• Title/Summary/Keyword: Low beta cavity

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Frequency and Length Adjustment of A PEFP Low-Beta Dumbbell

  • Changyi, Gao;An, Sun;Liping, Zhang;Yazhe, Tang;Yingmin, Li;Kim, Han-Sung;Cho, Yong-Sub
    • Progress in Superconductivity and Cryogenics
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    • v.10 no.2
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    • pp.27-29
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    • 2008
  • Superconducting RF cavities are being considered for accelerating a proton beam at 700 MHz in the linac of the Proton Engineering Frontier Project (PEFP) and its post-project. Dumbbell fabrication is a mid-process for manufacturing an elliptical superconducting RF cavity. During the dumbbell fabrication, control of the dumbbell length and the $TM010\;{\pi}$ mode frequencies is necessary to build up a desired cavity. A new formula with a perturbation measurement method is used to measure and calculate the frequencies of the individual half-cells of a PEFP low-beta dumbbell, and to tune the frequency and length of the half-cells. In this article, the tuning method and results of the PEFP low-beta dumbbells have been presented.

Production Enhancement of Menthol in Suspension Cultures of Peppermint Using Cyclodextrin (Peppermint 세포 현탁배양에서 Cyclodextrin을 이용한 Menthol의 생산성 증대)

  • 조규헌;임철호;박세춘;신명근
    • KSBB Journal
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    • v.13 no.1
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    • pp.26-30
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    • 1998
  • The suspension cultures of Mentha piperita produce menthol which has very low solubility in water due to its hydrophobicity. This can be considered as a factor for its low production in the suspension suspension cultures. Cyclodextrin has the hydrophobic cavity inside the molecule in which menthol can be captured and allow to form a stable complex. The suspension culture of Mentha piperita showed 70% higher production enhancement in the medium containing 1.5%(w/v) $\beta$-cyclodextrin than the control. $\beta$-cyclodextrin had no adverse effect on the cell growth and showed the best result among $\alpha$-, $\beta$- and $\gamma$-cyclodextrins tested in terms of menthol production. We demonstrated that $\beta$-cyclodextrin can be used to enhance the production of menthol in the suspension cultures by capturing hydrophobic menthol into the cavity of cyclodextrin molecules.

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Low beta superconducting cavity system design for HIAF iLinac

  • Mengxin Xu;Yuan He;Shengxue Zhang;Lubei Liu;Tiancai Jiang;Zehua Liang;Tong Liu;Yue Tao;Chunlong Li;Qitong Huang;Fengfeng Wang;Hao Guo;Feng Bai;Xianbo Xu;Shichun Huang;Xiaoli Li;Zhijun Wang;Shenghu Zhang;Jiancheng Yang;Evgeny Zaplatin
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2466-2473
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    • 2023
  • A superconducting ion-Linac (iLinac), which is supposed to work as the injector in the High Intensity heavy-ion Accelerator Facility project, is under development at the Institute of Modern Physics (IMP), Chinese Academy of Sciences. The iLinac is a superconducting heavy ion linear accelerator approximately 100 meters long and contains 96 superconducting cavities in two types of 17 cyromodules. Two types of superconducting resonators (quarter-wave resonators with a frequency of 81.25 MHz and an optimal beta β = v/c = 0.07 called QWR007 and half-wave resonators with a frequency of 162.5 MHz and an optimal beta β = 0.15 called HWR015) have been investigated. The cavity design included extensive multi-parameter electromagnetic simulations and mechanical analysis, and its results are described in details. The fundamental power coupler and cavity dynamic tuner designs are also presented in this article. The prototypes are under manufacturing and expected to be ready in 2023.

SRF LINAC FOR FUTURE EXTENSION OF THE PEFP

  • Kim, Han-Sung;Kwon, Hyeok-Jung;Seol, Kyung-Tae;Jang, Ji-Ho;Cho, Yong-Sub
    • Nuclear Engineering and Technology
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    • v.46 no.2
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    • pp.247-254
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    • 2014
  • A study on the superconducting RF linac is underway in order to increase the beam energy up to 1 GeV by extending the Proton Engineering Frontier Project (PEFP) 100-MeV linac. The operating frequency of the PEFP superconducting linac (SCL) is 700 MHz, which is determined by the fact that the frequency of the existing normal conducting linac is 350 MHz. A preliminary study on the beam dynamics showed that two types of cavities with geometrical betas of 0.50 and 0.74 could cover the entire energy range from 100 MeV to 1 GeV. An inductive output tube (IOT) based RF system is under consideration as a high-power RF source for the SCL due to its low operating voltage and high efficiency. As a prototyping activity for a reduced beta cavity, a five-cell cavity with a geometrical beta of 0.42 was designed and fabricated. A vertical test of the prototype cavity at low temperatures was performed to check the performance of the cavity. The design study and the prototyping activity for the PEFP SCL will be presented in this paper.

The Inclusion Complex Formation of Cyclodextrin and Congo Red in Aqueous Solution (수용액상에서 Cyclodextrin과 Congo Red 간의 복합체 형성)

  • Kim, Chang Suk;Kim, Dong Won;Bahn, Woo Kyoung
    • Analytical Science and Technology
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    • v.15 no.2
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    • pp.115-119
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    • 2002
  • The formation of inclusion complexes between cyclodextrin(CD) and Congo red was studied by spectrophotometric methods at various temperatures. The cavity sizes are 0.49 nm, 0.62 nm for $\alpha$-and $\beta$-CD, respectively. Therefore, $\alpha$-CD was not found to form an inclusion complex with Congo red due to steric hinderance. In the $\beta$-CD use two $\beta$-CD molecules formed an inclusion complex with one molecule of Congo red, from the slope of the S-shaped curve increased. Two prominent isosbestic points appear at 346 nm and 478 nm. The formation constants were decreased with the increasing temperatures, due to low binding energy between $\beta$-CD and Congo red. The thermodynamic parameters were calculated from the plot of $lnK_f$ vs 1/T. The $\Delta$H, $\Delta$S and $\Delta$G were -50.73 kJ/mol, $-108.96J/K{\cdot}mol$ and -18.26 kJ/mol, respectively.

Immobilization of MTBE using cyclodextrins

  • Baek, Ki-Tae;Yang, Ji-Won
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.120-123
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    • 2003
  • Immobilization behavior of methyl tert-butyl ether (MTBE) by various cyclodextrins(CDs) was studied to investigate the feasibility of MTBE removal using cyclodexrins. Even though MTBE has relatively low hydrophobicity and higher polarity compared to other organics, it was effectively immobilized by CDs. The immobilization isotherms was shown as a type of Freundlich isotherms, and the immobilization capacity of -CDs was the largest among natural COs. The initial apparent association constant for MTBE-CD complex follows the order : gamma = beta > methyl-beta > hydroxypropyl beta > alpha. These differences of the constants are related to the size of MTBE and CDs. The size of beta-CD and gamma-CD is large to encapsulate MTBE molecule into the cavity, which that of alpha-CB is too small to encapsulate MTBE.

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A study on Job and Duty Satisfaction of Dental Technicians (Focusing on employees in denture part) (치과기공사의 직업 및 직무만족도에 관한 연구 - Denture part 근무자를 중심으로 -)

  • Lee, Hwa-Sik;Bae, Bong-Jin;Han, Sok-Yoon
    • Journal of Technologic Dentistry
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    • v.34 no.4
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    • pp.391-402
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    • 2012
  • Purpose: This study was survey on future job vision and its pride (self-esteem) of dental technicians. It also investigates the future vision on their major of job (denture) and its awareness to improve the work environment and enhance their satisfaction towards job and duties. Methods: In order to research job and its duty satisfaction of dental technicians who mainly work at denture part, certified questionnaire was modified and upgraded for its use. Collected documents were used by 'Window SAS 8.0 Program' for analysis. The significance of the test related to the items and its standards has been decided for p<0.05. To find out the differences between choices when choosing career and the duty satisfaction, t-test, one-way ANOVA and two-way ANOVA have been used. Results: Following research findings show: 1. There was high self-esteem towards the job as dental technicians but low in future job vision. 2. It has been found that if satisfaction on their job (dental technician) is high then also their satisfaction on its duty (denture part) is high. 3. The factors that affects mostly on duty satisfaction of denture part are 'the contribution on improving oral cavity of people'(${\beta}$=0.33118), 'The possibility of growth of person's job choices'(${\beta}$=0.30035) and 'person's satisfaction on choosing job'(${\beta}$=0.16069). 4. If there is an increase level on the contribution of improving people's oral cavity, the possibility of growth of person's job choices and the person's satisfaction on choosing job, then there is also high growth in denture part's duty satisfaction. 5. It has been found that if there are more employment histories of denture part, the duty satisfaction of denture part were also high. On the other hand, the more employment history of dental technicians get, the duty satisfaction of their denture part was low. Conclusion: Following research results show that there is high self-esteem towards the job as dental technicians but the vision towards future was low. This shows that there is no bright future on dental technology. Therefore, it is important that not only to improve the work environment and pay rise on dental technologists but also to satisfy them. Various program developments and continuous research are needed to increase satisfaction.

Effects of Curcuma longa Rhizoma on MIA-induced Osteoarthritis in Rat Model (강황(薑黃)이 MIA 유도 골관절염 모델에 미치는 영향)

  • Kim, Young Jun
    • The Journal of Korean Medicine
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    • v.40 no.3
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    • pp.35-58
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    • 2019
  • Objectives: The aim of this study was to investigate the anti-inflammatory effects of Curcuma longa rhizoma extract in an experimental rat model of osteoarthritis. Methods: Osteoarthritis was induced in rats by injecting monosodium iodoacetate (MIA) into the knee joint cavity of rats. The rats were divided into 5 groups (Normal, Control, positive comparison, low (CL) and high (CH) concentration groups). Rats in the low concentration (CL) group had MIA-induced osteoarthritis; they were treated with Curcuma longa rhizoma extract at a dose of 50mg/kg body weight. Rats in the high concentration (CH) group had MIA-induced osteoarthritis; they were treated with Curcuma longa rhizoma extract at a dose of 100mg/kg body weight. Hind paw weight distribution and ROS levels were measured. At the end of all treatments, changes in alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and creatinine levels were analyzed. In addition, inflammatory protein levels were evaluated by western blot analysis. Results: In this study, hind paw weight distribution significantly improved in the CL and CH groups, while. Reactive oxygen species (ROS) production significantly decreased in both. The levels of ALT, AST, BUN, and creatinine did not significantly change in either group. The production of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4), $p47^{phox}$, and Ras-related C3 botulinum toxin substrate 1 (RAC1) decreased in both. Catalase, heme oxygenase-1 (HO-1) and superoxide dismutase (SOD) significantly increased in the CL and CH groups, respectively. Nuclear factor erythroid 2 (Nrf2) increased, but there were no significant differences between the experimental and control groups. Inflammatory cytokines, including nuclear factor-kappa Bp65 (NF-${\kappa}Bp65$), interleukin-1beta (IL-$1{\beta}$), and tumor necrosis factor-alpha (TNF-${\alpha}$), decreased significantly in both the CL and CH groups. Conclusions: Our results showed that Curcuma longa rhizoma extract has anti-inflammatory effects. Anti-inflammatory activity is regulated by the inhibition of inflammatory cytokines and mediators, such as NF-${\kappa}B$, therefore, it suppresses cartilage damage as well.

Reproductive Cycle of a Rockfish, Sebastes schlegeli (조피볼락의 생식주기)

  • BAEK Jae-Min;HAN Chang-Hee;KIM Dae-Jung;PARK Chul-Won;Aida Katsumi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.5
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    • pp.431-438
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    • 2000
  • To clarify the annual reproductive cycle in a rockfish, Sebastes schlegeli, monthly changes in gonadosomatic index (GSI), hepatosomatic index (HSI) and histological feature of gonads and plasma levels of sex steroid hormones ($estradiol-l7{\beta},\;17{\alpha},\;20{\beta}-dihydroxy-4-pregnen-3-one,\;testosterone\;and\;11-ketotestosterone$) were investigated. The annual reproductive cycle in females could be divided into 5 periods as follows: 1) recovery period (June to September): serum level of $estradiol-l7{\beta}$ increased gradually; 2) vitellogenesis period (Septemer to february) : vitellogenic oocytes were obsewed, GSI sustained high value, and serum level of $estradiol-l7{\beta}$ increased; 3) gestation period (February-April): developing larva showed in the ovary, and serum levels of $17{\alpha},\;20{\beta}-dihydroxy-4-pregnen-3-one$ and testosterone increased; 4) partrition period (April to May) : larva were delivered, and value of GSI and serum levels of hormones decreased rapidly; 5) resting period (May to June) : value of GSI and serum levels of $estradiol-l7{\beta}$ and testosterone remained low. The annual reproductive cycle in males could be divided into 6 periods; 1) early maturation period (April to June): value of GSI and serum levels of hormones incresed gradually, cyst of spermatogonia incresed in number, and a small number of cyst of spermatocyte was observed; 2) mid-maturation perid (June to September); value of GSI and serum levels of hormones increased, and germ cells in many cysts were undergoing active sperrnatogenesis; 3) late maturation period (September to November) : value of GSI and serum levels of hormones remained high and spermatozoa were released into the lumina of the seminal lobules; 3) spermatozoa dischaging period (Nobember to December) : the lumina of the seminal lobules were enlarged and filled with mature spermatozoa; 4) degeneration period (December to Februauy)i value of GSI decresed and cyst of spermatocyte were decresed in number; 5) resting period (December to April) : no histological changes of testes were observed, and value of GSI and serum levels of hormones remained low. In November, the lumina of the seminal lobules were filled with mature spermatozoa and sperm masses were present in the ovarian cavity. Thus, copulation in this species occurred in November and December.

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Wafer-Level MEMS Capping Process using Electrodeposition of Ni Cap and Debonding with SnBi Solder Layer (Ni 캡의 전기도금 및 SnBi 솔더 Debonding을 이용한 웨이퍼 레벨 MEMS Capping 공정)

  • Choi, J.Y.;Lee, J.H.;Moon, J.T.;Oh, T.S.
    • Journal of the Microelectronics and Packaging Society
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    • v.16 no.4
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    • pp.23-28
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    • 2009
  • We investigated the wafer-level MEMS capping process for which cavity formation in Si wafer was not required. Ni caps were formed by electrodeposition on 4" Si wafer and Ni rims of the Ni caps were bonded to the Cu rims of bottom Si wafer by using epoxy. Then, top Si wafer was debonded from the Ni cap structures by using SnBi layer of low melting temperature. As-evaporated SnBi layer was composed of double layers of Bi and Sn due to the large difference in vapor pressures of Bi and Sn. With keeping the as-evaporated SnBi layer at $150^{\circ}C$ for more than 15 sec, SnBi alloy composed of eutectic phase and Bi-rich $\beta$ phase was formed by interdiffusion of Sn and Bi. Debonding between top Si wafer and Ni cap structures was accomplished by melting of the SnBi layer at $150^{\circ}C$.

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