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1.
Novel lead-free (1-x)Ba0·9Ca0·1Ti0·9Zr0·1O3-xSrNb2O6 ceramics were synthesized via a two-step high energy ball milling process. The evolution of microstructural properties, phase transformation, and energy storage characteristics was comprehensively investigated to assess the applicability of material in multi-layered ceramic capacitors. The substitution of SrNb2O6 (SNO) in Ba0·9Ca0·1Ti0·9Zr0·1O3 (BTCZ) has resulted in substantial improvement in materials density along with a small increase in the grain size of the synthesized ceramic. A thorough microstructural investigation indicates an excellent dispersibility and compatibility between BTCZ and SNO phases. With an increase in SNO substitution, a transition from typical ferroelectric to relaxor ferroelectric has been observed, which has led to a significantly slimmer ferroelectric loop along with frequency dispersive dielectric properties. The optimized composition (i.e., x = 0.10) exhibits an ultra-high recoverable energy density of 2.68 J/cm3 along with a moderately high energy efficiency of 83.4%. Further, SNO substituted samples have also shown an enhancement in breakdown strength. The improvement in energy storage performance and breakdown strength of SNO substituted BTCZ composites are mainly attributed to relatively homogeneous grain morphology, optimum grain size, microstructural density, and improved grain boundary interface. 相似文献
2.
Nano-sized light rare-earth (La, Pr, Nd, and Sm) doped Ba0.90Ca0.10Ti0.90Zr0.10O3 ceramics were synthesized to enhance the energy storage performance. The Rietveld study of bare and doped samples has shown tetragonal crystal symmetry and a single-phase perovskite structure. The rare-earth addition in Ba0.90Ca0.10Ti0.90Zr0.10O3 has resulted in a remarkable change in the microstructure of the doped samples. The addition of Nd in Ba0.90Ca0.10Ti0.90Zr0.10O3 lattice has resulted in optimum grain size and density among the five compositions. As a result of improvement in morphological characteristics in the Nd-doped sample, the dielectric, ferroelectric and piezoelectric characteristics were significantly enhanced. The Nd-doped sample has shown a relaxor behavior with a maximum dielectric constant of 10788 combined with a high saturation polarization of 41.88 μC/cm2. Further, the material has shown optimum electromechanical behavior with excellent aging characteristics. The obtained properties of Nd-doped Ba0.90Ca0.10Ti0.90Zr0.10O3 sample justifies its potential application in multi-layer energy storage capacitors. 相似文献
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4.
Early-age hydration of cement is enhanced by slightly soluble mineral additives (ie, fillers, such as quartz and limestone). However, few studies have attempted to systematically compare the effects of different fillers on cementitious hydration rates, and none have quantified such effects using fillers with comparable, size-classified particle size distributions (PSDs). This study examines the influence of size-classified fillers [ie, limestone (CaCO3), quartz (SiO2), corundum (Al2O3), and rutile (TiO2)] on early-age hydration kinetics of tricalcium silicate (C3S) using a combination of experimental methods, while also employing a modified phase boundary and nucleation and growth model. In prior studies, wherein fillers with broad PSDs were used, it has been reported that between quartz and limestone, the latter is a superior filler due to its ability to partake in anion-exchange reactions with C-S-H. Contrary to prior investigations, this study shows that when size-classified and area matched fillers are used—which, essentially, eliminate degrees of freedom associated with surface area and agglomeration of filler particulates—the filler effect of quartz is broadly similar to that of limestone as well as rutile. Results also show that unlike quartz, limestone, and rutile—which enhance C3S hydration kinetics—corundum suppresses hydration of C3S during the first several hours after mixing. Such deceleration in C3S hydration kinetics is attributed to the adsorption of aluminate anions—released from corundum's dissolution—onto anhydrous particulates’ surfaces, which impedes both the dissolution of C3S and heterogeneous nucleation of C-S-H. 相似文献
5.
ABSTRACTIn India, of late, micro-irrigation has received considerable policy focus. However, as of 2017, only about 10% of the potential area is under micro-irrigation. The present study analyzes the pattern and equity issues of distribution of micro-irrigation in India and identifies the potential correlates. The regression analysis reveals that the stage of groundwater development and agro-climatic differences significantly influence the spread of micro-irrigation. The relatively low spread of micro-irrigation in states with over-exploited groundwater needs attention. Overall, the study points to the need to revamp the current micro-irrigation development programmes, which focus excessively on subsidy. 相似文献
6.
Juho Hamari Johannes Koski Aditya Johri 《International journal of human-computer interaction》2019,35(9):804-819
In recent years, augmented reality games (ARGs) such as Pokémon Go have become increasingly popular. These games not only afford a novel gaming experience but also have the potential to alter how players view their physical realities. In addition to the common experiences and gratifications people derive from games, (location-based) ARGs can afford, for example outdoor adventures, communal activities, and health benefits, but also create problems stemming from, for example privacy concerns and poor usability. This raises some important research questions as to what drives people to use these new applications, and why they may be willing to spend money on the content sold within them. In this study, we investigate the various gratifications people derive from ARGs (Pokémon Go) and the relationship of these gratifications with the players’ intentions to continue playing and spending money on them. We employ data drawn from players of Pokémon Go (N = 1190) gathered through an online survey. The results indicate that game enjoyment, outdoor activity, ease of use, challenge, and nostalgia are positively associated with intentions to reuse (ITR), meanwhile outdoor activity, challenge, competition, socializing, nostalgia and ITR are associated with in-app purchase intentions (IPI). In contrast with our expectations, privacy concerns or trendiness were not associated with reuse intentions or IPI. 相似文献
7.
Sarkar Aditya Murty S. V. S. Narayana Prasad M. J. N. V. 《Metallurgical and Materials Transactions A》2020,51(9):4742-4752
Metallurgical and Materials Transactions A - The Cu-Cr-Zr-Ti alloy was subjected to single-hit plane strain compression tests in the temperature range of 923 K to 1073 K... 相似文献
8.
Wireless Networks - The Internet of Things (IoTs) enables coupling of digital and physical objects using worthy communication technologies and introduces a future vision where computing systems,... 相似文献
9.
Saraswati Teguh Endah Imantaka Aditya Anwar Miftahul Heraldy Eddy 《Protection of Metals and Physical Chemistry of Surfaces》2021,57(4):779-785
Protection of Metals and Physical Chemistry of Surfaces - In situ direct formation of titanium carbide (TiC) was realized via tungsten inert gas (TIG) arc surface cladding using titanium dioxide... 相似文献
10.
Wireless Networks - Unmanned Aerial Vehicles (UAVs) deployed as flying base stations is a promising technology for enhancing the quality of service (QoS) and quick recovery from unexpected damages... 相似文献