Radio-wave Method Research Articles

Determination of sound velocities of “overcompressed” detonation in HMX-based explosive

The authors present results of determination of sound velocities in explosion products (EP) of HMX-based explosive overcompressed up to the pressures of 50–85 GPa by overtaking unloading method. The radiowave and optical methods are used to record the time when a front of overcompressed detonation wave in investigated sample of high explosive (HE) is overtaken by expansion wave, which propagates from the back surface of impactor with sound velocity. The data on sound velocities, which were independently obtained by two different methods, were in agreement. The methods with use of radiointerferometer and indicator liquid are rather effective for determination of sound velocities in overcompresed EP and for investigation of parameters at the Jouget point of various HEs, which are required for calibration of their equations of state (EOS).

Evaluation of radio-wave method of soil massif

Evaluation of radio-wave method of soil massif

Development and application of radiowave photoelasticity for the fracture analysis of dielectrics

The radiowave photoelasticity method is developed and is justified for use in the fracture mechanics of dielectrics. The damage tensors of a material with microcracks are considered. The basic equations of the method are given. The time-dependence of microcrack density is analyzed. Numerical results are presented and analyzed

ChemInform Abstract: Electron Spin Resonance (ESR) Microscopy in Materials Science

Imaging of the spatial distribution of the properties of materials, par­ ticularly on a microscopic scale, provides an insight into their physical and chemical natures. Many analytical methods present a spatial distribution as an image. Computer tomography (CT) X-ray used in hospitals gives an image of the density distribution. Magnetic resonance imaging (MRI) is computer tomographic nuclear magnetic resonance (NMR). Magnetic resonance is a method of radiowave or microwave absorption spectroscopy in which the sample is placed in a static magnetic field. Magnetic moments of nuclear spins or of electron spins cause the absorp­ tion of the electromagnetic waves; the resonance is called NMR for nuclear spins, and electron spin resonance (ESR) for unpaired electrons. The latter is sometimes called electron paramagnetic resonance (EPR) (1-3). ESR or EPR finds application in many different branches of physical, chemical, biological, and geological sciences. The term EPR has a wider meaning since it includes paramagnetic ions with several electron spins. However, the more descriptive and readily understood term ESR may be preferable for general use of the method. CT-NMR employs magnetic field gradients for spatial resolution (4). NMR imaging with high enough resolution to give an image of a biological cell is termed NMR microscopy. The resolution of ESR imaging has been

Results of Field Tests on Radio-Wave Heating for Soil Remediation

After developing the radio-wave technique for various conditions in laboratory-scale and technical plant-scale experiments, field tests in combination with biodegradation and soil vapor extraction were carried out at three sites: (i) a bioremediation facility for ex situ cleaning of soil, (ii) in situ remediation of contamination at a former storage facility for organic solvents, and (iii) a polluted soil under a former petrol station. Various electrode arrangements such as parallel plates, rod arrays, and coaxial antenna were applied in order to meet the site-specific requirements optimally. Soil temperatures between 35 and 100 degrees C were established. The successful tests gave much insight into the engineering, physical, biological, and chemical aspects of radio-wave application. General conclusions on the appropriateness and competitiveness of the radio-wave method as well as on preferred application fields are drawn.

Coherent Cherenkov radio emission and problems of ultrahigh-energy cosmic ray and neutrino detection

This review is concerned with prospects for employment of coherent Cherenkov radio emission for detecting ultrahigh-energy cosmic rays and neutrinos. Reasons for interest in and problems of studying the ultrahigh-energy particles are summarized. A history of the development of a radio-wave method and its main merits are recalled. Current experiments and proposals based on this method are briefly discussed with emphasize on the most recent Lunar Orbital Radio Detector (LORD) proposal.

A radio-wave method for detecting and identifying permeable inclusions in stratified inhomogeneous media

The problems associated with the efficiency of practical application of a numerical algorithm for detecting, locating, and identifying inhomogeneous dielectric inclusions in plane-layered media are considered. The results of computational experiments on the determination of both physical and geometric parameters of inhomogeneities and the effect of the measurement error on the quality of the inspection procedure are presented. This method can be used in the nondestructive testing of the quality of industrial dielectric articles.

On the Feasibility of Application of Laser Radiation in Radiowave Methods of Remote Underlying Surface Sensing

A method for increasing the efficiency of radiowave method of remote sensing of the underlying surface using high-power laser radiation is considered in the present paper.

Kinetics of an Elementary Charge Transfer Act Involving Polyatomic Dipole Polarizable Species: A Spectroscopic Study

The possibilities of optical and radiowave spectral methods in investigating the kinetics of elementary acts of charge transfer and phototransfer in irregular condensed systems are studied. It is proposed to study the effect of the electrical double layer on the adsorption of dipole polarizable polyatomic species using the IR spectra of adsorbed species and theoretical quantum-mechanical calculations. An analytical equation is obtained for the extinction coefficient of outer-sphere electron phototransfer between species, which accounts for the interaction of intramolecular vibrations of reacting species with fluctuations of the environment polarization. A method based on the recording of nonlinear electromagnetic radiation and microcurrents of the electrochemical system is theoretically substantiated.

Radio-Wave Measurements and Monitoring Parameters of Industrial Processes with Sensitive Elements Utilizing Slow-Wave Systems

A survey is given of the present state of radio-wave measurement methods and of the design of measurement transducers with sensitive elements utilizing resonant slow-wave systems for monitoring the parameters of industrial processes.

A radio-wave method of measuring liquid level

A new method of monitoring liquid level, based on the use of slow-wave structures, is considered. It is shown, using the example of a liquid dielectric, that it is possible to minimise the measurement error due to changes in the electromagnetic parameters of the liquid. Experimental data confirm the usefulness of the method.

Methods, means, and technology for thickness measurement of products made from composite polymer materials

The characteristic features of acoustic, radiation, thermal, electrocapacitive, and radiowave methods, tools, and technology of nondestructive testing of the thickness and density of products made from composite polymer materials used in different branches of industry are discussed.

Reflection of radiowaves from multilayer protective materials

It is shown that (UHF) radiowave methods for the diagnostics of both thin (surface corrosion) and thick (multilayer composites) materials are highly sensitive. It is also demonstrated that the unambiguous monitoring of the location of defects in multilayer materials can be performed either by using specially selected frequencies for each special type of structures or, more universally, by the solution of inverse multifrequency problems.

Radiowave method of high energy neutrino detection: calculation of the expected event rate

The sensitivity of an ice radiowave detector to the anticipated high energy neutrino fluxes is calculated on the basis of a detailed threshold analysis and computation of the shower production rate. We show that diffuse neutrinos from Active Galactic Nuclei could he detectable in a radio detector of 1 km 2 area established in Central Antarctica.

Radio wave methods of monitoring the electromagnetic parameters of radioabsorbent materials

An analysis of radio wave methods of monitoring electromagnetic parameters over a broad range of frequencies is given. The sensitive elements used in moderating systems are examined.

Radio wave method for study of physical phenomena and chemical conversions in heterogeneous explosives under shock wave action

A method is described for determination of shock wave parameters (wave and mass velocity) in heterogeneous explosives. The example of exciting explosion in an octogene composition by weak shock waves is used to demonstrate the possibility of reliable measurement of the velocity of the initiating shock wave, the depth at which detonation develops, and the extent of the predetonation zone, as well as the character of the change in shock wave velocity upon propagation through the specimen.

Electron Spin Resonance (ESR) Microscopy in Materials Science

Imaging of the spatial distribution of the properties of materials, par­ ticularly on a microscopic scale, provides an insight into their physical and chemical natures. Many analytical methods present a spatial distribution as an image. Computer tomography (CT) X-ray used in hospitals gives an image of the density distribution. Magnetic resonance imaging (MRI) is computer tomographic nuclear magnetic resonance (NMR). Magnetic resonance is a method of radiowave or microwave absorption spectroscopy in which the sample is placed in a static magnetic field. Magnetic moments of nuclear spins or of electron spins cause the absorp­ tion of the electromagnetic waves; the resonance is called NMR for nuclear spins, and electron spin resonance (ESR) for unpaired electrons. The latter is sometimes called electron paramagnetic resonance (EPR) (1-3). ESR or EPR finds application in many different branches of physical, chemical, biological, and geological sciences. The term EPR has a wider meaning since it includes paramagnetic ions with several electron spins. However, the more descriptive and readily understood term ESR may be preferable for general use of the method. CT-NMR employs magnetic field gradients for spatial resolution (4). NMR imaging with high enough resolution to give an image of a biological cell is termed NMR microscopy. The resolution of ESR imaging has been

Determination by the radio-wave method of weakened zones in the bases of structures being constructed in karstified territories : Zaderigolova, M M Soil Mech Found EngngV25, N4, July–Aug 1988, P162–165

Determination by the radio-wave method of weakened zones in the bases of structures being constructed in karstified territories : Zaderigolova, M M Soil Mech Found EngngV25, N4, July–Aug 1988, P162–165

Determination by the radio-wave method of weakened zones in the bases of structures being constructed in karstified territories

Determination by the radio-wave method of weakened zones in the bases of structures being constructed in karstified territories

Nondestructive radiowave method of inspection and its role in increasing product quality

The use of the radiowave nondestructive testing method makes it possible to activate purposeful work on increasing the quality of refractory parts and to accomplish 100% inspection for critical parts.