• 제목/요약/키워드: Count rate

검색결과 862건 처리시간 0.033초

Development of Anticosmic Shielded Ultra Low Background Gamma Spectrometer for Precise Measurement of Environmental Radioactivity

  • Byun, Jong-In;Park, Yun-Ho;Kwak, Seung-Im;Hwang, Han-Yull;Chung, Kun-Ho;Park, Gun-Sik;Park, Doo-Won;Lee, Chnag-Woo
    • Nuclear Engineering and Technology
    • /
    • 제34권6호
    • /
    • pp.545-552
    • /
    • 2002
  • We developed an ultra low background gamma ray spectrometer particularly suitable for experiment which require lower detection limit. The background of a germanium spectrometer is suppressed by applying active and passive shielding technique at the same time. The active shielding devices consist of plastic scintillating plates of 50 mm thick and anti-coincidence electronic system. The shielding is made of 150 mm thick walls of very low activity lead,20 mm with activity of <10 Bq/kg and 130 mm with activity of <50 Bq/kg. The observed background count rates are 1.2 $s^{-1}$ and 0.36 $s^{-1}$ without and with the active shielding, respectively, overall the energy regions from 30 keV to 3 MeV The cosmic ray induced background is suppressed by a rate of 0.8 $s^{-1}$ at the present work. The detection efficiency curve necessary to obtain the radioactivity of environmental samples has been precisely determined on the energy regions from 80 to 2000 keV with a 10$^3$ ml marinelli beaker sample, consisting of the calibrated radionuclides $^{109}$ Cd, $^{57}$ CO, $^{139}$ Ce, $^{203}$ Hg, $^{113}$ Sn, $^{85}$Sr, $^{137}$ Cs, $^{60}$ Co and $^{88}$ Y. Virtues Of the method are demonstrated by measuring the activity of $^{137}$ Cs contained in the powdered milk.

배양세포의 성염색질에 관한 세포학적 연구 1. 배양기간을 달리한 고양이, 몰못트, 닭의 배양세포에 있어서의 성염색질에 대하여

  • 강영선;박상대
    • 한국동물학회지
    • /
    • 제8권2호
    • /
    • pp.37-41
    • /
    • 1965
  • The frequency and pattern of sex chromatin in primary cultured cells of kidney cortex of cats and guinea-pigs, and muscle of chick embroys were examined and compared to those of in vivo condition, with special reference to the various cultured stages. 1. In cat, the frequencies of sex chromatin positive I of peripheral position were average 62.7% in female, and 15% in male, whereas those of non-peripherla position were 5.8% in female and 0.1% in male. The incident proportion between them showed a marked difference-approximately 10 times higher in female than male. These results failry indicated that a distinct nuclear dimorphism with regard to the sex chromatin positive I was established in cultured cells. The position of sex chormatin was usually peripheral location. The tendency of frequencies , with reference to the cultured stages, was low count in primary extracted and initial stage cells , but it showed a peaked frequency in 10-13 days after primary culture, and after that the frequencies were decreased gradually. Compared between I vitro and in vivo condition of the same tissues, the cells in vivo exhibited the sex chromatin in high frequency at the peak showed stage. 2. In guinea-pig , the frequencyies of peripheral positive I were 36.8% in female and 6.3% in male, while non-peripheral positions were 6.1% in female and 3.5% inmale. Its incident was a rate of nearly 4 times higher in female than male. The nuclear dimorphism was also established in cultrued cells of guinea-pig. The position and the incident frquency showed a similar pattern as in cat except the primary extracted cells. 3. In chick embryo, the frequencies of sex chromatin positive I of peripheral position were 38.2% in female, and 18.3% in male, non-peripheral position, however, was hardly to find. These results suggest that the definite sexual dimorphism was unable to find in chick embryo cultured cells. The position and the incident tendency were a similar pattern as in above mammals and the frequency was higher in vitro cells.

  • PDF

6-[(N-4-플루오로페닐)아미노-7-클로로-5,8-퀴놀린디온의 in vivo 향진균 작용 평가 (The Evaluation of in Vivo Antifungal Activities of 6-[(N-4-Fluorophenyl)amino-7-Chloro-5,8-Quinolinedione)

  • 박윤미;김희정;김도희;이인경;김동현;유충규
    • 약학회지
    • /
    • 제40권1호
    • /
    • pp.90-94
    • /
    • 1996
  • 6-[(N-4-Fluorophenyl)amino]-7-chloro-5,8-quinolinedione(RCK3) was tested for antifungal activities, in vivo, against Candida albicans. RCK3 was compared with ketoc onazole and fluconazole in the treatment of systemic infection with Candida albicans in normal mice. The therapeutic potential of RCK3 had been assessed by evaluating their activities (survival rate) against systemic infections in normal mice. RCK3 had $ED_{50},\;8.78{\pm}0.18mg/kg$ but ketoconazole and fluconazole had $ED_{50},\;8.00{\pm}0.73,\;10.00{\pm}0.43mg/kg$ respectively. Intraperitoneally administered RCK3 at the $ED_{50}$, 8.78mg/kg for 7 days and 14 days reduced Candida albicans colony count in the kidneys and livers as well as ketoconazole and fluconazole at these $ED_{50}$, 8.00 and 10.00mg/kg. And administered RCK3 at the $ED_{50}$ for 14 days improved survival rates better than ketoconazole.

  • PDF

인동(忍冬)이 Monosodium Urate로 유발(誘發)된 백서(白鼠)의 통풍(痛風)에 미치는 영향(影響) (The Effect of Yindong on Gout of Rats induced by Monosodium Urate)

  • 이홍진;조충식;김철중
    • 혜화의학회지
    • /
    • 제17권1호
    • /
    • pp.83-93
    • /
    • 2008
  • In order to study the Effects of yindong(LC) on the variation of blood and joint value the gout induced by microcrystalline sodium urate in rats, for LC is one of the important medicine on gout. After pretreatment of LC(50, 500mg/kg) for 5days, the Effects of LC was evaluated on Serum albumin, Serum globulin, glutamate dxalacetate transminase(AST), glutanate pyruvate transminase(ALT), blood urea nitrogen(BUN), Serum creatitine, Serum uric acid, xanthine oxidase activity, Erythrocyte Sedimentation Rate(ESR), WBC, platelet were measured. The results were obtained as follows : Joint value Increase ratio was not significantly decreased in all LC taken groups compared with the control group. Serum albumin was significantly different in all LC taken groups compared with the control group and Serum globulin was significantly dicreased in 500mg/kgLC taken group compared with the control group. Serum AST, ALT were significantly dicreased in 500mg/kgLC taken group compared with the control group. Serum BUN was significantly decreased in all LC taken groups and Serum creatinine was significantly decreased in 500mg/kgLC taken group compared with the control group. Serum uric acid was significantly different in 500mg/kgLC taken group, and changes in xanthine oxidase activity was significantly decreased in 500mg/kg, 50mg/kgLC taken group. ESR was significantly decreased in all LC taken groups compared with the control group. WBC, platelet count were significantly decreased in 500mg/kgLC taken group compared with the control group. From above results it may be concluded that Yindong can be used for treatment and preventive medcine of gout induced by microcrystalline sodium urate in clinic.

  • PDF

주파수 상향변환 검출기를 이용한 1.5 ㎛ 통신파장대역의 단일광자 측정 (Single-photon Detection at 1.5 ㎛ Telecommunication Wavelengths Using a Frequency up-conversion Detector)

  • 김헌오;윤천주;조석범;김용수
    • 한국광학회지
    • /
    • 제22권5호
    • /
    • pp.223-229
    • /
    • 2011
  • 1.5 ${\mu}m$ 통신파장 대역 단일광자의 효율적인 측정을 위해서 PPLN WG(periodically poled $LiNbO_3$ waveguide)에서 준위상정합을 이용한 합주파수 생성에 의한 주파수 상향변환 검출기를 구성하고 검출 효율, 잡음 계수 및 타이밍 지터를 측정하였다. 974 nm에서 발진하는 펌프광의 세기가 300 mW일 때 최대 검출효율이 약 7%, 잡음 계수율은 약 480 kHz로 측정되었다. 피코초펄스 레이저를 이용한 자발적 매개하향변환에서 발생한 펄스형 단일광자 신호를 이용하여 측정된 주파수 상향변환 검출기의 최소 타이밍 지터는 약 39.1 ps였다. 또한 아주 좁은 동시계수 시간 폭으로 펄스형의 주파수 상향변환된 단일광자를 측정하면 잡음의 효과를 최소화할 수 있고, 신호대 잡음비의 특성을 최대로 높일 수 있다.

호중구감소환자의 식이제한 실태 (Survey on Dietary Restrictions for Neutropenic Patients)

  • 전옥경;임시은;정인숙;윤은영;김미현;박윤선;이수란
    • 종양간호연구
    • /
    • 제10권2호
    • /
    • pp.210-217
    • /
    • 2010
  • Purpose: This survey was aimed to examine the current dietary restrictions practices for neutropenic patients among hospitals with 500 and more beds. Methods: Self-administered questionnaires were sent to 100 head or charge nurses of oncology or hemato-oncology wards by mail during October 2009, and 51 questionnaires were returned. The data were analyzed with descriptive statistics using SPSS (WIN version 12.0). Results: Of the hospitals surveyed, 47.1% (n=24) had guidelines on the dietary restrictions, and 80.4% (n=41) placed patients with neutropenia on restricted diets. The major decisional criteria of the dietary restriction was absolute neutrophil count (30.5%) and cooking status (29.2%). The most commonly restricted foods were raw fish or fresh meat (98.0%), uncooked intestine (98.0%), raw eggs (98.0%), draught beer (96.1%), and fresh fruits or vegetables (86.3%). Conclusion: The results showed variation in pattern of dietary restrictions and lower rate of guideline among hospitals, so that the need for the standard dietary restriction guideline is high. However, the role of diet in the development of infection in neutropenic patients is still unclear, which makes it difficult to establish dietary restriction guideline. Therefore, additional research are required to identify the relationship between dietary factors and infections.

보호대상해양생물종인 잘피의 보전을 위한 해역이용협의의 사례연구 (A Case Study of the Sea Area Utilization Consultation for the Conservation of Marine Protected Seagrass Species)

  • 오현택;이용민;김혜진
    • 수산해양교육연구
    • /
    • 제28권4호
    • /
    • pp.957-970
    • /
    • 2016
  • This study diagnosed the status of marine environmental impact assessment(MEIA) for project near the habitat of marine protected seagrass species such as Zostera caespitosa, Zostera asiatica, Phyllospadix iwatensis. For the preparation of a marine environmental impact statement, different monitoring parameters are used without any specific guideline for the assessment of current status. And also, both tools and techniques for MEIA are needed to improve for implementing. The monitoring plans and parameters are not considered well with the accuracy of the environmental predictions and effectiveness of any applicable mitigation measures. This study suggested the reasonable standard of the MEIA for the conservation of the marine protected seagrass species which have the habitat located near affected area. The inshore seagrasses need to be monitored including shoot count based on the "No Net Loss of Seagrass" as part of the monitoring parameters to assess the status of marine environment of environmental impact statement. In a process of effect prediction, we suggested a concentration of 10 mg/L suspended solids which added by the new developmental project near seagrasses habitat, referring to study of overseas case. But a further study for an appropriate standard is necessary effectively. In a mitigating process, priority needs to be considered in order of avoidance, minimization, reduction, compensation. In a post-monitoring process, it is necessary to monitor the seagrass species abundance to identify the variation of b/a (before and after) project. And in a case of implementing transplantation, survival rate need to be included to determine a success of project.

Microscopic Evaluation and Analysis on the Tensile Strength of Hybridized Reinforcement Filament Yarns by the Commingling Process

  • Herath, Chathura Nalendra;Kang, Bok-Choon;Hwang, Beong-Bok;Min, Kyung-Ho;Seo, Jung-Min;Lee, In-Chul;Ruchiranga, Jayasekara Vishara;Lim, Joong-Yeon
    • Advanced Composite Materials
    • /
    • 제17권3호
    • /
    • pp.225-233
    • /
    • 2008
  • The analysis in this paper is focused on the pattern of mixing of filaments over a cross-section of hybrid yarns according to different combinations of reinforcement and matrix filament yarns through microscopic view. The volume content of filament in hybrid yarn cross-section was maintained at 50% for both reinforcement and matrix, and the hybrid yarns count at 600 tex throughout the experiments. It was observed from the experiments that diameters of reinforcement and matrix filaments have strong effects particularly on the pattern of mixing of filaments over a cross-section of hybrid yarns such that the hybrid yarns with more or less equal diameters of reinforcement and matrix filaments showed considerably even distributions over the hybrid yarn cross-section. This paper also investigates the possibility of hybridizing carbon/aramid, carbon/glass and aramid/glass matrices through the commingling process. In the experiment, several process parameters were selected and they include pressure, yarn oversupply-rate and different nozzle types. As a result of these experiments, it was concluded that the hybridized materials show better performance than individual reinforced filament yarns in terms of mechanical properties. For small tensile forces, the carbon/glass/matrix combination turned out to be good enough for general purpose applications.

스마트 건강 스크린-과학적 건강관리 (Smart Health Screen)

  • 정희영;최성훈;김희철;김대영
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2017년도 춘계학술대회
    • /
    • pp.595-597
    • /
    • 2017
  • 현대인들은 편리한 생활방식, 영양과잉, 운동부족 등으로 비만문제에 심각하게 노출되어 있다. 장수를 원하는 인간의 욕망이 클수록 비만문제는 중요한 사회문제가 되고 있다. 사람들은 비만을 개선하기 위해 동네 공원이나 산책로, 등산로 등을 걸으며 운동을 한다. 지자체는 주민들을 위해 산책로나 등산로에 운동표지판을 세워 각종 운동정보를 제공하며 운동을 권장한다. 그러나 기존의 운동 표지판은 붙박이 고정식이라 다양한 운동정보나 건강정보를 제공하지 못한다. 그래서 본 연구는 헬스케어 IT시대에 맞춰 스마트 헬스 스크린을 통한 과학적 운동관리를 제안한다. IT를 기반으로 한 스마트 헬스 스크린은 실시간으로 걸음수, 칼로리소모량 심박수 등의 운동정보를 제공한다. 스마트 헬스 스크린이 제공하는 체계적이고 과학적인 운동관리는 지역주민들에게 개개인에게 맞는 운동량과 강도를 조절할 수 있도록 도와준다. 더불어 특별한 비용 없이 걷기만으로도 건강관리와 비만관리가 가능하게 해준다. 우리의 연구가 비만해결에 작은 도움이 되길 바란다.

  • PDF

IEEE 802.11i 무선 랜 보안을 위한 AES 기반 CCMP 코어 설계 (A Design of AES-based CCMP core for IEEE 802.11i Wireless LAN Security)

  • 황석기;김종환;신경욱
    • 한국통신학회논문지
    • /
    • 제31권6A호
    • /
    • pp.640-647
    • /
    • 2006
  • 본 논문에서는 IEEE 802.11i 무선 랜 보안을 위한 AES(Advanced Encryption Standard) 기반 CCMP (Counter mode with CBC-MAC Protocol) 코어의 설계에 대해서 기술한다. 설계된 CCMP 코어는 데이터의 기밀성을 위한 CTR(counter) 모드와 인증 및 데이터 무결성 검증을 위한 CBC 모드의 동작이 두개의 AES 암호 코어로 병렬처리 되도록 설계되어 전체 성능의 최적화를 이루었다. AES 암호 코어에서 하드웨어 복잡도에 가장 큰 영향을 미치는 S-box를 composite field 연산 방식을 적용하여 설계함으로써 기존의 LUT(Lookup Table) 기반의 구현방식에 비해 게이트 수가 약 27% 감소되도록 하였다. 설계된 CCMP 코어는 Excalibur SoC 장비를 이용하여 H/W-S/W 통합 검증을 수행하였으며, 0.35-um CMOS 표준 셀 공정으로 MPW 칩으로 제작하고, 제작된 칩의 테스트 결과 모든 기능이 정상 동작함을 확인하였다. 설계된 CCMP 프로세서는 약 17,000개의 게이트로 구현되었으며, 116-MHz@3.3-V의 클록으로 안전하게 동작하여 353-Mbps의 성능이 예상되어 IEEE 802.11a와 802.11g 표준의 MAC 성능인 54-Mbps를 만족한다.