3,586 research outputs found

    What heavy weight buildings in hot climates can tell us about their thermal performance

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    Concrete, masonry walls and stone finishes are high density materials and have high thermal capacity, they are referred to as heavy-weight construction or thermal mass, which is the main construction type in Lebanon. Although thermal mass construction is usually recommended in hot climates in order to reduce internal temperature fluctuation, its actual thermal behavior in Lebanon is not well documented through direct observation, relying instead on its theoretical performance. This study’s main objective is to characterize the actual thermal performance of such construction, in the context of building occupancy and intermittent A/C usage. The paper starts with a brief introduction of the residential typologies in Lebanon followed by the description of the three thermally monitored apartments, in use or empty, located in one same neighborhood of Beirut, Lebanon. The monitoring was undertaken during summer 2015 using hourly data loggers. The analysis of the recorded data provides a clear and empirical understanding on: 1. how heavy weight buildings interact within the hot and humid climate of Beirut; 2. how the effect of regulating the internal thermal fluctuation is shown; and 3. what are the most influential factors that would further enhance thermal performance of thermal mass construction

    A review of minimum U-values for Lebanon and the associated effect of Internal gains

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    Since 2005 various publications have proposed different U-values to be used in Lebanon to reduce the buildings’ energy demand, creating confusion and a lack of specific and authoritative recommendation. Moreover, the various thermal performance guidelines are not easily comparable due to unexplained basic assumptions and guidance on the calculation of internal gains. This study has two interrelated objectives: a) test the most appropriate U-values for the climate of Beirut, b) study the consequence of increased internal gains have on the cooling energy load in low U-value construction. The paper does dynamic thermal simulation of the various U-values from local and international sources. The analysis allows the comparison and ranking of these various U-values based on the overall yearly energy demand for cooling. This is followed by a sensitivity study where a range of increased internal heat gains are inputted onto a low and a high U-value model to demonstrate that an increase in internal gains results in both models having the same cooling loads. Low U-values under this scenario due not result in a lower annual energy load. The study concludes that, although finding the appropriate U-value for hot climates seems uncontroversial, the effect of internal gains must be taken into consideration. Hence the importance of having consistent and harmonized national and regional benchmark values for U-values and internal gains

    Assessing suicide ideation among older adults: a systematic review of screening and measurement tools

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    Objectives: Rates of suicide in older adults may be higher than reported due to poor understandings of presentation of suicide ideation in this group. The objectives of this paper were to (i) review current measurement tools designed for older adults to detect suicide ideation and (ii) assess their psychometric properties. Design: We used a systematic review approach to identify measurement tools developed specifically for older adults without cognitive decline or impairment. Results: Ten articles that reported on a total of seven different measurement tools were identified. These included tools that focused on resiliency to suicide and those that measured risk of suicide behavior. There was wide variation across the articles: some were adaptations of existing scales to suit older populations, others were developed by authors; they varied in length from four to 69 items; a range of settings was used, and there was a mix of self-report and clinician-administered measures. Most displayed good psychometric properties, with both approaches showing similar quality. Limitations in terms of samples, settings, and measurement design are discussed. Conclusion: The case for specific measures for older adults is clear from this review. There appear to be unique factors that should be considered in understanding suicide ideation and behavior among older adults that may not be directly assessed in non-specific measurements. However, there is a need to expand the diversity of individuals included in measurement development to ensure they are appropriate across gender, culture and minority status, and for the views of professionals to be considered

    Knee joint neuromuscular activation performance during muscle damage and superimposed fatigue

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    This study examined the concurrent effects of exercise-induced muscle damage and superimposed acute fatigue on the neuromuscular activation performance of the knee flexors of nine males (age: 26.7 ± 6.1yrs; height 1.81 ± 0.05m; body mass 81.2 ± 11.7kg [mean ± SD]). Measures were obtained during three experimental conditions: (i) FAT-EEVID, involving acute fatiguing exercise performed on each assessment occasion plus a single episode of eccentric exercise performed on the first occasion and after the fatigue trial; (ii) FAT, involving the fatiguing exercise only and; (iii) CON consisting of no exercise. Assessments were performed prior to (pre) and at lh, 24h, 48h, 72h, and 168h relative to the eccentric exercise. Repeated-measures ANOVAs showed that muscle damage within the FAT-EEVID condition elicited reductions of up to 38%, 24%) and 65%> in volitional peak force, electromechanical delay and rate of force development compared to baseline and controls, respectively (F[io, 80] = 2.3 to 4.6; p to 30.7%>) following acute fatigue (Fp; i6] = 4.3 to 9.1; p ; Fp, iq = 3.9; p <0.05). The safeguarding of evoked muscle activation capability despite compromised volitional performance might reveal aspects of capabilities for emergency and protective responses during episodes of fatigue and antecedent muscle damaging exercise

    The earth's climate at the end of the century

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    Local climate is dependent on the global climate. Here, a global picture on climate change is presented using predictions from the EC-Earth simulations for the end of the century. The results indicate a general rise in annual mean temperature everywhere: 2-4 degrees (global average), 1-6 degrees (over Europe) and 1-4 degrees (Ireland). Changes in precipitation are more varied: large increases (>100%) at high northern latitudes and in the equatorial Pacific but decreases of more than 50% over the subtropics; winters in Europe are predicted to be up to 20% wetter and summers up to 20% drier. Changes in extremes are also presented in this chapter

    Anomalous increase in nematic-isotropic transition temperature in dimer molecules induced by magnetic field

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    We have determined the nematic-isotropic transition temperature as a function of applied magnetic field in three different thermotropic liquid crystalline dimers. These molecules are comprised of two rigid calamitic moieties joined end to end by flexible spacers with odd numbers of methylene groups. They show an unprecedented magnetic field enhancement of nematic order in that the transition temperature is increased by up to 15K when subjected to 22T magnetic field. The increase is conjectured to be caused by a magnetic field-induced decrease of the average bend angle in the aliphatic spacers connecting the rigid mesogenic units of the dimers

    Does My Stigma Look Big in This? Considering the acceptability and desirability in the inclusive design of technology products

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    This paper examines the relationship between stigmatic effects of design of technology products for the older and disabled and contextualizes this within wider social themes such as the functional, social, medical and technology models of disability. Inclusive design approaches are identified as unbiased methods for designing for the wider population that may accommodate the needs and desires of people with impairments, therefore reducing ’aesthetic stigma’. Two case studies illustrate stigmatic and nonstigmatic designs
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