The paper presents methods of inspection of masonry arch railway
bridges. Results of a test program are demonstrated where the efficiency of
various non-destructive testing methods for the inspection of arches was
studied. It is shown that non-destructive investigation can provide valuable
information regarding the condition of the bridge and help establishing basic
input parameters for structural analysis and condition assessment.
Three types of porous limestone from Sóskút quarry and two limestone types obtained directly from Matthias Church of Budapest (both in Hungary) were used to test the performance of five stone consolidants. The quarry specimens were treated under laboratory conditions by saturation. Three types of silicic acid ester, an aliphatic uretan resin and a polymethyl methacrylate were applied to the stone. Physical parameters such as density, porosity, ultrasonic sound velocity and Duroscope rebound value were measured on untreated and treated samples. The absorption rate of different consolidants was also detected. The physical properties of untreated and treated specimens were compared in order to analyze the performance of the consolidants. Duroscope tests have shown that after consolidation there is an increase in surface strength.
Nuclear NDT methods cover many different fields concerning, e.g., industry, medicine and archeology. Each field is characterized
by particular requirements, such as the rigorous integrity of the samples (artistic objects), very short measuring time (on-line
controls), minimum absorbed doses (radiodiagnosis in medicine), etc. Analytical applications of nuclear NDT methods requiring
portable devices are described. The choice of some typical parameters and the optimization of the nuclear instrumentation
The paper deals with the monitoring of the structural changes of fine-grained cement-based composites in the early-age using acoustic emission method. After mixing, the cement-based materials exhibit continuous time-dependent structural changes which lead to the changes in the mechanical properties due to the chemical and physical processes. The events which are emitted due to the internal structure formation were detected using the acoustic emission techniques. A number of AE events are released due to the formation of new crystalline phases and due to microcracking in the material structure during the setting and hardening. The aim of the performed experiments was to extend the knowledge in the field of the early-age material characteristics and in the field of the internal structure formation of the cement-based materials. The results from temperature measurement show that mixture with microsilica has more slowly raised the internal temperature than mixture without microsilica. The results from acoustic emission measurement show that mixture with microsilica has lower activity of acoustic emission than mixture without microsilica during first six hours from measurement start.
Germanium spectrometers must be operated at liquid nitrogen temperatures. Other detectors operate better when cooled. Many
applications, because of hostile environments, inaccessibility, remote location, long duration, etc., are compromised, or
totally precluded, by the requirement for liquid nitrogen. A Stirling cycle refrigerator based on a linear motor design, which
is acoustically and vibrationally quiet, does not require secondary cooling, and operates unattended for years, is under development.
System design and specifications are presented. Applications to cooled laser monitoring equipment. SQUID-based detection systems,
environmental cleanup and monitoring, medical diagnostics, non-destructive testing systems, communication equipment, computer
electronics, and imaging systems are discussed.
Stone masonry arch bridges in North Hungary represent cultural heritage values. For the maintenance and preservation of these bridges detailed mapping of lithologies and weathering forms are required. The purpose of this paper is to present the identified lithotypes, their conditions (weathering grade) and their petrophysical properties by using in situ lithological mapping, documentation of weathering forms, non-destructive tests and laboratory analyses. Furthermore these analyses demonstrate the difficulties of characterization and diagnostics of the historical construction materials. Additionally the results of condition assessments and the properties of the four different dimension stones from four different sites provide examples for the large dissimilarities regarding the strength parameters. The above-listed parameters are required as input data for stability calculations and modeling of these structures.
Authors:S. Salunke, Kulwant Singh, A. Bidaye, and J. Goswami
Partitioning of plutonium from uranium is an important step in the reprocessing of spent fuel by PUREX process of solvent
extraction using 30% TBP-dodecane. This is achieved by selectively reducing the Pu in solution to least extractable trivalent
state by uranous nitrate as the reductant. The latter is conventionally produced by electrolytic reduction of uranyl ion in
presence of hydrazine nitrate as uranous nitrate stabilizer using Pt-coated titanium as the anode. The anode plating wears
out after period of operation thus affecting the process efficiency and hence the quality control testing of platinum plated
electrode becomes important. This article describes the use of Beta backscattering method with strontium-90 radioisotope as
non-destructive testing tool for measuring the coating thickness of the sample Ti electrode. The surface characteristics and
coating morphology were also examined by scanning electron microscope and the micrographs are presented.
Authors:A. Heller, L. Shi, J. Brenizer, and M. Mench
Neutron radiography (NR) and computed tomography (NCT) are important non-destructive testing tools which determine information
about an object’s interior structure and material properties. Although water quantification using 2-D neutron imaging has
been applied to fuel cells for over a decade, the development of an accurate 3-D method has only recently been demonstrated.
The 3-D water quantification technique developed at the Pennsylvania State University’s Radiation Science and Engineering
Center has been applied to the quantification of both liquid and ice phase water. Quantification results of water and ice
inside a known small channel test object were accurate to within 2%. This capability allows the quantification of ice within
a fuel cell flow field under cold-start conditions.