• 제목/요약/키워드: CAS-4

검색결과 283건 처리시간 0.031초

고도단계유입폭기법과 표준활성슬러지법의 처리특성 비교 (A Study of the comparison of the treatment characteristics between ASA system and CAS system)

  • 강용태;조용현;한상윤
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2007년도 춘계학술발표논문집
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    • pp.112-115
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    • 2007
  • Currently an increase in domestic sewage and industrial wastewater causes serious water pollution in Korea. To solve water pollution problems, conventional activated sludge (CAS) system is generally used in wastewater treatment plant but this process is so ineffective in nitrogen and phosphorus. Even if CAS system is the major process, it must be improved instantly so as to remove nitrogen and phosphorus. Otherwise, the serious water pollution problems can't be resolved with CAS system. Therefore this study focused on the comparison of the treatment characteristics between ASA system and CAS system. And also the mass balance of each process of ASA system. The results from operating advanced step aeration (ASA) system indicated that the removal efficiency of BOD, COD, and SS was 89.9%, 74.5%, and 89.0% respectively. In comparison, the removal efficiency of BOD, COD, and SS for CAS system was 89.5%, 71.8%, and 89.5% respectively. In addition to the results, the TN removal efficiency of ASA system was 76.5% comparing to 32.7% of CAS system. It was concluded that the TN removal efficiency of ASA system was 44% higher than CAS system. And the TP removal efficiency was 81.4% in ASA system comparing to 25.2% in CAS system. It also means that over 56% of TP was removed in ASA system comparing to CAS system.

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Assessment of dentists' subjective satisfaction with a newly developed device for maxillary sinus membrane elevation by the crestal approach

  • Kim, Young-Kyun;Cho, Yong-Seok;Yun, Pil-Young
    • Journal of Periodontal and Implant Science
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    • 제43권6호
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    • pp.308-314
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    • 2013
  • Purpose: The purposes of this study were to assess the dentists' subjective satisfaction with the crestal approach sinus (CAS) kit, a device for maxillary sinus membrane elevation by the crestal approach using a special drilling system and hydraulic pressure, and to summarize the subjective satisfaction of dental implants placed after a sinus lift procedure with the CAS kit. Methods: Thirty dental clinicians who had experience with dental implant placement after a sinus lift procedure with the CAS kit from June 2010 to May 2012 were included in this study. The questionnaire for the evaluation of the dentists' subjective satisfaction with the CAS kit was sent to the respondents and returned. The questionnaire was composed of two main parts. The first part was related to the sinus membrane perforation rate. The second part was related to the dentists' subjective satisfaction with the CAS kit. Results: A total of 28 dentists answered the questionnaire. Among 924 implant cases, sinus membrane perforation occurred in 38 cases (4.1%). Among the 28 dentists, 26 dentists (92.9%) were satisfied or very satisfied with the CAS kit. In particular, 24 dentists (85.7%) reported that safety, cutting performance, and user-friendliness of the CAS drill were advantages of the CAS kit. However, 7 dentists (25%) did not routinely use the hydraulic lifter for sinus membrane elevation. Conclusions: From the survey, it was shown that the respondents were generally satisfied with the CAS kit and that the cutting performance and safety of the drill component were considered strengths of the CAS kit.

농림위성용 GCP 칩 매칭 성능 향상을 위한 위성영상 공간해상도 결정 (Determination of Spatial Resolution to Improve GCP Chip Matching Performance for CAS-4)

  • 이유진;김태정
    • 대한원격탐사학회지
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    • 제37권6_1호
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    • pp.1517-1526
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    • 2021
  • 최근 국내외에서 많은 지구관측위성들이 발사됨에 따라서 위성영상의 활용 분야가 넓어지고 있고 이에 따라서 위성영상의 기하정확도 향상을 위한 연구가 활발히 수행되고 있다. 본 논문은 2025년에 발사예정인 5 m 해상도 영상을 촬영할 수 있는 농림위성을 위한 자동기준점 추출 가능성을 파악하기 위해서 수행되었다. 특히 본 연구에서는 국토위성용으로 구축된 25 cm 해상도의 지상기준점 Chip을 농림위성영상에 사용할 수 있는지를 검토하고 농림위성영상용 지상기준점 추출 시 정합 성능 향상을 위한 적절한 공간해상도가 있는지를 검토하고자 한다. 실제 실험은 농림위성영상과 유사한 사양을 가진 RapidEye 위성영상을 활용하여 연구를 수행하였다. 먼저, 5 m 해상도의 원본 RapidEye 영상을 3배~7배로 분할하여 여러 해상도를 가진 영상으로 만들고, 해상도를 가지는 지상기준점 Chip은 크기를 축소하여 위성영상의 해상도에 맞게 조절하였다. 각각의 해상도를 가지는 위성영상과 지상기준점 Chip을 매칭하고 이 결과로 수립된 정밀센서모델의 정확도를 분석하였다. 분석결과 5 m의 원본 해상도에서 정합하는 것보다 위성영상의 해상도를 높여서 정합하는 것이 개선된 정확도를 보여주었다. 특히, 원본 영상을 1.25~1.67 m 해상도로 분할하여 지상기준점 Chip과 정합 할 경우 평균 약 2.74 m 내외의 위치정확도를 얻을 수 있었다. 본 연구결과가 향후 농림위성영상의 자동기준점 추출 및 정밀정사영상 생산에 활용될 수 있을 것으로 기대한다.

CaO-Al2O3-SiO2 계 벌크 유리와 스프레이 코팅막의 CF4/O2/Ar 플라즈마 식각 시 내식성 비교 (Comparison of plasma resistance between spray coating films and bulk of CaO-Al2O3-SiO2 glasses under CF4/O2/Ar plasma etching)

  • 나혜인;박제원;박재혁;김대근;최성철;김형준
    • 한국결정성장학회지
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    • 제30권2호
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    • pp.66-72
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    • 2020
  • 본 연구에서는 CaO-Al2O3-SiO2(CAS) 계 유리 벌크와 유리 분체를 알루미나 소결체 표면에 스프레이 코팅막 적용 시 내플라즈마 특성에 대하여 비교하였다. CAS 유리 벌크와 유리 코팅막을 CF4/O2/Ar 플라즈마 가스에 노출시켰을 때의 식각율과 표면의 미세구조 분석을 통해 내플라즈마 특성을 확인하였다. CAS 유리 소성막은 유리 벌크와 비교하여 에칭속도가 최대 25배 빠른 것을 확인하였다. 유리 소성막의 표면 조도 값과 식각율 간의 통계학적으로 높은 상관성을 도출하였고, 이에 따라 소성막의 높은 표면조도가 빠른 식각을 유발하는 것으로 판단하였다. 그리고 유리 소성막은 Ca 성분의 함량이 적고, Si 함량이 많은 크리스토발라이트(cristobalite) 결정의 형성으로 인하여 Ca과 Ca 불화물에 의한 내플라즈마 효과가 감소한 것으로 판단된다. 따라서 CAS 유리 소성막은 유리 벌크에 비해 낮은 내플라즈마 특성을 갖는 것으로 판단된다.

알코올중독자의 회복척도 CAS(Client Assessment Summary) 한국어판의 타당도 검증 (Validity Verification of a Korean Version of Recovery Scale(Client Assessment Summary) for Alcoholics)

  • 이영선;김수연
    • 한국산학기술학회논문지
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    • 제17권11호
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    • pp.386-394
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    • 2016
  • 본 연구는 치료공동체에 거주하는 알코올 중독자의 회복을 측정하는 도구 CAS(Client Assesment Summary)의 한국어판의 타당도를 검증하여 일반 알코올 중독자의 회복 척도로 사용하기에 수용가능한지에 대한 적합성을 검증하는 것을 목표로 한다. 연구 대상자로 단주 중인 알코올 중독자 205명의 자료를 분석하였으며, 분석은 CAS 척도의 내용타당도, 신뢰도, 요인분석을 통한 구성타당도, 타 회복척도인 ARS, 단주기간, 단주 자기 효능감, 병식, 변화 동기 변수와의 관계 분석을 통해 기준타당도를 검증하는 분석을 시행하였다. 내용타당성 검증 후의 구성타당도 검증을 위한 요인분석 결과, CAS척도는 전체 12문항, 4개 요인으로 구성되었으며 전체 설명력은 76.26%, 공통성 0.6 이상, KMO 값 0.92로 구성타당도를 확인할 수 있었다. 내적일치도 계수는 .92로 신뢰도를 확인하였으며, ARS, 단주기간, 단주 자기효능감, 병식, 변화 동기 변인과의 상관관계로 기준타당도를 확인할 수 있었다. 이러한 검증 과정을 통하여 CAS척도가 치료공동체 뿐 아니라 일반 알코올 중독자에게 사용하기에도 타당한 척도임을 확인하였으며, 이상의 척도가 알코올 중독자의 회복을 평가하는데 학술적, 임상적으로 활용되어 궁극적으로 알코올 중독자의 회복에 기여하기를 기대한다.

A Study on the Impact of Continuous Antagonist Strengthening and Evjenth-Hamberg Stretching on the Cervical Mobility in Forward Head Posture Subjects

  • Park, Joo Hyun
    • 국제물리치료학회지
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    • 제4권2호
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    • pp.633-639
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    • 2013
  • This study aims to reveal the impact of continuous antagonist strengthening(CAS) and Evjenth-Hamberg stretching(EHS) on the cervical mobility in the university students with abnormal transformation of forward head posture(FHP). Our experiment was conducted 3 times a week for 6 weeks in a total of 20 individuals : continuous antagonist strengthening(CAS) group(n=10) & Evjenth-Hamberg stretching(EHS) group(n=10). In a pre and post comparison, both CAS group and EHS group appeared significantly in mSBI and SBA(p<.05) and the two-group comparison showed a significant difference(p<.05) : CAS group showed better effects. Thus, it is considered that the combined use with continuous antagonist strengthening(CAS) had better effects for cervical mobility than Evjenth-Hamberg stretching(EHS) alone.

Evaluation of the Genetic Toxicity of Synthetic Chemicals [XII] -in vitro Chromosomal Aberration Assay with 11 Chemicals in Chinese Hamster Lung Fibroblast-

  • Ryu, Jae-Chun;Kim, Youn-Jung
    • 한국환경성돌연변이발암원학회지
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    • 제24권2호
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    • pp.99-107
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    • 2004
  • The validation of many synthetic chemicals that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. In this respect, the regulation and evaluation of the chemical hazard playa very important role to environment and human health. The clastogenicity of 11 synthetic chemicals was evaluated in Chinese hamster lung (CHL) fibroblast in vitro. Benzoyl chloride (CAS No. 98-88-4) induced chromosomal aberrations with statistical significance at the concentration of 31-123 $\mug/ml$ and 43 $\mug/ml$ in the absence and presence of S-9 metabolic activation system, respectively. 2-Propyn-l-o1 (CAS No. 107-19-7) and 2-Phenoxy ethanol (CAS No. 122-99-6) revealed clastogenicity only at the highest concentration in the presence of S-9 mixture. However, 1-naphthol (CAS No. 90-15-3) which is one of the most cytotoxic chemical among 11 chemicals tested revealed no clastogenicity both in the presence and absence of S-9 metabolic activation system. From the results of chromosomal aberration assay with 11 synthetic chemicals in CHL fibroblast in vitro, Benzoyl chloride (CAS No. 98-88-4), 2-Propyn-l-01 (CAS No. 107-19-7) and 2-Phenoxy ethanol (CAS No. 122-99-6) revealed positive clastogenic results in this study.

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기계화학적 방법에 의한 CuSbS2와 CuSbSe2 나노입자의 합성 (Synthesis of CuSbS2 and CuSbSe2 Nanocrystals by a Mechanochemical Method)

  • 박보인;이승용;이도권
    • Current Photovoltaic Research
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    • 제5권4호
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    • pp.140-144
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    • 2017
  • $CuSbS_2$ (CAS) and $CuSbSe_2$ (CASe) nanocrystals (NCs), which consist of earth-abundant elements, were synthesized by a mechanochemical method. Elemental precursors such as copper, antimony, sulfur, and selenium were used without adding any organic solvents or additives. The NCs were synthesized by milling for a few hours. The sudden phase changes occurred by self-ignition and propagation, as previously observed in other mechanochemical synthetic processes. The XRD, Raman, and TEM analysis were carried out to determine the crystallinity and secondary phase of the as-synthesized CAS and CASe NCs, confirming the phase-pure synthesis of CAS and CASe. Optical properties were investigated by UV-Vis spectroscopy and it was observed that the band gap energies were about 1.1 and 1.5 eV, respectively for CAS and CASe, suggesting the potential for the use as solar cell materials. The NC colloids dispersed in anhydrous ethanol were prepared and coated on Mo substrates by a facile doctor-blade method. The investigation on the solar cell properties of the as-synthesized materials is underway.

An Ultra-narrow Bandwidth Filter for Daytime Wind Measurement of Direct Detection Rayleigh Lidar

  • Han, Fei;Liu, Hengjia;Sun, Dongsong;Han, Yuli;Zhou, Anran;Zhang, Nannan;Chu, Jiaqi;Zheng, Jun;Jiang, Shan;Wang, Yuanzu
    • Current Optics and Photonics
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    • 제4권1호
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    • pp.69-80
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    • 2020
  • A Rayleigh Lidar used for wind detection works by transmitting laser pulses to the atmosphere and receiving backscattering signals from molecules. Because of the weak backscattering signals, a lidar usually uses a high sensitivity photomultiplier as detector and photon counting technology for signal collection. The capturing of returned extremely weak backscattering signals requires the lidar to work on dark background with a long time accumulation to get high signal-to-noise ratio (SNR). Because of the strong solar background during the day, the SNR of lidar during daytime is much lower than that during nighttime, the altitude and accuracy of detection are also restricted greatly. Therefore this article describes an ultra-narrow bandwidth filter (UNBF) that has been developed on 354.7 nm wavelength of laser. The UNBF is used for suppressing the strong solar background that degrades the performance of Rayleigh wind lidar during daytime. The optical structure of UNBF consists of an interference filter (IF), a low resolution Fabry-Perot interferometer (FPI) and a high resolution FPI. The parameters of each optical component of the UNBF are presented in this article. The transmission curve of the aligned UNBF is measured with a tunable laser. Contrasting the result of with-UNBF and with-IF shows that the solar background received by a Licel transient recorder decreases by 50~100 times and that the SNR with-UNBF was improved by 3 times in the altitude range (35 km to 40 km) compared to with-IF at 10:26 to 10:38 on August 29, 2018. By the SNR comparison at four different times of one day, the ratio-values are larger than 1 over the altitude range (25~50 km) in general, the results illustrate that the SNR with-UNBF is better than that with-IF for Rayleigh Lidar during daytime and they demonstrate the effective improvements of solar background restriction of UNBF.