Investigations of Model Multilayer Ceramic Casting Molds in a Raw State by Nondestructive Methods

This article presents the results of research on the use of modern nondestructive methods such as 3D scanning, thermography and computed tomography (CT) to assess the quality of multilayer ceramic molds. Tests were performed on spherical samples of multilayer ceramic molds in the raw state. Samples were made of molding sands composed of quartz and molochite powders, the alcoholic binder hydrolyzed ethyl silicate (ZKE) and an aqueous binder based on colloidal silica. Thickness measurements of spherical forms were made using a 3D scanner. Porosity measurements were made using CT. Additionally, thermography observations of the mold cooling process were made with controlled temperature and humidity. The results of temperature measurements of samples were compared with measurements of thickness and porosity. The practical goal was to determine the possibility of using thermography, 3D scanning and CT as a quick method for detecting mold defects by varying their thickness, porosity and cracks and for final verification of the ceramic molds’ condition before casting.

Detection of the Changes in Li-ion Batteries Using Nondestructive Methods

Lithium-ion batteries are the most used type of batteries for portable devices and electric vehicles. In applications as electric vehicles, they must serve for many years and it is necessary to diagnose their condition. This article is focused on verifying the possibility of detecting changes that occur in the battery during its cycling using a non-destructive method of acoustic emission.

An investigation of the effect of different aggregate types on concrete properties with thin section and nondestructive methods

Concrete is the most important material in construction industry. Aggregate is one of the most important components of concrete, which consists of many different components. In this study, concrete of constant water/cement ratio was produced by using different types of aggregates, and the effect of aggregate on concrete properties was investigated. After determining the physical properties of the aggregates, the textural properties of the aggregates were investigated with the help of image analysis. Standard water cure was applied to concrete test samples for 7, 28, 90, and 180 days. After the curing process, the physical and mechanical properties of the samples were determined by destructive and nondestructive methods. Thin section samples were taken from hardened concrete samples, and cement aggregate interface investigations were performed under microscope. As a result, it has been determined that aggregate type creates a change in concrete strength, and this situation is related to aggregate properties.

Estimation of leaf nitrogen content from nondestructive methods in Eucalyptus tereticornis and Eucalyptus saligna plantations

The determination of leaf nitrogen content (LNC) by indirect methods is essential for silvicultural management of forest crops. The application of photography or rapid measurement equipment, such as chlorophyll index (soil-plant analysis development-SPAD), is increasingly used due to its low-cost, ease of estimation and accuracy. Therefore, the aim of this study was to estimate foliar nitrogen content from nondestructive methods in plantations of Eucalyptus tereticornis and Eucalyptus saligna using three urea treatments (120 kg N ha-1, 240 kg N ha-1 and a control treatment without urea). For each treatment, 10 trees were selected, including four for the validation of the equations. The LNC was directly evaluated for color with the CIEL*a*b* model, photographic measurement with the RGB model, SPAD measurement and destructive estimation of nitrogen in leaves. The results showed negative relationships with the L* (luminosity) and b* (trend from yellow to green) indices, while the a* (red to green trend) index was discarded, with SPAD positive relationships were found with LNC and RGB space. In the R and B indices, the greatest negative relationships were found. It was determined that the multivariate equation Y=a+b1x1+b2x2+…+bnxn can be used for this type of study. It was also determined that the LNC=0.389+0.026SPAD model was the optimum for E. tereticornis and the LNC=3.826-0.001R-0.10B equation was the optimum for E. saligna.