Synthesis and Properties of Titanium Dioxide Nanoparticles

Natural titanium dioxide (TiO2) occurs in three distinct polymorphs (rutile, anatase, and brookite). Currently, TiO2 gained the attention of several researchers around the world. TiO2 is used in several applications because of its excellent properties (structural, optical, electrical, chemical, non toxic, etc.). Thus, the applications are influenced by its surface, size, morphology, and crystal phase. TiO2 as photocatalyst is widely used in energy and eco-friendly applications involving water purification, hydrogen production, phenol degradation, etc. The novelty of the present chapter lies in explaining the recently reported methods that are used to synthesize TiO2 nanoparticles, such as sol-gel, hydrothermal, precipitation, etc. The different properties of TiO2 are also provided in this chapter

Recent Advances in Ceramic Materials for Dentistry

Dental ceramics constitute a heterogeneous group of materials with desirable optical and mechanical proprieties combined with chemical stability. They are inorganic non-metallic materials used in several applications. These materials are biocompatible to tissue, highly esthetic, with satisfying resistance to tensile and shear stress. Over the past years, several developments in new ceramic materials in dental restoration were achieved, including processing techniques and high mechanical properties. Thus, concepts on the structure and strengthening mechanisms of dental ceramic materials are also discussed. The dental practitioner requires best knowledge concerning indications, limitations, and correct use of started materials. The purpose of this book chapter is to overview advances in new ceramic materials and processes, which are used in dentistry. The properties of these materials are also discussed

Phase Change Materials and Their Applications

Today, the application of phase change materials (PCMs) has developed in different industries, including the solar cooling and solar power plants, photovoltaic electricity systems, the space industry, waste heat recovery systems, preservation of food and pharmaceutical products, and domestic hot water. PCMs use the principle of latent heat thermal storage to absorb energy in large quantities when there is a surplus and release it when there is a deficit. This promising technology has already been successfully implemented in many construction projects. The aim of this book is to assist the scientists and to provide the reader with a comprehensive overview of the properties that characterize the phase change materials from theoretical and experimental perspectives with a focus on their technological applications. The present status and future perspectives of phase change material are discussed

Synthesis and Characterization of Mechanically Alloyed Nanostructured (Ti,Cr)C Carbide for Cutting Tools Application

(Ti,Cr)C is a novel additive for high-performance cermets. In this work, a (Ti0.8Cr0.2)C nanostructured solid solution was synthesized via Mechanical Alloying (MA) from the mixture of of Ti, Cr, and C powders. The MA process was carried out at room temperature under argon atmosphere with a duration limited to 20 h. Phase changes and microstructure evolution of the powders during the MA process were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The results of XRD analysis demonstrated the synthesis of (Ti,Cr)C solid solution with a crystallite size of about 10 nm that were micro-strained to about 1.34%. The crystallite size displays a decreasing trend with increasing milling time. The results of direct observations of structural features by TEM method in 20 h MAed samples shows a good agreement with the results from the XRD analyses

Synthesis and Characterization of Mechanically Alloyed Nanostructured (Ti,Cr)C Carbide for Cutting Tools Application

(Ti,Cr)C is a novel additive for high-performance cermets. In this work, a (Ti0.8Cr0.2)C nanostructured solid solution was synthesized via Mechanical Alloying (MA) from the mixture of of Ti, Cr, and C powders. The MA process was carried out at room temperature under argon atmosphere with a duration limited to 20 h. Phase changes and microstructure evolution of the powders during the MA process were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The results of XRD analysis demonstrated the synthesis of (Ti,Cr)C solid solution with a crystallite size of about 10 nm that were micro-strained to about 1.34%. The crystallite size displays a decreasing trend with increasing milling time. The results of direct observations of structural features by TEM method in 20 h MAed samples shows a good agreement with the results from the XRD analyses

Phenology and phylogeny of Hyalomma spp. ticks infesting one-humped camels (Camelus dromedarius) in the Tunisian Saharan bioclimatic zone

In this study, we report the results of a survey of Hyalomma ticks infesting one-humped camels in southern Tunisia. Examinations were conducted every second or third month on 406 camels in Tataouine district from April 2018 to October 2019. A total of 1902 ticks belonging to the genus Hyalomma were collected. The ticks were identified as adult H. impeltatum (41.1%; n = 782), H. dromedarii (32.9%; n = 626), H. excavatum (25.9%; n = 493), and H. marginatum for a single specimen. Although the camels were infested by ticks throughout the year, the highest overall infestation prevalence was observed in April 2018 (p < 0.01). The overall infestation intensity varied between 2.7 and 7.4 ticks/animal. There were no statistically significant differences in tick infestation prevalence based on age categories of the camels, and the overall infestation prevalence was between 82.7% and 97.4%. Female camels were significantly more infested with ticks (88.3%) than males (65.5%) (p < 0.01). The infestation prevalence of camels varied significantly according to the region where sampling took place (p < 0.01), but no correlations were found with abiotic factors. The preferred attachment sites for adult Hyalomma ticks were the sternum (38.3%; n = 729/1902), around the anus (36.2%; n = 689/1902), udder (18.4%; n = 350/1902), and inner thigh (6.9%; n = 132/1902). Morphological classification of ticks was corroborated by sequencing the cytochrome c oxidase I (Cox1) and 16S rDNA genes, and these sequences were also used to infer phylogenetic relationships. A single H. dromedarii seemed to be a natural hybrid with H. rufipes. More attention should be devoted by the veterinary services to the infestation of camels by ticks

Phenology and phylogeny of

In this study, we report the results of a survey of Hyalomma ticks infesting one-humped camels in southern Tunisia. Examinations were conducted every second or third month on 406 camels in Tataouine district from April 2018 to October 2019. A total of 1902 ticks belonging to the genus Hyalomma were collected. The ticks were identified as adult H. impeltatum (41.1%; n = 782), H. dromedarii (32.9%; n = 626), H. excavatum (25.9%; n = 493), and H. marginatum for a single specimen. Although the camels were infested by ticks throughout the year, the highest overall infestation prevalence was observed in April 2018 (p < 0.01). The overall infestation intensity varied between 2.7 and 7.4 ticks/animal. There were no statistically significant differences in tick infestation prevalence based on age categories of the camels, and the overall infestation prevalence was between 82.7% and 97.4%. Female camels were significantly more infested with ticks (88.3%) than males (65.5%) (p < 0.01). The infestation prevalence of camels varied significantly according to the region where sampling took place (p < 0.01), but no correlations were found with abiotic factors. The preferred attachment sites for adult Hyalomma ticks were the sternum (38.3%; n = 729/1902), around the anus (36.2%; n = 689/1902), udder (18.4%; n = 350/1902), and inner thigh (6.9%; n = 132/1902). Morphological classification of ticks was corroborated by sequencing the cytochrome c oxidase I (Cox1) and 16S rDNA genes, and these sequences were also used to infer phylogenetic relationships. A single H. dromedarii seemed to be a natural hybrid with H. rufipes. More attention should be devoted by the veterinary services to the infestation of camels by ticks