Effects of virtual environment platforms on emotional responses

The goal of the current study was to investigate the effects of different virtual environment (VE) technologies (i.e., desktop, head mounted display, or fully immersive platforms) on emotional arousal and task performance. Fifty-three participants were recruited from a college population. Reactivity to stressful VEs was examined in three VE systems from desktop to high-end fully immersive systems. The experiment was a 3 (desktop system, head mounted display, and six wall system) × 2 (high- and low-stressful VE) within subject design, with self-reported emotional arousal and valence, skin conductance, task performance, presence, and simulator sickness examined as dependent variables. Replicating previous studies, the fully immersive system induced the highest sense of presence and the head mounted display system elicited the highest amount of simulator sickness. Extending previous studies, the results demonstrated that VE platforms were associated with different patterns in emotional responses and task performance. Our findings suggest that different VE systems may be appropriate for different scientific purposes when studying stress reactivity using emotionally evocative tasks.     

Evaluating display fidelity and interaction fidelity in a virtual reality game

In recent years, consumers have witnessed a technological revolution that has delivered more-realistic experiences in their own homes through high-definition, stereoscopic televisions and natural, gesture-based video game consoles. Although these experiences are more realistic, offering higher levels of fidelity, it is not clear how the increased display and interaction aspects of fidelity impact the user experience. Since immersive virtual reality (VR) allows us to achieve very high levels of fidelity, we designed and conducted a study that used a six-sided CAVE to evaluate display fidelity and interaction fidelity independently, at extremely high and low levels, for a VR first-person shooter (FPS) game. Our goal was to gain a better understanding of the effects of fidelity on the user in a complex, performance-intensive context. The results of our study indicate that both display and interaction fidelity significantly affect strategy and performance, as well as subjective judgments of presence, engagement, and usability. In particular, performance results were strongly in favor of two conditions: low-display, low-interaction fidelity (representative of traditional FPS games) and high-display, high-interaction fidelity (similar to the real world).     

Voltage pulsing for performance recovery of yttria-stabilised zirconia membranes in oxygen/sulfur dioxide separation

The regeneration of yttria-stabilized zirconia (YSZ) membranes exposed to high concentration sulfur dioxide in oxygen at 850 °C using DC voltage pulses was investigated by in-situ impedance spectroscopy. The membranes consisted of a dense YSZ layer as the solid electrolyte coated with two platinum layers as electrodes. On operation in the presence of SO₂, the serial resistance and polarization resistance of the Pt/YSZ cell increased. This is most likely due to the formation of sulfide at the interface area of the electrode and electrolyte combined with sulfur adsorption on electrode surface. DC Voltage pulses were found to have an effect on the charge transfer and mass transfer properties of the Pt/YSZ cell, assisting the removal of sulfur on the cathode surface and leading to performance recovery of the cell. In these experiments, the greatest rate of membrane performance recovery is achieved with a cathodic DC bias of 10 V, applied for 0.08 s. Higher or longer voltage pulses may cause the rate controlling step for the oxygen reduction reaction to shift to oxygen supplied in feed from oxygen surface exchange and diffusion processes. A relatively steady membrane performance was achieved during 20 h SO₂ exposure tests. It is concluded that DC voltage pulses show promise as a method for reducing the performance degradation effects of poisoning due to sulfur containing gases in the fields of fuel cells and in the sulfur family of thermochemical cycles.     

Comparison of 3D printed and molded carrots produced with gelatin,guar gum and xanthan gum

This study examined the effects of different hydrocolloids (guar gum, xanthan gum and gelatin) on the sensory and textural properties of pureed carrots. There were eight products involved in the study; 3D printed carrots and molded carrots without the addition of gums and with guar gum, xanthan gum and gelatin. All products were evaluated using trained panelists (n = 12) and underwent a texture profile analysis. No significant differences were found between the molded and 3D printed pureed carrots; instead, the samples were grouped based on the gum used in their production. The samples made with gelatin and xanthan gum were the hardest (texture profile analysis) and the densest samples when evaluated by the trained panelists. The 3D printing did not affect the taste properties of the pureed carrots, as they were evaluated to be similar to that of the molded carrots (p > .05). This study demonstrated that 3D printing did not affect the textural and sensory properties of pureed carrots when compared to molded carrots. However, changes in the printing parameters (infill percentage, nozzle diameter, flow rate, nozzle height) need to be evaluated to determine their effect on the sensory properties of 3D printed pureed carrots.     

The impact of large scale atmospheric circulation patterns on wind power generation and its potential predictability: A case study over the UK

Over recent years there has been an increasing deployment of renewable energy generation technologies, particularly large-scale wind farms. As wind farm deployment increases, it is vital to gain a good understanding of how the energy produced is affected by climate variations, over a wide range of time-scales, from short (hours to weeks) to long (months to decades) periods.By relating wind speed at specific sites in the UK to a large-scale climate pattern (the North Atlantic Oscillation or “NAO”), the power generated by a modelled wind turbine under three different NAO states is calculated. It was found that the wind conditions under these NAO states may yield a difference in the mean wind power output of up to 10%. A simple model is used to demonstrate that forecasts of future NAO states can potentially be used to improve month-ahead statistical forecasts of monthly-mean wind power generation.The results confirm that the NAO has a significant impact on the hourly-, daily- and monthly-mean power output distributions from the turbine with important implications for (a) the use of meteorological data (e.g. their relationship to large-scale climate patterns) in wind farm site assessment and, (b) the utilisation of seasonal-to-decadal climate forecasts to estimate future wind farm power output. This suggests that further research into the links between large-scale climate variability and wind power generation is both necessary and valuable.     

Insulin receptor substrate-2 in the ventral tegmental area regulates behavioral responses to cocaine.

Neurotrophic factor signaling modulates cellular and behavioral responses to drugs of abuse. Among other biochemical adaptations, chronic exposure to abused drugs decreases the expression of insulin receptor substrate-2 (IRS-2; a protein involved in neurotrophic signaling) in the ventral tegmental area (VTA), a neural substrate for many drugs of abuse. Using viral-mediated gene transfer to locally alter the activity of IRS-2, the authors show that overexpression of IRS-2 in the VTA results in an enhanced preference for environments previously paired with cocaine, as measured by the place conditioning paradigm, whereas blockade of IRS-2 activity results in avoidance of cocaine-paired compartments. In addition, IRS-2 overexpression leads to enhanced cocaine-induced locomotor activity, and blockade of IRS-2 expression significantly blunts behavioral responses to cocaine. These results demonstrate that levels of IRS-2 in the VTA regulate responsiveness to the behavioral effects of cocaine. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Affective and deliberative processes in risky choice: Age differences in risk taking in the Columbia Card Task.

The authors investigated risk taking and underlying information use in 13- to 16- and 17- to 19-year-old adolescents and in adults in 4 experiments, using a novel dynamic risk-taking task, the Columbia Card Task (CCT). The authors investigated risk taking under differential involvement of affective versus deliberative processes with 2 versions of the CCT, constituting the most direct test of a dual-system explanation of adolescent risk taking in the literature so far. The “hot” CCT was designed to trigger more affective decision making, whereas the “cold” CCT was designed to trigger more deliberative decision making. Differential involvement of affective versus deliberative processes in the 2 CCT versions was established by self-reports and assessment of electrodermal activity. Increased adolescent risk taking, coupled with simplified information use, was found in the hot but not the cold condition. Need-for-arousal predicted risk taking only in the hot condition, whereas executive functions predicted information use in the cold condition. Results are consistent with recent dual-system explanations of risk taking as the result of competition between affective processes and deliberative cognitive-control processes, with adolescents’ affective system tending to override the deliberative system in states of heightened emotional arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improved solvation routes for the Bunsen reaction in the sulphur iodine thermochemical cycle: Part I – Ionic liquids

The Bunsen reaction is central to the Sulphur Iodine cycle, however large excesses of both water and iodine are currently employed to enable phase separation of the two acids produced. This causes separation issues later in the cycle and induces a large thermal burden for water evaporation. The use of solvents in the reaction has the potential to reduce these large excesses, thereby increasing the cycle efficiency. This paper investigates ionic liquids as solvents for the Bunsen reaction. Several potential ionic liquids are identified based on their anion properties. The extraction of HI into the ionic liquid is then investigated experimentally. [FAP]⁻ ionic liquids were examined but their extreme hydrophobicity prevented water being taken up into the organic phase, severely retarding the extraction of acid by the solvent. Results for the [TMPP]⁻ ionic liquid showed discrepancies in the component balance and it is thought that the solvent may be susceptible to hydrolysis. The extraction of acid by the [Tf₂N]⁻ ionic liquids was more promising, the amount of acid extracted being of the order of 20%. However, the amount of protons and iodide ions extracted by the solvents were not equivalent and evidence is presented demonstrating the presence of an ion exchange mechanism. None of the ionic liquids tested are therefore suitable for use in the Bunsen reaction, however the properties of an ionic liquid can be tailored by the choice of anion and cation. Further investigation of ionic liquids is necessary before they can be conclusively ruled out.     

Sensory properties of thickened and protein-enriched plant-based frozen desserts

The number of consumers following plant-based diets has increased and in turn, the variety of plant-based foods available on the market has also increased. Many plant-based foods aim to mimic the functionality and sensory properties of conventional dairy products; however, they may not be suitable for specific populations. Dysphagia, for example, is a swallowing condition requiring texture-modified foods that meet specific criteria. While many conventional thickened products exist that are safe for individuals with dysphagia, the growing interest in plant-based eating alongside the increasing prevalence of dysphagia prompts a need for research on the use and safety of thickened plant-based alternatives. This study investigated the sensory properties of a thickened protein-enhanced ice cream (dairy and whey) compared to thickened protein-enhanced plant-based frozen desserts (cashew and pea, and coconut and pea). The formulations were evaluated using the International Dysphagia Diet Standardization (IDDSI) Spoon Tilt Test and a sensory trial (n = 104 participants, 47 flexitarians and 57 typical consumers) using static (hedonic scales and check-all-that-apply [CATA]), and dynamic (temporal check-all-that-apply (TCATA)) methods. The dairy and whey sample consistently passed the IDDSI test, while the plant-based samples did not. TCATA identified that the plant-based samples had an increased cohesiveness and adhesiveness, and decreased slipperiness when compared to the dairy and whey sample. The differences in textural properties may explain why the plant-based samples did not pass the IDDSI test. The study identified that although plant-based foods strive to mimic conventional dairy products, they have different textural and flavor properties.