Low angle scattering

To illustrate this problem, we note a possible difference between the surface area of a porous solid which is available for adsorption and the area (including that of closed pores) which can scatter low angle X-rays. Even in the former case, the extent of the adsorption is likely to be dependent on the size, shape and electronic nature of the adsorptive molecules in relation to the surface chemistry, roughness and porosity of the adsorbent. 

The newer la.ser diffraction instrument allows measurement for particle sizes ranging from 0.1 pm to 8 mm (7). Most of the laser diffraction instruments in the pharmaceutical industry use the optical model based on several theories, either Fraunhofer, (near-) forward light scattering, low-angle laser light scattering, Mie, Fraunhofer approximation, or anomalous diffraction. These laser diffraction instruments assume that the particles measured are spherical. Hence, the instrument will convert the scattering pattern into an equivalent volume diameter. A typical laser diffraction instrument consists of a laser, a sample presentation system, and a series of detectors. 

Light-scattering low-angle, forward-scattering laser light source... 

Aqueous SEC of PVA Using On-Line Light Scattering Low-Angle Laser Light Scattering... 

Light scattering low angle right angle triple angle multi-angle... 

Characterization. When siHca gel is used as an adsorbent, the pore stmcture determines the gel adsorption capacity. Pores are characterized by specific surface area, specific pore volume (total volume of pores per gram of solid), average pore diameter, pore size distribution, and the degree to which entrance to larger pores is restricted by smaller pores. These parameters are derived from measuring vapor adsorption isotherms, mercury intmsion, low angle x-ray scattering, electron microscopy, gas permeabiHty, ion or molecule exclusion, or the volume of imbibed Hquid (1). 

Samples from size-exclusion chromatography/low angle laser light scattering (sec/laUs). 

Fig. 2. Histograms representing (a), the frequency of occurrence of platelets (PLT) and red blood cells (RBC) and illustrating coincidence where SL is low angle scatter, 2°C—3° and SH is high angle scatter, 5°C—15° (b), the volume of RBC, from 0 to 200 fL (c), the hemoglobin (HGB) concentration from 0 to...

In addition to polymer standards, a number of broad distribution, water-soluble polymers can be characterized on TSK-PW columns using universal calibration. These include both fully and partially hydrolyzed PVA, PAAM, PEE, and dextran. PVA, the world s largest-volume, synthetic, water-soluble polymer, was first successfully separated on TSK-PW columns by Hashimota et al. (10). In the 1980s, the use of low-angle, laser light-scattering detection... 

Measurements at low angles are subject to considerable error, and for this reason it is often preferred to apply appropriate corrections to scattering intensities measured at larger angles. The observed intensity ie in a direction 0 will be reduced on account of intraparticle interference by a factor cusomarily designated by P(0), which depends on the size and shape of the particle as well as on the angle 0. Thus, by definition... 

A number of the limitations of conventional SEC can be overcome through use of a low angle laser light scattering (LALLS) detector attached in series with a concentration... 

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