A simplified equation of state for polymer melts from perturbed Yukawa hard-sphere chain

This paper addresses the modeling of the pressure?Cvolume?Ctemperature (PVT) properties of 14 polymer melts using simplified Yukawa hard-sphere-chain equation of sate (EOS) plus first-order perturbation theory. Three pure-component parameters appeared in the EOS have been determined via the volumetric data. These parameters reflect the segment number, non-bonded segment?Csegment interaction energy, and segment size. Likewise, this study considered chains that interact through a range-parameter of Yukawa potential with l.8. The reliability of the proposed model has been assessed by comparing the results with 1,315 experimental data points over a broad range of pressures and temperatures for which, their measured values were available in the literature. Our calculations on the specific volume of studied liquid polymers reproduce very accurately the experimental PVT data. The overall average absolute deviation of the calculated specific volumes from literature data was found to be 0.89?%.     

Polybutadiene/polyhedral oligomeric silsesquioxane nanohybrid: investigation of various reactants in polyesterification reaction

Nano‐sized polyhedral oligomeric silsesquioxane (POSS) diol or ethylene glycol (EG) as diol monomer was incorporated into hydroxyl‐terminated polybutadiene (HTPBD) chain in the presence of fumaryl or thionyl chloride as extenders. Using these polyesterification reactions, two fumarate‐based polyesters and two polyester sulfites were synthesized. Each couple of polyesters and polyester sulfites includes a linear (diol:EG) and a nanohybrid macromer (diol:POSS). Full structural characterization was performed using Fourier transform infrared, ¹H NMR and ¹³C NMR spectroscopies. Gel permeation chromatography was undertaken to study polyesterification mechanisms by deconvolution of the obtained traces. Finally, differential scanning calorimetry, thermogravimetric analysis and cell culture were performed to evaluate the structure–property relationship for the synthesized macromers in comparison with unreacted HTPBD. © 2016 Society of Chemical Industry     

Effect of pulsed ultrasound treatment compared to continuous mode on microbiological and quality of Mirabelle plum during postharvest storage

The effects of pulsed and continuous ultrasound treatment on microbiological and physiological quality of Mirabelle plum fruit were investigated. Freshly harvested Mirabelle plum was treated with 30‐kHz pulsed and continuous ultrasound at 20 °C for 0, 15, 30, 45 and 60 min and subsequently stored at 4 °C for 10 days. The total count of bacteria, total fungi, decay index, titratable acidity (TA), total soluble solids (TSS), colour, texture, ascorbic acid content and total phenolics was measured. The results showed that pulsed and continuous ultrasonic treatment significantly (P < 0.05) reduced the number of microorganisms and improved the quality of Mirabelle plums during storage. Increasing pretreatment time enhanced the positive effects of pulsed and continuous ultrasound. Also, in terms of the total count of bacteria, total fungi, titratable acidity and total phenolics, the pulsed and continuous ultrasound did not show a significant difference (P < 0.05). However, pulsed ultrasound was better compared to continuous mode in preservation of TSS, colour, texture and ascorbic acid content of the fruit during storage. Our results demonstrated that pulsed ultrasound is an appropriate method for improving safety and maintaining the quality of Mirabelle plum fruit.     

Nanoscale mass nanosensor based on the vibration analysis of embedded magneto-electro-elastic nanoplate made of FGMs via nonlocal Mindlin plate theory

Microsystem Technologies - In the current paper, the sensitivity performance of functionally graded magneto-electro-elastic (FG-MEE) nanoplate with attached nanoparticles as a nanosensor is...     

The effect of pressure on removal of carbon monoxide in biofilter

Solubility of carbon monoxide in water is very important for its biological oxidation or removal process of gaseous pollutants. Present research shows the effect of pressure on solubility of carbon monoxide in liquid phase and its removal process by a biofilter. The results are considered as laboratory research on carbon monoxide elimination. In this method a pressurized trickle-bed biofilter was used to increase pressure in the reactor. The biofilter was filled with Leca-stones and inoculated with microorganisms. When the system’s pressure is increased, the solubility of carbon monoxide will be increased, respectively, and it causes a better reaction of the microorganisms for removing of gaseous pollutants. The efficiency was improved significantly by increasing the pressure in the reactor.     

Discussion on “Enhancement of combined heat and power economic dispatch using self adaptive real-coded genetic algorithm,by P. Subbaraj et al., Applied Energy 86 (2009) 915–921.”

The paper studied by Subbaraj et al. (2009) considers the feasibility of using self adaptive real-coded genetic algorithm for enhancement of combined heat and power economic dispatch. The paper includes some problems about the considered feasible operating region. In this discussion, the controversial point of the paper are given.     

Numerical Simulation of the Mechanical Properties of Sintered and Bonded Perforated Hollow Sphere Structures (PHSS)

This paper investigated the uniaxial mechanical properties of a new type of hollow sphere structures. For this new type, the sphere shell was perforated by several holes in order to open the inner sphere volume and surface. The mechanical properties, i.e. elastic properties and initial yield stress of perforated hollow sphere structures (PHSS) in a primitive cubic arrangement were numerically evaluated for different hole diameters and different joining techniques of the hollow spheres. The results are compa...     

Chemisorption,physisorption and hysteresis during hydrogen storage in carbon nanotubes

The question of chemisorption versus physisorption during hydrogen storage in carbon nanotubes (CNTs) is addressed experimentally. We utilize a powerful measurement technique based on a magnetic suspension balance coupled with a residual gas analyzer, and report new data for hydrogen sorption at pressures of up to 100 bar at 25 °C. The measured sorption capacity is less than 0.2 wt.%, and there is hysteresis in the sorption isotherms when multi-walled CNTs are exposed to hydrogen after pretreatment at elevated temperatures. The cause of the hysteresis is then studied, and is shown to be due to a combination of weak sorption – physisorption – and strong sorption – chemisorption – in the CNTs. Analysis of the experimental data enables us to calculate separately the individual hydrogen physisorption and chemisorption isotherms in CNTs that, to our knowledge, are reported for the first time here. The maximum measured hydrogen physisorption and chemisorption are 0.13 wt.% and 0.058 wt.%, respectively.