• 제목/요약/키워드: high pressure treatment

검색결과 1,118건 처리시간 0.024초

정수처리 응집·한외여과 시스템의 연속운전을 통한 운전조건 결정 및 막오염 특성에 관한 연구 (Determination of operating factor and characteristics of membrane fouling on hybrid coagulation pretreatment-UF system in drinking water treatment)

  • 문성용;윤종섭;김승현
    • 상하수도학회지
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    • 제22권2호
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    • pp.267-274
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    • 2008
  • This study is about efficiency of pretreatment process and operating factor to membrane process at continuous coagulation/ultrafiltration process in water treatment. The capacity of pilot plant was $0.06{\beta}(C)/d$. The raw water used was from Nakdong stream which was characteristized by high organic matter and high turbidity. The result of the test was that coagulation is good process as to high removal rate to organic matter and turbidity but It caused problem to membrane pore blocking. This paper is to determine the membrane fouling potential under different membrane flux, backwash pressure and linear velocity. Backwash pressure and flux is important parameter on operation of membrane system. Those are directly affected on membrane system. When backwash pressure increased from 150 kPa to 200 kPa, the result showed that fouling (pressure increase rate) changed from 3.69 kPa/h to 0.93 kPa/h and the recovery rate changed from 90.7 % to 82.0 %. Linear velocity had slightly effect on fouling. Linear velocity increased from 0.2 m/s to 0.5 m/s, the corresponding pressure rate changed from 0.93 kPa/d to 0.77 kPa/d.

Inactivation Kinetics of Listeria innocua ATCC 33090 at Various Temperature Heating-up and Pressure Building-up Rates

  • Ahn, Ju-Hee;Balasubramaniam, V.M.
    • Food Science and Biotechnology
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    • 제16권2호
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    • pp.255-259
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    • 2007
  • The effects of temperature heating-up rate and pressure building-up phase on the inactivation of Listeria innocua ATCC 33090 were evaluated in buffered peptone water. The number of L. innocua was reduced by 5.57 and 6.52 log CFU/mL during the nonisothermal treatment (the come-up time followed by isothermal process) and the isothermal treatment, respectively, at $60^{\circ}C$. When compared to the isothermal treatment (0.76$33.2^{\circ}C/min$ of temperature heating-rate. The effect of the combined high pressure and thermal processing on the inactivation of L. innocua increased with increasing pressure and temperature. At all temperature levels from 40 to $60^{\circ}C$ under 700 MPa, L. innocua was not detected by enrichment culture (>7 log reduction).

Effects of High Pressure Treatment on Cured Colour Development and Residual Nitrite Level in Model System

  • Hong, Geun-Pyo;Park, Sung-Hee;Kim, Jee-Yeon;Ko, Se-Hee;Lee, Sung;Min, Sang-Gi
    • 한국축산식품학회:학술대회논문집
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    • 한국축산식품학회 2006년도 정기총회 및 제37차 춘계 국제학술발표대회
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    • pp.325-328
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    • 2006
  • In low nitrite level, treatment of combined with pressure and thermal processing improved cured meat colour comparing with that of only thermal processing. However, visual colour of only pressurised treatment could not be improved at low nitrite level. Pressure treatment could develop cured meat colour when high nitrite level was added. Moreover, pressurisation combined with thermal processing decreased nitrite residuals compared to thermal processing. Therefore the results indicated that pressurisation combined with thermal processing had potential benefits in appearance of cured meat products, promising improved food safety.

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Stability of Proteasomes Extracted from Pressurized, Aged Skeletal Muscles

  • Yamamoto, Shuhei;Suzuki, Atsushi;Nishiumi, Tadayuki
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권2호
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    • pp.282-288
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    • 2009
  • The present paper describes the effects of pressure and post-mortem aging treatments on in situ proteasome activity in rabbit and bovine skeletal muscles. Synthetic peptide hydrolyzing activity of rabbit proteasomes remained in the muscle after exposure to pressures up to 100 MPa. However, when a pressure of 400 MPa or more was applied, proteasomes were markedly inactivated. The extraction of proteasomes from excessively pressurized muscle appeared to be difficult. Proteasomes in aged muscle remained relatively stable throughout the aging process, with activity after 168 h (7 days) being 35%, 48%, 53% and 31% of the 0 h post-mortem LLVY, LSTR, AAF and LLE total hydrolyzing activities, respectively. The synthetic peptide hydrolyzing activities of bovine muscle proteasomes were similar to those of rabbit skeletal muscle proteasomes. The results suggest that synthetic peptide hydrolyzing activity remains in muscle exposed to relatively low pressures. Furthermore, it is known that high-pressure treatment induces fragmentation of myofibrils, modification of actin-myosin interaction and activation of intramuscular proteinases, cathepsins and calpains. Thus, proteasomes are probably involved in the tenderization process in combination with other intramuscular proteinases under high-pressure conditions. Our findings confirmed that proteasomes play a role in meat tenderization induced by high-pressure treatment or aging.

배추의 압축탈수특성에 관한 연구 (Compression and Dewatering of Chinese Cabbage)

  • 김영중;이동현;이용범
    • Journal of Biosystems Engineering
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    • 제19권1호
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    • pp.3-8
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    • 1994
  • An experiment on the expression and dewatering of chinese cabbage was conducted in order to investigate its dewatering behavior. Chopped cabbage was packed into cylinder and pressed by piston upto the predetermined pressure on Instron-1000. The rates of dewatering were affected domintantly by the applied pressure, but not significantly by the packed amount of cabbage in the cylinder. The pressure effect was increased very abruptly at first, but the increase rate was very low at high pressure greater than 20 MPa, showing great deviation from linear dependence of flow rate on pressure in Darcy's Law. Therefore, water expression from cabbage was not Newtonian flow of water through cell wall. In fact, the squeezed water contained a lot of solid particles, about 3% of solid cabbage particles, showing destruction of cell wall. It appeared that compression and dewatering of vegetable wastes in the low pressure. under 20 MPa, is more desirable for later treatment of the dewater. More researches are needed in order to develop a treatment method for the solid particles in the expressed water before an expeller treatment system can be applied to vegetable wastes.

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고압 처리 후 가공한 반건조 병어의 품질특성과 저장성 (Quality Characteristics and Storage Stability of Semi-Dried Silver Pomfret (Pampus argenteus) Processed with Treatment of High Hydrostatic Pressure)

  • 김민지;이수정;김종태
    • 한국식품영양학회지
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    • 제27권5호
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    • pp.805-816
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    • 2014
  • We investigated the quality characteristics and resulting sensory evaluation of semi-dried silver pomfret treated with high hydrostatic pressure (HHP) processing and brining for 14 days at 4 and $10^{\circ}C$ to evaluate the effects of treatment with HHP processing. HHP treatment and brining could cause compaction of fibers and the space between muscle. The G' values of all samples were higher than the G" values and the tan ${\delta}$ values of the tissue ranged from 0.222 to 0.251 with no further changes observed during storage. HHP treatment and brining significantly increased the total color difference, and the HHP and brine-treated group scored significantly higher than the others in terms of sensory evaluation. HHP treatment combined with brining could have a significant effect on the quality characteristics of the semi-dried products and their storage stability, and it is suggested from the results that they may have the potential to satisfy the requirements to produce commercially marketable food grade products.

염농도가 다른 새우젓에 존재하는 유해가능 세균의 초고압 살균 (High Hydrostatic Pressure Sterilization of Putrefactive Bacteria in Salted and Fermented Shrimp with Different Salt Content)

  • 목철균;송기태
    • 한국식품과학회지
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    • 제32권3호
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    • pp.598-603
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    • 2000
  • 열처리에 의한 식품의 성분변화 손실을 줄이기 위한 비열처리 기술중 하나로 새롭게 주목받고 있는 초고압 처리를 적용하여 저염발효 새우젓의 저장성을 증진시키고자 하였다. 염농도 8%로 $20^{circ}C$에서 6주간 발효한 새우젓의 Vibrio 선택배지 검출균은 $1.6{\times}10^3\;CFU/g$, Staphylococcus 선택배지 검출균은 $9.3{\times}10^3\;CFU/g$이었고 18%의 새우젓에서의 Vibrio 선택배지 검출균은 $1.4{\times}10^4\;CFU/g$, Staphylococcus 선택배지 검출균은 $1.7{\times}10^\;CFU/g$이었다. 새우젓을 압력 $3,500{sim}6,500$기압, 시간 $5{\sim}40$분의 범위로 초고압 살균하였을 때 압력과 처리시간이 증가할수록 살균효과가 증가되었으며 사멸패턴은 1차반응으로 확인되었다. 압력을 6,500기압으로 고정하고 10분 동안 처리하였을 때 유해가능 세균은 본 연구방법의 검출한계인 $10^2\;CFU/g$수준에서는 경출되지 않았다. Vibrio선택배지 검출균의 $D_p$값은 염농도 8%보다 18%에서 더 높았으며 Staphylococcus 선택배지 검출균은 18%보다 8%에서 더 높은 값을 보였다. Vibrio 선택배지 검출균과 Staphylococcus 선택배지 검출균 모두 염농도 8%에서의 $Z_p$값이 염농도 18% 경우보다 높은 값을 보였다. 초고압 공정은 저염발효 새우젓의 살균에 응용될 수 있었으며 최적 고압살균조건은 6,500기압에서 10분간 처리하는 것이었다.

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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
    • 한국축산식품학회지
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    • 제33권4호
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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.

대기압 아르곤 플라즈마 처리를 통한 IGZO TFT의 전기적 특성 향상 연구 (High Performance InGaZnO Thin Film Transistor by Atmospheric Pressure Ar Plasma Treatment)

  • 정병준;정준교;박정현;김유정;이희덕;최호석;이가원
    • 반도체디스플레이기술학회지
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    • 제16권4호
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    • pp.59-62
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    • 2017
  • In this paper, atmospheric pressure plasma treatment was proposed for high performance indium gallium zinc oxide thin film transistor (IGZO TFT). RF Ar plasma treatment is performed at room temperature under atmospheric pressure as a simple and cost effective channel surface treatment method. The experimental results show that field effect mobility can be enhanced by $2.51cm^2/V{\cdot}s$ from $1.69cm^2/V{\cdot}s$ to $4.20cm^2/V{\cdot}s$ compared with a conventional device without plasma treatment. From X-ray photoelectron spectroscopy (XPS) analysis, the increase of oxygen vacancies and decrease of metal-oxide bonding are observed, which suggests that the suggested atmospheric Ar plasma treatment is a cost-effective useful process method to control the IGZO TFT performance.

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Effects of Combination Treatments of Nisin and High-intensity Ultrasound with High Pressure on the Functional Properties of Liquid Whole Egg

  • Lee, Dong-Un
    • Food Science and Biotechnology
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    • 제18권6호
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    • pp.1511-1514
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    • 2009
  • Liquid whole egg (LWE) was subjected to high hydrostatic pressure (HHP), a consecutive combination of nisin and HHP (nisin-HHP), or a consecutive combination of ultrasound and HHP (ultrasound-HHP), and functional properties of processed LWE were compared to those of raw LWE. Little changes in foaming and emulsifying properties were observed by the application of HHP alone and the combined process of nisin and HHP. In contrast, ultrasound-HHP combination resulted in significant changes in color, foaming, and emulsifying properties. The maintenance of functional properties after HHP treatment agreed with expectation, because the HHP processing condition had been selected where minimal rheological changes had occurred.