Sorbostriction of FAS-3 microporous carbon adsorbent upon vapor adsorption from a flow of nitrogen carrier gas

Sorbostriction (adsorption-induced deformation) of FAS-3 microporous carbon adsorbent is investigated under dynamic conditions upon adsorption of benzene, carbon tetrachloride, and n-hexane vapors from a flow of nitrogen carrier gas at 573 K. The values of maximum deformation and corresponding times depend on the amount of an adsorptive. The peak time of sorbostriction curves is different for each substance under study, which makes it possible to use the effect of wavelike sorbostriction for the development of sensors for the control of qualitative and quantitative compositions of gas mixtures.     

Effect of fluid boundaries on flow around a low-aspect ratio wing

Large eddy simulation is applied to investigate flow around a finite-aspect-ratio wing in motion in a stratified fluid in different positions. It is shown that the wing position relative to a pycnocline has a considerable effect on the hydrodynamic wake development and the internal wave structure.     

A wavelet packet adaptive filtering algorithm for enhancing manatee vocalizations

Approximately a quarter of all West Indian manatee (Trichechus manatus latirostris) mortalities are attributed to collisions with watercraft. A boater warning system based on the passive acoustic detection of manatee vocalizations is one possible solution to reduce manatee-watercraft collisions. The success of such a warning system depends on effective enhancement of the vocalization signals in the presence of high levels of background noise, in particular, noise emitted from watercraft. Recent research has indicated that wavelet domain pre-processing of the noisy vocalizations is capable of significantly improving the detection ranges of passive acoustic vocalization detectors. In this paper, an adaptive denoising procedure, implemented on the wavelet packet transform coefficients obtained from the noisy vocalization signals, is investigated. The proposed denoising algorithm is shown to improve the manatee detection ranges by a factor ranging from two (minimum) to sixteen (maximum) compared to high-pass filtering alone, when evaluated using real manatee vocalization and background noise signals of varying signal-to-noise ratios (SNR). Furthermore, the proposed method is also shown to outperform a previously suggested feedback adaptive line enhancer (FALE) filter on average 3.4 dB in terms of noise suppression and 0.6 dB in terms of waveform preservation.     

Electron diffraction investigation of catalytic particles at the tips of carbon nanotubes

Catalytic nickel particles at the tips of carbon nanotubes grown under different physicochemical conditions are experimentally studied by high-energy electron diffraction. The spacings of the crystal lattice are determined. It is demonstrated that the nanoparticles consist of a supersaturated solid solution of carbon in nickel with an abnormally high carbon content.     

Plasma effects in magnetoabsorption of D<Superscript>−</Superscript> centers in quantum wells

The spectrum of magnetoabsorption of D^? centers in quantum wells is calculated with allowance for their interaction with a magnetic plasma under resonance conditions, when the distance between the Landau levels is of the same order of magnitude as the quantum energy of magnetoplasma oscillations. It is shown that splitting of Landau levels results in the fine structure of absorption lines and that the relative peak heights depend on the detuning from the resonance. The calculated frequency dependence of the absorption coefficient agrees with the experimental results.     

Kinetics and mechanism of the anionic polymerization of acrylamide monomers

The thermodynamics, kinetics, and mechanism of the anionic polymerization of a number of acrylamide monomers has been studied with the use of isothermal and scanning calorimetry, liquid chromatography, ¹H NMR and IR spectroscopy, mass spectrometry, and chemical analysis of functional groups. It has been demonstrated that the polymerization system shows the living character and the interchain exchange reactions are absent. It has been shown that N,N-diethanolacrylamide and N,N-diethanol(meth)acrylamide are uninvolved in anionic polymerization. The causes of this phenomenon have been ascertained. The products of the anionic polymerization of acrylamides are hyperbranched copolymers containing heterochain and carbochain fragments. Macromolecules contain end amide and acrylamide groups; in some macromolecules, end tert-butoxide groups of the used polymerization initiator are detected. For the products of the anionic polymerization of the acrylamide monomers under study, the temperatures of glass transition and melting have been measured.     

Effect of the porous structure of activated carbon on the adsorption kinetics of gold(I) cyanide complex

The effect the porous structure of activated carbons obtained from furfural and coconut shells has on the kinetics of [Au(CN)₂]^? ion adsorption is studied. Effective diffusion coefficients for [Au(CN)₂]^? anions in transport and adsorbing pores and mass transfer coefficients in a transport system of the pores and in microporous zones are calculated using the statistical moments of the kinetic curve.     

General and specific responsiveness of the amygdala during explicit emotion recognition in females and males

Background  

The ability to recognize emotions in facial expressions relies on an extensive neural network with the amygdala as the key node as has typically been demonstrated for the processing of fearful stimuli. A sufficient characterization of the factors influencing and modulating amygdala function, however, has not been reached now. Due to lacking or diverging results on its involvement in recognizing all or only certain negative emotions, the influence of gender or ethnicity is still under debate.     

Photometric determination of trace uranium(VI), phosphorus(V), arsenic(V), and vanadium(V) in saturated aqueous solutions of poorly soluble compounds

A procedure for extraction-photometric determination of uranium(VI) was developed and procedures for the determination of phosphorus(V), arsenic(V), and vanadium(V) were modernized. The solubility of some poorly soluble uranium compounds in aqueous solutions was determined. Deceased.