A novel method to promote selective oxidation of Ni-Cr alloys: Surface spreading α-Al2O3 nanoparticles

2021 ◽  
pp. 109717
Author(s):  
Yun Xie ◽  
Yuanchao Huang ◽  
Yihang Li ◽  
Xiao Peng
2018 ◽  
Vol 29 (9) ◽  
pp. 7372-7387 ◽  
Author(s):  
Jie Wu ◽  
Songbai Xue ◽  
Jingwen Wang ◽  
Mingfang Wu ◽  
Jianhao Wang

2019 ◽  
Vol 33 (3) ◽  
pp. 675-682
Author(s):  
M. Hernández-Wolpez ◽  
P. R. Gallart-Tauler ◽  
I. García-Fornaris ◽  
E. Govea-Alcaide ◽  
E. Pérez-Tijerina ◽  
...  

2019 ◽  
Vol 5 (1) ◽  
pp. 580-583 ◽  
Author(s):  
Vijaya P. Dhawale . ◽  
Datta J. Late . ◽  
Satish D. Kulkarni .

Present study deals with the sol-gel synthesis and application of α-Al2O3 nanoparticles (alumina) to decolorize the azo anionic dye methyl orange (MO). α-Al2O3 nanoparticles were successfully synthesized using aluminium oxide, 25% ammonia and polyvinyl alcohol (PVA) were used as low cost raw materials. The properties of synthesized nanoparticles were investigated by using UV-visible spectroscopy, XRD, FTIR, SEM, EDAX, Raman spectroscopy and TEM. From UV–visible spectra, band gap was calculated and it was found to be 3.31 eV. Average crystal size of α-Al2O3 nanoparticles from XRD peaks found to be 25 nm having rhombohedral structure. FTIR spectra reveals that functional groups (O-Al-O) are present. SEM image shows distribution pattern of α-Al2O3 nanoparticles. Chemical composition of α-Al2O3 nanoparticles was confirmed from EDAX spectroscopy measurement. Raman spectra showed crystalline nature of α-Al2O3 nanoparticles. The effect of concentration and pH of dye, dosage of nano adsorbent and contact time were studied. The systematic study shows that, successful color removal of methyl orange dye up to 54% in three hours contact time of pH 4. Hence α-Al2O3 nanoparticles can be used for dye removal from waste water. Industrialization of this technique will be cost effective way to decolorize the textile dye present in water system.


2017 ◽  
Vol 37 (13) ◽  
pp. 4005-4013 ◽  
Author(s):  
Wenbin Cao ◽  
Xuan Mao ◽  
Yuan Yuan ◽  
Lu Li ◽  
Libin Zhao ◽  
...  

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Jayant Singh ◽  
Deepak Kumar ◽  
N. Tandon

Performance of grease lubricated point contact under elastohydrodynamics lubrication (EHL) regime is critical in many engineering applications. The present work deals with the evaluation of rheological, film forming characteristics and elastic recovery of newly developed nanocomposite greases. The nanocomposite greases are formulated by dispersing different nano-additives to bare grease (BG). The nano-additives include reduced graphene oxide (rGO) nanosheets, CaCO3 and α-Al2O3 nanoparticles. The microstructure evaluation of the nano-additives and different greases is done using high-resolution transmission electron microscopy (HRTEM). Estimation of the rheological parameters (storage and loss moduli) is done using rotational rheometer. The film forming behavior is recorded using elastohydrodynamic (EHD) rig for range of speed at different temperatures and constant load. The results indicate that change in microstructure due to nano-additive incorporation improves the responses of different greases. Based on rheological response, CaCO3 doped grease seems better but rGO doped grease is able to bear high shear stresses. Further, based on film forming characteristics and reflow or recovery behavior, rGO doped grease is better. The rGO-based grease registers approximately 90% elastic recovery followed by 75% for CaCO3-based grease, 65% for BG and 10% for α-Al2O3-doped grease.


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