Poly(vinyl alcohol) cast gels (PVA gels) were prepared at different gelation temperatures, Tgel, and the swelling ratio mechanical properties characterized by equilibrium weight measurement, a uniaxial loading test, tearing force cyclic compression test room temperature. The results showed that decreased both breaking stress energy increased with an increase in Tgel. deformation of 50% reduction its original size monotonically, while hysteresis loss was not affected To understand these...

High-pressure Brillouin spectra of crystalline hydrogen sulfide (H(2)S) have been measured at up to 7 gigapascals room temperature. The best fit the angular dependence acoustic velocities between experimental values and calculations based on Every's expression for elastic waves an arbitrary direction yielded orientation H(2)S cubic crystal grown in diamond-anvil high-pressure cell. In situ determinations sound velocities, as a function pressure, could be made any direction, refractive index,...

Poly (vinyl alcohol) (PVA) hydrogel with high water content is the candidate material for artificial cartilage. PVA hydrogels prepared by freeze-thawing (FT) method (PVA-FT gel), cast-drying (CD) (PVA-CD gel) and hybrid of FT CD (PVA-hybrid were developed their friction wear behaviors evaluated. Sliding pairs a cobalt-chromium-molybdenum alloy or alumina ceramic ball plate tested in reciprocating test. Ultra-pure simulated synovial fluid used as lubricants PVA-FT gel showed severe ultra-pure...

High-pressure Brillouin spectroscopy has been used to determine acoustic velocities in any direction, refractive index, adiabatic elastic constants, and bulk modulus of ${\mathrm{H}}_{2}$O ${\mathrm{D}}_{2}$O ices at 300 K pressures between 1.05 2.1 GPa for tetragonal ice VI above up 8 cubic VII. Typical values constants are ${\mathit{C}}_{11}$=32.8, ${\mathit{C}}_{12}$=11.8, ${\mathit{C}}_{13}$=14.7, ${\mathit{C}}_{33}$=27.8, ${\mathit{C}}_{44}$=6.3, ${\mathit{C}}_{66}$=5.9 the pressure...

Infrared spectra at high pressure and room temperature reveal that molecular dissociation metallization occur in solid ${\mathrm{H}}_{2}\mathrm{S}$ near 46 96 GPa, respectively. The disappearance of SH stretching bands the $2300--2500{\mathrm{cm}}^{\ensuremath{-}1}$ region simultaneous appearance a lattice vibrational mode around $1300{\mathrm{cm}}^{\ensuremath{-}1}$ signal dissociation. At higher pressures, low-energy electronic absorption band develops eventually extends throughout...

The Raman spectra of hydrogen-bonded molecular solid H2S have been measured up to 23 GPa at 300 K in a gasketed diamond-anvil cell. In the orientationally disordered phase I between 0.47 and 11 GPa, symmetric stretching mode ν1 shows red-shift frequency (dν1/dP=−10.1 cm−1/GPa ) dramatic broadening with pressure. At about antisymmetric band ν3 appears higher-frequency side ν1. Near this same pressure five low-frequency vibrational modes also appear show pressure-sensitive features. These...

Even though microgels are used in a wide variety of applications, determining their mechanical properties has been elusive because the difficulties analysis. In this study, we investigated surface elasticity spherical microgel gelatin prepared inside lipid droplet by using micropipet aspiration. We found that gelation microdroplet covered with membranes increased Young's modulus E toward plateau value E* along decrease gel size. case 5.0 wt % gelled microsized space, for small R ≤ 50 μm was...

The acoustic-phonon velocities of a single crystal BaTi${\mathrm{O}}_{3}$ have been measured as function pressure up to 8 GPa, including the transition ${p}_{c}=2.35$ by means Brillouin scattering technique. Only one elastic eigenmode shows an anomalous decrease on approaching ${p}_{c}$ and anisotropy increases. anomaly cubic is interpreted well introducing new tensorial order parameter which describes anisotropy. cubic-to-tetragonal phase in shown be triggered fluctuation anisotropy, not...

Abstract In general, cells move on a substrate through extension and contraction of the cell body. Though movement should be explained by taking into account effect such shape fluctuations, past approaches to formulate cell-crawling have not sufficiently quantified relationship between (velocity trajectory) fluctuations based experimental data regarding actual shaping dynamics. To clarify this relationship, we experimentally characterized in terms especially contraction, using an...

With Raman spectroscopy, the pressure-temperature (P-T) phase diagram for solid hydrogen sulfide has been determined at high pressures up to about 20 GPa and low temperatures down 30 K. The triple point between II, III, IV phases of ${\mathrm{H}}_{2}$S exists 3.1 153 Phase is stable in wide P-T region, simple comparison with that ${\mathrm{H}}_{2}$O ice, which many high-pressure phases.

By high-pressure Brillouin spectroscopy, sound velocities for all directions and three elastic constants of cubic ice VII have been determined up to 8 GPa at room temperature, with in situ identification the orientation single crystal grown a diamond-anvil cell. We found unusual result that Cauchy relation ( ${C}_{12}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}C}_{44}$) holds every pressure VII. This suggests interactions between atoms can be described by central forces....

Physically cross-linked PVA gels (freeze-thawed gel and cast-dried gel) are used as biocompatible materials since special chemicals were not in their preparation. Cast-dried therefore promising candidate for artificial cartilage because of excellent frictional property. In this study, three types gels-freeze-thawed gels, hybrid which laminated consisting both layer freeze-thawed prepared analyzed. The behaviors these hydrogels examined reciprocating test. Further, the effects sterilization...

An x-ray-powder-diffraction experiment on solid ${\mathrm{H}}_{2}\mathrm{S}$ was performed with a diamond-anvil cell and an image plate to determine the unknown structures of phases ${\mathrm{I}}^{\ensuremath{'}}$ IV up 25 GPa at room temperature. The were found be cubic ${T}^{4}{\ensuremath{-}P2}_{1}3$ tetragonal ${D}_{4h}^{20}{\ensuremath{-}I4}_{1}/acd,$ respectively, by Rietveld method. Both derived from fcc structure phase I slight atomic displacements sulfur. Likely positions hydrogen...

The sensitization reactions to purified cinnamic aldehyde and its chemically related substances were investigated using the maximization test on guinea pigs. Mutual cross-sensitivities also examined. Cinnamic was found be most potent sensitizer in this series, a strong cross-sensitizer. From chemical structures of these substances, following speculations made. There tendency that as number hydrocarbons alkyl groups replacing alpha-hydrogen molecule increased, rate reaction declined....

The direction-dependent acoustic velocities, refractive index, adiabatic elastic constants, bulk modulus, and anisotropy in liquid solid krypton have been determined under pressures up to 8 GPa by Brillouin spectroscopy, with situ identification of the single-crystal orientation a diamond-anvil cell. Typical values three constants for fcc crystalline are ${C}_{11}=40.7,$ ${C}_{12}=28.7,$ ${C}_{44}=15.8\mathrm{GPa}$ at 6 room temperature. These results contrast fundamentally inequality...

Acoustic velocities, refractive index, and elastic constants of liquid solid ${\mathrm{CO}}_{2}$ have been determined at pressures up to 6 GPa by applying Brillouin spectroscopy developed for condensed gases in a diamond-anvil high-pressure cell. The analyses the angular dependence acoustic velocities show that remains cubic (dry ice) phase I throughout range pressure from freezing (0.6 GPa) 300 K.

Abstract The first study of pressure dependence Brillouin scattering spectra in SrTiO3 up to 9 GPa is reported. longitudinal and transverse acoustic velocities increase with increasing 6 GPa, show an anomaly near 6.5 associated a cubic-to-tetragonal structural phase transition. transition good agreement the value expected from other data, showing validity mean field approximation-in SrTiO3. elastic constants determined by means pressure-dependent density derived cubic phase. mode Grüneisen...

The Raman spectra of hydrogen-bonded crystalline HCONH2 and HCOND2 have been measured up to 10 GPa at 300 K in a gasketed diamond anvil cell. frequencies the in-plane intermolecular stretching mode which characterizes hydrogen bond along zig–zag chain increase with increasing pressure slope (dν/dP) 11.1 cm−1/GPa, its becomes steeper, 19.2 about 5.0 (=Pc). intramolecular ND2 decrease all range except around Pc where they show an 20 cm−1. It turns out from these results that (1) (deuteron)...

Hydrogen-bonded molecular solid ${\mathrm{H}}_{2}$S has been studied up to 42 GPa search for a high-pressure phase by x-ray diffraction at room temperature. New peaks appeared above 27 GPa, which indicates transition from IV another phase, V. A color change thin yellow black was observed this transition, large decrease of the energy gap IV-V transition. Phase V may be metallic in region 27-42 GPa.

Elution of polymers from physically cross-linked poly(vinyl alcohol) (PVA) gel in its swollen state was investigated by measuring quantitatively the total carbon outer water using a Total Organic Carbon (TOC) analyzer. The dried samples, prepared cast-drying method, were immersed pure under different conditions. As result, elution detected, and it gradually stopped limited amount water. On other hand, polymer successively released exchanging repeatedly at long intervals (more than 21 h),...

Swelling and elution properties of physically crosslinked poly(vinyl alcohol) (PVA) cast gels depend on the network structure PVA crosslink, which is characterized by size, number, distribution microcrystallites. Therefore, swelling ratios can be manipulated adept control conditions adopted for preparation gels. Among various factors that influence formation microcrystallites, temperature relative humidity at gelation play an important role. In addition, size gel also a key factor determines...

Poly(vinyl alcohol) (PVA) is a biocompatible polymer with low toxicity. It possible to prepare physically cross-linked PVA gels having hydrogen bonds without using cross-linking agent. The newly reported cast-drying (CD) on freeze-thawed (FT) hybrid gel has an excellent friction property, which expected be applied as candidate material for artificial cartilage. Gamma ray sterilization clinical applications usually causes additional chemical and changes physical properties of gels. In this...