Spectral refractive index technique for monitoring the beer mashing process.

During beer production, the mashing process is fundamental for extraction of the main sugars from the starch. The quantification of these fermentable sugars during the process provides a measure of the alcoholic content of the final beer. Therefore, monitoring of the sugar composition during beer production is very important for obtaining a quality product. This paper demonstrates the potential of white light interferometry (WLI) for monitoring the extraction of sugars in different mashing processes, by observing the refractive index of the mixture. All the mashings presented linear increases of the refractive index during the temperature steps, which were influenced by the concentrations of sugars produced in each step. Cauchy parameters obtained by refractive index interpretation showed the influence of carbohydrates on absorption in the infrared region, and amino acids on absorption in the ultraviolet region. Strong correlation was obtained between the refractive index and °Bx values, indicating that the WLI technique is a potential analytical method for monitoring the mashing process during beer production.

Measurements of refractive indices and thermo-optical coefficients using a white-light Michelson interferometer.

A dispersive white-light Michelson interferometer was used to determine the wavelength dependence of the refractive index (n) in the visible range from 425 to 775 nm and the thermo-optical coefficient (dn/dT) of fused silica (FS) and borosilicate glass (BK7). For FS, the values obtained for n and dn/dT at 546 nm were 1.46079 and 11.3×10-6 K-1, respectively, while the values for BK7 glass were 1.51825 and 2.2×10-6 K-1, respectively, which is in good agreement with the literature. The accuracy of the methodology used for n was almost 10-6, enabling precise spectroscopic characterization of materials across a wide spectral range.

Tunable color temperature of Ce3+/Eu2+, 3+ co-doped low silica aluminosilicate glasses for white lighting.

In this paper we report results of tunable lighting in Ce(3+)/Eu(2+,3+) doped low silica calcium aluminosilicate glass. Optical spectroscopy experiments indicate that there is a red color compensation from Eu(2+) and Eu(3+) to the green emission from Ce(3+), resulting in a broad and tunable emission spectra depending on the excitation wavelength. This result analysed in the CIE 1976 color diagram shows a close distance from the Plank emission and a correlated color temperature, varying from 5200 to 3500K. This indicates that our system can be easily excited by GaN based blue LEDs, being an interesting phosphor for white lighting devices.

Radioguided occult lesion localization (ROLL) and excision of breast lesions using technetium-99m-macroaggregate albumin and air injection control.

The aim of this study was to assess the efficiency of the radioguided localization and excision technique using radiopharmaceuticals injected directly or close to occult breast lesions. We studied thirty-two consecutive patients with thirty-six occult breast lesions detected mammographically or ultrasonically categorized as BI-RADS 3, 4 or 5. Macroaggregate Albumin (MAA) labeled with (99m)Tc was administered directly or close to the lesion, guided by mammography or ultrasound, followed by an air injection for radiological control. The excision biopsy was carried out with the aid of a hand-held gamma detecting probe and the entire removal of the lesion was verified by X-ray of the surgical specimens or by intraoperatory frozen section examination. Breast cancer was found in 8.3% of BI-RADS 3 lesions, in 33.3% of the BI-RADS 4 lesions and in 66.6% of the BI-RADS 5 lesions. The radiotracer was correctly positioned in 97.2% of the specimens (35/36) allowing the removal of 97.2%. Xray confirmed the entire removal in 27 lesions (75%), intraoperatory frozen section study in 19.4% (7/36) and by both methods in 5.5% (2/36). Radioguided surgery turned out to be an important tool in the removal of non-palpable breast lesions, as a simple, fast and feasible method that can be implemented in the clinical routine of patients with non-palpable breast lesions.