• Journal of Animal Science and Technology
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• v.44 no.6
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• pp.719-726
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• 2002

Nutritional adequacy of growing Thoroughbred horses raised in an alternate feeding system - grazing during late spring through late fall and stable feeding for the rest of seasons - was assessed by determining vitamin E and trace mineral levels in the serum and blood chemistry related to nutrition and health. During the stable feeding in winter and early spring, 50 growing female horses were fed concentrates (1.4% of their body weight), grass hay (0.62%) and alfalfa hay (0.37%). For the grazing period, the same horses were fed supplementary concentrates (1.1%) during late spring through early summer, and concentrates (1.1%) and alfalfa hay (0.5%) during late summer through late fall. Blood samples were collected before grazing in early spring, and during grazing in early summer through late fall. Serum vitamin E, BUN, GTP, total bilirubin and direct bilirubin levels were increased (P<0.01) by grazing compared to those measured before the initiation of grazing. Horses had lower (P<0.01) serum Fe contents in early summer than in late fall or in time of stable feeding. Stable feeding increased (P<0.01) serum Cu content compared to grazing in both early summer and late fall. In late fall, serum Zn level increased (P<0.01) compared to that found in the other seasons. Blood glucose and creatinine levels decreased (P<0.01) after grazing. Results indicate that supplementations of some minerals and vitamin E are not always necessary in diets for growing horses and should be done after careful evaluation of diets with regard to concentrations and biological availability of minerals.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.432-435
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• 2008

Launch vehicle for injecting the satellite into its orbit is composed with propulsion system, guidance and navigation system, telemetry and so on. Among the others, the propulsion system is the most important part, because that is the key factor of failure of launch vehicle. Especially, the most of failures were occurred in time of engine startup. Therefore, the study of the conditions for stable engine startup is needed at the first step of development. The many researches were accomplished for mathematical modeling, stable startup engine and control of liquid propellant rocket engine. But the cavitation problem that can be occurred at an inlet of pump associated with propellant feeding system wasn't considered in these works. In this paper, propulsion system model was integrated with clustered engines and propellant feeding system for the simulations of engine startup. As the results of simulations, the requirements were deduced for the stable engine startup without the cavitation at an inlet of pump.

• Membrane and Water Treatment
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• v.11 no.1
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• pp.79-85
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• 2020

A single-stage deammonification with a sequencing batch reactor (SBR) that simultaneous nitritation, anaerobic ammonia oxidation (anammox), and denitrification (SNAD) occur in one reactor has been widely applied for sidestream of wastewater treatment plant. For the stable and well-balanced SNAD, a feeding strategy of influent wastewater is one of the most important operating factors in the single-stage deammonification SBR. In this study, single-stage deammonification SBR (working volume 30L) was operated to treat a high-strength ammonium wastewater (1200 mg NH₄⁺-N/L) with different feeding strategies (single feeding and nine-step feeding) under the condition without COD. Each cycle of the step feeding involved 6 sub-cycles consisted of aerobic and anoxic periods for partial nitritation (PN) and anammox, respectively. Contrary to unstable performance in the single feeding, the step feeding showed better deammonification performance (0.565 kg-N/m³/day). Under the condition with COD, however, the nitrogen removal rate (NRR) decreased to 0.403 kg-N/m³/day when the Nine-step feeding strategies had an additional denitrification period before sub-cycles for PN and anammox. The NRR was recovered to 0.518 kg-N/m³/day by introducing an enhanced multiple-step feeding strategy. The strategy had 50 cycles consisted of feed, denitrification, PN, and anammox, instead of repeated sub-cycles for PN and anammox. The multiple-step feeding strategy without sub-cycle showed the most stable and excellent deammonification performance: high nitrogen removal efficiency (98.6%), COD removal rate (0.131 kg-COD/m³/day), and COD removal efficiency (78.8%). This seemed to be caused by that the elimination of the sub-cycles might reduce COD oxidation during aerobic condition but increase the COD utilization for denitrification period. In addition, among various sensor values, the ORP pattern appeared to be applicable to monitor and control each reaction step for deammonification in the multiple-step feeding strategy without sub-cycle. Further study to optimize the number of multiple-step feeding is still needed but these results show that the multiple-step feeding strategy can contribute to a well-balanced SNAD for deammonification when treating high-strength ammonium wastewater with COD in the single-stage deammonification SBR.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.619-622
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• 1993

Rumen bacterial amino acids in sheep on urea diet were monitored to assess a possible change in amino acid synthesis as a long term response to high rumen ammonia environment. A sheep was fed a semipurified diet with soybean meal, followed by a diet with urea as a main nitrogen source. Mixed rumen bacteria were harvested from ruminal fluid taken 3 h after feeding (twice in soybean meal feeding and 6 times in urea feeding) and fractionated as cell wall, proteins and protein-free cell supernatant of monitor amino acids in each fraction. Ruminal ammonia concentration at the sampling ranged from 5.7 to 39.5 mgN/dl. Cell wall and protein fractions of mixed rumen bacteria were stable in their amino acid composition regardless of nitrogen sources of diet and the feeding duration. However, protein-free cell supernatant fraction showed a higher alanine proportion with urea feeding (18.6 and 28.2 molar % of alanine for samples from sheep fed soybean meal and urea, respectively) and its duration (20.6 and 32.9 molar % for samples from sheep on urea diet for 1 and 65 days, respectively). Total free amino acid level of bacteria was depressed in the initial period of urea feeding but restored on 65th day of the feeding. These results suggest that an alanine synthesizing system may develop in rumen bacteria as urea feeding becomes longer.

• Clinical and Experimental Pediatrics
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• v.53 no.1
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• pp.7-13
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• 2010

Early nutritional support for preterm infants is critical because such support influences long-term outcome. Minimal enteral feeding should be initiated as soon as possible if an infant is stable and if feeding advancement is recommended as relevant to the clinical course. Maternal milk is the gold standard for enteral feeding, but fortification may be needed to achieve optimal growth in a rapidly growing premature infant. Erythromycin may aid in promoting gastrointestinal motility in cases that exhibit feeding intolerance. Selected preterm infants need vitamins, mineral supplements, and calorie enhancers to meet their nutritional needs. Despite all that is known about this topic, additional research is needed to guide postdischarge nutrition of preterm infants in order to maintain optimal growth and neurodevelopment.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.6
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• pp.685-691
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• 2011

The Bearing preload units are used for stable rotational movements of high speed spindles. The feeding mechanism of the preload unit is important to prevent overheat of bearings and to keep constant bearing load under thermal deformation of spindle unit. In this study, ball slide guide and ball bush as feeding mechanism of preload unit are selected. The maximum static friction force, radial stiffness and damping ratio of ball slide guide with ball load, ball number and ball size are widely investigated. In conclusion, the surface of ball slide guide must be heat treated to reduce static friction force. The number and size of ball are increased to control sensitive bearing preload force.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.596-599
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• 2004

The media transport systems, such as printers, copiers, facsimile, ATMs, cameras, etc., have been widely used and being developed rapidly. In the development of those systems, the media feeding mechanism is an important key technology for the design and development of the media transport systems. In this paper, a multi-degree of freedom sheet model with dynamic contact conditions is presented to understand the mechanism of sticking and jamming. A sheet is modelled as a cantilever beam and the feeding velocity is assumed to be constant. The relation between the feeding velocity and the coefficient of friction for guaranteeing stable feeding is presented. Simulations are performed for a horizontal linear guide and a oblique linear guide, calculating the contact force and contact states of mass points.

• Women's Health Nursing
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• v.2 no.2
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• pp.253-269
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• 1996

This descriptive study was done to investigate the proportion of mothers breast feeding and identify factors which influence breast feeding. The subjects were 320 mother who child under five years of age, living in WonJu and their children who numbered 530. Data collection was conducted at various places in the WonJu area using survey questionnaire. The results were as follows : 1. The proportion of children receiving breast feeding was 23.3%, mixed feeding 31.7%, milk feeding 45.1%. The most frequent duration for breast feeding was one month, the mean duration was six months. 2. The major reasons for breast feeding were for the health of the child 52.5%, for emotional attachment with the child 34.2%, and as the expected way of feeding 29.5%. 3. The major reasons for interrupting breast feeding were jobs 26.1%, illness of the child or mother 16.1% abnormality of the breast of nipple 12.7% others 31%. 4. The major reasons for quitting breast feeding were insufficient breast milk 34.5%, job 19.6%, diarrhea in the child 9.9%. 5. The factors influencing breast feeding were educational status and the presence of a job. 6. The husband's attitude to breast feeding was very positive 82.3% and the subjects were supported by their mothers and husbands. But the major information sources about breast feeding were the mass media 30.4% and relatives 22.0%. 7. The breast feeding mother reported experiencing positive and satisfactory feelings, but the milk feeding mother reported experiencing negative and guilt feelings. Also the breast feeding mothers perceived their children as very healthy with a stable emotional status. The results showed the breast feeding ratio in WonJu to be very low and problematic and the subject mothers strongly need information about breast feeding and support while breast feeding. Therefore it is recommended that an education program for community women and other people, like husbands, and grandmothers, be developed along with an education program for university students and other young people to provide them with preparatory information as they begin to think about marriage and families.

• Journal of Nutrition and Health
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• v.33 no.3
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• pp.271-278
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• 2000

Fecal microflora of 12 breast-fed(BF) and 15 formula-fed(FF) infants were investigated at 1 year after birth and the results were compared to those that had previously been obtained from the same subjects at 1 week after birth, and before and after weaning. At 1 year the two lactation groups showed no significant differences both in frequencies and numbers of each major bacterical species, except eubacteria, which showed higher frequency in FF infants. Bifidobacteria appeared as dominant species in 50% BF infants, heres bacteroides in 73.3% FF infants. Fecal pH was lower, though insignificant, in BF infants(6.5$\pm$0.4) than in FF infants(6.8$\pm$0.5). In BF infants, the number of bifidobacteria, clostridia, and E. coli deceased from birth up to 1 year, whereas the number of bacteroides similar trends to BF infants except that the number of bifidobacteria increased, but insignificantly. This research showed that the floral differences resulted not from the age, but from the types of feeding and that breast feeding and that breast feeding could be better than formula feeding in the BF infants had more stable floral composition and bowels with lower pH, which can play a protection role against pathogen infection.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.185-195
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• 2015

Glucoamylase is an important industrial enzyme. Glucoamylase production by industrial Aspergillus niger strain featured with two major problems: (i) empirical substrate feeding methods deteriorating the fermentation performance; and (ii) the high raw materials cost limiting the economics of the glucoamylase product with delegated specification. In this study, we first proposed a novel three-stage varied-rate substrate feeding strategy for efficient glucoamylase production in a 5 L bioreactor using the standard feeding medium, by comparing the changing patterns of the important physiological parameters such as DO, OUR, RQ, etc., when using different substrate feeding strategies. With this strategy, the glucoamylase activity and productivity reached higher levels of 11,000 U/ml and 84.6 U/ml/h, respectively. The performance enhancement in this case was beneficial from the following results: DO and OUR could be controlled at the higher levels (30%, 43.83 mmol/l/h), while RQ was maintained at a stable/lower level of 0.60 simultaneously throughout the fed-batch phase. Based on this three-stage varied-rate substrate feeding strategy, we further evaluated the economics of using alternative carbon sources, attempting to reduce the raw materials cost. The results revealed that cornstarch hydrolysate could be considered as the best carbon source to replace the standard and expensive feeding medium. In this case, the production cost of the glucoamylase with delegated specification (5,000 U/ml) could be saved by more than 61% while the product quality be ensured simultaneously. The proposed strategy showed application potential in improving the economics of industrial glucoamylase production.