Wyniki wyszukiwania - BazTech

1

The effect of rheology with gas bubbles on linear elastic waves in fluid-saturated granular media

ALI A. A., Strunin D. V.

International Journal of Applied Mechanics and Engineering

|

2018

|

Vol. 23, no. 3

575--594

EN

Elastic waves in fluid-saturated granular media depend on the grain rheology, which can be complicated by the presence of gas bubbles. We investigated the effect of the bubble dynamics and their role in rheological scheme, on the linear Frenkel-Biot waves of P1 type. For the wave with the bubbles the scheme consists of three segments representing the solid continuum, fluid continuum and bubbles surrounded by the fluid. We derived the Nikolaevskiy-type equation describing the velocity of the solid matrix in the moving reference system. The equation is linearized to yield the decay rate λ as a function of the wave number k. We compared the λ (k) -dependence for the cases with and without the bubbles, using typical values of the input mechanical parameters. For both the cases, the λ(k) curve lies entirely below zero, which implies a global decay of the wave. We found that the increase of the radius of the bubbles leads to a faster decay, while the increase in the number of the bubbles leads to slower decay of the wave.

2

Silicone nanostructures

Kępczyński M., Kuźmicz D., Romek M., Nowakowska M.

Polish Journal of Applied Chemistry

|

2009

|

Vol. 53, nr 1

37-42

EN

Polysiloxane with covalently attached undecanoic acid groups was obtained in a two-step synthesis. Four molecules of methyl undec-10-enoate were attached to 1,3,5,7-tetramethylcyclotetrasiloxane (D4H) by hydrosilylation reaction yielding a new monomer, tetra(l 1-methoxy-l l-oxoundecyl)tetramethyl-cyclotetrasiloxane . The monomer was polymerized using anionic ring opening polymerization with concomitant hydrolysis of ester bonds. The silicone polymer thus obtained can self-organize in aqueous environment forming large objects, probably vesicles, with diameter of 1 pm. Silicon nanocapsules of controlled size can be prepared in a simple way in the polymerization processes of Dj""1*"'1 within vesicle templates. The monomer swells the surfactant vesicles up to 50 mol % based on the surfactant. Polymerization of D4"IK,"yl inside membrane yields nanocapsules of size similar to the originate vesicles.

3

Skale turbulencji i rozmiary pęcherzyków na początku samozasysania

Kurasiński T., Stelmach J.

Inżynieria Chemiczna i Procesowa

|

2004

|

T. 25, z. 3/2

1225-1230

PL

W pracy przedstawiono wyniki obliczeń charakterystycznych skal rozmiarowych turbulencji w mieszalniku z mieszadłem samozasysającym. Wyniki te porównano z określonymi metodą fotograficzną rozmiarami pęcherzyków przy częstościach obrotowych nieco większych od wartości krytycznej. Okazało się, że tylko przy niewielkim strumieniu gazu rozmiary pęcherzyków są zbliżone do skali Taylora.

EN

Results of calculations of characteristic length scales of turbulence in the mixer with a self-aspirating impeller are presented in the paper. The results were compared with bubble size determined by a photographic method at rotations frequency only slightly bigger than the critical value. It appeared that only at a small gas stream the bubble sizes are similar to the Taylor scale.

4

Otrzymywanie i zastosowanie liposomów

Gubernator J., Sokołowski A., Pawlak P.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

|

2000

|

Vol. 48, nr 22

265-268

PL

W pracy przedstawiono charakterystykę liposomów, metody ich otrzymywania, właściwości powstających związków, sposoby ich stabilizacji, a także zastosowanie w różnych dziedzinach nauki i techniki

EN

In this work we presented preparation methods, properties, stabilization methods and application of liposomes vesicles.