Theoretical aspects of high energy elastic nucleon scattering

The eikonal model must be denoted as strongly preferable for the analysis of elastic high-energy hadron collisions. The given approach allows to derive corresponding impact parameter profiles that characterize important physical features of nucleon collisions, e.g., the range of different forces. The contemporary phenomenological analysis of experimental data is, however, not able to determine these profiles unambiguously, i.e., it cannot give the answer whether the elastic hadron collisions are more central or more peripheral than the inelastic ones. However, in the collisions of mass objects (like protons) the peripheral behavior of elastic collisions should be preferred.Comment: 7 pages, 4 figure

Contemporary models of elastic nucleon scattering and their predictions for LHC

The analyses of elastic collisions of charged nucleons have been based standardly on West and Yennie formula. However, this approach has been shown recently to be inadequate from experimental as well as theoretical points of view. The eikonal model seems to be more pertinent as it enables to determine physical characteristics in impact parameter space. The contemporary phenomenological models cannot give, of course, any definite answer as the elastic collisions may be interpreted differently, as central or peripheral processes. Nevertheless, the predictions for the planned LHC energy have been given on their basis and the possibility of exact determination of luminosity has been considered.Comment: 11 pages, 6 figure

Reconstruction of elastic events

This note describes an elastic event reconstruction method developed for the TOTEM experiment. It is based on linear track parameterization and linear track fit. The suggested method has been implemented within simulation/reconstruction software framework, and results for the 1540 m and 90 m optics are given. The obtained resolution is compared to analytic estimates presented in the appendix

Description and simulation of beam smearing effects

This note addresses angular smearing (i.e. beam divergence), energy smearing and vertex smearing effects. Their mathematical description is given also for the case with non-zero crossing angle. Finally, the influence of angular smearing (the most relevant effect for the TOTEM experiment) on particles scattered to small angles is presented in an explicit form, useful for further studies

Oncology clinical trial design planning based on a multistate model that jointly models progression-free and overall survival endpoints

When planning an oncology clinical trial, the usual approach is to assume proportional hazards and even an exponential distribution for time-to-event endpoints. Often, besides the gold-standard endpoint overall survival (OS), progression-free survival (PFS) is considered as a second confirmatory endpoint. We use a survival multistate model to jointly model these two endpoints and find that neither exponential distribution nor proportional hazards will typically hold for both endpoints simultaneously. The multistate model provides a stochastic process approach to model the dependency of such endpoints neither requiring latent failure times nor explicit dependency modelling such as copulae. We use the multistate model framework to simulate clinical trials with endpoints OS and PFS and show how design planning questions can be answered using this approach. In particular, non-proportional hazards for at least one of the endpoints are naturally modelled as well as their dependency to improve planning. We consider an oncology trial on non-small-cell lung cancer as a motivating example from which we derive relevant trial design questions. We then illustrate how clinical trial design can be based on simulations from a multistate model. Key applications are co-primary endpoints and group-sequential designs. Simulations for these applications show that the standard simplifying approach may very well lead to underpowered or overpowered clinical trials. Our approach is quite general and can be extended to more complex trial designs, further endpoints, and other therapeutic areas. An R package is available on CRAN.Comment: 28 pages, 3 tables, 12 figure

A preliminary study of a multifunctional DOC/Wet-scrubber capable to reduce both chemical and acoustic emissions in marine field

The reduction of ship emissions (i.e., Nitrogen Oxides – NOx, Sulfur Oxides – SOx and Particulate Matter PM) are of paramount importance particularly when shipping in Emission Control Areas (ECAs) where restrictive limits on emissions are imposed by the International Maritime Organization (IMO). In such ECAs, which starting from 2025 will also include Mediterranean Sea, the use of Ultra Low Sulfur Fuel Oil (ULSFO – sulfur content ≤ 0.1 wt%) or, alternatively, an emission-equivalent Exhaust Gas Cleaning System (EGCS) is mandatory. The price of ULSFO is about twice that of the ordinary Heavy Fuel Oil, which heavily affects marine transport economics. Consequently, several EGCS concepts have been studied for the abatement of NOx, SOx and PM, yet they have big dimensions which preclude their installation on already existing ships and, therefore, making necessary the re-design of the whole propulsion system. In the presented study, the use of a Diesel Oxidation Catalyst (DOC) in series with a closed loop scrubber to reduce NOx, SOx, PM and acoustic emissions is studied with the aim to design a compact exhaust line, with multifunctional performances, that allow to be compliant with the IMO’s regulations. The role of the DOC is that of oxidizing the emitted NO to improve the solubility of the NOx species in the scrubber, besides hydrocarbons and PM abatement. It is shown that the oxidation activity and stability of the Pt-based catalysts can be significantly improved by doping with acidic oxides in comparison to a conventional Pt/Al2O3 catalyst. This allows to design a compact EGCS which, in addition to the chemical aspects, incorporates modification aimed at minimizing acoustic emissions as well, acting as a silencer. Preliminary results assessing the validity of the integrate system on a full engine-EGSC mockup are reported in the paper

Carbon-Rich Silicon Oxycarbide (SiOC) and Silicon Oxycarbide/Element (SiOC/X, X= Si, Sn) Nano-Composites as New Anode Materials for Li-Ion Battery Application

Carbon-rich silicon oxycarbide (SiOC) and silicon oxycarbide/element nano-composites (SiOC/X, X=Si, Sn) are prepared via thermal conversion of polyorganosiloxanes and studied as potential anode material for Li-ion battery application. The obtained materials are characterized by various chemical, structural, electrochemical and electro-analytical methods. The chemical composition and microstructure of the samples is analyzed and correlated with their electrochemical properties and performance. For carbon-rich SiOC, the lithium ion storage process, including the transport and mobility of lithium ions within the material, is investigated. The electrochemical properties of carbon-rich SiOC strongly correlate with the ceramic microstructure and phase composition, which in turn correlate with the final temperature of pyrolysis. Both, an increasing organization of free carbon within the microstructure and the gradual degradation of the amorphous Si-O-C network lead to reduced capacities and changing voltage profiles. According to electro-analytical studies by PITT, GITT and EIS, the diffusion coefficient of Li-ions within SiOC prepared at 1100°C is in a similar order of magnitude as reported for disordered carbons, but faster than for graphite. In the case of SiOC/X (X=Si, Sn) nano-composites, an additional Li-alloy forming phase is embedded within the SiOC matrix. For the synthesis of SiOC/Sn, a new innovative single-source precursor approach is introduced, which enables the in-situ precipitation of metallic Sn phase upon the thermal conversion of tin-modified polysiloxanes. Due to this microstructural design, the Li-ion storage capacity of the composite is enhanced, compared to pure SiOC. In addition, the embedding of Si and Sn alloy forming phases within stabilizing SiOC matrices strongly increases their cycling stability upon continuous lithiation and delithiation

Model-based estimation of in-car-communication feedback applied to speech zone detection

Modern cars provide versatile tools to enhance speech communication. While an in-car communication (ICC) system aims at enhancing communication between the passengers by playing back desired speech via loudspeakers in the car, these loudspeaker signals may disturb a speech enhancement system required for hands-free telephony and automatic speech recognition. In this paper, we focus on speech zone detection, i.e. detecting which passenger in the car is speaking, which is a crucial component of the speech enhancement system. We propose a model-based feedback estimation method to improve robustness of speech zone detection against ICC feedback. Specifically, since the zone detection system typically does not have access to the ICC loudspeaker signals, the proposed method estimates the feedback signal from the observed microphone signals based on a free-field propagation model between the loudspeakers and the microphones as well as the ICC gain. We propose an efficient recursive implementation in the short-time Fourier transform domain using convolutive transfer functions. A realistic simulation study indicates that the proposed method allows to increase the ICC gain by about 6dB while still achieving robust speech zone detection results.Comment: 5 pages, submitted to International Workshop on Acoustic Signal Enhancement (IWAENC), Bamberg, Germany, 202