• Title, Summary, Keyword: Energy density

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Effect of reduced energy density of close-up diets on metabolites, lipolysis and gluconeogenesis in Holstein cows

  • Huang, Wenming;Wang, Libin;Li, Shengli;Cao, Zhijun
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.5
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    • pp.648-656
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    • 2019
  • Objective: An experiment was conducted to determine the effect of reduced energy density of close-up diets on metabolites, lipolysis and gluconeogenesis in cows during the transition period. Methods: Thirty-nine Holstein dry cows were blocked and assigned randomly to three groups, fed a high energy density diet (HD, 1.62 Mcal of net energy for lactation $[NE_L]/kg$ dry matter [DM]), a medium energy density diet (MD, $1.47Mcal\;NE_L/kg\;DM$), or a low energy density diet (LD, $1.30Mcal\;NE_L/kg\;DM$) prepartum; they were fed the same lactation diet to 28 days in milk (DIM). All the cows were housed in a free-stall barn and fed ad libitum. Results: The reduced energy density diets decreased the blood insulin concentration and increased nonesterified fatty acids (NEFA) concentration in the prepartum period (p<0.05). They also increased the concentrations of glucose, insulin and glucagon, and decreased the concentrations of NEFA and ${\beta}-hydroxybutyrate$ during the first 2 weeks of lactation (p<0.05). The plasma urea nitrogen concentration of both prepartum and postpartum was not affected by dietary energy density (p>0.05). The dietary energy density had no effect on mRNA abundance of insulin receptors, leptin and peroxisome proliferator-activated $receptor-{\gamma}$ in adipose tissue, and phosphoenolpyruvate carboxykinase, carnitine palmitoyltransferase-1 and peroxisome proliferator-activated $receptor-{\alpha}$ in liver during the transition period (p>0.05). The HD cows had higher mRNA abundance of hormone-sensitive lipase at 3 DIM compared with the MD cows and LD cows (p = 0.001). The mRNA abundance of hepatic pyruvate carboxy-kinase at 3 DIM tended to be increased by the reduced energy density of the close-up diets (p = 0.08). Conclusion: The reduced energy density diet prepartum was effective in controlling adipose tissue mobilization and improving the capacity of hepatic gluconeogenesis postpartum.

Effects of supplemental glycerol polyethylene glycol ricinoleate in different energy density diets on the growth performance, blood profiles, nutrient utilization, and excreta gas emission of broilers: focus on dietary glycerol polyethylene glycol ricinoleate in broilers

  • Yin, Jia;Yun, Hyeok Min;Kim, In Ho
    • Korean Journal of Agricultural Science
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    • v.45 no.2
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    • pp.219-228
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    • 2018
  • This study evaluated the effects of glycerol polyethylene glycol ricinoleate (GPGR) supplementation in different energy density diets on the growth performance, blood profiles, excreta gas emission, and total tract apparent retention (TTAR) of nutrients in broilers. A total of 544 one-day-old male Ross broilers were used in a 35-day trial. The broilers were allocated into one of four treatment groups in a $2{\times}2$ factorial arrangement with two levels of energy densities (a normal energy or decreased energy density) and GPGR (0 and 0.035%). From day 18 to 35, the GPGR supplemented and normal energy density diet groups showed a significantly improved (p < 0.05) body weight gain (BWG). Meanwhile, the GPGR supplemented diet group had a significantly reduced (p < 0.05) feed conversion ratio (FCR) compared to that of the non-supplemented diet group. From day 0 to 35, the GPGR supplemented diet and the normal energy density diet groups had a significantly increased (p < 0.01) BWG and a reduced (p < 0.01) FCR. Moreover, GPGR supplementation tended to increase (p < 0.1) the TTAR of the dry matter (DM) compared with the non-supplemented diets. Likewise, the normal energy density diets had a significantly improved TTAR for the gross energy (GE) (p < 0.05) than that of the decreased energy density diets. No interactive effects were observed between the energy density and GPGR supplemented diets. In conclusion, both dietary GPGR supplementation and normal energy density diets had beneficial effects on the growth performance of broiler chickens without any adverse effects on blood profiles and excreta gas emission.

Effects of High Energy Density Diet on Pork Quality (고에너지 수준의 사료급여가 돈육 품질에 미치는 영향)

  • Lee Jae-Ryong;Hah Seung-Ho;Do Chang-Hee;Lee JeoungDong;Hah Young-Joo;Jung Jae-Doo;Lee Jin-Woo;Lee Jeong-Ill;Lee Jin-Hee
    • Food Science of Animal Resources
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    • v.24 no.3
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    • pp.209-215
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    • 2004
  • In a trial involving 120 pigs, the growth performance of finishing pigs and proximate composition, physicochemical properites and fatty acid composition of loin muscle were investigated by feeding the high-energy density diet and low-energy density diet. The treatments included feeding 1) the low-energy density diet (3,290 cal/kg DE, 14.50% CP, 0.70% lysine and 0.78% Ca) for 38 days and 2) the hight-energy density diet (3,350 cal/kg ME, 15.0% CP, 0.70% lysine and 0.78% Ca) for 27 days. The average daily gains were significantly higher for pigs fed the high-energy density diet than those fed the low-energy density diet, but average daily feed intake and feed conversion rate were significantly lower than those fed the low-energy density diet (p<0.05). The cooking loss and yellowness of pork were significantly (p<0.05) lower for pigs fed the low-energy density diet than those fed the high-energy density diet. There were no significant differences in carcass characteristics, proximate composition and fatty acid composition of pork. In conclusion, the results of the experiment suggested that the high-energy density diet for pigs tended to improve the growth performance, but the cooking loss and yellowness of pork were higher for pigs fed the high-energy density diet than those fed the low-energy density diet.

Comparison of Wind Energy Density Distribution Using Meteorological Data and the Weibull Parameters (기상데이터와 웨이블 파라메타를 이용한 풍력에너지밀도분포 비교)

  • Hwang, Jee-Wook;You, Ki-Pyo;Kim, Han-Young
    • Journal of the Korean Solar Energy Society
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    • v.30 no.2
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    • pp.54-64
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    • 2010
  • Interest in new and renewable energies like solar energy and wind energy is increasing throughout the world due to the rapidly expanding energy consumption and environmental reasons. An essential requirement for wind force power generation is estimating the size of wind energy accurately. Wind energy is estimated usually using meteorological data or field measurement. This study attempted to estimate wind energy density using meteorological data on daily mean wind speed and the Weibull parameters in Seoul, a representative inland city where over 60% of 15 story or higher apartments in Korea are situated, and Busan, Incheon, Ulsan and Jeju that are major coastal cities in Korea. According to the results of analysis, the monthly mean probability density distribution based on the daily mean wind speed agreed well with the monthly mean probability density distribution based on the Weibull parameters. This finding suggests that the Weibull parameters, which is highly applicable and convenient, can be utilized to estimate the wind energy density distribution of each area. Another finding was that wind energy density was higher in coastal cities Busan and Incheon than in inland city Seoul.

A Hybrid Energy Storage System Using a Superconducting Magnet and a Secondary Battery

  • ISE Toshifumi;YOSHIDA Takeshi;KUMAGAI Sadatoshi
    • Proceedings of the KIPE Conference
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    • pp.534-538
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    • 2001
  • Energy storage devices with high energy density as well as high power density are expected to be developed from the point of view of compensation of fluctuating load and generated power by distributed generations such as wind turbines, photovoltaic cells and so on. SMES (Superconducting Magnetic Energy Storage) has higher power density than other energy storage methods, and secondary batteries have higher energy density than SMES. The hybrid energy storage device using SMES and secondary batteries is proposed as the energy storage method with higher power and energy density, the sharing method of power reference value for each storage device, simulation and experimental results are presented.

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Energy-based evaluation of liquefaction potential of uniform sands

  • Sonmezer, Yetis Bulent
    • Geomechanics and Engineering
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    • v.17 no.2
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    • pp.145-156
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    • 2019
  • Since behaviors of loose, dense, silty sands vary under seismic loading, understanding the liquefaction mechanism of sandy soils continues to be an important challenges of geotechnical earthquake engineering. In this study, 36 deformation controlled cyclic simple shear tests were performed and the liquefaction potential of the sands was investigated using three different relative densities (40, 55, 70%), four different effective stresses (25, 50, 100, 150 kPa) and three different shear strain amplitudes (2, 3.5, 5%) by using energy based approach. Experiments revealed the relationship between per unit volume dissipated energy with effective stress, relative density and shear strain. The dissipate energy per unit volume was much less affected by shear strain than effective stress and relative density. In other words, the dissipated energy is strongly dependent on relative density and effective stress. These results show that the dissipated energy per unit volume is very useful and may contain the non-uniform loading conditions of the earthquake spectrum. When multiple regression analysis is performed on experiment results, a relationship is proposed that gives liquefaction energy of sandy soils depending on relative density and effective stress parameters.

Ambiguity of Minimum Strain Energy Density Criterion and Maximum Minimum Strain Energy Density Criterion (최소 변형에너지 밀도 기준의 모호성과 최대 극소 변형에너지 밀도 기준)

  • Gu, Jae-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.7
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    • pp.1155-1162
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    • 2001
  • Sihs minimum strain energy density criterion(SED) often used in the mixed mode problem has the ambiguity of the choice of minimum values. In this paper, as the method to solve the problem of SED, maximum minimum strain energy density criterion is proposed that the crack propagates in the direction of having the maximum among the minimum values of modified strain energy density factor(MS), i.e., sign($\sigma$(sub)$\theta$).Smin.

Correlation Between Fatigue Life of 2.2Ni-0.1Cr-0.5Mo Steel Accompanying Mean Stresses with Cyclic Strain Energy Density (평균응력을 동반하는 2.2Ni-lCr-0.5Mo강의 피로수명과 변형률에너지 밀도와의 상관관계)

  • Koh, Seung-Kee;Ha, Jeong-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.1
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    • pp.167-174
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    • 2003
  • Fatigue damage of 2.2Ni-1Cr-0.5Mo steel used fir high strength pressure tubes and vessels was evaluated using uniaxial specimens subjected to strain-controlled fatigue loading. Based on the fatigue test results from different strain ratios of -2. -i 0, 0.5, 0.75, the fatigue damage of the steel was represented by using a cyclic strain energy density. Mean stress relaxation depended on the magnitude of the applied strain amplitude. The high pressure vessel steel exhibited the cyclic softening behavior. Total strain energy density consisting of the plastic strain energy density and the elastic tensile strain energy density described fairly well the fatigue life of the steel, taking the mean stress effects into account. Compared to other fatigue damage parameters, fatigue life prediction by the cyclic strain energy density showed a good correlation with the experimental fatigue lift within a factor of 3.

Wave Energy Distribution at Jeju Sea and Investigation of Optimal Sites for Wave Power Generation (파력발전 적지 선정을 위한 제주 해역 파랑에너지 분포특성 연구)

  • HONG KEY-YONG;RYU HWANG-JIN;SHIN SEUNG-HO;HONG SEOK-WON
    • Journal of Ocean Engineering and Technology
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    • v.18 no.6
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    • pp.8-15
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    • 2004
  • Wave power distribution is investigated to determine the optimal sites for wave power generation at Jeju sea which has the highest wave energy density in the Korean coastal waters. The spatial and seasonal variation of wave power per unit length is calculated in the Jeju sea area based on the monthly mean wave data from 1979 to 2002 which is produced by the SWAN wave model simulation in prior research. The selected favorable locations for wave power generation are compared in terms of magnitude of wave energy density and distribution characteristics of wave parameters. The results suggest that Chagui-Do is the most optimal site for wave power generation in the Jeju sea. The seasonal distribution of wave energy density reveals that the highest wave energy density occurs in the northwest sea in the winter and it is dominated by wind waves, while the second highest one happens at south sea in the summer and it is dominated by a swell sea. The annual average of wave energy density shows that it gradually increases from east to west of the Jeju sea. At Chagui-Do, the energy density of the sea swell sea is relatively uniform while the energy density of the wind waves is variable and strong in the winter.

The Lithium Ion Battery Technology

  • Lee, Ki-Young
    • Carbon letters
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    • v.2 no.1
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    • pp.72-75
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    • 2001
  • The performance of Li-ion system based on $LiCoO_2$ and Graphite is well optimized for the 3C applications. The charge-discharge mode, the manufacturing process, the cell performance and the thermal reactions affecting safety has been explained in the engineering point of view. The energy density of the current LIB system is in the range of 300~400 Wh/l. In order to achieve the energy density higher than 500 Wh/l, the active materials should be modified or changed. Adopting new high capacity anode materials would be effective to improve energy density.

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