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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=PHNlYXJjaD48cGFyYW1zPjxwYXJhbSBuYW1lPSJkYXRlaW4iIHZhbHVlPSJhbGwiIC8+PHBhcmFtIG5hbWU9InN1YmplY3Rsb2dpYyIgdmFsdWU9Im9yIiAvPjxwYXJhbSBuYW1lPSJ0ZXJtc2xvZ2ljIiB2YWx1ZT0ib3IiIC8+PHBhcmFtIG5hbWU9ImxvY2F0aW9uIiB2YWx1ZT0iMCIgLz48L3BhcmFtcz48ZmlsdGVycz48ZmlsdGVyIGZpZWxkPSJpbmRleHRlcm1zIiB2YWx1ZT0iJnF1b3Q7RXh0ZXJuYWwgY29tYnVzdGlvbiBlbmdpbmVzJnF1b3Q7IiBvcmlnaW5hbF92YWx1ZT0iJnF1b3Q7RXh0ZXJuYWwgY29tYnVzdGlvbiBlbmdpbmVzJnF1b3Q7IiAvPjwvZmlsdGVycz48cmFuZ2VzIC8+PHNvcnRzPjxzb3J0IGZpZWxkPSJwdWJsaXNoZWQiIG9yZGVyPSJkZXNjIiAvPjwvc29ydHM+PHBlcnNpc3RzPjxwZXJzaXN0IG5hbWU9InJhbmdldHlwZSIgdmFsdWU9InB1Ymxpc2hlZGRhdGUiIC8+PC9wZXJzaXN0cz48L3NlYXJjaD4=" 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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      <title>Misfire Detection in Automotive Engines Using a Smartphone through Wavelet and Chaos Analysis</title>
      <link>https://trid.trb.org/View/2002314</link>
      <description><![CDATA[Besides the failures that cause accidents, there are the ones responsible for preventing the car’s motion capacity. These failures cause inconveniences to the passengers and expose them to the dangers of the road. Although modern vehicles are equipped with a failure detection system, it does not provide an online approach to the drivers. Third-party devices and skilled labor are necessary to manage the data for failure characterization. One of the most common failures in engines is called misfire, and it happens when the spark is weak or inexistent, compromising the whole set. In this work, two algorithms are compared, based on Wavelet Multiresolution Analysis (WMA) and another using an approach performing signal analysis based on Chaos using the density of maxima (SAC-DM) to identify misfare in a combustion engine of a working automotive vehicle. Experimental tests were carried out in a car to validate the techniques for the engine without failure, with failure in one piston, and with two failed pistons. The results made it possible to obtain the failure diagnosis for 100% of the cases for both WMA and SAC-DM methods, but a shorter time window when using the last one.]]></description>
      <pubDate>Wed, 17 Aug 2022 09:33:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2002314</guid>
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    <item>
      <title>Development of High Pressure H2 Gas Injectors, Capable of Injection at Large Injection Rate and High Response Using a Common-rail Type Actuating System for a 4-cylinder, 4.7-liter Total Displacement, Spark Ignition Hydrogen Engine</title>
      <link>https://trid.trb.org/View/1823834</link>
      <description><![CDATA[Key requirements of engines for vehicles are large output power and high efficiency, low emission as well as small size and light weight. Hydrogen combustion engines with direct injection have the characteristics to meet these factors. Tokyo City University, former Musashi Institute of Technology, has studied hydrogen fueled engines with direct injection since 1971. The key technology in the development of hydrogen fueled engines is the hydrogen injector for direct injection with the features such as high injection rate, high response and no hydrogen gas leakage from the needle valve of the hydrogen injector. A common-rail type system to actuate the needle valves of the high pressure hydrogen injectors was intentionally applied to fulfill good performances such as large injection rate, high response and no hydrogen gas leakage. Eventually, high pressure hydrogen injectors have been developed for direct hydrogen engines at the injection pressure of 20 MPa at the maximum, capable of performing large injection rate, high response and no hydrogen gas leakage from the hydrogen needle valves. The leakage of hydrogen gas was not observed definitely for such time as 700 hours.]]></description>
      <pubDate>Fri, 17 Jun 2022 09:20:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1823834</guid>
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    <item>
      <title>Evaluation of Performance and Emission Characteristics of an Unmodified Naturally Aspirated Compression Ignition Engine on Blends of Diethyl Ether and Diesel</title>
      <link>https://trid.trb.org/View/1829724</link>
      <description><![CDATA[The world today is majorly dependent upon fossil fuels for power generation, of which diesel forms an integral part. Diesel engines, having the highest thermal efficiency of any regular internal or external combustion engine, are widely used in almost all walks of life and cannot be dispensed with in the near future. However, the limited availability of diesel and the adverse effects of diesel engine emissions like nitrogen oxide (NOx) and soot particles raise serious concerns. Hence, their performance and emission improvement continues to be an avenue of great research activity. In this research work, the effects of blending Diethyl Ether with diesel in various proportions (5%, 10%, 15% and 20% by volume) were evaluated on engine performance and emissions of an industrial internal combustion engine. Several properties of DEE such as its low viscosity, high volatility, high cetane number, low auto ignition temperature and high solubility in diesel make it favorable for use in compression ignition engines. The data obtained from experimentation were carefully studied and a detailed theoretical analysis was carried out for each of the blends by comparing with baseline diesel performance data. The results were promising. The DEE blends showed a simultaneous decrease in carbon monoxide, unburned hydrocarbon, smoke emissions and brake thermal efficiency whereas the brake specific fuel consumption and the NOx emissions showed an increase. It was concluded that the 5% DEE-Diesel blend is the most effective combination from the performance and emission point of view.]]></description>
      <pubDate>Thu, 09 Dec 2021 10:37:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1829724</guid>
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    <item>
      <title>An Analysis of the Parallel Combustion Two-Stroke Engine</title>
      <link>https://trid.trb.org/View/1786525</link>
      <description><![CDATA[The Parallel Combustion Two-Stroke is an internal combustion engine utilizing a hypocycloid gear mechanism and parallel combustion chambers. The hypocycloid mechanism provides mechanical balance and linear rod motion which eliminates piston sidewall forces and creates two chambers in the working cylinder. These two chambers are connected to combustion chambers external to the working cylinder. The resulting engine operates on a two-stroke cycle with many of the advantages of a four-stroke engine. It operates as an internal combustion engine with many of the advantages of an external combustion engine. And it operates as a reciprocating engine with the dynamic balance of a rotary engine.]]></description>
      <pubDate>Thu, 09 Dec 2021 10:17:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/1786525</guid>
    </item>
    <item>
      <title>Sound Quality Evaluation Method for Engine Combustion Noise in an Engine Acoustic Test Cell</title>
      <link>https://trid.trb.org/View/1856247</link>
      <description><![CDATA[In order to efficiently enhance engine sound quality under acceleration, the authors have developed an evaluation method for primary judgment of the sound quality of engine combustion noise at the stage of advanced engine development before the prototype vehicle is built. This method is an application of an existing method for evaluating the sound quality of engine combustion noise in vehicle interiors to the evaluation of noise and vibration at an engine acoustic test bench. In this method, it is necessary to consider the air-borne and the structure-borne components separately. The analysis procedure for the air-borne component is as follows. First, the sound pressure at a point 1 m away from the engine and the in-cylinder pressure of each cylinder are measured simultaneously in a semi-anechoic engine dynamometer test chamber. Next, the signal correlated with engine combustion is extracted from the measured sound pressure using the time domain combustion noise separation method. Then the obtained signal is converted into the equivalent signal of combustion noise in the vehicle interior using an acoustic filter that simulates the standard vehicle response characteristic. Finally, its sound quality is quantified using the existing sound quality index for combustion noise in the vehicle interior. The analysis procedure for the structure-borne component is the same as that for the air-borne component, except that vibro-acceleration at the engine mount is measured instead of measuring the sound pressure of the engine-radiated noise. This paper presents an overview of this method, introduces an example of application of the method to advanced engine development, and discusses the effectiveness of the method in automotive development.]]></description>
      <pubDate>Tue, 26 Oct 2021 14:30:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1856247</guid>
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    <item>
      <title>Forecasting the development trend of low emission vehicle technologies: Based on patent data</title>
      <link>https://trid.trb.org/View/1768349</link>
      <description><![CDATA[With the increasing awareness of environmental protection, there is a consensus on developing low emission vehicle (LEV) technologies but the trend is unclear. The LEV technologies, including hybrid electric vehicle (HEV), battery electric vehicle (BEV), and fuel cell electric vehicle (FCEV) technology, are considered as alternative technologies for the conventional internal combustion engine vehicles (ICEVs). The purpose of the paper is to forecast the future development trend of drivetrain technologies. In doing so, a revised method of technological forecasting is proposed on the basis of the S-curve simulation for growth curves and entropy weight method for ranking candidates, which leads to forecasting results are more objective and accurate. The authors findings highlight that HEV has the most promising future, followed by BEV and ICEV, but FCEV develops slowly. The implications are that policymakers should maintain the principle of technology-neutral when implementing various policies, while enterprises should be aware of the hybridization trend of vehicles in the business strategy-making process.]]></description>
      <pubDate>Wed, 09 Jun 2021 17:19:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1768349</guid>
    </item>
    <item>
      <title>Equivalence Ratio-EGR Control of HCCI Engine Operation and the Potential for Transition to Spark-Ignited Operation</title>
      <link>https://trid.trb.org/View/1776859</link>
      <description><![CDATA[This research investigates a control system for HCCI engines, where equivalence ratio, fraction of EGR and intake pressure are adjusted as needed to obtain satisfactory combustion. HCCI engine operation is analyzed with a detailed chemical kinetics code, HCT (Hydrodynamics, Chemistry and Transport), that has been extensively modified for application to engines. HCT is linked to an optimizer that determines the operating conditions that result in maximum brake thermal efficiency, while meeting the peak cylinder pressure restriction. The results show the values of the operating conditions that yield optimum efficiency as a function of torque and rpm. The engine has high NOᵪ emissions for high power operation, so the possibility of switching to stoichiometric operation for high torque conditions is considered. Stoichiometric operation would allow the use of a three-way catalyst to reduce NOᵪ emissions to acceptable levels. Finally, the paper discusses the possibility of transitioning from HCCI operation to SI operation to achieve high power output.]]></description>
      <pubDate>Fri, 26 Mar 2021 17:47:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1776859</guid>
    </item>
    <item>
      <title>Performance of Additive Manufactured Stacks in a Small Scale Thermoacoustic Heat Engine</title>
      <link>https://trid.trb.org/View/1631166</link>
      <description><![CDATA[Thermoacoustic heat engines (TAHEs) are external combustion engines primarily designed to convert thermal power into acoustic power and, eventually, into mechanical, electric or other forms of high grade power. TAHEs rely on the presence of a porous core, often referred to as “stack”. A temperature gradient is established along the porous core and quasi-adiabatic heat exchanges occur between the solid walls of the pores and the surrounding gaseous medium undergoing pressure fluctuations. The internal geometry of the stack has tremendous impact on the efficiency of thermal-to-acoustic power conversion.         In this study, the selective laser melting (SLM) has been used to produce stacks. The SLM is an additive manufacturing (AM) technique designed for 3D metal printing. It is based on high power- density laser which melts and fuses metallic powders together. Three sets of stacks, provided with different hydraulic radii and internal geometries, have been produced. Each set is constituted by two stacks with similar hydraulic radii, one with internal parallel plates and one with internal oblique pin array. The SLM provides precise control of the features of the printed object, allowing to explore geometries which are difficult to manufacture with conventional technologies but, possibly, more effective in the heat exchange process. This is the case of pin (and oblique pin) array geometries, which provide a reduced amount of viscous losses when the working fluid has Prandtl number Pr < 1, e.g. air.         The printed stacks have been tested in a small scale standing-wave TAHE set up in Tallinn University of Technology (TalTech). Temperatures are monitored in proximity of the hot and cold heat exchangers, as well as the sound pressure within the engine resonator. The measured quantities are shown in time and frequency domain to analyze the onset and the stability of the thermoacoustic phenomenon.       ]]></description>
      <pubDate>Tue, 27 Aug 2019 09:20:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1631166</guid>
    </item>
    <item>
      <title>Understanding the Surprising and Oversized Use of Ridesourcing Services in Poorer Neighborhoods in NYC</title>
      <link>https://trid.trb.org/View/1595116</link>
      <description><![CDATA[Initial studies of ridesourcing services found that early adopters were relatively affluent, educated, young urbanites willing to experiment with new smartphone-enabled technologies. Similarly, early studies undertaken in settings like San Francisco reinforced this description of the customer base and added that services were most typically used for shopping and leisure trips on evenings and weekends. It was therefore surprising to the project team that in the five boroughs of New York City, preliminary research that the project team has undertaken revealed that a majority of ridesourcing trips in 2017 originated in the outer boroughs in neighborhoods, predominantly populated by relatively low-income minority residents with limited access to public transit. It is unclear whether the trips are being taken by local residents to fill a gap that exists in public transportation services or by people outside the community for other reason(s). If ridesharing is being used to provide desired levels of accessibility, then having this need filled by for-profit entities could have long-term negative consequences for transportation equity. This project will use surveys, interviews, and spatial analysis of geocoded Twitter feeds about various companies providing ridesourcing to glean insights about these trips. The project team is especially interested in learning what has caused this rapid growth in trips originating in the outer boroughs, who is taking the trips, where they are going, and whether or not this represents additional travel or whether it is replacing trips already undertaken via different means. The project team's findings will provide insights about the implications of these ridesourcing trips for equity considerations, as well as externalities caused by any increased Vehicle Miles Travelled (VMT) that will be of interest to policy-makers. The mixed method spatiotemporal tools developed in this study will be applicable to a wide range of settings and illustrate the importance of contextual factors in evaluating the impacts of technologies that are disrupting the traditional landscape of transportation research and policy.]]></description>
      <pubDate>Mon, 25 Mar 2019 09:55:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/1595116</guid>
    </item>
    <item>
      <title>Air-Steam Hybrid Engine: An Alternative to Internal Combustion. Cleaner, More Efficient,
Multi-Fuel Compatible, Retrofitable</title>
      <link>https://trid.trb.org/View/1373030</link>
      <description><![CDATA[In this Small Business Innovation Research (SBIR) Phase 1 project, an energy-efficient air-steam propulsion system has been developed and patented, and key performance attributes have been demonstrated to be superior to those of internal combustion engines. A mixed air-steam propellant system can provide immediate power without a boiler, and that power can be varied simply by modifying the ratio of water and air in the propellant mix. Next steps for this innovation include more detailed performance verification and an analysis of scaling this promising technology to propel buses and trains for mass transit use. Successful validation would lead to a vehicle retrofit of a smaller, lighter, more fuel efficient engine in a standard mid-size or full-size vehicle. That engine could operate on a variety of fuels other than refined petroleum. These goals are consistent with the DOT SBIR subtopic narrative, “Economical and durable technologies and devices for improving safety for riders and transit agency employees, reducing noise and energy consumption, or improving the rider experience. The innovations must be adaptable to existing bus and rail transit vehicles and systems.]]></description>
      <pubDate>Sat, 07 Nov 2015 17:59:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/1373030</guid>
    </item>
    <item>
      <title>Air-Steam Hybrid Engine:
An Alternative to Internal Combustion</title>
      <link>https://trid.trb.org/View/1212640</link>
      <description><![CDATA[In this Small Business Innovation Research (SBIR) Phase 1 project, an energy-efficient air-steam propulsion system has been developed and patented, and key performance attributes have been demonstrated to be superior to those of internal combustion engines. A mixed air-steam propellant system can provide immediate power without a boiler, and that power can be varied simply by modifying the ratio of water and air in the propellant mix. Next steps for this innovation include more detailed performance verification and an analysis of scaling this promising technology to propel buses and trains for mass transit use. Successful validation would lead to a vehicle retrofit of a smaller, lighter, more fuel efficient engine in a standard mid-size or full-size vehicle. That engine could operate on a variety of fuels other than refined petroleum. This report includes a test of the Binary Recovery, Air-Steam Hybrid (BRASH) engine.  After making necessary mechanical and electronic modifications to a Smart™ sized test vehicle, two experiments were performed to validate the air-steam propulsion system operation and determine key baseline performance parameters. The first test run was to establish minimum fuel and propellant flow rates for sustained operation at low speed (air-rich mode), and the second to establish reasonable upper limits of fuel and propellant flow at higher engine speeds (steam-rich mode).]]></description>
      <pubDate>Fri, 14 Sep 2012 11:14:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1212640</guid>
    </item>
    <item>
      <title>Managing Carbon Monoxide Pollution in Meteorological and Topographical Problem Areas</title>
      <link>https://trid.trb.org/View/900210</link>
      <description><![CDATA[This executive summary is provided by the National Academies as part of their mission to educate the world on issues of science, engineering, and health. The regulation of carbon monoxide has been one of the great success stories in air pollution control. While more than 90 percent of the locations with carbon monoxide monitors were in violation in 1971, today the number of monitors showing violations has fallen to only a few, on a small number of days and mainly in areas with unique meteorological and topographical conditions. The publication describes how a primary objective of air quality management in the United States has been to reduce human exposure to carbon monoxide (CO) and other pollutants produced from incomplete combustion. Elevated ambient CO concentrations are due mainly to incomplete combustion of gasoline by light-duty vehicles, such as passenger cars and pickup trucks. CO controls are working. Problems with ambient CO were widespread when automobile emissions regulations began in the 1960s. When the health-based National Ambient Air Quality Standards (NAAQS) for CO were promulgated in 1971, more than 90% of ambient monitors indicated violations. Since then, motor-vehicle emissions controls have greatly reduced ambient CO concentrations. Over the last 5 years, the number of monitors showing CO violations has fallen to only a few, and the monitors that continue to show violations do so much less frequently. For example, Denver, Colorado, which had a persistent CO problem and registered as many as 200 days with violations in the 1960s, has not had a violation since 1995. Fairbanks, Alaska, reduced the number of days with violations from well over 100 per year in the early 1970s to zero over the last 2 years. Thus, CO regulation has been one of the greatest success stories in air pollution control, reducing the problem, once widespread, to a few difficult areas. As a result, the focus of U.S. air quality management has shifted to characterizing and controlling other pollutants, such as tropospheric ozone, fine particulate matter (PM2.5), and air toxics.]]></description>
      <pubDate>Fri, 18 Sep 2009 07:07:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/900210</guid>
    </item>
    <item>
      <title>Model-Based Fault Diagnosis in Electric Drive Inverters Using Artificial Neural Network</title>
      <link>https://trid.trb.org/View/896150</link>
      <description><![CDATA[This paper presents research in model-based fault diagnostics for the power electronics inverter-based induction motor drives. A normal model and various faulted models of the inverter-motor combination were developed, and voltages and current signals were generated from those models to train an artificial neural network for fault diagnosis. Instead of simple open-loop circuits, our research focuses on closed-loop circuits. Our simulation experiments show that this model-based fault diagnostic approach is effective in detecting single switch open-circuit faults as well as post-short-circuit conditions occurring in power electronics inverter-based electrical drives.]]></description>
      <pubDate>Fri, 24 Jul 2009 09:16:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/896150</guid>
    </item>
    <item>
      <title>EVALUATION OF HEAT EVALUATION OF HEAT ENGINE FOR HYBRID VEHICLE APPLICATION</title>
      <link>https://trid.trb.org/View/265848</link>
      <description><![CDATA[The status of ongoing heat-engine developments, including spark-ignition, compression-ignition, internal-combustion, and external-combustion engines is presented.  The potential of engine concepts under consideration for hybrid vehicle use is evaluated, using self-imposed criteria for selection. The deficiencies of the engines currently being evaluated in hybrid vehicles are discussed.  Focus is on recent research with two-stroke, rotary, and free-piston engines. It is concluded that these engine concepts have the most promising potential for future application in hybrid vehicles. Recommendations are maade for analysis and experimentation to evaluate stop-start and transient emission behavior of recommended engine concepts.]]></description>
      <pubDate>Fri, 27 Aug 2004 20:56:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/265848</guid>
    </item>
    <item>
      <title>GOALS AND GUIDELINES: RANKINE CYCLE PROPULSION SYSTEMS FOR APPLICATION TO URBAN BUSES AND OTHER HEAVY-DUTY VEHICLES</title>
      <link>https://trid.trb.org/View/9753</link>
      <description><![CDATA[Preliminary goals and guidelines are presented for the development of low-emission Rankine Cycle Engine (RCE) external combustion propulsion systems for urban transit vehicles.  Both interim and long-range goals for power systems are described, so that development can progress toward prototypes having properties acceptable to fleet operations.  The general guidelines cover only RCE power plants, although guidelines for other external combustion systems are recommended.  Principal areas covered in the report include:  (1) a description of the bus and its characteristics; (2) general power system requirements; (3) performance criteria; (4) fuels and fuel economy; (5) objectives for reduction of emissions, noise, and heat release; (6) operational safety; (7) operating characteristics; (8) reliability and maintenance factors; (9) resources and materials utilization; (10) production consideration; (11) cost projections; and (12) applications.]]></description>
      <pubDate>Sat, 18 Oct 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/9753</guid>
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