Browsing by Subject "nucleation"

Now showing 1 - 4 of 4

Access status: Open Access ,
Apparatus to study volumetric properties of the gas hydrates
(2012) Lorenc, Maciej; Warowny, Witold
A new pVT apparatus was built on Department of Drilling, Oil and Gas at AGH University of Science and Technology, which was sponsored by the Polish Oil and Gas Company. The apparatus was adjusted to measurement of the proprieties of the gas hydrates. On the schematic diagram of this apparatus, methodological solutions of the equipment were compared to different of this kind literature apparatuses. Among others innovatory elements of the present apparatus some of them should be counted: method of the changes of volume or automatic system (arrangement) to taking the sample with supported nafion drying. The first step of the experimental study is desulfurization of the natural, by using process of the hydrates formation in gas mixture.
Access status: Open Access ,
Comparative studies of the electroreduction of zinc ions from gluconate solutions
(Wydawnictwa AGH, 2019) Rudnik, Ewa; Chat-Wilk, Karolina
This study considers the role of chloride and sulphate anions in the cathodic reduction of zinc ions from gluconate solutions (chloride, sulphate, chloride-sulphate). Cyclic potentiodynamic and potentiostatic polarization measurements, as well as chronoamperometric experiments, were performed. Electrochemical results were correlated with the speciation of the baths. The experiments revealed the inhibiting effect of sulphate ions on the cathodic process caused by the formation of stable neutral ZnSO4 complex in the sulphate-gluconate bath. It resulted in zinc deposition under a limiting current, with the release of metal cation as a rate-determining step. The less stable ZnGlu+ complex dominated both chloride-containing baths, thus the metal deposition ran under activation control. Independent of the solution composition, the nucleation of zinc occurred according to the instantaneous model.
Access status: Open Access ,
Doświadczalne metody badań hydratów gazowych
(2011) Lorenc, Maciej; Warowny, Witold
Knowledge of the nature gas hydrates is connected mainly with experimental studies in laboratory and pilot plant and theory supported by calculations and computer simulations. In work have been given methods of measurement dealing with: formation and/or prevention of formation gas hydrates, studies their properties, and utilization in new technologies. Generally, studies of the gas hydrates and hydratation can be divided on several thematic groups: experimental and calculated determination of phase equilibrium, studies of the physicochemical and structural parameters, kinetic measurements, including nucleation, and agglomeration of particles, studies influence of inhibitors and surfactants on the hydratation process, possibility of technological applications, especially hydrate of methane, including getting out, transport, storage and purification, plus geological and geophysical studies carried out in order to estimation methane hydrate deposits. KEYWORDS: hydrate, clathrate, methane, experimental, nucleation, nonstoichiometric, inhibitor, Van der Waals bond, hydrogen bond, crystalline.
Access status: Restricted ,
Wpływ kwasu glukonowego na rozpuszczalność piromorfitu
(Data obrony: 2013-09-13) Borowicz, Paweł
Wydział Geologii, Geofizyki i Ochrony Środowiska
Phosphate-induced lead immobilization method is based on the fact that newly formed mineral, pyromorphite, is a highly insoluble phase. However, there is a number of factors capable of decreasing stability of pyromorphite. Among them are low-molecular-weight organic acids (LMWOA) secreted to the soil by numerous species of microorganisms and plants. Presented studies investigate the relation between pyromorphite and gluconic acid (GA), one of the most common LMWOA in the soil. The conducted experiments includes dissolution of pyromorphite in the presence of GA, having regard to the pH of the solution or concentration of GA, and formation of pyromorphite in the presence of GA (homogeneous and heterogeneous transformations). The studies indicate that GA increase the dissolution of pyromorphite through decreasing pH of the solution, Pb-organic complexation and increasing the ionic strength of the solution. GA inhibits growth of pyromorphite crystals through formation of complexes with crystal seeds and reducing activity coefficient of lead cations.