• 제목/요약/키워드: optimum condition

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태양열을 이용한 흡수식 냉방시스템의 시뮬레이션과 운전조건의 검토 (Simulation of Solar/Absorption Cooling Hybrid System and Examination of Its Operating Condition)

  • 허재영;이상용
    • 대한설비공학회지:설비저널
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    • 제14권1호
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    • pp.1-11
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    • 1985
  • Solar/absorption cooling system was analyzed and its operating condition was examined. For the system, the optimum size of absorption refrigerator and collector area should be determined. As the temperature of water supplied to the generator increases, the collector efficiency decreases whereas the coefficient of performance of absorption refrigerator increases up to a certain point, and vice versa for decreasing of the temperature of water supplied to the generator . Thus if the reeling load is given, the appropriate operating condition can be determined between the two opposing trends by simulation program. As an example of the simulation, the case of Jejudo province was studied. Under the conditions (such as weather data and prices of components, etc.) given en the sample calculation, the result shows that the optimum temperature of water supplied to the generator turned out to be $80.3^{\circ}C$, and still shows a large economical disadvantage in present stage compared to the case of conventional vapor compression cooling/heating combined heat pump system.

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머시닝센터에서 볼 엔드밀가공으로 고능률, 고정밀도 제고를 위한 표면가공 조건 (Cutting Condition for Improving Cutting Efficiency and Accuracy by Ball Endmill on a Machining Center)

  • 윤종학
    • 한국생산제조학회지
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    • 제7권3호
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    • pp.99-103
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    • 1998
  • The curved surface machined by plate end mill causes a excess non-cutting volume, in these cases ball end mill is used for the curved surfaces. This study is aimed to obtain the optimum cutting conditions of various cutting speed, table speed, tool diameter, radius of curvature roughness on the conditions of various cutting speed, tool diameter, radius of curvature when machining the curved surface using the ball end mill. After designing curve rates, obtaining NC data by CAD/CAM system through CC-Cartesian method and transferred the data through DNC system, we machined the specimens by the CNC machining center, The surface roughness of specimens was measured by surface roughness tester and CNC 3D coordinate measuring machine. The cutting condition were the same as follow velocity; 15, 20, 25 30m/min, feed rate;40, 60, 80, 100m/min and radius of curvature; 30,40,50,60mm, tool diameters; ø8, ø12, ø16, ø 20mm. Analizing the working results, we can acquire the optimum cutting condition of curved specimen at the cutting velocity of 20~25m/min and the feed rate of 80mm/min. As the same cutting condition the best surface roughness was showed at ø16mm of the tool diameter. But the tool diameter was smaller than ø8mm. we could improve for the surface roughness by controlling the cusp.

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맛버섯(Pholiota nameko) 우량균주 선발 및 병 재배법 (Cultivation technique using plastic container and selection the superior strain of nameko mushroom (Pholiota nameko))

  • 정경주;최덕수;최형국;김정근;정기철
    • 한국버섯학회지
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    • 제5권2호
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    • pp.51-58
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    • 2007
  • 맛버섯의 우량균주를 선발하고 병재배에 적합한 환경조건과 재배기술을 찾고자 시험한 결과는 다음과 같다. 맛버섯 균사는 MCM배지와 Hamada배지에서 잘 자랐고, 배지의 적정산도는 pH6~7이었다. 균사생육에 가장 적합한 온도는 $25^{\circ}C$였으며, $15^{\circ}C$ 이하와 $30^{\circ}C$ 이상의 조건에서는 균사생육이 현저하게 늦어졌다. 맛버섯 균주 29계통 중 생산성이 좋은 계통은 JNM19007, JNM19026, JNM19027과 JNM19028이었다. 자실체 생산을 위하여 가장 적합한 배지조성비는 미송톱밥 80%와 밀기울 20%(V/V) 혼합배지로 1,100cc 병당 평균 188g의 자실체가 생산되었다. 최적 후배양기간은 50일 이었으며, 균긁기 후 7일 만에 발이 되었다. 발이유기동안 적정 온도는 $12^{\circ}C$이었고, 생육기에는 $16^{\circ}C$였다. 맛버섯 전 재배기간 동안 적합한 상대습도는 95%였다.

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대마직물(안동포)의 방추가공에 관한 연구 (Study of Crease Resistant Finish on Hemp Fabrics(Andongpo))

  • 최희;김용;홍성학
    • 한국의류산업학회지
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    • 제6권2호
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    • pp.229-233
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    • 2004
  • Andongpo, 100% Korean hemp fabric was treated with the glyoxale resin type finishing agent and/or the soluble urethane type finishing agent to determine the optimum process condition of the crease resistant finish and the crease recovery of treated sample fabrics was evaluated for the study. The treatment conditions for the study were 6 conditions, such as, A-1~A-6, in which A-1 was the condition of treatment glyoxale resin type finishing agent only and A-2~A-6 were the condition of treatment both glyoxale resin type finishing agent and soluble urethane type finishing agent. Among the 6 conditions, the crease recovery of the sample treated with A-4 condition was $148^{\circ}$(angle of recovery method) and grade 3.2(appearance method) and so, these samples showed the excellent crease recovery. From the result, 15g/l of the catalyst conc., 50g/l of the glyoxale resin type finishing agent cone., and 40g/l of the softner were the optimum treatment condition for the crease resistant finish of the andongpo.

실험계획법에 의한 메틸염화실란 합성의 최적공정조건 (Optimum Process Condition by Experimental Design Method for the Synthesis of Methylchlorosilanes(MCS))

  • 조철군;한기도
    • 공업화학
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    • 제9권3호
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    • pp.394-398
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    • 1998
  • 실리콘의 모노머로 사용되고 있는 MCS의 합성 최적조건에 관한 연구를 수행하였다. 4원촉매계($CuCl/ZnCl_2/Sn/Cd$)와 원료규소로 부터 접촉물질을 제조한 후, 염화메틸과 반응시켜 MCS를 합성할 때 실험계획법에 따라 실험하고 해석하여 하나의 공정조건을 확립하였다. 접촉물질 50g, 교반속도 60rpm, 상압에서 최적반응온도와 MeCl 유량은 각각 $300-305^{\circ}C$$70-80cm^3/min$이었다. 또한 연속적으로 실험을 수행하여 최적공정조건을 확인하였으며, MeCl의 전환율 67%와 규소소모율 92%에서 평균반응속도는 170(g-MCS/hr.kg-Si), 평균선택도는 0.05이었으며, 연속식 실험결과로부터 총괄반응속도식의 파라미터와 최적압력을 구하였다.

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멸치와 김 생산량 변동에 미치는 수온의 영향 (Effect of Temperature on Anchovy Catch and Laver Production in the Eastern Part of the South Sea of Korea)

  • 이충일;김현주
    • 한국환경과학회지
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    • 제16권8호
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    • pp.897-906
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    • 2007
  • Effect of seawater temperature (temperature) on the production of anchovy, Engraulis japonica and laver, Porphyra tenera Kjellman, were investigated in the eastern part of South Sea of Korea (ESS). Bimonthly temperature data (Feb., Apr., Jun., Aug., Oct., Dec.) from 1980 to 2002 were collected from Korean Oceanographic Data Center (KODC) and monthly anchovy catch and laver production from 1980 to 2002 were used from published sources by the Ministry of Maritime Affairs & Fisheries, Korea. Effects of temperature on the two organisms were examined in four cases. In case of lower anchovy catch and higher laver production (1993), temperature during main spawning season of anchovy was about $0.2-0.6^{\circ}C$ lower than normal condition, and temperature during seed collecting season of laver in Namhaedo, Kojedo went down below $22.0^{\circ}C$. In case of higher anchovy catch and higher laver production (1995), optimum temperature for catch was formed in main fishing ground, temperature for seed collection was lower than $22.0^{\circ}C$, In case of lower anchovy catch and lower laver production (1996), temperature for spawning and catch was about $0.6-1.6^{\circ}C$ lower than normal condition, and temperature during seed collection in nursery was about $0.5-1.0^{\circ}C$ higher than optimum temperature for seed collection. In case of higher anchovy catch and lower laver production (1998), temperature during main fishing and spawning season was about $1.0-1.8^{\circ}C$ higher than normal condition, and temperature during laver seed collection in nursery was $1.5^{\circ}C$ higher than optimum temperature for seed collection.

박용추진축계의 최적배치에 관한 연구 (Optimum Alignment of Marine Propulsion Shafting)

  • 문덕홍
    • 수산해양기술연구
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    • 제18권1호
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    • pp.39-46
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    • 1982
  • 박용추진축계의 최적배치상태를 얻기 위해 선형계획법에 의한 최적배치 전산프로그램을 개발했으며, 여기에 필요한 자료들은 삼차모먼트정리를 매트릭스산법으로 전산처리해서 얻어냈고, 이 프로그램의 신속성을 확인하기 위해 모형축의 계산치와 스트레인 게이지에 의한 실측치를 비교하고, 실선축계에 적용한 결과 다음과 같이 요약할 수 있었다. 1. 최적배치의 필수자료인 직선지지상태의 반력 및 반력경향계수를 구하는 전산프로그램을 개발해서, 모형축에 적용한 결과, 실험치와 계산치가 거의 일치했고, 실선축에 대해 계산한 값도 타 프로그램으로 계산한 것과 거의 비슷했다. 2. 본 논문의 스트레인게이지에 의한 축계상태치의 계측방법은 실선축의 배치상태의 조정시에 매우 효과적으로 활용할 수 있을 것이다. 3. 최적배치의 전산프로그램을 실선축에 적용한 결과, 제한조건을 만족하려면, 지지베어링들을 상당량 수직방향으로 조절해야 함을 알 수 있었다. 따라서 최적배치의 관건은 배치계산에 필요한 정확한 자료와 제한조건을 구하는 것이라 할 수 있겠다.

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메밀순의 증숙 및 건조에 따른 침출차 특성 모니터링 (Monitoring on the Tea with Steaming and Drying Process of Germinated Buckwheat)

  • 이기동;윤성란;김정옥;허상선;서권일
    • 한국식품영양과학회지
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    • 제33권1호
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    • pp.212-217
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    • 2004
  • 메밀순을 이용한 침출차를 제조하고자, 증숙시간과 건조온도를 달리 처리하여 가용성 고형분 함량, 총 플라보노이드 함량 및 관능적 특성을 살펴보았다. 메밀순차 침출액의 가용성 고형분 함량은 증숙시간 6.93 min 및 건조온도 73.59$^{\circ}C$에서 최대값으로 나타났으며, 총 플라보노이드 함량은 증숙시간 5.22 min 및 건조온도 79.05$^{\circ}C$에서 높은 함량을 나타내는 것으로 나타났다. 메밀순 침출차의 전반적 기호도에 대한 높은 관능평점은 증숙시간 6.00 min 및 건조온도 77.33$^{\circ}C$인 것으로 나타났다. 가용성 고형분 및 총 플라보노이드 함량이 높고 전반적인 기호도도 우수한 조건은 증숙시간 5.4∼7.0 min 및 건조온도 75∼8$0^{\circ}C$로 예측되었으며 최적 조건에서의 예측된 관능평점은 최적 조건에서 실제 실험한 결과와 유사하였다.

주조/단조 공정에서 Al6061의 단조효과에 관한 연구 (Forging Effect of Al6061 in Casting/Forging Process)

  • 권오혁;배원병;조종래
    • 한국정밀공학회지
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    • 제22권11호
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    • pp.45-50
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    • 2005
  • In this study, the casting/forging process was applied in manufacturing a low control arm, in order to prove that application of casting/forging process to Al6061 is likely to get the effect of light weight compared with existing steel products and to reduce the cost of materials. Firstly, In order to set up the optimum casting condition of the forging material, Al6061, casting experiments were carried out by controlling pouring temperature of the aluminum for casting, mold temperature, and pouring time. $700^{\circ}C$ pouring temperature, $300^{\circ}C$ mold temperature and 10-second pouring time were taken into account as the optimum casting conditions. With respect to a hot forging test, it is practiced on the basis of a temperature of materials, strain rate, and reduction rate so as to observe each microstructure and examine strain-stress curve simultaneously; examine tensile test and hardness test; eventually set up the optimum hot forging condition. A hot forging test, tensile test, hardness experiment, and microstructure observation were carried out on condition of $70\%$ reduction rate, $500^{\circ}C$ temperature of materials, and 1 strain rate. As a result of those experiments, 330MPa tensile strength, $16.4\%$ elongation, and 122.8Hv hardness were recorded. In oder to get a sound preform which has no unfitting cavity and less flash, two preforms were proposed on the basis of volume rate of the final product; the optimum volume rate of preform for the low control arm was $115\%$. In conclusion, it is confirmed that using the forging material rather than casting materials in casting/forging process is likely to get more superior mechanical properties. Compared with Al6061, performed by means of general forging, moreover, cast/forged Al6061 can not only stimulate productivity by reducing production processes, but cut down the cost of materials by reusing forging scraps.

합판대용(合板代用) 박판상(薄板狀) 복합재(複合材) 제조(製造)에 관(關)한 연구(硏究) (I) - 복합재(複合材) 제조(製造)의 최적조건(最適條件)에 관(關)하여 - (Studies on Manufacture of Thin Composite Panel for Substitute Use of Plywood (I) - On the Optimum Manufacturing Condition of Composites -)

  • 이필우
    • Journal of the Korean Wood Science and Technology
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    • 제23권2호
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    • pp.55-69
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    • 1995
  • The primary objective of this research was to investigate optimum manufacturing condition of thin composite panels composed of sawdust, polyethylene film and polypropylene net. At the study the experiment was designed to make thin board in which sawdust offers effectiveness as core composing material, polyethylene as adhesive with added urea resin, and polypropylene as stiffness and flexibility in the composition panel. 100 types of thin composite panels were manufactured according to press-lam and mat-forming process of various hot pressing conditions(pressure, temperature and time). They were tested and compared with control boards on bending properties(MOR, MOE, SPL, WML), internal bond strength, thickness swelling, linear expansion and water absorption. At the same time the visual inspections of each types of panels were accomplished. The physical and mechanical properties of composite types passed by visual inspection were analyzed by Tukey's studentized range test. From the statistical analysis, the optimum manufacturing condition of thin composite panels were selected. Compared with two manufacturing processes, mat-forming process performed better than press-lam process in all tested properties. The optimum manufacturing conditions resulted from the experiment and statistical analysis were able to determine as following: the press temperature was shown the most good result at 130$^{\circ}C$ in mat forming process and 140$^{\circ}C$ press lam process, the press time 4 min in both processes, but the press pressure was 25-10kg/$cm^2$ in mat forming and 15k/$cm^2$ press lam process.

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