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Effect of fine water droplets on the laminar burning velocity of propane/air premixed flame was investigated by using a single jet-plate configuration. For the case without water droplets, the measured laminar burning velocities are in reasonably good agreement with previously reported data and the numerical simulation. The dependence of the burning velocity on the stretch rate for the case without water droplets is positive for all mixtures tested, resulting in the negative Markstein length, which coincides with previous experimental and theoretical studies. Water droplets lower significantly the laminar burning velocity and change its dependence on the stretch rate to negative. This leads to apparent positive Markstein lengths. The positive Markstein length was discussed on the basis of the droplets behavior in the stagnation flow field adopted in the present study. Even if the droplet mass loading was kept constant, the water droplets do not follow the diverting flow field when the stretch rate is high and the droplets accumulation occurs in the stagnation region where the burning velocities were measured. This fact results in the lower burning velocity as compared to that measured for uniformly dispersed water droplets.

Inwardly rectifying potassium (Kir) channel Kir4.1 (also called Kcnj10) is expressed in various cells such as satellite glial cells. It is suggested that these cells would absorb excess accumulated K + from intercellular space which is surrounded by these cell membranes expressing Kir4.1. In the vestibular system, loss of Kir4.1 results in selective degeneration of type I hair cells despite normal development of type II hair cells. The mechanisms underlying this developmental disorder have been unclear, because it was thought that Kir4.1 is only expressed in glial cells throughout the entire nervous system. Here, we show that Kir4.1 is expressed not only in glial cells but also in neurons of the mouse vestibular system. In the vestibular ganglion, Kir4.1 mRNA is transcribed in both satellite cells and neuronal somata, whereas Kir4.1 protein is expressed only in satellite cells. On the other hand, in the vestibular sensory epithelia, Kir4.1 protein is localized at the calyx endings of vestibular afferents, which surround type I hair cells. Kir4.1 protein expression in the vestibular sensory epithelia is detected beginning after birth, and its localization gradually adopts a calyceal shape until type I hair cells are mature. Kir4.1 localized at the calyx endings may play a role in the K + -buffering action of vestibular afferents surrounding type I hair cells.

A three-dimensional (3D) internal structure observation system based on serial sectioning was developed from an ultrasonic elliptical vibration cutting device and an optical microscope combined with a high-precision positioning device. For bearing steel samples, the cutting device created mirrored surfaces suitable for optical metallography, even for long-cutting distances during serial sectioning of these ferrous materials. Serial sectioning progressed automatically by means of numerical control. The system was used to observe inclusions in steel materials on a scale of several tens of micrometers. Three specimens containing inclusions were prepared from bearing steels. These inclusions could be detected as two-dimensional (2D) sectional images with resolution better than 1 mum. A three-dimensional (3D) model of each inclusion was reconstructed from the 2D serial images. The microscopic 3D models had sharp edges and complicated surfaces.

A recombinant form of BCG Tokyo with an Ag85A gene insert was administered once subcutaneously to guinea pigs and its protective efficacy was compared with that of a DNA vaccine encoding Ag85A from Mycobacterium tuberculosis administered twice to guinea pigs by epidermal gene gun bombardment. Vaccination with either the recombinant BCG Tokyo or Ag85A DNA significantly reduced the severity of pulmonary pathology and the number of pulmonary and splenic colony-forming units (cfu) (p

Within the framework of an extended optical model, simultaneous Χ 2 analyses are performed for elastic scattering and fusion cross section data for 6 He+ 2 0 9 Bi, 6 Li+ 2 0 8 Pb, and 9 Be+ 2 0 9 Bi systems, involving loosely bound projectiles, at near-Coulomb-barrier energies to determine the polarization potential decomposed into direct reaction (DR) and fusion parts. We show that both DR and fusion potentials extracted from Χ 2 analyses separately satisfy the dispersion relation and that the expected threshold anomaly appears in the fusion part. The DR potential turns out to be rather a smooth function of the incident energy, and has a magnitude at the strong absorption radius much larger than the fusion potential, explaining why a threshold anomaly has not been seen in optical potentials deduced from the fits to the elastic scattering data without such a decomposition. Using the extracted DR potential, we examine the effects of projectile breakup on fusion cross sections, σ F . The observed suppression of σ F in the above barrier region can be explained in terms of the flux loss due to breakup.

This study was designed to determine the identity of granulomatogenic substances in Mycobacterium bovis BCG Pasteur. When heat-treated BCG Pasteur bacilli were introduced into the lungs of guinea-pigs by an inhalation exposure apparatus, pulmonary granulomas without necrosis developed. Furthermore, when four kinds of mycolates derived from M. tuberculosis Aoyama B strain were introduced into the lungs by the same method, only trehalose 6,6'-dimycolate (TDM) and methyl ketomycolate induced pulmonary granulomas without central necrosis. The pulmonary granulomas consisted of epithelioid macrophages and lymphocytes. When a mixture of TDM and anti-TDM antibody was introduced into the lungs, development of granulomatous lesions was reduced. These data indicate that TDM and methyl ketomycolate are potent granulomatogenic reagents.

A discussion of the proper homogeneous Lorentz transformation operator eL=exp[−ω⋅S−ξ⋅K] is given where eL transforms coordinates of an observer O to those of an observer O′. Two methods of evaluation are presented. The first is based on a dynamical analog. It is shown that the transformation can be evaluated from the set of equations that are identical to the set of equations that determine the four-velocity of a charged particle in response to a combined spatially uniform and temporally constant electric field E and magnetic field B, where E is parallel to ξ and B is antiparallel to ω, and E/B=ξ/ω. The principal difference in the two problems is that in the dynamics problem, the initial conditions for the four-velocity u must satisfy the constraint, uu=1, whereas the inner product of the coordinates acted on by eL can have any real value. In order to evaluate eL, one can then apply the simplifying techniques of transforming to the frame where E is parallel or antiparallel to B, whereupon the transformation eL in this special frame is trivially evaluated. Then we transform back to the original frame. We determine the β and the rotation Ω that results from a successive boost and rotation that the operator eL produces. A second method is based on a direct summation of the power series of the matrix elements of eL that has been used in relativistic quantum theory. The summation is facilitated by observing that the operators J±≡K±iS commute with each other, and can be represented in terms of the Pauli spin matrices. Indeed, we can reduce the Lorentz transformation to the product of spinor operators to give a compact way to compute the elements of the Lorentz operator eL.

Structural and optical studies were made on the (0 0 1)GaAs surfaces nitrided at 700°C for 15 min in the pressure between 0.01 and 0.5 Torr, plasma-assisted NH3 gas atmosphere. Reflection high-energy electron diffraction (RHEED) and PLS results indicated that the surface nitrided in 0.01 Torr NH3 gas consisted of cubic gallium nitride (c-GaN) with epitaxial orientation: (0 0 1), [1 1 0]c-GaN//(0 0 1), [1 1 0]GaAs, showing PL spectrum with sharp, blue emission of λ=440 nm and a broad peak approximately 470 nm at room temperature. The surface nitrided in 0.05 Torr NH3 gas was composed of a mixture of cubic and hexagonal GaN, showing blue photoluminescence (PL) emission with wavelength, approximately 440 nm at room temperature. The surface nitrided in 0.5 Torr NH3 gas consisted of polycrystalline hexagonal GaN, showing blue PL emission with wavelength, approximately 440 nm at room temperature. Results of depth profile of the nitrided surface, by AES with sputtering technique using argon gas, indicated that the nitrided layers varies approximately 50–1000 A in thickness, depending on the NH3 gas pressure, as a GaNAs alloy layer. These results are in reasonable agreement with theoretical prediction on the band-gap energies in GaN–GaAs alloy system.

A two-way coupled mode approach based on an integral equation formalism is applied to sound propagation through internal wave fields defined at the 1999 Shallow Water Acoustics Modeling Workshop. Solutions of the coupled equations are obtained using a powerful approach originally introduced in nuclear theory and also used to solve simple nonseparable problems in underwater acoustics. The basic integral equations are slightly modified to permit a Lanczos expansion to form a solution. The solution of the original set of integral equations is then easily recovered from the solution of the modified equations. Two important aspects of the integral equation method are revealed. First, the Lanczos expansion converges faster than a Born expansion of the original integral equations. Second, even when the Born expansion diverges due to strong mode coupling, the Lanczos expansion converges. It is shown that the internal wave problems examined are essentially one-way propagation problems because one observes good agreement between the coupled mode solutions and those provided by an energy-conserving parabolic equation algorithm. In the Workshop examples, at both 25 and 250 Hz, significantly greater coupling between modes occurs in the linear internal wave field case than the nonlinear soliton case.

To elucidate the genotypic and phenotypic characteristics of autosomal dominant polycystic kidney disease (ADPKD) in Japanese populations, we performed a comprehensive search for mutations in PKD1 and PKD2 in 180 Japanese ADPKD patients from 161 unrelated families. We identified 112 (89 PKD1 and 23 PKD2) mutations within 135 families. Patients with PKD2 mutations account for 23.6% of all Japanese ADPKD families in this study. Seventy-five out of the 112 mutations have not been reported previously. The estimated glomerular filtration rate (eGFR) decline was significantly faster in patients with PKD1 mutations than in those with PKD2 mutations (-3.25 and -2.08 ml min(-1) year(-1) for PKD1 and PKD2, respectively, p 0.01). These results indicate that mutations within PKD1 and PKD2 can be linked to most of the cases of Japanese ADPKD, and the renal function decline was faster in patients with PKD1 mutations than in those with PKD2 mutations also in the Japanese ADPKD. We also found that PKD2 mutations were more frequent in Japanese ADPKD than that in European or American ADPKD.

To gain a better understanding of the pathological role of interferon-gamma (IFN-gamma) in specific granuloma formation, IFN-gamma gene-deficient mice (BALB/c and C57BL/6) were produced. The IFN-gamma gene in embryonic stem (ES) cells was disrupted by inserting the beta-galactosidase gene (lacZ) and the neomycin resistance gene (neo) at the translation initiation site in exon 1 by homologous recombination. Six-week-old IFN-gamma-deficient and wild-type mice were inoculated with 10(3)-10(7) bacilli of various strains of Mycobacterium tuberculosis (Kurono, H37Rv, H37Ra and BCG Pasteur) through their tail veins. The mice were examined 7 weeks later for granuloma formation. The avirulent BCG Pasteur and H37Ra strains (10(3)-10(4) bacilli/ml) induced granulomas in the spleen, liver and lungs of IFN-gamma-deficient mice. The granulomas consisted of epithelioid macrophages and Langhans multinucleate giant cells, but lacked caseous necrosis. The virulent Kurono and H37Rv strains induced disseminated abscesses but not granulomas in various organs of IFN-gamma-deficient mice and Mac-3-positive macrophages were not detected in the abscess lesions. These results suggest that IFN-gamma may be primarily responsible for macrophage activation and that other factor(s) may be involved in the granuloma formation mechanism.

An optimization approach is used to estimate waveguide parameters for selected test cases of the Geoacoustic Benchmark Inversion Workshop held in Vancouver, June 1997. The approach uses multiple acoustic data samples to decouple the original N–dimensional problem into several smaller-dimensional problems. A nonlinear least squares approach is used to estimate parameters in each subset. The estimation of parameters in each subset proceeds until convergence is reached. Predicted values are in good agreement with the true values, which suggests that the decoupling of waveguide parameters allows a nonlinear least squares approach to be an effective tool in the inversion of ocean waveguide parameters.

Zinc oxide nonlinear resistors with double the conventional reference voltage gradient, while improving their protective characteristics and raising discharging capability, were developed and applied to tank-type surge arresters. On the basis of high-performance elements, which provide good protective characteristics, a simulation was performed on the relation between the composition of the raw material acid the current-voltage (I-V) characteristics, consequently achieving a higher reference voltage gradient and an improved I-V nonlinearity. Moreover, the discharging capability was raised by improving the thermal distribution in the element when a current is applied and reducing their pores. This, when applied to surge arresters, permitted the number of elements, with the same diameter as conventional elements, to be halved. As a result, the number of parts, size and weight of the surge arrester were reduced and its structure was simplified. A series of tank-type surge arresters using these elements for 66-550 kV power systems was developed, tested in various ways without problems, and applied in the field.

Fusion cross-section, elastic and 21+1-inelastic scattering cross-sections for the systems28Si +58Ni and28Si +64Ni are calculated at several energies around the Coulomb barrier energies by using a unified coupled-channel approach. The calculations of the scattering and fusion cross-sections are done simultaneously with a single set of optical potential parameters obtained from aΧ2-analysis of the elastic and fusion data. The excitation channels 2+1, 3-1 and 2-neutron transfer are included explicitly in the total wave function of the nuclear system. A comparison of the results is made to corresponding experimental data.

Spin polarization transfer is proven to be very useful in obtaining detailed information of the continuum nuclear responses. The data, taken for the ( p , n ) reactions, have enabled us to separate the response into the spin longitudinal and transverse components. These partial nuclear responses have been successfully used to make critical tests of nuclear structure models. In the present paper, we shall first summarize the results of the data and the theoretical analyses made so far. We shall then discuss information obtainable from the (3 H e, t ) reaction, emphasizing on the differences and similarities in comparison with the ( p , n ) reaction. The results of numerical calculations made for (3 H e, t ) reactions based on the microscopic distorted wave impulse approximation will also be reported.

Using the QCD sum rule approach, we show that the flavor-nonsinglet $H$ dibaryon states with J$^{\pi} = 1^+$, J$^{\pi} = 0^+$, I=1 (27plet) are nearly degenerate with the J$^{\pi} = 0^+$, I=0 singlet $H_0$ dibaryon, which has been predicted to be stable against strong decay, but has not been observed. Our calculation, which does not require an instanton correction, suggests that the $H_0$ is slightly heavier than these flavor-nonsinglet $H$s over a wide range of the parameter space. If the singlet $H_0$ mass lies above the $\Lambda \Lambda$ threshold (2231~MeV), then the strong interaction breakup to $\Lambda \Lambda$ would produce a very broad resonance in the $\Lambda \Lambda$ invariant mass spectrum which would be very difficult to observe. On the other hand, if these flavor-nonsinglet J=0 and 1 $H$ dibaryons are also above the $\Lambda \Lambda$ threshold, but below the $\Xi^0n$ breakup threshold (2254 MeV), then because the direct, strong interaction decay to the $\Lambda \Lambda$ channel is forbidden, these flavor-nonsinglet states might be more amenable to experimental observation. The present results allow a possible reconciliation between the reported observation of $\Lambda \Lambda$ hypernuclei, which argue against a stable $H_0$, and the possible existence of $H$ dibaryons in general., Comment: 10 pages, 2 figures

The damping mechanisms of the {Delta}(1232) resonance in nuclei are studied by analyzing the quasifree decay reactions {sup 12}C({pi}{sup +},{pi}{sup +}p){sup 11}B and {sup 12}C({sup 3}He,t{pi}{sup +}p){sup 11}B and the 2p emission reactions {sup 12}C({pi}{sup +},pp){sup 10}B and {sup 12}C({sup 3}He,tpp){sup 10}B. The coincidence cross sections are calculated within the framework of the isobar-hole model. It is found that the 2p emission process induced by the decay of the {Delta} resonance in the nucleus can be consistently described by a {pi}+{rho}+g{sup {prime}} model for the {Delta}+N{r_arrow}N+N decay interaction. {copyright} {ital 1997} {ital The American Physical Society}

The integrin alpha 4 beta 1 can provide a costimulus to induce IL-2 secretion and IL-2R expression leading to enhanced proliferation of purified, peripheral blood T cells. Similar to expression of IL-2, we demonstrated that recombinant vascular-cell adhesion molecule-1, when co-immobilized with anti-CD3 mAb, significantly enhanced the induction of transcription factors NF-AT, AP-1, and NF-kappa B as determined by electromobility shift assays. alpha 4 beta 1 ligation alone had no effect on transcription factor binding. The requirements for induction of transcription factors reflected the requirements for the secretion of multiple cytokines, including IL-2, TNF-alpha, IFN-gamma, and granulocyte macrophage-CSF. In contrast to freshly isolated T cells, in vitro-cultured T cells did not require costimulation for cytokine secretion in response to anti-CD3 alone. Comparison of the dose response to anti-CD3 stimulation demonstrated that half-maximal induction of IL-2 was achieved using the same dose of anti-CD3 for both freshly isolated and cultured T cells. Furthermore, the dose of OKT3 required to achieve half-maximal activation was the same using PMA or different concentrations of alpha 4 beta 1 ligands. Therefore, costimulation by alpha 4 beta 1 ligands was not due to stabilization of the interaction of the cells with its substrate. We conclude, rather, that alpha 4 beta 1 in freshly isolated T cells delivers a distinct signal that synergizes early with signals initiated by TCR/CD3 ligation to induce DNA binding of multiple transcription factors required for cytokine gene induction.

The first ({ital p},{ital n}) polarization-transfer measurements for delta production on a nuclear target are presented for the {sup 12}C({ital p}{searrow},{ital n}{searrow}) reaction at 0{degree} and 795 MeV. Polarization observables are used to extract the spin-longitudinal, spin-transverse, and spin-independent partial cross sections. In the spin-longitudinal channel, fair agreement is found between experiment and a model which includes a strongly attractive residual interaction. A large unexpected enhancement in the spin-transverse cross section is observed. {copyright} {ital 1996 The American Physical Society.}

The proton escape widths of the isobaric analog state and the Gamow-Teller resonance in {sup 208}Bi are calculated by solving the charge-exchange continuum Tamm-Dancoff equations. For the Gamow-Teller resonance the spreading contribution to the width is taken into account by the imaginary part of the optical potential. The calculated escape widths are in agreement with measurements obtained from a recent {sup 208}Pb({sup 3}He,{ital tp}){sup 208}Bi experiment.

Coupled-channels calculations are performed to predict fusion, elastic scattering, and inelastic scattering cross sections for the [sup 16]O+[sup 152,154]Sm and [sup 16]O+[sup 186]W systems at sub- and near-Coulomb barrier energies, taking into account the lowest rotational states of the target up to [ital I][sup [pi]]=8[sup +] explicitly. It is shown that experimental data of fusion cross sections taken recently with high precision, partial fusion cross sections, and also average spin values of compound nuclei formed after fusion are well reproduced by the calculations using optical potential parameters that can reproduce elastic and inelastic scattering data. The fusion-barrier distribution, defined as the second derivative of the fusion cross section [ital d][sup 2]([ital E][sigma])/[ital dE][sup 2], is also calculated and compared with experimental data. Particular attention is focused on effects of the [ital Y][sub 4] deformation of the target on various physical quantities.

The inclusive and exclusive cross sections of the [sup 40]Ca([sup 3]He,[ital d]) and [sup 40]Ca([sup 3]He,[ital dp]) reactions have been measured at incident energy [ital E][sup 3]He=240 MeV for an excitation energy of the residual nucleus [sup 41]Sc up to [similar to]16 MeV. The measured data are analyzed by means of the breakup-fusion theory. A formulation of the theory is developed for calculation of both exclusive and inclusive cross sections. Elastic breakup, breakup-fusion, and breakup-fusion followed by subsequent decay are taken into account in our theoretical description of the inclusive and exclusive data. The respective roles of the different processes are discussed. It is shown that the calculations reproduce very well the main features of the observed cross sections.

The Δ excitations in nuclei induced by pion and photon scattering and by intermediate energy charge exchange reactions are analyzed within the isobar-hole model. The results of the various reactions are compared to each other and their similarities and differences due to the reaction kinematics and the spin-structure of the probes are discussed. The various decay modes of the Δ resonance in the medium are investigated. Of special interest is the coherent pion decay of the Δ which is studied by means of the exclusive reaction 12 C( 3 He, tπ + ) 12 C(g.s) , by elastic pion scattering, and by pion photoproduction. It turns out that the coherent pion decay of the 12 C( 3 He, tπ + ) 12 C(g.s.) reaction is intimately related to elastic pion scattering. Most interestingly, both the peak energy and the magnitude of the coherent pion production cross section depend very sensitively on the strength of the Δ-hole residual interaction. The observed energy shift is directly proportional to the nuclear density ϱ. This shows that the coherent pions propagate through the nuclear interior. The coherent pion cross section can be used to determine the Landau-Migdal parameter g ′ ΔΔ . An energy shift is also observed in the 2p decay channel while such a shift is not observed in the p π + decay.

The [Delta] excitations in nuclei induced by pion and photon scattering are analyzed within the isobar-hole model. The results are compared to those of intermediate energy charge exchange reactions. The similarities and differences between the various probes due to their kinematics and spin-structure are discussed. It is shown that the experimental cross sections for pion and photon induced reactions as well as for the inclusive charge exchange reactions can be consistently described within the isobar-hole model. Of special interest is the coherent pion decay of the [Delta] resonance which is studied by means of the exclusive reaction [sup 12]C([sup 3]He,[ital t][pi][sup +])[sup 12]C(g.s.), by elastic pion scattering, and by pion photoproduction. It turns out that the coherent pion decay of the [sup 12]C([sup 3]He,[ital t][pi][sup +])[sup 12]C(g.s.) reaction is intimately related to elastic pion scattering. Most interestingly, both the peak energy and the magnitude of the coherent pion production cross section depend very sensitively on the strength of the [Delta]-hole residual interaction. The observed energy shift is directly proportional to the nuclear density [rho]. This shows that the coherent pions propagate through the nuclear interior. The coherent pion cross section can be used to determine the Landau-Migdal parameter [ital g][submore » [Delta][Delta]][sup [prime]].« less

The proton escape widths of the Gamow-Teller resonance and the isobaric analog state in 208 Bi are calculated by solving the charge-exchange continuum Tamm-Dancoff equations. For the Gamow-Teller resonance the spreading contribution to the width is taken into account by the imaginary part of the optical potential. The calculated escape widths are in agreement with measurements obtained from a recent 208 Pb ( 3 He ,tp) 208 Bi experiment.

Water resources for water supply of Tokyo depend mainly on surface water from many dams and rivers in the Kanto province and ground water in a part of Tokyo. But because of an increase in water demand and a reduction in water resource development, a water shortage has occurred every few years. The Tokyo Metropolitan Government (TMG) announced a new policy to conserve limited water resources and has implemented several measures to promote the consumers' consciousness for water conservation, use of reclaimed water and development of water-saving appliances. With water for miscellaneous use (=nonpotable use), the TMG has encouraged “reuse of treated wastewater”, “use of industrial water for miscellaneous use”, and “use of rainwater”. According to three types of reclaimed water systems - individual building, limited area, and broad area recycling systems - the TMG established a guideline for the water for miscellaneous use. This paper describes the background of the issue, contents of the guideline, and results of the promotion and theme in the future.

T cells recognize tumor-associated antigens under the condition of lymphopenia-induced homeostatic proliferation (HP); however, HP-driven antitumor responses gradually decay in association with tumor growth. Type I interferon (IFN) has important roles in regulating the innate and adaptive immune system. In this study we examined whether a tumor-specific immune response induced by IFN-α could enhance and sustain HP-induced antitumor immunity. An intratumoral IFN-α gene transfer resulted in marked tumor suppression when administered in the early period of syngeneic hematopoietic stem cell transplantation (synHSCT), and was evident even in distant tumors that were not transduced with the IFN-α vector. The intratumoral delivery of the IFN-α gene promoted the maturation of CD11c(+) cells in the tumors and effectively augmented the antigen-presentation capacity of the cells. An analysis of the cytokine profile showed that the CD11c(+) cells in the treated tumors secreted a large amount of immune-stimulatory cytokines including interleukin (IL)-6. The CD11c(+) cells rescued effector T-cell proliferation from regulatory T-cell-mediated suppression, and IL-6 may have a dominant role in this phenomenon. The intratumoral IFN-α gene transfer creates an environment strongly supporting the enhancement of antitumor immunity in reconstituted lymphopenic recipients through the induction of tumor-specific immunity and suppression of immunotolerance.

A formulation of the continuum random-phase approximation (CRPA) nuclear response with a velocity-dependent residual interaction of the Skyrme type is presented. The inhomogeneous coupled-channel integro-differential equations obtained are modified so as to use the Lanczos method, by means of which they can be solved relatively easy. The CRPA method here presented can give information on the direct and statistical decay as well as their partial ph components. We apply the method to a detailed analysis of photonuclear reactions in 4He, 16O and 40Ca in the giant-dipole-resonance region. Total cross sections, contributions from direct emission and spreading as well as partial γp and γn emission ph components are calculated and compared to experimental data.

The 40Ca(6Li, d)44Ti reaction at the 60.1 MeV incident energy is measured using the Q3D spectrometer. The angular distributions of 30 levels from 4° to 42° and in the excitation energy range up to 9.5 MeV are obtained. The angular distributions are analyzed using the breakup-fusion model.

The Δ excitations in nuclei induced by intermediate energy charge exchange reactions are analyzed within the isobar-hole model. It is shown that the isovector spin-longitudinal () response function of nuclei in the Δ resonance region is shifted down in energy by ~ 60 MeV in comparison to the spin-transverse () response function. This shift is consistent with pion and photon total cross section data. The coherent pion decay of the Δ resonance is studied by means of the 12 C(p, nπ +)12 C(g.s.)and 12 C(γ, π 0)12 C(g.s.) coincidence reactions. The calculations show that the coherent pion production cross section provides a unique signature on the nuclear pionic mode. The coherent pions in the charge exchange reactions have a peak energy of E π = 250 MeV and a strongly forward peaked angular distribution. The coherent pions from the pion-photoproduction reaction have a peak energy of E π = 220 MeV and an angular distribution which peaks near θ π = 30°.

The coherent pion production in the charge exchange reaction 12 C (p,nπ + ) 12 C ( g . s .) is used to study the isovector spin- longitudinal ( S·q T ) response of nuclei in the Δ resonance region. It is shown that the pion production cross section provides unique signature of the nuclear pionic mode. The coherent pions have a peak energy of Eπ=250 MeV and a strongly forward peaked angular distribution.

Based on the extended optical model with the double folding potential, in which the polarization potential is decomposed into direct reaction (DR) and fusion parts, simultaneous ${\ensuremath{\chi}}^{2}$ analyses are performed of elastic scattering and fusion cross-section data for the $^{9}\mathrm{Be}+^{28}\mathrm{Si}$, $^{144}\mathrm{Sm}$, and $^{208}\mathrm{Pb}$ systems at near-Coulomb-barrier energies. The polarization potentials thus determined are found to reveal an interesting target mass number dependence reflecting the experimental observation that the fusion cross section becomes larger than the DR cross section as the target changes from $^{208}\mathrm{Pb}$ to $^{28}\mathrm{Si}$.

A three-dimensional (3D) internal structure observation system based on serial sectioning was developed from an ultrasonic elliptical vibration cutting device and an optical microscope combined with a high-precision positioning device. For bearing steel samples, the cutting device created mirrored surfaces suitable for optical metallography, even for long-cutting distances during serial sectioning of these ferrous materials. Serial sectioning progressed automatically by means of numerical control. The system was used to observe inclusions in steel materials on a scale of several tens of micrometers. Three specimens containing inclusions were prepared from bearing steels. These inclusions could be detected as two-dimensional (2D) sectional images with resolution better than 1 mum. A three-dimensional (3D) model of each inclusion was reconstructed from the 2D serial images. The microscopic 3D models had sharp edges and complicated surfaces.

A FORTRAN program NLOM for nonlocal optical model calculations is described. It is based on a method recently developed by Kim and Udagawa, which utilizes the Lanczos technique for solving integral equations derived from the nonlocal Schrodinger equation.

Analyses of data of the {sup 40}Ca({sup 6}Li,{ital d}){sup 44}Ti reactions at incident energies of 28 and 50 MeV have been carried out within the framework of the breakup-fusion approach, which allows us to treat reactions to both bound and unbound final states on a single footing. The resultant spectroscopic information, particularly concerning the {alpha}-cluster structure of {sup 44}Ti, is presented and discussed.

In the extrusion of tubes from titanium alloys surface defects are often observed. These defects are related to process variables such as tool geometry and temperature, initial billet temperature, characteristics of the extrusion press and lubrication. Often it is difficult to establish optimum process variables for extruding defect-free tubes through experimentation, because this is costly and time consuming. The application of FEM to study metal flow in extrusion is also difficult because large deformations are present and the FEM mesh distorts very rapidly, requiring numerous remeshings. To overcome this problem and to improve the efficiency of applying FEM to investigate tube extrusion, an automated remeshing procedure was developed. Through this procedure the FEM mesh was automatically updated and the FEM code alpid , version 2.3, was used successfully to simulate metal flow under three different extrusion conditions. The results of these simulations helped to understand the formation of surface defects in the internal surface of extruded tubes. This information is expected to assist in improving tube extrusion operations.

Calculations are made of direct reaction and fusion parts of the dynamical polarization potential obtained by reducing a large scale coupled-channels problem to that of a single-channel optical potential model. Aspects of the physical nature of the resultant potential are investigated, such as the nonlocality of the potential, and the region where absorption due to direct reactions and fusion mainly occurs.

A formulation of the continuum random-phase approximation (CRPA) equations with a finite-range particle-hole (ph) interaction is presented. The resulting equations can be applied to the calculation of RPA wave functions not only in the continuum, but also in the bound region. These CRPA equations, which are inhomogeneous coupled-channel integro-differential equations with a large dimension and thus difficult to solve, are modified so that the Lanczos method can be applied to solve them relatively easily. As examples we apply our method to the 3 − bound state and the giant quadrupole resonance (GQR) in 16 O and 40 Ca. A nuclear matter G -matrix is used for the ph interaction. Since treating the continuum exactly introduces in effect an infinitely large shell-model space, the ph correlations induced by the G -matrix interaction are too strong, not only for the bound collective states but also for collective states in the continuum. Renormalizing the exchange ph matrix elements allows one to fit the experimental data in both the bound and continuum part of the excitation spectrum in a consistent manner. For both the low-lying and continuum region the ring approximation is shown to be a good approximation for dealing with the exchange part of the ph matrix elements that are responsible for the ground-state correlations.

The delta (Δ) excitations in nuclei induced by intermediate energy charge exchange reactions are analysed within the iobar-hole model. It is found that the Δ-hole correlations mediated by the energy-dependent π-exchange interaction of the spin longitudinal channel shifts the Δ-peak position downwards in energy by ∼ 30 MeV. The origin of this shift is explained in detail.

When considering subbarrier fusion of two heavy-ions, it is important to take into account the specific nature of the two ions involved. Indeed, the significance has been pointed out of using the coupled-channels (CC) descriptions~ I, 2 or of including in the calculation the fusion taking place in the nucleon-transfer channels. 3 Many earlier approaches, however, used potentials that were quite different from the "scattering potential", i.e., from the optical potential deduced by fitting the (elastic) scattering. We recently proposed 4 a new approach to calculate subbarrier fusion cross sections, based on the "standard" direct reaction theory (DRT), i.e., sticking to the use of the "scattering potential". The essence of this approach was to let W F, defined as a part of W, be responsible for fusion, where W is the imaginary part of the optical potential. As is well known, the total reaction cross section in DRT is written as

Simultaneous {chi}{sup 2} analyses are performed for elastic scattering and fusion cross section data for the {sup 12}C+{sup 208}Pb system at near-Coulomb-barrier energies by using the extended optical model approach in which the polarization potential is decomposed into direct reaction (DR) and fusion parts. Use is made of the double folding potential as a bare potential. It is found that the experimental elastic scattering and fusion data are well reproduced without introducing any normalization factor for the double folding potential and also that both DR and fusion parts of the polarization potential determined from the {chi}{sup 2} analyses satisfy separately the dispersion relation. Furthermore, it is shown that the imaginary parts of both DR and fusion potentials at the strong absorption radius change very rapidly, which results in a typical threshold anomaly in the total imaginary potential as observed with tightly bound projectiles such as {alpha}-particle and {sup 16}O.

Linear momentum transfers in α-induced reactions with 20 MeV per nucleon are calculated by considering all important direct and incomplete fusion mechanisms along with complete fusion. The calculated results agree very well with the experimental data. Calculated total inelastic cross section and various incomplete fusion cross sections (including the stripping reactions to bound discrete states) also agree well with the experimental data.

It has been known for sometime that the peak position of the Δ (1232) -resonance spectra observed in the (p,n)-1, (3He,t)-2, and (\(\vec d\),2p)-3charge-exchange reactions at intermediate energies is systematically shifted downward for a target with A ≥ 12 as compared to the peak position for a proton target. In contrast to this, in the case of γ-absorption4 and inelastic electron scattering experiments,5 the Δ-peak does not show such a pronounced displacement. The electromagnetic probes excite the Δ transversely, i.e., by the transition operator \(\vec S \times \vec q\vec T\) (\(\vec S\) and \(\vec T\) are the spin and isospin transition operators, respectively.), while the hadronic probes measure both the transverse (TR) and the longitudinal (LO) spin-isospin response. It has thus been speculated that the shift of the Δ-peak would be due to a nuclear medium effect in the isovector spin LO(\(\vec S \cdot \vec q\vec T\))channel.6,7 That is, if the delta particle-nucleon hole (ΔN -1) interaction becomes strongly attractive at large momentum transfers \(\left| {\vec q} \right| \approx 1 - 2\) fm-1 in this channel, then this attraction might lead to a lowering of the Δ mass produced in the target. Along this line of reasoning, no shift of the Δ-peak position is to be observed with the electromagnetic probes. Recently, we have made some realistic calculations of the spectra of the 12C(p,n) and (3He,t) reactions at the Δ-excitation region, and succeeded to show that the LO response is indeed shifted downwards in energy and that this shift is caused by the energy-dependent π-exchange interaction.8

A newly developed technique has been used to probe a previously inaccessible region of the continuum in the at channels of 7 Li breakup reactions. This was used to investigate reactions of 63 MeV 7 Li with 58 Ni, 120 Sn, 144 Sm, and 208 Pb targets. Breakup pairs of α-particles and tritons emitted within a finite opening angle were analyzed according to their magnetic rigidity using a K = 150 Enge split-pole spectrograph. The αt coincidences were taken with two single-wire proportional counters mounted at different positions along the focal plane of the spectrograph. The large energy acceptance ( E max / E min ≈ 8) of the spectrograph is crucial to the present coincidence measurements involving two particles with different q / m values. Very small relative energy components were studied without any detection threshold. A pronounced bump was observed immediately above the αt particle threshold. No strong indication of the post Coulomb acceleration was observed. The excitation of the continuum states as well as the 7 − 2 state in 7 Li is discussed in terms of the distorted-wave Born approximation. The astrophysical implications of the data are also discussed regarding the Coulomb excitation of the continuum. The present technique offers the promise of very high sensitivity at small relative energies if it were applied in conjunction with ray-tracing, a thin target, and a dispersion-matched beam.

A search is made for a polarization potential fully satisfying the dispersion relation, by carrying out simultaneous χ2-analyses of elastic scattering and fusion data for the 16 O + 208 Pb system near the Coulomb barrier energy. The imaginary part, W, of the potential is assumed to consist of a volume-type fusion and a surface-derivative-type direct reaction potential, while the real part has the corresponding polarization parts along with an energy-independent bare potential. Characteristic features of the potential thus obtained are discussed.