Due to high price of Straight Vegetable Oil （SVO） for bio-diesel production, the use of Waste Cooking Oil （WCO） will be cost effective. Furthermore, utilization of WCO will refrain waterways pollution and endanger...Due to high price of Straight Vegetable Oil （SVO） for bio-diesel production, the use of Waste Cooking Oil （WCO） will be cost effective. Furthermore, utilization of WCO will refrain waterways pollution and endanger ecosystem. In Malaysia, more than 50-tone of WCO from various sources was produced every day. This study evaluates combustion performance and exhaust emission characteristics of several WCOs with different sources. Modification on fuel properties has been done to improve the combustion and exhaust emission of using WCO as diesel fuel. Regular diesel fuel also has been used for comparison in the test. A 0.6 liter, single-cylinder, air-cooled direct injection diesel engine was used to perform this experiment. Experiment was done at variable engine loads at constant speed.展开更多
Ecosystem carbon allocation can indicate ecosystem carbon cycling visually through its quantification within different carbon pools and carbon exchange.Using the ecological inventory and eddy covariance measurement ap...Ecosystem carbon allocation can indicate ecosystem carbon cycling visually through its quantification within different carbon pools and carbon exchange.Using the ecological inventory and eddy covariance measurement applied to both a mature temperate mixed forest in Changbai Mountain (CBM)and a mature subtropical evergreen forest in Dinghu Mountain (DHM),we partitioned the ecosystem carbon pool and carbon exchange into different components,determined the allocation and analyzed relationships within those components.Generally, the total carbon stock of CBM was slightly higher than that of DHM due to a higher carbon stock in the arbor layer at CBM.It was interesting that the proportions of carbon stock in vegetation,soil and litter were similar for the two mature forests.The ratio of vegetation carbon pool to soil carbon stock was 1.5 at CBM and 1.3 at DHM.However, more carbon was allocated to the trunk and root from the vegetation carbon pool at CBM,while more carbon was allocated to foliage and branches at DHM.Moreover,77% of soil carbon storage was limited to the surface soil layer (0-20cm),while there was still plentiful carbon stored in the deeper soil layers at DHM.The root/shoot ratios were 0.30 and 0.25 for CBM and DHM,respectively.The rates of net ecosystem productivity (NPP)to gross ecosystem productivity (GPP)were 0.76 and 0.58,and the ratios of ecosystem respiration (Re)to GPP were 0.98and 0.87for CBM and DHM,respectively.The net ecosystem carbon exchange/productivity (NEP)was 0.24t C ha^-1 yr^-1 for CBM and 3.38t C ha^-1 yr^-1 for DHM.Due to the common seasonal and inter-annual variations of ecosystem carbon exchange resulting from the influence of environmental factors,it was necessary to use the long record dataset to evaluate the ecosystem sink capacity.展开更多
文摘Due to high price of Straight Vegetable Oil （SVO） for bio-diesel production, the use of Waste Cooking Oil （WCO） will be cost effective. Furthermore, utilization of WCO will refrain waterways pollution and endanger ecosystem. In Malaysia, more than 50-tone of WCO from various sources was produced every day. This study evaluates combustion performance and exhaust emission characteristics of several WCOs with different sources. Modification on fuel properties has been done to improve the combustion and exhaust emission of using WCO as diesel fuel. Regular diesel fuel also has been used for comparison in the test. A 0.6 liter, single-cylinder, air-cooled direct injection diesel engine was used to perform this experiment. Experiment was done at variable engine loads at constant speed.
基金National Key Research and Development Program of China(2017YFC0503801,2016YFC0500202)National Natural Science Foundation of China(31570446)Science and Technology Service Network Initiative(KFJ-SW-STS-169)
文摘Ecosystem carbon allocation can indicate ecosystem carbon cycling visually through its quantification within different carbon pools and carbon exchange.Using the ecological inventory and eddy covariance measurement applied to both a mature temperate mixed forest in Changbai Mountain (CBM)and a mature subtropical evergreen forest in Dinghu Mountain (DHM),we partitioned the ecosystem carbon pool and carbon exchange into different components,determined the allocation and analyzed relationships within those components.Generally, the total carbon stock of CBM was slightly higher than that of DHM due to a higher carbon stock in the arbor layer at CBM.It was interesting that the proportions of carbon stock in vegetation,soil and litter were similar for the two mature forests.The ratio of vegetation carbon pool to soil carbon stock was 1.5 at CBM and 1.3 at DHM.However, more carbon was allocated to the trunk and root from the vegetation carbon pool at CBM,while more carbon was allocated to foliage and branches at DHM.Moreover,77% of soil carbon storage was limited to the surface soil layer (0-20cm),while there was still plentiful carbon stored in the deeper soil layers at DHM.The root/shoot ratios were 0.30 and 0.25 for CBM and DHM,respectively.The rates of net ecosystem productivity (NPP)to gross ecosystem productivity (GPP)were 0.76 and 0.58,and the ratios of ecosystem respiration (Re)to GPP were 0.98and 0.87for CBM and DHM,respectively.The net ecosystem carbon exchange/productivity (NEP)was 0.24t C ha^-1 yr^-1 for CBM and 3.38t C ha^-1 yr^-1 for DHM.Due to the common seasonal and inter-annual variations of ecosystem carbon exchange resulting from the influence of environmental factors,it was necessary to use the long record dataset to evaluate the ecosystem sink capacity.
