• 설비공학논문집
• /
• 제8권3호
• /
• pp.307-316
• /
• 1996

The objective of present study is to obtain information on the stenosis effects in the branch tubes for industrial piping system and atherogenesis processing in human arteries. Numerical solutions for flows of Newtonian and non-Newtonian fluids in the branch tubes are obtained by the finite volume method. Centerline velocity and pressure along the bifurcated tubes for water, blood and aqueous Separan AP-273 solution are computed and the numerical results of blood and the Separan solution are compared with those of water. Flow phenomena in the stenosed branch tubes are discussed extensively and predicted effectively. The effects of stenosis on the pressure loss coefficients are determined.

• Journal of Magnetics
• /
• 제22권2호
• /
• pp.344-351
• /
• 2017

Wireless magnet pumps are used in medical applications and are particularly useful as artificial heart ventricular assist devices (VADs). To investigate wireless operation of magnetic pumps, we fabricated three types of magnetic impellers using bonded magnets by blending magnetic powders of SmFeN, NdFeB, and Sr-ferrite. We investigated the magnetic properties of the fabricated magnetic impellers, which are driven by the application of magnetic coupling with an external driving magnet or external coil system, without a driving motor, shaft, or mechanical bearings. The use of wireless magnetic pumps is therefore not complicated by critical issues of size, heat, and vibration, which are very important issues for blood pumps. The magnetic properties of the impellers, such as their rotational speed, driving torque and hydrodynamic performance, determine their wireless driving ranges. We conducted performance evaluations of the impeller's magnetic wireless manipulation, heat, and vibration. In addition, we carried out an animal test to confirm the suitability of the wireless magnetic pumps for use as biventricular assist devices (BiVADs).

• 농업과학연구
• /
• 제44권4호
• /
• pp.574-585
• /
• 2017

This study was conducted to investigate effects of a potato byproduct on growth performance, blood metabolites, and carcass characteristics of Hanwoo steers. The palm oil coated potato byproduct was supplemented to the diet of Hanwoo steers to estimate the effect on growth performance, blood metabolites, and carcass characteristics during the late fattening period. Thirteen steers with initial body weight of control ($676.8{\pm}31.7kg$), treatment 1 ($671.8{\pm}46.2kg$) and treatment 2 ($672.8{\pm}31.1kg$) were used for 60 days, respectively. Average daily gain of steers in treatment 2 and control was greater than that in treastment 1 (p > 0.05). All steers in treatment 2 had a grade quality grading system than B in meat quantity and had a meat quality higher than the $1^{st}$ grade. According to the physicochemical analysis of longissimus muscle, treatment 2 had high brightness resulting from high meat quality (p > 0.05), and a decrease in redness and yellowness is seen as a dilution effect due to muscle hypertrophy (p > 0.05). The fatty acid composition showed low levels of linoleic acid (p = 0.039) and arachidonic acid (p = 0.008) in treatment 2. This resulted in lower polyunsaturated fatty acid (PUFA) levels (p = 0.034). On the other hand, high levels of oleic acid resulted in high levels of MUFA (p > 0.05). These results indicate that potato byproduct had similar effects with ${\beta}_2-adrenergic$ agonist (${\beta}_2-AA$). And there was no negative effect on the intramuscular fat. In conclusion, palm oil coated potato byproduct could be potentially used as an alternative growth enhancer.

• Journal of Animal Science and Technology
• /
• 제58권10호
• /
• pp.37.1-37.10
• /
• 2016

Background: Providing of insufficient nutrients limits the potential growth of pig, while feeding of excessive nutrients increases the economic loss and causes environment pollution. For these reasons, phase feeding had been introduced in swine farm for improving animal production. This experiment was conducted to evaluate the effects of dietary energy levels and phase feeding by protein levels on growth performance, blood profiles and carcass characteristics in growing-finishing pigs. Methods: A total of 128 growing pigs ([Yorkshire ${\times}$ Landrace] ${\times}$ Duroc), averaging $26.62{\pm}3.07kg$ body weight, were assigned in a $2{\times}4$ factorial arrangement with 4 pigs per pen. The first factor was two dietary energy level (3,265 kcal of ME/kg or 3,365 kcal of ME/kg), and the second factor was four different levels of dietary protein by phase feeding (1growing(G)-2finishing(F) phases, 2G-2F phases, 2G-3F phases and 2G-3F phases with low CP requirement). Results: In feeding trial, there was no significant difference in growth performance. The BUN concentration was decreased as dietary protein level decreased in 6 week and blood creatinine was increased in 13 week when pigs were fed diets with different dietary energy level. The digestibility of crude fat was improved as dietary energy levels increased and excretion of urinary nitrogen was reduced when low protein diet was provided. Chemical compositions of longissimus muscle were not affected by dietary treatments. In backfat thickness ($P_2$) at 13 week, pigs fed high energy diet had thicker backfat thickness (P = 0.06) and pigs fed low protein diet showed the trend of backfat thinness reduction (P = 0.09). In addition, water holding capacity was decreased (P = 0.01) and cooking loss was increased (P = 0.07) as dietary protein level reduced. When pigs were fed high energy diet with low subdivision of phase feeding, days to 120 kg market weight was reached earlier compared to other treatments. Conclusion: Feeding the low energy diet and subdivision of growing-finishing phase by dietary protein levels had no significant effect on growth performance and carcass characteristics. Also, phase feeding with low energy and low protein diet had no negative effects on growth performance, carcass characteristics but economical profits was improved.

• 정신신체의학
• /
• 제9권2호
• /
• pp.194-202
• /
• 2001

연구목적: 심혈관질환이 주요한 사인을 차지하면서 혈청 지질에 대한 관심이 점점 높아지는 추세이다. 혈청 지질 농도와 심리적 특성 사이의 관련성에 대한 많은 보고가 있었지만, 일관된 결론은 내리지 못한 상태이다. 본 연구에서는 청소년을 대상으로 그 동안의 연구를 통해서 지적되어온 충동성, 공격성, 우울성과 혈청 콜레스테롤 및 중성지방 농도 사이의 관련성을 조사하였다. 방법: 고등학교 1 학년생을 대상으로 2000년 5월에서 6월 사이에 실시하였으며, 이 가운데 혈청 지질 농도에 제외시키는 배제 기준을 통과한 407명을 연구에 포함시켜 조사하였다. 위하여 Barratt 충동성 척도(Barratt Impulsiveness Scale, BIS)를 사용하였으며, 공격성 검사는 Buss-Durkee 공격성 척도 (Buss-Durkee Hostility Inventory, BDHD를 사용하였고, 우울성 검사는 Beck 우울 척도(Beck Depression Inventory, BDI)를 사용하였다. 혈액 검사를 통하여 혈청 지질 농도 및 전혈 계산, 전해질 검사 간기능 검사, 혈당 검사 등을 실시하였고, 소변 건사도 병행 실시하였다. 결과: 1) 저콜레스테롤 집단은 고콜레스테롤 집단에 비하여 여성에서 BIS 총점이 의미 있게 높았으며, BIS 하위척도 분석에서는 운동 충동성이 유의미하게 높은 것으로 나타났다. 2) 고중성지방 집단은 저중성지방 집단에 비하여 남녀 모두에게 BDI 점수가 있게 높았으며, 또한 남성에서는 BIS 총점도 유의미하게 높았고, BIS 하위척도 분석에서는 역시 운동 충동성이 의미 있게 높았다. 결론: 이 연구의 결과는 혈청 지질 농도가 심리적 특성과 관련이 있으며, 특히 충동성 및 우울성이 밀접하게 관련된다는 것을 보여준다.

• Journal of Biosystems Engineering
• /
• 제27권1호
• /
• pp.59-66
• /
• 2002

The objectives of the study were to analyze the acoustic characteristics related to the internal quality factors of watermelon(Citrulus Vulgaris Schrad). Among the various internal quality factors, only four factors such as ripeness, inside cavity, yellow belt and blood flesh were considered in this study. Relationships between the internal quality factors, the day after fruit set and the day after harvest were also investigated. Test apparatus was the same as the apparatus described in the previous study(Choi et at., 2000). The selected sample was divided into four groups; 69 samples used for ripeness tests 56 samples for ripeness test along the day after fruit set and for yellow belt detection, 60 samples for ripeness along the day after harvest 44 samples fur blood flesh detection. It was shown that the first peak frequencies shifted to the lower range and the energy ratios of the bandwidths between 0∼550 Hz to the bandwidths between 850∼2500 Hz increased as the day after fruit set elapsed. Since the acoustic responses of the watermelon such as frequency and magnitude began to change from 10 days after harvest, the storage period of watermelon in a normal temperature condition seemed to be approximately 10 days after harvest. The ratios of the first peak amplitude to the maximum peak amplitude fur the sound watermelon showed the higher value than that fur watermelon with cavity inside, and the separation between the sound and cavity inside could be accomplished by the ratio value of 0.25. The energy ratios (0∼550 Hz/850∼2,500 Hz) for the watermelon with cavity inside showed the higher value than 2.3. The frequency characteristics of the yellow belt watermelon appeared mostly in the range of 600∼900 Hz frequencies. The yellow belt watermelon showing the energy spectral density function at this frequency range to be over 70 seemed to be not a marketable commodity, The energy ratios(0∼550 Hz/850∼2,500 Hz) for the blood flesh watermelon showed the higher value than 3.5.

• 농업생명과학연구
• /
• 제50권5호
• /
• pp.153-162
• /
• 2016

본 연구는 국내 실정에 맞는 적정 TDN/CP 비율을 결정하기 위하여 4.6:1(T1)과 4.3:1(T2)의 비율로 생후 13개월령 육성우에게 급여하여 영양소 섭취량, 소화율, 반추 위액 특성 및 혈액조성에 대하여 조사하였다. 건물 섭취량은 9.0kg/day로 동일하였으며, 조단백질 섭취량은 T1이 1.34kg/day, T2가 1.45kg/day로 T2가 조금 높았으나 유의적인 차이는 없었다. 섬유소 섭취량과 소화율은 T1이 조금 높은 경향을 보였으나 유의적인 차이는 없었다. 사료 섭취 후 4시간째 위액의 pH, ammonia-N, VFA 농도를 비교한 결과 처리구간 유의적인 차이를 나타내지 않았다. 전반적인 VFA 수치는 TDN/CP 비율에 따라 큰 영향이 없었으나 T1 처리구에서 iso-butyrate, iso-valerate 및 A/P ratio가 유의적으로 높은 결과를 보였다(p<0.05). 혈액 특성에는 처리구간 유의적인 차이를 나타내지 않았다. TDN/CP 비율이 4.3:1과 4.6:1 수준은 반추위 특성에 큰 영향을 미치지 않았지만, 소화율과 비교하였을 때 생후 13개월령 육성우 시기에는 섬유소 섭취량과 소화율이 증가되는 4.6:1 수준이 보다 적합할 것으로 판단된다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2002년도 학술대회지
• /
• pp.699-702
• /
• 2002

Shunt valves implanted in the subcutaneous tissue of brain to treat patient with hydrocephalus were numerically simulated to investigate influence of pressure pulsation on their flow control characteristics. Shunt valves are subjected to pressure variation since ventricles enclosing the brain are under pressure pulsation rather than uniform pressure due to blood pressure variation. We modeled flow orifice through shunt valve and imposed pulsating pressure and valve diaphragm movement to compute flow through the valve. The results of our study indicated that flow rate increased by $40{\%}$ by introducing pressure pulsation and diaphragm movement on the shunt valve. Our results demonstrate the pressure-flow control characteristics of shunt valves unplanted above human brain may be quite different from the characteristics obtained by syringe pump test with uniform pressure and no diaphragm movement.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권11호
• /
• pp.1646-1654
• /
• 2005

The present study was carried out to develop cholesterol-reduced and gamma linolenic acid (GLA)-added butter and to examine the changes in chemical and sensory properties, and cholesterol lowering effect of GLA addition. The cholesterol removal rate reached 93.2% by $\beta$-cyclodextrin in butter before GLA addition. The thiobarbituric acid value of cholesterol-reduced and GLA-added butter increased slowly up to 4 week and plauteaued thereafter. TBA value was significantly increased with 2% GLA addition, compared with no GLA addition. The production of short-chain free fatty acids (FFA) increased with storage in all treatments. From 4 weeks storage, the amount of short-chain FFA in 2% GLA-added group was significantly higher than those in other groups. Among sensory characteristics, color, greasiness and overall acceptability were mostly affected by GLA addition, however, the rancidity value of 2% GLA addition was significantly different from those of control and GLA-unadded and cholesterol-reduced butter at 0, 6 and 8 week storage. Among groups, no difference was found in texture in all storage periods. The smallest increase of total blood cholesterol in rats was found in the group fed 2% GLA-added and cholesterol-reduced butter for 8 week, compared with that in controls. The present results showed the possibility of cholesterol-reduced and GLA-added butter development without much difference in chemical, rheological and sensory properties, and indicated a slow increase effect on blood total cholesterol in rats.

• 한국산업보건학회지
• /
• 제19권1호
• /
• pp.30-38
• /
• 2009

The objective of this study was to evaluate the effects of occupational exposure to styrene on the components of metabolic syndrome. We surveyed 263 employees, among whom 117workers we ere chronically exposed to styrene in glass-reinforced plastic boat manufacturing factories and 146 controls had never been occupationally exposed to styrene as will as hazardous chemicals. The general and job characteristics such as age, smoking and drinking habit, working hours and duration were not significant different except sleeping hours(p<0.05). Among the components of metabolic syndrome, the systolic blood pressure, total cholesterol, HDL-cholesterol and fasting glucose were significantly higher in exposed workers. On multiple logistic regression analysis for the components of metabolic syndrome, waist circumference was insulin (OR=1.129), blood pressure was MA(OR=14.724), fasting glucose(OR=1.191) and metabolic syndrome(OR=1.110) were significantly associated with insulin. The mean concentration of airborne styrene was $ 38.1{\pm}40.1$ ppm, blood concentrations of glucose and insulin and levels of HOMA-IR in over 50 ppm exposed group were higher than in blow 50 ppm exposed group. These results suggested that the exposure of styrene affects blood pressure, fasting glucose and insulin levels and that dysfunction and/or declination in glucose and insulin metabolism might induced ultimately insulin resistance and metabolic syndrome.