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Due to population growth and global technological development, energy consumption has increased exponentially. The global energy crisis opens up many hotly debated topics regarding energy generation and consumption. Not only is energy production in short supply due to limited energy resources but efficient and sustainable storage has become a very important goal. Currently, there are energy storage devices such as batteries, capacitors, and super-capacitors. Supercapacitors or electrochemical capacitors can be very advantageous replacements for batteries and capacitors because they can achieve higher power density and energy density characteristics. The evolution and progress of society demand the use of innovative and composite nanostructured metal oxide materials, which fulfill the requirements of high-performance technologies. This review mainly addresses the synthesis techniques and properties of 2D and 3D metal oxide nanostructured materials, especially based on Ti, Fe, Ga, and Sn ions, electrochemical methods used for the characterization and application of 2D, and 3D nanostructured metal oxide structures in electrochemical storage systems of energy. [ABSTRACT FROM AUTHOR]

For a further understanding on 3D shock train structure and correlation between 3D and 2D shock trains at Mach 1.5 and 3.0, the SST turbulence model based on Reynolds average algorithm was employed to simulate the 3D and 2D structures of the shock trains in the isolator respectively, of which the mesh sizes were 18 million and 200 thousand, respectively. First, when the full flow state of the nozzle was completely converged, the shock train structure was induced by a linearly increasing back pressure at the outlet. Then, the 3D shock train simulation results in xy-plane and zx-plane perspectives were analyzed. Finally, structures of the 3D shock train in different slices and structures of the 2D shock train were analyzed for comparison. It is found that the shock train at Mach 1.5 is symmetrical in xy-plane and zx-plane perspectives, which is highly similar to the 2D simulation results. However, the shock train at Mach 3.0 is symmetrical in the xy-plane perspective, while it is asymmetrical in the zx-plane perspective. The asymmetrical structure is highly similar to 2D simulation results. Therefore, there is a ″quasi-2D area″ in the 3D shock train. For the shock train at Mach 1.5, the structures in the areas including the central position and a certain range on both sides of the xy-plane and zx-plane perspectives can be approximated as 2D structures (The proportion of ″quasi-2D area″ is about 40%); for the shock train at Mach 3.0, the structures in the areas including the central position and a certain range on both sides of the symmetrical viewing angle can be approximated as 2D structures (The proportion of ″quasi-2D area″ is about 60%).

The understanding of the functional properties of mitochondrial transfer RNA (mt tRNAs) depend on the knowledge of its structure. tRNA acts as an interface between polynucleotides and polypeptides thus, they are key molecules in protein biosynthesis. The tRNA molecule has a functional design and, given its importance in the translation of mitochondrial genes, it is plausible that modifications of the structure can affect the synthesis of proteins and the functional properties of the mitochondria. In a previous work, the mitochondrial genome of an individual of the nesting Caretta caretta of the Colombian Caribbean was obtained, where specific mutations were identified in the only tRNALeu (CUN), tRNATrp and tRNALys genes. In order to analyze the effect of these mutations on these three mt tRNAs, the prediction of 2D and 3D structures was performed. Genes were sequenced in 11 nesting loggerhead turtles from the Colombian Caribbean. Two-dimensional structures were inferred using the ARWEN program, and three-dimensional structures were obtained with the RNA Composer 3D program. Two polymorphisms were identified in tRNATrp and another one was located in tRNALys, both specific to C. caretta. The thymine substitution in nucleotide position 14 of tRNATrp could constitute an endemic polymorphism of the nesting colony of the Colombian Caribbean. Two 2D and three 3D patterns were obtained for tRNATrp. In the case of tRNALys and tRNALeu 2D and 3D structures were obtained respectively, which showed compliance to canonical structures, with 4 bp in the D-arm, 4-5 bp in the T-arm, and 5 bp in the anticodon arm. Moderate deviations were found, such as a change in the number of nucleotides, elongation in loops or stems and non- Watson-Crick base pairing: adenine-adenine in stem D of tRNATrp, uracil-uracil and adenine-cytosine in the acceptor arm of the tRNALys and cytosine-cytosine in the anticodon stem of the tRNALeu. In addition, distortions or lack of typical interactions in 3D structures gave them unique characteristics. According to the size of the variable region (4-5 nt), the three analyzed tRNAs belong to class I. The interactions in the three studied tRNAs occur mainly between D loop—variable region, and between spacer bases—variable region, which classifies them as tRNA of typology II. The polymorphisms and structural changes described can, apparently, be post-transcriptionally stabilized. It will be crucial to perform studies at the population and functional levels to elucidate the synthetic pathways affected by these genes. This article analyses for the first time the 1D, 2D and 3D structures of the mitochondrial tRNALys, tRNATrp and tRNALeu in the loggerhead turtle. [ABSTRACT FROM AUTHOR]

The ever-increasing demand for portable smart devices through an extensive range of military, commercial, industrial, and consumer sectors has faced scientists with various challenges. Electromagnetic (EM) pollution is a critical issue threatening the general function of surrounding electronic systems and human well-being. The graphene family (GF) has been investigated thoroughly during the last decade to satisfy the need for light and cost-effective portable devices and address EM pollution and effective shielding devices from its adverse effects. GF has presented an incredible ability to attenuate the EM pollution and, therefore, be used as an alternative for the conventional metal-based electromagnetic interference (EMI) shielding materials. Due to the importance of this topic and the necessity of finding a practical solution for the real-life application of EMI shielding materials, we report the recent research progress and development status of using GFs as EMI shielding materials in a broad frequency range. This review surveys the shielding effectiveness of graphene as a two-dimensional (2D) structure (freestanding thin film and coating), skeleton, filler in polymers' matrix, and three-dimensional (3D) structure (foam and aerogel). Moreover, the shielding mechanism of the materials is investigated comprehensively. This review will briefly discuss the importance of using graphene as an alternative to the conventional shielding material. In the following sections, the EMI shielding performance of graphene as 2D structure, skeleton, filler, and 3D structure is reviewed, and the influence of their conductivity, thickness, and composition on their shielding characteristics is investigated. Finally, the outlooks and conclusions of the recent research will be discussed. [Display omitted] • The shielding effectiveness of graphene-based materials including, 2D structures (freestanding thin film and coating), 3D structures (foam and aerogel), graphene as a matrix, and graphene as filler in polymers, has been surveyed. • The dominant shielding mechanism of graphene-based materials has been described. • Future challenges of electromagnetic waves shielding have been discussed. [ABSTRACT FROM AUTHOR]