• Journal of the Korea Concrete Institute
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• v.19 no.6
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• pp.685-692
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• 2007

When the shear force governs the response of an RC element, as in the case of a low-rise shear wall, the effect of shear on the element's response is thought to be responsible for the 'pinching effect' in the hysteretic loops. However, it was recently shown that this undesirable pinching effect can be eliminated in the hysteretic load-deformation curves of a shear-dominant element if the steel grid orientation is properly aligned in the direction of the applied principal stresses. In this paper, the presence and absence of the pinching mechanism in the hysteretic loops of the shear stress-strain curves of RC elements was explained rationally using a compatibility aided truss model. The analytical results indicate that the pinching effect of the RC elements is strongly related to the direction of the steel arrangement. The area of the energy dissertation does not increase proportionally to the difference between the direction of the principal compressive stress and the direction of the steel arrangement.

• Korean Journal of Plant Resources
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• v.34 no.2
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• pp.166-171
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• 2021

This research was conducted to investigate the effect of foliar application of 6-benzylaminopurine (BA), sprayed weeks after pinching (SWP), on ornamental usage of Veronica longifolia L, which is native to Korea. Foliar application of 0, 500, 1,000, and 2,000 mg/L BA on 10 cm long V. longifolia L. plant was evaluated at 0, 7, and 14 days after pinching for growth and flowering. The maximum result of multiple shooting was seen in the 2,000 mg/L BA at 1 week after pinching, and almost all the treatments showed dwarf growth in V. longifolia L. The number of days to flowering was delayed by BA treatments. Moreover, the length and the number of flowers decreased with high concentrations of BA. Thus, foliar application of BA via pinching technique can improve the ornamental usage of V. longifolia L. by controlling the plant type.

• FLOWER RESEARCH JOURNAL
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• v.17 no.2
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• pp.88-92
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• 2009

This experiment was conducted to find out the effects of pinching on shoot growth, flowering and covering of Lonicera sempervirens growth in containers. 180 cm high pinching of plants increased shoot length compared to 60 cm low pinching and decreased lateral shoot numbers, but there was no difference in branch numbers by the pinching methods. Covering rates of the pergola were 85% with 60 cm low pinching, 74% with 120 cm middle pinching, and 62% with 180 cm high pinching. The pinched plants continued to flower from the middle of May to the middle of September. The first flowering time was in the middle of May in low pinching and in the early of June in middle and high pinching. The lower pinching height and the earlier pinching time induced earlier flowering time, and the peak flowering of pinched plants was in mid-August. To cover over 85% of the pergola screen with 3.0 m wide and 2.2 m high, two plants per 1 m needed to grow and to pinch at 60 cm height.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.304-308
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• 1990

This study was conducted to increase the yield of sesame on the undeveloped upland by pinching and application of minor nutrients which were magnesium. boron and zinc. The effect of phinching to yield at 20 days after germination was 17%. and pinching effect at 50 days after germination with minor nutrients was 46% compared to non-treatments. These effect were considered as increasing the number of capsule per plant. number of node per main stem. and 1,000 grains weight. Simultaneously, the nutrients (Mg. B and Zn) were recognized to promote remarkably the yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.457-462
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• 2004

Lodging is one of the most serious problems in soybean cultivation. Therefore, improved cultural methods to reduce lodging as well as to increase photosynthetic ability should be mostly desirable to increase soybean production. The test variety was 'Hwangkeumkong' which was pinched at V7 stage. The greatest difference in canopy height between rows was shown when every other row was pinched, which also recorded the most effective reduction in lodging. The 9th leaf of soybean plants in non-pinching rows of alternative non-pinching and pinching plot showed the highest photosynthetic ability due to the greatest difference in canopy height. Although leaf area index was higher in pinched rows in average after 17 August, alternative pinching of every other row recorded the highest LAI on 5 September. Alternative pinching of every other row resulted $2\~14\%$ higher yield than non-pinching or complete pinching due to the increases of number of grains in the upper part of main stem and average grain weight of non-pinching rows and in alternative pinching.

• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.21-25
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• 2004

This experiment was carried out to investigate the effect of apex removal at different leaf ages on the growth and yield of broccoli in pinching cultivation. Apex was pinched when 2, 3 or 4 true leaves were spread during nursery bed, and non-pinching was conventional method. The plant height was not different among treatments but the fresh weight was decreased as the pinching days were delayed. The numbers of leaves and lateral shoots were increased compared to those of non-pinching by pinching. Days to central budding were shortended by 3 days when pinched at 2 true leaves spreading stage than those of non-pinching. Central (1st) head weight was heaviest when pinched at the time of 2 true leaves spreading (157g). Total head weight was heaviest when pinched at the time of 2 true leaves spreading (378g), and lowest at 4 true leaves spreading stage (196g). Marketable yields were increased by 48% when pinched at the time of 2 true leaves spreading (1,754kg) as compared with those of non-pinching (1,184kg) and lowest when pinched at the time of 4 true leaves spreading (820kg). Also, first harvest was shortended by 6 days by pinching at 2 true leaves spreading stage.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10b
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• pp.72-74
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• 2000

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.2
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• pp.245-256
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• 2000

A moment-curvature relationship to simulate the behavior of reinforced concrete beam under cyclic loading is introduced. Unlike previous moment-curvature models and the layered section approach, the proposed model takes into consideration the bond-slip effect by using monotonic moment-curvature relationship constructed on the basis of the bond-slip relation and corresponding equilibrium equation at each nodal point. In addition, the use of curved unloading and reloading branches inferred from the stress-strain relation of steel gives more exact numerical result. The advantages of the proposed model, comparing to layered section approach, may be on the reduction in calculation time and memory space in case of its application to large structures. The modification of the moment-curvature relation to reflect the fixed-end rotation and pinching effect is also introduced. Finally, correlation studies between analytical results and experimental studies are conducted to establish the validity of the proposed model.

• 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.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.4
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• pp.353-367
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• 2003

This paper describes the extension of the numerical model, which was developed to simulate the nonlinear behavior of reinforced concrete (RC) structures subjected to monotonic in plane shear and introduced in the companion paper, to simulate effectively the behavior of RE structures under cyclic loadings. While maintaining all the basic assumptions adopted in defining the constitutive relations of concrete under monotonic loadings, a hysteretic stress strain relation of concrete, which across the tension compression region, is defined. In addition, unlike previous simplified stress strain relations, curved unloading and reloading branches inferred from the stress strain relation of steel considering the Bauschinger effect we used. The modifications of the stress strain relation of steel are also introduced to reflect pinching effect depending on the shear span ratio and an average stress distribution in a cracked RC element. Finally, correlation studies between analytical results and experimental studies are conducted to establish the validity of the proposed model.