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Wind energy is a fast-growing and promising renewable energy source. The investment costs of wind turbines have decreased over the years, making wind energy economically competitive to conventionally produced electricity. Size scaling in the form of a power law, experience curves and progress rates are used to estimate the cost development of ever-larger turbines. In life cycle assessment, scaling and progress rates are seldom applied to estimate the environmental impacts of wind energy. This study quantifies whether the trend toward larger turbines affects the environmental profile of the generated electricity. Previously published life cycle inventories were combined with an engineering-based scaling approach as well as European wind power statistics. The results showed that the larger the turbine is, the greener the electricity becomes. This effect was caused by pure size effects of the turbine (micro level) as well as learning and experience with the technology over time (macro level). The environmental progress rate was 86%, indicating that for every cumulative production doubling, the global warming potential per kWh was reduced by 14%. The parameters, hub height and rotor diameter were identified as Environmental Key Performance Indicators that can be used to estimate the environmental impacts for a generic turbine.  相似文献   

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f 1.0%, and the chitosan having mol. wt. of 1 000 showed better antibacterial activity against gram-negative bacteria than gram-positive ones.chitosan; antibacterial activity; anti-crease property; finishing  相似文献   

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The available literature on tobacco endgames tends to be limited to discussing means, targets and difficulties. This article offers additional ideas on the key elements of endgame strategies and the circumstances in which these are likely to be adopted and implemented. We suggest such strategies will include explicit plans, will define the nature of `the end of tobacco use/sale' and have target dates within 20 years. The likely circumstances for endgame strategy development include low (probably under 15% adult smoking) prevalence and/or rapid prevalence reductions, wide support and strong political leadership. Even with some or all these circumstances, opposition from business, internal government forces and international factors may influence results.  相似文献   

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This study is designed to identify the damage of the broken-holes on woollen fabric. We can use optical microscope, SEM and chemical method to identify the cause of the broken-hole. Under the optical microscope, if the damaged fibers appear a lunate gap or prominence on the cross section, it can belong to moth damage, if there are broken filaments on the cross section of damaged fibers, it can be regarded as mechanical damage, if the fibers stick together,it can be attributed to heat damage. Under the SEM, if the cross section is smooth, it is mechanical damage, otherwise it is moth damage. Under the treatment of saturated bromine, the moth damaged fiber bubbles at 92 seconds, while the mechanical damaged fiber bubbles at 37 seconds.  相似文献   

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The microbial community composition and dynamics during the production of a French soft, red-smear cheese were investigated. The colonization efficiency of the smearing inoculum was followed, and the parts played by the inoculum used and the resident microflora were tentatively estimated. Single-strand conformation polymorphism analysis (SSCP) was applied to 2 productions of a soft, red-smear cheese produced by the same dairy plant at 4-mo intervals. Microbial composition of the different cheese samples analyzed was found to be reproducible from one production to another. However, the composition of the surface flora of both cheeses at the end of the ripening did not reflect the composition of the smearing inoculum used, qualitatively as well as quantitatively. These results were confirmed by those obtained when assessing the microbial composition of the culturable flora by the spread plate technique. The inoculum used by the industry had low resiliency potentialities against colonization of cheeses by resident organisms. Therefore, fitness and colonization potential of smearing inocula should be carefully assessed by the industry before use. The use of Arthrobacter strains as part of the smearing inoculum should be evaluated.  相似文献   

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Epidemiological studies suggested an association between obesity and sleep disturbances. Obstructive sleep apnea is the most prevalent type of obesity-related sleep disorder that lead to an increased risk for numerous chronic health conditions. In addition the increased visceral adipose tissue might be responsible for the secretion of inflammatory cytokines that could contribute to alter the sleep-wake rhythm. Unhealthy food characterized by high consumption of fat and carbohydrate seems to negatively influence the quality of sleep while diet rich of fiber is associated to more restorative and deeper sleep. Although obesity could cause through several pathogenetic mechanisms an alteration of sleep, it has been reported that subjects suffering from sleep disorders are more prone to develop obesity. Experimental laboratory studies have demonstrated that decreasing either the amount or quality of sleep increase the risk of developing obesity. Experimental sleep restriction also causes physiological, hormonal and food behavioral changes that promote a positive energy balance and a compensatory disproportionate increase in food intake, decrease in physical activity, and weight gain. Thus, the aim of this review is to provide observational evidence on the association of obesity with sleep disturbances and viceversa with emphasis on possible pathophysiological mechanisms (hormonal and metabolic) that link these two pathological conditions.  相似文献   

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The use of natural resources for the production of nanostructured cellulosic films of high quality could reduce pollution and raw material costs for cellulose industry. This work provides innovative information about the use of Amazonian species not explored in studies involving the production of nanostructured films, as well as the evaluation of important characteristics that may be decisive for the destination of the product. The aim of this study was to modify Schizolobium parahyba var. amazonicum (paricá) waste fibers through alkaline (NaOH) and bleaching (NaClO2) treatments for cellulose nanofibrils (CNFs) production and evaluate the characteristics of the nanofibrils and the surface as well as the mechanical resistance of the films obtained. The alkaline treatment was carried out with sodium hydroxide (5% NaOH solution (w/v); 2 h), while the bleaching was performed using sodium chlorite and glacial acetic acid (1.5 g NaClO2; 10 drops of glacial acetic acid; 1 h). The treatments were performed in sequence, producing nanofibrils after alkaline treatment and after bleaching. Lignin content did not change with the alkaline treatment, but it significantly decreased with bleaching (from 26.1 to 6.8%). Hemicelluloses content decreased with the sequence of treatments. FTIR results showed that the mechanical defibrillation caused disruption of the fiber bonds. The temperature of thermal degradation observed in DTG analysis increased from the natural fibers (243 °C) to alkaline?+?bleached fibers (255 °C). The defibrillation process led to higher thermal stability of the alkaline?+?bleached nanofibrils in comparison to fibers. Moreover, films were prepared from the obtained CNFs and evaluated by the mechanical properties and surface contact angle. The mechanical properties showed values of 6.93?±?0.18 GPa for modulus of elasticity (MOE) for the films produced from material which was submitted to the bleaching treatment. The results highlighted a more hydrophobic surface of the film produced with the CNFs generated from the bleached fibers. The results of mechanical properties showed the superiority of the films produced from the alkaline?+?bleached fibers.  相似文献   

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The anti-inflammatory effects of extracts of the seaweed Sargassum macrocarpum (SME) in bone marrow-derived macrophages (BMDMs) and dendritic cells (BMDCs) were investigated. Primary BMDMs and BMDCs were used for cytokine production and western blot analysis. SME (0–50 μg/mL) pre-treatment resulted in a strong inhibitory effect against interleukin (IL)-12 p40, IL-6, and tumor necrosis factor (TNF)-α production in CpG-stimulated BMDMs and BMDCs. SME pre-treatment caused a strong inhibitory effect against NF-κB activation, as evaluated using degradation of IκBα and the NF-κB reporter gene assay. SME has significant anti-inflammatory properties and warrants further study regarding potential use as a medicinal food.  相似文献   

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李树霞张春明 《丝绸》2022,(12):146-155
作为明代特色典型纹样之一,四合如意云纹的艺术特征独具时代特色。文章以明代织物、画像中的四合如意云纹为研究对象,基于实物样本图片,结合相关史料,梳理总结其发展脉络,从单元造型、基本组织形式、色彩表现和面料工艺四方面对其进行解析,揭示其形式在明代的发展演变过程。研究表明:四合如意云纹从明代初期到明代晚期单元造型由结构松散、自由简洁逐渐丰满圆润、结构稳定;组织形式由单一严谨逐渐丰富多样;色彩由单调浅淡、贵贱有等逐渐华丽多姿、违礼逾制;面料工艺由用料有等、技法单一逐渐竞相奢侈、精巧别致。  相似文献   

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Flame-proofing the Arctic?   总被引:1,自引:0,他引:1  
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This article ethnographically examines the symbolic importance of seafood and its ritualized consumption in demarcating ideals of “authenticity” and “intangible heritage” in the famed Italian-American Christmas Eve feast, La Vigilia. The Vigilia is a rite of intensification intended to revitalize a community in a climate of schism and “acculturation,” and a rite of incorporation for integrating American spouses into the family's heritage. While continually transforming as participants entertain new culinary understandings, cultivate “Americanized” tastes, and integrate spouses into the ritual, the practices of selecting, preparing, and ritually consuming the Vigilia's food serve to maintain traditional gender roles, reinforce ethnic bonds through commensality, and denote “authenticity” through taste preferences. Suggesting that authenticity is conveyed not through a particular object or its taste, but rather through intangible processes, the author argues that the Vigilia feast becomes a central means of negotiating the antithetical pressures of maintaining tradition and embracing social transformation.  相似文献   

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The objective of this work is to optimize the arrangement of the fibers to reduce damage to the fiber matrix interface of a composite material. The results obtained by the genetic algorithm based on the volume fraction of reinforcement show a good agreement between numerical simulation and the actual behavior of both materials T300/914 and PEEK/APC2, however, it would be interesting to see the effect of thermal stress on the optimization of the arrangement by the molecular dynamics method.  相似文献   

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Abstract

The Poisson’s ratio is a fundamental and inherent property of the materials in their reaction to loading. Determining the correct value of the Poisson’s ratio leads to more accurate predictions of the mechanical behavior of the material, especially in employing mechanical or numerical finite element modeling methods. In this study, seven different types of medium and coarse yarn were digitally filmed in seven sections from three various angles while tensile strength testing. Then, longitudinal and transverse strains and consequently, momentary deformation index and Poisson’s ratio of the yarns were calculated. Significance level of the mean Poisson’ ratio was also determined at different angles and sections using statistical comparison test. The results showed that the transverse strain has a convergent state at the end of the test and the start of the yarn breaking occurs at the convergence point. Additionally, in upper sections of yarn near to the movable jaw of the strength tester, the amount of the longitudinal strain increases which leads to reduce in momentary deformation index and Poisson’s ratio of the yarn. Moreover, a sectional mode to measure the Poisson's ratio was presented.  相似文献   

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