei. With the help of these models it is possible to determine the nonjunctional and junctional membrane resistance as well as the confidence interval of these estimates. Apart from the easy culture of larvae and large diameters of the cells, the distal part of the salivary gland proves to be an excellent object for studying electrical cell coupling in a quantitative way. It is found that there are differences between electrical parameters in the proximal part and in the distal part of the gland. Furthermore, the value of the junctional resistance appears to be dependent on the age of the gland. Using the model descriptions, the influence of lysolecithin upon the electrical cell coupling is estimated in a quantitative way. It is demonstrated that lysolecithin, if added to the surrounding fluid, produces in a reversible way an increase in the nonjunctional permeability and a decrease in junctional permeability. No changes in membrane capacity were observed.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Biological cybernetics 65 (1991), S. 227-234 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract A mathematical muscle model is presented that relates neural control signals linearly to muscle force without violating important known physiological constraints, such as the size-principle (Henneman and Mendell 1981) and non-linear twitch summation (Burke et al. 1976). This linearity implies that the neural control signals (defined as a weighted sum of activities in a nerve bundle) can be interpreted as the internal representation of total muscle force. The model allows for different relative contributions from the two force-grading mechanisms, i.e. the recruitment of motor units and the modulation of their firing frequency. It can therefore be applied to a variety of (distal and proximal) muscles. Furthermore, it permits simple mechanisms for controlling muscle force, e.g. in superposed motor tasks. The model confirms our intuitive notion that a weighted sum of activities in a nerve bundle can directly represent an external controlled variable, which in this case is exerted muscle force.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Biological cybernetics 15 (1974), S. 159-178 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract The hypothesis that the properties of the stretch reflex could be changed dependent on the appointed task of the motor system was tested by measuring the mechanical output impedance of the hand of a human subject. Small disturbing torques were exerted on the hand rotating in the wrist joint in palmar and dorsal direction. The angular position, velocity and acceleration were recorded during 180 msec after the start of the disturbing torque. Within the linear range differences were found between the situations that (1) the subject kept his hand in a fixed position (posture) and (2) the subject tracked a simple and slow moving target (tracking). A simple model of the peripheral part of the motor system with the spinal reflex mechanism was made to analyse the responses. With the help of this model the changes in the reflex sensors were distinguished from changes in the mechanical system of the hand with the muscles attached to it and from changes in the effect of an activation of the muscle. During posture the responses were affected by the attention of the subject. An important part of these changes was a shift in the delay time of the reflex. During tracking the responses changed markely dependent on the velocity of the hand. When this velocity is larger than about 0.05 rad.sec−1 then the strength of the reflex is approximately suppressed to about a half of the value during posture. Above this velocity the mechanical system of the hand with the muscles attached to it appeared to be less damped. The suppression of the reflex is caused by a decrease of the gain of the feedback sensors to about a third and an increase in the gain of the system of muscles with their load to about one and a half. It was concluded that the gain of the feedback sensors is controlled by signals from supraspinal levels.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 22 (1996), S. 359-366 
    ISSN: 1432-0789
    Keywords: Methane emission ; Methane oxidation ; Methyl fluoride ; Plant-mediated gas transport ; Rice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Oxidation of CH4 in the rhizosphere of rice plants was quantified using (1) methyl fluoride, a specific inhibitor of CH4 oxidation, and (2) measuring changes in plant-mediated CH4 emission after incubation under air, N2, or 40% O2. No significant rhizospheric CH4 oxidation was observed from rice plants in the ripening stage. CH4 emission from rice plants 1 week before panicle initiation increased by 40% if CH4 oxidation in the rhizosphere was blocked. The growth stage of the rice plant is an important factor determining the rhizospheric CH4 oxidation. Fluctuation of rhizospheric CH4 oxidation during the growing season may help to explain the observed seasonal CH4 emission patterns in field studies. Measurements from four rice varieties showed that one variety, Pokkali, had higher rhizospheric CH4 oxidation. This was probably because Pokkali was in an earlier growth stage than the other three varieties. Both in the early and in the late growth stages, incubation under N2 caused a much stronger CH4 flux than inhibition of CH4 oxidation alone. Apparently, N2 incubation not only blocked CH4 oxidation but also stimulated methanogenesis in the rhizosphere. Incubation under a higher O2 atmosphere (40% O2) than ambient air decreased the CH4 flux, suggesting that increasing the oxidation of the rice rhizosphere may help in reducing CH4 fluxes from rice agriculture. The O2 pressure in the rhizosphere is an important factor that reduces the plant-mediated CH4 flux. However, inhibition of methanogenesis in the rhizosphere may contribute more to CH4 flux reduction than rhizospheric CH4 oxidation.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 394 (1975), S. 620-632 
    ISSN: 0005-2736
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 211 (1970), S. 98-101 
    ISSN: 0005-2736
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We investigated the influence of the presence of oxygen during the deposition of the calcium cathode on the structure and on the performance of polymeric light emitting diodes (pLEDs). The oxygen background pressure during deposition of the calcium cathode of polymeric LEDs was varied. Subsequently, the oxygen depth distribution was measured and correlated with the performance of the pLEDs. The devices have been fabricated in a recently built ultraclean setup. The polymer layers of the pLEDs have been spincoated in a dry nitrogen atmosphere and transported directly into an ultrahigh vacuum chamber where the metal electrodes have been deposited by evaporation. We used indium–tin–oxide as anode, OC1C10 PPV as electroluminescent polymer, calcium as cathode, and aluminum as protecting layer. We achieved reproducibility of about 15% in current and brightness for devices fabricated in an oxygen atmosphere of (very-much-less-than)10−9 mbar. For further investigations the calcium deposition was carried out in an oxygen atmosphere from 10−8 to 10−5 mbar. We determined the amount of oxygen in the different layers of the current–voltage-light characterized pLEDs with elastic recoil detection analysis and correlated it with the characteristics of the devices. The external efficiency of the pLEDs decreases continuously with increasing oxygen pressure, the current shows a pronounced minimum. The brightness mostly decreases with increasing oxygen with an indication of a slight minimum. PLEDs with completely oxidized calcium are not operational. The first contact of the pLEDs with the dry glove box environment leads to an immediate reduction of current and brightness which is caused by the cooling of the devices by several degrees. Determining reproducible characteristics of pLEDs in the vacuum requires the measurement of their temperature. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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