The terrestrial carbon budget of South and Southeast Asia

This is the final version of the article. Available from IOP Publishing via the DOI in this record.Accomplishing the objective of the current climate policies will require establishing carbon budget and flux estimates in each region and county of the globe by comparing and reconciling multiple estimates including the observations and the results of top-down atmospheric carbon dioxide (CO2) inversions and bottom-up dynamic global vegetation models. With this in view, this study synthesizes the carbon source/sink due to net ecosystem productivity (NEP), land cover land use change (E LUC), fires and fossil burning (E FIRE) for the South Asia (SA), Southeast Asia (SEA) and South and Southeast Asia (SSEA = SA + SEA) and each country in these regions using the multiple top-down and bottom-up modeling results. The terrestrial net biome productivity (NBP = NEP - E LUC - E FIRE) calculated based on bottom-up models in combination with E FIRE based on GFED4s data show net carbon sinks of 217 ±147, 10 ±55, and 227 ±279 TgC yr-1 for SA, SEA, and SSEA. The top-down models estimated NBP net carbon sinks were 20 ±170, 4 ±90 and 24 ±180 TgC yr-1. In comparison, regional emissions from the combustion of fossil fuels were 495, 275, and 770 TgC yr-1, which are many times higher than the NBP sink estimates, suggesting that the contribution of the fossil fuel emissions to the carbon budget of SSEA results in a significant net carbon source during the 2000s. When considering both NBP and fossil fuel emissions for the individual countries within the regions, Bhutan and Laos were net carbon sinks and rest of the countries were net carbon source during the 2000s. The relative contributions of each of the fluxes (NBP, NEP, E LUC, and E FIRE, fossil fuel emissions) to a nation's net carbon flux varied greatly from country to country, suggesting a heterogeneous dominant carbon fluxes on the country-level throughout SSEA.This research was partly supported by the NASA Land Cover and Land Use Change Program (NNX14AD94G) and the US National Science Foundation (No. NSF-AGS-12-43071)

Moisture susceptibility of Nano-sized Hydrated Lime-modified foamed Warm Mix Asphalt mixes

Despite the obvious benefits of Warm Mix Asphalt (WMA) technologies are stealing the spotlight from classic Hot Mix Asphalt (HMA), there are concerns regarding moisture susceptibility of the mixes especially when it comes to the technologies that mainly depend on applying water (i.e., foaming). The primary objective of the research was to investigate the moisture susceptibility of foamed WMA mixes modified with Nanosized Hydrated Lime (NHL). Hydrated lime materials in this study included, NHL with particle sizes of 50-nm and 100-nm along with Regular-sized Hydrated Lime (RHL). The Tensile Strength Ratio (TSR) and dynamic modulus (|E*|) tests were employed to accomplish this objective. A secondary objective of this research was to assess the validity of the two utilized TSR and |E*| tests. The |E*| samples passed one and five freeze- Thaw cycling processes before each testing. The TSR and |E*| results revealed that foamed WMA mixes are more susceptible to moisture damage in comparison to the control mix. Also, the NHLmodified mixes performed much better than the RHL for both unconditioned and after multiple conditioning. The |E*| test seems more reasonable than the TSR test for moisture susceptibility testing. © 2014 Taylor & Francis Group, London

Ester Hydrogenation Catalyzed by CNN-Pincer Complexes of Ruthenium

Ruthenium complexes supported by two new CNN-pincer ligands were synthesized. Both were tested as catalysts for the hydrogenation of esters under mild conditions (105 °C, 6 bar H₂). A striking dependence on ligand structure was observed, as a dimethylamino-substituted ligand gave a nearly inactive catalyst, while a diethylamino-substituted variant gave up to 980 catalytic turnovers for the hydrogenation of benzyl benzoate. This system catalyzes the hydrogenation of various substrates including ethyl, benzyl, and hexyl esters, but is surprisingly unreactive toward methyl esters. Experiments demonstrate that base-catalyzed transesterification is rapid under the reaction conditions and that methyl esters are effectively hydrogenated when benzyl alcohol is added to the reaction mixture. The reverse reaction, dehydrogenation of primary alcohols to give esters, was tested as well; up to 920 catalytic turnovers were observed for the dehydrogenation of 1-hexanol to hexyl hexanoate

Ester Hydrogenation Catalyzed by CNN-Pincer Complexes of Ruthenium

Ruthenium complexes supported by two new CNN-pincer ligands were synthesized. Both were tested as catalysts for the hydrogenation of esters under mild conditions (105 °C, 6 bar H₂). A striking dependence on ligand structure was observed, as a dimethylamino-substituted ligand gave a nearly inactive catalyst, while a diethylamino-substituted variant gave up to 980 catalytic turnovers for the hydrogenation of benzyl benzoate. This system catalyzes the hydrogenation of various substrates including ethyl, benzyl, and hexyl esters, but is surprisingly unreactive toward methyl esters. Experiments demonstrate that base-catalyzed transesterification is rapid under the reaction conditions and that methyl esters are effectively hydrogenated when benzyl alcohol is added to the reaction mixture. The reverse reaction, dehydrogenation of primary alcohols to give esters, was tested as well; up to 920 catalytic turnovers were observed for the dehydrogenation of 1-hexanol to hexyl hexanoate