bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing the limits of zeolite structural flexibility: ultrafast introduction of mesoporosity in zeolites
Authors: Peng Ce , Liu Zhendong , Yonezawa Yasuo , Linares Noemi , Yanaba Yutaka , Trujillo Carlos Alexander , Okubo Tatsuya , Matsumoto Taiji , García-Martínez Javier , Wakihara Toru
Published: December 2019

Ultrafast Surfactant-Templating (UST) achieved in just 1 minute indicates the high structural flexibility of zeolites for mesopore formation.
Photothermally assisted photocatalytic conversion of CO2–H2O into fuels over a WN–WO3 Z-scheme heterostructure
Authors: Liu Dali , Xu You , Sun Mengyao , Huang Yi , Yu Yifu , Zhang Bin
Published: December 2019

A direct Z-scheme WN–WO3 heterostructure is shown to be highly efficient for the photothermally assisted photocatalytic conversion of CO2–H2O into fuels without any sacrificial agents.
Probing catalytic surfaces by correlative scanning photoemission electron microscopy and atom probe tomography
Authors: Schweinar Kevin , Nicholls Rachel L. , Rajamathi Catherine R. , Zeller Patrick , Amati Matteo , Gregoratti Luca , Raabe Dierk , Greiner Mark , Gault Baptiste , Kasian Olga
Published: December 2019

Elucidating the atomic structure and chemistry of catalysts by correlative scanning photoemission electron microscopy and atom probe tomography.
High-performance alcohol electrooxidation on Pt3Sn–SnO2 nanocatalysts synthesized through the transformation of Pt–Sn nanoparticles
Authors: Wang Liang , Wu Wei , Lei Zhao , Zeng Tang , Tan Yangyang , Cheng Niancai , Sun Xueliang
Published: December 2019

An ordered Pt3Sn intermetallic, in which every Pt3Sn NP is in contact with one or more SnO2 NPs, was synthesized by the in situ transformation of Pt–Sn/NG.
Sequential post-polymerization modification of a pentafluorophenyl ester-containing homopolymer: a convenient route to effective pH-responsive nanocarriers for anticancer drugs
Authors: Pinyakit Yuwaporn , Palaga Tanapat , Kiatkamjornwong Suda , Hoven Voravee P.
Published: December 2019

Effective pH-responsive anticancer drug nanocarriers can be simply prepared through post-polymerization modification of a single pentafluorophenyl ester-containing polymer.
Photodynamic antitumor activity of Ru(ii) complexes of imidazo-phenanthroline conjugated hydroxybenzoic acid as tumor targeting photosensitizers
Authors: Liu Ze-Yu , Zhang Jin , Sun Yan-Mei , Zhu Chun-Fang , Lu Yan-Na , Wu Jian-Zhong , Li Jing , Liu Hai-Yang , Ye Yong
Published: December 2019

Two Ru(ii) polypyridyl complexes bearing hydroxybenzoic acid groups exhibited high phototoxicity toward tumor cells.
Polydopamine decorated ordered mesoporous carbon for efficient removal of bilirubin under albumin-rich conditions
Authors: Huang Shuyao , Zheng Jiating , Zhang Yimin , Zheng Juan , Zhuang Zena , Yang Qian , Wang Fuxin , Chen Guosheng , Huang Siming , Ouyang Gangfeng
Published: December 2019

Surface-imprinted polydopamine (PDA) on ordered mesoporous carbon (OMC) material was prepared for the efficient removal of bilirubin in albumin-rich conditions.
Genetically engineered haemoglobin wrapped covalently with human serum albumins as an artificial O2 carrier
Authors: Funaki Ryosuke , Okamoto Wataru , Endo Chihiro , Morita Yoshitsugu , Kihira Kiyohito , Komatsu Teruyuki
Published: December 2019

Recombinant human haemoglobin expressed in Pichia yeast was wrapped covalently with recombinant human serum albumins, yielding a core–shell structured rHbA(X)–rHSA3 cluster as an entirely synthetic O2 carrier used for a red blood cell substitute.
Stretching of fibroblast cells on micropatterned gelatin on silicone elastomer
Authors: Müller Stefan , Ueda Motoki , Isoshima Takashi , Ushida Takashi , Ito Yoshihiro
Published: December 2019

Micropatterned gelatin was formed on the silicone elastomer surface. The micropattern enabled cell alignment, regulation of the cell shape, and endowed the cells with resistance against mechanical stress.
Antibacterial activity of an NIR-induced Zn ion release film
Authors: Yang Tingting , Wang Donghui , Liu Xuanyong
Published: December 2019

The polydopamine containing Zn element as an ion carrier and heat-induced release film on GNRs-Ti surface enhanced the antibacterial properties.
Photo-/electro-luminescence enhancement of CsPbX3 (X = Cl, Br, or I) perovskite quantum dots via thiocyanate surface modification
Authors: Bao Zhen , Wang Weigao , Tsai Hsin-Yu , Wang Hung-Chia , Chen Shuming , Liu Ru-Shi
Published: December 2019

We use SCN ligands to modify the surface of blue, green, and red lead halide perovskite quantum dots to improve their luminescence properties and applied them to quantum dot light-emitting diodes.
Constructing a 3D interconnected Fe@graphitic carbon structure for a highly efficient microwave absorber
Authors: Zeng Sifan , Yao Yu , Feng Wanlin , Zhang Haibin , Peng Shuming
Published: December 2019

A 3D interconnected Fe@graphitic carbon structure shows outstanding microwave absorption properties owing to the synergetic effect of magnetic and dielectric losses.
Ergocalciferol improves endothelial vasodilatory and vasoconstrictor function in an in vivo model of mild uraemia
Authors: Dreyer Gavin , Kieswich Julius , Harwood Steven , Ahluwalia Amrita , Yaqoob Muhammad M.
Published: December 2019

Endothelial dysfunction and vitamin D deficiency are prevalent in patients with cardiovascular disease (CVD) and chronic kidney disease (CKD). Both are risk factors for cardiovascular events in patients with CKD. No studies have investigated the effect of nutritional forms of vitamin D on endothelial function in earlier stages of CKD, when vascular endothelium may be more amenable to this therapy. We studied the effect of ergocalciferol in a pre-clinical model of mild uraemia.

Male Wistar rats underwent either a 5/6th nephrectomy or sham surgery. Four weeks after the final stage of the surgery, these two groups were randomly allocated to placebo or an oral dose of 1000 iu of ergocalcfierol at day 7 and 2 pre sacrifice. Vascular responses to acetylcholine, Spermine NONOate and phenylephrine were determined in aortic rings. Blood pressure, calcium, phosphate and parathyroid hormone were measured in all groups.

Ergocalciferol significantly improved the endothelium-dependent responses to acetylcholine and overcame the blunting of the contractile response to phenylephrine seen in uraemic animals. Ergocalciferol improved the contractile response to potassium chloride in uraemic, but not sham animals. All effects occurred independently of changes to calcium, phosphate, parathyroid hormone and systolic blood pressure. There were no differences in endothelium-independent relaxation to Spermine NONOate.

In summary, in a model of mild uraemia, ergocalciferol improved vasodilator and vasoconstrictor tone independently of blood pressure and bone mineral parameters suggesting a direct effect of ergocalciferol on the endothelium.
miR-126a-3p induces proliferation, migration and invasion of trophoblast cells in pre-eclampsia-like rats by inhibiting A Disintegrin and Metalloprotease 9
Authors: Zhao Shenglong , Wang Jiandong , Cao Zheng , Gao Lei , Zheng Yuanyuan , Wang Jing , Liu Xiaowei
Published: December 2019

The present study aimed to investigate the underlying mechanism of miR-126a-3p in the proliferation, migration and invasion of trophoblast cells in pre-eclampsia-like rats by targeting A Disintegrin and Metalloprotease 9 (ADAM9). First, the interaction between miR-126a-3p and ADAM9 was confirmed via biochemical assays. Placental tissues and trophoblast cells were then obtained. RNA in situ hybridization was performed in order to detect miR-126a-3p expression in the placenta. Subsequently, a series of biological assays, including reverse transcription-quantitative PCR (RT-qPCR), Western blotting, MTT assay, apoptosis assay, cell cycle assay, wound healing assay and transwell assay were adopted in order to determine the cell proliferation, cell cycle distribution, apoptotic rate, and migration and invasion of trophoblast cells in each group. The results revealed that miR-126a-3p was down-regulated in the placenta of pre-eclampsia-like rats. In vivo experiments’ results indicated that miR-126a-3p could inhibit ADAM9 expression, and induce cyclin D1, Matrix metalloproteinase (MMP) 2 (MMP-2), MMP-9 expression. MTT, apoptosis and cell cycle assay results revealed that trophoblast cells transfected with miR-126a-3p mimic or si-ADAM9 exhibited higher proliferative activity and a lower apoptotic rate compared with the blank group (all P<0.05). The wound healing assay and transwell assay results confirmed that, compared with the blank group, the migration and invasion ability of trophoblast cells in the miR-126a-3p mimic group and small interfering RNA (siRNA)-ADAM9 group were significantly increased (all P<0.05). Conversely, miR-126a-3p inhibitor treatment revealed the opposite effect (all P<0.05). In conclusion, the present study demonstrated that miR-126a-3p could enhance proliferation, migration and invasion, but decrease the apoptosis rate of trophoblast cells in pre-eclampsia-like rats through targeting ADAM9.
Calibration method for attenuator piece used in calibrating a transmittance visibility meter
Authors: Liang Jing , Zhang Guoyu , Zhang Jian , Xu Da , Sun Gaofei
Published: December 2019

Aiming at the method of indoor calibration of a transmission visibility meter has not been established; a new calibration method by measuring the luminous transmittance of attenuator piece was established. Based on the high homogeneity stability lighting and the multi‐spectral transmittance analysis technique, a calibration system of the transmission visibility meter by measuring the luminous transmittance of the attenuator piece was designed. The experiment was designed by measuring the luminous transmittance with the range of 0.2–99.2% of a series of calibrated attenuators and the visibility in the range of 40 m to 20 km, then the luminous transmittance errors, the meteorological optical range (MOR) errors and their uncertainty were obtained. The result showed that the luminous transmission error was within ±0.18%, which satisfied the calibration requirement for transmission visibility meter transmittance; the MOR calibration error met the accuracy requirements of the International Civil Aviation Organisation for visibility measurement; this work will have guiding significance in establishing a calibration procedure for the transmission visibility meter.
Electrode channel optimisation method for steady‐state visual evoked potentials
Authors: Ma Kang , Wang Shuai , Zhang Shuailei , Sun Ying , Zheng DeZhi
Published: December 2019

This article proposes an electrode channel combination method for optimisation steady‐state visual evoked potentials (SSVEPs) towards a high‐performance brain‐computer interface (BCI). In SSVEP‐based BCIs, the channels which lie in the area near the occipital and parietal lobes are always selected to improve the classification accuracy. Although the electrode channels which are selected in occipital and parietal lobes have significantly improved the accuracy and reduced the calculating time of algorithm, the effect of electrode channel combination for each subject have not been systematically explored. This study conducts a comparison of BCI performance between two subjects in different electrode channel combinations. The results show significant difference between two subjects when selecting different electrode channel combinations using unsupervised target identification methods. The results suggest that different electrode channels should be selected for different subjects in SSVEP‐based BCIs.
Evaluation method of spindle performance degradation based on VMD and random forests
Authors: Wei Pangshi , Wang Hongjun
Published: December 2019

As one of the core components of the machine tool, the reliability of spindle is very important for improving machine tool quality. To effectively evaluate the performance degradation degree of the spindle, a method of degradation evaluation of the spindle performance based on variational mode decomposition (VMD) and random forests (RFs) was proposed. Firstly, VMD is used to process the current signal to obtain several modal components. Then, the time domain and frequency domain features of each modes component are calculated as eigenvalues. Finally, the RFs algorithm is used to classify the eigenvalues. The experimental results show that VMD can decompose the signal better and avoid the phenomenon of the modal mixture. The combination of VMD and RFs can accurately and effectively evaluate the performance degradation of the spindle.
Machine tool chatter test and analysis
Authors: Li Linxi , Zhong Jianlin , Wang Hongjun , Gao Yangjie
Published: December 2019

Machine chatter phenomenon has a great influence on the stability during the machining process of the machine tool. It has a great limitation on the machining efficiency of the machine tool and the machining accuracy of the product. The flutter of a machining center will appear when a certain machining center reaching a particular speed. The chatter will occur at a specific frequency. With the increase in the depth of cutting and the spindle speed, the value of chatter frequency will have complex changes; through the vibration test, it was confirmed that the two chatter frequencies are the natural frequencies of the product system and the spindle system, respectively. Improve the optimisation parameters and propose ways to suppress chatter.
Research on environmental monitoring and control technology based on intelligent Internet of Things perception
Authors: Lu Ting , Chen Xiaolong , Bai Wenhao
Published: December 2019

This study studies the technology of environmental monitoring and control in an intelligent Internet of Things (IoT) perception. To improve the issue of small coverage and low stability in the traditional environmental parameter testing, a new environment monitoring technique based on intelligent perception is proposed. The technical framework consists of three layers, intelligent perception layer, network communication layer, and application layer. The intelligent perception collects and transmits data to the application‐level server via the network communication layer for data analysis and diversified display. Based on this technique, we constructed a smart home environment monitoring and control system. The experimental test result shows that the system can accurately collect and process the data through the server and diversified displayed, which verifies the accuracy and reliability of this technique which is potential for further application.
Novel traction control of electric vehicle based on single wheel dynamics
Authors: Yang Ying , Liang Yingjing , Xu Guoqing , Zhang Jieming
Published: December 2019

It is hard for traction control to ensure the stability of vehicles because of the non‐linearity, uncertainty and parameters variation of vehicle dynamics. A novel traction control model is presented in this study to obtain the optimal traction performance by taking the advantage of fast torque response of electric vehicles (EVs) and dealing with driver operation properly. A new judgement unit is designed to combine the optimal slip ratio controller with driver operation, and the driver's input is kept when the slip ratio exceeds the reference value. Further, an engineering design method of the slip ratio controller is researched in terms of speed range and different work conditions. Two sets of controller parameters are designed since the vehicle time constant varies with wheel speed. The possibility of taking fix controller parameters value in one speed range is analysed and verified. Moreover, the stability of system and the influence of sampling frequency on system are analysed. Finally, the validity of the proposed control methodology is fully verified with simulation and experiments on the tire–road simulation test bench which adopts the asynchronous motor mechanical properties to simulate tire–road characteristics.
Anti‐slip control based on optimal slip ratio for heavy‐haul locomotives
Authors: He Jing , Zuo Xintian , Zhang Changfan , Mao Songan , He Yunguo
Published: December 2019

To solve the problem of wheelset slip and effectively exert locomotive traction, a protection method of anti‐slip control with integral sliding mode based on optimal slip ratio is proposed. First, a dynamic model of heavy‐haul locomotives is established and a sliding mode observer is designed to observe the real‐time adhesion coefficients of heavy‐haul locomotives. An extremum seeking algorithm with sliding mode is used to monitor and search the optimal region of slip ratio. Then, a PID compound control is combined to weaken oscillations in the sliding mode extremum seeking. Finally, an integral sliding mode controller with new reaching law is designed to ensure the slip ratio of locomotives running on different rail surfaces are at optimal values, which maximise the utilisation of adhesion between wheels and rails. Simulation results also verify the feasibility and effectiveness of the integral sliding mode variable structure control method based on optimal slip ratio in the anti‐slip traction system of vehicles.
New line‐loss management technology of distribution area based on electricity information collection system
Authors: Song Tengfei , Wang Qing , Zhang Senlin , Mu Xiao , Dai Yanjie , Sun Fenglin
Published: December 2019

With the application of electricity information acquisition system and the gradual improvement of related functions, the management on line‐loss in intelligent distribution area operated by power supply enterprises has made great progress. However, due to the influence of the subjective and objective factors, the line‐loss management has not reached the expected target, which directly affects the economic benefit of power supply enterprises. This article mainly introduces a new management technique of line‐loss in intelligent distribution area based on electricity information acquisition system. The abnormal loss of electric energy in intelligent distribution area caused by the current with unbalanced three‐phase and the meter connection mode is mitigated.
Efficiency analysis of coupled resonant radio energy transmissions
Authors: Zhang Ji , Tian Hong , Liu Hua , Sun Yuan , Kong Xiangsong , Liu Cheng
Published: December 2019

In order to improve the transmission efficiency of magnetic coupling resonance for wireless transmission technology, the dual coil wireless transmission system was designed and simulated based on ANSYS. Influencing factors of transmission efficiency include coil turns, material properties, frequency characteristics, and maximum transmission distance. A relevant experimental circuit is designed to verify the correctness of the theoretical analysis and provide an effective reference to improve the efficiency of radio energy transmission. Through the analysis of past improvement schemes, the performance of wireless transmission equipment is optimised based on electromagnetic field simulation and the frequency‐splitting phenomenon is verified.
Low‐cost and flexible film‐based digital microfluidic devices
Authors: Fan Yiqiang , Kong Xiaopeng , Chai Dongping , Wei Bin , Zhang Yajun
Published: December 2019

This work proposed a low‐cost and rapid fabrication approach for flexible thin film‐based digital microfluidics. In this approach, the carbon electrodes were screen‐printed on the surface of a polyester film using carbon resistive ink. Then, a layer of polyethylene was applied to seal the polyester film with electrodes. Finally, a surface treatment was conducted to enhance the hydrophobicity. Compared with the conventional fabrication approaches for digital microfluidic devices using metal electrodes deposition on glass/silicon substrate, the proposed fabrication technique for polymer‐based digital microfluidic device is simple, low‐cost, flexible, and without the requirement of sophisticated photolithography procedure, metal deposition instruments and cleanroom environment. The proposed polymer‐based digital microfluidic device has a total thickness <200 μm. The whole device is transparent, flexible and bendable. A series of tests were also conducted for the manipulation of water droplets using electrowetting on the fabricated digital microfluidic devices. The proposed fabrication technique for flexible film‐based digital microfluidics could have wide potential point‐of‐care applications in biological and medical filed.
Fourier series for eclipses on exoplanet binaries
Authors: Visser P. M. , Mol M. A.
Published: December 2019

Context. A double planet system or planet binary undergoes eclipses that modify the reflective light curve. In the time domain, the eclipse events are fast and weak. This would make their signal difficult to find and recognize in the phase light curve, even for small inclinations when eclipses happen frequently. However, due to the quasiperiodic nature of the phenomenon, the Fourier transform of the direct reflection signal consists of a double sum of sharp peaks. These peaks can be resolved for large close binaries and sufficiently long observation times with a star coronagraph.

Aims. Eclipses modulate the phase curve, having an orbital period 2π∕ω, with a contribution from the relative motion in the binary plane of a period 2π∕Ω. This leads to a spectral structure with basis frequencies ω and Ω. We aim to characterize these spectra.

Methods. We studied the regime of short eclipses that occur when the planet radii are small compared to the planet separation. We derived formulas for the peak amplitudes applicable to homogeneous (Lambertian) planet binaries in circular orbit with small inclination.

Results. The effects of an eclipse and of double reflection appear as first- and second-order contributions (in planet radius over separation) in the reflection signal, respectively. Small peaks appear as observable side bands in the spectrum. Identical structures around mΩ are characteristic of short-duration eclipses. Deceasing side bands could indicate double reflection between companions.

Conclusions. Fourier analysis of the light curve of non-transiting planets can be used to find planets and their moons. Difficulties in interpreting the structures arise for small planet separation and when there are several moons in mean-motion resonance.
Jupiter formed as a pebble pile around the N2 ice line
Authors: Bosman A. D. , Cridland A. J. , Miguel Y.
Published: December 2019

Context. The region around the H2O ice line, due to its higher surface density, seems to be the ideal location to form planets. The core of Jupiter, as well as the cores of close-in gas giants are therefore thought to form in this region of the disk. Nevertheless, constraining the formation location of individual planets has proven to be difficult.

Aims. We aim to use the nitrogen abundance in Jupiter, which is around four times solar, in combination with Juno constraints on the total mass of heavy elements in Jupiter to narrow down its formation scenario.

Methods. Different pathways of enrichment of the atmosphere of Jupiter are considered, such as the accretion of enriched gas, pebbles, and planetesimals, and their implications for the oxygen abundance of Jupiter are discussed.

Results. The super-solar nitrogen abundance in Jupiter necessitates the accretion of extra N2 from the proto-solar nebula. The only location of the disk where this can happen is outside or just inside the N2 ice line. These constraints favor a pebble accretion origin of Jupiter, from the perspective of composition and planet formation. We predict that Jupiter’s oxygen abundance is between 3.6 and 4.5 times solar.
Time discretization of an initial value problem for a simultaneous abstract evolution equation applying to parabolic-hyperbolic phase-field systems
Authors: Kurima Shunsuke
Published: December 2019

This article deals with a simultaneous abstract evolution equation. This includes a parabolic-hyperbolic phase-field system as an example which consists of a parabolic equation for the relative temperature coupled with a semilinear damped wave equation for the order parameter (see e.g., Grasselli and Pata [Adv. Math. Sci. Appl. 13 (2003) 443–459, Comm. Pure Appl. Anal. 3 (2004) 849–881], Grasselli et al. [Comm. Pure Appl. Anal. 5 (2006) 827–838], Wu et al. [Math. Models Methods Appl. Sci. 17 (2007) 125–153, J. Math. Anal. Appl. 329 (2007) 948–976]). On the other hand, a time discretization of an initial value problem for an abstract evolution equation has been studied (see e.g., Colli and Favini [Int. J. Math. Math. Sci. 19 (1996) 481–494]) and Schimperna [J. Differ. Equ. 164 (2000) 395–430] has established existence of solutions to an abstract problem applying to a nonlinear phase-field system of Caginalp type on a bounded domain by employing a time discretization scheme. In this paper we focus on a time discretization of a simultaneous abstract evolution equation applying to parabolic-hyperbolic phase-field systems. Moreover, we can establish an error estimate for the difference between continuous and discrete solutions.
Challenges of additive manufacturing in production systems
Authors: Luft Angela , Gebhardt Andreas , Balc Nicolae
Published: December 2019

Additive Manufacturing (AM) has become indispensable in the context of digitalization and Industry 4.0 and is said to be a mega trend of the 21st century. The technology offers immense opportunities to revolutionize the production of parts and components in all industries. Despite of the outstanding technical possibilities, the industry-wide adaptation rate is low. The current approach of looking at AM from a mostly technological view is a major reason for this. The challenge is to efficiently integrate 3D printing and other additive processes into existing manufacturing processes and systems. AM must be perceived as a multidimensional topic and viewed from different perspectives, two of which are the AM technology and the planning and management of production systems. These two perspectives have to be addressed simultaneously and cross-linked. In order to use AM to tackle some of the most challenging problems in modern manufacturing systems like increasing variant diversity, shorter product lifecycles, the demand for digitized processes and cyber-physical systems, it is necessary to develop interdisciplinary approaches and solutions, because none of the disciplines can reach the necessary performance and cost-efficiency alone.
Basic research of the consideration of additive manufactured lattice structures under thermoand fluid dynamic loads
Authors: Abbas Karim , Thurn Laura , Kessler Julia , Eichler Fabian
Published: December 2019

This scientific research deals with lattice structures manufactured with laser powder bed fusion. Laser powder bed fusion is part of additive manufacturing. The so called layered construction is an increasingly used innovative manufacturing process that can be used to realize new design possibilities. Lightweight structures or bionic structures play a key role here. The focus of this work is on periodic lattice structures. In addition to saving resources and reducing the weight of components, lattice structures have particularly pronounced mechanical properties. However, little is known about their thermo- and fluid-dynamic properties. This work describes the first influencing factors of lattice structures ina thermo- and fluid-dynamic context using a case study. The aim of this paper is to evaluate important design and simulation criteria of lattice structures. Different lattice structures are considered, whose strut geometry is varied. The case study is carried out using a heat exchanger. While classical heat exchangers have lamellar structures, the substitution of these by lattice structures is evaluated. Thiswork represents a first consideration of the most important parameters and gives an overview of the most important core points.
Comparison study between two types of nozzles for a turbocharger balancing machine using ANSYS software
Authors: Becze Sigismund , Vuscan Gheorghe Ioan
Published: December 2019

Turbocharger balancing machines require a specific tooling for spinning the center housing rotating assembly, in order to balance it dynamically. The tooling requires a nozzle to guide the air to the blades of the turbine wheel in order to spin it. Depending on the type of nozzle chosen, the maximum rotational speed achieved and the acceleration curve can be different. In today?s market there is anincreasing demand for a higher turbocharger speed, generally driven by the demand for engine downsizing and for a higher performance. Due to that, turbochargers need to be better balanced, thus requiring a wider measurement range of the unbalanced in order to see how the part performs in all its working range. Consequently, the nozzles used by turbocharger balancing machines need to be verified at a higher speed limit.
The influence of the cutting parameters on the pullout resistance of the M8 thread processed by tapping into the SikaBlock M960 material
Authors: Ravai-Nagy Sandor
Published: December 2019

Given that polyurethane materials are used more and more often in the assembly line of light alloy parts or thin steel sheets, it is necessary to determine the most favourable cutting parameters. Based on the studies in the field of threads, I found that the cutting parameters have an influence on the internal tapped thread pullout resistance. In the experiments, I studied the M8 thread manufactured by tapping into the
SikaBlock@M960 material.
Study on milling strategies influence on the quality characteristics in case of composite material
Authors: Ceclan Vasile , Popan Alexandru , Grozav Sorin , Popan Alina
Published: December 2019

Composite materials are widely used today. In this paper we want to conduct a research on the strategy of milling processing of composite materials. A CAD model is required to perform this research. This 3D model must have different areas where the difference between the climb strategy and the conventional strategy can be observed. Special tools and cutting parameters corresponding to the material to be machined are required for this 3D model.
Research regarding tactile scanning versus optical scanning
Authors: Bulgaru Marius , Bocăneț Vlad , Muntean Mircea
Published: December 2019

In today’s fast-moving world, the manufacturing industry must keep up with evolving trends. One such trend that has greatly impacted the manufacturing industry is called Industry 4.0 and is regarded as the fourth industrial revolution. In this revolution one important aspect is that of quality. This paper makes a comparative study between tactile and optical measuring machines in the context of Industry 4.0. As the manufacturing industry must be more flexible and solve problems in a timelier manner, it is important to identify the right technologies appropriate for quality control.
Modular fastening system and tool–holder working unit for incremental forming
Authors: Tera Melania , Gîrjob Claudia–Emilia , Biriș Cristina–Maria , Crenganiș Mihai
Published: December 2019

Incremental forming can be usually unfolded either on CNC milling machine–tools or serial industrial robots. The approach proposed in this paper tackles the problem of designing a modular fastening system, which can be adapted for both above mentioned technological equipment. The fastening system of the sheet–metal workpiece is composed of a fixing plate and a retaining plate. The fixing and retaining plates will be made up of different individual elements, which can be easily repositioned to obtain different sizes of the part. Moreover, the fastening system has to be able to be positioned either horizontally (to be fitted on CNC milling machines) or vertically (to be fitted on industrial robots. The paper also presents the design of a tool–holder working unit which will be fitted on KUKA KR 210 industrial robot. The working unit will be mounted as end–effector of the robot and will bear the punch, driving it on the processing toolpaths.
Drillstring Failure: Analytical and Experimental Approach
Authors: Hassan Edris , Abdo Jamil , Kwak Jan , Al Shabibi Abdullah
Published: December 2019

Drilling is one of the costliest activities in oil and gas industry due to the complexity of interactions with downhole rock formation. Under such conditions, the uncertainty of drillstring behaviour increase and hence it becomes difficult to predict the causes, occurrences, and types of failures. Lateral and torsional vibrations often cause failure of Bottom Hole Assembly (BHA), drillstring failure, drill bit and wall borehole damages. In this work, a model is presented to determine the impact of lateral and torsional vibrations on a drillstring during the drilling operation. The model aims to mimic real drillstring behaviour inside a wellbore with regards to its dynamic movements due to multiple real situations such as eccentricity of collars, drill pipe sections, and stick-slip phenomena occurring due to the interaction of the bit and the drillstring with the well formation. The work aims to develop a basis for determining critical operating speeds and design parameters to provide safe drilling procedures and reduce drill string fatigue failure. Lagrangian approach is used in this study to attain drillstring lateral and torsional vibration coupling equations. The nonlinear equations are solved numerically to obtain the response of the system. In this work, we also present a brief description of an in-house constructed experimental setup. The setup has the capability to imitate the downhole lateral and torsional vibration modes. Parameters from the experimental investigations are incorporated for validation of the mathematical models and for prediction of the drillstring fatigue life. Such investigations are essential for oil and gas industries as they provide solutions and recommendations about operational speed, lateral and torsional amplitudes measurements and corrections, and the conditions for avoiding occurrence of natural frequencies of the system.
Axial-torsional fatigue and cyclic deformation of 304L stainless steel at room temperature
Authors: Bemfica Cainã , Mamiya Edgar , Castro Fábio
Published: December 2019

This work investigates the axial-torsional fatigue and cyclic deformation behaviour of 304L stainless steel at room temperature. Four fully reversed strain-controlled loading paths (axial, torsional, proportional axial-torsional, and 90º out-of-phase axial-torsional) and a fully-reversed shear strain-controlled with static axial stress loading were investigated. For axial, torsional, torsional with static stress and few proportional experiments, an initial cyclic softening was followed by secondary hardening related to martensitic transformation. Secondary hardening was not observed for non-proportional loading nor for some proportional experiments. The influence of the non-stabilized cyclic deformation behaviour on the fatigue life estimates of two multiaxial critical plane fatigue models (Smith–Watson–Topper and Fatemi–Socie) was investigated. Life estimates based on the stress-strain hysteresis loops corresponding to the maximum softening and to the half-life were similar for the two models.
Influence of hard and soft inclusions inside a ferritic matrix
Authors: Fincato Riccardo , Tsutsumi Seiichiro , Sakai Tatsuo , Terada Kenjiro
Published: December 2019

In the case of an interior fracture mode in fatigue, material impurities play a fundamental role in the generation and the propagation of cracks. In general, the presence of hard or soft inclusions, voids, materials imperfections, etc., alter the local stress state in the matrix generating the accumulation of plastic deformations which lead to the crack formation. In terms of inclusions, high strength steels are often characterized by the presence of aluminum oxides Al2O3 or Manganese sulfide MnS. The experimental works reported by several authors pointed out that the critical location for the crack nucleation is, often, at the edge of the inclusion and it subsequently propagates on a plane orthogonal to the loading direction. In a previous work, the authors investigated the stress distribution around a spherical inclusion inside a ferritic matrix, pointing out the role of the material anisotropy and the different crystallographic orientation of the matrix. However, the investigations dealt with simple loading conditions and linear elasticity. The present paper aims to extend the field of investigations to the elasto-plastic domain, focusing the attention on the role of the crystallographic orientation and comparing the results with the previous study.
A three-dimensional elastoplastic analysis of mixed-modeKI/KIIaround the crack front
Authors: Nazaré Marques Luiz Fernando , Pinho de Castro Jaime Tupiassú , Martha Luiz Fernando , Meggiolaro Marco Antonio
Published: December 2019

Engineering problems that involve fatigue crack growth and fracture frequently can be studied by taking into account only mode-I features. However, many important problems that involve combined mode I and II loadings cannot be properly analyzed by a pure mode-I approach, which in particular may not be sufficient to estimate fracture toughness for practical purposes in such cases. Such mixed-mode problems involve crack orientation and/or load conditions that lead to combined local Stress Intensity Factors (SIFs)KI/KIIaround the crack front. Using multiaxial crack tip condition characterized by the crack inclination angleβin a mixed-modeKI/KIImodified single edge tension SE(T) specimen, such mixed-mode effects on plastic zone shapes, volumes and plastic workUPLare taken into account to evaluate problems that involve fatigue and fracture.
Mixed mode I/II/III fracture assessment of PMMA using a new test fixture
Authors: Razavi Seyed Mohammad Javad , Lie Hokstad Haakon , Berto Filippo
Published: December 2019

Brittle and quasi-brittle fracture has been recognized as the main failure mechanism in various structural components. Due to complexity of the components’ geometry and loading condition, a combination of tensile, in-plane shear and out of plane shear loading results in final fracture of cracked components. Hence, it is important to evaluate the fracture behaviour of different materials under a mixed mode loading condition which is close to the real-life loading of the structural parts. In this paper, a new loading device for general mixed mode I/II/III fracture tests is designed and recommended. Finite element analyses are performed to study the fracture parameters of the test specimens under different mixed mode loading conditions. According to the numerical results, the designed loading fixture can generate a wide varieties of mode mixities from pure tensile mode to pure in-plane and out of plane shear modes. Fracture tests were performed on pre-cracked specimens made of polymethyl methacrylate (PMMA) to check the accuracy of the proposed fixture. The proposed fixture was proved to be applicable for general mixed mode fracture evaluation of brittle materials.
Effect of phase angle on the cyclic behavior of AISI 410 alloy
Authors: Adinoyi Muhammed J. , Merah Nesar , Albinmousa Jafar
Published: December 2019

Multiaxial strain-controlled fatigue tests were conducted on AISI 410 according to ASTM 2207-E08 [1] under proportional (phase angle, θ = 90°) and non-proportional (phase angle, θ = 90º) loadings. Axial strain amplitudes in the range of 0.2%-0.35% are paired with shear strain amplitudes in the range of 0.25%-0.5%. Comparison was made between the hysteresis loops under both loading modes. It was found that peak stresses are higher under nonproportional loading, but with less plastic deformation. Additional stress hardening is exhibited by the alloy, resulting in the tip of the hysteresis loop under nonproportional loading to be rounded. Stress evolution with the number of fatigue cycles, mainly show cyclic stress softening except in axial stress under nonproportional loading where stress stabilization is largely the case after initial hardening. Fatigue life under nonproportional loading is generally lower than that of proportional loading.
The effect of mean axial and torsional stresses on the fatigue strength of 34CrNiMo6 high strength steel
Authors: Pallarés-Santasmartas Luis , Albizuri Joseba , Leguinagoicoa Nelson , Saintier Nicolas , Merzeau Jonathan
Published: December 2019

The present study consists of a theoretical, experimental and fractographic investigation of the effect of superimposed static axial and shear stresses on the high cycle fatigue behavior of a 34CrNiMo6 high strength steel in quenched and tempered condition (UTS = 1210 MPa), commonly employed in highly stressed mechanical components. The Haigh diagrams for the axial and torsional cases under different values of mean stress were obtained. In both cases, experimental results showed that increasing the mean stress gradually reduces the stress amplitude that the material can withstand without failure. The results of the present tests are compared with the theoretical predictions from Findley, based on the maximum damage critical plane; and the methods of Marin and Froustey, which are energetic based criterions. Froustey’s method shows the best agreement with experimental results for torsional fatigue with mean shear stresses, showing a non-conservative behaviour for the axial fatigue loading case. Macro-analyses and micro-analyses of specimen fracture appearance were conducted in order to obtain the fracture characteristics for different mean shear stress values under torsion fatigue loading.
A continuum based macroscopic unified low-and high cycle fatigue model
Authors: Frondelius Tero , Holopainen Sami , Kouhia Reijo , Ottosen Niels Saabye , Ristinmaa Matti , Vaara Joona
Published: December 2019

In this work, an extension of a previously developed continuum based high-cycle fatigue model is enhanced to also capture the low-cycle fatigue regime, where significant plastic deformation of the bulk material takes place. Coupling of the LCFand HCF-models is due to the damage evolution equation. The high-cycle part of the model is based on the concepts of a moving endurance surface in the stress space with an associated evolving isotropic damage variable. Damage evolution in the low-cycle part is determined via plastic deformations and endurance function. For the plastic behaviour a non-linear isotropic and kinematic hardening J2-plasticity model is adopted. Within this unified approach, there is no need for heuristic cycle-counting approaches since the model is formulated by means of evolution equations, i.e. incremental relations, and not changes per cycle. Moreover, the model is inherently multiaxial and treats the uniaxial and multiaxial stress histories in the same manner. Calibration of the model parameters is discussed and results from some test cases are shown.
A Novel Engineering Education Innovation Pattern with Design Ideas and Robot Maker Practice
Authors: Zhu Aibin , Shen Huang , Shen Zhitao , Tu Yao , Song Jiyuan
Published: December 2019

Traditional engineering education of innovative thinking mainly focused on knowledge imparting, thinking and learning, but it weakens the cultivation of students' practical ability. In this paper, a new pattern of innovative thinking engineering education is proposed, which combines abstract design innovation with specific robot maker practice. By offering general course for all professional students, it teaches the theory, methods and tools of systematic innovative thinking, and cultivates students' system design methods and innovative thinking. Taking the design and production process of robots as the object and content of practical teaching, the traditional teaching pattern centered on teachers, classrooms and textbooks is changed, teachers' reflection on teaching is promoted, so that it can be truly changedfrom a lecturer to an inspirator of learning, at the same time, teaching flexibility is increased, and students' highlevel thinking and practical abilities are improved. Classroom statistics show that 92.14% of the students think that their innovative thinking ability has been improved, and 90.71% of the students consider that their practical ability has been enhanced. It shows that the engineering education innovation pattern with design ideas and robot maker practice can inspire students' innovative thinking, while improving students' robotic practical ability.
Axiomatic Design of an automatic card dealing robot
Authors: Sigmarsson Anton Björn , Helgason Ágúst Benóný , Albertsson Óskar Ágúst , Foley Joseph Timothy
Published: December 2019

When you’re playing card games with friends, a problem often occurs, at some point, no one wants to be the dealer. We propose an automatic card dealing robot. There are a few products on the market today that are expensive or missing critical functionality to fulfill the role of a card dealer. Our product will be more affordable and more portable than existing systems. The robot can be used in a variety of applications, for education, for the physically challenged, and of course for fun. The goal was to build a robot using Axiomatic Design methodology, with faster card dealing capabilities than a human.
Concept Design of a Digital Shop Floor Information System for Assembly Operators in Machine Industry
Authors: Tauber Matthias , Gallmetzer Andreas , Rauch Erwin , Brown Christopher A. , Matt Dominik T.
Published: December 2019

Industry 4.0 and digitization are currently changing shop floor management in production. Especially in the production of highly customized and individual products, digitization offers many opportunities for more efficient processes. Providing the right information in the right time at the right place can help to reduce lead time as well as production costs. This paper shows the use of Axiomatic Design to develop a conceptual design for an innovative and digital shop floor information system for supporting assembly operators in machine industry in their daily work. The research is based on a real industrial case study with a medium sized manufacturer of customized machines. Needs from practice were collected through workshops with the industry partner and were translated into functional requirements. These functional requirements were derived with an Axiomatic Design decomposition to design solutions. The results of the AD analysis were used as a basis for the concept design of an operator information system in the company.
Experimental study on bending behaviour of aluminium-copper clad sheets in V-bending process
Authors: Srinivasan R. , Karthik Raja G.
Published: December 2019

The bimetallic sheets are used in the industrial sheet metal products to meet the demands of multi-functionality. The bending behaviour of bimetallic sheet is contributed by individual layers of the sheet and it is entirely different from the monolithic material. In this study, V-bending experiments are carried out to understand the springback, bend force and thickness change of Al-Cu clad sheets. The effect of different parameters such as sheet thickness, sheet setting condition, die angle, die opening and punch radius have been investigated. The results indicated that springback is more for smaller die angle, wider die opening and larger punch radius. Increase in die angle, increase in die opening or decrease in punch radius decreases the bend force. The clad sheet thickens at Al/Cu setting condition whereas it thins at Cu/Al setting condition. This thinning or thickening of the sheet influences the springback and bend force.
Mathematical model of steady flow in a helium loop
Authors: Világi František , Knížat Branislav , Mlkvik Marek , Urban František , Olšiak Róbert , Mlynár Peter
Published: December 2019

The article describes the application of a mathematical model to a natural circulation loop. A set of measurements were conducted at the experimental facility. The pressure and velocity relations were observed during the steady flow of helium. The main goal was to create a numerical model of flow capable of determining the velocity of flowing medium. The model describes the flow of highly compressed gaseous medium with variable density in direct pipelines with local resistances. At the current state, the temperature values along the loop are taken as input to the model. The article also includes the evaluation of local resistances in DHR and GFR, which significantly affects the resulting accuracy. The results from a numerical model are compared with experiments.