Synthesis of 9,10-Bis-hetaryl anthracenes and their application on polyester fibres as disperse dyes

9,10-Dibromoanthracene ( 2 ) obtained from anthracene by bromination was reacted with cuprous cyanide in refluxing DMF to obtain 9,10-dicyanoanthracene ( 3 ). The key intermediate ( 3 ) was condensed with orthophenylenediamine ( 4a ), ortho-aminophenol ( 4b ) and dicyanodiamine ( 6 ) to give 9,10-bis(benzimidazol-2-yl)anthracene ( 5a ), 9,10-bis(benzoxazol-2-yl)anthracene ( 5b ) and 9,10-bis(4,6-diamino-S-triazin-2-yl)anthracene ( 5c ), respectively. The spectral properties of 5a-5c were studied. These compounds, when applied as disperse dyes on polyester fibres, gave excellent results.     

Oxidative detoxification of aqueous bark extracts. Part II: Alternative methods

The most important problem associated with the high-pH autoxidative detoxification of methanogenic toxins in debarking wastewater was its limited application to the aqueous extractives of bark from specific species. The autoxidative polymerization of coniferous bark extracts exhausted prior to complete removal of the toxic oligomeric tannins. As a result, highly toxic spruce bark extracts were only partly detoxified. Birch bark extracts were not detoxified, even though effective polymerization of the oligomeric tannins occurred. The non-tannin toxins in birch bark extracts and toxic intermediates produced by high-pH autoxidation of these extracts were responsible for the poor detoxification results. These problems can potentially be resolved by applying alternative oxidation methods. In this study a high level of detoxification was obtained for all bark species tested by short-term destructive oxidations with H₂O₂, or by long-term aerobic biological treatments which caused high levels of polymerization. The applicability of high-pH autoxidation was also made feasible for all species of bark by applying a granular active carbon treatment after the autoxidation. The active carbon was able to adsorb the residual toxic oligomeric tannins of autoxidized spruce bark extracts and the non-tannin toxins in autoxidized birch bark extracts. Additionally, a potential disadvantage of the autoxidative detoxification method is the formation of colored end products. Although these compounds are non-toxic and are non-biodegradable, their elimination from the wastewater would be necessary if discharge norms concerning color and non-biodegradable COD must be fulfilled. The destructive oxidation with H₂ O₂ produced non-toxic low-molecular-weight compounds which did not have much color. The autoxidation and long-term aerobic biological treatments produced highly colored humic end products which could be eliminated by calcium precipitation.     

Study of local environment of Ag in Ag/CeO2 catalyst by EXAFS

The combustion synthesized Ag/CeO₂ catalysts have been characterized by Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy at the Ag K-edge. It has been found that Ag⁺ like species is present in 1% Ag/CeO₂ catalyst, whereas mostly Ag metal clusters are found in 3% Ag/CeO₂. The analysis of EXAFS spectra indicates that about one oxygen atom is coordinated to Ag central atom at a distance of 2.19 Å in 1% Ag/CeO₂ catalyst along with eight coordinated AgAg bond at 2.86 Å. The AgO bond is absent in 3% Ag/CeO₂.     

Consideration of the influence of aging process,type of wine and oenological classic parameters on the levels of wood volatile compounds present in red wines

The contents of the volatile compounds extracted from wood: cis- and trans-whiskylactones, vanillin, syringaldehyde, furfural, 5-methylfurfural, eugenol, guaiacol, p-ethyl-phenol and p-ethylguaicol have been studied in 12 single-variety wines aged in new American oak barrels. The concentration of these compounds were determined after the following combinations of time in wood and time in bottle: 0 months in wood plus 18 months in bottle, 4 months in wood  + 14 months in bottle, 9 months in wood + 9 moths in bottle and 12 months in wood + 6 months in bottle. According to the composition of the wines, it is possible to conclude in general, that, the extraction of these compounds was faster during the first four or 9 months of aging in wood, depending on the wines. After 12 months of oak maturation, the extraction of these compounds slowed down. Furthermore, the final concentrations of these volatile compounds were different among studied wines. These differences could be related to some of the values of some of their oenological parameters, such as the contents of tartaric acid and sulphur dioxide of each wine.     

Chemical Preparation and Shock Wave Compression of Carbon Nitride Precursors

Two synthetic routes have been developed to produce high-molecular-weight organic precursors containing a high weight fraction of nitrogen. One of the precursors is a pyrolysis residue of melamine-formaldehyde resin. The second precursor is the byproduct of an unusual low-temperature combustion reaction of tetrazole and its sodium salt. These precursors have been shock compressed under typical conditions for diamond and wurtzite boron nitride synthesis in an attempt to recover a new ultrahard carbon nitride. The recovered material has been analyzed by X-ray diffraction, FTIR, and Raman microprobe analysis. Diamond is present in the recovered material. This diamond is extraordinarily well ordered relative to diamond shock synthesized from carbonaceous starting materials.     

Influence of an adjunct culture of Lactobacillus on the free amino acids and volatile compounds in a Roncal-type ewe’s-milk cheese

Free amino acids and volatile compounds were analysed in a Roncal-type cheese made from pasteurized ovine milk with and without an added adjunct culture (Lactobacillus paracasei + Lactobacillus plantarum). In both batches, the total free amino acid concentration increased 11–12-fold with ripening time, the main amino acids being Leu, Glu, Lys, Phe, Val, and Ile. At the end of ripening, significant differences were recorded for Leu, Ile, Gaba, Phe, Pser, Ser, Gin, Ala, and Orn.     

Non-volatile taste active compounds in the meat of Chinese mitten crab (Eriocheir sinensis)

The non-volatile taste active compounds, including soluble sugars, succinic acid, free amino acids and flavour 5′-nucleotides in the meat of Chinese mitten crab (Eriocheir sinensis) were analyzed, and their taste impacts were evaluated by taste active values (TAVs) and equivalent umami concentration (EUC) methods. The total free amino acid content of crab meat was 20.9 mg/g. Arginine, glycine and alanine were the major free amino acids, accounting for more than 70% of the total free amino acids. 5′-Adenosine monophosphate (AMP) was the main flavour 5′-nucleotide (75.3 mg/100 g), followed by 5′-inosine monophosphate (IMP) (34.4 mg/100 g) and 5′-guanosine monophosphate (GMP) (2.3 mg/100 g). Arginine, glycine, alanine, glutamic acid, IMP and AMP were of high TAV (greater than one), and they had strong taste impacts on the crab meat flavour. Glycine and alanine contributed to the major sweet taste, while glutamic acid, IMP and AMP contributed to the strong umami taste. As the TAVs of soluble sugar, succinic acid and bitter free amino acids were lower than one, thus those compounds are likely to have insignificant impact on the taste of the crab meat. The EUC was 4.2 g MSG/100 g crab meat, which meant that the umami taste of the crab meat was very intense.     

Assessment of the Antioxidant Properties During Storage of a Dessert Made from Grape, Cherry, and Berries

A 1‐y storage trial was designed involving different temperatures (8, 21, and 30 °C) to assess the antioxidant properties of a dessert formulated with concentrated juices of grape, blackberry, blackcurrant, raspberry, and cherry. The total antioxidant activity (TAA) of the dessert was measured as the scavenging capacity of the 2,2′‐azino‐di‐[3‐ethylbenzothiazoline‐6‐sulphonate] radical cation (ABTS) and as its iron‐reducing ability (FRAP). Color was spectrophotometrically measured, and vitamin C and phenolics were analyzed by HPLC. The color parameters and the concentrations of different antioxidant compounds were affected by storage conditions, especially in samples stored at 30 °C, although the TAA remained practically invariable during storage.     

Production of volatile compounds in the fermentation of chardonnay musts inoculated with two strains of Saccharomyces cerevisiae with different nitrogen demands

This paper studies the behaviour of two strains of Saccharomyces cerevisiae with different nitrogen requirements in the production of esters and higher alcohols during alcoholic fermentation. To carry out the study a chardonnay must with a high content of nitrogen compounds was used. The results showed that the strain with the highest nitrogen demand produced a higher concentration of esters during fermentation and gave rise to a wine with a somewhat lesser content of higher alcohols. The formation of volatile compounds was probably related to the consumption of nitrogen by the strains as the nitrogen nutrients act as precursors in the synthesis of esters and alcohols and regulate their production.     

An analysis of intermetallics formation of gold and copper ball bonding on thermal aging

In IC packages, thermosonic wire bonding is the preferred method for making electrical connections between the die pad and lead frame. These interconnect are made using fine metal wires. On thermal aging (under 175 °C for 5 h) gold aluminide easily forms in gold ball bonds while formation of intermetallic compound is absent in case of copper ball bonds. An analysis of the atomic property of the elements bonded explains that atomic radii and electronegativity factors favor gold aluminide formation.