bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective modification of Ti6Al4V surfaces for biomedical applications
Authors: Rodriguez Gabriela Melo , Bowen James , Zelzer Mischa , Stamboulis Artemis
Published: May 2020

The surface of a medical implant is required to interact favourably with ions, biomolecules and cells in vivo, commonly resulting in the formation of the extracellular matrix.
Europium oxide nanorod-reduced graphene oxide nanocomposites towards supercapacitors
Authors: Aryanrad Parisa , Naderi Hamid Reza , Kohan Elmira , Ganjali Mohammad Reza , Baghernejad Masoud , Shiralizadeh Dezfuli Amin
Published: May 2020

Fast charge/discharge cycles are necessary for supercapacitors applied in vehicles including, buses, cars and elevators.
A tetrahedral DNA nanostructure-decorated electrochemical platform for simple and ultrasensitive EGFR genotyping of plasma ctDNA
Authors: Wang Xuyao , Wu Jianping , Mao Weilin , He Xia , Ruan Liming , Zhu Junlan , Shu Peng , Zhang Zhenqi , Jiang Bitao , Zhang Xingguo
Published: May 2020

In this study, we propose an on-site electrochemical platform for sensitive simultaneous genotyping of the two major EGFR mutations (19del and L858R) through plasma ctDNA based on tetrahedral DNA nanostructure decorated screen-printed electrodes.
Facile dispersive solid-phase extraction based on humic acid for the determination of aflatoxins in various edible oils
Authors: Liu Ping , Liao Yan-Hua , Zheng Hao-Bo , Tang Yang
Published: May 2020

Aflatoxins (AFs), as the secondary metabolites produced by some toxigenic fungi of Aspergillus species, are well known to be extremely harmful to humans and animals because of their high toxicity, mutagenicity, carcinogenicity, and teratogenicity.
Miniaturized QuEChERS method for determination of 97 pesticide residues in wine by ultra-high performance liquid chromatography coupled with tandem mass spectrometry
Authors: Bernardi Gabrieli , Kemmerich Magali , Adaime Martha B. , Prestes Osmar D. , Zanella Renato
Published: May 2020

A miniaturized sample preparation method was developed and validated for the multiresidue determination of 97 pesticides in wine samples.
Coupling PEG-LZM polymer networks with polyphenols yields suturable biohydrogels for tissue patching
Authors: Tan Haoqi , Sun Junjie , Jin Dawei , Song Jialin , Lei Miao , Antoshin Artem , Chen Xin , Yin Meng , Qu Xue , Liu Changsheng
Published: May 2020

A highly tough hydrogel tissue patch based on multiple non-covalent interactions between polyphenols and PEG-LZM networks has multiple biological activities.
Liquid metal exfoliation of two dimensional polydopamine nanosheets for templated assembly of noble metal nanoparticles
Authors: Liu Yong , Li Juanjuan , Zhang Wei
Published: May 2020

A liquid metal-assisted exfoliation strategy is developed for synthesizing two-dimensional polydopamine nanosheets.
Quantifying the hygroscopic properties of cyclodextrin containing aerosol for drug delivery to the lungs
Authors: Day C. P. F. , Miloserdov A. , Wildish-Jones K. , Pearson E. , Carruthers A. E.
Published: May 2020

The hygroscopic growth factor for individual aqueous 2-hydroxypropyl β-cyclodextrin droplets has been measured and compared with dynamic vapour sorption measurements.
Phosphine-catalyzed [3 + 2] annulation of 2-aminoacrylates with allenoates and mechanistic studies
Authors: Wu Xiao-Yun , Gui Hou-Ze , Jangra Harish , Wei Yin , Zipse Hendrik , Shi Min
Published: May 2020

A phosphine catalyzed formal [3 + 2] annulation was disclosed, affording 3-pyrrolines containing an amino quaternary stereogenic center in good to excellent yields. The catalytic mechanism was investigated by DFT and kinetic studies.
A transversal low-cost pre-metallation strategy enabling ultrafast and stable metal ion capacitor technologies
Authors: Arnaiz María , Shanmukaraj Devaraj , Carriazo Daniel , Bhattacharjya Dhrubajyoti , Villaverde Aitor , Armand Michel , Ajuria Jon
Published: May 2020

A low-cost pre-metallation strategy based on inorganic sacrificial salts that decompose on the first charge.
Interactions of ferrous iron with clay mineral surfaces during sorption and subsequent oxidation
Authors: Van Groeningen Natacha , ThomasArrigo Laurel K. , Byrne James M. , Kappler Andreas , Christl Iso , Kretzschmar Ruben
Published: May 2020

Under anoxic conditions, clay minerals sorb dissolved Fe(ii) predominantly by forming surface precipitates, which transform into Fe(iii)-phases upon aeration.
The milk macromolecular peptide: preparation and evaluation of antihypertensive activity in rats
Authors: Cui Pengfei , Yang Xue , Li Yunliang , Liang Qiufang , Wang Yucheng , Lu Feng , Owusu John , Huang Shanfen , Ren Xiaofeng , Ma Haile
Published: May 2020

In order to avoid the discomfort of digesting milk protein and make full use of the gastrointestinal digestive function, a milk macromolecular peptide was prepared with ACE inhibitory activity after gastrointestinal digestion as the index.
Deciphering calcium-binding behaviors of casein phosphopeptides by experimental approaches and molecular simulation
Authors: Luo Minna , Xiao Jie , Sun Shengwei , Cui Fengchao , Liu Guo , Li Wei , Li Yunqi , Cao Yong
Published: May 2020

Deciphering calcium-binding sites of CPPs and three calcium-binding modes with experimental methods and molecular simulation.
Electrochemical oxidative C(sp3)–H azolation of lactams under mild conditions
Authors: Wan Zhaohua , Wang Dan , Yang Zixuan , Zhang Heng , Wang Shengchun , Lei Aiwen
Published: May 2020

A method for electrochemical oxidative direct C(sp3)–H azolation under metal catalyst-free and external chemical oxidant-free conditions.
Charge-density induced discrimination of halides with a rigid dinuclear copper(ii) complex
Authors: Rhaman Md Mhahabubur , Hasan Mohammad H. , Ali Zulfikhar A. , Powell Douglas R. , Tandon Ritesh , Wong Bryan M. , Hossain Md. Alamgir
Published: May 2020

A rigid dinuclear copper(ii) complex L based on furan spacers has been synthesized and studied for its binding interactions with halides by colorimetric studies, UV-vis titration, and density functional theory (DFT) calculations.
Introduction to molecular engineering for water technologies
Authors: Darling Seth B. , Yang Hao-Cheng
Published: May 2020

Guest Editors Seth Darling and Hao-Cheng Yang introduce the Molecular Systems Design & Engineering themed collection on molecular engineering for water technologies.
Cellular architecture response to aspect ratio tunable nanoarrays
Authors: Dai Jing , Gong Jinkang , Kong Na , Yao Yuan
Published: May 2020

A series of aspect ratio tunable nanoarrays through a metal-assisted chemical etching method was fabricated to explore cell architecture and physiological behaviors of human pancreatic cancer response to diverse nanoarrays.
Wrinkle-induced highly conductive channels in graphene on SiO2/Si substrates
Authors: Ma Rui-Song , Ma Jiajun , Yan Jiahao , Wu Liangmei , Guo Wei , Wang Shuai , Huan Qing , Bao Lihong , Pantelides Sokrates T. , Gao Hong-Jun
Published: May 2020

This work helps to pave the way toward practical applications with wrinkled graphene as electrodes in electrical devices.
Facile fabrication of sponge-like porous micropillar arrays via an electrochemical process
Authors: Zheng Deyin , Choi Chang-Hwan , Zhao Xin , Sun Guangyi
Published: May 2020

Highly ordered and aligned pore structures perpendicular to the exposed surfaces are achieved on the surfaces of 3D Si microstructures.
Multi-praseodymium-and-tungsten bridging octameric tellurotungstate and its 2D honeycomb composite film for detecting estrogen
Authors: Zhang Yan , Jiang Jun , Liu Yifan , Li Pan , Liu Yong , Chen Lijuan , Zhao Junwei
Published: May 2020

A novel multi-praseodymium-and-tungsten bridging octameric tellurotungstate was prepared and successfully utilized to construct Au-modified aptamer biosensors toward the detection of 17β-estradiol.
Hybrid phase 1T/2H-MoS2with controllable 1T concentration and its promoted hydrogen evolution reaction
Authors: Zhang Yuxiao , Kuwahara Yasutaka , Mori Kohsuke , Louis Catherine , Yamashita Hiromi
Published: May 2020

1T concentration controllable 1T/2H-MoS2with enhanced electrochemical hydrogen evolution reaction performance has been synthesized.
A copper(i)-catalyzed azide–alkyne click chemistry approach towards multifunctional two-way shape-memory actuators
Authors: Liu Zhong-Cheng , Zuo Bo , Lu Hai-Feng , Wang Meng , Huang Shuai , Chen Xu-Man , Lin Bao-Ping , Yang Hong
Published: May 2020

Here we report a copper(i)-catalyzed azide–alkyne click chemistry approach towards the fabrication of main chain liquid crystal elastomers.
Mechanism of oxygen vacancy assisted water-splitting of LaMnO3: inorganic perovskite prediction for fast solar thermochemical H2 production
Authors: Fu Mingkai , Xu Huajun , Li Xin
Published: May 2020

The mechanism of water-splitting and H2 production around the oxygen vacancy site of the LaMnO3 defective surface is explored for the purpose of quick identification of kinetically favorable dopants such as Mo.
Boosting the piezocatalytic performance of Bi2WO6 nanosheets towards the degradation of organic pollutants
Authors: Hao Aize , Ning Xueer , Cao Yali , Xie Jing , Jia Dianzeng
Published: May 2020

Bi2WO6 nanosheets are shown to demonstrate excellent piezocatalytic performance, and insight into the piezocatalytic mechanism is provided.
Mechanochemical approach to synthesize citric acid-soluble fertilizer of dittmarite (NH4MgPO4·H2O) from talc/NH4H2PO4 mixture
Authors: Tan Yonghao , Sha Lin , Yu Nengkui , Yang Zhengshuo , Qu Jun , Xu Zhigao
Published: May 2020

Dittmarite synthesis by a mechanochemical route for application as a citric acid-soluble fertilizer.
The synergistic influence of polyethyleneimine-grafted graphene oxide and iodide for the protection of steel in acidizing conditions
Authors: Ansari K. R. , Chauhan Dheeraj Singh , Quraishi M. A. , Adesina A. Y. , Saleh Tawfik A.
Published: May 2020

Herein, graphene oxide (GO) was chemically functionalized with polyethyleneimine (PEI) in a single step to obtain PEI-GO, which was characterized via FTIR spectroscopy, SEM, and TEM.
Computational study on the polymerization reaction ofd-aminopeptidase for the synthesis ofd-peptides
Authors: Gimenez-Dejoz Joan , Tsuchiya Kousuke , Tateishi Ayaka , Motoda Yoko , Kigawa Takanori , Asano Yasuhisa , Numata Keiji
Published: May 2020

We studied the molecular mechanism ofd-aminopeptidase for the synthesis of polypeptides incorporatingd-amino acids.
Elongated conductive structures in detonation soot of high explosives
Authors: Satonkina Nataliya P. , Ershov Alexander P. , Kashkarov Alexey O. , Rubtsov Ivan A.
Published: May 2020

Micrographs of transmission electron microscopy of saved detonation products of benzotrifuroxane at different scales.
A highly sensitive, selective and renewable carbon paste electrode based on a unique acyclic diamide ionophore for the potentiometric determination of lead ions in polluted water samples
Authors: Zayed M. A. , Mahmoud Walaa H. , Abbas Ashraf A. , Ali Aya E. , Mohamed Gehad G.
Published: May 2020

Due to the toxicity of lead(ii) to all living organisms destroying the central nervous system and leading to circulatory system and brain disorders, the development of effective and selective lead(ii) ionophores for its detection is very important.
Boosting performances of triboelectric nanogenerators by optimizing dielectric properties and thickness of electrification layer
Authors: Kang Xiaofang , Pan Chongxiang , Chen Yanghui , Pu Xiong
Published: May 2020

Enhanced output performances of a triboelectric nanogenerator (TENG) are achieved by optimizing the high-dielectric-constant filler content in the electrification layer and decreasing its thickness.
Preparation of phosphorus-doped porous carbon for high performance supercapacitors by one-step carbonization
Authors: Lin Guanfeng , Wang Qiong , Yang Xuan , Cai Zhenghan , Xiong Yongzhi , Huang Biao
Published: May 2020

P-doped porous carbon can be prepared by one-step carbonization using biomass sawdust impregnated with a small amount of phosphoric acid.
A poly(allylamine hydrochloride)/poly(styrene sulfonate) microcapsule-coated cotton fabric for stimulus-responsive textiles
Authors: Zhao Zhiqi , Li Qiujin , Gong Jixian , Li Zheng , Zhang Jianfei
Published: May 2020

This study reports a stimulus-responsive fabric incorporating a combination of microcapsules, containing polyelectrolytes poly(allylamine hydrochloride) (PAH) and poly(styrene sulfonate) sodium salt (PSS), formed via a layer-by-layer (LBL) approach.
Cobalt–carbon/silica nanocomposites prepared by pyrolysis of a cobalt 2,2′-bipyridine terephthalate complex for remediation of cationic dyes
Authors: Alotaibi Nusaybah , Hammud Hassan H. , Karnati Ranjith Kumar , Hussain Syed Ghazanfar , Mazher Javed , Prakasam Thirumurugan
Published: May 2020

A cobalt–carbon@silica nanocomposite was synthesized from a cobalt 2,2′-bipyridine terephthalate complex and its adsorption behavior towards crystal violet dye was tested using batch and column techniques.
Electrochemical reduction of CO2to ethylene on Cu/CuxO-GO composites in aqueous solution
Authors: Rashid Nusrat , Bhat Mohsin Ahmad , Goutam U. K. , Ingole Pravin Popinand
Published: May 2020

Herein, we present fabrication of graphene oxide supported Cu/CuxO nano-electrodeposits which efficiently and selectively can electroreduce CO2into ethylene with a faradaic efficiency of 34% and conversion rate of 194 mmol g−1h−1at −0.985 Vvs.RHE.
Correction: Synthesis of α,β-unsaturated esters of perfluoropolyalkylethers (PFPAEs) based on hexafluoropropylene oxide units for photopolymerization
Authors: Bonneaud Céline , Decostanzi Mélanie , Burgess Julia , Trusiano Giuseppe , Burgess Trevor , Bongiovanni Roberta , Joly-Duhamel Christine , Friesen Chadron M.
Published: May 2020

Correction for ‘Synthesis of α,β-unsaturated esters of perfluoropolyalkylethers (PFPAEs) based on hexafluoropropylene oxide units for photopolymerization’ by Céline Bonneaud et al., RSC Adv., 2018, 8, 32664–32671.
Correction: Role of polysilicon in poly-Si/SiOx passivating contacts for high-efficiency silicon solar cells
Authors: Park HyunJung , Bae Soohyun , Park Se Jin , Hyun Ji Yeon , Lee Chang Hyun , Choi Dongjin , Kang Dongkyun , Han Hyebin , Kang Yoonmook , Lee Hae-Seok , Kim Donghwan
Published: May 2020

Correction for ‘Role of polysilicon in poly-Si/SiOx passivating contacts for high-efficiency silicon solar cells’ by HyunJung Park et al., RSC Adv., 2019, 9, 23261–23266. DOI: 10.1039/c9ra03560e
Determination of protein–ligand binding modes using fast multi-dimensional NMR with hyperpolarization
Authors: Wang Yunyi , Kim Jihyun , Hilty Christian
Published: May 2020

The structure of a ligand bound to a protein is determined from fast pseudo-3D NMR spectroscopy with transfer of hyperpolarization.
Regioselective molybdenum-catalyzed allylic substitution of tertiary allylic electrophiles: methodology development and applications
Authors: Salman Muhammad , Xu Yaoyao , Khan Shahid , Zhang Junjie , Khan Ajmal
Published: May 2020

The first general example of Mo-catalyzed allylic sulfonylation of tertiary allylic electrophile provides an efficient way to forge sulfone moieties, and providing ample opportunities for further transformation through traditional Suzuki cross-coupling.
Quinone methide dimers lacking labile hydrogen atoms are surprisingly excellent radical-trapping antioxidants
Authors: Raycroft Mark A. R. , Chauvin Jean-Philippe R. , Galliher Matthew S. , Romero Kevin J. , Stephenson Corey R. J. , Pratt Derek A.
Published: May 2020

Quinone method dimers, (bio)synthetic intermediates en route to many naturally products derived from resveratrol, are potent radical-trapping antioxidants, besting the phenols from which they are derived and to which they can be converted.
Insight into sulfur-rich selenium sulfide/pyrolyzed polyacrylonitrile cathodes for Li–S batteries
Authors: Zhang Wei , Li Shuping , Wang Lihui , Wang Xumin , Xie Jia
Published: May 2020

The facile synthesis of sulfur-rich SexS1−x@pPAN composites and their optimal electrochemical performance in Li–S batteries are achieved.
Simulation of interpenetrating networks microgel synthesis
Authors: Rudyak Vladimir Yu. , Kozhunova Elena Yu. , Chertovich Alexander V.
Published: May 2020

In silico template synthesis of IPN microgels demonstrated the possibility of the formation of shell-corona structures in selective solvents.
Correlation of the hierarchical structure with rheological behavior of polypseudorotaxane gel composed of pluronic and β-cyclodextrin
Authors: Shih Kuo-Chih , Su Chien-You , Chang Shing-Yun , Jensen Grethe , Hua Chi-Chung , Nieh Mu-Ping , Lai Hsi-Mei
Published: May 2020

The reorganization of meso-structured “grains” composed of multiple lamellar stacks strung by F108 results in thixotropic properties.
A novel integrated Cr(vi) adsorption–photoreduction system using MOF@polymer composite beads
Authors: Valizadeh Bardiya , Nguyen Tu N. , Kampouri Stavroula , Sun Daniel T. , Mensi Mounir D. , Stylianou Kyriakos , Smit Berend , Queen Wendy L.
Published: May 2020

Herein, a novel integrated adsorption–photoreduction system, which captures highly mobile and toxic hexavalent chromium (Cr(vi)) from real-world water samples and reduces it to less mobile and benign Cr(iii) species, was designed.
Efficiency enhancement in an inverted organic light-emitting device with a TiO2 electron injection layer through interfacial engineering
Authors: Zang Chunxiu , Wang Hui , Liu Shihao , Guo Wenbin , Zhang Letian , Xie Wenfa
Published: May 2020

The performance of IOLEDs with a TiO2 EIL is significantly improved by improving electron injection through a stepped energy level interlayer and reducing quenching.
Controllable tuning of Fabry–Perot cavities via laser printing
Authors: Ding Tao
Published: May 2020

Facile and controllable tuning of Fabry–Perot cavities is realised via photoablation of polystyrene medium, which generates different colours due to the change of local refractive index.
Non‐linear analytical modelling and optimisation of a 12/8 rotor excited flux‐switching machine
Authors: Mohammadi Ajamloo Akbar , Ghaheri Aghil , Shirzad Hossein , Afjei Ebrahim
Published: May 2020

Rotor excited flux‐switching permanent magnet machines (REFSPMs) have been recently introduced exhibiting high power density and low permanent magnet consumption. Despite the advantages, 12/8 configuration of REFSPM has an intrinsic unbalanced voltage waveform due to the existence of even‐order harmonics. Aiming to improve the machine voltage THD, using notches on the rotor segments is proposed. To study the effects of the rotor notch on machine performance with low computational time, the non‐linear magnetic equivalent circuit is developed taking into account the effects of fringing fluxes, iron saturation, and rotor transition. An optimisation procedure based on Taguchi method is applied to minimise the voltage THD value taking the effects of uncontrollable factors into account. Finally, the REFSPM is prototyped and the measured results are compared with the analytical and numerical results.
Novel non‐isolated high step‐up converter with fewer passive devices and low voltage stress of power switches
Authors: Yang Ningrui , Zeng Jun , Hu Renjun , Liu Junfeng
Published: May 2020

High step‐up, high‐efficiency and cost‐effective dc–dc converters with high power density, as an interface to boost the low voltage of alternative sources to the utility voltage level, are an important part of renewable energy systems. In this study, a novel high step‐up converter is proposed with a switched‐capacitor. By introducing the switched‐capacitor unit in the converter, the voltage of the switched‐capacitor is coupled into the charging circuit of the input filter‐inductor. Thus, the boost factor can be enlarged up to (1 − 2D) and the problem of the inrush current can be avoided due to the filter inductor. By replacing the filter inductor with the voltage multiplier unit, the boost coefficient of one coupled inductor voltage multiplier is increased to 2n and the voltage stress of the power switch is significantly reduced. Moreover, the energy of the leakage inductor is recycled by the switched‐capacitor with the reduction of the voltage spike and the switches’ stress. The working principle and the steady‐state characteristics are analysed in detail in this study, and a comparison is made between the proposed converter and other high step‐up converters. The experimental results based on a 200 W 20 to 200 V prototype verify the correctness and the feasibility.
The Herschel view of the dense core population in the Ophiuchus molecular cloud
Authors: Ladjelate B. , André Ph. , Könyves V. , Ward-Thompson D. , Men’shchikov A. , Bracco A. , Palmeirim P. , Roy A. , Shimajiri Y. , Kirk J. M. , Arzoumanian D. , Benedettini M. , Di Francesco J. , Fiorellino E. , Schneider N. , Pezzuto S. , Motte F. ,   the Herschel Gould Belt Survey Team
Published: May 2020

Context. Herschel observations of nearby clouds in the Gould Belt support a paradigm for low-mass star formation, starting with the generation of molecular filaments, followed by filament fragmentation, and the concentration of mass into self-gravitating prestellar cores. In the case of the Ophiuchus molecular complex, a rich star formation activity has been documented for many years inside the clumps of L1688, the main and densest cloud of the complex, and in the more quiescent twin cloud L1689 thanks to extensive surveys at infrared and other wavelengths.

Aims. With the unique far-infrared and submillimeter continuum imaging capabilities of the Herschel Space observatory, the closeby (d = 139 pc) Ophiuchus cloud was extensively mapped at five wavelengths from 70 to 500 μm with the aim of providing a complete census of dense cores in this region, including unbound starless cores, bound prestellar cores, and protostellar cores.

Methods. Taking full advantage of the high dynamic range and multi-wavelength nature of the Herschel data, we used the multi-scale decomposition algorithms getsources and getfilaments to identify an essentially complete sample of dense cores and filaments in the cloud and study their properties.

Results. The densest clouds of the Ophiuchus complex, L1688 and L1689, which thus far are only indirectly described as filamentary regions owing to the spatial distribution of their young stellar objects, are now confirmed to be dominated by filamentary structures. The tight correlation observed between prestellar cores and filamentary structures in L1688 and L1689 supports the view that solar-type star formation occurs primarily in dense filaments. While the sub clouds of the complex show some disparities, L1689 being apparently less efficient than L1688 at forming stars when considering their total mass budgets, both sub clouds share almost the same prestellar core formation efficiency in dense molecular gas. We also find evidence in the Herschel data for a remarkable concentric geometrical configuration in L1688 which is dominated by up to three arc-like compression fronts and has presumably been created by shockwave events emanating from the Sco OB2 association, including the neighboring massive (O9V) star σ Sco.

Conclusions. Our Herschel study of the well-documented Ophiuchus region has allowed us to further analyze the influence of several early-type (OB) stars surrounding the complex, thus providing positive feedback and enhancing star formation activity in the dense central part of the region, L1688.
Formulation of methods reducing landslide phenomena and the collapse of career slopes during open-pit mining
Authors: Begalinov Abdrakhman , Khomiakov Vitalii , Serdaliyev Yerdulla , Iskakov Yerkin , Zhanbolatov Aibar
Published: May 2020

In this article, methods of reducing landslide phenomena and collapse of career of slopes, in the extraction of minerals with the open-pit mining approach are set out. The ways of uncovering upper argillaceous acclivities with the creation of buttresses made from rocky minerals are suggested. Also, technological frameworks of the establishment of acclivities of benches in primary resources, with preliminary conduct of the research on the deformation of the minerals from the drilling-andblasting activities are offered. On the basis of the dynamic processes of blasting and resistance of the massif to the breakage, there is a formula offered, for determining the rate of fracturing, and the methodology of calculation of the specific charge of the blasting substance, including and excluding the fracturing of the massif is substantiated. The technique of defining the parameters of buttresses, used in strengthening of the acclivities, piled with unstable argillaceous and friable minerals, is also suggested.
Investigation of oscillations of platform on isotropic supports excited by a pendulum
Authors: Filimonikhin Gennadiy , Yatsun Volodymyr , Filimonikhina Irina
Published: May 2020

Within the framework of a flat model, steady-state modes of motion of a system composed of a platform on isotropic elastic-viscous supports, a shaft on a platform, and a pendulum freely mounted on a shaft are investigated. The developed methodology was used in the studies, based on the energy method, the theory of bifurcations of motions, and the idea of a parametric solution to the problem. All steady-state modes of motion were found. It is established that these are modes of the pendulum jamming. Each mode is characterized by a corresponding jamming frequency. Depending on the velocity of rotation of the shaft, there may be one or three possible jamming frequencies. When there is only one jamming frequency, the corresponding mode of motion is globally asymptotically stable. When there are three jamming frequencies, locally asymptotically stable modes with the smallest and highest jamming frequencies of the pendulum. The smallest jamming frequency of the pendulum is close to resonance. This mode can be used to excite resonant vibrations in vibrating machines. The highest jamming frequency of a pendulum is close to the shaft rotation velocity. This mode can be used to excite non-resonant vibrations in vibrating machines.
Testing of the combined structural elements of support of a mine opening
Authors: Gasii Grygorii , Hasii Olena , Klimenko Vita
Published: May 2020

The stress-strain state of test specimens of the new combined system of support of a mine opening under imposed loads is studied. The test specimens are compound modular elements of the offered earlier combined system of support. Every single modular element is the regular quadrangular pyramid, consisting of a reinforced concrete slab and steel tube web members. The slab and web members are gathered in a complete element while concreting the slab. The tension sensor’s method of experimental research is applied to the test of specimens. The test of specimens is carried out under the load imposed with a hydraulic press. The load is set so that to imitate service conditions, including the most adverse. Design features of the offered support and test specimens are presented. Details of the support and its elements, sizes, production technology and assemblies are briefly described. The test methodology of specimens and the analysis of the results are presented. The load-carrying abilities of test specimens under the concentrated force and uniform load are obtained. Break down of slab and connection between the web members and the slab are the results of the test of the specimens under the concentrated force and the uniform load respectively.
Justification of the method of dust emissions localization on mobile crushing and sorting complexes of quarries with the use of air-and-water ejectors
Authors: Kolesnyk Valerii , Pavlychenko Artem , Borysovska Olena , Buchavyi Yurii , Kulikova Daria
Published: May 2020

Rock mass transloading from bunkers to conveyors or from conveyors to conveyors in quarries is accompanied by intense releases of dust into the atmosphere, which is a significant danger to the environment. The regularities of the interaction process between dust particles and droplets of a liquid (water) in polluted air flow are determined. It is established that when the pressure of compressed air is changed from 0.1 to 0.4 MPa (approximately in the range of 1 to 4 atm.), the average size of droplets decreases from 26 to 9 microns. Justification of the localization method of dust emissions into the atmosphere, arriving from the units of dust formation in crushing and sorting complexes of quarries, is done with the use of air-and-water ejectors − irrigators with highly efficient water use, sprayed with separate nozzles. Variants of air-and-water ejectors placement on dust formation sources are grounded. The choice of the optimal mode of air-and-water ejectors operation depends on the characteristic sizes of the formed dust particles, which are determined by the parameters of the crushing and sorting equipment in the quarry. Reducing dust emissions within the sanitary protection zone of the quarries prevents its dispersion in the adjacent zone.
Discrete mathematical model of travelling wave of conveyor transport
Authors: Kravets Viktor , Samusia Volodymyr , Kolosov Dmytro , Bas Kostiantyn , Onyshchenko Serhii
Published: May 2020

A mathematical model of a travelling wave in a matrix form is constructed. A degree of discreteness of the travelling wave and corresponding steps in phase and length are introduced. Asymmetric, unified matrices are compiled, which represent a generalized travelling wave, depending on a degree of discreteness. A generalized, dimensionless travelling wave is transformed into a required one with dimensions by specified technical parameters: amplitude and wavelength that is realized. A dependency of coordinates of points of a plane discrete travelling wave and discrete phase angles is established. A dependency of angular (phase) velocity and velocity of the travelling wave, which corresponds to the known results, is established. The presented matrix mathematical model is considered as an initial stage of technical possibility to realize a continuous travelling wave in a discrete form when developing a new type of transportation – wave transport.
The grounds for the modification of membranes with the help of quantum mechanical calculation method
Authors: Nechytailo Mykola , Nahorna Olena , Nesterova Olena
Published: May 2020

In the process of water purification to increase the reflective capacity of ultrafiltration membranes, their surface modification is applied with aluminium oxychloride and polyhexamethylene guanidine hydrochloride are used. This enables to extract organic contaminations at 90% level, not less their salt balance. To estimate the reaction capacity, the method of calculation of energetic parameters and structural characteristics with the help of chemical analysis quanta is applied. For the analysis, the semiempirical method of modified neglect of diatomic overlapping is used. The prospective estimation of gel layer formation on the membrane surface is made. The method of molecular mechanics is applied in quantumchemical calculations for each substance and the material of the membrane. While analyzing the interaction between the material of the membrane and membrane-forming supplement, the charges on molecules` atoms, the determination of energetic levels of the lower vacant and upper filled molecular orbitals and energetic gap are estimated. It was proved that aluminium oxychloride precipitates on the membrane surface due to Van der Waltz forces, and the inoculation of polyhexamethylene guanidine occurs at fiber functionalization through the formation of hydrogen type of bond between the groups С≡N polymer and =N-H group. Scientific substantiation of membrane modification was obtained.
Investigation of the influence of flooded bench hydraulic mining parameters on sludge pond formation in the pit residual space
Authors: Sobko Borys , Lozhnikov Oleksii , Drebenshtedt Carsten
Published: May 2020

The research aim is establishment of effective parameters for mining of flooded bench by a hydro-mechanized complex with dumping of enclosing rocks in a sludge pond of pit residual space. The established research results make it possible to choose the effective width of the dredger mining cut at the hydromechanical method, taking into account the volume of the excavation and dump pipeline movements. Two technological schemes for the formation of a sludge pond in the pit residual space are proposed, they differ in the direction of the sludge pond movement relatively to the pit front. The established dependence of the number of movements of the sludge pond pipeline on the width of the dump pass allows to choose its effective value, taking into account the number of discharge pipes. Based on the dependence of the average monthly excavation volume and the number of movements of sludge pond pipeline on the width of cut face, the optimal number of discharge pipes is established. The research results allow establishing the effective dredger width of the sludge pond and the number of discharge pipes provided that a transverse or longitudinal pass at the internal sludge pond formation is applied during the mining.
Present problems of vibration isolation in heavy mining machines at long-term cyclic loads
Authors: Dyrda Vitalii , Kobets Anatolii , Bulat Ievgeniia , Slobodian Serhii , Lysytsia Mykola , Sokol Serhii , Lapin Vladimir , Ahaltsov Hennadii
Published: May 2020

On the basis of the developed simulation model and the Boltzmann-Volterra integral relations with kernels of relaxation and aftereffect, an equation was worked out, which made it possible to take into account the rubber viscoelastic properties in full volume; in this equation, stiffness operator of elastic suspension in the machine is written by using fractional exponential function of the Yu. Rabotnov’s type; on the basis of the mathematical model, the basic parameters of the machine under the study were calculated; in particular, for the vortex mixer, the time dependences of amplitude of the mixer housing vibrations and coefficient of vibration isolation efficiency were calculated with taking into account aging of elastic link material in the machines; the calculation results were compared with the results of industrial tests of the vortex mixer operation lasting for 16 years. The theory and method for calculating vibration isolation systems with rubber elastic links for heavy mining machines were developed with taking into account material structure changes due to the effects of aging.
X-ray diffraction method application to assess the energy losses on explosive-rock contact under various blasting
Authors: Kratkovskyi Ihor , Yefremov Ernest , Ishchenko Kostyantyn , Khomeriki Sergo
Published: May 2020

The dissipative energy losses of the explosion on the explosive-rock contact are usually evaluated with comparative analysis of the particle size distribution of finely dispersed fractions (0-100 microns). The more tiny particles contained in the destruction products, the higher there is a level of energy loss during the explosion. Fine dust granulometric characteristics are determined by processing the mass measurements data of the individual smallest particles sizes when decoding microphotographs obtained by a microscope. However due to the chromatic aberrations due the wave nature of light and the optical systems imperfection, it is not possible to reliably estimate the mass and granulometric characteristics particles of micron size. X-ray diffraction method for studying ultrafine rock fracture products makes it possible to estimate the dissipative energy losses on explosive-rock contact based on the reflected X-ray beam total intensity in diffractograms. In order to establish the effectiveness of methods for reducing the level of dissipative energy losses of an explosion, X-ray diffraction patterns of finely dispersed fracture products of rock samples under various conditions of dynamic loading are analyzed (using different charge designs, attenuating the rocks by the action of a surfactant, and the force action of a different gradient stress field).
The resource-saving technology to restore the accumulation ability of tailing ponds
Authors: Medvedieva Olha , Lapshyn Yevhen , Koval Natalia , Zeynullin Abdikarim , Gupalo Olena
Published: May 2020

The accumulating capacity of tailing ponds by technology infusion of pulp preliminary clarification in the alluvium charts with its subsequent thickening and storage in the form of a highly concentrated pulp at the bottom of the pond is proposed by authors in the work. For the first time, the time dependence of filling a temporary pond on the ratio of the initial and condensed slurry concentrations for such technologies is obtained. The formula for calculating the degree of condensation is proposed. It provides the parameters selection and justification of equipment for removing water from a temporary pond as the map is filled with the accumulating capacity restoration of tailing ponds. The calculation results for the proposed dependencies allow us to establish: the necessary values of the thickening degree of the hydromixture, the possible intervals of the change in the pulp flow before and after thickening, as well as the volume of water taken from the temporary pond, depending on the concentration of the slurry entering the pond from the alluvium maps, its volumetric flow rate , geometric parameters of the technology for waste storage and the operation duration of a temporary pond.
Belt conveyor failure simulation at the design stage with transverse displacements of the belt
Authors: Monastyrskyi Vitalii , Monastyrskyi Serhii , Nomerovskyi Denis , Mostovyi Borys
Published: May 2020

To find possible conveyor failures at the design stage means to determine a transverse belt displacement and compare the obtained data with the permissible ones. The dynamic problem of the belt movement on the conveyor has been defined. Resistance and external forces, limits of the belt displacement have been determined. The transverse belt displacement can be described by partial differential equations. To solve the problem, the Fourier transform has been used. Change patterns in the transverse belt conveyor displacement dependent on conveyor’s parameters, type of load, and skewing of the idlers along the conveyor have been obtained. The results agree with experimental data. The method of adaptive control of the transverse belt displacement has been described. The essence of this method is to adapt the model of the moving belt in the conveying trough to changed conditions and to reveal the uncertainty of the control with the known parameters of the mathematical model.
Calculation of the maximum velocity of gravity flow in the pond-clarifier with higher aquatic plants
Authors: Semenenko Yevhen , Demchenko Tetіana , Pavlichenko Artyom
Published: May 2020

The analysis of the possible maximum fluid flow rates when using higher aquatic plants for clarification of recycled water in the pondclarifier of the tailing pond has carried out. The study has been performed on the basis of a mathematical model of a plane slow stationary gravity flow of a viscous fluid in two parallel layers. The results of the study made it possible to determine the fluid velocity through a layer of higher aquatic plants floating on a free surface. The maximum possible velocity depending on the layer porosity has been determined. This value is necessary to determine the rational parameters of the process of clarifying technical recycled water from particles of the given hydraulic size, taking into account the pond-clarifier geometric dimensions. It is shown that the velocity in the layer with higher aquatic plants has been determined by the ratio of two parameters of this layer - porosity and dimensionless resistance coefficient. It has been shown that the maximum velocity value coefficient in the layer with plants floating on free surface depends only on porosity of this layer and does not depend on its resistance coefficient.
Development of a mathematical model of a vibrating polyfrequency screen as a dynamic system with distributed parameters
Authors: Shevchenko Heorhii , Shevchenko Volodymyr , Holobokyi Serhii
Published: May 2020

A mathematical model of a vibrating polyfrequency screen as a dynamic system with distributed parameters has been developed. The dynamic system of solids of finite sizes was chosen as the design scheme for the screen: framework, sieves with bulk material and impactors, the contact interaction of which occurs through two-side bonds and collisions on surface areas that have elastic-damping coverings. It is shown that a change in the amplitude of the exciting force has a significant effect on the dynamics of vibration impactors of a polyfrequency vibrating. There is an amplitude value at which the impactor passes from the mode without interacting with elastic bonds to the vibro-impact mode. The impactor movements begin to change disproportionately altered by the exciting force amplitude. It is shown that the start of the impactors in the screen substantially depends on the exciting force. Changes in the amplitude of the exciting force make it possible to achieve chaotic oscillations of impactors, which in turn leads to oscillations of screen surfaces with a continuous frequency spectrum, i.e. to the operation mode of the screen, which is most appropriate for dehydration and separation of fine mineral fractions.
Numerical model to simulate ventilation of dead-end mine working with brattice
Authors: Voloshyn Oleksii , Biliaiev Mykola , Biliaieva Viktoriia , Kozachyna Vitalii , Berlov Oleksandr , Rusakova Tetyana , Kalashnikov Ivan
Published: May 2020

A computational model to simulate ventilation of a dead-end mine working with line brattice has been developed. To solve fluid dynamics problem, i.e. to compute flow pattern, model of inviscid flow has been used. That allows to compute quickly air flow pattern. To simulate dust dispersion in the dead-end mine working with brattice twodimensional equation of mass transfer has been used. Numerical integration of Laplas equation for the velocity potential has been carried out using Samarski two steps difference scheme of splitting. Proposed CFD model allows quick computing of dust dispersion in the dead-end mine working with brattice. Markers (porosity technique) have been used to create the complex geometrical form of computational domain. Results of numerical experiments which had been performed on the basis of the developed CFD model have been presented.
Determination of some mining parameters of the long wall for the effective use of plough systems in the Western Donbas mines
Authors: Voloshyn Oleksii , Onika Siarhei , Riabtsev Oleh , Protsak Serhii , Nykyforuk Olena
Published: May 2020

Theoretical studies of stress strain state of rock under the extraction pillar working by mechanized complex with plough systems were conducted. As a result of studies the mining parameters of the wall face working are presented. The mining parameters include the width of coal shavings continuously removed before reaching the critical rock pressure in the face and duration of the technological pause between removal of coal shavings, that leads to “relaxation” of rock pressure in the bearing zone to a safe state for continued mining. The use of the values of these parameters during the extraction pillar working ensures efficient and no-failure operation of high-performance mechanized complexes equipped with plough systems as shown by the example of mining and geological conditions of one of the mines of the Western Donbas.
A parameter-robust iterative method for Stokes–Darcy problems retaining local mass conservation
Authors: Boon Wietse M.
Published: May 2020

We consider a coupled model of free-flow and porous medium flow, governed by stationary Stokes and Darcy flow, respectively. The coupling between the two systems is enforced by introducing a single variable representing the normal flux across the interface. The problem is reduced to a system concerning only the interface flux variable, which is shown to be well-posed in appropriately weighted norms. An iterative solution scheme is then proposed to solve the reduced problem such that mass is conserved at each iteration. By introducing a preconditioner based on the weighted norms from the analysis, the performance of the iterative scheme is shown to be robust with respect to material and discretization parameters. By construction, the scheme is applicable to a wide range of locally conservative discretization schemes and we consider explicit examples in the framework of Mixed Finite Element methods. Finally, the theoretical results are confirmed with the use of numerical experiments.
Young's modulus estimation in food samples: effect of experimental parameters
Authors: Sinha Ankita , Bhargav Atul
Published: May 2020

Texture is an important attribute in the quality assessment of processed food products. Recently, Young's modulus is identified as one of the most important indicators of food texture. However, there is much ambiguity in the literature about quantification and standards for texture analysis. In this paper, the sensitivity of Young's modulus (and thus texture) towards the applied deformation rate, sample shape and size, moisture content is studied experimentally for potato and sweet potato samples. We found that Young's moduli vary by as much as 54% depending on the rate of applied strain, indicating the need for test standards. The strain rate dependent behaviour exhibits the viscoelastic nature of the potato samples, which was further validated by stress relaxation and cyclic tests. Based on our experimental iterations and associated finding of the work, we propose the need for a standardised procedure for measuring Young's modulus and texture analysis. We expect this work to serve as a crucial step toward standardised texture measurement during thermal processing of food products.
Rotational speed control of magnetic coupling with variable damping method
Authors: Jian Zhang , Kun Liu
Published: May 2020

Permanent Magnetic Coupling (PMC) is used in underwater vehicle to transmit torque from the motor to propeller without leakage and friction. Output rotational speed stability of PMC is an important index indicating the PMC output makes smaller vibration. To improve the stability of the output rotational speed, PMC dynamic characteristic was analyzed based on Lagrange equation in this paper. The dynamic characteristic was indicated by the angular phase generated by the master rotor and the slave rotor. The angular phase varied with the damping coefficient, torsional rigidity and rotational inertia of PMC. These parameters' influence on the angular phase was analyzed and the results revealed the rules between these parameters and the angular phase. Based on the rules, a variable damping method was proposed to control the angular phase. The angular phase changed smoothly with this method that was used to design a variable damping controller based on electromagnetic damping effect principle. This method was verified by theoretical calculation and finite element analysis (FEA). Finally, a novel variable damping PMC was designed to improve the output rotational speed stability of PMC.