VOLUME 39, NO2, APR-2017
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The Experimental Research of the Effect of Heating Temperature and Heating Time for Oil Shale Crack

Yi Pan, Shidong Wang, Yue Zhang and Shuangchun Yang

The oil shale from open-pit oil shale mine of Fushun, Liaoning province was chosen as our study objective, the effect of the time and temperature on oil shale crack was studied. The results showed that with the temperature increasing, crack width, length and quantity increased. When temperature was greater than 300 ℃, the length and quantity increased rapidly, so, the threshold temperature was 300 ℃; with the heating time increasing, the crack width and quantity increased first, then decreased, while the length presented an increase. The crack quantity reached the maximum for heating 8 h and crack width reached the broadest at 6 h. So the optimum heating time is 6-8 h.
Pages(177)
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Mechanical and Rheological Characterization of Efficient and Economical Structural Wood-Plastic Composite of Wood and PVC

Muhammad Zeshan Ali and Atif Javaid

Light weight materials and specially composites are being investigated to replace metallic materials. In this research work, fiber reinforced composites are fabricated and investigated. Wood-Plastic Composites (WPCs) are developed which contain cellulosic fiberous-wood as fiber and Poly(vinylchloride) PVC thermoplastic as matrix materials. A compatibilizer was developed to make better adhesion between hydrophobic PVC matrix and hydrophilic wood fibers. Different grades of WPC were manufactured by varying the relative percentages of PVC and cellulosic wood fibers. WPC’s were characterized mechanically and rheologically by employing Universal Testing Machine (UTM), impact tester, Melt Flow Index (MFI) tester and melting point apparatus. Tensile mechanical testing showed that mechanical strength was improved with increasing fiber concentration but to a limit of 50 weight % fibers. Rheological testing also illustrated that the tackiness increased by increasing fiber contents.
Pages(183)
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Experimental and Theoretical Evidences for Stability of Intermediates and Reaction Path during Pulsed Laser Photo-Polymerization of Acrylate Monomers

Asma Batool, Zareen Akhter, Lubna Tabassam, Rumana Qureshi, M. Aslam Khan and Asghari Gul

Density Functional Theory (DFT) calculations at the B3LYP/3-21G basis set was carried out to determine the stability of intermediates during the pulsed laser polymerization (PLP) of acrylate monomers. The reaction path was determined successfully by calculating Electrostatic Potential Maps (ESP) for the selected systems. For this study, pulsed laser photo-initiated polymerization of methoxyacrylate monomers was carried out via a Q-switched Nd: YAG laser (2rd harmonic at 532nm). The monomers, n-butyl methoxyacrylate (B) and n-octadecyl methoxyacrylate (O) along with the activated initiator, benzoyl peroxide were dissolved in ethanol (EOH) and were exposed to the laser for 50 min. Reaction mixture, B: O in stoichiometry 1:1 for copolymerization and pure ‘B’ and ‘O’ solutions for homo-polymerization were treated with laser in order to study the reaction path based on transition state stabilities. Fourier Transform Infrared Spectroscopy (FTIR), Hydrogen Nuclear Magnetic Resonance (1H-NMR) spectroscopy and elemental analysis were used for the structural elucidation of the products. The computed results were found in good agreement with the experimental findings and the comparisons revealed the effectiveness of the DFT-computed method for predicting mechanisms and path for new reactions.
Pages(190)
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Estimation of Physico-Chemical Characteristics of Suspended Particulate Matter (SPM) at Construction Sites: A Statistical Regression-Based Model

Khalid Iqbal, Muhammad Anwar Baig and Sher Jamal Khan

Among many other sources, suspended particular matter (SPM) is generated from fine construction waste and materials (like sand, clay, silt and crushed stones etc) due to sweeping, wind blowing, traffic flow and other mechanical disturbances at the constructions sites. Characterization of this SPM is essential due to its effects on ecology, environment and human health. But sophisticated and expensive equipment, trained manpower, costly resources and continuous supply of energy, which the countries like Pakistan lack, are required for characterization. Therefore, this study aims at developing regression-based statistical models to estimate physico-chemical characteristics of SPM only by determining the corresponding characteristics of fine inert material at any construction site. A total of 168 samples, 84 of the fine inert material and similar number of samples of SPM, were collected during a period of nine months from June 2013 to February 2014 from a construction site at Lahore, Pakistan. The parameters for characterization included pH, electrical conductivity and concentrations of trace metals (Al, Ca, Ni, Fe and Zn) and ions (SO42−, NO3− and Cl−) both in inert material and SPM. The statistical analysis was performed using SPSS 16. Results showed highly significant correlation and regression between all the parameters. Significance of correlation and regression and data normality test of dependent variables (characterization parameters of SPM) indicated that regression-based models can be used for prediction of physico-chemical characteristics of the SPM by using the physico-chemical characteristics of fine inert material at any other/new construction site. Linear regression models [Y = a + b (x)] were developed to estimate and predict physico-chemical characteristics of SPM (Y). The models were applied at new construction site and differences between actual and estimated values showed that the model equations can reliably be used for characterization of SPM only by determining the corresponding characteristics of fine inert material at any/new construction sites.
Pages(197)
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Gamma Irradiation Effect on Mixed Dye Film; its Possible Use as a Radiation Dosimeter

Sayeda Eid, Hatem. Amer, Farag Eissa and Nehad Magdy

The polymer films under investigation include poly (vinyl alcohol) in a combination with mixture of two dyes, namely, 2,6-dichlorophenol indophenol sodium salt (DCP), and tetrabromophenol blue (TBPB) as pH indicator in presence of various chloral hydrate concentrations. These films undergo color change from the blue to the yellow color passing through green as an intermediate state. The decoloration of DCP started first in the beginning of reaction, followed by the transformation of TBPB to its acidic form as a result of the delivery of HCl from the radiolysis of chloral hydrate. The dosimetric parameters, eg; dose response, effect of relative humidity on response as well as before and after irradiation stability of these films were inspected. The energy band gap value of the prepared films decreased from 1.83 to 1.75 against absorbed dose. These films can be used as dosimeters for food irradiation applications where the useful dose range is recorded from 1 to 15 kGy.
Pages(208)
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Combined Impact of Quorum Quenching and Backwashing on Biofouling Control in a Semi-Pilot Scale MBR Treating Real Wastewater

Ghalib Hasnain, Sher Jamal Khan, Muhammad Zeshan Arshad and Haris Yar Abdullah

This study demonstrates the combined effect of quorum quenching (QQ) and backwashing on biofouling control in MBR treating real wastewater. The quorum quenching mechanism is an emerging biological technique using Rhodococcus sp. entrapped in polymer coated sodium alginate beads whereas, backwashing is a distinguished physical technique for biofouling control. Two parallel semi-pilot scale MBRs i.e., QQ-MBR (quorum quenching MBR) with cell-entrapping beads (CEBs) and C-MBR (conventional MBR) with vacant CEBs at 0.5% effective volume of the bioreactor, were monitored for comparative performance evaluation. In the first phase, both the MBRs were operated without backwashing having operational cycle of eight min filtration and two min relaxation and in the second phase; MBRs were operated with backwashing having operation cycle of eight min filtration, one min relaxation and one min backwashing. QQ-MBR¬ with backwashing exhibited greater biofouling control capability and elongated filtration duration with respect to QQ-MBR without backwashing. Comparatively less soluble EPS concentrations were detected in QQ-MBR as compare to C-MBR in both modes of operation while backwashing contributed to retard the rapid increase in trans-membrane pressure (TMP) also known as TMP jump. Study reveals the novelty of successful application of combined influence of permeate backflushing technique and QQ (anti-biofouling) strategy in MBR and potential use for full scale applications.
Pages(215)
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Sorption Performance of Activated Nkaliki Clay in Removing Chromium (VI) Ion from Aqueous Solution: Kinetics, Isotherm, and Thermodynamic Studies

Regina Obiageli Ajemba, Victor Ifeanyi Ugonabo and Vincent Nwoye Okafor

Bentonite from Nkaliki was modified by acid activation using different concentrations of sulphuric acid. The physicochemical properties of the raw and modified samples were analyzed. The sorption performance of the modified and raw bentonite was studied in the removal of chromium (VI) ion from aqueous solution. Effect of key process parameters on the adsorption process was studied. Results of the physicochemical analyses showed that the acid activation altered the structural arrangements of the bentonite. The surface area and adsorption capacity increased from 37.6m2/g to 74m2/g and 45 to 98%, respectively, after activating with 6mol/l of H2SO4. The chromium (VI) ion adsorption increased with increase in process parameters studied. The kinetics analysis of the adsorption data follows the pseudo second-order kinetics, while equilibrium analysis conformed to the Langmuir isotherm. The thermodynamic parameters revealed that adsorption process is spontaneous and endothermic. This study shows that modified Nkaliki bentonite could be used for wastewater treatment.
Pages(224)
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The Catalytic Cracking Mechanism of Lignite Pyrolysis Char on Tar

Zhang Lei, He Huibin, Zhang Lei, Sha Xiangling, Ma Zhenhua, Shu Hao and Tian Ye

The influence of different pyrolysis conditions for tar catalytic cracking will be analyzed according to the lignite pyrolysis char as catalyst on pyrolytic tar in this paper. The pyrolysis char what is the by-product of the cracking of coal has an abundant of pore structure and it has good catalytic activity. On this basis, making the modified catalyst when the pyrolysis char is activation and loads Fe by impregnation method. The cracking mechanism of lignite pyrolytic tar is explored by applying gas chromatograph to analyze splitting products of tar. The experimental results showed that: (1) The effect of tar cracking as the pyrolysis temperature, the heating rate, the volatilization of pyrolysis char and particle size increasing is better and better. The effect of the catalytic and cracking of lignite pyrolysis char in tar is best when the heating rate, the pyrolysis temperature, the volatiles of pyrolysis char, particle size is in specific conditions.(2) The activation of pyrolysis char can improve the catalytic effect of pyrolysis char on the tar cracking. But it reduces the effect of the tar cracking when the pyrolysis char is activation loading Fe.
Pages(234)
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Synthesis and Performance Evaluation of High-Temperature and High-Salinity Tolerance Polymer Microspheres

Yang Changchun, Yue Xiang’an, He Jie, Zhou Jilong, Li Chaoyue and Chen Gang

Various technical problems are currently encountered in using regular plugging agents. The performance of this agent in terms of high temperature and salinity tolerance is poor. The cross-linking reaction time is difficult to control and the valid period of the operation measures is short. This study system of deep profile control and water shutoff was researched for high-temperature and high-salinity reservoirs. The microstructure of divinylbenzene-co-acrylamide microspheres were designed according to the principle of deep profile control and water shutoff. Scanning electron microscopy tests, showed that the interior of the microspheres was hollow and that the shell had a nanoporous structure. The basic performance of the microspheres was evaluated, including high temperature thermal stability, injection and plugging ability and plugging effect at 115 °C. Results showed that after 180 days, the microspheres did not appear to be carbonized. The residual resistance coefficient of the injection experiment was greater than 2. Only microsphere plugging slug was used. The amplitude of enhanced oil recovery reached 7 %. Domestic oil field tests showed that, by increasing the amount of oil by 5.11 t each day after profile control, the general water percentage decreased from 64.11 % to 32.08 %.
Pages(240)
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Synthesis of (E)-N'-[1-(2,4-Dihydroxyphenyl)ethylidene]Substituted Hydrazides as Possible α-glucosidase and butyrylcholinesterase Inhibitors

Muhammad Athar Abbasi, Syed Akhtar Hussain Shah, Aziz-ur-Rehman, Sabahat Zahra Siddiqui, Ghulam Hussain, Khalid Mohammed Khan, Muhammad Ashraf and Syeda Abida Ejaz

In the current research work, (E)-N'-[1-(2,4-dihydroxyphenyl)ethylidene]substituted hydrazides were synthesized in a couple of steps and their enzyme inhibition potential was analyzed. Firstly 2,4-hydroxyacetophenone (1) was reacted with hydrated hydrazine (2) under stirring to yield (E)-4-(1-hydrazonoethyl)benzene-1,3-diol (3) which was further reacted with different acid halides, (4a-i) to afford (E)-[1-(2,4-dihydroxyphenyl)ethylidene]substituted hydrazides (5a-i). These synthesized compounds were characterized by EI-MS, 1H-NMR spectral techniques and were also evaluated against α-glucosidase and butyrylcholinesterase enzymes. The synthesized compounds were found to be acceptable inhibitors of α-glucosidase and decent inhibition against butyrylcholinesterase.
Pages(248)
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