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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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    <language>en-us</language>
    <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>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Aviation climate impact and opportunities for mitigation</title>
      <link>https://trid.trb.org/View/2752068</link>
      <description><![CDATA[Climate impact from aviation is an ever-growing concern, driven by the continued increase in air traffic and associated emissions. The climate impact extends beyond carbon dioxide (CO2), with non-CO2 emissions and contrail formation together constituting a substantial share of the sector's total anthropogenic radiative forcing. This thesis develops methods to evaluate the different contributions to aviation-induced climate impact, with particular emphasis on non-CO2 effects. It then describes the metrics used to compare emissions with fundamentally different characteristics. Mitigation pathways aimed at reducing aviation's overall climate footprint are evaluated. Special focus is placed on contrails, which represent a highly variable but potentially dominant component of aviation's climate impact and offer opportunities for mitigation through targeted operational measures. The climate impact of Swedish aviation is assessed and attributed to individual emission species, highlighting the significant contribution of non-CO2 effects and the strong spatial, temporal, and seasonal variability of contrail formation. The results indicate that a relatively small subset of flights is responsible for a disproportionate share of contrail-induced warming, suggesting that selective contrail avoidance strategies could yield substantial climate benefits with limited operational disruption and cost. In addition to operational measures, this thesis investigates technological solutions, with a detailed analysis of the Water Enhanced Turbofan (WET) engine concept, which has been proposed as a means to reduce fuel burn as well as emissions of nitrogen oxides (NOx) and contrails. The performance and thermodynamic constraints of the WET engine are evaluated, showing that installation effects may offset its previously predicted advantages. Overall, the findings in this thesis underscore the importance of addressing non-CO2 effects in aviation climate assessments and demonstrate that both targeted operational strategies and careful evaluation of emerging technologies are essential for achieving meaningful reductions in the sector's climate impact.]]></description>
      <pubDate>Fri, 07 Aug 2026 08:36:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2752068</guid>
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    <item>
      <title>Ground State Theory Study of Aircraft Fuel Tank Cool-Oxygen Reductive Inerting System</title>
      <link>https://trid.trb.org/View/2654546</link>
      <description><![CDATA[The performance of an aircraft fuel tank inerting system is critical to aircraft safety. To explore a novel aircraft fuel tank inerting method, this paper proposes an inerting approach that integrates fuel-vapor condensation and oxidation. The working process of the cool-oxygen reductive inerting system is elaborated, and mathematical models for each component of the system are developed based on the principles of mass conservation and energy conservation. The dynamic simulation toward equilibrium is conducted using Modelica, and the impact of key system component parameters on the inerting performance is systematically analyzed. The results show that the higher the compressor pressure ratio is, the slower the oxygen concentration in the tank decreases, and the effect on the fuel-vapor concentration is not significant. The higher the pumping flow rate of the system, the better the inerting effect of the tank, but the higher the compressor power consumption. Improving the efficiency of the catalytic reactor can further improve the conversion rate of fuel vapor and oxygen to shorten the inerting time.]]></description>
      <pubDate>Mon, 02 Feb 2026 09:32:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2654546</guid>
    </item>
    <item>
      <title>Developing a Research Agenda on Contrails and Their Climate Impacts</title>
      <link>https://trid.trb.org/View/2590594</link>
      <description><![CDATA[Contrails are visible lines in the sky behind aircraft that occur when warm jet engine exhaust meets the colder surrounding atmosphere, forming small ice crystals. Most contrails dissipate within about 10 minutes, but they can last for hours under certain conditions. Persistent contrails can contribute to atmospheric warming and are estimated to have a climate impact on par with carbon dioxide emissions from aviation. In early 2024, NASA requested that the National Academies develop a national research agenda to better understand, quantify, and develop technical and operational solutions to reduce the global climate impact of aviation-induced cloudiness and persistent contrails. This report presents priorities for a national contrails research strategy and provides a vision for how this research could eventually support operational contrails mitigation. This research would support the global economic competitiveness of the U.S. civil aviation industry in the context of emerging international aviation regulations.]]></description>
      <pubDate>Mon, 08 Sep 2025 14:53:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2590594</guid>
    </item>
    <item>
      <title>A Study on Water Content in Lubricating Oil of Hydrogen-fueled Medium Duty Vehicle on Demonstration</title>
      <link>https://trid.trb.org/View/2535992</link>
      <description><![CDATA[A demonstration test was conducted using a heavy-duty vehicle equipped with a hydrogen engine to transport cargo from summer to winter. A sampling survey of the lubricating oil revealed that the amount of water in the oil increased during the winter season. The water condensing in oil showed a strong relationship with both exhaust gas temperature and humidity. It was shown that water condenses in the oil when the temperature of the oil was lower than the dew point of blow-by gas. This result described that heating oil is effective for preventing oil from emulsifying in winter.]]></description>
      <pubDate>Mon, 14 Apr 2025 09:35:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2535992</guid>
    </item>
    <item>
      <title>Statistical Validation of a Global Meteorological Database to Evaluate the Condensation Probability of Containers</title>
      <link>https://trid.trb.org/View/2528378</link>
      <description><![CDATA[Many studies have been conducted on optimal ship routing to evaluate zero emissions for advancing marine transportation. At the same time, the persistent challenge of condensation within loaded containers remains unresolved. This study introduces a novel perspective by considering the minimization of condensation risk as a key factor in evaluating containerized transport conditions. To achieve this, the authors conducted onboard weather parameters measurements on a 20,000 TEU container ship to determine the spatiotemporal variations of air conditions and condensation probabilities during a voyage between Far East Asia and Europe. First, the accuracy of the measured results was compared with the European Center for Medium-Range Weather Forecasts Reanalysis v5 (ERA5) for each season and sea region. Second, the condensation probabilities were compared for each voyage. Results revealed that the error in ERA5 increased in narrow channels, and solar radiation exhibited some differences in each season and sea region. ERA5 overestimated the condensation probability by 9—28% compared with the measured results owing to the error in solar radiation. Thus, solar radiation is the key factor affecting the condensation inside containers.]]></description>
      <pubDate>Thu, 03 Apr 2025 09:07:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/2528378</guid>
    </item>
    <item>
      <title>Development of Analyzing Method of Condensation Water Splashing on Electric Parts in a Vehicle by Using MPS Method</title>
      <link>https://trid.trb.org/View/2444737</link>
      <description><![CDATA[FVM analysis technology is a simulation technology for dew condensation, but although this analysis method can predict the occurrence of dew condensation, it cannot reproduce the flow of condensed water caused by factors such as vehicle tilt and driving acceleration/deceleration. The authors developed the reproducing method of condensation water on the air conditioner ducts by adapting MPS method. The simulation results of the condensation water flow are similar as the actual vehicle test cases with vehicle tilts and driving situations.]]></description>
      <pubDate>Fri, 08 Nov 2024 15:50:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2444737</guid>
    </item>
    <item>
      <title>Enhancing Sustainable Aviation through Contrail Management – A Framework for Multiple Platforms</title>
      <link>https://trid.trb.org/View/2389163</link>
      <description><![CDATA[Effective contrail management while ensuring operational and economic efficiencies for flight services is essential for providing services with minimal adverse environmental impact. The paper explores various aspects of contrail management applicable to different platforms such as Unmanned vehicles, Commercial airliners, and Business & regional jets. The aspects unique to each platform such as flight levels of operation, fuel types, flight endurance and radius of operation have been analyzed. Expanse of 5G network is resulting in increased flight activity at flight levels not envisaged hitherto. The paper also dwells on the ramifications of the increased proliferation of different platforms at newer flight levels from the perspective of contrail management. This paper introduces a framework that integrates the dual objective of minimizing contrail effects while optimizing fuel consumption for commercial aircraft by considering various factors like flight levels, geothermal data, and flight time. The paper also examines challenges and strategies related to seamless implementation, thereby highlighting the framework’s potential to propel the aviation industry towards environmentally responsible and efficient practices.]]></description>
      <pubDate>Mon, 08 Jul 2024 09:08:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2389163</guid>
    </item>
    <item>
      <title>SegX-Net: A novel image segmentation approach for contrail detection using deep learning</title>
      <link>https://trid.trb.org/View/2350898</link>
      <description><![CDATA[Contrails are line-shaped clouds formed in the exhaust of aircraft engines that significantly contribute to global warming. This paper confidently proposes integrating advanced image segmentation techniques to identify and monitor aircraft contrails to address the challenges associated with climate change. The authors propose the SegX-Net architecture, a highly efficient and lightweight model that combines the DeepLabV3+, upgraded, and ResNet-101 architectures to achieve superior segmentation accuracy. The authors evaluated the performance of their model on a comprehensive dataset from Google research and rigorously measured its efficacy with metrics such as IoU, F1 score, Sensitivity and Dice Coefficient. The authors' results demonstrate that their enhancements have significantly improved the efficacy of the SegX-Net model, with an outstanding IoU score of 98.86% and an impressive F1 score of 99.47%. These results unequivocally demonstrate the potential of image segmentation methods to effectively address and mitigate the impact of air conflict on global warming. Using the authors' proposed SegX-Net architecture, stakeholders in the aviation industry can confidently monitor and mitigate the impact of aircraft shrinkage on the environment, significantly contributing to the global fight against climate change.]]></description>
      <pubDate>Mon, 18 Mar 2024 17:19:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2350898</guid>
    </item>
    <item>
      <title>Case Study of Water Condensation and Evaporation Effects on Tailpipe Continuous Mass Emission Calculations in a Gasoline Powertrain</title>
      <link>https://trid.trb.org/View/2341929</link>
      <description><![CDATA[Emissions development work for gasoline aftertreatment systems is often conducted in a laboratory on a chassis dynamometer. In this situation, extractive sample lines are frequently connected to the aftertreatment system before and after various components, such as a three-way catalyst, selective catalytic reduction substrate, and the like. This is done to measure the conversion efficiency of the aftertreatment system components as a function of time. The time series exhaust component concentration data, also referred to as continuous data, are combined with a measure of exhaust volumetric flowrate and used to calculate mass-based emissions. As gasoline powertrains become cleaner and produce lower levels of criteria emissions, the proximity (i.e., colocated or not colocated) of the volumetric flowrate and concentration measurements may affect the accuracy of the overall mass emission calculation. In this work, the authors investigate the effect of water condensation and evaporation on continuous mass emission calculations in a gasoline powertrain. A dual-pitot tube flowmeter system is implemented to measure differences in volumetric flowrate between two tailpipe locations in the same vehicle. It was found that carbon monoxide, ammonia, and formaldehyde are especially susceptible to impacts from water condensation and evaporation effects due to the timing of their emission within a drive cycle and/or their water solubility. The mass emission of ammonia in the case study vehicle, for example, was underpredicted by up to ~15% if the tailpipe measurements of its concentration and the exhaust gas volumetric flowrate were not colocated.]]></description>
      <pubDate>Wed, 21 Feb 2024 10:04:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2341929</guid>
    </item>
    <item>
      <title>Experimental Study on Water Condensation in Automotive Headlamp</title>
      <link>https://trid.trb.org/View/1820964</link>
      <description><![CDATA[In order to avoid the undesired side effect of water condensation occurring under special environment conditions in modern xenon lamps several modifications of the serial automotive headlamps were suggested. The suggestions consist of a) desired leakage in the cover, b) anti-fog coating and c) integrated ventilation tube. These strategies were tested using two types of serial head lamps applying a condensation cycle for the simulation of the urban condition. During this condensation cycle the thermodynamic parameters, like relative air humidity and temperature, were measured at different places in the head lamp and as function of time. The modification with the integrated ventilation tube is able to improve the serial head lamp significantly. The improvement in terms of water condensation for the modification using anti-fog coating depends from the number of cooling cycles. Unfortunately, the modification operating with a desired leakage does not lead to any improvement in comparison to the serial head lamp. Moreover, the condensation of water is more pronounced then in the serial lamp.]]></description>
      <pubDate>Wed, 10 Aug 2022 16:38:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1820964</guid>
    </item>
    <item>
      <title>A Reciprocating-Mechanism Driven Heat Loop for High Heat-Flux Thermal Management</title>
      <link>https://trid.trb.org/View/1795429</link>
      <description><![CDATA[A heat transfer device which employs a solenoid-operated reciprocating mechanism for driving liquid from the condenser section to the evaporator section is described. The heat transfer device is coined as the reciprocating-mechanism driven heat loop, which includes a hollow loop having an interior flow passage, an amount of working fluid filled within the loop, and a solenoid-operated reciprocating driver. The hollow loop has an evaporator section, a condenser section, and a liquid reservoir. The reciprocating driver is integrated with the liquid reservoir and facilitates a reciprocating flow of the working fluid within the loop, so that liquid is supplied from the condenser section to the evaporator section under a substantially saturated condition and the so-called cavitation problem associated with a conventional pump is avoided. Experimental study has been undertaken for a proof-of-concept solenoid-operated heat loop for high heat flux thermal management applications. Experimental results show that the heat loop worked very effectively and a heat flux as high as 300 W/cm2 in the evaporator section could be handled. A working criterion has also been derived, which provides a guidance for the design of a reciprocating-mechanism driven heat loop.]]></description>
      <pubDate>Tue, 26 Jul 2022 13:18:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1795429</guid>
    </item>
    <item>
      <title>The effect of additives on water vapor condensation on bituminous surfaces</title>
      <link>https://trid.trb.org/View/1900360</link>
      <description><![CDATA[Water condensation and freezing on asphalt roads can lead to slippery conditions, which are responsible for many winter accidents and have caused an overreliance on mostly environmentally damaging and pavement degrading deicing chemicals and salt, which requires active maintenance. Bitumen is a mechanically and chemically complex material mainly consisting of various hydrocarbon-based chemicals groups. Additionally, bitumen makes up approximately 5 wt.% of the asphalt concrete mixture because of its binder role and coating function of the aggregates, can control the bulk mechanical properties and surface properties of the asphalt mixture. Condensation as the first step and later freezing phenomena are investigated in this study and from ambient humidity toward understanding the fundamentals of icing on bituminous surfaces. Condensation experimental results show selective wettability of chemically and mechanically district bitumen surface domains. The effect of different bitumen modifiers of polyethylene terephthalate, polyamide (PA 66), polyacrylonitrile, and Sasobit wax at 1 wt.% were studied on condensation freezing and bitumen water affinity.]]></description>
      <pubDate>Thu, 20 Jan 2022 12:15:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1900360</guid>
    </item>
    <item>
      <title>Experimental Investigation of the Pressure Drop during Water Condensation inside Charge Air Coolers</title>
      <link>https://trid.trb.org/View/1847489</link>
      <description><![CDATA[This paper investigates the pressure drop with and without condensation inside a charge air cooler. The background to this investigation is the fact that the stored condensate in charge air coolers can be torn into the combustion chamber during different driving states. This may result in misfiring or in the worst-case lead to an engine failure. In order to prevent or reduce the accumulated condensate inside charge air coolers, a better understanding of the detailed physics of this process is required. To this end, one single channel of the charge air side is investigated in detail by using an experimental setup that was built to reproduce the operating conditions leading to condensation. First, measurements of the pressure drop without condensation are conducted and a good agreement with experimental data of a comparable heat exchanger reported in Kays and London [1] is shown. In case of condensation it is observed that the accumulated condensate leads to an increase in pressure drop. An equilibrium state is established between the condensate formed and the one discharged from the charge air cooler, which leads to pressure fluctuations. Furthermore, the amount of the accumulated condensate in the charge air cooler is considered when determining the Fanning friction factor. It is shown that with this consideration the two-phase pressure drop can be described by the single-phase Blasius approach in the investigated operating range of the charge air cooler. The mean deviation of the measured data from the correlation amounts to about 3.8%.]]></description>
      <pubDate>Tue, 26 Oct 2021 14:30:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1847489</guid>
    </item>
    <item>
      <title>A Mathematical Description of Water Vapor Mass Transfer for a Vented Automotive Lamp</title>
      <link>https://trid.trb.org/View/1847265</link>
      <description><![CDATA[Plastic automotive lamp assemblies are vented by a variety of methods to reduce the likelihood of condensation forming in the lamp and to prevent water ingress lamp warranty returns. Previously, it has been shown that the humidity in a vented automotive lamp can be described empirically by a decreasing exponential (i.e. decay). It was also shown that this formula by applying Fick’s Law of Diffusion, particularly the exponential constant (k), can be related to basic physical properties of the lamp system. Specifically, the exponential constant is a ratio of the product of a characteristic cross-section area of the vent and the permeability of water vapor over the product of the lamp volume and a characteristic length of the vent. This description was shown to be less accurate at time t greater than 30 minutes and additional details of the vented lamp system were proposed for better fit to the experimental data. This investigation proposes that the additional description for the vented lamp system is better associated with the absorption and desorption of water from the plastic parts of the lamp assembly. The water release from the plastic in the lamp can be described by an additional term supplying water vapor content to the lamp volume. Further, an investigation of the ratio of parameters defining the exponential constant of the water release from the lamp plastic components is addressed and compared to experiment. A discussion of this description’s limitations and use as an engineering design tool is included.]]></description>
      <pubDate>Wed, 29 Sep 2021 09:31:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/1847265</guid>
    </item>
    <item>
      <title>Dropwise condensation freezing and frosting on bituminous surfaces at subzero temperatures</title>
      <link>https://trid.trb.org/View/1860815</link>
      <description><![CDATA[Freezing of atmospheric water on bituminous construction and road surfaces is a recurring event during winter. However, droplet freezing on bitumen and passive inhibition methods are poorly understood. Here the authors investigate relative humidity and substrate cooling effects on condensation freezing on subzero temperature bituminous surfaces and find that droplet freezing is explosive, with rapid local heating. The authors explain the related physics and find that relative humidity and cooling rate can affect droplet sizes and freezing temperatures. The authors then rationally embed phase change material microcapsules in bitumen, harnessing their latent heat to significantly delay freezing, demonstrating a viable option for frost mitigation.]]></description>
      <pubDate>Fri, 23 Jul 2021 15:23:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1860815</guid>
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