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Trimethylbenzenes (Interagency Science Discussion Draft)

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The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Effect of Cetane Improver on Combustion and Emission Characteristics of Coal-Derived Sasol Isomerized Paraffinic Kerosene in a Single Cylinder Diesel Engine

Authors: Zheng, Z; Joshi, U; Henein, N; Sattler, E (2015) HERO ID: 2953943

[Less] Sasol isomerized paraffinic kerosene (IPK) is a coal-derived synthetic fuel under consideration as a . . . [More] Sasol isomerized paraffinic kerosene (IPK) is a coal-derived synthetic fuel under consideration as a blending stock with JP-8 for use in military ground vehicles. Since Sasol IPK is a low ignition quality fuel with derived cetane number (DCN) of 31, there is a need to improve its ignition quality. This paper investigates the effect of adding different amounts of Lubrizol 8090 cetane improver to Sasol IPK on increasing its DCN. The experimental investigation was conducted in a single cylinder research type diesel engine. The engine is equipped with a common rail injection system and an open engine control unit. Experiments covered different injection pressures and intake air temperatures. Analysis of test results was made to determine the effect of cetane improver percentage in the coal-derived Sasol IPK blend on auto-ignition, combustion and emissions of carbon monoxide (CO), total unburned hydrocarbon (HC), oxides of nitrogen (NOx), and particulate matter (PM). In addition, the effect of cetane improver on the apparent activation energy of the global auto-ignition reactions was determined.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Aerobic oxidation of p-cresols to 4-hydroxy benzaldehydes catalyzed by cobaltous chloride/NHPI/salen-Cu(II) catalytic system

Authors: Ma, W; Zhang, Y; Li, X; Zhao, J (2015) HERO ID: 3044703

[Less] Oxidation of 2-methoxy-p-cresol, p-cresol, 2-bromo-p-cresol to their corresponding 4-hydroxybenzaldehydes . . . [More] Oxidation of 2-methoxy-p-cresol, p-cresol, 2-bromo-p-cresol to their corresponding 4-hydroxybenzaldehydes with atmospheric molecular oxygen as oxidant and a combination of cobaltous chloride and N-hydroxyphthalimide (NHPI) as catalyst in methanol has been investigated for the first time. The results indicated that the reaction progress was related to the substituents in the structures of the substrates: the electron-donating group methoxy favors the aerobic reaction but the electron-withdrawing group Br is detrimental to the reaction. The introduction of salen-Cu(II) complexes as the third component into the cobaltous chloride/NHPI catalytic system can considerably improve the aerobic oxidation of p-cresol and 2-brom-p-cresol to the corresponding 4-hydroxybenzaldes.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Ignition delay times of conventional and alternative fuels behind reflected shock waves

Authors: Zhu, Y; Li, S; Davidson, DF; Hanson, RK (2015) HERO ID: 2896779

[Less] The auto-ignition characteristics of two distillate jet fuels and fifteen alternative fuels (including . . . [More] The auto-ignition characteristics of two distillate jet fuels and fifteen alternative fuels (including fuel blends) were investigated using shock-tube/laser-absorption methods. Ignition delay times were measured behind reflected shock waves over a range of temperatures, 1047-1520 K, and equivalence ratios, 0.25-2.2, in two pressure and mixture regimes: for fuel/air mixtures at 2.07-8.27 atm, and for fuel/4% oxygen(O-2)/ argon(Ar) mixtures at 15.9-44.0 atm. In both pressure ranges, the ignition delay times of the alternative fuels and the blends with conventional fuels were found to be similar to those of conventional fuels but with some small systematic differences manifesting the different fuel types. In particular, for alternative aviation fuels, alcohol-to-jet fuels were found to be generally less reactive than Fischer-Tropsch paraffinic kerosenes or hydro-processed renewable jet fuels. Comparisons were also made of the ignition delay time data with detailed kinetic modeling for selected fuels. These comparisons show that existing multi-component surrogate/mechanism combinations can successfully predict the behavior of these fuels over the conditions studied. For those fuels lacking kinetic models, the current ignition delay time measurements provide useful target data for development and validation of relevant surrogate mixtures and reaction mechanisms. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Synthesis and mechanical characterization of mechanically strong, polyurea-crosslinked, ordered mesoporous silica aerogels

Authors: Churu, G; Zupancic, B; Mohite, D; Wisner, C; Luo, H; Emri, I; Sotiriou-Leventis, C; Leventis, N; Lu, H (2015) HERO ID: 2897771

[Less] Mechanically strong polymer-crosslinked templated silica aerogel (CTSA) monoliths with ordered tubular . . . [More] Mechanically strong polymer-crosslinked templated silica aerogel (CTSA) monoliths with ordered tubular mesopores were synthesized through an acid-catalyzed, surfactant-templated sol-gel process followed by covalent crosslinking of the elementary building blocks with polyurea. Specifically, a structure-directing reagent (triblock copolymer, Pluronic P123) was used in combination with variable amounts of a micelle-swelling reagent (1,3,5-trimethylbenzene) to regulate the size, shape, morphology of the elementary building blocks, as well as the pore size distribution of acid-catalyzed silica. The structure was subsequently treated with variable concentrations of a diisocyanate that reacts with surface -OH groups as well as residual gelation water adsorbed on the surface of silica. The developing polymer (polyurea) adheres to the walls of the mesoporous tubes and leaves macropores open. Rather than using a typical supercritical fluid (typically from CO2) drying protocol, the polymer-crosslinked materials of this study are strong enough to withstand stresses imposed by evaporating solvents and were dried from pentane under ambient pressure. The morphostructural properties of CTSAs were characterized before and after compression testing using a battery of methods including SEM, TEM and small-angle X-ray scattering. Mechanical properties were investigated using quasi-static compression tests, tensile, high-strain-rate dynamic tests as well as shear creep measurements. In addition, dynamic mechanical analysis as well as heat transfer tests was conducted. The Young's modulus was found to be about 800 MPa while the specific energy absorption was as high as 123 J/g, making this material a prime candidate for ballistic protection.

Mechanically strong polymer-crosslinked templated silica aerogel (CTSA) monoliths with ordered tubular mesopores were synthesized through an acid-catalyzed, surfactant-templated sol-gel process followed by covalent crosslinking of the elementary building blocks with polyurea, leaving macropores open. Using pentane under ambient pressure drying protocol, the CTSAs are strong enough to withstand stresses imposed by evaporating solvents. The mechanical and morphostructural properties of CTSAs were characterized using SEM, TEM and small-angle X-ray scattering (SAXS). The Young's modulus was found to be about 800 MPa while the specific energy absorption was as high as 123 J/g, making this material a prime candidate for energy absorption under impact.TEM/SEM images and SAXS of X-MP4-T045-11/94 templated aerogel. (a) TEM images before compression; (b) TEM images after 85 % compressive strain; (c) SAXS data at different strain. (d) SEM images before compression; (e) SEM images after 23 % strain; (f) SEM images after 83 % strain. Insets of (e) and (f) are the compressive stress-strain curves.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Complex chemical composition of colored surface films formed from reactions of propanal in sulfuric acid at upper troposphere/lower stratosphere aerosol acidities

Authors: Van Wyngarden, AL; Perez-Montano, S; Bui, JVH; Li, ESW; Nelson, TE; Ha, KT; Leong, L; Iraci, LT (2015) Atmospheric Chemistry and Physics 15:4225-4239. HERO ID: 2902441

[Less] Particles in the upper troposphere and lower stratosphere (UT/LS) consist mostly of concentrated sulfuric . . . [More] Particles in the upper troposphere and lower stratosphere (UT/LS) consist mostly of concentrated sulfuric acid (40-80 wt %) in water. However, airborne measurements have shown that these particles also contain a significant fraction of organic compounds of unknown chemical composition. Acid-catalyzed reactions of carbonyl species are believed to be responsible for significant transfer of gas phase organic species into tropospheric aerosols and are potentially more important at the high acidities characteristic of UT/LS particles. In this study, experiments combining sulfuric acid (H2SO4) with propanal and with mixtures of propanal with glyoxal and/or methylglyoxal at acidities typical of UT/LS aerosols produced highly colored surface films (and solutions) that may have implications for aerosol properties. In order to identify the chemical processes responsible for the formation of the surface films, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and H-1 nuclear magnetic resonance (NMR) spectroscopies were used to analyze the chemical composition of the films. Films formed from propanal were a complex mixture of aldol condensation products, acetals and propanal itself. The major aldol condensation products were the dimer (2-methyl-2-pentenal) and 1,3,5-trimethylbenzene that was formed by cyclization of the linear aldol condensation trimer. Additionally, the strong visible absorption of the films indicates that higher-order aldol condensation products must also be present as minor species. The major acetal species were 2,4,6-triethyl-1,3,5-trioxane and longer-chain linear polyacetals which are likely to separate from the aqueous phase. Films formed on mixtures of propanal with glyoxal and/or methylglyoxal also showed evidence of products of cross-reactions. Since cross-reactions would be more likely than self-reactions under atmospheric conditions, similar reactions of aldehydes like propanal with common aerosol organic species like glyoxal and methylglyoxal have the potential to produce significant organic aerosol mass and therefore could potentially impact chemical, optical and/or cloud-forming properties of aerosols, especially if the products partition to the aerosol surface.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

A multifunctional role of trialkylbenzenes for the preparation of aqueous colloidal mesostructured/mesoporous silica nanoparticles with controlled pore size, particle diameter, and morphology

Authors: Yamada, H; Ujiie, H; Urata, C; Yamamoto, E; Yamauchi, Y; Kuroda, K (2015) HERO ID: 3044609

[Less] Both the pore size and particle diameter of aqueous colloidal mesostructured/mesoporous silica nanoparticles . . . [More] Both the pore size and particle diameter of aqueous colloidal mesostructured/mesoporous silica nanoparticles (CMSS/CMPS) derived from tetrapropoxysilane were effectively and easily controlled by the addition of trialkylbenzenes (TAB). Aqueous highly dispersed CMPS with large pores were successfully obtained through removal of surfactants and TAB by a dialysis process. The pore size (from 4 nm to 8 nm) and particle diameter (from 50 nm to 380 nm) were more effectively enlarged by the addition of 1,3,5-triisopropylbenzene (TIPB) than 1,3,5-trimethylbenzene (TMB), and the enlargement did not cause the variation of the mesostructure and particle morphology. The larger molecular size and higher hydrophobicity of TIPB than TMB induce the incorporation of TIPB into micelles without the structural change. When TMB was used as TAB, the pore size of CMSS was also enlarged while the mesostructure and particle morphology were varied. Interestingly, when tetramethoxysilane and TIPB were used, CMSS with a very small particle diameter (20 nm) with concave surfaces and large mesopores were obtained, which may strongly be related to the initial nucleation of CMSS. A judicious choice of TAB and Si sources is quite important to control the mesostructure, size of mesopores, particle diameter, and morphology.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Total Synthesis of Crotophorbolone

Authors: Asaba, T; Katoh, Y; Urabe, D; Inoue, M (2015) HERO ID: 3044615

[Less] The complex ABC-tricyclic structure of crotophorbolone, a derivative of the tigliane diterpenoids, was . . . [More] The complex ABC-tricyclic structure of crotophorbolone, a derivative of the tigliane diterpenoids, was assembled by coupling of simple fragments. The six-membered C-ring fragment, having five contiguous stereocenters, was stereoselectively constructed from (R)-carvone. After attachment of the five-membered A-ring through the π-allyl Stille coupling reaction, the α-alkoxy bridgehead radical reaction effected the endo-cyclization of the seven-membered B-ring by forming the sterically congested bond at C9 and C10 stereospecifically and stereoselectively, respectively. Finally, the functional groups on the 5/7/6-membered ring system were manipulated by rhodium-catalyzed C2 olefin isomerization, C13 decarboxylative oxidation, and C4 hydroxylation, thus completing the first total synthesis of crotophorbolone.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Kinetics of Upgrading of Anisole with Hydrogen Catalyzed by Platinum Supported on Alumina

Authors: Saidi, M; Rostami, P; Rahimpour, HR; Fallah, M; Rahimpour, MR; Gates, BC; Raeissi, S (2015) Energy and Fuels 29:4990-4997. HERO ID: 3044632

[Less] Kinetics of the reactions of anisole, a model compound representative of lignin-derived bio-oils, with . . . [More] Kinetics of the reactions of anisole, a model compound representative of lignin-derived bio-oils, with H-2 catalyzed by Pt/Al2O3, were investigated with a fixed-bed tubular microflow reactor at 573-673 K, 8-14 bar, and space velocities in the range of 3-240 (g of anisole)/(g of catalyst x h). Selectivity conversion data were used as a basis to propose an approximate reaction network and estimate parameters in approximate rate equations. The reactions include the following: anisole conversion to phenol by hydrogenolysis, to 2-methylphenol by transalkylation, to 2,4-dimethylphenol, 2,4,6-trimethylphenol, and 2,3,5,6-tetramethylphenol by transalkylation and alkylation, to benzene by hydrodeoxygenation (HDO), and to hexamethylbenzene by HDO and alkylation. The primary reactions are satisfactorily represented with the approximation that each is first-order in the organic reactant. The apparent activation energy for the hydrogenolysis reaction that leads to phenol formation is approximately 25.3 kJ/mol, and the alkylation is the reaction class characterized by the highest apparent activation energy.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Bulged Invader probes: activated duplexes for mixed-sequence dsDNA recognition with improved thermodynamic and kinetic profiles

Authors: Guenther, DC; Karmakar, S; Hrdlicka, PJ (2015) HERO ID: 3044657

[Less] Double-stranded oligonucleotides with +1 interstrand zipper arrangements of intercalator-functionalized . . . [More] Double-stranded oligonucleotides with +1 interstrand zipper arrangements of intercalator-functionalized nucleotides are energetically activated for recognition of mixed-sequence double-stranded DNA. Incorporation of nonyl (C9) bulges at specific positions of these probes, results in more highly affine (>5-fold), faster (>4-fold) and more persistent dsDNA recognition relative to conventional Invader probes.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Isolable arene sandwiched copper(I) pyrazolates

Authors: Jayaratna, NB; Hettiarachchi, CV; Yousufuddin, M; Dias, HVR (2015) HERO ID: 3044664

[Less] The pi-acid/pi-base adducts of {[3,5-(CF3)(2)Pz]Cu}(3) [Cu-3] and benzene [Bz], mesitylene [Mes] and . . . [More] The pi-acid/pi-base adducts of {[3,5-(CF3)(2)Pz]Cu}(3) [Cu-3] and benzene [Bz], mesitylene [Mes] and naphthalene [Nap] have been isolated. They form columnar structures of the type {[Bz][Cu-3](2)}(infinity), {[Mes][Cu-3]}(infinity) and {[Nap][Cu-3]}(infinity) in the solid state, and are luminescent.