EFFECTS OF AMMONIATED RICE STRAW FEEDING ON MICROBES AND THEIR FERMENTATION END-PRODUCTS IN THE RUMEN AND CAECUM OF SHEEP

Cann, I.K.O.,Kobayashi, Y.,Wakita, M.,Hoshino, S. Asian Australasian Association of Animal Productio 1993 Animal Bioscience Vol.6 No.1

Three sheep fitted with cannulas in the rumen and the caecum were used in a $3{\times}3$ Latin square design to study the changes in ruminal and caecal microbial populations and their metabolite composition with ammoniated rice straw feeding. The 3 diets contained either 80% untreated rice straw (UTS) or ammoniated rice straw (ATS) and 20% formula feed. These were a control diet (C), a urea supplemented diet (U) containing urea at 1.1% and an ammoniated rice straw diet (AT). Data were analyzed by analysis of variance and means separated by the Student Neumann Kuel's multiple comparison. AT feeding increased ruminal bacterial counts, in particular cellulolytic bacterial counts (p < 0.05) which were 1.8, 2.4 and 7.0 (${\times}10^6/ml$ ruminal fluid) for C, U and AT, respectively. There was an increasing tendency (p < 0.10) in ruminal fungal population with U; values were 2.0, 5.2, 3.1 (${\times}10^3/ml$ ruminal fluid) for C, U and AT, respectively. Ruminal protozoa counts were not significantly (p > 0.05) altered with diets. Caecal total viable bacterial count with AT was about thrice the value with C. Total VFA concentration in the rumen was significantly increased (p < 0.025) (7.7 mmol/dl for C and 8.2 mmol/dl for AT) and correspondingly, pH lowered when AT was fed. Sheep on AT tended to produce less acetate and more butyrate in the rumen without significance (p > 0.05). Similar to the rumen, total VFA concentrations of 4.4, 3.8 and 5.2 mmol/dl were detected, respectively, for C, U and AT. Caecal ammonia-nitrogen concentrations were about six-fold of that in the rumen, though there were no differences (p > 0.05) among treatments.

핵심어 검출을 이용한 학과목명 인식

백인찬,권영헌,이건상,김준성 漢陽大學校 自然科學硏究所 1999 自然科學論文集 Vol.18 No.-

본 연구에서는 자연스럽게 발음한 문장내에 포함되어 있는 학과목명을 인식하도록 하였다. 특징벡터로는 Cepstrum, LSF(Line Spectrum Frequency), 그리고 주파수 대역별 에너지를 사용하였고 인식알고리즘으로는 DHMM(Discrete Hidden Markov Model)을 사용하였다. This paper describes the keyword spotting method that recognizes a subject name in naturally spoken sentence. Cepstrum, Linear spectrum frequency, and the normalized energies in frequency domain are used as feature vectors. We used DHMM for recognition algorithm.

Molecular Analysis of Archaea, Bacteria and Eucarya Communities in the Rumen - Review-

White, B.A.,Cann, I.K.O.,Kocherginskaya, S.A.,Aminov, R.I.,Thill, L.A.,Mackie, R.I.,Onodera, R. Asian Australasian Association of Animal Productio 1999 Animal Bioscience Vol.12 No.1

If rumen bacteria can be manipulated to utilize nutrients (i.e., ammonia and plant cell wall carbohydrates) more completely and efficiently, the need for protein supplementation can be reduced or eliminated and the digestion of fiber in forage or agricultural residue-based diets could be enhanced. However, these approaches require a complete and accurate description of the rumen community, as well as methods for the rapid and accurate detection of microbial density, diversity, phylogeny, and gene expression. Molecular ecology techniques based on small subunit (SSU) rRNA sequences, nucleic acid probes and the polymerase chain reaction (PCR) can potentially provide a complete description of the microbial ecology of the rumen of ruminant animals. The development of these molecular tools will result in greater insights into community structure and activity of gut microbial ecosystems in relation to functional interactions between different bacteria, spatial and temporal relationships between different microorganisms and between microorganisms and reed panicles. Molecular approaches based on SSU rRNA serve to evaluate the presence of specific sequences in the community and provide a link between knowledge obtained from pure cultures and the microbial populations they represent in the rumen. The successful development and application of these methods promises to provide opportunities to link distribution and identity of gastrointestinal microbes in their natural environment with their genetic potential and in situ activities. The use of approaches for assessing pupulation dynamics as well as for assessing community functionality will result in an increased understanding and a complete description of the gastrointestinal communities of production animals fed under different dietary regimes, and lead to new strategies for improving animal growth.

The improvement in dielectric and ferroelectric performance of PZT??PZN ceramics by thermal treatment

Naratip Vittayakorn,Gobwute Rujijanagul,David P. Cann 한국물리학회 2007 Current Applied Physics Vol.7 No.5

Pyrochlore-free lead zirconate titanate lead zinc niobate ceramics have been systematically investigated in the as-sintered conditionas well as after annealing. The ceramics were characterized by dielectric spectroscopy and SawyerTower polarization (PE) measure-ments. The powders of Pb[(Zr1/2Ti1/2)(1. x)(Zn1/3Nb 2/3)x]O3, wherex = 0.1, 0.3 and 0.5 were prepared using the columbite(wolframite)precursor method. The general trend seems to indicate that the annealed samples become more normal-ferroelectric-like behavior asopposed to the relaxor-ferroelectric-like behavior observed in the as-sintered state. The as-sintered 0.9PZT0.1PZN ceramic exhibitedweak relaxor-ferroelectric behavior, with a relatively low dielectric constant maximum of 14,000 measured at 1 kHz. Annealing resultedin a transition to normal-ferroelectric-like behavior, a shift in the dielectric maximum temperature from 360.C to 350.C, and a dramaticincrease in the dielectric constant at 1 kHz to a maximum value of 35,000 for the longer anneal. After thermal annealing at 900.week a strong enhancement of remanent polarization (Pr) was observed.

Enhanced piezoelectric properties near the morphotropic phase boundary in lead-free (1-x)(Bi0.5K0.5)TiO3-xBi(Ni0.5Ti0.5)O3 ceramics

Parkpoom Jarupoom,Pharatree Jaita,Rattikorn Yimnirun,Gobwute Rujijanagul,David P. Cann 한국물리학회 2015 Current Applied Physics Vol.15 No.11

Lead-free piezoelectric ceramics of the composition (1-x)(Bi0.5K0.50)TiO3-xBi(Ni0.50Ti0.50)O3 or (1-x)BKTxBNiT (when x = 0-0.20 mol fraction) were prepared by a conventional mixed-oxide method and sintered at 1050 ℃ for 4 h. The effects of BNiT content on the phase equilibria, and the dielectric, ferroelectric and piezoelectric properties were systematically investigated. High density sintered specimens (5.71-6.12 g/cm3) were obtained for all compositions. X-ray diffraction patterns showed that all BKTBNiT samples exhibited a single perovskite phase which confirms that BNiT and BKT formed a solid solution up to x = 0.20. A morphotropic phase boundary (MPB) separating a BKT-rich tetragonal phase and a BNiT pseudo-cubic phase was identified over the compositional range 0.05 < x < 0.10, where enhanced electrical properties were observed. The optimum dielectric properties (εr = 1710, tand = 0.036), ferroelectric properties (Pr = 16.6 mC/cm2, Ec = 22.5 kV/cm and Rsq = 0.86) and piezoelectric properties (d33 = 288 pC/N, Smax = 0.22% and d* 33 = 313 pm/V) were observed with a relatively high Tm ~ 304 ℃ within this MPB region. Overall, these results indicate that the BKT-BNiT ceramic system is a promising lead-free piezoelectric candidate for further development for actuator applications.

Piezoelectric properties of (1 ? x)Pb(Zr1/2Ti1/2)O3?xPb(Zn1/3Nb2/3)O3 ceramics prepared by the columbite?(wolframite) precursor method

N. Vittayakorn,C. Puchmark,G. Rujijanagul,X. Tan,D.P. Cann 한국물리학회 2006 Current Applied Physics Vol.6 No.3

Solid solutions of the perovskite structure, (1. x)Pb(Zr1/2Ti1/2)O3xPb(Zn1/3Nb 2/3)O3 withx = 0.10.5, were synthesized via the col-umbite(wolframite) precursor method. The phase development of calcined powder precursors was analyzed by X-ray diraction. Phase-pure perovskite of PZNPZT ceramics was obtained over a wide compositional range. The microstructure and piezoelectric propertieswere characterrized by means of scanning electron microscopy (SEM),d33 measurements and impedance analysis. It has been found thatof d33 (690 pC/N) and the highestkp (0.7) were recorded for the compositionx = 0.3 located at the boundary between tetragonal andrhombohedral ferroelectric phases. Furthermore, large values ofd33 (600 pC/N) and kp (0.67) were observed at a compositions ofx = 0.5, which is the boundary between two ferroelectric rhombohedral phases.

— Invited Review — Hydrogen production and hydrogen utilization in the rumen: key to mitigating enteric methane production

Mackie Roderick I.,Kim Hyewon,Kim Na Kyung,Cann Isaac 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.2

Molecular hydrogen (H₂) and formate (HCOO^-) are metabolic end products of many primary fermenters in the rumen ecosystem. Both play a vital role in fermentation where they are electron sinks for individual microbes in an anaerobic environment that lacks external electron acceptors. If H₂ and/or formate accumulate within the rumen, the ability of primary fermenters to regenerate electron carriers may be inhibited and microbial metabolism and growth disrupted. Consequently, H₂- and/or formate-consuming microbes such as methanogens and possibly homoacetogens play a key role in maintaining the metabolic efficiency of primary fermenters. There is increasing interest in identifying approaches to manipulate the rumen ecosystem for the benefit of the host and the environment. As H₂ and formate are important mediators of interspecies interactions, an understanding of their production and utilization could be a significant starting point for the development of successful interventions aimed at redirecting electron flow and reducing methane emissions. We conclude by discussing in brief ruminant methane mitigation approaches as a model to help understand the fate of H₂ and formate in the rumen ecosystem. Molecular hydrogen (H2) and formate (HCOO– ) are metabolic end products of many primary fermenters in the rumen ecosystem. Both play a vital role in fermentation where they are electron sinks for individual microbes in an anaerobic environment that lacks external electron acceptors. If H2 and/or formate accumulate within the rumen, the ability of primary fermenters to regenerate electron carriers may be inhibited and microbial metabolism and growth disrupted. Consequently, H2- and/or formate-consuming microbes such as methanogens and possibly homoacetogens play a key role in maintaining the metabolic efficiency of primary fermenters. There is increasing interest in identifying approaches to manipulate the rumen ecosystem for the benefit of the host and the environment. As H2 and formate are important mediators of interspecies interactions, an understanding of their production and utilization could be a significant starting point for the development of successful interventions aimed at redirecting electron flow and reducing methane emissions. We conclude by discussing in brief ruminant methane mitigation approaches as a model to help understand the fate of H2 and formate in the rumen ecosystem.

Effects of Zr/Ti ratio on dielectric and ferroelectric properties of 0.8Pb(ZrxTi1-x)O3–0.2Pb(Co1/3Nb2/3)O3 ceramics

Anurak Prasatkhetragarn,Muangjai Unruan,Athipong Ngamjarurojana,Yongyut Laosiritaworn,Supon Ananta,Rattikorn Yimnirun,David P. Cann 한국물리학회 2009 Current Applied Physics Vol.9 No.4

The influences of Zr/Ti ratio on electrical properties of the 0.8Pb(ZrxTi1-x)O3–0.2Pb(Co1/3Nb2/3)O3 ceramics prepared by a mixed-oxide method (with x = 0.46, 0.48, 0.50, 0.52, and 0.54) have been investigated in order to identify the morphotropic phase boundary composition in this system. With XRD analysis, the crystal structure of dense specimens appeared to change gradually from tetragonal to rhombohedral with increasing Zr content. The dielectric properties measurements showed a maximum dielectric constant at x = 0.50, while the transition temperature decreased with increasing Zr content in the system. Moreover, all ceramics showed diffused phase transition behaviors with a minimum diffusivity at x = 0.50. In addition, the Polarization–Electric field (P–E) hysteresis loops of the ceramic systems also changed significantly with the Zr content. Interestingly, the loop squareness parameter reached maximum around x = 0.50. Other ferroelectric hysteresis parameters showed noticeable change at x = 0.50. These results clearly showed the significance of Zr/Ti ratio in controlling the electrical properties of the PZT–PCN ceramic systems. The influences of Zr/Ti ratio on electrical properties of the 0.8Pb(ZrxTi1-x)O3–0.2Pb(Co1/3Nb2/3)O3 ceramics prepared by a mixed-oxide method (with x = 0.46, 0.48, 0.50, 0.52, and 0.54) have been investigated in order to identify the morphotropic phase boundary composition in this system. With XRD analysis, the crystal structure of dense specimens appeared to change gradually from tetragonal to rhombohedral with increasing Zr content. The dielectric properties measurements showed a maximum dielectric constant at x = 0.50, while the transition temperature decreased with increasing Zr content in the system. Moreover, all ceramics showed diffused phase transition behaviors with a minimum diffusivity at x = 0.50. In addition, the Polarization–Electric field (P–E) hysteresis loops of the ceramic systems also changed significantly with the Zr content. Interestingly, the loop squareness parameter reached maximum around x = 0.50. Other ferroelectric hysteresis parameters showed noticeable change at x = 0.50. These results clearly showed the significance of Zr/Ti ratio in controlling the electrical properties of the PZT–PCN ceramic systems.

Dielectric and ferroelectric properties of 0.8PZT–0.2PCN ceramics under sintering conditions variation

Anurak Prasatkhetragarn,Muangjai Unruan,Athipong Ngamjarurojana,Yongyut Laosiritaworn,Supon Ananta,Rattikorn Yimnirun,David P. Cann 한국물리학회 2009 Current Applied Physics Vol.9 No.5

The influences of sintering conditions on electrical properties of the 0.8Pb(Zr1/2Ti1/2)O3–0.2Pb(Co1/3Nb2/ 3)O3 ceramics have been investigated with sintering temperatures of 1175, 1200, 1225, and 1250 ℃ and dwell times for 2, 6, and 10 h. The crystal structure of dense specimens showed coexistence between tetragonal, rhombohedral and pseudo cubic phases in all sintering temperatures, while tetragonal-rich phase appeared with increasing dwell times. A maximum dielectric constant was observed at sintering condition of 1200 ℃ for 2 h, while the transition temperature slightly increased with increasing dwell time. All ceramics also showed diffused phase transition behaviors with a minimum diffusivity at sintering condition of 1200 ℃ for 2 h. In addition, the polarization–electric field (P–E) hysteresis loops of the ceramic systems also changed significantly with sintering conditions. Interestingly, the ferroelectric parameters; remnant polarization (Pr) and loop squareness (Rsq) tended to increase with increasing sintering temperatures and dwell times. The influences of sintering conditions on electrical properties of the 0.8Pb(Zr1/2Ti1/2)O3–0.2Pb(Co1/3Nb2/ 3)O3 ceramics have been investigated with sintering temperatures of 1175, 1200, 1225, and 1250 ℃ and dwell times for 2, 6, and 10 h. The crystal structure of dense specimens showed coexistence between tetragonal, rhombohedral and pseudo cubic phases in all sintering temperatures, while tetragonal-rich phase appeared with increasing dwell times. A maximum dielectric constant was observed at sintering condition of 1200 ℃ for 2 h, while the transition temperature slightly increased with increasing dwell time. All ceramics also showed diffused phase transition behaviors with a minimum diffusivity at sintering condition of 1200 ℃ for 2 h. In addition, the polarization–electric field (P–E) hysteresis loops of the ceramic systems also changed significantly with sintering conditions. Interestingly, the ferroelectric parameters; remnant polarization (Pr) and loop squareness (Rsq) tended to increase with increasing sintering temperatures and dwell times.