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排序方式: 共有871条查询结果,搜索用时 15 毫秒
91.
Tervahattu H Kupiainen KJ Räisänen M Mäkelä T Hillamo R 《Journal of hazardous materials》2006,132(1):39-46
Road dust forms an important component of airborne particulate matter in urban areas. In many winter cities the use of anti-skid aggregates and studded tires enhance the generation of mineral particles. The abrasion particles dominate the PM10 during springtime when the material deposited in snow is resuspended. This paper summarizes the results from three test series performed in a test facility to assess the factors that affect the generation of abrasion components of road dust. Concentrations, mass size distribution and composition of the particles were studied. Over 90% of the particles were aluminosilicates from either anti-skid or asphalt concrete aggregates. Mineral particles were observed mainly in the PM10 fraction, the fine fraction being 12% and submicron size being 6% of PM10 mass. The PM10 concentrations increased as a function of the amount of anti-skid aggregate dispersed. The use of anti-skid aggregate increased substantially the amount of PM10 originated from the asphalt concrete. It was concluded that anti-skid aggregate grains contribute to pavement wear. The particle size distribution of the anti-skid aggregates had great impact on PM10 emissions which were additionally enhanced by studded tires, modal composition, and texture of anti-skid aggregates. The results emphasize the interaction of tires, anti-skid aggregate, and asphalt concrete pavement in the production of dust emissions. They all must be taken into account when measures to reduce road dust are considered. The winter maintenance and springtime cleaning must be performed properly with methods which are efficient in reducing PM10 dust. 相似文献
92.
TuijaKuula Timo Sutela 《造纸信息》2008,(12):5-9
造纸行业日趋承受着节水、节能以及环保的压力。也就是说,造纸企业必须寻找新技术,将注意力转移到生产中的整个水质和高效的原料回收系统上。 相似文献
93.
There is a demand for a clean label of ice cream in the food industry. To meet this requirement, alternative surfactants and hydrocolloids without an additive number have to be found. Here, a caseinate hydrolysate with improved interfacial properties was investigated as such an additive. Replacing only the surfactant resulted in ice cream characteristics, comparable to using a commercial emulsifier (INS 472b). Thus, a clean labeling of the surfactant using this hydrolysate is possible. By contrast, replacing the hydrocolloid additionally led to an unfavorable ice cream texture and stability. 相似文献
94.
Yli-Tuomi T Lanki T Hoek G Brunekreef B Pekkanen J 《Environmental science & technology》2008,42(12):4440-4446
Daily PM2.5 samples were repeatedly collected (1-8 times) in the homes of elderly nonsmoking individuals with coronary heart disease in Amsterdam, The Netherlands (33 individuals) and Helsinki, Finland (44 individuals). Sources of indoor PM2.5 were evaluated using a two-way multilinear engine model. Because the indoor elemental data lacked a traffic marker, separation of traffic related PM was attempted by combining the indoor data with fixed site outdoor data that also contained NO. Six outdoor sources, including long-range transport (LRT), urban mixture, oil combustion, traffic, sea-salt, and soil were identified, and three indoor sources were resolved: resuspension, potassium-rich and copper-rich sources. The average contribution of the indoor factors was 6% (1.1 microg m(-3)) and 22% (2.4 microg m(-3)) in Amsterdam and Helsinki, respectively. The highest longitudinal correlations between source-specific outdoor and indoor PM2.5 concentrations were found for LRT and urban mixture; the median R was above 0.6 for most sources. The longitudinal correlations were lower in Helsinki than in Amsterdam. Indoor-generated PM2.5 was not related to ambient concentrations. We conclude that using outdoor and indoor data together improved the source apportionment of indoor PM2.5. The results support the use of fixed site outdoor measurements in epidemiological time-series studies on outdoor air pollution. 相似文献
95.
Van der Meulen R Camu N Van Vooren T Heymans C De Vuyst L 《International journal of food microbiology》2008,124(1):27-33
The carbohydrate and aromatic amino acid metabolism of several species related to the human colon was investigated into more detail. Therefore, in vitro fermentations were performed, with different carbohydrate sources, during which several aromatic amino acids were added to the fermentation medium. Shifts in end-product formation in response to the available nutrients were observed for all strains tested. The major part of amino acid degradation occurred after depletion of the carbohydrates. Moreover, it was shown that Bifidobacterium strains are capable of degrading aromatic amino acids in the absence of carbohydrates. The excretion of certain intermediates of the aromatic amino acid metabolism was observed for a strain of Clostridium clostridioforme, after which they were metabolized again during a later stage of fermentation. This implies that cross-feeding on degradation products of aromatic amino acids, albeit within the same species, can occur in the human colon. 相似文献
96.
A novel procedure for the evaluation of liquid water flow during the drying of wood is described. The method is based on the movement of a fluorescent dye solution in liquid water. The addition of the dye solution produced a clear trace inside the wood, the length and direction of which were directly related to the flow of liquid water. A comparison of the results obtained with image analysis using UV illumination and measurement of the reflectance spectrum of wood showed that image analysis is appropriate and accurate enough for the determination of the trace of the dye solution. The trace of the dye solution can be determined from the images of the cross sectional samples of wood in all three main directions. 相似文献
97.
Polyphenol and vitamin C contents in European commercial blackcurrant juice products 总被引:1,自引:0,他引:1
Pirjo H. Mattila Jarkko Hellström Gordon McDougall Gary Dobson Juha-Matti Pihlava Timo Tiirikka Derek Stewart Reijo Karjalainen 《Food chemistry》2011
Vitamin C and polyphenol contents (anthocyanins, proanthocyanidins, phenolic acids and flavonols) were analysed in commercial blackcurrant juice products purchased from various European countries (Finland, Poland, Germany, United Kingdom) using HPLC methods. The aim was to study variation between countries, as well as evaluate the intake of polyphenols from commercial juices. There was significant variation in the contents of polyphenols and vitamin C between countries. Expressed as the ready-to-drink beverages, German, Polish, Finnish and British products averaged anthocyanin contents of 38, 32, 12 and 7.5 mg/2.5 dl, proanthocyanidin contents of 27, 24, 10 and 1.2 mg/2.5 dl, flavonol contents of 16, 15, 5.2 & 1.9 mg/2.5 dl and phenolic acid contents of 12, 8.9, 3.7 and 1.5 mg/2.5 dl, respectively. The mean vitamin C content was highest in British (70 mg/2.5 dl) and lowest in Finnish products (15 mg/2.5 dl). The intake of polyphenols from German and Polish ready-to-drink beverages was clearly higher than that from Finnish, and especially, British beverages. 相似文献
98.
Timo M. Buetler Hélia Latado Estelle Leclerc Bernd Weigle Alexandra Baumeyer Claus W. Heizmann Gabriele Scholz 《Molecular nutrition & food research》2011,55(2):291-299
Scope: Advanced glycation endproducts (AGEs) are suspected to stimulate inflammatory signaling pathways in target tissues via activation of the receptor for AGEs. Endotoxins are generally recognized as potential contamination of AGE preparations and stimulate biological actions that are very similar as or identical to those induced by AGEs. Methods and results: In our study, we used glycolaldehyde‐modified β‐lactoglobulin preparations as model AGEs and employed two methods to remove endotoxin using either affinity columns or extraction with Triton X‐114 (TX‐114). Affinity column‐purified AGEs retained their ability to stimulate inflammatory signaling as measured by mRNA expression of inflammatory cytokines in the human lung epithelial cell line Beas2b. However, glycolaldehyde‐modified AGEs purified by extraction with TX‐114 did not show any stimulation of mRNA expression of inflammatory cytokines. The presence of a cell stimulating endotoxin‐like activity was demonstrated in the detergent phase after extraction with TX‐114, thus indicating that not AGEs but a lipophilic contamination was responsible for the stimulation of inflammatory signaling. Conclusion: Our results demonstrate that glycolaldehyde‐modified AGEs are unable to induce inflammatory signaling in receptor for AGE‐expressing cells. The observed cell‐activating activity can be ascribed to an endotoxin‐like lipophilic contamination present in AGE preparations and affinity column purification was insufficient to remove this contamination. 相似文献
99.
100.
文章介绍了搭载人类自体干细胞的纤维支架技术及其在软组织再生中的应用优势。选用藻酸盐材料结合人体干细胞搭载关键技术制成的纤维支架,同时具有促进血管再生和触发成脂分化的能力。 相似文献