Key Signature Estimation

The problem of automatic key signature detection has been the focus of much research in recent years. Previous methods of key estimation have focused on chromagrams and key profiling techniques. This paper presents a remarkably simple but effective method of estimating key signature from musical recordings. The algorithm introduces the keyogram , a concept resembling the chromagram, and is aimed for use on traditional Irish music. The keyogram is a measure of the likelihood of each possible major key signature based on a masked scoring system

Ares I-X Flight Test Validation of Control Design Tools in the Frequency-Domain

A major motivation of the Ares I-X flight test program was to Design for Data, in order to maximize the usefulness of the data recorded in support of Ares I modeling and validation of design and analysis tools. The Design for Data effort was intended to enable good post-flight characterizations of the flight control system, the vehicle structural dynamics, and also the aerodynamic characteristics of the vehicle. To extract the necessary data from the system during flight, a set of small predetermined Programmed Test Inputs (PTIs) was injected directly into the TVC signal. These PTIs were designed to excite the necessary vehicle dynamics while exhibiting a minimal impact on loads. The method is similar to common approaches in aircraft flight test programs, but with unique launch vehicle challenges due to rapidly changing states, short duration of flight, a tight flight envelope, and an inability to repeat any test. This paper documents the validation effort of the stability analysis tools to the flight data which was performed by comparing the post-flight calculated frequency response of the vehicle to the frequency response calculated by the stability analysis tools used to design and analyze the preflight models during the control design effort. The comparison between flight day frequency response and stability tool analysis for flight of the simulated vehicle shows good agreement and provides a high level of confidence in the stability analysis tools for use in any future program. This is true for both a nominal model as well as for dispersed analysis, which shows that the flight day frequency response is enveloped by the vehicle s preflight uncertainty models

Polymerisation-Induced Self-Assembly in Non-Polar Solvents

This Thesis describes the reversible addition-fragmentation chain transfer (RAFT) dispersion polymerisation of benzyl methacrylate (BzMA) in non-polar solvents. Firstly, oil-soluble poly(lauryl methacrylate) (PLMA), poly(stearyl methacrylate) (PSMA) and poly(behenyl methacrylate) (PBhMA) macromolecular chain transfer agents (macro-CTAs) are synthesised via RAFT solution polymerisation in toluene. These macro-CTAs are then chain-extended in turn with varying amounts of BzMA in industrially-sourced mineral oil or a poly(α-olefin). Polymerisation-induced self-assembly (PISA) occurs under these conditions, where the soluble BzMA monomer polymerises to form an insoluble poly(benzyl methacrylate) (PBzMA) block, thus driving the in situ formation of spheres, worms or vesicles. Subtle differences in the phase diagrams constructed for PLMA-PBzMA diblock copolymer nano-objects are observed in different solvents. In such PISA formulations, the stabiliser block DP is an important parameter, because only kinetically-trapped spheres are accessible when sufficiently long stabilisers (e.g. PLMA39, PSMA18 or PBhMA37) are used. PLMA47-PBzMA100 spheres could be prepared at copolymer concentrations up to 50% w/w solids. Importantly, a highly convenient ‘one-pot’ synthetic protocol was developed, whereby 39 nm PLMA50-PBzMA100 spheres were prepared at 30% w/w solids within 9 h starting from LMA monomer. The phase diagram for PSMA13-PBzMAx diblock copolymer nanoparticles in mineral oil indicates that the final copolymer morphologies are only weakly dependent on copolymer concentration, which enables the synthesis of pure spheres, worms or vesicles at just 5.0% w/w solids. This facilitated in situ small-angle X-ray scattering (SAXS) studies during the PISA synthesis. When targeting PSMA31-PBzMA2000 spheres, the PBzMA core diameter and aggregation number per sphere (Ns) increased monotonically during the polymerisation. When targeting PSMA13-PBzMA150 vesicles, the full range of morphologies is observed, from soluble copolymer chains to the final vesicles via intermediate spheres and worms. Transmission electron microscopy (TEM) studies indicated that vesicles are formed from worms via transient octopi and jellyfish morphologies, which is consistent with observations previously reported for aqueous PISA formulations. A combination of dynamic light scattering (DLS), TEM and both in situ and post mortem SAXS analyses confirmed that the overall vesicle dimensions are conserved as the membrane thickens, which indicates an ‘inward growth’ mechanism. This is consistent with observations recently reported for an aqueous PISA formulation and hence suggests a universal vesicle growth mechanism for all PISA formulations. Dispersions of PSMA13-PBzMA65 worms form free-standing gels at 20 °C due to multiple inter-worm contacts, but heating leads to surface plasticisation. This induces a worm-to-sphere transition and concomitant degelation, since isotropic spheres cannot form inter-particle contacts at this copolymer concentration. The worm-to-sphere transition was characterised using TEM, DLS and rheology

RAFT dispersion polymerization of glycidyl methacrylate for the synthesis of epoxy-functional block copolymer nanoparticles in mineral oil

Epoxy-functional poly(stearyl methacrylate)-poly(glycidyl methacrylate) (PSMA-PGlyMA) diblock copolymer nanoparticles are synthesized via reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of glycidyl methacrylate (GlyMA) in mineral oil at 70 °C. This efficient polymerization-induced self-assembly (PISA) formulation yields well-defined spheres of tunable diameter as confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM) studies. 1H NMR spectroscopy and gel permeation chromatography (GPC) studies indicate that such non-polar dispersions exhibit greater stability during their long-term storage at 20 °C compared to related epoxy-functional nanoparticles prepared via RAFT aqueous emulsion polymerization. Model epoxy-amine ring-opening reactions using N-methylaniline demonstrate the potential for post-polymerization functionalization of such spherical nanoparticles

Block Copolymer Nanoparticles Prepared via Polymerization-Induced Self-Assembly Provide Excellent Boundary Lubrication Performance for Next-Generation Ultralow-Viscosity Automotive Engine Oils

Core cross-linked poly(stearyl methacrylate)–poly(benzyl methacrylate)–poly(ethylene glycol dimethacrylate) [S31–B200–E20] triblock copolymer nanoparticles were synthesized directly in an industrial mineral oil via polymerization-induced self-assembly (PISA). Gel permeation chromatography analysis of the S31–B200 diblock copolymer precursor chains indicated a well-controlled reversible addition–fragmentation chain transfer dispersion polymerization, while transmission electron microscopy, dynamic light-scattering (DLS), and small-angle X-ray scattering studies indicated the formation of well-defined spheres. Moreover, DLS studies performed in THF, which is a common solvent for the S and B blocks, confirmed successful covalent stabilization because well-defined solvent-swollen spheres were obtained under such conditions. Tribology experiments using a mini-traction machine (MTM) indicated that 0.50% w/w dispersions of S31–B200–E20 spheres dramatically reduce the friction coefficient of base oil within the boundary lubrication regime. Given their efficient and straightforward PISA synthesis at high solids, such nanoparticles offer new opportunities for the formulation of next-generation ultralow-viscosity automotive engine oils

Exploring the Upper Size Limit for Sterically Stabilized Diblock Copolymer Nanoparticles Prepared by Polymerization-Induced Self-Assembly in Non-Polar Media

Reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of benzyl methacrylate is used to prepare a series of well-defined poly(stearyl methacrylate)–poly(benzyl methacrylate) (PSMA–PBzMA) diblock copolymer nanoparticles in mineral oil at 90 °C. A relatively long PSMA54 precursor acts as a steric stabilizer block and also ensures that only kinetically trapped spheres are obtained, regardless of the target degree of polymerization (DP) for the core-forming PBzMA block. This polymerization-induced self-assembly (PISA) formulation provides good control over the particle size distribution over a wide size range (24–459 nm diameter). 1H NMR spectroscopy studies confirm that high monomer conversions (≥96%) are obtained for all PISA syntheses while transmission electron microscopy and dynamic light scattering analyses show well-defined spheres with a power-law relationship between the target PBzMA DP and the mean particle diameter. Gel permeation chromatography studies indicate a gradual loss of control over the molecular weight distribution as higher DPs are targeted, but well-defined morphologies and narrow particle size distributions can be obtained for PBzMA DPs up to 3500, which corresponds to an upper particle size limit of 459 nm. Thus, these are among the largest well-defined spheres with reasonably narrow size distributions (standard deviation ≤20%) produced by any PISA formulation. Such large spheres serve as model sterically stabilized particles for analytical centrifugation studies

Long-Term Stability of n-Alkane-in-Water Pickering Nanoemulsions: Effect of Aqueous Solubility of Droplet Phase on Ostwald Ripening

High-pressure microfluidization is used to prepare a series of oil-in-water Pickering nanoemulsions using sterically-stabilized diblock copolymer nanoparticles as the Pickering emulsifier. The droplet phase comprised either n-octane, n-decane, n-dodecane, or n-tetradecane. This series of oils enabled the effect of aqueous solubility on Ostwald ripening to be studied, which is the primary instability mechanism for such nanoemulsions. Analytical centrifugation (LUMiSizer instrument) was used to evaluate the long-term stability of these Pickering nanoemulsions over time scales of weeks/months. This technique enables convenient quantification of the fraction of growing oil droplets and confirmed that using n-octane (aqueous solubility = 0.66 mg dm–3 at 20 °C) leads to instability even over relatively short time periods. However, using n-tetradecane (aqueous solubility = 0.386 μg dm–3 at 20 °C) leads to significantly improved long-term stability with respect to Ostwald ripening, with all droplets remaining below 1 μm diameter after 6 weeks storage at 20 °C. In the case of n-dodecane, the long-term stability of these new copolymer-stabilized Pickering nanoemulsions is significantly better than the silica-stabilized Pickering nanoemulsions reported in the literature by Persson et al. (Colloids Surf., A,2014,459, 48–57). This is attributed to a much greater interfacial yield stress for the former system, as recently described in the literature (see P. J. Betramo et al. Proc. Natl. Acad. Sci. U.S.A.,2017,114, 10373–10378)

Protein-, (Poly)peptide-, and Amino Acid-Based Nanostructures Prepared via Polymerization-Induced Self-Assembly

Proteins and peptides, built from precisely defined amino acid sequences, are an important class of biomolecules that play a vital role in most biological functions. Preparation of nanostructures through functionalization of natural, hydrophilic proteins/peptides with synthetic polymers or upon self-assembly of all-synthetic amphiphilic copolypept(o)ides and amino acid-containing polymers enables access to novel protein-mimicking biomaterials with superior physicochemical properties and immense biorelevant scope. In recent years, polymerization-induced self-assembly (PISA) has been established as an efficient and versatile alternative method to existing self-assembly procedures for the reproducible development of block copolymer nano-objects in situ at high concentrations and, thus, provides an ideal platform for engineering protein-inspired nanomaterials. In this review article, the different strategies employed for direct construction of protein-, (poly)peptide-, and amino acid-based nanostructures via PISA are described with particular focus on the characteristics of the developed block copolymer assemblies, as well as their utilization in various pharmaceutical and biomedical applications

AN ONBOARD HYDROGEN GENERATION METHOD BASED ON HYDRIDES AND WATER RECOVERY FOR MICRO-FUEL CELLS

poster abstractThe purpose of this paper is to conduct experiments to generate hydrogen in a fuel cell by employing hydrides and water recovery methods. Micro-proton exchange membrane fuel cells are the next generation power source for micro-scale applications. The methods presented in the paper make use of the recycled water produced from the cathode reaction to develop high energy density micro fuel cells. The method for this experiment is accomplished by utilizing oxidation-reduction reactions that take place in the cell. These reactants must be constantly replenished through an external source. This paper will introduce the methods and procedures that permit a solution to the small-scale generation of fuel and water byproduct; this is accomplished by implementing a water recovery mechanism. The experiment commenced with designing and manufacturing a Nafion membrane and a fuel cell package. From then the calcium hydride and lithium aluminum hydride was loaded. These hydrides were given controlled amounts of water vapor and the amount of gas production was measured. After the amount of gas is measured, we are able to calculate the most efficient way to receive the greatest amount of hydrogen from the cell. The objective of our experiment is to achieve a higher energy density for micro-fuel cells. Our aim is that the results of our research will replace lithium ion batteries with a high energy density fuel cell that can increase longevity as a source, and is able to be used in multiple environments including pace makers and space exploration. Multidisciplinary Undergraduate Research Institute, CRL Program

A Single Thermoresponsive Diblock Copolymer Can Form Spheres, Worms or Vesicles in Aqueous Solution

It is well‐known that the self‐assembly of AB diblock copolymers in solution can produce various morphologies depending on the relative volume fraction of each block. Recently, polymerization‐induced self‐assembly (PISA) has become widely recognized as a powerful platform technology for the rational design and efficient synthesis of a wide range of block copolymer nano‐objects. In this study, PISA is used to prepare a new thermoresponsive poly(N‐(2‐hydroxypropyl) methacrylamide)‐poly(2‐hydroxypropyl methacrylate) [PHPMAC‐PHPMA] diblock copolymer. Remarkably, TEM, rheology and SAXS studies indicate that a single copolymer composition can form well‐defined spheres (4 °C), worms (22 °C) or vesicles (50 °C) in aqueous solution. Given that the two monomer repeat units have almost identical chemical structures, this system is particularly well‐suited to theoretical analysis. Self‐consistent mean field theory suggests this rich self‐assembly behavior is the result of the greater degree of hydration of the PHPMA block at lower temperature, which is in agreement with variable temperature 1H NMR studies