• Title/Summary/Keyword: Phase control method

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A Study on Low Power Energy Transfer Circuits of the Non Contact Method by means of Solar Generation (태양광 발전에 의한 비접촉 방식 저 전력 에너지 전송회로에 관한 연구)

  • Hwang, Lark-Hoon;Na, Seung-Kwon;Kim, Jong-Rae;Choi, Gi-Ho;Kim, Jin-Seon
    • Journal of Advanced Navigation Technology
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    • v.18 no.1
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    • pp.35-43
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    • 2014
  • In this paper, it is about to non-contact wireless power transmission according to various conditions of self induction principle between the two planar coils at a transmission unit and a receiving unit based on the theory of wireless power transmission. The experiments are occurred in order to power transfer of noncontact method from designed wireless circuits in the primely coil and secondary coil, and the applying to Half Bridge Resonant converter transmission unit and receiving unit. and that were able to prepared circumstance to calculate of the output voltage and power source. The main power of the inductive coupling the resonant converter at the transmission unit is converted electrical energy using the solar cell module and artificial light source (halogen lamp) as a replace light and received 24 V power supply from solar power was used a input power source for the wireless power transmission device. Experimental results, to received of power is used to illuminate the lighting and to charge the battery in receiving circuit.And the wireless power transmission efficiency measured at the output side of the transmission unit is obtained about 70% to 89% compared to input power of receiving unit.In addition, efficiency were tested through ID verification method and comparing the phase difference between the voltage when foreign substances interfere with wireless power transmission.

The Numerical Study on Effect of the Droplet Sizes on Internal Mass Transfer in the Spray Type Scrubber (분무형 스크러버에 내에서 액적크기에 따른 물질전달에 관한 전산해석적 연구)

  • Lee, Chanhyun;Chang, Hyuksang
    • Clean Technology
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    • v.25 no.1
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    • pp.19-32
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    • 2019
  • As regional air pollution gets worse by the sulfur oxides emitted from various types of vessels passing through the many countries, the International Maritime Organization establishes the emission control areas and regulates sulfur dioxide in those areas. In order to satisfy these regional regulations, the fuel selection method and the exhaust gas post-treatment device are applied to the ships. Due to the economic reasons, the post-treatment method of exhaust gas for reducing the amount of sulfur oxides discharged is mainly preferred. The scrubber which is dominantly used in the ships are the spray type system where the sprayed liquid drops used for capturing the soluble sulfur dioxides in the exhaust gas. The performance of the spray type system depends on the size distribution of the sprayed droplets. In order to evaluate this performance, we designed counterflow type scrubber and cyclone scrubber and evaluated the desulfurization efficiency and the amount of droplet evaporation according to the size of each droplet by using computational fluid dynamics. The Eulerian-Eulerian analysis method was used because the scrubber had a gas-liquid two-phase flow inside the scrubber. When the diameter of the droplet was $100{\mu}m$, $300{\mu}m$, $500{\mu}m$ and $700{\mu}m$. As a result, both of scrubbers showed high desulfurization efficiency and low evaporation amount at $500{\mu}m$ and $700{\mu}m$.

Determination of mandipropamid residues in agricultural commodities using high-performance liquid chromatography with mass spectrometry (고성능액체크로마토그래피를 이용한 농산물 중 Mandipropamid의 잔류분석법 확립)

  • Kwon, Chan Hyeok;Chang, Moon Ik;Im, Moo Hyeog;Choi, Hoon;Jung, Da I;Lee, Su Chan;Yu, Jin Young;Lee, Young Deuk;Lee, Jong Ok;Hong, Moo Ki
    • Analytical Science and Technology
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    • v.21 no.6
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    • pp.518-525
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    • 2008
  • Mandipropamid is a new mandelamide-type fungicide to control foliar Oomycete pathogens in some vegetables. An analytical method was developed to determine mandipropamid residues in agricultural commodities using high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS). Mandipropamid was extracted with methanol from grape, tomato, green pepper, Chinese cabbage and potato samples. The extract was diluted with saturated sodium chloride solution and distilled water, and dichloromethane partition was followed to recover the mandipropamid from the aqueous phase. Florisil column chromatography was employed to further remove interfering co-extractives prior to HPLC analysis. Reverse-phased HPLC was successfully applied to determine mandipropamid in sample extracts with the detection at its ${\lambda}_{max}$ (223 nm). Overall recoveries of mandipropamid from fortified samples averaged $99.8{\pm}1.7$ (n=6), $89.3{\pm}5.3$ (n=6), $98.7{\pm}2.2$ (n=6), $99.7{\pm}6.8$ (n=6) and $91.1{\pm}3.1$ (n=6) for grape, tomato, green pepper, Chinese cabbage and potato, respectively. Limit of quantification of the method was 0.02~0.04 mg/kg for all samples. A LC/mass spectrometry with selected-ion monitoring was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to determine the terminal residue of mandipropamid in agricultural commodities.

Relationship between Bone Morphological Microstructure and Inflammatory Markers in Growing Mice Fed a High Fat Diet (고지방식이 공급에 따른 성장기 마우스의 골의 형태학적 미세구조와 염증지표 변화)

  • Kim, Mi-Sung;Lee, Hyun-A;Kim, Ok-Jin;Sohn, Cheong-Min
    • Journal of Nutrition and Health
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    • v.44 no.6
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    • pp.481-487
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    • 2011
  • Obesity not only reduces bone mineral density but also increases inflammatory markers. Therefore, we examined the change in inflammatory markers and morphological microstructure of the bones using a mouse model fed a high-fat diet. C57BL/6J 4-week-old male mice were divided into a control group (n = 6) and a experimental group (n = 6); the control group was provided with 10% Kcal fat diet, and the high-fat diet group was provided with 45% Kcal fat diet for 12 weeks using the free provision method. Blood was analyzed for inflammatory markers, and micro-computed tomography was used to measure the morphological microstructure of the femoral bone. The weight increases in the control group and high-fat diet group were $5.85{\pm}1.84g$ and $16.06{\pm}5.64g$, respectively (p < 0.01), glucose was $115.00{\pm}16.88mg/dL$ and $188.33{\pm}13.29mg/dL$ (p < 0.01), and triglycerides were $65.00{\pm}6.19mg/dL$ and $103.33{\pm}8.02mg/dL$ (p < 0.05) respectively. Leptin and interleukin (IL)-6 were significantly higher in the high-fat diet group than that in the control group (p < 0.01). As a result of a biochemical index analysis of bone metabolism, osteocalcin tended to be lower in the high-fat diet group, whereas CTx was significantly higher in the high-fat diet group compared to that in the control group (p < 0.01). The thickness of the bony trabecula was significantly narrower in the high-fat diet group than that in the control group (p < 0.05), and the gap in the bony trabecula was significantly wider in the high-fat diet group than that in the control group (p < 0.05). IL-6 and the gap in the bone trabecula, which was a morphological microstructure of the bones, showed a positive correlation (p < 0.05). Taken together, inducing obesity through a high-fat diet in mice during the growth phase caused a change in bone microstructure and was correlated with the inflammation index. Accordingly, restriction of excessive fat intake may be needed to suppress the inflammatory reactions and promote normal bone formation.

Surface characteristics of thermally treated titanium surfaces

  • Lee, Yang-Jin;Cui, De-Zhe;Jeon, Ha-Ra;Chung, Hyun-Ju;Park, Yeong-Joon;Kim, Ok-Su;Kim, Young-Joon
    • Journal of Periodontal and Implant Science
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    • v.42 no.3
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    • pp.81-87
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    • 2012
  • Purpose: The characteristics of oxidized titanium (Ti) surfaces varied according to treatment conditions such as duration time and temperature. Thermal oxidation can change Ti surface characteristics, which affect many cellular responses such as cell adhesion, proliferation, and differentiation. Thus, this study was conducted to evaluate the surface characteristics and cell response of thermally treated Ti surfaces. Methods: The samples were divided into 4 groups. Control: machined smooth titanium (Ti-S) was untreated. Group I: Ti-S was treated in a furnace at $300^{\circ}C$ for 30 minutes. Group II: Ti-S was treated at $500^{\circ}C$ for 30 minutes. Group III: Ti-S was treated at $750^{\circ}C$ for 30 minutes. A scanning electron microscope, atomic force microscope, and X-ray diffraction were used to assess surface characteristics and chemical composition. The water contact angle and surface energy were measured to assess physical properties. Results: The titanium dioxide ($TiO_2$) thickness increased as the treatment temperature increased. Additional peaks belonging to rutile $TiO_2$ were only found in group III. The contact angle in group III was significantly lower than any of the other groups. The surface energy significantly increased as the treatment temperature increased, especially in group III. In the 3-(4,5-Dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide assay, after 24 hours of incubation, the assessment of cell viability showed that the optical density of the control had a higher tendency than any other group, but there was no significant difference. However, the alkaline phosphatase activity increased as the temperature increased, especially in group III. Conclusions: Consequently, the surface characteristics and biocompatibility increased as the temperature increased. This indicates that surface modification by thermal treatment could be another useful method for medical and dental implants.

A Design of Power Management IC for CCD Image Sensor (CCD 이미지 센서용 Power Management IC 설계)

  • Koo, Yong-Seo;Lee, Kang-Yoon;Ha, Jae-Hwan;Yang, Yil-Suk
    • Journal of IKEEE
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    • v.13 no.4
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    • pp.63-68
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    • 2009
  • The power management integrated circuit(PMIC) for CCD image sensor is presented in this study. A CCD image sensor is very sensitive against temperature. The temperature, that is heat, is generally generated by the PMIC with low efficiency. Since the generated heat influences performance of CCD image sensor, it should be minimized by using a PMIC which has a high efficiency. In order to develop the PMIC with high efficiency, the input stage is designed with synchronous type step down DC-DC converter. The operating range of the converter is from 5V to 15V and the converter is controlled using PWM method. The PWM control circuit consists of a saw-tooth generator, a band-gap reference circuit, an error amplifier and a comparator circuit. The saw-tooth generator is designed with 1.2MHz oscillation frequency. The comparator is designed with the two stages OP Amp. And the error amplifier has 40dB DC gain and $77^{\circ}$ phase margin. The output of the step down converter is connected to input stage of the charge pump. The output of the charge pump is connected to input of the LDO which is the output stage of the PMIC. Finally, the PMIC, based on the PWM control circuit and the charge pump and the LDO, has output voltage of 15V, -7.5V, 3.3V and 5V. The PMIC is designed with a 0.35um process.

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Preliminary Results of a Phase I/II Study of Simultaneous Boost Irradiation Radiotherapy for Locally Advanced Nasopharyngeal Carcinoma

  • Xiang, Li;Wang, Yan;Xu, Bing-Qing;Wu, Jing-Bo;Xia, Yun-Fei
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7569-7576
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    • 2013
  • Background: The purpose of this article is to present preliminary results of simultaneous boost irradiation radiotherapy for locally advanced nasopharyngeal carcinoma (NPC). Methods: Fifty-eight patients who underwent simultaneous boost irradiation radiotherapy for NPC in Cancer Center of Sun Yat-sen University between September 2004 and December 2009 were eligible. Acute and late toxicities were scored weekly according to the Radiation Therapy Oncology Group (RTOG) acute and late radiation morbidity scoring schemes. An especial focus was on evidence of post-radiation brain injury. Also quality of life was analysed according to the EORTC (European Organisation for Research and Treatment of Cancer) recommendations. Discrete variables were compared by ${\chi}^2$ test. The Kaplan-Meier method was used to calculate the survival rates and generate survival curves. Results: A total of 58 patients with a mean follow-up time of 36 months completed clinical trials.Fifty-seven patients (98.3) achieved complete remission in the primary sites and cervical lymph nodes, with only one patient (1.7%) showing partial remission.The most frequently observed acute toxicities during the concurrent chemoradiotherapy were mucositis and leucopenia. Four patients (6.9%) had RTOG grade 3 mucositis, whereas four patients (6.9%) had grade 3 leucopenia. No patient had grade 4 acute toxicity. Three (5.17%) of the patients exhibited injury to the brain on routine MRI examination, with a median observation of 32 months (range, 25-42months). All of them were RTOG grade 0. The 3-year overall, regional-free and distant metastasis-free survival rates were 85%, 94% and 91%, respectively. Conclusion: Simultaneous boost irradiation radiotherapy is feasible in patients with locally advanced nasopharyngeal carcinoma. The results showed excellent local control and overall survival, with no significant increase the incidence of radiation brain injury or the extent of damage. A larger population of patients and a longer follow-up period are needed to evaluate ultimate tumor control and late toxicity.

Polymorphic Variation of Inflammation-related Genes and Risk of Non-Hodgkin Lymphoma for Uygur and Han Chinese in Xinjiang

  • Gu, Xia;Shen, Yan;Fu, Ling;Zuo, Hong-Yun;Yasen, Halida;He, Ping;Guo, Xin-Hong;Shi, Yu-Wei;Yusufu, Muhabaiti
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9177-9183
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    • 2014
  • Polymorphisms of inflammation-related genes have been found to be associated with non-Hodgkin lymphoma (NHL) or some of its subtypes, but only a few relevant data have been reported in China. In this study, the Snapshot method was used to assess genetic variation; a total of 14 single nucleotide polymorphisms (SNPs) for 6 inflammatory factors in 157 NHL cases (64 Uygur ethnic subjects, 93 Han Chinese) and 435 controls (231 Uygur and 204 Han Chinese) were studied from the Xinjiang province of China. Haplotype distribution was estimated using PHASE 2.3 software. Statistical differences in the genotype and haplotype frequencies between case and control groups were also considered and estimated. For the Han population, the geneotype distributions for TNF-${\alpha}rs1800629$, TNF-${\alpha}rs1800630$, IL-6 rs1800795, IL-6 rs1800797, NF-KB1 rs1585215 and TLR-4 rs4986790 showed significant differences between the case and control groups (p<0.05). The TNF-${\alpha}$ gene frequencies of ACG and CCA haplotypes in the cases were higher than in the controls (OR=2.45, 95% CI: 1.55-3.89, p=0.0002, OR=2.53, 95% CI: 1.10-5.80, p=0.029, respectively), and the same findings were detected for TNF-${\beta}$ gene CA haplotype (OR=1.87, 95% CI: 1.21-2.90, p=0.0054). However, for the Uygur population, no such significant differences were detected within the gene-type distribution of the 14 SNPs. The TNF-${\alpha}$ gene frequency of the CCA haplotype between the two groups (OR=1.98, 95% CI: 1.11-3.51, p=0.021) revealed a statistically significant difference. Our results showed that polymorphic variations of inflammation-related genes could be important to the NHL etiology of the Han population, and that these may only have limited influence on the Uygur population.

Forsythia suspensa Extract Has the Potential to Substitute Antibiotic in Broiler Chicken

  • Han, X.;Piao, X.S.;Zhang, H.Y.;Li, P.F.;Yi, J.Q.;Zhang, Q.;Li, P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.4
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    • pp.569-576
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    • 2012
  • Two experiments were conducted to investigate the potential for Forsythia suspensa extract (FSE) to substitute for antibiotic in broiler chicken. First, a well-diffusion assay procedure and a 2-fold dilution method were used to determine the bacteriostatic activity of FSE on Escherichia coli K88, staphylococcus aureus, and salmonella was assayed. An inhibitory effect of FSE was observed on the growth of these bacteria. This effect seems to be dose depended, which disappeared after 25.00, 12.50, 1.56 mg/ml. Second, a 42-d trial with 252 broiler chickens (d 1, $38.7{\pm}1.1$ g BW) was conducted to evaluate the effect of dietary supplementation of FSE in broiler chicken. The feeding program consisted of a starter diet from d 1 to 21 and a finisher diet from d 22 to 42. Dietary treatments included were: i) NC: negative control fed a corn-soybean meal based diet; ii) PC: positive control group fed based diet with chlortetracycline; and iii) FC: a test group fed with 100 mg FSE/kg diet. In this study growth performance did not differ among treatments during the starter period. However, dietary supplemental chlortetracycline and FSE increased (p<0.05) average daily gain (ADG), average daily feed intake (ADFI) compared with NC during the finisher and overall phase. Apparent digestibility of calcium on d 21, digestibility of energy and calcium on d 42 of FC was greater (p<0.05) than NC. Moreover, cecal Escherichia coli counts for birds from FC were lower (p<0.05) than NC. Dietary FSE supplementation also improved (p<0.05) villus height and villus height to crypt depth ratios in both duodenum and ileum and decreased (p<0.05) crypt depth in the duodenum. Duodenum villus height and villus height to crypt depth ratio in both duodenum and ileum from the FC group were also greater (p<0.05). Serum growth hormone and IGF-1 were not influenced by different treatments. Apparently, FSE has the potential to substitute for antibiotic in broiler chicken.

Utilization of Peace Dam for Conservation Purpose (이수측면에서 평화의댐 활용방안 연구)

  • Yi, Jae-Eung;Lim, Dong-Sun;Lee, Jong-Tae
    • Journal of Korea Water Resources Association
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    • v.37 no.8
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    • pp.653-662
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    • 2004
  • In this study, the method of Increasing the flood control as well as conservation effects is studied by joint operation of Hwacheon and Peace Dam. After completing the second phase of the construction of the Peace Dam, the dam crest height will be increased from 225m and the storage capacity will also be increased. If storage capacity is increased and gates are installed, it will assist not only flood control but also conservation of the entire Han river basin. Considering the change of conservation levels, the change of the restricted water level of the Hwacheon Dam in flood season, and the inflow change into the Peace Dam through the simulated reservoir operation, the annual average power of Hwacheon Dam with 95% reliability, annual firm power, the volume of water supply is calculated. As a result, when the conservation level of the Peace Dam and the restricted water level of the Hwacheon Dam are increased, the generation capacity will be improved. However, even though the inflow decrease, the generation capacity will not be affected. If the inflow decrease under the same conditions, the water supply capability will be reduced to the range from 35% to 40%. It is necessary to increase conservation level to keep the same water supply capability.