Journal of Engineering The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Advantageous Reservoir Characterization Technology in Extra Low Permeability Oil Reservoirs Thu, 12 Oct 2017 00:00:00 +0000 This paper took extra low permeability reservoirs in Dagang Liujianfang Oilfield as an example and analyzed different types of microscopic pore structures by SEM, casting thin sections fluorescence microscope, and so on. With adoption of rate-controlled mercury penetration, NMR, and some other advanced techniques, based on evaluation parameters, namely, throat radius, volume percentage of mobile fluid, start-up pressure gradient, and clay content, the classification and assessment method of extra low permeability reservoirs was improved and the parameter boundaries of the advantageous reservoirs were established. The physical properties of reservoirs with different depth are different. Clay mineral variation range is 7.0%, and throat radius variation range is 1.81 μm, and start pressure gradient range is 0.23 MPa/m, and movable fluid percentage change range is 17.4%. The class IV reservoirs account for 9.56%, class II reservoirs account for 12.16%, and class III reservoirs account for 78.29%. According to the comparison of different development methods, class II reservoir is most suitable for waterflooding development, and class IV reservoir is most suitable for gas injection development. Taking into account the gas injection in the upper section of the reservoir, the next section of water injection development will achieve the best results. Yutian Luo, Zhengming Yang, Lixin Meng, and Shutie Li Copyright © 2017 Yutian Luo et al. All rights reserved. Hierarchical Feature Extraction Assisted with Visual Saliency for Image Quality Assessment Tue, 03 Oct 2017 08:23:19 +0000 Image quality assessment (IQA) is desired to evaluate the perceptual quality of an image in a manner consistent with subjective rating. Considering the characteristics of hierarchical visual cortex, a novel full reference IQA method is proposed in this paper. Quality-aware features that human visual system is sensitive to are extracted to describe image quality comprehensively. Concretely, log Gabor filters and local tetra patterns are employed to capture spatial frequency and local texture features, which are attractive to the primary and secondary visual cortex, respectively. Moreover, images are enhanced before feature extraction with the assistance of visual saliency maps since visual attention affects human evaluation of image quality. The similarities between the features extracted from distorted image and corresponding reference images are synthesized and mapped into an objective quality score by support vector regression. Experiments conducted on four public IQA databases show that the proposed method outperforms other state-of-the-art methods in terms of both accuracy and robustness; that is, it is highly consistent with subjective evaluation and is robust across different databases. Ruizhe Deng, Yang Zhao, and Yong Ding Copyright © 2017 Ruizhe Deng et al. All rights reserved. Experimental Study on RFID Antenna Reading Areas in a Tunnel System Wed, 30 Aug 2017 07:55:09 +0000 We study optimized antenna reading area mappings for a radiofrequency identification- (RFID-) based access monitoring system, used in an underground nuclear waste storage facility. We shortly introduce the access monitoring system developed for the ONKALO tunnel in Finland and describe the antenna mounting points as well as the research area. Finally, we study the measurement results of the antenna reading areas and factors that affect the reading area size. Based on our results, in addition to antenna location and direction, absorption to obstacles, reflections, diffraction, scattering, and refraction affect the antenna reading area. Kai Kordelin, Jaana Kordelin, Markku Johansson, Johanna Virkki, Leena Ukkonen, and Lauri Sydänheimo Copyright © 2017 Kai Kordelin et al. All rights reserved. A Novel Electric Bicycle Battery Monitoring System Based on Android Client Tue, 08 Aug 2017 00:00:00 +0000 The battery monitoring system (BMS) plays a crucial role in maintaining the safe operation of the lithium battery electric bicycle and prolonging the life of the battery pack. This paper designed a set of new battery monitoring systems based on the Android system and ARM single-chip microcomputer to enable direct management of the lithium battery pack and convenient monitoring of the state of the battery pack. The BMS realizes the goal of monitoring the voltage, current, and ambient temperature of lithium batteries, estimating the state of charge (SOC) and state of health (SOH), protecting the battery from abuse during charging or discharging, and ensuring the consistency of the batteries by integrating the passive equalization circuit. The BMS was proven effective and feasible through several tests, including charging/discharging, estimation accuracy, and communication tests. The results indicated that the BMS could be used in the design and application of the electric bicycle. Chuanxue Song, Yulong Shao, Shixin Song, Silun Peng, and Feng Xiao Copyright © 2017 Chuanxue Song et al. All rights reserved. Analysis and Design of an Energy Efficient Differential Coherent Chaos Based System in Additive White Gaussian Noise Environment Thu, 03 Aug 2017 00:00:00 +0000 A new differential coherent chaos based scheme is proposed and named as Differential Chaos ON-OFF Keying (DCOOK). The proposed scheme provides reduction in bit energy and better bit error performance at large spreading factor. This is achieved by presenting each transmitted bit by either identical segment or no transmission within same bit duration. The receiver performs simple correlation between the received signal and its delayed version to determine the transmitted information utilizing the low correlation between the noise signals. The bit error rate (BER) performance of the proposed scheme is evaluated analytically using Gaussian Approximation (GA) method and compared with the simulation results. The results show excellent agreement between the derived expression and simulation. Moreover, the BER of DCOOK scheme is compared with the standard chaos systems: Chaos ON-OFF Keying (COOK), Differential Chaos Shift Keying (DCSK), and Correlation Delay Shift Keying (CDSK). The comparison results show that DCOOK scheme can always achieve superior performance compared to COOK and CDSK schemes and even exceeds the performance of DCSK scheme at typical spreading factor values. Nizar Al Bassam and Oday D. Jerew Copyright © 2017 Nizar Al Bassam and Oday D. Jerew. All rights reserved. The Circular Economy of E-Waste in the Netherlands: Optimizing Material Recycling and Energy Recovery Mon, 31 Jul 2017 00:00:00 +0000 In the Netherlands, waste electric and electronic equipment (e-waste) is an important point for discussion on the circular economy agenda. This paper shows the Dutch example of how “waste” can be turned into a resource, and the climate change benefits from appropriate collection and recycling. It describes the avoided emissions of CO2-equivalents due to e-waste recycling and appropriate removal and destruction of (H)CFCs contained in cooling and freezing appliances. Six different e-waste categories were included, and the results of 2016 were compared to previous years (2009–2015). In 2016, 110,000 tonnes of e-waste were collected. 80% of this was recycled to useful materials. Additionally, it resulted in 17% energy recovery. That year, the recycling of e-waste and the removal of (H)CFKs resulted in approximately 416,000 tonnes of avoided emissions of CO2-equivalents. Although the phasing out of cooling and freezing appliances with (H)CFKs led to a general decrease in the quantity of avoided CO2 emissions over time, removal of (H)CFKs still explained most of the avoided CO2 emissions. Material recycling appeared particularly beneficial for cooling and freezing appliances and small and large household appliances. The paper ends with reasons to further close the loop and ways forward to do so. Laura Golsteijn and Elsa Valencia Martinez Copyright © 2017 Laura Golsteijn and Elsa Valencia Martinez. All rights reserved. A Condensed Introduction to the Doubly Fed Induction Generator Wind Energy Conversion Systems Thu, 22 Jun 2017 00:00:00 +0000 The increase in wind power penetration, at 456 GW as of June 2016, has resulted in more stringent grid codes which specify that the wind energy conversion systems (WECS) must remain connected to the system during and after a grid fault and, furthermore, must offer grid support by providing reactive currents. The doubly fed induction generator (DFIG) WECS is a well-proven technology, having been in use in wind power generation for many years and having a large world market share due to its many merits. Newer technologies such as the direct drive gearless permanent magnet synchronous generator have come up to challenge its market share, but the large number of installed machines ensures that it remains of interest in the wind industry. This paper presents a concise introduction of the DFIG WECS covering its construction, operation, merits, demerits, modelling, control types, levels and strategies, faults and their proposed solutions, and, finally, simulation. Qualities for the optimal control strategy are then proposed. The paper is intended to cover major issues related to the DFIG WECS that are a must for an overview of the system and hence serve as an introduction especially for new entrants into this area of study. Julius Mwaniki, Hui Lin, and Zhiyong Dai Copyright © 2017 Julius Mwaniki et al. All rights reserved. A Concise Presentation of Doubly Fed Induction Generator Wind Energy Conversion Systems Challenges and Solutions Tue, 20 Jun 2017 00:00:00 +0000 There is increased worldwide wind power generation, a large percentage of which is grid connected. The doubly fed induction generator (DFIG) wind energy conversion system (WECS) has many merits and, as a result, large numbers have been installed to date. The DFIG WECS operation, under both steady state and fault conditions, is of great interest since it impacts on grid performance. This review paper presents a condensed look at the various applied solutions to the challenges of the DFIG WECS including maximum power point tracking, common mode voltages, subsynchronous resonance, losses, modulation, power quality, and faults both internal and from the grid. It also looks at approaches used to meet the increasingly stringent grid codes requirements for the DFIG WECS to not only ride through faults but also provide voltage support. These are aspects of the DFIG WECS that are critical for system operators and prospective investors and can also serve as an introduction for new entrants into this area of study. Julius Mwaniki, Hui Lin, and Zhiyong Dai Copyright © 2017 Julius Mwaniki et al. All rights reserved. Membrane Fouling and Chemical Cleaning in Three Full-Scale Reverse Osmosis Plants Producing Demineralized Water Thu, 15 Jun 2017 10:46:34 +0000 Membrane fouling and cleaning were studied in three reverse osmosis (RO) plants. Feed water was secondary wastewater effluent, river water, and surface water. Membrane autopsies were used for fouling characterization. Fouling layer measurements included total organic carbon (TOC), adenosine triphosphate, polysaccharides, proteins, and heterotrophic plate counts. In all locations, membrane and spacer fouling was (bio)organic. Plant chemical cleaning efficiencies were evaluated from full-scale operational data and cleaning trials in a laboratory setup. Standard cleaning procedures were compared to two cleaning procedures specifically adapted to treat (bio)organic fouling using commercial blend cleaners (mixtures of active substances). The three RO plants were impacted by irreversible foulants causing permanently decreased performance in normalized pressure drop and water permeability even after thorough chemical cleaning. The standard plant and adapted cleaning procedures reduced the TOC by 45% on average, with a maximum of ~80%. In general, around 20% higher biomass removal could be achieved with adapted procedure I compared to adapted procedure II. TOC measurements and SEM showed that none of cleaning procedures applied could remove foulants completely from the membrane elements. This study underlines the need for novel cleaning approaches targeting resistant foulants, as none of the procedures applied resulted in highly effective membrane regeneration. Florian Beyer, Judita Laurinonyte, Arie Zwijnenburg, Alfons J. M. Stams, and Caroline M. Plugge Copyright © 2017 Florian Beyer et al. All rights reserved. Photoluminescence Enhancement Effect of the Layered MoS2 Film Grown by CVD Wed, 07 Jun 2017 06:34:41 +0000 The layered MoS2 films have been prepared by the chemical vapor deposition (CVD) method, which shows numerous MoS2 convex flakes (i.e., MoS2 nanosheets) on SiO2/Si substrates. The convex flake islands form a uniform layered film and the single flake corresponds to one small piece of monolayer MoS2 film; they show a strong photoluminescence (PL) radiation as a whole. The thickness of the layered MoS2 films increases with the increases of growth time, the effect of diverse growth time on the properties of layered MoS2 films has been discussed, and the PL enhancement effect is due to the PL intensity accumulation from each of the convex flakes. The strong PL radiation has been found by annealing the samples and the reason has been analyzed. The layered MoS2 films could provide more photon energy than both the monolayer MoS2 film and the bulk MoS2. This work provides a fundamental study about the device fabrication based on layered MoS2 films. The optoelectronic devices based on this study will be more energy efficient. H. Li, X. H. Zhang, and Z. K. Tang Copyright © 2017 H. Li et al. All rights reserved. Retracted: Power Consumption, Mixing Time, and Oxygen Mass Transfer in a Gas-Liquid Contactor Stirred with a Dual Impeller for Different Spacing Thu, 11 May 2017 00:00:00 +0000 Journal of Engineering Copyright © 2017 Journal of Engineering. All rights reserved. Seismic Performance of Steel Frames with Semirigid Connections Sun, 30 Apr 2017 12:33:11 +0000 The nonlinear stiffness matrix method was incorporated to investigate the structural performance of steel portal frames with semirigid connections. A portal frame with unstiffened extended end-plate connection was designed to demonstrate the adequacy of the proposed method. Besides, the seismic performance of steel portal frames with semirigid connections was investigated through time history analysis where kinematic hysteresis model was assigned to semirigid connections to account for energy dissipation and unloading stiffness. Based on the results of the study, it was found that generally semirigid connections influenced the force distribution which resulted in the decrease in base shear and lighter frame compared to the rigid one. The results also indicated that there was no direct relationship between maximum displacement at the top and connection stiffness in high-rise frames. Iman Faridmehr, Mahmood Md. Tahir, Tom Lahmer, and Mohd Hanim Osman Copyright © 2017 Iman Faridmehr et al. All rights reserved. Dynamic Response of a Circular Tunnel in an Elastic Half Space Wed, 26 Apr 2017 00:00:00 +0000 The vibration of a circular tunnel in an elastic half space subjected to uniformly distributed dynamic pressure at the inner boundary is studied in this paper. For comparison purposes, two different ground materials (soft and hard soil) are considered for the half space. Under the assumption of plane strain, the equations of motion for the tunnel and the surrounding medium are reduced to two wave equations in polar coordinates using Helmholtz potentials. The method of wave expansion is used to construct the displacement fields in terms of displacement potentials. The boundary conditions associated with the problem are satisfied exactly at the inner surface of the tunnel and at the interface between the tunnel and surrounding medium, and they are satisfied approximately at the free surface of the half space. A least-squares technique is used for satisfying the stress-free boundary conditions at the half space. It is shown by comparison that the stresses and displacements are significantly influenced by the properties of the surrounding soil, wave number (i.e., the frequency), depth of embedment, and thickness of the tunnel wall. İrfan Coşkun and Demirhan Dolmaseven Copyright © 2017 İrfan Coşkun and Demirhan Dolmaseven. All rights reserved. High Performance Concrete Materials with Applications in Building and Civil Engineering Wed, 19 Apr 2017 09:17:52 +0000 Peng Zhang, Song Han, Serina Ng, and Xu-Hao Wang Copyright © 2017 Peng Zhang et al. All rights reserved. Experimental and Simulation Research on the Influence of Stirring Parameters on the Distribution of Particles in Cast SiCp/A356 Composites Wed, 19 Apr 2017 00:00:00 +0000 Achieving the uniform distribution of reinforcement particles in MMCs is very important for the effect of stirring parameters and the flow action of the melt, which should be known. The effect of stirring parameters on the distribution of SiC particles in SiCp/A356 composites was studied by the experimental and numerical methods in this paper. The experimental results show the SiC distribution with different stirring parameters. In addition, the effects of the fluid velocity and volume fraction of SiC particle at different position of crucible on the SiC distribution were analyzed by numerical simulation. The velocity magnitude, axial velocity, and radial velocity were analyzed to explain theoretically the particle distribution. The shearing force, moments, and stirring power of the stirring rod were simulated based on CFD code. The numerical results show that the stirring temperature is lower, the shearing force is greater, the stirring time is longer, and particle dispersion gets better. On the other hand, the higher the stirring speed is, the more uniform the radial and axial flow are, and the better the particles were dispersed. The numerical results were in good agreement with the experimental data. Zhiyong Yang, Like Pan, Jianmin Han, Zhiqiang Li, Jialin Wang, Xiang Li, and Weijing Li Copyright © 2017 Zhiyong Yang et al. All rights reserved. Fatigue Life Assessment of Orthotropic Steel Deck with UHPC Pavement Tue, 11 Apr 2017 00:00:00 +0000 In recent years, a number of large-span bridges with orthotropic steel decks were constructed in China. With increasing traffic volumes and higher wheel loads, many fatigue cracks developed at the welds and the edge of cut-out holes. This paper aims at presenting the numerical analysis on the fatigue performance of the orthotropic steel deck using ultrahigh performance concrete (UHPC) overlay as the deck pavement instead of the conventional asphalt concrete pavement. By using finite element method (FEM) model, stress distribution at fatigue sensitive locations under the action of wheel loads is characterized and the obtained stress ranges indicate that the UHPC pavement significantly reduces the magnitude of the stress peak valued. A suggested truck stream model based on the weigh-in-motion (WIM) data of four bridges in China is employed to calculate the stress variation at specific fatigue details. Furthermore, the fatigue damage accumulation at fatigue details under the UHPC and conventional asphalt concrete pavement is studied based on Miner’s linear cumulative damage rule and the rain-flow method. The results indicate that the UHPC pavement on the orthotropic steel deck can extend the service lives of the concerned regions over 100 years, but the fatigue lives will reduce significantly when the elastic modulus of UHPC decreases to 50% of the original value. Xu Jiang, Yuan Yuan, Chong Wu, and Chengwei Luo Copyright © 2017 Xu Jiang et al. All rights reserved. A Field Study on the Indoor Thermal Environment of the Airport Terminal in Tibet Plateau in Winter Sun, 02 Apr 2017 09:58:44 +0000 In order to study the characteristics of indoor thermal environment in the airport terminal in Tibet Plateau with radiant floor heating in winter, a field measurement of the indoor thermal environment was conducted in Lhasa Gonggar Airport terminal 2. First, the unique climate characteristics in Tibet Plateau were analyzed through comparison of meteorological parameters in Beijing and Lahsa. The thermal environment in the terminal was divided into outer zone and inner zone as well as south zone and north zone. Thermal environment parameters including air temperature, black globe temperature, relative humidity in each zone, and inner surface temperature of envelope were measured and analyzed. Meanwhile, temperature and relative humidity in the vertical direction were measured. In addition, PMV and PPD were calculated for evaluating the thermal environment in the terminal. The findings can provide guidance for the design and regulation of thermal environment in terminals in Tibet Plateau in China. Jianglong Zhen, Jun Lu, Guangqin Huang, Liyue Zeng, Jianping Lin, and Hongtao Xia Copyright © 2017 Jianglong Zhen et al. All rights reserved. Study and Development of a Complete System for Recovery, Recycle, and Disposal of Refrigerant Gas from Existent Plants Tue, 28 Mar 2017 00:00:00 +0000 The increasing attention of international community towards ozone depletion control and global warming issues has encouraged the development of strategies for emission reduction of fluoridate refrigerant gases. In this context innovative industrial plants able to recover, recycle, and dispose the refrigerant gases need to be developed. In this paper the different phases of design, realization, and characterization of a complete plant for used refrigerant gas recovery are described. The analysis of the pollutants present in the refrigerant stream has supported the design and realization of equipment able to control these emissions and to restore the concentration levels compatible with AHRI standards. Corrado Genta, Carmine Marotta, and Fortunato Migliardini Copyright © 2017 Corrado Genta et al. All rights reserved. Model of the Mechanical Behavior of Cementitious Matrices Reinforced with Nanomaterials Mon, 20 Mar 2017 07:41:10 +0000 CNTs and CNFs have been introduced as a nanoscale reinforcing material to cementitious composites, for stiffening and strengthening the microstructure. This technology is motivated by the need to control crack initiation in the cementitious gel before it propagates into visible crack formations. Experimental evidence supports this concept; however, testing at the nanoscale may only be conducted through nanoindentation, which has a limited range only providing localized results that cannot be extrapolated to general stress states. To evaluate the restraining action of nanomaterials in the gel microstructure, a computational mechanistic model has been developed where the material phases (gel, nanotubes, and pores) are modeled explicitly allowing for natural randomness in their distribution and orientation. Repeated analysis with identical input data reproduces the statistical scatter observed in laboratory tests on identical material samples. The formulation uses a discrete element approach; the gel structure is represented by a random network of hydrates and successfully reproduces the known trends in mechanical behavior of cementitious materials (pressure and restraint sensitive material behavior) and the small ratio of tensile to compressive strength. Simulations illustrate that it is possible to computationally reproduce the measured properties and behavior of fiber-reinforced cement composites using information from simple laboratory tests. Victor D. Balopoulos, Nikolaos Archontas, and Stavroula J. Pantazopoulou Copyright © 2017 Victor D. Balopoulos et al. All rights reserved. Effects of Adhesive Connection on Composite Action between FRP Bridge Deck and Steel Girder Thu, 16 Mar 2017 00:00:00 +0000 The FRP-steel girder composite bridge system is increasingly used in new constructions of bridges as well as rehabilitation of old bridges. However, the understanding of composite action between FRP decks and steel girders is limited and needs to be systematically investigated. In this paper, depending on the experimental investigations of FRP to steel girder system, the Finite Element (FE) models on experiments were developed and analyzed. Comparison between experiments and FE results indicated that the FE models were much stiffer for in-plane shear stiffness of the FRP deck panel. To modify the FE models, rotational spring elements were added between webs and flanges of FRP decks, to simulate the semirigid connections. Numerical analyses were also conducted on four-point bending experiments of FRP-steel composite girders. Good agreement between experimental results and FE analysis was achieved by comparing the load-deflection curves at midspan and contribution of composite action from FRP decks. With the validated FE models, the parametric studies were conducted on adhesively bonded connection between FRP decks and steel girders, which indicated that the loading transfer capacity of adhesive connection was not simply dependent on the shear modulus or thickness of adhesive layer but dominated by the in-plane shear stiffness . Xu Jiang, Chengwei Luo, Xuhong Qiang, Henk Kolstein, and Frans Bijlaard Copyright © 2017 Xu Jiang et al. All rights reserved. Telefacturing Based Distributed Manufacturing Environment for Optimal Manufacturing Service by Enhancing the Interoperability in the Hubs Tue, 07 Mar 2017 09:45:06 +0000 Recent happenings are surrounding the manufacturing sector leading to intense progress towards the development of effective distributed collaborative manufacturing environments. This evolving collaborative manufacturing not only focuses on digitalisation of this environment but also necessitates service-dependent manufacturing system that offers an uninterrupted approach to a number of diverse, complicated, dynamic manufacturing operations management systems at a common work place (hub). This research presents a novel telefacturing based distributed manufacturing environment for recommending the manufacturing services based on the user preferences. The first step in this direction is to deploy the most advanced tools and techniques, that is, Ontology-based Protégé 5.0 software for transforming the huge stored knowledge/information into XML schema of Ontology Language (OWL) documents and Integration of Process Planning and Scheduling (IPPS) for multijobs in a collaborative manufacturing system. Thereafter, we also investigate the possibilities of allocation of skilled workers to the best feasible operations sequence. In this context, a mathematical model is formulated for the considered objectives, that is, minimization of makespan and total training cost of the workers. With an evolutionary algorithm and developed heuristic algorithm, the performance of the proposed manufacturing system has been improved. Finally, to manifest the capability of the proposed approach, an illustrative example from the real-time manufacturing industry is validated for optimal service recommendation. V. K. Manupati, M. Gokula Krishnan, M. L. R. Varela, and José Machado Copyright © 2017 V. K. Manupati et al. All rights reserved. Investigation of the Effects of Submerged Arc Welding Process Parameters on the Mechanical Properties of Pressure Vessel Steel ASTM A283 Grade A Sun, 05 Feb 2017 00:00:00 +0000 The pressure vessel steel is used in boilers and pressure vessel structure applications. This research studied the effects of submerged arc welding (SAW) process parameters on the mechanical properties of this steel. The weld sample originated from ASTM A283 grade A sheet of 6.00-millimeter thickness. The welding sample was treated using SAW with the variation of three process factors. For the first factor, welding currents of 260, 270, and 280 amperes were investigated. The second factor assessed the travel speed, which was tested at both 10 and 11 millimeters/second. The third factor examined the voltage parameter, which was varied between 28 and 33 volts. Each welding condition was conducted randomly, and each condition was tested a total of three times, using full factorial design. The resulting materials were examined using tensile strength and hardness tests and were observed with optical microscopy (OM) and scanning electron microscopy (SEM). The results showed that the welding current, voltage, and travel speed significantly affected the tensile strength and hardness ( value < 0.05). The optimum SAW parameters were 270 amperes, 33 volts, and 10 millimeters/second travel speed. High density and fine pearlite were discovered and resulted in increased material tensile strength and hardness. Prachya Peasura Copyright © 2017 Prachya Peasura. All rights reserved. Experimental Study on Strain Reliability of Embroidered Passive UHF RFID Textile Tag Antennas and Interconnections Thu, 02 Feb 2017 00:00:00 +0000 We present embroidered antennas and interconnections in passive UHF RFID textile tags and test their strain reliability. Firstly, we fabricate tag antennas on two different stretchable fabric substrates by five different embroidery patterns and choose the most stretchable ones for testing. Next, the tag ICs are attached by sewing and gluing, and the tag reliability during repeated stretching cycles is evaluated through wireless measurements. Initially, the chosen tags achieve read ranges of 6–8 meters and can strain up to 140–150% of their original length. After 100 stretching cycles to 80% of their maximum strain, the read ranges of the tags with glued interconnections are similar to the initial values. In addition, also the read ranges of the tags with sewed interconnections are still more than 70%–85% of their initial values. However, some challenges with the reproducibility need to be solved next. Xiaochen Chen, Aruhan Liu, Zhigang Wei, Leena Ukkonen, and Johanna Virkki Copyright © 2017 Xiaochen Chen et al. All rights reserved. Elastoplastic Modelling of an In Situ Concrete Spalling Experiment Using the Ottosen Failure Criterion Tue, 31 Jan 2017 07:45:20 +0000 An in situ concrete spalling experiment will be carried out in the ONKALO rock characterization facility. The purpose is to establish the failure strength of a thin concrete liner on prestressed rock surface, when the stress states in both rock and concrete are increased by heating. A cylindrical hole 1.5 m in diameter and 7.2 m in depth is reinforced with a 40 mm thin concrete liner from level −3 m down. Eight 6 m long 4 kW electrical heaters are installed around the hole 1 m away. The experiment setup is described and results from predictive numerical modelling are shown. Elastoplastic modelling using the Ottosen failure criterion predicts damage initiation on week 5 and the concrete ultimate strain limit of 0.0035 is exceeded on week 10. The support pressure generated by the liner is 3.2 MPa and the tangential stress of rock is reduced by −33%. In 2D fracture mechanical simulations, the support pressure is 3 MPa and small localized damage occurs after week 3 and damage process slowly continues during week 9 of the heating period. In conclusion, external heating is a potent way of inducing damage and thin concrete liner significantly reduces the amount of damage. Lauri Kalle Tapio Uotinen and Topias Kalle Aleksi Siren Copyright © 2017 Lauri Kalle Tapio Uotinen and Topias Kalle Aleksi Siren. All rights reserved. Free Vibration of Embedded Porous Plate Using Third-Order Shear Deformation and Poroelasticity Theories Tue, 24 Jan 2017 06:40:14 +0000 This research aims at studying free vibration of rectangular plate made of porous materials in which Y-foam, G-foam, and are used and compared with each other. To obtain the Biot formulation of the constitutive equations for a porous material, linear poroelasticity theory is used. Young modulus and density of porous plate are different in transverse direction versus porosity. In order to increase the accuracy of results in comparison with classical plate and first-order shear deformation theories, Reddy’s theory was utilized in this research. Besides, five coupled equations of motion have been studied using Hamilton’s principle and are solved by differential quadrature method (DQM). Detailed results of this study show the significant effect of aspect ratio, thickness ratio, boundary conditions, and porosity on dimensionless frequency and deflection of porous plate. Results of this study can contribute to the design of pneumatic conveying, handling, and control systems. Ali Ghorbanpour Arani, Zahra Khoddami Maraghi, Mehdi Khani, and Iman Alinaghian Copyright © 2017 Ali Ghorbanpour Arani et al. All rights reserved. Flexural Behavior of High-Volume Steel Fiber Cementitious Composite Externally Reinforced with Basalt FRP Sheet Mon, 26 Dec 2016 11:56:44 +0000 High-performance fiber-reinforced cementitious composites (HPFRCCs) are characterized by unique tensile strain hardening and multiple microcracking behaviors. The HPFRCC, which demonstrates remarkable properties such as strength, ductility, toughness, durability, stiffness, and thermal resistance, is a class of fiber cement composite with fine aggregates. It can withstand tensile stresses by forming distributed microcracks owing to the embedded fibers in the concrete, which improve the energy absorption capacity and apparent ductility. This high energy absorbing capacity can be enhanced further by an external stiff fiber-reinforced polymer (FRP). Basalt fabric is externally bonded as a sheet on concrete materials to enhance the durability and resistance to fire and other environmental attacks. This study investigates the flexural performance of an HPFRCC that is externally reinforced with multiple layers of basalt FRP. The HPFRCC considered in the study contains steel fibers at a volume fraction of 8%. Seungwon Kim and Cheolwoo Park Copyright © 2016 Seungwon Kim and Cheolwoo Park. All rights reserved. Fault Tolerant Operation of ISOP Multicell Dc-Dc Converter Using Active Gate Controlled SiC Protection Switch Wed, 21 Dec 2016 11:46:33 +0000 An active gate controlled semiconductor protection switch using SiC-MOSFET is proposed to achieve the fault tolerant operation of ISOP (Input Series and Output Parallel) connected multicell dc-dc converter. The SiC-MOSFET with high temperature capability simplifies the configuration of the protection circuit, and its on-resistance control by the active gate controller realizes the smooth protection without the voltage and the current surges. The first laboratory prototype of the protection switch is fabricated by using a SiC-MOSFET with a high frequency buck chopper for the active gate controller. The effectiveness of the proposed protection switch is verified, taking the impact of the volume reduction into account. Yusuke Hayashi, Yoshikatsu Matsugaki, and Tamotsu Ninomiya Copyright © 2016 Yusuke Hayashi et al. All rights reserved. Bending and Shear Experimental Tests and Numerical Analysis of Composite Slabs Made Up of Lightweight Concrete Tue, 20 Dec 2016 14:11:10 +0000 The aim of this paper is to understand the structural behaviour of composite slabs. These composite slabs are made of steel and different kinds of concrete. The methodology used in this paper combines experimental studies with advanced techniques of numerical simulations. In this paper, four types of concrete were used in order to study their different structural strengths in composite slabs. The materials used were three lightweight concretes, a normal concrete, and a cold conformed steel deck which has embossments to increase the adherence between concrete and steel. Furthermore, two lengths of slabs were studied to compare structural behaviours between short and long slabs. m-k experimental tests were carried out to obtain the flexural behaviour of the composite slabs. These tests provide dimensionless coefficients to compare different sizes of slabs. Nonlinear numerical simulations were performed by means of the finite element method (FEM). Four different multilinear isotropic hardening laws were used to simulate the four concretes. Coulomb friction contact was used to model the coefficient of friction between steel and concrete. Finally, a chemical bond was included to consider sliding resistance in the contact surface between steel and concrete. Experimental and numerical results are in good agreement; therefore, numerical models can be used to improve and optimize lightweight composite slabs. F. P. Alvarez Rabanal, J. Guerrero-Muñoz, M. Alonso-Martinez, and J. E. Martinez-Martinez Copyright © 2016 F. P. Alvarez Rabanal et al. All rights reserved. Analysis of the Single Toggle Jaw Crusher Force Transmission Characteristics Wed, 07 Dec 2016 11:12:47 +0000 This paper sets out to perform a static force analysis of the single toggle jaw crusher mechanism and to obtain the force transmission characteristics of the mechanism. In order to obtain force transmission metrics that are characteristic of the structure of the mechanism, such influences as friction, dead weight, and inertia are considered to be extraneous and neglected. Equations are obtained by considering the balance of forces at the moving joints and appropriately relating these to the input torque and the output torque. A mechanical advantage, the corresponding transmitted torque, and the variations thereof, during the cycle of motion of the mechanism, are obtained. The mechanical advantage that characterizes the mechanism is calculated as the mean value over the active crushing stroke of the mechanism. The force transmission characteristics can be used as criteria for the comparison of different jaw crusher mechanism designs in order to select the most suitable design for a given application. The equations obtained can also be used in estimating the forces sustained by the components of the mechanism. Moses Frank Oduori, David Masinde Munyasi, and Stephen Mwenje Mutuli Copyright © 2016 Moses Frank Oduori et al. All rights reserved. Changing States of Multistage Process Chains Wed, 30 Nov 2016 10:05:33 +0000 Generally, a process describes a change of state of some kind (state transformation). This state change occurs from an initial state to a concluding state. Here, the authors take a step back and take a holistic look at generic processes and process sequences from a state perspective. The novel perspective this concept introduces is that the processes and their parameters are not the priority; they are rather included in the analysis by implication. A supervised machine learning based feature ranking method is used to identify and rank relevant state characteristics and thereby the processes’ inter- and intrarelationships. This is elaborated with simplified examples of possible applications from different domains to make the theoretical concept and results more feasible for readers from varying domains. The presented concept allows for a holistic description and analysis of complex, multistage processes sequences. This stands especially true for process chains where interrelations between processes and states, processes and processes, or states and states are not fully understood, thus where there is a lack of knowledge regarding causations, in dynamic, complex, and high-dimensional environments. Thorsten Wuest, Christopher Irgens, and Klaus-Dieter Thoben Copyright © 2016 Thorsten Wuest et al. All rights reserved.