Research on Effect of EGR and SCR on NOX Emission from a Heavy Duty Diesel Engine
Issue:
Volume 6, Issue 2, April 2017
Pages:
26-30
Received:
4 January 2017
Accepted:
23 January 2017
Published:
18 March 2017
Abstract: Experimental study was conducted on NOX emissions law of a heavy diesel engine with EGR and SCR. Opening of EGR valve (OEV) was adjusted by INCA, and ammonia nitrogen ratio (ANR) was changed by controlling urea injection quantity with control unit DCU of SCR. Under low, medium and high speed and 50%, 75% and 100% load conditions, the effect of EGR (exhaust gas recirculation) and SCR (selective catalytic reduction) on diesel engine NOX emission was studied by test. The results show that when a heavy diesel engine use EGR and SCR, the conversion magnitude and conversion ratio of NO increased significantly, NOX emissions rule is similar to that of NO, and when opening of EGR valve is more than 25%, the effects of OEV increasing on NO and NOX are smaller than the effect of SCR. Only under the conditions of high emissions concentrations of NO2, EGR and SCR significantly reduce NO2 emission concentration.
Abstract: Experimental study was conducted on NOX emissions law of a heavy diesel engine with EGR and SCR. Opening of EGR valve (OEV) was adjusted by INCA, and ammonia nitrogen ratio (ANR) was changed by controlling urea injection quantity with control unit DCU of SCR. Under low, medium and high speed and 50%, 75% and 100% load conditions, the effect of EGR ...
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Analysis of Landscape Dynamics, Trend Indicators and Evolutionary Trends in the Rusizi National Park (Burundi) from 1980 to 2015 by Remote Sensing and Field Investigations
Ntiranyibagira Elysée,
Sambou Bienvenu,
Sambou Hyacinthe,
Abou Thiam,
Vieux Boukhaly Traore,
Mamadou Lamine Ndiaye
Issue:
Volume 6, Issue 2, April 2017
Pages:
31-49
Received:
28 February 2017
Accepted:
10 March 2017
Published:
24 March 2017
Abstract: Nowadays, adaptive management of protected areas is lacking objective and integrated indicators for rigorous assessment of their evolutionary trends and the effectiveness of the conservation methods on the basis of conservation objectives and landscape dynamics. The study provides a methodological approach for determining trend indices and historical evolutionary trends which describe the developments of the Rusizi Park known to be the most threatened protected area in Burundi. The study is based on the diachronic analysis of land cover using multi-date Landsat images from 1984, 1990, 2011, 2000 and 2015 and field data. The supervised classification of the images made it possible to identify 9 to 10 land cover classes with contrasting evolutions. The park's matrix, which was made of wooded savannah in 1984 with 43.78%, consists of shrub savannah and cultivated areas occupying 25.87% and 25.40% by 2015. The results showed that during the periods 1984-1990, 1990-2000, 2000-2011 and 2011-2015, the park experienced alternating positive and negative evolutions whose trend indices are Ti [(38, 6); 2D]; Ti [(65, 22); 3D]; Ti [(78, -82); 4a] and Ti [(58, -36); 3c]; the second and the third periods being the most devastating and beneficial ones for conservation. Finally, between 1984 and 2015, the park undergone a negative evolution of trend index Ti [(77, -64), 4b] characterized by “a very strong evolution (4)" with “a strong negative trend (b)" which is represented by spatial transformations affecting 77% of the park, consisting of 82% degradation and 18% increase, resulting in a negative result of 64%. During that time, the park lost 29.9% of the vegetation cover and 31.2% of water resources in favor of anthropized areas, which increased by 94.5%. The decline of the vegetation cover is dominated by savannah and forest loss dynamics. Land cover changes are mainly caused by anthropogenic pressures and the variability of climatic conditions. They are due to six spatial processes which are dominated by patch creation and patch attrition. The results also revealed a high degree of coherence between spatial processes, class dominance and trend indicators. In general, class dominance decreases are linked to patch degradation processes and vice versa. Patch degradation processes such as fragmentation lead to negative evolutions if they affect vegetation and positive developments when they affect anthropized zones and vice versa, for patch development processes like enlargement.
Abstract: Nowadays, adaptive management of protected areas is lacking objective and integrated indicators for rigorous assessment of their evolutionary trends and the effectiveness of the conservation methods on the basis of conservation objectives and landscape dynamics. The study provides a methodological approach for determining trend indices and historic...
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Environmental Monitoring Around an Offshore Fish Farm with Copper Alloy Mesh Pens in the Northern Aegean Sea
Yesim Buyukates,
Barbaros Celikkol,
Murat Yigit,
Judson DeCew,
Musa Bulut
Issue:
Volume 6, Issue 2, April 2017
Pages:
50-61
Received:
10 March 2017
Accepted:
25 March 2017
Published:
10 April 2017
Abstract: In the present study, environmental monitoring was undertaken around an offshore fish farm with copper alloy mesh pens located in the Northern Aegean Sea. From the water velocity results obtained at the farm site, located in the Strait of Canakkale (formerly the Dardanelles) it was recorded that the horizontal water velocity reached 36cms-1 at select times. The average water velocity was found to be 22cms-1. Water quality measurements were made over an 11 months period between September 2011 and July 2012. Other than occasional wind drawn mixing events, the two different water masses can be clearly indicated depending on the temperature and salinity values recorded throughout the study period in the Strait of Canakkale. Inorganic nutrient concentrations such as NO-2+NO-3, NH4, PO4, TP and SiO2, changed from low to moderate through most of the sampling period. The data for TSS varied among sampling depths between 0.06 and 10.40 mgL-1, being below the typical seawater quality measurement threshold of 30 mgL-1 pronounced by Water Pollution Control Regulations. Chlorophyll-a concentration, ranged between 0.143-2.633μgL-1, 0.055-1.519 μgL-1, and 0.110-2.288 μgL-1, at the surface, 15m, and 30m, respectively. It has been observed that starting from March 2012, especially in Stations 2 and 3, the phytoplankton abundance controlled the TSS, rather than terrestrial sources.
Abstract: In the present study, environmental monitoring was undertaken around an offshore fish farm with copper alloy mesh pens located in the Northern Aegean Sea. From the water velocity results obtained at the farm site, located in the Strait of Canakkale (formerly the Dardanelles) it was recorded that the horizontal water velocity reached 36cms-1 at sele...
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