• Title/Summary/Keyword: mechanical quality

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The Verification of Computer Simulation of Nitinol Wire Stent Using Finite Element Analysis (유한요소법을 이용한 나이티놀 와이어 스텐트의 전산모사 실험 데이터 검증)

  • Kim, Jin-Young;Jung, Won-Gyun;Jeon, Dong-Min;Shin, Il-Gyun;Kim, Han-Ki;Shin, Dong-Oh;Kim, Sang-Ho;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.20 no.3
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    • pp.139-144
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    • 2009
  • Recently, the mathematical analysis of stent simulation has been improved, with the help of development of various tool which measure mechanical property and location of stent in artery. The most crucial part of the stent modeling is how to design ideal stent and to evaluate the interaction between stent and artery. While there has been great deal of researches on the evaluation of the expansion, stress distribution, deformation of the stent in terms of the various parameters, few verification through computer simulation has been performed about deformation and stress distribution of the stent. In this study, we have produced the corresponding results between experimental test using Universal Testing Machine and computer simulation for the ideal model of stent. Also, we have analyzed and compared stress distribution of stent in the cases of that with membrane and that without membrane. The results of this study would provide minimum change of plan and good quality for ideal stent replacing damaged artery through the analysis using computer simulation in the early stage of stent design.

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Thin Layer Drying and Quality Characteristics of Ainsliaea acerifolia Sch. Bip. Using Far Infrared Radiation (원적외선을 이용한 단풍취의 박층 건조 및 품질 특성)

  • Ning, Xiao Feng;Li, He;Kang, Tae Hwan;Lee, Jun Soo;Lee, Jeong Hyun;Ha, Chung Su
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.6
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    • pp.884-892
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    • 2014
  • The purpose of this study was to investigate the drying characteristics and drying models of Ainsliaea acerifolia Sch. Bip. using far-infrared thin layer drying. Far-infrared thin layer drying test on Ainsliaea acerifolia Sch. Bip. was conducted at two air velocities of 0.6 and 0.8 m/sec, as well as three drying temperatures of 40, 45, and $50^{\circ}C$ respectively. The drying models were estimated using coefficient of determination and root mean square error. Drying characteristics were analyzed based on factors such as drying rate, leaf color changes, antioxidant activity, and contents of polyphenolics and flavonoids. The results revealed that increases in drying temperature and air velocity caused a reduction in drying time. The Thompson model was considered suitable for thin layer drying using far-infrared radiation for Ainsliaea accerifolia Sch. Bip. Greenness and yellowness values decreased and lightness values increased after far-infrared thin layer drying, and the color difference (${\Delta}E$) values at $40^{\circ}C$ were higher than those at $45^{\circ}C$ and $50^{\circ}C$. The antioxidant properties of Ainsliaea acerifolia Sch. Bip. decreased under all far-infrared thin layer drying conditions, and the highest polyphenolic content (37.9 mg/g), flavonoid content (22.7 mg/g), DPPH radical scavenging activity (32.5), and ABTS radical scavenging activity (31.1) were observed at a drying temperature of $40^{\circ}C$ with an air velocity of 0.8 m/sec.

Development of RAPD-SCAR Molecular Marker Related to Seed-hair Characteristic in Carrot (당근(Daucus carota var. sativa) 종자모 형질 관련 RAPD-SCAR 분자표지 개발)

  • Shim, Eun-Jo;Park, Sung-Kwan;Oh, Gyu-Dong;Jun, Sang-Jin;Park, Young-Doo
    • Horticultural Science & Technology
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    • v.31 no.6
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    • pp.756-763
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    • 2013
  • Mechanical hair removal of carrot seed causes seed injuries and suppresses the germination in carrot cultivation. This study was performed to develop molecular markers for breeding high quality cultivars with short-hair seed. To meet this objective, random amplified polymorphic DNA (RAPD)-sequence characterized amplified region (SCAR) markers specifically linked to seed-hair characteristic were identified using CT-SMR 616 OP 389-1 line with short-haired seed and CT-SMR 616 OP 616-33 line with long-haired seed, bred by self-pollination for 6 years from 2008 to 2013, as parents. After seed hair lengths of these lines were analyzed using microscope, next generations were advanced and compared with the molecular markers polymorphism. From RAPD analysis using fixed lines in 2011, twelve RAPD primers showing polymorphic bands specific between the two lines were identified from 80 random primers. To develop RAPD-SACR marker, SCAR primers were designed based on sequence analysis of these specific RAPD bands and more than three combinations of primers were tested. As a result, it was found that the $SCA2_{1.2}$ amplified single polymorphic band from short-haired seed line. To confirm this result, $SCA2_{1.2}$ marker was retested by applying to the 2012 and 2013 progenies. Finally, it was concluded that the developed $SCA2_{1.2}$ marker distinguished short-haired line from long-haired seed line. Therefore, SCAR marker, $SCA2_{1.2}$ is expected to be utilized for breeding of the short-haired seed cultivars.

Preparation and Quality Characterization of Apple Jam with Rosa rugosa Thunb. Fruit (해당화 열매 첨가 사과잼 제조 및 품질 특성)

  • Kim, Mi-Hyun;Kim, Myung-Hee;Yun, Sun-Ju;Lee, Byung-Yong;Lee, Chang-Won;Kim, Bo-Ae;Jang, Ki-Hyo;Lee, Jae-Cheol;Surh, Jeong-Hee
    • Korean journal of food and cookery science
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    • v.26 no.4
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    • pp.367-380
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    • 2010
  • Various contents of Rosa rugosa Thunb. fruit(0, 10, 20%), which is grown along the seashore of Gangwon province, were applied to apple jams having different sugar concentrations(20, 40, 60%). The resulting jams were analyzed using a sensory scoring test as well as a response surface methodology to identify the optimum conditions for the preparation of high-preference apple jams. The sensory properties based on sense of sight, smell and taste appeared to be linked to the sugar contents. It could be attributed to the presence of flavor compounds and pigments generated from the caramelization of sugar molecules during heat processing. On the other hand, rheological properties such as viscosity and spreadability were associated with Rosa rugosa fruit content, which was also verified by textural analysis of the jams. As the contents of Rosa rugosa increased, the hardness, gumminess, and chewiness of the jams decreased, which eventually might have contributed to the less thick and thus more spreadable sensory characteristics. Sensory evaluation revealed that apple jams were preferred when prepared with $\leq$10% of Rosa rugosa fruit and $\geq$55% of sugar contents. In particular, apple jams containing 10% Rosa rugosa and 60% sugar showed better mechanical qualities as well as higher sensory preference among 10 jams formulated using central composite design.

Effects of Astringent Persimmon Paste on Quality Properties of Injeolmi (떫은감 농축액을 첨가한 인절미의 품질 특성)

  • Hong, Jin-Sook;Kim, Myoung-Ae
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.8
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    • pp.1232-1238
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    • 2005
  • The purpose of this study was to find the optimum addition amount of astringent persimmon paste to glutinous rice flour in the preparation of Gaminjeolmi (persimmon glutinous rice cake). The moisture contents of Gaminjeolmi with added astringent persimmon paste were 57$\∼$59$ \% $. With increasing addition of astringent persimmon paste, the L- and b-value were decreased. The a-value was the highest at the 8$\%$ level. In the mechanical evaluation of Gaminjeolmi, the hardness was the highest in the 0$\%$ astringent persimmon paste-lnjeolmi but the 0$\%$ level was decomposed after 2 day of storage. The adhesiveness and cohesiveness were the lowest at the 0$\%$ and 16$\%$ levels. The springiness did not differ significantly with the addition of astringent persimmon paste for 2 days of storage. The gumminess was the highest at the 0$\%$ level for 1 day of storage, significantly. In the sensory evaluation of Gaminjeolmi, the acceptance of the softness characteristics was the best at the 8$\%$ level. Addition of astringent persimmon paste improve preservation of Injeolmi and the addition of 8$\%$ of astringent persimmon paste to glutinous rice flour was found to be the best recipe in terms of the sensory qualities of softness and overall acceptability.

Performance Estimation of Large-scale High-sensitive Compton Camera for Pyroprocessing Facility Monitoring (파이로 공정 모니터링용 대면적 고효율 콤프턴 카메라 성능 예측)

  • Kim, Young-Su;Park, Jin Hyung;Cho, Hwa Youn;Kim, Jae Hyeon;Kwon, Heungrok;Seo, Hee;Park, Se-Hwan;Kim, Chan Hyeong
    • Journal of Radiation Protection and Research
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    • v.40 no.1
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    • pp.1-9
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    • 2015
  • Compton cameras overcome several limitations of conventional mechanical collimation based gamma imaging devices, such as pin-hole imaging devices, due to its electronic collimation based on coincidence logic. Especially large-scale Compton camera has wide field of view and high imaging sensitivity. Those merits suggest that a large-scale Compton camera might be applicable to monitoring nuclear materials in large facilities without necessity of portability. To that end, our research group have made an effort to design a large-scale Compton camera for safeguard application. Energy resolution or position resolution of large-area detectors vary with configuration style of the detectors. Those performances directly affect the image quality of the large-scale Compton camera. In the present study, a series of Geant4 Monte Carlo simulations were performed in order to examine the effect of those detector parameters. Performance of the designed large-scale Compton camera was also estimated for various monitoring condition with realistic modeling. The conclusion of the present study indicates that the energy resolution of the component detector is the limiting factor of imaging resolution rather than the position resolution. Also, the designed large-scale Compton camera provides the 16.3 cm image resolution in full width at half maximum (angular resolution: $9.26^{\circ}$) for the depleted uranium source considered in this study located at the 1 m from the system when the component detectors have 10% energy resolution and 7 mm position resolution.

Effect of Intravenous Administration of Tramadol on the Minimum Alveolar Concentration of Isoflurane in Dogs (개에서 트라마돌의 정맥투여가 아이소플루란의 최소폐포농도에 미치는 영향)

  • Seok, Seong-Hoon;Park, Se-Jin;Lee, Seung-Yong;Jin, So-Young;Kim, Young-Ki;Hwang, Jae-Min;Lee, Hee-Chun;Yeon, Seong-Chan
    • Journal of Veterinary Clinics
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    • v.32 no.4
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    • pp.308-312
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    • 2015
  • This study was aimed to evaluate the effects of tramadol hydrochloride on the minimum alveolar concentration of isoflurane ($MAC_{ISO}$) in dogs. Six healthy, female German shepherd dogs (aged 1-2 years) were used in this study. Anesthesia was induced by mask induction and maintained with isoflurane in oxygen. Mechanical ventilation maintained the end-tidal $CO_2$ partial pressure ($P_{ET}CO_2$) from 35 to 45 mmHg throughout the study. A baseline $MAC_{ISO}$ ($MAC_{ISO}B$) was determined starting 45 minutes after induction of anesthesia by clamping a pedal digit until gross purposeful movement was detected. After $MAC_{ISO}B$ determination, dogs received a tramadol loading dose of 3 mg/kg followed by a continuous rate infusion (CRI) of 2.6 mg/kg/h. The determination of $MAC_{ISO}$ after administration of tramadol ($MAC_{ISO}T$) began 20 min after the start of the CRI. Arterial blood pressure and heart rate were recorded continuously and arterial blood samples for blood gas analysis were collected at the end of the equilibration period. Mean ${\pm}$ SD values for the $MAC_{ISO}B$ and $MAC_{ISO}T$ were $1.33{\pm}0.04%$ and $1.23{\pm}0.04%$, respectively. The $MAC_{ISO}B$ decreased significantly by $7.5{\pm}0.2%$ (P < 0.05) after administration of tramadol. The mean heart rate and arterial blood pressure of six dogs were not changed significantly after tramadol administration. The blood gas levels remained constant during the study. In conclusion, tramadol could significantly reduce $MAC_{ISO}$ without depression of cardiorespiratory function. Thus, the use of tramadol on inhalation anesthesia with isoflurane in dogs can improve the stability of anesthesia and the quality of recovery.

Influences of Die Temperature and Repeated Extrusion on Physical Properties of Extruded White Ginseng (사출구 온도와 반복 압출성형이 백삼압출성형물의 물리적 특성에 미치는 영향)

  • Choi, Kwan-Hyung;Ryu, Gi-Hyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.6
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    • pp.921-927
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    • 2015
  • The aim of this study was to investigate the effect of die temperature and repeated extrusion on physical properties of extruded white ginseng (EWG). The die temperature was adjusted to 100, 120, and $140^{\circ}C$, and extrusion was repeated under the same conditions with their corresponding samples. Specific mechanical energy input decreased as die temperature increased during extrusions. The secondary extruded white ginseng (SEWG) at a die temperature of $120^{\circ}C$ showed a higher expansion index than other extrudates. Elevation of both die temperature and repeated extrusion increased the specific length of extrudates. The highest apparent elastic modulus, breaking strength, and water solubility index obtained from SEWG at a die temperature of $100^{\circ}C$ were $7.53{\times}10^8N/m^2$, $7.49{\times}10^5N/m^2$, and 39.02%, respectively. When die temperature increased, water absorption index (WAI) decreased. The WAI of SEWG was higher than that of EWG. In conclusion, repeated extrusion affected physical properties of white ginseng and could be applied to produce improved quality of ginseng products.

Storage Period of Milled Rice by Packaging Materials and Storage Temperature (온도와 포장재에 따른 백미의 저장가능기간)

  • Choi Yoon-Hee;Choung Jin-Il;Cheong Young-Keun;Kim Young-Doo;Ha Ki-Yong;Ko Jae-Kwon;Kim Chung-Kon
    • Food Science and Preservation
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    • v.12 no.4
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    • pp.310-316
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    • 2005
  • This study was carried out to investigate the quality characteristics by packaging materials and storage temperature to predict safe storage period for milled rice. Mechanical taste value and whiteness of milled rices stored at room temperature were severely decreased than those of the stored at low temperature, but fat acidity and b value of those at room temperature was rapidly increased than those of stored at low temperature. Milled rice packed in LDPE film bag were smelled stale flavor after 4 months storage at room temperature, Hojinbyeo was not produced flour in the rice grain surface but Dongjinbyeo was showed production of flour. pH of milled rice of Dongjinbyeo and Hojinbyeo packed in LDPE film bag were the lowest showing 5.3 and 5.6, respectively after 6 months at mom temperature. Safe storage period of Dongjinbyeo and Hojinbyeo packed in craft paper bag were 1 month at room temperature, those of packed in LDPE film bag were 2 months. At low temperature safe storage period of Dongjinbyeo and Hojinbyeo packed in craft paper bag were 2 months, those of packed in LDPE film bag were 5 and 4 months, respectively.

Investigation of Viscoelastic Properties of EPDM/PP Thermoplastic Vulcanizates for Reducing Innerbelt Weatherstrip Squeak Noise of Electric Vehicles (전기차 인너벨트 웨더스트립용 EPDM/PP Thermoplastic Vulcanizates 재료설계인자에 따른 점탄성과 글라스 마찰 소음 상관관계 연구)

  • Cho, Seunghyun;Yoon, Bumyong;Lee, Sanghyun;Hong, Kyoung Min;Lee, Sang Hyun;Suhr, Jonghwan
    • Composites Research
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    • v.34 no.3
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    • pp.192-198
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    • 2021
  • Due to enormous market growing of electric vehicles without combustion engine, reducing unwanted BSR (buzz, squeak, and rattle) noise is highly demanded for vehicle quality and performance. Particularly, innerbelt weatherstrips which not only block wind noise, rain, and dust from outside, but also reduce noise and vibration of door glass and vehicle are required to exhibit high damping properties for improved BSR performance of the vehicle. Thermoplastic elastomers (TPEs), which can be recycled and have lighter weight than thermoset elastomers, are receiving much attention for weatherstrip material, but TPEs exhibit low material damping and compression set causing frictional noise and vibration between the door glass and the weatherstrip. In this study, high damping EPDM (ethylene-propylene-diene monomer)/PP (polypropylene) thermoplastic vulcanizates (TPV) were investigated by varying EPDM/PP ratio and ENB (ethylidene norbornene) fraction in EPDM. Viscoelastic properties of TPV materials were characterized by assuming that the material damping is directly related to the viscoelasticity. The optimum material damping factor (tanδ peak 0.611) was achieved with low PP ratio (14 wt%) and high ENB fraction (8.9 wt%), which was increased by 140% compared to the reference (tanδ 0.254). The improved damping is believed due to high fraction of flexible EPDM chains and higher interfacial slippage area of EPDM particles generated by increasing ENB fraction in EPDM. The stick-slip test was conducted to characterize frictional noise and vibration of the TPV weatherstrip. With improved TPV material damping, the acceleration peak of frictional vibration decreased by about 57.9%. This finding can not only improve BSR performance of electric vehicles by designing material damping of weatherstrips but also contribute to various structural applications such as urban air mobility or aircrafts, which require lightweight and high damping properties.