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991.
Removal of hydrogen sulfide from methane using commercial polyphenylene oxide and Cardo-type polyimide hollow fiber membranes 总被引:1,自引:0,他引:1
Mahdi Pourafshari Chenar Houman Savoji Mohammad Soltanieh Takeshi Matsuura Shahram Tabe 《Korean Journal of Chemical Engineering》2011,28(3):902-913
The performance of commercially available poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) and Cardotype polyimide (PI) hollow
fiber membranes was investigated in removing hydrogen sulfide from methane in a series of bench-scale experiments. It was
observed that in the concentration range of hydrogen sulfide in methane from 101 to 401 ppm, the methane permeability decreased
in the presence of hydrogen sulfide for Cardo-type polyimide hollow fiber membranes, whereas the PPO membrane performance
was not affected. The separation coefficients of hydrogen sulfide/methane were 6 and 4 for PI and PPO membranes, respectively.
Effects of temperature on the performance of PI and PPO membranes were investigated. It was observed that the permeabilities
of both components of the mixture increased by increasing temperature, whereas the selectivities remained constant. 相似文献
992.
993.
994.
Alumina Dissolution into Silicate Slag 总被引:1,自引:0,他引:1
Shaowei Zhang Hamid Reza Rezaie Hossain Sarpoolaky William Edward Lee 《Journal of the American Ceramic Society》2000,83(4):897-903
Dissolution of commercial white fused and tabular Al2 O3 grains into a model silicate slag was investigated after 1 h at 1450° and 1600°C. Formation of CA6 and hercynitic spinel layers was observed at all Al2 O3 /slag interfaces. The spinel layer was not always continuous, and so, compared with the CA6 layer, it had a less-significant effect on the dissolution process. The CA6 layer that formed adjacent to the tabular Al2 O3 was incomplete at both temperatures, so that its dissolution was not a totally indirect process. These incomplete CA6 and spinel layers meant that slag penetrated into the tabular Al2 O3 grains, which, thus, were corroded and disintegrated by the penetrating slag. There was evidence of liquid in the CA6 layer adjacent to the fused Al2 O3 after 1 h at 1450°C, which also enabled direct dissolution. After 1 h at 1600°C, fused Al2 O3 revealed a thick (∼60 μm), continuous and unpene-trated CA6 layer, indicating fully indirect dissolution at this temperature. 相似文献
995.
Polyaniline/zinc composites and nanocomposites were prepared using solution mixing method. Zinc (Zn) particles with an average particle size of 60 μm and zinc nanoparticles with an average particle size of 35 nm were used as fillers in polyaniline (PANI) matrix. Films and coatings of PANI/Zn composites and nanocomposites were prepared by the solution casting method. Electrical conductivity and anticorrosion properties of PANI/Zn composite and nanocomposite films and coatings with different zinc loadings were evaluated. According to the results, electrical conductivity and anticorrosion performances of both PANI/Zn composites and nanocomposites were increased by increasing the zinc loading. Also results showed that the PANI/Zn nanocomposite films and coatings have better electrical conductivity and corrosion protection effect on iron coupons compared to that of PANI/Zn composite. 相似文献
996.
One of the most important properties of clothes is their ability to help the body's thermal system to keep the body temperature in its natural range, even if the environmental conditions or physical activities are outside the body's ideal range. Perspiring is one of the most important effects of physical activities in warm weather for shedding the body's excessive heat. Therefore, the basic requirement of a fabric worn next to the skin is to transfer this moisture to the atmosphere to reach comfort through the avoidance of a feeling of wetness and clamminess and also through the generation of a situation for the best surface evaporation of moisture. The main goal of this study was to achieve a kind of fabric that guarantees comfort for the body by good heat and moisture transport. To achieve this goal, a group of double‐surface fabrics containing hydrophilic and hydrophobe fibers were knitted, and their simultaneous heat and moisture transport was evaluated with the help of a perspiration‐simulation machine; the results were analyzed as transfer process plots. Also, the transmission of heat and moisture was evaluated for all of the samples by differential modeling as an artificial neural network. Effective parameters on heat and moisture transfer were taken into consideration with modeling and statistical methods. The results were analyzed to find a suitable fabric with optimum comfort. The final results showed that a fabric made of micropolyester filaments and cotton yarns on the bottom and top surfaces, respectively, had the best heat and moisture transfer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
997.
S. Mohammad Sajadi Kamal Kolo Samir M. Hamad Sarbast A. Mahmud Mohammad Pirouei Keyvan Amjadian Karzan M. Khalid 《IET nanobiotechnology / IET》2019,13(2):124
For the first time, through a fast, eco‐friendly and economic method, the aqueous extract of the leaf of Euphorbia corollate was used to the green synthesis of the highly stable CuO@Magnetite@Hen Bone nanocomposites (NCs) as a potent antioxidant and antibacterial agent against Pseudomonas aureus, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae pathogenic bacteria. The biosynthesised NCs were identified using the scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy, elemental mapping, X‐ray diffraction (XRD), Fourier transforms infrared spectroscopy and UV–vis analytical techniques. Also, the radical scavenging activity using (2,2‐diphenyl‐1‐picrylhydrazyl) method was used to evaluate the antioxidant activity of the NCs. The stability of nanocatalyst was monitored using the XRD and SEM analyses after 30 days from its synthesis. Furthermore, its excellent catalytic activity, recycling stability, and high substrate applicability were demonstrated to the adsorption of the polycyclic aromatic hydrocarbons of the light crude oil from Shiwashok oil fields and destruction of methylene blue and methyl orange as harmful organic dyes at ambient temperature using UV–vis spectroscopy. Moreover, the green CuO@Magnetite@Hen Bone NCs were recovered and reused several times without considerable loss of its catalytic activity.Inspec keywords: nanobiotechnology, X‐ray diffraction, infrared spectra, catalysis, crude oil, Fourier transform spectra, ultraviolet spectra, scanning electron microscopy, dyes, catalysts, photochemistry, iron compounds, X‐ray chemical analysis, antibacterial activity, adsorption, visible spectra, microorganisms, organic compounds, reduction (chemical), nanomedicine, toxicology, recycling, chemical industryOther keywords: antioxidant activity, XRD, SEM analyses, recycling stability, polycyclic aromatic hydrocarbons, harmful organic dyes, UV–vis spectroscopy, green CuO@Magnetite@Hen Bone NCs, reusable CuO@Magnetite@Hen Bone NCs, recyclable CuO@Magnetite@Hen Bone NCs, antioxidant activities, antibacterial activities, highly stable magnetically nanocatalyst, eco‐friendly method, economic method, euphorbia corollate, green synthesis, CuO@Magnetite@Hen Bone nanocomposites, antibacterial agent, pseudomonas aureus, staphylococcus aureus, escherichia coli, klebsiella pneumoniae pathogenic bacteria, biosynthesised NCs, X‐ray spectroscopy, X‐ray diffraction, radical scavenging activity, antioxidant agent, 2,2‐diphenyl‐1‐picrylhydrazyl, catalytic activity, organic dye reduction, light crude oil, CuO 相似文献
998.
Ionic liquids (IL)s have been generating increasing attention over the last decade. ILs were originally introduced as alternative green reaction media owing to their distinctive chemical and physical properties of nonvolatility, nonflammability, thermal stability, and controlled miscibility. In this investigation, 5‐(4‐methyl‐2‐phthalimidyl‐pentanoylamino)isophthalic acid ( 6 ), as a bulky monomer, containing phthalimide and flexible chiral groups, has been synthesized. The direct polycondensation of this diacid monomer with several aromatic and aliphatic diisocyanates, such as 4,4′‐methylenebis(phenyl isocyanate), toluylene‐2,4‐diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate, was carried out in tetrabutylammonium bromide as a molten IL in the presence of different catalysts under microwave irradiation as well as conventional heating. The resulting polyamides (PA)s were characterized by FTIR and 1H NMR spectroscopy, inherent viscosity measurements, thermal and elemental analysis. The obtained PAs showed high yields and moderate inherent viscosities in a range of 0.32–0.57 dL g−1. The PAs were soluble in aprotic polar solvents. Thermogravimetric analysis showed that PAs are thermally stable, 10% weight loss temperatures in excess of 240 and 245°C, and char yields at 600°C in nitrogen higher than 14%. Since toxic and volatile solvent such as NMP was eliminated, this process was safe and green. It is very important to note that, because of high polarizability of ILs, they are very good solvents for absorbing microwaves. The combination of IL and microwave irradiation leads to large reductions in reaction times, very high heating rate with various benefits of the eco‐friendly approach, named green chemistry. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
999.
The metastable liquid-phase separation (MLPS) in the Cu-Co-Fe system was investigated using an electromagnetic levitation melting and solidification technique. It was found that when ternary alloys containing more than 10wt.% (12 at.%)Co and 10wt.% (11at.%)Fe were undercooled below a certain temperature, T sep, the homogeneous melt separated into two liquid phases. In alloys containing more than 54 to 57wt.% (49 to 54at.%)Cu (depending on the Co and Fe content), the phase separation generally appeared as dispersed (Fe, Co)-rich droplets (L1) in a Cu-rich matrix, whereas for alloys containing less copper, the separation resulted in Cu-rich droplets (L2) in a (Fe, Co)-rich matrix. The metastable liquid miscibility gap boundary of the Cu-Co-Fe ternary was determined using the measured T sep and the composition of the separated phases. The ternary liquid-phase separated boundaries were found to be consistent with a cross-sectioned phase diagram in which one axis represents pure copper and the other Fe + Co. 相似文献
1000.
Alireza Karimi Reza Razaghi Mahdi Navidbakhsh Toshihiro Sera Susumu Kudo 《Journal of materials science. Materials in medicine》2016,27(4):74
Although there are some traditional models of the gunshot wounds, there is still a need for more modeling analyses due to the difficulties related to the gunshot wounds to the forehead region of the human skull. In this study, the degree of damage as a consequence of penetrating head injuries due to gunshot wounds was determined using a preliminary finite element (FE) model of the human skull. In addition, the role of polyvinyl alcohol (PVA) sponge, which can be used as an alternative to reinforce the kinetic energy absorption capacity of bulletproof vest and helmet materials, to minimize the amount of skull injury due to penetrating processes was investigated through the FE model. Digital computed tomography along with magnetic resonance imaging data of the human head were employed to launch a three-dimensional (3D) FE model of the skull. Two geometrical shapes of projectiles (steel ball and bullet) were simulated for penetrating with an initial impact velocity of 734 m/s using nonlinear dynamic modeling code, namely LS-DYNA. The role of the damaged/distorted elements were removed during computation when the stress or strain reached their thresholds. The stress distributions in various parts of the forehead and sponge after injury were also computed. The results revealed the same amount of stress for both the steel ball and bullet after hitting the skull. The modeling results also indicated the time that steel ball takes to penetrate into the skull is lower than that of the bullet. In addition, more than 21 % of the steel ball’s kinetic energy was absorbed by the PVA sponge and, subsequently, injury sternness of the forehead was considerably minimized. The findings advise the application of the PVA sponge as a substitute strengthening material to be able to diminish the energy of impact as well as the load transmitted to the object. 相似文献