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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Effect of Burning Biomass Fuel Cyclohexanol on Diesel Engine
                    Performance</title>
      <link>https://trid.trb.org/View/2706269</link>
      <description><![CDATA[Against the backdrop of growing global demands for energy sustainability and                     stricter emission regulations for diesel engines, this study investigates the                     performance implications of incorporating cyclohexanol—a renewable oxygenated                     fuel—into diesel fuel blends. Using a marine medium-speed diesel engine as the                     experimental platform, the research systematically evaluates engine performance                     and emission characteristics across a range of cyclohexanol-diesel blend ratios                     under low, medium, and high load conditions. Experimental findings reveal                     multifaceted effects of cyclohexanol blending on engine operation. Combustion of                     the blended fuels enhances the engine’s dynamic performance, particularly under                     medium and high loads, where the maximum in-cylinder burst pressure exhibits a                     noticeable increase. This improvement is attributed to cyclohexanol’s                     oxygen-carrying capacity, which promotes more vigorous and sustained combustion                     reactions. In terms of emissions, increasing the proportion of cyclohexanol in                     the fuel blend leads to significant reductions in soot and carbon monoxide (CO)                     emissions, reflecting the cleaner-burning properties of the oxygenated                     component. However, this is accompanied by an uptick in nitrogen oxide                         (NOx) emissions, likely due to the elevated combustion                     temperatures generated by the more efficient fuel oxidation process. From an                     economic perspective, cyclohexanol blending at consistent load levels induces a                     postponement in the crank angle at which peak heat release occurs during                     combustion. This temporal shift prolongs the effective combustion duration,                     enabling more complete fuel utilization within the cylinder. Consequently, fuel                     consumption rates decrease, and overall engine efficiency improves, highlighting                     the potential of cyclohexanol blends to enhance operational economy in marine                     propulsion systems. In summary, this study underscores the complex trade-offs                     associated with cyclohexanol-diesel blends: while they offer tangible benefits                     in power output, fuel efficiency, and reduced particulate emissions, managing                     the increase in NOx emissions remains a critical challenge. The                     results provide a foundational framework for advancing biofuel applications in                     marine engines, emphasizing the need for integrated emission control strategies                     to optimize the balance between performance and environmental                     sustainability.]]></description>
      <pubDate>Mon, 29 Jun 2026 09:11:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2706269</guid>
    </item>
    <item>
      <title>Effect of EGR Rate on Cyclohexanol-Diesel Dual-fuel
                    Engines</title>
      <link>https://trid.trb.org/View/2706266</link>
      <description><![CDATA[To reduce high NOx emissions from diesel-cyclohexanol blends, this                     study employed a marine medium-speed diesel engine as the experimental platform.                     An in-cylinder combustion model was developed and meshed using AVL - FIRE                     software, with model validity validated against experimental data. Tests were                     conducted at four load conditions (25%, 50%, 75%, and 100% load) with a 30%                     cyclohexanol blend (C30) and four EGR rates (0%, 7.5%, 10%, and 12.5%) to                     analyze combustion characteristics, emissions, and fuel economy. The results                     showed that the introduction of EGR had a striking inhibitory effect on                         NOx emissions. At 100% load with 12.5% EGR rate, NOx                     emissions were substantially reduced compared to baseline operation without EGR.                     However, EGR implementation led to delayed ignition timing, reduced in-cylinder                     pressure, and worsened fuel economy. Therefore, an appropriately calibrated EGR                     strategy can effectively reduce NOx emissions, though it requires                     optimization to mitigate adverse effects on combustion performance and                     efficiency.]]></description>
      <pubDate>Mon, 29 Jun 2026 09:11:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2706266</guid>
    </item>
    <item>
      <title>Alcohol Diffusive Combustion Technique as an Alternative Diesel Combustion (Third Report)</title>
      <link>https://trid.trb.org/View/2684155</link>
      <description><![CDATA[In this study, we prototyped a dual-fuel high-pressure pump and a dual-fuel injector that controls two fuels using a single needle valve and injects them through the same nozzle orifice. In-cylinder observations revealed that a pilot injection with a high diesel fuel content ignites the main injection of an ethanol–diesel mixture, thereby achieving diffusive combustion. Experiments were conducted at engine speeds of 1000 and 2000 rpm under low-load conditions, with coolant temperatures of 80 °C and 40 °C. The optimum pilot injection timing and quantity were experimentally determined using a single-cylinder direct-injection diesel engine, with the objective of minimizing combustion noise, smoke, and CO emissions.]]></description>
      <pubDate>Tue, 23 Jun 2026 13:53:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/2684155</guid>
    </item>
    <item>
      <title>Study on Biodiesel-Bunker Fuel Blends as Marine Pollutants: Blends of Biodiesels with Conventional Marine Bunker Fuels as Marine Pollutants and the Response Measures for Their Accidental Releases</title>
      <link>https://trid.trb.org/View/2677560</link>
      <description><![CDATA[This study was commissioned by the European Maritime Safety Agency (EMSA) under the framework contract EMSA/2024/OP/0023 to address critical knowledge gaps concerning alternative fuels as potential marine pollutants and the effectiveness of response measures in the event of accidental releases. As the maritime sector accelerates its transition towards decarbonisation—driven by the IMO Revised Strategy on the Reduction of GHG Emissions from Ships (2023) and the European Green Deal—the uptake of alternative fuels is increasing, while preparedness and response frameworks remain largely designed for conventional petroleum-based fuels. This study provides clear reassurance that the transition towards biodiesel blends as marine fuels can be supported by existing oil spill response frameworks, without the need for fundamentally new response systems. By optimising current technologies, adapting operational practices, and addressing identified regulatory gaps, authorities and operators can manage accidental releases effectively and proportionately. By integrating scientific evidence, regulatory analysis, stakeholder input, and practical recovery testing, this report delivers a comprehensive and actionable reference for authorities, operators, and responders. It supports informed decision-making at both operational and policy levels and provides a clear pathway for safely managing accidental releases of biodiesel blends while facilitating the maritime sector’s transition towards alternative fuels.]]></description>
      <pubDate>Mon, 15 Jun 2026 08:40:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2677560</guid>
    </item>
    <item>
      <title>Evaluate Standard vs Blended PG Binders 
Performance in NM
</title>
      <link>https://trid.trb.org/View/2704031</link>
      <description><![CDATA[The Superpave asphalt binder system was introduced in the 1990s to better handle different temperatures and traffic conditions. Since then, New Mexico has adopted the PG grading system for its roads. The PG binder bump is an effective way to increase the asphalt binder’s grade, improving high-temperature performance and making it suitable for high-temperature ranges. It can be achieved mainly in two ways: Standard PG: this involves blending a base asphalt binder (a soft binder from crude oil refining) with synthetic rubber or other chemical additives at terminals. These additives may include styrene butadiene styrene (SBS) polymer and polyphosphoric acid (PPA). Blended PG: This method uses a certain amount of RAP (Recycled Asphalt Pavements) and can also effectively bump the PG grade of the asphalt binder.]]></description>
      <pubDate>Wed, 20 May 2026 11:10:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2704031</guid>
    </item>
    <item>
      <title>Experimental Analysis and Numerical Simulation of the Performance Parameters of Tire Pyrolytic Oil in a Compression Ignition Engine</title>
      <link>https://trid.trb.org/View/2701257</link>
      <description><![CDATA[The search for alternative solutions for non-fossil fuels has led to several studies worldwide. This study focuses on environmentally responsible solutions to accelerate tire degradation, focusing on the transformation of these residues into fuel for diesel engines. The objective of this study was to experimentally evaluate, through numerical simulation, the performance of a compression ignition engine operating with pure diesel S10 fuel, crude and refined tire pyrolytic oil, and mixtures in proportions of 20, 40, 60, 80 and 100% with diesel oil. The experimental tests were performed on a single-cylinder engine coupled to a dynamometer bench, and the numerical simulation was performed using the Diesel Engine RK software. The experimental results indicated that increasing the proportion of refined pyrolytic oil in diesel slightly improves engine performance up to approximately 2750 RPM, after which the performance is reduced compared to pure Diesel. The addition of crude pyrolytic oil slightly improves engine performance throughout the engine operating range compared to pure diesel. The simulation results revealed performances similar to those obtained experimentally, with a highlight on the 20% blend ratio, which behaved similarly to Diesel. The research is relevant because valuable results were obtained in the search for more sustainable alternatives in the context of compression ignition internal combustion engines.]]></description>
      <pubDate>Mon, 18 May 2026 14:04:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/2701257</guid>
    </item>
    <item>
      <title>Mechanistic evaluation of reclaimed asphalt pavement (RAP) as base course: the role of binder aging in the response of RAP-virgin aggregate blends</title>
      <link>https://trid.trb.org/View/2663718</link>
      <description><![CDATA[This study investigates the influence of binder properties of reclaimed asphalt pavement (RAP) specifically binder content and oxidative aging on the performance of RAP-virgin aggregate (VA) blends through repeated load triaxial (RLT) testing. RAP samples from four regional sources were characterized using standard index property tests, binder content determination, and Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy to quantify binder aging via an aging index. RAP-VA blends were prepared at as-is gradations in proportions of 20%, 30%, 60%, and 80% RAP, and tested under stress conditions representing higher, medium, and low traffic pavement structures representative of Illinois pavement and traffic conditions. Results demonstrate that PD performance depends on the interplay between binder content and aging index, rather than binder content alone. RAP with higher aging indices consistently exhibited superior resistance to deformation, even at high RAP contents. The threshold RAP content for deformation resistance at optimum moisture and maximum dry density, beyond which permanent deformation begins to increase, was found to vary depending on the pavement structure and traffic level typically ranging from 20 to 40% for pavements with thicker asphalt layers (high-volume roads) and 20–80% for thinner asphalt layers (medium- to low-volume sections). This variation arises primarily from differences in the binder characteristics of each RAP source, including binder content and aging index. RAP with higher binder content or a more oxidized (aged) binder tends to exhibit a stiffer yet more brittle response, which alters the blend’s deformation behavior and shifts the threshold RAP content at which performance begins to decline.]]></description>
      <pubDate>Wed, 06 May 2026 08:54:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663718</guid>
    </item>
    <item>
      <title>Analysis of urban hydrogen-blended natural gas pipeline leak failure and accident evolution based on the combination of causal inference and probabilistic machine learning</title>
      <link>https://trid.trb.org/View/2664279</link>
      <description><![CDATA[Integrating hydrogen into urban gas pipeline networks is a pivotal technology for energy transition yet poses critical safety threats, thus necessitating comprehensive risk assessment of hydrogen-blended natural gas pipelines. This study performs full quantitative risk assessment of leakage failure and accident evolution by proposing a novel framework that integrates causal inference (Bow-Tie analysis) with probabilistic machine learning (Bayesian networks), enabling systematic failure factor identification and dynamic accident progression simulation. Key findings indicate human factors and pipeline material degradation as primary triggers. The studied pipeline exhibits a low baseline failure probability, with dispersion emerging as the most likely consequence of leakage. Higher hydrogen blending ratios significantly elevate jet fire risk due to hydrogen’s low ignition energy, while hydrogen’s inherent buoyancy and high diffusivity notably mitigate the likelihood of flash fire and vapor cloud explosion. The case study verifies the model’s practicability, and macro-micro analyses provide holistic insights, offering a reliable method to guide pipeline safety and reliability improvement amid energy transition.]]></description>
      <pubDate>Thu, 30 Apr 2026 11:28:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/2664279</guid>
    </item>
    <item>
      <title>A Short Review of Ammonia Compression Ignition Engines for an SOFC-ICE Power Plant for Shipping</title>
      <link>https://trid.trb.org/View/2580011</link>
      <description><![CDATA[Ammonia is considered one of the most promising hydrogen and energy carriers for decarbonizing deep-sea shipping and other remote heavy-duty applications. The AmmoniaDrive power plant concept uniquely combines Solid-Oxide Fuel Cell (SOFC) and Internal Combustion Engine (ICE) technology to address the issue of how to convert e-ammonia, produced from renewable resources, into useful on-board power safely and effectively, without the need for fossil fuels as combustion promotor. This paper introduces the AmmoniaDrive concept, outlines the challenging combustion properties of ammonia and ammonia-hydrogen mixtures and provides a short review of Compression Ignition ICE research for ammonia-fuelled engines. Three promising combustion concepts are introduced to give direction to further numerical and experimental research.]]></description>
      <pubDate>Thu, 23 Apr 2026 09:11:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2580011</guid>
    </item>
    <item>
      <title>Project 074 Low Emissions Premixed Combustion Technology for Supersonic Civil Transport</title>
      <link>https://trid.trb.org/View/2691547</link>
      <description><![CDATA[This project advanced the state-of-the-art in fuel-lean premixed prevaporized (LPP) combustor technology for use in future civil supersonic transport (CST) aircraft engines. Cruise conditions for CST aircraft are such that combustors operate in a different parameter space than combustors for traditional subsonic aircraft. These conditions lead to challenges meeting environmental targets, particularly regarding nitrogen oxides (NOx). LPP combustors can enable step-change improvements in NOx emissions, but have different operability constraints and less mature design tools compared to current combustor architectures. This project partnered advanced test facilities, state-of-the-art laser diagnostics, high-fidelity numerical simulations, and reduced order modeling to gain new insight regarding LPP combustor performance and develop/validate design tools. A  LPP combustor concept was designed, fabricated, commissioned, and tested. Laser diagnostics from were used to measure the velocity field, flame structure, fuel spray, fuel/air mixing, and other aspects of the combustor performance across operating conditions and with both conventional and sustainable aviation fuels. Emissions were in line with the National Aeronautics and Space Administration's (NASA's) ambitious targets for future CST aircraft. Operability limits, flame structure, and combustion dynamics were well-explained by theoretical considerations and reduced order models. The experimental data provided quantitative benchmarks for simulations, and identified areas for fruitful model improvement.]]></description>
      <pubDate>Mon, 20 Apr 2026 09:22:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2691547</guid>
    </item>
    <item>
      <title>Spray and combustion characteristics of F-T diesel blending oxygenated fuel based on constant volume combustion chamber</title>
      <link>https://trid.trb.org/View/2686854</link>
      <description><![CDATA[In this work, 20% of polymethoxy dimethyl ether (PODE) and n-butanol are blended with F-T diesel by volume, respectively, referred to as FP20 and FBU20. Based on the constant volume combustion chamber (CVCC), the spray characteristics and combustion characteristics of diesel, F-T diesel, FP20 and FBU20 under high ambient temperature and pressure are studied by using high-speed photography combined with Matlab image processing technology. Results show that the steady-state liquid spray tip penetration and spray projection area of FP20 and FBU20 are smaller than those of F-T diesel due to their good evaporation. Combustion characteristics studies show that compared to D100, the ignition delay and flame lift-off length of FT100 decrease by 22.9% and 43.6%, respectively. Compared to FT100, the flame lift-off length of FP20 and FBU20 increases by 36.8% and 44.1%, respectively. Due to the addition of high cetane number and high oxygen content PODE, the ignition delay of FP20 is shortened by 3.7%, and the ignition delay of FBU20 is prolonged by 40.1% due to the effect of high latent heat of vaporization and low cetane number of n-butanol. Compared to D100, the peak flame area of FT100 increases by 8.5%, while the peak flame luminosity decreases by 18.2%. Because PODE and n-butanol can improve evaporation and increase the oxygen content of fuel and then reduce the formation of soot, compared to FT100, the peak of flame area and flame luminosity of FP20 and FBU20 are decreased. The results of two-color method show that after adding PODE and n-butanol into F-T diesel fuel, the generation of soot and combustion temperature of the mixed fuel are reduced. Moreover, FP20 has higher oxygen content and better atomization characteristics, so the effect of reducing soot is better than that of FBU20.]]></description>
      <pubDate>Mon, 06 Apr 2026 08:52:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2686854</guid>
    </item>
    <item>
      <title>The impact of hydrogen percentage on the combustion, performance, and emissions of NG-H2-diesel naturally aspirated engine at high engine load</title>
      <link>https://trid.trb.org/View/2665918</link>
      <description><![CDATA[This research involved an experimental investigation of gradually increasing hydrogen (H2) percentage in fuel mixture on the combustion, performance, and emissions of H2-natural gas (NG)-diesel naturally aspirated engine at high load (20 kW). A mechanical diesel injection pump (MDIP) automatically controlled the diesel flow. Simultaneously, the NG was supplied with constant pressure and a fully open line, while a flow control valve and flowmeter adjusted the H2 flow rate. A gas-air mixer was positioned at the intake manifold to supply the engine with NG and H2, while the diesel was directly injected. The results indicated that increasing H2 in the fuel mixture reduces BSFC, CO, THC, and smoke, but increases in-cylinder peak pressure and NOX emissions. The detailed results are valuable and usable for industry implementations and upcoming scientific studies.]]></description>
      <pubDate>Mon, 23 Mar 2026 15:15:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2665918</guid>
    </item>
    <item>
      <title>Elucidating the Effects of Lower Boiling Point Fuel Blends on the Performance of a Heavy-Duty Diesel Engine</title>
      <link>https://trid.trb.org/View/2646089</link>
      <description><![CDATA[This study investigates the impact of synthetic fuel properties on improving the combustion and emissions of high-compression-ratio (CR) heavy-duty diesel engines. Diesel, DP2b (diesel + C₆H₁₄: 6:4 vol%), and DP3b (diesel + nC₇H₁₆: 6:4 vol%) fuels are tested in a single-cylinder CR=23 engine. A 3D-CFD model was calculated using CHEM-KIVA4 and Waseda’s phenomenological soot model. The results showed that the use of mixed fuels reduced Soot under each operating conditions. Comparison between experiments and calculations confirms that the reasons why soot is reduced with mixtures fuels are promotion of spray atomization and suppressing for soot particle nucleation and surface growth processes.]]></description>
      <pubDate>Fri, 20 Mar 2026 14:47:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2646089</guid>
    </item>
    <item>
      <title>Effect of Discharge Energy Enhancement on the Operating Characteristics of a Spark Ignition Engine Fueled with Ammonia/Hydrogen Mixture</title>
      <link>https://trid.trb.org/View/2646088</link>
      <description><![CDATA[Ammonia burning velocity is small and it makes stable operation of a spark ignition engine fueled with ammonia/hydrogen mixture difficult. To improve this, discharge energy is increased, and the effect on the operating characteristics is investigated. With the increase in ammonia equivalence ratio, the effect of change in molar number increases. However, with the increase in ammonia equivalence ratio, the effect of degree of constant volume and combustion efficiency decreases around the operation limit. Indicated thermal efficiency has a peak about ammonia equivalence ratio of 0.88. Discharge energy enhancement contributes to keeping degree of constant volume and combustion efficiency high.]]></description>
      <pubDate>Fri, 20 Mar 2026 14:47:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2646088</guid>
    </item>
    <item>
      <title>Comments on “Failure analysis of corroded hydrogen-blended natural gas pipelines based on finite element analysis and genetic algorithm-back propagation neural network” [262 (2025) 111174]</title>
      <link>https://trid.trb.org/View/2636766</link>
      <description><![CDATA[This is a brief commentary paper to highlight and discuss the determination of hydrogen concentration in pipeline steel, effect of hydrogen embrittlement (HE) on the mechanical properties of the material, burst strength of corroded pipelines using finite element analysis (FEA) simulations, and curve-fit models for assessing remaining strength of X80 corroded pipelines for transporting hydrogen blended natural gas. Recently, Xie et al. [1] proposed a methodology to quantify the impact of HE on material properties and numerically determined burst pressure of X80 corroded pipelines. However, their HE quantification overestimated the degradation of tensile strength for hydrogen blending ratios beyond the original data range, and their FEA results of burst pressure are nonconservative. This work thus recharacterized the hydrogen concentration in the steel pipeline and the effect of HE on tensile strength, and then redetermined burst pressures for a set of typical corrosion defect cases considered by Xie et al. [1] based on an experimentally validated FEA modelling method. With the new FEA results, two empirical corrosion models were proposed for X80 corroded pipelines for hydrogen service. At zero hydrogen blending ratio, the novel empirical models predict burst pressures to be consistent with the industry-accepted corrosion models. Both the numerical simulation method and the novel corrosion models are significant contributions to the pipeline industry and the hydrogen community. Application of these results will enhance the safety, reliability, and integrity of natural gas pipelines when used to transport hydrogen.]]></description>
      <pubDate>Wed, 25 Feb 2026 16:28:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2636766</guid>
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