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The fragmentation functions of quarks and gluons are measured in various three-jet topologies in Z decays from the full data set collected with the Delphi detector at the Z resonance between 1992 and 1995. The results at different values of transverse momentum-like scales are compared. A parameterization of the quark and gluon fragmentation functions at a fixed reference scale is given. The quark and gluon fragmentation functions show the predicted pattern of scaling violations. The scaling violation for quark jets as a function of a transverse momentum-like scale is in a good agreement with that observed in lower energy \\({\\rm e}^+{\\rm e}^-\\) annihilation experiments. For gluon jets it appears to be significantly stronger. The scale dependences of the gluon and quark fragmentation functions agree with the prediction of the DGLAP evolution equations from which the colour factor ratio \\(C_A/C_F\\) is measured to be:

An update of the searches for charginos and neutralinos in DELPHI is presented, based mainly on recent data collected at centre-of-mass energies of 161 GeV and 172 GeV. No signal is found. For a sneutrino with mass above 300 GeV/c2 and a mass difference between the chargino and the lightest neutralino above 10 GeV/c2, the lower limit at 95% confidence level on the chargino mass ranges from 84.3 GeV/c2 to the kinematical limit (86.0 GeV/c2), depending on the mixing parameters. The limit decreases for lower chargino-neutralino mass differences. The limit in the case of a light sneutrino is 67.6 GeV/c2, provided that that there is no light sneutrino with a mass within 10 GeV/c2 below the chargino mass. Upper limits on neutralino pair production cross-sections of about a picobarn are derived. The (μ,M2) domain excluded in the MSSM-GUT scenario is determined by combining the neutralino and chargino searches. These results imply a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 24.9 GeV/c2 for tanß >- 1. The search has also been extended to the case where the lightest neutralino is unstable and decays into a photon and a gravitino. imply a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 24.9 GeV/c2 for tanß >- 1. The search has also been extended to the case where the lightest neutralino is unstable and decays into a photon and a gravitino.

Data taken by DELPHI during the 1995 and 1996 LEP runs have been used to search for the supersymmetric partners of electron, muon and tau leptons and of top and bottom quarks. The observations are in agreement with standard model predictions. Limits are set on sfermion masses. Searches for long lived scalar leptons from low scale supersymmetry breaking models exclude stau masses below 55 GeV/c2 at the 95% confidence level, irrespective of the gravitino mass.

Muon pair production in the process \\(e^+e^-\\to e^+e^-\\mu^+\\mu^-\\) is studied using the data taken at LEP1 (\\(\\sqrt{s}\\simeq m_Z\\)) with the DELPHI detector during the years 1992-1995. The corresponding integrated luminosity is 138.5 pb\\(^{-1}\\). The QED predictions have been tested over the whole \\(Q^2\\) range accessible at LEP1 (from several GeV\\(^2/c^4\\) to several hundred GeV\\(^2/c^4\\)) by comparing experimental distributions with distributions resulting from Monte Carlo simulations using various generators. Selected events are used to extract the leptonic photon structure function \\(F_2^\\gamma\\). Azimuthal correlations are used to obtain information on additional structure functions, \\(F_A^\\gamma\\) and \\(F_B^\\gamma\\), which originate from interference terms of the scattering amplitudes. The measured ratios \\(F_A^\\gamma/F_2^\\gamma\\) and \\(F_B^\\gamma/F_2^\\gamma\\) are significantly different from zero and consistent with QED predictions.

Data taken by the DELPHI experiment at centre-of-mass energies of 183 GeV and 189 GeV with a total integrated luminosity of 212 pb-1 have been used to search for the supersymmetric partners of the electrons, muons, and taus in the context of the Minimal Supersymmetric Standard Model (MSSM). The decay topologies searched for were the direct decay (ℓ̃ → ℓx̃), producing acoplanar lepton pairs plus missing energy, and the cascade decay (ℓ → ℓx̃0 2 → ℓγx̃0 1), producing acoplanar lepton and photon pairs plus missing energy. The observed number of events is in agreement with Standard Model predictions. The 95% CL excluded mass limits for selectrons, smuons and staus are mẽ ≤ 87 GeV/c2, mμ̃ ≤ 80 GeV/c2 and mτ̃ 75 GeV/c2, respectively, for values of μ=-200 GeV/c2 and tanβ=1.5.

The purpose of this research is to investigate a variety of approaches to the conversion of biomass, with a particular emphasis on employing anaerobic digestion and biogas upgrading systems. An analysis of the existing technologies is performed, with a focus on highlighting the benefits and downsides of each alternative. In order to assess the effects of nitrogen and oxygen in the biogas on the cryogenic distillation process, an investigation is being carried out. The findings suggest that the presence of these two chemical species in the biogas necessitates the final condensation of methane in order to separate them from one another. In conclusion, a qualitative economic analysis is carried out in order to ascertain the most cost-effective strategy that can be implemented in a typical Italian installation. According to the assumptions that were used, membrane separation is the solution that offers the most cost-effectiveness.

Internal combustion engines (ICEs) currently account for approximately 25% of global power generation. Notably, this technology still plays a crucial role in a large segment of the transportation sector. In this editorial, a short overview of the latest developments and current research trends related to internal combustion engines is presented. Furthermore, the 11 contributions of this Special Issue are introduced. They cover three main topics: the use of new fuels for internal combustion engines for both automotive and railway applications; testing of additives for ICEs fed with conventional fuels; and CFD simulation applied to the analysis and design of ICE components.

Anatomical similarity across the neocortex has led to the common assumption that the circuitry is modular and performs stereotyped computations. Layer 5 pyramidal neurons (L5PNs) in particular are thought to be central to cortical computation because of their extensive arborisation and nonlinear dendritic operations. Here, we demonstrate that computations associated with dendritic Ca2+ plateaus in mouse L5PNs vary substantially between the primary and secondary visual cortices. L5PNs in the secondary visual cortex show reduced dendritic excitability and smaller propensity for burst firing. This reduced excitability is correlated with shorter apical dendrites. Using numerical modelling, we uncover a universal principle underlying the influence of apical length on dendritic backpropagation and excitability, based on a Na+ channel-dependent broadening of backpropagating action potentials. In summary, we provide new insights into the modulation of dendritic excitability by apical dendrite length and show that the operational repertoire of L5PNs is not universal throughout the brain.

This study investigates the combustion process in a marine spark-ignition engine fueled with an ammonia–hydrogen blend (15% hydrogen by volume) using a passive pre-chamber. A 3D-CFD model, supported by a 1D engine model, was employed to analyze equivalence ratios between 0.7 and 0.9 and pre-chamber nozzle diameters from 7 to 3 mm. Results indicate that combustion is consistently initiated by turbulent jets, but at an equivalence ratio of 0.7, the charge combustion is incomplete. For lean mixtures, reducing nozzle size improves flame propagation, although not sufficiently to ensure stable operation. At an equivalence ratio of 0.8, reducing the nozzle diameter from 7 to 5 mm advances CA50 by about 6 CAD, while further reduction causes minor variations. At richer conditions, nozzle diameter plays a negligible role. Optimal performance was achieved with a 7 mm nozzle at equivalence ratio 0.8, delivering about 43% efficiency and 1.17 MW per cylinder.