Elemental mercury（Hg^0）re-emissions from slurries and solutions were evaluated in a lab-scale simulated scrubber.Oxidized mercury（Hg^2 ＋）standard solution was injected into the simulated scrubber at a desired rat...Elemental mercury（Hg^0）re-emissions from slurries and solutions were evaluated in a lab-scale simulated scrubber.Oxidized mercury（Hg^2 ＋）standard solution was injected into the simulated scrubber at a desired rate to simulate absorbing and dissolving of Hg^2 ＋in the flue gas across wet flue gas desulfurization（WFGD）systems. PS analytical mercury analyzer was used to continuously determine Hg0re-emission concentrations in the carrier gas from the scrubber.Sulfite ion in the slurry of CaSO3 was validated to reduce Hg ^2＋to Hg^ 0,while no Hg ^0 re-emission occurred from slurries of CaSO4 and CaO.Transitional metal ions with low chemical valence such as Fe^2 ＋,Pb ^2＋,Ni ^2＋, AsO2^-and Cu ^＋were used to prepare solutions with concentration levels of mmol·L^-1.Reduction reaction of Hg^2 ＋to Hg 0was observed from these solutions.Reduction capabilities for the different transitional metal ions in the solutions were：Pb^2 ＋〉Cu ^＋〉Fe^ 2＋〉 AsO2^-〉Ni ^2＋.展开更多
Vocabulary knowledge is an important component of the writing skill and it has many dimensions, such as size, depth, and productive, in interaction with writing skill. To evaluate this relation and determine which dim...Vocabulary knowledge is an important component of the writing skill and it has many dimensions, such as size, depth, and productive, in interaction with writing skill. To evaluate this relation and determine which dimension is the most effective for second language writing quality, the present study was conducted. Turkish EFL （English as a Foreign Language） learners＇ lexical competence and writing abilities were examined through their vocabulary profiles and academic essays. The results of each vocabulary measure indicated that the participants had a limited vocabulary size, containing words mostly from 2,000 to 3,000 frequency bands and thus, the productive vocabulary knowledge of the participants mostly consisted of lk ＋ 2k words and the use of academic words in their essays was very low. The results of the study revealed that the lexical competence covering the main components of vocabulary knowledge was a good predictor of the students＇ quality of writing performance.展开更多
A laboratory-scale MFC （microbial fuel cell） was studied in order to determine the capacity and the efficiency of electricity production in microbial fuel cell system by using microorganisms. The medium used is an i...A laboratory-scale MFC （microbial fuel cell） was studied in order to determine the capacity and the efficiency of electricity production in microbial fuel cell system by using microorganisms. The medium used is an isolated culture ofSaccharomces cereviciae. A number of media has been evaluated to provide the best growth phase for Saccharomces cereviciae using optical density method with spectrophotometer at a wavelength of 550 nm. Nation 117, Lyntech, USA is used as proton exchange membrane and graphites with surface area 1.46 x 10.3 m2 are used as cathodes. Cathode chamber is fulfilled with a mixture of electrolyte compounds K3Fe（CN）6 and a buffer solution. Microbes that have been cultured are applied into anode chamber. A number of factors need to be controlled so that microbes can generate electrical energy efficiently, such as by measuring the degree of acidity and DO value in the anode compartment. In this research, the usage of riboflavin as a mediator is also investigated, while the usage of riboflavin increase production efficiency 53.90% compare to MFC without riboflavin as a mediator.展开更多
基金Supported by the US Agency for International Development(USAID)cooperation agreement(486-A-00-06-000140-00)
文摘Elemental mercury（Hg^0）re-emissions from slurries and solutions were evaluated in a lab-scale simulated scrubber.Oxidized mercury（Hg^2 ＋）standard solution was injected into the simulated scrubber at a desired rate to simulate absorbing and dissolving of Hg^2 ＋in the flue gas across wet flue gas desulfurization（WFGD）systems. PS analytical mercury analyzer was used to continuously determine Hg0re-emission concentrations in the carrier gas from the scrubber.Sulfite ion in the slurry of CaSO3 was validated to reduce Hg ^2＋to Hg^ 0,while no Hg ^0 re-emission occurred from slurries of CaSO4 and CaO.Transitional metal ions with low chemical valence such as Fe^2 ＋,Pb ^2＋,Ni ^2＋, AsO2^-and Cu ^＋were used to prepare solutions with concentration levels of mmol·L^-1.Reduction reaction of Hg^2 ＋to Hg 0was observed from these solutions.Reduction capabilities for the different transitional metal ions in the solutions were：Pb^2 ＋〉Cu ^＋〉Fe^ 2＋〉 AsO2^-〉Ni ^2＋.
文摘Vocabulary knowledge is an important component of the writing skill and it has many dimensions, such as size, depth, and productive, in interaction with writing skill. To evaluate this relation and determine which dimension is the most effective for second language writing quality, the present study was conducted. Turkish EFL （English as a Foreign Language） learners＇ lexical competence and writing abilities were examined through their vocabulary profiles and academic essays. The results of each vocabulary measure indicated that the participants had a limited vocabulary size, containing words mostly from 2,000 to 3,000 frequency bands and thus, the productive vocabulary knowledge of the participants mostly consisted of lk ＋ 2k words and the use of academic words in their essays was very low. The results of the study revealed that the lexical competence covering the main components of vocabulary knowledge was a good predictor of the students＇ quality of writing performance.
文摘A laboratory-scale MFC （microbial fuel cell） was studied in order to determine the capacity and the efficiency of electricity production in microbial fuel cell system by using microorganisms. The medium used is an isolated culture ofSaccharomces cereviciae. A number of media has been evaluated to provide the best growth phase for Saccharomces cereviciae using optical density method with spectrophotometer at a wavelength of 550 nm. Nation 117, Lyntech, USA is used as proton exchange membrane and graphites with surface area 1.46 x 10.3 m2 are used as cathodes. Cathode chamber is fulfilled with a mixture of electrolyte compounds K3Fe（CN）6 and a buffer solution. Microbes that have been cultured are applied into anode chamber. A number of factors need to be controlled so that microbes can generate electrical energy efficiently, such as by measuring the degree of acidity and DO value in the anode compartment. In this research, the usage of riboflavin as a mediator is also investigated, while the usage of riboflavin increase production efficiency 53.90% compare to MFC without riboflavin as a mediator.
