Supercritical fluid extraction of daphne (Laurus nobilis L.) seed oil

Laurus nobilis L., commonly known as daphne tree, is an evergreen that belongs to the Lauraceae family. Daphne trees produce grape-sized shiny purplish berries having three parts: flesh, skin, and an inner kernel (single seed). This study examines supercritical CO₂ (SC-CO₂) extraction of oil from daphne seeds. The oil yield of ground seeds varied from 14 to 28% depending on the method and particle size used for oil recovery. Yields were similar for both petroleum ether and SC-CO₂ extraction. The extraction yield decreased significantly with increasing particle size. The amount of extract collected increased exponentially with increasing SC-CO₂ pressure. The highest extraction yield was obtained at the highest temperature studied, 75°C. More than 45% of the oil was lauric acid. SC-CO₂ is a viable technique to obtain high-purity L. nobilis L. seed oil, which is a potential ingredient for the cosmetic industry.     

A comprehensive survey: artificial bee colony (ABC) algorithm and applications

Swarm intelligence (SI) is briefly defined as the collective behaviour of decentralized and self-organized swarms. The well known examples for these swarms are bird flocks, fish schools and the colony of social insects such as termites, ants and bees. In 1990s, especially two approaches based on ant colony and on fish schooling/bird flocking introduced have highly attracted the interest of researchers. Although the self-organization features are required by SI are strongly and clearly seen in honey bee colonies, unfortunately the researchers have recently started to be interested in the behaviour of these swarm systems to describe new intelligent approaches, especially from the beginning of 2000s. During a decade, several algorithms have been developed depending on different intelligent behaviours of honey bee swarms. Among those, artificial bee colony (ABC) is the one which has been most widely studied on and applied to solve the real world problems, so far. Day by day the number of researchers being interested in ABC algorithm increases rapidly. This work presents a comprehensive survey of the advances with ABC and its applications. It is hoped that this survey would be very beneficial for the researchers studying on SI, particularly ABC algorithm.     

A modified genetic algorithm for forecasting fuzzy time series

Fuzzy time series approaches are used when observations of time series contain uncertainty. Moreover, these approaches do not require the assumptions needed for traditional time series approaches. Generally, fuzzy time series methods consist of three stages, namely, fuzzification, determination of fuzzy relations, and defuzzification. Artificial intelligence algorithms are frequently used in these stages with genetic algorithms being the most popular of these algorithms owing to their rich operators and good performance. However, the mutation operator of a GA may cause some negative results in the solution set. Thus, we propose a modified genetic algorithm to find optimal interval lengths and control the effects of the mutation operator. The results of applying our new approach to real datasets show superior forecasting performance when compared with those obtained by other techniques.     

A Study on Glutaric Acid Extraction by Tridodecylamine: Equilibria and Models

The extraction of glutaric acid was studied using tridodecyl amine (TDA) with respect to the functional groups of the diluent. The diluents studied were 1‐octanol (alcohol), methyl isobuthyl ketone, MIBK (ketone), and toluene (aromatic hydrocarbon) and these were used to dilute the TDA. The experimental results of batch extraction experiments are reported as distribution coefficients, D_C, loading factors, Z, and extraction efficiency, E. All measurements were carried out at 298.15 K. The results of the liquid‐liquid equilibrium measurements are correlated by a linear solvation energy relationship (LSER) model that takes into account physical interactions and modified Freundlich and Langmuir equations. The experimental results are compared with model results.     

Investigation of current‐voltage characteristics and current conduction mechanisms in composites of polyvinyl alcohol and bismuth oxide

Temperature dependent current‐voltage (I–V) measurements of Au/Polyvinyl Alcohol + Bi₂O₃/n‐Si structure were conducted between 100 and 350 K for investigating the temperature dependence of I–V characteristics and current conduction mechanisms in the structure. Series resistance of the structure is calculated using Ohm's law and Cheungs' method. Ideality factor (n) and zero‐bias barrier height (Φ_Bo) were obtained considering thermionic emission theory. From 100 to 350 K, n changed from 32.1 to 3.54, and Φ_Bo changed from 0.27 to 0.99 eV. Obtained temperature dependent values of n and Φ_Bo suggested that thermionic emission is not the dominant current conduction mechanism. Therefore, Ln(I)–Ln(V) curves of the studied structure were plotted for investigating current conduction mechanisms in the structure and current flow is explained considering space charge limited current. Moreover, density of interface states (D_it) in the structure were calculated and its temperature dependence was investigated such that D_it values are reduced to the order of ～10¹³ eV^?1 cm^?2 from ～10¹⁴ eV^?1 cm^?2 with increasing temperature. POLYM. ENG. SCI., 54:1811–1816, 2014. © 2013 Society of Plastics Engineers     

A Review of Dehydration of Various Industrial Sludges

Wastewater characteristics and sludge generation potential of point source categories are reviewed critically. Novel industry-specific sludge dewatering/drying solutions necessary to establish a sustainable model are examined through a detailed literature survey. Knowledge of sludge properties is one of the most critical issues needed to design dewatering/drying equipment. This study focuses on industrial wastewater/sludge characterization. In addition, a comprehensive review of current drying models and technologies is also presented. A summary of the results derived from a novel thin-film-based photonic sludge dewatering/drying study is outlined as an alternative approach for industrial sludge control. Sludge was dried in a tubular quartz reactor (TQR), the inner surface of which was coated with a TiO₂ thin film. The TQR was irradiated with UV A, UV B, and UV C lamps. The consumed and generated energy fluxes through endergonic and exergonic reactions driven by photolysis and photocatalysis were investigated. In addition, the variations in sludge dewatering/drying characteristics were also examined and compared with conventional methods to evaluate the energy requirements.     

Incidence and antibiotic resistance of Salmonella spp. on raw chicken carcasses

The current study was carried out to detect Salmonella spp. contamination on chicken carcasses and to determine the antibiotic susceptibility profiles and serotype distribution of the isolates. A total of 200 packaged fresh raw chicken samples sold at retail in different markets in central Anatolia were analysed between April 2005 and March 2006. Salmonella spp. was detected in 34% (68/200) of samples using cultural technique and were confirmed by PCR. Ten Salmonella serovars were identified; predominant ones included Typhimurium, Infantis and Heidelberg. All of the Salmonella spp. isolates tested, exhibited resistance to one or more antimicrobial agents used. Resistance to penicillin, oxacillin, clindamycin, vancomycin, erythromycin and ampicillin were evident 100%, 97%, 97%, 92.6%, 89.7% and 85.2%, respectively. Also resistance to tetracycline (67.6%), streptomycin (61.7%), neomycin (55.8%) and cephalothin (52.9%) was observed but a small percentage of the isolates demonstrated resistance to gentamicin (14.7%), chloramphenicol (10.2%), cefotaxime (2.9%) and amikacin (2.9%). As a result, high prevalence of Salmonella spp. and the relatively high resistance among the bacteria tested could pose public health and therapeutic problems in consumers as potential vehicle of resistant Salmonella foodborne infections. To avoid Salmonella contamination, hygienic rules of slaughter and poultry meat processing must be rigorously observed and antibiotic use must be controlled by governmental agencies to prevent increased resistance of antibiotics.