Search results for "efficien"

Morphogenesis in callus and single-cell cultures ofLavandula latifoliaMedicus

1990

Procedures and factors promoting plant regeneration from callus and isolated cells were investigated in Lavandula latifolia Medicus. Callus was obtained from cotyledon explants cultured on MS medium supplemented with 0.34 (xM 2,4-D. These calli regenerated adventitious buds when transferred to MS medium containing either BA or several auxin (IAA or NAA)/BA combinations, best results being obtained in the presence of 8.80 (mi BA alone or in combination with 0.06 and 0.60 (xM IAA or NAA. Single cells from cotyledon-derived calli were able to proliferate as callus when plated in MS medium supplemented with IAA or several IAA/BA combinations. Best plating efficiency was achieved when cells were…

Photovoltaic effect in bulk heterojunction system with glass forming indandione derivative DMABI-6Ph

2018

The aim of the work is to evaluate possible use of 2-[[4-(bis(2-trityloxyethyl)amino)phenyl]methylene]indane-1,3-dione (DMABI-6Ph) as light absorbing material for solar cells. DMABI-6Ph is a perspective material due to its good photoelectrical, thermal and chemical properties. The main advantage of DMABI-6Ph is its ability to form amorphous films by wet-casting methods thus allowing using the compound in organic solar cells made from solution. For now most popular materials for solution processable solar cells are polymer P3HT and fullerene derivative PCBM, but lot of investigations are in the field of new low molecular weight materials to replace the polymer. Photoelectrical measurements w…

Effect of konjac glucomannan addition on aroma release in gels containing potato starch.

2014

International audience; The present study aimed to measure the retention of aroma compounds (ethyl acetate, ethyl hexanoate and carvacrol) in dispersions based on konjac glucomannan and/or potato starch, and to highlight the influence of konjac glucomannan on the mechanisms involved in aroma retention. Publications on the effect of konjac glucomannan on aroma release are scarce. Konjac glocomannan is a polysaccharide used as a food additive for its viscous and emulsifying properties. Retention of aroma compounds in dispersions was calculated from partition coefficients which were measured using the phase ratio variation method. This method, consisting of analyses of the headspace at equilib…

Efficient energy transfer in a tri-chromophoric dyad containing BODIPYs and corrole based on a truxene platform

2018

A star-shaped molecule was designed and synthesized based on a known central truxene platform. Two BODIPY derivatives and one corrole macrocycle were introduced and connected to the 2, 7 and 12-positions of the truxene unit by Suzuki coupling. The dyad was fully characterized by UV-vis absorption, proton nuclear magnetic resonance, mass spectrometry. The direction of energy transfer upon electronic excitation was explored, and the star-shaped molecule system exhibits a highly efficient photoinduced energy transfer process from the excited BODIPY part to the corrole unit.

Herstellung, charakterisierung und lösungseigenschaften von einheitlichen styrol-α-methylstyrol block-copolymeren

1977

An improved anionic polymerization technique for the preparation of highly uniform styrene/α-methylstyrene linear two-block copolymers is described. Three sets of samples with molecular weights M were prepared under equal experimental conditions, namely polystyrenes (2 · 105 < M < 3 · 106), poly(α-methylstyrene)s (7 · 104 < M < 4 · 106), and block copolymers (2 · 105 < M < 2,5 · 106). Ultracentrifugation in a density-gradient does not show any chemical heterogeneities in the block copolymers. The molecular polydispersity U = Mw/Mn–1 is U = 0,03 or less as estimated from GPC-measurements. The high molecular and chemical homogeneity of the block copolymers and the optical similarity of the tw…

Über die polymeranaloge bromierung von naturkautschuk und einige lösungseigensch aften des bromkautschuks. Über die molekularen konstanten von naturk…

1961

Naturkautschuk last sich in verdunnter Losung in Cyclohexan bromieren, wobei das Molekulargewicht entsprechend dem Bromgehalt zunimmt (polymeranaloge Umsetzung). Fur Bromkautschuk steigenden Bromgehalts wird Cyclohexan ein zunehmend schlechteres Losungsmittel, was sich in einer Abnahme des 2. osmotischen Virialkoeffizienten und einer Kontraktion des Molekulknauels zeigt. Dieses Ergebnis wird in quantitativer Ubereinstimmung durch Viskositats- und Lichtstreuungsmessungen erhalten. Cyclohexanlosungen von Bromkautschuk mit 43% Brom haben bei Zimmertemperatur einen Θ-Punkt. In diesem Zustand ist der Knauel 1,74mal groser als bei freier Drehbarkeit, in ziemlich guter Ubereinstimmung mit dem an a…

Large-Scale Synthesis of Mammalian Gonadoliberin without protection of side-chain functions

1991

A simple, Large-scale preparation of mammalian gonadoliberin was elaborated using classical solution methods without protecting side-chain functions. At the final stage, a hexapeptide segment was condensed with the corresponding tetrapeptide and the obtained decapeptide was purified by a single chromatographic procedure on silica gel. The total efficiency of the whole synthesis and the purity of the product amounted to 34% and 98.3%, respectively.

Bestimmung der molekularen konstanten von naturkautschuk. II. Viscositätszahl (staudiger-index), sedimentation und diffusion in cyclohexan

1959

Der Einflus der Losebedingungen auf die Viskositatszahl von Kautschuk in Cyclohexan ist verschwindend, wenn Sauerstoff und Licht ausgeschaltet sind. Es ergibt sich fur den in dieser Arbeit untersuchten Crepe [η] = 650 ± 20 ccm g−1, unabhangig von der Temperatur, der Losedauer und der Aufbewahrungszeit der Losungen. Aus Ultrazentrifugen- und Diffusionsversuchen ergibt sich fur die Sedimentationskonstante s0 = 4,6·10−13 und fur die Diffusionskonstante D0 = 0,48·10−7 cm2sec−1. Das partielle spezifische Volumen des Kautschuks in Cyclohexan ist v2 = 1,10 cm3g−1. Darauserhalt man fur das Molekulargewicht M = 1,6·106. Die thermodynamische Auswertung der Konzentrationsabhangigkeit von s und D zeigt…

1985

Samples of ring and open chain polystyrene in dilute perdeuterated toluene solution were measured by small angle neutron scattering up to a value of the scattering vector Q = 2 nm−1. The molar masses 12000 ≤ M/(g/mol) ≤ 22000, the mean square radii of gyration 〈R2〉 and the second virial coefficients A2 of the samples were determined. The results are compared to theories which describe the dependencies 〈R2〉 = f(M) and A2 = f(M) for both cyclic and linear chain molecules. A qualitative agreement between theory and experiment is obtained.

TiO2-Based Photocatalysis for Organic Synthesis

2010

A major aim of the contemporary chemistry is to replace old environmentally hazardous processes with new, energy efficient routes allowing to reduce or totally avoid the use and production of harmful chemicals and to maximise the quantity of raw material that ends up in the final product. This chapter gives an account of TiO2-based selective photocatalysis as a green synthetic tool for the production of organics. Some case studies of the most common transformations carried out by means of photocatalytic reactions are illustrated in a midway perspective between photochemistry and organic chemistry.