• Title/Summary/Keyword: N/S ratio

Search Result 2,618, Processing Time 0.036 seconds

Effect of Xylanase on Performance and Apparent Metabolisable Energy in Starter Broilers Fed Diets Containing One Maize Variety Harvested in Different Regions of China

  • O'Neill, H.V. Masey;Liu, N.;Wang, J.P.;Diallo, A.;Hill, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.25 no.4
    • /
    • pp.515-523
    • /
    • 2012
  • The objective of this study was to investigate the variability in broiler performance, apparent metabolisable energy (AME) and ileal digestible energy (IDE) between five different maize samples fed with and without xylanase at 16,000 U/kg. Various in vitro characterisations were conducted to determine if any could predict performance or AME. Samples of the maize were harvested in five diverse regions and fed individually in a mash diet as follows (g/kg): test maize 608.3; soya bean meal (SBM) 324.1; poultry fat 25.2; salt 4.6; met 2.6; lys 1.6; thr 0.5; limestone 9.7, dical 18.4; vit/min 5.0; CP 210 and ME (kcal/kg) 3,085. The diets were fed to 720 broilers with 6 replicates, each containing 12 birds per treatment, from 0 to 18 d of age. Maize samples were analysed for starch, protein, crude fibre, fat, protein solubility index (PSI) and vitreousness using near infra red reflectance spectroscopy (NIR). They were also assayed using an in vitro starch digestibility method. The results showed that there was no effect of harvest region on the feed intake (FI), body weight gain (BWG) or feed conversion ratio (FCR) of the broilers over the 18 d period (p = 0.959, 0.926, 0.819 respectively). There was an improvement in all parameters with the addition of xylanase (FI p = 0.011; BWG and FCR p<0.001). There was a significant positive effect of xylanase on IDE, AME, IDE Intake (IDEI) and AME intake (AMEI) (p<0.0001 in all cases). Although there was no significant effect of maize source, there was a strong trend towards variability in IDE (p = 0.066) and AME (p = 0.058). There were no significant correlations (p<0.05) between any proximate or physiochemical values and any performance or AME values. This may suggest that none of those selected were suitable predictors for performance or AME. The broilers performed well according to the breed guidelines, with slightly increased FI, increased BWG and similar FCR prior to the addition of xylanase. When FCR and BWG were analysed with FI as a covariate, xylanase addition remained significant suggesting that the improvement in BWG and FCR was driven by an increase in digestibility and nutrient availability.

A study of NOx performance for Cu-chabazite SCR catalysts by Sulfur poisoning and desulfation (Cu-Chabazite SCR Catalysts의 황 피독 및 탈황에 의한 NOx 저감 성능에 관한 연구)

  • Nam, Jeong-Gil
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.37 no.8
    • /
    • pp.855-861
    • /
    • 2013
  • Small-pore Cu-chabazite SCR catalysts with high NOx conversion at low temperatures are of interest for marine diesel engines with exhaust temperatures in the range of 150 to $300^{\circ}C$. Unfortunately, fuels for marine diesel engines can contain a high level of sulfur of up to 1.5% by volume, which corresponds to a $SO_2$ level of 500 ppm in the exhaust gases for an engine operating with an A/F ratio of 50:1. This high level of $SO_2$ in the exhaust may have detrimental effects on the NOx performance of the Cu-chabazite SCR catalysts. In the present study, a bench-flow reactor is used to investigate the effects of sulfur poisoning on the NOx performance of Cu-chabazite SCR catalysts. The SCR catalysts were exposed to simulated diesel exhaust gas stream consisted of 500 ppm $SO_2$, 5% $CO_2$, 14% $O_2$, 5% $H_2O$ with $N_2$ as the balance gas at 150, 200, 250 and $300^{\circ}C$ for 2 hours at a GHSV of 30,000 $h^{-1}$. After sulfur poisoning the low-temperature NOx performance of the SCR catalyst is evaluated over a temperature range of 150-$300^{\circ}C$ to determine the extent of the catalyst deactivation. Desulfation is also carried out at 600 and $700^{\circ}C$ for 30 minutes to determine whether it is possible to recover the NOx performance of the sulfur-poisoned SCR Catalysts.

An Evaluation of Fatigue Life and Strength of Lightweight Bogie Frame Made of Laminate Composites (경량 복합재 대차프레임의 피로수명 및 강도 평가)

  • Jeon, Kwang-Woo;Shin, Kwang-Bok;Kim, Jung-Seok
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.35 no.8
    • /
    • pp.913-920
    • /
    • 2011
  • We describe the evaluation of the fatigue life and strength of a lightweight railway bogie frame made of glass fiber/epoxy 4-harness satin-woven composites. To obtain the S-N curve for the evaluation of the fatigue characteristics of the composite bogie frame, we performed a tension-compression fatigue test for composite specimens with different stacking sequences of the warp direction, fill direction, and $0^{\circ}/90^^{\circ}$ direction. We used a stress ratio (R) of -1, a frequency of 5 Hz, and an endurance limit of $10^7$. The fatigue strength of the composite bogie frame was evaluated by a Goodman diagram according to JIS E 4207. The results show that the fatigue life and strength of the lightweight composite bogie satisfy the requirements of JIS E 4207. Given its weight, its performance was better than that of a conventional metal bogie frame based on an SM490A steel material.

Effects of Microbial Phytase Supplementation to Diets with Low Non-Phytate Phosphorus Levels on the Performance and Bioavailability of Nutrients in Laying Hens

  • Um, J.S.;Paik, I.K.;Chang, M.B.;Lee, B.H.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.12 no.2
    • /
    • pp.203-208
    • /
    • 1999
  • An 8 week feeding trial was conducted with 864 ISA Brown laying hens, 48 weeks old, to determine if microbial phytase $(Natuphos^{(R)})$ supplementation can reduce non-phytate phosphorus (NPP) level in laying diets. The experiment consisted of four dietary treatments: T1, control diet with 0.26% NPP (0.55% total P) wand no supplementary phytase; T2, 0.21% NPP (0.50% total P) diet with 250 U of phytase/kg of diet; T3, 0.16% NPP (0.45% total P) diet with 250 U of phytase/kg of diet; and T4, 0.11% NPP (0.40% total P) diet with 250 U of phytase/kg of diet. T3 showed the highest egg production and egg weight and the lowest feed conversion while T4 gave the lowest egg production and the highest feed conversion and mortality. Daily feed consumption ranged from 130.4 g (T4) to 132.7 g (T2). T1 and T2 were not significantly different in the production parameters. Eggshell strength, egg specific gravity, and eggshell thickness were not significantly different among treatments. However, broken egg ratio was significantly lower in T2 and T4 than in T1. Retentions of Ca, P, Mg, and Cu were greater in phytase supplemented treatments (T2, T3, and T4) than the control (T1), and those in T3 and T4 were greater than in T2. Excretions of P in phytase supplemented treatments (T2, T3, and T4) were significantly (p<0.05) smaller than in T1 but excretions of N were not significantly different among the treatments. Contents of ash in tibiae were not significantly affected by treatments, but contents of Ca, P, Mg, and Zn was increased and that of Cu decreased by phytase supplementation. It is concluded that the NPP concentration in the diet of Brown layers consuming about 130 g/d of feed can be safely lowered from 0.26% (0.55% total P) to 0.16% (0.45% total P). The excretion of P was reduced by the inclusion of 250 U phytase/kg of diet.

Antioxidant Effects and Melanin Inhibitory Effect of Natural Pimpinella komarovii Extracts in Jeju Island (제주도 자생 노루참나물 (Pimpinella komarovii) 추출물의 항산화 효과 및 멜라닌 억제 효과)

  • Kang, Min-Chul;Lee, Ju-Yeop;Lee, Jung-A;Han, Jong-Heon;Kim, Bong-Seok;Kim, Gi-Ok
    • KSBB Journal
    • /
    • v.23 no.1
    • /
    • pp.77-82
    • /
    • 2008
  • We investigated several biological activities using the ethanol extract and its fractions from Pimpinella komarovii leaves to evaluate the usefulness of its extract as a functional biomaterial. The ethanol extract showed antioxidant activities, such as DPPH scavenging activity $(IC_{50}=231.8{\mu}g/m{\ell})$. superoxide scavenging activity $(IC_{50}=23.6{\mu}g/m{\ell})$, and xanthine oxidase inhibitory activity $(IC_{50}=587.8{\mu}g/m{\ell})$. Its EtOAc fraction showed the strongest antioxidant activities among several fractions. The inhibitory effect of ethanol extract on tyrosinase activity was higher than water fraction. When $50{\mu}g/m{\ell}$ of EtOAc fraction was applied, the inhibition ratio of tyrosinase activity was much higher (42%) than that of melasolv. The EtOAc fraction also showed higher inhibitory effect on melanogenesis in Melan-a cells. The n-hexane and EtOAc fractions dose-dependently inhibited the NO production in a RAW 264.7 cells. These results suggest that extract of Pimpinella komarovii could be used as functional biomaterial in developing a skin whitening agent having the antioxidant activity.

Reformation of Naphtha Cracking Bottom Oil for the Preparation of Carbon Fiber Precursor Pitch (탄소섬유용 프리커서 피치를 제조하기 위한 나프타 분해 잔사유의 개질)

  • Kim, Myoung Cheol;Eom, Sang Yong;Ryu, Seung Kon;Edie, Dan D.
    • Korean Chemical Engineering Research
    • /
    • v.43 no.6
    • /
    • pp.745-750
    • /
    • 2005
  • Naphtha cracking bottoms(NCB) oil was reformed by varying the heat treatment temperature, treatment time, and nitrogen flow rate in preparation of precursor pitch for isotropic pitch-based carbon fibers and activated carbon fibers. The reformed pitches were investigated in the yield, softening point, elementary analysis, and molecular weight distribution, and then the precursors reformed were melt spun to certify the optimum reforming conditions. The optimum precursor pitch was prepared when the NCB oil was reformed at $380^{\circ}C$, 3 h and 1.25 vvm $N_2$, and it's the softening point was around $240^{\circ}C$. The reforming resulted in product yield of 21 wt%. The C/H mole ratio of the precursor pitch increased from 1.07 to 1.34, the aromaticity increased from 0.85 to 0.88. The insolubles in benzene and quinoline were 30.0 wt% and 1.5 wt%, respectively. The spinning temperature was about $50^{\circ}C$ higher than the softening point. The molecular weights of the precursor components were distributed from 250 to 1250, and 80% of them were in the range of 250 to 700.

Oxidative Desulfurization of Marine Diesel Using WOx/SBA-15 Catalyst and Hydrogen Peroxide (WOx/SBA-15 촉매와 과산화수소를 이용한 선박용 경유의 산화 탈황 연구)

  • Oh, Hyeonwoo;Kim, Ji Man;Huh, Kwang-Sun;Woo, Hee Chul
    • Korean Chemical Engineering Research
    • /
    • v.55 no.4
    • /
    • pp.567-573
    • /
    • 2017
  • In this work, tungsten oxide ($WO_x$) supported on SBA-15 (mesoporous silica) were prepared and applied for oxidative desulfurization of sulfur compounds in marine diesel containing about 230 ppmw of sulfur concentration. Prepared catalysts were examined by two steps; at first step, oxidation reaction carried out with hydrogen peroxide as oxidant and then the oxidized sulfur compounds were extracted by acetonitrile as solvent. Catalysts were characterized by using X-ray diffraction, X-ray fluorescence, X-ray photoelectron spectroscopy and $N_2$ adsorption-desorption isotherms. Tungsten oxide exists as monoclinic crystal system on SBA-15 and over about 10 wt% of the $WO_x$ loading took the form of multi-layers on SBA-15. The 13 wt% $WO_x$/SBA-15 catalyst exhibite highest activity, achieving about 76.3% sulfur removal in the reaction conditions, such as catalyst amount of 0.1 g, reaction temperature at $90^{\circ}C$, reaction time for 3 h and O/S molar ratio of 10. One time oxidation reaction is enough oxidize the sulfur compounds in marine diesel completely. The repetition experiment of extraction process indicated that sulfur removal could reach 94.4% after 5 times.

Blood Pressure and Dietary Related Risk Factors Associated with High Sodium Intake Assessed with 24-hour Urine Analysis for Korean Adults (한국 성인들의 24시간 소변 분석법에 근거한 고나트륨군의 혈압과 고나트륨 섭취관련 위험인자에 관한 연구)

  • Jeong, Yeon-Seon;Lim, Hwa-Jae;Kim, Sook-Bae;Kim, Hee Jun;Son, Sook Mee
    • Korean Journal of Community Nutrition
    • /
    • v.19 no.6
    • /
    • pp.537-549
    • /
    • 2014
  • Objectives: This study was conducted to examine blood pressure and other characteristics of a high sodium intake group assessed with 24-hr urine analysis and the dietary factors related to the risk of high sodium intake among Korean adults. Methods: A cross-sectional study was conducted with adults aged 20-59 years. Subjects who completed 24-hr urine collection (N = 205) were divided into 3 groups (tertile) according to the sodium intake estimated with 24-hour urine analysis. We compared the blood pressure, BMI and dietary related factors of the 3 groups (low, medium, high sodium intake group) with General Linear Model (GLM) and Duncan's multiple range test (p < 0.05). The risk factors related to high sodium intake were assessed with odds ratio (p < 0.05). Results: The sodium intake (mg/day) of the 3 groups were $3359.8{\pm}627.9$, $4900.3{\pm}395.1$ and $6770.6{\pm}873.9$, respectively, corresponding to daily salt intake (g/day) 8.5, 12.4 and 17.2, respectively. High sodium group showed significantly elevated age, BMI and systolic/diastolic blood pressure. Being male gender was associated with significantly increased risk of sodium intake (OR = 1.972; 95%CI: 1.083-3.593). The other factors related to high sodium intake were higher BMI (${\leq}25$) (OR = 2.619; 95% CI: 1.368-5.015), current alcohol consumption (OR = 1.943; 95%CI: 1.060-3.564), and having salty soybean paste with salt percentage > 14% (OR = 3.99; 95% CI: 1.404-6.841). The dietary attitude related to increased risk of high sodium intake included 'enjoy dried fish and salted mackerel' (p < 0.001) and 'eat all broth of soup, stew or noodle' (p < 0.001). Conclusions: Because high sodium intake was associated with higher blood pressure, nutrition education should focus on alcohol consumption, emphasis on related dietary factors such as using low salt soybean paste, improvements in the habit of eating dried fish and salted mackerel or eating all broth of soup, stew or noodle.

Investigation of Transformation Efficiency of Rice Using Agrobacterium tumefaciens and High Transformation of GPAT (glycerol-3-phosphate acyltransferase) Gene Relative to Chilling Tolerance (Agrobacterium tumefaciens를 이용한 벼의 형질전환 효율의 검토 및 내한성 관련 GPAT (glycerol-3-phosphate acyltransferase) 유전자의 형질전환)

  • Seo, Mi-Suk;Bae, Chang-Hyu;Choi, Dae-Ock;Rhim, Seong-Lyul;Seo, Suk-Chul;Song, Pill-Soon;Lee, Hyo-Yeon
    • Journal of Plant Biotechnology
    • /
    • v.29 no.2
    • /
    • pp.85-92
    • /
    • 2002
  • This study has been focused on improving transformation efficiency of rice using Agrobacterium tumefaciens. We have demonstrated the effect of this system when the GPAT gene related to the cold-resistance was transferred by Agrobacterium tumefaciens in rice. Transformation conditions were modified using intron $\beta$-glucuronidase (GUS) expression as a reporter gene in the rice. In this study, mature seed-derived calli of rice (Oruza sativa L. cv. Dongjin) were pre-cultured for 3 days and then infected with Agrobacterium. When this infected calli were cultured in the dark for 10 days on co-cu]lure medium containing 50 mg/L of CaCl$_2$, 30 mg/L of acetosyringone, 2 mg/L of 2,4-D, 120 mg/L of betaine, high GUS expression was observed. In the present transformation system, the efficiency of transformation of GPAT gene was about 54%. Stable integration of GPAT gene into chromosomal DNA was proven by southern blot analysis of genomic DNA isolated from T$_{0}$ progenies. The progenies (T1 generation) derived from primary transformant of 5 lines were segregated with a 3 (resistant) : 1 (sensitive ratio) in medium containing hygromycin. This high frequency transformation system can be used as a useful tool in transformation of another monocotyledon.n.

Active Control of Harmonic Signal Based on On-line Fundamental Frequency Tracking Method (실시간 기본주파수 추종방법에 근간한 조화 신호의 능동제어)

  • 김선민;박영진
    • Journal of KSNVE
    • /
    • v.10 no.6
    • /
    • pp.1059-1066
    • /
    • 2000
  • In this paper. a new indirect feedback active noise control (ANC) scheme barred on the fundamental frequency estimation is proposed for systems with a harmonic noise. When reference signals necessary for feedforward ANC configuration are difficult to obtain, the conventional ANC algorithms for multi-tonal noise do not measure the reference signals but generate them with the estimated frequencies.$^{(4)}$ However, the beating phenomena, in which certain frequency components of the noise vanish intermittently, may make the adaptive frequency estimation difficult. The confusion in the estimated frequencies due to the beating phenomena makes the generated reference signals worthless. The proposed algorithm consists of two parts. The first part is a reference generator using the fundamental frequency estimation and the second one is the conventional feedforward control. We propose the fundamental frequency estimation algorithm using decision rules. which is insensitive to the beating phenomena. In addition, the proposed fundamental frequency estimation algorithm has good tracking capability and lower variance of frequency estimation error than that of the conventional cascade ANF method.$^{(4)}$ We are also able to control all interested modes of the noise, even which cannot be estimated by the conventional frequency estimation method because of the poor S/N ratio. We verify the performance of the proposed ANC method through simulations for the measured cabin noise of a passenger ship and the measured time-varying engine booming noise of a passenger vehicle.

  • PDF