On Completely Integrability Systems of Differential Equations

In this note we discuss the approach which was given by Wazwaz for the proof of the complete integrability to the system of nonlinear differential equations. We show that his method presented in [Wazwaz A.M. Completely integrable coupled KdV and coupled KP systems, Commun Nonlinear Sci Simulat 15 (2010) 2828-2835] is incorrect.Comment: 14 pages. This paper was sent to the Communications in Nonlinear Science and Numerical Simulatio

Search for fermiophobic Higgs bosons in final states with photons at LEP 2

Higgs boson production with subsequent decay to photons was searched for in the data collected by the DELPHI detector at centre-of-mass energies between 183 GeV and 209 GeV, corresponding to a total integrated luminosity of nearly 650 pb^{-1}. No evidence for a signal was found, and limits were set on h0Z0 and h0A0 production with h0 decay to photons. These results were used to exclude regions in the parameter space of fermiophobic scenarios of Two Higgs Doublet Models.Comment: 24 pages, 6 figures, Accepted by Eur. Phys. J.

Solitary-wave solutions of the Degasperis-Procesi equation by means of the homotopy analysis method

The homotopy analysis method is applied to the Degasperis-Procesi equation in order to find analytic approximations to the known exact solitary-wave solutions for the solitary peakon wave and the family of solitary smooth-hump waves. It is demonstrated that the approximate solutions agree well with the exact solutions. This provides further evidence that the homotopy analysis method is a powerful tool for finding excellent approximations to nonlinear solitary waves

Do television and electronic games predict children's psychosocial adjustment? Longitudinal research using the UK Millennium Cohort Study

Background: Screen entertainment for young children has been associated with several aspects of psychosocial adjustment. Most research is from North America and focuses on television. Few longitudinal studies have compared the effects of TV and electronic games, or have investigated gender differences. Purpose: To explore how time watching TV and playing electronic games at age 5 years each predicts change in psychosocial adjustment in a representative sample of 7 year-olds from the UK. Methods: Typical daily hours viewing television and playing electronic games at age 5 years were reported by mothers of 11 014 children from the UK Millennium Cohort Study. Conduct problems, emotional symptoms, peer relationship problems, hyperactivity/inattention and prosocial behaviour were reported by mothers using the Strengths and Difficulties Questionnaire. Change in adjustment from age 5 years to 7 years was regressed on screen exposures; adjusting for family characteristics and functioning, and child characteristics. Results: Watching TV for 3 h or more at 5 years predicted a 0.13 point increase (95% CI 0.03 to 0.24) in conduct problems by 7 years, compared with watching for under an hour, but playing electronic games was not associated with conduct problems. No associations were found between either type of screen time and emotional symptoms, hyperactivity/inattention, peer relationship problems or prosocial behaviour. There was no evidence of gender differences in the effect of screen time. Conclusions: TV but not electronic games predicted a small increase in conduct problems. Screen time did not predict other aspects of psychosocial adjustment. Further work is required to establish causal mechanisms

Isomeric effects in the gas-phase reactions of dichloroethene, C2H2Cl2, with a series of cations

A study of the reactions of a series of gas-phase cations (NH$_4^+$, H$_3$O$^+$, SF$_3^+$, CF$_3^+$, CF$^+$, SF5$^+$, SF$_2^+$, SF$^+$, CF$_2^+$, SF$_4^+$, O$_2^+$, Xe$^+$, N$_2$O$^+$, CO$_2^+$, Kr$^+$, CO$^+$, N$^+$, N$_2^+$, Ar$^+$, F$^+$ and Ne$^+$) with the three structural isomers of dichloroethene, i.e. 1,1-C$_2$H$_2$Cl$_2$, cis-1,2-C$_2$H$_2$Cl$_2$ and trans-1,2-C$_2$H$_2$Cl$_2$ is reported. The recombination energy of these ions spans the range 4.7-21.6 eV. Reaction rate coefficients and product branching ratios have been measured at 298 K in a selected ion flow tube. Collisional rate coefficients are calculated by modified average dipole orientation theory and compared with experimental data. Thermochemistry and mass balance have been used to predict the most feasible neutral products. Threshold photoelectron-photoion coincidence spectra have also been obtained for the three isomers of C$_2$H$_2$Cl$_2$ with photon energies in the range 10-23 eV. The fragment ion branching ratios have been compared with those of the flow tube study to determine the importance of long-range charge transfer. A strong influence of the isomeric structure of dichloroethene on the products of ion-molecule reactions has been observed for H$_3$O$^+$, CF$_3^+$, and CF$^+$. For 1,1-C$_2$H$_2$Cl$_2$ the reaction with H$_3$O$^+$ proceeds at the collisional rate with the only ionic product being 1,1-C$_2$H$_2$Cl$_2$H$^+$. However, the same reaction yields two more ionic products in the case of cis-1,2- and trans-1,2-C$_2$H$_2$Cl$_2$, but only proceeds with 14 % and 18 % efficiency, respectively. The CF$_3^+$ reaction proceeds with 56-80 % efficiency, the only ionic product for 1,1-C$_2$H$_2$Cl$_2$ being C$_2$H$_2$Cl$^+$ formed via Cl- abstraction, whereas the only ionic product for both 1,2-isomers is CHCl$_2^+$ corresponding to a breaking of the C=C double bond. Less profound isomeric effects, but still resulting in different products for 1,1- and 1,2-C$_2$H$_2$Cl$_2$ isomers, have been found in the reactions of SF$^+$, CO$_2^+$, CO$^+$, N$_2^+$, and Ar$^+$. Although these five ions have recombination energies above the ionization energy of any of the C$_2$H$_2$Cl$_2$ isomers and hence the threshold for long-range charge transfer, the results suggest that the formation of a collision complex at short range between these ions and C$_2$H$_2$Cl$_2$ is responsible for the observed effects

Generalizing Boolean Satisfiability I: Background and Survey of Existing Work

This is the first of three planned papers describing ZAP, a satisfiability engine that substantially generalizes existing tools while retaining the performance characteristics of modern high-performance solvers. The fundamental idea underlying ZAP is that many problems passed to such engines contain rich internal structure that is obscured by the Boolean representation used; our goal is to define a representation in which this structure is apparent and can easily be exploited to improve computational performance. This paper is a survey of the work underlying ZAP, and discusses previous attempts to improve the performance of the Davis-Putnam-Logemann-Loveland algorithm by exploiting the structure of the problem being solved. We examine existing ideas including extensions of the Boolean language to allow cardinality constraints, pseudo-Boolean representations, symmetry, and a limited form of quantification. While this paper is intended as a survey, our research results are contained in the two subsequent articles, with the theoretical structure of ZAP described in the second paper in this series, and ZAP's implementation described in the third

Recent developments in advanced thermal analysis: sample controlled thermal analysis

The determination of the key physical and chemical properties of a new material is essential.The melting point, glass transition temperature, the number and identification of the different phases it may have, and the temperatures at which they are formed are all of great value, not only in assessing its practical pharmaceutical potential but also as they can form the basis of many routine QC procedures

Oscillator strength of the resonance transitions of ground-state N and O

Oscillator strength of resonance transitions of ground state nitrogen and oxyge

Soil mapping in modern high-density apple orchards

The use of EM38 soil mapping prior to planting has potential to provide significant benefit to the apple industry through informing soil amelioration work to improve soil homogeneity across orchard blocks. Reducing soil variability increases the chances of growing a uniform block of trees, which is essential for optimal productivity and efficient labour-use. This project aimed to determine a) if there is a relationship between soil zones defined by EM38 mapping, and productivity in apple orchard blocks, and b) if a relationship does exist, investigate whether productivity might be improved by conducting EM38 mapping prior to planting. EM38 soil maps, soil samples and tree productivity maps were collected and analysed from two high-density orchard blocks in the Stanthorpe region of Queensland. The results showed existence of a broad relationship between EM38 mapping zones and areas of high and low productivity in both blocks. Further data investigation and discussions with growers, suggested that use of the EM38 soil maps, together with grower knowledge of the site history, would have likely led to improved soil amelioration work prior to planting and changes to block design. This may have resulted in reduced variability in productivity and therefore greater profitability. It was concluded that EM38 soil mapping could be a cost-effective technology for guiding decision making at the point of site preparation and has significant potential to add value to orchard businesses. The combination of EM38 soil mapping with yield, and Normalized Difference Vegetation Index mapping technologies will likely provide greatest value in the future, particularly in the preparation of apple orchards for the use of robotic

Multimegawatt MPD thruster design considerations

Performance and lifetime requirements for multimegawatt magnetoplasmadynamic (MPD) thrusters were used to establish a baseline 2.5 MW thruster design. The chamber surface power deposition resulting from current conduction, plasma and surface radiation, and conduction from the hot plasma was then evaluated to establish the feasibility of thruster operation. It was determined that state of the art lithium heat pipes were adequate to cool the anode electrode, and that the liquid hydrogen propellant could be used to cool the applied field magnet, cathode, and backplate. Unresolved issues having an impact of thruster design are discussed to help focus future research