Relationship Between Particles Volume Fraction Distribution and Electrical Properties in Rotational Liquid

Author(s):  
Yuya Akimoto ◽  
Fumiya Nagae ◽  
Kazuya Okawa ◽  
Yoshiyuki Iso ◽  
Noriaki Ichijo ◽  
...  

A wireless electrical resistance detector has been developed to measure the real-time particle volume fraction in a centrifuge for controlling a rotational velocity and particle supply rate. The purpose of this study is development of real-time particle concentration measurement technique in centrifuges because a technique for measuring the particle concentration in the centrifuges has not existed yet. The wireless electrical resistance detector was attached around a centrifuge for real centrifuge measurement experiment. This experimental centrifuge had electrodes which were covered with dielectric poly methyl methacrylate to avoid conductivity around the electrodes. The wireless electrical resistance detector was lightweight because the centrifuge condition is very severe because the rotational velocity was 3790rpm and gravity was 2000G. At first, sodium chloride solution was put in the centrifuge for the reaction stabilization of the wireless electrical resistance detector. Next, slurry of sodium chloride solution and acrylic particles with 50μm was continuously supplied in centrifuge for 10 minutes. As a result, the measured voltage was increased because the slurry was piled up in the vicinity of centrifuge inner wall. The measured resistance was increased with the lapse of time. The measured resistance coincides with an anticipated tendency of resistance. A change of particle volume fractions was measured in the centrifuge by the wireless electrical resistance detector.

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Vahid Pourzarghan ◽  
Bahman Fazeli-Nasab

AbstractThe most important inhibitors used in bronze disease are BTA and AMT. While these inhibitors control corrosion, they are toxic and cancerous. In this study, the acacia fruit extract (200 ppm to 1800 ppm) was used to the prevention of corrosion inhibition of bronze alloy in corrosive sodium chloride solution 0.5 M, for 4 weeks consecutively. The Bronze alloy used in this research, was made based on the same percentage as the ancient alloys (Cu-10Sn). IE% was used to obtain the inhibitory efficiency percentage and Rp can be calculated from the resistance of polarization. SEM–EDX was used to evaluate the surfaces of alloy as well as inhibitory. The experiment was conducted in split plot design in time based on the RCD in four replications. ANOVA was performed and comparison of means square using Duncan's multiple range test at one percent probability level. The highest rate of corrosion inhibition (93.5%) was obtained at a concentration of 1800 ppm with an increase in the concentration of the extract, corrosion inhibition also increased, i.e., more bronze was prevented from burning. Also, the highest corrosion inhibitory activity of Acacia extract (79.66) was in the second week and with increasing duration, this effect has decreased. EDX analysis of the control sample matrix showed that the amount of chlorine was 8.47%wt, while in the presence of corrosive sodium chloride solution, after 4 weeks, the amount of chlorine detected was 3.20%wt. According to the morphology (needle and rhombus) of these corrosion products based on the SEM images, it can be said, they are the type of atacamite and paratacamite. They have caused bronze disease in historical bronze works. The green inhibitor of Acacia fruit aqueous extract can play an effective role in inhibiting corrosion of bronze, but at higher concentrations, it became fungal, which can reduce the role of Acacia fruit aqueous extract and even ineffective. To get better performance of green inhibitors, more tests need to be done to improve and optimize.


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