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71.
Chai Jaturapitakkul Jatuphon Tangpagasit Sawang Songrnue Kraiwood Kiattikomol 《Canadian Metallurgical Quarterly》2011,18(2)
The river sand, which is a non-pozzolanic material, was ground into 3 different particle sizes. Portland cement type I was replaced by the ground river sands at 10wt%-40wt% of binder to cast mortar. Compressive strengths of mortar were investigated and the filler effect of different fine particles of sand on the compressive strength of mortar was evaluated. The results show that the compressive strength of mortar contributed from the filler effect of smaller particles is higher than that of the coarser ones. The difference in compressive strength of mortar tends to be greater as the difference in ground river sand fineness increases. The results also suggest that ASTM C618 specification is not practically suitable for specifying pozzolan in concrete since the strength activity index of mortar containing ground river sand (high crystalline phase) with 33.8wt% of particles retained on a 45-μm sieve can pass the strength requirement. 相似文献
72.
Sandra Smiljanic Cyril Messaraa Virginie Lafon-Kolb Nina Hrapovic Nahid Amini Christina Osterlund Lene Visdal-Johnsen 《International journal of molecular sciences》2022,23(20)
The Scandinavian region is home to a unique biome with endemic plant species. The aim of this study was to explore this natural diversity and identify plant extracts providing positive skin barrier effects. Six plant extracts were identified as starting material. Following biochemical screening, two candidates outperformed the rest: Betula alba (BA) and Empetrum nigrum (EN). Quantitative PCR analysis showed that BA and EN upregulated barrier genes, when used individually and in combination. Betula alba increased AQP3 and OCLN protein expression, something niacinamide was incapable of. Additionally, the skin barrier was strengthened, evidenced by inhibition of KLK5 and hyaluronidase and showed strong antioxidant and anti-inflammatory activity through DPPH and COX2 inhibition, respectively. A first split-face clinical study was conducted using the combination of extracts versus placebo. There was a significantly better skin restructuring effect and corneocyte cohesion on the side treated with combined extracts. A second split-face clinical study assessed the combined extracts versus 3% niacinamide. Significant variations in skin hydration and TEWL were observed in favor of the extract treated side. In conclusion, we identified a natural alternative to niacinamide for improving skin barrier health, in Scandinavian plant extracts, which yield strong performance, but at a lower concentration. 相似文献
73.
74.
水泥胶凝材料水化进程及力学特性研究 总被引:1,自引:0,他引:1
首先简述了热分析的测定原理及其在水泥化学研究中的应用;利用热重方法分析了水泥净浆的水化进程变化规律,研究了不同水灰比的水泥净浆水化程度;并从理论上解释了不同水灰比的水泥净浆水化程度发展规律;而且,对水泥净浆水化过程中的抗压强度进行了测试,试验结果发现其变化趋势与水化程度变化趋势是完全一致的,这充分反映了微观结构与宏观性能之间的关系. 相似文献
75.
76.
利用稻壳灰、CFB脱硫灰、钢渣协同制备一种无熟料水硬性无机胶凝材料,可替代水泥用于岩土固化。为提高这种胶凝材料的活性及其他性能,研究经机械粉磨后胶凝材料的性能变化及其机理。结果表明:随着粉磨时间增加,胶凝材料的粒度分布曲线由多峰分布转变为单峰分布,标准稠度用水量减少,凝结时间缩短;水化诱导期的结束时间和第2放热峰出现时间明显提前,累积放热量增加;砂浆试件的早期抗压强度和自收缩显著增加;采用无熟料胶凝材料制备流态固化土,其初始流动扩展度随粉磨时间增加而增加,经时损失加快;机械粉磨对固化土的早期强度影响不显著,后期强度则呈现先增加后降低的趋势。采用该无熟料胶凝材料制备流态固化土,能满足一般回填工程的强度要求。 相似文献
77.
为了实现铜炉渣的废物利用,以碱激发方式为主研究铜炉渣制备矿用胶凝材料的可能性.选取生石灰、NaOH和早强剂组成的混合物作为复合激发剂,开展铜炉渣活性激发和充填材料制备试验,并采用X射线衍射和扫描电子显微镜对铜炉渣水化产物进行分析.试验结果表明,各激发剂对铜炉渣活性的影响顺序依次为生石灰 > 早强剂 > NaOH,在复合激发剂的作用下炉渣净浆试样的7和28 d强度分别可以达到1.5和3.0 MPa以上.铜炉渣尾砂充填料28 d强度为1.0 MPa,流动性良好,满足充填材料要求.铜炉渣早期水化产物主要有片状的Ca(OH)2和C-S-H凝胶,随着养护时间的增加,C-S-H凝胶Ca/Si比不断减小,水化产物结构更加致密.养护时间至28 d时,铜炉渣中活性成分基本反应完全. 相似文献
78.
Low resolution pulse nuclear magnetic resonance study of water equilibration in dried carrots 总被引:2,自引:0,他引:2
J. P. MONTEIRO MARQUES D. N. RUTLEDGE C. J. DUCAUZE 《International Journal of Food Science & Technology》1991,26(2):173-183
Samples taken during air drying of carrots were analysed after different equilibration times. Low resolution NMR measurements were made and the longitudinal ( T 1 ) and the transverse ( T 2 ) relaxation times calculated. Both T 1 and T 2 decreased with the equilibration time for water contents above 0.30 and 0.47 kg water kg-1 dry matter, respectively. The decrease in relaxation time increased with the water content. For the same water contents, grated carrots gave lower T 1 values and smaller T 1 decreases with equilibration time than 3-mm cubes. Low resolution NMR is a technique which is well suited to the monitoring of the tempering phases of industrial drying cycles. 相似文献
79.
Hani Hafeeza Halim Elfy Williams Dee Mohd Sabri Pak Dek Azizah Abdul Hamid Ahmad Ngalim Nazamid Saari 《International Journal of Food Properties》2018,21(1):2378-2389
The present work aimed to compare the main ergogenic attributes of two commercialized stages (young and mature) of coconut water (CW) obtained from four coconut varieties. The changes of electrolytes and sugars in CW upon maturation were quantified by inductively coupled plasma mass spectrophotometer and high-performance liquid chromatography, respectively. Based on the electrolyte profiling, potassium yielded the highest amount (ranging from 237.41 to 361.20 mg/100 mL) followed by sodium, magnesium, calcium, iron, manganese, copper, selenium, and zinc across all the maturity stages tested. For sugars, there were lower amounts of fructose and glucose, but a higher amount of sucrose with the maturation of the fruits. In conclusion, the amount of beneficial nutrients in the form of sugars and minerals was higher than that of young CW, and the ergogenic attributes of mature CW especially from MATAG variety (M-MATAG) were the best to be exploited further in the development of natural energy drinks. 相似文献
80.
高惨量粉煤灰混凝土水化进程的试验研究 总被引:11,自引:4,他引:7
高掺量粉煤灰混凝土早期二次水化较为缓慢,随后二次速度逐渐加快,激发剂能显著提高粉煤灰的活性,加速高掺量粉煤灰二次水化反应。通过掺加激发剂、减水剂和控制水胶比,高掺量粉煤灰混凝土是可以满足工程需要的。 相似文献