Conductometric study of sodium dodecyl sulfate - nonionic surfactant (Triton X-100, Tween 20, Tween 60, Tween 80 or Tween 85) mixed micelles in aqueous solution

The present study is concerned with the determination of the critical micelle concentration (cmc) of mixed micelles of sodium dodecyl sulfate with one of five nonionic surfactants (Triton X-100, Tween 20, Tween 60, Tween 80 or Tween 85) from conductance measurements. Based on the calculated values of the β parameters we have noticed that SDS-nonionic surfactants mostly showed strong synergistic effect. It was found that nonionic surfactants with mainly longer and more hydrophobic tail show stronger interactions with hydrophobic part of SDS, thus expressing stronger synergism. In SDS-Tween 80 binary system the strongest synergistic effect was noticed. SDS-Tween 85 micellar system showed antagonistic effect, most probably because the presence of the double bond in its three hydrophobic tails (three C18 tails) makes it sterically rigid

Boundary effects in the stepwise structure of the Lyapunov spectra for quasi-one-dimensional systems

Boundary effects in the stepwise structure of the Lyapunov spectra and the corresponding wavelike structure of the Lyapunov vectors are discussed numerically in quasi-one-dimensional systems consisting of many hard-disks. Four kinds of boundary conditions constructed by combinations of periodic boundary conditions and hard-wall boundary conditions are considered, and lead to different stepwise structures of the Lyapunov spectra in each case. We show that a spatial wavelike structure with a time-oscillation appears in the spatial part of the Lyapunov vectors divided by momenta in some steps of the Lyapunov spectra, while a rather stationary wavelike structure appears in the purely spatial part of the Lyapunov vectors corresponding to the other steps. Using these two kinds of wavelike structure we categorize the sequence and the kinds of steps of the Lyapunov spectra in the four different boundary condition cases.Comment: 33 pages, 25 figures including 10 color figures. Manuscript including the figures of better quality is available from http://newt.phys.unsw.edu.au/~gary/step.pd

A new method for assessing squash tactics using 15 court areas for ball locations

Tactics in squash have typically been assessed using the frequency of different shot types played at different locations on the court either without reference to other relevant information or on the basis of the preceding shot. This paper presents a new squash specific method for categorising court locations in which the ball was played, a novel techniques for assessing the reliability of this method and presents typical shots responses in these new areas controlled for preceding shot as well as the time between shots and the handedness of the players. Twelve games were viewed using the SAGIT/Squash software and 2907 shots viewed a second time from a video image taken from behind the court with an overall agreement of 88.90% for the court location data and 99.52% for shot type. 3,192 shots from 9 matches from the 2003 World Team Championships were analysed in SAGIT/Squash. In the court areas analysed between 2 and 7 shot responses were predominant suggesting tactical patterns were evident. This was supported by differences evident between shot responses played from the two back corners where the backhand side was characterised by a predominance of straight drives whereas straight and crosscourt drives were played on the forehand side. These results tended to confirm that tactics i.e. consistent shot types, are played although these are only apparent when factors that determine shot selection are accounted for. This paper has controlled for some of these factors but others need to be considered e.g. if individual player profiles are to be ascertaine

The influence of chemical characteristics of precipitation on tree health in Banjica Forest (Belgrade, Serbia)

The most represented tree species in the Banjica Forest are Acer negundo, Quercus robur, Acer pseudoplatanus, Populus nigra, Fraxinus pennsylvanica, Fraxinus ornus and Robinia pseudoacacia. According to the ICP Forests combined assessment (degree of defoliation and decolorization), endangered species are Populus nigra (64.3% of heavily damaged trees), Quercus robur (45.5%), Fraxinus pennsylvanica (37.0%) and Acer negundo (26.6%), while the situation is much better for Acer pseudoplatanus and Fraxinus ornus. For Robinia pseudoacacia, 83% of trees are without decolorization, however, defoliation is established. In the period from April to October 2009, the average pH of rainwater was 5.46, and 5.18 in the period from November 2009 to March 2010. The concentration of SO42- in the period from April to October 2009 amounted to an average of 24.21 mg/l, and 28.87 mg/l in the period from November 2009 to March 2010. The concentration of SO42- and pH values is a possible explanation for the condition of the trees. [Acknowledgments. The results are a part of the project III47007 funded by the Ministry of Education and Science of the Republic of Serbia.

Comment on ``Lyapunov Exponent of a Many Body System and Its Transport Coefficients''

In a recent Letter, Barnett, Tajima, Nishihara, Ueshima and Furukawa obtained a theoretical expression for the maximum Lyapunov exponent $\lambda_1$ of a dilute gas. They conclude that $\lambda_1$ is proportional to the cube root of the self-diffusion coefficient $D$, independent of the range of the interaction potential. They validate their conjecture with numerical data for a dense one-component plasma, a system with long-range forces. We claim that their result is highly non-generic. We show in the following that it does not apply to a gas of hard spheres, neither in the dilute nor in the dense phase.Comment: 1 page, Revtex - 1 PS Figs - Submitted to Physical Review Letter

Predicting of lead distribution and immobilization in soil of the region of lignite mining (Rudovci, Serbia)

Lead distribution and immobilization in cultivated soils in Rudovci, Serbia was investigated. Sampling was carried out by the method recommended by ICP-Forests Manual, 2006, Part III Sampling and analysis of Soil. The sampling geometry was systematically designed with a random component. The maximum sampling depth was 100 cm and lead distribution was monitored during 425 days. First sample was taken after 50 days and every single next sample was taken after 50 days except for the last sample which was taken after 25 days. Before the profile contamination, physical and chemical soil analysis has been done. The cation exchange capacity of the soil was done because media affect mobility cations (anions) in soil. The effect of immobilizations of Pb is highest in the second horizons where the depth of investigating soil is 25-50 cm

Predicting of lead distribution and immobilization in soil of the region of lignite mining (Rudovci, Serbia)

Lead distribution and immobilization in cultivated soils in Rudovci, Serbia was investigated. Sampling was carried out by the method recommended by ICP-Forests Manual, 2006, Part III Sampling and analysis of Soil. The sampling geometry was systematically designed with a random component. The maximum sampling depth was 100 cm and lead distribution was monitored during 425 days. First sample was taken after 50 days and every single next sample was taken after 50 days except for the last sample which was taken after 25 days. Before the profile contamination, physical and chemical soil analysis has been done. The cation exchange capacity of the soil was done because media affect mobility cations (anions) in soil. The effect of immobilizations of Pb is highest in the second horizons where the depth of investigating soil is 25-50 cm

Ecologically acceptable usage of derivatives of essential oil of sweet basil, Ocimum basilicum, as antifeedants against larvae of the gypsy moth, Lymantria dispar

Ethanol solutions of five fractions obtained from essential oil of sweet basil Ocimum basilicum L. (Lamiales: Lamiaceae) (F1-F5) were tested for their antifeedant properties against 2nd instar gypsy moth larvae, Lymantria dispar L. (Lepidoptera: Lymantriidae), in laboratory non-choice and feeding-choice experiments. Prior to bioassays, the chemical composition of each fraction was determined by gas chromatography analyses. Significant larval deterrence from feeding was achieved by application of tested solutions to fresh leaves of the host plant. The most effective were F1 (0.5%), F4 (0.05, 0.1, and 0.5%), and F5 (0.1 and 0.5%), which provided an antifeedant index > 80% after five days. A low rate of larval mortality was observed in no-choice bioassay. In situ screening of chlorophyll fluorescence as an indicator of plant stress level (assessed by the induced fluorometry) confirmed that the tested compounds did not cause alternations in the photosynthetic efficiency of treated leaves

Theoretical and experimental analysis of dynamic processes of pipe branch for supply water to the Pelton turbine

The paper presents the results of the analysis of pipe branch A6 to feed the Hydropower Plant ”Perućica” with integrated action Pelton turbines. The analysis was conducted experimentally (tensometric) and numerically. The basis of the experimental research is the numerical finite element analysis of pipe branch A6 in pipeline C3. Pipe branch research was conducted in order to set the experiment and to determine extreme stress states. The analysis was used to perform the determination of the stress state of a geometrically complex assembly. This was done in detail as it had never been done before, even in the design phase. The actual states of the body pipe branch were established, along with the possible occurrence of water hammer accompanied by the appearance of hydraulic oscillation. This provides better energetic efficiency of the turbine devices. [Projekat Ministarstva nauke Republike Srbije, br. TR35049 and br. TR 33040

The influence of chemical characteristics of precipitation on tree health in Banjica Forest (Belgrade, Serbia)

The most represented tree species in the Banjica Forest are Acer negundo, Quercus robur, Acer pseudoplatanus, Populus nigra, Fraxinus pennsylvanica, Fraxinus ornus and Robinia pseudoacacia. According to the ICP Forests combined assessment (degree of defoliation and decolorization), endangered species are Populus nigra (64.3% of heavily damaged trees), Quercus robur (45.5%), Fraxinus pennsylvanica (37.0%) and Acer negundo (26.6%), while the situation is much better for Acer pseudoplatanus and Fraxinus ornus. For Robinia pseudoacacia, 83% of trees are without decolorization, however, defoliation is established. In the period from April to October 2009, the average pH of rainwater was 5.46, and 5.18 in the period from November 2009 to March 2010. The concentration of SO42- in the period from April to October 2009 amounted to an average of 24.21 mg/l, and 28.87 mg/l in the period from November 2009 to March 2010. The concentration of SO42- and pH values is a possible explanation for the condition of the trees