Anomalous flux jump and supercooling phenomenon around the order-disorder transition in MgB₂ single crystals

Chotoku, M.,Nojima, T.,Ochiai, A.,Aoki, H.,Lee, H.G.,Lee, S.I. North-Holland 2009 Physica. C, Superconductivity Vol.469 No.15

We have performed the detailed measurements of temperature dependence of magnetization M(T) on MgB<SUB>2</SUB> single crystals in a wide range of field H using torque magnetometry. In a field region, where the peak effect in M(H) is observed, we find that M(T) of the warming branch increases monotonously with T and exhibits a small step-like increase at T<SUB>1</SUB><SUP>*</SUP>, which is related to the order-disorder transition, while M(T) of the cooling branch, showing the larger values than that in warming branch below T<SUB>1</SUB><SUP>*</SUP>, drops suddenly toward the warming branch at T<SUB>2</SUB><SUP>*</SUP>. We ascribe this anomalous behavior of M(T) of the cooling branch to a supercooling phenomenon of disordered phase, which transforms to the ordered state at T<SUB>2</SUB><SUP>*</SUP>.

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.

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.

Search for charged Higgs bosons in top quark decays

DO Collaboration,Abazov, V.M.,Abbott, B.,Abolins, M.,Acharya, B.S.,Adams, M.,Adams, T.,Aguilo, E.,Ahsan, M.,Alexeev, G.D.,Alkhazov, G.,Alton, A.,Alverson, G.,Alves, G.A.,Ancu, L.S.,Anzelc, M.S.,Aoki, North-Holland Pub. Co 2009 Physics letters: B Vol.682 No.3

We present a search for charged Higgs bosons in top quark decays. We analyze the e+jets, μ+jets, ee, eμ, μμ, τe and τμ final states from top quark pair production events, using data from about 1 fb<SUP>-1</SUP> of integrated luminosity recorded by the DO experiment at the Fermilab Tevatron Collider. We consider different scenarios of possible charged Higgs boson decays, one where the charged Higgs boson decays purely hadronically into a charm and a strange quark, another where it decays into a τ lepton and a τ neutrino and a third one where both decays appear. We extract limits on the branching ratio B(t->H<SUP>+</SUP>b) for all these models. We use two methods, one where the tt@? production cross section is fixed, and one where the cross section is fitted simultaneously with B(t->H<SUP>+</SUP>b). Based on the extracted limits, we exclude regions in the charged Higgs boson mass and tanβ parameter space for different scenarios of the minimal supersymmetric standard model.

Angular decay coefficients of J/ψ mesons at forward rapidity from p+p collisions at s=510 GeV

Adare, A.,Aidala, C.,Ajitanand, N. N.,Akiba, Y.,Akimoto, R.,Alfred, M.,Andrieux, V.,Aoki, K.,Apadula, N.,Aramaki, Y.,Asano, H.,Atomssa, E. T.,Awes, T. C.,Ayuso, C.,Azmoun, B.,Babintsev, V.,Bai, M.,Ban American Physical Society 2017 Physical Review D Vol.95 No.9

<P>We report the first measurement of the full angular distribution for inclusive J/psi -> mu(+)mu(-) decays in p + p collisions at root s = 510 GeV. The measurements are made for J/psi transverse momentum 2 < p(T) < 10 GeV /c and rapidity 1.2 < y < 2.2 in the Helicity, Collins-Soper, and Gottfried-Jackson reference frames. In all frames the polar coefficient lambda theta is strongly negative at low p(T) and becomes close to zero at high p(T), while the azimuthal coefficient lambda phi is close to zero at low p(T), and becomes slightly negative at higher p(T). The frame-independent coefficient lambda is strongly negative at all p(T) in all frames. The data are compared to the theoretical predictions provided by nonrelativistic quantum chromodynamics models.</P>

Nonperturbative-transverse-momentum effects and evolution in dihadron and direct photon-hadron angular correlations in p+p collisions at s=510 GeV

Adare, A.,Aidala, C.,Ajitanand, N. N.,Akiba, Y.,Akimoto, R.,Alexander, J.,Alfred, M.,Andrieux, V.,Aoki, K.,Apadula, N.,Aramaki, Y.,Asano, H.,Atomssa, E. T.,Awes, T. C.,Ayuso, C.,Azmoun, B.,Babintsev, American Physical Society 2017 Physical Review D Vol.95 No.7

<P>Dihadron and isolated direct photon-hadron angular correlations are measured in p + p collisions at root s = 510 GeV. Correlations of charged hadrons of 0.7 < p(T) < 10 GeV/c with pi(0) mesons of 4 < p(T) < 15 GeV/c or isolated direct photons of 7 < p(T) < 15 GeV/c are used to study nonperturbative effects generated by initial-state partonic transverse momentum and final-state transverse momentum from fragmentation. The nonperturbative behavior is characterized by measuring the out-of-plane transverse momentum component p(out) perpendicular to the axis of the trigger particle, which is the high-p(T) direct photon or pi(0). Nonperturbative evolution effects are extracted from Gaussian fits to the away-side inclusive-charged-hadron yields for different trigger-particle transverse momenta (p(T)(trig)). The Gaussian widths and root mean square of p(out) are reported as a function of the interaction hard scale p(T)(trig) to investigate possible transverse-momentum-dependent evolution differences between the pi(0)-h(+/-) and direct photon-h(+/-) correlations and factorization breaking effects. The widths are found to decrease with p(T)(trig) , which indicates that the Collins-Soper-Sterman soft factor is not driving the evolution with the hard scale in nearly back-to-back dihadron and direct photon-hadron production in p + p collisions. This behavior is in contrast to Drell-Yan and semi-inclusive deep-inelastic scattering measurements.</P>

Permanent Magnets Circuit For Collagen Orientation

T.shinohara,T.Saito,D.Saito,M.Kotani,M.Aoki 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Generation of monoclonal antibodies specific for ORF68 of koi herpesvirus

Aoki, T.,Takano, T.,Unajak, S.,Takagi, M.,Kim, Y.R.,Park, S.B.,Kondo, H.,Hirono, I.,Saito-Taki, T.,Hikima, J.i.,Jung, T.S. Pergamon Press 2011 Comparative immunology, microbiology and infectiou Vol.34 No.3

Outbreaks of koi herpesvirus (KHV) infection in carp are still a serious problem worldwide. KHV is closely related to other two cyprinid herpesviruses, pox herpesvirus (CHV) and haematopoietic necrosis herpesvirus (CyHV-2) in goldfish. In this study, two major KHV antigenic proteins (ORF62 and ORF68) were identified by immunoscreening using a KHV-specific polyclonal antibody, and then monoclonal antibodies were generated for immunodiagnostic studies. After screening hybridoma cells, one mAb against ORF68 (mAb-7C6) was obtained but no mAbs against ORF62. mAb-7C6 specifically reacted with a lysate of KHV-infected koi fin cells (KF-1 cells) but not with lysates of CHV- or CyHV-2-infected KF-1 cells in an immuno-blotting analysis. Similar results were shown in the following tests: (1) a indirect fluorescent antibody test using infected KF-1 cells and (2) an immunohistochemical investigation by fast red stain (infected liver) or FITC detection (infected spleen). These results suggested that mAb-7C6 specifically reacts with KHV ORF68 protein.

Analysis of the Two-Dimensional Wall Jet along a Concave Surface

T. Shakouchi,M. Uesugi,T. Aoki 대한기계학회 1994 KSME/JSME THERMAL and FLUID Engineering Conference Vol.1 No.1

Structural identification and seismic performance of brick chimneys, Tokoname, Japan

Aoki, T.,Sabia, D. Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.5

Dynamic and static analyses of existing structures are very important to obtain reliable information relating to actual structural properties. For this purpose a series of material test, dynamic test and static collapse test of the existing two brick chimneys, in Tokoname, are carried out. From the material tests, Young's modulus and compressive strength of the brick used for these chimneys are estimated to be 3200 MPa and 7.5 MPa, respectively. The results of static collapse test of the existing two brick chimneys are discussed in this paper and composed with the results from FEA (Finite Element analysis). From the results of dynamic tests, the fundamental frequencies of Howa and Iwata brick chimneys are estimated to be about 2.69 Hz and 2.93 Hz, respectively. Their natural modes are identified by ARMAV (Autoregressive Moving Average Vectors) model. On the basis of the static and dynamic experimental tests, a numerical model has been prepared. According to the European code (Eurocode n. 8: "Design of structures for earthquake resistance") non-linear static (Pushover) analysis of the two chimneys is carried out and they seem to be vulnerable to earthquakes with 0.25 to 0.35 g.