Controlled assembly of carbon nanotubes encapsulated with amphiphilic block copolymer

An amphiphilic diblock copolymer (PEtOz-PCL) based on hydrophilic poly(2-ethyl-2-oxazoline) (PEtOz) and hydrophobic poly(ε-caprolactone) (PCL) was adsorbed in aqueous phase on the surface of single-wall carbon nanotube to produce PEtOz-PCL-encapsulated SWCNTs (PEtOz-PCL/SWCNT) with the diameter about 30 nm. The Raman spectroscopy analysis indicated that the nanotubes were physically encapsulated by the block copolymer without chemical denaturation of the nanotube. PEtOz-PCL/SWCNTs exhibited pH-responsive reversible complexation with poly(acrylic acid) or poly(methacrylic acid) in aqueous phase due to the pH-dependent hydrogen bonding between the PEtOz outer shell of PEtOz-PCL/SWCNTs with carboxyl groups. In addition, by using PEtOz as a template for the formation of metal nanoparticles, Au and Pd nanoparticles were successfully hybridized with PEtOz-PCL/SWCNTs.     

The effects of starvation on physical characteristics of flocs in SBR for treating saline wastewater.

This study focused on the effects of starvation on physical characteristics of flocs in SBR for treating saline wastewater. Feeding was stopped for 5 and 15 days. A time response of the floc to these starvation periods was monitored as well as the removal efficiencies of pollutants. Correlation between the physical characteristics of flocs and settling of sludge was conducted. As the starvation periods were increased, there was a shift in the floc size distribution from a high proportion of large flocs to the development of small size flocs. The fractal dimension of flocs also decreased, as starvation periods were increased. From the results, the effect of starvation on SBR treating saline wastewater can be ordered as follows: COD Mn removal < floc size and fractal dimension < T-N removal < T-P removal.     

POLARITIES OF SHRP ASPHALTS CALCULATED FROM ION EXCHANGE CHROMATOGRAPHY SEPARATION DATA

During the Strategic Highway Research Program, four asphalts were separated into polar and non-polar fractions by means of three different ion exchange chromatography procedures. For each asphalt, the non-polar neutral fractions comprised over 50 mass percent of the total asphalt. These neutral materials are much less viscous than corresponding whole asphalts. Molecular weights of the neutral fractions correlate roughly with viscosities, whereas there is no correlation between these properties for whole asphalts.

The various polar fractions were subdivided into acidic, basic, and amphoteric fractions of differing polarities. Based on dipole moments of typical components, polarity factors were assigned to each of these fractions. Multiplication of mass percentages of each fraction by their polarity factors yields polarity indices. Total polarities of asphalts or mixtures of ion exchange fractions are obtained by summing polarity indices of the unique distribution of components. Polarities of asphalts and mixtures of ion exchange fractions and viscosities of neutral fractions can be used to predict viscosities of whole asphalts and mixtures.

The method allows for prediction of effects on Theological properties of asphalts by materials whose polarities can be estimated. The success of the method supports one model of asphalt structure.     

Functional Properties of Hydrolyzed Whey Permeate Syrups in Bread Formulations

Hydrolyzed whey permeate syrups (HWPS) prepared by various treatments were incorporated at 6% flour basis as a substitute for sucrose in a typical white pan bread formulation. Results indicated that there were little significant differences in the yeast fermentation rate, proof time, and bread quality among doughs formulated with sucrose (control) and HWPS. Demineralized 75% HWPS produced good functional qualities of dough and yielded bread equal to or better than the control. The 50% and 95% HWPS had some adverse effects on the handling characteristics of the doughs. Breads made with demineralized 50% and 95% HWPS were firmer than the control. The 50% HWPS breads showed darker crust colors, whether HWPS was or was not demineralized.     

Statistical Patterns of Lipase Activities on the Release of Short-Chain Fatty Acids in Cheddar Cheese Slurries

Twenty-five commercial food grade and analytical grade lipases were used to study the patterns of release of short-chain fatty acids (FFA) from milk fat in cheese slurries. Principal Component Analysis showed that there were four distinctive groups indicated by the FFA ratios and five groups indicated by the FFA concentrations. Average Linkage Cluster Analysis also showed similar results although the patterns of FFA released were a matter of distances defined statistically between groups of lipases. All the lipases tested had distinctive specificities in hydrolyzing short-chain FFA from milk fat, and their specificities on the FFA release were reflected on the groupings.     

POLARITIES OF SHRP ASPHALTS CALCULATED FROM ION EXCHANGE CHROMATOGRAPHY SEPARATION DATA

Abstract

During the Strategic Highway Research Program, four asphalts were separated into polar and non-polar fractions by means of three different ion exchange chromatography procedures. For each asphalt, the non-polar neutral fractions comprised over 50 mass percent of the total asphalt. These neutral materials are much less viscous than corresponding whole asphalts. Molecular weights of the neutral fractions correlate roughly with viscosities, whereas there is no correlation between these properties for whole asphalts.

The various polar fractions were subdivided into acidic, basic, and amphoteric fractions of differing polarities. Based on dipole moments of typical components, polarity factors were assigned to each of these fractions. Multiplication of mass percentages of each fraction by their polarity factors yields polarity indices. Total polarities of asphalts or mixtures of ion exchange fractions are obtained by summing polarity indices of the unique distribution of components. Polarities of asphalts and mixtures of ion exchange fractions and viscosities of neutral fractions can be used to predict viscosities of whole asphalts and mixtures.

The method allows for prediction of effects on Theological properties of asphalts by materials whose polarities can be estimated. The success of the method supports one model of asphalt structure.     

Effects of ${hbox{CNT/BaTiO}}_{3}$ Composite Particles Prepared by Mechanical Process on Dielectric Properties of Epoxy Hybrid Films

A new type of composite filler mechanically treated with multi-walled carbon nanotubes (MWNTs) and (BT) particles was prepared to produce higher dielectric properties in the composite. The hybrid film fabricated by incorporating these composite fillers in an epoxy matrix had a high dielectric constant and similar dielectric loss as compared to the composite which contained neat BT particles. The dielectric properties of these hybrid films were found to be dependent on both the content of MWNTs and mechanical processing time. Results suggest that this novel hybrid film composed of the composite filler and the epoxy matrix can be used for embedded capacitor material.     

Comparison of High Performance Liquid Chromatography and Enzymatic Method for the Measurement of Lactose in Milk

A high performance liquid chromatographic (HPLC) procedure was compared with an enzymatic method for the measurement of lactose in milk. A new rapid HPLC sample preparation technique was used for precipitating milk proteins with 2-propanol. Results indicated that lactose detected in milk (expressed as percentage) was consistently lower with the enzymatic method than the HPLC procedure. Mean difference between the two methods was 0.15% with a range of 0.04 to 0.51. Coefficient of variability for the HPLC and enzymatic methods were 1.02 and 2.75, respectively. Recovery of added lactose in milk by HPLC was 100.3% for whole milk, 97.1% for low fat milk, and 99.5% for skim milk.     

Charge transfer in graphene/polymer interfaces for CO<Subscript>2</Subscript> detection

Understanding charge transfer processes between graphene and functional materials is crucial from the perspectives of fundamental sciences and potential applications, including electronic devices, photonic devices, and sensors. In this study, we present the charge transfer behavior of graphene and amine-rich polyethyleneimine (PEI) upon CO₂ exposure, which was significantly improved after introduction of hygroscopic polyethylene glycol (PEG) in humid air. By blending PEI and PEG, the number of protonated amine groups in PEI was remarkably increased in the presence of water molecules, leading to a strong electron doping effect on graphene. The presence of CO₂ gas resulted in a large change in the resistance of PEI/PEG-co-functionalized graphene because of the dramatic reduction of said doping effect, reaching a maximum sensitivity of 32% at 5,000 ppm CO₂ and an applied bias of 0.1 V in air with 60% relative humidity at room temperature. This charge transfer correlation will facilitate the development of portable graphene-based sensors for real-time gas detection and the extension of the applications of graphene-based electronic and photonic devices.

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Secure D-CAS system for digital contents downloading services

The digital contents market is growing rapidly and we can retrieve digital contents through various multimedia devices including portable hand-held devices, smart phones, and home devices. On the other side, many digital contents without the consent of copyright holders are shared on the Internet. Those copyright infringement problems undermine authoring needs of the digital contents manufacturers and also wither the development of digital contents market. We are sure that we need secure distribution mechanisms for the digital contents supply chain in order to revitalize contents services and markets more and more. Many research projects to limit contents utilization onto legitimate users and to provide secure contents protection and download are in progress. In this paper, we propose a secure D-CAS system (SDCAS) which provides security enhancement to various digital contents downloading services.