• 제목/요약/키워드: Center cut

검색결과 943건 처리시간 0.028초

In vitro Multiplication and Corm Production of Freesia hybrida 'Sunny Gold'

  • Jinjoo Bae;Jae-young Song;Woohyung Lee;Jung-ro Lee;Munsup Yoon
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2022년도 추계학술대회
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    • pp.62-62
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    • 2022
  • Freesia has been an important worldwide cut flower because of its fragrance, long vase life and the wide color range of the flower. The conventional propagation methods by seeds and corms have many disadvantages such as shorter inflorescences with fewer numbers of florets, a reduction in cut flower quality and the accumulation of plant viruses in corms by successive cultivation. Therefore, the conventional propagation systems in Freesia needs to be replaced with tissue cultures to overcome the disadvantages. This study explored an efficient multiplication protocol using the combination of plant growth regulators (PGRs) for developed cultivar 'Sunny Gold'. The combination between 6-benzylaminopurin (BA) and α-naphthalene acetic acid (NAA) did not produce new shoots but developed enlarged roots. BA only treatments and the combination between BA and kinetin treatments were effective on shoot multiplication. The highest average number of shoots was 5.3 in the presence of 3 mg/L BA and 0.5 mg/L kinetin. To produce corms and cormlets, proliferated shoots were subcultured on 1/2 Murashige and Skoog (MS) medium supplemented with 90 g/L sucrose, 1 g/L charcoal and 7 g/L plant agar and placed at 4℃ in the dark for 6 months. The small size of corms and comlets were produced. The average number of regenerated comlets was 2.75 per shoot. The results showed that shoot multiplication is more efficient than cormlet regeneration for in vitro freesia proliferation.

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절삭방향(切削方向)이 목재(木材)의 레이저절삭특성(切削特性)에 미치는 영향(影響) (Effects of Cutting Direction on the Laser Machining Characteristics of Wood)

  • 이형우
    • Journal of the Korean Wood Science and Technology
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    • 제24권4호
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    • pp.87-92
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    • 1996
  • When cutting 2.0cm-thick red oak and hard maple with an air-jet-assisted carbon-dioxide laser of 2kW output power, maximum feed speed at the point of full penetration of the beam decreased with increasing the angle between grain and cutting direction. Feed speed averaged 3.75 and 3.38 meters per minute for red oak and hard maple, respectively. Gray-level of laser-cut surfaces were analyzed by image analysis system. The highest gray level of laser-cut surface was obtained when red oak was cut parallel to grain by laser. Surface profiler was used to scan the sawn and laser-cut surfaces. Center line average roughnesses of laser-cut surfaces were higher than those of sawn surfaces. Scanning electron micrographs showed the cell walls which were melted by laser.

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Discrimination of Floral Scents and Metabolites in Cut Flowers of Peony (Paeonia lactiflora Pall.) Cultivars

  • Ahn, Myung Suk;Park, Pue Hee;Kwon, Young Nam;Mekapogu, Manjulatha;Kim, Suk Weon;Jie, Eun Yee;Jeong, Jae Ah;Park, Jong Taek;Kwon, Oh Keun
    • 한국자원식물학회지
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    • 제31권6호
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    • pp.641-651
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    • 2018
  • Floral scents and metabolites from cut flowers of 14 peony cultivars (Paeonia lactiflora Pall.) were analyzed to discriminate different cultivars and to compare the Korean cultivar with the other cut peonies imported to Korea using electronic nose (E-nose) and Fourier transform infrared (FT-IR) spectroscopy combined with multivariate analysis, respectively. Principal component analysis (PCA) and discriminant function analysis (DFA) dendrogram of peony floral scents were not precisely same but there were 3 groups including same cultivars. PCA and partial least squares-discriminant analysis (PLS-DA) dendrograms of peony metabolites showed that different cut peony cultivars were clustered into two major groups including same cultivars. Fragrance pattern of Korean 'Taebaek' was classified to same group with 'Jubilee' on the PCA and DFA results and its metabolite pattern was clearly discriminated by the PCA and PLS-DA compared to the other cultivars. These results show that the 14 peony cut flowers could be discriminated corresponding to their chemical relationship and the metabolic profile of Korean 'Taebaek' has distinctive characteristics. Furthermore, we suggest that these results could be used as the preliminary data for breeding new cut peony cultivars and for improving the availability of Korean cut peony in cosmetic industry.

상급종합병원 입원환자의 욕창발생 위험예측을 위한 Braden Scale의 타당도 검증 (Determining Optimal Cut-off Score for the Braden Scale on Assessment of Pressure Injury for Tertiary Hospital Inpatients)

  • 박숙현;최혜연;손연정
    • 중환자간호학회지
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    • 제16권3호
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    • pp.24-33
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    • 2023
  • Purpose : This study aims to establish an optimal cut-off score on the Braden scale for the assessment of pressure injury to detect pressure injury risks among inpatients in a South Korean tertiary hospital. Methods : This retrospective study used electronic medical records, from January to December 2022. A total of 654 patients were included in the study. Of these, 218 inpatients with pressure injuries and 436 without pressure injuries were classified and analyzed using 1:2 Propensity Score Matching (PSM), and the generalized estimating equation was performed using SPSS Version 26 and the R Machlt package program. Results : The cut-off value on the Braden scale for distinguishing pressure injury was 17 points, and the AUC (area under the ROC curve) was 0.531 (0.484-0.579). The sensitivity was 56.6% (45.5-67.7%) and the specificity was 69.7% (66.0-73.4%). With 17 points, the Braden scale cut-off distinguished those who had pressure injuries from those who did not at the time of admission (p < .03). In the pressure injury group, the Braden score on the day of the pressure injury was 14, with significant results in all subcategories except the moisture category. Conclusion : Our findings revealed that a cut-off value of 17 was optimal for predicting the risk of pressure injuries among tertiary hospital inpatients. Future studies should evaluate the optimal cut-off values in different clinical environments. Additionally, it is necessary to conduct multicenter large sample studies to verify the effectiveness of a 17 value in PI risk assessments.

FEM을 이용한 GIS내 부분방전 신호의 전파특성 해석 (Analysis of Partial Discharge Signal Propagation Characteristics in GIS Using FEM)

  • 이도훈;이현동;이용희;박기훈;류강열;신양섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 C
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    • pp.1835-1837
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    • 2004
  • The UHF electromagnetic waves excited by PD pulses propagate along the GIS busbar not only TEM mode, but also TE and TM mode. Generally the waves detected by the UHF sensors are those of high order modes and such waves can only propagate the higher than cut-off frequency. In this paper, computed cut-off frequency of 362[kV] GIS by each modes and simulated electromagnetic field of each propagation modes by FEM(Finite Element Method) program. Frequency band of each TEmn/TMmn modes were determinated by simulation results and were discussed optimal position of UHF sensor from this results.

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나노초 펄스폭을 갖는 자외선 레이저를 이용한 전자회로기판의 저항체 트리밍과 절단공정 특성에 관한 연구 (Study of Laser Trimming and Cutting of Printed Circuit Board by using UV Laser with Nanosecond Pulse Width)

  • 류광현;신석훈;박형찬;남기중;권남익
    • 한국정밀공학회지
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    • 제27권10호
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    • pp.23-28
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    • 2010
  • Resistance trimming and cutting processes of printed circuit board by making use of high power UV laser with nano-second pulse width have been proposed and investigated experimentally. Also laser-based application system with high flexibility and complex has been designed and adopted power controller, auto beam size control, auto-focusing and control program developed for ourselves. The function of each module shows that they can be reliable for industrial equipments. Resistance trimming method used a plunge and double cut process with $20{\mu}m$ spot size beam. Results show that double cut process is more effective to control resistance trimming in precision than plunge cut process.

Endoscopic resection of gastric gastrointestinal stromal tumor using clip-and-cut endoscopic full-thickness resection: a single-center, retrospective cohort in Korea

  • Yuri Kim;Ji Yong Ahn;Hwoon-Yong Jung;Seokin Kang;Ho June Song;Kee Don Choi;Do Hoon Kim;Jeong Hoon Lee;Hee Kyong Na;Young Soo Park
    • Clinical Endoscopy
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    • 제57권3호
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    • pp.350-363
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    • 2024
  • Background/Aims: To overcome the technical limitations of classic endoscopic resection for gastric gastrointestinal stromal tumors (GISTs), various methods have been developed. In this study, we examined the role and feasibility of clip-and-cut procedures (clip-and-cut endoscopic full-thickness resection [cc-EFTR]) for gastric GISTs. Methods: Medical records of 83 patients diagnosed with GISTs after endoscopic resection between 2005 and 2021 were retrospectively reviewed. Moreover, clinical characteristics and outcomes were analyzed. Results: Endoscopic submucosal dissection (ESD) and cc-EFTR were performed in 51 and 32 patients, respectively. The GISTs were detected in the upper third of the stomach for ESD (52.9%) and cc-EFTR (90.6%). Within the cc-EFTR group, a majority of GISTs were located in the deep muscularis propria or serosal layer, accounting for 96.9%, as opposed to those in the ESD group (45.1%). The R0 resection rates were 51.0% and 84.4% in the ESD and cc-EFTR groups, respectively. Seven (8.4%) patients required surgical treatment (six patients underwent ESD and one underwent cc-EFTR,) due to residual tumor (n=5) and post-procedure adverse events (n=2). Patients undergoing R0 or R1 resection did not experience recurrence during a median 14-month follow-up period, except for one patient in the ESD group. Conclusions: cc-EFTR displayed a high R0 resection rate; therefore, it is a safe and effective therapeutic option for small gastric GISTs.

Exogenous Sugars Involvement in Senescence and Ethylene Production of Tree Peony 'Luoyang Hong' Cut Flowers

  • Zhang, Chao;Liu, Miao;Fu, Jianxin;Wang, Yanjie;Li, Dong
    • 원예과학기술지
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    • 제30권6호
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    • pp.718-724
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    • 2012
  • Sugars play important roles in petal senescence of cut flowers. In the Expt. 1 of this study, the effects of different concentrations of glucose (60, 90, and $120g{\cdot}L^{-1}$) and sucrose (30, 60, and $90g{\cdot}L^{-1}$) application on the vase life, rate of flower diameter increase, rate of flower weight increase and ethylene production of cut tree peony (Paeonia suffruticosa 'Luoyang Hong') were evaluated. At the earlier stage, treatments of different concentrations of glucose and sucrose all retarded the process of flower opening and inhibited the increase of flower diameter and weight, while senescence of flowers fed with different concentrations of glucose was delayed at later stage. Flowers treated with $90g{\cdot}L^{-1}$ glucose displayed the longest vase life, which showed significant difference (P < 0.05) from those of flowers with the control and sucrose treatments. All treatments with glucose or sucrose not only retarded the decrease of flower diameter and weight, but also suppressed the ethylene production at the earlier stage and delayed the peak of ethylene evolution. In order to study the effect of exogenous sugar on the postharvest response of cut tree peony to ethylene, Expt. 2 was conducted. Cut flowers were treated with $90g{\cdot}L^{-1}$ glucose for 4 hours before (GE) or after (EG) exposed to $10{\mu}L{\cdot}L^{-1}$ ethylene for 4 hours. Generally, the opening process of flowers with GE and EG treatments was similar to that of the control, however GE treatment delayed flower senescence. Both GE and EG treatments improved flower diameter and weight, and GE treatment delayed the time of flower weight decrease. Besides, GE delayed climacteric ethylene evolution for 8 hours. All above suggest that exogenous sugars delay tree peony 'Luoyang Hong' cut flower senescence and extend flower vase life through their roles in the decrease of water loss and the suppression of sensitivity to ethylene and ethylene production.

엔드밀의 코너 가공시 가공 정밀도 향상에 관한 연구 (Improvement of the Accuracy in Cornering Cut Using End Mill)

  • 김용현;고성림
    • 대한기계학회논문집A
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    • 제25권3호
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    • pp.399-407
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    • 2001
  • The Surface, generated by end milling operation, is deteriorated by tool runout, vibration, friction, tool deflection, etc. Especially in cornering cut, surface accuracy is usually determined by varying cutting forces, which causes tool deflections. Cutting conditions like feed rate is usually kept constant during machining a part, which causes dimensional error in severe cutting. Cornering cut is a typical example of deterioration of surface accuracy when constant feed rate is applied. Therefore it becomes important to develop NC post processor module to determine optimal cutting conditions in various cutting situations. In this paper, cutting force is predicted in cornering cut with flat end mill and feed rate is determined by constraining constantly resultant force. Also some control characteristics of CNC machining center are evaluated.