Hasil untuk "Fuel"

A. Jacobson

H. Gray

Jinfeng Wu, Xiao‐Zi Yuan, Jonathan Martin et al.

G. Knothe

L. Snead, T. Nozawa, Y. Katoh et al.

Viral Mehta, J. Cooper

Qingfeng Li, Ronghuan He, J. Jensen et al.

The state-of-the-art of polymer electrolyte membrane fuel cell (PEMFC) technology is based on perfluorosulfonic acid (PFSA) polymer membranes operating at a typical temperature of 80 °C. Some of the key issues and shortcomings of the PFSA-based PEMFC technology are briefly discussed. These include water management, CO poisoning, hydrogen, reformate and methanol as fuels, cooling, and heat recovery. As a means to solve these shortcomings, high-temperature polymer electrolyte membranes for operation above 100 °C are under active development. This treatise is devoted to a review of the area encompassing modified PFSA membranes, alternative sulfonated polymer and their composite membranes, and acid−base complex membranes. PFSA membranes have been modified by swelling with nonvolatile solvents and preparing composites with hydrophilic oxides and solid proton conductors. DMFC and H2/O2(air) cells based on modified PFSA membranes have been successfully operated at temperatures up to 120 °C under ambient pressure...

A. Stambouli, E. Traversa

Quanjun Xiang, B. Cheng, Jiaguo Yu

P. Dodds, I. Staffell, A. Hawkes et al.

The debate on low-carbon heat in Europe has become focused on a narrow range of technological options and has largely neglected hydrogen and fuel cell technologies, despite these receiving strong support towards commercialisation in Asia. This review examines the potential benefits of these technologies across different markets, particularly the current state of development and performance of fuel cell micro-CHP. Fuel cells offer some important benefits over other low-carbon heating technologies, and steady cost reductions through innovation are bringing fuel cells close to commercialisation in several countries. Moreover, fuel cells offer wider energy system benefits for high-latitude countries with peak electricity demands in winter. Hydrogen is a zero-carbon alternative to natural gas, which could be particularly valuable for those countries with extensive natural gas distribution networks, but many national energy system models examine neither hydrogen nor fuel cells for heating. There is a need to include hydrogen and fuel cell heating technologies in future scenario analyses, and for policymakers to take into account the full value of the potential contribution of hydrogen and fuel cells to low-carbon energy systems.

Sivaprakash Sengodan, Sihyuk Choi, Areum Jun et al.

You Zhou, Xiaofei Guan, Hua Zhou et al.

Wen Wang, Ling Tao

I. Stephens, J. Rossmeisl, I. Chorkendorff

M. A. F. Akhairi, S. Kamarudin

Seungnam Yu, Geegum Lee, Jeongmok Kim

This study presents a VR-based teleoperation framework enhancing collaborative robot stability and manipulability via hand-tracking, adaptive control, and dual-modality haptic feedback. It addresses critical synchronization challenges (singularity avoidance, tracking responsiveness, and workspace constraints), which are especially problematic in first-person VR where kinematic limits are not directly perceivable. The framework employs Adaptive Damped Least Squares (A-DLS) to maintain manipulability near singular configurations, workspace impedance control to enforce boundary constraints, and vibrotactile feedback delivered through a haptic glove to convey both workspace limits (fingertip vibration) and path deviation information (wrist vibration) to operators. Key features include real-time hand-tracking, workspace calibration, and adaptive controls to ensure seamless coordination between virtual and real robot workspaces. Experimental validation through two complementary studies demonstrates the system’s effectiveness. Experiment 1 evaluated singularity management and workspace stability, showing that the A-DLS algorithm maintained manipulability above critical thresholds for 92% of operational time versus 78% without adaptive damping. Experiment 2 assessed trajectory tracking accuracy through a path-following task with 10 participants. Results demonstrate that haptic-enabled control achieves a 24.7% reduction in mean path-following error (from 10.03 mm to 7.55 mm, p = 0.001) compared to haptic-disabled conditions, indicating improvements in both accuracy and consistency. Although haptic guidance modestly increases task time due to higher precision focus, the resulting gains in accuracy and stability make this framework ideal for precision-critical tasks. By ensuring stability near workspace boundaries, the system effectively facilitates VR-based teleoperation for applications like painting, polishing, and contour-following.

T. Fletcher, R. Thring, M. Watkinson

Abstract The cost and reliability of fuel cells are major obstructions preventing fuel cell hybrid electric vehicle (FCHEV) from entering the mainstream market. However, many of the degradation methods are strongly affected by the operating conditions of the fuel cell and therefore can be mitigated by optimisation of the Energy Management Strategy (EMS). The major causes of fuel cell degradation are identified from the literature and a model is produced in order to estimate the effect of the EMS on the fuel cell degradation. This is used to produce an optimal strategy for a low speed campus vehicle using Stochastic Dynamic Programming (SDP). The SDP controller attempts to minimise the total running cost of the fuel cell, inclusive of both fuel consumption and degradation, each weighted by their respective costs. The new strategy is shown to increase the lifetime of the fuel cell by 14%, with only a 3.5% increase in fuel consumption, largely by avoiding transient loading on the fuel cell stack.

C. Asker, E. van Dongen, O. Tasse

<p>Air pollution adversely affects health, ecosystems, and infrastructure. In the <i>Western Balkans</i> (Albania, Bosnia and Herzegovina, Kosovo<span class="note-anchor" id="fna_Ch1.Footn1"><a href="#fn_Ch1.Footn1">¹</a></span>, Montenegro, the Republic of North Macedonia, and Serbia), the air pollution situation is more adverse than in the European Union in general. Understanding the air quality situation requires high-quality emission data with a high-resolution spatial distribution, especially for enabling remediation efforts, which is lacking in the Western Balkan region.</p> <p>In this work, we have calculated air pollution emissions from the heating of individual housing units in the Western Balkan region. The basis for the dataset is a geographical dataset of buildings detected from satellite imagery by artificial intelligence (AI) methods. The building data have been combined with geospatial land-use datasets and statistical data for heating needs for residential buildings in the countries included and finally with emission factors to calculate the heating emissions.</p> <p>Using this novel approach, the resulting datasets provide high-resolution heating emission data for common pollutants and are published as open data (<a href="https://doi.org/10.5281/zenodo.13906810">https://doi.org/10.5281/zenodo.13906810</a>, <span class="cit" id="xref_altparen.1"><a href="#bib1.bibx2">Asker</a>, <a href="#bib1.bibx2">2024</a></span>). When comparing national totals for emissions, the datasets in this work are comparable to other, spatially coarser datasets, though the agreement strongly depends on the fuel usage data for each country/region.</p>

Solecka Adriana, Gworek Barbara, Gabryszewska Marta

Fly ash, as waste generated from the combustion of coal and other solid fuels, is an important topic in the context of a circular economy in any industry. There are many variables that affect the amount of waste generated, including the type and quality of fuel and the efficiency of dust collection systems. Statistics on the consumption of coal and lignite in Poland, as well as other sources of waste (such as municipal and sewage sludge) indicate a significant amount of fly ash produced.

Haobo Li, Yicheng Zhu, Zihan Zhao et al.

Abstract Ionic transport in solids is a critical process for energy devices including batteries and fuel cells. To improve ionic transport, an emerging approach is the selective excitation of atomic vibrations related to the mobile ions. However, there is limited direct experimental evidence demonstrating enhanced macroscopic ionic conductivity through this approach. Here, we use a 140 mW continuous-wave mid-infrared (MIR) light to excite the O–H stretch vibration in proton-conducting yttrium-doped barium zirconate. We observe reversible enhancement of 36.8% in bulk, and 53.0% in grain boundary proton conductivities, controlled by MIR irradiation. Decreases in the activation energy and prefactor for bulk proton conduction suggest possible reduction in activation entropy and attempt frequency of proton hopping. We rationalize the enhancement as the excitation of O–H stretch vibrational states, followed by the relaxation into lattice vibration modes, modulating the potential energy surface of the proton. Our findings highlight MIR irradiation as a power-saving strategy to optimize the performance and operation cost of solid-state electrochemical devices by selective modulation of the vibrational properties.