Synthesis and properties of oxalic acid-doped polyaniline

Conductive polyaniline was synthesized in aqueous 1.0M oxalic acid containing 0.1 M aniline by electrochemical and chemical oxidation and characterized by conductivity, solubility, ultraviolet and infrared spectroscopy, and cyclic voltammetry. The solubility experiments showed that the solubility of oxalic acid-doped polyaniline in dimethylsulfoxide and dimethylformaide increased to a certain extent. The soluble part of the polyaniline was free from impurities such as quinones. Cyclic voltammetric studies in oxalic acid medium revealed that aniline exhibited a similar behaviour to that in H₂SO₄ and the polymerization rate was much slower than that in H₂SO₄.     

Study of the electron densities of some food products dried using the new method

The main goal of this study was to determine the concentrations of P, S, Cl, K, Ca, and Sr in food samples using a newly developed drying method to find their electron densities. The methods applied to samples to find the effective drying method were as follows: “drying in oven under a magnetic field” and “drying under the sun and a magnetic field.” Concentrations of elements were determined by an energy dispersive X-ray fluorescence spectrometer soon after initial processing of dried foods. The concentrations of elements were acquired as mg/kg. An attempt was made to calculate the electron densities of the dried samples. The electron densities of food samples dried in oven under a magnetic field as the effective one were identified using ZXCOM software. This particular attempt is fairly new, and there is no information in this field. The electron density (N_eff) values of the dried samples were calculated for all samples of interest. The electron densities of fig samples dried with the new method suggested in this study were found to be highest among all samples of interest.     

Investigation on colour,fastness properties and HPLC‐DAD analysis of silk fibres dyed with Rubia tinctorium L. and Quercus ithaburensis Decaisne

Silk fabric samples were dyed according to the various procedures using madder (Rubia tinctorium L.) and walloon oak (Quercus ithaburensis Decaisne) extracts. The colour coordinates, K/S, as well as wash, light, rub and perspiration fastness values were determined. A reversed‐phase high‐performance liquid chromatography with diode‐array detection was utilised for the identification of the components of dyes present in the dyed fabrics and in the plant extracts.     

The effect of plasma electrolytic oxidation process parameters on the tribocorrosion properties of TiO2 coatings

Despite the fact that Titanium and its alloys are materials which have excellent corrosion-resistant properties, they have poor wear and friction performance under tribological conditions. The aim of this study is to find suitable parameters for the surface treatment of Cp-Ti substrates which are used under saline environment. In this study, TiO₂ coatings were grown on Cp-Ti substrates at different frequencies which are parameters of the coating process. Due to its low cost and ability to achieve high thicknesses, The Plasma Electrolytic Oxidation (PEO) method was applied to grow TiO₂ coatings. The microstructures, morphology, and crystallographic structure were analyzed using SEM and XRD. Tribocorrosion properties of the coatings were investigated using a combination of the pin-on-disk wear test and potentiodynamic polarization test units. The frequency is known to have a strong impact on the PEO process. The impacts of frequency changes on the PEO coating performance were examined under a constant voltage. As result, the increase of the frequency caused smaller pores and cracks in the surface morphology of the coating and at the same time this yielded an increment on the tribocorrosion behavior of the coating.     

The assessment of a roof drainage system for an historical building

Roof drainage systems of historical buildings no longer serving effectively under existing conditions should be repaired according to maintenance programs developed specifically for them through a study of their characteristics, discharge capacities, faults and the climatic conditions prevailing in their environs. The studies necessary for this should ideally be done using non-destructive methods. Such a study was conducted on the roof of a 13th century stone monument, “Agˇz?karahan”, in Aksaray, Turkey, to assess its overall drainage adequacy and its potential for taking corrective action. Results showed that the roof was originally configured to provide a proper peripheral drainage system. However, it fails at present due to earlier incorrect interventions and subsequent lack of maintenance. Suggestions were made on urgent remedial interventions, preventive measures and future improvements.     

Microstructure and Mechanical Effects of Co–Ti Powder Particles on Cu Matrix Composites

Russian Journal of Non-Ferrous Metals - Powder metallurgy was used in this study. High purity cobalt and titanium powders were added to copper powders at a ratio of 5–10–15 wt %. The...     

Thermal denaturation and functional properties of egg proteins in the presence of hydrocolloid gums

The aim of this study was to investigate the thermal stability, foaming and emulsifying properties of egg white and egg yolk constituents (egg yolk plasma and egg yolk granule) in the presence of hydrocolloid gums. Differential scanning calorimetry was used to examine the thermal stability of proteins. Heat denaturation of proteins were not influenced from the presence of anionic pectin and i-carrageenan and neutral guar gum. The residual denaturation enthalpy was observed to decrease as a result of protein aggregation. Thermal treatment have been observed to be detrimental to foaming capacity of egg white, while foam stability was improved. The foam stability was enhanced in the presence of pectin which may provide a strong viscoelastic film together with protein. Emulsifying activity and stability and of egg yolk granule and plasma were reduced after heat treatment. The presence of guar gum improved the emulsifying properties, while both pectin and guar gum reduced the rate and extend of creaming of egg yolk protein – stabilized proteins after heat treatment.     

Effect of extrusion process on the antioxidant activity and total phenolics in a nutritious snack food

The effect of screw speed (220–340 rpm), moisture content of the feed (11.0–15.0%, wet base) and feed rate (22.0–26.0 kg h^?1, wet base) on the total antioxidant capacity (TAA) and concentration of total phenolics (TP) in a nutritionally balanced extruded snack were investigated. Regression equations describing the effect of each variable on the responses were obtained. Results indicated that screw speed, moisture content of the feed and feed rate had an effect on the TAA values of the samples at 95% confidence interval (CI). The interaction between the three factors was also found to be significant at 95% CI for TAA values. Extrusion conditions applied in this study did not change the TP values in the samples. The TAA value of samples decreased with an increase in screw speed and decrease in moisture content.