ABSTRACT We describe the study of the re-utilization of egg shell as an alternative mineral source of calcite in the synthesis of calcium titanate (CaTiO3). The raw materials were characterized by X-ray diffraction and X-ray fluorescence; compositions were formulated and sintered under different conditions. After sintering the crystalline phases formed were quantified by the Rietvield (MR) method, analyzes of apparent density (DA), impedance spectroscopy (EIA) and scanning electron microscopy (SEM) were performed. The results reveal the possibility of using the egg shell residue as a source of calcium for the formation of calcium titanate with perovskite structure, it is fundamental to consider studies of technical and economic viability are also developed so that possible applications of interest are feasible.

ABSTRACT We describe the study of the re-utilization of egg shell as an alternative mineral source of calcite in the synthesis of calcium titanate (CaTiO3). The raw materials were characterized by X-ray diffraction and X-ray fluorescence; compositions were formulated and sintered under different conditions. After sintering the crystalline phases formed were quantified by the Rietvield (MR) method, analyzes of apparent density (DA), impedance spectroscopy (EIA) and scanning electron microscopy (SEM) were performed. The results reveal the possibility of using the egg shell residue as a source of calcium for the formation of calcium titanate with perovskite structure, it is fundamental to consider studies of technical and economic viability are also developed so that possible applications of interest are feasible.

ABSTRACT The automotive thermistors are electroceramics with sensorial characteristics housed in metallic cases fixed to the radiator, whose function is to control the temperature of the cooling water of the engine. The objective of this work was to determine the sensitivity of two commercial thermistors applied in automotive vehicle. Characterized thermistors were commercially available, and after disassembling the kits, X-ray diffraction (XRD), scanning electron microscopy (SEM), microanalysis (EDS) and impedance spectroscopy analyzes were performed on the samples. X-ray diffraction indicated that the materials that make up the thermistors have spinel-like atomic structure (AB2O4), in the chemical map via EDS high homogeneity of the chemical components can be observed and the characteristic resistance ratio values (β-factor) are within the range indicated for indicated application Based on the results obtained it is verified that the sensorial characteristics of the thermistors are directly related to their physico-chemical characteristics.

ABSTRACT The automotive thermistors are electroceramics with sensorial characteristics housed in metallic cases fixed to the radiator, whose function is to control the temperature of the cooling water of the engine. The objective of this work was to determine the sensitivity of two commercial thermistors applied in automotive vehicle. Characterized thermistors were commercially available, and after disassembling the kits, X-ray diffraction (XRD), scanning electron microscopy (SEM), microanalysis (EDS) and impedance spectroscopy analyzes were performed on the samples. X-ray diffraction indicated that the materials that make up the thermistors have spinel-like atomic structure (AB2O4), in the chemical map via EDS high homogeneity of the chemical components can be observed and the characteristic resistance ratio values (β-factor) are within the range indicated for indicated application Based on the results obtained it is verified that the sensorial characteristics of the thermistors are directly related to their physico-chemical characteristics.