scholarly journals Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization Effects

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1253
Author(s):  
Silvia Casans Berga ◽  
Rafael Garcia-Gil ◽  
A. Edith Navarro Anton ◽  
Alfredo Rosado-Muñoz

A novel method for measuring the electrical resistance in wood is presented. It is based on applying an Alternating Current (AC) to two electrodes rammed into the wood. The method reduces the transient time for value stabilization. In case of Direct Current (DC) resistance measurement methods, typically used in wood measurement, an initial transient exists, invalidating the measured value during an initial transient period. This measurement method uses an electronic circuit based on a relaxation oscillator where the wood automatically sets the oscillation frequency depending on its electrical resistance. Compared to other AC methods, this circuit greatly simplifies the measurement process, not requiring any previous analysis for wood AC frequency estimation. Experimental results for four different wood species showed that, in all cases, the transient response of the measured wood resistance is improved when compared to the DC resistance method, reducing the stabilization time from 10–12 min in DC measurements to almost zero for the novel measurement method. The deviation between the initial wood resistance measurement and the stable value resulted in a range between 0.2% and 5% with the proposed method, while a range between 6% and 10% was obtained when using the DC method. Moreover, the proposed circuit is able to detect changes in wood resistance produced by small variations in temperature and environmental relative humidity during continuous long term measurements. For repeatability analysis, it was verified that similar ambient conditions of temperature and relative humidity (variations lower than 1 °C and 1%, respectively) in different moments provided variations lower than 1.5%. The method can also be applied to other fiber materials affectd by polarization effects when an electrical current is applied into them.

2016 ◽  
Vol 14 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Masafumi Uematsu ◽  
Yasser Helmy Mohamed ◽  
Naoko Onizuka ◽  
Ryotaro Ueki ◽  
Daisuke Inoue ◽  
...  

2002 ◽  
Vol 16 (01n02) ◽  
pp. 137-143
Author(s):  
P. PENG ◽  
Z. H. JIN ◽  
K. LU ◽  
Z. Q. HU

The spinodal decomposition processes in the rapidly solidified Cu-10aT%Co alloy aged at several temperatures have been investigated using an in-situ electrical resistance measurement method combining a slowly scanning x-ray diffraction technique. Based on the Cahn-Hilliard theory, the time-dependences of amplification factor of the concentration modulation R(β) at different aging temperatures were calculated, and the Co atomic concentration of Co-rich region and Co-depleted region in the aged alloy were also deduced. The results showed that the evolution of composition modulation in microstructure in Cu-10aT%Co alloy can be monitored and characterized by an in-situ electrical resistance measurement method if only the degree of phase decomposition at some aging temperature and aging time had been previously deteced.


2020 ◽  
Vol 67 (12) ◽  
pp. 5454-5459
Author(s):  
Xuan Li ◽  
Shiwei Feng ◽  
Chang Liu ◽  
Yamin Zhang ◽  
Kun Bai ◽  
...  

2015 ◽  
Vol 3 (38) ◽  
pp. 19294-19298 ◽  
Author(s):  
Xichang Bao ◽  
Qianqian Zhu ◽  
Meng Qiu ◽  
Ailing Yang ◽  
Yujin Wang ◽  
...  

High-quality CH3NH3PbI3 perovskite films were directly prepared on simple treated ITO glass in air under a relative humidity of lower than 30%.


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