bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long‐term cottonwood establishment along the Green River, Utah, USA
Authors: Scott M. L. , Miller M. E. 
Published: December 2016

AbstractCottonwood (Populus spp.) riparian forest and woodlands provide valuable ecological goods and services, especially in arid and semiarid regions of North America. Successful establishment and survival for cottonwoods requires bare, moist alluvium that is relatively safe from fluvial disturbance. These are restrictive requirements in dry regions. Cottonwoods can survive for three to four centuries and thus may provide a long‐term record of specific fluvial and geomorphic events. We used C14 analysis and ring counts of cottonwood stems to document a long‐term record of cottonwood establishment. We related this record to the century‐long gage record at Green River, Utah along with historical photos and paleoflood records. Radiometric carbon dating and ring counts suggest some cottonwood stems established on high alluvial deposits following large floods as early as the late 1600s through the late 1800s. Cottonwoods also established on inset floodplain surfaces following sustained decreases in peak flows resulting from climatic drought and the closing of Flaming Gorge Dam. Finally, establishment occurred on both higher post‐dam flood deposits as well as low, active channel surfaces following floods and during a series of low flow years. With continued peak‐flow reduction, cottonwood recruitment will likely be restricted to spatially limited, lower elevation surfaces and subjected to competition from an array of herbaceous and woody riparian species.
On the “Where” of Social Experiments: Selecting More Representative Samples to Inform Policy
Authors: Olsen Robert B. , Orr Larry L. 
Published: December 2016

AbstractMost social experiments are conducted in samples of sites that are not formally representative of the population of policy interest. These studies may produce impact estimates that are unbiased for the sample but biased for the population from which the sample was selected. Recent research has estimated the bias associated with nonrandom inclusion. Although some research has focused on solutions to the problem at the design stage or the analysis stage, research on ways to address this problem is still sparse. This paper provides four recommendations to help researchers obtain more representative samples in impact studies. The fundamental challenge is that, in most impact studies, sites are not required to participate if selected. Therefore, obtaining a sample that adequately represents the population of policy interest can be difficult, and the resulting impact estimates may suffer from external validity bias. The recommendations in this chapter address this challenge to help researchers obtain more representative samples when obtaining a perfectly representative sample is not possible. The recommendations, which are based on standard survey sampling methods, demonstrate that researchers can take practical steps to obtain impact estimates that are more generalizable from the study sample to the broader population of policy interest—and therefore more relevant for informing policy decisions.
Building work engagement: A systematic review and meta‐analysis investigating the effectiveness of work engagement interventions
Authors: Knight Caroline , Patterson Malcolm , Dawson Jeremy 
Published: December 2016

SummaryLow work engagement may contribute towards decreased well‐being and work performance. Evaluating, boosting and sustaining work engagement are therefore of interest to many organisations. However, the evidence on which to base interventions has not yet been synthesised. A systematic review with meta‐analysis was conducted to assess the evidence for the effectiveness of work engagement interventions. A systematic literature search identified controlled workplace interventions employing a validated measure of work engagement. Most used the Utrecht Work Engagement Scale (UWES). Studies containing the relevant quantitative data underwent random‐effects meta‐analyses. Results were assessed for homogeneity, systematic sampling error, publication bias and quality. Twenty studies met the inclusion criteria and were categorised into four types of interventions: (i) personal resource building; (ii) job resource building; (iii) leadership training; and (iv) health promotion. The overall effect on work engagement was small, but positive, k = 14, Hedges g = 0.29, 95%‐CI = 0.12–0.46. Moderator analyses revealed a significant result for intervention style, with a medium to large effect for group interventions. Heterogeneity between the studies was high, and the success of implementation varied. More studies are needed, and researchers are encouraged to collaborate closely with organisations to design interventions appropriate to individual contexts and settings, and include evaluations of intervention implementation. © 2016 The Authors. Journal of Organizational Behavior published by John Wiley & Sons, Ltd.
Grundlagen des Thermocoil‐Verfahrens zur Herstellung höherfester Betonstähle auf Drahtwalzanlagen
Authors: Brennecke Norbert , Günther Ernst 
Published: December 2016

Die anlagentechnischen und technologischen Bedingungen von modernen Drahtwalzanlagen bieten besondere Möglichkeiten zur Herstellung von höherfesten Betonstählen durch thermomechanische Behandlung. Vorverformungen in der Vor‐ und Mittelstaffel und die hohe und schnelle Endumformung im Drahtblock führen zu einem sehr feinkörnigem Austenitgefüge am Ende des Umformprozesses, das durch eine auf die chemische Zusammensetzung des Stahles abgestimmte Druckwasserkühlung im Anschluß an den Walzprozeß in ein entsprechend feinkörniges Sekundärgefüge, gegebenenfalls kombiniert mit einer partiellen Vergütung (Vergütung der Randzone), umgewandelt werden kann.Die zeitliche Veränderung der Temperaturverteilung über den Querschnitt im Verlauf der Druckwasserkühlung und des nachfolgenden Temperaturausgleichs an Luft läßt sich mit geeigneten mathematischen Modellen berechnen, so daß aus den bekannten Zusammenhängen zwischen Eigenschaften, Struktur und Abkühlbedingungen die anlagentechnischen Parameter für die thermomechanische Behandlung von Betonstählen auf Drahtwalzanlagen rechnerisch ermittelt werden können. Die Beherrschung der beim Durchlauf durch die Wasserkühlstrecke auf den Walzdraht wirkenden Bremskräfte erfordert eine spezielle Technologie für den Betrieb der Drahttreiber.
Application of numerical techniques to the analysis of strains in the drawing process
Authors: Sadok Lucjan , Paćko Marek 
Published: December 2016

For two variants of the drawing process of solid round profiles (α = 6°C, RO/Rk = 1.136, m = 0.15 and α = 4°C, RO/Rk = 1.192, m = 0.15) the effective strain distribution εj and the coordinate grid distortion are presented and compared. The results presented have been obtained theoretically using FEM and experimentally by means of the coordinate grid method. Based on the programme which simulates the drawing process of solid round profiles the distribution of the ε̇rz strain‐rate tensor component, the effective strainrate εj and the die pressure distributions on the metal‐die contact surface were presented. Exact description of the experiments carried out has also been presented. Investigations of strain distribution were done on copper specimens. Results were presented as three dimensional graphs. This helps to make a detailed analysis of changes occurring in the deformation zone for some of the quantities considered. Comparing effective strain distribution εj and grid distortions it follows that experimental data agree with theoretical calculations. Differences occur after the metal exits from the die.The presented results of theoretical considerations and experimental investigations help to state that the programme constructed, while based on the FEM, simulated the drawing process of solid round profiles accurately.
Modellmäßige Beschreibung des Temperaturfeldes eines Sinterprozesses
Authors: Streich Eckart , Hesse Bodo , Gudenau Heinrich‐Wilhelm 
Published: December 2016

Im Rahmen einer Dissertation stellte sich die Aufgabe, die Partikelfiltration in einem Sinterprozeß modellmäßig zu beschreiben, der von Sinterabgas durchströmt wird. Dazu wurde ein Modell des Temperaturfeldes im Sinterprozeß entwickelt. Die Beschreibung dieses Temperaturmodells wird in dieser Arbeit ausführlicher als in der Dissertation dargestellt.Ausgehend von der Differentialgleichung für den Wärmetransport wird mit vorgegebenen, idealisierenden Modellannahmen eine analytische Lösung gefunden, mit der der örtliche und zeitliche Temperaturverlauf des Sinterprozesses berechnet werden kann. Beim Vergleich von gemessenen Temperaturdaten und berechneten Modellwerten wird eine gute Übereinstimmung festgestellt. Neben der Überprüfung von Parametereinflüssen ist das Modell auch zur Überprüfung von numerischen Modellansätzen geeignet.
Measurement of viscosity, density and surface tension of metal melts
Authors: Friedrichs Hans Adolf , Ronkow Leonid Wladimirowitsch , Zhou Yongmao 
Published: December 2016

A modified procedure for measuring viscosity, surface tension and density of metallic melts, using a gas bubble viscosimeter, is presented. The principle of measurement is based on the relation between rate of ascent of a gas bubble in the melt and the melt viscosity. The rate of bubble ascent is determined by registering the moment of detachment by pressure measurement in the lance and the moment of arrival of the bubble at the melt surface by video film and an image processing system.The procedure is tested and the limits of its application are determined by comparative measurements on reference metals.After tests on reference metals, measurements are taken of the viscosity, density and surface tension of Al‐Cu alloys in the temperature range 960 – 1465 K with copper contents of 12.23 to 58.5%. The relationships between these values and temperature and composition of the melt are investigated, and corresponding approximation formulae derived.
Low carbon manganese steels microalloyed with vanadium and nitrogen
Authors: Eissa Mamdouh , EI‐Fawakhry Kamal , Mekkawy Mohamed , Hussein Abdul Hamid , Tawfik Ahmed 
Published: December 2016

With the objective of studying the effect of vanadium and nitrogen microalloying on microstructure and strength of low carbon steels with different manganese contents, three series of low carbon steels (0.1% C) with manganese content (between 0.8 and 3.5%), vanadium content (up to 0.17%) and nitrogen content (up to 0.025%) have been designed and investigated in the hot forging condition using a preheating and finish forging temperatures of 1200 and 950°C, respectively.Steels with a manganese content up to 2.3% revealed ferrite‐pearlite structures, whereas higher manganese contents from 2.7 to 3.5% resulted in the formation of bainitic structures. A pronounced effect of manganese on the mechanical properties of steels was detected at lower manganese contents < 1.5%, due to solid solution and grain refining effects, and higher manganese contents > 2.3, due to bainite formation. Manganese content in the range of 1.5‐2.3% had less pronounced effect due to solely solid solution hardening.Vanadium microalloying effectively increased the strength of steels through solely precipitation strengthening or both precipitation strengthening and grain refining effect. The effectiveness of vanadium was greatly enhanced by increasing the nitrogen content. The grain refinement of vanadium‐nitrogen microalloying seems to be due to inhibition of austenite grain growth as a result of precipitation of vanadium nitride in austenite during forging. Precipitation strengthening of these steels is achieved by precipitation of vanadium carbide and nitride in ferrite or bainite.Nitrogen enhanced the precipitation strengthening of vanadium microalloyed steels which could be attributed to the finer vanadium nitride dispersion precipitates compared with vanadium carbide. Up to 70% of the total nitrogen content of steel precipitates as vanadium nitride which could be achieved with V/N ratio of about 6‐7.Microalloying of low carbon‐manganese steels (0.1% C and 1.8% Mn) with 0.15% vanadium and 0.025% nitrogen was found to be effective in attaining high levels of yield and ultimate tensile strengths of 835 and 940 N/mm2, respectively in the forging condition.
Thermodynamic properties of alumina‐saturated iron‐carbon‐bismuth alloys
Authors: Chang Lewen , Malhotra Sandeep , Schlesinger Mark E. 
Published: December 2016

Using direct and indirect equilibration methods, the solubilities of iron in molten bismuth and those of bismuth in molten iron‐carbon alloys have been measured over the temperature range 1473‐1873 K. The Henrian behaviour of bismuth in molten ferrous alloys allows the calculation of its activity coefficient, which in turn facilitates modelling as a function of temperature and carbon content, using the unified interaction parameter formalism developed by Pelton and Bale. The modelling results generate the expression: .A model has also been developed expressing bismuth content in molten iron‐carbon alloys as a function of temperature and composition: .
Development of new deep drawing steels by doping with surface active elements
Authors: Beyer Gerhard H. , Grabke Hans Jürgen 
Published: December 2016

In this study, the effects of doping with the surface‐active elements Ge, Te, Se, As, Sb and Sn in atomic mass contents of 10 to 200 ppm on the texture and drawability of an IF‐steel (FeP06, DIN‐EN 10130) and an ELC‐steel (FeP05, DIN‐EN 10130) were investigated. Twenty‐six ingots were produced by melting and doping in a vacuum‐induction furnace, followed by forging, hot‐rolling and cold‐rolling. The cold‐rolling reduction was ɛ = 72 %. Recrystallization annealing was performed in a batch‐annealing simulation furnace. Subsequently, the orientation distribution function (ODF) and the α, γ, η‐fibre textures of both the cold‐rolled and recrystallized state were measured by means of an X‐ray diffraction goniometer and compared with the undoped reference material.The results indicate that the IF‐steel specimens doped with 100 ppm Te and Se show a significantly enhanced γ‐fibre {111}<110>‐{111}<112> texture compared to the reference specimen. Also the ELC‐steel specimens showed a higher γ‐fibre by doping with atomic mass contents of 10 to 100 ppm Se and Te. To investigate whether the drawability has been improved, Lankford‐value (rm and Δr) measurements by means of tensile tests were applied. The compositions with improved γ‐fibre also showed higher r‐values and therefore confirmed the results of the texture measurements. Se doping was found to be especially beneficial in texture and drawability for both investigated materials. The growth of selenides and tellurides at the surface of Ti4C2S2‐ and Ti2S‐ precipitates was observed by means of scanning transmission electron microscope linescans equipped with field emission gun (STEM‐FEG). Doping with Sb and Sn rendered no notable improvement of the materials, and Ge and As proved to affect the mechanical properties unfavourably.
The temperature equilibrium during hot tensile tests of stainless steels
Authors: Lin Dong‐Yih , Dahl Winfried 
Published: December 2016

Real temperature equilibrium within specimens is the basis of reliable results of hot tensile tests. These tests were undertaken with cylindrical specimens of a ferritic stainless steel AISI 430 and an austenitic stainless steel AISI 304. The specimens with diameters of 10, 15, 20 and 25 mm were partially melted. The cooling rates after holding by a maximum temperature varied between 0.5 and 3.0 K/s. Temperature was measured continuously at the specimen center and 3 mm under the specimen surface during the whole test process.Tests with the smallest specimen diameter and under a slow cooling rate of 0.5 K/s had even temperature distribution in the radial direction of the specimen so that no duration time is required at any test temperature. Such identical temperature distribution in the cross‐section of specimens were changed in different ranges when the specimen diameter was enlarged or the cooling rate was increased. The necessary duration time for the temperature equilibrium in the radial direction of specimens is explained in detail in this study that can help the reliability of hot tensile test.
Reduction of MnO from molten slags with liquid steel of high carbon content
Authors: Vargas‐Ramirez Marissa , Romero‐Serrano Antonio , Chavez‐Alcala Federico , Zeifert Beatriz , Hallen‐Lopez Manuel 
Published: December 2016

This work estimated the reduction of MnO in slags of the CaO‐SiO2‐FeO‐CaF2‐MnO system and liquid steel with the initial composition (mass contents) 0.75 %Mn, 0.16 % Si and 0.5 to 2.0 % C, as an alternative to introducing Mn to the steel melt. The slag basicities (CaO/SiO2) In the experiments were 2 and 3. MnO was obtained from manganese ore. The experiments were carried out in an open 10 kg induction furnace using Al2O3‐based refractory at 1873 K. The oxygen potential was measured throughout the experiments with a galvanic cell (ZrO2‐solid electrolyte with a Cr/Cr2O3 reference electrode).The MnO reaction mechanism was analysed in terms of the slag basicity, the silicon and the initial carbon contents in the melt. The rate and the degree of MnO reduction were found to increase with the increasing of initial carbon content; however, the effect of slag basicity was less important. A kinetic analysis of the process was performed using a coupled reaction model.
Quantitative assessment of segregates in continuously cast slabs by electron probe microanalysis
Authors: Preßlinger Hubert , Mayr Michael , Kaltenbrunner Thomas , Lettner Josef 
Published: December 2016

Due to the limited solubility of individual elements in the crystal lattice of steel, an enrichment of the residual melt and furthermore a formation of micro and macro segregates will appear during solidification of the steel melt. Depending on the chemical composition of the steel, the operation parameters of the casting plant and the slab dimension, the segregates will be formed with different intensities. The knowledge of the segregation effects is imperative for further processing of slabs and the subsequent products.The electron probe micro analyser (EPMA) makes feasible an objective assessment of the segregates due to solidification over the entire slab thickness. This is carried out by concentration mapping (CM), which is a method for the quantitative determination of element distributions over certain areas on the sample. In this paper some results taken from an investigation on steel grade 13 CrMo 4–5 are presented, and some casting technological measures derived from these results are proposed.
Steel Desulphurisation and Sulphur Bonding in Solidified Ladle Slags
Authors: Posch Wilhelm , Preßlinger Hubert , Mayr Michael , Klepp Kurt O. , Hiebler Herbert 
Published: December 2016

It was investigated in which form sulphur is bonded in ladle slags. For this purpose, the mineralogical phases of the ladle slags were qualitatively and quantitatively evaluated by means of a microprobe. This slag characterisation allowed reconstructing the bonding of sulphur into the phases of the ladle slag. Moreover, the reaction process with regard to the ionic theory as well as the structural formula for the mechanism of sulphur bonding were discussed.The bonding of sulphur into calcium aluminate slags is determined by the sulphide ion content in the slag as well as by the ratio of (CaO)/(Al2O3). Calcium sulphide separates only if the slag contains a large number of sulphide ions. When Ca12Al14O33 is separated the sulphide ion is successively integrated into the lattice. The crystal lattice of Ca12Al14O33 is characterised by an open, three‐dimensional anionic network composed of aluminium‐oxygen tetrahedrons linking the edges. In this network, large interstitial spaces are formed, which may be filled with calcium ions on the one hand and statistically with a free oxygen or sulphide ion on the other hand.
Review of ECSC research work in ironmaking
Authors: Mülheims Klaus , Peters Michael , Lüngen Hans Bodo 
Published: December 2016

The Treaty of the European Coal and Steel Community (ECSC), which expired in 2002, states in its Article 55 to promote technical and economic research with respect to the production and growing application of coal and steel. The results of funded research projects shall be made available to all representatives and partners concerned. For the European steel industry Article 55 was the basis for building up a steel research programme covering topics from raw materials to steel application and instigated a European network of researchers from the steel industry, research institutes and universities.On the basis of these research and development activities carried out by the ECSC steel research, the iron and steel industry has shown important advances in technology and environmental compatibility. Furthermore, the ECSC steel research has contributed to nearly all important technological developments. The main objective of the ECSC steel Research and Technology Development (RTD) programme was to sustain and develop the Community steel industry's competitiveness.The following report describes fundamental developments and activities within the framework of ECSC research with particular respect to hot metal production in the last 15 years.
Interfacial Convection and Mass Transport in Thin Liquid Layer
Authors: Scheller Piotr R. 
Published: December 2016

Investigations into the phenomenology of convection flows next to the interface between two liquids have been carried out in laboratory experiments using various liquids. Then convection flows have been observed in industrial tests during continuous casting. The results show that the motional velocity of volume elements next to the interface due to disturbances of interfacial tension (produced by mass and charge transfer) depends on liquid layer thickness and on liquid properties. A new dimensionless number is introduced to describe this manner of convective flow; it is also suitable for evaluation of experimental results. Furthermore, a dimensionless function is theoretically developed to describe the relation between convective flows near the interface in the slag layer and mass transport.Casting powders melt on the surface of the liquid metal forming a liquid slag layer. Samples taken during casting have revealed convective flows in the flux layer and mass exchange with the liquid metal. Coefficients of the developed dimensionless function have been determined empirically for Ti‐transport from the interface into the flux layer.