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Abstract In the present paper we have investigated the high-pressure, structural phase transition of Barium chalcogenides (BaO, BaSe and BaTe) using a three-body interaction potential (MTBIP) approach, modified by incorporating covalency effects. Phase transition pressures are associated with a sudden collapse in volume. The phase transition pressures and associated volume collapses obtained from TBIP show a reasonably good agreement with experimental data. Here, the transition pressure, NaCl-CsCl structure increases with decreasing cation-to-anion radii ratio. In addition, the elastic constants and their combinations with pressure are also reported. It is found that TBP incorporating a covalency effect may predict the phase transition pressure, the elastic constants and the pressure derivatives of other chalcogenides as well.

It is well known that a wake will develop downstream of a tidal stream turbine owing to extraction of axial momentum across the rotor plane. To select a suitable layout for an array of horizontal axis tidal stream turbines, it is important to understand the extent and structure of the wakes of each turbine. Studies of wind turbines and isolated tidal stream turbines have shown that the velocity reduction in the wake of a single device is a function of the rotor operating state (specifically thrust), and that the rate of recovery of wake velocity is dependent on mixing between the wake and the surrounding flow. For an unbounded flow, the velocity of the surrounding flow is similar to that of the incident flow. However, the velocity of the surrounding flow will be increased by the presence of bounding surfaces formed by the bed and free surface, and by the wake of adjacent devices. This paper presents the results of an experimental study investigating the influence of such bounding surfaces on the structure of the wake of tidal stream turbines.

AbstractThe effect of ethanol on oil‐in‐water emulsions stabilized with low molecular weight surfactants was investigated. Oil‐in‐water emulsions were prepared containing varying percentages of ethanol and sunflower oil, and stabilized with different emulsifiers (Tween 20, Tween 80, and Lecithin). Droplet size, viscosity, density, and interfacial tension measurements were carried out. The droplet size of emulsions stabilized by each of the surfactants studied decreased with the addition of ethanol to the aqueous phase showing a minimum at a concentration of ethanol around 40%. The trend in droplet size is accompanied by a decrease in the interfacial tension between water and oil as the ethanol concentration increases. Viscosity measurements show that the change in viscosity of the final emulsion is the result of the change in viscosity of the continuous phase, as well as the change in solubility of the surfactants due to the addition of ethanol. The density of the continuous phase decreases with the addition of ethanol and it is possible to match the densities of the two phases in order to reduce the effect of creaming/sedimentation and improve stability. This study provides scientific evidence for the formulation of stable emulsions containing a range of ethanol form 0 to 40%.Practical ApplicationFormation and stability of food‐grade emulsions in the presence of ethanol.

Background:  A low level of response (i.e., a low LR) to alcohol is a genetically influenced phenotype that predicts later alcoholism. While the low LR reflects, at least in part, a low brain response to alcohol, the physiological underpinnings of the low LR have only recently been addressed. Methods:  Forty‐nine drinking but not yet alcoholic matched pairs of 18‐ to 25‐year‐old subjects (N = 98; 53% women) with low and high LRs as established in separate alcohol challenges were evaluated in 2 event‐related functional magnetic resonance imaging (fMRI) sessions (placebo and approximately 0.7 ml/kg of alcohol) while performing a validated stop signal task. The high and low LR groups had identical blood alcohol levels during the alcohol session. Results:  Significant high versus low LR group and LR group × condition effects were observed in blood oxygen level–dependent (BOLD) signal during error and inhibitory processing, despite similar LR group performance on the task. In most clusters with significant (corrected p < 0.05, clusters > 1,344 μl) LR group × alcohol/placebo condition interactions, the low LR group demonstrated relatively less, whereas the high LR group demonstrated more, error and inhibition‐related activation after alcohol compared with placebo. Conclusions:  This is one of the first fMRI studies to demonstrate significant differences between healthy groups with different risks of a future life‐threatening disorder. The results may suggest a brain mechanism that contributes to how a low LR might enhance the risk of future heavy drinking and alcohol dependence.

During recent years, the issue of gas flaring has become an increasingly relevant problem for the international community. The claim to more sustainable development offers a renewed prospective in the observation of gas flaring and emphasizes that recovering the associated gas could induce economic, environmental and social benefit. The true core of the issue, as is widely accepted, is not a lack of appropriate technologies, but in the number of criteria involved, which makes it difficult to identify a list of alternatives and connecting all the involved stakeholders in the negotiation process. The complexity of this problem can be mitigated using a decision-making method. The objective of the present work is to identify and formulate a supportive decision system based on the Analytic Hierarchy Process. Application of the model to a real case underlines the strengths and weaknesses of the model, leading to the conclusion that a selection of the most sustainable alternatives needs to be based on a number o...

Abstract The United States Department of Defense (DoD) is considering replacing the 2.8 billion gallons of petroleum jet fuel consumed within the continental United States (CONUS) annually with alternative jet fuels to reduce vulnerability to price and supply fluctuations and improve sustainability. We evaluate the feasibility of replacing DoD CONUS jet fuel with alternative jet fuel from domestic feedstocks and assess the cost, greenhouse gas (GHG) emissions, energy balance, land, water, and fertilizer impacts of nine alternative jet fuel pathways. The feedstocks include terrestrial crops (soy, corn, wood, and grass), marine microalgae, and by-products (forestry residue, municipal solid waste, and waste oil) converted by extraction, fermentation, or thermo-chemical conversion, paired with upgrading steps. We found that domestic biomass feedstocks can meet the DoD CONUS jet fuel demand without significantly affecting food supply. Alternative pathways cost more than petroleum jet fuel ($0.78 l-1 and emitting 89 g CO2 equivalent (CO2e) MJ−1), but many lowered GHG emissions. The forestry residue and waste oil pathways yielded the lowest costs ($0.92 and $0.82 l-1, respectively), decreased emissions (23 and 35 g CO2e MJ−1, respectively), and had negligible effects on land, water, and fertilizer resources. Tradeoffs among sustainability metrics are further explored with a sensitivity analysis and by evaluating carbon-cost scenarios.

Building energy flexibility has been increasingly demonstrated as a cost-effective solution to respond to the needs of energy networks, including electric grids and district cooling and heating systems, improving the integration of intermittent renewable energy sources. Adjusting zonal temperature set-points is one of the most promising measures to unlock the energy flexibility potential of central air conditioning systems in complex commercial buildings. However, most existing studies focused on quantifying the energy flexibility on the building level since only building-level energy consumption is normally metered in commercial buildings. This study aims to investigate the impacts of temperature set-point adjustment strategies on zone-level thermal and energy performance by developing a non-intrusive data-driven load disaggregation method (i.e., a virtual zonal power meter). Three university buildings in Northern California were selected to test the proposed load disaggregation method. We found that heterogeneities of energy use and energy flexibility existed across not only buildings but also air handling units (AHUs) and zones. Moreover, a small number of zones accounted for a large amount of energy use and energy flexibility; and the most energy-intensive zones are not necessarily the most energy-flexible zones. For the three tested buildings, the top 30% most energy-intensive zones accounted for around 60% of the total energy use; and the top 30% most energy-flexible zones provided around 80% of the total energy flexibility. The proposed method enables the electric grid or district energy system operators to regard the controlled energy-flexible entities as a fleet of AHUs or zones instead of a fleet of buildings and helps unlock the possibility for targeted demand flexibility strategies that balance zone-by-zone energy reduction with zone-by-zone costs to occupants. 33 pages, 18 figures

Shifts in the timing of phenological events across many taxa and ecosystems are a result of climate change. Within a trophic network, phenological mismatches between interlinked species can have negative impacts for biodiversity, ecosystems, and the trophic network. Here we developed interaction indices that quantify the level of synchrony and asynchrony among groups of species in three interlinked trophic levels, as well as accounting for a dynamic representation of meteorology. Insect first flight, vegetation green-up and arrival of migrant birds were the phenological indicators, obtained from a combination of spatially and temporally explicit species observations from citizen science programmes and remote sensing platforms (i.e., Landsat). To determine phenological shifts in interlinked taxa we created and applied several phenological indices of synchrony-asynchrony, combining information from the phenological events and critical time windows of meteorological variables. To demonstrate our method of incorporating a meteorological component in our new interaction index, we implemented the relative sliding time window analysis, a stepwise regression model, to identify critical time windows preceding the phenological events on a yearly basis. The new indices of phenological change identified several asynchronies within trophic levels, allowing exploration of potential interactions based on synchrony among interlinked species. Our novel index of synchrony-asynchrony including a meteorological dimension could be highly informative and should open new pathways for studying synchrony among species and interaction networks.