• Title, Summary, Keyword: Feeding Strategy

Search Result 140, Processing Time 0.047 seconds

Characteristics of Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) Production by Ralstonia eutropha NCIMB 11599 and ATCC 17699

  • Song, Jae-Yong;Kim, Beom-Soo
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.10 no.6
    • /
    • pp.603-606
    • /
    • 2005
  • Ralstonia eutropha NCIMB 11599 and ATCC 17699 were grown, and their productions of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] compared. In flask cultures of R. eutropha NCIMB 11599, cell concentration, P(3HB-co-4HB) concentration and polymer content decreased considerably with increases in the ${\gamma}-butyrolactone$ concentration, and the 4HB fraction was also very low (maximum 1.74 mol%). In fed-batch cultures of R. eutropha NCIMB 11599, glucose and ${\gamma}-butyrolactone$ were fed as the carbon sources, under a phosphate limitation strategy. When glucose was fed as the sole carbon source, with its concentration controlled using an on-line glucose analyzer, 86% of the P(3HB) homopolymer was obtained from 201g/L of cells. In a two-stage fed-batch culture, where the cell concentration was increased to 104g/L, with glucose fed in the first step and constant feeding of ${\gamma}-butyrolactone$, at 6g/h, in the second, final cell concentration at 67h was 106g/L, with a polymer content of 82%, while the 4HB fraction was only 0.7mol%. When the same feeding strategy was applied to the fedbatch culture of R. eutropha ATCC 17699, where the cell concentration was increased to 42 g/L, by feeding fructose in the first step and ${\gamma}-butyrolactone$ (1.5g/h) in the second, the final cell concentration, polymer content and 4HB fraction at 74h were 51g/L, 35% and 32 mol%, respectively. In summary, R. eutropha ATCC 17699 was better than R. eutropha NCIMB 11599 in terms of P(3HB-co-4HB) production with various 4HB fractions.

Effects of Various Feeding Methods for Gestating Gilts on Reproductive Performance and Growth of Their Progeny

  • Piao, L.G.;Ju, W.S.;Long, H.F.;Kim, Y.Y.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.23 no.10
    • /
    • pp.1354-1363
    • /
    • 2010
  • This study compared the effect of four different feeding methods for gestating gilts on reproductive performance and growth of their progeny. A total of 40 F1 primiparous sows (Yorkshire${\times}$Landrace) were allotted to four treatments in a completely randomized design (CRD). For treatments, gestating period of sows was divided into three trimesters (0-35 d, 36-90 d and 91-110 d) and different amounts of feed were provided to each treatment group by Flat, Down-Up-Down (DUD), Up-Down-Up (UDU) and Down-Up-Up (DUU) feeding methods. The experimental diet was formulated to meet or exceed the standards of NRC (1998). Body weight gain of gestating gilts from d 0 to 110 was affected by feeding method (p<0.05). When gilts were fed constant feed ration (Flat feeding), less body weight loss was observed during lactation (-0.9 kg, p<0.05) and desirable backfat thickness (average 19.5 mm) was acquired at 110 days of gestation. Feed intake of lactating sows tended to be greater (4.22, 3.60, 3.97 and 4.13 kg/d, p>0.05) as sows in Flat feeding treatment had lower backfat thickness during gestation compared with other treatments (p<0.05). When gestating gilts were fed higher amount of feed during mid-trimester, the number of stillborn (1.4 piglet per litter, p<0.05) and mummies (0.8 piglet per litter, p = 0.25) were increased compared to other treatments. Feeding methods for gestating gilts had no effect on litter weight and gain of litter weight during the nursing period. Flat feeding method resulted in decreased plasma glucose concentration at 7 d postpartum (p<0.05), and increased LH concentration at 21 d postpartum (p<0.01) compared to other treatments. These results suggested that higher feed intake of gestating gilts resulted in detrimental effects on body condition and reproductive performance of sows. When gestating gilts consumed constant feed during gestation (2 kg/d), better reproductive performance and less body weight loss in lactation were observed because sows consumed more feed during the whole lactation period. Consequently, Flat feeding will be a desirable feeding strategy for gestating gilts to maximize reproductive performance, and better body condition of sows without any negative influence on the growth of their progeny.

Attitudes of Pregnant women s husbands to Breast Feeding (임부 남편의 모유수유에 대한 태도 유형 분석)

  • 정혜경;김경희
    • Journal of Korean Academy of Nursing
    • /
    • v.28 no.2
    • /
    • pp.392-402
    • /
    • 1998
  • By using Q-methodology, this study examines the attitudes of pregnant womens' husbands toward breastfeeding. Also, the research provides basic data necessary to develop a strategy for recommending breastfeeding. A total of 112 items for the Q-population were collected from related literature and interviews with the general public, specialists, pregnant women and their husbands. Finally, 38 statements were selected. Twenty one husbands of pregnant women classified these statements on each card on a 1 to 9 point scale(forced normal distribution) and wrote the reasons for both the most supported and the most resisted statements. The materials collected were analyzed by using pc QUANL program. The analysis drew down following fact that even though the attitudes of the husbands of pregnant were very similar, they could be classified to three types according to the motivation and recognition the degree of choosing breastfeeding. Type 1 is the mother's duty supporter, who insists that breastfeeding is completely natural and the proper duty of the mother. Type 2 is the emotional value supporter, who thinks that breastfeeding emotionally affects both the baby and the mother in a positive way. Type 3 is the conditional choice supporter, who chooses the most proper suckling way of feeding according to given conditions.

  • PDF

A study on the combination SCD, Pilot Filter and automatic coagulant feeding system in WTP (정수장 SCM, Pilot Filter와 자동응집제주입시스템의 조합에 관한 연구)

  • 최기선;임기영
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • /
    • pp.19-22
    • /
    • 2001
  • In this paper, Streaming Current Monitor (SCM), Pilot Filter (PF) and Coagulant Feeding System(CFS) for fuzzy neural network are used as a coagulation control method in WTP and the results are compared. Several parameters such as coagulant dosage, pH, and turbidity have been changed to find the response characteristic of each equipment. SCM, PF and CFS responded for certain parameters but the range of sensitivity was different each other. It is demonstrated that WTP will be operated more efficiently when SCM, PF and CFS are used as coagulation control strategy.

  • PDF

Effect of Incorrectly Estimated Parameters on the Control of Specific Growth Rate in E. coli Fed-Batch Fermentation

  • Park, Tai-Hyun;Yoon, Sung-Kwan;Kang, Whan-Koo
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.1 no.1
    • /
    • pp.22-25
    • /
    • 1996
  • An Exponetial feeding strategy has been frequently used in fed-batch fermentation of recombinant E. coli. In this feeding scheme, growth yield and initial cell concentration, which can be erroneously determined, are needed to calculate the feed rate for controlling specific growth rate at the set point. The effect of the incorrect growth yield and initial cell concentration on the control of the specific growth rate was theoretically analyzed. Insignificance of the correctness of those parameters for the control of the specific growth rate was shown theoretically and experimentally.

  • PDF

Torque Ripple Minimization for Induction Motor Driven by a Photovoltaic Inverter

  • Atia, Yousry
    • Journal of Power Electronics
    • /
    • v.9 no.5
    • /
    • pp.679-690
    • /
    • 2009
  • The paper presents a new photovoltaic inverter for stand-alone induction motor application. The proposed system is composed of two stages. First stage is for the photovoltaic dc power feeding and second stage is dedicated to the motor-inverter subsystem and control technique. A direct torque control (DTC) with a novel switching strategy for motor torque ripple minimization is introduced. The novel DTC strategy is based on selecting a suitable voltage vector group for motor torque ripple minimization. A three-level voltage source inverter (VSI) is used instead of a two level inverter because the first has more available vectors and lower ripples in the output current and flux than the second, thus it has lower torque ripples. The photovoltaic array and battery bank are sized and the configuration is indicated based on sun-hour methodology. Simulation results show a comparison between three systems; two level VSI with conventional DTC strategy, three level VSI with conventional DTC, and the proposed system that has a novel DTC switching strategy applied to three level VSI. The results show that the proposed system has lower ripples in the current, flux and torque of the motor.

A Smooth LVRT Control Strategy for Single-Phase Two-Stage Grid-Connected PV Inverters

  • Xiao, Furong;Dong, Lei;Khahro, Shahnawaz Farhan;Huang, Xiaojiang;Liao, Xiaozhong
    • Journal of Power Electronics
    • /
    • v.15 no.3
    • /
    • pp.806-818
    • /
    • 2015
  • Based on the inherent relationship between dc-bus voltage and grid feeding active power, two dc-bus voltage regulators with different references are adopted for a grid-connected PV inverter operating in both normal grid voltage mode and low grid voltage mode. In the proposed scheme, an additional dc-bus voltage regulator paralleled with maximum power point tracking controller is used to guarantee the reliability of the low voltage ride-through (LVRT) of the inverter. Unlike conventional LVRT strategies, the proposed strategy does not require detecting grid voltage sag fault in terms of realizing LVRT. Moreover, the developed method does not have switching operations. The proposed technique can also enhance the stability of a power system in case of varying environmental conditions during a low grid voltage period. The operation principle of the presented LVRT control strategy is presented in detail, together with the design guidelines for the key parameters. Finally, a 3 kW prototype is built to validate the feasibility of the proposed LVRT strategy.

Effects of Starvation, Water Temperature, and Water Flow on the Metamorphosis of Leptocephalus of Japanese Eel Anguilla japonica (절식, 수온 및 유속이 극동산 뱀장어(Anguilla japonica) 렙토세팔루스의 변태 유도에 미치는 영향)

  • Kim, Dae-Jung;Lee, Nam-Sil;Kim, Kyung-Kil;Chang, Dae-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.47 no.5
    • /
    • pp.597-602
    • /
    • 2014
  • We determined the effects of starvation, water temperature, and water flow on the onset of metamorphosis in leptocephali of the Japanese eel Anguilla japonica. Leptocephali larger than 50 mm (ca. 200 days old) were reared in 10-L tanks under different feeding, water temperature, and water flow regimes. Fasted leptocephali metamorphosed earlier and faster than did the fed ones. Metamorphosis was faster in the high water flow tank (1.2 L/min) than in the tank with flow at 0.6 L/min. The duration of metamorphosis was slightly shorter at $26^{\circ}C$ than at $23^{\circ}C$. To conclude, starvation induced the metamorphosis of artificially produced leptocephali larger than 50 mm TL. Increased water flow and water temperature both appear to induce and shorten metamorphosis.

Effect of Dietary Feeding Regimens on Urea and Protein Concentration of Milk in Murrah Buffaloes

  • Roy, B.;Mehla, R.K.;Sirohi, S.K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.18 no.7
    • /
    • pp.973-979
    • /
    • 2005
  • The present study was planned to examine the effect of different feeding regimens on milk urea concentration and milk protein concentration. The objectives are to describe the diurnal variations of milk urea (MU) concentration and to predict plasma urea (PU) concentration from MU concentration. Six lactating Murrah buffaloes were distributed in two groups and were fed two different diets in a crossover design. The diets consisted of leguminous crops as diet 1 (berseem (Trifolium alexandrinum)+concentrate mixture 1+wheat straw)) and non-leguminous crops as diet 2 (oats (Avana sativa)+concentrate mixture 2+wheat straw). All the diets were isocaloric and isonitrogenous. Each diet was fed to the animals for a period of 28 days, followed by a 10 day gap to obviate the carry over effect of the previous diet and then a switch over to the other diet. Digestibility trials were conducted on the last 7 days of each feeding period. Milk samples were collected on day 3, 7, 10, 14, 17, 21, 24 and 28 of the feeding period and blood samples were collected on the same day at morning within 30 minutes after morning milking. The average milk urea (MU) values (mg/dl) differed significantly (p<0.01) and were 44.83${\pm}$0.62 and 42.53${\pm}$0.73, respectively, for diets 1 and 2. Milk urea concentrations (mg/dl) also varied (p 0.01) among the days of feeding period, but were stabilized after 10th day of feeding period. In contrast, diets and days of feeding period had no significant effect on percent milk protein. Plasma urea concentration showed a significant (p<0.01) positive correlation (r = 0.93) with MU concentration. To predict the PU from MU the following equation was developed 'PU = 10.67${\pm}$0.76${\times}$MU (mg/dl) with $R^2$ = 0.87'. A clear diurnal variation of MU was found with lowered morning value (42.04${\pm}$0.68 mg/dl) than the evening value (45.32${\pm}$0.66 mg/dl). Present findings suggested that MU or PU concentration could be used as an indicator to monitor the feeding strategy. Plasma urea can be predicted from MU, whenever interpretation of milk urea data required consideration of diurnal variation.

Diet Composition of Coilia nasus in the Coastal Waters off Gori, Korea (고리 주변해역에서 출현하는 웅어 (Coilia nasus)의 위내용물 조성)

  • Baeck, Gun-Wook;Park, Joo-Myun;Choo, Hyun-Gi;Huh, Sung-Hoi
    • Korean Journal of Ichthyology
    • /
    • v.23 no.2
    • /
    • pp.163-167
    • /
    • 2011
  • The feeding habits of Coilia nasus were studied using 107 specimens collected from January to December 2005 in the coastal waters off Gori, Korea. The size of C. nasus ranged from 8.4 to 29.5 cm in standard length (SL). C. nasus was a carnivore that mainly consumed shrimps and copepods. Its diet also included small quantities of amphipods, euphausiids and chaetognaths. The feeding strategy graphical method reveled than C. nasus was specialized feeder and showed narrow niche width. Both small and large size class of C. nasus mainly consumed shrimps and copepods, and did not showed significant size-related changes in feeding habits. However, the mean number and weight of preys per stomach was higher than large size class than small size class.