• 제목/요약/키워드: Half Life

검색결과 1,829건 처리시간 0.035초

전류제어를 이용한 등기구 전원장치에 관한 연구 (A Study of Lighting Flxtures Power Supply That Use Current Control)

  • 이병선;김영선
    • 전자공학회논문지
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    • 제49권11호
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    • pp.199-204
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    • 2012
  • 지지구 온난화 등과 관련하여 에너지 개발과 절약에 대한 연구가 활발하다. 본 연구에서는 전체 전기에너지 사용의 19%를 차지하는 조명기구 소비전력의 효율적인 절감과 수명연장을 위해 주파수변조와 펄스폭 변조를 혼용한 전류제어 방식의 새로운 형태인 하프브리지형 전원장치를 제안한다. 제안한 전원장치가 갖는 우수성과 안정성에 대해 입증하고 그 특성을 분석 하였다.

"내경(內經)" 중심으로 경락(經絡)과 피부(皮膚)에 관한 연구(硏究) (The mutation research which with problem of the Spleen and the Stomach appears in skin care)

  • 김명주;전현정
    • 대한한의정보학회지
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    • 제14권2호
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    • pp.11-20
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    • 2008
  • This thesis' "Hwang Jae Nai Kyung(黃帝內經)", it is one among Uihak5kyung(醫學五經), is originally total of 18 volumes, the first half of 9 volumes are Somun(素問) and the latter half of the others are Youngchu(靈樞). Also, it is best of old book and literature integrating process of Chinese's medicine. Somun(素問) is comprehensive and extensive principles from fundamental problem of medical science related etiology, pathology, physiology to such parts of preventive medicine as regimen, recuperation. Moreover, therapeutic part of diagnosis and remedy, practice of acupuncture and moxibustion is recorded to Youngchu(靈樞). In the "Hwang Jae Nai Kyung(黃帝內經)", basic system takes precautions and medical cure for disease by approaching not method analyzing body but fundamentals of oriental medicine observed as organizing relation. For the purpose of mixing up beauty based on Buddhism of books, we shall pursuit notion of beauty treatment to method improving health because period flowing is changed to real well-being culture chasing outside beauty and healthy life. Then, to come close for part of oriental medicine and cosmetology, we shall present method of meridian pathways and understand device for cosmetic improvement by analyzing relation to 12 of pathways, the five viscera and the six entrails & skin.

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살충제 Carbofuran의 수중광분해 (Aqueous Photolysis of the Organophosphorus Insecticide Carbofuran)

  • 김균;김용화
    • 한국환경농학회지
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    • 제21권3호
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    • pp.172-177
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    • 2002
  • 살충제 carbofuran의 수중 광분해 실험을 미국 EPA 및 OECD 방법으로 수행하였다. Carbofuran은 자연광을 흡수하지 않는 화합물이지만, 야외에서 증류수로 수행한 광분해시험 결과 반감기가 9.7일, SUNTEST에서 3.4일, SUNTEST의 UV하에서 1시간으로 신속한 광분해가 일어남을 확인하였다. 특히 논물에서는 SUNTEST에서의 반감기가 14시간으로 증류수 보다 약 6배 가속화되었으며, 살균한 논물보다는 비살균 논물에서의 광분해가 다소 빠르게 일어났다. 이와 같은 결과로 볼 때 carbofuran의 경우 수도작 상황에서 sensitizer 등에 의한 간접 광분해의 가능성이 있음을 확인하였다.

하나로 유동 모의 설비의 유체순환계통 해석 (The Analysis for Flow Circulation System in HANARO Flow Simulation Facility)

  • 박용철
    • 한국유체기계학회 논문집
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    • 제7권1호
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    • pp.30-35
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    • 2004
  • The HANARO, a multi-purpose research reactor of 30 MWth open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. Many experiments should be safely performed to activate the utilization of the HANARO. HANARO flow simulation facility is being developed for the endurance test of reactivity control units for extended life time and the verification of structural integrity of those experimental equipments prior to loading in the HANARO. This facility is composed of three major parts; a half-core structure assembly, a flow circulation system and a support system. The flow circulation system is composed of a circulation pump, a core flow piping, a core bypass flow piping and instruments. The system is to be filled with de-mineralized water and the flow should be met the design requirements to simulate a similar flow characteristics in the core channel of the half-core structure assembly to the HANARO. This paper, therefore, presents an analytical analysis to study the flow behavior of the system. Computational flow analysis has been performed for the verification of system pressure variation through the three-dimensional analysis program with the standard $k-{\epsilon}$ turbulence model and for the verification of the structural piping integrity through the finite element method. According to the analysis results, it could be said that the design requirements and the structural piping integrity of the flow circulation system are satisfied.

디지털홈기기 사용실태에 관한 사례조사 연구 - 생활공간 중심으로 - (Analysis on Usage of Digital Home Appliance in Spatial Context)

  • 도윤희
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2004년도 추계학술발표대회 논문집
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    • pp.179-180
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    • 2004
  • In the information society, individual, enterprise and nation must be equipped with environmment and competence with which they can acquire useful information anytime and anywhere to process and utilize it in required form. Therefore, this study intends to investigate how digital TV, refrigerator and computer are laid out in the residential space in terms of life space, analyze the preference of residents an d forecast the preferred functions of the products to be introduced in the future. To build frame for making questionnaire tool of this survey, 3 households of the first constructor among the top-ranked constructors in the first half of 2004 were chose and in-depth interview was made from April 12 to April 17. On the basis of result of preliminary survey obtained by this process, the questionnaire was revised and supplemented. Targeting those living at the apartment house in Seoul and constructors ranked in top-four in the order of construction of the first half of 2004, I selected 3 households for each group in the range of 30$^{\sim}$40 pyung. Twelve cases were surveyed from April 19, 2004 to June 5, 2004. First, TV will continue playing the role of central entertainment mustering family at one place rather than separating them to each room. Second, in the case of refrigerator, the function is being subdivided, making 2 types, refrigerator and kimchi refrigerator indispensable, which was in just unit in the past Third, while computer was usually placed in the individual bedroom,

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오메프라졸과 $\gamma$-시클로덱스티린과의 복합체 형성 및 제제학적 특성 (Interaction between Omeprazole and $\gamma$-Cyclodextrin)

  • 이계주;김은영
    • 약학회지
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    • 제39권2호
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    • pp.175-184
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    • 1995
  • The interaction of omeprazole(OMP) with $\gamma$-cyclodextrin($\gamma$-CyD) was investigated by solubility study and the complexation was confirmed by means of UV/VIS spectrophotometer, circular dichroism, differential scanning calorimeter, and $^{1}$H nuclear magnetic resonance spectra. The stability, dissolution rate, and partition coefficient of the complex were measured. The results present that the benzimidazole moiety and a part of pyridine ring containing sulfur atom of OMP might be included into the cavity of $\gamma$-CyD and the formation type of inclusion complex appeared to be B$_{s}$. The stoichiometric ratio of OMP to $\gamma$-CyD in the complex was found to be 1:1 and the stability constant of the complex found to be 97.1 M$^{-1}$. And the dissolution rate of OMP was markedly increased by inclusion complex formation with $\gamma$-CyD, and so it was above 90% in 5 min. from solid complex. Oil to water partition coefficient of OMP-$\gamma$-CyD complex was 60, which is significantly higher than that of OMP itself, 36.4. The degradation rate constant of OMP were greater than OMP-$\gamma$-CyD complex in aqueous solutions of various pHs, and the half lives of OMP and OMP-$\gamma$-CyD at pH 9 were 279.2 and 509.9 days, respectively, showing that the complex was more stable than OMP, therefore it was thought that OMP was stabilized by inclusion formation with $\gamma$-CyD.

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철근콘크리트 보의 철근부식에 미치는 하중의 영향에 관한 연구 (Influence of Loading on the Corrosion of Reinforcing Bar)

  • 김형래;윤상천;지남용
    • 콘크리트학회논문집
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    • 제11권3호
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    • pp.171-179
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    • 1999
  • The present research investigated the interaction among loading level, corrosion rate and flexural deflection of reinforced concrete beams. 10cm$\times$15cm$\times$110cm reinforced concrete beams were prepared and subjected to different levels of flexural loading, including 0%, 45% and 75% of the ultimate load. The beams with either a pre-load or a sustained load were also exposed to a laboratory environment with ponding and wetting/drying cycling at room temperature. Half cell potential and galvanized current measurements were taken to monitor corrosion process of reinforcing steel. After corrosion initiation, external current was applied to some of the beams to accelerate corrosion propagation. The beam deflections were recorded during the entire tests. The results indicate that loading level has significant effect on corrosion rate. The beams under a sustained load had much higher corrosion rate than the pre-loaded and then unloaded beams. Significant corrosion may result in an increase in beam deflection and affect serviceability of the structure. The present research may provide an insight into structural condition evaluation and service life predictions of reinforced concrete.

조미식육 제품 개발에 대한 학교급식 영양사의 인식조사 -경남지역을 중심으로- (Dietitians' Perception on the Development of Processed Meats with Seasoning in School Foodservice Operations - Kyungnam Province -)

  • 이동선;류은순;이영순
    • 한국식품조리과학회지
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    • 제22권5호통권95호
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    • pp.573-582
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    • 2006
  • The perception and attitude of dietitians on processed meats with seasoning were investigated. Questionnaires were distributed to 176 dietitians at school foodservice operations in Kyungnam province. In the survey results, about half (Ed-better to give the exact number of percentage) of the dietitians answered that it is ‘necessary’ to develop processed meats with seasoning. Regarding desired product characteristics, the dietitians were asked about-reduced additive use, good hygienic quality, nutritious and healthy quality, low salt content and adequate supply of nutritional information. Over half of the dietitians-(65.5%) preferred Korean style processed meats with seasoning. The cooking types chosen as new developments for Korean processed meats with seasoning were grilled (36.2%), fried (19.8%), and roasted (18.6%). The dietitians wanted no or only a little increase in the price compared to current commercial products, 1kg (50.6%) size as the package unit and 7 days (45.1%) shelf life under refrigerated or frozen storage.(Ed-confirm the highlighted changes) A majority of the dietitians (64.2%) responded positively to buy the processed meats with seasoning if the products meet their needs.

Glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonists in the treatment of type 2 diabetes

  • Lee, Seungah;Lee, Dong Yun
    • Annals of Pediatric Endocrinology and Metabolism
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    • 제22권1호
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    • pp.15-26
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    • 2017
  • The prevalence of type 2 diabetes (T2D) is increasing worldwide. Patients with T2D suffer from various diabetes-related complications. Since there are many patients with T2D that cannot be controlled by previously developed drugs, it has been necessary to develop new drugs, one of which is a glucagon-like peptide-1 (GLP-1) based therapy. GLP-1 has been shown to ameliorate diabetes-related conditions by augmenting pancreatic ${\beta}-cell$ insulin secretion and having the low risk of causing hypoglycemia. Because of a very short half-life of GLP-1, many researches have been focused on the development of GLP-1 receptor (GLP-1R) agonists with long half-lives such as exenatide and dulaglutide. Now GLP-1R agonists have a variety of dosing-cycle forms to meet the needs of various patients. In this article, we review the physiological features of GLP-1, the effects of GLP-1 on T2D, the features of several GLP-1R agonists, and the therapeutic effect on T2D.

Change in radiation characteristics outside the SNF storage container as an indicator of fuel rod cladding destruction

  • Rudychev, V.G.;Azarenkov, N.A.;Girka, I.O.;Rudychev, Y.V.
    • Nuclear Engineering and Technology
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    • 제53권11호
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    • pp.3704-3710
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    • 2021
  • The characteristics of the external radiation on the surface of the casks for spent nuclear fuel (SNF) storage by dry method are investigated for the case when the spatial distribution of SNF in the basket changes due to the destruction of the fuel rod claddings. The surface areas are determined, where the changes in fluxes of neutrons, produced by 244Cm actinide, and γ-quanta, produced by long-lived isotopes, are maximum in the result of the decrease in the height of the SNF area. Concrete (VSC-24) and metal (SC-21) casks are considered as examples. The procedure of periodic measurement of the dose rate of neutrons or γ-quanta at the specified points of the cask surface is proposed for identifying the fuel rod cladding destruction. Under normal operation, the decrease in the dose rate produced by neutrons as the function of SNF storage duration is determined by the half-life of 244Cm, and for γ-quanta - by the half-lives of long-lived SNF isotopes. Consequently, a stepwise change in the dose rate of neutrons or γ-quanta, detected by the measurements, as compared to the previous one, would indicate the destruction of the fuel rod claddings.