• Title/Summary/Keyword: P-delta effects

Search Result 397, Processing Time 0.026 seconds

The Age-Related Effect of n-6/n-3 Ratio of Dietary Fats on Lipid Levels and Prostaglandin Production in Rats (식이 다가 불포화 지방산의 n-6/n-3 비율에 의한 흰쥐의 지질수준 및 Prostaglandin 생성에 대한 연령별 비교)

  • 이준호
    • Journal of Nutrition and Health
    • /
    • v.28 no.2
    • /
    • pp.95-106
    • /
    • 1995
  • The effects of various n-6/n-3 ratios(about 2, 4, 6, 8) of dietary fatty acids on various lipid levels and prostaglandin production were studied at the constant P/S ratio (1.5-1.6) in young (5 weeks old) and adult(8 months old) Sprague-Dawley rats using palm oil, safflower oil and sardine oil. The concentration of serum cholesterol tended to increase with the increasing n-6/n-3 ratio. The tendency of HDL-cholesterol levels was similar to serum cholesterol levels. These were not apparent differences between young and adults rats. Serum triglyceride levels increased according to increasing n-6/n-3 ratio in young rats. These were generally high in the adult rats compared with the young rats. Though liver cholesterol level tended to increase according to the increasing n-6/n-3 ratio in the young rats. The liver triglyceride level did not change according to the n-6/n-3 ratio. However, these levels were apparently higher in the adult than in the young rats. The fatty acid compositions of phosphatidylcholine(PC) were similar in serum and liver. The arachidonate/linoleate ratios in tissue PC were influenced by the n-6/n-3 ratio. They tended to be lower in the adult rats compared with the young rats. It was suggested that the activity of $\Delta$6-desturase was decreased by aging. Production of platelet thromboxane A2(TXA2)and aortic prostacyclin(PGI2) was not apparently influenced with n-6/n-3 ratio. Whereas the ratio of TXA2/PGI2 was the lowest value at 3.8 of n-6/n-3 ratio, expecially in the young rats. Thus this ratio seemed to be a desirable level to protect atherosclerosis. These results indicate that the lipid level and prostaglandin production were influenced not only by n-6/n-3 ratio(under constant P/S ratio) but by aging, particulary triglycerde level and arachidonic/linoleic acid ratio.

  • PDF

Effect of Choice Feeding on the Nutrient Intake and Performance of Broiler Ducks

  • Men, Bui Xuan;Ogle, Brian;Lindberg, Jan Erik
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.14 no.12
    • /
    • pp.1728-1733
    • /
    • 2001
  • An experiment was conducted at the experimental duck farm of Cantho University in the Mekong Delta of Vietnam to evaluate the effects of offering pairwise feeds with different crude protein (CP) levels to Cherry Valley broiler ducks from 28-63 days of age on feed intake and performance. Five diets consisting of mixtures of soya bean meal, fish meal, maize meal and fine rice bran, were formulated to give isocaloric diets with 30, 24, 18, 16 and 12% CP. These were offered separately as pellets to growing ducklings in the following combinations: 30+18, 30+12, 24+16 and 18+12. A diet with 20% CP (CP20) was used as control. All the diets were offered ad libitum. Daily feed intakes (g dry matter, DM) were 161, 168, 150, 101 and 143 g for the 30+18, 30+12, 24+16, 18+12 and CP20 treatments, respectively. CP intakes were 29.6, 27.0, 24.8, 17.1 and 22.9% of total DM intake, and the ratio of methionine+cystine to lysine was 0.76, 0.75, 0.75, 0.76 and 0.75 for the 30+18, 30+12, 24+16, 18+12 and CP20 treatments, respectively. Live weights at 63 days of age were 2,937, 3,054, 2,898, 2,200, and 2,811 g (p<0.001), and daily live weight gains 57.8, 61.7, 57.0, 38.5 and 55.7 g (p<0.001) for the 30+18, 30+12, 24+16, 18+12 and CP20 treatments, respectively. The weights and yields of the carcass, breast and thigh muscles, and heart decreased in the order 30+18, 30+12, 24+16, CP20 and 18+12 (p<0.001). The present study suggests that growing broiler offered a combination of high and low protein feeds pairwise will eat excessive amounts of the high protein feed, thus resulting in protein intakes above requirements.

Effects of Dry Roasting on the Vitamin E Content and Microstructure of Peanut (Arachis hypogaea)

  • Eitenmiller, Ronald R;Choi, Sung-Gil;Chun, Jiyeon
    • Journal of agriculture & life science
    • /
    • v.45 no.4
    • /
    • pp.121-133
    • /
    • 2011
  • Effects of roasting on vitamin E content, color, microstructure and moisture of peanuts, and vitamin E content in peanut oils prepared from the roasted peanuts were investigated. Runner-type peanuts were roasted at 140, 150, and $160^{\circ}C$ for 10-20 min. As roasting temperature and time increased, the CIELAB $L^*$ value of peanuts decreased while $a^*$ and $b^*$ values increased, resulting in formation of the golden brown color of roasted peanuts. Moisture ratio (M/Mo) and color $b^*$ value of peanuts roasted at 140 to $160^{\circ}C$ showed a correlation of $b^*=21.61\;(M/Mo)^2-40.62\;(M/Mo)+34.12$ ($R^2=0.9123$). Overall changes in the tocopherol contents of peanuts and peanut oils were significantly affected by roasting temperature and time (p<0.05). Roasting at $140^{\circ}C$ caused a slight increase in the levels of tocopherols of peanuts over roasting time up to 20 min (p<0.05). There was no significant change in the tocopherol levels of peanuts during roasting at $150^{\circ}C$ for 20 min (p>0.05). At $160^{\circ}C$, the levels of tocopherols significantly decreased during the initial 10 min of roasting (p<0.05) while there was no extended loss after 10 min, resulting in about 5, 12, 20, and 10% losses of ${\alpha}$-, ${\beta}$-, ${\gamma}$- and ${\delta}$-T, respectively. After 20 min, total tocopherols decreased by 18%. However, tocopherol contents of pressed peanut oils significantly decreased at all roasting temperatures (p<0.05). After roasting peanuts at $160^{\circ}C$ for 20 min, about 84% of initial ${\alpha}$-T in peanut oils was retained. ${\alpha}$-T was the most stable to roasting while ${\gamma}$-T was the least. Swollen epidermal cells on the inner surface and broken cell walls of parenchyma tissue of peanut cotyledon were observed in peanuts after roasting at $160^{\circ}C$ for 15 min. Severe changes in microstructure of peanut by roasting would contribute to vitamin E stability because of exposure of oil droplets in peanuts to oxygen.

Monte Carlo analysis of earthquake resistant R-C 3D shear wall-frame structures

  • Taskin, Beyza;Hasgur, Zeki
    • Structural Engineering and Mechanics
    • /
    • v.22 no.3
    • /
    • pp.371-399
    • /
    • 2006
  • The theoretical background and capabilities of the developed program, SAR-CWF, for stochastic analysis of 3D reinforced-concrete shear wall-frame structures subject to seismic excitations is presented. Incremental stiffness and strength properties of system members are modeled by extended Roufaiel-Meyer hysteretic relation for bending while shear deformations for walls by Origin-Oriented hysteretic model. For the critical height of shear-walls, division to sub-elements is performed. Different yield capacities with respect to positive and negative bending, finite extensions of plastic hinges and P-${\delta}$ effects are considered while strength deterioration is controlled by accumulated hysteretic energy. Simulated strong motions are obtained from a Gaussian white-noise filtered through Kanai-Tajimi filter. Dynamic equations of motion for the system are formed according to constitutive and compatibility relations and then inserted into equivalent It$\hat{o}$-Stratonovich stochastic differential equations. A system reduction scheme based on the series expansion of eigen-modes of the undamaged structure is implemented. Time histories of seismic response statistics are obtained by utilizing the computer programs developed for different types of structures.

Harmony search based, improved Particle Swarm Optimizer for minimum cost design of semi-rigid steel frames

  • Hadidi, Ali;Rafiee, Amin
    • Structural Engineering and Mechanics
    • /
    • v.50 no.3
    • /
    • pp.323-347
    • /
    • 2014
  • This paper proposes a Particle Swarm Optimization (PSO) algorithm, which is improved by making use of the Harmony Search (HS) approach and called HS-PSO algorithm. A computer code is developed for optimal sizing design of non-linear steel frames with various semi-rigid and rigid beam-to-column connections based on the HS-PSO algorithm. The developed code selects suitable sections for beams and columns, from a standard set of steel sections such as American Institute of Steel Construction (AISC) wide-flange W-shapes, such that the minimum total cost, which comprises total member plus connection costs, is obtained. Stress and displacement constraints of AISC-LRFD code together with the size constraints are imposed on the frame in the optimal design procedure. The nonlinear moment-rotation behavior of connections is modeled using the Frye-Morris polynomial model. Moreover, the P-${\Delta}$ effects of beam-column members are taken into account in the non-linear structural analysis. Three benchmark design examples with several types of connections are presented and the results are compared with those of standard PSO and of other researches as well. The comparison shows that the proposed HS-PSO algorithm performs better both than the PSO and the Big Bang-Big Crunch (BB-BC) methods.

Essence of thermal convection for physical vapor transport of mercurous chloride in regions of high vapor pressures

  • Kim, Geug-Tae;Lee, Kyong-Hwan;Choi, Jeong-Gil
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.17 no.6
    • /
    • pp.231-237
    • /
    • 2007
  • For an aspect ratio (transport length-to-width) of 5, Pr=3.34, Le=0.078, Pe=4.16, Cv=1.01, $P_B=50$ Torr, only thermally buoyancy-driven convection ($Gr=4.83{\times}10^5$) is considered in this study in spite of the disparity in the molecular weights of the component A ($Hg_2Cl_2$) and B which would cause thermally and/or solutally buoyancy-driven convection. The crystal growth rate and the maximum velocity vector magnitude are decreased exponentially for $3{\le}Ar{\le}5$, for (1) adiabatic walls and (2) the linear temperature profile, with a fixed source temperature. This is related to the finding that the effects of side walls tend to stabilize convection in the growth reactor. The rate for the linear temperature profiles walls is slightly greater than for the adiabatic walls far varied temperature differences and aspect ratios. With the imposed thermal profile, a fixed source region, both the rate and the maximum velocity vector magnitude increase linearly with increasing the temperature difference for $10{\le}{\Delta}T{\le}50K$.

Development of seismic collapse capacity spectra for structures with deteriorating properties

  • Shu, Zhan;Li, Shuang;Gao, Mengmeng;Yuan, Zhenwei
    • Earthquakes and Structures
    • /
    • v.12 no.3
    • /
    • pp.297-307
    • /
    • 2017
  • Evaluation on the sidesway seismic collapse capacity of the widely used low- and medium-height structures is meaningful. These structures with such type of collapse are recognized that behave as inelastic deteriorating single-degree-of-freedom (SDOF) systems. To incorporate the deteriorating effects, the hysteretic loop of the nonlinear SDOF structural model is represented by a tri-linear force-displacement relationship. The concept of collapse capacity spectra are adopted, where the incremental dynamic analysis is performed to check the collapse point and a normalized ground motion intensity measure corresponding to the collapse point is used to define the collapse capacity. With a large amount of earthquake ground motions, a systematic parameter study, i.e., the influences of various ground motion parameters (site condition, magnitude, distance to rupture, and near-fault effect) as well as various structural parameters (damping, ductility, degrading stiffness, pinching behavior, accumulated damage, unloading stiffness, and P-delta effect) on the structural collapse capacity has been performed. The analytical formulas for the collapse capacity spectra considering above influences have been presented so as to quickly predict the structural collapse capacities.

Electrical properties of XLPE and Semiconductor Materials for Power Cable (전력케이블의 가교폴리에틸렌과 반도전 재료의 전기적 특성)

  • Lee, Ju-Hong;Kim, Hyang-Kon
    • Proceedings of the KIEE Conference
    • /
    • 2008.09a
    • /
    • pp.207-210
    • /
    • 2008
  • In this paper, we researched the dielectric properties and voltage dependence on slice XLPE sheet from 22[kV] and 154[kV] power cable. We studied effects for impurities and water for semiconductor shield through a dielectric properties experiment to estimate performance of insulating materials in power cable. Capacitance and $tan{\delta}$ of 22[kV], 154[kV] were 53/43[pF] and $7.4{\times}10^{-4}$, $2.1510^{-4}$. In these results, the trend was increased with the increase of temperature. The tan6 of XLPE/semiconductor layer was increased as compared with that of XLPE. Dielectric properties reliability of tan6 was small. Also, To improve mean-life and reliability of power cable in this study, we have investigated chemical properties showing by changing the content of carbon black that is semiconductive additives for underground power transmission. Specimens were made of sheet form with the three of existing resins and the nine of specimens for measurement. Chemical properties of specimens was measured by FT-ATR (Fourier Transform Attenuated Total Reflectance). The condition of specimens was a solid sheet. We could observe functional group (C=O, carbonyl group) of specimens through FT-ATR. From these experimental result, the concentration of functional group (C=O) was high according to increasing the content of carbon black. We could know EEA was excellent more than other specimens from above experimental results.

  • PDF

Natural Dyeing of Ramie Fabrics with Acer Ginnala, Alnus Japonica and Gromwell Extracts (신나무, 오리나무 및 자초를 이용한 라미직물의 천연염색)

  • Kim, Sangyool
    • Journal of Fashion Business
    • /
    • v.18 no.4
    • /
    • pp.15-27
    • /
    • 2014
  • A natural colorant was extracted from Acer ginnala, Alnus japonica and gromwell as extractants. Studies have been made on the effects of the kind of extracts and dyeing/mordanting conditions on colorimetric changes of ramie fabrics. The color of fabrics tended to become darker as the numbers of dyeing process and mordanting process increased using three kinds of extracts. As the numbers of dyeing and mordanting increased, the ramie fabrics gradually increased to show reddish and bluish signs using Acer ginnala, Alnus japonica, and gromwell extracts(500ml and 1,000ml). In the case of 1,500ml of gromwell extracts, the ramie fabrics showed the color with more redness and yellowness. Color difference (${\Delta}E$) of dyed and mordanted fabrics increased as the numbers of dyeing and mordanting processes increased. The apparent colors of ramie fabrics using Acer ginnala were Y and GY. The Alnus japonica extracts produced Y and GY colors on ramie fabrics. With varying amount of gromwell extracts, the colors of dyed and mordanted fabrics were R, YR, GY, G, PB, P and RP, however, the main color was PB. It was concluded that the extracts of Acer ginnala, Alnus japonica and gromwell can be used as a natural dye producing black colors.

Behavior of circular CFT columns subject to axial force and bending moment

  • Kwak, Ji-Hyun;Kwak, Hyo-Gyoung;Kim, Jin-Kook
    • Steel and Composite Structures
    • /
    • v.14 no.2
    • /
    • pp.173-190
    • /
    • 2013
  • The major objective of this paper is to evaluate the behavior and ultimate resisting capacity of circular CFT columns. To consider the confinement effect, proper material models with respect to the confinement pressure are selected. A fiber section approach is adopted to simulate the nonlinear stress distribution along the section depth. Material nonlinearity due to the cracking of concrete and the yielding of the surrounding steel tube, as well as geometric nonlinearity due to the P-${\Delta}$ effect, are taken into account. The validity of the proposed numerical analysis model is established by comparing the analytical predictions with the results from previous experimental studies about pure bending and eccentric axial loading. Numerical predictions using an unconfined material model were also compared to investigate the confinement effects on various loading combinations. The ultimate resisting capacities predicted by the proposed numerical model and the design guidelines in Eurocode 4 are compared to evaluate the existing design recommendation.