161,686 research outputs found

    The effectiveness of a social media intervention for reducing portion sizes in young adults and adolescents

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    open access journalAbstract Objective: Adolescents and young adults select larger portions of energy-dense food than recommended. The majority of young people have a social media profile, and peer influence on social media may moderate the size of portions selected. Methods: Two pilot-interventions examined whether exposure to images of peers’ portions of high-energy-dense (HED) snacks and sugar-sweetened-beverages (SSBs) on social media (Instagram) would influence reported desired portions selected on a survey. Confederate peers posted ‘their’ portions of HED snacks and SSBs on Instagram. At baseline and intervention end participants completed surveys that assessed desired portion sizes. Results: In intervention 1, Undergraduate students (N=20, Mean age=19.0y, SD=0.65y) participated in a two-week intervention in a within-subjects design. Participants reported smaller desired portions of HED snacks and SSBs following the intervention, and smaller desired portions of HED snacks for their peers. In intervention 2, adolescents (N=44, Mean age=14.4y, SD=1.06y) participated in a four-week intervention (n=23) or control condition (n=21) in a between-subjects design. Intervention 2 did not influence adolescents to reduce their desired reported portion sizes of HED snacks or SSBs relative to control. Conclusions: These preliminary studies demonstrated that social media is a feasible way to communicate with young people. However, while the intervention influenced young adults’ reported desired portions and social norms regarding their peers’ portions, no significant impact on desired reported portion sizes was found for HED snacks and SSBs in adolescents. Desired portion sizes of some foods and beverages may be resistant to change via a social media intervention in this age group

    “No Shut-off” Policies and Natural Gas Consumption

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    Many U.S. states have regulations that prevent natural gas utility companies from turning off service to non-paying consumers. The goal of these policies, termed “no shut-off” (NSO) regulations, is to provide a guaranteed minimum level of residential comfort by reducing the marginal cost of consumption to zero for a period of time. This paper employs a difference-in-difference approach applied to residential U.S. Energy Information Administration data to evaluate whether NSO policies generate higher levels of gas usage. Our preferred specifications suggest that activation of a NSO policy increases natural gas consumption by between 4.7–4.8%, resulting in a total increase of between 66 and 67 billion cubic feet of natural gas consumed per winter season in covered states, at a value of as much as $950–970 million annually

    Are Peer Effects Present in Residential Solar Installations? Evidence from Minnesota and Wisconsin

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    There are geographic differences in the rate of adoption of residential photovoltaic (PV) solar. Are adoption rates in small scale localities (counties and zip codes) influenced by previous, nearby adoptions? This paper adds to the literature on Peer Effects with an analysis of Minnesota and Wisconsin zip codes. I use residential adoption data from the OpenPV Project in an empirical analysis of social interactions. My findings indicate that there is a small but significant effect of nearby adoptions at the zip code level. These peer effects are shown to be nuanced by policy incentives such as the XCEL Solar Rewards Program. I additionally engage in a case study analysis of the relationship of some localities

    Comparative study of Sustainability Metrics for Face Milling AISI 1045 in different Machining Centers

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    Comunicación presentada a MESIC 2019 8th Manufacturing Engineering Society International Conference (Madrid, 19-21 de Junio de 2019)The objective of this study is to compare a set of sustainability metrics between different manufacturing resources applied to high performances machining centers. The research compares distributed scenarios in order to find the optimal conditions that allow the minimum consumed power and the minimum roughness when performing face milling operations of AISI 1045 steel. The set of experiments for the surface machining was carried out considering different path strategies in three main directions for two dimensional movements of the tool. The selected experiments considered the main axis movement, the perpendicular axis movement and a 45 degrees movement. Besides, it was considered the feed rate speed and the cutting depth. The design of experiments was developed with the Taguchi method considering an orthogonal matrix of L27 design type, and three levels of experimental design, and the analysis of variance and noise signal were performed. The methodology to determine the lowest power consumed and the best surface quality allowed to establish the working condition in the most sustainable machining. The results show how the cutting parameters influence in each manufacturing resource

    The Fire and Smoke Model Evaluation Experiment—A Plan for Integrated, Large Fire–Atmosphere Field Campaigns

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    The Fire and Smoke Model Evaluation Experiment (FASMEE) is designed to collect integrated observations from large wildland fires and provide evaluation datasets for new models and operational systems. Wildland fire, smoke dispersion, and atmospheric chemistry models have become more sophisticated, and next-generation operational models will require evaluation datasets that are coordinated and comprehensive for their evaluation and advancement. Integrated measurements are required, including ground-based observations of fuels and fire behavior, estimates of fire-emitted heat and emissions fluxes, and observations of near-source micrometeorology, plume properties, smoke dispersion, and atmospheric chemistry. To address these requirements the FASMEE campaign design includes a study plan to guide the suite of required measurements in forested sites representative of many prescribed burning programs in the southeastern United States and increasingly common high-intensity fires in the western United States. Here we provide an overview of the proposed experiment and recommendations for key measurements. The FASMEE study provides a template for additional large-scale experimental campaigns to advance fire science and operational fire and smoke models

    Encouraging pro-environmental behaviours: a review of methods and approaches. ESRI Working Paper No. 645 December 2019

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    Many urgent environmental problems can be mitigated with more sustainable use of resource. An acknowledgement of which is a growing interest among policy practitioners in encouraging pro-environmental behaviour change initiatives. The effect of anthropic pressure on the environment is long known and the first pro-environmental behaviour studies date back to the middle 1970s. Despite this, the scientific literature has not yet answered several questions: what are the most suitable ways to encourage behavioural changes? What are the barriers to project implementation? What are the long run effects of behavioural change projects? With this in mind, this contribution offers a review of the existing literature on behavioural change case studies and provides a categorisation of treatments and guidelines for successful project implementation. Five different approaches have been considered: education and awareness, social influence, relationship building, incentives and nudges, which have been used in experimental studies. On balance the case studies suggest that all approaches are suitable but their selection should be based on specific objectives and target population. Interestingly, the choice of the behaviour to change is rarely discussed before project implementation. This analysis also highlights that little is known on whether behaviour change projects achieve sustained pro-environmental behavioural change over time

    Daylighting Performance of Solar Control Films for Hospital Buildings in a Mediterranean Climate

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    One of the main retrofitting strategies in warm climates is the reduction of the effects of solar radiation. Cooling loads, and in turn, cooling consumption, can be reduced through the implementation of reflective materials such as solar control films. However, these devices may also negatively affect daylight illuminance conditions and the electric consumption of artificial lighting systems. In a hospital building, it is crucial to meet daylighting requirements as well as indoor illuminance levels and visibility from the inside, as these have a significant impact on health outcomes. The aim of this paper is to evaluate the influence on natural illuminance conditions of a solar control film installed on the windows of a public hospital building in a Mediterranean climate. To this end, a hospital room, with and without solar film, was monitored for a whole year. A descriptive statistical analysis was conducted on the use of artificial lighting, illuminance levels and rolling shutter aperture levels, as well as an analysis of natural illuminance and electric consumption of the artificial lighting system. The addition of a solar control film to the external surface of the window, in combination with the user-controlled rolling shutter aperture levels, has reduced the electric consumption of the artificial lighting system by 12.2%. Likewise, the solar control film has increased the percentage of annual hours with natural illuminance levels by 100–300 lux

    Indoor Air Quality Assessment: Comparison of Ventilation Scenarios for Retrofitting Classrooms in a Hot Climate

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    Current energy e ciency policies in buildings foster the promotion of energy retrofitting of the existing stock. In southern Spain, the most extensive public sector is that of educational buildings, which is especially subject to significant internal loads due to high occupancy. A large fraction of the energy retrofit strategies conducted to date have focused on energy aspects and indoor thermal comfort, repeatedly disregarding indoor air quality criteria. This research assesses indoor air quality in a school located in the Mediterranean area, with the objective of promoting di erent ventilation scenarios, based on occupancy patterns and carbon dioxide levels monitored on site. Results show that manual ventilation cannot guarantee minimum indoor quality levels following current standards. A constant ventilation based on CO2 levels allows 15% more thermal comfort hours a year to be reached, compared to CO2-based optimized demand-controlled ventilation. Nevertheless, the latter ensures 35% annual energy savings, compared to a constant CO2-based ventilation, and 37% more annual energy savings over that of a constant ventilation rate of outdoor air per person
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