Aqueous solubility and alkaline hydrolysis of the novel high explosive hexanitrohexaazaisowurtzitane (CL-20)

The recently developed polycyclic nitramine CL-20 is considered as a possible replacement for the monocyclic nitramines RDX and HMX. The present study reports aqueous solubility data for CL-20, as well as the kinetic parameters for its alkaline hydrolysis with sodium hydroxide below and above its solubility limits. Aqueous solubility of CL-20 was measured in the temperature range of 4–69 °C and the data were fitted to a generalized solubility model. Alkaline hydrolysis experiments were conducted at 15, 20, 30 and 40 °C, with hydroxide concentrations ranging from 0.25 to 300 mM. Like RDX and HMX, alkaline hydrolysis of CL-20 follows second-order kinetics. CL-20 alkaline hydrolysis was found to proceed at a significantly faster rate than RDX. The temperature dependency of the second-order rate constants was evaluated using the Arrhenius model. The activation energy for CL-20 was found to be within close range of the activation energies reported for RDX and HMX.     

Development and properties of advanced composites based on cork and nanometric silicon carbide-filled phenolic resin

This paper presents the obtaining of advanced materials based on cork powder as reinforcement and phenolic resin (PR) with silicon carbide (nSiC) nanofiller as matrix with potential applications in aerospace industry. Three formulations were obtained: one control sample PR/cork with no nanofiller, two nanofilled samples with 1 and 2 wt% nSiC loadings into the resin. The materials were tested by flexural and compressive mechanical tests to determine their strength and stiffness, to determine their friction coefficient by tribological tests, to determine their thermal decomposition behaviour by TG-DSC analysis and to evaluate their thermal behaviour by thermal shock tests when subjected to extreme temperature directly from room temperature. The material structure was analysed by SEM visualizing the fracture cross-section after mechanical testing. The test results illustrate that silicon carbide nanoparticles improve flexural and compressive strength, but also stiffness and friction coefficient, delay thermal decomposition onset and improve thermal shock resistance. All these sustain the PR/nSiC/cork materials as potential advanced materials candidates for thermal protection applications.     

Electrical and photovoltaic properties of Cr/Si Schottky diodes

The electrical properties of the Cr/p-Si(111) and Cr/n-Si(100) junctions were investigated through capacitance–voltage and current–voltage measurements, performed under dark and light conditions at room temperature. Diode parameters of Cr/Si Schottky diode like ideality factor and barrier height were obtained and variations of them were monitored as a function of temperatures. Also, an attempt to explore the governing current flow mechanism was tried. The reverse biased I–V measurement under illumination exhibited anomalous behavior as well as high photosensitivity. The former was explained in terms of minority carrier injection phenomenon. The photovoltaic parameters, such as open circuit voltage and short circuit current were obtained as 370 mV and I_sc = 44.5 μA, respectively.     

Determination of Physicochemical Properties,Fatty Acid,Tocopherol, Sterol,and Phenolic Profiles of Expeller–Pressed Poppy Seed Oils from Turkey

In this study, the aim was to characterize the physicochemical properties and some bioactive compounds of expeller-pressed oils of five registered poppy seed varieties (TMO–1, Ofis–8, Ofis–96, Ofis–95, Ofis–3) grown in Turkey. The amounts of total carotenoids, chlorophylls, phenols, and antioxidant activities of oils ranged between 0.08–0.24 mg 100 g⁻¹, 0.03–9.04 mg pheophytin a kg⁻¹, 3.41–8.57 mg gallic acid equivalent 100 g⁻¹, and 5.60–7.33 mM Trolox equivalent 100 g⁻¹, respectively. The most abundant fatty acid in poppy seed oils was linoleic acid (69.85–74.02%), followed by oleic acid (13.98–16.99%), and palmitic acid (8.51–9.75%). In addition, poppy seed oils were rich in β–sitosterol (133.47–153.42 mg 100 g⁻¹), campesterol (45.36–58.60 mg 100 g⁻¹), and δ–5–avenasterol (28.21–39.40 mg 100 g⁻¹). High amounts of γ–tocopherol and α–tocopherol were detected. This research is the first study, which identified and quantified the polyphenol, β–carotene, and lutein compounds of expeller–pressed poppy seed oils by HPLC. Tyrosol, apigenin, syringic acid, 3–hydroxytyrosol, luteolin, p–coumaric acid, quercetin, ferulic acid, sinapic acid, and veratric acid were detected in expeller-pressed poppy seed oils.     

Identification of bioactive compounds and total phenol contents of cold pressed oils from safflower and camelina seeds

The compositions of fatty acids, tocopherols, polyphenols, sterols, and the total phenol contents of cold pressed oils obtained from five varieties of safflower seeds and ten varieties of camelina seeds cultivated in Turkey were determined. Total phenol contents of safflower oils were higher (272.20–525.30 mg GAE/kg) than camelina seed oils (25.90–63.70 mg GAE/kg). Apigenin, luteolin, tyrosol, syringic acid, 3-hydroxytyrosol, p-coumaric acid and sinapic acid were detected in seed oils. Camelina seed oils were rich in tocopherol (144.11–168.69 mg/100 g). γ-Tocopherol was the predominant tocopherol in camelina seed oils consisting of averagely 80% of total tocopherol, while α-tocopherol was the main compound of safflower seed oils, representing 97.85–98.53% of total tocopherols. β-Sitosterol was the major sterol in both type of seed oils. Its concentration ranged between 92.51–121.83 mg/100 g and 80.52–25.54 mg/100 g in safflower seed and camelina oils, respectively. Camelina seed oils contained 22.31–26.57% linolenic acid, 21.25–24.05% linoleic acid and 19.46–21.47% oleic acid, whereas safflower seed oils mainly consisted of linoleic (28.03–76.85%) and oleic (13.01–62.61%) acids.     

Detection of porcine DNA in gelatine and gelatine-containing processed food products-Halal/Kosher authentication

A commercially available real-time PCR, based on a multi-copy target cytochrome b (cyt b) using porcine specific primers, has been validated for the Halal/Kosher authentication of gelatine. Extraction and purification of DNA from gelatine were successfully achieved using the SureFood® PREP Animal system, and real-time PCR was carried out using SureFood® Animal ID Pork Sens kit. The minimum level of adulteration that could be detected was 1.0% w/w for marshmallows and gum drops. A small survey was undertaken of processed food products such as gum drops, marshmallows and Turkish delight, believed to contain gelatine. Of fourteen food products from Germany, two samples were found to contain porcine gelatine, whereas of twenty-nine samples from Turkey twenty-eight were negative. However, one product from Turkey contained porcine DNA and thus was not Halal, and neither was the use of porcine gelatine indicated on the product label.     

Effect of Soymilk Substitution on the Rheological and Sensory Properties of Salep (Traditional Turkish Milk Beverage)

Soymilk mixed at a proportion of 0%, 25%, 50%, and 75% (g/100 g total milk) with cow's milk to make a salep, a beverage prepared from the dried tubers of Orchis mascula. The values of the flow behaviour index, n, of salep samples decreased as the soymilk content in the beverage increased. All salep beverages exhibited a pseudoplastic behaviour. Among the samples, salep beverage containing 25% soymilk was scored the highest in terms of overall acceptance by sensory panellists. Statistically significant (p < 0.05) differences were determined for colour, odour, taste, mouthfeel, and overall acceptance as the concentration of soymilk increased in salep beverage. This study produced a beverage from cow's milk and soymilk to offer a promising nutritious and healthy alternative to the consumers with a reasonable acceptance. The rheological parameters of the cow's milk-soymilk salep blends obtained in this study may have useful implications for design and processing.     

Heavy metal levels in leafy vegetables and some selected fruits

The aim of this study was to determine the levels of Cu, Zn, Fe, Pb and Cd in various fruits (tomato, cherry, grape, strawberry) and vegetables (parsley, onion, lettuce, garlic, nettle, peppermint, rocket, spinach, dill, broad bean, chard, purslane, grapevine leaves) grown in Manisa region. Flame and Graphite Furnace Atomic absorption spectrometry was used to estimate and evaluate the levels of these metals. Detected levels ranged from 0.56 to 329.7, 0.01 to 5.67, 0.26 to 30.68, 0.001 to 0.97 and 0 to 0.06 μg/g for Fe, Cu, Zn, Pb and Cd, respectively. While the highest mean levels of Cu and Zn were detected in grapevine leaves, the lowest mean levels of Fe and Pb were detected in nettle. Cd was not detected in most of the fruits and vegetables studied. The estimated daily intakes of Cu, Zn, Fe, Pb and Cd through fruits and vegetables were found to be below the maximum tolerable levels recommended by FAO/WHO. The element concentrations of fruits and vegetables analyzed in this study were within safety baseline levels for human consumption.     

Synthesis and properties of alkoxysilane-functionalized styrenated oil based polyester

Alkoxysilane-functionalized styrenated oil based polyester hybrid films were prepared by using vinyl trimethoxysilane (VTMS) as an inorganic source. For this purpose, an oil based polyester (PGMA) was first synthesized by the esterification of partial glyceride (PG) mixture with maleic anhydride (MA). Then, PGMA was further reacted with both styrene (St) and the mixture of St and VTMS yielding St–PGMA and St–PGMA–VTMS samples, respectively. The synthesis was carried out by changing VTMS content in the range of 5–15 wt.% in order to investigate the effect of inorganic domains on the film properties. While the films of St–PGMA–VTMS were formed on the appropriate substrates by moisture curing and oxidative polymerization, St–PGMA films were only cured by oxidative polymerization. The characterization of the polymers was done by FTIR, ¹H NMR, DSC, TGA and SEM. FTIR and DSC analyses indicated the completion of the moisture curing process. Film properties such as flexibility, adhesion, water, alkali and acid resistances were determined. All samples showed good film properties. Moreover, in comparison, St–PGMA–VTMS samples exhibited better alkali resistance than St–PGMA due to the contribution of the inorganic domains.     

Dual-responsive hydrogels based on maleilated curdlan-graft-poly(N-isopropylacrylamide)

The esterification reaction between curdlan and maleic anhydride was performed to provide polymerizable double bonds and pH-sensitive carboxylic groups for the curdlan chains. The new derivative was used as macromolecular cross-linker in the polymerization of N-isopropylacrylamide, when thermo and pH-sensitive networks were obtained in the form of microparticles. The loading and releasing profiles of a model macromolecular drug, lysozyme, were evaluated. The protein release rate was influenced by the pH and temperature. The pulsatile release of the lysozyme was also observed, the pulse being the swelling of the microparticles due to the decrease of the temperature under the volume phase transition temperature.