scholarly journals Development of LDPE Crystallinity in LDPE/Cu Composites

2021 ◽  
Author(s):  
Makki Abdelmouleh ◽  
Ilyes Jedidi
Keyword(s):  
Phase Change Materials ◽  
Research Work ◽  
Orthorhombic Phase ◽  
Copper Particle ◽  
Phase Model ◽  
Spectral Simulation ◽  
Two Phase ◽  
Cu Films ◽  
Three Phase

This chapter summarizes the study of the filler (ie copper) effect on LDPE phasic composition in LDPE/Cu composites prepared in solution. During this research work, a particular effort is focused on the use of DSC under non-standard conditions. Therewith, the presence of copper microparticles has a great effect on the network phase than on the crystalline long-range-order phase of LDPE structure. Furthermore, LDPE phasic composition in absence and presence of copper microparticles is investigated by FTIR spectroscopy followed by a spectral simulation of the band that appeared at 720 cm−1 corresponding to the CH2. Anywise, the two-phase model confirmed that no variation is observed of LDPE phase composition for all copper contents into LDPE/Cu films. However, with the three-phase model the orthorhombic phase fraction was found to be constant compared to the fraction of amorphous and that of network phase were found to increase and decrease respectively with increase in the copper particle load in the film. Overall, the thermal and structural behavior of LDPE in presence of copper particles allows this type to be used as phase change materials (PCMs) by adding a paraffin fraction in the LDPE/Cu composite. An update of the most relevant work carried out in the field of phasic characterization of polyethylene is presented in this chapter.

Transport of organochlorine pesticides in soil columns enhanced by dissolved organic carbon

1997 ◽  
Vol 35 (7) ◽  
pp. 139-145 ◽  
Author(s):  
Jiann-Yuan Ding ◽  
Shian-Chee Wu
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Organochlorine Pesticides ◽  
Transport Model ◽  
Phase Model ◽  
Soil Columns ◽  
Two Phase ◽  
Three Phase ◽  
Phase Transport ◽  
Remediation Of Soil

The objective of this study is to quantify the effects of humic acid solution infiltration on the transport of organochlorine pesticides (OCPs) in soil columns using a three-phase transport model. From experimental results, it is found that the dissolved organic carbon enhances the transport of OCPs in the soil columns. In the OCPs-only column, the concentration profiles of OCPs can be simulated well using a two-phase transport model with numerical method or analytical solution. In the OCPs-DOC column, the migrations of aldrin, DDT and its daughter compounds are faster than those in the OCPs-only column. The simulation with the three-phase model is more accurate than that with the two-phase model. In addition, significant decrease of the fluid pore velocities of the OCPs-DOC column was found. When DOC leachate is applied for remediation of soil or groundwater pollution, the decrease of mean pore velocities will be a crucial affecting factor.

An Edge Dislocation in a Three-Phase Composite Cylinder Model

1991 ◽  
Vol 58 (1) ◽  
pp. 75-86 ◽  
Author(s):  
H. A. Luo ◽  
Y. Chen
Keyword(s):  
Edge Dislocation ◽  
Stable Equilibrium ◽  
Phase Model ◽  
Composite Cylinder ◽  
Two Phase ◽  
Trapping Mechanism ◽  
Three Phase ◽  
Cylinder Model ◽  
Stable Equilibrium Position ◽  
The Stability

An exact solution is given for the stress field due to an edge dislocation embedded in a three-phase composite cylinder. The force on the dislocation is then derived, from which a set of simple approximate formulae is also suggested. It is shown that, in comparison with the two-phase model adopted by Dundurs and Mura (1964), the three-phase model allows the dislocation to have a stable equilibrium position under much less stringent combinations of the material constants. As a result, the so-called trapping mechanism of dislocations is more likely to take place in the three-phase model. Also, the analysis and calculation show that in the three-phase model the orientation of Burgers vector has only limited influence on the stability of dislocation. This behavior is pronouncedly different from that predicted by the two-phase model.

Characteristics of Circulating Fluidized Bed Evaporator with Vapor-Liquid-Solid Three-Phase Flow

2012 ◽  
Vol 455-456 ◽  
pp. 1618-1626 ◽  
Author(s):  
Ji Tian Song ◽  
Jun Chi ◽  
Han Fei Zhang ◽  
Zhen Ying Liu
Keyword(s):  
Heat Transfer ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Research Work ◽  
Correlation Equation ◽  
Evaporation Process ◽  
Two Phase ◽  
Heat Transfer Efficiency ◽  
Three Phase ◽  
Three Phase Flow

In this paper, pumpkin juice concentrations were carried out using a three-phase circulating fluidized bed evaporator. The flow and heat transfer characteristics of this evaporation process were investigated and parametric studies were conducted to identify the governing parameters in the process. It was found that compared with two-phase evaporation process, addition of inert particles improved the heat transfer efficiency by 35% and also inhibit forming and clean fouls during the pumpkin juice concentration. A correlation equation of boiling heat transfer coefficient was established for the three-phase circulating fluidized bed evaporator. This research work improves the understanding of the three-phase circulating fluidized bed evaporator and benefit to its wider application in foodstuff field.

Micro-Macro Characterization of Effective Properties for Fibrous Composites With Parallelogram Cells and Imperfect Contact Condition

2011 ◽  
Author(s):  
Reinaldo Rodriguez-Ramos ◽  
Juan Carlos Lo´pez-Realpozo ◽  
Rau´l Guinovart-Di´az ◽  
Julia´n Bravo-Castillero ◽  
J. A. Otero ◽  
...  
Keyword(s):  
Effective Properties ◽  
Transverse Isotropy ◽  
Homogenization Method ◽  
Asymptotic Homogenization ◽  
Two Phase ◽  
Imperfect Contact ◽  
Three Phase ◽  
Asymptotic Homogenization Method ◽  
Theoretical Results

In this work, two-phase parallel fiber-reinforced periodic piezoelectric composites are considered wherein the constituents exhibit transverse isotropy and the cells have different configurations. Two types of imperfect contact at the interface of the composites are studied: a) imperfect contact via spring model, b) three phase model. Simple closed-form formulae are obtained for the effective properties of the composites with both types of contact and different parallelogram cells by means of the asymptotic homogenization method (AHM). Some numerical examples and comparisons with other theoretical results illustrate that the model is efficient for the analysis of composites with presence of parallelogram cells and imperfect contacts.

scholarly journals The three-phase astrochemical code: modeling of the molecular cloud composition

2021 ◽  
Author(s):  
E. V. Borshcheva ◽  
Keyword(s):  
Observational Data ◽  
Molecular Cloud ◽  
Phase Model ◽  
Chemical Compositions ◽  
Two Phase ◽  
Ice Surface ◽  
Three Phase ◽  
Phase Models ◽  
Dust Surface ◽  
Good Agreement

We describe the implementation of a three-phase astrochemical model (gas + ice surface + bulk) based on the two-phase Presta code (gas + dust surface) and provide results for calculating the molecular cloud composition. The two- and three-phase models produce significantly different chemical compositions. In particular, CO ice abundance in the three-phase model shows good agreement with the observational data, unlike the two-phase model.

scholarly journals Experimental Comparison of Three Characterization Methods for Two Phase Change Materials Suitable for Domestic Hot Water Storage

2021 ◽  
Vol 11 (21) ◽  
pp. 10229
Author(s):  
Maxime Thonon ◽  
Laurent Zalewski ◽  
Stéphane Gibout ◽  
Erwin Franquet ◽  
Gilles Fraisse ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Mass Density ◽  
Hot Water ◽  
Experimental Comparison ◽  
Two Phase ◽  
Characterization Methods ◽  
Domestic Hot Water ◽  
Significant Difference

This study presents an experimental comparison of three characterization methods for phase change materials (PCM). Two methods were carried out with a calorimeter, the first with direct scanning (DSC) and the second with step scanning (STEP). The third method is a fluxmetric (FM) characterization performed using a fluxmeter bench. For the three methods, paraffin RT58 and polymer PEG6000, two PCM suitable for domestic hot water (DHW) storage, were characterized. For each PCM, no significant difference was observed on the latent heat and the total energy exchanged between the three characterization methods. However, DSC and STEP methods did not enable the accurate characterization of the supercooling process observed with the FM method for polymer PEG6000. For PEG6000, the shape of the enthalpy curve of melting also differed between the experiments on the calorimeter—DSC and STEP—methods, and the FM method. Concerning the PCM comparison, RT58 and PEG6000 appeared to have an equivalent energy density but, as the mass density of PEG6000 is greater, more energy is stored inside the same volume for PEG6000. However, as PEG6000 experienced supercooling, the discharging temperature was lower than for RT58 and the material is therefore less adapted to DHW storage operating with partial phase change cycles where the PCM temperature does not decrease below 52 °C.

A New Algorithm for Multiphase-Fluid Characterization for Solvent Injection

SPE Journal ◽  
2016 ◽  
Vol 21 (05) ◽  
pp. 1688-1704 ◽  
Author(s):  
Ashutosh Kumar ◽  
Ryosuke Okuno
Keyword(s):  
Saturation Pressure ◽  
Binary Interaction ◽  
Liquid Density ◽  
Two Phase ◽  
Solvent Injection ◽  
Three Phase ◽  
Fluid Characterization ◽  
Multiphase Behavior ◽  
Three Phases

Summary Compositional simulation of solvent injection requires reliable characterization of reservoir fluids by use of an equation of state (EOS). Under the uncertainty associated with nonidentifiable components, reservoir fluids are conventionally characterized in the absence of universal methodology. This is true even for relatively simple fluids involving only the gaseous (V) and oleic (L1) phases. No systematic method has been presented for characterization of more-complex fluids, exhibiting three hydrocarbon phases: the V, L1, and solvent-rich-liquid (L2) phases. This paper presents a new algorithm for systematic characterization of multiphase behavior for solvent-injection simulation. The reliability of the method comes mainly from the binary-interaction parameters (BIPs) newly developed for the Peng-Robinson (PR) (Peng and Robinson 1976, 1978) EOS to represent three-phase behavior, including upper critical endpoints, for n-alkane and carbon dioxide (CO2)/n-alkane binaries. The regression part in fluid characterization broadly follows the concept of perturbation from n-alkanes, which was successfully applied for simpler two-phase fluids in our prior research. The algorithm, in its simplest form, uses only the saturation pressure and liquid density at a given composition and reservoir temperature. Case studies are presented to demonstrate the reliability of the algorithm for 90 reservoir fluids and their mixtures with solvents. Predictions are compared with experimental data for up to three phases. Results show that the simple algorithm developed in this research enables the PR-EOS to predict multiphase behavior in spite of the limited data used in the regression. Without the use of the BIPs developed in this research, the PR-EOS may fail to predict three phases, or may provide erroneous three-phase predictions.

Investigation on Liquid Segregation during Rheo-Casting Process Based on Eulerian-Granular Multiphase Model

2016 ◽  
Vol 256 ◽  
pp. 113-118
Author(s):  
Jiao Jiao Wang ◽  
Qiang Zhu ◽  
Fan Zhang ◽  
Da Quan Li ◽  
You Feng He
Keyword(s):  
Casting Process ◽  
Phase Model ◽  
Multiphase Model ◽  
Forming Process ◽  
Two Phase ◽  
Finite Element Software ◽  
Liquid Phases ◽  
Three Phase ◽  
Liquid Segregation ◽  
Semi Solid

A crucial problem concerned with the semi-solid forming process is the liquid segregation phenomena during shape formation, especially for rheo-casting process. Liquid segregation occurs due to the separation phenomena of the solid grain and the liquid phase. In this work, using commercial finite element software, the liquid segregation during rheo-casting process was numerically investigated by Eulerian-granular multiphase model based on the comparable results of single phase model, Eulerian-granular two-phase and three-phase model, along with Eulerian-granular DDPM three-phase model. In the study, solid grains and liquid phases were regarded as rigid material and non-Newtonian fluid at microscale, separately. This validation was experimentally proved and also compared to the proposed relationship of power law, Herschel-Bulkley model with yield stress at macroscale.

scholarly journals A continuum mechanical framework for modeling tumor growth and treatment in two- and three-phase systems

2021 ◽  
Author(s):  
Cass T. Miller ◽  
William G. Gray ◽  
Bernhard A. Schrefler
Keyword(s):  
Tumor Growth ◽  
Entropy Inequality ◽  
Phase Model ◽  
Treatment Modalities ◽  
Two Phase ◽  
Length Scales ◽  
Potential Models ◽  
Three Phase ◽  
Wide Range ◽  
Closure Relations

AbstractThe growth and treatment of tumors is an important problem to society that involves the manifestation of cellular phenomena at length scales on the order of centimeters. Continuum mechanical approaches are being increasingly used to model tumors at the largest length scales of concern. The issue of how to best connect such descriptions to smaller-scale descriptions remains open. We formulate a framework to derive macroscale models of tumor behavior using the thermodynamically constrained averaging theory (TCAT), which provides a firm connection with the microscale and constraints on permissible forms of closure relations. We build on developments in the porous medium mechanics literature to formulate fundamental entropy inequality expressions for a general class of three-phase, compositional models at the macroscale. We use the general framework derived to formulate two classes of models, a two-phase model and a three-phase model. The general TCAT framework derived forms the basis for a wide range of potential models of varying sophistication, which can be derived, approximated, and applied to understand not only tumor growth but also the effectiveness of various treatment modalities.

scholarly journals 3D Modelling of Mass Transfer into Bio-Composite

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2257
Author(s):  
Marouane Kabbej ◽  
Valérie Guillard ◽  
Hélène Angellier-Coussy ◽  
Caroline Wolf ◽  
Nathalie Gontard ◽  
...  
Keyword(s):  
Relative Permeability ◽  
Volume Fraction ◽  
Water Vapor Permeability ◽  
High Volume ◽  
Phase Model ◽  
Vapor Permeability ◽  
Three Dimensional Model ◽  
Two Phase ◽  
Phase Structures ◽  
Three Phase

A three-dimensional model structure that allows considering interphase layer around permeable inclusions is developed to predict water vapor permeability in composite materials made of a matrix Poly(3-HydroxyButyrate-co-3-HydroxyValerate) (PHBV) including Wheat Straw Fiber (WSF) particles. About 500 two-phase structures corresponding to composites of different particles volume fractions (5.14−11.4−19.52 % v/v) generated using experimental particles’ size distribution have permitted to capture all the variability of the experimental material. These structures have served as a basis to create three-phase structures including interphase zone of altered polymer property surrounding each particle. Finite Element Method (FEM) applied on these structures has permitted to calculate the relative permeability (ratio between composite and neat matrix permeability P/Pm). The numerical results of the two-phase model are consistent with the experimental data for volume fraction lower than 11.4 %v/v but the large upturn of the experimental relative permeability for highest volume fraction is not well represented by the two-phase model. Among hypothesis made to explain model’s deviation, the presence of an interphase with its own transfer properties is numerically tested: numerical exploration made with the three-phase model proves that an interphase of 5 µm thick, with diffusivity of Di ≥ 1 × 10−10 m2.s−1, would explain the large upturn of permeability at high volume fraction.

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