• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.305-327
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• 1999

In the paper insight is given in the legislation policy to restrain environmental pollution by pig husbandry, focused on The Netherlands (Mineral Accounting System). Besides, nutritional measures are presented to reduce environmental pollution by lowering excretion of N and P, emphasizing (multi) phase feeding, the use of low protein, synthetic amino acids supplemented diets, phytase and its effect on phosphorus and calcium digestibility, its interaction with phytic acid and proteins, and the environmental impact of the use of phytase in pig diets. Also, nutritional means are indicated to reduce ammonia volatilization from pig operations. It is concluded that nutrition management can substantially contribute to reduction of N and P excretion by pigs, mainly by lowering dietary protein levels, (multi) phase feeding and the use of microbial phytase, and that the use of phytase on a large scale in The Netherlands has a tremendous environmental impact. In 20 years the excretion of P in growing-finishing pigs has more than halved. Ammonia emission from manure of pigs can be reduced substantially by lowering dietary protein content, but also by including additional non-starch polysaccharides in the diet. A very promising method to reduce ammonia emission is to manipulate dietary cation-anion difference, e.g. by adding acidifying salts to the diet, which will lower pH of urine substantially. Further research is desirable. This also applies to determining dietary factors influencing the odour release from manure. Finally, some speculation on the future of pig farming from an environmental viewpoint is presented.

• Journal of Animal Science and Technology
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• v.56 no.1
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• pp.4.1-4.7
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• 2014

The effect of sodium and sodium salts on carcass and body organ characteristics of broilers under a four phase feeding program were investigated. A basal diet (0.08% dNa with NaCl) was formulated and one of two sources of dNa ($NaHCO_3$ and $Na_2SO_4$) were supplemented to obtain four different percentages of dNa (0.17, 0.26, 0.35, and 0.44%) for each treatment. There was a linear decrease in dressing percentage (DP) with source ${\times}$ level interaction ($p{\leq}0.001$), while there was a linear increase in breast yield and thigh yield with increasing dNa supplementation ($p{\leq}0.001$). Chicks fed 0.35% $NaHCO_3$ and 0.44% dNa $Na_2SO_4$ supplemental salts had lower abdominal fat ($p{\leq}0.04$). Chicks that received increasing levels of dNa (from 0.17 to 0.44%) showed increasing gizzard weight ($p{\leq}0.02$) and decreasing spleen weight ($p{\leq}0.02$). When both salts were supplemented at 0.26% dNa, the chicks showed their lowest bursa weight ($p{\leq}0.001$). Consequently, chicks at higher dNa showed an increase in breast and thigh meat yield, and increasing capacity of their digestive organ. The higher levels of dNa should be tested with other cations and anions to fully understand acid base homoeostasis.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.719-727
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• 2021

This study was conducted to evaluate the effects of mixed and separate gender feeding on the growth performance and carcass traits of Korean native chickens (KNC) compared to white semi-broilers (WSB) and a commercial broiler (CB) from hatching to 35 days. Here, 240 chicks were used with eight birds per cage in a randomized design with six replicates per breed. For the KNC lines, three groups of males (KNC-M), mixed-gender birds (KNC-FM) and females (KNC-F) were used. The two-phase feeding program used here consisted of a starter phase (days 1 - 21: crude protein [CP] 20% and metabolizable energy [ME], 3,050 kcal·kg^-1) and a grower phase (days 22 - 35: CP 18%, 3,100 kcal·kg^-1) for a commercial broiler. The WSB and CB were fed the only starter commercial diet. Fresh water and feed were provided ad-libitum. The results revealed that the KNC group had a lower (p < 0.05) body weight (BW) from day 7 and day 35 compared to that of the CB. Furthermore, the KNC group showed a lower (p > 0.05) average daily gain (ADG) relative to that of the CB during the entire experimental period. No difference (p > 0.05) was observed in the shank length among the treatments. There were also no significant differences in the growth performance or carcass traits between the KNC-M and WSB groups or in the genders of the KNC group.

• Polymer(Korea)
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• v.26 no.6
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• pp.759-766
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• 2002

Regular, spherical and isotropic open-microcellular foams having low density were prepared by the high internal phase emulsion (HIPE) polymerization mainly composed of styrene monomer and water The effects of Polymerization conditions. such as the content of water, divinylbenzene as a crosslinking agent and dodecane as a chain transfer agent, were investigated based on the tell size and foam properties. The microstructural morphology was observed using scanning electron microscopy (SEM) and the compression modulus of the foam was evaluated using compression test. The dropwise feeding of the aqueous phase into the oil phase was more effective than the batch feeding in producing the uniform and stable foam. Agitation speed and surfactant strongly influenced on the cell size and the window size between water droplets. Introduction of chain transfer agent increased the cell size, whereas it decreased the window size. Compression modulus increased with the crosslinking agent, but decreased with the chain transfer agent.

• Membrane Journal
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• v.29 no.1
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• pp.61-65
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• 2019

Anisotropic particles have been issued in various fields due to their unique physical properties. Herein, a novel dynamic phase separation method (DPS) is introduced to fabricate anisotropic acorn-like nanoparticles. DPS consists of two dynamic conditions; solvent evaporation and nonsolvent induced precipitation. The bottom layer is controlled by feeding the water as a non-solvent diluent, and the phase separation of the upper layer relies on the diffusion and evaporation of a volatile good solvent. At this condition, the acorn-like particles were fabricated. Under a closed box filled with water (spontaneous phase separation), monodisperse polystyrene (PS) particles were synthesized. At the coexistence between DPS and spontaneous phase separation, the sizes of cap and particle were changed. Also, the volume of PS solutions influences on the particle shape. Since the unique structures could be utilized into various applications, if advanced techniques such as membrane-based controlled water feeding is developed, monodisperse acorn-like particles could be tuned.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1518-1523
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• 2003

This experiment was conducted to investigate the effect of various feeding regimens on growth performance, nutrient digestibilities, nitrogen retention, blood urea nitrogen (BUN) concentration and feed cost in young pigs weaned at 21 days of age. One hundred twenty crossbred pigs (Landrace${\times}$Large White${\times}$Duroc, average 6.8 kg BW), weaned at 21 days of age, were allotted to 5 treatments in a 5 replicates by a randomized completely block (RCB) design. Treatments were as follow: 1) 1P (1-4 weeks: CP 23% and lysine 1.60%), 2) 2P-I (1 week: CP 23% and lysine 1.60%, 2-4 weeks: CP 21% and lysine 1.45%), 3) 2P-II (1-2 weeks: CP 23% and lysine 1.60%, 3-4 weeks: CP 21% and lysine 1.45%), 4) 2P-III (1-3 weeks: CP 23% and lysine 1.60%, 4 week: CP 21% and lysine 1.45%), 5) 3P (1 week: CP 23% and lysine 1.60%, 2-3 weeks: CP 21% and lysine 1.45%, 4 week: CP 19% and lysine 1.30%). Three different diets were formulated and supplied according to phase feeding programs. Diet 1 contains 23% crude protein and 1.60% lysine, diet 2 contains 21% crude protein and 1.45% lysine and diet 3 contains 19% crude protein and 1.30 lysine, respectively. Although there was no significant difference in growth performances, there was a beneficial effect of 3 phase feeding. The ADG was higher in 3P treatment than other treatments and it was observed clearly in late period (3-4 weeks) than in early period. Also, with increase in age, growth rate of pigs in 3P treatment was higher than that in 1P treatment approximately 37% (p=0.1379). There were no significant differences among all treatments in nutrient digestibility. The concentration of BUN was higher in pigs were fed diet containing 21% crude protein and 1.45% lysine (eg, 2P-1 and 3P) than those supplied diet containing high nutrient value at 2 week. The lowest feed cost/kg weight gain of pigs showed in 3P among treatments (p<0.05) whereas, high feed cost/kg weight gain of pigs was calculated in 1P and 2P-II treatments compared with 2P-I and 2 P-II (p<0.05), because of high milk products were used in those diet.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.563-568
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• 1999

Generally the control method of wire feeding motor in welding machine has been used full-wave phase control method. The fire-angle control generates low frequency speed ripple, and it causes the output current ripple. So it results in the variation of welding condition and low welding performances such as spatter generation and bead state. For the purpose of welding performances improvement by speed controller in wire feeding motor, in this paper the constant speed control method for welding machine is proposed. The proposed system is composed of speed control loop and current control loop. As a result of experiment by using proposed constant wire feed experiment by using proposed constant wire feed speed controller, the output voltage and current waveform and metal transfer are maintained stably. And moreover the number of instantaneous short circuit occurrence is reduced remarkably.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.241-244
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• 2006

The analysis of propellant feeding sub-system is performed using a commercial code SINDA/FLUINT, the comprehensive finite-difference, one-dimensional, lumped parameter tool. With the code, cryogenic helium supply system, liquid oxygen supply system, helium injection cooling system are evaluated. The code gave satisfactory estimation scheme for propulsion system characterized by cryogenic temperature and high pressure, two phase flow. This paper focuses on presenting calculation scheme of propulsion sub-system using one-dimensional code like SINDA/FLUINT.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.31-38
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• 2013

The degradation of 4-chlorophenol(4-CP) by various AOPs(Advanced Oxidation Processes) with continuous feeding of $H_2O_2$, including the ultraviolet/hydrogen peroxide, the Fenton and the photo-Fenton process has been investigated. The photo-Fenton process showed the highest removal efficiency for degradation of 4-chlorophenol than those of other AOPs including the Fenton process and the combined UV process with continuous feeding of $H_2O_2$. In the photo-Fenton process, the optimal experimental condition for 4-CP degradation was obtained at pH 3. Also the 4-CP removal efficiency increased with decreasing of the initial 4-CP concentration. 4-chlorocatechol and 4-chlororesorcinol were identified as photo-Fenton reaction intermediates, and the degradation pathways of 4-CP in the aqueous phase during the photo-Fenton reaction were proposed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.211-215
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• 2004

For design of cryogenic propellant feeding system, one of the main requirements is to meet temperature requirement for satisfying turbo-pump NPSH requirement. In this paper improved method of estimating the thermal stratification in liquid oxygen tank is presented to help design. In the case of liquid rocket using turbo-pump, the inner pressure of liquid oxygen tank is maintained low, so vaporization of liquid oxygen is generally occurred. In this paper, inner process of LOX tank is analyzed by two phase flow modeling. The vaporization rate and required helium mass is investigated.