Predictability of concrete damage level by non-destructive test methods

Non-destructive methods have many advantages over traditional test methods, especially since it does not damage the specimen, it can be used multiple times on the same specimen. These advantages also provide a great benefit in terms of following the property development in concrete as the same specimens are used which eliminates the variations related to the specimens. In this study, it is aimed to determine the damaged amount of concrete produced with different binders by electrical bulk resistivity, resonance frequency, and ultrasonic pulse velocity methods. Firstly, concretes containing different binders were produced, and along with the mechanical properties, ultrasonic wave velocity, resonance frequency, and electrical resistivity values of the produced concrete were determined at the 7, 28, and 90 days. Besides, the specimens were subjected to gradually increase compressive loads and non-destructive methods were used to estimate the extent of damage on specimens. It was attempted to establish a relationship between the damage on concrete specimens and the results obtained by non-destructive methods. Consequently, the compressive strength, electrical resistivity, ultrasonic pulse velocity and resonance frequency values of all specimens increased with the advancing age. It was concluded that the resonant frequency method is more successful than other methods in estimating the amount of damage in concrete.

UNFORMALIZED ASPECTS OF APPLICATION THE NON-DESTRUCTIVE METHODS FOR DETERMINATION OF CONCRETE QUALITY ON ROAD CONCRETE COATINGS

Formulation the problem. Experience with the use of non-destructive testing devices shows that theadjustment of calibration dependences in the conditions of damaged concrete surfaces is difficult. Usually quantitativeanalysis is replaced by qualitative, and methods that allow you to return to the quantitative assessment are notstandardized. That is, the adequacy of property definitions needs to be increased. The purpose of the study is todetermine the possibilities of increasing the adequacy in the using of non-destructive testing devices and to study theinfluence of the peculiarities of the technology of manufacturing concrete pavements on the measurement results.Results: It has been performed a visual inspection of the condition of the coating structure on the basis of currentregulations. The study was performed using an ultrasonic device "Novotest IPSM-U" and a device "Onyx 2.5" (shockpulse method). Measurements were performed both on the surface of the concrete pavement and on the samples takenfrom the structure. During the work, project materials and passports for the concrete mixture were used. Conclusions.Studies have shown that: to obtain evidence-based results in the application of non-destructive methods for determiningthe quality of concrete road pavements, existing methods need to be improved and formalized; it needs to be clarifiedand formalized the methods of providing acoustic contact of receivers − transmitters of ultrasonic vibrations with theconcrete surface and the conditions of interaction the indentors with the concrete surface during the implementation ofthe method of elastic rebound; it is necessary to develop and standartize a method for determining the properties of theconcrete mixture based on the properties of concrete.

A Review of the State-of-Art, Limitations, and Perspectives of Machine Vision for Grape Ripening Estimation

This work highlights the most recent machine vision methodologies and algorithms proposed for estimating the ripening stage of grapes. Destructive and non-destructive methods are overviewed for in-field and in-lab applications. Integration principles of innovative technologies and algorithms to agricultural agrobots, namely, Agrobots, are investigated. Critical aspects and limitations, in terms of hardware and software, are also discussed. This work is meant to be a complete guide of the state-of-the-art machine vision algorithms for grape ripening estimation, pointing out the advantages and barriers for the adaptation of machine vision towards robotic automation of the grape and wine industry.

Application of acoustic microscopy for evaluation of numismatic material

A new non-destructive express method for assessing the authenticity of numismatic material is considered in the paper. Non-destructive methods of pulsed acoustic microscopy in the frequency range of 50-100 MHz were applied. Samples of silver coins dated 1924 and 1979 were examined. The characteristic values of the longitudinal and transverse sonic velocity of the samples were obtained. The method of hydrostatic weighing was used to measure the density of the metal. It was shown that assessment of the authenticity and the safety degree of coins can also be carried out by revealing the internal defects such as corrosion. Acoustic visualization in the reflection mode allows imaging the offset of the obverse relative to the reverse and to determine the centre of the coin deviation, which also confirms the quality of the minting.

Coincident Fluorescence Burst Analysis of dUTP-Loaded Exosome-Mimetic Nanovesicles

The possibility of targeting functionality and low immunogenicity of exosomes and exosome-like nanovesicles makes them promising as drug-delivery carriers. To tap into this potential, accurate non-destructive methods to load them and characterize their contents are of utmost importance. However, the small size, polydispersity and aggregation of nanovesicles in solution, make quantitative characterizations of their loading particularly challenging. Here we develop an ad-hoc methodology based on burst analysis of dual-color confocal fluorescence microscopy experiments, suited for quantitative characterizations of exosome-like nanovesicles and of their loading. We apply it to study exosome-mimetic nanovesicles derived from animal extracellular-vesicles and human red blood cell detergent resistant membranes, loaded with dUTP cargo molecules. For both classes of nanovesicles we prove successful loading and by dual-color coincident fluorescence burst analysis, we retrieve size statistics and quantify the loading. The procedure affords single-vesicle characterizations well-suited for the investigation of a variety of cargo molecules and biological nanovesicle combinations besides the proof-of-principle demonstrations of this study. The results highlight a powerful characterization tool essential for the optimizing the loading process and for advanced engineering of biomimetic nanovesicles for therapeutic drug delivery.