Search results for "Urea"
showing 10 items of 888 documents
Una proposta d'anàlisi de la formalitat diafàsica a partir d'un capítol del "Flos sanctorum"
2011
Aquest treball proposa una metodologia per a poder discriminar els graus de formalitat d'un text en confrontació amb unes altres. L'anàlisi es basa en dues parts. En la primera, esrudiem característiques lingüístiques que es mostren més sensibles per a assenyalar el grau de formalitat del text, com són el passat simple, l'anàfora, els relatius, els connectors i locucions conjuntives, el subjuntiu o la formació de paraules amb tres classes de sufixos cultes: -ment, -able/-ible i -tat, -edat, -etat, -itat. En la segona part, ens ocupem de l'anàlisi formal a partir de l'estudi de recursos com les veus d'autoritat, l'estructura i la temàtica. El corpus en què es basa el nostre estudi és el capí…
Volatile components from aerial parts of Centaurea gracilenta and C. ovina ssp. besserana growing wild in Bulgaria
2011
The essential oils of Centaurea gracilenta Velen. (CG) and C. ovina Pall. ex Willd. ssp. besserana (DC.) Dostál (COB) growing wild in Bulgaria, were studied by GC and GC-MS. Forty-five compounds for CG, representing the 90.1% of the oil, and 68 compounds for COB, representing the 91.9% of the oil, were identified. The oils were rich in sesquiterpenoids (33.4% for CG and 27.3% for COB), hydrocarbons (28.3% for CG and 10.7% for COB) and carbonylic compounds (12.7% for CG and 13.1% for COB). Fatty acids were abundant only for COB (31.3%). beta-Eudesmol (12.8%), nonacosane (11.8%) and p-vinyl guiacol (7.5%) were recognized as the main constituents for CG, while hexadecanoic acid (21.4%), spathu…
Cyclic tetraureas with variable flexibility--synthesis, crystal structures and properties.
2008
Macrocyclic molecules containing several amide or urea functions may serve as anion receptors. We describe the synthesis of 32-membered macrocycles, in which four rigid xanthene units (X) and/or diphenyl ether units (D) as flexible analogues are linked via urea groups. All six possible combinations of these units (XXXX, XXXD, XXDD, XDXD, XDDD and DDDD) were synthesized and two examples were characterised by single-crystal X-ray analyses (DDDD and two structures for XXXD). Both macrocycles showed distinct differences in their overall conformation and consequently in their hydrogen-bonding pattern. Hydrogen-bonded solvent molecules are found for both compounds and intramolecular hydrogen bond…
1-(3′,6′-Dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9′-xanthen]-5-yl)-3-[4-({4-[1-(4-fluorophenyl)-1H-imidazol-5-yl]pyridin-2-yl}amino)phenyl]thiourea …
2016
The title compound, which crystallized as a methanol monosolvate, C41H27FN6O5S·CH3OH, was synthesized as a probe for a fluorescence polarization-based competition binding assay. The isobenzofuran fused-ring system is close to planar and orientated almost perpendicular to the central ring of the xanthene system. The dihedral angle between the benzene rings of the xanthene system is 10.0 (2)°, indicating a butterfly-like orientation. A short intramolecular C—F...π contact [F...π = 3.100 (4) Å and C—F...π = 139.9 (3)°] to the six-membered ring of the isobenzofuran system may influence the molecular conformation. The methanol solvent molecule is disordered over two orientations in a 0.6:0.4 rat…
Urea Glass Route as a Way to Optimize YAGG:Ce3+,Cr3+,Pr3+ Nanocrystals for Persistent Luminescence Applications
2022
A new approach for the synthesis of Y3Al2Ga3O12 (YAGG) nanophosphors allowing the preparation of crystallites with sizes starting from 45 nm is presented. The controllability of the energy and trap density of the resulting material samples by annealing temperature was confirmed by thermoluminescence (TL) measurements. It has been shown that the annealing of samples at temperatures up to 1300 degrees C does not cause any substantial growth of crystallites, still remaining below 100 nm, but leads to changes in the activation energy of the persistent luminescence (PersL) process. On the other hand, annealing above 1400 degrees C results in grain growth on the submicron scale, which was confirm…
Le désherbage d’automne contre l’ergot du seigle les traitements herbicides d’automne, un levier chimique efficace de lutte contre l’ergot du seigle
2013
Context and study: Trials in field allowed to show a link between a good grass weeding (blackgrass and rye grass) and extent of ergot contaminations. Makhteshim Agan France and Arvalis tested on 15 trials in 2011-2012, 2 ureas, as isoproturon against blackgrass, alone or in pro-gram with a sulfonylurea, to evaluate their indirect effect against ergot. Field trials were set up on sensitive crops to ergot (rye, wheat and triticale) infested with artificial ergot contaminations and weed seeds sensible to ALS. Contaminations were evaluated first in field on weeds and on crop, and then on harvest, by assessing sclerotia and alkaloids content in harvested samples. results: For all evaluation mean…
Effect of cropping cycles and repeated herbicide applications on the degradation of diclofop-methyl, bentazone, diuron, isoproturon and pendimethalin…
2002
A greenhouse study was conducted to investigate the ability of four crops (wheat, corn, oilseed rape and soybean) to influence the degradation of bentazone, diclofop-methyl, diuron, isoproturon and pendimethalin in soil. The present study showed that microbial biomass-carbon was significantly higher in planted soils than in bulk soil, especially with wheat and corn, after several cropping cycles. The biomass in corn and soybean planted soils was adversely affected by bentazone but recovered after three cropping cycles. In wheat-planted soils, diclofop-methyl application resulted in persistent increase of the amount of microbial biomass. Bentazone did not show accelerated degradation even af…
Salivary protein profiles are linked to bitter taste acceptance in infants
2014
Salivary protein profiles are linked to bitter taste acceptance in infants. Séminaire final du projet européen HabEat
Genomic approach to search for IPU degrading gene: catA as a possible gene target responsible for 4- isopropyl aniline degradation
2009
Affiche, résumé étendu; Genomic approach to search for IPU degrading gene: catA as a possible gene target responsible for 4- isopropyl aniline degradation
Autumn herbicides, an efficient chemical tool against ergot of grasses
2013
Maktheshim Agan France analyzed 14 weeding trials, carried out in 2011-2012, to identify the indirect effect of weeding on the development of ergot. Field trials were set up on straw cereals (rye, wheat and triticale), with a contamination of ergot sclerotia and artificial infestation of grassy weeds susceptible to sulfonylureas. Two herbicides: isoproturon and chlortoluron, used alone or followed by a sulfonylurea, were compared to untreated control. All the assessments show that herbicides decreased the amount of sclerotia and even more the alkaloid content in harvest. This effect was higher with the herbicide program (urea applied in autumn /sulfonylurea at the end of winter). This study…