Miscibility and tack of blends of poly (vinylpyrrolidone)/acrylic pressure-sensitive adhesive

In this study, miscibility and tack of blends of poly (vinylpyrrolidone) (PVP)/acrylic pressure-sensitive adhesive (PSA) were evaluated. For this purpose, appropriate amounts of PVP (2–30% w/w) were added to an acrylic PSA to obtain visually homogeneous solution. The resulting solution was evenly applied on a polyethylene terephthalate (PET) film with final specific thicknesses of 10, 40, and 70 μm by using a film applicator and miscibility as well as tack values were evaluated. With the addition of 2% (w/w) PVP the tack value decreased and increased in 5% (w/w) PVP and then continuously decreased up to 30%(w/w). It was found that the tack value was related to miscibility as well as to viscosity and the free functional group such as hydroxyl group of the blend. By the morphological analysis performed through scanning electron microscopy (SEM) and also by the study of thermal analysis using the differential scanning calorimetry (DSC) behavior of blends, it was found that the two distinct phases constituted after adding 5% (w/w) of PVP. This resulted in the acrylic PSA forming the continuous phase, and by increasing the concentration of PVP a dispersed phase was developed. The dispersed phase has a higher viscosity than the continuous phase and therefore cannot wet the adherent and hence result in lowering the tack values.     

Ion-exchange kinetics and thermal decomposition characteristics of Fe2+-exchanged alginic acid membrane for the formation of iron oxide nanoparticles

The ion-exchange kinetics of Fe²⁺ cations in aqueous solution with H⁺ from alginic acid have been analyzed in this study as a function of contact time lengths using inductively coupled plasma-atomic emission spectrometry analysis. The kinetic parameters have been evaluated using pseudo 1st or 2nd order models, and a consistent ion-exchange mechanism is suggested. Furthermore, an insight into the calcination of Fe²⁺ ion-exchanged alginic acid process has been obtained by using simultaneous thermo-gravimetric analysis coupled with differential scanning calorimetry and high temperature X-ray diffraction.     

Using Taguchi method to determine optimum process conditions for flue gas desulfurization through an amine scrubber

This study was done to determine the optimum process conditions for absorption of sulfur dioxide in a mixture of flue gases. Using a selective amine-based absorber; a high amount of SO₂ was absorbed in the scrubbing process. The process was designed to reduce the amount of sulfur dioxide. The pilot plant was designed and set up in the Research Center of Petroleum University of Technology, containing absorption and desorption stages. This paper reports an investigation of the effect and optimization of parameters that improve the efficiency of the whole process. The experiments were conducted under varying levels of desorption temperature, pH of the absorber solution, concentration of SO₂ inlet gas, and flow rate of the absorbing solution. Using Taguchi experimental design method, the optimum conditions were identified for the absorption process. An efficiency of more than 99 % could be obtained by varying the parameters in which all the released SO₂ gas was absorbed from the inlet flue gas; an achievement that is much favorable for industrial purposes.     

Prediction of geological hazardous zones in front of a tunnel face using TSP-203 and artificial neural networks

This research aims at improving the methods of prediction of hazardous geotechnical structures in the front of a tunnel face. We propose and showcase our methodology using a case study on a water supply system in Cheshmeh Roozieh, Iran. Geotechnical investigations had previously reported three measurements of the newly established method of TSP-203 (Tunnel Seismic Prediction) along 684 m of the 3200 m long tunnel up to a depth of 600 m. We use the results of TSP-203 in a trained artificial neural network (ANN) to estimate the unknown nonlinear relationships between TSP-203 results and those obtained by the methods of Rock Mass Rating classification (RMR – treated here as real values). Our results show that an appropriately trained neural network can reliably predict the weak geological zones in front of a tunnel face accurately.     

Development of an efficient stabiliser mixture for physical stability of nonfat unfizzy doogh

The effects of locust bean, carboxymethyl cellulose, a mixture of locust bean and carboxymethyl cellulose and Persian gum on different properties of nonfat doogh were studied over a period of 28 days. The results showed that samples containing a mixture of locust bean and carboxymethyl cellulose had the highest stability. Furthermore, the rheological behaviour of the doogh changed from Newtonian to pseudoplastic. Better sensory acceptability was shown for the treatments containing a mixture of locust bean gum and carboxymethyl cellulose. In general, it was shown that a mixture of locust bean and carboxymethyl cellulose could be of practical use in the industrial production of nonfat doogh.     

Antioxidant Activity of Loquat (Eriobotrya japonica Lindl.) Fruit Peel and Pulp Extracts in Stabilization of Soybean Oil During Storage Conditions

The antioxidation activities of Eriobotrya japonica (Lindl.) fruit peel and pulp extracts were determined using DPPH, β-carotene, and Rancimat methods. Results showed that ethanol-water extract of peel and ethanol extract of pulp had the highest antioxidant activity. Protective effects of extracts in stabilization of soybean oil were tested and compared to tert-butyl hydroquinone by measuring peroxide values, free fatty acids, thiobarbituric acid, oxidative stability, and conjugated dienes and trienes values during storage (65 days at 25°C). Results showed that the ethanol-water extract of peel at 400 ppm exhibited stronger antioxidant activity, but the highest effect was observed in tert-butyl hydroquinone.     

Numerical simulation of direct methanol fuel cells using lattice Boltzmann method

In this study Lattice Boltzmann Method (LBM) as an alternative of conventional computational fluid dynamics method is used to simulate Direct Methanol Fuel Cell (DMFC). A two dimensional lattice Boltzmann model with 9 velocities, D2Q9, is used to solve the problem. The computational domain includes all seven parts of DMFC: anode channel, catalyst and diffusion layers, membrane and cathode channel, catalyst and diffusion layers. The model has been used to predict the flow pattern and concentration fields of different species in both clear and porous channels to investigate cell performance. The results have been compared well with results in literature for flow in porous and clear channels and cell polarization curves of the DMFC at different flow speeds and feed methanol concentrations.     

Prioritizing of wind farm locations for hydrogen production: A case study

Many advantages of renewable energies, especially wind energy, such as abundance, permanence, and lack of pollution has encouraged many industrialized and developing countries to focus more on these clean and economic sources of energy. Identifying a good location that is suitable for the construction of a wind farm is one of the important initial steps in harnessing wind energy which is assessed this study. The purpose of this study is to prioritize and rank 13 cities of Fars province in Iran, in terms of their suitability for the construction of a wind farm. Six important criteria were used to prioritize and rank the cities. Wind power density is the most important criterion among these criteria which is calculated by obtaining the 3-h wind speed data between 2004 and 2013. DEA (Data Envelopment Analysis) method is used for prioritizing and ranking cities, and then AHP (Analytical Hierarchy Process), and FTOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) methods are used to assess the validity of results. It is concluded that Izadkhast city is the suggested location for the construction of wind farm. The utilizing a wind-hydrogen energy conversion system will result in a substantial amount of hydrogen production (averagely 21.9 ton/year) when a 900 kW wind turbine is installed in this location.