The impacts of the COVID-19 pandemic on multimodal human mobility in London:A perspective of decarbonizing transport

Decarbonizing transport is one of the core tasks for achieving Net Zero targets,but the COVID-19 pandemic disrupts human mobility and the established transport development strategies.Although existing research has explored the relationship between virus transmission,human mobility,and restrictions policies,few have studied the responses of multimodal human mobility to the pandemic and their impacts on the achievement of decarbonizing transport.This paper employs 32 consecutive biweekly observations of mobile phone application data to understand the influences of the pandemics on multimodal human mobility from February 2020 to April 2021 in London.We here illustrate that multimodal travel behavior and traffic flows significant changed after the pandemic and related lockdowns,but the decline or recovery varies across different travel modes and lockdowns.The car mode has shown the most resilience throughout the pandemic,but the travel modes in the public transit sector were hit hard.Cycle and walk modes remained high at the beginning of the pandemic,but the trend did not continue as the pandemic developed and the season changed.Our findings suggest that the COVID-19 pandemic brought more challenges to travel mode shifting and the achievement of decarbonizing transport rather than opportunities.This analysis will assist transport authorities to optimize the established transport policies and to redistribute limited resources for accelerating the achievement of decarbonizing transport.

Electricity as an Energy Vector: A Performance Comparison with Hydrogen and Biodiesel in Italy

This study presents a comparative analysis of electricity, hydrogen, and biodiesel as energy vectors, with a focus on powering an aluminum smelter in southern Italy. It evaluates these vectors in terms of efficiency, land requirements for carbon-neutral energy production, and capital expenditure, providing insights throughout the entire supply chain (upstream, midstream, and downstream) into their feasibility for industrial applications. The research reveals that biodiesel, despite being carbon neutral, is impractical due to extensive land requirements and lower efficiency if compared to other vectors. Hydrogen, downstream explored in two forms as thermal power generation and fuel cell technology, shows lower efficiency and higher capital expenditure compared to electricity. Additionally, green hydrogen production’s land requirements significantly exceed those of electricity-based systems. Electricity emerges as the most viable option, offering an overall higher efficiency, lower land requirements for its green production, and comparatively lower capital expenditure. The study’s findings highlight the importance of a holistic assessment of energy vectors, considering economic, environmental, and practical aspects along the entire energy supply chain, especially in industrial applications where the balance of these factors is crucial for long-term sustainability and feasibility. This comprehensive analysis provides valuable guidance for similar industrial applications, emphasizing the need for a balanced approach in the selection of energy vectors.

Green Hydrogen: Perspectives and Challenges in Using the Natural Gas Network in Ceará/Brazil

Climate change, mainly caused by the use of non-renewable fuels, has raised global concerns and led to the search for less polluting energy sources, making hydrogen a promising energy alternative with the potential to contribute to changes in the energy mix of various countries through the use of technologies that enable its production and use with low or zero carbon emissions. In this context, Brazil has aroused great interest from other countries in exploring its renewable resources for the production of hydrogen (green hydrogen). In this sense, the use of natural gas pipelines and the use of hydrogen in mixtures with natural gas have become the subject of studies due to their economically viable alternative for the immediate use of this energy vector. However, there are still technical and regulatory challenges regarding the integration of hydrogen into the existing natural gas pipeline network. In this context, the present study aims to address the effects of hydrogen interaction with the structure of natural gas pipeline steel and the regulatory barriers to the use of this network for the transportation of green hydrogen, particularly in the state of Ceará/Brazil. After extensive analysis of literature and regulatory documents, it was concluded that: 1) Ceará/Brazil has strong potential to meet the demand for green hydrogen through the use of solar and wind energy sources;2) there is feasibility for the adaptation or conversion of natural gas infrastructure for the transportation of green hydrogen;3) discussions regarding the regulatory competence of green hydrogen transportation and distribution through the natural gas network in Brazil are still incipient;4) the current regulation of the natural gas industry can serve as a subsidy for the regulation of green hydrogen and natural gas transportation.

Decarbonization and Decolorization of Large Sapphire Crystals Grown by the Temperature Gradient Technique

A crystalline sapphire （Al2O3） boule （Ф10 × 80mm^3） grown by the temperature gradient technique （TGT） is a bit colored due to carbon volatilization from the graphite heater at high temperatures and the absorption of transitional metal inclusions in the raw material. The sapphire becomes colorless and transparent after decolorization and decarbonization in successive annealings in air and hydrogen at high temperatures. The quality, optical transmissivity,and homogeneity of the sapphire are remarkably improved.

A STUDY OF THE PROPERTIES OF S25C-SUS405 STEEL JOINTS BY VAOUUM DIFFUSION WELDING

In this paper, the properties of S25C-SUS405 steel joints by vacuum diffusion welding are discussed, and the specific deformation, tensile strength and hardness of the joints made of those two kinds of steel are introduced. Through metallographic examination and microanalysis, it can be observed that at the weld interface of the joints there is a decarbonized layer on the S25C steel side and a carburized layer on the SUS405 steel side. This is the main cause giving rise to the heterogeneity of microstructure distribution and the nonuniformity of hardness distribution in weldment. In addition, with the help of electronic probe microanalysis the element distribution, such as carbon and chrome, is reported in this paper.

Effects of key factors of rotary triboelectrostatic separator on efficiency of fly ash decarbonization

On the basis of understanding the principle of rotary triboelectrostatic separation, dynamic analysis of charged fly ash particles aimed at determining the key factors and separation experiments to improve decarbonization efficiency had been carried out Variables of electrode plate voltage and corrected wind speed are the key factors which affect the decarbonization efficiency on the separation of fly ash, The results of separation experiments show that:(1) With the plate voltage increasing, the efficiency of decarbonization continuously rises and in its selected range, the optimal voltage level is 45 KV;(2) The corrected wind speed can impact the efficiency of decarbonization significantly: with the speed increasing, the efficiency of decarbonization shows a trend of first decline, then increase and decrease again, and in its selected range, the optimal speed is 2.0 m/s. This study is of significance for the improvement of rotary triboelectrostatic separation performance and its decarbonization separation efficiency.

Electrical properties of fly ash and its decarbonization by electrostatic separation

The basic principle of fly ash triboelectrification is analysed. The mineral electrical index and test method are introduced. The electric difference of different mineral composition of fly ash is discussed by analysis of chemical and mineral composition of fly ash in Xinwen power plant. The dielectric constant and charge-mass ratio of carbon and ash of fly ash are tested. Combined with the experimental study on rotary triboelectrostatic separation, the charged characteristic of fly ash particles with different size is gained. The results show that the dielectric constant of fly ash with different grain size decreased with the decrease of particle size, which lead to the poor electrical conductivity, Thus it can be seen that par- ticle size plays a leading role in conductivity, The charge of carbon and ash with each size increased with the decreased of particle size; and the charge-mass ratio between carbon and ash with the same size lar- ger with the decrease of size, which indicated that the finer particle size, the more favorable for triboelec- trification separation. In the same conditions, the best decarburization effect is realized when the particle size ranges from 0.038 to 0.074 ram, whose decarbonization rate and efficiency index reached 38.93% and 120.83% respectively.

Frontiers of CO_(2)Capture and Utilization(CCU)towards Carbon Neutrality

CO_(2)capture,utilization,and storage(CCUS)technology is a rare option for the large-scale use of fossil fuels in a low-carbon way,which will definitely play a part in the journey towards carbon neutrality.Within the CCUS nexus,CCU is especially interesting because these processes will establish a new“atmosphere-to-atmosphere”carbon cycle and thus indirectly offer huge potential in carbon reduction.This study focuses on the new positioning of CCUS in the carbon neutrality scenario and aims to identify potential cutting-edge/disruptive CCU technologies that may find important application opportunities during the decarbonization of the energy and industrial system.To this end,direct air capture(DAC),flexible metal-framework materials(MOFs)for CO_(2)capture,integrated CO_(2)capture and conversion(ICCC),and electrocatalytic CO_(2)reduction(ECR)were selected,and their general introduction,the importance to carbon neutrality,and most up-to-date research progress are summarized.

Decarbonization options of the iron and steelmaking industry based on a three-dimensional analysis

Decarbonization is a critical issue for peaking CO_(2) emissions of energy-intensive industries,such as the iron and steel industry.The decarbonization options of China’s ironmaking and steelmaking sector were discussed based on a systematic three-dimensional low-carbon analysis from the aspects of resource utilization(Y),energy utilization(Q),and energy cleanliness which is evaluated by a process general emission factor(PGEF)on all the related processes,including the current blast furnace(BF)-basic oxygen furnace(BOF)integrated process and the specific sub-processes,as well as the electric arc furnace(EAF)process,typical direct reduction(DR)process,and smelting reduction(SR)process.The study indicates that the three-dimensional aspects,particularly the energy structure,should be comprehensively considered to quantitatively evaluate the decarbonization road map based on novel technologies or processes.Promoting scrap utilization(improvement of Y)and the substitution of carbon-based energy(improvement of PGEF)in particular is critical.In terms of process scale,promoting the development of the scrap-based EAF or DR-EAF process is highly encouraged because of their lower PGEF.The three-dimensional method is expected to extend to other processes or industries,such as the cement production and thermal electricity generation industries.

Review of trans-Mediterranean power grid interconnection:a regional roadmap towards energy sector decarbonization

Climate change is becoming an important issue in all fields of infrastructure development.Electricity plays a core role in the decarbonized energy system’s path to a regional zero-emission pattern.A well-built trans-Mediterranean backbone grid can hedge the profound evolution of regional power generation,transmission,and consumption.To date,only Turkey and the Maghreb countries(i.e.,Morocco,Algeria,and Tunisia)are connected with the Continental European Synchronous Area.Other south-and east-shore countries have insufficient interconnection infrastructures and synchronization difficulties that have proven to be major hurdles to the implementation of large-scale solar and wind projects and achievement of climate goals.This study analyzes the current trans-boundary grid interconnections and power and carbon emission portfolios in the Mediterranean region.To align with the recently launched new climate target‘Fit for 55’program and the accelerated large-scale renewables target,a holistic review of projected trans-Mediterranean grids and their market,technical,and financial obstacles of implementation was conducted.For south-and east-shore countries,major legal and regulatory barriers encompassing non-liberalized market structure,regulation gaps of taxation and transmission tariffs,and the private sector’s access rights need to be removed.Enhancement of domestic grids,substations,and harmonized grid codes and frequency,voltage,and communication technology standards among all trans-Mediterranean countries are physical prerequisites for implementing the Trans-Mediterranean Electricity Market.In addition,the mobilization of capital instruments along with private and international investments is indispensable for the realization of supranational transmission projects.As the final section of the decarbonization roadmap,the development of electric appliances,equipment,and vehicles with higher efficiency is inevitable in the decarbonized building,transportation,and industry sectors.

What decarbonized the residential building operation worldwide since the 2000s

Decarbonization in operational residential buildings worldwide has become critical in achieving the carbon neutral target due to the growing household energy demand.To accelerate the pace of global carbon neutrality,this study explores the operational carbon change in global residential buildings through the generalized Divisia index method and decoupling analysis,considering the decarbonization levels of residential buildings at different scales.The results show that(1)most of the samples showed a decrease in the total emissions from 2000 to 2019.Except for China and the United States(US),the carbon emissions in global residential building operations decreased by 7.95 million tons of carbon dioxide(MtCO_(2))per year over the study period.Emissions per gross domestic product(GDP)was the most positive driver causing the decarbonization of residential buildings,while GDP was the most negative driver.(2)Carbon intensity was essential to achieving a strong decoupling of economic development and carbon emissions.The US almost consistently presented strong decoupling,while China showed weak decoupling over the last two decades.(3)The pace of decarbonization in global residential building operations is gradually slowing down.From 2000 to 2019,decarbonization from residential buildings across 30 countries was 2094.3 MtCO_(2),with a decarbonization efficiency of 3.4%.Overall,this study addresses gaps in evaluating global decarbonization from operational residential buildings and provides a reference for evaluating building decarbonization by other emitters.

国际海事组织船舶能效提案及其影响综述

This paper presents a review of the different International Maritime Organization(IMO)initiatives to improve the ship energy efficiency of new and existing ships,which is considered one of the essential tasks to reduce Greenhouse Gas(GHG)in the maritime industry.First,the IMO effort and initiatives and the different indices suggested by the IMO are presented till the last version of the Marine Environment Protection Committee(MEPC),showing the effect of different technologies on reducing the level of indices and the suggested improvement of the terms of indices in the next years.Second,the short-and long-term strategies suggested by the IMO are presented,showing that the effect of indices will be noticed in the short term,while the new fuels will show a significant improvement in the long term.Finally,several examples of cooperation between the different organizations are presented,showing that transferring knowledge and experience will significantly impact the maritime industry and thus lead to the concept of green ships in the near future.This paper shows that the combination of different solutions,the cooperation between stakeholders and the sharing of the data and information are important to achieve the required goal.

Process reconfiguration and intensification:An emerging opportunity enabling efficient carbon capture and low-cost blue hydrogen production

Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources,requiring additional CO_(2)capture to decarbonize, which energy intense and costly. In a recent Green Energy & Environment paper, Cheng and Di et al. proposed a novel integration process referred to as SECLR_(HC) to generate high-purity H_(2) by in-situ separation of H_(2)and CO without using any additional separation unit. Theoretically, the proposed process can essentially achieve the separation of C and H in gaseous fuel via a reconfigured reaction process, and thus attaining high-purity hydrogen of ~99%, as well as good carbon and hydrogen utilization rates and economic feasibility. It displays an optimistic prospect that industrial decarbonization is not necessarily expensive, as long as a suitable CCS measure can be integrated into the industrial manufacturing process.

某散货船单桨、双桨推进系统燃油消耗分析

This paper presents a comparative analysis between single and twin-screw propulsion systems of a bulk carrier to evaluate the ship and propeller performance in terms of fuel consumption as well as to discuss the cavitation and noise criteria.An optimization model is developed to select the optimum propeller geometry and operational point along the engine load diagram for the selected engines of each case.The engines are selected from the same series due to the same behaviour along the engine load diagram.The propellers are selected from the B-series as fixed-pitch propellers.It has been concluded that while the components of the single-screw propulsion system are larger than the twin-screw,the single-screw propulsion system shows a reduction in fuel consumption than the twin screw by around 19%,thus affecting the amount of exhaust emissions from the ship.This model helps the ship designers to select a suitable propeller to improve the energy efficiency of the ships.

Photoelectrochemical CO_(2) electrolyzers: From photoelectrode fabrication to reactor configuration

The photoelectrochemical conversion of CO_(2) into value-added products emerges as an attractive approach to alleviate climate change. One of the main challenges in deploying this technology is, however, the development and optimization of(photo)electrodes and photoelectrolyzers. This review focuses on the fabrication processes, structure, and characterization of(photo)electrodes, covering a wide range of fabrication techniques, from rudimentary to automated fabrication processes. The work also highlights the most relevant features of(photo)electrodes, with special emphasis on how to measure and optimize them. Finally, the review analyses the integration of(photo)electrodes in different photoelectrolyzer architectures, analyzing the most recent research work that comprises photocathode, photoanode,photocathode-photoanode, and tandem photoelectrolyzer configurations to ideally achieve self-sustained CO_(2) conversion systems. Overall, comprehensive guidelines are provided for future advancements in developing effective devices for CO_(2) conversion, bridging the gap towards the use of sunlight as the unique energy input and practical applications.

海上运输的脱碳:土耳其船队的案例研究

Climate change and global warming are among the most severe threats to the global ecosystem,caused by greenhouse gas emissions.Therefore,all industries that cause environmental emissions should collaborate in the struggle against climate change.In this context,the International Maritime Organization(IMO)approved the initial greenhouse gas strategy at the MEPC 72 session in April 2018 to achieve targets for 2050.With this strategy,the IMO aims to create and improve new regulations that can enhance energy efficiency to achieve their short-term,midterm,and long-term goals.In this study,one of the novel terms,energy efficiency existing ship index(EEXI)values,has been calculated for the Turkish fleet to guide the maritime sector.The Turkish fleet in the study refers to the Turkish-owned vessels both sailing with a national or international flag.In accordance with this regulation,the number of Turkish fleets that were identified as either above or below the IMO reference lines has been determined.Additionally,EEXI values have been recalculated using the engine power limitation(EPL)method for ships that exceed the required limits,and the success rate of this method has been estimated.As a result,the application of EPL increased the number of ships below the Phase 2 reference line from 15.6%to 53.1%.To the best of our knowledge,this research,which has been carried out on all Turkish-owned ships,is the first study intended to serve as a guide for other ship owners in the global maritime industry regarding energy efficiency management.

Erosion Effect of Molten Steel on Carbon Containing Refractories for Continuous Casting

The erosion resistance of carbon containingrefractories for continuous casting to molten steel wasinvestigated by means of simulative erosion test and examining used refractories. Decarbonization and reaction between molten steel and decarbonization layer are main erosion process of carbon containingrefractories by molten steel. The reactions between molten steel and oxide in refractories determine thethickness of decarbonization layer. A dense layer formation on the working surface contacting withmolten steel during casting will suppress decarbonization and erosion process.

Right-wing and populist support for climate mitigation policies:Evidence from Poland and its carbon-intensive Silesia region

Research on environmental behaviour is often overlooked in literature on regime destabilization in energy transitions.This study addresses that gap by focusing on socio-political and demographic factors shaping support for carbon regime destabilization policies in one of the most carbon-intensive regions of Europe.Carbon-intensive industries,especially coal mining and coal-based power generation,are often concentrated in a few carbon-intensive regions.Therefore,decarbonization actions will affect those regions particularly strongly.Correspondingly,carbon-intensive regions often exert significant political influence on the two climate mitigation policies at the national level.Focusing on Poland,we investigate socio-political and demographic factors that correlate with the approval or rejection of the two climate mitigation policies:increasing taxes on fossil fuels such as oil,gas,and coal and using public money to subsidize renewable energy such as wind and solar power in Poland and its carbon-intensive Silesia region.Using logistic regression with individual-level data derived from the 2016 European Social Survey(ESS)and the 2014 Chapel Hill Expert Survey(CHES),we find partypolitical ideology to be an important predictor at the national level but much less so at the regional level.Specifically,voting for right-wing party is not a divisive factor for individual support of the two climate mitigation policies either nationally or regionally.More interestingly,populism is a strong factor in support of increasing taxes on fossil fuel in the carbon-intensive Silesia region but is less important concerning in support of using public money to subsidize renewable energy in Poland overall.These results show the heterogeneity of right-wing party and populism within the support for the two climate mitigation policies.Socio-demographic factors,especially age,gender,education level,employment status,and employment sector,have even more complex and heterogeneous components in support of the two climate mitigation policies at the national and regional levels.Identifying the complex socio-political and demographic factors of climate mitigation policies across different national versus carbon-intensive regional contexts is an essential step for generating in situ decarbonization strategies.

船体风机叶片对中速船水动力性能影响的计算分析

The importance of reducing ship resistance is growing considerably as a result of the increase in atmospheric emissions and the drive towards green shipping through decarbonization.Until this point,Energy Saving Devices(ESD),in particular,Hull Vane®(HV),have been widely applied as a potential technique for reducing wave-making resistance for vessels with higher Froude Number(Fr).The advantages of HV for a medium-speed vessel,where the wave-making component accounts for almost 50%of total resistance,have yet to be investigated.This study presents the computational analysis of the KCS model(1∶75.5);for a particular trim condition by using the VOF method and RANS solver.The hull acts as a candidate vessel for the class of medium-speed characteristics.A total of 36 numerical simulations were carried out to study the changes in resistance and motion characteristics of the vessel with and without HV.To validate the numerical setup,the experimental work of Hou et al(2020)on the DTMB hull was used.The effectiveness of HV can be comprehended by the reduction percentage in total resistance,trim,sinkage,and transom wave height,in comparison to bare hull condition.The reduction in total resistance extends up to 6%for Fr=0.32 with configuration 2 with negative AoF.The CFD results indicate that there is a reduction in trim up to 57%for the maximum speed with a corresponding Fr=0.34 with a positive angle of foil(AoF).The trim correction effect is increasing with the depth of submergence of HV.Concerning sinkage,there occurs nearly a 31%reduction for Fr=0.34 with a positive AoF.There exists a substantial reduction in the height of the transom wave with the inclusion of HV,the results of which are discussed in detail.From the presented results,retrofitting the Hull Vane®is effective in the selected speed range but pronouncing as the speed of the vessel increases.

Improvement of Service Life and Reliability of SEN for TSCC

SEN is a key relative technology to TSCC, the quality of which influences not only the heats of continuous casting but also the stream field in the mould. The powder line is the key part of SEN, that determines the continuous casting life. In this study the microstructure of used SEN samples were examined by SEM, the causes of the abnormal erosion phenomena were analyzed from slag corrosion mechanism, reactions between carbon containing refractories and slag and molten steel, properties of refractories. The improvement of the quality of SEN were achieved by adjusting the graphite content and composite structure designing of SEN＇s powder line.