Antioxidant and anticholinesterase evaluation of selected Turkish Salvia species

Since Salvia species (Lamiaceae) have been recorded to be used against memory loss in European folk medicine, we herein examined in vitro anticholinesterase and antioxidant activities of 56 extracts prepared with petroleum ether, chloroform, ethyl acetate and methanol obtained from 14 Salvia species (Salvia albimaculata Hedge and Hub, Salvia aucheri Bentham var. canescens Boiss and Heldr, Salvia candidissima Vahl. ssp. occidentalis, Salvia ceratophylla L., Salvia cryptantha Montbret and Bentham, Salvia cyanescens Boiss and Bal., Salvia frigida Boiss, Salvia forskahlei L., Salvia halophilaHedge, Salvia migrostegia Boiss and Bal., Salvia multicaulis Vahl., Salvia sclarea L., Salvia syriaca L., Salvia verticillata L. ssp. amasiaca) growing in Turkey. The antioxidant activities were assessed by both chemical and enzymatic methods against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging and xanthine/xanthine oxidase (XO) system generated superoxide anion radical inhibition. Anticholinesterase effect of the extracts was tested against both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) at concentrations of 0.2 and 1 mg/ml using a microplate-reader assay based on the Ellman method. Most of the extracts did not show any activity against AChE at 0.2 mg/ml, while the chloroform extracts had noticeable inhibition against BChE between 47.7% and 74.7%. The most active extracts at 1 mg/ml for AChE inhibition were observed to be petroleum ether extract of Salvia albimaculata (89.4%) and chloroform extract of Salvia cyanescens (80.2%), whereas ethyl acetate extracts of Salvia frigida and Salvia migrostegia, chloroform extracts of Salvia candidissima ssp. occidentalis and Salvia ceratophylla, as well as petroleum ether extract of Salvia cyanescens were found to inhibit potently BChE (92.2%, 89.6%, 91.1%, 91.3%, and 91.8%, respectively). Particularly, the ethyl acetate and methanol extracts were observed to be highly active against both DPPH and XO. Our data indicates that nonpolar extracts of Salvia species for anticholinesterase activity and the polar extracts for antioxidant activity are worth further phytochemical evaluation for identifying their active components.     

Infrared absorption in thick film resistors

Infrared absorption in polymer and glass-based thick film resistors has been measured between 400 and 1500 cm^–1. Sample structures are discussed on the basis of X-ray, Fourier transform-infrared and resistance-temperature data. It is shown that in polymer-based thick film resistors, the particulate phase is mostly responsible for the infrared absorption between 400 and 900 cm^–1, whereas the infrared absorption at higher wave numbers is related to the continuous phase. In glass-based thick film resistors, absorption is mostly determined by the highly doped glass. The results indicate that thick film resistors can be used as an absorbent coating in the 400–1500 cm^–1 region by suitable selection of the continuous and particulate phases.     

Evaluation of deflection amplification factor in steel moment‐resisting frames

Steel moment‐resisting frames (SMRFs) are the most common type of structural systems used in steel structures. The first step of structural design for SMRFs starts with the selection of the structural sections on the basis of story drift limitation. ASCE 7 (2010) requires that the inelastic story drifts be obtained by multiplying the deflections determined by elastic analysis under design earthquake forces with a deflection amplification factor (C_d). For special moment‐resisting frames, C_d is given as 5.5 in ASCE 7 (2010). Lower C_d values will increase the overall inelastic response of the structure. On the other hand, the inelastic response of the structure is expected to be less severe when designed for higher C_d values. The performance objective is that the structure should sustain the inelastic deformation demand imposed due to design earthquake ground motions. This study aims at investigating the inelastic seismic response that low‐rise, medium‐rise and high‐rise SMRFs can experience under design earthquake ground motions and maximum considered earthquake (MCE) level ground motions and evaluating the deflection amplification factors (C_d) for SMRFs in a rational way. For this purpose, nonlinear dynamic time history and pushover analyses will be carried out on SMRFs with 4, 9 and 20 stories. The results indicate that the current practice for computing the inelastic story drifts for SMRFs is rational and the frames designed complying with the current code requirements can sustain the inelastic deformations imposed during design earthquake ground motions when seismically designed and detailed. Copyright © 2013 John Wiley & Sons, Ltd.     

A new approach to constructing Green’s functions and integral solutions in thermoelasticity

This paper is devoted to a new approach for the derivation of main thermoelastic Green’s functions (MTGFs), based on their new integral representations via Green’s functions for Poisson’s equation. These integral representations have permitted us to derive in elementary functions new MTGFs and new Poisson-type integral formulas for a thermoelastic octant under mixed mechanical and thermal boundary conditions, which are formulated in a special theorem. Examples of validation of the obtained MTGFs are presented. The effectiveness of the obtained MTGFs and of the Poisson-type integral formula is shown on a solution in elementary functions of a particular BVP of thermoelasticity for octant. The graphical and numerical computer evaluation of the obtained MTGFs and of the thermoelastic displacements of the particular BVP for an octant is also presented. By using the proposed approach, it is possible to derive in elementary functions many new MTGFs and new Poisson-type integral formulas for many canonical Cartesian domains.     

Transport priorities,risk perception and worry associated with mode use and preferences among Norwegian commuters

There is currently scant research on the role of transport priorities, risk perception and worry for travel mode use and preferences. The present study aims to examine these factors in relation to mode use and preferences among Norwegian commuters. A web-based survey was conducted in a randomly obtained representative sample of daily commuters in the extended greater Oslo area (n = 690). The results showed that those who prioritized efficiency and flexibility tended to commute by car, while those who prioritized safety and comfort used public (e.g. metro, tram, and train) or active (e.g. walking and cycling) transport. In a free choice scenario, the respondents who prioritized flexibility reported a preference for using a car, whereas those who prioritized safety and comfort preferred public and active transport for their commuter travels. Risk perception of high impact events, such as terrorism and major accidents, as well as risk perception related to personal impact risks (theft, violence etc.) were related to car use on commuter travels. Transport-related worry exerted weak influences on mode use and preferences. Increased speed on rail transport and more frequent departures may be effective in reducing car use on commuter travels. Risk communication should focus on highlighting the low risk of experiencing security and safety issues in the public transport sector, and this message should be complemented by efforts to reduce the probability of negative events affecting public transport.     

Variable Cross-Section Cylinder-Type Corona and Combined Corona–Dielectric Barrier Discharge Precipitators for Fly-Ash Particles

This article is aimed at evaluating three designs of cylindrical-type electrostatic precipitators that might be installed at the output of household boilers in order to reduce the pollution due to burning wood or fossil fuels. The first design is the “standard” precipitator, which consists in a thin copper wire (0.16 mm in diameter), coaxial with a cylindrical aluminum cylinder, 345 mm in length, of constant radius (20 mm). The second and third designs, equipped with a similar wire electrode, are characterized by the same global length, but are divided into three sections, two having the same cross-section as the “standard” precipitator, while the third section, 20 mm in length and located between them, has a smaller radius (11.5 mm). The reduction of the diameter in this central section of the precipitator is done by introducing an aluminum ring, covered by a sleeve made of either aluminum (design #2) or polyvinyl chloride (design #3). Together with the modification of the conditions for mechanical collection of particles, the more intense corona (design #2) or dielectric barrier discharges (design #3) generated in these sections of reduced diameter contribute to a significant increase of precipitation efficiency.     

Two-Dimensional Green's Function for Thermal Stresses in a Semi-Layer Under a Point Heat Source

We present specific new expressions for thermal stresses as Green's functions for a plane boundary value problem of steady-state thermoelasticity for a semi-layer. We also obtain new integration formulas of Green's type, which determine the thermal stresses in the form of integrals of the products of the given distributed internal heat source, boundary temperature, and heat flux and derived kernels. Elementary functions results obtained are formulated in a theorem, which is proved using the harmonic integral representations method to derive thermal stresses Green's functions, which are written in terms of Green's functions for Poisson's equation. A new solution to particular two-dimensional boundary value problem for a semi-layer under a boundary constant temperature gradient is obtained in explicit form. Graphical presentations for thermal stresses Green's functions created by a unit heat source (line load in out-of-plane direction) and by a temperature gradient are also included.     

The effect of various factors on the hydrogen generation by hydrolysis reaction of potassium borohydride

Potassium borohydride (KBH₄) reacted very slowly with water to liberate 4 mol of hydrogen/mol of compound at room temperature. The hydrolysis and stability conditions of KBH₄ investigated depend on KBH₄ concentrations, concentration of alkaline solutions, temperatures and electrical field intensity. Yield of produced hydrogen by self-hydrolysis of KBH₄ increases as the temperature increased and it produced 53.9% yield at the end of 300 min at 60 °C. The reaction rate order of hydrolysis of KBH₄ in aqueous solution is found at about 0.7–0.8 and the activation energy for hydrolysis is calculated as 14,700 kJ/mol. Potassium borohydride is stable both in room temperature and in aqueous alkaline solution. In this study, the electrical field that is not needed for catalytic activity was used for the hydrolysis of KBH₄ aqueous solution. It was found that 6 mol of hydrogen/mol of potassium borohydride was liberated in the presence of electrical field, whereas 4 mol of hydrogen was produced in the absence of electrical field per mol of potassium borohydride.     

Adsorption characteristics of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto chitosan/clinoptilolite sorbents

Adsorption features of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto a novel chitosan/clinoptilolite (CS/CPL) composite as beads have been investigated compared with chitosan cross-linked with epichlorohydrin. The effects of contact time, the initial metal ion concentration, sorbent mass and temperature on the adsorption capacity of the CS-based sorbents were investigated. The adsorption kinetics was well described by the pseudo-second order equation, and the adsorption isotherms were better fitted by the Sips model. The maximum experimental adsorption capacities were 328.32 mg Th(4+)/g composite, and 408.62 mg UO(2)(2+)/g composite. The overall adsorption tendency of CS/CPL composite toward UO(2)(2+) and Th(4+) radiocations in the presence of Cu(2+), Fe(2+) and Al(3+), under competitive conditions, followed the order: Cu(2+)>UO(2)(2+)>Fe(2+)>Al(3+), and Cu(2+)>Th(4+)>Fe(2+)>Al(3+), respectively. The negative values of Gibbs free energy of adsorption indicated the spontaneity of the adsorption of radioactive ions on both the CS/CPL composite and the cross-linked CS. The desorption level of UO(2)(2+) from the composite CS/CPL, by using 0.1M Na(2)CO(3), was around 92%, and that of Th(4+) ions, performed by 0.1M HCl, was around 85%, both values being higher than the desorption level of radiocations from the cross-linked CS, which were 89% and 83%, respectively.