Search results for "AGGREGATION"
showing 10 items of 566 documents
Thermodynamic properties of alcohols in a micellar phase. Binding constants and partial molar volumes of pentanol in sodium dodecylsulfate micelles a…
1984
Densities of the ternary system water-sodium dodecylsulfate (NaDS)-pentanol and of the binary systems butanol-octane and pentanol-octane were measured at 15, 25, and 35 °C. The apparent molar volume of pentanol in the ternary system was analyzed using a mass-action model for the alcohol distribution in micellar solutions. The partial molar volume of alcohol bound to the micelles and the ratio between the binding constant and the aggregation number of the surfactant are calculated. The partial molar volume binding constant, is discussed in terms of solubilization sites of the alcohol in the micelles whereas the binding constant is compared with that derived from the Nernstian partition const…
Calorimetric investigation of water/lecithin/cyclohexane microemulsions
1997
The enthalpies of dilution of water/lecithin/cyclohexane microemulsion-gels at variousR values (R=[water]/[lecithin]) and molar enthalpies of solution of water in lecithin/cyclohexane at a fixed lecithin concentration were determined calorimetrically at 25°C. Through a description of the process of dilution of water/lecithin/cyclohexane microemulsion-gels as one involving mainly the scission of lecithin reversed micelles in to smaller ones, the concentration dependence of the enthalpy was rationalized. Surprisingly, in order to account for the dilution enthalpies, it was not necessary to hypothesize a thermal effect arising from the breakage of the micellar network present in the micremulsi…
Aggregazione e centralizzazione della domanda pubblica di beni: stato dell'arte e proposte di migliorie al sistema vigente
2018
Il saggio esamina e discute le problematiche legate al sistema centralizzato degli acquisti nell’ambito degli appalti pubblici. Un tale sistema si basa su una pluralità di centrali di committenza e soggetti aggregatori operanti sia a livello statale sia locale. Attraverso un’analisi del quadro normativo vigente viene evidenziato come questo pluralismo accentuato metta a repentaglio il raggiungimento degli obiettivi che il sistema persegue, in primo luogo la revisione della spesa. Muovendo da tale profilo problematico il saggio propone alcune modifiche alla normativa mirate a rendere il sistema più razionale ed efficiente. Aggregation and centralization of the purchase of goods and services:…
Aggregation of albumin: influence of the protein glycation
2011
Free radicals are a normal component of cellular oxygen metabolism in mammals. However, free radical-associated damage is an important factor in many pathological processes. Aggregation, glycation and oxidative damage cause protein modifications, frequently observed in numerous diseases. Albumin represents the most abundant circulating protein. Many epidemiological studies have established an inverse relationship between the level of serum albumin and the risk of death. Albumin is involved in several biological functions, including the regulation of oncotic pressure, and the binding and transport of many molecules. In addition, albumin displays potent antioxidant and free radical scavenging…
Nucleation mechanisms and morphologies in insulin amyloid fibril formation
2011
Thermal aggregation of BSA in trehalose or saccharose solutions
2012
Supramolecular systems based on gold(I) derivatives : molecular recognition of L-glutamine and polyQ
2017
L-glutamiinin ja polyglutamiinin molekyylintunnistuksessa käytettyjen uusien organometallikompleksien mielenkiintoiset luminesoivat ominaisuudet ovat peräisin 4-etynyylianiliiniligandista ja fosfaaniyksiköstä sekä molekyylien välisistä Au⋯Au vuorovaikutuksista. Heikkojen intermolekulaaristen vuorovaikutusten on havaittu johtavan kuitu- ja pallomaisten muotojen morfologisiin muutoksiin vierasmolekyylien läsnä ollessa. Muodostunut isäntä-vieras -kompleksi tuottaa erilaisen emission vierasmolekyylistä riippuen. Lisäksi [Au(4-etynyylianiliini)(PTA)]:n itsejärjestäytymisen termodynaamisia funktioita tutkittiin eri pitoisuuksissa ja lämpötiloissa NMR mittausten avulla. Nämä lineaariset kulta(I) -…
Lysozyme Aggregation Driven by Unfolding: the Role of Metal Ions
2007
Electrocatalytic properties of ferrooctacarboxyphthalocyanine(II). Electrocatalytic oxygen reduction on the mercury electrode in aqueous solutions
1996
Electrocatalytic reduction of oxygen in aqueous solutions in the presence of ferrooctacarboxyphthalocyanine was investigated. The decay of catalytic properties is attributed to the phthalocyanine aggregation. The mechanism for the four-electron electrocatalytic O2-reduction in neutral and basic media involving FePc(COOH)8 is proposed. It has been found that monomers of phthalocyanine, which are able to form μ-peroxo structures, are the catalytically active forms. The adsorption of various phthalocyanine forms on the mercury electrode plays a very important role in the overall catalytic reaction.
Spectral properties and aggregation of ferrooctacarboxyphthalocyanine(II) in aqueous solutions
1996
Spectral properties of ferrooctacarboxyphthalocyanine(II) in aqueous solutions are discussed. A special attention is paid to aggregation in the presence of electrolytes. The influence of many factors (concentration, pH etc.) on forms of its occurence is presented.