Search results for "visual_art.visual_art_medium"

An investigation on using pre-treated tyre rubber as a replacement of synthetic polymers for bitumen modification

2015

Rubberized bitumen obtained through a swelling process, has widely proven to be a successful technology for asphalt pavement applications and a solution to reduce the dismantling of tyre rubber on landfills. However, this technology presents two main operative issues which needs the adoption of costly special equipment. Firstly, significant high value of High Temperature Viscosity (HTV) which imposes mixing and compaction difficulties and leads to increased energy consumption and emissions. Furthermore, during the hot storage period, phase separation between rubber particles and the base bitumen could occur. Developing Recycled Tyre Rubber Modified Bitumen (RTR-MBs) with improved storage st…

Vaccinium Genus Berry Waxes and Oils

2019

Vaccinium is a common and widespread genus of about 450 species of shrubs or dwarf shrubs in the heath family (Ericaceae). Most of Vaccinium species produce edible berries and many berries are widely cultivated at an industrial scale, for example, bilberries (Vaccinium myrtillus L.), highbush blueberries (Vaccinium corymbosum L.), lingonberries (Vaccinium vitis-idaea L.), and cranberries (Vaccinium oxycoccos L.). These berries are important articles in the markets of berries in Northern countries both raw, and processed. Vaccinium berries are at first valued considering high vitamin concentrations as well as high concentrations of phenolics. However, also oils and waxes (lipids) of Vacciniu…

Sesquiterpene lactones, waxes and volatile compounds from Artemisia herba-alba subspecies Valentina

1979

Abstract The structures of two sesquiterpene lactones isolated from Artemisia herba-alba subsp. valentina have been determined by spectroscopic methods. One of these was dihydroreynosin, the other was a new compound assigned the name torrentin. The chemical compositions of a wax and a hydrocarbon fraction from the essential oil have also been investigated.

Deformation recovery behavior of a solid polymer after tensile yielding

1984

In this work the deformation recovery behavior of an amorphous polymer after large tensile deformation is studied at different temperatures. The effect of three parameters other than temperature has been pointed out in previous works (1–3).

Deformation recovery behaviour of a solid polymer after tensile yielding

1987

In this work the deformation recovery behavior of an amorphous polymer after large tensile deformation is studied at different temperatures. The effect of three parameters other than temperature has been pointed out in previous works (1–3). The data here presented indicate that the influence of all parameters, including temperature, on recovery behavior can be related to the residual stress, σ *, at the beginning of recovery test. This suggests to plot the recovery versus time curves, relative to different sets of parameters including temperature, by means of the same normalizing groups which were adopted in (2), thus shifting all curves towards a single master curve.

Interaction of Dimethyltin(IV)2+ Cation with Gly-Gly, Gly-His, and Some Related Ligands. A New Case of a Metal Ion Able To Promote Peptide Nitrogen D…

1999

Equilibrium (pH-metric) and spectroscopic (1H,13C, and 119Sn NMR and 119Sn Mossbauer) studies were performed to characterize the interaction of the dimethyltin(IV) cation with glycine, glycyl-glycine (Gly-Gly), imidazole-4-acetic acid, histamine, histidine, glycyl-histamine, glycyl-histidine (Gly-His), and β-alanyl-histidine (carnosine). For histamine and glycyl-histamine (having only nitrogen donor atoms) no complex formation was detected. The hydrolyzed species of the dimethyltin(IV) cation are always dominant over the complexes formed with the other ligands, except with Gly-Gly and Gly-His. For these two ligands, {COO-,N-,NH2} coordinated complexes are dominant in the neutral pH range wi…

The Mechanism of Action of Carbonic Anhydrase

1990

A survey of the structure-function relationship in the enzyme carbonic anhydrase is presented. The coordination number around the metal ion in derivatives inhibited with some anions is stressed as well as the role of the cavity in determining the coordination number. Inferences on the enzyme-substrate interactions are presented.

2019

Water-soluble chlorophyll proteins (WSCP) from Brassicaceae form homotetrameric chlorophyll (Chl)–protein complexes binding one Chl per apoprotein and no carotenoids. Despite the lack of photoprotecting pigments, the complex-bound Chls displays a remarkable stability toward photodynamic damage. On the basis of a mutational study, we show that not only the presence of the phytyls is necessary for photoprotection in WSCPs, as we previously demonstrated, but also is their correct conformation and localization. The extreme heat stability of WSCP also depends on the presence of the phytyl chains, confirming their relevance for the unusual stability of WSCP.

(-)-(5S,8S,9R,10S,13R,14R)-15,16-Dideoxy-16,17-epoxy-16-oxospongian-15-yl acetate.

2006

The title compound (aplyroseol-14), C22H34O4, exhibits a lactone-based structure that is novel for spongian-type diterpenoids. The structure, which features a six-membered lactone ring, was proposed by Arno, Gonzalez & Zaragoza [J. Org. Chem. (2003), 68, 1242–1251] on the basis of spectroscopic data and chemical correlations. This assignment has been confirmed, and it is shown that the mol­ecule contains a trans–anti–trans 6/6/6 tricyclic hydro­carbon system and that the acetoxy­methyl group lies in an equatorial position. Pairs of near-linear C—H⋯O inter­actions link mol­ecules into extended chains.

Conservation of amino-acid chromatograms.

1951

IN filter-paper partition chromatography, the ninhydrin reaction has been used almost exclusively for the identification and quantitative assay of amino-acids. One of the chief disadvantages of the blue pigment formed in this reaction is its rapid fading on filter-paper chromatograms. This makes it difficult to construct permanent or semi-permanent reference maps from which not only the type of amino-acid, but also the approximate quantity of the unknown mixture, can be deduced.