Electrokinetic remediation of heavy metal-contaminated soils: performance comparison between one- and two-dimensional electrode configurations

Journal of Soils and Sediments - Electrokinetic (EK) soil remediation is significantly affected by the electrode configurations. Therefore, this study was conducted to compare the performance of...     

Fluorescence and NIR spectroscopic study on the water interaction in polycarbonate film

Water interactions in polycarbonate films have been studied using fluorescence and NIR Fourier transform spectroscopy. During water sorption process, the fluorescence emission spectra showed sensitive changes with the peak at 332 nm red shifted by 18 nm with water sorption. This red-shifted peak could be due to phenyl-2-phenoxybezoate, which is one of two major thermal degradation products in polycarbonate. In the spectra of phenyl-2-phenoxybenzoate in dimethyl formamide solution, a progressive red shift was also observed with the water addition. By using the NIR spectra, hydrogen-bonding interactions of the sorbed water with polycarbonate were investigated. It was found that water can be analyzed as free water S₀ or single hydrogen bonded water, S₁ while double hydrogen bonded water was negligible. During water immersion, most water species which are present as S₀ species decrease slightly, with a small increase in S₁ species. During desorption, S₀ species decrease sharply, while S1 species is reduced gradually. Two examples of S₁ structure in water-sorbed polycarbonate are proposed.     

Effect of glycerol cross-linking and PDI on the shape memory effect and mechanical properties of polyurethane

A series of shape memory polyurethane (PU) copolymers synthesized from 1,4-phenyldiisocyanate (PDI), poly(tetramethyleneglycol) (PTMG), 1,4-butanediol (BD) as a chain extender, and glycerol as a cross-linking agent were tested for the mechanical properties and the shape memory effect at the temperature 20 °C above melting temperature (T _m), and were compared with other PUs synthesized from 4,4′-methylene-bis-phenyldiisocyanate (MDI), PTMG, and BD. Mechanical properties and shape memory effect were improved substantially by adopting both PDI and glycerol. Interestingly, enthalpy of melting and T _m were not affected by the glycerol content. Vibration and shock absorption ability was investigated by measuring both loss tan δ and storage modulus with dynamic mechanical analyzer (DMA).     

Evaluation of water holding capacity and breadmaking properties for frozen dough containing ice structuring proteins from winter wheat

The effects of ice structuring proteins (ISPs) from white wheat and storage conditions on the water holding capacity (WHC) and breadmaking properties of frozen dough were investigated. The WHC of frozen dough was measured by centrifugation and the breadmaking properties were assessed as proofing time and bread specific volume. It was found that the prolonged frozen storage and freeze–thaw cycles decreased the WHC and breadmaking properties of dough. ISPs were highly effective in increasing the WHC of frozen dough and improving the breadmaking properties. There was a strong correlation between WHC and breadmaking properties (proofing time and bread specific volume) of frozen dough.     

Copper metallization of poly(ethylene terephthalate) fabrics via intermediate polyaniline layers

Poly(ethylene terephthalate) fabrics were metallized through electroless plating of copper. The copper plating was performed on palladium-decorated polyaniline surfaces, and polyaniline was present as an intermediate layer on fabrics to facilitate palladium formation. Different oxidation states of polyaniline were tested in their efficacy in Pd (II) reduction and subsequent Cu plating. X-ray photoelectron spectroscopy was used to monitor the surface changes along the metallization procedure, and surface resistance was measure to probe the electrical properties of the metallized fabrics.     

Synthesis and application of o,o′-dihydroxyazo dyes and their metal complexes

This paper presents the synthesis of metal complex acid dyes obtained from the reaction of o,o′-dihydroxyazo dyes and chromium and cobalt sulfate. The ¹H-NMR, FT-IR and UV/Visible Spectrophotometer, TLC (Thin Layer Chromatography) and ICP (Ion Chromatography) of the intermediates and the metal complexes were studied and compared. Their properties such as dyeing, fastness and toxicity on nylon were also assessed according to standard methods.     

Application of the real fabric frictional speeds to the fabric sound analysis using water repellent fabrics

This study aims to determine fabric frictional speeds between the arm and the trunk when people walk (1.3 m/s), jog (2.5 m/s) and run (4.5 m/s), and to apply the measured speeds to setting a sound generator for each motion to obtain fabric rustling sounds. By analyzing body motions captured by the Falcon motion analysis system and a camcorder, it was identified that the friction between the arm and trunk occurred within 10° of shoulder angle along the center line of the trunk in the sagittal plane and the maximum frictional speed occurred at the elbow within the shoulder friction range. The averages (SDs) of maximum frictional speed at the elbow were found 0.63 m/s (0.17) at walking, 1.1 m/s (0.25) at jogging, and 1.98 m/s (0.35) at running. The frictional sounds of three coated nylon fabrics were obtained using these predetermined speeds. We calculated sound characteristics such as the sound pressure levels (SPL) and Zwicker’s psychoacoustic parameter using 1/3 octave band analysis. The SPL values ranged from 74.2 dB at running to 79.0 dB at jogging, which was about the same noise level as in the busy street. The values of loudness (Z) at walking and jogging were higher than that at running, but the fluctuation strength (Z) increased in the order of walking, jogging, and running.     

Miscibility of flame retardant epoxy resin with poly(ethylene terephthalate) and the characterizations of the blends

Epoxy resin containing bromine compound was melt blended with PET to obtain flame retardant polymer. The blend product was characterized by DSC, SEM, intrinsic viscosity and melt index measurements. The reaction between the epoxy group of DGEBBA (diglycidyl ether of brominated bisphenol A) and the carboxyl (or hydroxyl) end group of PET led to cross-linking of PET chains, and the intrinsic viscosity and melt index (MI) were increased in the range of equivalent amount of epoxy resin (within 1 %). DSC data revealed that the epoxy resin was not located in the crystalline region but was appeared in the amorphous region of PET matrix. Good miscibility of epoxy resin resulted in the decrease of crystallization temperature and glass transition temperature of PET. The blend was spun into fiber without any problems such as swelling or draw resonance, however, the mechanical properties were decreased as the amount of the DGEBBA was increased.     

Synthesis and optical/chemical properties of triphenylamine derivatives based mono-, di-, and tri-indanedione

In this contribution, three triphenylamine derivatives were synthesized and their spectral properties were investigated. Knoevenagel condensation of mono-, di-, and tri-aldehydes of triphenylamine with 1,3-indanedione yields D-π-A type dyes with push-pull chromophores. The absorption and luminescence properties of the dyes were discussed in terms of their electronic structures. The results of molecular orbital computer simulations, based on Material Studio, were found to provide a reasonable explanation for the observed spectral properties related to the push-pull features causing dramatic changes in UV-Vis absorption as well as in photoluminescence.     

Inheritance and field performance of transgenic Korean Bt rice lines resistant to rice yellow stem borer

Transgenic Korean rice plants containing the cry1Ab gene were developed for resistance against yellow stem borer (Scirpophaga incertulas, YSB). More than 100 independent transgenic lines from three Korean varieties (P-I, P-II and P-III) were generated. The amount of Cry1Ab in transgenic T₀ plants was as high as 2.88% of total soluble proteins. These levels were sufficient to cause 100% mortality of YSB larvae. The majority of T₁ transgenic lines originated from the varieties P-I and P-II followed a Mendelian fashion of segregation. Deviation from the expected segregation ratio was observed in a small number of the transgenic lines of P-I and P-II origins. However, this deviation was primarily observed in the P-III originated lines. Segregation analysis of the T₁ generation indicated that 1–3 copies of the cry1Ab gene were integrated into the genome of the majority of the transgenic lines originating from varieties P-I and P-II. Stunted and semi-fertile mutants were observed in some transgenic lines. These aberrations were either independent or closely linked to the introduced cry1Ab gene loci in different transgenic lines. Reduction in GUS expression levels and loss of toxicity against YSB larvae were found in some transgenic lines. The transgenic T₃ and T₄ lines causing 100% mortality of third instar YSB larvae in the lab were completely protected in the field. Analysis of important yield components on nine selected transgenic lines indicated that stem length, panicle length, grain number per panicle, and seed setting rates were reduced in transgenic plants compared to those in non-transgenic parental rice lines. Number of panicles per cluster, however, was significantly higher in transgenic plants. The numerical value of the average yield was in general greater in the controls than in all the transgenic lines, indicating some ‘yield drag’. Since some selected lines were highly resistant to the YSB with good yielding potential, they offer effective potential for use in insect resistance management programs.