Transport Energy Research Articles

Biomimetic Nanostructured Polyimine Aerogels with Graded Porosity, Flame Resistance, Intrinsic Superhydrophobicity, and Closed-Loop Recovery.

Polymer aerogels, with their porous and lightweight features, excel in applications such as energy storage, absorption, and thermal insulation, making them a sought-after new material. However, the covalent cross-linking networks of current polymer aerogels result in unsustainable manufacturing and processing practices, persistently depleting our finite natural resources and causing significant global environmental impacts. Herein, we have constructed a high-performance dynamic covalent cross-linking aerogel network using biobased materials, with its structure and green sustainability akin to those of plants in nature. Abundant reversible cross-linking points endow the aerogel with ultrafast degradation capabilities, enabling allow for closed-loop chemical monomer recovery and reprocessing. Furthermore, utilizing the highly active reversible network, net-zero emission material reuse and reprocessing can be achieved. Additionally, the controlled dynamic aerogel network features a multilevel roughness nanostructured surface similar to lotus leaf and a biomimetic pore structure, contributing to significant anisotropy. The distinctive structure and composition endow the dynamic aerogel with high compressive strength (2.2 MPa) vertically, low thermal conductivity (0.0257 W/(m·K)) horizontally, and outstanding fire resistance (LOI is as high as 36%). Notably, the aerogel demonstrates the highest hydrophobicity among polyimine materials, with a contact angle of 154°. Furthermore, those dynamic aerogels have excellent performance in a variety of potential applications such as oil-water separation, directional transport, and phase change energy storage, and it is anticipated that these applications will greatly benefit from systematic upgrades in recyclability and reprocessing.

Non-linear saturation and energy transport in global simulations of magneto-thermal turbulence in the stratified intracluster medium

The magneto-thermal instability (MTI) is one of many possible drivers of stratified turbulence in the intracluster medium (ICM) outskirts of galaxy clusters, where the background temperature gradient is most likely aligned with the gravity. This instability occurs because of the fast anisotropic conduction of heat along magnetic field lines. However, the extent to which it impacts the ICM dynamics, energetics, and overall equilibrium is still a matter of debate. This work aims to understand MTI turbulence in an astrophysically stratified ICM atmosphere, its underlying saturation mechanism, and its ability to carry energy and to provide non-thermal pressure support. We performed a series of 2D and 3D numerical simulations of the MTI in global spherical models of a stratified ICM thanks to the finite-volume Godunov-type code IDEFIX and using Braginskii magnetohydrodynamics. We used well-controlled volume-averaged, shell-averaged, and spectral diagnostics to study the saturation mechanism of the MTI and its radial transport energy budget. The MTI is found to saturate through a dominant balance between injection and dissipation of available potential energy, which amounts to marginalising the Braginskii heat flux but not the background temperature gradient itself. Accordingly, the strength and injection length of MTI-driven turbulence exhibit clear dependencies on the thermal diffusivity. With realistic Spitzer conductivity, the MTI drives cluster-size motions with Mach numbers up to $ M 0.3$, even in the presence of strong stable entropy stratification. We show that such mildly compressible flows can provide about $ 15<!PCT!>$ of the non-thermal pressure support in the outermost ICM regions close to the cluster accretion shock and that the convective transport itself is much less efficient (a few percent only) than conduction at radially transporting energy. Finally, we show that the MTI saturation can be described by a diffusive mixing-length theory, shedding light on the diffusive buoyant nature, rather than the adiabatic convective nature, of the instability. The MTI seems relevant to both the dynamics and energetics of the ICM through radially biased magnetic fields that enhance the background Braginskii heat flux. Further work including externally forced turbulence, for instance, mimicking accretion-induced turbulence, is needed to assess its overall relative importance in comparison to other drivers of ICM turbulence.

GLOBAL WARMING: A COMPREHENSIVE ANALYSIS OF CAUSES, IMPACTS, AND SOLUTIONS

Global warming is one of the most critical environmental challenges facing humanity today, characterized by a significant increase in Earth's average surface temperature due to human-induced greenhouse gas emissions. This paper provides a comprehensive examination of the primary anthropogenic causes of global warming, including industrialization, deforestation, and changes in land use patterns. The burning of fossil fuels—such as coal, oil, and natural gas—for energy production and transportation has led to a dramatic rise in carbon dioxide levels in the atmosphere. This surge in CO2 concentrations has intensified the greenhouse effect, trapping more heat within the Earth's atmosphere and contributing to the overall rise in global temperatures. In addition to carbon dioxide, other potent greenhouse gases like methane and nitrous oxide, released from agricultural practices and industrial processes, exacerbate the warming effect. The expansion of industrial agriculture has significantly increased methane emissions, while synthetic fertilizers contribute to higher levels of nitrous oxide. Deforestation driven by agricultural expansion and urban development further diminishes the Earth's capacity to absorb carbon dioxide, releasing stored carbon and altering local climate patterns. The impacts of global warming are extensive, affecting ecosystems, weather patterns, and human societies worldwide. Rising sea levels threaten coastal communities, while changing precipitation patterns lead to more frequent and severe droughts and floods. This paper also discusses the interconnected nature of these factors and their complex feedback systems that amplify global warming effects. To address this multifaceted challenge, the paper proposes a comprehensive approach that includes transitioning to renewable energy sources, enhancing energy efficiency across all sectors, implementing sustainable land use practices, and fostering international cooperation through policy initiatives such as the Paris Agreement. Understanding these intricate relationships is crucial for developing effective strategies to mitigate and adapt to the challenges posed by global warming, ensuring a sustainable future for generations to come.

Elastic wave transport in angularly selective valley topological metamaterials plate

The valley degree of freedom has attracted increasing attention in elastic wave systems owing to its energy extrema at valleys and great potential in energy transportation. This study investigated the transport of valley edge states by angularly selective excitation in elastic wave metamaterials plate and designed a bifunctional elastic wave device in the bent waveguide containing two different interfaces. The supercell analysis revealed that the valley edge states exhibit symmetrical and anti-symmetrical distributions at two different interfaces. The straight and bent waveguides containing a single interface are designed, and the selective transport of valley edge states is observed due to the symmetrical or anti-symmetrical distributions at the interfaces. The angularly selective excitation of valley edge states by external excitation is demonstrated at the straight and bent interfaces. Based on these transport characteristics of valley edge states and the valley conservation mechanism, a bifunctional elastic wave device composed of a bent waveguide containing both two interfaces is designed. It can realize both the functions of the diode and the backward diode. The designed elastic wave device has the advantages of being a single structure with bifunctions. This study of topological valley transport with angularly selective characteristic may also have practical applications such as energy harvesting and sensing.

Comediation of voltage gating and ion charge in MXene membrane for controllable and selective monovalent cation separation.

Artificial ion channels with controllable mono/monovalent cation separation fulfill important roles in biomedicine, ion separation, and energy conversion. However, it remains a daunting challenge to develop an artificial ion channel similar to biological ion channels due to ion-ion competitive transport and lack of ion-gating ability of channels. Here, we report a conductive MXene membrane with polydopamine-confined angstrom-scale channels and propose a voltage gating and ion charge comediation strategy to concurrently achieve gated and selective mono/monovalent cation separation. The membrane shows a highly switchable "on-off" ratio of ∼9.9 for K+ transport and an excellent K+/Li+ selectivity of 40.9, outperforming the ion selectivity of reported membranes with electrical gating (typically 1.5 to 6). Theoretical simulations reveal that the introduced high-charge cations such as Mg2+ enable the preferential distribution of target K+ over competing Li+ at the channel entrance, and the surface potential reduces the ionic transport energy barrier for allowing K+ to pass quickly through the channel.

Entanglement and energy transportation in the central-spin quantum battery

Entanglement and energy transportation in the central-spin quantum battery

An analysis of the decomposition and driving force of carbon emissions in transport sector in China

China’s transport carbon emissions are increasing quickly and the issue of emission reduction is urgent. This article aims to calculate and decompose China’s transport carbon emissions during 2001–2019. It first calculates the China’s transport carbon emissions by IPCC carbon emission factor method, and then applies the Logarithmic Mean Divisia Index (LMDI) model for decomposition analysis. The conclusion indicates that: (1) Diesel, gasoline, kerosene, and fuel oil are the major energy sources used in China’s transport sector, with the combined consumption of diesel and gasoline exceeding 70%, and the annual growth rate of energy consumption reached 8.92% during 2000–2019. Among them, natural gas and liquefied petroleum gas (LPG) have the fastest growth rate, while the only one showing a downward trend is raw coal, indicating that China’s transportation energy structure is being optimized. (2) Although China’s transport carbon emissions have been increasing, the growth rate has declined since 2013. The proportion of carbon emissions from kerosene, diesel, natural gas, and LPG increased from 2000 to 2019, while that of raw coal, gasoline, and fuel oil decreased. This suggests that the use of clean energy, air transportation, and large-scale transportation is increasing, while the use of heavily polluting fuels and small-scale road transportation is decreasing. (3) Per capita GDP is the driving factor that has the most influence on the increase of China’s transport carbon emissions. Population positively influences transportation carbon emissions too, but issues such as aging, low fertility rates, and insufficient labor force may change the direction of the impact in the next 30 years. (4) The negative effect of energy intensity on transport carbon emissions is the greatest, followed by industrial structure and energy structure. The development of highways, new energy vehicles, railway electrification, multimodal transportation, third-party logistics, and logistics information technology in China has improved the energy structure, reduced energy intensity, and brought China’s transport sector into an important stage of innovation driven and pursuit of coordinated development with the environment.

Energy, environmental and economic performance of bi-facial photovoltaic noise barrier applied in city scale

Solar energy in transportation reduces fossil fuel consumption and supports carbon neutrality. Photovoltaic noise barriers (PVNB) are used globally to harness renewable energy along roads. This study's novelty lies in the detailed consideration of road orientation and the application of bifacial photovoltaic technology when assessing the potential for large-scale deployment of PVNB. Bifacial PV technology captures solar radiation from both sides, enhancing energy efficiency. A mathematical model was established and validated to predict PVNB power output at 5° azimuth intervals. Geographic information system (GIS) technology was used to quantify trunk roads, motorways, and RNB in Shenzhen, China. Accordingly, the electricity generation potentials of PVNB, as well as the economic and environmental benefits were calculated. The installed capacity and power generation of PVNB in Shenzhen are 432.29 MW and 313.37 GWh, respectively. The levelized cost of electricity is 0.4781 CNY/kWh. Compared to a 600 MW coal-fired unit, 9119.09 tce of fossil fuel can be saved, with lifecycle carbon reduction of 3.80 Tg and net carbon reduction of 3.05 Tg.

Socioeconomic, political and environmental consequences on the use of fossil energy in road transport: A case study of the truck drivers’ strike in São Paulo, Brazil

Socioeconomic, political and environmental consequences on the use of fossil energy in road transport: A case study of the truck drivers’ strike in São Paulo, Brazil

Distributed decision making for unmanned aerial vehicle inspection with limited energy constraint

The unsatisfactory energy density of the state-of-art batteries imposes constraints on the practical application of unmanned aerial vehicles (UAVs). Establishing a UAV airport network that integrates energy supply and information exchange functionalities represents an ideal solution for enabling synergistic UAV operations. However, devising efficient distribution protocols for these airports remains a challenge. By leveraging modeling and analysis of the energy density of existing UAV batteries, we can forecast the flight range and distances achievable by UAVs. Here, we propose a distribution protocol for UAV airport platforms aimed at enhancing distribution accuracy by the use of AI principles. Furthermore, considering the possibility of emergency UAV stop, we introduce an emergency stop system in conjunction with standard stopping procedures to optimize distribution efficiency and enhance UAV inspection safety. Moreover, existing UAV airports usually provide energy to UAVs without harnessing UAVs to facilitate interconnection and interoperability among different airports. This inefficiency leads to significant resource wastage in energy distribution. To address this, we introduce a shared energy network that allows different companies to operate according to energy distribution needs. This network not only supplies energy to UAVs but also employs UAVs for energy collection and transportation, facilitating energy trading, business collaboration, and data transmission among diverse organizations. By enabling ubiquitous energy trading, this study provides us an ideal strategy for the future construction of energy network with interconnection and interoperability, which can be extended to other applications calling for energy distribution.

Nanochannel geometry-depended behaviors on ion selectivity for salinity gradient energy harvesting

Nanofluidic osmotic energy, which can be directly converted into electricity, is considered a clean and sustainable energy that effectively utilizes salinity gradients. The rational construction of nanochannel is of great significance to ion transport and osmotic energy conversion, but there is currently little attention paid to naturally formed rough and irregular channels. In this study, a model that considers the effects of nanochannel cone angle and waveform surface on interface reaction coupling was established for osmotic energy conversion. The results indicate that cone angle and waveform have a significant effect on osmotic energy conversion. It is found that the reduction of cone angle and the addition of waveform will improve ion selectivity and increase energy conversion efficiency, and ion rectification effect of corrugated cylindrical channel is the most obvious. Meanwhile, enlarging waveform dimensions leads to a significant overlap of electric double layer, resulting in a growth in cation transference number and selectivity, thereby enhancing the system's energy conversion efficiency, which can reach 49.62%. At low concentration ratios, the waveform dimensions are inversely proportional to the maximum output power, whereas at high concentration ratios, increasing the waveform dimensions and applying the waveform at channel entrance can efficiently improve the maximum output power.

Life cycle assessment of coir fiber-reinforced composites for automotive applications

Past decades have seen an increasing prevalence of natural fiber-reinforced composites (NFRCs) due to growing conscientiousness around sustainability and a push towards vehicle lightweighting. The environmentally friendly and sustainable claims of NFRCs need to be validated due to their large variability and variety, particularly where material substitutions are concerned, such as in substituting glass fiber with natural fiber. The objective of this work is to determine the cumulative energy demand (CED) and greenhouse gas emissions (GHG) associated with an automotive part (of volume 0.001 m3) made from 40 wt% coir fiber-reinforced polypropylene (PP) and compared with a similar part made from 40 wt% glass fiber reinforced PP. SimaPro v. 9.0.0.49 was used for the analysis, whereas inventory data were collected from databases, such as Ecoinvent 3, Transportation Energy Databook, Greet model 2022, and published papers. The results showed that CED and GHG associated with the coir fiber-reinforced composite part were lower than the glass fiber-reinforced composite part for both cradle-to-gate (∼34-40%) and cradle-to-grave (excluding end-of-life) (∼24%) analysis.

Molecular Dynamics Analysis of Li+/Mg2+ Transport Mechanism in COF Membranes with Flexible Oxygen-Containing Side Chains

Lithium is currently used in a wide range of portable electronic devices. With the rapid growth of the electric vehicle sector, lithium has become an essential resource. In this work, the influence of different lengths and types of oxygen-containing side chain in COF membranes on the Li+/Mg2+ separation performance were explored via molecular dynamic simulations. The transport mechanism was elucidated through analysis of the interaction mechanism, density distribution map, potential of mean force (PMF), and dehydration number of ions during their passage through the membranes. Simulation results indicate that COF-4EO membrane shows high separation performance for Li+/Mg2+ mixture, the flexible side chain of EO provides a jumping site for Li+ ions, and the transport energy barrier in the membrane for Li+ ions is low, which enhances the screening effect into the pore. Moreover, Mg2+ ions are more difficult to dehydrate water from their hydration layer and then enter into the membrane. This work would give some insight for designing of COF membranes with well ion separation performance.

Air pollution reduction co-benefits associated with low-carbon transport initiatives for carbon neutrality in China by 2060

Low-carbon transport policy measures will contribute to greenhouse gas emission reductions, as well as improvements in air quality via air pollutant emission reductions. Here, we developed a regional transport energy model by integrating a transport demand model and an energy system model to explore the associated air pollutant emission reductions achieved by low-carbon transport initiatives when projecting a path towards carbon neutrality. Several scenarios were created to identify the effectiveness and feasibility of low-carbon strategies using the Avoid–Shift–Improve (A-S-I) framework including “Technology”, “Regulation”, “Information”, and “Economy” instruments. Significant reductions in air pollutant emissions alongside transport decarbonization in China could be realized by implementing policy measures to establish effective transport demand management, a modal shift in transport use, and technological improvements. In particular, the “Improve” strategy was more effective in delivering significant reductions in air pollutant emissions than were the “Avoid” and “Shift” strategies, but the policy effects of each A-S-I pillar varied greatly for different pollutants and across different regions. An air pollution reduction strategy for the transport sector should be designed in an integrated manner based on a series of different strategies and tools.

An Idiosyncratic Approach in the Indonesia-Japan Collaboration to Advance Renewable Energy and Public Transportation in Semarang

This study explores the impact of a leader's characteristics, particularly idiosyncratic personality traits. A prominent case study involves Mayor Hendrar Prihadi of Semarang, Indonesia, whose unique and powerful influence has significantly shaped the success of cooperation between Indonesia and Japan in the city. This study uses qualitative descriptive research. This paper relies on primary data sources, in the form of interviews with key informants and secondary data, in the form of documentation studies from relevant sources. The study reveals that city diplomacy, as observed in Semarang, is strongly associated with the Mayor's personality, level of sensitivity in responding to global issues, the influence of Javanese cultural and religious values, personal and organizational principles, and motives aimed at providing benefits to the city, particularly in the effort to create a zero-carbon urban environment. These findings underscore the link between a leader's characteristics and the decision-making process in the realm of city diplomacy, emphasizing the multifaceted nature of personality elements that guide policy choices.

Advancements in Machine Learning for Pipeline Integrity Management: A Comprehensive Review of Predictive and Optimization Techniques

Oil and gas pipeline networks are crucial component of energy infrastructure. However, as the integral elements of the energy transportation system are evolving towards Industry 4.0 and Smart Manufacturing, pipelines network are progressively shifting towards intelligence and digitization. The fields of asset integrity management, operation inspection, corrosion prevention, leak and intrusion detection, and flow assurance are just a few of the areas where machine learning and artificial intelligence (AI) algorithms are becoming more and more important. The predictive and optimization capabilities of these Models/ Algorithms have been leveraged by various Pipeline Network Integrity Management systems to avert pipeline failure, reduce environmental damage, and effectively allocate resources. This study reviews and gives a summary of current advancements in intelligent techniques, encompassing heuristic computations, mathematical programming, and machine learning techniques used in a pipeline network integrity management to enhance various operational and maintenance aspects. This work makes two intellectual accomplishments. Firstly, it offers a technical review of literatures, systematically synthesizing different computational intelligence and machine learning approaches previously applied, along with their methodologies, contributions, drawbacks, and comparisons. Secondly, the study recommends some nature-inspired meta-heuristic algorithms, which encompasses Evolutionary and the Swarm Intelligence Algorithms to be applied for future directions and challenges. Finally, the study underscores the potential of computational intelligence and algorithms for learning methods in predicting and optimizing the efficiency of pipeline network operation and management, emphasizing the necessity for further development of models/algorithms and application to enhance more intricate interactions between pipeline infrastructure monitoring, maintenance, and management.

Anaerobic decomposition of substandard pet food as a raw material source for producing hydrogen from methane

A potential raw material for producing hydrogen (the main carrier for the accumulation, storage and transportation of energy) is methane from biogas. An approach to producing biogas with a high methane content (69–72%) from waste commercial dry and wet food for dogs and cats under mesophilic conditions has been demonstrated. For 27–28 days under anaerobic conditions, the degree of biotransformation of waste was 60–88%. As a result of mineralization of watered organic waste, the content of ammonium nitrogen and phosphorus in the form of phosphates amounted to 676–887 mgNH4+/l and 77–160 mgPO43-/l, respectively. In anaerobically treated effluent, accumulation of sulfide ions up to 22 mg/l was observed. The solid sediment and anaerobically treated effluent (liquid fraction) obtained upon completion of the biotransformation of pet food waste are a potential organic fertilizer for agricultural needs, and methane from biogas is a raw material for producing hydrogen and pure carbon for the needs of the nanoindustry.

Numerical study of turbulent eddy self-interaction in tokamaks with low magnetic shear. Part II: Nonlinear simulations

Abstract Using local nonlinear gyrokinetic simulations and building up on linear results from a companion paper (Volčokas 2024 Submitted for publication), we demonstrate that turbulent eddies can extend along magnetic field lines for hundreds of poloidal turns in tokamaks with weak or zero magnetic shear s ^ . We observe that this parallel eddy length scales inversely with magnetic shear and at s ^ = 0 is limited by the thermal speed of electrons v th , e . We examine the consequences of these ‘ultra long’ eddies on turbulent transport, in particular, how field line topology mediates strong parallel self-interaction. Our investigation reveals that, through this process, field line topology can strongly affect transport. It can cause transitions between different turbulent instabilities and in some cases triple the logarithmic gradient needed to drive a given amount of heat flux. We also extensively study a novel ‘eddy squeezing’ effect introduced in Volčokas (2023 Nucl. Fusion 63 014003), which reduces the perpendicular size of eddies and their ability to transport energy, thus representing a novel approach to improve confinement. Finally, we investigate the triggering mechanism of Internal Transport Barriers (ITBs) using low magnetic shear simulations, shedding light on why ITBs are often easier to trigger where the safety factor has a low-order rational value.

Designing novel Bi-metallic MOFs with optimized Ni and Co ions ratios for enhanced supercapacitor performance

The goal of this work is to assess the novel supercapacitors (Btc-Im-DMF-Nix/Coy) by creating new bimetallic MOFs. The structure of novel bimetallic MOFs is based on the incorporation of varied Ni and Co ions ratios, as well as a large hetero-organic frame containing imidazole (Im), dimethyl formamide (DMF), and benzene tri carboxylic acid (BTC). Furthermore, the effect of the Nix:Coy ratio on the performance of supercapacitors was investigated for Btc-Im-DMF-Ni2/Co1 and Btc-Im-DMF-Ni1/Co2. The new materials were created to compensate for the conventional superapcitors' low energy density. The electrochemical performance of the novel materials is examined by a number of electrochemical studies, including galvanostatic charge/discharge (GSCD), cyclic voltammetry (CV), and surface analysis. The Btc-Im-DMF-Ni1/Co2 has an optimum capacitance of 1640 F g−1 at 1.0 A g−1, in contrast to Btc-Im-DMF-Ni2/Co1, which shows a capacitance of 1234 F g−1 at 1.0 A g−1. After 5000 cycles, Btc-Im-DMF-Ni1/Co2 has a greater cycling stability (91 %) than Btc-Im-DMF-Ni2/Co1 (85.3 %). The Co to Ni ratio of the Btc-Im-DMF-Nix/Coy has a significant impact on the electrochemical activity of the supercapacitor. Within the MOFs network, Co and Ni have shown improved capacity and cycle stability due to their easier electron transport and lower deprotonation energy.

Locational marginal pricing of energy in pipeline transport of natural gas and hydrogen with carbon offset incentives

We propose an optimization formulation for locational pricing of energy transported through a pipeline network that carries mixtures of natural gas and hydrogen from distributed sources to consumers. The objective includes the economic value provided by the pipeline to consumers of energy and suppliers of natural gas and green hydrogen, as well as incentives to lower carbon emissions by consuming the latter instead of the former. The optimization is subject to the physics of gas flow and mixing in the pipeline network as well as engineering limits. In addition to formulating this mathematical program, we synthesize the Lagrangian and derive analytical expressions for the dual variables. We propose that the dual solution can be used to derive locational marginal prices of natural gas, hydrogen, and energy, as well as the decarbonization premium paid by consumers that receive hydrogen. We derive several properties of solutions obtained using the proposed market mechanism, and demonstrate them using case studies for standard 8-node and 40-node pipeline test networks. Finally, we show that optimization-based analysis of the type proposed here is critical for making sound decisions about economic policy and infrastructure expansion for blending green hydrogen into existing natural gas pipelines.