• 한국수산과학회지
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• 제38권5호
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• pp.291-297
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• 2005

This study evaluated the quality of commercial extruded pellet (EP) diet of five companies (A, B, C, D and E) for olive flounder Paralichtys olivaceus by biochemical analyses, physical properties and growth performance. The proximate analyses of five EP diets showed $3.2-10.0\%$ of moisture, $49.3-55.5\%$ of crude protein, $4.6-14.7\%$ of crude lipid, $7.0-13.8\%$ of crude ash, $0.7-10.5\%$ of crude fiber, $10.0-27.3\%$ of itrogen free extract (NFE), 304.3-395.4kcal/100g of digestible energy (DE) and 6.1-7.1 of calorie/protein ratio (C/P). Peroxide value (POV) was highest in diet D (47.4 meq/kg) as compared to other diets which in the range of 4.0-11.7 meq/kg. Total amino acid contents were ranged from 46.54 to $55.46\%$ with the highest content in diet B and the lowest content in diet C. Essential amino acid of diet C was lowest $(7.43\%)$ as compared to other diets which in the range of $19.43-20.30\%$. Saturated fatty acid was higher in diet A $(37.65\%)$ followed by diet B $(36.32\%)$, diet E$(34.39\%)$, diet C$(30.95\%)$ and diet D$(30.10\%)$. EPA+DHA were highest in diet E$(30.78\%)$ and lowest in diet C$(15.48\%)$. The floating rate after 6 hours on the sea water was highest in diet C$(100\%)$ followed by diet B$(40\%)$ and A$(10\%)$. However, diets D and E were completely settled down after 1 and 2 hours, respectively. The range of relative expansion rate was $27.2-49.3\%$ for all diets and all reached the peak at 2-3 hours. The water absorption rate of diets C and D was lowest, and diet E was highest at 1 hour after deposition of sea water. Growth rate was higher in diet B$(22.3\%)$ and E$(21.3\%)$. Feed efficiency was higher in diet A$(109.7\%)$ and E$(105.3\%)$ and was significantly lowest in diet D$(80.7\%)$. The protein efficiency ratio was highest in diet E (2.72) and lowest in diet D (1.76). These results suggest that there is a necessity for improvement of nutrients balance and feed physical properties to fulfill the nutrient requirements and digestive characteristics of fishes in commercial EP diets.

• 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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.417-420
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• 2007

Micro parts are usually used of producing by micro-electro-mechanical systems(MEMS). In this paper, we present some fundamental results concerning on the MEMS, extrusion condition on the micro forming characteristics and new micro forward extrusion machine has been developed. In the first step, we manufactured micro dies in two kinds of sections. One is a circle section, another is a cross section. The process for fabricating micro dies combines a deep UV-lithography, anisotropic etching techniques and metal electroplating with bulk silicon based on Ni with a thickness of $50{\mu}m$. The outer diameter of Ni-micro dies is 3mm and the diameter of extrusion section is $270{\mu}m$ for a cross section, $500{\mu}m$ for a circle section. The low linear density polyethylene(LLEPD) in the shape of a pellet has been used of micro extrusion. The billet was placed in a container manufactured by electric discharge machining and extruded through the micro die by a piezoelectric actuator. The micro extrusion has succeeded in a forming such micro parts as micro bars, micro cross shafts.

• International Journal of Industrial Entomology and Biomaterials
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• 제28권1호
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• pp.1-4
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• 2014

The effect of an artificial diet on developmental rate, a life history parameter, was examined for the swallowtail butterfly Papilio xuthus. Artificial insect diets are an essential component of many insect rearing systems that produce insects for research purposes. Complex agar-gelled diets are generally prepared in large batches and used shortly after preparation because the degradation of perishable diet ingredients, such as vitamins and fatty acids, can adversely affect insect quality (Brewer 1984). However, the timing of diet preparation may be inconvenient, and large batches wasteful, if the unused excess is discarded. The percentage of pupation varied considerably, with no significant differences among diets, on which a maximum pupation percentage of 83% was observed. Pellet-type diets were investigated with the aim of developing a more easily prepared diet. The extrusion of the artificial diet under high temperature and pressure may induce desirable chemical and physical changes in the extruded product. The purpose of the present study was to develop an artificial diet for rearing P. xuthus.

• 한국분말재료학회지
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• 제23권4호
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• pp.276-281
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• 2016

Carbonyl iron (CI) is successfully incorporated as an additive into a polystyrene (PS) matrix via a highenergy ball milling method, under an n-hexane medium with volume fractions between 1% and 5% for electromagnetic interference shielding applications by the combination of magnetic CI and an insulating PS matrix. The morphology and the dispersion of CI are investigated by field emission scanning electron microscopy, which indicates a uniform distribution of CI in the PS matrix after 2 h of milling. The thermal behavior results indicate no significant degradation of the PS when there is a slight increase in the onset temperature with the addition of CI powder, when compared to the as-received PS pellet. After milling, there are no interactions between the CI and the PS matrix, as confirmed by Fourier transformed infrared spectroscopy. In this study, the milled CI-PS powder is extruded to make filaments, and can have potential applications in the 3-D printing industry.

• 한국양식학회지
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• 제20권1호
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• pp.51-55
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• 2007

이 연구는 실용 배합사료를 자체 제작한 기존의 배합사료, 상품사료 및 습사료를 장기간 걸쳐 사육한 넙치에 대해 육질을 평가하기 위해 수행하였다. 실험어는 13개월간 사육한 넙치 성어기(600 g 전후) 대상으로 수행하였으며, 실험사료는 시험사료(EP1 및 EP2) 2종, 상품사료(CEP) 및 습사료(MP)를 공급하였다. 전어체의 성분분석은 조단백질은 EP2가 EP1 및 CEP 사료구 보다 유의적으로 높게 나타났으며, 조지방은 EP2 및 MP 사료구가 CEP 사료구와 비교하여 유의적으로 높게 나타났다. 근육내 유리아미노산의 성분분석은 EP사료구간에서 MP 사료구보다 proline, glycine, alanine 함량이 높게 나타났으며, taurine에 있어서 EP1 사료구가 다른 사료구와 비교하여 높은 경향을 보였다. 핵산 관련물질 성분분석은 ATP 및 IMP의 양에서 배합사료에서 습사료보다 높은 값을 보였으며, 특히 EP2에서 다른 사료구와 비교하여 높은 값을 보였다. 관능검사는 향, 외관, 맛에 있어서 EP 사료구와 MP 사료구가 유의적인 차이를 보이지 않았다(P>0.05). 전반적인 기호도에 있어 EP2가 다른 사료구들보다 유의적으로 높게 나타났다. 물리적 성질의 경도 측정은 EP2는 EP1 및 CEP 사료구와 비교하여 높게 나타났으며, 탄력성과 응집성은 모든 사료구에서 차이를 보이지 않았다. 상기 결과를 토대로 그동안 배합사료를 넙치에 공급한 연구 결과를 고려하였을 때, 생사료를 공급한 넙치에 비해 품질이 결코 떨어지지 않으며, 오히려 배합사료를 공급한 양식산 넙치가 체계적인 관리 하에 앞으로 품질향상을 더 높일 수 있을 것이다.

• 산업식품공학
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• 제14권2호
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• pp.99-105
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• 2010

경제적 잠재성이 큰 삼 종자의 식품소재로서의 활용을 모색하고자 삼 종자의 일반성분을 측정하였고 삼 종자 첨가 압출성형펠릿의 호화양상을 분석하기 위하여 페이스트 점도를 측정하였다. 또한 삼 종자 후레이크의 체적밀도, 색도, 압착강도, 수분용해지수와 수분흡착지수, 조직감 유지 시간(bowl life) 등의 품질특성을 조사하였다. 압출성형 공정조건은 배럴온도 90, 100, 110$^{\circ}C$, 수분함량 35%이었다. 삼 종자의 수분, 조단백질, 조지방, 조회분함량은 각각 5.67${\pm}$0.02, 25.93${\pm}$0.16, 28.21${\pm}$0.56, 7.70${\pm}$0.08%이었다. 압출성형 펠릿의 페이스트 점도 측정결과 삼 종자 펠릿의 제조에 적합한 압출성형 배럴온도는 100-110$^{\circ}C$인 것으로 판단되었다. 삼 종자 후레이크의 체적밀도는 0.24-0.43 g/mL 범위로 배럴온도가 증가함에 따라 감소하는 경향을 나타내었다. 명도와 압착강도는 삼 종자 첨가량이 증가함에 따라 크게 감소하는 경향을 나타내었다. 배럴온도가 90$^{\circ}C$에서 110$^{\circ}C$로 증가함에 따라 수분용해지수는 감소하는 경향을 나타내었고 수분흡착지수는 증가하는 경향을 나타내었다. 조직감 유지시간은 5.8-15.5분 범위로 삼 종자 첨가량의 증가에 따라 감소하였다. 관능검사 결과 전체적인 기호도는 삼 종자 첨가량 20%일 때 가장 높은 값을 나타내었다.

• 한국양식학회지
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• 제21권4호
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• pp.299-303
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• 2008

외해가두리 시험양식 대상종으로 선정된 돌돔에 대하여 저수온기($15^{\circ}C$)에 1년어(62.7 g)와 2년어(344.7 g)에 대한 적정 배합사료 공급량을 조사한 결과, 돌돔 1년어(62.7g)의 적정배합사료 공급율은 어체중의 1.61% (만복의 90%)일 때 증체율 및 사료효율에서 높은 값을 나타내었다. $15^{\circ}C$에서 돌돔 2년어(344.7 g)에 대하여 적정 공급율을 조사한 결과는 어제중의 0.28% (만복의 80%)일 때 가장 높은 성장을 하였으나 시험구간에 오차가 컸고, 전반적으로 낮은 값을 나타내었다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.272-277
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• 2012

Compensatory growth of grower olive flounder (Paralichthys olivaceus) was determined at suboptimal temperature ($13.0{\pm}1.9^{\circ}C$). Fifteen fish averaging 201.1 g per tank were distributed into 18 of 300 L flow-through tanks. Six treatments were prepared in triplicate: fish were hand-fed with an extruded pellet to apparent satiation once a day for 16 weeks (16 WF); and the other five groups of fish were hand-fed for 15, 14, 13, 12 and 10 weeks after 1-, 2-, 3-, 4- and 6-week feed deprivation, referred to as 15 WF, 14 WF, 13 WF, 12 WF and 10 WF, respectively. A linear relationship between body weight of fish and feed deprivation was observed: Y (Body weight of fish) = -1.81X (Weeks of feed deprivation)+201.07, $R^2$ = 0.83. Weight gain of grower olive flounder in 15 WF, 14 WF, 13 WF and 12 WF treatments was comparable to that of fish in 16 WF treatment, but lower than that of fish in 10 WF treatment. Specific growth rate of fish in 15 WF treatment was higher than that of fish in 16 WF, 14 WF and 10 WF treatments. Feed consumption of fish was not affected by feeding regime. Feed and protein efficiency ratios of fish in 15 WF treatment were higher than those of fish in 13 WF, 12 WF and 10 WF treatments. Grower olive flounder could achieve full compensatory growth when fish were daily fed for 12 weeks after 4-week feed deprivation at suboptimal temperature.

• 수산해양교육연구
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• 제26권4호
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• pp.789-796
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• 2014

This study was conducted to investigate the effects of feeding rate on growth performance, blood components and histology of growing olive flounder. The experiment was carried out to determine the optimum feeding rate of the fish (initial fish mean weight of $97{\pm}3.0$ g) at the optimum water temperature. Two replicated groups of fish were fed commercial diet at the feeding rates of 0, 1.0, 1.65 and 2.3% body weight (BW)/day and satiation. Feeding trial was conducted under a flow-through system with ten 1.2 metric ton aquaria receiving filtered seawater at $21{\pm}2^{\circ}C$ for three weeks. Weight gain and specific growth rate (SGR) for fish fed to satiation were significantly higher than those for the unfed fish and for fish fed at 1.0 and 1.65% BW/day. There were no significant differences in values of such parameters between fish fed at 1.65% and those fed at 2.3% BW/day and between fish fed at 2.3% and those fed to satiation. Weight gain and SGR for the unfed fish were significantly lower than those for fish in the other treatments. All the tissues (hepatopancreas, kidney and anterior intestine) were in good condition in fish fed the experimental diet at different feeding rates. This result indicates that the optimum feeding rates of olive flounder (97-160 g) was approximately 2.52% BW/day at the optimum water temperature.