Journal of the Japan Institute of Metals and Materials
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
Volume 30 , Issue 9
Showing 1-20 articles out of 20 articles from the selected issue
  • Eiji Isono, Tatsuru Ueno
    1966 Volume 30 Issue 9 Pages 801-805
    Published: 1966
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The knowledge of the relation between ultrasonic Lamb wave attenuation and temperature in steel is necessary for the flaw inspection by Lamb waves at high temperatures. This relation have been examined using 1.9 to 3.2 mm thick steel sheets and a commercial ultrasonic flaw detector, in which 0.5 to 10 Mc frequencies are used, in temperature range from room temperature to 500°C. The results are as follow:
    (1) Rimmed sheets show a high attenuation peak. The peak temperatures are 270° to 280°C at 2.25 Mc, 250°C at 1 Mc and 310°C at 5 Mc.
    (2) Killed sheets also show an attenuation peak but the amount is much smaller.
    (3) Stainless steel and ultra-high tensile steel sheets have no attenuation peaks but show a different dependence of attenuation on temperature.
    From the internal friction of the sheets, it has been confirmed that the above attenuation peak is a Snoek peak, mainly due to carbon atoms dissolved in steel.
    Therefore mentioned results should be taken into consideration for the flaw inspection of sheets using ultrasonic Lamb waves at high temperature.
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  • Keisuke Ikeda, Osamu Izumi, Eihachiro Tanaka
    1966 Volume 30 Issue 9 Pages 806-810
    Published: 1966
    Released: April 04, 2008
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    By compression tests, the deformation charactristics, structure and mechanism of crack origination during deformation were studied on S.A.P. containing 1.2∼15.5 wt%Al2O3. Proof stress (0.2% off set) and flow stress remarkably increase with the increment of the oxide content. However, the above tendency was not conspicuous over about 8 wt%Al2O3, due to the nonuniform distribution of oxide particles and the existence of voids. The strength of other aluminum alloys, Y-alloy and Lo-Ex, decreases abruptly at 200° and 300°C, while the strength of S.A.P. gradually decreases with the rise of the testing temperature.
    Cracks are produced by compression at room temperature and at high temperatures above 400°C. The cracks formed at room temperature are shear cracks due to the stress concentration at voids. On the other hand, cracks formed at high temperatures are tension cracks parallel to the compression axis, and they may be due to the gas produced by decomposition of the oxide.
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  • Keisuke Ikeda, Osamu Izumi, Eihachiro Tanaka
    1966 Volume 30 Issue 9 Pages 811-814
    Published: 1966
    Released: April 04, 2008
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    The effect of distributed particles on the recrystallization behaviors of five kinds of cold-rolled S.A.P. containing 1.2∼12.7 wt%Al2O3 was investigated. The recrystallization temperature of the cold-rolled S.A.P. with a low oxide content is nearly identical to that of pure aluminum. But the recrystallization temperature rises with increase in oxide content, and alloys with a high oxide content above 8 wt% do not recrystallize up to a temperature near the melting point of matrix. On the other hand, the hot-extruded S.A.P. do not recrystallize by annealing up to 500°C for 1 hr.
    Recrystallized grains of the cold-rolled S.A.P. with a low oxide content are extremely coarsened and grown two-dimensionally, but the alloys with a high oxide content show fine grains after recrystallization at high temperatures.
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  • Naokatsu Tsuda
    1966 Volume 30 Issue 9 Pages 815-819
    Published: 1966
    Released: April 04, 2008
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    For the purpose of obtaining lead sheath with excellent mechanical properties, which is used for the power cable, a study was made of the effects of cadmium addition on the tensile strength, proof stress, elongation, and fatigue strength of the extruded Pb-0.06%Cu alloy, to which was added 0.08% to 0.83%Cd. The precipitate observed in the Pb-0.06%Cu-Cd alloy was subjected to identification by an X-ray microanalyzer. The results obtained are as follows:
    (1) The tensile strength of the alloy improved along with increase in the quantity of cadmium added; but such improvement became slow when the addition of cadmium reached 0.83%. The proof stress increased, but the elongation decreased, along with increase in cadmium content.
    (2) The fatigue strength increased along with increase in cadmium addition up to 0.33%, but there was no further increase even when more cadmium was added.
    (3) The precipitate of Pb-0.06%Cu-Cd alloy was found to contain Cu and Cd.
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  • Tadami Taoka, Kazuo Ogasa, Eiichi Furubayashi, Shin Takeuchi
    1966 Volume 30 Issue 9 Pages 820-826
    Published: 1966
    Released: April 04, 2008
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    A goniomicroscope, which permits measurements of directions of normals to facets with an area as small as 10×10 μ2, was applied to the determination of orientation of small grains of several metals and alloys and to crystallographic studies of surface planes of iron and zinc oxide whiskers and of twin bands on 3% silicon-iron.
    In order to determine orientations of small grains of metals, some new etchants were developed in order to produce uniformly distributed micropits, which consisted of some crystallographic facets with low indices. By measuring the normals to the facets of the micropits, the crystallographic orientation of the small region where the pits were embeded could be determined within the accuracy of 1 degree.
    Shapes of whiskers having prismatic flat surfaces were determined by the goniomicroscope and the orientations of the whisker crystals were also determined by an X-ray Laue technique. Side faces of square prismatic iron whiskers were found to be {100} planes and those of hexagonal prismatic zinc oxide whiskers were {1\bar100} planes.
    Surface serrations of twin bands on 3% silicon-iron were found to be composed of two sets of small facets; B1, B2 and C1, C2. Intersections of the specimen surface and one set of the small facets were parallel to {110} planes and intersections of twin band surface and another set of the small facets were parallel to {110} planes in the twin crystal.
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  • Iwao Muchi, Junichiro Yagi, Kenji Tamura, Akira Moriyama
    1966 Volume 30 Issue 9 Pages 826-831
    Published: 1966
    Released: April 04, 2008
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    Indirect reduction of iron ores, gasification of cokes, direct reduction of molten wustite, reduction of silica in slag and desulfurization of pig iron have been analyzed and these rates of reactions are determined as the function of properties of materials in the furnace and the operating conditions. For the indirect reduction of iron ores, Eq. (6) of the over-all rate of reduction is obtained, assuming that the diffusion through the gaseous film around the iron ore, the intraparticle diffusion and the chemical reaction proceed in a serial process. Rate determining steps are examined and the results are illustrated in Figs. 3 and 4. For gasification of cokes, using effectiveness factor Ef, the over-all rate of reaction is derived as Eq. (23). Eq. (32) for the rate of reduction of molten wustite is determined, assuming that the reaction is of the second order with respect to wustite in slag. Reduction of silica is analyzed in the upper zone from the tuyere level, and the rate of this reaction is given as Eq. (39). For the desulfurization of pig iron in the hearth, apparent velosity constants are determined as Eq. (45) and (46), considering the reaction between the slag layer and the molten iron flowing through it and the reaction between the layer surface and the iron bath, respectively.
    These equations of the rate of reaction will be applied to a mathematical model of the blast furnace in the forthcoming reports.
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  • Hakaru Masumoto, Takeo Kobayashi, Kiyoshi Watanabe
    1966 Volume 30 Issue 9 Pages 832-836
    Published: 1966
    Released: April 04, 2008
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    The present investigators previously found a new magnet alloy “Malcolloy” having a high coercive force in the system of cobalt and aluminum and then conducted studies on the influence of the additions of nickel, molybdenum, titanium and vanadium on their magnetic properties, the highest coercive force obtained being 1450∼1600 Oe. Further, they have investigated the influence of the addition of chromium on the properties of Co-Al alloys and have discovered that the coercive force and the maximum energy product of Co-Al alloys were increased generally by the addition of chromium. Thus, an alloy with the composition of 82.11%Co, 14.12%Al and 3.77%Cr shows a coercive force of 1450 Oe, a residual magnetic flux density of 3150 G and a maximum energy product of 1.42×106 G·Oe when tempered at 550°C for 15 hours after water-quenching from 1375°C, and the highest value of maximum energy product is 2.40×106 G·Oe. These alloys consist of many ferromagnetic elongated particles of about 300 Å in diameter which are dispersed in the matrix of nearly non-magnetic β′ phase. Consequently, it may be concluded that the high coercivity of these alloys is mainly caused by the existence of the small particles composed of a single magnetic domain.
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  • Hakaru Masumoto, Takeo Kobayashi, Y\={u}etsu Murakami
    1966 Volume 30 Issue 9 Pages 837-840
    Published: 1966
    Released: April 04, 2008
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    The present investigators previously found a new magnetic alloy “Nimalloy” having a high permeability in the system of nickel and manganese and then made a study of the effect of iron additions on its magnetic properties. The highest values of initial and maximum permeabilities obtained were 39,200 and 213,000 respectively. The present investigation of the influence of the addition of vanadium on the magnetic properties of “Nimalloy” has revealed that the initial and maximum permeabilities of the alloy are increased generally by the addition of a small amount of vanadium. The alloy containing 19.92% Manganese and 2.16% vanadium shows the initial permeability of 22,000 and the maximum permeability of 169,500, the magnetic hysteresis loss of 4.47 erg/cm3/cycle, the coercive force of 0.0095 Oe maximum induction of 2,000 G and the specific resistance of 55.3 μΩ-cm at 20°C after being cooled at a rate of 240°C/hr from 900°C and then reheated at 420°C for 95 hrs.
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  • Takeaki Kikuchi, Toshio Kurosawa, Testuo Yagihashi
    1966 Volume 30 Issue 9 Pages 840-846
    Published: 1966
    Released: April 04, 2008
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    The thermal behavoirs of the Japanese colloidal earth available as the source material in the direct reduction of aluminium were investigated by means of thermo-balance, differential thermal analysis, X-ray analysis, infrared spectrum and neuclear magnetic resonance.
    The colloidal earth was amorphous by X-ray analysis and contained 15∼30 percent moisture.
    The greater part of the moisture was removed at 100°∼250°C and the moisture was found to be physically combined water located in cavities of particles or lattice layers. The residual moisture was clearly detected by infrared spectum even at 900°C and was inferred to be the water combined on the surface of lattice layers and crystal water.
    With the advance of heating and dehydration, the infrared absorption spectrum of O-Al-OH binding was weakened, and the strengthening of Si-O and the formation of Si-O-Al binding were observed at temperatures over 500°C.
    This result shows the preparatory process involving separating of SiO2 and formation of mullite from the pseudo-metakaoline structure, and this was detected by differential thermal analysis by a exthothermal peak at about 950°C.
    Moreovers, this exthothermal peak was derived from the nucleation of mullite, and clear needle-like crystals of mullite were observed over 1200°C.
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  • Hiroshi Ishizuka, Keizo Onishi
    1966 Volume 30 Issue 9 Pages 846-852
    Published: 1966
    Released: April 04, 2008
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    In recent years, the problem of sulfide corrosion cracking of weldable high-strength structural steel in the oil refining field has been regarded as important. In this experiment, using the bent-beam system, the susceptibility to sulfide corrosion cracking in each grade steel was investigated. It appeared that susceptibility to sulfide corrosion cracking was mainly related to material strength, and that the rate of crack initiation depended on the H2S concentration in a corrosion medium and the stress applied to the material. The correlation between the lower limit of H2S concentration and the lower limit of stress for crack initiation was investigated in each kind of the steel. Types of cracking observed in the specimen were corrosion cracks on the specimen surface, hydrogen blister, and hydrogen cracks.
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  • Hiroshi Ishizuka, Keizo Onishi
    1966 Volume 30 Issue 9 Pages 852-857
    Published: 1966
    Released: April 04, 2008
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    Although the mechanism of sulfide corrosion cracking of weldable high strength structural steels is not fully known, this cracking must be related to the hydrogen absorption and embrittlement of the steels during sulfide corrosion. From this point of view, the amount of hydrogen absorption and the degree of embrittlement on each high-strength steel by sulfide corrosion was examined, and an investigation was made on relationship between sulfide corrosion cracking and hydrogen embrittlement. The results obtained were as follows:
    (1) The amount of hydrogen absorption in the steels by sulfide corrosion is related to the steel strength, and it decreases as the strength increases.
    (2) Each steel is embrittled by sulfide corrosion. The degree of embrittlement which is closely related to the sulfide corrosion cracking susceptibility is high in the steel susceptible to the cracking but low in the steel with high resistibility.
    (3) Recovery of ductility by aging of embrittled material depends on the aging time and temperature. This shows that the embrittlement of the steels by sulfide corrosion is closely related to a diffusion process of hydrogen in steels.
    (4) The cracking phenomenon during sulfide corrosion is associated with a delayed failure by hydrogen.
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  • Zenzo Henmi, Takeshi Nagai
    1966 Volume 30 Issue 9 Pages 857-862
    Published: 1966
    Released: April 04, 2008
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    In a previous paper, the authors reported the results investigated by the transmission electron microscope on the precipitation in Cu-2%Be alloy. In this work, the process of precipitation in Cu-Be 25 alloy was examined by the transmission electron microscop.
    The aging sequence of Cu-Be 25 alloy is the same as Cu-2%Be alloy, α→G.P. zone→γ′→γ in grain and α→γ at grain boundary, but the aging sequence of Cu-Be 25 alloy is slower than Cu-2%Be alloy. The detail of aging sequence is different, for example, the products of the grain boundary reaction has internal stress or the overaged Cu-Be 25 alloy has an anomalous electron diffraction pattern.
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  • Genjiro Mima, Masaharu Hasegawa, Kiyotaka Matsukawa
    1966 Volume 30 Issue 9 Pages 862-868
    Published: 1966
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The measurement of changes in the reflectivity of a pure copper to the 0.6 μ monochromatic light during the oxidation process in air and the microstructure changes of the specimen surfaces were examined in order to study the oxidation phenomenon of copper. By the heat treatment from room temperature with a constant rate of 1° to 3.6°C/min, the reflectivity of copper decreased with temperature and lowered by about 80% when heated up to 200°C. The reflectivity restored about 90% of the pre-heating value by heating up to 250°C, but it again decreased rapidly by about 60% by heating up to 300°C. In the isothermal heating over the temperature range of 150°∼250°C the changes in reflectivity were similar to those observed in the constant rate heat treatment namely, with the heating time the reflectivity at first decreased to a minimum value and then attained a maximum value, after which it again decreased rapidly. Although a distinct microstructure was revealed on the specimen surfaces by thermal etching at the initial stage of oxidation, the structure turned into an indistinct brown structure when the reflectivity reached a maximum, and then exfoliation of the oxide film occurred with further oxidation. The non-monotonous change of the reflectivity of copper in the oxidation process can be attributed to the interferrence of the reflected rays at the air-copper oxide interface and the oxide-copper interface, and when the mean thickness of the oxide film on the polycrystalline copper specimens reached abut 1,000 and 1,500 Å, the reflectivity to the 0.6 μ monochromatic light attained the minimum and maximum values. The activation energy of the oxidation of copper was estimated by this experiment to be about 12,000 cal/mol at the initial stage when the reflectivity changed non-monotonously and about 19,000 cal/mol at the intermediate stage when the reflectivity decreased rapidly.
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  • Hideo Sugawara, Saburo Shimodaira
    1966 Volume 30 Issue 9 Pages 869-873
    Published: 1966
    Released: April 04, 2008
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    The corrosion protection of aluminium brass by ferrous or ferric ion has been investigated in 3% NaCl aqueous solutions. Ferrous-sulphate, ferrous-chloride, ferric-sulphate or ferric-chloride were used. The concentration of ferrous or ferric ion was measured by the o-phenanthoroline method. The substances of surface films formed on aluminium brass were identified by means of diffuse reflection spectra and electron diffraction. The results obtained were as follows.
    (1) By the addition of 10∼100 ppm ferrous ion or 10 ppm ferric ion, the corrosion rates were markedly decreased and the concentration of chloride or sulphate ion had no appreciable effects on the corrosion rates. (2) In the case of containing hydrogen sulphide, the ferrous ion produced some non-stoichiometric compound and the corrosion rates of aluminium brass were considerably increased. (3) The surface films formed on aluminium brass consisted mainly of γ-FeOOH and the corrosion protictive action by the ferrous or ferric ion was due to the absorbed γ-FeOOH.
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  • Toshio Sawada, Sakae Kato
    1966 Volume 30 Issue 9 Pages 874-879
    Published: 1966
    Released: April 04, 2008
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    Gold exhibits a red-brown color, which is fitted to the spectrophotometric purpose of its stannous method, by the reaction with stannous chloride under the experimental condition. It has been known that the spectrophotometric determination of gold can be made by making use of this color reaction, although the color varies depending not only on the concentration of stannous chloride but also on the concentration of hydrochloric acid. That is, when 1∼3 mL of 1 M stannous chloride solution is added to 50 mL of 1∼2 N hydrochloric acid, the color reaction which developed up to 3.3 mg of gold is reliable as a function of gold concentration at a wavelength of 500 mμ, irrespective of the concentration of these reagents. Another factor affecting the accuracy of the color-system was the effect of temperature. At 20°∼30°C the intensity of the color increases during the first few minutes and then remains constant for 5 to 90 min. An effective application of the reaction has been established for the spectrophotometric determination of gold in titanium-gold alloys after dissolution in hydrofluoric and nitric acid. The color reaction developed by this method follows Beer’s law, with a molecular extinction coefficient of 2800. All the elements which are usually contained in titanium alloys cause no interferences except for palladium, platinum, molybdenum, vanadium and silver. The content of matrix metal titanium up to 1 g is permissable when urea is added. By the newly established spectrophotometric method, the gold contents in synthetic titanium-gold alloys and titanium alloys containing 0.01 to 5% gold have been measured in high accuracy.
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  • Susumu Yoshida, Norio Nagata
    1966 Volume 30 Issue 9 Pages 879-885
    Published: 1966
    Released: April 04, 2008
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    The dynamic deformation behaviour of aluminium single crystals (99.99% purity) was investigated by a compression test at room temperature, using a bar-bar type impulsive loading apparatus. The dynamic stress-strain relation at strain rates of the order of 102 sec−1 shows a similar orientation dependence to the static one. Crystals properly oriented for single slip under dynamic deformation show higher critical resolved shear stresses and more extensive easy glide regions than those under static deformation. The values of the critical resolved shear stresses for dynamic deformation range from 250 g/mm2 to 500 g/mm2. The rate of work hardening of stage II is shown to be higher for dynamic deformation than for static one. Microscopic observations on slip markings reveal that the dynamically deformed specimens show slip bands which are higher in density and weaker in contrast than the statically deformed ones.
    On the basis of the above results, it is pointed out that for the easy glide region of deformation at high strain rates the frictional stress acting on moving dislocations becomes too large to be negligible and contributes greatly to the critical resolved shear stress and the flow stress.
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  • Hakaru Masumoto, Hideo Saitô, Michio Kikuchi
    1966 Volume 30 Issue 9 Pages 885-888
    Published: 1966
    Released: April 04, 2008
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    The present investigators have succeeded for the first time to prepare long bar specimens of single crystals of close packed hexagonal cobalt, about 10 cm long. And with these single crystals, the anisotropy of electrical resistivity and the magneto resistance effect up to the field of 1000 Oe were measured. It was found that the specific electrical resistivity was the largest in the c-axis direction and the smallest in the direction perpendicular to the axis; the values of 10.280 μΩ-cm and 5.544 μΩ-cm were obtained, respectively, and the values of ΔRR were about 0.4 percent in the c-axis direction and about 0.2 percent in the direction perpendicular to the axis.
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  • Goro Ito, Tadao Ishihara, Yoshihiko Shimizu
    1966 Volume 30 Issue 9 Pages 888-893
    Published: 1966
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The comparison of stress corrosion cracking behaviors of four types of commercial austenitic stainless steel in high temperature water was studied.
    Tests were made at the temperature of 300° and 350°C for 300 hr in an autoclave containing the testing water with 100∼800 ppm of chloride ion added as NaCl.
    The amount of dissolved oxygen in water was controlled with or without deaeration at the temperatures of 105° and 150°C, respectively.
    The results were summarized as follows:
    (1) Neither of the steels showed no stress corrosion cracking provided that the concentration of dissolved oxygen in the testing water did not exceed 0.2 ppm, but cracking was observed on all the types of stainless steel in the water with a concentration of dissolved oxygen higher than 0.3 ppm.
    (2) Among the solution treated steels, the type SUS 32 was most resistant, and the susceptibility of other types were almost the same.
    (3) Sensitizing heat treatment markedly increased the susceptibility of cracking for all the types of steels.
    (4) The cracking was transgranular in the solution treated steels independently of the difference in composition, but the intergranular cracking was also observed in the sensitized type SUS 27 and 32 steels.
    (5) From the observation on the pitting corrosion formed on the test pieces and also from the metallographic inspection of pits and cracks, it appears that pitting is the cause of initiation of cracking.
    (6) The results of cracking tests in a boiling 42%MgCl2 aqueous solution did not agree with those in high temperature water in regard to the process of initiation or path of cracking, and also the difference in susceptibility of cracking for the four types of steel was noticed between the two testing methods.
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  • Mitsuru Tanino, Tokuhiko Nishida, Kôichi Aoki
    1966 Volume 30 Issue 9 Pages 894-895
    Published: 1966
    Released: April 04, 2008
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  • Tamotsu Nishina, Moritaka Syozi
    1966 Volume 30 Issue 9 Pages 896-897
    Published: 1966
    Released: April 04, 2008
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