排序方式: 共有54条查询结果,搜索用时 15 毫秒
1.
Mustafa Mortas Fehmi Yazici Muhammet Dervisoğlu 《International Journal of Food Properties》2017,20(8):1866-1875
The effect of brewing process on 5-hydroxymethylfurfural, 2-furylmethylketone, and 2-furoic acid levels of traditionally prepared and instant Turkish coffee samples containing different amounts of table sugar (0, 2, 4, or 8 g in 20 mL of coffee) were analyzed by high pressure liquid chromatography with diode array detector. The highest change at the levels of furfurals was observed in sample of traditional and instant Turkish coffee named T4 and S4 both of containing 8 g of sugar, respectively. The results showed that 5-hydroxymethylfurfural, 2-furylmethylketone, and 2-furoic acid concentrations in both traditionally prepared and instant Turkish coffee samples increased with increasing sugar concentration. The brewing method and sugar concentration had a significant effect on furfural contents of Turkish coffee (p < 0.05). Daily intakes of furfurals for Turkish population were calculated as 8.14–13.54 and 9.36–10.25 µg kg?1 body weight for traditionally prepared and instant Turkish coffee samples, respectively, and daily intakes of furfurals were lower than the acceptable daily intake value of 0.5 mg kg?1 body weight. 相似文献
2.
Meryem Koruyucu Fehmi Saltan Gökhan Kök Hakan Akat Yeşim Salman 《Iranian Polymer Journal》2016,25(5):455-463
The present study describes the synthesis and characterizations of polymerizable vinyl sugars. Glucose, mannose, galactose and fructose are abundant and sustainable natural compounds. As it is not possible to make many derivatives of sugars without using protective groups, first of all, diacetone derivatives [diacetone-d-glucose (1), diacetone-d-mannose (2), diacetone-d-galactose (3) and diacetone-d-fructose (4)] were synthesized according to the literature as starting compounds. The remaining free hydroxyl groups on C-3 (diacetone glucose), C-6 (diacetone galactose), C-1 (diacetone fructose) and C-1 (diacetone mannose), were reacted with epichlorohydrin (1-chloro-2,3-epoxypropane) to produce then “-O-(2′,3′-epoxypropane-1′-yl)” ether derivatives (5, 6, 7, and 8) which are epoxy sugars in the basic medium. Next, the epoxy rings of the ethers (5, 6, 7, and 8) were opened with methacrylic acid in DMF to produce new sugar based methacrylates (9, 10, 11, and 12). Finally, free radical polymerization of these sugar based methacrylate monomers was performed, producing related polymers (13, 14, 15 and 16). The polymerizations were carried out using AIBN as an initiator at 70 °C in DMF. All the products were characterized by FTIR, 1HNMR and 13CNMR techniques. Thermal properties of all polymers were investigated by TG, DTG and DSC. The data obtained has suggested that thermal stability of the synthesized polymers has changed with the structure of the sugar and increase in molecular weight. 相似文献
3.
Muhammet Dervisoglu Fehmi Yazici Oguz Aydemir 《European Food Research and Technology》2005,221(3-4):466-470
The effect of soy protein concentrate (0, 1.5, 3, and 4.5%) on the physical, chemical, and sensory properties of strawberry flavored (0, 0.01 and 0.02%) ice cream samples was examined. All samples were analyzed for pH, titratable acidity, total solids, nitrogen, fat, ash, overrun, viscosity, meltdown, Hunter L-, a-, b- values, flavor, body and texture, and appearance. Substituting soy protein concentrate (SPC) in ice cream formula for non-fat dry milk (NFDM) positively influenced the nitrogen content, viscosity values, and melting and appearance properties of the ice cream samples while overrun values and flavor scores were negatively affected. SPC could be incorporated into the ice cream formula in the range of 1.5–3% devoid of significantly diminishing the physical, chemical, and sensory properties. 相似文献
4.
5.
The shape memory effect (SME) does not only concern the macroscopic structure. It concerns also the polymer structure at morphological, macromolecular, and molecular scales. This effect may depend on different physicochemical properties like morphology heterogeneity, chain rigidity, steric hindrance, chain polarity, free volume, cross-linking or entanglement density, molecular shape and weight, and so on. Hence, finding the relationship between the SME and these properties is very important. This can help to obtain the knowledge about the phenomenon origin and mechanism. One of the basic polymer properties, which can have direct SME, may be the molecular weight (Mw ). The question here is: If the Mw of a shape memory polymer (SMP) changes, for different reasons like degradation, what will be the effect of this change on its SME. In order to answer to this question, the investigation is focused on an SMP blend of 40% poly(ɛ-caprolactone) (PCL) and 60% styrene-butadiene-styrene (SBS). Then, enzymatic hydrolysis is performed on this blend to change its Mw . It is shown that this change is only related to the variation in the Mw of PCL. After that, different samples with a distinct average Mw are prepared and characterized by various experimental methods. Shape memory tests are performed on these blends, and the recovery rate (Rr ) for each of them is determined. It is found that when Mw of PCL decreases, its degree of crystallinity, its glass transition, and its melting temperatures, corresponding to the PCL phase, increase. However, the elongation at break of the blend declines with the reduction in Mw . The tests show that the alteration in the blend's Mw influences its SME. Indeed, Rr of the (PCL/SBS) mixture drops with the decrease in Mw of PCL. 相似文献
6.
Qiujian Lv Yuanyuan Qiao Yi Zhang Fehmi Ben Abdesslem Wenhui Lin Jie Yang 《Wireless Personal Communications》2018,101(3):1469-1498
With the growth of the Mobile Internet, people have become active in both the online and offline worlds. Investigating the relationships between users’ online and offline behaviors is critical for personalization and content caching, as well as improving urban planning. Although some studies have measured the spatial properties of online social relationships, there have been few in-depth investigations of the relationships between users’ online content browsing behaviors and their real-life locations. This paper provides the first insight into the geospatial properties of online content browsing behaviors from the perspectives of both geographical regions and individual users. We first analyze the online browsing patterns across geographical regions. Then, a multilayer-network-based model is presented to discover how inter-user distances affect the distributions of users with similar online browsing interests. Drawing upon results from a comprehensive study of users of three popular online content services in a metropolitan city in China, we achieve a broad understanding of the general and specific geospatial properties of users’ various preferences. Specifically, users with similar online browsing interests exhibit, to a large extent, strong geographic correlations, and different services exhibit distinct geospatial properties in terms of their usage patterns. The results of this work can potentially be exploited to improve a vast number of applications. 相似文献
7.
In the present study, the usability of the pumice of the Isparta-Karakaya those categorized in the light aggregate class, have been examined in terms of stabilization material in the subbase considering volumetric unit weight. 相似文献
8.
In this study, the response surface methodology (RSM) has been applied to optimize the operating conditions of direct methanol fuel cell (DMFC). A quadratic model was developed through RSM in terms of related independent variable to describe the current as the response. The input data required in this model has been obtained experimentally. For this purpose, an experimental set up for testing of direct methanol fuel cell has been established to investigate the effects of temperature and flow rate parameters on the cell performance. Two different analyses for operating conditions were performed applying the response surface method to obtain the maximum power. These analyses were based on the unlimited and minimum methanol consumptions. Methanol flow rate, oxygen flow rate, methanol temperature, humidification temperature and cell temperature were the main parameters considered that they were varied between 2 and 50 ml/min, 100-1000 ml/min, 30-70 °C, 30 70 °C and 30-80 °C in the analyses respectively. The maximum current under the unlimited and minimum methanol consumptions was found as 1230 mA and 582 mA based on the contour plots and variance analysis. 相似文献
9.
10.
Fehmi S. Yasin Licong Peng Rina Takagi Naoya Kanazawa Shinichiro Seki Yoshinori Tokura Xiuzhen Yu 《Advanced materials (Deerfield Beach, Fla.)》2020,32(46):2004206
Much scientific capital has been directed toward exotic magnetic spin textures called Bloch lines, that is, Néel-type line boundaries within domain walls, because their geometry promises high-density magnetic storage. While predicted to arise in high-anisotropy magnets, bulk soft magnets, and thin films with in-plane magnetization, Bloch lines also constitute magnetic antiskyrmions, that is, topological antiparticles of skyrmions. Most domain walls occur as Bloch-type or Néel-type, in which the magnetization rotates parallel or perpendicular to the domain wall across its profile, respectively. The Bloch lines’ Néel-type rotation and their minute size make them difficult to directly measure. This work utilizes differential phase contrast (DPC) scanning transmission electron microscopy (STEM) to measure the in-plane magnetization of Bloch lines within antiskyrmions emergent in a non-centrosymmetric Heusler magnet with D2d symmetry, Mn1.4Pt0.9Pd0.1Sn, in addition to Bloch-type skyrmions in an FeGe magnet with B20-type crystal structure to benchmark the DPC technique. Both in-focus measurement and identification of Bloch lines at the antiskyrmion's corners are provided. 相似文献