Intranasal Immunization of Pigs against Influenza with Synthetic Peptides Based on the Cassette Theory

Lim, Y. K.,Okazaki, K.,Matsuki, S.,Ogasawara, K.,Kida, H.,Lee, Y. S. 한국수의공중보건학회 1998 예방수의학회지 Vol.22 No.3

MAGNETIC PROPERTIES OF FERRITE CORES UNDER DC - BIASED FIELD

H. Fukunaga,S. Masumoto,Y. Ohta,H. Kakehashi,H. Ogasawara 한국자기학회 1995 韓國磁氣學會誌 Vol.5 No.5

Ferrite cores are often magnetized under DC-biased field because they have been intensively used in electronic circuits such as an inverter circuit and a switching regulator circuit. Thus we investigated the effects of DC-biased field on magnetic properties in the frequency range of DC-100㎑ for two kinds of ferrite cores, TDK PC38 and TDK H₃S, which have different shapes of B-H loop from each other. The magnetic loss per cycle, W/f, in the H₃S core decreased with increasing the strength of DC-biased field, although W/f in the PC38 core increased monotonically with DC-biased field. The observed decreasing tendency differs from the previous result for Si-Fe and ferrite cores, and can be attributed to decrease in eddy current loss as well as that in hysteresis loss.

Effect of HTT on Bending and Tensile Properties of 2D C/C Composites

S.R. Dhakate,T. Aoki,T. Ogasawara 한국탄소학회 2005 Carbon Letters Vol.6 No.4

Bending and tensile properties of 2D cross-ply C/C composites with processing heat treatment temperature (HTT) are evaluated. C/C composites used are made from two types of PAN based T700 and M40 carbon fibers with phenolic resin as carbon matrix precursor. Both the types of composites are heat treated at different temperatures (ranging from 750 to 2800℃) and characterized for bending and tensile properties. It is observed that, real density and open porosity increases with HTT, however, bulk density does show remarkable change. The real density and open porosity are higher in case T-700 carbon fiber composites at 2800℃, even though the density of M40 carbon fiber is higher. Bending strength is considerably greater than tensile strength through out the processing HTT due to the different mode of fracture. The bending and tensile strength decreases in both composites on 1000℃ which attributed to decrease in bulk density, thereafter with increase in HTT, bending and tensile strength increases. The maximum strength is in T700 fiber based composites at HTT 1500℃ and in M40 fiber based composites at HTT 2500℃. After attending the maximum value of strength in both types of composite at deflection HTT, after that strength decreases continuously. Decrease in strength is due to the degradation of fiber properties and in-situ fiber damages in the composite. The maximum carbon fiber strength realization in C/C composites is possible at a temperature that is same of fiber HTT. It has been found first time that the bending strength more or less 1.55 times higher in T700 fiber composites and in M40 fiber composites bending strength is 1.2 times higher than that of tensile strength of C/C composites.

Effect of Silicon Infiltration on the Mechanical Properties of 2D Cross-ply Carbon-Carbon Composites

S.R. Dhakate,T. Aoki,T. Ogasawara 한국탄소학회 2004 Carbon Letters Vol.5 No.3

Effect of silicon infiltration on the bend and tensile strength of 2D cross-ply carbon-carbon composites are studied. It is observed that bend strength higher than tensile strength in both types of composite is due to the different mode of fracture and loading direction. After silicon infiltrations bend and tensile strength suddenly decreases of carbon-carbon composites. This is due to the fact that, after silicon infiltration, silicon in the immediate vicinity of carbon forms the strong bond between carbon and silicon by formation silicon carbide and un-reacted silicon as free silicon. Therefore, these composites consist of three components carbon, silicon carbide and silicon. Due to mismatch between these three components secondary cracks developed and these cracks propagate from 90˚ oriented plies to 0˚ oriented plies by damaging the fibers (i.e., in-situ fiber damages). Hence, secondary cracks and in-situ fiber damages are responsible for degradation of mechanical properties of carbon-carbon composites after silicon infiltration which is revealed by microstructure investigation study by scanning electron microscope.

Effect of Silicon Infiltration on the Mechanical Properties of 2D Cross-ply Carbon-Carbon Composites

Dhakate, S.R.,Aoki, T.,Ogasawara, T. Korean Carbon Society 2004 Carbon Letters Vol.5 No.3

Effect of silicon infiltration on the bend and tensile strength of 2D cross-ply carbon-carbon composites are studied. It is observed that bend strength higher than tensile strength in both types of composite is due to the different mode of fracture and loading direction. After silicon infiltrations bend and tensile strength suddenly decreases of carbon-carbon composites. This is due to the fact that, after silicon infiltration, silicon in the immediate vicinity of carbon forms the strong bond between carbon and silicon by formation silicon carbide and un-reacted silicon as free silicon. Therefore, these composites consist of three components carbon, silicon carbide and silicon. Due to mismatch between these three components secondary cracks developed and these cracks propagate from $90^{\circ}$ oriented plies to $0^{\circ}$ oriented plies by damaging the fibers (i.e., in-situ fiber damages). Hence, secondary cracks and in-situ fiber damages are responsible for degradation of mechanical properties of carbon-carbon composites after silicon infiltration which is revealed by microstructure investigation study by scanning electron microscope.

Effect of HTT on Bending and Tensile Properties of 2D C/C Composites

Dhakate, S.R.,Aoki, T.,Ogasawara, T. Korean Carbon Society 2005 Carbon Letters Vol.6 No.4

Bending and tensile properties of 2D cross-ply C/C composites with processing heat treatment temperature (HTT) are evaluated. C/C composites used are made from two types of PAN based T700 and M40 carbon fibers with phenolic resin as carbon matrix precursor. Both the types of composites are heat treated at different temperatures (ranging from 750 to $2800^{\circ}C$) and characterized for bending and tensile properties. It is observed that, real density and open porosity increases with HTT, however, bulk density does show remarkable change. The real density and open porosity are higher in case T-700 carbon fiber composites at $2800^{\circ}C$, even though the density of M40 carbon fiber is higher. Bending strength is considerably greater than tensile strength through out the processing HTT due to the different mode of fracture. The bending and tensile strength decreases in both composites on $1000^{\circ}C$ which attributed to decrease in bulk density, thereafter with increase in HTT, bending and tensile strength increases. The maximum strength is in T700 fiber based composites at HTT $1500^{\circ}C$ and in M40 fiber based composites at HTT $2500^{\circ}C$. After attending the maximum value of strength in both types of composite at deflection HTT, after that strength decreases continuously. Decrease in strength is due to the degradation of fiber properties and in-situ fiber damages in the composite. The maximum carbon fiber strength realization in C/C composites is possible at a temperature that is same of fiber HTT. It has been found first time that the bending strength more or less 1.55 times higher in T700 fiber composites and in M40 fiber composites bending strength is 1.2 times higher than that of tensile strength of C/C composites.

카세트 이론을 응용한 합성펩타이드 백신의 돼지경비 접종에 의한 면역학적 연구

임윤규,K. Okazaki,S . Matsuki,K . Ogasawara,H . Kida,이영순 한국예방수의학회 1998 예방수의학회지 Vol.22 No.3

Operational Characteristics of a Step-Down Converter Applied Proposed Switching Transient Waveform Modification

T. Mori,T.Igarashi,H. Funato,S. Ogasawara,M. Hara,F.Okazaki,Y. Hirota 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

Recently, high performance power switching device realize high performance power converter. However, high speed turn-on and turn-off cause electromagnetic interference (EMI). EMI filters or wire shields decrease EMI. However, they take over space of automotive, and cost is expense. Authors have proposed a new method to decrease high-frequency noise at specific frequency band with modification of switching transient slope. In order to realize a step-down converter with modified switching slope, there are several problems such as generating PWM signal with modified slope, feasibility in a real chopper circuit, switching loss and so on. In this paper, a step-down converter applied proposed modified switching slope was successfully realized using MT (Modified Transient)-PWM generator. The operational characteristics were analyzed for resistive load.

Intranasal Immunization of Pigs against Influenza with Synthetic Peptides Based on the Cassette Theory

Lim, Y.K.,Okazaki, K.,Matsuki, S.,Ogasawara, K.,Kida, H.,Lee, Y. S. 濟州大學校 農科大學 動物科學硏究所 1998 動物科學論叢 Vol.13 No.1

Synthetic petide vaccines prepared according to the cassette theory(Naruse et al., 1994), formalin-inactivated virus and ether-split vaccine of influenza virus A/Aichi/68(H3N2) were administered intranasally to the pigs. The peptide vac-cines contained single or double sets of the peptide sequence of hemagglutinin 127-133 of influenza virus A/Aichi/2/68(H3N2) inserted into the H-2 class allele specific amino acid motif of the agretope composed of residues 43-58 of pigeon cytochrome c in the mouse bearing A^(k) or A^(b). After 4 times immuniza- tion, pigs were challenged with 10^(4-5) PFU of virus intranasally. Intranasal immunization of the pigs with inactivated virus vaccine and split virus vaccine induced antibody production against A/Aichi/2/68( H3N2) virus, protecting them from infection. Synthetic peptide vaccine which contains 2 sets of epitope amino acid sequence evoked protective immune response although antibody response was not detected in the pigs. The present results indicated that intranasal route can be applied for inducing not only mucosal immunity but also systemic immunity against influenza virus infection. Based on the present finding we assume that synthetic peptide vaccine prepared according to Cas-sette theory may be applicable to the heterogenous species including human.

Intranasal immunization of pigs against influenza with synthetic peptides based on the cassette theory

임윤규(Y.K. Lim),K. Okazaki,S. Matsuki,K. Ogasawara,H. Kida,이영순(Y.S. Lee) 한국예방수의학회 1998 예방수의학회지 Vol.22 No.3

Synthetic petide vaccines prepared according to the cassette theory (Naruse et al., 1994), formalin-inactivated virus and ether-split vaccine of influenza virus A/Aichi/68 (H3N2) were administered intranasally to the pigs. The peptide vaccines contained single or double sets of the peptide sequence of hemagglutinin 127~133 of influenza virus A/Aichi/2/68(H3N2) inserted into the H-2 class allele specific amino acid motif of the agretope composed of residues 43-58 of pigeon cytochrome c in the mouse bearing Ak or Ab. After 4 times immunization, pigs were challenged with 10⁴⁻⁵ PFU of virus intranasally. Intranasal immunization of the pigs with inactivated virus vaccine and split virus vaccine induced antibody production against A/Aichi/2/68(H3N2) virus, protecting them from infection. Synthetic peptide vaccine which contains 2 sets of epitope amino acid sequence evoked protective immune response although antibody response was not detected in the pigs. The present results indicated that intranasal route can be applied for inducing not only mucosal immunity but also systemic immunity against influenza virus infection. Based on the present finding we assume that synthetic peptide vaccine prepared according to Cassette theory may be applicable to the heterogenous species including human.