4,411 research outputs found
A study on the shunt effect in resistance spot welding
No full textOne of the important factors affecting the weld quality of practical resistance spot welding is the shunt effect, which deteriorates weld quality due to the shunt current that flows through neighboring welds. Although some experimental studies for compensation for its effect have been presented, no effort has been made to establish an analytical model that can predict the effect of shunt mechanism on the weld quality. This paper presents an analytical model by which the shunt effect upon the nugget growing behavior can be analyzed. The voltage field and temperature distribution in the weldment are computed by the proposed three-dimensional finite difference numerical model. Experimental verification of the calculated results was also performed and discussed in detail. The comparison of both results shows that the proposed thermal-electric model can predict the shut effect fairly well
Anterior open bite treated by non-surgical and non-extraction orthodontic therapy – case report
No full text
The production of imperatorin from angelica dahurica var Formosana by cell suspension culture
No full textBai-Zhi (Angelica dahurica) is a valuable medicinal plant used as source of curatives for headache and skin disease in China. The purpose of this study was to establish cell suspension culture as alternative source of imperatorin, the major active ingredient of the species. The formulation of MS basic salts, modified by increasing the phosphate concentration to 2 mM and using an ammonium to nitrate ratio of 2:1, provided the best imperatorin production. Glucose was a better carbon source than sucrose and fructose. The addition of 0.5-1 mg/l of BA to the culture medium increased imperatorin yield, whereas auxins produced only negative effects. Supplementing the medium with 20g/l of the adsorbent Amberlite XAD-7 increased imperatorin yield 140-fold
Four Months Under Arms
No full textA book written by H.S. Nelson about his experiences fighting in the second Riel Rebellion
Efficient transformation of Klebsiella oxytoca by electroporation
No full textA protocol for the transformation of Klebsiella oxytoca by electroporation was developed. Preparation of competent cells at early exponential phase was most critical to obtain a high transformation efficiency. The highest efficiency of 1.6 × 10 transformants per μg DNA (pBR 322) could be obtained by electroporation of K. oxytoca cells prepared at the OD600 of 0.2 with 1.25 μg DNA at the filed strength of 2.5 kV, the parallel resistance of 200 Ω and capacitance of 25μF
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