Serving the Cause: Duty Concepts and Combat Effectiveness in War

DTIC Science & Technology

2010-06-01

War II.10 Like moral factors, the notion of military effectiveness is complex and multi-faceted. Murray and Millet argue that military...The insights derived from this synthesis will provide the common reference point for analysis of the historical examples. Alan Millet and...1988). 4 Allan Millet and Williamson Murray, Military Effectiveness, Vol I, 2. 9 This dynamic interaction is particularly pronounced at the

Dependence of flow and transport through the Williamson River Delta, Upper Klamath Lake, Oregon, on wind, river inflow, and lake elevation

USGS Publications Warehouse

Wood, Tamara M.

2012-01-01

The hydrodynamic model of Upper Klamath and Agency Lakes, Oregon, was used to run 384 realizations of a numerical tracer experiment in order to understand the relative effects of wind, lake elevation, and Williamson River inflow on flow and transport (the movement of water and passively transported constituents) through the Williamson River Delta. Significant findings from this study include: * The replacement rate of water increased in Tulana and Goose Bay with increasing lake elevation, Williamson River inflow, and wind speed. * The fraction of Williamson River inflow passing through either side of the Delta increased with lake elevation and Williamson River inflow. * The partial replacement rate of water in Goose Bay with water from the Williamson River increased with wind speed. * The partial replacement rate of water in Tulana with water from the Williamson River decreased with wind speed. * Strong wind forcing at the water surface caused more of the Williamson River inflow to pass through Goose Bay than through Tulana. * Westerly to northwesterly winds result in more of the Williamson River inflow passing through the Goose Bay side of the Delta than through the Tulana side. * Regression models developed from the tracer experiments can be used to quantify the dependencies between transport and the independent variables to obtain rough estimates of useful quantities such as residence time and steady-state solute concentrations.

Preparation of highly fluorinated diols containing ether linkages.

NASA Technical Reports Server (NTRS)

Rochow, S. E.; Stump, E. C., Jr.

1970-01-01

Hydroxy-terminated perfluoroethers and polyurethane resins derived from ethers have outstanding chemical resistance and good thermal properties. They can be used as potting compounds, coatings, and seals. The hydroxy-terminated ethers serve as intermediates in the synthesis of highly fluorinated elastomers and adhesives.

Synthesis of modified proanthocyanidins: introduction of acyl substituents at C-8 of catechin. Selective synthesis of a C-4-->O-->C-3 ether-linked procyanidin-like dimer.

PubMed

Beauhaire, Josiane; Es-Safi, Nour-Eddine; Boyer, François-Didier; Kerhoas, Lucien; Guernevé, Christine le; Ducrot, Paul-Henri

2005-02-01

The regioselective introduction of substituents at C-8 of (+)-catechin is described, leading to the synthesis of several catechin derivatives with various substitution patterns to be used for the further synthesis of modified proanthocyanidins. Thereafter, a new 3-O-4 ether-linked procyanidin-like derivative was synthesized. Its formation was selectively achieved through TiCl(4)-catalyzed condensation of 4-(2-hydroxyethoxy)tetra-O-benzyl catechin with the 8-trifluoroacetyl adduct of tetra-O-benzyl catechin.

IRON(III) NITRATE-CATALYZED FACILE SYNTHESIS OF DIPHENYLMETHYL (DPM) ETHERS FROM ALCOHOLS

EPA Science Inventory

Diphenyl methyl (DPM) ethers constitute important structural portion of some pharmaceutical entities and also as protective group for hydroxyl groups in synthetic chemistry. DPM ethers are normally prepared using concentrated acids or base as catalysts, which may result in the fo...

Screening of ligands for the Ullmann synthesis of electron-rich diaryl ethers.

PubMed

Otto, Nicola; Opatz, Till

2012-01-01

In the search for new ligands for the Ullmann diaryl ether synthesis, permitting the coupling of electron-rich aryl bromides at relatively low temperatures, 56 structurally diverse multidentate ligands were screened in a model system that uses copper iodide in acetonitrile with potassium phosphate as the base. The ligands differed largely in their performance, but no privileged structural class could be identified.

Composition and process for separating cesium ions from an acidic aqueous solution also containing other ions

DOEpatents

Dietz, Mark L.; Horwitz, E. Philip; Bartsch, Richard A.; Barrans, Jr., Richard E.; Rausch, David

1999-01-01

A crown ether cesium ion extractant is disclosed as is its synthesis. The crown ether cesium ion extractant is useful for the selective purification of cesium ions from aqueous acidic media, and more particularly useful for the isolation of radioactive cesium-137 from nuclear waste streams. Processes for isolating cesium ions from aqueous acidic media using the crown ether cesium extractant are disclosed as are processes for recycling the crown ether cesium extractant and processes for recovering cesium from a crown ether cesium extractant solution.

Composition and process for separating cesium ions from an acidic aqueous solution also containing other ions

DOEpatents

Dietz, M.L.; Horwitz, E.P.; Bartsch, R.A.; Barrans, R.E. Jr.; Rausch, D.

1999-03-30

A crown ether cesium ion extractant is disclosed as is its synthesis. The crown ether cesium ion extractant is useful for the selective purification of cesium ions from aqueous acidic media, and more particularly useful for the isolation of radioactive cesium-137 from nuclear waste streams. Processes for isolating cesium ions from aqueous acidic media using the crown ether cesium extractant are disclosed as are processes for recycling the crown ether cesium extractant and processes for recovering cesium from a crown ether cesium extractant solution. 4 figs.

Synthesis of unsymmetrical benzil licoagrodione.

PubMed

Worayuthakarn, Rattana; Boonya-udtayan, Sasiwadee; Arom-oon, Eakarat; Ploypradith, Poonsakdi; Ruchirawat, Somsak; Thasana, Nopporn

2008-09-19

A synthesis of unsymmetrical 1,2-diarylethane-1,2-dione is reported involving the intramolecular cyclization of anionic benzylic ester of the aryl benzyl ether followed by oxidation employing dioxirane. With the use of microwave irradiation, licoagrodione was prepared from Claisen rearrangement of the corresponding allyl phenyl ether 1,2-diketone readily available from the Lindlar's reduction of the corresponding alkyne derivative. Subsequent removal of protecting groups then furnished the desired product.

Ruthenium-Catalyzed Synthesis of Dialkoxymethane Ethers Utilizing Carbon Dioxide and Molecular Hydrogen.

PubMed

Thenert, Katharina; Beydoun, Kassem; Wiesenthal, Jan; Leitner, Walter; Klankermayer, Jürgen

2016-09-26

The synthesis of dimethoxymethane (DMM) by a multistep reaction of methanol with carbon dioxide and molecular hydrogen is reported. Using the molecular catalyst [Ru(triphos)(tmm)] in combination with the Lewis acid Al(OTf)3 resulted in a versatile catalytic system for the synthesis of various dialkoxymethane ethers. This new catalytic reaction provides the first synthetic example for the selective conversion of carbon dioxide and hydrogen into a formaldehyde oxidation level, thus opening access to new molecular structures using this important C1 source. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Novel alkyd-type coating resins produced using cationic polymerization

DOE PAGES

Chisholm, Bret J.; Kalita, Harjyoti; Alam, Samim; ...

2015-05-06

Novel, partially bio-based poly(vinyl ether) copolymers derived from soybean oil and cyclohexyl vinyl ether (CHVE) were produced by cationic polymerization and investigated for application as alkyd-type surface coatings. Compared to conventional alkyd resins, which are produced by high temperature melt condensation polymerization, the poly(v9nyl ether)s provide several advantages. These advantages include milder, more energy efficient polymer synthesis, elimination of issues associated with gelation during polymer synthesis, production of polymers with well-defined composition and relatively narrow molecular weight distribution, and elimination of film formation and physical property issues associated with entrained monomers, dimers, trimers, etc. The results of the studied showedmore » that the thermal, mechanical, and physical properties of the coatings produced from these novel polymers varied considerably as a function of polymer composition and cure temperature. Overall, the results suggest a good potential for these novel copolymers to be used for coatings cured by autoxidation.« less

Direct From Minnesota--E. G. Williamson

ERIC Educational Resources Information Center

Ewing, Dorlesa Barmettler

1975-01-01

Reminisces about E. G. Williamson, his personality, childhood and philosophy of life which involved striving to achieve excellence. Through an interview format, the author explores Williamson's views about counseling theory and practice, Carl Rogers, educating counselors, the development of counseling in the future, and the history of counseling…

A Tetrazine-Labile Vinyl Ether Benzyloxycarbonyl Protecting Group (VeZ): An Orthogonal Tool for Solid-Phase Peptide Chemistry.

PubMed

Staderini, Matteo; Gambardella, Alessia; Lilienkampf, Annamaria; Bradley, Mark

2018-06-01

The vinyl ether benzyloxycarbonyl (VeZ) protecting group is selectively cleaved by treatment with tetrazines via an inverse electron-demand Diels-Alder reaction. This represents a new orthogonal protecting group for solid-phase peptide synthesis, with Fmoc-Lys(VeZ)-OH as a versatile alternative to Fmoc-Lys(Alloc)-OH and Fmoc-Lys(Dde)-OH, as demonstrated by the synthesis of two biologically relevant cyclic peptides.

Eco-friendly synthesis, physicochemical studies, biological assay and molecular docking of steroidal oxime-ethers

PubMed Central

Alam, Mahboob; Lee, Dong-Ung

2015-01-01

The aim of this study was to report the synthesis of biologically active compounds; 7-(2′-aminoethoxyimino)-cholest-5-ene (4), a steroidal oxime-ether and its derivatives (5, 6) via a facile microwave assisted solvent free reaction methodology. This new synthetic, eco-friendly, sustainable protocol resulted in a remarkable improvement in the synthetic efficiency (85-93 % yield) and high purity using basic alumina. The synthesized compounds were screened for their antibacterial against six bacterial strains by disc diffusion method and antioxidant potential by DPPH assay. The binding capabilities of a compound 6 exhibiting good antibacterial potential were assessed on the basis of molecular docking studies and four types of three-dimensional molecular field descriptors. Moreover the structure-antimicrobial activity relationships were studied using some physicochemical and quantum-chemical parameters with GAMESS interface as well as WebMO Job Manager by using the basic level of theory. Hence, this synthetic approach is believed to provide a better scope for the synthesis of steroidal oxime-ether analogues and will be a more practical alternative to the presently existing procedures. Moreover, detailed in silico docking studies suggested the plausible mechanism of steroidal oxime-ethers as effective antimicrobial agents. PMID:27330525

Phenylethynl-terminated poly(arylene ethers)

NASA Technical Reports Server (NTRS)

Jensen, Brian J. (Inventor); Bryant, Robert G. (Inventor); Hergenrother, Paul M. (Inventor)

1993-01-01

Phenylethynyl-terminated poly(arylene ethers) are prepared in a wide range of molecular weights by adjusting monomer ratio and adding an appropriate amount of 4-fluoro- 4'-phenylethynyl benzophenone during polymer synthesis. The resulting phenylethynyl-terminated poly(arylene ethers) react and crosslink upon curing for one hour at 350 C to provide materials with improved solvent resistance, higher modulus, and better high temperature properties than the linear, uncrosslinked polymers.

α-Diazo oxime ethers for N-heterocycle synthesis.

PubMed

Choi, Subin; Ha, Sujin; Park, Cheol-Min

2017-06-01

This Feature Article introduces the preparation and synthetic utility of α-diazo oxime ethers. α-Oximino carbenes are useful synthons for N-heterocycles, and can be easily prepared from α-diazo oxime ethers as precursors. We begin with the preparation of α-diazo oxime ethers and their application in [3+2] cycloaddition. It turns out that the nature of metals bound to carbenes plays a crucial role in modulating the reactivity of α-oximino carbenes, in which copper carbenes smoothly react with enamines, whereas the less reactive enol ethers and nitriles require gold carbenes. In Section 3.2, a discussion on N-O and C-H bond activation is presented. Carbenes derived from diazo oxime ethers show unique reactivity towards N-O and C-H bond activation, in which the proximity of the two functionalities, carbene and oxime ether, dictates the preferred reaction pathways toward pyridines, pyrroles, and 2H-azirines. In Section 3.3, the development of tandem reactions based on α-diazo oxime ethers is discussed. The nature of carbenes in which whether free carbenes or metal complexes are involved dissects the pathway and forms different types of 2H-azirines. The 2H-azirine formation turned out to be an excellent platform for the tandem synthesis of N-heterocycles including pyrroles and pyridines. In the last section, we describe the electrophilic activation of 2H-azirines with vinyl carbenes and oximino carbenes. The resulting azirinium species undergo rapid ring expansion rearrangements to form pyridines and pyrazines.

1. General view to northwest along Williamson Drive, showing, L ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. General view to northwest along Williamson Drive, showing, L to R: medical Officer's Quarters B (HABS No. VA-1287-E) and Medical Officer's Quarters C - Portsmouth Naval Hospital, Medical Officer's Quarters C, West side Williamson Drive, 400 feet South of Rixey Drive, Portsmouth, Portsmouth, VA

Stereocontrolled Cyanohydrin Ether Synthesis through Chiral Brønsted Acid-Mediated Vinyl Ether Hydrocyanation

PubMed Central

Lu, Chunliang; Su, Xiaoge; Floreancig, Paul E.

2013-01-01

Vinyl ethers can be protonated to generate oxocarbenium ions that react with Me3SiCN to form cyanohydrin alkyl ethers. Reactions that form racemic products proceed efficiently upon converting the vinyl ether to an α-chloro ether prior to cyanide addition in a pathway that proceeds through Brønsted acid-mediated chloride ionization. Enantiomerically enriched products can be accessed by directly protonating the vinyl ether with a chiral Brønsted acid to form a chiral ion pair. Me3SiCN acts as the nucleophile and PhOH serves as a stoichiometric proton source in a rare example of an asymmetric bimolecular nucleophilic addition reaction into an oxocarbenium ion. Computational studies provide a model for the interaction between the catalyst and the oxocarbenium ion. PMID:23968162

A new route to synthesize aryl acetates from carbonylation of aryl methyl ethers

PubMed Central

Yang, Youdi; Li, Shaopeng; Han, Buxing

2018-01-01

Ether bond activation is very interesting because the synthesis of many valuable compounds involves conversion of ethers. Moreover, C–O bond cleavage is also very important for the transformation of biomass, especially lignin, which abundantly contains ether bonds. Developing efficient methods to activate aromatic ether bonds has attracted much attention. However, this is a challenge because of the inertness of aryl ether bonds. We proposed a new route to activate aryl methyl ether bonds and synthesize aryl acetates by carbonylation of aryl methyl ethers. The reaction could proceed over RhCl3 in the presence of LiI and LiBF4, and moderate to high yields of aryl acetates could be obtained from transformation of various aryl methyl ethers with different substituents. It was found that LiBF4 could assist LiI to cleave aryl methyl ether bonds effectively. The reaction mechanism was proposed by a combination of experimental and theoretical studies. PMID:29795781

Concise copper-catalyzed synthesis of tricyclic biaryl ether-linked aza-heterocyclic ring systems.

PubMed

Mestichelli, Paola; Scott, Matthew J; Galloway, Warren R J D; Selwyn, Jamie; Parker, Jeremy S; Spring, David R

2013-11-01

A new method for the synthesis of tricyclic biaryl ether-linked ring systems incorporating seven-, eight-, and nine-membered ring amines is presented. In the presence of catalytic quantities of copper(I), readily accessible acyclic precursors undergo an intramolecular carbon-oxygen bond-forming reaction facilitated by a "templating" chelating nitrogen atom. The methodology displays a broad substrate scope, is practical, and generates rare and biologically interesting tricyclic heteroaromatic products that are difficult to access by other means.

Homogeneous catalyst formulations for methanol production

DOEpatents

Mahajan, Devinder; Sapienza, Richard S.; Slegeir, William A.; O'Hare, Thomas E.

1991-02-12

There is disclosed synthesis of CH.sub.3 OH from carbon monoxide and hydrogen using an extremely active homogeneous catalyst for methanol synthesis directly from synthesis gas. The catalyst operates preferably between 100.degree.-150.degree. C. and preferably at 100-150 psia synthesis gas to produce methanol. Use can be made of syngas mixtures which contain considerable quantities of other gases, such as nitrogen, methane or excess hydrogen. The catalyst is composed of two components: (a) a transition metal carbonyl complex and (b) an alkoxide component. In the simplest formulation, component (a) is a complex of nickel tetracarbonyl and component (b) is methoxide (CH.sub.3 O.sup.-), both being dissolved in a methanol solvent system. The presence of a co-solvent such as p-dioxane, THF, polyalcohols, ethers, hydrocarbons, and crown ethers accelerates the methanol synthesis reaction.

Homogeneous catalyst formulations for methanol production

DOEpatents

Mahajan, Devinder; Sapienza, Richard S.; Slegeir, William A.; O'Hare, Thomas E.

1990-01-01

There is disclosed synthesis of CH.sub.3 OH from carbon monoxide and hydrogen using an extremely active homogeneous catalyst for methanol synthesis directly from synthesis gas. The catalyst operates preferably between 100.degree.-150.degree. C. and preferably at 100-150 psia synthesis gas to produce methanol. Use can be made of syngas mixtures which contain considerable quantities of other gases, such as nitrogen, methane or excess hydrogen. The catalyst is composed of two components: (a) a transition metal carbonyl complex and (b) an alkoxide component. In the simplest formulation, component (a) is a complex of nickel tetracarbonyl and component (b) is methoxide (CH.sub.3 O.sup.13 ), both being dissolved in a methanol solvent system. The presence of a co-solvent such as p-dioxane, THF, polyalcohols, ethers, hydrocarbons, and crown ethers accelerates the methanol synthesis reaction.

Evaluation of Efficient and Practical Methods for the Preparation of Functionalized Aliphatic Trifluoromethyl Ethers.

PubMed

Sokolenko, Taras M; Dronkina, Maya I; Magnier, Emmanuel; Yagupolskii, Lev M; Yagupolskii, Yurii L

2017-05-14

The "chlorination/fluorination" technique for aliphatic trifluoromethyl ether synthesis was investigated and a range of products with various functional groups was prepared. The results were compared with oxidative desulfurization-fluorination of xanthates with the same structure.

How Developmental Psychology and Robotics Complement Each Other

DTIC Science & Technology

2000-01-01

Breazeal, Marjanovic , Scassellati & Williamson), and a system for regulating interaction intensities (Breazeal & Scassellati) have also been implemented...have been previously reported (Scassellati; Scas- sellati; Brooks, Breazeal, Marjanovic , Scassellati & Williamson; Marjanovic et al.; Brooks, (Ferrell... Marjanovic , M., Scassel- lati, B. & Williamson, M. M. (1999), The Cog Project: Building a Humanoid Robot, in C. L. Nehaniv, ed., `Computation for

Spiroborate Ester-Mediated Asymmetric Synthesis of β-Hydroxy Ethers and its Conversion to Highly Enantiopure β-Amino Ethers

PubMed Central

Huang, Kun; Ortiz-Marciales, Margarita; Correa, Wildeliz; Pomales, Edgardo; López, Xaira Y.

2009-01-01

Borane-mediated reduction of aryl and alkyl ketones with α-aryl- and α-pyridyloxy groups affords β-hydroxy ethers in high enantiomeric purity (up to 99% ee) and in good yield, using as catalyst 10 mol % of spiroborate ester 1 derived from (S)-diphenylprolinol. Representative β-hydroxy ethers are successfully converted to β-amino ethers, with minor epimerization, by phthalimide substitution under Mitsunobu’s conditions followed by hydrazinolysis, to obtain primary amino ethers or by imide reduction with borane to afford β-2,3-dihydro-1H-isoindol ethers. Non-racemic Mexiletine and nAChR analogues with potential biological activity are also synthesized in excellent yield by mesylation of key β-hydroxy pyridylethers and substitution with 5, 6 and 7 member ring heterocyclic amines. PMID:19413288

Convenient approaches to synthesis of furanoid sugar-aza-crown ethers from C-ribosyl azido aldehyde via a reductive amination/amidation.

PubMed

Hsieh, Yu-Chi; Chir, Jiun-Ly; Zou, Wei; Wu, Hsiu-Han; Wu, An-Tai

2009-05-26

A short and highly efficient route to the alpha-anomer of a furanoid sugar-aza-crown ether was developed by a one-pot reductive amination of an alpha-anomer C-ribosyl azido aldehyde. In addition, the beta-anomer furanoid sugar-aza-crown ether was synthesized from a linear disaccharide precursor via amidation and then followed by microwave-assisted amide reduction.

Research in acetylene containing monomers

NASA Technical Reports Server (NTRS)

Ogliaruso, M. A.

1976-01-01

The preparation of precursor bisbenzils with pendant acetylene linkages for use in the synthesis of new aromatic poly (phenyl quinoxalines) was investigated. Attempts to condense para, para prime-dibromo benzil and potassium acetylide in liquid ammonia and in toluene, to prepare 4-phenyl acetyl phenyl ether, 4-(paraacetylphenyl) acetyl phenyl ether, 4-phenyl acetyl-4 primeacetyl phenyl acetyl phenyl ether, the reaction of 4-phenyl acetyl phenyl ether with Villsmeier reagent to prepare 4-(beta-chloro cinnamaldehyde) phenyl ether, the reaction of 4-(para-acetyl phenyl) acetyl phenyl ether with Villsmeier reagent, and the oxidation of bibenzil to prepare benzil are described. The reactions of phenyl acetylene with oxidizing agent, of phenyl acetylene with bromine, of 1,1,2,2-tetrabromo ethyl benzene with zinc and with oxidizing agent are described.

A four-component coupling reaction of carbon dioxide, amines, cyclic ethers and 3-triflyloxybenzynes for the synthesis of functionalized carbamates.

PubMed

Xiong, Wenfang; Qi, Chaorong; Cheng, Ruixiang; Zhang, Hao; Wang, Lu; Yan, Donghao; Jiang, Huanfeng

2018-04-27

A novel four-component coupling reaction of carbon dioxide, amines, cyclic ethers and 3-triflyloxybenzynes has been developed for the first time, providing an efficient method for the synthesis of a series of functionalized carbamate derivatives in moderate to high yields. The process proceeds under mild, transition metal-free and fluoride-free conditions, leading to the formation of two new C-O bonds, one new C-N bond and one C-H bond in a single step.

Synthesis of two and antibacterial activity of one novel oxime ether derivatives of erythromycin A.

PubMed

Dondas, H A; Yaktubay, N

2003-10-01

The synthesis of novel erythromycin A 9-O-(2-ethenesulfony-ethyl)-oxime and erythromycin A 9-O-(3-oxo-butyl)-oxime from erythromycin A (EA) by the Michael reaction is described and to describe the effects of transformation of ketone in position 9 of EA to an oxime ether. This transformation occurred in a single step without protecting of any functional moiety of erythromycin oxime and zero waste manner in good yield. The antibacterial screen of EA 9-O-(2-ethenesulfony-ethyl)-oxime is also reported.

Asymmetric Synthesis of Rauhut-Currier type Products by a Regioselective Mukaiyama Reaction under Bifunctional Catalysis.

PubMed

Frias, María; Mas-Ballesté, Rubén; Arias, Saira; Alvarado, Cuauhtemoc; Alemán, José

2017-01-18

The reactivity and the regioselective functionalization of silyl-diene enol ethers under a bifunctional organocatalyst provokes a dramatic change in the regioselectivity, from the 1,5- to the 1,3-functionalization. This variation makes possible the 1,3-addition of silyl-dienol ethers to nitroalkenes, giving access to the synthesis of tri- and tetrasubstituted double bonds in Rauhut-Currier type products. The process takes place under smooth conditions, nonanionic conditions, and with a high enantiomeric excess. A rational mechanistic pathway is presented based on DFT and mechanistic experiments.

Replacement solvents for use in chemical synthesis

DOEpatents

Molnar, Linda K.; Hatton, T. Alan; Buchwald, Stephen L.

2001-05-15

Replacement solvents for use in chemical synthesis include polymer-immobilized solvents having a flexible polymer backbone and a plurality of pendant groups attached onto the polymer backbone, the pendant groups comprising a flexible linking unit bound to the polymer backbone and to a terminal solvating moiety. The polymer-immobilized solvent may be dissolved in a benign medium. Replacement solvents for chemical reactions for which tetrahydrofuran or diethyl may be a solvent include substituted tetrahydrofurfuryl ethers and substituted tetrahydro-3-furan ethers. The replacement solvents may be readily recovered from the reaction train using conventional methods.

Synthesis and application of polyepoxide cardanol glycidyl ether as biobased polyepoxide reactive diluent for epoxy resin

USDA-ARS?s Scientific Manuscript database

Polyepoxide cardanol glycidyl ether (PECGE), a novel cardanol derivative, was synthesized and used as reactive diluent for petroleum-based epoxy resin in this work. The synthetic condition was first optimized, and the resultant PECGE diluent was characterized using Fourier transform infrared spectro...

Humanoid Robots: A New Kind of Tool

DTIC Science & Technology

2000-01-01

Breazeal (Ferrell), R. Irie, C. C. Kemp, M. J. Marjanovic , B. Scassellati, M. M. Williamson, Alternate Essences of Intelligence, AAAI 1998. 2 R. A. Brooks, C...Breazeal, M. J. Marjanovic , B. Scassellati, M. M. Williamson, The Cog Project: Building a Humanoid Robot, Computation fbr Metaphors, Analogy and...Functions, Vol. 608, 1990, New York Academy of Sciences, pp. 637-676. 7 M. J. Marjanovic , B. Scassellati, M. M. Williamson, Self-Taught Visually-Guided

Catalytic Synthesis of Oxygenates: Mechanisms, Catalysts and Controlling Characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klier, Kamil; Herman, Richard G

2005-11-30

This research focused on catalytic synthesis of unsymmetrical ethers as a part of a larger program involving oxygenated products in general, including alcohols, ethers, esters, carboxylic acids and their derivatives that link together environmentally compliant fuels, monomers, and high-value chemicals. The catalysts studied here were solid acids possessing strong Brnsted acid functionalities. The design of these catalysts involved anchoring the acid groups onto inorganic oxides, e.g. surface-grafted acid groups on zirconia, and a new class of mesoporous solid acids, i.e. propylsulfonic acid-derivatized SBA-15. The former catalysts consisted of a high surface concentration of sulfate groups on stable zirconia catalysts. Themore » latter catalyst consists of high surface area, large pore propylsulfonic acid-derivatized silicas, specifically SBA-15. In both cases, the catalyst design and synthesis yielded high concentrations of acid sites in close proximity to one another. These materials have been well-characterization in terms of physical and chemical properties, as well as in regard to surface and bulk characteristics. Both types of catalysts were shown to exhibit high catalytic performance with respect to both activity and selectivity for the bifunctional coupling of alcohols to form ethers, which proceeds via an efficient SN2 reaction mechanism on the proximal acid sites. This commonality of the dual-site SN2 reaction mechanism over acid catalysts provides for maximum reaction rates and control of selectivity by reaction conditions, i.e. pressure, temperature, and reactant concentrations. This research provides the scientific groundwork for synthesis of ethers for energy applications. The synthesized environmentally acceptable ethers, in part derived from natural gas via alcohol intermediates, exhibit high cetane properties, e.g. methylisobutylether with cetane No. of 53 and dimethylether with cetane No. of 55-60, or high octane properties, e.g. diisopropylether with blending octane No. of 105, and can replace aromatics in liquid fuels.« less

Effects of a diphenyl-ether herbicide, oxyfluorfen, on human BFU-E/CFU-E development and haemoglobin synthesis.

PubMed

Rio, B; Parent-Massin, D; Lautraite, S; Hoellinger, H

1997-02-01

The diphenyl-ether herbicides exert their phytotoxic activity by preventing chlorophyll formation in plants as a result of inhibition of protoporphyrinogen oxidase. This enzyme is the last step of the common pathway for chlorophyll and haem biosynthesis. The aim of this work is to determine whether herbicide inhibitors of plant protoporphyrinogen oxidase could act on the human protoporphyrinogen oxidase involved in haemoglobin synthesis and cause heamatologic diseases. Human erythroblastic progenitors (BFU-E/CFU-E: Burst Forming Unit-Erythroid and Colony Forming Unit-Erythroid) were exposed to oxyfluorfen, a diphenyl-ether herbicide in the presence of erythropoietin, and the haematoxicity evaluated in vitro by scoring the development of BFU-E/CFU-E colonies after 7 and 14 days of culture. The toxic effect on differentiation has been evaluated using four criteria: morphology, total protein, total porphyrin, and haemoglobin content. The study of BFU-E/CFU-E proliferation and differentiation showed a cytotoxic effect of oxyfluorfen only at very high concentrations. In contrast, haemoglobin synthesis can be inhibited by concentration of oxyfluorfen (10(-4) M) that have no adverse effect on cellular proliferation.

Development of a stereoselective and scalable process for the preparation of a methylcyclobutanol-pyridyl ether.

PubMed

Kuethe, Jeffrey T; Basu, Kallol; Orr, Robert K; Ashley, Eric; Poirier, Marc; Tan, Lushi

2018-02-15

The evolution of a scalable process for the preparation of methylcyclobutanol-pyridyl ether 1 is described. Key aspects of this development including careful control of the stereochemistry, elimination of chromatography, and application to kilogram-scale synthesis are addressed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Guide to Understanding Apert Syndrome

MedlinePlus

... with the physician prior to and throughout treatment. Design and Production by Robin Williamson, Williamson Creative Services, Inc., Carrollton, TX. © 2005 Children’s Craniofacial Association, Dallas, ...

Synthesis and structural analysis of Fe doped TiO2 nanoparticles using Williamson Hall and Scherer Model

NASA Astrophysics Data System (ADS)

Patle, L. B.; Labhane, P. K.; Huse, V. R.; Gaikwad, K. D.; Chaudhari, A. L.

2018-05-01

The nanoparticles of Pure and doped Ti1-xFexO were synthesized by modified co-precipitation method successfully with nominal composite of x=0.0, 0.01, 0.03 and 0.05 at room temperature. The precursors were further calcined at 500°C for 6hrs in muffle furnace which results in the formation of different TiO2 phase compositions. The structural analysis carried out by XRD (Bruker D8 Cu-Kα1). X-ray peak broadening analysis was used to evaluate the crystalline sizes, the lattice parameters, atomic packing fraction, c/a ratio, X-ray density and Volume of unit cell. The Williamson Hall analysis is used to find grain size and Strain of prepared TiO2 nano particles. Crystalline TiO2 with a Tetragonal Anatase phase is confirmed by XRD results. The grain size of pure and Fe doped samples were found in the range of 10nm to 18nm. All the physical parameters of anatase tetragonal TiO2 nanoparticles were calculated more precisely using modified W-H plot a uniform deformation model (UDM). The results calculated from both the techniques were approximately similar.

Biobased Epoxy Resins from Deconstructed Native Softwood Lignin.

PubMed

van de Pas, Daniel J; Torr, Kirk M

2017-08-14

The synthesis of novel epoxy resins from lignin hydrogenolysis products is reported. Native lignin in pine wood was depolymerized by mild hydrogenolysis to give an oil product that was reacted with epichlorohydrin to give epoxy prepolymers. These were blended with bisphenol A diglycidyl ether or glycerol diglycidyl ether and cured with diethylenetriamine or isophorone diamine. The key novelty of this work lies in using the inherent properties of the native lignin in preparing new biobased epoxy resins. The lignin-derived epoxy prepolymers could be used to replace 25-75% of the bisphenol A diglycidyl ether equivalent, leading to increases of up to 52% in the flexural modulus and up to 38% in the flexural strength. Improvements in the flexural strength were attributed to the oligomeric products present in the lignin hydrogenolysis oil. These results indicate lignin hydrogenolysis products have potential as sustainable biobased polyols in the synthesis of high performance epoxy resins.

Synthesis of neutral ether lipid monoalkyl-diacylglycerol by lipid acyltransferases[S

PubMed Central

Ma, Zhengping; Onorato, Joelle M.; Chen, Luping; Nelson, David W.; Yen, Chi-Liang Eric; Cheng, Dong

2017-01-01

In mammals, ether lipids exert a wide spectrum of signaling and structural functions, such as stimulation of immune responses, anti-tumor activities, and enhancement of sperm functions. Abnormal accumulation of monoalkyl-diacylglycerol (MADAG) was found in Wolman’s disease, a human genetic disorder defined by a deficiency in lysosomal acid lipase. In the current study, we found that among the nine recombinant human lipid acyltransferases examined, acyl-CoA:diacylglycerol acyltransferase (DGAT)1, DGAT2, acyl-CoA:monoacylglycerol acyltransferase (MGAT)2, MGAT3, acyl-CoA:wax-alcohol acyltransferase 2/MFAT, and DGAT candidate 3 were able to use 1-monoalkylglycerol (1-MAkG) as an acyl acceptor for the synthesis of monoalkyl-monoacylglycerol (MAMAG). These enzymes demonstrated different enzymatic turnover rates and relative efficiencies for the first and second acylation steps leading to the synthesis of MAMAG and MADAG, respectively. They also exhibited different degrees of substrate preference when presented with 1-monooleoylglycerol versus 1-MAkG. In CHO-K1 cells, treatment with DGAT1 selective inhibitor, XP-620, completely blocked the synthesis of MADAG, indicating that DGAT1 is the predominant enzyme responsible for the intracellular synthesis of MADAG in this model system. The levels of MADAG in the adrenal gland of DGAT1 KO mice were reduced as compared with those of the WT mice, suggesting that DGAT1 is a major enzyme for the synthesis of MADAG in this tissue. Our findings indicate that several of these lipid acyltransferases may be able to synthesize neutral ether lipids in mammals. PMID:28420705

Use of aluminum phosphate as the dehydration catalyst in single step dimethyl ether process

DOEpatents

Peng, Xiang-Dong; Parris, Gene E.; Toseland, Bernard A.; Battavio, Paula J.

1998-01-01

The present invention pertains to a process for the coproduction of methanol and dimethyl ether (DME) directly from a synthesis gas in a single step (hereafter, the "single step DME process"). In this process, the synthesis gas comprising hydrogen and carbon oxides is contacted with a dual catalyst system comprising a physical mixture of a methanol synthesis catalyst and a methanol dehydration catalyst. The present invention is an improvement to this process for providing an active and stable catalyst system. The improvement comprises the use of an aluminum phosphate based catalyst as the methanol dehydration catalyst. Due to its moderate acidity, such a catalyst avoids the coke formation and catalyst interaction problems associated with the conventional dual catalyst systems taught for the single step DME process.

SYNTHESIS OF NOVEL CROWN ETHERS BEARING THE exo-cis-2,3-NORBORNYL GROUP AS POTENTIAL Na+ AND K+ EXTRACTANTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robeson, R.M.; Bonnesen, P.

2007-01-01

The synthesis of a series of novel dinorbornyl-16-crown-5 and dinorbornyl-18-crown-6 ethers that incorporate the exo-cis-2,3-norbornyl moiety within the macrocycle framework is described. The key starting material for the crown ethers, exo-cis-2,3-norbornanediol, was successfully prepared on a large (>30g) scale in 88% yield from norbornylene by osmium tetroxide-catalyzed hydroxylation. The syn and anti isomers of the dinorbornyl-16-crown-5 ether family were prepared using diethylene glycol with ring closure achieved using a methallyl linkage. The isomers cis-syn-cis and cis-anti-cis di-norbornano-15-methyleno-16-crown-5 (6A and 6B) could be separated using column chromatography, and a single crystal of the syn isomer 6A suitable for X-ray crystal structuremore » analysis was obtained, thereby confi rming the syn orientation. The syn and anti isomers of the dinorbornyl-18-crown-6 ether family were successfully prepared employing a different synthetic strategy, involving the potassium–templated cyclization of two bis-hydroxyethoxy-substituted exo-cis-2,3-norbornyl groups under high dilution conditions. Attempts to fully separate cis-syn-cis di-norbornano-18-crown-6 (10A) and cis-anti-cis di-norbornano-18-crown-6 (10B) from one another using column chromatography were unsuccessful. All intermediates and products were checked for purity using either thin layer chromatography or gas chromatography, and characterized by proton and carbon NMR. Crown ethers 6AB and 10AB are to our knowledge the fi rst crown ethers to incorporate the exo-cis-2,3-norbornyl moiety into the crown ring to be successfully synthesized and characterized.« less

Synthesis and structure-activity relationship of dicationic diaryl ethers as novel potent anti-MRSA and anti-VRE agents.

PubMed

Hu, Laixing; Kully, Maureen L; Boykin, David W; Abood, Norman

2009-08-15

A series of dicationic diaryl ethers have been synthesized and evaluated for in vitro antibacterial activities, including drug resistant bacterial strains. Most of these compounds have shown potent antibacterial activities. Several compounds, such as piperidinyl and thiomorpholinyl compounds 9e and 9l, improved the antimicrobial selectivity and kept potent anti-MRSA and anti-VRE activity. The most potent bis-indole diphenyl ether 19 exhibited anti-MRSA MIC value of 0.06 microg/mL and enhanced antimicrobial selectivity.

Design and synthesis of aryl ether and sulfone hydroxamic acids as potent histone deacetylase (HDAC) inhibitors.

PubMed

Pabba, Chittari; Gregg, Brian T; Kitchen, Douglas B; Chen, Zhen Jia; Judkins, Angela

2011-01-01

A series of novel hydroxamic acid based histone deacetylases (HDAC) inhibitors with aryl ether and aryl sulfone residues at the terminus of a substituted, unsaturated 5-carbon spacer moiety have been synthesized for the first time and evaluated. Compounds with meta- and para-substitution on the aryl ring of ether hydroxamic acids 19c, 20c, 19e, 19f and 19g are potent HDAC inhibitors with activities at low nanomolar levels. Copyright © 2010 Elsevier Ltd. All rights reserved.

Silver nanoparticles added PVDF/ZnO nanocomposites: Synthesis and characterization

NASA Astrophysics Data System (ADS)

Singh, Utpal; Kumari, Niraj; Jha, Anal K.; Chandra, K. P.; Kolte, Jayant; Kulkarni, A. R.; Prasad, K.

2018-05-01

Silver and zinc oxide nanoparticles were prepared using citric acid method. The formations and crystal structures were ascertained from the X-ray diffraction data and the average crystallite size was estimated using Williamson-Hall approach. The hybrid combinations of Ag and ZnO nanoparticles were utilized to prepare PVDF/ZnO(90/10)-Ag nanocomposites (with Ag as filler: 0.5, 1 and 1.5%) using melt-mixing technique. Cole-Cole analysis suggested the dielectric relaxation in this system to be of non-Debye type. Also, addition of Ag nanoparticles enabled long-range conductivity in PVDF/ZnO nanocomposite.

Synthesis of Ce doped ZnO nanoparticles coupled with graphene oxide as efficient photocatalyst for the degradation of dye under day light

NASA Astrophysics Data System (ADS)

Labhane, P. K.; Patle, L. B.; Huse, V. R.; Sonawane, G. H.

2018-05-01

Ce doped ZnO nanoparticles coupled with graphene oxide (Ce-ZnO/GO) photocatalyst was prepared by co-precipitation and wet impregnation method. The effect of Ce doping on ZnO and ZnO-GO composite has been evaluated by using XRD, Williamson-Hall Plot, FESEM and EDX data. Solar light photocatalytic activities of samples were evaluated spectrophotometrically by the degradation of methylene blue (MB). Ce doped ZnO coupled with GO shows excellent catalytic efficiency compared to other samples, degrading MB completely within 120 min under day light.

The first total synthesis of sporiolide A.

PubMed

Du, Yuguo; Chen, Qi; Linhardt, Robert J

2006-10-27

The first total synthesis of the natural cytotoxic agent sporiolide A has been accomplished from D-glucal in 16 steps with 6.1% overall yield. Carbohydrates were applied as the chiral templates to manipulate the absolute configuration during the synthesis. Pyridinium chlorochromate (PCC)-promoted transformation of the cyclic enol-ether to lactone, followed by Yamaguchi esterification and intramolecular ring closure metathesis, greatly facilitates synthesis of the target compound.

Rhodium-Catalyzed Denitrogenative [3+2] Cycloaddition: Access to Functionalized Hydroindolones and the Framework of Montanine-Type Amaryllidaceae Alkaloids.

PubMed

Yang, Hongjian; Hou, Shengtai; Tao, Cheng; Liu, Zhao; Wang, Chao; Cheng, Bin; Li, Yun; Zhai, Hongbin

2017-09-18

Rhodium-catalyzed denitrogenative [3+2] cycloaddition of 1-sulfonyl-1,2,3-triazoles with cyclic silyl dienol ethers has been developed for the synthesis of functionalized hydroindolones or their corresponding silyl ethers. The present method has been employed to construct synthetically valuable bicyclo[3.3.1]alkenone derivatives and pyrrolidine-ring-containing bicyclic indole compounds. As a further synthetic application, a stereoselective synthesis of 5,11-methanomorphanthridin-3-one, which shares a key skeleton with montanine-type Amaryllidaceae alkaloids has been achieved by using this chemistry. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

James Williamson d/b/a Golden Triangle Builders Information Sheet

EPA Pesticide Factsheets

James Williamson d/b/a Golden Triangle Builders (the Company) is located in Pittsburgh, Pennsylvania. The settlement involves renovation activities conducted at property constructed prior to 1978, located in Pittsburgh, Pennsylvania.

Williamson Polishing & Plating Site

EPA Pesticide Factsheets

Williamson Polishing & Plating Co. Inc. was a plating shop located in the Martindale-Brightwood neighborhood of Indianapolis. The facility conducted job shop polishing and electroplating services. The vacant site contains a 14,651-square-foot building.

Novel Side-Chain Liquid Cyrstalline Polymers

DTIC Science & Technology

1989-01-01

Synthesis and Characterization of Liquid Crystalline Polyacrylates and Poly- methacrylates Containing Benzyl Ether and Diphenyl Ethane Based Mesogens J...Crystalline Polymethacrylates and Polyacrylates of trans 2-[4-(11- hydroxyundecanyloxy)-3,5-dimethylphenylI-4-(4-methoxyphenyl)-l,3-dioxane Makromol. Chem., 189...and Characterization of Liquid Crystalline Polyacrylates and Poly- met acrylates Containing Benzyl Ether and Diphenyl Ethane Based Mesogens J. Polym

The First Total Synthesis of Sporiolide A

PubMed Central

Chen, Qi; Linhardt, Robert J.

2014-01-01

The first total synthesis of the natural cytotoxic agent sporiolide A has been accomplished from D-glucal in 16 steps with 6.1% overall yield. Carbohydrates were applied as the chiral templates to manipulate the absolute configuration during the synthesis. Pyridinium chlorochromate (PCC)-promoted transformation of the cyclic enol-ether to lactone, followed by Yamaguchi esterification and intramolecular ring closure metathesis, greatly facilitates synthesis of the target compound. PMID:17064018

Ketimine modifications as a route to novel amorphous and derived semicrystalline poly(arylene ether ketone) homo- and copolymers

NASA Technical Reports Server (NTRS)

Mohanty, D. K.; Lowery, R. C.; Lyle, G. D.; Mcgrath, J. E.

1987-01-01

A series of amine terminal amorphous poly(arylene ether ketone) oligomers of controlled molecular weights (2-15 K) were synthesized. These oligomers have been found to undergo 'self-crosslinking' reactions upon heating above 220 C, via the reaction of the terminal amine groups with the in-chain keto carbonyl functionalities. The resulting networks are ductile, chemically resistant, and nonporous. The networks obtained via generated ketimine functionality were characterized by solid state NMR. They have also been found to be remarkably stable toward hydrolysis. Ketimine functional bishalide monomers have also been synthesized. Such monomers have been utilized to synthesize a wide variety of amorphous poly(arylene ether) ketimine polymers. A high molecular weight hydroquinone functional poly(arylene ether) ketimine has been acid treated to regenerate a poly(arylene ether ketone) backbone in solution. This novel procedure thus allows for the synthesis of important matrix resins under relatively mild conditions.

Synthesis and biological evaluation of arctigenin ester and ether derivatives as activators of AMPK.

PubMed

Shen, Sida; Zhuang, Jingjing; Chen, Yijia; Lei, Min; Chen, Jing; Shen, Xu; Hu, Lihong

2013-07-01

A series of new arctigenin and 9-deoxy-arctigenin derivatives bearing different ester and ether side chains at the phenolic hydroxyl positions are designed, synthesized, and evaluated for activating AMPK potency in L6 myoblasts. Initial biological evaluation indicates that some alkyl ester and phenethyl ether arctigenin derivatives display potential activities in AMPK phosphorylation improvement. Further structure-activity relationship analysis shows that arctigenin ester derivatives 3a, 3h and 9-deoxy-arctigenin phenethyl ether derivatives 6a, 6c, 6d activate AMPK more potently than arctigenin. Moreover, the 2-(3,4-dimethoxyphenyl)ethyl ether moiety of 6c has been demonstrated as a potential functional group to improve the effect of AMPK phosphorylation. The structural optimization of arctigenin leads to the identification of 6c as a promising lead compound that exhibits excellent activity in AMPK activation. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Learning Humanoid Arm Gestures

DTIC Science & Technology

2005-01-01

for a visual target with some accuracy ( Marjanovic , learning new gestures. Scassellati, and Williamson, 1996), this simple spring law system has some...coefficients of the reactions established in Marjanovic , M., Scassellati, B. and Williamson, M. 1996. meso. Other long-term metabolic changes could

Williamson-Hall analysis and optical properties of small sized ZnO nanocrystals

NASA Astrophysics Data System (ADS)

Kalita, Amarjyoti; Kalita, Manos P. C.

2017-08-01

We apply Williamson-Hall (WH) method of X-ray diffraction (XRD) line profile analysis for lattice strain estimation of small sized ZnO nanocrystals (crystallite size≈4 nm). The ZnO nanocrystals are synthesized by room temperature chemical co-precipitation followed by heating at 40 °C. Zinc acetate, sodium hydroxide and 2-mercaptoethanol (ME) are used for the synthesis of the nanocrystals. {100}, {002}, {101} and {200}, {112}, {201} line profiles in the XRD pattern are significantly merged, therefore determination of the full width at half maximum values and peak positions of the line profiles required for WH analysis has been carried out by executing Rietveld refinement of the XRD pattern. Lattice strain of the 4 nm sized ZnO nanocrystals is found to be 5.8×10-3 which is significantly higher as compared to the literature reported values for larger ones (crystallite size≈17-47 nm). Role of ME as capping agent is confirmed by Fourier transform infrared spectroscopy. The band gap of the nanocrystals is determined from the UV-Visible absorption spectrum and is found to be 3.68 eV. The photoluminescence spectrum exhibits emissions in the visible (408 nm-violet, 467 nm-blue and 538 nm-green) regions showing presence of zinc interstitial and oxygen vacancy in the ZnO nanocrystals.

A Short, One-Pot Synthesis of Bupropion (Zyban®, Wellbutrin®)

NASA Astrophysics Data System (ADS)

Perrine, Daniel M.; Ross, Jason T.; Nervi, Stephen J.; Zimmerman, Richard H.

2000-11-01

A one-pot synthesis of (±)-2-(t-butylamino)-3'-chloropropiophenone (bupropion) as its hydrochloride salt (Zyban, Wellbutrin), an important antidepressant drug used in the treatment of nicotine addiction, is described. The procedure, suitable for students in their first year of organic chemistry, can be carried out in less than two hours and provides material of high purity in overall yield of 75-85%. A solution of m-chloropropiophenone in CH2Cl2 is treated with Br2. After removal of the solvent, t-butylamine and N-methylpyrrolidinone are added and the mixture is warmed briefly, quenched with water, and extracted with ether. Concentrated HCl is added to the ether solution to precipitate the product.

Alexander Williamson and the modernisation of Japan.

PubMed

Davies, Alwyn G

2015-01-01

One hundred and fifty years ago, five students were smuggled out of feudal Japan and came to London to learn Western technology, governance, and economics. They were put into the care of Alexander Williamson, who was Professor of Chemistry at University College London, and when they went back they, and the students who followed them, became the founders of the modern Japanese state. This is the British side of that remarkable story. Williamson's career and chemistry are briefly reviewed, followed by an account of the students' presence in Britain, and then the commemoration of the sesquicentenary of these events.

Dispersal of larval suckers at the Williamson River Delta, Upper Klamath Lake, Oregon, 2006-09

USGS Publications Warehouse

Wood, Tamara M.; Hendrixson, Heather A.; Markle, Douglas F.; Erdman, Charles S.; Burdick, Summer M.; Ellsworth, Craig M.; Buccola, Norman L.

2012-01-01

An advection/diffusion modeling approach was used to simulate the transport of larval suckers from spawning areas in the Williamson River, through the newly restored Williamson River Delta, to Upper Klamath Lake. The density simulations spanned the years of phased restoration, from 2006/2007 prior to any levee breaching, to 2008 when the northern part of the delta was reconnected to the lake, and 2009 when levees on both sides of the delta had been breached. Model simulation results from all four years were compared to field data using rank correlation. Spearman ρ correlation coefficients were usually significant and in the range 0.30 to 0.60, providing moderately strong validation of the model. The correlation coefficients varied with fish size class in a way that suggested that the model best described the distribution of smaller fish near the Williamson River channel, and larger fish away from the channel. When Lost River and shortnose/Klamath largescale suckers were simulated independently, the correlation results suggested that the model better described the transport and dispersal of the latter species. The incorporation of night-time-only drift behavior in the Williamson River channel neither improved nor degraded correlations with field data. The model showed that advection by currents is an important factor in larval dispersal.

Ethers as Oxygen Donor and Carbon Source in Non-hydrolytic Sol-Gel: One-Pot, Atom-Economic Synthesis of Mesoporous TiO2 -Carbon Nanocomposites.

PubMed

Escamilla-Pérez, Angel Manuel; Louvain, Nicolas; Boury, Bruno; Brun, Nicolas; Mutin, P Hubert

2018-04-03

Mesoporous TiO 2 -carbon nanocomposites were synthesized using an original non-hydrolytic sol-gel (NHSG) route, based on the reaction of simple ethers (diisopropyl ether or tetrahydrofuran) with titanium tetrachloride. In this atom-economic, solvent-free process, the ether acts not only as an oxygen donor but also as the sole carbon source. Increasing the reaction temperature to 180 °C leads to the decomposition of the alkyl chloride by-product and to the formation of hydrocarbon polymers, which are converted to carbon by pyrolysis under argon. The carbon-TiO 2 nanocomposites and their TiO 2 counterparts (obtained by calcination) were characterized by nitrogen physisorption, XRD, solid state 13 C NMR and Raman spectroscopies, SEM, and TEM. The nanocomposites are mesoporous with surface areas of up to 75 m 2  g -1 and pore sizes around 10 nm. They are composed of aggregated anatase nanocrystals coated by an amorphous carbon film. Playing on the nature of the ether and on the reaction temperature allows control over the carbon content in the nanocomposites. The nature of the ether also influences the size of the TiO 2 crystallites and the morphology of the nanocomposite. To further characterize the carbon coating, the behavior of the carbon-TiO 2 nanocomposites and bare TiO 2 samples toward lithium insertion-deinsertion was investigated in half-cells. This simple NHSG approach should provide a general method for the synthesis of a wide range of carbon-metal oxide nanocomposites. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polycyclic Peptides: A New Type of Cavitand,

DTIC Science & Technology

PEPTIDES, MOLECULAR STRUCTURE, MOLECULES, SYNTHESIS, ETHERS, DEXTRINS , PROTEINS, AMINO ACIDS, RESIDUES, CROSSLINKING(CHEMISTRY), DIMERS, CESIUM, CARBON, OXYGEN, NITROGEN, CAVITIES, NUCLEAR MAGNETIC RESONANCE.

Discovery of Antibiotics-derived Polymers for Gene Delivery using Combinatorial Synthesis and Cheminformatics Modeling

PubMed Central

Potta, Thrimoorthy; Zhen, Zhuo; Grandhi, Taraka Sai Pavan; Christensen, Matthew D.; Ramos, James; Breneman, Curt M.; Rege, Kaushal

2014-01-01

We describe the combinatorial synthesis and cheminformatics modeling of aminoglycoside antibiotics-derived polymers for transgene delivery and expression. Fifty-six polymers were synthesized by polymerizing aminoglycosides with diglycidyl ether cross-linkers. Parallel screening resulted in identification of several lead polymers that resulted in high transgene expression levels in cells. The role of polymer physicochemical properties in determining efficacy of transgene expression was investigated using Quantitative Structure-Activity Relationship (QSAR) cheminformatics models based on Support Vector Regression (SVR) and ‘building block’ polymer structures. The QSAR model exhibited high predictive ability, and investigation of descriptors in the model, using molecular visualization and correlation plots, indicated that physicochemical attributes related to both, aminoglycosides and diglycidyl ethers facilitated transgene expression. This work synergistically combines combinatorial synthesis and parallel screening with cheminformatics-based QSAR models for discovery and physicochemical elucidation of effective antibiotics-derived polymers for transgene delivery in medicine and biotechnology. PMID:24331709

Discovery of Imidazo[1,2-a]pyridine Ethers and Squaramides as Selective and Potent Inhibitors of Mycobacterial Adenosine Triphosphate (ATP) Synthesis.

PubMed

Tantry, Subramanyam J; Markad, Shankar D; Shinde, Vikas; Bhat, Jyothi; Balakrishnan, Gayathri; Gupta, Amit K; Ambady, Anisha; Raichurkar, Anandkumar; Kedari, Chaitanyakumar; Sharma, Sreevalli; Mudugal, Naina V; Narayan, Ashwini; Naveen Kumar, C N; Nanduri, Robert; Bharath, Sowmya; Reddy, Jitendar; Panduga, Vijender; Prabhakar, K R; Kandaswamy, Karthikeyan; Saralaya, Ramanatha; Kaur, Parvinder; Dinesh, Neela; Guptha, Supreeth; Rich, Kirsty; Murray, David; Plant, Helen; Preston, Marian; Ashton, Helen; Plant, Darren; Walsh, Jarrod; Alcock, Peter; Naylor, Kathryn; Collier, Matthew; Whiteaker, James; McLaughlin, Robert E; Mallya, Meenakshi; Panda, Manoranjan; Rudrapatna, Suresh; Ramachandran, Vasanthi; Shandil, Radha; Sambandamurthy, Vasan K; Mdluli, Khisi; Cooper, Christopher B; Rubin, Harvey; Yano, Takahiro; Iyer, Pravin; Narayanan, Shridhar; Kavanagh, Stefan; Mukherjee, Kakoli; Balasubramanian, V; Hosagrahara, Vinayak P; Solapure, Suresh; Ravishankar, Sudha; Hameed P, Shahul

2017-02-23

The approval of bedaquiline to treat tuberculosis has validated adenosine triphosphate (ATP) synthase as an attractive target to kill Mycobacterium tuberculosis (Mtb). Herein, we report the discovery of two diverse lead series imidazo[1,2-a]pyridine ethers (IPE) and squaramides (SQA) as inhibitors of mycobacterial ATP synthesis. Through medicinal chemistry exploration, we established a robust structure-activity relationship of these two scaffolds, resulting in nanomolar potencies in an ATP synthesis inhibition assay. A biochemical deconvolution cascade suggested cytochrome c oxidase as the potential target of IPE class of molecules, whereas characterization of spontaneous resistant mutants of SQAs unambiguously identified ATP synthase as its molecular target. Absence of cross resistance against bedaquiline resistant mutants suggested a different binding site for SQAs on ATP synthase. Furthermore, SQAs were found to be noncytotoxic and demonstrated efficacy in a mouse model of tuberculosis infection.

An investigation into the effects of different existing states of aluminum isopropoxide on copper-based catalysts for direct synthesis of dimethyl ether from syngas

NASA Astrophysics Data System (ADS)

Sun, Kai; Wang, Peng; Bian, Zhongkai; Huang, Wei

2018-01-01

Aluminum isopropoxide (AIP) is a vital raw material to produce high surface area alumina catalyst, which is used for catalytic applications, such as hydrocracking, Fischer-Tropsch and STD (syngas to dimethyl ether) reactions. However, the different existing states have an effect on hydrolysis and condensation in the process of precursor preparation. The Cu/Zn/Al slurry catalysts were prepared by aluminum isopropoxide, which were liquid state, crystalline state and solid state, utilizing a complete liquid phase preparation technology. In the dimethyl ether (DME) synthesis reaction, the aluminum resource of crystalline state was prepared for slurry catalyst, which presented high CO conversion and DME selectivity of 54.32% and 69.74%, respectively. Characterization results indicated that different forms of AIP have the variant coordination numbers of Al-O and polymerization degrees, and the catalyst prepared by crystalline state consists amount of tetra-coordinated Al and few hexa-coordinated Al, which can exert different hydrolysis and condensation process compared with other aluminum sources, and finally it contributes to the strong interaction between active site copper species and Zn/Al species, confirming more Cu+ is responsible for the synthesis of DME in the slurry reactor.

Dictyostelium discoideum Dgat2 Can Substitute for the Essential Function of Dgat1 in Triglyceride Production but Not in Ether Lipid Synthesis

PubMed Central

Du, Xiaoli; Herrfurth, Cornelia; Gottlieb, Thomas; Kawelke, Steffen; Feussner, Kristin; Rühling, Harald; Feussner, Ivo

2014-01-01

Triacylglycerol (TAG), the common energy storage molecule, is formed from diacylglycerol and a coenzyme A-activated fatty acid by the action of an acyl coenzyme A:diacylglycerol acyltransferase (DGAT). In order to conduct this step, most organisms rely on more than one enzyme. The two main candidates in Dictyostelium discoideum are Dgat1 and Dgat2. We show, by creating single and double knockout mutants, that the endoplasmic reticulum (ER)-localized Dgat1 enzyme provides the predominant activity, whereas the lipid droplet constituent Dgat2 contributes less activity. This situation may be opposite from what is seen in mammalian cells. Dictyostelium Dgat2 is specialized for the synthesis of TAG, as is the mammalian enzyme. In contrast, mammalian DGAT1 is more promiscuous regarding its substrates, producing diacylglycerol, retinyl esters, and waxes in addition to TAG. The Dictyostelium Dgat1, however, produces TAG, wax esters, and, most interestingly, also neutral ether lipids, which represent a significant constituent of lipid droplets. Ether lipids had also been found in mammalian lipid droplets, but the role of DGAT1 in their synthesis was unknown. The ability to form TAG through either Dgat1 or Dgat2 activity is essential for Dictyostelium to grow on bacteria, its natural food substrate. PMID:24562909

Ion pair recognition by Zn-porphyrin/crown ether conjugates: visible sensing of sodium cyanide.

PubMed

Kim, Yeon-Hwan; Hong, Jong-In

2002-03-07

Synthesis and complexation behavior of ditopic neutral receptors composed of both a Lewis-acidic binding site (zinc porphyrin moiety) and a Lewis-basic binding site (crown ether moiety) are reported; the receptors bound only NaCN in a ditopic fashion with a color change, and in contrast other sodium salts bound to the receptors in a monotopic fashion without a color change.

Benzylamine-Free, Heavy-Metal-Free Synthesis of CL-20

DTIC Science & Technology

2006-12-28

well as its tetraacetate ester—was completely destroyed by concentrated hydrochloric acid .20 Even earlier, Reynolds et al. reported the general...acetals, can be driven by catalysis with Lewis acids , such as boron trifluoride etherate, instead of Brønsted acids . 22 Also, condensations between...using a Lewis acid , boron trifluoride etherate (Eq. 1), (1) and a Brønsted acid , deuterium chloride (Eq. 2), as catalysts failed to produce

Highly Stereoselective Gold-Catalyzed Coupling of Diazo Reagents and Fluorinated Enol Silyl Ethers to Tetrasubstituted Alkenes.

PubMed

Liao, Fu-Min; Cao, Zhong-Yan; Yu, Jin-Sheng; Zhou, Jian

2017-02-20

We report a highly stereoselective synthesis of all-carbon or fluorinated tetrasubstituted alkenes from diazo reagents and fluorinated enol silyl ethers, using C-F bond as a synthetic handle. Cationic Au I catalysis plays a key role in this reaction. Remarkable fluorine effects on the reactivity and selectivity was also observed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Challenges in Building Robots that Imitate People

DTIC Science & Technology

2000-01-01

pages 25 40, 1998. R. Brooks, C. Breazeal (Ferrell), R. Irie, C. Kemp, M. Marjanovic , B. Scassellati, & M. Williamson. Alternative essences of...Breazeal (Ferrell), M. Marjanovic , B. Scassellati, and M. Williamson. The Cog project: building a humanoid robot. In C. Nehaniv, editor, Computationjbr

Synthesis of Norbornane Bisether Antibiotics via Silver-mediated Alkylation

PubMed Central

Hickey, Shane M.; Ashton, Trent D.; White, Jonathan M.; Li, Jian; Nation, Roger L.; Yu, Heidi Y.; Elliott, Alysha G.; Butler, Mark S.; Huang, Johnny X.; Cooper, Matthew A.

2015-01-01

A small series of norbornane bisether diguanidines have been synthesized and evaluated as antibacterial agents. The key transformation—bisalkylation of norbornane diol 6—was not successful using Williamson methodology but has been accomplished using Ag2O mediated alkylation. Further functionalization to incorporate two guanidinium groups gave rise to a series of structurally rigid cationic amphiphiles; several of which (16d, 16g and 16h) exhibited antibiotic activity. For example, compound 16d was active against a broad range of bacteria including Pseudomonas aeruginosa (MIC = 8 µg/mL), Escherichia coli (MIC = 8 µg/mL) and methicillin-resistant Staphylococcus aureus (MIC = 8 µg/mL). PMID:26251697

Synthesis and characterization of rod like C doped ZnO nanoparticles with enhanced photocatalytic activities

NASA Astrophysics Data System (ADS)

Labhane, P. K.; Sapkal, B. M.; Sonawane, G. H.

2018-05-01

Carbon (C) doped ZnO rod like nanoparticles were prepared by simple co-precipitation method. The effect of C doping on ZnO has been evaluated by using XRD, Williamson-Hall Plot, FESEM and EDX data. UV light assisted photocatalytic activities of prepared samples were evaluated spectrophotometrically by the degradation of methylene blue (MB). C doped ZnO shows excellent catalytic efficiency compared to pure ZnO, degrading MB completely within 100 min under UV light. Photocatalysis follows the first order kinetics law and the calculated apparent reaction kinetics rate constant suggest the better activity of C-ZnO.

Synthesis and blood pressure lowering activity of benzylic ethers of 2-diethylaminoethanol and a related diamine.

PubMed

El-Antably, S M; Soine, T O; Shaath, N A; Gupta, P K

1975-08-01

Based upon the unpublished finding that 3'-hydroxy-4'-(beta-diethylaminoethoxy)-3',4'-dihydroseselin possessed a potent blood pressure lowering effect in the cat at a dose of 1 mg/kg, the present study examined the activities of several related compounds. These compounds were derived by dissection of the parent compound to give four benzylic ethers of 2-diethylaminoethanol and a diamine, derived by replacing the ether oxygen of the parent compound with an N--CH3 function. The simplest compounds were the benzyl and 2,6-dimethoxybenzyl ethers of the aminoalcohol. Closely related to the benzyl compound was a congener with a hydroxymethyl group on the benzylic carbon. The beta-diethylaminoethyl ether of 4-chromanol was the most complex of the ethers. The blood pressure measurements were carried out on male cats and compared to papaverine hydrochloride as a standard. In all cases, the most potent blood pressure lowering activity resided in the parent compound, which was not greatly superior to the diamine but substantially more active than the other compounds.

Regioselective and enantiospecific rhodium-catalyzed allylic alkylation reactions using copper(I) enolates: synthesis of (-)-sugiresinol dimethyl ether.

PubMed

Evans, P Andrew; Leahy, David K

2003-07-30

The transition metal-catalyzed allylic alkylation represents a fundamentally important cross-coupling reaction for the construction of ternary carbon stereogenic centers. We have developed a regioselective and enantiospecific rhodium-catalyzed allylic alkylation of acyclic unsymmetrical allylic alcohol derivatives using copper(I) enolates to prepare beta-substituted ketones. This protocol represents a convenient asymmetric Claisen rearrangement surrogate in which alpha-substituted enolates permit the introduction of an additional stereogenic center. The synthetic utility of this transformation was highlighted in the construction of a trans-1,2-disubstituted cyclohexene and the total synthesis of (-)-sugiresinol dimethyl ether. Finally, we anticipate that copper(I) enolates may prove useful nucleophiles in related metal-catalyzed reactions.

Synthesis of Perfluorinated Ethers by Solution Phase Direct Fluorination: An Adaptation of the La-Mar Technique

DTIC Science & Technology

1990-08-22

Six of the 3 perfluorinated ethers prepared have been previously synthesized by other methods: perfluoro -5,5-bis(ethoxy- f methyl) -3,7-dioxanonane...from partially fluorinated starting material [34]. Third, as with perfluoroalkanes and simple perfluoroethers , Clark’s experimental results indicated 3...a highly branched perfluoroether ) by direct fluorination 3 in solution. Second, since some of these perfluorinated compounds had been previously

Finding the Kool Mixx: how Brown & Williamson used music marketing to sell cigarettes.

PubMed

Hafez, Navid; Ling, Pamela M

2006-10-01

To describe the history of Kool's music-themed promotions and analyse the role that music played in the promotion of the brand. Analysis of previously secret tobacco industry documents, legal documents, and promotional materials. Brown & Williamson started Kool sponsorship of musical events in 1975 with Kool Jazz concerts. Music was considered to be an effective marketing tool because: (1) music helped consumers make emotional connections with the brand; (2) music concerts were effective for targeted marketing; (3) music tied together an integrated marketing campaign; and (4) music had potential to appeal widely to a young audience. Brown & Williamson's first music campaigns successfully targeted young African-American male audiences. Subsequent campaigns were less effective, exploring different types of music to achieve a broader young adult appeal. This case study suggests Brown & Williamson used music most successfully for targeted marketing, but they failed to develop a wider audience using music because their attempts lacked consistency with the Kool brand's established identity. The 2004 "Kool Mixx" campaign both returned to Brown & Williamson's historic practice targeting young African-American males, and also exploited a musical genre with much more potential to bring Kool more universal appeal, as hip-hop music is increasingly popular among diverse audiences. Tobacco control efforts led by African-American community activists to oppose these marketing strategies should continue; expanding these coalitions to include the hip-hop community may further increase their effectiveness.

Hydrogeologic framework and potentiometric surface of the Williamson Creek Aquifer "B" sand in the Fort Polk area, Vernon Parish, Louisiana, March 1997

USGS Publications Warehouse

Prakken, Lawrence B.

2001-01-01

The Fort Polk Military Reservation(hereinafter referred to as the Reservation) in Vernon Parish, Louisiana, occupies 107,024 acres of lands; 66,998 acres are owned by the U.S. Army, and 40,026 acres are owned by the U.S. Forest Service (Dan Nance, Fort Polk Public Affairs office, written commun., 1998).  Some areas of the Reservation, such as an artillery impact area, live-firm areas, and special purpose training areas, are restricted to military personnel.  The Williamson Creek and Carnahan Bayou aquifers are major sources of freshwater for the Reservation.  IN 1996, the Reservation's total water pumpage from the Williamson Creek aquifer for public supply was approxiamately 2.4 million gallons per day (Edward Ducote, Water and Wastewater Branch, Directorate of Public Works, Fort Polk, written commun., 1998).  In 1997, the water withdrawl rate for public supply was approzimately 1.88 million gallons per day from 11 wells completed in the Williamson Creek aquifer.  Almost all of the water was withdrawn from the "B" sand, which is the predominant sand layer of the Williamson Creek aquifer in the study area.  In 1997, nearby Leesville, the seat of Vernon Parish, withdrew all its water for public supply from the deeper Carnahan Bayou aquifer.

Synthesis and biological studies of positron-emitting radiopharmaceuticals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dischino, D.D.

The development and clinical evaluation of two-positron emitting radiopharmaceuticals designed to image myelin in humans is reported. Carbon-11-labeled benzyl methyl ether was synthesized by the reaction of carbon-11-labeled methanol and benzyl chloride in dimethyl sulfoxide containing powdered potassium hydroxide in a radiochemical yield of 43% and a synthesis and purification time of 40 minutes. Carbon-11-labeled diphenylmethanol was synthesized by the reaction of carbon-11-labeled carbon dioxide and phenyllithium followed by the reduction of the carbon-11-labeled intermediate to diphenylmethanol via lithium aluminum hydride in a radiochemical yield of 71% and a synthesis and purification time of 38 minutes. Carbon-11-labeled benzyl methyl ethermore » and diphenylmethanol were each evaluated as myelin imaging agents in three patients with multiple sclerosis via positron-emission tomography. In two out of three patients studied with carbon-11-labeled benzyl methyl ether, the distribution of activity in the brain was not consistent with local lipid content. A new synthesis of carbon-11-labeled-DL-phenylalanine labeled in the benzylic position and the synthesis of fluorine-18-labeled 1-(2-nitro-1-imidazolyl)-3-fluoro-2-propanol, a potential in vivo marker of hypoxic tissue, are reported.« less

Synthesis and electronic factors in thermal cyclodimerization of functionalized aromatic trifluorovinyl ethers.

PubMed

Spraul, Bryan K; Suresh, S; Jin, Jianyong; Smith, Dennis W

2006-05-31

A series of 19 p-substituted aromatic trifluorovinyl ether compounds were prepared from versatile intermediate p-Br-C(6)H(4)-O-CF=CF(2) and underwent thermal radical mediated cyclodimerization to new difunctional compounds containing the 1,2-disubstituted perfluorocyclobutyl (PFCB) linkage. The synthetic scope demonstrates the functional group transformation tolerance of the fluorovinyl ether, and the dimers are useful as monomers for traditional step-growth polymerization methods. (19)F NMR spectra confirmed that p-substitution affects the trifluorovinyl ether group chemical shifts. The first kinetic studies and substituent effects on thermal cyclodimerization were performed, and the results indicated that electron-withdrawing groups slow the rate of cyclodimerization. The data were further analyzed using the Hammett equation, and reaction constants (rho) of -0.46 at 120 degrees C and -0.59 at 130 degrees C were calculated. This study presents the first liner free energy relationship reported for the cyclodimerization of aromatic trifluorovinyl ethers to PFCB compounds.

Synthesis and amphiphilic properties of decanoyl esters of tri- and tetraethylene glycol.

PubMed

Zhu, Ying; Molinier, Valérie; Queste, Sébastien; Aubry, Jean-Marie

2007-08-15

Well-defined decanoyl triethylene glycol ester and decanoyl tetraethylene glycol ester were synthesized and compared to their ether counterparts (C(10)E(4) and C(10)E(3)). Their physicochemical properties i.e. critical micelle concentrations (CMC), cloud points, and equilibrium surface tensions were determined. Binary water-surfactant phase behavior was also studied by polarized optical microscopy. The stability of the ester bond was determined by investigating alkaline hydrolysis of the compounds. It was found that CMC, cloud point and equilibrium surface tension are roughly the same for corresponding ethers and esters. In the binary diagram, the esters form only lamellar phases, the area of which is smaller than that of the ether counterparts. These different behaviors can be related to the modification of the molecular conformation induced by the replacement of the ether group by the ester group.

Synthesis and characterization of sulfonated poly ether ether ketone (sPEEK) membranes for low temperature fuel cells

NASA Astrophysics Data System (ADS)

Ali, Mawlood Maajal; Rizvi, S. J. A.; Azam, Ameer

2018-05-01

Poly ether ether ketone (PEEK) was sulfonated with 1.0 M sulphuric acid for varying durations to have various degrees of sulfonation (DS) from 43 to 55%. The FT-IR spectra confirmed the successful sulfonation of PEEK. The sulfonated PEEK (sPEEK) membranes were prepared by a solvent casting method using dimethylacetamide (DMAc) as solvent and upon drying the membranes were characterized. The DS% and ion exchange capacity (IEC) were determined by a back titration method. The IEC and DS of sPEEK was found to increase with the increment of sulfonation reaction time. Water uptake also increased with increase in the DS. The Thermogravimetric (TGA) curves revealed poor thermal stability of sPEEK. The proton conductivity of sPEEK membrane was found to considerably better with degree of sulfonation for fuel cell application.

Production of Biomass-Based Automotive Lubricants by Reductive Etherification.

PubMed

Jadhav, Deepak; Grippo, Adam M; Shylesh, Sankaranarayanapillai; Gokhale, Amit A; Redshaw, John; Bell, Alexis T

2017-06-09

Growing concern with the effects of CO 2 emissions due to the combustion of petroleum-based transportation fuels has motivated the search for means to increase engine efficiency. The discovery of ethers with low viscosity presents an important opportunity to improve engine efficiency and fuel economy. We show here a strategy for the catalytic synthesis of such ethers by reductive etherification/O-alkylation of alcohols using building blocks that can be sourced from biomass. We find that long-chain branched ethers have several properties that make them superior lubricants to the mineral oil and synthetic base oils used today. These ethers provide a class of potentially renewable alternatives to conventional lubricants produced from petroleum and may contribute to the reduction of greenhouse gases associated with vehicle emissions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluating external nutrient and suspended-sediment loads to Upper Klamath Lake, Oregon, using surrogate regressions with real-time turbidity and acoustic backscatter data

USGS Publications Warehouse

Schenk, Liam N.; Anderson, Chauncey W.; Diaz, Paul; Stewart, Marc A.

2016-12-22

Executive SummarySuspended-sediment and total phosphorus loads were computed for two sites in the Upper Klamath Basin on the Wood and Williamson Rivers, the two main tributaries to Upper Klamath Lake. High temporal resolution turbidity and acoustic backscatter data were used to develop surrogate regression models to compute instantaneous concentrations and loads on these rivers. Regression models for the Williamson River site showed strong correlations of turbidity with total phosphorus and suspended-sediment concentrations (adjusted coefficients of determination [Adj R2]=0.73 and 0.95, respectively). Regression models for the Wood River site had relatively poor, although statistically significant, relations of turbidity with total phosphorus, and turbidity and acoustic backscatter with suspended sediment concentration, with high prediction uncertainty. Total phosphorus loads for the partial 2014 water year (excluding October and November 2013) were 39 and 28 metric tons for the Williamson and Wood Rivers, respectively. These values are within the low range of phosphorus loads computed for these rivers from prior studies using water-quality data collected by the Klamath Tribes. The 2014 partial year total phosphorus loads on the Williamson and Wood Rivers are assumed to be biased low because of the absence of data from the first 2 months of water year 2014, and the drought conditions that were prevalent during that water year. Therefore, total phosphorus and suspended-sediment loads in this report should be considered as representative of a low-water year for the two study sites. Comparing loads from the Williamson and Wood River monitoring sites for November 2013–September 2014 shows that the Williamson and Sprague Rivers combined, as measured at the Williamson River site, contributed substantially more suspended sediment to Upper Klamath Lake than the Wood River, with 4,360 and 1,450 metric tons measured, respectively.Surrogate techniques have proven useful at the two study sites, particularly in using turbidity to compute suspended-sediment concentrations in the Williamson River. This proof-of-concept effort for computing total phosphorus concentrations using turbidity at the Williamson and Wood River sites also has shown that with additional samples over a wide range of flow regimes, high-temporal-resolution total phosphorus loads can be estimated on a daily, monthly, and annual basis, along with uncertainties for total phosphorus and suspended-sediment concentrations computed using regression models. Sediment-corrected backscatter at the Wood River has potential for estimating suspended-sediment loads from the Wood River Valley as well, with additional analysis of the variable streamflow measured at that site. Suspended-sediment and total phosphorus loads with a high level of temporal resolution will be useful to water managers, restoration practitioners, and scientists in the Upper Klamath Basin working toward the common goal of decreasing nutrient and sediment loads in Upper Klamath Lake.

Caffeine-catalyzed gels.

PubMed

DiCiccio, Angela M; Lee, Young-Ah Lucy; Glettig, Dean L; Walton, Elizabeth S E; de la Serna, Eva L; Montgomery, Veronica A; Grant, Tyler M; Langer, Robert; Traverso, Giovanni

2018-07-01

Covalently cross-linked gels are utilized in a broad range of biomedical applications though their synthesis often compromises easy implementation. Cross-linking reactions commonly utilize catalysts or conditions that can damage biologics and sensitive compounds, producing materials that require extensive post processing to achieve acceptable biocompatibility. As an alternative, we report a batch synthesis platform to produce covalently cross-linked materials appropriate for direct biomedical application enabled by green chemistry and commonly available food grade ingredients. Using caffeine, a mild base, to catalyze anhydrous carboxylate ring-opening of diglycidyl-ether functionalized monomers with citric acid as a tri-functional crosslinking agent we introduce a novel poly(ester-ether) gel synthesis platform. We demonstrate that biocompatible Caffeine Catalyzed Gels (CCGs) exhibit dynamic physical, chemical, and mechanical properties, which can be tailored in shape, surface texture, solvent response, cargo release, shear and tensile strength, among other potential attributes. The demonstrated versatility, low cost and facile synthesis of these CCGs renders them appropriate for a broad range of customized engineering applications including drug delivery constructs, tissue engineering scaffolds, and medical devices. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Synthesis and characterization of water-soluble hydroxybutenyl cyclomaltooligosaccharides (cyclodextrins).

PubMed

Buchanan, Charles M; Alderson, Susan R; Cleven, Curtis D; Dixon, Daniel W; Ivanyi, Robert; Lambert, Juanelle L; Lowman, Douglas W; Offerman, Rick J; Szejtli, Jozsef; Szente, Lajos

2002-03-15

We have examined the synthesis of hydroxybutenyl cyclomaltooligosaccharides (cyclodextrins) and the ability of these cyclodextrin ethers to form guest-host complexes with guest molecules. The hydroxybutenyl cyclodextrin ethers were prepared by a base-catalyzed reaction of 3,4-epoxy-1-butene with the parent cyclodextrins in an aqueous medium. Reaction byproducts were removed by nanofiltration before the hydroxybutenyl cyclodextrins were isolated by co-evaporation of water-EtOH. Hydroxybutenyl cyclodextrins containing no unsubstituted parent cyclodextrin typically have a degree of substitution of 2-4 and a molar substitution of 4-7. These hydroxybutenyl cyclodextrins are randomly substituted, amorphous solids. The hydroxybutenyl cyclodextrin ethers were found to be highly water soluble. Complexes of HBen-beta-CD with glibenclamide and ibuprofen were prepared and isolated. In both cases, the guest content of the complexes was large, and a significant increase in the solubility of the free drug was observed. Dissolution of the complexes in pH 1.4 water was very rapid, and significant increases in the solubility of the free drugs were observed. Significantly, after reaching equilibrium concentration, a decrease in the drug concentration over time was not observed.

The Design, Synthesis and Screening of Potential Pyridinium Oxime Prodrugs.

DTIC Science & Technology

1985-07-31

copper sulfate pentahydrate , and 15 g (87 mol) of the mixture of bromo- picolines 13c and 131. The combined reactions produced 27 g (96%) of a brown...extracted with ethyl ether. The ether extracts were washed with brine, dried with sodium sulfate , filtered and flashed. The residue was then purified by...stirring to the reaction mix. The addition was exothermic as the copper complexes decomposed. The cooled mixture was extracted with several 20 ml

Synthesis and evaluation of C-ether formulations for use as high temperature lubricants and hydraulic fluids

NASA Technical Reports Server (NTRS)

Clark, F. S.; Green, R. L.; Miller, D. R.

1974-01-01

The formulation and evaluation of C-ether fluids for use in the hydraulic and lubrication systems of the space shuttle and advanced air breathing engines were studied to lower the pour point of a reference C-ether from -29 C to -40 C without changing its evaporation loss. Use of disiloxanes mixed with C-ethers gave a -40 C pour point fluid with little change in the desired evaporation loss or in oxidative stability. A second -40 C pour point fluid containing only C-ethers was also developed. A screening program tested lubrication additives for C-ethers and the new fluids. Six additive packages were chosen for evaluation in 316 C bearing tests, two for evaluation in 260 C pump tests. The goal of the bearing test was a 100 hour run. The rig was a specially designed 80-mm axially loaded ball bearing. The C-ether base fluid ran only one hour at 316 C before cage wear failure occurred. The best additive blends ran 47, 94 and 100 hours. The 96 hour test gave excessive deposits. The 100 hour test had no wear failures; an unexplained loss of cage silver occurred from areas of direct fluid impingement on the cage.

Marketing of patent medicines in the nineteenth century via a corkscrew medicine spoon.

PubMed

Fincham, Jack E

2010-01-01

The C. T. Williamson spoon with manufactured products from a pharmaceutical company engraved on the bowl of the spoon is one of the earliest examples of a manufacturer marketing products via a drug delivery device. The Burroughs, Wellcome and Company, a British corporation using initially an American patented, and later a British patented, Williamson corkscrew spoon marketed British manufactured medicinal products in the U.S. and England to physicians and pharmacists in the late nineteenth and early twentieth century. Other corkscrew spoons were manufactured in this era without product specific notations contained on the spoons. 40 These corkscrew spoons, such as the Williamson and Noe patented apparatuses, helped patients in more easily consuming liquid medications. They also were items potentially favored by physicians and pharmacists for patient's pro- vided liquid medications. Finally, they allowed patients to open corked containers, consume liquid dosage amounts, and hopefully more appropriately comply with necessary regimens in the late nineteenth and early twentieth century. Not surprisingly, Burroughs, Wellcome and Company used the Williamson spoon to successfully market company products to physicians, pharmacists, and patients on several continents.

Synthesis and Characterization of New Phosphazene Polymers.

DTIC Science & Technology

1988-01-21

reaction of a poly( alkyl /arylphosphazene). In this study, one-half of the methyl groups in [Ph(Me)PN]n (chosen for its solubility in THF as opposed to...polymerization reaction ; and (5) the derivative chemistry of the preformed poly( alkyl /arylphosphazenes)., Synthesis of Poly( alkyl /arylphosphazenes) SC A... vessels , these phosphoranimines quantitatively eliminate the silyl ether byproduct, Me3SiOCH2CF 3 , to form the poly( alkyl /arylphosphazenes). The synthesis

Enzymatic network for production of ether amines from alcohols.

PubMed

Palacio, Cyntia M; Crismaru, Ciprian G; Bartsch, Sebastian; Navickas, Vaidotas; Ditrich, Klaus; Breuer, Michael; Abu, Rohana; Woodley, John M; Baldenius, Kai; Wu, Bian; Janssen, Dick B

2016-09-01

We constructed an enzymatic network composed of three different enzymes for the synthesis of valuable ether amines. The enzymatic reactions are interconnected to catalyze the oxidation and subsequent transamination of the substrate and to provide cofactor recycling. This allows production of the desired ether amines from the corresponding ether alcohols with inorganic ammonium as the only additional substrate. To examine conversion, individual and overall reaction equilibria were established. Using these data, it was found that the experimentally observed conversions of up to 60% observed for reactions containing 10 mM alcohol and up to 280 mM ammonia corresponded well to predicted conversions. The results indicate that efficient amination can be driven by high concentrations of ammonia and may require improving enzyme robustness for scale-up. Biotechnol. Bioeng. 2016;113: 1853-1861. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Finding the Kool Mixx: how Brown & Williamson used music marketing to sell cigarettes

PubMed Central

Hafez, Navid; Ling, Pamela M

2006-01-01

Objective To describe the history of Kool's music‐themed promotions and analyse the role that music played in the promotion of the brand. Methods Analysis of previously secret tobacco industry documents, legal documents, and promotional materials. Results Brown & Williamson started Kool sponsorship of musical events in 1975 with Kool Jazz concerts. Music was considered to be an effective marketing tool because: (1) music helped consumers make emotional connections with the brand; (2) music concerts were effective for targeted marketing; (3) music tied together an integrated marketing campaign; and (4) music had potential to appeal widely to a young audience. Brown & Williamson's first music campaigns successfully targeted young African‐American male audiences. Subsequent campaigns were less effective, exploring different types of music to achieve a broader young adult appeal. Conclusions This case study suggests Brown & Williamson used music most successfully for targeted marketing, but they failed to develop a wider audience using music because their attempts lacked consistency with the Kool brand's established identity. The 2004 “Kool Mixx” campaign both returned to Brown & Williamson's historic practice targeting young African‐American males, and also exploited a musical genre with much more potential to bring Kool more universal appeal, as hip‐hop music is increasingly popular among diverse audiences. Tobacco control efforts led by African‐American community activists to oppose these marketing strategies should continue; expanding these coalitions to include the hip‐hop community may further increase their effectiveness. PMID:16998169

Synthesis of Quaternary Ammonium Salts of Tricyclic Cationic Drugs: A One-Pot Synthesis for the Bioorganic Chemistry Laboratory

ERIC Educational Resources Information Center

Brunauer, Linda S.; Mogannam, Abid C.; Hwee, Won B.; Chen, James Y.

2007-01-01

A one-pot conversion of tricyclic cationic drugs to their quaternary ammonium forms is described for a widely used bioactive drug: chlorpromazine, a phenothiazine-based antipsychotic. After conversion to its free base, the parent drug was methylated using substoichiometric amounts of methyl iodide dissolved in ether; the charged quaternary…

Nazarov cyclization initiated by peracid oxidation: the total synthesis of (+/-)-rocaglamide.

PubMed

Malona, John A; Cariou, Kevin; Frontier, Alison J

2009-06-10

The total syntheses of aglafolin, rocagloic acid, and rocaglamide using Nazarov cyclization are described. Generation of the necessary oxyallyl cation intermediate was accomplished via peracid oxidation of an allenol ether to generate an unusual oxycarbenium ion species that undergoes cyclization. The synthesis is efficient, highly diastereoselective, and strategically distinct from previous syntheses of rocaglamide.

Controlled synthesis of silver nanostructures stabilized by fluorescent polyarylene ether nitrile

NASA Astrophysics Data System (ADS)

Jia, Kun; Shou, Hongguo; Wang, Pan; Zhou, Xuefei; Liu, Xiaobo

2016-07-01

In this work, the intrinsically fluorescent polyarylene ether nitrile (PEN) was explored to realize the controlled synthesis of fluorescent silver nanostructures with different morphology for the first time. Specifically, it was found that silver nitrate (AgNO3) can be effectively reduced to silver nanoparticles using PEN as both reducing and surface capping agents in N, N-dimethylformamide (DMF). More interestingly, the morphology of obtained fluorescent silver nanostructures can be tuned from nanospheres to nanorods by simple variation of reaction time at 130 °C using a relative PEN:AgNO3 molar concentration ratio of 1:8. Meanwhile, the obtained Ag nanostructures exhibited both localized surface plasmon resonance (LSPR) band and fluorescent emission around 420 nm, which would find potential applications in biochemical sensing and optical devices fields.

Tandem Carbocupration/Oxygenation of Terminal Alkynes

PubMed Central

Zhang, Donghui; Ready, Joseph M.

2008-01-01

A direct and general synthesis of α-branched aldehydes and their enol derivatives is described. Carbocupration of terminal alkynes and subsequent oxygenation with lithium tert-butyl peroxide generates a metallo-enolate. Trapping with various electrophiles provides α-branched aldehydes or stereo-defined trisubstituted enol esters or silyl ethers. The tandem carbocupration/oxygenation tolerates alkyl and silyl ethers, esters and tertiary amines. The reaction is effective with organocopper complexes derived from primary, secondary and tertiary Grignard reagents and from n-butyllithium. PMID:16321021

Radiation-resistant, amorphous, all-aromatic poly(arylene ether sulfones) - Synthesis, physical behavior, and degradation characteristics

NASA Technical Reports Server (NTRS)

Lewis, D. A.; O'Donnell, James H.; Hedrick, J. L.; Ward, T. C.; Mcgrath, J. E.

1989-01-01

The effects of Co-60 gamma radiation on a series of poly(arylene ether sulfones) prepared by nucleophilic activated aromatic substitution are investigated experimentally. The preparation of the test compounds is described, and the test results are presented in extensive tables and graphs. Radiation-induced degradation, as measured by SO2 production, was found to be lowest in compounds based on biphenol rather than bisphenol A; these findings were also well correlated with ultimate-tensile-strain measurements.

Degradable Networks Containing Silyl Ether Bonds

NASA Astrophysics Data System (ADS)

Bassampour, Zahra S.

Degradable networks possess applications in many fields such as medical implants, electrical devices, industrial coatings, adhesives, and aerospace. Silyl ether bonds are reactive functionalities capable of degrading under physiological condition without significantly affecting the pH of the surrounding environment. This dissertation focuses on preparative methods of degradable networks utilizing silyl ether functionalities. Epoxy polymers are broadly utilized in many different applications. Despite the broad utilization of epoxy polymer thermosets in long-term applications, these thermosets are not very popular candidates in short-term applications. This unpopularity is mostly due to the fact that epoxy networks are non-degradable systems, which results in their recycling being very costly and environmentally unfriendly. In the first and second part of this dissertation, the synthesis of various amine and thiol curing agents containing hydrolyzable silyl ether bonds is described. Using these curing agents, thermosetting epoxy polymers with degradable properties were prepared. The degradation behavior and thermal properties of the cured networks were studied. Age-related macular degeneration (AMD) is a leading cause of vision loss in the industrialized world. The high prevalence of AMD and the complications and shortcomings of available treatment options give rise to a great need for the development of novel types of biodegradable implants to provide sustainable drug release. The third part of this dissertation describes the utilization of hydrolyzable silyl ether bonds in the synthesis of novel implants capable of reserving and releasing a drug in a controlled manner in order to treat AMD. Base- catalyzed thiol-Michael reactions were exploited to prepare a series of biodegradable cross- linked networks. The networks were characterized by FTIR, TGA, and DMA. The effect of monomer structure on degradation, release behavior, and thermal properties was investigated.

Suitability of Agent Technology for Military Command and Control in the Future Combat System Environment

DTIC Science & Technology

2003-06-01

and Multi-Agent Systems 1 no. 1 (1998): 7-38. [23] K. Sycara, A. Pannu , M. Williamson, and D. Zeng, “Distributed Intelligent Agents,” IEEE Expert 11...services that include support for mobility, security, management, persistence, and naming of agents. [i] K. Sycara, A. Pannu , M. Williamson, and D

Co-processing as a tool to improve aqueous dispersibility of cellulose ethers.

PubMed

Sharma, Payal; Modi, Sameer R; Bansal, Arvind K

2015-01-01

Cellulose ethers are important materials with numerous applications in pharmaceutical industry. They are widely employed as stabilizers and viscosity enhancers for dispersed systems, binders in granulation process and as film formers for tablets. These polymers, however, exhibit challenge during preparation of their aqueous dispersions. Rapid hydration of their surfaces causes formation of a gel that prevents water from reaching the inner core of the particle. Moreover, the surfaces of these particles become sticky, thus leading to agglomeration, eventually reducing their dispersion kinetics. Numerous procedures have been tested to improve dispersibility of cellulose ethers. These include the use of cross-linking agents, alteration in the synthesis process, adjustment of water content of cellulose ether, modification by attaching hydrophobic substituents and co-processing using various excipients. Among these, co-processing has provided the most encouraging results. This review focuses on the molecular mechanisms responsible for the poor dispersibility of cellulose ethers and the role of co-processing technologies in overcoming the challenge. An attempt has been made to highlight various co-processing techniques and specific role of excipients used for co-processing.

Chemical conversion of corticosteroids to 3 alpha,5 alpha-tetrahydro derivatives. Synthesis of 5 alpha-cortol 3-glucuronides and 5 alpha-cortolone 3-glucuronides.

PubMed

Hosoda, H; Osanai, K; Nambara, T

1991-12-01

The synthesis of the 3-glucuronides of 5 alpha-cortol-20 alpha, 5 alpha-cortolone-20 alpha and their 20 beta-epimers is described. The 5 alpha-cortol 20,21-diacetates (12, 17) and 5 alpha-cortolone 20,21-diacetates (14, 19) were the key intermediates. Sodium borohydride reduction of the carbonyl group at C-20 in 5 alpha-tetrahydrocortisol 3-tert-butyldimethylsilyl ether 17,21-acetonide (8) gave the 20 alpha-hydroxy-acetonide (9). Selective removal of the acetonide ring was successful when the 20 alpha-acetoxy-17 alpha,21-acetonide (10) was treated with 50% acetic acid. Subsequent acetylation with acetic anhydride in pyridine, followed by removal of the protecting group at C-3 in the silyl ether-acetate (11) gave the desired 20 alpha-intermediate (12). The 11-ketone (14) was prepared from 11 by oxidation with pyridinium chlorochromate, followed by desilylation. The 20 beta-acetates (17, 19) were synthesized from 21-acetoxy-3 alpha,11 beta,17 alpha-trihydroxy-5 alpha-pregnan-20-one 3-tert-butyldimethylsilyl ether (15). Introduction of the glucuronyl residue at C-3 was carried out by means of the Koenigs-Knorr reaction.

75 FR 67406 - Exelon Nuclear Texas Holdings, LLC; Victoria County Station Early Site Permit Application; Notice...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-02

... on the scope of the EIS by contacting Ms. Tomeka L. Terry or Ms. Alicia Williamson by telephone at 1... from Ms. Tomeka L. Terry or Ms. Alicia Williamson at U.S. Nuclear Regulatory Commission, Mailstop T... via e-mail at [email protected] or Alicia[email protected] . Dated at Rockville, Maryland, this...

75 FR 8994 - Certification of the Attorney General; Williamson County, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-26

... DEPARTMENT OF JUSTICE Certification of the Attorney General; Williamson County, TX In accordance with Section 8 of the Voting Rights Act, 42 U.S.C. 1973f, I hereby certify that in my judgment the... Section 4(b) of the Voting Rights Act, 42 U.S.C. 1973b(b), and published in the Federal Register on...

The Russo-Williamson Theses in the social sciences: causal inference drawing on two types of evidence.

PubMed

Claveau, François

2012-12-01

This article examines two theses formulated by Russo and Williamson (2007) in their study of causal inference in the health sciences. The two theses are assessed against evidence from a specific case in the social sciences, i.e., research on the institutional determinants of the aggregate unemployment rate. The first Russo-Williamson Thesis is that a causal claim can only be established when it is jointly supported by difference-making and mechanistic evidence. This thesis is shown not to hold. While researchers in my case study draw extensively on both types of evidence, one causal claim out of the three analyzed is established even though it is exclusively supported by mechanistic evidence. The second Russo-Williamson Thesis is that standard accounts of causality fail to handle the dualist epistemology highlighted in the first Thesis. I argue that a counterfactual-manipulationist account of causality--which is endorsed by many philosophers as well as many social scientists--can perfectly make sense of the typical strategy in my case study to draw on both difference-making and mechanistic evidence; it is just an instance of the common strategy of increasing evidential variety. Copyright © 2012 Elsevier Ltd. All rights reserved.

Brominated dioxins/furans and hydroxylated polybrominated diphenyl ethers: Occurrences in commercial 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and 2,4,6-tribromophenol, and formation during synthesis of BTBPE.

PubMed

Ren, Man; Zeng, Hao; Peng, Ping-An; Li, Hui-Ru; Tang, Cai-Ming; Hu, Jian-Fang

2017-07-01

Polybrominated dibenzo-p-dioxins (PBDDs) and hydroxylated polybrominated diphenyl ethers (OH-PBDEs) can be formed from bromophenols (BPs) by thermal degradation, biosynthesis or phototransformation. However, it is unknown whether PBDDs and OH-PBDEs can be formed during the chemical production processes that utilize BPs as raw materials. 2,4,6-tribromophenol (2,4,6-TBP) is an important raw material for the synthesis of 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), a novel brominated flame retardant. In this study, PBDDs, polybrominated dibenzofurans (PBDFs) and OH-PBDEs have been identified and quantified in commercially available BTBPE and 2,4,6-TBP. Furthermore, their formation as unintentional by-products during the laboratory synthesis of BTBPE from 2,4,6-TBP and 1,2-dibromoethane in the presence of sodium carbonate has also been investigated. 2,3,7,8-substituted PBDDs and PBDFs (2,3,7,8-PBDD/Fs) were undetectable in commercial samples of BTBPE and present in low levels (nanogram per gram) in 2,4,6-TBP. Two tetrabrominated dibenzo-p-dioxins (TeBDDs), namely 1,3,6,8- and 1,3,7,9-TeBDD, and three hydroxylated pentabrominated diphenyl ethers (OH-pentaBDEs), namely 4'-OH-BDE121, 2'-OH-BDE121, and 6'-OH-BDE100, were identified or tentatively identified, and quantitatively estimated to be at concentrations in the range of undetectable to several thousands of nanograms per gram in commercial BTBPE and 2,4,6-TBP. TeBDDs and OH-pentaBDEs were formed as by-products from 2,4,6-TBP during BTBPE synthesis. Further studies need to be conducted in order to determine whether PBDD/Fs and OH-PBDEs are also formed during the industrial synthesis of other chemical compounds that utilize BPs as raw materials or intermediates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrochemistry for biofuel generation: transformation of fatty acids and triglycerides to diesel-like olefin/ether mixtures and olefins.

PubMed

dos Santos, Tatiane R; Harnisch, Falk; Nilges, Peter; Schröder, Uwe

2015-03-01

Electroorganic synthesis can be exploited for the production of biofuels from fatty acids and triglycerides. With Coulomb efficiencies (CE) of up to 50 %, the electrochemical decarboxylation of fatty acids in methanolic and ethanolic solutions leads to the formation of diesel-like olefin/ether mixtures. Triglycerides can be directly converted in aqueous solutions by using sonoelectrochemistry, with olefins as the main products (with a CE of more than 20 %). The latter reaction, however, is terminated at around 50 % substrate conversion by the produced side-product glycerol. An energy analysis shows that the electrochemical olefin synthesis can be an energetically competitive, sustainable, and--in comparison with established processes--economically feasible alternative for the exploitation of fats and oils for biofuel production. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Distribution and condition of larval and juvenile Lost River and shortnose suckers in the Williamson River Delta restoration project and Upper Klamath Lake, Oregon

USGS Publications Warehouse

Burdick, Summer M.; Brown, Daniel T.

2010-01-01

Federally endangered Lost River sucker (Deltistes luxatus) and shortnose sucker (Chasmistes brevirostris) were once abundant throughout their range but populations have declined. They were extirpated from several lakes in the 1920s and may no longer reproduce in others. Poor recruitment to the adult spawning populations is one of several reasons cited for the decline and lack of recovery of these species and may be the consequence of high mortality during juvenile life stages. High larval and juvenile sucker mortality may be exacerbated by an insufficient quantity of suitable or high quality rearing habitat. In addition, larval suckers may be swept downstream from suitable rearing areas in Upper Klamath Lake into Keno Reservoir, which is seasonally anoxic. The Nature Conservancy flooded about 3,600 acres (1,456 hectares) to the north of the Williamson River mouth (Tulana Unit) in October 2007 and about 1,400 acres (567 hectares) to the south and east of the Williamson River mouth (Goose Bay Unit) a year later to retain larval suckers in Upper Klamath Lake, create nursery habitat, and improve water quality. The U.S. Geological Survey joined a long-term research and monitoring program in collaboration with The Nature Conservancy, the Bureau of Reclamation, and Oregon State University in 2008 to assess the effects of the Williamson River Delta restoration on the early life-history stages of Lost River and shortnose suckers. The primary objectives of the research were to describe habitat colonization and use by larval and juvenile suckers and non-sucker fishes and to evaluate the effects of the restored habitat on the health and condition of juvenile suckers. This report summarizes data collected in 2009 by the U.S. Geological Survey as a part of this monitoring effort. The Williamson River Delta appeared to provide suitable rearing habitat for endangered larval Lost River and shortnose suckers in 2008 and 2009. Larval suckers captured in this delta typically were larger than those captured in the adjacent lake habitat in 2008, but the opposite was true for larval shortnose suckers in 2009. Mean sample density was greater for both species in the Williamson River Delta than adjacent lake habitats in both years. Larval suckers captured in the restoration area, however, had less food in their guts compared to those captured in Upper Klamath or Agency Lakes. Differential distribution among sucker species within the Williamson River Delta and between the delta and adjacent lakes indicated that shortnose suckers likely benefited more from the restored Williamson River Delta than Lost River or Klamath largescale suckers (Catostomus snyderi). Catch rates in shallow-water habitats with vegetation within the delta were higher for shortnose and Klamath largescale suckers than for larval Lost River suckers in 2008 and 2009.However, catch rates at the mouth of the Williamson River in 2008 and in Upper Klamath Lake in 2009 were higher for larval Lost River suckers than for larvae identified as either shortnose or Klamath largescale suckers. Shortnose suckers also comprised the greatest portion of age-0 suckers captured in the Williamson River Delta in 2008 and 2009. The relative abundance of age-1 shortnose suckers was high in our catches compared to age-1 Lost River suckers in 2009 in the delta and adjacent lakes, which may or may not indicate shortnose suckers experienced better survival than Lost River suckers in 2008. Age-0 and age-1 suckers were similarly distributed throughout the Williamson River Delta in 2008 and 2009. Age-0 suckers used shallow vegetated and unvegetated habitats primarily in mid- to late July in both years. A comparison of catch rates between our study and a concurrent study in Upper Klamath Lake indicated that Goose Bay was the most used habitat in 2009 and the Tulana Unit was the one of the least used habitats in 2008 and 2009 by age-0 suckers. Catch rates for age-1 suckers, however, indicated that bo

Drug Development of the Antimalarial Agent Artemisinin: Total Synthesis, Analog Synthesis, and Structure-Activity Relationship Studies

DTIC Science & Technology

1990-08-15

16. SUPPLEMENTARY NOTATION 17 COSATi CODES FiELD 07 06 CROUP 03 01 SUB-GROUP IB SUBJECT TERMS (Cont/nu* on rtvtnt if ntctiwy *ne identity b ...number of requisite substituents resulted in the synthesis of ring cleaved analogs and partial structures of artemisinin: (+)-C/D, (+)-A/ B /C, (+)-A/C...in the preparation of the unstable aldehyde 2, and in commendable fashion others have employed an enol ether photo-oxygenation as entry to that

Comparison of historical streamflows to 2013 Streamflows in the Williamson, Sprague, and Wood Rivers, Upper Klamath Lake Basin, Oregon

USGS Publications Warehouse

Hess, Glen W.; Stonewall, Adam J.

2014-01-01

In 2013, the Upper Klamath Lake Basin, Oregon, experienced a dry spring, resulting in an executive order declaring a state of drought emergency in Klamath County. The 2013 drought limited the water supply and led to a near-total cessation of surface-water diversions for irrigation above Upper Klamath Lake once regulation was implemented. These conditions presented a unique opportunity to understand the effects of water right regulation on streamflows. The effects of regulation of diversions were evaluated by comparing measured 2013 streamflow with data from hydrologically similar years. Years with spring streamflow similar to that in 2013 measured at the Sprague River gage at Chiloquin from water years 1973 to 2012 were used to define a Composite Index Year (CIY; with diversions) for comparison to measured 2013 streamflows (no diversions). The best-fit 6 years (1977, 1981, 1990, 1991, 1994, and 2001) were used to determine the CIY. Two streams account for most of the streamflow into Upper Klamath Lake: the Williamson and Wood Rivers. Most streamflow into the lake is from the Williamson River Basin, which includes the Sprague River. Because most of the diversion regulation affecting the streamflow of the Williamson River occurred in the Sprague River Basin, and because of uncertainties about historical flows in a major diversion above the Williamson River gage, streamflow data from the Sprague River were used to estimate the change in streamflow from regulation of diversions for the Williamson River Basin. Changes in streamflow outside of the Sprague River Basin were likely minor relative to total streamflow. The effect of diversion regulation was evaluated using the “Baseflow Method,” which compared 2013 baseflow to baseflow of the CIY. The Baseflow Method reduces the potential effects of summer precipitation events on the calculations. A similar method using streamflow produced similar results, however, despite at least one summer precipitation event. The result of the analysis estimates that streamflow from the Williamson River Basin to Upper Klamath Lake increased by approximately 14,100 acre-feet between July 1 and September 30 relative to prior dry years as a result of regulation of surface-water diversions in 2013. Quantifying the change in streamflow from regulation of diversion for the Wood River Basin was likely less accurate due to a lack of long-term streamflow data. An increase in streamflow from regulation of diversions in the Wood River Basin of roughly 5,500 acre-feet was estimated by comparing the average August and September streamflow in 2013 with historical August and September streamflow. Summing the results of the estimated streamflow gain of the Williamson River Basin (14,100 acre-feet) and Wood River (5,500 acre-feet) gives a total estimated increase in streamflow into Upper Klamath Lake resulting from the July 1–September 2013 regulation of diversions of approximately 19,600 acre-feet.

A new intermediate for the production of flexible stable polymers

NASA Technical Reports Server (NTRS)

Webster, J. A.

1973-01-01

Method of incorporating ether linkages into perfluoroalkylene segment of a dianydride intermediate yields intermediate that may be used in synthesis of flexible, stable polyimides for use as high-temperature, solvent-resistant sealants.

75 FR 63521 - PSEG Power, LLC and PSEG Nuclear, LLC; PSEG Site Early Site Permit Application, Notice of Intent...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-15

.... Fetter or Ms. Alicia Williamson at 1-800-368- 5642, extensions 8556 or 1878, respectively. In addition... scoping process may be obtained from Mr. Allen Fetter or Ms. Alicia Williamson at the U.S. Nuclear... 8556 or 1878, respectively or via e-mail to [email protected] or Alicia[email protected] . Dated...

On-Line Retrieval System Design; Part V of Scientific Report No. ISR-18, Information Storage and Retrieval...

ERIC Educational Resources Information Center

Cornell Univ., Ithaca, NY. Dept. of Computer Science.

On-line retrieval system design is discussed in the two papers which make up Part Five of this report on Salton's Magical Automatic Retriever of Texts (SMART) project report. The first paper: "A Prototype On-Line Document Retrieval System" by D. Williamson and R. Williamson outlines a design for a SMART on-line document retrieval system…

Chemical synthesis of beta-O-4 type artificial lignin.

PubMed

Kishimoto, Takao; Uraki, Yasumitsu; Ubukata, Makoto

2006-04-07

An artificial lignin polymer containing only the beta-O-4 substructure was synthesized. The procedure consists of two key steps: 1) polycondensation of a brominated monomer by aromatic Williamson reaction; and 2) subsequent reduction of the carbonyl polymer. 13C-NMR and HMQC spectra of the polymer were consistent with beta-O-4 substructures in milled wood lignin isolated from Japanese fir wood. The weight average degree of polymerization (DP(w)) ranged from 19.5 to 30.6, which is comparable to enzymatically synthesized artificial lignin from p-hydroxycinnamyl alcohols (dehydrogenation polymer, DHP) and some isolated lignins. Using this new lignin model polymer, it will now be possible to reinvestigate the properties and reactivity of the main lignin structure in terms of its polymeric character.

Tandem intramolecular silylformylation and silicon-assisted cross-coupling reactions. synthesis of geometrically defined alpha,beta-unsaturated aldehydes.

PubMed

Denmark, Scott E; Kobayashi, Tetsuya

2003-06-27

The palladium- and copper-catalyzed cross-coupling reactions of cyclic silyl ethers with aryl iodides are reported. Silyl ethers 3 were readily prepared by intramolecular silylformylation of homopropargyl silyl ethers 2 under a carbon monoxide atmosphere. The reaction of cyclic silyl ethers 3with various aryl iodides 7 in the presence of [(allyl)PdCl](2), CuI, a hydrosilane, and KF.2H(2)O in DMF at room temperature provided the alpha,beta-unsaturated aldehyde coupling products 8 in high yields. The need for copper in this process suggested that transmetalation from silicon to copper is an important step in the mechanism. Although siloxane 3 and the product 8 are not stable under basic conditions, KF.2H(2)O provided the appropriate balance of reactivity toward silicon and reduced basicity. The addition of a hydrosilane to [(allyl)PdCl](2) was needed to reduce the palladium(II) to the active palladium(0) form.

Synthesis and pKa determination of new enantiopure dimethyl-substituted acridino-crown ethers containing a carboxyl group: Useful candidates for enantiomeric recognition studies.

PubMed

Németh, Tamás; Dargó, Gergő; Petró, József Levente; Petrik, Zsófia; Lévai, Sándor; Krámos, Balázs; Béni, Zoltán; Nagy, József; Balogh, György Tibor; Huszthy, Péter; Tóth, Tünde

2017-09-01

New enantiopure dimethyl-substituted acridino-18-crown-6 and acridino-21-crown-7 ethers containing a carboxyl group at position 9 of the acridine ring [(S,S)-8, (S,S)-9, (R,R)-10] were synthesized. The pK a values of the new crown ethers [(S,S)-8, (S,S)-9, (R,R)-10] and of an earlier reported macrocycle [(R,R)-2] were determined by UV-pH titrations. Crown ether (S,S)-8 was attached to silica gel by covalent bonds and the enantiomeric separation ability of the newly prepared chiral stationary phase [(S,S)-CSP-12] was studied by high-performance liquid chromatography (HPLC). Homochiral preference was observed and the best separation was achieved for the enantiomers of 1-NEA. Ligands (S,S)-9 and (R,R)-10 are precursors of enantioselective sensor and selector molecules for the enantiomers of protonated primary amines, amino acids, and their derivatives. © 2017 Wiley Periodicals, Inc.

Biomedical potentials of crown ethers: prospective antitumor agents.

PubMed

Kralj, Marijeta; Tusek-Bozić, Ljerka; Frkanec, Leo

2008-10-01

Crown ethers are of enormous interest and importance in chemistry, biochemistry, materials science, catalysis, separation, transport and encapsulated processes, as well as in the design and synthesis of various synthetic systems with specific properties, diverse capabilities, and programmable functions. Classical crown ethers are macrocyclic polyethers that contain 3-20 oxygen atoms separated from each other by two or more carbon atoms. They are exceptionally versatile in selectively binding a range of metal ions and a variety of organic neutral and ionic species. Crown ethers are currently being studied and used in a variety of applications beyond their traditional place in chemistry. This review presents additional applications and the ever-increasing biomedical potentials of these intriguing compounds, with particular emphasis on the prospects of their relevance as anticancer agents. We believe that further research in this direction should be encouraged, as crown compounds could either induce toxicities that are different from those of conventional antitumor drugs, or complement drugs in current use, thereby providing a valuable adjunct to therapy.

Chemoselective Cleavage of p-Methoxybenzyl and 2-Naphthylmethyl Ethers Using a Catalytic Amount of HCl in Hexafluoro-2-propanol.

PubMed

Volbeda, Anne Geert; Kistemaker, Hans A V; Overkleeft, Herman S; van der Marel, Gijsbert A; Filippov, Dmitri V; Codée, Jeroen D C

2015-09-04

A new, fast, mild and chemoselective deprotection method to cleave p-methoxybenzyl and 2-naphthylmethyl ethers using catalytic amounts of hydrochloric acid in a 1:1 mixture of hexafluoro-2-propanol (HFIP) and methylene chloride (DCM) is described. The scope of the methodology becomes apparent from 14 examples of orthogonally protected monosaccharides that are subjected to HCl/HFIP treatment. The applicability of the HCl/HFIP method is illustrated by the synthesis of a sulfated β-mannuronic acid disaccharide.

A Facile and Efficient Synthesis of Diaryl Amines or Ethers under Microwave Irradiation at Presence of KF/Al2O3 without Solvent and Their Anti-Fungal Biological Activities against Six Phytopathogens

PubMed Central

Huang, Liang-Zhu; Han, Pan; Li, You-Qiang; Xu, Ying-Meng; Zhang, Tao; Du, Zhen-Ting

2013-01-01

A series of diaryl amines, ethers and thioethers were synthesized under microwave irradiation efficiently at presence of KF/Al2O3 in 83%–96% yields without any solvent. The salient characters of this method lie in short reaction time, high yields, general applicability to substrates and simple workup procedure. At the same time, their antifungal biological activities against six phytopathogen were evaluated. Most of the compounds (3b, 3c, 3g–o) are more potent than thiophannate-methyl against to Magnaporthe oryzae. This implies that diaryl amine or ether moiety may be helpful in finding a fungicide against Magnaporthe oryzae. PMID:24036444

Wholly Aromatic Ether-imides. Potential Materials for n-Type Semiconductors

NASA Technical Reports Server (NTRS)

Dingemans, Theo J.; St.Clair, Terry L.; Samulski, Edward T.; Bushnell, Dennis M. (Technical Monitor)

2002-01-01

We report on the synthesis and characterization of a novel series low-molar-mass ether-imide rod-shaped model compounds. All ether-imides were obtained by terminating the appropriate rigid core dianhydride, i.e. pyromellitic dianhydride (PMDA), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), and 3,3,4,4'-oxydiphthalic dianhydride (ODPA) with three flexible aryl-ether tails of different chain length. The mono-functional aryl-ether amines, i.e. 4-(3-phenoxy-phenoxy)-phenylamine (2) and 4-(3-phenoxy-3-phenoxy-phenoxy)-phenylamine (4), were synthesized using standard fluoro-displacement and Ullmann condensation techniques. The corresponding ether-imide model compounds were obtained in high yields using a one-step solution imidization procedure. Increasing the number of meta-substituted aryl-ether units reduces the melt transition temperatures and at the same time it increases the solubility of the model compounds. Most model compounds are crystalline solids and form isotropic melts upon heating. 2,7-Bis-(-4-phenoxy-phenyl)-benzo[Imn][3,8]phenanthroline1,3,6,8-tetraone (NDA-n0), however, displays a smectic A (SA) when cooled from the isotropic phase, followed by what appears to be either a highly ordered smectic phase or a, columnar phase. This is the first example, known to date, in which a mesophase is detected in a wholly aromatic ether-imide compound. For all compounds we present spectroscopic data and X-ray diffraction data. Cyclic voltammetry was used to determine the redox behavior and pertinent energy levels of the model compounds.

A facile synthesis of highly stable multiblock poly(arylene ether)s based alkaline membranes for fuel cells

NASA Astrophysics Data System (ADS)

Jasti, Amaranadh; Shahi, Vinod K.

2014-12-01

Herein, we are disclosing simple route for the preparation of alkaline membranes (AMs) based on aminated multiblock poly(arylene ether)s (AMPEs) synthesized by nucleophilic substitution-poly condensation followed by quaternization and alkalization reactions. In this procedure, four quaternary ammonium groups are successfully introduced without use of carcinogenic reagents such as chloromethylmethyl ether (CMME). Hydrophilic/hydrophobic phase separation is responsible for their high hydroxide conductivity (∼150 mS cm-1 at 80 °C) due to development of interconnected ion transport pathway. AMs are exhibiting good alkaline stability due to the presence of two vicinal quaternary ammonium groups and avoid degradation such as Sommelet-Hauser rearrangement and Hofmann elimination. Vicinal quaternary ammonium groups also resist nucleophilic (OH-) attack and suppress the Stevens rearrangement as well as SN2 substitution reaction due to stearic hindrance. Optimized AM (AMPE-M20N15 (55% DCM)) exhibits about 0.95 V open circuit voltage (OCV) and 48.8 mW cm-2 power density at 65 °C in alkaline direct methanol fuel cell (ADMFC) operation. These results suggest promising begin for the preparation of stable and conductive AMs for ADMFC applications and useful for developing hydroxide conductive materials.

High Performance Solid Polymer Electrolytes for Rechargeable Batteries: A Self-Catalyzed Strategy toward Facile Synthesis.

PubMed

Cui, Yanyan; Liang, Xinmiao; Chai, Jingchao; Cui, Zili; Wang, Qinglei; He, Weisheng; Liu, Xiaochen; Liu, Zhihong; Cui, Guanglei; Feng, Jiwen

2017-11-01

It is urgent to seek high performance solid polymer electrolytes (SPEs) via a facile chemistry and simple process. The lithium salts are composed of complex anions that are stabilized by a Lewis acid agent. This Lewis acid can initiate the ring opening polymerization. Herein, a self-catalyzed strategy toward facile synthesis of crosslinked poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte (C-PEGDE) is presented. It is manifested that the poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte possesses a superior electrochemical stability window up to 4.5 V versus Li/Li + and considerable ionic conductivity of 8.9 × 10 -5 S cm -1 at ambient temperature. Moreover, the LiFePO 4 /C-PEGDE/Li batteries deliver stable charge/discharge profiles and considerable rate capability. It is demonstrated that this self-catalyzed strategy can be a very effective approach for high performance solid polymer electrolytes.

Synthesis, anticancer activity, and iron affinity of the Actinoplanes metabolite 7,8-dihydroxy-1-methylnaphtho[2,3-c]furan-4,9-dione.

PubMed

Breyer, Sandra; Effenberger-Neidnicht, Katharina; Knauer, Sebastian; Schobert, Rainer

2011-02-01

The first synthesis of 7,8-dihydroxy-1-methylnaphtho[2,3-c]furan-4,9-dione (1), an isofuranonaphthoquinone produced by an Actinoplanes strain is described. Lactone ring opening of 6-methylfuro[3,4-c]furan-1(3H)-one (4) with ortho-lithiated veratrole (3), oxidation of product alcohol 5, and Friedel-Crafts acylation of the resulting aroylcarboxylic acid 7 afforded the mono methyl ether 2 of the target compound. The latter was obtained by demethylation of 2 with BBr(3) in 14% overall yield. While mono ether 2 was distinctly more cytotoxic than catechol 1 against a panel of five cancer cell lines, only the latter showed a siderophore-like binding affinity for Fe(III) with a complex dissociation constant K(D) of approximately 10(-29) M(3) (pM = 25.9). Copyright © 2010 Elsevier Ltd. All rights reserved.

Oxidative Carbocation Formation in Macrocycles: Synthesis of the Neopeltolide Macrocycle**

PubMed Central

Tu, Wangyang

2009-01-01

Processes for the functionalization of carbon–hydrogen bonds are the focus of significant attention in organic synthesis[1] in response to the need to streamline molecular assembly. As a continuation of our efforts to generate carbocations through single-electron oxidation reactions,[2] we recently reported[3] DDQ-mediated cyclization reactions of benzylic and allylic ethers (Scheme 1; DDQ =2,3-dichloro-4,5-dicyanoquinone). PMID:19455526

Synthesis of Energetic Materials.

DTIC Science & Technology

1986-03-31

give the known’ enol ether 29. Upon 25 *hydrogenation, during which methyl migration from oxygen to nitrogen occurred, 29 gave the double lactam 30... enol acetate corresponding to structure 29. Hydrogenatio6-f 31J gave the N-acetyl double lactam 32. The first approach toward the synthesis of the...a condensation product 26 which was converted into the unsaturated double lactam 27. The chemistry of these materials were explored in detail in an

Platelet Activating Factor: A Growth Factor for Breast Cancer

DTIC Science & Technology

2006-09-01

synthase (ADS) increases ether lipid content, growth and PAF synthesis in MCF-7 cells. 4. Eicosapentaenoic acid (EPA) inhibits the synthesis of PAF...Schmitt, J. D., Bullock, B. C. Wykle, R. L. Reacylation of platelet activating factor with eicosapentaenoic acid in fish-oil-enriched monkey...breast cancer. Recent studies have shown that the ratio of two families of essential fatty acids is important in regulating many cellular processes

Total Synthesis of Strychnine.

PubMed

Lee, Geun Seok; Namkoong, Gil; Park, Jisook; Chen, David Y-K

2017-11-16

The total synthesis of the flagship Strychnos indole alkaloid, strychnine, has been accomplished. The developed synthetic sequence features a novel vinylogous 1,4-addition, a challenging iodinium salt mediated silyl enol ether arylation, a palladium-catalyzed Heck reaction, and a streamlined late-stage conversion to strychnine. Furthermore, an application of asymmetric counterion-directed catalysis (ACDC) in the context of target-oriented organic synthesis has been rendered access to an optically active material. The synthetic sequence described herein represents the most concise entry to optically active strychnine to date. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of the diazonium (perfluoroalkyl) benzenesulfonimide monomer from Nafion monomer for proton exchange membrane fuel cells

NASA Astrophysics Data System (ADS)

Mei, Hua; D'Andrea, Dan; Nguyen, Tuyet-Trinh; Nworie, Chima

2014-02-01

One diazonium (perfluoroalkyl) benzenesulfonimide monomer, perfluoro-3, 6-dioxa-4-methyl-7-octene benzenesulfonyl imide, has been synthesized from Nafion monomer for the first time. With trifluorovinyl ether and diazonium precursors, the partially-fluorinated diazonium PFSI monomer can be polymerized and will provide chemically bonding with carbon electrode in proton exchange membrane fuel cells. A systematic study of the synthesis and characterization of this diazonium PFSI monomer has been conducted by varying reaction conditions. The optimized synthesis method has been established in the lab.

THE CHEMISTRY OF ARSINE OXIDES RELATED TO THE SYNTHESIS OF ARSENOSUGARS

EPA Science Inventory

Ongoing toxicokinetic and biogenesis investigations require gram quantities of the naturally occurring dimethylarsinoylribofuranosides. The principal synthetic route to these compounds involves the hydrogen peroxide oxidation of the parent arsine in ether. This reaction is hazar...

Synthesis and Characterization of Hydrophilic-Hydrophobic Poly(Arylene Ether Sulfone) Random and Segmented Copolymers for Membrane Applications

NASA Astrophysics Data System (ADS)

Nebipasagil, Ali

Poly(arylene ether sulfone)s are high-performance engineering thermoplastics that have been investigated extensively over the past several decades due to their outstanding mechanical properties, high glass transition temperatures (Tg), solvent resistance and exceptional thermal, oxidative and hydrolytic stability. Their thermal and mechanical properties are highly suited to a variety of applications including membrane applications such as reverse osmosis, ultrafiltration, and gas separation. This dissertation covers structure-property-performance relationships of poly(arylene ether sulfone) and poly(ethylene oxide)-containing random and segmented copolymers for reverse osmosis and gas separation membranes. The second chapter of this dissertation describes synthesis of disulfonated poly(arylene ether sulfone) random copolymers with oligomeric molecular weights that contain hydrophilic and hydrophobic segments for thin film composite (TFC) reverse osmosis membranes. These copolymers were synthesized and chemically modified to obtain novel crosslinkable poly(arylene ether sulfone) oligomers with acrylamide groups on both ends. The acrylamideterminated oligomers were crosslinked with UV radiation in the presence of a multifunctional acrylate and a UV initiator. Transparent, dense films were obtained with high gel fractions. Mechanically robust TFC membranes were prepared from either aqueous or water-methanol solutions cast onto a commercial UDELRTM foam support. This was the first example that utilized a water or alcohol solvent system and UV radiation to obtain reverse osmosis TFC membranes. The membranes were characterized with regard to composition, surface properties, and water uptake. Water and salt transport properties were elucidated at the department of chemical engineering at the University of Texas at Austin. The gas separation membranes presented in chapter three were poly(arylene ether sulfone) and poly(ethylene oxide) (PEO)-containing polyurethanes. Poly(arylene ether sulfone) copolymers with controlled molecular weights were synthesized and chemically modified to obtain poly(arylene ether sulfone) polyols with aliphatic hydroxyethyl terminal functionality. The hydroxyethyl-terminated oligomers and a,u-hydroxy-terminated PEO were chain extended with a diisocyanate to obtain polyurethanes. Compositions with high poly(arylene ether sulfone) content relative to the hydrophilic PEO blocks were of interest due to their mechanical integrity. The membranes were characterized to analyze their compositions, thermal and mechanical properties, water uptake, and molecular weights. These membranes were also evaluated by collaborators at the University of Texas at Austin to explore single gas transport properties. The results showed that both polymer and transport properties closely related to PEO-content. The CO2/CH4 gas selectivity of our membranes were improved from 25 to 34 and the CO2/N2 gas selectivity nearly doubled from 25 to 46 by increasing PEO-content from 0 to 30 wt.% in polyurethanes. Chapter four also focuses on polymers for gas separation membranes. Disulfonated poly(arylene ether sulfone) and poly(ethylene oxide)-containing polyurethanes were synthesized for potential applications as gas separation membranes. Disulfonated polyols containing 20 and 40 mole percent of disulfonated repeat units with controlled molecular weights were synthesized. Poly(arylene ether sulfone) polyols and alpha,o-hydroxy-terminated poly(ethylene oxide) were subsequently chain extended with a diisocyanate to obtain polyurethanes. Thermal and mechanical characterization revealed that the polyurethanes had a phase-mixed complex morphology.

Functional Aromatic Poly(1,3,4-Oxadiazole-Ether)s with Benzimidazole Pendants: Synthesis, Thermal and Dielectric Studies

PubMed Central

Ganesh, Shimoga D.; Pai, Vasantakumar K.; Kariduraganavar, Mahadevappa Y.; Jayanna, Madhu B.

2014-01-01

Poly(1,3,4-oxadiazole-ether) with reactive carboxylic acid pendants was synthesized from solution polymerization via nucleophilic displacement polycondensation among 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole (BFPOx) and 4,4′-bis(4-hydroxyphenyl) valeric acid (BHPA). Without altering the polymeric segments, benzimidazole modified poly(1,3,4-oxadiazole-ether)s were prepared by varying stoichiometric ratios of 1,2-phenylenediamine. The molecular structural characterization of these polymers was achieved by, FT-IR, NMR, TGA, elemental analysis, and analytical techniques. The weight-average molecular weight of virgin polymer with carboxylic acid functionality was determined by gel permeation chromatography (GPC) and was found to be 22400 (Mw/Mn = 2.07). All the synthesized polyethers were compressed into pellets and electrical contacts were established to perform dielectric properties. PMID:27437448

Factors Influencing Food Choices of 4-H Club Members in Williamson County, Tennessee. A Research Summary of a Graduate Study.

ERIC Educational Resources Information Center

Geary, Virginia Ruth; And Others

A study was conducted to identify some of the eating habits and factors influencing food choices of selected junior (9 to 13 years old) and senior (14 to 19 years old) 4-H club members enrolled in Williamson County, Tennessee, in 1968. Data were collected through group interviews with 200 juniors and 70 seniors--116 boys and 154 girls.…

Sociable Machines: Expressive Social Exchange between Humans and Robots

DTIC Science & Technology

2000-05-01

many occasions about theories on emotion. I’ve cornered Robert Irie’s again and again about auditory processing. I’ve bugged Matto Marjanovic throughout...development at the MIT Artificial Intel- ligence Lab (Brooks, Breazeal, Marjanovic , Scassellati & Williamson 1999). Cog is a general purpose humanoid...RA-2, 253-262. Brooks, R. A., Breazeal, C., Marjanovic , M., Scassellati, B. & Williamson, M. M. (1999), The Cog Project: Building a Humanoid Robot, in

Numerical study of unsteady Williamson fluid flow and heat transfer in the presence of MHD through a permeable stretching surface

NASA Astrophysics Data System (ADS)

Bibi, Madiha; Khalil-Ur-Rehman; Malik, M. Y.; Tahir, M.

2018-04-01

In the present article, unsteady flow field characteristics of the Williamson fluid model are explored. The nanosized particles are suspended in the flow regime having the interaction of a magnetic field. The fluid flow is induced due to a stretching permeable surface. The flow model is controlled through coupled partial differential equations to the used shooting method for a numerical solution. The obtained partial differential equations are converted into ordinary differential equations as an initial value problem. The shooting method is used to find a numerical solution. The mathematical modeling yields physical parameters, namely the Weissenberg number, the Prandtl number, the unsteadiness parameter, the magnetic parameter, the mass transfer parameter, the Lewis number, the thermophoresis parameter and Brownian parameters. It is found that the Williamson fluid velocity, temperature and nanoparticles concentration are a decreasing function of the unsteadiness parameter.

Syntheses of all the possible monomethyl ethers and several deoxyhalo analogues of methyl beta-lactoside as ligands for the Ricinus communis lectins.

PubMed

Fernández, P; Jiménez-Barbero, J; Martín-Lomas, M

1994-02-17

The synthesis of all the possible monomethyl ethers of methyl beta-lactoside (1) has been performed from 1 in a straightforward way, making use of the different reactivity of the hydroxyl groups in alkylation and stannylation reactions. In addition, the deoxyfluoro derivatives of 1 at positions, 6,3',4',epi-4', and 6' have been prepared by reaction of the appropriate substrates with diethylaminosulfur trifluoride or tetrabutylammonium fluoride. Finally, the 6-deoxyiodo and 6'-bromodeoxy analogues of 1 have also been prepared.

New Linear and Star-Shaped Thermogelling Poly([R]-3-hydroxybutyrate) Copolymers.

PubMed

Barouti, Ghislaine; Liow, Sing Shy; Dou, Qingqing; Ye, Hongye; Orione, Clément; Guillaume, Sophie M; Loh, Xian Jun

2016-07-18

The synthesis of multi-arm poly([R]-3-hydroxybutyrate) (PHB)-based triblock copolymers (poly([R]-3-hydroxybutyrate)-b-poly(N-isopropylacrylamide)-b-[[poly(methyl ether methacrylate)-g-poly(ethylene glycol)]-co-[poly(methacrylate)-g-poly(propylene glycol)

Microwave-Assisted Synthesis of Mesoporous Nano-Hydroxyapatite Using Surfactant Templates

EPA Science Inventory

Mesoporous nano-hydroxyapatite (n-HAP) was expeditiously synthesized using the pseudo sol-gel microwave-assisted protocol (30 min) in the presence of two novel templates, namely sodium lauryl ether sulfate (SLES) and linear alkylbenzenesulfonate (LABS). The cooperative self-assem...

The Synthesis of Tetraamino Aryl Ethers.

DTIC Science & Technology

1975-01-01

FJSRL-TR-75-0001 with melting points over 500 C and solubilities restricted to strong acids such as sulfuric (H2S04) or methane sulfonic (CH3SO3H...Buchi Rotavapor. Melting points were determined on a Kofler melting point apparatus and are uncorrected. Elemefital microanalyses were per- formed by...Polymerizations in organic solvents, in melts and in polyphosphoric acid (PPA) or similar materials have been used suc- cessfully in their synthesis. The

One-Pot Catalytic Enantio- and Diastereoselective Syntheses of anti-, syn-cis-Disubstituted, and syn-Vinyl Cyclopropyl Alcohols

PubMed Central

Kim, Hun Young; Salvi, Luca; Carroll, Patrick J.; Walsh, Patrick J.

2009-01-01

Highly enantio- and diastereoselective methods for the synthesis of a variety of cyclopropyl alcohols are reported. These methods represent the first one-pot approaches to syn-vinyl cyclopropyl alcohols, syn-cis-disubstituted cyclopropyl alcohols, and anti-cyclopropyl alcohols from achiral precursors. The methods begin with enantioselective C–C bond formations promoted by a MIB-based zinc catalyst to generate allylic alkoxide intermediates. The intermediates are then subjected to in situ alkoxide-directed cyclopropanation to provide cyclopropyl alcohols. In the synthesis of vinyl cyclopropyl alcohols, hydroboration of enynes is followed by transmetalation of the resulting dienylborane to zinc to provide dienylzinc reagents. Enantioselective addition to aldehydes generates the requisite dienyl zinc alkoxides, which are then subjected to in situ cyclopropanation to furnish vinyl cyclopropyl alcohols. Cyclopropanation occurs at the double bond allylic to the alkoxide. Using this method, syn-vinylcyclopropyl alcohols are obtained in 65–85% yield, 76–93% ee, and >19:1 dr. To prepare anti-cyclopropanols, enantioselective addition of alkylzinc reagents to conjugated enals provides allylic zinc alkoxides. Because direct cyclopropanation provides syn-cyclopropyl alcohols, the intermediate allylic alkoxides were treated with TMSCl/Et3N to generate intermediate silyl ethers. In situ cyclopropanation of the allylic silyl ether resulted in cyclopropanation to form the anti-cyclopropyl silyl ether. Workup with TBAF affords the anti-cyclopropyl alcohols in one-pot in 60–82% yield, 89–99% ee, and ≥10:1 dr. For the synthesis of cis-disubstituted cyclopropyl alcohols, in situ generated (Z)-vinyl zinc reagents were employed in asymmetric addition to aldehydes to generate (Z)-allylic zinc alkoxides. In situ cyclopropanation provides syn-cis-disubstituted cyclopropyl alcohols in 42–70% yield, 88–97% ee, and >19:1 dr. These one-pot procedures enable the synthesis of a diverse array of cyclopropyl alcohol building blocks with high enantio- and diastereoselectivities. PMID:19954146

An Analysis of the Metrics Used in the United States Navy’s Enlisted Supply Chain As They Apply to the Royal Australian Navy

DTIC Science & Technology

2012-12-01

and Hill, 1988; Williamson, 1981), enhances socialization (Edwards, 1979), and lowers transaction costs ( Mahoney , 1992; Williamson, 1975). It does...much information as possible about its workforce to ensure it is managed effectively and efficiently (Davidson & Newman , 2006). Data measurement of...112 Cappelli, P. (2009b). A Supply Chain Approach to Workforce Planning. Organizational Dynamics, 38(1), 8–15. Davidson, G., & Newman , E

Toughening of BIS maleimide resins: Synthesis and characterization of maleimide terminated poly(arylene ether) oligomers and polymers

NASA Technical Reports Server (NTRS)

Mcgrath, J. E.; Lyle, G. D.; Jurek, M. J.; Mohanty, D.; Hedrick, J. C.

1986-01-01

Amine functional poly(arylene ether) sulfones were previously reported. Herein, the chemistry was extended to amorphous poly(arylene ether) ketones because of their higher fracture toughness values, relative to the polysulfones. It was demonstrated that the amino functional oligomers undergo a self-crosslinking reaction at temperatures above about 220 C. This produces an insoluble, but ductile network that has excellent resistance. A ketamine structure hypothesis was proposed and verified using solid state magic angle NMR. In most cases, the water generated upon ketamine formation is too low to produce porosity and solid networks are obtained. The stability of the ketamine networks towards hydrolysis is excellent. The chemistry was further demonstrated to be able to crosslink preformed nonfunctional poly(arylene ether) ketones if a difunctional amine was utilized. This concept has the possibility of greatly improving the creep resistance of thermoplastics. Also, a new technique was developed for converting the amine functional oligomers cleanly into maleimide structures. This method involves reacting maleic anhydride with monomeric aminophenols in the presence of solvent mixtures.

Intrinsic Kinetics of Dimethyl Ether Synthesis from Plasma Activation of CO2 Hydrogenation over Cu-Fe-Ce/HZSM-5.

PubMed

Su, Tongming; Zhou, Xinhui; Qin, Zuzeng; Ji, Hongbing

2017-02-02

CO 2 is activated in a plasma reactor followed by hydrogenation over a Cu-Fe-Ce/HZSM-5 catalyst, and the intrinsic kinetics of the plasma catalytic process are studied. Compared with CO 2 hydrogenation using Cu-Fe-Ce/HZSM-5 alone, the CO 2 conversion and the dimethyl ether selectivity for the plasma catalytic process are increased by 16.3 %, and 10.1 %, respectively, indicating that the CO 2 was activated by the plasma to promote hydrogenation. A study of the intrinsic kinetics shows that the activation energies of methanol formation, the reverse water-gas shift reaction, and methanol dehydration to dimethyl ether are 149.34, 75.47, and 73.18 kJ mol -1 , respectively, which are lower than if Cu-Fe-Ce/HZSM-5 is used without plasma, indicating that the activation of CO 2 in the plasma reduces the activation energy of the hydrogenation reaction and improves the yield of dimethyl ether. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ultrasonically assisted synthesis of lead oxide nanoflowers using ball milling

NASA Astrophysics Data System (ADS)

Bangi, Uzma K. H.; Park, Hyung-Ho; Han, Wooje; Prakshale, Vipul M.; Deshmukh, Lalasaheb P.

2017-05-01

The experimental results on the ultrasonically assisted synthesis of lead oxide nanoflowers using ball milling have been reported in the present work. Lead oxide nanoflowers were prepared employing mixed ligands by subjecting the formed precipitate to ultrasonication and grinding/ball milling. The effect of ball milling as well as fine grinding in agate mortar on the microstructure and surface morphology of the lead oxide was studied. The characteristics of synthesized PbO were studied using X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and field emission scanning electron microscopy techniques. XRD results demonstrated the tetragonal phase of PbO with crystallite size of around 25 nm and strain of 3.6 × 10-3 calculated from Williamson-Hall plot. FESEM images manifested the formation of nanodiscs and nanoflowers with a diameter of around 300 nm and thickness of 50 nm. XPS spectra revealed the formation of PbO with photoelectron peak of Pb 4f and O 1 s lied at 137.68 and 529.96 eV. Moreover, FTIR spectrum exhibited Pb-O bond peak in the range of 400-530 cm-1.

The Synthesis and Characterization of Tetrakis [(p - amino phenoxy) methyl] methane

NASA Astrophysics Data System (ADS)

Peng, Yongli; Zou, Qian

2017-06-01

In order to solve the shortcomings of the cured epoxy resin poor toughness, this paper proceeded from the structural design of curing agent to synthesize a special curing agent tetrakis [(p-aminophenoxy) methyl] methane which containing both Benzene ring and amino group. A Symmetric compound of tetrakis [(p - acetamidophenoxy) methyl] methane was prepared by using simple and easy to get pentaerythritoltetratosylate and acetaminophen for raw materials, after Williamson etherification reaction intermediates for synthesis of a symmetrical structure of the compound tetrakis [(p-acetamido phenoxy) methyl] methane, then hydrolysed under acidic conditions it can be tetrakis [(p-amino phenoxy) methyl] methane. The influence of reaction time, reaction temperature and reactant ratio to production yield of tetrakis [(p - acetamidophenoxy) methyl] methane was studied by orthogonal experiment of three factors and three levels, and get the optimal process parameters: the reaction time: 16 h, the reaction temperature: 170 °C, reactant ratio, 1:5. The Structure of tetrakis [(p - acetamidophenoxy) methyl] methane and tetrakis [(p-amino phenoxy) methyl] methane were characterized by infrared and 1H-NMR.

Synthesis of new high performance lubricants and solid lubricants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lagow, Richard J.

1993-04-08

In our second year of funding we began the testing phase of a number of new classes of lubricants. Three different testing collaborations have already begun and a fourth one is In the works with Dr. Stephen Hsu of the National Institute of Standards and Technology. Dr. Hsu also plans to test some of the same materials for us that Shell Development is studying. With Dr. Bill Jones of NASA, we are studying the effects of branching an high temperature lubricant properties in perfluoropolyethers, Initially Bill Jones is comparing the lubrication and physical properties of perfluorotetraglyme and the following twomore » spherical perfluoropolyethers, Note that one contains a fluorocarbon chain and the other one contains a fluorocarbon ether chain. The synthesis of these was reported in the last progress report. With Professor Patricia Thiel of Iowa State University, we are working on studies of perfluoromethylene oxide ethers and have prepared a series of four of these polyethers to study in collaboration with her research group. These perfluoromethylene oxide ethers have the best low temperature properties of any known lubricants. Thiel's group is studying their interactions with metals under extreme conditions. Thirdly, we have also begun an Interaction with W. August Birke of Shell Development Company in Houston for whom we have already prepared samples of the chlorine-substituted fluorocarbon polyether lubricants whose structures appear on page 54 of our research proposal. Each of these four structures is thought to have potential as lubricant additives to motor oils. We also have underway syntheses of other fluorine-containing branched ether lubricants. These new materials which are also promising as antifriction additives for motor oils appear ahead of the perfluoro additives as Appendix I to the progress report. Additionally for Birke and Shell Development we have at their request prepared the novel compound perfluoro salicylic acid. This synthesis was suggested by the Shell staff who thought that esters of perfluoro salicylic acid might be an excellent antifriction additive for motor oil fuels. One of the best additives currently used in motor oils is the hydrocarbon ester of salicylic acid.« less

Synthesis of ketones from biomass-derived feedstock.

PubMed

Meng, Qinglei; Hou, Minqiang; Liu, Huizhen; Song, Jinliang; Han, Buxing

2017-01-31

Cyclohexanone and its derivatives are very important chemicals, which are currently produced mainly by oxidation of cyclohexane or alkylcyclohexane, hydrogenation of phenols, and alkylation of cyclohexanone. Here we report that bromide salt-modified Pd/C in H 2 O/CH 2 Cl 2 can efficiently catalyse the transformation of aromatic ethers, which can be derived from biomass, to cyclohexanone and its derivatives via hydrogenation and hydrolysis processes. The yield of cyclohexanone from anisole can reach 96%, and the yields of cyclohexanone derivatives produced from the aromatic ethers, which can be extracted from plants or derived from lignin, are also satisfactory. Detailed study shows that the Pd, bromide salt and H 2 O/CH 2 Cl 2 work cooperatively to promote the desired reaction and inhibit the side reaction. Thus high yields of desired products can be obtained. This work opens the way for production of ketones from aromatic ethers that can be derived from biomass.

Trifluoromethyl ethers – synthesis and properties of an unusual substituent

PubMed Central

Manteau, Baptiste; Vors, Jean-Pierre; Pazenok, Sergiy

2008-01-01

Summary After nitrogen, fluorine is probably the next most favorite hetero-atom for incorporation into small molecules in life science-oriented research. This review focuses on a particular fluorinated substituent, the trifluoromethoxy group, which is finding increased utility as a substituent in bioactives, but it is still perhaps the least well understood fluorine substituent in currency. The present review will give an overview of the synthesis, properties and reactivity of this important substituent. PMID:18941485

Scientific bases of biomass processing into basic component of aviation fuel

NASA Astrophysics Data System (ADS)

Kachalov, V. V.; Lavrenov, V. A.; Lishchiner, I. I.; Malova, O. V.; Tarasov, A. L.; Zaichenko, V. M.

2016-11-01

A combination of feedstock pyrolysis and the cracking of the volatile pyrolysis products on the charcoal at 1000 °C allows to obtain a tarless synthesis gas which contains 90 vol% or more of carbon monoxide and hydrogen in approximately equal proportions. Basic component of aviation fuel was synthesized in a two-stage process from gas obtained by pyrolytic processing of biomass. Methanol and dimethyl ether can be efficiently produced in a two-layer loading of methanolic catalyst and γ-Al2O3. The total conversion of CO per pass was 38.2% using for the synthesis of oxygenates a synthesis gas with adverse ratio of H2/CO = 0.96. Conversion of CO to CH3OH was 15.3% and the conversion of CO to dimethyl ether was 20.9%. A high yield of basic component per oxygenates mass (44.6%) was obtained during conversion. The high selectivity of the synthesis process for liquid hydrocarbons was observed. An optimal recipe of aviation fuel B-92 based on a synthesized basic component was developed. The prototype of aviation fuel meets the requirements for B-92 when straight fractions of 50-100 °C (up to 35 wt%), isooctane (up to 10 wt%) and ethyl fluid (2.0 g/kg calculated as tetraethyl lead) is added to the basic component.

Chesapeake Bay Study. Supplement A. Problem Identification. Supplement B. Public Involvement. Supplement C. The Chesapeake Bay Hydraulic Model.

DTIC Science & Technology

1984-09-01

1968-71 Dr. Francis S. L. Williamson, 1971-75 Dr. J. Kevin Sullivan, 1975-83 Dr. David L. Correll, 1983-84 B-I...BASIC RESEARCH (cont’d) SMITHSONIAN INSTITUTION Dr. I. Eugene Wallen, 1968-71 Dr. Francis S. L. Williamson, 1971-75 Dr. 3. Kevin Sullivan, 1975-83 Dr...MSX merical fishino and recrea- by increased distributions of waer sources fromsaltitru- the B E P predicted oysters tion industries and for the

Proposal and Testing of a Methodology for Evaluating an Occupational Health Program at a U.S. Army Installation

DTIC Science & Technology

1983-08-01

the literature for ten of the thirteen peptic ulcer diagnostic criteria most often cited in predeveloped listings compiled by various professional...Dershewitz, M.D., Richard A. Gross, M.D., and John W. Williamson, M.D., "Validating Audit Criteria: An Analytic Approach Illustrated by Peptic Ulcer ...A., M.D.; Gross, Richard A., M.D.; and Williamson, John W., M.D., "Validating Audit Criteria: An Analytic Approach Illustrated by Peptic Ulcer Disease

Synthesis and properties of a bio-based epoxy resin with high epoxy value and low viscosity.

PubMed

Ma, Songqi; Liu, Xiaoqing; Fan, Libo; Jiang, Yanhua; Cao, Lijun; Tang, Zhaobin; Zhu, Jin

2014-02-01

A bio-based epoxy resin (denoted TEIA) with high epoxy value (1.16) and low viscosity (0.92 Pa s, 258C) was synthesized from itaconic acid and its chemical structure was confirmed by 1H NMR and 13C NMR spectroscopy. Its curing reaction with poly(propylene glycol) bis(2-aminopropyl ether) (D230) and methyl hexahydrophthalic anhydride (MHHPA) was investigated. For comparison, the commonly used diglycidyl ether of bisphenol A (DGEBA) was also cured with the same curing agents. The results demonstrated that TEIA showed higher curing reactivity towards D230/MHHPA and lower viscosity compared with DGEBA, resulting in the better processability. Owing to its high epoxy value and unique structure, comparable or better glass transition temperature as well as mechanical properties could be obtained for the TEIA-based network relative to the DGEBA-based network. The results indicated that itaconic acid is a promising renewable feedstock for the synthesis of bio-based epoxy resin with high performance.

Aqua complexes of 18—crown-6 with H 3PO 4, H 2TiF 6, and HNO 3: synthesis and vibrational spectra

NASA Astrophysics Data System (ADS)

Chénevert, R.; Rodrigue, A.; Chamberland, D.; Ouellet, J.; Savoie, R.

1985-11-01

Neutral-component complexes of 2:3:1 (acid:water:18-crown-6) stoichiometry have been obtained with H 3PO 4 and H 2TiF 6. These adducts have been studied by infrared and Raman spectroscopy, along with the corresponding (HNO 3-H 1O) 2-18-crown-6 complex, whose synthesis has already been reported. The spectra indicate that the crown ether has a highly regular conformation in these complexes. In those with H 3PO 4 and HNO 3, the binding of the acid molecule to the ether takes place through a H 2O linker, the strength of the XOH⋯OH 2 hydrogen bond being directly related to the p K a of the acid. With HNO 3, the acidic proton appears to be delocalized between the two oxygen atoms, giving a pseudo H 2O + ion whereas in the corresponding deuterocompound the D atom remains associated with the acid.

Natural zinniol derivatives from Alternaria tagetica. Isolation, synthesis, and structure-activity correlation.

PubMed

Gamboa-Angulo, M Marcela; Escalante-Erosa, Fabiola; García-Sosa, Karlina; Alejos-González, Fátima; Delgado-Lamas, Guillermo; Peña-Rodríguez, Luis M

2002-02-27

Two novel phytotoxins, 8-zinniol methyl ether (5) and 8-zinniol acetate (6), in addition to 6-(3',3'-dimethylallyloxy)-4-methoxy-5-methylphthalide (2), 5-(3',3'-dimethylallyloxy)-7-methoxy-6-methylphthalide (3), and the novel metabolites 8-zinniol 2-(phenyl)ethyl ether (4) and 7-zinniol acetate (7) have been identified as natural zinniol derivatives from the organic crude extract of Alternaria tagetica culture filtrates. Using zinniol as the starting material, phytotoxin 5 was synthesized, together with a number of synthetic intermediates (8-13). Both natural and synthetic zinniol derivatives were evaluated in the leaf-spot bioassay against marigold leaves (Tagetes erecta).

Synthesis and antiviral activity of certain second generation methylenecyclopropane nucleosides

PubMed Central

Williams, John D.; Khan, Atiyya R.; Harden, Emma A.; Hartline, Caroll B.; Jefferson, Geraldine M.; Keith, Kathy A.; Prichard, Mark N.; Zemlicka, Jiri; Peet, Norton P.; Bowlin, Terry L.

2012-01-01

A second-generation series of substituted methylenecyclopropane nucleosides (MCPNs) has been synthesized and evaluated for antiviral activity against a panel of human herpesviruses, and for cytotoxicity. Although alkylated 2,6-diaminopurine analogs showed little antiviral activity, the compounds containing ether and thioether substituents at the 6-position of the purine did demonstrate potent and selective antiviral activity against several different human herpesviruses. In the 6-alkoxy series, antiviral activity depended on the length of the ether carbon chain, with the optimum chain length being about four carbon units long. For the corresponding thioethers, compounds containing secondary thioethers were more potent than those with primary thioethers. PMID:22607883

Tailor-made Molecular Cobalt Catalyst System for the Selective Transformation of Carbon Dioxide to Dialkoxymethane Ethers.

PubMed

Schieweck, Benjamin G; Klankermayer, Jürgen

2017-08-28

Herein a non-precious transition-metal catalyst system for the selective synthesis of dialkoxymethane ethers from carbon dioxide and molecular hydrogen is presented. The development of a tailored catalyst system based on cobalt salts in combination with selected Triphos ligands and acidic co-catalysts enabled a synthetic pathway, avoiding the oxidation of methanol to attain the formaldehyde level of the central CH 2 unit. This unprecedented productivity based on the molecular cobalt catalyst is the first example of a non-precious transition-metal system for this transformation utilizing renewable carbon dioxide sources. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design and synthesis of new adamantyl-substituted antileishmanial ether phospholipids.

PubMed

Papanastasiou, Ioannis; Prousis, Kyriakos C; Georgikopoulou, Kalliopi; Pavlidis, Theofilos; Scoulica, Effie; Kolocouris, Nicolas; Calogeropoulou, Theodora

2010-09-15

A series of new 2-[3-(2-alkyloxy-ethyl)-adamantan-1-yl]-ethoxy substituted ether phospholipids was synthesized and their antileishmanial activity was evaluated against Leishmania infantum amastigotes. The majority of the new analogues were significantly less cytotoxic than miltefosine while, antiparasitic activity depended on the length of the 2-alkyloxy substituent. The most potent compounds were {2-[[[3-(2-hexyloxy-ethyl)-adamant-1-yl]-ethoxy]hydroxyphosphinyloxy]ethyl}-Nu,Nu,Nu-trimethyl-ammonium inner salt (5b) and {2-[[[3-(2-octyloxy-ethyl)-adamant-1-yl]-ethoxy]hydroxyphosphinyloxy]ethyl}-Nu,Nu,Nu-trimethyl-ammonium inner salt (5c). Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Synthesis of uniform cyclodextrin thioethers to transport hydrophobic drugs

PubMed Central

Becker, Lisa F; Schwarz, Dennis H

2014-01-01

Summary Methyl and ethyl thioether groups were introduced at all primary positions of α-, β-, and γ-cyclodextrin by nucleophilic displacement reactions starting from the corresponding per-(6-deoxy-6-bromo)cyclodextrins. Further modification of all 2-OH positions by etherification with iodo terminated triethylene glycol monomethyl ether (and tetraethylene glycol monomethyl ether, respectively) furnished water-soluble hosts. Especially the β-cyclodextrin derivatives exhibit very high binding potentials towards the anaesthetic drugs sevoflurane and halothane. Since the resulting inclusion compounds are highly soluble in water at temperatures ≤37 °C they are good candidates for new aqueous dosage forms which would avoid inhalation anaesthesia. PMID:25550759

Synthesis and Characterization of Polyimides with Ether Linkages

NASA Technical Reports Server (NTRS)

Chuang, Kathy C.; Fu, Joyce; Scheiman, Daniel A.

1998-01-01

A series of polyimides derived from a newly synthesized diamine, namely, 4,4-bis(4-aminophenoxy)-2,2-dimethylbiphenyl (BAPD), were developed and characterized. Their physical and thermal properties were compared to polyimides based on'commercially available 2,2-bis(4-(4-aminophenoxy)phenyl)propane (BAPP).

Synthesis of analogues of Eunicea gamma-cembranolides containing cyclic ethers via saponification.

PubMed

Rodríguez, A D; Piña, I C; Acosta, A L; Ramírez, C; Soto, J J

2001-02-09

A method for the synthesis of derivatives of the lead structures euniolide (1), 12,13-bisepieupalmerin (2), and eupalmerin acetate (3) containing tetrahydrofuran and tetrahydropyran ring systems was developed on the basis of alkali-induced intramolecular oxacyclizations. Representatives of the new analogues were submitted to the in vitro antitumor cell-line-screening program of the National Cancer Institute (NCI). While it was shown that a variety of structural modifications are possible, these transformations led typically to nontoxic synthetic cembranoids.

Synthesis and x-ray crystallographic analysis of 4,6-di-O-acetyl-2,3-dideoxy-α-D-threo-hexopyranosyl cyanide.

PubMed

Rotella, Madeline; Giovine, Matthew; Dougherty, William; Boyko, Walter; Kassel, Scott; Giuliano, Robert

2016-04-29

The glycopyranosyl cyanide 4,6-di-O-acetyl-2,3-dideoxy-α-D-threo-hexopyranosyl cyanide has been synthesized from tri-O-acetyl-D-galactal by reaction with trimethylsilyl cyanide in the presence of boron trifluoride diethyl etherate followed by catalytic hydrogenation. The synthesis provides the α-anomer stereoselectively, the structure of which was assigned based on 2D NMR techniques and x-ray crystallography. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and characteristics of polyarylene ether sulfones

NASA Technical Reports Server (NTRS)

Viswanathan, R.; Johnson, B. C.; Ward, T. C.; Mcgrath, J. E.

1981-01-01

A method utilizing potassium carbonate/dimethyl acetamide, as base and solvent respectively, was used for the synthesis of several homopolymers and copolymers derived from various bisphenols. It is demonstrated that this method deviates from simple second order kinetics; this deviation being due to the heterogeneous nature of the reaction. Also, it is shown that a liquid induced crystallization process can improve the solvent resistance of these polymers. Finally, a Monte Carlo simulation of the triad distribution of monomers in nonequilibrium copolycondensation is discussed.

Synthesis of hydrocarbons by CO2 fluid conversion with hydrogen: Experimental modeling at 7.8 GPa and 1350°C

NASA Astrophysics Data System (ADS)

Sokol, A. G.; Tomilenko, A. A.; Bul'bak, T. A.; Sobolev, N. V.

2017-12-01

Synthesis of hydrocarbons by the interaction of a CO2 fluid with hydrogen mantle domains has been simulated in an experiment at 7.8 GPa and 1350°C. The synthesized fluid contains mainly aldehydes; lower amounts of ketones, alcohols, esters, and ethers; as well as noticeable amounts of isobutane and butane, alkenes, arenes, and polycyclic aromatic and heterocyclic hydrocarbons. The fluid is compositionally close to volatiles found in inclusions from mantle olivines and picroilmenites.

Synthesis, structural, magnetic and optical properties of Sr2CoSn based inverse Heusler alloy nanoparticles

NASA Astrophysics Data System (ADS)

Asvini, V.; Saravanan, G.; Kalaiezhily, R. K.; Ravichandran, K.

2018-05-01

The peculiar ternary full Heusler alloy Sr2CoSn nanoparticles are synthesized by co-precipitation method. X- ray diffraction pattern confirms the formation of XA or Xα structure of Sr2CoSn. Using Williamson-Hall plot (W-H plot), we are able to use the uniform deformation model and get low value of strain induced broadening. UV-Visible absorption spectrum shows sharp absorption peak at 210 nm and the estimated band gap energy of Sr2CoSn Heusler alloy nanoparticles is Eg = 4.6 eV (from Tauc plot). The presence of Sr2CoSn with the particle size of approximately 90 nm was observed using high resolution scanning electron microscopy. The magnetization measurements were carried out using VSM and studied M verses H hysteresis studies.

50 Div in Normandy: A Critical Analysis of the British 50th (Northumbrian) Division on D-Day and in the Battle of Normandy

DTIC Science & Technology

2007-12-14

University Press, 1997), 90-92. 5House, 47-48. 6Kier, 89-90. 7Brian Bond and Williamson Murray, The British Armed Forces, 1918-39 in Allan R. Millet ...Figure 5. The German Defenses on June 6, 1944. nage, Jean -Pierre Benamou, BSource: Georges Ber ernard Crochet, François de Lannoy, Laurent Mari, and...Murray, “British Military Effectiveness in the Second World War” Military Effectiveness, Vol. 3, ed. Allan R. Millet and Williamson Murray (Boston

Synthesis and application of a natural plasticizer based on cardanol for poly(vinyl chloride)

USDA-ARS?s Scientific Manuscript database

A natural plasticizer with multifunctional groups, similar in structure to phthalates, cardanol derivatives glycidyl ether (CGE) was synthesized from cardanol by a two-step modification process and characterized by FT-IR, 1-HNMR, and 13-CNMR. The resulting product was incorporated to PVC (CGE/PVC), ...

A Cycloaromatization Protocol for Synthesis of Polysubstituted Phenol Derivatives: Method Development and Mechanistic Studies

PubMed Central

Spencer, William T.

2012-01-01

The scope of the cycloaromatization of propargylic ethers was explored using operationally simple air- and moisture-insensitive conditions. Highly substituted phenol derivatives were obtained in high yields. Mechanistic experiments indicate that the reaction occurs by an electrocyclization followed by 1,3-proton transfer. PMID:22891882

Synthesis of the Strychnos Alkaloid (-)-Strychnopivotine and Confirmation of its Absolute Configuration.

PubMed

Maertens, Gaëtan; Canesi, Sylvain

2016-05-17

The first enantioselective synthesis of (-)-strychnopivotine from a known and inexpensive phenol has been achieved in 15 steps. The strategy is based on a new diastereoselective aza-Michael-enol-ether cascade desymmetrization of a dienone, guided by a removable lactic acid-derived chiral auxiliary. Synthesis involves a phenol dearomatization, a conjugated silicon addition, a stereoselective double reductive amination, and two Heck-type carbopalladations as key steps. The absolute configuration of the natural compound, which, to date, has been uncertain, was confirmed by using circular dichroism (CD) spectroscopy and X-ray analyses. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

2-Methyltetrahydrofuran and cyclopentyl methyl ether for green solid-phase peptide synthesis.

PubMed

Jad, Yahya E; Acosta, Gerardo A; Khattab, Sherine N; de la Torre, Beatriz G; Govender, Thavendran; Kruger, Hendrik G; El-Faham, Ayman; Albericio, Fernando

2016-02-01

2-MeTHF and CPME were evaluated as greener alternatives for the most employed solvents in peptide synthesis. The ability of these solvents to dissolve amino acid derivatives and a range of coupling reagents were evaluated as well as the swelling of polystyrene and polyethylene glycol resins. In addition, racemization and coupling efficiencies were also determined. We concluded that the use of 2-MeTHF with combination of DIC/OxymaPure gave the lowest racemization level during stepwise synthesis of Z-Phg-Pro-NH2 and the highest purity during SPPS of Aib-enkephalin pentapeptide (H-Tyr-Aib-Aib-Phe-Leu-NH2).

Free-radical mediated synthesis of enantiomerically pure, highly functionalized inositols from carbohydrates.

PubMed

Marco-Contelles, J; Pozuelo, C; de Opazo, E

2001-06-15

We report the synthesis, free-radical cyclization of precursors 1,2,7-trideoxy-7-iodo-3,4:5,6-di-O-isopropylidene-D-gluco-hept-1-enitol (1), methyl 7-O-acetyl-6-O-benzyl-8-bromo-2,3,8-trideoxy-4,5-O-isopropylidene-D-gluco-oct-2-enonate (2) and 5-O-acetyl-4-O-benzyl-6-bromo-6-deoxy-2,3-O-isopropylidene-D-glucose-O-benzyloxime (3), readily prepared from D-glucose, and some selected transformations of the carbocycles obtained from these intermediates. In compound 1 we have installed a terminal double bond and an iodide as radical acceptor and leaving group, respectively. Compounds 2 and 3 are epsilon-bromo aldehydes substituted with alpha,beta-unsaturated ester and oxime ether functions as radical traps, respectively. The tributyltin hydride mediated ring closure of these radical precursors have afforded a series of interesting, diverse and highly functionalized carbocycles which can be considered useful building blocks for the synthesis of branched-chain cyclitols, aminocyclitols and aminoconduritols. In these processes, a good chemical yield and high stereoselectivity has been found in the newly formed stereocenters. Particularly interesting has been the finding that the stereochemical outcome of the free-radical cyclization is independent of the ratio of isomers (E or Z) in oxime ether 3. These results show the power and the state of art of this strategy for the stereocontrolled synthesis of enantiomerically pure inositols from carbohydrates.

Reductive Etherification of Fatty Acids or Esters with Alcohols using Molecular Hydrogen.

PubMed

Erb, Benjamin; Risto, Eugen; Wendling, Timo; Gooßen, Lukas J

2016-06-22

In the presence of a catalyst system consisting of a ruthenium/triphos complex and the Brønsted acid trifluoromethanesulfonimide, mixtures of fatty acids and aliphatic alcohols are converted into the corresponding ethers at 70 bar H2 . The protocol allows the sustainable one-step synthesis of valuable long-chain ether fragrances, lubricants, and surfactants from renewable sources. The reaction protocol is extended to various fatty acids and esters both in pure form and as mixtures, for example, tall oil acids or rapeseed methyl ester (RME). Even the mixed triglyceride rapeseed oil was converted in one step. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New biphasic solvent system based on cyclopentyl methyl ether for the purification of a non-polar synthetic peptide by pH-zone refining centrifugal partition chromatography.

PubMed

Amarouche, Nassima; Boudesocque, Leslie; Borie, Nicolas; Giraud, Matthieu; Forni, Luciano; Butte, Alessandro; Edwards, Florence; Renault, Jean-Hugues

2014-06-01

A new type 1 ternary biphasic system composed of cyclopentyl methyl ether, dimethylformamide and water was developed, characterized and successfully used for the purification of a lipophilic, protected peptide by pH-zone refining centrifugal partition chromatography. The protected peptide is an 8-mer, key intermediate in bivalirudin (Angiomax®) synthesis and shows a very low solubility in the solvents usually used in liquid chromatography. All ionic groups, except the N-terminal end of the peptide, are protected by a benzyl group. The purification of this peptide was achieved with a purity of about 99.04% and a recovery of 94% using the new ternary biphasic system cyclopentyl methyl ether/dimethylformamide/water (49:40:11, v/v) in the descending pH-zone refining mode with triethylamine (28 mM) as the retainer and methanesulfonic acid (18 mM) as the eluter. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrochemical synthesis, characterisation and phytogenic properties of silver nanoparticles

NASA Astrophysics Data System (ADS)

Singaravelan, R.; Bangaru Sudarsan Alwar, S.

2015-12-01

This work exemplifies a simple and rapid method for the synthesis of silver nanodendrite with a novel electrochemical technique. The antibacterial activity of these silver nanoparticles (Ag NPs) against pathogenic bacteria was investigated along with the routine study of optical and spectral characterisation. The optical properties of the silver nanoparticles were characterised by diffuse reflectance spectroscopy. The optical band gap energy of the electrodeposited Ag NPs was determined from the diffuse reflectance using Kubelka-Munk formula. X-ray diffraction (XRD) studies were carried out to determine the crystalline nature of the silver nanoparticles which confirmed the formation of silver nanocrystals. The XRD pattern revealed that the electrodeposited Ag NPs were in the cubic geometry with dendrite preponderance. The average particle size and the peak broadening were deliberated using Debye-Scherrer equation and lattice strain due to the peak broadening was studied using Williamson-Hall method. Surface morphology of the Ag NPs was characterised by high-resolution scanning electron microscope and the results showed the high degree of aggregation in the particles. The antibacterial activity of the Ag NPs was evaluated and showed unprecedented level antibacterial activity against multidrug resistant strains such as Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia and Escherichia coli in combination with Streptomycin.

A New Synthesis of Tertiary Alkyl N-Arylcarbamates from Isocyanates.

ERIC Educational Resources Information Center

Bailey, William J.; Griffith, James R.

1978-01-01

The method involves the dissolution of a small piece of metallic lithium in a small quantity of tertiary alcohol followed by addition to a mixture of the isocyanate and the tertiary alcohol in ether. This should be useful in organic chemistry laboratory courses for the identification of tertiary alcohols. (Author/BB)

Cylindol A, a novel biphenyl ether with 5-lipoxygenase inhibitory activity, and a related compound from Imperata Cylindrica.

PubMed

Matsunaga, K; Ikeda, M; Shibuya, M; Ohizumi, Y

1994-09-01

Cylindol A [1] and B [2], two novel substances, have been isolated from Imperata cylindrica, and their structures have been elucidated on the basis of their spectral data coupled with chemical evidence and total synthesis. Cylindol A [1] showed 5-lipoxygenase inhibitory activity.

Effects of Hurricane Katrina-Related Levee Failures on Wetland Sediments

DTIC Science & Technology

2008-09-01

80-84 209 1 Non-detects in IPET study and synthesis of USEPA data were handled by taking ½ reporting limit. 2 Presley et al. (2006) report geometric...2,2’-oxybis( 1 - Chloropropane ) 4,6-Dinitro-2- methylphenol Hexachlorobenzene 2,4,6-Trichlorophenol 4-Bromophenyl phenyl ether Hexachlorobutadiene...viii 1 Introduction

Process for synthesis of beryllium chloride dietherate

DOEpatents

Bergeron, Charles; Bullard, John E.; Morgan, Evan

1991-01-01

A low temperature method of producing beryllium chloride dietherate through the addition of hydrogen chloride gas to a mixture of beryllium metal in ether in a reaction vessel is described. A reflux condenser provides an exit for hydrogen produced form the reaction. A distillation condenser later replaces the reflux condenser for purifying the resultant product.

Synthesis, characterization, and sol-gel entrapment of a crown ether-styryl fluoroionophore

PubMed Central

Sui, Zhijie; Hanan, Nathan J.; Phimphivong, Sam; Wysocki, Ronald J.; Saavedra, S. Scott

2011-01-01

The synthesis and initial evaluation of a new dye-functionalized crown-ether, 2-[2-(2,3,5,6,8,9,11,12,14,15-decahydro-1,4,7,10.13.16-benzohexaoxacyclooctadecin)ethenyl]-3-methyl benzothiazolium iodide (denoted BSD), is reported. This molecule contains a benzyl 18-crown-6 moiety as the ionophore and a benzothiazolium to spectrally transduce ion binding. Binding of K+ to BSD in methanol causes shifts in the both absorbance and fluorescence emission maxima, as well as changes in the molar absorptivity and the emission intensity. Apparent dissociation constants (Kd) in the range of 30 – 65 μM were measured. In water and neutral buffer, Kd values were approximately 1 mM. BSD was entrapped in sol-gel films composed of methyltriethoxysilane (MTES) and tetraethylorthosilicate (TEOS) with retention of its spectral properties and minimal leaching. K+ binding to BSD in sol-gels films immersed in pH 7.4 buffer causes significant fluorescence quenching, with an apparent response time of approximately 2 min and an apparent Kd of 1.5 mM. PMID:19253273

DOE Office of Scientific and Technical Information (OSTI.GOV)

Underwood, R.P.

As part of the DOE-sponsored contract Synthesis of Dimethyl Ether and Alternative Fuels in the Liquid Phase from Coal-Derived Syngas'' experimental evaluations of the one-step synthesis of alternative fuels were carried out. The objective of this work was to develop novel processes for converting coal-derived syngas to fuels or fuel additives. Building on a technology base acquired during the development of the Liquid Phase Methanol (LPMEOH) process, this work focused on the development of slurry reactor based processes. The experimental investigations, which involved bench-scale reactor studies, focused primarily on three areas: (1) One-step, slurry-phase syngas conversion to hydrocarbons or methanol/hydrocarbonmore » mixtures using a mixture of methanol synthesis catalyst and methanol conversion catalyst in the same slurry reactor. (2) Slurry-phase conversion of syngas to mixed alcohols using various catalysts. (3) One-step, slurry-phase syngas conversion to mixed ethers using a mixture of mixed alcohols synthesis catalyst and dehydration catalyst in the same slurry reactor. The experimental results indicate that, of the three types of processes investigated, slurry phase conversion of syngas to mixed alcohols shows the most promise for further process development. Evaluations of various mixed alcohols catalysts show that a cesium-promoted Cu/ZnO/Al[sub 2]O[sub 3] methanol synthesis catalyst, developed in Air Products' laboratories, has the highest performance in terms of rate and selectivity for C[sub 2+]-alcohols. In fact, once-through conversion at industrially practical reaction conditions yielded a mixed alcohols product potentially suitable for direct gasoline blending. Moreover, an additional attractive aspect of this catalyst is its high selectivity for branched alcohols, potential precursors to iso-olefins for use in etherification.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Underwood, R.P.

As part of the DOE-sponsored contract ``Synthesis of Dimethyl Ether and Alternative Fuels in the Liquid Phase from Coal-Derived Syngas`` experimental evaluations of the one-step synthesis of alternative fuels were carried out. The objective of this work was to develop novel processes for converting coal-derived syngas to fuels or fuel additives. Building on a technology base acquired during the development of the Liquid Phase Methanol (LPMEOH) process, this work focused on the development of slurry reactor based processes. The experimental investigations, which involved bench-scale reactor studies, focused primarily on three areas: (1) One-step, slurry-phase syngas conversion to hydrocarbons or methanol/hydrocarbonmore » mixtures using a mixture of methanol synthesis catalyst and methanol conversion catalyst in the same slurry reactor. (2) Slurry-phase conversion of syngas to mixed alcohols using various catalysts. (3) One-step, slurry-phase syngas conversion to mixed ethers using a mixture of mixed alcohols synthesis catalyst and dehydration catalyst in the same slurry reactor. The experimental results indicate that, of the three types of processes investigated, slurry phase conversion of syngas to mixed alcohols shows the most promise for further process development. Evaluations of various mixed alcohols catalysts show that a cesium-promoted Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst, developed in Air Products` laboratories, has the highest performance in terms of rate and selectivity for C{sub 2+}-alcohols. In fact, once-through conversion at industrially practical reaction conditions yielded a mixed alcohols product potentially suitable for direct gasoline blending. Moreover, an additional attractive aspect of this catalyst is its high selectivity for branched alcohols, potential precursors to iso-olefins for use in etherification.« less

Nickel-Catalyzed Phosphine Free Direct N-Alkylation of Amides with Alcohols.

PubMed

Das, Jagadish; Banerjee, Debasis

2018-03-16

Herein, we developed an operational simple, practical, and selective Ni-catalyzed synthesis of secondary amides. Application of renewable alcohols, earth-abundant and nonprecious nickel catalyst facilitates the transformations, releasing water as byproduct. The catalytic system is tolerant to a variety of functional groups including nitrile, allylic ether, and alkene and could be extended to the synthesis of bis-amide, antiemetic drug Tigan, and dopamine D2 receptor antagonist Itopride. Preliminary mechanistic studies revealed the participation of a benzylic C-H bond in the rate-determining step.

Synthesis, characterization and cells and tissues imaging of carbon quantum dots

NASA Astrophysics Data System (ADS)

Wang, Jing; Li, Qilong; Zhou, JingE.; Wang, Yiting; Yu, Lei; Peng, Hui; Zhu, Jianzhong

2017-10-01

Compare to other quantum dots, carbon quantum dots have its own incomparable advantages, such as low cell toxicity, favorable biocompatibility, cheap production cost, mild reaction conditions, easy to large-scale synthesis and functionalization. In this thesis, we took citric acid monohydrate and diethylene glycol bis (3-aMinopropyl) ether as materials, used decomposition method to acquire carbon quantum dots (CQDs) which can emission blue fluorescence under ultraviolet excitation. In the aspect of application, we achieved the biological imaging of CQDs in vivo and in vitro.

Structural and dielectric properties of Al x Zn1- x O ( x = 0, 0.02, 0.04, 0.06, 0.08 and 0.10) nanoparticles

NASA Astrophysics Data System (ADS)

Sharma, Neha; Kumar, Sanjay; Sharma, Varun

2018-05-01

The chemical precipitation method is followed for the synthesis of Al-doped ZnO nanoparticles (NPs) with varying doping concentrations (0, 0.02, 0.04, 0.06, 0.08, and 0.10 M). A single hexagonal crystalline phase of wurtzite structure has been confirmed for all the samples by X-ray diffraction. Crystalline size and microstrain of the un-doped and doped ZnO (NPs) is determined by the Williamson-Hall (W-H) analysis. The optical properties like band gap and Urbach energy are found out by the UV-visible spectroscopy. The functional bonds are detailed by Fourier transmission infrared spectroscopy. The dielectric properties have been shown by doped sample due to hopping mechanisms as compared to the undoped. The loss factor (tan δ) follows an inverse direction as correspond to frequency due to the presence of dielectric dispersion.

Semisynthetic Phenol Derivatives Obtained from Natural Phenols: Antimicrobial Activity and Molecular Properties.

PubMed

Pinheiro, Patrícia Fontes; Menini, Luciana Alves Parreira; Bernardes, Patrícia Campos; Saraiva, Sérgio Henriques; Carneiro, José Walkimar Mesquita; Costa, Adilson Vidal; Arruda, Társila Rodrigues; Lage, Mateus Ribeiro; Gonçalves, Patrícia Martins; Bernardes, Carolina de Oliveira; Alvarenga, Elson Santiago; Menini, Luciano

2018-01-10

Semisynthetic phenol derivatives were obtained from the natural phenols: thymol, carvacrol, eugenol, and guaiacol through catalytic oxychlorination, Williamson synthesis, and aromatic Claisen rearrangement. The compounds characterization was carried out by 1 H NMR, 13 C NMR, and mass spectrometry. The natural phenols and their semisynthetic derivatives were tested for their antimicrobial activity against the bacteria: Staphylococcus aureus, Escherichia coli, Listeria innocua, Pseudomonas aeruginosa, Salmonella enterica Typhimurium, Salmonella enterica ssp. enterica, and Bacillus cereus. Minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were determined using concentrations from 220 to 3.44 μg mL -1 . Most of the tested compounds presented MIC values ≤220 μg mL -1 for all the bacteria used in the assays. The molecular properties of the compounds were computed with the PM6 method. Through principle components analysis, the natural phenols and their semisynthetic derivatives with higher antimicrobial potential were grouped.

Total syntheses of hyperforin and papuaforins A-C, and formal synthesis of nemorosone through a gold(I)-catalyzed carbocyclization.

PubMed

Bellavance, Gabriel; Barriault, Louis

2014-06-23

The remarkable biological activities of polyprenylated polycyclic acylphloroglucinols (PPAPs) combined with their highly decorated bicyclo[3.3.1]nonane-2,4,9-trione frameworks have inspired synthetic organic chemists over the last decade. The concise total syntheses of four natural products PPAPs; hyperforin and papuaforins A-C, and the formal synthesis of nemorosone are reported. Key to the realization of this strategy is the short and scalable synthesis of densely substituted PPAP scaffolds through a gold(I)-catalyzed 6-endo-dig carbocyclization of cyclic enol ethers for late-stage functionalization. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Distribution and condition of larval and juvenile Lost River and shortnose suckers in the Williamson River Delta restoration project and Upper Klamath Lake, Oregon

USGS Publications Warehouse

Burdick, Summer M.

2012-01-01

Federally endangered Lost River sucker (Deltistes luxatus) and shortnose sucker (Chasmistes brevirostris) were once abundant throughout their range but populations have declined. They were extirpated from several lakes in the 1920s and may no longer reproduce in other lakes. Poor recruitment to the adult spawning populations is one of several reasons cited for the decline and lack of recovery of these species and may be the consequence of high mortality during juvenile life stages. High larval and juvenile sucker mortality may be exacerbated by an insufficient quantity of suitable or high-quality rearing habitat. In addition, larval suckers may be swept downstream from suitable rearing areas in Upper Klamath Lake into Keno Reservoir, where they are assumed lost to Upper Klamath Lake populations. The Nature Conservancy flooded about 3,600 acres (1,456 hectares) to the north of the Williamson River mouth (Tulana) in October 2007, and about 1,400 acres (567 hectares) to the south and east of the Williamson River mouth (Goose Bay Farms) in October 2008, in order to retain larval suckers in Upper Klamath Lake, create nursery habitat, and improve water quality. The U.S. Geological Survey joined a long-term research and monitoring program in collaboration with The Nature Conservancy, the Bureau of Reclamation, and Oregon State University in 2008 to assess the effects of the Williamson River Delta restoration on the early life-history stages of Lost River and shortnose suckers. The primary objectives of the research were to describe habitat colonization and use by larval and juvenile suckers and non-sucker fishes and to evaluate the effects of the restored habitat on the health and condition of juvenile suckers. This report summarizes data collected in 2010 by the U.S. Geological Survey as a part of this monitoring effort and follows two annual reports on data collected in 2008 and 2009. Restoration modifications made to the Williamson River Delta appeared to provide additional suitable rearing habitat for endangered Lost River and shortnose suckers from 2008 to 2010 based on sucker catches. Mean larval sample density was greater for both species in the Williamson River Delta than adjacent lake habitats in all 3 years. In addition to larval suckers, at least three age classes of juvenile suckers were captured in the delta. The shallow Goose Bay Farms and Tulana Emergent were among the most used habitats by age-0 suckers in 2009. Both of these environments became inaccessible due to low water in 2010, however, and were not sampled after July 19, 2010. In contrast, age-1 sucker catches shifted from the shallow water (about 0.5-1.5 m deep) on the eastern side of the Williamson River Delta in May, to deeper water environments (greater than 2 m) by the end of June or early July in all 3 years. Differential distribution among sucker species within the Williamson River Delta and between the delta and adjacent lakes indicated that shortnose suckers likely benefited more from the restored Williamson River Delta than Lost River or Klamath largescale suckers (Catostomus snyderi). Catch rates in shallow-water habitats within the delta were higher for shortnose and Klamath largescale sucker larvae than for larval Lost River suckers in 2008, 2009, and 2010. Shortnose suckers also comprised the greatest portion of age-0 suckers captured in the Williamson River Delta in all 3 years of the study. The relative abundance of age-1 shortnose suckers was high in our catches compared to age-1 Lost River suckers in 2009 and 2010. The restored delta also created habitat for several piscivorous fishes, but only two appeared to pose a meaningful threat of predation to suckers - fathead minnows (Pimephales promelas) and yellow perch (Perca flavescens). Fathead minnows that prey on larval but not juvenile suckers dominated catches in all sampling areas. Yellow perch also were abundant throughout the study area, but based on their gape size and co-occurrence with suckers, most were only capable of preying on larvae. Low May lake-surface elevation, below average snow pack, and anticipated irrigation demands indicated late summer water levels in Upper Klamath Lake would be unusually low in 2010. In response to concerns by the Fish and Wildlife Service and The Nature Conservancy that low-water conditions might strand fish on the delta, low water seine surveys were implemented. Eleven fishes, including both endangered suckers, were captured in seine surveys, including both species of suckers, which continued to use shallow water less than 0.4 m deep through September 21. Lake elevation declined to 1,261.54 m (4,138.9 feet) in mid-September 2010, but did not appear to strand fish or cause large-scale fish mortality.

Using Field Data and GIS-Derived Variables to Model Occurrence of Williamson's Sapsucker Nesting Habitat at Multiple Spatial Scales.

PubMed

Drever, Mark C; Gyug, Les W; Nielsen, Jennifer; Stuart-Smith, A Kari; Ohanjanian, I Penny; Martin, Kathy

2015-01-01

Williamson's sapsucker (Sphyrapicus thyroideus) is a migratory woodpecker that breeds in mixed coniferous forests in western North America. In Canada, the range of this woodpecker is restricted to three small populations in southern British Columbia, precipitating a national listing as 'Endangered' in 2005, and the need to characterize critical habitat for its survival and recovery. We compared habitat attributes between Williamson's sapsucker nest territories and random points without nests or detections of this sapsucker as part of a resource selection analysis to identify the habitat features that best explain the probability of nest occurrence in two separate geographic regions in British Columbia. We compared the relative explanatory power of generalized linear models based on field-derived and Geographic Information System (GIS) data within both a 225 m and 800 m radius of a nest or random point. The model based on field-derived variables explained the most variation in nest occurrence in the Okanagan-East Kootenay Region, whereas nest occurrence was best explained by GIS information at the 800 m scale in the Western Region. Probability of nest occurrence was strongly tied to densities of potential nest trees, which included open forests with very large (diameter at breast height, DBH, ≥57.5 cm) western larch (Larix occidentalis) trees in the Okanagan-East Kootenay Region, and very large ponderosa pine (Pinus ponderosa) and large (DBH 17.5-57.5 cm) trembling aspen (Populus tremuloides) trees in the Western Region. Our results have the potential to guide identification and protection of critical habitat as required by the Species at Risk Act in Canada, and to better manage Williamson's sapsucker habitat overall in North America. In particular, management should focus on the maintenance and recruitment of very large western larch and ponderosa pine trees.

Stability of a Bifunctional Cu-Based Core@Zeolite Shell Catalyst for Dimethyl Ether Synthesis Under Redox Conditions Studied by Environmental Transmission Electron Microscopy and In Situ X-Ray Ptychography.

PubMed

Baier, Sina; Damsgaard, Christian D; Klumpp, Michael; Reinhardt, Juliane; Sheppard, Thomas; Balogh, Zoltan; Kasama, Takeshi; Benzi, Federico; Wagner, Jakob B; Schwieger, Wilhelm; Schroer, Christian G; Grunwaldt, Jan-Dierk

2017-06-01

When using bifunctional core@shell catalysts, the stability of both the shell and core-shell interface is crucial for catalytic applications. In the present study, we elucidate the stability of a CuO/ZnO/Al2O3@ZSM-5 core@shell material, used for one-stage synthesis of dimethyl ether from synthesis gas. The catalyst stability was studied in a hierarchical manner by complementary environmental transmission electron microscopy (ETEM), scanning electron microscopy (SEM) and in situ hard X-ray ptychography with a specially designed in situ cell. Both reductive activation and reoxidation were applied. The core-shell interface was found to be stable during reducing and oxidizing treatment at 250°C as observed by ETEM and in situ X-ray ptychography, although strong changes occurred in the core on a 10 nm scale due to the reduction of copper oxide to metallic copper particles. At 350°C, in situ X-ray ptychography indicated the occurrence of structural changes also on the µm scale, i.e. the core material and parts of the shell undergo restructuring. Nevertheless, the crucial core-shell interface required for full bifunctionality appeared to remain stable. This study demonstrates the potential of these correlative in situ microscopy techniques for hierarchically designed catalysts.

Synthesis of Improved Antileishmanial and Antitrypanosomal Drugs Treatment and Prophylaxis

DTIC Science & Technology

1986-11-01

for a diphenyl ether analog ((2) p. 44). 16 - -r , ü$$m&±ysc$c .<v£*^Ä VV’-Orfs aB9*>ratfe>^v CHART NO. 1 8-[(6-AMIDOXIMINOHEXYL)AMINO]-6-METHOXY...MALEATE (SNL-130) cico—(f)V-ci A1C1 CS 1 (58%) • Brü 1) »3PCH2CH2NMe2/n-BuLi 2) H30* 3) Oxalic Acid 4) OH 0 «CHCH,NMe 2ŕ,c2 2 (79%), Free base... diphenyl ether analog ((2) p. 44). A mixture of sodium amide (11.6 g, O.J mol), acetonitrile (15 mL, 11.8 g> 0.29 mol) and dry benzene (1 L) was heated

Study of magnetization switching for MRAM based memory technologies

NASA Astrophysics Data System (ADS)

Pham, Huy

Amphibian alkaloids are attractive targets for synthesis due to their biological activity. An important class of amphibian alkaloids is the 2,5-disubstituted pyrrolidine-based family of compounds. There are many synthetic approaches for the preparation of the trans-2,5-disubstituted pyrrolidines, but methods for the construction of the cis-2,5-pyrrolidines are limited. Therefore, it was desired to develop an enantioselective approach for the preparation of cis-2,5-disubsituted pyrrolidines. (+)-Tropin-2-one derived from cocaine was used as starting material to exploit the inherent stereochemistry for construction of the cis-pyrrolidine ring. This permitted the unequivocal assignment of the absolute configuration of the target pyrrolidine. The structurally simple pyrrolidine alkaloid, 225H, was selected as a target to develop a general synthetic approach. The enantioselective synthesis of 225H was achieved in nine steps and good overall yield. The search for potent cannabinoid receptor partial agonist ligands as potential marijuana addiction therapeutic agents has led to an investigation of the synthesis of diaryl ether hybrid analogues of BAY 59-3074. A series of 2-(3-alkyl-5-hydroxyphenoxy)-6-(trifluoromethyl)benzonitriles, 3-(2-cyano-3-(trifluoromethyl)phenoxy)phenylalkanoates, and (3-(benzyloxy)phenoxy)-6-(trifluoromethyl)benzonitriles were synthesized and evaluated in vitro for CB1 affinity. The olivetol diaryl ether analogue was the most potent ligand of the alkyl series, but the diaryl ester analogues exhibited modest affinity for CB1 receptors. The most potent compound of the series was the 2-(3-(benzyloxy)phenoxy)-6-(trifluoromethyl)benzonitrile. Keywords. amphibian alkaloids, enantioselective synthesis, pyrrolidine, cannabinoid receptor, marijuana.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, C H

The chemistry of the various types of reactions possible between a carboxyl-terminated butadiene/acrylonitrile (CBTN) liquid copolymer and a diglycidyl ether of bisphenol A (DGEBA) type epoxy resin to prepare a CTBN/DGEBA adduct is discussed. Both a dilution and a non-dilution synthesis techniqu are described. Several properties of the CTBN precursor and the modified epoxy resin were determined and are presented.

Gold (III) Chloride-Catalyzed 6-endo-trig Oxa-Michael Addition Reactions for Diastereoselective Synthesis of Fused Tetrahydropyranones

PubMed Central

Ciesielski, Jennifer; Lebœuf, David; Stern, Harry A.

2013-01-01

Alkynones were treated with boron trifluoride diethyl etherate to generate β-iodoallenolates, which underwent intramolecular aldol reactions to produce cycloalkenyl alcohols. Diastereoselective oxa-Michael ring closure could then be induced by treatment with a catalytic amount of gold(III) chloride, affording highly functionalized tetrahydropyran-containing ring systems. PMID:24032002

A novel biobased plasticizer of epoxidized cardanol glycidylether: Synthesis and application in soft poly(vinyl chloride) films

USDA-ARS?s Scientific Manuscript database

A novel plasticizer derived from cardanol, epoxied cardanol glycidyl ether (ECGE), was synthesized and characterized by 1H-NMR and 13C-NMR. Effects of the ECGE combined with dioctyl phthalate (DOP), a commercial plasticizer, in soft poly(vinyl chloride) (PVC) films were studied. Dynamic mechanical a...

Cs₂CO₃-Initiated Trifluoro-Methylation of Chalcones and Ketones for Practical Synthesis of Trifluoromethylated Tertiary Silyl Ethers.

PubMed

Dong, Cheng; Bai, Xing-Feng; Lv, Ji-Yuan; Cui, Yu-Ming; Cao, Jian; Zheng, Zhan-Jiang; Xu, Li-Wen

2017-05-18

It was found that 1,2-trifluoromethylation reactions of ketones, enones, and aldehydes were easily accomplished using the Prakash reagent in the presence of catalytic amounts of cesium carbonate, which represents an experimentally convenient, atom-economic process for this anionic trifluoromethylation of non-enolisable aldehydes and ketones.

Patterns of larval sucker emigration from the Sprague and lower Williamson Rivers of the Upper Klamath Basin, Oregon, after the removal of Chiloquin Dam - 2009-10 Annual Report

USGS Publications Warehouse

Ellsworth, Craig M.; Martin, Barbara A.

2012-01-01

Data presented in this report is a continuation of a research project that began in 2004. Larval drift parameters measured in 2009 and 2010 were similar to those measured from 2004 to 2008. Most larvae and eggs were collected at the two drift sites downstream of the former Chiloquin Dam (river kilometer 0.7 on the Sprague River and river kilometer 7.4 on the Williamson River). Mean and peak sample densities increased with proximity to Upper Klamath Lake. Peak larval densities continued to be collected between 1 and 3 hours after sunset at Chiloquin, which is the drift site nearest a known spawning area. Catch distribution of larvae and eggs in the lower Sprague and Williamson Rivers suggests that most SNS and LRS spawning continues to occur downstream of the site of the former Chiloquin Dam. The sizes and growth stages indicate that larval emigration from spawning areas resulting from drift occurs within a few days after swim-up. Larval suckers appear to move downstream quickly until they reach suitable rearing habitat.

[Au]/[Ag]-catalysed expedient synthesis of branched heneicosafuranosyl arabinogalactan motif of Mycobacterium tuberculosis cell wall

NASA Astrophysics Data System (ADS)

Thadke, Shivaji A.; Mishra, Bijoyananda; Islam, Maidul; Pasari, Sandip; Manmode, Sujit; Rao, Boddu Venkateswara; Neralkar, Mahesh; Shinde, Ganesh P.; Walke, Gulab; Hotha, Srinivas

2017-01-01

Emergence of multidrug-resistant and extreme-drug-resistant strains of Mycobacterium tuberculosis (MTb) can cause serious socioeconomic burdens. Arabinogalactan present on the cellular envelope of MTb is unique and is required for its survival; access to arabinogalactan is essential for understanding the biosynthetic machinery that assembles it. Isolation from Nature is a herculean task and, as a result, chemical synthesis is the most sought after technique. Here we report a convergent synthesis of branched heneicosafuranosyl arabinogalactan (HAG) of MTb. Key furanosylations are performed using [Au]/[Ag] catalysts. The synthesis of HAG is achieved by the repetitive use of three reactions namely 1,2-trans furanoside synthesis by propargyl 1,2-orthoester donors, unmasking of silyl ether, and conversion of n-pentenyl furanosides into 1,2-orthoesters. Synthesis of HAG is achieved in 47 steps (with an overall yield of 0.09%) of which 21 are installation of furanosidic linkages in a stereoselective manner.

Structure activity relationship of C-2 ether substituted 1,5-naphthyridine analogs of oxabicyclooctane-linked novel bacterial topoisomerase inhibitors as broad-spectrum antibacterial agents (Part-5).

PubMed

Singh, Sheo B; Kaelin, David E; Meinke, Peter T; Wu, Jin; Miesel, Lynn; Tan, Christopher M; Olsen, David B; Lagrutta, Armando; Fukuda, Hideyuki; Kishii, Ryuta; Takei, Masaya; Takeuchi, Tomoko; Takano, Hisashi; Ohata, Kohei; Kurasaki, Haruaki; Nishimura, Akinori; Shibata, Takeshi; Fukuda, Yasumichi

2015-09-01

Oxabicyclooctane linked novel bacterial topoisomerase inhibitors (NBTIs) are new class of recently reported broad-spectrum antibacterial agents. They target bacterial DNA gyrase and topoisomerase IV and bind to a site different than quinolones. They show no cross-resistance to known antibiotics and provide opportunity to combat drug-resistant bacteria. A structure activity relationship of the C-2 substituted ether analogs of 1,5-naphthyridine oxabicyclooctane-linked NBTIs are described. Synthesis and antibacterial activities of a total of 63 analogs have been summarized representing alkyl, cyclo alkyl, fluoro alkyl, hydroxy alkyl, amino alkyl, and carboxyl alkyl ethers. All compounds were tested against three key strains each of Gram-positive and Gram-negative bacteria as well as for hERG binding activities. Many key compounds were also tested for the functional hERG activity. Six compounds were evaluated for efficacy in a murine bacteremia model of Staphylococcus aureus infection. Significant tolerance for the ether substitution (including polar groups such as amino and carboxyl) at C-2 was observed for S. aureus activity however the same was not true for Enterococcus faecium and Gram-negative strains. Reduced clogD generally showed reduced hERG activity and improved in vivo efficacy but was generally associated with decreased overall potency. One of the best compounds was hydroxy propyl ether (16), which mainly retained the potency, spectrum and in vivo efficacy of AM8085 associated with the decreased hERG activity and improved physical property. Copyright © 2015 Elsevier Ltd. All rights reserved.

Formal synthesis of berkelic acid: a lesson in α-alkylation chemistry.

PubMed

McLeod, Michael C; Wilson, Zoe E; Brimble, Margaret A

2012-01-06

The full details of our enantioselective formal synthesis of the biologically active natural product berkelic acid are described. The insertion of the C-18 methyl group proved challenging, with three different approaches investigated to install the correct stereochemistry. Our initial Horner-Wadsworth-Emmons/oxa-Michael approach to the berkelic acid core proved unsuccessful upon translation to the natural product itself. However, addition of a silyl enol ether to an oxonium ion, followed by a one-pot debenzylation/spiroketalisation/thermodynamic equilibration procedure, afforded the tetracyclic structure of the berkelic acid core as a single diastereoisomer.

Fabrication of composite membranes using copper metal organic framework for energy application

NASA Astrophysics Data System (ADS)

Gahlot, Swati; Rajput, Abhishek; Kulshrestha, Vaibhav

2018-04-01

Present manuscript deals with the synthesis of nanocomposite polymer electrolyte membrane (PEM) based on copper based metal organic framework (Cu-MOF) and sulfonated poly ether sulfone (SPES) for fuel cell application. Prepared material and composite membrane has been analyzed through various techniques. Structural and thermal characterization of prepared material has been carried out through XRD, FTIR and TGA technique. Measurement shows the successful synthesis of MOF and also confirms the thermal stability. Prepared membranes shows good physicochemical properties and good ionic conductivity which can be utilized as PEM for fuel cell application.

Hydrodehalogenation of alkyl iodides with base-mediated hydrogenation and catalytic transfer hydrogenation: application to the asymmetric synthesis of N-protected α-methylamines.

PubMed

Mandal, Pijus K; Birtwistle, J Sanderson; McMurray, John S

2014-09-05

We report a very mild synthesis of N-protected α-methylamines from the corresponding amino acids. Carboxyl groups of amino acids are reduced to iodomethyl groups via hydroxymethyl intermediates. Reductive deiodination to methyl groups is achieved by hydrogenation or catalytic transfer hydrogenation under alkaline conditions. Basic hydrodehalogenation is selective for the iodomethyl group over hydrogenolysis-labile protecting groups, such as benzyloxycarbonyl, benzyl ester, benzyl ether, and 9-fluorenyloxymethyl, thus allowing the conversion of virtually any protected amino acid into the corresponding N-protected α-methylamine.

Hydrodehalogenation of Alkyl Iodides with Base-Mediated Hydrogenation and Catalytic Transfer Hydrogenation: Application to the Asymmetric Synthesis of N-Protected α-Methylamines

PubMed Central

2015-01-01

We report a very mild synthesis of N-protected α-methylamines from the corresponding amino acids. Carboxyl groups of amino acids are reduced to iodomethyl groups via hydroxymethyl intermediates. Reductive deiodination to methyl groups is achieved by hydrogenation or catalytic transfer hydrogenation under alkaline conditions. Basic hydrodehalogenation is selective for the iodomethyl group over hydrogenolysis-labile protecting groups, such as benzyloxycarbonyl, benzyl ester, benzyl ether, and 9-fluorenyloxymethyl, thus allowing the conversion of virtually any protected amino acid into the corresponding N-protected α-methylamine. PMID:25116734

Entropy Generation Minimization in Dimethyl Ether Synthesis: A Case Study

NASA Astrophysics Data System (ADS)

Kingston, Diego; Razzitte, Adrián César

2018-04-01

Entropy generation minimization is a method that helps improve the efficiency of real processes and devices. In this article, we study the entropy production (due to chemical reactions, heat exchange and friction) in a conventional reactor that synthesizes dimethyl ether and minimize it by modifying different operating variables of the reactor, such as composition, temperature and pressure, while aiming at a fixed production of dimethyl ether. Our results indicate that it is possible to reduce the entropy production rate by nearly 70 % and that, by changing only the inlet composition, it is possible to cut it by nearly 40 %, though this comes at the expense of greater dissipation due to heat transfer. We also study the alternative of coupling the reactor with another, where dehydrogenation of methylcyclohexane takes place. In that case, entropy generation can be reduced by 54 %, when pressure, temperature and inlet molar flows are varied. These examples show that entropy generation analysis can be a valuable tool in engineering design and applications aiming at process intensification and efficient operation of plant equipment.

Synthesis and structure-activity relationships of varied ether linker analogues of the antitubercular drug (6S)-2-nitro-6-{[4-(trifluoromethoxy)benzyl]oxy}-6,7-dihydro-5h-imidazo[2,1-b][1,3]oxazine (PA-824).

PubMed

Thompson, Andrew M; Sutherland, Hamish S; Palmer, Brian D; Kmentova, Iveta; Blaser, Adrian; Franzblau, Scott G; Wan, Baojie; Wang, Yuehong; Ma, Zhenkun; Denny, William A

2011-10-13

New analogues of antitubercular drug PA-824 were synthesized, featuring alternative side chain ether linkers of varying size and flexibility, seeking drug candidates with enhanced metabolic stability and high efficacy. Both α-methyl substitution and removal of the benzylic methylene were broadly tolerated in vitro, with a biaryl example of the latter class exhibiting an 8-fold better efficacy than the parent drug in a mouse model of acute Mycobacterium tuberculosis infection and negligible fragmentation to an alcohol metabolite in liver microsomes. Extended linkers (notably propenyloxy, propynyloxy, and pentynyloxy) provided greater potencies against replicating M. tb (monoaryl analogues), with propynyl ethers being most effective under anaerobic (nonreplicating) conditions (mono/biaryl analogues). For benzyloxybenzyl and biaryl derivatives, aerobic activity was maximal with the original (OCH(2)) linker. One propynyloxy-linked compound displayed an 89-fold higher efficacy than the parent drug in the acute model, and it was slightly superior to antitubercular drug OPC-67683 in a chronic infection model.

Novel Ordered Crown Ether-Containing Polyimides for Ion Conduction

NASA Technical Reports Server (NTRS)

Irvin, Jennifer A.; Stasko, Daniel; Fallis, Stephen; Guenthner, Andrew J.; Webber, Cynthia; Blackwell, John; Chvalun, Sergei N.

2003-01-01

We report the synthesis and characterization of thermally-stable polyimides for use as battery and fuel cell electrolyte membranes. Dianhydrides used were 1,4,5,8- naphthalenetetracarboxylic dianhydride and/or 4,4'-(hexafluoroisopropylidene)diphthalic anhydride. Diamines used were anti-4,4-diaminodibenzo-l8-crown-6, 4,4'- diaminodibenzo-24-crown-8, 2,2-bis(4-aminophenyl)hexafluoropropane, and/or 2,5- diaminobenzenesulfonic acid. The polymers were characterized using electrochemical impedance spectroscopy (EIS), thermal analysis and X-ray diffraction. Polymers containing the hexafluoroisopropylidene (HFIP) group were soluble in common organic solvents, while polymers without the HFIP group were very poorly soluble. Sulfonation yields polymers that are sparingly soluble in aqueous base and/or methanol. Degree of sulfonation, determined by titration, was between one and three sulfonate groups per repeat unit. Proton conductivity was determined as a function of water content, with a maximum conductivity of l x 10(exp -2) per centimeter when fully hydrated. Crown ether-containing polymers exhibit a high degree of order that may be indicative of crown ether channel formation, which may facilitate Li(+) transport for use in battery membranes.

Catalyst activity maintenance study for the liquid phase dimethyl ether process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, X.D.; Toseland, B.A.; Underwood, R.P.

1995-12-31

The co-production of dimethyl ether (DME) and methanol from syngas is a process of considerable commercial attractiveness. DME coproduction can double the productivity of a LPMEOH process when using coal-derived syngas. This in itself may offer chemical producers and power companies increased flexibility and more profitable operation. DME is also known as a clean burning liquid fuel; Amoco and Haldor-Topsoe have recently announced the use of DME as an alternative diesel fuel. Moreover, DME can be an interesting intermediate in the production of chemicals such as olefins and vinyl acetate. The current APCl liquid phase dimethyl ether (LPDME) process utilizesmore » a physical mixture of a commercial methanol synthesis catalyst and a dehydration catalyst (e.g., {gamma}-alumina). While this arrangement provides a synergy that results in much higher syngas conversion per pass compared to the methanol-only process, the stability of the catalyst system suffers. The present project is aimed at reducing catalyst deactivation both by understanding the cause(s) of catalyst deactivation and by developing modified catalyst systems. This paper describes the current understanding of the deactivation mechanism.« less

Synthesis of carboxylic acids, esters, alcohols and ethers containing a tetrahydropyran ring derived from 6-methyl-5-hepten-2-one.

PubMed

Hanzawa, Yohko; Hashimoto, Kahoko; Kasashima, Yoshio; Takahashi, Yoshiko; Mino, Takashi; Sakamoto, Masami; Fujita, Tsutomu

2012-01-01

3-hydroxy acids, 3-hydroxy-3,7-dimethyloct-6-enoic acid (1) and 3-hydroxy-2,2,3,7-tetramethyloct-6-enoic acid (2), were prepared from 6-methyl-5-hepten-2-one, and they were subsequently used to prepare (2,6,6-trimethyltetrahydropyran-2-yl)acetic acid (3) and 2-methyl-2-(2,6,6-trimethyltetrahydropyran-2-yl)propanoic acid (4), respectively, via cyclization with an acidic catalyst such as boron trifluoride diethyl etherate or iodine. The reaction of carboxylic acids 3 and 4 with alcohols, including methanol, ethanol, and 1-propanol, produced the corresponding methyl, ethyl, and propyl esters, which all contained a tetrahydropyran ring. Reduction of carboxylic acids 3 and 4 afforded the corresponding alcohols. Subsequent reactions of these alcohols with several acyl chlorides produced novel esters. The alcohols also reacted with methyl iodide and sodium hydride to provide novel ethers. A one-pot cyclization-esterification of 1 to produce esters containing a tetrahydropyran ring, using iodine as a catalyst, was also investigated.

Influence of the brewing process on furfuryl ethyl ether formation during beer aging.

PubMed

Vanderhaegen, Bart; Neven, Hedwig; Verstrepen, Kevin J; Delvaux, Freddy R; Verachtert, Hubert; Derdelinckx, Guy

2004-11-03

In beer, the development of a solvent-like stale flavor is associated with the formation of furfuryl ethyl ether. The synthesis rate of this important flavor compound is proportional to the concentration of furfuryl alcohol in beer. This study shows that furfuryl alcohol in beer is mainly formed by Maillard reactions initiated during wort boiling and malt production. A mechanism for its formation from alpha-(1,4)-oligoglucans and amino acids in wort and beer is proposed. During wort boiling, a quadratic relationship was found between the wort extract concentration, on the one hand, and the increase of furfuryl alcohol and furfural, on the other. The reduction of furfural by yeast during fermentation further increases the furfuryl alcohol content. In pale beers, the furfuryl alcohol concentration is essentially determined by the thermal load on wort during brewing operations. In dark beers, a considerable fraction of furfuryl alcohol may, however, come from the dark malts used. These results lead to important practical conclusions concerning the control over furfuryl ethyl ether in beer.

Using a Premade Grignard Reagent to Synthesize Tertiary Alcohols in a Convenient Investigative Organic Laboratory Experiment

ERIC Educational Resources Information Center

Berg, Michael A. G.; Pointer, Roy D.

2007-01-01

A commercially available Grignard reagent (3.0 M solution of phenyl magnesium bromide in ether) was used in a convenient Grignard synthesis in a second-year organic chemistry laboratory without any of the typical failures associated with the Grignard reaction. The reaction setup used oven-dried glassware and no extraordinary measures were taken to…

Synthesis and characterization of polyphosphazene electrolytes including cyclic ether side groups

NASA Astrophysics Data System (ADS)

Fiedler, Carsten; Luerssen, Bjoern; Lucht, Brett; Janek, Juergen

2018-04-01

This paper presents the synthesis and detailed characterization of two polyphosphazene based polymers, including different cyclic ether side groups. The final polymers were obtained by a well-known method employing a living cationic polymerization and subsequent nucleophilic substitution. The synthesized polymers Poly [(1,3-dioxane-5-oxy) (1,3-dioxolane-4-methoxy)phosphazene] (DOPP) and Poly[bis(2-Tetrahydro-3-furanoxy)phosphazene] (THFPP) were mixed with varied amounts of lithium bis(trifluoromethane)sulfonamide (LiTFSI) and the interactions between the salt and the polymer chains were studied by Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) measurements. Electrochemical characterization was performed by electrochemical impedance spectroscopy (EIS) and direct current polarization in the temperature range of 20-60 °C. These measurements were utilized to calculate the lithium transference number (t+), the lithium conductivity (σ) and its activation energy in order to elucidate the lithium transport behavior. Relatively high lithium transference numbers of 0.6 (DOPP) and 0.7 (THFPP) at 60 °C are found and reveal maximum lithium conductivities of 2.8·10-6 Sṡcm-1 and 9.0·10-7 Sṡcm-1 for DOPP and THFPP at 60 °C, respectively.

New monomers for high performance polymers

NASA Technical Reports Server (NTRS)

Gratz, Roy F.

1993-01-01

This laboratory has been concerned with the development of new polymeric materials with high thermo-oxidative stability for use in the aerospace and electronics industries. Currently, there is special emphasis on developing matrix resins and composites for the high speed civil transport (HSCT) program. This application requires polymers that have service lifetimes of 60,000 hr at 350 F (177 C) and that are readily processible into void-free composites, preferably by melt-flow or powder techniques that avoid the use of high boiling solvents. Recent work has focused on copolymers which have thermally stable imide groups separated by flexible arylene ether linkages, some with trifluoromethyl groups attached to the aromatic rings. The presence of trifluoromethyl groups in monomers and polymers often improves their solubility and processibility. The goal of this research was to synthesize several new monomers containing pendant trifluoromethyl groups and to incorporate these monomers into new imide/arylene ether copolymers. Initially, work was begun on the synthesis of three target compounds. The first two, 3,5-dihydroxybenzo trifluoride and 3-amino 5-hydroxybenzo trifluoride, are intermediates in the synthesis of more complex monomers. The third, 3,5-bis (3-amino-phenoxy) benzotrifluoride, is an interesting diamine that could be incorporated into a polyimide directly.

Recombinant human dihydroxyacetonephosphate acyl-transferase characterization as an integral monotopic membrane protein.

PubMed

Piano, Valentina; Nenci, Simone; Magnani, Francesca; Aliverti, Alessandro; Mattevi, Andrea

2016-12-02

Although the precise functions of ether phospholipids are still poorly understood, significant alterations in their physiological levels are associated either to inherited disorders or to aggressive metastatic cancer. The essential precursor, alkyl-dihydroxyacetone phosphate (DHAP), for all ether phospholipids species is synthetized in two consecutive reactions performed by two enzymes sitting on the inner side of the peroxisomal membrane. Here, we report the characterization of the recombinant human DHAP acyl-transferase, which performs the first step in alkyl-DHAP synthesis. By exploring several expression systems and designing a number of constructs, we were able to purify the enzyme in its active form and we found that it is tightly bound to the membrane through the N-terminal residues. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Polarity dependent photoisomerization of ether substituted azodyes: Synthesis and photoswitching behavior.

PubMed

Gan, Siew Mei; Pearl, Zynia Fernandes; Yuvaraj, A R; Lutfor, M R; Gurumurthy, Hegde

2015-10-05

Two new ether substituted azodyes were synthesized and characterized by different spectral analysis such as (1)H NMR, (13)C NMR, FTIR and UV/Vis. Synthesized compounds were used to study the photoisomerization phenomenon by using UV-Vis spectro-photometer. Interesting polarity dependent effect is observed for the first time on these materials. Trans-cis (E-Z) and cis-trans (Z-E) conversion occurred within 41 s and 445 min, respectively for both the compounds in solutions. Polarizing optical microscopy studies revealed that there is no liquid crystal phase for both the compounds. The dramatic variation in the optical property is speculated to be the polarity of the chemical species. These derivatives are useful to fabricate optical data storage devices. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and in vitro activity of dicationic indolyl diphenyl ethers as novel potent antibiotic agents against drug-resistant bacteria.

PubMed

Chen, Xiaofang; Hu, Xinxin; Wu, Yanbin; Liu, Yonghua; Bian, Cong; Nie, Tongying; You, Xuefu; Hu, Laixing

2017-02-15

A series of 4,4'-bis-[2-(6-N-substituted-amidino)indolyl] diphenyl ether have been synthesized and tested for their in vitro antibacterial activity including a range of Gram-positive and Gram-negative pathogens and cytotoxicity. Most of these compounds have mainly shown anti-Gram positive bacteria activities especially against drug resistant bacterial strains MRSA, MRSE and VRE. The anti-MRSA and anti-MRSE activities of compound 7a and 7j were more potent than that of the lead compound 2, levofloxacin and vancomycin. Interestingly, 7j had greatly improved anti negative bacterial activity, especially for the producing NDM-1 Klebsiella pneumonia strain and less toxic than that of the lead compound 2. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of the thermal stability of perfluoropolyalkyl ethers by tensimetry

NASA Technical Reports Server (NTRS)

Helmick, Larry A.; Jones, William R., Jr.

1992-01-01

The thermal decomposition temperatures of several perfluoropolyalkyl ether fluids were determined with a computerized tensimeter. In general, the decomposition temperatures of the commercial fluids were all similar and significantly higher than those for noncommercial fluids. Correlation of the decomposition temperatures with the molecular structures of the primary components of the commercial fluids revealed that the stability of the fluids was not affected by carbon chain length, branching, or adjacent difluoroformal groups. Instead, stability was limited by the presence of small quantities of thermally unstable material and/or chlorine-containing material arising from the use of chlorine containing solvents during synthesis. Finally, correlation of decomposition temperatures with molecular weights for two fluids supports a chain cleavage reaction mechanism for one and an unzipping reaction mechanism for the other.

Size-controlled synthesis of nanocrystalline CdSe thin films by inert gas condensation

NASA Astrophysics Data System (ADS)

Sharma, Jeewan; Singh, Randhir; Kumar, Akshay; Singh, Tejbir; Agrawal, Paras; Thakur, Anup

2018-02-01

Size, shape and structure are considered to have significant influence on various properties of semiconducting nanomaterials. Different properties of these materials can be tailored by controlling the size. Size-controlled CdSe crystallites ranging from ˜ 04 to 95 nm were deposited by inert gas-condensation technique (IGC). In IGC method, by controlling the inert gas pressure in the condensation chamber and the substrate temperature or both, it was possible to produce nanoparticles with desired size. Structure and crystallite size of CdSe thin films were determined from Hall-Williamson method using X-ray diffraction data. The composition of CdSe samples was estimated by X-ray microanalysis. It was confirmed that CdSe thin film with different nanometer range crystallite sizes were synthesized with this technique, depending upon the synthesis conditions. The phase of deposited CdSe thin films also depend upon deposition conditions and cubic to hexagonal phase transition was observed with increase in substrate temperature. The effect of crystallite size on optical and electrical properties of these films was also studied. The crystallite size affects the optical band gap, electrical conductivity and mobility activation of nanocrystalline CdSe thin films. Mobility activation study suggested that there is a quasi-continuous linear distribution of three different trap levels below the conduction band.

On the Formation of the C2H6O Isomers Ethanol (C2H5OH) and Dimethyl Ether (CH3OCH3) in Star-forming Regions

NASA Astrophysics Data System (ADS)

Bergantini, Alexandre; Maksyutenko, Pavlo; Kaiser, Ralf I.

2017-06-01

The structural isomers ethanol (CH3CH2OH) and dimethyl ether (CH3OCH3) were detected in several low-, intermediate-, and high-mass star-forming regions, including Sgr B2, Orion, and W33A, with the relative abundance ratios of ethanol/dimethyl ether varying from about 0.03 to 3.4. Until now, no experimental data regarding the formation mechanisms and branching ratios of these two species in laboratory simulation experiments could be provided. Here, we exploit tunable photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS) to detect and analyze the production of complex organic molecules (COMs) resulting from the exposure of water/methane (H2O/CH4) ices to energetic electrons. The main goal is to understand the formation mechanisms in star-forming regions of two C2H6O isomers: ethanol (CH3CH2OH) and dimethyl ether (CH3OCH3). The results show that the experimental branching ratios favor the synthesis of ethanol versus dimethyl ether (31 ± 11:1). This finding diverges from the abundances observed toward most star-forming regions, suggesting that production routes on interstellar grains to form dimethyl ether might be missing; alternatively, ethanol can be overproduced in the present simulation experiments, such as via radical-radical recombination pathways involving ethyl and hydroxyl radicals. Finally, the PI-ReTOF-MS data suggest the formation of methylacetylene (C3H4), ketene (CH2CO), propene (C3H6), vinyl alcohol (CH2CHOH), acetaldehyde (CH3CHO), and methyl hydroperoxide (CH3OOH), in addition to ethane (C2H6), methanol (CH3OH), and CO2 detected from infrared spectroscopy. The yield of all the confirmed species is also determined.

Effects of septic-tank effluent on ground-water quality in northern Williamson County and southern Davidson County, Tennessee

USGS Publications Warehouse

Hanchar, D.W.

1991-01-01

An investigation of the potential contamination of ground water from septic tank systems blasted in bedrock in Williamson and Davidson Counties, Tennessee, was conducted during 1988-89. Water samples were collected from domestic and observation wells, springs, and surface-water sites in a residential subdivision in the northern part of Williamson County near Nashville. The subdivision has a high density of septic-tank field lines installed into blasted bedrock Water samples also were collected from a well located in an area of Davidson County where field lines were installed in 5 feet of soil. Samples were analyzed for major inorganic constituents, nutrients, total organic carbon, optical brighteners, and bacteria. Although results of analyses of water samples from wells indicate no effect of septic-tank effluent on ground-water quality at these sites, water from two springs located downgradient from the subdivision had slightly larger concentrations of nitrite plus nitrate (2.2 and 2.7 milligrams per liter N), and much larger concentrations of fecal coliform and fecal streptococci bacteria (2,000 to 3,200 and 700 to 900 colonies per 100 milliliters of sample, respectively), than other wells and springs sampled during 1988. Water from one of these springs contained optical brighteners, which indicates that septic-tank effluent is affecting ground-water quality.

Sorbents for High Temperature Removal of Arsenic from Coal-Derived Synthesis Gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alptekin, G.O.; Copeland, R.; Dubovik, M.

2002-09-20

Gasification technologies convert coal and other heavy feedstocks into synthesis gas feed streams that can be used in the production of a wide variety of chemicals, ranging from hydrogen through methanol, ammonia, acetic anhydride, dimethyl ether (DME), methyl tertiary butyl ether (MTBE), high molecular weight liquid hydrocarbons and waxes. Syngas can also be burned directly as a fuel in advanced power cycles to generate electricity with very high efficiency. However, the coal-derived synthesis gas contains a myriad of trace contaminants that may poison the catalysts that are used in the downstream manufacturing processes and may also be regulated in powermore » plant emissions. Particularly, the catalysts used in the conversion of synthesis gas to methanol and other liquid fuels (Fischer-Tropsch liquids) have been found to be very sensitive to the low levels of poisons, especially arsenic, that are present in the synthesis gas from coal. TDA Research, Inc. (TDA) is developing an expendable high capacity, low-cost chemical absorbent to remove arsenic from coal-derived syngas. Unlike most of the commercially available sorbents that physically adsorb arsenic, TDA's sorbent operates at elevated temperatures and removes the arsenic through chemical reaction. The arsenic content in the coal gas stream is reduced to ppb levels with the sorbent by capturing and stabilizing the arsenic gas (As4) and arsenic hydrides (referred to as arsine, AsH3) in the solid state. To demonstrate the concept of high temperature arsenic removal from coal-derived syngas, we carried out bench-scale experiments to test the absorption capacity of a variety of sorbent formulations under representative conditions. Using on-line analysis techniques, we monitored the pre- and post-breakthrough arsine concentrations over different sorbent samples. Some of these samples exhibited pre-breakthrough arsine absorption capacity over 40% wt. (capacity is defined as lb of arsenic absorbed/lb of sorbent), while maintaining an arsine outlet concentration at less than 10 ppb.« less

Proline Editing: A General and Practical Approach to the Synthesis of Functionally and Structurally Diverse Peptides. Analysis of Steric versus Stereoelectronic Effects of 4-Substituted Prolines on Conformation within Peptides

PubMed Central

Pandey, Anil K.; Naduthambi, Devan; Thomas, Krista M.; Zondlo, Neal J.

2013-01-01

Functionalized proline residues have diverse applications. Herein we describe a practical approach, proline editing, for the synthesis of peptides with stereospecifically modified proline residues. Peptides are synthesized by standard solid-phase-peptide-synthesis to incorporate Fmoc-Hydroxyproline (4R-Hyp). In an automated manner, the Hyp hydroxyl is protected and the remainder of the peptide synthesized. After peptide synthesis, the Hyp protecting group is orthogonally removed and Hyp selectively modified to generate substituted proline amino acids, with the peptide main chain functioning to “protect” the proline amino and carboxyl groups. In a model tetrapeptide (Ac-TYPN-NH2), 4R-Hyp was stereospecifically converted to 122 different 4-substituted prolyl amino acids, with 4R or 4S stereochemistry, via Mitsunobu, oxidation, reduction, acylation, and substitution reactions. 4-Substituted prolines synthesized via proline editing include incorporated structured amino acid mimetics (Cys, Asp/Glu, Phe, Lys, Arg, pSer/pThr), recognition motifs (biotin, RGD), electron-withdrawing groups to induce stereoelectronic effects (fluoro, nitrobenzoate), handles for heteronuclear NMR (19F:fluoro; pentafluorophenyl or perfluoro-tert-butyl ether; 4,4-difluoro; 77SePh) and other spectroscopies (fluorescence, IR: cyanophenyl ether), leaving groups (sulfonate, halide, NHS, bromoacetate), and other reactive handles (amine, thiol, thioester, ketone, hydroxylamine, maleimide, acrylate, azide, alkene, alkyne, aryl halide, tetrazine, 1,2-aminothiol). Proline editing provides access to these proline derivatives with no solution phase synthesis. All peptides were analyzed by NMR to identify stereoelectronic and steric effects on conformation. Proline derivatives were synthesized to permit bioorthogonal conjugation reactions, including azide-alkyne, tetrazinetrans-cyclooctene, oxime, reductive amination, native chemical ligation, Suzuki, Sonogashira, cross-metathesis, and Diels-Alder reactions. These proline derivatives allowed three parallel bioorthogonal reactions to be conducted in one solution. PMID:23402492

Methanol synthesis using a catalyst combination of alkali or alkaline earth salts and reduced copper chromite for methanol synthesis

DOEpatents

Tierney, John W.; Wender, Irving; Palekar, Vishwesh M.

1993-01-01

The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a catalyst combination comprising reduced copper chromite and basic alkali salts or alkaline earth salts. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100.degree.-160.degree. C. and the pressure range of 40-65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H.sub.2 /CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

High-yield sol-gel synthesis of well-dispersed, colorless ZrO(2) nanocrystals.

PubMed

Mizuno, Mikihisa; Sasaki, Yuichi; Lee, Sungkil; Katakura, Hitoshi

2006-08-15

A 93% high-yield synthesis of well-dispersed, colorless zirconium dioxide (ZrO(2)) nanocrystals is reported. In this synthesis, hydrolysis and condensation reactions of zirconium(IV) tert-butoxide in the presence of oleic acid (100 degrees C) formed ZrO(2) precursors. The ZrO(2) precursors were made of -Zr-O-Zr- networks surrounded by oleic acid molecules. Annealing (280 degrees C) the precursors dispersed in dioctyl ether caused crystallization of the -Zr-O-Zr- networks, thereby generating 4 nm ZrO(2) nanocrystals stabilized with oleic acid. The particles were highly crystalline and tetragonal phase. A dense ZrO(2) nanocrystal dispersion in toluene (280 mg/mL) showed a transmittance of about 90% (3 mm optical path length) in the whole visible region.

Distribution, Health, and Development of Larval and Juvenile Lost River and Shortnose Suckers in the Williamson River Delta Restoration Project and Upper Klamath Lake, Oregon: 2008 Annual Data Summary

USGS Publications Warehouse

Burdick, Summer M.; Ottinger, Christopher; Brown, Daniel T.; VanderKooi, Scott P.; Robertson, Laura; Iwanowicz, Deborah

2009-01-01

Federally endangered Lost River sucker Deltistes luxatus and shortnose sucker Chasmistes brevirostris were once abundant throughout their range but populations have declined; they have been extirpated from several lakes, and may no longer reproduce in others. Poor recruitment into the adult spawning populations is one of several reasons cited for the decline and lack of recovery of these species, and may be the consequence of high mortality during juvenile life stages. High larval and juvenile sucker mortality may be exacerbated by an insufficient quantity of suitable rearing habitat. Within Upper Klamath Lake, a lack of marshes also may allow larval suckers to be swept from suitable rearing areas downstream into the seasonally anoxic waters of the Keno Reservoir. The Nature Conservancy (TNC) flooded about 3,600 acres to the north of the Williamson River mouth (Tulana Unit) in October 2007, and about 1,400 acres to the south and east of the Williamson River mouth (Goose Bay Unit) a year later, to retain larval suckers in Upper Klamath Lake, create nursery habitat for suckers, and improve water quality. In collaboration with TNC, the Bureau of Reclamation, and Oregon State University, we began a long-term collaborative research and monitoring program in 2008 to assess the effects of the Williamson River Delta restoration on the early life-history stages of Lost River and shortnose suckers. Our approach includes two equally important aspects. One component is to describe habitat use and colonization processes by larval and juvenile suckers and non-sucker fish species. The second is to evaluate the effects of the restored habitat on the health and condition of juvenile suckers. This report contains a summary of the first year of data collected as a part of this monitoring effort.

Regioselective oxyalkylation of vinylarenes catalyzed by diatomite-supported manganese oxide nanoparticles.

PubMed

Sun, Huayin; Zhang, Yonghui; Guo, Fengfeng; Zha, Zhenggen; Wang, Zhiyong

2012-04-06

A regioselective oxyalkylation reaction of vinylarenes with cyclic ethers was developed under the catalysis of a new heterogeneous catalyst, the diatomite-supported Mn(3)O(4) nanoparticles (SMONP-1). The use of this heterogeneous catalyst provided a novel approach for the synthesis of α-carbonyled β-alkylated aryl derivatives via a sp(3) C-H bond functionalization under mild aerobic conditions.

Synthesis of Energetic Materials

DTIC Science & Technology

1988-03-01

reacted with excess ethyl urethane, under boron trifluoride catalysis in trifluoroacetic acid, to give the 2,3-bisurethane derivative. This conversion... trifluoride catalysis, to give none of the imidazolidine (1), but only a low yield of the MEDINA derivative (5), via an obscure reaction pathway...trifluoroacetic acid under boron trifluoride catalysis. The major product, isolated in high yield, was the tricyclic ether (18). In fact, compound 18 was

Piperidine Synthesis.

DTIC Science & Technology

1992-09-01

ORGANIZATION NAME(S) AND ADORESS(ES) B . PERFORMING ORGANIZATION CDR, CRDEC, ATTN: SMCCR-RSC-O, APG, MD REPORT NUMBER 21010-5423 CRDEC-TR-409 9. SPONSORING...hydroxypyridine with iodomethane or benzyl chloride followed by sodium borohydride reduction and HBr cleavage of the enol ether is yet another effective...Piperidine, Elsevier, New York, 1991. ( b ) Armardgo, W.L.F., "Stereochemistry of Heterocyclic Compounds, Part 1," John Wiley & Sons, New York, 1977. (c

Boron-containing chlorins and tetraazaporphyrins: synthesis and cell uptake of boronated pyropheophorbide a derivatives.

PubMed

Ratajski, Michal; Osterloh, Jens; Gabel, Detlef

2006-03-01

The literature on the synthesis and the biological properties of boron-containing chlorins and phthalocyanines is reviewed. A series of homologous derivatives of pyropheophorbide A is described. The compounds contain the B(12)H(11)SH(2-) cluster attached to the single carboxyl group and vary in the length of the alkyl chain (methyl, propyl, pentyl, heptyl and nonyl) attached via an ether linkage to the former vinyl group. Cellular uptake was found for all derivatives except the nonyl sidechain. The compounds were moderately cell-toxic. Localization in lysosomes could be excluded; the compounds localized probably in the mitochondria.

Synthesis of prostaglandin and phytoprostane B1 via regioselective intermolecular Pauson-Khand reactions.

PubMed

Vázquez-Romero, Ana; Cárdenas, Lydia; Blasi, Emma; Verdaguer, Xavier; Riera, Antoni

2009-07-16

A new approach to the synthesis of prostaglandin and phytoprostanes B(1) is described. The key step is an intermolecular Pauson-Khand reaction between a silyl-protected propargyl acetylene and ethylene. This reaction, promoted by NMO in the presence of 4 A molecular sieves, afforded the 3-tert-butyldimethylsilyloxymethyl-2-substituted-cyclopent-2-en-1-ones (III) in good yield and with complete regioselectivity. Deprotection of the silyl ether, followed by Swern oxidation, gave 3-formyl-2-substituted-cyclopent-2-en-1-ones (II). Julia olefination of the aldehydes II with the suitable chiral sulfone enabled preparation of PPB(1) type I and PGB(1).

Synthesis of Substituted 2,3,5,6-tetraarylbenzo(1,2-b:5,4-b')difurans

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Mahmoud; Auping, Judith V.; Meador, Michael A.

1995-01-01

A series of substituted 2,3,5,6-tetraarylbenzo(l,2-b:5,4-b')difurans 1 was synthesized. This synthesis is based upon the photocyclization of 2,5-dibenzoylresorcinol dibenzyl ethers to the corresponding tetrahydrobenzo(1,2-b:5,4-b')difurans. Treatment of the photoproducts with methanesulfonyl chloride in pyridine afforded 1 in overall yields ranging from 30-72%. A number of these compounds have high fluorescence quantum yields (of phi(sub f) = 0.76-0.90), and their fluorescence spectra exhibit large solvatochromic shifts. These compounds may be suitable for use as fluorescent probes.

Lipid oxidation by hypochlorous acid: chlorinated lipids in atherosclerosis and myocardial ischemia

PubMed Central

Ford, David A

2011-01-01

Leukocytes, containing myeloperoxidase (MPO), produce the reactive chlorinating species, HOCl, and they have important roles in the pathophysiology of cardiovascular disease. Leukocyte-derived HOCl can target primary amines, alkenes and vinyl ethers of lipids, resulting in chlorinated products. Plasmalogens are vinyl ether-containing phospholipids that are abundant in tissues of the cardiovascular system. The HOCl oxidation products derived from plasmalogens are α-chlorofatty aldehyde and unsaturated molecular species of lysophosphatidylcholine. α-chlorofatty aldehyde is the precursor of both α-chlorofatty alcohol and α-chlorofatty acid. Both α-chlorofatty aldehyde and α-chlorofatty acid accumulate in activated neutrophils and have disparate chemotactic properties. In addition, α-chlorofatty aldehyde increases in activated monocytes, human atherosclerotic lesions and rat infarcted myocardium. This article addresses the pathways for the synthesis of these lipids and their biological targets. PMID:21339854

Study of lattice strain and optical properties of nanocrystalline SnO2

NASA Astrophysics Data System (ADS)

Ahmad, Naseem; Khan, Shakeel; Bhargava, Richa; Ansari, Mohd Mohsin Nizam

2018-05-01

Nanocrystalline SnO2 has been synthesized by co-precipitation method by using two solvents (water and ethylene glycol). The structure and surface morphology were investigated using XRD and scanning electron microscope (SEM). The optical properties were studied using diffused reflectance spectroscopy (DRS). From the XRD analysis, the prepared materials are found to be pure crystalline with tetragonal rutile structure. The lattice strain and crystallite size, were calculated using Williamson-Hall method, are found to be 0.00413 & 16.3 nm in water assisted SnO2 and 0.00495 & 35.6 nm for EG assisted SnO2. Study of surface morphology of the samples was carried out using SEM. It has been seen that the solvents which are used in synthesis can also alter the optical properties of the materials. The optical band gap of the water based SnO2 and EG based SnO2 are found to be 3.92eV and 3.86eV respectively.

Highly Sensitive NiO Nanoparticle based Chlorine Gas Sensor

NASA Astrophysics Data System (ADS)

Arif, Mohd.; Sanger, Amit; Singh, Arun

2018-03-01

We have synthesized a chemiresistive sensor for chlorine (Cl2) gas in the range of 2-200 ppm based on nickel oxide (NiO) nanoparticles obtained by wet chemical synthesis. The nanoparticles were characterized by x-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, and photoluminescence (PL) spectroscopy. XRD spectra of the sensing layer revealed the cubic phase of NiO nanoparticles. The NiO nanoparticle size was calculated to be ˜ 21 nm using a Williamson-Hall plot. The bandgap of the NiO nanoparticles was found to be 3.13 eV using Tauc plots of the absorbance curve. Fast response time (12 s) and optimum recovery time (˜ 27 s) were observed for 10 ppm Cl2 gas at moderate temperature of 200°C. These results demonstrate the potential application of NiO nanoparticles for fabrication of highly sensitive and selective sensors for Cl2 gas.

Construction, geologic, and water-level data for observation wells near Brentwood, Williamson County, Tennessee

USGS Publications Warehouse

Hanchar, Dorothea Withington

1989-01-01

Thirty-four observation wells were installed at 17 sites in the area of a hazardous-waste disposal site near Brentwood, in Williamson County, Tennessee. These wells were installed to supplement data collected from domestic wells in the area, to help define the geology of the study area and to determine the water levels. Both lithologic and geophysical logs were obtained for each well drilled to help define the formations encountered. Four limestone units, corresponding to the Bigby-Cannon limestone, the Hermitage Formation, the Carters Limestone (including the T-3 bentonite), and the Lebanon Limestone, were described from well cuttings and borehole geophysical logs. Water levels have been collected at both the shallow and deep wells at each site. (USGS)

Zeolite catalysis in the synthesis of isobutylene from hydrous ethanol

NASA Astrophysics Data System (ADS)

Phillips, Cory Bernard

1999-11-01

This work deals with the synthesis of isobutylene from a hydrous ethanol feedstock over zeolites. The synthesis is accomplished in three steps: (1) low-temperature direct ethanol conversion to ethylene on H-ZSM-5 zeolite, (2) ethylene conversion to butene products over metal-exchanged zeolites, and (3) butene skeletal rearrangement to isobutylene over FER zeolites. The key to understanding and optimizing each synthesis step lies in the ability to control and regulate the zeolite acidity (Bronsted and Lewis)---both strength and number. Therefore, the continuous temperature programmed amine desorption (CTPAD) technique was further developed to simultaneously count the Bronsted acid sites and quantitatively characterize their strength. The adsorption of ethanol, reaction products, amines, coke and ethanol-derived residue (EDR) were monitored gravimetrically using the highly sensitive, novel Tapered Element Oscillating Microreactor (TEOM) apparatus. The TEOM was also used also in conjunction with CTPAD to characterize Bronsted acidity which is a new application for the instrument. For the first synthesis step, a parallel reaction exists which simultaneously produces diethyl ether and ethylene directly over H-ZSM-5. The reaction rates for each pathway were measured directly using a differential reactor operating at low temperatures (<473 K). Water in the ethanol feed enhances the rate of ethylene formation. A mechanism and kinetic expression are proposed for this reaction over H-ZSM-5, with diethyl-ether desorption and ethylene formation as the rate limiting steps. Heat of adsorption values measured from the independent microcalorimetry work reported in the literature are incorporated into the kinetic analysis which reduces the number of regressed parameters. For the remaining synthesis steps, several zeolite structures (ZSM-5, Y, FER) partially exchanged with Pd, Ti, Ni and Au were prepared and tested. It was determined from this screening study that the zeolites containing Pd are the most efficient catalysts for the dimerization reaction. Characterization results from x-ray diffraction (XRD), electron paramagnetic resonance (EPR) spectroscopy, and CTPAD suggest a stable, Pd species with a low oxidation state as part of the active site in Pd-exchanged zeolites. Isobutylene was present in the C4 fraction at reasonable quantities for most of the catalyst candidates, especially those containing an alkali metal co-cation.

Identification and Characterization of Heptaprenylglyceryl Phosphate Processing Enzymes in Bacillus subtilis.

PubMed

Linde, Mona; Peterhoff, David; Sterner, Reinhard; Babinger, Patrick

2016-07-08

In Archaea, ether lipids play an essential role as the main building blocks of the cellular membrane. Recently, ether lipids have also been discovered in the domain of Bacteria, and the key enzymes that catalyze their synthesis, glycerol-1-phosphate dehydrogenase and heptaprenylglyceryl phosphate synthase, have been described. In Bacillales, heptaprenylglyceryl phosphate does not become linked to a second polyprenyl moiety like ether lipids in Archaea but is dephosphorylated and acetylated. Here, we report on the enzymes that catalyze these reactions. We enriched the phosphatase activity from a B. subtilis cell extract and suppose that dephosphorylation is catalyzed by the phosphatase PhoB or by any other phosphatase in an unspecific manner. By screening a B. subtilis knock-out library for deficiency in acetylation, the yvoF gene product was identified to be the acetyltransferase. The acetyl-CoA-dependent enzyme YvoF is a close relative of maltose O-acetyltransferase (MAT). Its catalytic properties were analyzed and compared with MAT. YvoF and MAT partially overlap in substrate and product range in vitro, but MAT is not able to complement the yvoF knock-out in vivo. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Synthesis and characterization of poly(L-alanine)-block-poly(ethylene glycol) monomethyl ether as amphiphilic biodegradable co-polymers.

PubMed

Zhang, Guolin; Ma, Jianbiao; Li, Yanhong; Wang, Yinong

2003-01-01

Di-block co-polymers of poly(L-alanine) with poly(ethylene glycol) monomethyl ether (MPEG) were synthesized as amphiphilic biodegradable co-polymers. The ring-opening polymerization of N-carboxy-L-alanine anhydride (NCA) in dichloromethane was initiated by amino-terminated poly(ethylene glycol) monomethyl ether (MPEG-NH2, M(n) = 2000) to afford poly(L-alanine)-block-MPEG. The weight ratio of two blocks in the co-polymers could be altered by adjusting the feeding ratio of NCA to MPEG-NH2. Their chemical structures were characterized on the basis of infrared spectrometry and nuclear magnetic resonance. According to circular dichroism measurement, the poly(L-alanine) chain on the co-polymers in an aqueous medium had a alpha-helix conformation. Two melting points from MPEG block and poly(L-alanine), respectively, could be observed in differential scanning calorimetry curves of the co-polymers, suggesting that a micro-domain phase separation appeared in their bulky states. The co-polymers could take up some water and the capacity was dependent on the ratio of poly(L-alanine) block to MPEG. Such co-polymers might be useful in drug-delivery systems and other biomedical applications.

Synthesis of Nucleoside Analogues with Potential Antiviral Activity against Negative Strand RNA Virus Targets

DTIC Science & Technology

1989-11-01

standing overnight. Washing the filtered crystals with ether removed triethylamine hydrochloride and triphenyl phosphine, then recrystallisation from...pyridine to from an ester, DMF and pyridinium hydrochloride . The reaction of the Vilsmeier reagent with (E)-5-(2-carboxyvinyl)uridine and quenching...include 2-deoxy-2-glucose (28), D- glucosamine (29) and tunicamycin (30). Deoxyglucose is utilized instead of glucose in the formation of guanosine

Development of GREET Catalyst Module

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhichao; Benavides, Pahola T.; Dunn, Jennifer B.

2015-09-01

In this report, we develop energy and material flows for the production of five different catalysts (tar reforming, alcohol synthesis, Zeolite Socony Mobil-5 [ZSM-5], Mo/Co/ γ-Al 2O3, and Pt/ γ-Al 2O 3) and two chemicals (olivine, dimethyl ether of polyethylene glycol [DEPG]). These compounds and catalysts are now included in the Greenhouse Gases, Regulated Emissions and Energy Use in Transportation (GREET™) catalyst module.

Total synthesis of fluoxetine and duloxetine through an in situ imine formation/borylation/transimination and reduction approach.

PubMed

Calow, Adam D J; Fernández, Elena; Whiting, Andrew

2014-08-28

We report efficient, catalytic, asymmetric total syntheses of both (R)-fluoxetine and (S)-duloxetine from α,β-unsaturated aldehydes conducting five sequential one-pot steps (imine formation/copper mediated β-borylation/transimination/reduction/oxidation) followed by the specific ether group formation which deliver the desired products (R)-fluoxetine in 45% yield (96% ee) and (S)-duloxetine in 47% yield (94% ee).

Improved surface hydrophilicity and antifouling property of polysulfone ultrafiltration membrane with poly(ethylene glycol) methyl ether methacrylate grafted graphene oxide nanofillers

NASA Astrophysics Data System (ADS)

Wang, Haidong; Lu, Xiaofei; Lu, Xinglin; Wang, Zhenghui; Ma, Jun; Wang, Panpan

2017-12-01

In this study, the GO-g-P(PEGMA) nanoplates were first synthesized by grafting hydrophilic poly (poly (ethylene glycol) methyl ether methacrylate) via surface-initiated atom transfer radical polymerization (SI-ATRP) method. A novel polysulfone (PSF) nanocomposite membrane using GO-g-P(PEGMA) nanoplates as nanofillers was fabricated. FTIR, TGA, 1H NMR, GPC and TEM were applied to verify the successful synthesis of the prepared nanoplates, while SEM, AFM, XPS, contact angle goniometry and filtration experiments were used to characterize the fabricated nanocomposite membranes. It was found that the new prepared nanofillers were well dispersed in organic PSF matrix, and the PSF/GO-g-P(PEGMA) nanocomposite membrane showed significant improvements in water flux and flux recovery rate. Based on the results of resistance-in-series model, the nanocomposite membrane exhibited superior resistance to the irreversible fouling. The excellent filtration and antifouling performance are attributed to the segregation of GO-g-P(PEMGA) nanofillers toward the membrane surface and the pore walls. Notably, the blended nanofillers appeared a stable retention in/on nanocomposite membrane after 30 days of washing time. The demonstrated method of synthesis GO-g-P(PEGMA) in this study can also be extended to preparation of other nanocomposite membrane in future.

Propylene glycol monomethyl ether (PGME): inhalation toxicity and carcinogenicity in Fischer 344 rats and B6C3F1 mice.

PubMed

Spencer, Pamela J; Crissman, James W; Stott, William T; Corley, Richard A; Cieszlak, Frank S; Schumann, Alan M; Hardisty, Jerry F

2002-01-01

A series of inhalation studies with propylene glycol monomethyl ether (PGME) vapor were undertaken to characterize its subchronic toxicity in mice and chronic toxicity/oncogenicity in rats and mice. Groups of male and female Fischer 344 rats and B6C3F1 mice were exposed to 0, 300, 1,000, or 3,000 ppm vapor from 1 week to 2 years. Primary treatment-related effects included: initial sedation of animals exposed to 3,000 ppm and its subsequent resolution correlating with induction of hepatic mixed function oxidase activity and S-phase DNA synthesis; elevated mortality in high-exposure male rats and mice (chronic study); elevated deposition of alpha2u-globulin (alpha2U-G) and associated nephropathy and S-phase DNA synthesis in male rat kidneys; accelerated atrophy of the adrenal gland X-zone in female mice (subchronic study only); and increased occurrence and/or severity of eosinophilic foci of altered hepatocytes in male rats. No toxicologically relevant statistically significant increases in neoplasia occurred in either species. A numerical increase in the incidence of kidney adenomas occurred in intermediate-exposure male rats; however, the association with alpha2U-G nephropathy, a male rat specific effect, indicated a lack of relevance for human risk assessment.

New cytotoxic benzosuberene analogs. Synthesis, molecular modeling and biological evaluation.

PubMed

Chen, Zecheng; Maderna, Andreas; Sukuru, Sai Chetan K; Wagenaar, Melissa; O'Donnell, Christopher J; Lam, My-Hanh; Musto, Sylvia; Loganzo, Frank

2013-12-15

In this Letter we describe the synthesis and biological evaluation of new benzosuberene analogs with structural modifications on the B-ring. The focus was initially to probe the chemical space around the B-ring C-8 position. This position was readily available for derivatization chemistry using our recently developed new synthesis for this compound class. Furthermore, we describe two new B-ring analogs, one containing a diene and the other a cyclic ether group. Both new analogs show excellent potencies in tumor cell proliferation assays. In addition, we describe molecular modeling studies that provide a binding rationale for reference compound 8 in the colchicine binding site using the known colchicine crystal structure. We also examine whether the cell based potency data obtained with selected new analogs are supported by modeling results. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of Ce2O3, La2O3 and ZnO additives on the oxygenates conversion into liquid hydrocarbons

NASA Astrophysics Data System (ADS)

Kachalov, V. V.; Lavrenov, V. A.; Lishchiner, I. I.; Malova, O. V.; Tarasov, A. L.; Zaichenko, V. M.

2018-01-01

A selective modifying effect of cerium, magnesium and zinc oxide additives on the activity and the selectivity of a pentasil group zeolite catalyst in the reaction of conversion of oxygenates (methanol and dimethyl ether) to liquid hydrocarbons was found. It was found that zinc oxide contributes to the stable operation of the zeolite catalyst in the conversion of oxygenates in the synthesis gas stream and leads to the production of gasolines with low durene content (not more than 6.1 wt%). The obtained results demonstrate the rationale for producing hydrocarbons from synthesis gas without the stage of oxygenate separation with their subsequent conversion to synthetic gasoline.

Asymmetric Synthesis of Secondary and Tertiary Propargylic Alcohols by Umpolung of Acetylenic Sulfones and ortho-Sulfinyl Carbanions.

PubMed

Rodríguez, Ricardo I; Ramírez, Elsie; Yuste, Francisco; Sánchez-Obregón, Rubén; Alemán, José

2018-02-16

The generation of diastereomerically enriched secondary benzyl propargyl alcohols by the asymmetric addition of ortho-sulfinylbenzyl carbanions to sulfonylacetylene derivatives via formation of a Csp-Csp 3 bond is described. This reaction proceeds through an unusual α-attack (anti-Michael addition) of the ortho-sulfinylbenzyl carbanions, followed by elimination of the arylsulfonyl moiety. The scope of this alkynylation reaction is also discussed. Moreover, the development of a new approach for the synthesis of optically active tertiary benzylpropargyl alcohols is described, discussing the possible stereocourse of the reaction so as the influence of the ether 18-crown-6 and steric importance of acetylenic substituent.

Crystallite size strain analysis of nanocrystalline La0.7Sr0.3MnO3 perovskite by Williamson-Hall plot method

NASA Astrophysics Data System (ADS)

Kumar, Dinesh; Verma, Narendra Kumar; Singh, Chandra Bhal; Singh, Akhilesh Kumar

2018-04-01

The nanocrystalline Sr-doped LaMnO3 (La0.7Sr0.3MnO3 = LSMO) perovskite manganites having different crystallite size were synthesized using the nitrate-glycine auto-combustion method. The phase purity of the manganites was checked by X-ray diffraction (XRD) measurement. The XRD patterns of the sample reveal that La0.7S0.3MnO3 crystallizes into rhombohedral crystal structure with space group R-3c. The size-dependence of structural lattice parameters have been investigated with the help of Rietveld refinement. The structural parameters increase as a function of crystallite size. The crystallite-size and internal strain as a function of crystallite-size have been calculated using Williamson-Hall plot.

Darcy-Forchheimer Three-Dimensional Flow of Williamson Nanofluid over a Convectively Heated Nonlinear Stretching Surface

NASA Astrophysics Data System (ADS)

Hayat, Tasawar; Aziz, Arsalan; Muhammad, Taseer; Alsaedi, Ahmed

2017-09-01

The present study elaborates three-dimensional flow of Williamson nanoliquid over a nonlinear stretchable surface. Fluid flow obeys Darcy-Forchheimer porous medium. A bidirectional nonlinear stretching surface generates the flow. Convective surface condition of heat transfer is taken into consideration. Further the zero nanoparticles mass flux condition is imposed at the boundary. Effects of thermophoresis and Brownian diffusion are considered. Assumption of boundary layer has been employed in the problem formulation. Convergent series solutions for the nonlinear governing system are established through the optimal homotopy analysis method (OHAM). Graphs have been sketched in order to analyze that how the velocity, temperature and concentration distributions are affected by distinct emerging flow parameters. Skin friction coefficients and local Nusselt number are also computed and discussed.

Geology of an area near Brentwood, Williamson County, Tennessee

USGS Publications Warehouse

Hanchar, D.W.

1988-01-01

The geology and structure of an area near Brentwood, Williamson County, Tennessee, were studied to define the potential aquifers and confining units that comprise the groundwater flow system of the area. Four different formations were identified. These formations are, in descending order, the Bigby-Cannon Limestone, the Hermitage Formation, the Carters Limestone, and the Lebanon Limestone. The Bigby-Cannon Limestone and the Hermitage Formation have been affected by recent erosion. Any variation of the Carters Limestone is controlled by pre-Carters erosion of the top of the Lebanon Limestone. The thickness of this formation ranges from 65 to 79 ft. A small scale anticline-syncline pair is evident. This structure is not a result of erosion and also occurs in the T-3 bentonite bed in the Carters Limestone. (USGS)

Direct synthesis of ethanol from dimethyl ether and syngas over combined H-Mordenite and Cu/ZnO catalysts.

PubMed

Li, Xingang; San, Xiaoguang; Zhang, Yi; Ichii, Takashi; Meng, Ming; Tan, Yisheng; Tsubaki, Noritatsu

2010-10-25

Ethanol was directly synthesized from dimethyl ether (DME) and syngas with the combined H-Mordenite and Cu/ZnO catalysts that were separately loaded in a dual-catalyst bed reactor. Methyl acetate (MA) was formed by DME carbonylation over the H-Mordenite catalyst. Thereafter, ethanol and methanol were produced by MA hydrogenation over the Cu/ZnO catalyst. With the reactant gas containing 1.0% DME, the optimized temperature for the reaction was at 493 K to reach 100% conversion. In the products, the yield of methanol and ethanol could reach 46.3% and 42.2%, respectively, with a small amount of MA, ethyl acetate, and CO(2). This process is environmentally friendly as the main byproduct methanol can be recycled to DME by a dehydration reaction. In contrast, for the physically mixed catalysts, the low conversion of DME and high selectivity of methanol were observed.

New developments in thermally stable polymers

NASA Technical Reports Server (NTRS)

Hergenrother, Paul M.

1991-01-01

Advances in high-temperature polymers since 1985 are discussed with the emphasis on the chemistry. High-temperature polymers refer to materials that exhibit glass-transition temperatures greater than 200 C and have the chemical structure expected to provide high thermooxidative stability. Specific polymers or series of polymers were selected to show how the chemical structure influences certain properties. Poly(arylene ethers) and polyimides are the two principal families of polymers discussed. Recent work on poly(arylene ethers) has concentrated on incorporating heterocyclic units within the polymer backbone. Recent polyimide work has centered on the synthesis of new polymers from novel monomers, several containing the trifluoromethyl group strategically located on the molecule. Various members in each of these polymer families display a unique combination of properties, heretofore unattainable. Other families of polymers are also briefly discussed with a polymer from an AB maleimidobenzocyclobutene exhibiting an especially attractive combination of properties.

Synthesis and Characterization of Poly (Arylene Ether Benzimidazole) Oligomers

NASA Technical Reports Server (NTRS)

Leonard, Michael J.

1995-01-01

Several poly(arylene ether benzimidazole) oligomers were prepared by the nucleophilic aromatic substitution reaction of a bisphenol benzimidazole and various alkyl-substituted aromatic bisphenols with an activated aromatic dihalide in N, N-dimethylacetarnide. Moderate to high molecular weight terpolymers were obtained in all cases, as shown by their inherent viscosities, which ranged from 0.50 to 0.87 dL g(sup -1). Glass transition temperatures (T(sub g)s) of polymer powders ranged from 267-280 C. Air-dried unoriented thin film T(sub g)s were markedly lower than those of the powders, whereas T(sub g)s of films dried in a nitrogen atmosphere were identical to those of the corresponding powders. In addition, air-dried films were dark amber and brittle, whereas nitrogen-dried films were yellow and creasable. Nitrogen-dried films showed slightly higher thin-film tensile properties than the air-dried films, as well.

Methanol synthesis using a catalyst combination of alkali or alkaline earth salts and reduced copper chromite

DOEpatents

Tierney, J.W.; Wender, I.; Palekar, V.M.

1995-01-24

The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a catalyst combination comprising reduced copper chromite and basic alkali salts or alkaline earth salts. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100--160 C and the pressure range of 40--65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H[sub 2]/CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

Methanol synthesis using a catalyst combination of alkali or alkaline earth salts and reduced copper chromite

DOEpatents

Tierney, John W.; Wender, Irving; Palekar, Vishwesh M.

1995-01-01

The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a catalyst combination comprising reduced copper chromite and basic alkali salts or alkaline earth salts. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100.degree.-160.degree. C. and the pressure range of 40-65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H.sub.2 /CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

On the Formation of the C{sub 2}H{sub 6}O Isomers Ethanol (C{sub 2}H{sub 5}OH) and Dimethyl Ether (CH{sub 3}OCH{sub 3}) in Star-forming Regions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergantini, Alexandre; Maksyutenko, Pavlo; Kaiser, Ralf I., E-mail: ralfk@hawaii.edu

The structural isomers ethanol (CH{sub 3}CH{sub 2}OH) and dimethyl ether (CH{sub 3}OCH{sub 3}) were detected in several low-, intermediate-, and high-mass star-forming regions, including Sgr B2, Orion, and W33A, with the relative abundance ratios of ethanol/dimethyl ether varying from about 0.03 to 3.4. Until now, no experimental data regarding the formation mechanisms and branching ratios of these two species in laboratory simulation experiments could be provided. Here, we exploit tunable photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS) to detect and analyze the production of complex organic molecules (COMs) resulting from the exposure of water/methane (H{sub 2}O/CH{sub 4}) ices to energetic electrons.more » The main goal is to understand the formation mechanisms in star-forming regions of two C{sub 2}H{sub 6}O isomers: ethanol (CH{sub 3}CH{sub 2}OH) and dimethyl ether (CH{sub 3}OCH{sub 3}). The results show that the experimental branching ratios favor the synthesis of ethanol versus dimethyl ether (31 ± 11:1). This finding diverges from the abundances observed toward most star-forming regions, suggesting that production routes on interstellar grains to form dimethyl ether might be missing; alternatively, ethanol can be overproduced in the present simulation experiments, such as via radical–radical recombination pathways involving ethyl and hydroxyl radicals. Finally, the PI-ReTOF-MS data suggest the formation of methylacetylene (C{sub 3}H{sub 4}), ketene (CH{sub 2}CO), propene (C{sub 3}H{sub 6}), vinyl alcohol (CH{sub 2}CHOH), acetaldehyde (CH{sub 3}CHO), and methyl hydroperoxide (CH{sub 3}OOH), in addition to ethane (C{sub 2}H{sub 6}), methanol (CH{sub 3}OH), and CO{sub 2} detected from infrared spectroscopy. The yield of all the confirmed species is also determined.« less

Synthesis of Potential Trypanocides

DTIC Science & Technology

1987-12-01

0188 Ia. REPORT SECURITY CLASSIFICATION 1b RESTRICTIVE MARKINGS Unclassified 2a. SECURITY CLASSIFICATION AUTHORITY 3 . DISTRIBUTION /AVAILABILITY OF...and the phenyl ring, ring structures 2 and 3 , introduction of a -CH:CII- group between the phenyl ring and its 4’-substituent, ring structure 4...imidazole (9, 15) thiazole (11) and pyridine (12-14) into ether-linked and vinyl-linked structures. 3 t % SCHEME 1 HETEROAROMATIC RINGS OHw Ch3 CH3 +1 N% f

Process for synthesis of ammonia borane for bulk hydrogen storage

DOEpatents

Autrey, S Thomas [West Richland, WA; Heldebrant, David J [Richland, WA; Linehan, John C [Richland, WA; Karkamkar, Abhijeet J [Richland, WA; Zheng, Feng [Richland, WA

2011-03-01

The present invention discloses new methods for synthesizing ammonia borane (NH.sub.3BH.sub.3, or AB). Ammonium borohydride (NH.sub.4BH.sub.4) is formed from the reaction of borohydride salts and ammonium salts in liquid ammonia. Ammonium borohydride is decomposed in an ether-based solvent that yields AB at a near quantitative yield. The AB product shows promise as a chemical hydrogen storage material for fuel cell powered applications.

Resource partitioning among woodpeckers in northeastern Oregon.

Treesearch

Bull Evelyn L.; Steven R. Peterson; Jack Ward. Thomas

1986-01-01

Eight species of woodpeckers coexist in conifer forests in northeastern Oregon: northern flicker (Colaptes auratus); yellow-bellied (Sphyrapicus varius) and Williamson's (S. thyroideus) sapsuckers; and pileated (Dryocopus pileatus), hairy (Picoides villosus),...

Studies Toward the Total Synthesis of Eletefine

NASA Astrophysics Data System (ADS)

Rugg, Kyle William

Eletefine is a natural product of the stephaoxocane family of alkaloids. It possesses an isoquinoline moiety functionalized with three methoxy groups forming an electron rich aromatic system. Eletefine also possesses a ten-membered ring with a novel bridged vinyl ether functionality, and a remote chiral alcohol, making it a conspicuous and desirable target for the synthetic organic chemist. The plant from which eletefine was first isolated (Cissampelos glaberrima ) has been used in traditional medicine for the relief of symptoms from urinary tract infections and asthma. The proposed synthesis of eletefine is a convergent route which features a Sonogashira coupling and a novel alkyne hydration. Herein, methods towards the synthesis of the model system des-hydroxyeletefine are described, in particular attempts towards formation of the AB ring system of des-hydroxyeletefine, as well as C8-C9 bond formation methodology via acylation and Sonogashira coupling.

Advances in chemical synthesis of structurally modified bioactive RNAs.

PubMed

Li, Ziyuan; Zhou, Haipin; Wu, Xiaoming; Yao, Hequan

2013-01-01

Methods for the chemical synthesis of RNA have been available for almost half century, and presently, RNA could be chemically synthesized by automated synthesizers, using protected ribonucleosides preactivated as phosphoramidites, which has already been covered by many reviews. In addition to advancement on synthetic methods, a variety of modifications have also been made on the synthesized oligonucleotides, and previous reviews on the general synthesis of RNAs have not covered this area. In this tutorial review, three types of modifications have been summarized standing at the viewpoint of medicinal chemistry: (1) modifications on nucleobase, comprising substituent introduction and replacement with pseudobase; (2) modifications on ribose, consisting of modifications on the 2', 3' or 5'-position, alternation of configuration, and conformational restriction on ribose; (3) modifications on internucleoside linkages, including amide, formacetal, sulfide, sulfone, ether, phosphorothiolate and phosphorothioate linkages. Synthetic methods achieving these modifications along with the functions or values of these modifications have also been discussed and commented on.

31. Fourth floor attic, operating room with skylight, view to ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. Fourth floor attic, operating room with skylight, view to south - Portsmouth Naval Hospital, Hospital Building, Rixey Place, bounded by Williamson Drive, Holcomb Road, & The Circle, Portsmouth, Portsmouth, VA

A Mechanistical Study on the Formation of Dimethyl Ether (CH3OCH3) and Ethanol (CH3CH2OH) in Methanol-containing Ices and Implications for the Chemistry of Star-forming Regions

NASA Astrophysics Data System (ADS)

Bergantini, Alexandre; Góbi, Sándor; Abplanalp, Matthew J.; Kaiser, Ralf I.

2018-01-01

The underlying formation mechanisms of complex organic molecules (COMs)—in particular, structural isomers—in the interstellar medium (ISM) are largely elusive. Here, we report new experimental findings on the role of methanol (CH3OH) and methane (CH4) ices in the synthesis of two C2H6O isomers upon interaction with ionizing radiation: ethanol (CH3CH2OH) and dimethyl ether (CH3OCH3). The present study reproduces the interstellar abundance ratios of both species with ethanol to dimethyl ether branching ratios of (2.33 ± 0.14):1 suggesting that methanol and methane represents the key precursor to both isomers within interstellar ices. Exploiting isotopic labeling combined with reflectron time-of-flight mass spectrometry (Re-TOF-MS) after isomer selective vacuum ultra-violet (VUV) photoionization of the neutral molecules, we also determine the formation mechanisms of both isomers via radical–radical recombination versus carbene (CH2) insertion with the former pathway being predominant. Formation routes to higher molecular weight reaction products such as ethylene glycol (HOCH2CH2OH), dimethyl peroxide (CH3OOCH3), and methoxymethanol (CH3OCH2OH) are discussed briefly as well.

Thioether-Bearing Hyperbranched Polyether Polyols with Methionine-Like Side-Chains: A Versatile Platform for Orthogonal Functionalization.

PubMed

Seiwert, Jan; Herzberger, Jana; Leibig, Daniel; Frey, Holger

2017-01-01

The synthesis of thioether-bearing hyperbranched polyether polyols based on an AB/AB 2 type copolymerization (cyclic latent monomers) is introduced. The polymers are prepared by anionic ring-opening multibranching copolymerization of glycidol and 2-(methylthio)ethyl glycidyl ether (MTEGE), which is conveniently accessible in a single etherification step. Slow monomer addition provides control over molecular weights. Moderate dispersities (Đ = 1.48-1.85) are obtained, given the hyperbranched structure. In situ 1 H NMR copolymerization kinetics reveal reactivity ratios of r G = 3.7 and r MTEGE = 0.27. Using slow monomer addition, copolymer composition can be systematically varied, allowing for the adjustment of the hydroxyl/thioether ratio, the degree of branching (DB = 0.36-0.48), thermal properties, and cloud point temperatures in aqueous solution in the range of 29-75 °C. Thioether oxidation to sulfoxides enables to tailor the copolymers' solubility profile. Use of these copolymers as a versatile, multifunctional platform for orthogonal modification is highlighted. The methyl sulfide groups can be selectively alkoxylated, using propylene oxide, allyl glycidyl ether, or furfuryl glycidyl ether, resulting in functional hyperbranched polyelectrolytes. Reaction of the alcohol groups with benzyl isocyanate demonstrates successful orthogonal functionalization. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficient n-doping of graphene films by APPE (aminophenyl propargyl ether): a substituent effect.

PubMed

Kim, Youngsoo; Yoo, Je Min; Jeon, Hak Rim; Hong, Byung Hee

2013-11-14

We report the synthesis and applications of APPE (aminophenyl propargyl ether) as a novel n-type dopant for graphene. The characteristics of APPE-doped graphene films were investigated using Raman spectroscopy as well as electron transport measurements. The Raman 2D/G peak ratio decreased by more than 40%, and the minimum conductivity voltage (Dirac voltage) was shifted to -133 V as the pristine graphene was doped with APPE, indicating that the graphene was strongly n-doped. We suppose that the electron donating property of the amine group (-NH2) is the origin of such an intense n-doping effect. In contrast, a similar molecule with an electron withdrawing nitro group (-NO2) (nitrophenyl propargyl ether, NPPE) showed a slight p-doping effect. Thus, we conclude that the doping effect of a molecular framework strongly depends on the functional substituents, which can be represented by the Hammett equation. We also confirmed that the sheet resistance of the APPE doped graphene film was reduced by ∼70%, which is crucial to enhance the electrical conductivity of graphene for various electronic applications. In addition, the acetylene group of APPE appears promising to be utilized in "click chemistry" to further functionalize the π-surface of graphene for sensors and bio applications.

Functionalized nanoparticles for AMF-induced gene and drug delivery

NASA Astrophysics Data System (ADS)

Biswas, Souvik

The properties and broad applications of nano-magnetic colloids have generated much interest in recent years. Specially, Fe3O4 nanoparticles have attracted a great deal of attention since their magnetic properties can be used for hyperthermia treatment or drug targeting. For example, enhanced levels of intracellular gene delivery can be achieved using Fe3O4 nano-vectors in the presence of an external magnetic field, a process known as 'magnetofection'. The low cytotoxicity, tunable particle size, ease of surface functionalization, and ability to generate thermal energy using an external alternating magnetic field (AMF) are properties have propelled Fe3O4 research to the forefront of nanoparticle research. The strategy of nanoparticle-mediated, AMF-induced heat generation has been used to effect intracellular hyperthermia. One application of this 'magnetic hyperthermia' is heat activated local delivery of a therapeutic effector (e.g.; drug or polynucleotide). This thesis describes the development of a magnetic nano-vector for AMF-induced, heat-activated pDNA and small molecule delivery. The use of heat-inducible vectors, such as heat shock protein ( hsp) genes, is a promising mode of gene therapy that would restrict gene expression to a local region by focusing a heat stimulus only at a target region. We thus aimed to design an Fe3O4 nanoparticle-mediated gene transfer vehicle for AMF-induced localized gene expression. We opted to use 'click' oximation techniques to assemble the magnetic gene transfer vector. Chapter 2 describes the synthesis, characterization, and transfection studies of the oxime ether lipid-based nano-magnetic vectors MLP and dMLP. The synthesis and characterization of a novel series of quaternary ammonium aminooxy reagents (2.1--2.4) is described. These cationic aminooxy compounds were loaded onto nanoparticles for ligation with carbonyl groups and also to impart a net positive charge on the nanoparticle surface. Our studies indicated that the non-toxic magnetoplexes (magnetic nanoparticle + pDNA complex) derived from dMLP deliver pDNA into mammalian cells even without external magnetic assistance. To date, dMLP is the only polymer-free magnetic gene delivery system that can deliver pDNA without any magnetic assistance. Chapter 3 of this thesis outlines the synthesis and characterization of other oxime ether lipids and details studies using derived-lipoplexes. These lipids were evaluated in pDNA and siRNA transfection studies in various mammalian cell lines. This work constitutes the first use of an oxime ether as the linking domain in cationic transfection lipids. These biocompatible oxime ether lipids can be readily assembled by click chemistry through ligation of hydrophobic aldehydes with quaternary ammonium aminooxy salts. Our studies showed that the oxime ether lipids transfected pDNA and siRNA efficiently in MCF-7, H 1792, and in PAR C10 cells comparable to and in some cases better than commercial transfection lipids. Chapter 4 describes the design and characterization of a nano-magnetic delivery system for AMF-induced drug (doxorubicin) release. In efforts to develop a magnetic formulation free from thermosensitive materials, such as hydrogels, we synthesized three nanoparticle-based doxorubicin formulations using charge interactions as the key associative force. To do so, we synthesized and characterized a novel cationic oxime ether conjugate at C-13 of doxorubicin. Our investigation indicated that the positive charge of the oxime ether drug conjugate tended to bind better to the negatively charged nanoparticle than did the other formulations prepared in stepwise manner. Our findings show that the nano-magnetic formulations remained essestially inactive at body temperature (37.5 °C) and released a majority of the cargo only when exposed to an external AMF. Our designed magnetic drug delivery platform is the first example of an AMF-inducible system that does not depend on the inclusion of thermosensitive materials. Finally, we have developed a bioanalytical application of the highly chemoselective oximation chemistry using aminooxy reagent 2.1. Chapter 5 describes a silica microchip containing micropillars coated with cationic aminooxy reagent 2.1. The microchip captures gaseous ketones and aldehydes from exhaled human breath. A brief description of microchip fabricated breath analyzer and breath analysis is described in Chapter 5. Our studies showed that the acetone capture efficiency of the aminooxy-loaded microchip was 98%.

Nitrogen-Containing Carbon Nanotube Synthesized from Polymelem and Activated Carbon Derived from Polymer Blend

NASA Astrophysics Data System (ADS)

Qin, Nan

Polymelem possesses a polymeric structure of heptazine (C6N 7) rings connected by amine bridges and our study has demonstrated that it is a promising precursor for the synthesis of nitrogen-containing carbon materials. Nitrogen-containing carbon nanotube (NCNT) was produced by pyrolyzing polymelem as a dual source of carbon and nitrogen with Raney nickel in a high pressure stainless steel cell. Activated carbon was produced from poly(ether ether ketone)/poly(ether imide) (PEEK/PEI blend) and incorporated with polymelem to enhance the hydrogen adsorption. Polymelem was successfully synthesized by pyrolyzing melamine at 450--650 °C and its structure was elucidated by 13C solid state NMR, FTIR, and XRD. The molecular weight determined by a novel LDI MS equipped with a LIFT mode illuminated that polymelem has both linear and cyclic connectivity with a degree of polymerization of 2--5 depending on the synthesis temperature. The decomposition products of polymelem were determined to be cyanoamide, dicyanoamide, and tricyanoamine. Tricyanoamine is the smallest carbon nitride molecule and has been experimentally confirmed for the first time in this study. When polymelem was decomposed in the presence of Raney nickel, homogenous NCNT with nitrogen content of ˜ 4--19 atom% was produced. A mechanism based on a detail analysis of the TEM images at different growth stages proposed that the NCNT propagated via a tip-growth mechanism originating at the nano-domains within the Raney nickel, and was accompanied with the aggregation of the nickel catalysts. Such NCNT exhibited a cup-stack wall structure paired with a compartmental feature. The nitrogen content, tube diameter and wall thickness greatly depended on synthesis conditions. The activated carbon derived from PEEK/PEI blend demonstrated a surface area up to ˜3000 m2/g, and average pore size of < 20 A. Such activated carbon exhibited a hydrogen storage capacity of up to 6.47 wt% at 40 bar, 77 K. The activated carbon has was incorporated with polymelem via a liquid penetration and a CVD method to modify its surface chemistry. The hydrogen adsorption energy of the polymelem doped activated carbon demonstrated a dramatic increase from ˜5 kJ/mol to ˜14 kJ/mol due to the higher polarizability of the polymelem.

2. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 1) ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 1) FROM THE 'CAMPUS' GROUNDS; LOOKING SW. (Harms) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

4. Historic American Buildings Survey, Arthur W. Stewart, Photographer September ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Historic American Buildings Survey, Arthur W. Stewart, Photographer September 10, 1936 WEST ELEVATION. - Washington Anderson House, Texas Route 79 at Northeast edge of Round Rock, Round Rock, Williamson County, TX

2. Historic American Buildings Survey, Arthur W. Stewart, Photographer September ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Historic American Buildings Survey, Arthur W. Stewart, Photographer September 10, 1936 SOUTHEAST ELEVATION. - Washington Anderson House, Texas Route 79 at Northeast edge of Round Rock, Round Rock, Williamson County, TX

77 FR 66865 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-07

... Williamson Rd. NE., Roanoke (Independent City), 12000968 Norfolk & Western Railway Freight Station, 303 Norfolk Ave., Roanoke (Independent City), 12000969 Rogers, Tayloe, House, 1542 Electric Rd., Roanoke...

Analysis of YBCO high temperature superconductor doped with silver nanoparticles and carbon nanotubes using Williamson-Hall and size-strain plot

NASA Astrophysics Data System (ADS)

Dadras, Sedigheh; Davoudiniya, Masoumeh

2018-05-01

This paper sets out to investigate and compare the effects of Ag nanoparticles and carbon nanotubes (CNTs) doping on the mechanical properties of Y1Ba2Cu3O7-δ (YBCO) high temperature superconductor. For this purpose, the pure and doped YBCO samples were synthesized by sol-gel method. The microstructural analysis of the samples is performed using X-ray diffraction (XRD). The crystalline size, lattice strain and stress of the pure and doped YBCO samples were estimated by modified forms of Williamson-Hall analysis (W-H), namely, uniform deformation model (UDM), uniform deformation stress model (UDSM) and the size-strain plot method (SSP). These results show that the crystalline size, lattice strain and stress of the YBCO samples declined by Ag nanoparticles and CNTs doping.

Importance of analytically verifying chemical treatments

USGS Publications Warehouse

Rach, J.J.; Gaikowski, M.P.; Olson, J.J.

1997-01-01

Hydrogen peroxide is considered a low regulatory priority compound by the U.S. Food and Drug Administration. It is used to control fungal infections on fish eggs. We studied the treatment profiles of hydrogen peroxide in Heath, McDonald egg jar, and Clark-Williamson incubators during treatments intended to deliver an effective regimen of at least 500 ??L hydrogen peroxide/L (i.e., treatments of 500 and 1,000 ??L/L) for 15 min. Hydrogen peroxide concentrations decreased with increasing distance from the influent water in both Heath and Clark-Williamson incubators. The top treatment tray (tray 2) of the Heath incubator received more than 90% of the intended regimen during the 500 ??L/L treatment, whereas at 1,000 ??L/L, all trays had hydrogen peroxide concentrations at or above 500 ??L/L for 15 min. None of the compartments in the Clark-Williamson incubator received the intended therapeutic regimen when treated at 500 ??L/L. The McDonald egg jar system distributed the intended concentration for the designated treatment period in all jars, except those located directly below the influent water. Our results indicate that dilution of therapeutants applied through certain egg incubation systems significantly decreases the efficacy of treatments and may render them ineffective. The dilution characteristics of egg incubation systems should be assessed in order to ensure proper delivery of all intended chemical concentrations and exposure regimens. Suggestions for maintaining the minimum effective concentrations in evaluated incubators are included.

Effect of silver doping on the elastic properties of CdS nanoparticles

NASA Astrophysics Data System (ADS)

Dey, P. C.; Das, R.

2018-05-01

CdS and Ag doped CdS (CdS/Ag) nanoparticles have been prepared via chemical method from a Cadmium acetate precursor and Thiourea. The synthesized CdS and CdS/Ag nanoparticles have been characterized by the X-ray Diffraction and High Resolution Transmission Electron Microscope. Here, these nanoparticles have been synthesized at room temperature and all the characterization have also been done at room temperature only. The XRD results reveal that the products are crystalline with cubic zinc blende structure. HRTEM images show that the prepared nanoparticles are nearly spherical in shape. Williamson-Hall method and Size-Strain Plot (SSP) have been used to study the individual contribution of crystalline sizes and lattice strain on the peak broadening of the CdS and CdS/Ag nanoparticles. The different modified model of Williamson-Hall method such as, uniform deformation model, uniform stress deformation model and uniform energy density deformation model and SSP method have been used to calculate the different physical parameter such as lattice strain, stress and energy density for all diffraction peaks of the XRD, corresponding to the CdS and silver doped CdS (CdS/Ag). The obtained results reveal that the average particle size of the prepared CdS and CdS/Ag nanoparticles estimated from the HRTEM images, Williamson-Hall analysis and SSP method are highly correlated with each other. Further, all these result confirms that doping of Ag significantly affects the elastic properties of CdS.

An extremely compensatible cigarette by design: documentary evidence on industry awareness and reactions to the Barclay filter design cheating the tar testing system.

PubMed

Kozlowski, L T; Dreschel, N A; Stellman, S D; Wilkenfeld, J; Weiss, E B; Goldberg, M E

2005-02-01

The Barclay cigarette (Brown & Williamson) was introduced in 1980 in the USA in the most expensive launch in history. In the USA and around the world, Barclay was later determined to have a grooved filter design that was compromised by human smokers in the normal act of smoking, but that was measured as ultra-low tar using the standard tar testing protocol. To evaluate whether Brown & Williamson knew of the compensatability of Barclay during the design process and before it was released; to evaluate initial responses of competing tobacco companies to Barclay, before complaints were made to the Federal Trade Commission in 1981. Internet databases of industry documents (Tobacco Documents Online, Legacy Tobacco Documents Library, Brown & Williamson Litigation discovery website, Guildford and major company websites) were searched using key words, key dates, and targeted searches. Documents related specifically to the development, evaluation and release of the Barclay cigarette and related to the responses by competing tobacco companies were examined. Documents indicate the manufacturer was aware of Barclay design problems and was planning, before release, to respond to criticism. Competing companies quickly detected the filter groove stratagem and considered developing their own similar filter, but eventually backed off. The design problems with Barclay were readily understood by cigarette manufacturers, including the maker of Barclay, before official governmental evaluations occurred. Testing involving measured exposures to human smokers may in the end be crucial to identifying problems with novel cigarette designs.

Synthesis of Strained 1,3-Diene Macrocycles via Copper-Mediated Castro-Stephens Coupling/Alkyne Reduction Tandem Reactions.

PubMed

Li, Wei; Schneider, Christopher M; Georg, Gunda I

2015-08-07

A copper-mediated macrocyclization involving the reaction of a vinyl iodide and a terminal alkyne followed by an in situ reduction of the enyne intermediate is reported. The reaction generates a conjugated Z-double bond within a strained medium-size lactone, lactam, or ether macrocycle. A variety of macrocyclic compounds bearing different ring sizes and functionalities were synthesized. A complementary stepwise procedure was also developed for less strained ring systems.

Crystallization process of zeolite rho prepared by hydrothermal synthesis using 18-crown-6 ether as organic template.

PubMed

Araki, Sadao; Kiyohara, Yasato; Tanaka, Shunsuke; Miyake, Yoshikazu

2012-06-15

There are many viewpoints on the formation mechanisms for zeolites, but the details are not clear. An understanding of the elementary steps for their formation is important for the development of large-scale membranes and efficient manufacturing processes. In this study, the effects of silicon, aluminum, and the incorporation of 18-crown-6 (18C6) ether, on the formation of zeolite rho, using 18C6 as the structure directing agent (SDA) have been investigated by using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray fluorescence spectrometry (EDX), nuclear magnetic resonance spectroscopy (NMR), thermo gravimetric analysis (TGA), and the pH measurement. These results suggested that a zeolite rho has four synthesis steps; (1) 0-3 h, the dehydration and condensation reaction between the silica and alumina to form amorphous aluminosilicates; (2) 3-20 h, the particle growth and aggregation process for the amorphous aluminosilicates; (3) 20-48 h, the crystallization and crystal growth of zeolite rho, with the incorporation of 18C6; and (4) 48-96 h, gentle growth with an increase in Na/Si ratio and a change in rate for the bounding state between the silica- and the alumina-based species. We consider the above to reflect the four steps for the formation of zeolite rho. Copyright © 2012 Elsevier Inc. All rights reserved.

Taming the Reactivity of Glycosyl Iodides To Achieve Stereoselective Glycosidation.

PubMed

Gervay-Hague, Jacquelyn

2016-01-19

Although glycosyl iodides have been known for more than 100 years, it was not until the 21st century that their full potential began to be harnessed for complex glycoconjugate synthesis. Mechanistic studies in the late 1990s probed glycosyl iodide formation by NMR spectroscopy and revealed important reactivity features embedded in protecting-group stereoelectronics. Differentially protected sugars having an anomeric acetate were reacted with trimethylsilyl iodide (TMSI) to generate the glycosyl iodides. In the absence of C-2 participation, generation of the glycosyl iodide proceeded by inversion of the starting anomeric acetate stereochemistry. Once formed, the glycosyl iodide readily underwent in situ anomerization, and in the presence of excess iodide, equilibrium concentrations of α- and β-iodides were established. Reactivity profiles depended upon the identity of the sugar and the protecting groups adorning it. Consistent with the modern idea of disarmed versus armed sugars, ester protecting groups diminished the reactivity of glycosyl iodides and ether protecting groups enhanced the reactivity. Thus, acetylated sugars were slower to form the iodide and anomerize than their benzylated analogues, and these disarmed glycosyl iodides could be isolated and purified, whereas armed ether-protected iodides could only be generated and reacted in situ. All other things being equal, the β-iodide was orders of magnitude more reactive than the thermodynamically more stable α-iodide, consistent with the idea of in situ anomerization introduced by Lemieux in the mid-20th century. Glycosyl iodides are far more reactive than the corresponding bromides, and with the increased reactivity comes increased stereocontrol, particularly when forming α-linked linear and branched oligosaccharides. Reactions with per-O-silylated glycosyl iodides are especially useful for the synthesis of α-linked glycoconjugates. Silyl ether protecting groups make the glycosyl iodide so reactive that even highly functionalized aglycon acceptors add. Following the coupling event, the TMS ethers are readily removed by methanolysis, and since all of the byproducts are volatile, multiple reactions can be performed in a single reaction vessel without isolation of intermediates. In this fashion, per-O-TMS monosaccharides can be converted to biologically relevant α-linked glycolipids in one pot. The stereochemical outcome of these reactions can also be switched to β-glycoside formation by addition of silver to chelate the iodide, thus favoring SN2 displacement of the α-iodide. While iodides derived from benzyl and silyl ether-protected oligosaccharides are susceptible to interglycosidic bond cleavage when treated with TMSI, the introduction of a single acetate protecting group prevents this unwanted side reaction. Partial acetylation of armed glycosyl iodides also attenuates HI elimination side reactions. Conversely, fully acetylated glycosyl iodides are deactivated and require metal catalysis in order for glycosidation to occur. Recent findings indicate that I2 activation of per-O-acetylated mono-, di-, and trisaccharides promotes glycosidation of cyclic ethers to give β-linked iodoalkyl glycoconjugates in one step. Products of these reactions have been converted into multivalent carbohydrate displays. With these synthetic pathways elucidated, chemical reactivity can be exquisitely controlled by the judicious selection of protecting groups to achieve high stereocontrol in step-economical processes.

Oxygenates vs. synthesis gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamil Klier; Richard G. Herman; Alessandra Beretta

1999-04-01

Methanol synthesis from H{sub 2}/CO has been carried out at 7.6 MPa over zirconia-supported copper catalysts. Catalysts with nominal compositions of 10/90 mol% and 30/70 mol% Cu/ZrO{sub 2} were used in this study. Additionally, a 3 mol% cesium-doped 10/90 catalyst was prepared to study the effect of doping with heavy alkali, and this promoter greatly increased the methanol productivity. The effects of CO{sub 2} addition, water injection, reaction temperature, and H{sub 2}/C0 ratio have been investigated. Both CO{sub 2} addition to the synthesis gas and cesium doping of the catalyst promoted methanol synthesis, while inhibiting the synthesis of dimethyl ether.more » Injection of water, however, was found to slightly suppress methanol and dimethyl ether formation while being converted to CO{sub 2} via the water gas shift reaction over these catalysts. There was no clear correlation between copper surface area and catalyst activity. Surface analysis of the tested samples revealed that copper tended to migrate and enrich the catalyst surface. The concept of employing a double-bed reactor with a pronounced temperature gradient to enhance higher alcohol synthesis was explored, and it was found that utilization of a Cs-promoted Cu/ZnO/Cr{sub 2}O{sub 3} catalyst as a first lower temperature bed and a Cs-promoted ZnO/Cr{sub 2}O{sub 3} catalyst as a second high-temperature bed significantly promoted the productivity of 2-methyl-1-propanol (isobutanol) from H{sub 2}/CO synthesis gas mixtures. While the conversion of CO to C{sub 2+} oxygenates over the double-bed configuration was comparable to that observed over the single Cu-based catalyst, major changes in the product distribution occurred by the coupling to the zinc chromite catalyst; that is, the productivity of the C{sub 1}-C{sub 3} alcohols decreased dramatically, and 2-methyl branched alcohols were selectively formed. The desirable methanol/2-methyl oxygenate molar ratios close to 1 were obtained in the present double-bed system that provides the feedstock for the synthesis of high octane and high cetane ethers, where the isobutanol productivity was as high as 139 g/kg cat/hr. Higher alcohol synthesis has been investigated over a Cs/Cu/ZnO/Cr{sub 2}O{sub 3} catalyst at temperatures higher (up to 703K) than those previously utilized, and no sintering of the catalyst was observed during the short-term testing. However, the higher reaction temperatures led to lower CO conversion levels and lower yield of alcohols, especially of methanol, because of equilibrium limitations. With the double catalyst bed configuration, the effect of pressure in the range of 7.6--12.4 MPa on catalyst activity and selectivity was studied. The upper bed was composed of the copper-based catalyst at 598K, and the lower bed consisted of a copper-free Cs-ZnO/Cr{sub 2}O{sub 3} catalyst at a high temperature of 678K. High pressure was found to increase CO conversion to oxygenated products, although the increase in isobutanol productivity did not keep pace with that of methanol. It was also shown that the Cs/Cu/ZnO/Cr{sub 2}O{sub 3} catalyst could be utilized to advantage as the second-bed catalyst at 613--643K instead of the previously used copper-free Cs-ZnO/ Cr{sub 2}O{sub 3} catalyst at higher temperature, With double Cs/Cu/ZnO/Cr{sub 2}O{sub 3} catalysts, high space time yields of up to 202 g/kg cat/hr, with high selectivity to isobutanol, were achieved.« less

35. Basement, passage beneath main entrance porch, showing circular skylight ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. Basement, passage beneath main entrance porch, showing circular skylight opening, view to northwest - Portsmouth Naval Hospital, Hospital Building, Rixey Place, bounded by Williamson Drive, Holcomb Road, & The Circle, Portsmouth, Portsmouth, VA

17. First floor, dining room showing fireplace and china press, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. First floor, dining room showing fireplace and china press, view to southeast - Portsmouth Naval Hospital, Medical Officer's Quarters C, West side Williamson Drive, 400 feet South of Rixey Drive, Portsmouth, Portsmouth, VA

12. DETAIL VIEW OF DEDICATION PLAQUE & ITS SURROUNDING TABERNACLE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. DETAIL VIEW OF DEDICATION PLAQUE & ITS SURROUNDING TABERNACLE FRAME; MAIN LOBBY OF BUILDING 1, LOOKING E. (Ryan) - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

4. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 & BUILDING 1) FROM THE 'CAMPUS' GROUNDS; LOOKING NE. (Harms) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

3. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 & BUILDING 1) FROM THE 'CAMPUS' GROUNDS; LOOKING NW. (Harms) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

1. Historic American Buildings Survey, Arthur W. Stewart, Photographer September ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Historic American Buildings Survey, Arthur W. Stewart, Photographer September 10, 1936 SOUTH ELEVATION (FRONT). - Washington Anderson House, Texas Route 79 at Northeast edge of Round Rock, Round Rock, Williamson County, TX

3. Historic American Buildings Survey, Arthur W. Stewart, Photographer September ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Historic American Buildings Survey, Arthur W. Stewart, Photographer September 10, 1936 NORTH ELEVATION (REAR). - Washington Anderson House, Texas Route 79 at Northeast edge of Round Rock, Round Rock, Williamson County, TX

GENERAL VIEW OF NORTH SAN GABRIEL RIVER BRIDGE, NORTH APPROACH, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GENERAL VIEW OF NORTH SAN GABRIEL RIVER BRIDGE, NORTH APPROACH, LOOKING SOUTH. - North San Gabriel River Bridge, Spanning North Fork of San Gabriel River at Business Route 35, Georgetown, Williamson County, TX

GENERAL VIEW OF NORTH SAN GABRIEL RIVER BRIDGE, NORTH ABUTMENT, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GENERAL VIEW OF NORTH SAN GABRIEL RIVER BRIDGE, NORTH ABUTMENT, LOOKING NORTHWEST. - North San Gabriel River Bridge, Spanning North Fork of San Gabriel River at Business Route 35, Georgetown, Williamson County, TX

DETAIL OF NORTH SAN GABRIEL RIVER BRIDGE, PICKET HAND RAIL, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF NORTH SAN GABRIEL RIVER BRIDGE, PICKET HAND RAIL, LOOKING WEST. - North San Gabriel River Bridge, Spanning North Fork of San Gabriel River at Business Route 35, Georgetown, Williamson County, TX

DETAIL OF NORTH SAN GABRIEL RIVER BRIDGE, CANTILEVER SPAN CONNECTION, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF NORTH SAN GABRIEL RIVER BRIDGE, CANTILEVER SPAN CONNECTION, LOOKING SOUTHEAST. - North San Gabriel River Bridge, Spanning North Fork of San Gabriel River at Business Route 35, Georgetown, Williamson County, TX

GENERAL VIEW OF NORTH SAN GABRIEL RIVER BRIDGE, EAST SIDE, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GENERAL VIEW OF NORTH SAN GABRIEL RIVER BRIDGE, EAST SIDE, LOOKING SOUTHWEST. - North San Gabriel River Bridge, Spanning North Fork of San Gabriel River at Business Route 35, Georgetown, Williamson County, TX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teka, S.; Gaied, A.; Jaballah, N.

Highlights: • Microwave-assisted synthesis of rotaxane based on anthracene and β-cyclodextrin. • Morphological and optical characterization of thin solid film. • Elaboration of impedimetric gold/rotaxane sensor. • Investigation of the membrane sensitivity towards Hg{sup 2+}, Cu{sup 2+} and Pb{sup 2+} cations. - Abstract: An impedimetric sensor based on a new semi-conducting rotaxane has been described for detection of toxic cations. The rotaxane, consists on a π-conjugated material encapsulated into β-cyclodextrin (β-CD); it has been synthesized via the Williamson reaction under microwaves irradiation. The supramolecular structure of the compound was confirmed by NMR and FT-IR spectroscopies. A thin solid film ofmore » the rotaxane was deposited by spin-coating to develop a new electrochemical sensor. The morphological properties of the organic membrane were evaluated using contact angle measurements and atomic force microscopy. The gold/rotaxane/solution interfaces were investigated by electrochemical impedance spectroscopy and the obtained data were fitted using an equivalent electrical circuit. The response of the gold/rotaxane membrane towards Hg{sup 2+}, Cu{sup 2+} and Pb{sup 2+} cations was studied and the results showed a good sensitivity to the mercury cations.« less

Cobalt-doped nanohydroxyapatite: synthesis, characterization, antimicrobial and hemolytic studies

NASA Astrophysics Data System (ADS)

Tank, Kashmira P.; Chudasama, Kiran S.; Thaker, Vrinda S.; Joshi, Mihir J.

2013-05-01

Hydroxyapatite (Ca10(PO4)6(OH)2; HAP) is a major mineral component of the calcified tissues, and it has various applications in medicine and dentistry. In the present investigation, cobalt-doped hydroxyapatite (Co-HAP) nanoparticles were synthesized by surfactant-mediated approach and characterized by different techniques. The EDAX was carried out to estimate the amount of doping in Co-HAP. The transmission electron microscopy result suggested the transformation of morphology from needle shaped to spherical type on increasing the doping concentration. The powder XRD study indicated the formation of a new phase of brushite for higher concentration of cobalt. The average particle size and strain were calculated using Williamson-Hall analysis. The average particle size was found to be 30-60 nm. The FTIR study confirmed the presence of various functional groups in the samples. The antimicrobial activity was evaluated against four organisms Pseudomonas aeruginosa and Shigella flexneri as Gram negative as well as Micrococcus luteus and Staphylococcus aureus as Gram positive. The hemolytic test result suggested that all samples were non-hemolytic. The photoluminescence study was carried out to identify its possible applicability as a fluorescent probe.

Synthesis and Properties of Poly(ether sulfone)s with Clustered Sulfonic Groups for PEMFC Applications under Various Relative Humidity.

PubMed

Lee, Shih-Wei; Chen, Jyh-Chien; Wu, Jin-An; Chen, Kuei-Hsien

2017-03-22

Novel sulfonated poly(ether sulfone) copolymers (S4PH-x-PSs) based on a new aromatic diol containing four phenyl substituents at the 2, 2', 6, and 6' positions of 4,4'-diphenyl ether were synthesized. Sulfonation was found to occur exclusively on the 4 position of phenyl substituents by NMR spectroscopy. The ion exchange capacity (IEC) values can be controlled by adjusting the mole percent (x in S4PH-x-PS) of the new diol. The fully hydrated sulfonated poly(ether sulfone) copolymers had good proton conductivity in the range 0.004-0.110 S/cm at room temperature. The surface morphology of S4PH-x-PSs and Nafion 212 was investigated by atomic force microscopy (tapping-mode) and related to the percolation limit and proton conductivity. Single H 2 /O 2 fuel cell based on S4PH-40-PS loaded with 0.25 mg/cm 2 catalyst (Pt/C) exhibited a peak power density of 462.6 mW/cm 2 , which was close to that of Nafion 212 (533.5 mW/cm 2 ) at 80 °C with 80% RH. Furthermore, fuel cell performance of S4PH-35-PS with various relative humidity was investigated. It was confirmed from polarization curves that the fuel cell performance of S4PH-35-PS was not as high as that of Nafion 212 under fully hydrated state due to higher interfacial resistance between S4PH-35-PS and electrodes. While under low relative humidity (53% RH) at 80 °C, fuel cells based on S4PH-35-PS showed higher peak power density (234.9 mW/cm 2 ) than that (214.0 mW/cm 2 ) of Nafion 212.

DETAIL OF SOUTH SAN GABRIEL RIVER BRIDGE, CANTILEVER SPAN CONNECTION, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF SOUTH SAN GABRIEL RIVER BRIDGE, CANTILEVER SPAN CONNECTION, LOOKING NORTHWEST. - South San Gabriel River Bridge, Spanning South Fork of San Gabriel River at Georgetown at Business Route 35, Georgetown, Williamson County, TX

DETAIL OF SOUTH SAN GABRIEL RIVER BRIDGE, BUILDER’S PLATE, LOOKING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF SOUTH SAN GABRIEL RIVER BRIDGE, BUILDER’S PLATE, LOOKING NORTHEAST. - South San Gabriel River Bridge, Spanning South Fork of San Gabriel River at Georgetown at Business Route 35, Georgetown, Williamson County, TX

GENERAL VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, RIVER SPAN, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GENERAL VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, RIVER SPAN, LOOKING NORTHWEST. - South San Gabriel River Bridge, Spanning South Fork of San Gabriel River at Georgetown at Business Route 35, Georgetown, Williamson County, TX

GENERAL VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, WEST SIDE, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GENERAL VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, WEST SIDE, LOOKING EAST. - South San Gabriel River Bridge, Spanning South Fork of San Gabriel River at Georgetown at Business Route 35, Georgetown, Williamson County, TX

GENERAL VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, SOUTH ABUTMENT, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GENERAL VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, SOUTH ABUTMENT, LOOKING SOUTHWEST. - South San Gabriel River Bridge, Spanning South Fork of San Gabriel River at Georgetown at Business Route 35, Georgetown, Williamson County, TX

GENERAL VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, SOUTH APPROACH, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GENERAL VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, SOUTH APPROACH, LOOKING NORTH. - South San Gabriel River Bridge, Spanning South Fork of San Gabriel River at Georgetown at Business Route 35, Georgetown, Williamson County, TX

DETAIL OF SOUTH SAN GABRIEL RIVER BRIDGE, PICKET HAND RAIL, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF SOUTH SAN GABRIEL RIVER BRIDGE, PICKET HAND RAIL, LOOKING WEST. - South San Gabriel River Bridge, Spanning South Fork of San Gabriel River at Georgetown at Business Route 35, Georgetown, Williamson County, TX

VIEW OF NORTH SAN GABRIEL RIVER BRIDGE, FLOOR SYSTEM AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF NORTH SAN GABRIEL RIVER BRIDGE, FLOOR SYSTEM AND LATERAL BRACING, LOOKING SOUTH. - North San Gabriel River Bridge, Spanning North Fork of San Gabriel River at Business Route 35, Georgetown, Williamson County, TX

Synthetic versatility of 2-substituted-6-methyl 2,3-dihydropyridinones in the synthesis of polyfunctional piperidine-based compounds and related β amino acid derivatives.

PubMed

Yang, Yang; Hardman, Clayton

2017-10-18

Chiral 2-substituted-6-methyl 2,3-dihydropyidinones 9, which can be facilely obtained from an asymmetric vinylogous Mannich reaction (VMR) with 1,3-bis-trimethysily enol ether, were used as versatile intermediates in constructing chiral polyfunctional piperidine-based compounds. The 6-methyl group of such compounds can be conveniently functionalized via alkylation and acylation reactions to provide efficient entries to the synthesis of a variety of chiral multi-substituted piperidine-based compounds. Further elaboration of the corresponding intermediates also provided access to polyfunctional indolizidine-based compounds. These methods were showcased in an asymmetric synthesis of 2,6-di-substituted piperidine compound 13, reported as the key intermediate in the synthesis of (+)-calvine and a natural alkaloid (-)-indolizidine 209D. Furthermore, selective C5 iodination of compound 9 enabled the installation of additional functional groups at this position. Finally, we demonstrated that the oxidative cleavage of 2-substituted-6-methyl-2,3-dihydropyidinones is a practical and efficient method for the enantioselective synthesis of β-amino acids, which can undergo further intra-molecular cyclization to give the corresponding chiral four-membered β-lactam derivatives.

Evidence, illness, and causation: an epidemiological perspective on the Russo-Williamson Thesis.

PubMed

Fiorentino, Alexander R; Dammann, Olaf

2015-12-01

According to the Russo-Williamson Thesis, causal claims in the health sciences need to be supported by both difference-making and mechanistic evidence. In this article, we attempt to determine whether Evidence-based Medicine (EBM) can be improved through the consideration of mechanistic evidence. We discuss the practical composition and function of each RWT evidence type and propose that exposure-outcome evidence (previously known as difference-making evidence) provides associations that can be explained through a hypothesis of causation, while mechanistic evidence provides finer-grained associations and knowledge of entities that ultimately explains a causal hypothesis. We suggest that mechanistic evidence holds untapped potential to add value to the assessment of evidence quality in EBM and propose initial recommendations for the integration of mechanistic and exposure-outcome evidence to improve EBM by robustly leveraging available evidence in support of good medical decisions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Heat and mass transfer of Williamson nanofluid flow yield by an inclined Lorentz force over a nonlinear stretching sheet

NASA Astrophysics Data System (ADS)

Khan, Mair; Malik, M. Y.; Salahuddin, T.; Hussian, Arif.

2018-03-01

The present analysis is devoted to explore the computational solution of the problem addressing the variable viscosity and inclined Lorentz force effects on Williamson nanofluid over a stretching sheet. Variable viscosity is assumed to vary as a linear function of temperature. The basic mathematical modelled problem i.e. system of PDE's is converted nonlinear into ODE's via applying suitable transformations. Computational solutions of the problem is also achieved via efficient numerical technique shooting. Characteristics of controlling parameters i.e. stretching index, inclined angle, Hartmann number, Weissenberg number, variable viscosity parameter, mixed convention parameter, Brownian motion parameter, Prandtl number, Lewis number, thermophoresis parameter and chemical reactive species on concentration, temperature and velocity gradient. Additionally, friction factor coefficient, Nusselt number and Sherwood number are describe with the help of graphics as well as tables verses flow controlling parameters.

Relationship between structure and antiproliferative activity of 1-azaflavanones.

PubMed

Kawaii, Satoru; Endo, Kotaro; Tokiwano, Tetsuo; Yoshizawa, Yuko

2012-07-01

The synthesis of 19 derivatives of 2-phenyl-3,4-dihydroquinolin-4(1H)-one, as aza analogs of flavanones, was carried out and these compounds were further screened for their antiproliferative activity toward HL60 promyelocytic leukemia cells. In comparison with flavanone the replacement of C-ring ether oxygen atom with a nitrogen atom potentiated activity by more than 100-fold. It was suggested that the aromaticity of the B-ring contributes greatly to the activity of 1-azaflavanones.

New halogenated phenylcoumarins as tyrosinase inhibitors.

PubMed

Matos, Maria João; Santana, Lourdes; Uriarte, Eugenio; Delogu, Giovanna; Corda, Marcella; Fadda, Maria Benedetta; Era, Benedetta; Fais, Antonella

2011-06-01

With the aim to find out structural features for the tyrosinase inhibitory activity, in the present communication we report the synthesis and pharmacological evaluation of a new series of phenylcoumarin derivatives with different number of hydroxyl or ether groups and bromo substituent in the scaffold. The synthesized compounds 5-12 were evaluated as mushroom tyrosinase inhibitors showing, two of them, lower IC(50) than the umbelliferone. Compound 12 (IC(50)=215 μM) is the best tyrosinase inhibitor of this series. Copyright © 2011 Elsevier Ltd. All rights reserved.

Synthesis and Photolysis of Model Compounds for Mechanistic Studies of 1,3,5-Trinitro-1,3,5-Triazacyclohexane (RDX) Decomposition.

DTIC Science & Technology

1978-06-01

However, once irradiation was stopped the radical disappeared within a half hour . When the temperature was Increased to 40 °C the radical existed...and Russat proposed that the mechanism is bimolecular with the products OK - . ‘ being the nitrone and hydroxy l amine. Experimenta l support for this...process was provided by K. U. Ingold 15 . Kaminsky and Lamchen 16 and ethers have shown that the photolysis of cyclic nitrones gives oxi- ziridines

Feasibility of Biomonitoring of Exposure to Permethrin Through Analysis of Long-Lived (Metabolite) Adducts to Proteins

DTIC Science & Technology

2007-09-01

Preparation of the Grignard reagent To flask E, containing magnesium (52 mg, 2 mmol) and a few crystals of iodine was added a solution of 3...bromodiphenylether (750 mg, 3 mmol) in diethyl ether (3 mL). The entire system was kept under nitrogen. The preparation of the Grignard reagent was initiated by...device represented below was used for the multi-step synthesis of 3-PBA; all reagents were present in the manifold prior to the beginning of the

Microwave-Assisted Organocatalytic Intramolecular Knoevenagel/Hetero Diels-Alder Reaction with O-(Arylpropynyloxy)-Salicylaldehydes: Synthesis of Polycyclic Embelin Derivatives.

PubMed

Martín-Acosta, Pedro; Feresin, Gabriela; Tapia, Alejandro; Estévez-Braun, Ana

2016-10-21

A highly efficient and regioselective approach to new polycyclic embelin derivatives through a domino Knoevenagel condensation/intramolecular hetero Diels-Alder reaction using O-(arylpropynyloxy)-salicylaldehydes in the presence of ethylenediamine diacetate (EDDA) is reported. This organocatalyzed protocol is compatible toward a wide range of aryl-substituted alkynyl ethers with electron-donating and electron-withdrawing groups. When other active methylene compounds were subjected to this domino reaction the corresponding adducts were obtained in high yield.

Studies toward the synthesis of palhinine lycopodium alkaloids: a Morita-Baylis-Hillman/intramolecular Diels-Alder approach.

PubMed

Sizemore, Nicholas; Rychnovsky, Scott D

2014-02-07

A synthetic route to the isotwistane core of palhinine lycopodium alkaloids is described. A Morita-Baylis-Hillman/intramolecular Diels-Alder (IMDA) strategy sets the vicinal all-carbon quaternary centers present in this family of natural products. The regioselectivity of the IMDA reaction is dictated by the conditions employed for silyl enol ether formation, with one set of conditions providing the core of cardionine and alternate conditions generating the desired isotwistane core of isopalhinine.

A Rapid, One-Pot Synthesis of β-Siloxy-α-Haloaldehydes

PubMed Central

Saadi, Jakub; Akakura, Matsujiro

2011-01-01

The Mukaiyama cross aldol reaction of α-fluoro-, α-chloro-, and α-bromoacetaldehyde-derived (Z)-tris(trimethylsilyl)- silyl enol ethers furnishing anti-β-siloxy-α-haloaldehydes is described. A highly diastereoselective, one-pot, sequential double aldol process, affording novel β,δ-bissiloxy-α,γ-bishaloaldehydes is developed. Reactions are catalyzed by C6F5CHTf2 and C6F5CTf2AlMe2 (0.5–1.5 mol%) and provide access to halogenated polyketide fragments. PMID:21815682

Alkali or alkaline earth metal promoted catalyst and a process for methanol synthesis using alkali or alkaline earth metals as promoters

DOEpatents

Tierney, J.W.; Wender, I.; Palekar, V.M.

1995-01-31

The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a heterogeneous catalyst comprising reduced copper chromite impregnated with an alkali or alkaline earth metal. There is thus no need to add a separate alkali or alkaline earth compound. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100--160 C and the pressure range of 40--65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H[sub 2]/CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

Alkali or alkaline earth metal promoted catalyst and a process for methanol synthesis using alkali or alkaline earth metals as promoters

DOEpatents

Tierney, John W.; Wender, Irving; Palekar, Vishwesh M.

1995-01-01

The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a heterogeneous catalyst comprising reduced copper chromite impregnated with an alkali or alkaline earth metal. There is thus no need to add a separate alkali or alkaline earth compound. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100.degree.-160.degree. C. and the pressure range of 40-65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H.sub.2 /CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

Synthesis and foaming properties of new anionic surfactants based on a renewable building block: sodium dodecyl isosorbide sulfates.

PubMed

Lavergne, Aurélie; Zhu, Ying; Pizzino, Aldo; Molinier, Valérie; Aubry, Jean-Marie

2011-08-15

Two agro-based anionic surfactants containing an isosorbide moiety have been synthesized and their amphiphilic properties evaluated. Since isosorbide is now considered as an important platform chemical of the starch industry, these compounds could represent bio-sourced alternatives to the alkyl ether sulfates (notably lauryl ether sulfate, LES) that are based on petroleum-derived ethylene oxides. As isosorbide is an asymmetric diol, two isomers can be prepared (2-O-dodecyl isosorbide sulfate and 5-O-dodecyl isosorbide sulfate) that show significantly different aqueous properties as regards to their Krafft temperatures and critical micellar concentrations. 5-O-dodecyl isosorbide sulfate is the most soluble and the most efficient surfactant. It possesses a much lower critical micelle concentration (cmc) than sodium dodecyl sulfate, SDS, leading to comparable foaming properties with a three times lower concentration. Its behavior compares well with the one of pure diethoxylated dodecyl sulfate that has also been prepared and evaluated in this work. Copyright © 2011 Elsevier Inc. All rights reserved.

Synthesis and evaluation of 7-substituted 4-aminoquinoline analogues for antimalarial activity.

PubMed

Hwang, Jong Yeon; Kawasuji, Takashi; Lowes, David J; Clark, Julie A; Connelly, Michele C; Zhu, Fangyi; Guiguemde, W Armand; Sigal, Martina S; Wilson, Emily B; Derisi, Joseph L; Guy, R Kiplin

2011-10-27

We previously reported that substituted 4-aminoquinolines with a phenyl ether substituent at the 7-position of the quinoline ring and the capability of intramolecular hydrogen bonding between the protonated amine on the side chain and a hydrogen bond acceptor on the amine's alkyl substituents exhibited potent antimalarial activity against the multidrug resistant strain P. falciparum W2. We employed a parallel synthetic method to generate diaryl ether, biaryl, and alkylaryl 4-aminoquinoline analogues in the background of a limited number of side chain variations that had previously afforded potent 4-aminoquinolines. All subsets were evaluated for their antimalarial activity against the chloroquine-sensitive strain 3D7 and the chloroquine-resistant K1 strain as well as for cytotoxicity against mammalian cell lines. While all three arrays showed good antimalarial activity, only the biaryl-containing subset showed consistently good potency against the drug-resistant K1 strain and good selectivity with regard to mammalian cytotoxicity. Overall, our data indicate that the biaryl-containing series contains promising candidates for further study.

Densities and viscosities for binary mixtures of N-methyldiethanolamine + triethylene glycol monomethyl ether from 25 C to 70 C and N-methyldiethanolamine + ethanol mixtures at 40 C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henni, A.; Maham, Y.; Tontiwachwuthikul, P.

2000-04-01

Recent studies done on the absorption and desorption of acid gases (CO{sub 2}, H{sub 2}S) from natural gas, petroleum, and ammonia synthesis streams have shown that aqueous solutions of N-methyldiethanolamine (MDEA) can be used effectively for the selective removal of H{sub 2}S. This paper reports the measured values of the density and viscosity of binary mixtures of N-methyldiethanolamine (MDEA) and triethylene glycol monomethyl ether (TEGMME) at five temperatures in the range 25 C to 70 C over the whole concentration range. The authors also report the density and viscosity of the binary mixture MDEA + ethanol at 40 C. Themore » results are compared with data for aqueous mixtures and other alkanolamines when these are available. The derived excess molar volumes and viscosity deviations were correlated as a function of composition. The Grunberg-Nissan interaction energy constants are also reported.« less

Hydroperoxide Traces in Common Cyclic Ethers as Initiators for Controlled RAFT Polymerizations.

PubMed

Eggers, Steffen; Abetz, Volker

2018-04-01

Herein, a reversible addition-fragmentation chain transfer (RAFT) polymerization is introduced for reactive monomers like N-acryloylpyrrolidine or N,N-dimethylacrylamide working without a conventional radical initiator. As a very straightforward proof of principle, the method takes advantage of the usually inconvenient radical-generating hydroperoxide contaminations in cyclic ethers like tetrahydrofuran or 1,4-dioxane, which are very common solvents in polymer sciences. The polymerizations are surprisingly well controlled and the polymers can be extended with a second block, indicating their high livingness. "Solvent-initiated" RAFT polymerizations hence prove to be a feasible access to tailored materials with minimal experimental effort and standard laboratory equipment, only requiring the following ingredients: hydroperoxide-contaminated solvent, monomer, and RAFT agent. In other respects, however, the potential coinitiating ability of the used solvent is to be considered when investigating the kinetics of RAFT polymerizations or aiming for the synthesis of high-livingness polymers, e.g., multiblock copolymers. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design and synthesis of potent antileishmanial cycloalkylidene-substituted ether phospholipid derivatives.

PubMed

Calogeropoulou, Theodora; Angelou, Panagiotis; Detsi, Anastasia; Fragiadaki, Irene; Scoulica, Effie

2008-02-28

Two series of novel ether phospholipids (EPs) have been synthesized. The first includes cyclodecylidene- or cyclopentadecylidene-substituted EPs carrying N,N,N-trimethylammonium or N-methylpiperidino or N-methylmorpholino head groups. The second series encompasses more rigid head groups in combination with cycloalkylidene moieties in the lipid portion. In addition, hydrogenated derivatives were obtained. All the new analogues, except 33, were 1.5- to 62-fold more potent than miltefosine against the intracellular L. infantum, and the most active ones were also less cytotoxic against the human monocytic cell line THP1 and less hemolytic than miltefosine. The analogues that combine high potency with low cytotoxicity and hemolytic activity were 19, 37, 21 23, 38, 39, and 40. Cyclopentadecylpentylphosphocholine (38) possesses an IC50 of 0.7 microM against L. infantum amastigotes and is the least cytotoxic analogue, since it does not present toxicity against THP1 macrophages, even at a concentration that is 800-fold the antiparasitic IC50 value, and does not present significant hemolytic activity.

An extremely compensatible cigarette by design: documentary evidence on industry awareness and reactions to the Barclay filter design cheating the tar testing system

PubMed Central

Kozlowski, L; Dreschel, N; Stellman, S; Wilkenfeld, J; Weiss, E; Goldberg, M

2005-01-01

Background: The Barclay cigarette (Brown & Williamson) was introduced in 1980 in the USA in the most expensive launch in history. In the USA and around the world, Barclay was later determined to have a grooved filter design that was compromised by human smokers in the normal act of smoking, but that was measured as ultra-low tar using the standard tar testing protocol. Objectives: To evaluate whether Brown & Williamson knew of the compensatability of Barclay during the design process and before it was released; to evaluate initial responses of competing tobacco companies to Barclay, before complaints were made to the Federal Trade Commission in 1981. Methods: Internet databases of industry documents (Tobacco Documents Online, Legacy Tobacco Documents Library, Brown & Williamson Litigation discovery website, Guildford and major company websites) were searched using key words, key dates, and targeted searches. Documents related specifically to the development, evaluation and release of the Barclay cigarette and related to the responses by competing tobacco companies were examined. Results: Documents indicate the manufacturer was aware of Barclay design problems and was planning, before release, to respond to criticism. Competing companies quickly detected the filter groove stratagem and considered developing their own similar filter, but eventually backed off. Conclusion: The design problems with Barclay were readily understood by cigarette manufacturers, including the maker of Barclay, before official governmental evaluations occurred. Testing involving measured exposures to human smokers may in the end be crucial to identifying problems with novel cigarette designs. PMID:15735303

Predation on larval suckers in the Williamson River Delta revealed by molecular genetic assays—A pilot study

USGS Publications Warehouse

Hereford, Danielle M.; Ostberg, Carl O.; Burdick, Summer M.

2016-06-13

Predation of endangered Lost River suckers (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) during larval egress to Upper Klamath Lake from the Williamson River is poorly understood but may be an important factor limiting recruitment into adult spawning populations. Native and non-native piscivores are abundant in nursery wetland habitat, but larval predation has not been directly studied for all species. Larvae lack hard body structures and digest rapidly in predator digestive systems. Therefore, traditional visual methods for diet analysis may fail to identify the extent of predation on larvae. The goals of this study were to (1) use quantitative polymerase chain reaction (qPCR) and single nucleotide polymorphism (SNP) assays developed for Lost River and shortnose suckers to assay predator stomach contents for sucker DNA, and (2) to assess our ability to use this technique to study predation. Predators were captured opportunistically during larval sucker egress. Concurrent feeding trials indicate that most predators—yellow perch (Perca flaverscens), fathead minnow (Pimephales promelas), blue chub (Gila coerulea), Klamath tui chub (Siphatales bicolor bicolor), Klamath Lake sculpin (Cottus princeps), slender sculpin (Cottus tenuis)—preyed on sucker larvae in the laboratory. However, sucker DNA was not detected in fathead minnow stomachs. Of the stomachs screened from fish captured in the Williamson River Delta, 15.6 percent of yellow perch contained sucker DNA. This study has demonstrated that the application of qPCR and SNP assays is effective for studying predation on larval suckers. We suggest that techniques associated with dissection or detection of sucker DNA from fathead minnow stomachs need improvement.

75 FR 70289 - Notice of Appointment of Individuals to Serve as Members of Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-17

... INFORMATION CONTACT: Cynthia Roscoe, Director of Human Resources, U.S. International Trade Commission (202... the PRB: Vice Chairman Irving A. Williamson Vice-Chair of the PRB: Commissioner Daniel R. Pearson...

5. Historic American Buildings Survey, Arthur W. Stewart, Photographer September ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. Historic American Buildings Survey, Arthur W. Stewart, Photographer September 10, 1936 WEST ELEVATION OF FIREPLACE IN CENTER ROOM. - Washington Anderson House, Texas Route 79 at Northeast edge of Round Rock, Round Rock, Williamson County, TX

36. Basement, cellar beneath main stairway, with skylight in stair ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

36. Basement, cellar beneath main stairway, with skylight in stair riser, and adjacent storage room, view to east - Portsmouth Naval Hospital, Hospital Building, Rixey Place, bounded by Williamson Drive, Holcomb Road, & The Circle, Portsmouth, Portsmouth, VA

VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, FLOOR SYSTEM AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF SOUTH SAN GABRIEL RIVER BRIDGE, FLOOR SYSTEM AND LATERAL BRACING, LOOKING NORTH. - South San Gabriel River Bridge, Spanning South Fork of San Gabriel River at Georgetown at Business Route 35, Georgetown, Williamson County, TX

78 FR 39727 - FFP Missouri 2, LLC; Notice of Proposed Restricted Service List for a Programmatic Agreement

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-02

... service list for Project No. 13701 as follows: John Eddins, Advisory Council on LaDonna Brown, Chickasaw.... Pennsylvania Avenue, NW., Washington, DC 20004. Greg Williamson, Mississippi Department Kenneth H. Carlton...

Multi-stimuli-responsive organometallic gels based on ferrocene-linked poly(aryl ether) dendrons: reversible redox switching and Pb2+-ion sensing.

PubMed

Lakshmi, Neelakandan Vidhya; Mandal, Dipendu; Ghosh, Sundargopal; Prasad, Edamana

2014-07-14

We describe the design, synthesis, and "stimuli-responsive" study of ferrocene-linked Fréchet-type [poly(aryl ether)]-dendron-based organometallic gels, in which the ferrocene moiety is attached to the dendron framework through an acyl hydrazone linkage. The low-molecular-weight gelators (LMWGs) form robust gels in both polar and non-polar solvent/solvent mixtures. The organometallic gels undergo stimuli-responsive behavior through 1) thermal, 2) chemical, and 3) electrochemical methods. Among them, conditions 1 and 3 lead to seamlessly reversible with repeated cycles of identical efficiency. Results indicate that the flexible nature of the poly(aryl ether) dendron framework plays a key role in retaining the reversible electrochemical behavior of ferrocene moiety in the LMWGs. Further, the organometallic gelators have exhibited unique selectivity towards Pb(2+) ions (detection limit ≈10(-8)  M). The metal ion-sensing results in a gel-sol phase transition associated with a color change visible to the naked eye. Most importantly, decomplexing the metal ion from the system leads to the regeneration of the initial gel morphology, indicating the restoring ability of the organometallic gel. The metal-ligand binding nature has been analyzed by using (1)H NMR spectroscopy, mass spectrometry, and DFT calculations. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Single step synthesis and organization of gold colloids assisted by copolymer templates

NASA Astrophysics Data System (ADS)

Sarrazin, Aurélien; Gontier, Arthur; Plaud, Alexandre; Béal, Jérémie; Yockell-Lelièvre, Hélène; Bijeon, Jean-Louis; Plain, Jérôme; Adam, Pierre-Michel; Maurer, Thomas

2014-06-01

We report here an original single-step process for the synthesis and self-organization of gold colloids by simply incorporating gold salts into a solution prepared using polystyrene (PS)-polymethylmethacrylate copolymer and thiolated PS with propylene glycol methyl ether acetate as a solvent. The spin-coating and annealing of this solution then allows the formation of PS domains. Depending on the polymer concentration of the as-prepared solution, there can be either one or several gold nanoparticles (Au NPs) per PS domain. For high concentrations of Au NPs in PS domains, the coupling between plasmonic NPs leads to the observation of a second peak in the optical extinction spectrum. Such a collective effect could be relevant for the development of optical strain sensors in the near future.

Synthesis and biological screening by novel hybrid fluorocarbon hydrocarbon compounds for use as artificial blood substitutes

NASA Technical Reports Server (NTRS)

Moacanin, J.; Scherer, K.; Toronto, A.; Lawson, D.; Terranova, T.; Yavrouian, A.; Astle, L.; Harvey, S.; Kaaelble, D. H.

1979-01-01

A series of hybrid fluorochemicals of general structure R(1)R(2)R(3)CR(4) was prepared where the R(i)'s (i=1,2,3) is a saturated fluoroalkyl group of formula C sub N F sub 2n+1, and R(4) is an alkyl group C sub n H sub 2n+1 or a related moiety containing amino, ether, or ester functions but no CF bonds. Compounds of this class containing approximately eight to twenty carbons total have physical properties suitable for use as the oxygen carrying phase of fluorochemical emulsion artificial blood. The chemical synthesis, and physical and biological testing of pure single isomers of the proposed artificial blood candidate compounds are included. Significant results are given.

The Cephalostatins 21. Synthesis of Bis-steroidal Pyrazine Rhamnosides1

PubMed Central

Pettit, George R.; Mendonça, Ricardo F.; Knight, John C.; Pettit, Robin K.

2011-01-01

The synthesis of bis-steroidal pyrazines derived from 3-oxo-11,21-dihydroxy-pregna- 4,17(20)-diene (4) and glycosylation of a D-ring side chain with α-L-rhamnose has been summarized. Rearrangment of steroidal pyrazine 10 to 14 was found to occur with boron triflouride etherate. Glycosylation of pyrazine 10 using 2,3,4-tri-O-acetyl-α-L-rhamnose iodide led to 1,2-orthoester-α-L-rhamnose pyrazine 17b. By use of a persilylated α-L-rhamnose iodide as donor, formation of the orthoester was avoided. Bis-steroidal pyrazine 10 and rhamnosides 17b and 21c were found to significantly inhibit cancer cell growth in a murine and human cancer cell line panel. Pyrazine 9 inhibited growth of the nosocomial pathogen Enterococcus faecalis. PMID:21899266

Synthesis and Mesomorphic Behavior of Poly((2S, 3S)-(+)-2-Chloro-3- Methylpentyl 4’-(Omega-Vinyloxyalkyloxy)biphenyl-4-Carboxylate)s with Ethyl and Propyl Alkyl Groups

DTIC Science & Technology

1994-06-30

1 . Synthesis of (2S, 3S)-(+)-2-chloro-3-methyl-pentyl 4’-(2-vinyloxyethyloxy) biphenyl-4-carboxylate (15-2...CH2)2-),7.65 (d, 3=8.3Hz, 2 ArH, m to -COO-), 8.11 (d, J=7.4Hz, 2 ArH, o to -COO-). 3-Chloroprop~yl- 1 -vinyl ether (13-3) The mixture of 3- chloropropan ...VA .% fo - " A’* *i f’. - % .oL.,ae- a * 1 nOl-6..io. Ocw. ’•.1ý’ ..a.. :l•t :...•.t ;,,31 -. 1 " 1 . 2 . 10 1 -- Of , • l 0’ i’*J.. e t *no suaqetg

Patterns of Larval Sucker Emigration from the Sprague and Lower Williamson Rivers of the Upper Klamath Basin, Oregon, Prior to the Removal of Chiloquin Dam - 2006 Annual Report

USGS Publications Warehouse

Ellsworth, Craig M.; Tyler, Torrey J.; VanderKooi, Scott P.; Markle, Douglas F.

2009-01-01

In 2006, we collected larval Lost River sucker Deltistes luxatus (LRS), shortnose sucker Chasmistes brevirostris (SNS), and Klamath largescale sucker Catostomus snyderi (KLS) emigrating from spawning areas in the Williamson and Sprague Rivers. This work is part of a multi-year effort to characterize the relative abundance, drift timing, and length frequencies of larval suckers in this watershed prior to the removal of Chiloquin Dam on the lower Sprague River. Additional larval drift samples were collected from the Fremont Bridge on Lakeshore Drive on the south end of Upper Klamath Lake near its outlet to the Link River. Because of difficulties in distinguishing KLS larvae from SNS larvae, individuals identified as either of these two species were grouped together and reported as KLS-SNS in this report. We found that larval densities varied by site with the highest densities being collected at the most upstream site on the Sprague River at river kilometer (rkm) 108.0 near Beatty, Oregon (Beatty), and the most downstream sites near Chiloquin, Oregon; one site on the Sprague River at rkm 0.7 (Chiloquin) and the other site on the Williamson River at rkm 7.4 (Williamson). Larval catches were relatively small and sporadic at two other sites on the Sprague River located between Chiloquin and Beatty (Power Station at rkm 9.5 and Lone Pine at rkm 52.7) and one site on the Sycan River at rkm 4.7. Most larvae (79 percent) collected in 2006 were identified as LRS. More larvae and eggs were collected at Chiloquin than at any other site. The seasonal timing of larval drift varied by location; larvae generally were captured earlier at upstream sites than at downstream sites. Cumulative catch percentages of drifting larvae suggest that larval LRS emigrated earlier than KLS-SNS larvae at every site. Drift of LRS larvae at Beatty began 3 to 4 weeks earlier than at Chiloquin or Williamson. At Chiloquin, peak larval catches occurred 3 and 5 weeks after peak egg catches. The daily peak in larval drift at Chiloquin occurred approximately 1.5 to 2.0 hours after sunset. Nightly peak larval drift varied by location; larvae were captured earlier in the evening at sites closer to known spawning locations than sites farther away from these areas. The highest numerical catches of sucker-sized eggs were at Chiloquin indicating that this site is in close proximity to a spawning area. Numerical catches of older, more developed larval and juvenile suckers also were highest at Chiloquin. This may be due to the turbulent nature of this site, which could have swept larger fish into the drift. Proportional catches of older, more developed larval and juvenile suckers were highest at Sycan, Lone Pine, Power Station, and Fremont Bridge. This indicates these sites are located nearer to sucker nursery areas rather than spawning areas. Very few larval LRS were collected at Fremont Bridge at the south end of Upper Klamath Lake. Larval KLS-SNS densities at Fremont Bridge were the third highest of the seven sampling sites. Peak drift of larval KLS-SNS at Fremont Bridge occurred the week after peak drift of larval KLS-SNS at Williamson. Although inter-annual variation continues to appear in the larval drift data, our results continue to show consistent patterns of larval emigration in the drainage basin. In combination with data collected from the spawning movements and destinations of radio-tagged and PIT-tagged adult suckers, this larval drift data will provide a baseline standard by which to determine the effects of dam removal on the spawning distribution of endangered Klamath Basin suckers in the Sprague River.

New Control Over Silicone Synthesis using SiH Chemistry: The Piers-Rubinsztajn Reaction.

PubMed

Brook, Michael A

2018-06-18

There is a strong imperative to synthesize polymers with highly controlled structures and narrow property ranges. Silicone polymers do not lend themselves to this paradigm because acids or bases lead to siloxane equilibration and loss of structure. By contrast, elegant levels of control are possible when using the Piers-Rubinsztajn reaction and analogues, in which the hydrophobic, strong Lewis acid B(C 6 F 5 ) 3 activates SiH groups, permitting the synthesis of precise siloxanes under mild conditions in high yield; siloxane decomposition processes are slow under these conditions. A broad range of oxygen nucleophiles including alkoxysilanes, silanols, phenols, and aryl alkyl ethers participate in the reaction to create elastomers, foams and green composites, for example, derived from lignin. In addition, the process permits the synthesis of monofunctional dendrons that can be assembled into larger entities including highly branched silicones and dendrimers either using the Piers-Rubinsztajn process alone, or in combination with hydrosilylation or other orthogonal reactions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A brominated flame retardant 2,2',4,4' tetrabrominated diphenyl ether (BDE-47) leads to lipogenesis in the copepod Tigriopus japonicus.

PubMed

Lee, Min-Chul; Han, Jeonghoon; Lee, Seung-Hwi; Kim, Duck-Hyun; Kang, Hye-Min; Won, Eun-Ji; Hwang, Dae-Sik; Park, Jun Chul; Om, Ae-Son; Lee, Jae-Seong

2016-09-01

De novo lipogenesis (DNL) is a fatty acid synthesis process that requires several genes, including sterol regulatory element binding protein (SREBP), ATP-citrate lyase (ACLY), and acetyl-CoA carboxylase (ACC). DNL up-regulation is able to induce fat accumulation through an increase in fatty acids. To investigate the relationship between DNL up-regulation and the accumulation of fatty acids and lipid droplets in response to 2,2',4,4' tetrabrominated diphenyl ether (BDE-47), we examined DNL in the copepod Tigriopus japonicus. Transcription levels of DNL-related genes were increased after exposure to 2.5μg/L BDE-47 for 24h. After exposure to 2.5μg/L BDE-47, palmitic acid was significantly increased (P<0.05) at days 1 and 4, along with upregulation of fatty acid synthesis-related genes (e.g., desaturases and elongases). However, docosahexaenoic acid and arachidonic acid were down-regulated at days 1 and 4, showing an antagonistic effect. Lipid droplet area significantly increased in Nile red staining analysis after 24h of exposure to 2.5μg/L BDE-47 in T. japonicus, while DNL was down-regulated in response to 500μM salicylate (a lipogenesis inhibitor), indicating that BDE-47 exposure is closely associated with an increase in fatty acids in this copepod. This study provides a better understanding of the effects of BDE-47 on DNL in copepods. Copyright © 2016 Elsevier B.V. All rights reserved.

75 FR 14207 - Virginia Electric and Power Company d/b/a/Dominion Virginia Power, and Old Dominion Electric...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

..., VA. For Further Information, Contact: Alicia Williamson, Project Manager, Environmental Projects...-mail to Alicia[email protected] . Dated at Rockville, Maryland, this 17th day of March 2010. For the...

3. DETAIL VIEW OF THE MAIN ENTRY OF BUILDING 13, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. DETAIL VIEW OF THE MAIN ENTRY OF BUILDING 13, SHOWING THE ORIGINAL LIGHT FIXTURES AND THE EGYPTIAN MOTIF DECORATION; LOOKING SSW. (Ryan) - Veterans Administration Medical Center, Building No. 13, Old State Route 13 West, Marion, Williamson County, IL

An Apple for the Volunteers.

ERIC Educational Resources Information Center

Butler, Judy; Grier, Terry B.

2000-01-01

A few years ago, the Williamson County (Tennessee) School District developed a strategic plan to encourage volunteers' participation. The plan includes a vision, goals, and objectives; strategies for increasing community involvement; recognition for all volunteers (via the Shining Apple Award); and program evaluation. (MLH)

40 CFR Table 6 to Subpart Jj of... - VHAP of Potential Concern

Code of Federal Regulations, 2011 CFR

2011-07-01

... glycol butyl ether, ethylene glycol ethyl ether (2-ethoxy ethanol), ethylene glycol hexyl ether, ethylene..., ethylene glycol mono-2-ethylhexyl ether, diethylene glycol butyl ether, diethylene glycol ethyl ether... glycol propyl ether, triethylene glycol butyl ether, triethylene glycol ethyl ether, triethylene glycol...

Stress and Life Satisfaction of Turkish College Students

ERIC Educational Resources Information Center

Kaya, Cahit; Tansey, Timothy N.; Melekoglu, Macid; Çakiroglu, Orhan

2015-01-01

This study investigated the association between perceived stress and life satisfaction of Turkish college students. The "Satisfaction with Life Scale" (Diener, Emmons, Larsen, & Griffin, 1985), the "Perceived Stress Scale" (Cohen & Williamson, 1988), and a brief demographic questionnaire were administered to 235 college…

3. DETAIL VIEW OF S ENTRY DOOR TO BUILDING 8, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. DETAIL VIEW OF S ENTRY DOOR TO BUILDING 8, SHOWING ONE OF THE ORIGINAL LIGHT FIXTURES AND THE EGYPTIAN MOTIF DECORATION; LOOKING N (Ryan) - Veterans Administration Medical Center, Building No. 8, Old State Route 13 West, Marion, Williamson County, IL

Sulfonimide-containing poly(arylene ether)s and poly(arylene ether sulfone)s, methods for producing the same, and uses thereof

DOEpatents

Hofmann, Michael A.

2006-11-14

The present invention is directed to sulfonimide-containing polymers, specifically sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, and processes for making the sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, for use conductive membranes and fuel cells.

Strain and grain size of TiO2 nanoparticles from TEM, Raman spectroscopy and XRD: The revisiting of the Williamson-Hall plot method

NASA Astrophysics Data System (ADS)

Kibasomba, Pierre M.; Dhlamini, Simon; Maaza, Malik; Liu, Chuan-Pu; Rashad, Mohamed M.; Rayan, Diaa A.; Mwakikunga, Bonex W.

2018-06-01

The Williamson-Hall (W-H) equation, which has been used to obtain relative crystallite sizes and strains between samples since 1962, is revisited. A modified W-H equation is derived which takes into account the Scherrer equation, first published in 1918, (which traditionally gives more absolute crystallite size prediction) and strain prediction from Raman spectra. It is found that W-H crystallite sizes are on average 2.11 ± 0.01 times smaller than the sizes from Scherrer equation. Furthermore the strain from the W-H plots when compared to strain obtained from Raman spectral red-shifts yield factors whose values depend on the phases in the materials - whether anatase, rutile or brookite. Two main phases are identified in the annealing temperatures (350 °C-700 °C) chosen herein - anatase and brookite. A transition temperature of 550 °C has been found for nano-TiO2 to irreversibly transform from brookite to anatase by plotting the Raman peak shifts against the annealing temperatures. The W-H underestimation on the strain in the brookite phase gives W-H/Raman factor of 3.10 ± 0.05 whereas for the anatase phase, one gets 2.46 ± 0.03. The new βtot2cos2θ-sinθ plot and when fitted with a polynomial yield less strain but much better matching with experimental TEM crystallite sizes and the agglomerates than both the traditional Williamson-Hall and the Scherrer methods. There is greater improvement in the model when linearized - that is the βtotcos2θ-sinθ plot rather than the βtot2cos2θ-sinθ plot.

New Polyacetylenes, DGAT inhibitors from the roots of Panax ginseng.

PubMed

Lee, Seung Woong; Kim, Koanhoi; Rho, Mun-Chual; Chung, Mi Yeon; Kim, Young Ho; Lee, Sangku; Lee, Hyun Sun; Kim, Young Kook

2004-03-01

The petroleum ether extract of Panax ginseng showed a significant inhibition of the diacylglycerol acyltransferase (DGAT) enzyme from rat liver microsomes. Bioactivity-guided fractionation led to the isolation of two new polyacetylenic compounds, (9 R,10 S)-epoxyheptadecan-4,6-diyn-3-one ( 1) and 1-methoxy-(9 R,10 S)-epoxyheptadecan-4,6-diyn-3-one ( 2). Their chemical structures were elucidated on the basis of spectroscopic evidence and asymmetric synthesis. IC50 values of 9 microg/mL ( 1) and 32 microg/mL ( 2) were obtained.

Targeting the UPR to Circumvent Endocrine Resistance in Breast Cancer

DTIC Science & Technology

2016-12-01

chemistry Our initial synthetic efforts in the NPPTA project are to generate gram quantities of NPPTA and JS-20 as seen in Figure 1. NPPTA JS...diversity on the bi-aryl ether moiety of the target analogs. This plan requires the preparation of gram quantities of acid 2. 1 X = H, CF 3 N N NNH S O...NNH S O NH O O NH2 Scheme 3. Proposed synthesis of NPPTA Our goal in this project is to prepare five grams of NPPTA and JS20 as seen in Figure 1

Composite Materials with Improved Properties in Compression: Synthesis of 3-Methylene-1,1-Dichlorosilacyclobutane and 1,1-Dichlorosilacyclopent-3-ene

DTIC Science & Technology

1990-05-09

reagents may in fact be involved. Of synthetic interest, V undergoes intramolecular Grignard ring closure to yield III (10%). While the yield of III is low...VII) as the major product along with 1,4-bis(trichlorosilyl)- cis-2-butene (VIII). VII undergoes cyclization by an intramolec- ular Grignard ring...addition of methyl Grignard to III. The 1H 8 am NMR chemical shifts of I in diethyl ether are consistently about 0.4 ppm downfield from those previously

Merging domino and redox chemistry: stereoselective access to di- and trisubstituted β,γ-unsaturated acids and esters.

PubMed

Tejedor, David; Méndez-Abt, Gabriela; Cotos, Leandro; García-Tellado, Fernando

2012-03-19

Merging is the game! The coupling of a domino reaction and an internal neutral redox reaction constitutes an excellent manifold for the stereoselective synthesis of di- and trisubstituted olefins featuring a malonate unit, an ester, or a free carboxylic acid as substituents at the allylic position (see scheme; MW=microwave). The reaction utilizes simple starting materials (propargyl vinyl ethers), methanol or water as solvents, and a very simple and bench-friendly protocol. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Asymmetric organocatalyzed Michael addition of nitromethane to a 2-oxoindoline-3-ylidene acetaldehyde and the three one-pot sequential synthesis of (-)-horsfiline and (-)-coerulescine.

PubMed

Mukaiyama, Takasuke; Ogata, Kento; Sato, Itaru; Hayashi, Yujiro

2014-10-13

(-)-Horsfiline and (-)-coerulescine were synthesized through three one-pot operations in 33 and 46% overall yield, respectively. Key to the success was the efficient use of a diarylprolinol silyl ether to catalyze the asymmetric Michael addition of nitromethane to a 2-oxoindoline-3-ylidene acetaldehyde. This allowed the all-carbon quaternary, spirocyclic carbon stereocenter to be constructed in good yield with excellent enantioselectivity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent Advances in Synthetic Bioelastomers

PubMed Central

Shi, Rui; Chen, Dafu; Liu, Quanyong; Wu, Yan; Xu, Xiaochuan; Zhang, Liqun; Tian, Wei

2009-01-01

This article reviews the degradability of chemically synthesized bioelastomers, mainly designed for soft tissue repair. These bioelastomers involve biodegradable polyurethanes, polyphosphazenes, linear and crosslinked poly(ether/ester)s, poly(ε-caprolactone) copolymers, poly(1,3-trimethylene carbonate) and their copolymers, poly(polyol sebacate)s, poly(diol-citrates) and poly(ester amide)s. The in vitro and in vivo degradation mechanisms and impact factors influencing degradation behaviors are discussed. In addition, the molecular designs, synthesis methods, structure properties, mechanical properties, biocompatibility and potential applications of these bioelastomers were also presented. PMID:20057942

Construction of substituted benzene rings by palladium-catalyzed direct cross-coupling of olefins: a rapid synthetic route to 1,4-naphthoquinone and its derivatives.

PubMed

Hu, Peng; Huang, Shijun; Xu, Jing; Shi, Zhang-Jie; Su, Weiping

2011-10-10

Ring the changes: the direct cross-coupling of electron-deficient 1,4-benzoquinone or its derivatives with electron-rich alkyl vinyl ethers proceeds in a tandem manner to produce substituted benzene rings with good selectivity and in good to excellent yields. The reaction has the potential for the rapid synthesis of diverse substituted benzene rings as it is not limited by substituent effects. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Synthesis of Phenyl Acetylene Phenols for Development of New Explosives

NASA Astrophysics Data System (ADS)

Chikhradze, Nikoloz; Nadirashvili, Merab; Khomeriki, Sergo; Varshanidze, Iasha

2017-12-01

The purpose of this research is to produce derivatives of simple phenols as “raw material” for the synthesis of new phenolic explosives. A big number of valuable products is synthesized from phenol and its homologues including well-known explosives - picric acid, methyl picrate, cresolite, etc. In general, a structural modification of well-known explosives’ molecules is the most important among the methods for the synthesis of new explosives. This method can be used in certain modifications. For example, the synthesis of methyl picrate is possible not only to replace picric acid’s hydroxyl with metoxyl, but with nitration of anisole as well, i. e, by the reciprocating synthesis. Thus, to produce the new analogues of well-known phenolic explosives, the preliminary modification of simple phenols’ molecules and further nitration, presumably by a formation of dinitro derivatives may be performed. The alkylation of phenol, anisole and m - cresol by the secondary phenyl acetylene alcohols in the presence of concentrated phosphoric acid was carried out. Para-substituted alkynyl phenols with high yields were developed. The chemical transformations were carried out by a participation of their molecules’ active centres. The corresponding ethers, esters and saturated isologues have been synthesized. The article describes the conditions of a synthesis of 14 new phenyl acetylenes’ substances that may be used as substrates in a nitration reaction.

Perceived Best Practices for Faculty Training in Distance Education

ERIC Educational Resources Information Center

McVey, Michael G.

2014-01-01

Student learning style differences have been widely researched in both traditional face-to-face and online learning environments (Irani, Scherler & Harrington, 2003;Steinbronn, 2007; Williamson & Watson, 2007; Ugur, Akkoyunlu & Kurbanoglu, 2001). After conducting a literature review of adult student learning styles and teaching method…

FAA Aviation Forecasts, Fiscal Years 1994-2005

DTIC Science & Technology

1994-03-01

ID (BOI) Fort Lauderdale Executive, FL (FXE) Idaho Falls Fanning Field, ID (IDA) Fort Myers Page Field, FL (FMY) Lewiston , ID (LWS) Fort Myers...Pacoima/Whitman, California (WHP) 3. Lakeland, Florida (LAL) 4. Valdosta Municipal, Georgia (VLD) 5. Halley, Idaho (SUN) 6. Marion Williamson County

3. N ELEVATION OF BUILDING 1'S E WING, SHOWING THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. N ELEVATION OF BUILDING 1'S E WING, SHOWING THE PILASTERS, TERRA COTTA PANELS, AND THE EGYPTIAN MOTIF DECORATIVE CORNICE ELEMENTS; LOOKING S. (Ryan) - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

14. OVERALL VIEW OF ELEVATOR LOBBY OF BUILDING 1, SHOWING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. OVERALL VIEW OF ELEVATOR LOBBY OF BUILDING 1, SHOWING THE CONTINUATION OF THE EGYPTIAN MOTIF DECORATIVE DETAIL; LOOKING NNW TOWARD THE MAIN LOBBY. (Ryan & Harms) - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

Getting Started Using American Memory.

ERIC Educational Resources Information Center

Singleton, Laurel R., Ed.

2001-01-01

This publication features teaching ideas generated by classroom teachers. For grades K-4, fourth grade teacher, Janet Williamson, has developed "Off and Running with Primary Sources" which describes how she introduces students to primary sources using historical advertisements. Appropriate for grades 5-8, a strategy was developed by…

Infant-Like Social Interactions Between a Robot and a Human Caregiver

DTIC Science & Technology

2006-01-01

developmental psychology and ethology, as well as the applications of these fields to robotics as outlined by Brooks, Ferrell, Irie, Marjanovic ...Irie, R., Kemp, C. C., Marjanovic , M., Scassellati, B., & Williamson M. (1998). Alternative essences of intelligence. Proceedings of the Fifteenth

XRD analysis of undoped and Fe doped TiO{sub 2} nanoparticles by Williamson Hall method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bharti, Bandna; Barman, P. B.; Kumar, Rajesh, E-mail: rajesh.kumar@juit.ac.in

2015-08-28

Undoped and Fe doped titanium dioxide (TiO{sub 2}) nanoparticles were synthesized by sol-gel method at room temperature. The synthesized samples were annealed at 500°C. For structural analysis, the prepared samples were characterized by X-ray diffraction (XRD). The crystallite size of TiO{sub 2} and Fe doped TiO{sub 2} nanoparticles were calculated by Scherer’s formula, and was found to be 15 nm and 11 nm, respectively. Reduction in crystallite size of TiO{sub 2} with Fe doping was observed. The anatase phase of Fe-doped TiO{sub 2} nanoparticles was also confirmed by X-ray diffraction. By using Williamson-Hall method, lattice strain and crystallite size weremore » also calculated. Williamson–Hall plot indicates the presence of compressive strain for TiO{sub 2} and tensile strain for Fe-TiO{sub 2} nanoparticles annealed at 500°C.« less

Estimation of lattice strain in nanocrystalline RuO2 by Williamson-Hall and size-strain plot methods

NASA Astrophysics Data System (ADS)

Sivakami, R.; Dhanuskodi, S.; Karvembu, R.

2016-01-01

RuO2 nanoparticles (RuO2 NPs) have been successfully synthesized by the hydrothermal method. Structure and the particle size have been determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM). UV-Vis spectra reveal that the optical band gap of RuO2 nanoparticles is red shifted from 3.95 to 3.55 eV. BET measurements show a high specific surface area (SSA) of 118-133 m2/g and pore diameter (10-25 nm) has been estimated by Barret-Joyner-Halenda (BJH) method. The crystallite size and lattice strain in the samples have been investigated by Williamson-Hall (W-H) analysis assuming uniform deformation, deformation stress and deformation energy density, and the size-strain plot method. All other relevant physical parameters including stress, strain and energy density have been calculated. The average crystallite size and the lattice strain evaluated from XRD measurements are in good agreement with the results of TEM.

Performance of a cavity-method-based algorithm for the prize-collecting Steiner tree problem on graphs

NASA Astrophysics Data System (ADS)

Biazzo, Indaco; Braunstein, Alfredo; Zecchina, Riccardo

2012-08-01

We study the behavior of an algorithm derived from the cavity method for the prize-collecting steiner tree (PCST) problem on graphs. The algorithm is based on the zero temperature limit of the cavity equations and as such is formally simple (a fixed point equation resolved by iteration) and distributed (parallelizable). We provide a detailed comparison with state-of-the-art algorithms on a wide range of existing benchmarks, networks, and random graphs. Specifically, we consider an enhanced derivative of the Goemans-Williamson heuristics and the dhea solver, a branch and cut integer linear programming based approach. The comparison shows that the cavity algorithm outperforms the two algorithms in most large instances both in running time and quality of the solution. Finally we prove a few optimality properties of the solutions provided by our algorithm, including optimality under the two postprocessing procedures defined in the Goemans-Williamson derivative and global optimality in some limit cases.

Improved synthesis of aryltrialkoxysilanes via treatment of aryl Grignard or lithium reagents with tetraalkyl orthosilicates.

PubMed

Manoso, Amy S; Ahn, Chuljin; Soheili, Arash; Handy, Christopher J; Correia, Reuben; Seganish, W Michael; Deshong, Philip

2004-11-26

General reaction conditions for the synthesis of aryl(trialkoxy)silanes from aryl Grignard and lithium reagents and tetraalkyl orthosilicates (Si(OR)(4)) have been developed. Ortho-, meta-, and para-substituted bromoarenes underwent efficient metalation and silylation at low temperature to provide aryl siloxanes. Mixed results were obtained with heteroaromatic substrates: 3-bromothiophene, 3-bromo-4-methoxypyridine, 5-bromoindole, and N-methyl-5-bromoindole underwent silylation in good yield, whereas a low yield of siloxane was obtained from 2-bromofuran, and 2-bromopyridine failed to give silylated product. The synthesis of siloxanes via organolithium and magnesium reagents was limited by the formation of di- and triarylated silanes (Ar(2)Si(OR)(2) and Ar(3)SiOR, respectively) and dehalogenated (Ar-H) byproducts. Silylation at low temperature gave predominantly monoaryl siloxanes, without requiring a large excess of the electrophile. Optimal reaction conditions for the synthesis of siloxanes from aryl Grignard reagents entailed addition of arylmagnesium reagents to 3 equiv of tetraethyl- or tetramethyl orthosilicate at -30 degrees C in THF. Aryllithium species were silylated using 1.5 equiv of tetraethyl- or tetramethyl orthosilicate at -78 degrees C in ether.

Comparison of classic and microwave-assisted synthesis of benzo-thio crown ethers, and investigation of their ion pair extractions

NASA Astrophysics Data System (ADS)

Calisir, Umit; Çiçek, Baki

2017-11-01

Macrocyclic benzo-thio crown ethers and benzo-oxo crown ethers were prepared using an esterification-ring closing method. These compounds were synthesised using 2,2‧-dithiodibenzoyl chloride, and various glycols and dithiols, in the presence of pyridine base under a nitrogen atmosphere in chloroform. All reactions were performed under reflux condition with conventional heating and microwave (MW) irradiation. The synthesised macrocycles were characterised by FT-IR, 1H NMR, 13C NMR, LC-MS, and elemental analysis methods. Extraction studies have been performed on these original macrocycles using liquid-liquid ion-pair extraction with Li+, Na+, K+, Ni2+, Ca2+, Mg2+, Zn2+, Fe2+,Fe3+, Co3+, Pb2+, Cr3+, Ag+, and Cd2+.The KD, ext.%, ΔG and log KExt values were also calculated. While (U1-U7) ligands exhibits selectivity for Zn2+, Ag+, Ca2+, Pb2+, Fe3+, Cr3+, Co2+, Mg2+, Cd2+, and Ni2+ metal salts, they showed no selectivity for Li+, K+ and Na+ metal salts. Furthermore, Fe3+is the most selective cation for all ligands for competitive extraction. We also observed that microwave heating can have certain benefits over conventional ovens: reaction rate acceleration, milder reaction conditions, higher chemical yield, and lower energy usage. These ligands could be used as metal sensors, enzyme inhibitors, antimicrobial/antifungal agents, and in biological applications.

Libro + Biblioteca = Libertad

ERIC Educational Resources Information Center

Rodriguez, Rodrigo Joseph

2016-01-01

On the margins of El Paso, Texas, a teacher-librarian communicates daily to her students the following bilingual mantra: "'Esta biblioteca les pertenece a ustedes.' This is your very own library." Lisa M. López-Williamson is the teacher-librarian and literacy activist and advocate at William "Guillermo" C. Herrera Elementary…

4. DETAIL VIEW OF NW CORNER OF BUILDING 1'S W ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. DETAIL VIEW OF NW CORNER OF BUILDING 1'S W WING, SHOWING THE PILASTERS, TERRA COTTA PANELS, AND THE EGYPTIAN MOTIF DECORATIVE CORNICE ELEMENTS; LOOKING ENE. (Harms) - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

An Overview of the History of Library Science Teaching Materials.

ERIC Educational Resources Information Center

Metzger, Philip A.

1986-01-01

This introduction to, and overview of, history of library science instructional materials covers the Williamson Report, teaching materials from early Columbia days onward, American Library Association book publishing activity, media in curricula and library school publication of syllabi, commercial publishing of textbooks, and periodicals in…

Successful Strategies: Building a School-to-Careers System.

ERIC Educational Resources Information Center

Thiers, Naomi, Ed.

The following papers are included: "Building a Broad-Based Partnership" (Randy Wallace); "Creating a Partnership Agreement" (M. Amos Clifford, Robyn Flores); "Forming True Partnerships with Employers" (Lee W. Sloan); "Choosing a Model for Your School-to-Careers System" (Patty Williamson); "Case Study: Career Academy Model" (Shirley Earlise…

Diorcinol D Exerts Fungicidal Action against Candida albicans through Cytoplasm Membrane Destruction and ROS Accumulation

PubMed Central

Li, Ying; Chang, Wenqiang; Zhang, Ming; Li, Xiaobin; Jiao, Yang; Lou, Hongxiang

2015-01-01

Candida albicans, which is the most common human fungal pathogen, causes high mortality among immunocompromised patients. Antifungal drug resistance becomes a major challenge for the management of Candida infection. Diorcinol D (DD), a diphenyl ether derivative isolated from an endolichenic fungus, exerted fungicidal action against Candida species. In this study, we investigated the possible mechanism of its antifungal activity. The change of membrane dynamics and permeability suggested that the cell membrane was disrupted by the treatment of DD. This was further supported by the evidences of intracellular glycerol accumulation, alteration of cell ultrastructure, and down-regulation of genes involved in cell membrane synthesis. In addition, the treatment of C. albicans with DD resulted in the elevation of reactive oxygen species (ROS), which caused the dysfunction of mitochondria. These altogether suggested that DD exerted its antifungal activity through cytoplasmic membrane destruction and ROS accumulation. This finding is helpful to uncover the underlying mechanisms for the diphenyl ether derivatives and provides a potential application in fighting clinical fungal infections. PMID:26047493

First Attempt of Glycidol-to-Monoalkyl Glyceryl Ethers Conversion by Acid Heterogeneous Catalysis: Synthesis and Simplified Sustainability Assessment.

PubMed

Ricciardi, Maria; Passarini, Fabrizio; Capacchione, Carmine; Proto, Antonio; Barrault, Joel; Cucciniello, Raffaele; Cespi, Daniele

2018-04-14

The selective preparation of monoalkylglyceryl ethers (MAGEs) is a task for researchers owing to their broad range of applications. In this work, green feedstocks such as glycidol and alcohols were used to prepare MAGEs under mild reaction conditions (80 °C, 3 h, 0.5 mol % catalyst) in the presence of acid heterogeneous catalysts. Nafion shows the best performances in terms of conversion and selectivity to MAGES and also high stability. A comparison of the environmental performances with the most consolidated pathway from glycerol has shown that the usage of glycidol (recovered as a value-added product from Epicerol process) and Nafion leads to a lower impact on ecosystems. In addition, results achieved from a simplified socio-economic analysis show that the innovative route here proposed has potential (at the laboratory scale) of enhancing potential gains and of reducing the social implications resulting from externalities associated with environmental impacts (e.g., CO 2 equivalents). © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cytotoxic Activity and Structure-Activity Relationship of Triazole-Containing Bis(Aryl Ether) Macrocycles.

PubMed

Hernández-Vázquez, Eduardo; Chávez-Riveros, Alejandra; Romo-Pérez, Adriana; Ramírez-Apán, María Teresa; Chávez-Blanco, Alma D; Morales-Bárcenas, Rocío; Dueñas-González, Alfonso; Miranda, Luis D

2018-05-17

Cancer continues to be a worldwide health problem. Certain macrocyclic molecules have become attractive therapeutic alternatives for this disease because of their efficacy and, frequently, their novel mechanisms of action. Herein, we report the synthesis of a series of 20-, 21-, and 22-membered macrocycles containing triazole and bis(aryl ether) moieties. The compounds were prepared by a multicomponent approach from readily available commercial substrates. Notably, some of the compounds displayed interesting cytotoxicity against cancer (PC-3) and breast (MCF-7) cell lines, especially those bearing an aliphatic or a trifluoromethyl substituent on the N-phenyl moiety (IC 50 <13 μm). Additionally, some of the compounds were able to induce apoptosis relative to the solvent control; in particular, (Z)-N-cyclohexyl-7-oxo-6-[4-(trifluoromethyl)phenyl]-1 1 H-3,10-dioxa-6-aza-1(4,1)-triazola-4(1,3),9(1,4)-dibenzenacyclotridecaphane-5-carboxamide (12 f) was the most potent in this regard (22.7 % of apoptosis). © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxime Ether Lipids as Transfection Agents: Assembly and Complexation with siRNA.

PubMed

Puri, Anu; Zampino, Serena; Viard, Mathias; Shapiro, Bruce A

2017-01-01

RNAi-based therapeutic approaches to combat cancer and other diseases are currently an area of great interest. However, practical applications of this approach rely on optimal tools to carry and deliver siRNA to the desired site. Oxime ether lipids (OELs) are a class of molecules among other various carriers being examined for siRNA delivery. OELs, relatively new candidates, belong to a class of non-glycerol based lipids and have begun to claim their place as an siRNA delivery carrier in the field of RNAi therapy. Chemical synthesis steps of OELs are considered relatively simple with the ability to modify the functionalities as desired. OEL-siRNA complexes can be assembled in the presence of serum-containing buffers (or cell culture media) and recent data from our and other groups have demonstrated that OELs are viable carriers for siRNA delivery in the cell culture systems. In this chapter, we provide the details of experimental protocols routinely used in our laboratory to examine OEL-siRNA complexes including their assembly, stability, and transfection efficiencies.

Synthesis and Characterization of a Poly(ethylene glycol)-Poly(simvastatin) Diblock Copolymer

PubMed Central

Asafo-Adjei, Theodora A.; Dziubla, Thomas D.; Puleo, David A.

2014-01-01

Biodegradable polyesters are commonly used as drug delivery vehicles, but their role is typically passive, and encapsulation approaches have limited drug payload. An alternative drug delivery method is to polymerize the active agent or its precursor into a degradable polymer. The prodrug simvastatin contains a lactone ring that lends itself to ring-opening polymerization (ROP). Consequently, simvastatin polymerization was initiated with 5 kDa monomethyl ether poly(ethylene glycol) (mPEG) and catalyzed via stannous octoate. Melt condensation reactions produced a 9.5 kDa copolymer with a polydispersity index of 1.1 at 150 °C up to a 75 kDa copolymer with an index of 6.9 at 250 °C. Kinetic analysis revealed first-order propagation rates. Infrared spectroscopy of the copolymer showed carboxylic and methyl ether stretches unique to simvastatin and mPEG, respectively. Slow degradation was demonstrated in neutral and alkaline conditions. Lastly, simvastatin, simvastatin-incorporated molecules, and mPEG were identified as the degradation products released. The present results show the potential of using ROP to polymerize lactone-containing drugs such as simvastatin. PMID:25431653

The influence of organic solvents on estimates of genotoxicity and antigenotoxicity in the SOS chromotest.

PubMed

Quintero, Nathalia; Stashenko, Elena E; Fuentes, Jorge Luis

2012-04-01

In this work, the toxicity and genotoxicity of organic solvents (acetone, carbon tetrachloride, dichloromethane, dimethylsulfoxide, ethanol, ether and methanol) were studied using the SOS chromotest. The influence of these solvents on the direct genotoxicity induced by the mutagens mitomycin C (MMC) and 4-nitroquinoline-1-oxide (4-NQO) were also investigated. None of the solvents were genotoxic in Escherichia coli PQ37. However, based on the inhibition of protein synthesis assessed by constitutive alkaline phosphatase activity, some solvents (carbon tetrachloride, dimethylsulfoxide, ethanol and ether) were toxic and incompatible with the SOS chromotest. Solvents that were neither toxic nor genotoxic to E. coli (acetone, dichloromethane and methanol) significantly reduced the genotoxicity of MMC and 4-NQO. When these solvents were used to dissolve vitamin E they increased the antigenotoxic activity of this compound, possibly through additive or synergistic effects. The relevance of these results is discussed in relation to antigenotoxic studies. These data indicate the need for careful selection of an appropriate diluent for the SOS chromotest since some solvents can modulate genotoxicity and antigenotoxicity.

Discovery of Nanomolar Dengue and West Nile Virus Protease Inhibitors Containing a 4-Benzyloxyphenylglycine Residue.

PubMed

Behnam, Mira A M; Graf, Dominik; Bartenschlager, Ralf; Zlotos, Darius P; Klein, Christian D

2015-12-10

The dengue virus (DENV) and West Nile Virus (WNV) NS2B-NS3 proteases are attractive targets for the development of dual-acting therapeutics against these arboviral pathogens. We present the synthesis and extensive biological evaluation of inhibitors that contain benzyl ethers of 4-hydroxyphenylglycine as non-natural peptidic building blocks synthesized via a copper-complex intermediate. A three-step optimization strategy, beginning with fragment growth of the C-terminal 4-hydroxyphenylglycine to the benzyloxy ether, followed by C- and N-terminal optimization, and finally fragment merging generated compounds with in vitro affinities in the low nanomolar range. The most promising derivative reached Ki values of 12 nM at the DENV-2 and 39 nM at the WNV proteases. Several of the newly discovered protease inhibitors yielded a significant reduction of dengue and West Nile virus titers in cell-based assays of virus replication, with an EC50 value of 3.4 μM at DENV-2 and 15.5 μM at WNV for the most active analogue.

Synthesis of Enantiopure Alicyclic Ethers and Their Activity on the Chemosensory Organ of the Ectoparasite of Honey Bees, Varroa destructor.

PubMed

Pinnelli, Govardhana R; Singh, Nitin K; Soroker, Victoria; Plettner, Erika

2016-11-16

The preparation of enantiopure conformationally restricted alicyclic ethers and their inhibitory activities on the chemosensory organ of the Varroa destructor, a parasite of honey bees, are reported in this article. We tested the effect of enantiopure ethers of cis-5-(2'-hydroxyethyl)cyclopent-2-en-1-ol on the Varroa chemosensory organ by electrophysiology, for their ability to inhibit the responses to two honey bee-produced odors that are important for the mite to locate its host: nurse bee head space odor and (E)-β-ocimene, a honey bee brood pheromone. Previous work with the racemic compounds showed that they suppress the mite's olfactory response to its bee host, which led to incorrect host choice. Based on a structure-activity relationship, we predicted that the two most active compounds-cis-1-butoxy-5-(2'-methoxyethyl)cyclopent-2-ene, cy{4,1}, and (cis-1-ethoxy-5-(2'ethoxyethyl)cyclopent-2-ene, cy{2,2}-could have opposite active enantiomers. Here we studied the enantiomers of both ethers, whose preparation involved enzymatic resolution of racemic diol cis-5-(2'-hydroxyethyl)cyclopent-2-en-1-ol using Lipase AK with vinyl acetate. The racemic diol was prepared from commercially available 2,5-norbornadiene. We observed that the responses of the chemosensory organ to honey bee head space volatiles were significantly decreased by both enantiomers of cy{4,1} and cy{2,2}, but that responses to (E)-β-ocimene were decreased significantly only by (+)-cy{4,1} (1R,5S) and (-)-cy{2,2} (1S,5R) and not by their respective enantiomers. The importance of this result is that the racemates could be used to inhibit olfactory detection of bee odors by mites, without a loss in activity relative to the more expensive enantiopure compounds.

Exploiting the biosynthetic machinery of Streptomyces pilosus to engineer a water-soluble zirconium(iv) chelator.

PubMed

Richardson-Sanchez, Tomas; Tieu, William; Gotsbacher, Michael P; Telfer, Thomas J; Codd, Rachel

2017-07-21

The water solubility of a natural product-inspired octadentate hydroxamic acid chelator designed to coordinate Zr(iv)-89 has been improved by using a combined microbiological-chemical approach to engineer four ether oxygen atoms into the main-chain region of a methylene-containing analogue. First, an analogue of the trimeric hydroxamic acid desferrioxamine B (DFOB) that contained three main-chain ether oxygen atoms (DFOB-O 3 ) was generated from cultures of the native DFOB-producer Streptomyces pilosus supplemented with oxybis(ethanamine) (OBEA), which competed against the native 1,5-diaminopentane (DP) substrate during DFOB assembly. This precursor-directed biosynthesis (PDB) approach generated a suite of DFOB analogues containing one (DFOB-O 1 ), two (DFOB-O 2 ) or three (DFOB-O 3 ) ether oxygen atoms, with the latter produced as the major species. Log P measurements showed DFOB-O 3 was about 45 times more water soluble than DFOB. Second, a peptide coupling chain-extension reaction between DFOB-O 3 and the synthetic ether-containing endo-hydroxamic acid monomer 4-((2-(2-aminoethoxy)ethyl)(hydroxy)amino)-4-oxobutanoic acid (PBH-O 1 ) gave the water soluble tetrameric hydroxamic acid DFOB-O 3 -PBH-O 1 as an isostere of sparingly water soluble DFOB-PBH. The complex between DFOB-O 3 -PBH-O 1 and nat Zr(iv), examined as a surrogate measure of the radiolabelling procedure, analysed by LC-MS as the protonated adduct ([M + H] + , m/z obs = 855.2; m/z calc = 855.3), with supporting HRMS data. The use of a microbiological system to generate a water-soluble analogue of a natural product for downstream semi-synthetic chemistry is an attractive pathway for developing new drugs and imaging agents. The improved water solubility of DFOB-O 3 -PBH-O 1 could facilitate the synthesis and purification of downstream products, as part of the ongoing development of ligands optimised for Zr(iv)-89 immunological PET imaging.

Electrophilic fluorinating reagent mediated synthesis of fluorinated alpha-keto Ethers, benzil, and 6,6'-dialkoxy-2,2'-bipyridines.

PubMed

Manandhar, Sudha; Singh, Rajendra P; Eggers, Gary V; Shreeve, Jean'ne M

2002-09-06

Interactions of various fluorinated and nonfluorinated alcohols with trans-stilbene in the presence of electrophilic reagents were studied. Under neat conditions, reactions of trans-stilbene (1) with fluorinated alcohols, R(f)OH (R(f) = CF3CH2-, CFH2CH2-, CF3CF2CH2-, CF2H(CF2)3CH2-, (CF3)2CH-, (CF3)3C- (2a-f) in the presence of an electrophilic reagent, 1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor) or N,N-difluoro-2,2'-bipyridinium bis(tetrafluoroborate) (MEC-31), gave alpha-keto ethers (3a-f) and benzil (4) in good to moderate yields. alpha-Keto ether and benzil formation was very much dependent on the reaction time, the degree of fluorination of the alcohols, and whether a solvent such as CH3CN, DMF or DMA was utilized. In solution, alpha-keto ethers and benzil did not form. Interestingly, under neat conditions, nonfluorinated alcohols, ROH (R = CH3-, CH3CH2-, CH3CH2CH2-, CH3CH2CH2CH2-, CH3CH2CH2CH2CH2CH2-) (5g-k) did not react with trans-stilbene in the presence of MEC-31 but gave 6,6'-dialkoxy-2,2'-bipyridines (6g-k), regioselectively, in excellent isolated yields. On the other hand, fluorinated alcohols did not react with MEC-31. Reaction of MEC-31 with an excess of diethylene glycol (7) gave the bipyridine derivative (8) in 88% isolated yield. Reaction of 8 either with diethylaminosulfur trifluoride (DAST) or bis(2-methoxyethyl)aminosulfur trifluoride (Deoxofluor) readily produced the corresponding difluoro derivative (9) in 85% isolated yield. All new compounds have been characterized by spectroscopic and elemental analysis.

Poly(arylene ether)s containing pendent ethynyl groups

NASA Technical Reports Server (NTRS)

Hergenrother, Paul M. (Inventor); Jensen, Brian J. (Inventor)

1996-01-01

Poly(arylene ether)s containing pendent ethynyl and substituted ethynyl groups and poly(arylene ether) copolymers containing pendent ethynyl and substituted ethynyl groups are readily prepared from bisphenols containing ethynyl and substituted ethynyl groups. The resulting polymers are cured up to 350.degree. C. to provide crosslinked poly(arylene ether)s with good solvent resistance, high strength and modulus.

Poly(arylene ether)s containing pendent ethynyl groups

NASA Technical Reports Server (NTRS)

Hergenrother, Paul M. (Inventor); Jensen, Brian J. (Inventor)

1994-01-01

Poly(arylene ether)s containing pendent ethynyl and substituted ethynyl groups and poly(arylene ether) copolymers containing pendent ethynyl and substituted ethynyl groups are readily prepared from bisphenols containing ethynyl and substituted ethynyl groups. The resulting polymers are cured up to 350 C to provide crosslinked poly(arylene ether)s with good solvent resistance, high strength and modulus.

National Forum on Issues in Vocational Assessment (Atlanta, Georgia, September 20-22, 1984). The Issues Papers.

ERIC Educational Resources Information Center

Smith, Christopher, Ed.; Fry, Ronald, Ed.

The current state of the art in vocational assessment is explored in 46 papers: "Vocational Evaluation: An Experimental Trend in Vocational Assessment" (Nadolsky); "Certification for Teachers and Vocational Evaluation Specialists" (Meers); "Marketing Vocational Education" (Williamson); "Norms, Reliability, and Validity in Commercial Vocational…

Economics in Context

ERIC Educational Resources Information Center

Evensky, Jerry

2004-01-01

Academic departmentalization has limited the dimensionality and thus the richness of analysis in the social sciences. The author examines the case of a modern economics as an example. He reviews the ideas of Williamson (2000), who cites the limits of scope in the New Institutional Economics; Buchanan, who lays bare the ethical foundations of…

10. OVERALL VIEW OF THE MAIN LOBBY OF BUILDING 1; ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. OVERALL VIEW OF THE MAIN LOBBY OF BUILDING 1; SHOWING EGYPTIAN MOTIF DECORATIVE DETAIL OF THE ENGAGED COLUMNS, CORNICE & SOFFIT, DEDICATION PLAQUE, AND FLOOR MOSAICS; LOOKING SE. (Ryan & Harms) - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

78 FR 72914 - Changes in Flood Hazard Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-04

.... Forest Hill, Hill, TX 76119. 3219 California Parkway, Forest Hill, TX 76119. Travis City of Austin (13..., Austin, TX Road, 12th 78767. Floor, Austin, TX 78704. Travis Unincorporated The Honorable Travis County..., 700 Austin, TX 78767. Lavaca Street, 5th Floor, Suite 540, Austin, TX 78701. Williamson City of...

Art Libraries Section. Special Libraries Division. Papers.

ERIC Educational Resources Information Center

International Federation of Library Associations, The Hague (Netherlands).

Papers on art libraries, librarianship, and documentation presented at the 1982 International Federation of Library Associations (IFLA) conference include: (1) "The Tyranny of Distance: Art Libraries in Canada," a description by Mary F. Williamson of Canada's regional art libraries which serve both art students and the general public;…

5. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, IL Veterans Administration Medical Center. PLOT PLAN; DRAWING 1R, DATED SEPTEMBER 4, 1940. (8 x 10 negative) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

3. Photograph of an historic photograph in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Photograph of an historic photograph in the possession of the Engineer's Office of the Marion, Illinois Veterans Administration Medical Center. DINING HALL BUILDING #2, LOOKING NE; DATED JANUARY 31, 1942. - Veterans Administration Medical Center, Building No. 2, Old State Route 13 West, Marion, Williamson County, IL

16. Photograph of an historic photograph in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. Photograph of an historic photograph in the possession of the Engineer's Office of the Marion, IL Veterans Administration Medical Center. HOSPITAL BUILDING #1, LOOKING NE; DATED NOVEMBER 30, 1941. - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

A Yearning for Wholeness: Spirituality in Educational Philosophy

ERIC Educational Resources Information Center

Hurley, Angela

2012-01-01

Numerous popular figures currently espouse the importance of spirituality. Some prominent voices, such as Deepak Chopra, Marianne Williamson, and Eckhart Tolle, advocate a more spiritual existence, warning that the earth and humanity are engaged in a seismic change. The shift of spiritual leaders from fringe to fairly mainline attention is…

77 FR 72884 - Crystalline Silicon Photovoltaic Cells and Modules From China

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-06

... Silicon Photovoltaic Cells and Modules From China Determinations On the basis of the record \\1\\ developed... imports of crystalline silicon photovoltaic cells and modules from China, provided for in subheadings 8501... silicon photovoltaic cells and modules from China. Chairman Irving A. Williamson and Commissioner Dean A...

Science Fiction: Today and Tomorrow.

ERIC Educational Resources Information Center

Bretnor, Reginald, Ed.

A critical symposium on science fiction, this book features essays (by Ben Bova, Frederik Pohl, George Zebrowski, Frank Herbert, Theodore Sturgeon, Alan E. Nourse, Thomas N. Scortia, Reginald Bretnor, James Gunn, Alexei and Cory Panshin, Poul Anderson, Hal Clement, Anne McCaffrey, Gordon R. Dickson, and Jack Williamson) dealing with such subjects…

58. Photographic copy of historic medal, The Yellow Fever Medal, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

58. Photographic copy of historic medal, The Yellow Fever Medal, presented to the Portsmouth Naval Hospital by the Town Council of Portsmouth, 1856. (Portsmouth Naval Shipyard Museum, Portsmouth, VA) - Portsmouth Naval Hospital, Hospital Building, Rixey Place, bounded by Williamson Drive, Holcomb Road, & The Circle, Portsmouth, Portsmouth, VA

Inequity of Human Services: The Rural Tennessee Dilemma.

ERIC Educational Resources Information Center

Tennessee State Univ., Nashville.

Davidson, Williamson, Rutherford, and Cheatham counties of Tennessee were the setting for a study that sought to determine the types of health and social services provided to residents of rural areas and to assess the present status of the service delivery system. Interviews with both agency representatives and randomly selected household…

76 FR 66323 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

... part 60, written comments are being accepted concerning the significance of the nominated properties..., 11000807 Sullivan County Piney Flats Historic District, Main, McKamey, & Methodist Church Sts. & parts of... has been made for the following resources: TENNESSEE Williamson County Lamb--Stevens House...

The scope and limitations of intramolecular Nicholas and Pauson-Khand reactions for the synthesis of tricyclic oxygen- and nitrogen-containing heterocycles.

PubMed

Closser, Kristina D; Quintal, Miriam M; Shea, Kevin M

2009-05-15

We studied the scope and limitations of a tandem intramolecular Nicholas/Pauson-Khand strategy for the synthesis of tricyclic oxygen- and nitrogen-containing heterocycles. This methodology enables conversion of simple acyclic starting materials into a series of previously unknown heterocyclic architectures. For the preparation of cyclic ethers (Z = O), tricyclic [5,6,5]- through [5,9,5]-systems (m = 1, n = 1-4) are available with the [5,7,5]- and [5,8,5]-systems amenable to quick and efficient synthesis. Tricyclic [5,7,5]- and [5,8,5]-amine-containing (Z = NTs) heterocycles can be successfully prepared. Attempts to make larger ring systems (Z = O, m = 2; Z = O, n = 5; or Z = NTs, n = 4-5) or prepare lactones via Nicholas reactions with carboxylic acid nucleophiles (available via oxidation of alcohol nucleophiles, Z = O) result in decomposition or dimerization. The latter process enables formation of 14-, 16-, and 18-membered ring diolides when using carboxylic acid nucleophiles. We also investigated the use of chiral amine promoters in the Pauson-Khand step but found no asymmetric induction.

Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use.

PubMed

Manual Kollareth, Denny Joseph; Chang, Chuchun L; Hansen, Inge H; Deckelbaum, Richard J

2018-03-01

Radiolabeled cholesteryl ethers are widely used as non-metabolizable tracers for lipoproteins and lipid emulsions in a variety of in vitro and in vivo experiments. Since cholesteryl ethers do not leave cells after uptake and are not hydrolyzed by mammalian cellular enzymes, these compounds can act as markers for cumulative cell uptakes of labeled particles. We have employed [ 3 H]cholesteryl oleoyl ether to study the uptake and distribution of triglyceride-rich emulsion particles on animal models. However, questionable unexpected results compelled us to analyze the stability of these ethers. We tested the stability of two commercially available radiolabeled cholesteryl ethers - [ 3 H]cholesteryl oleoyl ether and [ 3 H]cholesteryl hexadecyl ether from different suppliers, employing in vitro , in vivo and chemical model systems. Our results show that, among the two cholesteryl ethers tested, one ether was hydrolyzed to free cholesterol in vitro , in vivo and chemically under alkaline hydrolyzing agent. Free cholesterol, unlike cholesteryl ether, can then re-enter the circulation leading to confounding results. The other ether was not hydrolyzed to free cholesterol and remained as a stable ether. Hence, radiolabeled cholesteryl ethers should be analyzed for biological stability before utilizing them for in vitro or in vivo experiments.

Site-Selective Copper-Catalyzed Amination and Azidation of Arenes and Heteroarenes via Deprotonative Zincation.

PubMed

Hendrick, Charles E; Bitting, Katie J; Cho, Seoyoung; Wang, Qiu

2017-08-23

Arene amination is achieved by site-selective C-H zincation followed by copper-catalyzed coupling with O-benzoylhydroxylamines under mild conditions. Key to this success is ortho-zincation mediated by lithium amidodiethylzincate base that is effective for a wide range of arenes, including nonactivated arenes bearing simple functionalities such as fluoride, chloride, ester, amide, ether, nitrile, and trifluoromethyl groups as well as heteroarenes including indole, thiophene, pyridine, and isoquinoline. An analogous C-H azidation is also accomplished using azidoiodinane for direct introduction of a useful azide group onto a broad scope of arenes and heteroarenes. These new transformations offer rapid access to valuable and diverse chemical space of aminoarenes. Their broad applications in organic synthesis and drug discovery are demonstrated in the synthesis of novel analogues of natural product (-)-nicotine and antidepressant sertraline by late-stage amination and azidation reactions.

Stereodivergent Mannich reaction of bis(trimethylsilyl)ketene acetals with N-tert-butanesulfinyl imines by Lewis acid or Lewis base activation, a one-pot protocol to obtain chiral β-amino acids.

PubMed

Cantú-Reyes, Margarita; Alvarado-Beltrán, Isabel; Ballinas-Indilí, Ricardo; Álvarez-Toledano, Cecilio; Hernández-Rodríguez, Marcos

2017-09-20

We report a one-pot synthesis of chiral β 2,2,3 -amino acids by the Mannich addition of bistrimethylsilyl ketene acetals to N-tert-butanesulfinyl imines followed by the removal of the chiral auxiliary. The synthesis and isolation of pure β-amino acid hydrochlorides were conducted under mild conditions, without strong bases and this method is operationally simple. The stereoselective reaction was promoted by two different activation methods that lead to different stereoisomers: (1) Lewis Acid (LA) catalysis with boron trifluoride diethyl etherate and (2) Lewis Base (LB) catalysis with tetrabutylammonium difluorotriphenylsilicate. The reaction presented good diastereoselectivity with LB activation and moderate to good dr with LA catalysis. The exceptions in both protocols were imines with electron donating groups in the aromatic ring.

Synthesis of square-planar aluminum(III) complexes.

PubMed

Thompson, Emily J; Myers, Thomas W; Berben, Louise A

2014-12-15

The synthesis of two four-coordinate and square planar (SP) complexes of aluminum(III) is presented. Reaction of a phenyl-substituted bis(imino)pyridine ligand that is reduced by two electrons, Na2((Ph)I2P(2-)), with AlCl3 afforded five-coordinate [((Ph)I2P(2-))Al(THF)Cl] (1). Square-planar [((Ph)I2P(2-))AlCl] (2) was obtained by performing the same reaction in diethyl ether followed by lyphilization of 2 from benzene. The four-coordinate geometry index for 2, τ4, is 0.22, where 0 would be a perfectly square-planar molecule. The analogous aluminum hydride complex, [((Ph)I2P(2-))AlH] (3), is also square-planar, and was characterized crystallographically and has τ4=0.13. Both 2 and 3 are Lewis acidic and bind 2,6-lutidine. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Regulation of glycerolipid metabolism in Tetrahymena species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, C.R.

1988-01-01

A simplified extraction system was developed to study the in vivo incorporation of 1-{sup 14}C-acetate into the glycerolipids of Tetrahymena. Cells incubated in the presence of 1-{sup 14}C-sodium acetate were spotted onto pre-acidified TLC plate and extracted by developing the plates in ethanol, and thereafter developing with 90:10:1 (v:v:v) hexane-ether-acetic acid. The synthesis of glycerolipids in Tetrahymena thermophila and Tetrahymena furgasoni, was studied using the above assay system. The level of triacylglycerol was elevated at stationary phase, whereas phospholipid levels were depressed. A shift from phospholipid synthesis to triacylglycerol synthesis occurred when growth was inhibited in Tetrahymena thermophila. The signalmore » for this shift in Tetrahymena thermophila is apparently a decrease in protein synthesis due either to culture age, the presence of cycloheximide, or the removal of amino acid from the synthetic medium. In exponentially growing Tetrahymena thermophila cycloheximide stimulated the incorporation of 1-{sup 14}C-acetate into triacylglycerol and decreased the incorporation into phospholipid, while stopping the incorporation of 1-{sup 14}C-serine into TCA precipitable material from the cells. Similar alterations in glycerolipid synthesis were obtained when amino acids were deleted from the medium. An in vitro assay system was developed to measure the incorporation of 1-{sup 14}C-palmitic acid into triacylglycerol and phospholipid using conditions similar to those of the in vivo studies.« less

Isostrychnine synthesis mediated by hypervalent iodine reagent.

PubMed

Jacquemot, Guillaume; Maertens, Gaëtan; Canesi, Sylvain

2015-05-18

Althought there are several reported synthetic routes to strychnine, one of the most widely recognized alkaloids, we report an unexplored route with an oxidative dearomatizing process mediated by hypervalent iodine as the key step. The new syntheses of isostrychnine and strychnine have been achieved from an readily available phenol in nine and ten steps. In addition to the key step, these syntheses involve an aza Michael-ether-enol tandem transformation, two heck type cyclizations, a reductive isomerization, and a double reductive amination in cascade leading to the alkaloid main core. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Monomethyl Ether *Dimer Acids Dioxane Ethane Ethylene Glycol Monophenyl Ether *Ethoxylates, Misc. Ethylene Glycol Dimethyl Ether Ethylene Glycol Monobutyl Ether Ethylene Glycol Monoethyl Ether Ethylene Glycol...

Kinetics and Pathways for the Debromination of Polybrominated Diphenyl Ethers by Bimetallic and Nanoscale Zerovalent Iron: Effects of Particle Properties and Catalyst

PubMed Central

Zhuang, Yuan; Jin, Luting; Luthy, Richard G.

2012-01-01

Polybrominated diphenyl ethers (PBDEs) are recognized as a new class of widely-distributed and persistent contaminants for which effective treatment and remediation technologies are needed. In this study, two kinds of commercially available nanoscale Fe° slurries (Nanofer N25 and N25S), a freeze-dried laboratory-synthesized Fe° nanoparticle (nZVI), and their palladized forms were used to investigate the effect of particle properties and catalyst on PBDE debromination kinetics and pathways. Nanofers and their palladized forms were found to debrominate PBDEs effectively. The laboratory-synthesized Fe° nanoparticles also debrominated PBDEs, but were slower due to deactivation by the freeze-drying and stabilization processes in the laboratory synthesis. An organic modifier, polyacrylic acid (PAA), bound on N25S slowed PBDE debromination by a factor of three to four compared to N25. The activity of palladized nZVI (nZVI/Pd) was optimized at 0.3 Pd/Fe wt% in our system. N25 could debrominate selected environmentally-abundant PBDEs, including BDE 209, 183, 153, 99, and 47, to end products di-BDEs, mono-BDEs and diphenyl ether (DE) in one week, while nZVI/Pd (0.3 Pd/Fe wt%) mainly resulted in DE as a final product. Step-wise major PBDE debromination pathways by unamended and palladized Fe° are described and compared. Surface precursor complex formation is an important limiting factor for palladized Fe° reduction as demonstrated by PBDE pathways where steric hindrance and rapid sequential debromination of adjacent bromines play an important role. PMID:22732301

Ruthenium Catalyzed Diastereo- and Enantioselective Coupling of Propargyl Ethers with Alcohols: Siloxy-Crotylation via Hydride Shift Enabled Conversion of Alkynes to π-Allyls

PubMed Central

Liang, Tao; Zhang, Wandi; Chen, Te-Yu; Nguyen, Khoa D.; Krische, Michael J.

2015-01-01

The first enantioselective carbonyl crotylations through direct use of alkynes as chiral allylmetal equivalents are described. Chiral ruthenium(II) complexes modified by Josiphos (SL-J009-1) catalyze the C-C coupling of TIPS-protected propargyl ether 1a with primary alcohols 2a-2o to form products of carbonyl siloxy-crotylation 3a-3o, which upon silyl deprotection-reduction deliver 1,4-diols 5a-5o with excellent control of regio-, anti-diastereo- and enantioselectivity. Structurally related propargyl ethers 1b and 1c bearing ethyl- and phenyl-substituents engage in diastereo- and enantioselective coupling, as illustrated in the formation of adducts 5p and 5q, respectively. Selective mono-tosylation of diols 5a, 5c, 5e, 5f, 5k and 5m is accompanied by spontaneous cyclization to deliver the trans-2,3-disubstituted furans 6a, 6c, 6e, 6f, 6k and 6m, respectively. Primary alcohols 2a, 2l and 2p were converted to the siloxy-crotylation products 3a, 3l and 3p, which upon silyl deprotection-lactol oxidation were transformed to the trans-4,5-disubstituted γ-butyrolactones 7a, 7l and 7p. The formation of 7p represents a total synthesis of (+)-trans-whisky lactone. Unlike closely related ruthenium catalyzed alkyne-alcohol C-C couplings, deuterium labeling studies provide clear evidence of a novel 1,2-hydride shift mechanism that converts metal-bound alkynes to π-allyls in the absence of intervening allenes. PMID:26418572

Dehalogenation of Polybrominated Diphenyl Ethers and Polychlorinated Biphenyl by Bimetallic, Impregnated, and Nanoscale Zerovalent Iron

PubMed Central

Zhuang, Yuan; Ahn, Sungwoo; Seyfferth, Angelia L.; Masue-Slowey, Yoko; Fendorf, Scott; Luthy, Richard G.

2011-01-01

Nanoscale zerovalent iron particles (nZVI), bimetallic nanoparticles (nZVI/Pd), and nZVI/Pd impregnated activated carbon (nZVI/Pd-AC) composite particles were synthesized and investigated for their effectiveness to remove polybrominated diphenyl ethers (PBDEs) and/or polychlorinated biphenyls (PCBs). Palladization of nZVI promoted the dehalogenation kinetics for mono- to tri-BDEs and 2,3,4-trichlorobiphenyl (PCB 21). Compared to nZVI, the iron-normalized rate constants for nZVI/Pd were about 2-, 3-, and 4-orders of magnitude greater for tri-, di-, and mono-BDEs, respectively, with diphenyl ether as a main reaction product. The reaction kinetics and pathways suggest an H-atom transfer mechanism. The reaction pathways with nZVI/Pd favor preferential removal of para-halogens on PBDEs and PCBs. X-ray fluorescence mapping of nZVI/Pd-AC showed that Pd mainly deposits on the outer part of particles, while Fe was present throughout the activated carbon particles. While BDE 21 was sorbed onto activated carbon composites quickly, debromination was slower compared to reaction with freely dispersed nZVI/Pd. Our XPS and chemical data suggest about 7% of the total iron within the activated carbon was zero-valent, which shows the difficulty with in-situ synthesis of a significant fraction of zero-valent iron in the micro-porous material. Related factors that likely hinder the reaction with nZVI/Pd-AC are the heterogenous distribution of nZVI and Pd on activated carbon and/or immobilization of hydrophobic organic contaminants at the adsorption sites thereby inhibiting contact with nZVI. PMID:21557574

Tissue-selective alteration of ethanolamine plasmalogen metabolism in dedifferentiated colon mucosa.

PubMed

Lopez, Daniel H; Bestard-Escalas, Joan; Garate, Jone; Maimó-Barceló, Albert; Fernández, Roberto; Reigada, Rebeca; Khorrami, Sam; Ginard, Daniel; Okazaki, Toshiro; Fernández, José A; Barceló-Coblijn, Gwendolyn

2018-08-01

Human colon lipid analysis by imaging mass spectrometry (IMS) demonstrates that the lipid fingerprint is highly sensitive to a cell's pathophysiological state. Along the colon crypt axis, and concomitant to the differentiation process, certain lipid species tightly linked to signaling (phosphatidylinositols and arachidonic acid (AA)-containing diacylglycerophospholipids), change following a rather simple mathematical expression. We extend here our observations to ethanolamine plasmalogens (PlsEtn), a unique type of glycerophospholipid presenting a vinyl ether linkage at sn-1 position. PlsEtn distribution was studied in healthy, adenomatous, and carcinomatous colon mucosa sections by IMS. In epithelium, 75% of PlsEtn changed in a highly regular manner along the crypt axis, in clear contrast with diacyl species (67% of which remained constant). Consistently, AA-containing PlsEtn species were more abundant at the base, where stem cells reside, and decreased while ascending the crypt. In turn, mono-/diunsaturated species experienced the opposite change. These gradients were accompanied by a gradual expression of ether lipid synthesis enzymes. In lamina propria, 90% of stromal PlsEtn remained unchanged despite the high content of AA and the gradient in AA-containing diacylglycerophospholipids. Finally, both lipid and protein gradients were severely affected in polyps and carcinoma. These results link PlsEtn species regulation to cell differentiation for the first time and confirm that diacyl and ether species are differently regulated. Furthermore, they reaffirm the observations on cell lipid fingerprint image sensitivity to predict cell pathophysiological status, reinforcing the translational impact both lipidome and IMS might have in clinical research. Copyright © 2018 Elsevier B.V. All rights reserved.

Synthesis, supramolecular behavior, and in vitro photodynamic activities of novel zinc(II) phthalocyanines "side-strapped" with crown ether bridges.

PubMed

Chen, Xing-Wei; Ke, Mei-Rong; Li, Xing-Shu; Lan, Wen-Liang; Zhang, Miao-Fen; Huang, Jian-Dong

2013-12-01

Two new tetra- or di-α-substituted zinc(II) phthalocyanines 5 and 6 have been prepared through a "side-strapped" method. In the molecules, the adjacent benzene rings of the phthalocyanine core are linked at α-position through a triethylene glycol bridge to form a hybrid aza-/oxa-crown ether. The tetra-α-substituted phthalocyanine 5 shows an eclipsed self-assembly property in CH2Cl2 and the effect on the di-α-substituted analogue 6 is significantly weakened. Furthermore, the crown ethers of these compounds can selectively complex with Fe(3+) or Cu(2+) ion in DMF, leading to formation of J-aggregated nano-assemblies, which can be disaggregated in the presence of some organic or inorganic ligands, such as triethylamine, tetramethylethylenediamine, CH3COO(-), or OH(-). In addition, both compounds are efficient singlet oxygen generators with the singlet oxygen quantum yields (Φ(Δ)) of 0.54-0.74 in DMF relative to unsubstituted zinc(II) phthalocyanine (Φ(Δ)=0.56). They exhibit photodynamic activities toward HepG2 human hepatocarcinoma cells, but the compound 6, which has more than 40-fold lower IC50 value (0.08 μM) compared to the analogue 5 (IC50=3.31 μM), shows remarkablely higher in vitro photocytotoxicity due to its significantly higher cellular uptake and singlet oxygen generation efficiency. The results suggest that these compounds can serve as promising multifunctional materials both in (opto)electronic field and photodynamic therapy. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Could LogP be a principal determinant of biological activity in 18-crown-6 ethers? Synthesis of biologically active adamantane-substituted diaza-crowns.

PubMed

Supek, Fran; Ramljak, Tatjana Šumanovac; Marjanović, Marko; Buljubašić, Maja; Kragol, Goran; Ilić, Nataša; Smuc, Tomislav; Zahradka, Davor; Mlinarić-Majerski, Kata; Kralj, Marijeta

2011-08-01

18-crown-6 ethers are known to exert their biological activity by transporting K(+) ions across cell membranes. Using non-linear Support Vector Machines regression, we searched for structural features that influence antiproliferative activity in a diverse set of 19 known oxa-, monoaza- and diaza-18-crown-6 ethers. Here, we show that the logP of the molecule is the most important molecular descriptor, among ∼1300 tested descriptors, in determining biological potency (R(2)(cv) = 0.704). The optimal logP was at 5.5 (Ghose-Crippen ALOGP estimate) while both higher and lower values were detrimental to biological potency. After controlling for logP, we found that the antiproliferative activity of the molecule was generally not affected by side chain length, molecular symmetry, or presence of side chain amide links. To validate this QSAR model, we synthesized six novel, highly lipophilic diaza-18-crown-6 derivatives with adamantane moieties attached to the side arms. These compounds have near-optimal logP values and consequently exhibit strong growth inhibition in various human cancer cell lines and a bacterial system. The bioactivities of different diaza-18-crown-6 analogs in Bacillus subtilis and cancer cells were correlated, suggesting conserved molecular features may be mediating the cytotoxic response. We conclude that relying primarily on the logP is a sensible strategy in preparing future 18-crown-6 analogs with optimized biological activity. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Solid state, thermal synthesis of site-specific protein-boron cluster conjugates and their physicochemical and biochemical properties.

PubMed

Goszczyński, Tomasz M; Kowalski, Konrad; Leśnikowski, Zbigniew J; Boratyński, Janusz

2015-02-01

Boron clusters represent a vast family of boron-rich compounds with extraordinary properties that provide the opportunity of exploitation in different areas of chemistry and biology. In addition, boron clusters are clinically used in boron neutron capture therapy (BNCT) of tumors. In this paper, a novel, in solid state (solvent free), thermal method for protein modification with boron clusters has been proposed. The method is based on a cyclic ether ring opening in oxonium adduct of cyclic ether and a boron cluster with nucleophilic centers of the protein. Lysozyme was used as the model protein, and the physicochemical and biological properties of the obtained conjugates were characterized. The main residues of modification were identified as arginine-128 and threonine-51. No significant changes in the secondary or tertiary structures of the protein after tethering of the boron cluster were found using mass spectrometry and circular dichroism measurements. However, some changes in the intermolecular interactions and hydrodynamic and catalytic properties were observed. To the best of our knowledge, we have described the first example of an application of cyclic ether ring opening in the oxonium adducts of a boron cluster for protein modification. In addition, a distinctive feature of the proposed approach is performing the reaction in solid state and at elevated temperature. The proposed methodology provides a new route to protein modification with boron clusters and extends the range of innovative molecules available for biological and medical testing. Copyright © 2014 Elsevier B.V. All rights reserved.

Chelating ionic liquids for reversible zinc electrochemistry.

PubMed

Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

2013-05-21

Advanced, high energy-density, metal-air rechargeable batteries, such as zinc-air, are of intense international interest due to their important role in energy storage applications such as electric and hybrid vehicles, and to their ability to deal with the intermittency of renewable energy sources such as solar and wind. Ionic liquids offer a number of ideal thermal and physical properties as potential electrolytes in such large-scale energy storage applications. We describe here the synthesis and characterisation of a family of novel "chelating" ILs designed to chelate and solubilize the zinc ions to create electrolytes for this type of battery. These are based on quaternary alkoxy alkyl ammonium cations of varying oligo-ether side chains and anions such as p-toluene sulfonate, bis(trifluoromethylsulfonyl)amide and dicyanoamides. This work shows that increasing the ether chain length in the cation from two to four oxygens can increase the ionic conductivity and reduce the melting point from 67 °C to 15 °C for the tosylate system. Changing the anion also plays a significant role in the nature of the zinc deposition electrochemistry. We show that zinc can be reversibly deposited from [N(222(20201))][NTf2] and [N(222(202020201))][NTf2] beginning at -1.4 V and -1.7 V vs. SHE, respectively, but not in the case of tosylate based ILs. This indicates that the [NTf2] is a weaker coordinating anion with the zinc cation, compared to the tosylate anion, allowing the coordination of the ether chain to dominate the behavior of the deposition and stripping of zinc ions.

Particle-tracking investigation of the retention of sucker larvae emerging from spawning grounds in Upper Klamath Lake, Oregon

USGS Publications Warehouse

Wood, Tamara M.; Wherry, Susan A.; Simon, David C.; Markle, Douglas F.

2014-01-01

This study had two objectives: (1) to use the results of an individual-based particle-tracking model of larval sucker dispersal through the Williamson River delta and Upper Klamath Lake, Oregon, to interpret field data collected throughout Upper Klamath and Agency Lakes, and (2) to use the model to investigate the retention of sucker larvae in the system as a function of Williamson River flow, wind, and lake elevation. This is a follow-up study to work reported in Wood and others (2014) in which the hydrodynamic model of Upper Klamath Lake was combined with an individual-based, particle-tracking model of larval fish entering the lake from spawning areas in the Williamson River. In the previous study, the performance of the model was evaluated through comparison with field data comprising larval sucker distribution collected in 2009 by The Nature Conservancy, Oregon State University (OSU), and the U.S. Geological Survey, primarily from the (at that time) recently reconnected Williamson River Delta and along the eastern shoreline of Upper Klamath Lake, surrounding the old river mouth. The previous study demonstrated that the validation of the model with field data was moderately successful and that the model was useful for describing the broad patterns of larval dispersal from the river, at least in the areas surrounding the river channel immediately downstream of the spawning areas and along the shoreline where larvae enter the lake. In this study, field data collected by OSU throughout the main body of Upper Klamath Lake, and not just around the Williamson River Delta, were compared to model simulation results. Because the field data were collected throughout the lake, it was necessary to include in the simulations larvae spawned at eastern shoreline springs that were not included in the earlier studies. A complicating factor was that the OSU collected data throughout the main body of the lake in 2011 and 2012, after the end of several years of larval drift collection in the Williamson River by the U.S. Geological Survey. Those larval drift data provided necessary boundary-condition information for the earlier studies, but there were no measured boundary conditions for larval input into model simulations during the years of this study (2011−12). Therefore, we developed a method to estimate a time series of larval drift in the Williamson River, and of the emergence of larvae from the gravel at the eastern shoreline springs, that captured the approximate timing of the larval pulse of the Lost River sucker (Deltistes luxatus) and shortnose sucker (Chasmistes brevirostris) and the relative magnitude of the pulses by species and spawning location. The method is not able to predict larval drift on any given day, but it can reasonably predict the approximate temporal progression of the larval drift through the season, based on counts of adult suckers returning to spawn. The accuracy in the timing of the larval pulses is not better than about plus or minus 5 days. Model results and field data were consistent in the basic progression of both catch per unit effort (CPUE) and larval length through time. The model simulation results also duplicated some of the characteristics of the spatial patterns of density in the field data, notably the tendency for high larval densities closer to the eastern and western shorelines. However, the model simulations could not explain high densities in the northern part of the lake or far into Ball Bay, locations that are far from the source of larvae in the Williamson River or eastern shoreline springs (as measured along the predominant transport pathways simulated in the model). This suggests the possibility of unaccounted-for spawning areas in the northern part of the lake and also that the period during which larvae are transported passively by the currents is shorter than the 46 days simulated in the model. Similarly, the progression of larval lengths in the field data is not a simple progression from smaller to larger fish away from sources in the river and springs, as simulated by the particle-tracking model; the smallest fish were caught at different times near the Williamson River, in the northwestern part of the lake, and in the southernmost part of the lake. This again suggests that fish may be spawning at places other than the river and eastern springs, that our understanding of larval transport is incomplete, or both. The model was used to run 96 numerical “experiments” in which lake elevation, river discharge, and wind forcing were varied systematically in order to investigate the sensitivity of particle retention to each variable, and with particular emphasis on the idea of managing lake elevation to control emigration. The estimates of particle retention cannot be equated directly to retention of fish larvae, primarily because there was no mortality included in the simulations, but the relative comparison of retention and emigration around the matrix of experimental conditions provided several “big picture” results: - Variables that cannot be controlled—winds and discharge—had the largest effect on retention. For example, at the lowest river discharge (20 cubic meters per second), simulated retention was high regardless of wind or lake elevation, whereas at the highest river discharge (100 cubic meters per second), retention was low regardless of wind or lake elevation. - When river discharge and wind were held constant, a higher elevation delayed the onset of the most rapid exit of particles by 1 (from the springs) to 4 (from the river) days, but did not determine overall retention. Only under the combination of conditions consisting of low discharge (50 cubic meters per second or less) and strong wind reversals for several days was there a consistent effect of lake elevation on overall retention several weeks into the simulation, and, under those conditions, retention was at the high end of the possible range regardless of lake elevation. - Under most combinations of conditions tested, after particles had been in the system for several days, the complex interaction between wind, elevation, and river discharge resulted in particle pathways, and therefore retention, being highly variable and unpredictable, at which point controlling lake elevation could not produce a predictable result. Therefore, on the basis of the model predictions, managing lake elevation probably is not a way to reliably provide any particular level of retention.

Tornado disaster -- Texas, May 1997.

PubMed

1997-11-14

On May 27, 1997, multiple tornadoes swept through Williamson and Travis counties in central Texas. The tornadoes caused 32 injuries, 29 deaths, and an estimated $20 million in personal and commercial insured losses. This report summarizes the injuries and deaths associated with these tornadoes based on information from emergency department and hospital records and death certificates.

ARC-2009-ACD09-0155-020

NASA Image and Video Library

2009-07-28

International Space University (ISU) and Singularity University (SU) Emerging Space Nations Panel held at NASA's Ames Research Center 2009 host site. Angie Bukley, ISU SSP09 program director, speaks with the panel moderator, Ray Williamson, ISU SSP09 distinguished lecturer and executive director of the Secure World Foundation, Superior, Colo., before the discussion begins.

ARC-2009-ACD09-0155-013

NASA Image and Video Library

2009-07-28

International Space University (ISU) and Singularity University (SU) Emerging Space Nations Panel held at NASA's Ames Research Center 2009 host site. Angie Bukley, ISU SSP09 program director, speaks with the panel moderator, Ray Williamson, ISU SSP09 distinguished lecturer and executive director of the Secure World Foundation, Superior, Colo., before the discussion begins.

ARC-2009-ACD09-0155-010

NASA Image and Video Library

2009-07-28

International Space University (ISU) and Singularity University (SU) Emerging Space Nations Panel held at NASA's Ames Research Center 2009 host site. Angie Bukley, ISU SSP09 program director, speaks with the panel moderator, Ray Williamson, ISU SSP09 distinguished lecturer and executive director of the Secure World Foundation, Superior, Colo., before the discussion begins.

ARC-2009-ACD09-0155-018

NASA Image and Video Library

2009-07-28

International Space University (ISU) and Singularity University (SU) Emerging Space Nations Panel held at NASA's Ames Research Center 2009 host site. Angie Bukley, ISU SSP09 program director, speaks with the panel moderator, Ray Williamson, ISU SSP09 distinguished lecturer and executive director of the Secure World Foundation, Superior, Colo., before the discussion begins.

ARC-2009-ACD09-0155-024

NASA Image and Video Library

2009-07-28

International Space University (ISU) and Singularity University (SU) Emerging Space Nations Panel held at NASA's Ames Research Center 2009 host site. Angie Bukley, ISU SSP09 program director, speaks with the panel moderator, Ray Williamson, ISU SSP09 distinguished lecturer and executive director of the Secure World Foundation, Superior, Colo., before the discussion begins.

ARC-2009-ACD09-0155-006

NASA Image and Video Library

2009-07-28

International Space University (ISU) and Singularity University (SU) Emerging Space Nations Panel held at NASA's Ames Research Center 2009 host site. Angie Bukley, ISU SSP09 program director, speaks with the panel moderator, Ray Williamson, ISU SSP09 distinguished lecturer and executive director of the Secure World Foundation, Superior, Colo., before the discussion begins.

Counting “exotics”

Treesearch

Qinfeng Guo

2011-01-01

An introduced or exotic species is commonly defined as an organism accidentally or intentionally introduced to a new location by human activity (Williamson 1996; Richardson et al. 2000; Guo and Ricklefs 2010). However, the counting of exotics is often inconsistent. For example, in the US, previously published plant richness data for each state are only those either...

Rigorous Schools and Classrooms: Leading the Way

ERIC Educational Resources Information Center

Williamson, Ronald; Blackburn, Barbara R.

2010-01-01

Turn your school into a student-centered learning environment, where rigor is at the heart of instruction in every classroom. From the bestselling author of "Rigor is Not a Four-Letter Word," Barbara Blackburn, and award-winning educator Ronald Williamson, this comprehensive guide to establishing a schoolwide culture of rigor is for principals and…

Educating Silicon Valley: Corporate Education Reform and the Reproduction of the Techno-Economic Revolution

ERIC Educational Resources Information Center

Williamson, Ben

2017-01-01

Silicon Valley's high-tech companies, tech-philanthropists, startups, and culture of venture capital are "the centre of a techno-economic revolution" that is "now spreading outwards across the world, with major societal effects and implications" (Duff 2016, 5). In this article, Ben Williamson traces and maps how education is…

Federal Overreach and Common Core. White Paper No. 133

ERIC Educational Resources Information Center

Evers, Williamson M.

2015-01-01

This report provides the historical background and interpretive analysis needed to understand controversies surrounding Common Core and its associated tests. In this report, Williamson M. Evers presents a revised and expanded version of his expert report for "Jindal v. United States Department of Education et al.," No. 14-CV- 534 (M.D.…

Receptivity toward Assistive Computer Technology by Non-Users Who Are Blind/Visually Impaired

ERIC Educational Resources Information Center

Leff, Lisa

2012-01-01

The non-use of assistive computer technology by some people who are legallyblind/visually-impaired was investigated to determine the reasons for lack of interest (Chiang, Cole, Gupta, Kaiser, & Starren, 2006; Williamson, Wright, Schauder & Bow, 2001). Social and psychological factors implicated in non-interest were determined by profiling…

5. DETAIL VIEW OF THE EGYPTIAN MOTIF DECORATIVE ELEMENTS OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. DETAIL VIEW OF THE EGYPTIAN MOTIF DECORATIVE ELEMENTS OF BUILDING 1'S MAIN ENTRY TOWER (INCLUDING THE ENGAGED COLUMN CAPITALS, PILASTERS & CAPITALS, CORNICES, AND TERRA COTTA EAGLES); LOOKING SW FROM THE E WING ROOF. (Ryan) - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

Radicalizing the Ebony Tower: Black Colleges and the Black Freedom Struggle in Mississippi. Reflective History

ERIC Educational Resources Information Center

Williamson, Joy Ann

2008-01-01

This path-breaking examination of Black colleges in Mississippi during Civil Rights and Black Power Movements offers a unique opportunity to understand how institutions are transformed into libratory agents. Williamson examines how campus constituents negotiated and clashed over local, state, and national pressures against the backdrop of the…

Science Fiction: The Academic Awakening.

ERIC Educational Resources Information Center

McNelly, Willis E., Ed.

This book provides background information on science fiction for teachers of English at any level who are approaching science fiction for the first time. Contents are: an introduction by W.E. McNelly; "SF in the Classroom" by J. Williamson; "Second Thoughts on the Course in Science Fiction" by M.R. Hillegas; "Flatland and Beyond: Characterization…

17. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, IL Veterans Administration Medical Center. FRONT (NORTH) ELEVATION; DRAWING 1-7R, DATED SEPTEMBER 4, 1940. (8 x 10 negative) - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

1. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, Illinois Veterans Administration Medical Center. (PLANS & ELEVATIONS); DRAWING 14-1R, DATED SEPTEMBER 4, 1940. (8 x 10 negative) - Veterans Administration Medical Center, Building No. 14, Old State Route 13 West, Marion, Williamson County, IL

4. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, Illinois Veterans Administration Medical Center. (PLANS, ELEVATIONS & DETAILS); DRAWING 8-1R, DATED SEPTEMBER 4, 1940. (8 x 10 negative) - Veterans Administration Medical Center, Building No. 8, Old State Route 13 West, Marion, Williamson County, IL

18. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, IL Veterans Administration Medical Center. SIDE (EAST) ELEVATION & SIDE (WEST) ELEVATION; DRAWING 1-9R, DATED SEPTEMBER 4, 1940. - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

23. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, IL Veterans Administration Medical Center. TYPICAL LOBBY DETAILS; DRAWING 1-21R, DATED SEPTEMBER 4, 1940. (8 x 10 negative) - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

4. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Photograph of a line drawing in the possession of the Engineer's office of the Marion, Illinois Veterans Administration Medical Center. (PLANS, ELEVATIONS & DETAILS); DRAWING 13-1R, DATED SEPTEMBER 4, 1940. (8 x 10 negative) - Veterans Administration Medical Center, Building No. 13, Old State Route 13 West, Marion, Williamson County, IL

1. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, Illinois Veterans Administration Medical Center. (PLAN, ELEVATIONS, & SECTIONS); DRAWING 15-1R, DATED SEPTEMBER 4, 1940. (8 x 10 negative) - Veterans Administration Medical Center, Building No. 15, Old State Route 13 West, Marion, Williamson County, IL

15. Photograph of an historic photograph in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. Photograph of an historic photograph in the possession of the Engineer's Office of the Marion, IL Veterans Administration Medical Center. HOSPITAL BUILDING #1; E & N (FRONT) ELEVATIONS, LOOKING SW; DATED MAY 18, 1942. - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

22. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, IL Veterans Administration Medical Center. MAIN LOBBY & ELEVATOR LOBBY DETAILS; DRAWING 1-20R, DATED SEPTEMBER 4, 1940. - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

U.S. Army Research Laboratory Meteorological Measurements for Joint Urban 2003

DTIC Science & Technology

2009-09-01

identical system operated by Arizona State University south to southeast of the CBD. The ARL Lidar system was set up atop a four-story parking garage ... Stereo Height and Motion Analysis: Applications, Fourth Winds Workshop, WMO, 1998. Chang, S. S.; Huynh, G. D.; Klipp, C. L.; Williamson, C. C

The Continuum Versus Categorical Debate on Eating Disorders: Implications for Counselors

ERIC Educational Resources Information Center

Perosa, Linda M.; Perosa, Sandra L.

2004-01-01

The authors summarize a study by D. A. Williamson et al. (2002) in which clinical groups with anorexia nervosa, bulimia nervosa, eating disorder not otherwise specified, and binge eating disorder were contrasted with nonclinical groups of participants (i.e., obese and normal weight). The eating disorder groups were qualitatively different. Also,…

Estimation of lattice strain in nanocrystalline RuO2 by Williamson-Hall and size-strain plot methods.

PubMed

Sivakami, R; Dhanuskodi, S; Karvembu, R

2016-01-05

RuO2 nanoparticles (RuO2 NPs) have been successfully synthesized by the hydrothermal method. Structure and the particle size have been determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM). UV-Vis spectra reveal that the optical band gap of RuO2 nanoparticles is red shifted from 3.95 to 3.55eV. BET measurements show a high specific surface area (SSA) of 118-133m(2)/g and pore diameter (10-25nm) has been estimated by Barret-Joyner-Halenda (BJH) method. The crystallite size and lattice strain in the samples have been investigated by Williamson-Hall (W-H) analysis assuming uniform deformation, deformation stress and deformation energy density, and the size-strain plot method. All other relevant physical parameters including stress, strain and energy density have been calculated. The average crystallite size and the lattice strain evaluated from XRD measurements are in good agreement with the results of TEM. Copyright © 2015 Elsevier B.V. All rights reserved.

Molecular structure impacts on secondary organic aerosol formation from glycol ethers

NASA Astrophysics Data System (ADS)

Li, Lijie; Cocker, David R.

2018-05-01

Glycol ethers, a class of widely used solvents in consumer products, are often considered exempt as volatile organic compounds based on their vapor pressure or boiling points by regulatory agencies. However, recent studies found that glycol ethers volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents indicating the potential of glycol ethers to form secondary organic aerosol (SOA). This is the first work on SOA formation from glycol ethers. The impact of molecular structure, specifically -OH, on SOA formation from glycol ethers and related ethers are investigated in the work. Ethers with and without -OH, with methyl group hindrance on -OH and with -OH at different location are studied in the presence of NOX and under "NOX free" conditions. Photooxidation experiments under different oxidation conditions confirm that the processing of ethers is a combination of carbonyl formation, cyclization and fragmentation. Bulk SOA chemical composition analysis and oxidation products identified in both gas and particle phase suggests that the presence and location of -OH in the carbon bond of ethers determine the occurrence of cyclization mechanism during ether oxidation. The cyclization is proposed as a critical SOA formation mechanism to prevent the formation of volatile compounds from fragmentation during the oxidation of ethers. Glycol ethers with -CH2-O-CH2CH2OH structure is found to readily form cyclization products, especially with the presence of NOx, which is more relevant to urban atmospheric conditions than without NOx. Glycol ethers are evaluated as dominating SOA precursors among all ethers studied. It is estimated that the contribution of glycol ethers to anthropogenic SOA is roughly 1% of the current organic aerosol from mobile sources. The contribution of glycol ethers to anthropogenic SOA is roughly 1% of the current organic aerosol from mobile sources and will play a more important role in future anthropogenic SOA formation.

Spawning migration movements of Lost River and shortnose suckers in the Williamson and Sprague Rivers, Oregon, following the removal of Chiloquin Dam-2009 Annual Report

USGS Publications Warehouse

Ellsworth, Craig M.; VanderKooi, Scott P.

2011-01-01

The Chiloquin Dam was located at river kilometer (rkm) 1.3 on the Sprague River near the town of Chiloquin, Oregon. The dam was identified as a barrier that potentially inhibited or prevented the upstream spawning migrations and other movements of endangered Lost River suckers (Deltistes luxatus), shortnose suckers (Chasmistes brevirostris), and other fish in the Sprague River. Our research objectives in 2009 were to evaluate adult catostomid spawning migration patterns using radio telemetry to identify and describe shifts in spawning area distribution and migration behavior following the removal of Chiloquin Dam in 2008. We attached external radio transmitters to 58 Lost River suckers and 59 shortnose suckers captured at the Williamson River fish weir. A total of 17 radio-tagged Lost River suckers and one radio-tagged shortnose sucker were detected approaching the site of the former Chiloquin Dam but only two radio-tagged fish (one male Lost River sucker and one female Lost River sucker) were detected crossing upstream of the dam site. A lower proportion of radio-tagged shortnose suckers were detected migrating into the Sprague River when compared with previous years. Detections on remote passive integrated transponder (PIT) tag arrays located in the Sprague River show that although the proportion of fish coming into the Sprague River is small when compared to the number of fish crossing the Williamson River fish weir, the number of fish migrating upstream of the Chiloquin Dam site increased exponentially in the first year since its removal. These data will be used in conjunction with larval production and adult spawning distribution data to evaluate the effectiveness of dam removal in order to provide increased access to underutilized spawning habitat located further upstream in the Sprague River and to reduce the crowding of spawning fish below the dam site.

Isolation and characterization of an ether-type polyurethane-degrading micro-organism and analysis of degradation mechanism by Alternaria sp.

PubMed

Matsumiya, Y; Murata, N; Tanabe, E; Kubota, K; Kubo, M

2010-06-01

To degrade ether-type polyurethane (ether-PUR), ether-PUR-degrading micro-organism was isolated. Moreover, ether-PUR-degrading mechanisms were analysed using model compounds of ether-PUR. A fungus designated as strain PURDK2, capable of changing the configuration of ether-PUR, has been isolated. This isolated fungus was identified as Alternaria sp. Using a scanning electron microscope, the grid structure of ether-PUR was shown to be melted and disrupted by the fungus. The degradation of ether-PUR by the fungus was analysed, and the ether-PUR was degraded by the fungus by about 27.5%. To analyse the urethane-bond degradation by the fungus, a degraded product of ethylphenylcarbamate was analysed using GC/MS. Aniline and ethanol were detected by degradation with the supernatant, indicating that the fungus secreted urethane-bond-degrading enzyme(s). PURDK2 also degraded urea bonds when diphenylmethane-4,4'-dibutylurea was used as a substrate. The enzyme(s) from PURDK2 degraded urethane and urea bonds to convert the high molecular weight structure of ether-PUR to small molecules; and then the fungus seems to use the small molecules as an energy source. Ether-PUR-degrading fungus, strain PURDK2, was isolated, and the urethane- and urea-bonds-degrading enzymes from strain PURDK2 could contribute to the material recycling of ether-PUR.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Phillips Petroleum Co. is poised to license its high conversion process to produce fuel ethers for blending in reformulated gasolines. The technology has been proven in a Phillips semiworks at Bartlesville, Okla. The process can produce methyl tertiary butyl ether, ethyl tertiary butyl ether, tertiary amyl methyl ether, or tertiary amyl ethyl ether with typical refinery process equipment and techniques. Phillips said it can achieve conversion levels of 92-99%, depending on the ether. The ether produced is determined by which hydrocarbon fraction is used for feedstock and which alcohol is chosen for reaction. The process is described.

Synthesis, Characterization, and Cross-Linking Strategy of a Quercetin-Based Epoxidized Monomer as a Naturally-Derived Replacement for BPA in Epoxy Resins.

PubMed

Kristufek, Samantha L; Yang, Guozhen; Link, Lauren A; Rohde, Brian J; Robertson, Megan L; Wooley, Karen L

2016-08-23

The natural polyphenolic compound quercetin was functionalized and cross-linked to afford a robust epoxy network. Quercetin was selectively methylated and functionalized with glycidyl ether moieties using a microwave-assisted reaction on a gram scale to afford the desired monomer (Q). This quercetin-derived monomer was treated with nadic methyl anhydride (NMA) to obtain a cross-linked network (Q-NMA). The thermal and mechanical properties of this naturally derived network were compared to those of a conventional diglycidyl ether bisphenol A-derived counterpart (DGEBA-NMA). Q-NMA had similar thermal properties [i.e., glass transition (Tg ) and decomposition (Td ) temperatures] and comparable mechanical properties (i.e., Young's Modulus, storage modulus) to that of DGEBA-NMA. However, it had a lower tensile strength and higher flexural modulus at elevated temperatures. The application of naturally derived, sustainable compounds for the replacement of commercially available petrochemical-based epoxies is of great interest to reduce the environmental impact of these materials. Q-NMA is an attractive candidate for the replacement of bisphenol A-based epoxies in various specialty engineering applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sesquiterpene amino ether and cytotoxic phenols from Dendrobium wardianum Warner.

PubMed

Zhang, Cong; Liu, Shou-Jin; Yang, Liu; Yuan, Ming-Yan; Li, Jin-Yu; Hou, Bo; Li, Hong-Mei; Yang, Xing-Zhi; Ding, Chang-Chun; Hu, Jiang-Miao

2017-10-01

A new bibenzyl derivative, dendrocandin V (1) and a new sesquiterpene amino ether, wardianumine A (2), together with eleven known compounds, including phenanthrenes (denbinobin (3), 9,10-dihydro-denbinobin (4), mostatin (5), loddigesiinols A (6)), bibenzyls (moscatilin (7), 5-hydroxy-3,4'-dimethoxybibenzyl (8), 3,4-dihydroxy-5,4'-dimethoxy bibenzyl (9), dendrocandin A (10), gigantol (11), dendrocandin U (12)) and an alkaloids (dihydroshihunine, 13) were isolated from the EtOH extraction of stems of Dendrobium wardianum Warner. Isolation of the new compound 2 indicated that N,N-dimethylethanolamine as the key adduction in the synthesis of dendroxine and its analogs in Dendrobium species. The hypothetical biosynthetic pathway of 2 was then postulated. Inspired by literature and traditional usage of the herbal medicine, some compounds were sent for cytotoxic activity and the results indicated that compounds 1, 3, 4, 5 showed cytotoxic activities against five human cancer cell lines (HL-60, A-549, SMMC-7721, MCF-7, and SW-480) with IC50 from 2.33-38.48μM. Among those compounds, 3 and 4 showed cell line selectivity with strong activity comparable to DDP. Copyright © 2017. Published by Elsevier B.V.

Structure and self-assembly properties of a new chitosan-based amphiphile.

PubMed

Huang, Yuping; Yu, Hailong; Guo, Liang; Huang, Qingrong

2010-06-17

A new chitosan-based amphiphile, octanoyl-chitosan-polyethylene glycol monomethyl ether (acylChitoMPEG), has been prepared using both hydrophobic octanoyl and hydrophilic polyethylene glycol monomethyl ether (MPEG) substitutions. The success of synthesis was confirmed by Fourier transform infrared (FT-IR) and (1)H NMR spectroscopy. The synthesized acylChitoMPEG exhibited good solubility in either aqueous solution or common organic solvents such as ethanol, acetone, and CHCl(3). The self-aggregation behavior of acylChitoMPEG in solutions was studied by a combination of pyrene fluorescence technique, dynamic light scattering, atomic force microscopy, and small-angle X-ray scattering (SAXS). The critical aggregation concentration (CAC) and hydrodynamic diameter were found to be 0.066 mg/mL and 24.4 nm, respectively. SAXS results suggested a coiled structure of the triple helical acylChitoMPEG backbone with the hydrophobic moieties hiding in the center of the backbone, and the hydrophilic MPEG chains surrounding the acylChitoMPEG backbone in a random Gaussian chain conformation. Cytotoxicity results showed that acylChitoMPEG exhibited negligible cytotoxicity even at concentrations as high as 1.0 mg/mL. All results implied that acylChitoMPEG has the potential to be used for biological or medical applications.

Catalytic oxidation of dimethyl ether

DOEpatents

Zelenay, Piotr; Wu, Gang; Johnston, Christina M.; Li, Qing

2016-05-10

A composition for oxidizing dimethyl ether includes an alloy supported on carbon, the alloy being of platinum, ruthenium, and palladium. A process for oxidizing dimethyl ether involves exposing dimethyl ether to a carbon-supported alloy of platinum, ruthenium, and palladium under conditions sufficient to electrochemically oxidize the dimethyl ether.

Palladium-Catalyzed Reductive Insertion of Alcohols into Aryl Ether Bonds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Meng; Gutiérrez, Oliver Y.; Camaioni, Donald M.

Pd/C catalyzes C-O bond cleavage of aryl ethers (diphenyl ether and cyclohexyl phenyl ether) by methanol in H2. The aromatic C-O bond is cleaved by reductive methanolysis, which is initiated by Pd-catalyzed partial hydrogenation of one phenyl ring to form an enol ether. The enol ether reacts rapidly with methanol to form a ketal, which generates methoxycyclohexene by eliminating phenol or an alkanol. Subsequent hydrogenation leads to methoxycyclohexane.

Study Guide: The Principalship from A to Z

ERIC Educational Resources Information Center

Williamson, Ronald; Blackburn, Barbara R.

2010-01-01

Written to accompany the strategies presented in "The Principalship from A-Z," the activities in this book will help you apply the leadership concepts of Blackburn and Williamson to your own experiences as principal. Here, the authors guide you through the process of turning each idea into an actionable plan for your school, allowing you to take…

78 FR 7855 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-04

... Dennis W. Baseman (MN), Kathy L. Brown (IN), Charles K. Eudy (TX), John C. Evans (IL), Thomas J. Ferry (NJ), Jeffrey C. Hanson (TX), Jeffrey D. Kivett (IN), Bryan M. Laffin (MD), Peter W. Prime (MA), David E. Wagner (PA), Daniel V. Williamson (MN), and Charles F. Woodford (WI) from the ITDM requirement in...

Black Women's Faculty Voices in New Mexico: Invisible Assets Silent No More

ERIC Educational Resources Information Center

Woodley, Xeturah Monique

2014-01-01

There continues to exist a lack of Black women faculty at institutions of higher education (Moses, 1989; Collins, 1991; Gregory, 2001). Although we can see an increase in the number of research projects focused on Black women faculty there still remains a significant gap in the research (Glover, 2006; Foster-Williamson, 2002; Thomas &…

21. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, IL Veterans Administration Medical Center. 3/4' SCALE DETAIL - MAIN ENTRANCE UNIT, HALF ELEVATION & SECTION; DRAWING 1-15R, DATED SEPTEMBER 4, 1940. - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

19. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

19. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, IL Veterans Administration Medical Center. DETAILS MAIN STEPS & PLATFORM (SIDE ELEVATION, HALF PLAN, SECTIONS); DRAWING 1-12R, DATED SEPTEMBER 4, 1940. - Veterans Administration Medical Center, Building No. 1, Old State Route 13 West, Marion, Williamson County, IL

4. Photograph of a line drawing in the possession of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Photograph of a line drawing in the possession of the Engineer's Office of the Marion, Illinois Veterans Administration Medical Center. WEST ELEVATION, SOUTH ELEVATION, EAST ELEVATION, NORTH ELEVATION; DRAWING 2-3R, DATED SEPTEMBER 4, 1940. (8 x 10 negative) - Veterans Administration Medical Center, Building No. 2, Old State Route 13 West, Marion, Williamson County, IL

2. View to northeast showing quarters and outbuildings, L to ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. View to northeast showing quarters and outbuildings, L to R: Service Building (HABS No. VA-1287-D), Medical Officer's Quarters C (in background), Garage (HABS No. VA-1287-F), and Medical Officer's Quarters B - Portsmouth Naval Hospital, Medical Officer's Quarters C, West side Williamson Drive, 400 feet South of Rixey Drive, Portsmouth, Portsmouth, VA

Ohio River Environmental Assessment. Cultural Resources Reconnaissance Report, Ohio.

DTIC Science & Technology

1978-01-01

Clermont and Brown Counties, Ohio. Hobart Pub- lishing Company, Milford, Ohio, Vol. 2. !I 47 ,6"_; Clermont County Reichert, Marian R. 1971 Meet Victor...PE 7. OHS, Stivers (1965). 1. 417.5 2. Williamson- Baird House/Crabbe House 3. 1825 and 1863 4. 695’ 5. 510’ 6. PE 7. OHS, Stivers (1965), Zachman (1975

Exploration of Healthy Eating Education and Consumption of Various Foods of College Students in a Small Liberal Arts College

ERIC Educational Resources Information Center

Miller, Patricia Bederman; Anthony, Dorothy; Yarrish, Karen K.

2013-01-01

Overweight and obesity are major risk factors for a number of chronic diseases, including diabetes, cardiovascular diseases and cancer (World Health Organization, 2011; National Institutes of Health, 1998). Children with high BMI often become obese adults (Serdula, Ivery, Coates, Freedman, Williamson, & Byers, 1993). According to the World…

Hydrides and Borohydrides of Light Elements

DTIC Science & Technology

1947-12-04

Troy, Attn: Inst. of Naval Science (30) Solar Aircraft Cu,, San Diego, Attn: Dr. M. A. Williamson " (31) INSMAT. N. J. for Itandard Oil Co., Esso Lab...with the other# iLD F.Re p. 8 ilt -ms" #61ggSotod that.. ir addition to thc impurity in the t~y..thr, an impurkty, prosumably aluminum hydride, in

Why Should We Have All the Fun? Encouraging Colleagues to Read YA Novels across the Curriculum

ERIC Educational Resources Information Center

Roberts, Mike

2012-01-01

Recently, the National Council of Teachers of English (NCTE) helped create the National Center for Literacy Education (NCLE) to help support literacy across all disciplines. NCLE Director Kent Williamson notes, "Schools that sustain progress in literacy learning pay attention to the little things and the big things. They create organizational…

Zero to Three: Bulletin of the National Center for Clinical Infant Programs. Volume IX, Nos. 1-5, September, 1988-June, 1989.

ERIC Educational Resources Information Center

Zero to Three, 1989

1989-01-01

Five bulletins of the National Center for Clinical Infant Programs provide articles with the following titles and authors: "Motor Control as a Resource for Adaptive Coping" (G. Gordon Williamson et al.); "Fostering Emotional and Social Development in Infants with Disabilities" (Stanley Greenspan); "Dramatic Responses in a…

RATE CONSTANTS FOR THE REACTIONS OF OH RADICALS AND CL ATOMS WITH DI-N-PROPYL ETHER AND DI-N-BUTYL ETHER AND THEIR DEUTERATED ANALOGS. (R825252)

EPA Science Inventory

Using relative rate methods, rate constants for the gas-phase reactions of OH radicals and Cl atoms with di-n-propyl ether, di-n-propyl ether-d₁₄, di-n-butyl ether and di-n-butyl ether-d₁₈ have been measured at 296 ? 2 K and atmos...

Synthesis, X-ray crystallography, and computational analysis of 1-azafenestranes.

PubMed

Denmark, Scott E; Montgomery, Justin I; Kramps, Laurenz A

2006-09-06

The tandem [4+2]/[3+2] cycloaddition of nitroalkenes has been employed in the synthesis of 1-azafenestranes, molecules of theoretical interest because of planarizing distortion of their central carbon atoms. The synthesis of c,c,c,c-[5.5.5.5]-1-azafenestrane was completed in good yield from a substituted nitrocyclopentene, and its borane adduct was analyzed through X-ray crystallography, which showed a moderate distortion from ideal tetrahedral geometry. The syntheses of two members of the [4.5.5.5] family of 1-azafenestranes are also reported, including one with a trans fusion at a bicyclic ring junction which brings about considerable planarization of one of the central angles (16.8 degrees deviation from tetrahedral geometry). While investigating the [4.5.5.5]-1-azafenestranes, a novel dyotropic rearrangement that converts nitroso acetals into tetracyclic aminals was discovered. Through conformational analysis, a means to prevent this molecular reorganization was formulated and realized experimentally with the use of a bulky vinyl ether in the key [4+2] cycloaddition reaction. Finally, DFT calculations on relative strain energy for the 1-azafenestranes, as well as their predicted central angles, are disclosed.

NIOSH Manual of Analytical Methods (third edition). Fourth supplement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-08-15

The NIOSH Manual of Analytical Methods, 3rd edition, was updated for the following chemicals: allyl-glycidyl-ether, 2-aminopyridine, aspartame, bromine, chlorine, n-butylamine, n-butyl-glycidyl-ether, carbon-dioxide, carbon-monoxide, chlorinated-camphene, chloroacetaldehyde, p-chlorophenol, crotonaldehyde, 1,1-dimethylhydrazine, dinitro-o-cresol, ethyl-acetate, ethyl-formate, ethylenimine, sodium-fluoride, hydrogen-fluoride, cryolite, sodium-hexafluoroaluminate, formic-acid, hexachlorobutadiene, hydrogen-cyanide, hydrogen-sulfide, isopropyl-acetate, isopropyl-ether, isopropyl-glycidyl-ether, lead, lead-oxide, maleic-anhydride, methyl-acetate, methyl-acrylate, methyl-tert-butyl ether, methyl-cellosolve-acetate, methylcyclohexanol, 4,4'-methylenedianiline, monomethylaniline, monomethylhydrazine, nitric-oxide, p-nitroaniline, phenyl-ether, phenyl-ether-biphenyl mixture, phenyl-glycidyl-ether, phenylhydrazine, phosphine, ronnel, sulfuryl-fluoride, talc, tributyl-phosphate, 1,1,2-trichloro-1,2,2-trifluoroethane, trimellitic-anhydride, triorthocresyl-phosphate, triphenyl-phosphate, and vinyl-acetate.

Synthesis and biological evaluation of pyrrolidine derivatives as novel and potent sodium channel blockers for the treatment of ischemic stroke.

PubMed

Seki, Maki; Tsuruta, Osamu; Tatsumi, Ryo; Soejima, Aki

2013-07-15

A novel series of pyrrolidine derivatives as Na(+) channel blockers was synthesized and evaluated for their inhibitory effects on neuronal Na(+) channels. Structure-activity relationship (SAR) studies of a pyrrolidine analogue 2 led to the discovery of 5e as a potent Na(+) channel blocker with a low inhibitory action against human ether-a-go-go-related gene (hERG) channels. Compound 5e showed remarkably neuroprotective activity in a rat transient middle cerebral artery occlusion (MCAO) model, suggesting that 5e would act as a neuroprotectant for ischemic stroke. Copyright © 2013 Elsevier Ltd. All rights reserved.

A new readily processable polyimide

NASA Technical Reports Server (NTRS)

Harris, F. W.; Beltz, M. W.; Hergenrother, P. M.

1986-01-01

As part of an effort to develop tough solvent resistance thermoplastics for potential use as structural resins on aerospace vehicles, a new processable polyimide was evaluated. The synthesis involved the reaction of a new diamine, 1,3-bis 2-(3-aminophenoxy)ethyl ether, with 3,3',4,4'-benzophenonetetracarboxylic dianhydride to form the polyamic acid and subsequent conversion of it to the polyimide. Various physical properties such as thermal stability, solvent resistance, glass transition temperature, crystalline melt temperature, melt viscosity and mechanical properties such as fracture toughness, adhesive, film and composite properties are reported. Of particular interest is the extremely high titanium to titanium tensile shear strength obtained for this polyimide.

Hybrid Fluorosilicones for Aircraft Fuel Tank Sealants. Part 4. Synthesis of Fluorocarbon and Fluorocarbon Ether Hybrid Fluorosilicone Polymers.

DTIC Science & Technology

1974-05-01

onine n oviro id i ncesay (Coidntiu d onac evesesie fluoroether SECURITY CLASIICAIO OFstuei THISer wAGE sythsie,and uRred) research~~~~~~~~ amle wer...i I. ." r;. . - 7 7 7 SECTION Table of Contents (Continued)Page b. Preparation of CHa-CH(CFa)aO(CFa),O( CFt )CH-CH* ............ 27 c. Preparation of...Photolysis of I(CFg)aO(CPs)nO(CFm)aI/Hg/ CFt .................. 32 6. Reaction of I(CFR)&O(CF,).O(CFa)s1 with Hg ..................... 33 a. 280 0C

Viscosity of aqueous solutions of n-methyldiethanolamine and of diethanolamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teng, T.T.; Maham, Y.; Hepler, L.G.

1994-04-01

Aqueous solutions of alkanolamines such as monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), di-2-propanolamine (DIPA), and bis[2-(hydroxyamino)ethyl] ether (DGA) are good solvents for the removal of acid gases such as CO[sub 2] and H[sub 2]S from the gas streams of many processes in the natural gas, petroleum, ammonia synthesis, and some chemical industries. The viscosity of aqueous solutions of methyldiethanolamine (MDEA) and of diethanolamine (DEA) have been measured at five temperatures in the range 25--80 C throughout the whole concentration range. The viscosity has been correlated as a function of composition for use in industrial calculations.

Radionuclide-binding compound, a radionuclide delivery system, a method of making a radium complexing compound, a method of extracting a radionuclide, and a method of delivering a radionuclide

DOEpatents

Fisher, Darrell R.; Wai, Chien M.; Chen, Xiaoyuan

2000-01-01

The invention pertains to compounds which specifically bind radionuclides, and to methods of making radionuclide complexing compounds. In one aspect, the invention includes a radionuclide delivery system comprising: a) a calix[n]arene-crown-[m]-ether compound, wherein n is an integer greater than 3, and wherein m is an integer greater than 3, the calix[n]arene-crown-[m]-ether compound comprising at least two ionizable groups; and b) an antibody attached to the calix[n]arene-crown-[m]-ether compound. In another aspect, the invention includes a method of making a radium complexing compound, comprising: a) providing a calix[n]arene compound, wherein n is an integer greater than 3, the calix[n]arene compound comprising n phenolic hydroxyl groups; b) providing a crown ether precursor, the crown ether precursor comprising a pair of tosylated ends; c) reacting the pair of tosylated ends with a pair of the phenolic hydroxyl groups to convert said pair of phenolic hydroxyl groups to ether linkages, the ether linkages connecting the crown ether precursor to the calix[n]arene to form a calix[n]arene-crown-[m]-ether compound, wherein m is an integer greater than 3; d) converting remaining phenolic hydroxyl groups to esters; e) converting the esters to acids, the acids being proximate a crown-[m]-ether portion of the calix[n]arene-crown-[m]-ether compound; and f) providing a Ra.sup.2+ ion within the crown-[m]-ether portion of the calix[n]arene-crown-[m]-ether compound.

Vapor intrusion risk of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME) and ethyl tert-butyl ether (ETBE): A modeling study.

PubMed

Ma, Jie; Xiong, Desen; Li, Haiyan; Ding, Yi; Xia, Xiangcheng; Yang, Yongqi

2017-06-15

Vapor intrusion of synthetic fuel additives represents a critical yet still neglected problem at sites contaminated by petroleum fuel releases. This study used an advanced numerical model to investigate the vapor intrusion potential of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), and ethyl tert-butyl ether (ETBE). Simulated indoor air concentration of these compounds can exceed USEPA indoor air screening level for MTBE (110μg/m 3 ). Our results also reveal that MTBE has much higher chance to cause vapor intrusion problems than TAME and ETBE. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the vertical screening criteria for petroleum hydrocarbons may not provide sufficient protectiveness for fuel additives, and ether oxygenates in particular. In addition to adverse impacts on human health, ether oxygenate vapor intrusion may also cause aesthetic problems (i.e., odour and flavour). Overall, this study points out that ether oxygenates can cause vapor intrusion problems. We recommend that USEPA consider including the field measurement data of synthetic fuel additives in the existing PVI database and possibly revising the PVI Guidance as necessary. Copyright © 2017 Elsevier B.V. All rights reserved.

Carbon Conversion Efficiency and Limits of Productive Bacterial Degradation of Methyl tert-Butyl Ether and Related Compounds▿

PubMed Central

Müller, Roland H.; Rohwerder, Thore; Harms, Hauke

2007-01-01

The utilization of the fuel oxygenate methyl tert-butyl ether (MTBE) and related compounds by microorganisms was investigated in a mainly theoretical study based on the YATP concept. Experiments were conducted to derive realistic maintenance coefficients and Ks values needed to calculate substrate fluxes available for biomass production. Aerobic substrate conversion and biomass synthesis were calculated for different putative pathways. The results suggest that MTBE is an effective heterotrophic substrate that can sustain growth yields of up to 0.87 g g−1, which contradicts previous calculation results (N. Fortin et al., Environ. Microbiol. 3:407-416, 2001). Sufficient energy equivalents were generated in several of the potential assimilatory routes to incorporate carbon into biomass without the necessity to dissimilate additional substrate, efficient energy transduction provided. However, when a growth-related kinetic model was included, the limits of productive degradation became obvious. Depending on the maintenance coefficient ms and its associated biomass decay term b, growth-associated carbon conversion became strongly dependent on substrate fluxes. Due to slow degradation kinetics, the calculations predicted relatively high threshold concentrations, Smin, below which growth would not further be supported. Smin strongly depended on the maximum growth rate μmax, and b and was directly correlated with the half maximum rate-associated substrate concentration Ks, meaning that any effect impacting this parameter would also change Smin. The primary metabolic step, catalyzing the cleavage of the ether bond in MTBE, is likely to control the substrate flux in various strains. In addition, deficits in oxygen as an external factor and in reduction equivalents as a cellular variable in this reaction should further increase Ks and Smin for MTBE. PMID:17220260

Caco-2 Permeability Studies and In Vitro hERG Liability Assessment of Tryptanthrin and Indolinone.

PubMed

Jähne, Evelyn A; Eigenmann, Daniela E; Moradi-Afrapoli, Fahimeh; Verjee, Sheela; Butterweck, Veronika; Hebeisen, Simon; Hettich, Timm; Schlotterbeck, Götz; Smieško, Martin; Hamburger, Matthias; Oufir, Mouhssin

2016-08-01

Tryptanthrin and (E,Z)-3-(4-hydroxy-3,5-dimethoxybenzylidene)indolinone (indolinone) were recently isolated from Isatis tinctoria as potent anti-inflammatory and antiallergic alkaloids, and shown to inhibit COX-2, 5-LOX catalyzed leukotriene synthesis, and mast cell degranulation at low µM to nM concentrations. To assess their suitability for oral administration, we screened the compounds in an in vitro intestinal permeability assay using human colonic adenocarcinoma cells. For exact quantification of the compounds, validated UPLC-MS/MS methods were used. Tryptanthrin displayed high permeability (apparent permeability coefficient > 32.0 × 10(-6) cm/s) across the cell monolayer. The efflux ratio below 2 (< 1.12) and unchanged apparent permeability coefficient values in the presence of the P-glycoprotein inhibitor verapamil (50 µM) indicated that tryptanthrin was not involved in P-glycoprotein interactions. For indolinone, a low recovery was found in the human colon adenocarcinoma cell assay. High-resolution mass spectrometry pointed to extensive phase II metabolism of indolinone (sulfation and glucuronidation). Possible cardiotoxic liability of the compounds was assessed in vitro by measurement of an inhibitory effect on human ether-a-go-go-related gene tail currents in stably transfected HEK 293 cells using the patch clamp technique. Low human ether-a-go-go-related gene inhibition was found for tryptanthrin (IC50 > 10 µM) and indolinone (IC50 of 24.96 µM). The analysis of compounds using various in silico methods confirmed favorable pharmacokinetic properties, as well as a slight inhibition of the human ether-a-go-go-related gene potassium channel at micromolar concentrations. Georg Thieme Verlag KG Stuttgart · New York.

Boundary lubrication, thermal and oxidative stability of a fluorinated polyether and a perfluoropolyether triazine

NASA Technical Reports Server (NTRS)

Jones, W. R., Jr.; Snyder, C. E., Jr.

1979-01-01

Boundary lubricating characteristics, thermal stability, and oxidation-corrosion stability were determined for a fluorinated polyether and a perfluoropolyether triazine. A ball-on-disk apparatus, a tensimeter, and oxidation-corrosion apparatus were used. Results were compared to data for a polyphenyl ether and a C-ether. The polyether and triazine yielded better boundary lubricating characteristics than either the polyphenyl ether or C-ether. The polyphenyl ether had the greatest thermal stability (443 C) while the other fluids had stabilities in the range 389 to 397 C. Oxidation-corrosion results indicated the following order of stabilities: perfluoropolyether trizine greater than polyphenyl ether greater than C-ether greater than fluorinated polyether.

Sinterable Ceramic Powders from Laser-Heated Gases.

DTIC Science & Technology

1988-02-01

ether . carboxylic acid. and aldehyde clases: water is also included.Acrigto William and Goodman.’ a single crystalline sili- The single-crstalline...represent commonly available organic families, Including aliphatic and aromatic hydrocarbons, chlorides, ethers , ketones , esters, alcohols, aldehydes...Hydrocarbons Ketone Amine Chlorides Low-alcohols 8f . Ether Ester - _Aldehyde Ether Ketones High-alcohols 04 Carboxylic Ester I acid Ether o . Nitrile

Synthetic studies on schisandra nortriterpenoids. Stereocontrolled synthesis of enantiopure C-5-epi ABC ring systems of micrandilactone A and lancifodilactone G using RCM.

PubMed

Maity, Soumitra; Matcha, Kiran; Ghosh, Subrata

2010-06-18

A stereocontrolled approach for the construction of ABC ring systems of micrandilactone A and lancifodilactone G has been developed. The synthesis involves construction of an enantiopure functionalized cycloheptene derivative 17 through RCM of the dienol 14 prepared from the known D-mannitol-derived unsaturated ester 12. A remarkable regioselectivity during hydroboration of the cycloheptene derivative 17 was observed during its transformation to the cycloheptanone 20. RCM of the diene 24 prepared stereoselectively from 20 gave the spiro-dihydrofuran 25. The ketal unit in 25 was then converted into the carbinols 28 and 36. A bromonium ion initiated highly stereocontrolled intramolecular etherification in 28 and 37 led to the tricyclic ethers 29 and 38, respectively. Reductive removal of bromine from 29 and 38 followed by RuO(4) oxidation led to the furo-furanone derivatives 31 and 40, the C-5-epi ABC ring systems of the schisandra nortriterpenoids 1 and 2.

Synthesis and characterization of tetra phenoxy-substituted halogen-rich metallophthalocyanine derivatives: A study on their LCD color filter requirements

NASA Astrophysics Data System (ADS)

Muthukumar, Palanisamy; Kim, Hak-Soo; Jeong, Jong Woo; Son, Young-A.

2016-09-01

This study addresses the synthesis and characterization of new tetra phenoxy-substituted halogen-rich metallophthalocyanine derivatives (MPcs) 4-7 (M = Co, Ni, Cu and Zn). The synthesized new compounds were characterized using UV-Vis, FT-IR, MALDI-TOF, 1H NMR and elemental analyses. In addition, the basic requirements such as aggregation behavior, thermal stability, transmittance and solubility in propylene glycol monomethyl ether acetate (PGMEA) of MPcs 4-7 were investigated for their usage as a green color filter in Liquid Crystal Displays (LCDs). All of the MPcs showed thermal stability and sufficient solubility in PGMEA. However, the addition of binder into PGMEA solution of MPcs 5 and 6 leads to precipitation. Among the four MPcs, zinc phthalocyanine (7) showed higher transmittance. The higher transmittance of zinc phthalocyanine (7) along with its thermal stability and sufficient solubility in PGMEA are promising for its application as a green color filter in LCDs.

Divergent synthesis of bioactive resorcinols isolated from the fruiting bodies of Hericium erinaceum: total syntheses of hericenones A, B, and I, hericenols B-D, and erinacerins A and B.

PubMed

Kobayashi, Shoji; Tamanoi, Hidetsugu; Hasegawa, Yuichi; Segawa, Yusuke; Masuyama, Araki

2014-06-06

Total syntheses of 5'- and 7'-oxidized geranyl resorcylates isolated from the fruiting bodies of Hericium erinaceum and the submerged cultures of a Stereum species were achieved. Our synthesis features derivatization of a suitably functionalized 5'-oxidized geranyl phthalide as a common intermediate, which was obtained by Stille coupling between the phthalide core and the side chain, into a series of natural products by divergent functional group manipulations. The crucial C5'-oxygen functionality was installed at the initial stage by alkylation by an α-cyano ethoxyethyl ether. From a common synthetic intermediate, eight total syntheses including hericenones A, B, and I, hericenols B-D, and erinacerins A and B were achieved (hericenol B and erinacerin B were synthesized as racemates). The structure of hericenone B established in the isolation paper was unambiguously revised as the carbonyl regioisomer at the lactam moiety.

Mechanism of Particle Formation in Silver/Epoxy Nanocomposites Obtained through a Visible-Light-Assisted in Situ Synthesis.

PubMed

dell'Erba, Ignacio E; Martínez, Francisco D; Hoppe, Cristina E; Eliçabe, Guillermo E; Ceolín, Marcelo; Zucchi, Ileana A; Schroeder, Walter F

2017-10-03

A detailed understanding of the processes taking place during the in situ synthesis of metal/polymer nanocomposites is crucial to manipulate the shape and size of nanoparticles (NPs) with a high level of control. In this paper, we report an in-depth time-resolved analysis of the particle formation process in silver/epoxy nanocomposites obtained through a visible-light-assisted in situ synthesis. The selected epoxy monomer was based on diglycidyl ether of bisphenol A, which undergoes relatively slow cationic ring-opening polymerization. This feature allowed us to access a full description of the formation process of silver NPs before this was arrested by the curing of the epoxy matrix. In situ time-resolved small-angle X-ray scattering investigation was carried out to follow the evolution of the number and size of the silver NPs as a function of irradiation time, whereas rheological experiments combined with near-infrared and ultraviolet-visible spectroscopies were performed to interpret how changes in the rheological properties of the matrix affect the nucleation and growth of particles. The analysis of the obtained results allowed us to propose consistent mechanisms for the formation of metal/polymer nanocomposites obtained by light-assisted one-pot synthesis. Finally, the effect of a thermal postcuring treatment of the epoxy matrix on the particle size in the nanocomposite was investigated.

Influence of reaction medium during synthesis of Gantrez AN 119 nanoparticles for oral vaccination.

PubMed

Vandamme, Katrien; Melkebeek, Vesna; Cox, Eric; Deforce, Dieter; Lenoir, Joke; Adriaens, Els; Vervaet, Chris; Remon, Jean Paul

2010-02-01

Two synthesis methods of poly(methyl vinyl ether-co-maleic anhydride) (Gantrez AN 119) nanoparticles (NP) (used for oral vaccination) were compared. Wheat germ agglutinin (WGA) was used as ligand to enhance the bioadhesive properties of NP and beta-galactosidase as antigen. The first method encapsulated beta-galactosidase in NP by co-precipitation in an acetone/water mixture containing 44% acetone. In the second method, antigen addition occurred in 100% acetone. To improve stability, NP were crosslinked with 1,3-diaminopropane. The stability of WGA-conjugated NP with encapsulated antigen diminished at lower pH and when decreasing the amount of crosslinker. The binding type between WGA and polymer depended on the synthesis method: predominantly ionic bonds were formed using the 44% acetone method, whereas synthesis via the 100% acetone method resulted in covalent bonds. The biological activity of the WGA coating, evaluated via a pig gastric mucin binding test, was lower in NP prepared via the 100% acetone method. No release of native antigen was detected after hydrolysis of NP, due to the covalent antigen binding during antigen encapsulation and the high reactivity of the polymer. Moreover, the mucosal irritation capacity was evaluated upon nanoparticle hydrolysis using a slug mucosal irritation assay. Herein, hydrolysed NP of the 44% acetone method were classified as mild irritative. Copyright (c) 2009 Elsevier B.V. All rights reserved.

77 FR 40897 - Notice of Intent to Repatriate Cultural Items: Gregg County Historical Museum, Longview, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-11

... and thereafter, six unassociated funerary objects were removed from burials at the C.D. Marsh site... piece of sheet brass, and 1 brass musket butt plate. The Millsey Williamson site dates to A.D. 1650-1800..., the Late-Historic Caddo period. Sometime between the mid-1950s and the mid-1960s, six unassociated...

Relational Contract: Applicable to Department of Defense Contracts

DTIC Science & Technology

1989-12-01

examine the evolution of contract law and, in particular, the role of contractual incompleteness in exchange relationships. 2.1.1. The Classical Approach...Classical contract law facilitates exchange by separately detailing all aspects of the contracting process 9 at the outset by prespecification of all...modifications after contractual performance has begun. According to Williamson (1979), classical contract law implements prespecification through legal

The Future of the Curriculum: School Knowledge in the Digital Age. MacArthur Foundation Reports on Digital Media and Learning

ERIC Educational Resources Information Center

Williamson, Ben

2013-01-01

Although ideas about digital media and learning have become an important area for educational research, little attention has been given to the practical and conceptual implications for the school curriculum. In this book, Ben Williamson examines a series of contemporary curriculum innovations in the United States, Great Britain, and Australia that…

7. View to northwest showing (from L to R) ends ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. View to northwest showing (from L to R) ends of 1941 NW wing, original NW ward wing, and original SE ward wing, with ends of Medical Wards C and B (HABS Nos. VA-1287-I and -H) at left - Portsmouth Naval Hospital, Hospital Building, Rixey Place, bounded by Williamson Drive, Holcomb Road, & The Circle, Portsmouth, Portsmouth, VA

The Search for Suitable Strategy: Threat-Based and Capabilities-Based Strategies in a Complex World

DTIC Science & Technology

2016-05-26

subject to copyright, however further publication or sale of copyrighted images is not permissible. ii...Williamson Murray and Richard Hart Sinnreich, eds., Successful Strategies: Triumphing in War and Peace from Antiquity to the Present (Cambridge, United...Sinnreich, eds. Successful Strategies: Triumphing in War and Peace from Antiquity to the Present. Cambridge, United Kingdom: Cambridge University Press

Flow and heat transfer in water based liquid film fluids dispensed with graphene nanoparticles

NASA Astrophysics Data System (ADS)

Zuhra, Samina; Khan, Noor Saeed; Khan, Muhammad Altaf; Islam, Saeed; Khan, Waris; Bonyah, Ebenezer

2018-03-01

The unsteady flow and heat transfer characteristics of electrically conducting water based thin liquid film non-Newtonian (Casson and Williamson) nanofluids dispensed with graphene nanoparticles past a stretching sheet are considered in the presence of transverse magnetic field and non-uniform heat source/sink. Embedding the graphene nanoparticles effectively amplifies the thermal conductivity of Casson and Williamson nanofluids. Ordinary differential equations together with the boundary conditions are obtained through similarity variables from the governing equations of the problem, which are solved by the HAM (Homotopy Analysis Method). The solution is expressed through graphs and illustrated which show the influences of all the parameters. The convergence of the HAM solution for the linear operators is obtained. Favorable comparison with previously published research paper is performed to show the correlation for the present work. Skin friction coefficient and Nusselt number are presented through Tables and graphs which show the validation for the achieved results demonstrating that the thin liquid films results from this study are in close agreement with the results reported in the literature. Results achieved by HAM and residual errors are evaluated numerically, given in Tables and also depicted graphically which show the accuracy of the present work.

Simulation and validation of larval sucker dispersal and retention through the restored Williamson River Delta and Upper Klamath Lake system, Oregon

USGS Publications Warehouse

Wood, Tamara M.; Hendrixson, Heather A.; Markle, Douglas F.; Erdman, Charles S.; Burdick, Summer M.; Ellsworth, Craig M.

2014-01-01

A hydrodynamic model with particle tracking was used to create individual-based simulations to describe larval fish dispersal through the restored Williamson River Delta and into Upper Klamath Lake, Oregon. The model was verified by converting particle ages to larval lengths and comparing these lengths to lengths of larvae in net catches. Correlations of simulated lengths with field data were moderate and suggested a species-specific difference in model performance. Particle trajectories through the delta were affected by wind speed and direction, lake elevation, and shoreline configuration. Once particles entered the lake, transport was a function of current speed and whether behavior enhanced transport (swimming aligned with currents) or countered transport through greater dispersal (faster random swimming). We tested sensitivity to swim speed (higher speeds led to greater dispersal and more retention), shoreline configuration (restoration increased retention relative to pre-restoration conditions), and lake elevation (retention was maximized at an intermediate elevation). The simulations also highlight additional biological questions, such as the extent to which spatially heterogeneous mortality or fish behavior and environmental cues could interact with wind-driven currents and contribute to patterns of dispersal.

Green synthesis and characterization of Ag nanoparticles from Mangifera indica leaves for dental restoration and antibacterial applications.

PubMed

Sundeep, Dola; Vijaya Kumar, T; Rao, P S Subba; Ravikumar, R V S S N; Gopala Krishna, A

2017-05-01

Green synthesis has gained a wide recognition as clean synthesis technique in the recent years. In the present investigation, silver nanoparticles were prepared by a novel green synthesis technique using Mangifera indica (Mango leaves) and found to be successfully used in dental applications. The prepared samples were spectroscopically characterized by XRD, PSA, SEM with EDS, and UV-Vis spectroscopy. The crystalline size and lattice strain were analyzed from the XRD data which were counter-verified by W-H plots and particle size analyzer. The XRD peaks revealed that average crystalline size of the as-synthesized Ag nanoparticles was of 32.4 nm with face-centered cubic structure. This was counter-verified by particle size analyzer and Williamson-Hall plots and found to be 31.7 and 33.21 nm in the former and latter, and the crystalline size of Ag NPs could be concluded as 32 ± 2 nm. The morphological structure of the prepared sample was studied through SEM images and the chemical composition was analyzed by the EDS data. The band energy was calculated as 393 nm from UV-Vis, which confirmed the synthesized sample as Ag nanoparticles. To improve the mechanical bonding and hardness of the dentally used glass ionomer cement (GIC), the synthesized silver nanoparticles were incorporated into GIC in 2% weight ratio. The morphology of the prepared specimens was studied using optical microscope images. Vickers microhardness and Monsanto hardness tests were performed on GIC, GIC reinforced with microsilver particles and GIC reinforced with nanosilver particles and the latter derived a promising results. The results of the Monsanto tests confirmed the increase in hardness of the GIC reinforced with AgNps as 14.2 kg/cm 2 compared to conventional GIC and GIC reinforced with silver microparticle as 11.7 and 9.5 kg/cm 2 . Similarly the Vickers hardness results exhibited the enhanced hardness of GIC-reinforced AgNps as 82 VHN compared to GIC as 54 and GIC-reinforced silver microparticles as 61 VHN. The antibacterial activity of AgNPs was tested by a well-diffusion method on Escherichia coli and Staphylococcus aureus bacteria, and the obtained results exhibited a promising antibacterial activity of the as-synthesized nanoparticles.

Biodegradation of bis(1-chloro-2-propyl) ether via initial ether scission and subsequent dehalogenation by Rhodococcus sp. strain DTB.

PubMed

Moreno Horn, Marcus; Garbe, Leif-Alexander; Tressl, Roland; Adrian, Lorenz; Görisch, Helmut

2003-04-01

Rhodococcus sp. strain DTB (DSM 44534) grows on bis(1-chloro-2-propyl) ether (DDE) as sole source of carbon and energy. The non-chlorinated diisopropyl ether and bis(1-hydroxy-2-propyl) ether, however, did not serve as substrates. In ether degradation experiments with dense cell suspensions, 1-chloro-2-propanol and chloroacetone were formed, which indicated that scission of the ether bond is the first step while dehalogenation of the chlorinated C(3)-compounds occurs at a later stage of the degradation pathway. Inhibition of ether scission by methimazole suggested that the first step in degradation is catalyzed by a flavin-dependent enzyme activity. The non-chlorinated compounds 1,2-propanediol, hydroxyacetone, lactate, pyruvate, 1-propanol, propanal, and propionate also supported growth, which suggested that the intermediates 1,2-propanediol and hydroxyacetone are converted to pyruvate or to propionate, which can be channeled into the citric acid cycle by a number of routes. Total release of chloride and growth-yield experiments with DDE and non-chlorinated C(3)-compounds suggested complete biodegradation of the chlorinated ether.

Some actions of substituted choline phenyl ethers, particularly of choline 2:6-xylyl ether

PubMed Central

Edge, N. D.; Mason, D. F. J.; Wyllie, J. H.

1957-01-01

Marked nicotine-like stimulant properties are possessed by choline phenyl ether and choline o-tolyl ether, and to a decreasing extent by choline 2:6-xylyl ether and choline 2:4:6-mesityl ether. The compounds all show neuromuscular blocking properties, which are of short duration and pass from mainly decamethonium-like to mainly curare-like as more methyl groups are added to the phenyl nucleus. This series of compounds also possesses muscarinic, weak anti-adrenaline and vasodilator properties, as well as long-lasting local anaesthetic effects in the two compounds tested by intradermal injection. PMID:13460236

The effect of glucocorticoids on sex steroid synthesis in cultured Taenia crassiceps Wake Forest University (WFU) cysticerci.

PubMed

Hinojosa, L; Valdez, R A; Salvador, V; Rodríguez, A G; Willms, K; Romano, M C

2012-12-01

We have shown previously that cultured Taenia crassiceps Wake Forest University (WFU) and Taenia solium cysticerci, as well as the adult worms, synthesize sex steroid hormones from [3H]steroid precursors and that androgens and oestrogens influence the in vitro development of the parasites. Glucocorticoids (GCs) are used to control the inflammation caused by T. solium cysticerci in the brain. These steroids stimulate oestrogen synthesis in several tissues. Since there is no information on the effect of GC on the endocrine function of cysticerci, we investigated the effect of natural and synthetic GCs on the synthesis of oestrogens in cultured T. crassiceps WFU cysticerci. The cysticerci were obtained from the peritoneal cavity of infected female BALB/c mice; the cysts were washed extensively and pre-cultured in Dulbecco's Modified Eagle's Medium (DMEM) plus antibiotics for 5 days. The parasites were further cultured with different doses of corticosterone, dexamethasone or the vehicle for 5 days. [3H]Dehydroepiandrosterone (3H-DHEA) was added to the media and the cysticerci were further incubated for 6 or 24 h. Media were then removed and the steroids ether-extracted. Aliquots of the media were seeded on silica gel plates and developed in solvent systems. Parasites incubated in the presence of 3H-DHEA synthesized [3H]androstenediol, [3H]testosterone and [3H]17β-oestradiol ([3H]17β-E2). The addition of 100 nm or higher corticosterone doses to the media increased [3H]17β-E2 synthesis fourfold after 24 h. Dexamethasone also increased [3H]17β-E2 synthesis. The experiments presented here show for the first time that corticosterone and the synthetic GC dexamethasone modulate the synthesis of oestrogens by cysticerci.

Single chain technology: Toward the controlled synthesis of polymer nanostructures

NASA Astrophysics Data System (ADS)

Lyon, Christopher

A technique for fabricating advanced polymer nanostructures enjoying recent popularity is the collapse or folding of single polymer chains in highly dilute solution mediated by intramolecular cross-linking. We term the resultant structures single-chain nanoparticles (SCNP). This technique has proven particularly valuable in the synthesis of nanomaterials on the order of 5 -- 20 nm. Many different types of covalent and non-covalent chemistries have been used to this end. This dissertation investigates the use of so-called single-chain technology to synthesize nanoparticles using modular techniques that allow for easy incorporation of functionality or special structural or characteristic features. Specifically, the synthesis of linear polymers functionalized with pendant monomer units and the subsequent intramolecular polymerization of these monomer units is discussed. In chapter 2, the synthesis of SCNP using alternating radical polymerization is described. Polymers functionalized with pendant styrene and stilbene groups are synthesized via a modular post-polymerization Wittig reaction. These polymers were exposed to radical initiators in the presence (and absence) of maleic anhydride and other electron deficient monomers in order to form intramolecular cross-links. Chapter 3 discusses templated acyclic diene metathesis (ADMET) polymerization using single-chain technology, starting with the controlled ring-opening polymerization of a glycidyl ether functionalized with an ADMET monomer. This polymer was then exposed to Grubbs' catalyst to polymerize the ADMET monomer units. The ADMET polymer was hydrolytically cleaved from the template and separated. Upon characterization, it was found that the daughter ADMET polymer had a similar degree of polymerization, but did not retain the low dispersity of the template. Chapter 4 details the synthesis of aldehyde- and diol-functionalized polymers toward the synthesis of SCNP containing dynamic, acid-degradable acetal cross-links. SCNP fabrication with these materials is beyond the scope of this dissertation.

Studies of flerovium and element 115 homologs with macrocyclic extractants

NASA Astrophysics Data System (ADS)

Despotopulos, John Dustin

Study of the chemistry of the heaviest elements, Z ? 104, poses a unique challenge due to their low production cross-sections and short half-lives. Chemistry also must be studied on the one-atom-at-a-time scale, requiring automated, fast, and very efficient chemical schemes. Recent studies of the chemical behavior of copernicium (Cn, element 112) and flerovium (Fl, element 114) together with the discovery of isotopes of these elements with half-lives suitable for chemical studies have spurred a renewed interest in the development of rapid systems designed to study the chemical properties of elements with Z ≥ 114. This dissertation explores both extraction chromatography and solvent extraction as methods for development of a rapid chemical separation scheme for the homologs of flerovium (Pb, Sn, Hg) and element 115 (Bi, Sb), with the goal of developing a chemical scheme that, in the future, can be applied to on-line chemistry of both Fl and element 115. Macrocyclic extractants, specifically crown ethers and their derivatives, were chosen for these studies. Carrier-free radionuclides, used in these studies, of the homologs of Fl and element 115 were obtained by proton activation of high purity metal foils at the Lawrence Livermore National Laboratory (LLNL) Center for Accelerator Mass Spectrometry (CAMS): natIn(p,n)113Sn, natSn(p,n)124Sb, and Au(p,n)197m,gHg. The carrier-free activity was separated from the foils by novel separation schemes based on ion exchange and extraction chromatography techniques. Carrier-free Pb and Bi isotopes were obtained from development of a novel generator based on cation exchange chromatography using the 232U parent to generate 212Pb and 212Bi. Crown ethers show high selectivity for metal ions based on their size compared to the negatively charged cavity of the ether. Extraction by crown ethers occur based on electrostatic ion-dipole interactions between the negatively charged ring atoms (oxygen, sulfur, etc.) and the positively charged metal cations. Extraction chromatography resins produced by Eichrom Technologies, specifically the Pb resin based on di-t-byutlcyclohexano-18-crown-6, were chosen as a starting point for these studies. Simple chemical systems based solely on HCl matrices were explored to determine the extent of extraction for Pb, Sn and Hg on the resin. The kinetics and mechanism of extraction were also explored to determine suitability for a Fl chemical experiment. Systems based on KI/HCl and KI/HNO3 were explored for Bi and Sb. In both cases suitable separations, with high separation factors, were performed with vacuum flow columns containing the Pb-resin. Unfortunately the kinetics of uptake for Hg are far too slow on the traditional crown-ether to perform a Fl experiment and obtain whether or not Fl has true Hg-like character or not. However, the kinetics of Pb and Sn are more than sufficient for a Fl experiment to differentiate between Pb- or Sn-like character. To assess this kinetic issue a novel macrocyclic extractant based on sulfur donors was synthesized. Hexathia-18-crown-6, the sulfur analog of 18-crown-6, was synthesized based with by a template reaction using high dilution techniques. The replacement of oxygen ring atoms with sulfur should give the extractant a softer character, which should allow for far greater affinity toward soft metals such as Hg and Pb. From HCl matrices hexathia-18-crown-6 showed far greater kinetics and affinity for Hg than the Pb-resin; however, no affinity for Pb or Sn was seen. This presumably is due to the fact the charge density of sulfur crown ethers does not point to the center of the ring, and future synthesis of a substituted sulfur crown ether which forces the charge density to mimic that of the traditional crown ether should enable extraction of Pb and Sn to a greater extent than with the Pb-resin. Initial studies show promise for the separation of Bi and Sb from HCl matrices using hexathia-18-crown-6. Other macrocyclic extractants, including 2,2,2-cryptand, calix[6]arene and tetrathia-12-crown-4, were also investigated for comparison to the crown ethers. It was noted that these extractants are inferior compared to the crown and thiacrown ethers for extraction of Fl and element 115 homologs. A potential chemical system for Fl was established based on the Eichrom Pb resin, and insight to an improved system based on thiacrown ethers is presented.

Thermodynamic equilibrium calculations of dimethyl ether steam reforming and dimethyl ether hydrolysis

NASA Astrophysics Data System (ADS)

Semelsberger, Troy A.; Borup, Rodney L.

The production of a hydrogen-rich fuel-cell feed by dimethyl ether (DME) steam reforming was investigated using calculations of thermodynamic equilibrium as a function of steam-to-carbon ratio (0.00-4.00), temperature (100-600 °C), pressure (1-5 atm), and product species. Species considered were acetone, acetylene, carbon dioxide, carbon monoxide, dimethyl ether, ethane, ethanol, ethylene, formaldehyde, formic acid, hydrogen, isopropanol, methane, methanol, methyl-ethyl ether, n-propanol and water. Thermodynamic equilibrium calculations of DME steam reforming indicate complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide at temperatures greater than 200 °C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure ( P = 1 atm). Increasing the operating pressure shifts the equilibrium toward the reactants; increasing the pressure from 1 to 5 atm decreases the conversion of dimethyl ether from 99.5 to 76.2%. The trend of thermodynamically stable products in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol-formaldehyde, formic acid, and acetylene were not observed. Based on the equilibrium calculations, the optimal processing conditions for dimethyl ether steam reforming occur at a steam-to-carbon ratio of 1.50, a pressure of 1 atm, and a temperature of 200 °C. These thermodynamic equilibrium calculations show dimethyl ether processed with steam will produce hydrogen-rich fuel-cell feeds—with hydrogen concentrations exceeding 70%. The conversion of dimethyl ether via hydrolysis (considering methanol as the only product) is limited by thermodynamic equilibrium. Equilibrium conversion increases with temperature and steam-to-carbon ratio. A maximum dimethyl ether conversion of 62% is achieved at a steam-to-carbon ratio of 5.00 and a processing temperature of 600 °C.