Increase In Emission Levels Research Articles

Mitigating poor environmental quality with technology, renewable and entrepreneur policies: A symmetric and asymmetric approaches

This is dual analysis of Turkish sustainable development amidst some high industrial and economic activities. Turkey is currently prioritizing the economic growth to the environmental sustainability and trying to achieve its 2023 goals and place in top 10 economies by date. This action might spark increase in emission level and decrease the environmental quality for both term. For effective and clear analysis, we apply the empirical analyses with both symmetric (dynamic ordinary least square-DOLS) and asymmetric (nonlinear autoregressive distributed lag-NARDL) approaches in short run and the long run periods for policy inferences through forecast. We apply the economic features (entrepreneurs, FDI, technological innovation proxy by R&D, renewable energy and economic growth) of Turkey that are important in determining both economic and environment development of the country to investigate its ability to achieve its climate goals. Turkey's data of 1985–2018 were adopted. Findings from both approaches (symmetric and asymmetric) show that carbon emission can be reduced and good environmental quality obtained through the instruments of renewable energy, technological innovation, FDI and entrepreneurial activities. A nexus is established among the instruments (renewable energy, technological innovation, entrepreneur activities and FDI) pointing towards carbon mitigation for Turkey, and this gives support to the findings from both symmetric and asymmetric approaches. Also, from symmetric analysis with dynamic ordinary least square, EKC is found for the case of Turkey which shows the ability of Turkey achieving its climate goal if right policies are implemented.

Benchmarking the embodied environmental impacts of the design parameters for asphalt mixtures

For the full abatement of road construction emissions and the enhancement of green public procurement, the embodied environmental and social impacts of asphalt mixture typologies must be better understood. Therefore, the aim of this paper was to explore the environmental impact of five key asphalt mixtures classes (dense-graded, gap-graded, open-graded, porous and stone mastic) and the influence of their design parameters. This was achieved through carrying out 160 life-cycle assessment case study simulations to explore the upper and lower bounds for key design parameters, such as granulometric curve, filler and bitumen content, and filler and bitumen type. Results identified dense-graded (AC) and stone mastic (SMA) mixtures were the most impacting, per tonne, and gap-graded (BBTM A) and stone mastic to be the most impacting per unit depth. Porous mixtures had the largest impact range. Higher traffic classes also would experience an increase in emission levels, due to the need for better, or modified, binders. Future work would require the application of these results to case study projects, to better understand current mixture and construction impacts and the influence of durability.

Effect of piston and cylinder head swirl generation techniques on the performance of ceiba pentandra and nigella sativa B20 biodiesel blended diesel engine operation

Biodiesels are renewable fuels and their usage in diesel engine can decrease the dependence on fossil-based fuels which are exhaustive in nature. Further they can effectively address the alarming increase in emission levels in the atmosphere and provide savings in the foreign exchange. The present work mainly focuses on the effect of swirl techniques adopted on the performance of the modified diesel engine powered with two B20 based biodiesels derived from Ceiba Pentandra (CPNTOME B20) and Nigella Sativa (NIZSAOME B20) respectively. The swirl techniques are adopted by suitable modifications on both the piston and cylinder head surfaces respectively. Optimized number of cavities on piston and cavities and domes on the cylinder head improved the diesel engine performance powered with selected biodiesel blended fuels. Accordingly, 6 number of cavities on the piston and 2 domes and 3 cavities on the cylinder head surfaces provided higher brake thermal break efficiency (BTE), lower hydrocarbons (HC), carbon monoxide (CO), smoke emissions while nitric oxide (NOx) emissions were increased for the diesel engine powered with two B20 blends compared to other swirl combinations used. Among the two biodiesels used CPNTOME B20 showed higher engine performance compared to NIZSAOME B20. BTE of engine fuelled with diesel increased by 4.86% and 6.54% respectively when compared with B20 blends of CPNTOME and NIZSAOME. Smoke emissions of engine fuelled with diesel decreased by 8.27% and 11.43% respectively when compared with B20 blends of CPNTOME and NIZSAOME.

Heterogeneous effects of temperature and emissions on economic productivity across climate regimes

The impact of climate change has resulted in several long-term events including extreme temperatures. Besides, the occurrence of climate events impedes economic progress––affecting economic readiness of climate mitigation. However, the effect of climatic factors on economic productivity has not been extensively covered in existing literature, especially among climate regimes. Here, we use sophisticated panel and time series techniques to examine the heterogeneous effects of temperature and emissions on income from 1960 to 2014. Our empirical results indicate a 1% rise in temperature declines income by 0.39% whereas 1% increase in emission levels stimulates income by 0.22%. This implies a mutual relationship between income and emissions––where environmental pollution supports wealth creation and vice versa. We find that a shift from optimal temperature levels to extreme patterns hamper economic productivity. Extreme temperatures affect heating and cooling degree days due to increased energy requirements, hence, escalating energy demand and emissions. With the agenda towards emission reduction, this study emphasizes economic structural change through transition from brown to green growth.

Methane emissions in triple rice cropping: patterns and a method for reduction

The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies because total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after the annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that avoiding rice straw incorporating into soil and decomposing rice straw in paddy surface-water reduces methane emissions.

Global climate impacts of agriculture: A meta-regression analysis of food production

Good management requires proper measurement, yet little is known about anthropogenic climate effects of agriculture. To remedy this, a precise measurement of negative externalities is urgently needed. Therefore, the authors of this article describe the heterogeneity of results from previous studies on climate effects and – focusing on the agricultural sector – identify reasons for this phenomenon. The authors conduct a meta-regression analysis, based on 53 primary studies that cover the period between 1951 and 2015. All countries or country groups are included in the 1345 reported results on emitted amounts of CO2e and SO2e. Our findings confirm the well-known result that an increase in livestock quantities corresponds with a significant increase in emission levels. By integrating culture-related country data, the authors conclude that the level of “humane orientation” and the amounts of emissions follow opposite courses. Furthermore, studies conducted while the first author of this study was working for an NGO, report significantly higher emissions. Based on an adaptation of a meta-regression analysis to the field of environmental performance measurement, we are able to provide new insights about the influence of the change of individual drivers on the emission level. Examples of these insights include a one-third increase in cattle stock is associated with an increase in emissions of 29.45 t/km2. We also find that publications where the first author works for an NGO reported an emission level 87.04 t/km2 higher than other publications. These findings enable the identification of the main drivers of emissions, while helping to explain the heterogeneity of existing studies. Based on the findings of this study, companies can take reliable measures to reduce the external climate effects of their products.

Methane emissions in triple rice cropping: patterns and a method for reduction.

The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.

Methane emissions in triple rice cropping: patterns and a method for reduction.

The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.

Methane emissions in triple rice cropping: patterns and a method for reduction

The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.

Methane emissions in triple rice cropping: patterns and a method for reduction

The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.

Methane emissions in triple rice cropping: patterns and a method for reduction.

The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.

Effect of temperature on postillumination isoprene emission in oak and poplar.

Isoprene emission from broadleaf trees is highly temperature dependent, accounts for much of the hydrocarbon emission from plants, and has a profound effect on atmospheric chemistry. We studied the temperature response of postillumination isoprene emission in oak (Quercus robur) and poplar (Populus deltoides) leaves in order to understand the regulation of isoprene emission. Upon darkening a leaf, isoprene emission fell nearly to zero but then increased for several minutes before falling back to nearly zero. Time of appearance of this burst of isoprene was highly temperature dependent, occurring sooner at higher temperatures. We hypothesize that this burst represents an intermediate pool of metabolites, probably early metabolites in the methylerythritol 4-phosphate pathway, accumulated upstream of dimethylallyl diphosphate (DMADP). The amount of this early metabolite(s) averaged 2.9 times the amount of plastidic DMADP. DMADP increased with temperature up to 35°C before starting to decrease; in contrast, the isoprene synthase rate constant increased up to 40°C, the highest temperature at which it could be assessed. During a rapid temperature switch from 30°C to 40°C, isoprene emission increased transiently. It was found that an increase in isoprene synthase activity is primarily responsible for this transient increase in emission levels, while DMADP level stayed constant during the switch. One hour after switching to 40°C, the amount of DMADP fell but the rate constant for isoprene synthase remained constant, indicating that the high temperature falloff in isoprene emission results from a reduction in the supply of DMADP rather than from changes in isoprene synthase activity.

Vicia faba–Lygus rugulipennis Interactions: Induced Plant Volatiles and Sex Pheromone Enhancement

The profiles of volatile chemicals emitted by Vicia faba plants damaged by Lygus rugulipennis feeding, and by feeding plus oviposition, were shown to be quantitatively different from those released by undamaged plants. Samples of volatile chemicals collected from healthy plants, plants damaged by males as a consequence of feeding, plants damaged by females as a consequence of feeding and oviposition, plants damaged by feeding with mated males still present, and plants damaged by feeding and oviposition with gravid females still present, showed significant differences in the emission of hexyl acetate, (Z)-beta-ocimene, (E)-beta-ocimene, (E)-beta-caryophyllene, and methyl salicylate. In particular, treatments with mated females present on plants had a significant increase in emission levels of the above compounds, possibly due to eggs laid within plant tissues or active feeding, compared with undamaged plants and plants damaged by males feeding, with or without insects still present. Furthermore, the pheromonal blend released by mated L. rugulipennis females, mainly comprising hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal, was enhanced when females were active on broad bean plants, whereas such an increase was not observed in males. Both sexes gave electroantennogram responses to green leaf volatiles from undamaged plants and to methyl salicylate and (E)-beta-caryophyllene emitted by Lygus-damaged plants, suggesting that these compounds may be involved in colonization of host plants by L. rugulipennis. In addition, mated males and females were responsive to hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal released by mated females on V. faba, indicating that these substances could have a dual function as a possible aggregation pheromone in female-female communication, and as a sex pheromone in female-male communication.

Origin and mechanisms of dust emission from pulse-jet cleaned filter media

The respective contributions of direct particle penetration vs. particle reentrainment to emissions of pulse-jet cleaned filter media were measured for needle felts of different construction, in combination with two particle materials, one free-flowing and one agglomerating. Different media conditioning protocols (including accelerated aging up to 20,000 pulses) were applied as well, in order to simulate longer-term use of the filters. With about 96–99% of emissions per cycle, direct particle penetration was by far the dominant mechanism under all circumstances. The size distribution of emitted particles was centred narrowly around the MPPS between 0.5 and 1 µm, and tended to shift toward finer particles with progressive media aging, much like in a depth filter. The total reentrained dust mass per cycle was on the order of 10 − 5 of the mass stored inside the medium. Cross-sectional analysis of a few media by electron microprobe indicates that the support scrim may act as an effective barrier to particle seepage more than to direct penetration. The well known increase in emission level with cleaning pulse intensity can be attributed to a slowing-down or prevention of the clogging process, rather than enhanced reentrainment of stored dust. Earlier reports of increased emissions at higher filter face velocities are probably due to the redeposition of dust from the filter cake immediately after a cleaning pulse.