• 제목/요약/키워드: similar conversion

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Performance Prediction of Centrifugal Compressor Based on Performance Test, Similarity Conversion and CFD Simulation

  • Zhu, Changyun;Qin, Guoliang
    • International Journal of Fluid Machinery and Systems
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    • 제5권1호
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    • pp.38-48
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    • 2012
  • One centrifugal compressor is applied for refrigeration and its working substance is R134a. The operating points obtained by using similar conversion at different rotation speeds are compared with the numerical results. They keep consistent with each other while the rotation speeds are lower, but the error between them will become large with the increasing of the rotation speed. Then the operating points are obtained when the working substance is air by using two similar conversion methods separately. Based on the comparison, it can be obtained that the result of keeping the specific volume ratio of inlet and outlet is more accurate than the result of maintaining Ma number. Then the test result is compared with the similarity result and the numerical result when the working substance is air. It is obtained that the similarity result is more consistent with the test result better than the numerical result and the trend of efficiency and pressure ratio change with the flow rate is consistent with the test result. In the process of similar conversion, the efficiency ${\eta}$ is no useful for similitude design and it has less influence on the conversion result.

Growth, Feed Conversion Efficiency and Carcass Characteristics of Malpura and Malpura × Awassi Crossbred Lambs in a Hot Semi Arid Environment

  • Karim, S.A.;Santra, A.;Verma, D.L.
    • Asian-Australasian Journal of Animal Sciences
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    • 제15권3호
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    • pp.377-381
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    • 2002
  • The growth rate, feed conversion efficiency and carcass characteristics of nine native Malpura (M) and eight Awassi ${\times}$ Malpura half bred (AM) male lambs were compared under intensive feeding on 60:40 concentrate and roughage based composite feed. Weaning body weight was similar in the two genetic groups while finishing body weight, total body weight gain and average daily gain during the experiment were higher (p<0.01) in AM than M lambs. The feed conversion efficiency was lower in M than AM lambs with 15.7 and 19.8 per cent feed conversion efficiency, respectively, in the two genetic groups. The dressing yield in terms of preslaughter weight or empty live weight was however similar in the two genetic groups. The loin eye area was also greater (p<0.01) in AM than M lambs. The cutability was similar for the two groups amounting to 33.2, 13.3, 13.2, 23.3 and 16.6% of half carcass, respectively, for leg, loin, rack, neck and shoulder and breast and foreshank. On an average the separable lean, fat and KOH bone content of the half carcass were 48.3, 16.8 and 23.3% for native M and 54.1, 15.0 and 19.0% for AM lambs, respectively. It is concluded that growth rate and feed conversion efficiency were better in Awassi ${\times}$ Malpura half bred than native Malpura lambs while dressing yield and cutability of standard cuts were similar in the two genetic groups.

Biomass Conversion Efficiencies of Fish Pond Fertilization and Feed Supplementation

  • Mahboob, Shahid;Sheri, A.N.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권2호
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    • pp.192-195
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    • 1998
  • Biomass conversion efficiencies (B.C.E) of six fish species viz, Catla catla, Labeo, rohita, Cirrhina mrigala, Hypophthalmicthys molitrix, Ctenopharyngodon idella and Cyprinus carpio cultured under artificial feed (T1), broiler manure (T2), buffalo manure (T3), N:P:K (25:25:0) (T4) and control pond (T5) have been determined for the period of one year. The overall biomass conversion efficiencies under the influence of T2, T3, and T4 were statistically similar. However, the best (0.40) efficiency was determined under feed supplement-ation (T1).

전환장애의 물리치료 - 증례보고 - (Physical Therapy of Conversion Disorder - Case Report -)

  • 오덕원;정낙수
    • 한국전문물리치료학회지
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    • 제5권1호
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    • pp.51-62
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    • 1998
  • Conversion disorder is defined as a specific and enduring sensorimotor dysfunction that contradicts known neurological or musculoskeletal pathology or physical findings. The patient with conversion symptoms unconsciously adopts these symptoms to convert their psychological stress to a physical phenomenon. Conversion disorder often involves the mimicry of organic symptoms similar to those experienced by a relative or an acquaintance. Because conversion symptoms are produced by psychological stress, specific treatment strategy and reinforcement program are needed for treatment. Treatment comprises avoiding unnecessary medical tests and removing symptoms by using graded exercises given by physical therapists. Clinical therapists must maintain a continuous and detailed follow-up to completely recover from conversion symptoms. The goal of treatment is to emphasize health rather than disease, to resolve physical symptoms, and to prevent recurrence. This study looks into the case reports of 4 patients diagnosed with conversion disorder.

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개방단말 동축선 프로브의 개선된 환산모델에 대한 FDTD 검증 (FDTD Verification of an Improved Conversion Model for an Open-Ended Coaxial Probe)

  • 조유선;현승엽;김세윤
    • 한국전자파학회논문지
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    • 제15권5호
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    • pp.493-498
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    • 2004
  • 개방단말 동축선 프로브를 사용하여 0.2∼2.0 ㎓에서 측정된 메탄올의 복소 유전율을 문헌에 주어진 값과 비교해 본 결과 많은 차이를 보였다. 본 논문에서는 실험에 사용된 메탄올 용액의 복소 유전율이 측정치와 주어진 값 중에 어디에 더 가까운지를 조사하였다. 무시할만큼 작은 측정오차에 대한 영향은 배제하고, 환산 모델 오차만의 영향을 확인하기 위해서 FDTD 기법을 도입하였다. FDTD 수치 계산된 반사계수를 우리의 환산모델에 의해 복소 유전율로 환산한 값이 주어진 값이 아닌 측정값에 더욱 근접함을 보임으로서 우리가 사용한 측정-환산 과정의 정확도와 안정도를 확인하였다.

전환장애 환자에 개결서경탕(開結舒經湯)을 투여한 치험례 (A Case of Conversion Disorder Treated with Gaegyeolseogyeong-tang)

  • 윤지원;김홍준;김우성;심국진;심하나;이상관;강세영
    • 대한한방내과학회지
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    • 제25권3호
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    • pp.590-595
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    • 2004
  • Conversion Disorder is a disorder whose predominant feature is a loss or alteration in physical functioning that suggests a physical disorder but that is actually a direct expression of a psychological conflict or need. The Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) guidelines for Conversion Disorder include these definitions: A psychosocial stressor produces a psychological conflict that is believed to help initiate or exacerbate the illness The symptoms are not under conscious control, etc. While functional disabilities are common with conversion disorders, physical and laboratory abnormalities are absent or minor in comparison with the patient's subjective complaints. Symptoms of Conversion Disorder are similar to those of stroke. But the mechanism of Conversion Disorder is similar as that of Stagnation Syndrome of Ki (氣鬱證) in Oriental medicine. Gaegyeolseogyeong-tang has been used to treat women who suffer from Conversion Disorder induced by the Stagnation Syndrome of Ki (氣鬱證). After application of the Gaegyeolseogyeong-tang for 7 days, symptoms and signs improved dramatically.

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Effect of Heat-treated Ceruloplasmin on the Hepatic xanthine Oxidase Activity and Type Conversion

  • Huh, Keun;Shin, Uk-Seob;Lee, Sang-Il
    • Archives of Pharmacal Research
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    • 제18권1호
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    • pp.56-59
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    • 1995
  • The effect of ceruloplasmin or copper ion on hepatic xanthine oxidase activity and type conversion was investigated using rat liver in vitro. It was observed that ceruloplasmin increased xanthine oxidase type conversion depending on duration of its storage. Xanthine oxidase (type O) activity and type conversion in incubation mixture was increased by the addition of heated celuroplasmin in a temperature dependent manner. The type conversioin of xanthine oxidase induced by heated ceruloplasmin was retumed to normal by the tratment with DTT or penicillamine. The effect of copper ion on type conversion of xanthine oxidase was similar to that of heated ceruloplasmin.

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렌즈군의 일반화된 등가렌즈 변환 (Generalized lens group conversion to their equivalent lenses)

  • 이종웅;박성찬
    • 한국광학회지
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    • 제9권4호
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    • pp.251-257
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    • 1998
  • 등가렌즈 변환을 렌즈군의 변환으로 확장하였으며, 보다 일반화된 변환법을 개발하였다. 새로운 변환법은 두꺼운 렌즈계에서 바로 두꺼운 렌즈계로의 변환이 가능하다. 등가렌즈 변환을 통하여 얇은 렌즈계는 서로 다른 두께를 가지면서도 근축 광학적 특성이 같고 수차특성이 유사한 여러 개의 두꺼운 렌즈계로 변환 될 수 있다. 예로서 telephoto 렌즈계의 설계변경에 등가렌즈 변환을 적용하여 보았으며, 앞부분 렌즈군의 축상두께를 원설계의 75%로 축소하였다. 등가렌즈 변환을 통하여 얻어진 수정설계의 초점거리는 원설계와 동일하였으며, 축상두께만을 변경시킨 경우에 비하여 수차특성의 변화가 적음을 확인할 수 있었다.

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Bench-scale Experiment on Catalytic Decomposition of 1,2 Dichlorobenzene by Vanadia-Titania Catalyst

  • Jeong, Ju-Young;Chin, Sung-Min;Jurng, Jong-Soo
    • 한국환경과학회지
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    • 제18권7호
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    • pp.709-714
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    • 2009
  • Catalytic activities of $V_2O_5/TiO_2$ catalyst were investigated under reaction conditions such as reaction temperature, catalyst size, inlet concentration and space velocity. A 1,2-dichlorobenzene(1,2-DCB) concentrations were measured in front and after of the heated $V_2O_5/TiO_2$ catalyst bed, and conversion efficiency of 1,2-DCB was determined from it's concentration difference. The conversion of 1,2-DCB using a pellet type catalyst in the bench-scale reactor was lower than that with the powder type used in the micro flow-scale reactor. However, when the pellet size was halved, the conversion was similar to that with the powder type catalyst. The highest conversion was shown with an inlet concentration of 100 ppmv, but when the concentration was higher or lower than 100 ppmv, the conversion was found to decrease. Complete conversion was obtained when the GHSV was maintained at below 10,000 $h^{-1}$, even at the relatively low temperature of $250^{\circ}C$. Water vapor inhibited the conversion of 1,2-DCB, which was suspected to be due to the competitive adsorption between the reactant and water for active sites.

On-line Conversion Estimation for Solvent-free Enzymatic Esterification System with Water Activity Control

  • Lee, Sun-Bok;Keehoon Won
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제7권2호
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    • pp.76-84
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    • 2002
  • On-line conversion estimation of enzymatic esterification reactions in solvent-free media was investigated. In principle, conversion to ester can be determined from the amount of water produced by the reaction, because water is formed as a by-product in a stoichiometric manner. In this study, we estimated the water production rate only from some measurements of relative humidity and water balances without using any analytical methods. In order to test the performance of the on-line conversion estimation, the lipase-catalyzed esterification of n-capric acid and n-decal alcohol in solvent-free media was performed whilst controlling water activity at various values. The reaction conversions estimated on-line were similar to those determined by offline gas chromatographic analysis. However, when the water activity was controlled at higher values, discrepancies between the estimated conversion values and the measured values became significant. The deviation was found to be due to the inaccurate measurement of the water content in the reaction medium during the initial stages of the reaction. Using a digital filter, we were able to improve the accuracy of the on-line conversion estimation method considerably. Despite the simplicity of this method, the on-line estimated conversions were in good agreement with the off-line measured values.