2102 results about "Longitudinal wave" patented technology

A BAW resonator includes a piezoelectric layer, a first electrode, a second electrode, a substrate, and an acoustic reflector disposed between the substrate and the second electrode. The acoustic reflector has a plurality of layers. A performance of the acoustic reflector is determined by its reflectivity for a longitudinal wave existing in the BAW resonator at the resonance frequency of the BAW resonator and by its reflectivity for a shear wave existing in the BAW resonator at the resonance frequency of the BAW resonator. The layers of the acoustic reflector and layers disposed between the acoustic reflector and the piezoelectric layer are selected, with reference to their number, material, and thickness, such that the transmissivity for the longitudinal wave and the transmissivity for the shear wave in the area of the resonance frequency is smaller than −10 dB.

According to the method longitudinal waves are generated in a transducer used only as a transmitter connected from outside to a conduit. These waves are transmitted along two diagonal paths through the streaming medium in an upstream and a downstream direction, and received by two transducers used only as receivers which are located in a diagonal upstream and downstream position and on an opposite side relative to the transducer used as a transmitter, also connected to the conduit. A transit time value of the waves between the transducer used as a transmitter and each of the transducers used as receivers is determined. A difference value on the basis of the determined transit time values is generated and the flow parameters are determined on the basis of said difference value. This measuring method is highly independent of the propagation velocity of the wave in the medium streaming in the conduit therefore also independent of the temperature and humidity of a gaseous medium. An apparatus and a conduit for use in the apparatus for performing the method is also suggested. The conduit used in the apparatus comprises a first location for receiving a transmitter in a middle region of the measuring area and two second locations for receiving receivers in a border region of the measuring area opposite to the first location. The wall of the conduit is dimensioned so that the longitudinal waves can pass through it with minimal loss and maximum efficiency. The inner wall of the conduit forms a uniform and continuos surface for the transmission of the longitudinal waves between the transmitter and the receivers and for blocking the passage of any organic or inorganic material. In medical applications the apparatus and its housing is configured to receive, hold and release a sterile conduit.

The invention provides a method and a device for synchronous measurements on dynamic and static elastic parameters of rocks by using a rock triaxial anti-compression testing device. The method comprises: sealing a test rock sample in a triaxial autoclave filled with hydraulic oil, applying an oil pressure by an axial pressure control system, applying a confining pressure by a confining pressure control system, and applying a pore pressure by a pore pressure control system; acquiring propagation speeds of longitudinal waves and transverse waves in the test rock sample by a computer acquisition and control system, and calculating the dynamic Young modulus and the dynamic Poisson ratio according to the propagation speeds; and acquiring deformation parameters of the test rock sample during a loading process by the computer acquisition and control system, and calculating the static Young modulus and the static Poisson ratio according to the deformation parameters. The method and the device can ensure validity and accuracy of hydrocarbon reservoir rock mechanical parameter measurements in thousands of meters deep underground and under the conditions of complex confining pressure, high temperature, high pore pressure and polyphase fluid.

NDT inspection of an austenitic weld between two CRA Clad pipes using a phased ultrasonic transducer array system is described. The method may be performed during laying of gas/oil fatigue sensitive pipelines, for example, at sea. Two types of UT inspection may be generated simultaneously by a Phased Array on each side (Upstream and Downstream) of a girth weld. Firstly, mode converted longitudinal waves are used. These waves have properties that they propagate well. Shear waves are also used. The combination of these two ultrasonic waves, with the addition of surface waves, enables 100% of the girth weld to be inspected to the standard required in fatigue sensitive welds, such as Steel Catenary Risers. Shear waves and compression waves are emitted substantially contemporaneously. Defects may be detected and measured using time of flight information and amplitudes of radiation detected on reflection and on diffraction from the defect.

A communication device includes a communication circuit unit that processes a high frequency signal which transmits data, a high frequency signal transmission path that is connected to the communication circuit unit, a high frequency coupler that receives the high frequency signal and radiates an induction electric field signal of a longitudinal wave, and an antenna that receives the high frequency signal and radiates a radiation electromagnetic field or an electric wave signal of a transverse wave.

A transcutaneous energy transfer system with subcutaneous non coupled coils is used to transmit power and signals to an implanted biological support device or sensor, such as a flow sensor for measuring relatively low flow rates, such as hydrocephalic shunt flow. The flow sensor is configured to convert a shear wave generated by a transducer to a longitudinal wave at the interface of a signal pathway and the flow, wherein the longitudinal wave travels parallel to the flow and exits a flow channel to convert to a shear wave which intersects a second transducer. The transcutaneous energy transfer employs a pair of inductive coupling coils, wherein the coils are disposed in zero coupling orientation which can include a perpendicular orientation of corresponding coil axes.

The invention discloses an elastic reverse time migration imaging method by combining seismic multi-component and belongs to the field of exploration geophysics. The method comprises the following steps: directly inputting seismic multi-component data; without performing the wave field separation on the input data, extrapolating forwards at inverse time based on an elastic wave equation; building an underground elastic vector seismic wave field by combining with multi-component; acquiring four elastic wave imaging results having specific physical significance, such as longitudinal wave, transverse wave, transition longitudinal wave and transition transverse wave, by applying an elastic wave cross-correlation imaging condition of lighting compensation; and suppressing the low wave number noise in the elastic reverse time migration by performing low-pass angle filtering, thereby acquiring an imaging result of final elastic wave migration. By directly inputting the seismic multi-component data and building the underground elastic vector seismic wave field by combining with multi-component, the method can be used for accurately imaging for complex earth medium.

The invention relates to a reservoir shear wave velocity prediction method based on rock physics. The method comprises the steps that (1) supposing that the bulk modulus, the shear modulus and the density of a destination interval mineral are unknown constants, the error between a longitudinal wave velocity and a measured longitudinal wave velocity is acquired according to equation modeling, and the error between the acquired density and the measured density is calculated; (2) according to the minimum error criterion, the bulk modulus, the shear modulus and the density of a mineral component are inverted through a genetic algorithm; (3) and the shear wave velocity is calculated. According to the step (1), supposing that the elastic modulus of each rock component is an unknown constant in a reservoir logging curve section, the objective function of the inversion of the logging curve can be defined that a superscript M represents a simulation longitudinal wave velocity, O represents a logging observation longitudinal wave velocity, and w Rho and w rho represent normalized weighted coefficients; and the objective function is a nonlinear function of the bulk modulus, the shear modulus and the density of each mineral component. The method can be applied to a sand shale reservoir, and carbonate rock and other complex reservoirs.

The invention discloses a method suitable for positioning a hydraulic fracturing micro-seismic source. The method includes: building a micro-seismic-monitoring observation system, acquiring logging information and other seismic data, building an initial speed model, researching and analyzing regional stratum conditions and perforation records, determining background interference and micro-seismic signal features, performing noise compression on fracturing records and performing effective waveform identification on micro-seismic signals, and using methods such as first break picking and manual intervention to pick the first break travel time of a direct wave, wherein the travel time of the perforation records is used for optimizing the speed model, and other effective events are used for the inversion positioning of the seismic source. The method has the advantages that transverse wave travel time is added on the basis that longitudinal wave travel time is used, the micro-seismic source is positioned by using the longitudinal wave travel time and the transverse wave travel time to perform simultaneous constraining, the inversion uses a method combining global searching and local searching, and the method is high in positioning precision and high in calculation efficiency.

The invention discloses a method for predicting carbonate formation pore pressure by using log information. The method for predicting the carbonate formation pore pressure by using the log information is based on the effective stress theorem; and by establishing a framework longitudinal wave velocity and pore fluid longitudinal wave velocity equation, a carbonate formation pore pressure equation is established, so that the carbonate formation pore pressure is detected according to the measured log information, scientific evidences are provided for determining safety drilling fluid density during drilling design, and carbonate formation underground complex accidents in the construction process are effectively prevented.

The invention relates to a welding structure residual stress ultrasonic lossless measurement device and a method, in particular to a device and a method using ultrasonic for measuring the residual stress of a welding structure, belonging to the residual stress measurement field. The method aims at overcoming the problems of a traditional stress measurement method that work pieces are destroyed, time is consumed and the residual stress measurement can not be satisfied under the service condition of the welding structure. The two ends of a probe group of the invention are respectively connected with an impulse signal source and a signal receiving processing device which is connected with a display. And a microcontroller is embedded in the signal receiving processing device. In said method, the coordinate of a measured point is determined; the probe group emits impulse signals sent out from the impulse signal source into a work piece through a first critical refraction angle to generate critically refracted longitudinal waves, wherein, enveloping data are read by the signal receiving processing device and are discretized into digital signals and FIR filtering waves; total enveloping weight eigenvalue Mn is worked out; abnormal data are removed according to Brubbs criterion after one measured point is measured for a plurality of times, measuring position is changed for measuring again, and Mn and Mn+1 are worked out according to two measuring points to calculate the residual stress Delta of the work piece.

The invention provides a method for optimizing a design of a vertical seismic profile observation system for seismic exploration, which comprises the following steps: establishing a seismic geological model by known data; distributing more than two different observation systems; forwarding a response of a seismic wave field; calculating a position of a reflective spot, incident and reflection angles and length or ray impact frequency, and counting characteristic parameters again to construct an analysis map; and determining the optimal scheme for actual exploration according to a geological target. The method adopts multi-parameter analysis based on a spacial model, has strong rationality of results, adapts to details, can improve data acquisition quality, is suitable for homogeneous spaces and one-dimensional, two-dimensional or three-dimensional models, can be used for non-zero spacing, Walkaway and 3D-3C VSP exploration designs, and also can be used for analyzing VSP exploration designs of longitudinal waves, transverse waves and converted waves.

The invention discloses a method and device for determining formation pressure. The method includes the steps that amplitude preservation processing is carried out on longitudinal wave PP and converted wave PS seismic data so that superposition data of multiple portions can be obtained, and a longitudinal wave impedance body, a transverse wave impedance body and a density body are obtained in a pre-stack PP and PS joint simultaneous inversion method according to logging information; the longitudinal wave impedance body, the transverse wave impedance body and the density body are converted into depth domains; pressure of overlying strata is calculated according to the density body; effective stress of a framework is calculated according to the longitudinal wave impedance body, the transverse wave impedance body and the density body; the formation pressure is calculated according to the pressure of the overlying strata and the effective stress of the framework. Precision of formation pressure seism prediction can be improved.

A waveguide includes a dielectric substrate having first and second opposed surfaces defining a longitudinal wave propagation path therebetween; and a conductive grid on the first surface of the substrate and comprising a plurality of substantially parallel metal strips, each defining an axis. The grid renders the first surface of the substrate opaque to a longitudinal electromagnetic wave propagating along the longitudinal wave propagation path and polarized in a direction substantially parallel to the axes of the strips. The grid allows the first surface of the substrate to be transparent to a transverse electromagnetic wave having a transverse propagation path that intersects the first and second surfaces of the substrate and having a polarization in a direction substantially normal to the plurality of metal strips. A diffraction grating on the second surface allows the waveguide to function as an antenna element that may be employed in a beam-steering antenna system.

The invention relates to a seismic horizon calibration method utilizing a vertical seismic profiling (VSP) and well-logging combination. The seismic horizon calibration method comprises the following steps: measuring and obtaining a longitudinal wave time-depth relationship and a corridor stacking profile according to zero offset data, performing well logging and obtaining acoustic well logging and density well logging data, calculating an acoustic wave time-depth relationship and a VSP time-depth relationship to get time difference, correcting an acoustic wave curve, obtaining a synthetic record through corrected well-logging curve and seismic wavelet convolution, making a horizon calibration chart after the time shift quantity of a VSP corridor and the correct polarity are determined and performing horizon calibration on a ground seismic profile according to known drilling geological stratification. According to the seismic horizon calibration method, the acoustic well logging error and the frequency dispersion effect are eliminated, the synthetic record making precision is improved, human factors in the calibration are reduced, and the calibration accuracy is improved.

An ultrasonic tester of the fastening force for screw bolt is composed of longitudinal wave transducer connected serially to ultrasonic emitter, longitudinal wave receiver and amplifer, transverse wave transducer connected serially to ultrasonic emitter, transverse wave receiver and amplifier, displacement sensor connected serially with thickness measuring circuit, A/D converter and DSP, temp sensor connected serially to temp measuring circuit, A/D converter and DSP, main oscillator, time pulse generator, and ROM. Its feature is use of sono-elasticity principle.

The invention discloses a method for determining a fluid by utilizing seismic fluid impedance. The method comprises the following steps: exciting and recording a seismic wave to obtain an angle gather; eliminating signal frequency distortion caused by a normal moveout correction stretching effect; extracting longitudinal wave reflectivity attributes and weighted transverse wave reflectivity attributes from the compensated angle gather; computing improved fluid factors; obtaining logging data to obtain a fluid impedance curve; performing iterative inversion to obtain a section of the fluid impedance; qualitatively analyzing fluid anomalies in pores by the fluid factors, and describing spatial distribution of the fluid by the fluid impedance. The method helps accurately extract the fluid factors and directly identify components of the fluid in the pores without an assumption of a velocity ratio of the longitudinal wave to the transverse wave as well as the relation between density and the longitudinal wave velocity, which reduces ambiguity of gas layer identification, realizes direct conversion from the fluid factors to the fluid impedance and improves the precision of gas reservoir identification.

The present invention belongs to the field of high molecular material technology, and is especially one kind of polymer material for seismic physical model and its preparation process. The polymer material consists of epoxy resin mixture comprising epoxy resin and assistant and silicone rubber mixture comprising silicone rubber and assistant in the weight ratio of 0-100. The polymer material is prepared through preparing epoxy resin mixture and silicone rubber mixture separately, mixing these two components in certain weight ratio inside some container via stirring to obtain model material, setting the container inside sealed box to vacuum pump for eliminating bubble, molding, curing inside the mold at 15-25 deg.c for 5-9 days, and demolding to obtain the seismic physical model. The model material has longitudinal wave speed regulating range of 1000-2850 m/s.