Effects of atmospheric plasma treatment on the dyeability of cotton fabrics by acid dyes

Cotton fabrics were treated with air and argon atmospheric plasma for surface activation. Activated surfaces were grafted with two different amine compounds: ethylenediamine and triethylenetetramine. Pretreated cotton was dyed with acid dye and the effects of pretreatment on the colour strength, as well as the washing, rubbing and the light fastness of the dyeings, were investigated. Colour yield results showed that grafted ethylenediamine and triethylenetetramine enhance the dyeability of cotton fabric with acid dyes. Fourier transform infrared spectra confirmed the formed groups on the surface and scanning electron microscopy showed the etching effect of plasma.     

Self-organization of nanometer periodic structures of clusters in solids

The formation of non-uniform spatial structures in irradiated solids (metals, semiconductors) is investigated, when the subsystem of nonequilibrium lattice defects (vacancies and interstitials) forms bonded states, nanoclusters. A set of kinetic equations is formulated which incorporates, (i) generation of point defects by radiation, (ii) their diffusion and recombination, (iii) mutual pairwise elastic interaction among defects, (iv) formation and growth of the nanoclusters of point defects, and (v) losses of the nanoclusters due to removal from the nucleation zone by diffusion. Linear stability analysis is used to show that, if the temperature (T) of medium is below a critical value (Ter), due to the elastic interaction the homogeneous distribution of point defects and their clusters becomes unstable, and a periodic structure of a nanometer scale arises. The criterion of self-organization of the clusters and the dependence of a super-lattice period on temperature of medium are determined analytically. The critical temperature for self-organization of periodic structures is governed by the dilatation volume of defects, by the potential energy of elastic interaction, and the concentration of defects. Estimations showed that the period of super-lattices may change in the range of (20-80) nm. Obtained results agree with the experimental data.     

Relationships derived from physical properties of vegetable oil and biodiesel fuels

The aim of this study was to estimate mathematical relationships between higher heating value (HHV) and viscosity, density or flash point measurements of various biodiesel fuels. The HHV is an important property defining the energy content and thereby efficiency of fuels, such as vegetable oils and biodiesels. The biodiesels were characterized for their physical and main fuel properties including viscosity, density, flash point and higher heating value. The viscosities of biodiesels (2.8–5.1 mm²/s or cSt at 311 K) were much less than those of pure oils (23–53 mm²/s at 311 K), and their HHVs of approximately 41 MJ/kg were 10% less than those of petrodiesel fules (～46 MJ/kg). Compared to No. 2 diesel fuel, all of the vegetable oil methyl esters were slightly viscous. The density and flash point values of vegetable oil methyl esters are highly lower than those of vegetable oils. The HHVs of vegetable oils and their biodiesels were measured and correlated using linear least square regression analysis. There is high regression between viscosity and higher heating value for vegetable oil and biodiesel samples. An increase in density from 848 to 885 g/L for biodiesels increases the viscosity from 2.8 to 5.1 cSt and the increases are highly regular. There is high regression between density and viscosity values vegetable oil methyl esters. The relationships between viscosity and flash point for vegetable oil methyl esters are considerably regular.     

Electrospun nanofibers from cyclodextrin inclusion complexes with cineole and p‐cymene: enhanced water solubility and thermal stability

The electrospinning of self‐standing nanofibrous webs from inclusion complexes (IC) of cineole and p‐cymene with two modified cyclodextrins (HPβCD, HPγCD) was achieved without using carrier polymeric matrix. Although they are highly volatile, certain amount of cineole and p‐cymene was protected in cyclodextrin inclusion complexes nanofibers (CD‐IC‐NF). That is, 68.4%, 78.1%, 54.5% and 44.0% (w/w) of active agent were preserved in cineole/HPβCD‐IC‐NF, cineole/HPγCD‐IC‐NF, p‐cymene/HPβCD‐IC‐NF and p‐cymene/HPγCD‐IC‐NF, respectively. Remarkable, high thermal stability for cineole (~150 °C – 270 °C) and p‐cymene (~150 °C – 275 °C) was achieved for CD‐IC‐NF samples due to CD‐IC formation. The water solubility of cineole and p‐cymene was significantly improved by inclusion complexation where CD‐IC‐NF samples become readily dissolved in water. In brief, essential oils and flavours such as cineole and p‐cymene could be applicable in food and oral care applications owing to their fast‐dissolving behaviour along with high water solubility, enhanced thermal stability and free‐standing feature of CD‐IC‐NF webs.     

Thermal,mechanical, and morphological characterization studies of poly(2,6‐dimethyl‐1,4‐phenylene oxide) blends with polystyrene and brominated polystyrene

The miscibility of the binary and ternary blends of poly(2,6‐dimethyl‐1,4‐phenylene oxide), brominated polystyrene, and polystyrene was investigated using a differential scanning calorimeter. The morphology of these blends was characterized by scanning electron microscopy. These studies revealed a close relation between the blend structure and its mechanical properties. The compatibilizing effect of poly(2,6‐dimethyl‐1,4‐phenylene oxide) on the miscibility of the polystyrene/brominated polystyrene blends was examined. It was found that poly(2,6‐dimethyl‐1,4‐phenylene oxide), which was miscible with polystyrene and partially miscible with brominated polystyrene, compatibilizes these two immiscible polymers if its contention exceeds 33 wt %. Upon the addition of poly(2,6‐dimethyl‐1,4‐phenylene oxide) to the immiscible blends of polystyrene/brominated polystyrene, we observed a change in the morphology of the mixtures. An improvement in the mechanical properties was noticed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 225–231, 2000     

Drying and conservation conditions of pollen

In this study, drying and conservation conditions of pollens (for Anzer Honey) were experimentally investigated, and the general drying curve equation was derived by applying the Least Squares Method. Drying experiments were conducted in solar‐ and electric‐assisted dryers. Pollens were placed on the shelves as 50 each g in a single layer having a depth of 2.5 mm. During the drying experiments, the shelf temperatures of the drying cupboard were regulated between 40 °C and 45 °C. Weight losses, moisture contents and mass shrinkage of pollens and average temperatures in the shelves were determined and calculated based on drying time. Additionally, the experimental uncertainty values were calculated as approximately 18%, depending on the experimental results. It was concluded that pollens should be dried at temperatures between 40 °C and 45 °C for between 2.5 and 3 h so as not to change the colour, flavour, smell and structure, and conserved in brown bottles under vacuum in a shady medium. © 2000 Society of Chemical Industry     

Development and in vitro/in vivo evaluation of dihydroergotamine mesylate loaded maltodextrin-pullulan sublingual films

Dihydroergotamine mesylate (DHE), ergotamine derivative, has been offered for clinical use to stop or treat symptoms of an emerging migraine as injection for more than a half century. It is shown that bioavailability of DHE greatly changes between the subjects and up to 99% of the orally absorbed dose may be cleared by first pass metabolism. The aim of this study was to design and optimize DHE fast-dissolving sublingual films for migraine treatment. For this purpose pullulan and maltodextrin was chosen as film-forming polymers and propylene glycol as plasticizer. For optimization process Box Behnken design was used. The formed films were free from air bubbles, cuttings, or cracks. Disintegration, mechanical strength and dissolution of films were compared. It is found that pullulan and maltodextrin formed films with the most desired properties at the concentration of 1.5% and 2%. The application of optimum formulation to rabbits showed that bioavailability of formulation is about 23.35% with a t_max 20?min. Due to this fast onset of action and higher bioavailability than oral administration, it is suggested that the polymer combinations of pullulan and maltodextrin formed successful films and were considered as an alternative dosage form for DHE in migraine therapy.     

Oxidative changes in hazelnut,olive, soybean,and sunflower oils during microwave heating

The effects of microwave heating for 3, 6, and 9 min at a frequency of 2450 MHz on fatty acid composition, tocopherols, iodine value, free fatty acids (%), peroxide value, conjugated dienes and trienes, and hexanal contents of refined hazelnut, soybean, sunflower, and virgin olive oils were investigated. A significant (p < 0.05) decrease was observed in linoleic and linolenic acids contents of soybean oil during exposure to microwave heating. Tocopherol contents of oil samples significantly decreased (p < 0.05) during microwave heating. Free fatty acids of the samples slightly increased and iodine value showed reduction throughout the process. Conjugated dienes contents of samples showed an increasing trend up to the 6 min, followed by a reduction at 9 min. Conjugated triene fatty acids of all the samples significantly increased (p < 0.05) throughout the application. While peroxide value showed increasing trend up to the 3 min and sharply decreased at 9 min, hexanal contents of refined hazelnut, virgin olive, soybean, and sunflower oils increased 63, 28, 55, and 389 fold, respectively, after 9 min exposure to microwave heating. Kinetic analysis of data showed that the reaction orders for peroxide and hexanal formation were zero and first order, respectively, and in the tested oils the reaction rate followed the order: soybean oil ? sunflower oil ? hazelnut oil ? virgin olive oil for peroxide, and sunflower oil ? soybean oil ? hazelnut oil ? virgin olive oil for hexanal formation. It was concluded that hexanal could be considered as a parameter for evaluation of the quality of oils exposed to microwave heating.     

Metabolic activities of Lactobacillus spp. strains isolated from kefir

A total of 21 strains of Lactobacillus species were isolated from Turkish kefir samples, in order to select the most suitable strains according to their metabolic activities including probiotic properties. As a result of the identification tests, 21 Lactobacillus isolates were identified as L. acidophilus (4%), L. helveticus (9%), L. brevis (9%), L. bulgaricus (14%), L. plantarum (14%), L. casei (19%) and L. lactis (28%). The amount of produced lactic acid, hydrogen peroxide, proteolytic activity, and acetaldehyde productions of Lactobacillus spp. were determined. Different amounts of lactic acid were produced by strains studies; however, lactic acid levels were 1.7-11.4 mg/mL. All strains produced hydrogen peroxide. L. bulgaricus Z14L strain showed no proteolytic activity, L. casei Z6L strain produced the maximum amount (0.16 mg/mL) of proteolytic activity. Acetaldehyde concentration produced in Lactobacillus strains ranged between 0.88-3.52 microg/mL.