Search results for "synthesis"
showing 10 items of 2844 documents
Reverberation still in business: Thickening and propagating micro-textures in physics-based sound modeling
2015
Artificial reverberation is usually introduced, as a digital audio effect, to give a sense of enclosing architectural space. In this paper we argue about the effectiveness and usefulness of diffusive reverberators in physically-inspired sound synthesis. Examples are given for the synthesis of textural sounds, as they emerge from solid mechanical interactions, as well as from aerodynamic and liquid phenomena.
Sketching sonic interactions by imitation-driven sound synthesis
2016
Sketching is at the core of every design activity. In visual design, pencil and paper are the preferred tools to produce sketches for their simplicity and immediacy. Analogue tools for sonic sketching do not exist yet, although voice and gesture are embodied abilities commonly exploited to communicate sound concepts. The EU project SkAT-VG aims to support vocal sketching with computeraided technologies that can be easily accessed, understood and controlled through vocal and gestural imitations. This imitation-driven sound synthesis approach is meant to overcome the ephemerality and timbral limitations of human voice and gesture, allowing to produce more refined sonic sketches and to think a…
Spectroscopic characterization of alkaline earth uranyl carbonates
2005
A series of alkaline uranyl carbonates, M[UO{sub 2}(CO{sub 3}){sub 3}].nH{sub 2}O (M=Mg{sub 2}, Ca{sub 2}, Sr{sub 2}, Ba{sub 2}, Na{sub 2}Ca, and CaMg) was synthesized and characterized by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) after nitric acid digestion, X-ray powder diffraction (XRD), and thermal analysis (TGA/DTA). The molecular structure of these compounds was characterized by extended X-ray absorption fine-structure (EXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS). Crystalline Ba{sub 2}[UO{sub 2}(CO{sub 3}){sub 3}].6H{sub 2}O was obtained for the first time. The EXAFS analysis showed that this compound consists of …
A multimodal chat-bot based information technology system
2006
The proposed system integrates chat-bot and speech recognition technologies in order to build a versatile, user-friendly, virtual assistant guide with information retrieval capabilities. The system is adaptable to the user needs of mobility being also usable on different devices (i.e. PDAs, Smartphone). The system has been implemented on a Qtek 9090 with Windows Mobile 2003 and a simulation for the cultural heritage domain is here presented.
Chemical Cartography with APOGEE: Multi-element Abundance Ratios
2019
We map the trends of elemental abundance ratios across the Galactic disk, spanning R = 3-15 kpc and midplane distance |Z|= 0-2 kpc, for 15 elements in a sample of 20,485 stars measured by the SDSS/APOGEE survey (O, Na, Mg, Al, Si, P, S, K, Ca, V, Cr, Mn, Fe, Co, Ni). Adopting Mg rather than Fe as our reference element, and separating stars into two populations based on [Fe/Mg], we find that the median trends of [X/Mg] vs. [Mg/H] in each population are nearly independent of location in the Galaxy. The full multi-element cartography can be summarized by combining these nearly universal median sequences with our measured metallicity distribution functions and the relative proportions of the lo…
Stability of stochastic nonlinear systems with state-dependent switching
2013
In this paper, the problem of stability on stochastic systems with state-dependent switching is investigated. To analyze properties of the switched system by means of Itô’s formula and Dynkin’s formula, it is critical to show switching instants being stopping times. When the given active-region set can be replaced by its interior, the local solution of the switched system is constructed by defining a series of stopping times as switching instants, and the criteria on global existence and stability of solution are presented by Lyapunov approach. For the case where the active-region set can not be replaced by its interior, the switched systems do not necessarily have solutions, thereby quasi-…
Design, synthesis and structure-activity relationship of 2-(3',4',5'-trimethoxybenzoyl)-benzo[b]furan derivatives as a novel class of inhibitors of t…
2009
The biological importance of microtubules in mitosis and cell division makes them an interesting target for the development of anticancer agents. Small molecules such as benzo[b]furans are attractive as inhibitors of tubulin polymerization. Thus, a new class of inhibitors of tubulin polymerization based on the 2-(3′,4′,5′-trimethoxybenzoyl)-benzo[b]furan molecular skeleton, with electron-donating (Me, OMe or OH) or electron-withdrawing (F, Cl and Br) substituents on the benzene ring, was synthesized and evaluated for antiproliferative activity, inhibition of tubulin polymerization and cell cycle effects. Adding a methyl group at the C-3 position resulted in increased activity. The most prom…
Structural Motifs of Alkali Metal Superbases in Non‐coordinating Solvents
2020
Abstract Lochmann–Schlosser superbases (LSB) are a standard reagent in synthetic chemistry to achieve an exchange of a proton on an organic framework with an alkali metal cation, which in turn can be replaced by a wide range of electrophilic groups. In standard examples, the deprotonating reagent consists of an equimolar mixture of n‐butyllithium and potassium t‐butoxide. However, the nature of the reactive species could not be pinned down either for this composition or for similar mixtures with comparable high reactivity. Despite the poor solubility and the fierce reactivity, some insights into this mixture were achieved by some indirect results, comparison with chemically related systems,…
Selective Formation of S4- and T-Symmetric Supramolecular Tetrahedral Cages and Helicates in Polar Media Assembled via Cooperative Action of Coordina…
2020
We report on the synthesis and self-assembly study of novel supramolecular monomers encompassing quadruple hydrogen-bonding motifs and metal coordinating 2,2’-bipyridine units. When mixed with metal ions such as Fe2+ or Zn2+, the tetrahedron cage complexes are formed in quantitative yields and full diastereoselectivity, even in highly polar acetonitrile or methanol solvents. The symmetry of the complexes obtained has been shown to depend critically on the flexibility of the ligand. Restriction of the rotation of the hydrogen-bonding unit with respect to the metal coordinating site results in a T-symmetric cage, whereas by introducing flexibility either through a methylene linker or rotating…
Antibacterial Activity of Positively and Negatively Charged Hematite (α-Fe2O3) Nanoparticles to Escherichia coli, Staphylococcus aureus and Vibrio fi…
2021
This research and work has been supported by the European Regional Development Fund within the Activity 1.1.1.2 “Post-doctoral Research Aid” of the Specific Aid Objective 1.1.1 (i.e., “to increase the research and innovative capacity of scientific institutions of Latvia and the ability to attract external financing, investing in human resources and infrastructure”) of the Operational Programme “Growth and Employment” (No. 1.1.1.2/VIAA/2/18/331).