• 한국주조공학회지
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• 제43권5호
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• pp.223-229
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• 2023

In this study, STS316L produced by a double-melting process involving vacuum induction melting (VIM) and vacuum arc remelting (VAR) was subjected to extrusion and drawing to form a tube and was subsequently electrolytic polished (EP). The grain size of the obtained STS316L without EP was approximately 55 ㎛, with no difference found after EP. The thickness of the EP layer was measured by AES and TEM, showing values of approximately 10 nm and 15 nm, respectively. After EP, the Cr/Fe and CrO/FeO ratios of the passive layer increased from 1.48 to 1.62 and from 2.15 to 2.26, respectively, while the surface roughness decreased significantly from 0.255 to 0.024 ㎛. Consequently, the corrosion rate decreased in both NaCl and HCl solutions after the EP process. Additionally, the amounts of eluted Cr and Fe ions were reduced from 1.2 to 0.8 ppb and 10.3 to 0.8 ppb, respectively. Furthermore, polarization tests revealed that STS316L treated with EP required a lower current density to reach a passive state, indicating that corrosion behavior was retarded.

• 농약과학회지
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• 제18권4호
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• pp.422-428
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• 2014

딸기 근권에서 분리한 내생균 중 고추역병균 방제 및 고추생육촉진 효과가 우수한 균주를 선발하였다. Pseudomonas fluorescen EP103으로 명명된 내생균주는 다른 내생균주와 비교하여 식물의 뿌리 길이와 생체 중이 크게 증가하였다. 고추역병에 대한 온실검정에서 EP103처리는 방제가 78.7%을 나타냈으며 항균력 실험결과 고추역병균을 직접 억제하지는 않았다. EP103이 처리된 고추에서는 PR1, PR10등의 병저항성 유전자가 발현되었으며 EP103의 PCR분석 결과 피올테오린, 파이로니트린, 하이드로젠 싸이아나이드, 오르화미드 등의 유용유전자를 함유하고 있음이 밝혀졌다. 따라서 본 균주는 고추역병의 생물 방제용으로 활용할 가치가 있는 것으로 판단된다.

• 한국수산과학회지
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• 제47권5호
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• pp.577-581
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• 2014

The aim of this study was to investigate the effect of diet extruder conditions, such as feed-loading rate and screw speed, on growth performance and biochemical responses in olive flounder Paralichthys olivaceus. Over 8 wks, we used four identical diets (triplicated per treatment) with differing ratios of feed-loading rate (kg/h):screw speed (rpm/min) in a laboratory-scaled twin-screw extruder of 50:640, 80:640, 120:640, and 80:400, designated as EP1, EP2, EP3, and EP4, respectively. Screw speed impacted the buoyancy of experimental diets. Diets produced at a screw speed of 640 rpm/min floated for > 24 hrs, whereas those produced at a speed of 400 rpm/min sank between 10 s and 5 min. Fish that were fed EP1 and EP4 diets grew significantly faster than those fed EP2 and EP3 diets. Fish fed EP1 diets ate and gained weight most efficiently among treatments, a result that is likely to be related to feed-loading rate, i.e., ingredients extruded at a low feed-loading rate may have more time to cook in the pre-conditioner of the extruder. A cooked diet may be easier to digest in fish. Fish fed EP4 diets also showed significant weight gain, as compared to those fed EP2 and EP3 diets. However, we found no differences among treatments in proximate compositions of dorsal muscle, liver, and viscera of fish. Our results suggest that extruder conditions, may influence feed quality, impacting feed efficiency and growth of fish.

• 한국양식학회지
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• 제18권2호
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• pp.98-106
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• 2005

본 연구는 지질과 단백질 함량이 다른 두 종류 부상사료의 적정 공급횟수와 공급율을 조사하기 위해 평균 체중 55.1 g의 넙치를 각 수조마다 20마리씩 3반복으로 수용하여 58일 동안 사육하였다. 사료공급휫수는 1일 3회, 1일 2회 및 1일 1회로 설정하였으며 사료 공급량은 만복 및 만복의 80%로 각각 설정하였다. 생존율은 모든 실험 구에서 82% 이상이였으며, 평균 증중량은 EP1의 1일 2회 만복 공급구가 가장 높은 증중량을 보였으며, EP1의 1일 2회 및 3회 제한 공급구와 EP2의 1일 2회 제한 공급구가 가장 낮았다. 일일사료섭취율은 EP1의 1일 2회와 1일 3회 만복 공급구가 가장 높았고, EP2의 1일 3회 만복 공급구와 유의한 차이가 없었다(P>0.05). 사료효율과 단백질효율은 사료 조성, 공급횟수 및 공급을 모두 영향을 받지 않았다(P>0.05). 사육실험 종료시, 근육의 수분 함량은 동일한 사료와 공급휫수에서 제한 공급구가 만복 공급구에 비해 높았다. 이상의 결과들로 보아 평균체중 $55{\sim}90g$인 넙치의 성장을 위해 EP1과 EP2를 1일 2회 만복으로 공급하는 것이 적합할 것으로 판단된다.

• 대한화학회지
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• 제14권2호
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• pp.179-184
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• 1970

Four-ball EP and wear testers were used to study the effects of thickeners and additives on the EP and wear properties of some Korean greases. The EP property improved in the order of Li < Al < Ca, and the concentration of thickener did not affect the property when the same base oil and additives were used. The anti-wear property was improved in general when the additives were used.

• Molecules and Cells
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• 제25권1호
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• pp.30-42
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• 2008

The disease-specific (dsp) region and the hypersensitive response and pathogenicity (hrp) genes, including the hrpW, $hrpN_{Ep}$, and hrpC operons have previously been sequenced in Erwinia pyrifoliae WT3 [Shrestha et al. (2005a)]. In this study, the remaining hrp genes, including the hrpC, hrpA, hrpS, hrpXY, hrpL and hrpJ operons, were determined. The hrp genes cluster (ca. 38 kb) was comprised of eight transcriptional units and contained nine hrc (hrp conserved) genes. The genetic organization of the hrp/hrc genes and their orientation for the transcriptions were also similar to and collinear with those of E. amylovora, showing ${\geq}80%$ homologies. However, ORFU1 and ORFU2 of unknown functions, present between the hrpA and hrpS operons of E. amylovora, were absent in E. pyrifoliae. To determine the HR active domains, several proteins were prepared from truncated fragments of the N-terminal and the C-terminal regions of $HrpN_{Ep}$ protein of E. pyrifoliae. The proteins prepared from the N-terminal region elicited HR, but not from those of the C-terminal region indicating that HR active domains are located in only N-terminal region of the $HrpN_{Ep}$ protein. Two synthetic oligopeptides produced HR on tobacco confirming presence of two HR active domains in the $HrpN_{Ep}$. The HR positive N-terminal fragment ($HN{\Delta}C187$) was further narrowed down by deleting C-terminal amino acids and internal amino acids to investigate whether amino acid insertion region have role in faster and stronger HR activity in $HrpN_{Ep}$ than $HrpN_{Ea}$. The $HrpN_{Ep}$ mutant proteins $HN{\Delta}C187$ (D1AIR), $HN{\Delta}C187$ (D2AIR) and $HN{\Delta}C187$ (DM41) retained similar HR activation to that of wild-type $HrpN_{Ep}$. However, the $HrpN_{Ep}$ mutant protein $HN{\Delta}C187$ (D3AIR) lacking third amino acid insertion region (102 to 113 aa) reduced HR when compared to that of wild-type $HrpN_{Ep}$. Reduction in HR elicitation could not be observed when single amino acids at different positions were substituted at third amino acids insertion region. But, substitution of amino acids at L103R, L106K and L110R showed reduction in HR activity on tobacco suggesting their importance in activation of HR faster in the $HrpN_{Ep}$ although it requires further detailed analysis.

• 한국수산과학회지
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• 제42권6호
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• pp.604-608
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• 2009

This study was conducted to evaluate extruded pellet (EP) diet compared with a raw fish moist pellet (MP) diet for flounder, Paralichthys olivaceus on field feeding experiments in Jeju area. The experimental EP diet (juvenile, growing and adult) was prepared based on the former studies on nutrient requirements and feed ingredient of flounder. Fish were distributed randomly to each aquarium as a group of 102,300 fish (initial mean weight 97 g) in field experiment I and reared randomly to each aquarium as a group of 40,000 fish (initial mean weight 120 g) in field experiment II. In field feeding experiment I conducted in commercial flounder farm, survival, wt. gain (94-1,090 g), feed efficiency and condition factor of fish fed experimental EP were comparable to those of fish fed MP, but considerably higher protein efficiency ratio were observed in fish fed experimental EP. In field feeding experiment II, no significant difference was observed in final mean weight of fish fed the experimental EP (1,234 g) and MP (1,286 g), and any noticeable problem caused by feeding the experimental EP was not found during the whole period of feeding trial. Survival of fish fed the experimental EP was lower than that of MP, and there was no significant difference in feed efficiency between the fish fed experimental EP and MP. Therefore, these results strongly suggest that diet EP could be developed to replace MP diet for the marketable size (1.3 kg) of production for flounder without adverse effects on growth performance. In particular, abdominal dropsy and reduction of condition factor, which are frequently occurred in commercial EP feeding farms, were not observed in flounder fed experimental EP.

• 한국가금학회지
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• 제33권2호
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• pp.127-131
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• 2006

본 시험은 expanding 가공 기술이 산란계의 생산성, 계란 품질과 영양소 소화율에 대하여 알아보고자 실시하였다. 49주령 Hy-line Brown 270수를 공시하였고, 6주간 시험을 실시하였다. 1) MS(mash), 2) EC(expanded crumble) 및 3) EP( expanded pellet) 으로 3처리구로 구성하였으며, 처리 당 15반복, 반복당 6수씩 완전임의 배치하였다. 산란율은 EC와 EP 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타났다(p<0.05). 그러나 난중은 처리구간에 유의적인 차이는 없었다(p>0.05). 난각 강도는 EC와 EP 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타내었지만(p<0.05), 난각 두께는 처리 구간에 유의적인 차이를 나타내지 않았다(p>0.05). 난황색은 EC 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타났다(p<0.05). 난황 계수는 EC와 EP 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타났다(p<0.05). Haugh uint에 있어서 처리구간의 유의적인 차이는 없었으나(p>0.05), 변화량에 있어서 EP 처리구가 가장 높게 나타났다(p<0.05). 영양소 소화율에 있어서 건물, 칼슘, 인 소화율에 있어서 EP 처리구가 소화율을 개선시켰다(p<0.05). 본 연구 결과는 2차적인 사료 가공 기술이 산란계에 서 계란 품질과 영양소 소화율을 개선하였다.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3248-3252
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• 2012

Vibrio extracellular metalloprotease (vEP), secreted from Vibrio vulnificus, shows various proteolytic function such as prothrombin activation and fibrinolytic activities. Premature form of vEP has an N-terminal (nPP) and a C-terminal (C-ter100) region. The nPP and C-ter100 regions are autocleaved for the matured metalloprotease activity. It has been proposed that two regions play a key role in regulating enzymatic activity of vEP. Especially, C-ter100 has a regulatory function on proteolytic activity of vEP. C-ter100 domain has been cloned into the E. coli expression vectors, pET32a and pGEX 4T-1 with TEV protease cleavage site and purified using gel-filtration chromatography followed by affinity chromatography. To understand how C-ter100 modulates proteolytic activity of vEP, structural studies were performed by heteronuclar multi-dimensional NMR spectroscopy. Backbone $^1H$, $^{15}N$ and $^{13}C$ resonances were assigned by data from standard triple resonance and HCCH-TOCSY experiments. The secondary structures of vEP C-ter100 were determined by TALOS+ and CSI software based on hydrogen/deuterium exchange. NMR data show that C-ter100 of vEP forms a ${\beta}$-barrel structure consisting of eight ${\beta}$-strands.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1206-1212
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• 2009

Growth rates, photosystem II photosynthesis, and the levels of chlorophyll $\alpha$ and secondary metabolites of Chlorella ovalis were estimated to determine if they were enhanced by the addition of swine urine (BM) or cow compost water (EP) that had been fermented by soil bacteria to deep seawater (DSW) in an attempt to develop media that enabled batch mass culture at lower costs. Growth of C. ovalis in f/2, f/2-EDTA+BM60%, DSW+BM30%, and DSW+EP60% was enhanced and maintained in the log phase of growth for 16 days. The cell densities of C. ovalis in DSW+EP60% ($4.1{\times}10^6$ Cells/ml) were higher than those of f/2 ($2.9{\times}10^6$ Cells/ml), f/2-E+BM60% ($3.7{\times}10^6$ Cells/ml), and DSW+BM30% ($2.7{\times}10^6$ Cells/ml). The growth rate was also more favorable for C. ovalis cultured in DSW+EP60% ($0.15\;day^{-1}$) than that of C. ovalis cultured in the control medium (f/2) ($0.12\;day^{-1}$). Furthermore, the chlorophyll a concentration of C. ovalis cultured in DSW+EP60% (4.56 mg/l) was more than 2-fold greater than that of C. ovalis cultured in f/2 (2.35 mg/l). Moreover, the maximal quantum yields of photo system II at 470 nm (Fv/Fm) were significantly higher in organisms cultured at f/2-E+BM60% (0.53) and DSW+EP60% (0.52) than in the other treatment groups. Finally, Fourier transformation infrared (FT-IR) spectroscopy revealed that C. ovalis grown in DSW+EP60% had more typical peaks and various biochemical pool shifts than those grown in other types of media. Taken together, the results of this study indicate that the use of DSW+EP60% to culture C. ovalis can reduce maintenance expenses and promote higher yields.