Purpose
Carbon trading mechanism has been adopted to foster the green transformation of the economy on a global scale, but its effectiveness for the power industry remains controversial. Given that ...energy-related greenhouse gas emissions account for most of all anthropogenic emissions, this paper aims to evaluate the effectiveness of this trading mechanism at the plant level to support relevant decision-making and mechanism design.
Design/methodology/approach
This paper constructs a novel spatiotemporal data set by matching satellite-based high-resolution (1 × 1 km) CO2 and PM2.5 emission data with accurate geolocation of power plants. It then applies a difference-in-differences model to analyse the impact of carbon trading mechanism on emission reduction for the power industry in China from 2007 to 2016.
Findings
Results suggest that the carbon trading mechanism induces 2.7% of CO2 emission reduction and 6.7% of PM2.5 emission reduction in power plants in pilot areas on average. However, the reduction effect is significant only in coal-fired power plants but not in gas-fired power plants. Besides, the reduction effect is significant for power plants operated with different technologies and is more pronounced for those with outdated production technology, indicating the strong potential for green development of backward power plants. The reduction effect is also more intense for power plants without affiliation relationships than those affiliated with particular manufacturers.
Originality/value
This paper identifies the causal relationship between the carbon trading mechanism and emission reduction in the power industry by providing an innovative methodology for identifying plant-level emissions based on high-resolution satellite data, which has been practically absent in previous studies. It serves as a reference for stakeholders involved in detailed policy formulation and execution, including policymakers, power plant managers and green investors.
Electrocatalytic CO2-reduction technology can convert CO2 into methanol and other chemicals using renewable electricity, but the techno-economic prospects of the large-scale electrocatalytic ...reduction in CO2 into methanol are not clear. This paper conducted sensitivity analysis to confirm the key parameters affecting the cost of methanol production from an alkaline flow cell and a neutral MEA electrolyzer, compared the cost of the two electrolyzers under laboratory data and optimized data scenarios, and analyzed the key parameter requirements of the two electrocatalytic systems to achieve profitable methanol production. The results show that electricity price, Faradaic efficiency, cell voltage, and crossover/carbonate formation ratio are the most sensitive parameters affecting the cost of methanol production. The alkaline flow cell had higher energy efficiency than the MEA cell, but the saving cost of electricity and the eletrolyzer cannot cover the cost of the regeneration of the electrolyte and CO2 lost to carbonate/bicarbonate, resulting in higher methanol production costs than the MEA cell. When the crossover/carbonate formation ratio is zero, the cost of methanol production in an alkaline flow cell and a neutral MEA cell can reach under 400 USD/tonne in the cases of energy efficiency more than 70% and 50%, respectively. Therefore, enhancing energy efficiency and ensuring a low crossover/carbonate formation ratio is important for improving the economy of electrocatalytic methanol production from CO2 reduction. Finally, suggestions on the development of electrocatalytic CO2 reduction into methanol in the future were proposed.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
To compare the dusting efficiency and safety with basketing for treating renal stones ≤ 2 cm during flexible ureteroscopy (fURS).
This study included 218 patients with renal stones ≤ 2 cm treated ...with fURS. Among them, 106 patients underwent dusting, and 112 patients underwent fragmentation with basket extraction. All patients were followed up for 3 months postoperatively. The operating time, lasing time, stone-free rate (SFR) and complication rate were compared.
The mean stone size in the dusting group was 1.3 cm, whereas 1.4 cm in the basketing group. The mean operative time was significantly lower in the dusting group than in the basketing group (43.1±11.7 minutes VS 60.5±13.4 minutes, P < 0.05), but the lasing time was significantly longer for the dusting group than for the basketing group (17.7±3.9 minutes VS 14.1±3.6 minutes, P < 0.05). SFR was significantly higher in the basketing group immediately after the operation and follow-up after 1 month (76.8% vs 55.7%, P= 0.001 and 88.4% vs 78.3%, P = 0.045). However, the SFR was similar for both groups (88.8% in the dusting group vs. 90.2% in the basketing group) after 3 months postoperatively. There was no statistical difference in the complication rates between the two groups.
Dusting has advantages in shortening the operation time and reducing the operation cost, but the lasing time was longer compared with the basketing. Although there is no difference in long-term effect, basketing is superior to dusting in terms of short-term SFR. Moreover, dusting should be avoided in some special cases and basketing a better choice. Both techniques are effective for the treatment of renal stones ≤ 2 cm and choice depends on patient demographic and stone characteristics.
Lung cancer remains the most commonly diagnosed cancer and the leading cause of death from cancer. Recent research shows that the human eye can provide useful information about one's health status, ...but few studies have revealed that the eye's features are associated with the risk of cancer. The aims of this paper are to explore the association between scleral features and lung neoplasms and develop a non-invasive artificial intelligence (AI) method for detecting lung neoplasms based on scleral images. A novel instrument was specially developed to take the reflection-free scleral images. Then, various algorithms and different strategies were applied to find the most effective deep learning algorithm. Ultimately, the detection method based on scleral images and the multi-instance learning (MIL) model was developed to predict benign or malignant lung neoplasms. From March 2017 to January 2019, 3923 subjects were recruited for the experiment. Using the pathological diagnosis of bronchoscopy as the gold standard, 95 participants were enrolled to take scleral image screens, and 950 scleral images were fed to AI analysis. Our non-invasive AI method had an AUC of 0.897 ± 0.041(95% CI), a sensitivity of 0.836 ± 0.048 (95% CI), and a specificity of 0.828 ± 0.095 (95% CI) for distinguishing between benign and malignant lung nodules. This study suggested that scleral features such as blood vessels may be associated with lung cancer, and the non-invasive AI method based on scleral images can assist in lung neoplasm detection. This technique may hold promise for evaluating the risk of lung cancer in an asymptomatic population in areas with a shortage of medical resources and as a cost-effective adjunctive tool for LDCT screening at hospitals.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A rhodium-catalyzed asymmetric 1,4-addition of α/β-(N-indolyl) acrylates to access highly enantioenriched chiral N-alkylindoles promoted by chiral diene or sulfur-olefin ligands under mild reaction ...conditions has been developed, which provides an efficient and practical approach for constructing carbon stereocenters adjacent to the indole nitrogen. The reaction can be applied to various N-indolyl-substituted α,β-unstaturated esters and arylboron reagents, providing access to a wide range of α- and β-(N-indolyl) propionate derivatives in high yields with excellent enantioselectivities (≤99% ee).
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IJS, KILJ, NUK, PNG, UL, UM
In this article, a 2-bit wideband electronically controlled reconfigurable phased array with wide-angle beam-scanning capacity is proposed. Based on the current reversal mechanism and real-time delay ...design, a wideband 2-bit phase shifter is designed by cascading a wideband 180° phase shifter and a wideband 90° phase shifter. Then, a wideband 2-bit element is established by connecting the radiation area of the Vivaldi structure at the slot line of the phase shifter, and a metasurface slab with H-shaped metal layer is introduced to improve the scanning performance. Further, a planar wideband reconfigurable 2-bit array at 17 GHz has been designed and fabricated based on this element, and a stripline-based 1:16 power divider with the phase-shifting function is designed to simulate the space-fed spherical wave to avoid high sidelobe. Measured and simulated results are in good agreement. The measured results indicate that the main beam of the array can scan from <inline-formula> <tex-math notation="LaTeX">-{\mathrm {73}}^{\circ } </tex-math></inline-formula> to 73° at 17 GHz by appropriately controlling the state of PIN diodes, and the gain fluctuation is only 2.18 dB. The measured 3 dB gain bandwidth of the array in the broadside direction is about 29.1% (from 14.7 to 19.7 GHz). The wide-angle scanning and wideband performances are verified.
The fate and emission behavior of heavy metals (As, Cd, Co, Cr, Cu, Ni, Pb, Se, and Zn) from a hazardous chemical waste incinerator were systematically explored. The results show that the main ...components of incineration fly ashes and slags contain minerals such as salt, plagioclase, pyroxene, gypsum, calcite, and slaked lime. The elements As, Cd, Pb, and Se are enriched in the fly ash particles during flue gas condensation. Co and Ni are more likely to be deposited in the rotary kiln slag and cooling tower slag owing to their lower volatility. Zn, Cr, and Cu are usually volatilized into the flue gas as oxides or chlorides are condensed and enriched in the slag of the cooling tower during the flue gas cooling process. The content of As, Cd, Pb, Ni, Cr, and Se increase with decreasing fly ash particle size. After the flue gas purification equipment was employed, the concentration of particulate metals significantly reduced. In the exhaust flue gas, the concentrations of Cu and Zn are 29.85 and 28.47 μg/m3, those of As, Cr, Ni, Pb, and Se range from 2.54 to 9.25 μg/m3, and those of Co and Cd are 0.42 and 0.13 μg/m3, respectively.
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•Heavy metals fate in hazardous waste incineration were revealed by EPA method.•Most heavy metals content increased with decreasing fly ash particle size.•The content of most heavy metals in PM1 is higher after bag filter.•Flue gas purification equipment has excellent efficiency in removing heavy metals.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
A novel dual-broadband circularly polarized (CP) reconfigurable antenna and its 2 × 2 array are presented in this letter. The proposed antenna is realized based on the double asymmetrical U-slots ...patch, and the dual-band sequential rotation technique is utilized to achieve a dual-broadband 2 × 2 arrays. The dual-band CP (DBCP) radiation characteristic of the patch is discussed based on the mode behaviors predicted by characteristic mode analysis. The switchable DBCP is achieved by asymmetrically controlling the diodes installed on the arms of two U-slots. To further improve the axial ratio (AR) performance, a 2 × 2 array with reconfigurable dual-band feeding networks is designed based on the sequential rotation technique. The measured results show that the array has wide 3 dB AR bandwidths of 28.4% and 16.0%, with wide 3 dB gain bandwidths of 23.8% and 18.2%, respectively.
A pattern reconfigurable antenna with vertical polarization is proposed based on two folded near-coupled slot antennas. To achieve two endfire beams and a bidirectional beam, respectively, a central ...feeding structure and a reconfigurable feeding strip are designed based on the current reverse principle with the help of p-i-n diodes. A prototype has been fabricated and measured to validate this design. Three high-quality radiation beams have been obtained. In the two endfire states, the measured peak gain can reach 7.15 dBi and the front-to-back ( F/B ) ratio is more than 22 dB at 5.7 GHz. In the bidirectional state, the measured peak gain can reach 3.94 dBi and the F/B ratio is less than 0.3 dB.
A pattern reconfigurable antenna with vertical polarization is proposed based on two folded near-coupled slot antennas. To achieve two end-fire beams and a bidirectional beam respectively, a central ...feeding structure and a reconfigurable feeding strip are designed based on the current reverse principle with the help of PIN diodes. A prototype has been fabricated and measured to validate this design. Three high-quality radiation beams have been obtained. In the two end-fire states, the measured peak gain can reach 7.15 dBi and the front-to-back (F/B) ratio is more than 22 dB at 5.7 GHz. In the bidirectional state, the measured peak gain can reach 3.94 dBi and the F/B ratio is less than 0.3 dB.
