bluuebunny/crossref_metadata_2025 huggingface dataset:
Unveiling the role of intra and interatomic interactions in the energetics of reaction schemes: a quantum chemical topology analysis
Authors: Jara-Cortés Jesús , Landeros-Rivera Bruno , Hernández-Trujillo Jesús
Published: October 2018

The interacting quantum atoms method provides an interpretative tool for chemical reaction energies in terms of physically meaningful atomic contributions.
Electronic spectrum and characterization of diabatic potential energy surfaces for thiophenol
Authors: Zhang Linyao , Truhlar Donald G. , Sun Shaozeng
Published: October 2018

We present an accurate simulation of the UV spectrum and a diabatization of three singlet potential surfaces along four coordinates.
Effect of Cu intercalation on humidity sensing properties of Bi2Se3 topological insulator single crystals
Authors: Mazumder Kushal , Sharma Alfa , Kumar Yogendra , Shirage Parasharam M.
Published: October 2018

Adsorption isotherm models confirm the effect of Cu intercalation on humidity sensing properties of topological insulator Bi2Se3 single crystals.
Catalysis by hybrid sp2/sp3nanodiamonds and their role in the design of advanced nanocarbon materials
Authors: Lin Yangming , Sun Xiaoyan , Su Dang Sheng , Centi Gabriele , Perathoner Siglinda
Published: October 2018

Hybrid sp2/sp3nanocarbons, in particular sp3-hybridized ultra-dispersed nanodiamonds and derivative materials, such as the sp3/sp2-hybridized bucky nanodiamonds and sp2-hybridized onion-like carbons, represent a rather interesting class of catalysts still under consideration.
C3N4–Mn/CNT composite as a heterogeneous catalyst in the electro-peroxone process for promoting the reaction between O3and H2O2in acid solution
Authors: Guo Zhuang , Zhou Linbi , Cao Hongbin , Xie Yongbing , Xiao Jiadong , Yang Jin , Zhang Yi
Published: October 2018

The C3N4–Mn/CNT catalyst promotes the reaction between O3and H2O2in acid solution, and enhances the degradation efficiency of the electro-peroxone process.
Interplay between H-bonding and interpenetration in an aqueous copper(ii)–aminoalcohol–pyromellitic acid system: self-assembly synthesis, structural features and catalysis
Authors: Fernandes Tiago A. , Kirillova Marina V. , André Vânia , Kirillov Alexander M.
Published: October 2018

Two new copper(ii) coordination compounds were self-assembled fromN-methyldiethanolamine and pyromellitic acid as principal building blocks; their structural and catalytic features were investigated.
Ru-Loaded mesoporous WO3 microflowers for dual applications: enhanced H2S sensing and sunlight-driven photocatalysis
Authors: Mehta Swati S. , Nadargi Digambar Y. , Tamboli Mohaseen S. , Chaudhary Latika S. , Patil Pramod S. , Mulla Imtiaz S. , Suryavanshi Sharad S.
Published: October 2018

We report a facile synthesis of Ru-loaded WO3 marigold structures through a hydrothermal route and their bidirectional applications as enhanced H2S gas sensors and efficient sunlight-driven photocatalysts.
Hydroboration of carbon dioxide with catechol- and pinacolborane using an Ir–CNP* pincer complex. Water influence on the catalytic activity
Authors: Sánchez Práxedes , Hernández-Juárez Martín , Rendón Nuria , López-Serrano Joaquín , Álvarez Eleuterio , Paneque Margarita , Suárez Andrés
Published: October 2018

Lutidine-derived CNP*–Ir complexes catalyze the hydroboration of CO2 to methoxyborane and formoxyborane in the presence of small amounts of water.
Interference of non-lethal levels of graphene oxide in biofilm formation and adaptive response of quorum sensing in bacteria
Authors: Zhang Yunyun , Li Na , Wang Meizhen , Feng Huajun , Xu Chao , Xu Feng
Published: October 2018

Non-lethal levels of graphene oxide interfere with biofilm formation, and this inhibition could be counteracted after long-term exposure.
Antimony speciation analysis by hydride trapping on hybrid nanoparticles packed in a needle trap device with electro-thermal atomic absorption spectrometry determination
Authors: Maratta Ariel , Carrizo Brian , Bazán Vanesa L. , Villafañe Gastón , Dante Martínez Luis , Pacheco Pablo
Published: October 2018

Novel hybrid nanoparticles show faster antimony adsorption kinetics compared to single nanoparticles, becoming superior sorbents for analytical applications.
Fingerprints of native defects in monolayer PbTe
Authors: Ekuma C. E.
Published: October 2018

Understanding the intricate interplay of defects and electron–electron interactions is crucial to exploiting the full potential of materials for practical applications.
Self-assembled Mn3O4 nano-clusters over carbon nanotube threads with enhanced supercapacitor performance
Authors: Hiremath Vishwanath , Cho Min , Seo Jeong Gil
Published: October 2018

Self-assembled Mn3O4@CNT nano-clusters with improved capacitance and cyclic stability designed for supercapacitor application.
Cross-linked Ni(OH)2/CuCo2S4/Ni networks as binder-free electrodes for high performance supercapatteries
Authors: Tang Ning , You Huihui , Li Ming , Chen George Zheng , Zhang Lei
Published: October 2018

The cross-linked networks can achieve much improved electrochemical performance and cycling stability, demonstrating the feasibility and effectiveness of structure engineering.
A morphological, enzymatic and metabolic approach to elucidate apoptotic-like cell death in fungi exposed to h- and α-molybdenum trioxide nanoparticles
Authors: Chaves-Lopez Clemencia , Nguyen Hang N. , Oliveira Rodrigo C. , Nadres Enrico T. , Paparella Antonello , Rodrigues Debora F.
Published: October 2018

The present study compares for the first time the effects of h-MoO3and α-MoO3against two fungal strains:Aspergillus nigerandAspergillus flavus.
Synthesis of organic–inorganic hybrids via a high-pressure-ramp process: the effect of inorganic nanoparticle loading on structural and photochromic properties
Authors: Evlyukhin E. , Museur L. , Diaz-Gomez-Trevino A. P. , Traore M. , Brinza O. , Zerr A. , Kanaev A.
Published: October 2018

Organic polymerization remains a limiting step in the preparation of organic–inorganic hybrid materials with a strong concentration of the inorganic component.
Mapping the transition to superwetting state for nanotextured surfaces templated from block-copolymer self-assembly
Authors: Telecka Agnieszka , Mandsberg Nikolaj Kofoed , Li Tao , Ludvigsen Emil , Ndoni Sokol , Di Mundo Rosa , Palumbo Fabio , Fiutowski Jacek , Chiriaev Serguei , Taboryski Rafael
Published: October 2018

The transition to superwetting of hydrophilic nano-textured surfaces is mapped in terms of surface chemistry and texture geometry.
Acetone: a solvent or a reagent depending on the addition order in SET-LRP
Authors: Moreno Adrian , Lejnieks Jānis , Galià Marina , Lligadas Gerard , Percec Virgil
Published: October 2018

The importance of reagent order in biphasic SET-LRP in acetone/water mixtures is shown.
Combining JBCA and Marfey's methodology to determine the absolute configuration of threonines: the case of gunungamide A, a new cyclic depsipeptide containing chloropyrrole from the sponge Discodermia sp.
Authors: Tarazona Guillermo , Fernández Rogelio , Cruz Patricia G. , Pérez Marta , Rodríguez Jaime , Jiménez Carlos , Cuevas Carmen
Published: October 2018

JBCA and Marfey's allowed us to distinguish threonines diasteroisomers.
Effects of end-on oriented polymer chains at the donor/acceptor interface in organic solar cells
Authors: Wang Fanji , Nakano Kyohei , Yoshida Hiroyuki , Hashimoto Kazuhito , Segawa Hiroshi , Hsu Chain-Shu , Tajima Keisuke
Published: October 2018

Intrachain hole delocalization vertical to donor and acceptor interface weakens coulombic interaction of the charge pairs and facilitate the charge separation in organic solar cells.
LIMK2-1, a new isoform of human LIMK2, regulates actin cytoskeleton remodeling via a different signaling pathway than that of its two homologs, LIMK2a and LIMK2b
Authors: Vallée Béatrice , Cuberos Hélène , Doudeau Michel , Godin Fabienne , Gosset David , Vourc'h Patrick , Andres Christian R. , Bénédetti Hélène
Published: October 2018

LIMK1 and LIMK2 (LIMKs, LIM kinases) are kinases that play a crucial role in cytoskeleton dynamics by independently regulating both actin filament and microtubule remodeling. LIMK1 and, more recently, LIMK2 have been shown to be involved in cancer development and metastasis, resistance of cancer cells to microtubule-targeted treatments, neurological diseases, and viral infection. LIMKs have thus recently emerged as new therapeutic targets. Databanks describe three isoforms of human LIMK2: LIMK2a, LIMK2b, and LIMK2-1. Evidence suggests that they may not have completely overlapping functions. We biochemically characterized the three isoforms to better delineate their potential roles, focusing on LIMK2-1, which has only been described at the mRNA level in a single study. LIMK2-1 has a protein phosphatase 1 (PP1) inhibitory domain at its C-terminus which its two counterparts do not. We showed that the LIMK2-1 protein is indeed synthesized. LIMK2-1 does not phosphorylate cofilin, the canonical substrate of LIMKs, although it has kinase activity and promotes actin stress fiber formation. Instead, it interacts with PP1 and partially inhibits its activity towards cofilin. Our data suggest that LIMK2-1 regulates actin cytoskeleton dynamics by preventing PP1-mediated cofilin dephosphorylation, rather than by directly phosphorylating cofilin as its two counterparts, LIMK2a and LIMK2b. This specificity may allow for tight regulation of the phospho-cofilin pool, determining the fate of the cell.
Characterization of TCDD-inducible poly-ADP-ribose polymerase (TIPARP/ARTD14) catalytic activity
Authors: Gomez Alvin , Bindesbøll Christian , Satheesh Somisetty V. , Grimaldi Giulia , Hutin David , MacPherson Laura , Ahmed Shaimaa , Tamblyn Laura , Cho Tiffany , Nebb Hilde Irene , Moen Anders , Anonsen Jan Haug , Grant Denis M. , Matthews Jason
Published: October 2018

Here, we report the biochemical characterization of the mono-ADP-ribosyltransferase 2,3,7,8-tetrachlorodibenzo-p-dioxin poly-ADP-ribose polymerase (TIPARP/ARTD14/PARP7), which is known to repress aryl hydrocarbon receptor (AHR)-dependent transcription. We found that the nuclear localization of TIPARP was dependent on a short N-terminal sequence and its zinc finger domain. Deletion and in vitro ADP-ribosylation studies identified amino acids 400–657 as the minimum catalytically active region, which retained its ability to mono-ADP-ribosylate AHR. However, the ability of TIPARP to ADP-ribosylate and repress AHR in cells was dependent on both its catalytic activity and zinc finger domain. The catalytic activity of TIPARP was resistant to meta-iodobenzylguanidine but sensitive to iodoacetamide and hydroxylamine, implicating cysteines and acidic side chains as ADP-ribosylated target residues. Mass spectrometry identified multiple ADP-ribosylated peptides in TIPARP and AHR. Electron transfer dissociation analysis of the TIPARP peptide 33ITPLKTCFK41 revealed cysteine 39 as a site for mono-ADP-ribosylation. Mutation of cysteine 39 to alanine resulted in a small, but significant, reduction in TIPARP autoribosylation activity, suggesting that additional amino acid residues are modified, but loss of cysteine 39 did not prevent its ability to repress AHR. Our findings characterize the subcellular localization and mono-ADP-ribosyltransferase activity of TIPARP, identify cysteine as a mono-ADP-ribosylated residue targeted by this enzyme, and confirm the TIPARP-dependent mono-ADP-ribosylation of other protein targets, such as AHR.
Courtiers en développement et contrôleurs d’accès : deux figures incontournables des politiques de lutte contre la pauvreté rurale en Afrique du Sud
Authors: Bourblanc Magalie , Ducrot Raphaëlle
Published: October 2018

Cet article analyse la mise en œuvre de programmes publics de lutte contre la pauvreté rurale en Afrique du Sud et fait le parallèle avec les politiques d’aide internationale au développement, en soulignant en particulier un de leurs travers, à savoir leur relative inefficacité. En remobilisant un concept-clé des travaux en anthropologie, celui du courtier, couplé à la redécouverte de l’idée de ≪ point de passage obligé » (gatekeeping) issue de la science politique, cet article montre à quel point les courtiers ont l’ambition de s’imposer comme des intermédiaires hégémoniques au sein d’un univers du courtage très disputé. À cette occasion, notre article s’interroge sur les relations entre les figures nouvelles et traditionnelles du courtage, c’est-à-dire entre les conseils d’administration des comités d’irrigation et les élites tribales.
L’appropriation de l’arbre, un nouveau front pour la cacaoculture ivoirienne ? Contraintes techniques, environnementales et foncières
Authors: Sanial Elsa
Published: October 2018

Les producteurs de cacao ivoiriens font face à une nouvelle donne environnementale : en plus de la disparition du couvert forestier sous la progression des fronts pionniers cacaoyers, les systèmes conduits en monoculture montrent leurs limites et les évolutions climatiques récentes sont moins propices à cette culture. La conjonction de ces différents éléments conduit à une situation de blocage structurel. À la croisée de données environnementales et socio-politiques, cet article décrit et interroge les stratégies d’adaptation des producteurs de cacao dans ce contexte ≪ post-forestier ». L’analyse des pratiques indique une dynamique d’introduction d’arbres associés dans les plantations face aux conditions environnementales. Néanmoins, cette stratégie d’adaptation agroforestière et notamment l’introduction de bois d’oeuvre de valeur sont freinées par des obstacles techniques (faible maîtrise de la plantation d’arbres de forêt), environnementaux (composition du recrû spontané) et fonciers (impensé juridique du statut de l’arbre hors forêt).
Load carrying capacity of the eccentric joint in the truss made of open cross-sections
Authors: Gordziej-Zagórowska Małgorzata , Urbańska-Galewska Elżbieta
Published: October 2018

The influence of eccentricity at intersections of truss members on the load carrying capacity of the truss joint is presented in the paper. The research truss elements were designed as cold-formed open cross section. Analytical calculations, numerical analysis and experimental research were conducted to reveal how the eccentricity affects the effort of material in the joint area. The results of analysis and investigations are compared and discussed. The main achievement of the tests carried out is statement that slender plane members of the compression chords are safe compared with the results of analytical calculations.
Investigation of laser heat treated Monel 400
Authors: Kukliński Mateusz , Bartkowska Aneta , Przestacki Damian
Published: October 2018

In this research, Monel metal was laser heat-treated for microstructural, microhardness and roughness investigation. The treatment is an initial stage for welding Monel without additional material for structural elements. The treatment was carried out with diode laser TruDiode 3006 which allows to reach a power of 3 kW. The material was treated with a constant laser beam power, equal to 1400 W, and four different laser beam velocities: 5, 25, 50 and 75 m/min. The distance between single laser tracks was 0,5 mm in every experimental series. It was found that laser heat treatment of Monel does not influence its hardness. The depth of melted areas is decreasing with an increasing laser beam velocity. The melted area manufactured with laser beam velocity equal to 5 m/min is about 350 μm. Increasing the laser beam velocity to 75 m/min causes depth reduction to about 100 μm. The melted areas are built with column crystals oriented in the direction of heat dissipation perpendicular to the heating direction.
Impact of single-layer dome modelling on the critical load capacity
Authors: Zabojszcza Paweł , Radoń Urszula , Obara Paulina
Published: October 2018

In the study an attempt was made to evaluate the effect produced by the modelling of the single-layer lattice dome on its critical load capacity. The modelling concerned the means of connecting bars in a node, bars of the lattice dome, and the effect of geometric imperfections. Taking steel covers, two basic means of modelling of how bars are connected in the node can be distinguished, namely pin and rigid joints. In the study, the pin joint was SBP-1 type connector, whereas the rigid joint - WABI-1 connector. In the description of bars, truss and frame elements were employed. Each element accounted for geometric nonlinearities in the Lagrange description. Regarding a frame element, the physical relationships represented the elastic behaviour of the structure with the use of the Hooke’s law. With respect to the compression truss elements, a nonlinear relationship resulting from experimental investigations was additionally employed. Stability analysis of the structure was performed by means of the Finite Element Method using Abaqus and Robot Structural Analysis software. In order to obtain the load-displacement relations, the Riks arc length method was used. The analysis was focused on global modes of stability loss due to snap-through and bifurcation.
Acoustic non-destructive testing of high temperature degraded concrete with comparison of acoustic impedance
Authors: Dvořák Richard , Chobola Zdeněk , Kusák Ivo
Published: October 2018

The paper is focused on non-destructive measurement of high temperature degraded concrete test specimens of three mixtures different by the use of coarse aggregate. Testing is done by ultrasonicpulse velocitymethod and Impact-Echo method. Non-destructive results are compared with destructive tests. Ultrasonic pulse velocity, dominant resonance frequency and acoustic impedance are discussed and compared with changes in density, cubic compressive strength, and tensile strength of concrete. The paper suggests possible assessment of degraded concrete by the change in acoustic impedance dependent on residual tensile strength.
The effect of macro polymer fibres length and content on the fibre reinforced concrete
Authors: Mariak Aleksandra , Kurpińska Marzena
Published: October 2018

The paper presents studies of a ready-mix concrete containing polymer fibres of three different lengths: 24, 38 and 54 mm. The performed tests allowed to determine the effect of fibre volume fraction and length on the concrete strength. The basic parameters of concrete mixture (consistency, air content and bulk density) were identified. Fibre reinforced concrete belongs to a group of composite materials. The polymer fibres are applied in the concrete in structures where the reduction of shrinkage cracking as well as corrosion resistance and fire temperatures are required. It is widely known, that the cracking behaviour of concrete structures depends on flexural tensile strength of concrete. The addition of fibres significantly improves the tensile strength. The experimental study, including axial compressive strength and center-point loading flexural tensile strength, was carried out. The scope of the research was also expanded by the usage of a scanning microscope. The test results showed the effect of fibre length and fibre combinations on mechanical properties of concrete. The effect of the research is to formulate guidelines due to the quantity of macro polymer fibres. In general, appropriate fibre content brings a beneficial effect e.g. improves better workability of a concrete mixture.
Maturity testing of 3D printing concrete with inert microfiller
Authors: Skibicki Szymon , Kaszyńska Maria , Techman Mateusz
Published: October 2018

The 3D Printing of cement composites is one of the fastest developing technologies of modern concrete. The 3D printing involves concretes with high amounts of microfillers. The study analyses the influence of curing conditions on the development of strength of concretes applicable in 3D printing. Ten mixes were tested in the study. In the studied cases cement constituted to 50% of the mass, while microfillers such as lime stone powder, kaolin, quartz powder and sand (up to 2 mm) constituted to the rest of the mass. Samples were cured for 7 days in exothermic conditions at 5°C, 20°C, 35°C. Standard mortar samples of 4x4x16 cm and cylinders with 46.5 mm and height of 35 mm that simulate the printed 3D path were made. The compressive strength was tested after 12h, 24h, 48h, 72h, 168 h and 28 days. Based on the acquired results the temperature development function was formulated and activation energy was determined. The results showed that the proposed method is useful in evaluation of printed concrete curing. It can be also used to determine the time of loading the wall which can speed up the process of constructing while maintaining degree of safety.
The SHM system as a data source for durability assessment. Case study of Rędziński Bridge stay cable system
Authors: Teichgraeber Marco , Hawryszków Paweł
Published: October 2018

The paper is an introduction to a durability assessment algorithm based on the data collected by a Structural Health Monitoring (SHM) system of a cable-stayed concrete bridge. It contains basic information about the structure of the Rędziński Bridge and its monitoring system. The collected data from the first years are described and analysed. Later the algorithm to assess the durability of stay cables based on probabilistic method is presented.
Verification of selected calculation methods regarding shear strength in beams without web reinforcement
Authors: Hirsz Marta , Nagrodzka-Godycka Krystyna
Published: October 2018

The purpose of the article was to compare selected calculation methods regarding shear strength in reinforced concrete beams without web reinforcement. Several calculation methods were tested. This included codes: PN-EN 1992-1-1:2008, ACI 318-14 andfibModel Code for Concrete Structures 2010. The analysis also consists of authorial methods published in technical literature. Calculations of shear strengths were made based on experimental works found in literature. The shear strength ratios Vtest/Vcalcwere chosen to be the yardstick of comparison, where Vtestis the experimental shear strength and Vcalcis the calculated shear strength. A wide range of variables including shear span/depth ratio, compressive strength of concrete, longitudinal steel percentage helped to verify the applicability of calculation methods. Although most of authorial techniques proved to be unstable, they succeeded to show that codes’ formulas for shear strength may still be improved. The presented article is a part of Authors’ long term research in the matter and a new chapter of their study now concerning beams without web reinforcement.
The collusion detection in public procurements – selected methods applied for the road construction industry in Poland
Authors: Foremny Andrzej , Anysz Hubert
Published: October 2018

Based on successful international examples of collusion detection, four indicators of the collusion have been chosen and analysed in this paper. The research was done for the majority of tender procedures in the road construction industry, in Poland that was finished in 2016 with the selection of a general contractor. Based on [1, 2, 3] the following four indicators were chosen: the number of offers placed in the tender procedure, the range of bid prices being offered, exactly the same set of offerors in a few tender procedures, repeating ordering the works execution to the same contractor in a given geographical region.
The criteria for evaluation and selection the best tender applied by the authorities in Poland and selected EU countries
Authors: Grzyl Beata , Apollo Magdalena , Miszewska-Urbańska Emilia , Kristowski Adam
Published: October 2018

The aim of the regulation in EU countries concerning public procurement is to ensure efficient spending of funds by evaluating and choosing the most advantageous offer. The aim of the conducted research is to determine the extent the Polish contracting entities benefit from the possibility of broad selection of various criteria for tender evaluation. On the basis of the analysis of 500 notices on work procedures conducted in the third quarter of 2016 - the third quarter of 2017 in open and restricted tenders in Poland and 500 tenders in open and restricted proceedings in five selected EU countries, the authors compared and classified of applied the practical criteria to evaluate and select the best offer. In order to collect the information presented in the article, the authors applied the documentary method using domestic and foreign literature regarding the subject and official publications.
Application possibilities of LBN for civil engineering issues
Authors: Siemaszko Agata , Apollo Magdalena
Published: October 2018

Bayesian Networks (BN) are efficient to represent knowledge and for the reasoning in uncertainty. However the classic BN requires manual definition of the network structure by an expert, who also defines the values entered into the conditional probability tables. In practice, it can be time-consuming, hence the article proposes the use of Learning Bayesian Networks (LBN). The aim of the study is not only to present LBN, which can be helpful in civil engineering problems, but also to analyze and evaluate the potential of a selected software. Based on a real example the functional values of the Open Markov, Hugin and AgenaRisk applications were compared.
Critical evaluation of modern concrete applications
Authors: Malara Jarosław , Szafraniec Justyna
Published: October 2018

In the article, the modern and innovative applications of concrete mix have been critically analyzed. The authors focused first of all on transparent concrete - LiTraCon. The article mainly analyzed its technical parameters. Another modern way of using the concrete mix, which has been included in the publication, is paving stone absorbed in daylight. This material description is primarily, focused on its serviceability. Another material presented is white concrete, its advantage is the ease of colour choice. The authors also described the possibilities of using properly shaped architectural concrete as well as its unusual use in the form of doors. The entire publication concludes with a summary.
Determination of p-y curves for offshore piles based on in-situ soil investigations
Authors: Międlarz Kamila , Bałachowski Lech
Published: October 2018

Offshore piles are subjected to complex loads with considerable lateral component. The pile-soil response to lateral loads can be described with the p-y method. For a given depth the load–deflection relationship is built to simulate the surrounding soil stiffness. This state-of-art paper presents a brief discussion of determination methods for the p-y curves using a standard approach based on the soil parameters derived from laboratory and in-situ tests or directly from field tests. The basic relationships for both cohesive and cohesionless soils are discussed. The advantage of direct design methods to describe the p-y curve relies in the reduction of necessary laboratory tests.
An algorithm to generate high dense packing of particles with various shapes
Authors: Miśkiewicz Konrad , Banasiak Robert , Niedostatkiewicz Maciej , Grudzień Krzysztof , Babout Laurent
Published: October 2018

Discrete Element Method (DEM) is one of available numerical methods to compute movement of particles in large scale simulations. The method has been frequently applied to simulate the cases of grain or bulk material as the major research issue. The paper describes a new method of generating high dense packing with mixed material of two different shape used in DEM simulation. The initial packing is an important parameter to control, because have influence on the first few seconds after start the simulation. Some-times when the material in silo is arranged with loose packing before the start, the particles move downward gravity. These changes between the start and the first few seconds in simulations act strongly on the results at the end of a discharging process in silo. At the initial simulation time it is important to prepare proper packing with mixed material, in order to make sure that the particles will not move due to gravity action. This solution is a necessary step to integrate in the simulation procedure in order to compare later the computer simulation with experimental measurements of material discharge in a silo.
Investigation of Hydro-piercing Method for Stainless Steels by Finite Element Method
Authors: Gökay Korkmaz Habip , Toros Serkan , Halkaci Mehmet , Halkaci Hüseyin Selçuk
Published: October 2018

Researches and studies on hydroforming process, which is a method that is getting more and more popular every day thanks to its many advantages in application, are ongoing. It is possible to pierce- the holes on a tube or sheet hydroformed part using hydropiercing method after the forming operation. In this study, hydropiercing process of a 304 stainless steel is simulated via the LS-Dyna in 2D axial symmetry model. In the simulations two types of punch movement was investigated to determine the contribution to the burr formation. In the simulations, Jonson-Cook hardening and damage model were used to determine the initiation of the crack on the samples. As a result, the burr formation can be eliminated by the two step movement of the punch through the piercing operation.
Free Vibration Modeling and Computation of Reinforced Thermoplastic Pipe (RTP) Conveying Fluid in Off/Inshore Industry Applications
Authors: Xu Lingyun , Abbas Laith K. , Chen Dongyang , Rui Xiaoting
Published: October 2018

Reinforced Thermoplastic Pipe (RTP) is a composite material flexible pipe. Due to RTP superior behavior, it encouraged the industry for using to offshore and inshore applications. Marine risers and cross-country pipelines resting on elastic medium are slender flexible structures conveying fluid and exhibit complex dynamic behaviors. Therefore, it requires accurate dynamic modeling for prediction the vibration characteristics. Transfer Matrix Method for Multibody Systems (MSTMM) is one of the sophisticated methods that can be used efficiently to model large systems and calculate its vibration characteristics and dynamic responses. The size of matrices in MSTMM remains small regardless of the number of elements in the model. Having smaller matrix sizes helps to have less computational expense leading to a faster answer. Based on the MSTMM advantages and Euler-Bernoulli linear theory, transfer matrix of the pipe in both offshore and inshore industry applications is built-up for vibration analysis. Recursive eigenvalue search algorithm is used to determine the system frequencies. Numerical examples are performed to validate with those published in the open literature.
A Generic and Modular Modeling Approach for Automotive Drivetrains Using a Coordinate Partitioning Method
Authors: Rumetshofer Johannes , Stolz Michael , Bachinger Markus , Horn Martin
Published: October 2018

Drivetrain models play an important role in state-of-the-art automotive drivetrain and control concept development. Based on a proposed set of elementary drivetrain components, this article contributes a generic straightforward approach to compute state-space models for various geared drivetrain layouts, including complex hybrid multi-mode transmissions. The modular approach follows Lagrange formalism: The free motion of rigid shafts is subsequently constrained, considering connecting elements like spur and planetary gear sets. The generalized coordinates are determined by a coordinate partitioning method, ensuring a physically reasonable coordinate system. The proposed approach features high potential for automation. This enables drivetrain modeling by non-experts in the field of mechanical engineering.
Correlation-regression models for calculating the weight of small-scale aircraft gas turbine engines
Authors: Filinov Evgeny , Kolmakova Daria , Avdeev Sergey , Krasilnikov Sergey
Published: October 2018

Several new correlation-regression models of weight calculation for small-scale aircraft gas turbine engines are proposed for their conceptual design stage. A comparison of the obtained weight models with each other and with the Kuz’michev model is carried out. Based on the obtained results, conclusions about the feasibility and scope of their application are drawn. New correlation-regression models differ from each other in the number of input parameters, as well as in the accuracy of forecasting the weight. In the course of the work, a database of main data and thermodynamic parameters of turbofan engines (TFE) is created consisting of 92 small-scale TFEs with thrust less than 50 kN. Based on the collected statistics, formulas were obtained that allow calculating the weight at the initial stage of engine design. The error in calculating the weight by these models is in range from 10% to 30%.
Design and Optimization of Micromilling Cutting Tools
Authors: Siregar Ikhsan , Saedon Juri Bin , Adenan Mohd Shariman
Published: October 2018

With the trend towards miniaturization, micromachining become more and more important in fabricating micro parts. The micromachining process that involved in this study is micro milling. The focus of the study is on the comparison performance between various numbers of flutes (4-flutes, 6-flutes and 8-flutes) with various helix angle (25º,30º and 35º) in micro end milling tool geometry with the conventional micro end milling, 2-flutes micro end milling. Cemented carbide is the material that been used for this study. The main problem about the two flutes micro end milling is it easily wears in a short time. In this study, finite element analysis of the model using cantilever beam principle theory. The tools will be modelled and simulate using Abaqus/CAE 6.10. The tool performance of the designed tool will be evaluated by using the maximum principal stress, σ_max. According to the analysis, weakest geometry is 2-flutes micro end milling and the strongest is 8-flutes micro end milling. 8-flutes micro end milling can be the option to replace the conventional micro end milling.
Experimental Research of the Usability on Double Acting Intensifiers in Hydroforming
Authors: Günaydın Ahmet Can , Halkacı Mehmet , Ateş Fatih , Halkacı Hüseyin Selçuk
Published: October 2018

The hydroforming method is especially used for forming lightweight materials like aluminum, magnesium alloys, high strength steels or materials that have limited formability. Intensifiers are the most important component of hydroforming presses. Nowadays single-acting intensifiers are used in hydroforming presses. Single-acting intensifiers provide pressurized liquid by forwarding movement of the piston through one direction and their volumes are limited. The mass of the intensifiers increases significantly depending on their liquid volume capacity and this causes high manufacturing costs. For this reason, two or more single-acting intensifiers which bridged in a parallel circuit are used to manufacture bigger products that require a high volume of liquid. But this method is not an economical solution. So double-acting intensifiers can overcome this problem. The pressurized liquid can be obtained during both forward and backward movement of the piston in double-acting intensifiers which work like a pump. This is why double-acting intensifiers have no volume limit on the contrary of single-acting intensifiers. Yet there are sudden pressure drops in double-acting intensifiers caused by returning movements of the piston to pressurize liquid again. This pressure drops cause some problems to use double-acting intensifiers on hydroforming method. The situation of solving this problem to use double-acting intensifiers on the hydroforming method can eliminate limited volume problem and decrease investment cost of hydroforming presses. In this study, the usability of double-acting intensifiers on hydroforming with die method was investigated. Because of the existing hydroforming press, used in experiments, doesn’t contain any double-acting intensifiers, pressure drops obtained by single-acting intensifier to perform simulated experiment. A die was designed and manufactured to synchronize the blank holder force with pressure drops. This die was integrated on the hydroforming press, located on Selcuk University Hydroforming Laboratory, for the success of the process. Performance of improved system was measured as well as repeatability of applying process parameters and product’s geometry were determined. The AA5754 aluminum alloy used processes, both single- and double-acting intensifier, were compared. Limiting drawing ratios were determined for all processes. It is obtained that pressure drops have no negative influence on formability. Moreover, there is no difference observed in thickness distribution which is an indicator of product’s quality and strength. However, when geometric accuracy was investigated then noticed that the pressure drops count has a good influence on product radius. 5.96 mm product radiuses on the process with single-acting intensifier was obtained 5.92 and 5.10 mm by using double-acting intensifier increasing pressure drop’s frequency.
Dual Axis Shadow Tracker
Authors: Dey A.K. , Nickey JVR , Sun Yanxia
Published: October 2018

Solar automatic fire tracker & extinguisher system is a new innovation technology and designed by our technology station (Process, Energy and Environmental Technology Station, University of Johannesburg) in combination with the characteristic of heat & fire detection apparatus. This industrial automation fire extinguisher have a platform with 90 degree of freedom and the DC motor base wheel will be passive or active, fixed or steerable according to system logic control unit to target a fire source. To get the system more effective and flexible the wheel will regulate with two characteristics: 1. Wheel spinning, 2. driving control. The whole system will operate by Solar energy source because it can be use in remote areas where it is too difficult to extend the electricity power grid connection to the fire extinguisher (solar extinguisher is not fix unit, it will always travel from one place to another place to find photon and detect flame). The most fun about the project is to watch him navigate from light source to light source trying desperately to stay alive. This character is the secondary operation when the battery status under the level of 60%.
Algorithmic Structure of Wind Turbines System based on an Induction Machine Directly Connected to the Grid
Authors: Nam Nguyen Huu , Mytsyk G.S , Berilov A.V , Thant Myo Min
Published: October 2018

One of the relatively simple (comparatively cheap) and promising solutions of the wind power plant - the wind turbine system (WTS) with variable speed on the shaft of the wind wheel - is to execute it on the basic of an induction machine - IM. Today, the problem of self-excited induction machine is solved in two ways - by using either capacitors, or electronic converters. As a generating system (based on IM), several WTS are often used, working parallel or directly connected to the grid. For induction machine: squirrel-cage induction generator (SCIG) and doubly-fed induction generator (DFIG) are used, several possible types of them are systematized, evaluated and compared on functional features and properties. Based on computer simulations, the ability of DFIG with back to back converters (in the form of two serially connected 2 level voltage source converters - converter-1 and converter-2) is determined in the rotor circuit at a variable speed of the drive shaft (in modes sub-synchronous and hyper-synchronous speeds) give to the grid only active power. For mass-scale and energy indicators, this structure is the optimum for WTS.
Research on Trajectory Planning of 6-DOF Cutting-robot in Machining Complex Surface
Authors: Jiao Sheng-xi , Wang Hao , Xia Lin-lin , Zhang Shuai
Published: October 2018

It is important and difficult for the complicated surface processing in mechanical industry. In this paper, an improved algorithm for trajectory planning is proposed in impeller surface processing by using 6-DOF cutting-robot. Taking a single finished path of the impeller blade as an example, the feedrate of the cutter, bow height error, cutter-orientation and position are planned by the B-spline interpolation algorithm, the best cutting trajectory is obtained. On the basis of trajectory planning, the optimal movement scheme of 6-DOF cutting-robot joints is obtained, the 6-DOF cutting-robot feedrate and trajectory smooth transition is achieved and the joints movement adaptive adjustment is completed. Finally, the angles, the angular velocitys of the joints and their interrelated properties are analyzed. The research works indicate that the robot joint angle curves are continuous and stable, which has met the requirements of smooth movement of the robot, and the results show that the trajectory planning is effective and practical.
Effective Robotics Education: Surveying Experiences of Master Program Students in Introduction to Robotics Course
Authors: Tsoy Tatyana , Sabirova Leysan , Magid Evgeni
Published: October 2018

Technology-driven world poses new challenges for the modern education system. To prepare skilled specialists for academic and industrial needs it is important to create competitive educational ground. Our team works on developing and implementing world-class master program in Intelligent Robotics. To pave the way for a high-quality educational program we invest efforts into studying students’ attitude and motivation for connecting their professional life with robotics. In this paper we describe the curriculum for master program that was designed and implemented at the Higher Institute of Information Technology and Information Systems at Kazan Federal University and present the results of our continuous research of comparative analysis of surveys among students of Introduction to Robotics course.
Selection of Parameters for 3D Finite-volume Mesh for CFD Simulation of Axial Turbines
Authors: Popov Grigorii , Matveev Valery , Baturin Oleg , Novikova Julia , Kolmakova Daria , Volkov Andrei
Published: October 2018

This article describes the second part of the global work done by the authors aimed at finding the best settings for a numerical model for calculations of axial uncooled turbines using the RANS approach. For the research, more than 1000 models of full-size axial turbines (including multistage turbines) and their elements were created. They differed in the number, size, parameters of the elements of finite volume meshes, in turbulence models, in the degree of simplification. The results were compared with the experimental data.

As a result, the following was obtained:

1. A method for developing and optimizing the working process of turbines using numerical simulation based on the RANS approach is proposed. The search for the optimal turbine configuration is carried out using light computational models, which are based on the simplified channel geometry and the finite volume mesh. Their application makes it possible to reliably find the optimal turbine configuration 2.8 times faster. The characteristics of the selected variants are verified with the help of verification models that consider the real geometry of the channels and have a minimum error.

2. Recommendations are given on the selection of parameters for finite volume meshes and the selection of turbulence models for numerical models of the working process of axial turbines designed to perform optimization and verification calculations.
Dynamic Modeling and Ground Test of Tethered-net
Authors: Qing-quan Chen , Qing-bin Zhang , Qian-gang Tang
Published: October 2018

Flexible tethered-net, a new kind of structure for advanced concepts in space exploration, has special potential application such as capturing space debris and building huge antenna. A critical issue in the design and analysis of space net system is deployment of modelling technology. The dynamics behaviour of flexible net systems is investigated based on finite segment approach in this paper. The flexible net is modelled as a series of collected semi-damp springs with masses lumped at appropriated nodes. Besides, a comprehensive study on a model for the tethered-net based on absolute nodal coordinates formulation (ANCF) is provided. Simulations show that the results based on the ANCF modelling method present a good agreement with that based on the conventional semi–spring damper modelling method. Then the flexible multibody dynamics models has been verified by comparison with ground experiment.
Simulative Study of Different Control Concepts of Cooling System for Machine Tools
Authors: Shabi Linart , Weber Juliane , Weber Jürgen
Published: October 2018

Power losses in machine tools, e.g. during the standby, idle-, and manufacturing process, are converted into heat energy. This causes the machine frame and other machine components to heat up. As a result, the Tool Centre Point (TCP) of the machine tools is moved. The accuracy of the machine is thus reduced during manufacturing. The current cooling system design of machine tools is based on a centrally fixed pump supply that provides a constant cooling volume flow for cooling all the machine tool components. This does not correspond to the individual temperature development of the components, after all, the high temperature fluctuation arises and causes the thermo-elastic deformation of machine tools. The main objective of this paper is to highlight the deficit of the current concept of cooling systems and to present a simulative study on the different controls concepts of cooling systems for machine tools. The results depict that the new concepts under consideration have a large potential for better thermal behaviour and lower hydraulic performance compared to the current cooling system design. The simulation results show a stability of the components’ temperature profile as well as a decreased energy consumption of the cooling system.
Effect of Intermetallic Compound Deposits on Wear Resistance and Microhardness on AISI 1020 Steel Substrate Using GTAW Process
Authors: Gill J.S. , Dhiman Sikandar Singh
Published: October 2018

Enhancing the oxidation resistance along with sufficiently improved mechanical properties of low carbon steel has always been a challenging task for surfacing industry. Modern automobile industry is looking for joining the dissimilar ferrous and non-ferrous metals to reduce the weight of the overall structure and not compromising the strength of the fabrications. This paper deals with the deposition of iron-aluminium intermetallic over a low carbon substrate using gas tungsten arc welding (GTAW) process. Oxidation resistance of the iron and aluminium metal powders deposits in varying ratios and few mechanical and metallurgical properties such as microhardness, microstructure and wear resistance were investigated and are reported in the present paper.
Process Parameter Optimization for Abrasive Water Jet Machining of Titanium Alloy Using Meta-Heuristic Algorithms
Authors: Sharma Vishal S , Kumar Amit , Gupta Munish Kumar , Bhanot Neeraj
Published: October 2018

Recently, the trend of optimization algorithms for improvements of surface quality and productivity characteristics in abrasive water jet machining of titanium alloy (Ti-6Al-4V alloy) has become increasingly more widespread in various industrial sectors i.e., aircraft and automobile Industries. Here, the present research attempts to select the ideal or best AWJM process parameters by implementing the well known meta-heuristic algorithm i.e., Teacher learning based optimization method (TLBO). The AWJM experiments as per the Taguchi L9 orthogonal array were performed on Ti 6Al-4V titanium alloy by considering jet transverse speed, stand-off distance and abrasive flow as the input parameters. Then, the influence of process parameters on surface roughness and material removal rate has been performed by means plot and ANOVA analysis. After that, the results are optimized with the TLBO method. The overall results indicate that the TLBO method is an efficient method used to find the optimal results with very short interval of time i.e., within 3 sec.