• 제목/요약/키워드: cutting strength

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Study on Practical Micropropagation of Juiube Cultivars through Axillary Bud Culture (액아배양(腋芽培養)에 의한 신품종(新品種) 대추나무의 실용적(實用的)인 대량증식(大量增殖)에 관(關)한 연구(硏究))

  • Kim, Deok Sik;Lee, Sei Pyo
    • Journal of Korean Society of Forest Science
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    • v.77 no.4
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    • pp.445-452
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    • 1988
  • This study was conducted to establish practical micropropagation of jujube cultivars ('Geumsumg', 'Bokjo') by axillary bud culture. The results are summerized as follows : 1. Addition of activated charcoal to half-strength Murashige and Skoog(MS) medium supplemented with 0.5mg/l benzylaminopurine(BAP) enhanced shoot and root growth. At 500mg/l activated charcoal level 'Geumsung' showed best result, and shoot length and the number of multiple shoot were 6.4cm and 10.0, respectively. At 1,000mg/l activated charcoal level 'Bokjo showed best result, and shoot length and the number of multiple shoot were 7.5cm and 12.4, respectively. 2. As indole-3-butyric acid(IBA) concentration increased, rooting and callus growth of microshoot were enhanced. The optimum IBA concentration for shoot elongation and multiplication was 1.0mg/l. 3. Growth responses of shoot-tip and axillary bud segments between two jujube cultivars were different. 'Geumsung' showed that axillary bud explants were about twice better than shoot-tip explants for shoot multiplication, but 'Bokjo' showed that shoot-tip explants mere better than axillary bud explants for shoot elongation and multiplication. 4. In acclimatization processes of plantlets produced in vitro, the survival of plantlets with only root primordia in soil medium was better than that of plantlets with several routs resulting in 97.8%. 5. In cutting of in vitro-derived microshoot, paclobutrazol was more effective than IBA, naphth-aleneacetic acid(NAA) and $Rooton^{(R)}$ in rooting and root growth.

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Quality and minimal processing characteristics of 'Ssam' vegetables during storage (국내산 쌈채소의 신선편의 가공적성 및 저장 중 품질변화)

  • Hwang, Tae-Young
    • Korean Journal of Food Science and Technology
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    • v.49 no.6
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    • pp.632-637
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    • 2017
  • This study was conducted to determine the minimal processing characteristics of four vegetables (brown mustard, kale, red beet and red lettuce) for wrapping (Ssam). Prior to evaluation, the vegetable leaves were cut, washed, and packaged. The texture, weight loss, browning index, pH, gas concentrations ($O_2$ and $CO_2$), microbial growth, and organoleptic qualities of the leaves were assessed at $10^{\circ}C$ for 7 days. The cutting strength of red beet was significantly different among leaves. The initial springiness of brown mustard was the lowest (0.98%). The weight loss varied between 0.24 to 4.77%, pH ranged from 6.00 to 6.95, and browning index increased to 0.95 during storage. Changes of gas composition were lower in cut leaf than whole leaf. Aerobic bacteria (4.9-8.0 log CFU/g), yeast (not detected), mold (-3.5 log CFU/g), and total coliforms (5.0-8.0 log CFU/g) were assessed in the samples. Thus, overall quality of kale and red beet leaves with minimal processing showed satisfactory results when stored for 7 days.

Analysis of PLAN Modernization Trend and Prospects for Balance of U.S-China Naval power in the East Asia (중국해군(PLAN)의 현대화 추세와 동아시아 지역의 미·중 해군력 균형 전망)

  • Kwon, Jeong Wook
    • Strategy21
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    • s.43
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    • pp.5-28
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    • 2018
  • The tensions between the U.S and China, which form the two pillars of the G2 era, seem to have persisted even after the Trump administration inaugurated. The strong confrontation between the two in recent foreign security issues may drive to develop an inadvertent military conflict, and it is high likely to occur in the maritime are. The purpose of this study is not only to analyze the balance of modernized naval forces in the PLAN through naval strategy changes and weapons system modernization trend, but also to predict the impact of the geographical proximity difference on the balance of naval forces in the disputed areas. It examined the impact of distance and geography on naval power by assessing the modernization pattern of the PLAN and capabilities in the context of two scenarios at different distances from China by 2020: one centered on Taiwan and the other on the Spratly Islands. The PLAN's strategy had impact on operational concept and forces construction. First, from the viewpoint of operation operational concept, it can be seen that the passive defense is changing into active defense. Second, in terms of power construction, it can threaten the surface and submarines of U.S power from a distance. And they generated follow three features; The ocean is not the focus of Chinese submarines, Horizontal and vertical expansion of Chinese naval vessels, The improvement of the suppression ability as the Chinese naval modernization ratio increases. The strength of the PLAN is dominant over the U.S in terms of reserves, and it can complement the qualitative deterioration by utilizing nearby bases in the vicinity of the mainland, such as the Taiwan Strait. However, due to the shortage of aircraft carriers, there is a possibility that it will take some time to secure the advantage of air and ocean in the amphibious operation. Therefore, as the dispute is prolonged, China may fail to achieve its original goal. In addition, the lack of cutting edge Commanding Ships may bring to weaken the C2 capabilities. At results, it is expected that PLAN will not be able to have a superiority in the short term due to lagging behind U.S advanced technology. Nevertheless, PLAN has strengthened its naval power through modernization sufficiently and it is highly likely to use force. Especially, it is more likely in the region where the naval power operation like the Taiwan Strait is possible with the almost equality to that of the United States. China will continue to use its naval forces to achieve a rapid and decisive victory over U.S in the close area from the land.

A STUDY ON THE DEGREE OF CONVERSION OF LIGHT CURING COMPOSITE RESIN ACCORDING TO THE THICKNESS OF TOOTH STRUCTURE PENETRATED BY LIGHT AND APPLIED LIGHT CURING TIME (조사광이 통과하는 치질의 두께와 광조사시간에 따른 광중합형 복합레진의 중합률에 관한 연구)

  • Hwang, Kee-Hwan;Jang, In-Ho;Lee, Se-Joon;Lee, Kwang-Won
    • Restorative Dentistry and Endodontics
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    • v.27 no.1
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    • pp.16-23
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    • 2002
  • Physical properties of composite resins such as strength, resistance to wear, discoloration, etc depend on the degree of conversion of the resin components. The purpose of this study was to evaluate the degree of conversion of the composite resins according to the thickness of tooth structure penetrated by light and applied light curing time. The coronal portions of extracted human teeth (one anterior tooth, three posterior tooth) was embedded by pink denture material. the mounted teeth were cut into three illumination sections (1mm thickness enamel section, 1mm thickness dentin section, 2mm thicknes dentin section) and one backing section with cutting wheel. Thin resin films were made by using 6kg pressure between slide glass during 5 minutes Thin resin film was light cured on coupled illumination section during 40sec, 80sec and 120sec. each illumination section was coupled as follows; no tooth structure(X), ename section(E), enamel section + 1mm dentin section(ED1), enamel section + 2mm dentin section(ED2), enamel section + 1mm dentin section + 2mm dentin section(EDD). To simulate the clinical situation more closely, thin resin films was cured against a backing section of tooth structure. The degree of conversion of carbon double bonds to single bonds in the resin films were examined by means of Fourier Transform Infrared Spectrometer. The results were obtained as follows ; 1 As curing time was increased, conversion rate was increased and as tooth thickness which was penetrated by curing light was increased, conversion rate was decreased. 2. At all tooth thickness groups, conversion rate between 80sec and 120sec was not significantly increased(P>0.05). 3. At 40sec group and 80sec, conversion rate between no tooth structure(X) group and 1mm enamel section(E) group was not significantly decreased(P>0.05). 4. At 80sec group and 120sec, conversion rate between 1mm enamel section(E) group and 1mm enamel section + 1mm dentin section(ED1) group was not significantly decreased(P>0.05).

The Microstructural Properties Change Owing to the Sintering Condition of T42 High Speed Steel Produced by Powder Injection Molding Process (분말 사출 성형법으로 제조된 T42 고속도 공구강의 소결 조건에 따른 조직 특성 변화)

  • Do, Kyoung-Rok;Choi, Sung-Hyun;Kwon, Young-Sam;Cho, Kwon-Koo;Ahn, In-Shup
    • Journal of Powder Materials
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    • v.17 no.4
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    • pp.312-318
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    • 2010
  • High speed steels (HSS) were used as cutting tools and wear parts, because of high strength, wear resistance, and hardness together with an appreciable toughness and fatigue resistance. Conventional manufacturing process for production of components with HSS was used by casting. The powder metallurgy techniques were currently developed due to second phase segregation of conventional process. The powder injection molding method (PIM) was received attention owing to shape without additional processes. The experimental specimens were manufactured with T42 HSS powders (59 vol%) and polymer (41 vol%). The metal powders were prealloyed water-atomised T42 HSS. The green parts were solvent debinded in normal n-Hexane at $60^{\circ}C$ for 24 hours and thermal debinded at $N_2-H_2$ mixed gas atmosphere for 14 hours. Specimens were sintered in $N_2$, $H_2$ gas atmosphere and vacuum condition between 1200 and $1320^{\circ}C$. In result, polymer degradation temperatures about optimum conditions were found at $250^{\circ}C$ and $480^{\circ}C$. After sintering at $N_2$ gas atmosphere, maximum hardness of 310Hv was observed at $1280^{\circ}C$. Fine and well dispersed carbide were observed at this condition. But relative density was under 90%. When sintering at $H_2$ gas atmosphere, relative density was observed to 94.5% at $1200^{\circ}C$. However, the low hardness was obtained due to decarbonization by hydrogen. In case of sintering at the vacuum of $10^{-5}$ torr at temperature of $1240^{\circ}C$, full density and 550Hv hardness were obtained without precipitation of MC and $M_6C$ in grain boundary.

Manufacture Lenticular Map of Golf Courses Using Digital Orthophoto (수치정사영상을 이용한 렌티큘러 코스맵 제작)

  • Kim, Kam-Lae;Cheong, Hae-Jin;Cho, Won-Woo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.25 no.5
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    • pp.475-482
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    • 2007
  • Most golfers believe that knowing yardages will improve their score. Certainly it helps with club selection. But, simple "Graphic" yardage guides being notorious for error and inaccuracies, which a serious golfer will pick immediately, only serve to erode the players enjoyment and ultimately, golf course satisfaction. Someone believes with low-level aerial photographic images, golfer will be impressed with the accuracy of the depiction, helping them play a more confident game. But, there are no mapping products in true 3-D available in the world that allows a golfer to determine shot distances in yards or meters. So, we suggest an lenticular technology for real 3-D display as a viable alternative to conventional image map solution. This technology is an image display method for the generation of multi-image effects like 3D visualization or animation. This methodology is cutting edge stereoscopic image which overcomes the limitation of conventional photo tech by recomposing and producing 3 dimensional images. A significant strength of this methods its versatility concerning display effects. The main use of the hardcopy 3-D lenticular displays is in the fields of science, education, planning, and representation. This paper gives a concise overview of the lenticular foil technology and describes the production of the true 3-D yardage book of golf courses. For this study, 3-D effects are achieved and evaluated with the lenticular display by incorporation multiple synthetic images based on digital topographic terrain model and by using the two images of the actual stereopair.

Protease activity and meat-tenderizing effect of Hypsizygus marmoreus (느티만가닥버섯의 단백질분해효소 활성과 연육증진효과)

  • Shin, Bok-Eum;Baek, Il-Sun;Kim, Jeong-Han;Lee, Yun-Hae
    • Journal of Mushroom
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    • v.17 no.4
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    • pp.235-240
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    • 2019
  • In this study, we investigated the effects of pH, temperature, and salt concentration on protease activities in Hypsizygus marmoreus, and the ability of H. marmoreus extract to tenderize beef. In fact, H. marmoreus was shown to have higher protease activity than kiwi fruits. The pH of beef was dose dependently increased with addition of H. marmoreus extract. Cooking loss, cutting strength, and color value (L, a, b) were also dose dependently decreased with addition of H. marmoreus extract. In sensory assessments, H. marmoreus extract dose dependently enhanced perception of tenderness, flavor, and taste. In contrary, use of kiwi fruits as a meat tenderizer decreased positive perception of taste. The protease activitiy of H. marmoreus decreased sharply at pH < 2.0, and temperature > 50 ℃. Protease activity was relatively stable in NaCl concentrations ranging from 0-5 M, but incrementally decreased with increasing NaCl. These results suggest that, H. marmoreus extract can improve the texture and taste of beef.

Effect of Different Pre-treatments on the Physicochemical and Antioxidant Activities of Cold-Vacuum Dried Peaches (전처리조건에 따른 냉풍감압건조 복숭아의 이화학적 및 항산화 활성)

  • Kwon, Gi-Man;Kim, Jae-Won;Youn, KwangSup
    • Korean Journal of Food Science and Technology
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    • v.45 no.4
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    • pp.466-472
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    • 2013
  • This study was performed to determine the effects of the pretreatment and cold-vacuum drying methods on the physicochemical properties and antioxidant activities of dried peaches. Moisture content was significantly lower with 0.3% NaCl treatment with cold-vacuum drying. The pH, brix and acid ratio (SS/TA) were the lowest with 1.0% soluble Ca treatment, while soluble solid and SS/TA were significantly higher with 0.1% vitamin C treatment compared to those with other treatments. The ${\delta}E$ and browning degree was lower in the pretreated sample compared to the untreated sample. Cutting strength of dried peaches was highest in the pretreated samples, and it was the highest with 1.0% soluble Ca treatment. Total sugar content with 0.1% vitamin C and 1.0% soluble Ca treatment was significantly higher than that with 0.3% NaCl treatment. The free sugar content was lower with 0.3% NaCl treatment but it was higher with 0.1% vitamin C and 1.0% soluble Ca treatment. The sensory evaluation result was highest with 0.1% vitamin C treatment. Phenolic compounds and antioxidant ability were the highest with the 0.1% vitamin C and 0.1% soluble Ca treatment; all the dried peaches showed relatively high antioxidant activities. These results suggest that pretreatment can affect the quality of dried peaches, showing that cold-vacuum drying can be applied for the production of high quality dried peach products.

Development of Integrated Wireless Sensor Network Device with Mold for Measurement of Concrete Temperature (콘크리트 온도 측정을 위한 거푸집 일체형 무선센서네트워크 장치 개발)

  • Lee, Sung Bok;Park, Seong Sik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.5
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    • pp.129-136
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    • 2012
  • Temperature of fresh concrete can be effectively used to predict the strength of concrete being cured and make an informed decision for stripping the molds. A hygrothermograph and thermo-couple sensors that require an extensive wiring have been applied to measure a temperature of concrete at the early stage of the curing process on site. However, these methods have limits to provide the temperature data in real time due to harsh working environment including frequent cutting of wires. Therefore, this study is aiming at developing a device based on wireless sensor network to measure the temperature of concrete being cured in formwork. The result showed that the wireless sensor with probe type thermistor which is developed had the same temperature data compared to the existed wire type thermistor, and we confirmed the temperature history of concrete in real time for 28 days throughout the gateway by wireless network that collects the temperature data measured from specimens in laboratory. Also, the network device for transmission can be easily separated from the probe sensor part and reused consistently. If the wireless sensor network device developed uses in the field, the temperature management of concrete will be systematically conducted from at the early stage of the curing, and especially be effective for cold weather concrete construction. In addition, it will contribute to the establishment of advanced quality control system for concrete and productivity of supervisors on site will be increased in the future.

Studies on the Root Characteristics of Soybean Varieties in Korea (한국 대두 품종의 뿌리특성 연구)

  • Je-Cheon Chae;Eun-Sup Lee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.33 no.4
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    • pp.420-428
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    • 1988
  • Root is supposed to be important role in growth and yield formation of soybeans and also there is expected to exist varietal differences between soybean root morphology and system. 30 soybean varieties including 10 Korean recommended, 10 Introduced and 10 Korean native varieties were grown at field and pot under standard culture condition. Top and root characteristics were investigated at V4, R1 and R5 stage and T/R relations, correlations with yield were calculated. Top characteristics showed significant difference between 3 variety groups of Korean recommended, Introduced and Korean native variety. Stem length at R1 stage and stem length, stem diameter, number of nodes, number of branches, number of pods and grain yield at R5 stage were significantly different top characteristics. Root characteristics showed significant difference between 3 variety groups were number of thick primary root at V4 stage, primary root angle and root cutting strength at R1 stage, thick root diameter and root dry weight at R5 stage. The correlations between top and root characteristics and soybean yield was greatly different by soybean variety groups, and the top characteristics was more highly correlated then root characteristics. All the top and root characteristics of Korean recommended variety showed no correlations with yield. However, leaf area, stem length, top dry weight in Introduced variety and leaf area, top dry weight, number of nodes, number of thick primary root in Korean native variety were highly correlated with soybean yield.

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