Effects of Two-stage Heat Treatment on Delayed Coke and Study of Their Surface Texture Characteristics

In the present study, surface texture features and chemical properties of two types of cokes, made from coal tar by either 1-stage heat treatment or 2-stage heat treatment, were researched. The relationship between surface texture characteristics and the chemical properties was identified through molecular weight distribution, insolubility of coal tar, weight loss with temperature increase, coking yield, and polarized light microscope analysis. Rapidly cleared anisotropy texture in cokes was observed in accordance with the coking temperature rise. Quinoline insolubility and toluene insolubility of coal tar increased with a corresponding increases in coking temperature. In particular, the cokes produced by the 2-stage heat treatment (2S-C) showed surface structure of needle cokes at a temperature approximately 50°C lower than the 1-stage heat treatment (1S-C). Additionally, the coking yield of 2S-C increased by approximately 14% in comparison with 1S-C.     

Problems with the mass spectrometric determination of tritium from cold fusion

Among the attempts to measure particles produced in the cold fusion of deuterium in palladium metal is the mass spectrometric observation of tritium. An experiment which has been reported in the popular press involves attaching a hollow Pd electrode to a vacuum chamber and measuring the tritium produced during electrolysis using a mass spectrometer. We present data demonstrating that mass 5 and 6, which could be mistaken for the ions DT⁺ and T₂ ⁺, can arise from ion-molecule reactions in the ionizer of the mass spectrometer giving the ions HD₂ ⁺ and D₃ ⁺. With H₂ and D₂ present in the vacuum chamber, there are at least eight reactions which lead to these triatomic species, and these may contribute to a complex time and pressure dependence of the signals.     

Electron beam modification and functionalization of MWNT for covalent dispersion into polymeric systems

The development of nanotube-based polymer composites with improved mechanical properties and electrical conductivity requires the covalent dispersion of carbon nanotubes to utilize their stress transfer capabilities. Covalent dispersion of nanotubes therefore requires the functionalization of their surface to interact with solvents or monomers. In this work, we have developed a novel method of nanotube surface modification in which dry MWNT are irradiated with a high-energy electron beam (EB) in ambient air environment. Raman spectroscopy was performed to characterize the influence of EB irradiation on nanotubes, namely, variance of the disorder, or D band (∼1360 cm⁻¹) with respect to the graphitic, or G, band (∼1580 cm⁻¹). Raman spectra show increased deformation to the graphitic structure, as well as increased strain on the carbon-carbon bonds, weakening the nanotube. Transmission electron microscopy (TEM) confirms that nanotubes remain intact despite high EB dose. In addition, minimal surface deformation and length reduction occurred on irradiated MWNT.     

Effect of network mesh size and swelling to the drug delivery from pH responsive hydrogels

pH responsive hydrogels are ideal platforms for numerous therapeutic delivery applications, including oral delivery, as they are capable of overcoming the many barriers that must be considered when creating an effective drug delivery system. Understanding of the innate hydrogel network structure and its swelling behavior at environmentally relevant conditions is vital for designing hydrogel network capable of effective controlled drug release. Herein, we explored how to expand traditional techniques of swelling and pore characterization to gain better insight into the performance of anionic microparticles composed of the poly(methyl methacrylate-co-acrylic acid) with varying molar percentage of 10, 20, and 30 mol% of MMA, for controlled release of low-molecular-weight drugs. By evaluating these carrier systems at environmental conditions, we can observe changes in swelling and pore size of the anionic hydrogel networks as a function of MMA, which was then correlated with the release profiles of the small-molecular-weight drug sodium nitrate. With the correlation of the swelling behavior of the networks and the release profiles, we demonstrated how the expansion of swelling parameters at relevant pH values provides further incite for evaluating for the optimal blend for controlled release. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48767.     

Extrusion of highly filled flexible polymer sheet

Highly-filled polymer systems include color masterbatches, feedstocks for powder injection molding, and rigid sheets with high levels of flame retardants, but they have not been explored for flexible sheet. This work investigated the (a) selecting a polymer matrix with enough melt strength and flexibility to form a stable sheet with high filler loading, (b) the maximum achievable filler loading for the sheet, and (c) optimizing the process of extruding a highly-filled flexible polymer system. Extrusion grade low-density polyethylene (LDPE) provided sufficient flexibility and permitted a maximum filler loading of 36 vol% (~78 wt%). Good dispersion of the nanoparticle filler, however, required two passes through multiple screw extruders and a small reduction in the viscosity of the LDPE. Sheet with thickness of 415 μm, surface roughness of <1 μm, and sufficient flexibility was extruded continuously at a rate of 10 m/min., but it required a more traditional coat hanger manifold to prevent filler hang up in the sheet die. The filler particles were distributed uniformly through the core and skin of the sheet, giving the sheet good mechanical properties.     

Development of vitamin E-enriched functional foods: stability of tocotrienols in food systems

Tocotrienols are members of the vitamin E family that provide many nutritional benefits. Developing tocotrienol-fortified functional foods introduces vitamin E into consumers diets without changing their food habits. The purpose of this study was to compare the stability of tocotrienols in bulk form and six food matrices at a fixed dose (40 mg kg⁻¹) under accelerated and conventional storage conditions. The delta- and gamma-tocotrienol content was measured using HPLC, and the sensory attributes were evaluated using triangle and hedonic tests. Tocotrienol in bulk powder was less stable under stressed conditions than in bulk oil, with the powders having approximately 40% and 80% reduction in δ- and γ- after storage and bulk oil with no significant degradation. HPLC analysis demonstrated that tocotrienol content remained unchanged in dry mix lemonade, yogurt, raw and UHT milk, and margarine over time; however, complete degradation of γ- and partial degradation (up to 50%) of δ-tocotrienol was observed in bread during ambient and stressed storage conditions. A significant decrease in the δ-tocotrienol relative concentration was also observed in HTST processed milk samples. Tocotrienol addition was not perceived, and no significant difference in the product attributes and overall liking was reported in the discrimination sensory testing.     

Dioxins,furans, and non-ortho PCBs in Canadian Arctic seabirds

This is the first account of PCDDs, PCDFs, and non-ortho PCBs in Canadian Arctic seabirds. Livers and eggs of thick-billed murres, northern fulmars, and black-legged kittiwakes were collected in 1975 and 1993 from Prince Leopold Island in Lancaster Sound, Canada. Detectable concentrations of PCDDs, PCDFs, and non-ortho PCBs were found in all the Arctic seabird samples analyzed. Of the PCDD congeners assayed, only 2,3,7,8-substituted PCDDs were detected in the samples, whereas non-2,3,7,8-substituted PCDFs were found in addition to 2,3,7,8-substituted PCDFs in some of the samples. The predominant PCDD/F congener found in the livers of all three species was 2,3,4,7,8-PnCDF, both in 1975 and 1993. Concentrations of most dioxins and furans decreased in the fulmars and kittiwakes between 1975 and 1993 but increased in the murres. Of the non-ortho PCBs measured, PCB-126 occurred in the highest concentrations and contributed the majority of the non-ortho PCB-TEQ in all three species in both years. The highest concentrations of dioxins and furans as well as the highest TEQ values were found in the northern fulmar livers in both 1975 and 1993. Concentrations of some of the PCDDs and PCDFs are among the highest reported for Canadian Arctic biota.     

Glucose prevents citrate metabolism by enterococci

Enterococcus faecalis FAIR E-239, growing on glucose plus citrate, metabolized citrate at pH 6.5 or 7.5, but only when glucose had been exhausted; it did not metabolize citrate at pH 5.5 or 8.5. When grown on citrate only, the strain metabolized citrate at all pH values, and two growth rates were apparent. Citrate was mainly metabolized during the second, much slower growth rate. Glucose also inhibited citrate metabolism by E. faecalis FAIR E-237 and FAIR E-259 and Enterococcus faecium FAIR E-338 and FAIR E-371. Glucose-grown resting cells were unable to metabolize citrate. Citrate-grown resting cells had a pH optimum of 4.7 for citrate metabolism but also metabolized significant amounts of citrate at pH 4.2 and 6.5. Resting stationary phase cells used citrate more rapidly than resting log phase cells. Citrate metabolism was faster at citrate levels <10 mM than above 10 mM. These results suggest that some form of catabolite repression is occurring.     

Chemopreventive Potential of Wild Lowbush Blueberry Fruits in Multiple Stages of Carcinogenesis

ABSTRACT: Wild lowbush blueberry fruit extract was fractionated using vacuum chromatography and analyzed for chemopreventive potential using bioassays that test the ability of compounds to inhibit the initiation, promotion, and progression stages of carcinogenesis. A fraction containing phytosterols was active against the initiation stage (quinone reductase assay). However, more polar compounds were inhibitors of later stages of carcinogenesis; a fraction containing flavan-3-ols and fractions containing mainly anthocyanins, phenolic acids, flavan-3-ols, and some proanthocyanidin dimers demonstrated activity against the promotion stage (cyclooxygenase and ornithine decarboxylase assays, respectively), and a proanthocyanidin-rich fraction demonstrated antiproliferation activity (inhibition of cancerous murine hepatocyte proliferation is associated with the progression stage). These results indicate that lowbush blueberries contain a range of compounds that have bioactivity against multiple stages of carcinogenesis, and different types of phenolic compounds are active at different stages.