• Journal of Advanced Marine Engineering and Technology
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• 제37권1호
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• pp.53-58
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• 2013

비에스테르화 대두유의 활용 가능성을 평가하기 위해 현재 대부분의 디젤 자동차에 채택되어 있는 전자 제어 분사식 과급디젤기관에 경유, 에스테르화 바이오 디젤유 5% 및 비에스테르화 대두유 5% 혼합유를 사용하여 성능 실험을 실시하였다. 그 결과, 에스테르화 바이오 디젤유 5%와 비에스테르화 대두유 5%의 연소성능이 대부분 비슷하지만 NOx는 비에스테르화한 것이 더 적게 배출되었고 이는 Fuel NO에 의한 것을 밝혔다.

• 동력기계공학회지
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• 제17권6호
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• pp.11-17
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• 2013

Esterified bio-diesel oil is normally used as blend oil of 3% that and 97% diesel fuel in Korea. Since specifics of it is similar to that of diesel fuel, availability of non-esterified bio-diesel oil that has a lower expenses of manufacturing is worthy of attention. However, bio-diesel oil has a demerit which it emits typically more NOx emission than diesel fuel. In this study, characteristic tests using blending oil with 95% gas oil and 5% bio-diesel oil were achieved at lower common rail pressure in order to improve this demerit. It was noticed that non-esterified bio-diesel oil has more similar characteristics to diesel fuel than esterified bio-diesel oil and it emits more NO emission by fuel NO mechanism.

• 수산해양기술연구
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• 제49권1호
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• pp.51-57
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• 2013

A demand for bio-diesel oil increases as one of solution for exhaustion of fossil fuel and reduction of $CO_2$ emission, and research on bio-diesel is being carried out. Bio-diesel oil is mainly esterified from vegetable oil with methanol in order to use for fuel on diesel engine and has demerit that costs are increased as compared with directly using like non-esterified one. Bio-diesel oil within 3% mixed with gas oil is used at present, proportion of bio-diesel oil will be increase by 5% in future. We judged that wasted soybean oil non-esterified could be used on diesel engine with an electronic fuel injection according to previous researches with a mechanical fuel injection. A performance test using only gas oil, gas oil with esterified bio-diesel oil 5% and wasted soybean oil non-esterified 5% on diesel engine with the electronic fuel injection were carried out. It is noticed that gas oil with wasted soybean oil non-esterified 5% has more similar characteristics to gas oil than gas oil with esterified bio-diesel oil 5%.

• Journal of Advanced Marine Engineering and Technology
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• 제39권1호
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• pp.8-12
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• 2015

비에스테르화 바이오 디젤유는 에스테르화 공정을 거치지 않기 때문에 공정에 드는 비용이 절감되며 경유에 5%로 혼합하여 전자제어 분사식 디젤엔진에 사용할 경우 에스테르화 바이오 디젤유보다 경유에 더 유사한 성능을 나타내었다. 이러한 연구를 바탕으로 경유에 5% 혼합된 비에스테르화 바이오 디젤유를 전자제어 분사식 디젤엔진에 적용하기 위해서는 성능 최적화가 필요하다. 본 연구에서는 비에스테르화 바이오 디젤유의 성능 최적화를 위한 기초 실험으로 연료소비율, 질소산화물 및 도시평균유효압력을 반응치로 정하고 제어 가능한 6가지 인자에 대해서 그 영향력을 평가하고자 부분요인배치법을 이용하여 25%와 50%의 부분 부하에서 실험을 수행하였다. 그 결과 6가지 인자 중 분사시기 및 커먼레일압력이 가장 큰 영향을 미쳤고 각 부하에서 영향의 크기는 다르게 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.239-248
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• 1994

To study the relationship between certain hormones and metabolites and between hormones and milk yield during different stage of lactation, six lactating Karan Swiss cows and six Murrah buffaloes were maintained. Growth hormone, insulin, $T_3$, $T_4$, glucose, BHBA, NEFA and milk yield were studied. Highly negative relationship of growth hormone with insulin and triiodothyronine in cows and marginally negative in buffaloes suggest that insulin and triiodothyronine aid in the process of partitioning of nutrients towards milk production through reducing the demands of nutrients by peripheral tissue. The significant and negative correlation of growth hormone with dry matter intake in both the species suggest that the availability of nutrients from the digestive tract play a role in the regulation of growth hormone secretion. Positive relationship of growth hormone with non esterified fatty acids in both the species suggest that high growth hormone levels may result in fat mobilization and thereby increase the availability of energy precursors for milk synthesis. Insulin was negatively correlated with milk yield and lactose content and positively with milk fat and protein but the degree of relationship varied. In both the species the relationship between triiodothyronine and milk yield was negative and between thyroxine and milk yield was positive. However, it was significant only in cows and not in buffaloes. Thyroxine was positively correlated with beta-hydroxybutyrate and non-esterified fatty acids with milk yield in both the species.

• 동력기계공학회지
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• 제20권2호
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• pp.51-57
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• 2016

Non-esterified biodiesel fuel is cheaper than esterified that because of a simple manufacturing process that only consists of filtering. Applicability of this on diesel engine with electronic control system was accomplished, then optimization adopting a fractional factorial design and response surface methodology was carried out at 25% and 50% of engine load in this study. Pressure of common rail and injection timing mainly effected on responses as specific fuel oil consumption and nitrogen oxides regardless of engine load. Estimations were 310.3 g/kWh of specific fuel oil consumption and 237 ppm of nitrogen oxides at 25% load, and 233.2 g/kWh of specific fuel oil consumption and 730 ppm of nitrogen oxides at 50% load. Tests to verify these estimations were accomplished and as the results, specific fuel oil consumption was 300.4 g/kWh and NOx was 277 ppm at 25% load and 236.8 g/kWh and 573 ppm at 50% load.

• 한국응용과학기술학회지
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• 제38권5호
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• pp.1282-1291
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• 2021

본 연구는 NaF 경구 투여가 Sprague Dawley계 수컷 흰쥐의 혈청 중 non-esterified fatty acid (NEFA), blood urea nitrogen (BUN), creatinine, uric acid 및 전해질 농도에 미치는 영향을 조사하기 위하여, 기본식이를 급여한 대조군인 BG군과 기본식이에 NaF 경구 투여군(NF3~50군) 9그룹의 식이군으로 나누어 5주간 실험사육을 행하였다. 흰쥐의 NEFA와 BUN, creatinine, uric acid 농도는 NaF 농도에 비례적으로 증가하였으며, 고농도의 NaF 투여군에서 대조군보다 유의적인 차이로 높게 관찰되었다(𝛼=0.05). 한편, 전해질 농도 중 total calcium (T-Ca)과 인(Pi) 농도는 대조군보다 NaF 투여군에서 낮게 동정되었으며, NaF 20 mg 이상 경구 투여한 군에서 유의적인 차이를 보였다(𝛼=0.05). 흰쥐의 NaF 경구 투여 처리는 농도가 증가함에 따라 NEFA 및 BUN, creatinine, uric acid의 농도가 상승하였으며, 전해질 농도는 저하되는 것으로 나타나 신장 기능 장애 등 바람직하지 않은 영향을 주는 것으로 확인되었다.

• Journal of Nutrition and Health
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• 제28권5호
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• pp.375-386
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• 1995

This study was designed to investigate the changes in energy substrates, glucose and non-esterified fatty acid(NEFA), and fatty acid compositions in serum, following physiolgical stress in rats fed diets containing various fatty acids. Forty two Sprague-Dawley strain male rats, weighing 108$\pm$2.1g, were fed 3 different experimental diets for 4 weeks. The diets were composed of 105 fat(w/w) of either corn oil(CO;18:2 n6:57%), plant perilla oil(PO;18:3 n3:59%), or tuna fish oil(FO;20:5 n3:17%%, 22:6 n3:19%). After 4 weeks of feeding, each group wa subdiveided into (a) control, (b) 2 min swim in ice-cold water. Animals wer decapitated 20min after commencing the swim; trunk blood, brain, liver and epididymal fat pad were obtained. The levels of serum corticosterone, glucose, NEFA, triglyceride, fatty acid compositions, brain serotonin and 5-hydroxyindoleacetic acid were determined. Basal levels of corticosterone na NEFA of serum were significantly lower in fish oil fed animals than those of any other oil fed animals. Compared to either perilla oil-fed or corn oil-fed rats, cold swim stress in fish oil fed rats produced significantly smaller NEFA and larger corticosterone responses. However, there was no significant difference in basal levels of serum glucose. Stress increased serum glucose levels slightly, and the amount of increment was larger in fish oil rats than those of any other oil fed rats than those of any other oil fed rats, although all the values were normal level. Dietary fats and stress did not affect serotonin metabolism. In additions, the composition of fatty acids in serum was significantly affected by the dietary compostion of fatty acids and stress. Stress induced decreases in monounsaturated fatty acid and non-polyunsaturated fatty acid concentration in either perilla oil fed or fish group, but did not in corn oil fed group. Stress resulted in changes in fatty acid metabolism similar to that associated with essential fatty acid(EFA) dificiency, when feeding animals n-3 fatty acids in diet. In conclusion, feeding fish oil was more effective to decrease NEFA in serum than feeding perilla oil or corn oil and improved lipid metabolism, when the rats were maintained in normal or exposed to stressful environment. However, the fact that feeding diet containing n-3 fatty acids decreased EFA status under stress suggests that the requirement of n-6 PUFA should be increased in these groups.

• 한국임상수의학회지
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• 제34권3호
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• pp.222-224
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• 2017

A retrospective study was designed to determine whether there were any differences in prepartal blood biochemical parameters between cows developed subclinical ketosis (SCK) and non-SCK cows. Data on blood biochemistry from 33 Holstein parturient cows (15 SCK and 18 non-SCK cows) in one farm for one year, were compared. Plasma beta-hydroxybutyrate, non-esterified fatty acid and glucose concentrations were utilized in the diagnosis of SCK and showed significant differences between SCK and non-SCK cows after calving. Before calving, however, only plasma total cholesterol concentration in SCK cows was significantly lower than that in non-SCK cows. Consequently, it seems that lower plasma total cholesterol concentration before calving is related to the occurrence of SCK immediately after calving.

• 한국응용과학기술학회지
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• 제35권1호
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• pp.186-193
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• 2018

본 연구는 식이조성에 동결 건조한 krill (Euphausia superba) meal을 첨가 하였을 때 Sprague Dawley계 수컷 흰쥐의 유리지방산(non-esterified fatty acid, NEFA), blood urea nitrogen(BUN), creatinine, uric acid 및 전해질에 미치는 영향에 대하여 조사를 하였다. 식이조성은 기본식이를 급여한 대조군인 GC군(krill meal 미함유)을 비롯하여 기본식이에 10.0%, 20.0%, 30.0%의 krill meal 급여군을 각각 G10군, G20군, G30군으로 구분하였다. 5주간 실험 사육한 결과, 흰쥐의 NEFA와 BUN 농도는 krill meal 급여군(G10군, G20군, G30군)에서 대조군(GC 군)보다 유의적으로 감소된 결과를 보였고, creatinine과 uric acid 농도는 G10군에서는 GC군과 유의적 차이가 없었으나, G20군과 G30군에서 유의적으로 감소하였다(p<0.05). 전해질 농도에서 total calcium (T-Ca)은 G20군과 G30군에서 유의적으로 증가하였으며, 인(Pi) 농도는 각 군간에 유의적 차이가 없는 것으로 관찰되었다(p<0.05).