Mehdi Mosharaf Dehkordi, Mehrdad T. Manzari, H. Ghafouri and R. Fatehi
– The purpose of this paper is to present a detailed algorithm for simulating three-dimensional hydrocarbon reservoirs using the blackoil model.
Abstract
Purpose
The purpose of this paper is to present a detailed algorithm for simulating three-dimensional hydrocarbon reservoirs using the blackoil model.
Design/methodology/approach
The numerical algorithm uses a cell-centred structured grid finite volume method. The blackoil formulation is written in a way that an Implicit Pressure Explicit Saturation approach can be used. The flow field is obtained by solving a general gas pressure equation derived by manipulating the governing equations. All possible variations of the pressure equation coefficients are given for different reservoir conditions. Key computational details including treatment of non-linear terms, expansion of accumulation terms, transitions from under-saturated to saturated states and vice versa, high gas injection rates, evolution of gas in the oil production wells and adaptive time-stepping procedures are elaborated.
Findings
It was shown that using a proper linearization method, less computational difficulties occur especially when free gas is released with high rates. The computational performance of the proposed algorithm is assessed by solving the first SPE comparative study problem with both constant and variable bubble point conditions.
Research limitations/implications
While discretization is performed and implemented for unstructured grids, the numerical results are presented only for structured grids, as expected, the accuracy of numerical results are best for structured grids. Also, the reservoir is assumed to be non-fractured.
Practical implications
The proposed algorithm can be efficiently used for simulating a wide range of practical problems wherever blackoil model is applicable.
Originality/value
A complete and detailed description of ingredients of an efficient finite volume-based algorithm for simulating blackoil flows in hydrocarbon reservoirs is presented.
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F.T. Seyidov, Y. Mansoori and J. Taghi Nezhad
This paper seeks to address the preparation of new compositions of hydrophobicizing liquids as release agent for press moulds in the production of plastic articles of all kinds of…
Abstract
Purpose
This paper seeks to address the preparation of new compositions of hydrophobicizing liquids as release agent for press moulds in the production of plastic articles of all kinds of polymers.
Design/methodology/approach
Mixtures of thermo‐stable polyethers (copolymer of ethylene oxide and propylene oxide) and polyols esters/mixed esters in the presence of phenothiazine as antioxidant were prepared and tested.
Findings
All compositions were tested and compared with silicone oil polymethylsiloxane‐100 (PMS‐100). The lubricant was manually applied on a hot surface (160‐190°C) of tray of press mould, without any change in the operating cycle. The finished products were easily removed from press mould, and showed higher durability. The release agent was also checked for production of polyethylene lids by automatic moulding at 170‐200°C, and 17 lids have been obtained on one application. This is quite a good result compared with silicone oil PMS‐100, which produced only four to five lids.
Research limitations/implications
Because of complexity of obtained mixture, it was impossible to study the structure and composition of the obtained products by modern spectroscopy techniques.
Practical implications
In order to obtain compositions of optimum properties a lot of mixtures were prepared and tested. Only compositions which showed suitable properties were reported.
Originality/value
This paper provides detailed information on the experimental preparation of 37 compositions for hydrophobicizing mould release agents. Testing of different obtained hydrophobicizing liquids showed positive results, in production of plastic household articles, over silicone oil PMS‐100. The finished products were easily removed from press mould and prepared hydrophobicizing liquids showed higher durability than silicone oil PMS‐100. The obtained compositions are also favored from the point of view of commercial availability and ecology and can be considered as replacements for PMS‐100 release agent.
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Nadia M. Thha, M. Moustafa, N. Abd El‐Khalik and A.M. Naser
Triethanolamine derivatives of fatty acids were incorporated in an alkyd formulation as the ingredient source of polyol. The various parameters affecting the resin formation were…
This paper attempted to show the potential relationship between five different interaction coefficients relating solvents and polymers. This review addressed primarily a…
Abstract
Purpose
This paper attempted to show the potential relationship between five different interaction coefficients relating solvents and polymers. This review addressed primarily a comparison between the polymer-solvent interaction coefficients obtained from two different types of models. These two primary polymer-solvent interaction coefficients included the Flory-Huggins interaction coefficient developed from thermodynamic colligative properties and the polymer-solvent Sudduth interaction coefficient obtained from the generalized viscosity equation. The other three interaction coefficients included Hildebrand solubility parameter and the interaction coefficients or constants for the Huggins and Kraemers models that are normally generated from viscosity measurements. The paper aims to discuss these issues.
Design/methodology/approach
These five different interaction coefficients were compared from theoretical considerations as well as on the basis of available experimental data.
Findings
Remarkably the polymer-solvent interaction coefficients for both Flory-Huggins interaction coefficient and the Sudduth interaction coefficient were found to be dimensionless and approximately of the same value. In addition, when both interaction coefficients are negative then both describe solvents. In addition, both interaction coefficients describe a plasticizer when they are in the range of 0 to ½. Finally both interaction coefficients describe a non-solvent or a suspension when both are greater than 1. The Hildebrand solubility parameter was found to be directly related to the Flory-Huggins interaction coefficient. The viscosity constants for the Huggins and Kraemers models were found to be included as subsets of the Sudduth generalized viscosity model.
Research limitations/implications
The strong apparent relationship between these five different interaction coefficients to predict the interaction between polymers and solvents is strongly indicated based on the results from this study. However, approximately half of these interaction coefficients have been derived to be evaluated from colligative properties and half were derived to be evaluated from viscosity measurements.
Practical implications
In general, it is much easier to obtain viscosity measurements compared to the evaluation of the colligative properties. Therefore, if a direct relationship can be shown between these five different interaction coefficients, then it would appear to be much easier to evaluate polymer-solvent interactions from the interaction coefficients obtained from viscosity measurements.
Originality/value
This is the first time that these five interaction coefficients have been compared in such a way that shows their direct relationship even though half of these interaction coefficients have been derived to be evaluated from colligative properties and half were derived to be evaluated from viscosity measurements.
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In an age of educational reform which incentivises increased digitisation and standardisation, teachers are expected to embrace the rise of ‘new’ tools and pedagogies with limited…
Abstract
In an age of educational reform which incentivises increased digitisation and standardisation, teachers are expected to embrace the rise of ‘new’ tools and pedagogies with limited agency to inform, question or direct what ‘newness’ must be brought into their classrooms. Drawing on my research with English as a Foreign Language (EFL) educators in South Africa and using an ‘excessive entitlement’ lens, I showcase how teachers' lack of agency can result in ‘defensive’ and ‘coercive’ practices in the classroom which are a far cry from the education transformation imagined according to either global and local imaginaries for teaching and learning. If we are interested in an educational revolution, I argue that a fundamental reorientation in education recognising teachers' agency in informing change is necessary. To do so requires theoretically driven intervention methodologies which view the competing demands placed on teachers as entry points to developing their agency and volition to find practices which work for them and their students in the classroom. To that end, I illustrate how Cultural-Historical Activity Theory (CHAT) informed interventions like Change Laboratories could aid in this fundamental repositioning for teachers regarding transformational efforts and their far-reaching potential for educational revolution becoming conscious of and overcoming their feelings of excessive entitlement.
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Firdovsi Tataroglu Sejidov and Yagoub Mansoori
The paper aims to study the effects of introducing oxypropyl segments into the trimethylolpropane (TMP) esters along with lowering the linear chain length from C5‐C9 to C5‐C6 on…
Abstract
Purpose
The paper aims to study the effects of introducing oxypropyl segments into the trimethylolpropane (TMP) esters along with lowering the linear chain length from C5‐C9 to C5‐C6 on the properties of base lubricants.
Design/methodology/approach
Various amounts of oxypropylene segments were introduced into the TMP skeleton and obtained polyols subsequently esterified by pure C5‐, C6‐, and mixture of C5‐C6‐ aliphatic monocarboxylic acids of normal structure (SFAc mixture).
Findings
Introducing oxypropylene segments into TMP skeleton, along with lowering the carboxylic acid chain length from C5‐C9 to C5‐C6, ester base lubricants obtained improved mechanical and wear preventive characteristics.
Research limitations/implications
Because of complexity of obtained mixture, it was impossible to study the structure and composition of the obtained products by modern techniques such as high field NMR spectroscopy.
Practical implications
The obtained materials have high boiling points under reduced pressure (2 mmHg). Producing higher vacuums will make the distillation process easier.
Originality/value
This paper fulfils detail information on the experimentally preparation of oxypropylated TMPs as synthetic base lubricants. The synthesized compounds showed improved properties such as high viscosity at 100°C, low pour point, high flash point, and totally excellent viscosity‐temperature properties than simple TMP esters and some literature reported ester base lubricants.
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Dinesh Ramkrushna Rotake, Anand Darji and Jitendra Singh
The purpose of this paper is a new thin-film based sensor proposed for sensitive and selective detection of mercury (Hg2+) ions in water. The thin-film platform is easy to use and…
Abstract
Purpose
The purpose of this paper is a new thin-film based sensor proposed for sensitive and selective detection of mercury (Hg2+) ions in water. The thin-film platform is easy to use and quick for heavy metal ions (HMIs) detection in the picomolar range. Ion-selective self-assembled monolayer's (SAM) of thiol used for the detection of HMIs above the Au/Ti top surface.
Design/methodology/approach
A thin-film based platform is suitable for the on-field experiments and testing of water samples. HMIs (antigen) and thiol-based SAM (antibody) interaction results change in surface morphology and topography. In this study, the authors have used different characterization techniques to check the selectivity of the proposed method. This change in the morphology and topography of thin-film sensor checked with Fourier-transform infrared spectroscopy, surface-enhanced Raman scattering spectroscopy, atomic force microscopy and scanning electron microscopy with energy dispersive x-ray analysis used for high-resolution images.
Findings
This thin-film based platform is straightforward to use and suitable for real-time detection of HMIs at the picomolar range. This thin-film based sensor platform capable of achieving a lower limit of detection (LOD) 27.42 ng/mL (136.56 pM) using SAM of Homocysteine-Pyridinedicarboxylic acid to detect Hg2+ ions.
Research limitations/implications
A thin-film based technology is perfect for real-time testing and removal of HMIs, but the LOD is higher as compared to microcantilever-based devices.
Originality/value
The excessive use and commercialization of nanoparticle (NPs) are quickly expanding their toxic impact on health and the environment. The proposed method used the combination of thin-film and NPs, to overcome the limitation of NPs-based technique and have picomolar (136.56 pM) range of HMIs detection. The proposed thin-film-based sensor shows excellent repeatability and the method is highly reliable for toxic Hg2+ ions detection. The main advantage of the proposed thin-film sensor is its ability to selectively remove the Hg2+ ions from water samples just like a filter and a sensor for detection at picomolar range makes this method best among the other current-state of the art techniques.
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M. Moustafa, I.A. Sabbah, A.M. Naser and F. Abd El‐Hai
Most of the “alkylolamides” are derived from ethanola‐mines and fatty acids like stearic, lauric, myristic and oleic. The general method of preparation of these compounds involves…
Abstract
Most of the “alkylolamides” are derived from ethanola‐mines and fatty acids like stearic, lauric, myristic and oleic. The general method of preparation of these compounds involves the use of low molecular weight aminohydroxy compounds and acylation of amino group with higher fatty acids. Amino group may be primary or secondary. Also, hydroxyl group may be more than one.
Peter Greenwood and Borje Gevert
The purpose of this paper is to study methods of reacting the surface of the particles of silica sols with silanes, primarily gamma‐glycidoxypropyltrimethoxysilane (GPTMS) and…
Abstract
Purpose
The purpose of this paper is to study methods of reacting the surface of the particles of silica sols with silanes, primarily gamma‐glycidoxypropyltrimethoxysilane (GPTMS) and study some basic properties of the modified sols and the nature and structure of the silane groups attached to the particle surface.
Design/methodology/approach
The surface of the silica particles was modified by reacting the silica sols with aqueous solutions of silanes, chiefly GPTMS. The presence and structure of silane groups on the particle surface were established by Si‐NMR and C‐NMR, respectively.
Findings
Several silanes were studied but silica sols could be readily modified only with GPTMS and glycidoxypropylmethoxydiethoxysilane (GPMDES), most readily if the silanes were pre‐hydrolysed in water. Higher degrees of silylation were preferably done by continuous addition of silane. Lower degrees of modification can be achieved at room temperature by the stepwise addition of the silane solution. The silylation of the silica surface with GPTMS significantly reduces the number of charged surface groups and silanol groups. GPTMS binds covalently to the silica surface and the epoxy ring opens and transforms into a diol. Silica sols modified with GPTMS and GPMDES are stable toward aggregation.
Research limitations/implications
Only organo‐reactive silanes were studied.
Originality/value
This is the first work to study the modification by silanes of silica aquasols with high concentrations of silica. The silane modification can extend the use of silica to areas of applications previously inaccessible to silica sols.