Fractions of cellulose sulfoacetate with degrees of substitution
x
acet
= 0.9 and
y
sulf
= 1.2 with molecular mass in the range of (6–76) × 10
3
have been studied in solutions in 0.2 M NaCl using a ...set of hydrodynamic methods. The obtained matrix of the hydrodynamic parameters (intrinsic viscosity, coefficients of velocity sedimentation and translational diffusion) has allowed elucidation of the Kuhn–Mark–Houwink–Sakurada scaling relationships. Equilibrium rigidity of the cellulose sulfoacetate chains has been estimated.
A comparative analysis of the main characteristics of industrial catalysts and the innovative MAK-K catalyst in the dehydrogenation of cyclohexanol was performed. The main attention was paid to a ...comparison of MAK-K with H3-11 (BASF), which is currently the best catalyst in terms of activity and selectivity in the temperature range 220–270°C at a feedstock space velocity of 0.6–1.3 h
–1
. Both catalysts are characterized by close dependences on these parameters; MAK-K is recommended for use at lower temperatures and higher space velocities. The results of the industrial tests of MAK-K (NIAP-KATALIZATOR) loaded in an amount of 1.4 m
3
in reactor 2 of the cyclohexanol dehydrogenation shop of Shchekinoazot were also presented. The high level of activity and selectivity of MAK-K was confirmed over the period of operation (more than 2000 h), and this catalyst showed that it is highly competitive in respect of the tested samples, including foreign ones.
N-
Methyl-
N-
vinylacetamide–
N-
methyl-
N-
vinylamine copolymer of 85 : 15 mol % composition was prepared by partial hydrolysis of poly-
N-
methyl-
N-
vinylacetamide. Alkylation of the copolymer ...with dodecyl iodide yielded a water-soluble comb-shaped copolymer of
N-
methyl-
N-
vinylacetamide with
N-
methyl-
N-
vinyl-
N-
dodecylamine iodide containing hydrophobic С
12
Н
25
groups in the side chain. This copolymer was studied by methods of molecular hydrodynamics: viscometry, translational diffusion, and sedimentation velocity in dilute solutions. Hydrodynamic and molecular characteristics of the copolymers were determined, and Kuhn–Mark–Houwink–Sakurada canonical relationships were obtained.
A method of detection of single and double errors in devices used for storage and transmission of information in computerized measurement equipment systems is proposed.
The paper reviews history of studies and research areas on a frozen mummy of the woolly mammoth (
Mammuthus primigenius
) found in 2010 in Oyogoss Yar, about 30 km west of the Kondratyeva River ...mouth, northern Yakutia. Introduced to the scientific literature as the Yuka Mammoth, it became the first, partly preserved carcass of female woolly mammoth of adolescent age found in the world, which lived about 39 000 calendar years BP, during relatively warm period (MIS 3, Molotkovskian, or Leningrad Interstadials).The multidisciplinary study of Yuka by various approaches (anatomical-morphological, palynological, paleobotanical, microbiological, computer tomography, and radiocarbon dating methods) yielded fundamentally new data on this proboscidean species. The paper evaluates systematic studies of this unique specimen, from identification of its age and studies of skeletal morphology, ontogenetic development and environmental conditions to reporting the presence of viable bacteria in Yuka’s soft tissues. This paper also features the discovery of the preserved brain and analysis of its structure, as well as a revelation of unique morphology of the trunk, for the first time for this species. The paleobotanical data indicated predomination of open herbaceous landscapes during Yuka’s life. New features of the species morphology were revealed: delayed eruption of the permanent tusks (I) and different number of nail plates and phalanges on the forelegs. The presence of viable bacteria strains of
Bacillus
genus was recorded in Yuka’s tissues.
Age-related changes in the brain’s electrical activity can be caused by healthy aging and brain disorders. The ability to detect such phenomena from an electroencephalogram (EEG) is important to ...identify diseases’ latent stages. These changes appear in the brain’s background electrical activity, but the performance of cognitive or motor tasks can cause more significant signs of impairments in brain dynamics. Here, we analyze the features of multichannel EEGs in groups of healthy elderly and younger adults during hand clenching and apply two wavelet-based methods to reveal distinctions that arise with age, namely multiresolution analysis using the discrete wavelet transform, and multifractal formalism, which involves extracting the skeleton of the continuous wavelet transform. With the first method, we demonstrate that inter-group differences are established at rest and during the performance of motor tasks. With the second method, we also find similar distinctions, although the number of suitable channels and their distribution can differ. We conclude that characterization of age-related differences depends on the wavelet-based method used for EEG processing.
Nanomechanical resonators provide a versatile platform for nanoscale mass sensing and force microscopy, as well as for enhancing light‐matter interaction offering unique functionality for ...optomechanical applications. In this way, discovering new approaches for coupling light with the mechanical degrees of freedom opens the strong desire paths for further developing of nanomechanical technology. Here, the parametric optothermal modulation of hybrid nanomechanical systems consisting of carbon nanowire with a silicon nanoparticle on its top, is reported. The mechanism of the modulation is based on the periodic optical heating of the nanowire and further modulation of the elasticity parameters. Utilizing the silicon nanoparticle provides additional functionality owing to optical absorption enhanced with Mie resonance and the unique feature of optical Raman thermometry enabling optical monitoring of local temperature. It is shown that the parametric mechanism of modulation allows for a significant increase of the optomechanical coupling strength.
Parametric optothermal modulation is observed in hybrid nanomechanical system consisting of carbon nanowire with a silicon nanoparticle on its top. The mechanism is based on the periodic optical heating of the nanowire and further modulation of the elasticity parameters. Utilizing the silicon nanoparticle provides additional functionality owing to optical absorption enhanced with Mie resonance and the unique feature of optical Raman thermometry enabling optical monitoring of local temperature.
У poôomi шляхом комп ютерного моделювання до^джено процес заряджання лттчоннои акумуляторнои батареи для електромобшя вtó бездротового зарядного пристрою тдуктивно-резонансного типу. Показано, що у ...процес моделювання необхiдно враховувати одночасне протгкання двох рпномасштабних у час та пов язаних мж собою процесс, а саме короткотривалого високочастотного процесу в iнверторi зарядного пристрою ie характерним часом 10-5 с та довготривалого процесу заряджання акумулятора ie характерним часом 104 с. Прямий чисельний розрахунок одночасно цих двох процесс потребуе значних компютерних ресурав. Задля виршення цШ задачi в роботi запропоновано та реализовано в пакетi Matlab/Simulink компютерну модель та алгоритм розрахунку, згiдно з яким на першому етат у процес аналпу високочастотних процеСв в iнверторi знаходяться модифiкованi еквiваленти Теветна та Нортона для пристрою бездротовои зарядки iз врахуванням сумарних внутрштх втрат в цьому пристрои, а на другому етапi розраховуеться довготривалий процес заряджання акумуляторнои батареи. Зазначений розрахунок проводиться спочатку в режимi джерела постшного струму, використовуючи при цьому побудований еквЫалент Нортона, а потш в режимi джерела напруги, використовуючи побудований еквiвалент Теветна. Такий пiдхiд дае змогу врахувати особливостi процеСв заряджання та до^дити ефективтсть бездротовои передачi електричнои енергИ' вiд стацiонарного джерела живлення до акумулятора, що розташований на борту електромобшя. За результатами проведеного моделювання визначено, що для розробленого пристрою величина ттегрального ККД всього процесу заряджання батареи при зростант параметру акумулятора SOC вЫ 20 до 95% становить 86%. БШл. 9, рис. 8.
PDF
