5,826 research outputs found
Peculiarities of spectra of induced emission of polymethine dye solutions at low temperatures
Results from studying the induced emission spectra with monochromatic excitation (superluminescent regime) within a temperature range of 300 K - 5.2 K are presented. The significant feature of such operations is the appearance of quasi-lines whose minimum width is realized at 4.2 K. The frequency distribution of the quasi-lines unambiguously characterizes the dye investigated. When interpreting these results, the idea of an inhomogeneous broadening of the polymethine dye spectra in the solution being studied experimentally was used for the first time. The quasi-lines observed are interpreted as a manifestation of the electron vibration structure of singlet states of a complex molecule
Crystals of Na+ ions at the surface of a silica hydrosol
I used x-ray grazing incidence diffraction to measure the spatial
correlations between sodium ions adsorbed with Bjerrum's density at the surface
of a monodispersed 22-nm-particle colloidal silica solution stabilized by NaOH
with a total bulk concentration mol/L. My findings show that the surface
compact layer is in a two-dimensional crystalline state (symmetry p2), with
four ions forming the unit cell and a ~30 Angstrom translational correlation
length between sodium ions.Comment: 13 pages, 4 figure
Condensation of Silica Nanoparticles on a Phospholipid Membrane
The structure of the transient layer at the interface between air and the
aqueous solution of silica nanoparticles with the size distribution of
particles that has been determined from small-angle scattering has been studied
by the X-ray reflectometry method. The reconstructed depth profile of the
polarizability of the substance indicates the presence of a structure
consisting of several layers of nanoparticles with the thickness that is more
than twice as large as the thickness of the previously described structure. The
adsorption of 1,2-distearoyl-sn-glycero-3-phosphocholine molecules at the
hydrosol/air interface is accompanied by the condensation of anion silica
nanoparticles at the interface. This phenomenon can be qualitatively explained
by the formation of the positive surface potential due to the penetration and
accumulation of Na+ cations in the phospholipid membrane.Comment: 7 pages, 5 figure
Harnessing the capabilities of spray granulation in the food industry for the production of functional foods
The article is the literature review of a current state of production technologies of powdery foodstuff, concentrates and multicomponent mixes. The need of the food industry for qualitative methods of processing of raw materials of different physical and chemical structure is noted. The authors give the reasons about need and possibility of a choice of granulation as a method of data processing of products. Physical and chemical features of granulation methods of disperse environments of various aggregate states based on the studied regularities and works of other authors are considered. The authors made the assumption of the application prospects of the method of liquid dispersion on the surface of particles in a suspended state for a granulation of foodstuff and they offered the alternative option. The possibility to use whey as binding element is considered. At the end of article authors draw the conclusion about the prospects of use of a method of dispersion of liquid on the surface of particles in a suspended state for a granulation of foodstuff
- …