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Anti-Flammable Properties of Cotton Fabrics Using Eco Friendly Inorganic Materials by Layering Self-Assisted Processing
Sechin Chang,
Brian Condon,
Elena Graves,
Jade Smith
Issue:
Volume 7, Issue 4, July 2018
Pages:
115-125
Received:
20 April 2018
Accepted:
5 May 2018
Published:
22 May 2018
Abstract: A flame retardant surface has been prepared by the layer-by layer assemblies of branched polyethylenimine (BPEI), kaolin, urea, and diammonium phosphate (DAP) on cotton fabrics. Four different kinds of cotton fabrics (print cloth, mercerized print cloth, mercerized twill, and fleece) were prepared using solutions of BPEI, urea, DAP, and kaolin. Layer-by-layer assemblies for flame retardant properties were applied by the pad-dry-cure method and each coating formula was rotated for 10, 20, 30, or 40 bilayers. To assess the effectiveness to resist flame propagation on treated fabrics of different constructions the vertical flammability test (ASTM D 6413-11) was used. In most cases char lengths of fabrics that passed the vertical flammability tests were less than 50% of the original length and after-flame and after-glow times were less than one second. Thermogravimetric analysis (TGA) and limiting oxygen indices (LOI, ASTM D 2863-09) were also used to test for flame retardancy. All untreated fabrics showed LOI values of about 19-21% oxygen in nitrogen. LOI values for the four types of treated fabrics were greater than 35% when add-on wt% values were between 11.1 – 18.6 wt %. In addition, structural characterizations of treated fabrics were studied by SEM methods.
Abstract: A flame retardant surface has been prepared by the layer-by layer assemblies of branched polyethylenimine (BPEI), kaolin, urea, and diammonium phosphate (DAP) on cotton fabrics. Four different kinds of cotton fabrics (print cloth, mercerized print cloth, mercerized twill, and fleece) were prepared using solutions of BPEI, urea, DAP, and kaolin. Lay...
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A Molecular Dynamics Study on the Miscibility of Polyglycolide with Different Polymers
Mahamat Bichara Abderaman,
El-Hadji Oumar Gueye,
Abdoulaye Ndiaye Dione,
Alioune Aidara Diouf,
Omar Faye,
Aboubaker Chedikh Beye
Issue:
Volume 7, Issue 4, July 2018
Pages:
126-132
Received:
30 April 2018
Accepted:
31 May 2018
Published:
13 June 2018
Abstract: The miscibility of mixtures between polyglycolide and the following polymers: polyethylene, polystyrene, polyacrylonitrile and polylactide is studied by Molecular Dynamics Simulation using Forcite and Blends Modules. The simulations of the binary mixture for the evaluation of the energy is achieved in the framework of the Flory-Huggins model. The Flory-Huggins interaction parameter, the mixing energy and the phase diagrams are analyzed and found to be the main parameters and features controlling the miscibility process in the present computer simulations. The results of the simulation show that when the Flory-Huggins interaction parameter Chi to a value close to 1 of mixtures the polyglycolide / polylactide, polyglycolide / polyacrylonitrile, polyglycolide / polyethylene and polyglycolide / polystyrene are miscible at 50K, 230K, 238K and 378K respectively. The commonly-accepted miscibility criteria of the binary namely mixing when Chi is negative or positive but small and non-miscibility when Chi is positive and higher than 1 is used in the present analysis. This led to the evaluation of a mixing energy of 1.5kcal/mole. The phase diagrams of all the binary mixtures are similar and present one critical point. The miscibility of the binary mixtures at that critical point corresponds to an optimal mole fraction of 0.5 but for different temperature for each binary mixture. In fine, the polyglycolide is miscible with polylactide for all the temperature range and above 378K for polyacrylonitrile, polyethylene and polystyrene. The results obtained are in agreement with those found in the literature.
Abstract: The miscibility of mixtures between polyglycolide and the following polymers: polyethylene, polystyrene, polyacrylonitrile and polylactide is studied by Molecular Dynamics Simulation using Forcite and Blends Modules. The simulations of the binary mixture for the evaluation of the energy is achieved in the framework of the Flory-Huggins model. The F...
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Numerical Simulation and Analysis on the Instability and Deformation of the L245/316L Bimetallic Clad Tube Liner
Zhao Yufei,
Han Wenli,
Zhou Bing,
Zhang Yingying,
Guo Jiyin,
Zhang Yanjun
Issue:
Volume 7, Issue 4, July 2018
Pages:
133-141
Received:
18 July 2018
Published:
19 July 2018
Abstract: The quality of the L245/316L bimetallic clad tube is greatly decided by the stability of the liner. In this work, the ABAQUS finite element software was used to simulate and analyze the instability and deformation of the L245/316L bimetallic clad tube liner during the coating process under different temperatures and during the compression and depressurization process under the condition that whether there was defect in the substrate and liner. The simulation and analysis results demonstrated that coating under the temperature of 230°C could result in the instability deformation of the liner because of the combining effects of thermal expansion and contraction, residual stress and external constraint. In addition, defects between the substrate and liner could lead to the instability deformation of the liner in the compression and depressurization process.
Abstract: The quality of the L245/316L bimetallic clad tube is greatly decided by the stability of the liner. In this work, the ABAQUS finite element software was used to simulate and analyze the instability and deformation of the L245/316L bimetallic clad tube liner during the coating process under different temperatures and during the compression and depre...
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The Preparation of Transparent Silicone Rubber with Rapid Vulcanization and Ultraviolet Absorbing Effect
Issue:
Volume 7, Issue 4, July 2018
Pages:
142-146
Received:
28 May 2018
Accepted:
23 July 2018
Published:
17 August 2018
Abstract: Silicone materials have excellent weathering resistance, high and low temperature resistance, anti-yellowing and a series of excellent properties over other materials. In this study vinyl silicone oil as the base polymer, hydrogen silicone oil as a cross-linking agent, vinyl silicone resin and ultraviolet absorber as additives, platinum complex as a catalyst, were used to make ultraviolet absorption of highly transparent silicone rubber. Different structures of silicone resin with vinyl group have different effects on the curing speed of the products. The silicone resin with MMViQ can help achieve rapid curing speed. Due to polarity difference for polysiloxane system and ultraviolet absorber, when necessary a suitable organic solvent may be introduced to increase the compatibility of the ultraviolet absorber with the silicone composition to prepare transparent products. Considering that the addition of organic solvents may have effects such as volatiles and properties, the amount of solvent introduced should be as low as possible. In addition, regarding the amount of the ultraviolet absorber added, too little ultraviolet absorber may not achieve a satisfactory ultraviolet absorption effect, but too much would lead to an increase in the amount of solvent introduced. Different ultraviolet absorber could induce different ultraviolet absorption effect and aging resistance.
Abstract: Silicone materials have excellent weathering resistance, high and low temperature resistance, anti-yellowing and a series of excellent properties over other materials. In this study vinyl silicone oil as the base polymer, hydrogen silicone oil as a cross-linking agent, vinyl silicone resin and ultraviolet absorber as additives, platinum complex as ...
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An Experimental Study on Treatment of Typical Low and Intermediate Level Radioactive Wastes with Thermal Plasma Melting Technology
Wenzhang Xie,
Peng Lin,
Jie Lu,
Xiajie Liu,
Mingzhou Chen,
Yonghong Lv
Issue:
Volume 7, Issue 4, July 2018
Pages:
147-152
Received:
3 June 2018
Accepted:
19 July 2018
Published:
21 August 2018
Abstract: With the active development of the nuclear industry in China, it is extremely urgent to study and develop advanced technologies for the radioactive waste treatment and disposal. With features of high temperature, high energy density and broad applicability, the thermal plasma melting technology has been considered as one of the key subjects in the radioactive waste treatment research field. A pilot scale experimental study was carried out on the treatment of typical low and intermediate level radioactive wastes (LILWs) from the nuclear power plant in China with thermal plasma melting technology. Two representative wastes, thermal insulation waste and cotton, were selected and melted in the plasma melting furnance at 1250°C for ~ 100 minutes until they were completely vitrified. Meanwhile, tracers of Co2O3, CsCl and SrCO3 were added to the original wastes to simulate the containment effect of 58Co and 60Co, 134Cs and 137Cs as well as 90Sr in the vitrification during the treatment process. The XRD patterns of both vitrification samples displayed as the typical amorphous state. Performances of resultant glass waste-forms, including the physical property, the leachability and the mechanical capacity, were in accordance with the standard requirements of the hign level radioactive waste glass vitrificaton, and were better than those of the cement solidified waste. Further experimental work is in need to better understand the radioactive nuclide migration regularity and to improve the performance of the plasma melting system.
Abstract: With the active development of the nuclear industry in China, it is extremely urgent to study and develop advanced technologies for the radioactive waste treatment and disposal. With features of high temperature, high energy density and broad applicability, the thermal plasma melting technology has been considered as one of the key subjects in the ...
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Spent Lead-Acid Batteries Crushing Mechanical Properties and Impact Crushing Effect
Wu Caibin,
Li Bensheng,
Yuan Chenfang,
Zhao Jieming,
Ye Jingsheng,
Ni Shuainan
Issue:
Volume 7, Issue 4, July 2018
Pages:
153-160
Received:
10 July 2018
Accepted:
21 August 2018
Published:
11 September 2018
Abstract: The spent lead-acid battery contains a large amount of lead metal and waste acid. If not treated or simply treated, it will cause serious environmental pollution and even endanger human health. The paper focuses on the recovery of valuable resources such as lead paste and plastic by replacing chemical methods with physical ones, which the bending performance was tested with electronic universal testing machine and the impact performance measured with plastic pendulum impact testing machine. At the same time, a self-designed crusher is also used for impact crushing. The test results showed that the plastic shell is hard and brittle and has strong resistance to bending, but its impact resistance is weak. The spent lead-acid batteries were crushed by self-designed impact crusher. In the broken products, the grids and fiber separators were distributed between 2.2-0.5 mm in diameter, while plastics mainly over 10 mm and lead paste mainly below 0.1 mm. The XRD results show that the lead in each particle size has different forms and contents of lead. Different comminution experiments show that the appropriate process parameters can achieve the existence of valuable resources such as plastics, grids, and lead pastes in spent lead-acid batteries according to their shape and size, which helps the subsequent sorting and recovery of valuable materials.
Abstract: The spent lead-acid battery contains a large amount of lead metal and waste acid. If not treated or simply treated, it will cause serious environmental pollution and even endanger human health. The paper focuses on the recovery of valuable resources such as lead paste and plastic by replacing chemical methods with physical ones, which the bending p...
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Comparative Study of Heterostructure Barrier Diodes in the GaAs/AlGaAs System
Mise Akura,
Geoffrey Dunn,
Mohammed Missous
Issue:
Volume 7, Issue 4, July 2018
Pages:
161-166
Received:
16 September 2018
Published:
18 September 2018
Abstract: A comparative study of the electron transport property and operation of the Potential Well Barrier (PWB) diode and Planar-doped Potential-well Barrier (PPB) diode has been carried out in this study. Both diodes are heterostructures in GaAs/AlGaAs system with similarities in layer design though, with a sheet charge inserted close to the well of the PPB diode. A drift-diffusion and Monte Carlo simulation models were used throughout the study to examine the behavior of electrons in terms of the electric field distribution across the diodes, electron velocities, electron energy and densities. Results of simulation has shown how the electric field varies in the left and right intrinsic regions of the device and the effect of the field on velocity. The I-V characteristics of the experimental and simulation results have shown a good agreement in the two diodes though, with little adjustment of about ± 2.5% to design parameters in order to obtain a good fit with experimental results. The I-V characteristics of the diodes reveal that the PPB diode turns on at a higher voltage than the PWB diode though, with a better asymmetry in the reverse bias operation. This is because the sheet charge in the PPB diode produces additional charge and together with the charge in the well, presents a higher potential barrier than the PWB diode whose barrier is determined by the charge in the well only. The diodes demonstrate promising RF behavior with voltage responsivity of 10900V/W and 6400V/W at 10GH for the PPB and PWB diodes respectively.
Abstract: A comparative study of the electron transport property and operation of the Potential Well Barrier (PWB) diode and Planar-doped Potential-well Barrier (PPB) diode has been carried out in this study. Both diodes are heterostructures in GaAs/AlGaAs system with similarities in layer design though, with a sheet charge inserted close to the well of the ...
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