A methods and systems for determining a change in condition of a rock bolt. Some methods may comprise, at a first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a first time of flight for each of the shear and longitudinal waves, at a second point in time after the first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a second time of flight for each of the shear and longitudinal waves, and using the relative changes of the first and second time of flights, determining the change in condition of the rock bolt section.

A high-pressure true triaxial test apparatus with capacity of low-frequency disturbance and high-speed impact includes static and dynamic loading frames, four static loading actuators, two dynamic loading actuators and an SHPB mechanism, wherein all actuators are connected with a hydraulic station system; a hollow way is formed in the axial center of each piston shaft of the dynamic loading actuators, a dynamic pressure sensor adopting a hollow ring structure is mounted at the end part of each piston shaft, and the SHPB mechanism applies a high-speed impact load on a rock sample through the dynamic pressure sensors respectively; and the dynamic loading actuators adopt a static pressure oilway balance support sealing manner and are connected with the hydraulic station system, each oilway is provided with an energy accumulator, and flow is increased by the servo valves to drive pistons to perform dynamic response.

A pair of jigs has the same mass and a weight is adjusted in consideration of a test piece shape so that stress of a center portion of a test piece becomes a desired value. That is, the jig serves as a weight adjustment tool for adjusting a resonance frequency and stress of the test piece. The upper and lower jigs are attached to both ends of the test piece S so that the center of gravity of the upper jig and the center of gravity of the lower jig are located on a perpendicular line passing through the center portion of the test piece.

A system and method for evaluating a bond is provided. The system uses an underwater spark discharge to generate a compression wave in a first vessel containing a liquid. The system further includes a second vessel in which a vacuum is pulled to hold the first vessel against a bonded structure being inspected. The compression wave is directed to propagate from the liquid into the bonded structure to apply a known force to the bond being inspected.

A method and apparatus for measuring a dynamic tensile stress and/or tensile strain response of a material such as an elastic material and/or a ductile material. The apparatus may include a striker bar, a stretcher bar, and a drive assembly configured to propel the striker bar toward the stretcher bar. The apparatus may further include a stationary specimen mount and a movable specimen mount that receive a test sample. The striker bar and the stretcher bar of the apparatus may provide a continuous stress on the test sample and an accurate tensile stress/strain measurement.

An integrated controller for an environmental testing system simultaneously controls and synchronizes vibration, temperature, and humidity in an environment test chamber over a specified reliability test duration, and performs condition-based measurement and processing of vibration data obtained from the environment test chamber for one or more specified trigger conditions. The controller executes a combined run schedule using a single internal clock and a hardware processor, to generate parameter control commands for the environment test chamber that remain synchronized to the single internal clock over the duration of a test, even one that lasts for weeks or months. This permits multi-variate processing of measured instantaneous values of temperature, humidity, and vibration to obtain, e.g., condition-dependent vibration power spectra and averages for available conditions of temperature, humidity, or both.

A high-pressure true triaxial test apparatus with capacity of low-frequency disturbance and high-speed impact includes static and dynamic loading frames, four static loading actuators, two dynamic loading actuators and an SHPB mechanism, wherein all actuators are connected with a hydraulic station system; a hollow way is formed in the axial center of each piston shaft of the dynamic loading actuators, a dynamic pressure sensor adopting a hollow ring structure is mounted at the end part of each piston shaft, and the SHPB mechanism applies a high-speed impact load on a rock sample through the dynamic pressure sensors respectively; and the dynamic loading actuators adopt a static pressure oilway balance support sealing manner and are connected with the hydraulic station system, each oilway is provided with an energy accumulator, and flow is increased by the servo valves to drive pistons to perform dynamic response.

In a defect detection device (10), an input receiver (161) receives an input, by a user, of information concerning the kind and size of a defect expected to be present in or on a test object. An exciter (11, 12) induces an elastic wave in the test object, with the frequency of the elastic wave being variable. A measurer (15) optically measures a vibration state of the surface of the test object caused by the elastic wave. A wavelength determiner (164) determines the wavelength of the elastic wave induced in the test object, based on the vibration state obtained by the measurer. A frequency selector (165) selects an appropriate frequency from a plurality of frequencies, based on the kind and size of the expected defect as well as the wavelength acquired for each of the plurality of frequencies by the wavelength determiner by varying the frequency of the elastic wave.

There are provided, inter alia, methods for reacting an enzyme and its substrate, methods for purifying a protein and an enzyme reactor and its use thereof.

A method of laser bond inspection is provided. The method includes applying a thermochromatic energy-absorbing material to an inspection site of a test article. The method includes delivering a first amount of energy to the inspection site using a laser. The first amount of energy generates stresses in the test article. The method includes absorbing the first amount of energy into the thermochromatic energy-absorbing material to produce an observable thermal response that correlates to the first amount of energy.