Search results for "STEAM"
showing 10 items of 125 documents
Chemical and physical modification of hemp fibres by steam explosion technology
2013
In current research attempt has been made to analyse hemp fibres treated with steam explosion (SE) technology. Disintegration of hemp fibres separated from non-retted, dew-retted and dried stems of hemp ('Purini')[1] by alkali treatment and steam explosion (SE) were investigated. An average intensive SE in combination with the hydro-thermal and alkali after-treatment allows decreasing the diameter of hemp fibres and reduce the concentration of non-celluloses components, among them hemicelluloses, lignin, pectin, waxes and water [1;2].
Citrus somatic hybrid leaf essential oil
2000
The essential oil from the leaves of a Citrus interspecific somatic hybrid obtained by symmetric protoplast fusion between ‘Milam’ lemon [purported sexual hybrid of C. Jambhiri Lush (×) C. sinensis] and ‘Femminello’ lemon (C. limon L. Burm f.) has been characterized by steam distillation GC–MS analysis and its composition compared with that of the corresponding oils obtained from the parent plants. The amount (%) of the different classes of substances present in the oils show, in the new hybrid, an overall lowering of the hydrocarbon fraction and an increase of the oxygenated components. The somatic hybrid shows a close similarity in the amounts of terpenes, sesquiterpenes and alcohols with…
Composition of the essential oil fromflowerheads ofChrysanthemum coronarium L.(Asteraceae) growing wild in Southern Italy
2004
The essential oils from the aerial parts of Chrysanthemum coronarium L. (Asteraceae) growing wild in two different localities of Southern Italy, Lascari (L) and Palinuro (P), were obtained by hydrodistillation in a 0.13-0.16% yield. The oils were analysed by GC and GC-MS; 68 constituents, amounting to 89.0% of the oil (L), and 43 constituents, amounting to 91.6% of the oil (P), were identified. The trans-spiroketal-enol ether 2-(2,4- hexadiynylidene)-1,6-dioxaspiro(4,4)non-3-ene (trans-tonghaosu) with chrysanthenyl and lyratyl esters and camphor were the main components of the oils. Copyright © 2004 John Wiley & Sons, Ltd.
Chemical composition of the essential oils fromEriocephalus africanus L. var.africanus populations growing in Spain
2007
Essential oils from the aerial parts of three Eriocephalus africanus L. var. africanus populations were analysed by means of GC–FID and GC–MS. Sixty-one constituents were identified, representing more than 96% of the total oil composition. Artemisia ketone (56.46–56.58%), intermedeol (9.19–11.63%) and γ-eudesmol (4.26–5.64%) were the main compounds. Application of the Pearson correlation coefficient showed high similarity between the nine samples analysed. Copyright © 2007 John Wiley & Sons, Ltd.
Composition of the essential oil ofPallenis spinosa (L.) Cass. (Asteraceae)
2003
The essential oil of Pallenis spinosa (L.) Cass. was obtained by hydrodistillation. In total 38 components were identified by GC and GC–MS. Oxygenated sesquiterpenoids amounted to 60.2% of the oil. The main components were germacra-1(10),5-dien-3,4-diol (18.4%), α-cadinol (14.1%), 3-acetoxygermacra-1(10),5-dien-4-ol (13.0%), T-cadinol (8.2%) and δ-cadinene (5.8%). The oil does not show antimicrobial activity. Copyright © 2003 John Wiley & Sons, Ltd.
Chemical composition and antimicrobial activity of the essential oil ofPhlomis ferruginea Ten. (Lamiaceae) growing wild in Southern Italy
2006
The essential oil of aerial parts of Phlomis ferruginea (Lamiaceae), growing wild in Southern Italy, was obtained by hydrodistillation and analysed by GC and GC–MS. 60 compounds, representing 92.3% of the oil, were identified. The major components were β-caryophyllene (15.6%), hexadecanoic acid (12.8%), germacrene D (8.9%), caryophyllene oxide (6.7%) and α-thujone (5.5%). The evaluation of antimicrobial activity against some bacterial species has been tested. Copyright © 2006 John Wiley & Sons, Ltd.
Cysteamine and its homoleptic complexes with group 12 metal ions. Differences in the coordination chemistry of ZnII, CdII, and HgII with a small N,S-…
2005
2-Ammoniumethanethiolate, (-)SCH(2)CH(2)NH(3)(+), the first structurally characterized zwitterionic ammoniumthiolate, is the stable form of cysteamine (HL) in the solid state and in aqueous solution. Reactions of ZnCl(2), Cd(Oac)(2), and HgCl(2) with cysteamine and NaOH in a 1:2:2 ratio, respectively, lead to the homoleptic complexes ML(2). Their single-crystal X-ray structures demonstrate basic differences in the coordination chemistry of Zn(II), Cd(II), and Hg(II). While chelating N,S-coordination modes are found for all metal ions, Zn(II) forms a mononuclear complex with a distorted tetrahedral Zn(N(2)S(2)) coordination mode, whereas Hg(II) displays a dimer with Hg(N(2)S(2)) coordinated …
Effects of solvent-free microwave extraction on the chemical composition of essential oil of Calamintha nepeta (L.) Savi compared with the convention…
2008
The essential oil of Calamintha nepeta has been obtained by solvent-free microwave extraction (SFME) and by classical hydrodistillation (HD). A comparative qualitative-quantitative study on the composition of the oils was carried out. A total of 38 compounds, constituting 97.6% of the oil, were identified in the oil obtained by SFME, whereas 46 compounds, representing 95.4% of the oil, were characterized in the HD oil. SFME-distilled oil is richer in lightly oxygenated monoterpenes (LOM) than HD oil. It also has a higher amount of sesquiterpenes and a lower quantity of hydrocarbon monoterpenes. HD oil seems to be affected by chemical changes more than SFME oil.
H2-Antihistaminica, 1. Mitt.: 2-Substituierte 4-[[2-(N′-Methyl-thioureido)-äthylmercapto]-methyl]-imidazole
1976
Es wird die Synthese der 2-substituierten 4-[[2-(N′-Methylthioureido)-athylmercapto]-methyl]-imidazole 5a–f als potentielle H2-Antihistaminica beschrieben. Ausgehend von den Imidazol-4-carbinolen 3a–f lassen sich die 2-substituierten 4-[(2-Amino-athylmercapto)-methyl]-imidazole 4a–f durch saurekatalysierte Reaktion mit Cysteamin darstellen und mit Methylisothiocyanat in die entsprechenden Thioharnstoffderivate 5 uberfuhren. 2-Substituted 4-[[2-(N′-Methyl-thioureido)-ethylmercapto]-methyl]-imidazoles The synthesis of 2-substituted 4-[[2-(Ns′-methyl-thioureido)-ethylmercapto]-methyl]-imidazoles 5a–f, as potential H2-antihistaminics, is described. The acid catalyzed reaction of the imidazole-4…
Geometrinen hahmottaminen sosiaalisena, vuorovaikutteisena ja kehollisena toimintana
2022
Matematiikan ja luonnontieteiden oppimista käsittelevässä tutkimuksessa on viime aikoina korostettu kehon, kognition ja vuorovaikutuksen läheistä yhteyttä. Tässä artikkelissa pohdimme, millä tavoin geometrinen hahmottaminen on sosiaalista, vuorovaikutteista ja materiaalien välittämää kehollista toimintaa. Tarkastelemme eräässä kouluajan ulkopuolella järjestetyssä STEAM-työpajassa kerättyä videoaineistoa keskustelunanalyysin menetelmin. Työpajassa alakouluikäiset oppilaat saivat tehtäväkseen koota pareittain jalkapallon geometrisen representaation 4DFrame-rakennussarjan muoviputkista ja -kiinnikkeistä. Tapaustutkimuksemme osoittaa, miten tämän kaltaisen ohjatun rakennustehtävän aikana katse,…