Sorption studies of heavy metal ions on pectin-nano-titanium dioxide composite adsorbent

The Cu(II), Cd(II), Zn(II), and Pb(II) sorption kinetics and equilibrium on hybrid material, composed of pectin and titanium dioxide nanopowder, were examined. Parameters, such as pH and adsorbent dose, were also investigated. The experimental data were better described by the Langmuir model. The maximum adsorption capacities were 1.37, 0.68, 0.51, and 0.83 mmol/g for Cu(II), Cd(II), Zn(II), and Pb(II), respectively. The introduction of nano-TiO₂ improved the kinetics of the metal ion sorption. The titanium dioxide, despite its small content (6%), contributes to the removal of the examined metal ions and eventually to the adsorption capacity of hybrid beads.     

A sex attractant for the scarab beetle Anomala solida Er

(R,Z)-5-(-)-(Oct-1-enyl)oxacyclopentan-2-one (R-buibuilactone) attracted male Anomala solida Er. (Coleoptera: Scarabaeidae, Rutelinae), a vineyard and orchard pest in Southeastern Europe. The presence of the corresponding (S) enantiomer or of 2-(E)-nonen-1-ol (a frequently found pheromone component in other Anomala spp.) in the bait did not influence catches. Traps baited with (R,Z)-5-(-)-(oct-1-enyl)oxacyclopentan-2-one were successfully used for monitoring the flight of A. solida, and may have practical applications for detection, monitoring, and mass trapping of the pest.     

1-Methylethyl Octanoate, a New Lepidopteran Sex Pheromone from the Bagworm, Megalophanes viciella

Extracts obtained by rinsing the thorax and extracts from the tergal sex pheromone gland of females of the bagworm moth, Megalophanes viciella, as well as headspace samples from live animals, were analyzed to reveal the chemical structure of the pheromone. As a result, 1-methylethyl octanoate was established as a main sex pheromone component of this species. This was further confirmed by numerous catches of conspecific males in traps baited with this compound in Bulgaria and Roumania.     

Sex Pheromone of Female Vine Bud Moth, Theresimima ampellophaga Comprises (2S)-Butyl (7Z)-Tetradecenoate

The sex pheromone of the vine bud moth, Theresimima ampellophaga, released at the 3rd–5th abdominal tergites, was identified by coupled GC-EAG, GC-MS, and synthesis as (2S)-butyl (7Z)-tetradecenoate. For the first time, full stereochemistry is unambiguously defined for the sex pheromone of a member of the Zygaenidae. The synthetic compound caught significant numbers of males in field-trapping experiments.     

Attraction of male turnip mothsAgrotis segetum (Lepidoptera: Noctuidae) to sex pheromone components and their mixtures at 11 sites in Europe,Asia, and Africa

Selected combinations of (Z)-5-decenyl, (Z)-7-dodecenyl, and (Z)-9-tetradecenyl acetates, the pheromone components of the turnip mothAgrotis Segetum were tested for field attractancy at six, two, and three sites in Europe, Asia, and Africa, respectively. At all of the sites in Eurasia and in northern Africa the ternary mixture of the acetates captured most males, while at the sites south of the Sahara in Africa, (Z)-5-decenyl acetate alone was responsible for attraction. Differences in male attraction among the populations studied confirm the existence of significant population variation in the pheromone ofA. segetum. Interpretation of the present results together with earlier studies suggests that this variation is more or less continuous in Eurasia and north Africa, while a clearly distinct pheromone type is present in the areas south of the Sahara desert.     

Hydriding properties of the nanocomposite 85 wt.% Mg–15 wt.% Mg2Ni0.8Co0.2 obtained by ball milling

The hydrogen sorption properties of the nanocomposite 85 wt.% Mg–15 wt.% Mg₂Ni_0.8Co_0.2 obtained by mechanical alloying in inert atmosphere were investigated. Absorption measurements were performed under a hydrogen pressure P = 1 MPa at temperartures ranging from 373 to 573 K, while desorption studies proceeded at P = 0.15 MPa and temperatures of 573 and 553 K. The addition of the intermetallic compound Mg₂Ni_0.8Co0_0.2 was shown to improve the hydriding kinetics of magnesium. The composite exhibited a high hydrogen capacity which did not decrease even after a large number of absorption–desorption cycles. Comparison of the hydriding kinetics of the intermetallic compounds Mg₂Ni and Mg₂Ni_0.8Co_0.2 indicated facilitation of the process by the presence of cobalt in the alloy. Magnetic measurement data on Mg₂Ni_0.8Co_0.2 showed formation of superparamagnetic precipitations of nickel and cobalt playing the role of active centres for dissociative chemisorption of hydrogen. The behaviour of the composite was explained by the catalytic effect of the intermetallic Mg₂Ni_0.8Co0_0.2, the existence of Ni and Co clusters on the surface and the process of mechanical alloying.     

Hydrogen sorption properties of 90 wt% MgH2–10 wt% MeSi2 (Me = Ti, Cr)

The hydriding/dehydriding characteristics of 90 wt% MgH₂–10 wt% MeSi₂ (Me = Ti, Cr) composites, synthesized by ball milling under argon, were studied by Sievert’s type apparatus and by high-pressure differential scanning calorimetry (HPDSC). The composites have demonstrated similar absorption kinetics and capacity at temperature of 300 °C and a pressure of 1 MPa. They showed fast kinetics and achieved absorption capacity higher than 6 wt%. Slightly higher values for the enthalpy of hydriding and dehydriding were obtained at scanning conditions in the HPDSC for the composite 90 wt% MgH₂–10 wt% CrSi₂ compared to those for the composite with addition of TiSi₂.     

People Choice Modelling for Evacuation of Tall Buildings

Modelling people behaviour during emergencies has become an essential issue in attempting to increase safety aspects in buildings. This paper evaluates people’s choice behaviour for evacuation of tall buildings. A Stated Preference (SP) questionnaire was designed to understand underlying factors behind people behaviour and predict the likelihood of selecting evacuation lifts as opposed to stairs. Various scenarios including six different navigational cases, three levels for the density of people on stairs, three different number of people in the lift lobby and three vertical positions for refuge floors were administrated to 566 participants. A mixed logit model approach was then used to investigate how those factors influence the occupant’s decision-making as well as to capture the heterogeneity of different preferences among people. Traditionally, lifts were not allowed to be used in case of emergency, but the results indicate that people would tend to choose evacuation lifts in situations when they are suggested as the main exit option, and situations when stairs are overcrowded. Thus, if people are navigated by dynamic signs to use evacuation lifts, the percentage of lift users could go approximately from 70% to 80% for refuge floors between 15 and 55, respectively. In contrast, in situations when people have to make a decision between using lifts or stairs to evacuate, stairwells with fewer people as well as overcrowded refuge floors could lead to a decision in favour of stairs. This study represents the first SP experiment combining people decisions, pre-event opinions and beliefs related to evacuation lifts and stairs to understand their route choices for evacuation from tall buildings. The findings of this study can be used in the development of behavioural models for evacuation simulations of tall buildings.     

Major Sex Pheromone Component of Female Herald Moth Scoliopteryx libatrix is the Novel Branched Alkene (6Z,13)-Methylheneicosene

The major component of the female-produced sex pheromone of Scoliopteryx libatrix has been characterized by chemical analysis, synthesis, electrophysiological studies and field tests as (6Z,13)-methylheneicosene, probably the 13S-isomer. This is the first example of a branched chain alkene as a sex pheromone in the Noctuidae and is markedly different from the pheromones of other members of the family. The systematic position of S. libatrix, belonging to a monotypic genus of a one-member subfamily within the Noctuidae, may reflect the unusual structure of the sex pheromone.