Synthesis of High Refractive Index Silicone Materials Incorporating Aromatic Moieties with Adjacent Linkage Groups for Flexible Electronic Displays

The refractive index study of copoly(arylene-siloxane)s constructed with amide, ester, or ether linkage units was conducted to synthesize a step-growth polymer for application in flexible displays. The copoly(arylene-siloxane) based materials have potential use in optical applications due to their durability, flexibility, and possession of good optical clarity properties when compared to conventional silica-filled polydimethylsiloxane-based materials. Measurement of refractive index (RI) was used as the main mode of analysis due to its direct correlation to optical clarity and material flexibility. Synthesis and characterization, including RI compiled data, was performed for six series of step-growth polymers. Effects of different linkage units, namely amides, esters, and ethers, adjacent to at least one six-membered cyclic unit (aromatic or aliphatic) were evaluated. It was observed that the refractive index of these polymers was directly proportional to the aryl content; however, the influence on RI was not equal across all types of linkage units. The highest RI copolymer, poly(4,4-methylenediphenyl diisocyanate-co-carbinol-terminated polydimethylsiloxane) (MDI-SD1.0k), yielded refractive index 1.470 and molecular weight (M_n) 16,100 g/mol; however, the copolymer poly(toluene-2,4-diisocyanate-co-carbinol-terminated polydimethylsiloxane) (TDI-SD) had the highest RI (1.462) per phenyl content. The 4,4-methylenediphenyl diisocyanate (MDI), toluene-2,4-diisocyanate (TDI), and hydrogenated methylenediphenyl-4,4-diisocyanate (HMDI) amide containing linkages best improved the refractive indices of the materials studied.     

Effect of titanium–magnesium catalyst morphology on the properties of polypropylene upon propylene polymerization in a liquid monomer

The effect of the particle size of an IK-8-21 domestic titanium-magnesium catalyst on the properties of polypropylene (PP) produced during the polymerization of propylene in a liquid monomer is studied. Catalysts with particle sizes of 20 to 64 μm are shown to have high activity and identical sensitivity to hydrogen and allow PP to be obtained with a narrow distribution of particles over size, high isotacticity, and close values of crystallinity, melting temperature, and physicomechanical properties. A slight decrease in the activity and bulk density of PP powder is observed when the average size of catalyst particles is increased from 20 to 43 μm. A more notable reduction in the activity and bulk density of PP powder is observed for catalyst with particle sizes of 62 to 64 μm. IK-8-21 catalyst is not inferior to its foreign analogues with respect to the properties of the resulting PP.     

Lactic acid production using free cells of bacteria and filamentous fungi and cells immobilized in polyvinyl alcohol cryogel: A comparative analysis of the characteristics of biocatalysts and processes

The results from studies and a comparative analysis of process characteristics are presented for lactic acid (LA) production from glucose, performed under batch conditions of the long-duration use of different biocatalyst samples comprising cells of Lactobacillus сasei bacteria and Rhizopus oryzae filamentous fungi immobilized in polyvinyl alcohol (PVA) cryogel or applied as concentrated suspensions. It is established that for LA production, the bacteria and fungi must be used in the form of PVA-cryogel-immobilized cells because their half-life in this form is considerably longer than that of concentrated cell suspensions. After 200 h of the batch use of the same immobilized cell samples, the amounts of accumulated LA were similar for both fungal (920 ± 5 g) and bacterial (895 ± 5 g) biocatalysts. The fungal biocatalyst, however, was characterized by a twice higher rate of substrate conversion to product (0.92 g LA per 1 g glucose) than the bacterial biocatalyst. The half-life of the immobilized fungal biocatalyst was 80 days (96 working cycles), ten times longer than that of the bacterial biocatalyst. A comparison of our data and the literature data demonstrated the promise of using fungal cells immobilized in PVA cryogel to produce LA: the process based on their use is superior to all known processes in its main indicators, i.e., the rate of LA conversion to glucose and the maximum accumulated concentration of the product.     

The effect of oxygen implantation on the corrosion and electrochemical properties of iron

Using the method of recording anode potentiodynamic curves in neutral and mildly alkaline borate buffer solutions, the corrosion and electrochemical behavior of iron-armco samples bombarded with oxygen ions is studied. It is shown by the method of X-ray photoelectron spectroscopy that, during such bombardment, implantation of oxygen into the surface layers of iron occurs. Therein, iron oxides of variable composition and various forms of adsorbed and absorbed oxygen are formed. These oxygen formations contribute to transfer of the iron surface to a more corrosion-resistant, passive state.     

The Effect of a Nanosize TiO<Subscript> <Emphasis Type="Italic">x</Emphasis> </Subscript> Layer on the Performance of an Organic Solar Cell

This work studies the role of a cathodic TiO_x buffer layer in operation of a photovoltaic organic solar cell (OSC) based on a photoactive layer with a bulk heterojunction. Using a liquid solution to obtain a TiO_x layer is of current interest for simplification of process technologies of successive formation of OSC layers. It is found that the optimum thickness of the TiO_x layer is 10 nm; at this thickness, the efficiency of the OSC reaches the value of 4.36%. The effect of air oxygen on the OSC samples is studied and it is found that samples with a TiO_x buffer layer undergo degradation to a lesser extent as compared to the samples with no such layer. The effect of oxygen on operation of the photovoltaic device is discussed.     

Description of methane adsorption on microporous carbon adsorbents on the range of supercritical temperatures on the basis of the Dubinin–Astakhov equation

Temperature dependences of parameters n and E are calculated according to the adsorption equation of Dubinin–Astakhov for methane adsorption on eight active carbons in the range of supercritical temperatures of 170–340 K and pressures of 0–20 MPa. At temperatures above ~240 K, characteristic adsorption energy E of methane grows linearly at an increase in temperature. The temperature coefficients of characteristic energy of methane adsorption on active carbon tend to decrease at an increase in standard characteristic adsorption energy E₀. The average value of parameter <n> for the studied adsorbents tends to grow at an increase in standard characteristic adsorption energy E₀.     

An experimental stand for investigating protective devices for high-voltage overhead lines

An experimental stand for investigating and testing lightning protection devices for aerial power lines is described. The stand is composed of an oscillation circuit modeling a power line with an industrial frequency of 50 Hz, a voltage of up to 10 kV, and a current amplitude in the circuit as high as 10 kA; a generator of short single current pulses with a voltage of up to 25 kV and a current amplitude of up to 30 kA, modeling a lightning discharge; and commutation, control, and diagnostic systems. The stand is used to investigate elements of multi-chamber arrester systems for protecting high-voltage overhead lines.     

A spectroscopic complex for time-resolved registration of plasma-jet parameters at the PF-3 facility

A spectroscopic complex for measuring the parameters of plasma jets that are generated in a facility of the plasma-focus type and the parameters of a stationary gas in which these jets propagate is described. The complex consists of an STE-1 crossed-dispersion spectrograph and a K008 streak camera, which is placed together with a notebook computer and a no-break power unit inside a shielding box for protection against electromagnetic noise. The K008 camera is equipped with an additional image intensifier on the basis of an EP-10 image-converter tube. The spectrum image is recorded with a standard SU-05M video camera and processed with the Klen-5m dedicated program, which automatically corrects the distortion and scan nonuniformities and subtracts regular noise. The complex makes it possible to obtain the time dependences of the intensities and shapes of several spectral lines in a range of scans from a few nanoseconds to milliseconds and to promptly tune the system to the required spectral ranges. Within one discharge of the facility, a digital image of the time-integral spectrum is simultaneously recorded in the entire visible region.     

Data acquisition system of the OKA experiment

A data acquisition system of the OKA experiment on studying rare kaon decays on the U-70 accelerator is described. The basis of the blocked data acquisition system was the high-speed multichannel information system MISS with autonomous controllers that read out the front-end electronics in the sequential data reading mode and buffering data during the accelerator burst. Data stored in the buffer memory are read out and processed at the end of the accelerator burst. The DATE package builds subevents from event fragments and events from subevents via the event building network. The event building network with the star topology is made with 1GbE-interfaces and 24 × 1 Gb E-switch. The GlusterFS cluster file system underlies the distributed storage system.     

LED magneto-optical ellipsometer with the switching of orthogonal polarization states

A light-emitting diode (LED) magneto-optical ellipsometer with the switching of orthogonal polarization states is described. The distinctive features of the ellipsometer are the implementation of the maximally deep azimuthal modulation, application of two-channel detector, use of a set of LEDs ensuring a high signal-to-noise ratio, and the absence of moving polarization elements. These features have substantially increased the precision of measurements of ellipsometric parameters ψ and Δ for ferromagnetic materials and their changes (δψ and δΔ) in the magnetic field, which are connected for the transverse Kerr configuration by simple relations with magneto-optical parameters. At wavelengths of 365, 372, 390, 405, 420, and 465 nm, the precision of ψ-δψ and Δ-δΔ measurements of metal films is about 0.0003° and 0.001°, respectively. The spectral resolution is 4 nm; the minimal measurement time of ψ and Δ in the continuous spectral range of 270–1000 nm is 20 s; the magnetic field is varied from–2500 to +2500 Oe; and the step of the magnetic field setting is 0.5 Oe.