Search results for "AROMA"
showing 10 items of 1006 documents
Self-assembly mechanism based on charge density topological interaction energies
2017
The packing interactions have been evaluated in the context of the self-assembly mechanism of crystal growth and also for its impacts on the aromaticity of the trimesate anion. The structure of ethylammonium trimesate hydrate (1) measured at 100 K and a charge density model, derived in part from theoretical structures, is reported. Theoretical structure factors were obtained from the geometry-optimized periodic wave function. The trimesic acid portion of 1 is fully deprotonated and participates in a variety hydrogen bonding motifs. Topological analysis of the charge density model reveals the most significant packing interactions and is then compared to a complementary analysis performed by …
Study of aromatic nucleophilic substitution with amines on nitrothiophenes in RTILs: are the different effects on the behavior of para-like and orto-…
2006
The kinetics of the nucleophilic aromatic substitution of some 2-L-5-nitrothiophenes (para-like isomers) with three different amines (pyrrolidine, piperidine, and morpholine) were studied in three roomtemperature ionic liquids ([bmim][BF4], [bmim][PF6], and [bm2im][BF4], where bmim ) 1-butyl-3- methylimidazolium and bm2im ) 1-butyl-2,3-dimethylimidazolium). To calculate thermodynamic parameters, a useful instrument to gain information concerning reagent-solvent interactions, the reaction was carried out over the temperature range 293-313 K. The reaction occurs faster in ionic liquids than in conventional solvents (methanol, benzene), a dependence of rate constants on amine concentration sim…
Retro Diels Alder protocol for regioselective synthesis of novel [1,2,4]triazolo[4,3-a]pyrimidin-7(1H)-ones
2020
Reactions of diastereochemically varied norbornene-condensed 2-thioxopyrimidin-4-ones6and10with variously functionalized hydrazonoyl chlorides2a-hgave regioselectively angular norbornene-based [1,2,4]triazolo[4,3-a]pyrimidin-7(1H)-ones7a-hand11a,c-e, respectively. Thermal retro Diels-Alder (RDA) reaction of7a-hand11a,c-eresulted in the target compounds4a-has single products. On the other hand, reactions of thiouracil1and hydrozonoyl chlorides2a-egave regioselectively [1,2,4]triazolo[4,3-a]pyrimidinone-5(1H)-ones3a-e. The opposite regioselectivity of thiouracil1and norbornene-condensed 2-thioxopyrimidin-4-ones6and10was attributed to electronic factors according to DFT calculations. The angul…
Synthesis of Polycyclic Indolines utilizing a reduction/cyclization cascade reaction
2021
Subsequent reduction and dearomatizing cyclization reactions open up an entry into the synthesis of novel N-fused polycyclic indolines. The dearomatizing cyclization as key step of the sequence proceeds well with Cu(OTf)2 or TfOH as catalyst. At elevated temperature reduction of nitro-substituted precursors with iron under acidic conditions affords a broad variety of polycyclic indolines directly in a two-step cascade reaction in good to excellent yields. Using the developed protocol, the alkaloids Tryptanthrin and Phaitanthrin C have been prepared. peerReviewed
Toistuvat ruudut sarjakuvaromaanissa Watchmen
2014
Tarkastelen pro gradu -tutkielmassani toistuvia ruutuja Alan Mooren, Dave Gibbonsin ja John Higginsin sarjakuvaromaanissa Watchmen (1986–87). Teokseen sisältyy useita kymmeniä sarjakuvaruutuja, jotka esitetään sarjakuvan mittaan useammin kuin yhden kerran – useimmin toistetut jopa neljästi tai viidesti. Saman ruudun toistuminen on mielenkiintoinen sarjakuvakerronnan keino, jota ei sellaisenaan esiinny muissa mediumeissa. Lähestyn toistuvia ruutuja sarjakuvakerronnan tutkimuksen eli sarjakuvanarratologian näkökulmasta. Testaan samalla erityisesti kerronnan näkökulmaan tai fokalisaatioon sekä kertojaan liittyvien teoreettisten jäsennysten soveltumista sarjakuvakerronnan analyysiin. Watchmenin…
Screening of halogenated aromatic compounds in some raw material lots for an aluminium recycling plant
2004
Four samples of scrap raw materials for an aluminium recycling plant were screened for the occurrence of persistent halogenated aromatic compounds. The samples contained waste from handling of electric and electronic plastics, filter dust from electronic crusher, cyclone dust from electronic crusher and light fluff from car shredder. In our screening analyses, brominated flame retardants were observed in all samples. Polybrominated diphenyl ethers (PBDE) were identified in all samples in amounts of 245–67450 ng/g. The major PBDE congeners found were decabromo- and pentabromodiphenyl ethers. 1,1-bis(2,4,6-tribromophenoxy)ethane, hexabromobenzene, ethyl-pentabromobenzene, tetrabromobisphenol-…
Hazardous air pollutants and primary liver cancer in Texas.
2016
The incidence of hepatocellular carcinoma (HCC), the most common primary liver cancer, is increasing in the US and tripled during the past two decades. The reasons for such phenomenon remain poorly understood. Texas is among continental states with the highest incidence of liver cancer with an annual increment of 5.7%. Established risk factors for HCC include Hepatitis B and C (HBV, HCV) viral infection, alcohol, tobacco and suspected risk factors include obesity and diabetes. While distribution of these risk factors in the state of Texas is similar to the national data and homogeneous, the incidence of HCC in this state is exceptionally higher than the national average and appears to be di…
Metaromanzo di ritorno
2011
High-impact wine aroma production by Saccharomyces yeasts and generation of yeast hybrids for industrial application
2022
El vino se diferencia de la mayoría de las bebidas fermentadas, como por ejemplo de la cerveza, por su gran complejidad y diversidad aromática. En su aroma se distinguen aquellos compuestos que constituyen la nota vinosa, base similar en todos los vinos, y los aromas de alto impacto, compuestos menos abundantes, pero de potentes notas florales y frutales. Así, el aroma del vino se produce a lo largo de la vinificación, en su mayor parte durante la fermentación alcohólica y en él influyen principalmente la variedad de uva y la acción de la levadura. Las levaduras han sido explotadas durante muchos años por el ser humano para la producción de vino, y en el caso de la fermentación las cepas ví…
Ricerca di lieviti autoctoni per migliorare il profilo aromatico delle birre artigianali
2019
In corso d’opera un’analisi di matrici appartenenti a diverse nicchie ecologiche con l’obiettivo di individuare lieviti dalle caratteristiche tecnologiche e qualitative ottimali