Morphogenesis in Vitro in Maize Inbred Lines from the Lancaster Heterotic Group

The genotypic specificities of morphogenesis and regeneration have been studied in vitro in five maize inbred lines from the breeding-promising Lancaster heterotic group, compared with the representatives of other heterotic groups, that is, PLS61, A188, and Chi31. It has been shown that the ratio between the types of morphogenesis, such as organogenesis and embryoidogenesis, in a callus culture is predetermined by the explant genotype and sucrose concentrations in the medium for callusogenesis. The frequency of embryoidogenesis as the most efficient type of morphogenesis, considering further regeneration, was, on average, 40.0 ± 12.8% for maize inbreds from the Lancaster heterotic group and only 14.0 ± 4.0% from other heterotic groups. A sucrose concentration at a level of 30 g/L in the medium for callusogenesis further supported the process of regeneration through embryoidogenesis in inbreds of the Lancaster heterotic group at a level of 26.5 ± 15.4%, while the sucrose concentration of 60 g/L promoted regeneration up to a level of 57.7± 19.8%. Contents of sucrose in the medium for callusogenesis in the inbreds representing other heterotic groups did not affect the process of regeneration, and the level of embryoidogenesis with sucrose at the concentrations of 30 and 60 g/L was, respectively, 11.0 ± 7.0 and 15.0 ± 4.8%

Revision of the genus Serboiulus Strasser, 1962 (Diplopoda, Julidae)

Serboiulus lucifugus Strasser, 1962 and S. deelemani Strasser, 1972 are upgraded to the species level from subspecific status under Serboiulus Strasser, 1962. The position of the genus Serboiulus in the tribe Typhloiulini Verhoeff, 1930 is discussed, and a key to Serboiulid species is presented

Charge-trapping capability and AC conductivity at different humidities of poly(ethyleneimine)-TiO2-anthocyanin modified cellulose fibres.

Modified cellulose materials are finding increasing application in electronics, because of the need for more environmental-friendly electronic circuits. The papers prepared from poly(ethyleneimine)–TiO2–anthocyanin-modified cellulose fibres are completely environmentally friendly and can be applied to the construction of photocells or photo-/humidity sensors. To better understand the mechanisms of electrical conductivity of the said cellulose composites, the effect of humidity (RH = 9% → 100%) on its dielectric properties is presented in this article. The possibility of trapping the negative and positive charges in the composite under different humidity conditions is also examined. A large number of studies suggest that proton conductivity, stimulated by humidity, is the dominant mechanism of electrical conductivity in cellulose-based materials. The results presented in this paper indicate that the electronic conductivity mechanisms also play a significant role in papers prepared from poly(ethyleneimine)–TiO2–anthocyanin-modified cellulose fibres.This work was supported in part by the Ministry of Education and Science, Republic of Serbia (Project Nos. 171029), and by the environment conscious energy efficient building TAMOP-4.2.2.A–11/1/KONV-2012-0068 project sponsored by the EU and European Social Foundation, and in part by the National Research Foundation, South Africa (Grant No. 88301)

Generation of photo charge in poly(ethyleneimine)-TiO2-anthocyanin modified papers conditioned at different humidities.

The article describes the influence of humidity on the surface photodielectric properties of papers prepared from poly(ethyleneimine)-TiO2 nanoparticles-anthocyanin modified cellulose fibres. The anthocyanins were extracted from purple cabbage, beet-root, plum peel, red wine and red currant juice. The samples were conditioned to various relative humidities (from 9 to 100%) and illuminated with white visible light, λ ≥ 405 nm. The poly(ethyleneimine)-TiO2-anthocyanin modified samples showed similar photodielectric behaviour that can be clearly distinguished from the samples modified solely with poly(ethyleneimine)-TiO2. Generally, an increase in humidity enhances the conductivity of the samples and induces an increase in the amount of photo-induced charge. Also, at higher humidities (above 80%), the samples with anthocyanin showed significantly higher values of photo-induced charges with respect to anthocyanin free samples. The presented results suggest that the presence of water molecules promotes electron-injection processes from the anthocyanin to the semiconductor surface.This work was supported in part by the Ministry of Education and Science, Republic of Serbia (Project Nos. 171029, 172056, and 45020), by the Environment conscious energy efficient building TAMOP-4.2.2.A–11/1/KONV-2012-0068 project sponsored by the EU and European Social Foundation and by the National Research Foundation, South Africa (Grant No. 88301)

Comparative characteristics of ductile iron and austempered ductile iron modeled by neural network

© 2019 by the authors. Experimental research of cutting force components during dry face milling operations are presented in the paper. The study was provided when milling of ductile cast iron alloyed with copper and its austempered ductile iron after the proper austempering process. In the study, virtual instrumentation designed for cutting forces components monitoring was used. During the research, orthogonal cutting forces components versus time were monitored and relationship of cutting forces components versus speed, feed and depth of cut were determined by artificial neural network and response surface methodology. An analysis was made regarding the consistency of the measured cutting forces and the values obtained from the model supported by an artificial neural network for the investigated interval of the cutting regime. Based on the results, an analysis of the feasibility of the application of austempered ductile iron in the industrial sector with the aspect of machinability as well as the application of the models based on artificial intelligence, was given. At the end of the presentation, the influence of the aforementioned cutting regimes on cutting force components is presented as well

Ionic diffusion in iPP: DC electrical conductivity

This study provides a new insight into the relationships between absorption and adsorption processes that occur during the treatment of iPP in aqueous solutions of metal-chloride salts, as well as the impact of these processes on the electrical conductivity of this nonpolar polymer. The polypropylene films (0.5 mm) were exposed to three-day treatments in aqueous solutions of chlorine salts of some alkali and transition metals at temperatures of 22 C and 80 C. The treatments induced an increase in the electrical conductivity of iPP, up to 800%. DC conductivity is not directly proportional to the concentrations of metals in the treated films due to the complex relationships between diffusion and adsorption processes. The experiment was set up to simulate the real-world conditions and the study provides practical knowledge on the stability of the electrical conductivity of iPP under exposure to aqueous solutions. The influence of electric aging on the electrical conductivity of the treated films was also examined.This work was supported in part by the Ministry of Education, Science and Technological Development of the Republic of Serbia, by the Ministry of Scientific and Technological Development, Higher Education and Information Society of the Republic of Srpska (project: 19.032/961-112/19) and by the National Research Foundation, South Africa.Scopu