<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <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>
    </image>
    <item>
      <title>Upstream Oxygen Sensor Signal Improvement Using the DFSS and Virtual Validation Approach</title>
      <link>https://trid.trb.org/View/2692151</link>
      <description><![CDATA[Combustion stability and emission control remain key challenges for gasoline engines, requiring robust oxygen sensing strategies. The primary function of the upstream exhaust oxygen sensor is to detect the oxygen concentration in exhaust gas for accurate air–fuel ratio control. However, poor signal visibility from individual cylinders across engine speeds can lead to improper combustion prediction and reduced engine efficiency. This work applies a Design for Six Sigma (DFSS) approach to optimize the upstream oxygen sensor configuration in a 2.0 L four-stroke gasoline engine. Conventionally, sensor placement is completed by iterative testing and calibration, which is both time-consuming and cost intensive. The DFSS framework uses input, output, control, and noise factors. Exhaust gas mass flow rate from engine cylinders at different speeds is treated as the input, while the detected oxygen mass fraction is the output. Design parameters such as pipe length, pipe diameter, sensor orientation, insertion depth, and location are considered control factors. Sensor element position and ambient temperature serve as noise factors, as they cannot be controlled directly by the engineer. The analysis is performed using three-dimensional computational fluid dynamics (CFD) and confirmed through Design of Experiments (DoE) simulations. The optimized configuration achieved improved sensor signal stability and cylinder visibility, enabling more reliable combustion control. This structured approach demonstrates how virtual analysis combined with DFSS principles can guide robust oxygen sensor placement strategies, reducing validation effort while enhancing engine efficiency and emissions performance.]]></description>
      <pubDate>Thu, 28 May 2026 17:09:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2692151</guid>
    </item>
    <item>
      <title>A Description and Analysis of the FAA Onboard Oxygen Analysis System</title>
      <link>https://trid.trb.org/View/2691553</link>
      <description><![CDATA[The Federal Aviation Administration (FAA) is planning a series of ground and flight tests with Airbus to prove the concept of a simplified fuel tank inerting system, which has been developed by the FAA. The FAA has also developed an onboard oxygen analysis system to measure the oxygen concentration in the aircraft fuel tank during the testing. To help ensure smooth integration and the safety of the testing, the FAA has documented the system description, interfaces, operation, and has performed a failure mode effects criticality analysis. This analysis attempts to identify the failure modes of each system component and assess the effects of these failures on the component, system, and aircraft. The analysis also applies a hazard category to each hazard as well as some hazard probability when it was deemed necessary by the author. Hazard controls are also listed. All relevant system information has been summarized to allow for the system to be properly integrated into the proposed flight test aircraft. The results of the analysis indicated that most failure modes had no effect on the aircraft or other secondary systems. The few hazards with potential aircraft effects have significant controls in place to reduce the likelihood of the hazard and mitigate any potential hazard exposure.]]></description>
      <pubDate>Mon, 04 May 2026 11:05:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/2691553</guid>
    </item>
    <item>
      <title>Limiting Oxygen Concentration Required to Inert Jet Fuel Vapors Existing at Reduced Fuel Tank Pressures</title>
      <link>https://trid.trb.org/View/2691548</link>
      <description><![CDATA[This report discusses experiments to determine the reduction in oxygen concentration required to prevent a fuel tank explosion. A simulated aircraft fuel tank containing JP-8 fuel of an amount equivalent to a mass loading of approximately 4.5 kg/m³  was used to determine the limiting oxygen concentration (LOC) at pressures corresponding to altitudes ranging from 0 to 38 kft. In addition, the peak pressure rise was measured at various altitudes (pressures) due to ignition occurring at O₂ levels approximately 1% to 1.5% above the LOC. A wide range of ignition sources was used throughout the testing. An oil burner transformer connected to an analog timer provided a low power arc of both short (0.1 second) and long durations (1 second), a spark igniter taken from a J-57 engine provided a very short duration (175 µseconds) high powered spark, and a heated metal block was used as a hot surface ignition source. These varied capabilities allowed for an evaluation of the variation in the LOC due to a specific type of ignition source. From these tests, it was determined that the LOC at sea level through 10 kft is approximately 12% O₂, while exhibiting a linear increase from 12% at 10 kft to approximately 14.5% at 40 kft. Tests with various sparks/arcs as ignition sources at sea level showed little variation in results, with the LOC ranging from 12.0% to 12.8%. Also, a heated surface capable of igniting a fuel air mixture proved insufficient for ignition in a tank inerted to just 14%. Peak pressures resulting from ignition at oxygen concentrations 1% to 1.5% above LOC values decreased as the altitude was increased to 30 kft, while the duration to reach the peak pressure increased.]]></description>
      <pubDate>Mon, 04 May 2026 11:05:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/2691548</guid>
    </item>
    <item>
      <title>Ignition characteristics of a Stirling engine in the oxygen and air modes</title>
      <link>https://trid.trb.org/View/2663666</link>
      <description><![CDATA[Stirling engine is characterized by its strong fuel adaptability, making it versatile across various operational scenarios. By operating the Stirling engine at high pressure O₂/CO₂ environment, the carbon dioxide concentration in the combustion products can be greatly increased, which is conducive to carbon capture. To improve the performance of Stirling engine, the ignition conditions of Stirling engine are compared in two combustion modes (the O₂/CO₂ combustion mode and air/CO₂ combustion mode). By simulating the ignition process of the Stirling engine in the two modes, the effects of different ignition power, ignition duration, and ignition position on the ignition process during engine start are analyzed. Moreover, the accuracy of the model is verified by experimental results. The findings indicate that in the process of restarting, the igniter is not required, and the ignition can be achieved by preheating in the cylinder. This discovery provides a way to improve the starting efficiency of Stirling engine. In the start process, the ignition success can be achieved by extending the ignition duration or increasing the ignition power, but there is a minimum ignition power limit of 900 W in the oxygen mode and 200 W in the air mode. Ignition position has significant influences on ignition success rate. Too low ignition position will cause the flame core to extinguish under the wash of high-speed air flow, and too high ignition position will prevent the spread of flame, and therefore neither condition will result in successful ignition.]]></description>
      <pubDate>Mon, 27 Apr 2026 16:17:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663666</guid>
    </item>
    <item>
      <title>Integration of Blue and Green Hydrogen Supply Chains for Road Mobility: Utilization of Byproduct Oxygen for Efficient Operation Through Optimization</title>
      <link>https://trid.trb.org/View/2683810</link>
      <description><![CDATA[Hydrogen is a key energy carrier in the transition to a sustainable, low-carbon future. Among hydrogen production methods, blue and green hydrogen are prominent, derived from non-renewable and renewable sources, respectively. This study explores the potential integration of these two supply chains to support hydrogen use in road mobility. First, a literature review is conducted to understand the characteristics of each supply chain. Then, a mono-objective, static and deterministic Mixed-Integer Linear Program (MILP) designs a supply chain network based on two cases to fulfill future road mobility demand in Qatar, although the model itself can be applied outside Qatar as well. In the first case, only blue hydrogen can be produced, and Auto-Thermal Reforming (ATR) pathway is selected. In the second case, the model can incorporate both green and blue pathways, with the green pathway chosen. Through literature review, it was also highlighted that Air-Separation Units (ASUs) represent a major capital cost in ATR plants, whereas oxygen from electrolysis is typically vented. This opens the possibility of using this electrolytic by-product oxygen in ATR, suggesting that integrating blue and green hydrogen supply chains could reduce overall network costs which warrants further study.]]></description>
      <pubDate>Mon, 27 Apr 2026 15:01:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2683810</guid>
    </item>
    <item>
      <title>Developing Accessibility and Connectivity on Gili Iyang Island, Indonesia</title>
      <link>https://trid.trb.org/View/2665632</link>
      <description><![CDATA[Gili Iyang island is a tourist destination recognized for developing a health-focused industry to attract visitors. Transportation and infrastructure challenges in the tourism sector are important areas to examine for the industry's progress. Therefore, this research aimed to determine the right strategy to promote health tourism in Sumenep, East Java, Indonesia. Data analysis included a comprehensive examination using qualitative descriptive methods, Importance-Performance Analysis (IPA), and a connectivity index. The results showed that the optimal strategy for Gili Iyang Island is to focus on increasing accessibility, ensuring affordable travel costs, and maintaining convenience. Aspects of accessibility to improve include road networks and modes of transportation. Furthermore, the connectivity aspects that must be maintained are road access, seaport, and ferry port. The health tourism development strategy was implemented with a participatory approach and media technology convergence. The main originality of the research includes health tourism, natural conditions, and infrastructure. Additionally, the research recommends that tourists explore natural destinations characterized by unpolluted air and high oxygen levels.]]></description>
      <pubDate>Thu, 19 Feb 2026 13:21:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2665632</guid>
    </item>
    <item>
      <title>A biometric-based intelligent monitoring system for early detection and prevention of driver fatigue and distraction</title>
      <link>https://trid.trb.org/View/2620533</link>
      <description><![CDATA[Computer information technology is increasingly used in safety applications. Driver health and conduct are crucial as they significantly impact road safety. Drivers, especially those with chronic conditions, face heightened risks. A Driver Monitoring System (DMS) utilises sensors and algorithms to monitor behaviour and physiology in real-time to detect fatigue, distraction or impairment. The proposed system tracks blood pressure, oxygen levels and heart rate, alerting the driver or intervening when necessary. The aim of this paper is to suggest ways to consider certain factors that are crucial to ensure the safety of drivers. By implementing a system that keeps track of the driver's condition, a significant number of accidents can be avoided. There are many software packages available in today's industry that offer different driver monitoring devices.]]></description>
      <pubDate>Tue, 17 Feb 2026 13:12:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2620533</guid>
    </item>
    <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>Temperature-dependent performance trade-offs in PEMFCs: A mechanistic study and oxygen-enriched compensation strategy</title>
      <link>https://trid.trb.org/View/2640772</link>
      <description><![CDATA[Proton exchange membrane fuel cells (PEMFCs) operating at elevated temperatures (>100 °C) hold promise for simplified water-thermal management compared to conventional 60–85 °C systems. However, the complex interplay of activation polarization, oxygen partial pressure and mass transfer at high temperatures remains unresolved, limiting their practical deployment. Herein, we decode a temperature-dependent trade-off. It governs PEMFCs performance across a wide temperature range (60–100 °C) through operando polarization decomposition, limit current method and a validated multiphysics coupling model, revealing that while rising temperatures reduce the intrinsic total mass transfer resistance (R[subscript total]) and activation overpotential, these benefits are negated by oxygen partial pressure drop due to accelerated water vaporization-induced gas dilution. To address this bottleneck, we propose an oxygen-enriched air control strategy that dynamically adjusts cathode gas composition, achieving 36 % increase in peak power and 90 mV improvement in voltage (@1.6 A/cm²) at 100 °C. Quantification via game-theoretic analysis shows 67 % performance gain from oxygen compensation and 33 % from activation polarization and R[subscript total] mitigation. Moreover, there is no sign of accelerated durability degradation compared to air under oxygen-enriched air conditions. This work decouples temperature-dependent polarization mechanisms and provides a transformative pathway for next-generation high-temperature PEMFCs systems.]]></description>
      <pubDate>Mon, 22 Dec 2025 10:59:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2640772</guid>
    </item>
    <item>
      <title>3D CFD Analysis of Flow and Thermal Dynamics of PEM Water Electrolyzer</title>
      <link>https://trid.trb.org/View/2623813</link>
      <description><![CDATA[The proton exchange membrane (PEM) water electrolyzer is an emerging technology to produce green hydrogen due to its compactness and producing high purity hydrogen. This study presents a numerical investigation on multiphase flow dynamics and heat transfer within the anode flow field of a PEM water electrolyzer. Two different channel configurations, i.e., rectangular, semi-circular are considered having same cross-sectional area while keeping the porous transport layer (PTL) thickness constant (which is within the commercially available ranges). Simulations are conducted for various oxygen generation rates and heat fluxes (corresponding to different current densities) and different inlet water flow rates. The effects of channel configurations on pressure drop, flow uniformity, and temperature distribution are illustrated pictorially and graphically. The impact of water flow rates and oxygen generation rates on phase distribution, pressure drop, and temperature profiles, particularly focusing on hot spot regions and oxygen starvation regions are investigated thoroughly. Detailed oxygen concentration distributions and temperature contours at various locations are depicted for different geometrical and operating condition that are crucial for effective functioning of the membrane. This study brings out the importance of channel configurations, operating current densities on PEM water electrolyzer performance. The insights gained are expected to guide the design of new anode plates, aiming to mitigate issues such as hot spots and oxygen starvation, ultimately leading to improved efficiency and reliability of PEM water electrolyzer in sustainable hydrogen production.]]></description>
      <pubDate>Thu, 13 Nov 2025 16:26:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/2623813</guid>
    </item>
    <item>
      <title>Experimental and Kinetic Study of Methane Blending on The Laminar Combustion and Emission Characteristics of Ammonia Under Various Oxygen Contents at High Temperature and Pressure</title>
      <link>https://trid.trb.org/View/2623932</link>
      <description><![CDATA[As a carbon-free fuel, ammonia is one of the alternatives to traditional fossil fuels, but its combustion characteristics are poor, and it is usually optimized by blending methane and increasing oxygen content. However, there are few relevant studies under different conditions. In this study, the laminar burning velocities (LBV) and flame instability of NH3/CH4/O2/N2 mixture at high initial temperature (T), high initial pressure (p), various oxygen contents (Ω) and methane energy ratios (α) are analyzed using a constant volume combustion chamber (CVCC). Through numerical simulation, how various oxygen contents and methane energy ratios affect the combustion characteristics of NH3/CH4/O2/N2 mixture and NO emission is analyzed. The results show that LBV is positively correlated with T, α and Ω, and negatively correlated with p. Markstein length (Lb) does not change significantly with T, but increases with α and decreases with p and Ω. Both oxygen enrichment and methane blending significantly increase the hydrodynamic instability of the flame and decrease the buoyancy instability of the flame. Oxygen enrichment and methane blending have little effect on the thermal diffusion instability of the flame. Oxygen enrichment and methane blending are effective in increasing the generation of NHi, O, H, OH, and other radicals and the chemical reaction rate. The main factor of oxygen enrichment and methane blending to increase LBV is the thermal effect, but it also leads to the increase of NO, which is mainly thermal NO. The reaction path and sensitivity analysis of NO show that HNO + H <=> NO + H2, N + NO <=> N2 + O play an important role in the production and consumption of NO, respectively. With the change of Ω and α, the concentration of NO increases and the time of NO production decreases.]]></description>
      <pubDate>Thu, 13 Nov 2025 16:12:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2623932</guid>
    </item>
    <item>
      <title>Low Flow / Optimized Flow Oxygen Systems for Passengers – (OFOS) - A Physiologic Inquiry into Emergency Supplemental Oxygen Supply Needs and Procedures [supporting dataset]</title>
      <link>https://trid.trb.org/View/2606754</link>
      <description><![CDATA[The Optimized Flow Oxygen Systems (OFOS) study evaluated blood oxygen saturation level (SpO₂) values and oxygen flow rates via Federal Aviation Administration (FAA)-approved phase-dilution passenger oxygen masks at simulated cabin altitudes between 12K’ and 45K’. Results favor establishment of performance-based, physiological criteria (e.g., range of SpO₂ values) that can be used as a minimum performance standard for the minimum mass flow of supplemental oxygen to a passenger mask for adequate hypoxia protection. OFOS data demonstrate significantly higher stable human blood oxygenation levels are maintained through use of a phase-dilution passenger oxygen mask than is required by 14 CFR 25.1443(c)(2) regulation, and a brief transit as a passenger to 45k’ while breathing oxygen from a PAX mask is tolerable (SpO₂ does not fall below 14 CFR 25.1443 (c)(2) regulation guidelines). OFOS data support, (1) 14 CFR 25.1443(c)(2) regulation modification in favor of SpO₂ focus, (2) use of less oxygen as a result of SpO₂ focused findings, (3) fuel/cost-savings, (4) less CO₂ emissions, and (5) evidence that passengers are adequately protected under circumstances of a gradual decompression to 45K’ pressure-altitude if exposed for less than 1 minute (validation of FAA Memorandum ANM-03-112-16 (24 MAR 2006)). As a result of this evidence, if more aircraft are type-certified for 45K’ flight, then overall safety will improve as a result of decongested NAS national airspace.]]></description>
      <pubDate>Thu, 23 Oct 2025 09:23:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2606754</guid>
    </item>
    <item>
      <title>Low Flow / Optimized Flow Oxygen Systems for Passengers – (OFOS) - A Physiologic Inquiry into Emergency Supplemental Oxygen Supply Needs and Procedures: Data Management Plan</title>
      <link>https://trid.trb.org/View/2606753</link>
      <description><![CDATA[The Optimized Flow Oxygen Systems (OFOS) study evaluated blood oxygen saturation level (SpO₂) values and oxygen flow rates via Federal Aviation Administration (FAA)-approved phase-dilution passenger oxygen masks at simulated cabin altitudes between 12K’ and 45K’. Results favor establishment of performance-based, physiological criteria (e.g., range of SpO₂ values) that can be used as a minimum performance standard for the minimum mass flow of supplemental oxygen to a passenger mask for adequate hypoxia protection. OFOS data demonstrate significantly higher stable human blood oxygenation levels are maintained through use of a phase-dilution passenger oxygen mask than is required by 14 CFR 25.1443(c)(2) regulation, and a brief transit as a passenger to 45k’ while breathing oxygen from a PAX mask is tolerable (SpO₂ does not fall below 14 CFR 25.1443 (c)(2) regulation guidelines). OFOS data support, (1) 14 CFR 25.1443(c)(2) regulation modification in favor of SpO₂ focus, (2) use of less oxygen as a result of SpO₂ focused findings, (3) fuel/cost-savings, (4) less CO₂ emissions, and (5) evidence that passengers are adequately protected under circumstances of a gradual decompression to 45K’ pressure-altitude if exposed for less than 1 minute (validation of FAA Memorandum ANM-03-112-16 (24 MAR 2006)). As a result of this evidence, if more aircraft are type-certified for 45K’ flight, then overall safety will improve as a result of decongested NAS national airspace.]]></description>
      <pubDate>Thu, 23 Oct 2025 09:23:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2606753</guid>
    </item>
    <item>
      <title>Low Flow / Optimized Flow Oxygen Systems for Passengers – (OFOS) - A Physiologic Inquiry into Emergency Supplemental Oxygen Supply Needs and Procedures</title>
      <link>https://trid.trb.org/View/2606752</link>
      <description><![CDATA[The Optimized Flow Oxygen Systems (OFOS) study evaluated blood oxygen saturation level (SpO₂) values and oxygen flow rates via Federal Aviation Administration (FAA)-approved phase-dilution passenger oxygen masks at simulated cabin altitudes between 12K’ and 45K’. Results favor establishment of performance-based, physiological criteria (e.g., range of SpO₂ values) that can be used as a minimum performance standard for the minimum mass flow of supplemental oxygen to a passenger mask for adequate hypoxia protection. OFOS data demonstrate significantly higher stable human blood oxygenation levels are maintained through use of a phase-dilution passenger oxygen mask than is required by 14 CFR 25.1443(c)(2) regulation, and a brief transit as a passenger to 45k’ while breathing oxygen from a PAX mask is tolerable (SpO₂ does not fall below 14 CFR 25.1443 (c)(2) regulation guidelines). OFOS data support, (1) 14 CFR 25.1443(c)(2) regulation modification in favor of SpO₂ focus, (2) use of less oxygen as a result of SpO₂ focused findings, (3) fuel/cost-savings, (4) less CO₂ emissions, and (5) evidence that passengers are adequately protected under circumstances of a gradual decompression to 45K’ pressure-altitude if exposed for less than 1 minute (validation of FAA Memorandum ANM-03-112-16 (24 MAR 2006)). As a result of this evidence, if more aircraft are type-certified for 45K’ flight, then overall safety will improve as a result of decongested NAS national airspace.]]></description>
      <pubDate>Thu, 23 Oct 2025 09:23:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2606752</guid>
    </item>
    <item>
      <title>Preparing an Oxygen-Dependent Passenger with a Surgically Altered Airway for Commercial Air Travel</title>
      <link>https://trid.trb.org/View/2611115</link>
      <description><![CDATA[Patients with lung disease can experience hypoxemia on commercial aircraft, which can usually be corrected with supplementary oxygen. In some cases, combinations of medical conditions and inability to deliver oxygen via simple methods can complicate assessment and delivery of flight oxygen. A 53-yr-old woman with multiple comorbidities planned a 4-h commercial flight. She has end-stage obstructive lung disease, hypercapnic respiratory failure requiring home oxygen, and previous laryngeal cancer treated by total laryngectomy, resulting in a neck stoma. She is prescribed 28% oxygen therapy via a stoma Venturi mask requiring 4 L · min-1. An airline-approved oxygen concentrator was necessary for flight, providing a maximum 3 L · min-1, so the authors could not assess flight oxygen without changing the delivery method, although a direct stoma oxygen connection or the use of heat and moisture exchangers (HME) had been contraindicated for normal use. Hypoxic challenge testing with various delivery methods showed that 3 L · min-1 was sufficient to maintain oxygenation safely with little risk of hypercapnia. Fitting a stoma HME with integral oxygen attachment caused accumulation of secretions and minor desaturation, although the patient could clear them spontaneously. Ultimately HME use was approved for flight only, although other methods were successfully evaluated.  Patients with respiratory conditions are often dissuaded from flying by healthcare professionals, especially in complex cases where guidelines do not address all combinations of medical conditions. With tailored assessment and advice, surgically altered airway anatomy should not preclude commercial air travel, even if supplementary oxygen is required.]]></description>
      <pubDate>Mon, 20 Oct 2025 13:38:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2611115</guid>
    </item>
  </channel>
</rss>