Factors influencing European passenger demand for air transport

Passenger air travel demand is influenced by various factors and is crucial to manufacturers, airlines, airports and wider industry. In order to gain detailed insights into drivers of European air transport demand, five factors are analysed, both quantitatively and qualitatively. Focusing on the European air transport market, a detailed description of factors influencing air transport demand serves as input for a statistical analysis. Data from European countries on the gross domestic product per capita (GDP), urbanisation levels, the geographical location of a country, and the degree of education is used for the model. These explanatory variables are tested using a regression analysis in regard to their influence on the passengers’ demand for air transport. Results from the regression analysis reveal that the factors GDP, the geographical location of a country and the level of education are statistically significant, confirming GDP as a demand driver already examined within various studies that also include other factors as explanatory variables. Results also indicate the dynamics between the different factors, such as the positive relationship between income and level of education. Present studies are a good basis to show what drives demand, often focused at a global or country level. This analysis also confirms the essential determinants at a European level

A nonperturbative calculation of basic chiral QCD parameters within zero modes enhancement model of the QCD vacuum, 2

Basic chiral QCD parameters (the pion decay constant, quark and gluon condensates, the dynamically generated quark mass, etc) as well as the vacuum energy density have been calculated from first principles within a recently proposed zero modes enhancement (ZME) model of the QCD true vacuum. It is based on the solution to the Schwinger-Dyson (SD) equation for the quark propagator in the infrared (IR) domain. In order to analyze our numerical results we set a scale by the two different ways. First this was done at a scale responsible for dynamical chiral symmetry breaking (DCSB) at the fundamental quark level \Lambda_{CSBq}, defined as the double of the dynamically generated light quark mass m_d. In the second case m_d was reasonably taken to be 300 \le m_d \le 400 \ (MeV) otherwise first remains arbitrary. Our unique input data was chosen to be the pion decay constant in the chiral limt given by the chiral perturbation theory at the hadronic level (CHPTh). With the help of the nonperturbative gluon contributions to the vacuum energy density one can establish realistic lower bounds for the m_d. In both cases we obtain almost the same numerical results for all chiral QCD parameters. Phenomenological estimates of these quantites are in good agreement with our numerical results. Also our numerical result for the vacuum energy density agrees well with the QCD sum rules and random instanton liquid model (RILM) values for this quantity. One of the most important our conclusions is that the above mentioned scale of DCSB at the fundamental quark level \Lambda_{CSBq} and the scale at which confinement occurs \Lambda_c are nearly the same indeed. Nonperturbative vacuum structure, which emerges from the ZME model, appears to be well suited to describe quark confinement, DCSB, the Goldstone nature of th

Light Colored Scalar as Messenger of Up-Quark Flavor Dynamics in Grand Unified Theories

The measured forward-backward asymmetry in the t tbar production at the Tevatron might be explained by the additional exchange of a colored weak singlet scalar. Such state appears in some of the grand unified theories and its interactions with the up-quarks are purely antisymmetric in flavor space. We systematically investigate the resulting impact on charm and top quark physics. The constraints on the relevant Yukawa couplings come from the experimentally measured observables related to D0--D0bar oscillations, as well as di-jet and single top production measurements at the Tevatron. After fully constraining the relevant Yukawa couplings, we predict possible signatures of this model in rare top quark decays. In a class of grand unified models we demonstrate how the obtained information enables to constrain the Yukawa couplings of the up-quarks at very high energy scale.Comment: 13 pages, 11 figures, version as published in PR

Spectroscopy of the 1S0−3P0^1S_0-{}^3P_0 Clock Transition of 87^{87}Sr in an Optical Lattice

We report on the spectroscopy of the $5s^2 {}^1S_0 (F=9/2) \to 5s5p {}^3P_0 (F=9/2)$ clock transition of ${}^{87}{\rm Sr}$ atoms (natural linewidth of 1 mHz) trapped in a one-dimensional optical lattice. Recoilless transitions with a linewidth of 0.7 kHz as well as the vibrational structure of the lattice potential were observed. By investigating the wavelength dependence of the carrier linewidth, we determined the magic wavelength, where the light shift in the clock transition vanishes, to be $813.5\pm0.9$ nm.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Lett. (09/May/2003

Tunable gas permeation behavior in self-standing cellulose nanocrystal-based membranes

Biopolymers arise as environmentally benign alternatives to bio-accumulating, fossil resource-based synthetic polymers for a variety of applications, many of which require self-standing films or membranes. Novel sustainable amine-functionalized cellulose nanocrystals (CNCs) form dense films with low porosity suitable for gas barriers. Due to their brittleness, pure CNC membranes are challenging to work with but represent an attractive support material for selectivity-inducing additives. Supported ionic liquid membranes (SILMs) are promising due to their tunable properties and good performance in gas separation. In this study, we investigate the possibilities to realize such applications by applying glucose and ionic liquids (ILs) as additives with different functions in CNC-based membranes. By the choice of the plasticizer, the gas permeation behavior of the flexible self-standing films can be tuned from impermeable, using glucose as an additive, to permeable by addition of the ILs 1,3-dibutylimidazolium acetate and 1,3-ditetrahydrofurfurylimidazolium acetate. Tunability is also observed through the choice of the CNC source in the form of an inversed selectivity of the gas pair N2/O2, which was traceable to the CNCs’ source-specific properties. The contributions of the matrix and additive were analyzed by comparing CNC to chitosan membranes and considering gas solubilities and diffusivities. The obtained results underline the diversity and tunability of bio-derived functional materials.AB - Biopolymers arise as environmentally benign alternatives to bio-accumulating, fossil resource-based synthetic polymers for a variety of applications, many of which require self-standing films or membranes. Novel sustainable amine-functionalized cellulose nanocrystals (CNCs) form dense films with low porosity suitable for gas barriers. Due to their brittleness, pure CNC membranes are challenging to work with but represent an attractive support material for selectivity-inducing additives. Supported ionic liquid membranes (SILMs) are promising due to their tunable properties and good performance in gas separation. In this study, we investigate the possibilities to realize such applications by applying glucose and ionic liquids (ILs) as additives with different functions in CNC-based membranes. By the choice of the plasticizer, the gas permeation behavior of the flexible self-standing films can be tuned from impermeable, using glucose as an additive, to permeable by addition of the ILs 1,3-dibutylimidazolium acetate and 1,3-ditetrahydrofurfurylimidazolium acetate. Tunability is also observed through the choice of the CNC source in the form of an inversed selectivity of the gas pair Nsub>2/O, which was traceable to the CNCs’ source-specific properties. The contributions of the matrix and additive were analyzed by comparing CNC to chitosan membranes and considering gas solubilities and diffusivities. The obtained results underline the diversity and tunability of bio-derived functional materials

Tests of Full Scale Brick Veneer Steel Stud Walls to Determine Strength and Rain Penetration Characteristics

The design, construction and physical testing of five full scale (2.75 m x 5.2 m) brick veneer rain screen wall specimens are reported. Also, the documentation of the design and fabrication of a new test apparatus and of the development of test procedures are major components of the report. The test program included sequences of air pressure loading stages both with and without simulated rain to establish both the structural and rain penetration performances of the test walls. The test walls included four brick veneer/steel stud specimens and one brick veneer/concrete block specimen. Additional tests were performed on bricks, mortar and masonry assemblages to define relevant characteristics. The design and construction of the wall specimens were consistent with current practices in order to assess the appropriateness of these practices. The major points addressed in the report relate to the vulnerabilities of the wall system to excessive rain penetration and resulting moisture damage. In line with these concerns, the likelihood of veneer cracking, the impact of cracking on structural behaviour and on rain penetration and the importance of cavity compartmentalization were addressed. The conclusions indicated that brick veneer rain screen walls are vulnerable to rain penetration if adequate air tightness in the backup and clean comparted cavities are not provided. Also, it was concluded that veneer cracking is likely under full design loads. It is recommended that the design should address the properties of the brick veneer/backup wall system and that the veneer deflections should be limited to control the size of cracks

Taxic Revisions

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72423/1/j.1096-0031.2001.tb00112.x.pd

The Qt distribution of the Breit current hemisphere in DIS as a probe of small-x broadening effects

We study the distribution 1/sigma dsigma/dQt, where Qt is the modulus of the transverse momentum vector, obtained by summing over all hadrons, in the current hemisphere of the DIS Breit frame. We resum the large logarithms in the small Qt region, to next-to--leading logarithmic accuracy, including the non-global logarithms involved. We point out that this observable is simply related to the Drell-Yan vector boson and predicted Higgs Qt spectra at hadron colliders. Comparing our predictions to existing HERA data thus ought to be a valuable source of information on the role or absence of small-x (BFKL) effects, neglected in conventional resummations of such quantities.Comment: 16 pages, 3 figures, uses JHEP3.cl

Respiratory rate and ethylene production of whole and minimally processed beet roots submitted to ethylene and bioregulators treatments

Verificou-se o efeito do etileno e de biorreguladores sobre a atividade respiratória e a síntese de etileno em beterrabas minimamente processadas e inteiras. Para o processamento mínimo, as raízes foram selecionadas quanto à firmeza, cor e tamanho, descascadas, sanificadas, sendo em seguida cortadas em fatias (2 mm de espessura), enxaguadas e centrifugadas. Os tratamentos aplicados foram: etileno (1000 µL L-1), 1-metilciclopropeno (300 nL L-1) e ácido salicílico (500 mg L-1). Após os tratamentos, as beterrabas foram embaladas e armazenadas a 5±1ºC e 85±5% UR durante 10 dias. Observou-se que o ácido salicílico promoveu a diminuição da atividade respiratória do produto minimamente processado durante o armazenamento. Além disso, verificou-se que a resposta fisiológica de beterraba minimamente processada é diferente de beterraba inteira, o que foi comprovada ao se analisar a atividade respiratória e a produção de etileno, que foram significativamente maiores no produto minimamente processado.The objective of this work was to evaluate the effects of ethylene and bioregulators on the respiratory activity and ethylene synthesis of minimally processed and whole beet roots. For the minimal processing, beet roots were graded for firmness, color and size, and were peeled. Roots were then sanitized, shredded (2 mm thick), rinsed and centrifuged. The following treatments were applied: ethylene (1000 µL L-1), 1-methylciclopropene (300 nL L-1) and salicylic acid (500 mg L-1). After treatments, beet roots were packed and stored at 5±1 ºC and 85±5% RH during 10 days. It was observed that salicylic acid use promoted the decrease of respiratory rates of minimally processed beet roots during all storage time. It was also noted difference between whole and minimally processed beet roots physiology. This difference was observed by the high values of respiratory activity and ethylene production rates in the minimally processed beet roots.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP