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단상 유도형 동기 전동기(LSPM)의 특성해석에 관한 연구
정대성,김승주,이진헌,최재학,이주,Jung, Dae-Sung,Kim, Seung-Ju,Lee, Jin-Hun,Choi, Jae-Hak,Lee, Ju 한국조명전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.3
가전분야에서의 전동기 효율향상을 통한 에너지 소비절감 효과는 상당히 크지만 이를 위한 전동기의 설계/해석 기술 확보가 아직은 미흡한 상태이다. 이에 따라 유도형 동기전동기가 제안되었지만, 유도형 동기 전동기는 유도전동기와 통기전동기의 특성을 동시에 가지고 있어, 해석 및 설계가 쉽지 않다. 따라서 본 논문에서는 기존의 냉장고 압축기용 전동기인 단상유도전동기를 대처할 수 있는 단상 유도형 동기전동기를 이용해 파라미터에 따라 특성이 어떻게 바뀌는가에 대해 서술하였다. 그에 따라 단상유도전동기의 정상상태 특성을 해석하고 제안모델의 성능을 기존모델과 비교하고 실험하여 해석결과의 신뢰성을 검증한다. 또한 본 논문에서는 제안모델의 기존 고정자 형상이나 권선 스팩을 유지하고 회전자의 형상이나 구조만을 변경시켜 성능향상을 도모하였다. 해석방법으로는 전자장 수치 해석적인 방법으로 널리 이용되고 있는 유한요소법(Finite Element Method : FEM)을 이용하였다. Electric motor efficient improvement from home appliance field is important to the effect reducing the energy consumption. But the electric motor design/analysis technology is still insufficient. Specially the electric motor design/analysis technology of satisfying characteristic of both the induction motor and the synchronous motor such as Line start permanent motor. Therefore the electric motor design/analysis technology is urgently demanded reliability. This paper proposes the sing1e-phase line-start permanent magnet motor to develop the motor it with be able to alternate the sing-phase induction motor it is a refrigerator compressor motor. The sing-phase induction motor is analyzed in the steady state. And we have a certification test to compare our single-phase line-start permanent magnet motor with the sing-phase induction motor. In order to improve the performance, the stator of the single-phase line-start permanent magnet motor is same as the stator of the sing-phase induction motor and changes the rotor form and has the permanent magnet. It used the Finite Element Method(FEM) which is widely used with electronic-magnetic field numerical analysis method.
Choi, Sun-Woo,Katoch, Akash,Kim, Jae-Hun,Kim, Sang Sub American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.20
<P>A novel approach to improving the reducing gas-sensing properties of <I>n</I>-type nanowires (NWs), by locally creating <I>p</I>–<I>n</I> heterojunctions with <I>p</I>-type nanoparticles (NPs), is proposed. As a model system, this work investigates the sensing behaviors of <I>n</I>-SnO<SUB>2</SUB> NWs functionalized with <I>p</I>-Cr<SUB>2</SUB>O<SUB>3</SUB> NPs. Herein, <I>n</I>-SnO<SUB>2</SUB> NWs demonstrate greatly improved reducing gas-sensing performance when functionalized with <I>p</I>-Cr<SUB>2</SUB>O<SUB>3</SUB> NPs. Conversely, such functionalization deteriorates the oxidizing gas-sensing properties of <I>n</I>-SnO<SUB>2</SUB> NWs. These phenomena are closely related to the local suppression of the conduction channel of <I>n</I>-type NWs, in the radial direction, beneath the <I>p</I>–<I>n</I> heterojunction by the flow of charge carriers. The approach used in this work can be used to fabricate sensitive reducing-gas sensors based on <I>n</I>-type NWs.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-20/am504164j/production/images/medium/am-2014-04164j_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am504164j'>ACS Electronic Supporting Info</A></P>
Realization of As-doped p-type ZnO thin films using sputter deposition
Choi, Hyung-Kyu,Park, Jang-Ho,Jeong, Sang-Hun,Lee, Byung-Teak Institute of Physics 2009 Semiconductor science and technology Vol.24 No.10
<P>Arsenic-doped p-type ZnO (p-ZnO:As) thin films were deposited by the magnetron sputtering technique. High-resolution low-temperature photoluminescence (PL) spectra of the films revealed emissions at 3.35 eV and 3.32 eV, representing the neutral-acceptor-bound exciton transition and the free electron to acceptor level transition. Electroluminescence spectra of the p–n diodes fabricated from the p-ZnO:As/n-GaN heterostructure showed UV emission at about 380 nm and yellowish visible lights centered at 600–650 nm, which resembled the PL spectrum of the ZnO:As layer. The p-type ZnO films with 1at% As grown at 500°C showed a hole concentration of 5 × 10<SUP>12</SUP>–7 × 10<SUP>13</SUP> cm<SUP>−3</SUP> after the deposition and 4 × 10<SUP>14</SUP>–1 × 10<SUP>16</SUP> cm<SUP>−3</SUP> after annealing at 600 °C in oxygen atmosphere. High-resolution x-ray photoelectron spectroscopy indicated that most of the As dopants occupy Zn sites within the ZnO:As films.</P>
Choi, Sung-Seen,So, Hun-Young Korean Chemical Society 2005 Bulletin of the Korean Chemical Society Vol.26 No.11
Fragmentations and ion-molecule reactions of ionized cyclohexane propionic acid and cyclohexane butyric acid were studied using FTMS and theoretical calculations. The difference in bond dissociation depending on the aliphatic chain length was investigated and mechanisms for the possible rearrangements depending on the aliphatic carbon length were suggested. The most abundant fragment ion of the ionized cyclohexane propionic acid was c-$C_6H_{11}CH_2\;^+$ formed from the molecular ion by the direct C-C bond cleavage, while that of the ionized cyclohexane butyric acid was c-$C_6H_9C(OH)=OH^+$ formed by rearrangement of the molecular ion from the acid to diol form and loss of propyl radical. Stabilities of the radical and distonic ions of $C_nH_{2n}O^{+\bullet}$ formed from the molecular ion were compared. Protonated molecules were dissociated into smaller ions by losing one or two water molecules. The $[nM + H]^+$, $[nM + H - H_2O]^+$, and $[nM + H - 2H_2O]^+$ with n = 2 and 3 were generated by solvation with the neutral molecules in the ICR cell at long ion trapping time.
The Effect of Sopungchungyoung-tang on Activity of CD4 T cell
Choi Young Jin,Kang Hee,Myung Eu Gene,Shim Bum Sang,Choi Seung Hoon,Kim Sung Hun,Ahn Kyoo Seok The Physiological Society of Korean Medicine and T 2004 동의생리병리학회지 Vol.18 No.2
Sopungchungyoung-tang (SCT) has been widely used in Korea as a treatment of atopic dermatitis. SCT consists of Talcum, Rehmannia glutinosa, Angelica sinensis, Paeonia lactiflora, Cnidium officinale, Ledebouriella divaricata, Schizonepeta tenuifolia, Scutellaria baicalensis, Glycyrrhiza uralensis, Mentha arvensis, Cordyceps cicadae. We examined the immunological effect of SCT in vitro. We studied about the effect of SCT on Th cells' differentiation. In the case of CD4 T cells under neutral condition where there was only rIL-2 stimulus, SCT inhibited IFN-γ secretion by 70-80 %. Likewise, SCT also inhibited the IL-4 secretion of neutral Th cells by 85-90 %. We also experimented with the polarized Th1 cells/ Th2 cells and their production of IFN-γ and IL-4, respectively. There also were inhibitory effects on the polarized cells like there was on neutral cells, they were not as strong on the polarized cells. Under Th1 polarized condition, SCT acted dose-dependently, while in Th2 cells, the IL-4 production was inversely proportional to the doses of SCT. From the current study, it can be concluded that SCT exerts inhibitory effects on cytokine production without interfering with immune cells' activity. The result that SCT inhibits IFN-γ and IL-4 confirms that it does have a effect on immunomodulation.
Sang Wook Kim,Yang Il Choi,Jung Suck Choi,Jong Joo Kim,Bong Hwan Choi,Tae Hun Kim,Kwan Suk Kim 한국축산식품학회 2011 한국축산식품학회지 Vol.31 No.3
We assessed the effects of single-nucleotide polymorphisms (SNPs) within the porcine fatty acid synthase (FASN) gene regarding meat quality and fatty acid composition in two pig populations: Korean native pigs (KNP) were crossed with Yorkshire (YS) F2, and KNP were crossed with Landrace (LR) F2. Direct DNA sequencing using eight KNP and eight YS pigs revealed two SNPs: c.265C>T (silent) in exon 4 and c.6545A>C (Asn→His) in exon 39. The frequency of the two SNPs was analyzed using the polymerase chain reaction-restriction fragment length polymorphism method in seven pig breeds and their association with meat quality traits and fatty acid composition was studied. In the KNP × YS F2 population, both SNPs were significantly associated with the level of monounsaturated fatty acids, including palmitoleic (C16:1) and oleic acid (C18:1) (pC was associated with intramuscular fat content in both populations. Our results indicate that variations in c.265C>T and c.6545A>C of the pig FASN can be used to select animals with better fatty acid composition and meat quality. Moreover, KNP was a useful breed for identifying genetic factors affecting meat quality and fatty acid composition and for producing high quality pork.