• The Korea Journal of Herbology
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• v.25 no.1
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• pp.45-54
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• 2010

Objectives : The purpose of this study is to determine the impurity tolerance of Zanthoxylum Peel. Methods : Compare with medicinal Herb Books and the Pharmacopoeia of 6 nations. Results : Current Pharmacopoeia show different Zanthoxylum Peel's Purity, such as 2.0% of seeds and fruit stalk, etc. in North Korea, 2% of seeds in Vietnam, totally 3% in China. On the other hand, Korea and Japan set the total number 26.0% including the specific numbers such as 20.0% of seeds, 5.0% of fruit stalk, 1.0% of the other foreign matter. This Zanthoxylum Peel's Purity, 26.0%, is too high compared to that of other medical matters specified by The Korean Pharmacopoeia Ninth Edition. When The Japanese Pharmacopoeia Sixth Edition firstly set the Zanthoxylum Peel's Purity, the herbal name was Fructus. However, since the part for medical usage in origin is well-ripen pericarp, not seed, the permissible level, 30.0%, is supposed to be simple error range, 3.0%. Conclusions : As a result, I think bills concerning the Zanthoxylum Peel's Purity should be revised to the total number 3.0% or specifically set the level 2.0% of seeds, 1.0% of fruit stalk, twig and so on.

• Journal of Electrochemical Science and Technology
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• v.3 no.3
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• pp.123-134
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• 2012

The electrochemical performance of positive pole grids of lead-acid batteries made of Pb-0.08%Ca-1.1%Sn alloys without and with 0.1 wt% of each of Cu, As or Sb and with 0.1 wt% of Cu, As and Sb combined was investigated by electrochemical methods in 4.0 M $H_2SO_4$. The corrodibility of alloys under open-circuit conditions and constant current charging of the positive pole, the positive pole gassing and the self-discharge of the charged positive pole were studied. All impurities (Cu, As, Sb) were found to decrease the corrosion resistance, $R_{corr}$ after 1/2 hour corrosion, but after 24 hours an improvement in $R_{corr}$ was recorded for Sb containing alloy and the alloy with the three impurities combined. While an individual impurity was found to enhance oxygen evolution reaction, the impurities combined significantly inhibition this reaction and the related water loss problem was improved. Impedance results were found helpful in identification of the species involved in the charging/discharging and the self-discharge of the positive pole. Impurities individually or combined were found to increase the self-discharge during polarization (33-68%), where Sb containing alloy was the worst and impurities combined alloy was the least. The corrosion of the positive pole grid in the constant current charging was found to increase in the presence of impurities by 5-10%. Under open-circuit, the self-discharge of the charged positive grids was found to increase significantly (92-212%) in the presence of impurities, with Sb-containing alloy was the worst. The important result of the study is that the harmful effect of the studied impurities combined was not additive but sometimes lesser than any individual impurity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.3
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• pp.139-143
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• 2017

N-type crystalline silicon solar cells have high metal impurity tolerance and higher minority carrier lifetime that increases conversion efficiency. However, junction quality between the boron diffused layer and the n-type substrate is more important for increased efficiency. In this paper, the current status and prospects for boron diffused layers in N-type crystalline silicon solar cell applications are described. Boron diffused layer formation methods (thermal diffusion and co-diffusion using $a-SiO_X:B$), boron rich layer (BRL) and boron silicate glass (BSG) reactions, and analysis of the effects to improve junction characteristics are discussed. In-situ oxidation is performed to remove the boron rich layer. The oxidation process after diffusion shows a lower B-O peak than before the Oxidation process was changed into $SiO_2$ phase by FTIR and BRL. The $a-SiO_X:B$ layer is deposited by PECVD using $SiH_4$, $B_2H_6$, $H_2$, $CO_2$ gases in N-type wafer and annealed by thermal tube furnace for performing the P+ layer. MCLT (minority carrier lifetime) is improved by increasing $SiH_4$ and $B_2H_6$. When $a-SiO_X:B$ is removed, the Si-O peak decreases and the B-H peak declines a little, but MCLT is improved by hydrogen passivated inactive boron atoms. In this paper, we focused on the boron emitter for N-type crystalline solar cells.