• Title/Summary/Keyword: Holding time

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A Study on Preparation and Characterization of Mullite Coated Film by Sol-Gel Process (졸-겔법에 의한 Mullite 코팅막의 제조 및 특성에 관한 연구)

  • 이용택;최영우;양중식
    • Journal of the Korean Ceramic Society
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    • v.34 no.6
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    • pp.611-619
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    • 1997
  • Optimal Mullite sol was synthesized by sol-gel process using Aluminium sec-butoxide(ASB), Tetraethoxysilane(TEOS) and then, Mullite films were dip-coated with various holding time in sol bath and heat-treated at 130$0^{\circ}C$ above for crystallization. The thickness of coated film increased linearly with holding time in sol bath and average pore size was controllable within 20~30$\AA$.

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Effects of Section Size and Melt Holding on the Mechanical Properties and Microstructure of High Silicon Ductile Cast Iron (고규소 구상흑연주철의 기계적 성질 및 미세조직에 미치는 단면 크기 및 용탕 유지의 영향)

  • Lee, Suk-Ju;Park, Ki-Ho;Lee, Sang-Hee;Kwon, Hae-Wook
    • Journal of Korea Foundry Society
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    • v.32 no.2
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    • pp.81-85
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    • 2012
  • The effects of section size and melt holding time on the mechanical properties and microstructure of high silicon ductile cast iron were investigated. The strength, elongation and hardness of the test specimen with smaller cross-section were higher than those with larger one. The nodule count and volume fraction of pearlite of the former were higher than those of the latter. The mechanical properties decreased with increased melt holding time before pouring. Nodularity and nodule count decreased and the volume fraction of pearlite rather slightly increased with it.

Studies on the Thermal Stability of Pork Loin Muscle in Previous Heating Temperatures and Holding Times by DSC (DSG를 이용한 예비 가열 온도 및 유지 시간에 따른 돈육 등심 근육의 열안정성에 관한 연구)

  • 김천제;송민석;이창현;이의수;조진국;이찬호;마기준
    • Food Science of Animal Resources
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    • v.18 no.4
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    • pp.358-363
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    • 1998
  • The objectives of this study were to evaluate the effect of previous heating temperature and holding times on the thermal behavior of pork loin muscle by DSC. Pork loin muscles were heated to achieve the following end-point temperatures: 40$^{\circ}C$, 50$^{\circ}C$, 60$^{\circ}C$, 70$^{\circ}C$, 80$^{\circ}C$ at heating rate = 10$^{\circ}C$/min. The first peak was disappeared when samples were initially heated to 50$^{\circ}C$ for 1 minute. As end-point temperature was raised, major peaks were progressively disappeared and peaks were lost completely at 80$^{\circ}C$. Especially, peaks were completely disappeared at 70$^{\circ}C$ for 10 minute. Increasing of exposure time to elevated temperature also increased denaturation, thereby reducing the area of the thermogram.

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An Integrated Inventory Model for a Three-Layer Supply Chain with Multiple Items (3단계 공급사슬에서 다완제품의 통합재고모형에 관한 연구)

  • Kim, Dae-Hong
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.37 no.4
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    • pp.116-125
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    • 2014
  • In this paper, we investigate an inventory and production system in a three-layer supply chain system involving a single supplier, single manufacturer and multiple retailers. Earlier study in this type of supply chain only consider a single raw material in order to produce single item, but we consider raw materials in order to produce multiple items. It is assumed that the cycle time at each stage is an integer multiple of the adjacent downstream stage. We develop an iterative solution procedure to find the order quantity for the multiple items and raw materials that minimizes the supply chain-wide total cost per unit time of the supplier and manufacturer's raw materials ordering and holding, setup and finished items holding, the retailer's ordering and inventory holding. Numerical examples are presented to show that the proposed heuristic gives good performance.

The Microbiological Quality Assessment of Chicken Soup Utilizing HACCP Model in a University Foodservice Establishment (대학 급식 시설의 닭곰탕 생산과정에서 HACCP Model 을 사용한 미생물적 품질 평가에 관한 연구)

  • Kwak, Tong-Kyung;Rew, Kyung
    • Korean journal of food and cookery science
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    • v.2 no.2
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    • pp.76-83
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    • 1986
  • Time and temperature, pH and Aw, and microbiological evaluation were made to identify critical control points during various phases in product flow of chicken soup preparation in a university foodservice establishment. The results are summarised as follows: 1) Time and temperature data indicated that the phases of cooling after cooking, post-preparation, and holding ingredients at room temperature before assembly were critical. 2) pH and Aw values were in favorable for microbial growth. 3) Microbiological data indicated that the phases of basic ingredients. post-preparation and holding ingredients before assembly were critical. 4) Critical control points identified were; basic ingredients, cooling after cooking, post-preparation, holding before assembly and service, and assembly and service. 5) Several guidelines were suggested for the effective qualitly control program.

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Predicting the FTSE China A50 Index Movements Using Sample Entropy

  • AKEEL, Hatem
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.3
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    • pp.1-10
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    • 2022
  • This research proposes a novel trading method based on sample entropy for the FTSE China A50 Index. The approach is used to determine the points at which the index should be bought and sold for various holding durations. The findings are then compared to three other trading strategies: buying and holding the index for the entire time period, using the Relative Strength Index (RSI), and using the Moving Average Convergence Divergence (MACD) as buying/selling signaling tools. The unique entropy trading method, which used 90-day holding periods and was called StEn(90), produced the highest cumulative return: 25.66 percent. Regular buy and hold, RSI, and MACD were all outperformed by this strategy. In fact, when applied to the same time periods, RSI and MACD had negative returns for the FTSE China A50 Index. Regular purchase and hold yielded a 6% positive return, whereas RSI yielded a 28.56 percent negative return and MACD yielded a 33.33 percent negative return.

A Study of Nucleation and Growth in Zinc Crystal Glaze by Firing Conditions (아연결정유의 제조에 있어서 소성조건에 따른 결정생성과 성장에 관한 연구)

  • Lee, Chi-Youn;Lee, Byung-Ha
    • Journal of the Korean Ceramic Society
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    • v.46 no.3
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    • pp.253-262
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    • 2009
  • The purpose of this study is to find out optimum conditions for zinc crystalline glaze under variables of firing: maximum firing temperature, crystal growth temperature, temperature increasing speed, annealing speed, holding time at maximum temperature and holding time at crystal growth temperature. Ferro Frit3110, ZnO and Quartz were used as starting materials and tested by three component system. The best result of test was selected and extended to its vicinity as five glaze formulas. And then the specimens were experimented by variable firing conditions and analyzed by crystal appearance observation, XRD, FT-IR and Raman spectroscopy. In result, main crystal was willemite in the zinc glazes. Some gahnite was detected in specimens which were fired at $1230^{\circ}C$, $1250^{\circ}C$ and $1270^{\circ}C$, however gahnite was not identified at $1300^{\circ}C$. Optimum zinc crystalline glaze was gained by following firing condition: temperature increasing speed $5^{\circ}C$/min, holding 1 h at $1270^{\circ}C$, annealing speed $3^{\circ}C$/min till $1170^{\circ}C$, holding 2 h at $1170^{\circ}C$ then naturally annealed.

Effects of Holding Temperatures on Microstructure and Mechanical Properties of CP Titanium and Ti-6Al-4V Alloy and Its low Temperature Brazing Characteristics (열노출 온도에 따른 CP 티타늄, Ti-6Al-4V 합금의 미세조직/기계적성질 변화 및 저온브레이징 특성)

  • Sun, J.H.;Shin, S.Y.;Hong, J.W.
    • Journal of the Korean Society for Heat Treatment
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    • v.23 no.1
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    • pp.3-9
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    • 2010
  • Titanium and its alloys were brazed in the range of $850-950^{\circ}C$ within 10 min. of brazing time using expensive infra red or other heating methods. However, brazing time needs to be extended to get temperature-uniformity for mass production by using continuous belt type furnace or high vacuum furnace with low heating rate. This study examined effects of holding temperature for 60 min, on microstructure and mechanical properties of titanium alloys. Mechanical properties of titanium alloys were drastically deteriorated with increasing holding temperature followed by grain growth. Maximum holding temperatures for CP (commercial pure) titanium and Ti-6Al-4V were confirmed as $800^{\circ}C$ and $850^{\circ}C$, respectively. Both titanium alloys were successfully brazed at $800^{\circ}C$ for 60 min. with the level of base metal strengths by using Zr based filler metal, $Zr_{54}Ti_{22}Ni_{16}Cu_8$.

The Cycle Time of the Vendor in a Single-Vendor Multi-Buyers Supply Chain (단일 공급자 다수 구매자 공급체인에서 공급자주기)

  • Chang, Suk Hwa
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.37 no.3
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    • pp.129-138
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    • 2014
  • This paper is to analyze the cycle time of the vendor in a single-vendor multi-buyers supply chain. The vendor is the manufacturer and the buyers are the retailers. The cycle time of the vendor is the elapse time from the beginning time of the production to the beginning time of the next production. The cycle time of the vendor that minimizes the total cost in a supply chain is analyzed. The cost factors are the production setup cost and the inventory holding cost of the vendor, the ordering cost and the inventory holding cost of the retailers. The cycle times of the vendor obtained with the costs of the vendor is compared with those obtained with the costs of the vendor and the retailers. Various numerical examples are tested if the cycle times of the vendor for both methods are the same.

A Study on Change Image According to Recumbent Position Holding Time for Patient Safety (In Chest Lateral Decubitus Examination) (환자안전을 고려한 횡와위 유지시간에 따른 영상변화에 관한 연구 (흉부 측와위 촬영 시))

  • Kim, Ki-Jin;Jeong, Chang-Min;Yoo, Se-Jong;Choi, Won-Jin;Kim, Jeong-Ho
    • Journal of the Korea Safety Management & Science
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    • v.18 no.1
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    • pp.147-152
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    • 2016
  • Chest lateral decubitus is a chest examination to determine the persence of pleural fluid in thorax. In this study, we prepare recumbent holding position time standard of chest lateral decubitus. The records of 15 patients with chest lateral decubitus between May and Jun. Recumbent holding time is 30, 60, 90, 120, 180, 210, 240 seconds. The result is fluid level change between 0.88mm to 9.63. Fluid heigh change between 9.9 percent to 42.5 percent. We can confirm fluid level change with chest decubitus image. The proper time for fluid level change is 180 seconds.