Use of chemically modified enzymes in organic solvents for conversion of coal to nliquides

Reductive enzymes can be used to enhance the conversion of coal to liquids. This can be carried out in both aqueous and organic media, but, in the latter case, the enzymes must be chemically modified so that they are soluble and active in the organic environment. The most effective chemical modification of enzymes is achieved by using reagents such as activated polyethylene glycol or dinitrofluorobenzene that add hydrophobic groups. Use of such modified enzymes in organic solvents such as benzene or pyridine has resulted in the conversion of over 40% of bituminous coal.     

Tunable Dopants with Intrinsic Counterion Separation Reveal the Effects of Electron Affinity on Dopant Intercalation and Free Carrier Production in Sequentially Doped Conjugated Polymer Films

Carrier mobility in doped conjugated polymers is limited by Coulomb interactions with dopant counterions. This complicates studying the effect of the dopant's oxidation potential on carrier generation because different dopants have different Coulomb interactions with polarons on the polymer backbone. Here, dodecaborane (DDB)‐based dopants are used, which electrostatically shield counterions from carriers and have tunable redox potentials at constant size and shape. DDB dopants produce mobile carriers due to spatial separation of the counterion, and those with greater energetic offsets produce more carriers. Neutron reflectometry indicates that dopant infiltration into conjugated polymer films is redox‐potential‐driven. Remarkably, X‐ray scattering shows that despite their large 2‐nm size, DDBs intercalate into the crystalline polymer lamellae like small molecules, indicating that this is the preferred location for dopants of any size. These findings elucidate why doping conjugated polymers usually produces integer, rather than partial charge transfer: dopant counterions effectively intercalate into the lamellae, far from the polarons on the polymer backbone. Finally, it is shown that the IR spectrum provides a simple way to determine polaron mobility. Overall, higher oxidation potentials lead to higher doping efficiencies, with values reaching 100% for driving forces sufficient to dope poorly crystalline regions of the film.     

Mercury control testing in a pulverized lignite-fired system

The Energy & Environmental Research Center (EERC) is evaluating and developing advanced and innovative concepts for controlling Hg emissions from North Dakota lignite-fired power plants with the goal of achieving 50%–90% Hg removal at one-half to three-fourths the current estimated costs. Pilot-scale tests were performed to evaluate potential sorbents and fuel additives for removing Hg from North Dakota lignite (Freedom and Center Mines) combustion flue gases. The Hg sorbents and Hg⁰ oxidation and sorbent enhancement additives were evaluated separately, and most were also tested in combination. A 580 MJ/h (550,000 Btu/h) pulverized coal combustion system was used to conduct sorbent injections and/or lignite additive additions upstream of three particulate control devices (PCDs): 1) an electrostatic precipitator (ESP), 2) a spray dryer and fabric filter, and 3) a retrofit advanced hybrid particulate collector (AHPC) filter (an ESP followed by an AHPC filter). ASTM International Method D6784-02 (Ontario Hydro method) and continuous Hg monitors were used to measure Hg species concentrations across the control devices. The effects of sorbent injection and coal additive addition rates on Hg removal were evaluated for each PCD option. The effects of continuous injection and batch addition of sorbents on the Hg removal performance of the ESP/AHPC filter system were also investigated. Increasing injection and additive rates and improving contact between the sorbents and flue gases generally promoted Hg capture. Most of the coal additives tested significantly enhanced PCD Hg removal, especially in the presence of a sorbent.     

NITROGEN REAGENTS IN METAL ION SEPARATION. PART IX. EXTRACTION OF COBALT AND NICKEL USING IMIDAZOLE DERIVATIVES

ABSTRACT

The extraction capability of derivatives of imidazole towards Co(II) and Ni(II) has been investigated in dilute acid medium in the presence of each of chloride, perchlorate and thiocyanate ions. The influence of the stereochemistry of the substituted imidazole on the extraction behaviour has been investigated. Two-phase potentiometric titrations were employed to determine the nature of the metal species extracted into the organic phases. The electronic spectra of the extracted metal species have been employed to provide information of the nature of such species.     

NITROGEN REAGENTS IN METAL ION SEPARATION. PART VIII SUBSTITUTED IMIDAZOLES AS EXTRACTANTS FOR Cu3+

ABSTRACT

A number of derivatives of imidazole have been synthesized. Their extraction behaviour towards Cu²⁺ in dilute acid medium have been investigated in both chloride and perchlorate media. The influence of electronic and stereochemical effects are discussed. Two-phase potentiometric titrations were employed to determine the two-phase protonation constants and Cu(II) complex species present in the organic phases. The N-decylimidazole derivative has a higher extraction efficiency than the other C-ring substituted imidazoles in spite of their greater protonation constants.     

Effect of electron-beam irradiation on the safety and quality of Fusarium-infected malting barley

Utilization of Fusarium-infected barley for malting may lead to mycotoxin production during malting and decreased malt quality. Electron-beam irradiation may prevent safety and quality defects and allow use of otherwise good quality barley. We evaluated electron-beam irradiation for preventing Fusarium growth and mycotoxin production while maintaining barley-malt quality characteristics. Four barley lots with varying deoxynivalenol (DON) concentrations were irradiated at 0, 2, 4, 6, 8, and 10 kGy. Treated barley was malted in a pilot-scale malting unit. Barley and malt were analyzed for Fusarium infection (FI), germinative energy (GE), aerobic plate counts (APC), mold and yeast counts (MYC), and DON. Malt quality parameters included malt extract, soluble protein, wort color, wort viscosity, free amino nitrogen, alpha-amylase, and diastatic power. FI, APC, and MYC decreased in barley with an increase in dosage. The APC and MYC for malts from barley exposed to 8–10 kGy were slightly higher than in other malted samples indicating that irradiation-resistant microflora could flourish during malting. Barley GE significantly decreased (3–15%) at 8–10 kGy. Although irradiation had no effect on DON in raw barley, DON decreased significantly (60–100%) in finished malts prepared from treated barley (6–10 kGy). Malt quality parameters were slightly affected by electron-beam radiation. The results suggest 6–8 kGy may be effective for reducing FI in barley and DON in malt with minimal effects on malt quality.     

Acculturation, enculturation, parental adherence to Asian cultural values, parenting styles, and family conflict among Asian American college students.

The present study examined the relations between perceived parenting styles and family conflict with data from 149 Asian American college students. Ratings of parenting styles were highest for authoritarian style, followed by authoritative and permissive styles. Tests of mediation revealed that authoritarian parenting significantly explained why parents’ adherence to Asian cultural values was associated with increased family conflict. Tests of moderation showed that as permissive parenting increased, more acculturated participants reported lower family conflict, although the reverse was true for their less acculturated counterparts. When authoritarian parenting increased, integrated, separated, and assimilated participants reported increased family conflict, whereas the marginalized group reported lower family conflict. Finally, assimilated participants reported less family conflicts at higher levels of authoritative parenting in comparison to the integrated, separated, and marginalized groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ambient Protection of Few‐Layer Black Phosphorus via Sequestration of Reactive Oxygen Species

Few‐layer black phosphorous (BP) has emerged as a promising candidate for next‐generation nanophotonic and nanoelectronic devices. However, rapid ambient degradation of mechanically exfoliated BP poses challenges in its practical deployment in scalable devices. To date, the strategies employed to protect BP have relied upon preventing its exposure to atmospheric conditions. Here, an approach that allows this sensitive material to remain stable without requiring its isolation from the ambient environment is reported. The method draws inspiration from the unique ability of biological systems to avoid photo‐oxidative damage caused by reactive oxygen species. Since BP undergoes similar photo‐oxidative degradation, imidazolium‐based ionic liquids are employed as quenchers of these damaging species on the BP surface. This chemical sequestration strategy allows BP to remain stable for over 13 weeks, while retaining its key electronic characteristics. This study opens opportunities to practically implement BP and other environmentally sensitive 2D materials for electronic applications.     

Evaluation of gaseous ozone and hydrogen peroxide treatments for reducing Fusarium survival in malting barley

The use of Fusarium-infected barley for malting can lead to mycotoxin production and decreased malt quality. Methods for treatment of Fusarium-infected barley might prevent these safety and quality defects and allow use of otherwise good-quality barley. Gaseous ozone and hydrogen peroxide (HP) were evaluated for effectiveness in reducing Fusarium survival while maintaining germinative energy (GE) in barley. Gaseous ozone treatments (GOT) included concentrations of 11 and 26 mg/g for 0, 15, 30, and 60 min. HP treatments included 0, 5, 10, and 15% concentrations with exposure times of 0, 5, 10, 15, 20, and 30 min. For GOT, in naturally Fusarium-infected barley, a statistically significant (P < 0.05) decrease (24 to 36%) of Fusarium survival occurred within 15 min of exposure at either concentration. GE was significantly (P < 0.05) affected by 30 min at both concentrations in naturally Fusarium-infected barley, but not in sound barley. GOT did not cause any significant (P > 0.05) effect on GE in sound barley at either concentration over the full 30-min exposure time. For HP, Fusarium survival was significantly decreased (50 to 98%) within 5 min of exposure. With the exception of two treatments (10 and 15% HP agitated for 20 min), GE was not statistically significantly different from the control in naturally Fusarium-infected barley. In sound barley, HP had no significant (P > 0.05) effect on GE. The results suggest that GOT and HP might have potential for treatment of Fusarium-infected malting barley.     

Kinetics of <Superscript>14</Superscript>C distribution after tracer dose of <Superscript>14</Superscript>C-lutein in an adult woman

Lutein is an oxygenated carotenoid (xanthophyll) found in dark green leafy vegetables. High intakes of lutein may lower the risk of age-related macular degeneration. Current understanding of human lutein metabolism as it might occur in vivo is incomplete. Therefore, we conducted a feasibility study where we dosed a normal adult woman with ¹⁴C-lutein (125 nmol, 36 nCi ¹⁴C), dissolved in olive oil (0.5 g/kg body weight) and mixed in a banana shake. Blood, urine, and feces collected before the dose was administered served to establish baseline values. There-after, blood was collected for 63 d following the dose, while feces and urine were collected for 2 wk post-dose. The ¹⁴C contents in plasma, urine, and feces were measured by accelerator MS. The ¹⁴C first appeared in plasma 1 h after dosing and reached its highest level,≈2.08% of dose/L plasma, at 14 h post-dose. The plasma pattern of ¹⁴C did not include a chylomicrons/VLDL (intestinal) peak like that when the same subject received ¹⁴C-β-carotene (a previous test), suggesting that lutein was handled differently from β-carotene by plasma lipoproteins. Lutein had an elimination half-life (t _1/2) of≈10 d. Forty-five percent of the dose of ¹⁴C was eliminated in feces and 10% in urine in the first 2 d after dosing. Quantifying human lutein metabolism is a fertile area for future research.