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281.
Synthesis of oxadiazoloquinoxaline,oxathiadiazoloquinoxaline and oxadiazolobenzothiazine derivatives
Konstantina C. Fylaktakidou Konstantinos E. Litinas Athanasios Saragliadis Spyros G. Adamopoulos Demetrios N. Nicolaides 《Journal of heterocyclic chemistry》2006,43(3):579-583
Bis‐amidoxime 1 reacts with phosgene, thiophosgene and thionylchloride to give the corresponding bisfused oxadiazolo‐ and oxathiadiazoloquinoxalines 2, 4, 5 along with the unexpected furazano‐derivative 3 , while monoamidoximes 9, 13 by treatment with ethyl chloroformate affords the oxadiazoloquinoxaline and the oxadiazolobenzothiazine derivatives 14, 15 along with the dicarboxylated product 16 . 相似文献
282.
An efficient four-step synthetic strategy able to fully discriminate hydroxyphosphinyl and carboxylic groups of Fmoc-phosphinic building blocks and related analogues has been developed. The proposed method applies selective acidic removal of the phenacyl (Pac) group from the hydroxyphosphinyl functionality and protection by the 1-adamantyl (Ad) group. Reductive removal of the Pac group from the carboxylic functionality leads to Fmoc-protected phosphinic pseudodipeptidic units suitable for phosphinic peptide and library development using solid-phase peptide synthesis (SPPS). 相似文献
283.
Konstantina Tsaousi Athanasios A. Koutinas Argyro Bekatorou Paul Loukatos 《Applied biochemistry and biotechnology》2010,162(2):594-606
Low-cost dried yeasts immobilized on delignified brewers' spent grains for use in wine making and brewing were produced by
simple thermal drying techniques. To optimize the thermal drying process, vacuum and air stream conditions were examined.
Drying of thin layers of the biocatalysts was performed at low (30–38 °C) and high temperatures (40–70 °C). The fermentation
efficiency of the thermally dried biocatalysts was acceptable, with immobilized cells showing a significantly higher thermotolerance
compared with free cells. Immobilized cells dried at high temperatures presented slightly improved glucose fermentation efficiency
compared with the low-temperature dried biocatalysts. Gas chromatography–mass spectrometry analysis of aroma volatiles of
the fermented products revealed an increase of esters, lower higher alcohol formation, and significantly lower concentration
of carbonylic compounds. 相似文献
284.
Athanasios N. Lyberopoulos 《Journal of Functional Analysis》2009,257(11):3593-3657
We study the existence versus absence of nontrivial weak solutions for a class of indefinite quasilinear elliptic problems on unbounded domains with noncompact boundary, in the presence of competing lower order nonlinearities with potentials decaying to zero at infinity. 相似文献
285.
Athanasios Kehagias Geoffrey Hollinger Sanjiv Singh 《Mathematical and Computer Modelling》2009,50(9-10):1305-1317
Using concepts from both robotics and graph theory, we formulate the problem of indoor pursuit/evasion in terms of searching the nodes of a graph for a mobile evader. We present the IGNS (Iterative Greedy Node Search) algorithm, which performs offline guaranteed search (i.e. no matter how the evader moves, it will eventually be captured). Furthermore, the algorithm produces an internal search (the searchers move only along the edges of the graph; “teleporting” is not used) and exploits non-monotonicity, extended visibility and finite evader speed to reduce the number of searchers required to clear an environment. We present search experiments for several indoor environments, in all of which the algorithm succeeds in clearing the graph (i.e. capturing the evader). 相似文献
286.
Kottas Athanasios Gelfand Alan E. 《Methodology and Computing in Applied Probability》2001,3(4):427-442
In comparing two populations, sometimes a model incorporating a certain probability order is desired. In this setting, Bayesian modeling is attractive since a probability order restriction imposed a priori on the population distributions is retained a posteriori. Extending the work in Gelfand and Kottas (2001) for stochastic order specifications, we formulate modeling for distributions ordered in variability. We work with Dirichlet process mixtures resulting in a fully Bayesian semiparametric approach. The details for simulation-based model fitting and prior specification are provided. An example, based on two small subsets of time intervals between eruptions of the Old Faithful geyser, illustrates the methodology. 相似文献
287.
Haralampos Zois Athanasios Kanapitsas Polycarpos Pissis Lazaros Apekis Eugene Lebedev Yevgen P. Mamunya 《Macromolecular Symposia》2004,205(1):263-272
Microstructure-dielectric properties relationship and molecular mobility of organic/inorganic polymer composites (OIPCs), consisting of polyurethane (PU) and sodium silicate (NaSi), were investigated in this work. Broadband dielectric relaxation spectroscopy (DRS) and thermally stimulated depolarization current (TSDC) techniques were employed. Our interest was focused on the study of the glass transition mechanism and conductivity relaxation. The influence of the molecular weight of PU and inorganic phase content on the dielectric properties of the composites was of particular interest. Glass transition temperature shifts to higher temperatures with the addition of NaSi. The overall molecular mobility was found to increase in the composites, compared to the pure PU matrix. The results are more intense for the composites based on the PU with low molecular weight. 相似文献
288.
Yevgen Mamunya Athanasios Kanapitsas Polycarpos Pissis Gisele Boiteux Eugene Lebedev 《Macromolecular Symposia》2003,198(1):449-460
Organic-inorganic polymer blends (OIPB) were obtained by reaction of organic and inorganic oligomers. The organic oligomer was synthesized with 2,4-toluene diisocyanate (TDI) and oligooxypropylene glycols (OPG) with various molecular weights (MW). The inorganic component was a water solution of sodium silicate. The OIPB obtained are hydrophilic and have great water sorption ability (the relative weight of sorbed water reaches 2000 %). The kinetics of water sorption and the changes of electrical conductivity during sorption were studied. Sorption ability, and mechanical, electrical and dielectric properties of OIPB depend on molecular weight of OPG: conductivity increases with increasing MW, whereas the sorption ability correlates with the mechanical properties. The influence of the inorganic phase content on the electrical and dielectric properties was studied as well. 相似文献