ALBERT

Description: New, commensurate members of the fluorite-related Bi 3 Nb 1− x Ta x O 7 family were synthesized and their crystal structures, microstructures, and microwave (MW) dielectric properties were characterized. The incorporation of Ta into the tetragonal Bi 3 Nb 1− x Ta x O 7 solid solution was found to gradually affect the density and the MW dielectric properties. The materials sintered at 870°C exhibited relative permittivities in the range k ′ = 86–72, Q  ×  f values from 793 to 1189 GHz and a positive temperature coefficient of resonant frequency from 88 to 12 ppm/K. The formation of the members of the fluorite-related solid solution along the Bi 3 Nb 1− x Ta x O 7 composition depends on a phase transition, and thus their properties are compared within the compositional range. The correlations between their MW dielectric properties, compositions, crystal structures, and processing parameters were discussed in detail. Optimization of MW properties can be achieved by utilizing the ability of the Bi 3 Nb 1− x Ta x O 7 solid solution that it undergoes a phase transformation from cubic to tetragonal structure which are both characterized by unique properties, under certain synthesis conditions.

Description: Transparent novel glass-ceramics containing Sr 2 YbF 7 :Er 3+ nanocrystals were successfully fabricated by melt-quenching technique. Their structural and up-conversion luminescent properties were systemically investigated by XRD, HRTEM, and a series of spectroscopy methods. The temperature-dependent up-conversion spectra prove that 2 H 11/2 and 4 S 3/2 levels of Er 3+ are thermally coupled energy levels (TCEL). Consequently, the 2 H 11/2 4 I 15/2 and 4 S 3/2 4 I 15/2 emissions of Er 3+ in Sr 2 YbF 7 :Er 3+ glass-ceramics can be used as optical thermometry based on fluorescence intensity ratio (FIR) technique. Combined with low phonon energy and high thermal stability, Er 3+ ions in Sr 2 YbF 7 glass-ceramics present broad operating temperature range (300–500 K), large energy gap of TCEL (786 cm −1 ) and high theoretical maximum value of relative sensitivity (62.14 × 10 −4  K −1 at 560 K), which suggests that Sr 2 YbF 7 :Er 3+ glass-ceramics may be excellent candidates for optical temperature sensors.

Description: Extraction of oil and natural gas (hydrocarbons) from shale is increasing rapidly in North America, with documented impacts to native species and ecosystems. With shale oil and gas resources on nearly every continent, this development is set to become a major driver of global land-use change. It is increasingly critical to quantify spatial habitat loss driven by this development to implement effective mitigation strategies and develop habitat offsets. Habitat selection is a fundamental ecological process, influencing both individual fitness and population-level distribution on the landscape. Examinations of habitat selection provide a natural means for understanding spatial impacts. We examined the impact of natural gas development on habitat selection patterns of mule deer on their winter range in Colorado. We fit resource selection functions in a Bayesian hierarchical framework, with habitat availability defined using a movement-based modeling approach. Energy development drove considerable alterations to deer habitat selection patterns, with the most substantial impacts manifested as avoidance of well pads with active drilling to a distance of at least 800 m. Deer displayed more nuanced responses to other infrastructure, avoiding pads with active production and roads to a greater degree during the day than night. In aggregate, these responses equate to alteration of behavior by human development in over 50% of the critical winter range in our study area during the day and over 25% at night. Compared to other regions, the topographic and vegetative diversity in the study area appear to provide refugia that allow deer to behaviorally mediate some of the impacts of development. This study, and the methods we employed, provides a template for quantifying spatial take by industrial activities in natural areas and the results offer guidance for policy makers, mangers, and industry when attempting to mitigate habitat loss due to energy development.

Description: Although long-distance migratory songbirds are widely believed to be at risk from warming temperature trends, species capable of attempting more than one brood in a breeding season could benefit from extended breeding seasons in warmer springs. To evaluate local and global factors affecting population dynamics of the black-throated blue warbler ( Setophaga caerulescens ), a double-brooded long-distance migrant, we used Pradel models to analyze 25 years of mark-recapture data collected in New Hampshire, USA. We assessed the effects of spring temperature (local weather) and the El Niño Southern Oscillation index (a global climate cycle), as well as predator abundance, insect biomass, and local conspecific density on population growth in the subsequent year. Local and global climatic conditions affected warbler populations in different ways. We found that warbler population growth was lower following El Niño years (which have been linked to poor survival in the wintering grounds and low fledging weights in the breeding grounds) than La Niña years. At a local scale, populations increased following years with warm springs and abundant late-season food, but were unaffected by spring temperature following years when food was scarce. These results indicate that the warming temperature trends might have a positive effect on recruitment and population growth of black-throated blue warblers if food abundance is sustained in breeding areas. In contrast, potential intensification of future El Niño events could negatively impact vital rates and populations of this species. This article is protected by copyright. All rights reserved.

Description: Ecotones are transition zones that form, in forests, where distinct forest types meet across a climatic gradient. In mountains, ecotones are compressed and act as potential harbingers of species shifts that accompany climate change. As the climate warms in New England, USA, high elevation boreal forests are expected to recede upslope, with northern hardwood species moving up behind. Yet recent empirical studies present conflicting findings on this dynamic, reporting both rapid upward ecotonal shifts and concurrent increases in boreal species within the region. These discrepancies may result from the limited spatial extent of observations. We developed a method to model and map the montane forest ecotone using Landsat imagery to observe change at scales not possible for plot-based studies, covering mountain peaks over 39,000 km 2 . Our results show that ecotones shifted downward or stayed stable on most mountains between 1991 and 2010, but also shifted upward in some cases (13-15% slopes). On average, upper ecotone boundaries moved down -1.5 m·yr −1 in the Green Mountains, VT, and -1.3 m·yr −1 in the White Mountains, NH. These changes agree with re-measured forest inventory data from Hubbard Brook Experimental Forest, NH and suggest that processes of boreal forest recovery from prior red spruce decline, or human landuse and disturbance, may swamp out any signal of climate-mediated migration in this ecosystem. This approach represents a powerful framework for evaluating similar ecotonal dynamics in other mountainous regions of the globe. This article is protected by copyright. All rights reserved.

Description: In order to adequately monitor biodiversity trends through time and their responses to natural or anthropogenic impacts, researchers require long time series that are often unavailable. This general lack of datasets that are several decades or longer makes establishing a background or baseline of diversity metrics difficult – especially when attempting to understand species composition changes against a backdrop of climate and ecological variability. Here we present an analysis of a community of juvenile nearshore fishes based on nearly 8 decades of highly standardized Norwegian survey records. Using multivariate statistical techniques, we: a) characterize the change in taxonomic community composition through time, b) determine whether there has been an increase in warm water affinity species relative to their cold water affinity counterparts, and c) characterize the temporal change in the species’ functional trait assemblage. Our results strongly indicate a shift towards a novel fish assemblage between the late 1990s and 2000s. The context of changes within the most recent two decades are in stark contrast to those during the 60s and 70s, but similar to those during the previous warm period during the 30s and 40s. This novel assemblage is tightly linked to the warming temperatures in the region portrayed by the increased presence of warm water species and a higher incidence of pelagic, planktivorous species. The results indicate a clear influence of ocean temperature on the region's juvenile fish community that points to climate mediated effects on the species assemblages of an important fish nursery area. This article is protected by copyright. All rights reserved.

Description: Accurate information on the interactions between water and silica is critical to the understanding of its properties including mechanical strength under stress and long-term chemical durability of silica and silicate glasses. In this study, interactions between water and nanoporous amorphous silica models were investigated using density functional theory (DFT) based ab initio molecular dynamics (AIMD) simulations which accurately describe bond breakage and formation as well as chemical reactions. AIMD simulations up to 30 ps were performed for systems containing water and nanoporous silica with a wide range of porosities (31%–67%). Partial removal of defects, such as two-membered rings, was observed during the AIMD runs whereas more reactive coordination defects were removed during the initial geometry optimization. The limited two-membered ring removal can be attributed to restricted water-defect movement or the increased stability of rings located on concave surfaces. Two-membered ring removal mechanisms included the formation of an overcoordinated silicon (Si 5 ) intermediate defect from the dynamic simulations. Si 5 defects continued to develop throughout the simulations, indicating a thermodynamic drive for two-membered ring removal which is kinetically limited. Changes in the electronic structures, such as atomic charges, and bond length-bond angle correlation functions were monitored during the hydroxylation process.

Description: Amorphous calcium polyphosphate (ACPP), an inorganic polymer ceramic, has shown promise as a drug delivery matrix following a repeat gelling protocol. This study described a simple method of preparing ACPP hydrogel in the presence of an excess volume of water. The increased water availability accelerates water molecule ingress and microstructural transformation of ACPP hydrogels. The impact of some experimental settings (soaking time, temperature, stirring, and ACPP particle size) on the physiochemical and rheological natures of ACPP hydrogel were investigated and from which possible hydrogel formation mechanisms were inferred. We believe that the formation of ACPP hydrogel is through the mechanisms of intermolecular ionic interaction and entanglement of polyphosphate chains. The potential application of ACPP hydrogel as a ceramic matrix for sustained drug release warrants further investigation.

Description: Melting gels are hybrid gels that have the ability to soften and flow at around 100°C for some combinations of mono- and di-substituted alkoxysiloxanes, where substitutions are either all aromatic or all aliphatic. In this study, melting gels were prepared using phenyltriethoxysilane (PhTES) and dimethyldiethoxysilane (DMDES), meaning both an aromatic and aliphatic substitution. Differential scanning calorimetry was performed to identify glass-transition temperatures, and thermal gravimetric analysis coupled with differential thermal analysis (TGA-DTA) was performed to measure weight loss. The glass-transition temperatures ( T g ) ranged from −61°C to +5.6°C, which are between the values in the methyl only system, where all T g values are less than 0°C, and those values in the phenyl only system, where T g values are greater than 0°C. The T g decreased with an increase in the DMDES fraction. Below 450°C, the gels lost little weight, but around 600°C there was a drop in weight. This temperature is lower than the temperature for gels prepared with only aromatic substitutions, but higher than that for gels prepared with only aliphatic substitutions. Final heat treatment was carried out at 150°C for the gel with 80%PhTES-20%DMDES (in mol%), and the consolidation temperature increased with increasing DMDES content to 205°C for the gel with 50%PhTES-50%DMDES. After this heat treatment, the melting gels no longer soften.

Description: Direct integration of nanostructures into macroscopic substrates is very important for their practical applications. In this work, we report a simple method that can be introduced for the Sn-catalyzed growth of alumina nanowires on ceramic substrates such as porous disk, monolith, and foam. Our study focuses on the role of the Sn catalysts in the formation mechanisms governing nanowire growth. Using the proposed approach, hair- or grass-like tufts of 20 nm diameter nanowires grow on the surface of the ~3 μm diameter Sn particles, in a tip growth mechanism. The nanowires of α-phased polycrystalline structure grow and are packed via a complex process involving batch-by-batch, branching, and amalgamation growth. The detailed observations reveal that the Sn catalyst is key to tailoring the growth patterns of the nanowires. In addition, cathodoluminescence studies highlight the potential optical applications of the alumina nanowires.

Description: Flash sintering is a nonlinear phenomenon characterized by a sharp increase in the conductivity of the sample and concomitant rapid densification under an electric field in low temperatures in a matter of seconds. Since it is a transient phenomenon, the power dissipation on the sample is not uniform during the process. Thus, a transient analysis is needed to estimate the temperature of the sample during flash sintering due to Joule heating. In this work, the Finite Element Method on a coupled electrothermal nonlinear analysis was used in order to obtain the specimen temperature of 8YSZ after 5 s of flashing. The results agree with the experimental data obtained by the flashing of dense samples and with previous literature.

Description: Temperature-dependent in-situ Raman spectroscopy is used to investigate the phase transformation of zinc metastannate (ZnSnO 3 ) to zinc orthostannate (Zn 2 SnO 4 ) induced upon annealing in the ambient. ZnSnO 3 microcubes (MCs) were synthesized at room temperature using a simple aqueous synthesis process, followed by characterization using electron microscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). Annealing of the ZnSnO 3 MCs was carried out up to 1000°C, while recording the Raman spectra in-situ at regular intervals. Phase transformation from metastannate to orthostannate was found to begin around 500°C with an activation energy of ~0.965 eV followed by the recrystallization into the inverse spinel orthostannate phase at ~750°C. Results from this study provide detailed understanding of the phase transformation behavior of perovskite ZnSnO 3 to inverse spinel Zn 2 SnO 4 upon thermal annealing.

Description: High Arctic landscapes are expansive and changing rapidly. However our understanding of their functional responses and potential to mitigate or enhance anthropogenic climate change is limited by few measurements. We collected eddy covariance measurements to quantify the net ecosystem exchange (NEE) of CO 2 with polar semidesert and meadow wetland landscapes at the highest-latitude location measured to date (82°N). We coupled these rare data with ground and satellite vegetation production measurements (Normalized Difference Vegetation Index; NDVI) to evaluate the effectiveness of upscaling local to regional NEE. During the growing season, the dry polar semidesert landscape was a near zero sink of atmospheric CO 2 (NEE: -0.3±13.5 g C m −2 ). A nearby meadow wetland accumulated over 300 times more carbon (NEE: -79.3±20.0 g C m −2 ) than the polar semidesert landscape, and was similar to meadow wetland NEE at much more southerly latitudes. Polar semidesert NEE was most influenced by moisture, with wetter surface soils resulting in greater soil respiration and CO 2 emissions. At the meadow wetland, soil heating enhanced plant growth, which in turn increased CO 2 uptake. Our upscaling assessment found that polar semidesert NDVI measured on site was low (mean: 0.120-0.157) and similar to satellite measurements (mean: 0.155-0.163). However, weak plant growth resulted in poor satellite NDVI-NEE relationships and created challenges for remotely-detecting changes in the cycling of carbon on the polar semidesert landscape. The meadow wetland appeared more suitable to assess plant production and NEE via remote-sensing, however high Arctic wetland extent is constrained by topography to small areas that may be difficult to resolve with large satellite pixels. We predict that until summer precipitation and humidity increases substantially, climate-related changes of dry high Arctic landscapes may be restricted by poor soil moisture retention, and therefore have some inertia against short-term changes in NEE. This article is protected by copyright. All rights reserved.

Description: Here, we demonstrate the relationship between glass network topological structure and the chemical state of embedded lanthanide ions. It is revealed that a more dispersed state of lanthanide ions is shown in more constrained 3D rigid network, which delivers valuable information toward homogeneous doping in glasses from the perspective of glass topological structure. The results are believed to be of great significances in the development of advanced optoelectronic devices like high-power laser, efficient fiber amplifier, smaller integrated photonic circuit, etc.

Description: The mechanofusion process, a dry particle coating route, has been successfully applied to coat micrometric SiC particles with submicrometric Ni filaments. In a first step, the mechanofusion parameters were optimized to form a continuous Ni coating onto SiC particles. In a second step, the Ni-coated SiC particles were sintered by hot isostatic pressing. The temperature and pressure cycles were determined to ensure a good densification of the material. Such a densification process leads to the formation of a δ-Ni 2 Si bilayer at the SiC/Ni interface; the inner δ-Ni 2 Si layer in contact with SiC being more rich in carbon than the one in contact with the matrix. From X-ray diffraction, wavelength-dispersive X-ray spectrometry and scanning electron microscopy characterizations, a mechanism is proposed to explain the microstructure of the end-product.

Description: Urban areas are expanding rapidly in tropical regions, with potential to alter ecosystem dynamics. In particular, exotic grasses and atmospheric nitrogen (N) deposition simultaneously affect urbanized landscapes, with unknown effects on properties like soil carbon (C) storage. We hypothesized that: (H1.) Soil nitrate (NO 3 - ) is elevated nearer to the urban core, reflecting N deposition gradients. (H2.) Exotic grasslands have drier soils, elevated NO 3 - , and decreased soil C relative to secondary forests, with higher N promoting decomposer activity. (H3.) Exotic grasslands have greater seasonality in soil NO 3 - versus secondary forests, due to higher sensitivity of grassland soil moisture to rainfall. We predicted that NO 3 - would be related to dissolved organic C (DOC) production via changes in decomposer activity. We measured six paired grassland/secondary-forest sites along a tropical urban-to-rural gradient during three dominant seasons (hurricane, dry, and early wet). We found that: (1.) Soil NO 3 - was generally elevated near the urban core, with particularly clear spatial trends for grasslands. (2.) Exotic grasslands had lower soil C than secondary forests, which was related to elevated decomposer enzyme activities and soil respiration. Unexpectedly, soil NO 3 - was negatively related to enzyme activities, and was higher in forests than grasslands. (3.) Grasslands had greater soil NO 3 - seasonality versus forests, but this was not strongly linked to shifts in soil moisture or DOC. Our results suggest that exotic grasses in tropical regions are likely to drastically reduce soil C storage, but that N deposition may have an opposite effect via suppression of enzyme activities. However, soil NO 3 - accumulation here was higher in urban forests than grasslands, potentially due to an interplay of aboveground N interception and soil processes. Net urban effects on C storage across tropical landscapes will likely vary depending on rates of N deposition, the mosaic of land covers, and responses by local decomposer communities. This article is protected by copyright. All rights reserved.

Description: Soils are subject to varying degrees of direct or indirect human disturbance, constituting a major global change driver. Factoring out natural from direct and indirect human influence is not always straightforward, but some human activities have clear impacts. These include land use change, land management, and land degradation (erosion, compaction, sealing and salinization). The intensity of land use also exerts a great impact on soils, and soils are also subject to indirect impacts arising from human activity, such as acid deposition (sulphur and nitrogen) and heavy metal pollution. In this critical review, we report the state-of-the-art understanding of these global change pressures on soils, identify knowledge gaps and research challenges, and highlight actions and policies to minimise adverse environmental impacts arising from these global change drivers. Soils are central to considerations of what constitutes sustainable intensification. Therefore, ensuring that vulnerable and high environmental value soils are considered when protecting important habitats and ecosystems, will help to reduce the pressure on land from global change drivers. To ensure that soils are protected as part of wider environmental efforts, a global soil resilience programme should be considered, to monitor, recover or sustain soil fertility and function, and to enhance the ecosystem services provided by soils. Soils cannot, and should not, be considered in isolation of the ecosystems that they underpin and vice versa. The role of soils in supporting ecosystems and natural capital needs greater recognition. The lasting legacy of the International Year of Soils in 2015 should be to put soils at the centre of policy supporting environmental protection and sustainable development. This article is protected by copyright. All rights reserved.

Description: The response of soil organic carbon (SOC) pools to globally rising surface temperature crucially determines the feedback between climate change and the global carbon cycle. However, there is a lack of studies investigating the temperature sensitivity of decomposition for decadally cycling SOC which is the main component of total soil carbon stock and the most relevant to global change. We tackled this issue by using two decadally 13 C-labeled soils and a much improved measuring system in a long-term incubation experiment. Results indicated that the temperature sensitivity of decomposition for decadally-cycling SOC (〉 23 years in one soil and 〉 55 years in the other soil) was significantly greater than that for faster-cycling SOC (〈 23 or 55 years) or for the entire SOC stock. Moreover, decadally-cycling SOC contributed substantially (35-59%) to the total CO 2 loss during the 360-day incubation. Overall, these results indicate that the decomposition of decadally-cycling SOC is highly sensitive to temperature change, which will likely make this large SOC stock vulnerable to loss by global warming in the 21 st century and beyond. This article is protected by copyright. All rights reserved.

Description: Human induced climate change is projected to increase ocean temperature and modify circulation patterns, with potential widespread implications for the transport and survival of planktonic larvae of marine organisms. Circulation affects the dispersal of larvae, whereas temperature impacts larval development and survival. However, the combined effect of changes in circulation and temperature on larval dispersal and survival has not been studied in a future climate scenario. Such understanding is crucial to predict future species distributions, anticipate ecosystem shifts, and design effective management strategies. We simulate contemporary (1990s) and future (2060s) dispersal of lobster larvae using an eddy-resolving ocean model in south-eastern Australia, a region of rapid ocean warming. Here we show that the effects of changes in circulation and temperature can counter each other: ocean warming favours the survival of lobster larvae, whereas a strengthened western boundary current diminishes the supply of larvae to the coast by restricting cross-current larval dispersal. Furthermore, we find that changes in circulation have a stronger effect on connectivity patterns of lobster larvae along south-eastern Australia than ocean warming in the future climate so that the supply of larvae to the coast reduces by ~ 4% and the settlement peak shifts poleward by ~270km in the model simulation. Thus ocean circulation may be one of the dominant factors contributing to the climate-induced expansion of species ranges. This article is protected by copyright. All rights reserved.

Description: Multiple doping is widely used to improve the performance of a material, including its electrical transport, mechanical, and photovoltaic properties. In this paper, Sn–Se dual-doped Li 10 GeP 2 S 12 (LGPS, thio-LISICON II analogue) electrolytes were synthesized via ball milling and sintering and compared with those Sn or Se single-doped. Successful Sn and/or Se substitution expanded the unit cell and formed units, which were verified by X-ray powder diffraction, energy-dispersive X-ray spectroscopy, and Raman spectroscopy. In contrast to the limited benefits of Se single doping and the negative effects of Sn single doping, Sn–Se dual doping demonstrated up to 53% enhancement in ionic conductivity. More importantly, Sn–Se dual-doped LGPS showed an extremely low activation energy of 16 kJ/mol, which is one of the lowest known values for lithium ion conductors; as well as one of the widest electrochemical windows of 8 V. Sn–Se dual-doped LGPS is a promising electrolyte for advanced all-solid-state batteries.

Description: The zooplankton of the northern California Current are typically characterized by an abundance of lipid-rich copepods that support rapid growth and survival of ecologically, commercially, and recreationally valued fish, birds, and mammals. Disruption of this food chain and reduced ecosystem productivity are often associated with climatic variability such as El Niño events. We examined the variability in timing, magnitude, and duration of positive temperature anomalies and changes in copepod species composition in the northern California Current in relation to ten tropical El Niño events. Measureable impacts on mesozooplankton of the northern California Current were observed during seven out of ten of these events. The occurrence of anomalously warm water and the response of the copepod community was rapid (lag of zero to two months) following the initiation of canonical Eastern Pacific events, but delayed (lag of two to eight months) following “Modoki” Central Pacific events. The variable lags in the timing of a physical and biological response led to impacts in the northern California Current peaking in winter during EP events and in the spring during CP events. The magnitude and duration of the temperature and copepod anomalies were strongly and positively related to the magnitude and duration of El Niño events, but were also sensitive to the phase of the lower-frequency Pacific Decadal Oscillation. When fisheries managers and biological oceanographers are faced with the prospect of a future El Niño event, prudent management and observation will require consideration of the background oceanographic conditions, the type of event, and both the magnitude and duration of the event when assessing the potential physical and biological impacts on the northern California Current. This article is protected by copyright. All rights reserved.

Description: Polycrystalline Cd 1− x Ba x O (0 ≤  x  ≤ 0.08) ceramics were synthesized via conventional solid-state reaction method, and the effect of Ba 2+ doping on the microstructure as well as the thermoelectric transport properties of the samples were investigated. It was found that doping of Ba 2+ can inhibit the grain growth of CdO, resulting in a considerable reduction in grain size. Moreover, with the increase in Ba 2+ doping content, both the electrical conductivity and the thermal conductivity of Cd 1− x Ba x O decreased, whereas the Seebeck coefficient increased. A high ZT value of 0.47 was achieved for Cd 0.99 Ba 0.01 O at 1000 K, 38% higher than the undoped CdO, mostly due to reduction of the thermal conductivity.

Description: Time series of environmental measurements are essential for detecting, measuring and understanding changes in the Earth system and its biological communities. Observational series have accumulated over the past 2-5 decades from measurements across the world's estuaries, bays, lagoons, inland seas and shelf waters influenced by runoff. We synthesize information contained in these time series to develop a global view of changes occurring in marine systems influenced by connectivity to land. Our review is organized around four themes: (1) human activities as drivers of change; (2) variability of the climate system as a driver of change; (3) successes, disappointments and challenges of managing change at the sea-land interface; and (4) discoveries made from observations over time. Multidecadal time series reveal that many of the world's estuarine-coastal ecosystems are in a continuing state of change, and the pace of change is faster than we could have imagined a decade ago. Some have been transformed into novel ecosystems with habitats, biogeochemistry and biological communities outside the natural range of variability. Change takes many forms including linear and nonlinear trends, abrupt state changes, and oscillations. The challenge of managing change is daunting in the coastal zone where diverse human pressures are concentrated and intersect with different responses to climate variability over land and over ocean basins. The pace of change in estuarine-coastal ecosystems will likely accelerate as the human population and economies continue to grow and as global climate change accelerates. Wise stewardship of the resources upon which we depend is critically dependent upon a continuing flow of information from observations to measure, understand and anticipate future changes along the world's coastlines. This article is protected by copyright. All rights reserved.

Description: Soil is the largest stock of carbon (C) in the terrestrial biosphere, so even slight changes in soil C stock may induce significant fluctuations in the atmospheric C dioxide (CO 2 ) concentration. Early coupled C-climate models predicted that positive C-climate feedback would be triggered due to the acceleration of C release to the atmosphere under future climate warming (Cox et al ., 2000). However, due to the omission of key microbial components and biogeochemical mechanisms in these models (Wieder et al ., 2013), these predictions remain controversial, because soil C dynamics is still highly uncertain among results simulated by 11 Earth system models (ESMs) involved in CMIP5 (Ciais et al ., 2013). This article is protected by copyright. All rights reserved.

Description: The influence of human activity on the biosphere is increasing. While direct damage (e.g. habitat destruction) is relatively well understood, many activities affect wildlife in less apparent ways. Here we investigate how anthropogenic noise impairs foraging, which has direct consequences for animal survival and reproductive success. Noise can disturb foraging via several mechanisms that may operate simultaneously, and thus their effects could not be disentangled hitherto. We developed a diagnostic framework that can be applied to identify the potential mechanisms of disturbance in any species capable of detecting the noise. We tested this framework using Daubenton's bats, which find prey by echolocation. We found that traffic noise reduced foraging efficiency in most bats. Unexpectedly, this effect was present even if the playback noise did not overlap in frequency with the prey echoes. Neither overlapping nor non-overlapping noise influenced the search effort required for a successful prey capture. Hence, noise did not mask prey echoes or reduce the attention of bats. Instead, noise acted as an aversive stimulus that caused avoidance response, thereby reducing foraging efficiency. We conclude that conservation policies may seriously underestimate numbers of species affected and the multilevel effects on animal fitness, if the mechanisms of disturbance are not considered. This article is protected by copyright. All rights reserved.

Description: Understanding the responses of lake systems to past climate change and human activity is critical for assessing and predicting the fate of lake carbon (C) in the future. In this study we synthesized records of the sediment accumulation from 82 lakes and of C sequestration from 58 lakes with direct organic C measurements throughout China. We also identified the controlling factors of the long-term sediment and C accumulation dynamics in these lakes during the past 12 ka (1 ka = 1000 cal yr BP). Our results indicated an overall increasing trend of sediment and C accumulation since 12 ka, with an accumulation peak in the last couple of millennia for all lakes in China, corresponding to terrestrial organic matter input due to land use change. The Holocene lake sediment accumulation rate (SAR) and C accumulation rate (CAR) averaged (Mean ± SE) 0.47 ± 0.05 mm yr -1 and 7.7 ± 1.4 g C m -2 yr -1 in China, respectively, comparable to the previous estimates for boreal and temperate regions. The SAR for lakes in the East Plain of subtropical China (1.05 ± 0.28 mm yr -1 ) was higher than those in other regions ( P 〈 0.05). However, CAR did not vary significantly among regions. Overall, the variability and history of climate and anthropogenic interference regulated the temporal and spatial dynamics of sediment and C sequestration for lakes in China. We estimated the total amount of C burial in lakes of China as 8.0 ± 1.0 Pg C. This first estimation of total C storage and dynamics in lakes of China confirms the importance of lakes in land C budget in monsoon-influenced regions. This article is protected by copyright. All rights reserved.

Description: Crystalline argon oxygen decarburization slag, in powdery form, was investigated for its hydration potential by alkali activation and curing at 80°C. Na-silicate and K-silicate of the same modulus were used as activators. Isothermal calorimetry at 80°C indicated exothermic reactions in the slag pastes. When the slag mortars were cured under steam at 80°C appreciable gain in compressive strength was measured. This was attributed to C–S–H which was detected in TG, FTIR, and 29 Si NMR analyses. Upon hydration at 90 d, the amount of crystalline phases decreased, whereas the XRD amorphous content in the slag increased. Electron microscopy showed the formation of different morphologies of reaction products depending on the alkaline activator employed. Presence of reaction rims around the crystalline phases with a major presence of Ca, Si, and O in the reacted matrix was observed in elemental maps.

Description: The (1− x )BiFeO 3 - x BaTiO 3 (with x  = 0.1, 0.2, 0.3, and 0.4) ceramics were fabricated successfully by solid-state reaction method. Single-phase perovskite was obtained in all ceramics, as confirmed by XRD technique. It was observed that 0.7BiFeO 3 –0.3BaTiO 3 was the morphotropic phase boundary (MPB) between rhombohedral and cubic phases, as also revealed from ferroelectric and magnetic properties. The simulated and experimental X-Ray Absorption Spectroscopy (XAS) study revealed that BT in 0.75BF-0.25BT is possibly taken a rhombohedral structure. Furthermore, the rounded ferroelectric hysteresis loops observed for 0.9BiFeO 3 –0.1BaTiO 3 and 0.8BiFeO 3 –0.2BaTiO 3 compositions could be attributed to their microstructure and surface charge effects and electron transfer between Fe 3+ and Fe 2+ ions. It was also found that high dielectric constant of 0.9BiFeO 3 –0.1BaTiO 3 composition was a result of grain and grain-boundary effects, as observed in SEM micrographs. In addition, a strong signature of dielectric relaxation behavior was observed in this ceramic system with the activation energy 0.467 eV obtained from the Arrhenius' law. Finally, the local structure investigation with XAS technique provided additional information to better understand the electric and magnetic properties in the BF-BT ceramic system.

Description: In this study, ZnS powders with homogeneous morphology were synthesized using a colloidal processing method. Vacuum hot pressing was subsequently applied to consolidate the ZnS powders into infrared transparent ceramics (77.3% transmittance at wavelengths of 6.74 and 9.29 μm). The phase composition of the sintered ZnS suggests the presence of wurtzite as a minor phase in addition to the primary sphalerite phase, and microstructural analysis indicates that the ceramics are highly densified. It has been found that the VHP-sintered ZnS ceramics exhibit blue (450 nm) and green (530 nm) luminescence, which is due to the formation of zinc vacancies and sulfur interstitials, respectively, during the sintering process.

Description: In this study, tribological investigations were carried out on ZTA ceramics with 17 vol% Y-TZP and different stabilizer contents (1, 1.5, and 2 mol% yttria) to analyze the influence of zirconia transformation on wear properties. Samples were tested in a linearly reciprocating ball on flat setup with different applied loads. Raising the fracture toughness by transformation toughening, microcracking, and residual stresses improves the wear resistance only at transition load but increases the wear at high loads. Higher yttria content of 2 mol% and lower zirconia grain size and thus low transformability, decreases fracture toughness but increases the wear resistance at high loads. Therefore the adjustment of stabilizer content on zirconia volume fraction in ZTA plays a decisive role in tribological applications.

Description: Highly (100)-oriented 0.38Bi(Ni 1/2 Hf 1/2 )O 3 -0.62PbTiO 3 relaxor-ferroelectric films were fabricated on Pt(111)/Ti/SiO 2 /Si(111) substrates by introducing a lead oxide seeding layer. A moderate relative permittivity , a low dissipation factor (tan δ 〈 5%), and strong relaxor-like behavior (γ = 0.74) over a broad temperature region were observed. The energy storage density of approximately 45.1 ± 2.3 J/cm 3 was achieved for films with (100) preferential orientation, which is much higher than the value ~33.5 ± 1.7 J/cm 3 obtained from films with random orientation. Furthermore, the PbO-seeded films are more capable of providing larger piezoelectric response (~113 ± 10 pm/V) compared to the films without seeds (~85 ± 8 pm/V). These excellent features indicate that the highly (100)-oriented 0.38Bi(Ni 1/2 Hf 1/2 )O 3 -0.62PbTiO 3 films could be promising candidates for applications in high-energy storage capacitors, high-performance MEMS devices, and particularly for potential applications in the next-generation integrated multifunctional piezoelectric energy harvesting and storage system.

Description: Uniformly dispersed TiC nanoparticle strengthened In 4 Se 2.65 composites have been fabricated by a combined process of mechanical alloying (MA) and hot pressing (HP) successfully. Due to the good electrical conductivity and the extra phonon scattering effect of the TiC nanoinclusions, the electrical resistivity and thermal conductivity decrease with the TiC content up to 0.8 wt%, and a maximum ZT of 0.98 at 723 K was achieved in the sample with 0.8 wt% TiC. Taking account of the measurement uncertainly, the enhancement of ZT value by TiC nanoinclusions is less obvious. On the other hand, the mechanical performance of In 4 Se 2.65 can be effectively improved by TiC nanoinclusions due to the dispersive strengthening effect of the nanoinclusions , and the flexural strength of the sample with 0.8 wt% TiC is improved to 73 MPa, which is over 40% higher than that of the pristine sample.

Description: The radiation damage response of Ti 3 SiC 2 heated from 120°C to 850°C during 700 keV Si + irradiation has been investigated. The samples were analyzed using glancing incidence X-ray diffraction, Rutherford backscattering spectrometry, Raman spectroscopy, and scanning electron microscopy. For the sample at 120°C, irradiation results in a buildup of a heterogeneous surface and the formation of TiC x . Irradiation at 200°C results in maximum microstrain, a maximum in the c lattice parameter, and the appearance of a β phase in addition to the normal α phase of Ti 3 SiC 2. A minimum in the observed damage level near the surface was seen for irradiation at a sample temperature of 300°C but the damaged phase increases at higher temperatures. Differences between the present work and a previous C irradiation study have been ascribed to the enhanced Si defect transport at low temperatures.

Description: There is concern that food insecurity will increase in southern Africa due to climate change. We quantified the response of maize yield to projected climate change and to three key management options – planting date, fertilizer use and cultivar choice – using the crop simulation model APSIM at two contrasting sites in Zimbabwe. Three climate periods up to 2100 were selected to cover both near- and long-term climates. Future climate data under two radiative forcing scenarios were generated from five Global Circulation Models. The temperature is projected to increase significantly in Zimbabwe by 2100 with no significant change in mean annual total rainfall. When planting before mid-December with a high fertilizer rate, the simulated average grain yield for all three maize cultivars declined by 13% for the periods 2010-2039 and 2040-2069, and by 20% for 2070-2099 compared with the baseline climate, under low radiative forcing. Larger declines in yield of up to 32% were predicted for 2070-2099 with high radiative forcing. Despite differences in annual rainfall, similar trends in yield changes were observed for the two sites studied, Hwedza and Makoni. The yield response to delay in planting was non-linear. Fertilizer increased yield significantly under both baseline and future climates. The response of maize to mineral nitrogen decreased with progressing climate change, implying a decrease in the optimal fertilizer rate in the future. Our results suggest that in the near future improved crop and soil fertility management will remain important for enhanced maize yield. Towards the end of the 21st Century, however, none of the farm management options tested in the study can avoid large yield losses in southern Africa due to climate change. There is a need to transform the current cropping systems of southern Africa to offset the negative impacts of climate change. This article is protected by copyright. All rights reserved.

Description: Fresh waters make a disproportionately large contribution to greenhouse gas (GHG) emissions, with shallow lakes being particular hotspots. Given their global prevalence, how GHG fluxes from shallow lakes are altered by climate change may have profound implications for the global carbon cycle. Empirical evidence for the temperature dependence of the processes controlling GHG production in natural systems is largely based on the correlation between seasonal temperature variation and seasonal change in GHG fluxes. However, ecosystem-level GHG fluxes could be influenced by factors, which whilst varying seasonally with temperature are actually either indirectly related (e.g. primary producer biomass) or largely unrelated to temperature, for instance nutrient loading. Here, we present results from the longest running shallow-lake mesocosm experiment which demonstrate that nutrient concentrations override temperature as a control of both the total and individual GHG flux. Furthermore, testing for temperature treatment effects at low and high nutrient levels separately showed only one, rather weak, positive effect of temperature (CH 4 flux at high nutrients). In contrast, at low nutrients, the CO 2 efflux was lower in the elevated temperature treatments, with no significant effect on CH 4 or N 2 O fluxes. Further analysis identified possible indirect effects of temperature treatment. For example, at low nutrient levels increased macrophyte abundance was associated with significantly reduced fluxes of both CH 4 and CO 2 for both total annual flux and monthly observation data. As macrophyte abundance was positively related to temperature treatment, this suggests the possibility of indirect temperature effects, via macrophyte abundance, on CH 4 and CO 2 flux. These findings indicate that fluxes of GHGs from shallow lakes may be controlled more by factors indirectly related to temperature, in this case nutrient concentration and the abundance of primary producers. Thus, at ecosystem scale response to climate change may not follow predictions based on the temperature dependence of metabolic processes. This article is protected by copyright. All rights reserved.

Description: The temperature distribution in copper and martensitic steel spheres has been investigated for the initial stage of field-activated sintering (FAST)/spark plasma sintering (SPS) using capacitor discharges (CD) with applied voltages from one to 15 V as model experiments. At first, the evolution of the contact resistance between the spheres has been studied. The results show the reduction in the contact resistance after discharge with increasing electrical load, yet no significant dependence on the length or number of the discharge pulses. Thereby the initial resistance is only decreased distinctly if at least a certain minimal voltage was applied. Subsequently, the melting of thin coatings of different metals on copper spheres has been studied and the occurrence of molten phase and its melting point were assigned to the corresponding discharge current. Extrapolation from the currents necessary to melt the coating layers in the CD experiments to lower values typical for FAST was used to estimate the contact overtemperature in the latter case. Resulting values for copper range from 0.05 K for normal heating with 100 K/min to 5 K for maximum current output.

Description: In this study, we report on the microstructure of SiO 2 -coated Al-doped ZnO nanoparticles densified by spark plasma sintering(SPS), using a multiscale approach. Our observations show that it is possible to successfully prepare dense pellets while keeping the nanostructure with well-defined Si-rich grain boundaries. Although a very limited partial solubility of Si in the ZnO matrix has been observed, Si is mostly concentrated at the grain boundaries. More surprisingly, we evidenced some areas with nanoscale inhomogeneity of the Al concentration, which can locally strongly exceed the average composition of the matrix. It could explain the apparent discrepancy observed in the literature between the simultaneous presence of ZnAl 2 O 4 in Al-doped ZnO, which should be the signature of the doping level exceeding the solubility limit, and the concentration of carriers that still depends on the nominal Al concentration in ZnO even in the presence of ZnAl 2 O 4 .

Description: The tropical coffee crop has been predicted to be threatened by future climate changes and global warming. However, the real biological effects of such changes remain unknown. Therefore, this work aims to link the physiological and biochemical responses of photosynthesis to elevated air [CO 2 ] and temperature in cultivated genotypes of Coffea arabica L. (cv. Icatu and IPR108) and C. canephora cv. Conilon CL153. Plants were grown for 1 year at 25/20ºC (day/night) and 380 or 700 μL CO 2 L -1 , then subjected to temperature increase (0.5ºC/day) to 42/34ºC. Leaf impacts related to stomatal traits, gas exchanges, C-isotope composition, fluorescence parameters, thylakoid electron transport and enzyme activities were assessed at 25/20ºC, 31/25ºC, 37/30ºC and 42/34ºC. The results showed that 1) both species were remarkably heat tolerant up to 37/30ºC, but at 42/34ºC a threshold for irreversible non-stomatal deleterious effects was reached. Impairments were greater in C. arabica (especially in Icatu) and under normal [CO 2 ]. Photosystems and thylakoid electron transport were shown to be quite heat tolerant, contrasting to the enzymes related to energy metabolism, including RuBisCO, which were the most sensitive components. 2) Significant stomatal trait modifications were promoted almost exclusively by temperature and were species dependent. Elevated [CO 2 ] 3) strongly mitigated the impact of temperature on both species, particularly at 42/34ºC, modifying the response to supra-optimal temperatures, 4) promoted higher water use efficiency under moderately higher temperature (31/25 ºC), and 5) did not provoke photosynthetic down-regulation. Instead, enhancements in [CO 2 ] strengthened photosynthetic photochemical efficiency, energy use and biochemical functioning at all temperatures.. Our novel findings demonstrate a relevant heat resilience of coffee species and that elevated [CO 2 ] remarkably mitigated the impact of heat on coffee physiology, therefore playing a key role in this crop sustainability under future climate change scenarios. This article is protected by copyright. All rights reserved.

Description: Protected areas (PAs) are an essential tool for the conservation of biodiversity globally. Previous studies have focussed on the effectiveness of PAs and the design of optimal PA networks. However, not all PAs remain intact permanently; many PAs undergo downgrading, downsizing and/or degazettement (PADDD), a fact largely ignored until recently. The drivers of enacted PADDD events and the factors influencing its spatial occurrence are poorly understood, potentially undermining the efficacy of PAs and PA networks. Here we examine the spatial relationship between PADDD and economic, demographic, and structural variables, using a 110 year dataset of 342 enacted PADDD events across 44 countries in the tropics and sub tropics. We find that the probability of an enacted PADDD event increases with the size of the PA and through a synergistic interaction between PA size and local population densities. Our results are robust to the under-reporting of enacted PADDD events that occur among smaller PAs and in regions with lower population density. We find an economic motive for PADDD events, given that the opportunity costs associated with larger PAs are higher, on average, than smaller PAs. Our findings suggest a need for conservation practitioners to better consider PA characteristics, as well as the social, economic, and political context in which PAs are situated, to aid the creation of more efficient and sustainable PA networks. In particular, the dynamics of enacted PADDD events highlight the need to explicitly consider PA robustness as a core component of systematic conservation planning for PA networks. This article is protected by copyright. All rights reserved.

Description: Assuming that co-distributed species are exposed to similar environmental conditions, ecological niche models (ENMs) of bird and plant species inhabiting tropical dry forests (TDFs) in Mexico were developed to evaluate future projections of their distribution for the years 2050 and 2070. We used ENM-based predictions and climatic data for two Global Climate Models, considering two Representative Concentration Pathway scenarios (RCP4.5 / RCP8.5). We also evaluated the effects of habitat loss and the importance of the Mexican system of Protected Areas (PAs) on the projected models for a more detailed prediction of TDFs and to identify hotspots that require conservation actions. We identified four major distributional areas: the main one located along the Pacific Coast (from Sonora to Chiapas, including the Cape and Bajío regions, and the Balsas river basin), and three isolated areas: the Yucatán peninsula, central Veracruz, and southern Tamaulipas. When considering the effect of habitat loss, a significant reduction (~61%) of the TDFs predicted area occurred, whereas climate change models suggested (in comparison to the present distribution model) an increase in area of 3.0-10.0% and 3.0-9.0% for 2050 and 2070, respectively. In future scenarios, TDFs will occupy areas above its current average elevational distribution that are outside of its present geographical range. Our findings show that TDFs may persist in Mexican territory until the middle of the XXI century; however, the challenges about long-term conservation are partially addressed (only 7% unaffected within the Mexican network of PAs) with the current Mexican PAs network. Based on our ENM approach, we suggests that a combination of models of species inhabiting present TDFs and taking into account change scenarios represent an invaluable tool in order to create new PAs and ecological corridors, as a response to the increasing levels of habitat destruction and the effects of climate change on this ecosystem. This article is protected by copyright. All rights reserved.

Description: Avian communities of arid ecosystems may be particularly vulnerable to global climate change due to the magnitude of projected change for desert regions and the inherent challenges for species residing in resource limited ecosystems. How arid-zone birds will be affected by rapid increases in air temperature and increased drought frequency and severity is poorly understood because avian responses to climate change have primarily been studied in the relatively mesic northern temperate regions. We studied the effects of increasing air temperature and aridity on a Burrowing Owl ( Athene cunicularia ) population in the southwestern USA from 1998-2013. Over 16 years, the breeding population declined 98.1%, from 52 pairs to 1 pair, and nest success and fledgling output also declined significantly. These trends were strongly associated with the combined effects of decreased precipitation and increased air temperature. Arrival on the breeding grounds, pair formation, nest initiation, and hatch dates all showed significant delays ranging from 9.4 to 25.1 days over 9 years, which have negative effects on reproduction. Adult and juvenile body mass decreased significantly over time, with a loss of 7.9% mass in adult males and 10.9% mass in adult females over 16 years, and a loss of 20.0% mass in nestlings over 8 years. Taken together, these population and reproductive trends have serious implications for local population persistence. The southwestern USA has been identified as a climate change hotspot, with projections of warmer temperatures, less winter precipitation, and an increase in frequency and severity of extreme events including drought and heat waves. An increasingly warm and dry climate may contribute to this species’ decline, and may already be a driving force of their apparent decline in the desert southwest. This article is protected by copyright. All rights reserved.

Description: Cities are growing rapidly, thereby expected to cause a large-scale global biotic homogenization. Evidence for the homogenization hypothesis is mostly derived from plants and birds, whereas arthropods have so far been neglected. Here, I tested the homogenization hypothesis with three insect indicator groups, namely true bugs, leafhoppers, and beetles. In particular, I was interested whether insect species community composition differs between urban and rural areas, whether they are more similar between cities than between rural areas, and whether the found pattern is explained by true species turnover, species diversity gradients and geographic distance, by non-native or specialist species, respectively. I analysed insect species communities sampled on birch trees in a total of six Swiss cities and six rural areas nearby. In all indicator groups urban and rural community composition was significantly dissimilar due to native species turnover. Further, for bug and leafhopper communities I found evidence for large-scale homogenization due to urbanization, which was driven by reduced species turnover of specialist species in cities. Species turnover of beetle communities was similar between cities and rural areas. Interestingly, when specialist species of beetles were excluded from the analyses, cities were more dissimilar than rural areas, suggesting biotic differentiation of beetle communities in cities. Non-native species did not affect species turnover of the insect groups. However, given non-native arthropod species are increasing rapidly their homogenizing effect might be detected more often in future. Overall, the results show that urbanization has a negative large-scale impact on the diversity specialist species of the investigated insect groups. Specific measures in cities targeted at increasing the persistence of specialist species typical for the respective biogeographic region could help to stop the loss of biodiversity. This article is protected by copyright. All rights reserved.

Description: Warming and eutrophication are two of the most important global change stressors for natural ecosystems, but their interaction is poorly understood. We used a dynamic model of complex, size-structured food webs to assess interactive effects on diversity and network structure. We found antagonistic impacts: warming increases diversity in eutrophic systems and decreases it in oligotrophic systems. These effects interact with the community size structure: communities of similarly-sized species such as parasitoid-host systems are stabilized by warming and destabilized by eutrophication, whereas the diversity of size-structured predator-prey networks decreases strongly with warming, but decreases only weakly with eutrophication. Non-random extinction risks for generalists and specialists lead to higher connectance in networks without size structure and lower connectance in size-structured communities. Overall, our results unravel interactive impacts of warming and eutrophication and suggest that size structure may serve as an important proxy for predicting the community sensitivity to these global change stressors. This article is protected by copyright. All rights reserved.

Description: Plastic marine debris pollution is rapidly becoming one of the critical environmental concerns facing wildlife in the 21st century. Here we present a risk analysis for plastic ingestion by sea turtles on a global scale. We combined global marine plastic distributions based on ocean drifter data with sea turtle habitat maps to predict exposure levels to plastic pollution. Empirical data from necropsies of deceased animals were then utilised to assess the consequence of exposure to plastics. We modelled the risk (probability of debris ingestion) by incorporating exposure to debris and consequence of exposure, and included life history stage, species of sea turtle and date of stranding observation as possible additional explanatory factors. Life history stage is the best predictor of debris ingestion, but the best-fit model also incorporates encounter rates within a limited distance from stranding location, marine debris predictions specific to the date of the stranding study and turtle species. There is no difference in ingestion rates between stranded turtles vs. those caught as bycatch from fishing activity, suggesting that stranded animals are not a biased representation of debris ingestion rates in the background population. Oceanic life-stage sea turtles are at the highest risk of debris ingestion, and olive ridley turtles are the most at-risk species. The regions of highest risk to global sea turtle populations are off of the east coasts of the USA, Australia and South Africa; the east Indian Ocean, and Southeast Asia. Model results can be used to predict the number of sea turtles globally at risk of debris ingestion. Based on currently available data, initial calculations indicate that up to 52% of sea turtles may have ingested debris.

Description: Global rice agriculture will be increasingly challenged by water scarcity, while at the same time changes in demand (e.g. changes in diets or increasing demand for biofuels) will feed back on agricultural practices. These factors are changing traditional cropping patterns from double-rice to the introduction of upland crops in the dry season. For a comprehensive assessment of greenhouse gas (GHG) balances, we measured methane (CH 4 ) / nitrous oxide (N 2 O) emissions and agronomic parameters over 2.5 years in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) in upland cultivation. Introduction of upland crops in the dry season reduced irrigation water use and CH 4 emissions by 66-81% and 95-99%, respectively. Moreover, for practices including upland crops, CH 4 emissions in the subsequent wet season with paddy rice were reduced by 54-60%. Although annual N 2 O emissions increased twice- to threefold in the diversified systems, the strong reduction of CH 4 led to a significantly lower (p〈0.05) annual GWP (CH 4 +N 2 O) as compared to the traditional double-rice cropping system. Measurements of soil organic carbon (SOC) contents before and three years after introduction of upland crop rotations indicated a SOC loss for the R-M system, while for the other systems SOC stocks were unaffected. This trend for R-M systems needs to be followed since it has significant consequences not only for the GWP balance but also with regard to soil fertility. Economic assessment showed a similar gross profit span for R-M and R-R, while gross profits for R-A were reduced as a consequence of lower productivity. Nevertheless, regarding a future increase of water scarcity it can be expected that mixed lowland-upland systems will expand in SE Asia as water requirements were cut by more than half in both rotation systems with upland crops. This article is protected by copyright. All rights reserved.

Description: Pressureless sintering is a well-established powder metallurgical route for processing and consolidation of mixed materials. Especially materials exhibiting a high melting point could be densified without tool abrasion by this sintering technique. As the sintering temperatures are often higher compared to pressure-assisted techniques care must be taken by means of grain growth. In our studies we used a ternary compound mixture to obtain Mo-based alloys. Consolidation applying pressure-assisted methods (hot pressing, spark plasma sintering) and pressureless sintering were used, respectively. The densities reached and the microstructures obtained were compared. These Mo–Si–B alloys were processed using a nitride-powder-based route offering lower impurity contents due to short processing times by avoiding time consuming mixing / milling steps. The sintering conditions depending on the powder particle size as well as the sample shape will be presented in detail. The composition investigated in this article offered a continuous α-Mo matrix with intermetallic islands consisting of Mo 3 Si and Mo 5 SiB 2 (T2) phases. The combination of a ductile α-Mo matrix and intermetallic phases embedded within offered an enhanced mechanical behavior at room temperature compared to MoSi 2 or other intermetallic alloys. Moreover, the intermetallic compounds as well as Mo are candidates for high-temperature applications. As the high-temperature behavior could be strongly influenced by the respective microstructure we present here the processing and the microstructure obtained.

Description: Agricultural systems are being challenged to decrease water use and increase production while climate becomes more variable and the world's population grows. Low water use efficiency is traditionally characterized by high water use relative to low grain production and usually occurs under dry conditions. However, when a cropping system fails to take advantage of available water during wet conditions, this is also an inefficiency and is often detrimental to the environment. Here we provide a systems-level definition of water use efficiency (sWUE) that addresses both production and environmental quality goals through incorporating all major system water losses (evapotranspiration, drainage, and runoff). We extensively calibrated and tested the Agricultural Production Systems sIMulator (APSIM) using six years of continuous crop and soil measurements in corn- and soybean-based cropping systems in central Iowa, USA. We then used the model to determine water use, loss, and grain production in each system and calculated sWUE in years that experienced drought, flood, or historically average precipitation. Systems water use efficiency was found to be greatest during years with average precipitation. Simulation analysis using 28 years of historical precipitation data, plus the same dataset with ± 15% variation in daily precipitation, showed that in this region 430 mm of seasonal (planting to harvesting) rainfall resulted in the optimum sWUE for corn, and 317 mm for soybean. Above these precipitation levels, the corn and soybean yields did not increase further, but the water loss from the system via runoff and drainage increased substantially, leading to a high likelihood of soil, nutrient, and pesticide movement from the field to waterways. As the Midwestern US is predicted to experience more frequent drought and flood, inefficiency of cropping systems water use will also increase. This work provides a framework to concurrently evaluate production and environmental performance of cropping systems. This article is protected by copyright. All rights reserved.

Description: The Southern Ocean ecosystem is undergoing rapid physical and biological changes that are likely to have profound implications for higher-order predators. Here we compare the long-term, historical responses of Southern Ocean predators to climate change. We examine palaeoecological evidence for changes in the abundance and distribution of seabirds and marine mammals, and place these into context with palaeoclimate records in order to identify key environmental drivers associated with population changes. Our synthesis revealed two key factors underlying Southern Ocean predator population changes; 1) the availability of ice-free ground for breeding, and 2) access to productive foraging grounds. The processes of glaciation and sea ice fluctuation were key; the distributions and abundances of elephant seals, snow petrels, gentoo, chinstrap and Adélie penguins all responded strongly to the emergence of new breeding habitat coincident with deglaciation and reductions in sea ice. Access to productive foraging grounds was another limiting factor, with snow petrels, king and emperor penguins all affected by reduced prey availability in the past. Several species were isolated in glacial refugia and there is evidence that refuge populations were supported by polynyas. While the underlying drivers of population change were similar across most Southern Ocean predators, the individual responses of species to environmental change varied because of species specific factors such as dispersal ability and environmental sensitivity. Such interspecific differences are likely to affect the future climate change responses of Southern Ocean marine predators and should be considered in conservation plans. Comparative palaeoecological studies are a valuable source of long-term data on species’ responses to environmental change that can provide important insights into future climate change responses. This synthesis highlights the importance of protecting productive foraging grounds proximate to breeding locations, as well as the potential role of polynyas as future Southern Ocean refugia. This article is protected by copyright. All rights reserved.

Description: As the most promising candidate of the solid electrolyte materials for future lithium batteries, oxide electrolytes with high–lithium-ion conductivity have experienced a rapid development in the past few decades. Existing oxide electrolytes are divided into two groups, i.e., crystalline group including NASICON, perovskite, garnet, and some newly developing structures, and amorphous/glass group including Li 2 O–MO x (M = Si, B, P, etc.) and LiPON-related materials. After a historical perspective on the general development of oxide electrolytes, we try to give a comprehensive review on the oxide electrolytes with high–lithium-ion conductivity, with special emphasis on the aspect of materials selection and design for applications as solid electrolytes in lithium batteries. Some successful examples and meaningful attempts on the incorporation of oxide electrolytes in lithium batteries are also presented. In the conclusion part, an outlook for the future direction of oxide electrolytes development is given.

Description: Dual-phase oxygen transport membranes are fast-growing research interest for application in oxyfuel combustion process. One such potential candidate is CGO-FCO (60 wt% Ce 0.8 Gd 0.2 O 2−δ –40 wt% FeCo 2 O 4 ) identified to provide good oxygen permeation flux with substantial stability in harsh atmosphere. Dense CGO-FCO membranes of 1 mm thickness were fabricated by sintering dry pellets pressed from powders synthesized by one-pot method (modified Pechini process) at 1200°C for 10 h. Microstructure analysis indicates presence of a third orthorhombic perovskite phase in the sintered composite. It was also identified that the spinel phase tends to form an oxygen deficient phase at the grain boundary of spinel and CGO phases. Surface exchange limitation of the membranes was overcome by La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ (LSCF) porous layer coating over the composite. The oxygen permeation flux of the CGO-FCO screen printed with a porous layer of 10 μm thick LSCF is 0.11 mL/cm 2 per minute at 850°C with argon as sweep and air as feed gas at the rates of 50 and 250 mL/min.