Microparticle analysis

Infrared microscopes can focus the beam down to a 20-pm spot size for microprobing in either the transmission or reflection mode. Trace analysis, microparticle analysis, and spatial profiling can be performed routinely. 

Assuming that solid-state electrochemical processes involved in our voltammetry of microparticles analysis satisfy Tafel dependence between current and potential at the rising portion of voltammetric curves, the current can be approached by the expression... 

Laboratory for Microparticle Analysis, Moscow, Russian Federation SIMS ... 

It was observed that this technique was able to produce microparticles with a mean diameter of approximately 10.17 + 3.02 pm in a reasonable to satisfactory yield depending on the formulation. This value was observed to be higher for the polymer weight ratio of 1 3 (87.00 + 4.25 %), which indicates that ESIOO improves the final result of the spray-drying process. According to the SEM analysis, the polymeric microparticles were shown to be quite similar in shape. Regardless of the formulation, they appeared to be mostly concave and asymmetric (Figure 12). 

Figure 7.1 The principle of thermodynamic analysis for the measurement ofthree-dimensional potentials exerted on a single microparticle.

Sasaki, K., Tsukima, M. and Masuhara, H. (1997) Three-dimensional potential analysis of radiation pressure exerted on a single microparticle. Appl. Phys. Lett., 71, 37-39. 

Matsuo, Y, Takasaki, H., Hotta, J. and Sasaki, K. (2001) Absorption analysis of a single microparticle by optical force measurement./. Appl. Phys., 89,5438-5441. 

BD Barr-Howell, NA Peppas. Structural analysis of poly(2-hydroxyethyl methacrylate) microparticles. Eur Polym J 23 591-596, 1987. 

Kitamura, N. Kitagawa, F., Optical trapping chemical analysis of single microparticles in solution, J. Photochem. Photobiol. C Photochem. Rev. 2003, 4, 227 247... 

Nolan J, Mandy F (2006) Multiplexed and microparticle-based analyses. Quantitative tools for the large-scale analysis of biological systems. Cytometry A 69 318-325... 

Mikos A., and Peppas, N.A., Bioadhesive analysis of eontrolled-release systems. IV. An experimental method for testing the adhesion of microparticles with mucus, J. Control. Rel, 12 31-37 (1990). 

Thus, provided that one takes into account the effects of morphological resonances on the Raman spectra of microspheres, it appears that qualitative and quantitative chemical analysis of microparticles can be achieved. 

Resonant and non-resonant laser post-ionization of sputtered uranium atoms using SIRIS (sputtered initited resonance ionization spectroscopy) and SNMS (secondary neutral mass spectrometry) in one instrument for the characterization of sub-pm sized single microparticles was suggested by Erdmann et al.94 Resonant ionization mass spectrometry allows a selective and sensitive isotope analysis without isobaric interferences as demonstrated for the ultratrace analysis of plutonium from bulk samples.94 Unfortunately, no instrumental equipment combining both techniques is commercially available. 

The utility of ANNs as a pattern recognition technique in the field of microbeam analysis was demonstrated by Ro and Linton [99]. Back-propagation neural networks were applied to laser microprobe mass spectra (LAMMS) to determine interparticle variations in molecular components. Selforganizing feature maps (Kohonen neural networks) were employed to extract information on molecular distributions within environmental microparticles imaged in cross-section using SIMS. 

This application was motivated by the potential for exploiting the LMI source s rich selection of ions and microparticles to investigate secondary ionization processes, the possibility of improving sensitivity, and the more remote prospect of achieving localized, molecular analysis of biological tissues with a finely focused ion beam. 

Representative Protocols of Analysis of Endothelial Microparticles Used in Clinical Studies... 

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