scholarly journals Technical Note: Validation of the GreenFeed System for measuring enteric gas emissions from cattle

2021 ◽  
Author(s):  
Sean M McGinn ◽  
Jean-Franҫois Coulombe ◽  
Karen A Beauchemin
Keyword(s):  
Co2 Emission ◽  
Emission Rate ◽  
Technical Note ◽  
Emission Rates ◽  
Gas Emissions ◽  
Respiration Chamber ◽  
The Difference ◽  
Carbon Dioxide Co2 ◽  
Offset Error ◽  
Measurement Period

Abstract There are knowledge gaps in animal agriculture on how to best mitigate greenhouse gas emissions while maintaining animal productivity. One reason for these gaps is the uncertainties associated with methods used to derive emission rates. This study compared emission rates of methane (CH4) and carbon dioxide (CO2) measured by a commercially available GreenFeed (GF) system to those from 1) a mass flow controller (MFC) that released known quantities of gas over time (i.e., emission rate), and 2) a respiration chamber (RC). The GF and MFC differed by only 1% for CH4 (P = 0.726) and 3% for CO2 (P = 0.013). The difference between the GF and RC was 1% (P = 0.019) for CH4 and 1% for CO2 (P = 0.007). Further investigation revealed that the difference in emission rate for CO2 was due to a small systematic offset error indicating a correction factor could be applied. We conclude that the GF system accurately estimated enteric CH4 and CO2 emission rates of cattle over a short measurement period, but additional factors would need to be considered in determining the 24-h emission rate of an animal.

scholarly journals Comparison of CO2 Emissions from Vehicles in Thailand

2017 ◽  
pp. 65-74 ◽  
Author(s):  
Sutthicha Nilrit ◽  
Pantawat Sampanpanish ◽  
Surat Bualert
Keyword(s):  
Co2 Emissions ◽  
Co2 Emission ◽  
Emission Rate ◽  
Vehicle Speed ◽  
Emission Rates ◽  
Passenger Vehicles ◽  
Light Duty ◽  
Liquid Petroleum Gas ◽  
Heavy Duty Diesel ◽  
Carbon Dioxide Co2

Emission of carbon dioxide (CO2), a greenhouse gas, from typical passenger vehicles in Thailand was investigated using a chassis dynamometer in the Automotive Emission Laboratory. The vehicle running method was controlled under the standard Bangkok driving cycle. CO2 emissions were measured at three different speeds for the following four vehicle types commonly used in Thailand: heavy duty diesel (HDD), light duty diesel (LDD), and light duty gasoline (LDG) vehicles and motorcycles (MC). HDD vehicles had the highest average CO2 emission rate, followed by LDD, LDG and MC at 1,198.8±93.1, 268.4±21.3, 166.1±27.7 and 42.5±6.1 g km-1, respectively; all values were significantly different (p < 0.05) from each other. The effect of different fuel types, including diesel, gasoline 91, gasohol 95, gasohol 91, liquid petroleum gas (LPG) and natural gas for vehicles (NGV), on the CO2 emission level was also compared. HDD vehicles had a higher rate of CO2 emission when using either NGV or diesel, while LDD vehicles emitted more CO2 with diesel than with NGV. For LDG vehicles, more CO2 was emitted with gasohol 91 than with gasohol E20, LPG or NGV. Finally, MC had a higher average CO2 emission rate with gasohol 95 than with gasoline 91 and gasohol 91 at any vehicle speed. The CO2 emission rates obtained in this study can be used as a basis to create a database that supports development of an efficient transportation management system and reduced vehicular emission of greenhouse gases in Thailand.

scholarly journals The assessment of nuclear hydrogen cogeneration system (NHCS) for CO2 conversion to urea fertilizer

2020 ◽  
Vol 16 (2) ◽  
pp. 135-139
Author(s):  
Djati Hoesen Salimy ◽  
Sriyono Sriyono ◽  
Elfrida Saragi ◽  
Abdul Hafid
Keyword(s):  
Co2 Emission ◽  
Power Plants ◽  
Emission Rate ◽  
Heat Energy ◽  
Co2 Conversion ◽  
Urea Fertilizer ◽  
Nuclear Heat ◽  
Cogeneration System ◽  
Carbon Dioxide Co2 ◽  
Environmentally Friendly Approach

This paper reviews the application of a nuclear hydrogen cogeneration system (NHCS) for conversion of carbon dioxide (CO2) to urea fertilizer. The NHCS is powered by high temperature gas cooled reactor (HTGR)with 2x600 MWt which is sufficient to produce hydrogen and heat energy to convert CO2 from coal-fired power plants with a power of 90 MWe to urea fertilizer of 1725 tons per day. As a source CO2, a coal-fired power plant is built near NHCS. Compared to conventional fertilizer plant, the NHCS application can save natural gas by 21.25x106 MMBTU/year, with a potential reduction in CO2 emission rate of 1.66x106 tons/year. Besides, there is still nuclear heat remaining at about 425.65 MWt which is equivalent to 140.46 MWe of electricity, and 90 MWe of electricity from coal-fired power plants that can be connected to electric grid. The paper also discusses the significance of the combination of NHCS and the technology of CO2 conversion which is expected to play an important role in the industry in the future  as an environmentally friendly approach.

scholarly journals Questioning paradigms: caste-specific ventilation in harvester ants, Messor pergandei and M. julianus (Hymenoptera: Formicidae)

1995 ◽  
Vol 198 (2) ◽  
pp. 521-530 ◽  
Author(s):  
J Lighton ◽  
D Berrigan
Keyword(s):  
Co2 Emission ◽  
Emission Rate ◽  
Emission Rates ◽  
Colony Foundation ◽  
Harvester Ants ◽  
Developmental Constraints ◽  
Ant Colonies ◽  
Physiological Constraints ◽  
Harvester Ant ◽  
Single Temperature

Do developmental constraints in ant colonies limit gas exchange strategies to those displayed by female alates (presumptive queens)? In the xeric harvester ant genus Messor, we found that M. pergandei and M. julianus female alates ventilated highly discontinuously, as predicted, but M. julianus workers ventilated less discontinuously and M. pergandei workers (which occur in more xeric habitats) ventilated continuously. We present the salient characteristics of the discontinuous ventilation cycles of the species and the manner in which they are modulated by CO2 emission rates at a single temperature (24 &deg;C). We demonstrate that, in M. julianus workers, open-spiracle phase CO2 emission rate only slightly exceeds overall CO2 emission rate, making discontinuous ventilation marginal, a state extrapolated in M. pergandei to continuous ventilation. However, workers are plainly capable of far greater rates of CO2 emission than when inactive at 24 &deg;C, so the lack of discontinuous ventilation in M. pergandei under normoxic conditions is not likely to be imposed by physiological constraints and may, in fact, be a response to its xeric environment. We hypothesize &shy; aside from phylogenetic effects &shy; that discontinuous ventilation occurs primarily in insects that may experience hypoxic and hypercapnic conditions, such as ant queens during claustral colony foundation and perhaps workers within the nest environment; that discontinuous ventilation is not necessarily essential to reduce respiratory water loss; and that it will not necessarily occur in castes or species routinely exposed to xeric but normoxic conditions.

Calculation of CH4 and CO2 Emission Rate in Kahrizak Landfill Site with Land GEM Mathematical Model

2014 ◽  
Author(s):  
Mohammad Hossein Ahmadi ◽  
Farideh Atabi ◽  
Mehdi Ali Ehyaei
Keyword(s):  
Mathematical Model ◽  
Co2 Emission ◽  
Emission Rate ◽  
Landfill Site

scholarly journals Two Independent Light Dilution Corrections for the SO2 Camera Retrieve Comparable Emission Rates at Masaya Volcano, Nicaragua

2021 ◽  
Vol 13 (5) ◽  
pp. 935
Author(s):  
Matthew Varnam ◽  
Mike Burton ◽  
Ben Esse ◽  
Giuseppe Salerno ◽  
Ryunosuke Kazahaya ◽  
...  
Keyword(s):  
Light Scattering ◽  
Optical Depth ◽  
Camera Calibration ◽  
Wind Direction ◽  
Emission Rate ◽  
Emission Rates ◽  
Depth Images ◽  
Masaya Volcano ◽  
Rapid Changes ◽  
Volcanic Emission

SO2 cameras are able to measure rapid changes in volcanic emission rate but require accurate calibrations and corrections to convert optical depth images into slant column densities. We conducted a test at Masaya volcano of two SO2 camera calibration approaches, calibration cells and co-located spectrometer, and corrected both calibrations for light dilution, a process caused by light scattering between the plume and camera. We demonstrate an advancement on the image-based correction that allows the retrieval of the scattering efficiency across a 2D area of an SO2 camera image. When appropriately corrected for the dilution, we show that our two calibration approaches produce final calculated emission rates that agree with simultaneously measured traverse flux data and each other but highlight that the observed distribution of gas within the image is different. We demonstrate that traverses and SO2 camera techniques, when used together, generate better plume speed estimates for traverses and improved knowledge of wind direction for the camera, producing more reliable emission rates. We suggest combining traverses and the SO2 camera should be adopted where possible.

Relationship Between Gas Emissions and Dry Matter Intake in Mature Angus Cows

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 32-33
Author(s):  
Amanda Holder ◽  
Megan A Gross ◽  
Alexi Moehlenpah ◽  
Paul Beck
Keyword(s):  
Dry Matter ◽  
Significant Positive Correlation ◽  
Crossover Design ◽  
Dry Matter Intake ◽  
Data Set ◽  
Gas Emissions ◽  
Positive Correlation ◽  
Wide Range ◽  
Carbon Dioxide Co2 ◽  
Second Period

Abstract The objective of this study was to examine the effects of diet quality on greenhouse gas emissions and dry matter intake (DMI). We used 42 mature, gestating Angus cows (600±69 kg; and BSC 5.3±1.1) with a wide range in DMI EPD (-1.36 to 2.29). Cows were randomly assigned to 2 diet sequences forage-concentrate (FC) or concentrate-forage(CF) determined by the diet they consumed in each period (forage or concentrate). The cows were adapted to the diet and the SmartFeed individual intake units for 14 d followed by 45 d of intake data collection for each period. Body weight was recorded on consecutive weigh days at the beginning and end of each period and then once every two wk for the duration of a period. Cows were exposed to the GreenFeed Emission Monitoring (GEM) system for no less than 9 d during each period. The GEM system was used to measure emissions of carbon dioxide (CO2) and methane (CH4). Only cows with a minimum of 20 total &gt;3-m visits to the GEM were included in the data set. Data were analyzed in a crossover design using GLIMMIX in SASv.9.4. Within the CF sequence there was a significant, positive correlation between TMR DMI and CH4 (r=0.81) and TMR DMI and CO2 (r=0.69), however, gas emissions during the second period on the hay diet were not correlated with hay intake. There was a significant, positive correlation between hay DMI and CO2 (r=0.76) and hay DMI and CH4 (r=0.74) when cows first consumed forage (FC). In comparison to the CF sequence, cows on the FC sequence showed a positive correlation between CO2 and TMR DMI during the second period. There was also a significant positive correlation between hay and TMR DMI when assessed across (r=0.43) or within sequence (FC r=0.41, CF r=0.47).

scholarly journals Analyzing the Renewable Energy and CO2 Emission Levels Nexus at an EU Level: A Panel Data Regression Approach

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 130
Author(s):  
Mihail Busu ◽  
Alexandra Catalina Nedelcu
Keyword(s):  
Renewable Energy ◽  
Panel Data ◽  
Co2 Emissions ◽  
Co2 Emission ◽  
Negative Impact ◽  
National Level ◽  
Renewable Energy Consumption ◽  
Urbanization Level ◽  
Carbon Dioxide Co2 ◽  
The Impact

In the past decades, carbon dioxide (CO2) emissions have become an important issue for many researchers and policy makers. The focus of scientists and experts in the area is mainly on lowering the CO2 emission levels. In this article, panel data is analyzed with an econometric model, to estimate the impact of renewable energy, biofuels, bioenergy efficiency, population, and urbanization level on CO2 emissions in European Union (EU) countries. Our results underline the fact that urbanization level has a negative impact on increasing CO2 emissions, while biofuels, bioenergy production, and renewable energy consumption have positive and direct impacts on reducing CO2 emissions. Moreover, population growth and urbanization level are negatively correlated with CO2 emission levels. The authors’ findings suggest that the public policies at the national level must encourage the consumption of renewable energy and biofuels in the EU, while population and urbanization level should come along with more restrictions on CO2 emissions.

scholarly journals Photosynthesis and Related Physiological Parameters Differences Affected the Isoprene Emission Rate among 10 Typical Tree Species in Subtropical Metropolises

2021 ◽  
Vol 18 (3) ◽  
pp. 954
Author(s):  
Junyao Lyu ◽  
Feng Xiong ◽  
Ningxiao Sun ◽  
Yiheng Li ◽  
Chunjiang Liu ◽  
...  
Keyword(s):  
Photosynthetic Rate ◽  
Tree Species ◽  
Urban Areas ◽  
Emission Rate ◽  
Intercellular Co2 Concentration ◽  
Co2 Concentration ◽  
Single Species ◽  
Photosynthetic Parameters ◽  
Emission Rates ◽  
Isoprene Emission

Volatile organic compound (VOCs) emission is an important cause of photochemical smog and particulate pollution in urban areas, and urban vegetation has been presented as an important source. Different tree species have different emission levels, so adjusting greening species collocation is an effective way to control biogenic VOC pollution. However, there is a lack of measurements of tree species emission in subtropical metropolises, and the factors influencing the species-specific differences need to be further clarified. This study applied an in situ method to investigate the isoprene emission rates of 10 typical tree species in subtropical metropolises. Photosynthesis and related parameters including photosynthetic rate, intercellular CO2 concentration, stomatal conductance, and transpiration rate, which can influence the emission rate of a single species, were also measured. Results showed Salix babylonica always exhibited a high emission level, whereas Elaeocarpus decipiens and Ligustrum lucidum maintained a low level throughout the year. Differences in photosynthetic rate and stomatal CO2 conductance are the key parameters related to isoprene emission among different plants. Through the establishment of emission inventory and determination of key photosynthetic parameters, the results provide a reference for the selection of urban greening species, as well as seasonal pollution control, and help to alleviate VOC pollution caused by urban forests.

Log landings are methane emission hotspots in managed forests

2021 ◽  
Author(s):  
Juliana Vantellingen ◽  
Sean C. Thomas
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Management Practices ◽  
Emission Rate ◽  
Woody Debris ◽  
Organic Matter Content ◽  
Growing Season ◽  
Matter Content ◽  
Emission Rates ◽  
Managed Forests

Log landings are areas within managed forests used to process and store felled trees prior to transport. Through their construction and use soil is removed or redistributed, compacted, and organic matter contents may be increased by incorporation of wood fragments. The effects of these changes to soil properties on methane (CH<sub>4</sub>) flux is unclear and unstudied. We quantified CH<sub>4</sub> flux rates from year-old landings in Ontario, Canada, and examined spatial variability and relationships to soil properties within these sites. Landings emitted CH<sub>4</sub> throughout the growing season; the average CH<sub>4</sub> emission rate from log landings was 69.2 ± 12.8 nmol m<sup>-2</sup> s<sup>-1</sup> (26.2 ± 4.8 g CH<sub>4</sub> C m<sup>-2</sup> y<sup>-1</sup>), a rate comparable to CH<sub>4</sub>-emitting wetlands. Emission rates were correlated to soil pH, organic matter content and quantities of buried woody debris. These properties led to strong CH<sub>4</sub> emissions, or “hotspots”, in certain areas of landings, particularly where processing of logs occurred and incorporated woody debris into the soil. At the forest level, emissions from landings were estimated to offset ~12% of CH<sub>4</sub> consumption from soils within the harvest area, although making up only ~0.5% of the harvest area. Management practices to avoid or remediate these emissions should be developed as a priority measure in “climate-smart” forestry.

scholarly journals Variations of the 630.0 nm airglow emission with meridional neutral wind and neutral temperature around midnight

2018 ◽  
Vol 36 (5) ◽  
pp. 1471-1481
Author(s):  
Chih-Yu Chiang ◽  
Sunny Wing-Yee Tam ◽  
Tzu-Fang Chang
Keyword(s):  
Emission Rate ◽  
Local Maximum ◽  
Neutral Wind ◽  
Emission Rates ◽  
Emission Layer ◽  
Neutral Winds ◽  
Neutral Temperature ◽  
Bright Spots ◽  
Different Temperatures ◽  
Volume Emission

Abstract. The ISUAL payload onboard the FORMOSAT-2 satellite has often observed airglow bright spots around midnight at equatorial latitudes. Such features had been suggested as the signature of the thermospheric midnight temperature maximum (MTM) effect, which was associated with temperature and meridional neutral winds. This study investigates the influence of neutral temperature and meridional neutral wind on the volume emission rates of the 630.0 nm nightglow. We utilize the SAMI2 model to simulate the charged and neutral species at the 630.0 nm nightglow emission layer under different temperatures with and without the effect of neutral wind. The results show that the neutral wind is more efficient than temperature variation in affecting the nightglow emission rates. For example, based on our estimation, it would require a temperature change of 145 K to produce a change in the integrated emission rate by 9.8 km-photons cm−3 s−1, while it only needs the neutral wind velocity to change by 1.85 m−1 s−1 to cause the same change in the integrated emission rate. However, the emission rate features a local maximum in its variation with the temperature. Two kinds of tendencies can be seen regarding the temperature that corresponds to the turning point, which is named the turning temperature (Tt) in this study: firstly, Tt decreases with the emission rate for the same altitude; secondly, for approximately the same emission rate, Tt increases with the altitude.

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