Investigating the optical properties of polycrystalline AgCl(1-x)Br(x) (0≤x≤1) and Ag(0.95)Tl(0.05)Br(0.95)I(0.05) for IR engineering.
Using the Michelson technique we measured the refractive indices for the plane-parallel thin plates made of AgCl1-xBrx(0≤x≤1) and, to the best of our knowledge, for the first time for the Ag0.95Tl0.05Br0.95I0.05 plate, manufactured by hot embossing, at 632.8 nm. We recorded their absorption spectra within the range of 0.19-41.67 μm using UV-Vis spectrophotometry and Fourier transform infrared spectroscopy, which demonstrated that the increase of substituent silver bromide or thallium monoiodide mole fraction in the corresponding solid solution causes the optical density to grow. As the result it moves the transmission edges toward longer wavelengths, while slightly reducing the transmission peak.
MEASUREMENT OF REFRACTIVE INDEX USING A MICHELSON INTERFEROMETER
As a classic laboratory apparatus, Michelson interferometer has been widely used in optical field. Under the premise of not affecting its accuracy, the operational performance of the Michelson interferometer should be improved. The Michelson interferometer can be used for the measurement of refractive index. For reduce experimental sensitivity, the structure of the Michelson interferometer is improved. Experimental results are demonstrated. Keywords—Michelson interferometer, refractive index, measurement
Multivariate Calibration for the Determination of Analytes in Urine Using Mid-Infrared Attenuated Total Reflection Spectroscopy
The reagent-free multicomponent analysis of components in urine using mid-infrared spectroscopy possesses many attractions. A population of 67 individual urine samples from children and adults, collected over 24 h, was analyzed for urea, creatinine, uric acid, glucose, total protein, phosphate, and sulfate by using clinical reference methodology. The urine pH value was potentiometrically measured by a glass electrode. Partial least-squares (PLS) calibration models were calculated over optimized, component-specific ranges from attenuated total reflection spectra of the urine samples measured by a micro-Circle cell. Apart from glucose and total protein, for which the spread in urine sample concentrations was too small, calibrations were successful for metabolites such as urea, creatinine, and uric acid. Additionally, concentrations of sulfate and phosphate anions, which show significant mid-infrared absorption bands, could also be quantified. The acid secreted with the urine influences the equilibrium between di- and monobasic phosphate in this biofluid, which is used as the spectroscopic basis for the pH assay presented here. The analytical performance of the reference methods is discussed with regard to evaluating the limitations of the spectroscopic assay. Additionally, aqueous solutions of individual urine components with a spread of concentrations similar to those found in native urine samples were analyzed by using PLS calibrations.