• Title/Summary/Keyword: preheating

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Buffering Capacity of Dairy Powders and Their Effect on Yoghurt Quality

  • Kim, Miji;Oh, Sejong;Imm, Jee-Young
    • Food Science of Animal Resources
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    • v.38 no.2
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    • pp.273-281
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    • 2018
  • Preheating conditions (low-, medium-, and high heat-) did not significantly affect the buffering capacity (BC) of skim milk powder (SMP), whereas the level of demineralization significantly affected the BC of whey powders (WP). Heat treatment ($85^{\circ}C$ for 30 min) of both SMP and WP (90% demineralized) mixtures (88:12, 76:24, 64:36 and 52:48; SMP:WP) resulted in a reduced BC, and the extent of this reduction increased with the proportion of WP increased in the samples. High-buffering milk prepared by the addition of phosphate salts (40 mM $NaH_2PO_4$ and 60 mM $Na_2HPO_4$) delayed the rate of pH decline during yoghurt fermentation. The high-buffering yoghurt showed a significantly higher water holding capacity (WHC) than that of control yoghurt (p<0.05), as well as a more uniform and interconnected microstructure with small pore sizes than those of control yoghurt. No significant differences were found between high-buffering and control yoghurt regarding the viable bacterial counts of starter. The manipulation BC can potentially improve the quality characteristics of yoghurts, such as WHC and texture.

Study on Accuracy Evaluation of Laser Lens Changer for a Laser-Assisted Machining System (레이저보조가공에서 레이저 렌즈 교환장치의 정밀도 평가에 관한 연구)

  • Oh, Won-Jung;Kim, Eun-Joong;Lee, Choon-Man
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.8
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    • pp.687-692
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    • 2015
  • LAM (Laser-Assisted Machining) is an effective method for processing difficult-to-cut workpieces. The focal length of a LAM system is changed by the change of the workpiece shape during laser preheating; this problem is solved by changing the lens of the laser module. Linear- and rotary-type lens changers were developed to change the laser lens of a LAM system. The linear-type lens changer is operated by a motor with a ball-screw, and the rotary type is operated by a stepping motor. The natural frequency and structural stability of the laser lens changers were confirmed by using a finite element analysis; in addition, the functions of the lens changers were verified by measuring the iterative accuracy. The measured results show that the rotary-type lens changer is more accurate than the linear-type changer.

Effects of Particle Size and Gelatinization of Job's Tears Powder on the Instant Properties

  • Han, Sung-Hee;Park, Soo-Jea;Lee, Seog-Won;Rhee, Chul
    • Preventive Nutrition and Food Science
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    • v.15 no.1
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    • pp.67-73
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    • 2010
  • The effects of particle sizes (small, medium and large sizes) and gelatinization treatment on the changes of the instant properties of Job's tears powder were investigated. The degree of gelatinization on the different particle size samples of Job's tears powder was the highest in the small particle size, and it also showed an increasing trend regardless of pregelatinizing whether it is or not as the particle size decreased from large particle size to small particle size. The water solubility index of the pregelatinized samples was high compared to that of ungelatinized samples regardless of particle size and temperatures. The water absorption and swelling power increased as particle size and temperature were increased. The dispersibility and sinkability of ungelatinized sample was increased as particle size and temperature were increased and it also showed lower value regardless of particle size and temperature. However, the dispersibility and sinkability of pregelatinized samples were shown to have the opposite result, such that the smallest particle size of pregelatinized sample had the lowest sinkability (11.3%). The turbidity of the pregelatinized small particle size was the highest by a factor of 1.08.

A Method of Self-Arranging Solderballs for Packaging by Using Surface Energy Difference and Soldering (표면에너지 차이를 이용한 패키징용 솔더볼 자가정렬 및 솔더링 방법)

  • Hong, Jang-Won;Chang, Jong-Hyeon;Pak, Jung-Ho
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1531_1532
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    • 2009
  • This paper presents a method of self-arranging solderballs by using surface energy difference. After evaporating Au which has high surface energy on Si substrates, Teflon passivation layer which has low surface energy was patterned by lift-off process. Droplets formed only on the hydrophilic Au solderball lands by the surface energy difference, not the hydrophobic Teflon surface. Scattered solderballs sticked by themselves to the wetted solderball lands on the tilted substrate. After setting preheating of $200^{\circ}C$ and soldering of $245^{\circ}C$ hot plates, the solderballs were soldered on the solderball lands and two substrates were soldered together completely. After measuring the mechanical shear strength of the soldered substrates with solderballs of $3{\times}3$, $4{\times}4$ and $5{\times}5$ arrays. the calculated shear strength per one solderball was 1.1~2.4kgf as high as the previous report.

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Angle Calculation Rotation Angle of One-axis Manipulator in Laser Module (레이저모듈에서의 1-축 틸팅의 회전각 계산)

  • Jung, Dong-Won;Kim, Dong-Hong;Kim, Bong-Chun;Kim, Dong-Hyeon
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.5
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    • pp.506-509
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    • 2012
  • Laser assisted machining is the processing method that preheating brittle materials by laser heat source and cutting the soften area. This processing applied to various industries because it can be cutting difficult-to-cut materials. However, the laser assisted machining appeared the limitations of processing for equipped with the spindle. So, it assumed separate model that spindle and laser assisted machining. In feed, the calculation of changing the angle of the laser module according to preheat point and the shape of the feed is important and it tried easy calculating changing angle of 1-axis Manipulator in separate model. In 3 types feed shape, angle of 1-axis Manipulator was calculated when fixed and moved in the outside of spindle. In this study, suggest 2 types of methods for laser module when fixed and moved.

Parametric Study of an Integrated Steam Methane Reformer with Top-Fired Combustor (통합 수증기 개질 시스템의 작동 조건에 대한 수치적 연구)

  • Noh, Jung-Hun;Jung, Hye-Mi;Kim, Donghee;Um, Sukkee
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.156.1-156.1
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    • 2011
  • It is of great importance to predict operating parameter characteristics of an integrated fuel processor by the increased life-time and system performance. In this study, computational analysis is performed to gain fundamental insights on transport phenomena and chemical reactions in reformer which consists of preheating, steam reforming, and water gas shift reaction beds. Also, a top-fired burner locates inside of the reforming system. The combustor is providing thermal energy necessary for the steam reforming bed which is a endothermic catalytic reactor. Two-dimensional numerical model of the integrated fuel processing system is introduced for the analysis of heat and mass transport phenomena as well as surface kinetics and catalytic process. A kinetic model was developed and then computational results were compared with the experimental data available in the literature. Subsequently, parameter study using the validated steam methane reforming model was conducted by considering operating parameters, i.e. steam to carbon ratio and temperature.

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Modification of Functionality for Lysozyme (Lysozyme의 기능성 개선)

  • Kim, Hyun-Ku
    • Applied Biological Chemistry
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    • v.37 no.6
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    • pp.456-462
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    • 1994
  • Lysozyme-dextran hybrids were prepared by incubated storage at $60^{\circ}C$ and 80% relative humidity for 16 days. The emulsifying properties of the hybrids were about 14 times higher than those of native lysozyme and were about 3 times higher than those of commercial emulsifiers. Lytic activity of the hybrids remained about 83% that of native lysozyme when mesured against Micrococcus lysodeikticus as a substrate. The excellent emulsifying properties of the hybrids were maintained even at pH 3 and were further improved at pH 10. The emulsifying properties of the hybrids were greatly improved by preheating the hybrids at $100^{\circ}C$. In addition the lysozyme-dextran hybrids showed an antimicrobial effect on Gram-negative bacteria.

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Design of High Frequency Casting Machine for Dental using Induction Heating System (유도가열 시스템을 적용한 치과용 고주파 주조기 설계)

  • Song, Seung-Gun;Lim, Sang-Kil;Lee, Sang-Hun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.8
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    • pp.79-87
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    • 2012
  • Currently, The method to produce a brewing body for dentistry supplementation water produces a brewing body by fabrication, burying and it is heat wish in city gas and oxygen. It uses an original judgment found airplane the brewing body uses a spring of the back wait that melting temperature dissolved various alloys in by a blow pipe, and to generate centrifugal force and produces it. In addition, because it uses preheating to dissolve an alloy in general, it is hard to regulate the appropriate melting temperature of the alloy and brewing time and generates a brewing defect hereby same as gas industry and pinhole and shows the defect of the supplementation thing due to the super-heating. In this paper, We developed the high induction heating system which it could set brewing time,temperature and had durability and security,by the kind of the alloy to produce a high quality prosthetic thing brewing body.

Microwave Cure of Rubber Compound for Tire Tread (타이어 트레드용 고무배합물의 마이크로파 가황)

  • Han, Shin;Kang, Yong-Gu;Sohn, Bong-Young;Oh, Sei-Chul;Park, Chan-Young
    • Journal of the Korean Society of Industry Convergence
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    • v.2 no.1
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    • pp.69-75
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    • 1999
  • Intending to develop a new rubber curing process using only microwave, the both the characteristics of cure and the mechanical properties of rubbers for the tire tread, for which a green styrene-butadiene compounds had been cured with 2.45 GHz microwave, have been compared with those of the custom thermal cured rubber. The unintentional hot spot formation in the compound during the microwave curing has not found where the compound has a microwave absorbing ceramic powders in 4.18 weight percents and the supplying voltage has been adjusted to 90 volts. The new microwave process accomplished preheating to 418K in a quarter of the thermal cure time. The average tensile strength of the microwave-cured rubber indicating $190kg/cm^3$ was compatible to that of the thermal cure. In conclusion, the new microwave cure had approved to be applicable in a commercial plant.

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Characterization of Soldering Property on Heating Condition by Infrared Lamp Soldering Process for C-Si Photovoltaic Modules (적외선 램프 가열방식을 이용한 태양전지 셀의 솔더링 공정 및 열처리 조건 별 특성 평가)

  • Son, Hyoun Jin;Lee, Jung Jin;Kim, Sung Hyun
    • Current Photovoltaic Research
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    • v.4 no.2
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    • pp.59-63
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    • 2016
  • A key point of a soldering process for photovoltaic (PV) modules is to increase an adhesive strength leading a low resistivity between ribbon and cell. In this study, we intended to optimize a heating condition for the soldering process and characterize the soldered joint via physical and chemical analysis methods. For the purpose, the heating conditions were adjusted by IR lamp power, heating time and hot plate temperature for preheating a cell. Since then the peel test for the ribbon and cell was conducted, consequently the peel strength data shows that there is some optimum soldering condition. In here, we observed that the peel strength was modified by increasing the heating condition. Such a soldering property is affected by a various factors of which the soldered joint, flux and bus bar of the cell are changed on the heating condition. Therefore, we tried to reveal causes determining the soldering property through analyzing the soldered interface.