Spectral pattern recognition of improved voice quality

The self-organizing map (a neural network) was applied to the spectral pattern recognition of voice quality in 34 subjects: 15 patients operated on because of insufficient glottal closure and 19 subjects not treated for voice disorders. The voice samples, segments of sustained /a/, were perceptually rated by six experts. A self-organized acoustic feature map was first computed from tokens of /a/ and then used for the analysis of the samples. The locations of the samples on the map were determined and the distances from a normal reference were compared with the perceptual ratings. The map locations corresponded to the degree of audible disorder: the samples judged as normal were overlapping or close to the normal reference, whereas the samples judged as dysphonie were located further away from it. The comparison of pre- and postoperative samples of the patients showed that the perceived improvement of voice quality was also detected by the map.     

Characteristics and safety of nano-sized cellulose fibrils

A finely ground fibrillated cellulose was fractionated into separate size fractions. The characteristics of the smallest size fractions were studied, and the toxicity to humans was tested as part of a safety assessment. Morphological studies performed with state-of-the-art methods, such as scanning electron microscopy and atomic force microscopy, showed that the fraction obtained consisted of long thin fibrils but also larger fibril agglomerates, and spherical particles were present. The finest fraction did not show any sub-lethal effects as assessed by RNA inhibition test in vitro, nor were there any indications of genotoxicity as tested by the Ames test in vitro. Systemic effects tested in vivo with the nematode were also absent. No cytotoxic effects were seen in the highest tolerated dose test in vitro, but some indication of cytotoxicity was observed in the total protein content test in vitro at the highest sample concentration. The significance of this toxicity test result should be addressed in relation to the other toxicity tests, in which no toxicity was observed, with special emphasis on the in vivo test. Given this, the overall toxicity analyses support the conclusion that nano-scale cellulose fibrils can be considered to be safe towards humans. However, the reason for the positive cytotoxicity test result and, in addition, the effect of the biocide used in sample preservation on the toxicity tests need to be clarified before generalizing these results and declaring nanocellulose to be unambiguously safe.     

MiniMax: What has been learned thus far

Summary A small experiment, ?MiniMax?, has been set up in the C0 intersection region of the Fermilab Tevatron to seek evidence for disoriented chiral condensates and to study other forward physics phenomena. The experiment consists of a proportional wire chamber telescope accompanied by scintillation (trigger) counters, a lead converter, and followed by an electromagnetic calorimeter. The solid angle accepted is a cone centered at pseudorapidity (η) of 4.1 and of radius (in η-ϕ space) of about 0.6. Over 2.5 million events thus far have demonstrated the successful operation of the apparatus, however to date the analysis has not progressed sufficiently to permit any conclusions concerning disoriented chiral condensates. presented byL. W. Jones Paper presented at the Special Session on very high-energy cosmic-ray interactions (superfamilies) of the XXIV International Cosmic-Ray Conference, Rome, August 28–September 8, 1995.     

Heat Transport in Unsaturated Zone Thermal Energy Storage – Analysis with Two-Phase and Single-Phase Models

We analyze a field experiment where ambient air is injected into the soil during the summer and extracted again during the winter. A multiphase model accounting for the conductive transport as well as the convective transport with the moving liquid and gas phases is used along with a more simplified single-phase model where the convective transport is due to the gas alone. The latter model also accounts for subzero wintertime temperatures. The multiphase model captures well both the seasonal variations and the actual test sequence, the main calibration being in the adjustment of medium permeabilities based on the observed pressure responses. The effect of the injection pump on the temperature and humidity of the injection air needs to be known accurately. Taking into account the humidity of the injection air explicitly instead of using humidity-corrected enthalpy values also has an effect. The effect of various humidity and specific enthalpy assumptions is of the order of 1–1.5°C, while ignoring the wintertime subzero temperatures has an effect of 1–2°C. These differences are of the same order of magnitude as the heterogeneity-introduced differences in field data. Using the simplified single-phase model typically appears to cause a difference of 1–2°C, but can yield an even higher deviation of the order of 3–4°C.     

Crystal growth, structure, and physical properties of LnCu2(Al,Si)5 (Ln = La and Ce)

LnCu(2)(Al,Si)(5) (Ln = La and Ce) were synthesized and characterized. These compounds adopt the SrAu(2)Ga(5) structure type and crystallize in the tetragonal space group P4/mmm with unit cell dimensions of a ≈ 4.2 ? and c ≈ 7.9 ?. Herein, we report the structure as obtained from single crystal X-ray diffraction. Additionally, we report the magnetic susceptibility, magnetization, resistivity, and specific heat capacity data obtained for polycrystalline samples of LnCu(2)(Al,Si)(5) (Ln = La and Ce).     

Copolymerization of 2-sulfoethyl methacrylate

Copolymers of 2-sulfoethyl methacrylate, (SEM) were prepared with ethyl methacrylate, ethyl acrylate, vinylidene chloride, and styrene in 1,2-dimethoxyethane solution with N,N′-azobisisobutyronitrile as initiator. The monomer reactivity ratios with SEM (M₁) were: vinylidene chloride, r₁ = 3.6 ± 0.5, r₂ = 0.22 ± 0.03; ethyl acrylate, r₁ = 3.2 ± 0.6, r₂ = 0.30 ± 0.05; ethyl methacrylate, r₁ = 2.0 ± 0.4, r₂ = 1.0 ± 0.1; styrene, r₁ = 0.6 ± 0.2, r₂ = 0.37 ± 0.03. The values of the copolymerization parameters calculated from the monomer reactivity ratios were e = +0.6 and Q = 1.4. Comparison of the monomer reactivities indicates that SEM is similar to ethyl methacrylate with regard to copolymerization reactivity in 1,2-dimethoxyethane solution. The sodium salt of 2-sulfoethyl methacrylate, SEM^?Na^⊕, was copolymerized with 2-hydroxyethyl methacrylate (M₂) in water solution. Reactivity ratios of r₁ = 0.7 ± 0.1 and r₂ = 1.6 ± 0.1 were obtained, indicating a lower reactivity of SEM^?Na^⊕ in water as compared to SEM in 1,2-dimethoxyethane. This decreased reactivity was attributed to greater ionic repulsion between reacting species in the aqueous medium.     

Effect of nitro groups and alkyl chain length on the negative ion tandem mass spectra of alkyl 3-hydroxy-5-(4'-nitrophenoxy) and alkyl 3-hydroxy-5-(2', 4'-dinitrophenoxy) benzoates

Tandem mass spectrometric behaviour was studied for a small combinatorial library of alkyl 3-hydroxy-5-(4'-nitrophenoxy) benzoates (A1-A5) and alkyl 3-hydroxy-5-(2', 4'-dinitrophenoxy) benzoates (B1-B5). The spectra were recorded by negative ion electrospray low-energy collision induced dissociation (CID) tandem mass spectrometry. The product ion spectra of [M - H](-) of the benzoates A1-A5 are similar, as are those of benzoates B1-B5. However, the spectra of the B series compounds differ significantly from those of the A series owing to the second electron-withdrawing nitro substituent in the B compounds. In addition, the length of the alkyl chain has an effect on the fragmentation. However, both series of compounds exhibit an abundant nitrophenoxy ion formed by the loss of 3-hydroxybenzoate. This is at m/z 138 in A1-A5 and at m/z 183 in B1-B5. A precursor ion scan of the nitrophenoxy ion provides a rapid method to identify the synthesised compounds in this type of combinatorial mixture. Copyright 1999 John Wiley & Sons, Ltd.     

Lipase-catalyzed acylation in a continuous down-flow fixed-bed reactor

The kinetic resolution of racemic 1-phenylethanol with ethyl acetate was investigated in a down-flow fixed-bed reactor operated in a continuous mode mainly at the molar ratio of 1: 3 in 400 mL toluene at 70°C. The catalytic activity of the immobilized lipase was studied by: (i) changing the flow rates, (ii) utilizing different substrate concentrations, (iii) applying step changes using ethyl acetate, ethyl benzene, acetic acid, acetophenone etc., (iv) investigating the inhibitory effect of either the desired or the stoichiometric products (R)-1-phenylethyl acetate and ethanol, respectively), (v) elucidating the effect of water on the activity and stability of the immobilized lipase. The residence time distribution and the reactor hydrodynamics were also discussed along with kinetic modelling. The results were linked to the one-pot reactions.     

Formation of a missing row reconstruction on a Cu(100) surface: An atom scale density functional theory based study

The oxygen-induced reconstruction of Cu(100) surfaces has been studied in great detail. Experimentally, missing row reconstruction occurs with an O coverage of 0.5 monolayer (ML). Several DFT-based calculations of vacancy-surface Cu pairs were performed at O coverage between 0 and 0.5 ML. No structure was identified in these calculations as being energetically favoured over the ideal Cu(100) structure. When a Cu atom (0.125 ML) was added to the system, a new energetically favourable missing row and added Cu-O-Cu row structure was found. It has been suggested that this structure is an important intermediate step towards the missing row formation. The transition from the missing and added row structure to the (2√2 × √2)R45^o-O reconstruction has the energetic requirement of very good binding sites for the Cu atoms, which can be found on the step boundaries. These results are in excellent agreement with the step edge growth and the formation of strongly anisotropic islands observed by Lahtonen et al. (J. Chem. Phys. 129 (2008) 124703).