Comparative Study of Sc(III) Sorption onto Carbon-based Materials

The sorption behavior of Sc(III) on different materials including activated carbon (AC), carbon nanotubes (CNTs), graphene oxide (GO), and the chelating resin Chelex 100 was investigated. In general, the sorption of scandium increases with increasing pH. For pH in the range from 2.5 to 5.5, the sorption of Sc(III) onto CNTs, GO, and Chelex 100 is quantitative, whereas a significantly lower amount of scandium ions was retained on AC. The specific amount of Sc(III) adsorbed at pH 2 attained 2.1, 2.9, 36.5, and 37.9 mg g^?1 for AC-COOH, Chelex 100, GO, and CNTs-COOH, respectively. At pH 4, a similar value was obtained for oxidized AC (2.2 mg g^?1), whereas the specific amount adsorbed significantly increased for Chelex (23.4 mg g^?1). The highest values were obtained for GO (39.7 mg g^?1) and oxidized CNTs (42.5 mg g^?1). Better kinetic retention was observed at pH 2 for CNTs and GO, whereas at pH 4 the kinetic behavior of Chelex 100, GO, and CNTs toward Sc(III) was comparable.     

Partitioning factor of mercury during coal combustion in low capacity domestic heating units

Data from an experiment concerning Hg emission from coal combustion in a furnace of 5.6 kW capacity are presented. The goal of the experiment was to define how much of the mercury in coal combusted in the stove was emitted to the atmosphere in gaseous form because vapors contribute mainly to human intake of the metal from ambient air. The partitioning factor kappa, defined as the ratio of gaseous mercury mass emitted to the air and mercury mass contained in the unit coal mass before combustion was evaluated. The mean value of the kappa factors determined in the study was 0.52 indicating that on average only 52% of the mercury was emitted to the air in gaseous form during coal combustion in an apparatus similar to a domestic furnace. The kappa value determined seems relatively low indicating that besides mercury emitted to the atmosphere in gaseous form, a large portion of the mercury is present in particulate matter trapped in the chimney duct and emitted to the air.     

Interactive versus noninteractive interventions and dose–response relationships for stage-matched smoking cessation programs in a managed care setting.

This study compared interactive and noninteractive smoking cessation interventions for a population of smokers who were all members of 1 division of a managed care company. In addition, it examined whether a dose-response relationship existed. Screening was completed for 19,236 members who were contacted by telephone or mail. Of the 4,653 who were identified as smokers, 85.3% were enrolled. A 2 Intervention (interactive or noninteractive)?×?4 Contacts (1, 2, 3, or 6 contacts)?×?4 Occasions (0, 6, 12, and 18 months) design was used. The interactive intervention was stage-matched expert-system reports plus manuals; the noninteractive intervention was stage-matched manuals. Contact occurred in 1 of 4 series (1, 2, 3 or 6 contacts) at 3-month intervals. The expert system outperformed the stage-matched manuals, but there was no clear dose-response relationship for either intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quercetin content in some food and herbal samples

Quercetin is a typical flavonoid ubiquitously present in vegetables and fruits, and its antioxidant effect is implied to be helpful for human health. The efficiency of extraction process and acidic hydrolysis parameters for HPLC analysis of quercetin present in glycosides and aglycone forms was investigated. Hydrolysis for 5 min in the presence of 2.8 M HCl as well as for 10 min with 1.1 M HCl efficiently released quercetin from rutin. The method developed in this study was applied for quantitative determination of quercetin in some food (onion, apple) and herbal (Hypericum perforatum and Sambucus nigra) products.     

Microstructure Characterization of Cold‐Rolled Dual‐Phase Steels

The evolution of the microstructure of cold‐rolled dual‐phase steels during annealing is investigated. For this purpose, a cold‐rolled dual‐phase grade is annealed in the laboratory. Annealing cycles are applied to systematically investigate various cooling rates and isothermal holding temperatures and times relevant for continuous annealing lines exhibiting an overaging zone. In addition to the characterization of the microstructure by means of light optical metallography and transmission electron microscopy, mechanical properties are presented.     

Method of achieving desired potentiometric responses of polyacrylate-based ion-selective membranes

We introduce a simple procedure allowing preparation of cation-selective electrodes with poly( n-butyl acrylate)-based membranes containing different proportions of primary and interfering ions introduced already at the membrane preparation step, by using two different liphophilic salts of the same anion. With this approach the time required to achieve saturation of polyacrylate membranes with primary ions can be significantly shortened. Moreover, depending on the ratio of the primary and interfering ions introduced to the membrane cocktail, different potentiometric responses are obtained ranging from typical (with micromolar detection limit), through lower detection limits to super-Nernstian ones.     

Cross-linked polymer brushes. II. Formation and properties of poly(isobutyl vinyl ether)-b-poly[2-(vinyloxy)ethyl cinnamate] brushes

A diblock copolymer, i.e., poly(isobutyl vinyl ether)-b-poly[2-(vinyloxy)ethyl cinnamate] (PIBVE-b-PVEC), has been shown to form polymer brushes quickly on the surface of solid substrates by deposition from a solvent selectively poor for PVEC. The resultant brush could be cross-linked photochemically by initiating the dimerization between VEC groups of different polymer chains and the cross-linking was extremely efficient. Crosslinked polymer brushes, as expected, were resistant to organic solvent, such as chloroform, and nitric acid attacks. Important industrial applications are expected of cross-linked brushes. © 1994 John Wiley & Sons, Inc.     

Dielectric properties of vanadium doped barium titanate synthesized via high-energy ball milling

The study shows the advisability of using a mechanochemical synthesis method, based on a high-energy planetary ball milling, to a modification of barium titanate by a vanadium doping. This method improves useful properties of BaTi_0:95V_0:05O₃ as a capacitor material. It has a high value of electric permittivity ?′ in the wide range of temperature and low dielectric losses ?″ as well as a low electrical conductivity.     

Polymer Nano-Materials Through Self-Assembly of Polymeric POSS Systems

The self-organization of polyhedral silsesquioxane (POSS) moieties tethered as side groups onto flexible backbones of amorphous siloxanes and poly(1,2-butadiene) was investigated. For comparison, linear oligosiloxanes substituted with POSS units at the chain end (α- or α,ω-functionalization) were examined. The properties of POSS-functionalized materials were studied (SAXS, WAXD, DSC, TGA, and optical microscopy). The formation of organized POSS assemblies was monitored as a function of the structure of the polymer chain, as well as the POSS concentration in the polymer matrix. It was confirmed that the rubbery polymers allow the pendant POSS units to assemble without the competition of the main chain crystallization. Materials with a larger number of POSS groups tend to form lamellar structures. It was found that the process of disintegration of POSS assemblies in siloxanes is thermally driven. The temperature of melting depends on the structure of a POSS assembly, and the time needed for the organized structure recovery from the melt depends on the type of arrangement of POSS-moieties that is to be formed. At a low POSS content besides the POSS assemblies, which are crystallites of nanometric size, larger polycrystalline objects of micrometric sizes are formed. They consist of a greater number of POSS crystallites embedded in the siloxane polymer. Their shapes and sizes are dependent on the polymer structure and the history of the polymer sample.     

Dye–surfactant interaction in aqueous solutions

The interaction of four ionic dyes, C.I. Mordant Black 11, C.I. Mordant Black 17, C.I. Direct Yellow 50 and C.I. Basic Blue 9, with cationic and anionic surfactants was studied by absorption spectroscopy. The dyes interact strongly with oppositely charged surfactant in the premicellar concentration range and the appropriate values of constant of dye–surfactant complex formation were estimated. In addition, the most important factor affecting the number of dye particles solubilized in the surfactant micelle was its molecular mass.