• 제목/요약/키워드: high temperature treatment

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Effects of Seed Pretreatment and Environment Controls on Germination of Atractylodes japonica Seeds (종자 전처리 및 환경조절이 삽주 종자 발아에 미치는 영향)

  • Jeon, Kwon Seok;Song, Ki Seon;Yoon, Jun Hyuck;Kim, Chang Hwan;Kim, Jong Jin
    • Korean Journal of Medicinal Crop Science
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    • v.21 no.5
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    • pp.394-400
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    • 2013
  • This study was carried out in order to examine the germination characteristics of Atractylodes japonica seeds, and it was to develop the more efficient pre-treatment and production system of the seeds. Experiment was performed by two ways-temperature control (10, 15, 20, $25^{\circ}C$) and shading treatment (full sunlight, 35, 50, 75, 95% of full sunlight). Seed pre-treatment before the each experiment was carried out by temperature (with low temperature and wetting treatment (LTW) for 0, 15, 30, 45 and 60 days) and shading treatment (with drying at room temperature (DRT), drying at low temperature (DLT) and water soaking (WS) for 48 hours). Seeds of A. japonica were germinated well under temperature control (overall 85.3~100%), especially high temperature. And, the seeds pre-treated with LTW for 45 days germinated with a 100% success rate. Under the surveying shading treatment, the highest germination rate was 95.8% with DRT and overall 63.2~95.8%. Germination rate under seeds with WS was 63.2~7.8%. As a result of surveying the whole experiment, A. japonica seeds don't need to pre-treat cause of high germination, but if it is performed with LTW for a certain period of time, it would be more productive.

Effects of Enhanced pCO2 and Temperature on Reproduction and Survival of the Copepod Calanus sinicus

  • Kang, Hyung-Ku;Lee, Chang-Rae;Kim, Dongseon;Yoo, Sinjae
    • Ocean and Polar Research
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    • v.38 no.4
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    • pp.303-314
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    • 2016
  • We tested the combined effects of increased partial pressure of $CO_2$ ($pCO_2$) and temperature on the reproduction and survival of the copepod Calanus sinicus from Asan Bay, the Yellow Sea under laboratory conditions to understand the impact of acidification on copepods. Egg production rate, survival rate, and fecal pellet production of C. sinicus were not affected by 1305 ppm $pCO_2$ or with combined treatments of temperature and $pCO_2$, including $8^{\circ}C$ and 289 ppm $pCO_2$ (ambient), $8^{\circ}C$ and 753 ppm $pCO_2$ (high $pCO_2$), $12^{\circ}C$ and 289 ppm $pCO_2$ (high temperature), and $12^{\circ}C$ and 753 ppm $pCO_2$ (greenhouse), for 5 or 10 d of exposure. However, egg hatching success of C. sinicus decreased significantly in the greenhouse treatment compared with the ambient or the high $pCO_2$ treatments. These results suggest that a combined treatment ($pCO_2$ and temperature) affected egg viability more than a single treatment($pCO_2$).

Study on Design of high Efficient Cooling System for Low Temperature Furnace in Semiconductor Processing (반도체 공정용 저온 열처리로의 고효율 냉각시스템 설계에 관한 연구)

  • Jeoung, Du-Won;Suh, Ma-Son;Kim, Kwang-Sun
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.4
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    • pp.71-76
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    • 2010
  • According to recent changes in industry for semiconductor devices, a low-temperature treatment has become a necessity. These changes relate to size refinement and the development of new materials. While variation in cooling efficiency does not affect the yield when using a high-temperature treatment, uniform cooling efficiency is necessary avoid "inconsistencies/bends" in low temperature treatments. However it is difficult to increase temperature stabilization in low temperature treatments. In this paper, using CFD (Computer Fluid Dynamics), we analyze and manipulate the design and input of the low-temperature system to attempt to control for temperature variations within the quartz tube, of which airflow appears to be a predominant factor. This simulation includes variable inputs such as airflow rate, head pressure, and design manipulations in the S.C.U. (Super Cooling Unit).

Effects of High Pressure/High Temperature Processing on the Recovery and Characteristics of Porcine Placenta Hydrolysates

  • Lee, Mi-Yeon;Choi, Ye-Chul;Chun, Ji-Yeon;Min, Sang-Gi;Hong, Geun-Pyo
    • Food Science of Animal Resources
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    • v.33 no.4
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    • pp.474-480
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    • 2013
  • This study was performed to investigate the effects of high pressure/high temperature (HPHT) treatment on the recovery efficiency and characteristics of porcine placenta hydrolysates. The placenta hydrolysates were characterized by solubility, free amino acid contents, gel electrophoresis, gel permeation chromatography (GPC) and amino acid composition. Placenta was treated at 37.5 MPa of pressure combined with various temperatures (150, 170, and $200^{\circ}C$) or various holding times (0, 30, and 60 min at $170^{\circ}C$). Insoluble raw placenta collagen was partially solubilized (> 60% solubility) by the HPHT treatment. Free amino group content of placenta collagen was increased from 0.1 mM/g collagen to > 0.3 mM/g collagen after HPHT treatment, reflecting partial hydrolysis of collagen. The molecular weight ($M_w$) distribution showed evidence of collagen hydrolysis by shifting of $M_w$ peaks toward low molecular weight when treated temperature or holding time was increased. Alanine (Ala), glycine (Gly), hydroxyproline (Hyp), and proline (Pro) contents increased after the HPHT treatments compared to a decrease in the others. In particular, the increase in Gly was obvious, followed by Hyp and Pro, reflecting that placenta hydrolysates were mainly composed of these amino acids. However, increasing temperature or holding time hardly affected the amino acid compositions. These results indicate that the HPHT treatment is advantageous to hydrolyze collagen derived from animal by-products.

Development of High-Temperature Heat Flux Gauge for Steel Quenching (강재 급속냉각용 고온 열유속게이지 개발)

  • Lee, Jungho
    • Journal of the Korean Society for Heat Treatment
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    • v.23 no.6
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    • pp.323-330
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    • 2010
  • The present study was motivated by increasing demands on quantitative measurements of the heat flux through the water cooling and quenching process of hot steel. The local heat flux measurements are employed by a novel experimental technique that has a function of high-temperature heat flux gauge in which test block assemblies are directly used to measure the heat flux variation during water cooling and quenching of hot steel. The heat flux can be directly achieved by Fourier's law and is also compared with numerical estimation which is solved by inverse heat conduction problem (IHCP). The high-temperature heat flux gauge developed in this study can be applicable to measure cooling rate and history during the actual cooling applications of steelmaking process. In addition, the measurement uncertainty of heat flux is calculated by a quantitative uncertainty analysis which is based on the ANSI/ASME PTC 19.1-2005 standard.

High Temperature Oxidation Behavior and Surface Defect in Fe-25Mn-1.5Al-0.5C Steel (Fe-25Mn-1.5Al-0.5C강의 고온 산화 거동과 표면 결함)

  • Park, Shin Hwa;Hong, Soon Taik;Kim, Tai Wung;Chung, In-Sang
    • Journal of the Korean Society for Heat Treatment
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    • v.13 no.3
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    • pp.158-162
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    • 2000
  • The high temperature oxidation behavior and the surface defect in Fe-25Mn-1.5A1-0.5C steel was investigated by XRD (X-ray Diffractin) and electron microscopy. The intra- and inter-granular oxides were formed by the selective oxidation of manganese and aluminum, which were identified to MnAl2O4 phase. Aluminum nitride (AlN) was formed in front of these oxides. The ${\gamma}$-matrix was transformed to ${\alpha}$- and ${\varepsilon}$- phases by the selective oxidation of manganese. The surface defect, micro-scab was induced by the difference of the high temperature ductility between the matrix and the inter-granular oxide.

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Effects of the Heat-Treatment on the Nutritional Quality of Milk - I. Historical Development of the Heat-Treatment Technology in Milk - (우유의 열처리가 우유품질과 영양가에 미치는 영향 - I. 우유 열처리 기술의 발달사 -)

  • Jung, Anna;Oh, Sejong
    • Journal of Dairy Science and Biotechnology
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    • v.34 no.4
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    • pp.271-278
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    • 2016
  • The main purpose of milk heat-treatment is to improve milk safety for consumer by destroying foodborne pathogens. Secondly, heat-treatment of milk is to increase maintaining milk quality by inactivating spoilage microorganisms and enzymes. Pasteurization is defined by the International Dairy Federation (IDF, 1986) as a process applied with the aim of avoiding public health hazards arising from pathogens associated with milk, by heat treatment which is consistent with minimal chemical, physical and organoleptic changes in the product. Milk pasteurization were adjusted to $63{\sim}65^{\circ}C$ for 30 minutes (Low temperature long time, LTLT) or $72{\sim}75^{\circ}C$ for 15 seconds (High temperature short time, HTST) to inactivate the pathogens such as Mycobacterium bovis, the organism responsible for tuberculosis. Ultra-high temperature processing (UHT) sterilizes food by heating it above $135^{\circ}C$ ($275^{\circ}F$) - the temperature required to destroy the all microorganisms and spores in milk - for few seconds. The first LTLT system (batch pasteurization) was introduced in Germany in 1895 and in the USA in 1907. Then, HTST continuous processes were developed between 1920 and 1927. UHT milk was first developed in the 1960s and became generally available for consumption in the 1970s. At present, UHT is most commonly used in milk production.

Effects of Heat Treatment on the Nutritional Quality of Milk: V. The Effect of Heat Treatment on Milk Enzymes (우유의 열처리가 우유품질과 영양가에 미치는 영향: V. 열처리가 우유효소에 미치는 영향)

  • Shin, Hanseob;Oh, Sejong
    • Journal of Dairy Science and Biotechnology
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    • v.36 no.1
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    • pp.49-71
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    • 2018
  • Heat treatment is the most popular processing technique in the dairy industry. Its main purpose is to destroy the pathogenic and spoilage bacteria in order to ensure that the milk is safe throughout its shelf life. The protease and lipase that are present in raw milk might reduce the quality of milk. Plasmin and protease, which are produced by psychrotrophic bacteria, are recognized as the main causes of the deterioration in milk flavor and taste during storage. The enzymes in raw milk can be inactivated by heat treatment. However, the temperature of inactivation varies according to the type of enzyme. For example, some Pseudomonas spp. produce heat-resistant proteolytic and lipolytic enzymes that may not be fully inactivated by the low temperature and long time (LTLT) treatment. These types of enzymes are inhibited only by the high temperature and short time (HTST) or ultra-high temperature (UHT) treatment of milk.

The Effects of Ni Content on Mechanical and Oxidation Resistance Properties of B2-NiAl Intermetallic Compounds (B2-NiAl 금속간 화합물의 기계적 성질 및 내산화성에 미치는 Ni함량의 영향)

  • Oh, Chang-Sup;Han, Chang-Suk
    • Journal of the Korean Society for Heat Treatment
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    • v.26 no.1
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    • pp.1-6
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    • 2013
  • The B2-ordered NiAl has attracted much attention as one of the candidates as a next generation high temperature material, because it has a high melting temperature, a low specific gravity and an excellent high temperature oxidation resistance. However, the application of NiAl to structural materials needs the improvement of its brittleness at room temperature. The study was carried out on the relation between several properties of NiAl and some variation of Ni content within NiAl phase, which means deviations from the stoichiometric composition. The main results were as follows; (i) Good ductility was obtained at the testing temperature more than 1073 K irrespective of Ni content. (ii) Increasing Ni content offered preferable tensile properties. (iii) Every NiAl with varying Ni contents showed the superior oxidation resistance.

Preparation of Green-Light Emitting BAM:Mn Phosphor Particles by High Temperature Spray Pyrolysis (고온 분무열분해 공정에 의한 녹색 발광의 BAM:Mn 형광체 합성)

  • Ju Seo Hee;Koo Hye Young;Kim Do Youp;Kang Yun Chan
    • Korean Journal of Materials Research
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    • v.15 no.8
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    • pp.496-502
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    • 2005
  • Green-light emitting $BaMgAl_{10}O_{19}:Mn^{2+}$ (BAM:Mn) phosphor particles were prepared by spray Pyrolysis. The effect of reactor temperature and flow rate of carrier gas in the spray Pyrolysis on the morphology, crystallinity and photoluminescence characteristics under vacuum ultraviolet were investigated. The morphology of the as-Prepared Particles obtained by spray Pyrolysis had spherical shape and non-aggregation characteristics regardless of the reactor temperature. The spherical shape of the as-prepared Particles obtained by spray pyrolysis at low temperature disappeared after Post-treatment. On the other hand the as-Prepared Particles obtained by spray Pyrolysis at $1600^{\circ}C$ maintained spherical shape and non-aggregation characteristics after post-treatment at $1400^{\circ}C$ for 3 h under reducing atmosphere. The BAM:Mn Phosphor Particles Prepared by spray Pyrolysis at different reactor temperatures had pure crystal structure and high photoluminescence intensities under vacuum ultraviolet after post-treatment. BAM:Mn phosphor particles prepared by spray Pyrolysis at low How rate of carrier gas had complete spherical shape and filed morphology and high photoluminescence intensity after post-treatment under reducing atmosphere.