• 제목/요약/키워드: PM loss

검색결과 1,281건 처리시간 0.033초

Effect of loading time on marginal bone loss around hydroxyapatite-coated implants

  • Kim, Young-Kyun;Ahn, Kyo-Jin;Yun, Pil-Young;Kim, Minkyoung;Yang, Hong-So;Yi, Yang-Jin;Bae, Ji-Hyun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제39권4호
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    • pp.161-167
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    • 2013
  • Objectives: The objective of this study is compare the rate of marginal bone resorption around hydroxyapatite-coated implants given different loading times in order to evaluate their stability. Materials and Methods: The study was conducted retrospectively for one year, targeting 41 patients whose treatment areas were the posterior maxilla and the mandible. Osstem TS III HA (Osstem Implant Co., Busan, Korea) and Zimmer TSV-HA (Zimmer Dental, Carlsbad, CA, USA), which employ the new hydroxyapatite coating technique, were used. The patients were divided into two groups - immediate and delayed loading - and the bone level at the time of loading commencement and after one year of loading was measured using periapical radiography. Differences between the groups were evaluated using Mann-Whitney (${\alpha}$=0.05). Results: For all patients as a single group, the survival rate of the implants was 100%, and the mean marginal bone loss was $0.26{\pm}0.59mm$. In comparison of the differences by loading, mean marginal bone loss of $0.32{\pm}0.69mm$ was recorded for the immediate loading group whereas the delayed loading group had mean marginal bone loss of $0.16{\pm}0.42mm$. However, the difference was not significant (P>0.05). Conclusion: Within the limited observation period of one year, predictable survival rates can be expected when using immediately loaded hydroxyapatite-coated implants.

Thermal Analysis using Thermal Equivalent Circuit Analysis and Finite Element Method of In-wheel Motor (In-wheel 전동기의 열 등가회로 해석 및 유한요소해법을 이용한 열해석)

  • Kim, Kyu-Seob;Lee, Byeong-Hwa;Hong, Jung-Pyo;Nam, Hyuk
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.941-942
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    • 2011
  • A thermal equivalent circuit of IPMSM considering eddy current loss of PM and core loss of rotor is proposed. This thermal equivalent model is represented by the thermal resistances and thermal capacitances. In order to determine the factor of each parameter, a heating test is processed. Additionally, the eddy current loss of PM is calculated by a transient 3D finite element analysis. Finally, this thermal equivalent model is verified by a temperature test in a 25kW 12-pole/18-slot IPMSM with varying load.

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The Generating Characteristic Analysis of Permanent Magnet Machines with Multi-Pole Rotor Considering Losses (손실을 고려한 영구자석형 다극 기기의 발전특성해석)

  • Jang, Seok-Myeong;Choi, Jang-Young;Ko, Kyoung-Jin;Lee, Sung-Ho
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.47-49
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    • 2007
  • This paper deals with the generating characteristic analysis of permanent magnet (PM) machines with multi-pole rotor and 3-phase stator windings considering losses such as copper loss, iron loss and mechanical loss. First, using d-q transformation, dynamic equations of PM machines are established. And then, characteristic equations for losses, power and efficiency are also derived. On the basis of d-q dynamic equations and characteristic equations, dynamic simulation algorithm is achieved by the MATLAB/SIMULINK. The simulation results are validated extensively by finite element (FE) analyses.

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Relationships between Insensible Perspiration and Thermo Physiological Factors during Wearing Seasonal Clothing Ensembles in Comfort (쾌적한 상태에서 계절별 의복을 착용하고 있는 동안 불감증설과 온열 생리 요소들 간의 관련성)

  • Lee, Joo-Young;Choi, Jeong-Wha;Park, Joon-Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • 제31권12호
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    • pp.1700-1709
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    • 2007
  • The purpose of this study was to examine the relationships between thermo-physiological factors and the insensible loss of body weight(IL) of resting women wearing seasonal comfortable clothing. Air temperature was maintained at a mean of 22.5, 24.7, and 16.8 for spring/fall, summer and winter, respectively. We selected a total of 26 clothing ensembles(8 ensembles for spring/fall, 7 ensembles for summer, and 11 ensembles for winter). The results showed that 1) IL was $19{\pm}5g{\cdot}m^{-2}{\cdot}hr$ for spring/fall environment, $21{\pm}5g{\cdot}m^{-2}{\cdot}hr$ for summer, $18{\pm}6{\cdot}m^{-2}{\cdot}hr$ for winter(p<.001). 2) Insensible water loss through respiratory passage(IWR) showed the reverse tendency to IL. IWR was $6{\pm}1g{\cdot}m^{-2}{\cdot}hr$ for winter and $5{\pm}1g{\cdot}m^{-2}{\cdot}hr$ for summer. This difference was significant(p<.001). 3) The proportion of IWR out of whole insensible water loss(IW), had a mean of the mean 28% for summer and 38% for winter(p<.001). 4) In comfort, the heat loss by IW out of heat production had a mean of 25% for spring/fall, 27% for summer, and 23% for winter. 5) There was a weak negative correlation between It and clothing insulation/body surface area covered by clothing. 6) There were significant correlations between IL and air temperature$(T_a)$, air humidity$(H_a)$, energy metabolism, ventilation, mean skin temperature $\={T}_{sk})$ and clothing microclimate humidity$(H_{clo})$. However, the coefficients were less than 0.5. In conclusion, there were weak relationships between the IL and thermo-physiological factors. However, when subjects rested in thermal comfort, the IL was maintained in a narrow range even though the clothing insulation and air temperature were diverse.

Immediate Effect of Hemodialysis on Pulmonary Function and Bronchodilator Response in Patients with Chronic Renal Failure (만성신부전 환자에서 혈액투석이 폐기능 및 기관지확장제에 대한 반응에 미치는 영향)

  • Jeon, Ho Seok;Lee, Yang Deok;Cho, Yongseon;Han, Min Soo
    • Tuberculosis and Respiratory Diseases
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    • 제56권1호
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    • pp.77-84
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    • 2004
  • Background : We hypothesized that there was a relationship between body weight change and bronchodilator response (BDR) in patients with chronic renal failure (CRF) on hemodialysis (HD). Several mechanisms such as pulmonary edema due to water retention or increased permeability of alveolar capillary may play a important role in pulmonary function impairment and bronchial hyperresponsiveness in patients with CRF on HD. But, no studies have been published concerning BDR in patients with CRF on HD. This study was aimed to know the immediate effect of hemodialysis on pulmonary function and BDR in patients with CRF on HD. Methods : This study included 30 patients with CRF on HD. We collected data including age, sex, height, pretibial and pedal pitting edema, interdialysis weight gain, postdialysis weight loss, underlying diseases, duration of HD, $FEV_1$, FVC, $FEV_1/FVC$, and BDR before and after HD. Results : Interdialysis weight gain of the patients was $3.4{\pm}1.0kg$, and postdialysis weight loss was $3.2{\pm}0.7kg$. Before HD,$FEV_1$, FVC, and $FEV_1/FVC$ of the patients were $89{\pm}22%$, $86{\pm}19%$ of predicted, and $87{\pm}10%$. After bronchodilator inhalation, these parameters were changed to $95{\pm}22%$, $90{\pm}19%$ of predicted, and $88{\pm}9%$ respectively. BDR was positive in 15 patients. After HD, $FEV_1$, FVC, and $FEV_1/FVC$ of the patients were $100{\pm}23%$, $94{\pm}18%$ of predicted, and $88{\pm}11%$. After bronchodilator inhalation, these parameters were changed to $102{\pm}23%$, $96{\pm}18%$ of predicted, and $89{\pm}8%$ respectively. BDR was positive in 9 patients. Conclusion : First, HD increases $FEV_1$, FVC, and $FEV_1/FVC$ but little affects BDR. Second, there is no correlation between postdialysis weight loss and increases in $FEV_1$, FVC, and $FEV_1/FVC$ after HD. Third, there is also no correlation not only between interdialysis weight gain and BDR before HD but between postdialysis weight loss and BDR after HD.

A Study on the Metabolism of Riboflavin in Korean Men (한국인 성인남자의 리보플라빈 대사에 관한 연구)

  • 황금희
    • Journal of the Korean Society of Food Science and Nutrition
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    • 제23권4호
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    • pp.594-603
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    • 1994
  • This study investigate the balance and biochemical status of riboflavin in Korean men. During the experimental period, four riboflavin diets with different levels of riboflavin(0.4, 0.6,0.8 and 1.0mg/1000kcal) were followed by eight healthy college men. the riboflavin status was assayed by erythrocyte glutathine reudcctase activity coefficient (EGRAC0 and urinary excretion of riboflavin. Riboflavin intake of the subjects who consumed a det was 0.46mg/1000kcal. the riboflavin intakes of the subjects who consumed the experimental diet with 0.4, 0.6, 0.8 and 1,0mg/1000kcal of riboflavin were 0.41, 0.60, 0.81 , 0.97mg, respectively. Fecal riboflavin loss, absorbed riboflavin , urinary riboflavin loss and retained riboflavin increased in the subjects consumed 0.4, 0.6, 0.8 and 1.0mg/1000kcal of riboflavin. The average EGRAC values for the subjects consumed 0.4, 0.6, 0.8 and 1.0mg/1000kcal of riboflavin were 1.303$\pm$0.029, 1.271$\pm$0.022, 1.239$\pm$0.013, 1.202$\pm$0.030, respectively and urinary riboflavin values ($\mu\textrm{g}$/g creatinine) were 86.89$\pm$ 20.07, 123.88$\pm$ 15.88, 240.70$\pm$57.14 and 393.36$\pm$76.94, respectively. Results indicate that 0.6mg/1000kcal is the level of riboflavin intake needed to maintain urinary riboflavin within the normal range. And above1.0mg/1000kcal of riboflavin is need to maintain urinary riboflavin with in the normal range. And above 1.0mg/1000 of riboflavin is needed to maintain the EGRAC within the normal range. The riboflavin intake correlated positively with urinary riboflavin value, but correlated negatively with the EGRAC value. The EGRAC value correlated negatively to protein intake as well as animal protein intake. The linear equation of between riboflavin intake and EGRAc was EGRA=-0.1667 $\times$riboflavin intake +1.3710. The riboflavin intake to maintain EGRAc below 1.20 was calculated 1.02mg/1000kcal by the above equation.

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Effects of Vibration Stress on the Quality of Packaged Apples during Simulated Transport

  • Jung, Hyun-Mo;Park, Jeong-Gil
    • Journal of Biosystems Engineering
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    • 제37권1호
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    • pp.44-50
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    • 2012
  • Purpose: The characteristics of in-transit vibration stress and possible damage to packaged apples were examined. Methods: A simulated transportation environment with a specific power density profile was used for vibration impact experiments to determine the resulting decrease in packaged apple quality. Apples with or without vibration stress were stored at low temperature ($5{\pm}0.8^{\circ}C$, 75-85% relative humidity) for 30 days. Statistically significant differences (p ${\leq}$ 0.05) were found between apples with and without vibration stress for concentration of oxygen ($O_2$; 11.2% and 14.1%, respectively; initially $29{\pm}0.4%$), carbon dioxide ($CO_2$; 26.4% and 21.8%; initially $1{\pm}0.2%$), and ethylene (79.4 ${\mu}LL^{-1}$ and 55.6 ${\mu}LL^{-1}$; initially $14.1{\pm}0.6{\mu}LL^{-1}$) in the headspace of a gas-collecting container after 30 days of storage. Results: Significant differences were also measured for apples with and without vibration stress with respect to soluble solid content (15.4% and 14.9%, respectively; initially $12.9{\pm}0.8%$ and $13.1{\pm}1.1%$), weight loss (10.1% and 8.2%), and firmness (139.7 kPa and 163.3 kPa; initially $213.8{\pm}6.2$ kPa and $209.1{\pm}7.9$ kPa) after 30 days of storage. Conclusions: The vibration stress clearly accelerated the degradation of apple quality during storage, resulting in increased weight loss, soluble solid content, and headspace $CO_2$ and ethylene production, and decreased firmness and headspace $O_2$.

Fiber Interferometers Based on Low Loss Fusion Splicing of Photonic Crystal Fibers (저손실 융착접속을 이용한 광자결정 광섬유 간섭계)

  • Ahn, Jin-Soo;Kim, Gil-Hwan;Lee, Kwan-Il;Lee, Kyung-Shik;Lee, Sang-Bae
    • Korean Journal of Optics and Photonics
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    • 제21권5호
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    • pp.200-205
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    • 2010
  • We report temperature and strain sensing characteristics of two kinds of in-line fiber interferometers. One interferometer consists of a section of Hollow Optical Fiber(HOF) spliced between two Photonic Bandgap Fibers(PBGF) and the other is built by splicing a section of HOF between two Large Mode Area-Photonic Crystal Fibers(LMA-PCF). To minimize the splice losses, we carefully optimized the heating time and arc current of the splicer so as not to collapse the air holes of the fiber. It is found that the first interferometer has a temperature sensitivity of 15.4 pm/$^{\circ}C$ and a strain sensitivity of 0.24 pm/${\mu}\varepsilon$. The other interferometer exhibits a temperature sensitivity of 17.4 pm/$^{\circ}C$ and a strain sensitivity of 0.2 pm/${\mu}\varepsilon$.

Effect of Storage Temperature and Humidity on the Quality Stability of Chestnuts (밤의 품질안정성에 대한 저장 온.습도 조건의 영향)

  • Gwon, Jung-Ho;Choe, Jong-Uk;Byeon, Myeong-U
    • Food Science and Preservation
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    • 제5권1호
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    • pp.7-12
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    • 1998
  • Chestnuts(Castanea cretana, Eunki) were used for quality evaluations from the physiological and physicochemical points of view during storage under different temperatures and relative humidities for 8 months. Quality criteria included spouting, rotting, weight loss, and the changes in moisture, total sugar, reducing sugar, and total vitamin C of the stored sample. Sprouts(roots) were developed in about 2 months in all stored samples which had been mixed with sawdust(50% moisture) and stored under the conditions of 2∼25$^{\circ}C$ and 62∼95% RH. The sprout development was more significant in the storage temperature of Pit(9${\pm}$6$^{\circ}C$, 80${\pm}$5% RH, PT)and room(16${\pm}$7$^{\circ}C$, 85${\pm}$10% RH, RT) than low(3${\pm}$1%, 80${\pm}$5% RH, LT)and ambient(14${\pm}$11$^{\circ}C$, 67${\pm}$5% RH, AT). The rates of rotting and weight loss were appreciable in the order of PT, AT, RT and LT, and those of LT were 1∼2%. The use of wet sawdusts resulted in the increase of moisture contents in stored samples, thereby causing the rotting phenomena. Some chemical components of stored samples were found liable to the changes according to storage conditions, that is; total sugars showed a decreasing tendency along with a temporary increase during storage, and both reducing sugar and vitamin C were similarly accumulated in the samples stored at low temperature conditions. The results indicated that long-term storage of chestnuts will be possible in either cases of the application of low temperature following sprout-inhibition treatment or the use of lower temperature than 0$^{\circ}C$ to suppress its sprouting during storage.

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Low-Dose Aprotinin Effect on Hemostasis After Cardiopulmonary Bypass (체외 순환후 지혈에 대한 저농도의 Aprotinin 효과)

  • Lee, Seon-Hui;Choe, Seung-Ho;Gwak, Mun-Seop
    • Journal of Chest Surgery
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    • 제29권2호
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    • pp.185-190
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    • 1996
  • The effect of low-dose aprotinin on hemostasis in patients undergoing cardiopulmonary bypass (CPB) for repeat valve replacement and coronary artery bypass operations were investigated. Thirty patients undergoing elective CPB from February 1993 through February 1995 at Catholic Medical Center were studied. the patients were randomly divided into two groups(15 patients per group) : group 1, receive 1, 000, 000 KIU/kg aprotinin in the CPB priming volume and 20, 000 KIU/kg aprotinin intravenously each hour during CPB ; group 2, without aprotinin administration served as the controls. The result showed that the early postoperative (during the first 24 hours) and mean postoperative total blood loss of the aprotinin group were significantly reduced than the control group (317.2 $\pm$ 89.6ml in the aprotinin group versus 821.3 $\pm$ 441.2rnl in the control group, p<0.01 ; 767.2 $\pm$ 214.1 ml in the aprotinin group versus 1562.5 $\pm$ 735.2 rnl in the control gorup, p<0.01). Total use of packed red ells and fresh frozen plasma was higher in control group(1.22 $\pm$ 0.3 units versus 4.21 $\pm$ 1.7units of packed red cells, p<0.01 : and 2.37 $\pm$ 0.4units versus 6.72 $\pm$ 0.88uni1s of fresh prozen plasma, p<0.05). We conclude the low-dose aprotinin was positive influence on postoperative blood loss in undergoing highly bleeding potency cardiac operation.

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