Preparation, characterization and electrical conductivity studies of MWCNT/ZnO nanoparticles hybrid

Multiwall carbon nanotubes (MWCNTs) were decorated with crystalline zinc oxide nanoparticles (ZnO NPs) by wet chemical route to form MWCNT/ZnO NPs hybrid. The hybrid sample was characterized by scanning and transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Electrical conductivity of the hybrid can be tuned by varying the ZnO NPs content in the hybrid. In order to investigate the effect of nanoparticles loading on the conduction of MWCNTs network, electrical conductivity studies have been carried out in the wide temperature range 1.5-300K. The electrical conductivity of the hybrid below 100K is explained with the combination of variable range hopping conduction and thermal fluctuation induced tunnelling model. (C) 2009 Elsevier B.V. All rights reserved.

A new constraint programming approach for optimising a coal rail system

Because of the bottlenecking operations in a complex coal rail system, millions of dollars are costed by mining companies. To handle this issue, this paper investigates a real-world coal rail system and aims to optimise the coal railing operations under constraints of limited resources (e.g., limited number of locomotives and wagons). In the literature, most studies considered the train scheduling problem on a single-track railway network to be strongly NP-hard and thus developed metaheuristics as the main solution methods. In this paper, a new mathematical programming model is formulated and coded by optimization programming language based on a constraint programming (CP) approach. A new depth-first-search technique is developed and embedded inside the CP model to obtain the optimised coal railing timetable efficiently. Computational experiments demonstrate that high-quality solutions are obtainable in industry-scale applications. To provide insightful decisions, sensitivity analysis is conducted in terms of different scenarios and specific criteria. Keywords Train scheduling · Rail transportation · Coal mining · Constraint programming

Preparation and Characterization of Glycolipid-Bearing Multilamellar and Unilamellar Liposomes

The carbohydrate residues of glycosphingolipids were implicated in many biologic processes such as cell-to-cell interactions; and as receptors for some viruses, bacterial and plant toxins, hormones, and so forth, and invariably for all the lectins (1). However, their receptor functions remained poorly defined for a long time as they form micelles even at very low concentrations in aqueous medium. In micelles, the oligosaccharide chains are not expected to have a well defined orientation suitable for recognition by macromolecular ligands. This problem was overcome by incorporating them in model membranes, namely, the liposomes. The demonstration of lectin-glycolipid interaction using liposomal model membranes was a crucial development that established glycolipids as biological receptors. Moreover, glycolipid-bearing liposomes provide a convenient system for investigating the role of glycolipid density, orientation, and exposure of their oligosaccharide chains at the membrane interface relevant to their receptor function (2–4).

Nucleotidases in plants *1, , *2: III. Effect of metabolites on the enzyme hydrolyzing flavine adenine dinucleotide (FAD) from Phaseolus radiatus

The highly purified enzyme from mung bean seedlings hydrolyzing FAD at pH 9.4 and temperature 49 °, functioned with an initial fast rate followed by a second slower rate. The activity was linear with enzyme concentration over a small range of concentration and was dependent on the time of incubation. Inhibition of enzyme activity with increasing concentrations of AMP was sigmoid;concentrations less than 1 × 10−6 M were without effect, concentrations between 1 × 10−6 and 8 × 10−5 M inhibited by 20% and concentrations beyond 8 × 10−5 Image caused progressive inhibition. Concentrations beyond 1 × 10−3 Image inhibited the activity completely. Preincubation of the enzyme with PCMB or NEM, or aging, or reversible denaturation with urea abolished the inhibitory effect of AMP at concentrations lower than 8 × 10−6 Image . The aged enzyme could be reactivated by ADP.

Children’s Relationship to Plants among Primary School Children in Finland

There is considerable evidence that children in modern society are losing
their contact with nature and, more precisely, with green plants. Is this also the case in Finland, a northern country famous for its forests and wild nature? This study examines the relationship of 9- to 10-year-old Finnish schoolchildren with the green environment and plants. The data were gathered by a questionnaire
comprising structured and open-ended questions. The focus of the research was on two comparisons: first, on the nature and child relationship in rural and urban neighborhoods and, second, among boys and girls. Participants in the study amounted to a total of 76 children, 42 in the Helsinki suburb area and 34 in Paltamo. The results suggested that the children in rural surroundings had closer contact with nature than their urban associates. For example, the children of Paltamo reported to know the trees better, and considered human beings to be part of nature more often (100% vs. 76% of the pupils in Helsinki, P = 0,003). Similarly, the results showed that girls in the study (N = 48) were more interested in plants than boys (N = 28). For the girls, the beauty and joy of plants was important, whereas the boys appreciated plants as the source of life. After the pre-questioning, the children of Helsinki participated in an in-class horticultural intervention and 10 days later, answered a similar questionnaire again. The results of the open-ended questions revealed that equally to children in other Western countries, Finnish children may also be in danger of losing their direct contact with the natural environment. It was common to pass free time in organized sports such as hockey or football (boys), or by just walking and talking with friends (girls). Rural children told that they still built huts, pick berries, and climb trees, whereas urban children played in parks and city groves. The results suggest that it is essential to research
further the children’s own experiences if we are to understand, and subsequently, to enhance, the crucial role of the green environment in their lives. Horticultural interventions can be effective starting points to add to children’s knowledge, affection, and interest toward greenery, but it is highly recommended that they take place outdoors rather than indoors.

Using IRAP markers for analysis of genetic variability in populations of resource and rare species of plants

Species specific LTR retrotransposons were first cloned in five rare relic species of drug plants located in the Perm’ region. Sequences of LTR retrotransposons were used for PCR analysis based on amplification of repeated sequences from LTR or other sites of retrotransposons (IRAP). Genetic diversity was studied in six populations of rare relic species of plants Adonis vernalis L. by means of the IRAP method; 125 polymorphic IRAP markers were analyzed. Parameters for DNA polymorphism and genetic diversity of A. vernalis populations were determined.

Preparation, characterization and thermal decomposition of praseodymium, terbium and neodymium carbonates

The preparation of three different types of carbonates of praseodymium, neodymium and terbium has been described. The carbonates have been characterized by potentiometry, chemical analysis, X-ray crystallography, infra-red spectroscopy and by their thermal behaviour. The thermal decomposition of several carbonates has been studied exhaustively under a variety of conditions and the stoicheiometry, thermodynamics and energetics of the reactions at various stages of decomposition have been examined. The stoicheiometry of the oxides obtained as final products of decomposition has been examined.

Children’s Relationship to Plants among Primary School Children in Finland

There is considerable evidence that children in modern society are losing
their contact with nature and, more precisely, with green plants. Is this also the case in Finland, a northern country famous for its forests and wild nature? This study examines the relationship of 9- to 10-year-old Finnish schoolchildren with the green environment and plants. The data were gathered by a questionnaire
comprising structured and open-ended questions. The focus of the research was on two comparisons: first, on the nature and child relationship in rural and urban neighborhoods and, second, among boys and girls. Participants in the study amounted to a total of 76 children, 42 in the Helsinki suburb area and 34 in Paltamo. The results suggested that the children in rural surroundings had closer contact with nature than their urban associates. For example, the children of Paltamo reported to know the trees better, and considered human beings to be part of nature more often (100% vs. 76% of the pupils in Helsinki, P = 0,003). Similarly, the results showed that girls in the study (N = 48) were more interested in plants than boys (N = 28). For the girls, the beauty and joy of plants was important, whereas the boys appreciated plants as the source of life. After the pre-questioning, the children of Helsinki participated in an in-class horticultural intervention and 10 days later, answered a similar questionnaire again. The results of the open-ended questions revealed that equally to children in other Western countries, Finnish children may also be in danger of losing their direct contact with the natural environment. It was common to pass free time in organized sports such as hockey or football (boys), or by just walking and talking with friends (girls). Rural children told that they still built huts, pick berries, and climb trees, whereas urban children played in parks and city groves. The results suggest that it is essential to research
further the children’s own experiences if we are to understand, and subsequently, to enhance, the crucial role of the green environment in their lives. Horticultural interventions can be effective starting points to add to children’s knowledge, affection, and interest toward greenery, but it is highly recommended that they take place outdoors rather than indoors.

Nucleotidases in plants : I. Partial purification and properties of the enzyme hydrolyzing flavine adenine dinucleotide from mung bean seedlings (Phaseolus radiatus)

The occurrence of an enzyme hydrolyzing flavine adenine dinucleotide (FAD) was demonstrated in a number of seed extracts. The enzyme from Phaseolus radiatus was purified 104-fold by fractionation with ammonium sulfate and ethanol and by negative adsorption on alumina Cγ gel. The enzyme cleaves the POP bond of FAD to yield flavine mononucleotide and adenosine monophosphate. When reduced glutathione is added to the enzyme, it cleaves FAD at the COP bond to yield riboflavine, adenosine, and pyrophosphate, Both the activities are optimal at a pH of 7.2 and at a temperature of 37 . The Km for both the activities is 1.65 × 10−5 M. The stoichiometry and the identity of the products of both the treated and untreated enzyme were established. The untreated enzyme was not inhibited by pCMB or arsenite, but the treated enzyme was sensitive to both these inhibitors. The inhibition by pCMB could be reversed by monothiols and the inhibition by arsenite by dithiols.

Preparation of lithium amalgam

Lithium amalgam is useful in effecting Wurtz type intramolecular and intermolecular coupling reactions.

Biosynthesis of valine and isoleucine in plants II. Dihydroxyacid dehydratase from Phaseolus radiatus

1. 1. An enzyme catalysing the conversion of α,β-dihydroxyisovalerate and α,β-dihydroxy-β-methylvalerate to α-ketoisovalerate and α-keto-β-methylvalerate has been partially purified from green gram (Phaseolus radiatus), and its characteristics studied. 2. 2. A natural inhibitor, heat stable and inorganic in nature, was observed in the crude extracts. 3. 3. The observed Km values for α-β-dihydroxyisovalerate and α,β-dihydroxy-β-methylvalerate were 2.4 · 10-3 M and 9 · 10-4 M, respectively. 4. 4. The enzyme required the presence of a divalent metal ion (Mg2+, Mn2+ or Fe2+) for maximal activity. Heavy metals like Ag+ and Hg2+ were inhibitory. 5. 5. The optimal activity was around pH 8.0 and the optimum temperature at 52°. The activation energy is found to be 12 600 cal/mole. 6. 6. The enzyme was inhibited by p-hydroxymercuribenzoate, N-ethylmaleimide and sulphydryl compounds like cysteine, glutathione, 2-mercaptoethanol and 2,3-dimercaptopropanol. The inhibition by p-hydroxymercuribenzoate could not be reversed by any of the sulfhydryl compounds tested.

Using IRAP markers for analysis of genetic variability in populations of resource and rare species of plants

Species specific LTR retrotransposons were first cloned in five rare relic species of drug plants located in the Perm’ region. Sequences of LTR retrotransposons were used for PCR analysis based on amplification of repeated sequences from LTR or other sites of retrotransposons (IRAP). Genetic diversity was studied in six populations of rare relic species of plants Adonis vernalis L. by means of the IRAP method; 125 polymorphic IRAP markers were analyzed. Parameters for DNA polymorphism and genetic diversity of A. vernalis populations were determined.

Children’s Relationship to Plants among Primary School Children in Finland

There is considerable evidence that children in modern society are losing
their contact with nature and, more precisely, with green plants. Is this also the case in Finland, a northern country famous for its forests and wild nature? This study examines the relationship of 9- to 10-year-old Finnish schoolchildren with the green environment and plants. The data were gathered by a questionnaire
comprising structured and open-ended questions. The focus of the research was on two comparisons: first, on the nature and child relationship in rural and urban neighborhoods and, second, among boys and girls. Participants in the study amounted to a total of 76 children, 42 in the Helsinki suburb area and 34 in Paltamo. The results suggested that the children in rural surroundings had closer contact with nature than their urban associates. For example, the children of Paltamo reported to know the trees better, and considered human beings to be part of nature more often (100% vs. 76% of the pupils in Helsinki, P = 0,003). Similarly, the results showed that girls in the study (N = 48) were more interested in plants than boys (N = 28). For the girls, the beauty and joy of plants was important, whereas the boys appreciated plants as the source of life. After the pre-questioning, the children of Helsinki participated in an in-class horticultural intervention and 10 days later, answered a similar questionnaire again. The results of the open-ended questions revealed that equally to children in other Western countries, Finnish children may also be in danger of losing their direct contact with the natural environment. It was common to pass free time in organized sports such as hockey or football (boys), or by just walking and talking with friends (girls). Rural children told that they still built huts, pick berries, and climb trees, whereas urban children played in parks and city groves. The results suggest that it is essential to research
further the children’s own experiences if we are to understand, and subsequently, to enhance, the crucial role of the green environment in their lives. Horticultural interventions can be effective starting points to add to children’s knowledge, affection, and interest toward greenery, but it is highly recommended that they take place outdoors rather than indoors.

Hydrolysis of riboflavin in plants

The enzymic hydrolysis of riboflavin to lumichrome and ribitol by extracts of Crinum longifolium bulbs has been demonstrated. The enzyme was purified 48-fold by ZnSO4 treatment and ethanol fractionation, and concentrated by using Sephadex G-25. After establishing the stoichiometry of the reaction, the general properties of the purified enzyme were studied. The enzyme showed maximal activity at pH 7·5, and it had a requirement for reduced glutathione which could be replaced by cysteine or ascorbic acid. Mg2+ and Li+ activated the enzyme. The reaction was highly specific to riboflavin and was competitively inhibited by riboflavin 5′-phosphate.