1158 results about "Viscoelasticity" patented technology

The magnetic tape device including: a magnetic tape; and a servo head, in which the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the magnetic layer includes a servo pattern, and logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050.

The magnetic tape device includes a TMR head as a servo head; and a magnetic tape which includes a magnetic layer including ferromagnetic hexagonal ferrite powder and a binding agent, and including a servo pattern, an XRD intensity ratio (Int(110)/Int(114)) of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050.

The magnetic tape device including: a magnetic tape including a servo pattern on a magnetic layer; and a TMR head as a servo head, in which a center line average surface roughness Ra measured regarding a surface of the magnetic layer of the magnetic tape is equal to or smaller than 2.0 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and ΔSFD in a longitudinal direction of the magnetic tape calculated by Expression 1: ΔSFD=SFD_{25° C.}−SFD_{−190° C.} is equal to or smaller than 0.50, wherein the SFD_{25° C.} is SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD_{−190° C.} is SFD measured in a longitudinal direction of the magnetic tape at a temperature of −190° C.

The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and ΔSFD in a longitudinal direction of the magnetic tape calculated by Expression 1: ΔSFD=SFD_{25° C.}−SFD_{−190° C.} is equal to or greater than 0.35. In Expression 1, the SFD_{25° C.} is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD_{−190° C.} is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of −190° C.

The magnetic tape includes a non-magnetic support; a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support, in which a thickness of the back coating layer is equal to or smaller than 0.30 μm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the back coating layer is equal to or smaller than 0.060, and a contact angle with respect to 1-bromonaphthalene measured regarding a surface of the back coating layer is 15.0° to 30.0°.

The magnetic tape includes a magnetic layer including ferromagnetic powder, non-magnetic powder, and a binding agent and a back coating layer including non-magnetic powder and a binding agent, in which the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the hack coating layer is equal to or smaller than 0.060.

A novel process which can simply prepare a crosslinked hyaluronic acid gel having a small crosslinking agent content and exhibiting excellent viscoelasticity is provided.

A process for preparing a crosslinked hyaluronic acid gel, comprising stirring and mixing a mixture containing 10 W/V % or more of hyaluronic acid, a crosslinking agent and water under acidic or alkaline condition.

Provided is an electroacoustic converter film including: a polymeric composite piezoelectric body having piezoelectric particles dispersed in a viscoelastic matrix which is formed of a polymer material exhibiting viscoelasticity at ordinary temperatures; thin film electrodes formed on both sides of the polymeric composite piezoelectric body; and protective layers formed on surfaces of the thin film electrodes. The electroacoustic converter film serves as a speaker capable of being integrated with a flexible display without impairing lightweightness or flexibility, and has considerable frequency dispersion in the storage modulus and also has a local maximum of the loss tangent around ordinary temperatures. A flexible display, a vocal cord microphone and a musical instrument sensor, in each of which the electroacoustic converter film is used, are also provided.

The present invention provides a method for measuring the viscosity and/or elasticity of a liquid by which accurate viscoelasticity measurement can be performed on a wide variety of liquids to be tested ranging from low viscosity liquids to high viscosity liquids, and viscosity and/or elasticity can be precisely determined from the viscoelasticity. This method includes: measuring three frequency values that are the resonance frequency value (f0) on the amplitude characteristic curve obtained through the vibration of the liquid tester 1 in the liquid being tested, a low frequency value lower (f1) than the resonance frequency value (f0) on the amplitude characteristic curve, and a high frequency value (f2) higher than the resonance frequency value (f0) on the amplitude characteristic curve; calculating the real part of the impedance of the liquid being tested, using the high frequency value (f2) and the low frequency value (f1); calculating the imaginary part of the impedance of the liquid being tested, using the resonance frequency value (f0); and calculating the viscosity value and/or the elasticity value of the liquid being tested from the real part and the imaginary part of the impedance.

The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which an absolute value ΔN of a difference between a refractive index Nxy measured regarding an in-plane direction of the magnetic layer and a refractive index Nz measured regarding a thickness direction of the magnetic layer is 0.25 to 0.40, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050.