<?xml version="1.0" encoding="utf-8"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>TRB Publications Index</title><link>http://pubsindex.trb.org/</link><atom:link href="http://pubsindex.trb.org/common/TRIS Suite/feeds/rss.aspx?tc=NN%3ARbesjv%2A" rel="self" type="application/rss+xml" /><description></description><language>en-us</language><copyright>Copyright © 2015. 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>TRB Publications Index</title><url>http://pubsindex.trb.org/Images/PageHeader-wTitle.png</url><link>http://pubsindex.trb.org/</link></image><item><title>Use of Low-Activity Nuclear Density Gauge in Iron Oxide-Rich Soils</title><link>http://pubsindex.trb.org/view/1919102</link><description><![CDATA[Nuclear density gauges (NDG) have been widely used for field compaction control. However, their shortcomings include the burden of licensing with nuclear regulatory agencies, gauge maintenance, storage and transportation restrictions, requirement to wear dosimeters, and radiation safety training. A recently developed low-activity NDG (LANDG) alternative utilizes a low-strength gamma ray source to measure soil density that is Nuclear Regulatory Commission exempt in the U.S.A. and its territories. An accompanying non-nuclear moisture probe yields the moisture content by measuring the dielectric constant of the soil. This study aims to compare the LANDG results with those of the NDG in two common soil types on the island of Oahu, Hawaii: volcanic soils and coralline soils. Coralline soils are partially broken down remains of coral comprised primarily of calcium carbonate. Volcanic soils are basalt derivatives rich in iron oxide and the question arises as to whether the iron oxide will affect the dielectric value resulting in erroneous moisture content measurements. This research shows that the LANDG and NDG measurements of total unit weight are in good agreement for both soils. The moisture content measurements from the LANDG’s accompanying moisture probe are in good agreement with those of the NDG in coralline soils but are less satisfactory in volcanic soils. A plausible explanation is offered. Moisture offsets may be applied to the moisture probe’s measurements to reduce scatter and increase accuracy. Instances of when this is required are suggested.]]></description><pubDate>Wed, 23 Feb 2022 16:12:20 GMT</pubDate><guid>http://pubsindex.trb.org/view/1919102</guid></item><item><title>Developing Scenarios to Explore Impacts and Weaknesses in Aviation Response Exercises for Volcanic Ash Eruptions</title><link>http://pubsindex.trb.org/view/1495529</link><description><![CDATA[Ash from volcanic eruptions can severely interrupt air traffic, as the eruption of Eyjafjallajökull volcano in 2010 (hereafter E2010) impressively demonstrated. While the event had an unprecedented impact on aviation, especially in Europe, some research suggests that similar volcanic events might occur at shorter intervals in the future. This study developed two volcanic ash scenarios using Icelandic volcanoes to demonstrate the potential scale of extreme, yet possible event in terms of duration and intensity. This is done to investigate responses either during a long period of continuous risk assessment and maintenance or when facing a large-scale severe interruption of air traffic, while under current regulations. The NAME model of ash dispersion, used by the London Volcanic Ash Advisory Centre, was used to simulate the ash distribution in the scenarios. The model scenarios used historic data of ash volumes and the weather patterns prevailing in the E2010 event. The scenarios were presented to aviation experts to help create a picture of the current resilience of the aviation sector and identify opportunities for improvement in the current risk management. The research demonstrates that under both scenarios the impact on air traffic would be significant. Although uncertainties are too large to perform a detailed economic risk assessment, the financial consequences in both scenarios were expected to be in the order of billions of Euros. Furthermore, the scenarios identified weaknesses in current response exercises to volcanic events suggesting they need to work with more extreme scenarios and at some point test long duration.]]></description><pubDate>Tue, 27 Mar 2018 11:15:19 GMT</pubDate><guid>http://pubsindex.trb.org/view/1495529</guid></item><item><title>Cooperation Between Science and Aviation-Sector Service Providers in Europe for Risk Management of Volcanic Ash</title><link>http://pubsindex.trb.org/view/1438826</link><description><![CDATA[The eruption of Eyjafjallajökull in April–May 2010 (hereafter E2010) revealed the fragility of air traffic in the case of an ash-producing volcanic eruption. This study examines developments since E2010 of cooperation between science and aviation-sector service providers toward efforts for improved resilience against a new volcanic eruption. The research builds on literature and interviews with representatives from research and regulatory institutes, air traffic managers, aircraft operators, and engine manufacturers across Europe. The article describes how scientific advice was requested to revise the regulatory precautionary approach and reopen airspace during E2010. The paper depicts the increased effort of scientific advancement in the understanding of ash characterization, modeling of the volcanic ash plume, and atmospheric environment. Furthermore, cross-disciplinary workshops and the memorandum of understanding between Icelandic and British institutions are examined to document increased cooperation between scientists and aviation-sector service providers to provide support to decision makers. However, the science needed for improved risk management is complex and depends on the effects of volcanic ash on jet engines. The concentration levels decided on over the course of a few days in 2010 have not been revised, and the aviation industry does not seem to prioritize research into these issues. A dialogue is needed between science, governance, and engine manufacturers, as well as more collective research funding to test jet engines to improve informed decision making, rather than leaving such research only to the manufacturers and internal political agendas.]]></description><pubDate>Tue, 17 Jan 2017 09:35:56 GMT</pubDate><guid>http://pubsindex.trb.org/view/1438826</guid></item><item><title>Policy Recommendations for Enhanced Resilience of Aviation due to Extreme Volcanic Ash Eruptions</title><link>http://pubsindex.trb.org/view/1438813</link><description><![CDATA[This study researches progress after the Eyjafjallajökull volcanic eruption in 2010, as significant regulatory changes have been introduced to improve European and North Atlantic aviation risk management with regards to volcanic ash. In the study, stakeholders were invited to a participatory workshop to deal with extreme but realistic volcanic eruption scenarios and to discuss obstacles in the general management of aviation during volcanic ash eruptions as well as under extreme eruption scenarios. This paper presents recommendations developed from the workshop. A more comprehensive long-term contingency plan that includes alternative transport if aircraft are grounded is important to strengthen society’s resilience. Response exercises need to be more challenging than presently to drive stakeholders out of their comfort zone. Staff availability during long duration events needs improvement, e.g., with staff exchange between related agencies. It is recommended that staff be trained for accelerated demands and restructured tasks during a crisis that can last for months. A single point of information for stakeholders could help manage and reduce confusion due to large amounts of information from scattered sources. Added public awareness of events in progress is recommended. Communication products, such as maps, must be better aligned with end-user needs, and a way to represent uncertainty of data needs to be researched. Funding for research on the impact of ash on jet engines is needed since lack of knowledge there limits the benefits of advances in ash forecasting. The now varying Self Risk Assessment regulation need to be coordinated across nations.]]></description><pubDate>Tue, 17 Jan 2017 09:35:56 GMT</pubDate><guid>http://pubsindex.trb.org/view/1438813</guid></item><item><title>Impact of Mt. Baegdu Explosion to South Korea's Air Traffic Flow</title><link>http://pubsindex.trb.org/view/1337419</link><description><![CDATA[There has been growing interest on the impact of volcano ash regarding aviation safety and air travel and economics, especially after the eruption of Eyjafjallajokull in Iceland. The effects of the crisis extend to nearby countries and influences the air traffic and air transport industry, as well as their own air traffic and air transport industry. There is an active volcano in North Korea called Mount Baegdu that has become the center of interest for many South Koreans. This research focuses on the hypothetical case of the possible eruption of Mount Baegdu and the assessment of the level of disruption to South Korea. The focus of the analysis is on the 8 en-routes which are connected with major airports in South Korea. This study analyzes the effects of volcanic ash to air traffic flow at national and worldwide levels.]]></description><pubDate>Fri, 16 Jan 2015 08:28:49 GMT</pubDate><guid>http://pubsindex.trb.org/view/1337419</guid></item><item><title>Air Traffic Management in Volcanic Ash Events in Europe: A Year After Eyjafjallajökull Eruption</title><link>http://pubsindex.trb.org/view/1130074</link><description><![CDATA[The Eyjafjallajökull eruption in 2010 caused a major impact on aviation and spurred key players: the aviation regulators, aviation experts and political bodies into action. Lessons learned were used to build or improve the crisis management for operations in the volcanic ash episodes.  Impact of Eyjafjallajökull eruption on European air traffic management system brought several issues forward. One of them is: “information exchange improvement regarding the volcanic ash alerts, messages and other related communication”. Here, the authors will focus on how this issue was addressed in Europe during the past year, and on intermediate results of applied actions, through the analysis of the latest Volcanic Ash Exercise (VOLCEX) 11/01 and the eruption of Grímsvötn in May 2011. The exercise conducted in April 2011 focused on testing the effectiveness of new processes and new information tools, and was completed just a month before the eruption of Grímsvötn volcano.  The post-event analysis shows that the new processes and information tools enabled airlines, National Supervisory Authorities (NSAs) and Air Navigation Service Providers to better manage flight operations. Although the Grímsvötn eruption was one of the largest in Iceland in the last hundred years, the impact on aviation was much lower than in 2010. The authors will provide rationale for it. Some open issues remain: harmonizing the process of managing volcanic ash episodes in Europe, providing a guidance material for airlines on performing safety risk assessment (SRA) and assisting NSAs in overseeing submitted SRAs, mutual recognition of accepted SRAs by States and resolving the information overload during volcanic ash events.]]></description><pubDate>Fri, 23 Mar 2012 08:44:41 GMT</pubDate><guid>http://pubsindex.trb.org/view/1130074</guid></item><item><title>High-Speed Rail and Air Transportation: Lessons Learned from 2010 Eyjafjallajokull Volcanic Eruptions</title><link>http://pubsindex.trb.org/view/1092344</link><description><![CDATA[Seismic activity of the Eyjafjallajökull volcano started at the end of 2009 and gradually increased in intensity. In April 2010, airspace all over Europe was closed—which was unprecedented—due to the presence of volcanic ash in the upper atmosphere from the eruption of this Icelandic volcano. This air traffic disruption took place in response to concerns that ash ejected by the volcano would damage aircraft engines. The International Air Transport Association (IATA) estimated that the airline industry worldwide lost 148 million euros a day during the disruption. The closure of the airspace left five million travelers stranded around the world.   This paper firstly analyses the main effects generated by the volcano ash cloud on air transportation and, as a consequence, on the European transport system. Based on the study of the air companies and the stranded passengers behaviour during the crisis, an integral use of the European high-speed rail network is suggested as one of the best ways to make the transport system more reliable in case of emergency events. Secondly, the evolution of the relationship between airplane operators and high-speed rail administrations is studied in order to clarify the concepts of modal competence, cooperation and integration. As further eruptions from the same volcano are highly likely, the present layout and interoperability of the European high-speed network are discussed. Finally, some recommendations and proposals are suggested to minimize the effects of future air traffic disruptions.]]></description><pubDate>Wed, 18 May 2011 11:43:42 GMT</pubDate><guid>http://pubsindex.trb.org/view/1092344</guid></item><item><title>Impacts and Responses of Icelandic Aviation to the 2010 Eyjafjallajökull Volcanic Eruption: Case Study</title><link>http://pubsindex.trb.org/view/1091397</link><description><![CDATA[Despite volcanic eruptions in earlier times, the eruption of Iceland’s Eyjafjallajökull in April and May 2010 served as a climactic point in aviation history. Stakeholders in the air traffic industry were forced to reevaluate policies, safety standards, and guidelines and to seek new methods for data collection. The geographic location of Iceland in the Northern Atlantic air traffic region places it in a critical location. Volcanic eruptions there can radically affect the European and North Atlantic air traffic. The sequence of events is described, and the impacts from an Icelandic perspective are highlighted. Interviews with key authorities in the Icelandic aviation community revealed important issues that must be addressed. They relate specifically to updating the notice-to-airmen messaging system, enhancing the ash-monitoring and -forecasting system, and developing policies that provide structure for all stakeholders to harmonize their decisions and actions.]]></description><pubDate>Fri, 22 Apr 2011 11:04:28 GMT</pubDate><guid>http://pubsindex.trb.org/view/1091397</guid></item><item><title>Eruption of Eyjafjallajökull in Iceland: Experience of European Air Traffic Management</title><link>http://pubsindex.trb.org/view/1092866</link><description><![CDATA[The ash cloud from the Eyjafjallajökull volcano in Iceland caused a significant impact on aviation in April and May 2010. In just the period between April 14 and 21, more than 100,000 flights were cancelled, with more than $1.7 billion in lost revenues for airlines and more than 10 million stranded passengers. The magnitude of the impact was caused by the extent of the ash cloud coupled with the duration of the event and the consequent volcanic ash procedures in effect. This event provided significant insight into the handling of the volcanic ash crisis and stirred aviation regulators and other aviation organizations all over the world into action. The unfolding of events is presented; an overview of the lessons learned—such as the need for determination of hazardous ash concentration levels, improvement of forecast validation, and amelioration of information exchange—is given.]]></description><pubDate>Mon, 18 Apr 2011 12:24:43 GMT</pubDate><guid>http://pubsindex.trb.org/view/1092866</guid></item><item><title>HIGHWAY CONSTRUCTION PROBLEMS INVOLVING PLASTIC VOLCANIC ASH</title><link>http://pubsindex.trb.org/view/97102</link><description><![CDATA[ALONG THE EASTERN SHORES OF THE ISLAND OF HAWAII ARE SOILS DERIVED BY WEATHERING OF VOLCANIC ASH UNDER CONDITIONS OF CONTINUOUS MOISTURE. THIS HAS RESULTED IN A VERY PLASTIC TYPE OF SOIL WITH NATURAL MOISTURE CONTENT GENERALLY CLOSE TO 200 PERCENT. THE CONTAINED MOISTURE IS NOT FREE WATER AND HENCE CANNOT BE DRAINED. DUE TO THE ALMOST CONTINUOUS RAINFALL, THE DEEPER LAYERS MAINTAIN THEIR HIGH MOISTURE CONTENT. THE SURFACE LAYERS, MEASURING 6 TO 18 IN. THICK, ARE SUBJECT TO PARTIAL DRYING. DRYING EFFECTS AN IRREVERSIBLE CHANGE IN THE SOIL FROM PLASTIC TO RELATIVELY NON-PLASTIC. THUS PASSENGER CARS AND LIGHT TRUCKS CAN TRAVEL OVER THE TOPSOIL. ON THE OTHER HAND, THE UNDER SOIL, DUE TO ITS HIGH PLASTICITY, WILL NOT SUPPORT RUBBER-TIRED TRAFFIC. EQUIPMENT WITH CATERPILLAR TREAD, HOWEVER, CAN BE USED SUCCESSFULLY WITHIN CERTAIN LIMITATIONS. THESE LIMITATIONS STEM FROM THE FACT THAT THE UNDERSOIL IS THIXOTROPIC, SO ANY UNDUE WORKING OR MANIPULATION OF THE SOIL CAUSES IT TO LOSE ALL STABILITY WITH RESULTANT BOGGING DOWN OF EQUIPMENT AND SLIDING OF EMBANKMENT SLOPES. EXCAVATION CAN BE HANDLED EXPEDITIOUSLY BY USING EQUIPMENT SUCH AS A DRAGLINE, TAKING THE MATERIAL OUT IN ONE LIFT AS CLOSE AS POSSIBLE TO REQUIRED GRADE. THE FRESHLY EXPOSED UNDERSOIL MUST BE QUICKLY COVERED WITH 18 IN. OF SELECT ROCKY MATERIAL TO FORM A TEMPORARY SURFACE (WHICH LATER BECOMES THE SUB-BASE) FOR TRUCKS HAULING AWAY THE EXCAVATED MATERIAL. CARRYALLS FITTED WITH ATHEE TRACKS HAVE ALSO PROVEN SUCCESSFUL UNDER CERTAIN CONDITIONS. EMBANKMENTS ARE BEST CONSTRUCTED IN ALTERNATE LAYERS OF 5 FT. OF ASH AND 18 IN. OF STABLE ROCKY MATERIAL. THE LATTER SERVES AS A TEMPORARY STABLE SURFACE OVER WHICH EQUIPMENT SUCH AS TRUCKS AND TRAC-FITTED CARRYALLS CAN BRING UP MATERIAL. COMPACTION IS DEPENDENT UPON CONSTRUCTION TRAFFIC ENTIRELY. THIS LAYER METHOD ACHIEVES SATISFACTORY COMPACTION WITHOUT DANGER OF TOO INTENSIVE WORKING OF THE MATERIAL. END-DUMP METHODS CAN BE USED FOR RELATIVELY LOW AND SHORT EMBANKMENTS. FOR LONG EMBANKMENTS AND FOR HEIGHTS OVER 15 FT., END-DUMP METHODS RESULT IN TOO INTENSIVE WORKING OF THE MATERIAL WITH CONSEQUENT DANGER OF SLIDES. /AUTHOR/]]></description><pubDate>Thu, 28 Apr 1994 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/97102</guid></item><item><title>DESICCATION OF SOILS DERIVED FROM VOLCANIC ASH</title><link>http://pubsindex.trb.org/view/74241</link><description><![CDATA[Five volcanic-ash-derived soils from the island of Hawaii were studied to determine the relation of changing moisture content to engineering behavior.  Two soils weathered on the leeward side of the island under relatively dry conditions; the other three developed on the windward side under high mean annual rainfalls.  The dry soils show little change on desiccation whereas the desiccation of the wet soils is accompanied by an irreversible hardening that causes drastic changes in the index properties.  Engineering behavior of the dry soils is similar to that of a sandy silt.  The wet soils behave as plastic clays but, when they are dried out, their engineering characteristics change to those of a sand. Mercury porosimetry tests reveal that, in wet soils, volume changes between field mositure content and the oven-dry state are about 150 percent.  The dry soils exhibit very small volumetric shrinkage.  Drying tests under controlled relative humidity provide data on drying rates and critical moisture contents.  The mineralogy of the soils was studied by using X-ray diffraction and fluorescence, differential thermal, and thermogravimetric analyses.  The predominant minerals are gibbsite, iron oxides, and allophane. Mineralogical studies indicate that irreversible hardening is accompanied by an increase in gibbsite content.  Mercury porosimetry results and mineralogical analysis indicate that a major portion of the shrinkage is due to contraction of the intermediate-size pores and that the extent of shrinkage is a function of allophane content. /Author/]]></description><pubDate>Sat, 19 Aug 1978 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/74241</guid></item><item><title>PERFORMANCE RATING FOR AGGREGATE-SURFACED ROADS</title><link>http://pubsindex.trb.org/view/105095</link><description><![CDATA[AGGREGATE-SURFACED ROADS, ESPECIALLY THOSE CONSTRUCTED WITH VOLCANIC CINDERS, HAVE PERFORMED WITH VARIABLE RESULTS. THE U.S. FOREST SERVICE, IN CONNECTION WITH FOREST DEVELOPMENT ROAD CONSTRUCTION, INITIATED A STUDY TO DETERMINE WHAT PARAMETERS INFLUENCED THE PERFORMANCE OF CINDERS WHEN USED AS A WEARING SURFACE. A ROAD-RATING SYSTEM, SIMILAR TO THE AASHO ROAD TEST METHODS, WAS DEVELOPED TO DETERMINE WHICH WERE "GOOD ROADS" AND WHICH WERE "POOR ROADS" BASED ON 0 TO 5 NUMERICAL RATING SCALE. FORTY-SEVEN ROADS IN FORESTS IN SOUTH-CENTRAL OREGON WERE RATED AND STATISTICALLY CORRELATED WITH MAINTENANCE, RUTTING, WATERING, SPEED, AND TRAFFIC VOLUME BY MEANS OF A MULTIPLE LINEAR REGRESSION PROGRAM. THE RESULTING REGRESSION EQUATION HAD A MULTIPLE CORRELATION COEFFICIENT OF 0.812, WITH RUTTING AND SPEED BEING THE MOST SIGNIFICANT VARIABLES. THE RESULTS ARE FELT TO APPLY TO ALL TYPES OF AGGREGATE-SURFACED ROADS, WITH THE RESULTANT NUMERICAL RATING REFERRED TO AS A PERFORMANCE INDEX. THE INFORMATION FROM THIS RATING SYSTEM WILL BE USED TO RECOMMEND SPECIFICATIONS FOR UNTREATED SURFACE-COURSE MATERIAL. /AUTHOR/]]></description><pubDate>Mon, 28 Sep 1970 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/105095</guid></item></channel></rss>