Principles of gas phase processing of ceramics during combustion

In recent years, ceramic materials have found applications in an increasingly wider range of industrial processes, where their unique mechanical, electrical and optical properties are exploited. Ceramics are especially useful for applications in high temperature, corrosive environments, which impose particularly stringent requirements on mechanical reliability. One approach to provide such materials is the manufacture of submicron (and more recently nanometer scale) particles, which may subsequently be sintered to produce a material with extremely high mechanical integrity. However, high quality ceramic materials can only be obtained if particles of known size, polydispersity, shape and chemical purity can be produced consistently, under well controlled conditions. These requirements are the fundamental driving force for the renewed interest in studying particle formation and growth of such materials

A Minimal Architecture for General Cognition

A minimalistic cognitive architecture called MANIC is presented. The MANIC architecture requires only three function approximating models, and one state machine. Even with so few major components, it is theoretically sufficient to achieve functional equivalence with all other cognitive architectures, and can be practically trained. Instead of seeking to transfer architectural inspiration from biology into artificial intelligence, MANIC seeks to minimize novelty and follow the most well-established constructs that have evolved within various sub-fields of data science. From this perspective, MANIC offers an alternate approach to a long-standing objective of artificial intelligence. This paper provides a theoretical analysis of the MANIC architecture.Comment: 8 pages, 8 figures, conference, Proceedings of the 2015 International Joint Conference on Neural Network

Evaluation of electrospray differential mobility analysis for virus particle analysis: Potential applications for biomanufacturing.

The technique of electrospray differential mobility analysis (ES-DMA) was examined as a potential potency assay for routine virus particle analysis in biomanufacturing environments (e.g., evaluation of vaccines and gene delivery products for lot release) in the context of the International Committee of Harmonisation (ICH) Q2 guidelines. ES-DMA is a rapid particle sizing method capable of characterizing certain aspects of the structure (such as capsid proteins) and obtaining complete size distributions of viruses and virus-like particles. It was shown that ES-DMA can distinguish intact virus particles from degraded particles and measure the concentration of virus particles when calibrated with nanoparticles of known concentration. The technique has a measurement uncertainty of ≈20%, is linear over nearly 3 orders of magnitude, and has a lower limit of detection of ≈10(9)particles/mL. This quantitative assay was demonstrated for non-enveloped viruses. It is expected that ES-DMA will be a useful method for applications involving production and quality control of vaccines and gene therapy vectors for human use

Ignition and Combustion Characterization of Nano-Al-AP and Nano-Al-CuO-AP Micro-sized Composites Produced by Electrospray Technique

AbstractMetal powders such as aluminum nanoparticles (Al NPs) have been found huge potential as reactive additives to highly increase energy density in various energetic systems such as propellants, explosives and pyrotechnics. However, it is suffering issues of agglomeration and post-combustion aggregates, which largely reduce the energy utilization efficiency and the energy release rate. One option to eliminate this disadvantage is to coat the nanoparticles with gas generator which can produce gas to prevent the sintering. This work use electrospray technique to assemble Al NPs and Al-CuO NPs into microparticles, with coating of gas generator-ammonium perchlorate (AP) to produce gas to prevent possible sintering, thus obtaining a highly reactive Al-based composites. The Al/CuO NPs composites are ignited in a confined cell to measure its combustion pressure history. The peak pressure and the pressurization rate of Al/CuO/AP is more than 3X higher and faster, compared to the physically mixed Al/CuO nanothermite. This work provides an ideal approach to prepare Al NPs based energetic materials such as solid propellant or solid fuel air explosives

Enhanced Thermal Decomposition Kinetics of Poly(lactic acid) Sacrificial Polymer Catalyzed by Metal Oxide Nanoparticles

Poly Lactic Acid (PLA) has been used as a sacrificial polymer in the fabrication of battery separators and can be employed in 0D–3D Vaporization of a Sacrificial Component (VaSC) fabrication. In this study, 1 wt% PLA/Fe2O3, PLA/CuO and PLA/Bi2O3 composites are prepared by solvent evaporation casting. Scanning Electron Microscopy (SEM) images indicate that the embedded nanoparticles are well dispersed in the polymer matrix and X-ray diffraction (XRD) verifies the crystallinity of these Metal Oxides (MOs). Thermal stability analysis of the PLA and PLA/MO composites is performed using a thermogravimetric analyzer (TGA) and Differential Scanning Calorimeter (DSC). The overall heat of combustion is measured by Microscale Combustion Calorimetry (MCC) and is found to be insensitive to the presence of nanoparticles. The overall catalytic effects of the three metal oxides have the following trend: Bi2O3 \u3e Fe2O3 \u3e CuO ≈ inert material. The PLA/Bi2O3 decomposition onset temperature (T5%) and maximum mass loss decomposition temperature (Tmax) are lowered by approximately 75 K and 100 K respectively compared to the neat PLA. The as-synthesized Bi2O3 is identified as the most effective additive among those proposed in the literature to catalyze the PLA thermal decomposition process. A numerical pyrolysis modeling tool, ThermaKin, is utilized to analyze thermogravimetric data of all the PLA/MOs and to produce a description of the decomposition kinetics, which can be utilized for modeling of thermal vaporization of these sacrificial materials

Light scattering shape diagnostics for nano-agglomerates

Motivated by light scattering experiments showing enhanced intensity of electric field aligned nano-agglomerates vs. randomly oriented nano-agglomerates, we address the theoretical basis for this effect by applying the theory of small angle Rayleigh-Debye-Gans light scattering to oriented nano-clusters generated by classical diffusion–limited cluster-cluster aggregation (DLCA). Based on more than 100 nano-clusters with 30 monomers and with 100 monomers, the ratio of the slopes of the inverse of the structure factor vs. the momentum transfer squared (S(q)ˉ¹ vs. q² ) for the partially aligned (aligned along the major axis but free to rotate about that axis) and randomly oriented clusters is well correlated with a linear fit to the shape anisotropy, defined as the ratio of the square of the major to minor principle radii of gyration. It is also shown that state of the art small-angle aerosol scattering measurements would have the angular resolution required to measure the shape anisotropy with 30 to 1000 nano-monomers with a size parameter of 0.15. For large q for nano-clusters with 30 to1000 monomers, it is shown from the simulations that S(q) for the partially aligned clusters is not proportional to q[suberscript -Df] , where D[subscript f] is the fractal dimension, as it is for randomly oriented clusters. Nano-clusters with a fixed orientation are shown to result in a structure factor with multiple peaks, which could be used to obtain more detailed information about particle structure than shape anisotropy. The measurements reported in the literature showing enhanced scattering for partially aligned soot agglomerates were for angle integrated measurements. Calculation of the integrated light scattering cross section for the same range of angles and polarization direction as the experiments indicate a significant enhancement of 70 % and 120 % for two representative aspect ratios. The smaller value overlaps with measured values of the scattering enhancement for oriented soot agglomerates in an electric field