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International Review of Chemical Engineering (Rapid Communications) - December 2010 (Vol. 2 N. 7) - Papers

SPECIAL ISSUE

Selected papers from:

2^nd Conference on Chemical Engineering and Advanced Materials

VIRTUAL FORUM (CEAM-VF 2010)

Preface to the Special Issue
Gas-Liquid Filtration Studies in Co-Current Down Flow Monolith Reactor
Thermoeconomical Optimization of Energy Intensive Systems on Graphs
Finite Difference Simulation of Cr(VI) Reduction and Cr(VI) Concentration Profiles in Aquifer Microcosm Columns
Mathematical Models for Mixing Time of Some Additive Free Calcium Soap Lubricating Greases
Non-Newtonian Effect of Blood in Physiologically Realistic Pulsatile Flow
Mixing Time in 40 Ton Refining Ladles
Study of Diesel Fine Particles Fueling with Two Biodiesel Blends
Enhancement of Hydrogen Recovery from Partial Oxidation of Methane Under Periodic Operation Conditions
Kinetics of Sulphonation of Polystyrene Butadiene Rubber in Sulphuric Acid Medium
Simulation Framework to Evaluate the Range of Hydrogen Fuel Cell Vehicles
Evaluation of Tincalconite as a Neutron Shielding Material and Confront with Borax and Colemanite
H2 Generation From Thermochemical Water-Splitting Using Sol-Gel Synthesized Zn/Sn/Mn-doped Ni-Ferrite
Numerical Simulation of Domestic Hot Water Production by Solar Way
Kinetics Study of Carbon Dioxide Absorption into Aqueous Potassium Carbonate Promoted with Boric Acid
Exergy Analysis of Post Combustion CO2 Capture Process
Modelling Pyrolysis of a Medium Density Polyethylene
Growth Stresses in α-Cr2O3 Thermal Oxide Films of FeCr50 Determined by Ex-Situ High Temperature Raman Spectroscopy
Analysis of Delamination Buckling and Post Buckling of Composite Structure by Generalized Differential Quadrature Method (GDQM)
An Efficient Equipment for Control and Monitoring in Green Composites LCM Manufacturing. A New Proposal for Anionic Reactive Injection Molding of Caprolactam

International Review of Chemical Engineering (Rapid Communications) - Papers

Preface to the Special Issue
by Jordan Hristov

Vol. 2. n. 7, p. 779

Gas-Liquid Filtration Studies in Co-Current Down Flow Monolith Reactor
by Mohsen Hamidipour, Faïçal Larachi

Vol. 2. n. 7, pp. 780-785

Abstract - The hydrodynamic behavior of a monolith reactor experiencing deposition from fines-contaminated flows was studied to evaluate its aptitude to be an alternative for trickle bed reactors under filtration conditions. Bed was subjected to single-pass kaolin-kerosene suspension and air flows to study the influence of different operating conditions. To reduce the extent of deposition, feed flow rate modulation strategies for cleaning of deposits were tested. The dynamics of liquid pulsations generated via cyclic operation strategies was monitored using electrical capacitance tomography imaging. The X-type deposition in small opening channels can keep all the channels in operation to get the maximum benefit of catalyst. Instabilities induced by the modulation strategies favored detachment and removal of deposition for the large-opening channel monoliths. In small-channel opening monoliths, detachment followed by re-deposition downstream in the bed increased the specific deposit and pressure buildup in flow modulation. Consequently, small-opening channels can be recommended for isoflow filtration of suspensions whereas large-diameter channels are preferable for cyclic operations.

Keywords: Monolith, Deposition, Filtration, Hydrodynamics, Electrical Capacitance Tomography.

Thermoeconomical Optimization of Energy Intensive Systems on Graphs
by Vladimir Nikulshin

Vol. 2. n. 7, pp. 786-794

Abstract - In the design and operation of energy intensive systems the problem of improving the efficiency is very important. The main way for solving this problem is optimization. This paper describes the general approach for thermoeconomical optimization systems with linear structure as well as systems with pair interplay of flows.
The suggested method is based on building and analysis of special graphs of thermoeconomical expenditure. The method is illustrated by an example of a system optimization for thermal treatment of chlorine water as well as a numerical example of a heat exchanger network optimization with one-time interaction of six-flows.

Keywords: Optimization, Exergy, Thermoeconomics, Graphs.

Finite Difference Simulation of Cr(VI) Reduction and Cr(VI) Concentration Profiles in Aquifer Microcosm Columns
by Phalazane J. Mtimunye, Dimingo Manyisi, Pulane Molokwane, Evans M. N. Chirwa

Vol. 2. n. 7, pp. 795-800

Abstract - This study is an initial step towards the development of an in situ bioremediation process to prevent the spread of Cr(VI) in groundwater aquifers. The study was conducted using columns with five sampling ports along the length. Cr(VI) concentration was measured in the influent, in five equally spaced intermediate ports within the column and in the effluent, to facilitate spatial modelling of Cr(VI) concentration profiles within the column. Four Cr(VI) feed concentrations: 20, 30, 40, and 50 mg.L-1, were evaluated. Near complete Cr(VI) removal was achieved in less than 4 days in the inoculated reactor with organic carbon source at an initial Cr(VI) concentration of 20 mg.L-1, whereas only 69.5% of Cr(VI) removal was achieved at 20 mg.L-1 in an inoculated column without organic carbon source after 4 days of operation. The transport of Cr(VI) across the reactor was determined to be coupled to adsorption and non-competitive inhibited reaction kinetics. However, the effects of the physical chemical processes  adsorption and biosorption  diminished in comparison with reaction rate during long-term operation. Cr(VI) reduction kinetics in anaerobic batch studies followed the non-competitively inhibition rate kinetics with km =0.132 mg.L-1, Kc = 672.0935 mg.L-1, Rc = 0.0390947 mg.mg-1 and Cr = 100 mg.L-1. Biological reduction of Cr(VI) across the columns was simulate by a one dimensional dispersion-reaction model. The predicted values from this model were then compared with experimental results for validation.

Keywords: Bioremediation, Microcosm Columns, Chromium (VI) Reduction Kinetics, Organic Electron Donors.

   Mathematical Models for Mixing Time of Some Additive Free Calcium Soap Lubricating Greases
         by Ancaelena Eliza Sterpu, Irina Niţă, Anişoara Arleziana Neagu, Anca Iuliana Dumitru, Sibel Geacai
           Vol. 2. n. 7, pp. 801-804

Abstract - Mixing is among the most common processes in chemical, biochemical, pharmaceutical, polymer, mineral, food, and wastewater treatment industries [1]. Several examples of greases mixing processes can be found in the literature [2]-[5].
Four greases were prepared with different concentration of calcium soap: 5%, 10%, 15% and 20% in paraffin oil. The preparation formulas for these four greases and manufacture method were presented in a recent work [6].
The aim of this study was to find a mathematical model for the mixing time of some additive-free lubricating greases. The mathematical modeling consisted on finding an accurate equation linking the mixing time (tm) and the Reynolds number (Re) at different soap concentrations and temperatures.
The mixing experiments were carried out in a laboratory autoclave equipped with an anchor impeller, without baffles, at 8 speed ratio, from 100 to 800 rpm.
The models resulted from the tm variation versus Re are power function type , where the coefficients a and b are functions of soap concentration in base oil and the processing temperature.

Keywords: Calcium Soaps Greases, Laboratory Autoclave, Mixing Time.

Non-Newtonian Effect of Blood in Physiologically Realistic Pulsatile Flow
by S. Karimi, B. Dabir, M. Dadvar

Vol. 2. n. 7, pp. 805-810

Abstract - In this paper the non-Newtonian effects of blood on flow features are studied in stenosis arteries. Two axisymmetric stenosis models were constructed with area reduction of 50% and 75%. A measured human common carotid artery blood flow waveform was used as the upstream flow condition which has a mean Reynolds number of 300. The assumption of laminar flow is considered for modeling. Numerical simulations in which grids are adapted corresponding to velocity profiles are used to solve the equations. The corresponding numerical predictions for Newtonian fluids were compared with the experimental flow patterns. The results indicate a satisfactory agreement in both quality and quantity. The same model is then used for blood as a non-Newtonian fluid. Two rheological models, power law and carreau fluid, are studied for comparing the wall shear stress and velocity profiles in the post stenotic region. The results indicate that other than the differences between Newtonian and non-Newtonian models, various non-Newtonian models display different flow patterns. Therefore to realize the pulsatile flow behavior in stenosis arteries, the actual rheological model should be considered.

Keywords: Blood Flow, Carreau Model, Non Newtonian Fluid, Power Law, Pulsatile Flow.

   Mixing Time in 40 Ton Refining Ladles
         by A. Bencomo, D. Garcia, Y. Loyo, R. Morales Dávila
          Vol. 2. n. 7, pp. 811-814

Abstract - In this work the relationship of the mixing time with the height bath, slag presence, and volumetric flow rate in a refining ladle of 40 ton has been determined. A physical model of scale 1:7 of acrylic was used. The metal, gas and slag was simulated by water, air and paraffin oil respectively. The heights bath varied from 0.16 to 0.25 m and the volumetric flow rate from 9.01.10-6 Nm3/s to 1.03.10-5 Nm3/s, with the fixed slag height of 0.02 m . The mixing time was determined by pH measurements with a data acquisition system. A high concentrated sulfuric acid solution was used as a marker. Experiments with center and off-center injection of gas had been done. The slag presence increased the mixing time. The results found for bath height higher than 0.16 m, suggest that off-center injection is better than the centric. With the center injection and bath height of 0.20 m and a flow rate of 1.03.10-5 Nm3/s an irregular increase of mixing time was found. In general when the bath height is 0.16 m or higher an increase of volumetric flow rate results in a lower mixing time.

Keywords: Modeling, Ladle, Metallurgy, Time, Mixing, Cold, Model.

Study of Diesel Fine Particles Fueling with Two Biodiesel Blends
by Md. Nurun Nabi, Johan Einar Hustad

Vol. 2. n. 7, pp. 815-819

Abstract - In the current study, fine particle emissions from two biodiesel blends were investigated in a 4-stroke, 6-cylinder, direct injection (DI) diesel engine. 20 vol% jatropha biodiesel was blended with 80 vol% European auto diesel fuel and 80 vol% marine gas oil (MGO). Jatropha biodiesel is made from inedible jatropha oil. The basis for selection of jatropha biodiesel was to avoid the food versus fuel conflict, while the European auto diesel fuel and MGO were chosen for their similar fuel properties. In the investigation, an electrical low pressure impactor (ELPI) of Dekati limited was used to measure the particle mass and number emissions with respect to their sizes. For comparison, the experiment was extended for measuring the fine particle number with a scanning mobility analyzer (SMPS). The particle size for ELPI measurement was in the range of 17-10000 nm and that for SMPS measurement was 5-1000 nm. To investigate fine particle and total particulate matter (TPM), a dilution tunnel was used to collect the particle mass on glass fiber filter. The dry soot, a composition of total particulate matter (TPM) was also measured. The results indicate that combustion of B20 M80 blend showed significantly higher particle number (peaking at 26 nm) than that of B20 D80 blend at all loads. The particle mass (ELPI measurement) for B20 M80 was also higher at all loads. At high load condition, both measurements (ELPI and SMPS) showed significantly lower fine particle emissions with B20 D80 blend. Regarding fine particle number emissions, both measurements showed different particle numbers quantitatively, but qualitatively similar in nature. The total particulate matter (TPM) and smoke (soot) emissions were lower for the B20 D80 blend compared to B20 M80 blend.

Keywords: Biodiesel, European Auto Diesel, MGO, Particle Number and Mass Emissions.

Enhancement of Hydrogen Recovery from Partial Oxidation of Methane Under Periodic Operation Conditions
by Lemnouer Chibane, Brahim Djellouli

Vol. 2. n. 7, pp. 820-831

Abstract - In this work we study the effects of the forcing composition and sweeping gas modulation, applied to the partial oxidation of methane carried out in a Pd-membrane reactor used for pure hydrogen production. It is assumed that the inputs imposed feature a steady component and a time dependent component. To analyze the effect of the inputs modulation, the reaction was conducted under low steam to methane ratio (0.5) and at moderate temperature (500°C) and pressure (1.5bar). The results obtained may be used to characterize the influence of modulation effects on the behavior of the process showed the positive effect of periodic operation on reactor performance. It was found that there was an enhancement of the investigated performance used to characterize the process. The level of methane conversion and hydrogen recovery exceeded that which was found in the case of steady state conditions. Under the investigated conditions a reduction of the H2/CO ratio was also achieved.

Keywords: Hydrogen Production, Modulation, Periodic Operations, Pd-Membrane Reactor.

Kinetics of Sulphonation of Polystyrene Butadiene Rubber in Sulphuric Acid Medium
by Abdulkareem A. S., Idibie C. A., Afolabi A. S., Pienaar H. C. vZ, Iyuke S. E.

Vol. 2. n. 7, pp. 832-839

Abstract -Aromatic sulphonation has been widely used in chemical synthesis. Hydrocarbon polymers consisting of polymer groups that retain high amount of water over a wide range of temperature are particularly attractive and relatively cheaper to synthesise than perfluorinated polymers hence can be easily sulphonated to improve their performance for fuel cell application. In this work, the sulphonation kinetics of polystyrene butadiene rubber (PSBR) in sulphuric acid was investigated and the synthesised rubber was also characterized to determine the ion exchange capacity (IEC), degree of sulphonation (DS), thermal stability and morphology. The sulphonation was observed at five different temperatures (24, 35, 45, 65 and 75oC) and time range of 2-24 hours for kinetics investigation. The fraction of sulphonation was calculated from the ratio of DS. The results obtained revealed that reaction is first order with respect to PSBR repeat unit and for the reaction temperature range of 24-75oC, an activation energy of 16.37kJ/mol was obtained. The analyses of results obtained on the characterization of the membrane also revealed that the synthesised membrane is thermally stable, with ion exchange capacity in the range of 0.066-0.442mmol/g which corresponds to the degree of sulphonation of 5.05-32.48% depending on the sulphonation time and temperature, consequently the synthesised membrane is proposed to be suitable for fuel cell application.

Keywords: Polystyrene Butadiene Rubber, Kinetics, Sulphonation time and Degree of Sulphonation.

Simulation Framework to Evaluate the Range of Hydrogen Fuel Cell Vehicles
by A. Sanchez, A. Cancela, S. Urrejola, R. Maceiras, V. Alfonsín

Vol. 2. n. 7, pp. 840-844

Abstract - This paper describes a vehicle simulation tool, which is used to estimate a fuel cell vehicle range from a real GPS vehicle route. The simulation model is a function of many mechanical and physical variables that depends not only on the vehicle but also on the ground. This framework can be extended to GPS track files by means of read data files plugins. The simulations basis works from a real track that can be introduce from gps data or cartography. Standard cycles can be also simulated. From simulations environment many output data can be obtained. Thus, hydrogen consumption, hydrogen storage tank level, power consumption and fuel cell energy production, maximum range, maximum number of cycles for a real route. The principal application of this tool is to help to conceptual design and unit sizing of a real life-service fuel cell-hydrogen vehicle.

Keywords: Fuel Cell Vehicles; Hydrogen Hybrid Vehicles; Simulation Tool.

Evaluation of Tincalconite as a Neutron Shielding Material and Confront with Borax and Colemanite
by A. S. Kipcak, E. M. Derun, N. Tugrul, S. Piskin

Vol. 2. n. 7, pp. 845-851

Abstract - In this study depending on the ability of neutron absorption of mineral, the structural and physical properties are examined. Firstly, the sieve analysis of mineral is made then four different particle sizes of minerals are selected, prepared and X-Ray Diffraction of minerals is made for structural analysis. After that, B2O3 contents of minerals are analyzed experimentally.
Then Na contents are analyzed with flame photometry. After these examinations X-Ray Florescence analysis is made for the determination of Zn, and Fe and Ar contents.
Thermal analysis of minerals is performed for obtaining the energy and weight changes with temperature. For this aim, the method of Differential Thermal Analysis and Thermal Gravimetry is used. Afterwards, minerals are tested in the Howitzer equipment for the nuclear absorption and confront with the borax minerals that studied before and colemanite minerals that are mostly used in the experiments at this field of study.
The B2O3 and Na content of minerals varies between the ratios (%) of 37.37 – 38.96 and 12.36 – 12.90 respectively.
At the thermal gravimetry analysis; all minerals had approximately similar weight losses and neutron absorption values vary between 11.37 % - 20.26 %. The borax mineral that has a similar molecular formula has neutron absorption values vary between 10.35 % - 13.83 % that we found at the other studies. Also these values can be compared with the colemanite mineral that it is mostly used in the experiments at this field of study. The colemanite mineral varies between the ratios of 10.01 % and 13.16 %. From the results it is seen that tincalconite mineral yields a better neutron absorption results that the both minerals of borax and colemanite.

Keywords: Tincalconite, Borax, Colemanite, Neutron Absorption.

H2 Generation From Thermochemical Water-Splitting Using Sol-Gel Synthesized Zn/Sn/Mn-doped Ni-Ferrite
by Rahul R. Bhosale, Rajesh V. Shende, Jan A. Puszynski

Vol. 2. n. 7, pp. 852-862

Abstract - This paper reports H2 generation from the thermochemical water-splitting process using the Sn-, Mn- and Zn-doped Ni-ferrites, which were prepared by sol-gel approach. The sol-gel synthesis approach involved the addition of NiCl2.6H2O, SnCl2.2H2O/ MnCl2.4H2O/ZnCl2 and FeCl2.4H2O in ethanol followed by gelation using propylene oxide (PO). As-synthesized gels were aged for 24 – 120 h, dried at 100oC and heated rapidly at the rate of 40oC/min upto different temperatures of 500oC to 1000oC and quenched in air. The powders obtained after calcination at different temperatures were characterized using the x-ray diffraction, BET surface area analyzer and scanning electron microscopy to determine the compositional purity, specific surface area (SSA) and morphology, respectively. Powders with porous morphology and higher SSA were observed for the gels calcined rapidly upto 600oC and quenched in air. After analyzing the compositional purity, the calcined powder placed in an Inconel tubular reactor and four consecutive thermochemical cycles were performed where water-splitting and regeration steps were carried out at temperatures of 800oC and 1100oC, respectively. From the results obtained, the H2 generation ability of the sol-gel synthesized ferrites was observed to be in the order of Zn-doped Ni-ferrite > Sn-doped Ni-ferrite > Mn-doped Ni-ferrite.

Keywords: Thermochemical Water-Splitting, H2 Generation, Sol-Gel, Zn/Sn/Mn-Doped Ni-Ferrite, Porous Morphology.

Numerical Simulation of Domestic Hot Water Production by Solar Way
by F. Benmeriem, M. Douani

Vol. 2. n. 7, pp. 863-870

Abstract - In steady state, the work is focused on the modeling of a system composed from solar heater water assisted by compressor. The installation is a standard heat pump where the evaporator is substituted by the solar collector. By preoccupations with an environmental protection and on the selection criteria of the refrigerant fluid, we retained R-134a. For the analysis of the installation functioning, the model developed takes account of the climatic and seasonal variations at Chlef area (Algeria) gave access to us calculation various physical and geometrical amounts in any point after specify the variables of design by the recourse to the concept of degrees of freedom. We approached the performance study by the introduction the COP concept and the collector surface Ac. The simulation results show that the collector surface and the COP reach interesting values (2m² < Ac < 7m²) and (2< COP< 5) for weather variations over the length of all the year. The influence of Tc, Tev, mr, mw and Ig was also analyzed.

Keywords: Heat Pump, Solar Collector, Simulation, Modeling, C.O.P.

Kinetics Study of Carbon Dioxide Absorption into Aqueous Potassium Carbonate Promoted with Boric Acid
by L. Pudjiastuti, E. A.Saputra, A. Altway, Susianto, Kuswandi

Vol. 2. n. 7, pp. 871-878

Abstract - Many commercial processes for removal of carbon dioxide from acid gases have used aqueous potassium carbonate promoted with amines. This paper presents kinetic data and absorption rate for aqueous potassium carbonate promoted with boric acid. Kinetics of the absorption of CO2 into 30 wt% potassium carbonate promoted with boric acid were investigated at 30, 40, 50oC by using a wetted-wall column apparatus. The addition of 0.162 – 0.485 mol.l-1 boric acid to 30 wt% potassium carbonate system results in a significant enhancement of CO2 absorption rates. Based on pseudo-first order for CO2 absorption, pseudo-first order reaction rate constants were determined from the measured kinetics data. The reaction rate constants for boric acid promoted absorption are k2 = ... and ..., with average deviation 12,11% and 1,35% respectively.

Keywords: Absorption, CO2 Removal, Kinetics, Promoter, Boric Acid.

Exergy Analysis of Post Combustion CO2 Capture Process
by Javier de J. Guadarrama, Rosa-Hilda Chavez

Vol. 2. n. 7, pp. 879-883

Abstract - Carbon dioxide capture from flue gas using amine-based CO2 capture technology requires huge amounts of energy mostly in the form of heat. The overall objective of this study is to evaluate exergy analysis using from 15 to 50 kW in boiler duty in order to regenerate the amine and to develop a model that simulates the Second Law efficiency with Aspen PlusTM. A very useful procedure for analyzing a process is by means of the Second Law of Thermodynamic establishing a set of equipment specifications and operating conditions from the process and to develop a model that simulates the removal of CO2 using Monoethanolamine (MEA) absorption from flue gas and design a process that will minimize the energy of CO2 capture with Aspen PlusTM. Thermodynamic analyses based on the concepts of irreversible entropy increase have frequently been suggested as pointers to sources of inefficiency in chemical processes. The results show that the major sources of exergy loss are the absorber (24.95%), then cold water exchangers (24.52%) and the heat exchanger (22.81%). An interesting result is that stripper (18.10%) is higher loss of exergy than set of scrubbers (9.59%) at 24 kW in boiler duty and scrubbers (15.09%) higher loss of exergy than stripper (13.03%) at 50 kW. The interpretation of the results is influenced by the definition of the system boundaries.

Keywords: CO2 Capture, Exergy Analysis, MEA, Process Modeling.

Modelling Pyrolysis of a Medium Density Polyethylene
by J. A. Capote, D. Alvear, O. Abreu, M. Lázaro, E. Puente

Vol. 2. n. 7, pp. 884-890

Abstract - A set of parameters of pyrolysis characterization of a medium density polyethylene (MDPE) was chosen to perform its behaviour under fire conditions. Two kinds of parameters, the material properties - effective values of the mass density (ρ), specific heat capacity (cP), thermal conductivity (k), absorption coefficient ( and emissivity () – and the reaction parameters – exponential factor (Z), energy of activation (), reaction mechanism f(α) and enthalpy of reaction (Δhd) – were used. Simultaneous Thermal Analyzer (STA) tests were carried out at heating rates of (3.33, 8.33 and 16.67) x10^-2Ks^-1 in N₂ atmosphere to obtain the kinetic triplet. Cone calorimeter tests at irradiance levels of (25, 40, 50 and 75) x103Wm^-2 were used both to compare and to optimize the simulated mass loss rate against real mass lost rate.

Keywords: Kinetic Triplet, Comprehensive Pyrolysis Models, Evolutionary Algorithms.

Growth Stresses in α-Cr2O3 Thermal Oxide Films of FeCr50 Determined by Ex-Situ High Temperature Raman Spectroscopy
by Amr L. Saber, Jean F. Dinhut

Vol. 2. n. 7, pp. 891-894

Abstract - Growth stresses have been investigated in relation with the microstructure in case of α-Cr2O3 growing oxide films on FeCr50 alloy. the oxidation of FeCr50 alloy has been produced at temperature of 700, 800 and 900 ◦C in air. The parabolic behaviour of oxidation was established ex situ and the corresponding cooling rate was deduced. Microscopic observations have shown that chromia grain size does not exceed 1 µm. Raman spectroscopy was used to determine stresses in chromia (Cr2O3) layers. The increasing chromia mean grain size retards the occurrence of the creep relaxation phenomena which needs an additional stress level to start. Stresses are found to be compressive and increase with the chromia thickness before reaching a “plateau” at 2.2 GPa.

Keywords: High Temperature Oxidation, FeCr50% Alloy, Chromia, Residual Stress, Stress Relaxation, Raman Spectroscopy.

Analysis of Delamination Buckling and Post Buckling of Composite Structure by Generalized Differential Quadrature Method (GDQM)
by M. Fatahi, A. Shokuhy

Vol. 2. n. 7, pp. 895-903

Abstract - Buckling and post buckling analysis of composite laminated structures having delaminations were studied numerically. The analysis were performed using the generalized differential quadrature method. Several one- and two-dimensional models were developed and showed to be capable of predicting the buckling and post buckling responses of composite beams and plates. Prediction of the buckling strength of the delaminated composite beams and the examination of the influencing factors were came out by employing several models .The effects of the shear deformation and the bending-stretching coupling were added by incorporating a shear deformation beam theory. The accuracy and efficiency of the proposed method were evaluated through several case studies. In addition to the effect of shear deformation, bending- stretching coupling, the influence of material properties, lamination sequence and fiber- orientation, through-the-thickness and through-the-length locations of delaminations on buckling and post buckling responses were investigated. For the post buckling analysis, the GDQM combined with an arc-length strategy was used to mode1 the post buckling analysis of composite beams having single or multiple delaminations. The nonlinear Von Karman strain-displacements and the exact curvatures were used to formulate the problem. The results show that the GDQ technique can be used as a powerful, reliable, accurate and efficient numerical tool in assessing the buckling and post buckling responses of delaminated composite structures. Beside the excellent quality of results that obtained through GDQM, the method is relatively simple to formulate, and it requires less effort to implement. Furthermore, the method consumes relatively less effort, both in terms of computational time and also in the user effort in setting up a problem.

Keywords: Buckling, Post Buckling, Composite, Generalized Differential Quadrature, Delamination.

An Efficient Equipment for Control and Monitoring in Green Composites LCM Manufacturing. A New Proposal for Anionic Reactive Injection Molding of Caprolactam
by J. Andres, R. Hoto, G. Molle, J. A. García

Vol. 2. n. 7, pp. 904-908

Abstract - Thermoplastic composites have competitive mechanical properties over thermoset ones, and they are more environmental friendly in terms of recovery and reutilization. Reactive processing to obtain composite materials with a thermoplastic matrix from its precursors opens a competitive alternative to melt processing. This is due to the low viscosity of the thermoplastic precursor. This study deals with the challenging requirements of the process, in terms of temperature and flow rate, to carry out a monitored injection process in a specifically designed device. The designed equipment is expected to be viable for industrial application.

Keywords: Anionic Polymerization, Caprolactam, Injection Molding, Green Composite, Thermoplastic Composite.