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排序方式: 共有9118条查询结果,搜索用时 78 毫秒
1.
Phuong-Anh Ngoc Doan Tzyi-Horng Tan Lee Fong Siow Beng Ti Tey Eng Seng Chan Teck-Kim Tang Nur Azwani Abdul Karim Eng-Tong Phuah Yee-Ying Lee 《Journal of the American Oil Chemists' Society》2021,98(6):609-620
Palm fatty acid distillate (PFAD) is a rich source of vitamin E. As compared to other vegetable oil, PFAD has higher tocotrienol (70–80%) over tocopherol content, which makes it a valuable source for vitamin E extraction. Current vitamin E extraction methods are not sustainable due to the intensive usage of chemical and high operational cost. Hence, the present study investigated for the first time using dry fractionation process as a green and economical pretreatment method for separating solid fraction (stearin) and liquid fraction (olein) in order to concentrate vitamin E from PFAD in olein fraction. We examined the dry fractionation conditions: crystallization ending temperature (36–44 °C), cooling rate (0.3 and 1.5°C min−1), stirring speed (20–125 rpm), and holding time (0–60 min) on the composition of unsaturated and saturated fatty acids as well as vitamin E content in liquid fraction (olein) and solid fraction (stearin) using gas chromatography and high performance liquid chromatography, respectively. In most of these conditions, vitamin E was ultimately higher in olein fraction as compared to stearin fraction, which is correlated with the high degree of unsaturation. Under a cooling rate of 0.3°C min−1, 90 rpm stirring speed, and ending crystallization of 38 °C, the highest vitamin E rich olein fraction was attained with 1479 ± 10.51 ppm in 50 g olein fraction as compared to 1366 ± 7.94 ppm in 500 g of unfractionated PFAD. 相似文献
2.
Cheng-Feng Yue Shi-Jei Huang Jhewn-Kuang Chen Hsien-Tsung Li Kam-Shau Chan 《Metals and Materials International》2018,24(2):307-313
The effects of an addition of 0–2 wt% Nd on thermal stability of 0–3 wt% Ca-containing modified AZ71 magnesium alloys was investigated. The ignition temperature was found to increase from that of AZ71, 574, to 825 °C with the addition of 0.5 wt% Ca and 1 wt% Nd. The ignition temperature was further increased to 1114 °C when 3 wt% Ca was added. The Ca- and Nd-added AZ71 was isothermally maintained at a temperature of 500 °C in air for 12 h. The MgO–CaO–Nd2O3 formed on the surface to improve the thermal stability of the AZ71–xCa–yNd alloys. While both the tensile strength and ductility decreased with the Ca concentration in the alloy, an addition of 1 wt% Nd was found able to alleviate the degradation effects of Ca on the tensile strength and ductility at 170 °C. Both solid solution formation and precipitation strengthening contributed to the increase in toughness. AZ71 containing 0.5–2 wt% Ca and 1 wt% Nd provides the optimum combination of ignition resistance and mechanical properties. 相似文献
3.
Chun Dong Hyun Rhim Geun Bae Youn Min Hye Deviana Deviana Lee Ji Eun Park Ji Chan Jeong Heondo 《Topics in Catalysis》2020,63(9-10):793-809
Topics in Catalysis - Fischer–Tropsch synthesis (FTS) is a promising way to produce clean liquid fuels and high value-added chemicals from low-value carbon-containing resources such as coal,... 相似文献
4.
Koay Seong Chun Chan Ming Yeng Chou Pui May Tshai Kim Yeow Ong Thai Kiat Cheah Kean How 《乙烯基与添加剂工艺杂志》2020,26(1):10-16
Chrysanthemum flower is among one of the highly sought after and widely planted flower crops, in particular for cultural and religious ceremonies. However, the chrysanthemum stem and stalk have little value and usually discard as by‐product waste from floristry. The objective of this research is to investigate the potential value of utilizing chrysanthemum stem and stalk as reinforcing fillers for thermoplastic composites. In this study, 2‐mm thick composite sheet containing predefined formulations of polylactic acid (PLA), chrysanthemum waste filler (CWF) ranging from 15 to 60 phr, and maleated polyethylene (MAPE) coupling agent up to 5 phr were prepared with the aid of Haake internal mixer and compression molding. The effect of MAPE loading on tensile, thermal, and morphological properties of PLA/CWF composites was investigated. The findings revealed that PLA/CWF composite attained improved tensile modulus compared to the neat PLA, and the tensile modulus increases with higher concentration of CWF. However, both tensile strength and elongation at break reduces with increase loading of CWF. Overall, PLA/CWF composites with MAPE shows better performance compared to those without MAPE, where an optimum strength of 21.8 MPa can be achieved with 60 phr CW and 3 phr MAPE. The measured tensile strength is comparable to alternatives natural fiber thermoplastic composites demonstrating its potential to be used in non‐structurally demanding application. J. VINYL ADDIT. TECHNOL., 26:10–16, 2020. © 2019 Society of Plastics Engineers 相似文献
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6.
Scientometrics - Although scientists, like many other professionals, aspire to fame and recognition, research in the emergent field of fame and celebrity has as yet neglected to explore their fame... 相似文献
7.
Wesley P. Chan Hiroto Mizohana Xiangyu Chen Yasuto Shiigi Yoshiyuki Yamanoue Masaki Nagatsuka Masayuki Inaba 《野外机器人技术杂志》2019,36(1):17-33
The use of field robots can greatly decrease the amount of time, effort, and associated risk compared to if human workers were to carryout certain tasks such as disaster response. However, transportability and reliability remain two main issues for most current robot systems. To address the issue of transportability, we have developed a lightweight modularizable platform named AeroArm. To address the issue of reliability, we utilize a multimodal sensing approach, combining the use of multiple sensors and sensor types, and the use of different detection algorithms, as well as active continuous closed‐loop feedback to accurately estimate the state of the robot with respect to the environment. We used Challenge 2 of the 2017 Mohammed Bin Zayed International Robotics Competition as an example outdoor manipulation task, demonstrating the capabilities of our robot system and approach in achieving reliable performance in the fields, and ranked fifth place internationally in the competition. 相似文献
8.
Guang Chen Li Liu Vadim V. Silberschmidt Changqing Liu Fengshun Wu Y. C. Chan 《Journal of Materials Science: Materials in Electronics》2018,29(7):5253-5263
In this study, 96.5Sn–3Ag–0.5Cu (SAC305) lead-free composite solder containing graphene nanosheets (GNS) decorated with Ni nanoparticles (Ni-GNS) was prepared using a powder metallurgy method. A lab-made set-up and a corresponding Cu/solder/Cu sample design for assessing thermo-migration (TM) was established. The feasibility of this setup for TM stressing using an infrared thermal imaging method was verified; a temperature gradient in a solder joint was observed at 1240 K/cm. Microstructural evolution and diffusion of Cu in both plain and composite solder joints were then studied under TM stressing conditions. Compared to unreinforced SAC305 solder, the process of diffusion of Cu atoms in the composite solder joint was significantly reduced. The interfacial intermetallic compounds (IMCs) present in the composite solder joint also provide a more stable morphology after the TM test for 600 h. Furthermore, during the TM test, the Ni-GNS reinforcement affects the formation, migration and distribution of Ni–Cu–Sn and Cu–Sn IMCs by influencing the dissolution rate of Cu atoms. 相似文献
9.
The onset of miscible viscous fingering in porous media was analyzed theoretically. The linear stability equations were derived in the self-similar domain, and solved through the modal and non-modal analyses. In the non-modal analysis, adjoint equations were derived using the Lagrangian multiplier technique. Through the non-modal analysis, we show that initially the system is unconditionally stable even in the unfavorable viscosity distribution, and there exists the most unstable initial disturbance. To relate the theoretical predictions with the experimental work, nonlinear direct numerical simulations were also conducted. The present stability condition explains the system more reasonably than the previous results based on the conventional quasi-steady state approximation. 相似文献
10.
Artificial Photosynthesis: Ni‐Nanocluster Modified Black TiO2 with Dual Active Sites for Selective Photocatalytic CO2 Reduction (Small 2/2018) 下载免费PDF全文