• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.528-534
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• 2020

The early development and use of plate heat exchangers (PHE) were in response to stringent statutory requirements from dairy products in the late 19th century, but PHEs were not exploited commercially until the 1920s. Since then, although the basic concept of PHEs has changed little, its design and construction have progressed significantly to accommodate higher temperatures and pressures, as well as large heat exchanging capacities. The development of current chevron-type corrugated heat plates has been ongoing since the oil shock in the 1970s to improve energy efficiency. The development trend of PHEs is consistent with the development of larger heat plates with better thermal efficiency, lower pressure drop, and good flow distribution. In this study, the thermal performance of small heat plates (PHE-S) and large heat plates (PHE-L) with the same plate depth and corrugation pitch were analyzed experimentally for each channel (H, M, and L type) to suggest development directions of heat plates. The test results showed that for the convectional heat transfer coefficient, the PHE-S was on average, 16.5% higher in the H type, 25% higher in the M type, and 40% higher in the L type than PHE-L. In the case of the pressure drop, the PHE-S was 19% higher in the H type, 46% higher in the M type, and 61% higher in the L type than PHE-L. These results were attributed to the differences in fluid distribution areas between the PHE-S and PHE-L, among other potential causes.

• Journal of Animal Science and Technology
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• v.62 no.2
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• pp.263-275
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• 2020

Studies on promoting milk protein yield by supplementation of amino acids have been globally conducted. Nevertheless, there is a lack of knowledge of what pathways affected by individual amino acid in mammary epithelial cells that produce milk in practice. Phenylalanine (PHE) and valine (VAL) are essential amino acids for dairy cows, however, researches on mammary cell levels are still lacking. Thus, the aim of this study was conducted to evaluate the effects of PHE and VAL on milk protein synthesis-related and energy-mediated cellular signaling in vitro using immortalized bovine mammary epithelial (MAC-T) cells. To investigate the effects of PHE and VAL, the following concentrations were added to treatment medium: 0, 0.3, 0.6, 0.9, 1.2, and 1.5 mM. The addition of PHE or VAL did not adversely affect cell viability compared to control group. The concentrations of cultured medium reached its maximum at 0.9 mM PHE and 0.6 mM VAL (p < 0.05). Therefore, aforementioned 2 treatments were analyzed for proteomics. Glucose transporter 1 and mammalian target of rapamycin mRNA expression levels were up-regulated by PHE (166% and 138%, respectively) (p < 0.05). Meanwhile, sodium-dependent neutral amino acids transporter type 2 (ASCT2) and β-casein were up-regulated by VAL (173% in ASCT2, 238% in and 218% in β-casein) (p < 0.05). A total of 134, 142, and 133 proteins were detected in control group, PHE treated group, and VAL treated group, respectively. Among significantly fold-changed proteins, proteins involved in translation initiation or energy metabolism were detected, however, expressed differentially between PHE and VAL. Thus, pathway analysis showed different stimulatory effects on energy metabolism and transcriptional pathways. Collectively, these results showed different stimulatory effects of PHE and VAL on protein synthesis-related and energy-mediated cellular signaling in MAC-T cells.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.235-240
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• 2007

Performance of an air-cooled plate heat exchanger (PHE) was evaluated in this study. The PHE was manufactured in two types of single-wave and double-wave plates in parallel assembly. The heat exchanger aims to substitute open-loop cooling towers with closed-loop water circulation, which guarantees cleanliness and compactness. In this study, prototype single-wave and double-wave PHEs were designed and tested in a laboratory scale experiments. From the tests, the double-wave PHE shows approximately 50% enhanced heat transfer performance compared to the single-wave PHE. However, the double-wave PHE costs 30% additional pressure drop. For the commercialization, a wide channel design for air flow would be essential for performance and reliability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.827-828
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• 2012

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1976.04a
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• pp.182.5-183
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• 1976

Mucor-rennin(MR)과 Calf-rennin(CR)을 k-Ca-sein에 반응시켜 para-k-Casein과 macropeptide를 분리하였다. 분리한 Para-k-casein과 macropeptide에 대한 전기영동, 원소분석을 행하였다. MR로 분해하여 얻은 para-k-casein의 N-미단은 없고, Cpase를 반응시켰을 때 Paper chromatography 상에서 Phe, Leu를 확인할 수 있었다. Macropeptide의 N미단은 Edman법에 의하여 Met으로 확인되였다. 이 결과로부터 CR은 para-k-casein의 C미단 Phe과 macropeptide의 N미단 Met간의 결합 즉 Phe-Met결합을 가수분해한다고 생각할 수 있다. 그리고 CR을 k-casein에 작용시켜 얻은 기질특이성은 MR의 결과와 같았다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.114-117
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• 2002

Sorption and desorption studies were conducted to evaluate several media as a potential biobarrier for the remediation of groundwater contaminated with hydrophobic organic compounds (HOCs). Pahokee and Bion peats, Devonian Ohio shale, vermicompost, and 50% HDTMA-montmorillonite were used as model sorbents. Sorption and desorption isotherms were determined using the radiolabeled phenanthrene (Phe). Sorption capacity of Phe on several sorbents was in the order Ohio shale > 50% HDTMA-montmorillonite > vermicompost > Pahokee peat. Mineralization kinetics was investigated for Phe-sorbed sorbents using Pseudomonas putida 17484. Among the tested sorbents, active biodegradation of Phe was observed in shale and vermicompost: degradation in shale exhibited little lag time while that in shale showed a significant lag time. Results of this study indicate that sorbents used in this work can be utilized as permeable reactive biobarrier media for the remediation of HOC-contaminated groundwater.

• Korean Journal of Food Science and Technology
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• v.2 no.2
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• pp.43-48
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• 1970

When of the synthetic peptides were subjected hydrolysis with Mucor-rennin which crystalline milk-clotting enzyme from Mucor pusillus, the peptides of Z-L-Glu-L- Phe-OH, Z-L-Phe-L-Tyr-OH, Z-L-Phe-L-Leu-OH, Z-L-Tyr-L-Leu and Z-L-Glu-L-Phe-OH, were found to be hydrolysis.

• Bulletin of the Korean Chemical Society
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• v.20 no.7
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• pp.777-780
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• 1999

N-Chloroacetyl-N-hydroxy- β-Phe-NHMe and N-chloroacetyl-N-hydroxy-α-Phe-OMe were designed, synthe-sized and evaluated as irreversible inhibitors of thermolysin, a representative zinc protease. Analysis of kinetic data of the enzymic activity of thermolysin in the presence of these inhibitors revealed that they are indeed potent inactivators of thermolysin having the k(inact)/K(I ) values of 3.06 and 0.05 M (-1) s(-1) , respectively. We have established that the inhibitory activity of N-chloroacetyl-N-hydroxy-β-Phe-NHMe stems mainly from the (R)-enantiomer that belongs to the "L" series. The (R)-enantiomer is also responsible for the inactivation in the case of N-chloroacetyl-N-hydroxy-α-Phe-OMe, but this enantiomer belongs to the "D"-series.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.32-35
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• 1999

Poly(arylene ether phosphin oxide) (PEPO), Udel$^{\circledR}$ P-1700, Ultem$^{\circledR}$ 1000. poly(hydroxy ether) (PHE), carboxy modified poly(hydroxy ether)(C-PHE) and poly(hydroxy ether ethanol amine) (PHEA) were utilized for a coating of carbon fibers. Interfacial shear strength(IFSS) of polymers to carbon fibers was also evaluated in order to understand the adhesion mechanism. IFSS was measured via micro-droplet tests, and failure surfaces were analyzed by SEM. Diffusion between polymer and vinyl ester resin was investigated as a function of styrene content; 33. 40 or 50wt.% and the solubility parameters of polymers were calculated. The results were correlated to the interfacial shear strength. The highly enhanced interfacial shear strength (IFSS) was obtained with PEPO coating, and marginally improved IFSS with PHE, Udel$^{\circledR}$ and C-PHE coatings, but no improvement with PHEA and Ultem$^{\circledR}$ coatings.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.2093-2094
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• 2005