bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and anticancer cytotoxicity with structural context of an α-hydroxyphosphonate based compound library derived from substituted benzaldehydes
Authors: Rádai Zita , Windt Tímea , Nagy Veronika , Füredi András , Kiss Nóra Zsuzsa , Ranđelović Ivan , Tóvári József , Keglevich György , Szakács Gergely , Tóth Szilárd
Published: August 2019

We synthesized substituted benzaldehyde derived α-hydroxyphosphonates (αOHP), α-hydroxyphosphonic acids (αOHPA) and α-phosphinoyloxyphosphonates (αOPP) and characterized their cytotoxicity against a panel of cancer cell lines.
Ruthenium catalyzed chemo and site-selective C–H amidation of oxobenzoxazine derivatives with sulfonyl azides
Authors: Bakthadoss Manickam , Kumar Polu Vijay , Kumar Ravan , Surendar Manickam , Sharada Duddu S.
Published: August 2019

A novel and general protocol towards the synthesis of highly functionalized ortho-amido oxobenzoxazine frameworks via ruthenium catalyzed intermolecular C–H amidation using sulfonyl azides as amidation components has been developed for the first time.
Encapsulated liquid nano-droplets for efficient and selective biphasic hydroformylation of long-chain alkenes
Authors: Zhang Xiaoli , Wei Juan , Zhang Xiaoming
Published: August 2019

Rh-TPPTS aqueous droplets were confined within hollow nanospheres, leading to enhancements of catalytic activity and aldehyde selectivity in hydroformylation reactions.
Use of a bis-1,2,3-triazole gelator for the preparation of supramolecular metallogels and stabilization of gold nanoparticles
Authors: Tautz Markus , Saldías César , Lozano-Gorrín Antonio Diego , Díaz Díaz David
Published: August 2019

In this work, a series of functional metallogels have been prepared using a bis-1,2,3-triazole gelator prepared using the isosteric substitution method.
Tunable surface plasmon polaritons and ultrafast dynamics in 2D nanohole arrays
Authors: Gao Min , He Yonglin , Chen Ying , Shih Tien-Mo , Yang Weimin , Wang Jingyu , Zhao Feng , Li Ming-De , Chen Huanyang , Yang Zhilin
Published: August 2019

We have effectively tuned SPP modes across a broad spectral range and achieved a very narrow linewidth down to 8 nm. The contribution of conduction-band electron distribution to the SPP intensity has been explored by ultrafast fs-TA spectroscopy.
Altering CO binding on gold cluster cations by Pd-doping
Authors: Abdulhussein Heider A. , Ferrari Piero , Vanbuel Jan , Heard Christopher , Fielicke André , Lievens Peter , Janssens Ewald , Johnston Roy L.
Published: August 2019

Pd plays a crucial role in enhancing CO adsorption strength, through both direct and indirect means.
Optimised approach to albumin–drug conjugates using monobromomaleimide-C-2 linkers
Authors: Wall Archie , Nicholls Karl , Caspersen Mikael B. , Skrivergaard Stig , Howard Kenneth A. , Karu Kersti , Chudasama Vijay , Baker James R.
Published: August 2019

Monobromomaleimides with C-2-PEG linkers offer an optimised platform for site-selective albumin conjugation, offering efficient conjugation and accelerated stabilising hydrolysis which prevents loss of drug during construction.
Z-isomerization of retinoids through combination of monochromatic photoisomerization and metal catalysis
Authors: Kahremany Shirin , Sander Christopher Lane , Tochtrop Gregory P. , Kubas Adam , Palczewski Krzysztof
Published: August 2019

Photoisomerization of therapeutic cis-retinoids using monochromatic UV light-tunable via photocatalysts and explained by DFT calculations.
In situ epitaxial growth of Ag3PO4 quantum dots on hematite nanotubes for high photocatalytic activities
Authors: Duan Junyuan , Xu Leilei , Liu Youwen , Liu Bingxin , Zhai Tianyou , Guan Jianguo
Published: August 2019

Surface-adsorbed phosphate anions on Fe2O3 nanotubes can guide the in situ epitaxial growth of Ag3PO4 quantum dots on the nanotubes, efficiently improving the photogenerated charge transfer and photocatalytic activity.
Rice husk-derived Mn3O4/manganese silicate/C nanostructured composites for high-performance hybrid supercapacitors
Authors: Jiang Hanmei , Zhang Yifu , Wang Chen , Wang Qiushi , Meng Changgong , Wang John
Published: August 2019

Mn3O4/manganese silicate/C nanostructured composites were synthesized using rice husks and the hybrid supercapacitor realizes a maximum energy density of 13.3 W h kg−1 at 103.9 W kg−1 and super stability.
Removal of refractory organics in dinitrodiazophenol industrial wastewater by an ultraviolet-coupled Fenton process
Authors: Ran Gang , Li Qibin
Published: August 2019

In this study, ultraviolet-Fenton process was applied to degrade refractory organics in dinitrodiazophenol industrial wastewater. In addition, the treatment efficiency and reaction mechanism were systematically investigated.
Effects of N-oxidation on the molecular and crystal structures and properties of isocinchomeronic acid, its metal complexes and their supramolecular architectures: experimental, CSD survey, solution and theoretical approaches
Authors: Hosseini-Hashemi Zahra , Mirzaei Masoud , Jafari Ameneh , Hosseinpour Peyman , Yousefi Mohammad , Frontera Antonio , Lari Dashtbayaz Mahmoud , Shamsipur Mojtaba , Ardalani Mehdi
Published: August 2019

A series of new coordination complexes bearing H2pydco, an O-donor ligand, were synthesized and compared to corresponding complexes with H2pydc. The molecular and supramolecular structures were investigated using crystallography, solution phase and high level DFT studies.
Selective catecholamine detection in living cells by a copper-mediated oxidative bond cleavage
Authors: Tong Ka Yan , Zhao Jia , Tse Chun-Wai , Wan Pui-Ki , Rong Jianhui , Au-Yeung Ho Yu
Published: August 2019

A copper-mediated oxidative bond cleavage induced by catecholamines is developed into a turn-on fluorescent probe for imaging of the neurotransmitter in living cells.
Dissipation and strain-stiffening behavior of pectin–Ca gels under LAOS
Authors: John Jacob , Ray Debes , Aswal Vinod K. , Deshpande Abhijit P. , Varughese Susy
Published: August 2019

Calcium mediated crosslinking in pectin gels results in different network structures with distinct non-linear rheological signatures.
A wood–polypyrrole composite as a photothermal conversion device for solar evaporation enhancement
Authors: Wang Zhe , Yan Yutao , Shen Xiaoping , Jin Chunde , Sun Qingfeng , Li Huiqiao
Published: August 2019

A wood–polypyrrole composite as a photothermal conversion device for efficient seawater desalination and water purification.
Accelerated discovery and mechanical property characterization of bioresorbable amorphous alloys in the Mg–Zn–Ca and the Fe–Mg–Zn systems using high-throughput methods
Authors: Datye Amit , Alexander Kube Sebastian , Verma Devendra , Schroers Jan , Schwarz Udo D.
Published: August 2019

High throughput discovery of amorphous bioresorbable alloys. Top: combinatorial sputtering setup. Bottom: composition of libraries deposited on silicon (Si) wafers for (a) magnesium (Mg)–zinc (Zn)–calcium (Ca) and the (b) iron (Fe)–Mg–Zn systems.
AMPK: a balancer of the renin–angiotensin system
Authors: Liu Jia , Li Xuan , Lu Qingguo , Ren Di , Sun Xiaodong , Rousselle Thomas , Li Ji , Leng Jiyan
Published: August 2019

The renin–angiotensin system (RAS) is undisputedly well-studied as one of the oldest and most critical regulators for arterial blood pressure, fluid volume, as well as renal function. In recent studies, RAS has also been implicated in the development of obesity, diabetes, hyperlipidemia, and other diseases, and also involved in the regulation of several signaling pathways such as proliferation, apoptosis and autophagy, and insulin resistance. AMP-activated protein kinase (AMPK), an essential cellular energy sensor, has also been discovered to be involved in these diseases and cellular pathways. This would imply a connection between the RAS and AMPK. Therefore, this review serves to draw attention to the cross-talk between RAS and AMPK, then summering the most recent literature which highlights AMPK as a point of balance between physiological and pathological functions of the RAS.
Expression profiles and potential functions of long non-coding RNA in stable angina pectoris patients from Uyghur population of China
Authors: Zhou Xin-Rong , Song Ning , Luo Jun-Yi , Zhai Hui , Li Xiang-Mei , Zhao Qian , Liu Fen , Li Xiao-Mei , Yang Yi-Ning
Published: August 2019

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nt that are involved in cardiovascular diseases (CVDs). To determine whether lncRNAs are involved in stable angina pectoris (SAP), we analysed the expression profile of lncRNAs and mRNAs on a genome-wide scale in SAP of Uyghur population. Five pairs of SAP patients and healthy controls were screened by an Agilent microarray (human lncRNA + mRNA Array V4.0). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the lncRNA expression levels in 50 SAP and 50 controls. Data analyses were performed using R and Bioconductor. A total of 1871 up- and 231 down-regulated lncRNAs were identified to be differentially expressed in the peripheral blood mononuclear cells (PBMCs). Microarray analysis results identified the lncRNAs NR_037652.1, ENST00000607654.1, ENST00000589524.1 and uc004bhb.3, which were confirmed by qRT-PCR. Among screened lncRNAs, the annotation result of their co-expressed mRNAs showed that the most significantly related pathways were the NF-κB signalling pathway, apoptosis and the p53 signalling pathway, while the main significantly related diseases were the cholesterol, calcium and coronary disease. Our study indicated that clusters of lncRNAs were significantly differentially expressed between SAP patients and matched controls. These lncRNAs may play a significant role in SAP development and could serve as biomarkers and potential targets for the future treatment of SAP.
Workflow composition and analysis in Industry 4.0 warehouse automation
Authors: Kattepur Ajay
Published: August 2019

Workflow compositions have been exploited in business process modelling to handle concurrent invocations of modular components. With the emergence of Industry 4.0 warehouse automation, which enable the integration of business processes, mechanised robots, sensor–actuators and human participants, analysis and specification of workflows become crucial. As such environments have dynamic deployments due to varying demand rates and environmental conditions, the workflow compositions are intended to be adaptable to runtime changes. In addition, monitoring the end‐to‐end latency and optimal runtime binding is critical in industrial deployments such as warehouse automation. The authors provide specifications in the concurrent programming language Orc that supports most commonly used workflow patterns. Complex deployments involving multiple robotic agents and business processes further require analysis of correctness, liveness, and safety properties. In order to verify the workflows, the Orc specifications are translated into workflow net representations, with verification done using the TAPAAL model checker. The advantages of deploying fine grained analysis of workflows are demonstrated over picker/delivery robots involved in warehouse operations. The envisioned set of reusable specifications may be extended and applied to a variety of Industry 4.0 deployments to handle complex workflow interactions.
Discretisation performance analysis of sliding mode controlled DC–DC buck converter via zero‐order holder
Authors: Wang Cong , Xia Hongwei , Wang Yanmin , Mai Yongfeng , Ren Shunqing
Published: August 2019

This study investigates the discretisation effects of the zero‐order holder (ZOH) on DC–DC buck converters under the direct ON/OFF control of sliding mode (SM), and the two core issues of stability and periodicity for the discrete system are focused on. The optimal parameter for the SM controller is first given on the basis of stability and response speed in the continuous‐time domain, following its ZOH discretisation. Restricted by the existence condition of discrete SM, the guaranteed stability is investigated and compared with that of the continuous system in the phase plane, proving that the sampling time of ZOH affects its stability region. Meanwhile, the periodic dynamics, including the system state and the symbolic sequence of switching control law, is further studied via analysing the steady limit cycle of state in phase plane; and the existence condition of multi‐periodicity is also deduced. Innovatively this study establishes the influence relationship of the periodic dynamics with the performances of the steady‐state error of output voltage and switching frequency. Simulation and experiment results are presented to validate the theoretical and practical value of the proposed research.
Optimal allocation of ELC in microgrid using droop controlled load flow
Authors: Uniyal Ankit , Sarangi Saumendra
Published: August 2019

The increased renewable‐based sources penetration in the microgrid (MG) has given rise to issues related to the voltage (V) and frequency (f) surpassing their tolerance limits, especially during off‐peak hours. The fluctuations in V and f could be handled by available real‐time control schemes within a specified range. Owing to the wide generation‐load mismatch in the high‐penetration scenario, deviations in V and f cannot be sorted out using available real‐time control schemes and seeks further developments. An electronic load controller (ELC) in the MG can consume excess generation to regulate V and f. Hence, this work presents an analytical study to understand the significance of ELC in highly penetrated MGs in V and f regulation at off‐peak hours. The problem is formulated as single‐ and multiple‐optimisation problems, which are solved using heuristic techniques viz. particle swarm optimisation and non‐dominated sorted genetic algorithm‐II. To incorporate the effect of P–f and Q–V droop characteristics as exhibited by distributed generations in the power flow, a special load flow method is used. The analysis is conducted on IEEE 33‐and 69‐bus test systems modified as autonomous MGs. The results show that proposed method is capable of minimising V and f deviation.
Multi‐layered dual‐mode substrate integrated waveguide bandpass filter with input and output ports located on same substrate layer
Authors: Liu Qing , Zhou Dongfang , Lv Dalong , Zhang Dewei , Zhang Junjie , Zhang Yi
Published: August 2019

This study reports a multi‐layered dual‐mode substrate integrated waveguide (SIW) bandpass filter (BPF), in which the input and output ports are located on the same substrate layer (i.e. the upper one). The dual‐mode SIW cavity in the lower substrate layer is coupled to the upper dual‐mode SIW cavity by two crossed slots, which can independently control the inter‐couplings. The proposed filter can be modelled by a dual‐extended doublet coupling scheme with considering bypass couplings between source and load. Based on the proposed structure, single‐ and dual‐band filtering responses with four controllable finite‐transmission zeros (FTZs) are realised and analysed. For the demonstration, a single‐band filter and a dual‐band filter were fabricated and measured. The measured results agree well with simulated ones.
Manifold ambiguity and performance analysis for electric‐measurement‐only polarisation sensitive arrays
Authors: Zhao Chunlei , Mao Xingpeng , Yang Yunlong , Yu Changjun
Published: August 2019

Direction‐of‐arrival and polarisation estimation is an important issue in array signal processing. Among various polarisation sensitive arrays (PSAs), arrays with only measurements of the electric field are most extensively applied in practice. In this study, the manifold ambiguity of such electric‐measurement‐only PSA is investigated to evaluate the uniqueness of parameter estimation. For co‐centred PSAs and spatially‐spread PSAs, the necessary and sufficient conditions of linearly dependent steering vectors are established based on the cosine similarity. Furthermore, for various arrays, the explicit parameter sets corresponding to trivial manifold ambiguity are provided. Moreover, for the noisy case, the closed‐form Cramér‐Rao bounds for arbitrary PSAs are also presented to evaluate the performance bound of parameter estimation with the considered arrays. Simulations and experimental results of high‐frequency radar further reveal the influences of array configurations on the identifiability and performance bound of PSAs, and verify the corresponding theoretical results. The presented results can be easily generalised to other PSAs containing magnetic measurements, which provide guidelines for designing the spatial and polarimetric configuration of PSAs to ensure unambiguous and accurate parameter estimation.
Application and analysis of an electronic–mechanical dual stable platform for radars with a three‐axis stable turntable
Authors: Lv Xiangyang
Published: August 2019

This study proposes the concept of an electronic–mechanical dual stable platform for radars with a three‐axis stable turntable. Based on an assumption, an electron stable equation of the first order is applied to the beam pointing correction of the radar with three‐axis stable turntable based on the equivalence principle. Furthermore, through a comparative analysis of two kinds of algorithms, it is shown that when the instantaneous value of the tracking error in the platform servo‐loop of the mechanical platform is smaller than a certain range, assuming the conditions are established, the error method of the electron stable equation of the first order can directly replace the electron stable equation of the second order that is applied to the spatial orientation correction of the radar beam to improve computational efficiency. At the same time, error analysis was performed on the data link of the dual stable platform.
W‐band low‐sidelobe series‐fed microstrip antenna array based on impedance matching section weighting method
Authors: Song Song , Wang Wei , Wang Xuetian
Published: August 2019

A W‐band low‐sidelobe series‐fed microstrip antenna array is proposed here. Impedance matching section weighting method is used in element series‐fed weighting. This feeding method can effectively realise the desired amplitude distribution and sidelobe level of −30.1 dB is obtained in this design. The designed low‐sidelobe antenna has great practical value in antenna of W‐band portable radar.
Study on ISAR imaging for forward‐looking missile‐borne millimetre wave radar
Authors: Wen Cai , Zhu Jiang , Zhou Yan , Peng Jinye
Published: August 2019

Target recognition is a challenging problem in air‐to‐surface terminal guidance for missile‐borne millimetre wave radar (MWR). The class of high range resolution profile (HRRP)‐based automatic target recognition approaches is sensitive to the attitude of target. One effective way to improve the performance of target recognition is acquisition of multidimensional information from target's image. Here, 2D ISAR imaging of the ground static target for the forward‐looking missile‐borne MWR is studied. The relative signal model and some key points are analysed. The effectiveness of the proposed approach is demonstrated by simulation and real data processing results.
Improved weighted least‐squares phase unwrapping method for interferometric SAR processing
Authors: Hui Yu , Wenying Wang , Long Zhuang , Wanming Lei , Xin Nie , Pin Li
Published: August 2019

Based on the study of existed least‐squares and weighted least‐squares phase unwrapping methods, an improved weighted least‐squares algorithm based on unwrapping phase error compensation is proposed. First, the conventional weighted least‐squares method is used to get the initial result of phase unwrapping. Then the unwrapping result is optimised by iterative compensation of phase unwrapping error. In addition, for the reasonable selection of the times of iteration, an iterative mechanism is designed to avoid the redundant or insufficient compensation caused by too many iterative times and too few. Compared with the traditional weighted least‐square method, by using the proposed method, the global influence of phase noise is constrained by weighted processing, and meanwhile, the accuracy of phase unwrapping is greatly improved by iterative error compensation. The simulation results confirm the superiority of the proposed method.
The diverse lives of progenitors of hydrogen-rich core-collapse supernovae: the role of binary interaction
Authors: Zapartas Emmanouil , de Mink Selma E. , Justham Stephen , Smith Nathan , de Koter Alex , Renzo Mathieu , Arcavi Iair , Farmer Rob , Götberg Ylva , Toonen Silvia
Published: August 2019

Hydrogen-rich supernovae, known as Type II (SNe II), are the most common class of explosions observed following the collapse of the core of massive stars. We used analytical estimates and population synthesis simulations to assess the fraction of SNe II progenitors that are expected to have exchanged mass with a companion prior to explosion. We estimate that 1/3 to 1/2 of SN II progenitors have a history of mass exchange with a binary companion before exploding. The dominant binary channels leading to SN II progenitors involve the merger of binary stars. Mergers are expected to produce a diversity of SN II progenitor characteristics, depending on the evolutionary timing and properties of the merger. Alternatively, SN II progenitors from interacting binaries may have accreted mass from their companion, and subsequently been ejected from the binary system after their companion exploded. We show that the overall fraction of SN II progenitors that are predicted to have experienced binary interaction is robust against the main physical uncertainties in our models. However, the relative importance of different binary evolutionary channels is affected by changing physical assumptions. We further discuss ways in which binarity might contribute to the observed diversity of SNe II by considering potential observational signatures arising from each binary channel. For supernovae which have a substantial H-rich envelope at explosion (i.e., excluding Type IIb SNe), a surviving non-compact companion would typically indicate that the supernova progenitor star was in a wide, non-interacting binary. We argue that a significant fraction of even Type II-P SNe are expected to have gained mass from a companion prior to explosion.
He Iλ10 830 Å in the transmission spectrum of HD209458 b
Authors: Alonso-Floriano F. J. , Snellen I. A. G. , Czesla S. , Bauer F. F. , Salz M. , Lampón M. , Lara L. M. , Nagel E. , López-Puertas M. , Nortmann L. , Sánchez-López A. , Sanz-Forcada J. , Caballero J. A. , Reiners A. , Ribas I. , Quirrenbach A. , Amado P. J. , Aceituno J. , Anglada-Escudé G. , Béjar V. J. S. , Brinkmöller M. , Hatzes A. P. , Henning Th. , Kaminski A. , Kürster M. , Labarga F. , Montes D. , Pallé E. , Schmitt J. H. M. M. , Zapatero Osorio M. R.
Published: August 2019

Context.Recently, the He Itriplet at 10 830 Å was rediscovered as an excellent probe of the extended and possibly evaporating atmospheres of close-in transiting planets. This has already resulted in detections of this triplet in the atmospheres of a handful of planets, both from space and from the ground. However, while a strong signal is expected for the hot Jupiter HD 209458 b, only upper limits have been obtained so far.

Aims.Our goal is to measure the helium excess absorption from HD 209458 b and assess the extended atmosphere of the planet and possible evaporation.

Methods.We obtained new high-resolution spectral transit time-series of HD 209458 b using CARMENES at the 3.5 m Calar Alto telescope, targeting the He Itriplet at 10 830 Å at a spectral resolving power of 80 400. The observed spectra were corrected for stellar absorption lines using out-of-transit data, for telluric absorption using theMOLECFITsoftware, and for the sky emission lines using simultaneous sky measurements through a second fibre.

Results.We detect He Iabsorption at a level of 0.91 ± 0.10% (9σ) at mid-transit. The absorption follows the radial velocity change of the planet during transit, unambiguously identifying the planet as the source of the absorption. The core of the absorption exhibits a net blueshift of 1.8 ± 1.3 km s−1. Possible low-level excess absorption is seen further blueward from the main absorption near the centre of the transit, which could be caused by an extended tail. However, this needs to be confirmed.

Conclusions.Our results further support a close relation between the strength of planetary absorption in the helium triplet lines and the level of ionising, stellar X-ray, and extreme-UV irradiation.
Vibration suppression for high speed railway bridges using fluid viscous dampers
Authors: Tahiri M. , Khamlichi A. , Bezzazi M.
Published: August 2019

The results of experimental and theoritical investigations of railway bridges have shown the significant dynamic responses exceeding that anticipated on certain railway bridges, such as a resonance phenomenon who have a great effect in the bridge. Alternatively , the use of structural control systems devices might be a very promising solution to attenuate undesirable vibration. The aim of this study, first, is to investigate the posibility of reducing the acceleration in an acceptable level by using fluid viscous dampers. The bridge-damper system is described by a single-degree-of-freedom model. The ,dampers are connected between the bottom surface of the bridge deck and the abutment, Finallay a linearisation model and a comparative study in order to investigate the effect of the nonlinearite of the device in the dynamic response of the system.
Concentrated stress location areas for welded tubular T-joints under deflected bending load
Authors: Chouha E. , Jalal S.E. , El Maskaoui Z. , Chouaf A.
Published: August 2019

The welded tubular joints can be used in several industrial fields including, metallic bridges, telecommunication tripods, oil platforms and pipelines. These structures can be damaged by concentrated stresses located in the toe weld vicinity. Semi-parametric formulas, currently available in the literature, can be used to predict the value of the stress concentration factor without given the hot spot location. In this work, a Finite Elements modeling was carried out for a T-joint, in order to have the concentrated stress value around the weld toe. This work was investigated for a series of combined loads.
Analytical Modelling of Elastic Interference Fit Joints for Functionally Graded Materials
Authors: Belhaou M. , Laghzale N.
Published: August 2019

For a very long time, fretted assemblies have been made, in particular to provide wooden wheels with a more resistant running surface. Today, shrinking is an operation which consists in making a connection between two cylindrical parts with any material. In this paper, we’re going to apply it for functionally graded materials. This work focuses on the analytical development of the residual stresses when the two assembled parts are circular cylinders and elastic deformation under plane strain condition. Both cylinders are made of functionally graded materials whose volume fractions are power functions of the radius. In order to simplify the calculations, we assume the Poisson’s ration constant. We obtain the theoretical solutions by assuming a uniform strain field within the representative volume element and Von-mises criterion.
Reducing drag on a flat plate subjected to incompressible laminar flow
Authors: Agriss A. , Agouzoul M. , Ettaouil A.
Published: August 2019

The idea behind this work comes from the question: What is the impact of plate corrugations on drag? In this context, a numerical study of laminar incompressible flow over a flat plate and over corrugated plates is carried out. Numerical analysis is performed for low Reynolds numbers (Re= 10, Re = 50, Re = 100, Re = 500, Re =1000) using the computational fluid dynamics (CFD) software ANSYS FLUENT. Simulations results are compared to each others and with those of the reference plate (flat plate (figure 4a)). Comparisons are made via drag coefficient Cd. This work is the beginning of a study that evaluates the impact of corrugations on drag reduction on a flat plate.
Instability of a viscous interface under horizontal quasi-periodic oscillation
Authors: Assoul M. , El Jaouahiry A. , Echchadli M. , Aniss S.
Published: August 2019

We study the linear stability of two superposed layers of viscous, immiscible fluids of diﬀerent densities. The whole system is subject to horizontal quasi-periodic oscillation with two incommensurates frequencies ω1 and ω2. The spectral method and Floquet’s theory combined with Runge-Kutta method are used to solve numericelly the linear problem. We analyse the influence of the frequencies ratio$ \omega = {{{\omega _1}} \over {{\omega _2}}} $, on the mariginal stability. The numerical solution shows that the quasi-periodic excitation has a stabilizing or a destabilizing eﬀect on the Kelvin-Helmholtz instability as well as in the parametric resonances depending on the frequency ratio and the amplitudes ratio $ \alpha = {{{\alpha _2}} \over {{\alpha _1}}} $.
Separation stability in binary mixtures with negative Soret numbers
Authors: Šeta B. , Lapeira E. , Dubert D. , Gavalda F. , Bou-Ali M.M. , Ruiz X.
Published: August 2019

In the present work, by using a paralelepipedic thermogravitational microcolumn, the temperature gradient influence on the stability of the flow was or has been examined, emphasizing mixtures with negative Soret coefficients. Experiments and numerical analysis were conducted for DCMIX2 Toulene-Methanol binary subsystem. This binary subsystem has a broad range of negative Soret values for low concentrations of Methanol which was analysed. Two different concentrations have been studied in order to confirm existence of temporal stability windows of those mixtures. Experiments were compared with numerical simulations conducted in open source software OpenFOAM, for both cases.
Numerical study of an impeller design for a new ventricular assist device
Authors: Bounouib M. , Es-Sadek M.Z. , Taha-Janan M. , Maazouzi W.
Published: August 2019

This work presents a numerical study of two new designs of an axial ventricular assist device (VAD). The aim of study will be to choose the better of the two designs in terms of hemolysis and thrombosis. For this purpose, an analysis of the flow generated by the rotors is carried out in order to identify the critical zones for the two major problems cited above.
Ground measurements of dcmix 4 project Fullerene based nanofluid
Authors: Mounir Bou-Ali M. , Errarte A. , Mialdun A. , Shevtsova V. , Schraml M. , KÖhler W.
Published: August 2019

This work presents first on ground measurements of DCMIX 4 project ternary nanofluid Fullerene, 1,2,3,4-tetrahydronaphtalene and Toluene. Transport properties have been measured by Thermogravitational, Optical Digital Interferometry and Optical Beam Deflection techniques for concentration analysed in DCMIX 4 project, which refers to 0.0007 – 0.60 – 0.3993 and other fullerene concentrations around this value. Various thermophysical and optical properties which are necessary to determine thermodiffusion coefficients have been also measured.
Numerical study concerning the influence of contact ratio at helical involute gears
Authors: Gabroveanu Sorin , Cananau Sorin , Mirica Radu-Florin
Published: August 2019

In the present paper some aspects of the influence of the overlap ratio of the gear set on its dynamic comportment was studied. In this aim, the values of angular acceleration of two helical involute gear sets having the same characteristics - excepting the face width - are determined. The study is performed using a software in the category of The Multibody Dynamics Simulation Solution for simulation the dynamic comportment for various width of the driven gear, at various torques and various angular velocities.
Fast tooth root load capacity optimization based on improved design of hob geometry
Authors: Uelpenich Ray , Tenberge Peter
Published: August 2019

The competitiveness of gearboxes is significantly influenced by their performance ability. Increasing the tooth root load capacity has always been in focus of current research because in case of a failure of the gearwheel due to a tooth root fracture, the complete gearbox fails. This paper presents a new calculation method that enables the optimization of hob geometries within a few minutes so that they lead to reduced stresses in the tooth root fillet of spur gears. This results in reductions of the maximum tooth root stress of 10% and more for most gearwheels. The manufacturing costs for the optimized hob are only influenced slightly. In order to increase the computational speed compared to purely FE-based optimization methods, the present paper shows a method in which the decisive part of the optimization process is based on an analytical equation which are derived by a small number of FE-calculations.
Fast modelling and simulation of the dynamic behaviour of a wet multidisc clutch during the engagement phase
Authors: Rogkas Nikolaos , Vasileiou Georgios , Tsolakis Efstratios , Spitas Vasileios , Zalimidis Pavlos
Published: August 2019

In recent years multidisc wet friction clutches are of great importance to manufacturers of automatic transmissions (ATs) for the automotive industry, particularly since the introduction of double-clutched ATs. Their main advantage compared to their dry-friction counterparts is that they ensure smooth engagement, high reliability and long service life. Their progressive engagement due to the developed Couette flow between the discs enables them to be used both as clutches and as brakes in order to control power flow in simultaneously engaged geared shafts in the AT. Due to the coupled nature between the mechanical and the fluid dynamics regimes governing their operation, these systems are highly complex to be treated analytically and instead numerical approaches have proven to provide better results. However, the numerical treatment of such problems provides only case-specific results, which cannot be generalised and are not able to provide a general insight in the complex dynamics of the device. Furthermore the computational cost and the associated modelling and simulation effort during the design phase is high, making the incorporation of such methods in iterative design processes and algorithms counterproductive. In this paper the modelling of the dynamic behaviour of a wet multidisc clutch during the engagement phase is performed, via the combination of analytical and numerical methods and conclusions are drawn about the effect of the main geometric, kinematic and dynamic design parameters on the clutch’s response. The dynamic modelling is performed by applying the principle of linear and angular momentum on each disc. The effect of the fluid film is taken into account through the solution of the governing Navier-Stokes equations via CFD analysis or by the use of semi-analytical solutions with high accuracy, where applicable. Therefore both the developed pressure field and the torque of the fluid film are calculated efficiently and used in the simulation of the system. The flow is assumed to be laminar and the discs rigid and flat.
Study of spindle drives for boring machines
Authors: Zhilevski Marin , Mikhov Mikho
Published: August 2019

This paper examines the main requirements for the electric drive systems of a class of boring machines with digital program control. On this basis, a methodology for choice of the spindle drives is offered. The algorithm takes into account the specific features of the technological processes, the treated materials, the tools used and their wear, as well as the mechanical gear types. The experimental studies of the implemented electric drives for the spindle are presented and discussed. The research carried out and the results obtained can be used in the development of such drives for the studied class of machine tools.
Vibration analysis of multi-body dynamic model of combat vehicle gearbox
Authors: Furch Jan , Tran Cao Vu
Published: August 2019

The combat vehicle gearbox, during the operation, generates vibration signals being related to the technical condition of gearbox. The analysis of the vibration signal could be used to determine accurately the behaviour of gearbox. Along with the development of the computer technology, the multi-body dynamic solution has been used widely to simulate, analyse, and determine the technical condition of gearbox. The purpose of this paper is to introduce the dynamic model of combat vehicle gearbox, and the simulation process based on the multi-body dynamic software, namely MSC.ADAMS. This proposed model allows the detection of failure conditions of individual gears and bearings in the gearbox. In this way, the fault conditions of the individual transmission components are identified. In the future, we would like to include a material wear module in the model, and we would like to model the life of the gearbox. We assume that we would also carry out accelerated tests of the gearbox to verify validity.
Modelling and researching of forced spatial vibrations of axial fans
Authors: Slavov Valentin , Vukov Georgi
Published: August 2019

This work presents a mechanic - mathematical matrix modelling of the forced spatial vibrations of an axial fan. The axial fan is considered as a mechanical system consisting of three rigid bodies and with 18 degrees of freedom. The differential equations of the forced vibrations are derived. They take into account the mass, inertial, elastic, damping and geometric characteristics of this mechanical system. Algorithms are developed for computer calculating, analysis and synthesis of the design of this axial fan. These algorithms are a prerequisite for achieving the required operational properties of the fan and its compliance with the standards and regulations for vibrations’ impact on the human body. Calculations and results of the forced spatial vibrations are provided for specific parameters of the mechanical system.
Influence of remetalizer "Rimet" on treatment of the bearing alloy
Authors: Komitov Georgi
Published: August 2019

At repair-restorely works exist technological influence on work surface of details, which sizable the intensive lower of running rubbing and wear out processes. Between rubbing surfaces begin forming of new layer with thickness in proportion of the wear out, in result of this the friction between the surfaces is decrease. This article present the influence of additive "Rimet" to variation of wear out, change of roughness and speed of wear out. The research are conducted on machine for rubbing and wear out "MRW-1", over rubbing couple in type "tempered steel - bearing alloy". At research are received datas for weight change on roll and bearing alloy AO-20 and BO-30. also the values of the change of the geometry of the rolls and the change of the rolls and bearing alloys roughness by several sections. The received results are giving possibility for rating of ongoing processes at using additive "Rimet" on tracking of treatment and wear out stability of rubbing couples from "shaft-bearing".
Automation of fuzzy multi-criteria selection of robotic machine-assembly technologies using worst-case approach
Authors: Kyrylovych Valery , Dimitrov Lubomir , Kryzhanivska Ilona , Melnychuk Petro
Published: August 2019

In this paper a new method of selection of robotic machine-assembly technology is presented. The core of the technology suggested is the method of fuzzy multi-criteria alternatives selection using the worst-case approach. The automation of the proposed solution is based on the original WMS (Worst Method Solution) software, developed by authors. In the basis of this software are the ideas of robotic machine-assembly technology and its theoretical formalization.
Experimental studies of the structure of biological tissues through mechanical effects with a smart laparoscopic instrument
Authors: Ivanova Veronika , Batchvarov Ditchko , Ilcheva Zlatoliliya , Boneva Ani , Ilchev Svetozar , Alexandrov Alexander , Andreev Rumen
Published: August 2019

The article presents investigations in the area of the analysis of heterogeneous biological tissues using tools based on mechanical stimulations. Some known tissue mechanical models are presented along with one approach for specifying the tissue internal structure by measuring mechanical macro parameters of the research tools. The methodology of micro and macro stimulation is described and the construction of an experimental model of a smart laparoscopic tool for its realization is presented.
Research on the Technological Development of GSO Small Satellite
Authors: Jie Geng , Jinggang Gong , Zuowei Wang , Nan Lyu
Published: August 2019

The application and technological development of geosynchronous orbit(GSO) small satellite are researched in this paper. Firstly the application field and application value of GSO small satellites are analysed. Secondly, the technology development status of foreign GSO small satellites is overviewed. Then the differences and similarities among GSO small satellite, traditional large satellite and low earth orbit(LEO) small satellite are compared, and characteristic and key technique are systematically studied. Finally, for China’s future military and civilian needs, combined with the development trend of modern small satellite technology, the preliminary proposal for the development of China’s GSO small satellite are given.
Numerical Study on Internal flow Field Dynamic Performance of Scramjet
Authors: Gao Feng , Zhao Jie , Chen Feng Li
Published: August 2019

The pressure pulsation caused by the combustion of the combustion chamber of the scramjet engine has a great influence on the flow and performance of the inlet. Although the isolation section prevents the propagation of this pressure pulsation, the pressure pulsation still flows to the inlet flow field. And performance has an adverse effect. In this paper, a method for calculating the dynamic performance parameters of the inlet is discussed. The influence of the pulsating pressure of the combustion chamber on the performance of the inlet is preliminarily studied. The influence law of different forms of back pressure pulsation on the flow coefficient and the total pressure recovery coefficient is obtained. Different back pressure pulsation forms have a great influence on the flow coefficient. The faster the response, the more obvious the change of the flow coefficient. The larger the reduction, the more likely the inlet channel will not start. Different back pressure pulsations have little effect on the total pressure recovery coefficient. In the design of the intake port, the influence of the back pressure pulsation on the performance of the intake port should be fully taken into consideration, and measures should be taken to prevent the performance of the intake port from being affected by the back pressure pulsation.
Involvement of polyunsaturated fatty acids in the control of energy storage and expenditure
Authors: Pisani Didier F. , Ailhaud Gérard
Published: August 2019

Within heterotrophic organisms, fat, sugar and protein are required to bring energy. In humans, energy homeostasis (i.e.the balance between energy intake and energy expenditure) is tightly regulated. Obesity, characterized by an excess of white fat mass, is a consequence of dysregulation of this balance in which decreased energy expenditure plays an important role. Among dietary components, fat represents approximately 30% of daily intake. Recent studies have shown that, besides its caloric input, fatty acid composition of fat represents an important qualitative issue. The impact of ω6 and ω3 polyunsaturated fatty acids on weight gain and development has been extensively studied. Interestingly, the role played by these polyunsaturated fatty acids in energy expenditure has been also characterized and will be discussed in relation to the various organs involved, in particular brown adipose tissue.
Benzodiazepine und Z-Substanzen – Analyse der kassenärztlichen Verschreibungen von 2006 bis 2015
Authors: Verthein Uwe , Buth Sven , Holzbach Rüdiger , Neumann-Runde Eike , Martens Marcus-S.
Published: August 2019

Es wird untersucht, wie sich die kassenärztlichen Verschreibungen von Benzodiazepinen (BZD) und Z-Substanzen (ZS) über einen 10-Jahres-Zeitraum entwickelt haben. GKV-Rezepte des Norddeutschen Apotheken-Rechenzentrums (NARZ) wurden für Schleswig-Holstein, Hamburg, Niedersachsen und Bremen von 2006 – 2015 ausgewertet. 1,64 Mio. Patienten erhielten Verschreibungen von BZD und/oder ZS im 10-Jahres-Zeitraum. 65,3 % sind Frauen, über die Hälfte sind 60 Jahre oder älter. Der Anteil an Patienten mit leitliniengerechten Verschreibungen steigt von 51,7 % in 2006 auf 60,2 % in 2015. Problematische Verschreibungen gehen von 34,8 % auf 27,1 % zurück. Der Anteil leitlinienabweichender Verschreibungen von BZD und ZS, die auf Missbrauch oder Abhängigkeit deuten, ist unter GKV-Patienten seit vielen Jahren rückläufig.
Medikamentöse Komplextherapie – Arzneimittelinteraktionen von Valproat und Metamizol
Authors: Kliem Anna , Green Kim , Mattern Margarete
Published: August 2019

Die klinische Relevanz der Medikamenteninteraktion zwischen Valproat und Metamizol soll anhand eines Patientenfalls aus der Gerontopsychiatrie dargestellt werden. Es besteht die Annahme, dass Metamizol in der Dosierung von 4 g/d einen relevanten Einfluss auf den Valproatspiegel und das klinische Outcome hat. Dies könnte auf einer CYP2B6-Induktion und gesteigerten Metabolisierung des Valproats beruhen. Im Falle einer Kombinationsbehandlung von Valproat mit Metamizol sind somit engmaschige Kontrollen des Valproatspiegels zu empfehlen.
Central Corneal Thickness can be Related to Diabetic Peripheral Neuropathy in Children with Type 1 Diabetes
Authors: Jeziorny Krzysztof , Fila Michal , Pyziak-Skupien Aleksandra , Kolodziej Magdalena , Waszczykowska Arleta , Zmyslowska-Polakowska Ewa , Szadkowska Agnieszka , Mlynarski Wojciech , Zmyslowska Agnieszka
Published: August 2019

Aims Diabetic eye disease with its various manifestations as well as diabetic neuropathy may occur in patients with type 1 diabetes (T1D) after several years of diabetes duration. Pachymetry is a promising method evaluating central corneal thickness (CCT) in diabetic patients. The aim of the study was to evaluate the CCT values in children with T1D and its relationship to neurophysiological markers of diabetic neuropathy.

Methods The study groups included 119 T1D children with average 5.3 years of diabetes duration and 38 age-matched controls. CCT index was measured with pachymeter in all subjects and in 19/119 of T1D patients the CCT values were referred to the ENG-EMG-SSR study results.

Results In T1D patients the higher CCT values were observed as compared to healthy controls (p=0.037). Correlations between CCT values and both distal latency of the motor fibers of the median nerve (R=0.51; p=0.044) and conduction velocity of this nerve (R=−0.55; p=0.027) were noted. A conduction velocity of the sensory fibers of sural nerve correlated negatively with CCT index (R=−0.50; p=0.045) in the T1D patients.

Conclusions CCT measurement may be helpful in the referral of the asymptomatic pediatric T1D patients to assess an early stage of diabetic neuropathy.
Bicyclic 1-Azafagomine Derivatives: Synthesis and Glycosidase Inhibitory Testing
Authors: Evangelista Tereza C. Santos , Lopéz Óscar , Sydnes Magne O. , Fernández-Bolaños José G. , Ferreira Sabrina Baptista , Lindbäck Emil
Published: August 2019

The synthesis of a series of 1-azafagomine derivatives that are tethered with five- and six-membered 1,2-annulated ring systems is described. These compounds were used in order to explore whether a hydrogen-bond acceptor group on the carbon atom corresponding to the glycosidic oxygen is able to interact with the catalytic acidic residue of β-glucosidase. The hydrogen-bond acceptor group was installed at various positions on the annulated ring system making it possible to study the effect of altering the position of this group.