Rheological Investigation of Wood-Polypropylene Composites in Rotational Plate Rheometer

In this research work, the rheological properties of Wood-Plastic Composites (WPC) with some selected compositions are investigated. WPC is being recognized as a green composite that, in the past 20?years, has emerged to a commercial product. A study on rheological properties of these materials can give insight into the proper selection of composition and processing condition. Two grades of polypropylene (PP) with two different melt flow indexes (MFI) were selected to prepare WPCs with three different wood contents (50, 60 and 70?% wt.). Four types of rheological experiments were performed utilizing a rotational plate rheometer: (1) strain sweep, (2) frequency sweep, (3) temperature sweep and (4) steady shear rate sweep. The independent variables were chosen as wood content, MFI of polymer (two types), melt temperature, frequency or shear rate, the gap between the plates, and strain percentage. The strain sweep tests specified the linear and non-linear viscoelastic zones of each experiment. The results of frequency sweep experiments indicated that increasing the wood content and frequency and also decreasing the strain percentage and the gap distance, lead to an increase in the storage modulus. Regarding the loss modulus, wood percentage and the gap distance presented positive effects and strain percentage showed a negative effect. The behavior of complex viscosity was almost similar to that of the storage modulus but increasing the frequency caused a decrease in the complex viscosity. In case of temperature sweep experiments, it was observed that the rheological properties exhibit a rapid change near to a temperature of 160?°C. The results also showed that beyond this point, increasing the wood content and also MFI of polypropylene caused an increase in the storage modulus. The results of steady shear rate sweep experiments specified that increasing wood content and also decreasing the MFI of PP, the gap distance and shear rate lead to an increase in both viscosity and shear stress.     

Noble metal catalysts for methane removal

Using a bench-scale rig, the activities of Pt, Pd and Pt+Pd catalysts supported on gamma-Al(2)O(3) and on TiO(2) (anatase) for the complete oxidation of methane (300 ppmv) in air have been measured as a function of temperature; values of T(10), T(50) and T(90) together with the Arrhenius parameters (activation energy and pre-exponential factor) are reported. Pt is less active than Pd when deposited on the surface of the TiO(2), but more active when deposited on gamma-Al(2)O(3), however when combined, the Pt+Pd mixture is more active than either metal individually. The T(10) for Pt+Pd/gamma-Al(2)O(3) was being as low as 228 degrees C. The significance of the Arrhenius parameters, for metal containing catalysts is that they exhibit compensation with increasing activation energy, while securing a more rapid increase in conversion from 0% to 100% when the temperature is increased.     

The potential use of ultrasound-assisted bleaching in removing heavy metals and pigments from soybean oil using kinetic,thermodynamic and equilibrium modeling

Environmental Science and Pollution Research - In this research, the sorption behavior (kinetic, isotherm, and thermodynamic modeling) of heavy metals (Cu (II) and Fe (II)) and pigments (carotenoid...     

Source identification of polycyclic aromatic hydrocarbons (PAHs) in sediment samples from the northern part of the Persian Gulf,Iran

Samples of surface sediments from the Iranian coast of the Persian Gulf were examined to determine the levels and sources of 15 polycyclic aromatic hydrocarbons (PAHs). Samples were collected from 30 sampling sites and analyzed for PAHs by gas chromatography–mass spectrometry (GC-MS). Total concentrations of PAHs ranged from 93 to 4,077 ng g^?1 dry weight. The PAH composition from 30 sampling sites was dominated by four-ring PAH compounds. Molecular indices based on the ratios of PAH concentrations were used to differentiate PAHs from pyrolitic to petrogenic and mixed origins. The results suggested that the main sources of PAHs in sediments from the studied region were mixed pyrolitic and petrogenic. Furthermore, benthic organisms in most of the investigated areas were not at ecotoxicological risk, according to the results from the effects range low (ERL)/effects range median (ERM) techniques suggested by the US Sediment Quality Guidelines (SQGs).     

Economic growth and environmental pollution in Myanmar: an analysis of environmental Kuznets curve

Environmental Science and Pollution Research - This empirical study examines the short- and long-run relationship between GDP as an economic growth indicator and CO2 emissions as an environmental...     

Ultrasound-assisted ionic liquid-based microextraction combined with least squares support vector machines regression for the simultaneous determination of aluminum,gallium, and indium in water and coal samples

A new simple and rapid ultrasound-assisted ionic liquid-based microextraction method was applied to preconcentrate aluminum(III), gallium(III), and indium(III) ions from water samples as a prior step to their simultaneous spectrophotometric determination using least squares support vector machines regression. In the novel procedure, 1-hexyl-3-methylimidazolium hexafluorophosphate [C₆MIM][PF₆] was dispersed into the aqueous sample solution as fine droplets by ultrasonication, and the analytes were extracted into the ionic liquid phase after complexation with 1,2,5,8-tetrahydroxy anthraquinone (quinalizarine). After centrifuging, the fine droplets of extractant phase were settled to the bottom of the conical-bottom glass centrifuge tube. The detection limits for Al(III), Ga(III), and In(III) were 1.70, 2.02, and 2.06 ng mL⁻¹, respectively. The precision of the method, evaluated as the relative standard deviation obtained by analyzing a series of ten replicates, was below 3.2% for all elements. The method was successfully applied for the determination of Al(III), Ga(III), and In(III) in real samples.     

Characterization and Optimization of Persian Gum/Whey Protein Bionanocomposite Films Containing Betanin Nanoliposomes for Food Packaging Utilization

Journal of Polymers and the Environment - In this study, composite packaging films were produced from relatively inexpensive materials including Whey protein isolate (WPI) and Persian gum (PG),...     

Optimization and treatment of wastewater of crude oil desalting unit and prediction of scale formation

In this article, one of Iran’s southwest oil fields that produces 3200 barrels per day (bbl/d) of wastewater from oil and gas processing was investigated. Experimental analysis of oil reservoir water and desalting wastewater disposal of crude oil desalting unit was performed. First, water was treated with a reverse osmosis membrane. As a result, the purified water, with lower total dissolved solids (TDS) and pH, was a suitable candidate for injection into the adjacent wells of the crude oil desalting unit. The effectiveness and compatibility of this wastewater to the formation water of the oil field wells were simulated. Finally, we studied and identified the formation, the amount, and the type of mineral scale deposits. These are the most important problems during water injection into the wells. The analysis shows that the refined water from the reverse osmosis (RO) process was a suitable and low-cost economical option for injection in onshore and offshore fields, due to the low amount of salts, the concentration of susceptible ions in scaling formation, and the appropriate pH. This oil field, which is in the second half of life, requires enhanced oil recovery methods (EOR) for the maintenance of pressure and an increase in oil recovery.

     

A fuzzy multi-stakeholder multi-criteria methodology for water allocation and reuse in metropolitan areas

In this paper, a fuzzy decision making methodology is proposed to find a socially optimal scenario for allocating effluent of wastewater treatment plants and urban and suburban runoffs to agricultural regions and recharging aquifers. The presented methodology named modified fuzzy social choice (MFSC) considers multi-stakeholder multi-criteria problems under uncertainties inherent in a decision making process utilizing a fuzzy ranking method and the fuzzy social choice (FSC) theory. A set of water and wastewater allocation scenarios are proposed for water quantity and quality management of the study area, while six main stakeholders with conflicting utilities and different negotiation powers are involved. The proposed methodology is applied to Tehran metropolitan area, the capital city of Iran with the population of about 8 million people, to examine its applicability and effectiveness. The results shows that using fuzzy multi-stakeholder multi-criteria decision making method considering equal and different negotiation powers can lead to different outcomes. Based on the results, the MFSC method, which considers a number of decision makers having different negotiation powers, degrees of importance of decision making criteria, and some important uncertainties, performs more promising in real water resources management problems.     

Regional convergence of energy-environmental efficiency: from the perspective of environmental constraints

Environmental Science and Pollution Research - This paper conducts a convergence analysis on the energy-environmental efficiency to explore the differences between regions that reflect the...