bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ammonia as Alkali for Alkaline/Surfactant/Polymer Floods
Authors: Southwick Jeffrey G. , van den Pol Esther , van Rijn Carl H. , van Batenburg Diederik W. , Boersma Diederik , Svec Yi , Mastan Ahmad Anis , Shahin Gordon , Raney Kirk 
Published: June 2015

Summary
Ammonia is logistically preferred over sodium carbonate for alkaline/surfactant/polymer (ASP) enhanced-oil-recovery projects because of its low molar mass and the possibility for it to be delivered as a liquid. On an offshore platform, space and weight savings can be the determining factor in deciding whether an ASP project is feasible. Logistics may also be critical in determining the economic feasibility of projects in remote locations.
Ammonia as alkali together with a surfactant blend of alkyl propoxy sulfate/internal olefin sulfonate (APS/IOS) functions as an effective alkali. Surfactant adsorption is low, and oil recovery in corefloods is high. Static adsorption tests show that low surfactant adsorption is attained at pH &gt;9, a condition that ammonia satisfies at low solution concentration.
It is expected that ammonia has a performance deficiency relative to sodium carbonate in that it does not precipitate calcium from solution. Calcium accumulation in the ammonia ASP solution will occur, caused by ion exchange from clays. The high oil recovery for ammonia and the calcium accumulation in ASP and surfactant/polymer corefloods with APS/IOS blends show that this surfactant system is effective and calcium-tolerant. Also, phase behavior and interfacial-tension (IFT) measurements suggest that APS/IOS blends remain effective in the presence of calcium. Ethylene oxide/propylene oxide sulfates (such as the used APS) are known commercially available, calcium-tolerant surfactants. However, because of hydrolysis, sulfate-type surfactants are suitable for use only in lower-temperature reservoirs.
Very different behavior was noticed for phase-behavior measurements with calcium-intolerant surfactants such as alkyl benzene sulfonates and IOS. In this case, calcium addition results in a very high IFT and complete separation of oil and brine. Presumably, this will result in low oil recovery. A preferred approach for ASP offshore with divalent-ion-intolerant surfactants may be the use of a hybrid alkali system combining the attributes of sodium carbonate and ammonia. The concept is to supply the bulk of the alkalinity for an ASP flood by ammonia with all the inherent logistical advantages. A minor quantity of sodium carbonate is added to the formulation to specifically precipitate calcium ions.
A Laboratory and Numerical-Simulation Study of Co-Optimizing CO2 Storage and CO2 Enhanced Oil Recovery
Authors: Kamali Fatemeh , Hussain Furqan , Cinar Yildiray 
Published: June 2015

Summary
This paper presents experimental observations that delineate co-optimization of carbon dioxide (CO2) enhanced oil recovery (EOR) and storage. Pure supercritical CO2 is injected into a homogeneous outcrop sandstone sample saturated with oil and immobile water under various miscibility conditions. A mixture of hexane and decane is used for the oil phase. Experiments are run at 70°C and three different pressures (1,300, 1,700, and 2,100 psi). Each pressure is determined by use of a pressure/volume/temperature simulator to create immiscible, near-miscible, and miscible displacements. Oil recovery, differential pressure, and compositions are recorded during experiments. A co-optimization function for CO2 storage and incremental oil is defined and calculated using the measured data for each experiment. A compositional reservoir simulator is then used to examine gravity effects on displacements and to derive relative permeabilities.
Experimental observations demonstrate that almost similar oil recovery is achieved during miscible and near-miscible displacements whereas approximately 18% less recovery is recorded in the immiscible displacement. More heavy component (decane) is recovered in the miscible and near-miscible displacements than in the immiscible displacement. The co-optimization function suggests that the near-miscible displacement yields the highest CO2-storage efficiency and displays the best performance for coupling CO2 EOR and storage. Numerical simulations show that, even on the laboratory scale, there are significant gravity effects in the near-miscible and miscible displacements. It is revealed that the near-miscible and miscible recoveries depend strongly on the endpoint effective CO2 permeability.
Carbon Capture and Storage—Hard-To-Pass Decision Gates
Authors: Emhjellen Magne , Osmundsen Petter 
Published: June 2015

Summary
Socio-economic criteria for climate projects were used in analyzing the value of the climate benefit of a reduction in carbon dioxide. These reports are optimistic, yet European carbon-capture-and-storage (CCS) demonstration plants are not implemented as expected. Little attention was devoted to profitability assessments on the basis of commercial considerations. Economic valuation of climate projects, seen from the perspective of the commercial companies that are to implement the projects, is the subject of this article. We examine key economic parameters of 27 oil and gas projects and compare them to a CCS project. We find that the CCS project ranks the lowest and is unlikely to be implemented by a private company. Our findings may explain why it is hard for oil companies to justify climate projects in their portfolios.
Measurement of polychlorinated dibenzo-p-dioxin and dibenzofuran emission from EAF steel making proces
Authors: Sofilic T. , Jendričko J. , Kovačevic Z. , Ćosić M. 
Published: June 2015

Electric arc furnace (EAF) steel manufacturing is an important recycling activity which contributes to the recovery of steel resources and steel scrap/waste minimization. Because of the content of plastics, coatings and paintings as well as other nonferrous materials in the charge during melting, a strong emission of pollutants, including polluting substance group consists of persistent organic pollutions (POPs) represented by polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) occurs.
This study was set out to investigate emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/Fs) from the stack of a new electric-arc furnace-dust treatment plant installed during modernisation of the Melt Shop in CMC SISAK d.o.o., Croatia. Obtained results have been compared with previously obtained results of PCDDs/Fs emission measurements from the old electric-arc furnace dust treatment without dust drop-out box, as well as quenching tower.
The total PCDDs/Fs concentration in the stack off gases of both electric arc furnaces EAF A and EAF B were 0.2098 and 0.022603 ng I-TEQ/Nm3 respectively, and these results are close to previous obtained results by other authors. The calculated values of the emission factors for PCDDs/Fs calculated on the basis of measured PCDDs/Fs concentration in the stack off gases in 2008 and 2011 were 1.09 and 0.22 ng I-TEQ/ ton steel, respectively.
The Microstructure and Properties of Hydrostatically Extruded Polycrystalline Aluminium Al99.5 / Mikrostruktura I Własności Wyciskanego Hydrostatycznie Polikrystalicznego Aluminium Al99.5
Authors: Richert M.W. , Leszczyńska-Madej B. , Pachla W. , Skiba J. 
Published: June 2015

The changes of Al99.5 microstructure and properties deformed by hydrostatic extrusion process in the conditions of constant strain rate (1.35×102s-1) and variable deformation (φ = 1.44÷2.85) were investigated. The samples were investigated by means both optical (LM) and transmission electron microscopy (TEM). The size of subgrain was statistically measured by mean chord. To establish the influence of hydrostatic extrusion on the properties of the polycrystalline aluminium Al99.5, the microhardness was measured and the tensile test was performed.
The bands and shear bands were the characteristic feature of the sample microstructure. TEM micrographs show equiaxed subgrains with small density of dislocations inside. The measured subgrain size was placed in the range of d = 550÷650 nm. The mechanical properties of polycrystalline aluminium Al99.5 keep almost the same level in the investigated range of deformations. It was found that after the initial deformation microhardness and yield stress nearly twice increase in comparison to the initial state. The greatest increase of properties was observed after deformation φ = 1.44. Then the mechanical properties stabilize.
The Theoretical and Experimental Analyses of the Influence of Single Draft on Properties of Rope Wires / Analiza Teoretyczo-Doświadczalna Wplywu Wielkości Gniotu Pojedynczego Na Własności Drutów Liniarskich
Authors: Suliga M. 
Published: June 2015

In the paper the influence of the value of a single draft on the properties of rope wires has been assessed. The drawing process of φ5.5 mm wire rod to the final wire of φ2.18 mm was conducted in 6, 11 and 17 drafts, by means of a block drawing machine with the drawing speed of 1.6 m/s. For the wires drawn with the medium single draft: 10.4%, 15.5% and 26.5% the investigation of mechanical-technological properties has been done, in which yield strength, tensile strength, elongation, contraction, number of twists and number of bands were determined. In order to explain the effect of value of a single draft on properties of rope wires, the fatigue strength, roughness and residual stresses of drawn wires have been also determined. In addition, the numerical analysis of the drawing process on the base of Drawing 2D in which distribution of redundant strain, effective strain, longitudinal residual stresses and temperature of drawn wires has been shown.
The theoretical-experimental analysis of drawing of rope wires have enabled the evaluation of optimal value of single drafts by which relatively the most advantageous and useful properties of wires can be used. The investigation has shown, that in manufacturing of rope wires small single draft in 10% range should be applied. It allowed to obtain products of good plasticity properties, low deformation inhomogeneity and residual stresses, high bending and fatigue strength.
The obtained data investigation can be applied while designing the production process of high carbon steel wires.
Hydrogen Storage on Graphene Sheet: Physisorption, Diffusion and Chemisorbed Pathways by First Principles Calculations / Magazynowanie Wodoru Na Arkuszu Grafenu: Analiza Ścieżek Fizykosorpcji, Dyfuzji I Chemisorpcji Metodą Obliczeń Ab Initio
Authors: Costanzo F. , Silvestrelli P.L. , Ancilotto F. 
Published: June 2015

Hydrogen is frequently touted as the “fuel of the future” because of its huge potential as clean energy source, although the large-scale adoption of this technology has yet to be realized. One of the remaining barriers to the utilization of hydrogen energy is an efficient and inexpensive means of hydrogen storage. In this work we investigate the nature of this process by first principle calculation.
In particular, we study the way in which the H2 molecule can interact with graphene sheet through physisorption and chemisorption mechanism.
The first mechanism involves the condensation of the hydrogen molecule on the graphene as a result of weak van der Waals forces, while the chemisorption mechanism involves the preliminary dissociation of the H2 molecule and the subsequent reaction of hydrogen atoms with the unsatured C-C bonds to form C-H bonds.
To study carefully the possible physisorbed configurations on the graphene sheet, we take in to account van der Waals (vdW) interactions in DFT using the new method (DFT/vdW-WF) recently developed in our group and based on the concept of maximally localized Wannier functions.
There are three possible way in which the H2 molecule can adapt to the structure of graphene: the hollow, the bridge and the top site called H, B and T configurations, respectively. We find the hollow site to be most stable physisorbed state with a binding energy of -50 meV. This value, in agreement with experimental results, is also compared with other vdW-correction methods as described in the following paper.
Diffusion of the physisorbed configurations on the graphene sheet and activated reaction pathways in which the molecule starts from a physisorbed configuration to end up in a chemisorbed configurations have also been studied.
The Physical and Numerical Mesoscale Modeling of Cold Wire Drawing Process of Hardly Deformable Biocompatible Magnesium Alloys / Fizyczne I Numeryczne Modelowanie W Mezo Skali Procesu Ciągnienia Na Zimno Trudno Odkształcalnych Stopów Magnezu O Podwyższonej Biozgodności
Authors: Milenin A. , Kustra P. , Byrska-Wójcik D. 
Published: June 2015

The problem of determination of the cold low diameter wire (diameter less than 0.1mm) drawing process parameters for hardly deformable biocompatible magnesium alloys by using the mathematical mesoscale model is described in the paper. The originality of the considered alloys (MgCa0.8, A×30) is the intergranular fracture mechanism associated with small strains (0.07-0.09). In previous authors works it was proven that the material state directly before appearance of the microcracks is in the optimal state from the point of view of the recovery of the plasticity by annealing. The forecasting of this material state in drawing process requires the development of the model of intergranular fracture initiation and using this model in two cases:
- modeling of the in-situ tests, what allows calibrating and validating of the model;
- modeling of the drawing process, what allows optimizing of the drawing parameters.
A new model of the microcracks initiation in mesoscale using the boundary element method is proposed. The in-situ tests, which allowed observing the microstructure evolution during deformation, are used for the calibration and validation purpose. The model was implemented into self-developed FE software Drawing2d, which is dedicated to the drawing process. The results of mesoscale simulation were verified by the experimental drawing process of 0.07 mm diameter wires according to developed technology. It was shown by analysis of microstructure that the model allows forecasting the microcracks initiation during the wire drawing process.
Hybrid Adhesive Bonded and Riveted Joints – Influence of Rivet Geometrical Layout on Strength of Joints / Połączenia Hybrydowe Klejowo-Nitowe - Wpływ Geometrii Rozmieszczenia Nitów Na Wytrzymałość Połączeń
Authors: Sadowski T. , Zarzeka-Raczkowska E. 
Published: June 2015

The hybrid adhesive bonded and riveted joints have wider and wider application in different branches of engineering: aerospace, mechanical, civil etc. The hybrid joints’ strength is 1.5 to 3 times higher than only adhesive bonded joints’ strength. The hybrid joints characterize higher reliability during long-term working.
In this article we present the influence of rivets’ lay-out geometry on the hybrid adhesive bonded/riveted joints response to mechanical loading. Experimental research was carried using 3-D digital image correlation system ARAMIS. This system enables monitoring of the deformation processes of the hybrid joint specimen up to failure. We analysed the state of deformation of the adhesive bonded double-lap joints reinforced by different numbers of rivets. The hybrid joint specimens were subjected to the uniaxial tensile test. Moreover, the influence of geometry of individual number of rivets’ layout (rivets arranged in one or more rows) for hybrid joint strength was studied.
Experimental research was completed and supported by the computer simulations of the whole deformation processes of metal layers (aluminum), adhesive layers and rivets. Numerical simulations were conducted with the ABAQUS programme. The analysis of stress concentrations in different parts of the hybrid joint and their behaviour up to failure were investigated.
Finally, the analysis and the comparison of the obtained results confirmed the influence of rivets’ lay-out geometry not only on rivets joints but also on the hybrid adhesive bonded/riveted joints.
The Effect of Stand-Off Distance on the Structure and Properties of Zirconium – Carbon Steel Bimetal Produced by Explosion Welding / Wpływ Odległości Blach Na Strukturę I Własności Bimetalu Cyrkon - Stal Wytworzonego Technologią Zgrzewania Wybuchowego
Authors: Prażmowski M. , Paul H. 
Published: June 2015

This study focuses on the effect of the stand-off distance between the bonded plates on the properties of zirconium (Zr700) - steel (P355NL2) bimetal produced by explosion welding.
Bonding trials were carried out in parallel arrangement at constant detonation velocity. The analyses of microstructural transformations occurring in the bond zone and mechanical properties of the clad were performed for as-bonded welds, i.e. immediately following explosion welding. A general description of the obtained welds was made (height and length of the wave was determined) and the quantitative fraction of the melt zones was calculated along the bond’s length. Using optical microscopy and scanning electron microscopy (SEM) enabled the assessment of the quality of the formed bonds, initial identification of phases and quantitative analysis of the individual phases on the longitudinal section. The microhardness results were used in the analysis of hardening changes at the interface area.
The completed research proves the potential to obtain a proper bond for zirconium/carbon steel sheets. A strong effect of the stand-off distance on the strength properties of the fabricated plates was observed, and the ’direction’ of these transformations was pointed out. Optical microscopy and SEM examinations allowed determining the characteristic of the bond interface for diverse stand-off distances. It was established that increasing the stand-off distance between the plates causes the reduction of the melt area along the length of the bond, which improves strength properties of the bimetal. The analysis of the strength distribution performed based on the microhardness measurements showed that the changes occur within the distances up to 500µm from the bond interface and the highest hardening, for both zirconium and steel, is directly at the interface and then successively decreases.
Numerical Modelling of Thermal and Structural Strain in Laser Welding Process / Modelowanie Numeryczne Odkształceń Cieplnych I Strukturalnych W Procesie Spawania Techniką Laserową
Authors: Piekarska W. , Kubiak M. , Saternus Z. 
Published: June 2015

This work concerns numerical modelling of thermal and structural strain, resulting in heating and cooling of laser butt-welded joints. Numerical analysis of strain is carried out in Abaqus FEA. Through the use of additional author’s subroutines, the structural strain caused by phase transformations during heating and cooling of welded elements is taken into account in the analysis. V.I. Machnienko models as well as Continuous Heating Transformation (CHT) and Continuous Cooling Transformation (CCT) diagrams for S355 steel are implemented into UEXPAN subroutine in order to determine the kinetics of phase transformation in the solid state. The model takes into account thermomechanical properties of the base material varying with temperature.
The paper presents results of numerical simulation of temperature field, predicted structural composition, thermal and structural strain in laser butt-welded joints.
Mediation in Peer Interaction
Authors: Dawadi Saraswati 
Published: June 2015

This article examines the strategies used by the high-level English as a foreign language learners to mediate understanding in peer interactions. The data was generated from peer interactions of post graduate level students in their regular classroom. It was found that the students were able to understand communicative intent of their peers and provide support to each other; they worked collaboratively and co-constructed knowledge. They used different strategies to mediate understanding. The major strategies included: repetition, elaboration, definition, contextual cues, scaffolding, paralinguistic cues and real life examples. DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12079 Journal of NELTA, Vol 19 No. 1-2, December 2014: 47-55
Question identitaire et curricula d'histoire et éducation civique depuis les années 1980
Authors: De Cock Laurence 
Published: June 2015

Nous ferons ici l’hypothèse d’une coexistence et d’une concurrence des deux finalités identitaires de l’enseignement de l’histoire depuis une trentaine d’années. D’un côté, l’histoire scolaire reste le vecteur d’une identité nationale relevant d’un récit commun et consensuel à partager ; de l’autre, elle fait l’objet d’une inflation de demandes de reconnaissance de la part d’identités plus singulières, soucieuses d’être circonscrites comme telles dans le récit scolaire du passé. La seconde finalité ne se substitue pas à la première, elles tiennent ensemble. Nous étudierons trois moments spécifiques où s’est négociée cette concurrence : la décennie des années 1980 au cours de laquelle la question migratoire se rend politiquement visible et oblige l’École et l’enseignement de l’histoire à se repositionner ; les années 1990 où fait religieux et laïcité deviennent une manière de reconnaître et d’aborder les identités multiples tandis que se développe le paradigme mémoriel, et enfin les années 2000 où les finalités s’émiettent mais tiennent encore ensemble le multiple, le commun, le singulier et le pluriel, non sans de véritables tensions politiques.
Satisfaction professionnelle, formation et santé au travail des enseignants
Authors: Amathieu Jérôme , Chaliès Sébastien 
Published: June 2015

Après un recueil des principaux textes institutionnels du domaine, cet article propose une synthèse des résultats scientifiques relatifs aux liens pouvant être établis entre la satisfaction professionnelle des enseignants et leur santé au travail. En prenant appui sur le modèle de Duffy et Lent (2009) faisant consensus dans la littérature, il détaille plus précisément les cinq facteurs interdépendants influençant la satisfaction professionnelle des enseignants : leur type de personnalité ; leur sentiment d’efficacité personnelle ; la qualité et l’atteinte du but qu’ils poursuivent ; les conditions humaines et matérielles qui leur sont offertes dans leur établissement et les aides placées à leur disposition. L’article montre plus en détails que les préconisations des textes institutionnels en matière d’accroissement et d’adaptation de la formation pour accentuer la satisfaction professionnelle, et par-là même la santé au travail des enseignants, ne traduisent pas véritablement les résultats scientifiques. Après avoir détaillé les quelques études ayant à ce jour établi un lien de causalité entre la satisfaction professionnelle des enseignants au travail et la possibilité qui leur est offerte d’être formés, cet article ouvre finalement une nouvelle perspective de recherche.
Comment naît-on mère ?
Authors: Knibiehler Yvonne 
Published: June 2015

Les femelles animales naissent mères ontologiquement. Une femme choisit de l’être et apprend à le devenir en s’adaptant aux normes de son milieu et de son temps. Depuis que le sujet-femme a accédé à la citoyenneté, le sujet-mère assume des responsabilités nouvelles sur les plans social et politique : elle doit s’impliquer dans la gestion de la cité, dans le gouvernement de la nation et dans le processus de la mondialisation.