Stimulation of Phenol Removal Efficiency of Aspergillus versicolor by Surfactants,a Promising Way to Treat Phenol-Containing Waste Waters

The effect of the cationic surfactant, dodecyl trimethyl ammonium bromide (DTAB), on phenol bioremoval efficiency of an Aspergillus versicolor strain was examined. The strain was grown in mineral salt (MS) medium and the effect of DTAB was investigated as a function of different pH values, phenol and surfactant concentrations. The effect of pH was tested within the range of 4–7 and the maximum bioremoval was found at pH 4. Initial phenol concentrations investigated ranged from 100 to 600 mg/L, and the effects of surfactant concentrations on the removal were tested with 0, 0.25, 0.5 and 1 mM DTAB, which showed that 0.5 mM surfactant was the most effective concentration. The maximum bioremoval rates found after 72 h incubation were 99.48 and 99.15 % in 100 and 200 mg/L initial phenol-containing samples, respectively, where the phenol removal capacity of the fungus was only 142.373 mg/g in the DTAB blank samples. The maximum phenol uptake capacity of 267.162 mg/g was measured in the presence of 0.5 mM DTAB at 200 mg/L initial phenol concentration. These results showed that DTAB considerably increased the bioremoval efficiency of the strain tested at relatively lower phenol concentrations. The feasibility of this bioremoval method for industrial wastewater treatment is discussed.     

Microbial oil production from thermophile cyanobacteria for biodiesel production

Compared to lipid extraction from algae, little work has been performed for cyanobacteria. In this article it is aimed to show high lipid accumulation potential of Synechococcus sp., Cyanobacterium aponinum and Phormidium sp. cells in BG-11 medium. Four different pH values (6–9) and NaNO₃ (0.25, 0.5, 1.0, 1.5 g/L) concentrations were examined at different incubation days to discover the highest lipid accumulation. The maximum lipid content could be achieved in the medium containing 0.25 g/L NaNO₃ at pH 7 for Synechococcus sp., pH 8 for C. aponinum and pH 9 for Phormidium sp. after 15 days. The maximum lipid contents and C16 and C18 methyl ester yields were measured as 42.8% and 46.9% for Synechococcus sp., 45.0% and 67.7% for C. aponinum, 38.2% and 90.6% for Phormidium sp. The saturated compounds were 74.5%, 77.9%, 84.7% for Synechococcus sp., C. aponinum and Phormidium sp., respectively. These crude lipids could be promising feedstock for biodiesel production.     

Plasma‐induced,solid‐state polymerization of N‐isopropylacrylamide

The radio‐frequency plasma‐initiated polymerization of N‐isopropylacrylamide (NIPAM) in the solid state was performed. The isolated linear polymer was characterized by ¹³C‐NMR, ¹H‐NMR, and Fourier transform infrared spectroscopy, and the effects of selected operational plasma parameters (discharge power and time) on the conversion rates were studied. Reversible transitions at the volume‐phase‐transition temperatures of the swelled poly(N‐isopropylacrylamide) hydrogels were investigated by differential scanning calorimetry. The surface morphologies before and after plasma treatment were followed by scanning electron microscopy. With the obtained X‐ray diffraction results, we propose a solid‐state plasma polymerization mechanism for the NIPAM. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Design method for optimal data transmission filters

A data transmission filter design method is introduced. The method yields filters that are optimal in the sense that for given pole locations the intersymbol interference error is minimum. The prescribed loss requirements in the stopband are met and the eye diagrams are wide open.<>     

Measurements of the Efficiency of A Si(Li) Detector in the 5.5-60 keV Energy Region

Abstract

The photopeak, intrinsic, and radial efficiency of a Si(Li) detector has been determined as a function of energy over the range 5.5 to 60 keV energy region using four standard sources. Furthermore, emission probabilities for the standard sources have been determined and compared with literature values.     

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.     

Flat Dry Elastomer Adhesives as Attachment Materials for Climbing Robots

In this paper, flat elastomers are proposed as an attachment material for climbing robots on less than a few micrometer-scale rough surfaces due to their energy-efficient, quiet, and residue-free characteristics. The proper elastomer is chosen by the use of the current adhesion, friction, and peeling elastomer-contact-mechanics models. Then, adhesion and friction properties of the chosen dry flat-elastomer thick films (Vytaflex-10) are characterized on acrylic and smooth and rough glass surfaces for variations in preloads, speeds, contact times, and elastomer thicknesses. A climbing robot with four-bar-based legged-body kinematics is designed and fabricated as simple and lightweight as possible to demonstrate the feasibility of the elastomers as attachment materials on relatively smooth surfaces. The robot utilizes a passive alignment system to make the footpads parallel to the surface on light contact, a peeling mechanism to minimize the detachment vibration, and a passive tail to minimize the pitch-back moment. Experimental results showed that the robot can climb stably on vertical, smooth surfaces in any direction and can walk inverted for a limited amount of time.      

Modified Ordinal Sums of Triangular Norms and Triangular Conorms on Bounded Lattices

Having in mind that ordinal sum construction of triangular norms (triangular conorms) may not work on bounded lattices, in general, we propose a modification of ordinal sums of t‐norms (t‐conorms) resulting to a t‐norm (t‐conorm) on an arbitrary bounded lattice. In particular, our method can be applied to define connectives for fuzzy sets type 2, interval‐valued fuzzy sets, intuitionistic fuzzy sets, etc. Some illustrative examples are added, considering the interval lattice L([0, 1]), the intuitionistic lattice LI, and the diamond lattice.