Distance estimation using a monocular camera is one of the most classic tasks for computer vision. Current monocular distance estimating methods need a lot of data collection or they produce ...imprecise results. In this paper, we propose a network for both object detection and distance estimation. A network-based on ShuffleNet and YOLO is used to detect an object, and a self-supervised learning network is used to estimate distance. We calibrated the camera, and the calibrated parameters were integrated into the overall network. We also analyzed the parameter variation of the camera pose. Further, a multi-scale resolution is applied to improve estimation accuracy by enriching the expression ability of depth information. We validated the results of object detection and distance estimation on the KITTI dataset and demonstrated that our approach is efficient and accurate. Finally, we construct a dataset and conduct similar experiments to verify the generality of the network in other scenarios. The results show that our proposed methods outperform alternative approaches on object-specific distance estimation.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This paper studies majoritarian reputational bargaining. Three agents bargain over the division of one dollar under majority rule, and proposers are randomly chosen. Each agent has private ...information about whether she is a rational type that maximizes her expected share of the dollar or an obstinate type that commits to claiming a certain share of the dollar. Efficiency and surplus distribution in majoritarian reputational bargaining may differ from their counterparts in bilateral reputational bargaining. In a particular equilibrium of our majoritarian game, efficiency loss vanishes asymptotically as the agents become patient, and bargaining ends immediately if all agents are rational. Moreover, the agent who has the lowest positive ex ante probability of being obstinate achieves the highest ex ante payoff, when such probabilities for all agents are sufficiently low.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Both filterable and condensable PM2.5 from two waste incineration power plants were characterized.•Fe is the most abundant component of elements in filterable PM2.5, followed by Na, Ca, and ...Al.•Inorganic species are dominant in condensable PM2.5, accounting for 77–94%.
Compositions of filterable PM2.5 (FPM2.5) and condensable PM2.5 (CPM2.5) emitted from waste incineration power plant. Display omitted
Incineration technology is an effective treatment method for municipal solid waste (MSW). In this study, fine particulate matter emissions from two waste incineration power plants (WIPP) were characterized. Both filterable particulate matter (FPM2.5) and condensable particulate matter (CPM2.5) were collected using a direct sampling method. The FPM2.5 concentrations from stacks #1 and #2 in WIPP A were 0.87 ± 0.10 and 0.68 ± 0.19 mg/m3, respectively, and 3.30 ± 0.65 mg/m3 was measured at stack #3 in WIPP B. Fe was the most abundant elemental component in the FPM2.5, followed by Na, Ca, Al, and K. Ca2+, SO42−, Cl−, and NH4+ accounted for the largest fraction of the total detected water-soluble ions in the FPM2.5. In the CPM2.5, Na was the most abundant elemental component, followed by Ca, Mg, and K. The total detected water-soluble ions accounted for 22.2% and 27.3% of the CPM2.5 collected from stack #1 and #2, respectively. High concentrations of NH4+ and NO3− were found in CPM2.5, which could be derived from the escape of excessive NH3 in the denitrification unit and that of the NOx in the flue gas, respectively. Alcohols, aromatic compounds, and ketones were the major organic species in the CPM2.5. Both fly ash and bottom ash were collected from WIPP A. Ca was the dominant element, followed by K, Mg, Na, and Fe. The enrichment of elements in the fly ash and bottom ash were analyzed. The enrichment factors of most elements were higher than 1, except for the Ti and Sn in the bottom ash. The fly ash had a higher enrichment of Cd, As, and Ti than the bottom ash. In contrast, Cu, Ni, and Cr had higher enrichments in the bottom ash because of their low volatility.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Nitrogen oxides (NOx) emission abatement of coal-fired power plants (CFPPs) requires large-scaled installation of selective catalytic reduction (SCR), which would reduce secondary fine particulate ...matter (PM2.5) (by reducing nitrate aerosol) in the atmosphere. However, our field measurement of two CFPPs equipped with SCR indicates a significant increase of SO42− and NH4+ emission in primary PM2.5, due to catalytic enhancement of SO2 oxidation to SO3 and introducing of NH3 as reducing agent. The subsequent formation of (NH4)2SO4 or NH4HSO4 aerosol is commonly concentrated in sub-micrometer particulate matter (PM1) with a bimodal pattern. The measurement at the inlet of stack also showed doubled primary PM2.5 emission by SCR operation. This effect should therefore be considered when updating emission inventory of CFPPs. By rough estimation, the enhanced primary PM2.5 emission from CFPPs by SCR operation would offset 12% of the ambient PM2.5 concentration reduction in cities as the benefit of national NOx emission abatement, which should draw attention of policy-makers for air pollution control.
By rough estimation, the enhanced primary PM2.5 emission from coal-fired power plants due to SCR installation would offset 12% of the ambient PM2.5 concentration reduction in cities as the benefit of national NOx emission abatement. Display omitted
•SCR increases primary PM2.5 emission from coal-fired power plants.•Ammonium sulfate aerosol formed in SCR shows a bi-modal distribution of mass concentration.•Large-scaled installation of SCR may offset significantly the benefit of national NOx emission abatement in China.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The dry impinger method, the indirect dilution method, and the direct dilution method can be used to measure the condensable particulate matter (CPM) emissions. We tested these methods in determining ...the CPM emissions from typical stationary sources in China and found that the CPM concentrations measured by the dry impinger method are much higher than those measured by the two dilution methods regardless of the type of stationary source. The soluble gases (e.g., SO2, HCl, and NH3) partially absorbed by the impinger solutions are the main reason for the overestimation of the CPM concentrations. This is supported by detecting more water-soluble ions (e.g., SO4 2–, Cl–, and NH4 +) from the CPM collected using the dry impinger method. The positive biases of the CPM concentration and its water-soluble ions collected by the dry impinger method are larger under the conditions with high concentrations of soluble gases such as at the flue gas desulfurization inlet in coal-fired power plants. Comparing to the direct dilution method, the indirect dilution method can better capture the rapid dilution, cooling, and condensation of condensable gas precursors in the presence of filterable particulate matter and is recommended as the appropriate method for the CPM measurement in stationary sources.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
The performance of traditional electrostatic precipitators (ESPs) is strongly affected by the flue gas temperature. Operating under much lower temperatures (e.g., ~90 °C), the low–low temperature ...electrostatic precipitators (LLT–ESPs) are considered as an effective technology to improve the particulate matter (PM) removal efficiency in coal–fired power plants (CFPPs). Wet flue gas desulfurization (WFGD) can also be affected by the decrease in the operating temperature of the ESP. This study evaluates the influence of various ESP operating temperatures on ESP performance, PM2.5 (particles with an aerodynamic diameter of ≤2.5 μm), and total dust emission characteristics at the ESP and WFGD outlets in CFPPs equipped with LLT–ESPs. PM2.5 and total dust concentrations at the ESP and WFGD outlets in CFPPs installed with LLT–ESPs are much lower than those with traditional ESPs. The PM concentrations at both the ESP and WFGD outlets show a decreasing trend with a decrease in the operating temperature. However, the concentration of total water–soluble ions (mainly SO42−, Cl−, and NH4+) in the total dust at the outlet of ESPs increases from 0.3 to 0.8 mg/m3 as the temperature decreases from > 90 °C to 80–90 °C, which is contrary to that at the WFGD outlet (decreases from 4.7 to 0.8 mg/m3). The PM2.5 and total dust concentrations increase by 10.2–80.2% and 13.7–77.0%, respectively, through the WFGD unit due to the entrainment of a gypsum slurry. A relatively lower operating temperature of LLT–ESPs in power plants is also beneficial to decrease the incremental effect of PM emissions in the process of WFGD. The recommended operating temperature for LLT–ESPs is ~90 °C, and limited improvement on PM reduction can be achieved with a further temperature decrease from 90 to 80 °C.
Display omitted
•We characterized PM emitted from coal–fired power plants equipped with LLT–ESP.•PM concentration decreases with the decrease in operating temperature of LLT–ESP.•PM concentration at LLT–ESP outlet is lower than those with traditional ESP.•The optimal operating temperature for LLT–ESP is ~90 °C.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Flue gas desulfurization (FGD) and selective catalytic reduction (SCR) technologies have been widely used to control the emissions of sulphur dioxide (SO2) and nitrogen oxides (NOX) from coal-fired ...power plants (CFPPs). Field measurements of emission characteristics of four conventional CFPPs indicated a significant increase in particulate ionic species, increasing PM2.5 emission with FGD and SCR installations. The mean concentrations of PM2.5 from all CFPPs tested were 3.79 ± 1.37 mg/m3 and 5.02 ± 1.73 mg/m3 at the FGD inlet and outlet, respectively, and the corresponding contributions of ionic species were 19.1 ± 7.7% and 38.2 ± 7.8%, respectively. The FGD was found to enhance the conversion of NH3 slip from the SCR to NH4+ in the PM2.5, together with the conversion of SO2 to SO42−, and increased the primary NH4+ and SO42− aerosol emissions by approximately 18.9 and 4.2 times, respectively. This adverse effect should be considered when updating the emission inventory of CFPPs and should draw the attention of policy-makers for future air pollution control.
The flue gas desulfurization (FGD) system could enhance conversion of NH3 slipped from selective catalytic reduction (SCR) to NH4+ in PM2.5, before the flue gas have been emitted into the atmosphere, and thereby increasing primary NH4+ aerosol emissions by approximately four times. Display omitted
•Flue gas desulfurization increases primary PM2.5 emission from coal-fired power plants.•Flue gas desulfurization increases NH4+ aerosol emission by converting unreacted NH3.•Changes of PM2.5 in flue gas system of coal-fired power plants were measured.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Lead pollution precaution caused by lead-based anode corrosion is a hot and challenging issue for zinc electrowinning. A novel functional lead-based anode (MnO2 pre-coated anode-MPA) was precisely ...fabricated and its long-term performances were studied compared with typical Pb−1%Ag anode (TPA). Results indicated that MPA posed excellent effects on synergistic inhibiting lead dissolution and reducing hazardous pollutants generation, and decreasing the lead content of zinc products by 81%. Further, the underlying mechanism of film growth and transformation in structure, composition and crystal phase, the migration and distribution of lead and anode slime during electrolytic, were clarified in-depth. Dynamic material flow analysis confirmed that MPA reduced the entire lead migration amount by over 92% compared with TPA. The compact multilayer structure of the MPA film and self-reparation effects of local structure provided better and persistent protection for the lead matrix, which greatly retarded the high-speed corrosion of lead anode. Compared with α-MnO2 in TPA, the formation and maintenance of γ-MnO2 in MPA accelerated the oxygen evolution reaction and inhibited the anode slime generation. This finding provides new insights in pollution precaution and control by designing and tuning new functional anode in hydrometallurgy process.
Display omitted
•MPA displayed significant superiority in 92% of lead corrosion inhibition and 95% of anode slime reduction than TPA.•The compact MnO2 inner layer structure of MPA retarded the lead corrosion and dissolution by forming physical barrier.•The self-reparation effects played an important role in maintaining the compact film structure during long-term service.•Phase transformation from traditional α-MnO2 to γ-MnO2 contributed the slime generation reduction.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Display omitted
•The discrepancy of the application environment demands different characteristics of adsorbents.•The demercuration barriers, stabilization of mercury-containing compounds and ...regeneration are summarized.•Structure, hydrophobic groups and modification could purposefully overcome the bottleneck of H2O and SO2.•The thermal treatment accompanied by different components has been widely adopted as an efficient approach for regeneration.
Gaseous elemental mercury (Hg0) is a hazardous global pollutant and difficult to curb. Adsorbent is now attracting great attention in capturing Hg0 because of its recovery and system flexibility. However, the discrepancy of the application environment and competitive gas demand differential treatments on the adsorbents. In this review the current situation of Hg0 removal on different kinds of adsorbents in coal combustion flue gas, smelting flue gas and natural gas are focused. Hydrophobic groups, hydrophobic materials and modification of sulfur/selenium pretreatment and metals loading could purposefully and effectively overcome the problem of H2O and SO2. Stabilization of the mercury-laden compounds, toxicity tests of mercury-containing compounds and leaching characteristics could provide a practical perspective to the safe disposal of mercury-containing waste, reducing the risk of mercury contamination. Additionally, separation, regeneration, and recovery, are explored and summarized, in which the thermal treatment accompanied by different components has been widely adopted as an efficient approach to recover the adsorption ability. Finally, a basic understanding and outlook on demercurationis put forward.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Heavy metal contamination of soil commonly accompanies problems around gold mine tailings ponds. Fully investigating the distribution characteristics of heavy metals and the survival strategies of ...dominant plants in contaminated soils is crucial for effective pollution management and remediation. This study aims to investigate the contamination characteristics, sources of heavy metals (As, Cd, Pb, Hg, Cu, Zn, Cr, and Ni) in soils around gold mine tailings ponds areas (JHH and WZ) and to clarify the form distribution of heavy metals (As, Cd, Pb, Hg) in contaminated plots as well as their accumulation and translocation in native dominant plants. The results of the study showed that the concentrations of As, Pb, Cd, Cu, and Zn in soil exceeded the national limits at parts of the sampling sites in both study areas. The Nemerow pollution index showed that both study areas reached extreme high pollution levels. Spatial analysis showed that the main areas of contamination were concentrated around metallurgical plants and tailings ponds, with Cd exhibiting the most extensive area of contamination. In the JHH, As (74%), Cd (66%), Pb (77%), Zn (47%) were mainly from tailings releases, and Cu (52%) and Hg (51%) were mainly from gold ore smelting. In the WZ, As (42%), Cd (41%), Pb (73%), Cu (47%), and Zn (41%) were mainly from tailings releases. As, Cd, Pb, and Hg were mostly present in the residue state, and the proportion of water-soluble, ion-exchangeable, and carbonate-bound forms of Cd (19.93%) was significantly higher than that of other heavy metals. Artemisia L. and Amaranthus L. are the primary dominating plants, which exhibited superior accumulation of Cd compared to As, Pb, and Hg, and Artemisia L. demonstrated a robust translocation capacity for As, Pb, and Hg. Compared to the concentrations of other forms of soil heavy metals, the heavy metal content in Artemisia L correlates significantly better with the total soil heavy metal concentration. These results offer additional systematic data support and a deeper theoretical foundation to bolster pollution-control and ecological remediation efforts in mining areas.
Display omitted
•Pb, As, Cd, Cu, Zn and Hg are the main heavy metal polluting elements in a typical gold mining area.•The primary sources of Pb, As, Cd, Cu, and Zn are tailings releases, while Hg originates mainly from gold smelting.•The concentration of unstable forms of Cd was significantly higher than that of other heavy metals in the mine areas.•Artemisia L. has a better enrichment capacity for Cd, but a better translocation capacity for As, Pb, and Hg.•Heavy metal concentration in Artemisia L. correlate better with those of stable forms in soil than unstable forms.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
