Hydrogen enhanced thermal fatigue of y-titanium aluminide

A study of hydrogen enhanced thermal fatigue cracking was carried out for a gamma-based Ti-48Al-2Cr alloy by cycling between room temperature and 750 or 900 °C. The results showed that hydrogen can severely attack the gamma alloy, with resulting lifetimes as low as three cycles, while no failures were observed in helium for test durations of over 4000 cycles. The severity of hydrogen attack strongly depends on the upper limit of the temperature cycled and the cleanliness of the hydrogen. Specifically, the large scatter of life times at 750 °C (ranging from 36 to more than 3000 cycles) have resulted from the competition between surface oxidation and hydrogen attack. The results suggest that an understanding of the combined actions of thermal cycling and hydrogen degradation is needed for assessing materials for high temperature applications in hydrogen

Biochar Derived from Cotton Fiber Feedstock: Characterization of Material and Potential for Adsorptive Capacity

Introduction Anthropogenic contaminants in surface waters have increased in complexity as the use of chemicals in all sectors of society has grown [1]. Water scarcity and quality issues will require robust, low-cost, and sustainable solutions. Biochars are particularly compelling as adsorptive solids because they repurpose wastes [2, 3] from other industries and are often carbon neutral, if not carbon negative. Cotton is the most common cellulosic fiber on the global fiber market, and as such, a significant contributor to municipal waste streams [4]. This research investigates the use of undyed, unbleached, 100% cotton muslin fabric as the fuel for making biochar to determine the feasibility of sourcing cotton fabric waste as biochar feedstock

Short term effects of moderate carbon prices on land use in the New Zealand emissions trading system: LURNZ-climate land use change simulations

The New Zealand Emissions Trading Scheme (NZ ETS) was introduced through the Climate Change Response Act in September 2008 and remains in force. The forestry sector has been directly affected by the NZ ETS since 1 January 2008 and stationary energy, liquid fuels and industrial emissions have been affected since 1 July 2010. When it is fully implemented in 2015 it will cover all sources and gases including agricultural emissions. Using the Land Use in Rural New Zealand model (LURNZ), we simulate rural land use changes that could be driven by the NZETS in order that we can explore their potential implications for emissions and removals (sequestration) and rural incomes and land values. This paper documents our simulation methods and presents short term (up to 2015) simulations for moderate prices ($25 New Zealand dollars per tonne of CO2-e) where our current modelling techniques are most robust.Crop Production/Industries, Environmental Economics and Policy, Industrial Organization, International Relations/Trade, Land Economics/Use, Livestock Production/Industries, Risk and Uncertainty,

Land use in rural New Zealand: spatial land use, land-use change, and model validation

Abstract Land is an important social and economic resource. Knowing the spatial distribution of land use and the expected location of future land-use change is important to inform decision makers. This paper documents and validates the baseline land-use maps and the algorithm for spatial land-use change incorporated in the Land Use in Rural New Zealand model (LURNZ). At the time of writing, LURNZ is the only national-level land-use model of New Zealand. While developed for New Zealand, the model provides an intuitive algorithm that would be straightforward to apply to different locations and at different spatial resolutions. LURNZ is based on a heuristic model of dynamic land-use optimisation with conversion costs. It allocates land-use changes to each pixel using a combination of pixel probabilities in a deterministic algorithm and calibration to national-level changes. We simulate out of sample and compare to observed data. As a result of the model construction, we underestimate the “churn” in land use. We demonstrate that the algorithm assigns changes in land use to pixels that are similar in quality to the pixels where land-use changes are observed to occur. We also show that there is a strong positive relationship between observed territorial-authority-level dairy changes and simulated changes in dairy area