Effect of blend granulometry on calciothermic reduction of TiO2

Investigated was the effect of particle size of starting powder material on the calciothermic reduction of TiO₂ in the TiO₂-Ca system. According to XRD results, TiO₂ did not react with Ca after 40 h of ball milling. DTA data indicated that a decrease in the particle size of starting material resulted in lower reaction temperatures between molten Ca and TiO₂ (decrease from 1073 to 1044°C). The XRD results showed that titanium metal can be produced from nanosized starting material, and the reduction reaction progressed at lower temperatures upon a decrease in the particle size of TiO₂. Also, the particle size of the products decreased with decreasing particle size of starting TiO₂. The concentration of residual oxygen depended on the particle size of TiO₂ due to increasing surface of contact with deoxidizer (Ca).     

Magnetic nanocomposite of multi-walled carbon nanotube as effective adsorbent for methyl violet removal from aqueous solutions: Response surface modeling and kinetic study

Magnetic nanocomposite of multi-walled carbon nanotube (m-MWCNT) was synthesized for adsorptive removal of methyl violet (MV) from aqueous solutions. The experiments were conducted using a central composite design (CCD) with the variables of adsorbent dosage (0.4-1.2 g/L), solution pH (3-9), contact time (10-42 min) and ionic strength (0.02-0.1mol L^?1). Regression analysis showed good fit of the experimental data to a quadratic response surface model whose statistical significance was verified by analysis of variance. By applying the desirability functions, optimum conditions of the process were predicted as adsorbent dosage of 0.99g/L, pH=4.92, contact time of 40.98 minutes and ionic strength of 0.04 mol L^?1 to achieve MV removal percentage of 101.19. Experimental removal efficiency of 99.51% indicated that CCD along with the desirability functions can be effectively applied for optimizing MV removal by m-MWCNT. Based on the study, the adsorption process followed Langmuir isotherm model and pseudo-second-order kinetic model could realistically describe the dye adsorption onto m-MWCNT.     

Primary,Secondary Metabolites,Photosynthetic Capacity and Antioxidant Activity of the Malaysian Herb Kacip Fatimah (Labisia Pumila Benth) Exposed to Potassium Fertilization under Greenhouse Conditions

A randomized complete block design was used to characterize the relationship between production of total phenolics, flavonoids, ascorbic acid, carbohydrate content, leaf gas exchange, phenylalanine ammonia-lyase (PAL), soluble protein, invertase and antioxidant enzyme activities (ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD) in Labisia pumila Benth var. alata under four levels of potassium fertilization experiments (0, 90, 180 and 270 kg K/ha) conducted for 12 weeks. It was found that the production of total phenolics, flavonoids, ascorbic acid and carbohydrate content was affected by the interaction between potassium fertilization and plant parts. As the potassium fertilization levels increased from 0 to 270 kg K/ha, the production of soluble protein and PAL activity increased steadily. At the highest potassium fertilization (270 kg K/ha) L. pumila exhibited significantly higher net photosynthesis (A), stomatal conductance (g_s), intercellular CO₂ (C_i), apparent quantum yield (ξ) and lower dark respiration rates (R_d), compared to the other treatments. It was found that the production of total phenolics, flavonoids and ascorbic acid are also higher under 270 kg K/ha compared to 180, 90 and 0 kg K/ha. Furthermore, from the present study, the invertase activity was also found to be higher in 270 kg K/ha treatment. The antioxidant enzyme activities (APX, CAT and SOD) were lower under high potassium fertilization (270 kg K/ha) and have a significant negative correlation with total phenolics and flavonoid production. From this study, it was observed that the up-regulation of leaf gas exchange and downregulation of APX, CAT and SOD activities under high supplementation of potassium fertilizer enhanced the carbohydrate content that simultaneously increased the production of L. pumila secondary metabolites, thus increasing the health promoting effects of this plant.     

Experimental and modeling investigation of dynamic interfacial tension of asphaltenic-acidic crude oil/aqueous phase containing different ions

In this way,after experimental measurement of interfacial tension,different models including mono-exponential decay,dynamic adsorption models and empirical equation are used to correlate this time-dependent behavior of interfacial tension(IFT).During the modeling approach,the induction,adsorption,equilibrium,and meso-equilibrium times as well as diffusivity of surface active components known as natural surfactant including asphaltene and resin from crude oil to the interface are obtained.In addition,the surface excess concentration of surface active components at the interface and Gibbs adsorption isotherm are utilized to analyze the measured dynamic IFTs.Finally,the mechanisms of crude oil/aqueous solution IFT including(a)the activity of surface-active components and(b)surface excess concentration of them at fluid/fluid interface are proposed and discussed in details.     

Simultaneous Removal of Four Dye Pollutants in Mixture Using Amine Functionalized Kit-6 Silica Mesoporous Magnetic Nanocomposite

In this study, Kit-6 silica mesoporous was created on the surface of magnetite core having silica shell and functionalized by amine group to form Fe3O4@SiO     

The impact of connate water saturation and salinity on oil recovery and CO2 storage capacity during carbonated water injection in carbonate rock

Carbonated water injection (CWI) is known as an efficient technique for both CO₂ storage and enhanced oil recovery (EOR). During CWI process, CO₂ moves from the water phase into the oil phase and results in oil swelling. This mechanism is considered as a reason for EOR. Viscous fingering leading to early breakthrough and leaving a large proportion of reservoir un-swept is known as an unfavorable phenomenon during flooding trials. Generally, instability at the interface due to disturbances in porous medium promotes viscous fingering phenomenon. Connate water makes viscous fingers longer and more irregular consisting of large number of tributaries leading to the ultimate oil recovery reduction. Therefore, higher in-situ water content can worsen this condition. Besides, this water can play as a barrier between oil and gas phases and adversely affect the gas diffusion, which results in EOR reduction. On the other hand, from gas storage point of view, it should be noted that CO₂ solubility is not the same in the water and oil phases. In this study for a specified water salinity, the effects of different connate water saturations (S_wc) on the ultimate oil recovery and CO₂ storage capacity during secondary CWI are being presented using carbonate rock samples from one of Iranian carbonate oil reservoir. The results showed higher oil recovery and CO₂ storage in the case of lower connate water saturation, as 14% reduction of S_wc resulted in 20% and 16% higher oil recovery and CO₂ storage capacity, respectively.     

Involvement of Salicylic Acid on Antioxidant and Anticancer Properties,Anthocyanin Production and Chalcone Synthase Activity in Ginger (Zingiber officinale Roscoe) Varieties

The effect of foliar application of salicylic acid (SA) at different concentrations (10⁻³ M and 10⁻⁵ M) was investigated on the production of secondary metabolites (flavonoids), chalcone synthase (CHS) activity, antioxidant activity and anticancer activity (against breast cancer cell lines MCF-7 and MDA-MB-231) in two varieties of Malaysian ginger, namely Halia Bentong and Halia Bara. The results of high performance liquid chromatography (HPLC) analysis showed that application of SA induced the synthesis of anthocyanin and fisetin in both varieties. Anthocyanin and fisetin were not detected in the control plants. Accordingly, the concentrations of some flavonoids (rutin and apigenin) decreased significantly in plants treated with different concentrations of SA. The present study showed that SA enhanced the chalcone synthase (CHS) enzyme activity (involving flavonoid synthesis) and recorded the highest activity value of 5.77 nkat /mg protein in Halia Bara with the 10⁻⁵ M SA treatment. As the SA concentration was decreased from 10⁻³ M to 10⁻⁵ M, the free radical scavenging power (FRAP) increased about 23% in Halia Bentong and 10.6% in Halia Bara. At a concentration of 350 μg mL⁻¹, the DPPH antioxidant activity recorded the highest value of 58.30%–72.90% with the 10⁻⁵ M SA treatment followed by the 10⁻³ M SA (52.14%–63.66%) treatment. The lowest value was recorded in the untreated control plants (42.5%–46.7%). These results indicate that SA can act not only as an inducer but also as an inhibitor of secondary metabolites. Meanwhile, the highest anticancer activity against MCF-7 and MDA-MB-231 cell lines was observed for H. Bara extracts treated with 10⁻⁵ M SA with values of 61.53 and 59.88%, respectively. The results suggest that the high anticancer activity in these varieties may be related to the high concentration of potent anticancer components including fisetin and anthocyanin. The results thus indicate that the synthesis of flavonoids in ginger can be increased by foliar application of SA in a controlled environment and that the anticancer activity in young ginger extracts could be improved.     

Polyamide 6 nanocomposites incorporating cellulose nanocrystals prepared by In situ ring‐opening polymerization: Viscoelasticity,creep behavior,and melt rheological properties

The creep behavior and solid and melt linear viscoelasticity of novel polyamide 6 (PA6) nanocomposites reinforced with cellulose nanocrystals (CNCs) prepared via in situ anionic ring‐opening polymerization (ROP) were investigated to accelerate research efforts to develop new polymeric materials with improved properties for lightweight, load‐bearing applications. The obtained results showed that incorporation of relatively small amounts of ≤ 2wt% CNCs into the PA6 thermoplastic matrix gave nanocomposite samples with significantly enhanced creep and viscoelastic materials functions of the PA6 as indicated by lower creep strain, lower creep compliance, improved elastic recovery after removal of load, and reduced Arrhenius activation energies for time‐dependent viscoplastic flow. The obtained results were analyzed and interpreted by theoretical equations for predicting the viscoelasticity and creep behavior of polymeric systems. The melt rheological properties showed enhanced melt strength and elasticity. The formation of a percolated network structure of CNC was revealed by morphological observations that were consistent with the dynamic structure break‐up and reformation rheological experiments. The stiffness, rigidity of the CNCs along with their special ROP‐facilitated intrinsic strong chemical interactions with the PA6 matrix is believed to be responsible for the observed superior creep and viscoelastic materials functions even with very little CNC concentration. POLYM. ENG. SCI. 56:1045–1060, 2016. © 2016 Society of Plastics Engineers     

An OWA‐Based Ranking Approach for University Books Recommendation

Generally the book recommendation approaches are personalized in nature, that is, they utilize the users’ purchasing behavior to recommend them the book similar to their preferences. The main problem with the personalized recommendation is its knowledge requirement about users’ past preferences. As a result, these techniques fail in producing appropriate recommendation for a new user whose preferences are not known. The personalized recommendation also needs extra space to store the users’ preferences. In this paper, a framework to recommend books to university students for their studies is presented. In order to answer which books are to be included in the syllabus, a specialized way of recommendation, where recommendations from experts of the subjects at different universities are considered, is presented. We have suggested a ranked recommendation approach for books, which employ Ordered Weighted Aggregation (OWA), a fuzzy‐based aggregation, to aggregate the several ranking of the top universities. On the one hand, it does not need user prior preferences, and on the other hand, it eases the complexities of personalized recommendation to huge number of users and replaces it with a single ranked recommendation. The experimental results are compared with the existing positional aggregation algorithm that demonstrates significant improvement in the results with respect to various performance metrics.