The photochemical behaviour of naphthoylenebenzimidazolone dyes in 1-methyl-2-pyrrolidone

The photochemical behaviour of selected naphthoylenebenzimidazolone dyes is discussed in terms of the photobleaching of the dyes in the presence of electron donors (phenylthioacetic acid, N-phenylglycine, ethyl 4-N,N-dimethylaminobenzoate) as well as an electron acceptor (1-methoxy-4-phenylpyridinium tetrafluoroborate) that are used in photoredox systems for light-induced polymerization. The fluorescence quenching of the dyes in the presence of the electron donors and the electron acceptor was also examined.     

Methods of assessing the time efficiency in the virtual measurement systems

The paper presents the analysis of the time measurement methods in the virtual instrumentation. Problem of the software operations time efficiency assessment is presented. Different methods and functions of the time measurement in the integrated programming environments are discussed. Experiments using the exemplary virtual instrument are conducted to reveal the advantages and disadvantages of particular time measurement methods. Both general purpose and Real-Time operating systems are considered. Experiments cover personal computers, and specialized systems, such as CompactRIO. Conclusions include the analysis of the possible approaches to the time-efficient instrument design and future applications of the presented methods.     

Effect of cultivar and fruit storage on basic composition of clear and cloudy pear juices

BackgroundPears due to low acidity are a suitable raw material for the production of multifruit nectars thus it is justified to determine the chemical composition and investigate the effect of cultivar and fruit maturity on juices quality.MethodsJuices from ‘Alexander Lucas’ and ‘Conference’ cultivars were produced after harvest and after 3 months of pears storage.ResultsAverage yield of clear juices was 76.4% for ‘Conference’ cultivar and 74.3% for ‘Alexander Lucas’. In the case of cloudy juices, the yield was lower by about 3%. Processing of ‘Conference’ cv. from stored fruit resulted in yield decrease compared to fruits after harvest; this was not in case of ‘Alexander Lucas’ in 2008, where juices produced from stored fruits were characterized by a higher yield compared to fresh fruit.Total solids content in clear juices was 125–135 g/L and 135–141 g/L for cloudy juices. ABTS^●+ and total phenolics analysis showed that cloudy juices were characterized by a higher antioxidant activity and phenolics content than the clear ones.ConclusionPear storage, on the contrary to apples, does not decrease their suitability for cloudy juice production. Cloudy juices as a rule have higher antioxidant activity than the clear ones.     

Controlled mechanochemical synthesis and properties of a selected perovskite-type electroceramics

This paper presents mechanochemical synthesis as an alternative to the traditional high-temperature synthesis of advanced electrotechnical ceramic materials with a perovskite-type structure. The reaction conditions for high-energy ball milling, e.g. reaction environment, energy of milling and additives to BaTiO₃ such as metallic iron or zirconia from the exfoliation of the milling vessel and grinding media are discussed.     

The virtual distortion method—a versatile reanalysis tool for structures and systems

For 20 years of development, the virtual distortion method (VDM) has proved to be a versatile reanalysis tool in various applications, including structures and truss-like systems. This article presents a summary of principal achievements, demonstrating the capabilities of the VDM both in statics and dynamics, in linear and nonlinear analysis. The major advantage of VDM is its exactness and no need for matrix inversion in the reanalysis algorithm. The influence matrix—numerical core of the VDM—contains the whole mechanical knowledge about a structure, by looking at all global responses due to local disturbances. The strength of the method is demonstrated for truss structures.     

Physical properties of muffins sweetened with steviol glycosides as the sucrose replacement

Overconsumption of sweets contributes to increasing obesity among children and adults. Functional food brings an opportunity to improve nutritional value of commonly eaten products, e.g., pastry products. New trends in the food industry tend to produce low-calorie products by replacing sugar or fat with additives having pro-health benefits. The aim of this study was to determine the effect of replacing sucrose with steviol glycosides (natural non-caloric sweetener) on the quality properties of bakery products. The analysis of muffin’s texture, color, cooking yield, browning index, and sensory analysis were performed. The study showed that a 25% addition of steviol sweetener (as a sucrose replacement) was the most appropriate modification of the basic formula. The resulting muffins gained sensory attractiveness and health-promoting qualities. Moreover, the study showed that a reduction of sucrose in excess of 50% had a negative impact on the quality of muffins and their sensory profiles.