• Bulletin of the Korean Chemical Society
• /
• v.27 no.3
• /
• pp.413-418
• /
• 2006

Sodium hyaluronate (NaHA), water soluble polymer having ultra-high molecular weight, is characterized by using on-line frit inlet asymmetrical flow field-flow fractionation (FI-AFlFFF) and multiangle light scattering (MALS). This study demonstrates the capability of power programming FI-AFlFFF for the separation of NaHA and the applicability of FI-AFlFFF with MALS for the characterization of molecular weight distribution and their structural information. Since sample injection and relaxation in FI-AFlFFF are achieved by using hydrodynamic relaxation, separation of high molecular weight polymers can be achieved smoothly without halting the separation flow. Experiments are carried out with the two different NaHA products (a raw NaHA sample and a thermally degraded NaHA product) and molecular weight distribution and conformations in solution are determined. Influence of sample filtration on the change of molecular weight distribution is also discussed.

• Journal of Biomedical Engineering Research
• /
• v.13 no.2
• /
• pp.141-146
• /
• 1992

The propagation, reflection and scattering characteristics of the near Infra-red lights were experimented in order to check the feasibility of non-restrained biotelemetry using indirect transmitted light. The results of the experiments show that 3 kinds of walls examined are not specular reflectors but almost perfect diffuse surfaces with slight directivity and that light in a local point is spread out and fills the room uniformly by repeating the reflection and scattering at walls, ceiling, floor. These results also explain the fact that the diffusely reflected light can be utilized as the carrier of biotelemetry even after several scattering and reflections.

• Journal of Pharmaceutical Investigation
• /
• v.17 no.1
• /
• pp.41-46
• /
• 1987

Oil in water microemulsion containing soybean oil and egg phosphatide was prepared by vacuum high shear mixing and high pressure homogenizing. The laser particle sizer, Coulter counter and photomicroscope were used to determine the particle size distribution at each cycle of homogenizing. Particularly, the laser particle sizer(dynamic light scattering method) was applied to the study of particle size distribution behavior below $1\;{\mu}m$. It was found that the particle size distribution below $1\;{\mu}m$ was shifted to lower size range as the number of passing cycle was increased. Beyond the 7th cycle, however, the particle size distribution was not varied.

• Korean Journal of Optics and Photonics
• /
• v.20 no.6
• /
• pp.366-374
• /
• 2009

An analytic solution is obtained for the problem of monochromatic light scattering by optically active, concentric double cylinders. The validity of the obtained solution is indirectly checked by comparing it with solutions already reported for some special cases. The solution can be used in the optical analysis of rod-shaped biological cells which possibly have optically active nuclei containing helically wound chromosomes.

• Journal of the Korean Chemical Society
• /
• v.17 no.4
• /
• pp.240-246
• /
• 1973

An analytic expression for the intensity of collision-induced light scattering obstained by introducing both short-range and long-range effects on the induced anisotropy. By taking argon as a specific example, it is shown that a narrow band at small frequency shifts is caused by long-range effects, while a broad band in the far wing of the spectrum is due to short-range effects. The overall intensity is a synthesis of these two bands and does not follow a simple exponential form. As temperature increases, the intensity at large frequency shifts increases makedly, while at small frequency shifts it changes little.

• Korea-Australia Rheology Journal
• /
• v.12 no.1
• /
• pp.69-76
• /
• 2000

We have derived the translation diffusion coefficient and the intrinsic viscosity formula adopting the Kholodenko's theory using 3＋1 dimensional Dirac propagator in the Kirkwood and Riseman scheme. We also performed static light scattering experiments and intrinsic viscosity measurement of dilute solutions of polyimides with different rigidities. In the framework of Kholodenko's theory, we can easily measure the persistence length of polyimide. We prepared five different polyamic acids and polyimides with different degree of imidization by controlling imidization temperatures. From experimental results, we obtained molecular weights and persistence lengths according to the Kholodenko's plot. The molecular weight and the intrinsic viscosity decreased and then increased with the imidization temperature but the persistence length increased monotonically and then leveled off. The persistence lengths calculated from intrinsic viscosities showed very good agreement with those from light scattering experiments.

• Korean Journal of Optics and Photonics
• /
• v.3 no.3
• /
• pp.167-171
• /
• 1992

We present the static and dynamic light scattering results of the salt induced restructured colloidal silica aggregates. We also report the results from the transmission electron micrographs which confirms the individual sizes of the particles and the local structure of the ramified aggregates. The fractal dimensions of the restructuring silica aggregates are considerably different with in-situ light scattering measurements. The measured fractal dimensions, $D_{F}$, is 2.21 for the 0.5 wt.% concentration of the salt induced Ludox-AM. The Rayleigh linewidth for 0.1 wt.% concentration of Ludox-AM is discussed.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.201-202
• /
• 2023

Now, there are many cases where materials are maintained at construction sites or standard construction prices are not in accordance with the applicable regulations, resulting in a lot of fine dust. Therefore, a particulate matter measurement system is applied not only to manage particulate matter at construction sites but also to reduce particulate matter .This study aims to evaluate the applicability of this particulate matter measurement system to the construction site through long-term measurement experiments using a light scattering method particulate matter measurement instrument at the construction site.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.5
• /
• pp.606-613
• /
• 2011

In this paper, patterns of laser scattering and detection of micro defects have been investigated based on Rayleigh criterion for silicon wafer in solar cell. Also, a new laser scattering mechanism is designed using characteristics of light scattering against silicon wafer surfaces. Its parameters are to be optimally selected to obtain effective and featured patterns of laser scattering. The optimal parametric ranges of laser scattering are determined using the mean intensity of laser scattering. Scattering patterns of micro defects are investigated at the extracted parameter region. Among a lot of pattern features, both maximum connected area and number of connected component in patterns of laser scattering are regarded as the important information for detecting micro defects. Their usefulness is verified in the experiment.

• Korean Journal of Optics and Photonics
• /
• v.20 no.6
• /
• pp.375-380
• /
• 2009

The scattering of a normally incident monochromatic light by optically active concentric double cylinders is studied by using a numerical method. A numerical code is developed on the basis of the analytical solutions, and the angular distributions of the intensity and the polarization of the scattered light are computed for some specific cases. The numerical code can be used to non-invasively determine the size, structure, and composition of a double cylinder with high accuracy by measuring the angular distribution of the scattered light by an experiment.