Cotton fiber quality characterization with light scattering and fourier transform infrared techniques.

Fiber quality measurement is critical to assessing the value of a bale of cotton for various textile purposes. An instrument that could measure numerous cotton quality properties by optical means could be made simpler and faster than current fiber quality measurement instruments, and it might be more amenable to on-line measurement at processing facilities. To that end, a laser system was used to investigate cotton fiber samples with respect to electromagnetic scattering at various wavelengths, polarization angles, and scattering angles. A Fourier transform infrared (FT-IR) instrument was also used to investigate the transmission of electromagnetic energy at various mid-infrared wavelengths. Cotton samples were selected to represent a wide range of micronaire values. Varying the wavelength of the laser at a fixed polarization resulted in little variation in scattered light among the cotton samples. However, varying the polarization at a fixed wavelength produced notable variation, indicating that polarization might be used to differentiate among cotton samples with respect to certain fiber properties. The FT-IR data in the 12 to 22 microm range produced relatively large differences in the amount of scattered light among all samples, and FT-IR data at certain combinations of fixed wavelengths were highly linearly related to certain measures of cotton quality including micronaire.

Description of three new species of Encyrtidae Walker (Hymenoptera: Chalcidoidea) from India.

Three new species of Encyrtidae are described from material collected from the states of Karnataka and Tamil Nadu, India-Bureshiella antennata sp. nov., Proleurocerus montanus sp. nov. and Pseudectroma annamalaicus sp. nov. Keys to the species of all the three genera are provided and Bureshiella Hoffer is reported for the first time from India.

Description of three new species of Pentelicus Howard (Hymenoptera: Encyrtidae) from India, with a key to world species.

Three new species of Pentelicus Howard (Hymenoptera: Encyrtidae) are described from Tamil Nadu, India: P. funiculatus sp. nov., P. punctatus sp. nov. and P. depunctatus sp. nov. A revised key to the world species of Pentelicus is also provided.

Stephanocampta Mathot (Hymenoptera: Mymaridae): descriptions of two new species and the female of S. indica Anwar & Zeya from India and a key to world taxa.

Two new species of Stephanocampta Mathot (Hymenoptera: Mymaridae), S. andamanensis sp. nov. and S. huberi sp. nov., are described from Andaman Islands (Andaman and Nicobar Islands Union Territory) and Manipur, India. The previously unknown female of S. indica Anwar & Zeya is described. A revised key to the world species of Stephanocampta is provided. Stephanocampta serenellae Viggiani stat. rev. is transferred back to Camptoptera Förster, based on examination of the holotype male from Sri Lanka.

Characterization of colloidal hematite particle shape and dispersion behavior.

An elliptically polarized light scattering (EPLS) technique for the size and shape characterization of ellipsoidal hematite particles is presented. The hematite particles are synthesized by aging aqueous FeCl(3) or Fe(NO(3))(3) solutions at 100 degrees C. Different reaction conditions create particles of aspect ratios between 1 (spherical) and 8 (elongated). Cross-sectional diameter and aspect ratio are observed as a function of reaction (aging) time. Growth of the elongated particles, as well as their fractal aggregation behavior, is characterized using EPLS and comparisons are made with photon correlation spectroscopy and TEM measurements.

Scattering matrix elements of fractal-like soot agglomerates.

The possibility of measuring scattering-matrix (Mueller matrix) elements of soot agglomerates with laser diagnostic techniques is explored. To show this, we calculated the scattering-matrix elements of arbitrary-shaped soot agglomerates. The sensitivity of scattering-matrix elements to optical and morphological characteristics of fractal-like soot agglomerates is discussed. Finally, possible measurement techniques are suggested to identify soot structures from scattering-matrix elements.

Scattering-matrix elements of coated infinite-length cylinders.

The angular variations of scattering-matrix elements of coated cylindrical particles are presented. The sensitivity of different elements for a number of physical parameters are discussed, including size parameter, real and imaginary parts of the refractive index of the outer coat, and the inner core. The numerical predictions are presented for typical index-of-refraction values of cotton fibers. These results show that the physical structure of coated cylinders can be determined from carefully conducted light-scattering experiments.