bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Tests on Extended Stiffened End-Plate Joints within Equal Joints Project
Authors: D'Aniello Mario , Tartaglia Roberto , Costanzo Silvia , Campanella Giuseppe , Landolfo Raffaele , de Martino Attilio
Published: February 2018

Bolted extended stiffened end-plate beam-to-column joints are commonly used for steel moment resisting frames in seismic areas. In the framework of European codes, EN 1993:1-8 provides the design rules and the analytical models to predict the mechanical behavior of the joints. On the other hand, EN 1998-1 specifies the required performance for seismic resistant joints. Within EQUALJOINTS project design rules have been developed and experimental tests were carried out to seismically prequalify extended stiffened end-plate joints. In this paper the proposed design rules are discussed and results of the experimental tests are described.
Experimental Tests for Pre-Qualification of a Set of Buckling-Restrained Braces
Authors: Stratan Aurel , Zub Ciprian Ionut , Dubină Dan
Published: February 2018

Buckling restrained braces are increasingly used as structural fuse elements due to their stable and quasi-symmetric cyclic behaviour and capacity to dissipate a large amount of energy. However, a wider adoption of buckling restrained braced frames is often precluded by the proprietary character of most buckling restrained braces, need for their experimental qualification and sometimes lack of experience of designers. To overcome these problems, a set of typical buckling restrained braces were developed in view of their pre-qualification. Both "conventional" and "dry" devices were considered, with capacities corresponding to typical steel multistorey buildings in Romania. Detailing of buckling restrained braces aimed at investigating the core aspect ratio, gap size, strength of the buckling restraining mechanism, and the unbonding material. The paper presents the results of the experimental program, and recommended design parameters of qualified specimens.
Shake Table Test of a Half-Scale 2-Storey Steel Building Seismically Retrofitted Using Rocking Braced Frame System
Authors: Mottier Paul , Tremblay Robert , Rogers C.A.
Published: February 2018

The article introduces a shake table test program that was conducted to investigate the response of a two-storey rocking braced frame for which self-centring capacity is provided solely by the gravity loads supported by the frame. The test specimen is a 0.5 scaled model of a prototype rocking frame that was studied for the retrofit of a seismically deficient steel structure. The main objectives of the test program were to study the effects of column uplift and impact on shear forces and moments in the beams connected to the columns. Higher mode effects on brace forces were also of interest. Three different energy dissipation mechanisms located at the rocking interface were examined for drift control: friction, ring spring dampers, and vertical steel bars yielding in tension and buckling in compression. By changing the seismic weight of the test specimen, tests could be conducted for structures located in two different seismic regions of Canada to study the effect of the signature of the ground motions. Increases in beam forces due to column uplift and impact, as predicted by previous numerical simulations, were confirmed by the tests. High axial loads induced by the second vibration mode were also measured in the second storey braces.
A Finite Element Study of Non-Orthogonal Bolted Flange Plate Connections for Seismic Applications
Authors: Hunn Zachary D. , Rassati Gian Andrea , Swanson James A. , Burns Thomas M.
Published: February 2018

The current design approach for moment connections in many seismic specifications worldwide focuses on providing energy dissipation to achieve a collapse prevention objective. Most specifications only provide guidance for the design of beam-column connections in orthogonal configurations. However, it is not uncommon that for architectural reasons beams be required to frame into columns at an angle, either with respect to the horizontal (sloped connections) or with respect to a vertical plane (skewed connections), for the design of which little guidance is available. This paper presents a numerical study focusing on Bolted Flange Plate connections in non-orthogonal configurations. The response of these connections was compared to extant experimental results, using orthogonal configurations as a baseline. Investigating the connections response in terms of moment-rotation capacity, stress distributions, plastic strain demands, and plastic hinge locations, some recommendations for the design of non-orthogonal Bolted Flange Plate connections are presented. Secondarily, a study of the influence of specific details on the response of the connections was performed, resulting in practical detailing recommendations.
Computational Challenges in Real-Time Hybrid Simulation of Tall Buildings under Multiple Natural Hazards
Authors: Kolay Chinmoy , Ricles James M. , Marullo Thomas M. , Al-Subaihawi Safwan , Quiel Spencer E.
Published: February 2018

The essence of real-time hybrid simulation (RTHS) is its ability to combine the benefits ofphysical testing with those of computational simulations. Therefore, an understanding of the real-timecomputational issues and challenges is important, especially for RTHS of large systems, in advancingthe state of the art. To this end, RTHS of a 40-story (plus 4 basement stories) tall building havingnonlinear energy dissipation devices for mitigation of multiple natural hazards, including earthquakeand wind events, were conducted at the NHERI Lehigh Experimental Facility. An efficient implementationprocedure of the recently proposed explicit modified KR-a (MKR-a) method was developedfor performing the RTHS. This paper discusses this implementation procedure and the real-time computationalissues and challenges with regard to this implementation procedure. Some results from theRTHS involving earthquake loading are presented to highlight the need for and application of RTHSin performance based design of tall buildings under earthquake hazard.
Numerical Study of Asymmetric Friction Connections (AFC) with Large Grip Length Bolts
Authors: Hatami Mandi , MacRae Gregory A. , Rodgers Geoffrey W. , Clifton George Charles
Published: February 2018

A Finite Element (FE) model is used to simulate the experimental behaviour of high strength bolts in asymmetric friction connections (AFC). Two M16 connections tested previously are modelled using ABAQUS and are subjected to cyclic lateral displacements. The numerical results were similar to that from previous experimental studies. It was also shown that hysteresis loop strength and stability reduced for longer bolt grip lengths. Other information, which cannot be easily monitored in experimental tests, such as the bearing stress distribution between plates, component equivalent plastic strain, and bolt tension force, were obtained at different sliding distances. It was shown that bolt and plate plastic deformation tended to occur in bolts with a long grip length to bolt diameter ratio.
Lessons from the Field; Steel Structure Performance in Earthquakes in New Zealand from 2010 to 2016
Authors: Clifton George Charles , MacRae Gregory A.
Published: February 2018

First the Canterbury earthquake series of 2010/2012 and then the Kaikoura Earthquake of 2016 have significantly impacted the building stock in central and southern New Zealand, subjecting a wide range of buildings and building components to earthquake shaking ranging from moderate to severe. The economic and social costs of these earthquakes have been severe, but the lessons learned on how buildings and building systems designed and detailed to New Zealand provisions have performed have been invaluable. We have learned more about this from these earthquakes then from the many reconnaissance trips undertaken to overseas earthquakes over the 50 years of the New Zealand Society for Earthquake Engineering. This paper focusses on the performance of steel framed buildings in two major New Zealand cities, Christchurch and Wellington, with greatest emphasis on multi-storey buildings, but also covering light steel framed housing. It addresses such issues as the magnitude and structural impact of the earthquake series, how the various systems performed against the design expectations and briefly covers some of the research underway to quantify where there were differences between the observed performance and the expected performance.
Design and Assessment of Cold-Formed Steel Shear Wall Systems Located in Moderate-to-High Seismicity Regions
Authors: Kechidi Smail , Macedo Luís , Castro José Miguel , Bourahla Nouredine
Published: February 2018

This paper presents a numerical simulation aimed at analysing the seismic performance of low- and mid-rise cold-formed steel (CFS) framed buildings, employing wood-sheathed shear wall panels (SWPs), designed according to a seismic design procedure compatible with the framework of the Eurocodes. To simulate their nonlinear behaviour, the structures were modelled adopting a recently developed deteriorating hysteresis model. In order to study the seismic performance and determine the seismic performance factors, Incremental Dynamic Analysis of 54 archetype buildings was performed in OpenSees. The seismic performance assessment was evaluated according to the methodology defined in FEMA P695. The results indicate that a behaviour factor q equal to 2 is appropriate for CFS framed structures using wood-sheathed SWPs lateral load resisting system designed for low and moderate seismicity regions. Further, the probabilistic seismic risk assessment of the studied frames, is presented. The importance and usefulness of the risk metrics are highlighted and adopted as an indicator to explore the behavioural features of the CFS-SWP structural system. Overall, the assessment procedure showed an acceptable seismic performance and therefore the CFS-SWP can be seen as a reliable structural solution to achieve performance-based objectives even in moderate-to-high seismicity regions.
Collapse Mechanisms of Controlled Rocking Steel Braced Frames: Base Rocking Joint vs. Capacity-Protected Frame Members
Authors: Steele Taylor C. , Wiebe Lydell D.A.
Published: February 2018

Controlled rocking steel braced frames (CRSBFs) have been proposed as a low-damage seismic force resisting system with reliable self-centering capabilities. The frame members in CRSBFs are selected to remain elastic during design-level earthquakes, so they must be designed to resist the peak forces from at least the first-mode pushover response. However, several researchers have shown that higher mode effects can contribute significantly to the peak member forces. Some collapse assessment studies on CRSBFs have included member yielding and buckling in the numerical models, but the studies have not examined a range of possible design intensities for the higher modes, and have not separated the influence on the collapse risk of the capacity design from that of the design of the base rocking joint. This paper presents the collapse assessment results for 12-story CRSBFs that were designed either excluding the higher-mode forces, or including the higher-mode forces at the DBE level, MCE level 1.5 times the MCE level, and 2.0 times the MCE level. The ground motions were selected conditionally based on the first-mode period of each example frame. The probability of collapse during an MCE-level event was computed for the frames when buckling and yielding of the frame members was modeled, and compared to the probabilities of collapse when the members were modeled as elastic. The results indicate that the base rocking joint design was more conservative than required to provide adequate collapse prevention compared to the design of the frame members. Including the higher-mode forces at the MCE level for capacity design seems appropriate from a collapse prevention perspective.
Damage Avoidance Self-Centering Steel Moment Resisting Frames (MRFs) Using Innovative Resilient Slip Friction Joints (RSFJs)
Authors: Hashemi Ashkan , Zarnani Pouyan , Darani Farhad Mohammadi , Valadbeigi Armin , Clifton George Charles , Quenneville Pierre
Published: February 2018

Higher seismic performance can be achieved by localizing the inelastic deformation in the connections (fuses) and minimizing the residual drift that are often a determining factor in whether a structure can be repaired or re-occupied after an earthquake. This paper introduces the self-centering damage avoidance steel Moment Resisting Frames (MRFs) using innovative Resilient Slip Friction Joints (RSFJs). The RSFJ provides self-centering and energy dissipation in one compact package requiring no post-event maintenance. In this concept, the beam is connected to the column through a pinned joint at the top, an RSFJ at the bottom and a slotted web plate for transferring the shear forces, when required. The RSFJ allows for gap opening in the connection upon loading and then re-centers the system when unloading. Furthermore, a secondary fuse within the RSFJ is considered to keep maintaining a ductile behavior in the system in case of an earthquake larger than the design earthquake. The conducted experimental tests confirmed the outcomes of this study.
The Sliding Hinge Joint: Final Steps towards an Optimum Low Damage Seismic-Resistant Steel System
Authors: Ramhormozian Shahab , Clifton George Charles , MacRae Gregory A. , Khoo Hsen Han
Published: February 2018

The Sliding Hinge Joint with Asymmetric Friction Connectors (SHJ), to give its full name, is a semi-rigid moment resisting joint used between the beams and columns of a moment-resisting steel frame and also at the column base between the column and the ground. It’s performance is intended to be as follows: 1) On completion of construction, rigid under serviceability limit state conditions, 2) During a severe earthquake, allowing controlled rotation between the column and the beam or foundation on designated friction sliding planes within the connection, then 3) Returning to its rigid in-service condition at the end of the severe shaking with the building returning to its pre-earthquake position (self-centering). During its development and proof of concept through large scale testing, the initial results showed that the SHJ as originally designed and detailed performs 1) and 2) very well, but the bolts in the friction sliding planes loose much of their original installed bolt tension during significant sliding, lowering the level at which rotation within the joint will occur post severe earthquake. A concerted research programme of component testing, analytical model development and numerical modelling in recent years has developed solutions to the bolt tension loss issue as well as enhanced the joint’s performance to deliver dependable self-centering capability for the building. This work marks the final steps towards developing an optimum low damage seismic-resisting steel moment frame system. This paper presents key findings from the research work and general recommendations for the optimum performing sliding hinge joint.
Influence of Composite Slab on the Nonlinear Response of Extended End-Plate Beam-to-Column Joints
Authors: Tartaglia Roberto , D'Aniello Mario , Rassati Gian Andrea , Swanson James A. , Landolfo Raffaele
Published: February 2018

Extended stiffened end-plate connections are widely used in seismic area due to their good performance in terms of both resistance and ductility. The most of existing studies focused on the all-steel behavior of these joints, disregarding the composite action of the concrete slab that is generally disconnected. However, the presence of the concrete slab can have beneficial effects on the structural stiffness for both gravity and lateral loads. Hence, most of the building frames are usually designed considering steel-concrete composite solution. However, the slab can strongly influence the hierarchy between beam and column and the ductility of the joint. In this paper the influence of composite deck on the response of extended stiffened end-plate joins has been investigated by means of finite element analyses (FEAs). In particular, the following details have been investigated: (i) all steel joints without slab; (ii) steel joint with disconnected slab; (iii) composite joint.
The Effect of Consecutive Earthquakes on a Composite Structure Utilising RBRFs
Authors: Oktavianus Yusak , Goldsworthy Helen , Gad Emad , Fernando Saman
Published: February 2018

Low-damage technologies have been developed in recent years which limit the damage imposed on structural elements when a building is subjected to a very rare earthquake event. This has been achieved by a capacity design approach applied to the connections in which the ductile part of the connections yields and all other structural elements remain elastic. Examples of low-damage connections are the sliding hinge joint in steel buildings and variations associated with this, and a combination of a post-tensioning system and mild steel dissipater in precast concrete and timber buildings. A system developed by the authors uses replaceable buckling restrained fuses (RBRFs) that do not require a post-tensioning system to be used conjointly. This system has been studied both experimentally and numerically. This paper considers the use of RBRFs as an energy dissipation device installed at beam-column connections in composite moment-resistant frames. These RBRFs could be replaced after a major event, and hence would cause little disruption. A 2D building frame has been modelled for a case study and its behaviour under 100-year, 500-year and 2500-year return period earthquake events has been summarised. A consecutive earthquake with a return period of 500 years or 2500 years has been applied to the building following both 500-year and 2500-year return period earthquake events. This study was performed since there is a possibility that the consecutive earthquake would occur prior to the replacement of the RBRFs. The results show that the building could still sustain the consecutive earthquakes with little additional residual displacement.
Seismic Performance of Steel MRF Structures with Nonlinear Viscous Dampers from Real-Time Hybrid Simulations
Authors: Dong Bai Ping , Sause Richard , Ricles James M.
Published: February 2018

Real-time hybrid earthquake simulations (RTHS) were performed on steel moment-resisting frame (MRF) structures with nonlinear viscous dampers. The test structures for the RTHS contain a moment-resisting frame (MRF), a frame with nonlinear viscous dampers (DBF), and a gravity load system with associated seismic mass and gravity loads. The MRFs have reduced beam section beam-to-column connections and are designed for 100%, 75%, and 60%, respectively, of the base shear strength required by ASCE 7-10. RTHS were performed to evaluate the seismic performance of these MRF structures. Two phases of RTHS were conducted: (Phase-1) the DBF is the experimental substructure in the laboratory; and (Phase-2) the DBF with the MRF is the experimental substructure. Results from the two phases of RTHS are evaluated. The evaluation shows that the RTHS provide a realistic and accurate simulation of the seismic response of the test structures. The evaluation also shows that steel MRF structures designed with reduced strength and with nonlinear viscous dampers can have excellent seismic performance.
The Thermal Stress Simulation of the Part Caused by Layer Thickness and Deposition Velocity in FDM Process
Authors: Zhou Yi Ren , Qiu Xiao Lin , Hu Miao , Li Jie
Published: February 2018

The paper mainly simulates the effects of layer thickness and deposition velocity on thermal stress in fused deposition modelling (FDM). Different values of these variables are considered in this process. The simulation results show the trends of thermal stress with the two variables and the simulation results provide a guidance for the practical fabrication.
Quantitative Study on Abrasive Belt Wear Based on Geometric Parameters
Authors: He Zhe , Li Jian Yong , Wu Yue Feng , Liu Yue Ming
Published: February 2018

In this paper, based on micro wear form, an approach that using protrusion height, average tool angle, blunt area ratio and coated density to describe the wear of abrasive belt is put forward. The method for calculating the above parameters are also introduced. In experiments, we use the profilometer to collect the abrasive belt surface data and draw figures of the above parameters under service time, which indicates that using topography parameters can describe the degree of belt wear. According to parameters changing slope, the abrasive belt service time is roughly divided into two stages, initial wear stage and stable wear stage but no abrupt wear stage. Initial worn stage grains suffer more stress, patterns of wear are mainly severe wear and pull-off, while stable wear stage grains bear less stress and pattern of worn is dominated by mild wear. In addition to that, the other parameters changing trend is agreed and synchronous with protrusion height.
Application of 3D-DIC Method on Crack Forming Process of Concrete under Axial Compression
Authors: Wang Li Jie , Li Jing Jie , Qi Yu Ming , Tan Xiao Hua , Deng San Peng , Li Qiu
Published: February 2018

Applying 3D digital image correlation (3D-DIC) method to observe and investigate on crack forming process of C45 cylinder concrete under axial compression. The three-dimensional displacement and strain of the exterior surface of C45 concrete during the failure process are obtained. Furthermore, the location and shape of the crack are predicted with the generation, variation and aggregation of the maximum strain equipotential line on the concrete surface. The results show that the applying of 3D-DIC method can accurately obtain the concrete strain distribution data, predict the crack development trend and provide an important basis for further study on the mechanism of damage and fracture characteristics of concrete structure.
Research on Milling Force in Ultrasonic Assisted End Milling of Titanium Alloy Thin-Walled Parts
Authors: Jiao Feng , Yao Cheng Lin , Zhao Li , Qi Feng
Published: February 2018

Hard machinability of titanium alloy material and poor stiffness of thin-walled part restricted the extensive applications of titanium alloy thin-walled component in aerospace engineering. In order to increase geometric accuracy, a method of ultrasonic vibration assisted (UVA) end milling technology with workpiece vibrating in feeding direction was put forward in this paper, and the corresponding milling force characteristics in UVA milling of titanium alloy TC4 thin-walled workpiece were researched. Through theoretical analysis, the path of cutter tooth in UVA milling was analyzed. The important factors that affect milling force are obtained with the signal to noise ratio analysis. Results show that the radial cutting force in UVA milling is smaller than that in traditional milling. Cutting force fluctuate in high frequency when treated ultrasonic vibration. And the axial cutting feed is the core factor that affects the milling force. The research provides a certain reference for the precision milling of titanium alloy thin-walled parts.
Effect of Current Density on the Microstructure and Corrosion Properties of MAO Coatings on Aluminum Alloy Shock Absorber
Authors: Shen Yan , Wang Hong Xiang , Pan Yi Peng
Published: February 2018

In order to improve the corrosion resistance of shock absorber for ships, the alumina ceramic coatings are carried out on the surface of aluminum alloy shock absorber by micro arc oxidation (MAO) technology. The microstructure and anti-corrosion performance of the MAO coatings were investigated experimentally. This paper mainly focuses on the experimental work to determine the effect of current density on the structural characteristics and corrosion resistance of MAO coatings. The results show that the current density has a significant influence on the preparation of MAO coating during the process. The surface of the coating becomes more compact and smooth with the cathode voltage of 7 A.dm-2. Furthermore, the anti-corrosion performance of the MAO coatings can effectively be improved at the current density of 7 A.dm-2.
Feed Optimization of Cycloidal Bevel Gear Format Cutting Based on Equal Cutting Area
Authors: Yong Wang , Zhang Yue , Cao Zhuo Yao , Yao Jian Guang , Shi Meng Kun , Cao Xing Ye
Published: February 2018

When machining the cycloidal bevel gear on the CNC machine tool, the cutting force is gradually increased with the increase of the cutting depth when the feed speed of the cutter head is constant. The fluctuation of the cutting force is easy to cause the spindle vibration, reduce the surface quality. The off-line control is mainly used to optimize the NC code, and the cutting feed in the NC code is segmented according to the corresponding optimization algorithm and the constraint condition. When the spindle speed is 90 rpm, constant feed 40 mm/min, the cutting force of the volatility of 127.45%. When the feed rate is reduced from 50 mm/min to 26mm/min, the fluctuation rate of the cutting force is 46%. The variable feed control can effectively reduce the amplitude fluctuation of the cutting force.
Study on Simulation of Stamping Forming and Die Surface Optimization of Aluminum Alloy Plate
Authors: Hu Miao , Yang Zhi Qiang , Cao Xiao Lin , Yang Qing , Chen Yu , Li Xin
Published: February 2018

Along with the automobile lightweight development, aluminum has become the focus of its own material characteristics. The aluminum alloy products with high efficiency, high quality and low cost are the guarantee of competitive advantage. High quality die surface is directly related to the product quality, cost, production efficiency, die life and so on. In this paper, the stamping process of two kinds of aluminum alloy products was simulated by Auto Form. The method of setting blank holding force and spring back compensation was introduced. At the same time, the setting of parameters such as die fillet, friction coefficient and draw bead was described in this paper. Finally, the optimization of die surface design was achieved by simulation.
Study on Microstructure and Properties of Nanocomposite Coating Prepared on the Surface of Exhaust Pipe for Ship
Authors: Shen Yan , Pan Yi Peng , Wang Hong Xiang
Published: February 2018

In order to improve the high temperature oxidation resistance of exhaust pipes, the nanocomposite coatings are carried out on the surface of exhaust pipe by electrodeposition technology, and the microstructure and oxidation behavior of the nanocomposite coatings are investigated experimentally. This paper mainly focuses on the experimental work to determine the structural characteristics and oxidation resistance of nanocomposite coatings in presence of Al2O3 and cerium oxide CeO2. The results show that the amount of the Al2O3-CeO2 has significant influence on the structural properties of nanocomposite coatings. The surface of coating becomes more compact and smooth with the increase of the amount of the Al2O3 and CeO2. Furthermore, the anti-oxidation performance of the nanocomposite coatings formed with Al2O3 and CeO2 were both better than those of the composite coatings formed without Al2O3 and CeO2.
Experimental Study on Surface Element Composition and Hydrophobic Properties of DLC Coating
Authors: Dong Chuang He , Wei Xiu Ting , Li Zhi Yong , Shi Wei Liang , Wang Zhi Gang
Published: February 2018

Precision rubber mold is an extremely important basic process equipment in industrial production, however, there are some classic problems, such as viscose, coke accumulation and difficult demoulding, can not be effectively resolved. In order to solve this problem, in this paper, a new process of preparing high performance DLC coated precision rubber mold is proposed by using the excellent anti-sticking properties, self-cleaning properties and hydrophobic properties of DLC coating. In the experiment, steel ( S35C ) substrate with the same material as tire mold is used. Hydrophobic of DLC coating surface mainly depends on the surface element composition and the roughness. All the substrates are exactly processed, so as to ensure that the roughness has minimal impact on hydrophobic. Plasma enhanced chemical vapor deposition (PECVD) technology is employed to prepare fluorine doped diamond-like carbon (F-DLC) coating and hydrogenated diamond-like carbon (a-C:H) coating. Arc ion plating (AIP) technology is applied to produce Non-hydrogenated diamond-like carbon (a-C) coating. The coating is deposited on the surface of steel ( S35C ). Then, the roughness, the element composition and the hydrophobicity of the prepared coating are tested. Experimental results demonstrate that the water contact angle of a-C coating only 73.8 degrees, water contact angle of a-C:H coating up to 80.16 degrees, however, water contact angle of F-DLC coating could reach to 89.01 degrees, meanwhile, the surface energy can be reduced to 22.62 mN/m. To some extent, the hydrophobicity of the coating enhances with the increase of H content, and the content of weak polarization group CF2 becomes stable with the incorporation of F element. As a consequence, the surface of coating becomes smoother and the wettability of coating and water becomes poorer, therefore the performance of hydrophobic of the coating is further enhanced.
Advancements in Properties of Cement Containing Pulverised Fly Ash and Nanomaterials by Blending and Ultrasonication Method (Review - Part I)
Authors: Kirgiz Mehmet Serkan
Published: February 2018

This review research aims to discuss the results obtained researches on cement containing pure cement, pulverised fly ash, and nanoparticles, in order for eliminating negative side effects underlie the substitution of by–products for pure Portland cement. Nanoparticles (NP) used in these researches are nanoTiO2, nanoSiO2, nanoCaCO3, fibers of carbon nano tube (CNT), nanolimestone (nanoCaCO3), nanoZrO2, nanoclays, and nanometakaolin (nMK) for improving properties of cement systems. Published manuscripts explains two methods regarding on the usage of nanoparticles for cement system: blending and ultrasonication for dispersion of nanoparticles. However, differences between blending and ultrasonication methods suggested by various researchers are also discussed. Experiments reported these papers include the water demand, the density, the setting–times, the heat of hydration, the fluidity, the compressive strength and the flexural strength. According to these results, nanoparticles increase the water demand and heat of hydration of cement; it decreases the density and fluidity for cement mortars, evidently. The most effective nanoparticles on early compressive and flexural strengths are fibers of carbon nano tube and nanoCaCO3. These papers also point effects of these nanoparticles on the strength gain of cement. This review paper inform us until Effect of nanomaterial on water demand and density section in this Part I. Second part of this review paper will explain Hydration properties of Portland pulverised fly ash cement section, Effect of nanomaterial on setting–time section, Effect of nanomaterial on heat of hydration section, Strength gain mechanisms for hardened Portland pulverised fly ash cement paste and mortar section, Effect of nanomaterial on compressive strength section, Effect of nanomaterial on flexural strength (Bending) section, and Conclusion section.
Innovative Composites with Carbon Nanofillers for Self-Sensing Structural RC Beams
Authors: D'Alessandro A. , Meoni A. , Ubertini F.
Published: February 2018

The progress of nanotechnology resulted in the development of new instruments in the civil engineering and its applications. In particular, the use of carbon nanofillers into the matrix of construction materials can provide enhanced properties to the material in both of mechanical and electrical performance. In constructions, concrete is among the most used material. Due to the peculiarities of its components and its structure, it is suitable to modifications, at the nanometer level too. Moreover, to guarantee structural safety it is desirable to achieve a diffuse monitoring of structures in order to identify incipient situations of damages and possible risk for people. The ideal solution would be to realize structures able to identify easily and quickly their behavior modifications. This paper presents a research work about the characterization of the self-sensing abilities of novel cementitious composites with conductive carbon nanoinclusions and their application into a structural reinforced concrete beam. The self-sensing evidence is achieved through the correlation between the variation of strains and the variation of electrical resistance or resistivity. Nanomodified cement pastes with different carbon nanofillers has been tested. The experimental campaign shows the potentialities of this new types of sensors made of nanomodified concrete for diffuse Structural Health Monitoring.
Assessment of the Medmont C100 test for colour vision screening of male Saudi Arabians
Authors: Alotaibi Abdullah Z. , Ikpotokin Emmanuel A. , Oriowo O. Matthew
Published: February 2018

Purpose: To assess the Medmont C100 test as a colour vision screening tool. Methods: One hundred and seventeen young male adults were screened with the Medmont C100, Ishihara plates, and the screening mode of the Oculus Anomaloscope tests.  All subjects were tested under constant room illumination, namely that of a day light fluorescent lamp at 200 lux. Inclusion criteria were visual acuities (VA) of 20/20 or better with or without correction and absence of known ocular pathologies.  Aided and unaided visual acuities were measured with the Snellen VA chart. Results: Five out of the 117 subjects, were found to have red-green colour vision deficiency (CVD) with Ishihara and anomaloscope tests indicating a 4.7% CVD prevalence, while the Medmont C100 test yielded 33 cases ofred-green deficiency indicating CVD prevalence of 28%.  With the Ishihara test, all five subjects were identified as deutans, while the anomaloscope revealed three as deutans and two as pro-tans, and the Medmont C100 test identified all 33 cases as protans. Conclusion:  The Medmont C100 test yielded significantly higher prevalence of protan CVD compared with the Ishihara platesand Anomaloscope tests. These findings suggest that caution should be taken when using Medmont C100 test for colour vision screening as it tends to give more false positive results with bias for pro-tans.  (S Afr Optom 2011 70(1) 14-20)
Teologie in ’n tyd van Sekularisme
Authors: Du Toit S.
Published: February 2018

Oorspronklik was dit die bedoeling om slegs die werke van Kuitert (Realiteit van het geloof), A. C. Porteous (Prophetic voices in contemporary theology) en Heyns (Die evangelie in die krisis) te bespreek. Maar die vraagstuk het almeer geboei. Al gaande het die artikel in omvang gegroei en het dit duidelik geword dat ons hier met die teologiese vraagstuk van ons tyd te doen het.
Fair value intensity and analyst forecasts
Authors: Badenhorst Wessel M.
Published: February 2018

Analysts’ earnings and book value forecasts play an important role in price discovery in equity markets. As the role of fair value measurements in accounting increases, the impact on analysts’ ability to accurately forecast earnings and book values is unclear. This article develops a method to calculate the degree of fair value measurement in financial statements and investigates the impact thereof on the accuracy of analysts’ book value and earnings forecasts, using a sample of firms listed in the United States and the United Kingdom from 2010 to 2014. Relying on multivariate regression findings, the article shows that greater fair value intensity decreases the 12-month analyst forecast accuracy for earnings in both countries. Moreover, there is some evidence that higher fair value intensity decreases the accuracy of analysts’ book value forecasts. It therefore appears that increased fair value intensity under a mixed measurement approach limits the ability of analysts to forecast earnings, without a compensating impact on forecasts of book values.
The effects of soluble corn fibre and isomaltooligosacharides on blood glucose, insulin, digestion and fermentation in healthy young males and females
Authors: Lowery Ryan P. , Wilson Jacob M. , Barninger Andrew , Sharp Matthew H. , Irvin Christopher , Stefan Matthew , Wallace William A. , Wilson Gabriel J. , Roberts Michael D. , Wagner Ronald
Published: February 2018

Dietary fibre refers to nutrients in the diet that gastrointestinal enzymes do not digest. If properly labelled, dietary fibres should not significantly elevate blood glucose or insulin and should ferment in the large intestine. Because of the recent rise in low-carbohydrate products on the market, consumers use these various fibres without adequate knowledge concerning whether or not these ingredients affect any blood parameters and constitute a dietary fibre. The aim of this study was to examine the impact of isomaltooligosaccharides (IMO) as compared to soluble corn fibre (SCF) consumption on blood glucose, insulin and breath hydrogen responses in healthy young men and women. After an overnight fast, nine individuals consumed 25 g of either placebo (PLA), IMO or SCF. Breath hydrogen was significantly higher in the SCF condition than in the IMO and PLA at 90, 120, 150 and 180 min (p  0.0001). Blood glucose and insulin were higher in the IMO condition (p  0.0001) at 30 min compared to the SCF or PLA conditions, which were not significantly different from each other. These data suggest that IMO does not constitute a dietary fibre and instead should be explored as a slow-digesting carbohydrate.
The emergence of logistics cities: Conceptual model
Authors: Sengpiehl C. , Oakden R. , Nagel P. , Toh K. T.K. , Shi P.
Published: February 2018

This paper describes the emergence of logistics cities, which are geographical concentrations of related industries situated around one or more international trade gateways adjacent to a metropolitan area. Broadly, a logistics city comprises logistics activities and related assets combined with an integrated mix of manufacturing and assembly companies, business services, retail outlets, research and education centres, and associated government services and administration sections. This concept is currently being promoted and developed globally by several regions, and examples of these logistics cities are described in this paper. Drawing from these examples and the limited available literature, a preliminary conceptual map of the logistics cities concept has been developed which incorporates a theoretical foundation of economic development and the principles of competitiveness in the notion of trade clusters. This map has provided the basis for our further investigations and the continued development of a more detailed conceptual model that will provide a systematic knowledge base for those engaged in the development of further logistics cities. The beneficiaries of this model will be public authorities, property developers and industrial concerns, and will be used when making decisions for future logistics infrastructure, services, supporting services and related social elements.
Enacting outsourcing: An innovation process perspective
Authors: Borgström Benedikte , Hertz Susanne
Published: February 2018

Much research has been done on outsourcing. However, we still know little about outsourcing based on a social process view on innovation. Outsourcing is an innovation as a logistics-related process that is perceived as new by the adopter. We will explore and analyse an outsourcing idea, its development and implementation, from an innovation perspective. The development is studied in a qualitative, long-term process study. The analysis draws on Hoholm’s (2009) model of innovation processes. It extends the applicability of this innovation model and its methodology of following the action into logistics and supply chain management (SCM) research. The outsourcing process is an innovation that develops in a rational way based on the incremental process because of its actor-network and simultaneous reflection. Interactions and confrontations come about because of involved contrary forces such as competing objectives. The model explains the practice of SCM innovation and increases the understanding of dynamics and complexity. The process study brings insights to cause-effect relations in the development of outsourcing that are consequential to innovative logistics and SCM.
Childhood education student teachers responses to a simulation game on food security
Authors: Petersen Nadine Felicity
Published: February 2018

This paper provides an account of student teachers responses to a simulation game about food scarcity and how the game served as a conversation starter about the influence of food scarcity on educational provisioning. The simulation game was utilised as part of a suite of activities during an educational excursion for first years in primary school teacher education. In this investigation data were generated via video recordings of the simulation game itself, summary notes of the key points of the discussion session during the game, and students’ learning portfolios. Analysis of the various data sets indicate that student-teachers’ engaged with the game both viscerally and cerebrally, with the game providing a powerful concrete introduction to the issues of food scarcity and unequal distribution of resources. Most student teachers were able to relate the lessons learned from the game to the classroom and educational situation. In addition, I found that the simulation game as method can assist students in their activity of learning to look at education as an equity and justice issue.
Internet access and its relationship to subjective well-being in a developing region
Authors: Greyling Talita
Published: February 2018

Internet access has been shown to play an important developmental role and Internet access to all people has become an international goal. This is also true for South Africa where the ‘South Africa Connect’ policy was introduced in 2013. The question arises whether Internet access goes beyond meeting developmental goals to improving the subjective well-being of people. Furthermore, if the association between Internet access and subjective well-being vary between different race and age groups. Previous research was performed in developed countries at a national level or for specific small subsamples, like the elderly; however, this study contributes to the literature by analysing a substantial sample, at sub-national level, in a heterogeneous, unequal society, in a developing country. The benefit is that heterogeneities masked in studies at a national, macro level are highlighted in a study at a sub-national, micro level. This article investigated the relationship between subjective well-being and Internet access within a developing region with a heterogeneous, unequal society. The article used a data set representative of the Gauteng population, the economic centre of South Africa, which was collected in 2013 by the Gauteng City Region Observatory. To analyse the data, ordered probit, ordinary least square and instrumental variable regression techniques were used. The results show that Internet access is positively related to subjective well-being and this relationship holds across all race groups and all age groups, from 18 years to over 65 years of age. In addition, it seems that the stark inequalities between race groups present in South Africa are fading among younger generations. Based on the results, the ‘South Africa Connect’ policy, which aims to give Internet access to all people, including those in Gauteng, the region analysed, is supported, as it not only contributes to the development of the region but also to the life satisfaction of the citizens.
Hydro-Galvanic and Rising - Temperature Bath Therapy For Chronic Elbow Epicondylitis: A comparative Study
Authors: Muncha C.
Published: February 2018

The efficacy of two different regimens of physiotherapy for epicon-dylitis was compared. A combination treatment with hydrogalvanic four-cell bath and arm bath with rising temperature, which had showed good effects in treatmen of tennis elbow in an earlier observational study (Mucha 1987), was compared with the analgesic interference current treatment often recommended in the literature (Sadil and Sadil 1994, Noteboom et al 1994, Becker and Reuter 1982).For this study, 60 patients with epicondylitis that was resistant to conservative reatment were randomized into two groups for comparison. In group 1, interference currents were administered twicea day for six weeks and group 2 received combination treatment with the hydrogalvanic four-cell bath and risingt emperature arm bath once a day for six weeks.Criteria for inclusion, control and appraisal were laid down prospectively. Several parameters were used, recordedand statistically evaluated as outcome measures.  These were active joint range of movement of the elbow, grip strength,pain provocation with muscle contraction, palpation pain and pain with functional activities. The results showed a significant superiority of combination treatment over therapy with interference current. It istherefore recommended that hydrogalvanic four-cell bath and arm bath with rising temperature should be carried outbefore considering surgical treatment for chronic epicondylitis.
Three-Dimensional Computer Model of Benign Paroxysmal Positional Vertigo in the Semi-Circular Canal
Authors: Milosevic Zarko , Saveljic Igor , Nikolic Dalibor , Zdravkovic Nebojsa , Filipovic Nenad , Vidanovic Neda
Published: February 2018

Benign Paroxysmal Positional Vertigo (BPPV) is the most common vestibular disorder. In this paper we tried to investigate a model of the semi-circular canal (SCC) with parametrically defined dimension and full 3D three SCC from patient-specific 3D reconstruction. Full Navier-Stokes equations and continuity equations are used for fluid domain with Arbitrary-Lagrangian Eulerian (ALE) formulation for mesh motion. Fluid-structure interaction for fluid coupling with cupula deformation is used. Particle tracking algorithm has been used for particle motion. Velocity distribution, shear stress and force from endolymph side are presented for one parametric SCC and three patient-specific SCC. All models are used for correlation with the same experimental protocols with head moving and nystagmus eye tracking.
Fractional Flow Reserve: Comparison between Invasive and Non-invasive Methods for Calculation of FFR
Authors: Starcevic S. , Djorovic S. , Filipovic N.
Published: February 2018

The heart disease that affects millions of people worldwide is coronary artery disease. It is caused by a narrowing or blocking of the arteries due to plaque which restricts blood flow, and reduces the amount of oxygen to the heart. Angiogram as a tool, which represents an X-ray examination of the blood vessels in the heart, is traditional tool that aid physicians in the treatment of disease. The severity of blood flow blockages in the coronary arteries is indicated by a fractional flow reserve (FFR) and allows physicians to identify which specific lesion or lesions are responsible for patient ischemia. In this paper, the mathematical model for measuring FFR is derived, and compared with results that were obtained from simulations and angiographically based methods. This analytical model and simulations help to measure values of FFR, by non-invasive methods, only by using reconstructed geometries of coronary arteries with stenosis.