Robertson I.,Alstom |
Masson C.,Alstom |
Sedran T.,IFSTTAR |
Barresi F.,VCSA |
And 3 more authors.
Construction and Building Materials | Year: 2015
Abstract This paper is based on a development over the past 5 years in France which culminated in 2013 with the construction of a demonstration of this ballastless trackform on the French network north of Paris. In this paper, we summarise the history of this development, "New Ballastless Track" (NBT) through the conceptual design phases, the extensive laboratory testing, culminating in the construction of the demonstration track. Construction was completed in August 2013 and train operations started earlier this year. We complete our paper with our conclusions concerning the difference in life cycle costs between NBT and ballasted track. To that end, we confirm the conclusions of many previous studies over the past few years, while throwing some light on the parameters which will tend to accentuate the advantage of NBT. © 2014 Elsevier Ltd.
Trinh V.N.,ParisTech National School of Bridges and Roads |
Tang A.M.,ParisTech National School of Bridges and Roads |
Cui Y.-J.,ParisTech National School of Bridges and Roads |
Dupla J.-C.,ParisTech National School of Bridges and Roads |
And 5 more authors.
Soils and Foundations | Year: 2012
In the track substructure of ancient railways in France, a fouled ballast layer has often been created with time. The mechanical behaviour of this coarse soil was studied in the laboratory using a large-scale triaxial cell. The soil taken from the fouled ballast layer of an ancient railway was re-compacted to a dry density of 2.01 Mg/m3 at three water contents (4, 6, and 12%) corresponding to three values of the initial degree of saturation (32, 48, and 100% respectively). Both monotonic and cyclic triaxial tests were performed under constant water content conditions. The experimental results gave the following evidence of the significant effect of the water content on the soil mechanical behaviour: (i) the lower the compaction water content, the higher the shear strength; (ii) a permanent axial strain of 0.4% was found after a large number of cycles at a water content of 4%, while it was 1.4% at the higher water content of 6%. For the saturated soil specimen, failure was even observed after a limited number of cycles. Based on the results obtained, a constitutive model for permanent deformation was elaborated, that accounts for the stress level, the number of cycles and the soil water content. © 2012 The Japanese Geotechnical Society.
Vidaud M.,OXAND Inc |
Bernard O.,OXAND Inc |
Crouigneau S.,OXAND Inc |
Putallaz Y.,IMDM |
And 2 more authors.
WIT Transactions on the Built Environment | Year: 2012
This article presents three different ways of predicting investment needs to maintain and renew railway infrastructure. The 'Level 1' approach is based on financial ratios and does not take into account the infrastructure's history or maintenance strategies. This simplified approach can be used provided that the components age pyramid is uniform. The 'Level 2' approach considers the age pyramid's general impact without integrating budget constraints and possible specific optimization at the component level. This approach is useful and gives interesting rough estimates for macroscopic finance audits; it does not require an exhaustive knowledge of the owner's material assets. The advanced 'Level 3' approach enables planning of detailed investment needs on short, medium and long-term scales. It considers both physical and economic lifetimes for each component of the infrastructure as well as taking into account the budget constraints of the infrastructure's manager. It also allows the possibility of quantifying risks related to performance failure due to underinvestment. Using these different approaches, or cost models, with different European infrastructure managers enabled demonstration that investment needs and thus potential regulated returns (for regulated railway network management), strongly depend on infrastructure history and components age pyramid as well as physical and economic lifetimes. The article shows that management policy decisions and balance between renewal and maintenance, crucial in securing long-term network integrity (or 'substance') and in deciding on short-term investments, can be pre-modelled using advanced methods and tools to assess performance versus cost and risk over time. © 2012 WIT Press.
US energy giant ExxonMobil is facing an onslaught from environmentalists and some shareholders alleging it hid what it knew about the effects of fossil fuels on climate change. (AFP Photo/KAREN BLEIER) New York (AFP) - US energy giant ExxonMobil is facing an onslaught from environmentalists and some shareholders alleging it hid what it knew about the effects of fossil fuels on climate change. In an ironic twist: among the opponents is the Rockefeller Family Fund, built on the fortune amassed by John D. Rockefeller, founder of Standard Oil, which became Esso, then Exxon and then, in 1999, ExxonMobil. The RFF met last January, in secret, in Manhattan with environmental nongovernmental groups "to establish in the public's mind that Exxon is a corrupt institution that has pushed humanity (and all creation) towards climate chaos and grave harm," according to an internal document on the meeting seen by AFP. "We hosted a meeting with leading advocates to understand their thoughts on how to best respond to the outrageous conduct," Lee Wasserman, the director of RFF, told AFP. They adopted a strategy to attack ExxonMobil on legal grounds, by convinci ng authorities to launch investigations and by filing lawsuits. In other words, replicating the tactics used against the tobacco industry in the 1990s. "This is a conspiracy to deliberately misrepresent the company position and to tear down the company," Alan Jeffers, a spokesman for ExxonMobil, told AFP. According to a person close to the situation who requested anonymity, certain members of the Rockefeller family have privately expressed opposition to the campaign against ExxonMobil. Bill McKibben, founder of the NGO 350.org who participated in the January meeting, has pushed for investigations into whether ExxonMobil broke the law. "We want everyone we can think of to know it broke every kind of moral law," McKibben said in an email. The ecologist led the ultimately successful opposition against the Keystone XL pipeline, which would have brought Canadian oil sands production from Alberta to the US Gulf states. The ExxonMobil critics accuse the oil company of having, since 1977, research showing that fossil-fuel energy has a harmful impact on climate, but that it kept the information to itself. Denouncing the critics charges as "inaccurate" and a "conspiracy", ExxonMobil insists that it had acknowledged the risks of climate change as soon as it was possible, that is, in the 2000s. Accusing the Rockefeller organization of influencing the media and the authorities, the Texas firm has pledged to publicly defend its positions, although until now it has maintained a certain discretion about the subject. The change in attitude is due to the power of the Rockefellers, who not only have the colossal financial means to contest ExxonMobil on all battlegrounds, but also the influence of their powerful family name. The RFF has based its opposition on two separate investigations, by the InsideClimate News and the journalism school at Columbia University in New York, that found ExxonMobil knew in the 1970s that fossil fuels were a major source of climate change. InsideClimate, like the Columbia school, received financing from the Rockefellers. The RFF also criticizes ExxonMobil's support of think tanks "which helped create doubt about the profound risks associated with climate change." That includes the lobbying group the American Legislative Exchange Council, which is financed by companies including ExxonMobil, Jeffers acknowledges. Cynthia Bergman, an executive at the oil group, is a member of ALEC's advisory council. Since the probe revelations, a number of states have launched investigations into whether it lied about climate change. The state of New York, for example, has requested documents related to the allegations and a list of associations and NGOs financed by the company. While Jeffers says the company is cooperating with these investigations, ExxonMobil is fighting a legal battle over an investigation launched by the US Virgin Islands as the group of Caribbean islands faces the threat of rising water levels blamed on climate change. The activists and the RFF could score a first victory on May 25 if ExxonMobil shareholders approve a resolution requiring the company to disclose the impact of climate change on its business, a policy agreed at the climate summit in Paris last year. A dozen shareholders, including the huge California state pension fund CalPERS, French bank BNP Paribas and insurer AXA, are backing approval of the measure.
« Dahn team develops ethylene-carbonate-free electrolytes for better-performing high-voltage Li-ion cells | Main | New Flyer adds 2016 Cummins Westport ISL G Near Zero engine to Xcelsior bus lineup; debuting in LA » The Institute for Advanced Composites Manufacturing Innovation, IACMI, in partnership with DuPont Performance Materials, Fibrtec Inc. and Purdue University, has launched the first project selected with a dual focus on decreasing the cost of manufacture and increasing design flexibility for automotive composites. Advancements in both areas can open up new opportunities and become an enabler for large-scale deployment of composite parts. Multiple factors, including cost and design constraints, present barriers to the adoption of composites in high volume automotive applications. This new IACMI project will address both of these critical areas through a fundamentally different approach to the manufacturing of carbon fiber composites versus those currently in use today. The work will build on synergies of differentiated technologies, including novel materials and processes that allow flexible pre-pregs (Fiberflex) combined with Rapid Fabric Formation (RFF) technology to provide customizable fiber orientations via thermal bonding to significantly improve cycle time, cost, and waste. The final component will benefit from increased production speeds of the tow manufacturing process and the fabric forming process resulting in a lower cost of manufacture. The partners have estimated that use of emerging materials for impregnation and new approaches for tow coating and fabric formation will lower costs of high volume composites production by 20%. Composite parts made by this process have been shown to have low voids and good mechanical properties when consolidated by traditional techniques. The flexible fabric prepregs have also been shown to have good draping behavior in molding experiments. Researchers in the Purdue University Composites Manufacturing and Simulation Center will work with the team to model and validate drapability and part performance. High cycle time for production of continuous carbon fiber thermoplastic composites increases costs. The use of emerging materials for impregnation and new approaches for tow coating and fabric formation are expected to significantly lower production costs of high volume composites. The Institute for Advanced Composites Manufacturing Innovation (IACMI), managed by the Collaborative Composite Solutions Corporation (CCS), is a partnership of industry, universities, national laboratories, and federal, state and local governments working together to accelerate development and commercial deployment of advanced composites. CCS is a not-for-profit organization established by The University of Tennessee Research Foundation. The national institute is supported by a $70-million commitment from the US Department of Energy’s Advanced Manufacturing Office and more than $180 million committed from IACMI’s partners.