• Energy Research

ZnO nanowire networks featuring excellent charge transport and light scattering properties are grown in situ within TiO(2) films. The resultant TiO(2) /ZnO composites, used as photoanodes, remarkably enhance the overall conversion efficiency of dye-sensitized solar cells (DSSCs) by 26.9%, compared to that of benchmark TiO(2) films.

Experimental and analytical research is being carried out in an industrially oriented project dealing with on estimating and managing lifetime of critical structural components in energy industry. The research topics included systematic component lifetime management, lifetime of pressure bearing components, piping vibrations and integrity management, management of materials ageing, non-destructive inspection, water chemistry, oxide films and their role in service reliability and build-up of activity levels, stress corrosion cracking in Inconel welds, irradiation assisted stress corrosion cracking of core components, development of crack growth testing methods as well as the mechanisms of environmentally assisted cracking. The main results of the first project year are summarised in this report.

AbstractDespite the general recognition that fragmentation can reduce forest biomass through edge effects, a systematic review of the literature does not reveal a clear role of edges in modulating biomass loss. Additionally, the edge effects appear to be constrained by matrix type, suggesting that landscape composition has an influence on biomass stocks. The lack of empirical evidence of pervasive edge‐related biomass losses across tropical forests highlights the necessity for a general framework linking landscape structure with aboveground biomass. Here, we propose a conceptual model in which landscape composition and configuration mediate the magnitude of edge effects and seed‐flux among forest patches, which ultimately has an influence on biomass. Our model hypothesizes that a rapid reduction of biomass can occur below a threshold of forest cover loss. Just below this threshold, we predict that changes in landscape configuration can strongly influence the patch's isolation, thus enhancing biomass loss. Moreover, we expect a synergism between landscape composition and patch attributes, where matrix type mediates the effects of edges on species decline, particularly for shade‐tolerant species. To test our conceptual framework, we propose a sampling protocol where the effects of edges, forest amount, forest isolation, fragment size, and matrix type on biomass stocks can be assessed both collectively and individually. The proposed model unifies the combined effects of landscape and patch structure on biomass into a single framework, providing a new set of main drivers of biomass loss in human‐modified landscapes. We argue that carbon trading agendas (e.g., REDD+) and carbon‐conservation initiatives must go beyond the effects of forest loss and edges on biomass, considering the whole set of effects on biomass related to changes in landscape composition and configuration.

Abstract N is known to be the most limiting element for vegetation growth in temperate and boreal forests. The expected increases in global temperature are predicted to accelerate N mineralization, therefore incrementing N availability in the soil and affecting the soil C cycle as well. While there is an abundance of C data collected to fulfill the requirements for national GHG accounting, more limited information is available for soil N accumulation and storage in relation to forest categories and altitudinal gradients. The data collected by the second Italian National Forest Inventory, spanning a wide range of temperature and precipitation values (10° latitudinal range), represented a unique opportunity to calculate N content and C/N ratio of the different soil layers to a depth of 30 cm. Boosted Regression Tree (BRT) models were applied to investigate the main determinants of soil N distribution and C/N ratio. Forest category was shown to be the main explanatory factor of soil N variability in seven out of eight models, both for forest floor and mineral soil layers. Moreover latitude explained a larger share of variability than single climate variables. BRT models explained, on average, the 49% of the data variability, with the remaining fraction likely due to soil-related variables that were unaccounted for. Accurate estimations of N pools and their determinants in a climate change perspective are consequently required to predict the potential impact of their degradation on forest soil N pools.

AbstractThe reaction Cl + isobutene (i-C4H8) was reported by Suits et al. to proceed via, in addition to abstraction, an addition-elimination path following a roaming excursion of Cl; a near-zero translational energy release and an isotropic angular distribution observed at a small collision energy characterized this mechanism. We employed a new experimental method to further characterize this roaming mechanism through observation of the internal distribution of HCl (v, J) and their temporal behavior upon irradiation of a mixture of Cl2C2O2 and i-C4H8 in He or Ar buffer gas. With 1–3 Torr buffer gas added to approach the condition of small collision energy, the intensities of emission of HCl (v = 1, 2) and the HCl production rates increased significantly; Ar shows a more significant effect than He because Ar quenches Cl more efficiently to reduce the collisional energy and facilitate the roaming path. According to kinetic modeling, the rate of addition-elimination (roaming) increased from kE ≈ 2 × 105 s−1 when little buffer gas was present to ~1.9 × 106 s−1 when 2–3 Torr of Ar was added, and the branching ratio for formation of [HCl (v = 2)]/[HCl (v = 1)] increased from 0.02 ± 0.01 for abstraction to 0.06 ± 0.01 for roaming.

Recently reported studies considering nonlinearity in the effects of low-dose space radiation have assumed a nontargeted mechanism. To date, few analyses have been performed to assess whether a nontargeted term is supported by the available data. The Harderian gland data from Alpen et al. (published in 1993 and 1994), and Chang et al. (2016) provide the most diversity of ions and energies in a tumor induction model, including multiple high-energy and charge particles. These data can be used to investigate various nonlinearity assumptions against a linear model, including nontargeted effects in the low-dose region or cell sterilization at high doses. In this work, generalized linear models were used with the log complement link function to analyze the binomial data from the studies independently and combined. While there was some evidence of nonlinearity that was best described by a cell-sterilization model, the linear model was adequate to describe the data. The current data do not support the addition of a nontargeted effects term in any model. While adequate data are available in the low-dose region (<0.5 Gy) to support a nontargeted effects term if valid, additional data in the 1-2 Gy region are necessary to achieve power for cell-sterilization analysis validation. The current analysis demonstrates that the Harderian gland tumor data do not support the use of a nontargeted effects term in human cancer risk models.

The thermodynamic properties and the phase relations were evaluated and estimated for the Al-O-C, Al-Si-C, and Al-Fe-C systems which are important to understand the chemical behavior in an aluminum blast furnace. The mixing properties of binary liquid alloys, including metal-carbon systems, were represented by the Redlich-Kister equation. The properties of liquid Al−C and Si−C alloys were estimated so as to be consistent with their phase diagrams. The coefficients of Al−Fe and Fe−C liquids were evaluated from reported values for activity and enthalpy. The extrapolation to the higher order systems was made by Maggianu's method. The aluminum oxycarbide melt was represented by a subregular solution model. In the Al-O-C system, liquid alloy/oxycarbide melt equilibria were calculated and compared with earlier experimental results and estimates. Attempts were made to clarify the volatilization of aluminum oxycarbide melts, and also the carbidation of liquid aluminum alloys. An empirical correlation between the first terms of the Redlich-Kister equation for the enthalpies and the excess entropies was discussed.

Abstract A large part of government revenues in Russia comes from royalties and export taxes on crude oil, oil products, and gas. Recently, the Russian government has considered reducing export taxes on crude oil and oil products compensated by an increase in the royalty on crude oil. The objective of the paper is to analyse the economy-wide effects of this proposal. Moreover, a hypothetical replacement of export taxes and royalties with a pure rent tax is analysed. A static, single-country, multi-sector computable generation equilibrium (CGE) model is employed. The primary findings are as follows. A replacement of export taxes on crude oil and oil products with a royalty on crude oil provides substantial allocative efficiency gains, but this policy is not a superior one. Welfare could be substantially improved when the export taxes and royalty are replaced with a pure rent tax that can be implemented in the form of a cash-flow tax. On the negative side, reducing export taxes on crude oil and oil products results in a strong appreciation of the currency. As a result, domestic producers become less competitive in domestic markets, and there is a massive increase in import demand.