Sorption of remazol brilliant blue R onto polyurethane‐type foam prepared from peanut shell

The powders of peanut shell is first liquefied with the mixture of polyethylene glycol‐400 and monoethylene glycol (MEG) using sulfuric acid at 160°C for 2 h. Polyurethane (PU)‐type rigid foam is prepared from the reaction between peanut shell liquefied with the MEG and diphenylmethane diisocyanate. Then the PU foam is used as a sorbent for the removal of the remazol brilliant blue R from aqueous solution. The sorption of the dye increases with increasing initial concentration, temperature, and ionic strength, while decreasing with increasing pH. From the isotherm and kinetic studies, it is seen that the sorption process is in the best agreement with the Langmuir isotherm and the pseudo second‐order kinetic model. Desorption and FTIR studies show that a chemisorption process occurs between dye and foam, probably indicating electrostatic interactions. The thermodynamic parameters (i.e., standard free energy, standard enthalpy, and standard entropy) are determined, and the results obtained are discussed in detail. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci, 2013     

Electropolymerization, characterization and corrosion performance of poly(N-ethylaniline) on copper

Poly(N-ethylaniline) (PNEA) coatings were grown by cyclic voltammetry technique on copper from 0.1 M N-ethylaniline (NEA) in 0.3 M oxalic acid solution. The optimum conditions (e.g. upper potential limit, scan rate and cycle number) effect on corrosion performance of synthesized PNEA films were determined in order to obtain best protection results against corrosion. The electrodeposited coatings were characterized by cyclic voltammetry (CV), Fourier Transform Infrared-Attenuated Total Reflectance (FTIR-ATR) spectroscopy and scanning electron microscopy (SEM). Redox parameters were found after electrochemical tests and results of stability tests of these films impart an electroactive behavior that is composed of both diffusion control and thin film behavior. In addition, corrosion performance of PNEA coatings were investigated in 0.1 M H₂SO₄ by Tafel extrapolation and electrochemical impedance spectroscopy (EIS) techniques.     

Effect of waste marble dust content as filler on properties of self-compacting concrete

Day by day, the amount of the marble dust (MD) as a waste material is significantly of increasing in Turkey. Therefore, the utilization of the waste MD in self-compacting concrete (SCC), as filler material, is the main objective of this study. Besides, the MD is used directly without attempting any additional process. Thus, this would be another advantage for this objective. For this purpose, MD has replaced binder of SCC at certain contents of 0, 50, 100, 150, 200, 250 and 300 kg/m³. After then, slump-flow test, L-box test and V-funnel test are conducted on fresh concrete. Furthermore, compressive strength, flexural strength, ultrasonic velocity, porosity and compactness are determined at the end of 28 days for the hardened concrete specimens. The effect of waste MD usage as filler material on capillarity properties of SCC is also investigated. According to the test results, it is concluded that the workability of fresh SCC has not been affected up to 200 kg/m³ MD content. However, the mechanical properties of hardened SCC have decreased by using MD, especially just above 200 kg/m³ content.     

Histopathologic study of rat connective tissue responses to maxillofacial silicone elastomers

The aim of this histopathologic study was to assess and compare the subcutaneous connective tissue reaction to three different maxillofacial silicone elastomers (Cosmesil, Multisil, Episil). The test materials were directly inserted subcutaneously into the dorsal subcutaneous tissue of Wistar albino rats. Histopathological examinations were done at 7, 30, and 90 days after the implantation procedure. The presence of inflammation, presence of inflammatory giant cells, and the thickness of fibrous connective tissue adjacent to each inserted sample were recorded. Data was evaluated by analysis of variance, Wilcoxon signed ranks test and Kruskal Wallis test. Cosmesil, Multisil and Episil silicone elastomers at 7 days elicited a severe inflammatory reaction. However, these reactions decreased by the 30 and 90 days. All silicone elastomers elicited a moderate inflammatory reaction at 30 and 90 days. There were no significant differences in tissue reaction between the materials at 7, 30, and 90 days (P > 0.05). All the maxillofacial silicone elastomers evaluated can not be assigned a favorable biocompatibility level based on this study’s histologic findings.     

Use of antimicrobial methylcellulose films to control Staphylococcus aureus during storage of Kasar cheese

Olive leaf extract (OLE) (Olea europaea L.) is a natural product that has antimicrobial effect on many food pathogens. In this study, methylcellulose (MC) based antimicrobial films containing 0.5–3% (w/v) OLE and glycerol (1.6%, v/v) were produced. The effects of OLE amount on the water vapour permeability (WVP), mechanical and antimicrobial properties of the films were investigated. The films were effective against Staphylococcus aureus (ATCC 25923). The OLE in the film solution caused a decrease in WVP and elongation (E), and an increase in tensile strength (TS). The MC films containing 1.5% (w/v) OLE were applied on Kasar cheese slices inoculated with S. aureus. The count of S. aureus decreased 0.68 and 1.22 log cycle at the 7th and 14th days, respectively. Copyright © 2009 John Wiley & Sons, Ltd.     

Comparison of the dielectric and viscoelastic properties of two poly (propylene glycol) liquids

The complex relative permittivities of two poly(propylene glycol) liquids, of molecular weights 380 and 3030, have been determined. Measurements were made in the frequency range 60 Hz to 200 MHz and at temperatures from ?64° to +25°C. The lower molecular weight liquid showed only one relaxation region, which could be described by the Williams-Watts function with $\text{}\text{?}\text{gb = 0.51}$. The higher molecular weight liquid exhibited a similar main relaxation region and a secondary relaxation, of smaller amplitude, at lower frequencies. The relaxation times and their temperature dependencies are compared with previously determined viscoelastic relaxation and retardation times for the same liquids, and with the results from earlier dielectric studies by Baur and Stockmayer, and by Williams. The differences between the dielectric and mechanical times are discussed.     

Passive control of liquid water storage and distribution in a PEFC through flow-field design

Liquid water stored in the diffusion media (DM) in a polymer electrolyte fuel cell (PEFC) can dramatically impact steady and transient performance, degradation, and heat transfer. In this study, seven different flow-field designs, with landing-to-channel (L:C) ratio from 1:3 to 2:1, were investigated at dry and fully humidified conditions, using neutron imaging. The results revealed the impact of flow-field geometry on stored liquid overhead is significant. In some cases, the stored water content in the cell can be nearly double that of another design, despite similar performances at low to medium current density. In general, a smaller L:C ratio reduces flooding losses and minimizes the stored water content. Additionally, the channel–DM interface plays a key role. For the same L:C ratio, a reduced number of channel–DM interfaces was shown to reduce flooding and stored liquid water content at steady state. This also suggests that using proper flow-field design can decrease the parasitic power consumption and the stored water content in the cell without any sacrifice from the cell performance. For dryer operating conditions, however, membrane dehydration becomes a dominant effect and a high landing-to-channel ratio flow-field is higher performing.