• 제목/요약/키워드: L132

검색결과 564건 처리시간 0.031초

공기 중 광대역 초음파 방사용 압전 박막 기반 초소형 초음파 트랜스듀서의 설계 (Design of piezoelectric micro-machined ultrasonic transducer for wideband ultasonic radiation in air)

  • 안홍민;진재혁;문원규
    • 한국음향학회지
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    • 제39권2호
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    • pp.87-97
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    • 2020
  • 본 논문에서는 공기 중 광대역 초음파 방사용 압전 박막 기반 초소형 초음파 트랜스듀서(piezoelectric Micro-machined Ultrasonic Transducer, pMUT)의 설계 연구가 진행되었다. 하나의 트랜스듀서로 광대역을 달성하는 방법 중 하나는 다공진 시스템으로 설계하는 것이다. 새로운 pMUT은 박막 구조의 앞면과 뒷면에 적절한 음향 구조를 추가하여 다공진 시스템을 구현하도록 설계되었다. 박막 앞쪽은 도파관 구조로 모델링된 방사 파트로, 박막 뒷쪽은 음향 공동으로 모델링된 패키징 파트로 이루어져있다. 박막 파트, 방사 파트, 패키징 파트로 구성된 새로운 pMUT은 집중 변수 모델로 설계되었으며, 최종적으로 유한요소해석으로 검증되었다. 최종 설계된 pMUT은 102 kHz ~ 132 kHz (-3 dB)의 주파수 대역을 달성하였다.

중앙집중식 냉방시설의 냉각탑수중 레지오넬라균과 실내외 미생물 분포에 관한 연구 (Indoor and Outdoor Distribution of Legionella spp and Microbes on Cooling Towers Water of Central Air Conditioning Facilites)

  • 방선재;이철민;김윤신;선우영
    • 한국환경보건학회지
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    • 제28권3호
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    • pp.39-48
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    • 2002
  • Cooling towers water has frequently been known as a source of infection in outbreaks of Legionnaires' disease and a source of indoor air pollution. However, there have been a few reports on the presence of Legionella in cooling towers water and aerosols of various public facilities. This study was carried out to investigate the indoor and outdoor dis-tribution of Legionella spp and microbe from 132 cooling towers water of public facilities detected 1. pneumophila in Seoul and Gyeonggi-Do areas. The results showed that the Lpneumophila among the selected 132 cooling towers was detected mostly in July (12.0%), followed by August (4.0%) and June, September no-detected. The 1. pneumophiia in public facilities was detected mostly in department store (27.3%), followed by hospital (8.7%), office building (5.9%), big market (5.0%) and hotel, subway no-detected. The pH values of cooling towers water with presence of 1. pneumophila showed mostly 8.0 or higher (9.5%), followed by 7.0~8.0 (6.8%), lower 7.0 no-detected. The tem-perature of cooling towers water with presence of L pnemophila showed mostly 30℃ or higher (9.8%), followed by 26~30℃ (6.9%), lower 25℃ no-detected. The turbidity of cooling towers water with presence of 1. pneumaphila showed mostly 1-2 M (8.8%), followed by above 2 NTU (5.9%), lower 1 NTU no-detected. The correlation coef-ficient between indoor and outdoor concentration of microbes in public facilities showed 0.67 in Legionella spy. (p>0.05), 0.93 in bacteria (p<0.01), 0.94 in fungus (p<0.01), 0.98 in coilform (p<0.01), respectively.

한국 젊은 성인의 아연 영양 상태가 짠맛 인지와 기호도, 나트륨 섭취 및 혈압에 미치는 영향 (The Effect of Zinc Status on Salty Taste Acuity, Salty Taste Preference, Sodium Intake and Blood Pressure in Korean Young Adults)

  • 안은정;노화영;정자용;백희영
    • Journal of Nutrition and Health
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    • 제43권2호
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    • pp.132-140
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    • 2010
  • High sodium intake is one of the risk factors for the development of hypertension. According to 2007 Korean National Health and Nutrition Examination Survey, sodium intake of Korean was three times higher than adequate intake (1.5 g/day) recommended by Korean Dietary Reference Intakes. High sodium intake is related to high threshold and preference of salty taste. And zinc status is known to affect taste acuity. The hypothesis of this study is that zinc status is associated with salty taste acuity, preference, sodium intake and blood pressure. The subjects included in this study were 50 men and 41 women aged 20-29 y who did not smoke and not take supplements or medications regularly. Dietary intake data for 3 days were collected by 24-h recall for 1 day and dietary record for 2-days. Salty taste acuity and preference were determined by sensory test. Fasting serum concentration of zinc, height, weight, body composition and blood pressure data were collected. Salt taste preference in high zinc intake group ($\geq$ estimated average requirement, EAR; men-8.1 mg/day, women-7 mg/day) was higher than that in low zinc intake group (< EAR). Salty taste preference was inversely correlated with serum zinc concentration in people with low concentration of serum zinc (${\leqq}\;81\;{\mu}g/dL$)(r = -0.3520, p < 0.05). Diastolic blood pressure was higher in high sodium intake group than in low sodium intake group (p < 0.05), positively correlated with salty taste preference (r = 0.3866, p < 0.05) in subjects with daily zinc intake below the EAR. We conclude that low zinc status may be related to high salty taste preference and high blood pressure in Korean young adults.

Bacillus subtilus HR-1019와 N-Acetyl-thioproline으로 제조한 미생물처리제, BIOACTIVE에 의한 상추의 생장 촉진 (Growth Promotion of Lettuce by Biofertilizer, BIOACTIVE, Prepared from Bacillus subtilus HR-1019 and N-acetyl-thioproline)

  • 이용석;박동주;김재훈;김형석;정수열;최용락
    • 생명과학회지
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    • 제23권1호
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    • pp.79-83
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    • 2013
  • L-Cysteine에서 유도된 아미노산인 ATCA와 불용성 인산 가용화능을 가진 균주를 이용하여 미생물처리제 BIOACTIVE를 제조하고 안정성을 확인 하였다. 제조한 미생물처리제를 미생물 비료로 적용하고자 3회 관주 처리한 다음 상추모종의 생장촉진 효과를 조사하는 실험을 수행하였다. 그 결과로 처리한 시험 구에서 상추의 생육은 엽수, 엽장 및 엽중에서 최대 128%, 122% 및 153% 정도로 증가하였다. 처리 간에는 기준량(1,000배 희석) 처리> 반 량(500배 희석) 처리> 배 량(2,000배 희석) 처리 순으로 나타났다. 공시 BIOACTIVE의 처리가 토양 중의 유효인산 및 식물체내의 인산함량을 최대 118% 및 132% 정도 증가 시키는 경향이었다. BIOACTIVE제제를 처리했을 때 N, P, K 3요소를 관행으로 처리와 비슷한 생육 효과가 있는 것으로 보아 복합비료의 사용량을 줄여, 재배가 충분히 가능하리라 생각되며, 상추의 생육 및 비해 조사를 한 결과 본 관주 처리에서는 생육장해 및 비해는 없었다.

Polyoxygenated Flavones; Synthesis, Cytotoxicities and Antitumor Activity against ICR Mice Carrying S-180 Cells

  • Song, Gyu-Yong;Ahn, Byung-Zun
    • Archives of Pharmacal Research
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    • 제18권6호
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    • pp.440-448
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    • 1995
  • Fitty two flavones were synthesized from polyoxygenated dibenzoylmethanes which were obtained by a modified Baker-Venkatarman rearrangement, of 2-benzoyl oxyacetophenones. The following flavones among them showed good cytotoxic activities against L1210 and HL60 cells ; 2'-benzoyloxy-5,7-dimethoxyflavone $(8.2{\mu}g/ml,{\;}5.0 {\mu}g/ml)$, 2'-benzyloxy-5,7,8-trimethoxyflavone $(5,9 {\mu}g/ml,{\;}11.0{\mu}g/ml,{\;}2.7{\mu}g/ml)$, 2'-hydroxy-5,7,8-trimethoxyflavone $(9.8{\mu}/ml,{\;}6.2{\mu}g/ml)$, 2'-benzyloxy-5-hydroxyflavone $(5.2 {\mu}g/ml,{\;}3.6{\mu}g/ml)$, and 5,2'-dihydroxyflavone $(5.1{\mu}g/ml,{\;}4.0{\mu}g/ml)$. Presence of 5-methoxy group potentiated the cytotoxic activity, while the existence of 7-methoxy group decreased the activity. 5-Hydroxy or methoxy activates 4-carbonyl group, while 7-methoxy group deactivates the acrbonyl group. From these observation it was concluded that the activation of carbonyl group at C-4 of a flavone is important for the enahncement of the cytotoxic activity. The presence of both 5-hydroxy and 2-benzyloxy-or 2-hydroxy group enhanced the antitumor activity; 2'-benzyloxy-5-hydroxy-7-methoxyflaone 9T/C=144%), 5.2'-dihydroxy-7-methoxyflavone (T/C=132%) and 5,2'-dihydroxy-6,78,6' trtramethoxyflvone (T/C = 172%) 2'hexanolytion of 5,2'-dihydroxy-flavones did not improve the natitumor activity; 2' hexanoyloxy-5-hydroxy-7-methoxyflavone showed T/C = 132%, about the same as that of 5,2'-dihydroxy-7-methoxyflvone (T/C=130%)

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백화점 옥상공원의 계획요소 중요도 및 구성 공간과 시설에 대한 선호도 조사 (The Importance of Planning Elements and the Preferences for the Spaces and Facilities of Roof-Garden of Department Store)

  • 조재경;이민아
    • 한국실내디자인학회논문집
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    • 제23권1호
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    • pp.132-142
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    • 2014
  • The purpose of this study is to configure the spaces and elements of the roof-garden plan that users regard as important, and to investigate their preferred spaces and facilities, ultimately providing basic information for the planning of user-directed roof gardens for local residents. A questionnaire survey was used as the research method, targeting roof-garden users in the L department store of Jeollabuk-do. A total of 225 people responded to the questionnaire, and 223 of them were used for this study. The collected data was analyzed in SPSS ver.18.0, using frequency, percentage, t-test, and one way ANOVA. The respondents preferred rest space the most, followed by the convenient space, landscaping and green space, and play and exercise space. Teenage students preferred the pool and artificial spaces, such as a fountain, and planned convenient spaces and rest spaces, such as a playground. Cafes and restaurants, chairs and tables, and walking trails should be considered for single women in their twenties. Due to the high population of married couples in their thirties, the preference for play facilities and safety facilities was higher than in other groups. The well-educated population in their forties, when viewed from their preference for landscaping and green space, requires the opportunity to rest in nature. The results of this study cannot be generalized since the study was directed at roof-garden users in a department store in Jeollabuk-do. However, it is possible to provide specific information about the user-directed roof-garden plan, since the study was analyzed together with various user variables.

3차원 수치모의를 통한 저층수 배사관 내 유입된 사석의 배제 한계조건에 대한 연구 (A Study on the Exclusion Threshold Condition of the Riprap in the Bypass Pipe by 3D Numerical Simulation)

  • 박선빈;정석일;이승오
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2017년도 학술발표회
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    • pp.132-132
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    • 2017
  • 큰 하상계수를 가지는 국내 중소하천의 특성상 농업용수 등의 수자원 이용을 위해 국내에는 약 10,000개 정도의 하천 횡단구조물이 설치되어 있다. 그러나 느려진 유속으로 인하여 횡단구조물 상류에 유사가 퇴적될 확률이 높아지며, 이러한 유사는 부착된 오염물에 의한 수질 및 하상오염, 좁아진 유수단면적에 의한 통수능 저하로 발생하는 홍수위 증가 등 많은 위험성을 내포하고 있다. 이에 대한 해결책 중의 하나로 저층수 배사관(bypass pipe)을 활용하여 쌓여진 유사를 하류로 흘려보내는 방법이 있다. 저층수 배사관은 횡단구조물 상류와 하류의 하상을 연결하는 관으로써 상류와 하류의 수두차에 의해 흐름 특성이 결정된다. 하지만 배사관 내 사석이 유입되어 배제되지 않는 경우 배사관의 효율이 현저하게 저하될 가능성이 있다. 본 연구에서는 FLOW-3D를 이용하여 배사관내 사석이 유입되었을 때, 어떠한 조건에서 배제되고 배제되지 않는지를 명확히 하고자 한다. 하상이 평탄한 수로$(13.0(L){\times}5.0(B){\times}1.0(H)m)$를 재현하였으며, 배출관의 직경은 10cm로 결정하였다. 사석의 종류는 4가지(3cm, 5cm, 7cm, 9cm)로써 이를 고려하여 격자크기를 0.5cm로 결정하였다. 이는 사석의 구형형상이 충분히 잘 재현될 수 있는 격자크기이다. 모의 수행은 하류의 수위를 변화시켜가며 수행하였다. 저층수 배사관 내 유동 특성이 상류와 하류의 수두차에 의해 결정되기 때문에, 모의의 효율성을 위해 상류의 수위는 일정한 값으로 진행하였다. 모의 결과 수위차가 클수록 배제가 잘되는 경향을 보였다. 입자의 크기와 상하류 수위차를 무차원화 한 변수를 결정하였다. 분석결과 이 변수가 일정 값을 넘어서는 경우 배제가 되며, 반대로 이 값을 넘어서지 못한 경우 배제가 되지 않음을 확인하였다. 향후 다양한 관의 형상에 대해서도 배사관 내 한계조건을 도출하여, 저층수 배사관의 설계 및 시공에 도움이 되고자 한다.

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예비 간호인력 대상 다학제 전문직 간 교육 중재 연구의 체계적 문헌고찰: 동아시아권 국가 연구를 중심으로 (Systematic review on interprofessional education for pre-licensure nursing student in East Asia)

  • 임희진;김화인;김민지;이승은
    • 한국의료질향상학회지
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    • 제30권1호
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    • pp.132-152
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    • 2024
  • Purpose: This study aimed to identify and evaluate interprofessional education (IPE) interventions for healthcare professional students in East Asian countries. Methods: The reporting of this study followed the Preferred Reporting Items of Systematic Reviews and Meta-Analysis guidelines. A literature search was conducted using seven electronic databases: PubMed, EMBASE, CINAHL, Scopus, Web of Science, ERIC, and ProQuest Dissertations & Theses Global. Joanna Briggs Institute Critical Appraisal Checklists were also used to appraise the quality of the included studies. The outcomes of IPE interventions were classified based on a modified Kirkpatrick model. Results: This review included 30 studies predominantly conducted in Singapore, South Korea, and Taiwan. The prevalent research design was a one-group pre-posttest design, and most IPE interventions occurred as single events. Approximately 70% of the studies involved students from two healthcare professions, mainly nursing and medicine. Simulations, group discussions, and lectures have emerged as the most common teaching methodologies, with almost half of the studies leveraging a combination of these techniques. The IPE content primarily focused on interprofessional teamwork, communication, and clinical patient care situations; these included the management of septic shock. The effectiveness of the IPE interventions was mainly evaluated through self-reported measures, indicating improvements in attitudes, perceptions, knowledge, and skills, aligning with Level 2 of the modified Kirkpatrick model. Nonetheless, the reviewed studies did not assess changes in the participants' behavior and patient results. Conclusion: IPE interventions promise to enhance interprofessional collaboration and communication skills among health professional students. Future studies should implement rigorous designs to assess the effectiveness of IPE interventions. Moreover, when designing IPE interventions, researchers and educators should consider the role of cultural characteristics in East Asian countries.

Purification and Characterization of Antibacterial Peptides, Spodopsin Ia and Ib Induced in the Larval Haemolymph of the Common Cutworm, Spodoptera Iitura

  • 최정식;여성문;김웅석;채권석
    • Animal cells and systems
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    • 제1권3호
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    • pp.457-462
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    • 1997
  • Antibacterial activity was induced in the haemolymph of the common cutworm, Spodoptera litura by the artificial injection of E, coli Ek132. Antibacterial peptides were purified from the immunized haemolymph by heat treatment, ion-exchange chromatography, gel filtration chromatography, and reverse phase FPLC, and their physicochemical characteristics were investigated. These purified antibacterial peptides designated as spodopsin la and Ib were named after Spodoptera litura. Spodopsin la and Ib had the apparent molecular masses of 3, 823 Da and 3, 886 Da, respectively, and about 20% of the sequences had basic amino acids, such as lysine and arginine but no cysteine. Also, spodopsin l was confirmed to be a new member of cecropin family having a similar amino acid sequence to cecropin of lepidopteran insects, such as Bombyx mori and Hyalophora cecropia. The purified spodopsin was active against gram-positive as well as gram-negative bacteria.

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사서교사의 지위향상을 위한 일연구

  • 이춘택
    • 한국도서관정보학회지
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    • 제12권
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    • pp.97-132
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    • 1985
  • Many educators and teacher-librarians have emphasized many times on the necessity and the educational value of the school library. But actually the necessity and the educational value of the school library is not recognized as the most important ones in the educational system. Therefore I tried to find out several ways on the development of the school library and the promotion of the teacher-librarian focusing on recognition of the necessity of school library. In order to develop the school library, it is necessary that the function of the school library should be maximized and transformed to effective system. I would like to suggest the following methods : 1) Transform the present school library into the school library media center. 2) Connect the running system S.L.M.C. to the curriculum of the school. 3) Emphasis of the reading education. 4) Guidance on the use of library. At last I studied on the definition, the legal status and the education of the teacher-librarian.

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