Journal of the Japan Institute of Metals and Materials
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
Volume 63 , Issue 2
Showing 1-19 articles out of 19 articles from the selected issue
  • Shinji Tsuji, Toshiaki Furusawa, Tetsuo Saito, Masahiko Kamada
    1999 Volume 63 Issue 2 Pages 145-151
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    The surface modification of SKD61 die steel has been studied by a complex process consisting of, at first, physical vapor deposition of an Al thin film from 0.6 to 4.4 μm (step 1), diffusional dilution of the film into the matrix under vacuum heating at 1298 K for 1.8 ks (step 2), gas quenching (step 3), and plasma-nitriding at 813 K or 853 K for 14.4 ks (step 4) at last.
    The results for the steps from 1 to 3 are as follows. (1) The thickness of the Al-diffused layer increases with the thickness of the Al thin film. The Al content at the most outer surface also increases with the thickness of the Al thin film. (2) The Al-diffused layer shows the hardness of about HV270, and the matrix shows the hardness of about HV610 corresponding to the die steel quenched. (3) The previously reported model for treating multiphase diffusion during the process of homogenization for diffusion couples has been applied to this Al thin film/die steel couple. The numerically calculated profiles of Al content agree well with the experimentally obtained ones.
    The results for the steps from 1 to 4 are as follows. (4) The nitriding zone obtained consists of the Al-diffused nitriding layer, and the nitriding layer of the matrix. The total thickness of both the nitriding layers almost remains constant regardless of the thickness of the Al thin film. (5) The surface hardness of the Al-diffused nitriding steel slightly increases with the thickness of the Al thin film.
    Download PDF (877K)
  • Yasuyuki Fujiwara, Genjiro Motoyasu
    1999 Volume 63 Issue 2 Pages 152-159
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    The OSC apparatus has been constructed and used to examine the feasibility of continuously casting thermal fuse alloy strips. Cast surface quality of the strips, solid-liquid interface position and casting parameters such as casting speed, withdrawal angle and cooling conditions have been studied using Bi-45%Pb, Bi-44%Pb-1%Sn, and Bi-32%Pb-16%Sn alloys (all in mass%). It was confirmed that 2 mm thick and 50 mm wide strips could be produced by the OSC process. In order to maintain stable casting, the solid-liquid interface position must be located no closer than 0.5 mm from the cooling water. It was found that the solid-liquid interface position was closely related to the temperature and amount of cooling water. It was also found that the withdrawal angle of the strip must be kept slightly upward in order to obtain a good surface finish on the strip.
    Download PDF (1147K)
  • Yoshiyasu Itoh, Hironori Suzuki, Hideyasu Andoh
    1999 Volume 63 Issue 2 Pages 160-166
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    The thermal stress characteristics of a zinc-oxide(ZnO) nonlinear element were studied in case of the ZnO element subjected to the partial heating during electrifying. The thermal stress analysis results indicate that the maximum thermal stress at the surface of the disk-shaped ZnO element was reduced when the edge of the element was heated. Moreover, it was made clear that the maximum thermal stress at the surface of the ZnO element was reduced by using a graded heating profile at the edge of the element.
    From the point of view of thermal stress reduction, a functionally graded zinc-oxide(ZnO) nonlinear element with a high surge energy absorption capability was developed for the first time in this study. Namely, graded electric-resistivity at the egde of the disk-shaped ZnO element could be realized by controlling the zinc-oxide grain growth. As a result, high surge energy absorption capability of the functionally graded ZnO element could be confirmed by comparing with a conventional ring heating type element.
    Download PDF (756K)
  • Takashi Yoshida, Tetsuya Nagasaka, Mitsutaka Hino
    1999 Volume 63 Issue 2 Pages 167-173
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    Removal of tramp elements from the remelted scrap is one of the important subjects for the recycling process of base metals such as copper. The present work was aimed to establish fundamental knowledge on the evaporation kinetics of Zn and Pb from inductively stirred liquid copper under reduced pressure. It was found that the evaporation rates of Zn and Pb from liquid copper follow the first-order rate equation with respect to Zn and Pb contents in the metal. The apparent first-order rate constant obtained is in proportional to the reciprocal of the total pressure in the reactor and is independent of the stirring condition of the melt under most of the experimental conditions. The rate of free evaporation calculated by the Hertz-Knudsen-Langmuir equation was found to be much faster than the observed rate. It was, therefore, concluded that the mass transfer in the gas phase would be the rate-limiting step in this case. However, the rate of Zn evaporation at 1693 K tended to be independent of pressure and to approach a constant value at a lower total pressure due to the effect of the mass transfer in the liquid phase. The mass transfer coefficient in the liquid phase was evaluated to be kl=3.0×10−4 m/s. The possibility of the removal of Zn and Pb by evaporation from liquid copper was discussed on the basis of the present experimental results and considerations.
    Download PDF (498K)
  • Takashi Kimura, Yasuhisa Yamamoto, Kenki Hashimoto, Hideaki Moriya
    1999 Volume 63 Issue 2 Pages 174-178
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    After heat-treatment at 1450 K for 24 h, L12-(AlMn)3Ti titanium trialuminides with and without quaternary elements of Zr, Ga, Ag or V were examined by X-ray powder diffraction profile analysis and optical and scanning electron microscopy after hardness tests.
    The minimum load for crack generation during the hardness measurements decreased with the addition of Ag or Zr, however the minimum load increased with addition of V. The residual strain which was induced during milling of the alloy into powder exhibited a positive correlation with the minimum load, i.e., while the alloys with V showed a large residual strain, the alloys with other quaternary elements exhibited a smaller residual strain than that of the ternary L12-type (AlMn)3Ti alloy. The composition dependence of the ternary L12-(AlMn)3Ti single phase alloys was examined by the above mentioned the method. It was shown that the residual strain has the maximum value near the center of Al and Mn-rich corner of the single phase region in isothermal ternary phase diagram at 1425 K.
    Download PDF (608K)
  • Kenichi Ikeda, Koji Morita, Hideharu Nakashima, Hiroshi Abe
    1999 Volume 63 Issue 2 Pages 179-186
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    It has been well known that the boundary fracture strength of molybdenum depends strongly on factors such as grain boundary character and impurity segregation (C and O). In order to clarify the influence of grain boundary geometrical and chemical factors on the boundary fracture strength of molybdenum, bicrystals with a ⟨001⟩ symmetric tilt boundary were prepared in a range of misorientation angles φ from 0° to 90°, and the boundary fracture strength was measured for not-purified and purified specimens by a four-point bending test. In addition, misorientation dependence of the grain boundary energy was measured by a thermal grooving method, and the correlation between the grain-boundary energy and the boundary fracture strength for purified specimens was also investigated. The main results obtained here are as follows.
    (1) The grain-boundary energy depends remarkably on the misorientation angle. Large energy cusps were observed at the near 36.9°/(1\bar30) and 53.1°/(1\bar20)Σ5 coincidence tilt boundaries, and small energy cusp was observed at the near 22.6°/(1\bar50)Σ13 coincidence tilt boundary.
    (2) For the purified specimens, the boundary fracture strength depends on its misorientation angles φ. However, for the not-purified specimen, the misorientation dependence was not observed at large angle boundaries in the range of φ from 16° to 54°.
    (3) The conspicuous difference in the boundary fracture strength between the not-purified and purified specimens was not recognized. It is concluded that the influence of impurity atoms (C and O) on the boundary fracture strength was relatively small for the ⟨001⟩ symmetric tilt boundaries.
    (4) A relatively good correlation was obtained between the grain boundary energy and the boundary fracture strength in the ⟨001⟩ symmetric tilt boundary.
    Download PDF (1431K)
  • Hiroshi Fujiwara, Kei Ameyama
    1999 Volume 63 Issue 2 Pages 187-195
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    The crystallography of grain boundary α(HCP) precipitates nucleated at β(BCC) matrix grain boundaries have been studied with TEM and SEM in a Ti-22 mass%V-4 mass%Al and a Ti-15 mass%V-3 mass%Cr-3 mass%Sn-3 mass%Al alloys. The relative orientation relationship between an α precipitate and adjacent β grains was determined by the Kikuchi pattern analysis. The α precipitate shows a globular allotriomorph or an elongated film morphology. Their shape is an elongated lath with a growth direction lying close to the grain boundary plane. Although intragranular α precipitates have a near-Burgers orientation relationship (OR), the grain boundary α precipitates have a near-Potter or near-{1\bar101}α⁄{110}β OR with respect to at least one of the adjacent β grains. According to the crystallographical feature, they are classified in two types; Type A: a near-{1\bar101}α⁄{110}β OR to one of the β grains and no specific OR to the other one. Type B: a near-{1\bar101}α⁄{110}β OR to both β grains. This {1\bar101}α plane is confirmed to be parallel to one of the twelve {110}β planes in the adjacent β grains, which has smaller angle with the grain boundary plane. Therefore, the variants of an α precipitate at a β grain boundary are selected from 48 (24 possible variants in each β grain for the Potter OR) to 4 at the most, and it reduces in case of good coherency to the opposite β grain.
    Download PDF (1756K)
  • Takanori Nitta, Goroh Itoh
    1999 Volume 63 Issue 2 Pages 196-200
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    Creep behavior of an Al-1 mass%Si-0.5 mass%Cu alloy, which is widely used for connect lines in microelectronic integrated circuits, has been investigated as a function of specimen thickness (t) ranging from 500 to 50 μm and grain size (d). Creep tests were conducted in tension at 200°C in air under constant load with initial stresses σ ranging from 20 to 50 MPa. The steady-state creep rate increased with decreasing specimen thickness and increasing grain size at a constant thickness. As a result, the creep rate increased with decreasing td. From this result, together with the measured stress exponent of creep rate and slip lines observed on the specimen surface, the deformation was concluded to be based on dislocation creep under the tested conditions. Fractography using an SEM showed that all of the specimens failed in a fully transgranular manner irrespective of specimen thickness.
    Download PDF (731K)
  • Atsuo Gyobu, Yoshio Kawamura, Toshio Saburi, Hiroshi Horikawa
    1999 Volume 63 Issue 2 Pages 201-207
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    The martensitic transformation and its associated two-way shape memory effect of sputter-deposited Ni-rich Ti-Ni alloy films were investigated.
    For investigation of the aging (without constraint) effect on the martensitic transformation behavior, deposited amorphous films were crystallized and concurrently aged by holding at various temperatures between 673 and 823 K. The specimens were analyzed with differential scanning calorimetry (DSC) and the following was found: In the Ni-rich side of the Ti-Ni alloy phase diagram, the B2 single phase region widens towards the Ni-rich side with increasing temperature and within this region the B2⇔R transformation temperature decreases with increasing Ni-content. This fact is useful for controlling the B2⇔R transformation temperature of Ni-rich Ti-Ni alloys.
    Then, for investigating the aging effect on the spontaneous shape change associated with the transformations, the amorphous films were crystallized by holding at 973 K followed by aging under constraint (circular shapes) at several different temperatures between 673 and 793 K. On these specimens, observation of spontaneous shape change during cooling and heating was made. The obtained results are the following. The specimens aged under constraint show the two-way shape memory in association with the B2⇒R⇒B19 and the reverse transformations. While the hysteresis of the B2⇒R transformation is less than 2 K, that of the B2⇒R⇒B19 is about 60 K. Aging at 673 K under constraint gives the largest spontaneous shape change both for B2⇒R and B2⇒R⇒B19 transformations.
    Download PDF (886K)
  • Norihiro Itsubo, Ryoichi Yamamoto
    1999 Volume 63 Issue 2 Pages 208-214
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    Life cycle assessment (LCA) is a broad topic that is currently being discussed. However, little is known about the assessment method of environmental impacts expressing a single index, especially in Japan.
    Non ferrous metals are one of the basic materials for industrial products. The establishment of the assessment for these materials is important to improve the quality of LCA for products.
    We have proposed a method of assessment for total impact in Japan, and a case study of LCA is performed concerning the nonferrous metals in this paper. The stages considered in this LCA study are: goal and scope of the inventory analysis and impact assessment. The inventory data include the consumption of raw materials and the emissions through the mining, transport and manufacturing. Resource depletion, global warming, acidification, eutrophication and air pollution have been considered as impact categories.
    The main results of this study are summarized as follows,
    (1) The impacts of eutrophication, air pollution and resource depletion are serious for the production of aluminum.
    (2) The stages of the consumption of non oil and that of the production of non oil are serious for the production of zinc, because the large quantity of non oil such as cokes are consumed.
    (3) We have showed that the interpretation will differ if the criteria of materials for assessment are changed from weight (per kg) to tensile strength (per MN).
    Download PDF (784K)
  • Satoshi Itoh, Osamu Inoue, Minoru Isshiki, Tsutomu Yamamura, Takeshi A ...
    1999 Volume 63 Issue 2 Pages 215-220
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    Phase relations in the zinc-iron-sulfur ternary system at 1100 and 1200 K have been determined by electron probe X-ray microanalysis and X-ray diffraction studies of the quenched samples. The results are summarized as follows:
    (1) Phase relations in the Fe-Zn-ZnS-FeS system at 1100 and 1200 K consist of two-condensed-phase fields and three-condensed-phase fields. The most characteristic observation is that the solubility of sulfur in metal coexisting with sulfide is negligibly small, while the sulfur content in sulfide coexisting with metal is less than 50 mol%. Concerning the mutual solid solubilities between FeS and ZnS, the solubility of FeS in ZnS is considerably larger than that of ZnS in FeS, both at 1100 and 1200 K.
    (2) The effect of temperature on the phase relations of Fe-Zn-ZnS-FeS system was studied. The three-condensed-phase field of α-ZnS s.s.+β-ZnS s.s.+Fe was observed at 1200 K, which was not found at the lower temperature 1100 K. The mutual solid solubilities between FeS and ZnS at 1200 K are larger than those at 1100 K.
    (3) Zinc content in the FeS which will form in the new zinc distillation process with environmental consciousness proposed by the authors, is expected to be negligibly small, since the FeS in the FeS+ZnS s.s.+Fe three-condensed-phase field has an almost stoichiometric composition. This is one of the advantages of the process.
    Download PDF (508K)
  • Kazuaki Sanada, Yasuhide Shindo, Hiroyuki Kudo
    1999 Volume 63 Issue 2 Pages 221-229
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    We discuss the cryogenic damage and fracture behaviors of G-11 woven glass-epoxy laminates. In conjunction with the cryogenic fracture toughness test, a two-dimensional finite element analysis was conducted to predict the fracture and deformation for models of the compact tension specimens. Effective elastic moduli were determined under the assumption of uniform strain inside the representative volume element. Hoffman’s criterion was selected as the criterion for damage accumulation induced by fiber breakage and matrix cracking was detected by the maximum strain criterion. The strain energy method was adopted to calculate strain energy release rate which leads to determination of stress intensity factor. In order to verify the model, correlations between experimental and analytical results were made, in terms of the load-displacement response and the extent of damage growth. At room temperature and 77 K, good agreements were found between the calculations and the experimental data. The predictions showed that the fracture behavior was influenced by temperature rises associated with individual damage events at 4 K. An apparent fracture toughness, Ki, was calculated for each specimen using the load, Pi, at which a significant change of slope in the damage zone size versus load curve was observed. The Ki value was independent of notch length but increased with specimen size.
    Download PDF (785K)
  • Katuo Saitou
    1999 Volume 63 Issue 2 Pages 230-236
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    The relation between the generation rate and specific surface area of ultrafine particles (UFPs) was investigated to examine the possibility of particle size control of UFPs produced using the Ar-H2 arc plasma method.
    UFPs of Ni and Cu were produced in an arc with a voltage of 25-40 V, a current of 90-220 A, and an Ar-H2 mixed gas of atmospheric pressure.
    The specific surface area of UFPs, A, decreased with increasing generation rate, Rg, and the relation between those was described with a power law, A=kgRgn. The value of exponent n was 0.55-0.57 with Ni and 0.36 with Cu when UFPs were produced with a constant torch gas flow rate. When the torch gas flow rate was changed from 0 to 20 L/min, the value of n was 0.8-0.9 with Ni and 1.4 with Cu.
    The relation between the generation rate and specific surface area of UFPs was discussed based on the theory of Brownian coagulation and the theoretical value of n was derived as 0.4. The growth of UFPs produced using the arc plasma method is described well with the Brownian coagulation theory because the experimental value of n agrees with the theoretical value under the condition of constant torch gas flow rate. The increase in n when the torch gas flow rate was changed, is described qualitatively as the change of reaction time and generation rate with the change of flow rate.
    The average particle size of UFPs can be controlled by controlling the generation rate or the electric power.
    Download PDF (528K)
  • Shigeyoshi Yoshida, Mitsuharu Sato, Eishu Sugawara, Yutaka Shimada
    1999 Volume 63 Issue 2 Pages 237-242
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    We investigated the frequency characteristics of permeability for an Fe-Si-Al flakes/polymer composite which has dual frequency dispersion in permeability. From the relation of Curie temperature to the powder surface area, it was found that the mother alloy composition changes with progress of attrition to excess Fe, and as a result, magneto-elastic effect seems to give a large influence on the permeability. Moreover, the results of XPS analysis for bulk samples and compositional dependence of Curie temperature suggests that oxidation of Si and Al at the powder surface leads to excess Fe in the total composition of the powder. Based on these findings, a raw material was prepared adjusting the amount of Fe. Consequently, the Fe-Si-Al flakes/polymer composite exhibits excellent EMI suppressing characteristics in a quasi-microwave band.
    Download PDF (471K)
  • Nobuhiro Tsuji, Takeshi Murakami, Yoshihiro Saito
    1999 Volume 63 Issue 2 Pages 243-251
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    In order to obtain the ultra-fine grained bulk materials whose grain size is less than 1 μm, 5182 aluminum alloy was heavily rolled up to 98.3% at elevated temperatures (R.T.-573 K). The strength of the rolled specimens increased with increasing strain and decreasing rolling temperature, and the tensile strength of the specimen 98.3% rolled at R.T. reached to 540 MPa. The elongation of the 98.3% rolled specimens was 6 to 8% independent of the rolling temperature. No ultra-fine grains were observed in the as-rolled specimens. The specimens 98.3% rolled below 473 K showed complicated deformation microstructures and large local misorientations, while the 573 K rolled specimen showed an ordinary cell structure with small misorientation. Although ultra-fine grains did not form in the as-rolled specimens, 473 K annealing produced the ultra-fine grained structure in the specimens 98.3% rolled below 473 K. The mean grain size of the ultra-fine grains was about 600 nm, independent of the rolling temperature. Ultra-fine grains were not formed in the specimen rolled at 573 K. Even after annealing at 473 K for 18 ks, the ultra-fine grains were not coarsened and the sub-micrometer grain size remained. The formation of the ultra-fine grains can be explained by growth-inhibited recrystallization-nucleation, owing to both the homogeneous introduction of a number of potential nuclei with large local misorientations by high straining and the limited diffusion during low temperature annealing. Ultra-fine grained materials annealed at 473 K showed a tensile strength of 380 MPa and an elongation of 20%. The large strength of the ultra-fine grained material is due to grain refinement, because the Hall-Petch relation between the Vickers hardness and the grain size of the materials was observed.
    Download PDF (1679K)
  • Michiko Yoshitake, Kazuhiro Yoshihara
    1999 Volume 63 Issue 2 Pages 252-258
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    The kinetics of the surface composition recovery was studied in the case of Ti segregation on a Nb film which works as a getter material. The surface concentration of Ti is kept constant at 80 at% with Auger electron spectroscopy, and 60 at% with X-ray photoelectron spectroscopy on the Nb film, when Ti segregates on the surface by diffusing through the Nb film from the substrate. The getter function of this material is estimated to be due to both the high sticking coefficient of residual gases to Ti and the high diffusion coefficients of oxygen and carbon in Nb. Therefore, the coexistence of Ti and Nb on the surface seems to be important. The saturation concentration is independent of the heating temperature and film thickness. Even if the Ti segregation layer is sputtered away, Ti is supplied from underneath and the surface composition can be kept constant when the supply rate is equivalent to the removal rate of Ti. Therefore, the surface composition is maintained automatically in this material. The saturation phenomenon is useful for the conventional fabrication of such functional materials. By observing the dynamic equilibrium between the supply rate and the removal rate, the temperature dependence of the supply rate was estimated. To vary the supply rate, the specimen temperature was changed. The sputtering rate was precisely calibrated before the experiment and was varied to control the removal rate. From the behavior of the surface concentration increase upon segregation and of the dynamic equilibrium, a model to analyze the kinetics of diffusion, segregation and dynamic equilibrium is proposed.
    Download PDF (665K)
  • Kazuya Nishi, Tatumi Hirano, Masahiko Arai, Yasuhisa Aono
    1999 Volume 63 Issue 2 Pages 259-268
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    A study has been conducted to examine the formation behavior of mixed oxide phases in some solid solution type Ni-base ODS alloys made by MA using TEM, XRD and DTA technique. The results indicate that the mixed oxied YAlO3 phase, having a hexagonal structure and termed as YAH, formed when heating Ni-20Cr-0.3Al-0.6Y2O3(mass%) alloy up to 1173 K. The nano-electron beam diffraction experiments identified that the mixed oxide was uniform in structural aspect. NiO has a facilitative effect on forming YAH type mixed oxide and the ratio of the Y2O3 to Al2O3 has a profound effect on the crystalline structure type of the mixed oxide. The YAH mixed oxide in Ni-20Cr-0.3Al-0.6Y2O3 was stable to higher temperature than that in Ni-5Al-10Y2O3-NiO alloys. The present study suggests that the formation and the stability of mixed oxides were strongly affected by the components of ODS alloys and the impurity oxygen absorbed in materials.
    Download PDF (1891K)
  • Kazuhiko Sakaki, Yasuo Shimizu, Yoshiaki Gouda
    1999 Volume 63 Issue 2 Pages 269-276
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    The Effect of expansion state of combustion gas jet on high velocity oxygen-fuel thermal spraying process was investigated using a diverging gun nozzle exit by numerical simulation and experiments with spray powder of Ni-17 mass%Cr-6%Al-0.5%Y. Two different nozzle shapes with a constant throat diameter, namely (i) a convergent-barrel type available in the market and (ii) a convergent-barrel-divergent type, were used. The convergent-barrel-divergent nozzles were designed in such a way that the 15 mm divergent part length had a minimum effect, so that only the effect of expansion state of combustion gas jet was investigated. Numerical simulation studies were carried out by assuming the gas flow within the nozzle to be a quasi-one-dimensional isentropic flow of a semi-perfect gas.
    The numerical simulation results showed a decrease in temperature and density and an increase in velocity of the gas with the diverging nozzle exit, but its effect on the spraying particle behavior was very little.
    Experimental results showed that the expansion state of combustion gas jet changed from under-expansion to correct-expansion, to over-expansion with increasing nozzle exit diameter. Among them, the particle velocity at a spray distance of 200 mm reached a maximum with correct-expansion state of the gas jet due to an increased gas jet velocity. This resulted in an increase in the bonding strength of the NiCrAlY coating. However, the effect of the expansion state of the jet on the structure, hardness and degree of oxide content of the coatings was little. Also, the deposition efficiency of the coatings was found to increase with the increase in the nozzle exit diameter.
    Download PDF (876K)
  • Eiichi Sukedai, Hirosato Nishizawa, Masahiko Shimoda, Hatsujiro Hashim ...
    1999 Volume 63 Issue 2 Pages 277-278
    Published: 1999
    Released: April 24, 2008
    JOURNALS FREE ACCESS
    Download PDF (443K)
feedback
Top