• 제목/요약/키워드: $L_{eq}$

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공동의 폭 변화에 따른 3차원 초음속 공동 유동연구 (NUMERICAL ANALYSIS OF THREE DIMENSIONAL SUPERSONIC CAVITY FLOW FOR THE VARIATION OF CAVITY SPANWISE RATIO)

  • 우철훈;김재수
    • 한국전산유체공학회지
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    • 제11권4호
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    • pp.62-66
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    • 2006
  • High-speed flight vehicle have various cavities. The supersonic cavity flow is complicated due to vortices, flow separation, reattachment, shock waves and expansion waves. The general cavity flow phenomena includes the formation and dissipation of vortices, which induce oscillation and noise. The oscillation and noise greatly affect flow control, chemical reaction, and heat transfer processes. The supersonic cavity flow with high Reynolds number is characterized by the pressure oscillation due to turbulent shear layer, cavity geometry, and resonance phenomenon based on external flow conditions. The resonance phenomena can damage the structures around the cavity and negatively affect aerodynamic performance and stability. In the present study, we performed numerical analysis of cavities by applying the unsteady, compressible three dimensional Reynolds-Averaged Navier-Stokes(RANS) equations with the ${\kappa}-{\omega}$ turbulence model. The cavity model used for numerical calculation had a depth(D) of 15mm cavity aspect ratio (L/D) of 3, width to spanwise ratio(W/D) of 1.0 to 5.0. Based on the PSD(Power Spectral Density) and CSD(Cross Spectral Density) analysis of the pressure variation, the dominant frequency was analyzed and compared with the results of Rossiter's Eq.

Preparation and In Vivo Evaluation of Huperzine A-Loaded PLGA Microspheres

  • FU XU-DONG;GAO YONG-LIANG;PING QI-LENG;Ren Tang
    • Archives of Pharmacal Research
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    • 제28권9호
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    • pp.1092-1096
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    • 2005
  • Huperzine A-loaded microspheres composed of poly(D,L-lactide-co-glycolide) were prepared by an O/w emulsion solvent evaporation method. The characterization of the microspheres such as drug loading, size, shape and release profile was described. The in vitro release in the initial 7 days was nearly linear with $10\%$ released per day. Thereafter drug release rate became slow gradually and about $90\%$ drug released at day 21. The in vitro release rate determined by dialysis bag method had a good correlation with the in vivo release rate. Huperzine A aqueous solution was intramuscularly injected (i.m.) at 0.4mg/kg and microspheres were intra­muscularly injected at 8.4 mg eq huperzine A/kg in rats. The maxium plasma concentration $(C_{max})$ after i.m. microspheres was only $32\%$ of that after i.m. solution. Drug in plasma could be detectd until day 14 and about $5\%$ of administered dose was residued at the injection site at day 14. The relative bioavailability of huperzine A microspheres over a period of 14 days was $94.7\%$. Inhibition of acyecholinesterase activity (AchE) in rat's cortex, hippocampus and striatum could sustain for about 14 days. In conclusion, huperzine A-loaded microspheres possessed a prolonged and complete drug release with significant inhibition of AchE for 2 weeks in rats.

도시 환경음의 쾌적성 평가요인에 관한 연구 (Acoustic Amenity Factor of Urban Environmental Sound for the Ecological Soundscape)

  • 국찬;송민정;신훈;장길수
    • 한국소음진동공학회논문집
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    • 제16권4호
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    • pp.428-436
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    • 2006
  • The assessment of an urban site depends on the way whether it responds to multiple needs such as functionality, aesthetic and complex comfort of acoustic, thermal, lighting and air quality etc. This study aims to investigate the assessment of various urban soundscapes in the sense of acoustic amenity by the questionnaires. As a result, acoustic amenity assessment was influenced by the non-acoustic factors such as environment assessment of visual, thermal, air quality etc. In the sense of sound quality, urban environmental sound was interpreted as 3 factors of strength, evolution of time, spacial localization. So these factors would be considered in the new assessment method for acoustic amenity. And it was shown that the subjects tend to perceive the noise level less than $3{\sim}5dB\;L_{eqA}$ according to the urban landscapes under the similar noise exposure level.

강수중 화학성분 분석자료의 해석 (Interpretation of Chemistry Analytical Data in Precipitation)

  • 강공언;전종남;김희강
    • 한국환경보건학회지
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    • 제22권4호
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    • pp.62-68
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    • 1996
  • Precipitation samples were collected by the wet-only event sampling method at Seoul from September 1991 to April 1995. Concentrations of samples for the ion components($NO_3^-, NO_2^-, SO_4^{2-}, Cl^-, F^-, Na^+, K^+, Ca^{2+}, Mg^{2+}$ and $NH_4^+$) were measured in addition to pH and electric conductivity. During the sampling period, 182 samples were collected, but only 163 samples were identified as valid. The pH, calculated from the volume-weighted $H^+$ concentration, was found to be 4.7, indicating a relatively intensive acidity compared with data from other regions of the world, where acid deposition was known to be a problem. Above all, the concentration of non-seasalt sulfate was $84 \mu eq/L$, which was the highest compared to that measured in other regions of the world. The major acidifying ions in the precipitation at Seoul were identified as sulfate and nitrate except for chloride, because the Cl/Na ratio in the precipitation was close to the ratio in seawater. If all of the non-seasalt sulfate and nitrate existed in the form of sulfuric and nitric acids, respectively, the average pH in the precipitation was calculated as 3.7, lower than the measured value. Consequently, the difference between the calculated and measured pH suggest that the acidity of precipitation was neutralized by alkaline species, not due to the low contribution of an anthropogenic air pollutants to the precipitation. The equivalent concentration ratio of sulfate to nitrate was 3.5, which indicated that the contributions of sulfuric and nitric acids to the precipitation acidity were 78% and 22%, respectively.

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한국인(韓國人)의 식염(食鹽) 및 질소대사(窒素代謝)에 관(關)하여 (Studies on Sodium Chloride and Nitrogen Metabolism of the Korean)

  • 정순동;양일석
    • The Korean Journal of Physiology
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    • 제1권2호
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    • pp.193-197
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    • 1967
  • In order to study the daily metabolism of sodium chloride and of nitrogen, 24 hour urine samples were collected from 298 normal Korean males whose ages varied Iron 26 to 80 years old. The volume and the concentration of chloride and the total nitrogen were determine, along with the resting pulse and the blood pressure. The daily urine volume was maintained at approximately $1,000\;ml/m^2$ in all age groups while the chloride concentration was at approximately 230 mEq/l. Hence the daily urinary output of sodium chloride was estimated to be approximately 21 gm. On the other hand, the daily urinary output of total nitrogen amounted to approximately 10 gm. Theses findings are similar to those obtained earlier by Yi et al. (1966) in Korean subjects younger than 25 fears old, indicating that average Koreans live on low protein and high salt diets throughout their life. Despite a known correlation between the incidence of hypertension and the high salt intake, none of the these subjects employed in the present investigation showed any sign of hypertension.

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도로 교통소음의 환경평가 단위인 24시간 등가소음레벨에 대한 적정성 검토에 관한 연구 (A Study on Examination of Propriety about L eq24 in Road Traffic Noise Environment Standard Evaluation)

  • 김병삼;지창헌;최홍철
    • 한국소음진동공학회논문집
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    • 제17권3호
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    • pp.274-281
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    • 2007
  • Road traffic noise is not produced by any one factor rather it occurs as a composition of various factors. Its occurrence is made by running engine noise, tire frictional, and exhaust noise etc. The quality of the noise depends on the size of the vehicles, rotation and engine speed, vehicle load, package state of the road and incline etc. The occurrence of any noise level of heavy trucks appears louder than smaller vehicles and the noise levels produced differs according to speed and load etc between similar size vehicles. Other factors such as traffic density, average speed, mixing rate of heavy vehicles, and the distance between vehicles also generate road traffic noise. In this paper we examine 2, 4, and 6-lane roads in Jeonju. Consequently, this study examines the means used to measure road traffic noise. It was found that when there is a large traffic density and the average velocity is below 70 km/h, the noise level could receive a relative proper value by the current measuring means. But in the case of night-time, it was found that the current measuring method is inapposite.

만성 골관절염 노인을 위한 지역사회 간호사 주도 복합운동 프로그램의 효과 (Effect of Nurse-led Community Comprehensive Exercise Program for Elderly with Chronic Osteoarthritis)

  • 백희정;임원지
    • 가정간호학회지
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    • 제26권1호
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    • pp.102-110
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    • 2019
  • Purpose: This study aimed to investigate the effects of a nurse-led community comprehensive exercise program on the body composition, physical function, and health-related quality of life in elderly patients with osteoporosis. Method: The study was conducted with one group pretest-posttest design. A total of 57 elderly patients participated in 8 weeks of intervention. Data was analyzed with the SPSS ver. 23.0 using descriptive statistics and paired t-test. Results: At the end of the intervention, body mass index was significantly increased (t=2.93, p=.005), but right leg balance (t=2.40, p=.02) was significantly improved. In addition, the total Korean-Western Ontario and McMaster Universities Osteoarthritis Index (K-WOMAC) (t=3.48, p=.001), knee pain (t=2.61, p=.012), stiffness (t=2.53, p=.014), and physical function (t=3.51, p=.001) were significantly decreased. EuroQoL Visual Analogue Scale (EQ-VAS) scores (t=4.25, p<.001) were significantly improved. Conclusion: The nurse-led eight-week community comprehensive exercise program did not show desirable change in the body composition but was effective on the physical function and health-related quality of life for older people with osteoartritis.

족하수 환자의 복합 한의진료 경과 및 삶의 질 변화: 증례보고 (Combination of MSAT and Korean Medicine for Managing Foot Drop Due to Lumbar Disc Herniation: Case Report)

  • 박지원;정우진;허효승;홍혜원;구지은
    • Korean Journal of Acupuncture
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    • 제38권3호
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    • pp.189-195
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    • 2021
  • Foot drop due to lumbar disc herniation is perceived to be an indication for surgery. A 44-year-old male presented with motor deficit in left ankle dorsiflexion along with radiating pain and paraesthesia. Motion Style Acupuncture Therapy (MSAT) was administered on the left side every other day. Acupuncture and Chuna were performed daily. Herbal medicine was taken 3 times a day. His symptoms rapidly improved throughout treatment, verified by decreased Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), increased 5-level EuroQol-5 Dimension (EQ-5D-5L) scores, and improved motor grades. We suggest that a combination of MSAT with traditional Korean medicine could be a favorable option for foot drop in LDH patients in terms of rapid pain reduction and the improvement of quality of life.

후방 발목 충돌 증후군 환자의 복합 한의진료 경과: 증례보고 (Complex Korean Medicine Treatment for Posterior Ankle Impingement Syndrome: Case Report)

  • 박지원;경다현;구지은;배준효;김수진;배지은
    • Korean Journal of Acupuncture
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    • 제39권3호
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    • pp.100-106
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    • 2022
  • Posterior ankle impingement syndrome is one of the impingement syndromes characterized by posterior ankle pain that occurs during forced plantar flexion. This report presents a case of a 48-year-old PAIS patient with os trigonum syndrome accompanied by tenosynovitis of flexor hallucis longus. She was treated with complex Korean medicine to a good effect. The Numeric Rating Scale and the EuroQol 5-Dimension 5-Level were used to measure the impact of Korean medicine on the patient's pain and quality of life. Decreased NRS and increased EQ-5D-5L scores reflected improvement in her symptoms within 25 days. This study suggests complex Korean medicine treatment for PAIS may be beneficial for alleviating pain and improving quality of life.

Mucor Miehei 응유효소(凝乳酵素)로 제조(製造)한 Camembert Cheese의 숙성(熟成)에 관(關)한 연구(硏究) (The Ripening of Camembert Cheese Made with Mucor Miehei Rennet)

  • 박무일;김종우
    • 농업과학연구
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    • 제16권2호
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    • pp.179-200
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    • 1989
  • Camembert cheese 제조(製造)에 있어 calf rennet의 대체이용(代替利用)을 위(爲)한 기초연구(基礎硏究)로서 Mucor miehei 응유효소(凝乳酵素)를 calf rennet와 일정(一定) 비율(比率)로 혼합(混合) 첨가(添加)하고 cheese의 수율(收率), 숙성기간(熟成期間)에 따른 일반성분(一般成分)의 변화(變化), 실소화합물(室素化合物), 아미노산(酸), 유리지방산(遊離脂肪酸), 무기물(無機物)의 변화(變化) 및 분자량별(分子量別) 분획(分劃), 전기영동(電氣泳動), 조직특성(組織特性) 및 관능검사(官能檢査) 연구(硏究)에서 얻은 결과(結果)는 다음과 같다. 1. Camembert eheese의 수율(收率)은 15%로서 calf rennet와 Mucor rennet간(間)에는 큰 차이(差異)이 없었다. 2. 단백질(蛋白質), 지방(脂肪) 및 회분함량(灰分含量은 Mucor rennet편이 적었으며 숙성(熟成)이 진행(進行)됨에 따라 유당(乳糖)은 14일 이후(以後) 급격(急激)한 감소현상(減少現像)을 나타내고 첨가비율(添加比率)에 따른 차이(差異)는 인정(認定)되지 않았다. 3. 제조직후(製造直後) 수용성(水溶性) 질소량(窒素量)은 14.7~17.3%였으나 숙성(熟成)이 진행(進行)됨에 따라 39.7~41.0%로 증가(增加)하였으며 숙성(熟成) 21일(日)에는 calf rennet에 비(比)하여 Mucor rennet편이 높았고 비(非)케이신태(態) 질소(窒素) 및 암모니아태(態) 질소(窒素)는 21일(日) 이후(以後) Mocor rennet편이 높은 증가율(增加率)을 나타내었다. 4. 숙성(熟成)이 진행(進行)됨에 따라 calf rennet에 비(比)하여 Mucor rennet편이 cysteine, phenylalanine 및 proline 등(等)이 증가(增加)하였으나 aspartic acid, threonine 및 glutamic acid등(等)은 감소(減少)하였다. 5. 유리지방산량(遊離脂肪酸量)은 calf rennet에 비(比)하여 Mucor rennet편이 높았고 숙성(熟成)이 진행(進行)됨에 따라 8.36 mEq으로부터 26.36 mEq에 이르는 함량(含量) 증가(增加)를 나타냈으나 처리간(處理間)에는 유의성(有意性)있는 큰 차이(差異)를 나타내지 않았다. 6. 시료중(試料中)의 Ca량(量)은 0.238~0.272%, Mg량(量)은 0.019~0.002%, Na은 0.910~1.047%, K은 0.175~0.200%였으며 casein에서 중요(重要)한 비침전성(非沈澱性) Ca량(量)은 숙성기간(熟成期間)과 효소첨가중(酵素添加重)에 관계(關係)없이 61%에서 77%까지 Mg에서는 59.1%에서 92.5%까지 비침전성(非沈澱性) 수용성(水溶性)으로 남아 있었다. 7. 분자량(分子量) 50,000이상(以上)의 단백질(蛋白質)은 숙성9熟成)이 진행(進行)됨에 따라 초기(初期)의 95%에서 45%까지 감소(減少)되고 분자량(分子量) 10,000이하(以下)는 0.2에서 38%까지 증가(增加)되어 숙성(熟成)에 의(依)한 casein의 분해(分解)가 확실(確實)하였다. 8. 숙성(熟成) 2주(週)부터 Mucor rennet의 첨가비율(添加比率)에 따라 casein의 전기영동(電氣泳動)은 다르게 나타났으며 숙성(熟成) 4주(週)에는 calf rennet 처리구(處理區)에 비(比)하여 Mucor rennet 처리구(處理區)의 전(全) band는 다소 잔존(殘存)함을 볼 수 있었다. 9. in vitro소화율(消化率)은 처리(處理)에 따라 81.48~94.81%로 부터 94.47~98.61%로 증가(增加)하였으며 처리간(處理間)에는 유의(有意)한 차이(差異)를 나타내지 않았다. 10. Mucor rennet 처리구(處理區)는 calf rennet처리구(處理區)에 비(比)하여 Hardness가 낮았으며 숙성(熟成)이 진행(進行)됨에 따라 더욱 감소(減少)하였다. 11. 관능검사(官能檢査) 결과(結果) Camembert cheese의 표면상태(表面狀態), 촉감(觸感), 절단면(切斷面), 풍미(風味) 및 고미등(苦味等)은 calf rennet와 Mucor rennet 처리간(處理間)에 차이(差異)를 인정(認定)할 수 없었다.

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