Synthesis and structure determination of calcium silicate-cellulose nanograss biocomposite

The 100% phase pure calcium silicate nanoparticles (CSNPs) of the α-wollastonite phase by hydrothermal synthesis is achieved first. Next this work reports the first-ever microwave-assisted low temperature synthesis of calcium silicate-cellulose nanograss composites. The characterization by FESEM studies confirm that calcium silicate-cellulose composites possess the nanograss like morphology spread over the matrix of calcium silicate. The structural information of the calcium silicate-cellulose composites are derived by both theoretical and experimental techniques. Low-energy ground state geometrical structures of the cellulose on the triclinic wollastonite surfaces and their interactions have been primarily determined by Density Functional Theory. Accordingly, the short-range structural information is confirmed by Pair Distribution Function analysis. Structural information along with binding interactions are also confirmed from X-ray photoelectron spectroscopy. The implications of these detailed analysis of structures in tuning the properties of such ceramic polymeric hybrid composites for futuristic endodontic application is discussed.     

Model-driven development of accessible software: a systematic literature review

Universal Access in the Information Society - The lack of accessibility in software products is a problem, which is difficult to solve, due to the absence of accessible support tools and the scarce...     

Quantized Grain Boundary States Promote Nanoparticle Alignment During Imperfect Oriented Attachment

Oriented attachment (OA) has become a well‐recognized mechanism for the growth of metal, ceramic, and biomineral crystals. While many computational and experimental studies of OA have shown that particles can attach with some misorientation then rotate to remove adjoining grain boundaries, the underlying atomistic pathways for this “imperfect OA” process remain the subject of debate. In this study, molecular dynamics and in situ transmission electron microscopy (TEM) are used to probe the crystallographic evolution of up to 30 gold nanoparticles during aggregation. It is found that Imperfect OA occurs because 1) grain boundaries become quantized when their size is comparable to the separation between constituent dislocations and 2) kinetic barriers associated with the glide of grain boundary dislocations are small. In support of these findings, TEM experiments show the formation of a single crystal aggregate after annealing nine initially misoriented, agglomerated particles with evidence of dislocation activity and twin formation during particle/grain alignment. These observations motivate future work on assembled nanocrystals with tailored defects and call for a revision of Read–Shockley models for grain boundary energies in nanocrystalline materials.     

Nucleic-Acid Structures as Intracellular Probes for Live Cells

The chemical composition of cells at the molecular level determines their growth, differentiation, structure, and function. Probing this composition is powerful because it provides invaluable insight into chemical processes inside cells and in certain cases allows disease diagnosis based on molecular profiles. However, many techniques analyze fixed cells or lysates of bulk populations, in which information about dynamics and cellular heterogeneity is lost. Recently, nucleic-acid-based probes have emerged as a promising platform for the detection of a wide variety of intracellular analytes in live cells with single-cell resolution. Recent advances in this field are described and common strategies for probe design, types of targets that can be identified, current limitations, and future directions are discussed.     

Analysis,design, and minimum phase selection of high power interleaved DC–DC converter

The primary use of interleaved bidirectional DC–DC converters (IBC) is for high current applications due to the inherent property of ripple cancellation, high redundancy, and improved efficiency. Proper analysis and design are required to improve the power density and reduce the cost of the $N$-phase IBC. Ripple current analysis plays a vital role in choosing the inductor and filter capacitors to minimize the size of an IBC. This paper presents the simple and generalized formulas for the current ripple minimization of $N$-phase IBC. Also, the inductor is designed with two different core materials, namely, Ferrite and Sendust. It is observed that the area product and weight of the magnetics have been reduced by 22% and 23%, respectively, for Sendust core in comparison with the Ferrite core. Furthermore, a discussion regarding the thermal analysis of IGBT modules to select an appropriate heat sink is stated. Moreover, the minimum phase selection has been proposed by considering several constraints such as area product of the core, discrete components size based on ripple analysis, cost of all components, and converter efficiency. The prototype of the selected minimum phase IBC has been developed and tested for a 7.5 kW power level using TMS320F28335.