• Title/Summary/Keyword: 3DP

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Effect of the Stratification of Perlite by Particle Size on the Growth and Yield of Tomato in a Recycling Hydroponics (폐쇄형 시스템에서 펄라이트 배지의 성층이 토마토의 생육 및 수량에 미치는 영향)

  • 강경희;권기범;최영하;이한철
    • Journal of Bio-Environment Control
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    • v.12 no.2
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    • pp.83-88
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    • 2003
  • The effect of vertical stratification of perlite by particle size on the growth and yield of tomato In a recycling hydroponics was examined. Vertical stratifications were composed of mixed form of small medium and large size (MP), divided forms of small and large size (smal1/1arge, DP I), and medium and large size (medium/large, DP II). Tomatoes showed higher growth in divided form, specially in DP II than DP I. Deformed fruits had higher occurrence by 17.8% in the mixed form than divided forms, while they were not significantly different between mixed forms. Root activity tended to increase during 20 days to 50 days after transplanting (DAT) in all treatments, but showed highest value at 50 DAT in DP II. After harvest electric conductivity and pH of stratified perlite were slightly higher in upper zone of DP I, but were not different in the other treatments. Mineral contents in the medium after harvest were higher in lower zone than the upper zone in MP and DP II, but vice versa in DP I.

Prediction of Fracture Strains for DP980 Steel Sheets for a Wide Range of Loading Paths (다양한 하중경로에서의 DP980 강판의 파단변형률 예측에 관한 연구)

  • Park, N.;Huh, H.
    • Transactions of Materials Processing
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    • v.24 no.3
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    • pp.176-180
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    • 2015
  • The current study is concerned with the prediction of fracture strains for DP980 steel sheets over a wide range of loading paths. The use of DP980 steel is increasing significantly in automotive industries for enhanced safety and higher fuel efficiency. The material behavior of advanced high-strength steels (AHSSs) sheets sometimes show unpredictable and sudden fracture during sheet metal forming. A modified Lou-Huh ductile fracture criterion is utilized to predict the formability of AHSSs because the conventional forming limit diagram (FLD) constructed based on necking is unable to evaluate the formability of AHSSs sheets. Fracture loci were extracted from three dimensional fracture envelopes by assuming the plane-stress condition to evaluate equivalent plastic strains at the onset of fracture for a wide range of loading paths. Three different types of specimens -- pure shear, dog-bone and plane strain grooved -- were utilized for tensile testing to calibrate the fracture model of DP980 steel sheets. Fracture strains of each loading path were evaluated such that there shows little deviation between fracture strains predicted from the fracture model and the experimental measurements. From the comparison, it is clearly shown that the three dimensional fracture envelopes can accurately predict the onset of the fracture of DP980 steel sheets for complicated loading conditions from compressive loading to shear loading and to equibiaxial tensile loading.

Analysis of Facial Asymmetry in Deformational Plagiocephaly Using Three-Dimensional Computed Tomographic Review

  • Moon, Il Yung;Lim, So Young;Oh, Kap Sung
    • Archives of Craniofacial Surgery
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    • v.15 no.3
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    • pp.109-116
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    • 2014
  • Background: Infants with deformational plagiocephaly (DP) usually present with cranial vault deformities as well as facial asymmetry. The purpose of this study was to use three-dimensional anthropometric data to evaluate the influence of cranial deformities on facial asymmetry. Methods: We analyzed three-dimensional computed tomography data for infants with DP (n=48) and without DP (n=30, control). Using 16 landmarks and 3 reference planes, 22 distance parameters and 2 angular parameters were compared. This cephalometric assessment focused on asymmetry of the orbits, nose, ears, maxilla, and mandible. We then assessed the correlation between 23 of the measurements and cranial vault asymmetry (CVA) for statistical significance using relative differences and correlation analysis. Results: With the exception of few orbital asymmetry variables, most measurements indicated that the facial asymmetry was greater in infants with DP. Mandibular and nasal asymmetry was correlated highly with severity of CVA. Shortening of the ipsilateral mandibular body was particularly significant. There was no significant deformity in the maxilla or ear. Conclusion: This study demonstrated that the cranial vault deformity in DP is associated with facial asymmetry. Compared with the control group, the infants with DP were found to have prominent asymmetry of the nose and mandible.

Effects of hexane fraction of Dracocephalum palmatum Stephan leaf on human-derived prostate cancer cell death (Dracocephalum palmatum Stephan 잎 헥산 분획 추출물의 인간 유래 전립선 암세포 사멸에 대한 작용)

  • Lee, Min Ji;Lee, Se-Eun;Choi, Na Ri;Jo, Sung Hyeon;Cho, Suin
    • The Korea Journal of Herbology
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    • v.33 no.4
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    • pp.69-76
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    • 2018
  • Objectives : Dracocephalum palmatum Stephan (Lamiaceae) is a medicinal plant used by the East-Russian nomads but there were few studies on this plant. This study was to evaluate anti-cancer effects of D. palmatum Stephan leaf hexane fraction on human derived prostate cancer cell death. Methods : The dried leaves of D. palmatum were dissolved in methanol, and hexane fraction (DpLH) was again obtained from lyophilized methanol extract (DpLM). DpLH was investigated by measuring by MTT assay and annexin V/PI staining to evaluate its effects on the cell viability and apoptosis of PC-3 cells. The ROS generations were detected by DCF-DA dye. The protein expressions were confirmed by p-AKT, Bcl-2, Bax, procaspase-3 activities. Results : After treatment of DpLH to PC-3 cells, the cell proliferation was significantly inhibited, and in addition, DpLH treatment also accelerated apoptosis of PC-3 cells. When DpLH was treated to the PC-3 cells, its ROS production significantly decreased. The proportion of all proteins (p-AKT/actin, Bcl-2/Bax and procaspase-3/actin ratios) showed decreasing tendency of expression compared with the control group. Conclusions : As shown in the above results, the extract from D. palmatum inhibits ROS production and promotes cell death, which is considered to be a relatively safe induction of cell death when administered to a living body. In conclusion, these results suggested that DpLH may have anti-cancer effect in human prostate cancer cell.

An evaluation of marginal fit of resin single crown manufactured using a dental 3D printer (치과용 3D 프린터를 활용해 제작된 레진 단일치관보철의 변연적합 평가)

  • Ki-Baek Kim
    • Journal of Technologic Dentistry
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    • v.44 no.4
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    • pp.126-131
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    • 2022
  • Purpose: The purpose of this study is to evaluate the quality of dental fixed prostheses fabricated by 3DP (three-dimensional printing). Methods: Ten main models were prepared for the study. Ten specimens were printed by 3DP (3DP group). Ten specimens were fabricated by the lost wax technique and casting method to complete the control group (LWC group). The marginal fit was measured for 20 specimens. The measurement of marginal fit was performed using the silicon replica technique. Finally, the marginal fit of 10 specimens from each group was calculated. An independent sample t-test was run to see if the calculated averages for the two groups were mutually significant (α=0.05). Results: According to the experimental results, the mean marginal fit of the 3DP group was 71.9 ㎛, and the LWC group was 55.3 ㎛. The means of the two groups were found to be significantly different (p<0.001) in the results of the independent sample t-test. Conclusion: The marginal fit of fixed dental prostheses produced by 3DP technology was examined with values greater than those fabricated by traditional technology. However, as it appeared to be a value within the range of clinically acceptable range recommended by numerous studies, it was determined that clinical application would be feasible.

Hop stunt viroid (HSVd) Sequence Variants from Dapple Fruits of Plum (Prunus salicina L.) in Korea (국내 얼룩반점 자두에서 발생한 호프왜화바이로이드(HSVd)의 유전자 변이)

  • Cho, In-Sook;Chung, Bong-Nam;Cho, Jeom-Doeg;Choi, Seung-Kook;Choi, Gug-Seoun;Kim, Jeong-Soo
    • Research in Plant Disease
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    • v.17 no.3
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    • pp.358-363
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    • 2011
  • Dapple fruits of plum cv. Oiishiwase (Prunus salicina L.) were occurred at Gyeonggi-do and Gyeongsangbukdo. The symptoms resembled the dapple fruit disease caused by Hop stunt viroid (HSVd). To identify the causal disease agents, RT-PCR was performed with the specific primers of HSVd. RT-PCR analysis showed that HSVd variants (DP1, DP2) were detected from dapple fruits. HSVd detection was also confirmed by the dot blot hybridization using a DIG-probe specific to HSVd. Nucleotide sequences of DP1 and DP2 had the identities of 94-100% with those of other 7 variants of HSVd in Genbank database. DP1 and DP2 were different in two nucleotides of CG and AA at position of 59 and 60, orderly. Based on nucleotide sequences at position of 59 and 60, HSVd variants associated with plum dapple fruits could be divided mainly into three groups as CG, AA and TG.

Physicochemical and structural properties of lintnerized starches from sweet Potato (고구마전분의 산처리 특성과 산분해 잔사의 구조적 특성)

  • Kim, Sung-Ran;Ahn, Seung-Yo
    • Applied Biological Chemistry
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    • v.35 no.3
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    • pp.196-201
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    • 1992
  • Characteristics on lintnerization of dry type (Suwon 147) and moist type (Hwangmi) sweet potato starches were investigated. Chain distribution of lintnerized starches was also studied by debranching with pullulanase. Hydrolytic patterns of two starches showed two distinct stages and hydrolysis extents of Suwon 147 starch were lower than those of Hwangmi starch. The relative crystallinities of Suwon 147 starches were higher than those of Hwangmi starch. The elution profiles of lintnerized starches were composed of two peaks about degree of polymerization (DP) 25 and DP 15. The elution profiles of debranched samples showed only one peak about DP 15 and peak DP of Suwon 147 lintnerized starch was higher than that of Hwangmi.

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A Study on FSA Application for Human Errors of Dynamic Positioning Vessels Incidents

  • Chae, Chong-Ju
    • Journal of Navigation and Port Research
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    • v.41 no.5
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    • pp.259-268
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    • 2017
  • Formal Safety Assessment (FSA) has been mostly implemented on the hardware aspects of vessels. Although there are guidelines regarding human error FSAs, there have not been many assessments in such areas. To this end, this study seeks to use precedent studies for the safe operation of DP vessels, conducting an FSA regarding human error of DP LOP (Loss of Position) incidents. For this, the study referred to precedent studies for the frequency of DP LOP incidents caused by human errors, adding the severity of LOP incidents, and then applying them to the Bayesian network. As a result, the study was able to confirm that among DP LOP incidents caused by human errors, the drive-off from skill-based errors was 74.3% and the drive-off from unsafe supervision was 50.5%. Based on such results, RCOs (Risk Control Options) were devised through a brainstorming session with experts coming up with proposals including providing mandatory DPO training, installing DP simulator on the vessels, drawing up measures to understanding the procedures for safe operation of DP vessels. Moreover, it was found that mandatory DPO training is reasonable in terms of cost benefits and that while installing a DP simulator is not suitable in terms of cost benefits, it can significantly reduce risks when operating DP vessels.

A Study of SFFS for Office Type using Three-dimensional Printing Process (3DP 공정을 이용한 오피스용 임의형상 제작시스템 에 관한 연구 (SFFS))

  • 이원희;김동수;이택민
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.1128-1131
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    • 2004
  • SFF(solid freeform fabrication) is another name of RP(rapid prototyping). The SFFS for office type wishes to develop system that can produce small object such as hand phone, cup, accessory etc. with high speed, and also intend suitable system in office environment by compact design, and buy easily by inexpensive price. As can manufacture high speed in existent SFF process technology, representative process that have competitive power in price is 3DP (three dimensional printing) technology. The 3DP technology is way to have general two dimensional printing technology and prints to three dimension, is technology that make three-dimensional solid freeform that want binder doing jetting selectively on powder through printer head. We designed and manufactured SFFS for office based on 3DP process technology design and manufactured, and composed head system so that use 3 printer heads at the same time to improve the fabrication speed of system. We used printer head of INCJET company and cartridge used HP45 series model who can buy easily in general city. And we directly fabricated three dimensional solid freeform using developed SFFS for office type.

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Improvement of Luminance Properties of Blue OLEO using $SnDP(HPB)_2$ (Sn-complexes를 이용한 OLED의 발광 특성 향상에 관한 연구)

  • Kim, Dong-Eun;Choi, Gyu-Chae;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04c
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    • pp.121-122
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    • 2008
  • Blue emitting materials have been explored by various researchers. However, blue-emitting materials with high luminous efficiency, good color purity, and thermal stability are still much desired. In this study, we synthesized a new blue luminescent material, $SnDP(HPB)_2$ which is low molecular compound and thermal stability. The PL spectrum of $SnDP(HPB)_2$ was observed blue at the wavelength of 447nm. The ionization potential(IP) and the electron affinity(EA) of $SnDP(HPB)_2$ was measured to be 6.7 eV and 3.0 eV, respectively. The fundamental structure of the OLED was ITO/NPB/$SnDP(HPB)_2/Alq_3$/LiF/Al. As a Result, we obtained to enhance the performance of blue OLED.

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