bluuebunny/crossref_metadata_2025 huggingface dataset:
Recombination contributes to population diversification in the polyploid intestinal symbiont Epulopiscium sp. type B
Authors: Arroyo Francine A , Pawlowska Teresa E , Choat J Howard , Clements Kendall D , Angert Esther R
Published: January 2019

Epulopiscium sp. type B (Lachnospiraceae) is an exceptionally large, highly polyploid, intestinal symbiont of the coral reef dwelling surgeonfish Naso tonganus. These obligate anaerobes do not form mature endospores and reproduce solely through the production of multiple intracellular offspring. This likely makes them dependent on immediate transfer to a receptive host for dispersal. During reproduction, only a small proportion of Epulopiscium mother-cell DNA is inherited. To explore the impact of this unusual viviparous lifestyle on symbiont population dynamics, we investigated Epulopiscium sp. type B and their fish hosts collected over the course of two decades, at island and reef habitats near Lizard Island, Australia. Using multi-locus sequence analysis, we found that recombination plays an important role in maintaining diversity of these symbionts and yet populations exhibit linkage disequilibrium (LD). Symbiont populations showed spatial but not temporal partitioning. Surgeonfish are long-lived and capable of traveling long distances, yet the population structures of Epulopiscium suggest that adult fish tend to not roam beyond a limited locale. Codiversification analyses and traits of this partnership suggest that while symbionts are obligately dependent on their host, the host has a facultative association with Epulopiscium. We suggest that congression of unlinked markers contributes to LD estimates in this and other recombinant populations of bacteria. The findings here inform our understanding of evolutionary processes within intestinal Lachnospiraceae populations.
Novel habitat causes a shift to diurnal activity in a nocturnal species
Authors: Doody J. Sean , McHenry Colin R. , Rhind David , Clulow Simon
Published: January 2019

Plastic responses may allow individuals to survive and reproduce in novel environments, and can facilitate the establishment of viable populations. But can novel environments reveal plasticity by causing a shift in a behavior as fundamental and conspicuous as daily activity? We studied daily activity times near the invasion front of the cane toad (Rhinella marina), an invasive species that has colonized much of northern Australia. Cane toads in Australia are nocturnal, probably because diurnal activity would subject them to intolerably hot and dry conditions in the tropical savannah during the dry season. Our study can demonstrate, however, that upon reaching novel environments some toad populations became diurnal. Sandstone gorges offered cane toads novel, deeply shaded habitat. Gorges with an east-west axis (day-long northern shadow), narrow gorges and narrow sections of gorges contained toads that were primarily diurnal, while gorges with a north-south axis, wide gorges and wide sections of gorges contained mainly nocturnal toads. For example, remote camera data (1314 observations of toad activity times over 789 trap days) revealed strictly nocturnal activity at four ‘exposed’ sites (99% of 144 observations over 179 days), compared to mostly diurnal activity at a ‘shaded’ site (78% of 254 observations). Visual encounter surveys confirmed that diurnal activity occurred exclusively at shaded sites, while most nocturnal activity occurred at exposed sites. The close proximity of diurnal and nocturnal toads (4–7 km) provided compelling evidence for the abovementioned physical factors as the proximate cause of the behavioral dichotomy, and for a novel (deeply shaded gorges) environment causing the shift to diurnal activity.
Syntheses and cytotoxicity of phosphatidylcholines containing ibuprofen or naproxen moieties
Authors: Kłobucki Marek , Urbaniak Anna , Grudniewska Aleksandra , Kocbach Bartłomiej , Maciejewska Gabriela , Kiełbowicz Grzegorz , Ugorski Maciej , Wawrzeńczyk Czesław
Published: January 2019

In this study, novel phosphatidylcholines containing ibuprofen or naproxen moieties were synthesized in good yields and high purities. Under the given synthesis conditions, the attached drug moieties racemized, which resulted in the formation of phospholipid diastereomers. The comperative studies of the cytotoxicity of ibuprofen, naproxen and their phosphatidylcholine derivatives against human promyelocytic leukemia HL-60, human colon carcinoma Caco-2, and porcine epithelial intestinal IPEC-J2 cells were carried out. The results of these studies indicated that phospholipids with NSAIDs at bothsn-1 andsn-2 positions (15 and 16) were more toxic than ibuprofen or naproxen themselves, whereas 2-lysophosphatidylcholines (7 and 8) were less toxic against all tested cell lines. Phospholipids with NSAIDs atsn-1 and palmitic acid atsn-2 (9 and 10) were also less toxic against Caco-2 and normal cells (IPEC-J2).
Robustness and Information Transfer within IL-6-induced JAK/STAT Signalling
Authors: Billing Ulrike , Jetka Tomasz , Nortmann Lukas , Wundrack Nicole , Komorowski Michal , Waldherr Steffen , Schaper Fred , Dittrich Anna
Published: January 2019

Cellular communication via intracellular signalling pathways is crucial. Expression and activation of signalling proteins is heterogenous between isogenic cells of the same cell-type. However, mechanisms evolved to enable sufficient communication and to ensure cellular functions. We use information theory to clarify mechanisms facilitating IL-6-induced JAK/STAT signalling despite cell-to-cell variability. We show that different mechanisms enabling robustness against variability complement each other. Early STAT3 activation is robust as long as cytokine concentrations are low. Robustness at high cytokine concentrations is ensured by high STAT3 expression or serine phosphorylation. Later the feedback-inhibitor SOCS3 increases robustness. Channel Capacity of JAK/STAT signalling is limited by cell-to-cell variability in STAT3 expression and is affected by the same mechanisms governing robustness. Increasing STAT3 amount increases Channel Capacity and robustness, whereas increasing STAT3 tyrosine phosphorylation reduces robustness but increases Channel Capacity. In summary, we elucidate mechanisms preventing dysregulated signalling by enabling reliable JAK/STAT signalling despite cell-to-cell heterogeneity.
Field metabolic rates of teleost fishes are recorded in otolith carbonate
Authors: Chung Ming-Tsung , Trueman Clive N. , Godiksen Jane Aanestad , Holmstrup Mathias Engell , Grønkjær Peter
Published: January 2019

Field metabolic rate (FMR) is key to understanding individual and population-level responses to environmental changes, but is challenging to measure in field conditions, particularly in aquatic environments. Here we show that FMR can be estimated directly from the isotopic composition of carbon in fish otoliths (δ13Coto). We describe the relationship between δ13Cotovalues and oxygen consumption rate, and report results from laboratory experiments relating individual-level measurements of oxygen consumption rates to δ13Cotovalues in Atlantic cod (Gadus morhua). We apply our new δ13Cotometabolic proxy to existing δ13Cotodata from wild cod and four deepwater fish species to test the validity of inferred FMR estimates. The δ13Cotometabolic proxy offers a new approach to study physiological ecology in free-ranging wild fishes. Otolith-based proxies for FMR are particularly promising as they allow retrospective assessment of time-integrated, individual-level FMR throughout an individual fish’s life history.
MEP50/PRMT5-mediated methylation activates GLI1 in Hedgehog signalling through inhibition of ubiquitination by the ITCH/NUMB complex
Authors: Abe Yoshinori , Suzuki Yosuke , Kawamura Kenji , Tanaka Nobuyuki
Published: January 2019

Transcription factor GLI1 is an effecter of Hedgehog (HH) signalling and activated in a broad spectrum of cancers. However, the role of the HH-GLI1 pathway in cancer and the activation mechanism of GLI1 in HH signalling after dissociation from its inhibitor, SUFU, are not fully understood. Here, we found that GLI1 associated with the methylosome protein 50 (MEP50)/protein arginine methyltransferase 5 (PRMT5) complex and was methylated. Association of MEP50/PRMT5 with GLI1 was enhanced and expression of MEP50 and PRMT5 was activated by HH signals, suggesting their role in positive feedback regulation. Methylated GLI1 lost its ability to bind ubiquitin ligase ITCH/NUMB, resulting in nuclear accumulation and activation of GLI1. Moreover, protein expression of GLI1 was enhanced by MEP50/PRMT5 and expression of MEP50, PRMT5, and GLI1 target genes was upregulated in HH-expressing cancers. These results suggest that MEP50/PRMT5 is important for HH signal-induced GLI1 activation, especially in cancers.
Low-field1H-NMR spectroscopy for compositional analysis of multicomponent polymer systems
Authors: Chakrapani Sneha B. , Minkler Michael J. , Beckingham Bryan S.
Published: January 2019

A low-field, 60 MHz,1H NMR spectrometer yields quantitatively comparable results to 400 MHz spectrometers for the compositional analysis of multicomponent polymer systems.
Ultrasound combined with manganese-oxide nanoparticles loaded on activated carbon for extraction and pre-concentration of thymol and carvacrol in methanolic extracts of Thymus daenensis, Salvia officinalis, Stachys pilifera, Satureja khuzistanica, and mentha, and water samples
Authors: Asfaram Arash , Sadeghi Hossein , Goudarzi Alireza , Panahi Kokhdan Esmaeel , Salehpour Zeinab
Published: January 2019

A dispersive micro solid-phase extraction (DMSPE) technique was developed using manganese-oxide nanoparticles loaded on activated carbon (Mn3O4-NPs-AC) as an effective sorbent combined with ultrasound for the extraction and determination of a trace amount of thymol and carvacrol in methanolic extracts of Thymus daenensis, Salvia officinalis, Stachys pilifera, Satureja khuzistanica and mentha, and water samples.
A two-photon fluorescent probe for colorimetric and ratiometric monitoring of mercury in live cells and tissues
Authors: Chen Liyan , Park Sang Jun , Wu Di , Kim Hwan Myung , Yoon Juyoung
Published: January 2019

Owing to the extreme toxicity of mercury, methods for its selective and sensitive sensing in solutions, and in live cells and tissues are in great demand.
The effect of lattice strain on catalytic activity
Authors: Westsson Emma , Picken Stephen , Koper Ger
Published: January 2019

We report on the effect of lattice strain in three different types of core–shell electrocatalyst particles on their catalytic activity towards the oxygen reduction reaction.
Visualizing telomerase activity for tumour identification by hybridization-triggered ratiometric fluorescence
Authors: Zheng Manli , Zhang Ruilong , Tian Xiaohe , Liu Zhengjie , Zhang Zhongping
Published: January 2019

We developed a ratiometric fluorescence strategy for visualising telomerase activity to aid tumour identification by the naked eye.
Selective binding of (thio)sulfate and phosphate in water by quaternary ammonium functionalized oligo-ureas
Authors: Huang Zhe , Jia Chuandong , Wu Biao , Jansone-Popova Santa , Seipp Charles A. , Custelcean Radu
Published: January 2019

Functionalization of oligo-ureas with quaternary ammonium groups leads to water soluble receptors for selective binding of adenosine phosphates in water.
A new method to characterize underlying scratches on SiC wafers
Authors: Zhang Zesheng , Cai Hao , Gan Di , Hu Weijie , Yang Junwei , Liu Xiaozhi , Guo Yunlong , Guo Liwei , Wang Wenjun , Chen Xiaolong
Published: January 2019

The underlying scratches are revealed after quick irradiation using a picosecond pulsed laser; otherwise, they are unseen under an optical microscope.
Second inflection point of water surface tension in the deeply supercooled regime revealed by entropy anomaly and surface structure using molecular dynamics simulations
Authors: Wang Xiaoxiang , Binder Kurt , Chen Chuchu , Koop Thomas , Pöschl Ulrich , Su Hang , Cheng Yafang
Published: January 2019

The surface tension of supercooled water is of fundamental importance in physical chemistry and materials and atmospheric sciences.
Excited state dynamics of aniline homoclusters
Authors: Montero Raúl , Lamas Iker , León Iker , Fernández José A. , Longarte Asier
Published: January 2019

We have investigated the relaxation, following excitation in the 290–235 nm region, of neutral aniline homoclusters (An)n formed in a supersonic expansion by femtosecond time resolved ionization.
A variationally computed room temperature line list for AsH3
Authors: Coles Phillip A. , Yurchenko Sergei N. , Kovacich Richard P. , Hobby James , Tennyson Jonathan
Published: January 2019

Calculations are reported on the rotation–vibration energy levels of the arsine molecule with associated transition intensities.
Functionalized core–shell Ag@TiO2 nanoparticles for enhanced Raman spectroscopy: a sensitive detection method for Cu(ii) ions
Authors: Forato Florian , Talebzadeh Somayeh , Rousseau Nicolas , Mevellec Jean-Yves , Bujoli Bruno , Knight D. Andrew , Queffélec Clémence , Humbert Bernard
Published: January 2019

A shell-isolated nanoparticle enhanced surface Raman technique for detection of copper(ii).
Influence of microscopic precipitate structures on macroscopic pattern formation in reactive flows in a confined geometry
Authors: Balog Edina , Bittmann Kevin , Schwarzenberger Karin , Eckert Kerstin , De Wit Anne , Schuszter Gábor
Published: January 2019

Thanks to the coupling between chemical precipitation reactions and hydrodynamics, new dynamic phenomena may be obtained and new types of materials can be synthesized.
Fine probing the effect of replacing [PF6]−with [PF3(C2F5)3]−on the local structure and nanoscale organization of [bmim]+-based ionic liquids using MD simulation
Authors: Ebrahimi Soraya , Kowsari Mohammad H.
Published: January 2019

Probing the effect of replacing [PF6]−with [PF3(C2F5)3]−, anion flexibility, and charge scaling on the local structure, nanoscale organization, and interionic interactions of [bmim]+-based ionic liquids.
Enhanced electrochemical performance of Li–Co-BTC ternary metal–organic frameworks as cathode materials for lithium-ion batteries
Authors: Du Zhen-Qiang , Li Yong-Peng , Wang Xing-Xia , Wang Juan , Zhai Quan-Guo
Published: January 2019

A design of ternary Li–Co-benzenetricarboxylate metal–organic frameworks exhibiting top-level electrochemical performance as cathode materials for lithium-ion batteries is presented.
Unraveling the relationship between the morphologies of metal–organic frameworks and the properties of their derived carbon materials
Authors: Wu Qiao , Liang Jun , Yi Jun-Dong , Meng Dong-Li , Shi Peng-Chao , Huang Yuan-Biao , Cao Rong
Published: January 2019

The effects of the morphologies of MOF precursors on the properties of their derived carbonaceous materials are systematically studied.
Microplastic biofilm in fresh- and wastewater as a function of microparticle type and size class
Authors: Parrish Kathleen , Fahrenfeld N. L.
Published: January 2019

Microplastics are pollutants of concern in the freshwater and marine environments. These microparticles carry biofilm communities unique from the surrounding water.
Utilizing deactivated catalysts from the nitric oxide removal process for the fabrication of metal oxide/carbon supercapacitors
Authors: Lim Jiseok , Hwang Jungho , Byeon Jeong Hoon
Published: January 2019

The utilization of catalyst waste from nitric oxide removal at thermoelectric power plants for supercapacitor fabrication is proposed; the electrochemical performance of the resultant supercapacitors is comparable to that of current state-of-the-art supercapacitor systems.
Atomically dispersed Ni as the active site towards selective hydrogenation of nitroarenes
Authors: Yang Fan , Wang Minjian , Liu Wei , Yang Bin , Wang Ying , Luo Jun , Tang Yushu , Hou Liqiang , Li Yun , Li Zihui , Zhang Bing , Yang Wang , Li Yongfeng
Published: January 2019

Noble-metal-free catalytic hydrogenation of nitroarenes is achieved through the rational design of atomically dispersed Ni sites on N-doped porous carbon. The outstanding activity of the catalyst originates from the atomic dispersion of Ni active sites with a high Ni–N3 content.
Femtoliter droplet confinement ofStreptococcus pneumoniae: bacterial genetic transformation by cell–cell interaction in droplets
Authors: Lam Trinh , Brennan Martin D. , Morrison Donald A. , Eddington David T.
Published: January 2019

A droplet microfluidic device encapsulatesStreptococcus pneumoniaefor investigating cell–cell interaction and studying bacterial genetic transformation in confined microdroplets.
Fluorescence switching with subphthalocyanine-dihydroazulene dyads
Authors: Gotfredsen Henrik , Kilde Martin Drøhse , Santella Marco , Kadziola Anders , Nielsen Mogens Brøndsted
Published: January 2019

The boron subphthalocyanine (SubPc) fluorescence is reversibly modulated by photoisomerization of a covalently attached dihydroazulene (DHA) photoswitch into a vinylheptafulvene (VHF).
Controlled polymers: accessing new platforms for material synthesis
Authors: Kaligian Keri L. , Sprachman Melissa M.
Published: January 2019

Advances in polymer synthesis and characterization have laid the foundation for expanding the scope of synthetic polymer applications.
A comparative study of mechanisms of the adsorption of CO2 confined within graphene–MoS2 nanosheets: a DFT trend study
Authors: Enujekwu Francis M. , Ezeh Collins I. , George Michael W. , Xu Mengxia , Do Hainam , Zhang Yue , Zhao Haitao , Wu Tao
Published: January 2019

The space within the interlayer of 2-dimensional (2D) nanosheets provides new and intriguing confined environments for molecular interactions.
NO oxidative activity of mesoporous LaMnO3 and LaCoO3 perovskite nanoparticles by facile molten-salt synthesis
Authors: Wang Qianqian , Ma Liping
Published: January 2019

LaMnO3 and LaCoO3 perovskite nanoparticles have sprung up as the PGM-free catalysts for NO oxidation.
Preparation and characterization ofArtemisia sphaerocephalagum composite hydrogels: evaluation of rheological and release behaviour
Authors: Zhang Zongyi , Chen Tiantian , Wang Hao , Zhang Hui , Liang Junyu , Kong Weibao , Yao Jian , Wang Junlong , Zhang Ji
Published: January 2019

A sodium alginate andArtemisia sphaerocephalagum composite hydrogel prepared using a water/ethanol method shows enhanced mechanical and swelling properties.
Bifunctional iron disulfide nanoellipsoids for high energy density supercapacitor and electrocatalytic oxygen evolution applications
Authors: Sun Zhiqin , Yang Xue , Lin Huiming , Zhang Feng , Wang Qian , Qu Fengyu
Published: January 2019

FeS2, prepared using a rapid microwave assisted method, exhibits excellent electrochemical performance for supercapacitor and OER applications.
Non-fullerene acceptors inaugurating a new era of organic photovoltaic research and technology
Authors: Zhan Xiaowei , Marder Seth R.
Published: January 2019

Guest editors Xiaowei Zhan and Seth Marder introduce this Materials Chemistry Frontiers themed collection on non-fullerene acceptors for organic solar cells.
Numerical Analysis for Problems of Remote Sensing with Random Input Data
Authors: Dobronets Boris , Popova Olga
Published: January 2019

The study is devoted to the remote sensing data processing using the models with random input data. In this article we propose a new approach to calculation of functions with random arguments, which is a technique of fast computations, based on the idea of parallel computations and the application of numerical probability analysis. To calculate a function with random arguments we apply one of the basic concepts of numerical probabilistic analysis as the probabilistic extension. To implement the technique of fast computations, a new method based on parallel recursive calculations is proposed.
Forest vegetation Interaction with L-band Satellite Signals
Authors: Podoprigora Vladimir , Sorokin Anatoly
Published: January 2019

A method for calculating the electro-physical parameters of forest vegetation cover interacting with the signals of navigation satellites in the frequency bands 1.2-1.6 GHz is proposed. A technique for the experimental measurement of linear attenuation coefficient of satellite signals on test areas of canopies was developed, taking into account their calibration at the input. The proposed forest vegetation model describes the group of crowns as a system of quasi spherical "capsules", located chaotically in the air matrix. The scattering and penetration cross sections and the coefficient of linear attenuation of radio waves were calculated using the approximation of anomalous diffraction for crowns and the results of solving the diffraction problem for trunks. The effects of multiple scattering were taken into account.
Semi-supervised learning through hierarchical clustering for interactive aerospace image analysis
Authors: Rylov Sergey
Published: January 2019

A new semi-supervised classification algorithm based on the non-parametric clustering algorithm HCA is proposed. The algorithm obtains hierarchical segmentation result where additional classes that are not represented in the training samples can be found. High performance of the algorithm allows using it in interactive mode. Experimental studies confirm that the proposed algorithm provides aerospace image classification in conditions of limited number of training samples.
Satellite imagery of lengthy territories with complex configuration with the account of attitude and positioning errors
Authors: Mozgovoy Dmitriy , Svinarenko Dmitriy , Tsarev Roman , Yamskikh Tatiana
Published: January 2019

A method for monitoring attitude and positioning errors when taking satellite imagery of lengthy territories with complex configuration using an ultra-high spatial resolution optical-electronic scanner is described in the article. The results of modeling the system of automatic satellite attitude program control during the process of imagery are presented. Given these results, the impact of attitude and positioning errors during satellite imagery was estimated on the coverage percentage of the territory to be imaged.
Use of remote Earth sensing for agro-ecological estimation of soil cover structures and optimisation of agriculture in the forest-steppe zone of the Krasnoyarsk territory
Authors: Gorbunova Yuliya V. , Demyanenko Tatyana N. , Chuprova Valentina V.
Published: January 2019

The possibilities of using data of Earth remote sensing for the construction of a geomorphological profile for the purpose of agroecological assessment of soil cover patterns and subsequent land typification as a basis for the design of adaptive landscape agriculture in the Krasnoyarsk Territory are considered. The geomorphological profile illustrates the features of the relief and regularities in the distribution of soil structures with a certain set of agro-ecological conditions and limiting factors that determine the choice of agro-technologies and farming systems.
Management of the River Vedi Annual Runoff
Authors: Margaryan Varduhi , Raevich Ksenia
Published: January 2019

The article presents the following tasks for the Vedi river: to study and analyze the main physical and geographical factors determining the runoff; to collect, work out, analyze and estimate the results of factual hydro-meteorological observations of the river basin; to discover and analyze the features of intra-year distribution of the river runoff basin; to study dynamic changes of the river runoff; to create the methods of long-term forecasting of monthly and annual runoff; to create a map of spatial distribution of the river runoff. For these purposes were used the data of hydrological and meteorological stations, points of basin observations and mathematical-statistic, geographic, mapping, analytical and correlation methods.
Anomalous atmospheric temperature perturbations over seismically active regions of Europe according to satellite measurements
Authors: Sverdlik Leonid , Imashev Sanjar , Yamskikh Tatiana
Published: January 2019

An algorithm for defining temperature anomalies and the results of diagnostic studies, based on a retrospective analysis of time series of satellite data in troposphere and stratosphere over the epicenters of strong earthquakes with magnitude M > 6.0, occurring in seismically active Mediterranean region of Europe are presented. It was found out that in all cases anomalous temperature disturbances were registered 1-10 days before the main seismic event.
Framework of cloud web services for processing remote sensing data
Authors: Buchnev Alexey , Kim Pavel , Pyatkin Valery , Pyatkin Fedor , Rusin Evgeny
Published: January 2019

We consider a distributed network of cloud web services for processing satellite data, which provides data processing facilities for Earth remote sensing within SaaS model. In fact, this is a set of web services that implement the functional modules of the PlanetaMonitoring remote sensing data processing system.
Technology of 3d relief modelling based on Delaunay triangulation algorithms
Authors: Andrey Gachenko , Alexey Khmelnov
Published: January 2019

This paper represents the algorithm of superimposing underwater relief and land relief basing on heterogeneous initial data with the use of Delaunay triangulation. As a result of superimposition a qualitative 3D relief model has been created. This model can be used in generating forecasts of reservoir shoreline alterations related to hydroelectric power plant flushing. The described technology has been approbated in various practical tasks and has shown its efficiency.
The Intelligent Managerial Decision Support System for Agricultural Land Evaluation
Authors: Maglinets Yury , Raevich Ksenia , Tsibulsky Gennady
Published: January 2019

The article presents the structure of the intelligent managerial decision support system for agricultural land evaluation. The assessment problem has been a technique of defining performance indicators of productive agricultural land with account for geographical and regional features of its configuration and infestation that should be considered in making decisions during field operations. The indicator evaluation scheme is given. The specific example of evaluation is stated. Land cultivating deficiency depending on its overgrowing by trees and shrubs is shown. The results obtained are proved to be used in managing an agricultural sector of the region.
On the current density at the cathode of a vacuum arc
Authors: Nemchinsky Valerian
Published: January 2019

In view of the revival of activity on vacuum arcs, it is important to analyze the basic experimental data used in theory. Current density is one of the most important parameters. It is shown that the current density obtained by measuring postmortem arc craters could substantially underestimate the real current density.
Annealing effect on the optical and photoelectrochemical properties of lead oxide
Authors: Zerguine Wided , Abdi Djamila , Habelhames Farid , Lakhdari Meriem , Derbal-Habak Hassina , Bonnassieux Yvan , Tondelier Denis , Choi Jinwoo , Nunzi Jean Michel
Published: January 2019

Effect of the annealing oxidation time of electrodeposited lead (Pb) on the phase formation of lead oxide (PbO) films is reported. The phase structure, optical properties, size and morphology of the films were investigated by scanning electron microscopy, X-ray diffraction and UV-vis spectroscopy. The relationship between structur and photoelectrochemical properties was investigated. Thin films of PbO produced via air annealing of electrodeposited lead consist of a mixture of two phases, orthorhombic (o-PbO) and tetragonal (t-PbO), that determine the material properties and effectiveness as absorber layer in a photoelectrochemical device. The proportion of tetragonal t-PbO increases for longer heat treatments. After 40 h, the sample consists mainly of tetragonal t-PbO. The p-type semiconducting behavior of lead oxide was studied by photocurrent measurements. Different heat treatments yield variations in the ratio of tetragonal to orthorhombic lead oxide that effect on device performances, where devices with a higher content of tetragonal t-PbO show higher photocurrent than with the orthorhombic phase.
Numerical investigations of stainless steel melt motions on the surface of uranium dioxide
Authors: Usov Eduard V. , Lobanov Pavel D. , Klimonov Ilya A. , Kutlimetov Alexander E. , Butov Anton A. , Chukhno Vladimir I. , Kudashov Ivan G. , Svetonosov Alexander I. , Pribaturin Nikolay A.
Published: January 2019

The paper contains the results of numerical simulation of stainless steel melt motions on the surface of uranium dioxide. The investigations are performed for purposes of understanding of the fuel rod behavior during the core disruptive accident in the fast reactors. The systems of mass, energy and momentum conservation equations are solved to simulate melt motion on the surface of the fuel pin. Heat transfer and friction between melt and pin's surface and melt and coolant flow are taken into consideration. The dependences of mass of the melt and the features of the melt motion on coolant velocity and contact angle between melt and surface of the fuel rod are presented.
Numerical simulation on the development of periodic three-dimensional disturbances in a supersonic boundary layer
Authors: Kolosov Gleb , Semenov Alexander , Yatskikh Alexey
Published: January 2019

The results of a numerical study of the development of periodic pulsations in a supersonic boundary layer on a flat plate are presented at a Mach number of 2.5 and a unit Reynolds number of 8×106 m–1. Using the
software complex ANSYS, the complete Navier-Stokes equations were solved. Periodic mass flow disturbances with a frequency of 20 kHz were introduced into the boundary layer through a small-diameter hole on the surface of the model. Downstream the profiles of the longitudinal mass flow pulsations were recorded, and spectral analysis of the data was carried out. The main characteristics of the development of unstable disturbances in both physical and wave spaces are obtained.
Modeling of pulsed laser ablation of aluminum under the action of infrared nanosecond laser pulses
Authors: Rubtsov Nikolay , Bessmeltsev Victor , Grishin Maksim
Published: January 2019

The paper presents the results of numerical simulation of aluminum ablation process that is caused by a series of incident nanosecond pulses on a wavelength λ=1064 nm. The mechanism of normal evaporation and the effect of plasma shielding were taken into account. As a result of mathematical modeling the ablation depth was obtained. It is
shown that plasma shielding reduces the effectiveness of ablation process much more than cooling of the aluminum surface between pulses.
Secondary flows and heat transfer in shallow flow around a cylinder: LES, PIV
Authors: Palkin Egor , Shestakov Maxim , Mullyadzhanov Rustam
Published: January 2019

We report on Large-eddy simulations (LES) of flow around a short cylinder mounted in a narrow plane channel in a range of Reynolds
numbers 1000, 2000, 3750 based on the bulk velocity of the flow and diameter of the cylinder supplemented with Particle image velocimetry
(PIV) measurements for the highest considered Re. First two cases appear to be steady, however, for Re=3750 the flow becomes unsteady with the
wake dominated by periodic vortex shedding. In front of the cylinder typical horseshoe vortices are identified intensifying the skin friction and
heat transfer on the wall, while in the near wake we observe a quasiperiodic low-frequency secondary motion in the form of a pair of counterrotating
eddies developing in the transverse direction. The Karman vortex street remains the dominant pattern, but further downstream from the
cylinder the transport across the channel is associated with the secondary streamwise vortices, as also previously observed in slot jets. We observe
their impact on heat transfer and skin friction on the wall of the channel.
Experimental investigation of pressure disturbances influence on a parallel flow of viscous immiscible liquids in a T-shaped microchannel
Authors: Kovalev Alexander , Yagodnitsyna Anna
Published: January 2019

In the present paper pressure disturbances influence on parallel flow of immiscible liquids, viz. castor oil and paraffin oil, in a T-shaped microchannel with 320 um hydraulic diameter is studied experimentally. Pressure disturbances with sinusoidal and meander wave shape were applied at different frequencies and pulse ratio to the flow of carrying phase, dispersed phase or both of them simultaneously. It was shown that pressure disturbances can lead to the transition to the slug flow. A parameter taking into account signal amplitude and frequency was introduced for flow map construction. Slug length and velocity was measured for all regimes studied.
Experimental research of the process of crystallization front propagation from a cooled vertical side in a horizontal fluid layer
Authors: Mikhaylov Arseniy V. , Grishkov Vitaliy A. , Ermolayev Konstantin Y. , Berdnikov Vladimir S.
Published: January 2019

The experimental research of heptadecane’s crystallization front propagation is carried up on horizontal directed crystallization model. The temperature distributions on free surface are measured during crystallization front propagation process using thermal imager and thermocouples. The time dependence of crystallization front form was
investigated using digital video recording.
Effect of annealing time on aluminum-induced crystallization of silicon suboxide thin films
Authors: Zamchiy Alexandr , Baranov Evgeniy , Khmel Sergey , Sharafutdinov Marat
Published: January 2019

Polycrystalline silicon (poly-Si) thin films were obtained by aluminium induced crystallisation of amorphous silicon suboxide (a-SiOx, x = 0.22) via annealing of a-SiO0.22/Al bilayer structures at 550 °C for 4 - 30 h. The a-SiO0.22/Al thickness ratio was approximately 1. According optical microscopy measurements, the crystallized fraction reached the saturation value of 85% after annealing for 20 h. The further increase in the annealing time didn’t lead to an increase in this value. X-ray diffraction measurements revealed that the formed poly-Si had a strong Si (111) preferred orientation.
Thermocapillary rupture of a horizontal liquid layer on a silicon substrate
Authors: Kochkin Dmitry , Belosludtsev Valentin , Sulyaeva Veronica
Published: January 2019

This paper is an experimental study of thermocapillary breakdown phenomenon in a horizontal film of liquid placed on a silicon nonisothermal substrate. With the help of a high-speed video camera the speed of the three-phase contact line was measured during the growth of a dry spot.
Calculation of the temperature field of the material in the thermal model of laser ablation
Authors: Mkrtychev Oleg
Published: January 2019

The mechanisms of laser ablation of materials under the interaction of powerful pulsed laser radiation with a material coated with a thin film system were studied. One of the first models of such interaction of high-power laser radiation with matter was the thermal model. A onetemperature thermal model was used when considering the interaction of laser radiation with dielectrics, and a two-temperature model was used when considering the interaction of laser radiation with metals. When studying the processes of laser ablation within the framework of the thermal model, the method of moments with a special selection of the test function was chosen. Computer simulation was conducted to study the dependence of the surface temperature and the characteristic thermal length on the radiant flux. Variants with both constant and variable optophysical characteristics of the phenomenon were considered. Calculations were performed for different time ranges under different initial conditions. The results of the numerical experiment agree well with the data of other authors.
The thermal expansion coefficient of Nd-Fe-B and Sm-Co permanent magnets in the region of the Curie point
Authors: Kozlovskii Yurii , Savchenko Igor
Published: January 2019

A dilatometric study results on the linear thermal expansion coefficient (LTEC) of Nd-Fe-B and Sm-Co permanent magnets are presented. The experimental data in the temperature range 200–750 K and 293–1163 K, respectively, are obtained. The measurements were made with an error 3%. The character of the change of the linear thermal expansion coefficient in the vicinity of the Curie point is established. The critical exponents of the LTEC for magnetic phase transitions are defined.
Numerical simulation of flow in triangular minichannel
Authors: Sibiryakov Nikolay , Kabov Oleg , Belosludstev Valentin
Published: January 2019

Minichannel cooling systems show great potential for small scale electronics. In this paper we analytically and numerically investigate flow with evaporation in open triangular minichannels without upper gas flow. It models processes either in a groove or in an individual channel. From the laws of mass, momentum and energy conservation we derive equations for mean velocity and for the depth of the liquid. These equations have been solved numerically. The viscosity limits maximum fluid speed and causes the formation of dry spots. The heat flux reaches 40kW/m2 for initial liquid velocity 2 m/s. It is demonstrated that triangular or grooved channels even without upper gas flow are perspective for cooling systems.
The influence of remanent magnetization on the thermophysical properties of modern magnetically rigid materials
Authors: Savchenko Igor , Agazhanov Alibek , Samoshkin Dmitrii
Published: January 2019

Temperature dependences of thermal conductivity, thermal diffusivity, enthalpy, heat capacity, density and coefficient of linear expansion of 7 brands of modern magnetically rigid materials have been studied. The experiments were carried out by dilatometry, differential scanning calorimetry, and also by a laser pulse method for determining the thermal diffusivity. First, experiments were carried out to determine the thermophysical properties of samples with remanent magnetization. After that, the samples were demagnetized by heating to temperatures exceeding the Curie temperature, after which the thermophysical properties of the demagnetized samples were measured. The obtained results allow us to state, that the presence of remanent magnetization in the materials studied does not lead to a distinguishable change in the thermophysical properties considered in this investigation.
The changing of silicon suboxide film thickness as a result of high temperature annealing
Authors: Zamchiy Alexandr , Baranov Evgeniy
Published: January 2019

The a-SiOx:H thin films were deposited by the gas-jet electron beam plasma chemical vapor deposition method with different stoichiometry (x=0.15-1.0) for different SiH4 flow rates. The concentration of hydrogen in the films increases with the growth rate in ranges from 1.5 to 4.8 at.%. Further annealing leads to the effusion of hydrogen from the structure of the material and the compression of the structure, which leads to a reduction in the thickness for all films. X-ray diffraction measurements showed that the as-deposited films crystallized to form nc-Si about 4-8 nm in size after annealing at 1000°C.
An industrial light field camera applied for 3D velocity measurements in flow past confined cylinder
Authors: Seredkin Alexander , Shestakov Maxim , Mikhail Tokarev
Published: January 2019

Light field cameras have some advantages over classic cameras in a narrow field of application, such photography, cinematography surveillance and quality control in industry. Light field cameras have larger depth of field, compare to regular camera, but lower spatial resolution along optical axis then binocular system. However, 3D velocity measurements using light field are reasonable alternative to modern 3D PIV measurements. The nature of light field image requires extra reconstruction step which affects overall accuracy. In this article, light field PTV was compared to Tomo-PIV. Both techniques were used to measure 3D velocity fields in a turbulent wake past confined cylinder.
Investigation of flow kinematics in the structured multibed catalytic cartridge
Authors: Ezendeeva Diana , Kakaulin Sergei , Gordienko Maxim , Kabardin Ivan
Published: January 2019

The reduction of harmful substances emission into the atmosphere is very important to create compact, energy-efficient catalytic units for afterburning volatile organic compounds. A key component of such units is the catalyst cartridge. The efficiency of its operation is provided by the supply of a gas flow with a uniform velocity field. To solve the problem, the gas flow distributor and an aerodynamic stand for its testing were created. A set of air-flow blades was used to align the velocity profile before the catalyst cartridge. Also flow kinematics inside the cartridge was investigated via laser Doppler anemometry method.
Experimental study of gas inclusions dynamics in the magnetic fluid in the inhomogeneous magnetic field
Authors: Ryapolov Petr , Polunin Vyacheslav , Ivanov Anatoly , Ryabcev Kirill
Published: January 2019

The results of an experimental study of the capture, transport, and subsequent destruction of the air cavity into bubbles by the magnetic fluid in the area of the ‘magnetic vacuum’ of the annular magnet are discussed. The study was performed using video recording and recording of electromagnetic and acoustic signals.
Electrochemical ECG grinding of ceramic and tungsten sinter
Authors: Przystupa Krzysztof
Published: January 2019

The article describes a process of electrochemical grinding (ECG – Electrochemical Grinding) with a rectangular diamond grinding wheel made of ceramic – tungsten frit. Treatment of this type of material is very difficult, not only because of adverse physical properties of material itself but also due to very high requirements resulting from conditions of exploitation of a product. In discussed case, the process was carried out for a workpiece consisting of 8 tiles with a total area of about 110 cm2, fastened by screwing to a machine tool table. The article analyses a course of a chemical process, presenting chemical reactions and the course of an electrical process, closely related to a flow of electric current. Particular attention was paid to the flow of electric current as a function of changes in an active surface, understood as a geometric surface through which the electric current can flow. The results of calculation for this surface and an example of a shape of the recorded current waveform are shown. The presented results were used in construction of a control system based on maintaining a constant density of the working current.
Computerised grinding procedure for large scale crankshaft machining
Authors: Siemiątkowski Zbigniew
Published: January 2019

The paper describes sequence of machining operations that leads to the desired quality of the produced crankshaft, as well as in-situ inspection, correction and compensation procedures performed and controlled by computer. The form deviation values after correction are being compared with those obtained before. In case of crank pins, values of form deviations, and hence those of corrections, are much larger than for main journals. During the measurement, the probe collects data from 3600 points per revolution, and then averaging procedure reduces data down to 360 points. There are several algorithms for data processing available, so the operator may choose the one most appropriate. Substantial difference between out-of-roundness values of main journals and crank pivot was registered. Before form compensation, the former was between 0.01 and 0.02 mm, while the latter were in range 0.07-0.09 mm. Program of grinding is parametric, i.e. at each stage of the process all values responsible for the tool movement undergo correction. The applied computer monitoring enabled to achieve the demanded quality of grinded surface, as well as dimensions and form deviations in the tolerances set by the product specifications. Form compensation procedure enabled to reduce peak-to-peak deviation from 30.37 μm down to 8.14 μm.
Selected aspects of electricity generation in a private photovoltaic installation
Authors: Przystupa Krzysztof
Published: January 2019

The article discusses basic types of photovoltaic modules and their use in various configurations of home power plants. The astronomical conditions and estimation of intensity of solar radiation outside the Earth's atmosphere as a factor determining the scope of electricity production are described. The construction of a stationary photovoltaic installation with a capacity of 4.16kW, consisting of 16 polycrystalline photovoltaic panels cooperating with the Fronius inverter is presented. Subsequently, 7 very similar installations were analysed. It was ensured that: analysed installations were oriented southwards with a maximum 2-minute deviation, an angle of panels was similar and ranged from 35 to 38º. Installations have been installed in the same geographical area, at a short distance from one another. Energy produced was monitored during a monitoring of an electricity production process. In an empirical part of this article, energy yields obtained in 2017 are shown. Based on collected data, the analysis showing selected aspects of production, including its repeatability in analysed periods of time, was conducted. Obtained data and mathematical relationships allow to develop models for prediction and diagnostics of plant performance.
SysML-based Optimisation of Global Variables Arrangement for Visualisation in Distributed Control Systems Oriented Towards Communication Performance
Authors: Jamro Marcin , Rzonca Dariusz
Published: January 2019

Distributed Control Systems (DCSs) often perform complex and critical operations in the industry. To make work of operators easier, they are often equipped with Human-Machine Interface (HMI) panels that allow observing the current state of a process, as well as adjusting the configuration. However, when visualisation consists of several displays with many controls and a high number of calculations, it is possible to encounter some performance-related problems due to communication between a controller and the HMI panel. This problem can be limited by arranging global variables in the way that decreases the number of requests or transmitted data. The paper shows an approach of solving this problem, based on a set of SysML models that specify visualisation displays and auxiliary programs, together with involved global variables. The proposed approach can be expanded to operate as a part of a comprehensive methodology of modelling, implementation, visualisation, and testing of a DCS.
Cyclic heat release variability in a spark ignition engine under exhaust gas recirculation
Authors: Sen Asok K. , Litak Grzegorz , Wagner Robert M.
Published: January 2019

We have studied cyclic heat release variability in a spark-ignition engine under exhaust gas recirculation (EGR), using nitrogen to simulate EGR. Five EGR levels are examined. We used wavelet analysis to identify the dominant modes of fluctuation and how these modes vary in time. It is found that at a low EGR level, the heat release variations exhibit high-frequency intermittent oscillations. As the EGR level increases, the high-frequency oscillations tend to become more persistent, occurring continuously over many cycles. When the EGR level is sufficiently high, intermittent oscillations are observed at both high and low frequencies. In addition, persistent low-frequency fluctuations are present at the high EGR level. We have fitted theoretical probability models to the empirical heat release distributions. Depending on the EGR level, a three-parameter probability density function such as the generalized logistic distribution, a four-parameter distribution such as Johnson SB, or the five-parameter Wakeby distribution is found to provide a good fit. The goodness of fit of the theoretical distributions is assessed by the Kolmogorov-Smirnov (KS) test statistics. A good understanding of cyclic variability is essential to develop effective control strategies for efficient combustion.