• Title/Summary/Keyword: PFM

Search Result 250, Processing Time 0.026 seconds

Effect of Dietary Protease(bromelain) Treated Feather Meal on the Performance and Nutrient Utilization in Broilers (단백질분해효소(bromelain) 처리 우모분이 Broiler의 생산성과 영양소 이용율에 미치는 영향)

  • Kim, J.H.;Ko, Y.D.
    • Journal of Animal Science and Technology
    • /
    • v.47 no.2
    • /
    • pp.221-232
    • /
    • 2005
  • This study was carried out to investigate the effect of replacing fish meal or soybean meal with feather meal or bromelain treated feather meal in broiler diets on the performances and nutrient utilization. Two hundred and twenty-five broilers were randomly allotted to five dietary treatrnents((1) control, basal diet; (2) PFM 50, 50 % of the fish meal replaced with bromelain treated feather meal; (3) PFM 100, 100% of the fish meal replaced with bromelain treated feather meal; (4) PSM 20, 20 % of the soybean meal replaced with bromelain treated feather meal; and (5) PSM 40, 40% of the soybean meal replaced with bromelain treated feather meal) in a 5-week feeding trial. In the overall period, body weight gain of the PFM 50(1,807 g), PSM 20(1,816 g) and PSM 40(1,823 g) were the highest and that of the PFM 100 was 1,744 g. The body weight gain of the control(1,698 g) was the lowest(p < 0.05) among treatments. Feed conversion was significantly(p< 0.05) improved when bromelain treated feather meal replaced 20% of the fish meal in the basal diet. Digestibilities of dry matter, ether extract, organic matter and phosphorus were not different among the treatments. Digestibility of crude protein of PFM 50(65.87 %), PSM 20(67.18 %) and PSM 40(67.56%) were the highest, and that of the control(54.49%) was the lowest(p < 0.05) among treatments. Arrunonia and hydrogen sulfide gases from the feces were significantly(p < 0.05) decreased in chicks fed the PFM 50, PSM 20 and GFM 40 diets, when observed after 3 weeks of feeding trials. Feed costs of the control and PFM 50 were 604 and 629 won, respectively but that of PSM 50 was 820 won. Therefore, replacement of fish meal with bromelain treated feather meal in the diets for chicks could be useful for economic production.

PFM-Mode Boost DC-DC Convertor for Mobile Multimedia Application (휴대용 멀티기기를 위한 PFM방식의 승압형 DC-DC 변환기)

  • Kim, Ji-Man;Park, Yong-Su;Song, Han-Jung
    • 전자공학회논문지 IE
    • /
    • v.47 no.3
    • /
    • pp.14-18
    • /
    • 2010
  • In this paper, we describe a CMOS DC-DC converter with a variable output voltage(5-7V @100mA) for a portable battery-operated system applications. The proposed DC-DC converter is used along with a Pulse-Frequency Modulation (PFM) method and consists of reference circuit, a feedback resistor, a controller, and an internal oscillator. The integrated DC-DC converter with two external passive components(L,C) has been designed and fabricated on a 0.5um 2-poly 3-metal CMOS process and could be applied to the Personal Digital Assistants(PDA), cellular Phone, Laptop Computer, etc.

Operating Characteristics Analysis Of Bi-Directional DC/DC Converter using PFM control with high efficiency at whole load range (전 부하 영역에서 고효율을 가지는 PFM 제어를 이용한 양방향 DC/DC 컨버터의 동작특성 분석)

  • Kim, Ji-Hwan;Hwang, Sun-Hee;Ryu, Dong-Gyun;Jung, Doo-Yong;Jung, Yong-Chae;Won, Chung-Yuen
    • Proceedings of the KIPE Conference
    • /
    • 2012.07a
    • /
    • pp.29-30
    • /
    • 2012
  • In this paper, a performance of bi-directional DC/DC converter using PFM control at whole load range is analyzed. A bi-directional DC/DC converter using PFM control in this paper can be soft switching operation with LC series resonant circuit. It's difficult to expect a high efficiency at whole load range in general resonant converter because of limitation of soft switching area. Therefore converter used in this paper has a variable frequency PFM control to overcome a limitation of soft switching area and it makes a high efficiency at whole load range by implementing a soft switching at light load area of restricted soft switching. The high efficiency at whole load range is verified by simulation and experimental result.

  • PDF

소형위성 기능시험 및 열주기 시험

  • Park, Jong-Oh;Choi, Jong-Yeon;Kwon, Jae-Wook;Youn, Young-Su;Cho, Seung-Won;Kim, Young-Youn;An, Jae-Chel;Choi, Seok-Won
    • Aerospace Engineering and Technology
    • /
    • v.2 no.2
    • /
    • pp.58-65
    • /
    • 2003
  • KARI Electrical Test Team performed the SOH (State Of Health) test and Thermal Cycling test for small satellite of KOMPSAT-1 PFM at KARI SITC Highbay as per Storage plan every year, and verified that the system/subsystem units function installed on PFM were good without significant degradation causing from long-term storage. This paper describes the test items, test method, test procedure and selected test result data.

  • PDF

A Novel Method to Reduce Crest Factor of Electronic Ballast for Fluorescent Lamps Using Pulse Frequency Modulation (펄스 주파수 변조 기법을 이용한 형광등 안정기의 파고율 저감 기법)

  • Song, Joo-Ho;Lee, Dong-Yun;Song, Joong-Ho;Choi, Ju-Yeop;Choy, Ick;Lim, Myo-Taeg
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.5 no.3
    • /
    • pp.291-299
    • /
    • 2000
  • 형광등의 수명은 형광등 안정기의 시동 시나리오와 형광등 전류의 파고율에 영향을 받는다. 본 논문에서는 특히 파고율을 주로 다루며, 파고율을 줄이기 위한 새로운 방법을 제시하고자 한다. 제안하고자 하는 방법은 펄스 주파수 변조기법(Pulse Frequency Modulation, PFM)을 이용하며, PFC(Power Factor Correction)가 만드는 50% 벨리필 전압 파형을 PFM 제어 신호로 사용한다. 본 논문에서는 제안하는 PFM 제어 기법으로 파고율을 1.7 이하로 낮출 수 있음을 모의 실험과 실험을 통해 확인하여, 제안한 기법의 타당성을 검증한다.

  • PDF

Effect of core design on fracture resistance of zirconia-lithium disilicate anterior bilayered crowns

  • Ko, Kyung-Ho;Park, Chan-Jin;Cho, Lee-Ra;Huh, Yoon-Hyuk
    • The Journal of Advanced Prosthodontics
    • /
    • v.12 no.4
    • /
    • pp.181-188
    • /
    • 2020
  • PURPOSE. The effect of core design on the fracture resistance of zirconia-lithium disilicate (LS2) bilayered crowns for anterior teeth is evaluated by comparing with that of metal-ceramic crowns. MATERIALS AND METHODS. Forty customized titanium abutments for maxillary central incisor were prepared. Each group of 10 units was constructed using the same veneer form of designs A and B, which covered labial surface to approximately one third of the incisal and cervical palatal surface, respectively. LS2 pressed-on-zirconia (POZ) and porcelain-fused-to-metal (PFM) crowns were divided into "POZ_A," "POZ_B," "PFM_A," and "PFM_B" groups, and 6000 thermal cycles (5/55 ℃) were performed after 24 h storage in distilled water at 37 ℃. All specimens were prepared using a single type of self-adhesive resin cement. The fracture resistance was measured using a universal testing machine. Failure mode and elemental analyses of the bonding interface were performed. The data were analyzed using Welch's t-test and the Games-Howell exact test. RESULTS. The PFM_B (1376. 8 ± 93.3 N) group demonstrated significantly higher fracture strength than the PFM_A (915.8 ± 206.3 N) and POZ_B (963.8 ± 316.2 N) groups (P<.05). There was no statistically significant difference in fracture resistance between the POZ_A (1184.4 ± 319.6 N) and POZ_B groups (P>.05). Regardless of the design differences of the zirconia cores, fractures involving cores occurred in all specimens of the POZ groups. CONCLUSION. The bilayered anterior POZ crowns showed different fracture resistance and fracture pattern according to the core design compared to PFM.

Evaluation of Antibiotics Resistance for Human-harmful Bacteria Isolated from Eco-friendly and Practical Cultivation Farms of Hot Pepper and Tomato (고추 및 토마토 친환경 및 관행재배지에서 분리한 인체 유해세균의 항생제 저항성 평가)

  • Lee, Sung-Hee;Do, Jiwon;Kim, Seong Kyeom;Oh, Kwang Kyo;Park, Jae-Ho
    • Korean Journal of Organic Agriculture
    • /
    • v.31 no.4
    • /
    • pp.381-394
    • /
    • 2023
  • This study was conducted to monitor the antibiotics resistance of human-harmful bacteria isolated in the agricultural environment for hot peppers (Capsicum annuum) and tomato (Lycopersicon esculentum). As a result, we isolated 120 bacterial species (34 on fruits, 48 in soil, 21 in water, and 17 in manure), identified them with the 16S rRNA sequence, analyzed minimum inhibitory concentration (MIC) for 26 antibiotics using Sensititre ARIS Hi-Q system and then evaluated whether each bacterial genus acquired resistance for the tested antibiotics or not, according to the CLSI criteria. From difference in MIC between eco-friendly (EFM) and practical (PFM) cultivation farms, Klebsiella spp. isolated from EFM was resistant to ampicillin (AMP) and nalidixic acid (NAL), and that isolated from PFM was resistant to streptomycin (STR) and tetracycline (TET). Enterobacter spp. isolated from EFM was resistant to AMP and azithromycin (AZI), and that isolated from PFM was resistant to AMP, AZI, and STR. Meanwhile, Pseudomonas spp. isolated from EFM and PFM were all resistant to AMP, AZI, cefotaxime (FOT), cefoxitin (FOX), ceftriaxone (AXO), CHL, NAL, and STR. Staphylococcus spp. isolated from EFM and PFM were resistant to gentamycin (GEN), STR, and kanamycin (KAN), and in particular, that from EFM showed resistance for erythromycin (ERY). In conclusion, our study suggested that EFM lead STR antibiotics resistance for human-harmful bacteria to decrease, because only the bacteria isolated from hot pepper and tomato crop with PFM have showed resistance against STR antibiotics, regardless of bacterial genus.

Application of Predictive Food Microbiology Model in HACCP System of Milk (우유의 HACCP 시스템에서 Predictive Food Microbiology Model 이용)

  • 박경진;김창남;노우섭;홍종해;천석조
    • Journal of Food Hygiene and Safety
    • /
    • v.16 no.2
    • /
    • pp.103-110
    • /
    • 2001
  • Predictive food microbiology(PFM) is an emerging area of food microbiology since the later 1980’s. It does apply mathematical models to predict the responses of microorganism to specified environmental variables. Although, at present, PFM models do not completely developed, models can provide very useful information for microbiological responses in HACCP(Hazard Analysis Critical Control Point) system and Risk Assessment. This study illustrates the possible use of PFM models(PMP: Pathogen Modeling Program win5.1) with milk in several elements in the HACCP system, such as conduction of hazard analysis and determination of CCP(Critical Control Points) and CL(Critical Limits). The factors likely to affect the growth of the pathogens in milk involved storage fixed factors were pH 6.7, Aw 0.993 and NaCl 1.3%. PMPwin5.1 calculated generation time, lag phase duration, time to level of infective dose for pathogens across a range of storage (Critical Control Points) and CL(Critical Limits). The factors likely to affect the growth of the pathogens in milk involved storage temperature, pH, Aw and NaCl content. The factors likely to affect the growth of the pathogens in milk involved storage temperature, pH, Aw and NaCl content. The variable factor was storage temperature at the range of 4~15$^{\circ}C$ and the fixed factors were pH 6.7, Aw 0.993 and NaC 1.3%. PMPwin5.1 calculated generation time, lag phase duration, time to level of infective dose for pathogens across a range of storage temperature.

  • PDF

A study on the power factor improvement of the Boost Forward Converter (BF 컨버터의 역률 개선에 관한 연구)

  • 임승하
    • Journal of the Korean Institute of Telematics and Electronics T
    • /
    • v.36T no.3
    • /
    • pp.56-63
    • /
    • 1999
  • In this paper, we realize the active PFC(Power Factor Correction) system of BF (Boost Forward) converter with PWM-PFM control technique to control DC output voltage, and to control the input current with sinusoidal wave synchronized by the converter and inverter using power switching element, FET and IGBT. The control circuit of the suggested Boost converter is implemented with a microprocessor 80C196. After making the ratio of output voltage to current as 50V/1A and the duty ratio greater than 0.5. When input voltage is 30V and boost inductance is 1.1mH. We control the voltage changing rate according to the variation of load resistance using a PWM-PFM control technique. And finally we prove experimentally. PF can be improved up to 0.96 using the current shaping technique.

  • PDF

The Effect of Analysis Variables on the Failure Probability of the Reactor Pressure Vessel by Pressurized Thermal Shock (가압열충격에 의한 원자로 압력용기의 파손확률에 미치는 해석변수의 영향)

  • Jang, Chang-Heui;Jhung, Myung-Jo;Kang, Suk-Chull;Choi, Young-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.28 no.6
    • /
    • pp.693-700
    • /
    • 2004
  • The probabilistic fracture mechanics(PFM) is a useful analytical tool to assess the integrity of reactor pressure vessel(RPV) at the event of pressurized thermal shock(PTS). In PFM, the probabilities of flaw initiation and propagation are estimated by comparing the applied stress intensity factor with the fracture toughness calculated by the simulation of various stochastic variables. It is known that the results of PFM analyses are dependent on the choice of the stochastic parameters and assumptions. Of the various variables and assumptions, we investigated the effects of the RT$_{NDT}$ shift equations, fracture toughness curves, and flaw distributions on the PFM results for the three PTS transients. The results showed that the combined effects of the RT$_{NDT}$ shift equations and fracture toughness curves are complicated and dependent on the characteristics of the transients, the chemistry of the materials, the fast neutron fluence, and so on.