Untersuchungen zur Reaktion von Pyrazolon-Azomethin-Farbstoffen mit 2-Pyrazolin-5-on-Derivaten

Investigations on the Reaction of Pyrazolone Azomethine Dyes with 2-Pyrazolin-5-one-Derivatives The reaction between pyrazolone azomethine dyes 1 and different 2-pyrazolin-5-ones 2 was investigated. Among the reaction products compounds 5 {3,3′3″-trimethyl-1,1′1″-triphenyl-[4,4′4″-tri-(2-pyrazolin-5-on)]} was isolated, which hitherto was unknown as a product of this reaction. A new reaction pathway is proposed.     

Use of Sorbent-Based Vacuum Extraction for Determination of Volatile Phenols in Beer

A novel method based on vacuum-assisted sorbent extraction (VASE) used with gas chromatography-mass spectrometry (GC-MS) for isolation of volatile phenols was described. The method is based on extraction of analytes into sorbent traps (sorbent pen) filled with Tenax in a vacuum system—vials with traps from which air was evaluated. The method was applied for extraction of volatile phenols from aqueous matrix and smoked beer was used as a food example. Methyl-, dimethyl-, and trimethylphenols, along with 4-ethylphenol, 4-methylguaiacol, 4-ethylguaiacol, 4-propylguaiacol, and eugenol, were used in method development. Optimal extraction parameters were elaborated. For the analysis of volatile phenols in beer matrix, the method was characterized with satisfactory linearity (r²?≥?0.99) in a range of 0.005–0.5 mg/L. Limits of detection (LODs) for analyzed compounds ranged from 0.0006 to 0.018 mg/L and repeatability for majority of compounds was <?5% for a single trap extraction. The detected volatile phenols in beer samples ranged from 0.003 to 0.672 mg/L.     

Untersuchungen zur Reaktion von Pyrazolonazomethin-Farbstoffen mit 2-Pyrazolin-5-on

Investigation of Reactions of Pyrazolin-Azomethin Dyes with 2-Pyrazolin-5-one The pyrazolin-azomethin dyes ( 3a – d ) from 1-phenyl-3-methyl-2-pyrazolin-5-one and various photographic developers have been obtained. The reactions of decolourization of dyes during the 3-methyl-1-phenyl-2-pyrazolin-5-one action was investigated. We ascertained that the substituent changes in the developer had not only the influence on decolourization rate but they also had influence on the order change of the reaction. The various solvents had the same influence on the reaction rate of decolourization.     

Inhalation dose due to presence of 131I in air above septic tank system of an endocrinology hospital

We present here measurements of the 131I concentration for both: gaseous and aerosol fraction of 131I in the air above the septic tank containing wastes from medical application of this isotope. Aerosols were collected using air filters, whereas gaseous forms of iodine were trapped in KI impregnated charcoal double layer cartridge. Besides an active method (pumping of the air through system of filters) an attempt for using a passive method (charcoal traps) for monitoring of radio-iodine is described. For better characterisation of a site the external kerma was determined by means of G-M and TLD techniques as well as the activity kept in the septic tank was measured by gamma spectrometry. Results show that the activity of the aerosol fraction can be neglected compared to that of the gaseous fraction. He measured activity of air is low, on the level of 1 Bq m(-3), even during simulated failure of the ventilation system. Estimated inhalation dose for the serviceman of septic tanks is low ( approximately 10%) compared with external dose obtained by such person due to gamma radiation from the tank (on the level approximately 500 nSv h(-1)). Therefore, the concept of passive monitoring of the iodine in air was abandoned. Also estimated is the efficiency of 131I reduction by a charcoal filter of the ventilation system and 131I input to the environment by the ventilation chimney.     

Structural analysis of distributed Bragg reflector mirrors

Quantum cascade (QC) lasers and vertical-cavity surface-emitting lasers (VCSELs) are of great interest due to their potential importance for a variety of device applications. Both kinds of lasers call for very highly reflective mirrors. Usually distributed Bragg reflector (DBR) mirrors, which consist of periodic quarter wavelength stacks of high and low refractive index compound semiconductors are used. These stacks are superlattices containing more than 40 individual layers. To obtain very high reflectivity DBRs alternating GaAs and AlAs layers are used for both the high and low index mirrors.GaAs/AlAs DBR structures containing 15 periods were characterized by the complementary use of RBS/channeling, TEM and HRXRD. Since the total thickness of a DBR exceeds 2 μm the RBS analysis was performed at two He-ion energies: 1.7 MeV and 3.82 MeV. After some stopping power corrections TEM and RBS provided similar results. Discrepancies with HRXRD data were attributed to the lateral inhomogeneity of produced superlattice. Virtues and pitfalls of complementary use of these techniques were discussed.     

Determination of volatile compounds in Baijiu using simultaneous chromatographic analysis on two columns

Baijiu is a Chinese spirit which is produced by a complex process involving solid state fermentation with various raw materials and a consortium of microorganisms resulting in an abundance of fermentation by products. A method was developed for quantification of 62 compounds in Baijiu spirits using simultaneous direct injection to two columns (CPWax-57CB and DB-624). Dual column analysis substantially increased the reliability of identification using a flame ionisation detector. The method had high linearity - for all but one compound - indicated by the coefficient of determination (R²) of ≥ 0.999 (in a range of 0.3 – 260 mg/L) and reproducibility (for the majority of compounds at a concentration of ca. 1 mg/L, < 5% for the DB-624 columns and < 8% for the CPWax-57CB column). The limit of detection was < 1 mg/L for all compounds. The method was used to analyse volatile compounds in 38 samples of Baijiu, from different regions and flavour types. The main group of compounds in the volatile fraction were esters and higher alcohols. Based on Orthogonal Partial Least Squares Discriminant Analysis it was not possible to separate the samples in terms of region, but it was possible to distinguish between strong and soy sauce types of Baijiu from the other samples. © 2020 The Institute of Brewing & Distilling     

Insights on boron impact on structural characteristics in epitaxially grown BGaN

Journal of Materials Science - It is shown that MOCVD growth allows to obtain BGaN epitaxial layers at growth temperature (Tgr) between 840 and 1090&nbsp;°C. It is found that morphology of...     

Eimeria coecicola Cheissin 1947: endogenous development in gut-associated lymphoid tissue

Coccidia-free rabbits were inoculated with different doses of a pure strain of Eimeria coecicola and samples of gut were taken at 80, 96, 112, 128, 144, and 160 h postinoculation. The use of a very low infective dose (2-20 oocysts) was sufficient to study the last merogony. The number of merozoites in meronts increased when the infective dose decreased. Only the first merogony of this coccidium in lymphocytes or M-cells of gut-associated lymphoid tissue (GALT) has previously been described. Three other generations of meronts are described herein. All these endogenous stages were observed in the epithelium of the vermiform appendix, sacculus rotundus, and Peyer's patches, especially at the bases of the domes. However, in heavily infected tissues the gamonts were seen throughout the epithelium of the GALT. The third- and fourth-generation meronts were of two types. As in other eimerian species of the rabbit, type A meronts produced thick polynucleated merozoites, whereas type B meronts gave rise to large numbers of thin merozoites with one nucleus. Microgamonts were polynucleated and less numerous than macrogamonts. Type A meronts were also polynucleated and less numerous at the end of the merogony. Therefore, types A and B could correspond to a sexual phenotype differentiation occuring during the two asexual phases of multiplication.