Modular representation of the product in the knowledge base in the technological process formation

© Published under licence by IOP Publishing Ltd. The article describes the stage of engineering preparation of production, where the knowledge base is offered in the form of a matrix, which will be an active information resource for a stage of technological pre-production

Structure sensitivity of selective acetylene hydrogenation over the catalysts with shape-controlled palladium nanoparticles

The structure sensitivity of acetylene hydrogenation on catalysts with controlled shape of palladium nanoparticles was studied. Palladium particles of cubic (Pdcub), cuboctahedral (Pdco) and octahedral (Pdoct) shapes were obtained by a colloidal method. Poly(N-vinyl)pyrrolidone (PVP) was used as the stabilizer of colloidal solutions. In order to eliminate the effect of the polymer on the properties of the catalyst, PVP was removed from the surface of the particles after their transfer to the support by simultaneous treatment with ozone and UV radiation. This allowed complete cleaning of the catalyst surface from the organic stabilizer without any change in the morphology of particles. The effectiveness of this treatment method was confirmed by X-ray photoelectron spectroscopy and scanning electron microscopy. It was found experimentally that the shape of nanoparticles does not influence the catalyst selectivity, but the activity decreases in the order Pdoct > Pdco > Pdcub. Since octahedrons consist of (111) faces, the cubes contain only (100) faces, and the cuboctahedrons are composed of faces of both types, Pd111 is more active than Pd100. Calculations with the use of a statistical method showed that the ∼3-nm Pd octahedrons are nanoparticles with optimum shape and size, giving maximum catalyst activit

Capturing elements of the Nature Futures Framework through in situ place descriptions:An empirical study in urban blue locations

Human-nature interaction is in constant flux, and capturing the present perceptions and imaginaries of urban nature could facilitate the development of scenarios that ensure positive futures for both nature and humans. This paper explores the feasibility of inferring and operationalizing the three key values of the Nature Futures Framework – Nature for Society, Nature as Culture, and Nature for Nature – through the language in place descriptions and place transformation suggestions, collected in situ in 57 urban blue spaces as part of a pilot citizen science project in the Netherlands. We suggest that cross-pollination between research working towards capturing place facets in natural discourse and the Nature Futures Framework has the potential to provide effective means for a better understanding and visualization of individual and collective nature-related values hold within communities in particular places, leading to transformations of urban nature in a way that is beneficial to both humans and nature

Emerg. Infect. Dis

The multidrug-resistant (MDR) Salmonella enterica serotype Newport strain that produces CMY-2 β-lactamase(Newport MDR-AmpC) was the source of sporadic cases and outbreaks in humans in France during 2000–2005. Because this strain was not detected in food animals, it was most likely introduced into France through imported food products

Spatial beam self-cleaning and supercontinuum generation with Yb-doped multimode graded-index fiber taper based on accelerating self-imaging and dissipative landscape

We experimentally demonstrate spatial beam self-cleaning and supercontinuum generation in a tapered Ytterbium-doped multimode optical fiber with parabolic core refractive index profile when 1064 nm pulsed beams propagate from wider (122 µm) into smaller (37 µm) diameter. In the passive mode, increasing the input beam peak power above 20 kW leads to a bell-shaped output beam profile. In the active configuration, gain from the pump laser diode permits to combine beam self-cleaning with supercontinuum generation between 520-2600 nm. By taper cut-back, we observed that the dissipative landscape, i.e., a non-monotonic variation of the average beam power along the MMF, leads to modal transitions of self-cleaned beams along the taper length

Asymptotic Expansions for the Conditional Sojourn Time Distribution in the M/M/1M/M/1-PS Queue

We consider the $M/M/1$ queue with processor sharing. We study the conditional sojourn time distribution, conditioned on the customer's service requirement, in various asymptotic limits. These include large time and/or large service request, and heavy traffic, where the arrival rate is only slightly less than the service rate. The asymptotic formulas relate to, and extend, some results of Morrison \cite{MO} and Flatto \cite{FL}.Comment: 30 pages, 3 figures and 1 tabl

Electrochemical Sensors for Vanadium Determination

© Published under licence by IOP Publishing Ltd. This paper is dedicated to the problem of vanadium (V) determination by the means of voltammetry. The comparison of results obtained for two types of sensor: volume glassy-carbon electrode and screen printed carbon electrode are presented. The experimental data is recorded using the hardware and software of Novocontrol (Germany): electrochemical interface POT/GAL 15V 10A, frequency response analyzer Alpha-A, and software for data collection and data processing WinDETA. Two three-electrode cells has been studied: for the first one the bulk glassy carbon electrode, and for the second one the screen printed electrodes has been used as the working electrode. In the first case the reference electrode has been made from silver chloride and the counter electrode from steel wire. In case of the screen printed electrodes, the electrodes were placed on the same plate. The peak of vanadium (V) was obtained under the potential of 1.3 V. It was found that the growth of the vanadium concentration increases magnitude of the cathode current measured then the mentioned potential is applied. The screen printed carbon electrodes provides better sensitivity in comparison with the volume glassy-carbon electrodes due to the more explicit vanadium potential peak

Structure sensitivity of selective acetylene hydrogenation over the catalysts with shape-controlled palladium nanoparticles

The structure sensitivity of acetylene hydrogenation on catalysts with controlled shape of palladium nanoparticles was studied. Palladium particles of cubic (Pd-cub), cuboctahedral (Pd-co) and octahedral (Pd-oct) shapes were obtained by a colloidal method. Poly(N-vinyl)pyrrolidone (PVP) was used as the stabilizer of colloidal solutions. In order to eliminate the effect of the polymer on the properties of the catalyst, PVP was removed from the surface of the particles after their transfer to the support by simultaneous treatment with ozone and UV radiation. This allowed complete cleaning of the catalyst surface from the organic stabilizer without any change in the morphology of particles. The effectiveness of this treatment method was confirmed by X-ray photoelectron spectroscopy and scanning electron microscopy. It was found experimentally that the shape of nanoparticles does not influence the catalyst selectivity, but the activity decreases in the order Pd-oct > Pd-co > Pd-cub. Since octahedrons consist of (111) faces, the cubes contain only (100) faces, and the cuboctahedrons are composed of faces of both types, Pd-111 is more active than Pd-100. Calculations with the use of a statistical method showed that the similar to 3-nm Pd octahedrons are nanoparticles with optimum shape and size, giving maximum catalyst activity

On the Cauchy Problem for the Korteweg-de Vries Equation with Steplike Finite-Gap Initial Data I. Schwartz-Type Perturbations

We solve the Cauchy problem for the Korteweg-de Vries equation with initial conditions which are steplike Schwartz-type perturbations of finite-gap potentials under the assumption that the respective spectral bands either coincide or are disjoint.Comment: 29 page

Late intraocular lens dislocation. Retrospective study

Purpose. To analyze the frequency, terms and risk factors of late IOL dislocation.Material and methods. A retrospective cohort study was conducted based on archival data of 70 787 cases of the senile cataracts phacoemulsifications performed in 2002–2019 years. Statistical processing of the results and Kaplan–Meier analysis were performed using the SPSS 11.0 program (STATA).Results. 320 patients in the study group were treated for late IOL dislocation at various postoperative periods. The average age of the patients was 76.2±12.5 years at the moment of reconstruction procedure. The periods from the moment of IOL implantation to its dislocation varied from 4 months to 17.58 years, the average term was 6.95±3.67 years. IOL reposition was performed in 272 cases (85.0%) and IOL change – in 48 cases (15.0%). The leading risk factor was pseudoexfoliation syndrome detected in 239 patients (74.7%). Among other factors there was high myopia (72 patients; 22.5%), in 78 cases there were the surgery procedures between cataract surgery and IOL dislocation: glaucoma surgeries – 27 cases (8.4%), vitreal surgeries – 9 cases (2.8%), laser discission of secondary cataract – 42 cases (13.1%). The cumulative 5-, 10-, 15-, and 18- year risk of late IOL dislocation was estimated using Kaplan–Meier analysis.Conclusion. The dynamics of the number of reconstructive operations at late IOL dislocations has a tendency to increase. The average term from the IOL implantation to its dislocation was 6,95±3,67 years. The leading risk factor was pseudoexfoliation syndrome. The cumulative 5-, 10-, 15-, and 18-year risk of late IOL dislocation was 0.2; 0.7; 1.15; and 1.4%, respectively