Comparison of Ethyl Acetate with Hexane for Oil Extraction from Various Oilseeds

The aim of the current research was to determine a less hazardous, cheaper and less toxic alternative solvent for hexane for extraction of oil from different oilseeds showing equivalent oil yield and oil quality. A full factorial design with three levels of extraction temperature (80, 100 and 120 °C) and three levels of extraction time (40, 65 and 90 min) with constant solvent to seed ratio value of 4:1 was used to extract the oil. Maximum oil was recovered from canola followed by flax, mustard and camelina. The oil content of canola was found in range of 21.08–36.44, and 25.12–40.38 % for hexane and ethyl acetate, respectively. The heating values of oil extracted from all oilseeds using hexane and ethyl acetate were found in the range of 38.04–39.98 and 37.98–39.37 MJ/kg, respectively. Least viscosity was found for flax seed using hexane followed by camelina, canola and mustard as compared to ethyl acetate. Viscosity of flax oil ranged from 27.23–37.19, and 31.16–55.52 cP for hexane and ethyl acetate solvents, respectively. Considering human safety, less environmental impact, comparable oil yield and quality parameters, ethyl acetate can be a promising alternative to hexane.     

Fast Response NO2 Gas Sensor Based on In2O3 Nanoparticles

In this research, hydrothermal‐calcination route was applied to synthesize In₂O₃ nanoparticles for gas sensor application. Hydrothermal synthesis with duration of 5 h at 180°C resulted in In(OH)₃ nanorods. Then, in the calcination step, considering controlled rate of heating and temperature, In₂O₃ nanoparticles with rough surfaces were obtained. In the next step, these nanoparticles were deposited by low frequency AC electrophoretic deposition between the interdigitated electrodes to fabricate gas sensor. Deposition in the frequency of 10 kHz resulted in the chained nanoparticles in the interelectrode space. At the end, gas sensitivity measurements were conducted at 150°C–300°C and revealed that fabricated sensor had fast response and recovery times to NO₂ gas.     

Scheduling of a mixed batch/continuous sugar milling plant using Petri nets

Scheduling of processes in mixed batch/continuous plants, due to their hybrid nature, can become very complex. This paper presents the Timed Hybrid Petri net (THPN) as a suitable tool for modelling and scheduling of hybrid systems. One of the major benefits over traditional methods is a significant reduction in complexity during problem formulation. A sugar milling plant containing both batch and continuous processing units is used to illustrate the application of the proposed scheduling algorithm.     

Dynamic Mechanical Analysis of Mountain Pine Beetle–Infested Lodgepole Pine: Effect of Time-Since-Death

Abstract

The chemical and thermo-mechanical properties of the constituent polymers mountain pine beetle (MPB)–infested Lodgepole pine were investigated by dynamic mechanical (DMA), chemical, and X-ray diffraction (XRD) analysis to validate durability as influenced by time-since-death. Chemical and XRD analysis did not show any significant differences between stages of MPB attack or location within the tree (top to bottom). However, DMA analysis revealed significant differences between the 1st and 2nd transition temperatures in the tan δ curves of the specimens.     

Preparation,characterization and properties of proton exchange nanocomposite membranes based on poly(vinyl alcohol) and poly(sulfonic acid)-grafted silica nanoparticles

Nanocomposite membranes based on the poly(vinyl alcohol) (PVA)/poly(sulfonic acid)-grafted silica nanoparticles (PSA-g-SN) were prepared via solvent casting of PVA cross linked by glutardialdehyde in the presence of various amounts (0–20 wt%) of silica nanoparticles (SN), poly(styrene sulfonic acid)- (PSSA-g-SN) and poly (2-acrylamido-2-methyl-1-propane sulfonic acid)-grafted silica nanoparticles (PAMPS-g-SN) as hydrophilic inorganic modifiers. PSA-g-SN nanoparticles were synthesized by surface-initiated redox grafting of SSA and AMPS monomers from the surface of the aminopropylated silica nanoparticles. Membranes were then characterized by FTIR, impedance spectroscopy, thermogravimetric analysis (TGA), water uptake, tensile strength test and SEM. The best proton conductivity was observed for membranes containing 5 wt% of nanoparticles. Among three nanoparticles used, the highest proton conductivity (10.4 mS/cm) was observed for PVA membrane prepared in the presence of 5 wt% PAMPS-g-SN nanoparticles. Results showed that grafting of sulfonated monomer onto the silica nanoparticles enhances various properties, for example proton conductivity, of the polymer electrolyte membranes (PEMs).     

Reduction of oxidized mercury species by dicarboxylic acids (C2-C4): kinetic and product studies

Mercury is an environmental contaminant of global concern. The reduction of oxidized mercury species (Hg(II)) by organic acids to elemental mercury (Hg0) is significant for understanding the cycling of mercury between the atmosphere and aqueous systems. This study focused on the reduction of Hg(II) by small, semivolatile dicarboxylic acids (C2-C4). The reaction kinetics was studied using cold vapor atomic fluorescence spectroscopy (CVAFS), and the products of the reaction were analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and nuclear magnetic resonance (NMR) spectrometry. The effects of light, dissolved oxygen and chloride ion on reaction rates were also investigated. The highest reaction rates were observed in systems free of both oxygen and chloride ion with the second-order apparent rate constants of 1.2 x 10(4), 4.9 x 10(3), and 2.8 x 10(3) (L x mol(-1) x s(-1)) for oxalic, malonic, and succinic acids at pH 3.0 and T = 296 +/- 2 K, respectively. The photoreduction of Hg(II) was mediated by the complexes formed between Hg" and dicarboxylic acids, and the identified products were Hg0, hydroxycarboxylic acids and monocarboxylic acids. Our results also indicated that the presence of chloride ion significantly reduced the reduction rate by competing with the complexation of Hg" with dicarboxylic acids, while dissolved oxygen retarded the production of Hg0 by involving in the reoxidation of reduced Hg species to Hg(II). Based on our experimental results, a tentative mechanism is proposed and the potential environmental implications are discussed.     

Super-resolving random-Gaussian apodized photon sieve

A novel apodized photon sieve is presented in which random dense Gaussian distribution is implemented to modulate the pinhole density in each zone. The random distribution in dense Gaussian distribution causes intrazone discontinuities. Also, the dense Gaussian distribution generates a substantial number of pinholes in order to form a large degree of overlap between the holes in a few innermost zones of the photon sieve; thereby, clear zones are formed. The role of the discontinuities on the focusing properties of the photon sieve is examined as well. Analysis shows that secondary maxima have evidently been suppressed, transmission has increased enormously, and the central maxima width is approximately unchanged in comparison to the dense Gaussian distribution. Theoretical results have been completely verified by experiment.     

Agro‐wastes: Mechanical and physical properties of resin impregnated oil palm trunk core lumber

Agro‐wastes, oil palm trunk core or sap was utilized for the production of new palm‐wood material using phenol formaldehyde resin as a matrix. The kiln‐dried (moisture content 10%) oil palm trunk was impregnated with phenol formaldehyde resin using a high power vacuum pump. The oil palm trunk core lumber (OPTCL) was loaded with different percentages of phenol formaldehyde (PF) resin. The mechanical properties (tensile, flexural, and impact) and physical properties (water absorption and density) were studied and compared with rubberwood. Testing of mechanical and physical properties was done according to the ASTM standard. The morphology of the resin loaded OPTCL was analyzed by using Scanning Electron Microscopy (SEM). In general, the result showed that impregnated OPTCL exhibited good mechanical and physical properties when compared with untreated oil palm trunk core (OPTCL with 0% resin content) and rubberwood. Tensile and flexural strength of OPTCL increased with the increase in the resin content up to 15% and showed a decreasing trend with the increase in the loading percentage beyond 15%.The impact strength also increased with the increase in the resin content from 5% to 15%. However, impregnated OPTCL with 15% resin loading showed lower water absorption uptake as compared with the other composite materials and rubberwood. SEM micrograph confirmed that the resin was impregnated efficiently within the pores of OPTCL fibers. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

A numerical framework for heat transfer and pressure loss estimation of matrix cooling geometry in stationary and rotational states

This study conducts an investigation and feasibility study on different Reynolds numbers (6000–12000) and Rotation numbers (0.05–0.25) in a matrix cooling geometry. An intended geometry that can be used in gas turbine blades is provided based on flow and heat transfer performance given in these Reynolds and rotation number ranges for stationary and rotational state and then compared with experimental data. In this work, a 3D simulation method for each states (stationary and rotation) has been used for two layers matrix cooling with four inlets in each layer in a straight rectangular channel. The results indicate that among the common methods used in the trailing edge of a gas turbine blade, the matrix cooling method has heat transfer in stationary and rotary states ～2–3 times higher than those of a smooth channel. Also results showed that rotation significantly affects heat transfer characteristics. Heat transfer increases in the pressure-side by a factor of 3 (at a Rotation number of 0.15 and Reynolds number 6000) which is an important property of rotation. According to the specific rotation direction chosen in this study, in comparison with previous studies, the pressure side and suction side location in stationary and rotation states are different and this results in lower decrease of heat transfer in the suction side for the rotation state. It is observed that using this structure increases the thermal performance about 30% by changing the flow behavior between stationary and rotary states.