• Title/Summary/Keyword: Intermittent feed

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Enhancement of Ultrafiltration Performance Using Ultrasound (초음파를 이용한 한외여과의 성능 향상)

  • 염경호;육영재
    • Membrane Journal
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    • v.13 no.4
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    • pp.283-290
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    • 2003
  • To improve membrane performance, the dead-end and Cross-flow ultrafiltration with or without ultrasound irradiation onto the membrane module were carried out using a BSA protein solution. Intermittent or continuous irradiation of ultrasound effectively suppressed the formation of fouling on membrane or removed the fouling layers from membrane. Effect of ultrasound irradiation on the enhancement of ultrafiltration performance was more increased at the operating conditions which form more membrane fouling (at the operating conditions of higher feed concentration and TMP, and lower flow rate). The permeate flukes were enhanced up to 1.9 times in case of the dead-end ultrafiltration and 1.5 times in case of the cross-flow ultrafiltration by ultrasound irradiation onto the membrane module.

A study on the progressive tool wear and acoustic emission signals in milling process (밀링가공시 발생하는 공구마멸과 AE신호에 관한 연구)

  • 황홍연;이병찬;김광준
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.5
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    • pp.1035-1042
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    • 1988
  • The acoustic emission(AE) signal is monitored in milling operation in order to investigate the relationship between the progressive tool wear and the AE signals. A signal processing technique so called time domain averaging(TDA) is presented for the elimination of the influences of the noise imbedded in the periodic signals. The relationship between the progressive tool wear and the AE signals is investigated by varying the cutting speed, feed, depth of cut and the number of insert. From the measured data, it is observed that the averaged level of the AE signal increases at first with the increase of flank wear to a certain critical value, and then stays almost constant or fluctuates with further increase of the flank wear.

Influence of Lighting Schedule and Nutrient Density in Broiler Chickens: Effect on Growth Performance, Carcass Traits and Meat Quality

  • Li, Wen-Bin;Guo, Yan-Li;Chen, Ji-Lan;Wang, Rong;He, Yao;Su, Dong-Ge
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.11
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    • pp.1510-1518
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    • 2010
  • The study was conducted to evaluate the effect of lighting schedule and nutrient density on growth performance, carcass traits and meat quality of broiler chickens. A total of 576 day old Arbor Acre male chickens was used with a $4{\times}2$ factorial arrangement. The four lighting schedules were continuous (23 L:1 D, CL), 20 L:4 D (12 L:2 D:8 L:2 D), 16 L:8 D (12 L:3 D:2 L:3 D: 2 L:2 D) and 12 L:12 D (9 L:3 D:1 L:3 D:1 L:3 D:1 L:3 D) and provided by incandescent bulbs. The two nutrient densities were high (H, starter diet: 13.39 MJ/kg apparent metabolisable energy (AME), 23.00% crude protein (CP); finisher diet: 13.39 MJ AME/kg, 19.70% CP) and low energy and protein level (L, starter diet: 12.03 MJ AME/kg, 20.80% CP; finisher diet: 12.14 MJ AME/kg, 18.30% CP). Houses with dark curtains and solid sidewalls were used. Chickens were randomly allocated to the 8 treatments with each treatment comprising 6 replicates of 12 chickens. Feed and water were available ad libitum. Lighting schedules showed no difference (p>0.05) in growth performance at the end of the experiment. 12 L:12 D significantly reduced (p<0.05) the concentration of malondialdehyde (MDA) compared to 23 L:1 D treatment. Intermittent lighting (IL) schedules produced higher protein content (p<0.001) in breast meat. Birds on high density diets had higher body weight (BW), feed intake (FI) (p<0.001), and feed conversion ratio (FCR) (p<0.001) throughout the experiment with the exception of 36 to 42 d. High nutrient density increased (p<0.05) abdominal fat, decreased (p<0.05) the moisture loss of meat, and reduced percentage of wings and legs. There was a significant lighting schedule${\times}$diet interaction (p<0.001) on FCR for days 8 to 14 and 15 to 21. Results indicated that IL can give similar growth performance in comparison with CL, meanwhile with positive effects on meat quality by increasing protein content and decreasing the concentration of MDA. High nutrient density resulted in greater growth performance.

Some Effects of Alternate Feeding of High-protein and Low-protein Diets to Growing Rats (고단백질(高蛋白質)과 저단백질(低蛋白質) 사료(飼料)의 교대급여(交代給與)가 쥐의 성장(成長)에 미치는 영향(影響))

  • Kim, Y.K.;Han, I.K.
    • Journal of Nutrition and Health
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    • v.7 no.4
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    • pp.1-5
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    • 1974
  • Forty weaning albino rats were used to find the effects of alternate feeding of high protein diet with different intervals on growth, feed efficiency, protein efficiency ratio, weight of some internal organ, protein digestibility and nitrogen balance. Results obtained are summarized as follows: 1. The growth rate and feed efficiency of group B fed high protein and low protein alternately in every other day was equal to that of A group fed medium protein diet daily. However, the rats fed high protein diet once every three days or every four days could not result in same growth that obtained by group A. 2. The protein efficiency ratio of each group was the same without significant difference. 3. The liver weight appeared to be in proportion to final body weight, but intestine weight and length appeared not to be affected by treatments. 4. The protein digestibility in each group was insignificant. However, urinary nitrogen loss of intermittent high protein feeding group was lower than that of control group and the nitrogen retention ratio decreased with increased nitrogen intake.

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Pig slurry treatment by the pilot scale hybrid multi-stage unit system (HMUS) followed by sequencing batch reactor (SBR) (HMUS와 SBR 반응조를 이용한 축분처리에 관한 연구)

  • Lee, Young-Shin;Han, Gee-Bong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.21 no.2
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    • pp.63-70
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    • 2013
  • Experiments in a pilot-scale hybrid multi-stage unit system (HMUS) combination of ATAD and EGSB followed by SBR process for pig slurry treatment were conducted to demonstrate the feasibility of using autothermal thermophilic aerobic digestion (ATAD) and expended granular sludge bed (EGSB) followed by sequencing batch reactor (SBR) system. Contaminants in pig slurry with high organic matter, nitrogen (N) and phosphorus (P) content were completely removed in the combined process. The highest removal rate for CODcr among contaminants in the feed pig slurry was attained by about 43.3% in ATAD unit process. Also TS removal rate of 96.5% was attained and the highest in the next coagulation unit process. The highest removal rate of CODcr under operating parameter conditions of OLR(organic loading rate), 3-6Kg $COD/m^3{\cdot}day$ and line velocity, 1.5-4m/h was earned at 3days of HRT. The disinfection of pathogens was effective at 50,000mg/L of TS in ATAD unit process. Biogas production per organic removal was $2.3{\sim}8.5m^3/kgTS{\cdot}d$ (average $5.2m^3/kgTS{\cdot}d$) in EGSB unit process. The average removal rates of CODcr 71.7%, TS 64.1%, TN 45.9%, and TP 50.4% were earned in the intermittent aeration SBR unit process.