bluuebunny/crossref_metadata_2025 huggingface dataset:
A Thermodynamic Approach to a Density Model for Oxide Melts
Authors: Persson Mikael , Zhang Jiayun , Seetharaman Seshadri
Published: December 2016

In an attempt to estimate the densities of complex slags, a model based on the thermodynamics of slags developed earlier by the present authors is extended to ternary and multi‐component systems in the present work. The molar volumes of ternary and higher order systems were derived from the relative integral molar enthalpies of mixing of the corresponding slags. The higher order of slag systems has been predicted by using the parameters from the related binary sub‐systems, which have been evaluated earlier. Comparisons of calculated results with experimental data on molar volumes available in literature show a satisfying agreement for a number of systems, within the limits of experimental uncertainties. The model presents a promising method to compute the molar volume of slag systems where no experimental data is available using the abundance of thermodynamic data available. The model would also enable the generation of density data for slags containing Al2O3, CaO, FeO, MgO, MnO, and SiO2 compatible with the corresponding thermodynamic data.
Results of Research into the Segregation Behaviour of Manganese, Silicon and Chromium in Continuous Casting
Authors: Ilie Sergiu , Preßlinger Hubert , Reisinger Peter , Mayr Michael , Etzelsdorfer Kurt
Published: December 2016

For different steel grades the segregation factors of several alloying elements, both for crystal and for centre segregation, have been determined using electron probe microanalysis (EPMA). With this method two‐dimensional quantitative concentration images for several elements are assigned. The segregation factors depend on the chemical composition of a steel grade, in particular on its carbon content. Within a category of steel grades, the segregation factor will increase with increasing carbon content. For the first time, a large number of tests were performed on 53 slab samples from different steel grades to establish the segregation factors. The effects of the slab thickness, soft reduction and carbon content on crystal and centre segregation have been investigated. The results are essential for modelling the segregation phenomena occurring at solidification.
Effect of Austempering on the Structures and Performances of Cast High Carbon Si‐Mn Steel
Authors: Fu Hanguang , Miao Yuehui , Chen Xiang , Qiao Bao
Published: December 2016

The effects of austempering on the microstructures and mechanical performances of cast high carbon silicon and manganese steel (HCSMS) containing 1.0 wt.%C‐2.5 wt.%Si‐1.5 wt.%Mn‐1.0 wt.%Cr‐0.5 wt.%Cu were studied. The test results show a plate‐like morphology of bainitic ferrite. Each plate of the ferrite is surrounded by a thin layer of retained austenite when the austempering temperature is low, whereas large blocky areas of retained austenite are observed when the temperature is higher. The amount of retained austenite in the bainitic structure increases with increasing isothermal quenching temperature. Austempering results in a significant improvement in the mechanical performances of HCSMS. The main effect of the austempering temperature on the mechanical performances is that hardness and strength are decreased and elongation, impact toughness and fracture toughness are increased with increasing temperature. Cast HCSMS has excellent comprehensive mechanical performance when austenized at 593K.
Interfacial Tension between CaO‐Al2O3 Slag and Iron Containing Nonmetal or Tramp Elements
Authors: Sun Haiping
Published: December 2016

The interfacial tension between CaO‐Al2O3 slag and iron was studied for the iron containing nonmetal or tramp elements. The sessile drop technique was used to measure interfacial tensions under argon atmosphere at 1853K. Oxygen in liquid iron markedly reduced the interfacial tension. This effect was taken into consideration when analysing the interfacial tension between the slag and Fe‐S, Fe‐C, Fe‐Sn, Fe‐Sb and Fe‐Cu alloys. When adding S, Sn, Sb, or Cu to the iron, the interfacial tension was observed to decrease while carbon had no significant effect.
Phase Equilibrium of the System CaO‐P2O5‐SiO2 between 1473 K and 1673 K
Authors: Matsu‐suye M. , Hasegawa M. , Fushi‐tani K. , Iwase M.
Published: December 2016

Phase equilibrium was investigated in the ternary system of CaO‐P2O5‐SiO2 at 1473K, 1573K and 1673K.
Optimal Mixing Effect of LF Bottom‐Blown Stirring by Two Nozzles
Authors: Chen Min , Wang Nan , Yao Yongkuan , Geng Jianlin , Xiong Kunxiang
Published: December 2016

The mixing behaviour in a 150t ladle furnace induced by two‐nozzle jetting was investigated on the basis of a water model simulation of 1:4. The effects of nozzle arrangements, including separation angle, radial position and asymmetry as well as tracer adding position, on the mixing time were studied. The most favourable mixing was achieved when the two nozzles were symmetrically arranged at half radii in the ladle, with 45° separation angle. The empirical relationship between the mixing time and stirring power intensity was established for two‐nozzle jetting based on the present experimental results. In addition, the swelling above the bath surface was also investigated with the two‐nozzle jetting.
Volume Changes of Iron Oxide Compacts under Isothermal Reduction Conditions
Authors: Mousa El‐Sayed A. , Omar Adel A. , Nasr Mahmoud I. , El‐Geassy Abdel‐Hady A.
Published: December 2016

Compacts made from chemically grade Fe2O3 were fired at 1473K for 6 hrs. The fired compacts were isothermally reduced either by hydrogen or carbon monoxide at 1073–1373K. The O2 weight‐loss resulting from the reduction process was continuously recorded as a function of time using TGA technique, whereas the volume change at different reduction conditions was measured by displacement method. Porosity measurements, microscopic examination and X‐ray diffraction analysis were used to characterize the fired and reduced products. The rate of reduction at both the initial and final stages was increased with temperature. The reduction mechanism deduced from the correlations between apparent activation energy values, structure of partially reduced compacts and application of gas‐solid reaction models revealed the reduction rate (dr/dt) at both the initial and final stages. At early stages, the reduction was controlled by a combined effect of gaseous diffusion and interfacial chemical reaction mechanism, while at the final stages the interfacial chemical reaction was the rate determining step. In H2 reduction, maximum swelling (80%) was obtained at 1373K, which was attributed to the formation of metallic iron plates. In CO reduction, catastrophic swelling (255%) was obtained at 1198K due to the formation of metallic iron plates and whiskers.
On the Mechanism of Natural Convection and Equiaxed Structure during Dendritic Solidification Processes
Authors: El‐Bealy M. O. , Hammouda R. M.
Published: December 2016

A new technique has been developed to generate dendritic‐equiaxed structures in aluminium alloy casting processes, not only to improve the mechanical properties but also to study the effect of crystal structure on the chemical and physical properties of alloys to be cast. The investigation combined laboratory experimental work, metallographic examination and mathematic modelling. The laboratory experimental work involved different superheats for Al‐4.5%Cu alloy in cast ingots. Measurements of temperature distributions were conducted to verify the solidification model. A metallographic study combined macro and micro structural evolution of cast ingot samples. Two‐dimensional mathematical models of fluid flow and heat transfer were developed to characterise the natural convection streams and thermal fields. The model predictions were compared to temperature and isotherms measurements where a good agreement was found. The formation of cast structure and columnar, equiaxed transition (CET) and macro segregation phenomena were studied and discussed, based not only on the theories of nucleation but also on the thermal effects in the mushy and liquid zones.
Laboratory Investigations on Copper‐alloyed Interstitial Free Steel – Part II: Effect of Coiling Temperature
Authors: Rana Radhakanta , Bleck Wolfgang , Singh Shiv Brat , Mohanty Omkar Nath
Published: December 2016

The effect of coiling temperature on the annealing behaviour of copper‐alloyed interstitial free steel has been studied during batch and continuous annealing. The batch annealing kinetics undergoes a severe sluggishness in the so‐called industrial low temperature coiling condition, while retardation is less with high temperature coiling. The mechanism is believed to be the particle pinning effect exerted by peak‐aged or over‐aged copper precipitates. Room and high temperature coiled materials show similar strength and ductility after batch annealing. However, the texture development is different in the two cases, which leads to a variation in deep drawability. Copper precipitation has been observed to give rise to an unusual trend in strain hardening with the progress of batch annealing. The strength and formability parameters of the continuous annealed copper‐alloyed interstitial free steel do not depend on the coiling temperature due to dissolution of copper precipitates of the hot rolled material during continuous annealing. Irrespective of the coiling temperature continuous annealed copper‐alloyed interstitial free steels are as good as conventional interstitial free steels particularly in formability parameters.
Experimental Analysis on the Frictional Behaviour of Drawbeads in Sheet Metal Forming
Authors: Jang J.H. , Kim W.T. , Van Tyne C.J. , Moon Y.H.
Published: December 2016

In sheet metal forming, drawbeads are commonly used to control uneven material flow, which may cause defects such as wrinkles, fractures, surface distortion and springback. Although friction may not directly change the limiting strain of steel sheets, the tribological conditions in the contact zone between the sheet surface and the tool surface play an important role in determining the limits of the forming process. Friction in the drawbead contact zones affects the flow of the material in the tool and is used deliberately to control the stamping process. Therefore in this study, the frictional behaviour of drawbeads is experimentally investigated by the drawbead friction test. To characterize the effect of processing variables on the friction coefficients, tests are performed for various sheets, lubricants and bead materials suffering different surface treatments. The results obtained from the drawbead friction test show that the friction and drawing characteristics of deforming sheets were strongly influenced by the strength of sheet, viscosity of lubricant and hardness of bead surface.
Alternatives to Lead as a Machinability Enhancer in Free Cutting Steels
Authors: Reynolds Philip , Block Volker , Essel Ingo , Klocke Fritz
Published: December 2016

Low levels of lead are added to free cutting steels to improve machinability. For environmental reasons, there is interest in alternatives to lead that are technically and commercially viable. The machining performance of eight low carbon free cutting steels with alternative machinability enhancers, including additions of bismuth, increased sulphur (with and without tellurium), tin and phosphorus, has been investigated. In tests with high speed steel tools and lubricant, the leaded steel showed the best performance in terms of production rate, surface finish and chip form. In tests with coated carbide tools at a range of cutting speeds the standard non‐leaded 11 SMn30 steel performed well in terms of tool wear, but showed poorer chip form than the leaded steel. The steels with increased sulphur showed improved performance compared with the 11SMn30 steel in tests using high speed steel tools and lubricant, but did not approach the leaded steel in terms of production rate. The steels containing tin did not generally perform better than the 11 SMn30 steel. The 11 SMn30Bi steel gave performance approaching that of the leaded steel in tests with high speed steel tools and lubricant. However, the cost of this addition may make it uneconomic for large scale use.
Cold Work Hardening of High‐Strength Austenitic Steels
Authors: Gavriljuk V.G. , Tyshchenko A.I. , Bliznuk V.V. , Yakovleva I.L. , Riedner S. , Berns H.
Published: December 2016

Mechanisms of cold work hardening in three austenitic steels containing (mass%) 12Mn and 1.2C (Hadfield steel denoted as C1.2); 21Cr, 23Mn, 2Ni and 0.9N (Böhler steel P‐560 denoted as N0.9); 18Cr, 18Mn, 0.345C, 0.615N (CARNIT steel denoted as CN0.96) were studied using mechanical tension tests and TEM studies of substructure formed in the course of plastic deformation. Hadfield steel C1.2 reveals the smallest yield and ultimate stresses and elongation but the highest cold work hardening. Similar yield and ultimate stresses were obtained for steels N0.9 and CN0.96 with a higher elongation and cold work hardening for the latter. The analysis of TEM results leads to the following conclusions: Cold work hardening of the carbon steel C1.2 is mainly due to intensive twinning with rather thick twins. Localized planar slip is a feature of the substructure in the nitrogen steel N0.9 and carbon+nitrogen steel CN0.96 at strains up to 10 %, whereas twinning is involved in deformation at strains in the range of 10 to 50%. The strain‐induced ∊ martensite is rarely observed in both of these steels at strains above 30 %. The substructure and cold work hardening are discussed in terms of stacking fault energy, short‐range atomic order and binding between interstitial atoms and dislocations.
Sensitization Behaviour of Manganese‐Alloyed Austenitic Stainless Steels
Authors: Hochstrasser‐Kurz Sabine , Gümpel Paul , Arlt Norbert
Published: December 2016

Manganese is an essential alloying element in advanced austenitic stainless steels with specific properties such as high resistance to harsh corrosive environments, high strength or low material costs. These materials are often used for welded constructions which have to be highly corrosion resistant. Hence it has to be ensured that the heat input during welding does not initiate the precipitation of chromium carbide resulting in a susceptibility to intergranular corrosion. This leads to the question whether the sensitization behaviour of manganese‐alloyed austenitic stainless steels is comparable to that of the well‐known conventional chromium nickel austenites. In the present work the effect of heat‐input on the susceptibility of the CrNi‐steel 1.4301 and the CrNiMn‐steel 1.4376 to intergranular corrosion (IGC) was considered. Investigations were carried out by corrosion testing in the so‐called Strauss‐Test to elucidate the effect of the annealing temperatures on the microstructure. Furthermore, the influence of heat treatment on the mechanical properties was evaluated by tensile testing. As a result, it could be demonstrated that manganese‐alloyed austenitic stainless steels like grade 1.4376 exhibit a sensitization behaviour very similar to the conventional austenitic steel grades. The same kinds of tests on intergranular corrosion resistance can be applied for both types of materials.
Reduction of Solid Iron Oxide by Carbon
Authors: Moon II‐Joon , Jung Sung‐Mo
Published: December 2016

The reduction of pre‐reduced iron oxide by carbon was investigated from a kinetic viewpoint. The experimental procedure included thermogravimetric analysis to measure the weight change of the iron oxide pellet. The activation energy of the overall reaction was calculated to be 210 kJ/mol in the temperature range from 1273 to 1573 K. The overall reduction rate of FeO by carbon is believed to be mixed‐controlled by the Boudouard reaction and by the FeO reduction by CO gas in the temperature range investigated. The critical carbon concentration for the FeO reduction was estimated under the assumption that the activities of FeO and Fe are unity.
Electrochemical Measurements of Oxygen Potentials in the Slag System CaO‐P2O5‐SiO2‐FexO
Authors: Matsu‐suye M. , Fushi‐tani K. , Hasegawa M. , Iwase M.
Published: December 2016

The liquidus compositions of the four‐phase assemblages in the quaternary system of CaO‐P2O5‐SiO2‐FexO were determined at 1473 and 1573 K by employing electron probe microanalysis. Measurements were also made on the FexO activities at temperatures between 1373K and 1699K by employing an electrochemical technique involving stabilized zirconia electrolyte.
Aging Behaviour in Hot‐Rolled Low Carbon Steels
Authors: Chen J. K.
Published: December 2016

Lüders strain and aging index were employed to characterize the aging properties of hot rolled low carbon steels during production. The Lüders strain was found to increase with aging time while the aging index decreased. It is interpreted that the aging index represents the susceptibility of steels to aging, while the Lüders strain measures the effects of carbon and nitrogen atmosphere pinning on dislocations. By comparing accelerated aging with room temperature aging behaviours of low carbon steels for up to two years, an algorithm deriving the activation energy of solute carbon and nitrogen migration from aging property measurements was proposed. The equation derived for accelerated aging of hot‐rolled low carbon steels investigated was in reasonable agreement with that reported in the literature.
Heat Transfer during Multiple Jet Impingement on the Top Surface of Hot Rolled Steel Strip
Authors: Jondhale K.V. , Wells M.A. , Militzer M. , Prodanovic V.
Published: December 2016

Using a unique pilot facility a series of tests were conducted using three top jets to simulate the heat transfer that occurs during run‐out table (ROT) cooling. Steel samples instrumented with internal thermocouples were tested on this facility and the effect of top jet configuration (nozzle spacing of 40 to 115mm), and water flow rate (15 and 30 1/min) were quantified using moving plate samples. The multiple top jet work indicated that heat transfer across the plate width varies significantly and is high directly under the nozzle but decreases rapidly away from the nozzle in the interaction region. As cooling progresses a much larger wetted region occurs and more uniform cooling is experienced across the plate. Multiple jet cooling experiments have also confirmed that nozzle spacing does have an effect on heat transfer. This effect is predominate in the interaction region where closer nozzle spacing leads to enhanced and more uniform heat transfer in the lateral direction across the plate width away from the nozzle. As expected higher water flow rates led to higher heat transfer both under the nozzle and in the interaction region.
Local Use of Ageing Effects in Multiphase Steels for Designing Local Properties of Constructional Elements
Authors: Palkowski Heinz , Brück Anna
Published: December 2016

This paper describes processes leading to local bake hardening (BH) effects in multiphase steels. The investigations are part of a comprehensive project which investigates the influence of the deformation path and of the temperature and duration of thermal treatments on strengthening in modern multiphase steels, in regard to both local and bulk properties of steel structures. Dual phase (DP), retained austenite steels (TRIP) ‐ both hot and cold rolled ‐ and complex phase (CP) steel are investigated to examine the effect of thermomechanical processing parameters on local bake hardening ability. For this purpose two ways to achieve a local BH effect, i.e. local deformation and local heat treatment, are studied, as well as ageing stability of the adjusted strength. Hardness increased after local deformation through bending as result of work hardening and bake hardening effect. The local heat treatment leads to an improvement of mechanical properties (hardness and strength) and to local strengthening of material. The stability of the local bake hardening effect could be confirmed.
The Manufacture and Characterisation of Reinforced Magnesium Foams
Authors: Plorin Tillmann , Bormann Dirk , Bach Friedrich‐Wilhelm
Published: December 2016

In the project introduced here, the manufacture of light‐metal foams based on magnesium are investigated and enhanced. Such foams possess an excellent mass‐volume ratio and are therefore perfectly suited as light and effective reinforcing elements. Apart from other functional properties, their suitability as energy absorbing crash elements is to be particularly emphasised and is the focus of the investigations here. In the case of impact loading, the energy is largely transformed into the work of plastic deformation during a reduction in volume. Although metallic foams themselves possess only low absolute strengths, it is expedient to employ them in the form of material combinations like sandwich structures or composites by integrating additional internal reinforcing elements. The latter approach is pursued in the present project. Both the initial results of the feasibility study and also the metallographic and mechanical investigations for characterising reinforced magnesium foams are presented.
Manufacturing and Fatigue Strength of Brazed, Locally Hardened Structures
Authors: Schram Antonia , Masendorf Rainer , Medhurst Tim , Wiche Henning
Published: December 2016

The advantages of low‐heat joining, such as low distortion and no appreciable influence on the local material properties as a result of the low heat input, should be utilized for improving the reliability of processes for the manufacture of high‐strength structures. For this purpose, the mutual interactions among the parameters of the joining process, the brazing‐seam geometry, the brazing filler, the type of stress, and the fatigue strength, especially for arc‐brazed structures, are the subject of investigations for estimating the lifetime of locally hardened components by computational methods in the future. Fatigue life tests of brazed specimens show a significant increase of fatigue life compared to laser‐welded specimens. A further increase of fatigue life is expected by optimizing the geometry of the seam.
Production of Structure Components with Selective Properties by means of Action Media based Cold Forming
Authors: Behrens Bernd‐Arno , Hagen Thomas , Mielke Jens , Sidhu Kanwar Bir
Published: December 2016

Minimising a metallic component's weight can be achieved by either using lightweight alloys or by improving the component's properties. In both cases, the material formability affects the utilisability for mass production processes. Most of the high‐strength materials show a material‐restricted formability and are difficult to forge. The formability of a material is described by its maximum forming limit. Large plastic strains can lead to mechanical damage within the material. A promising approach of handling low ductile, high‐strength alloys in a forming process is deformation under superimposed hydrostatic pressure by active media. In the present study, the influence of superimposed hydrostatic pressure on the flow stress is analysed as well as the forming ability for different sample geometries at different hydrostatic pressure and temperature levels. The experimental results show that the superimposed pressure has no influence on the plastic deformation, nor does a pressure dependent near‐surface material hardening occur. Nevertheless, the formability is improved with increasing hydrostatic pressure. The relative gain at room temperature and increase in the superimposed pressure from 0 bar to 600 bar for tested materials was at least 140 % and max. 220 %. Therefore, a cold forming process under superimposed pressure is developed to produce structure components with selective properties. For example, the gain in formability will be used to enlarge local plastic strains to higher limits resulting in higher local strain hardening and hardness. This offers new design possibilities with selectively adjusted local structure or structure component properties, especially adapted to their technical application. Additionally, by applying damage models, finite‐element analysis is used in order to predict damage occurring in the cold forming process under superimposed hydrostatic pressure for various sample geometries.
Mathematical Modelling of Non‐equilibrium Decarburization Process during Vacuum Circulation Refining of Molten Steel: Application of the Model and Results (I) ‐ Decarburization Process and Influences of Some Technological Factors
Authors: Wei Ji‐He , Hu Han‐Tao
Published: December 2016

A novel three‐dimensional mathematical model proposed and developed for the non‐equilibrium decarburization process during the vacuum circulation (RH) refining of molten steel has been applied to the refining process of molten steel in a 90‐t multifunction RH degasser. The decarburization processes of molten steel in the degasser under the conditions of RH and RH‐KTB operations have been modelled and analysed, respectively, using the model. The results demonstrate that the changes in the carbon and oxygen contents of liquid steel with the treatment time during the RH and RH‐KTB refining processes can be precisely modelled and predicted by use of the model. The distribution patterns of the carbon and oxygen concentrations in the steel are governed by the flow characteristics of molten steel in the whole degasser. When the initial carbon concentration in the steel is higher than 400 · 10−4 mass%, the top oxygen blowing (KTB) operation can supply the oxygen lacking for the decarburization process, and accelerate the carbon removal, thus reaching a specified carbon level in a shorter time. Moreover, a lower oxygen content is attained at the decarburization endpoint. The average contributions at the up‐snorkel zone, the bath bulk and the free surface with the droplets in the vacuum vessel in the refining process are about 11, 46 and 42% of the overall amount of decarburization, respectively. The decarburization roles at the gas bubble‐molten steel interface in the up‐snorkel and the droplets in the vacuum vessel should not be ignored for the RH and RH‐KTB refining processes. For the refining process in the 90‐t RH degasser, a better efficiency of decarburization can be obtained using an argon blow rate of 417 I(STP)/min, and a further increase in the argon blowing rate cannot obviously improve the effectiveness in the RH refining process of molten steel under the conditions of the present work.
Mathematical Modelling of Non‐equilibrium Decarburization Process during Vacuum Circulation Refining of Molten Steel: Application of the Model and Results (II) ‐ Non‐equilibrium Factors and their Influences on the Decarburization Process
Authors: Wei Ji‐He , Hu Han‐Tao
Published: December 2016

The results, which were obtained by applying the novel three‐dimensional mathematical model proposed and developed earlier [1] to model and analyse the decarburization process of molten steel during the RH and RH‐KTB refining in a 90‐t multifunction RH degasser, showed that under the conditions of the present work, the contributions of the flow, mass diffusion and chemical reactions and other non‐equilibrium processes to the Raleigh‐Onsager dissipation function are not large throughout vacuum circulation refining of molten steel. Thus, it is held everywhere in the whole flow field of the system that the value of the non‐linear dissipation factor is approximately equal to one. The entropy generation and energy dissipation in the system rapidly decrease with increasing refining time. Compared to the work done by the drag force while the bubbles passing through the liquid phase as well as by the viscous and turbulent flow and diffusion processes, the carbon‐oxygen reaction itself plays a more governing role to the entropy production and energy dissipation in the system. The RH refining process of low and ultra‐low carbon steels seems to be close to the linear zone of the non‐equilibrium state. The influences of the viscous and turbulent flow dissipation as well as diffusion processes on the non‐equilibrium activity coefficients of the carbon and oxygen in the molten steel may almost be neglected. Except in the regions where the chemical C‐O reaction takes place (the up‐snorkel zone and the bath in the vacuum vessel), the non‐equilibrium components of the non‐equilibrium activity coefficients of the carbon and oxygen in the molten steel at the other places in the degasser are all tending towards one. The non‐equilibrium effects (mainly, the C‐O reaction itself) give a restraining role on the decarburization of liquid steel in the RH refining process. This model is able to model more reasonably and precisely the non‐equilibrium decarburization process during the vacuum circulation refining of molten steel in comparison to a model without considering the non‐equilibrium effects.
The Effect of Ladle Treatment on Inclusion Composition in Tool Steel Production
Authors: Björklund Johan , Andersson Margareta , Nzotta Mselly , Jönsson Pär
Published: December 2016

An in‐depth SEM‐investigation of the inclusion composition change in the ladle refining process during tool steel production was done. Plant trials were carried out at Uddeholm Tooling AB in Hagfors, Sweden. A series of samples was taken during ladle refining, from deslagging through vacuum treatment. The goal was evaluating the effects of the top slag and other process parameters on the inclusion composition during ladle refining. The main conclusion was that normal variations in the process have a large influence on inclusion composition. Furthermore, it was concluded that the MgO content in the top slag had a large influence on the inclusion composition throughout the whole ladle refining process. Also, the SiO2 content in the ladle slag originating from the EAF‐slag, had a noticeable effect on the inclusions. The inclusions belonging to the system Al2O3‐CaO‐MgO‐SiO2 showed a continuous composition change throughout the ladle refining process, from high Al2O3, via MgO‐spinel to finally complex types rich in CaO and Al2O3.
Effects of Process Parameters prior to Annealing on the Formability of Two Cold Rolled Dual Phase Steels
Authors: Granbom Ylva
Published: December 2016

This study concerns the effects of coiling temperature after hot rolling and the degree of reduction during cold rolling on formability‐related properties of high strength cold rolled dual phase (DP) steels. The effect of coiling temperature on the final structure and properties of two cold rolled and annealed DP‐steels is investigated. Further, the effect of cold rolling reduction and its impact on the final properties of the material is studied. Aspects of the impact of the different process parameters on the ferrite to austenite and austenite to martensite transformation are discussed based on results from production scale experiments, tensile testing and metallographic examinations of the materials.
Improvement of the Shape Memory Effect in Fe‐based Alloys by Training
Authors: Van Caenegem Nele , Verbeken Kim , Segers Danny , Houbaert Yvan
Published: December 2016

Shape recovery in iron‐based shape memory alloys is known to be incomplete. Thermomechanical cycling or training is recognized to improve the shape memory effect. In the present work, different aspects of training are studied: the number of cycles, the amount of deformation and the annealing temperature. As the number of cycles increases, the ∊ martensite plates become thinner and within the different grains they tend to align in the same direction. Still, different variants are present. XRD measurements showed a strong increase in the ∊ martensite volume from cycle 1 to cycle 2 and a slight decrease for further cycles. There exists an optimum deformation for obtaining stress induced ∊ martensite which is reversibly transformable to austenite during annealing. When the amount of deformation is too low, the fraction of stress induced ∊ martensite is very low, therefore, the shape memory effect is small. If the deformation is too large, slip may occur and different ∊ martensite variants are formed, which hinders the reverse ∊→γ transformation. The recovery annealing temperature is critical for obtaining a good shape memory, especially during training. The recovery annealing temperature of 400°C is too low for completing the reverse transformation; annealing at 600°C is most commonly used.
Common Mental Health Issues
Authors: Stock Susan R. , Levine Heidi
Published: December 2016

This chapter provides an overview of common student mental health issues and approaches for student affairs practitioners who are working with students with mental illness, and ways to support the overall mental health of students on campus.
Mental Health Aspects of Responding to Campus Crises
Authors: Flynn Christopher , Sharma Micky M.
Published: December 2016

Tragedy can strike a college campus in unpredictable and often horrific ways that may lead to traumatic responses for individuals and the entire campus community. Crises on campus demand an appropriate response to support the community, provide assistance to affected individuals and guide healing efforts.
Promoting Resilience, Retention, and Mental Health
Authors: Eisenberg Daniel , Lipson Sarah Ketchen , Posselt Julie
Published: December 2016

This chapter describes why resilience and mental health deserve more attention in efforts to increase student retention. The chapter offers practical suggestions for campus administrators and others.
An efficient exact numerical solution for scattering by a circular cylinder
Authors: Zhu Chunhui , Liu Lijun , Song Zhengyong , Liu Yanhui , Liu Qing Huo
Published: December 2016

An efficient and exact spectral integral method (SIM) for the general problems of scattering by a circular cylinder is presented, both for acoustic and electromagnetic cases. Fast Fourier transform (FFT) and convolution theorem help us to execute the algorithm efficiently with computational complexity. The Fourier coefficients of the integral kernels are computed in a semianalytical way to accomplish a fast convergence rate with spectral accuracy. Compared with the method not using the semianalytical forms, without the increase of the computing and memory abundance, it saves more than 90% sampling points to achieve about the same accuracy, and with the same number of sampling points, several to more than ten orders of magnitude more accuracy can be achieved. For example, for the tested large wavenumber case with 2 × 106 wavelengths on the boundary, only two sampling points per wavelength are required to achieve a relative error of less than 0.001%. More than 90% computational time is saved compared with the normal summation formula of harmonic cylinder expansions. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Electromagnetic‐circuit co‐simulation of very fast transient overvoltage in gas‐insulated switches
Authors: Liu Ying , Chao Hsuehyung , Xie Yongjun , Wu Dongwei
Published: December 2016

The very fast transient overvoltage (VFTO) originating from operations of an isolating switch in a gas‐insulated switch (GIS) will cause dangerous interference to the switch and its peripherals. Aiming at the engineering issue, a collaborative simulation method by field‐circuit‐wave of VFTO radiation interference is proposed in this paper. With a combination of project cases, the GIS equivalent circuit is first extracted by means of quasistatic electromagnetic (EM) field analysis. Furthermore, the equivalent time‐varying voltage source of VFTO is obtained by associating the time‐varying resistance model of the switching arc and the broadband circuit method. Finally, using the transient full‐wave technique in the time domain, the spatial EM interference by VFTO is simulated. It turns out that this method has high significance to the high‐voltage switch design. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Visual‐based and object‐conscious image retrieval by block reallocation into object region
Authors: Mochizuki Takahiro , Kawai Yoshihiko , Sano Masanori , Sumiyoshi Hideki , Fujii Mahito
Published: December 2016

‘Visual‐based’ image retrieval based on the visual similarities over the entire image is one of the powerful and useful ways when targeting large volume content with inadequate annotation. Generally, conventional methods divide a query image and target images in the database into grid‐shaped blocks and calculate the similarity based on image features by comparing each corresponding block straightforwardly. However, the method sometimes fails in terms of object‐conscious retrieval when their backgrounds are almost the same but the only the object is different or the object's size and/or position is different. To solve the problem, we propose a new method featuring the reallocation of some blocks to the object region (OB‐blocks) and a new similarity score by placing a weight on the OB‐blocks, which are derived from the visual saliency map. Our proposed method could realize ‘visual‐based and object‐conscious’ image retrieval. We verify the effectiveness of this method through comparison experiments. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Estimation of the disaster building domain using RapidEye data to estimate the amount of disaster waste
Authors: Shirai Hikaru , Kageyama Yoichi , Ohuchi Azuma , Nishida Makoto
Published: December 2016

To draw reconstruction plans following major earthquakes, such as the Great East Japan Earthquake of 2011, it is necessary to quickly estimate the amount of disaster waste. To this end, remote sensing data is used, which affects all subsequent processing. However, the digital number of each pixel of the remote sensing data represents the average land cover conditions. That is, the information provided by a pixel should be represented as a one‐pixel mixed class (‘mixel’) instead of a one‐pixel single class. In previous papers, we had proposed a method of land cover classification using Thailand Earth Observation System data of a stricken area. The land cover classification results were in good agreement with a manually classified map which referenced the geological map and aerial photograph. However, to detect collapsed buildings, a minimum 2‐m ground resolution is required. Therefore, we additionally proposed a method of land cover classification using RapidEye data. The ground resolution of RapidEye data was improved to 2‐m from 6.5‐m by the proposed method. These examination results suggested that the method is effective in the classification of land cover conditions using RapidEye data. Nevertheless, the disaster building domain was not yet estimated. In this paper, we therefore propose a method to estimate the disaster building domain using RapidEye data acquired before and after an earthquake. The effectiveness of this method is confirmed by evaluation results. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Design and research of a three‐phase voltage sensor based on D‐dot principle
Authors: Wang Jingang , Fan Yuyi , Zhu Liyun , Bai Yunjie
Published: December 2016

In the design of three‐phase D‐dot voltage sensor based on electric field coupling, both effects of both the adjacent phase electric fields and distribution parameters on measurement should be taken into consideration. This paper builds a simulation model and a physical measuring system of a three‐phase sensor, measures the effect of the distribution parameters by the simulation model, and finally finds the transfer function between the input and output voltage signals of the circuit. The measured voltage waveforms and parameters can be reflected by the physical measuring system. Our results provide a theoretical basis for the design of a three‐phase D‐dot voltage sensor. And the measuring system can achieve multipoint synchronous acquisition and ensure less distortion. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Constrained MPC to track time‐varying reference signals: Online optimization of virtual reference signals and controller states
Authors: Wada Nobutaka , Tsurushima Seiya
Published: December 2016

In this paper, we propose a model predictive control (MPC) algorithm for linear systems with constraints to track time‐varying reference signals. The proposed controller is assumed to have an integrator as a servo compensator. In the proposed control approach, the value of the integrator state is optimally initialized at each sampling time to improve tracking control performance until the cost function becomes sufficiently small. Moreover, while the cost function is sufficiently small, the integral action is used to achieve offset‐free tracking. The control algorithm is reduced to a convex optimization problem with linear matrix inequality constraints. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Prediction of the appearance of monkeys based on environmental conditions
Authors: Nakai Kazufumi , Ezaki Nobuo , Sugiura Akihiko
Published: December 2016

Recently, agricultural damage caused by monkeys has become a critical problem in Japan. This paper proposes a system that predicts the dates and times at which monkeys approach farmland. In order to make predictions, monkeys were made to wear collars with transmitters, and the trend data of the monkeys' distances were collected by receivers in the system. Two years after this system was installed around a mountain, an average radio communication ability of 97.22% was obtained, and 25 million monkey signals were received. The time of appearance of the monkeys according to those signals as well as the environmental conditions were taken for estimation. Bayesian estimation and support vector machine (SVM) were adopted as linear and nonlinear methods, respectively. The use of Bayesian estimation resulted in little predictive effect. SVM, on the other hand, achieved 31% accuracy by combining two learning pattern methods, outperforming the Bayesian estimation and confirming the effectiveness of environmental conditions in a system of predicting the appearance of monkeys. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Transformable device that can switch between rigid body and soft body
Authors: Nishikawa Yuto , Matsumoto Mitsuharu
Published: December 2016

The materials for transformable robots can roughly be categorized into two types, that is, rigid body and soft body. They have different features, and have merits and demerits, respectively. Robots with rigid body have high stiffness, and are suitable for carrying and holding objects. However, they may injure users if they make contact. Robots with soft body have high flexibility and can make contact safely. However, they have difficulty in retaining particular shapes and are fragile against external force. In this letter, we propose some devices that can switch between rigid body and soft body using phase change of low melting alloy to resolve the problems. We also provide some experimental results with the device to clarify the applicability of the developed devices. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
The Use of Segment Information by Financial Analysts and Forecast Accuracy: A Study on European Intermediate‐Size Companies
Authors: Demerens Frédéric , Delvaille Pascale , Manh Anne Le , Paré Jean‐Louis
Published: December 2016

This research investigates the usefulness for financial analysts of segment information disclosed by European intermediate‐size companies reporting under IFRS. While most studies on segment information usefulness focus on the consensus aggregated from financial analysts’ forecasts for blue‐chip companies, our study contributes to the literature by investigating the recommendation reports of financial analysts covering European intermediate‐size companies. The study is based on an original, hand‐collected database obtained from a sample of 339 analysts’ recommendation reports for 146 firms. Our research reveals that though a majority of analysts refer to segment information in their reports, only a few of them use it in their valuation models. Moreover, it also demonstrates that the use of segment information by financial analysts is higher for larger firms than for smaller ones and is not associated with greater forecast accuracy. Hence, our results question the usefulness of segment information disclosures for small firms. © 2016 Wiley Periodicals, Inc.
Collaborative Structures in a Graduate Program
Authors: Otty Robyn , Milton Lauren
Published: December 2016

This chapter describes the Centralized Service Learning Model (CSLM), a collaborative‐teaching structure that connects two separate courses with one service‐learning project. We discuss the lessons learned from applying the CSLM in our courses.
Re: Relationship between general movements in neonates who were growth restricted in utero and prenatal Doppler flow patterns. J. C. Tanis, D. M. Schmitz, M. R. Boelen, L. Casarella, P. P. van den Berg, C. M. Bilardo and A. F. Bos. Ultrasound Obstet Gynecol 2016; 48: 772–778.
Authors: Sanz Cortes M.
Published: December 2016

Linked Comment: Ultrasound Obstet Gynecol 2016; 48: 772–778
The break-up of free films pulled out of a pure liquid bath
Authors: Champougny Lorène , Rio Emmanuelle , Restagno Frédéric , Scheid Benoit
Published: December 2016

In this paper, we derive a lubrication model to describe the non-stationary free liquid film that is created when a vertical frame is pulled out of a liquid reservoir at a given velocity. We here focus on the case of a pure liquid, corresponding to a stress-free boundary condition at the liquid/air interfaces of the film, and thus employ an essentially extensional description of the flow. Taking into account van der Waals interactions between the interfaces, we observe that film rupture is well defined in time as well as in space, which allows us to compute the critical thickness and the film height at the moment of rupture. The theoretical predictions of the model turn out to be in quantitative agreement with experimental measurements of the break-up height of silicone oil films in a wide range of pulling velocities and supporting fibre diameters.
Numerical Assessment of Rectangular Straight/Reverse Mufflers at High-Order-Modes
Authors: Chang Y. C. , Lin D. Y. , Cheng H. C. , Chiu M. C.
Published: December 2016

There has been wide-spread use of plane wave theory in muffler design in industry. However, This has led to an underestimation of acoustical performances at higher frequencies. To overcome the above drawback, the finite element and boundary element methods have been developed. Nevertheless, the time consumed in calculating the noise level is unacceptable. Moreover, considering the acoustical effect and necessity of space-constrained situation in industry, a compact design of reverse mufflers which may improve the acoustical efficiency is then proposed.

In this paper, a numerical assessment of rectangular mufflers hybridized with straight/reverse chambers using eigen function, four-pole matrix, and genetic algorithm under limited space is developed. Before the optimization is performed, an accuracy check of the mathematical models for the muffler will be carried out. Results reveal that the noise reduction will increase when the number of chambers increases. In addition, the acoustical performance of the mufflers is reversely proportional to the diameter of the inlet/outlet tubes. Also, the TL of the mufflers will be improved when using more number of target tones in the objective function. Consequently, a successful approach in searching optimal shaped rectangular straight/reverse mufflers using an eigen function and a genetic algorithm method within a constrained space has been demonstrated.