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Seismic behavior of full-scale square concrete filled steel tubular columns under high and varied axial compressions

  • Phan, Hao D.;Lin, Ker-Chun
    • Earthquakes and Structures
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    • v.18 no.6
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    • pp.677-689
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    • 2020
  • A building structural system of moment resisting frame (MRF) with concrete filled steel tubular (CFST) columns and wide flange H beams, is one of the most conveniently constructed structural systems. However, there were few studies on evaluating seismic performance of full-scale CFST columns under high axial compression. In addition, some existing famous design codes propose various limits of width-to-thickness ratio (B/t) for steel tubes of the ductile CFST composite members. This study was intended to investigate the seismic behavior of CFST columns under high axial load compression. Four full-scale square CFST column specimens with a B/t of 42 were carried out that were subjected to horizontal cyclic-reversal loads combined with constantly light, medium and high axial loads and with a linearly varied axial load, respectively. Test results revealed that shear strength and deformation capacity of the columns significantly decreased when the axial compression exceeded 0.35 times the nominal compression strength of a CFST column, P0. It was obvious that the higher the axial compression, the lower both the shear strength and deformation capacities were, and the earlier and faster the shear strength degradation occurred. It was found as well that higher axial compressions resulted in larger initial lateral stiffness and faster degradation of post-yield lateral stiffness. Meanwhile, the lower axial compressions led to better energy dissipation capacities with larger cumulative energy. Moreover, the study implied that under axial compressions greater than 0.35P0, the CFST column specimens with B/t limits recommended by AISC 360 (2016), ACI 318 (2014), AIJ (2008) and EC4 (2004) codes do not provide ultimate interstory drift ratio of more than 3% radian, and only the limit in ACI 318 (2014) code satisfies this requirement when axial compression does not exceed 0.35P0.

Vacuum Ultraviolet Photolysis of Ethyl Bromide at 104.8-106.7 nm

  • Kim, Hong-Lae;Yoo, Hee-Soo;Jung, Kyung-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.2 no.2
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    • pp.71-75
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    • 1981
  • Vacuum ultraviolet photolysis of ethyl bromide was studied at 104.8-106.7 nm (11.4-11.6 eV) in the pressure range of 0.2-18.6 torr at $25^{\circ}$ using an argon resonance lamp with and without additives, i.e., NO and He. Since the ionization potential of $CH_3CH_2Br$ is lower than the photon energy, the competitive processes between the photoionization and the photodecomposition were also investigated. The observations indicated that 50% of absorbed light leads to the former process and the rest to the latter one. In the absence of NO the principal reaction products for the latter process were found to be $CH_4, C_2H_2, C_2H_4, C_2H_6, and C_3H_8$. The product quantum yields of these reaction products showed two strikingly different phenomena with an increase in reactant pressure. The major products, $C_2H_4$ and $C_2H_6$, showed positive effects with pressure whereas the effects on minor products were negative in both cases, i.e., He and reactant pressures. Addition of NO completely suppresses the formation of all products except $C_2H_4$ and reduces the $C_2H_4$ quantum yield. These observations are interpreted in view of existence of two different electronically excited states. The initial formation of short-lived Rydberg transition state undergoes HBr molecular elimination and this state can across over by collisional induction to a second excited state which decomposes exclusively by carbon-bromine bond fission. The estimated lifetime of the initial excited state was ${\sim}4{\times}10^{-10}$ sec. The extinction coefficient for $CH_3CH_2Br$ at 104.8-106.7 nm and $25{\circ}$ was determined to be ${varepsilon} = (1/PL)ln(I_0/I_t) = 2061{\pm}160atm^{-1}cm6{-1}$ with 95% confidence level.

Breeding of Orange Rose "Peach Pudding" with Good Color and Shape (화형, 화색이 우수한 오렌지색 절화용 스탠다드 장미 "피치푸딩" 육성)

  • Kim, Won-Hee;Kim, Seung-Tae;Huh, Kun-Yang;Lee, Eun-Kyung;Park, Pil-Man;Kim, Young-Jin
    • Korean Journal of Breeding Science
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    • v.41 no.1
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    • pp.40-43
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    • 2009
  • A new standard rose cultivar "Peach Pudding" was bred from the cross between deep red standard cultivar 'Red Sandra' and light pink standard cultivar 'Dolores' at the National Horticulture Research Institute. The cross was made in 2000 and "Peach Pudding" was finally selected in 2006 after investigating characteristics for three years from 2002 to 2006. 'Peach Pudding', a pink standard cultivar has good flower shape and fashionable flower color. The major characteristics of this cultivar are 113.1 stems/$m^2$/year in yield, 60.6 cm in length of cut flower, 8.7 cm in flower diameter, 38.6 in petal number, and 12.8 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cultivar, 'New Miracle'.

Effect of Cultivation Type and Shading on the Growth Characteristics of Lilium Oriental Hybrids Grown for Seed Bulbs in Highland in Summer (하계 고랭지에서 종구 생산시 재배형태와 차광에 따른 오리엔탈나리의 생육 특성)

  • Cho, Woo Sug;Park, Yoo Gyeong;Jeong, Byoung Ryong
    • FLOWER RESEARCH JOURNAL
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    • v.19 no.1
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    • pp.1-7
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    • 2011
  • This study was carried out to establish a production system of cut flowers and bulbs of oriental hybrid lilies in highland in summer. In study, effect of cultivation type and shading was examined. The cultivation types used in the bulb production experiments were greenhouses with no cover, greenhouses with net screen (net screen house), and greenhouses with EVA roof cover and net screen sides (rain shelter house). Net screen and rain shelter houses had either 0 or 30% shading. Cultivation type had significant effect and shading had a minor effect on bulb production. The greatest yield and quality of produced bulbs were obtained in the rain shelter house with 30% shading. From the results of this study, it is concluded that dispersed production of high quality cut lily flowers and bulbs could be achieved during the summer in highland.

Effect of High Voltage Pulsed Electric Fields on Extraction of Purple Sweet Potato Pigment (자색 고구마 색소의 추출에 미치는 고전압 펄스 전기장의 영향)

  • Shin, Jung-Kue;Shin, Hae-Hun
    • Food Science and Preservation
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    • v.14 no.2
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    • pp.165-169
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    • 2007
  • High voltage pulsed electric fields (PEF) is a promising technology for the nonthermal extraction of effective components from biological materials. Plant cells were ruptured with PEF at ambient or refrigerated temperature for a short treatment time of second or microsecond. Treatments of coarsely ground purple sweet potato (PSP) with PEF(30 kV/cm, 500 Hz) resulted in maximum extraction yield of 65% as compared with 45-50% for control. An increase in electric field strength (from 10kV/cm to 35kV/cm) and frequency (from 100Hz to 500Hz) resulted in increased amount of extracted pigments, but treatment time is not affected on pigment extraction. Starch granules were not detected and large intracellular spaces were visible between the cells on light and scanning election microscopy of PEF treated PSP. This result suggests that PEF have potential to use on extraction of pigments from plant cells.

Fertility and Characteristics of Mulberry fruits on Daejappong and Garmbacppong (Morus Spp.) (대자뽕과 감백뽕의임성 및 오디의 과실적 특성)

  • 박광준;성규병;이용기
    • Journal of Sericultural and Entomological Science
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    • v.43 no.2
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    • pp.93-98
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    • 2001
  • Major characteristics have been studied on Daejappong which is autotetraploid brooded for mulberry fruit and Garmbacppong selected from the wild mulberry of Turkey. The number of chromosomes of Daejappong was 2n=56 recornized tetraploid, and that of Gambacppong was 2n=42 as a triploid. The percentage of seed formation, sank seed and germination of Daejappong were 48.2%,32.7%,90.0% respectively, on the other hand these of Carmbacppong were very low level as 41.0%, 1.9%,7.0% respectively. On the single fruit (sorosis) weight, Daejappong was large fruit as 4.39 g with light purple color, and Garmbacppong was medium fruit as 3.26 g with milk white color. Sugar contents (Brix %) and total acidities of Daejappong and Garmbacppong were 14.2%,0.45%, and 19.3%,0.15% respectively. Maturities of 2 cultivars were late and mulberry fruit yield of Daejappong was high and that of Garmbacppong was medium yielding.

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Breeding of Medium Standard Rose, 'Honey Lemon' with White Color and Good Vase Life (절화수명이 긴 백색 중형 스탠다드 장미 'Honey Lemon' 육성)

  • Kim, Seung-Tae;Kim, Won-Hee;Lee, Eun-Kyung;Lee, Su-Young;Huh, Kun-Yang
    • Korean Journal of Breeding Science
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    • v.42 no.3
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    • pp.284-287
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    • 2010
  • A new standard rose cv. 'Honey Lemon' was bred by the cross between white standard cv. 'Escimo' and light pink standard cv. 'Medeo' at the National Institute of Horticultural Research Institute. The cross was made in 1999 and 'Honey Lemon' was finally selected in 2003 after investigating characteristics for three years from 2001 to 2003. 'Honey Lemon', a white standard cultivar grows vigorously and has good flower shape. The major characteristics of this cultivar are $248.0stems/m^2/year$ in yield, 53.0 cm in length of cut flower, 8.0 cm in flower diameter, 17.0 in petal number, and 16.9 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cv., 'Tineke'. (Registration number: 1151).

Case Study: Cost-effective Weed Patch Detection by Multi-Spectral Camera Mounted on Unmanned Aerial Vehicle in the Buckwheat Field

  • Kim, Dong-Wook;Kim, Yoonha;Kim, Kyung-Hwan;Kim, Hak-Jin;Chung, Yong Suk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.64 no.2
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    • pp.159-164
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    • 2019
  • Weed control is a crucial practice not only in organic farming, but also in modern agriculture because it can lead to loss in crop yield. In general, weed is distributed in patches heterogeneously in the field. These patches vary in size, shape, and density. Thus, it would be efficient if chemicals are sprayed on these patches rather than spraying uniformly in the field, which can pollute the environment and be cost prohibitive. In this sense, weed detection could be beneficial for sustainable agriculture. Studies have been conducted to detect weed patches in the field using remote sensing technologies, which can be classified into a method using image segmentation based on morphology and a method with vegetative indices based on the wavelength of light. In this study, the latter methodology has been used to detect the weed patches. As a result, it was found that the vegetative indices were easier to operate as it did not need any sophisticated algorithm for differentiating weeds from crop and soil as compared to the former method. Consequently, we demonstrated that the current method of using vegetative index is accurate enough to detect weed patches, and will be useful for farmers to control weeds with minimal use of chemicals and in a more precise manner.

A Case Study on Smart Livestock with Improved Productivity after Information and Communications Technologies Introduction

  • Kim, Gok Mi
    • International Journal of Advanced Culture Technology
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    • v.9 no.1
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    • pp.177-182
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    • 2021
  • The fourth industrial revolution based on information and communication technology (ICT) becomes the center of society, and the overall industrial structure is also changing significantly. ICT refers to the hardware of information devices and the software technologies required for the operation and information management of these devices, and any means of collecting, producing, processing, preserving, communicating and utilizing them. ICT is integrated into industries and services or combined with new technologies in various fields such as robotics and nanotechnology to connect all products and services to the network. The development of ICT, which continuously creates new products and services, has spread to all sectors of the industry, affecting not only daily life but also the livestock sector recently. In agriculture, ICT technology can reduce production costs by efficiently managing labor and energy because it can improve quality and yield based on data on environmental and growth information such as temperature, humidity, light and soil. In particular, smart livestock is considered suitable for achieving livestock management goals because it can reduce labor force and improve productivity by remotely and automatically managing accurate information necessary for raising and breeding livestock with ICT devices. The purpose of this study is to propose the need for ICT technology by comparing farm productivity before and after ICT is introduced. The method of the study is to compare the productivity before and after the introduction of ICT in Korean beef farms, pig farms, and poultry farms. The effectiveness of the study proved the excellence of ICT technology through the production results before ICT introduction and the productivity improvement case of livestock farms that efficiently operated manpower management and reduced labor force after ICT introduction. The conclusion of this paper is to present the need for smart livestock through ICT adoption through case study results.

Demonstration of the Effectiveness of Monte Carlo-Based Data Sets with the Simplified Approach for Shielding Design of a Laboratory with the Therapeutic Level Proton Beam

  • Lai, Bo-Lun;Chang, Szu-Li;Sheu, Rong-Jiun
    • Journal of Radiation Protection and Research
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    • v.47 no.1
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    • pp.50-57
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    • 2022
  • Background: There are several proton therapy facilities in operation or planned in Taiwan, and these facilities are anticipated to not only treat cancer but also provide beam services to the industry or academia. The simplified approach based on the Monte Carlo-based data sets (source terms and attenuation lengths) with the point-source line-of-sight approximation is friendly in the design stage of the proton therapy facilities because it is intuitive and easy to use. The purpose of this study is to expand the Monte Carlo-based data sets to allow the simplified approach to cover the application of proton beams more widely. Materials and Methods: In this work, the MCNP6 Monte Carlo code was used in three simulations to achieve the purpose, including the neutron yield calculation, Monte Carlo-based data sets generation, and dose assessment in simple cases to demonstrate the effectiveness of the generated data sets. Results and Discussion: The consistent comparison of the simplified approach and Monte Carlo simulation results show the effectiveness and advantage of applying the data set to a quick shielding design and conservative dose assessment for proton therapy facilities. Conclusion: This study has expanded the existing Monte Carlo-based data set to allow the simplified approach method to be used for dose assessment or shielding design for beam services in proton therapy facilities. It should be noted that the default model of the MCNP6 is no longer the Bertini model but the CEM (cascade-exciton model), therefore, the results of the simplified approach will be more conservative when it was used to do the double confirmation of the final shielding design.