Mahmood Farzaneh-Gord, Hamid Reza Rahbari and Hossin Nikofard
One of the most important issues regarding Natural Gas Vehicles (NGVs) is the Driving Range, which is defined as capability of a NGV to travel a certain distance after each refueling. The Driving Range is a serious obstacle in the development and growth of NGVs. Thus the necessity of studying the effects of various parameters on the Driving Range could be realized. It is found that the on-board storage capacity and the natural gas heating value have the greatest effect on the Driving Range. The charged mass of NGV cylinders is varied due to the natural gas composition and the final in-cylinder values (temperature and pressure). Underfilling of NGV cylinders, during charging operations, is a result of the elevated temperature which occurs in the NGV storage cylinder, due to compression and other processes could be overcome by applying extensive over-pressurization of the cylinder during the fuelling operation. Here, the effects of the most important parameters on the Driving Range have been investigated. The parameters are natural gas composition, engine efficiency and final NGV on-board in-cylinder temperature and pressure. It is found that, the composition has big effects on the Driving Range. The results also show that as final in-cylinder pressure decreases (or temperature increases), the Driving Range will be increased.
Kinetics and thermodynamics of gossypol extraction from defatted cottonseed meal by ethanol
Gossypol is polyphenolic aldehyde, a toxic substance naturally present in cotton plant to protect it from insects, pests and diseases. Maximum gossypol is concentrated in the seed. After extraction of oil from the cottonseed, the defatted cottonseed meal which contains both the gossypol and proteinous matter is left behind. A number of attempts have been made using different solvents to extract gossypol from the seeds. However, all these efforts have remained in the realm of academic activity only as none of them could be commercialized. If a pilot plant or commercial scale plant is to be developed then the data on the kinetics and thermodynamics of the extraction process is required. In this study ethanol has been used as the solvent at temperature below 323K for removal of gossypol from the defatted seed. This study finds the effects of parameters viz. temperature, solvent to solid ratio (SR) and extraction time on the gossypol extraction efficiency. The data obtained are used to establish the kinetics and thermodynamics of the extraction process.
Dongfang Huang, Hong Zheng, Zeyu Liu, Amin Bao and Bo Li
Application of 1-butyl-3-metyhlimidazaolium hexafluorophosphate ([C4mim][PF6]), in the extraction of rubidium and cesium from brine solutions using 1,4,7,10,13,16-hexaoxacyclooctadecane (18C6) as extractant was investigated. Parameters that affect the extraction including pH of aqueous phase, equilibration time, dosage of the ionic liquid, phase ratio, concentration of 18C6 were studied. Under the optimal conditions, the single extraction efficiency of rubidium ions and cesium ions were up 84.11% and 94.99%, respectively. The stripping of alkali metal ions from the loaded organic phase with different stripping agents and concentrations were also investigated. The initial value of the K/Cs and K/Rb ratios were 93.0 and 104.3, respectively, which have dropped 91.21% and 88.01%, respectively, after the extraction and stripping experiments. It was taken a big step in the separation and enrichment of cesium (rubidium) ion and potassium ion. The extraction mechanism was revealed most likely to be a cation exchange mode in this system.
Ehsan Sadeghi Pouya, Hooman Fatoorehchi and Mohammad Foroughi-Dahr
The aim of the present work is to study the efficiency of a biocompatible polymer-based adsorbent for the removal of Pb (II) ions whose devastating effects on people’s health is a matter of great concern from aqueous solution. In this study, ethyl cellulose and gamma-Al2O3 nanoparticles/ethyl cellulose electrospun adsorbents were prepared for the batch removal of Pb (II) ions from aqueous solution. Both samples were characterized using contact angle analysis, N2 adsorption/desorption technique, FT-IR and SEM. The Freundlich model (R-square = 0.935 and RMSD (%) = 6.659) and the Dubinin-Radushkevich model (R-square = 0.944 and RMSD (%) = 6.145) were found to be more reliable in predicting the experimental data from the adsorption of Pb (II) ions onto the electrospun gamma-Al2O3 nanoparticles/ethyl cellulose than the Langmuir model (R-square = 0.685 and RMSD (%) = 14.61) and also the Temkin model (R-square = 0.695 and RMSD (%) = 14.38).
The study was aimed at investigating the effect of the Fe3O4 hybrid deposited on graphene oxide (GO-Fe3O4) on the relative viability and DNA integrity. The properties of the GO-Fe3O4 hybrid were analyzed using a transmission electron microscopy (TEM), X-ray diffraction technique (XRD) and thermal gravimetric method (TGA), while the efficiency of graphene oxide covalent functionalization with iron oxide nanospheres was determined by Fourier transform infrared spectroscopy (FT-IR). L929 and MCF-7 cell lines were selected to analyze the biocompatibility of GO-Fe3O4 nanoparticles. The hybrid was tested using WST-1 and LDH leakage assays. DNA integrity was analyzed by agarose gel electrophoresis and micronucleus assay was performed to examine chromosomal damage in the exposed cell lines. The tested GO-Fe3O4 hybrid did not significantly reduce cell metabolism of L929 cells. GO-Fe3O4 hybrid particles only slightly affected the integrity of cell membranes. DNA integrity and micronucleus assays did not indicate genotoxicity of the hybrid.
In this paper, Co,Ce/Ca10(PO4)6(OH)2 catalysts with various cobalt loadings for steam reforming of ethanol (SRE) were prepared by microwave-assisted hydrothermal and sol-gel methods, and characterized by XRD, TEM, TPR-H2, N2 adsorption-desorption measurements and cyclohexanol (CHOL) decomposition tests. High ethanol conversion (close to 100%) was obtained for the catalysts prepared by both methods but these ones prepared under hydrothermal conditions (HAp-H) ensured higher hydrogen yield (3.49 mol H2/mol C2H5OH) as well as higher amount of hydrogen formed (up to 70%) under reaction conditions. The superior performance of 5Co,10Ce/HAp-H catalyst is thought to be due to a combination of factors, including increased reducibility and oxygen mobility, higher density of basic sites on its surface, and improved textural properties. The results also show a significant effect of cobalt loading on catalysts efficiency in hydrogen production: the higher H2 yield exhibit catalysts with lower cobalt content, regardless of the used synthesis method.
Mohammad Taghi Ghaneian, Mohammad Hasan Ehrampoush, Asghar Mosleh Arany, Behzad Jamshidi and Mahboobeh Dehvari
In this study the removal of Cr (VI) from synthetic wastewater was investigated using Acroptilon repens (Russian Knapweed) flower powder under various conditions (pH, contact time and initial concentration of Cr). The capacity of chromium adsorption at equilibrium conditions by this biosorbent was increased by adsorbate concentration. The results also showed that the removal efficiency of Cr (VI) was increased by increasing the contact time. By increasing the initial concentration of Cr (VI) solution, chromium removal was reduced. The suitability of adsorbents and their constants was tested or evaluated with the Langmuir, Freundlich and Temkin isotherms models. The results indicated that the Freundlich and Langmuir models (R2 > 0.99) gave a better concordance to the adsorption data in comparison with the Temkin equation (R2 = 0.97). The adsorption of Cr (VI) followed the pseudo-second-order kinetics (R2 = 0.991). The study showed that Acroptilon repens flower powder can be used as an effective lignocellulosic biomaterial and biosorbent for the removal of Cr (VI) from wastewater.
Meral Yildirim, Azmi Seyhun Kipcak and Emek Moroydor Derun
In this study, sonochemical-assisted magnesium borate synthesis is studied from different boron sources. Various reaction parameters are successfully applied by a simple and green method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies are used to characterize the synthesized magnesium borates on the other hand surface morphologies are investigated by using scanning electron microscope (SEM). The XRD analyses showed that the products were admontite [MgO(B2O3)3 · 7(H2O)] with JCPDS (Joint Committee on Powder Diffraction Standards) no. of 01-076-0540 and mcallisterite [Mg2(B6O7(OH)6)2 · 9(H2O)] with JCPDS no. of 01-070-1902. The results that found in the spectroscopic studies were in a good agreement with characteristic magnesium borate bands in both regions of infra-red and visible. According to SEM results, obtained borates were in micro and sub-micro scales. By the use of ultrasonication, reaction yields were found between 84.2 and 97.9%. As a result, it is concluded that the sonochemical approach is a practicable synthesis method to get high efficiency and high crystallinity in the synthesis magnesium borate compounds.
Vegetable oils derivatives as the modifiers of the lubricating properties of water
Water has been used as a lubricating medium in a number of applications in tribology. Its insufficient lubricating properties are modified by appropriate additives. The aim of the tribological studies presented in this paper is an application of a mixture containing triglyceride ethoxylates and partial glycerides as well as esters and a block copolymer as additives. All the components are commercially available and relatively cheap. In order to examine the aqueous solutions, two kinds of tests were carried out on a four-ball apparatus: at the fixed load - measurements of the friction coefficient and wear as a function of time and seizure tests which made it possible to determine the scuffing load (Pt), the seizure load (Poz) and the limiting pressure of seizure (poz). Changes in the quantities measured were analyzed as a function of concentrations ranging from 0.001% to 100%. In the fixed load tests the coefficient of friction decreased almost eight-fold, reaching the lowest value of 0.06 at above 0.1% concentration of the additive. Wear decreased over 3.5-fold. In the seizure tests a relatively high efficiency of the additive package was observed at the concentration of the order of the thousandth part of one percent. The compositions reached the maximum anti-seizure capacity at the concentrations of 4 and 10%. It is particularly interesting to note that the stability of the lubricating film being formed was characterized by the scuffing load. The maximum value of Pt was about 4kN high. Summing up, on the basis of the results obtained it may be concluded that the choice of package additives was correct and it effectively modified the lubricating properties of water.
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