巻号一覧
24 巻 (1996)
- 4 号 p. 149-
- 3 号 p. 105-
- 2 号 p. 57-
- 1 号 p. 5-
24 巻, 1 号
選択された号の論文の6件中1～6を表示しています
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白崎 芳夫, 立石 哲也, 片桐 祐1996 年 24 巻 1 号 p. 5-9
発行日: 1996/03/15
公開日: 2012/11/20
ジャーナル フリーThe relationship between mechanical properties, density and mineral contents of horse bone were studied. Three kinds of bone samples were used: The first kind of samples were taken from the horses which fractured legs in training or racing (fractured sample). The second ones were taken from legs of horse which were killed by reason of other diseases (non fractured sample) and the third ones were healthy bone (normal sample). The results of the static and dynamic mechanical measurements and of mineral analysis of bone are as follows: 1) There were positive correlations between the dynamic stiffness, fracture load and bone density in normal bone. However, there was no significant correlation between the dynamic stiffness and bone density of the fracture samples. 2) There was significant difference the contents of Mg, Zn, Sb, Sn, Cr, Na, K, between normal and fracture bone. 3) There was a positive correlation between the content of Sr and dynamic stiffness both in the normal and fracture samples.抄録全体を表示PDF形式でダウンロード (640K) -
Fan CHUN, Chen YAOSONG1996 年 24 巻 1 号 p. 11-14
発行日: 1996/03/15
公開日: 2012/11/20
ジャーナル フリーEquations describing the flow of a film of a Bingham fluid on a rotating disk were derived. The equations considered evaporation of a solvent involved in the fluid and the resulting changes in rheological parameters. From those equations, the film thickness distribution in the radial direction was numerically evaluated with the difference method. Two kinds of the thickness distribution were found. (1) For the case of initial yield stress τ0=0.01 and rheological parameter α≥0.1, the thickness h increased with increasing radial coordinate γ. This result agreed with the experimental result for magnetic disks used in electronic computers. (2) For the cases of α=0 and τ0=0.01; 0.1; 0.2, h decreased with increasing γ. This result agreed with the experimental result obtained by Jenekhe and Schuldt.抄録全体を表示PDF形式でダウンロード (418K) -
Shoichiro YANO, Mitsuo KODOMARI1996 年 24 巻 1 号 p. 15-20
発行日: 1996/03/15
公開日: 2012/11/20
ジャーナル フリーHydroxypropyl cellulose (HPC)/silica micro-hybrids with various amounts of nanometer-size silica particles were produced with a sol-gel process, by incorporating HPC with tetraethoxysilane-derived silica. The sorption isotherms of sol-gel-derived silica, HPC, and the HPC/silica micro-hybrids were measured at 30°C. The sol-gel-derived silica was porous and exhibited a 30% water regain (i.e., percent weight increase due to the absorbed water) at 100% relative humidity (RH). The HPC exhibited a sorption isotherm typical of hydrophilic polymers. Water sorption behavior of the HPC/silica micro-hybrids was almost the same as that of HPC. The dynamic viscoelastic properties of HPC and the HPC/silica micro-hybrids were measured as a function of RH at 30°C. The dynamic modulus, G′, of HPC decreased from 600 Mpa at 0% RH to 8 MPa at 80~100% RH, and the peak in the tan δ curve appeared at about 75% RH. This peak was caused by the onset of micro-Brownian motion by the sorbed water. For the HPC/silica micro-hybrids, G′ decreased only slightly as RH increased. This slight decrease may be caused by the strong interaction between the dispersed small silica particles and the HPC matrix, which prevents water-induced softening of the hybrids. In contrast to the HPC/silica micro-hybrids, the HPC composite blended with 20 wt% of unmodified glass beads exhibited the same viscoelastic behavior as HPC, due to the weak interaction between the glass beads and the HPC matrix.抄録全体を表示PDF形式でダウンロード (738K) -
堀之内 京子, 小牧 秀之, 仙名 保1996 年 24 巻 1 号 p. 21-27
発行日: 1996/03/15
公開日: 2012/11/20
ジャーナル フリーAqueous solutions of PVA with their average degree of polymerization(dp)500 and 2240 were prepared, to which 0.9 μm uniform silica microspheres were dispersed. The amount of PVA adsorbed was larger on the molar basis with smaller dp, but indifferent on the weight basis. This indicates the different molecular configuration of adsorbed PVA with different dp. Maximum adsorption was observed at the isoelectric point of silica, i.e., around pH 3, and decreased with increasing pH. A good dispersion on the floc basis was accomplished at pH 3 with PVA concentration above 0.2wt%, irrespective of dp. At pH 11, appreciable coagulation began above 1.0wt% for dp 2240 and 2.0wt% for dp 500. The PVA concentration dependence of the effective solid volume fraction, estimated from steady shear measurement is similar to that of the Bingham yield value for the suspension at pH 3. The concentration dependence was smaller at pH 11. Small but appreciable coagulation was observed at pH 11 under optical microscope with increasing PVA concentration, which is reflected on the Bingham yield value but not on the effective solid volume fraction. This, together with the value of the average occupation of PVA per unit surface are of silica, indicates that the flocculation at pH 11 is due to coacervation mechanism.抄録全体を表示PDF形式でダウンロード (1705K) -
高橋 真一, 祝 隆志, 荻野 一善1996 年 24 巻 1 号 p. 29-35
発行日: 1996/03/15
公開日: 2012/11/20
ジャーナル フリーViscoelastic properties of aqueous solutions of hyaluronic acid extracted from cockscomb, were studied by make use of magnetic rheometer which was constructed by our laboratory under the conditions of: T (period)/s=180~11,520, F0(amplitude of external sinusoidal force)/N=10-7~10-8(10-5N≅1mg·wt), A0(amplitude of oscillation)/m≅10-4, Cp(polymer concentration)/wt%=0.5, and <Mη>=1.99×106. The results were analysed by the mechanical models, and were found to be well explained by applying the 3-element model (Voigt model with Gg(glass modulus) in series) of Gg/Pa>>Ge/Pa=8.78×10-3, η(Pa·s)=1.205×101 from the plot of J1, J2 vs. log10 ωλ; here J* (complex compliance)=J1-i·J2, ω/(rad·s)=2π/T and λ(retardation time)/s≡η/Ge. This result may be attributed to the experimental condition under very low frequency oscillations.抄録全体を表示PDF形式でダウンロード (891K) -
Masaoki TAKAHASHI, Osamu URAKAWA, Nadereh GOLSHAN EBRAHIMI, Takeharu I ...1996 年 24 巻 1 号 p. 37-42
発行日: 1996/03/15
公開日: 2012/11/20
ジャーナル フリーDamping functions are obtained from stress relaxation experiments in shear and equibiaxial extension for polystyrene melts with narrow and broad molecular weight distribution. Uniaxial damping function is determined applying the Wagner-Demarmels method to the stress growth data obtained in uniaxial extensional flow. When the damping function h(I,II) is plotted against βI+(1-β)II with the strain invariants I,II and a parameter β, a universal function is obtained for each polystyrene sample. It is found that another parameter b is necessary to describe contribution of the Cauchy strain tensor in the constitutive equation in order to explain the experimental data obtained in uniaxial and biaxial extensions.
Fitting with the experimental data of damping function h (I,II) is tried using three representative equations, which are proposed by Papanastasiou-Scriven-Macosko (PSM), Luo-Tanner (LT), and Wagner-Demarmels (WD). The LT equation gives good fit with the experimental data. On the other hand, the WD and the PSM equations cannot describe the experimental data.抄録全体を表示PDF形式でダウンロード (801K)
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