• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.268-272
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• 2005

This study was carried out to investigate the labor saving cultivation of C. auriculatum, which has much bigger root than local variety C. wilfordii, and tested three nonsupporting methods, i.e., untreated control, top pinching, and cutting of branch-top compared with I type stake. Top growth was more vigorous in staking cultivation than in nonsupporting cultivations. Among nonsupporting methods, main vine length and total length of main vines per plant were increased in order of untreated control > top pinching > cutting of branch-top, while the opposite is true to diameter of main vein. Number of leaves per plant was lower, but leaf length and leaf width were higher in cutting of branch-top than in other nonsupporting methods. Number of branched root and diameter of main root were bigger in cutting of branch-top and in staking cultivation, while length of main root and diameter of branched root were greater in staking cultivation and in top pinching than in other treatments. Although yield of marketable root per 10a was $17.9{\sim}22.6%$ lower, income was $8%{\sim}17%$ higher in nonsupporting methods than in staking cultivation by cost saving to staking installation. Among nonsupporting methods, yield of marketable root and income were 6% and 8% higher in cutting of branch-top than in untreated control, respectively.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.119-122
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• 2015

The experiment was carried out to examine the effect of pinching time on growth and marketable yield of okra in rain shielding vinyl houses. Okra (Abelmoschus esculentus L., 'Green sod') seedling was transplanted in May, 2013. Pinching times of okra were in each 30th, 45th, 60th day after transplanting of okra. Shoot branch and top fresh weight were significantly different between each pinching times. Top fresh weight were highest at 60th day pinching time after transplanting investigated, and were lowest at 30th day pinching time after transplanting. There was no significant difference in plant height and stem length among pinching times. According to pinching times, marketable yield and number of okra fruits were varied. Marketable yields were highest at 60th day after transplanting, whereas were lowest at 30th day after transplanting. Mineral concentrations of okra fruits were not significantly different among pinching times. Therefore pinching times 60th day after transplanting was effective to increase yield of okra fruit in rain shielding vinyl houses.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.393-400
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• 2009

In order to find out the feasibility of producing grafted red pepper (Capsicum annuum L.) seedlings with root-removed rootstocks, rooting response and subsequent seedling growth was also evaluated. Pinching the top of pepper seedlings for cutting significantly reduced the rooting of cuttings in 10 commercial hot pepper cultivars. Normal rooting was obtained from all commercial cultivars even though the rooting response varied considerably among cultivars. Poor rooting was observed in 'Gukbo' and 'Chungyang'. Rootone treatment significantly promoted rooting in all tested cultivars and the decrease of rooting response caused by pinching could be fully recovered by rootone treatment. Among the ten commercial rootstocks developed for hot pepper grafting, 'Tantan' showed the best rooting response followed by 'Konesian Hot' and 'Wonkwang 1'. Most of these rootstocks, however, showed higher rooting response as compared to the popular commercial cultivars, 'Manit', 'Chungyang', and 'Nokkwang'. Pasting of IBA at cut surface promoted the rooting of pepper cuttings, but the effect was not quite pronounced as compared to rootone treatment.

• Natural Product Sciences
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• v.22 no.1
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• pp.25-29
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• 2016

High-performance liquid chromatography was performed in order to analyze the changes in the flavonoid content (rutin, hyperin, afzelin, quercetin, and kaempferol) of Acanthopanax divaricatus and A. koreanum, in response to different cultivation methods (pinching height, planting time, and top dressing). The total flavonoid content of A. divaricatus and A. koreanum ranged from 0.201 to 0.690 mg/g with different pinching heights, 0.143 to 1.001 mg/g for different planting times, and 0.156 to 1.074 mg/g depending on the rate of fertilizer application. In both A. divaricatus and A. koreanum, the total flavonoid content in the upper section of the plant was greater than that in the lower section. These results demonstrate which cultivation methods maximize the flavonoid content of A. divaricatus and A. koreanum, and thus help to optimize flavonoid yields to improve production for nutraceutical, pharmaceutical, and cosmeceutical applications.

• Steel and Composite Structures
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• v.37 no.1
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• pp.15-26
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• 2020

The top-and-seat angles with double web angles are commonly used in the design of beam-to-column joints in Asian and North American countries. The seismic behavior analysis of these joints with large cross-section size of beam and column (often connected by four or more bolts) is a challenge due to the effects from the relatively larger size of stiffened angles and the composite action from the adjacent concrete slab. This paper presents an experimental investigation on the seismic performance of exterior composite beam-to-column joints with stiffened angles under cyclic loading. Four full-scale composite joints with different configuration (only one specimen contain top angle in concrete slab) were designed and tested. The joint specimens were designed by considering the effects of top angles, longitudinal reinforcement bars and arrangement of bolts. The behavior of the joints was carefully investigated, in terms of the failure modes, slippage, backbone curves, strength degradation, and energy dissipation abilities. It was found that the slippage between top-and-seat angles and beam flange, web angle and beam web led to a notable pinching effect, in addition, the ability of the energy dissipation was significantly reduced. The effect of anchored beams on the behavior of the joints was limited due to premature failure in concrete, the concrete slab that closes to the column flange and upper flange of beam plays an significant role when the joint subjected to the sagging moment. It is demonstrated that the ductility of the joints was significantly improved by the staggered bolts and welded longitudinal reinforcement bars.

• Journal of Korean Society of Steel Construction
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• v.30 no.1
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• pp.37-48
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• 2018

Cyclic loading tests for shear dominant hybrid steel link beams with circular web openings were performed to evaluate the seismic performance. Four half-scaled specimens with bolted connections were tested. The test parameter is a diameter of the web opening, i.e., shear strength ratio ($V_{pw}/V_p$) of the link beam and presence of top-seat angles. Using test results, adequate design shear strength of link beam was finally suggested. Test results showed that when the shear capacity is less than half of the plastic shear strength, seismic performance was improved due to mitigation of pinching under reversed cyclic inelastic deformations.

• Steel and Composite Structures
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• v.3 no.1
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• pp.47-64
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• 2003

In a nonlinear finite element study on the mechanical behavior of simple beam connections to continuous concrete-filled steel tube columns, two principally different connection types were analyzed: one with plates attached to the outside of the tube wall, relying on shear transfer, and one with an extended plate inserted through the steel section to ensure bearing on the concrete core. The load was applied partly at the connection within the column length and partly at the top, representing the load from upper stories of a multistory building. The primary focus was on the increased demand for load transfer to ensure composite action when concrete with higher compressive strength is used. The results obtained from the analyses showed that the design bond strength derived from push tests is very conservative, mainly due to the high frictional shear resistance offered by pinching and contraction effects caused by connection rotation. However, with higher concrete strength the demand for load transfer increases, and is hard to fulfill for higher loads when connections are attached only to the steel section. Instead, the connection should penetrate into the concrete core to distribute load to the concrete by direct bearing.